Weather Bulletin
Total Page:16
File Type:pdf, Size:1020Kb
MONTHLY WEATHER NO. 341 BULLETIN OCTOBER 2014 A depression of 988 hPa, between Scotland and Norway, maintained an unstable, southwest to west airstream over Ireland on the 10th, bringing heavy showers to Atlantic coasts during the afternoon and evening. In the above photograph taken from Sherkin Island, Co Cork, a shower of rain over nearby Baltimore created a rainbow. (Photo courtesy of Donal Black) WARM EVERYWHERE; DRY AND SUNNY IN PARTS All monthly mean air temperatures were on or 9.6°C at Knock Airport, Co Mayo (difference above their Long-Term Average (LTA) with from LTA 0.7°C) to 12.7°C at Sherkin Island, Co differences from LTA up to 1.3°C at Dublin Cork (difference from LTA 0.7°C). The month’s (Glasnevin), Dungarvan (Carriglea), Co Wexford highest daily maximum was 19.5°C reported at and Fethard (Parsons Hill), Co Tipperary. Dublin (Glasnevin) on the 31st, its highest Monthly mean air temperatures ranged from Halloween temperature on record since 1961. Produced by Met Éireann, WIND & ELEMENTS. ......... 4 INSIDE Glasnevin Hill, Dublin 9. UPPER ATMOSPHERE........ 5 Annual subscription €80 (excluding VAT of 23%) LABORATORY............... .. 6 AGMET.......................6/7 or free online at DAILY WEATHER.............. 8 www.met.ie Data analysis based on all RAINFALL ................... 10 available data and is correct at TEMPERATURE.............. 12 time of publication. .............. 12 For more information or for data SUNSHINE ...................14 enquires e-mail: [email protected] MARINE & PRESSURE .....15 BUOY DATA - PAGE 15 GLOBAL WEATHER Data and graphics .......... 16 , Met Éireann 2 OCTOBER 2014 Both the month’s lowest air and grass minimum Wind and Elements: Monthly mean wind speeds in temperature were recorded at Castleconnell, Co southern coastal counties were the highest in six to Limerick. October’s lowest air temperature was 10 years, with mean wind speeds countrywide ranging -1.5°C reported on the 7th, while its lowest grass from 6.0 knots (11km/h) at Fermoy (Moore Park), Co minimum was -5.0°C reported on the 2nd. Cork (highest for October since 2008) to 17.1 knots (32km/h) at Mace Head, Co Galway. Gale force Monthly rainfall totals were variable with below winds were reported on 10 days, with severe gale average rainfall in parts of the Southwest, force winds recorded at Atlantic coastal locations on Midlands, West, Northwest and North and above the 5th, 20th and 21st. The month’s highest average values of above 150% in parts of the 10-minute wind speed was at Roche’s Point, Co Cork East and Southeast. Percentage of LTA values on the 5th with 48 knots (89 km/h), its highest on ranged from 57% at Newcastle West (Castle available record since 1996. The month’s highest gust Demense), Co Limerick to 189% at Kilberry, Co of 63 knots (117 km/h) was reported at both Roche’s Kildare. The wettest days were mainly the 3rd, Point on the 5th and Malin Head on the 21st, their 5th and 27th, with the month’s highest daily highest for October in ten and six years, respectively. rainfall reported on the 5th at Glenmacnass, Co Wicklow with 59.5 mm, a quarter of its monthly Nearly all stations except a few isolated stations in total of 246.4 mm (132% of its LTA). the Southwest reported ground frost in October, Available sunshine totals for October were with the highest number of days reported at Markree, variable, with percentage of LTA values ranging Co Sligo with 13. The number of days with air frost from 88% at Newport (Furnace), Co Mayo to ranged from zero at numerous locations to three at 114% at Dungarvan (Carriglea), Co Waterford. Mullingar, Co Westmeath. Hail was reported on the Daily mean sunshine ranged from 2.18 hours per 5th, 6th and 18th, with thunder and lightning day at Newport (Furnace) to 3.72 hours per day reported between the 6th and 8th and again on the at Dublin Airport, with the Dublin station also 18th. Overall, 25 days reported fog across the reporting the month’s sunniest day on the 11th country, with the highest number of days (at any