Friday, September 6, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, SEPTEMBER 6, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

COOLEST OF THE SEASON–DOWN TO 46F AT THE SUMMIT
TEMPERATURES RISING RAPIDLY INTO THE 60’S THIS MORNING

This morning’s low temperature of 46 degrees was 12
degrees below the average for this date of 58 degrees but
well short of the record low for the date of 39F way
back in the early record in 1888.  All but that one
of the record lows for the first 10 days of September
are in the 40 to 46 degree range.

Plenty of bright early September sunshine was sending
the thermometer up 6 degrees in the hour from 8 to 9
A.M. EDT.

Today’s Observations:

7 A.M.
Weather: Clear, few small cumulus distant E-SE, cirrus except
overhead through SE
Temperature: 50F; Dew Point: 42F; Wind: N at 8 kts
Sea-level pressure: 30.24 ins. Hg, rising, then rising more slowly
Visibility: 75 miles, light distant haze
6-hr min. temp: 46F
BHO SA 1155 CLR 75 239/50/42/3508/024/ FEW SML CU DSNT E-SE CI
XCPT OVHD-SE/ 8/101 51012 MANUAL 70008 ASOS 70007 10050 20046

10 A.M.
Weather: Thin scattered cirrus, thin broken cirrus, small cumulus
mostly distant ESE-SSE
Temperature: 60F Dew Point: 38F; Wind WSW at 3 kts
Sea-level pressure: 30.25 ins. Hg, rising, then falling slightly
Visibility: 75 miles, light distant haze
BHO SA 1455 200 -SCT 250 -BKN 75 243/60/38/2503/025/ FEW SML CU
DSNT ESE-SSE LGT DSNT HZ/ 8/101 50004

WEATHER SUMMARY FOR THURSDAY, SEPTEMBER 5, 2013

TEMPERATURE (DEGREES F)
MAX…..66     NORMAL…..75
MIN…..51     NORMAL…..58
MEAN….59     NORMAL…..67

DEPARTURE FROM 30-YEAR NORMAL…………………..-8
TOTAL DEPARTURE FOR THE MONTH…………………..+5 [+0.8 DEGREE/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0   DEPARTURE………-3
TOTAL COOLING UNITS FOR THE MONTH………….23   DEPARTURE………+5
TOTAL COOLING UNITS FOR THE SEASON………..663   DEPARTURE…….+108
TOTAL COOLING UNITS LAST SEASON TO DATE……731   DIFFERENCE…….-68

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….20 NNE AT 10:56 A.M.
AERO…………………20 NNE AT 10:56 A.M.
ASOS…………………21 NNE AT 10:56 A.M.
DAVIS………………..20 NNE AT 10:56 A.M. RMY 21
FASTEST MILE FOR YESTERDAY………………14 NNE AT 10:56 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………14 ENE AT 11:57 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..14 NNE AT 10:57 A.M.
AVERAGE WIND SPEED AND DIRECTION………….8.3 WSW
ASOS………………….8.2
DAVIS…………………7.3 WNW [290 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.08   DEPARTURE………….-0.04
ASOS…………..0.07
TOTAL PRECIPITATION FOR THE MONTH……….2.83   DEPARTURE………….+2.25
ASOS…………..2.95
TOTAL PRECIPITATION FOR THE YEAR……….40.84   DEPARTURE………….+5.24
ASOS…………..N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

9/1  76/67/72/+4/2.32/…/..         33 S   AERO 39 MPH S   RMY 38   TSTM
9/2  79/67/73/+5/0.43/…/..         30 SSE AERO 33 MPH SSE RMY N/A  TSTM
9/3  79/61/70/+3/0.00/…/..         28 S   AERO 29 MPH S   RMY 30
9/4  78/57/68/+1/0.00/…/..         24 W   AERO 25 MPH W   RMY 25
9/5  66/51/59/-8/0.08/…/..         20 NNE AERO 20 MPH NNE RMY 21

9/6  morning low temp: 46F; the normal low is now 58F

DAILY RECORDS FOR AUGUST 2013
None.

DAILY RECORDS FOR SEPTEMBER 2013
9/1 – NEW DAILY RECORD MAXIMUM PRECIPITATION OF 2.32 INCHES;
surpasses previous record of 1.60 inches set in 1927

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

RECORDS FOR SEPTEMBER 6
HIGH 92F IN 1900
LOW 39F IN 1888
PRECIP 3.19 INCHES IN 1890
PEAK GUST 78e MPH SE IN 1979 (TROPICAL STORM DAVID)

RECORDS FOR SEPTEMBER 7
HIGH 92F IN 2007
LOW 40F IN 1888
PRECIP 2.95 INCHES IN 1891
PEAK GUST 58e MPH W IN 1941

TODAY’S REPORT PREPARED BY: ROBERT SKILLING