Joestradamus is looking at model guidance that continues to flip flop in all sorts of directions and run to run shifts add an extra challenge to figuring out how the long range winds up looking. Right now we do know that this week will dominated by a trough in the east and a ridge in the rockies. This delivers some nice dry air for the middle and latter part of this week and perhaps even into the start of the weekend.
The trough is broad and keeps the flow southwest over the Atlantic and keeps heat and humidity away at least for a few days. The trough hangs around and just weakens and shears out over time.
Not much wet weather with this kind of set up. At least the last full week of August goes out the way much of the summer has been. Dry!
Now what of down the road? Alot depends on whether the troughing in the east eventually relaxes and disappears. However even a week from now there is still some weak troughing in the east.
Even at 168 it is still there. It is weak but still there. From a tropical storm standpoint the northeast and mid Atlantic will remain protected as long as there are westerly winds aloft (however light) north of 35 N. Warm air takes over in the Plains and Middle Mississippi Valley back through Texas. Troughing comes into the west which gives support to the ridge in the middle. For practical purposes it will be warm but not overly so through next weekend. The weak disturbances in the flow might mean some scattered thunderstorms in the mix in the northeast but not enough to cause any serious problems for next weekend.
Beyond 168 who knows! The Euro has us under a ridge with some sort of tropical system half way between North Carolina and Bermuda. The Gfs maintains weak troughing in the east until 240 hours. The high run to run variability propbably means that beyond the 1 week range models will continue to flip flop from run to run and remain unreliable for any strong conclusions.
So we continue to watch run to run to see how this all finally winds up playing out. With the tropics seemingly active right now unreliable long range trends remain very very difficult to get a grasp on. Speaking of the tropics I want to touch on something that we see on the water vapor imagery that is quite important.
We have marked off on the water vapor imagery two dominate upper lows in the atmosphere in the Atlantic. This is typical in El Nino years and it is very hostile to tropical development. There is a small window south of 15 N and East of 50 where the sheer is minimal and that is why we have seen Hurricane Danny form and the system behind it that looks to be close to becoming a depression based on the loop. Those upper lows need to get out of the way for anything in the tropical Atlantic to hold together. The other option is for something to survive the trip to off the southeast coast of the US where the flow is anticyclonic or high pressure aloft which would be favorable for development. For now those upper lows hold sway over the tropical pattern for this coming week.