Tuesday, May 5, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, MAY 5, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

FIRST 80 DEGREE DAY MONDAY IS FOLLOWED UP BY
WARM OVERNIGHT AND LIGHT SHOWERS TUESDAY MORNING

Temperatures skyrocketed yesterday following an overnight
low of 47F. Temperatures climbed to an afternoon maximum of
83F, creating a remarkable temperature range of 36 degrees
in less than 12 hours.

Overnight temperatures fell only to 63F, and continued to
drop as light rain showers and a weak cold front moved
through the region. The low temperature this morning was
warmer than the existing record high minimum temperature
for May 5 of 59F set in 1887 and 1949, though it may get
colder than this before the end of the day today.

By the 1:00 PM EST observation sun had returned along with
warming temperatures, hitting a maximum of 73F. Hazy conditions
had reduced visibility to just 30 miles in all directions.
Showers this morning totaled 0.03 inches of new rain.
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: Light rain showers begin 6:40 AM EST,
broken altocumulus, overcast nimbostratus
Temperature: 65F; Dew Point: 48F; Wind: W at 9 kts,
Sea-level pressure: 30.18 ins. Hg, rising then more quickly
Visibility: 35 miles, except 20 miles WSW-NE, hazy and obscured
by rain showers
6-hr Max temp: 66F
6-hr Min temp: 63F
24-hr precip: Trace
BHO SA 1155 E110 BKN 150 OVC 35RW- 221/65/48/2609/018/ RW-B40
VSBY WSW-NE 20 MI HAZY PRCP VRY LGT/ 8/02/ 53022 MANUAL 6000/
10066 20063

10 A.M.
Weather: Showers distant ENE-ESE and SW-WNW, few cumulus WNW-NNE,
overcast altostratus
Temperature: 62F; Dew Point: 56F; Wind: estimated SW at 4 kts,
Wind Speed: Light
Sea-level pressure: 30.22 ins. Hg, rising, then more quickly
Visibility: 35 miles, except 20 miles SW-WNW, hazy and distant showers
3-hr precip: 0.02 inches
BHO SA 1455 E70 OVC 35 233/62/56/E2304/022/ VSBY SW-WNW 20 MI SHWRS
DSNT ENE-ESE AND SW-WNW FEW CU DSNT WNW-NNE THN FG ALQDS WND LGT/
8/12/ 53012 ASOS 60002 MANUAL 60002

1 P.M.
Weather: Thin broken cirrus, few cumulus in all direction,
few altocumulus lenticularis NNE-ESE
Temperature: 73F; Dew Point: 53F; Wind: estimated SSE at 3 kts,
Wind Speed and Direction: Light and Variable
Sea-level pressure: 30.20 ins. Hg, rising, then falling and lower
Visibility: 30 miles, hazy
6-hr Max temp: 73F
6-hr Min temp: 61F
6-hr precip: 0.03 inches
BHO SA 1755 E270 -BKN 30 228/73/53/E1503/020/ FEW CU ALQDS FEW ACSL
DSNT NNE-ESE HAZY WND LGT AND VRB/ 8/141 58005 ASOS 60003 MANUAL
60003 10073 20061
SUMMARY FOR MONDAY, MAY 4, 2015

TEMPERATURE (DEGREES F)
MAX…..83   NORMAL…..63
MIN…..47   NORMAL…..44
MEAN….65   NORMAL…..54

DEPARTURE FROM 30-YEAR NORMAL………………….+11
TOTAL DEPARTURE FOR THE MONTH…………………..+5 [+1.1 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………0  DEPARTURE……….-12
TOTAL HEATING UNITS FOR THE MONTH…………..42  DEPARTURE………..-7
TOTAL HEATING UNITS FOR THE SEASON………..6313  DEPARTURE………+230
TOTAL HEATING UNITS LAST SEASON TO DATE……6206  DIFFERENCE……..+107

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………39 SSW   AT   4:33 P.M.
ASOS…………………..46 SSW   AT   4:33 P.M.
DAVIS………………….45 SSW   AT   5:28 P.M. RMY 45
FASTEST MILE FOR YESTERDAY………………..36 SSW   AT   4:34 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..36 SSW   AT   4:34 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….34 SSW   AT   4:34 P.M.
AVERAGE WIND SPEED AND DIRECTION…………16.3 SSW
ASOS…………………16.1
DAVIS………………..15.1 SSW [202 degrees] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….TRACE  DEPARTURE…..-0.12
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..0.00  DEPARTURE…..-0.49
ASOS……………0.00
TOTAL PRECIPITATION FOR THE YEAR………..17.92  DEPARTURE…..-0.99
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/…./0.0/501/65              54 NW  RMY 64  TSTM
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 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/…./0.0/125/15              30 NW  RMY N/A
4/28 63/39/51/-1/…./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 Low since midnight is 63F; 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 5
HIGH 92F IN 1949
LOW 30F IN 1891
PRECIP 2.74 INCHES IN 1922
SNOWFALL 3.0 INCHES IN 1917
PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976

RECORDS FOR MAY 6
HIGH 90F IN 1930
LOW 29F IN 1891
PRECIP 1.04 INCHES IN 1890
SNOWFALL TRACE IN 1917,1996
PEAK GUST 65 MPH SSE IN 1989

TODAY’S REPORT PREPARED BY: Brian Fitzgerald