5.15 Midday Zones Update: Summer Warmth Midweek, Cooler Weekend

Happy Monday! Hope you had a lovely weekend! A coastal storm that impacted the region over the weekend, is still east of New England today. Clouds from this low are moving through parts of the region. As the storm slowly moves out further into the Atlantic, clouds will gradually clear for more sunshine. High temperatures this afternoon will be in mid-upper 60s. Overall it will a pretty decent day. But a tight pressure gradient behind this low will cause northwest winds to gust over 30-40mph, through this afternoon.

High pressure will be moving over the region tonight. This will cause more clear skies and calmer winds overnight. Temperatures will drop into upper 40s to lower 50s much of the region. Some interior locations could drop well down into 40s with more radiational cooling overnight.

Then a major warming trend begins on Tuesday, with more mid-level ridge building into region. It will be mostly sunny with high temperatures in the mid-upper 70s,. Even coastal section will be warm, as west-southwest winds will likely hold more sea-breezes till the later in the day. Then mostly clear skies remain Tuesday night. A southwest flow will keep temperatures from falling out the 50s overnight, over most of the region.

Stronger ridging builds over the region Wednesday and Thursday with more southwest winds and 850mb temperatures 16°C and higher. This will support very warm, summery airmass over the region again. Highs will be at least in the mid-upper 80s, away from the coast. But some spots over New Jersey, NYC could see temperatures around 90 degrees, each day. Humidity will be a little  higher. But not too uncomfortable. Sea-breezes may keep areas right along the shores, from rising out of the 70s or lower 80s, each day.

GFS model forecast for Wednesday afternoon with strong mid-upper-level ridge and 850mb temperatures approaching 16°C and 18°C

GFS model forecast with a strong mid-upper-level ridge and 850mb temperatures between 16°C and 18°C over the region on Wednesday

Then a cold front will come through later Thursday and Friday. Depending on frontal timing, the airmass may be unstable enough for some scattered showers and thunderstorms to develop ahead of this front. Some locally heavy downpours and lightning is possible. But a lack of dynamics will not likely support more organized severe weather or another widespread heavy rainfall threat for the region.

Behind this front, a maritime-airmass will come into region. This will support cooler temperatures perhaps back into 60s or 70s for highs by Friday or the weekend. This cold front may slow down just south of the region, Then a wave of low pressure moving along this front may bring more rain or showers to the region by late in the weekend.

Overall, the latest guidance suggest that some high-latitude blocking will return again over next couple weeks. This will support more troughs with periods of cooler or unsettled weather over Northeast and Mid-Atlantic region. So enjoy another taste of summer weather this week. As it will be short-lived again. No prolonged warmth or heat appears to be coming the foreseeable future. Stay tuned for more zone forecast update through this week