Sunday, July 31, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, JULY 31, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

CHILLY, DAMP, AND CLOUDY WITH SHOWERS

A seasonal start to the morning has given way to colder temperatures
as temperatures fall into the mid 60’s from this morning’s high of 71.
A dense fog was just North of the Observatory at the 7 o’clock
observation and the fog quickly enveloped the observatory shortly
after 8:30 AM EDT.

Yesterday’s rainfall of 0.41 inches put a nice dent in the dry
conditions at the observatory which is good as the U.S. Drought Monitor
released on July 28 place Blue Hill right on the boundary between
a moderate and severe drought.

The heat wave that ended Thursday with 92 degrees is ranked
our third longest heat wave, 7 days. See listing below:

The last day of the heat wave was also the 11th day of 90-degree
heat this month. This ranks as the second greatest total of
90-degree days for July.  See listing below:

BHO Longest Heat Waves (Consecutive Days with Tmax 90F or more; 1885-2016):
1) 9 days, Aug 11-19, 2002
2) 8 days, Aug 10-17, 1944
3) 7 days, Jul 22-28, 2016
4) 6 days, Aug 28-Sep 2, 1953
6 days, Jul 24-29, 1963
6 days, Jul 16-21, 1977
6 days, Jul 6-11, 1988
6 days, Jul 16-21, 1991
6 days, Jul 15-20, 2013
10) 5 days, Jul 2-6, 1911
5 days, Jul 7-11, 1912
5 days, Aug 25-29, 1948
5 days, Aug 7-11, 1949
5 days, Jul 15-19, 1982
5 days, Jul 14-18, 2012

BHO July Greatest Number of 90-Degree Days (1885-2016):
1) 14 in 1952
2) 11 in 2016
3) 10 in 1949
10 in 1963
10 in 2010
10 in 2013
7) 9 in 1911
8) 8 in 1983
8 in 1988

Today’s Observations:

7 A.M.
Weather: Overcast Stratus, Few Cumulus Fractus, Fog WNW-E
Temperature: 71F; Dew Point: 69F; Wind: N at 5 kts,
Wing: Light
Sea-level pressure: 30.07 ins. Hg, steady
Visibility: 20 miles, haze, except WNW-E 1/2 mi Fog
6-hr Max temp: 85F
6-hr Min temp: 65F
24-hr precip: 0.41 in.
BHO SA 1155 15 OVC 20 184/71/69/0405/007/ FEW CUFRA E-SW
VSBY 0.5 MI WNW-E FOG HAZY E-WNW WND LGT/ 8/7// 50016
MANUAL 70041 ASOS 70040 10071 20070

10 A.M.
Weather: Sky obscured in dense Fog and Mist
Temperature: 68F; Dew Point: 68F; Wind: N at 11 kts,
Sea-level pressure: 30.10 ins. Hg, rising slightly
Visibility: 1/8 Fog and Mist
3-hr precip: 0.02 inches
BHO SA 1455 X W/ 1/8F 194/68/68/0111/010/ FOG AND MIST/ 51010
MANUAL 60002 ASOS 60002

1 P.M.
Weather: Sky partly obscured in fog, overcast
Temperature: 68F; Dew Point: 68F; Wind: n at 9 kts,
Sea-level pressure: 30.09 ins. Hg, steady then falling
Visibility: 1 mile, Fog
6-hr Max temp: 71F
6-hr Min temp: 68F
6-hr precipitation: 0.15 inches
BHO SA 1755 -X E80 OVC 1F 191/68/68/0409/009/ F// 8/6// 58003
MANUAL 60015 ASOS 60012 10071 20068

