ATL: IRMA - Post-Tropical - Discussion

[Aric Dunn]

Well it does look as though that outer eyewall is a full circle now, however I heard last night the same thing

the inner one keeps fighting back..

Does her inner look to be fighting with the outer now that it has come full circle? Pretty sure you had posted that radar loop of it lol.

no its dead just getting a few last bursts in there..

[Steve]

Y'all sticking around/sheltering in place centralflamama?

[Extratropical94]

USAF 40
URNT15 KNHC 081534
AF304 2111A IRMA HDOB 40 20170908
152400 2124N 07329W 6969 03144 0042 +094 +053 174065 065 049 000 03
152430 2126N 07329W 6968 03142 0042 +092 +052 173065 066 049 000 03
152500 2128N 07329W 6967 03142 0040 +095 +051 174066 066 049 000 03
152530 2131N 07330W 6968 03141 0039 +095 +049 174066 067 049 000 03
152600 2133N 07330W 6970 03139 0037 +096 +048 174067 068 049 000 00
152630 2135N 07330W 6968 03141 0033 +100 +047 173068 068 048 000 00
152700 2137N 07331W 6969 03139 0031 +100 +047 172068 069 046 000 00
152730 2140N 07331W 6968 03139 0031 +100 +046 171069 069 047 000 00
152800 2142N 07332W 6970 03137 0031 +100 +046 170069 069 048 000 00
152830 2144N 07332W 6969 03137 0031 +099 +045 170069 069 048 000 03
152900 2147N 07332W 6968 03138 0030 +100 +044 170069 069 047 000 03
152930 2149N 07333W 6970 03135 0029 +100 +043 169068 069 049 000 00
153000 2151N 07333W 6967 03138 0029 +099 +042 168069 070 049 000 00
153030 2154N 07334W 6967 03138 0031 +097 +042 166070 071 048 000 00
153100 2156N 07334W 6970 03135 0029 +098 +041 166070 071 049 000 00
153130 2158N 07335W 6967 03136 0019 +106 +040 165069 070 049 000 00
153200 2201N 07336W 6967 03136 0026 +101 +039 164069 070 048 000 00
153230 2203N 07336W 6970 03134 0029 +100 +038 163070 070 049 000 00
153300 2205N 07337W 6967 03138 0022 +105 +038 162068 069 049 001 00
153330 2208N 07337W 6967 03139 0024 +105 +037 162069 069 050 001 00

[Hurricane Andrew]

the inner one keeps fighting back..

Does her inner look to be fighting with the outer now that it has come full circle? Pretty sure you had posted that radar loop of it lol.

no its dead just getting a few last bursts in there..

Are you sure? Look at the IR? This fighting could keep her weaker for a longer period of time, no? Irma's cloud tops have warmed over the previous hour, interesting.

[meriland29]

the inner one keeps fighting back..

Does her inner look to be fighting with the outer now that it has come full circle? Pretty sure you had posted that radar loop of it lol.

no its dead just getting a few last bursts in there..

Im surprised not many have picked up on that yet, that is a very big deal.

[GCANE]

Ouch!
CAPE building up to 4000 in the Keys

[Aric Dunn]

Does her inner look to be fighting with the outer now that it has come full circle? Pretty sure you had posted that radar loop of it lol.

no its dead just getting a few last bursts in there..

Are you sure? Look at the IR? This fighting could keep her weaker for a longer period of time, no? Irma's cloud tops have warmed over the previous hour, interesting.

look at radar.. this often happens. the inner is dead..

http://www.met.inf.cu/asp/genesis.asp?T ... AXw01a.gif

[mrbagyo]

Irma also never appeared like a "CINAMMON ROLL" despite experiencing a lot of EWRC - it's as if the core has somewhat developed an immunity from dry air intrusion.

[Steve]

Does her inner look to be fighting with the outer now that it has come full circle? Pretty sure you had posted that radar loop of it lol.

no its dead just getting a few last bursts in there..

Are you sure? Look at the IR? This fighting could keep her weaker for a longer period of time, no? Irma's cloud tops have warmed over the previous hour, interesting.

