ATL: HARVEY - Post-Tropical - Discussion

[cycloneye]

@MJVentrice
Flooding rains possible across Texas over the next 7 days in association to rejuvenation of #Harvey.



 https://twitter.com/MJVentrice/status/899983756987174912

[gatorcane]

Saved loop as sun comes up:

[WeatherGuesser]

I don't see this often:

National Weather Service Paducah KY
716 AM CDT Tue Aug 22 2017

The remnants of Tropical Storm Harvey currently near the Yucatan
Peninsula are expected to push northwest and then intensify before
possibly making landfall somewhere in Texas late this week. The
latest guidance, 00z GFS and 00z ECMWF deterministic models, along
with the GFS and Canadian Ensemble means, are hinting at the
remnants of this system getting drawn up into the Heartland next
week. The consensus was to bring the bulk of the rain from this
system into the area Monday into Tuesday. However, the ECMWF is
slower and waits until the middle of next week. Since this is still
nearly a week out, there is a lot of uncertainty regarding this
latest trend. There remains a wide range of possibilities on where
Harvey`s remnants may end up tracking. Just something to keep an eye
on and monitor as we head closer to that time frame.

[MississippiWx]

Quite a range of solutions possible with Harvey. I believe the strength of the storm once it reorganizes will be determined by how much interaction it has with the upper low to the north and northwest. The upper low looks like it will move far enough away or fill in to allow ideal upper level conditions to take over. Add in the ventilation from the upper trough swinging by to the north and you have almost a perfect upper level outflow setup for Harvey to take advantage of up until landfall.

Not trying to hype the potential storm by any means. I believe we need to see how the guts of the system redevelop while over the Yucatan/BOC first, but some models showing rapid intensification until landfall is not something to overlook. This isn't a 5-7 day forecast of an African wave or wave in the MDR. This is fairly soon that some models are showing this kind of intensification and well within their good skill range. Don't underestimate this scenario.

[NDG]

NDG,close to your position.

12z Best Track:

Location: 19.4°N 89.2°W
Maximum Winds: 25 kt Gusts: N/A
Minimum Central Pressure: 1010 mb
Environmental Pressure: 1013 mb
Radius of Circulation: 120 NM
Radius of Maximum Wind: 90 NM

http://i.imgur.com/HWPRXhG.png

Yeah, I think they are correct, at first I thought it was going to be a little further north as the morning goes the vorticity is indeed near their estimated fix. Perhaps a little more north & west on the circled area.

[Tireman4]

XUS64 KHGX 221226
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
726 AM CDT Tue Aug 22 2017

.AVIATION...
VFR for most of the day today. Any early morning fog will dissipate
by 13Z. Not anticipating a lot of SHRA/TSRA coverage today. VFR
for a majority of the area tonight with increasing SHRA/TSRA coverage
possible tomorrow. 42
&&

.PREV DISCUSSION... /ISSUED 534 AM CDT Tue Aug 22 2017/

DISCUSSION...
Currently, radar imagery shows little shower development over the
far offshore waters, with showers dissipating almost as quickly
as they are forming. Temperatures are in the mid to upper 70s
further inland and in the low 80s along the coast, with dew points
in the low to mid 70s. Clear skies across SE texas will become
partly cloudy shortly after sunrise, with the increase in precip
development with the help of daytime heating.

Temperatures and PoPs for today seem to be right on track. Tuesday`s
forecast should look slightly similar to what we saw Monday, with
the main difference being drier air aloft. This dry air can be
seen in tonight`s 00Z soundings and is also indicated in the GFS
and NAM forecast soundings. The GOES-16 precipitable water imagery
is also picking up on the drier conditions with PWs ranging from
1.4 to 1.7 across the region. With the addition of this drier air
filtering in from aloft with daytime mixing and subsidence holding
tight, expecting overall less coverage today than Monday.
Therefore, isolated to widely scattered coverage should increase
through mid morning forming over the waters and pushing onshore
by mid morning. Most convection should dissipate this evening
shortly after sunset.

A frontal boundary moves into the northern counties within our
area of responsibility late Wednesday afternoon into early
Thursday, bringing with it a band of precip out ahead of the
actual front. This front is not expected to provided a relief from
the heat, though it will lower our high temperatures Thursday by
two to three degrees. Additionally, development will also be
possible along the coast Wednesday morning and into the afternoon
as the seabreeze again moves onshore. The TUTT low that is
currently located over the northern Gulf of Mexico will also
continue to move to the NE, and should help to lower heights and
potentially aid in lift. Therefore, went ahead and increased PoPs
to 30% across SE TX, Wednesday into Thursday to account for these
features.

