Friday, May 19, 2023

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

FRIDAY, MAY 19, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0419E
SUNSET:  1903E

DRY, MILD DAY WILL SUNNY SKIES AND OBSCURED VISIBILITY…

Today was a dry and mild day with seasonable temperatures. The
morning was much warmer than yesterday’s record breaking low
temperature of 34F. The high so far today is 66F, which is 1
degree below our normal maximum temperature of 67F. Our low since
midnight is 42F, which is 7 degrees below our normal low
temperature of 49F.
Conditions have been breezy on the hill today with an estimated
peak gust of 32 MPH so far today.

Visibility has been obscured down to 40-45 miles, most likely from
a thin smoke layer traveling down from wildfires in Canada.
Cloud cover increased as pressure decreased throughout the day but
all and all it was a nice sunny day with a mixture of cirrus and
cumulus clouds.

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Today’s Observations:

7 A.M.
Weather: Clear, few cirrostratus NNE-SSE, thin smoke layer aloft
all quadrants
Temperature: 50F; Dew Point: 41F; Relative Humidity: 69%
Wind: SW @ 14G22 kts
Sea-level pressure: 1030.0 mb; 30.41 in. Hg: rising steadily
Visibility: 40 miles
6-hr Max temp: 50F
6-hr Min temp: 42F
24-hr Precip:  0.00 ins.
BHO SA 1155 CLR 40 030/50/41/2114G22/041/ FEW CS NNE-SSW THN K
LYR ALF ALQDS/ 8/005 52011 10050 20042

10 A.M.
Weather: Scattered cirrostratus, few cumulus SSW-NW, thin smoke
layer aloft all quadrants
Temperature: 62F; Dew Point: 42F; Relative Humidity: 56%
Wind: SW @ 10G23 kts,
Sea-level pressure: 1029.4 mb; 30.40 in. Hg: steady then falling
Visibility: 45 miles
3-hr Precip:  0.00 ins.
BHO SA 1455 250 SCT 45 294/62/42/2110G23/040/ FEW CU SSW-NW THN K
LYR ALF ALQDS/ 8/105 58006

1 P.M.
Weather: Scattered cumulus, scattered cirrus, broken cirrocumulus,
thin smoke layer aloft all quadrants
Temperature: 66F; Dew Point: 44F; Relative Humidity: 45%
Wind: SSW @ 13G28 kts, Peak Wind: 28 kts SSW @ 12:49 P.M.
Sea-level pressure: 1027.3mb; 30.34 in. Hg: falling unsteadily
Visibility: 40 miles
6-hr Max temp: 66F
6-hr Min temp: 50F
6-hr Precip:  0.00 ins.
BHO SA 1755 42 SCT 200 SCT 250 BKN 40 273/66/44/2013G28/034/ THN K
LYR ALF ALQDS PK WND 2028/49/ 8/406 57021 10066 20050

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SUMMARY FOR THURSDAY, MAY 18, 2023

TEMPERATURE (DEGREES F)
MAX…….64   NORMAL…..67
MIN…….34   NORMAL…..49
MEAN……49   NORMAL…..58

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL………-9
TOTAL DEPARTURE FOR THE MONTH………………..+34 [+1.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY……………16  DEPARTURE……..+8
TOTAL HEATING UNITS FOR THE MONTH…………..137  DEPARTURE…….-38
TOTAL HEATING UNITS FOR THE SEASON…………5108  DEPARTURE……-954
TOTAL HEATING UNITS LAST SEASON TO DATE…….5533  DEPARTURE……-425

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….0  DEPARTURE……..-1
TOTAL COOLING UNITS FOR THE MONTH……………16  DEPARTURE……..+7
TOTAL COOLING UNITS FOR THE SEASON…………..25  DEPARTURE…….+13
TOTAL COOLING UNITS LAST SEASON TO DATE………24  DEPARTURE……..+1

