ATL: TROPICAL DEPRESSION ALEX - DISCUSSION

[NWFWatcher]

Ok Ivanhater do you feel we have anything to worry about here on the panhandle.

[jinftl]

From NHC Discussion at 11pm:

THE OFFICIAL NEW FORECAST
IS QUITE SIMILAR TO THE PREVIOUS ADVISORY...AND CLOSELY FOLLOWS A
CONSENSUS OF THE DYNAMICAL MODELS THAT EXCLUDES THE GFS...SINCE THE
LATTER MODEL APPEARS TO BE SOMEWHAT OF A NORTHERN OUTLIER AT THIS
TIME.

So based on that post, they don't appear to think Alex (45mph now), will take the northern solution.

[Brent]

[CrazyC83]

I would have turned it a bit more right on the track. Also I do think the large size might slow strengthening initially.

[brunota2003]

Didn't the GFDL have this thing crawling through here during one of it's runs a few days ago?

[ozonepete]

Bottom Line is that the NHC doesn't have a heck of a lot of confidence in this forecast. Who would considering the big divergence in model output? Strength has always been a problem with the models. But they usually have a better take on track than this. A very interesting forecasting problem. Guess we'll just have to watch and wait.

[ROCK]

sticking with the previous track....so they are still siding with the southern camp...

[jinftl]

Looking at the NHC wind probability distributions over the last 3 advisories shows Brownsville's %'s going up while Tampico's have gone down some. The highest probability distributions shows a definite focus on landfall from Brownsville to La Pesco.

North of Freeport, there hasn't been the increase in the likelihood of 34kt, 50kt, and 64kt winds that south texas has seen. If we see the NHC probabilities start to go up north of Freeport, that would definitely indicate a shift in focus north from the current forecast track.

WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS

CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST
...34 KT (39 MPH... 63 KPH)...
...50 KT (58 MPH... 93 KPH)...
...64 KT (74 MPH...119 KPH)...
FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS

1st % = 11am, 6/27 advisory
2nd % = 5pm, 6/27 advisory
3rd % = 11pm, 6/27 (latest) advisory

PORT ARTHUR 34 KT 4% 7% 8%
PORT ARTHUR 50 KT 0% 0% 0%
PORT ARTHUR 64 KT 0% 0% 0%

GALVESTON 34 KT 7% 12% 12%
GALVESTON 50 KT 0% 3% 3%
GALVESTON 64 KT 0% 1% 1%

HOUSTON 34 KT 6% 10% 10%
HOUSTON 50 KT 0% 0% 0%
HOUSTON 64 KT 0% 0% 0%

FREEPORT 34 KT 9% 14% 15%
FREEPORT 50 KT 0% 3% 4%
FREEPORT 64 KT 0% 1% 1%

PORT O'CONNOR 34 KT 13% 19% 21%
PORT O'CONNOR 50 KT 0% 6% 6%
PORT O'CONNOR 64 KT 0% 2% 3%

CORPUS CHRISTI 34 KT 17% 22% 24%
CORPUS CHRISTI 50 KT 5% 6% 7%
CORPUS CHRISTI 64 KT 1% 1% 2%

BROWNSVILLE TX 34 KT 39% 41% 45%
BROWNSVILLE TX 50 KT 12% 14% 17%
BROWNSVILLE TX 64 KT 4% 6% 8%

LA PESCO MX 34 KT 47% 44% 48%
LA PESCO MX 50 KT 17% 16% 16%
LA PESCO MX 64 KT 6% 5% 6%

TAMPICO MX 34 KT 45% 39% 39%
TAMPICO MX 50 KT 15% 12% 13%
TAMPICO MX 64 KT 5% 5% 5%

VERA CRUZ MX 34 KT 22% 18% 18%
VERA CRUZ MX 50 KT 4% 4% 3%
VERA CRUZ MX 64 KT 1% 1% 0%

[bahamaswx]

Already popping IR greys over the COC. Very impressive. Wouldn't be surprised to see a fairly tight CDO by morning.

[cycloneye]

Code: Select all

 - MAXIMUM WIND SPEED (INTENSITY) PROBABILITIES - - -     

VALID TIME   12Z MON 00Z TUE 12Z TUE 00Z WED 00Z THU 00Z FRI 00Z SAT
FORECAST HOUR   12      24      36      48      72      96     120 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DISSIPATED       X       1       2       2      12      25      53
TROP DEPRESSION  9      11      10       9      14      12      19
TROPICAL STORM  87      77      66      46      29      38      11
HURRICANE        4      11      23      44      46      26      17
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
HUR CAT 1        4      10      19      31      24      15       6
HUR CAT 2        X       1       2       9      12       6       6
HUR CAT 3        1       1       1       3       8       4       4
HUR CAT 4        X       X       X       1       2       1       1
HUR CAT 5        X       X       X       X       X       X       X
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
FCST MAX WIND   45KT    50KT    55KT    65KT    85KT    50KT    20KT



[Ivanhater]

[ConvergenceZone]

Hmmm, looks like even though they have Texas in the cone, the NHC still believes that it will be Mexico bound. Interesting. I thought Mexico yesterday, now I'm not too sure. I'm also shocked at how long they take to make this a hurricane!....It's already a tropical storm and they don't seem to make it a hurricane until sometime on Tuesday? I mean, it's only 30mph away from a hurricane as it is. Any reason they they are being so consevative? Perhaps they mention it in their discussion. I haven't had the chance to read it yet.

