Posible GOM development?

[cycloneye]

2 PM TWO:

A broad area of low pressure could form by Sunday over the southern
Gulf of Mexico.Development of this system, if any, should be slow
to occur while it moves northward early next week.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...20 percent

[Steve]

Looks like UKMet has the wet side east of here - possibly focused on the AL/FL coasts. QPF 12z has a 2.5" blob of rain just off of Cape San Blas.

http://www.wpc.ncep.noaa.gov/qpf/p168i.gif?1443029672

It was 1.8" on the 00z and a little further west - just off Santa Rosa/Okaloosa County beaches. The real rainfall over the next few days is centered on the OBX. Earlier models put in a weak disturbance up that way ahead of whatever formed in the Gulf. It was impossible to tell if it was classifiable or not as most of the ones who indicated the surge had a closed circle or maybe one additional isobar ring. But apparently it's a wet scenario I guess with the front and whatever moisture is coming up just ahead of that. Vorticity shows up pretty well at 850mb and is a little south of where the coastal Carolina rainfall is.

[stormlover2013]

long ways out still, I am interesting to see if by friday the models are still showing this, they are still having a hard time with the overall pattern

[Steve]

2 PM TWO:

A broad area of low pressure could form by Sunday over the southern
Gulf of Mexico.Development of this system, if any, should be slow
to occur while it moves northward early next week.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...20 percent

There have been a few times where most of us, in association with the models and professionals, pretty much knew where to look for genesis. TD #10 crossing that mega TUTT and morphing into TD 12 became Katrina. Everyone was sure of the tenacity of that low, and it survived. Other times where there should have been systems, nothing formed or the spin just petered out (Chris I think was one of those a few years back). This is one that I'm just not sure on. I understand the models showing genesis, but they've been wrong a lot this year. At the same time, the Western Caribbean and BoC were probably destined to be an origin point at some time late this year provided the season didn't just shut down early. This isn't typical of El Ninos, but it seemed likely as we transitioned to the fall, we'd have a shot at lowering pressures on the Gulf/Atlantic side of Mexico and/or Latin America. And it looks like the models think it's going to happen. Since all of the major models are showing genesis, the main difference as to whether the origin point is east or west of the Yucatan or possibly even the Mexican Riviera where there currently is some unsettled weather. There is also a surge off the eastern facing coasts of Latin America. So maybe it will be a combination of factors within the pattern that lead to possible genesis. I'm not sold, and we probably won't know much more before Saturday or Sunday (outside of being able to watch subsequent model runs and the evolution of the pattern down there). Monday has sort of been the day the prognosticative models have been hinting at for the last 3-4 days. And they haven't been extending the time each run as they have in recent other scenarios. I'm pretty sure there will be lower pressure down in the Southern Gulf. And it's probably going to be moving somewhere between NNW and NNE ahead of the next front unless that stalls out and it intensifies. Then we'll have to re-examine surrounding environmental factors. But I think everything is basically just hype until the weekend. I'm not looking to hype anything personally, but I appreciate any and all insights, runs and discussion provided.

[ronjon]

Let's see what the mighty Euro says this afternoon although it has been inconsistent too. I'm thinking since we're so late in Sept, if we see shifts in track it'll be more toward the FL panhandle.

[stormlover2013]

looks like high pressure might save Florida but still longs way out, by friday models might not show anything lol

[floridasun78]

Looks like UKMet has the wet side east of here - possibly focused on the AL/FL coasts. QPF 12z has a 2.5" blob of rain just off of Cape San Blas.

http://www.wpc.ncep.noaa.gov/qpf/p168i.gif?1443029672

It was 1.8" on the 00z and a little further west - just off Santa Rosa/Okaloosa County beaches. The real rainfall over the next few days is centered on the OBX. Earlier models put in a weak disturbance up that way ahead of whatever formed in the Gulf. It was impossible to tell if it was classifiable or not as most of the ones who indicated the surge had a closed circle or maybe one additional isobar ring. But apparently it's a wet scenario I guess with the front and whatever moisture is coming up just ahead of that. Vorticity shows up pretty well at 850mb and is a little south of where the coastal Carolina rainfall is.

so now florida going to get rain when on tue was going more to west rain area

[Weatherwatcher98]

Our locals here on the west coast have talked about increased moisture coming up from the south for days. I think Steve is referring to the Panhandle of Florida though.

