Thursday, July 18, 2024

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

THURSDAY, JULY 18, 2024
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0424E
SUNSET:  1917E

OVERNIGHT THUNDERSTORM, MOSTLY CLOUDY AND WARM….

A thunderstorm moved through overnight, dropping 0.92″ of rainfall
in a relatively short time period. Since then, we have remained dry,
aside from a light shower mid-morning that only resulted in an
additional trace of precipitation.

Skies today began overcast with stratus clouds overhead. These quickly
dissipated, but mid and high level clouds have been slower to depart.
Temperatures briefly dipped into the upper 60s early this morning during
the rain, but quickly rose back into the 70s. Since then, we have reached
the low 80s. The dew point, which began the day in the low 70s, has
fallen back into the upper 60s.

Winds, which were gusty during the thunderstorm, have since quieted down.
The average speed to this point is only 9mph, currently out of the
west-northwest. The peak gust for today took place at 12:02am, with a
value of 37mph.

Visibility was limited this morning due to low clouds and fog, but has been
improving as a drier air mass moves into place. The views have ranged from
5 miles up to 40 miles by the afternoon.

The maximum temperature so far today is 83F, which is 1 degree
above the normal high of 82F. The minimum temperature since
midnight is 69F, which is 5 degrees above the normal low of 64F.

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Today’s Observations:

7 A.M.
Weather: Fog, overcast stratus, few breaks in overcast all quadrants,
higher clouds visible, sun dimly visible
Temperature: 73F; Dew Point: 73F; Relative Humidity: 100%
Wind: W @ 7 kts
Sea-level pressure: 1010.8 mb; 29.85 in. Hg: rising, then more slowly
Visibility: 5 miles, fog
6-hr Max temp: 73F
6-hr Min temp: 69F
24-hr Precip:  0.92 inches
BHO SA 1155 E4 OVC 5F 108/73/73/2807/985/ FEW BINOVC ALQDS
HIER CLDS VSBL ALQDS SUN DMLY VSBL/ 8/6// 51010 70092 10073 20069

10 A.M.
Weather: Broken altocumulus, broken cirrus, few cumulus distant
SSE-S and WSW-NNW, few stratocumulus distant N-E-SE
Temperature: 76F; Dew Point: 70F; Relative Humidity: 82%
Wind: NW @ 8 kts
Sea-level pressure: 1011.4 mb; 29.87 in. Hg: falling, then rising
Visibility: 30 miles
3-hr Precip: Trace
BHO SA 1455 E160 BKN 250 BKN 30 114/76/70/3108/987/ FEW CU DSNT SSE-S
AND DSNT WSW-NNW FEW SC DSNT N-E-SE/ 8/851 53006 6000/

1 P.M.
Weather: Scattered cumulus, broken altocumulus, broken cirrus
Temperature: 82F; Dew Point: 68F; Relative Humidity: 64%
Wind: WNW @ 5 kts, wind light
Sea-level pressure: 1011.7 mb; 29.88 in. Hg: falling, then rising
Visibility: 40 miles
6-hr Max temp: 83F
6-hr Min temp: 73F
6-hr Precip: Trace
BHO SA 1755 40 SCT E170 BKN 250 BKN 40 117/82/68/2905/988/ WND LGT/
8/251 53003 6000/ 10083 20073

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SUMMARY FOR WEDNESDAY, JULY 17, 2024

TEMPERATURE (DEGREES F)
MAX…….89  NORMAL…..82
MIN…….71  NORMAL…..64
MEAN……80  NORMAL…..73

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL…………..+7
TOTAL DEPARTURE FOR THE MONTH…………………….+81 [+4.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2024 THRU JUN 2025)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE………0
TOTAL HEATING UNITS FOR THE MONTH…………….0  DEPARTURE……..-4
TOTAL HEATING UNITS FOR THE SEASON……………0  DEPARTURE……..-4
TOTAL HEATING UNITS LAST SEASON TO DATE……….0  DEPARTURE………0

