Remnants of Matthew Inland Over Southern Mexico

[srainhoutx]

Hour 324...

[srainhoutx]

Hour 384...Florida bound...

[srainhoutx]

What is concerning is seeing some agreement today regarding the size of this potential system. The GFS has joined the Euro suggesting a very large storm.

[srainhoutx]

The 12Z Euro has come in similar to the GFS with a track NE from the Western Caribbean toward the Florida Straits. Timing, well that is a different story. The Euro moves the system near the FL Straits @ hour 192 where the GFS takes 324 hours to move it near Tampa. Hmmm...

[kellybell4770]

so are the chances of it coming west instead of east pretty slim at this point or is it still totally up in the air?

[srainhoutx]

It all depends on when and where this forms and what is going on across the CONUS at that time. My guess is that the models are 'sniffing' a big pattern change across the Western Atlantic Basin in regards to a favorable MJO pulse (the strongest this season) and a robust Kelvin Wave entering the Caribbean Sea. Should we get a cold front this weekend into SE TX, then I would think our chances of having any Tropical Trouble would decrease. But as I always say, we will see.

[srainhoutx]

HPC thoughts: A lot of uncertainty from what I am reading...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
158 PM EDT MON SEP 20 2010

VALID 12Z THU SEP 23 2010 - 12Z MON SEP 27 2010

CLOSED LOWS LIE TO THE NORTH AND SOUTH OF ALASKA TO THE EAST AND
WEST OF 140W... RESPECTIVELY. THIS COUPLED WITH BUILDING RIDGING
IN WESTERN NORTH AMERICA /WHICH SHOULD KEEP THE INTERMOUNTAIN WEST
WARM/ WILL FORCE DOWNSTREAM TROUGHING OVER THE EASTERN US BY THIS
WEEKEND. RECENT OPERATIONAL MODEL RUNS HAVE VARIED IN THE STRENGTH
OF SAID TROUGHING FROM A CLOSED LOW SEPARATING FROM THE FLOW AND
DROPPING TO NEW MEXICO /ECMWF RUNS FROM 19 SEPT/ TO A PROGRESSIVE
TROUGH MOVING INTO THE ATLANTIC /GFS/. THESE DIFFERENCES OCCUR
DOWNSTREAM OF THE EXTRATROPICAL TRANSITION OF WHAT IS NOW WESTERN
PACIFIC TROPICAL DEPRESSION 13W...WHICH BOTH THE 00Z CANADIAN/00Z
ECMWF KEEP AS A STRONG SYSTEM WHILE THE 06Z GFS WAS QUITE WEAK
LATE IN THE PERIOD. THE ENSEMBLE MEAN SOLUTIONS SHOW SIGNIFICANT
DISAGREEMENT AS TO WHERE TROUGHING IN THE EASTERN PACIFIC IS
EXPECTED TO LIE LATE IN THE PERIOD...WHICH LEADS TO PRONOUNCED
DIFFERENCES OVER THE LOWER 48 UNITED STATES. THE PRESENCE OF A
TROPICAL CYCLONE UNDERGOING EXTRATROPICAL TRANSITION UPSTREAM AND
DISAGREEMENT WITHIN THE GUIDANCE...AS WELL AS THE ECMWF POOR
CONTINUITY...LEADS TO LOW CONFIDENCE IN THE FORECAST ACROSS THE
EASTERN TWO-THIRDS OF THE UNITED STATES LATE IN THE MEDIUM RANGE
PERIOD.

THE 00Z/20 ECMWF HAS STUCK WITH CLOSING OFF AN UPPER LOW NEAR
KANSAS CITY BY SUN/D6 WHILE THE 00Z GFS/UKMET/CANADIAN ARE MORE
PROGRESSIVE LIKE THE ENSEMBLE MEANS. EVEN HERE... THE 00Z
GEFS/NAEFS ARE FASTER THAN THE 00Z CANADIAN ENS MEAN AND 12Z ECMWF
ENS MEAN. THE ECMWF HAS SHOWN LARGE CONTINUITY CHANGES WITH THIS
SYSTEM OVER ITS PAST COUPLE DAYS OF RUNS...LOWERING OUR CONFIDENCE
IN THIS PIECE OF GUIDANCE. TELECONNECTIONS WITH THE NORTHERN
STREAM RIDGING IN WESTERN CANADA FAVOR ENERGY MOVING NEAR THE
WESTERN US/CANADIAN BORDER THROUGH THE NORTHERN ROCKIES LATE IN
THE PERIOD...NOT A CLOSED LOW IN THE MIDWEST. FOLLOWED ALONG THE
LINE OF HPC CONTINUITY BY USING A 00Z ECMWF/GFS AND 12Z ECMWF
ENSEMBLE MEAN BLEND EARLY ON AS AN INITIAL SYSTEM MOVES THROUGH
THE GREAT LAKES AND NORTHERN NEW ENGLAND BEFORE TRANSITIONING TO A
00Z CANADIAN/GFS AND 12Z ECMWF ENSEMBLE MEAN BLEND FOR SUNDAY AND
NEXT MONDAY WHICH KEEPS HIGH PRESSURE DOMINANT ACROSS MUCH OF THE
CENTRAL US AS THE WESTERLIES ARE FORCED THROUGH SOUTHWESTERN
CANADA.

