Saturday, July 12, 2014

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, JULY 12, 2014
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR SKIES AGAIN WITH WARM TEMPERATURES AND LOW HUMIDITY
RECORD DAILY RAINFALL FOR JULY 4 CONFIRMED AS 2.48 INCHES

It’s been another excellent weekend day today, with mostly
clear skies all day and the temperature rising into the 80s.
The air has also been very dry today, with relative humidity
values dropping to below 40% this afternoon, allowing for a
very pleasant day.  The wind has been light and mainly out
of the west and northwest.  Unlike yesterday when a sea breeze
was present for nearly the entire day, we have not seen an
easterly component to the wind so far today.  The NE winds of
yesterday held our high temperature to just 76F, a value which
we exceeded by 11:00 AM this morning. Through 2PM EDT, the high
for today so far is 84F.  The visibility has held steady at
50-55 miles for most of the day.

As suspected, with the data now confirmed, a new record daily
rainfall has been established for July 4th, with 2.48 inches
of rain falling that day this year, easily surpassing the old
record of 1.78 inches in 1950.  An additional 0.27 inches of
rain fell in the early morning hours of the 5th, for a storm
total of 2.75 inches from that event which included the
offshore passage of Arthur along with a cold frontal passage.
This comprises nearly all of our rainfall for the month so far.

Today’s Observations:

7 A.M.
Weather: Clear, cumulus distant SE-SW, altocumulus distant offshore
NE-ESE, few cirrus distant NW, dark smoke layer along horizon SSE-SW
Temperature: 67F; Dew Point: 60F; Wind: WNW at 6 kts
Sea-level pressure: 30.25 ins. Hg, rising then more rapidly
Visibility: 55 miles, distant haze
6-hr max temp: 67F
6-hr min temp: 60F
BHO SA 1155 CLR 55 243/67/60/2906/025/ CU DSNT SE-SW AC DSNT OFFSHR
NE-ESE FEW CI DSNT NW DRK K LYR ALG HRZN SSE-SW DSNT HZ/ 8/131
51005 10067 20060

10 A.M.
Weather: Clear, few small cumulus and cumulus fractus all quadrants
except NE, cirrus distant SW-NNW
Temperature: 78F; Dew Point: 58F; Wind: W at 3 kts,
Wind: Light
Sea-level pressure: 30.24 ins. Hg, rising slightly then falling
Visibility: 55 miles, distant haze
BHO SA 1455 CLR 55 241/78/58/2703/024/ FEW SML CU AND CUFRA ALQDS
XCPT NE CI DSNT SW-NNW DSNT HZ WND LGT/ 8/101 58002

1 P.M.
Weather: Scattered cumulus, scattered cirrus, few higher thin cirrus
Temperature: 83F; Dew Point: 53F; Wind: W at 5 kts,
Wind: Light and variable
Sea-level pressure: 30.20 ins. Hg, falling
Visibility: 50 miles, distant haze
6-hr max temp: 84F
6-hr min temp; 67F
BHO SA 1755 50 SCT 230 SCT 50 228/83/53/2705/020/ FEW HIER THN CI
DSNT HZ WND LGT AND VRB/ 8/101 57013 10084 20067

WEATHER SUMMARY FOR FRIDAY, JULY 11, 2014

TEMPERATURE (DEGREES F)
MAX…..76    NORMAL…..81
MIN…..65    NORMAL…..63
MEAN….69    NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL…………………….-3
TOTAL DEPARTURE FOR THE MONTH……………………+32 [+2.7 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..4   DEPARTURE……….-3
TOTAL COOLING UNITS FOR THE MONTH…………100   DEPARTURE………+29
TOTAL COOLING UNITS FOR THE SEASON………..209   DEPARTURE……….+9
TOTAL COOLING UNITS LAST SEASON TO DATE……282   DIFFERENCE……..-73

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………22 NE   AT 6:04 A.M.
ASOS…………………..24 NE   AT 6:10 A.M.
DAVIS………………….22 NE   AT 6:04 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………..17 NE   AT 5:42 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..17 ENE  AT 6:09 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….15 NE   AT 5:42 A.M.
AVERAGE WIND SPEED AND DIRECTION………….9.5 ENE
ASOS…………………10.0
DAVIS…………………8.5 E [75 deg]

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……….2.80  DEPARTURE……….+1.55
ASOS…………..2.80
TOTAL PRECIPITATION FOR THE YEAR……….27.35  DEPARTURE……….-0.87
ASOS………….27.66

PRELIMINARY CLIMATE SUMMARY FOR JULY 2014 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  85/66/76/+6/0.00/695/76              31 SSW RMY 36
7/2  89/69/79/+9/T/639/70                 33 SSW RMY 38
7/3  91/68/80/+9/0.05/611/67              29 W   RMY 30  TSTM
7/4  72/61/67/-4/2.48/027/03              28 N   RMY N/A TSTM
7/5  77/55/66/-5/0.27/738/81              36 NW  RMY N/A
7/6  83/61/72/+1/0.00/892/98              29 SW  RMY 33
7/7  85/65/75/+4/T/563/62                 33 SW  RMY 38  TSTM [NO RAIN] 7/8  89/70/80/+8/0.00/763/84              31 SW  RMY 38
7/9  86/70/78/+6/0.00/779/86              28 SSW RMY N/A
7/10 80/65/73/+1/0.00/…/..              16 NW  RMY N/A
7/11 76/62/69/-3/0.00/…/..              22 NE  RMY N/A

7/12 morning low of 60F; the normal low is now 63F

DAILY RECORDS FOR JULY 2014
7/4- NEW DAILY RECORD RAINFALL OF 2.48 ins;
surpasses previous record of 1.78 ins. in 1950

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

RECORDS FOR JULY 12
HIGH 97F IN 1943
LOW 48F IN 1945
PRECIP 1.43 INS IN 1975
WIND 48e MPH SSW IN 1944

RECORDS FOR JULY 13
HIGH 95F IN 1894
LOW 52F IN 1888, 1895, 1939, 1973
PRECIP 3.54 INS IN 1996
WIND 55 MPH SE IN 1996

TODAY’S REPORT PREPARED BY: Jonathan O’Brien