Monthly Weather Bulletin May 2009

(1)

Much of the weather of May was unsettled,

with rain or showers on many days, heaviest in

western and northern areas. This rain was

accompanied by unusually strong winds for May

at times, particularly during the first week.

There were also short spells of dry and sunny

weather, especially at the end of the month,

when temperatures rose well above normal.

May rainfall totals were above normal at all

stations except in parts of the east and

southeast. The heaviest falls were recorded

between the 14th and 23rd, when thunderstorms

featured on several days. There was a total of

between 15 and 21 wetdays during the month

(days with 1mm or more rainfall), compared

with the average range for May of between 12

Monthlyy Weather

Bulletin

N

No

o.. 2

27

77

7 MAY 2009

W

ETTER THAN NORMAL ALMOST EVERYWHERE

;

BECOMING WARM BY END OF MONTH

Most of May was wet, but the end of the month became fine and warm, when local election canvassing took place, shown here in Kanturk, Co. Cork (picture: Irish Examiner)

INSIDE

Severe

thunderstorms

over France-

over France- page 2

page 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

Sunshine ...

14

14 W

W

or

ld

w

ea

ther ... 15

T

he w

ea

ther of

spring 2009 ...

16

Wettest Wettest spring at spring at Malin Head Malin Head since 1992 since 1992

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

For more information-tel: +353-1-8064260 fax: +353-1-8064216 [email protected]

www.met.ie/climate

(2)

and 16 wetdays. Temperatures rose

fairly steadily throughout the month,

reaching their highest values during

the last few days. Mean air

temperatures for the month overall

were above normal everywhere, by

close to one degree generally. A

number of stations recorded their

highest May temperatures for between

six and 11 years between the 28th and

31st. No air frost was recorded during

the month, but between two and five

ground frosts were measured at inland

stations, occurring as late as the 26th at

Birr. Sunshine totals were above

normal almost everywhere. The

highest daily sunshine values were on

either the 30th or 31st; Dublin Airport’s

value of 15.2 hours on the 30th was its

highest for May since 1985.

1st to 9th:

A spell of very unsettled

weather, associated with Atlantic

depressions passing close to the country.

Showers or longer spells of rain were

recorded each day and were heavy at times

in the west and north; some of the

showers were thundery between the 6th

and 9th, when hail was widely recorded.

Southwest to westerly winds were

unusually strong for May, with gusts

reaching gale force or stronger in most

areas between the 6th and 8th. Some

ground frost was recorded at first, but

temperatures were generally near or above

normal.

2 WEATHER

May 2009

F

RENCH

WINE

-

GROWING

REGIONS HIT

BY SEVERE

THUNDERSTORMS

Violent thunderstorms, producing golf

ball-sized hailstones, affected parts of

western and southwestern Europe

around the middle of the month.Among

the worst-affected areas were parts of

central and western France, where major

outbreaks of thunderstorms, with

tornadoes reported in places, occurred

between the 11th and 15th. Another

band of heavy thunderstorms led to

flooding in the south of the country on

the 22nd. Hail storms on the 11th and

13th caused damage to thousands of

hectares of vineyards in southwestern

and central France. In the Bordeaux area, crop losses on

the southern side of the region were estimated at between

30% and 80%, putting the commercial survival of some

wine growers at risk. Later in the month, a strong tornado

struck the town of Plate in eastern Germany on the

evening of the 21st, destroying over 50 buildings.

The chart shown on the right gives an indication of

thunderstorm frequency on the 13th, by measuring signals of

electrical activity in the atmosphere.These signals, known as

sferics, are detected by radio direction finders located at radar

and other sites.This system detects around half of the lightning

strikes associated with thunderstorms, depending on the

concentration of storms over an area.The colours refer to the

time of day when sferics were recorded, shown by the key on

the right of the chart.

Visible satellite image at 1800UTC on 13th

Thunderstorm activity on 13th ••PPAARRIISS

••BBOORRDDEEAAUUXX

(3)

10th to 13th:

High pressure developed to

the north of Ireland, bringing a change to

dry and mainly fair weather. Light to

moderate easterly winds brought above

normal temperatures in western areas, but

the east of the country was relatively cool,

despite mainly sunny conditions

everywhere.

14th to 27th:

A return to very showery

conditions, as areas of shallow low

pressure became slow-moving over

Ireland. All areas received some heavy falls

at times, particularly between the 14th and

18th. This period was very dull at first, but

sunny spells developed more widely, while

temperatures gradually rose above normal.

Strong southeasterly winds at first,

becoming lighter and variable in direction.

28th to 31st:

Pressure rose over the

country as an anticyclone intensified to the

east of Ireland, giving dry and very sunny

weather. Temperatures rose well above

normal, particularly in inland and western

areas. Light to moderate south to

southeasterly winds.

Wind and elements:

Mean windspeeds

for the month of between 8 and 14 knots

generally (15 and 26km/h) were above

normal everywhere and were the highest

for May for between 15 and 26 years at

several stations. Most stations measured

their strongest winds of the month on the

7th or 8th, with the month’s highest gust,

62 knots (115km/h), recorded at Belmullet

on the 7th. Thunderstorms were recorded

in the periods 4th to 9th and 14th to

21st, while hail was observed between the

6th and 9th and on the 26th.

3 WEATHER

May 2009

Above

A large anticyclone intensified as it moved northwards to the east of Ireland during the last few days of May, bringing dry, warm and sunny weather, but with some sea fog affecting coastal areas.

Visible satellite image at 1015UTC on 29th

(4)

4 WIND & ELEMENTS

CO. CARLOW

Carlow (Oak Park) 8.2 250° 24 8/14 250° 44 8/1335 0 2 6

CO. CAVAN

Ballyhaise 7.4 230° 21 7/22 220° 40 7/2039 0 4 12

CO. CLARE

Shannon Airport 10.6 240° 29 5/11 240° 42 8/0103 0 5 26 0 0 0 0 0

230° 29 7/23

CO. CORK

Roche’s Point 13.3 190° 34 16/04 200° 43 16/0450 1 5 56

Cork Airport 10.6 220° 31 7/15 220° 41 7/1416 0 6 17 0 0 0 0 6

CO. DONEGAL

Malin Head 14.8 230° 36 7/01 230° 55 7/0032 1 15 107 0 0 2 1 1

CO. DUBLIN

Dublin Airport 12.1 230° 32 8/06 270° 44 8/1419 0 7 47 0 0 0 0 2

Casement Aerodrome 11.3 220° 29 8/07 250° 44 7/1856 0 10 40 0 0 4 0 3

CO. KERRY

Valentia Observatory 10.0 260° 28 7/20 240° 40 7/1904 0 5 18 0 0 1 0 1

250° 40 8/0356

CO. MAYO

Belmullet 12.4 220° 38 7/18 220° 62 7/1706 3 13 98 0 0 5 1 2

Knock Airport 11.0 260° 28 4/12 210° 43 7/1157 0 6 32 0 0 0 0 11

CO. OFFALY

Birr 7.7 160° 21 16/09 250° 34 8/0112 0 1 1 0

CO. WESTMEATH

Mullingar 7.0 180° 18 7/14 220° 32 7/2347 0 0 0

CO. WEXFORD

Johnstown Castle 8.2 220° 20 6/15 210° 34 7/1939 0 1 2

200° 20 7/15

W

IND

((KNOTS))

