MONTHLY WEATHER DATA AND OBS - LAVALE MD DECEMBER 2009 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 53 35 Mostly sunny, mild 2 46 31 .40 Mostly cloudy, PM rain heavy at times 3 48 40 .39 Pre-dawn downpour w/ SW wind gusts to 30 mph, partly cloudy 4 40 34 Mostly cloudy 5 34 29 .44 5.0 Steady snow all day 6 34 23 5 Partly to mostly cloudy 7 34 21 3 Mostly cloudy 8 36 32 .50 3.0 2 S Mostly cloudy. Heavy snow began 8pm, mixing with sleet late 9 42 32 1.76 1.0 4 F,S,G Heavy sleet/freezing rain/rain overnight, windy & colder late PM 10 32 18 2 Variably cloudy, windy/blustery 11 29 16 1 Partly cloudy, windy, blustery & cold 12 39 20 1 Partly cloudy, breezy 13 36 24 .35 T 1 F,G Rain/freezing rain 14 46 35 T Mostly cloudy, mild, light S winds 15 46 30 T T Mostly cloudy, few late flurries 16 34 23 T Partly cloudy 17 36 20 Partly cloudy, becoming mostly cloudy 18 32 23 * * Mostly cloudy, snow developing during the evening 19 25 23 1.44 16.5 7 Snow, heavy at times, tapering off late evening, 16.5" storm total 20 35 23 16 Mostly sunny, gusty west winds 21 35 26 13 Mostly cloudy 22 33 30 11 Mostly cloudy 23 37 23 10 Sunny 24 35 10 9 Partly to mostly cloudy, cold AM 25 35 24 .58 0.3 9 F,S,G Sleet, freezing rain & rain 26 41 35 .25 T 7 F Occasional rain, drizzle, fog .83" storm total precip 27 44 27 6 Partly cloudy 28 29 25 .01 0.5 5 Mostly cloudy, snow showers, blustery NW winds 15-30 mph 29 27 19 T T 5 Partly cloudy, cold, gusty West winds 30 26 13 4 Partly sunny, cold 31 34 24 .19 2.0 6 AM snow, PM drizzle AVG/SUM 36.5 25.4 6.31 28.3 4.1 (mean depth) EXT 53 10 1.76 16.5 16 Date 1 24 9 19 20 *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 31.0 F Year precipitation to date: 43.91" (final total for 2009) Season snowfall to date: 28.3" Number of days with: Fog 4 Sleet 3 Glaze 3 NOTES/SIGNIFICANT EVENTS 1: Mild high 53 F 2: PM rain heavy at times 3: Heavy downpour overnight with cold front passage. SW wind gusts to 30 mph. 0.79" total rain. 5: Steady snow all day 5.0" fell. Yet another signficant December 5th snowfall. We have had 5 major snow storms on Dec. 5th since 1996: 1996: 5.0" (0.52" precip) 2002: 7.0" (0.84" precip) 2003: 7.0" (0.70" precip) 2007: 4.5" (0.32" precip) 2009: 5.0" (0.44" precip) 8-9: Heavy snow/ice/rain storm. Heavy snow began ~ 8pm mixing with and changing to sleet late evening. Heavy sleet/freezing rain then heavy rain in the predawn hours of the 9th. Precip ended by 8am. 1.76" fell since midnight, setting a daily precip record. All of this storm's hefty precip total 2.26" fell in only 12 hours. 3.0" snow on the 8th is also a daily snow record. Became windy during the afternoon of the 9th. Severe thunderstorms passed north of the area with cold front. 10-12: Persistent gusty winds & cold 13: Rain & freezing rain. Light coating of ice/glaze on elevated surfaces 18-19: The biggest snow storm since February 2003 hammers the area with well over a foot of snow. At this station 16.5" fell, shattering a daily snowfall record for the 19th. This is also the 2nd heaviest snow day and storm on December record. 1.44" of precip on the 19th also sets a daily record, beating the record of 1.23" set just last year in 2008. Areas to our south & east were even harder hit from this intense Nor' Easter, with upwards of 2 feet in some areas. 24: Cold low 10 F. 25: A rare White Christmas with 9" of snow on the ground at 7am. Also an icy Christmas with sleet and freezing rain, 0.3" of sleet/glaze. Rain/fog on the 26th, storm total 0.83" precip. 28: Cold and blustery with lake-effect snow showers/squalls. Light accumulations here with heavy amounts falling in the mountains to the north & west. 31: Steady snow early this morning prior to daybreak with 2" of snowfall. Light drizzle in PM hours. MONTHLY SUMMARY For the third consecutive year, December brought a blitz of nasty winter storms and heavy precipitation. 6.31" of total precipitation made this the wettest December on record. It was also the 2nd snowiest December on record with a whopping 28.3" of snowfall. The snowiest December was 1969 with 34.0 inches. The Nor' Easter on the 19th was one of the most intense storms and the biggest snowfall since 28" fell from a massive storm on Feb. 15-17, 2003. 16.5" fell, the 2nd heaviest daily snowfall in December. The record is 20.0" on Dec. 10, 1992. 23.5" fell from that storm, also a very intense Nor' Easter. It was also noteworthy that the season's first measurable, and signficant snowfall, once again occurred on the 5th of December. This is the 5th time since 1996 and the 4th in the past 8 years with heavy snow on Dec. 5th. A potent Midwest storm brought 2.26" precipitation and 4" of snow/ice in only 12 hours on the 8th and 9th. The 13th and 25th (Christmas) also saw signficant ice storms in the area, and another light snow early on New Year's Eve capped off a very wet, snowy and icy month. Temperatures were below normal during the month, with a fair amount of variation but a lack of extremes. Low temperatures were near normal (25.4 F vs. 25.1), but high temperatures were well below normal, 36.5 F compared to a normal of 40.7 F, so the max temperature anomaly accounted soley to the below normal temperatures and the coldest December since the near-record cold December of 2000. No daily temperature records were set, and the month's extremes were quite modest with 53 on the 1st and 10 on Christmas Eve. December's max temperature pattern was typical of 2009 - below normal - in fact 2009 finished as the 4th coolest in the max temperature department with a mean max of 59.9 F, the coldest since 2003. However, the negative anomaly in the max temperatures was virtually offset by the positive anomaly in the min temperatures - a recurring theme in the past 5 years - so 2009 had close to normal temperatures. ADDITIONAL NOTES/RECORDS 5: 5.0" snow not a record but continues an unusual stretch of years with early season heavy snows on Dec. 5. In 1996 we had 5", in 2002 & 2003, 7", in 2007, 4.5", and now in 2009, 5". This was also the first measurable snowfall of the season. 8: Record daily snowfall 3.0" of snow/ice 9: Record daily precipitation 1.76" from heavy ice storm 19: Record daily precipitation 1.44" breaking the record of 1.23" set just last year in 2008 19: Record-smashing daily snowfall of 16.5" is also the 2nd heaviest snow day ever in December. December 2009 is the wettest December on record with 6.31", eclipsing the record 6.30" in 1969. December 2009 is also the 2nd snowiest December with 28.3" of snow/ice. Dec. 1969 had 34.0" snow. The year 2009 finished with the 4th coolest mean max temperature of 59.9 F.