Thursday, December 18, 2014

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, DECEMBER 18, 2014
ALL TIMES ARE IN EASTERN STANDARD TIME

A FEW HOURS OF LIGHT SNOW THIS MORNING
CONSIDERABLE CLOUDINESS PREVAILS DURING DAY

A period light snow melted as it fell in above
freezing temperatures this morning yielding a
couple of hundredths of melted precipitation.

Considerable stratocumulus formed this morning
and soon formed an overcast shutting out the
the sunshine by early afternoon.

Today’s Observations:

7 A.M.
Weather: Overcast nimbostratus, few stratus fractus,
light snow and fog, snow mostly melting as it falls
Temperature: 32F; Dew Point: 32F; Wind: W at 13 kts
Sea-level pressure: 29.75 ins. Hg, rising
Visibility: 4 miles
6-hr max temp: 37F
6-hr min temp: 32F
6-hr precip:   0.01 in.
24-hr precip:  0.02 in.
24-hr snowfall: trace
BHO SA 1155 E26 OVC 4S-F 074/32/32/2713/975/ FEW STFRA
SNW MSTLY MELTING AS IT FALL TOTAL NEW SNW TRACE/
8/72/ 53013 MANUAL 6001/ ASOS 60001 MANUAL 70002 ASOS 70003
10037 20032

10 A.M.
Weather: Scattered altostratus, broken altocumulus,
cumulus/stratocumulus distant all quadrants
Temperature: 36F; Dew Point: 33F; Wind: W at 14 kts
Sea-level pressure: 29.78 ins. Hg, rising
Visibility: 45 miles
3-hr precip: 0.01
3-hr snowfall: trace
BHO SA 1455 50 SCT E75 BKN 45 085/36/33/2814/978/ CU/SC DSNT ALQDS
DSNT HZ TRACE SNW PST 3 HRS/ 8/870 51011 ASOS 60001 MANUAL 6001/

1 P.M.
Weather: Overcast stratocumulus, lower cumulus distant NN-NE
and distant S, numerous bright spots in overcast, mountain in cloud 70 NW
Temperature: 39F; Dew Point: 29F; Wind: WNW at 15G23 kts
Sea-level pressure: 29.76 ins. Hg, falling
Visibility: 75 miles, mountain in cloud 70 NW
6-hr max temp: 40F
6-hr min temp: 32F
6-hr precip: 0.01
BHO SA 1755 E30 OVC 75 079/39/29/2915G23/976/ FEW LWR CU DSNT
NNE-NE AND DSNT S MTN INCLD 70 NW NEW SNW PST 6 HRS TRACE/
8/8// 55006 ASOS 60001 MANUAL 6001/ 10040 20032

SUMMARY FOR WEDNESDAY, DECEMBER 17, 2014

TEMPERATURE (DEGREES F)
MAX…..45   NORMAL…..38
MIN…..37   NORMAL…..23
MEAN….41   NORMAL…..31

DEPARTURE FROM 30-YEAR NORMAL……………………+10
TOTAL DEPARTURE FOR THE MONTH……………………+33 [+1.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..24  DEPARTURE……….-11
TOTAL HEATING UNITS FOR THE MONTH………….499  DEPARTURE……….-34
TOTAL HEATING UNITS FOR THE SEASON………..1658  DEPARTURE………-137
TOTAL HEATING UNITS LAST SEASON TO DATE……1823  DIFFERENCE……..-165

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………27 W   AT 10:06 P.M.
ASOS…………………..28 WNW AT  4:31 P.M.
DAVIS………………….27 WNW AT  8:41 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………..20 W   AT 10:10 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..21 W   AT 10:10 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….18 W   AT  8:42 P.M.
AVERAGE WIND SPEED AND DIRECTION………..12.3 WNW
ASOS………………..12.6
DAVIS……………….10.8 NW (310 degrees)
* Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M… 0.02  DEPARTURE…..-0.14
ASOS…………..0.03
TOTAL PRECIPITATION FOR THE MONTH……….5.84  DEPARTURE…..+3.06
ASOS…………..6.00
TOTAL PRECIPITATION FOR THE YEAR……….53.60  DEPARTURE…..+2.29
ASOS………….54.19

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………trace DEPARTURE……-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.6  DEPARTURE……-5.7
TOTAL SNOWFALL FOR THE SEASON……………9.3  DEPARTURE……+0.4

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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

12/1  63/37/50/+13/0.01/0.0/391/70             28 WNW RMY 31
12/2  37/30/34/-2/0.10/T/000/00                26 E   RMY 29
12/3  49/34/42/+6/0.31/0.0/000/00              40 W   RMY 43
12/4  41/27/34/-1/0.00/0.0/505/91              29 WNW RMY N/A
12/5  42/23/33/-2/0.12/0.0/382/69              21 E   RMY 22
12/6  43/36/40/+5/0.99/0.0/000/00              25 NNW RMY N/A
12/7  36/18/27/-7/…./0.0/193/35              31 N   RMY 34
12/8  25/16/21/-13/0.01/0.1/000/00             24 N   RMY N/A
12/9  48/25/37/+3/3.23/0.0/000/00              48 ENE RMY 52
12/10 47/35/41/+8/0.43/0.0/000/00              35 NNE RMY 37
12/11 35/29/32/-1/0.05/0.5/000/00              27 SW  RMY 27
12/12 36/26/31/-2/0.00/0.0/230/42              23 WNW RMY 25
12/13 40/27/34/+2/0.00/0.0/191/35              28 NW  RMY 28
12/14 43/28/36/+4/0.00/0.0/…/..              20 NW  RMY 20
12/15 41/28/35/+3/0.00/0.0/…/..              17 NW  RMY 17
12/16 42/33/38/+7/T/T/…/..                   17 E   RMY N/A
12/17 45/37/41/+10/0.42/0.0…/..              27 W   RMY N/A

12/18 morning low temp: 32F since midnight; the normal low is now 23F

DAILY RECORDS FOR DECEMBER 2014:

-DAILY PRECIPITATION RECORD FOR DECEMBER 9 2014
Old record of 1.51 inches set in 1952,
replaced with new record of 3.23 inches.

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

RECORDS FOR DECEMBER 18
HIGH 59 IN 1928
LOW -11 IN 1919
PRECIP 1.44 INS. IN 1915
SNOWFALL 7.0 INS. IN 1904
PEAK GUST 76e W IN 1978

RECORDS FOR DECEMBER 19
HIGH 59 IN 1899
LOW -1 IN 1919
PRECIP 2.06 INS. IN 1986
SNOWFALL 14.1 INS. IN 1945
PEAK GUST 68 NE IN 1986

TODAY’S REPORT PREPARED BY: Robert Skilling