ATL: ALBERTO - Post-Tropical

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed May 23 2018

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

A broad surface low centered near the coast of northeastern Belize
continues to produce a large area of cloudiness and showers
extending from the northwestern Caribbean Sea across Cuba and into
the Florida Straits. Little development is expected during the
next couple of days due to strong upper-level winds and proximity to
the Yucatan Peninsula. However, environmental conditions are then
forecast to become more conducive for development, and a subtropical
or tropical depression could form this weekend over the eastern or
central Gulf of Mexico. Regardless of development, locally heavy
rainfall is possible across western Cuba and the Cayman Islands
during the next few days, and over much of Florida and the
northern Gulf Coast during the weekend. For more information on the
heavy rain threat, please see products issued by your local weather
office. The next Special Tropical Weather Outlook on this system
will be issued by 800 PM EDT.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...60 percent.

$$
Forecaster Blake

[srainhoutx]

The overnight Ensemble (NCEP/ECMWF/CMC) TC Genesis Probabilities increased to a 90% chance of genesis over the next 48 hours with a 100% chance over the next 120 hours.

[tolakram]

-- posts removed --

Stick to model runs in here. If you have an issue with a post REPORT IT.

[NotSparta]

The latest STWO has stronger language, saying conditions are forecast to be more conductive rather than they may

[chris_fit]

The overnight Ensemble (NCEP/ECMWF/CMC) TC Genesis Probabilities increased to a 90% chance of genesis over the next 48 hours with a 100% chance over the next 120 hours.

Wait, so NCEP/ECMWF/CMC say 90% chance within next 48 hours, and NHC says 0% in their latest TWO? What does the GFS Say?

[Dean4Storms]

Let's just hope the lower end intensities of the overall model forecasts hold true. You don't want strong winds over 50mph with soaked ground.

[drezee]

Last Euro drops over 15 inches of rain over S Alabama. Yuck. Let's hope it doesn't stall.

[drezee]

Agreed Dean...Joe just put out a new public video that says just that:

https://www.weatherbell.com/video/the-d ... e-414?full

[Dean4Storms]

Some 25kt winds to the WNW of the center along the coast of the Yucatan Peninsula. If this is an accurate representation of the surface wind field I see why NHC is going with 60% once this gets in the Gulf with time and lots of 80F SST's.

http://rammb.cira.colostate.edu/products/tc_realtime/image_mpsatwnd.asp?product=mpsatwnd&storm_identifier=AL902018&product_filename=2018AL90_MPSATWND_201805230900

[northjaxpro]

Hello Dean. Once 90L gets a bit farther away from the influences of the Yucatan Peninsula, it should have a better opportunity to try to organize, but shear will keep the system lopsided to the east.

[Ivanhater]

Actually..Looking at the Euro, this has a huge rain shield to the north. North central Gulf coast looks terrible this weekend

https://weather.us/model-charts/euro/mi ... 1500z.html

[Dean4Storms]

:uarrow: Hello Dean. Once 90L gets a bit farther away from the influences of the Yucatan Peninsula, it should have a better opportunity to try to organize, but shear will keep the system lopsided to the east.

Hey northjaxpro.... yea the shear and some relative dry air will be an inhibitor but we have seen highly sheared systems before in the GOM reach 60 to even hurricane strength so I'm keeping a close eye on it. I keep a large Motorhome about a block from the Beach here in Miramar Bch. just east of Destin along with a storage shed and golf cart so if this looks more menacing than currently what most models are forecasting I need time to get over there and secure things. I also have my wife's family coming down this weekend for a visit and they keep asking me about this situation. Right now I'm just telling them lots of rain and maybe some squalls with wind gust possibly to 40-50mph and they are fine with that but anything stronger they need to stay away.

