2.23 PM All Zones: Very warm weather has arrived

A well discussed period of above normal temperatures has arrived throughout the Eastern United States today, and is gradually making its way northwards from the Mid Atlantic States into the Northeast States as well. A warm front, situated over the Delaware River Valley this morning, has shifted northwards passing through much of New Jersey. The front will gradually continue its trek northwards as the afternoon goes on today and will continue into New England.

This morning, low clouds and fog were widespread throughout the Mid Atlantic and New England as a cool flow on the north side of a warm front allowed for moisture to remain trapped in the atmosphere’s lower levels. The fog eventually lifted this afternoon and a change in wind direction will continue to aid in warmer air surging northwards. The fog may return tonight for some locations, particularly near the coast, as warm air continues to advect towards the area.

NAM model showing temperatures 20-30 degrees above normal in the Northeast on Friday evening.

NAM model showing temperatures 20-30 degrees above normal in the Northeast on Friday evening.

Friday looks very likely to be a warm day throughout the Northeast states as warmer air continues to advect into the area both aloft and at the surface. Temperatures, after some morning clouds, will surge into the 60’s and even lower 70’s — more than 25 degrees above normal in many locations! Record high temperatures are likely to be challenged, particularly in the interior Northeast.

The warmth will continue through Friday evening and Saturday morning, as a storm system begins to organize over the Great Lakes. A cold front is expected to sweep eastwards from the Mississippi River Valley and Ohio Valley towards the Northeast states, but won’t arrive until Saturday afternoon. With its approach will come an increase in both forcing/lift and instability — which while weak, will support the development of some showers and storms.

The combination of weak instability and favorable winds with forcing for precipitation will aid in the development of showers and embedded storms on Saturday, sweeping eastwards through the Northeast states. The best opportunity for thunderstorms will remain inland, over the interior, but heavier showers will still sweep eastwards through the entire region with the cold front. The front will bring an end to very warm temperatures as cooler air surges in behind it.

NAM model showing storms moving through the Northeast US on Saturday afternoon.

NAM model showing storms moving through the Northeast US on Saturday afternoon.

Showers and storms should shift offshore by the mid evening hours, reaching the Western Atlantic Ocean, with a significant and noticeable drop in temperature on Saturday from late afternoon into evening. A much cooler airmass will surge into the region, bringing temperatures below normal for this time of year by Sunday morning. While short lived, the drop will certainly feel likely a noticeable shock to the system.

Thereafter, impacts from multiple storm systems appear possible over the next 10-15 days as the Pacific Ocean becomes active once again and sends disturbances into the USA. Stay tuned for further updates and information on their presence and potential impacts.