ATL: FIONA - Models

[M_0331]

If I'm reading that 12z CMC map right it's near South Florida but only 1007 mb. Is this much of a spread in intensity normal between different models? I do know intensity is the hardest thing to forecast, but..

Look at 850 mb T/SLP ON ECMWF

[cycloneye]

00z Tropical Models

Code: Select all

WHXX01 KWBC 300051
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0051 UTC MON AUG 30 2010
 
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
 
ATLANTIC OBJECTIVE AIDS FOR
 
DISTURBANCE INVEST (AL972010) 20100830 0000 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        100830  0000   100830  1200   100831  0000   100831  1200
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    14.0N  41.4W   14.6N  44.6W   15.4N  48.3W   16.6N  52.3W
BAMD    14.0N  41.4W   14.5N  44.4W   15.4N  47.6W   16.4N  50.9W
BAMM    14.0N  41.4W   14.4N  44.6W   15.2N  48.0W   16.2N  51.5W
LBAR    14.0N  41.4W   14.6N  44.7W   15.1N  48.4W   15.7N  52.2W
SHIP        25KTS          28KTS          32KTS          40KTS
DSHP        25KTS          28KTS          32KTS          40KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        100901  0000   100902  0000   100903  0000   100904  0000
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    18.5N  56.4W   24.3N  63.2W   32.7N  66.0W   41.2N  61.3W
BAMD    17.5N  54.2W   20.0N  60.7W   22.5N  65.6W   22.4N  68.9W
BAMM    17.6N  55.1W   21.3N  61.4W   25.6N  65.5W   29.3N  65.4W
LBAR    16.5N  55.9W   19.2N  62.2W   23.2N  66.8W   27.2N  66.3W
SHIP        48KTS          59KTS          62KTS          64KTS
DSHP        48KTS          59KTS          62KTS          64KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  14.0N LONCUR =  41.4W DIRCUR = 275DEG SPDCUR =  17KT
LATM12 =  13.7N LONM12 =  37.9W DIRM12 = 274DEG SPDM12 =  18KT
LATM24 =  13.5N LONM24 =  33.9W
WNDCUR =   25KT RMAXWD =   60NM WNDM12 =   25KT
CENPRS = 1007MB OUTPRS = 1012MB OUTRAD =  240NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM


[TwisterFanatic]

If I'm reading that 12z CMC map right it's near South Florida but only 1007 mb. Is this much of a spread in intensity normal between different models? I do know intensity is the hardest thing to forecast, but..

That was the CMC ensembles. They don't show intensity like the operational.

[SootyTern]

If I'm reading that 12z CMC map right it's near South Florida but only 1007 mb. Is this much of a spread in intensity normal between different models? I do know intensity is the hardest thing to forecast, but..

That was the CMC ensembles. They don't show intensity like the operational.

Ok, thanks! Trying to learn here about all the different models.

[SeminoleWind]

If I'm reading that 12z CMC map right it's near South Florida but only 1007 mb. Is this much of a spread in intensity normal between different models? I do know intensity is the hardest thing to forecast, but..

Look at 850 mb T/SLP ON ECMWF

no a pretty site thats for sure
http://raleighwx.easternuswx.com/models ... PUS240.gif

[sunnyday]

The spaghetti models show the future Fiona, if it becomes a storm, curving out to sea. So, what exactly is predicting a So Fla hit? Thank you for explaining.

[Florida1118]

Im still not holding much on the models yet. but even then Its not nice to see a storm over your home...

[Portastorm]

The spaghetti models show the future Fiona, if it becomes a storm, curving out to sea. So, what exactly is predicting a So Fla hit? Thank you for explaining.

The European operational model (i.e. ECMWF or Euro)

[Wx_Warrior]

Sunny...

The EURO & it looks now like the CMC.

[artist]

what we all have to remember that until there is an actual storm we really won't know for sure where it will go. Or even if there will be one for 100% for certain.

[sunnyday]

Thank you for explaining. One more quick question--how reliable are they, generally?

[USTropics]

Thank you for explaining. One more quick question--how reliable are they, generally?

