Tuesday, May 23, 2017

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 23, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

SKIES CLEAR AFTER FOGGY MORNING

Additional precip. from yesterday evening and this morning
measured 0.10 in. at 7:00AM EST.  This brings the monthly
total to 3.35 in and monthly departure to +0.60 in. As
morning fog cleared, it limited visibility to 10-20 miles
at the 7:00AM ob.  Clearing continued to give us mostly
cloudy skies with high cirrus clouds and visibility of
70 miles for the rest of the day.  Middle altocumulus
clouds moved in by the afternoon.

Temperatures were almost 20F warmer today.  Temps. dropped
back down to 49F last evening and had warmed to 51F by
midnight.  The temp. at 1:00PM was 70F.  Winds have been
light again tonight and predominantly out of the northwest.

Today’s Observations:

7 A.M.
Weather: Scattered stratus fractus, broken cirrus
Temperature: 52F; Dew Point: 51F; Wind: NW at 6 kts,
Wind speed: Light
Sea-level pressure: 29.95 ins. Hg, rising then falling
Visibility: 20 miles, except 10 miles NNW-SE, distant fog
in all directions
6-hr Max temp: 52F
6-hr Min temp: 51F
24-hr precip: 0.10 in.
BHO SA 1155 2 SCT E250 BKN 20 141/52/51/3106/995/ VSBY NNW-SE 10
DSNT FG ALQDS WND LGT/ 8/701 50003 MANUAL 70010 ASOS 70011 10052
20051

10 A.M.
Weather: Few cumulus W-S, broken cirrus
Temperature: 63F; Dew Point: 48F; Wind: N at 8G14 kts
Sea-level pressure: 29.93 ins. Hg, rising then falling
Visibility: 70 miles
BHO SA 1455 E250 BKN 70 137/63/48/3608G14/993/ FEW CU W-S/ 8/104
58004

1 P.M.
Weather: Scattered altocumulus, broken cirrostratus
Temperature: 70F; Dew Point: 48F; Wind: NW at 8 kts
Sea-level pressure: 29.88 ins. Hg, falling then more quickly
Visibility: 70 miles
6-hr Max temp: 70F
6-hr Min temp: 52F
BHO SA 1755 160 SCT E200 BKN 70 120/70/48/3108/988/ 8/036 58017
10070 20052

SUMMARY FOR MONDAY, MAY 22, 2017

TEMPERATURE (DEGREES F)
MAX…..53   NORMAL…..68
MIN…..48   NORMAL…..50
MEAN….51   NORMAL…..59

DEPARTURE FROM 30-YEAR NORMAL…………………….-8
TOTAL DEPARTURE FOR THE MONTH……………………-13 [-0.8 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..14   DEPARTURE……….+7
TOTAL HEATING UNITS FOR THE MONTH………….250   DEPARTURE………+35
TOTAL HEATING UNITS FOR THE SEASON………..5583   DEPARTURE……..-667
TOTAL HEATING UNITS LAST SEASON TO DATE……5228   DIFFERENCE…….+355

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….22  S  AT  3:32 P.M.
AERO……………………22  S  AT  3:38 P.M.
ASOS……………………23  S  AT  3:32 P.M.
DAVIS…………………..22  S  AT  3:38 P.M. RMY 23
FASTEST MILE FOR YESTERDAY…………………16  S  AT  3:33 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………17  S  AT  3:39 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..15 SSW AT 11:53 A.M.
AVERAGE WIND SPEED AND DIRECTION…………..8.7 SSE
ASOS…………………..8.8
DAVIS………………….7.4 S [175 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.10  DEPARTURE……-0.04
ASOS…………..0.11
TOTAL PRECIPITATION FOR THE MONTH……….3.35  DEPARTURE……+0.60
ASOS…………..3.44
TOTAL PRECIPITATION FOR THE YEAR……….24.16  DEPARTURE……+2.86
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

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
M:    Missing data

5/1  50/43/47/-6/T/034/04                  21 N   AERO 18 N   RMY 22
5/2  65/42/54/+1/0.26/136/16               41 W   AERO 44 W   RMY 43
5/3  52/42/53/0/0.00/595/70                37 WNW*AERO 39 WNW RMY 40
5/4  65/40/53/-1/0.00/724/85               23 S   AERO 23 S   RMY 24
5/5  51/44/48/-6/0.73/000/00               28 E   AERO 28 E   RMY N/A
5/6  65/50/58/+4/0.23/094/11               46 SSE AERO 48 SSE RMY 49
5/7  63/47/55/0/T/670/78                   35 S   AERO 38 S   RMY 39
5/8  54/38/46/-9/T/224/26                  29 WSW AERO 29 WSW RMY 32
5/9  53/36/45/-10/T/251/29                 20 ESE AERO 17 ESE RMY 19
5/10 57/42/50/-5/0.00/225/26               17 NNE AERO 16 NW  RMY N/A
5/11 58/45/52/-4/0.00/443/51               23 NE* AERO 23 NE  RMY 23
5/12 57/41/49/-7/0.01/453/52               21 NE  AERO 20 NE  RMY 19
5/13 57/41/49/-7/0.19/009/01               24 ENE AERO 24 E   RMY N/A
5/14 47/43/45/-12/1.49/000/00              33 NNE AERO 36 N   RMY 36
5/15 58/43/51/-6/0.24/018/02               36 NNW AERO 40 NNW RMY 41
5/16 79/51/65/+8/0.00/870/99               26 WNW AREO 26 WNW RMY 29
5/17 90/60/75/+18/T/775/88                 32 SSE AERO 33 SW* RMY 34
5/18 96/69/83/+25/0.01/830/94              39 WNW AERO 41 WNW RMY 42 TSTM
5/19 89/56/73/+15/T/832/94                 35 W   AERO 33 W   RMY 37
5/20 67/49/58/0/0.00/…/..                23 NE  AERO 22 NE  RMY 21
5/21 66/45/56/-3/0.00/…/..               21 E   AERO 20 S   RMY 21
5/22 53/48/51/-8/…./…/..               22 S   AERO 22 S   RMY 23

5/23 Low temp since midnight is 51F; normal low is now 50F

DAILY RECORDS FOR MAY

5/17/17: DAILY RECORD MAXIMUM TEMPERATURE OF 90F,
BREAKS PREVIOUS RECORD OF 88F SET IN 1974
AND TIED IN 1977

5/17/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 60F,
TIES PREVIOUS RECORD SET IN 1932

5/18/17: DAILY RECORD MAXIMUM TEMPERATURE OF 96F,
BREAKS PREVIOUS RECORD OF 88F SET IN 1906
AND TIED IN 1936 AND 1986;
BREAKS PREVIOUS MONTHLY RECORD OF 94F SET ON
MAY 26, 2010

5/18/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 69F,
BREAKS PREVIOUS RECORD OF 61F SET IN 1943

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

RECORDS FOR MAY 23
HIGH 92F IN 1964,1992
LOW 38F IN 1976
PRECIP 0.97 INS IN 1979
PEAK GUST 49e MPH W IN 1945

RECORDS FOR MAY 24
HIGH 92F IN 1964
LOW 35F IN 1956
PRECIP 2.13 INS IN 1951
PEAK GUST 54 MPH NNE IN 2005

TODAY’S REPORT PREPARED BY: Cecilia Borries-Strigle