ATL : TROPICAL DEPRESSION ALEX - MODELS

[Ivanhater]

I agree KWT, if the Euro tonight flips, all bets are off. I find it interesting in the NHC disco referring to a slowdown in the BOC as the steering currents weaken. That is what the GFS does before lifting north.

[hurricaneCW]

It's also possible that Alex gets completely disrupted due to its current time over the Yucatan and reforms further north. It's also possible that Alex just dies over land although that's unlikely given its just a large system with plenty of moisture surrounding it.

[KWT]

I agree KWT, if the Euro tonight flips, all bets are off. I find it interesting in the NHC disco referring to a slowdown in the BOC as the steering currents weaken. That is what the GFS does before lifting north.

By any chance do you have a height map at 500mbs or some sort of Vorticity map for right now, I just want to see how well its handling the upper low thats in the Sw states that has recently developed.

[gatorcane]

The posts in this forum are NOT official forecast 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.org. For official information, please refer to the NHC and NWS products

I'm reading this thread here and I'm kindaof scratching my head at some of the comments. The consensus is quite good from the models that this is Mexico-bound. Okay so the (old) GFS model brings it north but its the 18Z so it doesn't have the data that the 00Z and 12Z have. The CMC is junk for tropical cyclone forecasting, let's face it. That SW will be upgraded later this year and hopefully it will address some of its issues. BTW, the parallel 18Z GFS brings it into Mexico also, and that is supposed to be running improved SW. The GFDL is way right-biased as it has been for most of its projections for this system (it is not handling the ridge well in the long-range). Forecast is pretty straightforward if you ask me: through the Yucatan west, into the BOC and landfall in Mexico with a gradual slowing of forward speed as it approaches Mexico with the ridge weakening some, but enough to move it ashore. In fact the NHC is also quite confident in their forecast for track it seems reading the latest disco as they note the "reliable" ECMWF.

[rockyman]

Thanks, hurricaneCW, for reminding us about the possibility that Alex could reform off the north coast of the Yucatan after it makes landfall. I can't remember a particular storm, but I'm sure this has happened in the past.

[Ivanhater]

I agree KWT, if the Euro tonight flips, all bets are off. I find it interesting in the NHC disco referring to a slowdown in the BOC as the steering currents weaken. That is what the GFS does before lifting north.

By any chance do you have a height map at 500mbs or some sort of Vorticity map for right now, I just want to see how well its handling the upper low thats in the Sw states that has recently developed.

Here is the water vapor that really shows the trough digging in the 4 corners region.



Here is the vort map for the GFDL in 36 hours which really breaks the ridge

[Ivanhater]

The posts in this forum are NOT official forecast 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.org. For official information, please refer to the NHC and NWS products

I'm reading this thread here and I'm kindaof scratching my head at some of the comments. The consensus is quite good from the models that this is Mexico-bound. Okay so the (old) GFS model brings it north but its the 18Z so it doesn't have the data that the 00Z and 12Z have. The CMC is junk for tropical cyclone forecasting, let's face it. That SW will be upgraded later this year and hopefully it will address some of its issues. BTW, the parallel 18Z GFS brings it into Mexico also, and that is supposed to be running improved SW. The GFDL is way right-biased as it usually is. Forecast is pretty straightforward if you ask me: through the Yucatan west, into the BOC and landfall in Mexico with a gradual slowing of forward speed as it approaches Mexico with the ridge weakening some, but enough to move it ashore. In fact the NHC is also quite confident in their forecast for track it seems reading the latest disco as they note the "reliable" ECMWF.

Nothing wrong with sticking with your guns but at least put in facts. It has already been proven the CMC was the best model last year so if you say "lets face it the cmc is crap" then I guess you consider all the other models crappier

[KWT]

The CMC is junk for tropical cyclone forecasting, .

Oh dear your going to get some wrath for that statement, esp as it was the best TC model in the 3-5 day range according to the NHC!

I still think Mexico is the obvious call but there was a lot of uncertainty about where about it was going to hit and the 18z shift towards Texas has obviously thrown that door open just as we was getting strong consensus on a C.Mexico hit. FWIW I think the NHC evolution will be the right call more or less but its all part of the game to speculate really!

[gatorcane]

The CMC is junk for tropical cyclone forecasting, .

Oh dear your going to get some wrath for that statement, esp as it was the best TC model in the 3-5 day range according to the NHC!

I still think Mexico is the obvious call but there was a lot of uncertainty about where about it was going to hit and the 18z shift towards Texas has obviously thrown that door open just as we was getting strong consensus on a C.Mexico hit. FWIW I think the NHC evolution will be the right call more or less but its all part of the game to speculate really!

