Sunday, May 4, 2014

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 4, 2014
ALL TIMES ARE IN EASTERN STANDARD TIME

MOSTLY CLOUDY, BREEZY DAY WITH A FEW SHOWERS

Cumulus and stratocumulus clouds were already developing by 7:00 this morning.
The stratocumulus quickly became dominant and have covered much of the sky
throughout the day.  The resulting lack of sunshine has kept the temperature
quite cool into the early afternoon, only in the mid-upper 50s.  While we have
reached 59F for a high so far, much of the time has been spent below this.
The wind has made it feel a bit cooler than that as well, with a steady west
wind of 15-20mph and gusts up to 35mph.  A few light rain showers have
provided just 0.01 inches of rain to the summit so far.  Several of these
showers have been observed developing, mostly to our west and north, but they
have struggled to become intense thanks in part to very dry air, with the dew
point generally in the mid 30s today, although the rain has helped bring it
up some this afternoon.

APRIL 2014 PRELIMINARY STATISTICS

[Departures are relative to the 1981-2010 averages]

TEMPERATURE: Deg. F
Avg. Max. 55.9 [+0.2] Avg. Min. 37.5 [-0.2] Mean      46.7 [0.0] 24-hr. corrected mean: 46.1
Max. temp: 73 on the 14th
Min. temp: 28 on the 16th and 18th
Total heating degree day units: 544 [-7] Total seasonal heating units:  6,171  [+136] [Season starts 7/1] Seasonal total this date 2012: 5,522 [+649]

PRECIPITATION: Inches
Total: 4.00 [-0.55] Greatest in 24 hours: 1.22 inches on the 15th
Total snowfall: 0.8 inches
Greatest in 24 hours:  0.8 inches on the 16th

WIND
Av. speed (uncorrected): 13.6 mph
Av. speed (corrected):   13.9 mph
Prevailing direction: NW @ 13% possible

SUNSHINE
Total astronomical minutes: 11,946 of possible 24,094 or 50%
Total Campbell-Stokes card minutes; 11,508 of possible 23,250 or 49%

Today’s Observations:

7 A.M.
Weather: Clear, cumulus and cumulus fractus distant SW-NE, altocumulus mostly
distant S-SW and NW-NE
Temperature: 53F; Dew Point: 43F; Wind: WSW at 13G20 kts
Sea-level pressure: 29.65 ins. Hg, falling then falling more rapidly
Visibility: 60 miles, light distant haze
6-hr max temp: 53F
6-hr min temp: 49F
24-hr precip: Trace
BHO SA 1155 CLR 60 042/53/43/2513G20/965/ CU AND CUFRA DSNT SW-NE
AC MSTLY DSNT S-SW AND NW-NE LGT DSNT HZ/ 8/150 58006 MANUAL 7000/
10053 20049

10 A.M.
Weather: Broken stratocumulus cumulogenitus, altocumulus distant SE-S, rain
showers NW and N
Temperature: 57F; Dew Point: 32F; Wind: W at 15G24 kts,
Sea-level pressure: 29.59 ins. Hg, falling then falling more slowly
Visibility: 80 miles, except 50 miles NW and N
BHO SA 1455 E55 BKN 80 020/57/32/2715G24/959/ AC DSNT SE-S SHRA NW AND N
VSBY NW AND N 50/ 8/450 56022

1 P.M.
Weather: Light rain shower, broken stratocumulus cumulogenitus
Temperature: F; Dew Point: F; Wind:  at  kts,
Wind: Peak wind of 29 kts W @ 12:34 P.M.
Sea-level pressure: 29.55 ins. Hg, falling then falling more slowly
Visibility: 60 miles
6-hr max temp: 65F
6-hr min temp: 53F
6-hr precip: 0.01 inches
BHO SA 1755 E55 BKN 60RW- 008/54/40/21G30/955/ PK WND 2730/53/ 8/400 56012
MANUAL 60001 10059 20053

WEATHER SUMMARY FOR SATURDAY, MAY 3, 2014

TEMPERATURE (DEGREES F)
MAX…..66    NORMAL…..63
MIN…..48    NORMAL…..44
MEAN….57    NORMAL…..53

DEPARTURE FROM 30-YEAR NORMAL…………………….+4
TOTAL DEPARTURE FOR THE MONTH…………………….+12 [+3.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………8  DEPARTURE……….-4
TOTAL HEATING UNITS FOR THE MONTH…………..24  DEPARTURE………-13
TOTAL HEATING UNITS FOR THE SEASON………..6195  DEPARTURE……..+123
TOTAL HEATING UNITS LAST SEASON TO DATE……5554  DIFFERENCE…….+641

