Wave/Upper Low over Western Bahamas

[chaser1]

Convection on the lee side of the westward upper low has really been blowing up. Though unlikely to be a threat given that the wave is entangled with "the rock", i'd still think it warrants keeping an eye on given the type of smallish but potential quick spin-up tropical systems that might be endemic of this season. It would be interesting to note should any falling pressures begin to be noted over the Bahamas or E. Cuba in the next day or two. It wouldn't shock me if something tried to take on some shape either side of the Windward passage or Florida Straits in the next couple of days.

[chaser1]

Just notice the latest 48 hr. RGEM showing some small and weak low approaching S. Florida at 48 hours ( https://www.tropicaltidbits.com/analysi ... s=0&ypos=0 ). Seems a tad quick to me though.

[gatorcane]

CMC going with development now

[chaser1]

CMC going with development now

In any other year i'd say that's the official "all's clear" for S. Florida . This year though...... I'm not so sure. As it is, I have no reason to rely on the GFS or EURO any more than any other model given their wanky behavior. That, and I'm thinking that a number of this year's systems are more mesoscale in nature and perhaps the global's are having a bit more trouble in picking up on the smaller more intricate and fragile development. If this were to really develop though, any real or more significant threat would appear to exist for the Florida Panhandle or points westward.

[northjaxpro]

This area near Hispaniola will need to be monitored closely as we get to late into this weekend and into early next week.

[Steve]

This area near Hispaniola will need to be monitored closely as we get to late into this weekend and into early next week.

That CMC map is valid in 54 hours. That's roughly 2:00pm on Saturday. For anything to happen beyond a little bit of vorticity, the wave can't be right up against the Upper Level Low. The Upper Low has to back off a bit faster so that high pressure (or at least an eddy) can form in the wake giving some uplift potential

[northjaxpro]

This area near Hispaniola will need to be monitored closely as we get to late into this weekend and into early next week.

That CMC map is valid in 54 hours. That's roughly 2:00pm on Saturday. For anything to happen beyond a little bit of vorticity, the wave can't be right up against the Upper Level Low. The Upper Low has to back off a bit faster so that high pressure (or at least an eddy) can form in the wake giving some uplift potential

Good observations Steve. I am wondering though is the TUTT moving out faster than forecasted? That wave interacting with the TUTT is really blowing up convection in a wide area down there this afternoon.

[chaser1]

The other thought I had as well regarding both points made is, if in fact the TUTT might well be helping to create lift via the outflow channel created on the disturbances eastern semicircle? Regardless Steve, I'd have to agree with you insomuch that I'd think we might see some deceleration of the waves forward speed; This would better allow for expanded difluence aloft and a better catalyst for development.

As a side note, a kind of interesting thing to note how the UK brings 92L right up this say "alley-way" toward S. Florida. Course, we'll see if THAT model will have any greater consistency then the GFS or Euro have thus far.

[Steve]

This area near Hispaniola will need to be monitored closely as we get to late into this weekend and into early next week.

That CMC map is valid in 54 hours. That's roughly 2:00pm on Saturday. For anything to happen beyond a little bit of vorticity, the wave can't be right up against the Upper Level Low. The Upper Low has to back off a bit faster so that high pressure (or at least an eddy) can form in the wake giving some uplift potential

Good observations Steve. I am wondering though is the TUTT moving out faster than forecasted? That wave interacting with the TUTT is really blowing up convection in a wide area down there this afternoon.

I can't really tell. Pretty much everything is booking it across the Atlantic as I guess it's still a little before the peak of the season. It looks to me that the ULL and Wave are kind of in tandem. The ULL is munching down on some of the wake of Gert on its west side, while the wave is right up against it on the east which is where the area of enhanced convection is. I'm not sure if they separate, if the wave degenerates or if it just gets absorbed into the ULL as that moves westward. CMC didn't agree and does put a vortex at the tip of FL as the 12z run shows. So maybe?
http://www.ssd.noaa.gov/goes/east/watl/vis-animated.gif

[Steve]

It's probably a good thing that there are reasonable steering currents so that this giant Upper Low isn't just going to sit and spin. I'm not saying it'd ever get to warm core, but it could generate bands of rain on the outskirts. It's also a good thing that most hurricanes don't get this big.
http://www.ssd.noaa.gov/goes/east/gmex/wv-animated.gif

[Frank P]

It's probably a good thing that there are reasonable steering currents so that this giant Upper Low isn't just going to sit and spin. I'm not saying it'd ever get to warm core, but it could generate bands of rain on the outskirts. It's also a good thing that most hurricanes don't get this big.
http://www.ssd.noaa.gov/goes/east/gmex/wv-animated.gif

Looks like that big ole upper low is cranking up the storms in the GULF this am... if it continues off to the WNW it could be a rainy weekend along the NGOM coastal areas... this has been one wet summer for sure... seems like we have been getting hammered with thunderstorms daily.. never seen so much rain before during summer... this is from one of yesterdays big boomers on the beach in Biloxi

[chaser1]

Nice pic of that squall coming in. I hadn't realized just how wide and how nice the beaches actually were there in Biloxi.

[Steve]

Tinypic has been sucking, but if it works (had to go to CTRLQ), this is our first action from the ULL looking South.



What's interesting is there is some action right along the LA/MS Border in association with some of the flow around the ULL interacting with the trough close to the Gulf Coast. One of the globals on Thursday and one on Friday showed a small system off the LA Coast after the passage of the ULL. There is no current model support, but it does look like a piece of the trough is dropping down. It would be probably late Monday before the ULL is out of here completely. Odds < 5%, but it's getting close to the time where you have to watch everything.

[Steve]

Here it is on AVN.

http://www.ssd.noaa.gov/goes/east/gmex/avn-animated.gif

However, because this is the front side of the cyclone, this energy is probably just going to rotate down into the west side. There is still that energy piled up east of Florida on the East side of the ULL. Maybe that migrates over and interacts with a leftover surface trough if anything.

The interaction shows up great on Water Vapor as well. You can see that W/E flow with the small dip about 75 miles inland.
http://www.ssd.noaa.gov/goes/east/gmex/wv-animated.gif

And a wider view which really shows it well.
http://www.ssd.noaa.gov/goes/east/eaus/wv-animated.gif

[LarryWx]

The band of cloudiness/showers associated with this that is currently stretched from S FL
NNE into the Atlantic is progged by model consensus to move NW to near and just inland of the SC coast tomorrow just in time to quite possibly block out much of the eclipse viewing for a good portion of those areas tomorrow afternoon. Let's see what actually happens