Tropical Storm Erika's future highly uncertain

By: Dr. Jeff Masters , 2:21 PM GMT on September 02, 2009

Share this Blog
2
+

The tropical wave we were calling Invest 94 finally decided to stop dawdling and become Tropical Storm Erika yesterday. However, Erika seems intent upon keeping us guessing about its intentions, as the storm's future track and intensity remain highly uncertain. After a modest burst of intensification to a 60 mph tropical storm last night, Erika has become quite disorganized this morning. The Hurricane Hunters found multiple swirling centers inside Erika early this morning, and the main center took a jump to the southwest to relocate itself under a batch of intense thunderstorms. The exact location and path of Erika remain uncertain at this point, and it is possible the storm will have another center relocation later today. Wind shear analyses from the University of Wisconsin diagnose a moderate 10 - 15 knots of shear over Erika, a decrease from yesterday. SSTs are warm, 29°C. Why, then, is Erika so disorganized? The trouble with the various wind shear analyses we use is that they take a crude average of winds over a thick layer to arrive at an average shear, and this large-scale average shear does not capture thin layers of shear that can dramatically affect a tropical cyclone. Upper air data from Guadeloupe and Saint Martin from last night show a complicated shear pattern in Erika's region, with 30 knot winds out of the south to southwest at 200 mb height, nearly calm winds between 300 - 500 mb, and northeasterly winds of 10 - 20 knots from the surface to 500 mb. Some extremely dry air with humidities near 10% was present in a thin layer near 600 mb on the Guadeloupe sounding, so dry air from the Saharan Air Layer is probably being injected by a northeasterly jet of wind into the core of Erika. The shear of 30 knots at the top of the storm is ripping away the heat and moisture Erika's thunderstorms are lifting there, and the result of the shear and dry air is a very disorganized tropical storm.

Erika is embedded in a weak steering current pattern, and the future track of the storm will depend greatly upon how strong the storm gets over the next few days. A stronger Erika will extend higher into the atmosphere and be steered more to the northwest by upper-level winds. A weaker Erika will be steered more by the low-level winds, which will keep the storm on a more westerly track. Given the complicated nature of the wind shear pattern in the region, it is difficult to forecast how strong Erika will get. Virtually anything can happen over the next five days, from dissipation (as forecast by the ECMWF model) to intensification to a Category 3 hurricane (as forecast by the HWRF model). Large-scale wind shear is expected to increase to 20 - 25 knots between 3 - 4 days from now, so Erika will have to deal with an increasing amount of adversity. The storm is a long-term threat to the Bahamas and U.S. East Coast, particularly if the storm stays weak over the next three days. Potential landfall solutions from the models range from Florida on Tuesday (GFS model) to North Carolina on Wednesday (Canadian model).


Figure 1. Morning image of Tropical Storm Erika, showing a false center over Guadaloupe--one of several surface swirls the Hurricane Hunters found in the storm.

Elsewhere in the tropics
The tropical wave off the coast of Africa we were watching on NHC's Tropical Weather Outlook as having a low chance of developing into a tropical depression has been done in by the dry air of the Sahara, and is no longer a threat to develop. A large and well-organized tropical wave will emerge from the coast of Africa on Thursday, and several of the models develop this low into a tropical depression by early next week. The remains of an old cold front off the coast of North Carolina could serve as a breeding ground for some tropical development Friday or Saturday, but anything that forms in this region would get swept quickly northeastward into New England by Sunday without enough time to become a tropical depression.

Hurricane Jimena nears Baja
Hurricane Jimena has steadily weakened over the past day, and is now down to a Category 2 hurricane with 105 mph winds. The storm should continue to steadily weaken over the next 24 hours as the waters under the hurricane cool from 28°C to 27°C. Jimena is battering a relatively unpopulated stretch of coast, and largely spared the tourist mecca on the southern tip of Baja. It now appears unlikely that moisture from Jimena will reach the Southwestern U.S., and the hurricane appears poised to stall out over Baja and die five days from now.


Figure 2. Hurricane Jimena on Tuesday, Sep. 1, 2009, as seen by NASA's MODIS instrument. Image credit: NASA Earth Observatory.

Baja's hurricane history
The most powerful hurricane on record to hit the west coast of Baja occurred last year, when Hurricane Norbert made landfall on the central Baja coast with sustained winds of 105 mph (Category 2) . Norbert's central pressure of 956 mb at landfall made it the 3rd strongest hurricane to hit the Pacific coast of Mexico since record keeping began in 1949. Norbert killed eight, knocked out power to 20,000 homes, and damaged or destroyed 40% of the homes on the islands of Margarita and Magdalena. Norbert crossed the Baja Peninsula and made landfall on Mainland Mexico as a Category 1 hurricane with 85 mph winds.

