Saturday, December 29, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 29, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEARING SKY WITH INCREASING VISIBILITY THROUGHOUT THE DAY….

Humidity has been falling throughout the day, allowing for haze to
lessen and visibility to increase. At 7 A.M., visibility was 40 miles
with a distant haze, which then increased to 80 miles at the 10 o’clock
observation, and has persisted through the 1 o’clock observation.
Temperatures have been unsteady throughout the day, dropping from
midnight until mid-morning, with a high so far today reached of
53F at midnight, and a low so far of 44F observed between the 8
and 10 o’clock observations. Since then, temperatures have increased
slightly to about 46F. This is unseasonably warm, with a normal high
temperature for today of 35F and a normal daily low of 27F.

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus, scattered cirrus, few cumulus,
distant haze in all directions
Temperature: 45F; Dew Point: 45F; Wind: WSW at 16G22 kts
Sea-level pressure: 29.76 ins. Hg, falling then rising
Visibility: 40 miles
6-hr Max temp: 53F
6-hr Min temp: 49F
24-hr Precip: 0.42 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 30 SCT 250 SCT 40 077/45/45/2416G22/976/ FEW CU SW-WSW DSNT HZ
ALQDS/ 8/401 70042 53006 10053 20049

10 A.M.
Weather: Clear, few cumulus SW-NW, few stratocumulus in all directions,
few cirrus SE-S
Temperature: 45F; Dew Point: 33F; Wind: WSW at 13G20 kts
Sea-level pressure: 29.84 ins. Hg, steady
Visibility: 80 mile
3-hr Precip: 0.00 ins.
BHO SA 1455 CLR 80 105/45/33/2913G20/984/ FEW CU SW-NW FEW SC ALQDS FEW CI
SE-S 8/401 51028

1 P.M.
Weather: Scattered stratocumulus, scattered cirrus distant haze S-N
Temperature: 46F; Dew Point: 32F; Wind: WNW at 12G26 kts
Peak Wind: WNW 30 MPH (26 KTS) at 12:48 P.M.
Sea-level pressure: 29.83 ins. Hg, decreasing then increasing
Visibility: 80 mile
6-hr Max temp: 50F
6-hr Min temp: 44F
6-hr Precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1755 40 SCT 250 SCT 80 100/46/32/2912G26/983/ DSNT HZ S-N/
8/401 55005 10050 20044

SUMMARY FOR FRIDAY, DECEMBER 28, 2018

TEMPERATURE (DEGREES F)
MAX…..54   NORMAL…..36
MIN…..30   NORMAL…..20
MEAN….42   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL…………………..+14
TOTAL DEPARTURE FOR THE MONTH…………………..+41 [+1.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..23   DEPARTURE……..-14
TOTAL HEATING UNITS FOR THE MONTH………….886   DEPARTURE……..-44
TOTAL HEATING UNITS FOR THE SEASON………..2206   DEPARTURE……..+15
TOTAL HEATING UNITS LAST SEASON TO DATE……1945   DIFFERENCE……+261

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..44 SSW AT 1:07 P.M.
AERO…………………….MISSING
ASOS…………………….46 SSW AT 1:08 P.M.
DAVIS……………………51 WSW AT 1:08 P.M. RMY 47
FASTEST MILE FOR YESTERDAY………………….33 SSW AT 1:06 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….33 S   AT 1:02 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………31 SSW AT 1:10 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..18.2 SSW
ASOS…………………..17.4
DAVIS………………….17.4 S [190 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.42  DEPARTURE…….+0.28
ASOS…………..0.44
TOTAL PRECIPITATION FOR THE MONTH……….3.55  DEPARTURE…….-0.92
ASOS…………..4.22 *
TOTAL PRECIPITATION FOR THE YEAR……….66.92  DEPARTURE……+14.11
ASOS………….69.85 *
* ASOS MONTHLY AND ANNUAL PRECIPITATION IS SUSPECT

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.1  DEPARTURE…….-11.7
TOTAL SNOWFALL FOR THE SEASON……………7.7  DEPARTURE……..-6.7

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/-5/0.00/0.0/546/99          29 NW  AERO 29 NW  RMY 32
12/08 27/15/21/-13/0.00/0.0/518/94         28 NW  AERO 27 NW  RMY 29
12/09 34/17/26/-8/0.00/0.0/391/71          23 SSW AERO 21 SSW RMY 22
12/10 36/22/29/-4/0.00/0.0/544/99          24 NNW AERO 23 NNW RMY 22
12/11 36/17/27/-6/0.00/0.0/543/99          16 WSW AERO 14 WSW RMY N/A
12/12 35/18/27/-6/0.00/0.0/471/86          30 NW  AERO 29 NW  RMY M
12/13 31/16/24/-8/0.00/0.0/088/16          16 NNE AERO 12 SE  RMY N/A
12/14 46/28/37/+5/0.00/0.0/399/73          28 SSW AERO 28 SSW RMY 29
12/15 49/33/43/+11/0.04/0.0/000/00         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 54/31/43/+14/…./0.0/…/..         41 W   AERO 45 W   RMY 43
12/23 38/27/33/+4/0.00/0.0/…/..          30 WNW AERO 32 WNW RMY N/A
12/24 34/27/31/+2/0.01/T/…/..            21 W   AERO 21 W   RMY N/A
12/25 35/23/29/+1/0.00/0.0/…/..          28 NW  AERO 28 NW  RMY 29
12/26 36/20/28/0/0.00/0.0/…/..           24 NW  AERO 24 NW  RMY 25
12/27 35/26/31/+3/0.00/0.0/…/..          23 NW  AERO 22 NW  RMY N/A
12/28 54/30/42/+14/…./…/0.0/.. 44 SSW AERO M  M   RMY 47

12/29 Low temp since midnight is 44F; normal low is 20F

DAILY RECORDS FOR DECEMBER 2018

12/21/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 62F,
BREAKS PREVIOUS RECORD OF 60F SET IN 1957

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

RECORDS FOR DECEMBER 29
HIGH 72 IN 1984
LOW -19 IN 1933 (RECORD FOR DECEMBER)
PRECIP 1.91 INS. IN 1945
SNOWFALL 18.4 INS. IN 1945
PEAK GUST 95 MPH S IN 1966 (RECORD FOR DECEMBER)

RECORDS FOR DECEMBER 30
HIGH 60 IN 1984
LOW -18 IN 1933
PRECIP 1.48 INS. IN 1891
SNOWFALL 7.5 INS. IN 1956
PEAK GUST 81 MPH WNW IN 1962

TODAY’S REPORT PREPARED BY: Samantha Richard/ Nick Rousseau