Extratropical Depression Lee: Inland N Gulf States

Tropical Weather Discussions and Analysis
User avatar
tireman4
Global Moderator
Global Moderator
Posts: 4437
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Patience my dear Ed, patience.....
ticka1
Posts: 1265
Joined: Wed Feb 03, 2010 3:02 pm
Location: Baytown/Mont Belvieu
Contact:

Ed can be on the side for the half empty glass of optimism
while others like me will be on the other side of glass half full with optimism

WE JUST NEED RAIN.
skidog38
Posts: 88
Joined: Sun Feb 21, 2010 9:48 pm
Contact:

Allison is back
User avatar
Ptarmigan
Statistical Specialist
Statistical Specialist
Posts: 3982
Joined: Wed Feb 03, 2010 7:20 pm
Contact:

The computer models all agree something will develop. They don't agree on where it will go is the issue. When you average them out, it puts it around Southeast Texas.
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

00Z recap: GFS has TCG (tropical cyclone genesis) further E near New Orleans which is picked up by a diving East Coast Trough and swept NE along a colf front. The Canadian, on the other hand dvelops a cyclone, albeit weak, near SW LA and keeps it hugging the Coast moving WSW into the Middle TX Coast over a 3 day period. We'll see what the Euro and UKMET offer tonight in the model world 'wheel of fortune'...
Attachments
08312011 00Z Canadian 96 134_100.gif
08312011 00Z 108 135_100.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
Andrew
Site Admin
Site Admin
Posts: 3438
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

srainhoutx wrote:00Z recap: GFS has TCG (tropical cyclone genesis) further E near New Orleans which is picked up by a diving East Coast Trough and swept NE along a colf front. The Canadian, on the other hand dvelops a cyclone, albeit weak, near SW LA and keeps it hugging the Coast moving WSW into the Middle TX Coast over a 3 day period. We'll see what the Euro and UKMET offer tonight in the model world 'wheel of fortune'...

Canadian shows a scary run as you have an intensifying storm running up the Middle to uppper Texas coast. On the other hand though the canadian is known for "over doing" the intensity of storms. Tonight should be a LARGE lesson for many. When you don't have an established system or low the models will be all over the place. The GFS shows a possible east coast event while the canadian shows a Texas event. Where this develops, how fast it develops, and how strong it develops will tell us where it goes. The euro is coming up next. Lets see what is shows.
For Your Infinite Source For All Things Weather Visit Our Facebook
Andrew
Site Admin
Site Admin
Posts: 3438
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

For Your Infinite Source For All Things Weather Visit Our Facebook
User avatar
djjordan
Posts: 928
Joined: Fri Feb 05, 2010 7:19 pm
Location: Montgomery, Texas
Contact:

Even though we don't even have an invest yet, I'm tending to lean with the Euro more than any other models as it seems to have the right idea in slowly developing this system in the WGOM over the weekend into labor day. WIth all that moisture and a very slow moving system .... this could equal alot of rain for our parched selves. Still need to be on guard this weekend though.
~~~When Thunder Roars Go Indoors~~~
~~~Turn Around Don't Drown~~~
~~~Run From The Water, Hide From The Wind~~~
Andrew
Site Admin
Site Admin
Posts: 3438
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

Euro goes pretty crazy by letting it sit out there.
For Your Infinite Source For All Things Weather Visit Our Facebook
User avatar
djjordan
Posts: 928
Joined: Fri Feb 05, 2010 7:19 pm
Location: Montgomery, Texas
Contact:

Yep it does but if it sits out there as a weaker system, IMO that gives us a much better shot at sustainable rain for our drought stricken selves. That coupled with some weak steering currents, not a 0 Shear environment, I would think that would inhibit rapid intensification which if it is far enough south would turn our faucet off.
~~~When Thunder Roars Go Indoors~~~
~~~Turn Around Don't Drown~~~
~~~Run From The Water, Hide From The Wind~~~
Andrew
Site Admin
Site Admin
Posts: 3438
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

djjordan wrote:Yep it does but if it sits out there as a weaker system, IMO that gives us a much better shot at sustainable rain for our drought stricken selves. That coupled with some weak steering currents, not a 0 Shear environment, I would think that would inhibit rapid intensification which if it is far enough south would turn our faucet off.

