Thursday, September 24, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, SEPTEMBER 24, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

OVERNIGHT TEMPS DIP TO 50F DURING ARRIVAL OF FALL

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Clear and seasonable days have started to stack one after
another, with yesterday’s very comfortable high of 72F and
overnight low of 56F. Today marks the 11th day in a row
without measurable rainfall that has added to our monthly
and annual deficits. Following yesterday’s dry day, the month
of September is now currently 1.67 inches drier than normal,
and 6.43 inches below normal for the year.

Clear conditions have characterized today once again, and by
the 1:00 PM EST observation only a few cumulus had developed
to our west, along with some cirrus distant to our south and
north. A maximum of 72F had been recorded at the time of
the observation.
Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant N-NNE and SE-SW
Temperature: 61F; Dew Point: 51F; Wind: NNE at 11 kts,
Sea-level pressure: 30.30 ins. Hg, rising, then more slowly
Visibility: 70 miles, light distant haze
6-hr Max temp: 61F
6-hr Min temp: 56F
24-hr precip: none
BHO SA 1155 CLR 70 262/61/51/0211/030/ FEW CI DSNT N-NNE
AND SE-SW LGT DSNT HZ ALQDS/ 8/001 51016 10061 20056

10 A.M.
Weather: Clear, few small cumulus distant WNW-NW, few
cirrus distant S-SW
Temperature: 70F; Dew Point 54F; Wind: ENE at 10 kts,
Sea-level pressure: 30.35 ins. Hg, rising, then more slowly
Visibility: 50 miles, light distant haze
BHO SA 1455 CLR 50 278/70/54/0610/035/ FEW SML CU DSNT
WNW-NW FEW CI DSNT S-SW LGT DSNT HZ ALQDS/ 8/101 51016

1 P.M.
Weather: Clear, few cumulus distant SW-N, few cirrus
N and SW-SE
Temperature: 72F; Dew Point: 48F; Wind: NE 10G16 kts
Sea-level pressure: 30.35 ins. Hg, falling, then more slowly
Visibility: 50 miles, light distant haze
6-hr Max: 72F
6-hr Min: 61F
BHO SA 1755 CLR 50 278/72/48/0510G16/035/ FEW CU DSNT SW-N
FEW CI DSNT N AND SW-SE LGT DSNT HZ ALQDS/ 8/101 50000
10072 20061
SUMMARY FOR WEDNESDAY, SEPTEMBER 23, 2015

TEMPERATURE (DEGREES F)
MAX…..72   NORMAL…..69
MIN…..50   NORMAL…..52
MEAN….61   NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL……………………+1
TOTAL DEPARTURE FOR THE MONTH………………….+124  [+5.2 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE……….-1
TOTAL COOLING UNITS FOR THE MONTH………….131   DEPARTURE………+77
TOTAL COOLING UNITS FOR THE SEASON…………797   DEPARTURE……..+206
TOTAL COOLING UNITS LAST SEASON TO DATE…….571   DIFFERENCE…….+226

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………4   DEPARTURE……….-2
TOTAL HEATING UNITS FOR THE MONTH…………..20   DEPARTURE………-48
TOTAL HEATING UNITS FOR THE SEASON………….21   DEPARTURE………-72
TOTAL HEATING UNITS LAST SEASON TO DATE……..76   DIFFERENCE……..-55

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….15  E   AT 12:06 P.M.
ASOS……………………14  N   AT  7:04 A.M.
DAVIS…………………..13  NNE AT  7:03 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY……………….. 10  N   AT  6:52 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………12  N   AT  7:04 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..10  N   AT  7:04 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..6.5 NNE
ASOS…………………..7.4
DAVIS………………….6.0 NE [045 DEG]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.14
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..1.35  DEPARTURE…..-1.67
ASOS……………1.33
TOTAL PRECIPITATION FOR THE YEAR………..31.60  DEPARTURE…..-6.43
ASOS…………….N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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

9/1  81/65/73/+5/0.00/766/97               20 SSW RMY 20
9/2  89/64/77/+9/0.00/732/93               20 SW  RMY 21
9/3  85/66/76/+9/T/612/78                  17 E   RMY N/A TSTM
9/4  72/58/65/0/0.00/297/38                31 ENE RMY N/A
9/5  77/55/66/-1/0.00/748/96               14 SW  RMY 18
9/6  87/57/72/+5/0.00/753/97               21 SSW RMY 22
9/7  92/63/78/+12/0.00/727/94              23 WSW RMY 24
9/8  97/70/84/+18/0.00/693/90              22 WSW RMY 24
9/9  92/70/81/+15/0.00/683/89              30 SSW RMY 33
9/10 73/62/68/+3/…./000/00               29 NE  RMY N/A
9/11 70/59/65/0/…./084/11                33 NE  RMY N/A
9/12 75/58/67/2/…./380/50                18 SSE RMY 25
9/13 66/60/63/-1/…./000/00               25 E   RMY N/A
9/14 70/53/62/-2/0.00/550/73               33 W   RMY 35
9/15 82/56/69/+5/0.00/736/98               23 W   RMY N/A
9/16 84/62/73/+10/0.00/711/95              17 NW  RMY N/A
9/17 87/64/76/+13/0.00/723/97              17 SW  RMY 16
9/18 86/64/75/+13/0.00/712/96              21 SSW RMY 21
9/19 80/62/71/+9/0.00/…/..               22 S   RMY N/A
9/20 74/55/65/+3/T/…./…                24 S   RMY N/A
9/21 65/50/58/-3/0.00/…/..               29 ENE RMY 30
9/22 67/55/61/+0/0.00/…/..               21 E   RMY 21
9/23 72/50/61/+1/0.00/…/..               15 E   RMY 19

9/24 low since midnight is 56F; normal low is now 52F

DAILY RECORDS FOR SEPTEMBER 2015

**9/7 DAILY RECORD MAXIMUM TEMPERATURE OF 92F
TIES PREVIOUS RECORD SET IN 2007**

**9/8 DAILY RECORD MAXIMUM TEMPERATURE OF 97F
BREAKS PREVIOUS RECORD OF 93F SET IN 2007**

**9/8 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F
BREAKS PREVIOUS RECORD OF 69F SET IN 1999**

**9/9 DAILY RECORD MAXIMUM TEMPERATURE OF 92F
BREAKS PREVIOUS RECORD OF 91F SET IN 2002**

**9/9 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F
BREAKS PREVIOUS RECORD OF 69F SET IN 1999**

**9/17 DAILY RECORD MAXIMUM TEMPERATURE OF 87F
BREAKS PREVIOUS RECORD OF 86F SET IN 1915, 1941, AND 1991**

**9/18 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 64F
TIES PREVIOUS RECORD SET IN 1992**

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

RECORDS FOR SEPTEMBER 24
HIGH 87F IN 1959
LOW 33F IN 1885,1950,1963
PRECIP 1.19 INCHES IN 1955
PEAK GUST 54e MPH SW IN 1940

RECORDS FOR SEPTEMBER 25
HIGH 87F IN 1970
LOW 31F IN 1950
PRECIP 2.68 INCHES IN 1961
PEAK GUST 63 MPH SSW IN 1991

TODAY’S REPORT PREPARED BY: Brian Fitzgerald