92L Poised to Develop in Gulf of Mexico; Erin Struggling in Far Eastern Atlantic

By: Dr. Jeff Masters , 2:09 PM GMT on August 16, 2013

Tropical wave 92L crossed over Mexico's Yucatan Peninsula overnight, and the center of the disturbance is now located in the Gulf of Mexico along the west coast of the Yucatan Peninsula. Satellite loops show that 92L has a well-developed surface circulation, but there are no heavy thunderstorms near the center. A moderate-sized region of heavy thunderstorms does lie to the northeast and east of the center, over Cancun, Cozumel, and southwards to Belize. An upper-level low pressure system over the Gulf of Mexico is pumping dry air into 92L, slowing development. Wind shear is a moderate 10 - 20 knots over the the wave, which should allow slow development today. The hurricane hunter flight scheduled for today has been cancelled.


Figure 1. MODIS satellite image of 92L taken at 1:30 pm EDT Friday August 16, 2013. Image credit: NASA.

Forecast for 92L
The 12Z Friday SHIPS model forecast predicts that 92L will remain in an area of low to moderate wind shear through Saturday, and ocean temperatures will be a favorable 29 - 30°C. The topography of the Southern Gulf of Mexico's Bay of Campeche can aid in getting a storm spinning more readily, as well. Given these favorable conditions for intensification, 92L should be able to become a tropical depression by Saturday, and a tropical storm by Sunday. A trough of low pressure over the northern Gulf of Mexico will dip down by Sunday over the Central Gulf of Mexico, increasing the wind shear to a high 20 - 30 knots just to the north of 92L. This trough may also be able to pull the storm northwestwards to a landfall in Texas on Monday or Tuesday, as the 00Z Friday runs of UKMET and NAVGEM model predict. If 92L does follow this more northwesterly path, intensification into a strong tropical storm would be difficult, due to the high wind shear. An alternate scenario is presented by our two top-performing models, the European and GFS. They predict that 92L will take a nearly due west track, resulting in a landfall south of Tampico, Mexico on Monday. The storm would have more of an opportunity to strengthen in this scenario, since wind shear would be lower. Either scenario is reasonable, and residents of the Mexican and Texas Gulf Coast should anticipate the possibility of a tropical storm hitting the coast as early as Sunday night. Regardless of 92L's track, a flow of moist tropical air along the storm's eastern flank will form an atmospheric river of moisture that will bring a wide swath of 4+ inches of rain to the Gulf Coast from Louisiana to the Florida Panhandle over the next few days. In their 8 am EDT Wednesday Tropical Weather Outlook, NHC gave 92L a 50% of developing by Sunday, and a 60% chance of developing by Wednesday. I put these odds higher, at 70% and 80%, respectively.


Figure 2. MODIS satellite image of Tropical Depression Erin taken at 10:30 am EDT Friday August 16, 2013. At the time, Erin had maximum sustained winds of 35 mph. Image credit: NASA.

Tropical Storm Erin
Tropical Storm Erin is over the far Eastern Atlantic off the coast of Africa, and continues west-northwest at 15 mph. Erin is small and weak and has lost nearly all of its heavy thunderstorms, as seen on satellite loops. This is probably due, in part, to the fact the storm is over waters of 25.5 - 26°C, which is a marginal temperature for tropical cyclones. Erin is also having trouble with dry air from the Saharan Air Layer (SAL), and the storm's west-northwest motion is beginning to cut Erin off from a moist source of air to its south--the semi-permanent band of tropical thunderstorms called the ITCZ (Inter-Tropical Convergence Zone.) The latest 00Z runs of the major global computer models, except for the GFS, call for Erin to dissipate by early next week. Given Erin's struggles today, I expect the storm will be dead by Sunday.

Jeff Masters


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1441 - 1391

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50Blog Index

1441. Levi32
Quoting 1436. Drakoen:
Interestingly enough, the GFS runs have featured a split in the 850mb vorticity with the poleward vorticity becoming more dominant as the vorticity shear takes place due to the deep layered trough advecting down the Mississippi River Valley.


No doubt 92L's vorticity will stretch towards the central gulf coast, but the lowest pressures seem likely to be left behind, even if a weak trough splits away to the north. The GFS has already displayed gross feedback errors with this system. It was the GFS which originally split away the northern part of the wave and took it through the Yucatan channel into Florida. That never happened. It's been playing catchup with reality ever since.
Member Since: Posts: Comments:
Quoting 1424. CybrTeddy:
For any of you astronomy geeks like myself, get your telescopes out and find this supernova that has been sighted in the night sky.


