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Tropical Hurricane Isaias

Gfs and euro are lockstep with strength mostly. Main difference is euro takes the very weak wave over Hispaniola and completely shreds it
The reflection of 92L in the gulf on the euro is similar to what it depicted for Hanna several days out and that ended up being a hurricane. Gigantic waves like this aren’t going to just roll over and die after hitting Hispaniola.
 
The reflection of 92L in the gulf on the euro is similar to what it depicted for Hanna several days out and that ended up being a hurricane. Gigantic waves like this aren’t going to just roll over and die after hitting Hispaniola.
What is your current prediction for how this unfolds? Are you favoring a strengthening system in the Bahamas by Saturday?
 
This could well not develop but I'd keep in mind that the Euro has also been riding the struggle bus with tropical development along with other models.

Edit: So, I'm not sure how much we can rely on globals.
 
Not to stir the pot, but the 12z GEPS (CMC Ensembles) took a step in the wrong direction.92L_geps_latest.png
 
18z GFS a bit concerning. Holds together and gets to the Bahamas. Has a weak system sitting right off of the Florida coast
Not really, that’s only because the further towards the surface you get, the less sheared it will be. If you look at the z500 vort, you notice there is nothing left, due to shear that is usually much higher up.
Here’s 500mb level
955E9EFF-6F6E-41E0-A5F5-7C2D801EF993.png
here’s 850mb
0829FB47-5042-459F-8E6A-3716E53BB2BA.png
 
92L looks to be getting its act together at the moment per water vapor and IR. Moisture is wrapping around the system from the NE, and convection is building around an area where I think the COC will eventually formulate.

I am also worried about the Navgem and GFS track for 92L due to the synoptic pieces on the table, and the potential for the Bermuda high to extend into the Eastern Gulf as it did this week. I don't trust that the trough will deepen as much as some of the models are indicating given that I've noticed runs over the past 10 days have been too aggressive with these troughs. Then there's the issue of COC location, storm speed, and timing of troughs. In regards to the former, the GFS focused on that spin on the SW end of the convection around 11N, 52W, but based on the visible frames below, I think this area and another LLC circled in red are now being dominated by the broad circulation in purple. This area looks to be under the upper level anticyclone, and the two other areas are being sheared. I envision a relocation further north.
Visible.gif
 
Not really, that’s only because the further towards the surface you get, the less sheared it will be. If you look at the z500 vort, you notice there is nothing left, due to shear that is usually much higher up.
Here’s 500mb level
View attachment 45211
here’s 850mb
View attachment 45212

I don't exactly trust the guidance at the 500Mb level, particularly after Hanna. I saw the same broad appearance at the 500Mb level, while the 850Mb level was showing a compact ball. The area the GFS is focusing on as the COC is actually under 20 knots of shear, and you can see it on satellite. The GFS also doesn't have a good handle on the anticyclone, which is displaced further north and east around the area of spin and new convection I pointed out in my last point. I honestly wouldn't trust the GFS model with anything right now, except for the possibility that the storm could track towards Florida and Gulf. I wouldn't put my money on any solution.
 
000
ABNT20 KNHC 272314
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Mon Jul 27 2020

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

Shower activity associated with a low pressure area located about
850 miles east of the Windward Islands has again become a little
better organized, however the low's circulation remains broad
without a well-defined center of circulation
. Environmental
conditions are expected to become somewhat more conducive for
development, and a tropical depression or tropical storm is likely
to form during the next couple of days while the system moves
west-northwestward at 15 to 20 mph and approaches the Leeward
Islands. Regardless of development, locally heavy rains and gusty
winds are likely across portions of the Leeward Islands on Wednesday
and will spread westward to the Virgin Islands and Puerto Rico
Wednesday night and Thursday. Interests on these islands should
continue to monitor the progress of this system, and tropical storm
watches or warnings could be required for portions of the area on
Tuesday.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

$$
Forecaster Berg
 
For some reason last few years long range models always want to have a hurricane on the east coast taking they most unlikely path and running up into Georgia from Savannah or Jacksonville .

Reminds me of Irma during one point in its forecast, before it went up west Florida.
 
I know when these systems have such an elongated circ a lot can change in the modeling based on where the LLC eventually wraps up.
 
How accurate is NullSchool? I found multiple 40MPH winds. The highest wind I found was 42MPH, but couldn't do it again on 100 attempts. At 850, I found winds above 60 MPH.

UNADJUSTEDNONRAW_thumb_2.jpg
 
No circulation/weaker system like this can survive going over land/mtns better than a tight hurricane that can get unraveled. Not saying it will, but have seen many storms wait till the western Caribbean before bombing out.
 
No circulation/weaker system like this can survive going over land/mtns better than a tight hurricane that can get unraveled. Not saying it will, but have seen many storms wait till the western Caribbean before bombing out.
Webb said large waves just dont go away
 
044
ABNT20 KNHC 280501
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Tue Jul 28 2020

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

Shower activity associated with a low pressure area located about
750 miles east of the Windward Islands is gradually increasing
in organization. However, recent satellite-derived wind data
indicate that the circulation remains broad and elongated, and the
low does not yet have a well-defined center of circulation.
Environmental conditions are expected to become somewhat more
conducive for development, and a tropical depression or tropical
storm is likely to form during the next couple of days while the
system moves west-northwestward at 15 to 20 mph and approaches the
Leeward Islands. Regardless of development, locally heavy rains and
gusty winds are likely across portions of the Leeward Islands on
Wednesday and will spread westward to the Virgin Islands and Puerto
Rico Wednesday night and Thursday. Interests on these islands
should continue to monitor the progress of this system, and
tropical storm watches or warnings could be required for portions
of the area later today.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

$$
Forecaster Berg
 
Um the Euro isn't killing it off anymore it's weak but it tracks across the Keys and into the gulf this runecmwf_z500_mslp_watl_6.pngecmwf_z500_mslp_watl_7 (1).png
 
Looks like the Euro just stalls it around Tampa

Really interesting run though the whole thing has really sped up where if there is a storm it could be on Florida's doorstep by Saturday
 
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