BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, FEBRUARY 1, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME MUCH COLDER, A FEW FLURRIES, INCREASING CLOUDS; JANUARY FINISHES MUCH WARMER AND DRIER THAN AVERAGE Temperatures have turned sharply colder today after a strong cold front swept through yesterday morning just before 10 a.m. The high today struggled to reach the freezing mark. The dew point temperature has slid into the single digits this afternoon. The very dry air mass made for good visibility this afternoon, reaching 80 miles. Winds have been brisk today, gusting 30-40 mph at times, generally from the WSW-WNW. A few very light flurries were observed this morning, with a few snow showers visible to our distant W. Clouds have been increasing today as a storm system slides well to our S and E. January finished as the 7th driest on record. Despite the cold snap of more than 9 days below freezing, the month ended very much on the warm side. Additional stats are below, with more to come over the next few days. Driest Januarys, inches (1885-2012) 1) 0.89 in 1955 2) 0.97 in 1980 3) 1.00 in 1989 4) 1.07 in 1970 5) 1.25 in 1981 6) 1.31 in 1985 7) 1.42 in 2013 JANUARY 2013 PRELIMINARY STATISTICS: TEMPERATURE: Average Max Temp: 36.8F [+3.0F] Average Min Temp: 21.8F [+4.7F] Mean Temp: 29.3F [+3.8F] 24-hr. Corr. Mean Temp: 29.5F [+3.3F] Max Temp: 59F on 14th, 30th Min Temp: 0F on 24th Total heating degree day units (month): 1,097 [-129] *NCDC method Total heating degree day units (season): 3,125 [-406] *start July 1 (NCDC) PRECIPITATION: Total precipitation: 1.42 ins. [-2.93 ins.] Greatest 24-hr precipitation: 0.45 ins. on 16th, 30th/31st Total snowfall: 6.1 inches [-9.9 ins.] *using 1890-2010 mean Greatest snow depth: 4 ins. on 1st WIND: Avg wind speed: 13.6 MPH Avg corrected wind speed: 14.0 MPH Prevailing wind direction: WNW [23%] Peak gust: 74 MPH SSE on 31st Peak fastest mile: 62 MPH SSE on 31st Today's observations: 7 A.M. Weather: Scattered cumulus, scattered stratocumulus cumulogenitus, cumulus/stratocumulus distant all quadrants, few moderate cumulus tops, clear sky overhead, light distant haze, snow shower/virga distant WSW-WNW moving ESE Temperature: 24F; Dew Point: 10F; Wind: SW at 14G23 kts. Wind: Direction variable S-W Sea-level pressure: 29.72 ins. Hg, rising Visibility: 65 miles, light distant haze 24-hour precip: 0.03 in. 6-hour min. temp: 24F BHO SA 1155 40 SCT 50 SCT 65 065/24/10/2314G23/972/ CU/SC DSNT ALQDS FEW MDT TOPS CLR SKY OVHD LGT DSNT HZ SHSN/VIRGA DSNT WSW-WNW MOVG ESE WND 19V26/ 8/400 53024 MANUAL 70003 ASOS 70005 10028 20024 10 A.M. Weather: Scattered cumulus, scattered stratocumulus cumulogenitus, scattered altocumulus, scattered thin cirrus, few moderate cumulus, altocumulus ESE-WSW, cirrus distant E-S, clear sky overhead, snow shower distant SSW-WSW moving ESE, virga SE-SSE and NNW-N, light distant haze