Saturday, December 21, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, DECEMBER 21, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURES REACHING MID 50S BY EARLY AFTERNOON,
WARMING TREND CONTINUES WITH SSW-SW WINDS

The snow cover is melting rapidly from 9 inches yesterday to
4 inches at 0700e this morning, with further melting continuing
through the weekend.

Record maximum temps:
12/21 = 60 in 1957
12/22 – 62 in 1994
12/23 = 62 in 1990

Today’s Observations:

7 A.M.
Weather: Scattered dense cirrus, Overcast cirrostratus and
cirrus fibratus, few altocumulus distant NW-N, thin fog, hazy
Temperature: 44F; Dew Point: 41F; Wind: SSW at 16 kts,
Sea-level pressure: 29.96 ins. Hg, increasing unsteadily
Visibility: 20 miles, thin fog, hazy
6-hr. min temp: 42F
Snow on ground: 4 inches
BHO SA 1155 200 SCT 250 –OVC 20 144/44/41/2116/996/ FEW AC DSNT NW-N
THN F HAZY/ 8/038 4/004 52007 10044 20042

10 A.M.
Weather: Broken altocumulus, overcast cirrostratus, few cirrocumulus
lenticularis distant to the southeast
Temperature: 48F; Dew Point: 43F; Wind: SSW at 15G20 kts,
Sea-level pressure: 29.98 ins. Hg, increasing more rapidly
Visibility: 25 miles, hazy
BHO SA 1455 E90 BKN 250 OVC 25 154/48/43/2015G20/998/ FEW CCSL DSNT SE
VSBY SE-S 30 NW 20 NNE-NE 20 HAZY/ 8/078 53010

1 P.M.
Weather: Overcast cirrostratus and cirrus fibratus, few altocumulus
distant to the south-southeast through north-northeast.
Temperature: 52F; Dew Point: 45F; Wind: SSW at 17 kts,
Sea-level pressure: 29.91 ins. Hg, decreasing then more slowly
Visibility: 30 miles, hazy
6-hr max. temp. 53F
BHO SA 1755 E220 OVC 30 128/52/45/2017/991/ FEW AC DSNT SSE-NNE
SUN DMLY VSBL HAZY/ 8/078 56026 10053 20044

WEATHER SUMMARY FOR FRIDAY, DECEMBER 20, 2013

TEMPERATURE (DEGREES F)
MAX…..52    NORMAL…..38
MIN…..34    NORMAL…..22
MEAN….43    NORMAL…..30

DEPARTURE FROM 30-YEAR NORMAL…………………+13
TOTAL DEPARTURE FOR THE MONTH…………………-59 [-3.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..22  DEPARTURE……..-13
TOTAL HEATING UNITS FOR THE MONTH………….695  DEPARTURE……..+57
TOTAL HEATING UNITS FOR THE SEASON………..1919  DEPARTURE……..+19
TOTAL HEATING UNITS LAST SEASON TO DATE……1655  DIFFERENCE……+264

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………26 SSW AT  5:12 P.M. *
AERO…………………..29 SSW AT  5:03 P.M.
ASOS…………………..28 SSW AT  5:04 P.M.
DAVIS………………….27 SSW AT  5:03 P.M. RMY 29
FASTEST MILE FOR YESTERDAY………………..23 SSW AT  1:03 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..23 SSW AT  1:05 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….22 SSW AT  1:04 P.M.
AVERAGE WIND SPEED AND DIRECTION…………14.0 SSW
ASOS…………………14.1
DAVIS………………..13.0 SSW [196 degrees] * Last of several occurrences.

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE………….-0.16
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….3.25  DEPARTURE………….+0.11
ASOS…………..3.27
TOTAL PRECIPITATION FOR THE YEAR……….49.85  DEPARTURE………….-1.92
ASOS…………..N/A**
** ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…….0.0     DEPARTURE………….-0.6
TOTAL SNOWFALL FOR THE MONTH…………15.0      DEPARTURE………….+7.2
TOTAL SNOWFALL FOR THE SEASON………..15.2     DEPARTURE………….+4.8

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized

12/1  45/30/38/+1/0.28/T/000/00           22 SSE AERO 23 MPH SSE RMY 23
12/2  38/34/36/0/T/0.0/000/00             15 NW  AERO 15 MPH NW  RMY 16
12/3  45/32/39/+3/0.00/0.0/284/51         18 NNW AERO 18 MPH NNW RMY 20
12/4  43/29/36/+1/0.00/0.0/389/70         21 WNW AERO 21 MPH WNW RMY 21
12/5  53/38/46/+11/0.02/0.0/000/00        36 S   AERO 40 MPH S   RMY 39
12/6  55/33/44/+9/0.38/T/000/00           25 SSW AERO 28 MPH SSW RMY N/A
12/7  40/26/33/-1/0.12/T/287/52           23 NW  AERO 25 MPH NW  RMY N/A
12/8  30/22/26/-8/T/T/039/07              25 NW  AERO 27 MPH NW  RMY N/A
12/9  41/25/33/-1/0.35/0.6/000/00         28 E   AERO 28 MPH E   RMY 24
12/10 33/21/27/-6/0.14/2.1/000/00         28 W   AERO 28 MPH W   RMY 28
12/11 28/19/24/-9/0.00/0.0/345/63         27 SW  AERO 28 MPH SW  RMY 27
12/12 23/14/19/-14/0.00/0.0/542/99        28 WNW AERO 31 MPH NW  RMY 30
12/13 28/14/21/-11/0.00/0.0/405/74        31 W   AERO 32 MPH W   RMY 33
12/14 28/9/19/-13/0.45/4.8/000/00         30 E   AERO 26 MPH E   RMY N/A
12/15 36/21/29/-3/0.98/2.0/000/00         48 NE  AERO 50 MPH NE  RMY 51
12/16 27/14/21/-10/0.00/0.0/529/97        36 W   AERO 37 MPH W   RMY N/A
12/17 23/7/15/-16/0.53/5.5/104/19         28 N   AERO 30 MPH N   RMY 28
12/18 32/15/24/-7/0.00/0.0/436/80         29 WNW AERO 30 MPH NW  RMY 29
12/19 42/22/32/+2/0.00/0.0/425/78         38 SW  AERO 44 MPH SW  RMY 42
12/20 52/34/43/+13/0.00/0.0/…/..        26 SSW AERO 29 MPH SSW RMY 29

12/21 morning low temp: 42F; the normal low is now 22F

DAILY RECORDS FOR DECEMBER 2013
None so far.

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

RECORDS FOR DECEMBER 21
HIGH 60 IN 1957
LOW -10 IN 1942
PRECIP 2.01 INS. IN 1946
SNOWFALL 11.4 INS. IN 1954
PEAK GUST 77 MPH SSE IN 1957

RECORDS FOR DECEMBER 22
HIGH 62 IN 1994
LOW -5 IN 1921
PRECIP 1.52 INS. IN 1975
SNOWFALL 8.8 INS. IN 1975
PEAK GUST 62 MPH WNW IN 1998

TODAY’S REPORT PREPARED BY: Mike Iacono / Brian Fitzgerald