No model is ever perfectly accurate because it is impossible to learn exactly everything about the atmosphere in a timely enough manner, and atmospheric measurements that are taken are not completely accurate. Dynamic models employ the basic laws of physics as they apply to the atmosphere to predict the future course of the storm (this process involves complex equations). The major problem with this process is the computing power and time it takes to process. For example, if the fineness of the grid points or mesh for an area the size of the globe is used with the maximum amount of data available combined with the most detailed of the models, the forecast would be as accurate as possible. However, the problem in the example stated above is in order for the computers to process the data and produce a model run, it would take up to 7 days for a 24 hour forecast. Instead, we use an ensemble method of forecasting, whether it be a multi-model ensemble, or numerous ensemble members based on the global model, helps define the uncertainty and further limit errors. The forecast models are used as a tool that an experienced forecaster will use to assemble an official track forecast.

Like all weather forecasts, track forecasts are more accurate in the short term than in the long term. Average errors for the United States National Hurricane Center are around 100, 200, and 300 nautical miles (560 km) in 1, 2, and 3 days, respectively — the source of the 1-2-3 rule — although the errors have been decreasing.

[Steve]

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

00Z Nam rolling. 18Z out to 84 had a mini-system trailing Earl in tandem to the southeast and on the eastern side of the models calling for 97L to recurve. You can compare the link above (00z) to the one below (18z) to see if it is moving toward the CMCe/Euro (and +/- BAMD) solution or if it's going to stay with the other global, tropical and dynamic models with the recurve scenario east of the Bahamas.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

Yeah, it's just NAM but it's one of the first runs out.

[terrapintransit]

GFS starting the westward bend...

[ericinmia]

Interesting that only one of the ensemble members of the GFS shows a track south of the Operational Forecast. IMHO they need to do some work on the GFS...

[Wx_Warrior]

Of course it will....It knows who's boss!

[jinftl]

I am still trying to reconcile the maps below with the ongoing dialogue about models (at least one, i gather) showing 97L being a florida and maybe even a Gulf threat. Maybe it's just that the model(s) suggesting a florida/gom threat aren't represented here. That said, I would think we would be looking for consistency not only between later runs of the same model, but also conistency between the models, esp. the more 'reliable' and 'commonly referenced ones'.

Not doubting the validity of any model data presented in this thread, just not sure how to reconcile it with published model consensus views like these. If no other reliable runs are showing a florida/gulf threat at this time, not saying that couldn't change, just not seeing it now (or not understanding what I am seeing). Any insight would be helpful for many of us I am sure!

GFS starting the westward bend...

[Steve]

The models on that chart represent some of the ones that favor recurve and 97l staying east of the Bahamas. Other solutions (European, CMC Ensembles) show a southern Bahamas threat and then maybe FL, GOM or whatever. ECMWF and CMC aren't on that chart.

[Steve]

FWIW, 00z NAM is much faster with Earl than 18z and looks to aim it at North Carolina based on the orientation that it shows. Assuming the small feature trailing to the ESE is 97L, it keeps it east which keeps the NAM in line with the models favoring recurvature.
http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[artist]

I am still trying to reconcile the maps below with the ongoing dialogue about models (at least one, i gather) showing 97L being a florida and maybe even a Gulf threat. Maybe it's just that the model(s) suggesting a florida/gom threat aren't represented here. That said, I would think we would be looking for consistency not only between later runs of the same model, but also conistency between the models, esp. the more 'reliable' and 'commonly referenced ones'.

Not doubting the validity of any model data presented in this thread, just not sure how to reconcile it with published model consensus views like these. If no other reliable runs are showing a florida/gulf threat at this time, not saying that couldn't change, just not seeing it now (or not understanding what I am seeing). Any insight would be helpful for many of us I am sure!

GFS starting the westward bend...

my understanding is all the models above are US operational models from different agencies, or many from the NHC, etc. The euro and cmc that is showing a south fl hit are not US models, thus why they are not shown above. But they do show the ukmet, and the cmc on the sfwd model plots. The euro is not on it though. Correct me guys if I am wrong.