Monday, September 16, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, SEPTEMBER 16, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

SEASONABLY WARM AND DRY WITH EXCELLENT VISIBILITY TODAY…

Moderate early morning cloudiness quickly gave way to mostly
sunny skies. Minimal visibility throughout observations was
80 miles increasing to 85 miles at the 1 PM observation. Dew points
decreased from 50 degrees at 7 AM to 44 degrees by early afternoon
indicating a decrease in humidity. Our high so far today is 71F, 1
degree below the normal high of 72F. Our low since midnight is 57F,
2 degrees above the normal of 55F.

PRELIMINARY STATS FOR AUGUST 2019

TEMPERATURE, Deg. F
Avg. Max. 80.4 [+1.2] Avg. Min. 62.1 [+0.3] Mean      71.3 [+0.8] 24-hour corrected mean: 70.5
Max. for month: 92F on the 19th
Min. for month: 51F on the 26th

COOLING DEGREE DAYS
Total cooling units:   211 [+22] Total for the season:  619 [+82] Total for last season: 753

PRECIPITATION, Inches
Total: 1.83 [-2.21] Greatest in 24 hrs: 0.81 ins. on the 28th-29th

WIND, mph
Avg. uncorrected wind speed: 9.1 mph
Avg. corrected wind speed:   9.8 mph
Prevailing wind direction: N/A
Peak gust and direction: N/A

SUNSHINE:
Campbell-Stokes card minutes: 16404 minutes of possible 24780 or 66%
Astronomical total minutes: 17074 minutes of possible 25768 or 66%

Today’s Observations:

7 A.M.
Weather: Scattered Stratocumulus, Scattered Cirrocumulus, Broken Cirrus
Few Altocumulus (distant, S-SW)
Temperature: 59F; Dew Point: 50F; Wind: N at 7 kts gusting to 14 kts
Sea-level pressure: 30.08 ins. Hg, rising, then steady
Visibility: 80 miles
6-hr Max temp: 63F
6-hr Min temp: 57F
24-hr Precip: Trace
BHO SA 1155 50 SCT 200 SCT E250 BKN 80 185/59/50/3507G14/008/
FEW AC DSNT S-SW/ 8/589 51012 70000 10063 20057

10 A.M.
Weather: Scattered Cirrus
Few Cumulus (distant, all quadrants), Few Altocumulus (S-SW),
Few Cirrostratus (distant, N-E)
Temperature: 66F; Dew Point: 48F; Wind: NW at 9 kts, gusting to 20 kts
Sea-level pressure: 30.06 ins. Hg, falling, then more rapidly
Visibility: 85 miles
3-hr Precip: 0.00 ins.
BHO SA 1455 250 SCT 85 179/66/48/3109G20/006/ FEW SML CU DSNT ALQDS
FEW AC S-SW FEW CS DSNT N-E WND 26V02/ 8/288/ 58006

1 P.M.
Weather: Scattered Cumulus, Few Altocumulus (distant, SE-SW-W)
Temperature: 70F; Dew Point: 44F; Wind: WNW at 8 kts
Sea-level pressure: 30.02 ins. Hg, falling, then more quickly
Visibility: 85 miles
6-hr Max temp: 71F
6-hr Min temp: 59F
6-hr Precip: 0.00 ins.
BHO SA 1755 50 SCT 85 166/70/44/3008/002/ FEW AC DSNT SE-SW-W
WND 23V36/ 8/280/ 58013 10071 20059

SUMMARY FOR SUNDAY, SEPTEMBER 15, 2019

TEMPERATURE (DEGREES F)
MAX…..78   NORMAL…..72
MIN…..62   NORMAL…..55
MEAN….70   NORMAL…..64

DEPARTURE FROM 30-YEAR NORMAL………………….+6
TOTAL DEPARTURE FOR THE MONTH…………………-23 [-1.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON AUG TO JUL)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE………-3
TOTAL HEATING UNITS FOR THE MONTH…………..34   DEPARTURE………+3
TOTAL HEATING UNITS FOR THE SEASON………….46   DEPARTURE……..-10
TOTAL HEATING UNITS LAST SEASON TO DATE……..28   DEPARTURE……..+18

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………5   DEPARTURE………+3
TOTAL COOLING UNITS FOR THE MONTH…………..25   DEPARTURE……..-18
TOTAL COOLING UNITS FOR THE SEASON…………644   DEPARTURE……..+64
TOTAL COOLING UNITS LAST SEASON TO DATE…….829   DEPARTURE…….-185

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..24 W   AT  1:50 P.M.
AERO…………………….23 W   AT  1:50 P.M.
ASOS…………………….23 W   AT  3:34 P.M.
DAVIS……………………24 SW  AT  1:48 P.M. RMY 22
FASTEST MILE FOR YESTERDAY………………….15 W   AT  3:53 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….16 W   AT  3:42 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………16 W   AT  3:41 P.M.
AVERAGE WIND SPEED AND DIRECTION……………10.0 W
ASOS……………………10.0
DAVIS…………………..10.7 W [267 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….TRACE DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.98  DEPARTURE……-0.90
ASOS…………..0.96
TOTAL PRECIPITATION FOR THE YEAR……….38.13  DEPARTURE……+1.09
ASOS………….37.99

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

9/01  73/56/65/-3/0.00/…/..                21 ENE AERO 14 ENE RMY 18
9/02  75/57/66/-2/0.37/…/..                39 W   AERO 41 W   RMY 41
9/03  77/61/69/+2/0.00/…/..                18 S   AERO 16 S   RMY N/A
9/04  83/61/72/+5/0.00/…/..                30 SW  AERO 28 SW  RMY 30
9/05  68/54/61/-6/0.00/…/..                23 NW  AERO 17 NW  RMY N/A
9/06  65/56/61/-6/…./…/..                37 ENE AERO 36 ENE RMY 36
9/07  70/51/61/-5/0.00/…/..                37 N   AERO 37 N   RMY N/A
9/08  73/53/63/-3/0.00/…/..                25 W   AERO 21 W   RMY N/A
9/09  71/54/63/-3/0.00/…/..                17 SE  AERO 16 SE  RMY 16
9/10  73/57/65/0/0.00/…/..                 25 S   AERO 25 S   RMY N/A
9/11  83/63/73/+8/0.00/…/..                31 SW  AERO 32 SW  RMY N/A
9/12  70/52/61/-4/0.11/…/..                29 ENE AERO 28 ENE RMY 28
9/13  65/49/57/-7/0.00/…/..                29 ENE AERO 27 ENE RMY 27
9/14  69/49/59/-5/…./…/..                36 S   AERO 37 S   RMY 37
9/15  78/62/70/+6/0.00/…/..                24 W   AERO 23 W   RMY 22

9/16  High so far 71F, Low so far 57F

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

RECORDS FOR SEPTEMBER 16
HIGH 91F IN 1939,1941
LOW 39F IN 1984
PRECIP 5.12 INCHES IN 1933 (Hurricane)
PEAK GUST 59 MPH SSE IN 1999

RECORDS FOR SEPTEMBER 17
HIGH 87F IN 2015
LOW 38F IN 1959
PRECIP 2.73 INCHES IN 1933
PEAK GUST 60 MPH WNW IN 1999

TODAY’S REPORT PREPARED BY: Matt Douglas and Andrew Swanson