Monday, May 3, 2021

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

MONDAY, MAY 3, 2021
ALL TIMES ARE IN EASTERN STANDARD TIME
SUNRISE: 0436E
SUNSET:  1846E

COOLER WITH A MIX OF SUN AND CLOUDS….

Today is cooler compared to yesterday thanks to an
onshore wind and an increase in a thickening cloud cover.

Visibility has been between 50-60 miles today with a
bit of a haziness, likely due in part to pollen in
the air.

Wind has been mostly on the light side, with an
occasional gust approaching 20 mph. The average speed
sicne 7 A.M. has only been around 7 mph. Unlike
yesterday’s prevailing direction of west-southwest,
today’s prevailing direction so far has been northeast.
This of course is responsible for cooler temperatures
compared to yesterday.

The high so far today is 67F, this is 4 degrees above the
normal high of 63F. The low since midnight is 53F, which
is 9 degrees above the daily normal low of 44F.

Today’s Observations:

7 A.M.
Weather: Broken altocumulus, broken cirrus
Temperature: 57F; Dew Point: 43F; Relative Humidity: 59%
Wind: N at 5 kts, wind light
Sea-level pressure: 29.92 in Hg, rising, then more rapidly
Visibility: 50 miles
6-hr Max temp: 57F
6-hr Min temp: 53F
24-hr Precip: 0.01 ins.
24-hr Snow: 0.0 ins.
Snow Depth: 0.0 ins.
BHO SA 1155 E85 BKN 250 BKN 50 132/57/43/3605/992/ WND LGT/
8/052 53017 6000/ 70001 10057 20053

10 A.M.
Weather: Broken altostratus, broken cirrostratus, broken cirrus
Temperature: 63F; Dew Point: 34F; Relative Humidity: 33%
Wind: E @ 7G16 kts
Sea-level pressure: 29.91 in Hg; rising then falling
Visibility: 60 miles
3-hr Precip: 0.0 ins.
3-hr Snow: 0.00 ins.
BHO SA 1455 E100 BKN 220 BKN 250 BKN 60 128/63/34/0807G16/991/
8/055 58004

1 P.M.
Weather: Scattered altostratus castellanus, broken altocumulus,
broken cirrostratus, thin overcast cirrus
Temperature: 67F, Dew point: 37F; Relative Humidity: 32%
Wind: NE @ 8G17 kts
Sea-level pressure: 29.89 in Hg; steady then falling
Visibility: 50 miles
6-hr Max temp: 67F
6-hr Min temp: 57F
6-hr Precip: 0.00 ins.
6-hr Snow: 0.0 ins.
Snow Depth: 0 ins.
BHO SA 1755 80 SCT E100 BKN 200 BKN 250 -OVC 50 123/67/37/0408G17/989/
8/085 58005 10067 20057

SUMMARY FOR SUNDAY, MAY 2, 2021

TEMPERATURE (DEGREES F)
MAX…….76     NORMAL…..62
MIN…….48     NORMAL…..44
MEAN……62     NORMAL…..53

DEPARTURE FROM 30-YEAR (1981-2010) NORMAL…….. +9
TOTAL DEPARTURE FOR THE MONTH……………….. +6 [+2.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL THRU JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………… 3  DEPARTURE…….-9
TOTAL HEATING UNITS FOR THE MONTH……………18  DEPARTURE…….-7
TOTAL HEATING UNITS FOR THE SEASON…………5359  DEPARTURE…..-701
TOTAL HEATING UNITS LAST SEASON TO DATE…….5537  DEPARTURE…..-178

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

PEAK WIND GUST (MPH):
                     420C/Official…………..41 SW  @  1:47 A.M.
                     AEROVANE (south tower)…..41 SW  @  1:47 A.M.
                     ASOS…………………..42 SSW @  1:47 A.M.
                     DAVIS #1……………….42 SW  @  1:47 A.M.
                     DAVIS #2 (south tower)…..43 SW  @  1:47 A.M.
                     RMY……………………46     @  1:45 A.M.
                     VECTOR…………………47     @  1:47 A.M.
                     MERLIN…………………N/A

FASTEST MILE:
CONTACTING ANEMOMETER/OFFICIAL………………27 W   @  6:18 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….26 W   @ 12:42 P.M.
MAXIMUM 2-MINUTE DAVIS #1 AVERAGE……………29 W   @ 12:42 P.M.
MAXIMUM 2-MINUTE DAVIS #2 AVERAGE……………27 SW  @  1:47 A.M.
MAXIMUM 2-MINUTE RMY AVERAGE………………..24 W   @  6:18 P.M.
MAXIMUM 2-MINUTE VECTOR AVERAGE……………..27     @ 12:40 P.M.

