ATL: MATTHEW - Models

[ConvergenceZone]

I think that out of all of the systems this year. This invest is by far
the most challenging to predict, which obviously makes it more enjoyable
or frustrating depending on how you look at it.

[ROCK]

HWRF looks plausible....

[ospreygrad]

[Poleward.

Poleward? so it could be either N or NW then....thanks...

More due north, according to that particular model run to be more specific. Just wanted to clarify.[/quote]

Just took a look and it is moving NNW with the cut off low backing off to the NW which would imply a hit on north Gulf coast..just one run so nothing to over analyze really...

HWRF sends this NW about to go through the Yucatan channel....nothing very strong but that will likely change in future runs

[/quote]

Right, that was just my observation based on that run Ivanhater. But like I mentioned earlier, more changes on the way with later runs.

[otowntiger]

GFS really struggling with the synoptics - very strange run.

How do we know it's struggling? I mean isn't it possible that it's seeing some things in the current and/ or forecast synoptics that will cause it to be very weak and/or move in such a way as not to be a serious threat? It is not at all out of the ordinary for a tropical disturbance to not intensify and wreak havoc, instead just bringing someone some gentle breezes accompanied by some sporadic rain.

When I make this comment I'm discussing the upper level environment not the strength of the tropical cyclone. What makes the GFS seem so strange is the position and strength of the cutoff low (must be a 2-3 standard deviation anomaly) compared to the other guidance (see my discussion above). I also find it somewhat spurious that the GFS devlops a second "tropical cyclone" to the east of 95L. I suppose it could come true but looks overdone to me.

Fair enough. And by the way I wasn't specifically directing my comments at you only, just that it seems if a particular model begins to show a less, shall we say sensational, type track/development then some people discount it. Disclaimer: I'm sure you and most of the posters here have a better grip on the technical aspects of tropical weather than I do. Just an observation. Now back to the weather and 95L.

[KWT]

HWRF looks plausible....

I don't think the HWRF track is likely, seems like it is way too quick to erode the upper high over the SE states and lift this system out...though obviously if this one was stronger then the models expect its possible.

[cycloneye]

Belize landfall by 12z GFDL. Here is the text.

WHXX04 KWBC 211751
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 95L

INITIAL TIME 12Z SEP 21

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 12.2 63.0 275./12.0
6 13.2 64.4 306./17.0
12 11.8 65.3 212./17.3
18 11.9 65.7 283./ 4.2
24 12.9 68.8 289./31.6
30 13.0 69.9 271./10.5
36 13.1 70.9 277./10.1
42 13.4 72.2 282./13.3
48 13.6 73.5 278./12.8
54 14.0 74.5 298./10.3
60 14.4 75.8 287./13.7
66 14.4 77.7 269./18.4
72 14.7 79.0 282./12.3
78 14.9 81.5 276./24.4
84 14.8 83.4 268./18.3
90 14.8 84.4 269./ 9.7
96 14.9 84.8 281./ 4.4
102 15.5 85.3 323./ 7.4
108 16.3 86.1 312./11.6
114 16.6 87.3 282./11.2
120 16.9 88.0 296./ 7.6
126 17.1 88.1 328./ 1.9

[ROCK]

HWRF looks plausible....

I don't think the HWRF track is likely, seems like it is way too quick to erode the upper high over the SE states and lift this system out...though obviously if this one was stronger then the models expect its possible.

plausible as in Yucatan channel..afterwards someone throw some dart from LA to FL and you got equal odds....

[MWatkins]

Belize landfall by 12z GFDL. Here is the text.

[/b]

Interesting to see the physics in the model behind the 1.5 degree jump south in the six hours between t+6 and t+12...not sure I buy that is going to happen in the next 6 hours!

0 12.2 63.0 275./12.0
6 13.2 64.4 306./17.0
12 11.8 65.3 212./17.3

MW

[KWT]

Belize landfall by 12z GFDL. Here is the text.

[/b]

Interesting to see the physics in the model behind the 1.5 degree jump south in the six hours between t+6 and t+12...not sure I buy that is going to happen in the next 6 hours!

