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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, JANUARY 21, 2015   
ALL TIMES ARE IN EASTERN STANDARD TIME

CLEAR, COLD START, CLOUDS FILTER IN BY MID-DAY

Diminishing winds and clearing skies were present
come sunrise this morning as temperatures bottomed
out just after the 7:00 AM EST observation. This
morning's minimum of 17F ties the daily normal minimum
for today. Excellent visibility of 80 miles was present
this morning, while nearly cloudless skies became
covered by high cirrus.

At the 1:00 PM EST observation a thin layer of cirrostratus
had overspread the area reducing visibility somewhat to
70 miles in all directions. A maximum reading of 30F 
was recorded so far today.


Today's Observations:

7 A.M.
Weather: Clear, few cirrus distant ESE-SW
Temperature: 18F; Dew Point: 11F; Wind: NW at 7 kts
Sea-level pressure: 30.12 ins. Hg, rising, then more quickly                   
Visibility: 80 miles
6-hr max temp: 23F
6-hr min temp: 17F
24-hr precip: None 
BHO SA 1155 CLR 80 200/18/11/3107/012/ FEW CI DSNT ESE-SW/ 
8/001 53020 10023 20017

10 A.M. 
Weather: Broken cirrus 
Temperature: 27F; Dew Point: 7F; Wind: estimated N at 3 kts
Sea-level pressure: 30.17 ins. Hg, rising, then more quickly    
Visibility: 80 miles  
BHO SA 1455 E250 BKN 80 218/27/7/E3503/017/ WND LGT AND VRB/ 
8/004 53018

1 P.M. 
Weather: Thin overcast of cirrostratus
Temperature: 30F; Dew Point: 9F; Wind: estimated NE at 3 kts,
Sea-level pressure: 30.18 ins. Hg, falling, then rising  
Visibility: 70 miles 
6-hr max temp: 30F
6-hr min temp: 17F
BHO SA 1755 E200 -OVC 70 219/30/9/E0503/018/ WND LGT AND VRB/ 
8/007 53001 10030 20017 
 

SUMMARY FOR TUESDAY, JANUARY 20, 2015

TEMPERATURE (DEGREES F)
MAX.....36   NORMAL.....33
MIN.....23   NORMAL.....17
MEAN....30   NORMAL.....25

DEPARTURE FROM 30-YEAR NORMAL..........................+5
TOTAL DEPARTURE FOR THE MONTH.........................-29 [-1.7 DEGREES/DAY] 
 
HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY..............35  DEPARTURE...........-5
TOTAL HEATING UNITS FOR THE MONTH.............818  DEPARTURE..........+30     
TOTAL HEATING UNITS FOR THE SEASON...........2878  DEPARTURE.........-215
TOTAL HEATING UNITS LAST SEASON TO DATE......2999  DIFFERENCE........-121

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY..................28  W    AT  1:58 A.M.  
                   ASOS.......................29  W    AT  1:58 A.M. 
                   DAVIS......................27  W    AT  2:11 P.M. RMY 28
FASTEST MILE FOR YESTERDAY....................22  W    AT  2:09 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE.................23  W    AT  2:11 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE................20  W    AT  2:11 P.M. 
AVERAGE WIND SPEED AND DIRECTION............14.1  W
                   ASOS.....................14.0   
                   DAVIS....................12.2  W [270 degrees]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00  DEPARTURE.....-0.14 
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........1.74  DEPARTURE.....-1.10 
                         ASOS..............1.82  
TOTAL PRECIPITATION FOR THE YEAR...........1.74  DEPARTURE.....-1.10
                         ASOS..............1.82  

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE......-0.5
TOTAL SNOWFALL FOR THE MONTH................4.9  DEPARTURE......-6.3
TOTAL SNOWFALL FOR THE SEASON..............15.9  DEPARTURE.....-11.3  

PRELIMINARY CLIMATE SUMMARY FOR JANUARY CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY 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

1/1  31/18/25/-2/0.00/0.0/544/99              29 SSW RMY 30 
1/2  37/26/32/+5/0.00/0.0/314/57              35 WSW RMY 38
1/3  34/21/28/+2/0.67/2.5/017/03              25 SE  RMY 26   
1/4  51/33/42/+16/0.48/0.0/000/00             30 SSW RMY N/A
1/5  46/13/30/+4/0.00/0.0/542/98              48 W   RMY 54
1/6  15/10/13/-13/0.02/0.4/000/00             29 W   RMY N/A
1/7  22/01/12/-14/0.01/0.3/383/69             43 WNW RMY 47  
1/8  16/-5/6/-20/0.00/0.0/539/97              39 WNW RMY N/A 
1/9  27/16/22/-4/0.08/0.9/201/36              35 WSW RMY 38  
1/10 22/11/17/-8/0.00/0.0/541/97              26 WNW RMY 27
1/11 31/9/20/-5/45/0.00/0.0/123/22            26 SSW RMY N/A 
1/12 36/31/34/+9/0.23/T/000/00                29 NNW RMY N/A
1/13 33/11/22/-3/0.00/0.0/524/93              30 NNW RMY 29
1/14 22/11/17/-8/T/T/000/00                   18 NNW RMY 16
1/15 27/20/24/-1/0.09/0.8/000/00              20 WSW RMY 22 
1/16 35/12/24/-1/T/T/.../..                   46 WSW RMY 50
1/17 21/5/13/-12/0.00/0.0/.../..              30 WNW RMY N/A 
1/18 50/19/35/+10/0.16/0.0/000/00             47 SE  RMY 52
1/19 44/28/36/+11/T/0.0/.../..                33 W   RMY 36
1/20 36/23/30/+5/0.00/0.0/.../..              28 W   RMY 28

1/21 morning low temp: 17F since midnight; normal low is now 17F

DAILY RECORDS FOR JANUARY 2015
None so far.

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

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

RECORDS FOR JANUARY 22
HIGH 59F IN 1916
LOW -8F IN 1888,1976
PRECIP 1.24 INS. IN 1891,1987
SNOWFALL 10.0 INS. IN 2005
PEAK GUST 67 MPH W IN 1976

TODAY'S REPORT PREPARED BY: Brian Fitzgerald