Monday, September 28, 2020

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

MONDAY, SEPTEMBER 28, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

WARM AND HUMID, FIRST MEASURABLE RAINFALL IN 3 WEEKS….

A warm and humid air mass has returned to the region with
dew points in the mid to upper 60s. This moisture ladened
air is responsible for keeping night-time temperatures
well above normal. As a matter of fact, if the temperature
fails to fall below 65F before midnight tonight, we will
establish a new record high minimum for the date today.
The previous record is 65 in 2008. So far the low for today
has been 67 degrees.

The other “big” story today is that we received measurable
rainfall yesterday afternoon in the form of a brief rain
shower which brought 0.01″, and again overnight in the form
of drizzle which deposited another 0.02″. This is the first
measurable rain since 0.01″ was measured on the 11th!

Despite the little bit of rainfall, we are still under the
influence of a severe drought, with some parts of the
region in extreme drought. The rainfall total for the month
is up to 0.54″, but this is still more than 3 inches below
normal. For the year to date, we are 5.29 below normal.

The high so far today is 78F, 11 degrees above the daily
normal max of 67F. The low since midnight is 67F, which
is 17 degrees above the normal low of 50F.

Today’s Observations:

7 A.M.
Weather: Broken stratus fractus, broken cirrostratus,
thin broken cirrus
Temperature: 69F; Dew Point: 67F; Relative Humidity: 94%
Wind: S at 9G14 kts
Sea-level pressure: 29.98 ins. Hg: falling then rising
Visibility: 30 miles, thin fog all quadrants
6-hr Max temp: 69F
6-hr Min temp: 68F
24-hr Precip: 0.03 ins.
BHO SA 1155 E10 BKN 180 BKN 250 -BKN 30 153/69/67/1809G14/998/
THN F ALQDS/ 8/706 53006 6000 70003 10069 20068

10 A.M.
Weather: Scattered cumulus/stratocumulus, scattered altocumulus,
broken cirrostratus, thin broken cirrus
Temperature: 76F; Dew Point: 62F; Relative Humidity: 62%
Wind: SSW at 10 kts
Sea-level pressure: 29.99 ins. Hg: falling then rising
Visibility: 35 miles, hazy
3-hr Precip: 0.00 ins.
BHO SA 1455 20 SCT 130 SCT E180 BKN 250 -BKN 35 155/76/62/2010/999/
SCSL ALQDS HAZY/ 8/838 50002

1 P.M.
Weather: Broken cumulus/stratocumulus, broken altostratus,
broken cirrostratus, broken cirrus, light rain shower
Temperature: 76F; Dew Point: 65F; Relative Humidity: 69%
Wind: S at 8 kts
Sea-level pressure: 29.96 ins. Hg: falling, then more rapidly
Visibility: 40 miles, 6 miles E-SE, 8 miles SSE, 10 miles S-SSW
6-hr Max temp: 78F
6-hr Min temp: 69F
6-hr Precip: TRACE
BHO SA 1755 E30 BKN 65 BKN 180 BKN 250 BKN 40RW- 146/76/65/1708/996/
RWS E-S-SW MVG N VSBY 6 E-SE 8 SSE 10 S-SSW RWB52 PCPN VRY LGT HAZY/
8/736 58009 6000 10078 20069

SUMMARY FOR SUNDAY, SEPTEMBER 27, 2020

TEMPERATURE (DEGREES F)
MAX…..79   NORMAL…..67
MIN…..64   NORMAL…..50
MEAN….72   NORMAL…..59

DEPARTURE FROM 30-YEAR NORMAL…………….+13
TOTAL DEPARTURE FOR THE MONTH……………. +3 [-0.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..0  DEPARTURE……-7
TOTAL HEATING UNITS FOR THE MONTH………….94  DEPARTURE…… 0
TOTAL HEATING UNITS FOR THE SEASON…………97  DEPARTURE…..-12
TOTAL HEATING UNITS LAST SEASON TO DATE…….83  DEPARTURE…..+14

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………. 7  DEPARTURE……+6
TOTAL COOLING UNITS FOR THE MONTH………… 63  DEPARTURE….. +5
TOTAL COOLING UNITS FOR THE SEASON………..820  DEPARTURE….+225
TOTAL COOLING UNITS LAST SEASON TO DATE……678  DEPARTURE….+142

