Sunday, January 21, 2024

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

SUNDAY, JANUARY 21, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0708E
SUNSET:  1644E

AN ARCTIC AIR MASS REMAINS IN PLACE TODAY, WITH SOME SNEAKY SNOW
FALLING YESTERDAY AFTERNOON AND EVENING….

Much to the surprise of many, a period of mainly light snow
developed mid afternoon yesterday, and continued well into the
evening hours last night. 0.7″ of snow was measured here on the
Hill, with a liquid equivalent of 0.05″.

After some clouds early this morning, the skies have cleared out
nicely, leaving us with abundant sunshine. Temperatures however
remain on the cold side despite the sun. Readings have only
reached the low 20s early this afternoon, after the starting the
day at 10F.

The dew point remains in the single digits, very much indicative
of an arctic air mass.

The wind has also remained on the active side, with an average
speed of around 15mph. Gusts of 20-25mph have been common. This
is of course causing wind chill values to hover in the single digits.

Visibility has been decent, with a view of 60-70 miles all day.

The maximum temperature so far today is 22F degrees, this is 12
degrees below the normal high of 34F. The minimum temperature
so far since midnight is 10F degrees, this is 7 degrees below
the normal low of 17F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Broken altocumulus, few stratocumulus offshore distant
NNE-SE-SSW, virga N-NE
Temperature: 11F; Dew Point: 3F; Relative Humidity: 71%
Wind: NW @ 15G23 kts
Sea-level pressure: 1020.2 mb; 30.13 in. Hg: rising, then more rapidly
Visibility: 60 miles
6-hr Max temp: 12F
6-hr Min temp: 10F
24-hr Precip: 0.05 inches
24-hr Snowfall: 0.7 inches
Snow Depth: 2 inches
BHO SA 1155 E100 BKN 60 202/11/3/3215G23/013/ FEW SC OFFSHR DSNT
NNE-SE-SSW VIRGA N-NE TOTAL NEW SNW PST 24 HRS 0.7 INS/ 8/550 4/002
53028 70005 10012 20010

10 A.M.
Weather: Clear, few stratocumulus offshore distant NNE-ESE and
distant SSE-S, few altocumulus distant ESE-SSE
Temperature: 16F; Dew Point: 4F; Relative Humidity: 59%
Wind: NW @ 12G18 kts
Sea-level pressure: 1022.7mb; 30.20 in. Hg: rising, then more slowly
Visibility: 60 miles
3-hr Precip: 0.00 inches
3-hr Snowfall: 0.0 inches
BHO SA 1455 CLR 60 227/16/4/3112G18/020/ FEW SC OFFSHR DSNT NNE-ESE
AND DSNT SSE-S FEW AC DSNT ESE-SSE/ 8/550 51025

1 P.M.
Weather: Clear, few stratocumulus offshore distant NE-ESE
Temperature: 22F; Dew Point: 7F; Relative Humidity: 53%
Wind: NW @ 10G16 kts
Sea-level pressure: 1021.9 mb; 30.18 in. Hg: rising, then falling
Visibility: 70 miles
6-hr Max temp: 22F
6-hr Min temp: 11F
6-hr Precip: 0.00 inches
6-hr Snowfall: 0.0 inches
Snow Depth: 1 inch
BHO SA 1755 CLR 70 219/22/7/3110G16/018/ FEW SC OFFSHR DSNT NE-ESE/
8/500 4/001 58008 10022 20011

————————————————————–

SUMMARY FOR SATURDAY, JANUARY 20, 2024

TEMPERATURE (DEGREES F)
MAX…….20   NORMAL…..34
MIN…….10   NORMAL…..18
MEAN……15   NORMAL…..26

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………..-11
TOTAL DEPARTURE FOR THE MONTH…………………..+58 [+2.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2023 THRU JUN 2024)
TOTAL HEATING UNITS FOR YESTERDAY……………50  DEPARTURE…….+11
TOTAL HEATING UNITS FOR THE MONTH…………..703  DEPARTURE…….-59
TOTAL HEATING UNITS FOR THE SEASON…………2598  DEPARTURE……-374
TOTAL HEATING UNITS LAST SEASON TO DATE…….2493  DEPARTURE……+105

