BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, JANUARY 20, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME 1.8 INCHES OF SNOW OVERNIGHT; MOSTLY CLEAR BUT COLD TODAY Light snow that began Thursday night and ended early Friday morning accumulated to 1.8 inches of fluffy snow. The melted snow came out to 0.16 inch of liquid, so roughly a 1 to 11 liquid to snow ratio. Winds gusting late this morning and early this afternoon in the 20-30 mph range have caused some blowing and drifting of the snow on the ground. The 1.8 inches storm total is our largest snowfall of the winter season, although it would appear that the forecast for snowfall from tomorrow's system could surpass that. Our total snowfall since October is now in excess of one foot at 12.6 inches, but is still lagging 10.5 inches below normal. The sky has been mostly clear today with the exception of a few cumulus. Winds have become WNW, ushering in a colder, drier air mass. The temperature has struggled to reach the upper 20s this afternoon, after a mid-morning low temperature of 24F. Visibility has improved to 75 miles this afternoon as the drier air mass filters into the region. Dew point temperatures that were in the mid 20s this morning have fallen into the mid teens this afternoon. Today's observations: 7 A.M. Weather: Scattered cumulus, scattered altocumulus (2 levels), few lower cumulus/cumulus fractus distant NE-ESE, few cumulus/moderate cumulus distant WSW, lower altocumlus/altocumulus lenticularis distant SW-WNW, higher altocumulus distant ENE-SSW, steam fog over pond to the SE, thin fog/haze all quadrants Temperature: 25F, Dew point: 24F, Wind: W at 12 kts, Sea-level pressure: 29.97 inches Hg, rising Visibility: 20 miles, thin fog/haze all quadrants 24-hour snowfall: 1.8 inches Snow depth: 2 inches 24-hour precip: 0.16 inch 6-hour precip: 0.02 inch 6-hour min. temp: 24F BHO SA 1155 25 SCT 60 SCT 100 SCT 20 148/25/24/2712/997/ FEW LWR CU/CUFRA DSNT NE-ESE FEW CU/MDT CU DSNT WSW LWR AC/ACSL DSNT SW-WNW HIER AC DSNT ENE-SSW STEAM FG OVR PND SE THN FG/HZ ALQDS TOTAL NEW SNW PST 24 HRS 1.8 INS/ 8/270 4/002 53014 MANUAL 70017 ASOS 70015 MANUAL 60002 ASOS 60001 10029 20024 10 A.M. Weather: Scattered cumulus, scattered thin cirrus, cumulus/cumulus fractus distant all quadrants, few moderate cumulus distant WNW-NNW, few cirrus distant SE-SSW, light distant haze, occasional blowing/drifting of snow Temperature: 25F, Dew Point: 20F; Wind: WNW at 12G19 kts, Wind: Direction variable WSW-NW Sea-level pressure: 30.06 inches Hg, rising Visibility: 55 miles, light distant haze BHO SA 1455 35 SCT 250 –SCT 55 180/25/20/2912G19/006/ CU/CUFRA DSNT ALQDS FEW MDT CU DSNT WNW-NNW FEW CI DSNT SE-SSW OCNL BLWG/DRFTNG SNW LGT DSNT HZ WND 25V31/ 8/201 51032 1 P.M. Weather: Scattered cumulus, scattered thin cirrus, few small cumulus/ cumulus fractus all quadrants, cirrus distant S-SW, light distant haze, occasional blowing/drifting of snow Temperature: 27F, Dew Point: 16F; Wind: W at 17G26 kts Wind: Peak wind of 26 kts from the W at 12:46 PM Wind: Direction variable WSW-NW Sea-level pressure: 30.08 inches Hg, rising Visibility: 75 miles, light distant haze 6-hour max. temp: 28F BHO SA 1755 35 SCT 250 –SCT 75 186/27/16/2817G26/008/ FEW SML CU/CUFRA ALQDS CI DSNT S-SW LGT DSNT HZ OCNL BLWG/DRFTNG SNW PK WND 2726/46 WND 25V32/ 8/101 51006 10028 20024 WEATHER SUMMARY FOR THURSDAY, JANUARY 19 TEMPERATURE (DEGREES F) MAX.....28 NORMAL.....33 MIN.....12 NORMAL.....17 MEAN....20 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL......................