BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, JANUARY 19, 2009 MARTIN LUTHER KING JR DAY
ALL TIMES ARE IN EASTERN STANDARD TIME
 
TOTAL SNOWFALL REACHES 13 INCHES IN JUST OVER 
24 HOURS FROM TWO SEPARATE SNOWFALL EVENTS
 
Snow began early Sunday morning and accumulated to
7.7 inches by the time it ended at mid-afternoon.
A second snowfall began Sunday evening and ended
before dawn today with a total of 5.3 inches. 
The total melted precipitation for the two snowfall
events was 0.82 inch.  This was low density snowfall
with a ratio of 16:1 where one inch of precipitation
would have equaled 16 inches of snowfall.
 
The total snow depth on the ground at 7 a.m. this
morning measured 18 inches. Our total snowfall for
this season has now reached 51 inches or 28 inches
more than average through this date. 
 
There was little wind with either snowfall event. The
peak wind speed for the first one was 24 MPH E around 4:30
a.m. early Sunday morning.  The second had a couple of
peak wind speeds of 18 MPH N and NW early this morning.  
 
7 A.M.
Weather: Overcast stratocumulus and thin fog
Temperature: 19F, Dew point: 18F, Wind: WNW at 6 kts
Sea-level pressure: 29.65 inches Hg, rising
Visibility: 9 miles, thin fog
6-hour minimum temperature: 19F
24-hour melted precipitation: 0.68 in.
24-hour snowfall: 10.7 inches
Snow depth on ground: 18 inches
BHO SA 1155 E28 OVC 9 039/19/18/2906/965/
THN FG TOTAL NEW SNW PST 24 HRS 10.7 INS/
8/5// 4/018 55002 MANUAL 6013/ ASOS 60015
MANUAL 70069 ASOS 70083 10025 20019
 
10 A.M.
Weather: Overcast stratocumulus, cirrus clouds visible,
breaks in overcast, thin fog and haze 
Temperature: 23F, Dew point: 20F, Wind: WSW at 7 kts,
Wind: direction gradually backing 
Sea-level pressure: 29.67 inches Hg, falling
Visibility: 12 miles, thin fog and haze 
BHO SA 1455 E22 BKN 28 OVC 12 048/23/20/2507/967/
HIER CI CLDS VSB BINOVC THN FH WND GRDLY BACKING/
8/501 50009 
 
1 P.M.  
Weather: High dense cirrus, cirrostratus overcast,
few thin spots E-ESE, partial halo 
Temperature: 31F, Dew point: 26F, Wind: S at 4 kts
Sea-level pressure: 29.62 inches Hg, falling
Visibility: 12 miles, hazy 
6-hour maximum temperature: 31F
BHO SA 1755 E220 OVC 12 032/31/26/1704/962/
DENS CS OVC FEW SML THN SPTS E-ESE PARTIAL HALO HAZY/
8/007 56016 10031 20019
 
WEATHER SUMMARY FOR SUNDAY, JANUARY 18
 
TEMPERATURE (DEGREES F)
MAX.....29    NORMAL.....33 
MIN.....14    NORMAL.....18
MEAN....22    NORMAL.....26
 
DEPARTURE FROM 30-YEAR NORMAL...............-4
TOTAL DEPARTURE FOR THE MONTH..............-85  [-4.9 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............43  DEPARTURE.........+4
TOTAL HEATING UNITS FOR THE MONTH............782  DEPARTURE........+86
TOTAL HEATING UNITS FOR THE SEASON..........3022  DEPARTURE.........-3
TOTAL HEATING UNITS LAST SEASON TO DATE.....2736  DIFFERENCE......+286
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............24   E AT   4:32 A.M. *
                   AEROVANE.............23   E AT   4:32 A.M.  
                   ASOS.................23   E AT   4:33 A.M.        
                   DAVIS................23   E AT   4:00 A.M.         
FASTEST MILE FOR YESTERDAY..............18   E AT   4:31 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE...........18   E AT   4:27 A.M.   
MAXIMUM 2-MINUTE DAVIS AVERAGE..........19   E AT   4:26 A.M.            
                   AVERAGE.............9.1   E
                   ASOS................9.3
                   DAVIS...............9.2  ENE [060 deg]  
* last of several occurrences....
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.69  DEPARTURE.........+0.53
                         ASOS...............0.83
TOTAL PRECIPITATION FOR THE MONTH...........2.86  DEPARTURE.........+0.06
                         ASOS...............3.94 #
TOTAL PRECIPITATION FOR THE YEAR............2.86  DEPARTURE.........+0.06
                         ASOS...............3.94 #
# 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.........10.7   DEPARTURE........+10.2
TOTAL SNOWFALL FOR THE MONTH...............20.6   DEPARTURE........+11.6
TOTAL SNOWFALL FOR THE SEASON..............51.0   DEPARTURE........+28.4
 
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/+5/1.26/0.8/000/00     46 NE    Aero 45 MPH NE
1/8  38/21/30/+4/0.01/0.1/389/70     47 W     Aero 45 MPH W
1/9  25/16/21/-5/0/0/546/98          37 W     Aero 36 MPH W
1/10 24/11/18/-8/0.10/1.0/329/59     28 W
1/11 31/19/25/-1/0.55/5.3/000/00     30 NW
1/12 27/18/23/-3/0.02/0.4/410/73     24 WNW
1/13 34/16/25/-1/0.04/T/107/19       25 SE
1/14 33/10/22/-4/0/0/518/92          47 W
1/15 16/5/11/-15/0/0/000/00          20 NW
1/16 17/0/9/-17/0/0/.../..           26 W
1/17 19/1/10/-16/.../../.../..       23 W
1/18 29/14/22/-4/.../../000/00       24 E
 
1/19 morning low temp: 19F; 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 19
HIGH 59F IN 1973
LOW -11F IN 1887
PRECIP 2.34 INS. IN 1936
SNOWFALL 10.5 INS. IN 1936
PEAK GUST 93e MPH WNW IN 1943
 
RECORDS FOR JANUARY 20
HIGH 59F IN 1951
LOW -9F IN 1901
PRECIP 1.95 INS. IN 1978
SNOWFALL 19.0 INS. IN 1978 [RECORD FOR MONTH]
PEAK GUST 76e MPH NE IN 1978
 
TODAY'S REPORT PREPARED By: Robert Skilling