Friday, March 5, 2021

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

FRIDAY, MARCH 5, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0613E
SUNSET:  1739E

A BUSY NORTHWEST WIND CONTINUES…

A persistent northwesterly wind commenced yesterday morning.
Winds averaged about 9 MPH through 9AM, then rapidly escalated
up to 20-23 MPH. Yesterday’s mean wind speed was 15.7 MPH
accompanied by a peak gust of 46 MPH. Today, we are once again
seeing windy conditions averaging 15 MPH with a max gust of
39 MPH. This wind has provided the means for cold air advection.
Temperatures bottomed out at 18F this morning, 5 degrees below
the normal. Dew points have also taken a tumble. 20s were
the story yesterday, but today we have seen those readings slip
to sub-zero this afternoon, an indication of an arctic airmass
(granted it is March, so with a sun angle of 42 degrees it is
a rather moderated one).

We have slowly managed to bring out the sunshine. A broken
mid-level cloud deck dominated for much of the morning before
yielding to filtered sunshine thanks to some high, thin cirrus
clouds.

Visibility has been excellent! 80 to 85 miles can be seen
from the hill.

The high so far today is 30F, 11 degrees below the daily
average max of 41F. The low since midnight is 18F,  5 degrees
below the daily average low of 23F.

Today’s Observations:

7 A.M.
Weather: Broken Altostratus (few cumulus offshore NE-SE)
Temperature: 20F; Dew Point: 5F; Relative Humidity: 52%
Wind: WNW @ 12G21 kts
(Peak Wind: 35 MPH NW @ 6:18 AM)
Sea-level pressure: 29.71 in Hg; rising, then rising more rapidly
Visibility: 80 miles
6-hr Max temp: 22F
6-hr Min temp: 18F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 1 in.
BHO SA 1155 E100 BKN 80 062/20/5/2912G21/971/ FEW CU OFFSHR
DSNT NE-SE PK WND 3130/1118/ 8/110 4/001 53009 10022 20018

10 A.M.
Weather: Broken Altocumulus, Broken Altostratus, Broken Cirrus
(few cumulus offshore NE-SE)
Temperature: 25F; Dew Point: -2F; Relative Humidity: 31%
Wind: WNW @ 15G26 kts
(Peak Wind: 31 MPH WNW @ 8:52 AM)
Sea-level pressure: 29.71 in Hg; rising, then falling
Visibility: 85 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 E75 BKN E100 BKN E250 -BKN 85 062/25/-2/3015G26/971/
FEW CU OFFSHR DSNT NE-SE PK WND 2927/1352/ 8/111 50000

1 P.M.
Weather: Broken Cirrus
Temperature: 29F, Dew point: -4F; Relative Humidity: 24%
Wind: WNW @ 12G30 kts
(Peak Wind: 35 MPH WNW @ 12:42 PM)
Sea-level pressure: 29.69 in Hg; steady, then decreasing
Visibility: 85 miles
6-hr Max temp: 30F
6-hr Min temp: 20F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 1 in.
BHO SA 1755 E250 -BKN 85 054/29/-4/2912G30/969/ PK WND 2830/1742/
8/001 4/001 58008 10030 20020

SUMMARY FOR THURSDAY, MARCH 4, 2021

TEMPERATURE (DEGREES F)
MAX…….38   NORMAL…..41
MIN…….22   NORMAL…..23
MEAN……30   NORMAL…..32

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL……..-2
TOTAL DEPARTURE FOR THE MONTH……………….-12 [-3.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………35  DEPARTURE…….+2
TOTAL HEATING UNITS FOR THE MONTH…………..146  DEPARTURE……+12
TOTAL HEATING UNITS FOR THE SEASON…………4191  DEPARTURE…..-511
TOTAL HEATING UNITS LAST SEASON TO DATE…….4239  DEPARTURE……-48

PEAK WIND GUST (MPH):
420C/Official…………..46 NW  @ 11:56 P.M.
AEROVANE (south tower)…..51 NW  @ 11:56 P.M.
ASOS…………………..45 NW  @ 11:56 P.M.
DAVIS #1……………….46 WNW @ 11:25 P.M.
DAVIS #2 (south tower)…..44 NW  @ 11:56 P.M.
RMY……………………55     @ 11:55 P.M.
VECTOR…………………57     @ 11:56 P.M.
MERLIN…………………50

