Global Model Runs for W.Caribbean Early Season Development

[Vortex]

1645 UTC VIS increasing convergence and convection. Weak turning noted just offshore Nicaragua


http://www.ghcc.msfc.nasa.gov/cgi-bin/post-goes

[JonathanBelles]

HPC has it:

[Eyewall]

What is that website of that weather station.

[HURAKAN]

[JonathanBelles]

What weather station?

HPC is http://www.hpc.ncep.noaa.gov/

[Eyewall]

Some one had said that it was mention on tv about possible tropical development. And I wanted the website to that news station.

[JonathanBelles]

Oh, well my news station has mentioned it a few times.... abcactionnews.com
(although the website isnt gonna have it on there).

[Derek Ortt]

Canadian has not learned from last year, it is developing a CV storm in MAY

[Eyewall]

Is there any way possible we can get a hold to some local news stations off the mexico coast. That would give us more feedback.

[JonathanBelles]

from Jeff Masters Blog:

Possible development in the Western Caribbean or Eastern Pacific late this week
For the past 3-6 days, our most reliable global computer weather forecast models have been predicting the development of a low pressure system near or over Central America by Friday of this week. Given the persistence in the models in developing this low, we need to be alert to the possibility of a tropical depression forming in either the Western Caribbean or Eastern Pacific, on either side of Costa Rica and Nicaragua. It is uncertain which ocean basin such a storm might form in, and whether or not there will be a tropical wave around to help kick off development. It may be that the low pressure region will stay anchored over land south of the Yucatan Peninsula, preventing any development. This is the solution preferred by the ECMWF model in its last few runs. However, the GFS, NOGAPS, and Canadian models all predict a tropical depression might form in the Western Caribbean near Mexico's Yucatan Peninsula. In contrast, the UKMET shows development in the Eastern Pacific, on the Pacific side of Central America. Climatologically, May tropical storms are much more common in the Eastern Pacific than the Western Caribbean, so we should not discount the UKMET solution, even though it is an outlier. All five models predict that the Central American low pressure area will move northward towards the Gulf of Mexico, and wind shear may fall enough to allow a tropical depression to form should the low's center emerge over water. I'll be posting daily updates on the situation this week.

[Aric Dunn]

Canadian has not learned from last year, it is developing a CV storm in MAY

its not just the cmc ... the 12z gfs does as well .,

[JonathanBelles]

NWS Tampa 1:16p

.LONG TERM (WEDNESDAY NIGHT-MONDAY)...THE MAIN FEATURE IN THE
MODELS CONTINUES TO BE THE AREA OF LOW PRESSURE THAT MANY DIFFERENT
MODELS ARE FORECASTING TO DEVELOP OVER THE SOUTHWESTERN CARIBBEAN
SEA. THIS LOW ORIGINATES OVER THE EASTERN PACIFIC...THEN CROSSES
INTO THE CARIBBEAN. NORMALLY...TROPICAL DEVELOPMENT WOULD BE QUITE
SLOW DUE TO ALL THE LAND INTERACTION...SO THE GFS LOOKS TOO DEEP
WITH THE LOW. THE ECMWF HAS BASICALLY LOST THE FEATURE...AND HAS A
FRONTAL BOUNDARY APPROACHING LATE MONDAY. WE CAN`T RULE OUT SOME
SORT OF SYSTEM MOVING UP TOWARD THE GULF SINCE SO MANY INDEPENDENT
MODELS HAVE LATCHED ON TO THE IDEA...BUT AT THE SAME TIME...WE ARE
TALKING ABOUT A FEATURE THAT DOESN`T EVEN EXIST YET...OTHER THAN A
MASS OF CLOUDS SOUTH OF CENTRAL AMERICA. FOR NOW...I WILL ASSUME
ANYTHING THAT DOES MOVE NORTH WILL BE SEVERELY IMPACTED BY CENTRAL
AMERICA AND EMERGE AS A VERY WEAK SYSTEM. THIS WOULD KEEP PRESSURE
GRADIENTS ON THE WEAK SIDE...SO BEST BET SEEMS TO BE TO KEEP MAIN
EFFECTS OUT OF THE FORECAST AREA.

[NDG]

12z UKMET still develops an EPAC storm versus caribbean, closer to C.A. than other previous runs, in a way I disrigarding the UKMET becaue I noticed is that for the past 3 days or so it has been trying to spin up something in the EPAC too soon, when clearly all we still have is a very broad area of low pressure, long ways to go for something to develop in the EPAC.

