Thursday, September 26, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, SEPTEMBER 26, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

COOL AND DRY PATTERN CONTINUES WITH
ANOTHER BEAUTIFUL FALL DAY

High pressure has been dominating the weather for the past couple of days,
making it cool and dry here at the summit. Yesterday was the fourth
consecutive day of below normal temps. Today begins a slight warming trend,
with a low of 52 degrees, 1 degree above the average for the date.

This morning was cloudy with a clearing line visible to the NE. This line of
clearing moved in the area, causing us to have bright sunshine around the
noon hour. This has caused our temperatures to rise into the upper 50s to
low 60s. It has made for a beautiful fall day. The pattern has made for
some very nice weather, but it has been dry. Even though September is
running above average for rain, some is needed. Most of the rain was
received on the 1st of month, and was the only day we had above an inch.
If the pattern continues, the month could finish only normal to slightly
below for rain.

Today’s Observations:

7 A.M.
Weather: Overcast, stratocumulus, few cumulus and moderate cumulus NE-SE
break in overcast, line of clearing NW-ESE
Temperature: 53F; Dew Point: 47F; Wind: NNW at 4 kts.
Sea-level pressure: 30.03 in. Hg, rising then rising more rapidly
Visibility: 60 miles, NW 70 miles, light distant haze
6-hr min. temp: 52F
BHO SA 1155 E36 OVC 60 170/53/47/3404/003/ FEW CU/MDT CU NE-SE BINOVC/LINE
OF CLRG NW-ESE VSBY NW 70 LGT DSNT HZ 8/8// 53010 10053 20052

10 A.M.
Weather: Scattered cumulus, few moderate cumulus, overcast stratocumulus
few moderate cumulus tops
Temperature: 57F; Dew Point: 47F; Wind: NE at 5 kts.
Sea-level pressure: 30.06 in. Hg rising sligtly
Visibility: 60 miles, NW 70 miles, light distant haze
BHO SA 1455 25 SCT E34 OVC 60 178/57/47/0505/006/ BINOVC ALQDS
FEW MDT CU VSBY NW 70 DSNT LGT HZ/ 8/8// 51008

1 P.M.
Weather: Scattered cumulus/stratocumulus, stratocumulus generated
by cumulus, few moderate cumuliform tops, clouds decreasing
Temperature: 62F; Dew Point: 47F; Wind: ENE at 6 kts.
Sea-level pressure: 30.05 in. Hg, falling slightly
Visibility: 70 miles, NW 75 miles, light distant hazenw
6-hr max. temp: 62F
BHO SA 1755 32 SCT 70 175/62/47/0706/005/CLDS DCRSNG CU/SCCG/ FEW MDT
TOPS CLDS DCRSNG VSBY NW 75 LGT DSNT HZ/ 8/800 58003 10062 20053

WEATHER SUMMARY FOR WEDNESDAY, SEPTEMBER 25, 2013

TEMPERATURE (DEGREES F)
MAX…..64 NORMAL…..68
MIN…..45 NORMAL…..51
MEAN….55 NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL…………………-5
TOTAL DEPARTURE FOR THE MONTH………………..-25 [-1.2 DEGREE/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0 DEPARTURE………-1
TOTAL COOLING UNITS FOR THE MONTH………….56 DEPARTURE……….0
TOTAL COOLING UNITS FOR THE SEASON………..696 DEPARTURE…….+103
TOTAL COOLING UNITS LAST SEASON TO DATE……765 DIFFERENCE…….-69

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….10 DEPARTURE………+4
TOTAL HEATING UNITS FOR THE MONTH…………103 DEPARTURE……..+23
TOTAL HEATING UNITS FOR THE SEASON………..115 DEPARTURE……..+10
TOTAL HEATING UNITS LAST SEASON TO DATE…….63 DIFFERENCE…….+52

