2017 Global Model Runs Discussion (Out to day 16)

[DESTRUCTION5]

I've noticed on recent runs that the GFS spins up a short lived low off of SE FL this weekend, and brings it onshore. Perhaps something to watch.

Saw this as well. Been very consistent with spinning up a depression or weak TS and pressing across FL from the East.

[Patrick99]

I've noticed on recent runs that the GFS spins up a short lived low off of SE FL this weekend, and brings it onshore. Perhaps something to watch.

There is a large, broad area of convection affecting the general area right now......it coalesces into something, maybe?

[Frank2]

It went overhead this morning - the good news is so far it's tracking NE, into the Jose/Maria trough - may it continue to...

The 12Z GFS keeps insisting on a weak ~1010 mb low dropping south between FL and the Bahamas and dissipating SE of Miami by early next week. Hopefully just a mirage...

http://www.wpc.ncep.noaa.gov/mike/atl_gfs12.shtml

[gatorcane]

The GFS continues to go with this small low over SE Florida or adjacent waters for the weekend. Pretty good amount of vorticity too:

[gatorcane]

CMC has it in the SE GOM and larger:

[SFLcane]

Some rainy blustery wx in SFL..

[northjaxpro]

We are going to be in for a windy, wet pattern going into next week with the developing nor'easter and the potential Low Pressure area over South Florida/Eastern GOM.

Definitely an area to monitor down state over the weekend into next week.

[Vince_and_Grace_fan]

The GFS now show a hurricane-force medicane over the sourthern Mediterranean Sea with 976 hPa central pressure, strong 850 hPa vorticity and nice upper level divergence, so it would be tropical. However it's in very long range, the development starts at 180 hours and the peak is at 240 hours.
Some development although possible near that area in the next 1-2 weeks, sometimes other models also show subtropical or tropical-like lows.

[Frank2]

So far the NHC has not accepted the model output and did not include it in the 2 p.m. 5-day TWO. Just a guess, but perhaps they are thinking whatever forms will track northeast. This morning TWC said the front would be slow in arriving on the EC (probably late in the week) so that would be the same time as the trough arriving down here, in time for any TC development.

Frank

[OntarioEggplant]

So the 12Z Euro has two microstorms hitting NE FL... One at 138 hrs and another at 174 hrs. There is a third weaker one at 180 hrs too.

Weirdness. GFS has been showing similar too. The massive storm at 10 days in the Gulf is still there

[SFLcane]

Yep development today seems to point towards BOC or towards Texas. Other then the CMC its not really looking to tropical either.

[CrazyC83]

The GFS now show a hurricane-force medicane over the sourthern Mediterranean Sea with 976 hPa central pressure, strong 850 hPa vorticity and nice upper level divergence, so it would be tropical. However it's in very long range, the development starts at 180 hours and the peak is at 240 hours.
Some development although possible near that area in the next 1-2 weeks, sometimes other models also show subtropical or tropical-like lows.

That could be the remnants of Maria?

[Vince_and_Grace_fan]

That could be the remnants of Maria?

No, the initial low cames from Africa on this run. Although it seems that its formation is helped by the Ex-Maria's upper level stream modification, which cause significant jet turn toward North Africa.
https://www.tropicaltidbits.com/analysi ... _eu_16.png
https://www.tropicaltidbits.com/analysi ... _eu_20.png
https://www.tropicaltidbits.com/analysi ... _eu_24.png

But the CMC develops a cut-off Mediterranean cyclone from Ex-Maria and shows some possibility of subtropical or tropical transition after 200 hours.
https://www.tropicaltidbits.com/analysi ... _eu_36.png
https://www.tropicaltidbits.com/analysi ... _eu_41.png

[SEASON_CANCELED]

Hurricane off the Italian coast? Yeah ok

It would not be tropical at that latitude.

[Alyono]

Hurricane off the Italian coast? Yeah ok

It would not be tropical at that latitude.

should not use a disrespectful tone when you are 100 percent wrong

There have been numerous documented hurricanes in the Med, off of the Italian coast. That storm in the GFS IS tropical. You can get tropical development over cold waters

[LarryWx]

So the 12Z Euro has two microstorms hitting NE FL... One at 138 hrs and another at 174 hrs. There is a third weaker one at 180 hrs too.

Weirdness. GFS has been showing similar too. The massive storm at 10 days in the Gulf is still there

So the 12Z Euro has two microstorms hitting NE FL... One at 138 hrs and another at 174 hrs. There is a third weaker one at 180 hrs too.

Weirdness. GFS has been showing similar too. The massive storm at 10 days in the Gulf is still there

Yes, a really strange Euro run, indeed. In addition to the 3 teeny weeny lows you mentioned, I also see a broader 1012 mb surface low earlier coming westward to near Fort Pierce around hours 108-114! So, there are 4 different entities coming westward into FL between 9/30 and 10/3 and then moving out into the Gulf! They all form underneath the big high that camps out over the NE US. This illustrates what some of us were saying about being south of a strong surface high often actually being conducive for a low to form (due to low level convergence causing air to pile up and thus rise as JB explained). None of them may ever amount to much tropically due to shear. Most likely none of them will become a TC. However, perhaps this Euro along with the recent GFS/CMC runs is a reason that the SE US coast, especially FL, should monitor the area just east of FL for surprise tropical mischief just in case.

Even without tropical development, the Euro is showing nonstop strong onshore winds 10/1-4 for the SE US with the strongest centered on NE FL/SE GA. This run has winds just offshore as high as 40 knots just to the north of some of these microlows due to pinching of the gradient. Onshore winds actually continue into 10/6. What I'm becoming concerned about is coastal flooding near high tides in the CHS-St. Augustine corridor, especially around the full moon 10/4-6, as well as rip currents 10/1-4.

[Vince_and_Grace_fan]

should not use a disrespectful tone when you are 100 percent wrong

There have been numerous documented hurricanes in the Med, off of the Italian coast. That storm in the GFS IS tropical. You can get tropical development over cold waters

And the SST's in that area where the GFS shows the cyclone are still around 26 Celsius, so it can support the tropical formation/transition.
http://www.ifremer.fr/cersat/images/myo ... 170925.png

[LarryWx]

The 18Z GFS fwiw has onshore winds, sometimes strong, for the SE US coast from CHS southward through FL nonstop 10/1-12! This run may be overdoing things, but the idea of many days in a row of onshore winds has been showing up on a good number of model runs of various models. The astronomical highest tides of the month are 10/6-10, near and just after the full moon. This is something that coastal flooding vulnerable SE coasters might want to keep in the back of their head, especially CHS to St. Augustine.

[SoupBone]

Yep development today seems to point towards BOC or towards Texas. Other then the CMC its not really looking to tropical either.

Link?

[LarryWx]

Folks,
The 00Z GFS has a weak surface low form along a stationary front over Sofla on Friday. Then it moves on Saturday NE to ~100 miles E of Melbourne, where it stalls. Then it moves back SW to Sofla on Sunday followed by a westward move into the Gulf on Monday. It remains weak the entire time.
The CMC (take with a huge grain) has a low form just n of W Cuba on Friday followed by a move NE to just off SW FL, where it stalls and becomes a TC on Saturday. Then on Sunday it moves westward out into the Gulf as a TS and reaches N MX late on Tuesday.