ATL: HELENE - Post-Tropical

[ROCK]

The tropical models are running seven07l now.
GDFL
http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation
HWRF
http://moe.met.fsu.edu/cgi-bin/hwrftc2. ... =Animation

GFDL does nothing really with it....the HWRF moves it inland then back out and hugs the coast up towards upper TX coast...

[tolakram]

Live loop, speed it up for full effect.

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=15

Circulation, if that's what I'm seeing, looks extremely close to the coast.

[Houstonia]

Jeff Lindner update:

Visible satellite images and radar data from Mexico indicate the area of disturbed weather in the Bay of Campeche is becoming better organized and a tropical depression is likely forming.

The system is moving toward the WNW at around 10mph and on this track will move inland later today or early tonight. However the ridge to its north and northeast is forecast to weaken and break down on the western edge allowing the system to slow and possibly stall as it nears the coast…this has been what the global forecast models have been showing for days now. The main question is does the center stall offshore or inland. Over the weekend the system should start to drift northward as it becomes influenced by the deep trough along the US east coast and it is possible that the center could move inland tonight and then back offshore over the weekend.

Recon aircraft will be flying this system early this afternoon.

[ROCK]

I agree with Jeff...the GFS has been showing this slightly inland then back out offshore for days now. really close call.

[KWT]

Given how close it is to land it should get inland before it gets the chance to be upgraded, may even be inland by 18-21Z judging by its current progress, which only gives it 3-6hrs or so over water. It seems to be closer to the coast than the models were expecting, which probably in turn reduces the chances of it getting back over water down the line.

[Aric Dunn]

notice the flow over middle texas switching to ssw flow. this system should very soon start to turn more to NNW motion today especially as it gets better organized. the models themselves are showing it getting quite close to brownsville before it comes ashore now.

[Pearl River]

Repost from a couple of pages back of what NOLA said in their AFD this morning:

THE GFS HAS RETURNED TO HAVING A STRONGER TROPICAL LOW
PRESSURE SYSTEM DRIFTING NORTH ALONG THE NORTHEAST MEXICAN COAST
EARLY NEXT WEEK...BUT NEITHER THE OPERATIONAL GFS OR ECMWF BRING
THE SYSTEM AS FAR NORTH AS TEXAS. SEVERAL OF THE GFS ENSEMBLES DO
BRING THE LOW NORTH OR NORTHEAST TOWARDS TEXAS AND LOUISIANA...SO
WILL HAVE TO CONTINUE TO MONITOR THIS SYSTEM.

[Extratropical94]

Given how close it is to land it should get inland before it gets the chance to be upgraded, may even be inland by 18-21Z judging by its current progress, which only gives it 3-6hrs or so over water. It seems to be closer to the coast than the models were expecting, which probably in turn reduces the chances of it getting back over water down the line.

Well I guess the last chance to be upgraded is at 5PM EDT then, depending on how much data the recon aircraft will have gathered until that time.

[ROCK]

Given how close it is to land it should get inland before it gets the chance to be upgraded, may even be inland by 18-21Z judging by its current progress, which only gives it 3-6hrs or so over water. It seems to be closer to the coast than the models were expecting, which probably in turn reduces the chances of it getting back over water down the line.

Well I guess the last chance to be upgraded is at 5PM EDT then, depending on how much data the recon aircraft will have gathered until that time.

will they upgrade to TD7 again or will it be named a different TD? thats something I have been thinking about if it does get upgraded.

[CrazyC83]

Given how close it is to land it should get inland before it gets the chance to be upgraded, may even be inland by 18-21Z judging by its current progress, which only gives it 3-6hrs or so over water. It seems to be closer to the coast than the models were expecting, which probably in turn reduces the chances of it getting back over water down the line.

Well I guess the last chance to be upgraded is at 5PM EDT then, depending on how much data the recon aircraft will have gathered until that time.

will they upgrade to TD7 again or will it be named a different TD? thats something I have been thinking about if it does get upgraded.

Probably TD7 again I would think, or Helene if they find a storm (under the heading 07L.Helene).

[Aric Dunn]

Well although my post a min ago made a good argument... it was however based off the center being a bit farther off the coast. just a did a brief analysis and the center seems to have developed very close to the coast... so the likely hood of any strengthening is low. however it should begin to move more nnw and could easily reform farther off shore if deep convection develops.

[vbhoutex]

Just how interesting is this going to get? I don't like the scenario possibilities, but I hope we Texans end up getting the rains needed without any flooding problems here or in Mexico. This is the latest from Jeff Lindner:

Visible satellite images and radar data from Mexico indicate the area of disturbed weather in the Bay of Campeche is becoming better organized and a tropical depression is likely forming.

The system is moving toward the WNW at around 10mph and on this track will move inland later today or early tonight. However the ridge to its north and northeast is forecast to weaken and break down on the western edge allowing the system to slow and possibly stall as it nears the coast…this has been what the global forecast models have been showing for days now. The main question is does the center stall offshore or inland. Over the weekend the system should start to drift northward as it becomes influenced by the deep trough along the US east coast and it is possible that the center could move inland tonight and then back offshore over the weekend.

