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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, MARCH 22, 2018  
ALL TIMES ARE IN EASTERN STANDARD TIME

LIGHT SNOW BECOMES LIGHT DRIZZLE MID-AFTERNOON
AFTER TEMPERATURE RISES ABOVE FREEZING...

Light snow began yesterday afternoon with sporadic
showers until early this morning when snow became
continuous. Mid-morning temperatures began to rise 
and the light snow became a light drizzle and was 
very light by the 1:00 P.M. observation. We measured 
a total of 3.6 ins. of snowfall and 0.45 ins. of 
liquid precipitation with this storm. 
We had strong wind from the NE last night into early 
this morning with a two peaks gust of 37 kts (43 MPH). 
We observed a decrease in wind speed throughout the
day, with light wind after 1:00 P.M. We also observed 
a slight wind shift and the wind is now heading from 
the north. This is allowing for the trend of below 
seasonable daily maximum temperatures to continue. 
Yesterday we had a max temperature of 35F, which is 9 
degrees below the daily normal of 46F. Today temps. 
remained below freezing until 10:00 A.M. Then temps. 
began to steadily rise and we observed a maximum of 
36F by 1:00 P.M. This is 10 degrees below the daily 
normal of 46F. Daily lows have been close to normal 
with a minimum of 31F which is 3 degrees above normal. 
Since midnight we have had a low of 30F which is 2 
degrees above the normal of 28F. 
Skies remained overcast so far today. In the morning
visibility was limited to 1/2-3 miles due to fog. 
In the afternoon visibility greatly increased to 40 
miles with a lingering distant fog.  

Today's Observations:

7 A.M.
Weather: Light snow and fog, overcast nimbostratus
Temperature: 30F; Dew Point: 29F; Wind: N at 14G23 kts
Sea-level pressure: 29.65 ins. Hg, falling then rising           
Visibility: 1/2 mile
6-hr Max temp: 30F
6-hr Min temp: 29F
24-hr precip:  0.38 ins.
24-hr snowfall: 3.0 ins.
Snow depth: 15 ins.
BHO SA 1155 E8 OVC 1/2S-F 040/30/29/3514G23/965/ NEW SNW PST 
24 HRS 3.0 INS./ 8/6// 4/015 53002 MANUAL 70038 ASOS 70036 
10032 20030  

10 A.M.
Weather: Light snow and fog, overcast nimbostratus
Temperature: 32F; Dew Point: 31F; Wind: NNW at 14G24 kts  
Sea-level pressure: 29.67 ins. Hg, rising then steady 
Visibility: 2 miles, except SW-NNE 1/2 mile 
3-hr precip:  0.07 ins.
3-hr snowfall: 0.6 ins.    
BHO SA 1455 E11 OVC 2S-F 047/32/31/3414G24/967/ NEW SNW PST 
3 HRS 0.6 INS. VSBY 1/2 SW-NNE/ 8/6// 52007 MANUAL 6007/ 
ASOS 60009  

1 P.M.
Weather: Very light drizzle, overcast nimbostratus, sun
dimly visible  
Temperature: 35F; Dew Point: 34F; Wind: N at 11G16 kts
Sea-level pressure: 29.89 ins. Hg, rising, then more rapidly
Visibility: 40 miles, distant fog in all directions 
6-hr Max temp: 36F
6-hr Min temp: 30F
6-hr precip:  0.07 ins.
6-hr snowfall: 0.6 ins.
Storm total: 3.6 ins.
Snow depth: 14 ins.
BHO SA 1755 E13 OVC 40L- 054/35/34/3511G16/989/ NEW SNW PST
6 HRS 0.6 INS. NEW STORM TOTAL OF 3.6 INS. PCPN VRY LGT SUN 
DMLY VSBL DSNT FG ALQDS/ 8/6// 4/014 53007 MANUAL 6007/ 
ASOS 60010 10036 20030
 
SUMMARY FOR WEDNESDAY, MARCH 21, 2018

TEMPERATURE (DEGREES F)
MAX.....35   NORMAL.....46
MIN.....31   NORMAL.....28
MEAN....33   NORMAL.....37

DEPARTURE FROM 30-YEAR NORMAL............................-4
TOTAL DEPARTURE FOR THE MONTH...........................-32 [-1.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY.............32   DEPARTURE..........+4
TOTAL HEATING UNITS FOR THE MONTH............691   DEPARTURE.........+37
TOTAL HEATING UNITS FOR THE SEASON..........4813   DEPARTURE........-409
TOTAL HEATING UNITS LAST SEASON TO DATE.....4603   DIFFERENCE.......+210

