Saturday, May 26, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, MAY 26, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

ANOTHER UNSEASONABLY WARM DAY AT BLUE HILL

Summer-like temperatures have continued across the region today. We have reached
a high of 87F so far, one degree above yesterday’s high. This morning’s low of
67F would break the record high minimum for today’s date of 66F set in 2007,
but we will likely fall below that level before midnight. Considerable cloud
cover has been observed today, primarily in the form of mid to high level
clouds, which has still allowed some sunshine to filter through. Winds have
been steady from the west at 10-15mph after a breezy day yesterday which saw a
gust to 40mph.  Hazy conditions have been present today, with the visibility
running mostly between 30-40 miles.

May 2018 is on pace to be one of the warmest May’s on record at Blue Hill
with a mean temperature through the 25th of more than 60F. It also has a
chance to become just the fifth May on record to have a monthly average
temperature of 60F or greater.

Blue Hill Observatory Warmest May Mean Temperature (°F), 1885-2017

1. 61.5 in 2015
2. 61.4 in 1991
3. 61.0 in 1944
4. 60.9 in 2010
5. 59.4 in 1911
59.4 in 1959
7. 59.3 in 1964
59.3 in 2012

Today’s Observations:

7 A.M.
Weather: Scattered cirrus, few altocumulus WSW-NE, few altocumulus
castellanus N
Temperature: 73F; Dew Point: 61F; Wind: WSW at 10 kts
Sea-level pressure: 29.78 ins. Hg, rising
Visibility: 25 miles, hazy
6-hr Max temp: 73F
6-hr Min temp: 67F
24-hr Precip: 0.00 ins.
BHO SA 1155 250 SCT 25 084/73/61/2410/978/ FEW AC WSW-NE FEW ACC N HAZY/
8/081 52010 10073 20067

10 A.M.
Weather: Broken cirrostratus, broken cirrus, few altocumulus E-SE and SW-NNE
Temperature: 80F; Dew Point: 57F; Wind: W at 11G18 kts
Sea-level pressure: 29.79 ins. Hg, rising slightly
Visibility: 35 miles, distant haze
3-hr Precip: 0.00 ins.
BHO SA 1455 E200 BKN 250 BKN 35 089/80/57/2611G18/979/
FEW AC E-SE AND SW-NNE DSNT HZ/ 8/036 53005

1 P.M.
Weather: Broken altostratus, broken cirrus, few cumulus distant SSE-S
Temperature: 87F; Dew Point: 56F; Wind: W at 7 kts
Sea-level pressure: 29.78 ins. Hg, falling slightly
Visibility: 40 miles, distant haze
6-hr Max temp: 87F
6-hr Min temp: 73F
6-hr precip:  0.00 ins.
BHO SA 1755 E170 BKN 250 BKN 40 085/87/56/2707/978/ FEW CU SSE-S DSNT HZ/
8/171 56004 10087 20073

SUMMARY FOR FRIDAY, MAY 25, 2018

TEMPERATURE (DEGREES F)
MAX…..86   NORMAL…..69
MIN…..50   NORMAL…..51
MEAN….68   NORMAL…..60

DEPARTURE FROM 30-YEAR NORMAL…………………….+8
TOTAL DEPARTURE FOR THE MONTH…………………..+128 [+4.9 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..0   DEPARTURE………..-6
TOTAL HEATING UNITS FOR THE MONTH…………132   DEPARTURE………-102
TOTAL HEATING UNITS FOR THE SEASON……….5825   DEPARTURE………-444
TOTAL HEATING UNITS LAST SEASON TO DATE…..5607   DIFFERENCE……..+218

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………3   DEPARTURE……….+2
TOTAL COOLING UNITS FOR THE MONTH…………..42   DEPARTURE………+28
TOTAL COOLING UNITS FOR THE SEASON………….42   DEPARTURE………+26
TOTAL COOLING UNITS LAST SEASON TO DATE……..56   DEPARTURE………-14

