Sunday, May 29, 2016

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, MAY 29, 2016
ALL TIMES ARE IN EASTERN STANDARD TIME

BACK-DOOR COLD FRONT BRINGS MUCH, MUCH COOLER
WEATHER TODAY FROM THE 90’S TO THE 60’S

After 90-degree heat which broke a record yesterday
a “back-door” cold front passed over the Blue Hill shortly
after 3 A.M. EDT this morning accompanied by a wind shift
from SSW-W to NNE.  The temperature fell from the low
70’s very early today to the upper 50’s by around dawn
this morning. We were only in the low 60’s by noon today
under a low stratus overcast with northeast winds.

RECORD HEAT AT OBSERVATORY ON SATURDAY, 28 MAY 2016
NEW RECORD HIGH MAXIMUM OF 92 DEGREES;
MINIMUM OF 63F (CORRECTED) FELL ONE SHORT OF RECORD

The maximum temperature as recorded in the official Hazen
temperature shelter was 92.2F at 3:15 P.M. EDT. This surpasses
the previous record of 90F set on 28 May 1929.

**The minimum temperature of 63F occurred in the early
morning hours yesterday but fell one degree short of the
record high minimum of 64F set in 1914.

Today’s Observations:

7 A.M.
Weather: Overcast stratus, thin fog
Temperature: 59F; Dew Point: 56F; Wind: N at 4 kts,
Wind: Light
Sea-level pressure: 30.20 ins. Hg, rising, then more slowly
Visibility: 4 miles, thin fog
6-hr Max temp: 71F
6-hr Min temp: 58F
24-hr precip: none
BHO SA 1155 E4 OVC 4F 226/59/56/3604/020/ WND LGT/ 8/6//
51018 10071 20058

10 A.M.
Weather: Overcast stratus, bright spots in the overcast,
sun occasionally dimly visible, thin fog
Temperature: 61F; Dew Point: 56F; Wind: NE at 8 kts,
Wind: Direction variable, N-E
Sea-level pressure: 30.21 ins. Hg, rising slightly
Visibility: 5 miles, thin fog, except 4 miles E, 8 miles SW
BHO SA 1455 E6 OVC 5F 231/61/56/0508/021/ BRGHT SPTS IOVC SUN OCNL DMLY
VSB VSBY E 4 SW 8 WND 35V09/ 8/6// 51005

1 P.M.
Weather: Bright overcast stratus, sun dimly visible,
thn fog and hazy
Temperature: 62F; Dew Point: 55F; Wind: NE at 8 kts
Sea-level pressure: 30.21 ins. Hg, falling slightly
Visibility: 30 miles, hazy
6-hr Max temp: 63F
6-hr Min temp: 59F
BHO SA 1755 E12 OVC 8 229/62/55/0508/021/ OVC BRGHT SUN DMLY VSB
VSBY NE-SE 6 THN F HAZY ALQDS WND 01V09/ 8/6// 58002 10063 20059

SUMMARY FOR SATURDAY,  MAY 28, 2016

TEMPERATURE (DEGREES F)
MAX…..92*  NORMAL…..70
MIN…..63   NORMAL…..51
MEAN….78   NORMAL…..61

DEPARTURE FROM 30-YEAR NORMAL…………………….+17
TOTAL DEPARTURE FOR THE MONTH…………………….+16 [+0.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0   DEPARTURE……….-6
TOTAL HEATING UNITS FOR THE MONTH………….250   DEPARTURE……….-2
TOTAL HEATING UNITS FOR THE SEASON………..5242   DEPARTURE…….-1045
TOTAL HEATING UNITS LAST SEASON TO DATE……6401   DIFFERENCE……-1159

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….22 SSW  AT  1:57 A.M. *
ASOS……………………23 SSW  AT  1:58 A.M.
DAVIS…………………..22 SSW  AT  1:51 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………16 SSW  AT  1:48 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18 SSW  AT  2:11 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..17 S    AT  1:50 A.M.
AVERAGE WIND SPEED AND DIRECTION………….11.0 SW
ASOS………………….11.1
DAVIS…………………10.0 SW [215 Deg.] * Last of several occurrences

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.15
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….2.26  DEPARTURE……-1.40
ASOS…………..2.09
TOTAL PRECIPITATION FOR THE YEAR……….19.20  DEPARTURE……-3.01
ASOS………….19.51

