BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, JANUARY 11, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME CALM, CLOUDY AND MILD The morning started with a temperature inversion across the area, as noted by the following low temperatures: Blue Hill 29F, Hingham 25F, Norwood, 20F. A strong area of high pressure overhead provided the conditions for cool air to pool in those low-elevation locations. These temperatures are still on the warm side for this time of the year, and, in fact, the average temperature for today on the summit is running close to 10 degrees above normal. That same area of high pressure has provided for very calm conditions today, too. Winds have been light, especially this afternoon. The hourly wind speed has averaged about 4 mph from 10 AM to 1 PM. As the center of the high is shifting slowly to our east, the wind direction has gradually veered (clockwise) throughout the day, from a NNW direction this morning to a general S direction this afternoon. An extensive, invading layer of mid and high level clouds has kept sunshine to a minimum today. Moisture and, consequently, haze have been on the increase today, too. Today's observations: 7 A.M. Weather: Scattered altocumulus, broken altostratus, broken cirrus, lower altocumulus/altocumulus lenticularis ESE-S-W, thin smoke layer along horizon all quadrants except ENE-SE, light distant haze, inversion present Temperature: 30F; Dew Point: 24F; Wind: N at 9 kts, Sea-level pressure: 30.50 ins. Hg, rising Visibility: 60 miles, light distant haze Snow depth: 1 inch 6-hr min. temp: 29F BHO SA 1155 120 SCT E160 BKN 250 BKN 60 327/30/24/0109/050/ LWR AC/ACSL ESE-S-W THN K LYR ALG HRZN ALQDS XCPT ENE-SE LGT DSNT HZ INVSN PRSNT/ 8/071 4/001 53007 10031 20029 10 A.M. Weather: Scattered altocumulus, scattered altostratus, broken cirrostratus, broken cirrus, lower altocumulus/altocumulus lenticularis distant SSE-SW-WNW, altostratus SE-SW-NW, thin smoke layer along horizon all quadrants, dark smoke layer along horizon NW-NNE, distant haze Temperature: 37F; Dew Point: 27F; Wind: E at 3 kts, Wind: Direction gradually veering (clockwise) over the past hour Wind: Light Sea-level pressure: 30.50 ins. Hg, rising then falling Visibility: 60 miles, E-SW 50 miles, NW 70 miles above inversion, distant haze BHO SA 1455 120 SCT 160 SCT E200 BKN 250 BKN 60 328/37/27/0903/050/ LWR AC/ACSL DSNT SSE-SW-WNW AS SE-SW-NW THN K LYR ALG HRZN ALQDS DRK K LYR ALG HRZN NW-NNE DSNT HZ VSBY E-SW 50 NW 70 ABV INVSN WND GRDLY VEERING PST HR WND LGT/ 8/077 50001 1 P.M. Weather: Broken altocumulus, broken altostratus, overcast cirrostratus, small cumulus fractus over the city to the N and to the ENE, few small cumulus along/offshore distant NE-ENE, sun dimly visible, distant haze, virga NW-NE and SE and in the vicinity of the station, smoke layer distant W-NNE Temperature: 37F; Dew Point: 29F; Wind: Estimated SSW at 2 kts, Wind: Light and variable Sea-level pressure: 30.42 ins. Hg, falling Visibility: 50 miles, distant haze 6-hour max: 38F BHO SA 1755 E140 BKN 160 BKN 200 OVC 50 300/37/29/E2002/042/ SML CUFRA OVR CTY N AND ENE FEW SML CU ALG/OFFSHR DSNT NE-ENE SUN DMLY VSBL DSNT HZ VIRGA NW-NE AND SE AND VCTY STN K LYR DSNT W-NNE WND LGT AND VRB/ 8/177 56028 10038 20030 WEATHER SUMMARY FOR THURSDAY, JANUARY 10 TEMPERATURE (DEGREES F) MAX.....45 NORMAL.....34 MIN.....32 NORMAL.....17 MEAN....39 NORMAL.....25 DEPARTURE FROM 30-YEAR NORMAL......................+14 TOTAL DEPARTURE FOR THE MONTH......................+42 [+4.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............26 DEPARTURE.........-14 TOTAL HEATING UNITS FOR THE MONTH...........347 DEPARTURE.........-42 TOTAL HEATING UNITS FOR THE SEASON.........2375 DEPARTURE........-318 TOTAL HEATING UNITS LAST SEASON TO DATE....2070 DIFFERENCE.......+305 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............47 WNW AT 3:27 A.M. AERO....................48 WNW AT 2:43 A.M. ASOS....................48 WNW AT 3:26 A.M. DAVIS...................49 W AT 3:27 A.M. RMY 50 THE FASTEST MILE FOR YESTERDAY.............37 WNW AT 3:27 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE..............33 WNW AT 2:26 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............34 WNW AT 3:28 A.M. AVERAGE WIND SPEED AND DIRECTION.........17.7 WNW ASOS..................15.5 DAVIS.................15.4 NW [304 deg.] *last of several occurrences PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE..........-0.14 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH.........Trace DEPARTURE..........-1.42 ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR..........Trace DEPARTURE..........-1.42 ASOS..............0.00 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE............-0.5 TOTAL SNOWFALL FOR THE MONTH...............0.1 DEPARTURE............-5.5 TOTAL SNOWFALL FOR THE SEASON.............15.5 DEPARTURE............-6.2 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/.../.. 47 WNW AERO 48 MPH WNW RMY 50 1/11 morning low temp: 29F; 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 11 HIGH 59F IN 1975 LOW -7F IN 1968 PRECIP 1.58 INS. IN 2008 SNOW 10.2 INS. 1927 PEAK GUST 95e MPH S IN 1980 RECORDS FOR JANUARY 12 HIGH 57F IN 1913, 1975 LOW -15F IN 1886 PRECIP 2.04 INS. IN 2011 SNOW 18.2 INS. IN 2011 WIND 84e MPH S IN 1980 TODAY'S REPORT PREPARED BY: Sean Fankhauser