Saturday, December 22, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 22, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUDY DAY WITH PRESSURE BEGINNING TO RISE AND TEMPERATURES
DROPPING CLOSER TO NORMAL…

After yesterday’s unusually warm and windy day, today has been
a bit more calm with winds only gusting to 36 miles per hour so
far. This is significantly lighter than yesterday’s peak gust
of 60 miles per hour. Since midnight, wind speeds have dropped,
and shifted direction to the west north west. This wind is bringing
cooler air into the area, and the temperature has continued to drop
as the day progresses. The high temperature for today was observed
at midnight at about 54F. This is 17 degrees above our normal high
temperature of 37F. Between 11 A.M. and noon, the temperature
dropped over 8 degrees from about 51 F to about 43F. This corresponds
with a rapid shift in wind speed and direction from about 16 miles per
hour from the SSW to about 34 miles per hour from the WNW just past the
elevon o’clock hour. Since then, the observed wind speed has dropped
back to about 20 miles per hour, and is  persisting from the WNW. Passing
rain showers have been making appearances from the late morning through
the early afternoon. Visibility was obstructed throughout the day
with distant haze and fog being present, but during the 12 P.M. hour,
the fog lifted, leaving for some nice visibility at the 1 o’clock
observation, of 80 miles with Mount Monadnock being clearly visible.

Houghton’s Pond and Ponkepaug Pond have both thawed overnight last night.

Today’s Observations:

7 A.M.
Weather: Fog, overcast stratus
Temperature: 50F; Dew Point: 50F; Wind: SSW at 16G22 kts
Sea-level pressure: 29.24 ins. Hg, falling then rising
Visibility: 10 miles
6-hr Max temp: 54F
6-hr Min temp: 50F
24-hr Precip: 1.02 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 E13 OVC 10F 903/50/50/2016G22/924/ FOG 8/6// 55001
70102 10054 20050

10 A.M.
Weather: Distant fog in all directions, overcast stratus
Temperature: 51F; Dew Point: 48F; Wind: SSW at 16 kts
Sea-level pressure: 29.27 ins. Hg, rising then steady
Visibility: 15 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 E16 OVC 15 912/51/48/2016/927/ DSNT FOG ALQDS
8/6// 50009

1 P.M.
Weather: Broken stratus, few cumulus in all directions
Temperature: 41F; Dew Point: 33F; Wind: E at 13 kts
Sea-level pressure: 29.31 ins. Hg, rising, then more slowly
Visibility: 80 miles
6-hr Max temp: 52F
6-hr Min temp: 41F
6-hr Precip: 0.02 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 E36 BKN 80 924/41/33/1013/931/ FEW CU ALQDS 8/600
6002/ 53012 10052 20041

SUMMARY FOR FRIDAY, DECEMBER 21, 2018

TEMPERATURE (DEGREES F)
MAX…..62   NORMAL…..37
MIN…..43   NORMAL…..22
MEAN….53   NORMAL…..30

DEPARTURE FROM 30-YEAR NORMAL…………………..+23
TOTAL DEPARTURE FOR THE MONTH…………………..+3 [-0.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..12   DEPARTURE……..-23
TOTAL HEATING UNITS FOR THE MONTH………….668   DEPARTURE………-6
TOTAL HEATING UNITS FOR THE SEASON………..1988   DEPARTURE……..+53
TOTAL HEATING UNITS LAST SEASON TO DATE……1645   DIFFERENCE……+343

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..60 SSE AT 3:35  P.M.
AERO…………………….62 SSE AT 3:35  P.M.
ASOS…………………….61 S   AT 12:50 P.M.
DAVIS……………………62 S   AT 10:00 A.M. RMY 63
FASTEST MILE FOR YESTERDAY………………….44 S   AT 3:30  P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….43 SSE AT 3:33  P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………44 S   AT 3:33  P.M.
AVERAGE WIND SPEED AND DIRECTION…………..24.3 SSE
ASOS…………………..22.5
DAVIS………………….23.4 SSE [166 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….1.02  DEPARTURE…….+0.86
ASOS…………..0.93
TOTAL PRECIPITATION FOR THE MONTH……….3.10  DEPARTURE…….-1.16
ASOS…………..3.74 *
TOTAL PRECIPITATION FOR THE YEAR……….66.47  DEPARTURE……+14.74
ASOS………….69.37 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.4
TOTAL SNOWFALL FOR THE MONTH…………….0.1  DEPARTURE……..-8.1
TOTAL SNOWFALL FOR THE SEASON……………7.7  DEPARTURE……..-3.1

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 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

12/01 41/28/35/-2/0.00/0.0/391/70          20 NNW AERO 18 NNW RMY N/A
12/02 52/35/44/+8/1.04/0.0/000/00          28 ESE AERO 25 ESE RMY 27
12/03 54/38/46/+10/0.00/0.0/178/32         35 W   AERO 35 W   RMY 38
12/04 38/23/31/-4/0.00/0.0/516/93          30 WNW AERO 31 WNW RMY 33
12/05 33/18/26/-9/0.00/0.0/432/78          16 NNW AERO 15 NNW RMY N/A
12/06 37/24/31/-4/0.00/0.0/354/64          29 W   AERO 28 W   RMY 30
12/07 37/21/29/-5/0.00/0.0/…/..          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/…/..         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/…/..          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/…/..          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/…/..          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/…/..          30 NW  AERO 29 NW  RMY M
12/13 31/16/24/-8/0.00/0.0/…/..          16 NNE AERO 12 SE  RMY N/A
12/14 46/28/37/+5/0.00/0.0/…/..          28 SSW AERO 28 SSW RMY 29
12/15 49/33/43/+11/0.04/0.0/…/..         28 NE  AERO 27 NE  RMY 30
12/16 40/37/39/+8/…./0.0/…/..          38 NE  AERO 38 NE  RMY 40
12/17 37/32/35/+4/…./0.0/…/..          39 NNE AERO 37 NNE RMY N/A
12/18 34/20/27/-4/0.02/0.1/…/..          48 NW  AERO 55 NW  RMY 48
12/19 38/17/28/-2/0.00/0.0/…/..          23 WNW AERO 23 WNW RMY N/A
12/20 47/30/39/9/0.00/0.0/…/..           23 SW  AERO 22 SW  RMY N/A
12/21 62/43/53/+23/…./0.0/…/..         60 SSE AERO 62 SSE RMY 63

12/22 Low temp since midnight is 49F; normal low is 22F

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

RECORDS FOR DECEMBER 22
HIGH 63 IN 2013
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998

RECORDS FOR DECEMBER 23
HIGH 62 IN 1990
LOW -1 IN 1989
PRECIP 1.70 INS. IN 1947
SNOWFALL 11.9 INS. IN 1947
PEAK GUST 67 SSE IN 2004

TODAY’S REPORT PREPARED BY: Samantha Richard