Tuesday, November 12, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, NOVEMBER 12, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

FIRST MEASURABLE SNOW OF THE SEASON;
TEMPERATURE DROPPED QUICKLY THIS MORNING

Light rain began falling early this morning, amounting to only approximately
0.07 inch. A few slushy rain drops began mixing in shortly before 7 a.m.

The rain/slush mix abruptly transitioned to all snow at approximately
7:21 a.m. The transition from rain to snow was quite apparent. A wall of
white could be seen slowly progressing southward across the area, eventually
enveloping the summit beginning at 7:21 a.m. Check out the member area of
bluehill.org for a photo.

The snow began tapering to intermittent flurries around 8:40 a.m.

Snowfall reached 0.2 inch on the summit, making this the first measurable
snowfall of the season. The liquid to snow ratio was 1:4 or 5. Light
accumulation was visible on nearby Chickatawbut Hill (3 miles E). Little
if any accumulation was visible below an elevation of about 450-500 feet.

Light snow was observed on Sunday, November 3 and Friday, November 8, but
no accumulation occurred on those dates.

The long term (1886-2012) average date of the first snowfall is November 18,
and the 30-year (1981-2010) average date of the first snowfall is
November 20. Last year, the first measurable snowfall occurred on
November 7 with 3.5 inches.

As the cold air rushed in early this morning, temperatures dropped quite
quickly. A high of 48F was reached on the summit at about 1:30 a.m., with
the temperature dropping to 32F by 8 a.m. The temperature has been fairly
steady since then, near 31-32F. Consequently, some of the snow that fell
this morning remains on the ground.

Also in association with the early morning front, a peak wind gust of
41 mph from the SW was recorded. Winds this afternoon are much lower,
in the 10-15 mph range.

Today’s Observations:

7 A.M.
Weather: Light rain, scattered stratus, broken stratus fractus, overcast
nimbostratus, dark low stratus layer extending distant WSW-N-ENE, thin fog
all quadrants, light rain continued
Temperature: 36F; Dew Point: 36F; Wind: WNW at 10 kts.
Sea-level pressure: 30.97 ins. Hg, rising then rising more rapidly
Visibility: 10 miles, light rain and thin fog all quadrants
6-hr min temp: 48F
6-hr min temp: 36F
24-hr precip: 0.05 inch
BHO SA 1155 5 SCT E10 BKN 30 OVC 10R- 150/36/36/2910/997/ DRK LW STRA LYR
XTNDNG DSNT WSW-N-ENE THN FG ALQDS VSBY E-SW 12 R- CTD/ 8/72/ 53016
MANUAL 70005 ASOS 70004 MANUAL 60005 ASOS 60004 10048 20036

10 A.M.
Weather: Broken stratus fractus, broken stratocumulus, broken altocumulus,
few lower cumulus/cumulus fractus distant WSW-N, higher altocumulus visible
distant NNW-N, light distant haze, total new snow past 3 hours 0.2 inch
Temperature: 32F; Dew Point: 30F; Wind: NW at 9 kts,
Wind: Direction variable W-NNW
Sea-level pressure: 30.05 ins. Hg, rising then rising more slowly
Visibility: 50 miles, E-S 30 miles, SSW 45 miles, NW 75 miles, light
distant haze
3-hr precip: 0.06 inch
3-hr snowfall: 0.2 inch
BHO SA 1455 E50 BKN 60 BKN 100 BKN 50 175/32/30/3109/005/ FEW LWR CU/CUFRA
DSNT WSW-N HIER AC VSBL DSNT NNW-N LGT DSNT HZ VSBY E-S 30 SSW 45 NW 75
WND 27V34 TOTAL NEW SNW PST 3 HRS 0.2 IN/ 8/870 51025 MANUAL 60006
ASOS 60007

1 P.M.
Weather: Scattered cumulus, scattered altostratus, broken altostratus,
broken altocumulus, cumulus mostly SSE-W-N, few cumulus NE-ESE, line of
clearing extending distant WSW-NNE, light distant haze
Temperature: 31F; Dew Point: 23F; Wind: NNW at 9 kts,
Wind: Direction variable WNW-N
Sea-level pressure: 30.04 ins. Hg, falling then steady
Visibility: 70 miles, E-S lower, NW 75 miles, light distant haze
6-hr precip: 0.06 inch
6-hr snowfall: 0.2 inch
6-hr max temp: 36F
BHO SA 1755 30 SCT 80 SCT E100 BKN 140 BKN 70 172/31/23/3309/004/ CU MSTLY
SSE-W-N FEW CU NE-ESE LINE CLRNG XTNDNG DSNT WSW-NNE LGT DSNT HZ VSBY E-S
LWR NW 75 WND 29V36/ 8/170 55003 MANUAL 60006 ASOS 60007 10036 20031

