Thursday, May 21, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 21, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

MOSTLY CLOUDY AND VERY DRY WITH SEASONABLE TEMPERATURES

A colder than usual start to this morning has given way
to normal temperatures this afternoon as breaks in the
clouds allowed for some morning sun.  While temperatures
may have gone up, the air remains very dry and dew points
have decreased to near 30.  This has dropped the humidity
down to 31%.

As of the 1 o’clock observation, clouds had begun to thicken
with a few lower cumulus beginning to appear on the horizon.
The high temperature so far is 66 degrees and conditions remain
very dry with humidity in the upper 20’s with increasing winds.

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus, broken altocumulus
Temperature: 48F; Dew Point: 38F; Wind: W at 8 kts
Sea-level pressure: 30.13 ins. Hg, rising then more slowly
Visibility: 65 miles, light distant haze
6-hr Max temp: 66F
6-hr Min temp: 43F
24-hr precip: 0.00 inches
BHO SA 1155 100 SCT E160 BKN 65 205/48/38/2808/013/ LGT DSNT HZ
THN K LYR ALG HRZN NNW-NE/ 8/050 51011 10066 20043

10 A.M.
Weather: Broken Altocumulus
Temperature: 61F; Dew Point: 31F; Wind: S at 8 kts
Sea-level pressure: 30.11 ins. Hg, steady then decreasing
Visibility: 70 miles, light distant haze
BHO SA 1455 E130 BKN 70 198/61/31/1908/011/ LGT DSNT HZ INCR
VSBY ALQDS/ 8//9/ 58007

1 P.M.
Weather: Broken Altocumulus, Few Cumulus WNW-NW Few Altocumulus
Lenticularis
Temperature: 64F; Dew Point: 30F; Wind: SSW at 12 kts
Sea-level pressure: 30.07 ins. Hg, Steady then decreasing
Visibility: 65 miles, light distant haze
6-Hr Max temp: 66F
6-Hr Min temp: 48F
BHO SA 1755 E110 BKN 65 184/64/30/2012/007/ ACLS N FEW CU WNW-NW
LGT DSNT HZ ALQDS/ 8/050 58014 10066 20048

SUMMARY FOR WEDNESDAY, MAY 20, 2015

TEMPERATURE (DEGREES F)
MAX…..66   NORMAL…..68
MIN…..46   NORMAL…..49
MEAN….56   NORMAL…..59

DEPARTURE FROM 30-YEAR NORMAL……………………-3
TOTAL DEPARTURE FOR THE MONTH………………….+101 [+5.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………9  DEPARTURE………..+2
TOTAL HEATING UNITS FOR THE MONTH………….103  DEPARTURE……….-97
TOTAL HEATING UNITS FOR THE SEASON………..6374  DEPARTURE………+139
TOTAL HEATING UNITS LAST SEASON TO DATE……6303  DIFFERENCE………+71

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0   DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….16   DEPARTURE……….+7
TOTAL COOLING UNITS FOR THE SEASON…………16   DEPARTURE……….+5
TOTAL COOLING UNITS LAST SEASON TO DATE…….13   DIFFERENCE………+3

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………32 WNW   AT  12:41 P.M.
ASOS…………………..37 WNW   AT  12:41 P.M.
DAVIS………………….35 W     AT  12:41 P.M. RMY 37
FASTEST MILE FOR YESTERDAY………………..18 W     AT   4:03 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..25 NW    AT   4:02 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….23 NW    AT   4:02 P.M.
AVERAGE WIND SPEED AND DIRECTION………….15.1 WNW
ASOS………………….14.5
DAVIS…………………12.9 WNW [296 deg.] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.13
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.63  DEPARTURE…..-1.85
ASOS……………0.63
TOTAL PRECIPITATION FOR THE YEAR………..18.55  DEPARTURE…..-2.35
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 63/50/57/-1/0.36/0.0/…/..               24 S   RMY 26
5/20 66/46/56/-3/0.00/0.0/…/..               32 WNW RMY 37

5/21 low since midnight is 43F; 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 21
HIGH 92F IN 1921
LOW 35F IN 1907
PRECIP 1.61 INS IN 1954
PEAK GUST 74 MPH WSW IN 2006

RECORDS FOR MAY 22
HIGH 93F IN 1911
LOW 35F IN 1907
PRECIP 3.75 INCHES IN 1920
PEAK GUST 49e MPH SSW IN 1947

TODAY’S REPORT PREPARED BY: Robert Millette