Area of disturbed weather in NW Gulf of Mexico (Is Invest 90L)

[Steve]

I think the ICON is going to be a winner here, likely going to be a rare case where one model sees a system and the others dont, id probably put development chances up to 40-50% now, its definitely starting to look better

The new king of the NW Gulf/Phase 4? It remains to be seen. It showed the spin last Saturday for today and there is one albeit not as pronounced. It lingers the spin and drives it down to the bay of Campeche instead of lifting it out. Whether it’s right or not being able to reconcile possible 2 storms we have to see. CMC lifts it out. GFS is now picking it up but looks to merge the almost islands wave and comes back up to SE Texas a little stronger but not anything crazy. Most of the MJO models have us in phases 4 and 5 the next several days. Some go back into the circle. So it’s more of a watch and see scenario. I didn’t think it was going to be anything strong and ICON did have most of the rain offshore.

[cycloneye]

Northwestern Gulf of Mexico:
A broad area of low pressure just offshore of the upper Texas coast
continues to produce some disorganized shower and thunderstorm
activity near the coasts of Texas and Louisiana and over the
adjacent waters of the northwestern Gulf. This system is expected to
meander near the coast for the next couple of days, and some slow
development is possible if it remains offshore. By Tuesday, the
system is forecast to move inland, and further development is not
expected. Regardless, heavy rains could cause some flash flooding
across portions of coastal Louisiana and the upper Texas coast
during the next couple of days.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

[Frank P]

Watching, just checked the buoys in the GOM and no falling pressure right from the platforms or ships report, most are either steady with some rising. Not much is going to happen until the pressure start dropping.
Lowest pressure appears to be on the Corpus Christi TX coast 29.85 and Buoy 42002 about 200 miles east of Brownville 29.85mb
Wind Direction (WDIR): W
Wind Speed Wind Speed (WSPD): 11.7 kts
Wind Gust Wind Gust (GST): 13.6 kts
Wind Speed at 10 Meters Wind Speed at 10 meters (WSPD10M): 11.7 kts
Wind Speed at 20 Meters Wind Speed at 20 meters (WSPD20M): 13.6 kts

[tropicwatch]

Pressures are beginning to fall.

[Frank P]

Pressures are beginning to fall.

Yes indeed they are now.. lowest I could find out in the GOM was Buoy 42002 @29.83mb and several near the CC TX area at 29.83, and a 29.82mb from a ship report off the coast of TX near CC. The little LLC off the Tx coast is pretty weak and far removed from any convection, unless another LLC develops near the convection in the central GOM or some convection starts to develop around that weak LLC off the TX coast not much is going to happen with this system.

[tropicwatch]

Pressures are beginning to fall.

Yes indeed they are now.. lowest I could find out in the GOM was Buoy 42002 @29.83mb and several near the CC TX area at 29.83, and a 29.82mb from a ship report off the coast of TX near CC. The little LLC off the Tx coast is pretty weak and far removed from any convection, unless another LLC develops near the convection in the central GOM or some convection starts to develop around that weak LLC off the TX coast not much is going to happen with this system.

The 10m wind field rotation appears to be closer to Buoy 42002 then the Texas coast.

[REDHurricane]

Rotation appears to be slowly shifting towards the bulk of the convection south of Louisiana:

https://tropic.ssec.wisc.edu/real-time/ ... anim=html5

[Horn1991]

Rotation appears to be slowly shifting towards the bulk of the convection south of Louisiana:

https://tropic.ssec.wisc.edu/real-time/ ... anim=html5

Yep

[Teban54]

Dry air won't be an inhibiting factor, unlike earlier in the season when Debby was here.

[Hammy]

There's still way too much shear (an issue we've seen in the Gulf for weeks now)

The NAM isn't even showing development, and until it does this is DOA

[Frank P]

The IR sat loops looks more impressive than the vis sat loop, the entire system hints of perhaps a southward drift? But the bulk of the deepest convection is on the south side of the system in the central GOM att. I think 10% is reasonable.