AVERAGE WIND SPEED AND DIRECTION:
                     CONTACTING/OFFICIAL……14.1 WSW [339 total miles]                     ASOS…………………13.8
                     DAVIS #1……………..14.3 WSW
                     DAVIS #2……………..14.4 WSW
                     RMY………………….13.4 WSW
                     VECTOR……………….14.0

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST):
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…….0.01  DEPARTURE….-0.12
                             ASOS………….0.00
TOTAL PRECIPITATION FOR THE MONTH………….0.07  DEPARTURE….-0.18
                             ASOS………….0.05
TOTAL PRECIPITATION FOR THE YEAR………….15.12  DEPARTURE….-3.67
                              ASOS………..15.33

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

04/01   56/30/43/+2/0.89/T/000/00        44 NW   AERO 51 NW   RMY 49
04/02   37/24/31/-10/0.00/0.0/614/80     28 NW   AERO 32 NNW  RMY 30
04/03   48/23/36/-6/0.00/0.0/755/98      24 NW   AERO 25 NW   RMY 26
04/04   58/33/46/+4/0.00/0.0/734/95      38 NNW  AERO 41 NNW  RMY 41
04/05   57/41/49/+6/T/T/031/04           41 NNW  AERO 48 NNW  RMY 50
04/06   61/40/51/+8/0.00/0.0/412/53      26 NNW  AERO 25 NNW  RMY 31
04/07   57/41/49/+6/0.00/0.0/391/50      23 ENE  AERO 21 ENE  RMY 22
04/08   59/43/51/+7/0.00/0.0/745/95      22 ENE  AERO 22 ENE  RMY 24
04/09   69/42/56/+12/0.00/0.0/707/90     24 S    AERO  M   M  RMY 26
04/10   75/43/59/+14/0.00/0.0/576/73     26 SSW  AERO 28 SSW  RMY 30
04/11   53/40/47/+2/T/0.0/000/00         33 ENE  AERO 33 ENE  RMY 34
04/12   46/37/42/-3/0.05/0.0/000/00      36 ENE  AERO 37 ENE  RMY 41
04/13   56/37/47/+1/T/0.0/415/52         31 NE   AERO 30 NE   RMY 33
04/14   56/42/49/+3/0.00/0.0/729/91      22 ESE  AERO 23 ESE  RMY 22
04/15   51/37/44/-3/0.30/0.0/016/02      26 ESE  AERO 25 ESE  RMY 28
04/16   39/31/35/-12/2.22/3.6/000/00     48 NNW  AERO 58 NNW  RMY 58
04/17   45/34/40/-7/0.07/T/040/05        27 NNW  AERO 30 NNW  RMY 29
04/18   60/38/49/+1/0.00/0.0/666/82      28 NW   AERO 28 NW   RMY 31
04/19   66/44/55/+7/T/0.0/…/..         22 SSW  AERO 25 SSW  RMY 28
04/20   72/45/59/+10/0.00/0.0/…/..     38 SW   AERO 37 WSW  RMY 40
04/21   68/32/50/+1/0.48/*T/…/..       45 S    AERO 51 S    RMY 51 TSTM
04/22   44/28/36/-13/T/T/…/..          54 W    AERO 55 W    RMY 59
04/23   58/32/45/-5/0.00/0.0/…/..      47 W    AERO 48 W    RMY 52
04/24   70/44/57/+7/0.00/0.0/…/..      33 WNW  AERO 37 WNW  RMY 55
04/25   54/44/49/-1/0.20/0.0/…/..      23 NNE  AERO 20 SSW  RMY 24
04/26   55/40/48/-3/0.00/0.0/…/..      39 NW   AERO 40 NW   RMY 43
04/27   67/38/53/+2/T/0.0/…/..         26 W    AERO 28 WNW  RMY 28
04/28   63/46/55/+3/0.18/0.0/…/..      18 ENE  AERO 21 WNW  RMY 20
04/29   54/44/48/-4/0.42/0.0/…/..      18 ENE  AERO 20 NNE  RMY 19
04/30   62/41/52/0/0.08/0.0/…/..       58 WNW  AERO 60 WNW  RMY 65

*Trace of frozen on 04/21 was hail, 1/8″ diameter, this does not
count as snowfall.

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

05/01   62/38/50/-3/0.06/0.0/…/..       31 WNW  AERO 35 WNW  RMY 40
05/02   76/48/62/+9/0.01/0.0/…/..       41 SW   AERO 41 SW   RMY 46

05/03 The low since midnight is 53F, the daily normal low is 44F

 

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

RECORDS FOR MAY 3
HIGH 92F IN 2001
LOW 31F IN 1888
PRECIP 2.25 INS IN 1900
SNOWFALL TRACE IN 1908, 1985
PEAK GUST 71 MPH W IN 2002

RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.67 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966

TODAY’S REPORT PREPARED BY: Matt Douglas