Hurricane Idalia

[beanskip]

Is there some empirical data to support all of these anecdotes about past Gulf storms that ended up east of model projections? If that were a thing, wouldn't there be a study of it or something? 

[STILL N OF PIKE]

Just checking in and looking for a quick answer 
 

Is the system still tilted 

[Chinook]

GFS 250mb winds (barbs) 250mb height (just the colors, that's pretty much all red) and MSLP (black contours)

[turtlehurricane]

We had some decent flooding rains in Miami today on the outer-edges of Idalia.

I think the coming day could be very interesting as the Hurricane makes its closest approach, probably will get alot of strong rain bands across all of Southeast Florida. The WPC forecast via the NHC says 2-4 inches of rain are coming, and NHC says we should see 35 mph gusts during the height of it.... it's just enough that they've been issuing Hurricane Local Statements for the area.

Anyone else noticing the trend that's developed, with Idalia circling back and then hitting South Florida from the east in about a week https://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2023082818&field=Sea+Level+Pressure&hour=Animation

This happened once before in my life with another TC that I don't remember off the top of my head, and it'll probably be a weak tropical storm at that point, if it happens at all.

[so_whats_happening]

12 minutes ago, beanskip said:

Is there some empirical data to support all of these anecdotes about past Gulf storms that ended up east of model projections? If that were a thing, wouldn't there be a study of it or something? 

Interaction with land mass will pull the system east or west depending on which side of the storm it is on. In this case Florida should help aid in pulling this further east in time just like it has done with past systems. Ian was an example as most models did have it near Tampa area until it wasn't. This should be the case again where we see probably some of the western most extent currently and then it slide east as we go through time. How much of the big bend gets involved how far north of Tampa it actually hits will all have to be figured out in the next day or so once we get away from land interaction around Cuba.

[NeffsvilleWx]

5 minutes ago, turtlehurricane said:

We had some decent flooding rains in Miami today on the outer-edges of Idalia.

I think the coming day could be very interesting as the Hurricane makes its closest approach, probably will get alot of strong rain bands across all of Southeast Florida. The WPC forecast via the NHC says 2-4 inches of rain are coming, and NHC says we should see 35 mph gusts during the height of it.... it's just enough that they've been issuing Hurricane Local Statements for the area.

Anyone else noticing the trend that's developed, with Idalia circling back and then hitting South Florida from the east in about a week https://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2023082818&field=Sea+Level+Pressure&hour=Animation

This happened once before in my life with another TC that I don't remember off the top of my head, and it'll probably be a weak tropical storm at that point, if it happens at all.

got some rain up here in Melbourne as well. And the local statements with bonus TS watch. Not really expecting anything more than a breezy, rainy day.

[Rtd208]

 

[Blizzard22]

Is it just me or are some of the models starting to show it a bit further west ?

[TPAwx]

GFS has landfall near Dog Island Wednesday morning

[beanskip]

WEST WEST WEST

0z GFS stays west with landfall near Alligator Point.

0z CMC makes huge jump west -- almost 100 miles -- and now is all the way over to St. Marks!

 

[Nibor]

Structure continuing to come together.

[GaWx]

1 hour ago, TradeWinds said:

Don't disagree on current consensus but GFS was not the outlier for Ian. UK and Euro were mostly the outliers. 

0Z 9/26/22 runs: (Ian made landfall Port Charlotte area at 13Z on 9/28/22)

ICON Venice
CMC Apalachee Bay
GFS Apalachee Bay
Euro Cedar Key
UKMET Port Charlotte

[Amped]

19 minutes ago, beanskip said:

WEST WEST WEST

0z GFS stays west with landfall near Alligator Point.

0z CMC makes huge jump west -- almost 100 miles -- and now is all the way over to St. Marks!

