Tuesday, May 19, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 19, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

MUCH NEEDED RAIN ENTERS THE REGION, 0.36 INCHES BY
1:00 PM EST THIS AFTERNOON

A northeasterly flow yesterday was responsible for our
first cooler than normal day since May 2nd. A maximum
of 62F was reached just after the 1:00 PM EST observation,
with temperatures cooling to 50F overnight.

Humidity was on the rise throughout the overnight hours, with
fog and light showers beginning to pass through the region
by this morning’s 7:00 AM EST observation. 0.01 inches of
new rain was recorded by the first observation of the day,
followed by another 0.02 inches by the 10:00 AM EST observation,
with 0.36 inches total by the 1:00 PM EST observation.

Showers were beginning to leave the area following a couple
hours of moderate to occasionally heavy rainfall. A maximum
of just 59F had been reached.
Today’s Observations:

7 A.M.
Weather: Fog
Temperature: 53F; Dew Point: 52F; Wind: SSW at 9 kts
Sea-level pressure: 29.98 ins. Hg, falling, then more quickly
Visibility: 3/4 miles, fog
6-hr Max temp: 53F
6-hr Min temp: 50F
24-hr precip: 0.01 inches
BHO SA 1155 W3 X 3/4F 153/53/52/2109/998/
8//// 58010 ASOS 60001 70001 MANUAL 70001 10053 20050

10 A.M.
Weather: Light rain, fog
Temperature: 57F; Dew Point: 56F; Wind: SSW at 13 kts
Sea-level pressure: 29.95 ins. Hg, falling, then more slowly
Visibility: 5/16 of a mile, except 1/2 of a mile ESE-SSW,
obscured by light rain and fog
3-hr precip: 0.02 inches
BHO SA 1455 W3 X 5/16R-F 141/57/56/2013/995/
VSBY ESE-SSW 1/2 MI/ 8//// 56012 ASOS 60002 MANUAL 60002

1 P.M.
Weather: Light rain, fog
Temperature: 59F; Dew Point: 58F; Wind: S at 13 kts
Sea-level pressure: 29.89 ins. Hg, falling then falling more quickly
Visibility: 1/2 of a mile, light rain and fog
6-Hr Max temp: 59F
6-Hr Min temp: 52F
6-Hr Precip: 0.35 inches
BHO SA 1755 W4 X 1/2R-F 122/59/58/1913/989/ PRCP VRY LGT/
8//// 58019 ASOS 60036 MANUAL 60035 10059 20052
SUMMARY FOR MONDAY, MAY 18, 2015

TEMPERATURE (DEGREES F)
MAX…..62   NORMAL…..67
MIN…..48   NORMAL…..48
MEAN….55   NORMAL…..58

DEPARTURE FROM 30-YEAR NORMAL……………………-3
TOTAL DEPARTURE FOR THE MONTH………………….+105 [+5.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..10  DEPARTURE………..+2
TOTAL HEATING UNITS FOR THE MONTH…………..86  DEPARTURE……….-99
TOTAL HEATING UNITS FOR THE SEASON………..6357  DEPARTURE………+137
TOTAL HEATING UNITS LAST SEASON TO DATE……6289  DIFFERENCE………+68

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0   DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….16   DEPARTURE……….+9
TOTAL COOLING UNITS FOR THE SEASON…………16   DEPARTURE……….+7
TOTAL COOLING UNITS LAST SEASON TO DATE…….13   DIFFERENCE………+3

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………25 NE  AT   1:53 A.M.*
ASOS…………………..27 NE  AT   1:42 A.M.
DAVIS………………….24 NE  AT  12:34 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………..17 NE  AT   1:37 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..18 NE  AT   1:35 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….17 NE  AT   1:35 A.M.
AVERAGE WIND SPEED AND DIRECTION………….10.0 NE
ASOS………………….10.2
DAVIS…………………9.0 ENE [069 deg.] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.01  DEPARTURE…..-0.12
ASOS……………0.01
TOTAL PRECIPITATION FOR THE MONTH………..0.28  DEPARTURE…..-1.93
ASOS……………0.27
TOTAL PRECIPITATION FOR THE YEAR………..18.20  DEPARTURE…..-2.43
ASOS…………….N/A ***
*** ASOS annual totals not available due to erroneous readings

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…………..150.8  DEPARTURE….+88.1

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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

5/1  52/37/45/-8/0.00/0.0/354/42               21 NE  RMY 20
5/2  63/35/49/-4/0.00/0.0/668/79               20 S   RMY 20
5/3  74/44/59/+6/0.00/0.0/509/60               22 S   RMY 22
5/4  83/47/65/+11/0.00/0.0/783/92              39 SSW RMY 45
5/5  77/56/67/+13/0.03/0.0/222/26              29 SW  RMY N/A
5/6  74/54/64/+10/0.00/0.0/574/67              24 SSW RMY 25
5/7  84/52/68/+13/0.00/0.0/824/96              29 S   RMY 32
5/8  74/44/59/+4/0.00/0.0/809/94               27 NNE RMY 26
5/9  77/44/61/+6/0.00/0.0/509/59               30 S   RMY 32
5/10 88/60/74/+19/0.00/0.0/692/80              28 SSW RMY 30
5/11 84/48/66/+10/0.00/0.0/529/61              30 NE  RMY 31
5/12 84/47/66/+10/0.24/0.0/287/33              33 WNW RMY 37
5/13 67/47/57/+1/0.00/0.0/820/94               31 WNW RMY N/A
5/14 70/44/57/+0/0.00/0.0/…/..               22 NW  RMY 22
5/15 73/51/62/+5/0.00/0.0/…/..               20 WSW RMY 21
5/16 68/53/61/+4/T/0.0/…/..                  23 S   RMY 24
5/17 79/50/65/+8/T/0.0/…/..                  21 NE  RMY N/A
5/18 62/48/55/-3/…./0.0/…/..               25 NE  RMY N/A

5/19 low since midnight is 50F; normal low is now 49F

DAILY RECORDS FOR MAY 2015

NONE SO FAR.

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

TODAY’S REPORT PREPARED BY: Brian Fitzgerald