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

DAILY DISCUSSION AND CLIMATE SUMMARY
SUNDAY, JANUARY 21, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

SKIES CLEAR WITH WARM CONDITIONS

Winds shifted from the south-southwest to west this morning before beginning 
to turn back towards the south. Keeping the warmer weather in place.   Low 
Temperatures did not get below freezing last night with a low of 33 degrees. 
As temperatures warmed into the mid 40s, the winds went very light to calm 
around noon and remained light and variable through the 1 o'clock observation.  

Skies remained partly cloudy throughout the day.  Early altocumulus and 
altostratus clouds moved out leaving only the morning's cirrostratus behind.  
As the day progressed, the cirrostratus was also moving out of the area but were
replaced by more altostratus by the 1 o'clock observation.  

Visibility today has ranged around 50 miles. The snow on the ground continues 
to melt with just a few patches remaining around the summit.  

Today's Observations:

7 A.M.
Weather: Scattered Altocumulus and Altostratus, Scattered cirrostratus
Temperature: 34F; Dew Point: 29F; Wind: NW at 8 kts
Sea-level pressure: 30.07 ins. Hg, rising, then less quickly
Visibility: 50 miles, light distant haze
6-hr Max temp: 37F
6-hr Min temp: 34F
24-hr precip: 0.00 ins.
24-hr snowfall: 0.0 ins.
Snow depth: Trace
BHO SA 1155 150 SCT 250 SCT 50 182/34/29/3108/007/ LGT DSNT HZ/ 8/078 51018 
10037 20034

10 A.M.
Weather: Scattered Cirrostratus, few altostratus NW-NNE
Temperature: 40F; Dew Point: 29F; Wind: WSW at 05 kts,
Wind: Light
Sea-level pressure: 30.14 ins. Hg, rising, then more slowly 
Visibility: 50 miles, light distant haze
3-hr precip: 0.00 ins.
3-hr snowfall: 0.0 ins. 
BHO SA 1455 250 SCT 50 208/40/29/2505/014/ LGT DSNT HZ WND LGT/ 8/078 51026

1 P.M.
Weather: Few Altostratus all quadrants, Few Cirrostratus NW-ENE
Temperature: 47F; Dew Point: 30F; Wind: NW at 4 kts,
Wind: Light
Sea-level pressure: 30.10 ins. Hg, falling then more quickly
Visibility: 50 miles, distant haze 
6-hr precip: 0.00 ins.
6-hr snowfall: 0.0 ins.
6-hr Max temp: 47F
6-hr Min temp: 34F
Snow depth: Trace
BHO SA 1755 CLR 50 194/47/30/3204/010/ FEW AS ALQDS FEW CS NW-ENE LGT DSNT HZ 
WND LGT/ 8/078 58014 10047 20034 

SUMMARY FOR SATURDAY, JANUARY 20, 2018

TEMPERATURE (DEGREES F)
MAX.....45   NORMAL.....33
MIN.....27   NORMAL.....17
MEAN....36   NORMAL.....25

DEPARTURE FROM 30-YEAR NORMAL...........................+11
TOTAL DEPARTURE FOR THE MONTH..........................-51 [-2.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............29  DEPARTURE.........-11
TOTAL HEATING UNITS FOR THE MONTH............840  DEPARTURE.........+52
TOTAL HEATING UNITS FOR THE SEASON..........2962  DEPARTURE........-131
TOTAL HEATING UNITS LAST SEASON TO DATE.....2705  DIFFERENCE.......+259

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................38  WSW  AT 11:22 A.M.
                   AERO........................37  WSW  AT 11:23 A.M.
                   ASOS........................39  W    AT 11:23 A.M.
                   DAVIS.......................38  M    AT 11:22 A.M. RMY 39 
FASTEST MILE FOR YESTERDAY.....................28  WSW  AT 11:23 A.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE..................29  W    AT 11:23 A.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................29  M    AT 11:23 A.M.
AVERAGE WIND SPEED AND DIRECTION..............17.3 WSW
                   ASOS.......................16.8 
                   DAVIS......................15.6
*Davis direction malfunctioning

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..........4.19  DEPARTURE......+1.35
                         ASOS..............4.63
TOTAL PRECIPITATION FOR THE YEAR...........4.19  DEPARTURE......+1.35
                         ASOS..............4.63

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0  DEPARTURE........-0.5
TOTAL SNOWFALL FOR THE MONTH...............19.3  DEPARTURE........+8.1
TOTAL SNOWFALL FOR THE SEASON..............28.6  DEPARTURE........+1.4

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 45/27/36/+11/0.00/0.0/.../..       38 WSW AERO 37 WSW RMY 39 

1/21 Low temp since midnight is 34F; 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 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: Robert Millette