Saturday, September 30, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, SEPTEMBER 30, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

HEAVY RAIN AND HAIL DURING MORNING THUNDERSTORM

A passing low pressure system brought widespread heavy rain and
thunder to the region today.  Heavy rains began before 9:00AM EST
with hail lasting from about 9:00AM to 9:05AM.  Thunder began at
approximately 9:25AM and lasted through the hour.  Temperatures
reached the 6-hour maximum of 56F before falling to 48F during the
storm, and winds reached a peak gust of 28 MPH out of the northeast.
Precip. measured 2.03 in. at 1:00PM this afternoon with about 1.70
inches falling in the hour between 9:00AM and 10:00AM.  This brings
the monthly total to 5.21 inches which is nearly an inch above normal.

 

Today’s Observations:

7 A.M.
Weather: Broken cumulus, broken stratocumulus, broken altostratus,
fog W-N, patches of fog drifting below the summit
Temperature: 52F; Dew Point: 50F; Wind: estimated S at 3 kts,
Wind: Light
Sea-level pressure: 30.12 ins. Hg, rising, then more quickly
Visibility: 30 miles, except 10 miles NNE-NE and 5 miles W-N
6-hr Max temp: 52F
6-hr Min temp: 51F
24-hr precip: 0.01 in.
BHO SA 1155 E18 BKN 54 BKN 90 BKN 30 199/52/50/E1703/012/ VSBY NNE-NE 10
W-N 5 FG W-N PTCHS FG DRFTNG BLO SMT LTG DSNT N-NE WND LGT/ 8/510 53014
MANUAL 70001 ASOS 70001 10052 20051

10 A.M.
Weather: Thunder, rain, fog, overcast nimbostratus, hail began at
9:00AM and ended at 9:05AM EST
Temperature: 49F; Dew Point: 49F; Wind: ENE at 16G23 kts
Sea-level pressure: 30.18 ins. Hg, rising, then more quickly
Visibility: 4 miles
3-hr precip: 1.78 in.
BHO SA 1455 E34 OVC 4RF 219/49/49/0616G23/018/ IPB00E05 TSB25E59/
8/02/ 53020 MANUAL 6178/ ASOS 60183

1 P.M.
Weather: Scattered cumulus fractus, broken stratocumulus, overcast altostratus
Temperature: 54F; Dew Point: 52F; Wind: NE at 5 kts,
Wind: Light
Sea-level pressure: 30.22 ins. Hg, rising, then less quickly
Visibility: 30 miles, distant fog in all directions
6-hr Max temp: 56F
6-hr Min temp: 48F
6-hr precip: 2.03 in.
BHO SA 1755 11 SCT E49 BKN 64 OVC 30 234/54/52/0405/022/ DSNT FG ALQDS
WND LGT/ 8/72/ 51015 MANUAL 6203/ ASOS 60215 10056 20048

 

SUMMARY FOR FRIDAY, SEPTEMBER 29, 2017

TEMPERATURE (DEGREES F)
MAX…..65   NORMAL…..67
MIN…..46   NORMAL…..49
MEAN….56   NORMAL…..58

DEPARTURE FROM 30-YEAR NORMAL…………………….-2
TOTAL DEPARTURE FOR THE MONTH……………………+96 [+3.1 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….100   DEPARTURE………+41
TOTAL COOLING UNITS FOR THE SEASON…………707   DEPARTURE……..+111
TOTAL COOLING UNITS LAST SEASON TO DATE…….894   DEPARTURE……..-187

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………9   DEPARTURE……….+1
TOTAL HEATING UNITS FOR THE MONTH…………..52   DEPARTURE………-57
TOTAL HEATING UNITS FOR THE SEASON………….78   DEPARTURE………-56
TOTAL HEATING UNITS LAST SEASON TO DATE……..66   DEPARTURE………+12

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….21 NNW AT  1:18 A.M.
AERO……………………20 NNW AT  1:04 A.M.
ASOS……………………20 NW  AT  1:19 A.M.
DAVIS…………………..19 NNW AT 12:53 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………13 NNW AT  1:18 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………14 NNW AT  1:20 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13 NW  AT  1:20 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..7.2 NW
ASOS…………………..7.1
DAVIS………………….6.1 NW [316 DEG.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.01  DEPARTURE……-0.14
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….3.18  DEPARTURE……-0.73
ASOS…………..3.25
TOTAL PRECIPITATION FOR THE YEAR……….39.54  DEPARTURE……+0.61
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

