Monthly Weather Bulletin October 2009

(1)

Spells of dry and relatively calm weather during

October alternated with more unsettled

conditions, when frontal systems associated with

deep Atlantic depressions brought spells of

heavy rain. Monthly rainfall totals were below

normal over much of the west and north but

were above normal elsewhere. The heaviest daily

falls in most areas were on the 6th, 9th, in the

period 19th to 24th and on the 30th/31st. There

were between 13 and 18 wetdays during the

month in most places (days with 1mm or more

rainfall), less than the normal range for October

Monthlyy Weather

Bulletin

N

No

o.. 2

28

82

2 OCTOBER 2009

W

A

AR

RM

M B

BU

UT

T M

MO

OS

ST

TL

LY

Y C

CL

LO

OU

UD

DY

Y

;;

BECOMING WET AFTER MAINLY DRY FIRST HALF

Above-Cumulonimbus clouds over Dublin during the afternoon of the 21st brought heavy showers, with thunderstorms in some places.

INSIDE

Pacific

typhoons over

Philippines

& Japan

--page 2page 2

Wind & Elements ... 4

Marine & Pr

essur

e ...

5

5 Agmet /La

Agmet /La

b ...

6

6 Diary ... 8

Diary ... 8

R

ainf

all ...

10

10 T

T

emper

a

tur

e ...

12

12 Sunshine ...

Sunshine ...

14

14 W

W

or

ld w

ea

ther ...

15

15 F

F

ea

tur

e ...

16

Strong El Niño develops

Produced by Met Éireann, Glasnevin Hill, Dublin 9. Annual subscription 80 euro

For more information-tel: +353-1-8064260 fax: +353-1-8064216 climate.enquiries@met.ie

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(2)

of between 17 and 22 wetdays. Mean

monthly air temperatures were above

normal everywhere, by more than one

degree generally. As shown by the

charts on page two, there was very little

variation in maximum temperatures

throughout the month, but minimum

values of air temperature fluctuated

from close to freezing on a number of

nights to almost 15°C in places towards

the end of the month. There were

between four and seven ground frosts

recorded in most inland areas during

the month, close to the normal amount

for October, but Mullingar was the only

station to record an air frost, which was

slight. There were some sunny days

during the first week of the month and

also around mid-month, but much of

October was dull. Sunshine totals were

below normal except in western areas

and it was the dullest October for

between 12 and 14 years in many places.

1st to 11th:

Although areas of high

pressure influenced the weather over

Ireland during this period, some rainfall

was recorded each day, but amounts were

generally small. Heavy falls were recorded

in many areas on both the 6th and 9th,

however, as depressions passed close to the

northwest coast; these were also the only

windy days in a relatively calm spell. After a

dull start, many days during the period were

sunny. Daytime temperatures were above

normal throughout, but some ground frost

was recorded between the 6th and 8th

under clear skies.

12th to 17th:

High pressure became

centred close to Ireland, giving dry weather

everywhere except for some light coastal

showers, while winds were light

throughout. Sunshine amounts were

variable, with most sunshine recorded in

southern areas at first, and over the north

of the country later in the period. Daytime

2 WEATHER

October 2009

Early October brought further destructive typhoons in the Pacific, as tropical storm Parma crossed over the northern tip

of Luzon Island, part of the Philippines, as a Category 1 typhoon on the 3rd. The storm battered the island with damaging

winds and heavy rain before moving over the South China Sea, where it stalled, spinning more or less in place for about a

day and a half. On the 6th, the storm reversed direction and moved back southeastwards over Luzon, as another powerful

storm- Super Typhoon Melor, moved close enough to influence its motion. When two cyclones approach one another,

they can interact in a variety of ways. One interaction is the Fujiwara Effect, in which the two storms are drawn together

and begin to circle each other. In this case, Parma was drawn towards the stronger Melor. Occasionally, the stronger

storm will absorb the weaker storm, but in this case Parma continued to move southwards, eventually moving over the

South China Sea on the 8th. The image shown below blends two satellite overpasses to show the proximity of the two

storms to one another. The left half of the image, showing Tropical Storm Parma, is from the Moderate Resolution Imaging

Spectroradiometer (MODIS) on NASA's

Terra satellite, acquired at 1035UTC on

the 6th.The right half of the image was

taken just under two hours later by the

MODIS instrument on NASA's Aqua

satellite.The time difference causes the

subtle differences in lighting from one

side of the image to the other. While

Parma maintains a spiral shape, it no

longer has the tightly packed bands of

clouds exhibited by the much stronger

Melor, which at its peak had sustained

winds of about 200km/h, making it a

Category 4 typhoon.

Parma left at least 22 people dead and

caused millions of euros worth of damage

to crops and infrastructure in floods and

landslides across northern Luzon. Melor

came ashore over central Japan early on

the 8th, bringing heavy rain with gusts of

up to 150km/h, flooding roads and ripping

roofs off houses.

(image courtesy NASA Earth Observatory)

Blended visible satellite images on 6th

LUZON

CHINA

East China East China

Sea Sea

T

Typhoonyphoon

Melor

T

Typhoonyphoon Parma

(3)

temperatures remained above normal, while

some ground frost was again recorded at

inland stations where skies were clear.

18th to 31st:

A period of unsettled

weather, as a series of Atlantic depressions

and their associated fronts moved over

Ireland. Heaviest rain was measured on the

19th/20th and 30th/31st, with widespread

heavy showers also on the 21st and 22nd.

Winds were between southeasterly and

southwesterly in direction, bringing air of

tropical origin over the country; both

daytime and nightime temperatures were

around five degrees above normal towards

the end of the month. This airstream was

also very humid, giving cloudy conditions

on most days. Gale to storm force gusts

were recorded in all areas on the 24th.

Wind and elements:

Mean windspeeds for

the month of between 6 and 12 knots (11

and 22km/h) were below normal

everywhere. Malin Head’s monthly mean of

12 knots (22km/h) was its lowest for

October since 1958. The same station

measured the highest gust of the month,

however, 58 knots (107km/h) on the 24th.

Thunder was infrequent during the month

and was isolated when it did occur, except

on the 31st when it was widespread. There

were no reports of hail. Most occurrences

of fog coincided with days when ground

frost was recorded: in the period 6th to 8th

and on the 12th, 16th and 17th.

3 WEATHER

October 2009

Below

A spell of heavy rain at the end of the month gave 2-day falls of over 50mm in places, resulting in localised flooding- pictured below is a scene from Inistioge, Co. Kilkenny, on the 31st. (picture Gerry Dunne)

(4)

4 WIND & ELEMENTS

CO. CARLOW

Carlow (Oak Park) 6.5 240° 24 24/14 240° 40 24/1426 0 1 4

CO. CAVAN

Ballyhaise 6.1 240° 23 24/17 250° 43 24/1648 0 1 12

CO. CLARE

Shannon Airport 8.7 240° 33 24/14 230° 46 24/1313 0 4 13 0 0 0 0 3

150° 23 6/13 290° 31 4/0840

CO. CORK

Roche’s Point 11.1 230° 36 24/11 230° 48 24/1129 1 7 64

Cork Airport 8.5 240° 30 24/12 230° 46 24/1108 0 4 22 0 0 0 0 11

CO. DONEGAL

Malin Head 12.1 250° 40 2/24 250° 58 24/2034 3 10 84 0 0 0 0 0

260° 40 3/ 5

CO. DUBLIN

Dublin Airport 10.2 250° 38 24/17 250° 54 24/1603 1 6 35 0 0 0 0 1

Casement Aerodrome 8.4 240° 32 24/18 250° 45 24/1715 0 4 26 0 0 0 1 0

CO. KERRY

Valentia Observatory 7.7 250° 34 24/12 250° 47 24/1103 1 7 25 0 0 0 0 0

CO. MAYO

Belmullet 10.3 270° 32 24/13 270° 53 24/1635 0 12 68 0 0 0 1 0

Knock Airport 8.8 250° 34 24/14 250° 55 24/1353 1 5 26 0 0 0 0 18

CO. TIPPERARY

Gurteen 7.7 250° 25 24/15 250° 38 24/1503 0 1 8

CO. WESTMEATH

Mullingar 5.6 240° 18 24/15 230° 33 24/1437 0 0 0

150° 18 27/12

CO. WEXFORD

Johnstown Castle 6.4 200° 22 24/10 200° 35 24/1010 0 2 8

W

IND

((

KNOTS

))

