Sunday, October 20, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, OCTOBER 20, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

DRY, MILD WEATHER CONTINUES

The temperature is running above average again today, with a warm morning low
of 49F and an afternoon high so far of 61F, which is slightly above average.  A
cold front passed over the summit early this morning, but this has done little to
cool the temperature.  Yesterday was another above average day, extending the
streak of at or above average temperatures to 23 days, and today will probably be
the 24th.  The month of October continues to run 5 degrees above average.  A shift
to a cooler pattern is forecast for later this week which should finally bring this
stretch of above average weather to an end.

The cold frontal passage last night did not bring any rainfall to the summit,
as the air was just too dry for precipitation to make it to the surface.  Our
monthly precipitation deficit is nearing two inches, and our yearly precipitation
surplus has now fallen under one inch.  The dew point today has fallen to 32F, the
lowest it has been in months, with very low humidity values of around 35% this
afternoon.  The sky has been mostly clear throughout the day.  Visibility has been
excellent today, up to 80 miles.  Winds have been brisk out of the WNW behind the
front today, with a peak gust of 29mph and an average speed of around 15mph.

Today’s Observations:

7 A.M.
Weather: Clear, few cumulus distant NW-NNW and NE-E, few stratus fractus SW and
W-WNW, altocumulus distant ESE-S, few cirrus distant E, heavy dew/condensation,
thin smoke layer S-SW
Temperature: 49F; Dew Point: 42F; Wind: WNW at 13G21 kts
Sea-level pressure: 29.80 ins. Hg, rising then rising more rapidly
Visibility: 75 miles, light distant haze
6-hr min temp: 49F
BHO SA 1155 CLR 75 091/49/42/2913G21/980/ FEW CU DSNT NW-NNW AND NE-E
FEW STFRA SW AND W-WNW AC DSNT ESE-S FEW CI DSNT E HVY DEW/CONDENSATION
THN K LYR S-SW LGT DSNT HZ/ 8/131 53024 10053 20049

10 A.M.
Weather: Clear, few cumulus distant N-NNE, few small stratocumulus distant SW-NNE,
altocumulus distant E-SSE, few cirrus SE
Temperature: 55F; Dew Point: 38F; Wind: WNW at 13G24 kts,
Wind: Direction variable W-NW
Sea-level pressure: 29.85 ins. Hg, rising then rising more slowly
Visibility: 80 miles
BHO SA 1455 CLR 80 108/55/38/2913G24/985/ FEW CU DSNT N-NNE
FEW SML SC DSNT SW-NNE AC DSNT E-SSE FEW CI SE WND 26V32/ 8/131 51017

1 P.M.
Weather: Clear, stratocumulus distant SE-S, few cumulus fractus SSE, altocumulus
distant SE-S, thin cirrus mostly distant SE-SW
Temperature: 60F; Dew Point: 32F; Wind: WNW at 13G24 kts,
Wind: Direction variable WSW-NNW
Sea-level pressure: 29.85 ins. Hg, rising then falling
Visibility: 80 miles
6-hr max temp: 61F
BHO SA 1755 CLR 80 108/60/32/2913G22/985/ SC DSNT SW-NNE AND E FEW CUFRA SSE
AC DSNT SE-S THN CI MSTLY DSNT SE-S WND 24V34/ 8/531 50000 10061 20049

WEATHER SUMMARY FOR SATURDAY, OCTOBER 19, 2013

TEMPERATURE (DEGREES F)
MAX…..65    NORMAL…..59
MIN…..45    NORMAL…..42
MEAN….55    NORMAL…..50

DEPARTURE FROM 30-YEAR NORMAL…………………+5
TOTAL DEPARTURE FOR THE MONTH…………………+98  [+5.0 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0   DEPARTURE……….0
TOTAL COOLING UNITS FOR THE MONTH…………..5   DEPARTURE……….0
TOTAL COOLING UNITS FOR THE SEASON………..701   DEPARTURE……..+99
TOTAL COOLING UNITS LAST SEASON TO DATE……767   DIFFERENCE…….-66