PEAK GUST AND AVERAGE WIND SPEED (MPH) 
PEAK WIND GUST FOR YESTERDAY...................43 NE AT 11:53 P.M.  
                   AERO........................44 NE AT 11:48 P.M.
                   ASOS........................43 NE AT 11:54 P.M.
                   DAVIS.......................42 M  AT 11:49 A.M ** RMY N/A
FASTEST MILE FOR YESTERDAY.....................26 NE AT 11:53 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE..................26 NE AT 11:55 P.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE.................26 M  AT 11:14 P.M.**
AVERAGE WIND SPEED AND DIRECTION.............17.5 NE
                   ASOS......................17.4 
                   DAVIS.....................15.5 ** 
** Davis direction malfunctioning

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.38  DEPARTURE......+0.18
                         ASOS..............0.36
TOTAL PRECIPITATION FOR THE MONTH..........8.35  DEPARTURE......+4.81
                         ASOS..............9.04  
TOTAL PRECIPITATION FOR THE YEAR..........18.46  DEPARTURE......+6.50
                         ASOS.............19.89

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........3.0  DEPARTURE........+2.7
TOTAL SNOWFALL FOR THE MONTH...............43.1  DEPARTURE.......+33.4
TOTAL SNOWFALL FOR THE SEASON..............87.8  DEPARTURE.......+31.0

PRELIMINARY CLIMATE SUMMARY FOR MARCH 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

3/01 61/37/49/+18/0.00/0.0/378/56    39 ENE AERO 37 ENE RMY N/A 
3/02 40/32/36/+5/3.47/0.7/000/00     73 NNE AERO 70 NNE RMY N/A
3/03 40/32/26/+4/T/T/034/05          52 NNE AERO 50 NNE RMY 49
3/04 39//34/37/+5/T/T/000/00         36 NNE AERO 32 NNE RMY 32 
3/05 40/29/35/+3/.../1.2/261/38      40 NE  AERO 39 NE  RMY 40
3/06 34/29/32/0/0.00/0.0/062/09      20 N   AERO 16 N   RMY N/A
3/07 35/31/33/0/..../.../000/00      52 ENE AERO 53 ENE RMY 50 
3/08 34/28/31/-2/..../.../000/00     44 NNE AERO 47 NNE RMY N/A
3/09 36/24/30/-3/T/T/265/38          28 W   AERO 26 W   RMY N/A 
3/10 37/28/33/0/0.00/0.0/343/49      38 WNW AERO 38 WNW RMY 41
3/11 42/26/34/0/0.00/0.0/583/83      28 NW  AERO 26 NW  RMY 29
3/12 39/26/33/-1/T/T/155/22          36 ENE AERO 33 ENE RMY N/A
3/13 35/26/31/-3/..../23.0/000/00    60 N   AERO 60 N   RMY 64
3/14 36/24/30/-5/..../.../470/66     38 WSW AERO 38 WSW RMY 41
3/15 40/29/35/0/..../.../.../..      44 W   AERO 44 W   RMY 44
3/16 35/23/29/-6/0.00/0.0/.../..     41 NW  AERO 41 NW  RMY 45
3/17 40/15/28/-8/0.00/0.0/.../...    46 W   AERO 45 W   RMY 49
3/18 31/10/21/-15/0.00/0.0/.../..    39 NW  AERO 38 NW  RMY 40
3/19 35/13/24/-12/0.00/0.0/.../..    32 WNW AERO 32 WNW RMY 34
3/20 40/18/29/-8/0.00/0.0/.../..     23 NW  AERO 21 NW  RMY N/A
3/21 35/31/33/-4/.../.../000/00      43 NE  AERO 44 NE  RMY N/A

3/22 Low temp since midnight is 30F; normal low is now 28F

DAILY RECORDS FOR MARCH 2018

3/02/18: NEW DAILY RECORD MAXIMUM PRECIPITATION OF 3.47 INS.
         PREVIOUS RECORD WAS 2.15 INS. SET IN 1983

3/13/18: NEW DAILY RECORD MAXIMUM SNOWFALL OF 23.0 INS.
         PREVIOUS RECORD WAS 10.0 INS. SET IN 1993

3/13/18: NEW MONTHLY RECORD MAXIMUM DAILY SNOWFALL OF 23.0 INS.
         PREVIOUS RECORD WAS 18.0 INS. SET ON 8 MARCH 2013

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

RECORDS FOR MARCH 22
HIGH 81 IN 2012
LOW 3 IN 1885
PRE 3.48 INS. IN 2001
SNOW 8.7 INS. 1967
WIND 84e MPH E IN 1977

RECORDS FOR MARCH 23
HIGH 78 IN 1938
LOW 3 IN 1934
PRE 2.52 INS. IN 2010
SNOW 3.0 INS. IN 1977
WIND 78e MPH W IN 1940

TODAY'S REPORT PREPARED BY: Kaitlin A. Geagan