Tuesday, September 24, 2013

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, SEPTEMBER 24, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

COOL, RELATIVELY CALM, AND MOSTLY CLEAR

The low temperature this morning of 40F tied the lowest temperature
observed so far this Fall season which also occurred only one week ago on
the 17th. The afternoon high may reach the mid 60s, but the average
temperature for today is will end up several degrees below the 30-year
normal for the date. That will push the month of September thus far to
1.0 degree below the 30-year normal.

Only a few small cumulus have dotted the sky today along with some high
cirrus. The clouds have mostly been to the N through E of the observatory.

Winds have been calmer today compared to the past few days, generally
averaging around 10-15 mph, with a few gusts near 20 mph.

Visibility continues to be great, although some light distant haze has
brought it down to 80 miles rather than the 90 miles of yesterday.

Today’s Observations:

7 A.M.
Weather: Scattered thin cirrus, few cumulus distant NE-S and distant
WNW-NNW, cirrus distant NNE and distant SW-WNW, thin smoke layer along
horizon all quadrants
Temperature: 43F; Dew Point: 39F; Wind: W at 10 kts.
Sea-level pressure: 29.96 ins. Hg, rising then falling slightly
Visibility: 80 miles
6-hr min. temp: 40F
BHO SA 1155 250 –SCT 80 145/43/39/2810/996/ FEW CU DSNT NE-S AND DSNT
WNW-NNW CI DSNT NNE AND DSNT SW-WNW THN K LYR ALG HRZN ALQDS/ 8/101
58004 10043 20040

10 A.M.
Weather:
Temperature: 55F; Dew Point: 39F; Wind: NW at 10 kts,
Wind: Direction variable W-NNW
Sea-level pressure: 29.92 ins. Hg, falling slightly
Visibility: 80 miles
BHO SA 1455 30 SCT 220 SCT 250 –SCT 80 129/54/41/2810/991/ FEW SML CU FRMG
ALQDS PTCHS DNS CI DSNT N-ENE CI DSNT NNW-ENE AND DSNT SSE-SSW LGT DSNT
HZ WND 24V31/ 8/102 56016

1 P.M.
Weather: Scattered altocumulus, scattered dense cirrus, scattered thin
cirrus, few small cumulus distant ENE-SSE, small cumulus distant NW,
altocumulus/altocumulus lenticularis distant N-ENE, cirrus and patches of
dense cirrus distant NNW-E, patch of cirrus distant SE, light distant haze
Temperature: 62F; Dew Point: 43F; Wind: WNW at 7 kts,
Wind: Direction variable SW-NW
Sea-level pressure: 29.87 ins. Hg, falling
Visibility: 80 miles
6-hr max. temp: 64F
BHO SA 1755 60 SCT 220 SCT 250 –SCT 80 114/62/43/2907/987/ FEW SML CU DSNT
ENE-SSE SML CU DSNT NW AC/ACSL DSNT N-ENE CI AND PTCHS DNS CI DSNT NNW-E
PTCH CI DSNT SE LGT DSNT HZ WND 23V32/ 8/142 58015 10064 20043

WEATHER SUMMARY FOR MONDAY, SEPTEMBER 23, 2013

TEMPERATURE (DEGREES F)
MAX…..63 NORMAL…..69
MIN…..43 NORMAL…..52
MEAN….53 NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL…………………-7
TOTAL DEPARTURE FOR THE MONTH………………..-13 [-0.8 DEGREE/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY…………..0 DEPARTURE………-1
TOTAL COOLING UNITS FOR THE MONTH………….56 DEPARTURE………+2
TOTAL COOLING UNITS FOR THE SEASON………..696 DEPARTURE…….+105
TOTAL COOLING UNITS LAST SEASON TO DATE……765 DIFFERENCE…….-69

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….12 DEPARTURE………+6
TOTAL HEATING UNITS FOR THE MONTH………….81 DEPARTURE……..+13
TOTAL HEATING UNITS FOR THE SEASON…………93 DEPARTURE……….0
TOTAL HEATING UNITS LAST SEASON TO DATE…….49 DIFFERENCE…….+44

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………25 NW AT 8:07 A.M.
AERO…………………..26 NW AT 8:07 A.M.
ASOS…………………..26 NW AT 8:08 A.M.
DAVIS………………….24 NW AT 8:13 A.M. RMY 28
FASTEST MILE FOR YESTERDAY………………..18 NW AT 8:19 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..18 NW AT 8:22 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….17 NW AT 8:22 A.M.
AVERAGE WIND SPEED AND DIRECTION…………11.9 NW
ASOS…………………10.6
DAVIS………………..10.1 NW [314 degrees]

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……….3.91 DEPARTURE………….+0.88
ASOS…………..4.04
TOTAL PRECIPITATION FOR THE YEAR……….41.92 DEPARTURE………….+3.87
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/529/69 23 SW AERO 23 MPH SSW RMY N/A
9/10 73/56/65/0/0.03/007/01 30 S AERO 32 MPH S RMY 33
9/11 93/68/81/+16/0.00/654/86 25 SW AERO 27 MPH SW RMY N/A
9/12 85/66/76/+11/0.47/455/60 32 S AERO 33 MPH S RMY 34 TSTM
9/13 79/58/69/+5/0.17/242/32 24 NNW AERO 25 MPH NNW RMY 23
9/14 67/52/60/-4/0.00/361/48 21 NW AERO 21 MPH NW RMY 21
9/15 70/48/59/-5/0.00/547/73 17 WSW AERO 18 MPH WSW RMY 20
9/16 66/46/56/-7/0.02/179/24 29 NNW AERO 31 MPH NNW RMY 30
9/17 60/40/50/-13/0.00/722/97 27 NNE AERO 27 MPH NNE RMY 26
9/18 73/47/60/-2/0.00/726/98 18 W AERO 18 MPH WSW RMY 20
9/19 78/51/65/+3/0.00/731/99 17 WSW AERO 16 MPH WSW RMY 18
9/20 78/54/66/+4/0.00/706/96 18 SSW AERO 18 MPH SSW RMY 23
9/21 74/57/66/+4/T/512/70 35 S AERO 40 MPH S RMY N/A
9/22 70/49/60/-1/0.39/365/50 38 S AERO 39 MPH S RMY 42
9/23 63/43/53/-7/0.00/…/.. 25 NW AERO 26 MPH NW RMY 28

9/24 morning low temp: 40F; the normal low is now 52F

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
9/11 – TIED DAILY RECORD MAXIMUM HIGH TEMPERATURE OF 93F;
ties record of 93F set in 1983

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: Sean Fankhauser