BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, APRIL 21, 2009 ALL TIMES ARE IN EASTERN STANDARD TIME A HALF INCH OF RAINFALL OVERNIGHT EAST WINDS GUST OVER 40 MPH Rainfall amounted to only traces until on toward midnight last night. Then the rain fell at the rate of 0.1 to 0.2 inch per hour for several hours and a total of 0.52 inch was recorded by the time it ended around 4 a.m. EDT. East winds increased during the overnight period with gusts just over 40 MPH in the very early morning hours of today. The peak gust here was 43 MPH recorded several times before winds diminished rapidly after 4 a.m. EDT. Much heavier rain fell to our south over Rhode Island and southeastern Mass. with well over one inch in most of that area. Some totals included: 1.4 inches at Providence and New Bedford, 1.8 inches at Hyannis, and 2.34 inches in Falmouth. The greatest amount of rain fell at Nan- tucket with 2.52 inches. Today's weather observations: 7 A.M. Weather: Obscurement with dense fog, light drizzle Temperature: 48F, Dew point: 48F, Wind: E at 2 kts, Wind: Very light, speed estimated Sea-level pressure: 29.85 inches Hg, falling Visibility: 1/16 mile 6-hour minimum temperature: 42F 6-hourly rainfall: 0.24 in. 24-hourly rainfall: 0.52 in. BHO SA 1155 W2 X 1/16F 108/48/48/E1002/985/ LBXX PCPN VRY LGT/ 8//// 55015 ASOS 60023 MANUAL 6024/ ASOS 70051 MANUAL 70052 10048 20042 10 A.M. Weather: Obscurement with dense fog, light drizzle Temperature: 53F, Dew point: 53F, Wind: SSE at 9 kts Sea-level pressure: 29.85 inches Hg, rising Visibility: 1/16 mile 3-hourly rainfall: 0.01 inch BHO SA 1455 W2 X 1/16L-F 109/53/53/1609/985/ 8//// 53001 MANUAL 6001/ ASOS 60001 1 P.M. Weather: Partial obscurement with fog and light to briefly heavy rain showers occurring Temperature: 55F, Dew point: 55F, Wind: SSE at 15G23 kts, Wind: Direction variable ESE to S Sea-level pressure: 29.81 inches Hg, falling Visibility: 1/2 mile, variable 1/8 to 1 mile in stratus drifting over the summit 6-hourly max. temp: 55F 6-hourly rainfall: 0.08 inch BHO SA 1755 –X E4 OVC 1/2VRW-F 094/55/55/1515G23/981/ F5 STRA DRFTG OVR SMT VSBY 1/8V1 RW- BRFLY RW+ WND 12V18 RBUKN/ 8/7// 58015 ASOS 60009 MANUAL 6008/ 10055 20048 WEATHER SUMMARY FOR MONDAY, APRIL 20, 2009 TEMPERATURE (DEGREES F) MAX.....51 NORMAL......57 MIN.....36 NORMAL......39 MEAN....44 NORMAL......48 DEPARTURE FROM 30-YEAR NORMAL..................-4 TOTAL DEPARTURE FOR THE MONTH.................+11 [+0.4 DEGREE/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY.............21 DEPARTURE........+4 TOTAL HEATING UNITS FOR THE MONTH............399 DEPARTURE.......-11 TOTAL HEATING UNITS FOR THE SEASON..........5817 DEPARTURE.......-57 TOTAL HEATING UNITS LAST SEASON TO DATE.....5496 DIFFERENCE.....+321 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY............43 E AT 11:26 P.M. AEROVANE.............39 E AT 11:41 P.M. ASOS.................40 E AT 11:26 P.M. DAVIS................N/A FASTEST MILE FOR YESTERDAY..............32 E AT 11:38 P.M. * MAXIMUM 2-MINUTE ASOS AVERAGE...........28 E AT 11:27 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE..........N/A AVERAGE..............14.2 E ASOS.................14.1 DAVIS................12.8 E [080 deg] * last of several occurrences... PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M.....0.52 DEPARTURE.........+0.38 ASOS...............0.51 TOTAL PRECIPITATION FOR THE MONTH...........3.83 DEPARTURE.........+0.87 ASOS...............3.85 TOTAL PRECIPITATION FOR THE YEAR...........13.91 DEPARTURE.........-2.68 ASOS..............14.98 # # Includes erroneous ASOS precipitation data on 1/1/09, 1/2/09 and 2/27/09. 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.........-1.9 TOTAL SNOWFALL FOR THE SEASON..............78.9 DEPARTURE........+19.9 PRELIMINARY CLIMATE SUMMARY FOR APRIL 2009 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/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 4/1 43/31/38/-3/0.13/0/015/02 24 SE 4/2 52/39/46/+4/0.02/0/000/00 20 SSE 4/3 58/45/52/+10/0.70//000/00 39 SSE AERO 38 MPH SSE TSTM 4/4 51/38/45/+3/0.01/0/015/02 48 WSW AERO 48 MPH WSW 4/5 58/37/48/+5/0/0/551/71 40 W AERO 37 MPH W 4/6 55/38/47/+4/1.42/0/047/006 42 SE AER0 40 MPH SE TSTM 4/7 50/34/42/-1/T/0/109/14 36 WSW AERO 35 MPH WSW 4/8 45/32/39/-5/0/0/149/19 33 SW AERO 31 MPH SW 4/9 60/34/47/+3/0/0/692/88 36 SSW AERO 33 MPH SSW 4/10 65/41/53/+9/0.18/0/544/69 37 SSW AERO 35 MPH SSW 4/11 44/33/39/-6/0.77/0.2/000/00 35 N AERO 30 MPH N 4/12 43/29/36/-9/0/0/541/68 45 NW AERO 43 MPH WNW 4/13 52/29/41/-4/0/0/734/92 38 W AERO 35 MPH W 4/14 58/37/48/+2/0/0/696/87 25 E 4/15 49/36/43/-3/0/0/650/81 35 NE AERO 31 MPH NE 4/16 50/34/42/-4/0/0/806/100 29 NNE 4/17 69/35/52/+5/0/0/695/86 37 W AERO 33 MPH W 4/18 64/44/54/+7/0.05/0/170/21 28 W 4/19 52/38/45/-2/0.03/0/773/95 33 NNE AERO 28 MPH NNE 4/20 51/36/44/-4/0.07/0/.../... 43 E Aero 39 MPH E 4/21 morning low temp: 42F; our normal low is now 39F NEW DAILY RECORDS FOR APRIL 2009... None to date.. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR APRIL 21 HIGH 85 IN 1923 LOW 22 IN 1908 PRECIP 3.18 IN. IN 1991 SNOWFALL 0.8 IN. IN 1947 PEAK GUST 76e MPH NE IN 1940 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 TODAY'S REPORT PREPARED BY: Robert Skilling