[tolakram]

12Z Euro has a barely perceptible area of vorticity heading from the yuk to Alabama between 96 hours and 144 hours.

[Stormcenter]

But remember it's the EURO and we know how poorly it performed this tropical season.
Anyway just the fact that it shows an area of vorticity like the other models is very telling.

12Z Euro has a barely perceptible area of vorticity heading from the yuk to Alabama between 96 hours and 144 hours.

[HURRICANELONNY]

I don't think it will matter much where the center forms or goes. The shear in the gom will be pretty high and all the moisture will be shunted north and east.

[Stormcenter]

Let's hope so.

I don't think it will matter much where the center forms or goes. The shear in the gom will be pretty high and all the moisture will be shunted north and east.

[floridasun78]

look miami weather looking at ncep because their say rain chance could higher next week first say was going dryer here what their say ISSUED 1003 AM EDT WED SEP 23 2015/LONG TERM (SATURDAY THROUGH TUESDAY): LESS COVERAGE OF SHOWERS AND
THUNDERSTORMS THIS UPCOMING WEEKEND AS MID/UPPER RIDGE BUILDS BACK
OVER AREA FROM THE SOUTH. RAIN CHANCES BACK TO NEAR NORMAL VALUES
FOR THE LATTER PART OF RAINY SEASON AND MORE DIURNALLY DRIVEN.
UNFORTUNATELY THIS DRIER PATTERN DOES NOT APPEAR TO LAST LONG AS
ANOTHER TROUGH IN THE GULF OF MEXICO AND EASTERN U.S. EARLY NEXT
WEEK BEGINS TO DRAW DEEPER MOISTURE BACK INTO THE AREA ALONG WITH
A SURFACE LOW PRESSURE FORECAST BY THE MODELS TO MOVE INTO THE
SOUTH-CENTRAL GULF OF MEXICO. REGARDLESS OF EXACTLY WHERE THIS LOW
TRACKS AND HOW DEFINED IT IS, RAIN CHANCES LOOK TO INCREASE ONCE
AGAIN ACROSS SOUTH FLORIDA EARLY NEXT WEEK.

[Ntxw]

It will be interesting to see it fight the shear, 50, 60, even 80kts nearby. That is a lot of shear. The other invests earlier in similar area battled 20-40 knots.

[Stormcenter]

And the shear supposed to be there 5 days from now?

It will be interesting to see it fight the shear, 50, 60, even 80kts nearby. That is a lot of shear. The other invests earlier in similar area battled 20-40 knots.

[floridasun78]

look mess in south west carribbean could that part of system for weekend

[Ntxw]

And the shear supposed to be there 5 days from now?

It will be interesting to see it fight the shear, 50, 60, even 80kts nearby. That is a lot of shear. The other invests earlier in similar area battled 20-40 knots.

Shear is there now, will increases stronger as ULL in the NGOM retrogrades into a big trof as it deepens, increasing effective shear in the GOM by early next week.

The same process that increases the shear also increases convection in the GOM thus development chances.

[NDG]

For those of you that are wondering how come the 12z Euro has not being posted yet is because it shows nothing more than a weak and broad surface low developing, subtropical looking if not extra tropical.

[stormlover2013]

does anyone have the GFS ensembles and EURO ensembles

[Stormcenter]

But it is on board with some sort of development and right now since there is nothing there I think that's what is important.

For those of you that are wondering how come the 12z Euro has not being posted yet is because it shows nothing more than a weak and broad surface low developing, subtropical looking if not extra tropical.