Tuesday, December 24, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, DECEMBER 24, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

ATTENTION: There will be no discussion posted tomorrow, December 25,
due to the holiday. The next daily discussion will be posted on Thursday,
December 26.

COLDER AND DRIER TODAY…STEADY NW WIND KEEPS TEMPS BELOW FREEZING

After a string of unusually warm days, temperatures dropped
back to around normal on Tuesday thanks to a steady northwest wind
and mostly cloudy skies. Yesterday’s cold front brought 0.74 inch
of rain to the summit – the largest precipitation total since
December 15. The rainfall also brought December’s monthly total back
to a surplus.

Today, skies remained cloudy with multiple layers of altocumulus
until the early afternoon. As a result, the maximum recorded
air temperature through 1PM was 31F (six degrees below normal). Winds
have averaged 10 knots out of the northwest and visibility has ranged
65 and 80 miles. More cold weather is expected tomorrow for Christmas Day.

Today’s Observations:

7 A.M.
Weather: Overcast altocumulus, broken altocumulus, few altocumulus
castellanus distant northeast-east
Temperature: 30F; Dew Point: 24F; Wind: NW at 10 kts,
Sea-level pressure: 30.11 ins. Hg, increasing, then decreasing
Visibility: 80 miles
6-hr. min temp: 30F
24-hr precip: 0.73 inches
BHO SA 1155 E200 BKN 250 OVC 80 195/30/24/3210/011/ FEW ACC DSNT NE-E
8/078 50003 ASOS 70070 MANUAL 70073 10035 20030

10 A.M.
Weather: Two layers of broken altocumulus, stratocumulus later distant
offshore northeast-southeast, few lower cumulus distant south
Temperature: 30F; Dew Point: 18F; Wind: NW at 10 kts,
Sea-level pressure: 30.10 ins. Hg, increasing, then decreasing
Visibility: 80 miles
BHO SA 1455 E160 BKN 250 BKN 80 192/30/19/3110/010/ SC LYR DSNT OFFSHR
NE-SE FEW LWR CU DSNT S/ 8/078 50003

1 P.M.
Weather: Two layers of broken altocumulus, few altocumulus lenticularis
distant west-northwest
Temperature: 31F; Dew Point: 19F; Wind: NW at 10 kts
Sea-level pressure: 30.03 ins. Hg, decreasing, then decreasing more slowly
Visibility: 65 miles
6-hr max temp: 31F
BHO SA 1755 E200 BKN 250 BKN 65 168/31/19/3110/003/ FEW ACSL DSNT W-NW/
8/048 56024 10031 20029

WEATHER SUMMARY FOR MONDAY, DECEMBER 23, 2013

TEMPERATURE (DEGREES F)
MAX…..37    NORMAL…..37
MIN…..32    NORMAL…..21
MEAN….35    NORMAL…..29

DEPARTURE FROM 30-YEAR NORMAL………………….+6
TOTAL DEPARTURE FOR THE MONTH…………………-13 [-0.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..30  DEPARTURE………-6
TOTAL HEATING UNITS FOR THE MONTH………….756  DEPARTURE……..+11
TOTAL HEATING UNITS FOR THE SEASON………..1980  DEPARTURE……..-27
TOTAL HEATING UNITS LAST SEASON TO DATE……1743  DIFFERENCE……+237

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………24 NW  AT  11:50 P.M.
AERO…………………..25 NW  AT  11:50 P.M.
ASOS…………………..25 NW  AT  11:51 P.M.
DAVIS………………….22 WNW AT  11:50 P.M. RMY 25
FASTEST MILE FOR YESTERDAY………………..17 NW  AT  11:55 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..18 NW  AT  11:52 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….16 NW  AT   8:38 P.M.
AVERAGE WIND SPEED AND DIRECTION………….8.2 SSW
ASOS………………….8.1
DAVIS…………………7.4 N [008 degrees] * last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.73  DEPARTURE………….+0.58
ASOS…………..0.70
TOTAL PRECIPITATION FOR THE MONTH……….3.99  DEPARTURE………….+0.28
ASOS…………..3.97
TOTAL PRECIPITATION FOR THE YEAR……….50.59  DEPARTURE………….-1.65
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………….-0.5
TOTAL SNOWFALL FOR THE MONTH…………15.0     DEPARTURE………….+5.8
TOTAL SNOWFALL FOR THE SEASON………..15.2     DEPARTURE………….+3.4

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 58/42/50/+20/0.00/0.0/…/..        28 SSW AERO 29 MPH SSW RMY 30
12/22 63/35/49/+20/…/0.0/…/..         37 SW  AERO 41 MPH SW  RMY 41
12/23 37/32/35/+6/…/0.0/000/00          24 NW  AERO 25 MPH NW  RMY 25

12/24 morning low temp: 30F; the normal low is now 21F

DAILY RECORDS FOR DECEMBER 2013
12/22- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 63F;
surpasses previous record of 62F set in 1994

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

RECORDS FOR DECEMBER 24
HIGH 58 IN 1996
LOW -6 IN 1943
PRECIP 2.21 INS. IN 1994
SNOWFALL 12.3 INS. IN 1961
PEAK GUST 79e MPH SE IN 1941

RECORDS FOR DECEMBER 25
HIGH 62 IN 1889
LOW -11 IN 1980
PRECIP 1.37 INS. IN 2002
SNOWFALL 8.5 INS. IN 2002
PEAK GUST 80 MPH NW IN 1971

TODAY’S REPORT PREPARED BY: Eli Melaas