Monday, May 4, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 4, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURES SKY-ROCKET MID MORNING, REACHING
83F BY 1:00 PM EST

Mostly clear, but hazy skies, have kept visibility
reduced to 40 miles in all directions. Dry
conditions, low humidity and a steady S-SSW wind
have raised red flag warnings in the western portion
of the state, with fire weather danger being monitored
elsewhere in the region.

By the 1:00 PM EST observation skies were still hazy,
with some cumulus and stratocumulus covering 3/8 of
the sky. Relative humidity at the observation was
only 25 percent with a dew point of 43F.

The thermometer hit 74 degrees yesterday afternoon
for the first 70 degree occurrence this year. This
is the latest first occurrence of 70F since 1975
when it first occurred quite a bit later than today’s
date on May 11.

BHO Latest First 70-deg Temperature, (1885-2015)

1) 20 May, 1966
2) 19 May, 1917
3) 14 May, 1924
4) 11 May, 1975
5) 10 May, 1893
6) 7 May, 1971
7) 5 May, 1939
8) 3 May, 1937
3 May, 1904
3 May,  2015
10) 2 May, 1916
2 May, 1919

PRELIMINARY STATS FOR APRIL 2015

TEMPERATURE, Deg. F
Avg. Max. 55.9 [+0.2] Avg. Min. 38.4 [+0.7] Mean      47.2 [+0.5] Corrected mean: 46.7
Max. for month: 69 on 4/13
Min. for month: 26 on 4/1

HEATING DEGREE DAYS
Total heating units: 528 [-23] Total for the season: 6271 [+236] Total for last season: 6171

PRECIPITATION, Inches
Total: 3.33 [-1.22] Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: Trace [-3.0] Greatest in 24 hrs: Trace on 4/8

WIND, mph
Avg. uncorrected wind speed: 12.6
Avg. corrected wind speed: 13.0
Prevailing wind direction: NW @ 16%
Peak gust and direction: 54 NW on the 4th

SUNSHINE:
Astronomical total minutes:   12386 / 24083 or 51%
Campbell-Stokes card minutes: 11946 / 23250 or 51%

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant south
Temperature: 56F; Dew Point: 45F; Wind: SSW at 10 kts,
Sea-level pressure: 30.21 ins. Hg, rising then more slowly
Visibility: 40 miles, hazy
6-hr Max temp: 56F
6-hr Min temp: 47F
24-hr precip: 0.00
BHO SA 1155 CLR 40 231/56/45/2010/021/ FEW CI DSNT S HAZY/
8/001 51012 10056 20047

10 A.M.
Weather: Clear, few cumulus distant SSW-SW, few cirrus W and N-E
Temperature: 74F; Dew Point: 48F; Wind: S at 7 kts,
Sea-level pressure: 30.22 ins. Hg, rising steadily
Visibility: 40 miles, hazy
BHO SA 1455 CLR 40 234/74/48/1907/022/ FEW CU DSNT SSW-SW
FEW CI W AND N-E HAZY/ 8/101 52003

1 P.M.
Weather: Scattered cumulus/stratocumulus
Temperature: 82F; Dew Point: 43F; Wind: S at 13G22 kts,
Sea-level pressure: 30.16 ins. Hg, rising, then falling and lower
Visibility: 40 miles, hazy
6-hr Max temp: 83F
6-hr Min temp: 56F
BHO SA 1755 60 SCT 40 212/82/43/1813G22/016/ HAZY/ 8/500 58022
10083 20056

SUMMARY FOR SUNDAY, MAY 3, 2015

TEMPERATURE (DEGREES F)
MAX…..74   NORMAL…..63
MIN…..44   NORMAL…..44
MEAN….59   NORMAL…..53

DEPARTURE FROM 30-YEAR NORMAL…………………..+6
TOTAL DEPARTURE FOR THE MONTH…………………..-6 [-2.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………6  DEPARTURE………..-6
TOTAL HEATING UNITS FOR THE MONTH…………..42  DEPARTURE………..+5
TOTAL HEATING UNITS FOR THE SEASON………..6313  DEPARTURE………+241
TOTAL HEATING UNITS LAST SEASON TO DATE……6195  DIFFERENCE……..+118

