Tuesday, July 21, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, JULY 21, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

FIRST 90F DEGREE READING OF THE YEAR REACHED YESTERDAY

Yesterday’s heat and humidity culminated in a maximum
temperature of 90F, lasting nearly three hours from
2:00 to 4:00 PM EST. This is the first 90F degree reading
of the year, and the last first 90F degree later than this was
23 July of 1998.

Temperatures were slow to cool overnight, with temperatures
still at 75F by midnight this morning EST. By this morning’s
7:00 AM EST observation and overnight low of 70F had been recorded.

Mostly cloudy skies have kept temperatures from rising quickly
this morning, and by the 1:00 PM EST observation skies were
beginning to clear. A maximum temperature of 82F had been
recorded by that time, along with visibility of 40 miles in
all directions with hazy conditions.
Today’s Observations:

7 A.M.
Weather: Scattered altocumulus castellanus, scattered
altostratus
Temperature: 72F; Dew Point: 60F; Wind: estimated NW at 4 kts
Wind Speed: Light
Sea-level pressure: 29.68 ins. Hg, rising, then more quickly
Visibility: 60 miles, light distant haze
6-hr Max temp: 73F
6-hr Min temp: 70F
24-hr precip: none
BHO SA 1155 70 SCT E110 BKN 60 050/72/60/E3104/968/
ACC ALQDS LGT DSNT HZ ALQDS WND LGT/ 8/080 53002 10073 20070

10 A.M.
Weather: Broken altocumulus, broken altostratus, overcast cirrus,
few altocumulus castellanus distant NE, thin smoke layer along
horizon in all directions
Temperature: 77F; Dew Point 66F; Wind: estimated NNW at 2 kts
Wind Speed: Light
Sea-level pressure: 29.66 ins. Hg, falling, then rising but lower
Visibility: 50 miles, light distant haze, thin smoke layer along
horizon
BHO SA 1455 E60 BKN 140 BKN 200 OVC 50 045/77/66/E3302/966/
FEW ACC DSNT NE THN K LYR ALNG HRZN ALQDS LGT DSNT HZ ALQDS
WND LGT/ 8/011 55005

1 P.M.
Weather: Scattered altocumulus, broken altostratus,
broken cirrus
Temperature: 82F; Dew Point: 66F; Wind: estimated SW at 3 kts,
Wind Speed: Light
Sea-level pressure: 29.64 ins. Hg, rising, then falling and lower
Visibility: 40 miles, hazy
6-hr Max temp: 82F
6-hr Min temp: 72F
BHO SA 1755 110 SCT E140 BKN 200 BKN 40 036/82/66/E2203/964/
HAZY WND LGT/ 8/071 58009 10082 20072
SUMMARY FOR MONDAY, JULY 20, 2015

TEMPERATURE (DEGREES F)
MAX…..90   NORMAL…..81
MIN…..73   NORMAL…..63
MEAN….82   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL…………………..+10
TOTAL DEPARTURE FOR THE MONTH…………………..+16 [+0.6 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..17   DEPARTURE……….+9
TOTAL COOLING UNITS FOR THE MONTH………….147   DEPARTURE………+10
TOTAL COOLING UNITS FOR THE SEASON…………285   DEPARTURE………+19
TOTAL COOLING UNITS LAST SEASON TO DATE…….268   DIFFERENCE……..+17

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….24  W   AT  1:33 P.M.
ASOS……………………26  W   AT  1:34 P.M.
DAVIS…………………..25  W   AT  1:33 P.M. RMY 26
FASTEST MILE FOR YESTERDAY…………………19  W   AT  1:34 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………20  W   AT  1:34 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..19  WSW AT  1:34 P.M.
AVERAGE WIND SPEED AND DIRECTION……………8.6 W
ASOS……………………9.2
DAVIS…………………..7.5 W  [263 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………..2.99  DEPARTURE…..+0.53
ASOS……………3.01
TOTAL PRECIPITATION FOR THE YEAR………..27.26  DEPARTURE…..-2.17
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings
PRELIMINARY CLIMATE SUMMARY FOR JULY CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

7/1  80/63/72/+2/0.59/466/51               30 SSE RMY 33  TSTM
7/2  78/60/69/-1/0.00/721/79               23 WNW RMY N/A
7/3  79/58/69/-2/0.00/867/95               17 SSW RMY 17
7/4  74/61/68/-3/T/109/12                  16 S   RMY N/A
7/5  82/58/70/-1/0.00/865/95               20 WSW RMY 20
7/6  85/64/75/+4/0.00/755/83               20 S   RMY 21
7/7  84/65/75/+4/0.02/445/49               35 S   RMY 40
7/8  87/68/78/+6/T/372/41                  23 NE  RMY N/A
7/9  73/61/67/-5/…./390/43               24 NE  RMY 25
7/10 80/59/70/-2/…./535/59               18 W   RMY N/A TSTM
7/11 84/61/73/+1/0.00/868/96               21 NW  RMY 19
7/12 88/67/78/+6/0.00/813/90               20 W   RMY 17
7/13 82/66/74/+2/0.00/424/47               21 E   RMY 20
7/14 81/64/73/+1/…./396/44               25 S   RMY 27
7/15 84/61/73/+1/…./…/..               24 ENE RMY 26
7/16 72/56/64/-8/0.00/…/..               25 NNE RMY 24
7/17 79/56/68/-4/0.00/…/..               21 S   RMY N/A
7/18 76/63/70/-2/0.16/…/..               29 SSW RMY 30  TSTM
7/19 89/68/79/+7/0.01/…/..               25 SSW RMY 27
7/20 90/73/82/+10/0.00/…/..              24 W   RMY 26

7/21 low since midnight is 70F; normal low is now 63F

DAILY RECORDS FOR JULY 2015

7/10- NEW RECORD DAILY PRECIPITATION PENDING OF X.XX in 2015
surpasses previous record of 1.68 in. in 1933

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

RECORDS FOR JULY 21
HIGH 100F IN 1977 [RECORD FOR MONTH] LOW 48F IN 1890
PRECIP 2.09 INS IN 1938
PEAK GUST 60e MPH WNW IN 1977

RECORDS FOR JULY 22
HIGH 99F IN 1926, 2011
LOW 52F IN 1890
PRECIP 1.73 INS IN 1900
PEAK GUST 55 MPH IN 1983

TODAY’S REPORT PREPARED BY: Brian Fitzgerald