Tropical Depression Test Messages Issued - Images Here

[wxman57]

Looks like the TPC has begun issuing tropical depression test messages for that disturbance south of Jamaica. I removed LBAR and A98 just because they're worthless and take up space. The BAMD would be the better of the two BAM models to use for this system. I do think that development is looking more likely - up to 40-50% now. Most likely a weak TS when it crosses eastern Cuba to Haiti late Friday or on Saturday morning.

.....THE FOLLOWING IS A TEST MESSAGE.....

NATIONAL HURRICANE CENTER NORTH ATLANTIC OBJECTIVE AIDS FOR

TROPICAL DEPRESSION INVEST (AL982003) ON 20031203 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS... ...36 HRS...
031203 1200 031204 0000 031204 1200 031205 0000

LAT LON LAT LON LAT LON LAT LON
BAMD 11.6N 77.3W 13.6N 77.8W 16.0N 77.6W 18.5N 76.7W
BAMM 11.6N 77.3W 13.3N 78.1W 15.1N 78.4W 16.5N 78.1W
SHIP 25KTS 28KTS 33KTS 37KTS
DSHP 25KTS 28KTS 33KTS 37KTS

...48 HRS... ...72 HRS... ...96 HRS... ..120 HRS...
031205 1200 031206 1200 031207 1200 031208 1200

LAT LON LAT LON LAT LON LAT LON
BAMD 21.0N 74.9W 27.3N 66.4W 31.9N 51.6W 28.7N 33.6W
BAMM 17.8N 77.6W 20.9N 74.6W 26.7N 65.9W 31.9N 54.2W
SHIP 41KTS 37KTS 21KTS 0KTS
DSHP 35KTS 32KTS 16KTS 0KTS

...INITIAL CONDITIONS...
LATCUR = 11.6N LONCUR = 77.3W DIRCUR = 45DEG SPDCUR = 12KT
LATM12 = 9.9N LONM12 = 78.9W DIRM12 = 52DEG SPDM12 = 13KT
LATM24 = 8.6N LONM24 = 81.2W

And as you can see (below) in the latest satellite image, we do have at least a LOWER to mid level circulation wrapping up near 12.3N/77.5W. This is just about where the GFS was forecasting development to occur. Squalls are beginning to concentrate around that point. If the squalls don't collapse again this afternoon, then I think we'll have a TD in 24 hours or so:

<img src="http://myweb.cableone.net/nolasue/disturb.gif">

Taking a look at the mean wind between 400 and 700 mb over the region, you can see why this system is going nowhere but N then NNE-NE when it develops:

<img src="http://myweb.cableone.net/nolasue/disturb400700mb.gif">

And, finally, the 200 mb flow over the top:

<img src="http://myweb.cableone.net/nolasue/disturb200mb.gif">

[MWatkins]

I thought that cloud pattern looked suspicious this morning and it looks better organized now than when first visibles came out.

Hard to see it taking much of a left turn like the BAM models are suggesting...I would think it will kick out further to the east than the track models are suggesting. One caveat though...the fresh off the press 12Z GFS suggests a significantly different solution and leaves a well-organized sustem in the SW Caribbean for a while...check out the t+84 from 12Z:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084m.gif

Gonna hafta wait a couple of more runs before jumping on that solution personally...that's a big change and a little tough to believe...

MW

[wxman57]

That link is to the ETA, not the GFS, and the ETA is completely worthless as a tropical model. The 84hr GFS has it north of the DR as a weak low:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084m.gif

[MWatkins]

Whoops.

You're right...that is from the ETA. The GFS does no such thing...I probably should have noticed that I had clicked the wrong link from the NCEP page...since the letters ETA are embedded in the link.

The 12Z GFS does no such thing.

But while I'm at it...objectively...especially in terms of intensity...the ETA is not on par with the GFS...because it does not perform well in observation-poor environments suck as the open Atlantic. However...when there is a storm in the Gulf...for example...the ETA does significantly better with the sounding/other data from the US to fill in the gaps. I'm not a big fan of the model...but it's worth noting.

In fact...the ETA model..when utilized...performes about as well as NOGAPS in terms of track errors...although it should be noted that many of the cases where the ETA has been run/verified was when systems were already on shore or close to it.

MW