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Jimena nears Category 5 status; 94L getting sheared

By: Dr. Jeff Masters, 9:02 PM GMT on August 31, 2009

The most powerful hurricane anywhere on the planet so far this year is Hurricane Jimena, according to data from this afternoon's hurricane hunter mission. Jimena's 155 mph winds beat out the South Pacific's Tropical Cyclone Hamish (150 mph winds) as the most powerful tropical cyclones so far this year. The Hurricane Hunters have completed their mission into Jimena, so we will have to rely on satellite estimates of Jimena's strength until Tuesday afternoon's hurricane hunter flight to see if the storm intensifies to the 160 mph threshold needed for it to become a Category 5 hurricane.

Jimena is expected to make landfall Tuesday night or Wednesday morning along the Mexico's Baja Peninsula. The hurricane is in an environment with low wind shear, 5 - 10 knots, and warm Sea Surface Temperatures (SSTs), 30°C. Shear is expected to remain low, and SSTs will decline to 28°C with a corresponding decree in total oceanic heat content between now and landfall, and these conditions should mean that Jimena will be a Category 3 or 4 hurricane at landfall. The computer models have come into better agreement with their latest 12Z runs, giving confidence that a landfall north of Cabo San Lucas will occur, and that town is now outside of the NHC cone of uncertainty. Cabo San Lucas has a 13% chance of receiving hurricane force winds, according to NHC's wind probability product. Serious flooding due to heavy rains will occur across all of the southern Baja Tuesday and Wednesday. Jimena is of similar intensity and is following a similar track to Hurricane Juliette of 2001, which brought 17.7" of rain to Cabo San Lucas. Juliette killed 7 people and caused $20 million in damage to Mexico, mostly due to flash flooding and mudslides from the heavy rains.

After Jimena makes initial landfall on Baja, it will cross over the Gulf of California and make landfall on Mainland Mexico. Depending upon how up along the coast this second landfall occurs, Arizona may receive moisture from Jimena late this week that will be capable of causing flooding rains.


Figure 1. Visible satellite image of Hurricane Jimena at 4:35 pm EDT on Monday, 8/31/09.

Invest 94L getting sheared
Tropical wave (94L) about 450 miles east of the central Lesser Antilles Islands, continues to be a threat to develop into a tropical depression. However, recent satellite wind shear analyses by NOAA/Colorado State University show that wind shear has increased throughout the day over 94L, and is now near 20 knots, which is marginal for development. Satellite shear analyses from the University of Wisconsin show about 10 - 20 knots of shear, and it is apparent from satellite imagery that shear is causing some disruption to the west side of 94L. Visible satellite imagery show that 94L does not have a surface circulation center, and the storm has not significantly increased in organization this afternoon.

The forecast for 94L
Wind shear as diagnosed by the SHIPS model currently shows a low amount of shear, 5 - 10 knots, and this is not correct, so this model's forecast of low shear over 94L for the next five days cannot be trusted. The latest set of 12Z model runs are more restrained in developing 94L, and are depicting higher levels of shear will be affecting 94L over the next three days. SSTs will be warm, in the 28 - 29°C range, and dry air should have only a minor inhibiting effect, but the high shear may delay 94L from developing into a tropical depression for several days. The HWRF makes 94L into a strong tropical storm 5 days from now, but the GFDL and GFS models do not develop 94L at all. The ECMWF and NOGAPS models predict that development of 94L will not occur until five or so days from now, in a region between the Bahama Islands and Bermuda. NHC continues to give 94L a high (greater than 50% chance) of developing into a tropical depression by Wednesday. This probability may need to get scaled back to moderate (30 - 50% chance) if the high shear continues into tomorrow.

My next post will be Tuesday morning.