 

The CMC has more ridging off the SE coast and doesn't dig the troff in the NE nearly as much.   I understand why it shifted west of it's 12z run.  The GFS on the other hand, just randomly decided to take it west of 18z for no apparent reason

[Amped]

Latest image 12:10 EDT

[40/70 Benchmark]

2 hours ago, Floydbuster said:

I'm still reeling from the GFS and ensembles bust from last year taking Ian to the panhandle instead of Sanibel/Captiva. Whether it's Hurricane Irene 1999, Hurricane Charley 2004, Hurricane Ian 2022, they always seem to move eastward as they are influenced by the trough in the Eastern Gulf of Mexico.

Agree. 

[RU848789]

1 hour ago, so_whats_happening said:

Interaction with land mass will pull the system east or west depending on which side of the storm it is on. In this case Florida should help aid in pulling this further east in time just like it has done with past systems. Ian was an example as most models did have it near Tampa area until it wasn't. This should be the case again where we see probably some of the western most extent currently and then it slide east as we go through time. How much of the big bend gets involved how far north of Tampa it actually hits will all have to be figured out in the next day or so once we get away from land interaction around Cuba.

Can you elaborate on the physics of why a cyclone would be pulled east, relative to track forecasts, while approaching the west coast of FL?  Obviously the track moved east relative to the forecast track with Ian, especially in the last 1-2 days before landfall (which is where we are now), but one could imagine many reasons for such shifts.  Thanks.  

[USCG RS]

22 minutes ago, Amped said:

The GFS on the other hand, just randomly decided to take it west of 18z for no apparent reason

NARRATOR: The GFS was acting normally.... 

[TPAwx]

So the 4-7 for TB includes +1-2 from king tide

[negative-nao]

Makes second Land Fall at Brunswick Georgia @ hr 240 on 0ZGFS

 

[GaWx]

0Z UKMET: after the 12Z UKMET had a 65 mile NW shift to Apalachee Bay, the 0Z is similar with no more than a slight E adjustment. So, most of the 12Z 65 mile NW shift is retained on the 0Z:

TROPICAL STORM IDALIA ANALYSED POSITION : 21.8N 85.1W

ATCF IDENTIFIER : AL102023

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 29.08.2023 0 21.8N 85.1W 994 50
1200UTC 29.08.2023 12 23.6N 84.8W 993 51
0000UTC 30.08.2023 24 26.4N 85.1W 991 43
1200UTC 30.08.2023 36 29.2N 84.4W 987 47
0000UTC 31.08.2023 48 32.1N 82.5W 989 41
1200UTC 31.08.2023 60 34.0N 79.7W 994 40
0000UTC 01.09.2023 72 34.4N 76.0W 999 38
1200UTC 01.09.2023 84 34.2N 73.4W 1003 43
0000UTC 02.09.2023 96 33.4N 71.2W 1006 37
1200UTC 02.09.2023 108 30.8N 71.2W 1007 34
0000UTC 03.09.2023 120 30.9N 70.6W 1007 30
1200UTC 03.09.2023 132 30.3N 71.6W 1008 27
0000UTC 04.09.2023 144 30.2N 72.0W 1008 26
1200UTC 04.09.2023 156 CEASED TRACKING

[TriPol]

18 minutes ago, RU848789 said:

Can you elaborate on the physics of why a cyclone would be pulled east, relative to track forecasts, while approaching the west coast of FL?  Obviously the track moved east relative to the forecast track with Ian, especially in the last 1-2 days before landfall (which is where we are now), but one could imagine many reasons for such shifts.  Thanks.  

