Saturday, September 7, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, SEPTEMBER 7, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

Sunny and Dry

The morning low was around 51 degrees. Slightly warmer then yesterday’s low,
but continues to be seasonably cool. Bright sunshine from our clear skies
allowed the temperature to warm rapidly. As of the 1 o’clock our temperature
has risen to 76 degrees. The dry air with dew points in the lower 50s is
making for a beautiful day at the summit along with great visibility averaging
around 70-75 miles in all directions.

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant WSW-N, few lower cirrus distant NNW.
Temperature: 54F; Dew Point: 45F; Wind: WSW at 8 kts.
Sea-level pressure: 30.06 ins. Hg, falling, then rising
Visibility: 80 miles
6-hr min. temp: 51F
BHO SA 1155 CLR 80 180/54/45/2408/006/ FEW CI DSNT WSW-N FEW LWR CI
DSNT NNW/ 8/001 55000 10054 20051

10 A.M.
Weather: Clear, Few distant altocumulus NE, Few lower dense cirrus distant NW.
Temperature: 68F Dew Point: 49F; Wind WSW at 10 kts
Sea-level pressure: 30.03 ins. Hg, falling slightly
Visibility: 75 miles
BHO SA 1455 250 –SCT 75 170/68/49/2410/003/ FEW AC DSNT NE FEW LWR
DNS CI DSNT NW/ 8/031 56010

1 P.M.
Weather: Clear, few altocumulus distant ENE-E, few lower cirrus distant
NW-NNW
Temperature: 76F Dew Point: 49F; Wind WSW at 8 kts
Sea-level pressure: 29.97 ins. Hg, steadily falling
Visibility: 75 miles
BHO SA 1755 250 –SCT 75 150/76/49/2508/997/ FEW AC DSNT ENE-E FEW
LWR CI DSNT NW-NNW/ 8/001 56020 10076 20054

WEATHER SUMMARY FOR FRIDAY, SEPTEMBER 6, 2013

TEMPERATURE (DEGREES F)
MAX…..68     NORMAL…..75
MIN…..46     NORMAL…..58
MEAN….57     NORMAL…..67

DEPARTURE FROM 30-YEAR NORMAL…………………..-10
TOTAL DEPARTURE FOR THE MONTH……………………-5 [-1.0 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………+2
TOTAL COOLING UNITS FOR THE SEASON………..663   DEPARTURE…….+105
TOTAL COOLING UNITS LAST SEASON TO DATE……736   DIFFERENCE…….-73

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….18 WSW AT 11:08 P.M
AERO…………………17 WSW AT 11:08 P.M *
ASOS…………………20 WSW AT 11:09 P.M
DAVIS………………..16 WSW AT 08:14 P.M RMY N/A
FASTEST MILE FOR YESTERDAY………………14 WSW AT 11:22 P.M
MAXIMUM 2-MINUTE ASOS AVERAGE……………14 WSW AT 02:40 P.M
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..12 SW  AT 10:16 P.M
AVERAGE WIND SPEED AND DIRECTION………….8.5 WSW
ASOS………………….8.8
DAVIS…………………7.4 WNW [293 DEG.] * Last of several occurrences

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………….+2.12
ASOS…………..2.95
TOTAL PRECIPITATION FOR THE YEAR……….40.84   DEPARTURE………….+5.11
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  morning low temp: 51F; the normal low is now 58F

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

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

TODAY’S REPORT PREPARED BY: Mike Iacono / Kevin Pecora