Daily Discussion

| May 11, 2013 | Reply

BLUE HILL METEOROLOGICAL OBSERVATORY

MILTON, MASSACHUSETTS

ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

 

DAILY DISCUSSION AND CLIMATE SUMMARY

SATURDAY, MAY 11, 2013

ALL TIMES ARE IN EASTERN STANDARD TIME

 

LIGHT RAIN OVERNIGHT LEAVES 0.03 INCHES

MOSTLY CLOUDY TODAY WITH INCREASING WINDS AND OCCASIONAL SHOWERS

 

Some light rain fell overnight, leaving a total of just 0.03 inches.

Still, this brings the total since Wednesday to 0.86 inches of much

needed rain, with more possible later today and tonight.

 

This morning began with some thin fog and overcast skies, and a very

light rain shower was observed between 7:05 A.M. and 7:30 A.M., leaving

just a trace of rain.  While there have been a few breaks of Sun during

the rest of the day, the sky has still been predominantly overcast with

mostly stratocumulus and altocumulus clouds.  Visibility increased to

about 30 miles by late morning after it was limited by the thin fog

this morning, but another shower moved in and decreased it again around

12:00 P.M.  This second shower was a bit more intense as the rain was

briefly moderate, and it left 0.02 inches by 1PM.  This rain also cooled

the temperature off quite a bit, as it fell from a high of 70F to 63F

at 1PM.

 

After a couple days of light winds, the wind has been stronger today

out of the SSW.  The average speed so far has been over 15mph, with a

peak gust so far of 43mph preceding the day’s second rain shower.

 

Today’s observations:

 

7 A.M.

Weather: Scattered stratus fractus, broken altocumulus, overcast

altocumulus, Sun dimly visible

Temperature: 58F; Dew Point: 57F; Wind: SSW at 12 kts

Sea-level pressure: 29.85 ins. Hg, falling then steady

Visibility: 10 miles, increasing, thin fog all quadrants

24-hour precip: 0.03 inches

6-hour min. temp: 56F

BHO SA 1155 7 SCT E75 BKN 100 OVC 10 108/58/57/2012/985/ SUN DMLY VSBL

VSBY INCRSNG TF ALQDS 8/77/ 56003 MANUAL 70003 ASOS 70003 10059 20056

 

10 A.M.

Weather: Scattered stratocumulus, broken altocumulus (2 layers),

overcast cirrus, few stratus fractus, breaks in overcast S-W,

Sun visible

Temperature: 69F; Dew Point: 59F; Wind: SSW at 15G24 kts,

Wind: Peak wind of 24 kts SSW at 9:44 A.M.

Sea-level pressure: 29.83 ins. Hg, falling then falling more slowly

Visibility: 30 miles, distant haze

6-hour precip: Trace

BHO SA 1455 20 SCT E70 BKN 110 BKN 250 OVC 30 101/69/59/2115G24/983/

FEW STFRA BINOVC S-W SUN VSBL DSNT HZ 8/871 55007 6000/

 

1 P.M.

Weather: Light rain, broken stratus fractus, broken stratocumulus,

overcast altocumulus, rain showers/virga all quadrants

Temperature: 63F; Dew Point: 61F; Wind: SSW at 15G25 kts,

Wind: Peak wind of 37 kts from the SSW at 12:17 P.M.

Sea-level pressure: 29.81 ins. Hg, falling then rising

Visibility: 20 miles

6-hour precip: 0.05 inches

6-hour max. temp: 70F

BHO SA 1755 E8 BKN 20 BKN 75 OVC 20R- 096/63/61/2015G25/981/

SHRA/VIRGA   ALQDS PK WND 2137/17 8/77/ 55006 MANUAL 6/0005 ASOS 6/0005

10070 20058

 

WEATHER SUMMARY FOR FRIDAY, MAY 10, 2013

 

TEMPERATURE (DEGREES F)

MAX…..79     NORMAL…..65

MIN…..54     NORMAL…..46

MEAN….66     NORMAL…..55

 