E

LE

EME

ENTS

County /

Station

Valentia Observatory

Dublin Airport

October 2009

Mean Max. 10-min. mean Max. Gust Days with Hours with

speed dir. speed date/hour dir. speed date/time gales gale gusts gale gusts Snow Snow Lying Hail Thunder Fog

P

ERCENTAGE FREQUENCY OF WIND DIRECTION

N

NE

NW

SW

W

SE

_SE

NE

N

E

S

E

S

Calm: 1.1%

_{Calm: 0.3%}

2% 4%

6% 8%

2% 4%

6% 8%

1-10 knots >10 knots

(5)

5 MARINE & PRESSURE

HHoouurrllyy w

wiinndd aanndd w

waavvee ccoonnddiittiioonnss aatt M

M33 ((5511..2222°°NN,, 1100..5555°°W

W))

dd

ee

gg

rree

ee

ss

ffrr

oo

mm

nn

oo

rrtt

hh

kknn

oo

ttss

°°CC

360 300

200

100

0

17 16 15

14 13 12 40

30

20

10

0

M

E

EA

AN

N

A

T

TM

MO

OS

SP

PH

HE

ER

RIIC

C

P

R

RE

ES

SS

SU

UR

RE

E

Mean sea level pressure values for the month varied

between 1011hPa in the northwest and over 1014hPa

in the southeast, close to normal values for October

everywhere. There was a wide variation in pressure

values during the month, with highest values around

mid-month. After Malin Head recorded October’s

highest pressure value, 1038.6hPa on the 16th, there

was a steep decline in pressure until the 21st, when the

month’s lowest value of 978.5hPa was measured at

Valentia Observatory, as a deep depression moved

close to the southwest of Ireland.

mm

ee

ttrr

ee

ss

12

10 8

6

4 2

0

40˚N 50˚N 60˚N 70˚N 80˚N

H 1024

L 1003

L 1005

L 1012

1008

1016

16

1016

10 16 October 2009

M

ARINE

O

BSERVATIONS FROM

I

RISH

M

ARINE

D

ATA

B

UOY

N

ETWORK

Monthly mean MSL pressure, based on 1200 UTC values

SSuum

mm

maarryy ooff M

Meeaann M

Moonntthhllyy VVaalluueess

Sea Mean Max. Mean Max. Buoy surface wind 10-min wave wave

temp. speed wind height height

(°C) (knots) (knots) (m.) (m.)

M2 not available

M3 14.7 13.4 29 2.6 6.8

M4 13.3 14.7 33 2.7 7.2

M5 14.5 n/a n/a 1.8 5.3

M6 14.5 15.1 32 2.8 6.9

Malin 13.0

Head

Wind Direction

Wind Speed

Sea Temperature

Wave Height

1 5 10 15 DATE 20 25 31

M6

_M5

z

Malin Head

M4

M2

M3

M

Meeaann ddaaiillyy M

Meeaann SSeeaa LLeevveell pprreessssuurree

(hPa) 980

990 1000 1010 1020 1030 1040

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

—

•

—

Valentia Observatory —

•

—

(6)

AGMET / LABORATORY

CO. CARLOW

CARLOW (OAK PARK) 11.2 11.7 11.9

CO. CAVAN

BALLYHAISE 11.2 11.8 12.2

CO. CLARE

SHANNON AIRPORT 12.5 12.9 13.4 CARRON 12.4 13.2

CO. CORK

ROCHE’S POINT 12.2 12.3 13.1 FERMOY (MOOREPARK) 12.8 13.0 13.4 CORK AIRPORT 11.3 11.9 13.1 SHERKIN ISLAND 13.2 13.5 13.6 BALLINCURRIG (PEAFIELD) 11.1 11.0 12.2

CO. DONEGAL

MALIN HEAD 11.1 12.0 12.9

CO. DUBLIN

DUBLIN (PHOENIX PARK) 10.9 12.0 12.7 DUBLIN AIRPORT 10.6 11.1 12.0 CASEMENT AERODROME 11.0 11.6 12.3

CO. KERRY

VALENTIA OBSERVATORY 12.9 13.5 14.4

CO. LIMERICK

MOUNT RUSSELL 11.2 11.9

CO. MAYO

BELMULLET 12.0 12.9 13.8 STRAIDE 11.9 KNOCK AIRPORT 10.2 11.0 11.7

CO. MEATH

WARRENSTOWN 11.2 12.0 12.6

CO. TIPPERARY

FETHARD (PARSONSHILL) 11.5 12.0 GURTEEN 10.9 11.3 12.1

CO. WATERFORD

DUNGARVAN (CARRIGLEA) 12.5 12.8

CO. WESTMEATH

MULLINGAR 11.4 12.2 13.0

CO. WEXFORD

JOHNSTOWN CASTLE 12.0 12.2 12.6 JOHN F. KENNEDY PARK 11.8 12.6 14.0 CLONROCHE (KNOXTOWN) 11.7 12.3 12.6

100mm 200mm 300mm

County/ Station

Soil Temperatures at 0900UTC

°C

Mean 100mm

Soil Temperatures (°C)

at 0900UTC

(difference from 1961-90 normals in brackets)

Soil Moisture Deficits (mm)

10th of month / end of month

(0 represents field capacity, -10 saturation)

11.1 (+1.6)

10.2

11.2

12.5 (+2.1)

12.9 (+2.2)

11.2 (+1.7)

12.0 (+1.5)

10.9

11.3 (+1.3)

11.4 (+2.3)

11.0 (+1.7)

0/-4

5/-3

9/-3

14/0

5/-1

_1/0

1/-4

1/-5

4/0

1/0

_8/0

12.0 (+1.6)

NO2-N

SO2-S

SO4-S

z z z

(μgs/m3₎

electrical conductivity

(

μ

S/cm)

Chemical Analysis of Precipitation and Air Samples

at Valentia Observatory

0 0.5 1 1.5 2 2.5 3 3.5

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

0 50 100 150 200 250 3 4 5 6 7 8 PRECIPITATION AIR

Acid rain occurs when pollutants combine with moisture in the air to form sulphuric or nitric acid. pH is the simplest way of measuring the acidity of precipitation. Usually pH of 7.00 is considered neutral but this is not the case in rainfall samples. Pure water in the atmosphere has an equilibrium pH value of 5.65 at 20°C owing to carbon dioxide in the air dissolving to form carbonic acid. Any value below pH 5.65 is considered acid while any value above is considered alkaline.

Sulphur dioxide and sulphate in air contribute to the formation of sulphuric acid; nitrate in air contributes to the formation of nitric acid.

