MONTHLY WEATHER DATA AND OBS - WESTMONT 1.1W PA APRIL 2010 OBSERVERS NATE AND STEVE MULLINS Special Observations: F=fog, T=thunder, H=hail, S=sleet, G=glaze, DW=damaging winds Observation time for this station is midnight (Eastern US). Temperature, °F Precipitation, In. Liquid Solid 7am 24-hour At Rain Snow/ Snow Date Max Min Obs Equiv Ice Depth Special Obs. 1 80 38 61 2 84 48 61 3 80 53 57 4 67 48 53 5 77 44 61 T 6 83 57 68 .01 T 7 83 61 61 8 78 43 43 .17 T 9 43 33 33 .01 T 10 58 31 47 11 69 44 51 12 68 37 47 13 47 35 35 .24 14 60 29 45 F 15 75 36 62 16 77 50 50 .65 T,H,DW 17 51 34 34 .01 T S 18 41 31 37 .03 T 19 60 33 45 20 66 32 49 21 69 38 50 22 67 36 49 23 68 38 50 24 57 44 47 .07 25 72 46 50 .58 F,T 26 57 45 45 .86 F 27 51 35 35 28 52 30 40 29 64 38 48 30 79 41 62 AVG/SUM 66.1 40.3 49.2 2.63 T 0 EXT 84 29 68/33 0.86 T - Date 2 14 6/9 26 18* - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 53.2 F (+4.8 F) Year precipitation to date: 16.61" (+1.70") Monthly precipitation departure: 2.63" vs. 3.81" = (-1.18") Season snowfall to date: 163.7" Number of days with: Fog 3 Sleet 1 Thunder 4 Hail 1 Damaging Winds 1 DETAILED OBSERVATION NOTES RECORD WARMTH 1: A somewhat chilly morning low of 38 F but a spectacular rebound to a record high of 80 F, one of the earliest ever 80-degree readings here in Westmont. 100% sun and moderate winds at times from the SW. 2: Very warm again with a rapid warm-up into the 80s by noon! Partly to mostly sunny with mostly high clouds, SW breezes and another record high of 84 - unusually warm for this early in the warm season! 3: Mild overnight low 53 F, another unusually warm day with variable high cloud cover, increasing south breezes. High 80 F. Mild & breezy this evening - tree frogs heard! I have never heard them this early in the season. Also it's unusual to have 3 consecutive 80+ days at this location so early! 4: A bit cooler today with diminishing winds from the NW to W but fair skies (high thin overcast this afternoon) and still relatively mild high 67 F. 5: Another mostly sunny, warm day, after an early sprinkle, strong breezes (25-30 mph gusts) from SW shifting to W. High 77 F. 6: A brief shower around 5am with several rumbles of thunder. Most of the storms went to our north. Became partly sunny & windy this morning, SW wind gusts 30+ mph. Fair, very warm with a summer-like evening with a high of 83 at 4pm and only falling slowly as the evening wore on. 7: Very mild overnight low of 67 F. Another warm, windy & fair day with high clouds slowly thickening in the afternoon. High 83 F once again. SW winds gusted 20-30 mph through mid-afternoon. 8: Another mild day with a high of 78 F early this afternoon then a brief gusty thunderstorm at 4pm, a quick downpour followed by lighter rains .17" fell, temperatures fell rapidly following the storm. 9: A chilly day with a high of 43 set at midnight and temperatures only in the mid-upper 30s during the day. Breezy & blustery with overcast skies & snow flurries, which melted and didn't accumulate. 10: A cool start with a low of 31 F then a pleasant, sunny day with gusty NW winds and a high of 58. 11: A mild, mostly sunny & pleasant day with strong SW breezes at times and a comfortable high of 69. 12: Mostly sunny and pleasant, breezy at times, increase in high clouds to mostly overcast by sunset. 13: Overcast, a period of light-moderate rain commenced around 7am, ended around 11am. Cloudy and cool with occasional breezes from the east, skies quickly cleared from the north around 6pm. 14: Chilly low 29 F with some frost and dense fog early. Became sunny & pleasant high 60 F with light- moderate E breezes shifting to SW and scattered high clouds (cirrus), yielding another nice sunset. 15: Cool overnight with a low of 36 then a mild day with fair skies & light W winds high 75 F. A mild evening with some increase in clouds, still 62 F at midnight. SEVERE THUNDERSTORM - DAMAGING WINDS 16: Mild overnight low 58 F with variable clouds. Partly cloudy, breezy & warm high 77 F. A brief but wild thunderstorm ripped through at 4:40pm with vicious wind gusts, brief torrential downpours, pea-sized hail and very close, sharp lightning. A 30-foot tall unleaved oak crashed down on the fence out back, damaging that, and branches littered the yard. Winds were clocked at 62 mph at the Johnstown airport, and an incredible 79 mph was recorded to our east at Altoona! Wind damage was widespread with many power outages. Temps dropped from 73 to 54 (19 F) in only 20 minutes from 4:40 to 5pm. Windy with two more heavy showers this evening, one with a peak rain rate of 5.94"/hr at 8:45pm. Total .65" rainfall by 9pm. Daily low of 50 was set at midnight. 17: Cloudy, windy & much colder with blustery conditions and W to NW winds 20-30 mph at times. A few spits of snow mixed with ice pellets (sleet) with temps only in the mid-upper 30s during the day. 18: Continued mostly cloudy & chilly high only 41 F with breezes from the WNW, occasional snow flurries and a brief rain shower around 5:30pm (.03"). 