MONTHLY WEATHER DATA AND OBS - WESTMONT 1.1W PA SEPTEMBER 2009 OBSERVERS NATE AND STEVE 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 24-hour At Rain Snow/ Snow Date Max Min Obs Equiv Ice Depth Special Obs. 1 66 46 51 F 2 69 46 53 F 3 71 48 55 F 4 74 48 59 5 74 51 60 F 6 73 54 63 F 7 67 62 62 .08 8 68 60 60 .01 9 68 58 61 .06 10 65 54 54 .05 11 58 51 54 .08 F 12 57 53 57 .01 F 13 73 55 60 14 70 57 60 F 15 72 55 59 F 16 64 54 59 17 58 53 55 T 18 70 54 58 F 19 71 46 56 20 72 50 60 21 72 56 65 T F 22 69 62 63 .05 23 74 61 62 .13 T 24 70 62 62 .01 F 25 66 52 52 .01 26 52 52 52 1.13 27 55 52 54 .35 28 65 48 48 .26 F,T 29 48 45 45 .21 F 30 46 44 44 .15 F AVG/SUM 65.9 53.0 56.8 2.59 0.0 - EXT 74 44 - 1.13 - - Date 23* 30 - 26 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 59.4 F Year precipitation to date: 33.28" Season snowfall to date: 0.0" Number of days with: Fog 15 Thunder 2 DETAILED OBSERVATION NOTES 1: Cool AM low 46 F. Patchy dense fog then sunny & pleasant w/ light NE winds. 2: Early fog and cool then clear/sunny. Light/variable east winds. 3: Sunny/clear & pleasant, light/variable winds 4: Mostly sunny & mild with light E winds 5: Light fog & partly cloudy skies early, becoming mostly sunny 6: Valley fog, then mostly sunny, with increasing PM clouds 7: Heavy overcast with light SE winds, steady temperatures, .08" rain from 7-9am 8: Mostly cloudy, light AM shower, light SE winds 9: Light overnight rain .06", mostly cloudy, very light E winds 10: Overnight rain shower .05", mostly cloudy, occasionally gusty E winds 11: Weak mid-morning sun, then overcast with PM light rain .08" fell. Light NE winds. 12: Drizzle & fog overnight. Calm to light winds finally shifting to NW. Cloudy all day. This is the first day without E, SE or NE winds - very unusual to have so many days in a row with east winds! 13: Sunny, brilliant day with pleasant temperatures and light NW breezes 14: Variably to mostly cloudy, light W breezes 15: AM clouds & fog with partial PM clearing 16: Mostly clear early then variably to mostly cloudy, winds light from N/NE 17: Overcast & cool, brief AM drizzle, light/variable winds 18: Fog early, then sunny & pleasant 19: Sunny and pleasant after a slightly cooler morning 20: Mostly sunny, light winds from S/SW this time, increasing clouds by late afternoon 21: A few morning clouds & patchy fog. Mostly sunny but clouds increased and thickened. Light S winds and a few sprinkles this evening. 22: Light rain 8-10am (.05") and overcast with a couple brief peaks of sun 23: Mild and variably cloudy with heavy thunderstorms to north around 4pm. A couple of brief thundershowers around 5-5:30pm and again at 8:15pm .13" rain fell. 24: Overnight and morning fog/mist. Overcast with light winds shifting from W to N. 25: Light shower overnight, then mostly sunny AM with occasional breezes from N/NE. Increasing clouds again by 2pm, thin overcast this evening 26: Steady rain began around daybreak. Rain all day, heavy at times, 1.13" fell by midnight and was very much needed. Winds were gusty all day from the SE up to 22 mph and the temperature stayed at 52 ALL day. This is the first time in a very long time that I can rememeber the temperature remaining constant for an entire calendar day. 27: Cool and mostly overcast with occasionally gusty W winds and late AM showers, briefly heavy at times .35" rain fell. 28: A gusty thunderstorm around 10am with a quick .25" rain falling, rain ended by 11am, strong SW winds shifted to W and gusted 40+ mph. Partial clearing with falling temperatures and remained very windy through the evening. 29: Overcast, cool and windy (NW gusts 25-30 mph) with lake-effect drizzle and light rain beginning at 4pm and continuing all evening .21" fell. 30: Overnight showers (another .11"). Overcast with occasional brief showers and NW winds slowly diminishing. Again very cool with some partial clearing late. MONTHLY SUMMARY September featured fairly mild temperatures, and, once again, below normal precipitation. This is the 7th out of 9 months in 2009 with subnormal precipitation. Another late-month "precipitation rally" came up well short, as barely a quarter-inch of rain fell the first three weeks. However, measurable rain fell all of the final nine days, with nearly 90% of the month's rain falling during this period. The 2.59" of rain was still 1.56" below the normal of 4.15". Meanwhile, temperatures remained relatively mild until the end of the month, when a series of fronts dropped max temperatures into the 40s. There was little variation in temperatures, with only a 30-degree difference between the month's high and low. The diurnal variation averaged only 12.9, about half of normal. The above-normal temperatures were strictly due to unusually mild overnight lows. In general, September 2009 was a relatively quiet and unremarkable weather month.