ENOUGH TROUGHING IS FORECAST TO MOVE THROUGH THE EAST TO ALLOW FOR
A PROGRESSIVE FRONTAL ZONE THROUGH THE EAST INTO MEXICO....THOUGH
THERE IS A QUESTION MARK CONCERNING WHERE ANY POSSIBLE CLOSED
CYCLONES WOULD FORM WITHIN THE EASTERN TROUGH WHICH MAKES PINNING
DOWN RAINFALL THIS FAR OUT HIGHLY UNCERTAIN NEAR AND EAST OF THE
APPALACHIANS FROM THIS WEEKEND INTO EARLY NEXT WEEK. COORDINATION
WITH TPC LED TO THE TROPICAL WAVE PROGRESSION IN THE WESTERN
CARIBBEAN AND WENT WITH THEIR IDEAS IN THE EASTERN PACIFIC THROUGH
THE PERIOD.

ROTH/FRACASSO

[srainhoutx]

HGX thoughts:

BOTH THE ECM/GFS ARE TRYING TO SPIN SOMETHING UP IN THE CARIBBEAN
AND EVENTUALLY MOVE IT NORTH INTO THE EASTERN GULF OR SOUTHEAST OF
FLORIDA BETWEEN THE 26TH AND 28TH. STILL WAY TO EARLY FOR ANY
CONFIDENCE IN ANYTHING EVEN DEVELOPING AND FOR THAT MATTER THAT
TRACK.

[desiredwxgd]

Lake Charles AFD



.DISCUSSION...
ISOLATED TO WIDELY SCT SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE
THROUGH THE EARLY EVENING HOURS...THEN DISSIPATING WITH THE LOSS
OF DAYTIME HEATING. OVERALL...FEW CHANGES TO THE FCST ARE
EXPECTED OVER THE NEXT SEVERAL DAYS. THE AREA WILL REMAIN UNDER
THE WRN PERIPHERY OF HIGH PRESSURE ALOFT WITH SFC HIGH PRESSURE
RIDGING TO PERSIST THROUGH LATE IN THE WEEK. EAST TO SOUTHEAST
FLOW WILL MAINTAIN ENOUGH LOW LEVEL MOISTURE TO KEEP A SMALL
CHANCE FOR DIURNAL CONVECTION EACH DAY. BY SATURDAY...THE UPPER
LEVEL RIDGE WILL WEAKEN AS A TROUGH MOVES EAST ACRS THE CNTRL
PLAINS INTO THE OHIO VALLEY...HELPING TO PUSH A COLD FRONT TOWARD
THE AREA. AT THIS TIME...KEPT LOW END CHC POPS IN THE FCST
SATURDAY WITH CONVECTION ASSOCIATED WITH THE FRONT. A LITTLE
DRIER AIR WILL FILTER IN BEHIND THE FRONT FOR SUNDAY...WITH
TEMPERATURES NEAR NORMAL SUNDAY INTO MONDAY. AT THIS TIME...LEANED
TOWARD THE GFS SOLUTION FOR THE EXTENDED PORTION OF THE FCST AS
THE ECMWF IS STILL AGGRESSIVE ON CUTTING OFF THE 5H LOW OVER THE
MID MS/OHIO VALLEYS.

[sambucol]

If we get the cold front through here, will that mean we are not likely for any tropical development to head our way?

[Andrew]

If we get the cold front through here, will that mean we are not likely for any tropical development to head our way?

More or less yes. If it isn't too late or early it should protect us.

[sambucol]

If we get the cold front through here, will that mean we are not likely for any tropical development to head our way?

More or less yes. If it isn't too late or early it should protect us.

Reminds me of Ike when the cold front was supposed to keep it away from us. But we know the rest of that story.

[srainhoutx]

Here is the problem with the EC and GFS. A totally different Upper Air Patter is depicted by each...

[srainhoutx]

Sunset on PGI46L...

[biggerbyte]

Wow! That far out and it is all pure speculation. Does lend the possibility to the conversation. First we have to get a system to form at all. Next, what will the conditions be at the time it does. Too many possible variables at this point to make a west gulf, or north/ne gulf call. I'd be careful to put all my apples in either basket for a few more days.

Also, it looks like we could be active until mid October this year.

Keep a wise eye to the sky, newbies. The fun may begin in just a few days.

[Andrew]

Here is the problem with the EC and GFS. A totally different Upper Air Patter is depicted by each...

Yea the Euro shows a dominating ridge while the gfs shows an early fall pattern.

Where do you get these awesome pictures srain?

[srainhoutx]

Here is the problem with the EC and GFS. A totally different Upper Air Patter is depicted by each...

Yea the Euro shows a dominating ridge while the gfs shows an early fall pattern.

Where do you get these awesome pictures srain?

Oh, I had help through the years...

[Ptarmigan]

I wonder why PGI46L is not tagged as an Invest? Here is a 324 Hour GFS model and it has a monster hurricane in the Gulf of Mexico. Looks larger than Gilbert! If named, it would be Matthew.

[srainhoutx]

Microwave pass caught some of 46...

[biggerbyte]

We may get a cool front through here over a Sunday/Monday timeframe. That would be out of the area long before a system in the Gulf gets cranking. We will need another front, or a strong trough digging down just at the right time to be completely safe. Maybe... Maybe not. That graphic looks scary.