MONTHLY WEATHER DATA AND OBS - LAVALE MD MAY 2010 OBSERVER SCOTT LOHR DATA COMPILED AND PUBLISHED BY NATE MULLINS Special Observations: F=fog, T=thunder, H=hail, S=sleet, G=glaze, DW=damaging winds Observation time for this station is midnight. Temperature, °F Precipitation, In. Liquid Solid 7am DAY 24-hour Rain Snow/ Snow Special WEATHER Date Max Min Equiv Ice Depth Obs. SUMMARY 1 92 56 Partly cloudy, RECORD HEAT 2 74 67 1.12 Cloudy, cooler, showers heavy at times 3 77 64 .50 Showers overnight, cloudy AM, PM clearing, gusty W winds 4 74 52 Partly cloudy, breezy 5 80 48 Sunny, warm 6 72 52 .03 Early AM shower, clearing, breezy 7 77 46 Partly cloudy, high clouds 8 74 41 .13 Early AM rain, very windy, falling temps, NW gusts to 40 mph 9 53 37 Partly cloudy, cool, breezes from N 10 59 33 Cold AM with frost, mostly clear/sunny 11 45 38 .80 F Very cool, rain heavy at times 12 68 45 .10 F Mostly cloudy, few PM light showers 13 55 50 .16 F Mostly cloudy, cool, light rain/drizzle 14 83 52 .02 Partly cloudy, much warmer, strong SW breezes, brief PM shower 15 72 56 Mostly sunny, breezy, pleasant 16 72 55 Variable clouds, light N winds 17 55 52 1.27 F Steady cool rain all day 18 54 50 .08 F Mostly cloudy, occasional brief showers 19 60 50 .02 F Mostly cloudy, brief AM showers 20 82 48 Partly cloudy to fair, much warmer 21 81 53 Partly sunny 22 66 58 .76 F Increasing clouds, PM rain showers, heavy at times 23 76 61 T F Variably cloudy 24 69 61 .07 Mostly cloudy, a few showers 25 79 59 Mostly to partly cloudy 26 86 59 Mostly to partly cloudy, very warm 27 88 62 Partly to mostly sunny, very warm 28 85 64 .80 T,H,DW Mostly cloudy, SEVERE PM t-storm - flooding, hail, damaging winds 29 85 64 F AM fog, mostly cloudy 30 87 59 Partly sunny, very warm, low humidity 31 86 62 .04 Partly sunny, few brief PM showers, light SSW breezes AVG/SUM 73.1 53.4 5.90 0.0 - EXT 92 33 1.32 - - Date 1 10 2 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 63.1 °F (+2.4°F) Year precipitation to date: 17.96" (+0.66") Monthly precipitation departure: 5.90" vs. 4.10" (+1.70") Season snowfall to date: 78.3" (+37.5") Number of days with: Fog 9 Thunder 1 Hail 1 Damaging Winds 1 NOTES/SIGNIFICANT EVENTS 1: An unusually hot start to May with a RECORD HIGH of 92 F, beating 2007's previous record of 89. 2-3: Heavy rains from a slow-moving system approaching from the southwest. 1.62" of rainfall in 24 hours ending mid-morning on the 3rd. This is more rain than what fell in the entire month of April (1.29"). The low of 67 on the 2nd set a daily record high min temperature, and the 1.12" of rainfall also set a daily record. 8: Strong cold front passed through early this morning, with temperatures falling all day and very windy with NW winds gusting to 40 mph. Frostburg State University clocked the wind at 49 mph. 9: Another cool, breezy, blustery day. Winds gusted to 41 mph at Frostburg. Some snow showers in the mountains to our north & west early this morning, including at my Westmont, PA station. 10: A chilly, frosty morning low 33 F. However nowhere near the record of 24 in 1980, which was the all-time record low for May. 11: Very cool with steady cold rains, heavy at times during the PM hours. High only 45 F, which ties May 6-7, 1958, for the coolest max temperature ever in May. Sleet was reported in Frostburg, and I also observed sleet WITH thunder at my Westmont 1W station near Johnstown, PA. 12-13: Continued cool with light rain showers & drizzle. Low clouds & mountain fog. 14: Much warmer and very humid. Brief PM shower as another front passed through. Severe storms passed north of the area. 17: Another chilly, steady all-day rain. 1.27" set a new daily rainfall record. More light rain showers and cool temperatures on the 18th-19th (storm total 1.37"). 20-21: Fair and much warmer with highs in the low 80s. 22: Occasional showers, were heavy at times this evening around sunset. Rain became very intense just to our east in downtown Cumberland, where COOP observer Tim Thomas recorded 1.60" of rain, almost all within an hour. A much more modest 0.76" of rain fell at this station. 