Changes in the Pacific are leading to big changes over the weather pattern over North America. It took several strong cold fronts to do it but at last the extreme heat east of the Rockies is on the way out if not already gone in many places! A very strong cold front with a polar air mass behind it is dropping south and this will be a big piece to the continuation of the summer pattern break down.
As we can see the heat is now suppressed to the interior Southeast US through the west coast. Cool Canadian air is dropping south which will suppress the heat even more as a strong polar cold front drops all the way to the gulf coast. while the heat ridge continues to crawl west and situate over the western US . We see areas like the Mississippi river valley to the upper plains which have been under the grip of a heat ridge since early June and brutal heat along with a historic drought, are finally getting relief
Ahead of this polar air mass is a line of showers and thunderstorms as a cool dry Canadian air mass clashes with hot humid tropical air mass, this line of showers and storms will move east and impact the area late tomorrow afternoon and early evening in western sections like east PA and tomorrow night over eastern sections like NJ, NYC and Long Island, heavy rain will a main threat and flash flooding as many areas have seen a deluge of rain lately, especially SE NJ through Long Island where as much as 5 inches fell between Tuesday and Wednesday.
Some strong storms may be imbedded, hail will be a threat with cold dry air aloft, strong winds and vivid lightning. Timing isn’t great for severe weather but there will be a lot of heat and humidity to work with tomorrow and instability will be able to reach high levels and last into the night so an isolated severe storm will be possible.
After a stretch of fairly nice weather early this week, we have one last hot humid day to deal with which will be tomorrow with sunny skies and highs in the mid 80s to low 90s, I suspect this will be the last 90 degree day for who ever does hit 90, once the cold front comes through you can say bye to the bad heat and humidity for quite some time.
This is late tomorow afternoon, the line will drop SE through the night into early Saturday morning
Training storms will be possible again as the front will slow down moving through the area, some localized areas will see a lot of rainfall.
The front will come through all areas early Saturday morning which will lead to rapidly decreasing humidity and a cooler air mass crashing into the region, highs Saturday , Sunday and through next week will range from the mid 70s to low 80s, with dry conditions, low humidity. Lows will be in the mid 50s interior like NE PA to lower 60s along the immediate coast, which is slightly below average for this time of year
By Sunday through early next week we see a nice NW flow out of Canada leading to very comfortable conditions
As we head into late week the pattern remains the same with a ridge in the west and a nice trough east ogf the Rockies
And finally heading longer range into next weekend not much changes as troughs drop out of Canada and keep a nice ad comfortable regime over the eastern US. head of these cold fronts and troughs brief bouts of humidity will take hold along with chances of showers and thunderstorms, bu overall a much different pattern than we have seen the last 2 months is clearly taking hold, right on cue with my forecast of an early break down of the summer pattern around mid August!
All I am going to say is if El Nino and other factors stay the same and can keep ths pattern in place through the winter months (this pattern is typical of El Nino), we will have a MUCH DIFFERENT and OPPOSITE result this winter than we did last year.