The trajectory of a tropical cyclone is predominantly governed by the ambient steering flow, a term that encapsulates the mean environmental wind field in which the cyclone is embedded. Deviations in this steering flow, such as an anomalously robust westerly component, can induce a corresponding easterly shift in the cyclone's track. Synoptic-scale anticyclonic systems also exert a significant influence on cyclone trajectory. The spatial orientation and dynamical strength of a high-pressure system situated to the north or northeast of a cyclone can act as a steering mechanism, directing the cyclone on a more westerly course. Conversely, a weakening or lateral displacement of the anticyclonic system may permit a more easterly trajectory for the cyclone. Upper-level atmospheric features, including troughs and ridges, further modulate cyclone tracks. An approaching trough from the westerly direction can effectively "capture" the cyclone, inducing a poleward and often eastward deflection from the originally forecasted path. It's imperative to acknowledge the inherent uncertainties associated with numerical weather prediction models. These uncertainties stem from various sources, including but not limited to, initial condition errors, approximations in the model's physical parameterizations, and the intrinsically chaotic nature of the atmosphere. While the fidelity of these models generally improves as the temporal proximity to the event decreases, unforeseen deviations in the cyclone's track can still manifest. Oceanic parameters, such as sea surface temperatures and underlying currents, can also exert an indirect influence on cyclone trajectory by modulating its intensity. An intensifying cyclone may interact differently with the ambient steering flow and other synoptic to mesoscale features, thereby altering its anticipated path. As the cyclone nears a landmass, the increased surface friction can induce structural changes in the cyclone's inner core, which may, in turn, result in last-minute alterations to its track. Additionally, microscale geographical features, such as bays, inlets, and even expansive urban areas, can impart localized effects on the cyclone's trajectory, although these influences are generally subordinate to the aforementioned larger-scale dynamical factors.

[Amped]

HAFS A now 933mb 131kts at landfall, at landfall close to a cat 5

[so_whats_happening]

26 minutes ago, RU848789 said:

Can you elaborate on the physics of why a cyclone would be pulled east, relative to track forecasts, while approaching the west coast of FL?  Obviously the track moved east relative to the forecast track with Ian, especially in the last 1-2 days before landfall (which is where we are now), but one could imagine many reasons for such shifts.  Thanks.  

 

5 minutes ago, TriPol said:

The trajectory of a tropical cyclone is predominantly governed by the ambient steering flow, a term that encapsulates the mean environmental wind field in which the cyclone is embedded. Deviations in this steering flow, such as an anomalously robust westerly component, can induce a corresponding easterly shift in the cyclone's track. Synoptic-scale anticyclonic systems also exert a significant influence on cyclone trajectory. The spatial orientation and dynamical strength of a high-pressure system situated to the north or northeast of a cyclone can act as a steering mechanism, directing the cyclone on a more westerly course. Conversely, a weakening or lateral displacement of the anticyclonic system may permit a more easterly trajectory for the cyclone. Upper-level atmospheric features, including troughs and ridges, further modulate cyclone tracks. An approaching trough from the westerly direction can effectively "capture" the cyclone, inducing a poleward and often eastward deflection from the originally forecasted path. It's imperative to acknowledge the inherent uncertainties associated with numerical weather prediction models. These uncertainties stem from various sources, including but not limited to, initial condition errors, approximations in the model's physical parameterizations, and the intrinsically chaotic nature of the atmosphere. While the fidelity of these models generally improves as the temporal proximity to the event decreases, unforeseen deviations in the cyclone's track can still manifest. Oceanic parameters, such as sea surface temperatures and underlying currents, can also exert an indirect influence on cyclone trajectory by modulating its intensity. An intensifying cyclone may interact differently with the ambient steering flow and other synoptic to mesoscale features, thereby altering its anticipated path. As the cyclone nears a landmass, the increased surface friction can induce structural changes in the cyclone's inner core, which may, in turn, result in last-minute alterations to its track. Additionally, microscale geographical features, such as bays, inlets, and even expansive urban areas, can impart localized effects on the cyclone's trajectory, although these influences are generally subordinate to the aforementioned larger-scale dynamical factors.

This! lol It has to do with pressures and land can produce lower pressures dayside than at night which will cause a low pressure to form over land versus over the ocean even on a small scale. Think of like a fujiwara type of effect interaction of two low pressure areas will cause them to spin around each other and landmasses can often act as the other low pressure to help this until upper levels become too much. Interaction of friction from land mass will also play a role in dragging the system in a certain direction. Remember the main goal is for the atmosphere to balance out so the usual negligible effects of friction become more prevalent in certain situations.

Thanks for taking the time to write this Tripol.

[CoralRed]

11 minutes ago, Amped said:

HAFS A now 933mb 131kts at landfall, at landfall close to a cat 5

Wow! I looked this HAFS A up and it is new, which most of you probably already knew. 

