Monday, May 20, 2019

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 20, 2019
ALL TIMES ARE IN EASTERN STANDARD TIME

EARLY MORNING THUNDERSTORMS LEADING TO WARMER TEMPERATURES
AND CLEARING SKIES….

At the 7 A.M. observation there was 0.01 inches of rain from a passing
overnight thunderstorm. Overcast skies in the morning clearing up in
the afternoon helping temperatures warm up into the lower 80s. Hazy
conditions limited visibility to 35 miles for a considerable part of
the day. The high so far today is 83F, 15 degrees above the normal
maximum of 68F. The low since midnight is 60F,12 degree above the
normal daily minimum of 48F.

Today’s Observations:

7 A.M.
Weather: Overcast stratus
Temperature: 63F; Dew Point: 62F; Wind: SSW at 12 kts,
Sea-level pressure: 29.81 ins. Hg, falling then rising
Visibility: 10 miles, distant haze
6-hr Max temp: 63F
6-hr Min temp: 60F
24-hr Precip: 0.14 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 0 ins.
BHO SA 1155 09 OVC 10 098/63/62/2012/981/ DSNT HZ ALQDS/
8/6// 53001 70014 10063 20060

10 A.M.
Weather: Overcast stratocumulus
Temperature: 75F; Dew Point: 66F; Wind: WSW at 12 kts,
Sea-level pressure: 29.79 ins. Hg, falling then more rapidly
Visibility: 30 miles, distant haze
3-hr Precip: 0.00 ins.
BHO SA 1455 30 BKN 35 089/75/66/2412/979/ DSNT HZ ALQDS/
8/500 58009

1 P.M.
Weather: scattered cumulus and stratocumulus
Temperature: 82F; Dew Point: 63F; Wind: WSW at 14G24 kts
Sea-level pressure: 29.72 ins. Hg, falling then more rapidly
Visibility: 35 miles, distant haze
6-hr Max temp: 83F
6-hr Min temp: 61F
6-hr Precip: 0.13 ins.
BHO SA 1755 34 SCT 35 067/82/63/2514G24/972/ DSNT HZ ALQDS/
8/800 58022 10083 20061

SUMMARY FOR SUNDAY, MAY 19, 2019

TEMPERATURE (DEGREES F)
MAX…..69   NORMAL…..68
MIN…..50   NORMAL…..49
MEAN….60   NORMAL…..58

DEPARTURE FROM 30-YEAR NORMAL……………………+2
TOTAL DEPARTURE FOR THE MONTH…………………..-67 [-3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………5   DEPARTURE………-1
TOTAL HEATING UNITS FOR THE MONTH………….249   DEPARTURE……..+56
TOTAL HEATING UNITS FOR THE SEASON………..6150   DEPARTURE……..-78
TOTAL HEATING UNITS LAST SEASON TO DATE……5817   DIFFERENCE……+333

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………..39 S   AT 1:16 P.M.
AERO…………………….43 SSE AT 5:02 P.M.
ASOS…………………….43 SSW AT 5:06 P.M.
DAVIS……………………46 S   AT 1:16 P.M.  RMY 42
FASTEST MILE FOR YESTERDAY………………….34 SSE AT 5:06 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………….31 SSW AT 5:07 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………………34 S   AT 5:07 P.M.
AVERAGE WIND SPEED AND DIRECTION……………18.9 S
ASOS……………………18.7
DAVIS…………………..19.1 S [176 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.14  DEPARTURE…….-0.14
ASOS…………..0.15
TOTAL PRECIPITATION FOR THE MONTH……….2.65  DEPARTURE…….+0.30
ASOS…………..2.59
TOTAL PRECIPITATION FOR THE YEAR……….23.83  DEPARTURE…….+2.93
ASOS………….23.68

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 57/40/49/-4/0.00/0.0/…/..           21 S   AERO 21 SSE  RMY 21
05/02 45/41/43/-10/0.02/0.0/…/..          21 NE  AERO 21 SSW  RMY 20
05/03 60/43/52/-1/…./…/…/..           23 S   AERO 23 S    RMY 22
05/04 54/46/50/-4/…./…/…/..           14 ENE AERO 14 ENE  RMY 17
05/05 52/44/48/-6/0.00/0.0/…/..           18 NE  AERO 20 NE   RMY N/A
05/06 58/44/51/-3/…./0.0/…/..           25 NE  AERO 26 ENE  RMY 24
05/07 72/41/57/+2/0.12/0.0/…/..           30 S   AERO 29 S    RMY 30
05/08 67/48/58/+3/0.00/0.0/…/..           20 NE  AERO 20 NE   RMY 19
05/09 60/43/52/-3/0.00/0.0/…/..           21 SE  AERO 21 E    RMY 22
05/10 61/46/54/-1/0.16/0.0/…/..           35 S   AERO 37 S    RMY 37
05/11 68/50/59/+3/…./…/…/..           26 NW  AERO M  M    RMY N/A
05/12 50/36/43/-13/0.68/T/…/..          30 ENE AERO M  M    RMY N/A
05/13 52/38/45/-11/…./…/…/..          35 E   AERO M  M    RMY 34
05/14 44/38/41/-16/…./…/…/..          26 NNE AERO M  M    RMY 25
05/15 58/40/49/-8/…./…/…/..           28 NW  AERO M  M    RMY 28
05/16 68/46/57/0/…./…/…/..            17 NW  AERO M  M    RMY 19
05/17 64/49/57/0/…./…/…/.. 22 WNW AERO 21 WNW  RMY 25
05/18 72/49/61/+3/…./…/…/..           26 SSE AERO 25 SSE  RMY 29
05/19 69/50/60/+2/…./…/…/..           39 S   AERO 43 SSE  RMY 42

05/20 Low temp since midnight is 50F; normal low is 49F

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

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

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: Nicholas Rousseau