BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, MAY 14, 2007   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
VERY SUNNY, WARM, AND VERY DRY MAY CONTINUES
EARLY MORNING TEMPERATURE INVERSION BRINGS A 
MID-MAY FREEZE TO SOME NEARBY SHELTERED LOCATIONS
 
A forest fire broke out about 1.7 miles a little south of east 
of the Observatory within the reservation about 1:30 P.M. The
smoke plume was drifting E-ESE.
 
Temperatures have reached the lower 70's early this afternoon 
and the air continues very dry. Dewpoints in the upper 
20's to around 30 degrees give relative humidities well 
down in the 20% range.  Today's high temperatures are running
several degrees above normal after a morning low of 43 degrees
was a few degrees on the cool side. Low temperatures were much 
colder and reached freezing levels in surrounding traditional 
cold spots with 30 degrees at Norwood and Taunton Airports. 
 
This continues to be a very dry month with just 0.10 inch of 
rainfall to date. Showers on Friday and very late Saturday 
night yielded a total of just 0.04 inch.  Sunshine for the 
month is still well over the 70% mark while early afternoon
humidity levels are averaging close to 20% below the normal. 
 
The monthly temperature average is 4 degrees above normal and 
only two days our of 14 have been cooler than average and two 
days including yesterday have averaged out just normal.
 
Today's observations:
 
7 A.M.   
Weather: Clear with few cirrus NNW-ESE 
Temperature: 51F, Dew point: 26F, Wind: W at 08 kts  
Sea-level pressure: 30.26 inches Hg, steady
Visibility: 75 miles 
6-hour min. 43F
BHO SA 1155 CLR 75 247/51/26/2608/026/ FEW CI NNW-ESE 
LGT DSNT HZ INVSN DSSPTNG WND GRDLY BACKING/ 
8/001 51013 10051 20043 
 
10 A.M.
Weather: Clear 
Temperature: 65F, Dew point: 27F, Wind: W at 11G19 kts 
Wind: Variability in direction SW to NW 
Sea-level pressure: 30.24 inches Hg, falling   
Visibility: 60-70 miles    
BHO SA 1455 CLR 60 239/65/27/2711G19/024/ VSBY NW 70
LGT HZ WND 23V31/ 58008 
 
1 A.M.
Weather: Scattered small cumulus and cirrus 
Temperature: 72F, Dew point: 29F, Wind: W at 11G23 kts 
Wind: Peak wind WNW 26 kts @ 38 pst hour; variability in direction SW to WNW 
Sea-level pressure: 30.19 inches Hg, falling   
Visibility: 60 miles, 70 NW light haze     
Six hourly max. temp: 72  
BHO SA 1755 70 SCT 220 SCT 60 224/72/29/2711G23/019/
SML CU ALQDS CI SW-NW LGT HZ VSBY NW 70 PK WND 2926/38/ 
WND 22V30 FOREST FIRE BEGAN PST HR 1.7 MILES EXS K PLUME 
DRFTG TWRD 100-110 DEG AZ/ 8/101 56015 10072 20051
 
WEATHER SUMMARY FOR SUNDAY, MAY 13, MOTHERS DAY 
 
TEMPERATURE (DEGREES F)
MAX.....65    NORMAL.....66 
MIN.....46    NORMAL.....46
MEAN....56    NORMAL.....56
DEPARTURE FROM 30-YEAR NORMAL........... 0
TOTAL DEPARTURE FOR THE MONTH..........+56 (+4.1 DEGREES/DAY)
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY........... 9  DEPARTURE..........0
TOTAL HEATING UNITS FOR THE MONTH..........102  DEPARTURE........-41 
TOTAL HEATING UNITS FOR THE SEASON........5718  DEPARTURE.......-455
TOTAL HEATING UNITS LAST SEASON TO DATE...5587  DIFFERENCE......+131
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY............33 WNW  AT  4:26 P.M.  
                   AEROVANE.............33 WNW  AT  4:26 P.M.  
                   ASOS.................31 WNW  AT  6:16 P.M. 
                   DAVIS................33 WNW  AT  4:04 P.M. 
FASTEST MILE FOR YESTERDAY..............24  NW  AT  3:34 P.M.  
MAXIMUM 2-MINUTE ASOS AVERAGE...........25  NW  AT  3:34 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE..........26  WNW AT  3:34 P.M. 
AVERAGE WIND SPEED AND DIRECTION.......11.2 NW
                    ASOS...............11.6   
                    DAVIS..............11.1 NW [310 degrees] 
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00   DEPARTURE....-0.12
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........0.10   DEPARTURE....-1.51 
                         ASOS..............0.08    
TOTAL PRECIPITATION FOR THE YEAR..........20.52   DEPARTURE....+0.96
                         ASOS.............20.05    
 
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..............27.6  DEPARTURE.....-32.5  
    
PRELIMINARY CLIMATE SUMMARY FOR MAY 2007......CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
 
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available
 
5/1  67/44/56/+4/0/0/624/74      33 NW 
5/2  64/45/55/+3/0.06/0/381/45   36 NW    Aero 33 MPH WNW
5/3  67/42/55/+2/0/0/849/100     38 W     Aero 37 MPH W
5/4  66/44/55/+2/0/0/842/99      39 WNW   Aero 40 MPH WNW 
5/5  65/45/55/+2/0/0/384/45      33 N  
5/6  51/42/47/-7/T/0/514/60      36 N     Aero 33 MPH N 
5/7  68/39/54/0/0/0/798/93       25 S
5/8  77/43/60/+6/0/0/851/99      33 S     Aero 31 MPH S 
5/9  85/54/70/+15/0/0/707/92     30 S 
5/10 85/60/73/+18/0/0/692/80     29 S     Aero 27 MPH S
5/11 74/60/67/+12/0.02/0/355/41  23 S
5/12 63/47/55/-1/0.02/0/.../..   32 NE    
5/13 65/46/56/0/T/0/775/89       33 WNW   Aero 33 MPH WNW 
 
5/14 morning low temp. 43 deg; normal now 46 deg.
 
DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 14
HIGH 85F IN 1961
LOW 33F IN 1895
PRECIP 1.93 INCHES IN 2006
PEAK GUST 50e MPH SW IN 1976
 
RECORDS FOR MAY 15
HIGH 93F IN 1900
LOW 36F IN 1947,1985
PRECIP 1.63 INCHES IN 1978
PEAK GUST 53e MPH NE IN 1978, W 2002
 
TODAY'S REPORT PREPARED By: Robert Skilling