Temperature: 27F; Dew Point: 13F; Wind: W at 20G28 kts, Wind: Peak wind of 35 kts. from the WSW at 9:29 A.M. Wind: Direction variable SSW-W Wind: Direction gradually veering (clockwise) over the past hour Sea-level pressure: 29.78 ins. Hg, rising Visibility: 70 miles, light distant haze 3-hr precip: Trace 3-hr snowfall: Trace BHO SA 1455 40 SCT 50 SCT 65 SCT 250 –SCT 70 085/27/13/2620G28/978/ FEW MDT CU FEW AC ESE-WSW CI DSNT E-S CLR SKY OVHD SHSN DSNT SSW-WSW MOVG ESE VIRGA SE-SSE AND NNW-N LGT DSNT HZ PK WND 2535/29 WND 21V27 WND GRDLY VEERING PST HR/ 8/431 50020 MANUAL 6000/ 1 P.M. Weather: Scattered cumulus, scattered stratocumulus cumulogenitus, scattered cirrostratus, scattered dense cirrus, broken thin cirrus, few moderate cumulus WNW-N, stratocumulus cumulogenitus distant W-NW, patches of dense cirrus WSW-N, cirrostratus layer E-S-SW invading the sky, partial halo, virga distant W-NW, light distant haze Temperature: 31F; Dew Point: 7F; Wind: WNW at 11G21 kts, Wind: Peak wind of 30 kts. from the W at 12:34 P.M. Wind: Direction variable WSW-NNW Sea-level pressure: 29.75 ins. Hg, falling Visibility: 80 miles, light distant haze 6-hr precip: Trace 6-hr snowfall: Trace 6-hr max temp: 32F BHO SA 1755 50 SCT 60 SCT 200 SCT 220 SCT 250 –BKN 80 076/31/7/2911G21/975/ FEW MDT CU WNW-N SCCG DSNT W-NW PTCHS DNS CI WSW-N CS LYR E-S-SW INVADING PARTIAL HALO VIRGA DSNT W-NW LGT DSNT HZ PK WND 2830/34 WND 25V33/ 8/406 58009 MANUAL 6000/ 10032 20024 WEATHER SUMMARY FOR THURSDAY, JANUARY 31 TEMPERATURE (DEGREES F) MAX.....58 NORMAL.....34 MIN.....29 NORMAL.....17 MEAN....44 NORMAL.....26 DEPARTURE FROM 30-YEAR NORMAL.....................+18 TOTAL DEPARTURE FOR THE MONTH....................+130 [+4.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............21 DEPARTURE.........-18 TOTAL HEATING UNITS FOR THE MONTH..........1097 DEPARTURE........-129 TOTAL HEATING UNITS FOR THE SEASON.........3125 DEPARTURE........-406 TOTAL HEATING UNITS LAST SEASON TO DATE....2781 DIFFERENCE.......+344 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............74 SSE AT 6:22 A.M. AERO....................81 SSE AT 6:22 A.M. ASOS....................81 S AT 6:23 A.M. DAVIS...................77 S AT 4:42 A.M. RMY N/A THE FASTEST MILE FOR YESTERDAY.............62 SSE AT 6:04 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............58 S AT 5:34 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............56 S AT 5:35 A.M. AVERAGE WIND SPEED AND DIRECTION..........30.9 WSW ASOS...................29.3 DAVIS..................26.9 SW [226 deg.] * last of several occurrences. PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.03 DEPARTURE..........-0.10 ASOS..............0.05 TOTAL PRECIPITATION FOR THE MONTH..........1.42 DEPARTURE..........-2.93 ASOS..............1.48 TOTAL PRECIPITATION FOR THE YEAR...........1.42 DEPARTURE..........