Yea but Euro is still showing a cat 1 with 990mb. That would be a one two hit right there. Pretty much worse case scenario for Houston. Very interesting to see the spread from the Euro and Canadian to the GFS.
For Your Infinite Source For All Things Weather Visit Our Facebook
User avatar
djjordan
Posts: 928
Joined: Fri Feb 05, 2010 7:19 pm
Location: Montgomery, Texas
Contact:

Andrew wrote:
djjordan wrote:Yep it does but if it sits out there as a weaker system, IMO that gives us a much better shot at sustainable rain for our drought stricken selves. That coupled with some weak steering currents, not a 0 Shear environment, I would think that would inhibit rapid intensification which if it is far enough south would turn our faucet off.

Yea but Euro is still showing a cat 1 with 990mb. That would be a one two hit right there. Pretty much worse case scenario for Houston. Very interesting to see the spread from the Euro and Canadian to the GFS.
Yeah it is interesting to see that spread in all the models. Once we get an invest and start homing in on the center I'm sure these models will start making more sense. One thing for sure is the models are picking up on something going on this Holiday weekend.
~~~When Thunder Roars Go Indoors~~~
~~~Turn Around Don't Drown~~~
~~~Run From The Water, Hide From The Wind~~~
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

All right. Here is what HGX is thinking and as mentioned yesterday, until we actually get something to begin to form, the forecast is a guess at best:

ALL RIGHT...THE PART OF THE FORECAST EVERYONE WANTS TO KNOW
ABOUT. IS IT GOING TO RAIN THIS WEEKEND OR NOT? IF YOU LIVE
CLOSER TO THE COAST...YOU WILL HAVE BETTER CHANCES OF SEEING AT
LEAST A FEW DROPS. CONFIDENCE IN THIS FORECAST IS VERY LOW TO SAY
THE LEAST.

FIRST...TROPICAL WAVE IN THE NW CARIBBEAN IS NOT ALL THAT
ORGANIZED AND LOOKS TO POSSIBLY MOVE OVER THE YUCATAN PENINSULA.
HARD TO KNOW WHAT WILL REMAIN OF THE WAVE ONCE IT EMERGES INTO
THE GULF SOMETIME TOMORROW. THE WAVE IS NOT ALL THAT WELL DEFINED
BUT UPPER LEVEL WINDS MAY BE A LITTLE MORE FAVORABLE FOR
DEVELOPMENT EXCEPT FOR SOME WESTERLY SHEAR ACROSS THE NORTHERN
GULF WHERE THERE IS A WEAK UPPER LEVEL LOW. SAID ALL OF THIS TO
SAY THAT THE SYSTEM MAY BE SLOW TO DEVELOP AND LARGELY DEPEND ON
WHERE IT CAN DEVELOP A CORE OF CONVECTION.

SECOND...SINCE THE SYSTEM IS ILL-DEFINED...NONE OF THE MODELS
REALLY HAVE A GOOD GRIP ON HOW TO INITIALIZE IT OR HOW TO HANDLE
ITS EVOLUTION ONCE SOMETHING DOES FORM. THE NAM HAS BEEN THE MOST
CONSISTENT WITH DEVELOPING AT LEAST A TROPICAL CYCLONE OF SOME
SHAPE AND DEEPENING IT OFF THE LA COAST FRI. THINK IT WEAKENS THE
RIDGE TOO MUCH WHICH WILL STRETCH FROM THE S ROCKIES TO THE MISS
RIVER VALLEY. THE GFS AND ECMWF SOLUTIONS MINDS AS WELL BE POLAR
OPPOSITES WITH THEIR SOLUTIONS. GFS HAS A BROAD WEAK LOW ALONG
THE LA COAST AND MOVES IT EAST WITH TIME AND THEN UP THE EAST
COAST EARLY NEXT WEEK. THE ECMWF HAS A WEAK LOW FRI/SAT AND THEN
DEEPENS IT OFF THE LOWER TX COAST SUN. THE SYSTEM REMAINS IN THE
W GULF THROUGH MID OF NEXT WEEK BEFORE TURNING N INTO SE TX.
NEITHER OF THESE SOLUTIONS LOOK VERY REASONABLE AT THIS POINT.
THE SREF AND GFS ENSEMBLE MEAN PROBABLY OFFER AT LEAST SOME
GUIDANCE. THE SREF LIKE THE NAM DEVELOPS A LOW OFF THE LA COAST
BY FRI BUT IS MUCH WEAKER. SAME CAN BE SAID FOR THE GFS
ENSEMBLE. SREF DOES LOOK TO MOVE THE SYSTEM BACK TO THE WEST
SOME LIKE THE NAM AS WELL. THE MAIN TRICK WILL BE TO SEE IF A
STRONG SHORTWAVE TROUGH OVER THE NORTHERN TIER OF STATES WILL BE
ABLE TO PICK UP THE SYSTEM SUN/MON WITH THE UPPER RIDGE OVER THE
S ROCKIES AND WEAKENING OVER THE MISS RIVER VALLEY. THIS MAY OPEN
