BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MARCH 24, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME COLDEST WEATHER SINCE EARLY MARCH LONG DRY SPELL CONTINUES Temperatures are on the rise today after the core of the coldest of the cold air mass passed over just after midnight early today. The low of 18F was our coldest reading since 16F on March 5th. Yesterday's mean of 25F was 13 degrees below average and was the greatest daily departure since minus 16 degrees on March 4th. An increasingly long dry spell continues with less than one quarter inch of precipitation since the 9th of the month. Today's observations: 7 A.M. Weather: Clear, stratocumulus offshore NE-SE Temperature: 23F, Dew point: 6F, Wind: NW at 14G20 kts, Wind: Peak wind gust 26 kts NW at 6:44 A.M. Wind: direction variable W-N Sea-level pressure: 30.31 inches Hg, rising Visibility: 60 miles, 70 miles northwest 6-hour minimum temperature: 18F 24-hour precipitation: 0 inches BHO SA 1155 CLR 60 263/25/9/3114G20/031/ SC ALG/OFFSHR ENE-SE VSBY NW 70 PK WND 3126/44/ WND 27V35/ 8/500 53011 10025 20018 10 A.M. Weather: Cumulus forming, scattered stratocumulus lenticularis forming overhead thru north thru east thru south, mostly clear sky SW-NW, snow virga distant SE Temperature: 35F, Dew point: 12F, Wind: NW at 17G25 kts, Wind: direction variable W-N Sea-level pressure: 30.31 inches Hg, steady Visibility: 60 miles, 70 miles northwest BHO SA 1455 45 SCT 60 265/35/12/3217G25/031/ CU FRMG ALQDS NMRS SCSL FRMG OVHD-N-E-S MSTLY CLR SKY SW-NW VSBY NW 70 VIRGA DSNT SE WND 27V36/ 8/800 50002 1 P.M. Weather: Broken stratocumulus, altocumulus, few lower cumulus, patches of snow virga overhead-N-E-S Temperature: 42F, Dew point: 14F, Wind: NNW at 17G24 kts, Wind: Peak wind 28 kts NNW @ 12:12 P.M. Wind: direction variability WNW-NNE, Wind: direction gradually veering Sea-level pressure: 30.31 inches Hg, steady Visibility: 60 miles, 70 miles NW 6-hour maximum temperature: 44F BHO SA 1755 E60 BKN 80 BKN 60 265/42/14/3417G24/031/ FEW LWR CU PTCHS SNW VIRGA OVHD-N-E-S CLR SKY DSNT SW-NW VSBY NW 70 PK WND 3328/12/ WND 30V03 WND GRDLY VEERING/ 8/840/ 50000 10044 20025 WEATHER SUMMARY FOR MONDAY, MARCH 23, 2009 TEMPERATURE (DEGREES F) MAX.....32 NORMAL.....47 MIN.....18 NORMAL.....30 MEAN....25 NORMAL.....38 DEPARTURE FROM 30-YEAR NORMAL.................-13 TOTAL DEPARTURE FOR THE MONTH.................-13 [-0.8 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............40 DEPARTURE........+13 TOTAL HEATING UNITS FOR THE MONTH............702 DEPARTURE.........+9 TOTAL HEATING UNITS FOR THE SEASON..........5229 DEPARTURE........-34 TOTAL HEATING UNITS LAST SEASON TO DATE.....4910 DIFFERENCE......+319 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............38 NW AT 8:22 P.M. AEROVANE.............38 NW AT 8:22 P.M. ASOS.................40 NNW AT 7:01 P.M. DAVIS................40 WNW AT 8:21 P.M. FASTEST MILE FOR YESTERDAY..............28 NW AT 8:22 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........29 NW AT 8:23 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........31 NW AT 8:23 P.M. AVERAGE............16.9 WNW ASOS...............15.7 DAVIS..............16.6 WNW [300 DEGREES] 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...........2.45 DEPARTURE.........-1.10 ASOS...............2.39 TOTAL PRECIPITATION FOR THE YEAR............8.98 DEPARTURE.........-3.41 ASOS..............10.01 # # Includes erroneous ASOS precipitation data on 1/1/09, 1/2/09 and 2/27/09. SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.........-0.3 TOTAL SNOWFALL FOR THE MONTH...............13.4 DEPARTURE.........+3.9 TOTAL SNOWFALL FOR THE SEASON..............78.7 DEPARTURE........+23.8 PRELIMINARY CLIMATE SUMMARY FOR MARCH 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 3/1 28/21/25/-7/0.26/1.9/000/00 38 NNE 3/2 22/15/19/-13/1.21/8.2/000/00 40 NNE AERO 37 MPH NNE 3/3 25/11/18/-14/0.01/0.1/640/94 33 NW 3/4 30/6/18/-14/0/0/684/100 31 WNW 3/5 39/16/28/-5/0/0/659/96 25 WSW 3/6 49/30/40/+7/T/0/152/22 43 S AERO 41 MPH S 3/7 60/42/51/+18/0.06/0/429/62 37 S 3/8 57/42/50/+16/0/0/445/64 39 WNW AERO 40 MPH WNW 3/9 42/28/35/+1/0.72/3.2/000/00 33 N 3/10 42/26/34/0/0.02/0/470/67 23 SSE 3/11 50/33/42/+7/0.13/0/000/00 51 W 3/12 39/25/32/-3/0/0/685/97 44 W AERO 45 MPH W 3/13 37/19/28/-7/0/0/660/93 26 SSE 3/14 50/25/38/+2/0/0/613/86 24 SSW 3/15 59/34/47/+11/0/0/686/96 17 SSW 3/16 42/29/36/0/0/0/000/00 30 NE 3/17 47/28/38/0/+1/671/93 21 SSW 3/18 59/31/45/+8/0/0/448/62 37 SSW AERO 40 MPH S 3/19 45/36/41/+4/0.04/0/000/00 22 S 3/20 36/25/31/-7/0/0/.../.. 26 NNE 3/21 43/23/33/-5/0/0/.../.. 21 S 3/22 50/27/39/+1/0/0/.../.. 29 NW AERO 31 MPH WNW 3/23 32/18/25/-13/0/0/.../.. 38 NW 3/24 morning low temp. 18F; our normal low is now 30F NEW DAILY RECORDS FOR MARCH 2009... 3/2: DAILY SNOWFALL 8.2 INS. SURPASSES PREVIOUS RECORD OF 7.1 INS. IN 1948 3/7: DAILY MINIMUM 42 TIES RECORD HIGH MINIMUM FOR DATE PREVIOUSLY SET IN 1974 AND 1987 3/8: DAILY MINIMUM 42 TIES RECORD HIGH MINIMUM FOR DATE PREVIOUSLY SET IN 1995 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MARCH 24 HIGH 70 DEGREES IN 1920 LOW 6 DEGREES IN 1906 PRECIP 1.51 INS. IN 1956 SNOWFALL 12.3 INS. IN 1956 PEAK GUST 71 MPH W IN 1968 RECORDS FOR MARCH 25 HIGH 76 IN 1910 LOW 8 IN 1888, 1956 PRECIP 1.84 INS. IN 1909 SNOWFALL 1.0 INS. IN 1912 PEAK GUST 69 MPH SE IN 1969 TODAY'S REPORT PREPARED BY: Robert Skilling