6-Day Heat Wave Will Give Way To Prolonged Reprieve

A giant dome of High Pressure situated over the eastern U.S. is going to bring temperatures soaring into the mid to upper 90's in the northeast. Coupled with high humidity levels, this will lead to dangerous and unbearable outdoor conditions. If there has ever been a week to be down the shore, this will by far be the best week to be there. In fact, the last 30 days going back to mid-June have featured above normal temps in the northeastern U.S.

As I stated in my last blog, the Bermuda High is going to stick around for quite awhile and keep our area in a continuous southwesterly flow of gulf warmth streaming into the area. This has indeed been prevalent and has called for frequent days of heat/humidity with occasional days of pop-up rain showers or t-storms. 

The intention of this blog is to bring attention to readers that a pattern change is on the way. The Bermuda High is going to exit stage right which will help upper level trough's entrench themselves over the northeast for the first time in a long time. 

Lets go through a quick look at a couple of models from the 500mb level, starting off with the 12z GFS. 

At 24 hours, this is a clear view of why we are going to be in a 6-day stretch of 90+ degree weather. An area of High Pressure from the tropics has formed over the Ohio Valley region and a "death ridge" has developed over the southeastern U.S. Heat indexes will surpass 100+ degrees and this will surely call for unflattering outdoor conditions. 

As we advance further into the week, at 108 hours, the area of High Pressure has moved east-southeast and a strong upper level low in eastern Canada has helped lower heights over the area and bring temperatures back to normal. One thing also to note: The upper level low in eastern Canada will spawn a cold front, in which we could be dealing with damaging t-storms coming through the northeast. It remains to be seen whether atmospheric conditions are prone for severe weather, but I have a feeling some areas in the northeast by Saturday night into Sunday could be dealing with severe weather. Also notice how a ridge has developed in the western U.S. by this time, allowing northern stream energy to flow downstream into our area which could help spawn off some severe weather. 

By 168 hours, which takes us to early next week, we are still under the influence of a northwesterly flow even though the ridge in the western U.S. has collapsed by this time. 

Looking at the same time frame in the Atlantic Ocean, we can see the Bermuda High is displaced in the central Atlantic and there are positive height anomalies extending into Greenland. The biggest reason for this pattern change is due to the fact that the Bermuda High has finally shifted east. There is now a weakness over the northeast which will allow upper level trough's to get into the area more "fluidly." At the same time, this allows northern stream energy to downstream into the northeast which could call for wetter than normal conditions to get into the northeast by the end of this month. 

The 12z EURO model is in fair agreement of the 12z GFS of this eventual pattern change as evidenced below...

What does this mean? 

1. The heat wave will come to an end Saturday 

2. An MCS may develop Saturday evening into Sunday which could spark severe weather

3. Pattern changes by early next week to average to slightly below average temperatures and potentially wetter than normal conditions. This pattern may persist into early August, until the Bermuda High re-develops again. 

In sum, a break from the heat and humidity is in order. Stay patient and make the best of it for now! 

I'll be back next month with a look at the Hurricane season and when we can expect tropical storms firing up in the Atlantic. 

-Francesco Paparatto