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

Quoting justalurker:
how many of you are posting at work? without anyone knowing?




lol
2502. P451
00CMC




06GFS



00NGP




06HWRF

Have we heard from Oz yet this AM?
HHunter as soon as it gets out though, should be able to develop.
94L is just a wave at this point. Shear is tearing up the W side of it. It's possible recon might abort the mission today if it doesn't look any better than this. The wave that came off africa has a better chance of forming into a decent storm than 94L. The 0Z GFS thinks a anticyclone will build over it by later this evening. That's it's only chance. GFS also says a busy September is coming. I think we will see a few later on down the road that will actually be impressive storms that make it closer to the US. Conditions might be better at that point. Right now too much shear from strong troughs ULLs etc.
Quoting hurricanehanna:
Have we heard from Oz yet this AM?
He is out storm chasing and trying to catch a ride with the AP. :)
2507. RJT185
Quoting justalurker:
how many of you are posting at work? without anyone knowing?


lol
2508. fmbill
NWS Melbourne...

SUN-TUE...DLM RIDGE INITIALLY IN PLACE BEGINS TO WEAKEN ACROSS FL
AND THE WRN ATLC AS MINOR SHORT WAVE ENERGY PUSHES EWD AND OFFSHORE
THE ERN CONUS. AM HAVING PROBLEMS WITH THE GFS SOLN BRINGING A WAVE
ALL THE WAY WWD INTO THE BAHAMAS. MUCH LIKE THE CASE WAS WITH BILL
...PREFER THE MORE LKLY ECM SOLN...AS THERE WILL LKLY BE MORE THAN
ENOUGH EROSION OF THE WRN PORTION OF THE BERMUDA RIDGE TO ALLOW THE
CTRL ATLC SYSTEM TO TURN NWD WELL EAST OF FL.
NET RESULT IS A WEAK
ONSHORE FLOW/PRES PATTERN WITH SUFFICIENT MOISTURE FOR NEAR NORMAL
(CLIMO) POPS IN THE 30-40 PCT RANGE.
Quoting hurricanehanna:
Have we heard from Oz yet this AM?


His live webcam is running
Quoting hurricanehanna:
Have we heard from Oz yet this AM?


He posted about 15-20 minutes ago. Said he might get to ride with the AP crew.
If 94L is moving wnw, why doe the NWS place the 12GMT coordinates at 15.9 and 57.1 (lower than the previous coordinates). I'm really quite new to this, but I just can't understand these discrepencies.
Quoting justalurker:
how many of you are posting at work? without anyone knowing?


I post from the office but everyone knows about my weather "obsessions" so they encourage it and rely on me for reports on potentially threatening weather for our region. However, if a hurricane threatens our area, I give folks a prepatory heads up but then turn them over to NHC for the official take (to avoid liability)....... :)
Quoting conchygirl:
He is out storm chasing and trying to catch a ride with the AP. :)

Cool! I was watching some footage this AM on ABC and I kept waiting to see Oz in his full gear!
Quoting Tazmanian:
evere one love StormW



whats see if evere one loves Taz
We love you both!
Quoting P451:
00CMC




06GFS



00NGP




06HWRF



hey p,

for what i've learned here so far based on these models..

CMC=aggresive
NGP=?
GFS= medium tracking
HWRF=intensity

please correct if i am wrong..your help is appreciated.

Looking at those track forecast animations, it seems the ridge is not expected to steer 94L westwards. Instead, the storm pushes its way northwards through the ridge.

Quoting weathermanwannabe:


I post from the office but everyone knows about my weather "obsessions" so they encourage it and rely on me for reports on potentially threatening weather for our region. However, if a hurricane threatens our area, I give folks a prepatory heads up but then turn them over to NHC for the official take (to avoid liability)....... :)

They call me the weatherwoman over here. Anytime something comes up they start asking me questions via e-mail. I just tell them to duck!
2518. Grothar
Quoting DestinJeff:


right here Link


Thanks DestinJeff. Got it! I feel like a real pro.. My wife said I am getting a 'tude now. Strutting my little graphics like I know what they mean.
Quoting weathermanwannabe:


I post from the office but everyone knows about my weather "obsessions" so they encourage it and rely on me for reports on potentially threatening weather for our region. However, if a hurricane threatens our area, I give folks a prepatory heads up but then turn them over to NHC for the official take (to avoid liability)....... :)


do they pay extra for that info?
Westward ho....
2521. MahFL
Lol, the shear always "relaxes tomorrow" never today......
2522. IKE
I can just about see the exposed coc of 94L. Give it an hour and we should be able to give exact coordinates on it.
2525. quante
94L is going to have to survive some significant shear.