Where the forecast gets a little tricky is late Thursday through
Sunday. The region of disturbed weather formerly known as tropical
system Harvey, as of 1 AM CT was located SE of the Yucatan
peninsula. This region of disturbed weather is expected to cross
over the Yucatan peninsula, ending up in the Bay of Campeche late
tonight into Wednesday morning. As of now, a lot of uncertainty
lies in how the system will redevelop, if it is able to redevelop,
once reaching the Bay of Campeche.

The latest 00Z model runs including the GFS/ECMWF/NAM/Canadian all
indicate the potential for redevelopment, but where the solutions
diverge is in the overall track of the system once reforming. The
solutions show a fairly large spread in possible movement, but the
overall track of the system has shifted to the north in
comparison to the previous 12Z and 18Z runs. Essentially, the 00Z
runs show potential landfall ranging from Northern Mexico to along
the middle Texas coast. There is still plenty of uncertainty in
how the behavior of this system will pan out, but regardless of
where this system could make landfall if it is able to
reintensify, there is a considerable increase in the amount of
rainfall that could be expected between Thursday through Sunday.
Therefore, increased PoPs across this time frame. Decided to cap
the PoPs at 50% strictly because of the lack of confidence based
on potential track and timing uncertainties with this system. This
also means that the temperatures over these days were also
lowered to below normal to account for the increase in potential
rainfall and cloud cover.

Hathaway

MARINE...
Carrying light to moderate winds and low seas through Wednesday.
There continues to be uncertainty in the forecast beginning on
Thursday as latest models have the remnants of Harvey reorganizing
and moving toward the lower to middle Texas coast. Similar to
last night, have nudged up winds and seas some more with the
highest values now in a Thursday night through Sunday time period.
Mariners are urged to closely monitor the forecast as area
winds/seas could end up a lot stronger/higher. 42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 98 76 99 76 94 / 10 10 30 30 30
Houston (IAH) 95 77 96 77 93 / 30 10 30 30 30
Galveston (GLS) 92 82 91 83 91 / 30 10 30 20 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

Discussion...11
Aviation/Marine...42

[srainhoutx]

Very evident that a NW motion has commenced via visible satellite imagery. Time for NE Mexico/Texas/Louisiana folks to pay real close attention. The rainfall impacts will likely spread well beyond wherever this System finally makes landfall and could be prolific if the slower motion over S Central/SE Texas verifies.

[WeatherGuesser]

If it comes here, that will be the second one this year (can't remember which earlier one) which would be very unusual. Every few years I get one. Can't recall ever getting two in one year.

[ROCK]

Very evident that a NW motion has commenced via visible satellite imagery. Time for NE Mexico/Texas/Louisiana folks to pay real close attention. The rainfall impacts will likely spread well beyond wherever this System finally makes landfall and could be prolific if the slower motion over S Central/SE Texas verifies.

agree with that statement. I just hope we don't get anything more than rain. Flo0ding is horrible but winds on top of that are no fun.

[SoupBone]

If it comes here, that will be the second one this year (can't remember which earlier one) which would be very unusual. Every few years I get one. Can't recall ever getting two in one year.

Where's "here"?

[TheStormExpert]

Anyone have any thoughts on when advisories on Potential Tropical Cyclone Harvey could be initiated? I hear talk about Wednesday but that seems like it would be pushing it.

[Tireman4]

I should know this, but when is recon going in there...after it leaves the Yucatan, I presume?

[RL3AO]

Anyone have any thoughts on when advisories on Potential Tropical Cyclone Harvey could be initiated? I hear talk about Wednesday but that seems like it would be pushing it.

If landfall is 96 hours away, then it's way too soon for watches.

[Thetxhurricanemaster]

I should know this, but when is recon going in there...after it leaves the Yucatan, I presume?

Recon going in late tonight around 10PM central

[FireRat]

Looking at the satellite loop this morning, the system looks very good for being over land. Agreed, we really gotta watch this very closely, especially if it takes off as soon as it hits the GOM.

[hohnywx]

I should know this, but when is recon going in there...after it leaves the Yucatan, I presume?

The Gulfstream flight is scheduled for tonight I believe to help the models and then multiple recon flights are scheduled for tomorrow.

[GalvestonWXGeek]

Anyone have any thoughts on when advisories on Potential Tropical Cyclone Harvey could be initiated? I hear talk about Wednesday but that seems like it would be pushing it.

If landfall is 96 hours away, then it's way too soon for watches.

Are the models predicting a Saturday (8-26) landfall?

[Tireman4]

I should know this, but when is recon going in there...after it leaves the Yucatan, I presume?

Recon going in late tonight around 10PM central

That would make sense..it should be clear of the peninsula by then....

[SoupBone]

I should know this, but when is recon going in there...after it leaves the Yucatan, I presume?

The Gulfstream flight is scheduled for tonight I believe to help the models and then multiple recon flights are scheduled for tomorrow.

I thought I saw someone post last night that recon was scheduled for this afternoon?

[Kazmit]

It's been 9 years since a hurricane landfall in Texas. The last one was a certain storm from 2008...