Tropical Storm Leslie - Can you say Irene........

This is going to possibly be yet another nail-bitter in the Atlantic. Tropical Storm Leslie was the second earliest named storm formation in history and was beat by Luis in 1995 by one day. Now, I immediately begin laughing at a lot of peeps out there on the internets saying this was obviously a fish right off bat. LMAO.. . Here is my totally unprofessional take on the situation.



Early forecast models were immediately forecasting this storm to strengthen quickly and move toward the North and the re-curve to la-la land and be a problem for the folks in Europe as some form of gale center. Folks, where have we seen this before. Anyhow, here is the first couple of model plots I animated for Leslie.



As you can see early on the models are ALREADY starting to shift towards the West, after two runs. The GFS Ensembles are much more pronounced.



If you can't tell, out of all the Ensemble members, only 2 do not have it stalling or hitting the east coast. Yesterday, they ALL were way off the coast.

Now, lets take a look as some Ensemble members of the GEFS. You can see the high pressure grid on the right and th low pressure grid on the left. These are also, shifting to the West .



I think the models under estimated the effects of the anticyclone to the North and West of Leslie. This is currently holding in check any major intensification at the moment and keeping Leslie on a more Westerly track before any possible recurvature at the moment. Now, why is this happening? There are a couple of simple solutions that might explain it.

Going back real quick a few weeks ago when I was talking about the uptick in tropical activity that I felt was going to start a week or two before it happened? One big thing I mentioned was Kelvin Wave Activity that was going to tremdoulsy enhance any Tropical activity. Well, It is at it again. This time, note that most of the northeasterly shear currently interacting with Leslie is also composing the upper-level easterly wind phase of the convectively-suppressed phase, of an equatorial atmospheric convectively-coupled Kelvin wave, currently over the western tropical Atlantic. In simple, It is shearing the system and between the rapid movement and the shear, the system will stay weaker longer than original anticipated by the models



This analysis suggests that the tropical cyclone may struggle to intensify due to an unfavorable interaction with this Kelvin wave for the next couple of days. If intensification were to stall, might we be seeing a slight threat for downstream landfall? Why is that? As been stated a gizzilion time this year, a weaker system will move more to the West, and a stronger system will move more to the North. This makes all the difference in the world in feeling, or not feeling the effects of any troughs anticipated to move off the East Coast.

Some weather service models are actually bringing Leslie close to the northern Lesser Antilles and Puerto Rico at this hour and then moving here more North.

http://cup.aos.wisc.edu/cgi-bin/tcget.cgi?time=LESLIE12L.20120831_06&field=MSLP%2FWind&hour=Animate

Another major factor is the trough moving through the lakes. The 12z run is not nearly as amplified or as deep as the 06z run so it would affect if, when, how far West and how and when a recuvre would occur. So many unanswered questions once again.

So, here is a simple breakdown so far for Leslie. Yesterday, she felt the trough coming off the East coast and performed an almost immediate recurve. Today, Leslie is weaker, may be coming decoupled. hauling ass, and may not feel the effects of the trough bringing here must closer to the East Coast. One thing that will be interesting to watch also. Remember our friend Isaac, what affects, if any will he have on the future track of Leslie. I feel strongly that she will effect the East Coast somewhere, more so from the Carolinas to Canada. Stay tuned.

West she goes!..and West she stays...That ridge over the East Coast is just starting to build...Time it completes it's Task ole Leslie will be somewhere in the Caribbean South of Cuba..The East Coast Ridge and the Bermuda high will bridge . The Bermuda High got displaced by the Jet Stream due to Isaac's weakening the Highs Western side. Then when it was weak Kirk split it....Now it builds back in from the East and the West...

gomexwx wrote:West she goes!..and West she stays...That ridge over the East Coast is just starting to build...Time it completes it's Task ole Leslie will be somewhere in the Caribbean South of Cuba..The East Coast Ridge and the Bermuda high will bridge . The Bermuda High got displaced by the Jet Stream due to Isaac's weakening the Highs Western side. Then when it was weak Kirk split it....Now it builds back in from the East and the West...

E, thanks for the update. As always great job.

Watch this....You can actually see Isaac weaken the Bermuda High. Then the Bermuda High gets hit hard...The Jet Stream took advantage of Isaac's weakness so did Kirk. As it progresses you will see Kirk with help from the trough riding the Jet Stream, split the Bermuda High....That was the power of Isaac and how he disrupted the atmosphere...Now the ridge builds back.

http://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8dlm1/wg8dlm1java.html

Aerial View of Flooding in Plaquemines Parish, Louisiana.



Intentional Levee breach near Braithwaite community in Plaquemines Parish



Sections of LA 1 washed out by #Isaac near Grand Isle



I-10 remains Closed between New Orleans and Baton Rouge due to flooding.



Incredible #Tornado picture near Calvert, Alabama



Tornado near Pascagoula, MS



Braithwaite, LA earlier today (3 story home)

My buddies from the NHC must have read my post. LOL

000
WTNT42 KNHC 312037
TCDAT2

TROPICAL STORM LESLIE DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012
500 PM AST FRI AUG 31 2012

