Saturday, January 20, 2018

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, JANUARY 20, 2018
ALL TIMES ARE IN EASTERN STANDARD TIME

WARMER WEATHER TODAY WITH MOSTLY CLOUDY SKIES

Winds shifted from the west to the south-southwest late yesterday.
This has helped draw warmer air into the region last night and into
today. After a morning low of only 27F, we have climbed up to 44F
so far this afternoon, which is well above average. This comes
despite mostly cloudy skies for much of the day, with mid and high
level clouds covering much of the sky. Winds have been gusty today,
averaging 15-20mph, with the direction variable from southwest to
west. The peak gust for today so far is 39mph. Visibility today
has ranged from 30-45 miles. The warm weather has helped to melt
an already thin snow cover, with less than an inch of snow on the
ground on average this afternoon and areas of bare ground becoming
muddy.

Today’s Observations:

7 A.M.
Weather: Broken altocumulus, broken cirrus, few lower altocumulus
NW-E, few altocumulus lenticularis SE-S
Temperature: 33F; Dew Point: 23F; Wind: SSW at 16 kts
Sea-level pressure: 29.71 ins. Hg, falling, then steady
Visibility: 30 miles, distant haze
6-hr Max temp: 33F
6-hr Min temp: 29F
24-hr precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: 1 in.
BHO SA 1155 E140 BKN 250 BKN 30 060/33/23/2116/971/ FEW LWR AC NW-E
FEW ACSL SE-S DSNT HZ/ 8/041 4/001 56034 10033 20029

10 A.M.
Weather: Scattered altocumulus, broken cirrostratus, few lower
altocumulus
Temperature: 40F; Dew Point: 22F; Wind: SW at 16G24 kts,
Peak Wind: 27 kts (31 mph) SW at 9:38 A.M.
Sea-level pressure: 29.72 ins. Hg, rising slightly
Visibility: 45 miles, distant haze
3-hr precip: 0.00 ins.
3-hr snowfall: 0.0 ins.
BHO SA 1455 140 SCT E200 BKN 45 064/40/22/2316G24/972/ FEW LWR AC
DSNT HZ PK WND 2227/38/ 8/057 51004

1 P.M.
Weather: Scattered altocumulus, broken cirrostratus, broken cirrus,
few lower altocumulus
Temperature: 44F; Dew Point: 24F; Wind: WSW at 17G26 kts,
Peak Wind: 29 kts (33 mph) WSW at 12:18 P.M.
Sea-level pressure: 29.69 ins. Hg, rising then falling
Visibility: 45 miles, distant haze
6-hr precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
6-hr Max temp: 44F
6-hr Min temp: 33F
Snow depth: Trace
BHO SA 1755 140 SCT E200 BKN 250 BKN 45 053/44/24/2517G26/969/
EW LWR AC DSNT HZ PK WND 2529/18/ 8/057 58011 10044 20033

SUMMARY FOR FRIDAY, JANUARY 19, 2018

TEMPERATURE (DEGREES F)
MAX…..34   NORMAL…..33
MIN…..17   NORMAL…..17
MEAN….26   NORMAL…..25

DEPARTURE FROM 30-YEAR NORMAL………………………+1
TOTAL DEPARTURE FOR THE MONTH……………………..-62 [-3.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY………….39  DEPARTURE……….-1
TOTAL HEATING UNITS FOR THE MONTH…………811  DEPARTURE………+63
TOTAL HEATING UNITS FOR THE SEASON……….2933  DEPARTURE……..-119
TOTAL HEATING UNITS LAST SEASON TO DATE…..2672  DIFFERENCE…….+260

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….22  SSW  AT 11:59 P.M.
AERO……………………20  SSW  AT 11:59 P.M.
ASOS……………………21  SSW  AT 11:56 P.M.
DAVIS…………………..20  M    AT 11:03 P.M.* RMY N/A
FASTEST MILE FOR YESTERDAY…………………17  SSW  AT 11:59 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………17  SSW  AT 11:57 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..16  M    AT 11:57 P.M.*
AVERAGE WIND SPEED AND DIRECTION……………9.4 W
ASOS…………………..10.0
DAVIS…………………..8.5
*Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.00  DEPARTURE……-0.13
ASOS…………..0.00
TOTAL PRECIPITATION FOR THE MONTH……….4.19  DEPARTURE……+1.49
ASOS…………..4.63
TOTAL PRECIPITATION FOR THE YEAR………..4.19  DEPARTURE……+1.49
ASOS…………..4.63

