Friday, July 24, 2020

| July 24, 2020 | Reply

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

FRIDAY, JULY 24, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

THINNING OVERCAST WITH DECREASING DEW POINTS
ATOP GREAT BLUE HILL…

A line of early evening thunderstorms rolled through
yesterday bringing with it frequent lightning,
thunder and tropical downpours. 0.48 inches of rain
was measured at the 7AM observation. This was
another dose of beneficial rainfall to chip away
at this month’s (and year’s) deficits.

It was an overcast morning with dew point temperatures
in the upper-60s. As the morning progressed, dew points
slipped from the upper-60s to the low/mid-60s by 1 PM.
This is a very welcomed reprieve from the muggy and
stuffy conditions that dominated this week.

Clouds have had a firm grip on the region, but a very
gradual thinning pattern has been noted. Splashes of
sun have poked through breaks in overcast with the
sun becoming more dimly visible by the early afternoon.
Winds have remained light out of the northeast for the
duration of today achieving a max gust of only 18 MPH.

The high so far today is 80 degrees. This is 1
degree below the daily normal high of 81F. The
low since midnight is 68F, which is 5 degrees above
the daily normal low of 63F

Today’s Observations:

7 A.M.
Weather: Overcast Altostratus/Altocumulus (breaks in
overcast overhead)
Temperature: 70F; Dew Point: 67F; Relative Humidity: 90%
Wind: North at 5 kts (winds light)
Sea-level pressure: 30.08 ins. Hg: rising, then more slowly
Visibility: 25 miles, thin fog
6-hr Max temp: 72F
6-hr Min temp: 68F
24-hr Precip: 0.48 ins.
BHO SA 1155 E120 OVC 25 187/70/67/3505/008/ BINOVC OVHD
THN F ALQDS WND LGT/ 8/05/ 51016 70048 10072 20068

10 A.M.
Weather: Scattered Altocumulus, (thin) Broken Cirrus, (few
cumulus south to north)
Temperature: 77F; Dew Point: 63F; Relative Humidity: 63%
Wind: ENE at 6 kts (wind light)
Sea-level pressure: 30.03 ins. Hg: rising then more rapidly
Visibility: 35 miles (hazy)
3-hr Precip: 0.00 ins.
BHO SA 1455 120 SCT E230 –BKN 35 171/77/63/0706/003/ FEW CU S-N
HAZY WND LGT/ 8/132 53016

1 P.M.
Weather: Scattered Cumulus, (thin) Overcast Cirrostratus
(breaks in overcast northeast to southeast, sun dimly visible)
Temperature: 79F; Dew Point: 64F; Relative Humidity: 61%
Wind: NE at 6 kts (wind light)
Sea-level pressure: 30.03 ins. Hg: falling, then more rapidly
Visibility: 45 miles (hazy)
6-hr Max temp: 80F
6-hr Min temp: 70F
6-hr Precip: 0.00 ins.
BHO SA 1755 35 SCT E250 –OVC 45 168/79/64/0506/003/ BINOVC NE-SE
SUN DMLY VSBL HAZY WND LGT/ 8/207 58003 10080 20070

SUMMARY FOR THURSDAY, JULY 23, 2020

TEMPERATURE (DEGREES F)
MAX…..88   NORMAL…..81
MIN…..68   NORMAL…..63
MEAN….78   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL……………… +6
TOTAL DEPARTURE FOR THE MONTH…………….. +43 [+1.7 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………13  DEPARTURE……. +5
TOTAL COOLING UNITS FOR THE MONTH…………..186  DEPARTURE…….+25
TOTAL COOLING UNITS FOR THE SEASON………….370  DEPARTURE…….+80
TOTAL COOLING UNITS LAST SEASON TO DATE……..326  DEPARTURE…….+44

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..31 N   AT 4:04 P.M.
AERO…………………….32 N   AT 3:57 P.M.
ASOS…………………….30 N   AT 4:00 P.M.
DAVIS……………………30 N   AT 3:59 P.M
RMY 21 MERLIN 31
FASTEST MILE FOR YESTERDAY………………….22 NNW AT 4:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….21 NNW AT 4:04 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………21 NNW AT 3:59 P.M.
AVERAGE WIND SPEED AND DIRECTION……………8.6 SW
ASOS……………………8.8
DAVIS…………………..8.5 SW [223 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……0.48  DEPARTURE……+0.35
ASOS…………….0.49
TOTAL PRECIPITATION FOR THE MONTH…………1.71  DEPARTURE……-1.15
ASOS…………….1.79
TOTAL PRECIPITATION FOR THE YEAR…………29.06  DEPARTURE……-0.77
ASOS……………29.80

PRELIMINARY CLIMATE SUMMARY FOR JULY 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

07/01  76/63/70/0/0.00/228/25              16 E    AERO 14 E    RMY 14  TSTM
07/02  86/61/74/4/0.00/803/88              30 WSW  AERO 25 WSW  RMY 33
07/03  73/60/67/-4/0.00/091/10             30 NE   AERO 28 NE   RMY 30
07/04  79/60/70/-1/0.00/565/62             16 S    AERO 16 S    RMY 16
07/05  83/63/73/+2/0.54/373/41             24 NW   AERO 30 NW   RMY 26  TSTM
07/06  73/60/67/-4/0.00/…/..             20 ENE  AERO 16 NNE  RMY 18
07/07  78/60/69/-2/0.00/…/..             25 S    AERO 25 S    RMY 26
07/08  83/64/74/+2/0.00/…/..             32 SSW  AERO 32 SSW  RMY 32
07/09  89/70/80/+8/0.00/…/.              24 S    AERO 23 S    RMY 22
07/10  83/70/77/+5/0.05/…/..             30 SSE  AERO 32 SSE  RMY N/A
07/11  85/70/78/+6/0.00/…/..             39 S    AERO 39 S    RMY 38
07/12  86/70/78/+6/0.00/…/..             28 WSW  AERO 28 WSW  RMY 29
07/13  82/69/76/+4/0.23/…/..             30 SSE  AERO 31 SSE  RMY 30  TSTM
07/14  78/63/71/-1/0.00/…/..             26 ENE  AERO 25 ENE  RMY 26
07/15  72/59/66/-6/0.00/…/..             21 NE   AERO 21 NE   RMY N/A
07/16  73/57/65/-7/0.00/…/..             21 E    AERO 21 E    RMY 19
07/17  71/57/64/-8/0.19/…/..             24 SSW  AERO 24 SSW  RMY 25
07/18  89/66/78/+6/0.00/…/..             18 W    AERO 17 W    RMY 19
07/19  92/69/81/+9/0.00/…/..             28 S    AERO 28 S    RMY 26
07/20  91/72/82/+10/T/…/..               25 SSW  AERO 25 SSW  RMY N/A
07/21  88/68/78/+6/0.00/…/..             25 W    AERO 25 W    RMY 24
07/22  80/67/74/+2/…/…/..              16 ENE  AERO M  M    RMY 16
07/23  88/68/78/+6/0.48/…/..             31 N    AERO 32 N    RMY 31 TSTM

07/24 The low since midnight is 68F, the daily normal low is 63F

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

RECORDS FOR JULY 24
HIGH 96F IN 1987
LOW 49F IN 1893,1912
PRECIP 2.27 INS IN 2008
PEAK GUST 46 MPH NE IN 2009

RECORDS FOR JULY 25
HIGH 96F IN 2016
LOW 51F IN 1901,1953
PRECIP 2.25 INS IN 1990
PEAK GUST 88 MPH NW IN 1972

TODAY’S REPORT PREPARED BY: Andrew Swanson

Category: Daily Discussions

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