Only two major hurricanes have made landfall on Baja since record keeping began in 1949. Both hurricanes hit the east (Gulf of California) side of Baja. The first was Hurricane Olivia of 1967. Olivia made landfall on October 13, 1967 as a Category 3 hurricane with 125 mph winds. Due to its small size and the unpopulated region of coast it hit, damage was minimal. The second major hurricane was Hurricane Kiko, which made landfall on August 27, 1989, as a Category 3 hurricane with winds of 115 mph (minimal Category 3). Kiko was a small hurricane and hit a relatively unpopulated area, resulting in no loss of life and only scattered reports of damage.


Figure 3. A plot of all the major hurricanes to pass within 200 miles of Mexico's Baja Peninsula since 1949. Image credit: NOAA Coastal Services Center.

California fire webcams
As I discussed in yesterday morning's post, you can use our wundermap for Los Angeles with the fire layer turned on to see where the fire and smoke are located, and track the temperatures and winds during today's air pollution event. We also have two webcams with views of the fire: Altadena and Tujunga.

I'll have an update by 4pm this afternoon, when the data from the next hurricane hunter flight into Erika will be available.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

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

Viewing: 461 - 411

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 | 28Blog Index

Quoting belizeweatherfan:
The conversations have been so enlightening today. I have heard Erika will potentially threaten the Lesser Antillies, Bahamas,The Carolinas Florida to Texas and everything in between...is the Yucatan safe? Back to lurking...thanks!


You should be fine.
Member Since: September 2, 2006 Posts: 110 Comments: 6877
Quoting ssmate:

That was an interesting point in the Doc's summary. In my 4 years here of mostly lurking I never heard of this shear dynamic. I never really understood the shear maps entirely. I remeber Gustav was going into a great shear environment according to the maps and behold, it was done in by shear. Frankly, I'm not sure anyone truly knows how shear will effect a storm unless it's an obvious 50-60 shear layer.


I've always thought of shear as the colic of tropical cyclones - it's a catch-all explanation for puzzling behavior. See a storm that all the models develop break apart? Well, they probably missed some local shear. Watching a storm unable to develop a closed center of circulation? Must be a current of shear.

I'm not saying the explanation is wrong. But the bottom line is that shear is a major element of cyclone formation and development that we really don't understand and lack the tools to measure effectively. We can know precisely how strong winds around an airplane are, but relatively small currents of air are virtually impossible to detect with satellites, radar, or even direct instrumentation. We tend to measure it either on the broadest scale, or inferentially - if we see its probably effects, we know it's there. And that's a terrible way to do science.

I'm just not sure what the null hypothesis is here. Dr. Masters says that we're seeing the effects of small-scale shear, because if it wasn't there, the storm wouldn't be behaving like this. Is there any way to evaluate the veracity of that claim?
Member Since: Posts: Comments:
Quoting alaina1085:
Pat,

Are you enjoying this wonderful weather? Im sitting on my back porch with my laptop. The breeze is blowing, the humidity is low now alls I need is a margarita!


I have the Front door Open and the Far BAck Door and I swear It feels and smells Like October almost
Member Since: Posts: Comments:
Are there actually living people in texas?
Member Since: May 10, 2007 Posts: 0 Comments: 960
Quoting LUCARIO:


texas
Wow, what a surprise.
Member Since: Posts: Comments:
Quoting alaina1085:


Ahh yes this time last year I was sweating my tush off with no AC and waiting in 4 hour lines for groceries! Dont want that again..ever.


Yeah,,heres a View Back to Gustav's first Band entering Uptown NOLA

Church Bells in the Distance was creepy as Most were well gone by this time.

Member Since: Posts: Comments:
Quoting TreasureCoastFl:

It goes to my blog but I scroll down and look everywhere , there is no added name and no where to add one.. weird. Guess I need to check my settings or something. Thanks



Did you try logging out, then logging back in?
Member Since: Posts: Comments:
The conversations have been so enlightening today. I have heard Erika will potentially threaten the Lesser Antillies, Bahamas,The Carolinas Florida to Texas and everything in between...is the Yucatan safe? Back to lurking...thanks!
Member Since: Posts: Comments:
Looks like we may have a low trying to form off the coast of Jax. I'm on my phone at the moment and can't post the NEXRAD loop.
Member Since: Posts: Comments:
Pat,

Are you enjoying this wonderful weather? Im sitting on my back porch with my laptop. The breeze is blowing, the humidity is low now alls I need is a margarita!
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting LUCARIO:


yes

texas has gotten over 5 storms in the past two years. it will shock me if erika doesn't go to texas.


wow... i was obviously not being serious
Member Since: Posts: Comments:
Quoting LUCARIO:


texas
big surprise.. lol
Member Since: Posts: Comments:
Quoting BioWeather:

Where do you live Lucario?