one with 10.0 hours. station) reported at Dundalk (Annaskeagh), Co Louth with 18 days. Clear blue skies were present over Annascaul Lake, Co Kerry on the 12th as high pressure brought dry weather, prolonged sunny spells and light winds. (Photo courtesy of Kieran Commins) OCTOBER 2014 SOIL 3 DAILY SOIL MALIN HEAD MOISTURE DEFICITS & SOIL TEMPERATURES BELMULLET KNOCK AIRPORT BALLYHAISE MOUNTDILLON NEWPORT CASEMENT AERODROME MULLINGAR DUBLIN AIRPORT SHANNON AIRPORT GURTEEN CARLOW (OAK PARK) FERMOY (MOORE PARK) VALENTIA OBSERVATORY JOHNSTOWN CASTLE CORK AIRPORT SHERKIN ISLAND 4 WIND & ELEMENTS OCTOBER 2014 WIND (knots) ELEMENTS (no.of days) MEAN MAX. 10-MIN. MEAN MAX. GUST DAYS WITH HOURS WITH COUNTY / STATION SPEED DIR. SPEED DATE/HOUR DIR. SPEED DATE/TIME GALES GUST > 34KNOTS GUST > 34KNOTS SNOW SNOW LYING HAIL THUNDER FOG CO CARLOW OAK PARK 8.5 140° 26 5/20 150° 43 5/2100 0 4 11 CO CAVAN BALLYHAISE 6.8 150° 21 6/00 150° 39 6/0056 0 4 7 220° 21 20/23 CO CLARE SHANNON AIRPORT 9.3 140° 31 5/21 150° 43 5/1955 0 5 19 0 0 1 1 6 CO CORK FERMOY (MOORE PARK) 6.0 150° 21 17/17 140° 37 5/2136 0 3 4 290° 21 21/02 SHERKIN ISLAND 14.5 180° 38 5/20 180° 52 5/2020 2 9 68 ROCHE’S POINT 14.2 170° 48 5/21 170° 63 5/2123 4 11 75 CORK AIRPORT 10.3 150° 32 17/16 160° 56 5/2015 0 7 46 0 0 0 2 8 CO DONEGAL MALIN HEAD 16.7 300° 46 21/01 310° 63 21/0755 5 16 155 FINNER 11.0 270° 38 21/00 280° 54 21/0058 1 10 66 CO DUBLIN DUBLIN AIRPORT 11.5 290° 34 21/04 290° 47 21/ 317 1 11 50 0 0 0 0 2 CASEMENT AERODROME 11.1 160° 38 5/24 160° 53 5/2351 3 12 58 0 0 0 0 3 CO GALWAY MACE HEAD 17.1 290° 42 21/ 0 270° 54 20/2341 7 16 147 ATHENRY 7.7 220° 25 20/22 210° 38 20/2205 0 4 8 290° 25 21/01 CO KERRY VALENTIA OBSERVATORY 10.2 210° 30 20/21 230° 47 20/2159 0 9 40 CO MAYO CLAREMORRIS 8.8 220° 27 26/12 220° 43 26/1245 0 7 26 BELMULLET 14.1 190° 39 3/00 190° 50 3/0019 5 14 131 300° 50 21/0730 NEWPORT 10.6 290° 37 20/23 300° 56 21/0100 3 9 52 KNOCK AIRPORT 9.9 280° 32 21/01 300° 48 21/0103 0 11 51 0 6 CO MEATH DUNSANY (GRANGE) 8.6 260° 27 21/01 280° 41 21/0235 0 2 5 CO ROSCOMMON MOUNTDILLON 7.2 320° 26 21/13 310° 40 21/1323 0 3 8 CO TIPPERARY GURTEEN (AG COLLEGE) 9.0 270° 27 21/01 150° 40 5/2146 0 4 9 CO WESTMEATH MULLINGAR 6.5 130° 21 5/22 140° 37 6/0001 0 3 7 140° 21 6/00 250° 37 21/0129 CO WEXFORD JOHNSTOWN CASTLE 10.2 160° 31 5/23 170° 50 6/0108 0 5 27 160° 31 6/00 CARLOW (OAK PARK) < 5 BELMULLET 5 - 10 10 - 20 20 - 35 > 35 WIND SPEED IN knots PERCENTAGE FREQUENCY OF WIND DIRECTION OCTOBER 2014 UPPER ATMOSPHERE 5 Upper Atmosphere wind and temperature readings are made at Valentia Observatory twice a day by a radiosonde (a balloon with instruments attached). Shown below are daily average wind speeds and temperatures at defined pressure levels, 850, 700, 500 and 300 hPa, corresponding approximately to heights of 1.5, 3, 6 and 10 km. Monthly wind roses are also shown for each pressure level. UPPER AIR WIND SPEED AND TEMPERATURE OCTOBER 2014 300 hPa (°C) m/s SPEED TEMPERATURE 300 hPa 500 hPa (°C) m/s SPEED TEMPERATURE 500 hPa < 5 m/s 5 - 10 m/s 10 - 25 m/s 25 - 50 m/s > 50 m/s 700 hPa (°C) m/s SPEED TEMPERATURE 700 hPa 850 hPa (°C) m/s SPEED TEMPERATURE 850 hPa DAY OF MONTH 6 LABORATORY OCTOBER 2014 CHEMICAL ANALYSIS OF PRECIPITATION AND AIR SAMPLES AT VALENTIA OBSERVATORY Acid rain occurs when pollutants combine with moisture in the air to form PRECIPITATION PH AND ELECTRICAL CONDUCTIVITY ARE NOT AVAILABLE ON DRY DAYS (<0.2mm) 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 ELECTRICAL CONDUCTIVITY μScm-1 5.65 is considered acid while any value above is AIR considered alkaline. DATA SHOWN ARE INTERIM VALUES AND ARE SUBJECT TO CHANGE NO -N Conductivity measures the 2 total ion activity in the rainfall, i.e. the higher the SO2-S conductivity the greater the number of ions. SO4-S Sulphur dioxide and (μgs/m3) sulphate in air contribute to the formation of sulphuric acid; nitrate in air contributes to the formation of nitric acid. 10.8 MEAN SOIL TEMPERATURES (°C) AT 0900 UTC (+1.1) COUNTY/STATION 100 mm 200 mm 300 mm CO CARLOW CARLOW (OAK PARK) 10.4 11.2 11.4 11.1 CO.