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..10  DEPARTURE……..-5
TOTAL HEATING UNITS FOR THE MONTH………….123  DEPARTURE……..-98
TOTAL HEATING UNITS FOR THE SEASON…………269  DEPARTURE……..-94
TOTAL HEATING UNITS LAST SEASON TO DATE…….294  DIFFERENCE…….-25

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………21 W   AT   1:46 A.M. *
AERO…………………..22 W   AT  12:48 A.M.
ASOS…………………..23 W   AT  12:49 A.M.
DAVIS………………….22 W   AT  12:48 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY………………..19 W   AT   1:16 A.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..17 W   AT   1:19 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….17 W   AT  12:51 A.M.
AVERAGE WIND SPEED AND DIRECTION………….11.2 S
ASOS………………….10.8
DAVIS…………………10.2 SW [218 degrees] * last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00   DEPARTURE………….-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.98   DEPARTURE………….-1.85
ASOS…………..0.97
TOTAL PRECIPITATION FOR THE YEAR……….42.90   DEPARTURE………….+0.99
ASOS…………..N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

PRELIMINARY CLIMATE SUMMARY FOR OCTOBER 2013 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized

10/1  75/50/63/+6/0.00/676/96         16 WNW AERO 16 MPH WNW RMY 18
10/2  78/56/67/+10/0.00/666/95        29 W   AERO 30 MPH W   RMY 29
10/3  77/56/67/+11/0.00/628/90        20 WNW AERO 20 MPH WNW RMY N/A
10/4  67/56/62/+6/0.26/028/04         18 NW  AERO 20 MPH NW  RMY N/A
10/5  67/56/62/+6/0.01/125/18         14 ENE AERO 12 MPH ENE RMY N/A
10/6  58/53/56/+1/0.56/000/00         20 NE  AERO 20 MPH NE  RMY N/A
10/7  75/57/66/+11/0.07/213/31        48 S   AERO 55 MPH S   RMY 55
10/8  65/50/58/+4/0.00/581/85         25 NW  AERO 27 MPH NW  RMY 28
10/9  59/49/54/0/0.00/545/80          25 ENE AERO 24 MPH ENE RMY 25
10/10 61/46/54/0/0.00/095/14          18 NE  AERO 17 MPH NE  RMY 18
10/11 67/50/59/+6/0.00/473/70         20 NE  AERO 20 MPH NE  RMY N/A
10/12 59/50/55/+2/0.02/007/01         30 ENE AER0 31 MPH ENE RMY 32
10/13 59/46/53/0/0.00/482/72          23 ENE AERO 23 MPH ENE RMY 23
10/14 64/42/53/+1/0.00/580/87         15 SSW AERO 15 MPH SSW RMY 15
10/15 66/50/58/+6/0.00/266/40         16 ESE AERO 16 MPH ESE RMY N/A
10/16 60/49/55/+4/0.00/013/02         23 ESE AERO 24 MPH ESE RMY 23
10/17 70/52/61/+10/0.06/…/..        21 S   AERO 23 MPH S   RMY N/A
10/18 67/50/59/+8/0.00/…/..         32 WNW AERO 32 MPH W   RMY 31
10/19 65/45/55/+5/0.00/…/..         21 W   AERO 22 MPH W   RMY N/A

10/20 the morning low temp: 49F; the normal low is now 41F

DAILY RECORDS FOR OCTOBER 2013
None so far.

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

RECORDS FOR OCTOBER 20
HIGH 78F IN 1965,1984
LOW 24F IN 1972
PRECIP 7.10 INCHES IN 1996 (RECORD FOR MONTH)
SNOWFALL TRACE IN 1934,1943
PEAK GUST 63 MPH W IN 1966

RECORDS FOR OCTOBER 21
HIGH 79F IN 1979
LOW 24F IN 1974
PRECIP 2.39 INCHES IN 1944
SNOWFALL TRACE IN 1895,1907,1940
PEAK GUST 69e MPH S IN 1976

TODAY’S REPORT PREPARED BY: Jonathan O’Brien