BLUE HILL METEOROLOGICAL OBSERVATORY  MILTON, MASSACHUSETTS ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA DAILY DISCUSSION AND CLIMATE SUMMARY TUESDAY, MAY 5, 2015     ALL TIMES ARE IN EASTERN STANDARD TIME FIRST 80 DEGREE DAY MONDAY IS FOLLOWED UP BY WARM OVERNIGHT AND LIGHT SHOWERS TUESDAY MORNING  Temperatures skyrocketed yesterday following an overnight low of 47F. Temperatures climbed to an afternoon maximum of 83F, creating a remarkable temperature range of 36 degrees in less than 12 hours.  Overnight temperatures fell only to 63F, and continued to drop as light rain showers and a weak cold front moved through the region. The low temperature this morning was warmer than the existing record high minimum temperature for May 5 of 59F set in 1887 and 1949, though it may get colder than this before the end of the day today. By the 1:00 PM EST observation sun had returned along with warming temperatures, hitting a maximum of 73F. Hazy conditions had reduced visibility to just 30 miles in all directions. Showers this morning totaled 0.03 inches of new rain. PRELIMINARY STATS FOR APRIL 2015 TEMPERATURE, Deg. F Avg. Max. 55.9 [+0.2] Avg. Min. 38.4 [+0.7] Mean      47.2 [+0.5] Corrected mean: 46.7  Max. for month: 69 on 4/13 Min. for month: 26 on 4/1 HEATING DEGREE DAYS  Total heating units: 528 [-23]     Total for the season: 6271 [+236] Total for last season: 6171 PRECIPITATION, Inches Total: 3.33 [-1.22] Greatest in 24 hrs: N/A SNOWFALL, Inches Total: Trace [-3.0] Greatest in 24 hrs: Trace on 4/8 WIND, mph Avg. uncorrected wind speed: 12.6 Avg. corrected wind speed: 13.0 Prevailing wind direction: NW @ 16% Peak gust and direction: 54 NW on the 4th SUNSHINE: Astronomical total minutes:   12386 / 24083 or 51% Campbell-Stokes card minutes: 11946 / 23250 or 51% Today's Observations: 7 A.M. Weather: Light rain showers begin 6:40 AM EST, broken altocumulus, overcast nimbostratus Temperature: 65F; Dew Point: 48F; Wind: W at 9 kts, Sea-level pressure: 30.18 ins. Hg, rising then more quickly Visibility: 35 miles, except 20 miles WSW-NE, hazy and obscured by rain showers 6-hr Max temp: 66F 6-hr Min temp: 63F 24-hr precip: Trace BHO SA 1155 E110 BKN 150 OVC 35RW- 221/65/48/2609/018/ RW-B40 VSBY WSW-NE 20 MI HAZY PRCP VRY LGT/ 8/02/ 53022 MANUAL 6000/ 10066 20063   10 A.M.  Weather: Showers distant ENE-ESE and SW-WNW, few cumulus WNW-NNE, overcast altostratus Temperature: 62F; Dew Point: 56F; Wind: estimated SW at 4 kts, Wind Speed: Light  Sea-level pressure: 30.22 ins. Hg, rising, then more quickly Visibility: 35 miles, except 20 miles SW-WNW, hazy and distant showers 3-hr precip: 0.02 inches BHO SA 1455 E70 OVC 35 233/62/56/E2304/022/ VSBY SW-WNW 20 MI SHWRS DSNT ENE-ESE AND SW-WNW FEW CU DSNT WNW-NNE THN FG ALQDS WND LGT/  8/12/ 53012 ASOS 60002 MANUAL 60002 1 P.M. Weather: Thin broken cirrus, few cumulus in all direction, few altocumulus lenticularis NNE-ESE Temperature: 73F; Dew Point: 53F; Wind: estimated SSE at 3 kts, Wind Speed and Direction: Light and Variable  Sea-level pressure: 30.20 ins. Hg, rising, then falling and lower Visibility: 30 miles, hazy    6-hr Max temp: 73F 6-hr Min temp: 61F 6-hr precip: 0.03 inches  BHO SA 1755 E270 -BKN 30 228/73/53/E1503/020/ FEW CU ALQDS FEW ACSL DSNT NNE-ESE HAZY WND LGT AND VRB/ 8/141 58005 ASOS 60003 MANUAL 60003 10073 20061  SUMMARY FOR MONDAY, MAY 4, 2015     TEMPERATURE (DEGREES F) MAX.....83   NORMAL.....63 MIN.....47   NORMAL.....44 MEAN....65   NORMAL.....54 DEPARTURE FROM 30-YEAR NORMAL......................+11 TOTAL DEPARTURE FOR THE MONTH.......................+5 [+1.1 DEGREES/DAY]    HEATING DEGREE DAYS (SEASON JUL TO JUN) TOTAL HEATING UNITS FOR YESTERDAY...............0  DEPARTURE..........-12 TOTAL HEATING UNITS FOR THE MONTH..............42  DEPARTURE...........-7     TOTAL HEATING UNITS FOR THE SEASON...........6313  DEPARTURE.........+230 TOTAL HEATING UNITS LAST SEASON TO DATE......6206  DIFFERENCE........+107 PEAK GUST AND AVERAGE WIND SPEED (MPH)  PEAK WIND GUST FOR YESTERDAY..................39 SSW   AT   4:33 P.M.                          ASOS.......................46 SSW   AT   4:33 P.M.                           