Invest 94L,Near Windwards-Discussions

[MWatkins]

everyone, we need to stop thinking that fast movement prevents development. Did we already forget what we saw with Dean... a system moving faster than 20KT that still rapidly intensified. Also, we need to forget that weak means west. Weak means steered with the low level flow, which this time means a more northerly track

I can see some slowdown of this feature since there is little SAL; however, not much of a slowdown is likely

I am not completely sold that this is moving at 20 knots...

[cycloneye]

Mike,do you see it moving slower than 20kts?

[flwxwatcher]

Both the 00Z CMC and Euro have remarkable consistency in bringing the system to the middle Leeward Islands in 6 days. Their 6-day positions appear to be within 100 miles of each other. Looking at the 500 mb pattern, there is a large low pressure system and trough around 33N-40W in 72 hrs in the Euro model. Perhaps in these models the system is getting tugged slightly northward due to this weakness. Or they are simply reflecting a weaker Atlantic ridge than the BAMs. Both globals only slowly develop the cyclone and don't identify it as a tropical storm until 4-5 days from now.

The problem with the EURO is it is moving this system to slowly. this system would really have to put the brakes on to be at the 120 EURO position.

[Zardoz]

I am able to see hints of a surface circulation on the visible satellite this morning.

It's really apparent on the Rainbow version. A big blob of convection is also popping up.

GOES East Rainbow

It sure looks like a player, huh?

[MWatkins]

Mike,do you see it moving slower than 20kts?

It's very hard to tell. NHC has been estimating a center in the model runs...so it is hard to tell if they are catching up or if this is really moving forward that fast.

Just estimating from the last several hours of satellite imagery it just doesn't seem to me that it's moving that fast...but that's all I can really base it on at this point.

Will have a better idea later this afternoon after getting to watch visibles all day.

MW

[Weatherfreak14]

I think time will tell for 94L. to my eyes it looks not that impressive right now, but like what Derek said, It is becoming favorible for rapid intensifcation, or even slow development. I think something will probably come out of this i give it 35% right now.

[ronjon]

Looks to me from VIS SAT that there is a broad center of circulation around 11N-40.9W. The main convection is displaced slightly off to the east. Just viewing from the SAT it looks like it has a ways to go to organize into a tropical depression. I would anticipate slow development per NHC discussions. I do see some easterly shear that Mike brought up in the NE quadrant of the system.

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

[Derek Ortt]

I am fixing a center at 10.6N and 40.6W based upon the 14:15 UTC visible image, this would yield a forward speed in the 17-20KT range, but we do need more visibles to be certain

[gatorcane]

I certainly think the NHC in their next TWO in about an hour here....will mention a tropical depression could form in the next 48 hours..

this thing is definitely ramping up folks.

[Zardoz]

...to my eyes it looks not that impressive right now...

JM agrees, pretty much, but he's talking TS, possibly:

Wunderblog

None of the reliable computer models develop 94L. The system should track through the Lesser Antilles Islands on Friday, bringing gusty winds and heavy rain. I expect that the earliest 94L could become a tropical depression would be Thursday, and it is unlikely the Lesser Antilles would experience anything worse than a 50 mph tropical storm. It is more likely that 94L will still be a tropical disturbance when it passes through the Lesser Antilles.

[Meso]

None of the reliable computer models? I don't get that. The EURO is developing it and it's one of the most reliable,maybe not in projected path but with development it usually seems quite good

[gatorcane]

Interesting to note the ridge over the Southern CONUS will be breaking down in the long-term but then building back in. Should invest 94L develop, it is essential that ridge builds back in to steer this away from the northern GOM or SE US.

