BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, MAY 11, 2015 ALL TIMES ARE IN EASTERN STANDARD TIME TEMPS HIT 88F ON SUNDAY, MONTHLY DEPARTURE NOW 6.8 DEGREES ABOVE NORMAL A maximum of 88F was recorded at approximately 3:00 PM EST, just 5 degrees shy of yesterday's daily record. Heat and humidity lingered into the evening hours, with 70F recorded by 11:00 PM EST. With a daily average yesterday of 74F, this adds a daily departure of +19, bringing the monthly departure 6.8 above normal. Another back door cold front moved in from the coast today, causing a wind shift from SW to NE just after the 10:00 AM EST observation. Temperatures tumbled as well, dropping from 84F at the mid morning observation to 65F just one hour later. By the 1:00 PM EST observation fog had begun, limiting visibility to 3/4 of a mile in all directions. Temperatures had fallen as low as 57F following the passage of the front. Today's Observations: 7 A.M. Weather: Clear, few altocumulus W-E Temperature: 72F; Dew Point: 65F; Wind: WSW at 9 kts Sea-level pressure: 30.12 ins. Hg, rising, then more slowly Visibility: 15 miles, thin fog in all directions, hazy 6-hr Max temp: 72F 6-hr Min temp: 65F 24-hr precip: none BHO SA 1155 CLR 15 201/72/65/2409/012/ FEW AC W-E THN FG ALQDS HAZY/ 8/030 51008 10072 20065 10 A.M. Weather: Scattered cumulus, few stratus fractus distant NE-ENE Temperature: 83F; Dew Point: 62F; Wind: SW at 7 kts, Sea-level pressure: 30.18 ins. Hg, falling, rising but still lower Visibility: 15 miles, except 10 mile NNW-ESE, thin fog, hazy BHO SA 1455 40 SCT 15 199/83/62/2307/018/ VSBY NNW-ESE 10 MI FEW STFRA DSNT NE-ENE THN FG ALQDS HAZY/ 8/100 55002 1 P.M. Weather: Fog Temperature: 58F; Dew Point: 53F; Wind: NE at 15G24 kts, Sea-level pressure: 30.11 ins. Hg, falling, then more quickly Visibility: 3/4 of a mile, fog 6-Hr Max temp: 84F 6-Hr Min temp: 57F BHO SA 1755 E2 OVC 3/4F 197/58/53/0515G24/011/ PK WND 0526/19/ 8//// 58002 10084 20057 SUMMARY FOR SUNDAY, MAY 10, 2015 TEMPERATURE (DEGREES F) MAX.....88 NORMAL.....65 MIN.....60 NORMAL.....46 MEAN....74 NORMAL.....55 DEPARTURE FROM 30-YEAR NORMAL......................+19 TOTAL DEPARTURE FOR THE MONTH......................+70 [+6.8 DEGREES/DAY] HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............0 DEPARTURE..........-10 TOTAL HEATING UNITS FOR THE MONTH..............53 DEPARTURE..........-60 TOTAL HEATING UNITS FOR THE SEASON...........6324 DEPARTURE.........+176 TOTAL HEATING UNITS LAST SEASON TO DATE......6255 DIFFERENCE.........+69 COOLING DEGREE DAYS (SEASON JAN TO DEC) TOTAL COOLING UNITS FOR YESTERDAY..............9 DEPARTURE..........+9 TOTAL COOLING UNITS FOR THE MONTH.............14 DEPARTURE.........+11 TOTAL COOLING UNITS FOR THE SEASON............14 DEPARTURE..........+9 TOTAL COOLING UNITS LAST SEASON TO DATE........3 DIFFERENCE........+11 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..................28 SSW AT 8:10 P.M.* ASOS.......................30 SSW AT 8:11 P.M. DAVIS......................29 SW AT 5:01 P.M. RMY 30 FASTEST MILE FOR YESTERDAY....................22 SSW AT 5:04 P.M.* MAXIMUM 2-MINUTE ASOS AVERAGE.................23 SSW AT 5:03 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE................23 SSW AT 5:02 P.M. AVERAGE WIND SPEED AND DIRECTION.............14.3 SW ASOS......................13.8 DAVIS.....................12.9 SW [223 degrees] * Last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.00 DEPARTURE.....-0.12 ASOS...............0.00 TOTAL PRECIPITATION FOR THE MONTH...........0.03 DEPARTURE.....-1.19 ASOS...............0.03 TOTAL PRECIPITATION FOR THE YEAR...........17.95 DEPARTURE.....-1.69 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 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 77/56/67/+13/0.03/0.0/.../.. 29 SW RMY N/A 5/6 74/54/64/+10/0.00/0.0/.../.. 24 SSW RMY 25 5/7 84/52/68/+13/0.00/0.0/.../.. 29 S RMY 32 5/8 74/44/59/+4/0.00/0.0/.../.. 27 NNE RMY 26 5/9 77/44/61/+6/0.00/0.0/.../.. 30 S RMY 32 5/10 88/60/74/+19/0.0/0.0/.../.. 28 SSW RMY 30 5/11 low since midnight is 65F; normal low now 46F 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 11 HIGH 90F IN 1993 LOW 28F IN 1900 PRE 1.28 INS IN 1957 SNOW 1.0 INS IN 1907 (LATEST MEASURABLE SNOW ON RECORD) PEAK GUST 75e MPH NW IN 1945 RECORDS FOR MAY 12 HIGH 88F IN 2001 LOW 29F IN 1907 PRECIP 1.49 INCHES IN 1968 PEAK GUST 76 MPH S IN 1974 TODAY'S REPORT PREPARED BY: Brian Fitzgerald