BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY WEDNESDAY, APRIL 25, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME CLOUDY SKIES AND MUCH COOLER TEMPERATURES TODAY The sky clouded over early this morning and continues heavily overcast around noon with the temperature only in the mid-50's to upper 50's as compared to the 70's yesterday. Today's observations: 7 A.M. Weather: High thin overcast Temperature: 52F, Dew point: 29F, Wind: estimated from NNE @ 02 kts Sea-level pressure: 30.10 ins. Hg, rising Visibility: 55 miles, light haze, visibility NE 25 6-hour min. 47 deg. BHO SA 1155 300 –OVC 55 194/52/29/E0302/010/ AC DSNT WSW-NNW/ FEW LWR CI THN K ALG HRZN NNE VSBY NE-E 20 HAZY/ 8/037 52011 10053 20047 10 A.M. Weather: Overcast altocumulus Temperature: 55F, Dew point: 28F, Wind: Calm Sea-level pressure: 30.09 inches Hg, falling Visibility: 60 miles BHO SA 1455 E95 OVC 60 191/55/28/0000/009/ 8/07/ 58003 1 P.M. Weather: Overcast Temperature: 58F, Dew point: 29F, Wind: W @ 05 KTS [light and variable] Sea-level pressure: 29. inches Hg, falling Visibility: 50 miles, 30 miles W-NW PCPN PRSNT 6-hourly max. temp. 58 deg. 0 BHO SA 1755 SCT 100 E150 OVC 50 175/58/29/2605/005/ VIRGA BRGHT SPTS IOVC VSBY W-NW 30 PCPN PRSNT WND L/V 8/07/ 56016 10058 20051 WEATHER SUMMARY FOR TUESDAY, APRIL 24 TEMPERATURE (DEGREES F) MAX.....73 NORMAL.....59 MIN.....50 NORMAL.....40 MEAN....62 NORMAL.....49 DEPARTURE FROM 30-YEAR NORMAL..........+13 TOTAL DEPARTURE FOR THE MONTH.........- 60 (-2.7 DEGREES/DAY) HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.......... 3 DEPARTURE........-13 TOTAL HEATING UNITS FOR THE MONTH.........536 DEPARTURE.......+ 61 TOTAL HEATING UNITS FOR THE SEASON.......5530 DEPARTURE.......-409 TOTAL HEATING UNITS LAST SEASON TO DATE..5324 DIFFERENCE......+206 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............39 W AT 8:08 A.M. AEROVANE.............41 WNW AT 8.00 A.M. ASOS.................38 WNW AT 8:02 A.M. DAVIS................40 W AT 8:06 A.M. FASTEST MILE FOR YESTERDAY..............30 W AT 8:10 A.M. * MAXIMUM 2-MINUTE ASOS AVERAGE...........30 W AT 8:10 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........30 W AT 8:10 A.M. AVERAGE WIND SPEED AND DIRECTION........14.0 WNW ASOS................13.2 DAVIS...............N/A * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE.....-0.14 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........7.18 DEPARTURE.....+3.66 ASOS..............6.85 TOTAL PRECIPITATION FOR THE YEAR..........18.92 DEPARTURE.....+1.77 ASOS.............18.49 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE......-0.1 TOTAL SNOWFALL FOR THE MONTH................0.2 DEPARTURE......-2.3 TOTAL SNOWFALL FOR THE SEASON..............27.6 DEPARTURE.....-31.8 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2007......CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available 4/1 59/33/46/+5/0.42/0/511/67 30 S 4/2 39/35/37/-5/0.33/0/000/00 27 E 4/3 41/32/37/-5/0.04/0/000/00 28 ENE 4/4 36/32/34/-8/0.90/0.2/000/00 38 E 4/5 43/26/35/-8/0.21/T/163/21 36 WSW 4/6 39/23/31/-12/0/0/590/76 36 WSW 4/7 40/26/33/-10/0/0/405/52 35 W 4/8 40/25/33/-11/0/0/619/79 44 W Aero 42 MPH W 4/9 50/30/40/-4/0/0/746/95 36 W 4/10 43/30/37/-7/0/0/158/20 28 W 4/11 51/28/40/-5/0/0/712/90 22 SSE 4/12 39/32/36/-9/0.89/T/000/00 42 E Aero 40 MPH E 4/13 47/31/39/-6/0/0/096/12 41 W Aero 42 MPH W 4/14 52/35/44/-2/0/0/392/49 37 W 4/15 44/35/40/-6/1.75/T/000/00 66 E Aero 64 MPH E 4/16 50/40/45/-1/1.56/0/000/00 73 E Aero 73 MPH E 4/17 40/35/38/-9/0.69/T/000/00 54 NNE Aero 53 MPH NNE 4/18 39/36/38/-9/0.37/0/000/00 43 N 4/19 49/36/43/-4/0.02/T/285/35 38 NE Aero 35 MPH NE 4/20 57/36/47/-1/0/0/815/100 31 N 4/21 74/45/60/+12/0/0/753/92 24 NW 4/22 75/50/63/+14/0/0/779/95 31 SSE 4/23 85/49/67/+18/0/0/675/82 42 S Davis 45 MPH S 4/24 73/50/62/+13/0/0/586/71 39 W Aero 41 MPH W 4/25 morning low temp. 47 deg; normal low now 40 deg. NEW DAILY RECORDS FOR APRIL SO FAR.... 4/15 - NEW RECORD HIGH PEAK WIND GUST FOR THIS DATE OF 66 MPH E; the previous record was 59 mph estimated from the S in 1946 and measured from the S in 1980. NEW RECORD DAILY RAINFALL OF 1.75 INS.; previous record 1.29 ins. in 1990. 4/16 - NEW RECORD HIGH PEAK WIND GUST OF 73 MPH E; the previous record for this date was 63 mph SSE in 1996. 4/23 - EQUALED RECORD HIGH MAXIMUM TEMPERATURE OF 85 DEGREES set in 1908. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 25 HIGH 80 IN 1942 LOW 24 IN 1892 PRECIP 1.38 IN. IN 1901 SNOWFALL 0.7 IN. IN 2002. PEAK GUST 66 MPH SE IN 1968 RECORDS FOR APRIL 26 HIGH 83 IN 1908 LOW 23 IN 1919 PRECIP 1.64 IN. IN 1931 SNOWFALL 1.0 IN. IN 2000 PEAK GUST 53 MPH SSW IN 1996 TODAY'S REPORT By: Robert Skilling