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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 19, 2020
ALL TIMES ARE IN EASTERN STANDARD TIME

SUNNY BUT COOL WITH AN ONSHORE BREEZE....

It's been another quiet day today under mainly sunny skies.
A stiff northeast to east-northeast wind has keep 
temperatures on the cooler side however. Temperatures have
only risen to the mid 50s through early this afternoon.
Gusts this morning were occasionally exceeding 30 mph, but
have since diminished early this afternoon with gusts 
generally in the 20-25 mph range.

Visibility has been limited to only 40-50 miles due to a 
"haze", which actually consists of pollen rather than the
normal pollution.

The high so far today is 56F, this is 11 degrees below the 
daily normal high of 67F. The low since midnight is 45F,
which is 4 degrees below the daily normal low of 49F.


Today's Observations:

7 A.M.
Weather: Thin scattered cirrus, few stratocumulus distant N
and NE-E
Temperature: 50F; Dew Point: 41F; Relative Humidity: 70%
Wind: NE at 17G27 kts, peak wind ENE 29 kts at 6:25am   
Sea-level pressure: 30.30 ins. Hg: steady, then rising
Visibility: 40 miles, hazy
6-hr Max temp: 50F
6-hr Min temp: 45F
24-hr Precip: Trace
24-hr Snowfall: 0.0 ins.
BHO SA 1155 250 –SCT 40 260/50/41/0517G27/030/ FEW SC DSNT N
AND NE-E HAZY PK WND 0629/25/ 8/501 53020 70000 10050 20045

10 A.M.
Weather: Thin broken cirrus, few stratocumulus all quadrants
Temperature: 53F; Dew Point: 41F; Relative Humidity: 63%
Wind: NE at 10G22 kts
Sea-level pressure: 30.37 ins. Hg: rising, then more slowly
Visibility: 50 miles, hazy
3-hr Precip:  0.00 ins.
3-hr Snowfall: 0.0 ins.
BHO SA 1455 E250 –BKN 50 285/53/41/0510G22/037/ FEW SC ALQDS HAZY/
8/501 51025

1 P.M.
Weather: Thin broken cirrus, few cumulus S-W-N
Temperature: 55F; Dew Point: 42F; Relative Humidity: 61%
Wind: ENE at 12G21 kts
Sea-level pressure: 30.38 ins. Hg: rising then falling
Visibility: 50 miles, hazy
6-hr Max temp: 56F
6-hr Min temp: 49F
6-hr Precip:  0.00 ins.
6-hr Snowfall: 0.0 ins.
BHO SA 1755 E250 –BKN 50 289/55/42/0612G21/038/ FEW CU S-W-N
HAZY/ 8/201 50004 10056 20049


SUMMARY FOR MONDAY, MAY 18, 2020 

TEMPERATURE (DEGREES F)
MAX.....60   NORMAL.....67
MIN.....47   NORMAL.....48
MEAN....54   NORMAL.....58

DEPARTURE FROM 30-YEAR NORMAL...................-4
TOTAL DEPARTURE FOR THE MONTH..................-41 [-2.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY...............11  DEPARTURE........+3
TOTAL HEATING UNITS FOR THE MONTH..............218  DEPARTURE.......+33
TOTAL HEATING UNITS FOR THE SEASON............5739  DEPARTURE......-481
TOTAL HEATING UNITS LAST SEASON TO DATE.......6144  DEPARTURE......-405

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY................0  DEPARTURE........-1
TOTAL COOLING UNITS FOR THE MONTH................2  DEPARTURE........-5
TOTAL COOLING UNITS FOR THE SEASON...............2  DEPARTURE........-7
TOTAL COOLING UNITS LAST SEASON TO DATE..........0  DEPARTURE........+2

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY....................24 W   AT  3:48 A.M.  
                   AERO........................E22 ENE AT 11:18 P.M.  
                   ASOS.........................22 ENE AT 11:35 P.M. 
                   DAVIS........................24 W   AT  3:49 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY......................17 E   AT  9:58 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE...................16 ENE AT 11:45 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE..................17 E   AT  9:37 P.M.
AVERAGE WIND SPEED AND DIRECTION................ 9.7 ENE               
                   ASOS.........................10.0
                   DAVIS........................10.1 ENE [075 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M...Trace  DEPARTURE......-0.14
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........2.55  DEPARTURE......+0.33
                         ASOS..............2.54
TOTAL PRECIPITATION FOR THE YEAR..........19.59  DEPARTURE......-1.18
                         ASOS.............20.04

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........0.0
TOTAL SNOWFALL FOR THE MONTH..............Trace  DEPARTURE........0.0
TOTAL SNOWFALL FOR THE SEASON..............31.9  DEPARTURE......-30.8


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/..../0.0/000/00         46 SSE  AERO 44 SSE RMY N/A 
05/02  70/42/56/+3/..../0.0/729/86         41 NW   AERO 40 NW  RMY N/A
05/03  78/55/67/+14/0.00/0.0/613/72        35 SSW  AERO 35 SSW RMY 36
05/04  72/45/59/+5/T/0.0/247/29            37 NW   AERO 40 WNW RMY 39  
05/05  60/40/50/-4/0.00/0.0/821/96         31 NW   AERO 32 NW  RMY N/A
05/06  57/38/48/-6/T/0.0/498/58            24 ESE  AERO 22 ENE RMY 22
05/07  63/37/50/-5/0.00/0.0/576/67         30 WSW  AERO 29 WSW RMY N/A
05/08  57/40/49/-6/..../0.0/328/38         31 W    AERO 32 W   RMY N/A
05/09  44/32/38/-17/..../T/484/56          52 W    AERO 53 W   RMY 54
05/10  59/31/45/-10/0.00/0.0/763/88        46 W    AERO 46 W   RMY 49
05/11  65/43/54/-2/0.22/0.0/.../..         39 S    AERO 43 S   RMY 41
05/12  55/37/46/-10/0.00/0.0/.../..        37 W    AERO 37 W   RMY 37
05/13  59/32/46/-10/0.00/0.0/.../..        37 WNW  AERO 37 WNW RMY 38
05/14  70/40/55/-2/0.00/0.0/.../..         29 W    AERO 26 W   RMY 27
05/15  78/50/64/+7/..../0.0/.../..         40 WSW  AERO 40 WSW RMY 43
05/16  69/47/58/+1/..../0.0/.../..         31 NW   AERO 31 NW  RMY 32
05/17  67/47/57/0/0.00/0.0/.../..          22 SSW  AERO N/A    RMY 21
05/18  60/47/54/-4/T/0.0/.../..            24 W    AERO 22 ENE RMY N/A

05/19 The low since midnight is 45F, the daily normal low is 49F
 
DAILY RECORDS FOR MAY 2020

5/13/2020: NEW RECORD LOW OF 32F, REPLACING 35F SET IN 
1914 AND 2005


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

RECORDS FOR MAY 19
HIGH 91F IN 1962
LOW 34F IN 2002
PRECIP 1.54 INCHES IN 1900
PEAK GUST 58 MPH NW IN 1964

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: Matt Douglas