BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, JANUARY 10, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME COLD AND DRY TODAY...CLOUDS ARE ADVANCING AS ANOTHER SNOW STORM MOVES IN TONIGHT... Very cold temperatures continue today with a morning low of 11 degrees before sunrise. The dew point has held in the middle single digits today, and visibility has climbed to 70 miles by early afternoon. Cirrus have been replaced by cirrostratus as the dominant cloud type at 1 P.M. with lower altostratus also visible, and both are beginning to obscure the sun for the day. Snow is approaching southwestern New England at early afternoon, and this will move into the area later this evening. 7 A.M. Weather: Thin scattered cirrus and thin broken cirrus Temperature: 12F, Dew point: 5F, Wind: W at 10 kts Sea-level pressure: 30.23 inches Hg, rising Visibility: 45 miles 6-hour minimum temperature: 11F Snow depth on ground: 3 inches BHO SA 1155 180 -SCT 250 -BKN 45 238/12/5/2610/023/ FEW AC FEW SC DSNT OFFSHR NE-ESE/ 8/131 4/003 53017 10016 20011 10 A.M. Weather: Thin broken cirrus Temperature: 18F, Dew point: 4F, Wind: WNW at 7 kts Sea-level pressure: 30.27 inches Hg, rising Visibility: 55 miles BHO SA 1455 250 –BKN 55 252/18/4/2807/027/ FEW LWR CI FEW AC SE-SSW FEW SC DSNT OFFSHR NE-E WND LGT/ 8/131 51014 1 P.M. Weather: Scattered altostratus, overcast cirrostratus, breaks in overcast distant NNW-E, sun dimly visible Temperature: 23F, Dew point: 5F, Wind: W at 6 kts Sea-level pressure: 30.24 inches Hg, falling Visibility: 70 miles 6-hour maximum temperature: 24F BHO SA 1755 180 SCT 200 OVC 70 239/23/5/2606/024/ FEW AC SE-SSW FEW BINOVC DSNT NNW-E SUN DMLY VSBL WND LGT/ 8/077 56013 10024 20011 WEATHER SUMMARY FOR FRIDAY, JANUARY 9 TEMPERATURE (DEGREES F) MAX.....25 NORMAL.....34 MIN.....16 NORMAL.....18 MEAN....21 NORMAL.....26 DEPARTURE FROM 30-YEAR NORMAL...............-5 TOTAL DEPARTURE FOR THE MONTH..............-16 [-2.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............44 DEPARTURE.........+5 TOTAL HEATING UNITS FOR THE MONTH............362 DEPARTURE........+17 TOTAL HEATING UNITS FOR THE SEASON..........2602 DEPARTURE........-72 TOTAL HEATING UNITS LAST SEASON TO DATE.....2453 DIFFERENCE......+149 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............37 W AT 4:13 P.M. * AEROVANE.............36 W AT 4:13 P.M. ASOS.................38 WNW AT 2:54 P.M. DAVIS................36 W AT 4:13 P.M. FASTEST MILE FOR YESTERDAY..............27 W AT 4:13 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........26 W AT 4:14 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........26 W AT 4:13 P.M. AVERAGE............18.2 W ASOS...............17.4 DAVIS..............16.8 W [268 deg] *last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.........-0.16 ASOS...............0.00 TOTAL PRECIPITATION FOR THE MONTH...........1.33 DEPARTURE.........-0.03 ASOS...............2.32 # TOTAL PRECIPITATION FOR THE YEAR............1.33 DEPARTURE.........-0.03 ASOS...............2.32 # # Includes erroneous ASOS precipitation data on 1/1/09 and 1/2/09 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE.........-0.5 TOTAL SNOWFALL FOR THE MONTH................0.9 DEPARTURE.........-3.6 TOTAL SNOWFALL FOR THE SEASON..............31.3 DEPARTURE........+13.2 PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2009 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 1/1 16/1/9/-18/0/0/538/98 44 WNW Aero 44 MPH WNW 1/2 32/9/21/-6/0/0/005/01 28 S 1/3 32/21/27/0/T/T/539/98 43 WNW Aero 44 MPH WNW 1/4 35/17/26/-1/0/0/512/93 36 W Aero 33 MPH W 1/5 36/26/31/+4/0.06/0/512/93 30 W 1/6 33/21/27/+1/0/0/183/33 27 W 1/7 36/26/31/+5/1.27/0.9/000/00 46 NE 1/8 38/21/30/+4/0/0/389/70 47 W 1/9 25/16/21/-5/0/0/.../.. 37 W 1/10 morning low temp: 11F; our normal low is now 18F NEW DAILY RECORDS FOR JANUARY 2009... ..NONE.. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JANUARY 10 HIGH 54F IN 2000 LOW -7F IN 2004 PRECIP 2.16 INS. IN 1935 SNOWFALL 6.3 INS. IN 1977 WIND 73e SE IN 1977 RECORDS FOR JANUARY 11 HIGH 59F IN 1975 LOW -7F IN 1968 PRECIP 1.14 INS. IN 1956 SNOW 10.2 INS. 1927 WIND 95e MPH S IN 1980 TODAY'S REPORT PREPARED By: Mike Iacono