If it does, track is all about the ridge and how strong and how far West it is, when it arrives.
Lol; yeah, I'm the "offical" weatherman for the office, and no, I don't get paid extra for it..........I should though cause all the e-mail I get and reply to (from different areas of the State) during H-season is another full-time job!
2527. Seastep
Quoting IKE:
I can just about the see the exposed coc of 94L. Give it an hour and we should be able to give exacts coordinates on it.


Yeah, you can really see it on RGB. Looks closed now.
the new quickscat is showing winds of up to 50mph with invest 94L.... is this correct?
Quoting DestinJeff:


BAM suite not on the Trough Train


It probably wont get strong enought to feel the trough.
I see 94L has 35 mph winds. I guess we are just missing a closed low?
Quoting weathermanwannabe:
Lol; yeah, I'm the "offical" weatherman for the office, and no, I don't get paid extra for it..........I should though cause all the e-mail I get and reply to (from different areas of the State) during H-season is another full-time job!


multitasking..key to success!!
94L seems to be going through a shredder
StormW is back ............ YEAH!!!!!!
2534. KRL
Nice shot of 94L (click to enlarge)

Quoting IKE:
I can just about see the exposed coc of 94L. Give it an hour and we should be able to give exact coordinates on it.


I can also see what appears to be the weak surface vortex near 16.5N 56.8W.
94L is reminding me so much of Ana and Danny boy. I think I can...I think I can hehe
2537. IKE
Quoting Seastep:


Yeah, you can really see it on RGB. Looks closed now.


Sorry for my bad English. I edited my post.

2538. fmbill
Quoting weathermanwannabe:
Lol; yeah, I'm the "offical" weatherman for the office, and no, I don't get paid extra for it..........I should though cause all the e-mail I get and reply to (from different areas of the State) during H-season is another full-time job!


I always enjoy the calls from management wanting to play golf. "Is it going to rain this afternoon?"

"Hmmm...let me see, it's summer, it's Florida, and you want to play this afternoon..." LOL!!!
Location, movement, and strength are going to get it hung up in the next ridge. The GOM will be where it could be a true major problem.
Quoting IKE:
I can just about the see the exposed coc of 94L. Give it an hour and we should be able to give exacts coordinates on it.


You can see it on RGB Loop.16.6N and 57.2W
Quoting justalurker:


multitasking..key to success!!


Back to the weather but yeah; I have my work computer on my desk and a few laptops hooked up with the satt loops and blog off to the side........

So, how about the short term steering for 94L? (this one is not going to get sheared away as suggested by some folks on here)....Gotta be a bit nervous in the Leewards I would think.
Quoting yonzabam:
Looking at those track forecast animations, it seems the ridge is not expected to steer 94L westwards. Instead, the storm pushes its way northwards through the ridge.



Look again
LOL if a CAT 5 hurricane got just a bit asymmetrical be sure that IKE will tell you about it LMAO



94L had a beautiful signature on TPW imagery, but now it's looking a little ragged.

Edit: Notice the huge chunk of moisture it casts off toward the SW at the end of the loop...
Quoting weathermanwannabe:


Back to the weather but yeah; I have my work computer on my desk and a few laptops hooked up with the satt loops and blog off to the side........

So, how about the short term steering for 94L? (this one is not going to get sheared away as suggested by some folks on here)....Gotta be a bit nervous in the Leewards I would think.


Our met office has no warnings or watches up yet... hoping most people are aware of what's next to us.
the partiall exposed COC of 94L is still open on the sw and is moving west
2547. P451
Quoting justalurker:


hey p,

for what i've learned here so far based on these models..

CMC=aggresive
NGP=?
GFS= medium tracking
HWRF=intensity

please correct if i am wrong..your help is appreciated.



Can't help ya there I'm not an expert on the models.

