Thursday, January 8, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, JANUARY 8, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

ARCTIC AIR INVADES NEW ENGLAND

A cold front crossed the region yesterday afternoon, bringing with it snow
squalls and a bitterly cold air mass.  0.3 inches of snow from yesterday’s
squalls were recorded here at the summit, with 0.01 inches of melted
precipitation.  Temperatures, which were already well below normal, fell
as the front passed, from a high of 22F yesterday to a low of -5F this
morning, the coldest reading since -7F on January 24, 2011.  We still fell
a few degrees short of the record for today’s date, which is -8F set in 1968.

In addition to the cold, the wind picked up significantly yesterday afternoon
and evening, with a peak gust of 43mph and sustained winds of 20-25mph.
This morning, with a temperature of -5F and a sustained wind of 20mph, the
wind chill value dropped to nearly -30F.  It has remained very cold into
this afternoon, with the temperature only rising to 14F by 1:00 P.M.  The
skies have been mostly clear today, with just a few ocean-effect clouds
mainly to our east.  The visibility had improved to 70 miles by mid-morning
and has remained around that value for the rest of the day.

Today’s Observations:

7 A.M.
Weather: Clear, stratocumulus distant NNE-SSE, wind chill -26F
Temperature: -5F; Dew Point: -15F; Wind: WNW at 13 kts,
Wind: Peak wind 26 kts WNW at 6:02 A.M.
Sea-level pressure: 30.26 ins. Hg, rising
Visibility: 40 miles, distant haze
6-hr max temp: -1F
6-hr min temp: -5F
24-hr precip.: 0.01 ins
24-hr snowfall: 0.3 ins
BHO SA 1155 CLR 40 248/-5/-15/2913/026/ SC DSNT NNE-SSE DSNT HZ
NEW SNW PST 24 HRS 0.3 INS PK WND 2926/02 WND CHILL -26F/ 8/500 52029
ASOS 70001 MANUAL 70001 11001 21005

10 A.M.
Weather: Clear, stratocumulus distant NE-SSE
Temperature: 3F; Dew Point: -13F; Wind: W at 14 kts
Sea-level pressure: 30.31 ins. Hg, rising then falling
Visibility: 70 miles
BHO SA 1455 CLR 70 265/3/-13/2814/031/ SC DSNT NE-SSE/ 8/500 50017

1 P.M.
Weather: Clear, few stratocumulus distant WNW-NW and NE-S
Temperature: 14F; Dew Point: -2F; Wind: WNW at 12 kts
Sea-level pressure: 30.26 ins. Hg, falling then falling more rapidly
Visibility: 70 miles
6-hr max temp: 14F
6-hr min temp: -5F
BHO SA 1755 CLR 70 247/14/-2/2812/026/ FEW SC DSNT WNW-NW AND NE-S/
8/500 58018 10014 21005

SUMMARY FOR WEDNESDAY, JANUARY 7, 2015

TEMPERATURE (DEGREES F)
MAX…..22   NORMAL…..34
MIN……1   NORMAL…..18
MEAN….12   NORMAL…..26

DEPARTURE FROM 30-YEAR NORMAL…………………….-14
TOTAL DEPARTURE FOR THE MONTH……………………..-2 [-0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..53  DEPARTURE……….+14
TOTAL HEATING UNITS FOR THE MONTH………….273  DEPARTURE………..+2
TOTAL HEATING UNITS FOR THE SEASON………..2333  DEPARTURE………-242
TOTAL HEATING UNITS LAST SEASON TO DATE……2599  DIFFERENCE……..-266

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………43  WNW  AT  6:42 P.M.
ASOS…………………..45  WNW  AT  5:16 P.M.
DAVIS………………….46  WNW  AT  6:42 P.M. RMY 47
FASTEST MILE FOR YESTERDAY………………..34  WNW  AT  6:44 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..33  WNW  AT  6:44 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….32  WNW  AT  6:30 P.M.
AVERAGE WIND SPEED AND DIRECTION………….15.5 WNW
ASOS………………….16.2
DAVIS…………………13.1 WNW [285 degrees]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.01  DEPARTURE…..-0.13
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….1.18  DEPARTURE…..+0.18
ASOS…………..1.20
TOTAL PRECIPITATION FOR THE YEAR………..1.18  DEPARTURE…..+0.18
ASOS…………..1.20

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.3  DEPARTURE……-0.2
TOTAL SNOWFALL FOR THE MONTH…………….3.2  DEPARTURE……-0.7
TOTAL SNOWFALL FOR THE SEASON…………..14.2  DEPARTURE……-7.6

PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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

1/1  31/18/25/-2/0.00/0.0/…/..              29 SSW RMY 30
1/2  37/26/32/+5/0.00/0.0/…/..              35 WSW RMY 38
1/3  34/21/28/+2/0.67/2.5/…/..              25 SE  RMY 26
1/4  51/33/42/+16/0.48/0.0/000/00             30 SSW RMY N/A
1/5  46/13/30/+4/0.00/0.0/…/..              48 W   RMY 54
1/6  15/10/13/-13/0.02/0.4/…/..             29 W   RMY N/A
1/7  22/01/12/-14/0.01/0.3/…/..             43 WNW RMY 47

1/8 morning low temp: -5F since midnight; normal low is now 18F

DAILY RECORDS FOR JANUARY 2015
None so far.

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

RECORDS FOR JANUARY 8
HIGH 65F IN 2008
LOW -8F IN 1968
PRECIP 1.70 INS. IN 1958,1979
SNOWFALL 12.5 INS. IN 1996
PEAK GUST 77 MPH NNW IN 1958

RECORDS FOR JANUARY 9
HIGH 62F IN 1937
LOW -9F IN 1968
PRECIP 3.00 INS. IN 1956
SNOWFALL 10.0 INS. IN 1904
PEAK GUST 101e MPH SE IN 1978 [RECORD FOR MONTH]

TODAY’S REPORT PREPARED BY: Jonathan O’Brien