E

LE

EME

ENTS

County /

Station

Valentia Observatory

Dublin Airport

May 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

NE

N

E

S

E

S

Calm: 0.0%

_{Calm: 0.0%}

2% 4%

6% 8%

2% 4%

6% 8%

(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

14

13

12

11

10

9 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 1013hPa in the north and 1016hPa in the

south, close to normal for May. Pressure was high

near the beginning and end of the month, but fell

well below normal around mid-month as a deep

depression passed close to the south coast. The

highest pressure of the month, 1034.2hPa, was

measured at Valentia Observatory on the 3rd, while

the month’s lowest value, 982.9hPa, was recorded at

Roche’s Point on the 16th.

mm

ee

ttrr

ee

ss

12

10

8

6

4

2

0

20˚N

30˚N 40˚N 50˚N 60˚N 70˚N 80˚N

H 1025

H 1020 H

1019

H 1017

L 1004

L 1012

1

1008

1016

1016 1016

1016

1

016

1024

May 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 11.3 14.9 29 3.0 7.2

M4 11.0 n/a n/a 2.9 8.2

M5 11.0 16.8 33 1.8 5.5

M6 11.7 15.8 25 n/a n/a

Malin 10.4

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)

6 AGMET / LABORATORY

CO. CARLOW

CARLOW (OAK PARK) 11.7 11.4 11.6 CO. CAVAN

BALLYHAISE 10.8 10.8 11.1 CO. CLARE

SHANNON AIRPORT 12.0 12.0 12.5 CARRON 11.8 12.0

CO. CORK

ROCHES’S POINT 11.7 11.5 11.9 FERMOY (MOOREPARK) 12.0 12.0 12.3 CORK AIRPORT 10.8 10.7 11.6 SHERKIN ISLAND 11.8 11.9 12.0 BALLINCURRIG (PEAFIELD) 11.6 11.4 12.2

CO. DONEGAL

MALIN HEAD 11.2 11.3 11.3 CO. DUBLIN

DUBLIN (PHOENIX PARK) 12.7 12.9 13.0 DUBLIN AIRPORT 11.2 11.3 11.9 CASEMENT AERODROME 11.1 11.3 11.6

CO. KERRY

VALENTIA OBSERVATORY 12.4 12.9 13.6 CO. LIMERICK

MOUNT RUSSELL 10.5 11.6 CO. LOUTH

ARDEE (BOHARNAMOE) 11.5 12.0 12.4 CO. MAYO

BELMULLET 12.0 12.5 13.7 STRAIDE 11.5 KNOCK AIRPORT 9.6 10.1 10.5

CO. MEATH

WARRENSTOWN 11.6 11.9 12.9 CO. OFFALY

BIRR 11.7 11.9 13.3 CO. TIPPERARY

FETHARD (PARSONSHILL) 10.3 11.0 CO. WATERFORD

DUNGARVAN (CARRIGLEA) 12.3 12.7 CO. WESTMEATH

MULLINGAR 11.7 11.9 12.8 CO. WEXFORD

JOHNSTOWN CASTLE 11.9 11.9 12.2 JOHN F. KENNEDY PARK 12.4 12.1 13.3 CLONROCHE (KNOXTOWN) 11.7 11.9 12.1

100mm 200mm 300mm

County/ Station

Soil Temperatures at 0900UTC

°C May 2009

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)

11.2 (+0.5)

9.6

10.8

12.0 (+1.2)

12.4 (+1.0)

11.7 (+0.5)

11.9 (+0.7)

11.7 (+0.6)

10.8 (+0.3)

11.7 (+1.4)

11.1 (+0.4)

3/23

3/13

3/12

3/14

_10/22

14/17

6/18

11/14

2/13

2/17

11/26

12.0 (+0.8)

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 0.2 0.4 0.6 0.8 1 1.2 1.4

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

(7)

7 AGMET

May 2009

Co. Cavan 1-10 37.3 - 9 8 14.1 6.3 10.2 - 2.5 10 0 58 13 -0.5 10 1 - - 61.5 - Cavan (Loreto) 11-20 46.2 - 8 8 13.8 6.9 10.4 - 3.4 11 0 60 13 0.1 11 0 - - 51.5 -

21-end 17.3 - 6 3 17.7 8.7 13.2 - 3.4 26 0 97 41 -0.5 26 1 - - 62.5 -

month 100.8 - 23 19 15.3 7.3 11.3 - 2.5 10 0 215 66 -0.5 26 2 - - 175.5 -

Co. Cork 1-10 4.7 - 5 3 14.5 6.8 10.7 - 3.3 2 0 63 16 2.5 3 0 11.1 11.3 57.4 - Fermoy 11-20 64.5 - 7 7 14.2 7.6 10.9 - 4.7 12 0 65 16 1.1 12 0 11.4 11.7 46.4 - 21-end 17.8 - 6 4 17.8 8.3 13.1 - 3.6 26 0 96 40 1.9 26 0 13.5 13.6 75.6 -

month 87.0 128 18 14 15.6 7.6 11.6 1.1 3.3 2 0 224 73 1.1 12 0 12.0 12.3 179.4 103

Co. Donegal 1-10 75.7 - 9 8 13.1 5.5 9.3 - -0.2 10 1 51 9 -1.9 10 1 - - - - Glenties 11-20 23.4 - 8 6 15.0 5.8 10.4 - 2.6 12 0 61 15 -2.0 12 2 - - - - 21-end 25.5 - 6 6 17.8 8.9 13.4 - 3.3 21 0 98 42 1.1 21 0 - - - -

month 124.6 137 23 20 15.4 6.8 11.1 1.1 -0.2 10 1 210 65 -2.0 12 3 - - - -

Co. Kerry 1-10 14.7 - 6 5 14.9 7.0 11.0 - 5.0 10 0 66 18 2.1 3 0 - - 62.2 - Ardfert 11-20 49.1 - 8 7 14.9 6.1 10.5 - 3.2 11 0 62 17 2.0 11 0 - - 51.8 - 21-end 32.5 - 6 5 18.2 9.2 13.7 - 6.5 26 0 102 45 4.1 26 0 - - 79.8 -

month 96.3 - 20 17 16.1 7.5 11.8 1.2 3.2 11 0 230 79 2.0 11 0 - - 193.8 -

Co. Louth 1-10 20.5 - 8 8 15.4 6.5 11.0 - 3.1 10 0 66 20 0.3 10 0 10.1 11.6 - - Ardee 11-20 46.9 - 8 8 14.6 7.7 11.2 - 6.5 16 0 67 17 2.0 11 0 10.7 11.7 - -

