MONTHLY WEATHER DATA AND OBS - LAVALE MD SEPTEMBER 2011 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 75 62 .81 F,T Heavy AM thunderstorms, partial PM clearing 2 76 67 F AM fog, mostly cloudy 3 91 70 F AM fog, partly cloudy, hot & humid 4 85 69 .25 T Mostly cloudy, warm, PM t-showers 5 72 59 1.18 F Steady rain, cooler 6 59 56 3.52 F Heavy rain all day, very cool 7 66 58 .74 F Overnight rain, mostly cloudy, cool 8 73 64 .05 F Mostly cloudy, late PM rain showers 9 71 66 .69 F Periods of rain, cool 10 80 65 Partly cloudy & warmer 11 76 60 Partly cloudy 12 78 57 Mostly sunny 13 76 58 Partly cloudy 14 80 58 T Increasing clouds, warm, late PM sprinkle 15 60 50 .70 T Strong overnight t-storms, overcast, blustery 16 57 40 Partly cloudy, breezy, cool 17 63 47 T Partly to mostly cloudy, sprinkles 18 66 50 Partly sunny 19 63 50 .08 Mostly cloudy, light PM rain 20 65 58 .03 F Early AM brief shower, mostly cloudy 21 74 60 .01 F Mostly cloudy, brief PM shower 22 78 64 Partly cloudy 23 68 61 .03 AM shower, mostly cloudy, PM clearing 24 73 55 .03 AM shower, partly sunny 25 76 61 .02 AM shower, partly to mostly cloudy 26 76 65 Partly to mostly cloudy 27 74 65 1.12 T AM rain, partial clearing, strong PM t-storms 28 75 64 .06 A few showers then PM clearing 29 66 53 .03 Light rain showers 30 62 55 Partly sunny AVG/SUM 71.8 58.9 9.35 0.0 - EXT 91 40 3.52 - - Date 3 16 6 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 65.4°F (+1.2°F) Year precipitation to date: 40.48" (+9.16") Monthly precipitation departure: +5.86" (normal Sep. 3.49") Season snowfall to date: 0.0" Number of days with: Fog 10 Thunder 4 NOTES/SIGNIFICANT EVENTS 1: Heavy AM thunderstorms .81" of rainfall. 3-4: Hot & very humid. High of 91 on the 3rd, heat index near 110. PM t-storms (4th). 5-7: Steady rain, becoming heavy on the 6th, ending early on the 7th. A total of 5.69" of rain fell from the evening of the 4th to the morning of the 7th due to the remnants of Tropical Storm Lee stalling over the area. Very heavy rain to east. 8-9: More rain showers from the remnants of Lee, another .74" fell. Storm total 6.43" over 6 days is the highest tropical storm total, beating Agnes's 6.09" from June 18-23, 1972. Some of the central-eastern parts of MD had severe floods due to training bands of heavy rain and thunderstorms dumping on the same areas. 15: Strong cold front passage, strong storms overnight, .70" rain. Cool low 40 (16th). 19-21: Another cool weather period with occasional brief rain showers. 23-25: Brief AM showers all 3 days, nothing heavy. 27: A train of severe afternoon thunderstorms narrowly passing east & south of this station. Large hail, damaging winds, funnel clouds reported from these storms. Ft. Ashby WV got 3.92" of rain from the storms, prompting flood warnings for Mineral/ Hampshire Co. WV and central/eastern Allegany Co. where ~2-3" of rain fell from Cumberland south & eastward. Tornado warnings went in effect for the same areas. 28-30: Cool, showery, most of the rain showers were from the mountains north/westward. Additional Notes/Records: 3: Daily record high min 70 F. Old record 68 in 2003. 4: Daily record high min 69 F. Old record 69 in 2003. 5: Daily record rainfall 1.18". Old record 0.71" in 1962. 6: Daily record low max 59 F. Old record 64 in 2004. Earliest sub-60 max temp on record. Rainfall of 3.52" is the 4th heaviest rain day for the month of September and the 8th heaviest rain day since records began in 1948. However, the 3.52" total falls well short of the daily and all-time station record 5.20" that fall this date in 1996 from Hurricane Fran. 7: Daily record low max 66 F. Old record 68 in 1949. 9: Daily record rainfall 0.69" eclipses 0.67" in 1987. 19: Daily record low max 63 F. Old record 65 in 1969. 26: Daily record high min 65 F. Old record 64 in 2005. 28: Daily record high min 64 F. Old record 63 in 2004. September 2011 was the 2nd wettest September and 4th wettest month overall with 9.35" of precipitation. September's mean min of 58.9°F is the 2nd warmest on record, just missing the record of 59.1°F set in 1971. MONTHLY SUMMARY September 2011 will be well remembered for its excessive amounts of rain from the remnants of Tropical Storm Lee, which stalled over the Mid-Atlantic states, shortly after Hurricane Irene hammered the east coast in late August. Many parts of the state, especially central and eastern sections, had over 10 inches, some over 15. Lee was responsible for 6.43" of rain at this location, setting a new record for most rain associated with a tropical storm, although the rains came over a 6-day period from the 4th-9th. The previous tropical storm record was 6.09" from Agnes, also in a 6-day period from June 18-23, 1972, followed closely by Juan in Nov. 1985 with nearly 6" in 2 days. The heaviest tropical deluge occurred prior to LaVale records in October 1942, when nearly 8" of rain fell in 3 days. This September's total precipitation reached 9.35", the 2nd wettest September on record. The wettest September was 1996 with 9.87". That month, this station's daily record 5.20" of rain fell on the 6th from TS Fran. This month, 3.52" of rain was recorded on the same date, the 6th. Remarkably, the 9.35" month total was very close to my other station (Westmont 1W PA) and Creasaptown-BelAir's CoCoRaHS station total 9.37", about 6 miles SSW of here. Several other rain events dropped mostly light amounts of rain on the area. The most notable systems apart from Lee brought strong thunderstorms on the 1st (0.81"), 15th (0.70") and 27th (1.18"). On the 27th, severe thunderstorms hammered areas just to our south & east. Nearly 4 inches of rain fell just to our south in Fort Ashby, WV and nearly 3" in Oldtown to our SE. This train of severe thunderstorms included large hail, damaging winds, and prompted tornado warnings from Cumberland eastward. Speaking of Cumberland, their monthly total of 9.71" set a new September record, surpassing 1996's 9.05" mark. It was their wettest month in over 96 years and 3rd wettest month on record. The wettest was Aug. 1915 with 12.20" and 2nd wettest was June 1892 with 10.08". Temperatures were quite unremarkable, with little diurnal variations and a lack of extremes due to all of the clouds and rain. Overall, it was a mild month, the 8th consecutive month with above normal temperatures, which were a result, once again, of well above normal mins. There were 4 record high min temps, though there were also 3 record low max temps. The 3rd was quite hot with a high of 91, before Lee's cold heavy rains moved in. 3 days later, on the 6th, the high was only 59, the earliest sub-60 degree high temperature on record. After a brief warm-up, the cold front that brought the thunderstorms on the 15th ushered in a brief cold spell, with the month's two lone readings in the 40s occurring on the 16th-17th. The balance of the month had relatively consistent temperatures, 60s and 70s for highs and 50s and 60s for lows.