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………21 SW   AT  10:14 P.M. *
ASOS…………………..23 SW   AT  9:07 P.M.
DAVIS………………….21 S    AT  6:16 P.M.  RMY N/A
FASTEST MILE FOR YESTERDAY………………..17 SSW  AT  8:44 P.M. *
MAXIMUM 2-MINUTE ASOS AVERAGE……………..17 SSW  AT  8:46 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….17 SSW  AT  8:45 P.M.
AVERAGE WIND SPEED AND DIRECTION………….9.7  S
ASOS…………………10.4
DAVIS…………………8.8  SW [226 deg] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…Trace  DEPARTURE………….-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….0.49  DEPARTURE………….+0.12
ASOS…………..0.51
TOTAL PRECIPITATION FOR THE YEAR……….19.61  DEPARTURE………….+0.69
ASOS………….20.04

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…………..85.6  DEPARTURE………….+22.9

PRELIMINARY CLIMATE SUMMARY FOR APRIL-MAY 2014 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO 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

4/1  48/31/40/-1/0.00/0.0/694/91          29 NNE AERO N/A        RMY N/A
4/2  56/34/45/+4/0.00/0.0/452/59          22 WSW AERO 20 MPH WSW RMY N/A
4/3  55/36/46/+4/0.00/0.0/707/92          23 NNW AERO 22 MPH NW  RMY 25
4/4  47/35/41/-1/0.31/0.0/255/33          26 ESE AERO N/A        RMY 25
4/5  51/33/42/-1/0.19/0.0/186/24          39 WNW AERO N/A        RMY 40
4/6  58/29/44/+1/0.00/0.0/755/97          25 W   AERO N/A        RMY N/A
4/7  59/44/52/+9/0.05/0.0/187/24          28 SSE AERO N/A        RMY N/A
4/8  62/41/52/+8/0.61/0.0/016/02          45 W   AERO N/A        RMY 44
4/9  60/36/48/+4/0.00/0.0/707/90          35 NW  AERO N/A        RMY 36
4/10 57/33/45/0/0.00/0.0/742/94           38 S   AERO N/A        RMY 39
4/11 70/45/58/+13/T/0.0/111/14            32 S   AERO N/A        RMY N/A
4/12 68/44/56/+11/0.00/0.0/699/88         28 W   AERO N/A        RMY 28
4/13 65/45/55/+10/0.04/0.0/215/27         35 S   AERO N/A        RMY N/A
4/14 73/55/64/+18/0.00/0.0/296/37         55 SW  AERO N/A        RMY 62
4/15 66/38/52/+5/1.22/0.0/000/00          62 S   AERO N/A        RMY 68
4/16 43/28/36/-11/0.43/0.8/757/94         39 NNW AERO N/A        RMY 39
4/17 39/29/34/-13/T/T/566/70              35 NE  AERO N/A        RMY 34
4/18 42/28/35/-13/0.00/0.0/016/02         25 E   AERO N/A        RMY 25
4/19 62/35/49/1/0.00/0.0/732/90           31 NW  AERO N/A        RMY 32
4/20 52/36/44/-5/0.00/0.0/783/96          21 E   AERO N/A        RMY 22
4/21 67/36/52/+3/0.00/0.0/778/95          25 SSW AERO N/A        RMY 26
4/22 72/44/58/+9/0.07/0.0/427/52          32 S   AERO N/A        RMY 33
4/23 52/43/48/-2/0.27/0.0/0/0             47 NW  AERO N/A        RMY 47 TSTM
4/24 56/38/47/-3/0.00/0.0/810/98          52 NW  AERO N/A        RMY 54
4/25 64/39/52/+2/0.00/0.0/721/87          25 S   AERO N/A        RMY 25
4/26 44/39/42/-9/…./0.0/0/0             18 E   AERO N/A        RMY 18
4/27 46/38/42/-9/…./0.0/8/1             21 NW  AERO N/A        RMY 23
4/28 56/36/46/-6/T/0.0/326/39             31 ENE AERO N/A        RMY 33
4/29 42/38/40/-12/T/0.0/0/0               32 ENE AERO N/A        RMY 35
4/30 44/38/41/-11/0.37/0.0/0/0            25 ESE AERO N/A        RMY N/A

5/1  64/43/54/+1/0.49/0.0/…/..          32 SSE RMY 36
5/2  68/51/60/+7/T/0.0/…/..             28 W   RMY 29
5/3  66/48/57/+4/…./0.0/…/..          21 SW  RMY N/A

5/4 morning low temp: 49F; the normal low is now 44F

DAILY RECORDS FOR APRIL 2014
4/14 – Minimum temperature of 55F EQUALS RECORD HIGH
MINIMUM FOR THIS DATE SET IN 1909.

DAILY RECORDS FOR MAY 2014
None so far.

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

RECORDS FOR MAY 4
HIGH 90F IN 2001
LOW 27F IN 1911 (RECORD FOR MAY)
PRECIP 1.92 INCHES IN 1893
SNOWFALL 0.1 INCHES IN 1920
PEAK GUST 60 MPH NW IN 1966

RECORDS FOR MAY 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976

TODAY’S REPORT PREPARED BY: Jonathan O’Brien