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all Main Tower.
E=Estimated

F420C (Official)……….E30 NW   @  12:04 A.M.
VECTOR #1 (1-Sec)……….30 NW   @  12:13 A.M.
VECTOR #2 (1-Sec)……….32 NW   @  01:30 A.M.
DAVIS #1……………….29 WNW  @  10:21 P.M.
DAVIS #2 ………………30 NNW  @  01:30 A.M.
RMY #1 (Instantaneous)…..31 NW   @  12:12 A.M.
RMY #2 (Instantaneous)…..32 NW   @  01:30 A.M.
MERLIN…………………M
RICHARDS (C5C) (Inst)……29      @  12:06 A.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 NW   @  12:14 A.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21      @  12:14 A.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..22      @  05:41 A.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………21 NW   @  12:15 A.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 NW   @  05:42 A.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..20 NW   @  12:14 A.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..21 NW   @  05:41 A.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………21      @  12:15 A.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……13.2 NW [317 total miles] VECTOR #1…………….12.7
VECTOR #2…………….14.0
DAVIS #1……………..13.3 NW
DAVIS #2……………..13.6 NW
RMY #1……………….12.5 NW
RMY #2……………….13.6 NW
RICHARDS (C5C)………..13.3

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.05 DEPARTURE…..-0.08
TOTAL PRECIPITATION FOR THE MONTH…………..6.95 DEPARTURE…..+3.98
TOTAL PRECIPITATION FOR THE YEAR (2024)……..6.95 DEPARTURE…..+3.98

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.7 DEPARTURE……+0.1
TOTAL SNOWFALL FOR THE MONTH……………….17.5 DEPARTURE……+6.0
TOTAL SNOWFALL FOR THE SEASON (2023-2024)……17.8 DEPARTURE……-8.8

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR JANUARY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY:  R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

1/1   37/25/31/+2/0.00/0.0/296/54         15 N   VEC1 14 N   RMY 15
1/2   39/19/29/+1/0.00/0.0/550/100        17 WNW VEC1 17 WNW RMY 17
1/3   42/25/34/+6/0.00/0.0/347/63         20 WNW VEC1 21 WNW RMY 21
1/4   42/21/32/+4/T/T/237/43              37 NNW VEC1 36 NNW RMY 39
1/5   32/17/25/-3/0.00/0.0/542/98         40 NW  VEC1 39 NW  RMY 39
1/6   34/24/29/+1/0.11/0.2/022/04         36 E   VEC1 36 E   RMY 36
1/7   33/21/27/0/0.84/13.0/000/00         38 ENE VEC1 37 ENE RMY 42
1/8   32/21/27/0/0.00/0.0/406/73          28 NW  VEC1 28 NW  RMY 31
1/9   40/23/32/+5/0.98/T/000/00           46 SE  VEC1 49 SE  RMY 46
1/10  53/41/47/+20/1.90/0.0/201/36        70 SSE VEC1 69 SSE RMY 75
1/11  43/35/39/+12/0.00/0.0/162/29        45 WNW VEC1 43 WNW RMY 47
1/12  47/33/40/+13/0.00/0.0/533/95        29 SE  VEC1 28 ESE RMY 28
1/13  57/36/47/+21/1.72/0.0/146/26        47 ESE VEC1 51 ESE RMY 49
1/14  39/22/31/+5/0.02/0.4/328/58         53 WNW VEC1 52 WNW RMY 54
1/15  31/17/24/-2/T/T/475/84              30 WNW VEC1 29 WNW RMY 30
1/16  34/19/27/+1/0.61/3.2/000/00         36 NW  VEC1 33 NW* RMY 31*
1/17  25/13/19/-7/0.00/0.0/529/93         29 NW  VEC1 28 W*  RMY 27*
1/18  26/13/20/-6/0.00/0.0/…/..         30 WSW VEC1 30 WSW RMY 29
1/19  27/16/22/-4/T/T/…/..              31 NW  VEC1 30 NW  RMY 34
1/20  20/10/15/-11/0.05/0.7/…/..        30 NW  VEC1 30 NW  RMY 31

1/21 The low since midnight is 10F, the daily normal low is 17F

* Reading impacted by icing

————————————————————–

JANUARY DAILY RECORDS TO DATE

1/13: RECORD PRECIPITATION OF 1.72 INS,
BEATS PREVIOUS RECORD OF 1.54 INS SET IN 1979

————————————————————–

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

RECORDS FOR JANUARY 21
HIGH 65F IN 1906
LOW -4F IN 1888
PRECIP 2.49 INS. IN 1979
SNOWFALL 9.0 INS. IN 2014
PEAK GUST 78e MPH SE IN 1979

RECORDS FOR JANUARY 22
HIGH 59F IN 1916
LOW -8F IN 1888,1976
PRECIP 1.24 INS. IN 1891,1987
SNOWFALL 10.0 INS. IN 2005
PEAK GUST 67 MPH W IN 1976

TODAY’S REPORT PREPARED BY: Matt Douglas