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………35 NW  @  9:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….32 NW  @ 11:57 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………35 NW  @ 11:57 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………34 NW  @  9:30 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..34 NW  @ 11:55 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..34     @ 11:55 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……15.7 NW [317 total miles] ASOS…………………14.8
DAVIS #1……………..15.7 WNW
DAVIS #2……………..16.4 NW
RMY………………….14.5 NW
VECTOR……………….15.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.00  DEPARTURE….-0.18
ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….0.13  DEPARTURE….-0.55
ASOS………….0.16
TOTAL PRECIPITATION FOR THE YEAR…………..8.13  DEPARTURE….-0.97
ASOS…………8.42

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………..0.0  DEPARTURE…. -0.5
TOTAL SNOWFALL FOR THE MONTH……………… 0.1  DEPARTURE…. -2.0
TOTAL SNOWFALL FOR THE SEASON……………..72.5  DEPARTURE….+23.9

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/-4/0.00/0.0/436/70       26 WNW  AERO 25 WNW  RMY 28
02/11   31/15/23/-4/0.00/0.0/526/84       28 NW   AERO 26 NW   RMY 31
02/12   25/8/17/-10/0.00/0.0/421/67       32 NW   AERO 35 NW   RMY 36
02/13   27/15/21/-7/0.00/0.0/252/40       20 NNW  AERO 20 NNW  RMY 23
02/14   34/24/29/+1/0.00/0.0/000/00       19 ENE  AERO 16 ENE  RMY 19
02/15   31/27/29/+1/0.11/0.0/000/00       21 NNE  AERO 21 NNE  RMY 22
02/16   44/29/37/+9/0.63/0.0/000/00       39 W    AERO 41 W    RMY 43
02/17   30/19/25/-3/0.00/0.0/552/86       40 W    AERO 41 WNW  RMY 40
02/18   29/21/25/-4/0.13/1.7/000/00       24 ENE  AERO 24 ENE  RMY 25
02/19   30/24/27/-2/0.66/7.7/000/00       24 NE   AERO 23 NE   RMY 24
02/20   32/19/26/-3/0.02/0.5/156/24       32 NW   AERO 35 NW   RMY 38
02/21   33/15/24/-5/0.00/0.0/653/100      27 NW   AERO 28 NW   RMY 29
02/22   40/21/31/+2/0.22/T/020/03         41 S    AERO 41 SSE  RMY 44
02/23   43/31/37/+7/0.00/0.0/…/..       31 WNW  AERO 31 WNW  RMY 32
02/24   49/34/42/+12/0.00/0.0/…/..      39 SSW  AERO 39 SSW  RMY 42
02/25   43/28/30/+6/0.00/0.0/…/..       50 WNW  AERO 55 WNW  RMY 57
02/26   40/22/31/+1/0.00/0.0/…/..       22 WNW  AERO 22 WNW  RMY 21
02/27   47/29/38/+7/0.21/0.1/…/..       40 SSE  AERO 41 SSE  RMY 44
02/28   41/33/37/+6/0.01/0.0/…/..       24 NW   AERO 22 NW   RMY 25

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

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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

03/01   42/24/33/+2/0.13/T/…/..        69 WNW   AERO 78 WNW  RMY 78
03/02   27/10/19/-12/T/0.1/…/..        63 WNW   AERO 71 WNW  RMY 69
03/03   45/19/32/0/0.00/0.0/…/..       30 W     AERO 30 W    RMY 34
03/04   38/22/30/0/0.00/0.0/…/..       46 NW    AERO 51 NW   RMY 53

03/05 The low since midnight is 18F, the daily normal low is 23F

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

RECORDS FOR MARCH 5
HIGH 64 IN 1979
LOW -2 IN 1948
PRECIP 1.76 INS. IN 1920, 2001
SNOWFALL 12.0 INS. IN 1917
PEAK GUST 76e MPH WNW IN 1971

RECORDS FOR MARCH 6
HIGH 66 IN 1894
LOW 3 IN 1948, 2007
PRECIP 1.85 INS. IN 2001
SNOWFALL 15.5 INS. IN 2001
PEAK GUST 82 MPH S IN 1959

TODAY’S REPORT PREPARED BY: Andrew Swanson