If didn't have a cloud layer! Missed the meteor shower too...usually miss everything...clear nights time themselves to nothing extra, will be a boring 3/4 Moon, never nice crescent or full ones or eclipses...never when meteor showers or lower latittude N Lights etc! LOL
Member Since: Posts: Comments:
1439. Patrap
I usually dont post the ensemble runs here, as I like to keep my ACE in me pocket
Member Since: December 31, 1969 Posts: Comments:
1438. sar2401
Quoting GTstormChaserCaleb:
2 GFS ensemble members are showing an Alabama landfall, interesting, and they initialized the area where everyone seems to be looking at tonight.


The GFS has been hung up on an Alabama landfall for almost every low even close to the Gulf this season. Between the GFS and CMC, they seem intent on having something hit my house this year. :-) I can reasonably see a possible landfall, assuming 92L ever get organized into an actual storm-like feature, from the mouth of the Mississippi to north of Veracruz, but Alabama seems to a complete fantasy.
Member Since: Posts: Comments:
so 2 GFS  Ensembles and 1 ATCF model means a MS landfall is possible? The system has jogged SW the past 6 hours, and there is almost nothing that could turn it NE in that way.
Quoting 1433. GTstormChaserCaleb:
This is what I'm talking about.




Member Since: Posts: Comments:
1436. Drakoen
Interestingly enough, the GFS runs have featured a split in the 850mb vorticity with the poleward vorticity becoming more dominant as the vorticity shear takes place due to the deep layered trough advecting down the Mississippi River Valley.
Member Since: Posts: Comments:
Quoting 1430. JLPR2:


Most likely due to the lack of convection.


Well, looks like its just a matter of time... the bad news is that its located S and could be dangerous...


Member Since: Posts: Comments:

NHC From 8 PM
...TROPICAL WAVES...
A TROPICAL WAVE EXTENDS AN AXIS FROM 21N51W TO 10N52W AND MOVES WESTWARD NEAR 15-20 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOW THE WAVE CONTINUE EMBEDDED WITHIN A MODERATE MOIST ENVIRONMENT AT THE LOWER LEVELS. HOWEVER...METEOSAT SATELLITE IMAGERY SHOW SAHARAN DUST AND DRY AIR SPREADING OVER THE WAVE ENVIRONMENT
WHICH IS SUPPRESSING CONVECTION
Member Since: Posts: Comments:
Quoting 1431. dfwstormwatch:
what are you talking about?

This is what I'm talking about.



Member Since: December 31, 1969 Posts: Comments:
Quoting 1424. CybrTeddy:
For any of you astronomy geeks like myself, get your telescopes out and find this supernova that has been sighted in the night sky.


So cool... Unfortunately i am in the Mississippi gulf coast and we have been under overcast pretty much for ever. Lol Biloxi Mississippi the Seattle of the south...
Member Since: Posts: Comments:
what are you talking about?
Quoting 1428. GTstormChaserCaleb:
92L is a carbon copy of Debby last year, the GFS model stubbornly pointed to FL. while the rest pointed to Texas. A landfall on the Mississippi Gulf Coast can't be ruled out now.

Member Since: Posts: Comments:
1430. JLPR2
Quoting 1423. sunlinepr:
Why don't we have this invest?



Most likely due to the lack of convection.

Though at least it was acknowledged in the last surface map.

Member Since: December 31, 1969 Posts: Comments:
1429. Grothar
Quoting 1414. TropicalAnalystwx13:
It's on crack.



What is so unusual about that?
Member Since: Posts: Comments:
92L is a carbon copy of Debby last year, the GFS model stubbornly pointed to FL. while the rest pointed to Texas. A landfall on the Mississippi Gulf Coast can't be ruled out now.
Member Since: December 31, 1969 Posts: Comments:
Quoting 1418. Grothar:
I don't know if this helps, but the Super Computer just analyzed Erin's track.



Thanks Gro... that makes everything so much clear now...
Member Since: Posts: Comments:
Quoting 1423. sunlinepr:
Why don't we have this invest?



It's still straddling the ITCZ.
Member Since: Posts: Comments:
FWIW, Pewa is pronounced "PEH-vah" and is a traditional Hawaiian butterfly patch.
Member Since: Posts: Comments:
Why don't we have this invest?

Member Since: Posts: Comments:
Quoting 1418. Grothar:
I don't know if this helps, but the Super Computer just analyzed Erin's track.