DAVIS......................45 SSW   AT   5:28 P.M. RMY 45  FASTEST MILE FOR YESTERDAY....................36 SSW   AT   4:34 P.M.   MAXIMUM 2-MINUTE ASOS AVERAGE.................36 SSW   AT   4:34 P.M.          MAXIMUM 2-MINUTE DAVIS AVERAGE................34 SSW   AT   4:34 P.M.    AVERAGE WIND SPEED AND DIRECTION............16.3 SSW                    ASOS.....................16.1                         DAVIS....................15.1 SSW [202 degrees]  * Last of several occurrences...   PRECIPITATION (INCHES) THROUGH THIS MORNING (EST) TOTAL PRECIPITATION 24 HRS ENDING 7 A.M....TRACE  DEPARTURE.....-0.12                          ASOS...............0.00 TOTAL PRECIPITATION FOR THE MONTH...........0.00  DEPARTURE.....-0.49                            ASOS...............0.00  TOTAL PRECIPITATION FOR THE YEAR...........17.92  DEPARTURE.....-0.99                          ASOS................N/A ***  *** ASOS annual totals not available due to erroneous readings 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..............150.8  DEPARTURE....+88.1  PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY GUST RMY:  R.M. Young wind gust recording system  TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 4/1  44/26/35/-6/0.00/0.0/748/98              30 WNW RMY 31  4/2  59/29/44/+3/T/0.0/375/49                 39 SSW RMY 43  4/3  56/47/52/+10/0.02/0.0/000/00             36 SW  RMY N/A 4/4  49/32/41/-1/..../0.0/501/65              54 NW  RMY 64  TSTM 4/5  47/30/39/-4/..../0.0/464/60              40 W   RMY 45 4/6  48/33/41/-2/0/00/0.0/544/70              18 NE  RMY N/A   4/7  39/34/37/-6/..../0.0/000/00              21 NE  RMY N/A 4/8  41/32/37/-7/..../T/000/00                30 ENE RMY 32 4/9  35/32/34/-10/..../0.0/000/00             31 ENE RMY 32 4/10 53/35/44/-1/..../0.0/000/00              31 SW  RMY N/A 4/11 56/38/46/+1/0.00/0.0/744/94              39 WNW RMY 48 4/12 68/35/52/+7/0.00/0.0/762/96              23 WNW RMY 23   4/13 69/47/58/+12/0.00/0.0/764/96             35 SSW RMY N/A 4/14 65/51/58/+12/0.05/0.0/072/09             37 SSW RMY N/A 4/15 67/45/56/+9/0.00/0.0/786/98              32 NW  RMY 33 4/16 64/42/53/+6/0.00/0.0/765/95              31 S   RMY 21 4/17 64/45/55/+8/0.05/0.0/065/08              31 SSW RMY 32 4/18 64/43/54/+6/0.00/0.0/770/95              31 N   RMY 36  4/19 55/39/47/-1/0.00/0.0/724/89              25 NNW RMY N/A 4/20 55/38/47/-2/..../0.0/000/00              36 SE  RMY 40 4/21 67/51/59/+10/..../0.0/417/51             30 SSE RMY N/A TSTM 4/22 67/45/56/+7/0.03/0.0/632/77              44 SSW RMY 52 4/23 49/34/42/-8/0.00/0/0/362/44              32 W   RMY N/A  4/24 50/32/41/-9/0.00/0.0/562/68              32 NW  RMY 36   4/25 56/30/43/-7/0.00/0.0/638/77              26 NW  RMY 29 4/26 54/39/47/-4/0.00/0.0/258/31              17 NW  RMY N/A 4/27 56/42/49/-2/..../0.0/125/15              30 NW  RMY N/A 4/28 63/39/51/-1/..../0.0/527/63              32 NW  RMY 35  4/29 58/46/52/+0/T/0.0/461/55                 24 ENE RMY 22 4/30 60/42/51/-1/0.00/0.0/320/38              21 NE  RMY N/A PRELIMINARY CLIMATE SUMMARY FOR MAY CALENDAR DAY DATA DATA REPORTED: DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOWFALL/SUN(MIN.)/SUN(%)/ PEAK GUST/RMY GUST RMY:  R.M. Young wind gust recording system  TSTM: Thunderstorm day (thunder heard some time during day) ....: Data not yet available, records not finalized 5/1 52/37/45/-8/0.00/0.0/.../..               21 NE  RMY 20 5/2 63/35/49/-4/0.00/0.0/.../..               20 S   RMY 20   5/3 74/44/59/+6/0.00/0.0/.../..               22 S   RMY 22 5/4 83/47/65/+11/0.00/0.0/.../..              39 SSW RMY 45 5/5 Low since midnight is 63F; normal low now 45F DAILY RECORDS FOR MAY 2015 NONE SO FAR  DAILY EXTREMES  Temperature and precipitation records back to 1885, and wind records back to 1940 (e = estimated):   RECORDS FOR MAY 5 HIGH 92F IN 1949 LOW 30F IN 1891 PRECIP 2.74 INCHES IN 1922 SNOWFALL 3.0 INCHES IN 1917 PEAK GUST 58 MPH S IN 1966 & 58e MPH SW IN 1976 RECORDS FOR MAY 6 HIGH 90F IN 1930 LOW 29F IN 1891 PRECIP 1.04 INCHES IN 1890 SNOWFALL TRACE IN 1917,1996 PEAK GUST 65 MPH SSE IN 1989 TODAY'S REPORT PREPARED BY: Brian Fitzgerald