ATL: IRMA - Models

[AutoPenalti]

Based on the models now what should palm beach, dade and broward county expect from Hurricane Irma.

The thing is, even if we were anywhere on the east or west side of the coast, the wind field stretches far and wide once it makes landfall. The question becomes who gets the NE quadrant, which is the nasty side, and based on the models, I think it would be us that would face it.

[ronjon]

06z NAVGEM - marathon to east Tampa.

https://www.tropicaltidbits.com/analysis/models/?model=navgem&region=watl&pkg=z500_mslp&runtime=2017090506&fh=114&xpos=0&ypos=0

shift east

Yes from Key West to Marathon and from west Tampa to east Tampa - slight.

[Ken711]

06z NAVGEM - marathon to east Tampa.

https://www.tropicaltidbits.com/analysis/models/?model=navgem&region=watl&pkg=z500_mslp&runtime=2017090506&fh=114&xpos=0&ypos=0

shift east

Yes from Key West to Marathon and from west Tampa to east Tampa - slight.

I think the Euro will follow in its next run.

[caneman]

That has to be an error. How can it go from Cuba to suddenly make a VERY sharp NE turn? All these models and their levels of uncertainty with this storm. I've never seen anything like it.

Happens in this area all the time. Their levels of uncertainty are actually pretty small, historically, the problem is when 50 miles makes all the difference in the world. We are just about 5 days from Florida so moving forward the track swings should start to lessen some. I wish I had a goo graphic to show the blend of only the quality models. I would put

Euro 40%, UKMET 30%, GFS 30% of the blend.

That's not far off the TVCN consensus - which also includes COAMPS and HWRF. Not sure what GHMI is though.

TVCN / TVCE / TVCA Variable Consensus of AVNI, CTCI, EGRI, EMXI, GHMI, and HWFI Model Track Forecasts

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

[Cuda]

Happens in this area all the time. Their levels of uncertainty are actually pretty small, historically, the problem is when 50 miles makes all the difference in the world. We are just about 5 days from Florida so moving forward the track swings should start to lessen some. I wish I had a goo graphic to show the blend of only the quality models. I would put

Euro 40%, UKMET 30%, GFS 30% of the blend.

That's not far off the TVCN consensus - which also includes COAMPS and HWRF. Not sure what GHMI is though.

TVCN / TVCE / TVCA Variable Consensus of AVNI, CTCI, EGRI, EMXI, GHMI, and HWFI Model Track Forecasts

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

[Blown Away]

Happens in this area all the time. Their levels of uncertainty are actually pretty small, historically, the problem is when 50 miles makes all the difference in the world. We are just about 5 days from Florida so moving forward the track swings should start to lessen some. I wish I had a goo graphic to show the blend of only the quality models. I would put

Euro 40%, UKMET 30%, GFS 30% of the blend.

That's not far off the TVCN consensus - which also includes COAMPS and HWRF. Not sure what GHMI is though.

TVCN / TVCE / TVCA Variable Consensus of AVNI, CTCI, EGRI, EMXI, GHMI, and HWFI Model Track Forecasts

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

NHC only made slight N adjustment to the 5 day and I think that means they are still leaning on Euro even though other guidance has shifted a bit E...

[tolakram]

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

I'm not sure anyone has a good answer. My AMATEUR opinion is that once onshore the winds may be near hurricane strength for a while but then mostly gusts as it winds down. Wilma was a good example of a very fast moving storm that raked Florida both with winds and forward speed. What will this storm do ... I'm not sure we have any good examples. Again, reminder my opinion is amateur.

[MatthewsRevenge]

I think the models pushing east are only doing so because they see a strong trough and weak ridging whereas Euro still thinks the ridge would be too powerful to make that sharp north push.

[Dean4Storms]

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

I'm not sure anyone has a good answer. My AMATEUR opinion is that once onshore the winds may be near hurricane strength for a while but then mostly gusts as it winds down. Wilma was a good example of a very fast moving storm that raked Florida both with winds and forward speed. What will this storm do ... I'm not sure we have any good examples. Again, reminder my opinion is amateur.

Yes but not only just hurricane strength straight line winds but tornadoes. Opal messed up Montgomery, AL pretty bad and it was a weakening Cat.3 and the terrain is not near as flat as south FL nor as marshy. So not only the possibility of falling tree's but structural damage is quite possible with a storm that strong moving northward at a good clip over southern FL. The other aspect is a good shot at no power or running water for days to take into consideration. If you make a strong enough storm room near the center of your home and have prepared well and have a generator I might stay, otherwise I'd leave.

[Steve]

Nothing new of note on the 12km 12Z NAM. Upper pattern across the US looks the same as it has been showing. Ignore the track of Irma from NAM for now.
https://www.tropicaltidbits.com/analysi ... 0&ypos=440

[TreasureIslandFLGal]

That's not far off the TVCN consensus - which also includes COAMPS and HWRF. Not sure what GHMI is though.

TVCN / TVCE / TVCA Variable Consensus of AVNI, CTCI, EGRI, EMXI, GHMI, and HWFI Model Track Forecasts

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

You don't evacuate from the winds unless you are in an unsafe/unsturdy structure like a mobile home or old construction prior to Andrew 92 building codes and no additional mitigation has been done. i.e. windows are not hurricane rated and roof has no strapping. Otherwise, you evacuate to get out of the way of storm surge and out of flood plains and known flooding zones.
And what many do is evacuate way too far away! You don't have to go hundreds of miles, unless you are trying to avoid all possible impacts and a temporary lack of electricity. You usually just have to go inland just enough to get to higher ground and sturdier buildings. That may simply be 5 miles inland for you. It may be 100. The closer you remain, the easier to get back and help with recovery efforts--which hopefully won't be needed--in your area.