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE MONTH…………..TRACE  DEPARTURE……..0.0
TOTAL SNOWFALL FOR THE SEASON…………..57.5  DEPARTURE…….-5.7

PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

5/1 52/39/46/-7/0.08/T/000/00               21 S   AERO 22 SE  RMY 20
5/2 50/41/46/-7/0.31/0.0/000/00             20 NE  AERO 21 NE  RMY 18
5/3 48/43/46/-7/0.16/0.0/000/00             16 E   AERO 16 E   RMY 17
5/4 48/41/45/-9/0.53/0.0/000/00             33 NE  AERO 35 NE  RMY 34
5/5 44/41/43/-11/0.30/0.0/000/00            39 NNE AERO 41 NNE RMY 39
5/6 54/43/49/-5/0.13/0.0/360/42             28 ENE AERO 29 N   RMY 26
5/7 51/43/47/-8/…/0.0/000/00              25 NE  AERO 25 NE  RMY 23
5/8 60/46/53/-2/…/0.0/284/33              47 W   AERO 53 W   RMY 49
5/9 65/43/54/-1/0.00/0.0/743/86             40 W   AERO 44 W   RMY 40
5/10 69/40/55/0/0.00/0.0/806/93             22 W   AERO 25 WNW RMY 22
5/11 76/50/63/+7/0.00/0.0/808/93            22 WNW AERO 23 WNW*RMY 22
5/12 75/54/65/+9/0.00/0.0/819/94            23 NNE AERO 25 S   RMY 23
5/13 74/52/63/+7/0.21/0.0/079/09            27 S   AERO 27 S   RMY 26
5/14 78/54/66/+9/0.00/0.0/656/75            35 SSW*AERO 40 SSW RMY 37
5/15 60/41/51/-6/0.00/0.0/588/67            50 W   AERO 54 W   RMY 49
5/16 58/38/48/-9/0.00/0.0/800/91            45 W*  AERO 51 WNW RMY 49
5/17 69/47/58/+1/0.00/0.0/344/39            32 W   AERO 38 W   RMY 38
5/18 64/48/56/-2/0.00/0.0/804/91            24 NE  AERO 26 NNW RMY N/A
5/19 66/49/58/0/0.26/0.0/…/..             23 WNW AERO 26 WNW RMY 25
5/20 73/46/60/+2/0.00/0.0/…/..            20 SSE AERO 22 SSE RMY 21
5/21 74/53/64/+5/0.00.0.0/…/..            21 S   AERO 23 S   RMY 21
5/22 64/53/59/0/T/0.0/…/..                26 ENE AERO 29 ENE RMY 26
5/23 74/51/63/+4/T/0.0/…/..               22 ENE AERO 31 ENE RMY N/A
5/24 56/50/53/-6/…/0.0/…/..             30 ENE AERO 31 ENE RMY 29
5/25 86/51/69/+9/…/0.0/…/..             25 W   AERO 28 W   RMY 25
5/26 86/64/75/+15/0.00/0.0/…/..           21 SE  AERO 23 SE  RMY 21
5/27 81/60/71/+11/0.00/0.0/…/..           26 S   AERO 30 S   RMY 29
5/28 92*/63/78/+17/0.00/0.0/…/..          22 SSW AERO 22 SSW RMY N/A

5/29 low temp since midnight is 58F; normal low now 52F

* Last of several occurrences
* All sunshine data corrected to astronomical minutes.

DAILY RECORDS FOR MAY 2016

5/1/16: DAILY RECORD SNOWFALL OF A TRACE,
TIES PREVIOUS RECORDS SET IN 1905, 1917, 1921, and 1995
5/28/16: NEW HIGH DAILY RECORD MAXIMUM TEMP. OF 92F;
PREVIOUS RECORD 90F IN 1914

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

RECORDS FOR MAY 29
HIGH 93F IN 1919
LOW 35F IN 1902
PRECIP 1.63 INS 1990
PEAK GUST 55e MPH NNW IN 1943, WNW IN 1945

RECORDS FOR MAY 30
HIGH 93F IN 1929
LOW 39F IN 1949,1961
PRECIP 1.47 INS 1948
PEAK GUST 61e MPH NW IN 1945

TODAY’S REPORT PREPARED BY: Robert Skilling