-2.93 ASOS..............1.48 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE............-0.5 TOTAL SNOWFALL FOR THE MONTH...............6.1 DEPARTURE...........-11.0 TOTAL SNOWFALL FOR THE SEASON.............21.5 DEPARTURE...........-11.6 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2013 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust RMY: RMY = R.M. Young wind gust recording system added 8/9/2011 TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 1/1 35/18/27/0/0.00/0.0/313/57 44 WNW AERO 44 MPH WNW RMY 45 1/2 29/11/20/-7/0.00/0.0/457/83 35 WNW AERO 35 MPH WNW RMY 33 1/3 23/2/13/-13/0.00/0.0/529/96 24 WNW AERO 23 MPH WNW RMY 23 1/4 38/19/29/+3/0.00/0.0/320/58 35 W AERO 36 MPH W RMY 36 1/5 40/27/34/+8/0.00/0.0/536/97 36 WNW AERO 37 MPH WNW RMY 38 1/6 42/27/35/+9/T/0.1/471/85 29 SW AERO 29 MPH SW RMY 29 1/7 38/27/33/+7/0.00/0.0/538/97 29 NW AERO 27 MPH NW RMY N/A 1/8 45/27/36/+10/0.00/0.0/428/77 39 SW AERO 42 MPH SW RMY 41 1/9 42/31/37/+11/T/0.0/033/06 40 W AERO 39 MPH W RMY N/A 1/10 45/32/39/+14/0.00/0.0/548/98 47 WNW AERO 48 MPH WNW RMY 50 1/11 38/29/34/+9/0.15/0.0/050/09 23 SE AERO 21 MPH SE RMY 23 1/12 43/35/40/+15/0.02/0.0/000/00 21 SE AERO 18 MPH SE RMY 15 1/13 50/41/46/+21/0.01/0.0/000/00 30 SW AERO 30 MPH SW RMY N/A 1/14 59/40/50/+25/T/0.0/175/31 36 S AERO 37 MPH S RMY 39 1/15 40/33/37/+12/T/0.0/045/08 17 N AERO 16 MPH NNW RMY 17 1/16 33/29/31/+6/0.45/3.5/000/00 16 NNE AERO 14 MPH N RMY 15 1/17 39/28/34/+9/0.00/0.0/519/91 36 WNW AERO 35 MPH WNW RMY 32 1/18 28/16/22/-3/0.00/0.0/566/99 39 NW AERO 39 MPH NW RMY 43 1/19 47/21/34/+9/0.00/0.0/350/61 46 SSW AERO 45 MPH SSW RMY 48 1/20 52/26/39/+14/0.00/0.0/408/71 48 SW AERO 52 MPH SW RMY 51 1/21 26/18/22/-3/0.06/0.9/144/25 35 WNW AERO 32 MPH WNW RMY N/A 1/22 23/10/17/-8/T/T/544/94 35 WNW AERO 30 MPH WNW RMY 35 1/23 15/4/10/-15/0.00/0.0/569/98 39 W AERO 35 MPH W RMY 37 1/24 17/0/9/-16/0.00/0.0/583/100 43 WNW AERO 39 MPH WNW RMY 44 1/25 22/4/13/-12/0.05/0.6/386/66 33 WNW AERO 27 MPH WNW RMY 32 1/26 23/9/16/-9/0.01/0.1/488/83 35 WNW AERO 31 MPH WNW RMY 33 1/27 29/9/19/-6/0.00/0.0/590/100 32 NW AERO 28 MPH NW RMY 31 1/28 29/17/23/-2/0.16/0.9/000/00 20 WNW AERO 14 MPH WNW RMY N/A 1/29 33/25/29/+4/0.06/0.0/000/00 17 SSE AERO 14 MPH SSE RMY N/A 1/30 59/33/46/+20/0.08/0.0/006/01 50 SSW AERO 48 MPH SSW RMY N/A 1/31 58/29/44/+18/0.37/0.0/.../.. 74 SSE AERO 81 MPH SSE RMY N/A 2/1 morning low temp: 24F; the normal low is now 17F DAILY RECORDS FOR JANUARY 2013 1/31 - TIED DAILY RECORD MAXIMUM TEMPERATURE OF 58F; ties the record of 58F in 1913, 1947 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR FEBRUARY 1 HIGH 65F IN 1989 LOW -9F IN 1920 PRECIP 1.30 INS. IN 1898 SNOWFALL 11.0 INS. IN 1898 PEAK GUST 66e MPH SSW IN 1951 RECORDS FOR FEBRUARY 2 HIGH 55F IN 1951, 1973 LOW -12F IN 1961 PRECIP 1.91 INS. IN 1999 SNOWFALL 5.5 INS. IN 1916, 1934 PEAK GUST 92 MPH SW IN 1970 TODAY'S REPORT PREPARED BY: Sean Fankhauser