Little change to Erika; Jimena makes landfall as a Category 2 hurricane

By: Dr. Jeff Masters , 7:30 PM GMT on September 02, 2009

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Tropical Storm Erika remains weak and disorganized, and the future track and intensity of the storm remain highly uncertain. The center has jumped several times over the past 12 hours, and now lies exposed to view, west of the main area of heavy thunderstorms. Radar animations out of Martinique show little organization of the echoes, and satellite imagery shows no low-level spiral bands or upper-level outflow. 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. The Hurricane Hunters are in the storm now, and have found a slight increase in the surface winds, up to 45 mph. They noted that the surface center was displaced 12 miles north of the center they found at 1500 feet, which is the sign of a disorganized storm undergoing wind shear.

The forecast for Erika
Erika is embedded in a weak steering current pattern, and the storm's current state of disorganization is allowing the center to make random jumps as it reforms near the heaviest thunderstorm activity. This makes for a low-confidence forecast. The future track of the storm will depend 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. The intensity forecast models did a poor job with Tropical Storm Danny last week, and appear to be repeating that poor performance with Erika. All of the major intensity forecast models predict substantial strengthening of Erika. This seems unlikely to occur, given the storm's current disorganization, and the predicted increase in wind shear along the path of Erika to 20 - 25 knots 3 - 5 days from now. The more southerly than expected track of the storm also brings the possibility that Erika will encounter the high mountains of Puerto Rico and Hispaniola. The GFS, GFDL, and Canadian models predict Erika will pass near Puerto Rico on Friday, then move over Hispaniola on Saturday. Erika in its current weak state would probably not survive an encounter with these islands. A wide range of scenarios is still possible for Erika, from outright dissipation (as forecast by the GFS, Canadian, and ECMWF models) to intensification to a Category 3 hurricane (as forecast by the HWRF model). Erika is a long-term threat to the Bahamas and U.S. East Coast if it is still around five days from now. Potential landfall locations range from Florida on Tuesday to North Carolina on Wednesday. The NOGAPS model has Erika potentially missing the U.S. entirely, scooting northwards between North Carolina and Bermuda. My current expectation is that Erika will dissipate on Saturday when it encounters Hispaniola.


Figure 1. Afternoon image of Tropical Storm Erika. The swirl of clouds just west of Guadeloupe island is the center. This center was what I had labeled a "false center" in this morning's post, and has taken over as the main center this afternoon.

Hurricane Jimena hits Baja
Hurricane Jimena made lanndfall on Mexico's Baja Peninsula late this morning near Cabo San Lazaro as a Category 2 hurricane with 100 mph winds. Jimena is the 2nd strongest hurricane to hit Baja's west coast since record keeping began in 1949. The only stronger storm was Hurricane Norbert, which made landfall in 2008 on the central Baja coast with sustained winds of 105 mph. Jimena has now weakened to a Category 1 storm, and will continue to weaken as it hits colder waters and interacts with land. No deaths or major damage have been reported from the storm.


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

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 Thursday morning.

Jeff Masters

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Viewing: 1987 - 1937

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1987. BKM77
It does look like it is trying to split... There are 2 areas ov convection... Has this ever happened on a tropical wave and I wonder how this will effect the overall storm.. Any ideas
Member Since: Posts: Comments:
Quoting atmoaggie:
1954: Yep. Sounds like land-based severe weather discussion to me.

One massive difference between what goes on there and the tropics. Severe WX on land is entirely dependent on high shear. Tropics? As little as possible.

Very little that goes on in a TC has much in common with a supercell on land. Given the shear (sheer) difference in the dynamics.

I see the discussions show examples from Oklahoma, South Dakota, and points in between.

If you think that is some corollary to what might happen here, forget about it. TCs do not split.
And if you think I am being overly sure of myself, well you are going to have to get to know me or ask someone.


Member Since: June 28, 2006 Posts: 24 Comments: 8201
1985. hydrus
Quoting Orcasystems:
We are hooped now :(

I just looked at the models... all of them show something starting in the future.. with the exception of the CMC.. it shows NOTHING coming... that has to be a bad thing.

true.
Member Since: Posts: Comments:
1984. 7544
nhc did post a new center can form at anytime looks like it will the one to the north with blow up

as for if she gets thru the little pocket of 20 to 25 shear and makes it to the bhammas where the shear is less the hawrf just may be right with the track but not the strenth
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Quoting rareaire:
Orca I was just looking at those same models and its a train a coming...