Ah, at last. It is getting a better handle on it now.
Member Since: Posts: Comments:

I hope that 92L will take the Texas route inland.
Member Since: Posts: Comments:
Quoting 1321. Levi32:


I do apologize for being short. I have very low tolerance for claims of weather events "never before seen by man." Such claims are a present-day epidemic.


I know what you mean, Levi. I can empathize with you on this. I am having the same problem of showing tolerance for claims that anthropogenic greenhouse gases will somehow defy The Laws of Physics, Chemistry and Thermodynamics and not have an impact on our climate. How does that even happen?
Member Since: Posts: Comments:
1419. ncstorm
Quoting 1418. Grothar:
I don't know if this helps, but the Super Computer just analyzed Erin's track.



LOL!!!!
Member Since: December 31, 1969 Posts: Comments:
1418. Grothar
I don't know if this helps, but the Super Computer just analyzed Erin's track.

Member Since: Posts: Comments:
Anyone thinks this season is verrrryyyyy eccentric.
Member Since: Posts: Comments:
1416. Patrap
No Tequila fer yous, 92L
Member Since: December 31, 1969 Posts: Comments:
1415. Drakoen
He who laughs last laughs best. Mexico right?........Churn baby churn

Member Since: Posts: Comments:
It's on crack.

Member Since: Posts: Comments:
Question for the blog: What makes the shortwave imagery blue and what makes it green?
Member Since: December 31, 1969 Posts: Comments:
1412. Patrap
Hmmm,if memory serves me, I think it was Aug 15th, Comment 1616,,I discussed, don't write off the ULL.

But I digest.

OOOfh, scuse me
Member Since: December 31, 1969 Posts: Comments:
Quoting 1186. moonlightcowboy:



No, they did not merge. They may have been inhibited, sheared, dissipated or otherwise positively influenced, ventilated and made stronger, but they most assuredly did NOT become a two-into-one system.
Quoting 1193. KoritheMan:
Lee deepened baroclinically; the central pressure was dropping even while the center itself was devoid of convection.

mlc, sorry, but that's the very definition of a surface low collocating/merging with an upper low. It's also one of the defining characteristics of subtropical cyclones.
Quoting 1193. KoritheMan:
Lee deepened baroclinically; the central pressure was dropping even while the center itself was devoid of convection.

mlc, sorry, but that's the very definition of a surface low collocating/merging with an upper low. It's also one of the defining characteristics of subtropical cyclones.
Quoting 1186. moonlightcowboy:



No, they did not merge. They may have been inhibited, sheared, dissipated or otherwise positively influenced, ventilated and made stronger, but they most assuredly did NOT become a two-into-one system.
Quoting 1193. KoritheMan:
Lee deepened baroclinically; the central pressure was dropping even while the center itself was devoid of convection.

mlc, sorry, but that's the very definition of a surface low collocating/merging with an upper low. It's also one of the defining characteristics of subtropical cyclones.
I bet Moonlight still wont believe you !! There is a point where you just say, I Give Up !!!!!!
Member Since: Posts: Comments:
Quoting 1398. will40:


is that close to egotastic?

monomaniacal perhaps
Member Since: Posts: Comments:
Quoting 1382. Grothar:


Well, the only thing I feel badly about is when I tried to point out the ULL to some people last night, coming into the picture, and I was practically run off the blog. So I just left. I was really hurt. (")


Seriously?!

It had already been affecting it anyway, pulling so much moisture out of it towards FL. Not sure how anyone would have not seen it was already having an affect.
Member Since: Posts: Comments:
1408. Patrap
Quoting 1407. Grothar:



Thanks, Teddy. And I can't think of anyone more vertically stacked.


Oh I can.

Reow'

Woo Hoo
Member Since: December 31, 1969 Posts: Comments:
1407. Grothar
Quoting 1396. CybrTeddy:


You're such an asymmetric blogger Gro. :)



Thanks, Teddy. And I can't think of anyone more vertically stacked.
Member Since: Posts: Comments:
1406. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #9
TROPICAL DEPRESSION 13
9:00 AM JST August 17 2013
===================================

SUBJECT: Tropical Depression South Of Okinawa

At 0:00 AM UTC, Tropical Depression (1000 hPa) located at 21.3N 124.3E has 10 minute sustained winds of 30 knots. The depression is reported as moving south southeast slowly.

