MONTHLY WEATHER DATA AND OBS - WESTMONT 1.1W PA DECEMBER 2010 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 55 25 25 .94 1.7 F,S 2 28 24 26 .16 2.5 3 3 30 24 24 .03 0.4 3 4 29 22 25 T 0.1 3 5 25 21 21 .17 3.5 4 6 23 17 17 .16 5.5 6 7 20 15 15 .14 5.5 9 8 21 16 19 .05 2.3 11 9 23 12 12 .04 1.3 10 10 32 12 31 .03 0.5 9 11 44 23 32 8 12 36 24 24 .50 T 5 13 24 11 11 .23 4.8 4 14 14 9 9 .17 3.5 8 15 19 9 13 .07 2.5 8 16 23 9 13 T 0.3 8 17 26 12 21 T T 8 18 26 13 13 .01 0.3 7 19 25 13 19 .02 0.6 6 20 22 18 20 .06 1.5 7 F 21 28 19 24 .01 0.2 7 22 31 21 22 .02 0.2 6 S 23 27 21 22 .12 1.5 7 S 24 25 20 22 .01 0.2 7 25 27 21 22 .05 1.7 8 26 22 15 15 T 0.1 8 27 21 12 19 .01 0.4 8 DW 28 27 15 24 T 0.2 8 29 34 23 23 7 30 35 18 32 .02 T 7 F,G 31 48 30 44 6 AVG/SUM 28.1 17.5 21.3 3.02 41.3 6.6 <<--mean depth EXT 55 9 44/9 0.94 5.5 11 Date 1 16* 31/14 1 7* 8 *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 22.8°F (-7.5°F) Year precipitation to date: 56.44" (+8.75") (final total for 2010) Monthly precipitation departure: -0.31" Season snowfall to date: 42.9" Number of days with: Fog 3 Sleet 3 Glaze 1 Damaging Winds 1 DETAILED OBSERVATION NOTES HEAVY RAINS END AS SLEET AND SNOW - WINDY & TURNING COLDER 1: Periods of rain heavy at times overnight another .65" fell by 7am. Temperatures were very mild early then quickly dropped off and changed precip to a sleet/snow mix around 7am, eventually to all snow, which was mostly light. Windy & blustery in the PM hours. There were a lot of wrecks due to the icy conditions, and some parts of Clearfield Co. to our north had 4+ inches of rain in about 24 hours - a good bit of flooding was reported througout much of the state of PA. 2: Breezy, cold & blustery with light snow overnight and intermittently through the day. Another 2.5" fell, 4.2" the past 2 days. High only 28. Winter seems to have arrived on cue! 3: Very fine light snow overnight, flurries and occasional light snow showers with mostly cloudy skies through the day and continued cold/blustery conditions. 4: Mostly cloudy & cold overnight with occasional flurries. Continued mostly cloudy with flurries resuming this evening and W winds picking up slightly. PERSISTENT SNOW, COLD & WIND 5: Becoming windy overnight with gusty W to NW winds and light snow developing 1.5" by 7am. Light snow continued through the evening with a bit of blowing and drifting 3.5" total snowfall. 6: Steady light snow, occasionally moderate, with a lot of blowing & drifting. 2.5" by 7am, 4.0" by 4pm, 5.5" by midnight. Snow was very light & fluffy and only amounted to .16" of precip. Winds howled all day, frequently gusting 30-35 mph, making it very blustery with a high of only 23 F. 7: More snow & blowing snow overnight. Another 3" by 7am. Storm total now 12.0". Light snow all day and evening, breezy & blustery. 5.5" of new snow for the day. 8: Light snow overnight, breezy, cold but with temperatures rising slightly. 1.5" more snow by 7am. Occasional snow showers throughout the day, blustery. Total snow today 2.3". 9: Light snow slowly tapered off overnight along with diminishing winds. Another 1.0" by 7am. A few more light snow showers through mid-afternoon, then partial clearing, cold evening. 10: Becoming overcast overnight with rising temperatures. A period of light snow around mid-day, light SW winds, 0.5" of snow accumulated. BRIEF FAIR WEATHER 11: Mostly cloudy early, gradually becoming fair and milder today with occasional S breezes. Became cloudy again after sunset. First day this month without any snow! COLD RAIN 12: Cloudy with cold moderate rains commencing around 9am, tapering to light rain & drizzle by noon. A few flurries and becoming breezy with falling temps this evening and gusty SW to W winds. WINTER RETURNS - SNOWY, WINDY & VERY COLD 13: Cold, windy & blustery with snow showers developing overnight. Periods of snow and snow showers with gusty W to NW winds. Temperatures slowly fell all day. Heavier snow between 6-9pm with 2" in that period. Light snow, strong winds & blowing snow all evening with 4.8" snow for the day. 14: Light snow, strong W winds & blowing snow overnight with another 2" by 7am. A lull in the storm during the early PM hours, then intermittent light snow resumed around sunset. Very cold high only 14, quite blustery. 3.5" more snow fell today. 15: Continued cold, windy & blustery overnight with light snow 1.2" by 7am. Steady light snow and blowing snow, continued cold, snow tapered to flurries by late afternoon. Total snow today 2.5" and storm total snow since Monday morning (13th) 10.8". 16: Very light snow ended overnight. Cloudy & cold this morning low 9 F. Cloudy and still cold but felt much warmer due to the lack of wind. A large snow system this time passed south of here. 17: Mostly cloudy overnight and this morning. Partly cloudy AM, mostly cloudy PM with snow flurries but no accumulation. Light SW to W winds. 