Thursday, May 10, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MAY 10, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

FOG CLEARS AND REVEALS ANOTHER PLEASANT DAY ON
TOP OF GREAT BLUE HILL…

The morning began with dense fog on top of Great
Blue Hill that left visibility down to 1/2 mile.
Very light precipitation ended right after the
7:00 A.M observation and a total of 0.03 ins of
rainfall was measured this morning. The fog
dissipated mid-morning allowing for mostly sunny
skies and 40 miles of visibility by 1:00 P.M.
So far temperatures continue to be slightly above
seasonable with a high of 72F by 1:00 P.M. This is
7 degrees above the daily normal of 65F. Wind today
was once again light and variable in the morning
and gustier in the afternoon eventually settling
from the south.

PRELIMINARY STATS FOR APRIL 2018

TEMPERATURE, Deg. F
Avg. Max. 52.4 [-3.3] Avg. Min. 34.9 [-2.8] Mean      43.7 [-3.0] 24-hour corrected mean: 43.1
Max. for month:  73F on 28th
Min. for month:  24F on  9th

HEATING DEGREE DAYS
Total heating units:    635  [+84] Total for the season:  5693 [-342] Total for last season: 5333

PRECIPITATION, Inches
Total: 6.51 [+1.96] Greatest in 24 hrs: 2.85 on the 15-16th

SNOWFALL, Inches
Total: 2.6 [-0.4] Greatest in 24 hrs: 1.6 in. on 2nd

WIND, mph
Avg. uncorrected wind speed: 12.2
Avg. corrected wind speed: 12.6
Prevailing wind direction: WNW at 16%
Peak gust and direction: 56 NW on the 4th

SUNSHINE:
Campbell-Stokes card minutes: 9744 minutes of possible 23250 or 42%
Astronomical total minutes:  10085 minutes of possible 24105 or 42%

Today’s Observations:

7 A.M.
Weather: Very light drizzle and fog
Temperature: 49F; Dew Point: 49F; Wind: NNW at 3 kts,
Wind: Light and variable, direction estimated
Sea-level pressure: 30.04 ins. Hg, falling, then more rapidly
Visibility: 1/2 mile
6-hr Max temp: 49F
6-hr Min temp: 48F
24-hr precip:  0.03 ins.
BHO SA 1155 W3 X 1/2L-F 172/49/49/E3403/004/ PCPN VRY LGT
WND L/V/ 8//// 58008 MANUAL 70003 ASOS 70002 10049 20048

10 A.M.
Weather: Overcast stratus
Temperature: 54F; Dew Point: 50F; Wind: SSE at 3 kts,
Wind: Light and variable, direction estimated
Sea-level pressure: 29.98 ins. Hg, falling, then more rapidly
Visibility: 15 miles, except 5 miles E-NNW, distant fog in
all directions
3-hr precip: Trace
BHO SA 1455 E10 OVC 15 152/54/50/E1603/998/ VSBY E-NNW
5 DSNT FG ALQDS WND L/V/ 8/6// 58020 MANUAL 600//

1 P.M.
Weather: Scattered cirrostratus, few cumulus distant SSE-NNW
Temperature: 72F; Dew Point: 48F; Wind: ENE at 9G20 kts
Sea-level pressure: 29.89 ins. Hg, falling, then more slowly
Visibility: 40 miles, distant haze in all directions
6-hr Max temp: 72F
6-hr Min temp: 49F
6-hr precip:   Trace
BHO SA 1755 E250 SCT 40 121/72/48/2009G20/989/ FEW CU
SSE-NNW DSNT HZ ALQDS/ 8/106 58031 MANUAL 600// 10072 20049

SUMMARY FOR WEDNESDAY, MAY 9, 2018

TEMPERATURE (DEGREES F)
MAX…..74   NORMAL…..64
MIN…..48   NORMAL…..46
MEAN….61   NORMAL…..55

DEPARTURE FROM 30-YEAR NORMAL……………………..+6
TOTAL DEPARTURE FOR THE MONTH…………………….+91 [+9.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..4   DEPARTURE……….-6
TOTAL HEATING UNITS FOR THE MONTH………….40   DEPARTURE………-63
TOTAL HEATING UNITS FOR THE SEASON……….5733   DEPARTURE……..-405
TOTAL HEATING UNITS LAST SEASON TO DATE…..5459   DIFFERENCE…….+274

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE………..0
TOTAL COOLING UNITS FOR THE MONTH…………..32   DEPARTURE………+29
TOTAL COOLING UNITS FOR THE SEASON………….32   DEPARTURE………+27
TOTAL COOLING UNITS LAST SEASON TO DATE……..20   DEPARTURE………+12

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….23 ESE AT 2:52 P.M.*
AERO……………………18 ESE AT 2:52 P.M.
ASOS……………………22 ESE AT 2:52 P.M.
DAVIS…………………..21 M   AT 2:52 P.M.** RMY 23
FASTEST MILE FOR YESTERDAY…………………14 ESE AT 3:11 P.M.*
MAXIMUM 2-MINUTE ASOS AVERAGE………………16 ESE AT 3:11 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..16 M   AT 3:11 P.M.**
AVERAGE WIND SPEED AND DIRECTION…………..7.7 E
ASOS…………………..7.8
DAVIS………………….7.6 M**
*  Last of multiple occurrences
** Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.03  DEPARTURE……-0.08
ASOS…………..0.02
TOTAL PRECIPITATION FOR THE MONTH……….0.42  DEPARTURE……-0.68
ASOS…………..0.39
TOTAL PRECIPITATION FOR THE YEAR……….25.73  DEPARTURE……+6.26
ASOS………….27.31

