000 AXNT20 KNHC 091129 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI MAR 09 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1100 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 4N20W 3N32W 1N43W TO 1S51W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM S OF THE AXIS E OF 13W AND FROM 1S-1N BETWEEN 39W-43W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 30 NM EITHER SIDE OF THE AXIS BETWEEN 20W-43W. ...DISCUSSION... GULF OF MEXICO... IT'S ANOTHER RELATIVELY QUIET MORNING IN THE GULF AS WEAK VERTICALLY STACKED RIDGING REMAINS PARKED ACROSS THE REGION. UPPER LEVEL SWLY FLOW ON THE WRN PERIPHERY OF THE RIDGE IS ADVECTING HIGH LEVEL MOISTURE FROM THE EPAC ACROSS CENTRAL MEXICO AND INTO THE GULF MAINLY BETWEEN 24N-28N. EVEN THOUGH THE ATMOSPHERE IS A LITTLE MORE MOIST THAN THE PAST FEW DAYS...CONDITIONS REMAIN FAIR ACROSS THE ENTIRE AREA. MODERATE DRY AIR EXISTS BOTH S AND N OF THE UPPER MOISTURE PLUME. THE WEAK PATTERN AT THE SFC IS KEEPING WINDS AND SEAS FAIRLY LIGHT AND THEY ARE EXPECTED TO REMAIN THAT WAY THROUGH SAT AS THE SFC PRES GRADIENT CHANGES LITTLE. MAINLY FAIR WEATHER IS ALSO EXPECTED TO CONTINUE UNDER WEAK HIGH PRES. THE ONLY AREA OF POSSIBLE DEVELOPING WEATHER IS IN THE CENTRAL GULF AS GFS HAS BEEN HINTING AT DEVELOPING A VERY WEAK LOW-LEVEL TROUGH LATER TODAY THAT MAY PRODUCE SOME ORGANIZED CLOUDS/SHOWERS. CARIBBEAN... MUCH OF THE CARIB IS QUIET THIS MORNING WITH PLENTY OF DRY STABLE AIR ALOFT IN PLACE. THIS DRY AIR IS BEING ENHANCED BY A SHORTWAVE TROUGH THAT EXTENDS SWD FROM THE ATLC ACROSS PUERTO RICO TO 14N68W. THERE IS A FAIR AMOUNT OF MID TO UPPER LEVEL MOISTURE AND EVEN SOME SMALL POCKETS OF MODERATE CONVECTION OVER COLOMBIA PRODUCED BY SFC LIFT ALONG THE ITCZ AND UPPER DIFFLUENCE BETWEEN THE SHORTWAVE AND A STRONG UPPER RIDGE CENTERED OVER NE S AMERICA. MOST OF THIS MOISTURE IS CONTAINED S OF 13N. IN THE LOWER LEVELS...NIGHT CHANNEL VIS SHOWS VERY THIN PATCHES OF CLOUDS DRIVEN W BY MODERATE TO FRESH TRADES. THERE IS A LITTLE MORE ORGANIZATION TO THE CLOUDS OVER THE YUCATAN PENINSULA AND THE CHANNEL ASSOCIATED WITH THE REMNANTS OF A WEAK SFC TROUGH. MUCH MORE ACTIVE WEATHER LIES TO THE N OF THE REGION E OF THE BAHAMAS AND IS DISCUSSED IN THE WESTERN ATLC SECTION BELOW. TRANQUIL WEATHER IS EXPECTED TO CONTINUE INTO THE WEEKEND. WESTERN ATLANTIC... UNLIKE THE GULF AND CARIB THERE IS MORE SIGNIFICANT WEATHER TO TALK ABOUT IN THIS REGION. THE MAIN PLAYERS ARE AN UPPER LEVEL SHORTWAVE TROUGH ROTATING THROUGH THE BASE OF A LARGE POLAR VORTEX AND A SFC TROUGH ANALYZED FROM ERN CUBA TO 30N65W. A WEAK SFC LOW HAS FORMED ALONG THIS TROUGH NEAR 25N73W. THIS FEATURE IS WELL DEPICTED IN AN EARLIER QSCAT PASS AND SFC OBS WHICH DISPLAY CYCLONIC TURNING ESPECIALLY ACROSS THE CENTRAL AND EASTERN BAHAMAS. INFRARED SATELLITE IMAGES DEPICT SOME COLD CLOUD TOPS FROM 22N-32N BETWEEN 56W-70W. SCATTERED SHOWERS APPEAR VERY LIKELY IN THIS OUTLINED AREA...WHICH IS E OF THE SFC TROUGH DUE TO THE STRONGLY SHEARED ENVIRONMENT. A COLD FRONT IS LINED UP BEHIND THE TROUGH ENTERING THE AREA NEAR 32N61W TO 30N75W THEN STATIONARY TOWARD THE SE GEORGIA COAST. GFS SHOWS THIS FRONT MERGING WITH THE TROUGH/LOW LATER TODAY LIKELY CONTINUING TO PRODUCE UNSETTLED WEATHER FOR PARTS OF THE REGION. BEHIND THE FRONT...STRONG HIGH PRES IS SURGING SE. THIS IS SETTING UP A TIGHT PRES GRAD CAUSING STRONG NELY WINDS THAT WILL SPREAD SE INTO THE AREA TODAY. EASTERN ATLANTIC... A STRONG 1036 MB HIGH PRES SYSTEM LOCATED BETWEEN PORTUGAL AND THE AZORES IS DOMINATING THE SFC PATTERN ACROSS THE ATLC E OF 45W. THIS HIGH IS PRODUCING MODERATE TO STRONG TRADE WINDS ACROSS A GOOD PORTION OF THE DISCUSSION AREA PARTICULARLY E OF 30W WHERE THE TIGHTEST PRES GRAD EXISTS. THE UPPER LEVEL TROUGH THAT HAS BEEN DRIFTING N IN THE AREA HAS NOW JUST ABOUT DISSIPATED. ONLY PATCHES OF MID AND HIGH LEVEL CLOUDS ARE LEFT N OF 22N BETWEEN 20W-30W. ELSEWHERE DRY AIR ALOFT DOMINATES PROVIDING STABLE CONDITIONS. OVER THE NEXT COUPLE OF DAYS...THE STRONG SFC HIGH IS FORECAST TO RETREAT NE ALLOWING THE TRADES TO RELAX SLIGHTLY THIS WEEKEND IN THE E ATLC. HOWEVER THEY ARE SET TO PICK UP AGAIN ON SUN AND INTO NEXT WEEK AS STRONG HIGH PRES BUILDS E ACROSS THE ATLC. $$ CANGIALOSI