Sunday, July 17, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARIES
SUNDAY, JULY 17, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

COOLER TODAY WITH A HIGHER RISK OF STORMS

Yesterday tied the warmest temperatures of the year so far, with the high
of 93F just 3 degrees short of tying the daily record.  Some showers and storms
are developing southeast of the Observatory this afternoon, but no rainfall
has been recorded here.

Warm weather has continued today, with a high temperature so far of 81F.  Dew
points are higher today than yesterday, however, in the mid 60s for most of the
day, with relative humidity values remaining near 60%.  A steady onshore breeze
established itself by late morning, with gusts to near 20mph, keeping the heat a
little more bearable.  Visibility was poor today with hazy conditions keeping
visibilities below 40 miles all day.

In the hour after the 1 PM EST observation time, a thunderstorm formed to the
south to southwest of the observatory and spread its anvil of high cirrus clouds
to the northeast over the hill as the storm moved to the east.  Distant thunder
was heard for about an hour after 1:40 PM EST.

Today’s Observations:

7 A.M.
Weather: Broken cirrostratus, few cumulus all quadrants, few altocumulus
all quadrants
Temperature: 74F; Dew Point: 66F; Wind: NW at 8 kts
Sea-level pressure: 30.08 ins. Hg, rising then rising more slowly
Visibility: 20 miles, haze
6-hr Max temp: 76F
6-hr Min temp: 72F
24-hr precip: 0.00 in.
BHO SA 1155 150 BKN 20 187/74/66/3108/008/ FEW CU ALQDS FEW AC ALQDS HAZY/
8/186 51011 10076 20072

10 A.M.
Weather: Few cumulus to the ESE-ENE
Temperature: 78F; Dew Point: 64F; Wind: N at 9 kts,
Sea-level pressure: 30.10 ins. Hg, rising then steady
Visibility: 25 miles, haze
BHO SA 1455 250 SCT 25 196/78/64/0109/010/ FEW CU ESE-ENE HAZY/ 8/1/6 51009

1 P.M.
Weather: Clear, few cumulus NE-S, few cirrus NE-S
Temperature: 81F; Dew Point: 65F; Wind: NNE at 7 kts,
Sea-level pressure: 30.08 ins. Hg, steady then falling
Visibility: 35 miles,  hazy
6-hr Max temp: 81F
6-hr Min temp: 74F
BHO SA 1755 CLR 35 187/81/65/0207/008/ FEW CU NE-S FEW CI NE-S HAZY/
8/1/2 58009 10081 20074

SUMMARY FOR SATURDAY, JULY 16, 2016

TEMPERATURE (DEGREES F)
MAX…..93   NORMAL…..81
MIN…..69   NORMAL…..63
MEAN….81   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL…………………..+9
TOTAL DEPARTURE FOR THE MONTH……………………+8 [+0.3 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..16   DEPARTURE………+9
TOTAL COOLING UNITS FOR THE MONTH………….121   DEPARTURE………+14
TOTAL COOLING UNITS FOR THE SEASON…………278   DEPARTURE………+42
TOTAL COOLING UNITS LAST SEASON TO DATE…….250   DIFFERENCE……..+31

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….25  WSW    AT  12:42 P.M.
AEROVANE………………..24  WSW    AT  12:41 P.M.
ASOS……………………26  W      AT  12:42 P.M.
DAVIS…………………..24  WSW    AT  11:32 P.M. RMY 24
FASTEST MILE FOR YESTERDAY…………………17  WSW    AT  12:39 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18  W      AT  12:48 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..18  WSW    AT  12:44 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.0  SSW
ASOS…………………..9.3
DAVIS………………….8.2  WSW [250 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……….0.65  DEPARTURE……-1.28
ASOS…………..0.61
TOTAL PRECIPITATION FOR THE YEAR……….22.34  DEPARTURE……-6.56
ASOS………….22.73

PRELIMINARY CLIMATE SUMMARY FOR JULY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system 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  84/67/76/+6/0.20/520/57                 32 S   AERO 35 S   RMY 34 TSTM
7/2  76/61/69/-1/0.00/811/91                 31 W   AERO 34 W   RMY 32
7/3  83/57/70/-1/0.00/766/84                 23 W   AERO 23 W   RMY 23
7/4  87/61/74/+3/0.00/847/93                 28 SSW AERO 28 SSW RMY 28
7/5  80/65/73/+2/0.29/309/34                 16 S   AERO 16 S   RMY N/A
7/6  92/68/80/+9/0.00/864/95                 22 WSW AERO 24 WSW RMY 22
7/7  77/61/69/-2/0.00/409/45                 21 NE  AERO 20 ENE RMY N/A
7/8  67/58/63/-9/0.02/000/00                 25 NE  AERO 25 NE  RMY 26
7/9  64/57/61/-11/0.09/000/00                20 NE  AERO 18 NE  RMY 17
7/10 66/56/61/-11/0.04/000/00                16 NE  AERO 16 NE  RMY 16
7/11 77/56/67/-5/0.00/415/46                 20 NNE AERO 21 NNE RMY 20
7/12 86/60/73/+1/0.00/848/94                 23 S   AERO 23 S   RMY 23
7/13 89/64/77/+5/0.00/874/97                 30 S   AERO 30 S   RMY 33
7/14 84/66/75/+3/0.01/…/..                 38 S   AERO 41 S   RMY 43
7/15 93/71/82/+10/0.00/…/..                23 W   AERO 23 W   RMY 23
7/16 93/69/81/+9/0.00/…/..                 25 WSW AERO 24 WSW RMY 24

7/17 low temp since midnight is 72F; normal low is now 63F

DAILY RECORDS FOR JULY 2016
None so far.

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

RECORDS FOR JULY 17
HIGH 96F IN 1999
LOW 47F IN 1892
PRECIP 1.39 INS IN 1989
WIND 46 MPH WNW IN 1971

RECORDS FOR JULY 18
HIGH 96F IN 1991, 1999
LOW 54F IN 1892, 1956, 1971
PRECIP 1.65 INS IN 2000
WIND 43e MPH SW IN 1949

TODAY’S REPORT PREPARED BY: Robert Millette