[NDG]

Some 25kt winds to the WNW of the center along the coast of the Yucatan Peninsula. If this is an accurate representation of the surface wind field I see why NHC is going with 60% once this gets in the Gulf with time and lots of 80F SST's.

http://rammb.cira.colostate.edu/products/tc_realtime/image_mpsatwnd.asp?product=mpsatwnd&storm_identifier=AL902018&product_filename=2018AL90_MPSATWND_201805230900

The image is not correct, the surface low/trough appears to be right on the coast this morning. Cancun is now reporting east winds.

[northjaxpro]

Yeah Dean definitely we do not need any wind as trees can be toppled easily with the soil being so satuated across the region.

[psyclone]

WPC now has a QPF bullseye of 7"+ on the northern gulf coast from about Okaloosa county fl to the MS line. it looks like everyone east of about 90 longitude is in for a full scale dump fest per their latest iteration.

[Stormcenter]

Funny how the NHC is still basically splitting the difference somewhat between the GFS and EURO with their anticipated track of 90L even though
most other models don't see anything similar to what the GFS keeps on spitting out. That being said, I still have seriously doubts about the eventual
strength and track of 90L. IMO

[AdamFirst]

NWS Melbourne disco

Late week...Developing low pressure is forecast to slowly emerge
over the southern Gulf from the Yucatan area late this week. Med
range guidance is muddled attm with movements and degree of
central development. GFS wl be discounted attm due to disparity in
its ensemble members, apparent feedback, and deviation from
EC/CMC as noted by recent WPC hemispheric discussion.

Regardless of discrete development, the regional forecast regime
with deep tropical moisture ushering Nwd favors numerous showers
and occasional storms daily late this week and through the weekend
with this most favored wet season forecast regime continuing over
already rain soaked grounds in many places. A Flood Watch will be
likely for portions of east central FL by late this week.

[Shell Mound]

Based on available data, I think that 90L may well follow a path similar to Allison's (1995). The most-at-risk area appears to extend from Destin to St. Marks, FL. Of course, most of the effects will extend well to the east of the disorganised low, meaning copious rainfall over peninsular FL, with the heaviest totals likely concentrated along the west coast from the lower FL Keys to the Big Bend (Nature Coast). I should note that many of the GEFS members show at least a moderate (sub-)tropical storm with pressures of about 995-1000 mb before "landfall" in the FL Panhandle. The 00Z EPS mean has also become more aggressive with the intensity compared to previous runs. Considering the sprawling size of any potential cyclone, that would likely mean peak sustained winds of up to 50 knots well to the east of the centre. Note that the pressure gradient on the flank of the subtropical high will likely enhance the strongest gusts on the eastern side of the circulation, as well as generate uplift to sustain locally prolific rainfall. As of now, I am starting to become more bullish about the prospects for development in the eastern Gulf of Mexico, and suggest that residents in FL and GA get ready for an early-season threat consisting of strong winds and heavy rainfall. I think that some professional mets (wxman57 and AJC3) have provided ample argumentation in support of the eastward model solution(s), and I think that the Hurricane Center's preliminary "cone" aptly captures where this probable cyclone is likely to head, at least generally. Notably, models have trended toward better co-location of the low-level circulation and cutoff low, and also have started to indicate a negative tilt to the cutoff low, likely contributing to stronger divergence and hence a stronger cyclone. However, this also means that a subtropical or hybrid-type system is more likely than a purely tropical cyclone, at least in my view.

[Shell Mound]

I wouldn't preclude a stronger-than-expected system at this time. Models are trending toward a more vertically stacked system, with the low-level and mid-to-upper-level circulations aligning, meaning co-location of the system with the cutoff low. A number of GEFS and EPS members (plus UKMET) suggest a storm of at least moderate intensity, with a pressure ranging from the mid-990s to the very low 1000s (mb). I'm thinking that the EPS will shift eastward toward the FL Panhandle, while the GEFS will no longer favour a solution to eastward of St. Marks, FL. In short, I would expect a convergence over the FL Panhandle.

[stormlover2013]

all depends where the center forms, that makes a world of difference..........all I know if either GFS or Euro will get on board soon with one another......Euro doesn't lose to often but it can lose sometimes so lets see how this plays out......