BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY MONDAY, JULY 21, 2008 ALL TIMES ARE IN EASTERN STANDARD TIME UNLESS NOTED WINDSHIFT TO NORTHEAST DROPS TEMP 11 DEGREES EARLY AFTERNOON THUNDERSTORMS PASSING TO THE NORTH THROUGH EAST OF THE OBSERVATORY OVER THE WEEKEND LEAVE OVER ONE TO TWO INCHES IN PLACES WITHIN 10 MILES BUT ONLY 0.04 INCH RAIN HERE A sudden windshift to northeast dropped the temp. from a high of 84 degrees at 1:04 p.m. this afternoon to 73 by 2 p.m. Last Friday evening's thunderstorm left only 0.03 inch of rain here but 0.78 inch at Hingham, 10 miles to our east, while Sunday afternoon storms deposited a meager 0.01 here but one to two inches of rain from Boston to Quincy and Hingham. Late Sunday evening, still another thunderstorm, part of a dying squall line, finally brought 0.25 inch of rain here at the Observatory from about 12:30 to 2 a.m. EDT. Today's observations: 8 A.M. EDT Weather: Partial obscurement with fog, low overcast stratus, thin fog Temperature: 73F, Dew point: 72F, Wind: SSW at 9 kts Sea-level pressure: 29.83 inches Hg, rising Visibility: 2 miles 6-hourly minimum temperature: 70F 24-hourly rainfall: 0.25 inch BHO SA 1155 -X E4 OVC 2F 102/73/72/2109/983/ F2 HIER CLDS OCNL VSB SUN VSB/ 8/6// 51008 ASOS 60002 MANUAL 6002/ ASOS 70025 MANUAL 70025 10073 20070 11 A.M. EDT Weather: Broken cumulus, stratocumulus, few towering cumulus Temperature: 79F, Dew point: 70F, Wind: SW at 6 kts Sea-level pressure: 29.83 inches Hg, steady Visibility: 9 miles hazy BHO SA 1455 E18 BKN 45 BKN 9 102/79/70/2306/983/ TCU E-SE MDT CU ALQDS HAZY/ 8/800 50000 2 P.M. EDT Weather: Broken towering cumulus, altocumulus, thin fog and haze Temperature: 73F, Dew point: 69F, Wind: NE at 12 kts Sea-level pressure: 29.83 inches Hg, steady Visibility: 6 miles, 5 miles NE, 8 miles SW 6-hour max. temp. 84F BHO SA 1755 E35 BKN 100 BKN 6FH 102/73/69/0312/983/ TCU ALQDS FEW ACSL W-NW VSBY LWRG NE 5 THN FG SW 8 WSHFT/FROPA 10 GST 20 KTS PST HR/ 8/240 55000 10084 20073 WEATHER SUMMARY FOR SUNDAY, JULY 20 TEMPERATURE (DEGREES F) MAX.....88 NORMAL.....82 MIN.....71 NORMAL.....63 MEAN....80 NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL.............+8 TOTAL DEPARTURE FOR THE MONTH............+72 [+3.4 DEGREES/DAY] PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............27 NNW AT 2:33 P.M. * AEROVANE.............28 NNW AT 2:33 P.M. ASOS.................29 NNW AT 2:37 P.M. DAVIS................28 NNW AT 2:36 P.M. FASTEST MILE FOR YESTERDAY..............21 NNW AT 2:36 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE...........22 NNW AT 2:38 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........23 NNW AT 2:38 P.M. AVERAGE............10.0 S ASOS................9.4 DAVIS...............9.6 S [190 deg] * Last of several occurrences. Gust from NNW, thunderstorm passing to the north, trace of rain PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.25 DEPARTURE......+0.13 ASOS..............0.25 TOTAL PRECIPITATION FOR THE MONTH..........2.04 DEPARTURE......-0.38 ASOS..............2.07 TOTAL PRECIPITATION FOR THE YEAR..........27.04 DEPARTURE......-1.05 ASOS.............29.45 # # Includes erroneous ASOS precipitation data on 2/13/08. PRELIMINARY CLIMATE SUMMARY FOR JULY 2008 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 7/1 83/66/75/+5/0.15/411/45 28 SSW TSTM 7/2 84/61/73/+3/1.02/593/65 44 W TSTM Small hail 7/3 85/63/74/+4/T/793/87 45 SW Aero 44 MPH SW 7/4 69/59/64/-6/0.22/018/02 25 NE 7/5 70/62/66/-5/0.01/000/00 17 E 7/6 81/65/73/+2/0/245/27 20 S 7/7 86/67/77/+6/0/563/62 21 S 7/8 89/69/79/+8/0/753/83 30 SSE 7/9 88/70/79/+8/T/734/81 36 SSW TSTM Aero 35 MPH SSW 7/10 82/65/74/+3/T/887/98 28 W Aero 29 MPH W 7/11 83/61/72/0/0/759/84 17 NW 7/12 82/65/74/+2/0/631/70 28 S 7/13 81/66/74/+2/0/784/87 38 S Aero 40 MPH S 7/14 80/67/74/+2/0.36/468/52 23 W TSTM 7/15 87/67/77/+5/0/799/89 22 SSW 7/16 88/66/77/+5/0/.../.. 22 SSE 7/17 86/68/77/+5/0/.../.. 20 SW 7/18 91/66/79/+7/0.03/.../.. 23 SE TSTM 7/19 93/66/80/+8/T/.../.. 35 WSW Aero 35 WSW 7/20 88/71/80/+8/0.18/.../.. 27 NNW TSTM 7/21 morning low temp. 70F; normal low now 63F rainfall since midnight 0.07 inch NEW DAILY RECORDS FOR JULY None to date... DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JULY 21 HIGH 100F IN 1977 [RECORD FOR MONTH] LOW 48F IN 1890 PRECIP 2.09 INCHES IN 1938 PEAK GUST 60e MPH WNW IN 1977 RECORDS FOR JULY 22 HIGH 99F IN 1926 LOW 52F IN 1890 PRECIP 1.73 INCHES IN 1900 PEAK GUST 55 MPH IN 1983 TODAY'S REPORT PREPARED By: Robert Skilling