BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, DECEMBER 1, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME STRONG WINDS BRINGING IN COLD AND DRY AIR TODAY... NOVEMBER 2007 COLDER AND DRIER THAN NORMAL... ANNUAL RAINFALL DEFICIT APPROACHING EIGHT INCHES... An arctic cold front crossed New England early this morning, and much colder and drier air is moving in on strong W-NW winds. Snow virga was observed in all directions this morning, though no snow was observed on the summit. The peak wind gust has been 55 mph WNW at 0940E as observed on our NWS 420C wind system, and the highest hourly wind speed has been 32 mph for the hour from 9-10 AM. This is the highest wind since mid-April. The temperature has been dropping all day from at high of 33 at midnight to 23 as of 1 PM. At mid-afternoon the dew point is down to 1 deg F. November 2007 was cooler and drier than average, while Fall 2007 was warmer and drier than average. The annual rainfall deficit now stands at 7.82 inches through November. Peak Gusts today: NWS 420C: 55 mph WNW at 9:40 AM (observed on dial) Aerovane: 56 mph WNW at 9:31 AM ASOS: 55 mph NW at 9:41 AM Davis: 51 mph WNW at 9:31 AM November 2007 Summary Temp Max: 48.1 deg F [-1.2] Temp Min: 32.6 deg F [-1.6] Temp Mean: 40.4 deg F [-1.4] Temp Mean (corrected): 39.9 deg F Heating Degree Days: 734 [+36] Precipitation: 3.30 inches [-1.34] Snowfall: 0.8 inches [-1.9] Wind Speed (corrected): 13.6 mph, W Peak Gust: 51 mph N [3rd] and W [16th] Mean Station Pressure: 993.0 mb (29.32 inches) Mean Vapor Pressure: 6.1 mb Fall 2007 (Sep-Nov) Summary Temp Max: 63.3 deg F [+3.1] Temp Min: 45.9 deg F [+2.5] Temp Mean: 54.6 deg F [+2.8] Precipitation: 7.85 inches [-5.34] Today's observations: 7 A.M. Weather: Scattered stratocumulus, snow virga NE-E Temperature: 27F, Dew point: 10F, Wind: W at 18G28 kts Wind: peak gust past hour 30 kts Sea-level pressure: 30.18 inches Hg, rising Visibility: 50 miles 6-hour min temp: 27F BHO SA 1155 50 SCT 65 SCT 50 221/27/10/2818G28/018/ VIRGA NE-E PK WND 2730/1056/ 8/500 53037 10033 20027 10 A.M. Weather: Scattered stratocumulus, snow virga distant ESE Temperature: 27F, Dew point: 4F, Wind: W at 26G37 kts Wind: variable WSW-NW, peak gust past hour 47 kts, WNW Sea-level pressure: 30.24 inches Hg, rising Visibility: 75 miles BHO SA 1455 50 SCT 75 241/27/4/2826G37/024/ VIRGA DSNT ESE WND 25V31 PK WND 2947/40/ 8/500 51020 1 P.M. Weather: Thin scattered cirrus, few cumulus Temperature: 23F, Dew point: 1F, Wind: NW at 20G30 kts Wind: Variable W-N, peak gust past hour 36 kts Sea-level pressure: 30.36 inches Hg, rising rapidly Visibility: 75 miles 6-hourly max. temp: 28F 6-hourly min. temp: 23F BHO SA 1755 250 –SCT 75 281/23/1/3120G30/036/ FEW CU ALQDS PRESRR WND 27V35 PK WND 3036/35/ 8/101 53040 10028 20023 WEATHER SUMMARY FOR FRIDAY, NOVEMBER 30 TEMPERATURE (DEGREES F) MAX.....40 NORMAL.....44 MIN.....30 NORMAL.....29 MEAN....35 NORMAL.....37 DEPARTURE FROM 30-YEAR NORMAL...........-2 TOTAL DEPARTURE FOR THE MONTH..........-38 [-1.5 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............30 DEPARTURE.......