ATL: IRMA - Post-Tropical - Discussion

[wxman57]

Recon is finding that Irma is down to a Cat 3 with 105kt winds. Cuba hit it hard, but it should recover once it moves away from the coast. Could still be a Cat 4 when it hits Florida. The interaction with land will cause the wind field to expand, too. Hurricane force winds over a larger area. Keys residents are all evacuated, I hope. Starting my 12hr shift...

Hey WX,

Has the shortwave been on track to steer IRMA north, or are we probably going to see it making a run at the Panhandle? Would appreciate your input!

It'll be hard to hit the Panhandle, except for maybe where it bends around into the Peninsula. One other thing, Irma will be wobbling left and right 15-20 miles as it tracks north. Tampa Bay is the only other area of the U.S. Coast that is as surge-vulnerable as the central Gulf Coast. The shoaling factor is nearly 2.0, which is a surge multiplier in the calculations. A wobble left with the center going into Tampa Bay could inundate the city like they haven't seen in over 50 years.

[GCANE]

Product: Air Force Vortex Message (URNT12 KNHC)

A. Time of Center Fix: 9th day of the month at 10:12:30Z
B. Center Fix Coordinates: 22°32'N 79°03'W (22.5333N 79.05W)

D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 101kts (~ 116.2mph)
F. Maximum Flight Level Wind Inbound: From 141° at 108kts (From the SE at ~ 124.3mph)

H. Minimum Sea Level Pressure: 937mb (27.67 inHg)

I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 11°C (52°F) at a pressure alt. of 3,045m (9,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 16°C (61°F) at a pressure alt. of 3,046m (9,993ft)

L. Eye Character: Closed
M. Eye Shape & Diameter: Circular with a diameter of 15 nautical miles (17 statute miles)

Remarks Section:
Maximum Flight Level Wind: 112kts (~ 128.9mph) which was observed 18 nautical miles (21 statute miles) to the NNE (26°) from the flight level center at 8:32:30Z
Dropsonde Surface Wind at Center: From 240° at 12kts (From the WSW at 14mph)

[tolakram]

These are the most dangerous types of storms. They lose their sex appeal and some of the younger ones (and unfortunately some who should know better) suddenly become expert hurricane forecasters and think the danger is over. Ike was a great example, with the huge windfield and massive surge when it finally lumbered onshore.

If you've come here to post about how this won't be so bad, or to argue with mets, or to criticize the NHC you will find posting privileges lost pretty quickly. This is not a platform to spread your sudden expertise or anger about a forecast not working out the way you wanted. Irma is a very dangerous storm and this is not the time to downplay it.

[srainhoutx]

Recon is finding that Irma is down to a Cat 3 with 105kt winds. Cuba hit it hard, but it should recover once it moves away from the coast. Could still be a Cat 4 when it hits Florida. The interaction with land will cause the wind field to expand, too. Hurricane force winds over a larger area. Keys residents are all evacuated, I hope. Starting my 12hr shift...

Lucky you... Today will make for the 10th day of 16 hour long days in recovery from Harvey.

[tolakram]

COD IR loop

http://weather.cod.edu/satrad/exper/?parms=meso1-13-200-1-10

[NDG]

[Hypercane_Kyle]

Very potent structure in place, and the polar outflow has expanded significantly. It'll be interesting what type of ventilation that provides, before shearing the system.

[srainhoutx]

To add what wxman57 stated, During my time in Key west back in the early to mid 2000's we witnessed several Hurricanes exit Cuba and re intensify fairly quickly as they cross the Gulf Stream. Do NOT be deceived into thinking that Irma will not be a very dangerous and very possibly Catastrophic especially for the Keys, the Everglades and SW Florida. Tornadoes are a big concern particularly in the Miami/Ft Lauderdale/Palm Beaches and inland to Orlando. As we experienced here in SE Texas after Harvey moved inland near Rock Port, a large wedge tornado hit just 3 miles from my home in NW Harris County some 200 miles ENE of the center in a feeder band. Do NOT let your guard down what so ever if you are in Florida. Stay Safe gang.

[stormreader]

Very potent structure in place, and the polar outflow has expanded significantly. It'll be interesting what type of ventilation that provides, before shearing the system.

Thinking the same thing. Took a pretty good hit, but for the reasons you mentioned, I'd be surprised if we don't get some fairly significant intensification in the Straits. At 940mb at 5amEdt, could maybe come in at 925mb???

[wxman57]

Recon is finding that Irma is down to a Cat 3 with 105kt winds. Cuba hit it hard, but it should recover once it moves away from the coast. Could still be a Cat 4 when it hits Florida. The interaction with land will cause the wind field to expand, too. Hurricane force winds over a larger area. Keys residents are all evacuated, I hope. Starting my 12hr shift...

Lucky you... Today will make for the 10th day of 16 hour long days in recovery from Harvey.

