Today's look sees Ivan not budging off his mostly 325-330* track up from the Caribbean. These lax steering synoptics can be very hard to read without trough amplitude data. Right now the extrap line is headed right for New Orleans.
I can't tell from WV image whether that dry air in the southern US is a High building in behind the trough or just a stationary air pool associated with the trough. If it's a High setting up expect this 325* track to maintain without much curve.
The key here is Ivan's slow forward speed. If he stays slow it should give the west-east CONUS flow time to bring a moving trough in on Ivan before landfall and hook him inshore ala NHC. From this present trend we can discount any trough-grabbing speculation for an early north turn. Like Frances, Ivan has entered a weak steering regime under the same zonal laxness that allowed the subtropical ridge to come so far in below it.
I expect the shear presently easing Ivan down in intensity will continue, bringing Ivan's windspeed slowly down all the way to shore. However, we can't discount an unexpected lull and perfect overhead conditions showing up before landfall. So, a re-boost over warm waters prior to landfall should always be watched for. My personal instincts tell me the 2004 conditions that inhibited Bonnie from preshore intensification are probably still in place, so the intensity downcurve should be fairly expected.
Landfall is then the main question. Since Ivan has trended west for his entire history it would be reasonable to bias him slightly west and call for a near Mississippi/Mobile landfall. The CONUS flow is the hinge here. If it picks up, Ivan will curve east before landfall and hit west of Pensacola. If a High fills in behind the weak trough, New Orleans is not unreasonable...
Current Ivan Track
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Current Ivan Track
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We had a beautiful sunset last night with flaming pastel tropical pink/oranges glowing on the bottom of a quilted gauze mid-level overcast rippled cloud blanket.
A load of bricks was lifted off us here in Charley's wreckage zone. We were spared another evacuation and giant hassle, not being allowed back for days, and more prolonged damaged just under the deductable. Not to mention a primitive lifestyle for another week without utilities.
All this and Ivan isn't even above the Keys yet.
We have a solid overcast and blustery breezes here...
A load of bricks was lifted off us here in Charley's wreckage zone. We were spared another evacuation and giant hassle, not being allowed back for days, and more prolonged damaged just under the deductable. Not to mention a primitive lifestyle for another week without utilities.
All this and Ivan isn't even above the Keys yet.
We have a solid overcast and blustery breezes here...
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LAwxrgal
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The sky here as I awakened this morning was a weird but beautiful mixture of orange and white. I'd never seen it before except the day before Andrew hit 12 years ago. I wonder if it's an omen?
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Andrew 92/Isidore & Lili 02/Bill 03/Katrina & Rita 05/Gustav & Ike 08/Isaac 12 (flooded my house)/Harvey 17/Barry 19/Cristobal 20/Claudette 21/Ida 21 (In the Eye)/Francine 24
Wake me up when November ends
Wake me up when November ends
If he is still tumbling 325* this afternoon keep watching New Orleans. Slow speed means he hasn't been picked up any US weather features and is moving along under intertia on the tropical flow. If a High builds in...
Last edited by Sanibel on Tue Sep 14, 2004 2:35 pm, edited 1 time in total.
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3:30
Still no pull north. Phew.
Ivan is showing us the US trough is a non-feature at his latitude. His slow forward speed is telling us he is below the CONUS steering currents and still coming into the GOM on the tropical flow. He is still south of Key West in latitude.
His movement is still right for New Orleans. The extrap never verifies, so those to its east should be getting ready. The tropical flow in this area comes in from the Caribbean and hooks around to the NE. Movement estimates based on climatology should blend a normal mild recurve in weak synoptics with the potential that the CONUS zonal flow is really weak and recessed up over land.
These inputs should resolve a blend between the two influences. If a ridge should establish on the north Gulf shore New Orleans is practically guaranteed. The wild-card input being Ivan's persisting tendency to go west of track. Maybe a 140mph storm would also resist weak synoptics to the extrap side.
Right now the track can only be an educated guess that these climatological factors play out straight. In this case Pascagoula should be a reasonable landfall. Intensity does not seem to be dropping that fast.
We can only wait until later tonight to see if any curve occurs...
Still no pull north. Phew.
Ivan is showing us the US trough is a non-feature at his latitude. His slow forward speed is telling us he is below the CONUS steering currents and still coming into the GOM on the tropical flow. He is still south of Key West in latitude.
