Major Hurricane Irma- STORM MODE

[hoosierwx]

When's the last time the NHC forecasted a category 5 landfall in the United States?

At this time frame maybe Katrina?

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[McQuackleton]

5pm Advisory.

[eyewall]

Obviousy this isn't what Tampa Bay or Key West was looking for. I guess we will obviously know once we see the northward turn. Obviously the window has essentially closed on Irma avoiding a US landfall. 

[Walrus]

Past 3 hours

[Jim Marusak]

7 minutes ago, eyewall said:

Obviousy this isn't what Tampa Bay or Key West was looking for. I guess we will obviously know once we see the northward turn. Obviously the window has essentially closed on Irma avoiding a US landfall. 

hate to say it, but if this storm goes any much further west than Tampa, you're not going to be talking about Miami damage anymore. you're talking almost worst case scenario for Tampa Bay, as their worst case has it landfall of a 4 or 5 just west/northwest of the city, bringing the storm surge right into the bay. I hope that doesn't happen, as that would paint a different narrative on Irma.

[Crazy4Wx]

18z GFS raking Cuba northern coast

[87storms]

1 hour ago, Hoosier said:

The new NHC forecast does have restrengthening into a category 5 south of the Keys, but per the discussion it seems like that is not what they are forecasting at landfall in the mainland.  In any event, if we are talking about a 150 mph storm vs a 160 mph storm, there is not much of a difference other than what shows up in the record books. 

hugo was 140mph at landfall, so either way we're talking about a destructive hurricane slicing right thru florida.

i don't know if this has been posted already, but it seems useful:

http://google.org/crisismap/2017-irma?hl=en&llbox=35.46%2C11.66%2C-40.38%2C-100.41&t=TERRAIN&layers=3%2C1340721332252%2C30%2C1%2C31%2C32%2C5%2C49%2C15%2C11%2C20%2C12%2Clayer9%2Clayer8    

[Amped]

The Tampa bay tracks at least spend more time over Cuba and probably weaken it more.

[McQuackleton]

2 minutes ago, TriPol said:

Any chance that this could head up through the mouth of Tampa Bay?

Anything in the NHC cone will be a possibility for another 24-36 hours

[Hotair]

Assuming Irma travels just West of Tampa, what is the supposed time frame of that event and would it coincide with a high or low tide? 

 

Edit: I found tide info for Tampa Bay

2017-09-10 Sun  6:17 PM EDT    2.4 feet  High Tide
2017-09-10 Sun  7:40 PM EDT   Sunset
2017-09-10 Sun 11:53 PM EDT    1.7 feet  Low Tide
2017-09-11 Mon  5:39 AM EDT    3.0 feet  High Tide
2017-09-11 Mon  7:13 AM EDT   Sunrise
2017-09-11 Mon  1:20 PM EDT    0.6 feet  Low Tide

[Chinook]

I'd just for once like to be able to understand the synoptic steering currents really well. Hurricanes sometimes undergo a turn that I don't understand. Like here, on the 24 hour GFS 250 mb map, Hurricane Irma's circulation appears to be in an extremely weak steering environment, and yet no hurricane models are indicating a completes stall or a track in random directions. Perhaps these things just like to try to get poleward (north) due to beta advection? Correct me if I am wrong.

 

[WhiteoutWX]

Eyeballing the 6 hour average motion, this definitely looks to be heading for at least some portion of the northern Cuba coast. Wobbles will be very important and any change in heading (north or south) will have large impacts as to how much strength the storm maintains as it makes the northward turn tomorrow.

[McQuackleton]

HR30 it starts heading N

[McQuackleton]

HR36 it starts heading what looks to be NW. HR42 back N

[McQuackleton]

I don't want to spam the thread, so please delete Mods if not allowed. HR42

[Crazy4Wx]

Just now, AcePuppy said:

I don't want to spam the thread, so please delete Mods if not allowed. HR42

Bombs out and puts a hurt on the keys...key west would be a spot for Josh.

[McQuackleton]

HR48

[Crazy4Wx]

According to the GFS it almost doesn't move from hr 42-48

[MattPetrulli]

Ft Myers-Naples area may sustain a major hit. Very surge prone and populated area. Beaches are lined with hotels and small businesses, especially Ft Myers beach. Have family there, they're leaving today. Went down to Ft Myers 2 years ago, very nice area and good building code as it seemed on most houses, though. 

[McQuackleton]

HR54

[Hoosier]

Ignoring the exact pressures, the 18z GFS suggests considerable deepening on approach to Florida.  As others have pointed out, some other guidance agrees with that possibility.

[winterymix]

GFS if verifies, infuriates SE FL evacuees and reshapes Tampa.

[hlcater]

8 minutes ago, Hoosier said:

Ignoring the exact pressures, the 18z GFS suggests considerable deepening on approach to Florida.  As others have pointed out, some other guidance agrees with that possibility.

Getting close enough range wise, I'm starting to seriously consider that as a possibility. It's long range deepening bias might not have as much effect, although upper 800s would be pretty darn hard to achieve.

[Crazy4Wx]

According to this run Key West is either in the eye or eye wall for 6-8 hours. At 160 mph winds...I doubt many structures can survive that.

[McQuackleton]

18Z GFS in GIF format through HR60

 

 

[Windspeed]

With the west trend, the effects of surge destruction grows for Key West and the western peninsula. Irma's modeled forward motion combined with the shape of the Cuban coastline forces sea level rise into the Florida Straits and trench first from all points east. Keep in mind, surge threat was always going to be great given the extensive size of Irma's circulation regardless of the exact landfall position with respect to S. Florida. But when you allow for the large core to come from more southeasterly position across the straits and add a further western component, the right angle turn devestates Key West and points north up the SW Florida coastline. The RFQ flow will focus all that extreme sea level height in the straits from greater depth right across the shallow shelf. That excessive surge has to spread out engulfing the islands. Furthermore, any further westward component adds time for Irma to remain over high SSTs and make landfall while intensifying versus just maintaining a steady state. That will only add to push surge further inland in SW Florida with RFQ onshore flow against the SW coastline. The surge experiences in areas from Naples to Port Charlotte will be beyond anything seen in historical record-keeping for those locations.

[MattPetrulli]

Does anyone else feel NHC is under doing surge estimates for a strong, large cat 4 hurricane? 

[hudsonvalley21]

3 minutes ago, Hoosier said:

Ignoring the exact pressures, the 18z GFS suggests considerable deepening on approach to Florida.  As others have pointed out, some other guidance agrees with that possibility.

I believe that the SST's are around 88-90 in that area.

[Buddy1987]

4 minutes ago, Hoosier said:

Ignoring the exact pressures, the 18z GFS suggests considerable deepening on approach to Florida.  As others have pointed out, some other guidance agrees with that possibility.

Do you happen to know if Euro shows considerable strengthening as well prior to landfall? 

[audioguy3107]

1 minute ago, NWLinnCountyIA said:

Getting close enough range wise, I'm starting to seriously consider that as a possibility. It's long range deepening bias might not have as much effect, all though upper 800s would be pretty darn hard to achieve.

I'm in full agreement with possible deepening in the Florida Straits, but that really depends on how itcan escape Cuba unscathed.  The satellite presentation at the moment isn't close to what it has been and almost half the CDO is over Cuba.  If it spends any decent amount of time there it'll be really hard for the core to reorganize in time.  We've seen what Cuba has done to past storms.