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

DAILY DISCUSSION AND CLIMATE SUMMARY
TUESDAY, AUGUST 18, 2015
ALL TIMES ARE IN EASTERN STANDARD TIME

HUMIDITY BUILDS ALONG WITH HEAT, TEMPS REACH
THE 90S BY EARLY AFTERNOON

Temperatures overnight dipped to warmer than normal
low of 70F, with little relief following yesterday
afternoon's maximum reading of 90F.

Light winds and dew points in the upper 60s to low
70s have coupled to produce heat indexes in the mid
90s this afternoon. At the 1:00 PM EST observation 
temperatures had reached 92F with a relative humidity
of 47%, making for a heat index of approximately 96F.
Moderate cumulus were building in all directions with
haze limiting visibility to just 15 miles in all directions.


Today's Observations:

7 A.M.
Weather: Scattered cumulus, moderate cumulus NW
Temperature: 74F; Dew Point: 68F; Wind: estimated SSW at 6 kts
Wind Speed: Light
Sea-level pressure: 30.06 ins. Hg, rising then more slowly 
Visibility: 10 miles, hazy
6-hr Max temp: 74F
6-hr Min temp: 70F
24-hr precip: 0.00 ins.
BHO SA 1155 90 SCT 10 178/74/68/E2106/006/ MDT CU NW HAZY WND LGT/ 
8/200 51006 10074 20070

10 A.M.
Weather: Scattered altocumulus, few small cumulus distant
WNW and NNE and ENE
Temperature: 84F; Dew Point 71F; Wind: estimated S at 3 kts,
Wind: Light
Sea-level pressure: 30.06 ins. Hg, about the same as 3 hours ago 
Visibility: 15 miles, hazy
BHO SA 1455 90 SCT 15 179/84/71/E1703/006/ FEW SML CU DSNT WNW AND 
NNE AND ENE HAZY WND LGT/ 8/130 55001
 
1 P.M.
Weather: Scattered cumulus, moderate cumulus in all directions
Temperature: 92F; Dew Point: 69F; Wind: estimated SSW at 6 kts,
Wind: Light
Sea-level pressure: 30.02 ins. Hg, steady, then falling
Visibility: 15 miles, hazy 
6-hr Max temp: 92F  
6-hr Min temp: 74F
BHO SA 1755 60 SCT 15 167/92/69/E2006/002/ MDT CU ALQDS HAZY 
WND LGT/ 8/200 58012 10092 20074


SUMMARY FOR MONDAY, AUGUST 17, 2015 
  
TEMPERATURE (DEGREES F)
MAX.....90   NORMAL.....79 
MIN.....70   NORMAL.....62 
MEAN....80   NORMAL.....71 
 
DEPARTURE FROM 30-YEAR NORMAL........................+9
TOTAL DEPARTURE FOR THE MONTH.......................+34  [+1.8 DEGREES/DAY]
 
COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL COOLING UNITS FOR YESTERDAY..............15   DEPARTURE..........+9
TOTAL COOLING UNITS FOR THE MONTH.............145   DEPARTURE.........+30
TOTAL COOLING UNITS FOR THE SEASON............539   DEPARTURE.........+73
TOTAL COOLING UNITS LAST SEASON TO DATE.......421   DIFFERENCE.......+118
 
PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY...................17 W  AT   4:43 P.M.        
                   ASOS........................18 W  AT   3:30 P.M.     
                   DAVIS.......................17 SW AT   7:55 P.M.* RMY 18
FASTEST MILE FOR YESTERDAY.....................12 W  AT   4:42 P.M.     
MAXIMUM 2-MINUTE ASOS AVERAGE..................15 W  AT   4:00 P.M.       
MAXIMUM 2-MINUTE DAVIS AVERAGE.................12 W  AT   4:00 P.M.     
AVERAGE WIND SPEED AND DIRECTION..............7.3 WNW 
                   ASOS.......................8.3
                   DAVIS......................6.7 W [268 deg.]
* 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...........2.13  DEPARTURE.....-0.23
                          ASOS..............2.16
TOTAL PRECIPITATION FOR THE YEAR...........29.49  DEPARTURE.....-3.86
                        ASOS...............N/A ***
*** ASOS annual total not available due to erroneous readings

PRELIMINARY CLIMATE SUMMARY FOR AUGUST 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

8/1  88/68/78/+6/0.06/729/84               28 WNW RMY N/A 
8/2  86/62/74/+2/0.00/865/100              24 SW  RMY N/A
8/3  89/68/79/+7/0.00/690/80               31 S   RMY N/A  
8/4  86/66/76/+4/0.31/422/49               45 W   RMY 50  TSTM  
8/5  84/64/74/+2/0.00/765/89               28 WNW RMY 27
8/6  80/59/70/-2/0.00/685/80               22 W   RMY 21
8/7  78/61/70/-2/0.00/845/99               20 ESE RMY 18
8/8  77/58/68/-4/0.00/741/87               18 E   RMY N/A
8/9  72/59/66/-6/T/458/54                  27 NNE RMY 26   
8/10 84/58/71/0/0.00/.../..                28 S   RMY N/A
8/11 70/63/67/-4/0.52/000/00               32 SSE RMY 35
8/12 83/65/74/+3/0.00/766/91               22 W   RMY 20
8/13 83/62/73/+2/0.00/832/99               18 WNW RMY 18
8/14 86/63/75/+4/0.00/837/100              21 S   RMY 23
8/15 91/66/79/+8/..../.../..               38 W   RMY 41  TSTM
8/16 87/65/76/+5/..../.../..               16 W   RMY N/A
8/17 90/70/80/+9/0.00/.../..               17 W   RMY 18

8/18 low since midnight is 70F; normal low is now 62F

DAILY RECORDS FOR AUGUST 2015
None so far.

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

RECORDS FOR AUGUST 18
HIGH 93F IN 2002
LOW 47F IN 1824
PRECIP 5.75 INCHES IN 1955 [DIANE]
PEAK GUST 46 MPH WNW IN 2007

RECORDS FOR AUGUST 19
HIGH 90F IN 1906, 1966, 2002
LOW 48F IN 1958
PRECIP 7.02 INCHES IN 1955 [DIANE - RECORD FOR MONTH]
PEAK GUST 78 MPH ENE IN 1991 - HURRICANE BOB 

TODAY'S REPORT PREPARED BY: Brian Fitzgerald