MONTHLY WEATHER DATA AND OBS - WESTMONT 1.1W PA FEBRUARY 2011 OBSERVER NATE 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 36 22 22 .32 T 11 F,S,G 2 43 19 19 .36 0.5 9 F,G 3 26 14 18 .03 1.0 10 4 33 13 26 10 5 36 24 28 .35 0.5 9 F,S 6 31 26 27 .02 0.1 9 S 7 40 27 31 .17 0.5 9 F,S 8 31 7 7 .17 2.0 10 9 23 7 15 10 10 19 5 11 T T 10 11 33 8 26 10 12 30 22 26 .05 1.0 9 13 48 26 47 10 14 47 24 24 .17 0.2 7 S,DW 15 37 16 27 7 16 52 26 43 6 17 61 43 48 5 18 63 40 40 1 19 40 23 23 20 41 19 31 .07 0.5 21 37 18 18 1.52 10.0 T F,S 22 30 13 21 .15 1.7 11 23 38 14 27 10 24 43 24 34 .19 8 F 25 42 25 25 1.03 0.6 5 F 26 40 21 35 5 27 54 31 45 .10 4 T 28 59 25 25 .67 T T F,S,T,H,DW AVG/SUM 39.8 20.8 27.5 5.37 18.6 7.0 <--mean depth EXT 63 5 48/7 1.52 10.0 11 Date 18 10 17/8 21 21 22* *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 30.3°F (+1.8°F) Year precipitation to date: 8.45" (+1.22") Monthly precipitation departure: +1.95" Season snowfall to date: 110.6" Number of days with: Fog 8 Sleet 7 Glaze 2 Thunder 2 Hail 1 Damaging Winds 2 DETAILED OBSERVATION NOTES SOME FREEZING RAIN 1: Light freezing rain or drizzle overnight. Dense fog developing, more rain and freezing rain late this evening becoming moderate by 11:30pm. 2: Fog, rain & freezing rain overnight (.34" melted rain). Partly sunny & mild early high 43 F and becoming very windy with temperatures falling again during the PM hours and some snow showers this evening. COLDER 3: Light snow showers overnight, breezy, blustery & cold. Became partly cloudy to fair this evening. 1" of snowfall, 1.5" since yesterday evening. 4: Variable clouds overnight, partly cloudy to fair skies during the day, light winds. MORE SLEET/RAIN/HIGH WINDS 5: Overnight sleet (0.5") then periods of rain during the mid-afternoon, changing to snow showers during the evening & becoming very windy with SW winds shifting to W and gusting 40-50 mph. 6: A little bit of sleet overnight, otherwise variably cloudy with steady temperatures in the upper 20s and diminishing winds. LIGHT RAIN TO SNOW - THEN WINDY & COLD 7: Cloudy and mild with light rain developing late afternoon then mixing with and changing to wet snow around 7pm. Patchy fog developed also. 8: Periods of snow overnight tapering to snow showers by morning, 2" accumulation since midnight, skies became partly cloudy to mostly clear by evening. Windy, blustery & cold with temperatures falling all day. 9: Became cloudy & calm overnight with temperatures steady then rising slightly. Mid- level overcast all day with light variable winds & very faint sun, still cold. 10: Fair & very cold overnight low 5 F. A few light flurries this morning, otherwise becoming mostly sunny but remaining very cold high only 19 F. 11: Temperatures dropped then rose overnight when clouds moved in. Skies became partly cloudy with milder temperatures just breaking freezing. Breezy late this evening. 12: Windy overnight and all day with flurries and occasional light snow showers. MILD - SNOW MELT - VERY WINDY 13: Partly sunny, breezy & much milder today high 48 F with the warmest temperatures after sunset. Lots of snow melted. SW winds became quite strong late this evening. 14: VERY windy overnight with sustained SW to W winds 20-30 mph, gusts to 50. Mild with temperatures remaining in the 40s, before slowly and steadily dropping through the day with a period of mixed rain, sleet and snow. About 0.2" sleet/snow accumulated. Winds howled all day - this was one of the windiest days I've seen in a long time. 15: Fair & cold this morning low 16 F with little wind. Mostly sunny with occasional breezes from the west. EARLY SPRING? 16: Mostly to partly sunny and mild high 52 F. Breezy at times. Good bit of snow melt. 17: Mostly to partly sunny again and quite mild spring-like high 61. Light W winds. 18: Variable clouds, very mild and windy all day. Temperatures dropped off quickly this evening as a cold front passed through. 19: Partly cloudy, much cooler, continued windy. Temps dropped slowly through the day. WINTER RETURNS - HEAVY SNOWS 20: Cold overnight low 19 F partly sunny through mid-afternoon with breezy conditions at times. Skies became completely overcast by about 3pm, with a period of light snow around mid-evening then a few light rain showers. 