Near term - through 9pm this evening -
...Skies are mostly clear this morning besides some high cirrus clouds. There were a few areas of patchy fog, where temperatures fell below 60 (to the dew point). Any fog will burn off before 8:30am. For central and southern New England, skies will remain mostly sunny throughout the day as a moderate cap stops any convection from developing. A short wave will move south into Maine today, breaking the cap and bringing scattered thunderstorms, some severe. Already an area of showers and embedded thunderstorms is affecting northwest Maine. This activity will remain in northern Maine and northern New Hampshire through the evening.

Temperatures in Keene started out at 59 this morning. But have already quickly risen up to 70 degrees. Temperatures will continue to rise through today, along with dew points as a moist airmass works into the region. Currently Keene has a 64 degree dew point. The highest temperatures this morning can be found in eastern MA and southeastern NH where they will be approaching 80 by 9am. Further east, along the immediate coast, a sea breeze will keep temperatures in check throughout most of the day. Central MA up into south central NH will be the focus for the hottest temperatures of the day, with highs in the mid to upper 90's and heat indices possibly reaching 100. In Keene, Highs will reach the low 90's, although GFS MOS data advertises a high of 95. The record for today is 96, but probably will not be reached. The combination of air temperatures between 90 and 95 and dew points in the mid 60's will boost heat indices up to 94 to 98 this afternoon. Temperatures will begin to fall after 4pm, backing to around 80 by 9pm.

Short term - Tonight through Wednesday night -
...Skies may see some increasing high clouds towards midnight, but that should clear up towards dawn. Dew points in the 60's will assist in the production of patchy fog, with a haze developing towards daybreak. Radiational cooling will assist for a considerable fall in overnight temperatures down to a low in the lower 60's. However, temperatures will rebound quickly on Wednesday under mostly sunny skies. There is still uncertainty of which day will feature the hottest temperatures. 850mb temperatures will reach 19C to 20C days. It is a matter of which will have maximum heating. Latest MOS forecasts place highs at 96 for Keene. However, cloud cover in the afternoon may stunt the everising temperatures a bit. The short wave dropping south into ME today will continue southward slowly on Wednesday. It may be enough forcing to break the cap in the afternoon, in which case a significant bout of severe weather is possible. It is still possible also that the cap is not broken, in which case skies would remain mostly sunny, with maximum daytime heating bringing highs into the mid 90's. Either way Wednesday afternoon and evening is a time period that has a lot of uncertainties and that needs to keep an eye on. The record high for June 27 is 94, which could be broken given maximum heating. Wednesday will have higher dew points, possibly reaching or exceeding 70 in the late morning and afternoon. This could force two hour heat indices near 100 with a max between 100 and 104. Wednesday will have the best potential for heat advisory criteria across southern New England.

Any thunderstorm activity will die off by 9pm. Skies will remain partly cloudy Wednesday night, with widespread haze and patchy fog forming towards morning. High dew points will keep temperatures up in the upper 60's to near 70.

Long term - Thursday through Monday 7/2 -
...Thursday, humidity stays through the afternoon, however less heating, as front crosses early with increasing cloud cover in the late morning. Models have trended closer to the GFS later solution with a later frontal passage, which would allow a bit more heating and better severe weather potential. Further east, where the front crosses later in the day, there is a shot at 90, which would conclude a 3 to 4 day heat wave. Right now, looks like showers and thunderstorms will cross the area around noontime. While these thunderstorms will very likely be strong to severe, as the strong boundary cuts through a very unstable airmass, the early timing may save Keene from the worst of the storms as peak heating is far from reached. Main threat will be for areas to our east.

850mb temperatures will be falling through the day, dropping back to aournd 10C by Thursday night. Lows will fall down into the low to mid 50's, along with dew points down around 50. Drier and cooler air moves in at the surface for Friday, Saturday, and Sunday. Skies will be mostly sunny to sunny, with temperatures held back to the mid 70's and lows in the lower 50's.

The one point of interest beyond day 4 is Saturday and Sunday, as a short wave moves southeastward behind the departing storm. Cold air aloft could provide for enough instability for showers and thunderstorms, some with gusty winds and small hail. The timing of the storms has shifted over to Saturday night and Sunday, which may leave Satuday daytime dry. Another cool down moves in on Sunday with highs only in the lower 70's. Temperatures will begin to slowly rebound on Monday with highs reaching the mid 70's under partly cloudy skies.

&&

Forecaster: SL
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Weather history:
6/26 in Keene, NH:
average high is 78, record is 96
average low is 53, record is 36

Astronomy:
Sunrise: 5:11AM Sunset: 8:32PM
Moonrise: 5:18PM Moonset: 1:53AM
Length of visible light: 16 hours 31 minutes
Length of day: 15 hours 20 minutes
-Tomorrow will be 22 seconds shorter

6/26 across the United States:
1888 - Residents of New York suffered through a record heat wave. Daily average temperatures were above 80 degrees for fourteen straight days. The heat wave was a sharp contrast to the severe blizzard in March of that year, which buried the city under nearly two feet of snow. (David Ludlum)

1977 - "The Human Lightning Conductor", park ranger Roy C. Sullivan, was struck by lightning for the seventh time. He was first hit in 1942, then again in 1970, 1972, 1973 and 1976. (The Weather Channel)

1983 - Record heat prevailed from Texas to Michigan. Alpena MI hit 98 degrees. (Sandra and TI Richard Sanders - 1987)

1985 - A spectacular early morning waterspout developed at 5:20 AM (MST) from a stationary thunderstorm over the south end of the Great Salt Lake in Utah. It was visible 20 miles away, and lasted four minutes. (The Weather Channel)

1987 - Hot weather prevailed in the Pacific Northwest. Afternoon highs of 88 degrees at Seattle, WA, 103 degrees at Medford, OR, and 111 degrees at Redding, CA, were records for the date. Cloudy and cool weather prevailed in the northeastern U.S. The high at Boston, MA, was just 60 degrees. (The National Weather Summary)

1988 - Thirteen cities in the southeastern U.S. reported record high temperatures for the date. In Montana, the record high of 102 degrees at Billings, MT, was their fifteenth of the month, and the high of 108 degrees at Glasgow MT equalled their record for June. Thunderstorms in the Atlantic Coast Region produced wind gusts to 102 mph at Tall Timbers MD. (Storm Data) (The National Weather Summary)

1989 - Thunderstorms produced severe weather from the Central Plains to the Middle Mississippi Valley. There were 129 reports of severe weather during the day and night. Thunderstorms in Kansas produced wind gusts to 90 mph at Liberal, and hail four inches in diameter at Quinter. Thunderstorms in Wisconsin spawned a tornado at Lake Delton injuring four persons. Lightning struck and killed a woman at Junction City, KS, who had gotten out of her car to photograph the lightning. (The National Weather Summary) (Storm Data)crossed northern Mexico), began to spread heavy rain into southeast Texas and southwest Louisiana. (The National Weather Summary)

Yesterday (6/25):
Keene: H 86, L 55