BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MAY 26, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME HIGH CLOUDS ON THE INCREASE TODAY MUCH COOLER TEMPERATURES WITH NORTHEAST WINDS High cirrus cloudiness was thickening by this afternoon well ahead of a warm front draped east to west across the Middle Atlantic states. A veering wind overnight from northwest to north- east has brought much cooler temperatures, which fell to 46F this morning. It rose to the upper 50's today despite the bright morning sunshine, which was becoming dimmed early this afternoon by the high clouds. Today's observations: 7 A.M. Weather: Clear, few cirrus Temperature: 50F, Dew point: 33F, Wind: ENE at 12G20 kts, Wind: Direction variable NNE to E Sea-level pressure: 30.32 inches Hg, rising Visibility: 55 miles, NW 70 miles 6-hour minimum temp: 46F 24-hour precipitation: 0.00 BHO SA 1155 CLR 55 268/50/33/0612G20/032/ FEW CI VSBY NW 70 WND 02V09/ 8/001 51019 10051 20046 10 A.M. Weather: High thin broken cirrus Temperature: 55F, Dew point: 30F, Wind: ENE at 9 kts, Wind: Direction variability NNE to E Sea-level pressure: 30.34 inches Hg, falling Visibility: 60 miles, NW 70 miles BHO SA 1455 250 –SCT 300 –BKN 60 274/55/30/0609/034/ VSBY NW 70 WND 02V09/ 8/001 50006 1 P.M. Weather: High dense scattered cirrus layer increasing, high overcast cirrus with thin spots in overcast to the northwest thru northeast thru southeast halo past hour Temperature: 57F, Dew point: 34F, Wind: E at 6 kts Sea-level pressure: 30.31 inches Hg, falling Visibility: 60 miles, northwest 70 miles 6-hour maximum temp: 58F BHO SA 1755 220 SCT E250 OVC 55 264/57/34/0906/031/ DENS CI LYR XCPT N-E THN SPTS IOVC NW-ESE HALO PST HR/ 8/006 58010 10058 20050 WEATHER SUMMARY FOR MONDAY, MAY 25, MEMORIAL DAY TEMPERATURE (DEGREES F) MAX.....76 NORMAL.....70 MIN.....51 NORMAL.....50 MEAN....64 NORMAL.....60 DEPARTURE FROM 30-YEAR NORMAL...........+4 TOTAL DEPARTURE FOR THE MONTH..........+77 [+2.9 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............1 DEPARTURE.......-5 TOTAL HEATING UNITS FOR THE MONTH...........165 DEPARTURE......-73 TOTAL HEATING UNITS FOR THE SEASON.........6061 DEPARTURE.....-203 TOTAL HEATING UNITS LAST SEASON TO DATE....5886 DIFFERENCE....+175 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............32 N AT 10:31 P.M. AEROVANE..............28 N AT 10:31 P.M. ASOS..................30 N AT 10:31 P.M. DAVIS.................30 N AT 10:30 P.M. FASTEST MILE FOR YESTERDAY...............18 N AT 10:32 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE............18 N AT 10:32 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........21 W AT 2:36 P.M. AVERAGE WIND SPEED AND DIRECTION.......10.1 WNW ASOS.................9.6 DAVIS...............10.5 WNW [300 DEG] 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..........3.45 DEPARTURE....+0.40 ASOS..............3.45 TOTAL PRECIPITATION FOR THE YEAR..........18.06 DEPARTURE....-2.94 ASOS.............19.13 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.....-0.1 TOTAL SNOWFALL FOR THE SEASON..............78.9 DEPARTURE.....18.8 PRELIMINARY CLIMATE SUMMARY FOR MAY 2009 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 5/1 64/53/59/+7/T/000/00 37 SSW AERO 37 MPH SSW 5/2 68/52/60/+8/0.05/263/31 32 WNW 5/3 64/48/56/+3/T/068/08 25 S 5/4 64/48/56/+3/0.01/009/01 17 SSW 5/5 52/44/48/-5/0.95/000/00 43 NNE AERO 40 MPH NNE 5/6 63/43/53/-1/0.40/189/22 24 SSE 5/7 68/49/59/+5/0.60/009/01 29 S 5/8 75/52/64/+10/0/690/80 28 S 5/9 71/55/63/+8/0.14/104/12 31 W TSTM 5/10 65/46/56/+1/0/840/97 53 W Aero 50 MPH W 5/11 63/41/52/-3/0/781/90 24 WNW 5/12 63/45/54/-2/0/696/80 22 ENE 5/13 70/45/58/+2/0/732/84 31 SSE AERO 29 MPH SSE 5/14 62/47/55/-2/0.10/166/19 53 S AERO 52 MPH S 5/15 76/54/65/+8/0/474/54 38 S AERO 38 MPH S 5/16 68/54/61/+4/T/457/52 35 S AERO 35 MPH S 5/17 61/49/55/-2/0.09/009/01 35 WNW AERO 33 MPH WNW 5/18 53/42/48/-10/0.04/168/19 27 NE 5/19 70/42/56/-2/0/813/92 28 S 5/20 82/49/66/+8/0/771/87 31 SSW 5/21 89/59/74/+15/0/870/98 37 S AERO 34 MPH S 5/22 87/59/73/+14/0/739/83 31 N 5/23 65/50/58/-1/T/428/48 28 NE 5/24 80/50/65/+5/1.07/536/60 25 WNW TSTM TRACE DIME SIZE HAIL 5/25 76/51/64/+4/0/.../.. 32 N 5/26 our morning low temp: 46F; the normal low is now 50F NEW DAILY RECORDS FOR MAY 2009... 5/14: RECORD PEAK WIND GUST 53 MPH S; surpasses previous record of 50 MPH SW in 1976 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 26 HIGH 89F IN 1914,1965 LOW 37F IN 1972 PRECIP 1.73 INS IN 2003 SNOWFALL TRACE IN 1967 (Fell as ice pellets in nor'easter) PEAK GUST 62 MPH NE IN 1967 RECORDS FOR MAY 27 HIGH 92F IN 1914 LOW 36F IN 1915 PRECIP 1.40 INS IN 1898 PEAK GUST 55 S IN 1956 TODAY'S REPORT PREPARED BY: Robert Skilling