21-end 4.6 - 3 2 19.4 8.4 13.9 - 4.5 26 0 104 48 2.5 26 0 13.6 13.7 - -

month 72.0 120 19 18 16.5 7.6 12.1 2.0 3.1 10 0 238 85 0.3 10 0 11.5 12.4 - -

Co. Waterford 1-10 7.4 - 5 5 15.3 6.9 11.1 - 3.5 7 0 68 21 1.0 7 0 - 11.8 65.4 - Dungarvan 11-20 71.1 - 8 8 14.1 8.1 11.1 - 5.9 12 0 67 16 4.1 13 0 - 11.9 64.5 - 21-end 14.2 - 5 4 17.4 8.5 13.0 - 3.5 24 0 95 38 2.6 24 0 - 14.1 94.1 -

month 92.7 - 18 17 15.7 7.9 11.8 1.0 3.5 24 0 229 75 1.0 7 0 - 12.7 224.0 123

Co. Wexford 1-10 6.5 - 6 5 14.6 6.2 10.4 - 3.0 2 0 60 15 -1.2 3 1 11.1 12.6 53.8 - J.F.K. Park 11-20 57.1 - 8 7 13.0 7.8 10.4 - 5.6 12 0 60 11 2.0 12 0 11.7 12.7 46.5 - 21-end 13.4 - 4 3 17.3 8.4 12.9 - 3.2 26 0 93 37 1.0 26 0 14.0 14.4 81.6 -

month 77.0 107 18 15 15.0 7.5 11.3 0.7 3.0 2 0 214 63 -1.2 3 1 12.4 13.3 181.9 106

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

County/ 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) Clare Kilmaley 132.7 n/a

Cork Fermoy (Moorepark) 87.0 87.3

Kerry Valentia Observatory 100.1 78.2

Kildare Poulaphuca 77.9 n/a

Mayo Newport (Furnace) 128.8 62.5

Offaly Derrygreenagh 69.9 59.6

Waterford Dungarvan (Carriglea) 92.7 89.0

Wexford J.F.K. Park 77.0 83.7 23.6 - 0 3 23.6 - 0 14 29.5 - 0 11

76.7

14.1 4 4 -17.1 - 0 18 21.8 0

-53.0 Co. Kerry

1-10 Valentia Obs. 11-20

21-end

month Co. Wexford

1-10 Johnstown Castle 11-20 21-end

month

P

P..E

E..

(Penman)

G

LLOOBBAALL

S

OOLLAARR

R

AADDIIAATTIIOONN (MJ/sq.m.)

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

Birr

Co.Westmeath

Mullingar*

Co.Wexford

Johnstown Castle*

146.72 127.87 210.46 485.05

152.46 150.61 186.33 489.40

global solar radiation values for stations marked * are provisional

171.08 182.22 214.36 567.66

152.07 179.34 201.64 533.05

n/a 131.40 233.35 n/a

151.99 159.66 205.69 517.34

166.17 179.35 195.27 540.79

149.93 155.99 211.26 517.18

142.90 148.25 199.75 490.90

165.24 138.91 210.17 514.32 73

68

78

72

71

73 75

75

68 13

76

70

(8)

Friday 1st:Wet and windy weather in Atlantic coastal areas moved eastwards overnight and during the morning, clearing the east coast around midday. Clearer weather with well-scattered showers and sunny spells followed. Many areas had a dry afternoon and evening, with showers becoming confined to northwestern areas. Winds were southwesterly, moderate to fresh and gusty, easing by evening.

Rainfall: 1 to 10mm, heaviest at Belmullet, 1mm at Dublin Airport Temperature: max. 13°C to 16°C, min. 5°C to 9°C, no ground frost Sunshine: 6 to 10 hours, sunniest at Shannon Airport, 6 hours at Malin Head

Saturday 2nd:A cool start to the day, with some scattered showers. Cloud built up in western coastal counties by the afternoon and showery rain developed along the west coast by evening. This rain spread eastwards during the evening and early night, clearing the east coast by midnight. Winds were moderate southwesterly.

Rainfall: trace to 7mm, heaviest at Shannon Airport, trace at Johnstown Castle Temperature: max. 13°C to 15°C, min. 3°C to 7°C, ground temperatures

below zero at Ballyhaise and Valentia

Sunshine: 7 to 11 hours, sunniest at Knock Airport, 7 hours at Valentia

Sunday 3rd:The morning was mostly dry. Some scattered showers developed in the afternoon, mainly in west Munster, Connacht and Ulster. A cool day with temperatures a little below normal, despite long sunny spells. By nightfall it became breezy and cloudy with rain and drizzle developing in the northwest and north. Winds were moderate, west to northwesterly.

Rainfall: nil to 1mm generally, 4mm at Malin Head

Temperature: max. 11°C to 14°C, min. 2°C to 7°C, ground temperatures

down to -1°C at Claremorris and Birr

Sunshine: 9 to 12 hours, sunniest at Dublin Airport, 9 hours at Cork Airport

Monday 4th: Rain and drizzle over the northern half of the country overnight. It was a dull, misty and breezy day generally with the rain and drizzle becoming more widespread. This rain was heavy and persistent at times in the north, while parts of the south and southeast remained dry with a few short sunny spells. The rain became light and intermittent as the day progressed. Mild. Winds were southwest to westerly, moderate to fresh and gusty.

Rainfall: nil to 5mm, heaviest at Malin Head, nil at Cork Airport Temperature: max. 11°C to 15°C, min.5°C to 10°C, no ground frost Sunshine: nil to trace generally, < 1 hour at Cork Airport

Tuesday 5th:Persistent light rain and drizzle in Ulster and north Connacht throughout the period. Rain spread into north Leinster in the afternoon and evening, remaining dry further south. Overcast in the northern half of the country, progressively more sunshine further south. Winds were generally moderate southwesterly but fresh or strong at times in the north and west.

Rainfall: nil to 16mm, heaviest at Malin Head, nil in the south Temperature: max. 12°C to 17°C, min. 9°C to 11°C, no ground frost Sunshine: nil to 6 hours, sunniest at Cork Airport, nil in the north and west

Wednesday 6th: Earlyrain in the northwest, generally dry elsewhere. Mainly overcast with just a few sunny spells here and there. Another band of rain reached the northwest in the afternoon and spread southeastwards. This rain, while giving some heavy falls in the north, gradually eased as it progressed. Winds were southwesterly, moderate to strong, up to gale force with stronger gusts.

