Sunday, May 3, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 3, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPERATURE REACHES 70F FOR FIRST TIME IN 2015
TIES FOR 8TH LATEST FIRST OCCURRENCE WITH
MAY 3, 1937 AND MAY 3, 1904…
AFTER A VERT COLD START AT 35F YESTERDAY
WE HAVE A NORMAL LOW OF 44F THIS MORNING

The thermometer hit 70 degrees early this afternoon
at 1:02 P.M. EDT for the first time 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. (see listing below)

So, after a normally cold start of 44F this morning
temperatures have soared well above the normal high
for this date of 63 degrees under bright sunshine
and a second consecutive day of light winds.

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
11) 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: Overcast altocumulus, numerous breaks in overcast
Temperature: 50F; Dew Point: 40F; Wind: WSW at 6 kts,
Sea-level pressure: 30.06 ins. Hg, rising then more quickly
Visibility: 60 miles, except 70 miles NW, light distant haze
6-hr Max temp: 50F
6-hr Min temp: 44F
24-hr precip: 0.00
BHO SA 1155 E100 BKN 60 180/50/40/2406/006/ NMRS BINOVC ALQDS
VSBY NW 70 LGT DSNT HZ ALQDS/ 8/030 53016 10050 20044

10 A.M.
Weather: Scattered altocumulus/altocumulus castellanus/floccus,
E-SSW, few small cumulus forming distant WNW-NW
Temperature: 60F; Dew Point: 41F; Wind: SSE at 5 kts,
Wind: Light
Sea-level pressure: 30.08 ins. Hg, rising then more slowly
Visibility: 60 miles, light distant haze increasing
BHO SA 1455 110 SCT 60 186/60/41/1505/008/ FEW SML CU FRMG
DSNT WNW-NW AC/ACC E-SSW LGT DSNT HZ INCRSNG WND LGT/
8/180 51006

1 P.M.
Weather: Clear, cumulus, few moderate mostly distant SW-N,
altocumulus/altocumulus lenticularis mostly distant SW-NW,
few cirrus SSE
Temperature: 72F; Dew Point: 39F; Wind: S at 8 kts,
Sea-level pressure: 30.07 ins. Hg, falling slightly
Visibility: 55 miles, distant haze
6-hr Max temp: 73F
6-hr Min temp: 50F
BHO SA 1755 CLR 55 184/72/39/1908/007/ CU/FEW MDT CU MSTLY
DSNT SW-N AC/ACSL MSTLY DSNT SW-NW FEW CI SSE DSNT HZ/
8/241 58002 10073 20050

SUMMARY FOR SATURDAY, MAY 2, 2015

TEMPERATURE (DEGREES F)
MAX…..63   NORMAL…..62
MIN…..35   NORMAL…..44
MEAN….49   NORMAL…..53

DEPARTURE FROM 30-YEAR NORMAL…………………..-4
TOTAL DEPARTURE FOR THE MONTH………………….-12 [-6.2 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..16  DEPARTURE………..+4
TOTAL HEATING UNITS FOR THE MONTH…………..36  DEPARTURE……….+11
TOTAL HEATING UNITS FOR THE SEASON………..6307  DEPARTURE………+247
TOTAL HEATING UNITS LAST SEASON TO DATE……6187  DIFFERENCE……..+120

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………20 S     AT   8:15 P.M.
ASOS…………………..20 S     AT   8:15 P.M.
DAVIS………………….19 S     AT   8:15 P.M. RMY 20
FASTEST MILE FOR YESTERDAY………………..15 S     AT   8:10 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..16 S     AT   8:11 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….15 S     AT   8:11 P.M.
AVERAGE WIND SPEED AND DIRECTION………….6.4 ENE
ASOS………………….7.1
DAVIS…………………5.5 ESE [110 degrees] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.12
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.00  DEPARTURE…..-0.24
ASOS……………0.00
TOTAL PRECIPITATION FOR THE YEAR………..17.92  DEPARTURE…..-0.74
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
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
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 ow since midnight is 44F; 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 3
HIGH 92F IN 2001
LOW 31F IN 1888
PRECIP 2.25 INS IN 1900
SNOWFALL TRACE IN 1908, 1985
PEAK GUST 71 MPH W IN 2002

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

TODAY’S REPORT PREPARED BY: Robert Skilling