BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY SATURDAY, APRIL 30, 2011 ALL TIMES ARE IN EASTERN STANDARD TIME MOSTLY CLOUDY AND COOLER TODAY... There was little sunshine early this morning before low clouds moved in and filled the sky by mid-morning. Stratocumulus have dominated the sky since then, with just a few breaks appearing in the clouds. The wind direction shifted from WNW to N shortly after 1 PM EDT, which has kept the temperature in the middle 50s after reaching 59 earlier this morning. The month of April will finish about two degrees warmer than average. Today's observations: 7 A.M. Weather: Overcast altocumulus, breaks in overcast overhead and distant WSW-N, few stratocumulus distant W-NNW, few cumulus fractus distant W-NW, sun occasionally dimly visible, light haze Temperature: 51F, Dew point: 37F; Wind: NW at 11G20 kts, Sea-level pressure: 29.97 ins. Hg, rising Visibility: 50 miles, light haze 6-hour min. temp: 50F BHO SA 1155 E90 OVC 50 149/51/37/3111G20/997/ BINOVC OVHD AND DSNT WSW-N FEW SC DSNT W-NNW FEW CUFRA DSNT W-NW SUN OCNLY DMLY VSBL LGT HZ/ 8/57/ 51024 10054 20050 10 A.M. Weather: Scattered stratocumulus, broken stratocumulus, broken altocumulus, few cumulus fractus all quadrants Temperature: 56F, Dew point: 38F; Wind: WNW at 8 kts, Wind: Light and variable Sea-level pressure: 30.01 inches Hg, rising Visibility: 75 miles BHO SA 1455 40 SCT E50 BKN 90 BKN 75 163/56/38/3008/001/ FEW CUFRA ALQDS WND LGT AND VRB/ 8/570 51014 1 P.M. Weather: Broken stratocumulus, overcast altocumulus, breaks in overcast distant ENE-ESE, few lower cumulus Temperature: 54F, Dew point: 39F; Wind: N at 5 kts, Wind: Light Sea-level pressure: 30.04 inches Hg, rising Visibility: 75 miles BHO SA 1755 E55 BKN 75 BKN 100 OVC 75 174/54/39/0105/004/ BINOVC DSNT ENE-ESE FEW LWR CU WND LGT/ 8/57/ 53011 10059 20051 WEATHER SUMMARY FOR FRIDAY, APRIL 29 TEMPERATURE (DEGREES F) MAX.....74 NORMAL.....61 MIN.....53 NORMAL.....41 MEAN....64 NORMAL.....51 DEPARTURE FROM 30-YEAR NORMAL..................+13 TOTAL DEPARTURE FOR THE MONTH..................+64 [+2.0 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............1 DEPARTURE.......-13 TOTAL HEATING UNITS FOR THE MONTH...........487 DEPARTURE.......-61 TOTAL HEATING UNITS FOR THE SEASON.........5885 DEPARTURE......-127 TOTAL HEATING UNITS LAST SEASON TO DATE....5475 DIFFERENCE.....+410 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............37 S AT 2:31 P.M. AEROVANE...............37 S AT 2:31 P.M. ASOS...................36 S AT 2:32 P.M. DAVIS..................34 SSW AT 1:06 P.M. THE FASTEST MILE FOR YESTERDAY............26 S AT 2:38 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE.............26 SSW AT 2:17 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE............28 S AT 2:17 P.M. AVERAGE WIND SPEED AND DIRECTION........11.9 WNW ASOS.................11.2 DAVIS................11.5 SW [236 DEG] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE........-0.13 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH..........4.61 DEPARTURE........+0.42 ASOS............4.57 TOTAL PRECIPITATION FOR THE YEAR..........18.22 DEPARTURE........+0.40 ASOS..............18.96** **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........-1.4 TOTAL SNOWFALL FOR THE SEASON..............96.8 DEPARTURE.......+36.9 PRELIMINARY CLIMATE SUMMARY FOR 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/-7/0.71/1.6/000/00 35 N AERO 40 MPH N 4/2 50/33/42/0/T/0.0/581/76 38 W AERO 41 MPH W 4/3 53/35/44/+2/0.00/0.0/753/98 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/+5/0.16/0.0/023/03 52 S AERO 55 MPH S 4/6 51/31/41/-2/0.00/0.0/490/63 43 WSW AERO 43 MPH WSW 4/7 52/32/42/-1/0.00/0.0/749/96 22 SSE 4/8 52/34/43/-1/0.00/0.0/422/54 25 SSE 4/9 60/33/47/+3/0.00/0.0/699/89 30 SE 4/10 63/37/50/+6/0.03/0.0/496/63 31 SSE 4/11 69/47/58/+13/0.02/0.0/308/39 35 S AERO 36 MPH S 4/12 61/43/52/+7/0.15/0.0/024/03 43 WNW AERO 45 MPH WNW 4/13 47/40/44/-1/1.13/0.0/000/00 39 ENE AERO 39 MPH ENE 4/14 63/39/51/+5/T/0.0/607/76 29 NNW 4/15 47/31/39/-7/0.00/0.0/730/91 28 NW 4/16 46/31/39/-7/0.18/0.0/266/33 45 ESE AERO 46 MPH ESE 4/17 61/46/54/+7/1.12/0.0/347/43 63 ESE AERO 63 MPH ESE 4/18 59/40/50/+3/T/0.0/486/60 39 SW AERO 38 MPH WSW 4/19 49/38/44/-3/0.09/0.0/000/00 20 NW 4/20 44/38/41/-7/T/0.0/000/00 31 NE AERO 32 MPH NE 4/21 54/35/45/-3/0.00/0.0/703/86 60 W AERO 62 MPH W 4/22 52/33/43/-6/0.00/0.0/517/63 21 WNW 4/23 52/36/44/-5/0.43/0.0/000/00 42 SSE AERO 42 MPH SSE 4/24 74/51/63/+14/0.04/0.0/297/36 39 WSW AERO 41 MPH W 4/25 56/45/51/+1/.../0.0/.../.. 17 NE 4/26 64/45/55/+5/T/0.0/.../.. 24 NNE 4/27 78/58/68/+18/0.01/0.0/000/00 36 S AERO 39 MPH S 4/28 65/60/63/+12/.../0.0/.../.. 54 S AERO 54 MPH S 4/29 74/53/64/+13/0.00/0.0/.../.. 37 S AERO 37 MPH S 4/30 morning low temp. is 50F; the normal low temp. is now 42F DAILY RECORDS FOR APRIL 2011 4/17 - NEW RECORD PEAK GUST OF 63 MPH ESE; surpasses the previous record of 58 MPH NW in 1994 4/27 - NEW RECORD HIGH MINIMUM TEMPERATURE OF 58F; surpasses the previous record of 57F in 1900,1979 4/28 - NEW RECORD HIGH MINIMUM TEMPERATURE OF 60F; surpasses the previous record of 57F in 1935,2009 DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 30 HIGH 86 IN 1942 LOW 30 IN 1931 PRECIP 1.41 IN 1991 SNOWFALL 0.3 IN. IN 1909 PEAK GUST 64e MPH NW IN 1978 RECORDS FOR MAY 1 HIGH 87F IN 1899 LOW 29F IN 1978 PRECIP 2.53 INCHES IN 1921 SNOWFALL TRACE IN 1905,1917,1921,1995. PEAK GUST 57 MPH NW IN 1974 TODAY'S REPORT PREPARED BY: Mike Iacono