Monday, May 4, 2020

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 4, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER WARM DAY WITH DRY AIR AND EXCELLENT VISIBILITY….

Yesterday was the warmest day of the year thus far with
a high of 78F. We also got our first cooling degree day
units of the season!

Warm weather continued today after a few early morning
showers gave way to sunny skies for a time this morning.
Clouds have since returned with a few more light showers
early this afternoon. These showers are the leading edge
of changes to cooler weather ahead.

The air is very dry with dew points in the low to mid 30s.
This is affording us some very clear air for this time of
year having excellent visibility of 70 miles all day. A
treat with comfortable temperatures!

Today marks the 3rd day in a row reaching at least 70
degrees.The high so far today is 72F, this is 9 degrees
above our daily normal high temperature of 63F. The low
since midnight is 56F, which is 12 degrees above the
daily normal low of 44F.

Today’s Observations:

7 A.M.
Weather: Broken altocumulus, thin broken cirrus, few cumulus
distant NNW-N
Temperature: 60F; Dew Point: 35F; Relative Humidity: 38%
Wind: W at 8 kts
Sea-level pressure: 29.61 ins. Hg: falling then rising
Visibility: 70 miles
6-hr Max temp: 60F
6-hr Min temp: 56F
24-hr Precip:   TRACE
24-hr Snowfall: 0.0 ins.
BHO SA 1155 E120 BKN 250 –BKN 70 027/60/35/2808/961/
FEW CU DSNT NNW-N/ 8/271 55005 6000 70000 10060 20056

10 A.M.
Weather: Scattered cumulus, scattered altocumulus
Temperature: 68F; Dew Point: 33F; Relative Humidity: 27%
Wind: NW at 14G24 kts
Sea-level pressure: 29.59 ins. Hg: falling then rising
Visibility: 70 miles
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 50 SCT 130 SCT 70 019/68/33/3114G24/959/ 8/171 55008

1 P.M.
Weather: Broken cumulus, broken altocumulus, higher clouds
visible distant E-SE, virga all quadrants
Temperature: 66F; Dew Point: 32F; Relative Humidity: 27%
Wind: WNW at 13G22 kts
Sea-level pressure: 29.57 ins. Hg: falling, then more slowly
Visibility: 70 miles
6-hr Max temp: 72F
6-hr Min temp: 60F
6-hr Precip:   TRACE
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E60 BKN 120 BKN 70 012/66/32/3013G22/957/
HIR CLDS VSBL DSNT NE-SE VIRGA ALQDS RW-B45E50/ 8/271
56007 6000 10072 20060

SUMMARY FOR SUNDAY, MAY 3, 2020

TEMPERATURE (DEGREES F)
MAX…..78   NORMAL…..63
MIN…..55   NORMAL…..44
MEAN….67   NORMAL…..53

DEPARTURE FROM 30-YEAR NORMAL………………+14
TOTAL DEPARTURE FOR THE MONTH………………+22 [+7.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………….0  DEPARTURE…….-12
TOTAL HEATING UNITS FOR THE MONTH……………16  DEPARTURE…….-21
TOTAL HEATING UNITS FOR THE SEASON…………5537  DEPARTURE……-535
TOTAL HEATING UNITS LAST SEASON TO DATE…….5951  DEPARTURE……-414

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

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..35 SSW AT  7:34 A.M.
AERO…………………….35 SSW AT  7:34 A.M.
ASOS…………………….35 SSW AT  7:34 A.M.
DAVIS……………………36 SSW AT  7:28 A.M. RMY 36
FASTEST MILE FOR YESTERDAY………………….23 SSW AT  9:26 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….23 S   AT  9:25 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………22 SSW AT  7:28 A.M.
AVERAGE WIND SPEED AND DIRECTION…………….11.4 SSW
ASOS…………………….11.4
DAVIS……………………11.4 SW [228 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…TRACE  DEPARTURE……-0.12
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.94  DEPARTURE……+0.58
ASOS…………..0.96
TOTAL PRECIPITATION FOR THE YEAR……….17.97  DEPARTURE……-0.94
ASOS………….18.60

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…………..31.9  DEPARTURE……-30.8

