Daily Discussion

| July 23, 2013 | Reply

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, JULY 23, 2013
ALL TIMES ARE IN EASTERN STANDARD TIME

MORNING SHOWERS AND DENSE FOG GIVE WAY TO
WARM, HUMID CONDITIONS AND HEAVY AFTERNOON DOWNPOURS

Conditions began warm, muggy, and foggy.  Visibility was reduced to 1/16th
of a mile due to dense until around mid morning.  As the fog dissipated,
a few peaks of sunshine helped warm temperatures into the upper 70s, with
dew point temperatures not too far behind.

A few thunderstorms developed across the area late this morning and early
this afternoon with very heavy downpours.  A thunderstorm and brief heavy
downpour early this afternoon dropped a quick quarter of an inch of rain
on the summit.  Winds also gusted to 35 mph from the WSW in association
with the thunderstorm.

Total rainfall for the day stands at 0.55 inch through 3:30 P.M. EDT.  This
is the first measurable rainfall since 0.08 inch fell on July 13.

A warm front moved through the area this morning.  The wind direction
through much of the morning was ENE-NE as we were positioned north of the
warm front.  With its passage late this morning, the wind direction slowly
shifted to a S direction.

BHO Greatest Number of 90-Degree Days per Month, (1885-2013)
1) 14 in July 1952
2) 13 in August 2002
3) 10 in August 1944
10 in July 1949
10 in July 1963
10 in July 2010
10 in July 2013 (through 7/22)
8)  9 in July 1911
9 in August 1928
10) 8 in August 1949
8 in July 1963
8 in July 1988

Today’s Observations:

7 A.M.
Weather: Sky obscured by dense fog and light rain, stratus drifting over
summit, very light and intermittent drizzle became light rain at 6:05 A.M.
EST, moderate rain fell 6:40-6:50 A.M. EST, light rain continued
Temperature: 70F; Dew Point: 70F; Wind: SE at 8 kts.
Sea-level pressure: 29.72 ins. Hg, falling
Visibility: 1/16 mile, light rain and dense fog
24-hr precip: 0.10 inch
6-hr precip: 0.10 inch
6-hr min. temp: 68F
BHO SA 1155 W2 X 1/16R-F 064/70/70/1408/972/ STRA DRFTNG OVR SMT L- VRY
LGT AND INTMT BCMG R-05 RB40E50 R- CTD/ 8//// 56014 ASOS 70010 MANUAL 70010
ASOS 60010 MANUAL 60010 10070 20068

10 A.M.
Weather: Light drizzle, scattered stratus/stratus fractus, broken
stratocumulus (2 levels), broken altocumulus (2 levels), few stratus
fractus drifting below summit NE-S-W, cumulonimbus SSE moving ENE, rain
shower NE-SE moving ENE, light rain ended at 9:05 A.M. EST, moderate rain
shower began at 9:30 A.M. EST, becoming light at 9:48 A.M. EST, becoming
light drizzle at unknown time and continued
Temperature: 73F; Dew Point: 72F; Wind: S at 8 kts,
Wind: Direction variable SSE-SSW
Wind: Direction gradually veering (clockwise)
Sea-level pressure: 29.66 ins. Hg, falling
Visibility: 30 miles, NE-ESE 6 miles, WNW 35 miles, light drizzle
3-hr precip: 0.19 inch
BHO SA 1455 3 SCT E20 BKN 40 BKN 80 BKN 120 BKN 30L- 043/73/72/1808/966/
FEW STFRA DRFTNG BLO SMT NE-S-W VSBY NE-ESE 6 WNW 35 CB SSE MOVG ENE SHRA
NE-SE MOVG ENE WND 15V21 WND GRDLY VEERING PST HR R- LGT E05 RWB30 BCMG
RW-48 BCMG L-UKN CTD/ 8/870 56021 ASOS 60020 MANUAL 60019

1 P.M.
Weather: Broken stratocumulus/cumulus, broken stratocumulus, broken
altocumulus, few stratus fractus drifting below summit all quadrants, few
low cumulus over city to the N, towering cumulus distant SW, cumulonimbus
distant WSW-NNW moving ENE, rain shower/thunderstorm NNE-E and S-SSW and
distant W-N moving ENE, thunder ended at 12:13 P.M. EST, light rain shower
began at 12:14 P.M. and ended at 12:19 P.M. EST, moderate rain shower began
at 12:27 P.M. EST, briefly heavy rain shower 12:29-31 P.M. EST, thunder
began at unknown time, moderate thundershower becoming light at 12:34 P.M.
EST, becoming very light at 12:44 P.M. EST, thunder ended at unknown time,
light rain shower ended at 12:54 P.M. EST
Temperature: 75F; Dew Point: 74F; Wind: SSW at 6 kts,
Wind: Peak wind of 30 kts. from the WSW at 12:28 P.M. EST
Wind: Wind shift began at 12:25 P.M. EST
Sea-level pressure: 29.60 ins. Hg, falling
Visibility: 20 miles, W-N-E and S 6 miles, ESE-SSE 20 miles, SSW-WSW 25
miles
6-hr precip: 0.45 inch
6-hr max. temp: 78F
BHO SA 1755 E15 BKN 45 BKN 100 BKN 20 025/75/74/2106/960/ FEW STFRA
DRFTNG BLO SMT ALQDS FEW LW CU OVR CTY N TCU DSNT SW CB DSNT WSW-NNW MOVG
ENE VSBY W-N-E AND S 15 ESE-SSE 20 SSW-WSW 25 SHRA/TS NNE-E AND S-SSW AND
DSNT W-N MOVG ENE PK WND 2530/28 WND SHFT 25 TE13 RW-B14E19B26 RWB27
BRFLY RW+29-31 TBUKN TRW BCMG TRW-34 BCMG VRY LGT 44 TEUKN RW-E54/ 8/970
56018 ASOS 60047 MANUAL 60045 10078 20070

