This upcoming week will be very active across New England and in fact across the eastern two thirds of the nation. The western heat ridge will finally break down somewhat, with a high building across te southern Plains and southeast and a heat transfer from the west. Tomorrow, this heat will be introduced to the northeast as a warm front associated with a low entering southwestern Alberta moves northeast. Now begins the active week of weather...

1. Heat on Sunday: Warm front moves northeast, 850mb temps bumped up to 20 to 21C - Highs in the upper 80's in Keene (slight shot at 90), with low to mid 90's across SNE.

2. Severe thunderstorms on Sunday: Low chance, atmosphere will be capped and instability will likely not be enough to break through until too late. However, winds will be adequate as the front crosses, creating possibly enough lift for a few isolated storms. Any that do develop will thrive, likely becoming severe with main threat being wind, moderate threat for hail, although with shear, tornado threat does exist.
SPC:

   ...UPSTATE NY EWD INTO SRN NEW ENGLAND...
   A WARM FRONT IS FORECAST TO EXTEND FROM UPSTATE NY EWD ACROSS NRN
   VT/NH AT LATE AFTERNOON. MID LEVEL WNWLY WINDS NEAR 50 KT...WITH
   WSWLY WINDS IN THE BOUNDARY LAYER...WILL SUPPORT 40-50 KT OF DEEP
   LAYER SHEAR. THE MID LEVEL IMPULSE...FORECAST TO MOVE THROUGH THE
   GREAT LAKES AREA TONIGHT...WILL APPROACH THIS REGION LATE
   AFTERNOON...WITH WARM FRONT LIKELY TO PROVIDE FOCUS FOR CONVECTIVE
   INITIATION. DESPITE A RELATIVELY DRY BOUNDARY LAYER...DEWPOINTS IN
   THE LOWER 60S...BY THE TIME STORMS DEVELOP/MOVE INTO THE REGION
   ...AIR MASS SHOULD BECOME WEAKLY TO MODERATELY UNSTABLE. THIS MAY
   SUPPORT A CLUSTER OF STRONG TO SEVERE STORMS MOVING ESEWD ACROSS THE
   REGION LATE AFTERNOON/EARLY EVENING HOURS.

3. Heat on Monday: 850mb temps up to 21 to 22C with partly to mostly sunny skies, should reach about 2C under max potential. Looking at lower 90's in Keene and W MA, mid 90's E MA and RI, and upper 90's possible for C/N CT, S/C MA. Humidity will not be as significant as the last heat wave, with dew points generally 64 to 68, but still will support heat indices of 93 to 95 in Keene, maxing at 102 to 104 in CT and S MA.

4. Severe thunderstorms on Monday: Warm front sinks south as a cold front Sunday Night, moves back north as a warm front once again creating enough lift and good wind profiles for severe weather potential. However, again a cap will be present, reducing the chances for thunderstorms development. instability will be slightly greater than Sunday so the cap may break in the afternoon. Monday will likely be more active severe weather wise than Sunday.
SPC:

   ...NEW ENGLAND SWWD TO LOWER GREAT LAKES...
   PROGRESSIVE MID/UPPER LEVEL TROUGH EXPECTED TO MOVE INTO ONTARIO/NRN
   GREAT LAKES REGION ON DAY 2 /SUNDAY/ SHOULD REMAIN NORTH OF THE
   INTERNATIONAL BORDER ON DAY 3 /MONDAY/.  DESPITE LITTLE...IF ANY...
   HEIGHT FALLS FORECAST ACROSS NEW ENGLAND...STRONG WLY MID LEVEL
   WINDS WILL REMAIN ACROSS THIS REGION CONTRIBUTING TO STRONG DEEP WLY
   SHEAR.  SURFACE COLD FRONT ATTENDANT WITH THE UPPER TROUGH IS
   PROGGED TO MOVE SSEWD ACROSS MUCH OF NEW ENGLAND AND THE LOWER GREAT
   LAKES ON MONDAY.  AIR MASS IN ADVANCE OF THIS SYSTEM IS EXPECTED TO
   BECOME MODERATELY UNSTABLE AND THUS SUPPORT TSTM DEVELOPMENT WITH
   ACTIVITY LIKELY BECOMING STRONG TO SEVERE.  THIS ACTIVITY MAY REACH
   SRN NEW ENGLAND TO SRN PA LATER MONDAY EVENING...PRIOR TO DIURNAL
   DECREASE IN INSTABILITY.

5. Heat on Tuesday: Front to the north will keep 850mb temps up around 20C, and with solar mixing, temperatures will climb to the mid 80's before noontime. However, a trough along the eastern Appalachian Mts will allow cloud development, pushing temperatures back a little. Expect highs in Keene generally 88 to 90.

6. Severe thunderstorms on Tuesday: Cap will remain no longer. Colder air moves in at the mid levels, with increasing lapse rates. CAPE should be up possibly 3000+ j/kg. Tuesday could turn out to be a significant severe weather day.

7. Wednesday: Front sinks south of the region Tuesday night and Wednesday. Somewhat cooler air will move in.

8. Thunderstorms on Thursday: This will be the final passage of this front. Starting north of the area from Wednesday Night, it will sweep south across the region on Thursday. The air will generally be more stable so not expecting any significant severe weather as of now. Still could get some thunderstorm action however.