Friday, May 11, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 11, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

SEASONABLE TEMPERATURES RETURN FOR ANOTHER PLEASANT
DAY ON TOP OF GREAT BLUE HILL…

Yesterday began foggy but ended very pleasant with dry
air and a high of 73F, which is 9 degrees above the daily
normal of 64. So far today we reached a more seasonable
max of 66F, which is 1 degree above the daily normal of
65F. Wind picked up throughout the day and was mostly
from the WNW. The dry air today allowed for visibility to
increase from 45 miles to 80 miles by 10:00 a.m.

Today’s Observations:

7 A.M.
Weather: Scattered cumulus, broken cirrostratus
Temperature: 61F; Dew Point: 45F; Wind: WNW at 9G20 kts
Sea-level pressure: 29.89 ins. Hg, falling, then more slowly
Visibility: 45 miles
6-hr Max temp: 61F
6-hr Min temp: 55F
24-hr precip:  0.00 ins.
BHO SA 1155 45 SCT E250 BKN 45 122/61/45/3009G20/989/ 8/806
51022 10061 20055

10 A.M.
Weather: Scattered cumulus, broken altocumulus, broken
cirrostratus
Temperature: 62F; Dew Point: 36F; Wind: WSW at 13G23 kts
Sea-level pressure: 29.96 ins. Hg, rising, then more rapidly
Visibility: 80 miles
3-hr precip: 0.00 ins.
BHO SA 1455 45 SCT E180 BKN 250 BKN 80 147/62/36/2413G23/996/
8/866 51025

1 P.M.
Weather: Scattered cirrostratus, few cumulus distant SE-NNW
and NNW-NE
Temperature: 66F; Dew Point: 28F; Wind: WNW at 8 kts
Sea-level pressure: 29.99 ins. Hg, rising, then more slowly
Visibility: 80 miles
6-hr Max temp: 66F
6-hr Min temp: 60F
6-hr precip:   0.00 ins.
BHO SA 1755 SCT 250 80 156/66/28/2908/999/ FEW CU
DSNT SE-SSW AND NNW-NE/ 8/106 51009 10066 20060

SUMMARY FOR THURSDAY, MAY 10, 2018

TEMPERATURE (DEGREES F)
MAX…..73   NORMAL…..64
MIN…..48   NORMAL…..46
MEAN….61   NORMAL…..55

DEPARTURE FROM 30-YEAR NORMAL……………………..+6
TOTAL DEPARTURE FOR THE MONTH…………………….+97 [+9.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..4   DEPARTURE……….-6
TOTAL HEATING UNITS FOR THE MONTH………….44   DEPARTURE………-69
TOTAL HEATING UNITS FOR THE SEASON……….5737   DEPARTURE……..-411
TOTAL HEATING UNITS LAST SEASON TO DATE…..5474   DIFFERENCE…….+263

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH…………..32   DEPARTURE………+29
TOTAL COOLING UNITS FOR THE SEASON………….32   DEPARTURE………+27
TOTAL COOLING UNITS LAST SEASON TO DATE……..20   DEPARTURE………+12

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….33 S AT 4:15 P.M.
AERO……………………30 S AT 3:52 P.M.
ASOS……………………33 S AT 4:16 P.M.
DAVIS…………………..33 M AT 4:13 P.M.** RMY 32
FASTEST MILE FOR YESTERDAY…………………24 S AT 4:51 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………23 S AT 7:17 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..24 M AT 4:39 P.M.**
AVERAGE WIND SPEED AND DIRECTION………….10.1 SSW
ASOS………………….10.3
DAVIS…………………10.0 M**
** Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.12
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.42  DEPARTURE……-0.80
ASOS…………..0.39
TOTAL PRECIPITATION FOR THE YEAR……….25.73  DEPARTURE……+6.14
ASOS………….27.31

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…………..92.8  DEPARTURE…….+30.0

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

5/01 65/39/52/-1/0.00/0.0/…/..    25 WNW AERO 21 WNW RMY 25
5/02 88/59/74/+21/0.00/0.0/…/..   37 WSW AERO 29 WSW RMY 35
5/03 90/67/70/+26/…./0.0/…/..   36 SW  AERO 32 WSW RMY 36
5/04 84/67/74/+20/…./0.0/…/..   39 SSW AERO 37 SSW RMY N/A
5/05 73/54/64/+10/0.00/0.0/…/..   56 W   AERO 55 W   RMY N/A
5/06 65/48/57/+3/0.21/0.0/…/..    24 NE  AERO 18 NE  RMY 21
5/07 62/49/56/+1/0.00/0.0/…/..    26 ENE AERO 22 NE  RMY 24
5/08 73/46/60/+5/0.00/0.0/…/..    25 SSE AERO 21 ESE RMY 23
5/09 74/48/61/+6/…./0.0/…/..    23 ESE AERO 18 ESE RMY 21
5/10 73/48/61/+6/…./0.0/…/..    33 S   AERO 30 S   RMY 32

5/11 Low temp since midnight is 55F; normal low is now 46F

DAILY RECORDS FOR MAY 2018

5/03/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 66F SET IN 2001

5/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 66F SET IN 2001

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

RECORDS FOR MAY 11
HIGH 90F IN 1993
LOW 28F IN 1900
PRE 1.28 INS IN 1957
SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD)
PEAK GUST 75e MPH NW IN 1945

RECORDS FOR MAY 12
HIGH 88F IN 2001
LOW 29F IN 1907
PRECIP 1.49 INCHES IN 1968
PEAK GUST 76 MPH S IN 1974

TODAY’S REPORT PREPARED BY: K. Geagan