BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, MAY 27, 2009   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
LIGHT RAIN THIS MORNING FOLLOWED BY
CONTINUED OVERCAST WEATHER AND VERY
COOL TEMPERATURES WITH EAST WINDS
 
This morning's rainfall totaled 0.14 inch after
the occurrence of light rain beginning during
the pre-dawn hours and ending just after 9 a.m.
EDT. Temperatures dropped to 43F just as the
rain and drizzle were ending and had only risen
to 50F by early afternoon.
 
Today's observations:
 
7 A.M.  
Weather: Overcast nimbostratus clouds, light rain and fog 
Temperature: 45F, Dew point: 44F, Wind: E at 11 kts,
Wind: direction slowly backing  
Sea-level pressure: 30.18 inches Hg, falling
Visibility: 5 miles, N-E 10 miles, S-SW 3 miles,
lowering visibility past hour
6-hour minimum temp: 45F
24-hour precipitation: 0.04 in.  
BHO SA 1155 E38 OVC 5R-F 219/45/44/1011/018/
CIG/VSBY LWRG PST HR VSBY N-E 10 S-SW 3/ 8/02/
58003 ASOS 60003 MANUAL 6004/ ASOS 70003
MANUAL 70004 10048 20045
 
10 A.M.  
Weather: Broken stratus fractus, overcast nimbostratus
with fractus drifting below summit 
Temperature: 46F, Dew point: 45F, Wind: E at 8 kts,
Sea-level pressure: 30.14 inches Hg, falling
Visibility: 15 miles, except 10 miles NW-N and 12
miles to the northeast, thin fog
3-hourly rainfall: 0.10 inch 
BHO SA 1455 E4 BKN 28 OVC 15 207/46/45/1008/014/ CIG RGD FEW
STFRA DRFTG BLO SMT VSBY NW-N 10 NE 12/8/72/
58012 ASOS 60010 MANUAL 6010/
 
1 P.M.  
Weather: Overcast nimbostratus, few stratus fractus 
Temperature: 50F, Dew point: 47F, Wind: E at 6 kts
Sea-level pressure: 30.09 inches Hg, falling
Visibility: 25 miles
6-hour maximum temp: 50F  
BHO SA 1755 E20 OVC 25 188/50/47/0806/009/ FEW STFRA ALQDS/
8/72/ 58019 ASOS 60010 MANUAL 6010/ 10050 20043
 
WEATHER SUMMARY FOR TUESDAY, MAY 26
 
TEMPERATURE (DEGREES F)
MAX.....58    NORMAL.....70
MIN.....46    NORMAL.....50
MEAN....52    NORMAL.....60
 
DEPARTURE FROM 30-YEAR NORMAL...........-8
TOTAL DEPARTURE FOR THE MONTH..........+69 [+2.5 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY............13  DEPARTURE.......+6
TOTAL HEATING UNITS FOR THE MONTH...........178  DEPARTURE......-67
TOTAL HEATING UNITS FOR THE SEASON.........6074  DEPARTURE.....-196
TOTAL HEATING UNITS LAST SEASON TO DATE....5886  DIFFERENCE....+188
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............28 NNE AT 1:51 A.M.  
                   AEROVANE..............23 NNE AT 1:45 A.M. * 
                   ASOS..................25 NNE AT 1:51 A.M.   
                   DAVIS.................25 NNE AT 1:50 A.M.  
FASTEST MILE FOR YESTERDAY...............18 ENE AT 7:03 A.M.   
MAXIMUM 2-MINUTE ASOS AVERAGE............18 ENE AT 7:03 A.M.  
MAXIMUM 2-MINUTE DAVIS AVERAGE...........19 ENE AT 7:03 A.M.   
AVERAGE WIND SPEED AND DIRECTION.......  10.1 NE
                   ASOS..................10.1  
                   DAVIS.................9.8 ENE [070 DEG]
* last of several occurrences...
 
PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.04  DEPARTURE....-0.08
                         ASOS..............0.03
TOTAL PRECIPITATION FOR THE MONTH..........3.49  DEPARTURE....+0.32
                         ASOS..............3.48 
TOTAL PRECIPITATION FOR THE YEAR..........18.10  DEPARTURE....-3.02
                         ASOS.............19.16 
 
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..............78.9  DEPARTURE.....18.8 
 
PRELIMINARY CLIMATE SUMMARY FOR MAY 2009 CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system gust when significant
TSTM: Thunderstorm day (thunder heard some time during day)
....: Data not yet available, records not finalized
 
5/1  64/53/59/+7/T/000/00          37 SSW   AERO 37 MPH SSW
5/2  68/52/60/+8/0.05/263/31       32 WNW
5/3  64/48/56/+3/T/068/08          25 S
5/4  64/48/56/+3/0.01/009/01       17 SSW
5/5  52/44/48/-5/0.95/000/00       43 NNE   AERO 40 MPH NNE
5/6  63/43/53/-1/0.40/189/22       24 SSE  
5/7  68/49/59/+5/0.60/009/01       29 S    
5/8  75/52/64/+10/0/690/80         28 S
5/9  71/55/63/+8/0.14/104/12       31 W     TSTM
5/10 65/46/56/+1/0/840/97          53 W     Aero 50 MPH W
5/11 63/41/52/-3/0/781/90          24 WNW
5/12 63/45/54/-2/0/696/80          22 ENE
5/13 70/45/58/+2/0/732/84          31 SSE   AERO 29 MPH SSE
5/14 62/47/55/-2/0.10/166/19       53 S     AERO 52 MPH S
5/15 76/54/65/+8/0/474/54          38 S     AERO 38 MPH S
5/16 68/54/61/+4/T/457/52          35 S     AERO 35 MPH S
5/17 61/49/55/-2/0.09/009/01       35 WNW   AERO 33 MPH WNW
5/18 53/42/48/-10/0.04/168/19      27 NE   
5/19 70/42/56/-2/0/813/92          28 S 
5/20 82/49/66/+8/0/771/87          31 SSW
5/21 89/59/74/+15/0/870/98         37 S     AERO 34 MPH S
5/22 87/59/73/+14/0/739/83         31 N
5/23 65/50/58/-1/T/428/48          28 NE
5/24 80/50/65/+5/1.07/536/60       25 WNW   TSTM TRACE DIME SIZE HAIL
5/25 76/51/64/+4/0/868/97          32 N 
5/26 58/46/52/-8/0/.../..          28 NNE
 
5/27 our morning low temp: 45F; the normal low is now 50F  
 
NEW DAILY RECORDS FOR MAY 2009...
5/14: RECORD PEAK WIND GUST 53 MPH S;
      surpasses previous record of 50 MPH SW in 1976
 
DAILY EXTREMES
 
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):
 
RECORDS FOR MAY 27
HIGH 92F IN 1914
LOW 36F IN 1915
PRECIP 1.40 INS IN 1898
PEAK GUST 55 S IN 1956
 
RECORDS FOR MAY 28
HIGH 90F IN 1929
LOW 39F IN 1917
PRECIP 2.48 INS 1906
PEAK GUST 51e MPH NE IN 1946
 
TODAY'S REPORT PREPARED BY: Robert Skilling