BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, JANUARY 18, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME WINTER'S CHILL FINALLY RETURNS; BREEZY AT TIMES TODAY Temperatures have dropped steadily since yesterday afternoon, bottoming out on the summit at 16F between 7 and 8 a.m. this morning. Temperatures have struggled to reach the lower 20s this afternoon, however the high for the day of 28F occurred just after midnight this morning. Today's cold will put an end to a 2 week streak of above normal temperatures. The recent warm spell has pushed the January average temperature 8 degrees above the 30 year normal! Winds have been strong at times today. A brief spell of strong winds this afternoon peaked at 39 mph. The strong WNW-NW winds have pushed the wind chill into the single digits, and at times even lower than that. Ice extent on Ponkapoag Pond has been reduced further overnight due to the strong winds. It's assessment today has been a generous 1 tenth of ice coverage. Houghton's pond remains at 7 tenths. Today's observations: 7 A.M. Weather: Scattered altocumulus, scattered cirrus, cumulus/stratocumulus layer with a few moderate tops distant NE-ESE, altocumulus distant NE-SE-WSW, few altocumulus lenticularis distant ESE-SSW, clear sky W-NNE Temperature: 17F; Dew Point: 0F; Wind: WNW at 9 kts, Wind: Direction variable WNW-N Sea-level pressure: 30.21 ins. Hg, rising Visibility: 65 miles Snow depth: 1 inch 6-hour min temp: 17F BHO SA 1155 80 SCT 250 SCT 65 230/17/0/3309/021/ CU/SC LYR FEW MDT TOPS DSNT NE-ESE AC DSNT NE-SE-WSW FEW ACSL DSNT ESE-SSW CLR SKY W-NNE WND 30V01/ 8/541 4/001 52034 10027 20017 10 A.M. Weather: Clear, few cumulus/stratocumulus along/offshore distant NE-S, light distant haze Temperature: 18F; Dew Point: -2F; Wind: WNW at 11 kts, Wind: Direction variable W-N Sea-level pressure: 30.32 ins. Hg, rising Visibility: 75 miles, light distant haze BHO SA 1455 CLR 75 268/18/-2/3311/032/ FEW CU/SC ALG/OFFSHR DSNT NE-S LGT DSNT HZ WND 28V01/ 8/500 51038 1 P.M. Weather: Clear, cumulus/cumulus fractus distant NNE-SE-SSW, few small cumulus fractus SW-NNW Temperature: 21F; Dew Point: 2F; Wind: WNW at 17G26 kts, Wind: Peak wind of 31 kts. from the WNW at 12:33 P.M. Wind: Direction variable W-NNW Sea-level pressure: 30.33 ins. Hg, rising slightly Visibility: 80 miles 6-hour max temp: 21F 6-hour min temp: 16F BHO SA 1755 CLR 80 270/21/2/3017G26/033/ CU/CUFRA DSNT NNE-SE-SSW FEW SML CUFRA SW-NNW PK WND 2931/33 WND 26V34/ 8/100 50002 10023 20016 WEATHER SUMMARY FOR THURSDAY, JANUARY 17 TEMPERATURE (DEGREES F) MAX.....39 NORMAL.....33 MIN.....28 NORMAL.....17 MEAN....34 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL.......................+9 TOTAL DEPARTURE FOR THE MONTH.....................+139 [+8.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............31 DEPARTURE..........-9 TOTAL HEATING UNITS FOR THE MONTH...........530 DEPARTURE........-138 TOTAL HEATING UNITS FOR THE SEASON.........2558 DEPARTURE........-414 TOTAL HEATING UNITS LAST SEASON TO DATE....2325 DIFFERENCE.......+233 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............36 WNW AT 1:17 P.M. AERO....................35 WNW AT 1:17 P.M. ASOS....................35 W AT 1:17 P.M. DAVIS...................32 W AT 1:17 P.M. RMY 32 THE FASTEST MILE FOR YESTERDAY.............25 WNW AT 1:26 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............24 W AT 1:18 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............21 W AT 1:19 P.M. AVERAGE WIND SPEED AND DIRECTION.........10.3 WSW ASOS..................10.1 DAVIS..................7.7 WNW ** [284 deg.] ** Davis anemometer slowed by glaze accumulation PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M... 0.00 DEPARTURE..........-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........0.63 DEPARTURE..........-1.80 ASOS..............0.60 TOTAL PRECIPITATION FOR THE YEAR...........0.63 DEPARTURE..........-1.80 ASOS..............0.60 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE............-0.6 TOTAL SNOWFALL FOR THE MONTH...............3.6 DEPARTURE............-6.0 TOTAL SNOWFALL FOR THE SEASON.............19.0 DEPARTURE............-6.6 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 N/A 1/14 59/40/50/+25/T/0.0/175/41 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/.../.. 36 WNW AERO 35 MPH WNW RMY 32 1/18 morning low temp: 17F; the normal low is now 17F DAILY RECORDS FOR JANUARY 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 18 HIGH 62F IN 1973,1990 LOW -10F IN 1982 PRECIP 1.68 INS. IN 1915 SNOWFALL 13.0 INS. IN 1948 PEAK GUST 85 MPH SSE IN 2006 RECORDS FOR JANUARY 19 HIGH 59F IN 1973 LOW -11F IN 1887 PRECIP 2.34 INS. IN 1936 SNOWFALL 10.5 INS. IN 1936 PEAK GUST 93e MPH WNW IN 1943 TODAY'S REPORT PREPARED BY: Sean Fankhauser