MONTHLY WEATHER DATA AND OBS - WESTMONT 1.1W PA JANUARY 2012 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 47 30 30 .22 T F 2 30 20 20 .12 2.3 T S 3 20 5 5 .06 1.2 3 4 30 4 26 3 5 38 26 38 2 6 54 38 50 T 7 50 33 33 8 35 26 27 9 40 24 35 10 41 30 30 11 40 25 37 .82 F 12 44 36 37 .37 F 13 37 14 16 .31 3.5 2 14 20 14 15 .06 3.7 4 15 23 12 14 5 16 43 11 43 .25 0.1 4 S,G 17 55 35 35 .33 T F,DW 18 35 15 15 .02 0.3 T 19 31 11 20 .17 2.5 T 20 22 9 20 .10 0.8 3 S 21 27 17 17 .68 2.7 4 S 22 30 13 30 4 23 48 29 41 .20 4 24 41 30 30 2 25 37 27 32 T 1 26 40 31 40 .72 1 F 27 51 30 30 .58 0.2 T F,S,DW 28 39 27 27 .03 T T S 29 38 25 25 .03 0.5 30 48 19 48 1 31 57 45 45 T AVG/SUM 38.4 22.9 29.4 5.07 17.8 1.4 (avg) EXT 57 4 50/5 0.82 3.7 5 Date 31 4 3/6 11 14 15 *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 30.7°F (+4.8°F) Year precipitation to date: 5.07" (+1.26") Season snowfall to date: 37.2" Number of days with: Fog 6 Sleet 6 Glaze 1 Damaging Winds 2 DETAILED OBSERVATION NOTES STRONG COLD FRONT 1: Mostly cloudy with intermittent brief rain showers all day and patchy fog, mild temps also. Strong west winds developed by late afternoon, some snow flurries late this evening. 2: Flurries overnight, then intermittent snow showers, very windy & blustery with temps continuing to fall through the 20s. A much more typical winter day around here, 2.3" of wind-driven snow. 3: Light snow overnight, another 1.0" by 7am. A very chilly blustery day with temps falling through the teens but very little additional snow as heavy lake-effect snow bands set up just north and just south of here and didn't move all day. A very cold evening with wind chills below zero. 4: Very cold overnight low 4 F with clouds slowly moving in. Variable clouds, breezy and blustery with strong west winds again and a high of 30. MUCH MILDER 5: Clouds moved in overnight with slowly rising temperatures. Clouds dissipated by noon and it was a mostly sunny day with a spectacular sunset. Became windy again this evening this time bringing in warmer air as temperatures continued to slowly rise all evening to 38 by midnight. 6: Temperatures continued to slowly rise overnight with strong SW winds gusting 40+ mph. Mostly cloudy early then clearing and mild with a high of 54 F. Continued windy all day. 7: Partly cloudy and continued mild and windy, though this time with slowly falling temperatures. 8: Variably cloudy & breezy @ times overnight with slowly rising temps again. Partly to mostly sunny with seasonably cold temps. 9: Partly to mostly sunny again with passing clouds, moderate NW breezes and somewhat mild temps. 10: Partly cloudy with strong breezes from the west, similar temps to yesterday. RAIN 11: Fair and frosty overnight, milder and becoming cloudy with a period of early afternoon rain, the rain became steadier and heavier in the evening .82" by midnight with fog forming also. 12: Rain ended overnight. Occasional drizzle or light rain with fog and steady temps around 40. Some heavier rain late this evening with another .37" falling by midnight. SNOW - WIND - COLDER 13: Very windy overnight with rain quickly changing to snow and an abrupt drop in temperatures. A much more winter-like day with light snow, temperatures in the teens, strong west winds and a lot of blowing & drifting snow 3.5" fell today (.31" of water). 14: More snow overnight 2.5" additional fell by 7am with light snow still falling, winds diminished overnight but still breezy & blustery with periods of light snow. 3.7" fell with skies clearing in the evening. The 3.7" snow only melted down to .06" of water - an unusually "dry" snow. 15: Clear & chilly overnight low 12 F. Sunny but still chilly with a high of only 23. VARIABLE & WINDY 16: Clear and chilly early then becoming cloudy, milder with an intermittent mix of freezing rain and sleet, changing to light rain showers. 0.25" of precip, 0.1" of sleet, and a small layer of black ice formed. Strong SW wind gusts late this evening brought warmer air as the temperature spiked up to 43 F by midnight. A very changeable and interesting March-like weather day. 17: Occasional rain showers (0.33"). A wildly variable and unusually mild day with variable clouds and very strong SW winds gusting to 45 mph. Winds howled all evening as temperatures finally began to drop off. This was one of the top 5 windiest days I've seen in the past 5 years or so. 18: Windy overnight with temperatures falling from the mid 30s to low 20s and occasional light snow showers, mostly in the AM, only 0.3" snow, cold but clearer, calmer evening with a late low 15. 