BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, FEBRUARY 13, 2007
ALL TIMES ARE IN EASTERN STANDARD TIME
 
ARCTIC AIR FRONTAL BOUNDARY PASSED JUST AFTER MIDNIGHT
TEMPERATURES DROP FROM 22 AT MIDNIGHT TO 6 DEGREES AT 7 A.M.
 
Very cold and very dry air was arriving early this morning 
with a 6-degree temperature drop from midnight to 1 a.m. as
WNW winds shifted to NNW-N.  Dewpoint temperatures had 
dropped close to 14 below zero later in the morning. 
High clouds thinned out to allow plenty of bright sunshine 
by noon with temperatures approaching only 20 degrees.
 
Today's observations:
 
7 A.M.   
Weather: High overcast, break NW-E   
Temperature: 6F, Dew point: -12F, Wind: WNW at 16G22 kts
Windchill: -13 deg.  
Sea-level pressure: 30.36 inches Hg, rising
Visibility: 70 miles 
Snow on ground: trace
6-hourly min. temp. 6 deg. 
BHO SA 1155 E250 OVC 70 282/6/-12/3016G22/036/ SC LYR CUFRM TOPS DSNT OFFSHR
NE-ESE AC LYR ALG HRZN DSNT SSE-SSW BINOVC/CLR SKY BND XTDNG DSNT NW-E 
SML BINOVC DSNT SSE-S WNDCHILL -13/ 8/537 53016 10016 20006
   
10 A.M.    
Weather: High overcast 
Temperature: 10F, Dew point: -13F, Wind: WNW at 12G24 kts
Sea-level pressure: 30.39 inches Hg, rising     
Visibility: 65 miles
BHO SA 1455 E250 OVC 65 290/10/-13/2912G24/039/ FEW AC DSNT SSE-S 
BINOVC DSNT N-E AND SML BINOVC DSNT SSE-S VSBY NW 70 WND 25V32/ 8/047 51008 
 
1 P.M.    
Weather: mid-high level cloudiness with dimmed sunshine  
Temperature: 19F, Dew point: -11F, Wind: WNW at 11G19 kts
Sea-level pressure: 30.34 ins. and falling      
Visibility: 65 miles, 70 NW 
6-hourly max. temp. 19 deg. 
BHO SA 1755 150 SCT 250 –BKN 300 –OVC 65 275/19/-11/3012G19/034/ 
VSBY NW 70/ 8/057 58015 10019 20006
 
 
WEATHER SUMMARY FOR MONDAY, FEBRUARY 12
 
TEMPERATURE (DEGREES F)
MAX.....36    NORMAL.....35 
MIN.....20    NORMAL.....20   
MEAN....28    NORMAL.....28
 
DEPARTURE FROM 30-YEAR NORMAL...........0 
TOTAL DEPARTURE FOR THE MONTH.........-63 (-5.5 DEGREES/DAY) 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY..........37   DEPARTURE.......- 1
TOTAL HEATING UNITS FOR THE MONTH.........522   DEPARTURE.......+60 
TOTAL HEATING UNITS FOR THE SEASON.......3466   DEPARTURE......-532
TOTAL HEATING UNITS LAST SEASON TO DATE..3493   DIFFERENCE......-27
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............43  WSW AT  4:14 P.M.    
                   AEROVANE.............40    W AT  4:22 P.M.    
                   ASOS.................38  WSW AT  4:14 P.M.   
                   DAVIS................42  WSW AT  4:14 P.M.    
FASTEST MILE FOR YESTERDAY..............30    W AT  4:22 P.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE...........30    W AT  4:22 P.M.   
MAXIMUM 2-MINUTE DAVIS AVERAGE..........33    W AT  4:21 P.M.  
AVERAGE WIND SPEED AND DIRECTION......17.7 W
                    ASOS..............16.7        
                    DAVIS.............17.7 W [260 deg] 
 
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..........0.23  DEPARTURE.....-1.52  
                         ASOS..............0.22    
TOTAL PRECIPITATION FOR THE YEAR...........3.17  DEPARTURE.....-3.36  
                         ASOS..............3.09
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE......-0.6
TOTAL SNOWFALL FOR THE MONTH................0.7  DEPARTURE......-7.0
TOTAL SNOWFALL FOR THE SEASON...............7.3  DEPARTURE.....-29.8
 

PRELIMINARY CLIMATE SUMMARY FOR FEBRUARY 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
 
2/1  35/20/28/+2/0/0/126/21         37 S    Aero 34 MPH S
2/2  35/28/32/+6/0.18/0.3/000/00    20 NW
2/3  32/19/26/0/0.05/0.4/574/95     39 W    Aero 47 MPH W  
2/4  22/10/16/-10/0/0/601/99        39 WSW  Aero 40 MPH WSW
2/5  16/5/11/-16/0/0/493/81         61 W    Aero 60 MPH W  
2/6  24/10/17/-10/0/0/593/97        38 W    Aero 36 MPH W 
2/7  21/8/15/-12/0/0/474/77         43 W    Aero 41 MPH W
2/8  25/11/18/-9/0/0/370/60         48 WSW
2/9  26/15/21/-6/0/0/600/97         44 WSW  Aero 42 MPH WSW
2/10 32/13/23/-4/0/0/199/32         28 W     
2/11 31/14/23/-4/0/0/456/73         27 SSW  
2/12 36/20/28/0/0/0/.../..          43 WSW  Aero 40 MPH W 
 
2/13 morning low temp. 6 deg; normal low now 20 deg. 
     there is still a trace of old snow on the ground
     
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR FEBRUARY 13
HIGH 64F IN 1951
LOW -10F IN 1967
PRECIP 1.90 INCHES IN 1966
SNOWFALL 13.5 INCHES IN 1894
PEAK GUST 60 MPH SE IN 1972
 
RECORDS FOR FEBRUARY 14
HIGH 56F IN 1949
LOW -8F IN 1979
PRECIP 1.95 INCHES IN 1940
SNOWFALL 11.0 INCHES IN 1914
PEAK GUST 83 MPH SSW IN 2000
 
TODAY'S REPORT By: Robert Skilling