His movement is still right for New Orleans. The extrap never verifies, so those to its east should be getting ready. The tropical flow in this area comes in from the Caribbean and hooks around to the NE. Movement estimates based on climatology should blend a normal mild recurve in weak synoptics with the potential that the CONUS zonal flow is really weak and recessed up over land.
These inputs should resolve a blend between the two influences. If a ridge should establish on the north Gulf shore New Orleans is practically guaranteed. The wild-card input being Ivan's persisting tendency to go west of track. Maybe a 140mph storm would also resist weak synoptics to the extrap side.
Right now the track can only be an educated guess that these climatological factors play out straight. In this case Pascagoula should be a reasonable landfall. Intensity does not seem to be dropping that fast.
We can only wait until later tonight to see if any curve occurs...
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His forward speed has been pretty consistent, but, like you said, his defiance of the anticipated northward trend has also been consistent. Either way with his wind field, NO will be in for a rough time.
The shear better kick it up a notch and/or more dry air entrainment by the time he hits that eddy. Hopefully we won't see any explosive deepening.
The shear better kick it up a notch and/or more dry air entrainment by the time he hits that eddy. Hopefully we won't see any explosive deepening.
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Stormcenter
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Sanibel wrote:3:30
Still no pull north. Phew.
Ivan is showing us the US trough is a non-feature at his latitude. His slow forward speed is telling us he is below the CONUS steering currents and still coming into the GOM on the tropical flow. He is still south of Key West in latitude.
His movement is still right for New Orleans. The extrap never verifies, so those to its east should be getting ready. The tropical flow in this area comes in from the Caribbean and hooks around to the NE. Movement estimates based on climatology should blend a normal mild recurve in weak synoptics with the potential that the CONUS zonal flow is really weak and recessed up over land.
These inputs should resolve a blend between the two influences. If a ridge should establish on the north Gulf shore New Orleans is practically guaranteed. The wild-card input being Ivan's persisting tendency to go west of track. Maybe a 140mph storm would also resist weak synoptics to the extrap side.
Right now the track can only be an educated guess that these climatological factors play out straight. In this case Pascagoula should be a reasonable landfall. Intensity does not seem to be dropping that fast.
We can only wait until later tonight to see if any curve occurs...
Ivan's forward speed has picked up for 9 to 10mph. Is this a good sign?
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Yes. The storm is starting its final weakening now. Up to 931 and shouldn't go down again.
If it is moving faster it is because it is finally detecting the continental flow.
New Orleans is safe now. A better WV loop shown by Lyons on TWC shows the trough edge pushing now. It's all a matter of timing, but Mobile is becoming more likely again...
Expect to see a curve starting now and mild recurve into around Mobile. If the trough is late it could be a little further west...
If it is moving faster it is because it is finally detecting the continental flow.
New Orleans is safe now. A better WV loop shown by Lyons on TWC shows the trough edge pushing now. It's all a matter of timing, but Mobile is becoming more likely again...
Expect to see a curve starting now and mild recurve into around Mobile. If the trough is late it could be a little further west...
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Cape Verde
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Sanibel wrote:Yes. The storm is starting its final weakening now. Up to 931 and shouldn't go down again.
If it is moving faster it is because it is finally detecting the continental flow.
New Orleans is safe now. A better WV loop shown by Lyons on TWC shows the trough edge pushing now. It's all a matter of timing, but Mobile is becoming more likely again...
Expect to see a curve starting now and mild recurve into around Mobile. If the trough is late it could be a little further west...
What does SAFE mean?
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From what I am seeing the cloud tops are starting to weaken near Ivan's center. I think the continental airmass has finally overtaken and weakened the tropical core Ivan maintained up from the Caribbean.
If my eye is correct the trough pushing from the west has finally moved the flow north of Ivan eastward making him pull into a mild curve that will force him away from New Orleans as he approaches the coast...
If my eye is correct the trough pushing from the west has finally moved the flow north of Ivan eastward making him pull into a mild curve that will force him away from New Orleans as he approaches the coast...
Last edited by Sanibel on Tue Sep 14, 2004 9:21 pm, edited 1 time in total.
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Sean in New Orleans
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Sanibel wrote:Yes. The storm is starting its final weakening now. Up to 931 and shouldn't go down again.
If it is moving faster it is because it is finally detecting the continental flow.
New Orleans is safe now. A better WV loop shown by Lyons on TWC shows the trough edge pushing now. It's all a matter of timing, but Mobile is becoming more likely again...
Expect to see a curve starting now and mild recurve into around Mobile. If the trough is late it could be a little further west...
Are you saying that everybody who left should turn around and come back home?
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