BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA
 
DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 26, 2009   
ALL TIMES ARE IN EASTERN STANDARD TIME
 
HIGH CLOUDS ON THE INCREASE TODAY
MUCH COOLER TEMPERATURES WITH NORTHEAST WINDS
 
High cirrus cloudiness was thickening by this
afternoon well ahead of a warm front draped
east to west across the Middle Atlantic states.
A veering wind overnight from northwest to north-
east has brought much cooler temperatures, which
fell to 46F this morning. It rose to the
upper 50's today despite the bright morning
sunshine, which was becoming dimmed early this
afternoon by the high clouds.
 
Today's observations:
 
7 A.M.  
Weather: Clear, few cirrus 
Temperature: 50F, Dew point: 33F, Wind: ENE at 12G20 kts,
Wind: Direction variable NNE to E 
Sea-level pressure: 30.32 inches Hg, rising
Visibility: 55 miles, NW 70 miles
6-hour minimum temp: 46F
24-hour precipitation: 0.00
BHO SA 1155 CLR 55 268/50/33/0612G20/032/ FEW CI VSBY NW 70
WND 02V09/ 8/001 51019 10051 20046
 
10 A.M.  
Weather: High thin broken cirrus 
Temperature: 55F, Dew point: 30F, Wind: ENE at 9 kts,
Wind: Direction variability NNE to E
Sea-level pressure: 30.34 inches Hg, falling
Visibility: 60 miles, NW 70 miles  
BHO SA 1455 250 –SCT 300 –BKN 60 274/55/30/0609/034/ VSBY NW 70
WND 02V09/ 8/001 50006
 
1 P.M.  
Weather: High dense scattered cirrus layer increasing,
high overcast cirrus with thin spots in overcast to the
northwest thru northeast thru southeast halo past hour
Temperature: 57F, Dew point: 34F, Wind: E at 6 kts
Sea-level pressure: 30.31 inches Hg, falling
Visibility: 60 miles, northwest 70 miles
6-hour maximum temp: 58F    
BHO SA 1755 220 SCT E250 OVC 55 264/57/34/0906/031/ DENS CI LYR
XCPT N-E THN SPTS IOVC NW-ESE HALO PST HR/ 8/006 58010 10058 20050   
 
WEATHER SUMMARY FOR MONDAY, MAY 25, MEMORIAL DAY
 
TEMPERATURE (DEGREES F)
MAX.....76    NORMAL.....70
MIN.....51    NORMAL.....50
MEAN....64    NORMAL.....60
 
DEPARTURE FROM 30-YEAR NORMAL...........+4
TOTAL DEPARTURE FOR THE MONTH..........+77 [+2.9 DEGREES/DAY]
 
HEATING DEGREE DAYS
TOTAL HEATING UNITS FOR YESTERDAY.............1  DEPARTURE.......-5
TOTAL HEATING UNITS FOR THE MONTH...........165  DEPARTURE......-73
TOTAL HEATING UNITS FOR THE SEASON.........6061  DEPARTURE.....-203
TOTAL HEATING UNITS LAST SEASON TO DATE....5886  DIFFERENCE....+175
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY.............32 N  AT 10:31 P.M. 
                   AEROVANE..............28 N  AT 10:31 P.M. 
                   ASOS..................30 N  AT 10:31 P.M.  
                   DAVIS.................30 N  AT 10:30 P.M. 
FASTEST MILE FOR YESTERDAY...............18 N  AT 10:32 P.M. 
MAXIMUM 2-MINUTE ASOS AVERAGE............18 N  AT 10:32 P.M. 
MAXIMUM 2-MINUTE DAVIS AVERAGE...........21 W  AT  2:36 P.M.  
AVERAGE WIND SPEED AND DIRECTION.......10.1 WNW
                   ASOS.................9.6  
                   DAVIS...............10.5 WNW [300 DEG]
 
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..........3.45  DEPARTURE....+0.40
                         ASOS..............3.45 
TOTAL PRECIPITATION FOR THE YEAR..........18.06  DEPARTURE....-2.94
                         ASOS.............19.13 
 
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/.../..          32 N    
 
5/26 our morning low temp: 46F; 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 26
HIGH 89F IN 1914,1965
LOW 37F IN 1972
PRECIP 1.73 INS IN 2003
SNOWFALL TRACE IN 1967 (Fell as ice pellets in nor'easter)
PEAK GUST 62 MPH NE IN 1967
 
RECORDS FOR MAY 27
HIGH 92F IN 1914
LOW 36F IN 1915
PRECIP 1.40 INS IN 1898
PEAK GUST 55 S IN 1956
 
TODAY'S REPORT PREPARED BY: Robert Skilling