BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, JANUARY 24, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME COLD FRONT PASSES OVER THE AREA THIS MORNING... GUSTY WINDS USHERING IN MUCH COLDER TEMPERATURES... Friday's high temperature of 39 was the warmest temperature of the month so far, and it was only the third maximum above freezing in the last two weeks. A strong cold front crossed the area a few hours before sunrise, and the temperature has dropped from a relatively warm 35 at 7 AM to the upper 20s at mid-day. A snow squall was reported along the MA/NH border earlier this morning, but only distant virga to the north was visible from the Observatory. The peak gust so far today has been 40 mph W at 10:23 AM and 10:58 AM. With the frontal passage, the wind direction veered from south to west between 3 and 5 AM this morning. Visibility has increased to more than 70 miles to the NW as the dew point has dropped from 32 just after midnight to 9 deg F at 1 PM. Only dim sunshine occurred today before noon, but a sharp clearing line that moved slowly from NW to SE this morning has moved to the south by early afternoon. Today's observations: 7 A.M. Weather: Broken altocumulus and broken cirrus, few stratocumulus SW-NW, clearing line distant W-N, hazy Temperature: 35F, Dew point: 19F, Wind: W at 18G25 kts Wind: Direction variable, WSW-NW Wind: Peak gust 30 kts, W at 6:43 A.M. Sea-level pressure: 29.73 inches Hg, rising Visibility: 40 miles, hazy 6-hour minimum temperature: 35F Snow depth on ground: 12 inches BHO SA 1155 E120 BKN 250 BKN 40 069/35/19/2818G25/973/ FEW SC SW-NW FEW CUFRA W CLRG LINE DSNT W-N HAZY WND 25V31 PK WND 2830/43/ 8/571 4/012 53030 10036 20035 10 A.M. Weather: Broken altocumulus and broken cirrus, stratocumulus W-SE, clearing line WSW-NNE, virga distant N Temperature: 32F, Dew point: 14F, Wind: W at 15G27 kts Wind: Direction variable, WSW-WNW Wind: Peak gust 31 kts, W at 9:12 A.M. Sea-level pressure: 29.83 inches Hg, rising Visibility: 55 miles, 75 miles to NW BHO SA 1455 E150 BKN 250 BKN 55 102/32/14/2715G27/983/ SC W-SE CLRG LINE WSW-NNE SUN DMLY VSBL VSBY NW 75 VIRGA DSNT N WND 24V30 PK WND 2831/12/ 8/571 51032 1 P.M. Weather: Scattered altocumulus and scattered cirrus, few stratocumulus W-E Temperature: 29F, Dew point: 9F, Wind: W at 16G32 kts Wind: Direction variable, WSW-WNW Wind: Peak gust 32 kts, W at 12:49 P.M. Sea-level pressure: 29.85 inches Hg, rising Visibility: 70 miles 6-hour maximum temperature: 35F 6-hour minimum temperature: 29F BHO SA 1755 E150 SCT 250 SCT 70 109/29/9/2716G32/985/ SC W-E WND 24V30 PK WND 2732/49/ 8/531 51007 10035 20029 WEATHER SUMMARY FOR FRIDAY, JANUARY 23 TEMPERATURE (DEGREES F) MAX.....39 NORMAL.....33 MIN.....24 NORMAL.....18 MEAN....32 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL...............+7 TOTAL DEPARTURE FOR THE MONTH..............-89 [-4.1 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............33 DEPARTURE.........-7 TOTAL HEATING UNITS FOR THE MONTH............986 DEPARTURE........+92 TOTAL HEATING UNITS FOR THE SEASON..........3226 DEPARTURE.........+3 TOTAL HEATING UNITS LAST SEASON TO DATE.....2940 DIFFERENCE......+286 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............31 S AT 9:43 P.M. AEROVANE.............30 S AT 9:43 P.M. ASOS.................31 SSW AT 9:43 P.M. DAVIS................33 S AT 9:42 P.M. FASTEST MILE FOR YESTERDAY..............26 S AT 9:36 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........25 SSW AT 9:44 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........24 S AT 9:37 P.M. AVERAGE............12.7 S ASOS...............12.3 DAVIS..............11.3 S [186 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...........2.86 DEPARTURE.........-0.72 ASOS...............3.94 # TOTAL PRECIPITATION FOR THE YEAR............2.86 DEPARTURE.........-0.72 ASOS...............3.94 # # Includes erroneous ASOS precipitation data on 1/1/09 and 1/2/09 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.........-0.5 TOTAL SNOWFALL FOR THE MONTH...............20.6 DEPARTURE.........+9.1 TOTAL SNOWFALL FOR THE SEASON..............51.0 DEPARTURE........+25.9 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2009 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 1/1 16/1/9/-18/0/0/538/98 44 WNW Aero 44 MPH WNW 1/2 32/9/21/-6/0/0/005/01 28 S 1/3 32/21/27/0/T/T/539/98 43 WNW Aero 44 MPH WNW 1/4 35/17/26/-1/0/0/512/93 36 W Aero 33 MPH W 1/5 36/26/31/+4/0.06/0/512/93 30 W 1/6 33/21/27/+1/0/0/183/33 27 W 1/7 36/26/31/+5/1.26/0.8/000/00 46 NE Aero 45 MPH NE 1/8 38/21/30/+4/0.01/0.1/389/70 47 W Aero 45 MPH W 1/9 25/16/21/-5/0/0/546/98 37 W Aero 36 MPH W 1/10 24/11/18/-8/0.10/1.0/329/59 28 W 1/11 31/19/25/-1/0.55/5.3/000/00 30 NW 1/12 27/18/23/-3/0.02/0.4/410/73 24 WNW 1/13 34/16/25/-1/0.04/T/107/19 25 SE 1/14 33/10/22/-4/0/0/518/92 47 W Aero 48 MPH W 1/15 16/5/11/-15/0/0/000/00 20 NW 1/16 17/0/9/-17/0/0/557/98 26 W 1/17 19/1/10/-16/0/0/450/79 23 W 1/18 29/14/22/-4/0.58/9.5/000/00 24 E 1/19 32/19/26/+1/0.24/3.5/057/10 18 NW 1/20 30/17/24/-1/T/T/247/43 30 NW 1/21 23/9/16/-9/0/0/.../.. 25 SW 1/22 31/14/23/-2/0/0/.../.. 31 SW 1/23 39/24/32/+7/0/0/.../.. 31 S 1/24 low temp: 29F (at mid-day), our normal low temp. is now 26F NEW DAILY RECORDS FOR JANUARY 2009... ..NONE.. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 24 HIGH 60F IN 1967 LOW -12F IN 1907 PRECIP 2.04 INS. IN 1998 SNOWFALL 11.3 INS. IN 1935 PEAK GUST 82 MPH S IN 1996 RECORDS FOR JANUARY 25 HIGH 55F IN 1990 LOW -10F IN 1935 PRECIP 2.24 INS. IN 1979 SNOWFALL 12.5 INS. IN 1941 PEAK GUST 81 MPH WNW IN 1972 TODAY'S REPORT PREPARED By: Mike Iacono