Saturday, September 12, 2015

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

DAILY DISCUSSION AND CLIMATE SUMMARY
SATURDAY, SEPTEMBER 12, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

MEASURABLE RAINFALL TOTALS 0.91 IN FIRST RAIN EVENT OF MONTH
FIRST MEASURABLE RAINFALL SINCE AUGUST 23-24TH
LOTS OF MOISTURE LEFT BEHIND AFTER THE RAIN RESULTED IN DENSE FOG
EARLY TODAY

BLUE HILL OBSERVATORY ASKS FOR YOUR SUPPORT
FOR OUR KICKSTARTER FUNDRAISER FOR A NEW
AEROVANE ANEMOMETER- PLEASE SUPPORT BY VISITING:

The first rainfall of September left almost an inch (0.91) by the time
it ended at late morning yesterday.  It was a very badly needed precipitation
event since the last rainfall was way back on August 23-24. Considerable
moisture has been left behind the rainstorm and so the formation of low
clouds and dense fog, especially here at the summit, dropped our visibility
down to 1/16 mile by 8 A.M. EDT observation time this morning.
Winds have been light under 10 MPH since noon on Friday.

Today’s Observations:

7 A.M.
Weather: Obscurement dense fog, heavy condensation all surfaces
Temperature: 60F; Dew Point: 60F; Wind: SSE at 5 kts,
Sea-level pressure: 29.88 ins. Hg, falling, then rising and higher
Visibility: 1/16 of a mile, dense fog
6-hr Min temp: 58F
24-hr precip: 0.06 in.
BHO SA 1155 W2 X 1/16F 118/60/60/1505/988/ HVY CONDENSATION/
ALL SFCS/ 8//// 51008 ASOS 70007 MANUAL 70006 10062 20058

10 A.M.
Weather: Broken stratocumulus
Temperature: 68F; Dew Point 63F; Wind: S at 3 kts, estimated,
Wind: Light and variable w
Sea-level pressure: 29.89 ins. Hg, rising, then falling slightly
Visibility: 15 miles, except 20 miles NE-S, hazy
BHO SA 1455 E7 BKN 15 123/68/63/E1803/989/ VSBY NE-S 20 HAZY
WND L/V/ 8/500 50005

1 P.M.
Weather: Scattered cumulus, moderate cumulus except NE, few pathces
of altocumulus of chaotic sky, patches dense cirrus
Temperature: 72F; Dew Point: 61F; Wind: ENE at 3 kts, estimated
Sea-level pressure: 29.86 ins. Hg, falling, then more rapidly
Visibility: 60 miles, except 70 miles NW, light distant haze M
6-hr Max: 74F
6-hr Min: 60F
6-hr precip: 0.00 inch
BHO SA 1755 26 SCT 150 SCT 220 SCT 250 BKN 60 113/72/61/0703/986/
CU/MDT CU XCPT NE FEW SML PTCHS CHAOTIC AC PTCHS DNS CI ALQDS VSBY NW 70
LGT DSNT HZ WND LGT/ 8/292 58010 10074 20060

SUMMARY FOR FRIDAY, SEPTEMBER 11, 2015

TEMPERATURE (DEGREES F)
MAX…..70   NORMAL…..73
MIN…..59   NORMAL…..56
MEAN….68   NORMAL…..65

DEPARTURE FROM 30-YEAR NORMAL…………………….0
TOTAL DEPARTURE FOR THE MONTH…………………..+73  [+6.4 DEGREES/DAY]

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY……………0   DEPARTURE……….-2
TOTAL COOLING UNITS FOR THE MONTH…………..90   DEPARTURE………+55
TOTAL COOLING UNITS FOR THE SEASON…………756   DEPARTURE……..+184
TOTAL COOLING UNITS LAST SEASON TO DATE…….565   DIFFERENCE…….+191

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….33  NNE AT  5:38 A.M.
ASOS……………………36  NNE AT  5:38 A.M.
DAVIS…………………..34  NE  AT  5:37 A.M. RMY N/A
FASTEST MILE FOR YESTERDAY……………….. 23  NE  AT  1:21 A.M
MAXIMUM 2-MINUTE ASOS AVERAGE………………23  NE  AT  1:20 A.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..22  NE  AT  1:20 A.M.
AVERAGE WIND SPEED AND DIRECTION………….. 9.7 NNE
ASOS……………………9.1
DAVIS…………………..8.7 NE  [040 DEG]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M…..0.06  DEPARTURE…..-0.07
ASOS……………0.07
TOTAL PRECIPITATION FOR THE MONTH………..0.91  DEPARTURE…..-0.44
ASOS……………0.91
TOTAL PRECIPITATION FOR THE YEAR………..31.17  DEPARTURE…..-5.20
ASOS…………….N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR SEPTEMBER CALENDAR DAY DATA
DATA REPORTED:
DATE: MAX/MIN/MEAN/DEP/PRECIP/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

9/1  81/65/73/+5/0.00/…/..               20 SSW RMY 20
9/2  89/64/77/+9/0.00/…/..               20 SW  RMY 21
9/3  85/66/76/+9/T/…/..                  17 E   RMY N/A TSTM
9/4  72/58/65/0/0.00/…/..                31 ENE RMY N/A
9/5  77/55/66/-1/0.00/…/..               14 SW  RMY 18
9/6  87/57/72/+5/0.00/…/..               21 SSW RMY 22
9/7  92/63/78/+12/0.00/…/..              23 WSW RMY 24
9/8  97/70/84/+18/0.00/…/..              22 WSW RMY 24
9/9  92/70/81/+15/0.00/…/..              30 SSW RMY 33
9/10 73/62/68/+3/…./…/..               29 NE  RMY N/A
9/11 70/59/65/0/…./…/..                33 NE  RMY N/A

9/12 low since midnight is 58F; normal low is now 56F

DAILY RECORDS FOR SEPTEMBER 2015

**9/7 DAILY RECORD MAXIMUM TEMPERATURE OF 92F
TIES PREVIOUS RECORD SET IN 2007**

**9/8 DAILY RECORD MAXIMUM TEMPERATURE OF 97F
BREAKS PREVIOUS RECORD OF 93F SET IN 2007**

**9/8 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F
BREAKS PREVIOUS RECORD OF 69F SET IN 1999**

**9/9 DAILY RECORD MAXIMUM TEMPERATURE OF 92F
BREAKS PREVIOUS RECORD OF 91F SET IN 2002**

**9/9 DAILY RECORD HIGH MINIMUM TEMPERATURE OF 70F
BREAKS PREVIOUS RECORD OF 69F SET IN 1999**

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

RECORDS FOR SEPTEMBER 12
HIGH 92F IN 1961
LOW 42F IN 1958,1967,1985
PRECIP 2.79 INCHES IN 1960 (HURRICANE DONNA)
PEAK GUST 140 MPH SSE IN 1960 (HURRICANE DONNA)

RECORDS FOR SEPTEMBER 13
HIGH 91F IN 1957
LOW 40F IN 1985
PRECIP 3.10 INCHES IN 1987
PEAK GUST 44 MPH WNW IN 1986

TODAY’S REPORT PREPARED BY: Robert Skilling