19: Clear & chilly overnight, increasing AM clouds, light to occasionally moderate snow developed this evening, 2.5" by midnight with snow tapering off. 20: Partly cloudy AM becoming cloudy PM with light NW winds and a late mix of snow and sleet with 0.8" accumulation of snow and ice. 21: A mix of snow and sleet continued overnight. 3.5" (2.7" since midnight) total by 9am with the precip tapering off, remaining cold, low clouds persisted until after sunset, then clearing. 22: Fair early overnight then cloudy all day with SSE breezes and temperatures steady in the upper 20s to around 30. 23: Mild with a period of morning rain and gusty SE winds shifting to W. Variable clouds and windy this evening. 24: Mostly cloudy and windy with winds slowly dimishing and temperatures slowly falling through the 30s. 25: Mostly cloudy again with light W winds and temperatures steady most of day in the mid 30s. A few spits of drizzle late this evening. 26: Some drizzle overnight then a steady light to moderate rain commencing this morning around 9am with dense fog developing. Rain tapered off around 9pm with a total of .72" falling. 27: Warming temperatures overnight with occasional showers from 4am to 9am and a couple of brief downpours, most notably at 8:30am when the front moved through and strong W winds gusted 40+ mph through the AM, gradually diminishing in the PM. Light showers of rain/sleet/snow mixed with 0.2" of sleet/snow and .58" of precipitation as temperatures dropped below freezing late. 28: Clear early overnight becoming cloudy again by dawn. Several brief PM showers of light rain, sleet and snow mixed then becoming very windy again with clearing by sunset, falling temps. 29: Fair skies most of the day then becoming variably cloudy with a few snow showers this evening. Again gusty W winds developed. Falling temperatures overnight. 30: Chilly overnight and morning with partly cloudy AM skies, mostly cloudy PM. Became very windy again this evening with SW winds blowing in some unusually mild air. Temp rose to 48 by obs. 31: Clear skies but very windy and mild overnight with temperatures in the 40s. SW winds gusted to ~40 mph again. Breezy, mild, partly cloudy. High reached 57 F. A few evening sprinkles. MONTHLY SUMMARY 2012 was off to a mild start in January, which was very characteristic of the previous two months: Above normal temperatures and precipitation, but with little snow. Winter only made a few brief appearances, as there were only 9 days (compared to 24 in Jan. 2011) that remained below freezing. Snowfalls were light, and what snow we had didn't stay on the ground for long. Less than half the month (15 days) had measurable snow on the ground at 7am. Temperatures varied quite a bit, due to countless fronts - most of them weak - moving across the area. On average, January 2012 was nearly 10 degrees warmer than last January. It was the 3rd consecutive month and the 9th of the past 10 with above normal temperatures. 5 days were in the 50s - in contrast to the previous 3 January's, none of which had any days over 47. A high of 57 on the 31st was the warmest January reading since Jan. 8, 2008, more than four years ago, when the high reached 62. Precipitation fell frequently, in fact almost constantly, from the 11th on - mostly in the form of rain. On the 11th-12th, 1.19" of rain fell. This was followed by the month's heaviest snow event, with 7.2" falling the 13th-14th. Precipitation fell every day from the 16th-21st. The second major precipitation event was a sleet and snow storm - mostly sleet - on the 20th-21st. 3.5" of snow and ice fell, accounting for .78" of precipitation. The final major precipitation event was the 26th- 27th, when 1.30" of rain fell. Temperatures didn't drop much after this system - in fact warming to a balmy 57 on the 31st with a low of 45. Another highlight of January was frequent strong wind events. The second half of the month was exceptionally windy, with many days seeing gusts of 40+ mph, on a couple of occasions causing minor tree damage. In contrast to last January's brutal NW winds off of Lake Erie (which led to significant lake effect snows), most of these winds were from the W or SW, another factor in the mild temperatures and lack of significant snow.