BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS 02186
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
MONDAY, APRIL 18, 2005 PATRIOTS DAY
ALL TIMES EASTERN DAYLIGHT TIME UNLESS OTHERWISE NOTED

TODAY'S DISCUSSION.....AT 2 P.M.

RELATIVE HUMIDITY DIPS TO 14% FOR 2ND DAY IN A ROW!

We are continuing to record very dry conditions again today
with the relative humidities dropping below 20% for the fourth
consecutive day.  The month is averaging about 3 degrees
warmer than normal daily and our total precipitation of just
over 2 inches is now one half drier than normal.

TODAY'S OBSERVATIONS

4/18/2005 MON PATRIOTS DAY

8 a.m. high thin scattered clouds with 60 miles visibility
and temp. 56; dewpoint 31; wind nnw at 09 mph; six hourly
min. temp. 51 deg.

BHO SA 1155 300 -SCT 60 187/56/31/3308/008/ LWR CI W-N THN HZ ALQDS
VSBY NW 70/ 8/001 51026 10057 20051

11 a.m. high thin broken clouds with 80 miles visibility;
temp. 63; dewpoint 24; rel. humidity 22%....

BHO SA 1455 250 -SCT 300 -BKN 80 197/63/24/3110G18/011/ WND 27V01/ 8/001 51010

2 p.m. high thin scattered ci clouds with 90 miles visibility;
temp. 66; dewpoint 16 deg; rel. humidity 14%!; wind nnw at 09 mph but
variable wnw to nne; six hourly max. temp. 67

BHO SA 1755 300 -SCT 90 186/66/16/3308/008/ WND 29V03/ 8/001 57011 10067 20056

WEATHER SUMMARY FOR SUNDAY APRIL 17:

TEMPERATURE (DEGREES F)
MAX.....74    NORMAL.....56   HAZEN 74.1 @  5:06 p.m.
MIN.....37    NORMAL.....38   HAZEN 37.0 @  6:20 a.m.
MEAN....56    NORMAL.....47

DEPARTURE FROM 30-YEAR NORMAL......+  9
TOTAL DEPARTURE FOR THE MONTH......+ 54 (+3.0 DEGREES/DAY)

PRECIPITATION (INCHES) THROUGH THIS MORNING
TOTAL PRECIPITATION 24 HRS ENDING 8 A.M....0.00    DEPARTURE....-0.15
                         ASOS..............0.00
TOTAL PRECIPITATION FOR THE MONTH..........2.04    DEPARTURE....-0.49
                         ASOS..............2.04
TOTAL PRECIPITATION FOR THE YEAR..........18.50   DEPARTURE.....+2.49
TOTAL FOR ASOS FOR THE YEAR...............17.52

SNOWFALL (INCHES) THROUGH THIS MORNING
TOTAL SNOWFALL 24 HRS ENDING 8 A.M........  0.0   DEPARTURE....- 0.1
TOTAL SNOWFALL FOR THE MONTH..............  0.2   DEPARTURE....- 1.6
TOTAL SNOWFALL FOR THE SEASON.............119.4   DEPARTURE.....+60.4

YESTERDAY'S PEAK GUSTS AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY........23 WNW  AT  3:22 P.M.
                   AEROVANE.........23 WNW  AT  3:22 P.M.
                   ASOS.............21 SE   AT  7:03 P.M.
                   DAVIS............24 WNW  AT  3:05 P.M.
FASTEST MILE FOR YESTERDAY......... 16 WSW AT  6:02 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE.......17 SE  AT  7:04 P.M.
MAXIMUM 1-MINUTE DAVIS AVERAGE......19 WNW AT  3:07 P.M.
OUR AVERAGE SPEED AND DIRECTION..... 9.1  WNW
ASOS AVERAGE AND DIRECTION..........10.1  W   [280 deg]
DAVIS AVERAGE AND DIRECTION......... 9.3  WSW [250 deg]

THE PRELIMINARY CLIMATE SUMMARY FOR APRIL 2005......
CALENDAR DAY DATA DATA REPORTED HERE ENDING MIDNIGHT STANDARD TIME
DATE  MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST
AERO: Aerovane recording wind system when significant
TSTM: Thunderstorm day
....: Data not yet available

4/1   56/36/46/+5/0.01/0/283/37           23 MPH SE
4/2   56/35/46/+4/1.04/0/000/00           53 MPH SE
4/3   53/39/46/+4/0.63.0/254/33           54 MPH SE  Aero 55 MPH SE
4/4   52/37/45/+3/0.01/0/131/17           32 MPH W
4/5   63/35/49/+6/0/0/721/93              32 MPH WNW Aero 35 MPH WNW
4/6   66/43/55/+12/0/0/591/76             25 MPH S
4/7   70/44/57/+14/0.07/0/164/21          46 MPH SSW
4/8   56/43/50/+6/0.25/0/212/27           32 MPH NW
4/9   58/39/49/+5/0/0/786/100             22 MPH NW
4/10  70/39/55/+11/0/0/742/94             38 MPH NNE
4/11  48/36/42/-3/0/0/744/94              32 MPH NNE
4/12  48/28/38/-7/0.03/0.2/413/52         32 MPH NE
4/13  50/28/39/-6/0/0/427/78              22 MPH WNW
4/14  50/36/43/-3/0/0/.../..              23 MPH WNW
4/15  48/34/41/-5/0/0/.../..              35 MPH NE
4/16  55/35/45/-1/0/0/.../..              22 MPH ESE
4/17  74/37/56/+9/0/0/.../..              23 MPH WNW

4/18  morning low temp. 51 deg.

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

RECORDS FOR APRIL 18
HIGH 92 IN 1976
LOW 23 1887
PRECIP 1.48 IN 1954
SNOWFALL 3.7 IN. IN 1965
PEAK GUST 59 MPH S IN 1982

RECORDS FOR APRIL 19
HIGH 94 IN 1976 [RECORD FOR MONTH]
LOW 21 IN 1890
PRECIP 1.71 IN 1969
SNOWFALL 6.0 IN. IN 1887
PEAK GUST 66 MPH E IN 1984

TODAY'S REPORT BY: Robert Skilling