Sunday, May 31, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 31, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

MONTH OF MAY COMES TO A CLOSE, SUBSTANTIAL RAIN
LOOKS TO PUT A DENT IN MODERATE DROUGHT

A brief early morning rain shower brought 0.03 inches of rain
right around the 3:00 AM EST mark, adding to what has been
an extremely dry month. Substantial rain showers and possible
thunderstorms have entered the region this morning with shower
activity beginning at the station once more by 9:35 AM EST.

By the 1:00 PM EST observation showers over varying intensity
were currently moving through the region, with heavy showers
and thunderstorms north of the city. Visibility was reduced to
25 miles or less in all directions thanks to thin fog and
showers.

Although precipitation through the 1:00 PM EST observation
had brought the monthly total to just 0.66 inches for the month
of May, currently making this the third driest May on record.
Rain, which may fall heavily at times tonight before midnight
may well drop this month of further down the list.

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: Scattered altocumulus, broken altocumulus,
few moderate cumulus distant WSW-WNW
Temperature: 68F; Dew Point: 61F; Wind: SSW at 14 kts,
Sea-level pressure: 30.05 ins. Hg, about the same as 3 hrs ago
Visibility: 25 miles, thin fog in all directions
6-hr Max temp: 68F
6-hr Min temp: 64F
24-hr precip: 0.03 inches
BHO SA 1155 90 SCT E120 BKN 25 177/68/61/2114/005/
FEW MDT CU DSNT WSW-WNW THN FG ALQDS/
8/29/ 53001 ASOS 60003 70003 MANUAL 70003 10068 20064

10 A.M.
Weather: Light rain shower, beginning 9:35 AM EST,
scattered altocumulus, broken cirrostratus, few cumulus
fractus in all directions
Temperature: 73F; Dew Point: 67F; Wind: SW at 9 kts
Sea-level pressure: 30.06 ins. Hg, rising slightly
Visibility: 20 miles, except 15 miles W-NW, 12 miles NNW-NNE,
obscured by rain showers
3-hr precip: Trace
BHO SA 1455 110 SCT E140 BKN 20RW- 179/73/67/2209/006/
RW-B35 VSBY W-NW 15 MI NNW-NNE 12 MI FEW CUFRA ALQDS
PRCP VRY LGT/ 8/796 51002 MANUAL 6000/

1 P.M.
Weather: Broken stratocumulus, broken altocumulus,
overcast altostratus, showers distant N-E, few stratus
fractus in all directions
Temperature: 73F; Dew Point: 67F;  Wind: SW at 7 kts
Sea-level pressure 30.09 ins. Hg, steady, then rising
Visibility: 25 miles, except 20 miles N-NNE
6-hr Max temp: 78F
6-hr Min temp: 68F
3-hr precip: Trace
6-hr precip: Trace
BHO SA 1755 E31 BKN 110 BKN 140 OVC 25 188/73/67/2407/009/
VSBY N-NNE 20 MI SHWRS DSNT N-E FEW STFRA ALQDS THN FG ALQDS/
8/52/ 53009 MANUAL 6000/ 10078 20068

SUMMARY FOR SATURDAY, MAY 30, 2015

TEMPERATURE (DEGREES F)
MAX…..85   NORMAL…..70
MIN…..55   NORMAL…..52
MEAN….70   NORMAL…..61

DEPARTURE FROM 30-YEAR NORMAL……………………+9
TOTAL DEPARTURE FOR THE MONTH………………….+159 [+5.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0  DEPARTURE………..-5
TOTAL HEATING UNITS FOR THE MONTH………….130  DEPARTURE………-133
TOTAL HEATING UNITS FOR THE SEASON………..6401  DEPARTURE………+103
TOTAL HEATING UNITS LAST SEASON TO DATE……6384  DIFFERENCE………+17

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..5   DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE MONTH………….49   DEPARTURE………+28
TOTAL COOLING UNITS FOR THE SEASON…………49   DEPARTURE………+26
TOTAL COOLING UNITS LAST SEASON TO DATE…….13   DIFFERENCE……..+36

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………37  SSW  AT  6:29 P.M.
ASOS…………………..42  SSW  AT  6:29 P.M.
DAVIS………………….40  SSW  AT  6:29 P.M. RMY 42
FASTEST MILE FOR YESTERDAY………………..30  SSW  AT  4:44 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..30  SSW  AT  4:45 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….30  SSW  AT  4:45 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..17.3 SSW
ASOS…………………..16.6
DAVIS………………….15.7 SSW [207 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.03  DEPARTURE…..-0.13
ASOS……………0.03
TOTAL PRECIPITATION FOR THE MONTH………..0.66  DEPARTURE…..-3.30
ASOS……………0.66
TOTAL PRECIPITATION FOR THE YEAR………..18.58  DEPARTURE…..-3.80
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 77/58/68/+7/0.00/0.0/…/..               18 ENE RMY 19
5/30 85/55/70/+9/0.00/0.0/…/..               37 SSW RMY 42

5/31 low since midnight is 64F; 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 31
HIGH 92F IN 1944,1987
LOW 35F IN 1961
PRECIP 5.02 INS 1984 (RECORD FOR MAY)
PEAK GUST 54e MPH WNW IN 1945

RECORDS FOR JUNE 1
HIGH 90F IN 1937,2013
LOW 36F IN 1945 [Record for month] PRECIP 2.28 INS IN 1992
PEAK GUST 51e MPH SE IN 1952

TODAY’S REPORT PREPARED BY: Brian Fitzgerald