Not the model thread, but GFS running now doesn't see it. Out to 30 Hours, it's got it back down to 919mb which is about 6mb drop in 6 hours. 36H is out now, but I haven't clicked it yet....Holy ****. 906mb. That's as low as it's likely to get before starting to creep back up on the model. I'd predict it will have it a few mb's higher when the 42 hour plot comes in in a few minutes.

GFS 12Z 36 Hours
https://www.tropicaltidbits.com/analysi ... 0&ypos=293

[znel52]

Ouch!
CAPE building up to 4000 in the Keys

That is one big ole eye forming. Gonna look like Isabel when that thing opens up.

[Evil Jeremy]

Breathing a little easier this morning, but only barely. Still bracing for a direct impact, as everyone in SFL, along both coasts should be doing.

[petit_bois]

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

Major Hurricane Irma [11L]
Track, Intensity, and Impact [TI2] Guidance
15z, September 18, 2017
$$

Current Information (11am, NHC, 6hr trend in parenthesis)
Winds: 130kts / 150mph
Pressure: 927mb
Movement: WNW (285) at 14mph

Track
Irma will continue to move on a west-northwesterly heading over the next twenty-four or so hours, and the center may pass within just a couple miles of the Cuban coastline. Beyond twenty-four hours, Irma will begin to feel the influence of an upper-level trough located in the northeastern United States, and model guidance unanimously agrees that at some point, Irma will turn to the north. Model consensus is fairly high, although shifting, that Irma’s center will make landfall in southern Florida, before tracking on a north-northwesterly heading into Georgia. After that, the guidance diverges on the eventual fate of Irma’s remnants.

Uncertainty remains on several extremely important details. How close will Irma come to Cuba? When will Irma turn to the north? How much time will the storm have over the boiling hot waters of the Florida Straight? These are things that, unfortunately, we may not know a real answer to, beyond an estimate, until they happen.

Intensity
11am Friday [Current] - 130kts / 150mph
11am Saturday [+24] - 135kts / 155mph
(Landfall Intensity - 145kts / 165mph)
11am Sunday [+48] - 120kts / 135mph
11am Monday [+72] - 70kts / 80mph
11am Tuesday [+96] - 30kts / 40mph
11am Wednesday [+120] - 25kts / 30mph

If the track of Irma is somewhat uncertain, the intensity is doubly so. The storm maintained category five intensity for a record length of time, but weakened to a still-catastrophic category four early this morning while undergoing an eyewall replacement cycle, or EWRC. This EWRC appears to be complete, and the model consensus shows pressures ceasing to rise by later tonight, and dropping during the day Saturday and all the way up until landfall. The next forty-eight hours will bring Irma’s core over an area of extremely high ocean heat content, with sea surface temperatures ranging from 30 to 32 degrees celcius. Shear will be minimal until landfall, and dry air should not have an impact until after the +48 forecast period.

The only factor that I can see keeping a lid on Irma is a major one; land interaction. Should the hurricane actually make landfall in Cuba, it is possible it may weaken further, perhaps to a category three hurricane. It will then have twelve to eighteen hours over the Florida Straight, more than enough time to regain strength should any further EWRCs fail to materialize. It is worth noting that should the models shift even further west, additional time will be allotted to this hurricane to strengthen, if only a few hours, an effect that would likely be offset by increased land interaction.

Even a category three landfall will have devastating effects across southern Florida. Hurricanes Katrina, Rita, and Wilma were category three storms at their time of landfall. Category four strikes include Hugo, Charley, and Ivan. For an example of category five effects, look at Andrew, or even Irma’s own effects in the Lesser Antilles.

Make no mistake, this storm will have an extreme effect, no matter if it landfalls as a three, a four, or a five. Irma’s size has increased drastically over the past two days, and nearly all of the Florida Peninsula can be expected to experience hurricane force gusts at a minimum.

Impact
Hurricanes have many different impacts, all deadly and heavily damaging, including heavy rain, storm surge flooding, high winds, conventional severe weather, and overall infrastructural damage. Below are summaries for three different zones. Note that these zones can change at any time before and during the event, and this should NOT be used as an evacuation guide.