WEATHER SUMMARY FOR MONDAY, JULY 22, 2013

TEMPERATURE (DEGREES F)
MAX…..80     NORMAL…..81
MIN…..67     NORMAL…..63
MEAN….74     NORMAL…..72

DEPARTURE FROM 30-YEAR NORMAL………………….+2
TOTAL DEPARTURE FOR THE MONTH………………..+128 [+5.6 DEGREES/DAY]

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY…………….17 NE  AT  3:37 P.M. *
AERO…………………17 NE  AT  3:37 P.M. *
ASOS…………………20 NE  AT  3:33 P.M.
DAVIS………………..18 NE  AT  3:32 P.M.  RMY 19
FASTEST MILE FOR YESTERDAY………………13 ENE AT  5:22 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………14 E   AT  5:53 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………..13 NE  AT  3:12 P.M.
AVERAGE WIND SPEED AND DIRECTION………..7.7 E
ASOS………………..7.3
DAVIS……………….7.0 E [092 deg.]
*last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.10   DEPARTURE…………-0.03
ASOS…………..0.10
TOTAL PRECIPITATION FOR THE MONTH……….1.11   DEPARTURE…………-1.61
ASOS…………..1.10
TOTAL PRECIPITATION FOR THE YEAR……….33.31   DEPARTURE…………+3.62
ASOS…………..N/A*
*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

PRELIMINARY CLIMATE SUMMARY FOR JULY 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

7/1  82/69/76/+6/0.05/247/27         29 S   AERO 31 MPH SSW RMY 32
7/2  82/61/72/+2/T/100/11            23 SSW AERO 23 MPH SSW RMY 25
7/3  87/62/75/+4/T/556/61            28 SW  AERO 30 MPH SW  RMY 30
7/4  90/71/81/+10/0.00/811/89        25 WSW AERO 26 MPH SW  RMY 28
7/5  92/73/83/+12/0.00/874/96        24 W   AERO 25 MPH WSW RMY 25
7/6  90/73/82/+11/0.00/836/92        25 WNW AERO 25 MPH WNW RMY 26
7/7  91/72/82/+11/0.21/508/56        38 SSW AERO 43 MPH SSW RMY 44  TSTM
7/8  82/64/73/+1/0.04/617/68         18 NE  AERO 20 MPH NE  RMY 20  TSTM
7/9  72/63/68/-4/0.01/054/06         14 ENE AERO 14 MPH ENE RMY 14
7/10 84/65/75/+3/T/335/37            32 S   AERO 36 MPH S   RMY 35
7/11 79/69/74/+2/0.62/009/01         23 W   AERO 23 MPH W   RMY N/A TSTM
7/12 70/62/66/-6/0.00/162/18         29 NE  AERO 29 MPH NE  RMY 30
7/13 75/62/69/-3/0.08/009/01         21 ENE AERO 20 MPH ENE RMY N/A
7/14 89/71/80/+8/0.00/477/53         16 W   AERO 16 MPH W   RMY 16
7/15 91/72/82/+10/0.00/665/74        17 NW  AERO 16 MPH NW  RMY 18
7/16 91/71/81/+9/0.00/843/94         18 NNW AERO 16 MPH NNW RMY 16
7/17 93/74/84/+12/0.00/841/94        22 SW  AERO 23 MPH SW  RMY 25
7/18 90/75/83/+11/0.00/724/81        20 S   AERO 21 MPH S   RMY 22
7/19 95/76/86/+14/0.00/723/81        36 WSW AERO 38 MPH WSW RMY 38
7/20 93/72/82/+10/0.00/570/64        29 W   AERO 30 MPH W   RMY 31 TSTM
7/21 82/68/75/+3/0.00/568/64         16 NE  AERO 16 MPH NE  RMY 17
7/22 80/67/74/+2/T/…/..            17 NE  AERO 17 MPH NE  RMY 19

7/23 morning low temp: 68F; the normal low is now 63F

DAILY RECORDS FOR JULY 2013
7/14 – TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 71F;
ties previous record of 71F set in 1997
7/15 – NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 72F;
surpasses previous record of 70F set in 1901, 1934, 1995
7/16 – TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 71F;
ties previous record of 71F set in 1901, 1958, 1968
7/17 – TIED DAILY RECORD HIGH MINIMUM TEMPERATURE OF 74F;
ties previous record of 74F set in 1900
7/18 – NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 75F;
surpasses previous record of 73F set in 1900, 1999
7/19 – NEW DAILY RECORD HIGH MINIMUM TEMPERATURE OF 76F;
surpasses previous record of 72F set in 1949, 1991, 2005

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

RECORDS FOR JULY 23
HIGH 99F IN 1952
LOW 51F IN 1923,1977
PRECIP 1.82 INCHES IN 1953
PEAK GUST 54e MPH S IN 1946

RECORDS FOR JULY 24
HIGH 96F IN 1987
LOW 49F IN 1893,1912
PRECIP 2.27 INCHES IN 2008
PEAK GUST 46 MPH NE IN 2009

TODAY’S REPORT PREPARED BY: Sean Fankhauser

Category: Daily Discussions

Leave a Reply