19: Clearing skies overnight with diminishing winds, shifting to SW early then back to the WNW, sunny & clear with low humidity and a much milder high of 60 F. 20: Clear overnight with a light frost & freeze, low 32. Good rebound to a comfortable high of 66 F, light SW winds, slow increase in high cloud cover, becoming only about 20% transparent by sunset. 21: Mostly clear, cool overnight, mild & partly to mostly sunny today with light west breezes, high 69. 22: Fair and cool overnight low 36 F. Partly to variably cloudy skies with occasional breezes and a few sprinkles during the mid-late afternoon, only a trace of rain. High 67 F. Fair after sunset. 23: Sunny/fair skies with light W winds and variable PM high cloudiness, and similar temps to yesterday. SHOWERS & STORMS 24: Mostly cloudy, a period of light mid-day rain, with more occasional light rain and drizzle late this evening .07" fell. 25: Occasional rain and showers overnight another .23" fell. Became partly cloudy by late morning with mild temperatures and moderate breezes from the S. Strong to severe thunderstorms blew up overhead and just east of here at 3:45pm with very heavy rain over the south/east parts of town but only .05" here. A second storm dropped a quick .22" at 5pm with a peak rainfall rate of 4.57"/hr. Areas to our northeast were hardest hit with quarter-sized hail reported and well over an inch of rain in some places. A few more showers with patchy fog through the evening .58" total fell for the day. 26: Intermittent rain overnight and through about mid-morning another .46" fell by 8:30 am. More rain showers of varying intensity through the PM hours, ending by 11pm .86" total rain for the day. 27: Skies cleared overnight - partly to mostly sunny skies, breezes from NW and cooler temperatures but still a nice day. 28: Cool overnight with a freeze but no major frost as expected due to winds. Low 30 F. Fair to partly cloudy skies this morning & breezy, mostly sunny and somewhat cool with breezes from WNW. 29: Not as cold as expected overnight, low 38 F. Sunny, seasonably mild & pleasant with SW breezes and a high of 64 F. Increasing clouds during the evening, but fair again by late. 30: Cool early low 41 F with a rapid warm-up during the morning with strong SW breezes. Warm high 79 F with clear blue skies and low humidity. Fair, mild & calm this evening. MONTHLY SUMMARY April was highlighted by unseasonably warm temperature and record heat the first week. 5 of the first 7 days were in the 80s, and the high of 84 on the 2nd was a record, as were the highs AND lows on the 6th and 7th. Interestingly, the first week was the warmest, and the overall temperature trend, while consisting of many ups and downs, was somewhat backwards for April, with the warmest temperatures at the beginning of the month and cooler temperatures later on. Precipitation was below average - while there were about an average number of frontal passages, these fronts moved in a zonal fashion (west-east) and did not tap much Gulf or Atlantic moisture. The first half of the month was particularly dry, with the most significant frontal passage (and its associated precipitation) on the 8th, which brought an end to the record warmth and ushered in snow flurries and unseasonably cold temperatures on the 9th. This system also produced some severe weather throughout parts of the state, but none in the immediate area. A weaker system produced light rains and another brief bout of cool temperatures on the 13th. The following morning (14th) had the month's coldest temperature of 29, a modest extreme low for April. Perhaps the most notable frontal passage, and without question one of the highlights of the month, was the widespread severe weather outbreak along a cold front on the afternoon and evening of the 16th. A squall line raced eastward across the state, producing straight-line winds over 60 mph, and at some locations, over hurricane force! Widespread wind damage hit the area, with signficant tree damage in the backyard. Pea-sized hail and brief torrential downpours also occurred. Power outages were wide- spread, and some areas didn't see power for nearly a week. Temperatures behind this potent cold front dropped into the 30s, with a high of only 41 and snow mixed with rain showers on the 18th. After about a week of fair and seasonable weather, another system, the most signficant precipiation event (which accounted for nearly 2/3 of the month's rainfall), passed through on the 25th-26th. Thunderstorms on the 25th were severe just northeast of this station, where quarter-sized hail and very heavy rain was reported. The 26th was a relatively cool, showery day, with nearly an inch of rain (0.86") falling. The 1.51" storm total from the 24th-26th saved us from a near-record dry month. Cool temperatures followed this system as well, with a low of 30 on the 28th, but the mercury quickly rebounded to a warm 79 on the final day (30th). In summary, April 2010 was dry (particularly during the first half) and very mild compared to average, most likely in the top 5 warmest Aprils in the past half-century.