Wednesday, September 13, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 13, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

MOSTLY SUNNY THROUGH EARLY AFTERNOON

Warm temperatures and sunny skies continue for
another day before the remnants of Hurricane Irma
bring more moisture and the risk of thunderstorms
to the area.  Yesterday’s max. temp. was 84F which
made the day 6F above normal.  Temps. had again
risen in the low 80F’s by 1:00PM today.

Winds took on a more southerly direction late this
morning, bringing light haze into the region.
Visibility was 50-60 miles during each observation.

Today’s Observations:

7 A.M.
Weather: Few cirrus ESE-S
Temperature: 63F; Dew Point: 53F; Wind: NW at 8 kts
Sea-level pressure: 29.91 ins. Hg, rising then steady
Visibility: 60 miles
6-hr Max temp: 63F
6-hr Min temp: 59F
24-hr Precip:  0.00 in.
BHO SA 1155 CLR 60 130/63/53/3208/991/ FEW CI ESE-S/
8/001 51009 10063 20059

10 A.M.
Weather: Few cirrus SSW-WNW
Temperature: 74F; Dew Point: 55F; Wind: estimated WNW at 2 kts,
Wind: Light and variable
Sea-level pressure: 29.92 ins. Hg, rising then falling
Visibility: 60 miles, distant haze in all directions
BHO SA 1455 CLR 60 131/74/55/E3002/992/ FEW CI SSW-WNW DSNT HZ ALQDS
WND L/V/ 8/001 50001

1 P.M.
Weather: Few altocumulus E, scattered cirrus
Temperature: 82F; Dew Point: 54F; Wind: W at 6 kts,
Wind speed: Light
Sea-level pressure: 29.87 ins. Hg, falling, then more quickly
Visibility: 50 miles, distant haze in all directions
6-hr Max temp: 82F
6-hr Min temp: 63F
BHO SA 1755 250 SCT 50 116/82/54/2606/987/ FEW AC E DSNT HZ ALQDS WND LGT/
8/089 58015 10082 20063

SUMMARY FOR TUESDAY, SEPTEMBER 12, 2017

TEMPERATURE (DEGREES F)
MAX…..84   NORMAL…..73
MIN…..58   NORMAL…..56
MEAN….71   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMAL…………………….+6
TOTAL DEPARTURE FOR THE MONTH……………………-28 [-2.5 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………6   DEPARTURE……….+4
TOTAL COOLING UNITS FOR THE MONTH…………..20   DEPARTURE………-17
TOTAL COOLING UNITS FOR THE SEASON…………627   DEPARTURE………+53
TOTAL COOLING UNITS LAST SEASON TO DATE…….843   DEPARTURE……..-216

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-3
TOTAL HEATING UNITS FOR THE MONTH…………..31   DEPARTURE……….+9
TOTAL HEATING UNITS FOR THE SEASON………….57   DEPARTURE………+10
TOTAL HEATING UNITS LAST SEASON TO DATE……..11   DEPARTURE………+46

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….22 WSW AT 4:04 P.M.
AERO……………………18 WSW AT 4:04 P.M.
ASOS……………………23 WSW AT 4:04 P.M.
DAVIS………………….N/A                  RMY 23
FASTEST MILE FOR YESTERDAY…………………16 WSW AT 8:44 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………17  W  AT 4:27 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….N/A
AVERAGE WIND SPEED AND DIRECTION………….10.8  W
ASOS………………….10.9
DAVIS………………….9.0 WNW [288 DEG.] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.52  DEPARTURE……+0.04
ASOS…………..1.55
TOTAL PRECIPITATION FOR THE YEAR……….37.88  DEPARTURE……+1.38
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system 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
M:    Missing data

9/1  68/47/58/-10/0.00/749/95              26 WNW AERO 28 WNW RMY 31
9/2  72/46/59/-9/0.00/542/69               18 NNW AERO 18 NNW RMY 21
9/3  63/52/58/-9/0.24/000/00               33 W   AERO 33 W   RMY 37
9/4  79/55/67/0/0.00/702/90                29 SSW AERO 28 SSW RMY N/A
9/5  84/62/73/+6/0.00/583/75               36 S   AERO 32 S   RMY 38
9/6  76/59/68/+1/0.49/070/09               28 S   AERO 28 S   RMY 30
9/7  74/58/66/0/0.79/…/..                24*WSW AERO 23 WSW RMY 24
9/8  74/53/64/-2/T/…/..                  21 WSW AERO 18 WSW RMY 22
9/9  68/51/60/-5/T/…/..                  18 ENE AERO 16 ENE RMY 18
9/10 71/51/61/-4/0.00/…/..               18 NW  AERO 16 NW  RMY N/A
9/11 77/50/64/-1/0.00/…/..               20 NNW AERO 17 NNW RMY 20
9/12 84/58/71/+6/0.00/…/..               22 WSW AERO 18 WSW RMY 23

9/13 Low temp since midnight is 59F; normal low is now 56F

DAILY RECORDS FOR SEPTEMBER

9/1/17: DAILY RECORD LOW MINIMUM TEMPERATURE OF 47F,
TIES PREVIOUS RECORD SET IN 1975

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

RECORDS FOR SEPTEMBER 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986

RECORDS FOR SEPTEMBER 14
HIGH 90F IN 1931
LOW 34F IN 1911
PRECIP 4.38 INCHES IN 1944 (Great Atlantic Hurricane in 1944)
PEAK GUST 96e MPH E IN 1944 (Great Atlantic Hurricane in 1944)

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle