Tropical Depression Gordon

[AbsolutZero]

NHC 5-day orange (40%). 18Z GFS and 12Z EC not being kind to New Orleans. EC also stalls the storm over south TX thru 240 hrs.

Note: Feel free to start a new topic on this if needed as I won't be around much next week. 

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Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sat Sep 1 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Florence, located about a couple of hundred miles west of the
Cabo Verde Islands.

1. Cloudiness and showers over the Turks and Caicos Islands and the
southeastern Bahamas have increased a little bit today. This
activity is associated with a tropical wave interacting with an
upper-level trough.  This weather system is expected to spread
westward across the remainder of the Bahamas this weekend, and move
across southern Florida and into the eastern Gulf of Mexico by early
next week.  Surface pressures are not falling at this time, and
development is not anticipated during the next day or two.
Environmental conditions, however, are forecast to become a little
more favorable for a surface low pressure area to form when the
disturbance moves across the Gulf of Mexico during the early to
middle part of next week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...40 percent.

Forecaster Avila

 

[Windspeed]

Not being kind to Houston either. High cape and surface convergence off the GOM with a crawling surface low means flooding rains for coastal LA and E TX.

[hlcater]

Only a matter of time before the social mediarologists start banging the Harvey 2.0 drum. Granted the euro has had a slow moving TC in TX/LA for at least 3 runs now. The 18z GFS now actually develops the wave, leading to increased confidence that at least something forms.

[Windspeed]

Well these are the questions on which I am focusing for each model run the next 3-4 days:

 

1) How long does it take the wave to close off?

2) Does the northerly 400-200mb flow relax versus ESE flow below 500 mb and how quickly does that occur over the eastern GOM while the TC is developing?

3) How north or south is the track near the mouth of the Mississippi River?

4) When does the slow down and crawl W-to-WSW occur?

 

[NavarreDon]

Have my eyes on this little ditty now.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sun Sep 2 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Florence, located several hundred miles west of the Cabo
Verde Islands.

1. Disorganized showers and thunderstorms over the southeastern and
central Bahamas and adjacent Atlantic waters, including the Straits
of Florida, are associated with a tropical wave interacting with an
upper-level trough.  This weather system is expected to move
west-northwestward across the remainder of the Bahamas, southern
Florida, and the Florida Keys during the next day or so and little,
if any, development is expected during that time due to strong
upper-level winds.  However, the current unfavorable upper-level
wind pattern is expected to gradually change and become more
conducive for a tropical depression to form over the eastern and
central Gulf of Mexico by Tuesday or Wednesday.  This disturbance
will spread locally heavy rains across much of the Bahamas, southern
Florida, and the Keys during the next day or two. See products from
your local weather forecast office for more information.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...80 percent.

Forecaster Stewart

[USCAPEWEATHERAF]

1 hour ago, WxWatcher007 said:

Although still disorganized, 91L has been slowly looking better over the last day. This morning there looks to be some good mid level spin and persistent convection. The sooner it develops a closed circulation, the more potential it'll have in the Gulf. 

spin developing in the low levels too, not quite closed yet.  I think a hurricane is possible in the GOM this week.

[yoda]

2 hours ago, USCAPEWEATHERAF said:

spin developing in the low levels too, not quite closed yet.  I think a hurricane is possible in the GOM this week.

Lol no

[Vice-Regent]

5 minutes ago, yoda said:

Lol no

[Windspeed]

This could be anything from a garbage low to a hurricane. Location of genesis and position of track will be critical. For example, if genesis occurs far enough south and a landfall occurs in west LA/E TX, the odds of a favorable upper environment and stronger TC increase. I have noticed that the 0z ECMWF backed off its W to WSW coastal slowdown and crawl however. My original thinking was if that occurred off the coast, a future Gordon would have had serious potential to intensify. Since both major models are pulling this up the Mississippi valley now, I'm much less confident on a hurricane. It's still in question, just not likely in my opinion.

 

 

 

 

 

[yoda]

8 minutes ago, WxWatcher007 said:

We will have PTC 7 at 5pm, meaning TS watches will almost certainly be issued for portions of the northern Gulf coast. 

NHC will initiate advisories at 5 PM EDT on Potential Tropical Cyclone Seven, located between the north-central coast of Cuba and the central Bahamas.

What about S FL?

[Windspeed]

Upper level environment isn't too shabby per 18z GFS. Certainly negligible shear if this was to verify. Decent postioning of anticylone aloft centered over the SE CONUS to support development. But of course the TC itself is lacking in presentation.