UP ENOUGH FOR THE SYSTEM TO PULL INLAND SUN/MON. ADD TOO THAT
THAT THE EXTENDED MODELS BRING A FRONT INTO THE REGION MON...THIS
TOO MAY GIVE REASON FOR THE SYSTEM TO PUSH INLAND IN THE SUN/MON
TIME FRAME.

SO UNTIL THE MODELS COME IN TO MORE AGREEMENT ON THE
DETAILS...BEST COURSE SEEMS TO BE TO GO WITH PARTS OF MODEL
SOLUTIONS THAT MAKE THE MOST PHYSICAL SENSE WHICH REALLY IS NOT
MUCH. ALIGNED POPS FOR THE REST OF THE WEEK AND WEEKEND KEEPING
IN MIND LOTS OF UNCERTAINTY BUT THAT THERE WILL BE SOME TROPICAL
DEVELOPMENT IN THE N GULF FRI. SYSTEM LINGERS IN THE N/NW GULF
THROUGH SUN WHEN STRONG SHORTWAVE ACROSS THE NORTH BEGINS TO PULL
IT INLAND SUN/MON. FRONTAL BOUNDARY THEN PUSHES INTO THE REGION
MON/TUE WHICH CLEARS EVERYTHING OUT AND MAY ACTUALLY BRING TEMPS
DOWN TO CLIMO NORMS WHICH WILL BE ABOUT 10-15 DEGREES COOLER THAN
TEMPS FROM THIS PAST WEEK. AGAIN...WILL REALLY HAVE TO WATCH THIS
SYSTEM BECAUSE QUITE POSSIBLE FOR THERE TO BE RAINBANDS TO AFFECT
THE AREA WHICH COULD BRING VERY HEAVY RAINFALL. STRONG EAST WINDS
THAT DEVELOP WOULD ALSO BUILD UP SEAS AND COASTAL FLOODING
THREAT. WHILE SE TX COULD USE THE RAINFALL...STILL LOTS OF OTHER
IMPACTS THAT WILL DEPEND ON THE DETAILS IN THE FORECAST WHICH
UNFORTUNATELY ARE SKETCHY AT BEST. GIVEN THE UNCERTAINTY AND THE
POSSIBILITY OF EXTREME IMPACTS TO THE AREA...BEST TO MONITOR
FORECAST TRENDS CLOSELY.



HPC thoughts:

A TROPICAL DISTURBANCE APPEARS DESTINED TO IMPACT AREAS
OF THE WESTERN AND CNTRL GULF OF MX DEPENDING ON THE MODEL CHOICE.
THE 00Z CMC IS MUCH MORE AGGRESSIVE CARRYING A POTENT H5 VORT MAX
INTO GALVESTON BAY BY 03/1200Z. SIMILARLY...THE 00Z UKMET ALSO
SHOWS A MODESTLY STRONG SYSTEM IMPACTING COASTAL LA BY SUN
MORNING. AS THESE SOLNS WERE RATHER EXTREME WITH SPREAD THAT WAS
ON THE HIGHER END...THESE MODELS WERE REMOVED AS OUTLIERS. FOR THE
EARLY PORTION OF THE PERIOD...A BLEND OF THE 00Z GFS/ECMWF WAS
UTILIZED BEFORE THE 00Z GFS BECAME A BIT MORE SUSPICIOUS. BY
SUN...THE 00Z GFS INDICATES A STRONG SFC CYCLONE SHOULD IMPACT THE
FL PANHANDLE WITH VERY FEW 12Z GEFS MEMBERS SUPPORTING A LOCATION
THAT FAR TO THE EAST. IT ALSO DID NOT AGREE WELL WITH ITS
PRECEDING THREE RUNS. IN ADDITION...THE GFS CONTINUES TO STRUGGLE
WITH A POTENT NE PAC SYSTEM ON MON WITH PRESSURES FCST TO BE MUCH
TOO DEEP. SO A BLEND OF THE 00Z ECMWF WITH THE GLOBAL MEANS WAS
UTILIZED FOR DAYS 4/5. THEREAFTER...TOO MUCH UNCERTAINTY IN THE
STRENGTH AND POSITION OF THE GULF OF MX DISTURBANCE LEAD TO MORE
OF AN ENS APPROACH TO CONCLUDE THE PERIOD OF INTEREST. IT DOES
APPEAR THE WESTERN GULF WILL BE FAVORED GIVEN THE MAJORITY OF THE
INDIVIDUAL ENS MEMBERS RESIDE IN THAT PORTION OF THE BASIN.
BUT...A MORE CONSERVATIVE APPROACH WAS UTILIZED GIVEN THE FCST
UNCERTAINTY IN PLACE.




Here are the Euro and SREF that HGX is mentioning...
Attachments
08312011 00Z 00zeurotropical850mbVortSLP192.gif
08312011 00Z sref_namer_087_500_vort_ht.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Here are the images of the FIM(GFS)/EnKF ensembles and another reason why the ensemble mean is being given some weight. This is experimental guidance that is used by forecasters and is rarely posted, so take it for what it is...
Attachments
08312011 00Z mslp2011083100_ATL_FIM-G7_ens_f126.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Here is what Lake Charles is thinking as well:

A DISORGANIZED TROPICAL WAVE IS NOTED ON SATELLITE APPROACHING THE
YUCATAN PENINSULA...IN AN AREA THAT TPC GIVES A 10 PERCENT CHANCE
OF DEVELOPING IN THE NEXT 48 HOURS.

THIS SYSTEM SHOULD CONTINUE TO MOVE WEST-NORTHWEST...WITH TROPICAL
MOISTURE FROM THE SYSTEM REACHING THE COASTAL WATERS LATER
TONIGHT...AND GRADUALLY INTO THE FORECAST AREA ON THURSDAY...THAT
