August 2020:

[Andrew]

So Andrew ur a pro what is ur gut telling u? Sometimes u gotta go with the gut

I'm definitely more concerned for Laura than TD 14. I think a Central gulf coast landfall for Laura looks likely but there is so much uncertainty right now I don't put a ton of stock into it. I also think Laura has a decent chance to intensify in the gulf too.

[Scott747]

Models are having major difficulties with how the two storms will interact with each other

How much though? I joked earlier about both systems being close enough for a fujiwhara effect but that's almost impossible in the gulf.

They both seem far enough away to not be influenced by each other. In fact I can see how Marco could miss any weakness from the current trof as it exits and Laura continues w as long as it stays far enough s as it rounds the building H.

Marco washes out and creates no 'weakness' for Laura to feel....

[Cpv17]

Models are having major difficulties with how the two storms will interact with each other

How much though? I joked earlier about both systems being close enough for a fujiwhara effect but that's almost impossible in the gulf.

They both seem far enough away to not be influenced by each other. In fact I can see how Marco could miss any weakness from the current trof as it exits and Laura continues w as long as it stays far enough s as it rounds the building H.

Marco washes out and creates no 'weakness' for Laura to feel....

Isn’t there a chance too that the high to our west connects with the one to our east?

[Scott747]

Models are having major difficulties with how the two storms will interact with each other

How much though? I joked earlier about both systems being close enough for a fujiwhara effect but that's almost impossible in the gulf.

They both seem far enough away to not be influenced by each other. In fact I can see how Marco could miss any weakness from the current trof as it exits and Laura continues w as long as it stays far enough s as it rounds the building H.

Marco washes out and creates no 'weakness' for Laura to feel....

Isn’t there a chance too that the high to our west connects with the one to our east?

So far I've seen no evidence of an interconnecting H. Laura continues w as the subtropical ridge builds across the Bahamas.

Laura eventually feels a weakness created by Marco or it rounds the H. Depending on how far that H extends, or any other incoming trof it will keep moving w .

[sau27]

00z Euro ensemble very similar to 18z. Laura moves west across the gulf towards Texas. Members from Mexico to SW LA.

[Stormlover2020]

Can u send image

[Scott747]

Based on the ensembles there should be another shift to the w that would put parts of the upper Texas coast firmly in the cone.

Again I'm not sure if they will shift that far w.

[Scott747]

Waiting for the Laura disco but after seeing the Marco one. The building ridge is a beast.

[Andrew]

Based on the ensembles there should be another shift to the w that would put parts of the upper Texas coast firmly in the cone.

Again I'm not sure if they will shift that far w.

Not that far but they did shift to the west.

[Scott747]

6z GFS brings a rapidly deepening system towards the mid Texas coast next Thursday.

[Stormlover2020]

Looks about like Freeport!!!

[Kingwood36]

Again...getting bad juju here in freeport...move it somewhere else

[srainhoutx]

RECON flying Marco suggests it's strengthening quickly and has a 6 mile wide circular center via the earlier vortex message. Getting another ceter fix now. Pressure appears to be falling.

[tireman4]

Meanwhile, back at home... for the short and long term...

000
FXUS64 KHGX 220954
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
454 AM CDT Sat Aug 22 2020

.SHORT TERM [Through Sunday]...
Showers/isolated thunderstorms will be moving into our NW counties
through the early morning hours. This activity (courtesy of an em-
bedded shortwave in the N/NW flow aloft) is expected to continue to
move toward the coast into the rest of the morning. However, we`ll
likely see scattered activity re-develop across much of the south-
ern 2/3rds of the FA for this afternoon. Weaker ridging along with
greater instability via the upper trof axis and the shortwave over
the region will help with development along the seabreeze (and any
other outflow or other boundaries). Activity should decrease by the
evening hours. Models are indicating perhaps another shortwave for
tonight, but much weaker. So will probably keep things drier over-
night across SE TX. Tomorrow`s rain chances could be more isolated
to widely scattered during the afternoon. Otherwise, have kept the
high temperature grids on the warmer side of MOS (especially given
the trends of late). 41

&&

.LONG TERM [Sunday Night Through Saturday]...
Sunday night, we should begin seeing the axis of deeper moisture
associated with TS Marco arrive in upper Texas coastal waters with
increasing precip coverage in the Gulf...eventually spreading to
maybe the Highway 59/I-69 corridor later in the day Monday with
heating. This, possibly followed by a brief lull in the action
Monday evening.

