Wednesday, September 30, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 30, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

2.16 INCHES OF HEAVY RAINS OVERNIGHT AND THIS MORNING,
WINDS GUST TO 47 MPH BY MID DAY

Rain showers began last evening, bringing less than
a tenth of an inch, according to the ASOS gauge. Steadier
and heavier rain began in earnest this morning after 5:00
AM EST, with 0.92 inches falling by the 7:00 AM EST observation,
followed by an additional 0.97 inches by the 10:00 AM
EST observation. Gusty winds from the SE, then shifting SW
by mid day, were recorded as high as 51 MPH on the RMY, 47
MPH on the 420c 3-cup anemometer, and 50 MPH on ASOS.

By the 1:00 PM EST observation and additional 0.27 inches
had fallen, with the line of heavy showers visible from the
SW-N just ahead of a cold front. A maximum of 74F was recorded
by that time as well.

Today’s daily record for precipitation is 1.93 inches, set
back in 1946, and although hourly precipitation has not been
finalized for today’s date, it is likely that we have broken
today’s record. More details to follow in the coming days
and monthly statistics.
Today’s Observations:

7 A.M.
Weather: Moderate rain, fog
Temperature: 70F; Dew Point: 70F; Wind: SE at 19G26 kts,
Peak Wind: 32 knots SE @ 6:34 AM EST
Sea-level pressure: 29.76 ins. Hg, pressure falling rapidly
Visibility: 3 miles, except 2 miles S, obscured by moderate
rain and fog
6-hr Max temp: 71F
6-hr Min temp: 70F
24-hr precip: 0.92 inches
BHO SA 1155 W3 X 3RF 079/70/70/1319G26/976/
VSBY S 2 MI PK WND 1332/34/ PRESFR/ 8////
58030 ASOS 60079 70088 MANUAL 70092 10071 20070

10 A.M.
Weather: Light rain, fog, overcast stratus, few
cumulus fractus in all directions
Temperature: 72F; Dew Point 72F; Wind: S at 22G24 kts,
Peak Wind: 36 knots S @ 9:21 AM EST
Sea-level pressure: 29.69 ins. Hg, falling, then more slowly
Visibility: 4 miles, except 2 miles WNW-NNW, light rain
and fog
3-hr precip: 0.97 inches
BHO SA 1455 E6 OVC 4R-F 054/72/72/1922G34/969/ VSBY WNW-NNW 2 MI
FEW CUFRA ALQDS PK WND 1836/21/ 8/6// 56025 ASOS 60101 MANUAL 60097

1 P.M.
Weather: Overcast stratus, broken stratus fractus,
showers distant SW-N, bright spots overhead
Temperature: 73F; Dew Point: 72F; Wind: S at 16G24 kts
Peak Wind: 25 knots S @ 12:08 PM EST
Sea-level pressure: 29.69 ins. Hg, decreasing, then more slowly
Visibility: 15 miles, except 6 miles WSW-WNW, obscured by
showers and thin fog
6-hr Max: 74F
6-hr Min: 70F
6-hr precip: 1.24 inches
BHO SA 1755 E11 BKN 32 OVC 15 053/73/72/1916G24/969/
SHWRS DSNT SW-N VSBY WSW-WNW 6 MI BRGT SPTS OVHD
THN FG ALQDS PK WND 1925/08/ 8/6// 56001
ASOS 60133 MANUAL 60124 10074 20070
SUMMARY FOR TUESDAY, SEPTEMBER 29, 2015

TEMPERATURE (DEGREES F)
MAX…..82   NORMAL…..67
MIN…..65   NORMAL…..49
MEAN….74   NORMAL…..58

DEPARTURE FROM 30-YEAR NORMAL…………………..+16
TOTAL DEPARTURE FOR THE MONTH………………….+151  [+5.0 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………9   DEPARTURE……….+8
TOTAL COOLING UNITS FOR THE MONTH………….144   DEPARTURE………+85
TOTAL COOLING UNITS FOR THE SEASON…………810   DEPARTURE……..+214
TOTAL COOLING UNITS LAST SEASON TO DATE…….587   DIFFERENCE…….+223

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-8
TOTAL HEATING UNITS FOR THE MONTH…………..41   DEPARTURE………-68
TOTAL HEATING UNITS FOR THE SEASON………….42   DEPARTURE………-92
TOTAL HEATING UNITS LAST SEASON TO DATE……..91   DIFFERENCE……..-49

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….28 S   AT  5:10 P.M.*
ASOS……………………30 S   AT  4:59 P.M.
DAVIS…………………..28 SSW AT  4:00 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY……………….. 23 S   AT  4:17 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………23 S   AT  4:18 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..21 SSW AT  4:18 P.M.
AVERAGE WIND SPEED AND DIRECTION…………. .12.6 SSW
ASOS……………………12.7
DAVIS…………………..11.5 SSW [200 DEG]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.92  DEPARTURE…..+0.77
ASOS……………0.88
TOTAL PRECIPITATION FOR THE MONTH………..2.27  DEPARTURE…..-1.64
ASOS……………2.21
TOTAL PRECIPITATION FOR THE YEAR………..32.52  DEPARTURE…..-6.40
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/-2/0.00/297/38               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 N/A
9/24 72/56/64/+4/0.00/…/..               22 E   RMY 21
9/25 66/53/60/0/0.00/…/..                21 E   RMY 20
9/26 63/49/56/-3/0.00/…/..               25 ENE RMY 25
9/27 71/46/59/+0/0.00/…/..               17 S   RMY 18
9/28 81/57/69/+11/0.00/…/..              22 SSW RMY 24
9/29 82/65/74/+16/…./…/..              28 S   RMY N/A

9/30 low since midnight is 70F; normal low is now 49F

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 30
HIGH 84F IN 1986
LOW 31F IN 1992
PRECIP 1.93 INCHES IN 1946
PEAK GUST 58 MPH SSE IN 1999

RECORDS FOR OCTOBER 1
HIGH 85F IN 1927
LOW 30F IN 1992
PRECIP 1.63 INCHES IN 2014
PEAK GUST 68e MPH SSE IN 1977

TODAY’S REPORT PREPARED BY: Brian Fitzgerald