18: Very fine light snow or flurries overnight. Mostly cloudy AM, partly cloudy PM. Light W winds. 19: Continued cold and blustery with snow flurries at times, light N winds occasionally gusty. Snow remained light but became steadier late this evening. Skies were mostly cloudy all day. 20: Intermittent very fine light snow overnight w/ low clouds & light fog developing. Light snow resumed from about 8am - noon before tapering back to flurries, 1.5" of snow today. 21: Very fine light snow overnight, flurries this morning, then partly cloudy, light N winds. 22: Variably cloudy, mild early but continued windy & blustery with light snow showers developing during the evening and mixing with very fine ice pellets (sleet). 23: Overcast virtually all day with periods of light snow and sleet, tapering to flurries by late afternoon. Continued cold, very windy & blustery. 1.5" of snow & ice. NW winds gusted 30+. 24: Continued cloudy & cold. Light AM snow showers, PM flurries, breezy & blustery. MORE SNOW FOR CHRISTMAS 25: Light snow commenced before dawn and tapered to intermittent flurries by mid-morning 1.5" by 10 am. Light NW winds. A few PM flurries, not much more accumulation. 26: Partly cloudy early, the overcast, windy & blustery with light snow that either blew away or sublimated as it landed, as there was surprisingly almost no accumulation. 27: Flurries overnight, cold & very windy. Became party sunny by mid-morning, then cloudy with more flurries and light snow showers by mid-afternoon. N to NW winds howled, gusting 40-50 mph. 28: Another cold blustery day with AM flurries and windy conditions, skies partially cleared by late morning, strong W to NW breezes continued into the evening. WARMING TREND 29: Mostly cloudy this morning, becoming partly to mostly sunny during the PM hours. Milder high 34 the first day in the past 17 to break freezing, only the 4th this month. Lighter winds today. 30: Chilly this morning with a period of light freezing rain around midday. Temperatures rose above freezing during the mid-afternoon. Cloudy all day, becoming clear with light fog after sunset. 31: Clear early becoming cloudy and milder. Overcast with slowly warming temps, then becoming clear by late afternoon. Light fog developed again this evening. MONTHLY SUMMARY December began and ended mild, but everything in between was anything but. This was a very cold, snowy and windy December, and quickly brought back memories of the brutal 2009-2010 winter. The streak of 9 consecutive months, 3 full seasons. with above average temperatures came to an abrupt end, as December was consistently cold, some 7.5°F below normal, the coldest month of 2010 with respect to normal. Daytime highs were particularly cold, due to nearly continuous cloud cover and precipitation - mostly snow. Max temperatures failed to rise above freezing a remarkable 25 of 31 days. All 31 days of December had sub-freezing lows, another remarkable stat. In all 3 2010 winter months, spanning portions of separate winter seasons, an amazing 89 of 90 days reached below freez- ing. Temperatures themselves were never extreme, as the low was a modest 9 F, but strong winds and blowing snow made weather conditions brutal at times. There were few mild readings, with December's high of 55 set very early on the 1st, then winter flat-out kicked our butts. December racked up 41.3 inches of snow, which seemed to fall constantly through the month. Despite the snow surplus, precipitation was slightly below average, and half of it fell from two rain events the first half of the month, with nearly an inch (.94") on the 1st and 2.61" in a 30-hour period Nov 30 - Dec 1, which prompted flood advisories and warnings in the area. After this heavy rain event, which ended as sleet and snow, the weather pattern was fairly quiet most of the time. However, a steady west to northwest wind off the Great Lakes brought relentless, orographically enhanced light to moderate snows. The heaviest event was early, with 14.5" falling from the 5th-7th. Another 10.8" fell from the 13th-15th. Both lake-effect snow and wind events followed strong cold fronts. The 2nd system brought wind chills as low as -13 F. At least 6" of snow lay on the ground nearly all month, and we had a white Christmas, which has been surprisingly rare (global warming?) as of late. A potent late-month Nor' Easter dumped tremendous snows in the New York City area and extreme eastern PA. We experienced some wild winds and cold temperatures, but little snow this time. The month ended much like it did - mild, with a high of 48 on New Year's Eve.