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

F420C (Official)……….E26 SSW @   6:36 P.M.
VECTOR #1 (1-Sec)……….28 SSW @   6:03 P.M.
VECTOR #2 (1-Sec)……….28 SSW @   5:17 P.M.
DAVIS #1……………….28 S   @   6:37 P.M.
DAVIS #2 ………………32 S   @   6:24 P.M.
RMY #1 (Instantaneous)…..28 NNW @   5:17 P.M.
RMY #2 (Instantaneous)…..29 SSW @   5:17 P.M.
MERLIN…………………26 SSW
RICHARDS (C5C) (Inst)……27     @   6:37 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………20 SSW @   5:17 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..21     @   4:53 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..21     @   5:18 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………20 SSW @   4:53 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………21 S   @   6:29 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..21 SW  @   4:53 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..22 NNW @   5:18 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………19     @   6:04 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………10.7 SSW [256 total miles] VECTOR #1……………….10.7
VECTOR #2……………….11.2
DAVIS #1………………..10.5 WSW
DAVIS #2………………..11.1 WSW
RMY #1………………….10.5 WSW
RMY #2………………….11.2 W
RICHARDS (C5C)…………..10.6

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..0.00 DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH…………..0.45 DEPARTURE…..-1.69
TOTAL PRECIPITATION FOR THE YEAR…………..18.65 DEPARTURE…..-2.27

SNOWFALL (INCHES) THROUGH THIS MORNING (EST):
TOTAL SNOWFALL 24 HRS ENDING 7 A.M…………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE MONTH………………..0.0 DEPARTURE…….0.0
TOTAL SNOWFALL FOR THE SEASON (2022-2023)……34.9 DEPARTURE…..-34.8

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PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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

5/1   63/45/54/+1/0.04/0.0/540/64         44 SSE  VEC1 46 SSE RMY 48
5/2   57/43/50/-4/0.22/0.0/144/17         33 S    VEC1 34 S   RMY 35
5/3   55/42/49/-5/0.01/0.0/093/11         25 E    VEC1 25 E   RMY 25
5/4   45/40/43/-11/0.07/0.0/009/01        29 NE   VEC1 29 NE  RMY 29
5/5   59/43/51/-4/0.07/0.0/367/43         18 NE   VEC1 19 NE  RMY 19
5/6   74/43/59/+4/0.00/0.0/847/99         25 NW   VEC1 26 NW  RMY 26
5/7   78/52/65/+10/0.01/0.0/789/92        26 WNW  VEC1 27 W   RMY 28
5/8   74/49/62/+7/0.03/0.0/800/93         32 NW   VEC1 33 NW  RMY 35
5/9   60/45/53/-3/0.00/0.0/819/95         24 NE   VEC1 25 NE  RMY 25
5/10  72/51/62/+6/0.00/0.0/830/96         25 WSW  VEC1 26 WSW RMY 26
5/11  81/53/67/+11/T/0.0/729/84           30 W    VEC1 30 W   RMY 30
5/12  84/57/71/+14/T/0.0/687/79           31 WNW  VEC1 35 WNW RMY 34
5/13  81/58/70/+13/0/0.0/715/82           28 NNW  VEC1 30 NNW RMY 35
5/14  66/47/57/0/0.00/0.0/822/94          28 NNW  VEC1 29 NNW RMY 31
5/15  72/45/59/+2/0.00/0.0/675/77         33 W    VEC1 35 W   RMY 34
5/16  80/55/68/+10/0.00/0.0/…/..        38 SW   VEC1 39 SW  RMY 41
5/17  62/37/50/-8/0.00/0.0/…/..         36 NNW  VEC1 37 NNW RMY 40
5/18  64/34/49/-9/0.00/0.0/…/..         26 SSW  VEC1 28 SSW RMY 28

5/19 The low since midnight is 42F, the daily normal low is 49F

DAILY RECORDS

05/18/2023: NEW RECORD LOW MINIMUM TEMPERATURE OF 34F,
THIS BEATS THE OLD RECORD OF 35F SET IN 2002

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

RECORDS FOR MAY 19
HIGH 91F IN 1962
LOW 34F IN 2002
PRECIP 1.54 INCHES IN 1900
PEAK GUST 58 MPH NW IN 1964

RECORDS FOR MAY 20
HIGH 91F IN 1975,1996
LOW 37F IN 1948, 2002
PRECIP 1.65 INCHES IN 1969
PEAK GUST 57 MPH S IN 1963, WNW IN 1982

TODAY’S REPORT PREPARED BY: Kaitlin Geagan