Due to some fundamental shifts in the weather pattern, we are seeing a big warm up take hold of the Central and eastern US , namely a trough/upper level low that has set shop right along the west coast, this is leading to more of a zonal flow across the country, meanwhile the pesky Atlantic ridge is located just off the SE coast trying to send up a southwesterly flow so things will get pretty hot and humid over the next 3 days or so as a broad ridge develops over the Midwest/Northeast but there’s also other things going on that will make this warm up much shorter than originally expected as well
For today and tomorrow generally expect sunshine with above average temperatures, mostly in the mid to upper 80s for most , could see an isolated 90 degree reading in urban locations especially tomorrow , lower to mid 80s in NE PA ,humidity levels tomorrow expect heat indices to be in the low to mid 90s nothing extraordinary considering its August but its something we havent seen in nearly a month or so , so it may be a bit of a shock to the system as the last stretch of truly hot weather we had was the 3rd week in July , low temperatures generally in the mid 60s to low 70s , upper 50s to low 60s NE PA
On Thursday we will have a disturbance approach from the southwest with some scattered showers/storms along with a cold front dropping from the northwest, so with more in the way of clouds and storminess highs on Thursday look like generally lower to mid 80s but very high humidity will make it feel worse , the chance for scattered storms will continue into Thursday night before the front clears through Friday , this front doesent have high severe potential but does have the heavy downpour/flash flootd threat for areas that get under these scattered storms.
Originally this warm up was expected to be a pretty long-lasting thing but we have seen an interesting shift in the MJO which will make this a short-lived warm up for the northeast
We are going from neutral phase to phases 8-1 which means convection is trying to fire around the dateline, this will for one lead to a quickly re-developing trough near the Aleutians and 2 prevent this ridge from getting too strong , this shift will lead to a cold front dropping south over the northeast and force the heart of the ridge to remain over the Northern Plains , and will suppress the western Atlantic ridge which will lead to a trough taking hold again and a return to near average to below average temperatures starting Friday and lasting through next week , generally mid 70s to low 80s for highs are expected and lows returning to the 50s for many during this period
It does look like quite a strong ridge is going to build over the northern Plains so over the next few weeks we may be dealing with a bit of a battle , I do think we will see this ridge retrograde west ward though , leaving our area in overalll a northwesterly flow with average to below average temps being dominant