EXTREME IMPACT
Sustained winds of 100-130mph, with higher gusts.
Heavy coastal flooding from storm surge, especially on the western coast. Flooding may be accentuated by heavy waves.
Rainfall totals of ten or more inches, with hourly rates of one to two inches or higher possible during the peak of the storm.
Flash flooding and street flooding is possible to likely, especially in places with poor drainage, as well as low-lying areas and known flood zones.
Widespread, extended power outages are all but inevitable.
Many areas will be impassable for days or even weeks, especially closer to the coast. Some areas may become uninhabitable for an extended period of times.

SEVERE IMPACT
Sustained winds of 70-100mph, with higher gusts, especially in the southern and eastern portions of the zone.
Significant coastal surge flooding, especially on the western coast. Flooding may be accentuated by heavy waves.
Rainfall totals of six or more inches, with hourly rates of one to two inches or higher possible during the peak of the storm.
Flash flooding and street flooding is possible, especially in places with poor drainage, as well as low-lying areas and known flood zones.
Widespread power outages are likely, and power may remain out for an extended period of time.
Many areas will be impassable for days due to debris, standing water, etc.

SIGNIFICANT IMPACT
Sustained winds of 40-70mph, with higher gusts possible, especially of Irma retains her strength further inland than expected.
Moderate coastal surge flooding is possible in coastal areas, along with heavy wave action.
Rainfall totals of six or more inches, with hourly rates of one to two inches or higher possible during the peak of the storm.
Flash flooding and street flooding is possible, especially in places with poor drainage, as well as low-lying areas and known flood zones.
Scattered to widespread power outages are possible, and power may remain out for several days.


Notes
Emergency response will be hindered, if not rendered impossible, both during and after the event throughout much of eastern and southern Florida. If you haven’t evacuated and want to do so, the time is NOW! Every hour, this storm moves closer to landfall.
Focusing on an exact track is pointless; the swath of hurricane force winds is well over a hundred miles wide, and the swath of tropical storm force winds is triple that. No matter where Irma makes landfall, most of the state will see significant to major effects.
Should Irma make landfall as a category five, the wind and infrastructural impacts in the “EXTREME” zone may be higher than stated above. At this point, residents of southern and southeastern Florida should expect a crippling strike.
This storm is an imminent threat to life. Get out, or get safe.

Can't figure out how to upload an image...imageshack is no longer free.

I wonder if Irma is going onshore of Cuba and struggles to get off the coast for 12-20 hrs. this could possible take her down to Cat 2 or weaker. Hopefully not to recover. Weaker storms tend to move more westerly as well. Possible good news for Miami, not so good for Cuba. Prayers for all involved.

[Steve]

Breathing a little easier this morning, but only barely. Still bracing for a direct impact, as everyone in SFL, along both coasts should be doing.

Look again. I was wrong. GFS still intensifying up to landfall. It's got 898 which is likely too low but gives you the idea. For argument's sake, it's academic if the gusts are 135 or 145. Yeah, 145mph is worse, but does it matter? Looks destructive for both sides of the southern peninsula in my opinion. It would have to get out to the western keys or Dry Tortugas (which it won't get that far) to really cut you very much slack in FTL. Be safe EJ.
https://www.tropicaltidbits.com/analysi ... 0&ypos=293

[norva]

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

Major Hurricane Irma [11L]
Track, Intensity, and Impact [TI2] Guidance
15z, September 18, 2017
$$

Current Information (11am, NHC, 6hr trend in parenthesis)
Winds: 130kts / 150mph
Pressure: 927mb
Movement: WNW (285) at 14mph

Track
Irma will continue to move on a west-northwesterly heading over the next twenty-four or so hours, and the center may pass within just a couple miles of the Cuban coastline. Beyond twenty-four hours, Irma will begin to feel the influence of an upper-level trough located in the northeastern United States, and model guidance unanimously agrees that at some point, Irma will turn to the north. Model consensus is fairly high, although shifting, that Irma’s center will make landfall in southern Florida, before tracking on a north-northwesterly heading into Georgia. After that, the guidance diverges on the eventual fate of Irma’s remnants.