[olafminesaw]

4 minutes ago, WxWatcher007 said:

The HWRF is an absolute outlier. Takes PTC 7 from a wave to an 80kt hurricane by hour 51. I have to take this with a grain of salt, but I think it's worth mentioning that PTC 7 is small, and in a space that has a lot of uncertainty (intensity forecasting) there is even more with a small circulation that can ramp up quickly. 

And an unpleasant track for New Orleans to boot.

[Windspeed]

Watching this area closely for genesis tonight. It's the sharpest low-level axis of the wave. Good consolidation of convection could drop pressure enough to do the deed.

[Windspeed]

0z GFS OP does little with this system. Only real valuable data is how it handles the upper level environment. No real changes there from 18z.

[Windspeed]

A little better looking. Noticing some arcing banding fingers on southern inflow. Surface low is probably starting to cutoff. It's weak, but I'd say we're close to this closing.

[MattPetrulli]

45 MPH/1009 MB Tropical Storm Gordon has formed
Special advisory coming at 9 AM will issue tropical storm warnings across southern FL and the keys

[TPAwx]

11AM advisory, NHC adding possibility of low end cane prior to landfall Tuesday evening.

[USCAPEWEATHERAF]

1 hour ago, WxWatcher007 said:

Hurricane watches up for parts of the north central Gulf coast. Gordon is organizing at a solid pace. If it wraps some convection toward the SE that would bode well for even faster intensification. 

Looks like a tight inner core is developing via radar just west of Naples, Florida

[purduewx80]

hurricane-force winds showing up at ~7000' now in that developing eyewall.

[MJV]

In Ave Maria, @ 26.31N 81.45W the rainfall total is 0.18" with winds that didn't reach TD levels here (a gust to 21 mph at a wx underground station 3 miles se of me --- Heller FL) . As of 1pm EDT...we are now observing filtered sunshine. As much as I think the national media means well---I wish they would convey what the facts are --- i.e. what the first RECON flight found so far---no sniff of a surface circulation.  There is a swirl in the 850-500mb layer---per radar and satellite but it's that fast forward motion that is going to disappoint those of the 'first with the worst' mindset in the short term.  Wish we had more rainfall from Tropical Wave Gordon that was LASHING (as the media describes) --- south Florida! 

 

[Windspeed]

Deep convection going up right over that center near Marco Island.

[JakkelWx]

 

Gordon's eye rapidly forming on radar... almost completely tightened south of Marco Island

[USCAPEWEATHERAF]

15 minutes ago, Jakkel138 said:

 

Gordon's eye rapidly forming on radar... almost completely tightened south of Marco Island

Wow

[hawkeye_wx]

I'm thinking the eye-like feature may be mostly aloft.  The rest of the core on radar just doesn't really match up with that kind of intensity, and neither does the satellite presentation.  There's also a buoy near the coast just north of the center and it still says 1014 mb.

[USCAPEWEATHERAF]

Just now, hawkeye_wx said:

I'm thinking the eye-like feature may be mostly aloft.  The rest of the core on radar just doesn't really match up with that kind of intensity.  There's also a buoy near the coast just north of the center and it still says 1014 mb.

I heard the radar captured 95mph winds aloft.

[JakkelWx]

Bumped up to 50/1007 on 2 PM intermediate.

 

 

[MJV]

In Ave Maria, we just reached and past peak intensity with the rain band to the northeast of the circulation center. Picked up another .20 in last 30 minutes but my winds were due easterly at ~13G27kt I can envision the wind radii---if closed is so small. Agree. the surface winds at all the surface sites around sw FL do not support  much needed inflow at the surface ---in the eastern quadrant of the mid-level circulation. It's trying it's best, no doubt.

 

[janetjanet998]

17 minutes ago, hawkeye_wx said:

I'm thinking the eye-like feature may be mostly aloft.  The rest of the core on radar just doesn't really match up with that kind of intensity, and neither does the satellite presentation.  There's also a buoy near the coast just north of the center and it still says 1014 mb.

I was tracking hurricane Humberto in 2007 minute by minute of HOU....this seems to be doing the same thing...expect this wont run into land in 8 hours...the inner core has formed before most of the middle-outer core(..expect the north east side)..lets see if it fills in

 

 

perhaps the friction affect helped that process start quickly

There is often talk of Ocean heat content ..but IMO often that's over hyped....small faster moving systems don't really care how deep the warm water is...

 

[JakkelWx]

Recon finding 1004.8 mb  pressure.

[Windspeed]

Gordon could end up microcane if that 850-700 mb vortex works down this evening and deep convection remains consolidated over it. Very small circulation. Though this is a fast mover and that will definitely make for a much weaker southern circulation, it's not the unfavorable atmospheric environment and high speed steering flow in which Nate was imbedded.