Friday, May 8, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
FRIDAY, MAY 8, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

MAXIMUM OF 74F REACHED BY EARLY MORNING,
WINDS SHIFT, BACK DOOR FRONT ROLLS THROUGH

Friday morning’s temperature began to climb similar
to previous days, until a back door cold front
moved through around 8:30 AM EST. Hazy conditions
at the 7:00 AM EST observation coupled with the thin
fog that moved in off the ocean reduced visibility
from 40 miles at time to 12 miles during the morning.

By the 1:00 PM EST observation visibility had been
reduced further to 10 miles in all directions with
obscuring haze and fog coming in from off the ocean.
Temperatures had dropped from a maximum of 74F by
the time of the wind shift to a day time minimum of
56F only a little more than an hour later.
PRELIMINARY STATS FOR APRIL 2015

TEMPERATURE, Deg. F
Avg. Max. 55.9 [+0.2] Avg. Min. 38.4 [+0.7] Mean      47.2 [+0.5] Corrected mean: 46.7
Max. for month: 69 on 4/13
Min. for month: 26 on 4/1

HEATING DEGREE DAYS
Total heating units: 528 [-23] Total for the season: 6271 [+236] Total for last season: 6171

PRECIPITATION, Inches
Total: 3.33 [-1.22] Greatest in 24 hrs: N/A

SNOWFALL, Inches
Total: Trace [-3.0] Greatest in 24 hrs: Trace on 4/8

WIND, mph
Avg. uncorrected wind speed: 12.6
Avg. corrected wind speed: 13.0
Prevailing wind direction: NW @ 16%
Peak gust and direction: 54 NW on the 4th

SUNSHINE:
Astronomical total minutes:   12386 / 24083 or 51%
Campbell-Stokes card minutes: 11946 / 23250 or 51%

 

Today’s Observations:

7 A.M.
Weather: Clear, few cirrus distant WNW-SE
Temperature: 64F; Dew Point: 44F; Wind: W at 7 kts,
Sea-level pressure: 30.14 ins. Hg, rising steadily
Visibility: 40 miles, hazy
6-hr Max temp: 64F
6-hr Min temp: 57F
24-hr precip: none
BHO SA 1155 CLR 40 205/64/44/2607/014/ FEW CI DSNT WNW-SE HAZY/
8/001 52010 10064 20057

10 A.M.
Weather: Thin scattered cirrus
Temperature: 59F; Dew Point: 45F; Wind: ENE at 13 kts,
Sea-level pressure: 30.18 ins. Hg, rising, then more quickly
Visibility: 20 miles, except 15 miles NW-NE, thin fog and hazy
BHO SA 1455 250 -SCT 20 220/59/45/0613/018/ VSBY NW-NE 15 MI
THN FG ALQDS HAZY/ 8/001 53015

1 P.M.
Weather: Think broken cirrus
Temperature: 57F; Dew Point: 44F; Wind: ENE at 13G20 kts,
Sea-level pressure: 30.21 ins. Hg, rising, then more slowly
Visibility: 10 miles, hazy and thin fog
6-Hr Max temp: 74F
6-Hr Min temp: 56F
BHO SA 1755 E250 -BKN 10 229/57/44/0613G20/021/ THN FG ALQDS
HAZY/ 8/001 51009 10074 20056
SUMMARY FOR THURSDAY, MAY 7, 2015

TEMPERATURE (DEGREES F)
MAX…..84   NORMAL…..64
MIN…..52   NORMAL…..45
MEAN….68   NORMAL…..55

DEPARTURE FROM 30-YEAR NORMAL………………….+13
TOTAL DEPARTURE FOR THE MONTH………………….+41 [+5.7 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0  DEPARTURE……….-11
TOTAL HEATING UNITS FOR THE MONTH…………..43  DEPARTURE……….-39
TOTAL HEATING UNITS FOR THE SEASON………..6314  DEPARTURE………+197
TOTAL HEATING UNITS LAST SEASON TO DATE……6238  DIFFERENCE………+76