Uncertainty remains on several extremely important details. How close will Irma come to Cuba? When will Irma turn to the north? How much time will the storm have over the boiling hot waters of the Florida Straight? These are things that, unfortunately, we may not know a real answer to, beyond an estimate, until they happen.

Intensity
11am Friday [Current] - 130kts / 150mph
11am Saturday [+24] - 135kts / 155mph
(Landfall Intensity - 145kts / 165mph)
11am Sunday [+48] - 120kts / 135mph
11am Monday [+72] - 70kts / 80mph
11am Tuesday [+96] - 30kts / 40mph
11am Wednesday [+120] - 25kts / 30mph

If the track of Irma is somewhat uncertain, the intensity is doubly so. The storm maintained category five intensity for a record length of time, but weakened to a still-catastrophic category four early this morning while undergoing an eyewall replacement cycle, or EWRC. This EWRC appears to be complete, and the model consensus shows pressures ceasing to rise by later tonight, and dropping during the day Saturday and all the way up until landfall. The next forty-eight hours will bring Irma’s core over an area of extremely high ocean heat content, with sea surface temperatures ranging from 30 to 32 degrees celcius. Shear will be minimal until landfall, and dry air should not have an impact until after the +48 forecast period.

The only factor that I can see keeping a lid on Irma is a major one; land interaction. Should the hurricane actually make landfall in Cuba, it is possible it may weaken further, perhaps to a category three hurricane. It will then have twelve to eighteen hours over the Florida Straight, more than enough time to regain strength should any further EWRCs fail to materialize. It is worth noting that should the models shift even further west, additional time will be allotted to this hurricane to strengthen, if only a few hours, an effect that would likely be offset by increased land interaction.

Even a category three landfall will have devastating effects across southern Florida. Hurricanes Katrina, Rita, and Wilma were category three storms at their time of landfall. Category four strikes include Hugo, Charley, and Ivan. For an example of category five effects, look at Andrew, or even Irma’s own effects in the Lesser Antilles.

Make no mistake, this storm will have an extreme effect, no matter if it landfalls as a three, a four, or a five. Irma’s size has increased drastically over the past two days, and nearly all of the Florida Peninsula can be expected to experience hurricane force gusts at a minimum.

Impact
Hurricanes have many different impacts, all deadly and heavily damaging, including heavy rain, storm surge flooding, high winds, conventional severe weather, and overall infrastructural damage. Below are summaries for three different zones. Note that these zones can change at any time before and during the event, and this should NOT be used as an evacuation guide.

EXTREME IMPACT
Sustained winds of 100-130mph, with higher gusts.
Heavy coastal flooding from storm surge, especially on the western coast. Flooding may be accentuated by heavy waves.
Rainfall totals of ten or more inches, with hourly rates of one to two inches or higher possible during the peak of the storm.
Flash flooding and street flooding is possible to likely, especially in places with poor drainage, as well as low-lying areas and known flood zones.
Widespread, extended power outages are all but inevitable.
Many areas will be impassable for days or even weeks, especially closer to the coast. Some areas may become uninhabitable for an extended period of times.

SEVERE IMPACT
Sustained winds of 70-100mph, with higher gusts, especially in the southern and eastern portions of the zone.
Significant coastal surge flooding, especially on the western coast. Flooding may be accentuated by heavy waves.
Rainfall totals of six or more inches, with hourly rates of one to two inches or higher possible during the peak of the storm.
Flash flooding and street flooding is possible, especially in places with poor drainage, as well as low-lying areas and known flood zones.
Widespread power outages are likely, and power may remain out for an extended period of time.
Many areas will be impassable for days due to debris, standing water, etc.

SIGNIFICANT IMPACT
Sustained winds of 40-70mph, with higher gusts possible, especially of Irma retains her strength further inland than expected.
Moderate coastal surge flooding is possible in coastal areas, along with heavy wave action.
Rainfall totals of six or more inches, with hourly rates of one to two inches or higher possible during the peak of the storm.
Flash flooding and street flooding is possible, especially in places with poor drainage, as well as low-lying areas and known flood zones.
Scattered to widespread power outages are possible, and power may remain out for several days.