[Cuda]

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

You don't evacuate from the winds unless you are in an unsafe/unsturdy structure like a mobile home or old construction prior to Andrew 92 building codes and no additional mitigation has been done. i.e. windows are not hurricane rated and roof has no strapping. Otherwise, you evacuate to get out of the way of storm surge and out of flood plains and known flooding zones.
And what many do is evacuate way too far away! You don't have to go hundreds of miles, unless you are trying to avoid all possible impacts and a temporary lack of electricity. You usually just have to go inland just enough to get to higher ground and sturdier buildings. That may simply be 5 miles inland for you. It may be 100. The closer you remain, the easier to get back and help with recovery efforts--which hopefully won't be needed--in your area.

Correct me if I'm wrong, but won't 155+ mph winds cause roof failure and structural problems of even well built homes?

[Steve]

That's not far off the TVCN consensus - which also includes COAMPS and HWRF. Not sure what GHMI is though.

TVCN / TVCE / TVCA Variable Consensus of AVNI, CTCI, EGRI, EMXI, GHMI, and HWFI Model Track Forecasts

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

Read your local NWS/NOAA statements. They are the only ones that will really be able to address your local concerns. It hasn't landfalled yet, and no one knows what path it may take or angle of approach for sure. You'll be the best judge along with your local government meteorologists. There are too many possibilities to address at this point and local conditions could vary wildly from Cat 4 to generally bad weather.

[ColdFusion]

Correct me if I'm wrong, but won't 155+ mph winds cause roof failure and structural problems of even well built homes?

What the NHC says about damage that can be caused by a CAT 5

Catastrophic damage will occur:

A high percentage of framed homes will be destroyed, with total roof failure and wall collapse.

Fallen trees and power poles will isolate residential areas.

Power outages will last for weeks to possibly months.

Most of the area will be uninhabitable for weeks or months.

[TreasureIslandFLGal]

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

You don't evacuate from the winds unless you are in an unsafe/unsturdy structure like a mobile home or old construction prior to Andrew 92 building codes and no additional mitigation has been done. i.e. windows are not hurricane rated and roof has no strapping. Otherwise, you evacuate to get out of the way of storm surge and out of flood plains and known flooding zones.
And what many do is evacuate way too far away! You don't have to go hundreds of miles, unless you are trying to avoid all possible impacts and a temporary lack of electricity. You usually just have to go inland just enough to get to higher ground and sturdier buildings. That may simply be 5 miles inland for you. It may be 100. The closer you remain, the easier to get back and help with recovery efforts--which hopefully won't be needed--in your area.

Correct me if I'm wrong, but won't 155+ mph winds cause roof failure and structural problems of even well built homes?

opinion only, though I've been an emergency coordinator for a few companies over the years:

yeah, that kind of wind is beyond what most building codes could even attempt to ensure. IF the storm goes up the spine initially as a strong 4/borderline 5, I would expect the front right quadrant to still bear up to cat 3 winds all the way up in Orlando. So far up still, simply because the southern part of the state is very wet/swampy and flat. We've seen storms strengthen over south florida while traversing! But eventually heading north goes over drier land and weakening will occur. It would still be a hairy ride out for Miami evacuees going to Orlando, but less life threatening than staying put and dealing with cat 4/5 winds there if not in a very sturdy building.
After Andrew, much of Miami area had to be rebuilt, and it was supposed to be done much stronger to withstand big storms. It is possible that simply going north, to areas that didn't have to do serious rebuilding recently, that you could find yourself inland in a "safer" place away from the coast, but it being only able to handle a weaker storm, as it is older construction.
IF southerners evacuate north, they should be sure that wherever they intend to go is rated to withstand a strong storm, and also isn't in a flood prone area.

All should follow local govt guidance and NHC for official info. I'm just a storm enthusiast.

[SunnyThoughts]

Gfs rolling

[chris_fit]

12z GFS... +12hrs

[shawn6304]

I've asked this a few times but haven't had a response yet. Maybe you can help...

If the storm hits as a cat 4/5 and goes straight up the middle of the state, how far up should people consider evacuating. Will the winds still be terrible and potentially life threatening as far up as say, Orlando or Tampa?

I'm not sure anyone has a good answer. My AMATEUR opinion is that once onshore the winds may be near hurricane strength for a while but then mostly gusts as it winds down. Wilma was a good example of a very fast moving storm that raked Florida both with winds and forward speed. What will this storm do ... I'm not sure we have any good examples. Again, reminder my opinion is amateur.

Hi Tolakram , I know you didn't mean it was weak and thank you for your help in answering questions , but let me tell you after having wilma go directly over my house it felt like a lot more then just a "Rake" that storm was pretty intense for the area it hit directly.

[ronjon]

That's not far off the TVCN consensus - which also includes COAMPS and HWRF. Not sure what GHMI is though.

TVCN / TVCE / TVCA Variable Consensus of AVNI, CTCI, EGRI, EMXI, GHMI, and HWFI Model Track Forecasts

TVCN has been most accurate I believe. Following it heavily. Not liking how it goes right up the middle of the state

NHC only made slight N adjustment to the 5 day and I think that means they are still leaning on Euro even though other guidance has shifted a bit E...

The NHC utilizes more tools then we see with our model runs. They do heavily weight the European model.

The new NHC track forecast is close to the
HFIP corrected consensus model and is very similar to the previous
forecast.

[Blown Away]

12z GFS Initialized at @16.7... Irma closer to 16.9, likely not an issue, not sure...