If the CMC had it it's way, we would have 50 tropical cyclones in the Atlantic each year. Anyway, I'm sticking to my guns and saying Mexico until I see a few runs in a row of 00Z and 12Z models (GFS/ECMWF) that say otherwise

[BigA]

The CMC may think that every year is 2005, but I think that it's pretty good for track of established systems. Not 100% sure though.

[xironman]

The CGEM can be pretty wacky with cyclogenesis, hence the crazy uncle moniker. But in calling medium term synoptic patterns, especially closer to the mid latitudes it is not that bad.

[Nederlander]

regardless, I believe the NHC will adjust its track northward on the next update.. it tends to split the difference in these situations.. the euro will be very interesting tonight..

[KWT]

The NHC will probably barely shift, its still slap bang in the middle of the two groups, any movement will really be small in the grand scheme of things, maybe a little to the north but it depends on whether they will cut the difference or go with what has happened over the past 24hrs knowing thwy've been too far north on every advisory thus far and stick with what they have?

[Nederlander]

The NHC will probably barely shift, its still slap bang in the middle of the two groups, any movement will really be small in the grand scheme of things, maybe a little to the north but it depends on whether they will cut the difference or go with what has happened over the past 24hrs knowing thwy've been too far north on every advisory thus far and stick with what they have?

I hope they stick to their guns. like others have said on here, its a little disappointing when they simply split the difference just because there are two seperate model camps.. I guess it really depends on who they have more faith in at this point, the euro or the gfs/cmc

[Ivanhater]

The NHC doesnt like to shift every time models flip. They will wait.

Gator, it is very important to research the model verification which has nothing to do with how many times a model forecast a storm to develop. Once again the CMC was the best last year.

[CYCLONE MIKE]

IH, some really good research that you did over the last few pages. Who knows maybe you could be right, maybe not, but you have shown there is still some possibility of Alex moving more north of its current forecast track. Also no telling what happens tonight as it crosses the yucatan. could bounce around and move more north could reform a center further north, who knows. As I said earlier this morning current forecast calls for a slow down tuesday into wednesday and if, big if, the trough is as strong as some models were saying and moves all the way to the gulf states things could get very interesting for the upper texas coast. Slim chance but it is still a chance.

[Ivanhater]

Early 00z dynamical models starting to split again

[Ivanhater]

[cycloneye]

Even some of the BAMS are much more north.

WHXX01 KWBC 270023
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0023 UTC SUN JUN 27 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

TROPICAL CYCLONE ALEX (AL012010) 20100627 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
100627 0000 100627 1200 100628 0000 100628 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 17.5N 88.1W 18.7N 90.0W 19.7N 91.6W 20.6N 92.8W
BAMD 17.5N 88.1W 18.4N 89.7W 19.5N 90.7W 20.4N 91.3W
BAMM 17.5N 88.1W 18.7N 89.8W 20.0N 91.0W 21.0N 91.8W
LBAR 17.5N 88.1W 18.2N 90.0W 19.5N 92.0W 20.6N 93.9W
SHIP 50KTS 61KTS 72KTS 79KTS
DSHP 50KTS 33KTS 41KTS 48KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
100629 0000 100630 0000 100701 0000 100702 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 21.0N 93.6W 21.3N 94.8W 21.1N 96.0W 20.8N 97.1W
BAMD 21.1N 91.5W 22.4N 92.5W 23.6N 93.7W 25.0N 94.1W
BAMM 21.8N 92.2W 22.8N 93.3W 23.3N 94.2W 24.1N 94.7W
LBAR 21.6N 95.7W 24.1N 98.8W 27.3N 100.4W 30.5N 99.5W
SHIP 86KTS 97KTS 96KTS 89KTS
DSHP 55KTS 66KTS 49KTS 29KTS

...INITIAL CONDITIONS...
LATCUR = 17.5N LONCUR = 88.1W DIRCUR = 285DEG SPDCUR = 9KT
LATM12 = 17.0N LONM12 = 86.2W DIRM12 = 281DEG SPDM12 = 11KT
LATM24 = 16.6N LONM24 = 83.9W
WNDCUR = 50KT RMAXWD = 15NM WNDM12 = 40KT
CENPRS = 998MB OUTPRS = 1008MB OUTRAD = 205NM SDEPTH = M
RD34NE = 90NM RD34SE = 75NM RD34SW = 30NM RD34NW = 30NM

$$
NNNN

[Ivanhater]

NHC is on the southern side of guidance now. This is exactly why you cannot say anything is certain in the tropics. Sometimes we never learn. Still plenty of time for things to change....Trough still digging