cieldumort
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Above: W Gulf Trof 9-16-19 1656z. Base image credit: Weathernerds.org
A very persistent surface trof associated with a west to west-southwestward tracking upper-level low is now in a much more favorable environment for TC genesis, with the one exception being lack of time left over water before it moves in over southeast Texas.
While not the same system, this trof and its associated ULL are both parts of the ingredients that helped produce TD NINE (now Hurricane Humberto) a few days ago near the Bahamas. They have since continued west and will very slowly move inland, with the ULL tracking further south into NE Mexico/S TX, and with the impressive surface feature tracking into southeast Texas and eventually into much of the rest of the eastern parts of the state. This slow movement together with high TPW values will result in areas of high to very high rainfall totals and likely flooding, possibly severe, into this week.
NHC odds are at a low 10% for TC genesis, but this is one of those disturbances that will have impacts very much like a wet, slow moving TD, regardless of classification. This system is not yet Invest tagged, but soon may be (probably 98L), and 10% genesis odds from could be conservative. There is a nearly 100% chance of TD-like impacts over portions of the Lone Star state that are notoriously susceptible to flooding (I-35 hill country and east from there into the Houston metro and piney woods of NE Texas).
The W Gulf disturbance has just been Invest tagged 98L, and the title has been updated accordingly.
Edited by MikeC (Tue Sep 17 2019 02:07 PM)
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cieldumort
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Above: 5-Day Quantitative Precipitation Forecast from WPC issued 0852z 09-16-19
From WPCQuote:
Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
1156 AM EDT Mon Sep 16 2019
Valid 12Z Thu Sep 19 2019 - 12Z Mon Sep 23 2019
...Gulf of Mexico disturbance offers a Texas heavy rainfall threat...
...Weather Highlights/Threats...
A slow moving disturbance will have moved into east TX by Wednesday night. This system offers a significant threat of locally excessive rainfall dependent on track. The current track brings it north up east TX where WPC is focused. As pooled tropical moisture lifts farther inland into east-central U.S. convection later week into the weekend in advance of an approaching surface front, especially over the east-central Plains and Mid-MS Valley.
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cieldumort
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Above: (Model) 5 day Accumulated Total Precipitation Forecast. NOT an official forecast
Five day rainfall totals forecast by today's 12 run of the ( Image credit Weather.us ) is a good indication of the potential this disturbance has to produce very serious flooding in eastern Texas.
This is only one model, but a very good one. As always *use with caution* It is possible that this swath of 8" to 30" totals does not occur at all, or sets up many miles to the west or east from where this one run suggests.
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Fully vaccinated as of May 2021
(Moderna x2)
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cieldumort
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It looks likely that 98L responded favorably (for development) to a large supercell that formed within its broad circulation overnight just east of the Corpus Christi area, and the process of undergoing TCG is underway. So long as proto-TC 98L remains at least mostly over water, odds appear to favor formation of a TD at any time now.
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Fully vaccinated as of May 2021
(Moderna x2)
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cieldumort
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Fully vaccinated as of May 2021
(Moderna x2)
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Psyber
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Okay, folks, this is probably what is the most serious threat to the continental USA at this point.
Invest 98L is essentially sitting in place, gathering strength and I see it possibly becoming a TD and maybe even a TS before it starts to do one of those...sorry to bring him up but it could do a very slow dump of rain like Hurricane Harvey over places north of and south of Galveston as it moves inland over Houston and so on. Very very slow movement of the storm over the coast into Texas before slowly going north and dumping epic proportions of rain.
This is NOT weather you should be ignoring. The UK met which seems to be one of the best models this year see's this storm as becoming a weak wind but gigantic rain type storm with a decent amount of probability.
People who remember Harvey (I hope all Texans do) should know that this storm could drop massive amounts of rain to the point of extreme flooding. Certainly 10 inches and maybe up to FEET of rain is possible depending on how long it sits becoming stronger and stronger, filled with more and more water over the Gulf to the west of Texas. It's slated to slowly move west before being pushed north within a couple of days or so. Everywhere it goes, it's going to be going over that land very slowly and dropping A LOT of rain. 
This is an extremely short warning type storm because the Gulf SST's are so warm, they're making what was a fairly disorganized system, organized. If you're in those parts of Texas and north of Houston further inland, please pay attention to what this storm does.
UPDATE
There you go. Just as I was doing this at 12:55, at 13:00 has just upgraded the Invest to TD Eleven and given it a forecast track. They're warning a foot to fifteen inches of rain could be dropped however it all depends on how fast the storm moves. The UK Met has it going slower and as a result dropping more rain in certain areas.
Edited by Psyber (Tue Sep 17 2019 01:22 PM)
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MikeC
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It's Imelda now with a special update. Graphics on left will probably remain out of date until 5pm ish.
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cieldumort
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Imelda will likely be retired. Proof, yet again, that TCs do not require a Saffir-Simpson number associated with them to cause horrific devastation.
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