I will say the GFS went from developing every cloud it saw into a TS earlier this year to not developing a number of systems.

The CMC is always very aggressive with intensity.

That's about all I know.
2548. Parkay
Does 94L finally have a surface circulation? Or is that some other feature in the top left corner?

2549. stormno
mobile girl this system will encounter anothe rstrong 700mb trough and will not be a problem for anyone except the fish...so i will tell you now this will never make the gulf of mexico...its surrounded by a stong force shield...gulf is clear from this system..Stormno
Quoting weathermanwannabe:


Back to the weather but yeah; I have my work computer on my desk and a few laptops hooked up with the satt loops and blog off to the side........

So, how about the short term steering for 94L? (this one is not going to get sheared away as suggested by some folks on here)....Gotta be a bit nervous in the Leewards I would think.


agree back to the tropics, just trying to break the stress a little..no prob..i am not an expert here, but lets hope for the best for everyone here who could be effected by 94L.
2552. Seastep
Quoting Parkay:
Does 94L finally have a surface circulation? Or is that some other feature in the top left corner?



That's the old llc. Developing a new one just on the W edge of the convection.
2553. IKE
Quoting Elena85Vet:


You can see it on RGB Loop.16.6N and 57.2W


I see it.
2554. Seastep
IKE - Is recon going out early since you said an hour?
Quoting P451:
00CMC

>

I'll believe this when i see it.
Invest 94L in 90 hours
944.58hPa, Max winds 131.173kts

Quoting P451:


Can't help ya there I'm not an expert on the models.

I will say the GFS went from developing every cloud it saw into a TS earlier this year to not developing a number of systems.

The CMC is always very aggressive with intensity.

That's about all I know.


I believe Dr. M noted on an earlier blog the cmc has been the most accurite in terms of direction so far this year...
Quoting P451:


Can't help ya there I'm not an expert on the models.

I will say the GFS went from developing every cloud it saw into a TS earlier this year to not developing a number of systems.

The CMC is always very aggressive with intensity.

That's about all I know.


alright maybe someone else would like to chime in..
2558. ssmate
Quoting MahFL:
Lol, the shear always "relaxes tomorrow" never today......


lol. Funny how that works.
One of the first rules of following tropical cyclone formation is... focus on the surface flow, not the pretty blobs. Tropical cyclones are surface based systems. You can have the most intense-looking, vigorously spinning blob you've ever seen, but if there is no surface organization there is no tropical cyclone... just an impressive MCS. 94L's organization continues to be poor.
2560. IKE
Quoting BurnedAfterPosting:
LOL if a CAT 5 hurricane got just a bit asymmetrical be sure that IKE will tell you about it LMAO



Had to throw in a jab, didn't ya?
2561. tbrett
Quoting JadeInAntigua:


Our met office has no warnings or watches up yet... hoping most people are aware of what's next to us.

They finally mentioned it this morning on the radio, but said it was nothing to worry about. We would only get 20mph winds.
Quoting AussieStorm:

I'll believe this when i see it.
Invest 94L in 90 hours
944.58hPa, Max winds 131.173kts



HWRF just won't give it up...
Quoting JadeInAntigua:


Our met office has no warnings or watches up yet... hoping most people are aware of what's next to us.


Hope that your media has at least alerted folks to the potential right on your doorstep....Won't have too much time to make preparations if it starts heading your way; TD or not, a strong tropical wave with copious amounts of rain and gusts is no picnic.
The African wave looks better then 94L right now lol. I think the High will steer it west too. We have to watch that one.
2565. IKE
Quoting Seastep:
IKE - Are the HH going out early since you said an hour?


No...I was talking about the COC being completely exposed to where we can all see where the center is at.

Not sure on recon.
2566. rxse7en
Quoting SavannahStorm:


94L had a beautiful signature on TPW imagery, but now it's looking a little ragged.

