Area from NW Caribbean across Cuba to the Bahamas (now INVEST 99L)

[joey]

000
ABNT20 KNHC 271730
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Wed Sep 27 2017

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

The National Hurricane Center is issuing advisories on Hurricane
Maria, located east of Cape Hatteras, North Carolina, and on
Hurricane Lee, located over the central Atlantic Ocean.

An area of disturbed weather associated with a trough of low
pressure is located over the northwestern Caribbean Sea. This
system is forecast to move slowly north-northwestward across Cuba
and the Straits for Florida during the next day or so. Some
development of this system is possible when it moves near the
Florida peninsula or the northwestern Bahamas on Friday or Saturday
before upper-level winds become less favorable early next week.
Regardless of development, this system is likely to produce locally
heavy rainfall over portions of Cuba, southern Florida, the Florida
Keys, and the Bahamas during the next several days.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Brown

Chances should be higher than that, this is in quite favorable conditions

maybe as this mess moves north to the fl straight may be a higher chance imo

[BYG Jacob]

000
ABNT20 KNHC 271730
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Wed Sep 27 2017

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

The National Hurricane Center is issuing advisories on Hurricane
Maria, located east of Cape Hatteras, North Carolina, and on
Hurricane Lee, located over the central Atlantic Ocean.

An area of disturbed weather associated with a trough of low
pressure is located over the northwestern Caribbean Sea. This
system is forecast to move slowly north-northwestward across Cuba
and the Straits for Florida during the next day or so. Some
development of this system is possible when it moves near the
Florida peninsula or the northwestern Bahamas on Friday or Saturday
before upper-level winds become less favorable early next week.
Regardless of development, this system is likely to produce locally
heavy rainfall over portions of Cuba, southern Florida, the Florida
Keys, and the Bahamas during the next several days.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Brown

Chances should be higher than that, this is in quite favorable conditions

maybe as this mess moves north to the fl straight may be a higher chance imo

Ah, didn't realize this was still south of Cuba, that would explain it.

[Frank2]

Just to clarify, the Melbourne discussion posted earlier in this thread mentions "windy" several times - that is NOT due to TC development, but (as clarified by the forecaster) is pressure gradient in nature, due to strong high pressure moving off the EC. I spoke to a pro met earlier today and so far the models do not show any significant tropical development.

Frank

[ronjon]

Looks more like a frontal low that the models are developing east of Florida next week than a tropical low. Look at the low temps across the SE U.S. this Sunday.

Don't think so wxman since its origin is the disturbed weather south of Cuba - and we certainly haven't had any significant cool down here in Florida yet. It's still summertime heat and humidity down here. Haven't seen a dew point below 70 deg in 5 months. I think the mechanism for low pressure development is the disturbed weather and the high pressure clockwise circulation to its north.

[LarryWx]

Looks more like a frontal low that the models are developing east of Florida next week than a tropical low. Look at the low temps across the SE U.S. this Sunday.

Don't think so wxman since its origin is the disturbed weather south of Cuba - and we certainly haven't had any significant cool down here in Florida yet. It's still summertime heat and humidity down here. Haven't seen a dew point below 70 deg in 5 months. I think the mechanism for low pressure development is the disturbed weather and the high pressure clockwise circulation to its north.

I agree about the strong high to the north as it, as JB often explains, often leads to the south to lower level convergence/piling up of air at the low levels which then leads air rising and a sfc low forming. I wouldn't be surprised if this low were to have somewhat of a subtropical aspect but really don't know.

[LarryWx]

OK, the Euro still has it at 12Z with it forming late Fri near Melbourne, moving NE to ~100 miles E of St. Aug. Sat afternoon, and then coming back SW to Melbourne on Sunday afternoon followed by weakening.

[joey]

OK, the Euro still has it at 12Z with it forming late Fri near Melbourne, moving NE to ~100 miles E of St. Aug. Sat afternoon, and then coming back SW to Melbourne on Sunday afternoon followed by weakening.

will that be the same yellow x as per the nhc or another one thanks

[LarryWx]

OK, the Euro still has it at 12Z with it forming late Fri near Melbourne, moving NE to ~100 miles E of St. Aug. Sat afternoon, and then coming back SW to Melbourne on Sunday afternoon followed by weakening.

will that be the same yellow x as per the nhc or another one thanks

For the same yellow x

Aside: that 2nd low that was on the 0Z Euro further east and is also on this run technically may need a different yellow x but I wouldn't worry about it right now as it is very weak on this run. Can always address this later if it were to start showing up more strongly. Would rather not get into that one in detail and cause even more confusion lol.

[wxman57]

Looks more like a frontal low that the models are developing east of Florida next week than a tropical low. Look at the low temps across the SE U.S. this Sunday.

Don't think so wxman since its origin is the disturbed weather south of Cuba - and we certainly haven't had any significant cool down here in Florida yet. It's still summertime heat and humidity down here. Haven't seen a dew point below 70 deg in 5 months. I think the mechanism for low pressure development is the disturbed weather and the high pressure clockwise circulation to its north.

Doesn't matter where the moisture comes from. The models are developing a frontal low east of Florida, not a tropical cyclone. 12Z EC has dewpoints down to the upper 40s along the SC coast and into the mid 60s nearly to Orlando by Sunday morning. Definitely a cold front and a frontal low at least to start with.

[boca]

Wxman how much rain for S Fl?

[BYG Jacob]

Wxman how much rain for S Fl?

You're gonna need to know a guy named Noah

[Wx_Warrior]

Euro 12z 240


multiple images upload

[gatorcane]

Stronger on the 12Z ECMWF:

[gatorcane]

It's hard to believe the wide and expansive ridge over the CONUS that the global models are showing in the long-range with no cold front in sight. That looks nothing like this time of year.

[wxman57]

Wxman how much rain for S Fl?

Euro indicates widespread 2-4 inches across the southern third of the Peninsula by Tuesday. Not a whole lot, relatively. Higher amounts up around Cape Canaveral (4-6 inches).

[Emmett_Brown]

Stronger on the 12Z ECMWF:

Huge! Regarding Central American Gyres, in this case, is the Euro showing a gyre that consolidates into a TC, or is this still a case of the gyre spawning a TC? It looks so large, that I assume this is the gyre slowly consolidating...

[Wx_Warrior]

This is unreal....

[Agua]

Gyre:

Gyre, in oceanography and climatology, a vast circular system made up of ocean currents that spirals about a central point. The most prominent are the subtropical gyres, which ring subtropical high-pressure systems, and the subpolar gyres, which enclose areas of low atmospheric pressure over the oceans.

https://www.britannica.com/science/gyre

[WeatherEmperor]

It's hard to believe the wide and expansive ridge over the CONUS that the global models are showing in the long-range with no cold front in sight. That looks nothing like this time of year.

Usually the troughs that make it down to the Gulf Coast dont start showing until mid to late of October. That kind of pattern would shunt most tropical cyclones NE towards Cuba or Florida. Having strong ridging in early October does happen.


Sent from my iPhone 7 using Tapatalk

[BYG Jacob]

Gyre:

Gyre, in oceanography and climatology, a vast circular system made up of ocean currents that spirals about a central point. The most prominent are the subtropical gyres, which ring subtropical high-pressure systems, and the subpolar gyres, which enclose areas of low atmospheric pressure over the oceans.

https://www.britannica.com/science/gyre

How often does that happen in the GoM?