-5 TOTAL DEPARTURE FOR THE MONTH....................+101 [+5.1 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............45 DEPARTURE.........+6 TOTAL HEATING UNITS FOR THE MONTH............648 DEPARTURE........-87 TOTAL HEATING UNITS FOR THE SEASON..........2401 DEPARTURE.......-663 TOTAL HEATING UNITS LAST SEASON TO DATE.....2974 DIFFERENCE......-573 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............27 SE AT 10:24 P.M. AERO..................28 ESE AT 9:53 P.M. ASOS..................26 SE AT 10:07 P.M. DAVIS.................25 SE AT 10:24 P.M. RMY 28 THE FASTEST MILE FOR YESTERDAY...........18 ESE AT 10:06 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............17 SE AT 10:25 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........17 SE AT 10:33 P.M. AVERAGE WIND SPEED AND DIRECTION........9.4 SE ASOS.................9.3 DAVIS................8.6 E [089 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.16 DEPARTURE..........+0.03 ASOS..............0.15 TOTAL PRECIPITATION FOR THE MONTH..........1.90 DEPARTURE..........-0.80 ASOS..............1.90 TOTAL PRECIPITATION FOR THE YEAR...........1.90 DEPARTURE..........-0.80 ASOS...............1.90 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........1.8 DEPARTURE..........+1.3 TOTAL SNOWFALL FOR THE MONTH................4.1 DEPARTURE..........-5.4 TOTAL SNOWFALL FOR THE SEASON..............12.6 DEPARTURE.........-10.5 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2012 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant 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 51/35/42/+16/0.01/0.0/494/90 35 S AERO 35 MPH S RMY 37 1/2 48/30/39/+12/0.02/T/346/63 36 W AERO 36 MPH W RMY 37 1/3 30/11/21/-5/0.00/0.0/446/81 39 NW AERO 38 MPH NW RMY 39 1/4 26/7/17/-9/0.00/0.0/468/85 28 NW AERO 25 MPH NW RMY N/A 1/5 35/20/28/+2/T/T/166/30 27 W AERO 25 MPH W RMY 26 1/6 47/23/35/+9/0.01/0.1/.../.. 26 S AERO 25 MPH S RMY 27 1/7 59/39/49/+23/0.00/0.0/477/86 29 WSW AERO 29 MPH SW RMY 30 1/8 43/26/35/+9/0.00/0.0/367/66 28 W AERO 27 MPH W RMY N/A 1/9 39/21/30/+4/0.00/0.0/384/69 22 S AERO 21 MPH S RMY 24 1/10 43/28/36/+11/0.05/0.5/379/68 29 WNW AERO 30 MPH WNW RMY 32 1/11 38/27/33/+8/0.00/0.0/448/80 24 E AERO 24 MPH E RMY N/A 1/12 40/31/36/+11/1.37/0.1/000/00 52 ENE AERO 52 MPH NE RMY 49 1/13 50/27/39/+14/0.06/T/174/31 63 SW AERO 67 MPH SW RMY 67 1/14 33/16/25/0/0.00/0.0/451/80 36 WSW AERO 37 MPH WSW RMY 35 1/15 16/4/10/-15/0.00/0.0/555/98 36 NW AERO 36 MPH NW RMY 37 1/16 31/5/18/-7/0.11/1.2/408/72 32 SSW AERO 32 MPH SSW RMY N/A 1/17 46/31/39/+14/0.11/0.4/000/00 35 SW AERO 36 MPH SW RMY N/A 1/18 49/18/34/+9/0.00/0.0/564/99 56 WNW AERO 55 MPH WNW RMY 56 1/19 28/12/20/-5/0.10/1.1/.../.. 27 SE AERO 28 MPH ESE RMY 28 1/20 the morning low temp: 24F; the normal low is now 17F DAILY RECORDS FOR JANUARY 2012 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 20 HIGH 59F IN 1951 LOW -9F IN 1901 PRECIP 1.95 INS. IN 1978 SNOWFALL 19.0 INS. IN 1978 [RECORD FOR MONTH] PEAK GUST 76e MPH NE IN 1978 RECORDS FOR JANUARY 21 HIGH 65F IN 1906 LOW -4F IN 1888,1893 PRECIP 2.49 INS. IN 1979 SNOWFALL 7.6 INS. IN 2011 PEAK GUST 78e MPH SE IN 1979 TODAY'S REPORT PREPARED BY: Sean Fankhauser