Edit: Notice the huge chunk of moisture it casts off toward the SW at the end of the loop...
Love that image. That trough looks to be settling in much closer to the CONUS.
2567. stormno
it looks like in the last 3 frames i looked at 94L is once again in a weakening stage...shear is starting to work its magice on 94L ...its going to be a rough road to hold to even keep it together...i see no problems with this system...Stormno
If the 06z HWRF is to be believed, we will have a Cat 5 headed this way by Saturday.....
This is very odd, despite that Jimena is really near from Cabo San Lucas all the things are very normal, it just rained a little bit, winds are very calm, What happens? I've been in other hurricanes also in Tropical Storms that are farther than Jimena and the winds are stronger and the rain havyer... The local is getting tired to wait and they think that all is gone U_U. Maybe Jimena is not that bigger as it was days ago... What do u think.

Right now, light rain.
Quoting nishinigami:


His live webcam is running



Does anyone have a link to OZ webcam?
Quoting IKE:


No...I was talking about the COC being completely exposed to where we can all see where the center is at.

Not sure on recon.


They were supposed to go out at 2pm according to a post from yesterday. Don't know if that's changed...
GOES-12 WV Loop

I have to give 94L some credit- it's got a helluva exhaust system. Notice the high cirrus racing away from the convection in all directions. In fact- a little too good on the west side- it's being sheared by the anticyclone itself.

However, the ULL to the NNW that is enhancing that flow is lifting away. Shear will slowly diminish on that side.
George;

Jimena is a small system, you are getting the outer parts of the storm, it will get worse

Keep us all posted on what is going on there
Quoting tbrett:

They finally mentioned it this morning on the radio, but said it was nothing to worry about. We would only get 20mph winds.


Glad to hear Montserrat is on top of things. Whether something tracks our way and intensifies or not, we should all at least be aware of the presence of something in case we do find ourselves making last minute preparations.
2575. P451
NEW BLOG


NEW BLOG


NEW BLOG


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New blog
new blog
NEW BLOG
Quoting stormno:
it looks like in the last 3 frames i looked at 94L is once again in a weakening stage...shear is starting to work its magice on 94L ...its going to be a rough road to hold to even keep it together...i see no problems with this system...Stormno

Nobody saw problems with tropical storm Katrina either did they?
Quoting stormno:
mobile girl this system will encounter anothe rstrong 700mb trough and will not be a problem for anyone except the fish...so i will tell you now this will never make the gulf of mexico...its surrounded by a stong force shield...gulf is clear from this system..Stormno


Here we go. stormno come on, the NHC said intrests in the leeward islands, virgin Islands, the US and Puerto Rico should monitor the progress of this system. If they knew it would turn out to sea, then they wouldn't say US to begin with and same with the virgin islands. The NHC will decide where it will go once it develops. The models are all over the place and the majority has it hitting the US. I know it will definitely not go into the GOM but it could be an east coast storm.
Quoting hurricanehanna:
Have we heard from Oz yet this AM?



Oz has the live webcam up @ Xtremehurricanes.com
Quoting weathermanwannabe:


Hope that your media has at least alerted folks to the potential right on your doorstep....Won't have too much time to make preparations if it starts heading your way; TD or not, a strong tropical wave with copious amounts of rain and gusts is no picnic.


Yeah I agree. Unfortunately, sometimes people don't take these systems as seriously until it's at least gotten a name. Even then... Ana crossed us and was barely noticeable so I think some may have let their guards down considering this is not yet a depression.
For all the Florida and Gulf of Mexico wishcasters, take a look at Africa at the end of this GFS run. Kind of scary hopefully it doesnt pan out.



Threat's ahead?
2584. tramp96
Quoting bingcrosby:
If the 06z HWRF is to be believed, we will have a Cat 5 headed this way by Saturday.....


I'm assuming the 1024 mb over the ne states is a ridge
where did everyone go?
2586. Hhunter
94L is not fighting shear as much as dry air folks..when it moistens the environment enough it will take off..
Quoting AussieStorm:

I'll believe this when i see it.
Invest 94L in 90 hours
944.58hPa, Max winds 131.173kts



That is too far fethced. Models have not been to accurate in intensity this year I would take them all and get a mean intensity value and go with that and give it a 30% change of it happening