What do you all think about this prediction? It sure isn't what people down there want.

[WxSynopsisDavid]

22 minutes ago, CoralRed said:

Wow! I looked this HAFS A up and it is new, which most of you probably already knew. 

What do you all think about this prediction? It sure isn't what people down there want.

It’s plausible but this hinges on Idalia taking full advantage of the pristine environment ahead. This would indicate lack of shear upon landfall and minimal hindrance from the trough. Lastly, it would suggest Idalia does not have any eyewall replacement cycles before landfall which is plausible if forward speed increases.

[turtlehurricane]

26 minutes ago, CoralRed said:

Wow! I looked this HAFS A up and it is new, which most of you probably already knew. 

What do you all think about this prediction? It sure isn't what people down there want.

I think it's very likely to hit Category 4-5 intensity. The waters are just absolutely rocket fuel like never before, which is why the convection has been firing non-stop at full power. -- Also it got past Cuba without disruption and actually got way more organized, so now it has a solid 48 hours to rapidly intensify, when all it needs is 24 hours to hit Cat 4-5....

It's not even the best upper level environment ever. It would take alot of wind shear to stop it from going all the way though.

Eye popping out on satellite now. By the morning we will probably have a nice and big drilled-down eye https://weather.cod.edu/satrad/?parms=meso-meso1-13-24-1-50-1&checked=map&colorbar=undefined

[WxWatcher007]

34 minutes ago, CoralRed said:

Wow! I looked this HAFS A up and it is new, which most of you probably already knew. 

What do you all think about this prediction? It sure isn't what people down there want.

I think it shows what the absolute ceiling is should everything just take off between now and landfall, but it’s an outlier. 

I think it’s becoming extremely important as we get inside ~36 hours of landfall to analyze the structure and organizational pace of the system, and the inevitable wobbles that come with landfalling TCs. 

I like the NHC forecast and a landfall intensity between 105-115kt. 

[so_whats_happening]

12 minutes ago, turtlehurricane said:

I think it's very likely to hit Category 4-5 intensity. The waters are just absolutely rocket fuel like never before, which is why the convection has been firing non-stop at full power. -- Also it got past Cuba without disruption and actually got way more organized, so now it has a solid 48 hours to rapidly intensify, when all it needs is 24 hours to hit Cat 4-5....

It's not even the best upper level environment ever. It would take alot of wind shear to stop it from going all the way though.

Eye popping out on satellite now. By the morning we will probably have a nice and big drilled-down eye https://weather.cod.edu/satrad/?parms=meso-meso1-13-24-1-50-1&checked=map&colorbar=undefined

It really depends on how well the core can organize itself vertically. Definitely still some slanting going on aloft from the ULL along the Gulf coast. This should weaken a bit in the next day and I believe even some models showed it setting up a jet streak as we get close to landfall. We should know by tomorrow afternoon how well the core is stacked up. I would say cat 3 seems reasonable but if things set up just right cat 4 is attainable (cat 5 intensity is pretty difficult to attain)  with the amount energy in place.

Either way fun one to watch and really hope folks do take it serious down in Florida.

[beanskip]

Coarse maps on Euro annoyingly hard to extrapolate when the 36-hour mark is the key window. 

[GaWx]

33 minutes ago, turtlehurricane said:

I think it's very likely to hit Category 4-5 intensity. The waters are just absolutely rocket fuel like never before, which is why the convection has been firing non-stop at full power. -- Also it got past Cuba without disruption and actually got way more organized, so now it has a solid 48 hours to rapidly intensify, when all it needs is 24 hours to hit Cat 4-5....

It's not even the best upper level environment ever. It would take alot of wind shear to stop it from going all the way though.

Eye popping out on satellite now. By the morning we will probably have a nice and big drilled-down eye https://weather.cod.edu/satrad/?parms=meso-meso1-13-24-1-50-1&checked=map&colorbar=undefined

Isn't it more like 32 hours from now til landfall rather than 48 hours?