WEATHER SUMMARY FOR MONDAY, NOVEMBER 11, 2013

TEMPERATURE (DEGREES F)
MAX…..51 NORMAL…..52
MIN…..36 NORMAL…..35
MEAN….44 NORMAL…..43

DEPARTURE FROM 30-YEAR NORMAL………………….+1
TOTAL DEPARTURE FOR THE MONTH………………….+9 [+0.6 DEGREE/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..21 DEPARTURE………-1
TOTAL HEATING UNITS FOR THE MONTH………….218 DEPARTURE………-4
TOTAL HEATING UNITS FOR THE SEASON…………695 DEPARTURE……..-90
TOTAL HEATING UNITS LAST SEASON TO DATE…….662 DIFFERENCE…….+33

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………36 WNW AT 12:15 A.M.
AERO…………………..37 WNW AT 12:15 A.M.
ASOS…………………..39 W AT 12:15 A.M.
DAVIS………………….36 WNW AT 12:39 A.M. RMY: 37
FASTEST MILE FOR YESTERDAY………………..28 WNW AT 12:40 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..28 W AT 12:41 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….25 W AT 12:15 A.M.
AVERAGE WIND SPEED AND DIRECTION…………15.1 W
ASOS…………………14.5
DAVIS………………..13.3 WSW [254 degrees] * last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.05 DEPARTURE…………-0.11
ASOS…………..0.04
TOTAL PRECIPITATION FOR THE MONTH……….0.60 DEPARTURE…………-1.12
ASOS…………..0.57
TOTAL PRECIPITATION FOR THE YEAR……….43.61 DEPARTURE…………-1.88
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…….Trace DEPARTURE………….-0.1
TOTAL SNOWFALL FOR THE MONTH………….Trace DEPARTURE………….-0.4
TOTAL SNOWFALL FOR THE SEASON…………Trace DEPARTURE………….-0.7

PRELIMINARY CLIMATE SUMMARY FOR NOVEMBER 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

11/1 68/56/62/+16/0.10/0.0/012/02 60 SSW AERO N/A N/A RMY 66
11/2 65/49/57/+11/0.00/0.0/296/48 22 WSW AERO N/A N/A RMY 23
11/3 49/30/40/-6/0.06/T/135/22 23 N AERO N/A N/A RMY N/A
11/4 42/27/35/-10/0.00/0.0/588/96 24 NNE AERO N/A N/A RMY 25
11/5 50/29/40/-5/0.00/0.0/487/80 16 SSW AERO N/A N/A RMY 17
11/6 59/40/50/+5/0.00/0.0/419/69 30 SSW AERO 31 MPH SSW RMY 33
11/7 65/37/51/+6/0.31/0.0/079/13 33 SW AERO 37 MPH SW RMY 37
11/8 48/31/40/-4/T/T/0.0/421/70 37 WNW AERO 37 MPH WNW RMY 39
11/9 44/29/37/-7/0.00/0.0/361/66 25 WNW AERO 25 MPH WNW RMY 29
11/10 52/40/46/+2/0.08/0.0/108/18 31 WNW AERO 33 MPH WNW RMY N/A
11/11 51/36/44/+1/0.00/0.0/…/.. 36 WNW AERO 37 MPH WNW RMY 37

11/12 morning low temp: 36F; the normal low is now 35F

DAILY RECORDS FOR NOVEMBER 2013
None so far.

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

RECORDS FOR NOVEMBER 12
HIGH 74 IN 1909
LOW 18 IN 1926
PRECIP 3.25 INCHES IN 1947
SNOWFALL 8.1 INCHES IN 1987
PEAK GUST 79e MPH NW IN 1947

RECORDS FOR NOVEMBER 13
HIGH 66 IN 1931, 1964
LOW 14 IN 1920
PRECIP 1.96 INCHES IN 1982
SNOWFALL 4.6 IN 2004
PEAK GUST 77 S IN 1982

TODAY’S REPORT PREPARED BY: Sean Fankhauser