Sunday, December 22, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, DECEMBER 22, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

NEW RECORD MAX TEMP REACHED DESPITE LACK OF SUN,
CHASED OUT BY BACK DOOR COLD FRONT

This morning was accompanied by strong S-SW winds and record breaking warmth, with a
high of 63.4F occurring before noon eclipsing the previous record of 62F set in 1994.
A back door cold front swept in just after noon, bringing NW winds and causing
temperatures to plummet close to 20 F in the hour before our 1:00 P.M. observation.
Low clouds and thin fog have persisted throughout the day, thickening with the
passing front and reducing visibility to 1/8 mile early in the afternoon.

Today’s Observations:

7 A.M.
Weather: Overcast stratocumulus and cumulus fractus with thin fog
Temperature: 57F; Dew Point: 57F; Wind: SSW at 12 kts,
Sea-level pressure: 29.85 ins. Hg, decreasing then steady
Visibility: 10 miles, thin fog
Visibility: 5 miles N-ENE
6-hr. min temp: 51
24-hr rainfall: Trace
Snow on ground: Trace
BHO SA 1155 30 OVC 10 108/57/57/2112/985/ VSBY 5 N-ENE F/
8/1// 56013 10057 20051

10 A.M.
Weather: Overcast stratocumulus with fog of varying density
Temperature: 62F; Dew Point: 58F; Wind: SW at 21G30 kts,
Wind: Peak Gust: 30 kts SW @ 9:56 A.M.
Sea-level pressure: 29.85 ins. Hg, rising then falling
Visibility: 20 miles, fog
BHO SA 1455 50 OVC 20 108/62/58/2221G30/985/ PK GUST 2330/56
VSBY 10 NW-E F 20 ESE-SSW F- 30 SW-WNW F-/ 8/4// 50005

1 P.M.
Weather: Dense fog with strata drifting over the summit
Temperature: 40F; Dew Point: 39F; Wind: NE at 12 kts,
Sea-level pressure: 29.98 ins. Hg, increasing
Visibility: 1/8 mile
6-hr max temp: 63F
6-hr min temp: 40F
BHO SA 1755 W3 X 1/8F 120/40/39/0612/988/ DNS F W/ STRA DFTNG OVR SMT/
8//// 51012 10063 20040

WEATHER SUMMARY FOR SATURDAY, DECEMBER 21, 2013

TEMPERATURE (DEGREES F)
MAX…..58    NORMAL…..37
MIN…..42    NORMAL…..22
MEAN….50    NORMAL…..30

DEPARTURE FROM 30-YEAR NORMAL…………………+20
TOTAL DEPARTURE FOR THE MONTH…………………-39 [-1.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..15  DEPARTURE……..-20
TOTAL HEATING UNITS FOR THE MONTH………….710  DEPARTURE……..+36
TOTAL HEATING UNITS FOR THE SEASON………..1934  DEPARTURE……..-1
TOTAL HEATING UNITS LAST SEASON TO DATE……1676  DIFFERENCE……+258

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………28 SSW AT  10:18 A.M.
AERO…………………..29 SSW AT  10:20 A.M.
ASOS…………………..30 SSW AT  10:23 A.M.
DAVIS………………….28 S   AT  10:23 A.M. RMY 30
FASTEST MILE FOR YESTERDAY………………..23 SSW AT  5:13  P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..23 S   AT  5:14  P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….22 SSW AT  10:19 A.M.
AVERAGE WIND SPEED AND DIRECTION…………17.4 SSW
ASOS…………………17.0
DAVIS………………..16.4 SSW [202 degrees]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….Trace  DEPARTURE………….-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….3.25  DEPARTURE………….-0.14
ASOS…………..3.27
TOTAL PRECIPITATION FOR THE YEAR……….49.85  DEPARTURE………….-2.07
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………….-0.4
TOTAL SNOWFALL FOR THE MONTH…………15.0     DEPARTURE………….+6.8
TOTAL SNOWFALL FOR THE SEASON………..15.2     DEPARTURE………….+4.4

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 morning low temp: 50F; the normal low is now 22F

DAILY RECORDS FOR DECEMBER 2013
12/22 HIGH TEMP: 63F

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

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

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: Forrest Iwanik