Monday, December 28, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, DECEMBER 28, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPS DIP BELOW FREEZING THIS MORNING,
FIRST MEASURABLE SNOW ON THE WAY

Yesterday’s maximum temperature of 52F and minimum of 35F
added another +16 degrees of warmth above normal as the
likely warmest December on record begins to come to an end.
Temperatures are now averaging 13.4 degrees F above normal
per day this month.

Two separate rain events yesterday brought 0.27 inches of
new precipitation total, adding to a slightly drier than
normal month of December. Precipitation is now 1.25 inches
below normal for the month, and 10.37 inches below normal
for the year. Snow is now 11.2 inches below normal for the
month and 13.8 inches below normal for the season.

Temperatures fell steadily after a cold front passage
last evening, reaching the upper 20s by mid morning today.
Today’s daily normal minimum temperature is 20F.

Clearing skies this morning have allowed for excellent
visibility and blue skies, and by this afternoon’s 1:00 PM EST
observation visibility was 80 miles in all directions.

BHO Largest December Daily Temperature Departure, deg F (1885-2015):

1) +35 on 29 Dec 1984 (72/51/62)
2) +30 on 25 Dec 2015 (64/52/58)
3) +29 on 23 Dec 1990 (62/53/58)
+29 on 24 Dec 2015 (67/48/58)
5) +27 on 31 Dec 1965 (62/45/54)
+27 on 22 Dec 1990 (58/53/56)
7) +26 on 27 Dec 1949 (57/51/54)
+26 on 9 Dec 1966 (68/52/60)
+26 on 6 Dec 2001 (70/52/61)

(Thanks to Mike Iacono for compiling these statistics.)

So far this season, there has been no measurable snow on Blue Hill.
This season is now the fourth latest on record for the first
occurrence of measurable snowfall.

BHO Latest First Measurable Snowfall, (1885-2014)

1) January  13, 2000  (7.0 inches)
2) January   1, 1954  (0.8 inches)
3) December 29, 1941  (0.4 inches)
4) December 22, 1998  (0.6 inches)
5) December 16, 1973  (0.4 inches)
6) December 15, 1891  (0.3 inches)

Today’s Observations:

7 A.M.
Weather: Scattered stratocumulus, broken altocumulus,
broken cirrus, few altocumulus lenticularis distant NE
Temperature: 31F; Dew Point: 22F; Wind: NNW @ 17G28 kts
Peak Wind: 28 knots N at 6:47 AM EST
Sea-level pressure: 30.32 ins. Hg, rising rapidly
Visibility: 75 miles
6-hr Max temp: 33F
6-hr Min temp: 30F
24-hr precip: 0.11 ins.
BHO SA 1155 40 SCT E140 BKN 200 BKN 75 267/31/22/3417G28/032/
FEW ACSL DSNT NE PRESRR PK WND 3528/47/ 8/531 53039
ASOS 70010 MANUAL 70011 10033 20030

10 A.M.
Weather: Scattered altocumulus, scattered cirrus,
few stratocumulus in all directions
Temperature: 29F; Dew Point: 14F; Wind: N @ 16G26 kts,
Peak Wind: 26 knots N at 9:45 AM EST
Sea-level pressure: 30.46 ins. Hg, rising rapidly
Visibility: 75 miles
BHO SA 1455 SCT 160 SCT 250 75 315/29/14/3516G26/046/
FEW SC ALQDS PRESRR PK WND 3626/45/ 8/531 51048

1 P.M.
Weather: Scattered cirrus, few stratocumulus NNE-WSW
Temperature: 32F; Dew Point: 16F; Wind: N @ 8G16 kts
Sea-level pressure: 30.50 ins. Hg, rising, then more quickly
Visibility: 80 miles
6-hr Max temp: 32F
6-hr Min temp: 29F
BHO SA 1755 250 SCT 80 327/32/16/3508G16/050/
FEW SC NNE-WSW/ 8/501 53012 10032 20029

SUMMARY FOR SUNDAY, DECEMBER 27, 2015

TEMPERATURE (DEGREES F)
MAX…..52   NORMAL…..36
MIN…..35   NORMAL…..20
MEAN….44   NORMAL…..28

DEPARTURE FROM 30-YEAR NORMAL…………………+16
TOTAL DEPARTURE FOR THE MONTH………………..+368  [+13.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..21   DEPARTURE………-16
TOTAL HEATING UNITS FOR THE MONTH………….522   DEPARTURE……..-370
TOTAL HEATING UNITS FOR THE SEASON………..1524   DEPARTURE……..-630
TOTAL HEATING UNITS LAST SEASON TO DATE……1919   DIFFERENCE…….-395