WILL HELP INCREASE RAIN CHANCES...AND ALSO HELP LOWER DAYTIME HIGH
TEMPERATURES A BIT.

RAPID DEVELOPMENT OF THIS SYSTEM DOES NOT SEEM LIKELY AT THIS
TIME...AND THAT IS WHY MODELS SUCH AS THE NAM AND CMC ARE
DISCOUNTED. IN THE MID TERM...THE ECMWF SOLUTION SEEMS LIKE THE
BEST TO LOOK AT...AS IT IS REALLY CLOSE TO ITS ENSEMBLE MEAN AND
TO THE GFS ENSEMBLE MEAN. IN THIS SCENARIO...A SURFACE LOW
GRADUALLY DEVELOPS IN THE WEST CENTRAL GULF EAST OF THE LOWER
TEXAS COAST ON FRIDAY...AND MEANDERS AROUND THE NORTHWEST GULF
STAYING OFF THE EAST TEXAS COAST THROUGH THE HOLIDAY WEEKEND. THIS
WILL ALLOW A GRADIENT TO DEVELOP BETWEEN THE SURFACE LOW AND HIGH
PRESSURE TO THE NORTH...WITH A DECENT EAST TO SOUTHEAST FLOW
ACROSS THE FORECAST AREA. THIS SHOULD ALLOW AN INCREASE IN
TROPICAL MOISTURE...ESPECIALLY FROM I-10 TO THE SOUTH. DUE TO THE
UNCERTAINTY...HAVE KEPT POPS IN THE CHANCE RANGE AT THIS POINT
THROUGH THE WEEKEND. ALSO...IF A PROLONGED EAST TO SOUTHEAST FETCH
DOES DEVELOP...THIS COULD CAUSE SOME WATER PILING ALONG THE COAST
OVER THE WEEKEND...WHICH COULD LEAD TO HIGHER TIDES BETWEEN 1/2
AND 1 FOOT...AGAIN SUBJECT TO CHANCE ONCE POSITION OR STRENGTH OF
SURFACE LOW...IF IT DOES DEVELOP...COMES ABOUT.

STILL LOOKING AT THE POSSIBILITY OF A DECENT COLD FRONT FOR THIS
TIME OF YEAR...JUST AFTER THE HOLIDAY WEEKEND...WHICH MAY BRING DRIER AND
COOLER CONDITIONS...AND LIFT OUT ANY TROPICAL LOW.

Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
am19psu
Pro Met
Pro Met
Posts: 7
Joined: Fri Jun 17, 2011 5:49 pm
Contact:

The sensitivity to the genesis point is huge for this forecast. Until the models figure that out, we are going to be pretty much clueless. The farther west genesis occurs, the more likely this thing heads toward TX.
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

Morning e-mail from Jeff:


Weekend:
Now for the fun part! Uncertainty abounds with this system still this morning!

All models still develop some kind of tropical system in the NW/W/N Gulf this weekend and linger it around for a few to several days. Still do not think any one of the models has a better solution than the other. CMC dump the system altogether yesterday and now brings a hurricane to the upper TX coast. ECMWF develops a low off of KBRO and drifts it ENE and then SW and then around the middle of next week sends it back NW as a hurricane into the upper TX/SW LA coast. GFS develops a system off of S LA and moves it eastward toward NW FL. NAM continues to be aggressive in the short term and brings a strong TS toward Galveston Bay and then moves it slightly inland only to send it back offshore. Will not follow any of the guidance solutions, even though the ECMWF and NAM do have support from the GFS ensembles.

Will instead go with the general idea of a broad surface low forming somewhere in the central or NW Gulf late Friday and moving very slowly NW toward the middle/upper TX coast. System will likely slow/stall/meander near or offshore through much of the weekend before either moving WSW toward the lower/middle coast or turning NE toward the upper coast/SW LA. Would give slightly more credit to the WSW motion, but it may not be enough to get it inland as suggested by the 00Z ECMWF in which the system is left over the Gulf into the middle of next week getting stronger and stronger. System looks very large (broad) over the weekend and will likely be fairly disorganized at first. Point must continue to be made that the forecast is of little confidence and just about anything is possible, ,this is going to be a slow moving system that will have a prolonged impact for some areas. It is not going anywhere fast!

Impacts:
