Monday, March 13, 2023

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

MONDAY, MARCH 13, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0600E
SUNSET:  1748E

THE PROVERBIAL CALM BEFORE THE STORM; RAIN ARRIVED EARLY THIS
AFTERNOON…

Conditions were quiet this morning with increasing clouds and
generally light wind. However rain arrived early this afternoon
and the wind is starting to freshen out of the east. Meanwhile
what promises to be a strong western Atlantic cyclone is taking
shape off the North Carolina coast as we speak. The system
already has an eye like feature and associated convective
complex on its north and northeast quadrant. This system is
now primed for bombogenesis! As they say, from here, we’re off
to the races!

Temperatures rose into the low 40s late this morning, but have
since settled back into the upper 30s with the light rain
falling.

As mentioned, winds were generally light this morning, but have
freshened as the afternoon progresses. Gusts have already started
to break the 20mph barrier, heading for much higher values by
this time tomorrow afternoon. The average speed for the day so
far is only around 8mph, really indicative of the “calm” earlier
this morning.

Visibility has been limited all day, peaking at only around 20
miles this morning. It has of course lowered this afternoon with
the onset of the rain, now under 10 miles.

The high so far today is 41F, which is 2 degrees below the normal
maximum of 43F. The low temperature since midnight is 32F, which
is 6 degrees above the normal low of 26F.

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Today’s Observations:

7 A.M.
Weather: Broken altostratus, overcast cirrostratus, few stratocumulus
all quadrants
Temperature: 35F; Dew Point: 31F; Relative Humidity: 87%
Wind: E @ 7 kts
Sea-level pressure: 1017.8 mb; 30.06 in. Hg: falling, then rising
Visibility: 20 miles, thin fog
6-hr Max temp: 35F
6-hr Min temp: 33F
24-hr Precip: 0.00 ins.
24-hr Snowfall: 0.0 ins.
Snow Depth: Trace
BHO SA 1155 E120 BKN 180 OVC 20 178/35/31/0907/006/ FEW SC ALQDS
THN F ALQDS/ 8/517 4/000 55004 10035 20033

10 A.M.
Weather: Broken stratocumulus, overcast altostratus
Temperature: 39F; Dew Point: 33F; Relative Humidity: 78%
Wind: E @ 6 kts, wind light
Sea-level pressure: 1018.3 mb; 30.07 in. Hg: rising, then falling
Visibility: 20 miles, hazy
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E20 BKN 30 OVC 20 183/39/33/1006/007/ HAZY WND LGT/ 8/52/ 50005

1 P.M.
Weather: Overcast stratocumulus, very light rain
Temperature: 40F; Dew Point: 32F; Relative Humidity: 73%
Wind: ESE @ 9 kts
Sea-level pressure: 1016.3 mb; 30.01 in. Hg: falling, then more rapidly
Visibility: 15 miles
6-hr Max temp: 41F
6-hr Min temp: 35F
6-hr Precip:  Trace
6-hr Snowfall: 0.0 ins.
Snow Depth: Trace
BHO SA 1755 E26 OVC 15R- 163/40/32/1209/001/ R-B09 PCPN VRY LGT/
8/5// 4/000 58020 6000/ 10041 20035

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SUMMARY FOR SUNDAY, MARCH 12, 2023

TEMPERATURE (DEGREES F)
MAX…….41   NORMAL…..43
MIN…….28   NORMAL…..26
MEAN……35   NORMAL…..34

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……….+1
TOTAL DEPARTURE FOR THE MONTH…………………+32 [+2.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY……………30  DEPARTURE……..-1
TOTAL HEATING UNITS FOR THE MONTH…………..355  DEPARTURE…….-33
TOTAL HEATING UNITS FOR THE SEASON…………4075  DEPARTURE……-745
TOTAL HEATING UNITS LAST SEASON TO DATE…….4429  DEPARTURE……-354

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
420C, Contacting, Merlin and Richards are all Main Tower.

420C (Official)…………26 NNE @  7:52 A.M.
VECTOR #1 (1-Sec)……….26 NNE @  7:52 A.M.
VECTOR #2 (1-Sec)……….27 NE  @  8:10 A.M.
DAVIS #1……………….25 NNE @  7:52 A.M.
DAVIS #2 ………………25 NE  @  8:11 A.M.
RMY #1 (Instantaneous)…..27 NE  @  8:49 A.M.
RMY #2 (Instantaneous)…..26 NE  @  8:10 A.M.
MERLIN…………………24 N
RICHARDS (C5C) (Inst)……24     @  8:49 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………17 NE   @   9:43 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..17      @   9:43 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..18      @   8:22 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………18 NE   @   9:43 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………18 E    @   2:16 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..17 ENE  @   2:27 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..17 NE   @   8:22 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………17      @   2:27 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……. 9.8 ENE [235 total miles] VECTOR #1…………….. 9.6
VECTOR #2……………..10.2
DAVIS #1………………10.1 NE
DAVIS #2………………10.2 ENE
RMY #1……………….. 9.7 NE
RMY #2………………..10.0 NE
RICHARDS (C5C)…………10.2

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.17
TOTAL PRECIPITATION FOR THE MONTH…………..1.28 DEPARTURE…..-0.81
TOTAL PRECIPITATION FOR THE YEAR……………9.93 DEPARTURE…..-0.66

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE……-0.6
TOTAL SNOWFALL FOR THE MONTH………………..3.4 DEPARTURE……-3.9
TOTAL SNOWFALL FOR THE SEASON (2022-2023)……27.7 DEPARTURE…..-31.5

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PRELIMINARY CLIMATE SUMMARY FOR MARCH CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
VEC1: Vector #1 1-second gust
RMY:  R.M. Young wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

3/1   43/27/35/+4/0.00/0.0/425/63         20 NW   VEC1 21 SE  RMY 21
3/2   40/34/37/+5/0.31/0.0/000/00         35 NW   VEC1 36 NW  RMY 39
3/3   44/29/37/+5/0.01/0.1/462/68         33 NW   VEC1 34 NW  RMY 36
3/4   33/28/31/-1/0.82/3.3/000/00         48 E    VEC1 49 NE  RMY 52
3/5   41/25/33/+1/0.00/0.0/240/35         35 NW   VEC1 36 NW  RMY 37
3/6   46/31/39/+6/0.00/0.0/571/83         46 WNW  VEC1 48 NW  RMY 51
3/7   38/26/32/-1/T/T/387/56              41 NW   VEC1 42 NW  RMY 46
3/8   44/26/35/+2/T/T/…/..              32 N    VEC1 34 N   RMY 34
3/9   47/32/40/+7/0.00/0.0/…/..         28 NW   VEC1 28 NW  RMY 29
3/10  49/27/38/+4/0.00/0.0/…/..         18 W    VEC1 18 SE  RMY 17
3/11  36/29/33/-1/0.14/0.0/…/..         32 NE   VEC1 34 NE  RMY 34
3/12  41/28/35/+1/0.00/0.0/…/..         26 NNE  VEC1 26 NNE RMY 27

3/13  The low since midnight is 32F, the daily normal low is 26F

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

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”]

RECORDS FOR MARCH 14
HIGH 74 IN 1946
LOW 7 IN 1896
PRECIP 4.95 INS. IN 2010
SNOWFALL 7.3 INS. IN 2017
PEAK GUST 67 MPH ENE IN 2010

TODAY’S REPORT PREPARED BY: Matt Douglas