Wednesday, September 11, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, SEPTEMBER 11, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

TRIPLE “H” WEATHER….HOT, HAZY, AND HUMID
MAXIMUM TEMP. JUST SHY OF RECORD AT 2 P.M.
THEN RISES TO 93F AFTER 2 P.M. EQUALING RECORD
THE DEW POINT HAD DROPPED FROM 75F EARLIER to 72F

The maximum temperature was just shy of equaling today’s
record high maximum of 93F set in 1983 as our official
thermometer had reached 92.4F just before 2 P.M. Then
a bit later we equaled the 93-degree record. Dew points continue
to be especially high for September ranging between 70F and 75F today.

Today is extremely humid. The dew point was as high as 70 degrees at 7 am
this morning and 75F later this morning. Along with high humidity our
overnight low was very warm at 68 degrees. That is 12 degrees above the
average low of 58. The heat and humidity will continue throughout the day.
A record high maximum and record high minimum may be both
broken during the next 24 hours.
The high maximum and high minimum for today were both set in 1983 at 93
and 71 degrees.  Tonight’s low may set a new high minimum for
September 12. The record currently stands at 69F in 1925.

By 10 o’clock we had an observed temperature of 84.6 and a wet bulb of 77.0.
This made for a dew point of 74 degrees that also agrees with ASOS. This makes
it a remarkable day of for high heat and humidity for the month of September.
A foggy morning turned into a hazy day. A rather thick haze at mid-morning had
thinned out by early after with visibility increasing from 9 miles at mid-
morning to 15 to 20 miles early this afternoon.

As of 2:45 P.M. my Hingham National Weather Service cooperative station
has set a new daily record of 96F breaking the old 1983 record of 94 degrees
set September 11, 1983.

Today’s Observations:

7 A.M.
Weather: Partially obscured with 1/10, fog, scattered altocumlos
castellanus dissipating past hour, heavy dew and condensation
Temperature: 71F; Dew Point: 70F; Wind: SSW at 8 kts.
Sea-level pressure: 30.09 ins Hg, rising slightly
Visibility: 2 miles in fog
24-hr precip: 0.03
6-hr min. temp: 68F
BHO SA 1155 –X 80 SCT 2F 189/71/70/2108/009/ F1 FEW ACC AND DSSPTNG
PST HR HVY DEW/CONDENSATION ALL SFCS/ 8/080 51005 MANUAL 70003
ASOS 70004 10071 20068

10 A.M.
Weather: Clear, few cirrus SE-SW, Haze layer above horizon SW-N
Temperature: 84F; Dew Point: 74F; Wind: SW at 9 kts,
Sea-level pressure: 30.09 ins. Hg, steady
Visibility: 9 miles, hazy
BHO SA 1455 CLR 9 189/84/74/2209/009/ FEW CI SE-SE HZ LYR ABV
HRZN SW-N HAZY ALQDS/ 8/001 50000

1 P.M.
Weather: Clear, small patch cirrus E-ESE
Temperature: 92F; Dew Point: 72F; Wind: SW at 9 kts,
Wind: Direction variable S-W
Sea-level pressure: 30.05 ins. Hg, falling then more rapidly
Visibility: 15 miles, except 20 miles WNW, hazy
6-hr max. temp: 92F
BHO SA 1755 CLR 15 176/92/72/2209/005/ SML PTCH CI E-SE
VSBY WNW 20 HAZY ALQDS WND 18V27/ 8/001 58013 10092 20071

WEATHER SUMMARY FOR TUESDAY, SEPTEMBER 10, 2013

TEMPERATURE (DEGREES F)
MAX…..73   NORMAL…..74
MIN…..56   NORMAL…..57
MEAN….65   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMA…………..0
TOTAL DEPARTURE FOR THE MONTH………..-18 [-2.0 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……….0  DEPARTURE…..-3
TOTAL COOLING UNITS FOR THE MONTH………23  DEPARTURE…..-9
TOTAL COOLING UNITS FOR THE SEASON…….663  DEPARTURE….+94
TOTAL COOLING UNITS LAST SEASON TO DATE..754  DIFFERENCE…-91

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………..30 S   AT 11:19 A.M.
AERO……………………………..32 S   AT 11:23 A.M. *
ASOS……………………………..33 S   AT 11:20 A.M.
DAVIS…………………………….32 S   AT 11:19 A.M. RMY 33
FASTEST MILE FOR YESTERDAY………….23 S   AT 11:35 A.M.*
MAXIMUM 2-MINUTE ASOS AVERAGE……….23 SSW AT 11:32 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE………22 S   AT 11:00 A.M.
AVERAGE WIND SPEED AND DIRECTION…..15.3 SSW
ASOS…….14.3
DAVIS…….14.4 SSW [200 degrees] * last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.03  DEPARTURE…..-0.10
ASOS……0.04
TOTAL PRECIPITATION FOR THE MONTH……….2.86  DEPARTURE…..+1.63
ASOS……2.95
TOTAL PRECIPITATION FOR THE YEAR……….40.87  DEPARTURE…..+4.62
ASOS……N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER 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

9/1  76/67/72/+4/2.32/008/01  33 S AERO 39 MPH S RMY 38 TSTM
9/2  79/67/73/+5/0.43/056/07  30 SSE AERO 33 MPH SSE RMY N/A TSTM
9/3  79/61/70/+3/0.00/219/28  28 S AERO 29 MPH S RMY 30 TSTM
9/4  78/57/68/+1/0.00/733/94  24 W AERO 25 MPH W RMY 25
9/5  66/51/59/-8/0.08/179/23  20 NNE AERO 20 MPH NNE RMY 21
9/6  68/46/57/-10/0.00/751/97 18 WSW AERO 17 MPH WSW RMY N/A
9/7  78/51/65/-1/0.00/594/77  20 WSW AERO 21 MPH WSW RMY 21
9/8  74/50/62/-4/0.00/646/84  31 NW AERO 33 MPH NW   RMY 32
9/9  69/47/58/-8/T/../…/..  23 SW AERO 23 MPH SSW  RMY N/A
9/10 73/56/65/0/0.03/…/..   30 S  Aero 32 MPH S    RMY 33

9/11 morning low temp: 68F; the normal low is now 56F

DAILY RECORDS FOR SEPTEMBER 2013
9/1 – NEW DAILY RECORD MAXIMUM PRECIPITATION OF 2.32 INCHES;
surpasses previous record of 1.60 inches set in 1927

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

RECORDS FOR SEPTEMBER 11
HIGH 93F IN 1983
LOW 37F IN 1917
PRECIP 5.23 INCHES IN 1954 (HURRICANE EDNA)
PEAK GUST 101 MPH NW IN 1954 (HURRICANE EDNA)

RECORDS FOR SEPTEMBER 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)

TODAY’S REPORT PREPARED BY: Robert Skilling and Kevin Pecora