 

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

9/1  68/47/58/-10/0.00/749/95              26 WNW AERO 28 WNW RMY 31
9/2  72/46/59/-9/0.00/542/69               18 NNW AERO 18 NNW RMY 21
9/3  63/52/58/-9/0.24/000/00               33 W   AERO 33 W   RMY 37
9/4  79/55/67/0/0.00/702/90                29 SSW AERO 28 SSW RMY N/A
9/5  84/62/73/+6/0.00/583/75               36 S   AERO 32 S   RMY 38
9/6  76/59/68/+1/0.49/070/09               28 S   AERO 28 S   RMY 30 TSTM
9/7  74/58/66/0/0.79/417/54                24*WSW AERO 23 WSW RMY 24
9/8  74/53/64/-2/0.00/577/75               21 WSW AERO 18 WSW RMY 22
9/9  68/51/60/-6/T/620/81                  18 ENE AERO 16 ENE RMY 18
9/10 71/51/61/-4/0.00/694/91               18 NW  AERO 16 NW  RMY N/A
9/11 78/50/64/-1/0.00/692/91               20 NNW AERO 17 NNW RMY 20
9/12 84/58/71/+6/0.00/690/91               22 WSW AERO 18 WSW RMY 23
9/13 84/59/72/+8/T/680/90                  18 WSW AERO 15 WSW RMY 20 TSTM
9/14 82/66/74/+10/0.00/233/31              23 SW  AERO 23 WSW RMY 25 TSTM
9/15 83/66/75/+11/0.05/300/40              18 WNW AERO 15 WNW RMY 18
9/16 78/65/72/+9/T/261/35                  14 E   AERO  9 E   RMY 12
9/17 79/61/70/+7/T/334/45                  15 SSE AERO 14 SSE RMY 15
9/18 67/62/65/+3/0.02/000/00               21 NE  AERO 18 NE  RMY N/A
9/19 63/61/62/0/0.13/000/00                28 NE* AERO 25 NNE RMY N/A
9/20 68/62/65/+3/0.67/000/00               41 NNE AERO 44 NNE RMY 45
9/21 69/60/65/+4/0.01/242/33               47 NNE AERO 44 NNE RMY 50
9/22 60/54/57/-4/0.56/…/..               40 NNE AERO 38 NNE RMY N/A
9/23 74/59/67/+7/0.21/…/..               29 NNE AERO 29 NNE RMY N/A
9/24 85/63/74/+14/0.00/…/..              16 N   AERO 14 N*  RMY N/A
9/25 86/66/76/+16/0.00/…/..              15 ESE*AERO 13 ESE RMY 14
9/26 84/66/75/+16/0.00/…/..              15 SW  AERO 12 SW* RMY 14
9/27 86/64/75/+16/0.00/…/..              21 S   AERO 20 S   RMY 22
9/28 75/52/64/+6/0.00/…/..               29 NNW AERO 30 NNW RMY 33
9/29 65/46/56/-2/0.00/…/..               21 NNW AERO 20 NNW RMY N/A

9/30 Low temp since midnight is 51F; normal low is now 49F

DAILY RECORDS FOR SEPTEMBER

9/1/17: DAILY RECORD LOW MINIMUM TEMPERATURE OF 47F,
TIES PREVIOUS RECORD SET IN 1975

9/27/17: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 86F,
BREAKS PREVIOUS RECORD SET IN 1998 AND TIED IN 2014

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

RECORDS FOR SEPTEMBER 30
HIGH 84F IN 1986
LOW 31F IN 1992
PRECIP 2.44 INCHES IN 2015
PEAK GUST 58 MPH SSE IN 1999

RECORDS FOR OCTOBER 1
HIGH 85F IN 1927
LOW 30F IN 1992
PRECIP 1.63 INCHES IN 2014
PEAK GUST 68e MPH SSE IN 1977

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle