Sunday, October 18, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, OCTOBER 18, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR AND COLD THIS MORNING BUT GIVING WAY TO FAIR
WEATHER CLOUDS

While several areas saw their first snowfalls of the
year yesterday, Blue Hills was not among them with
only a trace of rain earlier in the day.  Temperatures
have struggled to climb out of the lower 40’s despite
sunny conditions on the summit. Cumulus and Stratocumulus
clouds are now moving into the area ahead of another
light batch of rain and snow showers currently to our west
bring showers and virga into the area obscuring small
sectors of visibility.

This morning’s low of 28.9 degrees is the coldest low
so far this season and marks the first time we have been
below freezing since last winter. The cold air was very
clear this morning with visibility reaching 80 miles for
a time and areas that do not have obscuring virga continue
to have visibilities at 70 miles.

Today’s Observations:

7 A.M.
Weather: Few stratus NNW-N, Few Cumulus ENE-SSE over ocean
Temperature: 31F; Dew Point: 23F; Wind: NW at 10 kts,
Sea-level pressure: 30.21 ins. Hg, rising, then more slowly
Visibility: 80 miles
6-hr Max temp: 34F
6-hr Min temp: 28F
24-hr precip: 0.00 ins.
BHO SA 1155 CLR 80 232/31/23/3210/021/ FEW S NNW-N DSNT FEW
CU ENE-SSW DSNT 8/800 53019 10034 20029

10 A.M.
Weather: Few Cumulus
Temperature: 41F; Dew Point 20F; Wind: NW at 7 kts,
Sea-level pressure: 30.21 ins. Hg, falling slightly
Visibility: 70 miles
BHO SA 1455 CLR 70 234/41/20/3107/021/ FEW CU DSNT ALQDS
8/100 50002

1 P.M.
Weather: Broken Cumulus and Stratocumulus
Temperature: 42F; Dew Point 17F; Wind: W at 07G18 kts,
Wind: Peak gust 18 knots
Sea-level pressure: 30.19 ins. Hg, falling then steady
Visibility: 65 miles, except 70 ENE-SSE
BHO SA 1755 E60 BKN 65 225/42/17/3207G18/019/ SHWRS AND
VIRGA DSNT SSE-ENE VSBY 70 ENE-SSE 56009 10042 20031

SUMMARY FOR SATURDAY, OCTOBER 17, 2015

TEMPERATURE (DEGREES F)
MAX…..54   NORMAL…..60
MIN…..35   NORMAL…..42
MEAN….45   NORMAL…..51

DEPARTURE FROM 30-YEAR NORMAL…………………..-6
TOTAL DEPARTURE FOR THE MONTH…………………..+4  [+0.2 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH……………0   DEPARTURE……….-5
TOTAL COOLING UNITS FOR THE SEASON…………810   DEPARTURE……..+208
TOTAL COOLING UNITS LAST SEASON TO DATE…….595   DIFFERENCE…….+215

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..20   DEPARTURE……….+6
TOTAL HEATING UNITS FOR THE MONTH………….168   DEPARTURE………-10
TOTAL HEATING UNITS FOR THE SEASON…………211   DEPARTURE……..-109
TOTAL HEATING UNITS LAST SEASON TO DATE…….240   DIFFERENCE……..-15

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….30   WNW AT  12:08 P.M.
ASOS……………………33   W   AT  12:14 P.M.
DAVIS…………………..31   W   AT   1:14 P.M. RMY 33
FASTEST MILE FOR YESTERDAY…………………23   WNW AT  10:22 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………25   WNW AT  12:58 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..22   WNW AT  11:22 A.M.
AVERAGE WIND SPEED AND DIRECTION………….12.8 WNW
ASOS………………….12.7
DAVIS…………………11.0 WNW [294 Deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M……..T  DEPARTURE…..-0.15
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..1.06  DEPARTURE…..-1.46
ASOS……………1.04
TOTAL PRECIPITATION FOR THE YEAR………..35.20  DEPARTURE…..-6.40
ASOS…………….N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 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

10/1  55/51/53/-4/…./000/00               39 NE  RMY N/A
10/2  51/47/49/-8/…./000/00               40 NE  RMY 43
10/3  51/45/48/-8/…./000/00               38 NE  RMY N/A
10/4  55/49/52/-4/0.00/474/68               35 E   RMY 40
10/5  59/46/53/-3/T/125/18                  21 NE  RMY 20
10/6  68/43/56/+1/0.00/663/96               17 NW  RMY 17
10/7  69/46/58/+3/0.00/640/93               20 W   RMY 20
10/8  63/49/56/+2/0.00/678/99               21 S   RMY N/A
10/9  68/50/59/+5/0.27/…/..               45 S   RMY 49
10/10 59/44/53/-2/0.00/…/..               33 NNW RMY N/A
10/11 67/46/57/+4/0.00/…/..               26 SW  RMY 28
10/12 76/50/63/+10/0.00/…/..              22 SSW RMY 24
10/13 70/55/63/+10/0.27/…/..              23 S   RMY 24
10/14 66/46/56/+4/0.00/…/..               26 W   RMY 29
10/15 60/41/51/-1/0.00/…/..               20 SW  RMY 27
10/16 60/44/52/+1/T/…/..                  31 W   RMY 34
10/17 54/35/45/-6/T/…/..                  30 WNW RMY 33

10/18 low since midnight is 29F; normal low is now 42F

DAILY RECORDS FOR OCTOBER 2015

-NONE SO FAR.

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

RECORDS FOR OCTOBER 18
HIGH 82F IN 1908
LOW 26F IN 1939
PRECIP 2.79 INCHES IN 1975
SNOWFALL 3.0 INCHES IN 2009
PEAK GUST 66 MPH S IN 1967

RECORDS FOR OCTOBER 19
HIGH 81F IN 1945
LOW 21F IN 1922
PRECIP 3.64 INCHES IN 1932
SNOWFALL 1.0 INCHES IN 1972
PEAK GUST 66 MPH SSW IN 1967

TODAY’S REPORT PREPARED BY: Robert Millette