Conductivity measures the total ion activity in the rainfall, i.e. the higher the conductivity the greater the number of ions present.

pH

data shown here are interim values and are subject to change

pH and electrical conductivity are not available on dry days (<0.2mm)

6

October 2009

(7)

7 AGMET

October 2009

Co. Cavan 1-10 16.8 - 6 3 14.1 6.5 10.3 - -1.9 7 1 61 16 -5.9 7 1 - - 27.6 - Cavan (Loreto) 11-20 21.2 - 5 4 14.1 7.2 10.7 - 1.8 12 0 64 17 -0.6 12 2 - - 27.0 -

21-end 74.5 - 11 9 15.1 10.3 12.7 - 7.9 21 0 92 31 5.2 21 0 - - 19.1 -

month 112.5 22 16 14.5 8.1 11.3 1.9 7 1 216 63 5.9 7 3 73.7

-Co. Cork 1-10 36.0 - 4 4 15.6 7.9 11.8 - 4.2 7 0 74 24 4.9 8 0 12.9 13.7 29.4 - Fermoy 11-20 26.5 - 5 3 15.0 8.3 11.7 - 1.8 17 0 73 24 -0.6 12 2 12.9 13.4 24.9 - 21-end 90.4 - 9 9 15.8 10.2 13.0 - 5.4 26 0 95 36 5.4 26 0 12.7 13.1 24.4 -

month 152.9 153 18 16 15.5 8.8 12.2 1.8 1.8 17 0 242 84 -0.6 12 2 12.8 13.4 78.7 98

Co. Donegal 1-10 28.1 - 9 7 13.8 6.6 10.2 - 2.5 7 0 59 13 0.1 7 0 - - - - Glenties 11-20 11.6 - 5 4 14.8 7.7 11.3 - 1.1 12 0 70 22 -1.5 17 2 - - - - 21-end 106.8 - 11 10 15.4 10.7 13.1 - 7.4 24 0 95 35 2.1 24 0 - - - -

month 146.5 81 25 21 14.7 8.4 11.6 1.6 1.1 12 0 224 70 -1.5 17 2 - - - -

Co. Kerry 1-10 29.3 - 8 5 15.3 8.2 11.8 - 3.0 7 0 74 23 -0.5 7 1 - - 27.7 - Ardfert 11-20 15.7 - 6 2 15.5 8.7 12.1 - 6.1 17 0 77 25 3.6 17 0 - - 27.7 - 21-end 87.2 - 11 9 16.3 10.6 13.5 - 6.5 21 0 100 40 3.5 21 0 - - 32.0 -

month 132.2 - 25 16 15.7 9.2 12.5 1.5 3.0 7 0 251 89 -0.5 7 1 - - 87.4 -

Co. Monaghan 1-10 13.0 - 5 3 14.1 6.3 10.2 - -0.6 7 1 59 15 - - - - - - Carrickmacross 11-20 27.9 - 5 3 14.5 7.2 10.9 - 1.1 17 0 66 19 - - - - - -

21-end 52.7 - 11 8 15.2 9.8 12.5 - 6.8 29 0 89 30 - - - - - -

month 93.6 102 21 14 14.6 7.8 11.2 - -0.6 7 1 214 63 - - - - - -

Co. Waterford 1-10 46.0 - 4 3 16.2 7.2 11.7 - 2.9 8 0 74 26 2.1 8 0 - 12.8 41.4 - Dungarvan 11-20 32.8 - 5 3 15.6 8.7 12.2 - 4.0 17 0 78 27 2.8 12 0 - 12.7 32.5 -

21-end 98.6 - 11 9 15.9 10.6 13.3 - 4.8 26 0 97 39 4.0 26 0 - 12.9 24.3 -

month 177.4 - 20 15 15.9 8.9 12.4 1.5 2.9 8 0 249 91 2.1 8 0 - 12.8 98.2 112

Co. Wexford 1-10 37.8 - 4 3 14.8 7.3 11.1 - 5.5 2 0 67 19 1.8 8 0 11.9 14.8 28.4 - J.F.K. Park 11-20 30.1 - 4 4 14.7 8.6 11.7 - 4.5 12 0 72 21 0.2 12 0 11.4 13.8 33.6 - 21-end 108.1 - 9 9 15.0 10.5 12.8 - 6.8 26 0 92 32 1.2 26 0 12.1 13.5 20.6 -

month 176.0 160 17 16 14.9 8.8 11.9 1.1 4.5 12 0 231 72 0.2 12 0 11.8 14.0 82.6 99

amount % of average rain days wet days mean max. mean min. mean daily diff. from average lowest min. date days with air frost degree days > 4.4°C degree days > 10.0°C lowest "grass-min." date days with ground frost mean 10cm at 0900h mean 30cm at 0900h total no. of hours % of average

S

Stta

attiio

on

n

period

R

AINFALL

T

EMPERATURE(°C)

S

UNSHINE

(MM) (HOURS)

10-

DAY VALUES FOR SELECTED

A

GROMETEOROLOGICAL

S

TATIONS

M

EEAASSUURREEDD

P

OOTTEENNTTIIAALL

E

VVAAPPOOTTRRAANNSSPPIIRRAATTIIOONN

((P

P..E

E..))

A

ANNDD

S

OOIILL

M

OOIISSTTUURREE

P.E.(mm) Soil Moisture(mm) Station Period Amount Deficit Accum’ltd Deficit Surplus

M

OONNTTHHLLYY

E

VVAAPPOORRAATTIIOONN

((

MMMM

))

FFRROOMM

C

LLAASSSS

A

A P

P

AANN County Station Monthly Monthly

Rainfall (mm) Evaporation (mm)

Cork Fermoy (Moorepark) 152.9 31.9

Kerry Valentia Observatory 230.9 59.0

Kerry North Kerry Landfill 155.2 17.3

Mayo Newport (Furnace) 132.3 11.0

Offaly Derrygreenagh 107.2 11.7

Waterford Dungarvan (Carriglea) 177.4 18.1

Wexford J.F.K. Park 176.0 49.9

P

P..E

E..

(Penman)

G

LLOOBBAALL

S

OOLLAARR

R

AADDIIAATTIIOONN

(MJ/sq.m.)

Station total(mm) 1st-10th 11th-20th 21st-end Total

19.9 - 0 34 17.2 - 0 21 12.7 - 0 94

49.8

16.3 - 0 36 30.1 - 0 11 n/a n/a n/a n/a

n/a

Co.Carlow

Carlow (Oak Park)*

Co.Cavan

Ballyhaise*

Co.Clare

Shannon Airport

Co.Cork

Cork Airport Roche’s Point*

Co.Donegal

Malin Head

Co.Dublin

Dublin Airport Casement Aerodrome

Co.Kerry

Valentia Obs.

Co.Mayo

Belmullet Knock Airport

Co.Tipperary

Gurteen

Co.Westmeath

Mullingar*

Co.Wexford

Johnstown Castle*

63.30 54.79 37.01 155.10

60.49 42.84 24.75 138.08

global solar radiation values for stations marked * are provisional

80.25 52.08 47.97 180.30

64.42 48.08 31.56 144.06

67.42 55.31 43.04 165.77

75.18 56.91 44.31 176.40

68.27 56.07 45.53 169.87

66.03 56.79 37.03 159.85

69.14 49.47 35.31 153.92

65.77 55.42 43.89 165.08

Co. Kerry

1-10 Valentia Obs. 11-20

21-end

month Co. Wexford

1-10 Johnstown Castle 11-20 21-end

month

24

22

28

24

29

26 26

29

25 21

23

22

(8)

Thursday 1st:Apart from some rain or drizzle in southern coastal areas early on, it was a mainly dry day with some sunny spells. Cool, with afternoon temperatures a few degrees below normal. Some light rain on northwestern coasts in the evening. Winds were light northwesterly.