SUMMARY FOR SATURDAY, JULY 30, 2016

TEMPERATURE (DEGREES F)
MAX…..85   NORMAL…..81
MIN…..65   NORMAL…..63
MEAN….75   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL…………………….+3
TOTAL DEPARTURE FOR THE MONTH……………………+102 [+3.4 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..10   DEPARTURE……….+3
TOTAL COOLING UNITS FOR THE MONTH………….313   DEPARTURE………+98
TOTAL COOLING UNITS FOR THE SEASON…………470   DEPARTURE……..+126
TOTAL COOLING UNITS LAST SEASON TO DATE…….381   DIFFERENCE……..+89

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….21  SE  AT   6:46 P.M.
AEROVANE………………..18  SE  AT   6:46 P.M.
ASOS……………………20  W   AT   6:45 P.M.
DAVIS…………………..18  W   AT   6:45 P.M. RMY 20
FASTEST MILE FOR YESTERDAY…………………12  NNW AT   4:55 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………14  WSW AT   6:46 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..13  WSW AT   6:46 P.M.
AVERAGE WIND SPEED AND DIRECTION……………7.7 ENE
ASOS……………………7.5
DAVIS…………………..6.9 NE [052 Deg.] *Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.41  DEPARTURE……+0.26
ASOS…………..0.40
TOTAL PRECIPITATION FOR THE MONTH……….1.35  DEPARTURE……-2.60
ASOS…………..1.27
TOTAL PRECIPITATION FOR THE YEAR……….23.04  DEPARTURE……-7.88
ASOS………….23.39

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/+3/0.01/360/40                 38 S   AERO 41 S   RMY 43
7/15 93/71/82/+10/0.00/665/74                23 W   AERO 23 W   RMY 23
7/16 93/69/81/+9/0.00/699/78                 25 WSW AERO 24 WSW RMY 24
7/17 83/72/78/+6/0.00/671/75                 18 ENE AERO 16 ENE RMY 19 TSTM
7/18 93/70/82/+10/0.05/500/56                41 WNW AERO 41 WNW RMY 43 TSTM
7/19 85/62/74/+2/0.00/802/90                 28 NW  AERO 28 NW  RMY 27
7/20 83/59/71/-1/0.00/837/94                 23 NW  AERO 23 NW* RMY 24
7/21 89/63/76/+4/0.00/852/96                 28 W   AERO 26 W   RMY N/A
7/22 96/70/83/+11/0.09/806/91                33 SW  AERO 35 SW  RMY 35 TSTM
7/23 95/68/82/+10/T/…/..                   45 NNW AERO 48 NNW RMY 44
7/24 91/64/78/+6/0.00/…/..                 20 WNW AERO 20 W*  RMY 20
7/25 96/70/83/+11/0.00/…/..                25 S   AERO 28 S   RMY 27
7/26 95/70/83/+11/0.00/…/..                26 W   AERO 26 WNW*RMY 27
7/27 94/68/81/+9/0.00/…/..                 21 ESE AERO 21 WNW RMY 19
7/28 92/71/82/+10/0.00/…/..                23 SW  AERO 22 SW  RMY 23
7/29 80/68/74/+2/0.15/…/..                 20 NNW AERO 20 NNW RMY 20
7/30 85/65/75/+3/0.41/…/..                 21 SE  AERO 18 SE  RMY 20

7/31 Low temp since midnight is F; normal low is now 63F

DAILY RECORDS FOR JULY 2016
7/25/16: NEW DAILY RECORD MAXIMUM TEMPERATURE OF 96F,
BREAKS PREVIOUS RECORD OF 94F SET IN 1963 AND 1987

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

RECORDS FOR JULY 31
HIGH 95F IN 1917
LOW 50F IN 1895,1918
PRECIP 1.34 INS IN 1892
PEAK GUST 43e MPH WNW IN 1953, 43 SW IN 1971

RECORDS FOR AUGUST 1
HIGH 97F IN 1917
LOW 49F IN 1891
PRECIP 3.61 INCHES IN 1927
PEAK GUST 41 MPH NNW IN 1985

TODAY’S REPORT PREPARED BY: Robert Millette