Rainfall: <1 to 19mm, heaviest at Malin Head, <1mm at Roches Point Temperature: max. 11°C to 16°C, min. 5°C to 9°C, no ground frost Sunshine: nil to 2 hours, sunniest at Belmullet, nil at Valentia

Thursday 7th:Showers in the west and north overnight, mostly dry elsewhere. This pattern continued into the morning. During the afternoon and evening the showers became more frequent and heavy, with some of hail or thunder, especially in the northwest. Sunny spells, particularly in the east. Winds were southwesterly, very strong with some very high gusts in places.

Rainfall: 1 to 11mm, heaviest at Malin Head, 1mm at Roches Point Temperature: max. 9°C to 14°C, min. 4°C to 8°C, no ground frost

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

Friday 8th:Showers overnight, mostly in the west and north of the country. During the early morning the showers became more widespread and heavy, with hail in places. The showers continued during the afternoon over most of the country, again heavy and with hail, but with sunny spells also. The showers

became mostly confined to west and north by evening. Winds were southwesterly, moderate to strong and gusty throughout.

Rainfall: trace to 11mm, heaviest at Ballyhaise, trace at Roches Point Temperature: max. 11°C to 14°C, min. 4°C to 7°C, no ground frost Sunshine: 9 to 12 hours, sunniest at Belmullet, 9 hours at Valentia

Saturday 9th:Showers during the early hours, most frequent in the west and north. During the morning, rain spread eastwards across the country, with a clearance following quickly. Some sunny spells developed. Showers in western areas during the early afternoon, but by mid-afternoon all places became dry with sunshine. Generally dry during the evening with just the odd shower along the west coast. Winds were moderate southwesterly, becoming light.

Rainfall: <1 to 10mm, heaviest at Ballyhaise, <1mm at Johnstown Castle Temperature: max. 11°C to 14°C, min. 4°C to 8°C, ground temperatures

below zero at Casement Aerodrome

Sunshine: 2 to 11 hours, sunniest at Knock Airport, 2 hours at Cork Airport

Sunday 10th:Dry with clear skies overnight, light winds and some ground frost in parts. The morning was sunny in most areas, a bit more cloudy along the south coast. The afternoon and evening continued dry with long sunny spells. The night continued clear and dry with light southwesterly winds.

Rainfall: nil to trace generally, 1mm at Johnstown Castle

down to -2°C at Knock Airport

Sunshine: 5 to 14 hours, sunniest at Malin Head, 5 hours at Valentia

Monday 11th:Dry and cold overnight with a touch of ground frost. Milder along southern and eastern coastal areas. After a cool start it was a warm, sunny and breezy day generally. Slightly cooler near southern and southeastern coasts due to the easterly breezes and some patchy cloud. Light variable winds overnight became moderate to fresh and gusty easterly for the rest of the day.

Rainfall: nil

Temperature: max.13°C to 19°C, min. 3°C to 9°C, ground temperatures

down to -1°C at Ballyhaise

Sunshine: 12 to 15 hours, sunniest at Knock Airport, 12 hours at Valentia

Tuesday 12th:Mostly mild and dry overnight. A sunny start to the day countrywide with most sunshine in northern and western areas. Moderate easterly breezes were gusty at times, keeping temperatures lower in eastern areas during the day. It was dry throughout the country during the evening and night with some moderate gusty winds in northern areas.

Rainfall: nil

below zero at Ballyhaise

Sunshine: 9 to 15 hours, sunniest at Malin Head, 9 hours at Dublin Airport

Wednesday 13th:Warm morning sunshine in the north and west, while the south and east were overcast. By noon, outbreaks of light rain moved into southern areas and spread northwards to affect most places. Rainfall amounts were small except in eastern areas in the late evening. Winds were southeasterly, light to moderate.

Rainfall: nil to 1mm generally, 4mm at Dublin Airport

Temperature: max.9°C to 18°C, min. 5°C to 10°C, ground temperatures

down to -2°C at Casement Aerodrome

Sunshine: nil to 8 hours, sunniest at Malin Head, nil at Cork Airport

Thursday 14th: Relatively mild and humid overnight, with outbreaks of

rain and drizzle, lingering for most of the day. The rain was heavy and thundery at times, particularly in parts of Munster. Winds were light and variable or easterly generally but were fresh and gusty easterly on northern and northeastern coasts.

Rainfall: trace to 16mm, heaviest at Valentia, trace at Malin Head Temperature: max. 11°C to 15°C, min. 7°C to 10°C, no ground frost Sunshine: nil to trace

Friday 15th:Rain in most parts overnight. The rain moved slowly northwards during the day, followed by clearer, drier weather with some sunny spells. Another band of dull, wet weather moved into the southwest in the evening and began to move northwards. Winds were variable in direction, moderate to fresh and gusty.

Rainfall: trace to 16mm, heaviest at Dublin Airport, trace at Shannon Airport Temperature: max. 10°C to 13°C, min. 3°C to 9°C, no ground frost Sunshine: nil to 6 hours ,sunniest at Cork Airport, nil at Belmullet

(9)

Saturday 16th: Rain or showers affected all areas at times during the night.

This pattern persisted throughout the day and evening, with heaviest falls in

the south. Some sunny periods, but temperatures near or below normal. Winds were southeasterly, up to gale force with strong gusts.

Rainfall: 3 to 14mm, heaviest at Cork Airport, 3mm at Casement Aerodrome Temperature: max. 11°C to 14°C, min. 3°C to 9°C, no ground frost

Sunshine: <1 to 6 hours, sunniest at Casement Aerodrome, <1 hour at

Shannon Airport

Sunday 17th:Overnight showers in the southeast spread northwards during the day and intensified, with some prolonged rain in places during the late afternoon. Breezy and cool with a few sunny spells also, mainly in the north. Showers continued during the evening. Winds were moderate, variable.

Rainfall: 1 to 19mm, heaviest at Johnstown Castle, 1mm at Malin Head Temperature: max. 10°C to 14°C, min. 5°C to 8°C, no ground frost Sunshine: trace to 6 hours, sunniest at Malin Head, trace at Shannon Airport

Monday 18th:Heavy showers continued throughout the night in parts of the midlands and east. Showers eased for a while during the morning but became widespread, heavy and thundery during the afternoon and evening. Prolonged sunshine in the south, with sunshine between the showers elsewhere. Winds were variable, moderate to fresh, becoming westerly and easing later.

Rainfall: nil to 15mm, heaviest at Carlow (Oak Park), nil at Belmullet Temperature: max. 12°C to 15°C, min 7°C to 10°C, no ground frost Sunshine: 1 to 7 hours, sunniest at Cork Airport, 1 hour at Valentia

Tuesday 19th:Overnight showers, some heavy in places. The showers became more scattered during the morning, but developed again in the afternoon and became heavy in places, with some thundery downpours in the east. Sunny spells in all areas, mainly in the northwest and north. The showers continued throughout the evening. Winds were light and variable.