Yes.. but nothing on the CMC... its spooky
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting intunewindchime:
CMC has been like the boy that cried wolf in past years, always wrong. Seems more accurate this year, than in previous years.

But based on the past, you are right, that's not good.

Big improvements to the CMC, showing this season too, so far.
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Quoting Bordonaro:

Very interesting, I am a weather novice, is that possible here with Erika, or are the atmospheric dynamics similar?
Heck if I know. I barely understood it. LOL
I'm waiting for someone who does to chime in ...
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Quoting Tazmanian:
too bad i am not a mode on this blog
You are a fixture that has the respect of most of us who lurk and learn. It is the contribution of knowledgeable individuals like you that makes visiting this blog worth while. Keep up the good work. Now - is she going West or Northwest?
Member Since: Posts: Comments:
1954: Yep. Sounds like land-based severe weather discussion to me.

One massive difference between what goes on there and the tropics. Severe WX on land is entirely dependent on high shear. Tropics? As little as possible.

Very little that goes on in a TC has much in common with a supercell on land. Given the shear (sheer) difference in the dynamics.

I see the discussions show examples from Oklahoma, South Dakota, and points in between.

If you think that is some corollary to what might happen here, forget about it. TCs do not split.
And if you think I am being overly sure of myself, well you are going to have to get to know me or ask someone.
Member Since: Posts: Comments:
Orca I was just looking at those same models and its a train a coming...
Member Since: Posts: Comments:
Simply to keep up the spirit ... I feel impelled to repost the NHC official (and my recollection of The Weather Channel blah-blah-blah) for Hurricane Marilyn, which brought utter devastation to the USVI in in 1995 ....

11.8-55.6 - 45MPH (No Luis)
13.0-58.0 - 55MPH (Small, insignificant, nothing to worry about)
14.1-59.9 - 70 MPH (Barbados, oh sorry, but where next? The GOM or Miami?)
16.0-61.8 - 70MPH 9/15 00Z (Guadeloupe, crossing the chain, oh probably into the GOM?)
17.0-63.6 - 80MPH 9/15 12Z (Somewhere, minimal, mainly rain event, NOT Puerto Rico)
17.8-64.6 - ONLY 85 MPH 9/15 21Z My home (Oops, sorry St. Croix,)
18.4-65.2 - A MISUNDERSTOOD Measly 85MPH 9/16 06Z (Oops again, sorry St. Thomas)

Erica is not a joke to us who may be dealing with the "misplaced" head tomorrow! Thanks to everyone trying to figure this B... out ... XO

Member Since: Posts: Comments:
1975. Relix
Going to bed. Good night WU. Let's see what I wake up to!
Member Since: August 3, 2006 Posts: 0 Comments: 2648
CMC has been like the boy that cried wolf in past years, always wrong. Seems more accurate this year, than in previous years.

But based on the past, you are right, that's not good.
Member Since: Posts: Comments:
Quoting TreasureCoastFl:
We have used a three-dimensional cloud model to investigate the splitting of an initially isolated storm in a one-directional east-west shear. The simulated evolution of storm splitting in some cases follows all four stages suggested by Achtemeier (1969) after analysis of radar data, including the development of two self-sustaining storm. One of these storms moves to the right of the mean wind vector and the other to the left. In the right-moving storm the updraft rotates cyclonically and the downdraft anticyclonically, forming a vortex pair, as depicted in the schematic model of Fankhauser (1971). The vortex pair structure is also similar to that observed with Doppler radar and analyzed by Ray (1976). The downdraft-induced gust front interacts with the low-level environmental wind to produce the convergence necessary to sustain the storm. This convergence extends to the south and west of the storm, and if enough low-level moisture is available a flanking line develops. The distribution of rainwater within the updraft suggests the existence of an over-hang and book typically observed in severe storms.

To understand when splitting might occur the strength and distribution of the vertical wind shear were varied. The various simulations suggest that strong shear at and just above cloud base is important for the splitting process to be successful. For splitting to occur the low-level inflow from the cast in our simulations must be sufficiently strong to inhibit the propagation of the gust front toward the cast. If the gust front (or wind shift line) can propagate away from the storm toward the cast, the region of low-level convergence moves away from the storm and initial splitting in the lower updraft cannot he sustained. Further, without the precipitation-induced downdraft and associated low-level outflow splitting does not occur.