NWS Miami:

THE MID/UPPER LEVEL PATTERN STARTS TO CHANGE WEDNESDAY AS THE
MID/UPPER RIDGES RETROGRADE WEST AND A SHARP TROUGH MOVES INTO THE
NE CONUS. MOST MODELS...ESPECIALLY GFS/NAM/UKMET AGREE THAT A
SEPARATE UPPER LOW WILL FORM OFF THE CAROLINA COAST WEDNESDAY AND
REMAIN NEARLY STATIONARY. THIS WILL DRAG A WEAK TROUGH AXIS INTO
SOUTH FL WEDNESDAY NIGHT AND THURSDAY...WHICH WILL THEN LINGER
ACROSS THE REGION AS A BREAK IN THE SUBTROPICAL RIDGE INTO EARLY
SATURDAY BEFORE LIFTING OUT AND ALLOWING THE UPPER RIDGE AXIS TO
BUILD BACK OVERHEAD. AT THE SURFACE...MODELS INDICATE A SURFACE
REFLECTION OF THE UPPER LOW FORMING AND MEANDERING OFF THE NE FL
COAST...AND AN ASSOCIATED SURFACE TROUGH MOVING SOUTH THROUGH THE
FL PENINSULA LATE WEDNESDAY AND INTO THURSDAY. EXACT POSITION OF
THIS TROUGH IS UNCLEAR AT THIS TIME...AS NAM AGGRESSIVELY MOVES IT
INTO THE FL STRAITS ON THURSDAY WHILE THE GFS STALLS IT NEAR LAKE
OKEECHOBEE FOR SEVERAL DAYS WHILE DEVELOPING SEVERAL WEAK SURFACE
WAVES ALONG IT. THIS LEADS TO A SOMEWHAT UNCERTAIN FORECAST BEYOND
THURSDAY. IN GENERAL HOWEVER...A GRADUAL INCREASE IN POPS AND MORE
UNIFORM COVERAGE OF CONVECTION CAN BE EXPECTED AS MID LEVEL
MOISTURE WILL BE ON THE INCREASE WITH PWATS INCREASING TO AROUND
2.25 INCHES...AND SURFACE WINDS SHIFT TO THE S OR SW WITH ALMOST NO
MID LEVEL STEERING FLOW. THESE FACTORS SUGGEST HEAVY RAINFALL
WILL BE A THREAT WITH SLOW MOVING THUNDERSTORMS THURSDAY AND
FRIDAY AT THE VERY LEAST...IF THE GFS SOLUTION PANS OUT WITH THE
STALLED SURFACE BOUNDARY.

[gatorcane]

and also note that all of the global models are forecasting a weaker southern CONUS ridge out at 144 hours....

a track like Dean is less likely in my opinion

http://moe.met.fsu.edu/tcgengifs/

[hurricanetrack]

If the ridge builds back in, then it would be steered away by means of a southern track- not out to sea. Is that what was meant by your idea above?

Otherwise, if it is too far north already, then in it comes to the SE US, FL or GOM. Otherwise a building ridge, if the cyclone were far enough south like Dean, would send this in to Cenrtal America once again.

[wxman57]

I did get a 24hr movement of 18 kts using 12Z to 12Z satellite positions.

[EyELeSs1]

I am fixing a center at 10.6N and 40.6W based upon the 14:15 UTC visible image, this would yield a forward speed in the 17-20KT range, but we do need more visibles to be certain

Does the SHIPS model take into account the forward speed of the disturbance when it states 11knts of SE shear??

Just trying to figure out if this is still under 11knts of 'actual' SE shear while moving at 15-20knts towards the West or does this shear become negligible due to it's fast forward motion.

[canegrl04]

Timing is everything. We will know soon if this is a US threat. I think this is either a fish,or a FLA storm.When's the next GFS model?

[Brent]

11:30am TWO:

A TROPICAL WAVE AND A BROAD AREA OF LOW PRESSURE LOCATED ABOUT
MIDWAY BETWEEN AFRICA AND THE LESSER ANTILLES ARE PRODUCING
DISORGANIZED SHOWERS AND THUNDERSTORMS. ENVIRONMENTAL CONDITIONS
ARE FAVORABLE FOR SOME DEVELOPMENT AS THIS SYSTEM MOVES WESTWARD AT
15 TO 20 MPH.

I think it looks a lot better on satellite today.

['CaneFreak]

does anyone see this thing trying to re-establish itself further north or is this just an illusion by the convection moving on satellite? Center looks to me to be even closer to 11 North as of right NOW.

[gatorcane]

Timing is everything. We will know soon if this is a US threat. I think this is either a fish,or a FLA storm

Way too early to say FLA or fish storm. What is your reasoning behind that statement?