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………22 S     AT   6:48 P.M.
ASOS…………………..23 S     AT  10:58 P.M.
DAVIS………………….21 S     AT   3:21 P.M. RMY 22
FASTEST MILE FOR YESTERDAY………………..18 S     AT   6:49 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..18 S     AT   9:44 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….17 S     AT   4:18 P.M.
AVERAGE WIND SPEED AND DIRECTION…………10.3 S
ASOS…………………11.0
DAVIS…………………9.3 SSW [198 degrees] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.13
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.00  DEPARTURE…..-0.37
ASOS……………0.00
TOTAL PRECIPITATION FOR THE YEAR………..17.92  DEPARTURE…..-0.87
ASOS…………….N/A ***
*** ASOS annual totals not available due to erroneous readings

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…………..150.8  DEPARTURE….+88.1

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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  44/26/35/-6/0.00/0.0/748/98              30 WNW RMY 31
4/2  59/29/44/+3/T/0.0/375/49                 39 SSW RMY 43
4/3  56/47/52/+10/0.02/0.0/000/00             36 SW  RMY N/A
4/4  49/32/41/-1/…./0.0/501/65              54 NW  RMY 64  TSTM
4/5  47/30/39/-4/…./0.0/464/60              40 W   RMY 45
4/6  48/33/41/-2/0/00/0.0/544/70              18 NE  RMY N/A
4/7  39/34/37/-6/…./0.0/000/00              21 NE  RMY N/A
4/8  41/32/37/-7/…./T/000/00                30 ENE RMY 32
4/9  35/32/34/-10/…./0.0/000/00             31 ENE RMY 32
4/10 53/35/44/-1/…./0.0/000/00              31 SW  RMY N/A
4/11 56/38/46/+1/0.00/0.0/744/94              39 WNW RMY 48
4/12 68/35/52/+7/0.00/0.0/762/96              23 WNW RMY 23
4/13 69/47/58/+12/0.00/0.0/764/96             35 SSW RMY N/A
4/14 65/51/58/+12/0.05/0.0/072/09             37 SSW RMY N/A
4/15 67/45/56/+9/0.00/0.0/786/98              32 NW  RMY 33
4/16 64/42/53/+6/0.00/0.0/765/95              31 S   RMY 21
4/17 64/45/55/+8/0.05/0.0/065/08              31 SSW RMY 32
4/18 64/43/54/+6/0.00/0.0/770/95              31 N   RMY 36
4/19 55/39/47/-1/0.00/0.0/724/89              25 NNW RMY N/A
4/20 55/38/47/-2/…./0.0/000/00              36 SE  RMY 40
4/21 67/51/59/+10/…./0.0/417/51             30 SSE RMY N/A TSTM
4/22 67/45/56/+7/0.03/0.0/632/77              44 SSW RMY 52
4/23 49/34/42/-8/0.00/0/0/362/44              32 W   RMY N/A
4/24 50/32/41/-9/0.00/0.0/562/68              32 NW  RMY 36
4/25 56/30/43/-7/0.00/0.0/638/77              26 NW  RMY 29
4/26 54/39/47/-4/0.00/0.0/258/31              17 NW  RMY N/A
4/27 56/42/49/-2/…./0.0/125/15              30 NW  RMY N/A
4/28 63/39/51/-1/…./0.0/527/63              32 NW  RMY 35
4/29 58/46/52/+0/T/0.0/461/55                 24 ENE RMY 22
4/30 60/42/51/-1/0.00/0.0/320/38              21 NE  RMY N/A

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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

5/1 52/37/45/-8/0.00/0.0/…/..               21 NE RMY 20
5/2 63/35/49/-4/0.00/0.0/…/..               20 S  RMY 20
5/3 74/44/59/+6/0.00/0.0/…/..               22 S  RMY 22

5/4 Low since midnight is 47F; normal low now 44F

DAILY RECORDS FOR MAY 2015

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: Brian Fitzgerald