Will keep impacts general as there is so much uncertainty with the formation, track, and intensity that these aspects will certainly change over the next few days.

Will go with increasing rain chances Thursday-Monday if nothing else just for the increase in moisture. Should a surface low develop south or SW of the upper TX coast onshore flow on the east and north sides of the system would bring frequent squalls and rain bands, while a system developing S of LA would draw dry air southward cutting off rain chances. I am leaning toward the wetter side of things, but keeping those rain chances close to the coast (south of I-10) for now.

Another potential will be tides. Models are forecasting a decent pressure gradient to develop over the northern Gulf as pressures lower in the western Gulf. Long fetch ESE to SE wind on the east side of the possible tropical system will support both an increase in seas and tides. Seas will build into the 3-5 foot range by Saturday and 5-8 feet over the weekend (possibly higher). Favorable wind direction will support water movement toward the coast and expect the response to be increasing tides over the weekend. Tides could run 1-2 feet above normal over the weekend due to increasing swells and the favorable wind direction. Should the tropical system develop to our south these numbers will need to be bumped up some. There is the potential for a prolonged coastal flooding event given the very slow nature of this system, but how high both the seas and tides will go are uncertain until it can be determined where the surface low will likely form. Pattern is very similar to TS Frances 1998 which brought a prolonged storm surge of 6-8 feet to the upper TX coast over several days.

I would encourage residents to continue to monitor the weather forecasts for this weekend and early next week closely as rapid changes may be required depending on the evolution of the Gulf system.



Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
srainhoutx
Site Admin
Site Admin
Posts: 19611
Joined: Tue Feb 02, 2010 2:32 pm
Location: Maggie Valley, NC
Contact:

While the NAM has been considered an outlier (mainly because of intensity issues and early development), that model has backed down on storm strengthening early and but does paint and aminous forecast track for SW Louisiana and the Upper Texas Coast. Here are the rainfall totals that model is spitting out from the 12Z run. Coastal flooding from Lafayette to Galveston Bay would be a big issue as well...
Attachments
08312011 12Z nam_namer_084_precip_ptot.gif
Carla/Alicia/Jerry(In The Eye)/Michelle/Charley/Ivan/Dennis/Katrina/Rita/Wilma/Humberto/Ike/Harvey

Member: National Weather Association
Facebook.com/Weather Infinity
Twitter @WeatherInfinity
User avatar
djmike
Posts: 1702
Joined: Fri Jan 07, 2011 12:19 pm
Location: BEAUMONT, TX
Contact:

srainhoutx wrote:While the NAM has been considered an outlier (mainly because of intensity issues and early development), that model has backed down on storm strengthening early and but does paint and aminous forecast track for SW Louisiana and the Upper Texas Coast. Here are the rainfall totals that model is spitting out from the 12Z run. Coastal flooding from Lafayette to Galveston Bay would be a big issue as well...
Now if we could get all that to move just a tad more westward, I'd be a happy camper!! :D
Mike
Beaumont, TX
(IH-10 & College Street)
User avatar
Rip76
Posts: 1787
Joined: Mon Feb 15, 2010 12:38 am
Location: The Woodlands
Contact:

2 3/4 days for that to verify, is that a little soon?
Post Reply
  • Information
  • Who is online

    Users browsing this forum: No registered users and 18 guests