Monday, September 16, 2024

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

MONDAY, SEPTEMBER 16, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0526E
SUNSET:  1751E

SUNNY AND DRY WEATHER CONTINUES WITH ABOVE NORMAL TEMPERATURES…

Sunshine has been the theme today with more wildfire smoke aloft
creating milky skies. A few cirrus have been observed as well in
the distant southern quadrants of the sky.

Rainfall remains a mystery to the region as we go yet another day
without any. 0.04″ is the total for the month of September so far,
which is now 1.79″ below what we’d expect to date.

Temperatures are once again above normal for the day with readings
reaching the lower 80s. The normal high for today is 73F! The dew
point on the other hand has dropped off markedly with readings
going from the low 50s early this morning into the lower 30s early
this afternoon. The relative humidity has slipped below 20% for the
first time this early fall season.

The wind has been on the light and variable side today. The average
speed for the day so far is only around 5mph. The peak gust so far
is a measly 11mph, which occurred around 2am this morning, and
again just before 1pm this afternoon.

Visibility has been decent for the most part today. It started the
day around 60 miles early this morning, but dipped to 45-50 miles
for a time during the mid to late morning hours as haziness got
trapped under an inversion. Since the inversion has lifted early
this afternoon, and the air has dried out significantly, the view
has bounced back to 60-70 miles.

The maximum temperature so far today is 81F, which is 8 degrees
above the normal high of 73F. The minimum temperature since midnight
is 55F, which is 1 degree below the normal low of 56F.

————————————————————–

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant S-WSW, thin smoke layer aloft
all quadrants
Temperature: 62F; Dew Point: 50F; Relative Humidity: 64%
Wind: WNW @ 4 kts, wind light
Sea-level pressure: 1029.1 mb; 30.39 in. Hg: rising, then more slowly
Visibility: 60 miles
6-hr Max temp: 62F
6-hr Min temp: 55F
24-hr Precip:  0.00 inches
BHO SA 1155 CLR 60 291/62/50/3004/039/ FEW CI DSNT S-WSW THN K LYR ALF
ALQDS WND LGT/ 8/001 51007 10062 20055

10 A.M.
Weather: Clear, few cirrus distant S-SSW, thin smoke layer aloft
all quadrants
Temperature: 72F; Dew Point: 41F; Relative Humidity: 32%
Wind: WNW @ 2 kts, wind light and variable
Sea-level pressure: 1029.0 mb; 30.39 in. Hg: rising, then falling
Visibility: 50 miles, hazy
3-hr Precip: 0.00 inches
BHO SA 1455 CLR 50 290/72/41/2902/039/ FEW CI DSNT S-SSW THN K LYR ALF
ALQDS HAZY WND L/V/ 8/001 58001

1 P.M.
Weather: Clear, few cumulus distant NW, thin smoke layer aloft
all quadrants
Temperature: 80F; Dew Point: 31F; Relative Humidity: 16%
Wind: SSW @ 4 kts, wind light
Sea-level pressure: 1027.5 mb; 30.34 in. Hg: falling, then more rapidly
Visibility: 70 miles
6-hr Max temp: 81F
6-hr Min temp: 62F
6-hr Precip: 0.00 inches
BHO SA 1755 CLR 70 275/80/31/2004/034/ FEW CU DSNT NW THN K LYR ALF
ALQDS WND LGT/ 8/200 58015 10081 20062

————————————————————–

SUMMARY FOR SUNDAY, SEPTEMBER 15, 2024

TEMPERATURE (DEGREES F)
MAX…….78  NORMAL…..73
MIN…….60  NORMAL…..56
MEAN……69  NORMAL…..65

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..+4
TOTAL DEPARTURE FOR THE MONTH……………………..+8 [+0.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-3
TOTAL HEATING UNITS FOR THE MONTH……………10  DEPARTURE…….-15
TOTAL HEATING UNITS FOR THE SEASON…………..21  DEPARTURE…….-22
TOTAL HEATING UNITS LAST SEASON TO DATE……….8  DEPARTURE…….+13