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………29 S     AT   4:53 P.M.
ASOS…………………..32 S     AT   4:53 P.M.
DAVIS………………….31 S     AT   4:53 P.M. RMY 32
FASTEST MILE FOR YESTERDAY………………..24 S     AT   4:51 P.M.*
MAXIMUM 2-MINUTE ASOS AVERAGE……………..24 S     AT   4:53 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….22 S     AT   4:43 P.M.
AVERAGE WIND SPEED AND DIRECTION…………12.0 SW
ASOS…………………12.3
DAVIS………………..10.9 SW [225 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……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.03  DEPARTURE…..-0.84
ASOS……………0.03
TOTAL PRECIPITATION FOR THE YEAR………..17.95  DEPARTURE…..-1.34
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……0.0
TOTAL SNOWFALL FOR THE MONTH……………..0.0  DEPARTURE……0.0
TOTAL SNOWFALL FOR THE SEASON…………..150.8  DEPARTURE….+88.1
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/-1/0.32/0.0/501/65              54 NW  RMY 64  TSTM
4/5  47/30/39/-4/T/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/-6/0.13/0.0/000/00              21 NE  RMY N/A
4/8  41/32/37/-7/0.51/T/000/00                30 ENE RMY 32
4/9  35/32/34/-10/0.38/0.0/000/00             31 ENE RMY 32
4/10 53/35/44/-1/0.07/0.0/000/00              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/-2/1.00/0.0/000/00              36 SE  RMY 40
4/21 67/51/59/+10/0.44/0.0/417/51             30 SSE RMY N/A TSTM
4/22 67/45/56/+7/0.03/0.0/632/77              44 SSW RMY 52
4/23 49/34/42/-8/0.00/0/0/362/44              32 W   RMY N/A
4/24 50/32/41/-9/0.00/0.0/562/68              32 NW  RMY 36
4/25 56/30/43/-7/0.00/0.0/638/77              26 NW  RMY 29
4/26 54/39/47/-4/0.00/0.0/258/31              17 NW  RMY N/A
4/27 56/42/49/-2/0.15/0.0/125/15              30 NW  RMY N/A
4/28 63/39/51/-1/0.10/0.0/527/63              32 NW  RMY 35
4/29 58/46/52/+0/T/0.0/461/55                 24 ENE RMY 22
4/30 60/42/51/-1/0.00/0.0/320/38              21 NE  RMY N/A

PRELIMINARY CLIMATE SUMMARY FOR MAY 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

5/1 52/37/45/-8/0.00/0.0/…/..               21 NE  RMY 20
5/2 63/35/49/-4/0.00/0.0/…/..               20 S   RMY 20
5/3 74/44/59/+6/0.00/0.0/…/..               22 S   RMY 22
5/4 83/47/65/+11/0.00/0.0/…/..              39 SSW RMY 45
5/5 77/56/67/+13/0.03/0.0/…/..              29 SW  RMY N/A
5/6 74/54/64/+10/0.00/0.0/…/..              24 SSW RMY 25
5/7 84/52/68/+13/0.00/0.0/…/..              29 S   RMY 32

5/8 Low since midnight is 57F; normal low now 45F

DAILY RECORDS FOR MAY 2015

NONE SO FAR

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

RECORDS FOR MAY 8
HIGH 89F IN 2000
LOW 29F IN 1956
PRECIP 1.48 INCHES IN 1886
SNOWFALL TRACE IN 1898, 1947
PEAK GUST 68e MPH NNW IN 1943

RECORDS FOR MAY 9
HIGH 93F IN 2000
LOW 31F IN 1947
PRECIP 2.72 INCHES IN 1954
SNOWFALL 5.0 INS IN 1977 (RECORD FOR MAY)
PEAK GUST 70e MPH NE IN 1977

TODAY’S REPORT PREPARED BY: Brian Fitzgerald