In his own little world...
Member Since: Posts: Comments:
Again, just watch Erika. A 50/50 chance of it dissipating but even if it strengthens, I believe it has missed it's opportunity to head north into the first weakness. The next one will be after that ridge builds, if Erika remains a slow mover, it can recurve on the second weakness.
Member Since: Posts: Comments:
I always have my tv turned on for bakground noise. I flip it through out the day between the WC, and the local news stations. I have to say I have never heard so many people confused about a storm in all my life. They have the Erika story on over and over, and continue to repeat "we just don't know, over and over. South Florida is notorious for weather repeating its self day in and day out. What a change a indecisive storm can make.
Member Since: Posts: Comments:
Quoting IKE:


I just clicked "Ignore User" under your post and it went to my blog and added your name. You have to then scroll to the bottom of the page and click..."add ignored user"..and it takes care of it.

It goes to my blog but I scroll down and look everywhere , there is no added name and no where to add one.. weird. Guess I need to check my settings or something. Thanks
Member Since: Posts: Comments:
Zap! (code word for poof)
Member Since: Posts: Comments:
Quoting BioWeather:

Where do you live Lucario?


texas
Member Since: Posts: Comments:
Quoting btwntx08:
hey can we get a radar link out of the antellies

http://hurricanewarning1.com/radar.html
All publicly available radars. Link in my blog if you lose it and need it later.
Member Since: Posts: Comments:
Quoting btwntx08:
hey can we get a radar link out of the antellies


Er,,try Googling Antilles Radar,..Im sure sumting will tickle yer fancy.

Its not a Frigging drive thru here..Drive around ,and Pay at Ikes window to collect yer meal
Member Since: Posts: Comments:
441. JLPR
Quoting btwntx08:
hey can we get a radar link out of the antellies


yep
Link
Member Since: Posts: Comments:
Quoting Patrap:
Finally..One Year ago today.

2 Sept 2008

And a shout out to the Se. La. River Parishes for a Continued recovery from Gustav.





Ahh yes this time last year I was sweating my tush off with no AC and waiting in 4 hour lines for groceries! Dont want that again..ever.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting tornadodude:


so basically evacuate the entire state of texas, a few hail mary's, and assume the fetal position?


yes

texas has gotten over 5 storms in the past two years. it will shock me if erika doesn't go to texas.
Member Since: Posts: Comments:
Quoting TheCaneWhisperer:


Not from me! It's known she'll struggle today but, little advances here and there are taking place.


Definitely taking a stab at pulling convection over the center again.

Member Since: Posts: Comments:
Quoting BioWeather:

Where do you live Lucario?
Ummm I would guess TX
Member Since: Posts: Comments:
I was on a cruise ship this time last year going right thru Hanna.....not fun at all!!!
Member Since: Posts: Comments:
Quoting NRAamy:
prove it


You guys are killing me...it's like a stretch of road with Burmashave signs
Member Since: August 2, 2006 Posts: 10 Comments: 9922
Quoting LUCARIO:
Erika looks amazing, I have a weird feeling she is going to go into the GOMEX. She will hot the western gulf texas or mexico. I don't think this is a florida storm. Florida is protected, God has blessed them. Erika is going to make Ike and Gustav looks like a tropical wave.

Where do you live Lucario?
Member Since: Posts: Comments:
Finally..One Year ago today.

2 Sept 2008

And a shout out to the Se. La. River Parishes for a Continued recovery from Gustav.



Member Since: Posts: Comments:
This wave is coming off around 10N, but so did the last wave and it went immediately North. Any take on what direction this wave will head after exiting?
Member Since: Posts: Comments:
430. IKE
Quoting TreasureCoastFl:

It doesn't work for me either. I just tried again. just FYI


I just clicked "Ignore User" under your post and it went to my blog and added your name. You have to then scroll to the bottom of the page and click..."add ignored user"..and it takes care of it.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
429. JLPR
wheres Kman? xD

He got it right, Erika wants to enter the Caribbean =P

now im looking at a 40miles to my NE pass or even a direct landfall =|

could Erika strengthen before reaching me? (PR)
Member Since: Posts: Comments:
Quoting tornadodude:


so basically evacuate the entire state of texas, a few hail mary's, and assume the fetal position?

LMAO!!
Member Since: Posts: Comments:
Quoting rwdobson:


From Dr M "The trouble with the various wind shear analyses we use is that they take a crude average of winds over a thick layer to arrive at an average shear, and this large-scale average shear does not capture thin layers of shear that can dramatically affect a tropical cyclone."

Why are you bothering with shear tools that have been shown to be worthless with Erika?