Very interesting, I am a weather novice, is that possible here with Erika, or are the atmospheric dynamics similar?
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1971. Greyelf
Quoting Patrap:


Ill say this once and pay attention Blogger. If you want to Bash on Taz..your gonna Have to Go thru this Former Jarhead to do it.

You might be a Lurker,..and well...you might be very uninformed as to the Long road to becoming a Good Forecaster Taz has become.

Id apologize ASAP.

Or stay a Lurker and take that foot outta yer mouth.

Not everything is B&W in the WWW.

And now,..your Dismissed.


The problem though, Pat, is that sometimes it's almost impossible to translate what Taz is saying. Yet, when someone takes the time they're having trouble interpreting his message, he seems to take offense versus working on what he could to try to improve. From my view, if I wanted to be read and understood, I'd do what it took to do that. Now, if Taz chooses not to, then well, I'll continue to just do what I've always done. I try to interpret once. If I don't get it, I give up and move on.
Member Since: Posts: Comments:
I was just looking at the RGB loop and I thought I saw a faint exposed LLC which has shot ahead again of the southern convective blob and is on the next forecast point (before it becomes an "L"). It is hard to imagine Erika can survive her present and future challenges beyond the next 12 hours.
Member Since: May 19, 2009 Posts: 0 Comments: 249
sorry forgot to post source:
http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0469%281978%29035197 4%3AANSOSS2.0.CO%3B2&ct=1
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1966. kachina
Good night everyone!

Be safe wherever you are and whatever you're doing.
Member Since: Posts: Comments:
Quoting szqrn1:
I appreciate ALL of you here .. I dont post much cause I dont know much about weather... but I can read your EKG and save your life God willing. I am grateful y'all are here and sharing your knowledge even when I do post and ask a somewhat stupid question ... Thanks to all .. live on MS coast and do need the guidance here!! So.... I will ignore the obnoxoius, judgemental, self absorbed ones that post crap on here about that y'all that I depend on here!! :))


your always welcome to ask your questions... as you can see very few on here no much about weather they are just here to antagonise the rest of us and IMO should probably not be left unattended in public!
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1964. Lizpr
North part getting bigger?


Member Since: Posts: Comments:
We are hooped now :(

I just looked at the models... all of them show something starting in the future.. with the exception of the CMC.. it shows NOTHING coming... that has to be a bad thing.

Member Since: October 1, 2007 Posts: 81 Comments: 26511
not much to blog about till morning...
have a good night,
Intune
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1959. szqrn1
I appreciate ALL of you here .. I dont post much cause I dont know much about weather... but I can read your EKG and save your life God willing. I am grateful y'all are here and sharing your knowledge even when I do post and ask a somewhat stupid question ... Thanks to all .. live on MS coast and do need the guidance here!! So.... I will ignore the obnoxoius, judgemental, self absorbed ones that post crap on here about that y'all that I depend on here!! :))
Member Since: Posts: Comments:
1957. KBH
Quoting atmoaggie:

And has everything to do with MCSs and supercells on land. Not at all applicable to the Caribbean.

well, this maybe the first time in the caribbean, so someone will have to give it a new name
Member Since: Posts: Comments:
too bad i am not a mode on this blog
Member Since: Posts: Comments:
Quoting atmoaggie:

And has everything to do with MCSs and supercells on land. Not at all applicable to the Caribbean.
We have used a three-dimensional cloud model to investigate the splitting of an initially isolated storm in a one-directional east-west shear. The simulated evolution of storm splitting in some cases follows all four stages suggested by Achtemeier (1969) after analysis of radar data, including the development of two self-sustaining storm. One of these storms moves to the right of the mean wind vector and the other to the left. In the right-moving storm the updraft rotates cyclonically and the downdraft anticyclonically, forming a vortex pair, as depicted in the schematic model of Fankhauser (1971). The vortex pair structure is also similar to that observed with Doppler radar and analyzed by Ray (1976). The downdraft-induced gust front interacts with the low-level environmental wind to produce the convergence necessary to sustain the storm. This convergence extends to the south and west of the storm, and if enough low-level moisture is available a flanking line develops. The distribution of rainwater within the updraft suggests the existence of an over-hang and book typically observed in severe storms.