Rainfall: nil to 7 hours, heaviest at Shannon Airport, nil at Belmullet Temperature: max. 13°C to 17°C, min. 6°C to 9°C, no ground frost Sunshine: 3 to14 hours, sunniest at Belmullet, 3 hours at Knock Airport

Wednesday 20th:Clear at first with sunny spells during the morning in the west and north, cloudier in the east and south with showers. This pattern continued into the afternoon, with some showers turning heavy. Dry in most parts by midnight. Winds were generally light, southwesterly in direction.

Rainfall: nil to 11mm, heaviest at Cork Airport

Temperature: max. 13°C to 16°C, min. 3°C to 9°C, no ground frost Sunshine: 3 to 13 hours, sunniest at Belmullet, 3 hours at Dublin Airport

Thursday 21st:Widespread showers during the late morning continued into the afternoon with some thunder also. Sunny spells in all areas, mainly in the north. Outbreaks of rain in the southwest in the early evening spread over the southern half of the country. Winds were light to moderate southwesterly, veering westerly during the day, gusty at times.

Rainfall: nil to 6mm, heaviest at Valentia, nil at Malin Head Temperature: max. 13°C to 15°C, min. 5°C to 9°C, no ground frost Sunshine: 6 to 13 hours, sunniest at Malin Head, 6 hours at Shannon Airport

Friday 22nd: Overnight rain, mainly confined to the southern half of the

country, gradually moved eastwards, clearing the east coast around noon. Sunshine in the north during the morning and in many parts during the afternoon, once the rain cleared. A few showers in the west by late evening. Winds were light to moderate, easterly, veering southerly later.

Rainfall: nil to 6mm, heaviest at Valentia, nil at Malin Head Temperature: max. 13°C to 19°C, min. 6°C to 11°C, no ground frost Sunshine: 1 to 12 hours, sunniest at Malin Head, 1 hour at Valentia

Saturday 23rd:Rain reached the west coast around dawn and spread northeastwards, clearing the country by mid-afternoon. The rain was heaviest in the west and southwest. Sunshine in all areas also, particularly in the southwest and south. Dry throughout by evening. Winds were light to moderate, westerly backing southwesterly later.

Rainfall: <1 to 12mm, heaviest at Claremorris, <1mm at Dublin Airport Temperature: max. 13°C to 16°C, min. 6°C to 9°C, no ground frost Sunshine: 3 to 10 hours, sunniest at Valentia, 3 hours at Malin Head

Sunday 24th: It was a dry, warm and sunny day over most of the country

with afternoon temperatures above normal. However it was cooler and

cloudy in the west and northwest and along Atlantic coasts. There was some patchy rain or drizzle near northwestern coasts. Winds were south to southwesterly, moderate to fresh and gusty at times.

Rainfall: nil to trace

below zero at Casement Aerodrome

Sunshine: nil to 15 hours, sunniest at Cork Airport, nil at Knock Airport

Monday 25th:A band of light rain and drizzle in the northwest moved very slowly southeastwards overnight and during the day. This rain became progressively light and patchy as it crossed the country, clearing the east coast by late evening. Sunny in the west and southwest, cloudier further east. Winds were light southerly, veering westerly with the clearance, while remaining light.

Rainfall: nil to 6mm, heaviest at Malin Head, nil at Johnstown Castle Temperature: max. 13°C to 18°C, min. 6°C to 10°C, no ground frost Sunshine: trace to 8 hours, sunniest at Belmullet, trace at Malin Head

Tuesday 26th:After a mainly dry night, showers in western areas became more extensive and reached eastern areas by midday. Showers in most areas during the afternoon, heavy in places. By evening a frontal trough reached the west coast, bringing longer periods of rain. The showers died out in most eastern areas. Some long periods of sunshine. Winds were light westerly, freshening during the late morning, up to gale force at times, before easing later.

Rainfall: nil to 8mm, heaviest at Valentia, nil at Dublin Airport

down to -2°C at Birr

Sunshine: 9 to 13 hours, sunniest at Dublin Airport, 9 hours at Belmullet

Wednesday 27th:Cloudy with rain and drizzle in many places overnight, heaviest in the south. The rain and drizzle continued during the morning, with some dry periods also. The rain cleared most places by late afternoon. A few sunny spells in the south and east. Winds were westerly, light to moderate.

Rainfall: 1 to 12mm, heaviest at Valentia, 1mm at Dublin Airport Temperature: max. 13°C to 19°C, min. 8°C to 10°C, no ground frost Sunshine: nil to <1 hour generally, 3 hours at Cork and Dublin Airport

Thursday 28th:Cloudy with some drizzle in places overnight and some mist also. Cloudy during the early morning, but with sunny spells in places during the afternoon. The sunny spells continued during the afternoon and it was warm. Winds were light to moderate, variable in direction.

Temperature: max. 14°C to 22°C, min. 9°C to 13°C, no ground frost Sunshine: trace to 12 hours, sunniest at Shannon Airport, trace at Valentia

Friday 29th:The morning was dry and sunny over most of the country, however, mist and cloud persisted in the southeast and south. Dry, sunny and warm over most of the country during the afternoon with some cloud in the south. Remaining dry and clear during the evening and night with some fog along the east coast at times. Winds were southerly, light to moderate.

Temperature: max. 15°C to 23°C, min. 7°C to 12°C, no ground frost Sunshine: 4 to 14 hours, sunniest at Valentia, 4 hours at Cork Airport

Saturday 30th:Clear or sunny spells everywhere apart from the northwest coast. Warm and generally dry everywhere. Cloud persisted in the northwest during the evening with occasional showers over Connacht. Fog also in the northwest as the day ended, with calm conditions in most places. Light to moderate southeasterly winds.

Rainfall: nil generally, <1mm at Knock Airport

Temperature: max. 16°C to 23°C, min. 8°C to 14°C, no ground frost Sunshine: 5 to 15 hours generally, sunniest in the east, < 1 hour at Belmullet

Sunday 31st:Dry with some mist or fog patches overnight. After any mist or fog cleared it turned out to be a dry, warm and sunny day. Temperatures were well above normal generally but were a few degrees cooler near east and southern coasts due to onshore breezes. Continuing dry and mild for the evening. Light easterly winds were moderate at times on eastern and northeastern coasts.

Rainfall: nil

Temperature: max. 18°C to 24°C, min. 5°C to 12°C, no ground frost Sunshine: 11 to 15 hours, sunniest at Shannon Airport, 11 hours at Belmullet

9 DIARY

(10)

May rainfall totals were above

normal almost everywhere and

were well above normal in parts

of the west and northwest.

