BLUE HILL METEOROLOGICAL OBSERVATORY MILTON, MASSACHUSETTS 02186 ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY FRIDAY, JULY 13, 2007 ALL TIMES ARE IN EASTERN STANDARD TIME A strong inversion this morning kept the observatory warmer than local low elevations and helped to trap a smog layer over Boston and Providence that was clearly visible from the tower at 7 am. By mid-morning the strong July sun had broken the inversion, resulting in lowering visibilities and developing small cumulus clouds. Early-afternoon temperatures at the observatory are in the mid-eighties with plenty of sunshine. The weekend should hold more of the same. Lots of sun and seasonably warm with some chance for scattered afternoon showers and storms. Today's observations: 7 A.M. Weather: Scattered thin cirrus and a smoke layer along horizon Temperature: 69F, Dew point: 56F, Wind: S at 10kts Sea-level pressure: 29.91 inches Hg, rising Visibility: 65 miles 6-hour min temp: 65F 24-hour rainfall: 0.01 inch BHO SA 1155 250 SCT 65 128/69/56/1810/991/ FEW THN CI OVHD FEW AC DSNT E THN K ALG HRZN DSTN N AND DSTN E/ 8/011 53006 10069 20062 10 A.M. Weather: Scattered cirrus, few small cumulus NW-NNE Temperature: 79F, Dew point: 57F, Wind: SSW at 12 kts Sea-level pressure: 29.89 inches Hg, falling Visibility: 40 miles BHO SA 1455 250 SCT 40 122/79/57/2112/989/ CI OVHD FEW SML CU NW-NNE 19V24/ 8/001 58006 1 P.M. Weather: Scattered cirrus, few small cumulus all quadrants Temperature: 82F, Dew point: 49F, Wind: WSW at 20G25 kts Wind: Direction variable SSW-W Sea-level pressure: 29.86 inches Hg, falling Visibility: 30 miles BHO SA 1755 250 SCT 65 SCT 30 113/82/49/2420G25/986/ CI OVHD FEW SML CU ALQDS MDT CU DSNT NE-NNE WND 20v27/ 8/201 57009 10084 20069 WEATHER SUMMARY FOR THURSDAY, JULY 12 TEMPERATURE (DEGREES F) MAX.....81 NORMAL.....81 MIN.....64 NORMAL.....62 MEAN....73 NORMAL.....72 DEPARTURE FROM 30-YEAR NORMAL........+1 TOTAL DEPARTURE FOR THE MONTH.......-9 (-0.8 DEGREES/DAY) PEAK GUST AND AVERAGE WIND SPEED (MPH) PEAK WIND GUST FOR YESTERDAY..............27 WNW AT 7:33 A.M. AEROVANE...............26 NW AT 7:01 A.M. ASOS...................N/A # DAVIS..................27 NW AT 7:01 A.M. FASTEST MILE FOR YESTERDAY................18 WNW AT 6:39 & 8:05 A.M. MAXIMUM 2-MINUTE ASOS AVERAGE.............N/A # MAXIMUM 2-MINUTE DAVIS AVERAGE............20 WNW AT 7:33 A.M. AVERAGE WIND SPEED AND DIRECTION........ 10.7 W ASOS...................N/A # DAVIS................ 11.1 W [273 deg] # ASOS WINDS SWITCHED OFF BY NWS 6/6, IT IS NOT KNOWN WHEN THAT DATA WILL RESUME 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 JULY...............0.99 DEPARTURE.....-0.47 ASOS..............0.91 TOTAL PRECIPITATION FOR THE YEAR..........27.97 DEPARTURE.....+0.96 ASOS FOR YEAR..........27.32 PRELIMINARY CLIMATE SUMMARY FOR JULY 2007......CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SUN(MIN.)/SUN(%)/ PEAK GUST/AERO GUST AERO: Aerovane recording wind system when significant TSTM: Thunderstorm day ....: Data not yet available 7/1 70/52/61/-9/0.02/649/71/28 W 7/2 73/50/62/-8/0/841/92/ 29 WNW 7/3 75/53/64/-6/0/839/92/ 23 NW 7/4 78/58/68/-2/0.09/465/51/45 SSE 7/5 80/61/71/ 0/0.25/383/42/38 SSE TSTM ** 7/6 83/62/73/+2/0.01/482/53/46 WNW TSTM 7/7 81/60/71/0/0/.../../ 32 WSW 7/8 90/62/76/+5/0.41/.../../36 NW Aero 33 MPH TSTM 7/9 86/61/74/+3/0.20/354/39 27 NNE TSTM 7/10 80/62/71/0/0/680/75 27 S 7/11 84/70/77/+5/T/393/43 32 S 7/12 81/64/73/+1/.01/810/90 27 WNW 7/13 morning low temp. 62 deg; normal now 62 deg. ** precip on the 5th was erroneously reported as 0.24; it has been corrected to 0.25 in. NEW DAILY RECORDS FOR JULY 2007: None to date DAILY EXTREMES Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated): RECORDS FOR JULY 13 HIGH 95F IN 1894 LOW 52F IN 1888, 1895, 1939, 1973 PRECIP 3.54 INS IN 1996 WIND 55 MPH SE IN 1996 RECORDS FOR JULY 14 HIGH 98F IN 1952 LOW 51F IN 1895, 1937 PRECIP 1.97 INS IN 1960 WIND 110e MPH NW IN 1942 [RECORD FOR MONTH] TODAY'S REPORT PREPARED By: Nate Magee and Eli Melaas