BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MAY 7, 2013 ALL TIMES ARE IN EASTERN STANDARD TIME WARM, DRY, AND QUIET WITH PLENTY OF SUNSHINE; The recent streak of cool temperatures has come to an end! Temperatures today are averaging close to 10 degrees above normal. The high temperature on the summit reached 77F just after 2 PM EDT. That's the warmest temperature recorded on the summit so far this season, and the warmest since October 6 (77F). We've finally broken away from the cool, raw N-E flow. A southerly wind developed late yesterday, and continues for the most part today. Consequently, a much warmer and more moist air mass has invaded the region. The dew point temperature has risen from the mid 40s this morning to the mid 50s this afternoon. You can feel just a touch of humidity in the warm spring air. Very dry conditions continue. From March 20 through May 7 (49 days), Blue Hill has received only 2.44 inches of precipitation. That is only 32% of the 30-year normal of 7.67 inches for this time period. No measurable precipitation has fallen since April 25. Today's observations: 7 A.M. Weather: Scattered stratocumulus (2 levels) scattered thin cirrus, stratocumulus distant ENE-SSW, few cirrus distant S-W, inversion present, thin smoke layer aloft distant W-NNE, dark smoke layer along horizon below inversion NW-NE, distant haze Temperature: 59F; Dew Point: 44F; Wind: Estimated SW at 3 kts, Wind: Light Sea-level pressure: 30.19 ins. Hg, rising slightly then steady Visibility: 60 miles, NW 70 miles, NNW-E-S lower, distant haze 6-hour min. temp: 50F BHO SA 1155 40 SCT 60 SCT 250 –SCT 60 225/59/44/E2203/019/ SC DSNT ENE-SSW FEW CI DSNT S-W INVSN PRSNT THN K LYR ALF DSNT W-NNE DRK K LYR ALG HRZN BLO INVSN NW-NE DSNT HZ VSBY NW 70 NNW-E-S LWR WND LGT/ 8/501 51003 10059 20050 10 A.M. Weather: Scattered stratocumulus, scattered cumulus, scattered thin cirrus, lower stratocumulus distant E-SSW, small cumulus forming NE-S-WSW and in the vicinity of the station, cirrus distant SSE-WNW invading the sky, thin smoke layer distant W-NE, light distant haze Temperature: 71F; Dew Point: 51F; Wind: SE at 7 kts, Wind: Direction variable ESE-S Sea-level pressure: 30.19 ins. Hg, steady then falling slightly Visibility: 65 miles, light distant haze SW-N estimated top 15 hundred feet over city N, hazy all quadrants BHO SA 1455 40 SCT 60 SCT 250 –SCT 65 224/71/51/1407/019/ LWR SC DSNT E-SSW SML CU FRMG NE-S-WSW AND VCTY STN CI DSNT SSE-WNW INVADING THN K LYR DSNT W-NE LGT DSNT HZ WND 11V17/ 8/504 58001 1 P.M. Weather: Scattered cumulus, scattered stratocumulus cumulogenitus, scattered thin cirrus, moderate cumulus all quadrants, cirrus invading the sky, low stratus/fog over ocean distant ENE-E, mostly clear sky distant N-NE, light distant haze Temperature: 76F; Dew Point: 55F; Wind: S at 7 kts, Wind: Direction variable ESE-SSW Sea-level pressure: 30.16 ins. Hg, falling Visibility: 65 miles, light distant haze 6-hour max. temp: 76F BHO SA 1755 E45 SCT 55 SCT 250 –SCT 65 213/76/55/1707/016/ MDT CU ALQDS CI INVADING LW STRA/FG OVR OCN DSNT ENE-E MSTLY CLR SKY DSNT N-NE LGT DSNT HZ WND 12V21/ 8/404 58011 10076 20059 WEATHER SUMMARY FOR MONDAY, MAY 6, 2013 TEMPERATURE (DEGREES F) MAX.....66 NORMAL.....64 MIN.....40 NORMAL.....45 MEAN....53 NORMAL.....54 DEPARTURE FROM 30-YEAR NORMAL....................-1 TOTAL DEPARTURE FOR THE MONTH....................-9 [-1.7 DEGREES/DAY] HEATING DEGREE DAYS TOTAL HEATING UNITS FOR YESTERDAY............12 DEPARTURE..........+1 TOTAL HEATING UNITS FOR THE MONTH............78 DEPARTURE..........+7 TOTAL HEATING UNITS FOR THE SEASON.........5600 DEPARTURE........-506 TOTAL HEATING UNITS LAST SEASON TO DATE....4808 DIFFERENCE.......+792 PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY...............17 S AT 8:05 P.M. AERO....................18 S AT 7:28 P.M. ASOS....................20 S AT 9:26 P.M. DAVIS...................19 S AT 8:04 P.M. RMY: 20 THE FASTEST MILE FOR YESTERDAY.............15 S AT 9:35 P.M. MAXIMUM 2-MINUTE ASOS AVERAGE..............15 S AT 8:05 P.M. MAXIMUM 2-MINUTE DAVIS AVERAGE.............14 S AT 9:34 P.M. AVERAGE WIND SPEED AND DIRECTION..........6.5 S ASOS...................6.4 DAVIS..................5.9 SSE [156 deg] PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....0.00 DEPARTURE...........-0.12 ASOS..............0.00 TOTAL PRECIPITATION FOR THE MONTH.........Trace DEPARTURE...........-0.74 ASOS..............0.00 TOTAL PRECIPITATION FOR THE YEAR..........16.38 DEPARTURE...........-2.91 ASOS..............N/A* *ASOS malfunctioned during storm on 2/8-9, leading to erroneous totals SNOWFALL (INCHES) THROUGH THIS MORNING (EST) TOTAL SNOWFALL 24 HRS ENDING 7 A.M.........0.0 DEPARTURE.............0.0 TOTAL SNOWFALL FOR THE MONTH...............0.0 DEPARTURE.............0.0 TOTAL SNOWFALL FOR THE SEASON.............99.0 DEPARTURE...........+36.3 PRELIMINARY CLIMATE SUMMARY FOR MAY 2013 CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane wind recording system gust RMY: RMY = R.M. Young wind gust recording system added 8/9/2011 TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 5/1 67/45/56/+3/0.00/.../.. 18 E AERO 16 MPH E RMY 17 5/2 75/43/59/+6/T/.../.. 29 NE AERO 26 MPH NE RMY 29 5/3 54/42/48/-5/0.00/.../.. 24 NE AERO 25 MPH NE RMY 28 5/4 55/40/48/-6/0.00/.../.. 21 NE AERO 23 MPH NE RMY 23 5/5 58/37/48/-6/0.00/.../.. 17 ENE AERO 17 MPH ENE RMY 20 5/6 66/40/53/-1/0.00/.../.. 17 S AERO 18 MPH S RMY 20 5/7 morning low temp: 50F; the normal low is now 45F DAILY RECORDS FOR MAY 2013 None so far. DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR MAY 7 HIGH 93F IN 1930 LOW 33F IN 1970 PRECIP 1.19 INCHES IN 2005 SNOWFALL TRACE IN 1967 PEAK GUST 66e MPH WNW IN 1940 RECORDS FOR MAY 8 HIGH 89F IN 2000 LOW 29F IN 1956 PRECIP 1.48 INCHES IN 1886 SNOWFALL TRACE IN 1898, 1947 PEAK GUST 68e MPH NNW IN 1943 TODAY'S REPORT PREPARED BY: Sean Fankhauser