Given the showery nature of

much of the month’s rainfall,

there was a wide variation in

totals across the country. Totals

ranged from 40mm, or 60% of

normal, at Roche’s Point to

203mm, or 225% of normal, at

Carron, Co. Clare, where it was

the wettest May since records

began there in 1974.

Some parts of the country recorded

heavy daily falls during the first

week, particularly the north and

northwest, but at the majority of

the stations the wettest weather of

the month was in the period 14th to

19th. Carron also recorded the

highest daily fall of the month,

32.6mm on the 17th, the highest

May fall at the station since 1993.

There were between 12 and 17

wetdays recorded during the month

(days with 1mm or more of rainfall) at

most eastern and southern stations,

but between 18 and 22 wetdays

were measured in parts of the west

and north, well above the normal

range for May in these areas of

between 14 and 17 wetdays.

CO. CARLOW

CARLOW (OAK PARK) 65.2 111 14.9 18 21 13

CO. CAVAN

BALLYHAISE 112.5 170 14.2 8 23 19 CAVAN LORETO COLLEGE 100.8 12.7 8 23 19

CO. CLARE

SHANNON AIRPORT 98.8 165 15.3 17 21 15 CARRON 202.9 225 32.6 17 26 21

CO. CORK

ROCHE’S POINT 40.2 60 9.0 14 17 10 FERMOY (MOOREPARK) 87.0 128 18.5 14 18 14 CORK AIRPORT 85.7 102 15.2 15 16 15 SHERKIN ISLAND 93.3 130 16.8 26 17 13 BALLINCURRIG (PEAFIELD) 106.3 22.8 20 20 17

CO. DONEGAL

MALIN HEAD 92.8 157 14.7 5 7 21 16 GLENTIES HATCHERY 124.6 137 17.9 4 23 20 BALLYSHANNON(CATHLEEN'S FALL) 100.4 148 16.6 5 23 20

CO. DUBLIN

DUBLIN (PHOENIX PARK) 61.4 108 12.1 14 20 14 DUBLIN AIRPORT 75.0 15.4 14 22 13 CASEMENT AERODROME 51.6 89 12.5 14 19 13 DUBLIN (MERRION SQUARE) 64.9 120 11.8 14 19 14

CO. GALWAY

GALWAY (UNIV.COLL.) 127.7 170 18.2 8 21 20 MAAM VALLEY 201.0 24.4 16 24 22 CONNEMARA NATIONAL PARK 123.1 127 19.7 22 20 16 BALLYGAR 96.6 138 12.8 8 22 17

CO. KERRY

VALENTIA OBSERVATORY 100.1 112 18.1 26 21 16 ARDFERT (LISCAHANE) 96.3 13.7 14 20 17

CO. LIMERICK

MOUNT RUSSELL 103.2 14.0 19 18 18

CO. LOUTH

ARDEE (BOHARNAMOE) 72.0 120 8.8 19 19 18

CO. MAYO

BELMULLET 81.3 120 11.8 7 22 15 STRAIDE 83.5 111 13.5 7 21 17 KNOCK AIRPORT 111.6 14.9 14 24 21

CO. MEATH

WARRENSTOWN 78.2 124 12.5 14 20 16

CO. OFFALY

BIRR 66.7 109 11.3 17 20 16 DERRYGREENAGH 69.9 108 14.0 14 21 16

CO. SLIGO

ARDTARMON 101.5 15.2 7 23 19

CO. TIPPERARY

FETHARD (PARSONSHILL) 93.6 14.6 20 23 18

CO. WATERFORD

WATERFORD (TYCOR) 69.7 100 11.8 15 17 12 DUNGARVAN (CARRIGLEA) 92.7 16.7 17 18 17

CO. WESTMEATH

MULLINGAR 69.8 96 11.7 14 22 17

CO. WEXFORD

JOHNSTOWN CASTLE 59.9 94 16.6 17 16 12 JOHN F. KENNEDY PARK 77.0 107 13.6 14 18 15 CLONROCHE (KNOXTOWN) 76.9 14.2 17 21 17

County/

Station

Total % of

Number of

Amount 1961-90 Most in

Raindays Wetdays

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

Wetter than

normal almost

everywhere

(11)

11 RAINFALL

May 2009

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

Valentia Observatory

Dublin Airport

Birr

Daily 0-24h rainfall values(mm)

TToottaall rraaiinnffaallll

((m

mm

m))

PPeerrcceennttaaggee ooff nnoorrm

maall rraaiinnffaallll

< 100% 100 - 125%

125 - 150% 150 - 200%

> 200% 50 - 75

75 - 100 100 - 150 150 - 200

(12)

12 TEMPERATURE

Mean air temperatures for the month varied

between 9.9°C at Knock Airport and 12.4°C at

Waterford (Tycor). They were around a degree

above normal generally and close to two degrees

higher than normal in some eastern areas.

Temperatures were close to or a little above normal

for much of May, but rose well above normal during

the last week, especially in western areas. Ground

frost was recorded in many inland areas in the

periods 2nd to 3rd and 9th to 13th, but was generally

slight. The total of between 2 and 5 ground frosts in

these areas was a little below normal for May. The

lowest air temperature of the month, -0.7°C, was

recorded at Straide, Co. Mayo, on the 10th, while the

lowest grass minimum value of -2.4°C was measured

at Knock Airport on the same day. All stations

recorded their highest temperatures of the month in

the period 27th to 31st; these were the highest May

values for between six and 12 years in several places.

The month’s highest air temperature, 26.5°C, was

recorded at Galway (University College) on the 31st;

this was the highest May value on record at the

station, where observations began in 1966, and the

highest for May at any station since 1997.

Warmer than normal,

especially in eastern half

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

00 55 1100 1155

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)

May 2009

z

Valentia Observatory

z

Dublin Airport

z

Birr

M

Meeaann TTeem

mppeerraattuurree

(difference from 1961-90 normals)

(13)

13 TEMPERATURE

CO. CARLOW

CARLOW (OAK PARK) 15.6 7.5 11.6 1.0 22.3 28 3.9 3 -0.3 13 0 1

CO. CAVAN

BALLYHAISE 14.5 7.1 10.8 21.6 30 2.3 10 -1.3 11 0 4 CAVAN LORETO COLLEGE 15.3 7.3 11.3 22.7 30 2.5 10 -0.5 10 26 0 2

CO. CLARE

SHANNON AIRPORT 15.5 8.5 12.0 0.5 24.2 31 4.6 3 -0.4 3 0 1 CARRON 14.2 7.1 10.7 0.7 23.4 31 3.6 2 4 -1.8 2 0 2

CO. CORK

ROCHE’S POINT 14.0 8.5 11.3 0.4 19.1 27 5.6 3 1.9 24 0 0 FERMOY (MOOREPARK) 15.6 7.6 11.6 1.1 21.0 31 3.3 2 1.1 12 0 0 CORK AIRPORT 14.0 7.0 10.5 0.2 18.5 31 3.3 3 -0.3 3 0 2 SHERKIN ISLAND 14.3 8.9 11.6 0.6 20.0 31 6.1 13 1.9 2 0 0 BALLINCURRIG (PEAFIELD) 15.5 6.2 10.9 21.0 31 2.1 2 -1.2 2 0 2

