Sunday, September 8, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, SEPTEMBER 8, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUD COVER THINS THROUGHOUT THE DAY
BREEZY AFTERNOON KEEPS TEMPS IN THE LOW 70S

This morning started out overcast and relatively humid, with overnight lows only
reaching around 60F. After the overcast broke, there was nothing but fair weather
cumulus humilis and fractus clouds in the skies Winds shifted slowly throughout the
day from WSW toward the north while both sustained and peak speeds increased
throughout the afternoon. Barometric pressure has remained mostly constant,
with a very gradual rise starting around noon.

Today’s Observations:

7 A.M.
Weather: Overcast moderate cumulus with few breaks, few cumulus lenticularis and
humilis distant WNW-NE
Temperature: 64F; Dew Point: 57F; Wind:  at  kts.
Sea-level pressure: 29.80
Visibility: 70 miles, light distant haze
6-hr min. temp: 61F

10 A.M.
Weather: Scattered cumulus humilis/fractus, broken moderate cumulus layer
distant WSW-NNE, altocumulus layer distant E-SSE and offshore NE-E
Temperature: 71F; Dew Point: 59F; Wind NW at 13 kts
Sea-level pressure: 29.75 ins. Hg, decreasing then increasing
Visibility: 70 miles, light distant haze
BHO SA 1455 50 SCT 70 076/71/59/3113/975/ BKN CU LYR DSNT WSW-NNE
AC/AS LYR DSNT E-SSE AND OFSHR NE-E LT DSNT HZ/ 8/270 55004

1 P.M.
Weather: Scattered cumulus (humilis WNW-E, moderatus E-WNW), few cirrus fibratus
in vicinity NW-E, low moderate cumulus layer distant offshore NE-E
Temperature: 72F; Dew Point: 56F; Wind NW at 16 kts
Sea-level pressure: 29.78 ins. Hg, increasing then increasing more rapidly
Visibility: 80 miles
6 Hour min. temp: 62F
BHO SA 1755 50 SCT 80 084/72/56/3116/978/ MDT CU LYR DSNT OFSHR NE-E
FEW CI FIB IN VCY NW-E/ 8/201 53008 10071 20062

WEATHER SUMMARY FOR SATURDAY, SEPTEMBER 7, 2013

TEMPERATURE (DEGREES F)
MAX…..78     NORMAL…..75
MIN…..51     NORMAL…..58
MEAN….65     NORMAL…..66

DEPARTURE FROM 30-YEAR NORMAL…………………..-1
TOTAL DEPARTURE FOR THE MONTH…………………..-6 [-0.9 DEGREE/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0   DEPARTURE………-2
TOTAL COOLING UNITS FOR THE MONTH………….23   DEPARTURE………-1
TOTAL COOLING UNITS FOR THE SEASON………..663   DEPARTURE…….+102
TOTAL COOLING UNITS LAST SEASON TO DATE……747   DIFFERENCE…….-84

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….20 WSW AT 12:30 P.M
AERO…………………21 WSW AT 12:28 P.M
ASOS…………………21   W AT  1:35 P.M
DAVIS………………..20 WSW AT  2:34 A.M RMY 21
FASTEST MILE FOR YESTERDAY………………17 WSW AT  4:00 A.M
MAXIMUM 2-MINUTE ASOS AVERAGE……………16  SW AT 12:20 P.M
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..16 WSW AT  4:02 A.M
AVERAGE WIND SPEED AND DIRECTION………….11.6 WSW
ASOS………………….10.9
DAVIS…………………10.3 SW [234 DEG.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00   DEPARTURE………….-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.83   DEPARTURE………….+1.99
ASOS…………..2.95
TOTAL PRECIPITATION FOR THE YEAR……….40.84   DEPARTURE………….+4.98
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  68/46/57/-10/0.00/…/..        18 WSW AERO 17 MPH WSW RMY N/A
9/7  78/51/65/0/0.00/…/..          20 WSW AERO 21 MPH WSW RMY 21

9/8  morning low temp: 59F; the normal low is now 57F

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 8
HIGH 93F IN 2007
LOW 42F IN 1978
PRECIP 1.51 INCHES IN 2011
PEAK GUST 45 MPH S IN 2012

RECORDS FOR SEPTEMBER 9
HIGH 91F IN 2002
LOW 41F IN 1938
PRECIP 1.97 INCHES IN 1969
PEAK GUST 52 MPH WNW IN 1969, NW IN 1978

TODAY’S REPORT PREPARED BY: Forrest Iwanik