BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 21, 2012
ALL TIMES ARE IN EASTERN STANDARD TIME
 
Low overcast today with no sunshine and much cooler temperatures
held down in the 60's this afternoon.  A period of very light
drizzle occurred early this morning with just a trace of
precipitation. 
 
Today's observations:
 
7 A.M.
Weather: Obscured with heavy fog, light drizzle occurring, began 6:45 A.M.
Temperature: 56F, Dew Point: 55F; Wind: NE at 5 kts,
Sea-level pressure: 30.29 inches Hg, rising, then more rapidly 
Visibility: 1/8 mile, heavy fog, visibility lowered rapidly past hour  
6-hour min. temp: 52F
6-hourly precip: trace
24-hourly precip: trace
BHO SA 1155 W3 X 1/8L-F 256/56/55/0505/029/ STRA DRFTG OVR SMT
VSBY LWRD RPDLY PST HR LB45 PCPN VRY LGT 8//// 53006 MANUAL 6000/
10056 20052
 
10 A.M.
Weather: Low overcast stratus, stratus drifting below summit NW-NE,
occasionally drifting over the summit   
Temperature: 59F, Dew Point: 56F; Wind: ENE at 6 kts
Sea-level pressure: 30.27 inches Hg, falling, then more rapidly  
Visibility: 2 miles, fog, except 1 mile N, 5 miles SE, 6 miles S, 8 miles SW
3-hourly precip: trace  
BHO SA 1455 E3 OVC 2F 251/59/56/0706/027/ STRA DRFTG BLO AND OCNL OVR SMT
VSBY N 1 SE 5 S 7 SW 8/6// 58005 MANUAL 6000/  
 
1 P.M.
Weather: Overcast stratus, bright spots in the overcast,
ceiling lower N-ESE, fog bank extending N-ESE
Temperature: 63F, Dew Point: 57F; Wind: ENE at 7 kts,
Wind: Direction variable NNE-E
Sea-level pressure: 30.22 inches Hg, falling, then more slowly 
Visibility: 15 miles, thin fog/haze, except 7 miles N-ESE, fog bank
6-hour max. temp: 64F
6-hour precip: trace  
BHO SA 1755 E10 OVC 15 234/63/57/0607/022/ CIG LWR N-SE BRGHT SPTS IOVC 
FG BNK N-ESE VSBY N-ESE 7 WNW 20 THN F/HZ ALQDS WND 02V09/ 8/6// 56017
MANUAL 6000/ 10064 20056 
 
WEATHER SUMMARY FOR SUNDAY, MAY 20
 
TEMPERATURE (DEGREES F)
MAX.....79    NORMAL.....68
MIN.....56    NORMAL.....49
MEAN....68    NORMAL.....58
 
DEPARTURE FROM 30-YEAR NORMAL.......................+10
TOTAL DEPARTURE FOR THE MONTH.......................+36 [+1.6 DEGREE/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY...............0   DEPARTURE..........-7
TOTAL HEATING UNITS FOR THE MONTH.............161   DEPARTURE.........-44
TOTAL HEATING UNITS FOR THE SEASON...........4875   DEPARTURE.......-1356
TOTAL HEATING UNITS LAST SEASON TO DATE......6119   DIFFERENCE......-1244
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............17 SE  AT  5:07 P.M.     
                   AERO..................17 SE  AT  5:07 P.M.    
                   ASOS..................16 SE  AT  5:19 P.M. .  
                   DAVIS.................17 SE  AT  5:06 P.M. RMY 18 MPH
THE FASTEST MILE FOR YESTERDAY...........13 SE  AT  5:08 P.M.     
MAXIMUM 2-MINUTE ASOS AVERAGE............12 ESE AT  5:13 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE...........13 SE  AT  4:50 P.M.   
AVERAGE WIND SPEED AND DIRECTION....... 7.4 SE   
                   ASOS.................7.3 
                   DAVIS................7.0 SE [140 deg.]
 
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..........2.95   DEPARTURE..........+0.47
                         ASOS..............2.87
TOTAL PRECIPITATION FOR THE YEAR..........12.56   DEPARTURE..........-8.47
                         ASOS.............12.60
     
SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0    DEPARTURE...........0.0
TOTAL SNOWFALL FOR THE MONTH................0.0    DEPARTURE..........-0.1
TOTAL SNOWFALL FOR THE SEASON..............24.2    DEPARTURE.........-35.9
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2012 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane wind recording system gust when significant
RMY:  RMY = R.M. Young wind gust recording system added 8/9/2011
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
5/1  47/42/45/-8/0.65/0.0/000/00    33 SE  AERO 36 MPH SE  RMY 37
5/2  50/43/47/-6/0.05/0.0/000/00    16 ENE AERO 16 MPH ENE RMY 17
5/3  51/44/48/-5/0.08/0.0/000/00    14 SSE AERO 16 MPH SSE RMY N/A
5/4  56/47/52/-2/0.01/0.0/000/00    21 SSW AERO 25 MPH SSW RMY 23
5/5  57/46/52/-2/0.04/0.0/034/04    14 NE  AERO 15 MPH NE  RMY 15
5/6  58/45/52/-2/0.00/0.0/532/62    21 ENE AERO 21 MPH ENE RMY 21
5/7  67/48/58/+3/0.00/0.0/740/86    23 S   AERO 25 MPH S   RMY 25
5/8  57/48/53/-2/0.18/0.0/000/00    40 S   AERO 46 MPH S   RMY 46
5/9  61/54/58/+3/0.36/0.0/000/00    25 S   AERO 28 MPH S   RMY N/A
5/10 65/46/56/+1/0.98/0.0/234/27    33 W   AERO 36 MPH W   RMY 37
5/11 62/42/52/-4/T/0.0/539/62       30 WNW AERO 33 MPH WNW RMY 34
5/12 77/46/62/+6/0.00/0.0/862/99    30 W   AERO 30 MPH W   RMY 29
5/13 82/57/70/+14/0.00/0.0/314/36   27 S   AERO 29 MPH S   RMY 29
5/14 71/52/62/+5/0.05/0.0/096/11    23 S   AERO 24 MPH S   RMY 23
5/15 72/57/65/+8/0.43/0.0/123/14    32 S   AERO 35 MPH S   RMY 33
5/16 71/58/65/+8/0.12/0.0/141/16    23 S   AERO 24 MPH S   RMY N/A
5/17 69/50/60/+3/0.00/0.0/784/89    31 WNW AERO 32 MPH WNW RMY 26
5/18 69/49/59/+1/0.00/0.0/857/97    17 ESE AERO 17 MPH ESE RMY 17
5/19 74/51/63/+5/0.00/0.0/876/99    15 WNW AERO 15 MPH WNW RMY 16
5/20 79/56/68/+10/0.00/0.0/727/82   17 SE  AERO 17 MPH SE  RMY 17
 
5/21 morning low temp: 52F; the normal low is now 49F
 
DAILY RECORDS FOR MAY 2012
5/16 - Minimum temperature of 56F equals record high minimum
      for the date set in 1951 and 1961
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 21
HIGH 92F IN 1921
LOW 35F IN 1907
PRECIP 1.61 INS IN 1954
PEAK GUST 74 MPH WSW IN 2006
 
RECORDS FOR MAY 22
HIGH 93F IN 1911
LOW 35F IN 1907
PRECIP 3.75 INCHES IN 1920
PEAK GUST 49e MPH SSW IN 1947
 
TODAY'S REPORT PREPARED BY: Robert Skilling / Patrick Peters