CO. DONEGAL

MALIN HEAD 13.7 8.1 10.9 0.8 22.2 30 3.8 8 2.5 8 0 0 GLENTIES HATCHERY 15.4 6.8 11.1 1.1 25.5 31 -0.2 10 -2.0 12 1 3 BALLYSHANNON(CATHLEEN'S FALL) 15.1 7.7 11.4 0.9 23.8 30 3.1 11 0

CO. DUBLIN

DUBLIN (PHOENIX PARK) 16.0 7.6 11.8 1.4 22.4 29 3.3 3 0.0 3 0 0 DUBLIN AIRPORT 15.1 7.3 11.2 20.8 28 3.2 11 -0.9 11 0 2 CASEMENT AERODROME 15.3 7.4 11.4 1.0 22.8 29 3.5 3 -1.7 13 0 3 DUBLIN (MERRION SQUARE) 15.3 9.3 12.3 0.7 20.7 28 5.6 3 0

CO. GALWAY

GALWAY (UNIV.COLL.) 15.7 7.8 11.8 0.7 26.5 31 2.5 10 -0.9 10 0 4 MAAM VALLEY 15.1 7.4 11.3 24.2 31 2.5 10 -0.6 10 0 1 CONNEMARA NATIONAL PARK 14.5 7.7 11.1 21.0 29 4.0 16 0 BALLYGAR 15.6 6.6 11.1 24.6 30 1.0 0 0

CO. KERRY

VALENTIA OBSERVATORY 14.7 9.0 11.9 0.9 23.8 31 5.2 2 -0.4 2 0 1 ARDFERT (LISCAHANE) 16.1 7.5 11.8 1.2 25.1 31 3.2 11 2.0 11 0 0

CO. LIMERICK

MOUNT RUSSELL 14.9 7.3 11.1 23.5 31 3.7 12 -0.8 12 0 1

CO. LOUTH

ARDEE (BOHARNAMOE) 16.5 7.6 12.1 2.0 22.0 29 3.1 10 0.3 10 0 0

CO. MAYO

BELMULLET 14.4 8.3 11.4 0.9 21.9 29 2.7 10 -1.6 10 0 2 STRAIDE 15.5 6.3 10.9 0.6 24.0 31 -0.7 10 -1.5 26 1 1 KNOCK AIRPORT 13.4 6.4 9.9 22.7 31 2.1 3 -2.4 10 0 1

CO. MEATH

WARRENSTOWN 15.8 7.6 11.7 1.4 22.6 29 2.9 10 1.1 10 0 0

CO. OFFALY

BIRR 15.6 7.5 11.6 1.0 24.4 31 2.4 3 -1.9 26 0 5 DERRYGREENAGH 16.0 6.0 11.0 1.0 23.0 31 1.2 9 -0.7 26 0 1

CO. SLIGO

ARDTARMON 15.8 7.7 11.8 23.9 31 3.4 10 0.9 10 0 0

CO. TIPPERARY

FETHARD (PARSONSHILL) 14.9 7.1 11.0 22.3 31 3.0 3 1.8 8 0 0

CO. WATERFORD

WATERFORD (TYCOR) 16.1 8.7 12.4 1.5 22.7 31 5.0 2 0 DUNGARVAN (CARRIGLEA) 15.7 7.9 11.8 1.0 20.2 31 3.5 2 7 1.0 7 0 0

CO. WESTMEATH

MULLINGAR 15.2 7.0 11.1 1.0 22.1 30 2.2 10 -0.9 10 0 2

CO. WEXFORD

JOHNSTOWN CASTLE 14.4 8.3 11.4 1.1 19.1 30 4.2 2 1.2 2 0 0 JOHN F. KENNEDY PARK 15.0 7.5 11.3 0.7 21.0 31 3.0 2 -1.2 3 0 1 CLONROCHE (KNOXTOWN) 15.1 6.7 10.9 21.3 31 2.0 2 n/a 0 n/a

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

°C

(14)

14 SUNSHINE

CO. CAVAN

CAVAN LORETO COLLEGE 5.66 35 12.8 11

CO. CLARE

SHANNON AIRPORT 6.59 114 42 15.0 31

CO. CORK

FERMOY (MOOREPARK) 5.79 103 37 14.5 12

CORK AIRPORT 6.24 104 40 14.8 31

SHERKIN ISLAND 6.80 100 44 15.0 31

BALLINCURRIG (PEAFIELD) 6.74 14.8 31

CO. DONEGAL

MALIN HEAD 7.14 115 44 14.8 11 12

BALLYSHANNON(CATHLEEN'S FALL) 6.34 118 40 14.2 31

CO. DUBLIN

DUBLIN AIRPORT 6.96 115 44 15.2 30

CASEMENT AERODROME 6.89 119 43 15.2 30

CO. GALWAY

GALWAY (UNIV.COLL.) 6.81 117 43 14.5 12

CO. KERRY

VALENTIA OBSERVATORY 5.26 91 34 14.1 31

ARDFERT (LISCAHANE) 6.25 40 12.9 12 31

CO. MAYO

BELMULLET 6.63 108 41 14.7 11

STRAIDE 6.72 14.6 12

KNOCK AIRPORT 6.02 14.9 11

CO. OFFALY

BIRR 6.40 120 40 14.5 12

CO. WATERFORD

DUNGARVAN (CARRIGLEA) 7.23 123 46 14.5 12 31

CO. WEXFORD

JOHN F. KENNEDY PARK 5.87 106 37 12.9 31

CLONROCHE (KNOXTOWN) 6.89 14.8 31

Sunnier than normal

almost everywhere

Sunshine totals for May were above

normal except in the extreme southwest.

Totals ranged from 163 hours, or 91% of

normal, at Valentia Observatory, to 224

hours, or 123% of normal, at Dungarvan

(Carriglea), Co. Waterford. It was the

sunniest May for eight or nine years at

some stations.

Sunshine was distributed fairly evenly

through the month, with the sunniest days

during the periods 10th to 12th and 29th to

31st. Both Dublin Airport and Casement

Aerodrome measured the highest daily value

of the month, 15.2 hours on the 30th; at

Dublin Airport, this was the sunniest May

day since 1985. Global solar radiation totals

ranged from 91% of normal at Valentia

Observatory to 104% at Belmullet.

