Thursday, April 30, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 30, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

CLOUDS AND ISOLATED SHOWERS ENCROACH EARLY,
APRIL COMES TO AN END DRY NEAR NORMAL TEMPS WITHOUT
HITTING 70F

Clouds and showers that have advanced inland along a NE
wind have kept temperatures subdued since yesterday morning.
Yesterday’s maximum of 58F was reached just after 8:00 AM EST,
with winds shifting to the NE thereafter.

By the 1:00 PM EST observation today, temperatures had only
maxed out to 58F. Clouds had largely dissipated overhead, with
three layers of clouds in all other directions.

Cool conditions mean another day without this year’s first
70 degree day. A significant warm up still does not seem
likely this week, possibly inching 2015 closer to the top
10 latest 70 degree readings.

BHO Latest First 70-deg Temperature, (1885-2014)

1) 20 May, 1966
2) 19 May, 1917
3) 14 May, 1924
4) 11 May, 1975
5) 10 May, 1893
6) 7 May, 1971
7) 5 May, 1939
8) 3 May, 1937
3 May, 1904
10) 2 May, 1916
2 May, 1919

Stay tuned for preliminary monthly statistics in tomorrow’s
daily discussion, or visit BlueHill.org

Today’s Observations:

7 A.M.
Weather: Broken stratus, few cumulus fractus distant WSW-SE,
showers distant SE and NW, virga distant ESE-SE
Temperature: 45F; Dew Point: 40F; Wind: ENE at 7 kts,
Sea-level pressure: 29.86 ins. Hg, increasing, then more quickly
Visibility: 70 miles, except 25 miles NW, obscured by showers
6-hr Max temp: 48F
6-hr Min temp: 44F
24-hr precip: Trace
BHO SA 1155 E50 BKN 70 112/45/40/0607/986/ VSBY NW 25 MI
SHWRS DSNT SE AND NW VIRGA DSNT ESE-SE FEW CUFRA WSW-SE/
8/600 53018 10048 20044

10 A.M.
Weather: Broken altocumulus, few cumulus/stratocumulus
in all direction, few altocumulus lenticularis distant N-E
Temperature: 51F; Dew Point: 37F; Wind: NE at 9 kts,
Sea-level pressure: 29.88 ins. Hg, increasing, then more slowly
Visibility: 70 miles, except 50 SSE-NW
BHO SA 1455 E60 BKN 70 120/51/37/0409/988/ VSBY SSE-NW 50 MI
FEW CU/SC ALQDS FEW ACSL DSNT N-E/ 8/530 51008

1 P.M.
Weather: Scattered stratocumulus, scattered altocumulus,
scattered cirrus
Temperature: 57F; Dew Point: 37F; Wind: NE at 7G15 kts,
Sea-level pressure: 29.86 ins. Hg, rising then falling and lower
Visibility: 70 miles
6-hr Max temp: 58F
6-hr Min temp: 43F
BHO SA 1755 50 SCT 70 SCT 250 SCT 70 113/57/37/0407G15/986/
8/531 58007 10058 20043

SUMMARY FOR WEDNESDAY, APRIL 29, 2015

TEMPERATURE (DEGREES F)
MAX…..58   NORMAL…..61
MIN…..46   NORMAL…..43
MEAN….52   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL…………………..+0
TOTAL DEPARTURE FOR THE MONTH………………….+21 [+0.5 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..13  DEPARTURE………..+0
TOTAL HEATING UNITS FOR THE MONTH………….514  DEPARTURE……….-24
TOTAL HEATING UNITS FOR THE SEASON………..6257  DEPARTURE………+235
TOTAL HEATING UNITS LAST SEASON TO DATE……6147  DIFFERENCE……..+110

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………24 ENE   AT   9:58 A.M.
ASOS…………………..24 E     AT   9:59 A.M.
DAVIS………………….22 ENE   AT  10:48 A.M. RMY 22
FASTEST MILE FOR YESTERDAY………………..17 ENE   AT  10:02 A.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..18 ENE   AT  10:49 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….16 ENE   AT  10:48 A.M.
AVERAGE WIND SPEED AND DIRECTION………….9.6 NW
ASOS………………….9.8
DAVIS…………………8.7 NNE [021 degrees] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….TRACE  DEPARTURE…..-0.13
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..3.33  DEPARTURE…..-1.09
ASOS……………3.29
TOTAL PRECIPITATION FOR THE YEAR………..17.92  DEPARTURE…..-0.37
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……………TRACE  DEPARTURE…..-3.0
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
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 56/30/43/-7/0.00/0.0/…/..              26 NW  RMY 29
4/26 54/39/47/-4/0.00/0.0/…/..              17 NW  RMY N/A
4/27 56/42/49/-2/…./0.0/…/..              30 NW  RMY N/A
4/28 63/39/51/-1/…./0.0/…/..              32 NW  RMY 35
4/29 58/46/52/+0/T/0.0/…/..                 24 ENE RMY 22

4/30 Low since midnight is 44F, normal low is 43F

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 30
HIGH 86 IN 1942
LOW 30 IN 1931
PRECIP 1.41 IN 1991
SNOWFALL 0.3 IN. IN 1909
PEAK GUST 64e MPH NW IN 1978

RECORDS FOR MAY 1
HIGH 87F IN 1899
LOW 29F IN 1978
PRECIP 2.53 INCHES IN 1921
SNOWFALL TRACE IN 1905,1917,1921,1995
PEAK GUST 57 MPH NW IN 1974

TODAY’S REPORT PREPARED BY: Brian Fitzgerald