Friday, May 12, 2023

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

FRIDAY, MAY 12, 2023
ALL TIMES ARE IN EASTERN STANDARD TIME (EST)
SUNRISE: 0426E
SUNSET:  1856E

VARIABLE AMOUNTS OF SUN AND CLOUDS, CONTINUED WARM AND MAINLY DRY…

The day started with plenty of sunshine, but a brief band of clouds,
and even a brief rain shower moved through during the mid morning
period. Once this band moved off to the southwest, sunshine returned
and has been the theme through the afternoon. However, as the
temperature reached it’s convective threshold, cumulus clouds have
popped up in the warm surface air mass.

The temperature has reached the low 80s this afternoon, which is
a little more than 15F degrees above normal for this date.

The wind was mainly on the light side this morning, but has since
increased thanks to mixing from aloft. Gusts of around 30mph have
occurred at times. The average speed for the day has been around
12mph, generally out of a west-northwesterly direction.

Visibility has been limited due to haziness, likely from pollen
this time, as the wildfire smoke from the past couple of days has
finally moved out. The view has only been around 30-40 miles all
day.

The maximum temperature so far today is 83F, this is 17 degrees
above the normal high of 66F. The low since midnight is 57F,
which is 10 degrees above the normal low of 47F.

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Today’s Observations:

7 A.M.
Weather: Broken altocumulus/castellanus, thin broken cirrus,
virga distant WNW-N
Temperature: 65F; Dew Point: 47F; Relative Humidity: 52%
Wind: WNW @ 9 kts
Sea-level pressure: 1017.5 mb; 30.05 in. Hg: rising, then more rapidly
Visibility: 30 miles, hazy
6-hr Max temp: 65F
6-hr Min temp: 57F
24-hr Precip:  Trace
BHO SA 1155 E150 BKN 250 -BKN 30 175/65/47/3009/005/ VIRGA DSNT WNW-N
HAZY/ 8/081 53011 70000 10065 20057

10 A.M.
Weather: Clear, few cumulus distant NW-N, cew altocumulus/castellanus
distant NNE-SE-SSW
Temperature: 75F; Dew Point: 49F; Relative Humidity: 40%
Wind: W @ 12G19 kts
Sea-level pressure: 1016.5 mb; 30.02in. Hg: falling, then more rapidly
Visibility: 40 miles, hazy
3-hr Precip:  Trace
BHO SA 1455 CLR 40 165/75/49/2712G19/002/ FEW CU DSNT NW-N
FEW AC/ACC DSNT NNE-SE-SSW HAZY/ 8/280 58010 6000/

1 P.M.
Weather: Scattered cumulus
Temperature: 81F; Dew Point: 48F; Relative Humidity: 32%
Wind: WNW @ 12G19 kts
Sea-level pressure: 1015.4 mb; 29.98 in. Hg: falling, then more rapidly
Visibility: 40 miles, hazy
6-hr Max temp: 83F
6-hr Min temp: 65F
6-hr Precip:  Trace
BHO SA 1755 70 SCT 40 154/81/48/3012G19/998/ HAZY/
8/200 58011 6000/ 10083 20065

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SUMMARY FOR THURSDAY, MAY 11, 2023

TEMPERATURE (DEGREES F)
MAX…….81   NORMAL…..66
MIN…….53   NORMAL…..47
MEAN……67   NORMAL…..56

DEPARTURE FROM 30-YEAR (1991-2020) NORMAL……..+11
TOTAL DEPARTURE FOR THE MONTH………………..+12 [+0.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON: JUL 2022 THRU JUN 2023)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE…….-10
TOTAL HEATING UNITS FOR THE MONTH……………92  DEPARTURE…….-25
TOTAL HEATING UNITS FOR THE SEASON…………5063  DEPARTURE……-941
TOTAL HEATING UNITS LAST SEASON TO DATE…….5521  DEPARTURE……-458

COOLING DEGREE DAYS (SEASON: JAN 2023 THRU DEC 2023)
TOTAL COOLING UNITS FOR YESTERDAY…………….2  DEPARTURE……..+1
TOTAL COOLING UNITS FOR THE MONTH…………….2  DEPARTURE……..-3
TOTAL COOLING UNITS FOR THE SEASON…………..11  DEPARTURE……..+3
TOTAL COOLING UNITS LAST SEASON TO DATE……….0  DEPARTURE…….+11

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)……….E30 W   @   04:03 P.M.
VECTOR #1 (1-Sec)……….30 W   @   04:03 P.M.
VECTOR #2 (1-Sec)……….32 WNW @   04:04 P.M.
DAVIS #1……………….30 WSW @   04:03 P.M.
DAVIS #2 ………………30 W   @   04:03 P.M.
RMY #1 (Instantaneous)…..30 WNW @   01:08 P.M.
RMY #2 (Instantaneous)…..34 WNW @   04:04 P.M.
MERLIN…………………30 W
RICHARDS (C5C) (Inst)……31     @   04:06 P.M.

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………24 WNW @   04:06 P.M.
MAXIMUM 2-MINUTE VECTOR #1 AVERAGE…………..22     @   04:06 P.M.
MAXIMUM 2-MINUTE VECTOR #2 AVERAGE…………..23     @   04:06 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………24 WNW @   04:06 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………23 WNW @   04:06 P.M.
MAXIMUM 2-MINUTE RMY #1 AVERAGE……………..22 WNW @   04:06 P.M.
MAXIMUM 2-MINUTE RMY #2 AVERAGE……………..23 WNW @   04:06 P.M.
MAXIMUM 2-MINUTE RICHARDS (C5C) AVERAGE………23     @   04:06 P.M.

AVERAGE WIND SPEED AND DIRECTION:
CONTACTING/OFFICIAL………10.1 WNW [243 total miles] VECTOR #1……………….10.2
VECTOR #2……………….10.8
DAVIS #1………………..10.4 W
DAVIS #2………………..10.6 WNW
RMY #1…………………. 9.9 W
RMY #2………………….10.7 W
RICHARDS (C5C)…………..10.5

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….TRACE DEPARTURE…..-0.12
TOTAL PRECIPITATION FOR THE MONTH…………..0.45 DEPARTURE…..-0.88
TOTAL PRECIPITATION FOR THE YEAR…………..18.65 DEPARTURE…..-1.46

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/…/..        26 WNW  VEC1 27 W   RMY 28
5/8   74/49/62/+7/0.03/0.0/…/..         32 NW   VEC1 33 NW  RMY 35
5/9 60/45/53/-3/0.00/0.0/…/..         24 NE   VEC1 25 NE  RMY 25
5/10  72/51/62/+6/0.00/0.0/…/..         25 WSW  VEC1 26 WSW RMY 26
5/11  81/53/67/+11/T/0.0/…/..           30 W    VEC1 30 W   RMY 30

5/12 The low since midnight is 57, the daily normal low is 47F

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

RECORDS FOR MAY 12
HIGH 88F IN 2001
LOW 29F IN 1907
PRECIP 1.49 INCHES IN 1968
SNOW TRACE IN 2019
PEAK GUST 76 MPH S IN 1974

RECORDS FOR MAY 13
HIGH 85F IN 1947
LOW 32F IN 2020
PRECIP 2.39 INCHES IN 2006
PEAK GUST 49 MPH NNW IN 1965

TODAY’S REPORT PREPARED BY: Matt Douglas