Dvorak Intensity: T2.0

Forecast and Intensity
=========================
24 HRS: 21.6N 126.9E - 35 knots (CAT 1/Tropical Storm) South Of Okinawa
Member Since: Posts: Comments:
Quoting 1387. Grothar:
Sometimes this blog is so atypical.


As atypical as this tropical season....
Member Since: Posts: Comments:
1404. guygee


Dry air wrapping into the center of the ULL is giving 92L a faux "eye". The actual surface circulation is still southwest of the ULL,



Question: In lieu of any other strong steering force, will the "Campeche effect" tend to pull the surface circulation farther to the WSW?
Member Since: Posts: Comments:
Member Since: December 31, 1969 Posts: Comments:
1402. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #3
TROPICAL DEPRESSION 14
9:00 AM JST August 17 2013
===================================

SUBJECT: Tropical Depression West Of Minami Daito

At 0:00 AM UTC, Tropical Depression (1000 hPa) located at 25.9N 130.3E has 10 minute sustained winds of 30 knots. The depression is reported as moving northwest at 9 knots.

Dvorak Intensity: T2.0

Forecast and Intensity
=========================
24 HRS: 27.3N 127.0E - 35 knots (CAT 1/Tropical Storm) Near Okinawa
Member Since: Posts: Comments:
K, GFDL.

Member Since: Posts: Comments:
Quoting 1385. Tropicsweatherpr:


We also have to see if Erin leaves a big weakness for this system or the ridge fills behind Erin.


I don't think Erin is strong enough to create a huge gaping hole in the ridge. Also, the extratropical cyclone that's likely to recurve it will probably be too far north; breaks created and enhanced by tropical cyclones are typically maximized via interaction with a mid-latitude cyclone.
Member Since: Posts: Comments:
1398. will40
Quoting 1387. Grothar:
Sometimes this blog is so atypical.


is that close to egotastic?
Member Since: Posts: Comments:
Quoting 1389. CybrTeddy:


I am grateful of all corrections, I make moronic mistakes sometimes and I feel it should be everyone's goal to point them out to me when I do.


LOL - well, you've certainly come to the right place ;).
Member Since: Posts: Comments:
Quoting 1387. Grothar:
Sometimes this blog is so atypical.


You're such an asymmetric blogger Gro. :)
Member Since: December 31, 1969 Posts: Comments:
1395. Patrap
Thank you
Member Since: December 31, 1969 Posts: Comments:
1394. sar2401
Quoting Skyepony:


The models initialized horrible the second day plus it was overland.. that is why they did pretty horrible that day by these calculations (overall maybe throw that day out but look hard at the few that got it).. They take the model runs & get the error distance after tracking the invest..which you know the NHC gives a location of several times a day. Yes there hasn't been the greatest tightest low to track but I've watched these storm & model verification numbers since back when these calculations came out of UCF..the models that are doing better with it than the rest will continue to out preform if the storm wraps up & intensifies. Here is the whole list. I just posted a handful. Over all the models haven't done well with 92L so far which is an important piece of info those numbers are also pointing out.

Skye, I have no idea what parameters you're using from this site, but I just ran it based on 48 hours (since that's the maximum time for the model runs) and changed the average to "Entire Storm", and the CMC is off by 106 nautical miles at 48 hours. The NAM, surprisingly, is only off by 72 miles. The BAMS, which should be a good performer in these circumstances, is off by 45 miles. This is what the models look like when I ran them.
Regardless of the actual figures, a model run is only good if it predicts the entire track, from initialization to landfall, within a reasonable margin of error. 92L hasn't made landfall, so we really don't know the ultimate success of any model. Dorian never made landfall. It also keeled over, regenerated, and keeled over again. How many models picked that up? Simply because a model happened to have an end point near where it finally keeled over for the last time isn't the sign of good model. If the model showed landfall in Florida or the Bahamas and it didn't happen, the model track failed. It's kind of like me making a model track of driving from Alabama to Los Angeles. If I detoured to Canada and then drove back south to get to L.A., was my model track still good because I ended up in the right place?

Member Since: Posts: Comments:
1393. Levi32
Quoting 1388. Drakoen:


Well look at you now. Lmao. I'll reserve my comments on that as beyond the scope of this blog. :)


Yes. Sass can be learned lol, and I learned from the best.
Member Since: Posts: Comments:
It will be interesting to see if the larger circulation draws some of the convection forming overland into itself.
Member Since: Posts: Comments:
What's an "a" among friends?
Member Since: Posts: Comments:

Viewing: 1441 - 1391

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50Blog Index

Top of Page

Category 6™

About

Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather