MONTHLY WEATHER DATA AND OBS - LAVALE MD OCTOBER 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 58 48 Partly cloudy 2 56 46 .18 Partly sunny to mostly cloudy, PM rain 3 62 49 F AM fog becoming partly cloudy 4 59 45 Mostly to partly cloudy, breezy 5 62 43 Partly cloudy, NW breezes to 20 mph 6 60 42 Partly cloudy becoming mostly cloudy PM 7 64 47 .12 DW Overnight showers, strong W wind gusts to 45 mph, partly cloudy 8 67 41 Partly to mostly cloudy, SW winds gusting to 25 mph 9 72 57 .19 Some rain early and late, mild, partial clearing mid-PM 10 57 44 Partly sunny, light N winds 11 60 39 Partly cloudy to mostly sunny 12 55 38 Mostly cloudy 13 59 42 Partly to mostly cloudy 14 42 37 .12 Mostly cloudy, very cool with PM light rain 15 40 38 .74 F Cold steady rain, some snow flurries at higher elevations 16 38 36 .38 F Cold light rain continuing 17 42 36 .20 F Continued cold, periods of rain, E winds to 15 mph 18 43 36 T F Cool, partial clearing, windy with 30 mph gusts from NNE 19 55 30 Partly cloudy. First frost and freeze this morning. 20 64 36 Partly to mostly sunny, milder 21 72 41 Partly cloudy, mild 22 74 42 Partly to mostly sunny, mild, wind shifting to S 23 61 50 1.14 Steady rain developed, heavy at times in the PM hours 24 64 49 1.13 AM rain heavy at times, clearing PM, W winds to 25 mph 25 58 44 Partly cloudy 26 63 37 Partly cloudy 27 55 45 .69 Mostly cloudy, PM steady rain 28 57 51 .27 Mostly cloudy, AM showers 29 58 54 Partly to mostly sunny 30 57 53 .06 Mostly cloudy, brief shower 31 62 44 .03 Mostly cloudy, breezy with a few passing showers AVG/SUM 57.9 43.2 5.25 0 - EXT 74 30 1.14 - - Date 22 19 23 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 50.6 F Year precipitation to date: 36.06" Season snowfall to date: 0.0" Number of days with: Fog 5 Damaging Winds 1 NOTES/SIGNIFICANT EVENTS 2: Somewhat cool with evening rain showers. Max of 56 ties record low previously set in 2003. 7: Strong cold front passed through overnight. Some rain showers followed by falling temps and west winds gusting to 45 mph, causing some scattered tree damage in the area. 9: Mild high of 72 and low 57. Some rain early and late but this system seemed to split with most of the rain passing north and south, especially north. 14-18: An unusually cold stretch of days with two systems bring a cold steady rain, which was mixed with snow and sleet at higher elevations. All five days smashed previous records for record low max temperatures. The high of 38 on the 16th is the earliest ever day in a cold season with a max only in the 30s. 19: First frost and freeze of season with a morning low of 30 F. 20-22: Quick rebound in temperatures with a mild Indian summer. 72F on the 21st and a monthly high of 74F on the 22nd. 23-24: Heavy rains 2.27" fell in a 24-hour period. However, no records were set as this event was broken almost exactly in half by the midnight observation time. Moderate to heavy rains fell during the PM hours of the 23rd, 1.14" by midnight. Another 1.13" fell from a second round of heavy rain during the early to mid morning hours of the 24th. Skies cleared in the afternoon with breezy conditions. 27-28: Steady rain began the afternoon of the 27th and mostly ended pre-dawn on the 28th with a few lingering showers during the day. Another .96" of rain fell from this event. 29: A new daily record high min of 54 was set, eclipsing the previous record of 53 in 2004. 30-31: Few scattered showers both days. Cold front approached on the 31st with breezy weather and temperatures falling during the evening. MONTHLY SUMMARY October was quite active with many weather systems passing through the area, bringing well above normal precipitation, which exceeded 5 inches for the 4th time in 2009. Temperatures were on the cool side, with 7 records set. 6 days set records for record low max temperatures, 5 of which were consecutive from the 14th-18th, when an abnormally deep trough and two low pressure systems, one passing to our north in PA and the other to our east along the Mid- Atlantic coast, kept temperatures in the upper 30s to low 40s with a cold steady rain. Heavy snows fell in the mountains to our north. The State College area of central PA was hit hardest with a record heavy and record early snow storm, with 4 to 9 inches in that area. The high on the 16th only reached 38, the earliest ever day in the 30s. The season's first frost and freeze finally occurred on the 19th. However, temperatures rebounded quickly into the 70s on the 21st-22nd, with the month's high of 74 set just 3 days after the month's low of 30. Heavy rains, totaling 2.27", followed on the 23rd-24th. Another large system dropped .96" of rain on the 27th-28th. The month's final record, a high min of 54, was set on the 29th, before another front approached on Halloween, with a few showers on the final two days of October. Given the frequent cloud cover and the record cold temperatures at mid-month, the mean max temperature was very cool, 57.9 F, in fact the 2nd coolest on record for October. The coolest was 57.2 in the record cool October of 1957. It was noteworthy that the mean max temperature this month was colder than the average temperature 2 years ago in October 2007! That month had a mean of 58.8 F and was the 3rd warmest October on record. Meanwhile, low temperatures were above normal (43.2 vs. 41.4) for the 8th of 10 months in 2009, but did not nearly offset the cool max temperature anomaly. The monthly mean temperature of 50.6 F is 0.90 standard deviations the below normal of 53.2 F. In a nutshell, cool and wet would sum up October 2009. Additional notes/records 2: Record low max 56 F 14: Record low max 42 F 15: Record low max 40 F 16: Record low max 38 F. Earliest ever cold season high temperature readings in the 30s. 17: Record low max 42 F 18: Record low max 43 F. 5th consecutive record low max. 29: Record high min 54 F. October 2009 had the 2nd coolest mean maximum temperature on record, 57.9 F.