BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA   DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, JANUARY 29, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME   MORE ARCTIC AIR RETURNED TODAY AFTER A BRIEFLY MILDER DAY YESTERDAY   Colder and drier air has been arriving this morning with dewpoint temperatures dropping down to near zero. Yesterday was only the third day during the past twelve to average milder than normal.   During the first 16 days of the month we averaged 12 degrees warmer than normal but during the past 12 days the average is 5 degrees colder than normal. The result is that January is now averaging just over 5 degrees warmer than normal. Today's observations:   7 A.M.   Weather: Broken clouds, clearing from west Temperature: 21F, Dew point: 11F, Wind: WNW at 13G21 kts Sea-level pressure: 29.67 inches Hg, rising Visibility: 35 miles 6-hourly min. temp. 21 deg. 6-hourly precip: trace 24-hourly snowfall: trace BHO SA 1155 E40 BKN 85 BKN 35 048/21/11/3013G21/967/ FEW ACSL SW-NW SKY CLRG FRM W SBEUKN/ 8/540 53019 MANUAL 6000/ 10026 20021   10 A.M.    Weather: Clear, few clouds, low, middle and high NE-SE Temperature: 21F, Dew point: 05F, Wind: WNW at 13 kts Wind: direction variable W-NW Sea-level pressure: 29.69 inches Hg, rising      Visibility: 55 miles BHO SA 1455 CLR 55 072/21/5/3013/974/ FEW SC CUFRM TOPS NE-ESE ALG SHR FEW ACSL NE-SE AND FEW CI NE-S WND 26V32/ 8/541 53024   1 P.M.    Weather: Clear, few cumulus, stratocumulus layer offshore   Temperature: 24F, Dew point: 03F, Wind: WNW at 16G20 kts Sea-level pressure: 29.69 inches Hg, rising      Visibility: 60 miles 6-hourly max. temp. 25 deg.  BHO SA 1755 CLR 60 068/24/3/2916G20/973/ FEW SML CUFRA/CU SC LYR CUFRM TOPS OFFSHR DSNT NE-ESE FEW ACSL NW-NE WND 25V31/ 8/840 58004 10025 20019      WEATHER SUMMARY FOR SUNDAY, JANUARY 28    TEMPERATURE (DEGREES F) MAX.....37    NORMAL.....34 MIN.....23    NORMAL.....18   MEAN....30    NORMAL.....26   DEPARTURE FROM 30-YEAR NORMAL........+ 4 TOTAL DEPARTURE FOR THE MONTH.......+152 (+5.2 DEGREES/DAY)   HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY..........35   DEPARTURE......- 4 TOTAL HEATING UNITS FOR THE MONTH.........943   DEPARTURE.....-150 TOTAL HEATING UNITS FOR THE SEASON.......2816   DEPARTURE.....-603 TOTAL HEATING UNITS LAST SEASON TO DATE..3009   DIFFERENCE....-193   PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............21   W AT  8:52 A.M. *                    AEROVANE.............21   W AT  8:52 A.M.                     ASOS.................18   W AT  8:51 A.M.                    DAVIS................21   W AT  8:50 A.M.  FASTEST MILE FOR YESTERDAY..............15   W AT  8:03 A.M.   MAXIMUM 2-MINUTE ASOS AVERAGE...........16   W AT  8:05 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........16 WSW AT  8:02 A.M.  AVERAGE WIND SPEED AND DIRECTION...... 7.8  W                     ASOS.............. 8.4                           DAVIS............. 7.8  NW [310 deg]  * last of several occurrences   PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...trace  DEPARTURE.....-0.15                          ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........2.91  DEPARTURE.....-1.42                           ASOS..............2.84    TOTAL PRECIPITATION FOR THE YEAR...........2.91  DEPARTURE.....-1.42                           ASOS..............2.84   SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........trace DEPARTURE......-0.5 TOTAL SNOWFALL FOR THE MONTH................1.9  DEPARTURE.....-12.1 TOTAL SNOWFALL FOR THE SEASON...............5.6  DEPARTURE.....-22.0   PRELIMINARY CLIMATE SUMMARY FOR JANUARY 2007......CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST   AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available   1/1  53/30/42/+15/0.98/0/000/00     38 SE 1/2  43/31/37/+10/0.03/0/505/92     44 W    Aero 47 MPH W   1/3  49/30/40/+13/0/0/435/79        40 S   1/4  53/40/47/+20/0/0/198/36        31 SSW 1/5  61/46/54/+27/0.04/0/000/00     44 S    Aero 44 MPH S 1/6  66/48/57/+31/0.03/0/161/29     48 SSW  Aero 47 MPH SSW 1/7  50/38/44/+18/0/0/505/91        43 W    Aero 44 MPH W 1/8  52/36/44/+18/0.69/0/000/00     45 W    Aero 45 MPH W 1/9  41/29/35/+9/0/0/518/93         40 W    Aero 39 MPH W 1/10 34/22/28/+2/0/0/525/94         48 W 1/11 33/17/25/-1/0/0/336/60         36 S    Aero 38 MPH S 1/12 48/32/40/+14/0/0/168/30        38 SSW  Aero 39 MPH SSW 1/13 48/36/42/+16/0.06/000/00       30 S     1/14 38/31/35/+9/0.16/0/000/00      21 NE 1/15 40/31/36/+10/0.58/0/000/00     25 NNE 1/16 38/15/27/+1/0.05/0/000/00      40 W    Aero 42 MPH W 1/17 18/6/12/-14/0.00/0/563/99      38 WNW  Aero 43 MPH WNW 1/18 36/10/23/-3/0.13/0.1/171/30    33 SSE 1/19 38/30/34/+9/0.06/T/269/47      40 W    Aero 41 MPH W 1/20 30/12/21/-4/T/T/402/70         51 W    Aero 55 MPH WNW 1/21 24/9/17/-8/0/0/449/78          33 W 1/22 24/18/21/-4/0.05/1.0/000/00    16 WNW 1/23 30/18/24/-1/0.01/0.2/110/19    23 NW 1/24 38/22/30/+4/0/0/448/77         30 W 1/25 26/6/16/-10/T/T/356/61         30 NW  1/26 11/-1/5/-21/0/0/563/96         38 WNW  Aero 39 MPH WNW 1/27 25/2/14/-12/T/T/000/00         23 W 1/28 37/23/30/+4/0.04/0.6/408/69    21 W    1/29 morning low temp. 21; normal now 18 deg.       a trace of snow and precip. 6 a.m. to 7 a.m.        DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR JANUARY 29 HIGH 66F IN 2002 LOW -11F IN 1888 PRECIP 1.48 INS. IN 1973 SNOWFALL 8.0 INS. IN 1943 PEAK GUST 72 MPH NW IN 1973   RECORDS FOR JANUARY 30 HIGH 60F IN 1914 LOW -8F IN 1948 PRECIP 1.12 INS. IN 1925 SNOWFALL 6.5 INS. IN 1986 PEAK GUST 76 MPH WNW IN 1962   TODAY'S REPORT By: Robert Skilling   If you do not wish to receive this Daily Discussion and Climate Summary from the Blue Hill Observatory, please send an email to sitemaster@bluehill.org.