Recon aircraft will be flying this system early this afternoon.

[Nikki]

SPECIAL OUTLOOK ISSUED TO UPDATE DISCUSSION OF REMNANTS OF TROPICAL
DEPRESSION SEVEN IN THE EXTREME SOUTHWESTERN GULF OF MEXICO.

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM GORDON...LOCATED OVER THE CENTRAL ATLANTIC OCEAN ABOUT 1100
MILES WEST OF THE AZORES.
SPECIAL TWO:

1. UPDATED...THE REMNANTS OF TROPICAL DEPRESSION SEVEN OVER THE
SOUTHWESTERN GULF OF MEXICO HAVE NOT YET BECOME SUFFICIENTLY
ORGANIZED TO CONSIDER THE SYSTEM A TROPICAL CYCLONE. HOWEVER...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE SYSTEM ARE ALREADY
AFFECTING PORTIONS OF THE EAST COAST OF MEXICO...AND LOCALLY HEAVY
RAINS AND GUSTY WINDS WILL CONTINUE IN THIS AREA DURING THE NEXT
DAY OR SO AS THE SYSTEM MOVES NORTHWESTWARD AT AROUND 10 MPH.
ENVIRONMENTAL CONDITIONS STILL APPEAR CONDUCIVE FOR FORMATION...AND
THIS SYSTEM HAS A HIGH CHANCE...80 PERCENT...OF BECOMING A TROPICAL
CYCLONE AT ANY TIME IN THE NEXT DAY OR SO BEFORE IT REACHES LAND.
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO
INVESTIGATE THIS SYSTEM THIS AFTERNOON...AND A TROPICAL STORM WATCH
OR WARNING WOULD LIKELY BE REQUIRED FOR A PORTION OF THE COAST OF
MEXICO IF ADVISORIES ARE INITIATED.

[Ptarmigan]

I am not surprised that Tropical Depression #7 could reform again. NHC said it would not reform again. I would not be surprised if this ends up being Helene.

[KWT]

I think Aric thats the best chance, reformation, this center will almost certainly get inland before it really gains any major northward component but thats not to stop it from reforming further east again as the old center decsays towards convection.

I would expect though that if recon are there in time to get a decent pass through, its got a very good chance of being re-upgraded.

[Portastorm]

I am not surprised that Tropical Depression #7 could reform again. NHC said it would not reform again. I would not be surprised if this ends up being Helene.

To clarify, I don't think the NHC said TD #7 would never reform again period. That just said it wouldn't reform within the given time frame parameters of their statements (i.e. the system is not expected to reform within the next 48 hours, etc.). In fact, over the last 24 hours the NHC has progressively upped the percentages of this system forming into a tropical cyclone.

[wxman57]

Could well stay very near the coast (sometimes inland, sometimes offshore) alternating between TD/TS for the next 4-5 days as it drifts slowly northward. Final landfall likely south of Brownsville around next Tue-Wed. Could mean some heavy rain for south TX from Sunday through next Thursday.

[wxman57]

I am not surprised that Tropical Depression #7 could reform again. NHC said it would not reform again. I would not be surprised if this ends up being Helene.

To clarify, I don't think the NHC said TD #7 would never reform again period. That just said it wouldn't reform within the given time frame parameters of their statements (i.e. the system is not expected to reform within the next 48 hours, etc.). In fact, over the last 24 hours the NHC has progressively upped the percentages of this system forming into a tropical cyclone.

Remember, the chances of development mentioned in the NHC outlooks are ONLY for the next 48 hrs. What you don't see is that they are internally predicting development chances out to 5 days. I heard earlier this week that the internal thinking was 70% chance of redevelopment in the BoC around days 4-5.

[NDG]

Could well stay very near the coast (sometimes inland, sometimes offshore) alternating between TD/TS for the next 4-5 days as it drifts slowly northward. Final landfall likely south of Brownsville around next Tue-Wed. Could mean some heavy rain for south TX from Sunday through next Thursday.

I agree with you 99%, to add one thing is that I think is that because of the trough's orientation it could throw in the moisture all the way to SE LA.

[Houstonia]

Remember, the chances of development mentioned in the NHC outlooks are ONLY for the next 48 hrs. What you don't see is that they are internally predicting development chances out to 5 days. I heard earlier this week that the internal thinking was 70% chance of redevelopment in the BoC around days 4-5.

this kind of goes in line with what Jeff Lindner says:

Forecast models have come into slightly better agreement on trying to close off some sort of surface low out of a coastal trough along the eastern MX coast late this weekend into early next week. Not sure if they are picking up on the current system, or a trough that will be left behind near the coast. 00Z CMC has come in fairly aggressive showing development off of Brownsville, while the GFS lingers a broad trough/weak surface low along the NE MX coastline for days. Think the current system will move inland, but leave unsettled weather over the western Gulf well into next week and we will have to continue to monitor for any possible development.

Just not sure if it's a continuation of TD7 or not!