Rainfall: nil to trace generally, >1mm at Valentia and Cork Airport Temperature: max. 11°C to 14°C, min. 7°C to 12°C, no ground frost Sunshine: nil to 3 hours, sunniest at Malin Head, nil at Knock Airport

Friday 2nd:Outbreaks of rain or drizzle in Ulster and north Connacht

overnight, dry elsewhere. The day was generally dull and damp with rain and drizzle spreading to many parts during the morning; it was patchy in the southern half of the country, with parts of the south and southeast remaining dry. Some sunny spells, mainly these in the south. Winds were westerly backing southwesterly, moderate to strong and gusty, strongest on northwest coasts.

Rainfall: nil to 2mm generally, 9mm at Malin Head

Temperature: max. 13°C to 17°C, min. 7°C to 12°C, no ground frost Sunshine: nil to 5 hours, sunniest at Cork Airport

Saturday 3rd:Wet and windy overnight in the northern half of the country. The wet and windy weather moved southwards to all areas during the morning and showery weather with scattered showers and sunny spells followed on from the north during the day. Sunniest in the north. Winds were southwesterly, fresh to strong and gusty, veering westerly and easing slightly.

Rainfall: nil to 5mm, heaviest at Malin Head, nil at Roche’s Point Temperature: max. 12°C to 17°C, min. 6°C to 11°C, no ground frost Sunshine: trace to 5 hours, sunniest at Malin Head, trace at Valentia

Sunday 4th:Scattered light showers in the west and north overnight became more widespread during the late morning and early afternoon, affecting Connacht and Ulster. Sunny spells in the northern half of the country. Dry throughout by evening. Winds were light westerly, backing southeasterly.

Rainfall: nil to >1mm, heaviest at Malin Head and Belmullet Temperature: max. 12°C to 14°C, min. 5°C to 9°C, no ground frost Sunshine: 1 to 7 hours, sunniest at Malin Head, 1 hour at Valentia

Monday 5th:Some patchy rain in the west and northwest during the

morning, dry elsewhere with some sunshine. The afternoon was dry with some sunny spells, mainly in the north and east. Rain in the north and northwest by late evening, dry elsewhere. Winds were light, south or southwesterly.

Rainfall: nil to 2mm, heaviest at Johnstown Castle

Temperature: max. 14°C to 16°C, min. 5°C to 10°C, no ground frost Sunshine: 1 to 7 hours, sunniest at Dublin Airport, 1 hour at Valentia

Tuesday 6th:Heavy showers overnight. Rain and drizzle died out over the north and northwest during the morning. At the same time a band of rain stretching from south Connacht to north Leinster moved gradually southeastwards, giving some very heavy falls. A clearance followed from the northwest, with some sunny spells developing there. Dry everywhere late in the night with some ground frost developing. Winds were light northwesterly.

Rainfall: trace to 44mm, heaviest at Johnstown Castle, trace at Knock Airport Temperature: max. 11°C to 16°C, min. 2°C to 9°C, ground temperatures

down to -3°C at Casement Aerodrome

Sunshine: nil to 7 hours, sunniest at Belmullet

Wednesday 7th:Dry overnight with some ground frost in places. The

morning was mainly dry with sunny spells, apart from some well-scattered showers in the north and northwest. Continuing dry during the afternoon with some sunshine. A few scattered showers along northern and northwestern coasts during the evening, otherwise dry with clear spells. Light westerly winds.

Rainfall: nil to trace generally, <1mm, at Malin Head

Temperature: max. 12°C to 15°C, min. -1°C to 9°C, ground temperatures

down to -5°C at Mullingar

Sunshine: 1 to 7 hours, sunniest at Valentia, 1 hour at Belmullet

Thursday 8th:Scattered showers in the north and northwest overnight, dry elsewhere with clear spells. The day was generally dry with spells of sunshine throughout. Becoming cloudy in western areas late in the period, otherwise clear. Winds were light westerly, backing southerly.

Rainfall: nil to trace

Temperature: max. 12°C to 16°C, min. 3°C to 9°C ground temperatures

down to -1°C at Dublin Airport

Sunshine: 5 to 8 hours, sunniest at Dublin Airport, 5 hours at Cork Airport

Friday 9th: Cloudy overnight with rain near the west coast by morning. The rain spread quickly eastwards to all areas and was heavy and persistent at times. Clearer weather with well-scattered showers followed on from the west in the afternoon. Most sunshine was recorded in the extreme southwest. Winds were light to moderate southeasterly, increasing moderate to fresh and gusty, veering southwesterly and decreasing.

Rainfall: 3 to 15mm, heaviest at Valentia, 3mm at Belmullet Temperature: max. 12°C to 18°C, min. 6°C to 12°C, no ground frost Sunshine: nil to 5 hours, sunniest at Valentia

Saturday 10th:Mist or fog cleared during the morning and apart from

isolated light showers it was a dry day with some sunny spells, mainly in the south and southwest. Afternoon temperatures were around normal for the time of year. Becoming cloudier during the evening, with rain moving onto western coasts. Winds were light to moderate, southwesterly.

Rainfall: nil to trace generally, 1mm at Belmullet

Temperature: max. 14°C to 17°C, min. 7°C to 12°C, no ground frost Sunshine: nil to 8 hours, sunniest at Cork Airport

Sunday 11th:Rain moved into the west early in the night and crossed the midlands and south by morning. There were heavy bursts in the west midlands during the early part of the night. The rain cleared southern areas before noon and the rest of the day remained dry. After a cool start, it was warm during the afternoon with some sunny spells. Winds were light southwesterly, veering northwesterly for a time, then light variable by evening.

Rainfall: nil to 6mm, heaviest at Shannon Airport, nil at Roche’s Point Temperature: max. 12°C to 18°C, min. 4°C to 10°C, ground temperatures

down to -1°C at Casement Aerodrome

Sunshine: 1 to 6 hours, sunniest at Shannon Airport, 1 hour at Belmullet

Monday 12th:A cool night with fog and ground frost inland. The fog cleared during the morning and the rest of the day was dry, apart from some drizzle near western coasts. Prolonged sunshine in the east, progressively cloudier further west. Winds were light, southerly or variable in direction.

Rainfall: nil to trace

Temperature: max. 13°C to 16°C, min. 1°C to 8°C, ground temperatures

down to -2°C at Mullingar

Sunshine: <1 to 9 hours, sunniest in the east, <1 hour at Valentia

Tuesday 13th:Cloudy overnight with some patchy rain and drizzle, mainly over the north and east of the country. Rain and drizzle cleared the east early in the morning, while some fog lingered in parts of the midlands and west through the morning. The afternoon and evening were mostly cloudy, with some drizzle in places. Winds were light, westerly in direction.

