BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY THURSDAY, APRIL 22, 2010 ALL TIMES ARE IN EASTERN STANDARD TIME THUNDERSTORMS PASS THROUGH THE AREA Towering cumulus clouds began building up late this morning and several rumbles of thunder were heard this afternoon between 2:00 and 4:00 PM (EDT), and lightning was observed to the east. Only a trace of precipitation was measured at 2:00 PM EDT. Today's observations: 7 A.M. Weather: Clear skies, thin fog, few cumulus south-southwest thru west-northwest and overhead, few altocumulus southwest thru northeast Temperature: 51F, Dew point: 48F, Wind: SSW at 9 kts Sea-level pressure: 29.74 inches Hg, rising Visibility: 8 miles, increasing, thin fog dissipating 6-hour minimum temp: 46F BHO SA 1155 –X CLR 8 072/51/48/2109/974/ F2 FEW CU SSW-WNW AND OVHD FEW AC SW-NE THN FG VSBY INCR FG DSPTNG/ 8/130 52010 10051 20046 10 A.M. Weather: Clear, few cumulus west-southwest thru northwest, few altocumulus west-southwest thru north-northwest, hazy Temperature: 63F, Dew point: 46F, Wind: SW at 8 kts, Wind: Direction variable SSW to W Sea-level pressure: 29.72 inches Hg, falling Visibility: 15 miles, haze BHO SA 1455 CLR 15 063/63/46/2208/972/ FEW CU WSW-NW FEW AC WSW-NNW HAZY WND 20V27/ 8/130 58009 1 P.M. Weather: Broken stratocumulus, broken altocumulus, few lower cumulus fractus, towering cumulus all quadrants except northeast thru east, cumulonimbus west moving east, sun disc visible, virga northeast, light rain Temperature: 67F, Dew point: 45F, Wind: WSW at 7 kts, Wind: Direction variable Sea-level pressure: 29.65 inches Hg, falling Visibility: 40 miles, light rain 6-hourly max. temp: 70F BHO SA 1755 E70 BKN 150 BKN 40R- 042/67/45/2407/965/ FEW LWR CUFRA TCU ALQDS XCPT NE-E CB W MOVG E SUN DSC VSBL VIRGA NE WND VRB RB48 PCPN VRY LGT/ 8/360 56021 MANUAL 6000/ 10070 20051 WEATHER SUMMARY FOR WEDNESDAY, APRIL 21 TEMPERATURE (DEGREES F) MAX.....71 NORMAL.....58 MIN.....49 NORMAL.....39 MEAN....60 NORMAL.....48 DEPARTURE FROM 30-YEAR AVERAGE...............+12 TOTAL DEPARTURE FOR THE MONTH...............+173 [+8.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............5 DEPARTURE.......-12 TOTAL HEATING UNITS FOR THE MONTH...........257 DEPARTURE......-170 TOTAL HEATING UNITS FOR THE SEASON.........5353 DEPARTURE......-538 TOTAL HEATING UNITS LAST SEASON TO DATE....5832 DIFFERENCE.....-479 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY.............30 S AT 5:08 P.M. AEROVANE..............31 SSE AT 4:22 P.M. ASOS..................30 SSW AT 5:09 P.M. DAVIS................ 30 S AT 7:04 P.M. THE FASTEST MILE FOR YESTERDAY...........23 S AT 6:01 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE............23 SSW AT 5:09 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE...........22 S AT 5:09 P.M. AVERAGE WIND SPEED AND DIRECTION.........11.2 S ASOS..................10.5 DAVIS.................10.0 SSW [203 DEG] * 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..........1.83 DEPARTURE......-1.27 ASOS..............1.77 TOTAL PRECIPITATION FOR THE YEAR..........29.74 DEPARTURE.....+13.01 ASOS.............29.87 SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M..........0.0 DEPARTURE......-0.1 TOTAL SNOWFALL FOR THE MONTH..............Trace DEPARTURE......-2.2 TOTAL SNOWFALL FOR THE SEASON..............64.4 DEPARTURE......+5.3 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2010 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 59/43/51/+10/T/0/359/47 24 NNW AERO 30 MPH NNW 4/2 67/46/57/+15/0.00/0/728/95 21 SSE 4/3 75/45/60/+18/0.00/0/731/95 26 SSE 4/4 76/45/61/+19/0.00/0/617/80 27 W AERO 29 MPH W 4/5 72/53/63/+20/0.00/0/635/82 37 SSE AERO 40 MPH SSE 4/6 68/50/59/+16/T/0/202/26 23 W 4/7 90/45/68/+25/0.00/0/578/74 36 WSW AERO 41 MPH WSW 4/8 65/45/55/+11/0.00/0/611/78 31 ENE 4/9 56/37/47/+3/1.12/0/000/00 35 W AERO 39 MPH W 4/10 56/37/47/+3/0.00/0/663/84 45 W AERO 52 MPH W 4/11 69/47/58/+13/0.00/0/506/64 36 W AERO 40 MPH W 4/12 61/43/52/+7/0.00/0/635/80 31 W AERO 33 MPH W 4/13 56/39/48/+3/0.00/0/613/77 23 S 4/14 65/37/51/+5/0.00/0/760/95 28 WNW AERO 32 MPH WNW 4/15 60/40/50/+4/0.00/0/739/92 30 NE 4/16 43/34/39/-7/.../T/000/00 26 E 4/17 41/36/39/-8/.../T/000/00 27 ENE 4/18 49/37/43/-4/0.07/0/.../.. 29 WNW 4/19 58/35/47/0/0.00/0/.../.. 30 WNW AERO 32 MPH WNW 4/20 68/43/56/+8/T/0/.../.. 26 WNW AERO 28 MPH WNW 4/21 71/49/60/+11/0.00/0/.../.. 30 S AERO 31 MPH SSE 4/22 the morning low temp: 46F; the normal low is 39F NEW DAILY RECORDS FOR APRIL 2010 4/4 - new record high maximum temperature of 76F; surpasses 71F in 1950. 4/5 - new record high minimum temperature of 53F; surpasses 52F in 1981 4/7 - new record high maximum temperature of 90F; surpasses 86F in 1929 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 22 HIGH 85 IN 1977, 2001 LOW 26 IN 1981 PRECIP 1.85 IN. IN 2000 SNOWFALL 3.0 IN. IN 1940 PEAK GUST 68e MPH NW IN 1945 RECORDS FOR APRIL 23 HIGH 85 IN 1908, 2007 LOW 25 IN 1933,1989 PRECIP 1.51 IN. IN 1998 SNOWFALL 0.5 IN. IN 1911, 1956 PEAK GUST 64 MPH WNW IN 1962 TODAY'S REPORT PREPARED BY: Sean Fankhauser/Stephanie Radner