Wednesday, April 29, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
WEDNESDAY, APRIL 29, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

Considerable cloudiness prevails again today. A maximum temperature
of 58 deg. occurred just before a sea breeze started at 9 A.M. EDT.

The barometric pressure has continued quite low
now for 9 days averaging around 980 mbs. station pressure and
about 29.65 inches for sea level as a very slow moving low pressure
system moved southeast from eastern Canada into the Atlantic to
our east.

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

Today’s Observations:

7 A.M.
Weather: Scattered dense cirrus  [2 layers mostly NNE-ESE] scattered cirrus,altocumulus lenticularis NNW-E-S
Temperature: 54F; Dew Point: 36F; Wind: NNW at 9 kts,
Sea-level pressure: 29.65 ins. Hg, increasing, then more quickly
Visibility: 70 miles, except 25 miles, hazy, NE, 75 miles, light
distant haze NW
6-hr Max temp: 54F
6-hr Min temp: 46F
24-hr precip: 0.00 inch
BHO SA 1155 200 SCT 220 SCT 250 SCT 70 039/54/36/3309/965/ ACSL
NNW-E-S DNS CI N-E MSTLY CLR SKY SW-NW VSBY NE 25 HZY NW 75 LGT
DSNT HZ/ 8/042 53011 10054 20046

10 A.M.
Weather: Scattered altocumulus/lenticularis/chaotic sky/scattered
dense cirrus, broken dense cirrus, cumulus forming ESE-S and
distant SW-WNW, stratocumulus SW-N
Temperature: 54F; Dew Point: 38F; Wind: E at 14G19 kts,
Sea-level pressure: 29.68 ins. Hg, increasing, then more slowly
Visibility: 65 miles, except 70 NW, 30 miles NE, virga distant NW
BHO SA 1455 70 SCT 90 SCT 150 SCT 200 SCT E220 BKN 65 051/54/38/
0814G19/968/ CU FRMG ESE-S AND DSNT SW-WNW SC SW-N AC CHAOTIC/ACSL
ALQDS DNS CI ALQDS VIRGA DSNT NW VSBY NW 70 NE 30 HAZY/ 8/892 51012

1 P.M.
Weather: Scattered stratocumulus, broken altocumulus, overcast
dense cirrus, (2 levels), few cumulus distant W-NW, small break
in overcast, few thin spots in overcast,
Temperature: 54F; Dew Point: 37F; Wind: E at 7 kts,
Wind: Direction variability ENE-ESE
Sea-level pressure: 29.70 ins. Hg, rising then falling slightly
Visibility: 70 miles light distant haze
6-hr Max temp: 58F
6-hr Min temp: 49F
BHO SA 1755 65 SCT E85 BKN 200 BKN 220 OVC 70 057/54/37/0807/970/
CU DSNT W-NNW FEW SML BINOVC/THN SPTS IOVC LGT DSNT HZ WND 06V11/
8/872 50006 10058 20049

SUMMARY FOR TUESDAY, APRIL 28, 2015

TEMPERATURE (DEGREES F)
MAX…..63   NORMAL…..61
MIN…..39   NORMAL…..42
MEAN….51   NORMAL…..52

DEPARTURE FROM 30-YEAR NORMAL…………………..-1
TOTAL DEPARTURE FOR THE MONTH………………….+21 [+0.6 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY…………..14  DEPARTURE………..+2
TOTAL HEATING UNITS FOR THE MONTH………….501  DEPARTURE……….-24
TOTAL HEATING UNITS FOR THE SEASON………..6244  DEPARTURE………+235
TOTAL HEATING UNITS LAST SEASON TO DATE……6122  DIFFERENCE……..+122

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY………………32 NW    AT   5:55 P.M.
ASOS…………………..37 NW    AT   5:55 P.M.
DAVIS………………….32 NW    AT   5:49 P.M. RMY 35
FASTEST MILE FOR YESTERDAY………………..26 NW    AT   5:54 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE……………..26 NNW   AT   3:28 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE…………….22 NW    AT   5:54 P.M.
AVERAGE WIND SPEED AND DIRECTION………….14.4 NW
ASOS………………….13.8
DAVIS…………………12.0 N [350 degrees] * Last of several occurrences…

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.00  DEPARTURE…..-0.14
ASOS……………0.00
TOTAL PRECIPITATION FOR THE MONTH………..3.33  DEPARTURE…..-0.96
ASOS……………3.29
TOTAL PRECIPITATION FOR THE YEAR………..17.92  DEPARTURE…..-0.24
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 Low since midnight is 46F, 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 29
HIGH 85 IN 1974
LOW 26 IN 1909
PRECIP 1.65 IN 1923
SNOWFALL 1.0 IN. IN 1987
PEAK GUST 55 MPH WNW IN 2010

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

TODAY’S REPORT PREPARED BY: Robert Skilling