Rainfall: nil to 1mm, heaviest at Knock Airport

Temperature: max.14°C to 17°C, min. 5°C to 13°C, no ground frost

Sunshine: trace to 1 hour, sunniest at Dublin Airport, trace in the west and north

Wednesday 14th: There were contrasting conditions over the country during the day. While the west and south had a relatively dry day with long sunny spells, the north and east remained overcast with occasional spells of light rain or drizzle. Winds were light and variable in direction throughout. Rainfall: nil to 1mm, heaviest at Ballyhaise, nil in the west and south Temperature: max. 14°C to 18°C, min. 8°C to 13°C, no ground frost

Sunshine: nil to 10 hours, sunniest at Shannon Airport, nil in the north and east

Thursday 15th:Outbreaks of rain overnight, mainly in the north and

midlands. By morning, any remaining rain was confined to the extreme northeast. The rest of the day was dry with some sunny spells, mostly in the west, while the east remained overcast. Winds were light and variable.

Rainfall: nil to trace generally, 2mm at Malin Head, 1mm at Ballyhaise Temperature: max. 13°C to 16°C, min. 7°C to 12°C, no ground frost Sunshine: nil to 3 hours, sunniest at Belmullet, nil at Dublin Airport

Thursday 16th:A dry day generally with varying amounts of sunshine. Long spells of sunshine in the north, mainly overcast in the south. Cold after dark in the east and midlands with ground frost recorded. Winds were light, variable.

Rainfall: nil

Temperature: max. 13°C to 17°C, min. 3°C to 12°C ground temperatures

down to -2°C at Dublin Airport

Sunshine: nil to 8 hours, sunniest at Malin Head, nil at Valentia

(9)

Friday 16th:Cold overnight with blustery showers, some of hail, mainly in western parts. It was a cool, breezy day with scattered showers and sunny spells. The showers gradually died out during the evening. Winds were light to moderate west or northwesterly, backing southwesterly and easing during the afternoon.

Rainfall: nil to 5mm, heaviest at Malin Head

Temperature: max. 11°C to 14° min. 4°C to 8°C, ground temperatures

below zero at Birr

Sunshine: 4 to 7 hours, sunniest at Dublin Airport, 4 hours at Belmullet

Saturday 17th:Cold overnight with fog and frost in a few inland areas. The day continued mostly dry, the only exception being some drizzle near the south coast late in the evening. Prolonged sunshine in many areas, but it was cloudier in the west and southwest. Winds were light variable, becoming southerly.

Rainfall: nil to trace generally, <1mm at Cork Airport

Temperature: max. 12°C to 16° min. 0°C to 8°C, ground temperatures

down to -2°C Casement Aerodrome

Sunshine: 2 to 9 hours, sunniest at Casement Aerodrome, 2 hours at Valentia

Sunday 18th: Ulster and Connacht had a dull, wet day with rain and drizzle, heavy and persistent at times. Drier elsewhere with scattered outbreaks of rain or drizzle and some short sunny spells in the east. The rain became more widespread during the evening, before clearing eastwards later on. Winds were light to moderate south or southwesterly, becoming light and variable later.

Rainfall: <1 to 9mm, heaviest at Claremorris, <1mm at Carlow (Oak Park) Temperature: max. 11°C to 15°C, min. 6°C to 13°C, no ground frost Sunshine: nil to <1hour, sunniest at Dublin Airport

Monday 19th: Overnight rain and drizzle, particularly in the northern half of the country, continued during the morning, with clear spells in the east and southeast. Wet and windy weather moved in from the Atlantic early in the afternoon, moving slowly northeastwards over the country. Rain was particularly heavy in the southwest. Winds were light to moderate southeasterly, increasing moderate to fresh and gusty during the day. Rainfall: trace to 34mm, heaviest at Valentia, trace at Gurteen Temperature: max. 12°C to 14°C, min 9°C to 12°C, no ground frost Sunshine: nil to 2 hours, sunniest at Dublin Airport

Tuesday 20th:Rain in the south and west moved eastwards overnight and during the morning, clearing the northeast by mid-afternoon. The rain was particularly heavy in the southeast and midlands. Scattered showers later over Munster and south Leinster. Sunshine in the south and southwest. Winds were variable moderate, stronger in the north, becoming light by evening.

Rainfall: 1 to 26mm, heaviest at Johnstown Castle, 1mm at Dublin Airport Temperature: max. 12°C to 15°C, min. 6°C to 10°C, no ground frost Sunshine: nil to 8 hours, sunniest at Shannon Airport, nil at Malin Head

Wednesday 21st:Showers overnight, heavy in the east and south, some clear spells also. The showers became widespread during the day, some heavy. Some sunny spells also between the showers, mainly in the northwest. Winds were strong and gusty southeasterly, easing by evening.

Rainfall: nil to 29mm, heaviest at Carlow (Oak Park), nil at Malin Head Temperature: max. 13°C to 15°C, min. 6°C to 10°C, no ground frost Sunshine: trace to 4 hours, sunniest at Belmullet, trace at Valentia

Thursday 22nd:Showers overnight, some heavy in the midlands. During the morning the showers became more frequent and heavy with some sunny spells also. The showers continued during the afternoon, eventually dying out by evening. Winds were light southeasterly.

Rainfall: nil to 25mm, heaviest at Ballyhaise, nil at Belmullet and Malin Head Temperature: max. 14°C to 16°C, min. 7°C to 11°C, no ground frost Sunshine: 2 to 7 hours, sunniest at Cork Airport, 2 hours at Dublin Airport

Friday 23rd: Some showers in the north and northwest overnight, otherwise mainly dry. Sunny in the northwest, generally overcast elsewhere with light rain gradually spreading eastwards. Very heavy showers in the extreme north during the afternoon. Heavy rain moved into the southwest by late evening. Winds were light, southeasterly generally.

Rainfall: nil to 4mm generally, 11mm at Malin Head

Temperature: max. 12°C to 17°C, min. 6°C to 11°C, no ground frost Sunshine: nil to 6 hours, sunniest at Belmullet, nil at Shannon Airport

Saturday 24th:A band of heavy rain in the southwest moved quickly across the country during the night, while weakening. Another band of occasionally heavy rain moved into the southwest and moved quickly northeastwards during the late morning, bringing rain to all parts by the afternoon. Drier weather followed, with some sunny spells in the south and east, but heavy rain continued in the north after dark. Winds were southeasterly, veering southwesterly, gale or strong gale force as the front progressed.

Rainfall: 1 to 32mm, heaviest at Malin Head, 1mm at Dublin Airport Temperature: max. 14°C to 17°C, min. 10°C to 12°C, no ground frost Sunshine: nil to 5 hours, sunniest at Cork Airport, nil at Belmullet

Sunday 25th:It was a breezy day generally with sunny spells and scattered showers, some heavy. Dry in most parts by evening. Westerly winds were near gale force and very gusty on north and northwest coasts overnight, fresh to strong and gusty elsewhere. Winds eased slowly throughout the day and were light to moderate by late evening.

Rainfall: nil to 7mm, heaviest at Malin Head, nil at Johnstown Castle Temperature: max. 12°C to 16°C, min. 8°C to 12°C, no ground frost Sunshine: trace to 7 hours, sunniest at Cork Airport, trace at Malin Head

Monday 26th:The northern half of the country had a largely dry day with some hazy sunshine. Milder weather with outbreaks of rain and drizzle and fog patches moved eastwards across the southern half of the country, where it was dull and damp with little or no sunshine. Rain moved in from the Atlantic in the late afternoon and pushed northeastwards over most of the country, heavy in places. Winds were light to moderate, variable in direction.