COOLING DEGREE DAYS (SEASON: JAN 2024 THRU DEC 2024)
TOTAL COOLING UNITS FOR YESTERDAY……………15  DEPARTURE……..+7
TOTAL COOLING UNITS FOR THE MONTH…………..207  DEPARTURE…….+77
TOTAL COOLING UNITS FOR THE SEASON………….385  DEPARTURE……+116
TOTAL COOLING UNITS LAST SEASON TO DATE……..295  DEPARTURE…….+90

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)……….E38 W    @   11:59 P.M.
VECTOR #1 (1-Sec)……….36 W    @   11:59 P.M.
VECTOR #2 (1-Sec)……….36 W    @   11:59 P.M.
DAVIS #1……………….36 W    @   11:59 P.M.
DAVIS #2 ………………32 S    @   05:30 P.M.
RMY #1 (Instantaneous)…..37 W    @   11:59 P.M.
RMY #2 (Instantaneous)…..36 W    @   11:59 P.M.
MERLIN…………………36 WNW
RICHARDS (C5C) (Inst)…..OTS

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………25 W    @   11:59 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..25      @   11:59 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..24      @   11:59 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………25 WSW  @   11:59 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………24 S    @   05:32 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..24 W    @   11:59 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..24 W    @   11:59 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE……..OTS

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL…….9.7 SSW [232 total miles] VECTOR #1……………..9.9
VECTOR #2…………….10.5
DAVIS #1………………9.8 SW
DAVIS #2……………..10.5 SW
RMY #1………………..9.6 SW
RMY #2……………….10.5 SW
RICHARDS (C5C)…………OTS

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.92 DEPARTURE…..+0.81
TOTAL PRECIPITATION FOR THE MONTH…………..2.12 DEPARTURE…..+0.22
TOTAL PRECIPITATION FOR THE YEAR (2024)…….37.80 DEPARTURE…..+8.67

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PRELIMINARY CLIMATE SUMMARY FOR JULY 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

7/1   77/63/70/-1/0.07/722/79             29 N   VEC1 27 N   RMY 28 TSTM
7/2   80/60/70/-1/0.00/886/97             20 N   VEC1 20 N   RMY 19
7/3   84/62/73/+1/0.00/856/94             25 S   VEC1 25 S   RMY 26
7/4   85/62/74/+2/0.04/392/43             28 SSW VEC1 28 SSW RMY 28
7/5   84/68/76/+4/0.22/146/16             29 SSW VEC1 29 SSW RMY 29
7/6   77/71/74/+2/0.10/009/01             31 SW  VEC1 33 SSW RMY 33
7/7   88/72/80/+8/0.00/345/38             15 SW  VEC1 15 SW  RMY 14
7/8   91/71/81/+9/0.00/780/86             17 NW  VEC1 18 NW  RMY 18
7/9   88/72/80/+7/T/534/59                26 SSW VEC1 27 SSW RMY 29
7/10  88/72/80/+7/0.00/552/61             38 SSW VEC1 37 SSW RMY 38
7/11  87/71/79/+6/0.01/470/52             41 SSW VEC1 40 SSW RMY 41
7/12  85/69/77/+4/0.05/…/..             32 SW  VEC1 32 SW  RMY 32
7/13  80/72/76/+3/0.64/…/..             28 SW  VEC1 25 SW  RMY 26
7/14  88/69/79/+6/0.00/…/..             18 SW  VEC1 18 SW  RMY 19
7/15  92/70/81/+8/0.07/…/..             28 WSW VEC1 27 WSW RMY 28 TSTM
7/16  92/72/82/+9/0.00/…/..             33 SW  VEC1 34 SW  RMY 34
7/17  89/71/80/+7/…/…/..              38 W   VEC1 36 W   RMY 37 TSTM

7/18  The low since midnight is 69F, the daily normal low is 64F.

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JULY DAILY RECORDS TO DATE

NONE.

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

RECORDS FOR JULY 18
HIGH 96F IN 1991, 1999
LOW 54F IN 1892, 1956, 1971
PRECIP 1.65 INS IN 2000
WIND 43e MPH SW IN 1949

RECORDS FOR JULY 19
HIGH 96F IN 1977, 1991
LOW 50F IN 1890
PRECIP 1.10 INS IN 1951
WIND 63 MPH SSW IN 1982

TODAY’S REPORT PREPARED BY: Joshua Polen