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…………..92.8  DEPARTURE…….+30.0

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY 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
M   : Missing data
*   : Estimated data

4/01 58/33/46/+5/0.00/0.0/336/44   45 SSW AERO 43 SSW RMY N/A
4/02 38/30/34/-7/0.13/1.6/077/10   20 SSW AERO 15 SSW RMY 17
4/03 48/30/39/-3/0.54/0.0/238/31   28 SSE AERO 25 SSE RMY 25
4/04 54/36/45/+3/0.21/0.0/000/00   56 WNW AERO 56 WNW RMY 54
4/05 40/27/34/-9/0.00/0.0/760/98   53 WNW AERO 53 WNW RMY 52
4/06 41/25/33/-10/0.25/1.0/156/20  37 S   AERO 36 S   RMY 38
4/07 46/32/35/-4/0.00/0.0/312/40   32 WNW*AERO 35 WNW RMY 34
4/08 41/29/35/-9/0.00/0.0/290/37   35 WNW*AERO 31 WNW RMY 34
4/09 45/24/35/-9/0.00/0.0/715/01   28 WNW AERO 25 WNW RMY 29
4/10 39/31/35/-10/T/T/000/00       14 SSW AERO 13 SSW RMY N/A
4/11 48/29/39/-6/T/0.0/364/46      24 SSE AERO 23 SSE RMY 25
4/12 61/33/47/+2/0.03/0.0/500/63   39 SSW AERO 38 SSW RMY 41
4/13 65/47/56/+10/T/0.0/096/12     37 SSW AERO 37 SSW RMY N/A
4/14 51/36/44/-2/0.00/0.0/328/41   33 ENE AERO 31 ENE RMY N/A
4/15 36/30/33/-14/0.32/T/000/00    39 ENE AERO 39 ENE RMY N/A
4/16 55/32/44/-3/2.63/000/00       41 ENE AERO 43 ENE RMY 41
4/17 48/36/42/-5/0.00/0.0/210/26   37 W   AERO 33 W   RMY 37
4/18 53/32/43/-5/0.00/0.0/633/78   35 W   AERO 31 W   RMY 34
4/19 41/34/38/-10/0.22/T/000/00    28 WNW AERO 25 WNW RMY N/A
4/20 52/31/42/-7/0.00/0.0/522/64   34 NW  AERO 33 NW  RMY 36
4/21 60/33/47/-2/0.00/0.0/811/99   28 NW  AERO 26 NW  RMY 29
4/22 61/36/49/0/0.00/0.0/821/100   25 NW  AERO 24 NW  RMY 26
4/23 62/40/51/+1/0.00/0.0/816/99   25 S   AERO 25 S   RMY 26
4/24 67/39/53/+3/0.00/0.0/645/78   31 S   AERO 29 S   RMY 32
4/25 57/47/52/+2/0.94/0.0/000/00   32 SE  AERO 32 SE  RMY 33
4/26 66/48/57/+6/0.28/0.0/308/37   36 WNW AERO 35 WNW RMY 37
4/27 60/45/53/+2/0.55/0.0/192/23   18 W   AERO 15 W   RMY N/A
4/28 73/47/60/+8/0.00/0.0/711/85   25 S   AERO 21 S   RMY 25
4/29 59/38/49/-3/0.04/0.0/227/27   32 SW  AERO 26 SW  RMY 31
4/30 46/36/41/-11/0.37/0.0/017/02  23 WSW AERO 16 WSW RMY N/A

DAILY RECORDS FOR APRIL 2018

4/16/18: NEW DAILY RECORD MAXIMUM PRECIPITATION OF 2.63 INS.
PREVIOUS RECORD WAS 2.45 INS. SET IN 1929

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY 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
M:    Missing data

5/01 65/39/52/-1/0.00/0.0/…/..    25 WNW AERO 21 WNW RMY 25
5/02 88/59/74/+21/0.00/0.0/…/..   37 WSW AERO 29 WSW RMY 35
5/03 90/67/70/+26/…./0.0/…/..   36 SW  AERO 32 WSW RMY 36
5/04 84/67/74/+20/…./0.0/…/..   39 SSW AERO 37 SSW RMY N/A
5/05 73/54/64/+10/0.00/0.0/…/..   56 W   AERO 55 W   RMY N/A
5/06 65/48/57/+3/0.21/0.0/…/..    24 NE  AERO 18 NE  RMY 21
5/07 62/49/56/+1/0.00/0.0/…/..    26 ENE AERO 22 NE  RMY 24
5/08 73/46/60/+5/0.00/0.0/…/..    25 SSE AERO 21 ESE RMY 23
5/09 74/48/61/+6/…./0.0/…/..    23 ESE AERO 18 ESE RMY 21

5/10 Low temp since midnight is 48F; normal low is now 46F

DAILY RECORDS FOR MAY 2018

5/03/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 66F SET IN 2001

5/04/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 67F,
BREAKS PREVIOUS RECORD OF 66F SET IN 2001

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

RECORDS FOR MAY 10
HIGH 93F IN 1896
LOW 29F  IN 1900
PRE 1.85 INS IN 1998
SNOW 2.8 INS 1977 (7.8 INS TOTAL 5/9-5/10 1977)
PEAK GUST 64 MPH S IN 1990

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

TODAY’S REPORT PREPARED BY: K. Geagan