Based on the latest NHC fcst, Marco should be situated roughly 90
miles off the Tx/La coast around midnight late Monday night.
Anticipate an increase in winds and additional bands of precip
moving inland thru the day Tue and Tue night as the storm take a
turn to the wnw and potentially makes landfall somewhere between
Galveston and Matagorda Bays.

In regards to Marco:
Rainfall:
- Considerable uncertainty, though highest totals tend to be along
and e (or ne in this case) of the center. In general, locations
southeast of Highway 59-I-16 can probably expect and average of
1-3" by midweek (highest near the coast). However, one always
needs to keep in mind rain rates and training bands in tropical
situations for localized much higher totals. With elevated tides
expected, effective drainage may also be impacted along the
coast.

Winds:
- Though Marco may intensify to near hurricane strength over the
open Gulf, it is expected to encounter some unfavorable upper
level winds/shear as it approaches Texas and very could well
weaken. The current fcst brings it in as tropical storm. At
this time, the most likely arrival of TS force winds will be
Monday night into Tuesday morning.

Surge/Tides:
- To early to say and highly dependent on specific details in
which there is considerable uncertainty (track & angle of
approach, intensity, etc). Given the data and fcst we currently
have, it appears to be a good setup for water to pile up north
and east of its track. Locations generally east of Sargent
appear to have the higher risk of coastal flooding possibly
beginning around times of high tide Monday afternoon or night.

Tornadoes:
- Typical more favorable locations are in the ne quadrant, but
it`s way too early to say the overall risk in this case.

Seas/marine:
- Benign conditions into Sunday.
- Beginning arrival of longer period swell: Monday
- Seas building to 6+ feet: late Monday
- Increased water levels & high risk of rip currents: late Monday
- Peak seas: 15-20 ft offshore Tue.
- Arrival of TS strength winds: Monday night although intermittent
gusts to 34kt possible before that in any out precip bands.


Unfortunately we`ll also need to be keeping an eye on what is
currently TS Laura further to the east as it is fcst to intensify
and also move into the Gulf. Though indications are it may impact
areas to our east Wed-Thu, there is a non-zero threat locally.

In summary, two potential tropical systems make for a very low
confidence forecast package. There are too many "what ifs" to go
thru, but know the fcst and impacts are subject to substantial
changes in the coming days - both on the positive side or
negative side. 47

&&

.AVIATION [12Z TAF Issuance]...
No major changes from previous as activity from a shortwave moving
into the western half of the CWA remains the initial focus for iso-
lated to scattered activity this morning. As this feature moves to
the coast late this morning, we`ll likely be transitioning into an
active afternoon for the southern half of the CWA. Will keep VCSH/
VCTS mentions in for sites CXO southward through the early evening
hours. Models are indicating perhaps another shortwave moving into
the area tonight, but much weaker. As such, will probably keep the
TAFs dry for the overnight period. 41

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 98 73 97 73 96 / 30 10 0 0 10
Houston (IAH) 97 77 97 76 93 / 40 10 20 10 30
Galveston (GLS) 94 81 93 80 90 / 20 10 20 40 60

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.

&&

$$

[Cromagnum]

Looks like Marco is gonna prime the engine for Laura and clesr out the dry air for her.

[Kingwood36]

I'm hearing talk on s2k that he is going north to LA now

[cperk]

I'm hearing talk on s2k that he is going north to LA now

What does the NHC say that's who I'm listening too.

[Cromagnum]

I dont understand the misleading information that spacecityweather is putting out.

https://spacecityweather.com/marco-laur ... next-week/

Because a stronger storm might have more impetus to barrel into building high pressure over the southeastern United States, whereas a weaker one would be more steerable to the west

Thats backwards. Stronger storms tend to feel weaknesses around ridges of high pressure more than weak ones. Storms don't barrel towards high pressure systems. They go around. It depends how how far west that east coast high pressure field builds towards the west.

[jasons2k]

Re: Marco -- tracks that bend like that make me nervous. A small change in trajectory could significantly change the landfall location.

[Kingwood36]

With #Marco getting stronger (and thus taller/deeper), expect rightward shifts in the forecast track, since steering currents are less westward at higher altitudes.This increases risk of impacts to LA/MS/AL on Monday.

So they are expecting it to shift towards la