MONTHLY WEATHER DATA AND OBS - WESTMONT 1.1W PA AUGUST 2009 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. Temperature, °F Precipitation, In. Liquid Solid 7am 24-hour At Rain Snow/ Snow Date Max Min Obs Equiv Ice Depth Special Obs. 1 75 59 65 T F 2 72 62 63 .19 3 73 57 63 F 4 77 56 66 5 70 63 63 F 6 70 55 59 7 72 53 62 F 8 75 59 65 .03 9 81 65 73 .01 10 84 64 64 .21 T 11 75 64 67 .09 F,T 12 74 62 64 .28 F,T 13 75 57 64 F 14 82 59 68 F 15 83 63 67 16 84 63 66 17 83 64 68 .32 18 78 65 69 .10 T 19 80 66 68 .04 20 79 64 69 .12 F,T 21 75 65 65 .23 22 75 58 64 T 23 70 60 62 T F 24 72 54 60 F 25 76 55 63 F 26 80 60 65 F 27 70 62 66 28 68 63 63 1.44 F 29 71 60 60 .54 30 69 55 55 31 66 51 54 AVG/SUM 75.3 60.1 64.2 3.60 0.0 - EXT 84 51 - 1.44 - - Date 16* 31 - 28 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 67.7 F Year precipitation to date: 30.69" Season snowfall to date: 0.0" Number of days with: Fog 14 Thunder 5 DETAILED OBSERVATION NOTES 1: Fog, mist & light drizzle this morning, lifting by 10am. Variably cloudy, mild & pleasant with calm winds the rest of the day 2: Light rain early this morning, then mostly cloudy with brief shower at 5pm .19" of rain. Another instance of a big system splitting as it approached with heavy rains NW & SE of the area. 3: AM fog, then partly cloudy, light W to SW winds 4: Mostly sunny, mild & pleasant with light SW breezes 5: AM fog. Hazy and mostly cloudy through the day and not as warm. 6: Clear to partly cloudy skies with occasional N to NW breezes 7: Cooler and clear with valley fog this morning. Mostly sunny and pleasant with light W winds 8: Overcast early, becoming sunny. Increasing PM clouds with light rain from 5-7pm. Skies partially cleared towards sunset with a nice rainbow late in the evening. 9: Becoming breezy overnight with W winds gusting 15-25 mph and a light shower at daybreak. Warmer with variably cloudy skies and gusty W winds continuing through the day. Very mild this evening. 10: Warm overnight low 70 F. Partly to mostly sunny skies, warm & humid. Line of thunderstorms moved through around 7:30pm with ominous black skies and strong wind gusts 30+ mph but only brief heavy rain then lighter rains with occasional thunder .21" fell. Temperature dropped to 64 F. 11: Valley fog again this morning. Partly to mostly cloudy with another line of storms this evening that again split as it moved through. Very brief downpour at 5pm then thunder continuing for an hour but only .09" rain fell. 12: Patchy dense fog, then partly to mostly cloudy. Thundershower at 4pm with a brief downpour then lighter rains ending by 5pm .28" fell. Clearing skies during the evening. 13: Dense AM fog then partly sunny becoming clear with calm winds. 14: Valley fog early, otherwise sunny and clear all day with calm winds and warm high 82 F. 15: Fair to partly cloudy and warm with light & variable winds 16: Mostly sunny, warm & humid high 84 F with widespread haze and calm winds 17: Mostly sunny, warm and humid again high 83 F. Very hazy. Surprise localized rain shower this evening from 6-7pm with brief heavy rains and SW wind gusts to 25 mph .32" of rain fell. 18: Mostly cloudy, warm & humid with a brief thundershower at 1:15pm. Storms became severe to our north and east. Remained partly to mostly cloudy and humid through the day. 19: Partly cloudy and warm. Becoming overcast this afternoon with light rain showers from 5-7pm as strong storms tried to move in from the Pittsburgh area but kept dissipating as they approached. 20: Fog this morning then variably cloudy with a brief heavy downpour at 2:20pm (.12" in 10 min). Quickly cleared afterwards. More lightning this evening to our W as a line of severe storms dissipated as it approached but we did get some strong SW wind gusts in excess of 30 mph. 21: A couple of overnight showers .12" fell. Occasional light to moderate AM showers another .11". Skies cleared nicely during the afternoon hours with lower humidities. 22: Variably cloudy with occasional moderate breezes from the west. Sprinkles around 6pm. 23: Variable clouds with a brief period of fog, mist & drizzle around 3pm. Became and remained mostly clear after 4pm. 24: Dense AM fog, slowly lifted beginning at 9am and became mostly sunny with passing clouds. 25: Fog again this morning, lifting at 9:30am and again sunny with a few passing high clouds. 26: Partly to mostly sunny after some early fog and haze, breezy at mid-morning with winds slowly diminishing through the afternoon. 27: Variable clouds, light W winds becoming SW 28: Heavy overcast this morning, fog & light drizzle. Light rain began at 1pm and became heavy by 2pm with a series of downpours during the mid-afternoon. Over 1" of rain fell in 45 minutes from 1:50 to 2:35pm. A little more light rain & drizzle this evening with more fog. 1.44" of rain today, very much needed and is the heaviest rain since May 28th when 1.49" fell. 29: More showers overnight from midnight-3am heavy at times another .45" fell. Variably to mostly cloudy with a brief shower and gusty winds at 2pm another .09" rain. Partial clearing, breezy and cool this evening. 30: Partly to mostly sunny, breezy and cool today. Definitely felt like early fall today. 31: Cooler this morning 51 F, sunny and again cool. Maples in front yard beginning to turn color. MONTHLY SUMMARY August was mild, but not excessively so. There was a period of summer-like temperatures during the middle of the month along with scattered thunderstorms, most of which missed or barely grazed this station. Mid-August was the only time during the entire summer of 2009, minus a couple days in June and July, that actually felt like true summer. The rest of the summer was quite cool. Temperatures averaged 67.7 F, 4.4 degrees warmer than July's record coolness of 63.3 F. There were only 3 days that failed to reached 70, all in the final four days, compared to 13 days in the 60s or lower in July. There were also 8 days in the 80s - more than the rest of the season combined. In general, daytime highs were near normal with above normal overnight lows. A cold front passed through on the 29th and left the final two days feeling like early fall. Precipitation was below normal for the 6th of the first 8 months in 2009. Like July, there was a late-month precipitation rally that still came up short. Only 1.62" of rain fell the first 27 days of August, but 1.98" of rain fell in advance of the cold front on the 28th-29th, bringing the month's total to 3.60", still a half-inch short of the average of 4.10". All three summer months had below normal precipitation, despite an active weather pattern. As noted in July's summary, a lot of the same areas were repeatedly dumped on, while other areas (such as ours) were repeatedly missed, with only a few exceptions. The precipitation distribution this summer was backwards, with the normally wetter mountain areas receiving less rain than the normally drier areas east and west of the mountains. The extreme NW and eastern parts of PA were the wettest.