THE STORM LOOKS A LITTLE BETTER ORGANIZED ON VISIBLE IMAGERY THIS
AFTERNOON WITH AN INCREASE IN CONVECTION IN ADDITION TO MICROWAVE
OVERPASSES SHOWING THE CENTER BECOMING MORE EMBEDDED IN THE
OVERCAST. INTENSITY ESTIMATES...HOWEVER...ARE UNCHANGED...SO THE
INITIAL WIND SPEED IS KEPT AT 55 KT. WHILE THE VERTICAL SHEAR IS
EXPECTED TO REMAIN LIGHT-TO-MODERATE IN THE SHORT TERM...MOST OF
THE GLOBAL MODELS ARE NOW SHOWING AN INCREASINGLY HOSTILE
ENVIRONMENT AFTER THAT TIME. THESE CONDITIONS ARE DUE TO AN
UPPER-LEVEL HIGH MOVING WEST OF THE CENTER...CAUSING AN INCREASE IN
NORTHWESTERLY SHEAR. MOST OF THE INTENSITY GUIDANCE NOW SHOW
LESLIE ONLY AS A CATEGORY ONE HURRICANE IN A FEW DAYS TIME. THE
OFFICIAL FORECAST IS REDUCED SLIGHTLY FROM THE PREVIOUS ONE...IN
BEST AGREEMENT WITH A BLEND OF THE INTENSITY CONSENSUS AND THE LGEM
MODEL. THERE IS SOME CHANCE OF LESLIE FINDING A MORE FAVORABLE
ENVIRONMENT IN THE LONG TERM...BUT ITS LIKELY SLOW MOTION AT THAT
TIME COULD CAUSE UPWELLING UNDER THE STORM...SO THE NHC FORECAST
WILL STAY CONSERVATIVE.

A SERIES OF MICROWAVE PASSES GIVES A GOOD INITIAL MOTION ESTIMATE OF
295/16. THERE HAS BEEN A SUBTLE WESTWARD SHIFT IN MOST OF THE
RELIABLE MODEL GUIDANCE DURING THE FORECAST PERIOD...PERHAPS
INITIALLY DUE TO THE RIDGE BETWEEN KIRK AND LESLIE BEING A BIT
STRONGER THAN EXPECTED. THE GLOBAL MODELS ARE CONSISTENT IN
FORECASTING A BREAK IN THE SUBTROPICAL RIDGE IN A FEW DAYS
TIME...WHICH SHOULD CAUSE LESLIE TO TURN NORTHWESTWARD AND
NORTHWARD IN 3 TO 4 DAYS. BY THE END OF THE FORECAST...LITTLE
MOTION IS EXPECTED AS THE CYCLONE IS CAUGHT IN LIGHT STEERING
CURRENTS TO THE SOUTHEAST OF BERMUDA. THE OFFICIAL NHC PREDICTION
IS SHIFTED WESTWARD TO COME CLOSER TO THE DYNAMICAL MODEL
CONSENSUS... ALTHOUGH THE MODEL CONSENSUS IS STILL A BIT WEST OF
THE NEW FORECAST.


FORECAST POSITIONS AND MAX WINDS

INIT 31/2100Z 16.7N 51.0W 55 KT 65 MPH
12H 01/0600Z 17.7N 53.2W 60 KT 70 MPH
24H 01/1800Z 18.9N 55.9W 60 KT 70 MPH
36H 02/0600Z 20.1N 58.1W 65 KT 75 MPH
48H 02/1800Z 21.5N 60.0W 70 KT 80 MPH
72H 03/1800Z 24.1N 62.0W 70 KT 80 MPH
96H 04/1800Z 26.0N 62.5W 70 KT 80 MPH
120H 05/1800Z 27.0N 63.0W 75 KT 85 MPH

$$
FORECASTER BLAKE

Leslie looks rather impressive this morning.



One thing the NHC is having a problem with is that the don't know exactly were the center is this morning. But, for now, Leslie looks very well on Satellite .
The latest model runs now have Leslie going back to the East. This has definitely been the year of uncertainties.





The models are also becoming in agreement that Leslie will begin to encounter more shear over the next day or two. They hold back on intensity of turning into a major storm for now.


Could you image this thing if it were moving towards the West this morning. There would be mass hysteria in the land of the internets.



As far as the future track of Leslie, I do not currently see any reason why NHC is off with their position and subsequent reasoning at this time. The models are tightly clustered, and they "seem" to fit with what is observable of the surrounding influences; not just modeled, but vapor imagery shows a strong steering level trough diving South around 70 W axis. The natural "mind's eye" conclusion is that the southern end of this trough would tend to sever, perhaps creating a strong TUTT- like gyre somewhere E of the Bahamas. I don't see Leslie careening through any such feature. And it thus also physically makes sense that Leslie would be influenced by that; a few models, including the operational Euro, indicate a severed gyre. That would lend to N motion out in time.

That said, I see some philosophies that cannot yet be discounted. One would be a North drift/slow motion/virtual stall, after which a resumed motion is unknown, because by day 6 the actual synoptics and the modeled synoptics have increased potential of parting company. Another possibility would include the chance that a North motion would leave Leslie eventually vulnerable to the westerlies and POOF, see you later. I do find it interesting that the recent 2 to 3 cycles of the GFS have indicated a less aggressive polarward position by the late middle range periods - if nothing else, that indicates uncertainty with handling the steering fields out in time. Yet a 3rd possibility, is however more unlikely, is that Leslie briefly goes North, stalls, then resumes a west motion, as said TUTT-like feature moves WSW and ridging reforms near Bermuda. None of these possibilities can be discounted with certainty as we are talking a minimum of 5 days before the final outcome will become clear.

Thanks for the update E.

Thanks E. Could someone do me a favor and turn the fans East? I haven't finished moving in yet..... TIA

GrillinInTheEye wrote:Thanks E. Could someone do me a favor and turn the fans East? I haven't finished moving in yet..... TIA

No problem Grill. All I have to do is say it is heading West of due West and it will go in opposite direction. LOL

LOL. Thanks E. Greatly appreciated..

I think Leslie is playing her version of sit n spin...LOL..Nothing like waiting on the Taxi

Leslie Sucks