Friday, January 9, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, JANUARY 9, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

COLD AIR CAME IN IN A RUSH–ZERO AND GUSTING 40 MPH
LOW OF 5 BELOW ZERO YESTERDAY, COLDEST IN 4 YEARS
COLDEST AIR LEAVES IN A HURRY!
TEMPERATURE RISES ALMOST 30 DEGREES IN 24 HOURS
SNOW ARRIVING THIS MORNING

The low temperature of 5 below zero yesterday morning
was the coldest in 4 years or since -7F on January 24, 2011.
The coldest of the cold was over us a sunrise yesterday
morning with -5F at 7 A.M. and a very low dew point of
-16F was recorded before the cold began leaving us.
The cold was in quite a hurry to leave; the  thermometer
rose to 16 degrees in the afternoon yesterday then
fell back to 13 degrees in the early evening before
resuming its rise to 16F again at midnight

Less cold air continued to arrive early this morning
on continuing southwest winds gusting a few times near
30 MPH.  The total temperature rise was 29 degrees from
-5F at 7 A.M. yesterday to 24F at 7 AM this morning.

Light snow advancing from the west began here at the summit
just a few minutes before 9 A.M. Final snowfall ended just
before noon was 0.9 inch.

Today’s Observations:

7 A.M.
Weather: Overcast altostratus with virga, moon dimly visible
during past hour, virga is al quadrants
Temperature: 24F; Dew Point: 17F; Wind: SSW at 18 kts,
Sea-level pressure: 29.93 ins. Hg, falling then more rapidly
Visibility: 15 miles, hazy
6-hr max temp: 24F
6-hr min temp: 17F
24-hr precip.: 0.00 ins
24-hr snowfall: 0.0 ins
BHO SA 1155 E100 OVC 15 134/24/17/2118/993/ MOON DMLY VSB PST HR
VIRGA ALQDS HAZY/ 8/02/ 58038 10024 20017

10 A.M.
Weather: Obscurement snow and fog, moderate snow and
fog occurring, snow began at 8:58 A.M.
Temperature: 22F; Dew Point: 21F; Wind: WSW at 14G22 kts,
Wind: Peak wind at 27 kts from W at 5 mins. past the hour
Sea-level pressure: 29.96 ins. Hg, rising then more rapidly
Visibility: 1/2 mile moderate snow and fog
3-hourly precip: 0.03 in.
3-hourly snowfall: 0.5 in.
BHO SA 1455 W5 X 1/2SF 144/22/21/2514G22/996/ PK WND 2727/05
SB1358 TOTAL NEW SNW 3 HRS 0.5 IN/ 8//// 53010 MANUAL 6003/
ASOS 60002

1 P.M.
Weather: Scattered stratocumulus, stratus fractus, broken altocumulus,
sky mostly clear WSW-N and clearing
Temperature: 23F; Dew Point: 17F; Wind: WSW at 12G21 kts,
Wind: Gust to 25 kts past hour
Sea-level pressure: 29.89 ins. Hg, falling then falling more rapidly
Visibility: 24 miles, except 20 miles E-SE, snow, 45 miles WNW,
distant haze
6-hr max temp: 26F
6-hr min temp: 21F
6-hr precip: 0.08 in.
6 hr snowfall: 0.9 in.
BHO SA 1755 15 SCT E65 BKN 35 123/23/17/2512G21/989/ SKY MSTLY CLR AND
CLRG WSW-N VSBY E-SE 20 SN WNW 45 DSNT HZ SE1659/ TOTAL NEW SNW 6 HRS
0.9 IN GST 25 KTS PST HR/ 8/530 58021 ASOS 60007 MANUAL 6008/ 10026 20021

SUMMARY FOR THURSDAY, JANUARY 8, 2015

TEMPERATURE (DEGREES F)
MAX…..16   NORMAL…..34
MIN…..-5   NORMAL…..18
MEAN…..6   NORMAL…..26

DEPARTURE FROM 30-YEAR NORMAL…………………….-20
TOTAL DEPARTURE FOR THE MONTH…………………….-22 [-3.0 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..59  DEPARTURE……….+14
TOTAL HEATING UNITS FOR THE MONTH………….332  DEPARTURE……….+22
TOTAL HEATING UNITS FOR THE SEASON………..2392  DEPARTURE………-223
TOTAL HEATING UNITS LAST SEASON TO DATE……2652  DIFFERENCE……..-260

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………39  WNW  AT 12:09 A.M. *
ASOS…………………..46  WNW  AT 12:09 A.M.
DAVIS………………….39  WNW  AT 12:07 A,M. RMY N/A
FASTEST MILE FOR YESTERDAY………………..26  WNW  AT 12:33 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..26  WNW  AT 12:46 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….26  NW   AT 12:14 A.M.
AVERAGE WIND SPEED AND DIRECTION………….15.3 WNW
ASOS………………….15.2
DAVIS…………………13.6 W  [260 degrees] * last of several occurrences….

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE…..-0.14
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.18  DEPARTURE…..+0.04
ASOS…………..1.20
TOTAL PRECIPITATION FOR THE YEAR………..1.18  DEPARTURE…..+0.04
ASOS…………..1.20

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……-0.6
TOTAL SNOWFALL FOR THE MONTH…………….3.2  DEPARTURE……-1.3
TOTAL SNOWFALL FOR THE SEASON…………..14.2  DEPARTURE……-6.3

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER-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  16/-5/6/-20/0.00/0.0/…/..              39 WNW RMY N/A

1/9  morning low temp: 16F since midnight; normal low is now 17F

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 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]

RECORDS FOR JANUARY 10
HIGH 54F IN 2000
LOW -7F IN 2004
PRECIP 2.16 INS. IN 1935
SNOWFALL 6.3 INS. IN 1977
PEAK GUST 73e SE IN 1977

TODAY’S REPORT PREPARED BY: Robert Skilling