Friday, March 12, 2021

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

FRIDAY, MARCH 12, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0601E
SUNSET:  1747E

MORNING CLOUDS ONCE AGAIN YIELD TO SUNSHINE, SLIGHTLY
COOLER YET STILL MILD….

Today’s morning clouds were quicker to exit compared to
yesterday. This has allowed for plentiful sunshine under
mostly clear skies and temperatures around 60F – a truly
spectacular day.

A wind shift from the south-southwest to the west occurred
during the pre-dawn hours and has since ushered in much drier
air. Dew points began in the low-30s at 7AM, but have since
fallen to 16F. Accounting for air temperatures in the low-60s,
humidity values are bone-dry…around 18%! 

Visibility has been outstanding today. Perfect visibility was
recorded at 7AM and has since remained stable at 85 miles thanks
to the dry air mass and large dew point depressions.

Dry conditions continue to be the theme of this month. No
measurable precipitation since March 1st. The monthly
total stands at 0.13″, which is 1.78″ below normal. The yearly
total is 8.13″ which is 2.20″ below normal to date.

The high so far today is 60F, 17 degrees above the daily
normal max of 43F. The low since midnight is 48F, 25 degrees
above the daily average low of 23F.

Today’s Observations:

7 A.M.
Weather: Broken Altocumulus, Broken Altostratus
Temperature: 53F; Dew Point: 30F; Relative Humidity: 40%
Wind: W @ 18G27 kts
Peak Wind: 41 MPH WNW @ 5:56 AM
Sea-level pressure: 30.00 in Hg; Rising, then rising more slowly
Visibility: 90 miles (perfect/maximum)
6-hr Max temp: 53F
6-hr Min temp: 48F
24-hr Precip: 0.00 ins.
24-hr Snow: 0.0 ins.
Snow Depth: Trace
BHO SA 1155 E150 BKN E200 BKN 90 160/53/30/2618G27/000/ CLRG
LINE DSNT SW-NE MVG E PK WND 2936/1056/ 8/050 4/000 51025 10053
20048

10 A.M.
Weather: Scattered Altocumulus/Altostratus (Few Cirrus distant NE;
Line of Altocumulus/Altostratus E-SSW)
Temperature: 57F; Dew Point: 17F; Relative Humidity: 20%
Wind: W @ 20G28 kts
Peak Wind: 32 MPH W @ 9:54 AM
Sea-level pressure: 30.02 in Hg; Rising, then falling
Visibility: 85 miles
3-hr Precip: 0.00 ins.
3-hr Snow: 0.0 ins.
BHO SA 1455 E150 SCT 85 166/57/17/2720G28/002/ FEW CI DSNT NE
LINE AC/AS E-SSW PK WND 2828/1454/ 8/031 50006

1 P.M.
Weather: Scattered Cirrostratus (Cirrostratus line E-SSW)
Temperature: 59F, Dew point: 16F; Relative Humidity: 18%
Wind: W @ 14G25 kts
Sea-level pressure: 29.98 in Hg; falling, then more rapidly
Visibility: 85 miles
6-hr Max temp: 60F
6-hr Min temp: 53F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: Trace
BHO SA 1755 E220 SCT 85 152/59/16/2714G25/998/ LINE CS E-SSW/ 8/005
4/000 58014 10060 20053

SUMMARY FOR THURSDAY, MARCH 11, 2021

TEMPERATURE (DEGREES F)
MAX…….71 [NEW RECORD] NORMAL…..43
MIN…….35              NORMAL…..25
MEAN……53              NORMAL…..34

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…….+19
TOTAL DEPARTURE FOR THE MONTH………………+/-0 [-0.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………12  DEPARTURE……-19
TOTAL HEATING UNITS FOR THE MONTH…………..359  DEPARTURE……..0
TOTAL HEATING UNITS FOR THE SEASON…………4404  DEPARTURE…..-523
TOTAL HEATING UNITS LAST SEASON TO DATE…….4376  DEPARTURE……+28

PEAK WIND GUST (MPH):
                     420C/Official…………..41 SSW @  3:36 P.M.
                     AEROVANE (south tower)…..43 SSW @  3:36 P.M.
                     ASOS…………………..41 SSW @  3:37 P.M.
                     DAVIS #1……………….42  SW @  3:36 P.M.
                     DAVIS #2 (south tower)…..40 SSW @  3:36 P.M.
                     RMY……………………46     @  3:36 P.M.
                     VECTOR…………………48     @  3:36 P.M.
                     MERLIN…………………43    

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………29 SSW @  2:27 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….29 SSW @  3:40 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………29  SW @  3:40 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………30 SW  @  3:40 P.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..28 SSW @  3:11 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..28     @  3:10 P.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL……18.3 SSW [440 total miles]                     ASOS…………………18.2    
                     DAVIS #1……………..17.2  SW  
                     DAVIS #2……………..18.3 SSW
                     RMY………………….17.9  SW
                     VECTOR……………….18.4

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………….0.13  DEPARTURE….-1.78
                             ASOS………….0.16
TOTAL PRECIPITATION FOR THE YEAR…………..8.13  DEPARTURE….-2.20
                              ASOS…………8.42

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HOURS ENDING 7 A.M………  0.0  DEPARTURE…. -0.4
TOTAL SNOWFALL FOR THE MONTH……………… 0.1  DEPARTURE…. -5.5
TOTAL SNOWFALL FOR THE SEASON……………..72.5  DEPARTURE….+20.4

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/-2/0.00/0.0/…/..      46 NW   AERO 51 NW   RMY 53
03/05   31/18/25/-7/0.00/0.0/…/..      39 WNW  AERO 44 NW   RMY 45
03/06   33/15/24/-8/0.00/0.0/…/..      28 WNW  AERO 29 WNW  RMY 30
03/07   35/15/25/-8/0.00/0.0/…/..      21 NW   AERO 22 NW   RMY 23
03/08   38/19/29/-4/T/T/…/..           20 NW   AERO 20 NW   RMY 21
03/09   56/30/43/+10/T/T/…/..          32 WNW  AERO 35 WNW  RMY 37
03/10   54/32/43/+10/0.00/0.0/…/..     29 SSW  AERO 29 SSW  RMY 31
03/11   71/35/53/+19/0.00/0.0/…/..     41 SSW  AERO 43 SSW  RMY 46

03/12 The low since midnight is 48F, the daily normal low is 25F

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

RECORDS FOR MARCH 12
HIGH 72 IN 2012
LOW 2 IN 1885
PRECIP 2.87 INS. IN 1888
SNOWFALL 9.7 INS. IN 1959
PEAK GUST 66 MPH SE IN 1962

RECORDS FOR MARCH 13
HIGH 72 IN 1990
LOW -1 IN 1885
PRECIP 2.47 INS. IN 1993
SNOWFALL 23.0 INS. IN 2018 [RECORD FOR MONTH]PEAK GUST 76 MPH ENE IN 1993 [THE “STORM OF THE CENTURY”]

TODAY’S REPORT PREPARED BY: Andrew Swanson