Heat Peaks Before a Pattern Change for New England

Today, the heat will likely peak for most in central and southern New England. Temperatures aloft will reach their highest point and the sea-breeze will be mitigated by a stronger westerly flow. With nearly full sun, high temperatures will once again be well into the 90s with some spots potentially reaching the 100° mark across southern and central New England. Overall, conditions for heating will be more favorable than yesterday.

Temperatures aloft will be highly elevated and likely peak this afternoon. Temperatures at the 850mb level, which is about 2,500 feet above sea level, may manage to reach the 30°C (86°F) mark, something that doesn't happen all too often in New England. Temperatures at about 5,000 feet are likely to reach the 20-22°C (68-71°F) range. For some kind of reference, Mt. Washington's summit stands at 6,288 feet. Their all-time record high is 72°; today is forecast to reach the mid 60s at the summit.

Below: Euro showing temperatures at the 925mb level (about 2,500 feet above sea level):

Yesterday, a few daily record high temperatures were tied or broken across the region. More are likely to fall today, especially as the full force of the heat reaches all the way to the coastline. Boston and Burlington will make a run at their all-time hottest June temperature on record, both of which is 100°.

Boston is more likely to reach that mark with a forecast of 102°. Burlington's forecast is currently 97°. Boston's all-time high temperature record is 104°, set in 1911, which is highly unlikely to be reached, though not impossible. For the curious ones, New England's all-time record is 107°, set on "Hot Saturday" in 1975. This record should be plenty safe.

Below: FV3 showing potential temperatures this afternoon:

On top of the heat is, of course, the humidity. Dew point levels will be in the low to mid 70s through the day, which is tropical-like. Factoring this in, feels-like temperatures will reach into the 105-110° for many communities in southern and central New England. These high dew points led to a very warm morning, which will help jump start the warming process through the afternoon.

Later today, a cold front will begin to approach northern New England. This front will eventually bring relief to New England, but will likely remain hung up in Canada. It may allow for isolated thunderstorms across northern New England in the afternoon, but lift and shear will be weak. Dry air aloft will also make thunderstorm development hard, but strong heating and high instability may allow for a few storms. Any storm that manages to form could become strong. It's not outside the realm of possibility that a rogue storm or two drops farther south in New England, but don't exactly count on it.

Below: HRRR showing potential weather late this afternoon:

On Wednesday, that cold front will slowly sag through New England as the heat dome begins to get suppressed to the south and west. This will bring lowering temperatures and humidity, though it will take some time for these changes to be felt at the surface, so another pretty hot day is on tap for southern and central New England. Wednesday will act as a transition day from a heat dome to a stalled frontal boundary set up. While this will be a dry frontal passage for most, a few pop-up showers or storms will be possible in the afternoon. Cloud cover will also be increased.

That cold front will stall to the south of New England for the remainder of the week. This will bring cooler, cloudier and more unsettled weather back to the region. Mostly cloudy skies with scattered shower chances will be around Thursday through Saturday. As of now, shower coverage looks to be generally higher on Friday and Saturday than Thursday. Shower coverage will likely be highest across the northern tier of New England through this period. Highs will drop back into the 70s as an onshore flow will dominate. Coastal areas may have trouble breaking out of the 60s Friday and Saturday.