I think you & Tim will have enough work to last the rest of your lives after Harvey. As for Irma, I'm thinking it drops to a Cat 2 by this afternoon, as it will be over land in Cuba then. I have it regaining Cat 3 strength as it passes the Keys, though. Wind field much larger, surge threat higher than a smaller Cat 4.

[NDG]

https://i.imgur.com/nYHLPRB.jpg

Very potent structure in place, and the polar outflow has expanded significantly. It'll be interesting what type of ventilation that provides, before shearing the system.

Thinking the same thing. Took a pretty good hit, but for the reasons you mentioned, I'd be surprised if we don't get some fairly significant intensification in the Straits. At 940mb at 5amEdt, could maybe come in at 925mb???

That's what the Euro shows, it could even be lower than that if we were to come to a consensus between it and the GFS which as it sub 900mb.

[stormreader]

Interesting to see what the eye circumference will be like at Fl landfall, too. Conventional wisdom is that interaction with land should have produced a larger and less tightly wound system, and that even if it reintensifies, it will have a larger eye and overall structure. I don't know. The core of the storm still looks very good. We'll see. The eye looks smaller now, and I wonder if it might reorganize around a smaller, tighter eye feature in the Straits. Could have possibility of quicker ramp up of winds around a smaller eye.

[johngaltfla]

Recon is finding that Irma is down to a Cat 3 with 105kt winds. Cuba hit it hard, but it should recover once it moves away from the coast. Could still be a Cat 4 when it hits Florida. The interaction with land will cause the wind field to expand, too. Hurricane force winds over a larger area. Keys residents are all evacuated, I hope. Starting my 12hr shift...

Lucky you... Today will make for the 10th day of 16 hour long days in recovery from Harvey.

I think you & Tim will have enough work to last the rest of your lives after Harvey. As for Irma, I'm thinking it drops to a Cat 2 by this afternoon, as it will be over land in Cuba then. I have it regaining Cat 3 strength as it passes the Keys, though. Wind field much larger, surge threat higher than a smaller Cat 4.

Good call. Local mets are getting VERY concerned about surge into Tampa Bay if the storm track verifies up the spine of the state.

[Kingarabian]

These are the most dangerous types of storms. They loose their sex appeal and some of the younger ones (and unfortunately some who should know better) suddenly become expert hurricane forecasters and think the danger is over. Ike was a great example, with the huge windfield and massive surge when it finally lumbered onshore.

If you've come here to post about how this won't be so bad, or to argue with mets, or to criticize the NHC you will find posting privileges lost pretty quickly. This is not a platform to spread your sudden expertise or anger about a forecast not working out the way you wanted. Irma is a very dangerous storm and this is not the time to downplay it.

For some, it seems that the season is dead if no hurricane hits the CONUS. If the hurricane is a weak one, it's brushed off. And now if the system is not a cat.5 at landfall then it's downplayed.

[northjaxpro]

Gone be a close call if it goes a bit inland of Cuba or stays just off shore.

Eye is moving w/nw parallel right along.the coast. As long as Irma continues on this header and provided she does not wobble south of west, the eyewall will remain pretty much intact.

It will probably be a Cat 3 / Low end 4 when it finally emerges off the Cuba coast and makes the turn north. The Eye wall will will move very near or right over Key West. But, I think the eye wall will be still in good shape to recover and re intensify before the next landfall point on the SW Florida peninsula late tonight into tomorrow morning.

[stormreader]

Very potent structure in place, and the polar outflow has expanded significantly. It'll be interesting what type of ventilation that provides, before shearing the system.

Thinking the same thing. Took a pretty good hit, but for the reasons you mentioned, I'd be surprised if we don't get some fairly significant intensification in the Straits. At 940mb at 5amEdt, could maybe come in at 925mb???

That's what the Euro shows, it could even be lower than that if we were to come to a consensus between it and the GFS which as it sub 900mb.

Just got up. Didn't see that GFS intensity forecast. Pretty remarkable considering the land interaction and the weakening that took place over Cuba.

[stormreader]

Gone be a close call if it goes a bit inland of Cuba or stays just off shore.

Eye is moving w/nw parallel right along.the coast. As long as Irma continues on this header and provided she does not wobble south of west, the eyewall will remain pretty much intact.

It will probably be a Cat 3 / Low end 4 when it finally emerges off the Cuba coast and makes the turn north. The Eye wall will will move very near or right over Key West. But, I think the eye wall will be still in good shape to recover and re intensify before the next landfall point on the SW Florida peninsula late tonight into tomorrow morning.

Looking at sat images, seems like the eye is completely off the main mass of the Cuban island. In the barrier islands, yes. But basically looks offshore to me. Can't see any further weakening, think its set to begin restrengthening now.

[NDG]

Irma is such a huge storm.

[euro6208]

Any news on the hurricane chasers chasing this?

[Kat5]

Nearing Landfall again.