Notes
Emergency response will be hindered, if not rendered impossible, both during and after the event throughout much of eastern and southern Florida. If you haven’t evacuated and want to do so, the time is NOW! Every hour, this storm moves closer to landfall.
Focusing on an exact track is pointless; the swath of hurricane force winds is well over a hundred miles wide, and the swath of tropical storm force winds is triple that. No matter where Irma makes landfall, most of the state will see significant to major effects.
Should Irma make landfall as a category five, the wind and infrastructural impacts in the “EXTREME” zone may be higher than stated above. At this point, residents of southern and southeastern Florida should expect a crippling strike.
This storm is an imminent threat to life. Get out, or get safe.

Can't figure out how to upload an image...imageshack is no longer free.

I Hope Irma is going onshore of Cuba and struggles to get off the coast for 12-20 hrs. this could possible take her down to Cat 2 or weaker. Hopefully not to recover. Weaker storms tend to move more westerly as well. Possible good news for Miami, not so good for west coast. Prayers fro all involved.

And what about the people in Cuba?

[Jevo]

For those thinking SE Florida is out of the woods.

 https://twitter.com/johnmoralesnbc6/status/906169685993021440

Agree, but if this track continues to shift W at some point you can at least report what the reality is.

Id venture to say with .5 degree shifts that the NHC is pretty much zeroed in... John is pretty unfiltered. Even the new track has Cat 2/3 winds over Metro SE FL

[AutoPenalti]

Any update on Irma?

[Extratropical94]

USAF 41
URNT15 KNHC 081544
AF304 2111A IRMA HDOB 41 20170908
153400 2210N 07338W 6967 03138 0024 +105 +037 162070 071 050 000 00
153430 2212N 07339W 6966 03140 0021 +105 +037 160071 072 049 000 00
153500 2215N 07339W 6967 03138 0029 +100 +036 158072 073 049 000 00
153530 2217N 07340W 6970 03134 0036 +094 +036 156074 075 049 000 00
153600 2219N 07340W 6970 03134 0029 +099 +034 158073 073 049 000 03
153630 2221N 07341W 6970 03134 0029 +100 +033 157073 074 049 001 00
153700 2224N 07342W 6967 03138 0030 +100 +032 155073 074 050 000 00
153730 2226N 07342W 6970 03133 0027 +101 +032 153073 074 049 000 00
153800 2228N 07343W 6967 03139 0031 +100 +032 152073 074 050 000 00
153830 2231N 07344W 6969 03136 0033 +097 +032 151072 073 051 000 03
153900 2233N 07345W 6967 03136 0033 +096 +033 148072 073 051 000 00
153930 2235N 07345W 6968 03136 0032 +098 +033 148071 072 051 000 00
154000 2238N 07346W 6974 03130 0029 +103 +033 147070 071 051 000 03
154030 2240N 07346W 6963 03145 0032 +099 +034 146070 071 050 002 03
154100 2242N 07346W 6965 03144 0040 +095 +035 146070 071 /// /// 03
154130 2243N 07345W 6965 03143 0034 +098 +035 145067 068 /// /// 03
154200 2246N 07346W 6970 03138 0038 +095 +036 144068 068 /// /// 03
154230 2247N 07348W 6967 03139 0031 +099 +036 142067 068 /// /// 03
154300 2246N 07349W 6967 03139 0032 +098 +037 141066 068 /// /// 03
154330 2245N 07351W 6969 03133 0030 +096 +037 143070 072 /// /// 03

[Aric Dunn]

besides the fact that the eye is huge and eyewall will still be over miami ( which is worse) not sure what all the sighs of relief are ?

Also remember that becasue of the angle of approach even a slight wobble to the nne for an hours greatly increases risks up the coast to areas like west palm..

so just act like its coming right at you and you wont be surprised..

[weathaguyry]

My fear is that if the eye goes just west of Miami/Ft.Lauderdale, they have to deal with an extended period of time in the NE quadrant, and the right eyewall

[Steve]

My fear is that if the eye goes just west of Miami/Ft.Lauderdale, they have to deal with an extended period of time in the NE quadrant, and the right eyewall

Looks like a good 10-12 hours on the now running GFS.
https://www.tropicaltidbits.com/analysi ... 0&ypos=293