BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

WEDNESDAY, FEBRUARY 17, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0638E
SUNSET:  1719E

ALMOST PERFECT VISIBILITY AND FAIR WEATHER AFTER 
YESTERDAY'S RAIN....

Today we observed partly cloudy skies and excellent 
visibility following yesterday's rainfall. Visibility
was 85 miles at 1 P.M., which is very close to the 
maximum of 90 miles. Pressure was on a very fast rise
this morning, indicative of a cold and dry air mass 
entering the region. Overnight, pressure has risen
more than 20 millibars. Humidity is 35% in the 
early afternoon hours. 

The high so far today is 28F, 9 degrees below the daily 
average max of 37F. The low since midnight is 19F, the
same as the normal minimum.


Today's Observations:

7 A.M.
Weather: Clear, few cumulus 
Temperature: 19F; Dew Point: 9F; Relative Humidity: 65%
Wind: W @ 10 kts
Sea-level pressure: 30.15 in Hg; rising, then more rapidly
Visibility: 70 mile
6-hr Max temp: 27F
6-hr Min temp: 19F
24-hr Precip: 0.44 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 10 ins.
BHO SA 1155 CLR 70 209/19/9/2810/015/ FEW CU ALQDS/ 8/100 
4/010 70044 51058 10027 20019

10 A.M.
Weather: Scattered altocumulus and cirrostratus, few 
cumulus
Temperature: 24F; Dew Point: 8F; Relative Humidity: 51%
Wind: WNW @ 12G20 kts
Sea-level pressure: 30.25 in Hg; rising, then more rapidly
Visibility: 80 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 160 SCT 250 SCT 80 245/24/8/2912G20/025/ FEW CU 
ALQDS/ 8/186 51036

1 P.M.
Weather: Broken cirrostratus
Temperature: 27F, Dew point: 7F; Relative Humidity: 42%
Wind: NW @ 12G18 kts
Sea-level pressure: 30.28 in Hg, rising steadily
Visibility: 85 miles 
6-hr Max temp: 28F
6-hr Min temp: 19F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 9 ins.
BHO SA 1755 250 BKN 85 253/27/7/3212G18/028/ 8/006 4/009 51008 
10028 20019


SUMMARY FOR TUESDAY, FEBRUARY 16, 2021

TEMPERATURE (DEGREES F)
MAX.......44   NORMAL.....37
MIN.......29   NORMAL.....19
MEAN......37   NORMAL.....28

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL........ +9
TOTAL DEPARTURE FOR THE MONTH.................... +10 [+0.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............28  DEPARTURE.......-9
TOTAL HEATING UNITS FOR THE MONTH..............600  DEPARTURE......-11
TOTAL HEATING UNITS FOR THE SEASON............3644  DEPARTURE.....-498
TOTAL HEATING UNITS LAST SEASON TO DATE.......3750  DEPARTURE.....-106

PEAK WIND GUST (MPH):
                     420C/Official..............39 W   @ 10:36 P.M.
                     AEROVANE (south tower).....41 W   @ 10:36 P.M. 
                     ASOS.......................38 W   @ 10:36 P.M.
                     DAVIS #1...................39 W   @ 10:35 P.M.
                     DAVIS #2 (south tower).....43 WNW @ 10:36 P.M.
                     RMY........................43     @ 10:36 P.M
                     VECTOR.....................47     @ 10:36 P.M.
                     MERLIN.....................N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL..................32 W   @ 10:37 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE...................29 W   @ 10:37 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE...............33 WNW @ 10:37 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE...............32 WNW @ 10:36 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE....................27 WNW @ 10:34 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE.................30     @ 10:34 P.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL....11.1 E [266 total miles]
                     ASOS...................11.2     
                     DAVIS #1...............11.4 WSW  
                     DAVIS #2...............11.3 NNW  
                     RMY....................10.9 S
                     VECTOR.................10.6

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.......0.44  DEPARTURE....+0.30
                             ASOS.............0.49
TOTAL PRECIPITATION FOR THE MONTH.............4.43  DEPARTURE....+2.22
                             ASOS.............4.65
TOTAL PRECIPITATION FOR THE YEAR..............6.75  DEPARTURE....+0.19
                              ASOS............7.00

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M...........0.0  DEPARTURE.... -0.5
TOTAL SNOWFALL FOR THE MONTH..................29.0  DEPARTURE....+21.1
TOTAL SNOWFALL FOR THE SEASON.................62.4  DEPARTURE....+21.4


PRELIMINARY CLIMATE SUMMARY FOR FEBRUARY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
M:    Missing data

02/01   32/21/27/+1/1.86/12.7/000/00      53 NE   AERO 65 NE   RMY 62
02/02   34/29/32/+6/0.91/1.6/000/00       52 NNE  AERO 55 NE   RMY 58
02/03   34/26/30/+4/0.01/0.2/036/06       20 NW   AERO 20 NW   RMY 22
02/04   37/26/32/+6/0.02/0.7/158/26       23 NW   AERO 22 NW   RMY M       
02/05   39/26/33/+7/0.01/T/000/00         33 S    AERO 32 S    RMY 30
02/06   40/28/34/+8/0.00/0.0/595/97       42 WSW  AERO 41 WSW  RMY 47
02/07   35/25/30/+3/0.71/11.6/000/00      27 WNW  AERO 28 WNW  RMY 30
02/08   27/13/20/-7/0.00/0.0/619/100      29 NW   AERO 31 WNW  RMY 32
02/09   27/18/23/-4/0.17/2.2/000/00       16 N    AERO 16 N    RMY 17
02/10   31/15/23/-4/0.00/0.0/.../..       26 WNW  AERO 25 WNW  RMY 28
02/11   31/15/23/-4/0.00/0.0/.../..       28 NW   AERO 26 NW   RMY 31
02/12   25/8/17/-10/0.00/0.0/.../..       32 NW   AERO 35 NW   RMY 36
02/13   27/15/21/-7/0.00/0.0/.../..       20 NNW  AERO 20 NNW  RMY 23
02/14   34/24/29/+1/0.00/0.0/.../..       19 ENE  AERO 16 ENE  RMY 19
02/15   31/27/29/+1/0.11/0.0/.../..       21 NNE  AERO 21 NNE  RMY 22
02/16   44/29/37/+9/0.63/0.0/.../..       39 W    AERO 41 W    RMY 43

The low since midnight is 19F, the daily normal low is 19F

DAILY RECORDS

02/01 -RECORD SNOWFALL OF 12.7 INS, BREAKING PREVIOUS RECORD
       OF 11.0 INS SET IN 1898
02/01 -RECORD PRECIPITATION OF 1.86 INS, BREAKING PREVIOUS 
       RECORD OF 1.30 INS SET IN 1898 

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated)

RECORDS FOR FEBRUARY 17
HIGH 61F IN 1981
LOW -16F IN 1896
PRECIP 1.86 INCHES IN 2003
SNOWFALL 20.0 INCHES IN 2003
PEAK GUST 72 MPH NW IN 1968

RECORDS FOR FEBRUARY 18
HIGH 65F IN 1981
LOW -10F IN 1958
PRECIP 1.97 INCHES IN 1887, IN 1952
SNOWFALL 9.2 INCHES IN 1952
PEAK GUST 70 MPH S IN 2008

TODAY'S REPORT PREPARED BY: Benjamin Turner