Rainfall: trace to 12mm, heaviest at Belmullet, trace at Dublin Airport Temperature: max. 12°C to 17°C, min. 6°C to 10°C, no ground frost Sunshine: nil to 3 hours, sunniest at Casement Aerodrome, nil at Cork Airport

Tuesday 27th:Heavy rain moved into the southwest early in the night and spread northeastwards, clearing the country around noon. Dry weather followed from the southwest during the morning, but another spell of rain moved in over the southwest and west, crossing the country during the afternoon and evening, giving some heavy falls. A clearance followed from the west by mid-afternoon. Generally overcast and mild. Winds were moderate to strong, southeasterly veering southwesterly.

Rainfall: 1 to 15mm, heaviest at Valentia, 1mm at Shannon Airport Temperature: max. 14°C to 17°C, min. 11°C to 15°C, no ground frost Sunshine: nil to trace generally, <1 hour at Casement Aerodrome

Wednesday 28th:Outbreaks of mostly light rain or drizzle throughout the day, with occasional heavier spells at times, mainly in the west. Very mild for the time of year. Sunny spells in the east, cloudy elsewhere. Winds were moderate southerly, backing southeasterly in the late afternoon.

Rainfall: nil to 1mm generally, 6mm at Knock Airport

Temperature: max. 15°C to 18°C, min. 8°C to 15°C, no ground frost Sunshine: trace to 6 hours, sunniest at Dublin Airport, trace at Knock Airport

Thursday 29th:Cloudy overnight with patchy drizzle in places. Rain and drizzle over much of the country during the day, with some mist and fog in places also. Overcast throughout. Heavy rain in the southwest by late evening. Winds were southerly, moderate to strong with occasional gusts in coastal areas.

Rainfall: nil to 5mm, heaviest at Valentia, nil at Malin Head Temperature: max. 14°C to 17°C, min. 10°C to 15°C, no ground frost Sunshine: nil to trace

Friday 30th: Heavy rain overnight, particularly in the south. The rain moved eastwards during the day, affecting all areas and giving some very heavy falls. The rain cleared the east coast during the evening. A few sunny spells in the west. Winds were southeasterly, moderate to strong and gusty. Rainfall: 6 to 37mm, heaviest at Valentia, 6mm at Dublin Airport

Temperature: max. 15 °C to 17°C, min. 10°C to 14°C, no ground frost Sunshine: nil generally < 1 hour in the west

Saturday 31st:A few showers in the west during the morning, otherwise dry. Sunny spells in most parts. The showers became more widespread and heavy during the afternoon, especially in eastern areas. Heavy rain in the southwest by evening. Winds were southwesterly, light to moderate.

Rainfall: trace to 13mm, heaviest at Casement Aerodrome, trace at Ballyhaise Temperature: max. 14°C to 17°C, min. 9°C to 13°C, no ground frost

Sunshine: 1 to 7 hours, sunniest at Belmullet, 1 hour at Valentia

9 DIARY

(10)

Rainfall totals for October were

below normal in some parts of

Ulster, but it was a wet month in

many southern and southeastern

areas. Monthly totals ranged

from 84mm at Dublin (Merrion

Square) to 269mm at Delphi

Lodge, Co. Mayo, with

percentage of normal values

between 81% of normal at

Glenties Hatchery, Co. Donegal

and 188% at Carlow (Oak Park).

Johnstown Castle’s total of

179mm was its highest for

October since 1982.

There was a spell of relatively dry

weather around mid-month in all

areas, but some heavy falls were

recorded during the first week and

particularly in the second half of

the month. These caused flooding

in some parts of the country, as soil

conditions reached saturation in

most areas by the end of the

month. The 6th, 24th and

30th/31st were the wettest days

generally, but the highest daily fall

of the month, 40.1mm, was

recorded at Mountrussell, Co.

Limerick, on the 21st. Between 13

and 18 wetdays were recorded

during the month at the majority of

stations (days with 1mm or more of

rainfall), but 20 or more wetdays

were measured in some western

areas.

10 RAINFALL

CO. CARLOW

CARLOW (OAK PARK) 152.1 188 36.8 21 20 15

CO. CAVAN

BALLYHAISE 118.9 121 22.1 21 23 17 CAVAN LORETO COLLEGE 112.5 19.5 31 22 16

CO. CLARE

SHANNON AIRPORT 106.9 115 21.8 31 21 16 CARRON 148.3 89 31.1 31 26 21

CO. CORK

ROCHE’S POINT 127.3 143 25.2 6 17 14 FERMOY (MOOREPARK) 152.9 153 30.2 31 18 16 CORK AIRPORT 180.6 143 27.1 6 21 17 SHERKIN ISLAND 145.9 119 26.4 6 22 19 BALLINCURRIG (PEAFIELD) 191.5 29.8 31 19 16

CO. DONEGAL

MALIN HEAD 118.5 100 32.4 24 20 16 GLENTIES HATCHERY 146.5 81 25.2 24 25 21 BALLYSHANNON(CATHLEEN'S FALL) 114.2 97 26.5 24 22 19

CO. DUBLIN

DUBLIN (PHOENIX PARK) 90.0 129 21.4 31 19 12 DUBLIN AIRPORT 84.9 22.9 31 20 14 CASEMENT AERODROME 103.0 149 27.0 31 17 12 DUBLIN (MERRION SQUARE) 83.7 129 18.3 31 18 13

CO. GALWAY

GALWAY (UNIV.COLL.) 113.4 88 18.3 9 21 17 MAAM VALLEY 195.8 27.1 24 24 18 BALLYGAR 102.1 95 24.6 31 22 15

CO. KERRY

VALENTIA OBSERVATORY 230.9 147 35.1 19 22 18 ARDFERT (LISCAHANE) 132.2 28.2 29 25 16

CO. LIMERICK

MOUNT RUSSELL 219.6 40.1 21 26 21

CO. MAYO

BELMULLET 114.5 85 17.9 26 22 17 STRAIDE 139.5 103 27.0 31 22 15 KNOCK AIRPORT 127.8 18.9 31 25 17 DELPHI LODGE II 269.4 39.2 19 27 20

CO. MEATH

WARRENSTOWN 134.3 160 30.6 21 20 13

CO. MONAGHAN

CARRICKMACROSS (DUNOGE) 93.6 102 18.4 31 21 14

CO. OFFALY

DERRYGREENAGH 107.2 125 23.6 31 22 16

CO. SLIGO

ARDTARMON 98.4 23.8 31 22 19

CO. TIPPERARY

GURTEEN 177.4 17.6 6 FETHARD (PARSONSHILL) 155.2 34.1 31 21 13

CO. WATERFORD

WATERFORD (TYCOR) 144.3 137 33.1 31 18 16 DUNGARVAN (CARRIGLEA) 177.4 29.9 31 20 15

CO. WESTMEATH

MULLINGAR 111.7 119 22.6 31 23 18 CO. WEXFORD

JOHNSTOWN CASTLE 179.2 166 29.7 31 18 15 JOHN F. KENNEDY PARK 176.0 160 33.5 21 17 16 CLONROCHE (KNOXTOWN) 180.3 35.8 31 23 15

County/

Station

Total % of

Number of

Amount 1961-90 Most in

Raindays Wetdays

(mm) average a day / date (>0.2mm) (>1mm)

Near normal in

north and

northwest,

wet in southeast

(11)

11 RAINFALL

October 2009

00 55 1100 1155 2200 2255

11 22 33 44 55 66 77 88 99 1100 1111 1122 1133 1144 1155 1166 1177 1188 1199 2200 2211 2222 2233 2244 2255 2266 2277 2288 2299 3300 3311

Valentia Observatory

Dublin Airport

Malin Head

Daily 0-24h rainfall values(mm)

TToottaall rraaiinnffaallll

((m

mm

m))

PPeerrcceennttaaggee ooff nnoorrm

maall rraaiinnffaallll

< 75% 75 - 100% 100 - 125% 125 - 150% > 150% < 75

75 - 100 100 - 150

150 - 200 200 - 300 > 300

(12)

12 TEMPERATURE

October was a warm month everywhere, with

mean monthly temperatures between one and

two degrees above normal almost everywhere.