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………18 N AT 8:37 A.M.
AERO…………………..18 N AT 8:36 A.M.*
ASOS…………………..20 N AT 8:27 A.M.
DAVIS………………….18 N AT 8:27 A.M. RMY 19
FASTEST MILE FOR YESTERDAY………………..14 NW AT 6:33 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..14 NW AT 6:33 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….13 NW AT 6:33 A.M.
AVERAGE WIND SPEED AND DIRECTION………….7.3 WNW
ASOS………………….7.1
DAVIS…………………6.5 N [350 degrees] * last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00 DEPARTURE………….-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….3.91 DEPARTURE………….+0.58
ASOS…………..4.04
TOTAL PRECIPITATION FOR THE YEAR……….41.92 DEPARTURE………….+3.57
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/+4/2.32/008/01 33 S AERO 39 MPH S RMY 38 TSTM
9/2 79/67/73/+5/0.43/056/07 30 SSE AERO 33 MPH SSE RMY N/A TSTM
9/3 79/61/70/+3/0.00/219/28 28 S AERO 29 MPH S RMY 30 TSTM
9/4 78/57/68/+1/0.00/733/94 24 W AERO 25 MPH W RMY 25
9/5 66/51/59/-8/0.08/179/23 20 NNE AERO 20 MPH NNE RMY 21
9/6 68/46/57/-10/0.00/751/97 18 WSW AERO 17 MPH WSW RMY N/A
9/7 78/51/65/-1/0.00/594/77 20 WSW AERO 21 MPH WSW RMY 21
9/8 74/50/62/-4/0.00/646/84 31 NW AERO 33 MPH NW RMY 32
9/9 69/47/58/-8/T/529/69 23 SW AERO 23 MPH SSW RMY N/A
9/10 73/56/65/0/0.03/007/01 30 S AERO 32 MPH S RMY 33
9/11 93/68/81/+16/0.00/654/86 25 SW AERO 27 MPH SW RMY N/A
9/12 85/66/76/+11/0.47/455/60 32 S AERO 33 MPH S RMY 34 TSTM
9/13 79/58/69/+5/0.17/242/32 24 NNW AERO 25 MPH NNW RMY 23
9/14 67/52/60/-4/0.00/361/48 21 NW AERO 21 MPH NW RMY 21
9/15 70/48/59/-5/0.00/547/73 17 WSW AERO 18 MPH WSW RMY 20
9/16 66/46/56/-7/0.02/179/24 29 NNW AERO 31 MPH NNW RMY 30
9/17 60/40/50/-13/0.00/722/97 27 NNE AERO 27 MPH NNE RMY 26
9/18 73/47/60/-2/0.00/726/98 18 W AERO 18 MPH WSW RMY 20
9/19 78/51/65/+3/0.00/731/99 17 WSW AERO 16 MPH WSW RMY 18
9/20 78/54/66/+4/0.00/706/96 18 SSW AERO 18 MPH SSW RMY 23
9/21 74/57/66/+4/T/512/70 35 S AERO 40 MPH S RMY N/A
9/22 70/49/60/-1/0.39/365/50 38 S AERO 39 MPH S RMY 42
9/23 63/43/53/-7/0.00/711/98 25 NW AERO 26 MPH NW RMY 28
9/24 65/40/53/-7/0.00/702/97 22 ENE AERO 22 MPH ENE RMY 23
9/25 64/45/55/-5/0.00/…/.. 18 N AERO 18 MPH N RMY 19

9/26 the morning low temp: 52F; the normal low is now 51F

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
9/11 – TIED DAILY RECORD MAXIMUM HIGH TEMPERATURE OF 93F;
ties record of 93F set in 1983

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

RECORDS FOR SEPTEMBER 26
HIGH 91F IN 2007
LOW 36F IN 1905,1922,1978
PRECIP 3.84 INCHES IN 1888
PEAK GUST 54e MPH S IN 1977

RECORDS FOR SEPTEMBER 27
HIGH 84F IN 1998
LOW 32F IN 1947
PRECIP 2.26 INCHES IN 1962
PEAK GUST 100 MPH SSE IN 1985 (HURRICANE GLORIA)

TODAY’S REPORT PREPARED BY: Kevin Pecora and Robert Skilling