BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, DECEMBER 13, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME COLD - SINGLE DIGIT WIND CHILL THIS MORNING With a high of 23F and a low of 14F, yesterday's average temperature was 14 degrees below the 30-year normal for the date. The cold continues today. The morning started at 14F, and temperatures have managed to warm slightly more than yesterday, reaching 27F this afternoon. Today's SW wind has helped push the temperature a little higher compared to yesterday. Winds today have been brisk in the 15-25 mph range, with occasional gusts near 30 mph. That pushed wind chill values this morning down near zero. Wind chill values this afternoon are in the 10-15F range, so it certainly feels quite cold. We have now seen 6 consecutive days below normal. With the recent cold, the average temperature for the month is now more than a degree more normal. Today's Observations: 7 A.M. Weather: Scattered altocumulus, scattered thin cirrus, few cumulus/ stratocumulus along/offshore distant ENE-SSE, altocumulus/altocumulus lenticularis mostly SE-WNW, few altocumulus distant ENE-SE, cirrus E-S, light haze Temperature: 16F; Dew Point: 8F; Wind: WSW at 14G21 kts, Wind: Direction variable SSW-W Sea-level pressure: 30.02 ins. Hg, rising then rising more slowly Visibility: 50 miles, light haze Snow depth: 1 inch 6-hr. min temp: 14F BHO SA 1155 90 SCT 250 –SCT 50 165/16/8/2414G21/002/ FEW CU/SC ALG/OFFSHR DSNT ENE-SSE AC/ACSL MSTLY SE-WNW FEW AC DSNT ENE-SE CI E-S LGT HZ WND 20V27/ 8/541 4/001 50004 10016 20014 10 A.M. Weather: Scattered altocumulus, few cumulus distant N-E and distant W-NNW, altocumulus/altocumulus lenticularis distant SE-WSW and distant WNW-NNW, distant haze Temperature: 23F; Dew Point: 10F; Wind: WSW at 15G24 kts, Peak wind: 26 kts. from the WSW at 9:16 A.M. EST Wind: Direction SSW-W Sea-level pressure: 30.06 ins. Hg, rising then rising more slowly Visibility: 40 miles, distant haze BHO SA 1455 90 SCT 40 181/23/10/2415G24/006/ FEW CU DSNT NE-E AND DSNT W-NNW AC/ACSL DSNT SE-WSW AND DSNT WNW-NNW DSNT HZ PK WND 2526/16 WND 20V28/ 8/140 51016 1 P.M. Weather: Broken cumulus/stratocumulus, broken stratocumulus cumulogenitus, broken altocumulus, few moderate cumulus all quadrants, altocumulus/ altocumulus lenticularis distant SE-SW, hazy, snow shower/virga NW-NNE moving ESE Temperature: 26F; Dew Point: 13F; Wind: W at 13G22 kts, Wind: Direction variable SW-WNW Sea-level pressure: 30.03 ins. Hg, falling then falling more slowly Visibility: 40 miles, hazy 6-hr max. temp. 27F BHO SA 1755 E35 BKN 45 BKN 140 BKN 40 171/26/13/2613G22/003/ FEW MDT CU ALQDS AC/ACSL DSNT SE-SW HAZY SHSN/VIRGA NW-NNE MOVG ESE WND 23V29/ 8/440 56010 10027 20016 WEATHER SUMMARY FOR THURSDAY, DECEMBER 12, 2013 TEMPERATURE (DEGREES F) MAX.....23 NORMAL.....40 MIN.....14 NORMAL.....25 MEAN....19 NORMAL.....33 DEPARTURE FROM 30-YEAR NORMAL.....................-14 TOTAL DEPARTURE FOR THE MONTH.....................-14 [-1.4 DEGREE/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY..............46 DEPARTURE........+13 TOTAL HEATING UNITS FOR THE MONTH.............379 DEPARTURE........+13 TOTAL HEATING UNITS FOR THE SEASON...........1603 DEPARTURE........-24 TOTAL HEATING UNITS LAST SEASON TO DATE......1440 DIFFERENCE......+163 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..................28 WNW AT 9:35 A.M. AERO.......................31 NW AT 11:03 A.M. ASOS.......................29 NW AT 10:58 A.M. DAVIS......................28 NW AT 11:03 A.M. RMY 30 FASTEST MILE FOR YESTERDAY....................22 NW AT 9:44 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.................22 NW AT 9:44 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE................21 WNW AT 9:37 A.M. AVERAGE WIND SPEED AND DIRECTION............11.4 WNW ASOS.....................11.8 DAVIS....................10.2 W [280 degrees] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE.............-0.17 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.29 DEPARTURE.............-0.69 ASOS..............1.26 TOTAL PRECIPITATION FOR THE YEAR..........47.89 DEPARTURE..............-2.62 ASOS..............N/A** ** ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.......0.0 DEPARTURE.............-0.4 TOTAL SNOWFALL FOR THE MONTH.............2.7 DEPARTURE.............-1.3 TOTAL SNOWFALL FOR THE SEASON............2.9 DEPARTURE.............-3.7 PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2013 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 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 12/1 45/30/38/+1/0.28/T/000/00 22 SSE AERO 23 MPH SSE RMY 23 12/2 38/34/36/0/T/0.0/000/00 15 NW AERO 15 MPH NW RMY 16 12/3 45/32/39/+3/0.00/0.0/284/51 18 NNW AERO 18 MPH NNW RMY 20 12/4 43/29/36/+1/0.00/0.0/389/70 21 WNW AERO 21 MPH WNW RMY 21 12/5 53/38/46/+11/0.02/0.0/000/00 36 S AERO 40 MPH S RMY 39 12/6 55/33/44/+9/0.38/T/000/00 25 SSW AERO 28 MPH SSW RMY N/A 12/7 40/26/33/-1/0.12/T/287/52 23 NW AERO 25 MPH NW RMY N/A 12/8 30/22/26/-8/T/T/039/07 25 NW AERO 27 MPH NW RMY N/A 12/9 41/25/33/-1/0.35/0.6/000/00 28 E AERO 28 MPH E RMY 24 12/10 33/21/27/-6/0.14/2.1/000/00 28 W AERO 28 MPH W RMY 28 12/11 28/19/24/-9/0.00/0.0/345/63 27 SW AERO 28 MPH SW RMY 27 12/12 23/14/19/-14/0.00/0.0/.../.. 28 WNW AERO 31 MPH NW RMY 30 12/13 morning low temp: 14F; the normal low is now 25F DAILY RECORDS FOR DECEMBER 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR DECEMBER 13 HIGH 60 IN 1984 LOW 0 IN 1893 PRECIP 1.45 INS. IN 1983 SNOWFALL 9.2 INS. IN 2007 PEAK GUST 81e WNW IN 1976 RECORDS FOR DECEMBER 14 HIGH 62 IN 1901 LOW -6 IN 1893 PRECIP 1.94 INS. IN 2002 SNOWFALL 8.0 INS. IN 1907 PEAK GUST 78e ENE IN 1941 TODAY'S REPORT PREPARED BY: Sean Fankhauser