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  42/28/35/-6/0.00/0.0/008/01         28 NE  AERO 28 NE  RMY 30
04/02  46/35/41/0/…/0.0/000/00           39 NW  AER0 40 NW  RMY 41
04/03  42/38/40/-2/…./0.0/000/00         48 NE  AERO 53 NE  RMY 49
04/04  46/36/41/-1/…./0.0/278/36         38 NE  AERO 38 NE  RMY N/A
04/05  55/36/46/+3/T/0.0/039/05            22 S   AERO 21 S   RMY 21
04/06  61/40/51/+8/0.00/0.0/732/94         29 NW  AERO 30 NW  RMY 29
04/07  63/42/53/+10/0.00/0.0/649/83        29 W   AERO 30 W   RMY 28
04/08  50/41/46/+2/…./…/047/06         23 S   AERO 22 S   RMY 22
04/09  47/37/42/-2/…./…/000/00         58 W   AERO 58 W   RMY 56
04/10  47/35/41/-4/0.02/T/324/41           48 W   AERO 50 W   RMY 53
04/11  51/33/42/-3/0.00/0.0/730/92         38 WNW AERO 39 WNW RMY 40
04/12  60/33/47/+2/0.00/0.0/326/41         38 S   AERO 40 S   RMY N/A
04/13  59/50/55/+9/1.42/0.0/000/00         79 S   AERO 83 S   RMY 78
04/14  57/41/49/+3/0.00/0.0/641/80         41 W   AERO 40 W   RMY N/A
04/15  52/36/44/-3/0.02/0.0/450/56         37 W   AERO 36 W   RMY 37
04/16  47/32/40/-7/T/T/379/47              33 WNW AERO 33 WNW RMY 32
04/17  49/29/39/-8/…./0.0/591/73         41 W   AERO 39 W   RMY 41
04/18  37/31/34/-14/…./4.3/000/00        29 NE  AERO 25 NE  RMY 25
04/19  60/31/46/-2/0.00/0.0/693/85         40 SSW AERO 40 SSW RMY 41
04/20  49/37/43/-6/0.00/0.0/…/..         25 ENE AERO 22 W   RMY N/A
04/21  53/33/43/-6/…./…/…/..         52 S   AERO 52 S   RMY 52
04/22  43/30/37/-12/0.00/0.0/…/..        51 W   AERO 50 W   RMY 50
04/23  55/29/42/-8/0.00/0.0/…/..         31 W   AERO 29 W   RMY N/A
04/24  42/37/40/-10/…./…/…/..        31 NNE AERO 29 NNE RMY 29
04/25  60/38/49/-1/0.00/0.0/…/..         25 S   AERO 24 S   RMY 24
04/26  51/38/45/-6/…./0.0/…/..         51 NE  AERO 50 NE  RMY 50
04/27  39/35/37/-14/…./T/…/..          54 NE  AERO 52 NNE RMY 55
04/28  48/35/42/-10/…./…/…/..        28 N   AERO 27 N   RMY N/A
04/29  55/35/45/-7/0.00/0.0/…/..         24 ENE AERO 23 ENE RMY 22
04/30  52/42/47/-5/…/0.0/…/..          36 SE  AERO 32 SE  RMY N/A

DAILY RECORDS FOR APRIL 2020

4/13/2020
NEW PEAK GUST OF 79 MPH S, REPLACING THE OLD
RECORD OF 59 MPH SSW IN 1995

4/18/2020
NEW RECORD SNOWFALL OF 4.3 INS, REPLACING THE OLD
RECORD OF 3.7 INS IN 1965

4/27/2020
NEW RECORD LOW MAX TEMPERATURE OF 39F, REPLACING
THE OLD RECORD OF 40F IN 1917

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  64/52/58/+5/…./0.0/…/..         46 SSE  AERO 44 SSE RMY N/A
05/02  70/42/56/+3/…./0.0/…/..         41 NW   AERO 40 NW  RMY N/A
05/03  78/55/67/+14/0.00/0.0/…/..        35 SSW  AERO 35 SSW RMY 36

05/04 The low since midnight is 56F, 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 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966

RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976

TODAY’S REPORT PREPARED BY: Matt Douglas