Friday, May 29, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 29, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

THURSDAY STORMS MISS BLUE HILL AS DRY SPELL CONTINUES
WARM AND DRY AGAIN TODAY

Thunderstorms, some of them strong to severe, impacted parts of the region
yesterday afternoon and evening.  These showers and storms largely missed the
South Shore, however, including here at Blue Hill where no precipitation was
recorded.  This latest dry day pushes our monthly deficit over three inches,
and May 2015 remains among the driest Mays on record with 0.63 inches. This is also
shaping up to be one of the warmest months of May on record, with temperatures
averaging about five degrees above normal for the month so far.

Today has been less hot and humid than the past few days, but temperatures
remain above average, and the dew point is still holding around 60F.  A light
northeast breeze has replaced the southwesterly winds of recent days, keeping
coastal areas on the cooler side.  We began the day with much improved
visibility over recent days, up to 75 miles at the first observation, but
this number had fallen to 40 miles by the 1:00 P.M. EST observation, with
hazier conditions returning.

BHO Driest Mays, inches (1885-2014)

1) 0.50 in 1944
2) 0.62 in 1964
3) 0.89 in 1911
4) 1.11 in 1899
5) 1.20 in 1959

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant WNW-E
Temperature: 67F; Dew Point: 59F; Wind: Estimated N at 5 kts,
Wind: Light
Sea-level pressure: 30.30 ins. Hg, rising, then more slowly
Visibility: 75 miles
6-hr Max temp: 67F
6-hr Min temp: 58F
24-hr precip: none
BHO SA 1155 CLR 75 260/67/59/E0105/030/ FEW CI DSNT WNW-E WND LGT/
8/001 51017 10067 20058

10 A.M.
Weather: Scattered stratocumulus (2 levels)
Temperature: 73F; Dew Point: 61F; Wind: ENE at 12 kts
Sea-level pressure: 30.31 ins. Hg, rising then falling
Visibility: 55 miles, except 45 miles WSW-NW, distant haze
BHO SA 1455 30 SCT 50 SCT 55 264/73/61/0712/031/ DSNT HZ VSBY WSW-NW 45/
8/500 50004

1 P.M.
Weather: Scattered cumulus, fog bank distant offshore NE-ENE, few cirrus S-NW
Temperature: 74F; Dew Point: 60F;  Wind: ENE at 8 kts
Sea-level pressure 30.30 ins. Hg, falling slightly
Visibility: 40 miles, distant haze
6-hr Max temp: 75F
6-hr Min temp: 67F
BHO SA 1755 35 SCT 40 261/74/60/0608/030/ FOG BANK DSNT OFFSHR NE-ENE
FEW CI S-NW DSNT HZ/ 8/101 58003 10075 20067

SUMMARY FOR THURSDAY, MAY 28, 2015

TEMPERATURE (DEGREES F)
MAX…..83   NORMAL…..70
MIN…..61   NORMAL…..51
MEAN….72   NORMAL…..61

DEPARTURE FROM 30-YEAR NORMAL…………………..+11
TOTAL DEPARTURE FOR THE MONTH………………….+143 [+4.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0  DEPARTURE………..-6
TOTAL HEATING UNITS FOR THE MONTH………….130  DEPARTURE………-122
TOTAL HEATING UNITS FOR THE SEASON………..6401  DEPARTURE………+114
TOTAL HEATING UNITS LAST SEASON TO DATE……6362  DIFFERENCE………+39

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..7   DEPARTURE……….+6
TOTAL COOLING UNITS FOR THE MONTH………….41   DEPARTURE………+23
TOTAL COOLING UNITS FOR THE SEASON…………41   DEPARTURE………+21
TOTAL COOLING UNITS LAST SEASON TO DATE…….28   DIFFERENCE……..+13

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………30  SSW  AT  3:47 P.M.
ASOS…………………..33  SSW  AT  3:28 P.M.
DAVIS………………….33  SSW  AT  3:46 P.M. RMY 34
FASTEST MILE FOR YESTERDAY………………..25  SSW  AT  3:29 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..24  SSW  AT  3:28 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….24  SSW  AT  3:37 P.M.
AVERAGE WIND SPEED AND DIRECTION………….14.3 SSW
ASOS………………….13.6
DAVIS…………………13.3 SSW [208 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.15
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.63  DEPARTURE…..-3.03
ASOS……………0.63
TOTAL PRECIPITATION FOR THE YEAR………..18.55  DEPARTURE…..-3.53
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/+0/0.00/0.0/848/97               22 NW  RMY 22
5/15 73/51/62/+5/0.00/0.0/491/56               20 WSW RMY 21
5/16 68/53/61/+4/T/0.0/053/06                  23 S   RMY 24
5/17 79/50/65/+8/T/0.0/783/89                  21 NE  RMY N/A
5/18 62/48/55/-3/…./0.0/538/61               25 NE  RMY N/A
5/19 63/50/57/-1/0.36/0.0/000/00               24 S   RMY 26
5/20 66/46/56/-2/0.00/0.0/…/..               32 WNW RMY 37
5/21 66/43/55/-4/…./0.0/…/..               24 S   RMY 24
5/22 73/49/61/+2/T/0.0/…/..                  32 NW  RMY 36
5/23 64/40/52/-7/0.00/0.0/…/..               28 WNW RMY 32
5/24 81/50/66/+7/0.00/0.0/…/..               28 SSW RMY 31
5/25 80/56/68/+8/0.00/0.0/…/..               29 SSW RMY 31
5/26 83/61/72/+12/0.00/0.0/…/..              30 SSW RMY N/A
5/27 82/62/72/+12/T/0.0/…/..                 36 SSW RMY 41
5/28 83/61/72/+11/0.00/0.0/…/..              30 SSW RMY 34

5/29 low since midnight is 58F; normal low is now 52F

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 29
HIGH 93F IN 1919
LOW 35F IN 1902
PRECIP 1.63 INS 1990
PEAK GUST 55e MPH NNW IN 1943, WNW IN 1945

RECORDS FOR MAY 30
HIGH 93F IN 1929
LOW 39F IN 1949,1961
PRECIP 1.47 INS 1948
PEAK GUST 61e MPH NW IN 1945

TODAY’S REPORT PREPARED BY: Jonathan O’Brien