0.5" wet snow and 0.07" precip. 21: Mild with periods of rain and patchy fog through the AM hours. After a brief lull, a second round of steadier and heavier precipitation commenced ~ 3:30pm. It began as sleet then quickly changed to snow, which became heavy at times and continued past midnight, with 10.0" of snow by then, and 1.52" of precipitation for the day. 22: Snow ended by ~ 3am another 1.7" since midnight, storm total since 4pm yesterday 11.7" melting down to 1.11" of water (0.96" yesterday + 0.15" overnight). Event total precip since Sunday evening 1.74". A quick but intense winter storm, followed by a partly sunny, cold but relatively calm day. 23: Partly cloudy, a bit milder, little wind. 24: Mostly cloudy, occasional light PM rain or drizzle, dense fog developing, light and variable winds. Steadier rain moved in late towards midnight (0.19"). 25: Periods of rain, heavy at times, overnight with another .82" by 7am. Rain showers with patchy fog continued through the morning, then changed to light snow showers with windy conditions from mid-day to mid-evening. The snow mostly melted when it hit the ground. 1.03" precip but only 0.6" of snow accumulated. 26: Partly cloudy during the morning, becoming overcast by mid-afternoon. Light W wind. MILD - THUNDERSTORMS - WINDY 27: Partly cloudy and mild high 54 F with occasional SW breezes, unusually nice day. Became cloudy late with some surprise lightning & thunder @ 11pm, then heavy rain. 28: Occasional showers overnight, with another thunderstorm 6:15-6:45pm and a 3rd storm from 8-9am with sharp lightning, gusty winds & pea-sized hail. Very mild during the AM followed by a rapid temperature drop. Occasional light rain showers, mixed with spits of sleet and snow, ending around sunset then partly cloudy, calmer. Some minor wind damage and flooding in the area today. winds shifted from SW to NW. MONTHLY SUMMARY February began and ended stormy, with a mild to moderate ice storm on the 1st-2nd then spring-like temperatures and thunderstorms on the 27th-28th. It was an active month and brought a potpourri of weather. Precipitation was ample, although there was considerably less snowfall than either of the first two winter months and a meager amount compared to last year's record-shattering 86.3". Much of the snows tracked west & north of our area. The notable exception was the fast-moving winter storm on the 21st-22nd, which brought 1.74" of precipitaton and 12.2" of snowfall. Two more signficant weather systems within the final week brought moderate to heavy rainfall, prompting flood warnings due to the combination of rain and snow melt. The cold front on the 28th brought high winds and numerous thunderstorms, one with small hail. Later in the day, snow and sleet fell. This was sort of typical of the entire month - stormy, variable temperatures, and very windy. There were numerous strong wind events, some causing minor damage in areas. Predictably, the lower snowfall total this month coincided with above average temps. As is often the case in February, the general temperature trend increased (warmed) through the month. The coldest readings, nothing extreme like in late January, occurred during the 2nd week, with several single digit lows. The 10th had the coldest high AND low temperatures of the month, a high of only 19 and a low of 5. The mildest temperatures followed about a week later, with highs reaching the 60s on the 17th-18th and lows in the 40s. After 25 sub-freezing max temperatures in December and 24 more in January, only 6 days failed to climb above freezing in February, thus a frequent freeze/thaw pattern often seen in later February and March. The month finished mild with highs in the upper 50s ahead of the last in a series of strong, fast-moving fronts on the 27th-28th. Winter did indeed ease up, and February was spring-like at times, but with a lot of temperature swings and several days with snowfall, one day (21st) seeing heavy snows. This storm was one of many highlights of an active, changeable weather month. All 6 special observations were seen in February, with fog, sleet and high winds a common theme.