BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, JANUARY 21, 2008, MARTIN LUTHER KING DAY ALL TIMES ARE IN EASTERN STANDARD TIME MODIFIED COLD ARCTIC AIRMASS ARRIVED SUNDAY LOW TEMPERATURE OF 10 DEGREES THIS MORNING The arrival of the Arctic air yesterday was accompanied by gusty WNW winds up near 40 MPH during the morning. The morning low temperature of 22 degrees by 9 a.m. could only recover to 24 degrees during the afternoon. However, gusty winds diminished during the afternoon and backed to west-southwest and southwest by evening. The coldest of the cold airmass remained well to our west and northwest so this morning's low of 10 degrees was far from being the coldest of the month which was 2 degrees way back on January 3rd and 4th. Today's observations: 7 A.M. Weather: Clear, stratocumulus along/offshore NNE-ESE and distan along horizon distant SE-SSW Temperature: 10F, Dew point: -1F, Wind: SW at 12 kts Sea-level pressure: 30.55 inches Hg, rising Visibility: 45 miles 6-hour min temp: 10F 24-hour precip: 0 inches Snow depth on ground: 3 inches BHO SA 1155 CLR 45 347/10/-1/2312/055/ SC LYR ALG/OFFSHR NNE-ESE AND ALG HRZN DSNT SE-SSW/ 8/500 4/003 51038 10012 20010 10 A.M. Weather: Clear, few stratocumulus distant WNW-N and along and offshore NNE-ESE Temperature: 15F, Dew point: -1F, Wind: WSW at 14G24 kts Wind: Peak wind WSW @ 27 kts @ 12 past the hour and wind variability is from SW-W Sea-level pressure: 30.62 inches Hg, rising Visibility: 60 miles BHO SA 1455 CLR 60 369/15/-1/2414G24/062/ FEW SC DSNT WNW-N AND ALG/OFFSHR NNE-ESE PK WND 2427/13/ WND 21V27/ 8/500 1 P.M. Weather: Clear, few cumulus, cumulus fractus Temperature: 20F, Dew point: 1F, Wind: WSW at 17G28 kts Wind: Peak wind WSW @ 30 kts @ 39 past the hour and wind variability is from SW-WNW Sea-level pressure: 30.58 inches Hg, falling Visibility: 60 miles BHO SA 1755 CLR 60 356/20/1/2517G28/058/ CUFRA/CU XCPT SE-S FEW CI WNW-N PK WND 2630/39/ WND 22V29/ 8/101 58013 10020 20010 WEATHER SUMMARY FOR SUNDAY, JANUARY 20 TEMPERATURE (DEGREES F) MAX.....29 NORMAL.....33 MIN.....13 NORMAL.....17 MEAN....21 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL...........-4 TOTAL DEPARTURE FOR THE MONTH.........+128 [+6.2 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............44 DEPARTURE.......+5 TOTAL HEATING UNITS FOR THE MONTH...........649 DEPARTURE.....-126 TOTAL HEATING UNITS FOR THE SEASON.........2816 DEPARTURE......-287 TOTAL HEATING UNITS LAST SEASON TO DATE....2450 DIFFERENCE.....+366 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............38 WNW AT 9:39 A.M. AEROVANE.............36 WNW AT 9:39 A.M. ASOS.................36 WNW AT 9:39 A.M. DAVIS................38 W AT 9:38 A.M. FASTEST MILE FOR YESTERDAY..............26 WNW AT 9:45 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........25 WNW AT 9:50 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........27 W AT 1:02 P.M. AVERAGE WIND SPEED AND DIRECTION....... 15.8 W ASOS.................15.6 DAVIS................16.1 W [280] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE.....-0.16 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........3.67 DEPARTURE.....+0.55 ASOS..............3.78 TOTAL PRECIPITATION FOR THE YEAR...........3.67 DEPARTURE.....+0.55 ASOS..............3.78 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.....-0.5 TOTAL SNOWFALL FOR THE MONTH...............12.3 DEPARTURE.....+2.3 TOTAL SNOWFALL FOR THE SEASON..............42.8 DEPARTURE....+19.2 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2008 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 1/1 38/28/33/+6/0.24/1.8/055/10 30 E 1/2 29/7/18/-9/T/T/006/01 43 NW Aero 43 MPH NW 1/3 11/2/7/-20/0/0/539/98 35 NW 1/4 30/2/16/-11/0/0/253/46 31 SSW 1/5 38/24/31/+4/0/0/292/53 28 SSW 1/6 47/34/41/+15/0/0/133/24 27 SSW 1/7 54/39/47/+21/0/0/183/33 29 S 1/8 65/45/55/+29/0/0/278/50 37 S 1/9 59/42/51/+25/0.01/0/167/30 48 S 1/10 47/35/41/+15/0/0/335/60 35 W 1/11 55/35/45/+19/1.58/T/0/0 46 S Aero 48 MPH S 1/12 47/32/40/+14/0/0/376/67 28 W 1/13 42/30/36/+10/0/0/455/81 33 ENE 1/14 36/24/30/+4/1.45/10.3/000/00 37 NE Aero 36 MPH NE 1/15 30/21/26/0/T/T/000/00 25 NW 1/16 30/16/23/-3/0/0/.../.. 28 NW 1/17 32/17/25/-1/T/T/.../.. * 23 ESE Aero 19 MPH ESE 1/18 44/28/36/+10/0.39/0.2/.../.. 41 W Aero 39 MPH W 1/19 33/24/29/+4/0/0/.../.. 25 W 1/20 29/13/21/-4/0/0/.../.. 38 WNW Aero 40 MPH WNW 1/21 morning low temp. 10F; normal low now 17F * Precipitation and snowfall corrected for 1/17. NEW DAILY RECORDS FOR JANUARY 2008: 1/8 - New record high temperature of 65 deg; the previous record, 59 deg. in 1930 New record high minimum temperature of 45 deg; the previous record, 41 deg. in 1930, 1935, 1967 1/9 - New record high minimum temperature of 42 deg; the previous record, 39 deg. in 1937, 1956. 1/11 - New record rainfall of 1.58 inches; surpasses previous record of 1.14 inches in 1956 1/14 - New record daily snowfall of 10.3 inches; surpasses previous record of 9.0 inches in 1999. New record maximum daily precipitation of 1.45 inches; surpasses 1.35 inches in 2006 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 21 HIGH 65F IN 1906 LOW -4F IN 1888,1893 PRECIP 2.49 INCHES IN 1979 SNOWFALL 7.5 INCHES IN 2001 PEAK GUST 78e MPH SE IN 1979 RECORDS FOR JANUARY 22 HIGH 59F IN 1916 LOW -8F IN 1888,1976 PRECIP 1.24 INS. IN 1891,1987 SNOWFALL 10.0 INS. IN 2005 PEAK GUST 67 MPH W IN 1976 TODAY'S REPORT PREPARED By: Robert Skilling