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….40  W  AT 11:54 A.M.
AERO……………………39  W  AT 11:54 A.M.
ASOS……………………42  W  AT 11:54 A.M.
DAVIS…………………..41  M  AT 11:52 A.M.** RMY 43
FASTEST MILE FOR YESTERDAY…………………28  W  AT 11:55 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………28  W  AT 11:55 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..26  M  AT  2:23 P.M.**
AVERAGE WIND SPEED AND DIRECTION…………..16.9 W
ASOS…………………..16.3
DAVIS………………….15.9
** Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.16
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….1.88  DEPARTURE……-1.33
ASOS…………..1.85
TOTAL PRECIPITATION FOR THE YEAR……….27.19  DEPARTURE……+5.61
ASOS………….28.77

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 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/-1/0.00/0.0/625/74    25 WNW AERO 21 WNW RMY 25
5/02 88/59/74/+21/0.00/0.0/584/69   37 WSW AERO 29 WSW RMY 35
5/03 90/67/79/+26/0.13/0.0/433/51   36 SW  AERO 32 WSW RMY 36
5/04 84/67/74/+20/0.05/0.0/102/12   39 SSW AERO 37 SSW RMY N/A
5/05 73/54/64/+10/0.00/0.0/615/72   56 W   AERO 55 W   RMY N/A
5/06 65/48/57/+3/0.21/0.0/000/00    24 NE  AERO 18 NE  RMY 21
5/07 62/49/56/+1/0.00/0.0/713/83    26 ENE AERO 22 NE  RMY 24
5/08 73/46/60/+5/0.00/0.0/852/99    25 SSE AERO 21 ESE RMY 23
5/09 74/48/61/+6/0.00/0.0/768/89    23 ESE AERO 18 ESE RMY 21
5/10 73/48/61/+6/0.03/0.0/355/41    33 S   AERO 30 S   RMY 32
5/11 70/51/61/+5/0.00/0.0/703/81    26 WNW AERO 24 NW  RMY 28
5/12 51/47/49/-7/0.19/0.0/000/00    25 E   AERO 23 E   RMY N/A
5/13 58/46/52/-4/T/0.0/392/45       20 S   AERO 17 S   RMY 16
5/14 73/47/60/+3/T/0.0/557/63       23 S   AERO 18 S   RMY 21
5/15 83/54/69/+12/0.74/0.0/333/38   51 NW  AERO 50 NW  RMY 54 TSTM
5/16 56/49/53/-4/T/0.0/…/..       32 ENE AERO 28 ENE RMY 30
5/17 72/51/62/+5/0.02/0.0/…/..    17 SW  AERO 14 SW  RMY N/A
5/18 62/43/53/-5/0.00/0.0/…/..    35 ENE AERO 33 ENE RMY N/A
5/19 57/43/50/-8/…/0.0/…/..     22 E   AERO 17 E   RMY N/A
5/20 77/54/66/+8/…/0.0/…/..     33 SW  AERO 31 SW  RMY 33 TSTM
5/21 75/52/64/+5/0.00/0.0/…/..    22 W   AERO 18 W   RMY 20
5/22 68/51/60/+1/0.04/0.0/…/..    23 SSW AERO 21 S   RMY 22
5/23 82/51/67/+8/0.06/0.0/…/..    33 NNW AERO 33 NNW RMY 34 TSTM
5/24 74/50/62/+3/0.00/0.0/…/..    28 SSW AERO 25 SSW RMY 27
5/25 86/50/68/+8/0.00/0.0/…/..    40 W   AERO 39 W   RMY 43

5/26 Low temp since midnight is 67F; normal low is now 51F

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 26
HIGH 94F IN 2010
LOW 37F IN 1972,2013
PRECIP 1.73 INS IN 2003
SNOWFALL TRACE IN 1967 (Fell as ice pellets in nor’easter)
PEAK GUST 62 MPH NE IN 1967

RECORDS FOR MAY 27
HIGH 92F IN 1914
LOW 36F IN 1915
PRECIP 1.40 INS IN 1898
PEAK GUST 55 S IN 1956

TODAY’S REPORT PREPARED BY: Jonathan O’Brien