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

County/

Station

May 2009

TToottaall SSuunnsshhiinnee

(difference from 1961-90 normals)

00 44 88 1122 1166

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

Birr

(15)

15 WORLD WEATHER

Global weather

highlights of

the month

In eastern Australia, a severe storm produced torrential rain and damaging winds on the 20th. Winds of 100km/h brought down trees and electric poles, causing widespread power outages. Flooding from heavy rainfall forced nearly 5000 residents in northern New South Wales to evacuate their homes. In the state of Queensland, a state of emergency was declared, while in New South Wales six areas were declared disaster zones.

Typhoon Kujira formed near the eastern Philippine Islands as a tropical depression on the 2nd, strengthening to a tropical storm that same day. The storm’s heavy rain produced floods and triggered landslides that left 33 people dead and affected over 246,000 people. As Kujira tracked northeastwards it strengthened into a typhoon on the 4th, with maximum sustained winds of 213km/h. On the 25th, temperatures reached 32°

or 33°C in parts Switzerland and the western half of Germany. An eastward-moving cold front met the very warm air over southern Germany, Switzerland and Austria on the 26th, producing severe thunderstorms. Hail, damaging winds and flooding rain caused loss of property and least one death. Falls of rain and hail amounted to 65mm at Konstanz; the city was covered with at least 10cm of hail for a time. Severe floods in northeastern Brazil, caused by

heavy rainfall since April, continued throughout much of May, affecting 426,000 people and leading to 59 fatalities. On the 28th, a dam ruptured in Piaui state as the heavy rains swelled the reservoir; the resulting wall of water destroyed nearly 120 homes and claimed the lives of 15 people. Violent storms across the midwestern United States on the 8th killed six people and damaged hundreds of homes. The storms affected Kansas, Illinois, Kentucky, and Missouri, with 47 tornadoes reported. A second episode of severe weather affected the Midwest on the 13th; Kirksville, Missouri, was hardest hit with three fatalities reported.

May 2009

MAY RAINFALL

(percentage of

1961-1990 normal)

MAY MEAN TEMPERATURE

(difference from

1961-1990 normal)

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

%

200

150

125

100

75

50

0 +5

+3

+1

-1

-3

(16)

16 SPRING 2009 SUMMARY

May 2009

Spring rainfall totals were above normal almost

everywhere, with percentage of normal values

between 92% and 147% of normal. Although

March was relatively dry except in the northwest,

spells of wet weather during both April and May

brought seasonal totals above normal except in

coastal areas of the south and east. Malin Head

had its wettest spring since 1992. The heaviest

daily falls of the season were during April and

mid-May; the highest daily falls for spring for

between six and 14 years were recorded in the

northwest and north on April 7th. The total

number of wetdays (days with 1mm or more

rainfall) was also above normal everywhere;

between 35 and 43 wetdays were recorded in the

east and south, but more than 50 wetdays were

measured in many western areas.

Mean air temperatures for the season were above

normal for the 1961-90 period, by around one degree

at most stations. Each of the spring months was

warmer than normal. Most stations recorded close to

the normal number of ground frosts, however, with a

total of between 18 and 36 ground frosts at inland

stations. Almost all areas recorded their lowest

temperatures of the season during early March, but

no air frost was recorded during spring at stations

near the Atlantic coast.

Sunshine totals were above normal almost everywhere.

March and May were relatively sunny months, while

totals were close to normal in April. More than 15

hours of daily sunshine was measured in places at the

end of May. Mean windspeeds for the season were

above normal everywhere; they were between 7 and 12

knots generally (13 and 22km/h), the highest values

for spring for between 10 and 15 years in many places.

The highest gust of the season, 67 knots (124km/h),

was recorded at Malin Head on March 7th.

W

ETTER AND MILDER THAN

NORMAL ALMOST EVERYWHERE

The Weather of March, April and May

While it was the wettest spring since 1992 in the north of Ireland, the season was an exceptionally dry one over much of Europe, with less than half of normal rainfall in parts of Iberia and Scandinavia.

SPRING PERCENTAGE OF NORMAL RAINFALL

County/

Station

R

AINFALL(mm)

T

EMPERATURE(°C) SUNSHINE(HOURS)

N

O

.

OF DAYS WITH

:

Total Daily

mean diff. from Extremes

Mean average Highest Lowest

Rain Snow Air frost Hail Thunder Fog Gale gusts CO. CARLOW

Carlow (Oak Park) 202.7 123 15.7 24 Apr 9.3 1.0 22.3 -1.8 54 4 9 CO. CAVAN

Ballyhaise 280.6 141 14.3 25 Apr 8.9 21.6 -2.1 61 5 9 CO. CLARE

Shannon Airport 253.4 142 14.4 14 May 10.1 1.0 24.2 -0.1 5.05 104 15.0 31 May 58 2 1 3 0 6 15 CO. CORK

Cork Airport 286.6 110 23.1 9 Apr 8.7 0.4 18.5 -0.8 4.80 95 14.8 31 May 55 2 2 2 0 28 19 Roche’s Point 178.8 92 17.4 9 Apr 9.5 0.6 19.1 0.4 52 0 23

CO. DONEGAL

Malin Head 273.8 147 21.8 7 Apr 9.3 1.2 22.2 0.6 5.36 106 14.8 11 May 56 3 0 13 2 2 42 CO. DUBLIN

Dublin Airport 171.7 16.2 15 May 9.0 20.8 -3.8 5.52 108 15.2 30 May 56 1 8 2 1 8 18 Casement Aerodrome 150.7 98 10.2 15 Apr 9.2 1.1 22.8 -4.1 5.44 111 15.2 30 May 51 4 4 6 0 7 20

CO. KERRY

Valentia Observatory 352.3 126 18.3 3 Apr 10.3 0.9 21.0 1.6 4.45 91 14.1 31 May 65 0 0 8 0 3 21 CO. MAYO

Belmullet 286.5 138 25.7 7 Apr 10.0 1.2 21.9 0.3 5.40 104 14.7 11 May 61 5 0 14 2 2 41 Knock Airport 298.6 17.0 13 Apr 8.1 22.7 -2.3 4.66 14.9 11 May 67 6 4 5 0 34 21

CO. OFFALY

Birr 224.8 132 17.8 9 Apr 9.4 1.0 24.4 -1.1 5.02 107 14.5 12 May 61 2 3 0 0 1 3 CO. WESTMEATH

Mullingar 217.4 107 13.8 24 Apr 9.0 1.2 22.1 -2.2 61 8 0 CO. WEXFORD

Johnstown Castle 204.8 99 19.0 17 May 9.2 1.0 19.1 -1.4 56 2 4 % of average

Most in a day

amount date(s) % of amount date(s)Most in a day

average

%

200

150

125

100

75

50