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE……..-0.6
TOTAL SNOWFALL FOR THE MONTH……………19.3  DEPARTURE……..+8.6
TOTAL SNOWFALL FOR THE SEASON…………..28.6  DEPARTURE……..+1.9

PRELIMINARY CLIMATE SUMMARY FOR JANUARY 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

1/01 11/-5/3/-24/0.00/0.0/…/..        30 NW  AERO 30 NW  RMY 31
1/02 15/-2/7/-20/0.00/0.0/…/..        26 W   AERO 25 W   RMY 26
1/03 28/11/20/-6/0.00/0.0/…/..        23 WSW AERO 20 WSW RMY N/A
1/04 28/18/23/-3/1.66/16.5/000/00       54 NNW AERO 60 NNW RMY 64
1/05 18/2/10/-16/0.00/0.0/…/..        53 W   AERO 53 W   RMY 57
1/06 10/-2/4/-22/0.00/0.0/…/..        43 WSW AERO 47 WSW RMY 47
1/07 14/-8/3/-23/0.00/0.0/…/..        37 WNW AERO 35 WNW RMY N/A
1/08 33/14/24/-2/T/T/…/..             40 S   AERO 40 S   RMY 42
1/09 40/25/33/+7/T/T/…/..             37 W   AERO 35 W   RMY 33
1/10 36/20/28/+3/0.00/0.0/…/..        30 W   AERO 30 W   RMY N/A
1/11 50/32/41/+16/0.00/0.0/…/..       33 S   AERO 32 S   RMY 34
1/12 60/45/53/+28/…./0.0/…/..       56 S   AERO 56 S   RMY 55
1/13 60/17/39/+14/…./0.0/…/..       58 SSW AERO 60 SSW RMY 62
1/14 21/11/16/-9/0.00/0.0/…/..        30 NW  AERO 30 NW  RMY N/A
1/15 18/11/15/-10/…./…/…/..       23 NNW AERO 21 N   RMY 23
1/16 31/18/25/0/0.00/0.0/…/..         17 SSE AERO 15 SSE RMY N/A
1/17 32/29/31/+6/0.23/2.3/…/..        20 SE  AERO 17 SE  RMY N/A
1/18 29/16/23/-2/0.00/0.0/…/..        24 NW  AERO 23 NW  RMY 26
1/19 34/17/26/+1/0.00/0.0/…/..        22 SSW AERO 20 SSW RMY N/A

1/20 Low temp since midnight is 27F; normal low is now 17F

DAILY RECORDS FOR JANUARY 2018

01/04/18: NEW DAILY RECORD MAXIMUM SNOWFALL OF 16.5 INS.
PREVIOUS RECORD WAS 8.6 INS. SET IN 1923 AND
TIED IN 1942

01/07/18: DAILY RECORD LOW MINIMUM TEMPERATURE OF -8F,
PREVIOUS RECORD OF -7F WAS SET IN 1896

01/12/18: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 45F,
PREVIOUS RECORD OF 42F WAS SET IN 2017

DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 60F,
PREVIOUS RECORD OF 59F WAS SET IN 2017

01/13/18: DAILY RECORD HIGH MAXIMUM TEMPERATURE OF 60F,
PREVIOUS RECORD OF 57F WAS SET IN 1890 AND
TIED IN 1932

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

RECORDS FOR JANUARY 20
HIGH 59F IN 1951
LOW -9F IN 1901
PRECIP 1.95 INS. IN 1978
SNOWFALL 19.0 INS. IN 1978
PEAK GUST 76e MPH NE IN 1978

RECORDS FOR JANUARY 21
HIGH 65F IN 1906
LOW -4F IN 1888,1893
PRECIP 2.49 INS. IN 1979
SNOWFALL 9.0 INS. IN 2014
PEAK GUST 78e MPH SE IN 1979

TODAY’S REPORT PREPARED BY: Jonathan O’Brien