COOLING DEGREE DAYS (SEASON: JAN 2024 THRU DEC 2024)
TOTAL COOLING UNITS FOR YESTERDAY…………….4  DEPARTURE……..+2
TOTAL COOLING UNITS FOR THE MONTH……………47  DEPARTURE……..-6
TOTAL COOLING UNITS FOR THE SEASON………….741  DEPARTURE…….+92
TOTAL COOLING UNITS LAST SEASON TO DATE……..689  DEPARTURE…….+52

PEAK WIND GUST (MPH):
Note: Instruments designated #1 = Main Tower, #2 = South Tower,
F420C, Contacting, Merlin, and Richards are all on Main Tower.
E=Estimated

F420C (Official)……….E23 SE   @   01:45 P.M.
VECTOR #1 (1-Sec)……….23 SE   @   01:45 P.M.
VECTOR #2 (1-Sec)……….20 SE   @   01:45 P.M.
DAVIS #1……………….23 SE   @   01:42 P.M.
DAVIS #2 ………………20 S    @   08:43 P.M.
RMY #1 (Instantaneous)…..25 SE   @   01:45 P.M.
RMY #2 (Instantaneous)…..20 SE   @   01:45 P.M.
MERLIN…………………21 SSE
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………12 S    @   08:39 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..12      @   08:02 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..13      @   08:56 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………12 ESE  @   01:47 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………17 S    @   08:56 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..12 SSE  @   08:19 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..13 SSE  @   08:56 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL……..6.0 ENE [145 total miles] VECTOR #1………………6.7
VECTOR #2………………7.0
DAVIS #1……………….6.5 ESE
DAVIS #2……………….6.7 SE
RMY #1…………………6.5 E
RMY #2…………………7.0 E
RICHARDS (C5C)………….OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.13
TOTAL PRECIPITATION FOR THE MONTH…………..0.04 DEPARTURE…..-1.79
TOTAL PRECIPITATION FOR THE YEAR (2024)…….41.25 DEPARTURE…..+4.81

————————————————————–

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN)/SUN(%)/PEAK GUST/VEC1/RMY GUST
PEAK GUST: F420C (Official)
VEC1: Vector #1 1-second gust
RMY:  R.M. Young #1 wind gust recording system (Instantaneous)
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

9/1   82/67/75/+6/T/244/31                28 SSW VEC1 27 SW  RMY 28
9/2   79/56/68/-1/0.00/644/82             31 NNW VEC1 31 NNW RMY 32
9/3   74/49/62/-6/0.00/766/98             23 NW  VEC1 23 NNW RMY 23
9/4   80/56/68/0/0.00/732/94              18 ESE VEC1 19 SE  RMY 18
9/5   77/58/68/0/0.00/737/95              20 ESE VEC1 19 ESE RMY 19
9/6   73/58/66/-2/0.00/240/31             22 E   VEC1 21 ENE RMY 23
9/7   77/56/67/0/0.04/301/39              34 WNW VEC1 31 WNW RMY 33
9/8   70/50/60/-7/0.00/753/98             35 W   VEC1 35 W   RMY 34
9/9   75/51/63/-4/0.00/727/95             31 WNW VEC1 28 WNW RMY 30
9/10  78/56/67/+1/0.00/717/94             21 NW  VEC1 20 SW  RMY 21
9/11  78/53/66/0/0.00/714/94              20 S   VEC1 19 S   RMY 18
9/12  82/58/70/+4/0.00/…/..             20 S   VEC1 19 S   RMY 20
9/13  85/59/72/+7/0.00/…/..             21 SSW VEC1 20 SSW RMY 20
9/14  81/61/71/+6/0.00/…/..             21 ENE VEC1 20 ENE RMY 21
9/15  78/60/69/+4/0.00/…/..             23 SE  VEC1 23 SE  RMY 25

9/16  The low since midnight is 55F, the daily normal low is 56F.

————————————————————–

SEPTEMBER DAILY RECORDS TO DATE

NONE.

————————————————————–

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