26-27: Partial sunshine and very warm. 28: Mostly cloudy, warm & humid. The following was posted by Dr. Greg Latta, a COOP and fellow ACON observer, on his website regarding the severe thunderstorm that ravaged the northwest part of Allegany County for 1-2 hours beginning at 2pm: "The most severe isolated thunderstorm I have observed in Frostburg occurred between 2 PM and 3 PM. It had quarter sized hail and winds that stripped the leaves from the trees and broke small branches. Most of today's 2.21" of precipitation came in form of thunderstorms." The storm hammered the Frostburg and Mt. Savage areas with large hail from penny to golf ball size, damaging winds and torrential rains of 2+" causing flash floods in both towns. The storm then slowly drifted SE towards us and weakened a good bit but still produced notable hail, intense frequent lightning, strong winds and heavy rains over LaVale and especially Cumberland. 0.80" rain fell at this station from 2:30-3:30pm. 29-31: Continued warm. Severe storm watch again on the 31st but never materialized locally. MONTHLY SUMMARY For the 3rd consecutive year, May had above normal precipitation. The rains were welcome after a very dry April. Several moderate to heavy rain events occurred, and these events were well spread out through the month. The heaviest event was early in the month (2nd-3rd, 1.62"), while the most notable event was a severe thunderstorm that ravaged the NW portion of the county on the afternoon of the 28th, causing flash flooding, wind damage and large hail up to the size of golf balls. The Frostburg-Mt. Savage areas were hardest hit, with 2 to 3 inches of rain. Temperatures were above normal for the 3rd consecutive month. Max temperatures were all over the place, ranging from a record 92 on the 1st to a chilly 45 on the 11th, which tied for the all-time lowest max temperature ever in May. Max temperatures fluctuated quite a bit, finally leveling off to summer-like readings during the final week. With all of that said, max temperatures averaged exactly normal. However, min temperatures were a full 5 degrees above normal, and accounted entirely for the month's positive temperature anomaly. The coldest readings occurred during the 2nd week, with 30s on the 9th, 10th and 11th. A significant frost was observed on the 10th, with freezing temperatures at many nearby locations. After the 2nd week, lows were generally in the 50s to low 60s. May's relative warmth completed a very warm spring, in fact tying 1991 for the warmest spring season ever on record! May could best be summed up as an active month, with many frontal passages, above normal temps and precip, and was a windy and changeable month, with some substantial temperature fluctuations. Some very late season snow/sleet occurred during the abnormally chilly 2nd week in the mountains. Additional notes/records 1: RECORD HIGH 92 F. Breaks the record of 89 set in 2007. 2: Record high min temperature of 67 F. Shatters prior record of 58 in 2007. 2: Daily record rainfall 1.12". Breaks old record of 0.87" in 1989. 3: Record high min temperature of 64 F. Breaks old record of 59 in 1954. 11: RECORD LOW MAX TEMPERATURE 45 F breaks old daily record of 51 in 1989, and TIES MAY 6-7, 1958 for the ALL-TIME COOLEST max temperature ever in the month of May! 17: Daily record rainfall 1.27". Breaks old record of 0.96" in 1970. 18: Record low max 54 F tied. This mark was previously set in 2002 and again in 2003. 27: High 88 F, misses record of 89 in 1991 by 1 degree. 28: Worst hail storm to hit Allegany Co. since golf-ball sized hail hit Cumberland Jun 13, 2007. One of the most notable severe thunderstorms ever in the NW part of the county. May 2010 had the 3rd warmest mean min temperature on record for May with 53.4 F. Spring 2010 tied the Spring of 1991 for the WARMEST SPRING ON RECORD with a mean temperature of 55.4 F. This was a very dramatic turnaround after the SNOWIEST winter ever (78.0") in 2009-2010!