+2 TOTAL HEATING UNITS FOR THE MONTH...........734 DEPARTURE......+36 TOTAL HEATING UNITS FOR THE SEASON.........1080 DEPARTURE.....-209 TOTAL HEATING UNITS LAST SEASON TO DATE....1053 DIFFERENCE.....+27 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............38 W AT 1:58 A.M. AEROVANE.............37 W AT 1:58 A.M. ASOS.................36 W AT 2:00 A.M. DAVIS................37 WSW AT 1:58 A.M. FASTEST MILE FOR YESTERDAY..............29 W AT 1:59 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........28 W AT 2:01 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........30 W AT 2:00 A.M. AVERAGE WIND SPEED AND DIRECTION......15.5 W ASOS...............15.1 DAVIS..............16.3 SW [236 deg] * Last of several occurrences. PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE....-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........3.30 DEPARTURE....-1.34 ASOS..............3.39 TOTAL PRECIPITATION FOR THE YEAR..........38.84 DEPARTURE....-7.82 ASOS.............38.22 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.1 TOTAL SNOWFALL FOR THE MONTH................0.8 DEPARTURE.....-1.9 TOTAL SNOWFALL FOR THE SEASON...............0.8 DEPARTURE.....-2.1 PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 2007...CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW*/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available * entries for daily snowfall beginning 19th 11/1 66/42/54/+7/0/050/08 37 S 11/2 50/37/44/-2/0/446/73 29 NE 11/3 46/40/43/-3/0.95/000/00 51 N Aero 50 MPH NNW 11/4 54/37/46/0/0/503/82 33 W Aero 33 MPH W 11/5 56/40/48/+3/0/483/79 29 SE 11/6 53/37/45/0/0.75/000/00 35 SSE Aero 35 MPH SSE 11/7 50/32/41/-4/0/551/91 30 W 11/8 43/28/36/-8/0/494/82 22 W 11/9 44/32/38/-6/0.09/331/55 21 NNE 11/10 39/28/34/-10/0.05/383/64 32 N 11/11 42/24/33/-10/0/590/99 23 WNW 11/12 42/27/35/-8/0.02/024/04 25 SSE 11/13 55/42/49/+6/0.33/308/52 28 S 11/14 58/41/50/+8/0/507/86 37 S 11/15 64/40/52/+10/0.41/035/06 44 SSE Aero 46 MPH SSE 11/16 44/30/37/-5/0.31/158/27 51 W Aero 54 MPH W 11/17 40/28/34/-7/0/350/60 37 W 11/18 41/29/35/-6/0/495/85 25 ENE 11/19 36/30/33/-8/0.01/0.1/030/05 29 N 11/20 37/29/33/-7/0.09/0.7/000/00 22 SE 11/21 48/32/40/0/0.01/0/000/00 21 N 11/22 64/40/52/+12/0.01/0/212/37 36 W 11/23 40/23/32/-7/0/0/503/88 36 W 11/24 32/16/24/-15/0/0/468/82 26 WNW 11/25 48/28/38/-1/0/0/0/557/98 28 S 11/26 58/35/47/+9/0.23/0/000/00 44 S Aero 46 MPH S 11/27 61/38/50/+12/0.04/0/328/58 45 S Aero 49 MPH S 11/28 43/30/37/0/T/0/502/89 37 W 11/29 48/34/41/+4/T/0/022/04 38 S 11/30 40/30/35/-2/0/0/.../.. 38 W 12/1 morning low temp. 27F; normal low temp. is now 29F NEW DAILY RECORDS FOR NOVEMBER 2007: NONE DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 1 HIGH 70 IN 2001 LOW 3 IN 1887 PRECIP 1.46 INS. IN 1917 SNOW 2.0 INS. IN 1902 PEAK GUST 72 MPH NW IN 1964 RECORDS FOR DECEMBER 2 HIGH 61 IN 1998 LOW 3 IN 1890 PRECIP 2.09 INS. IN 1974 SNOWFALL 5.0 INS. IN 1894,1929 PEAK GUST 89e MPH SSE IN 1942 TODAY'S REPORT PREPARED By: Mike Iacono If you do not wish to receive this Daily Discussion and Climate Summary from the Blue Hill Observatory, please send an email to sitemaster@bluehill.org.