BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, JANUARY 13, 2012 ALL TIMES ARE IN EASTERN STANDARD TIME STORM TOTAL RAINFALL REACHES 1.43 INCHES; WINDS INCREASE DRAMATICALLY TO A PEAK GUST OF 63 MPH; HIGH TEMPERATURE REACHES 50F TODAY Rain that began yesterday morning, becoming heavy at times, and ending late this morning with a few passing light rain showers has provided 1.43 inches of total rainfall. In fact, some light freezing drizzle appears to have occurred late last night and very early this morning as temperatures briefly dipped below freezing on the summit. The morning began with fairly light winds and the summit shrouded in fog, reducing visibility to 1/8 of a mile. Conditions began rapidly improving shortly before the 10 AM observation, with the fog quickly dissipating and extensive cloud cover dissipating as well. Winds began picking up dramatically after 11AM, reaching a peak gust of 63 mph on our official gust recorder shortly after 12PM. Some of our other wind systems recorded peak gusts in the 65-70 mph range. The wind direction has gradually veered from NE this morning to SW this afternoon as an area of low pressure and attendant frontal boundary move through the region. The high temperature reached 50F late this morning before a somewhat cooler and much drier air mass began invading the region. Today's temperatures are running 10-15 degrees above average. A much colder air mass will be in place this weekend. Today's observations: 7 A.M. Weather: Sky obscurred by dense fog and light drizzle, stratus drifting over summit, light drizzle continued very light and intermittent Temperature: 37F, Dew point: 37F, Wind: E at 15 kts, Sea-level pressure: 29.42 inches Hg, falling Visibility: 1/8 mile, dense fog and light drizzle 24-hour precip: 1.20 inches 6-hour min. temp: 31F BHO SA 1155 W3 X 1/8L-F 964/37/37/0915/942/ STRA DRFTNG OVR SMT L- CTD VRY LGT AND INTMNT/ 8//// 58034 MANUAL 70120 ASOS 7120 10037 20031 10 A.M. Weather: Scattered stratus, broken cumulus (2 levels), stratus drifting over summit, moderate cumulus all quadrants, thin fog/haze all quadrants, visibility increasing, light rain shower continued and ended at unknown time Temperature: 48F, Dew Point: 48F; Wind: SSE at 17G26 kts, Wind: Peak wind 27 kts from the SSE at 9:38 a.m. Sea-level pressure: 29.29 inches Hg, falling Visibility: 10 miles and increasing, thin fog/haze all quadrants 3-hour precip: 0.04 inch. BHO SA 1455 5 SCT 15 BKN 30 BKN 10 920/48/48/1617G26/929/ STRA DRFTNG OVR SMT MDT CU ALQDS THN FG/HZ ALQDS VSBY INCRSNG PK WND 1627/38 RW- CTD EUKN/ 8/300 56044 MANUAL 60004 ASOS 60005 1 P.M. Weather: Scattered cumulus, scattered altocumulus cumulogenitus, broken thin cirrus, few moderate cumulus all quadrants, cirrus distant ENE-SE, rain shower W-WNW and distant WNW-NW and distant NNW-NNE moving NE, light distant haze Temperature: 45F, Dew Point: 29F; Wind: SSW at 29G41 kts, Wind: Peak wind 55 kts from the SSW @ 12:05 P.M., Wind: Direction variable S-WSW, Sea-level pressure: 29.19 inches Hg, falling Visibility: 65 miles, light distant haze 6-hour max. temp: 50F 6-hour rainfall: 0.06 inch BHO SA 1755 40 SCT 60 SCT 250 –SCT 65 884/45/29/2129G41/919/ FEW MDT CU ALQDS CI DSNT ENE-SE SHRA W-WNW AND DSNT WNW-NW AND DSNT NNW-NNE MOVG NE LGT DSNT HZ PK WND 2155/05 WND 17V24 / 8/361 56036 MANUAL 60006 ASOS 60007 10050 20037 WEATHER SUMMARY FOR THURSDAY, JANUARY 12 TEMPERATURE (DEGREES F) MAX.....40 NORMAL.....34 MIN.....31 NORMAL.....17 MEAN....36 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL.....................+11 TOTAL DEPARTURE FOR THE MONTH.....................+91 [+7.4 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............29 DEPARTURE........-10 TOTAL HEATING UNITS FOR THE MONTH............378 DEPARTURE........-84 TOTAL HEATING UNITS FOR THE SEASON..........2131 DEPARTURE.......-660 TOTAL HEATING UNITS LAST SEASON TO DATE.....2676 DIFFERENCE......-545 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............52 ENE AT 9:38 A.M. AERO..................52 NE AT 12:52 P.M. ASOS..................52 E AT 9:39 A.M. DAVIS.................47 NE AT 12:50 P.M. RMY 49 THE FASTEST MILE FOR YESTERDAY...........35 ENE AT 11:53 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............36 ENE AT 11:53 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........34 ENE AT 11:53 A.M. AVERAGE WIND SPEED AND DIRECTION.......19.2 ENE ASOS................17.8 DAVIS...............16.8 ENE [059 deg.] *Last of several occurrences. PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....1.20 DEPARTURE..........+1.06 ASOS..............1.20 TOTAL PRECIPITATION FOR THE MONTH..........1.46 DEPARTURE..........-0.24 ASOS..............1.46 TOTAL PRECIPITATION FOR THE YEAR...........1.46 DEPARTURE..........-0.24 ASOS...............1.46 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M........Trace DEPARTURE..........-0.5 TOTAL SNOWFALL FOR THE MONTH................0.7 DEPARTURE..........-5.3 TOTAL SNOWFALL FOR THE SEASON...............9.2 DEPARTURE.........-10.4 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/.../.. 22 S AERO 21 MPH S RMY 24 1/10 43/28/36/+11/0.05/0.5/.../.. 29 WNW AERO 30 MPH WNW RMY 32 1/11 38/27/33/+8/0.00/0.0/.../.. 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 our morning low temp: 31F; the normal low is 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 13 HIGH 57F IN 1890,1932 LOW -10F IN 1912,1914 PRECIP 1.54 INS. IN 1979 SNOWFALL 12.6 INS. IN 1964 PEAK GUST 74 MPH NE IN 1964 RECORDS FOR JANUARY 14 HIGH 65F IN 1995 LOW -12F IN 1914 PRECIP 1.45 INS. IN 2008 SNOWFALL 10.3 INS. IN 2008 PEAK GUST 68 MPH WNW IN 1976, S IN 2005 TODAY'S REPORT PREPARED BY: Sean Fankhauser