Friday, July 31, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, JULY 31, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

JULY COMES TO AN END ON A HOT AND DRY NOTE

A line of approaching rain showers and thunderstorms
last evening weakened before reaching the summit of Great
Blue Hill. A total of 0.10 inches of new rain fell, but
this amount still fell below the daily norm of 0.16 inches.
Assuming no rain through today, July will likely end 0.93
inches below normal for the month and 3.63 inches below
normal for the year so far. Yesterday’s daily temperature
departure of +9 along with another warmer than normal
day today will likely push July more than 1 degree above
normal.

Clear and drier conditions this morning have allowed
for mostly blue skies and somewhat better visibility.
By the 1:00 PM EST observation visibility had improved
dramatically to 70 miles as dew points fell from the
upper 60s this morning to the mid 50s this afternoon.
Winds had picked up as well, gusting up to 24 knots.
A maximum temperature of 86F was recorded as well.
Today’s Observations:

7 A.M.
Weather: Clear, few cirrostratus distant ESE-SSW
Temperature: 72F; Dew Point: 67F; Wind: W at 8 kts
Sea-level pressure: 29.84 ins. Hg, rising, then more quickly
Visibility: 40 miles, hazy
6-hr Max temp: 72F
6-hr Min temp: 68F
24-hr precip: 0.10 inches
BHO SA 1155 CLR 40 104/72/67/2608/984/ FEW CS DSNT ESE-SSW HAZY/
8/008 53012 ASOS 70008 MANUAL 70010 10072 20068

10 A.M.
Weather: Clear, few small cumulus in all directions,
few cirrostratus distant E-S
Temperature: 80F; Dew Point 63F; Wind: W at 10 kts
Sea-level pressure: 29.83 ins. Hg, rising, then falling and lower
Visibility: 50 miles, light distant haze
BHO SA 1455 CLR 50 103/80/63/2810/983/ FEW SML CU DSNT ALQDS
FEW CS DSNT E-S LGT DSNT HZ/ 8/108 58001

1 P.M.
Weather: Clear, few small cumulus in all directions,
few cirrostratus distant E-SSW
Temperature: 86F; Dew Point: 58F; Wind: W at 14G23 kts
Sea-level pressure: 29.80 ins. Hg, falling, then more slowly
Visibility: 70 miles
6-hr Max temp: 86F
6-hr Min temp: 71F
BHO SA 1755 CLR 70 091/86/58/2614G23/980/ FEW SML CU ALQDS
FEW CS DSNT E-SSW/ 8/108 56012 10086 20071

SUMMARY FOR THURSDAY, JULY 30, 2015

TEMPERATURE (DEGREES F)
MAX…..89   NORMAL…..81
MIN…..72   NORMAL…..63
MEAN….81   NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL……………………+9
TOTAL DEPARTURE FOR THE MONTH…………………..+41 [+1.2 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..16   DEPARTURE……….+8
TOTAL COOLING UNITS FOR THE MONTH………….243   DEPARTURE………+28
TOTAL COOLING UNITS FOR THE SEASON…………381   DEPARTURE………+37
TOTAL COOLING UNITS LAST SEASON TO DATE…….331   DIFFERENCE……..+50

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….31  S   AT  4:14 P.M.*
ASOS……………………35  SW  AT  4:02 P.M.
DAVIS…………………..32  SSW AT  1:25 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………27  S   AT  4:21 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………26  SSW AT  4:22 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..26  S   AT  4:22 P.M.
AVERAGE WIND SPEED AND DIRECTION……………14.3 SSW
ASOS……………………14.1
DAVIS…………………..13.0 SSW [203 deg.] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.10  DEPARTURE…..-0.06
ASOS……………0.08
TOTAL PRECIPITATION FOR THE MONTH………..3.09  DEPARTURE…..-0.78
ASOS……………3.09
TOTAL PRECIPITATION FOR THE YEAR………..27.36  DEPARTURE…..-3.48
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/-5/0.08/390/43               24 NE  RMY 25
7/10 80/59/70/-2/1.95/535/59               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/…./297/33               24 ENE RMY 26
7/16 72/56/64/-8/0.00/852/95               25 NNE RMY 24
7/17 79/56/68/-4/0.00/708/79               21 S   RMY N/A
7/18 76/63/70/-2/0.16/027/03               29 SSW RMY 30  TSTM
7/19 89/68/79/+7/0.01/509/57               25 SSW RMY 27
7/20 90/73/82/+10/0.00/793/89              24 W   RMY 26
7/21 87/70/79/+7/T/267/30                  24 W   RMY 25
7/22 82/64/73/+1/T/727/82                  24 WNW RMY 26
7/23 81/62/72/+0/0.00/753/85               22 W   RMY 23
7/24 80/60/70/-2/T/663/75                  23 N   RMY 25
7/25 71/59/65/-7/0.00/265/30               20 ENE RMY N/A
7/26 78/59/69/-3/T/…/..                  24 SSE RMY 25  TSTM
7/27 84/67/76/+4/T/…/..                  24 S   RMY N/A TSTM
7/28 89/68/79/+7/0.00/…/..               18 S   RMY N/A
7/29 92/70/81/+9/0.00/…/..               21 W   RMY N/A
7/30 89/72/81/+9/0.10/…/..               31 S   RMY N/A

7/31 low since midnight is 68F; normal low is now 63F

DAILY RECORDS FOR JULY 2015

7/10 – RECORD DAILY PRECIPITATION OF 1.95 INCHES,
surpasses previous record of 1.68 in. in 1933
7/20 – RECORD DAILY HIGH MINIMUM TEMPERATURE OF 73F,
ties previous record of 73F in 1977

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: Brian Fitzgerald