ATL: ISAAC - Models

[stormandan28]

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[Nikki]

if debby center doesnt relocate over night to the north then debby doesnt take that track, also if this storm hits mountains and disrupt it then the center can relocate and then who knows what happens, alot of scenarios

Debby?

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The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.


He is using Debby as an example of how models can be wrong when they miss a center relocation. In other words, if Debby's center did not relocate then the euro and the west track may have been correct. It's something to ponder, but in this case the Euro shows Isaac south of Hispaniola and Cuba, so it's not a relocation issue .. IMO. I don't think the GFS guessed a relocation either, it just got lucky. Again, just my uneducated opinion.

Thank you, that makes sense!!

[JPmia]

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I have a suspicion that we'll see further shifts west this afternoon considering the ensembles are now shifting a little west and well the west run of the EURO.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[uhvjaguars22]

The models are slowly going to shift west if this thing cant start wrapping around. And the ensembles are already heading towards ever so slightly jamaica

[x-y-no]

XYO so you're thinking the latest trend of the 06z GFS and the EURO might be telling us more left in the future tracks possibly?

I'm saying that over the years, the GFS has had an issue with weakening the mid-level ridge too much, usually at around 3 days or so. They've been tweaking it each season and last year it did perform much better, but this will be the best test so far of how successful they've been.

If you forced me to place my bet right now, I'd say Florida peninsula or eastern Gulf. But I wouldn't entirely rule out a track slightly east of Florida, just think it's a low probability.

[adam0983]

Models always go back and forth form east to west. We should not focus on the models at this time. We need to focus on the intensity of the storm and the how stong the weakness will be and how stong the ridge will be. This will be the future of Issac. The models are unreliable.

[boca]

XYO so you're thinking the latest trend of the 06z GFS and the EURO might be telling us more left in the future tracks possibly?

I'm saying that over the years, the GFS has had an issue with weakening the mid-level ridge too much, usually at around 3 days or so. They've been tweaking it each season and last year it did perform much better, but this will be the best test so far of how successful they've been.

If you forced me to place my bet right now, I'd say Florida peninsula or eastern Gulf. But I wouldn't entirely rule out a track slightly east of Florida, just think it's a low probability.

http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... tImage=yes

[uhvjaguars22]

Couldnt agree better

[Bocadude85]

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I have a suspicion that we'll see further shifts west this afternoon considering the ensembles are now shifting a little west and well the west run of the EURO.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

The majority of the ensembles are right on with the current NHC track. All of the GFS ensembles I have looked at the past few days showed gulf and east coast scenarios. I do think the NHC track will shift around the next few days though.

[Stormlover2012]

Euro also has high pressure building in southeast to push to la/Texas border maybe still a lot of time to watch

[cpdaman]

when talking about the euro ....remember there are euro ensembles.

yesterday it appear'd there was a good spread of euro members to the east of the OP run by looking at the 12z 120,144,168 ensemble images and the "stretch'd" low pressure appearence to the east and ne .

last nite the OP euro appeared a tad north in the 120-144 hr period on the op essential closer to cuba v. cozumel but still going thru the yucatan channel. the ensembles appeared to have a tad less spread then the 12z euro ensembles but still show that some members likely take isaac over parts of haiti as the "stretch'd isobars" to the east of a low pressure are an indication which shows model ensemble individual members spread to the east a tad.

here's the 12z eruo from yesterday http://raleighwx.americanwx.com/models/ ... SLP192.gif note the spread east on ensembles and the stretch'd isobar appearence
then here's last nite 0z ensembles (euro) http://raleighwx.americanwx.com/models/ ... SLP168.gif a bit less elongation probably a bit less ensemble member spread but would think the kink'd isobars over cuba indicate a member or two in the ensemble have isaac there

so w/ long range euro keep ensembles in mind

[Javlin]

XYO so you're thinking the latest trend of the 06z GFS and the EURO might be telling us more left in the future tracks possibly?

I'm saying that over the years, the GFS has had an issue with weakening the mid-level ridge too much, usually at around 3 days or so. They've been tweaking it each season and last year it did perform much better, but this will be the best test so far of how successful they've been.

If you forced me to place my bet right now, I'd say Florida peninsula or eastern Gulf. But I wouldn't entirely rule out a track slightly east of Florida, just think it's a low probability.