PEAK WIND GUST FOR YESTERDAY (MPH)
420C/Official…………….24 S   AT  4:57 P.M.
AERO…………………….25 S   AT  4:55 P.M.
ASOS…………………….24 S   AT  5:01 P.M.
DAVIS……………………25 S   AT  5:00 P.M.
RMY 24  MERLIN 24
FASTEST MILE FOR YESTERDAY………………….19 S   AT  5:00 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….17 S   AT  5:37 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………16 S   AT  4:59 P.M.
AVERAGE WIND SPEED AND DIRECTION………….. 9.0 S (216 total miles)
ASOS………………….. 8.9
DAVIS…………………. 8.5 S [192 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.03  DEPARTURE….-0.11
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….0.54  DEPARTURE….-3.08
ASOS…………..0.52
TOTAL PRECIPITATION FOR THE YEAR……….33.35  DEPARTURE….-5.29
ASOS………….34.10

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

09/01  76/59/68/0/0.00/698/88              22 SSE  AERO 21 SE   RMY 20
09/02  69/59/64/-4/0.18/102/13             23 SSE  AERO 23 SSE  RMY 24
09/03  75/66/71/+4/0.04/000/00             22 SSW  AERO 21 SSW  RMY N/A
09/04  82/62/72/+5/0.00/763/98             26 WNW  AERO 26 WNW  RMY 25
09/05  76/55/66/-1/0.00/760/98             25 W    AERO 25 W    RMY 24
09/06  78/58/68/+1/0.00/356/46             24 W    AERO 24 W    RMY N/A
09/07  79/61/70/+4/0.00/632/82             27 SSE  AERO 30 SSE  RMY 28
09/08  82/61/72/+6/0.00/545/71             17 S    AERO 16 S    RMY 17
09/09  80/62/71/+5/0.00/214/28             16 S    AERO 15 S    RMY 16
09/10  81/69/75/+10/0.28/015/02            21 SSW  AERO 21 SSW  RMY N/A
09/11  72/55/64/-1/0.01/152/20             25 N    AERO 25 N    RMY N/A
09/12  68/51/60/-5/0.00/666/88             21 ENE  AERO 21 ENE  RMY 21
09/13  74/53/64/0/0.00/611/81              26 SSW  AERO 26 SSW  RMY 26
09/14  74/50/62/-2/0.00/511/68             29 NNW  AERO 33 NNW  RMY 30
09/15  64/44/54/-10/0.00/583/78            18 S    AERO 18 S    RMY N/A
09/16  72/49/61/-2/0.00/603/81             31 SSW  AERO 31 SSW  RMY 31
09/17  76/57/67/+4/0.00/453/61             26 WSW  AERO 28 W    RMY N/A
09/18  64/48/56/-6/0.00/163/22             28 NE   AERO 30 NNW  RMY N/A
09/19  59/42/51/-11/0.00/722/98            23 N    AERO 23 N    RMY N/A
09/20  58/40/49/-13/0.00/602/82            25 NE   AERO 25 NE   RMY 27
09/21  61/41/51/-10/0.00/…/..            29 NE   AERO 27 NE   RMY 29
09/22  63/39/51/-10/0.00/…/..            28 NNW  AERO 30 NNW  RMY 29
09/23  78/50/64/+4/0.00/…/..             31 NW   AERO 32 WNW  RMY 32
09/24  76/57/67/+7/0.00/…/..             20 SW   AERO 18 WSW  RMY 19
09/25  77/57/67/+7/0.00/…/..             18 ENE  AERO 18 WSW  RMY N/A
09/26  77/57/67/+8/0.00/…/..             21 S    AERO 21 S    RMY 21
09/27  79/64/72/+13/0.01/…/..            24 S    AERO 25 S    RMY 24

09/28 The low since midnight is 67F, the daily normal low is 50F

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

RECORDS FOR SEPTEMBER 28
HIGH 86F IN 2014
LOW 33F IN 1897,1947
PRECIP 2.46 INCHES IN 2004
PEAK GUST 69 MPH NE IN 1962

RECORDS FOR SEPTEMBER 29
HIGH 85F IN 1952
LOW 28F IN 1914 (SEPTEMBER MINIMUM RECORD)
PRECIP 2.61 INCHES IN 1907
PEAK GUST 62 MPH S IN 2005

TODAY’S REPORT PREPARED BY: Matt Douglas