They ranged from 10.6°C at Knock Airport to

13.6°C at Sherkin Island, Co. Cork.

Like the previous month, there was very little

variation in daily maximum temperatures throughout

October, with values between 13°C and 16°C

generally, although they rose a little during the last

week. It was during this period that the only

maximum value of 20°C was recorded, at Ardfert

(Liscahane), Co. Kerry, on the 28th. Other stations

recorded their highest maxima in the period 9th to

11th and on the 14th. The month’s lowest values

were recorded on the 7th, 12th and 17th. Both the

lowest air and grass minimum temperatures of the

month were recorded at Cavan (Loreto College), on

the 7th, with values of -1.9°C and -5.9°C

respectively. Unusually for October, there was no air

frost recorded at the majority of stations, while the

total of between three and six ground frosts at

inland stations was also below normal.

Temperatures above

normal, especially in south

55 1100 1155 2200

11 22 33 44 55 66 77 88 99 1100 1111 1122 1133 1144 1155 1166 1177 1188 1199 2200 2211 2222 2233 2244 2255 2266 2277 2288 2299 3300 3311

00 55 1100 1155 2200

11 22 33 44 55 66 77 88 99 1100 1111 1122 1133 1144 1155 1166 1177 1188 1199 2200 2211 2222 2233 2244 2255 2266 2277 2288 2299 3300 3311

Daily 0-24h maximum temperatures

(°C)

Daily 0-24h minimum temperatures (°C)

October 2009

z

Valentia Observatory

z

Dublin Airport

z

Malin Head

M

Meeaann TTeem

mppeerraattuurree

(difference from 1961-90 normals)

(13)

13 TEMPERATURE

CO. CARLOW

CARLOW (OAK PARK) 14.9 8.3 11.6 1.4 16.9 28 1.4 17 -1.3 7 0 4

CO. CAVAN

BALLYHAISE 14.1 8.5 11.3 16.4 28 1.3 7 -2.3 7 0 3 CAVAN LORETO COLLEGE 14.5 8.1 11.3 16.4 28 -1.9 7 -5.9 7 1 3

CO. CLARE

SHANNON AIRPORT 15.4 9.6 12.5 1.4 17.6 14 2.0 7 -1.3 7 0 2 CARRON 14.2 8.7 11.5 1.7 17.1 14 1.0 7 -1.8 7 0 3

CO. CORK

ROCHE’S POINT 14.9 10.7 12.8 1.4 17.5 11 6.6 7 3.4 8 0 0 FERMOY (MOOREPARK) 15.5 8.8 12.2 1.8 17.9 9 1.8 17 -0.6 12 0 2 CORK AIRPORT 14.4 9.3 11.9 1.5 17.3 11 5.0 7 0.5 12 0 0 SHERKIN ISLAND 16.0 11.1 13.6 1.9 18.2 11 5.6 8 2.8 8 0 0 BALLINCURRIG (PEAFIELD) 14.9 8.5 11.7 17.4 22 3.5 12 3.3 17 0 0

CO. DONEGAL

MALIN HEAD 13.8 10.1 12.0 1.2 16.7 29 28 5.5 17 2.5 5 0 0 GLENTIES HATCHERY 14.7 8.4 11.6 1.6 17.4 16 1.1 12 -1.5 17 0 2 BALLYSHANNON(CATHLEEN'S FALL) 14.5 9.4 12.0 1.6 17.3 28 29 4.7 12 0

CO. DUBLIN

DUBLIN (PHOENIX PARK) 15.3 8.3 11.8 1.4 18.0 26 28 1.6 7 -2.0 7 0 3 DUBLIN AIRPORT 14.5 7.9 11.2 17.7 28 1.2 7 -1.9 17 0 6 CASEMENT AERODROME 14.6 8.5 11.6 1.3 17.4 28 0.3 7 -3.8 7 0 6 DUBLIN (MERRION SQUARE) 14.7 10.0 12.4 0.9 18.9 28 4.9 7 0

CO. GALWAY

GALWAY (UNIV.COLL.) 15.8 7.4 11.6 0.6 19.0 14 -0.5 17 -1.5 17 1 4 MAAM VALLEY 15.4 9.0 12.2 18.9 14 3.2 7 -2.1 7 12 0 4 BALLYGAR 15.4 8.0 11.7 17.5 14 0.3 7 -1.5 7 0 1

CO. KERRY

VALENTIA OBSERVATORY 15.4 10.9 13.2 1.6 17.6 9 5.9 7 -0.9 7 0 1 ARDFERT (LISCAHANE) 15.7 9.2 12.5 1.5 20.0 28 3.0 7 -0.5 7 0 1

CO. LIMERICK

MOUNT RUSSELL 14.5 9.2 11.9 16.4 9 3.6 7 -0.7 7 0 2

CO. MAYO

BELMULLET 14.9 9.7 12.3 1.4 17.5 14 4.4 8 0.8 8 0 0 STRAIDE 15.1 8.0 11.6 1.4 18.4 14 0.2 7 -2.0 7 0 5 KNOCK AIRPORT 13.1 8.1 10.6 15.8 14 3.6 7 -1.5 12 0 1 DELPHI LODGE II 15.1 9.4 12.3 18.9 14 4.2 12 1.6 12 0 0

CO. MEATH

WARRENSTOWN 15.1 8.2 11.7 1.7 18.1 28 -0.2 7 -1.4 17 1 4

CO. MONAGHAN

CARRICKMACROSS (DUNOGE) 14.6 7.8 11.2 16.7 28 -0.6 7 -1.7 17 1 1

CO. OFFALY

DERRYGREENAGH 14.8 6.5 10.7 1.0 17.7 28 -0.5 7 4.2 21 1 0

CO. SLIGO

ARDTARMON 15.1 9.5 12.3 19.3 24 4.6 8 0.0 12 0 0

CO. TIPPERARY

GURTEEN 14.7 8.2 11.5 16.9 28 0.1 17 -2.9 7 0 4 FETHARD (PARSONSHILL) 14.4 8.2 11.3 17.0 9 2.9 7 0.8 7 0 0

CO. WATERFORD

WATERFORD (TYCOR) 15.7 9.4 12.6 1.8 17.7 11 5.3 7 0 DUNGARVAN (CARRIGLEA) 15.9 8.9 12.4 1.5 18.1 10 2.9 8 2.1 8 0 0

CO. WESTMEATH

MULLINGAR 14.4 8.0 11.2 1.5 16.2 28 -0.7 7 -4.5 7 1 4

CO. WEXFORD

JOHNSTOWN CASTLE 15.0 9.5 12.3 1.5 17.4 11 5.6 17 2.4 17 0 0 JOHN F. KENNEDY PARK 14.9 8.8 11.9 1.3 17.3 11 4.5 12 0.2 12 0 0 CLONROCHE (KNOXTOWN) 14.8 7.6 11.2 16.6 28 1.9 13 -2.5 17 0 9

Mean/ deviation

Mean Mean from 1961-90 Highest Lowest Lowest Days with max. min. average max./date min./date grass min./date air frost ground frost

