Saturday, April 25, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, APRIL 25, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

UNSEASONABLY COLD LATE APRIL WEATHER CONTINUES
LOW TEMPERATURE OF 30F THIS MORNING AFTER 32F YESTERDAY
THE LOW OF 30F THIS MORNING IS 11 DEG. COLDER THAN AVERAGE
BRIGHT SUNSHINE WITH JUST FEW CLOUDS AND VISIBILITY 70-75 MILES
FROM THE SUMMIT THIS MORNING–W-NW WINDS CONTINUE TO DIMINISH

This morning’s low temperature of 30.1F (30F) was the second
consecutive morning minimum temperature. It fell 11 degrees
colder than the average low of 41F for this date.

The average date for the last spring freeze at the summit is
April 20. The record low for this date is 24F in 1892.

Still awaiting our first 70-degree reading of the year; could rank
among the top ten latest I would think.

Today’s Observations:

7 A.M.
Weather: Clear, altocumulus/altocumulus lenticularis mostly distant
to the NW-E
Temperature: 37F; Dew Point: 23F; Wind: W at 10 kts,
Sea-level pressure: 29.78 ins. Hg, rising slightly
Visibility: 70 miles, light distant haze
6-hr Max temp: 37F
6-hr Min temp: 30F
24-hr precip: 0.00 inch
BHO SA 1155 CLR 70 086/37/23/2810/978/ AC/ACSL MSTLY DSNT
NW-E LGT DSNT HZ/ 50006 8/040 10037 20030

10 A.M.
Weather:  Clear, cumulus fractus/cumulus distant WNW-N,
altocumulus distant NW-NE, few lenticulars NW-ESE
Temperature: 45F; Dew Point: 24F; Wind: W at 14 kts,
Sea-level pressure: 29.75 ins. Hg, decreasing then more rapidly
Visibility: 75 miles, light distant haze
BHO SA 1455 CLR 75 074/48/24/2814/975/ CUFRA/CU FRMG DSNT
WNW-N AC DSNT NNW-NE FEW ACSL NNW-ESE LGT DSNT HZ/
8/140 58012

1 P.M.
Weather: Broken stratucumulus generated by cumulus with a
few cumuloform tops
Temperature: 53F; Dew Point: 26F; Wind: NW at 9 kts,
Wind: Direction variable W-N
Sea-level pressure: 29.71 ins. Hg, decreasing then more slowly
Visibility: 80 miles
6-hr Max temp: 55F
6-hr Min temp: 37F
BHO SA 1755 E55 BKN 80 060/53/26/3109/971/ SC FEW CU TOPS
SCCG ALQDS WND 28V01/ 8/400 56014 10055 20037

SUMMARY FOR FRIDAY, APRIL 24, 2015

TEMPERATURE (DEGREES F)
MAX…..50   NORMAL…..59
MIN…..32   NORMAL…..41
MEAN….41   NORMAL…..50

DEPARTURE FROM 30-YEAR NORMAL…………………..-9
TOTAL DEPARTURE FOR THE MONTH………………….+35 [+1.3 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..24  DEPARTURE………..+9
TOTAL HEATING UNITS FOR THE MONTH………….431  DEPARTURE……….-37
TOTAL HEATING UNITS FOR THE SEASON………..6174  DEPARTURE………+222
TOTAL HEATING UNITS LAST SEASON TO DATE……6044  DIFFERENCE……..+130

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………32 NW    AT   7:30 A.M.
ASOS…………………..34 NW    AT   7:31 A.M.
DAVIS………………….32 NW    AT   7:30 A.M. RMY 36
FASTEST MILE FOR YESTERDAY………………..26 WNW   AT   7:31 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..24 WNW   AT   7:32 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….23 WNW   AT   7:32 A.M.
AVERAGE WIND SPEED AND DIRECTION………….15.7 WNW
ASOS………………….15.2
DAVIS…………………13.5 WNW [300 degrees] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.13
ASOS……………0.03
TOTAL PRECIPITATION FOR THE MONTH………..3.08  DEPARTURE…..-0.67
ASOS……………3.05
TOTAL PRECIPITATION FOR THE YEAR………..17.67  DEPARTURE…..+0.05
ASOS…………….N/A ***
*** ASOS annual totals not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M………..0.0  DEPARTURE……0.1
TOTAL SNOWFALL FOR THE MONTH……………TRACE  DEPARTURE…..-2.9
TOTAL SNOWFALL FOR THE SEASON…………..150.8  DEPARTURE….+88.2

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY GUST
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized

4/1  44/26/35/-6/0.00/0.0/748/98              30 WNW RMY 31
4/2  59/29/44/+3/T/0.0/375/49                 39 SSW RMY 43
4/3  56/47/52/+10/0.02/0.0/000/00             36 SW  RMY N/A
4/4  49/32/41/-1/…./0.0/501/65              54 NW  RMY 64
4/5  47/30/39/-4/…./0.0/464/60              40 W   RMY 45
4/6  48/33/41/-2/0/00/0.0/544/70              18 NE  RMY N/A
4/7  39/34/37/-6/…./0.0/000/00              21 NE  RMY N/A
4/8  41/32/37/-7/…./T/000/00                30 ENE RMY 32
4/9  35/32/34/-10/…./0.0/000/00             31 ENE RMY 32
4/10 53/35/44/-1/…./0.0/000/00              31 SW  RMY N/A
4/11 56/38/46/+1/0.00/0.0/744/94              39 WNW RMY 48
4/12 68/35/52/+7/0.00/0.0/762/96              23 WNW RMY 23
4/13 69/47/58/+12/0.00/0.0/764/96             35 SSW RMY N/A
4/14 65/51/58/+12/0.05/0.0/072/09             37 SSW RMY N/A
4/15 67/45/56/+9/0.00/0.0/786/98              32 NW  RMY 33
4/16 64/42/53/+6/0.00/0.0/765/95              31 S   RMY 21
4/17 64/45/55/+8/0.05/0.0/065/08              31 SSW RMY 32
4/18 64/43/54/+6/0.00/0.0/770/95              31 N   RMY 36
4/19 55/39/47/-1/0.00/0.0/724/89              25 NNW RMY N/A
4/20 55/38/47/-2/…./0.0/000/00              36 SE  RMY 40
4/21 67/51/59/+10/…./0.0/417/51             30 SSE RMY N/A
4/22 67/45/56/+7/0.03/0.0/…/..              44 SSW RMY 52
4/23 49/34/42/-8/0.00/0/0/…/..              32 W   RMY N/A
4/24 50/32/41/-9/0.00/0.0/…/..              32 NW  RMY 36

4/25 low since midnight is 30F normal low is 41F

DAILY RECORDS FOR APRIL 2015

4/3 – NEW RECORD DAILY HIGH MINIMUM TEMPERATURE: 47F
surpasses the previous record of 46F in 1892

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

RECORDS FOR APRIL 25
HIGH 83 IN 2009
LOW 24 IN 1892
PRECIP 1.38 IN. IN 1901
SNOWFALL 0.7 IN. IN 2002.
PEAK GUST 66 MPH SE IN 1968

RECORDS FOR APRIL 26
HIGH 88 IN 2009
LOW 23 IN 1919
PRECIP 1.64 IN. IN 1931
SNOWFALL 1.0 IN. IN 2000
PEAK GUST 53 MPH SSW IN 1996

TODAY’S REPORT PREPARED BY:  Robert Skilling