Saturday, October 17, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, OCTOBER 17, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

SHOWERS AND VIRGA MOVE THROUGH THIS MORNING…
COLDER AND DRIER AIR MOVING IN TODAY…

Friday was another day close to the expected ‘normal’
temperatures with a maximum of 60F and a minimum (just
before midnight) of 44F.  The low temperature this
morning of 41F matches the coldest of the season to
date previously observed on the 15th.  In advance of
a relatively dry cold front approaching New England,
a few light showers and virga passed through eastern
Massachusetts early this morning.  Only a trace of
rainfall was measured on the summit.  At the time,
the visibility was near 75 miles, which provided a
dramatic view of the passing showers. Partial sunshine
and gusty winds have dominated since mid-morning,
with the temperature struggling to reach the low
50s at mid-day.  The dew point has dropped from 38-39F
this morning to the middle 20s this afternoon, setting
the stage for possible freezing temperatures the
next two nights.

Today’s Observations:

7 A.M.
Weather: Broken stratocumulus, broken nimbostratus,
overcast altocumulus, few lower stratus fractus,
stratocumulus castellanus distant NE-S, breaks in overcast
distant WSW-NW and distant ENE-SE, rain showers and virga
SSW-NNW moving east
Temperature: 42F; Dew Point: 38F; Wind: W at 10 kts,
Sea-level pressure: 29.99 ins. Hg, falling, then more slowly
Visibility: 75 miles
6-hr Max temp: 44F
6-hr Min temp: 41F
24-hr precip: 0.00 ins.
BHO SA 1155 E45 BKN 85 BKN 120 OVC 75 156/42/38/2810/999/
FEW LWR STFRA SCCAS DSNT NE-S BINOVC DSNT WSW-NW AND DSNT
ENE-SE RW/VIRGA SSW-NNW MVNG E/ 8/57/ 51007 6000/ 10044 20041

10 A.M.
Weather: Scattered cumulus/stratocumulus, few cumulus
fractus, few altocumulus lenticularis distant ENE-SSE
Temperature: 49F; Dew Point 29F; Wind: W at 20G24 kts,
Sea-level pressure: 29.99 ins. Hg, falling slightly
Visibility: 75 miles
3-hr precip: Trace
BHO SA 1455 45 SCT 75 157/49/29/2820G24/999/ FEW CUFRA FEW
ACSL DSNT ENE-SSE/ 8/540 50001 6000/

1 P.M.
Weather: Scattered cumulus mediocris, few cumulus fractus
Temperature: 50F; Dew Point 25F; Wind: W at 13G23 kts,
Wind: Peak gust 26 knots, W at 12:38 P.M.
Sea-level pressure: 29.98 ins. Hg, falling
Visibility: 80 miles
6-hr precip: Trace
BHO SA 1755 55 SCT 80 154/50/25/2713G23/998/ FEW CUFRA PK WND
2726/38/ 8/100 58004 6000/ 10052 20042

SUMMARY FOR FRIDAY, OCTOBER 16, 2015

TEMPERATURE (DEGREES F)
MAX…..60   NORMAL…..60
MIN…..44   NORMAL…..43
MEAN….52   NORMAL…..51

DEPARTURE FROM 30-YEAR NORMAL……………………+1
TOTAL DEPARTURE FOR THE MONTH…………………..+10  [+0.4 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…………..13   DEPARTURE……….-1
TOTAL HEATING UNITS FOR THE MONTH………….162   DEPARTURE………-16
TOTAL HEATING UNITS FOR THE SEASON…………205   DEPARTURE……..-115
TOTAL HEATING UNITS LAST SEASON TO DATE…….239   DIFFERENCE……..-34

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….31   W AT  8:32 A.M.
ASOS……………………37   W AT  8:32 A.M.
DAVIS…………………..32   W AT  8:30 A.M. RMY 34
FASTEST MILE FOR YESTERDAY…………………25   W AT  8:59 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………24   W AT  9:00 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..22   W AT  8:59 A.M.
AVERAGE WIND SPEED AND DIRECTION………….13.7 WNW
ASOS………………….13.4
DAVIS…………………12.3 W [264 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…..-1.31
ASOS……………1.04
TOTAL PRECIPITATION FOR THE YEAR………..35.20  DEPARTURE…..-6.25  **Annual total corrected
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 low since midnight is 41F; 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 17
HIGH 86F IN 1947
LOW 25F IN 1886
PRECIP 1.87 INCHES IN 1989
SNOWFALL TRACE IN 1970
PEAK GUST 55 MPH NE IN 1964

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

TODAY’S REPORT PREPARED BY: Mike Iacono