That was an interesting point in the Doc's summary. In my 4 years here of mostly lurking I never heard of this shear dynamic. I never really understood the shear maps entirely. I remeber Gustav was going into a great shear environment according to the maps and behold, it was done in by shear. Frankly, I'm not sure anyone truly knows how shear will effect a storm unless it's an obvious 50-60 shear layer.
Member Since: Posts: Comments:
Get ready,,,wait for it..itsa coming real soon..!
Member Since: Posts: Comments:
Quoting LUCARIO:
Erika looks amazing, I have a weird feeling she is going to go into the GOMEX. She will hot the western gulf texas or mexico. I don't think this is a florida storm. Florida is protected, God has blessed them. Erika is going to make Ike and Gustav looks like a tropical wave.


so basically evacuate the entire state of texas, a few hail mary's, and assume the fetal position?
Member Since: Posts: Comments:
Erika iz and always has been a Large CV Circulation.

And to her detriment as well. When she cranks up a Good Up Cycle,she spins out and Loses her Org,and she may never recover fully under the shear attack aloft.
She has to Consolidate a real CoC within the Center of the overall Circ,or this cycle will Keep repeating till she just spins out and goes das Poof.

Das Poof is a good thing.

Were in that critical window of Climatology that allows for the Super CV's to well,you Know.
Member Since: Posts: Comments:
i agree totally
Member Since: Posts: Comments:
Quoting Patrap:
Jeesum..Im sitting here typing away and the NOAA Radio Goes off with that creepy Weds Test and I nearly Jumped out me chair ans Broke a Hip..

That happened to me with the sonic boom from the shuttle came in to land.
Member Since: Posts: Comments:
Quoting jeffs713:


Speaking of "fish casters"...

What *is* a fish storm?

My notion of a fish storm: Link
Member Since: Posts: Comments:
Quoting TreasureCoastFl:


I think you bootycasted? ;)

yall are too funny
Member Since: Posts: Comments:
"taking a comma-like shape"

this kind of shape is characteristic of extra-tropical or sub-tropical storms, not tropical cyclones...
Member Since: Posts: Comments:
Quoting btwntx08:

agree

CIMMS sheer maps show low upper level sheer and about 25KT sheer on the mid levels per their 1200 UTC report. IF TS Erika can fight the sheer, she may have a chance! Sheer at both levels decrease once she passes Hispaniola. The question is, will she make it??
Member Since: Posts: Comments:
Quoting Patrap:
Jeesum..Im sitting here typing away and the NOAA Radio Goes off with that creepy Weds Test and I nearly Jumped out me chair ans Broke a Hip..



LOL - those weather radio test have a way of knowing when you are not expecting them
Member Since: Posts: Comments:
Quoting stormpetrol:

Erika catchin up to the old LLC moving slightly south of due west at a liitle faster clip, new center just about fully formed and becoming the dominant one at 16N/60W, taking a comma like shape, getting in gear one might say just my opinion, I guess I'll blasted as usual :)


Not from me! It's known she'll struggle today but, little advances here and there are taking place.
Member Since: Posts: Comments:
Erika looks amazing, I have a weird feeling she is going to go into the GOMEX. She will hot the western gulf texas or mexico. I don't think this is a florida storm. Florida is protected, God has blessed them. Erika is going to make Ike and Gustav looks like a tropical wave.
Member Since: Posts: Comments:
Quoting IKE:


Yeah, I see one....acting like a 12 year-old on here.

It doesn't work for me either. I just tried again. just FYI
Member Since: Posts: Comments:
Quoting Patrap:
Jeesum..Im sitting here typing away and the NOAA Radio Goes off with that creepy Weds Test and I nearly Jumped out me chair ans Broke a Hip..


I would have paid to see you jump out of your chair like that. (just without any potential broken bones)

Of course, I get a sick and demented kick out of watching people jump from their chairs.
Member Since: August 3, 2008 Posts: 16 Comments: 5881
Quoting OracleDeAtlantis:


I agree, but it's also evident that these multiple COC's are going to combine eventually to form a much larger circulation. This is how truly great systems are born. They start out coughing and choking under water, and when they finally get to the surface, they take this enormous breath that begins a perilous march westward.


The Oracle of Atlantis, huh? As in, a prophet of doom and destruction?

It's true that some powerful storms begin with broad and disorganized convection, and that as they consolidate multiple low level centers they grow into monsters. Sure. It's also true that many broad and disorganized areas of convection dissipate without ever amounting to much, because they're unable to consolidate. And that some which do consolidate, but face high sheer, never achieve anything close to their potential.

For now, the salient fact is that Erika is disorganized. Until she pulls it together, she's as much a potential thunderstorm as she is a potential major hurricane. There's no point focusing on one prospect at the expense of the other. Uncertainty is the watchword of the hour - sometimes, you just gotta keep hitting refresh, and waiting for more information.
Member Since: Posts: Comments:

Viewing: 461 - 411

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 | 28Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.