BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, APRIL 7, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME CLOUDS REMAIN TO OUR SOUTH SO A BEAUTIFUL SUNNY BUT A BIT COOL EARLY APRIL DAY TODAY Middle and high clouds could be seen to our south this morning and a few cumulus were developing. but we've had full sunshine since 6:45 AM EDT. Overnight low temps. dropped through the 30's to just about 32F for a low this morning with mid- 20's below the summit with a temperature inversion evident very early today. A very light sea breeze was trying to develop by early afternoon after light NNW to N winds this morning. Today's observations: 7 A.M. Weather: Scattered cirrus radiatus, layer extending ESE-WSW, few cirrus and cirrocumulus E-SE, few cirrus WSW, altocumulus layer extending ESE-WSW, few patches of dense shallow ground fog dissipating distant WSW and WNW below inversion past hour Temperature: 36F, Dew point: 26F; Wind: NNW at 4 kts Sea-level pressure: 30.12 ins. Hg, rising Visibility: 70 miles, light distant haze 6-hour min. temp: 32F BHO SA 1155 220 SCT 250 SCT 70 199/36/26/3304/012/ AC LYR XTDNG ESE-WSW CI LYR XTDNG ESE-WSW CI/CC E-ESE FEW CI WSW FEW PTCHS DNS SHLW GF BLO INVSN DSSPTG PST HR LGT DSNT HZ/ 8/071 52013 10036 20032 10 A.M. Weather: Clear, cumulus fractus, cumulus forming overhead, thru east thru south, altocumulus layer distant S-SSW, cirrus/cirrostratus layer southeast thru west-southwest Temperature: 43F, Dew point: 24F; Wind: W at 20G30 kts, Wind: Light Sea-level pressure: 30.13 inches Hg, falling Visibility: 65 miles, 70 miles northwest, light distant haze BHO SA 1455 CLR 65 204/43/24/3005/013/ CUFRA/CU FRMG OVHD-E-S AC LYR DSNT S-SSW CI/CS LYR DSNT SE-WSW VSBY NW 70 LGT DSNT HZ/ 8/178 50005 1 P.M. Weather: Clear, cumulus fractus, cumulus forming overhead-ESE-S-W, cirrus or cirrostratus layer visible distant S-SW Temperature: 45F, Dew point: 26F; Wind: NNE at 6 kts, Wind: Light Sea-level pressure: 30.10 inches Hg, falling Visibility: 65 miles, 70 to northwest, light distant haze 6-hour max. temp. 47F BHO SA 1755 CLR 65 192/45/26/0306/010/ CUFRA/CU FRMG OVHD-ESE-S-W CI/CS LYR DSNT S-SW VSBY NW 70 LGT DSNT HZ/ 8/108 56012 10047 20036 WEATHER SUMMARY FOR WEDNESDAY, APRIL 6 TEMPERATURE (DEGREES F) MAX.....51 NORMAL.....52 MIN.....31 NORMAL.....34 MEAN....41 NORMAL.....43 DEPARTURE FROM 30-YEAR NORMAL...................-2 TOTAL DEPARTURE FOR THE MONTH...................-2 [-0.5 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............24 DEPARTURE........+2 TOTAL HEATING UNITS FOR THE MONTH...........139 DEPARTURE........+2 TOTAL HEATING UNITS FOR THE SEASON.........5537 DEPARTURE.......-64 TOTAL HEATING UNITS LAST SEASON TO DATE....5135 DIFFERENCE.....+402 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............43 WSW AT 12:02 P.M. AEROVANE...............43 WSW AT 12:02 P.M. ASOS...................41 WSW AT 12:02 P.M. DAVIS..................44 W AT 11:32 A.M. THE FASTEST MILE FOR YESTERDAY............31 W AT 12:09 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............30 W AT 12:09 A.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............31 W AT 12-1 A.M. AVERAGE WIND SPEED AND DIRECTION........18.4 W ASOS.................17.7 DAVIS................18.0 W [260 DEG] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M... 0.00 DEPARTURE........-0.15 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........1.30 DEPARTURE........+0.40 ASOS............1.28 TOTAL PRECIPITATION FOR THE YEAR..........14.91 DEPARTURE........+0.38 ASOS..............15.67** ** ASOS data is in error due to system failure on 1/12-13 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE........-0.1 TOTAL SNOWFALL FOR THE MONTH................1.6 DEPARTURE........+0.9 TOTAL SNOWFALL FOR THE SEASON..............96.8 DEPARTURE.......+39.2 PRELIMINARY CLIMATE SUMMARY FOR MARCH/APRIL 2011 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust when significant TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 4/1 36/31/34/-7/0.71/1.6/.../.. 35 N AERO 40 MPH N 4/2 50/33/42/0/T/0.0/.../... 38 W AERO 41 MPH W 4/3 53/35/44/+2/0.00/0.0/.../.. 41 W AERO 42 MPH W 4/4 46/38/42/0/0.43/T/000/00 33 SE AERO 36 MPH SE 4/5 61/35/48/+5/0.16/0.0/.../.. 52 S AERO 55 MPH S 4/6 51/31/41/-2/0.00/0.0/.../.. 43 WSW AERO 43 MPH WSW 4/7 our morning low temp: 32F; the normal low is now 34F DAILY RECORDS FOR APRIL 2011 None so far DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 7 HIGH 86 IN 1929 LOW 13 IN 1982 PRECIP 1.72 IN. IN 1924 SNOWFALL 4.5 IN. IN 1967, 1996 PEAK GUST 65 MPH WNW IN 1982 RECORDS FOR APRIL 8 HIGH 87 IN 1991 LOW 17 IN 1888 PRECIP 1.78 IN. IN 1956 SNOWFALL 9.3 IN. IN 1956 PEAK GUST 70 MPH S IN 2000 TODAY'S REPORT PREPARED BY: Robert Skilling