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….36  NW  AT 10:32 P.M.
ASOS……………………37  NW  AT 10:32 P.M.
DAVIS…………………..31  NNW AT 10:32 P.M. RMY 33
FASTEST MILE FOR YESTERDAY…………………28  NW  AT 10:32 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………26  NW  AT 10:33 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..24  NNW AT 10:32 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.6 NNW
ASOS…………………..10.4
DAVIS………………….8.5 NNW [046 Deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.11  DEPARTURE……-0.03
ASOS……………0.10
TOTAL PRECIPITATION FOR THE MONTH………..3.07  DEPARTURE……-1.25
ASOS……………3.09
TOTAL PRECIPITATION FOR THE YEAR………..42.49  DEPARTURE…..-10.37
ASOS…………….N/A ***
*** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.5
TOTAL SNOWFALL FOR THE MONTH…………….0.0  DEPARTURE……-11.2
TOTAL SNOWFALL FOR THE SEASON………….TRACE  DEPARTURE……-13.8

PRELIMINARY CLIMATE SUMMARY FOR DECEMBER CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

12/1  42/30/36/-1/…./0.0/000/00           19 NNE RMY 19
12/2  53/37/45/+9/…./0.0/000/00           25 SSE RMY 25
12/3  53/37/45/+9/…./0.0/162/29           43 WNW RMY 42
12/4  47/32/40/+5/0.00/0.0/444/80           32 NW  RMY 32
12/5  50/33/42/+7/0.00/0.0/548/99           21 W   RMY N/A
12/6  57/35/46/+11/0.00/0.0/531/96          22 SW  RMY N/A
12/7  54/37/46/+12/0.00/0.0/353/64          31 NE  RMY N/A
12/8  42/35/39/+5/0.01/0.0/000/00           32 NE  RMY 31
12/9  44/34/39/+5/…./0.0/044/08           28 SSE RMY N/A
12/10 57/41/49/+16/T/0.0/209/38             29 SE  RMY N/A
12/11 56/44/50/+17/0.00/0.0/049/09          28 SSW RMY 28
12/12 59/46/53/+20/0.00/0.0/367/67          23 W   RMY N/A
12/13 54/44/49/+17/0.00/0.0/000/00          18 ESE RMY 19
12/14 60/43/52/+20/…./0.0/000/00          32 S   RMY N/A
12/15 61/45/53/+21/…./0.0/371/68          48 W   RMY 51
12/16 45/34/40/+9/0.00/0.0/415/76           25 N   RMY N/A
12/17 53/36/45/+14/…./0.0/000/00          29 SE  RMY 28
12/18 50/35/43/+12/…./0.0/000/00          29 NW  RMY 30
12/19 38/30/34/+4/0.00/0.0/…/..           39 W   RMY 40
12/20 40/28/34/+4/0.00/0.0/…/..           24 W   RMY N/A
12/21 51/31/41/+11/T/0.0/…/..             38 SSW RMY 42
12/22 57/49/53/+24/0.28/0.0/000/00          35 SW  RMY 35
12/23 56/47/52/+23/…./0.0/…/..          30 E   RMY 27
12/24 67/48/58/+29/…./0.0/…/..          37 SSW RMY 39
12/25 64/52/58/+30/…./0.0/…/..          23 N   RMY N/A
12/26 53/40/47/+19/…./0.0/…/..          26 NNW RMY N/A
12/27 52/35/44/+16/…./0.0/000/00          36 NW  RMY 33

12/28 low since midnight is 30F; normal low is now 20F

DAILY RECORDS FOR DECEMBER 2015

**12/13/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 44F,
BREAKS PREVIOUS RECORD OF 43F SET IN 1919, TIED 1983
**12/24/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 61F SET IN 2014
**12/24/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 48F,
BREAKS PREVIOUS RECORD OF 46F SET IN 1900
**12/25/2015- NEW DAILY RECORD MAXIMUM TEMPERATURE OF 64F,
BREAKS PREVIOUS RECORD OF 62F SET IN 1889
**12/25/2015- NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 52F,
BREAKS PREVIOUS RECORD OF 46F SET IN 1964

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

RECORDS FOR DECEMBER 28
HIGH 60 IN 1982
LOW -2 IN 1933
PRECIP 2.16 INS. IN 1967
SNOWFALL 9.5 INS. IN 1967
PEAK GUST 89 MPH SSE IN 1983

RECORDS FOR DECEMBER 29
HIGH 72 IN 1984
LOW -19 IN 1933 (RECORD FOR DECEMBER)
PRECIP 1.91 INS. IN 1945
SNOWFALL 18.4 INS. IN 1945
PEAK GUST 95 MPH S IN 1966 (RECORD FOR DECEMBER)

TODAY’S REPORT PREPARED BY: Brian Fitzgerald