South Caribbean firing

[O Town]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUN 11 2007


A SECOND CARIBBEAN SEA TROPICAL WAVE IS ALONG 82W/83W SOUTH OF
16N MOVING WEST 10 TO 15 KT. IT IS NOT EASY TO KNOW IF THIS WAVE
IS ENHANCING ANY PRECIPITATION. SHOWERS AND THUNDERSTORMS FROM
14N TO 19N WEST OF 80W ARE PROBABLY MORE RELATED TO THE WESTERN
CUBA MIDDLE TO UPPER LEVEL TROUGH. OTHER PRECIPITATION IN THE
SOUTHWESTERN CORNER OF THE AREA AREA MAY BE RELATED TO THE ITCZ.

[Aric Dunn]

from the looks of the latest gfs.. the system that the gfs possibly forms off the Yucatan in 5 days (which is iffy going out that far)actually originates in the sw carrib ! just about where we have that present burst of convection .. or a little further south where we have more cyclonic turning. now given the fact that the convection in the western gulf has easterly trade winds blowing right thru it, i would not think we would see a low develop there but rather further south. interesting to note that we have a possible tutt feature taking shape and the upper environment in the western carrib may become quite favorable in the next day or so. i would expect to see development in the Caribbean where then it would move north into the gulf . since the present trend is for at the least maintain or increase the convection in the western gulf, if we see a low trying to develop anywhere around it we could see development sooner rather than later. although if today is anything like the last couple of days i imagine we will see the convection weaken and shift westward with the upper low and redeveloping right where we the most difluent flow aloft on the back side of that low. as of right now and the immediate future being the next 24 to 36 hours the gulf is shut off for tropical development! until that upper low moves far enough west or pulls out but if we see the upper low move out the time that it would take for the environment to become more conducive would increase and we would likely lose the present lifting going on. we would want to see the upper low continue west allowing and favorable area in the western carrib so that we can get a low to form that would drift north and west with the upper low and eventually possibly making it into the gulf.

and actually as i was writing that .. i saw the 6z gfs ( although the 6z and 18z models are normally run with the same old data from the 00zand the 12z ) the gfs develops the low in the nw carrib and brings it up over Florida. and that is what was expected since its out nearly five days and the Caribbean has a general lower pressure field the gfs is spinning up lows all the time it wont get a handle on it till something starts taking shape.

[Extremeweatherguy]

Houston NWS office mentions the caribbean in their morning AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
451 AM CDT MON JUN 11 2007

.DISCUSSION...
NOT TO SOUND LIKE A BROKEN RECORD BUT IT LOOKS AS THOUGH TODAY
WILL BE MUCH LIKE SUNDAY. HIGHS IN THE LOWER TO MID 90S...LOWS IN
THE 70S. BEST RAIN CHANCES AGAIN WILL BE IN THE EAST FROM HIGH
ISLAND NORTH TO LIVINGSTON AND CROCKETT. LAKE BREEZES MAY AGAIN
ENHANCE RAIN CHANCES OVER POLK-SAN JACINTO-TRINITY-HOUSTON
COUNTIES. STORM MOTIONS WILL BE LESS THAN 10 KNOTS AND WITH PW ON
THE RISE (GPS IPWV INDICATE 1.5-2.0" AMOUNTS) WILL GET SOME
ISOLATED BRIEF HEAVY DOWNPOURS (PROBABLY IN THE ASSOCIATION WITH
THE LAKE BREEZES) IN THE EAST AND NORTHEAST ZONES. SEABREEZE MAY
GET A LITTLE MORE ACTIVE THIS AFTERNOON WITH PEAK HEATING. THE
UPPER RIDGE OVER THE AREA WILL SLOWLY WEAKEN TUESDAY AND SETTLE
SOUTH. HIGH PRESSURE TO THE NORTH WILL BRING A BACKDOOR FRONT TO
THE SABINE VALLEY AND THEN INTO THE AREA LATE TUESDAY. THIS SHOULD
LEAD TO MORE CLOUDS AND SLIGHTLY BETTER RAIN CHANCES. BY THURSDAY
THE RAIN CHANCES START GOING UP AREAWIDE WITH FRIDAY AND PERHAPS
SATURDAY BEING ACTIVE DAYS. WILL ALSO HAVE TO WATCH THE CONVECTION
IN THE CARIBBEAN...GFS AND ECMWF TRY TO BRING IT NORTHWEST AND
THEN NORTH WITH THE GFS THE MOST AGGRESSIVE. IT SPINS IT UP OVER
THE SOUTHCENTRAL GULF. PROBABLY OVERDOING BUT WILL NEED TO KEEP AN
EYE ON IT FOR CONSISTENCY. ECMWF NOT AS PESSIMISTIC WITH AN UPPER LOW
CUTTING OFF OVER TEXAS FRIDAY...IT IS NOW GOT STRONGER RIDGING
OVER WEST TEXAS AND UP THE MISSISSIPPI VALLEY WITH THE LOW LIFTING
NORTH INTO KS...THIS MAY BE AN EARLY (AND GOOD?) INDICATOR THAT RAIN
CHANCES GO DOWN ON SUNDAY.

[Aric Dunn]

intresting NAM .. yes yes . the nam i dont want to hear it... i use it for different reason I don't ever base a forecast off of.. but rather compare with other models..

its now develops nw carrib and off florida.. now.. interesting though . ukmet nogaps and gfs form something off of Florida! now the nam has 50kt upper winds at the 72hr .. but the gfs has a little .. one thing for models are trying to focus on something i dont see.. it would have to be a T'storm complex or something in that area in a couple of that moves off the se coast.. or maybe the tail of that front that is presently there..

the nogaps looks like it brings it from the carrib then possibly forms something on florida..

pretty much all the models are not sure whats happening... need a couple more days and something to start taking shape.

[Pearl River]

From this mornings New Orleans AFD:

.MARINE...
VERY LIGHT PRESSURE GRADIENT THROUGH WEDNESDAY...BECOMING MORE
EASTERLY AND MODERATE OVER THE CENTRAL GULF LATTER HALF OF WEEK. GFS
CONTINUES TO INDICATE SOME SORT OF SURFACE LOW PRESSURE AREA
DEVELOPING OVER THE WEEKEND NEAR YUCATAN THAT SWINGS INTO THE
WEST-CENTRAL GULF BEFORE BECOMING ABSORBED BY UPPER LEVEL TROUGH.
THIS SHOULD NOT BE A CONCERN FOR TROPICAL DEVELOPMENT AS THIS IS AN
INHERENT BIAS OF THE GFS THIS TIME OF YEAR. TIGHTENING OF THE TRADE
GRADIENT DOES APPEAR TO BE REAL HOWEVER AND SEAS APT TO BUILD IN
RESPONSE LATER IN THE FORECAST PERIOD...PARTICULARLY IN THE OUTER
WATERS.

[Aric Dunn]

actually even more interesting is the GFDL for the east pac invest... pay attention to the nw carrib and easter gulf come the 3 to 5 day range.. i see a low over there ... now given that gfdl is focusing on the east pac.. it still is something worth noting ... i have noticed throughout the previous hurricane seasons that when the gfdl is running on a particular system and there are more than that system near by that the gfdl will pick up on the other one as well but it normally under-estiamtes the other one so when i noticed the gulf i though it would be doing the same .. either way we have to wait and see.

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