[Vortex]

12Z Nogaps bring a strong tropical storm and copius rainfall to southern florida at the end of the run

H+180


https://www.fnmoc.navy.mil/wxmap_cgi/cg ... rp&tau=180


12Z at or nearing hurricane strength per pressure

https://www.fnmoc.navy.mil/wxmap_cgi/cg ... tr&tau=180

[KWT]

I still think the most likely idea is that the convection will develop in the EPAC and strengthen out there but not enough to become a tropical cyclone, it will then slowly head northwards towards the Sw Caribbean where it may well get more time around 96-120hrs to actually develop if it can get far enough away from land. In some regards the CMC track may not be that far off IMO thorugh to 144hrs anyway.

The convection off in the EPAc whilst good won't develop, i think that the area that the UKMO picks up but it would have to strengthen and develop a rotation from fresh, with the system the GFs and other models form there already is some sort of rotation present, all it needs is the warm waters, if any circulation develops in the EPAC convection then possible invest but I don't think that will happen yet.

[gatorcane]

snippet from latest NHC discussion of the low trying to form in the EPAC:

RECENT AND CURRENT PRES ANALYSES REVEAL
THAT THIS MOISTURE IS RELATED TO AN AREA OF GENERAL LOW PRES
WHICH COVERS THE FAR ERN PACIFIC FROM 03N-14N BETWEEN 84W-100W.
GLOBAL NWP MODELS AND ENSEMBLES SUGGEST THAT THIS AREA MAY
CONSOLIDATE FURTHER TO FORM A BROAD LOW CENTER DURING THE NEXT
FEW DAYS WITH AN EVENTUAL TRACK TO THE N TOWARD CENTRAL AMERICA.
HAVE INTRODUCED A BROAD LOW PRES IN THE 48 HOUR HIGH SEAS NEAR
09N89W. CURRENTLY...SCATTEROMETER DATA AND A FEW SHIP
OBSERVATIONS HAVE SHOWN WINDS IN THE 20-25 KT RANGE WITH
DIRECTION FROM SW TO NW WITHIN THIS AREA

[vbhoutex]

This is from our local met Jeff-not Jeff Masters:

Extended/Tropics:



For several days the GFS has been forecasting tropical cyclone formation in the W Caribbean Sea this weekend. Recently the CMC and NOGAPS have joined the GFS and are all three developing a fairly significant tropical system. Currently a broad area of low pressure extends in the EPAC from off the coast of Honduras to south of Mexico. The CMC forms a surface low within this broad low and brings it northward over C America and into the W Caribbean where it intensifies as it moves NNW along the E coast of the Yucatan. The GFS and NOGAPS also develop a surface low, but do so further east in the SW Caribbean Sea resulting in less land interaction and follow a similar track as the CMC…with the NOGAPS being far to the right and heading for S FL. Looking at visible images this morning the broad trough will likely start lifting northward..surface low may or may not form before moving into C America…if it does it would not survive the track over the rough mountainous areas anyhow. Expect new surface low to develop in the SW Caribbean Sea late this week and move NNW to N off the E coast of the Yucatan. Upper level winds appear favorable for development and sea surface temps. are plenty warm. All models have a decent tropical system in the SE Gulf of Mexico by this weekend or early the first week of June. Upper ridging over TX and troughing along the US E coast should support an exit of the system toward the N and then NNE and NE toward the US Gulf coast or FL. Will have to watch how ridging over TX reacts to digging short wave energy into the PAC NW and if the downstream ridge expands eastward blocking a trough capture of the system. Of course that is if anything develops to begin with.



Hurricane season begins June 1 and now is the time to review preparations and plans in the event a tropical storm or hurricane threatens the TX coast. Do not wait until a hurricane is in the Gulf of Mexico to make a plan or buy supplies. Sadly only 10% of the coastal population have any kind of hurricane or evacuation plan…a lot of people will have no idea what they are going to do!

[rainydaze]

And to think ya'll have been talking about this since May 9th...that's why I love this board and we still have a few more days before we even know if something will form and where.

[gatorcane]

Moisture in the SW Caribbean is rapidly on the increase, in fact, convection looking increasingly more impressive here than in the EPAC. Is it possible this area is the beginning of the low? It's right where the GFS has been been forecasting this low to develop. The GFS solution seems to be banking on the EPAC broad surface low to move ashore central america and allow the Western Caribbean area to be the main area of cyclogenesis. It seems to be a reasonable solution.

Persistence, persistence, persistence. If that SW caribbean convection can persist for 24+ hours its certainly an area that bears watching. Certainly the cloud tops are warming this afternoon as we head into the diurnal minimum.

[cycloneye]

And to think ya'll have been talking about this since May 9th...that's why I love this board and we still have a few more days before we even know if something will form and where.

That is true about this weather communuty.Since we began in late 2002 it has been this way all the time.