DEPARTURE FROM 30-YEAR NORMAL………………..+11

TOTAL DEPARTURE FOR THE MONTH……………….+25 [+2.3 DEGREE/DAY]

 

HEATING DEGREE DAYS 

TOTAL HEATING UNITS FOR YESTERDAY………….0   DEPARTURE………-10

TOTAL HEATING UNITS FOR THE MONTH…………85   DEPARTURE………-28

TOTAL HEATING UNITS FOR THE SEASON………5607   DEPARTURE……..-541

TOTAL HEATING UNITS LAST SEASON TO DATE….4843   DIFFERENCE…….+764

 

PEAK GUST AND AVERAGE WIND SPEED (MPH)

PEAK WIND GUST FOR YESTERDAY……………18 S   AT  10:53 P.M.

                   AERO………………..21 S   AT  10:28 P.M. *

                   ASOS………………..21 SSW AT  10:53 P.M.

                   DAVIS……………….21 S   AT   6:19 P.M. RMY: N/A

THE FASTEST MILE FOR YESTERDAY………….16 S   AT   6:19 P.M.

MAXIMUM 2-MINUTE ASOS AVERAGE…………..16 S   AT   6:21 P.M.

MAXIMUM 2-MINUTE DAVIS AVERAGE………….16 S   AT   6:21 P.M.

AVERAGE WIND SPEED AND DIRECTION……….7.8 S

                   ASOS……………….8.1

                   DAVIS………………6.9 SW [218 deg]

*Last of several occurrences…

 

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)

TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.03  DEPARTURE………..-0.09

                         ASOS…………..0.03

TOTAL PRECIPITATION FOR THE MONTH……….0.86  DEPARTURE………..-0.36

                         ASOS…………..0.83

TOTAL PRECIPITATION FOR THE YEAR……….17.24  DEPARTURE………..-2.53

                         ASOS…………..N/A*

*ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals

                       

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)

TOTAL SNOWFALL 24 HRS ENDING 7 A.M………0.0   DEPARTURE………….0.0

TOTAL SNOWFALL FOR THE MONTH……………0.0   DEPARTURE………….0.0

TOTAL SNOWFALL FOR THE SEASON………….99.0   DEPARTURE………..+36.3

 

PRELIMINARY CLIMATE SUMMARY FOR MAY 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

                             

5/1  67/45/56/+3/0.00/845/100        18 E   AERO 16 MPH E   RMY 17

5/2  75/43/59/+6/T/669/79            29 NE  AERO 26 MPH NE  RMY 29

5/3  54/42/48/-5/0.00/706/83         24 NE  AERO 25 MPH NE  RMY 28

5/4  55/40/48/-6/0.00/843/99         21 NE  AERO 23 MPH NE  RMY 23  

5/5  58/37/48/-6/0.00/752/88         17 ENE AERO 17 MPH ENE RMY 20

5/6  66/40/53/-1/0.00/…/..         17 S   AERO 18 MPH S   RMY 20

5/7  77/50/64/+9/0.00/…/..         21 S   AERO 23 MPH S   RMY 25

5/8  71/55/63/+8/0.42/…/..         31 SSE AERO 35 MPH SSE RMY 35 TSTM

5/9  66/56/61/+6/0.41/…/..         16 NE  AERO 16 MPH NE  RMY 18 TSTM

5/10 79/54/66/+11/…/…/..         18 S   AERO 21 MPH S   RMY N/A

 

5/11 morning low temp: 56F; the normal low is now 46F

 

DAILY RECORDS FOR MAY 2013

None so far.

 

DAILY EXTREMES

Temperature and precipitation records back to 1885, and

wind records back to 1940 (e = estimated):

 

RECORDS FOR MAY 11

HIGH 90F IN 1993

LOW 28F IN 1900

PRE 1.28 INS IN 1957

SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD)

PEAK GUST 75e MPH NW IN 1945

 

RECORDS FOR MAY 12

HIGH 88F IN 2001

LOW 29F IN 1907

PRECIP 1.49 INCHES IN 1968

PEAK GUST 76 MPH S IN 1974

 

TODAY’S REPORT PREPARED BY: Jonathan O’Brien

 

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