[TeamPlayersBlue]

Does anyone remember the storm several years ago that went from a Tropical Storm to a Cat 3 Hurricane in like 24 hours or something like that. I remember the storm but can't remember the name. I think Alex may try his hand at some RI as it moves away from the Yucatan.
Thanks in advance,
Tim

Is it Humberto from 2007? http://en.wikipedia.org/wiki/Hurricane_Humberto_(2007)

I follow the waves in the atlantic very closely and i remember that morening it literally popped up! I was like, "um wow, that could be a hurricane pretty quickly." At the time it was barely a depression, but i remember that storm had a nice circulation, great "balance" (the eye was in the middle of the circulation and not the NW side of the storm like many young TS's in the gulf. Sure enough, that night, it made it to 90 mph. We had a beach hous in Crystal beach so we became worried but, the storm surge was minimal. Had 75 mph winds and only lost some shingles. I'm going to look for some youtube vids of the storm coming ashore. Many thought the storm had wind gusts to 115 as it made landfall!

In regards to Alex, i dont expect the same thing to happen since Humberto was in Sept., but Alex has a broad circulation and the eye is in the middle of the Low, so it can strengthen quickly

(sorry for going slightly off topic)

[LSU2001]

I think it was Humberto. I remember it was kind of a non player then all of a sudden it exploded into a cane.
Thanks a bunch I knew someone would help me out.
Tim

[thetruesms]

Hmmm, looks like even though they have Texas in the cone, the NHC still believes that it will be Mexico bound. Interesting. I thought Mexico yesterday, now I'm not too sure. I'm also shocked at how long they take to make this a hurricane!....It's already a tropical storm and they don't seem to make it a hurricane until sometime on Tuesday? I mean, it's only 30mph away from a hurricane as it is. Any reason they they are being so consevative? Perhaps they mention it in their discussion. I haven't had the chance to read it yet.

Intensity is particularly puzzling, as only the statistical intensity models bring it to hurricane strength. All of the dynamical models keep it as a tropical storm, despite the apparent good conditions for development.

[ConvergenceZone]

Thanks thetruesms
guess, we'll just have to wait and see. It is puzzling that the dynamic models only take it to a tropical storm. Perhaps they are seeing something we aren't. Just not sure what it is.

[jinftl]

Dr. Jeff Masters discussion may provide some clues as to what could hold Alex back from really bombing out:

"Re-intensification of Alex is likely once the center of Alex moves offshore, though this will initially be slow due to the current disorganized state of the storm and the relatively low total ocean heat content in the 100-mile-wide stretch of water on the west side of the Yucatan Peninsula. Once Alex moves more than 100 miles from the Yucatan, total heat content of the ocean increases substantially, and Alex will have the opportunity to intensify significantly. A longer time spent over water will give Alex more of a chance to strengthen, and it is possible Alex could intensify into a major hurricane if landfall is delayed until Thursday or Friday.

However, Alex's intensification may be limited the farther north it gets, as water vapor satellite images show plenty of dry air over Texas that might interfere with development. Wind shear might also be an issue for Alex if it pushes far enough north, and a slow-moving storm tends to pull up cold water from the depths, limiting intensification. In short, Alex has the potential to intensify into a major hurricane, but there are plenty of roadblocks that make this only a 10% probability in my estimation."

Thanks thetruesms
guess, we'll just have to wait and see. It is puzzling that the dynamic models only take it to a tropical storm. Perhaps they are seeing something we aren't. Just not sure what it is.

[AJC3]

One thing that may help with the future model runs is that I heard there was supposed to be a G-IV upper-air flight today to sample the upper air pattern across the Gulf ahead of Alex. In addition, I believe that coastal RAOB stations were tasked with taking extra observations in advance of the storm. I'm not sure if either of these occurred today, or if or when the data might be incorporated into the models.

Supplemental rawinsonde launches are supposed to start 18Z MON...

http://forecast.weather.gov/product.php ... glossary=1

[MWatkins]

Hmmm, looks like even though they have Texas in the cone, the NHC still believes that it will be Mexico bound. Interesting. I thought Mexico yesterday, now I'm not too sure. I'm also shocked at how long they take to make this a hurricane!....It's already a tropical storm and they don't seem to make it a hurricane until sometime on Tuesday? I mean, it's only 30mph away from a hurricane as it is. Any reason they they are being so consevative? Perhaps they mention it in their discussion. I haven't had the chance to read it yet.

Intensity is particularly puzzling, as only the statistical intensity models bring it to hurricane strength. All of the dynamical models keep it as a tropical storm, despite the apparent good conditions for development.

Equally as puzzling, the dynamical models (especially the GFDL) wanted to make a big-old hurricane out of Alex when it was in a way less favorable environment east of Jamaica.

Also, they (the hurricane dynamical models) seemed to overdo just about every storm last year.

Crazy how little we really know about intensity forecasting.

MW

[HurrMark]

Although it might be a close call, I still do not think this will be a US storm. The models calling for it to strike Texas show it moving northward immediately, and I think that is very dubious. While it might stair-step northwest-NNW for a while, I think a general direction near La Pesca is probably the best bet for now. I think the models showing a more northerly landfall point will shift southward as more data comes in to feed into the models.

I think this could easily be a major hurricane...would not be surprised to see RI for an extended period of time...and thus quickly ramp up.