County/

Station

(14)

14 SUNSHINE

CO. CAVAN

CAVAN (LORETO COLLEGE) 2.38 23 7.8 12

CO. CLARE

SHANNON AIRPORT 2.87 108 27 9.7 14

CO. CORK

FERMOY (MOOREPARK) 2.54 98 24 6.7 12

CORK AIRPORT 2.59 93 24 7.9 10

SHERKIN ISLAND 3.26 103 31 8.6 22

BALLINCURRIG (PEAFIELD) 2.62 7.3 10

CO. DONEGAL

MALIN HEAD 2.30 94 22 8.3 16

BALLYSHANNON(CATHLEEN'S FALL) 2.49 104 24 7.0 31

CO. DUBLIN

DUBLIN AIRPORT 2.88 92 27 9.4 12

CASEMENT AERODROME 2.72 88 26 9.2 12

CO. GALWAY

GALWAY (UNIV.COLL.) 3.24 119 31 9.6 14

CO. KERRY

VALENTIA OBSERVATORY 2.21 87 21 9.1 14

ARDFERT (LISCAHANE) 2.82 26 9.4 14

CO. MAYO

BELMULLET 2.73 104 26 9.4 14

STRAIDE 2.55 6.9 8

KNOCK AIRPORT 2.12 7.4 8

CO. WATERFORD

DUNGARVAN (CARRIGLEA) 3.17 112 30 9.7 12

CO. WEXFORD

JOHN F. KENNEDY PARK 2.66 99 25 8.0 12

CLONROCHE (KNOXTOWN) 2.79 9.5 12

Near normal generally,

sunny in west

Sunshine totals for October were below

normal over much of Leinster and

Munster, but were above normal

elsewhere, particularly in the west. Totals

ranged from 64 hours at Knock Airport to

101 hours at Sherkin Island, Co. Cork,

with percentage of normal values

between 87% at Valentia Observatory and

119% at Galway (University College).

The first half of the month was much

sunnier than the second, with most stations

having their sunniest days on the 12th and

14th. The highest daily value, 9.7 hours, was

recorded at both Dungarvan (Carriglea), Co.

Waterford, on the 12th and at Shannon

Airport on the 14th. Global solar radiation

totals were between 94% of normal at Malin

Head and 110% at Belmullet.

Daily mean % of % of Most in (hours/day) average possible a day/date

County/

Station

October 2009

TToottaall SSuunnsshhiinnee

(percentage of 1961-90 normals)

00 22 44 66 88 1100

11 22 33 44 55 66 77 88 99 1100 1111 1122 1133 1144 1155 1166 1177 1188 1199 2200 2211 2222 2233 2244 2255 2266 2277 2288 2299 3300 3311

Daily sunshine values(hours)

Valentia Observatory

Dublin Airport

Malin Head

Sunshine values are not available for automatic synoptic stations

(15)

15 WORLD WEATHER

Global weather

highlights of

the month

Storms just after mid-month led to torrential rainfall in New South Wales, with widespread flooding and wind damage. Hundreds of homes in the state lost power due to fallen trees. Parts of coastal New South Wales received 400mm more rainfall than the October average. In Sicily, 230mm of rain fell in a three-hour period

on the 2nd, leading to Italy's worst mudslides in more than a decade and causing the deaths of more than 30 people. The town of Scaletta Zanclea, near Messina, was worst affected as several buildings collapsed, while floodwaters carried off cars and destroyed roads throughout the region.

Just days after India reported the driest monsoon season in almost 40 years, the southern states of Karnataka and Andhra Pradesh received their heaviest rainfall in more than 60 years. At least 286 people were killed and 2.5 million others were left homeless following the torrential downpours and subsequent flooding. Millions of acres of farmland were submerged and government officials reported total damages of more than 10 million euro. An active storm pattern for the month over

southern states of the U.S. led to widespread flooding. In Louisiana, a state of emergency was declared because of storm damage, with 35 preliminary reports of tornadoes in the region. The flooding and storms were blamed for at least three deaths and many locations in the state had their wettest October on record.

Heavy rain during the last week of the month led to flooding in southwestern Somalia, near the Kenyan border, which displaced over 15,000 people. The town of El-Waq was reported to be almost entirely under water, while there were also reports of significant losses to livestock in the flooded areas. The area had been suffering from long-term drought. October 2009

Data supplied by NOAA Climate Prediction Centre, US Department of Commerce

°C

OCTOBER RAINFALL

(percentage of

1961-1990 normal)

%

200

150

125

100

75

50

0 OCTOBER MEAN

TEMPERATURE

(difference from

1961-1990 normal)

+5

+3

+1

-1

-3

(16)

16 FEATURE

October 2009

El Niño conditions intensified from moderate to

strong over the tropical eastern Pacific Ocean

during October. Sea temperatures in the

mid-Pacific area of between 5°N and 5°S, 120°W and

170°W, reached 1.7°C above average, above the

1.5°C threshold for a strong El Niño, according to

the Australian Bureau of Meteorology. Model

forecasts predict moderate to strong El Niño

conditions during the northern hemisphere winter

of 2009-2010. Over western Europe, such

conditions are usually associated with an increase

in cyclonic activity and relatively mild weather.

For many people, El Niño brings flood-inducing rains

or crop-killing drought. El Niño, and its counterpart La

Niña, alter weather patterns across the world. The

images above show the strongest El Niño and La Niña

events of the past 20 years and their impact on rainfall

over North and South America. The top image pair

shows the El Niño event of 1997. El Niño occurs when

the ocean warms, as a result of weakening of the

west-blowing trade winds, as illustrated by the streak of

purple in the top left sea surface temperature anomaly

image. Warm surface water that would otherwise have

been blown into the western Pacific builds up in the

east. This warm water evaporates easily, warming the

atmosphere and making it easier for storms to form.

The top pair of images shows the direct correlation

between warm surface waters and rainfall. The 1997 El

Niño was unusually strong. It brought heavy rain to

northwest South America and much of the southern

United States. Meanwhile, the western Pacific cooled,

causing drought in Australia and Indonesia, just visible

as a streak of brown on the far left side of the globe in

the 1997 rainfall anomaly image.

The lower image pair shows La Niña in 1988. La Niña

occurs when the eastern Pacific off the coast of South

America cools. This cooling shows up as a streak of

blue in the sea surface temperature anomaly image,

lower left. The unusually cool ocean also cools the

atmosphere above it; this dense air doesn’t rise and form

storms easily. As a result, less rain falls over the cold

waters in the eastern equatorial Pacific. The brown tones

in the rainfall anomaly image, shown right, reveal that

the drought reached Peru and Ecuador in northwest

South America. The changes in the atmosphere alter the

flow of winds and weather systems around the world.

Globally, La Niña causes unusually heavy rain in India,

southeast Asia, Australia, and southeastern Africa, but

brings drought conditions over the southeastern United

States, the portion of that country that is usually most

affected by both El Niño and La Niña.

Sea surface temperature anomaly images compare the

average temperature observed by NOAA’s Advanced

Very High Resolution Radiometer in December, when

El Niño and La Niña events are strongest, to the

average ocean surface temperatures the sensor observed

in all of the Decembers between 1985 and 2008. The

rainfall anomaly images are derived from the Global

Precipitation Climatology Project, which blends rainfall

data from a number of satellites.

S

TRONG

E

L

N

IÑO CONDITIONS DEVELOP OVER

P

ACIFIC

El Niño 1997

La Niña 1988

Images courtesy NASA Earth Observatory,