[Stratton23]

Hammy the NAM is utter garbage with tropical development, its really only useful for winter, temperature and that sort of stuff

[TomballEd]

I think this has a better chance of becoming a named storm than the AOI approaching the Caribbean. Limited space to work with, but visible satellite showing spin/vorticity, CIMSS analysis sees it, MIMIC-TPW starting to get that first hint of an interesting look as the 40% mandarin looks less organized on satellite and TPC loops, shear isn't horrible. Ensemble members that do support this not showing much below 1010 mb lows, but as is is much closer to home, now of greater interest that the system soon to enter the Caribbean.

[TomballEd]

There's still way too much shear (an issue we've seen in the Gulf for weeks now)

The NAM isn't even showing development, and until it does this is DOA

The shear goes from very hostile to fairly favorable in a tight gradient, this may get far enough S of the strong winds that they promote divergence and outflow aloft, while the center develops until much less severe shear. I'm not saying odds are high, but between odds of development and proximity to the USA, I'm now paying more attention to this.

[Teban54]

The IR sat loops looks more impressive than the vis sat loop, the entire system hints of perhaps a southward drift? But the bulk of the deepest convection is on the south side of the system in the central GOM att. I think 10% is reasonable.

The impression of a "southward drift" could also just be a result of shear pushing the convection to the south, though.

[Hammy]

Hammy the NAM is utter garbage with tropical development, its really only useful for winter, temperature and that sort of stuff

This is very true, when we're talking the track, because it overdevelops storms--but it's extremely useful in knowing when something is (or rather, isn't) going to develop.

I've used and familiarized myself with it for over a decade now, and it's ALWAYS, without fail, picked up these close to home storms well before any of the models do--it has spun up things that don't form, but not once has it actually missed a storm--if something's going to form in the Gulf, it's always the first to show it.

Given how hypersensitive this model is, if even it isn't showing development, then there isn't likely going to be any, the same way the UKMET is a near-certainty when it actually does show development (given it has the opposite issue of frequently missing storms)

[Frank P]

Add this to the equation as well, the vort in the central GOM is stronger than the AOI in the Atlantic

[Frank P]

The IR sat loops looks more impressive than the vis sat loop, the entire system hints of perhaps a southward drift? But the bulk of the deepest convection is on the south side of the system in the central GOM att. I think 10% is reasonable.

The impression of a "southward drift" could also just be a result of shear pushing the convection to the south, though.

Yeah I thought that too but the vort is just about near the center of the GOM… which surprises me as no model even came close to picking that up at that location, but point taken.

[Ubuntwo]

The IR sat loops looks more impressive than the vis sat loop, the entire system hints of perhaps a southward drift? But the bulk of the deepest convection is on the south side of the system in the central GOM att. I think 10% is reasonable.

The impression of a "southward drift" could also just be a result of shear pushing the convection to the south, though.

Yeah I thought that too but the vort is just about near the center of the GOM… which surprises me as no model even came close to picking that up at that location, but point taken.

That is the 500 mb vorticity, best colocated with the deep convection. The low level swirl near the Texas coast comes up at 850 mb:


Notice the heavy tilt with height, that's the main reason this system is not developing right now.

[Teban54]

Here's the 3km NAM run for clarification purposes. Its current depictions are:

• The convection we're seeing right now dies in a couple hours. This may imply they're partially shear-induced, even though associated with a mid-level vortex (as Frank mentioned above).
• The current low-level vort just offshore Texas drifts SW towards Corpus Christi during the next 36 hours or so.
• However, during the same time frame, the mid-level vort that's currently in central Gulf also gets better defined on its own, while remaining largely stationary. Another low-level vort shows up underneath it in the next 10 hours, but gets pushed to the W much faster than mid-level.
• Beyond 36 hrs, the COC that's now a bit west of Corpus Christi does try to develop a mid-level rotation, but it's too late as the system is already inland.