BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MARCH 16, 2009
ALL TIMES ARE IN EASTERN STANDARD TIME
 
BACK-DOOR COLD FRONT PASSAGE EARLY THIS MORNING
BRINGS COLD NORTHEAST WINDS AND LOW CLOUDS
 
The passage of a back-door cold front from the
north and northeast early this morning brought
a gradual wind shift overnight.  Winds, which were
light from the west at midnight, became gusty
up to 25 to 30 MPH from the north veering to the
north-northeast and finally northeast just after
4 a.m. EDT. The low clouds continue to block out
any sunshine today and the day's high temperature
is likely to be the 42-degree reading at midnight.
Yesterday's high temperature of 59 degrees
occurred just before a seabreeze brought a wind
shift from southwest to east and colder weather
with temperatures falling into the 40's by dark.   
 
Today's observations:
 
7 A.M.
Weather: Overcast stratus, ceiling ragged  
Temperature: 35F, Dew point: 31F, Wind: NE at 11 kts,
Wind: gust to 23 kts past hour,
Wind: direction is variable N-ENE
Sea-level pressure: 30.38 inches Hg, rising
Visibility: 15 miles, 12 miles SE, but 20 miles W-N,
thin fog all quadrants 
6-hour minimum temperature: 34F
BHO SA 1155 E12 OVC 15 288/35/31/0411/038/
CIG RGD THN FG ALQDS VSBY SE 12 W-N 20
GST TO 23 KTS PST HR WND 36V06/ 8/6//
51040 10040 20035
 
10 A.M.
Weather: Overcast stratocumulus 
Temperature: 36F, Dew point: 30F, Wind: NE at 12 kts
Sea-level pressure: 30.43 inches Hg, rising
Visibility: 20 miles, hazy
BHO SA 1455 E13 OVC 20 306/36/30/0412/043/
HAZY GST 20 KTS PST HR WND 01V07/ 8/5// 51018
 
1 P.M.  
Weather: Overcast stratocumulus, bright spots in overcast,
sun dimly visible
Temperature: 37F, Dew point: 28F, Wind: NE at 10 kts,
Wind: direction variability N-E
Sea-level pressure: 30.43 inches Hg, falling
Visibility: 30 miles, 25 miles northeast thru southeast, hazy
6-hour maximum temperature: 37F   
BHO SA 1755 E18 OVC 30 306/37/28/0410/043/
BRGHT SPTS IOVC SUN DMLY VSBY LGT HZ VSBY NE-SE 25
WND 35V08/ 8/5// 50000 10037 20035  
 
WEATHER SUMMARY FOR SUNDAY, MARCH 15, 2009
 
TEMPERATURE (DEGREES F)
MAX.....59    NORMAL.....44
MIN.....34    NORMAL.....27
MEAN....47    NORMAL.....36
 
DEPARTURE FROM 30-YEAR NORMAL.................+11
TOTAL DEPARTURE FOR THE MONTH.................- 2 [-0.3 DEGREES/DAY] 
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............18  DEPARTURE........-11
TOTAL HEATING UNITS FOR THE MONTH............470  DEPARTURE..........0
TOTAL HEATING UNITS FOR THE SEASON..........4997  DEPARTURE........-43
TOTAL HEATING UNITS LAST SEASON TO DATE.....4672  DIFFERENCE......+325
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............17 SSW AT  2:02 P.M. 
                   AEROVANE.............16 SSW AT  2:02 P.M. 
                   ASOS.................17 E   AT  4:17 P.M.    
                   DAVIS................18 SSW AT  2:01 P.M.   
FASTEST MILE FOR YESTERDAY..............13 SSW AT  1:03 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...........13 E   AT  4:14 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE..........14 E   AT  4:14 P.M.   
                   AVERAGE............ 8.7 WSW
                   ASOS................8.3
                   DAVIS...............8.1 SW [220 DEGREES]
 
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...........2.41 DEPARTURE.........+0.14
                         ASOS...............2.34
TOTAL PRECIPITATION FOR THE YEAR............8.94 DEPARTURE.........-2.17
                         ASOS...............9.96 #
# Includes erroneous ASOS precipitation data on 1/1/09, 1/2/09 and 2/27/09.
 
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0   DEPARTURE.........-0.4
TOTAL SNOWFALL FOR THE MONTH...............13.4   DEPARTURE.........+6.8
TOTAL SNOWFALL FOR THE SEASON..............78.7   DEPARTURE........+26.7
 
PRELIMINARY CLIMATE SUMMARY FOR MARCH 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
 
3/1  28/21/25/-7/0.26/1.9/000/00     38 NNE
3/2  22/15/19/-13/1.21/8.2/000/00    40 NNE    AERO 37 MPH NNE
3/3  25/11/18/-14/0.01/0.1/640/94    33 NW
3/4  30/6/18/-14/0/0/684/100         31 WNW
3/5  39/16/28/-5/0/0/659/96          25 WSW
3/6  49/30/40/+7/T/0/152/22          43 S      AERO 41 MPH S
3/7  60/42/51/+18/0.06/0/429/62      37 S
3/8  57/42/50/+16/0/0/445/64         39 WNW    AERO 40 MPH WNW
3/9  42/28/35/+1/0.72/3.2/000/00     33 N
3/10 42/26/34/0/0.02/0/470/67        23 SSE
3/11 50/33/42/+7/0.13/0/000/00       51 W
3/12 39/25/32/-3/0/0/685/97          44 W      AERO 45 MPH W
3/13 37/19/28/-7/0/0/660/93          26 SSE
3/14 50/25/38/+2/0/0/613/86          24 SSW
3/15 59/34/47/+11/0/0/.../..         17 SSW
 
3/16 morning low temp: 34F; our normal low is now 28F
 
NEW DAILY RECORDS FOR MARCH 2009...
3/2: DAILY SNOWFALL 8.2 INS. SURPASSES PREVIOUS
     RECORD OF 7.1 INS. IN 1948
3/7: DAILY MINIMUM 42 TIES RECORD HIGH MINIMUM FOR DATE
     PREVIOUSLY SET IN 1974 AND 1987
3/8: DAILY MINIMUM 42 TIES RECORD HIGH MINIMUM FOR DATE
     PREVIOUSLY SET IN 1995
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MARCH 16
HIGH 73 IN 1990
LOW 8 IN 1932
PRE 1.95 INS. IN 1900
SNOW 10.0 INS. IN 1896
WIND 79 MPH NE IN 1956
 
RECORDS FOR MARCH 17
HIGH 69 IN 2003
LOW 6 IN 1885
PRECIP 1.97 INS. IN 1968
SNOWFALL 6.5 INS. IN 1956
PEAK GUST 70 MPH SSW IN 1973
 
TODAY'S REPORT PREPARED BY: Robert Skilling