I am not real good on the terminology within some of these write ups but it seems to discuss some what you are bring up about the GFS and ridges XYO

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
348 AM EDT WED AUG 22 2012

VALID 12Z SUN AUG 26 2012 - 12Z WED AUG 29 2012

THE JET STREAM IS EXPECTED TO REMAIN SPLIT THROUGH THE UPCOMING
MEDIUM RANGE PERIOD...WITH ONE BRANCH EXTENDING FROM ALASKA TO
SOUTHERN ONTARIO/QUEBEC...AND ANOTHER SMALLER BRANCH ACCOMPANYING
A CLOSED LOW THAT DRIFTS INTO PACIFIC NORTHWEST. OVER THE
REMAINDER OF THE CONUS...A CORRESPONDING UPPER HIGH SHOULD BUILD
OVER THE CENTRAL/SOUTHERN ROCKIES...WHILE A BROAD WEAKNESS IN
MID/UPPER LEVEL HEIGHTS LINGERS OVER THE EAST COAST. DESPITE THE
COMPLICATED SHORTWAVE PATTERN EMBEDDED WITHIN THE LONGWAVE
FLOW...MODEL AGREEMENT IS QUITE GOOD THROUGH ABOUT DAY
4/SAT...WITH ALMOST ANY SOLUTION QUITE GOOD...EXCEPT FOR PERHAPS
OVER SASKATCHEWAN/ONTARIO WITH THE 00Z GFS SUSPICIOUSLY QUICK AND
APPEARING TO SUFFER FROM CONVECTIVE GRID-SCALE FEEDBACK.
BEGINNING WITH DAY 5/SUN HOWEVER...THE SPREAD QUICKLY INCREASES
PARTICULARLY WITH THE NORTHERN BRANCH OF THE JET CROSSING
CANADA...WITH THE GFS THE FIRST SOLUTION TO DEVIATE MOST FROM THE
CONSENSUS AND THUS LESS PREFERRED COMPARED TO THE 00Z ECMWF AND
ITS OWN ENSEMBLE MEAN...WHICH WILL FORM THE BASIS OF THE
PRELIMINARY PRESSURES/FRONT. REGARDING TS ISAAC...THE SOLUTION
SPREAD IS EXTREMELY LARGE...WITH THE 00Z CANADIAN THE FIRST TO
CURVE ISAAC TO THE NORTH...BRINGING ISAAC TOWARD MYRTLE BEACH BY
NEXT MONDAY...

[Wx_Warrior]

Here's hoping my Euro is out to lunch on its last 0z run.

[BigB0882]

That Euro track from last night sure reminds me of Gustav. I also think I had mentioned yesterday that it appeared the ridge was building in even stronger in the last frame and I asked if we could expect a more NW motion rather than N or NE. It looks like that is exactly what happened this morning. I guess I can read those maps a little after all, lol

[Weatherboy1]

I am very interested to see how the midday models look. Or in other words, if the GFS and other models shift more west in line with the euro ... or if they flip-flop a bit back to the east. This really is a nail-biter for us here in South FL in terms of how much wind, rain (if at all) we will get, or if this will miss us to the east or west. Still time to watch and wait before getting too worried, but the trend in the next 24 hours will be crucial. Is this a Georges (98) type scenario? Or more like Cleo (64)? Or even David (79)? Not sure yet, frankly.

[Javlin]

Another model will need a met to explain the resolution and any viability the model has?also these models are about 24hrs behind for preveiw.

The data assimilation system utilizes an 80 member ensemble (run at T382 resolution) to initialize a T878
control forecast using the hybrid variational/EnKF system. 20 T382 ensemble members are run out to 5 days,
along with a single T878 control forecast 4 times daily (at 0000, 0600, 1200, and 1800 UTC). These
experimental forecasts are made possible by support from the NOAA Hurricane Forecast Improvement Program (HFIP).

WARNING: These forecast are experimental and not intended to replace the official
forecasts issued by the National Hurricane Center and/or the National Weather Service.



http://www.esrl.noaa.gov/psd/forecasts/gfsenkf/

[SouthFloridawx]

Does this mean that it could still potential make it into the Gulf of Mexico? As in a Turn to the NE wouldn't be as soon as it has been expected?

[Javlin]

Does this mean that it could still potential make it into the Gulf of Mexico? As in a Turn to the NE wouldn't be as soon as it has been expected?

By that model the potential is there but you got to remember these are about 24 hrs old before the public I guess sees them.Then again go look at CMC and it's up the E coast.I am looking for trends myself I do know who or what EnKF is out there so a met might could clue us in.This same model could bend East today and we get to see it tomorrow.

[Weatherfreak000]

Watching models with an element of alert now. You can get the feeling model consensus is shifting west...see that wacky number TVCN did?

[Bocadude85]

Does this mean that it could still potential make it into the Gulf of Mexico? As in a Turn to the NE wouldn't be as soon as it has been expected?

Yes I think this does have potential to make it into the gulf.. Im not sure it will go as far as the EURO shows but who knows. I do think the 5 day position on the 11am update will be on the sw gulf coast of Florida. Just my opinion though.