To understand when splitting might occur the strength and distribution of the vertical wind shear were varied. The various simulations suggest that strong shear at and just above cloud base is important for the splitting process to be successful. For splitting to occur the low-level inflow from the cast in our simulations must be sufficiently strong to inhibit the propagation of the gust front toward the cast. If the gust front (or wind shift line) can propagate away from the storm toward the cast, the region of low-level convergence moves away from the storm and initial splitting in the lower updraft cannot he sustained. Further, without the precipitation-induced downdraft and associated low-level outflow splitting does not occur.
Member Since: Posts: Comments:
1951. hydrus
Quoting TreasureCoastFl:
It's grammar! Grammer is gramper's wife (is how I remember it..lol)
Grammer is Gramper,s wife,..that is funny.
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Quoting PortABeachBum:
Maybe his spelling and grammer is fine in his native language! Some have no trouble understanding.

I do wish he would speak up when it is busy in here, though. Hard to hear him sometimes. If it wasn't for reading lips I wouldn't know what he is saying at all.
Member Since: Posts: Comments:
Quoting stormwatcherCI:
Did you notice his spelling of grammar when he spoke about Taz's spelling and "grammer" ?

atmoaggie was right! !
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Quoting VoodooRue:


International Talk Like a Pirate Day is September 19. Seriously. Google it.


AWESOME! :)
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Taz is respected no doubt...I agree with Pat and Rare...but the talk like a pirate thing was freakin funny...
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Quoting intunewindchime:
We should have "Talk like a pirate day" on the blog... Then Taz won't get picked on.


International Talk Like a Pirate Day is September 19. Seriously. Google it.
Member Since: Posts: Comments:
a meno for the Admin


Please re move the Quote or Ignore User from the blogs


or fixs the Quote too where you are not Quoteing some one you may have on Ignore wish means there commets would be hiding even no you can still see there names on the blog even no some one is Quote them
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1944. kachina
Quoting atmoaggie:

Click uninstall not-free McAfee.
Click install AVG.
Fixed.


True. Uses less memory than McAfee too.
Member Since: Posts: Comments:
Quoting OracleDeAtlantis:
OK guys,

For any McAfee users experiencing the script blocks after the "false trojan" was blocked on their system, I have a solution for our beloved WU.

What I did was restored my system to a day before, and reset my McAfee updates to download but don't install. After which I restarted my browser and I can use the script features here again.

I call them "script blocks," but I'm sure some of the whiz bangs have a better word for it. The bottom line is, the site features here can be restored using this method. Hopefully this will give the McA**wipes time to get their update fixed.

Click uninstall not-free McAfee.
Click install AVG.
Fixed.
Member Since: Posts: Comments:
Quoting OracleDeAtlantis:
OK guys,

For any McAfee users experiencing the script blocks after the "false trojan" was blocked on their system, I have a solution for our beloved WU.

What I did was restored my system to a day before, and reset my McAfee updates to download but don't install. After which I restarted my browser and I can use the script features here again.

I call them "script blocks," but I'm sure some of the whiz bangs have a better word for it. The bottom line is, the site features here can be restored using this method. Hopefully this will give the McA**wipes time to get their update fixed.


Just got mine back. I'm using Cox Security Suite (McAfee) it took them a while to get the fix. I just tried updating again and it finally took. Situation normal
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Quoting Patrap:


Ill say this once and pay attention Blogger. If you want to Bash on Taz..your gonna Have to Go thru this Former Jarhead to do it.

You might be a Lurker,..and well...you might be very uninformed as to the Long road to becoming a Good Forecaster Taz has become.

Id apologize ASAP.

Or stay a Lurker and take that foot outta yer mouth.

Not everything is B&W in the WWW.

And now,..your Dismissed.
Did you notice his spelling of grammar when he spoke about Taz's spelling and "grammer" ?
Member Since: Posts: Comments:
Argh! Ye be right thar Patrap.
Taz be a fixture here for sure...

We know what we all mean after this many years....

I read every day. At least this years blog has been calmer that 2 years ago...
Member Since: Posts: Comments:
Quoting PortABeachBum:
Maybe his spelling and grammer is fine in his native language! Some have no trouble understanding.
It's grammar! Grammer is gramper's wife (is how I remember it..lol)
Member Since: Posts: Comments:
Lighten up on the Taz. He may not spell the best and he speaks in his own manner, But I have never had any trouble understanding what he meant to say. Many of you need to learn tolerance. Many on here type in English but are from other parts of the world and its a little blotchy. . Remember this before you go off and make yourself look less intelligent. This is a blog for crying out loud. Post your ideas and we can look it over. you may be wrong but its the mistakes we learn from.....
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Quoting Tazmanian:
talk about my bad spelling some of you dont do any better


We got your back Taz
Member Since: June 28, 2006 Posts: 24 Comments: 8201

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