0 12.2 63.0 275./12.0
6 13.2 64.4 306./17.0
12 11.8 65.3 212./17.3

MW

Yeah sometimes these hurricane models do throw out odd jumps on systems, it seems to jump the system too far north then try to readjust to something more realistic and sometimes overdo it in the process.

Whats also very interesting is the way the GFDL nearly stalls it from 120hrs, sure does look like steering slackens out which is going to be just joyful if that occurs, models will have trouble with any solution involving weak steering currents.

Saying that GFDL looks way more realisitic then the HWRF in the way it evolves the pattern.

[cycloneye]

Here is the animation of the 12z GFDL. Nothing strong at first run, but as Ivan said with HWRF, it wont stay that way for long.

http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

[Ivanhater]

Euro 72 hours

[cycloneye]

18z Tropical Models Suite

Notice the black line which is TVCN that NHC uses for forecast tracks.

Code: Select all

WHXX01 KWBC 211754
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1754 UTC TUE SEP 21 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 (AL952010) 20100921 1800 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        100921  1800   100922  0600   100922  1800   100923  0600
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    12.4N  64.1W   12.7N  66.3W   13.1N  68.9W   13.3N  71.4W
BAMD    12.4N  64.1W   12.6N  66.3W   12.8N  68.7W   12.9N  71.2W
BAMM    12.4N  64.1W   12.7N  66.4W   13.0N  68.9W   13.1N  71.5W
LBAR    12.4N  64.1W   12.9N  66.6W   13.4N  69.4W   13.8N  72.5W
SHIP        25KTS          32KTS          44KTS          57KTS
DSHP        25KTS          32KTS          44KTS          57KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        100923  1800   100924  1800   100925  1800   100926  1800
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    13.7N  74.1W   14.6N  79.1W   15.8N  84.2W   17.2N  87.9W
BAMD    12.8N  73.8W   13.1N  79.1W   14.4N  84.1W   16.2N  88.0W
BAMM    13.3N  74.2W   13.8N  79.6W   14.9N  84.9W   16.5N  88.6W
LBAR    14.2N  75.8W   15.1N  82.5W   14.1N  86.5W   15.5N  89.3W
SHIP        74KTS          96KTS         108KTS         114KTS
DSHP        74KTS          96KTS          65KTS          45KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  12.4N LONCUR =  64.1W DIRCUR = 275DEG SPDCUR =  13KT
LATM12 =  12.1N LONM12 =  61.6W DIRM12 = 275DEG SPDM12 =  12KT
LATM24 =  11.9N LONM24 =  59.2W
WNDCUR =   25KT RMAXWD =   60NM WNDM12 =   20KT
CENPRS = 1009MB OUTPRS = 1012MB OUTRAD =  170NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM
 
$$


[Ivanhater]

96 hours

[Ivanhater]

120 hours

[KWT]

Pretty far south there Ivanhater, obviously if the troughing is overdone who knows it may not ever lift out...but thats highly unlikely given the set-up aloft.

Still good agreement about a track into CA in about 72-96hrs, then who knows after that, maybe a slow lift out to the NW/N/NE back into the Caribbean or Gulf and then strengthening and moving NNE/NE.

[ConvergenceZone]

Pretty far south there Ivanhater, obviously if the troughing is overdone who knows it may not ever lift out...but thats highly unlikely given the set-up aloft.

Still good agreement about a track into CA in about 72-96hrs, then who knows after that, maybe a slow lift out to the NW/N/NE back into the Caribbean or Gulf and then strengthening and moving NNE/NE.

Of course as we always know, if the system develops even faster than forecasted, then the mor North it's probably going to
be pulled. I'm sure that rule applies here just like it applies in the Atlantic.

[BigA]

I don't think the the Nicaraguan/Honduran landfall is a certainty by any means, and if it happens, it may well be a clip. Still too early to say given the lack of an LLC, but my gut is that yes, it probably does strike Central America before curling northward.

[Ivanhater]

144 hours

[srainhoutx]

Actually the models are in rather good agreement concerning the shorter term focusing near Nicaragua or Honduras. Beyond that, things are not so clear.

[Wx_Warrior]

Looking back at 0z EURO 144, nearly exact location FWIW