DAYS 1-5 (JUNE 30 – JULY 4)
Upper high pressure to the west expands to the east to impact our region with hotter weather Wednesday through Friday. The transition day into that set-up is today as a disturbance tracks to our north and its warm front moves across the region later today and tonight. In the evolving northwesterly air flow with this pattern, the disturbance and warm front will generate a thunderstorm cluster that will make a run at our region, but likely be weakening and breaking up as it moves into and across the region this evening / tonight. There is a shower and thunderstorm chance, but I’m not expecting intense storms or severe weather in the WHW forecast area. During the Wednesday through Friday period we see highest heat and humidity in the region, and will also still have to keep an eye upstream for “ridge rider” shower and thunderstorms or their remnants. The overall set-up does produce a rather strong cap in the atmosphere that may limit the ability of storms to survive the trip across our region, or develop around here. However, it’s borderline, and storms cannot be completely ruled out on any of those days / nights. Our transition day out of the hot spell appears to be Saturday, July 4, when there is a better shot at a passing shower or thunderstorm as a cold front drops through the region from north to south. At day 5, the confidence on timing of this front is not high, but I am leaning toward the first half of the day for a frontal passage over later on. This may also limit the ability for storms to be stronger, but could still impact some outdoor plans. Obviously this will be closely monitored. Behind the front I’d expect a wind shift to north or northeast in response to high pressure in eastern Canada, and this would provide heat relief.
TODAY: Sunny start, then variably cloudy. A shower or thunderstorm is possible afternoon and evening. Highs 82-89. Dewpoint 60+. Wind W 5-15 MPH.
TONIGHT: Partly cloudy. A shower or thunderstorm possible. Lows 64-71. Dew point 60+. Wind W up to 10 MPH.
WEDNESDAY: Partly cloudy. An isolated thunderstorm possible. Highs 89-96. Dew point 65+ Wind W 5-15 MPH.
WEDNESDAY NIGHT: Partly cloudy. An isolated shower or thunderstorm possible. Lows 67-74. Dewpoint 65+. Wind W to SW up to 10 MPH.
THURSDAY: Mostly sunny. Highs 92-99 except 80s Cape Cod. Dew point 65+. Wind SW to W 5-15 MPH.
THURSDAY NIGHT: Partly cloudy. Lows 71-78. Dew point 65+. Wind SW to W 5-15 MPH.
FRIDAY: Partly sunny. A thunderstorm possible. Highs 90-97 except 80s Cape Cod. Dew point 65+. Wind SW to W 5-15 MPH.
FRIDAY NIGHT: Partly cloudy. Lows 71-78. Dew point 65+. Wind W 5-15 MPH.
SATURDAY (INDEPENDENCE DAY): Variably cloudy. Chance of showers and thunderstorms especially morning-midday. Highs 82-89. Dew point 65+ then lowering. Wind W shifting to NE 5-15 MPH, higher gusts possible.
DAYS 6-10 (JULY 5-9)
Maritime air mass keeps it modified warm with moderate humidity July 5-6. A disturbance or two can bring a shower and thunderstorm threat heading into the middle of next week with more seasonably warm temperatures.
DAYS 11-15 (JULY 10-14)
Overall pattern features west to east flow with a few passing disturbances bringing shower and t-storm opportunities, but no prolonged unsettled weather. Temperatures slightly variable but averaging near normal overall.