000 AXNT20 KNHC 071805 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED MAR 07 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N10W 5N20W 1N35W EQ45W EQ50W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM S OF THE AXIS E OF 19W AND FROM 4S-4N W OF 28W. ...DISCUSSION... GULF OF MEXICO... SFC RIDGING ALONG THE NRN GULF COAST CONTINUES TO DOMINATE THE GOMEX THIS AFTERNOON. THIS IS PRODUCING FAIRLY LIGHT WINDS ACROSS THE AREA WITH SEAS CONTINUING TO SUBSIDE MOSTLY BELOW 4 FT EXCEPT THE AREA S OF 25N E OF 94W WHERE SOME LINGERING ENE SWELL EXISTS. FAIRLY EXTENSIVE LOW LEVEL CLOUD DECK IS SEEN OFFSHORE TEXAS AND LOUISIANA...N OF 26N BETWEEN 88W-96W. IN THE MID AND UPPER LEVELS...THE FLOW IS MAINLY FROM THE WNW AROUND GENTLE RIDGING BUILDING INTO THE GULF FROM MEXICO AND BEHIND THE POLAR VORTEX EXTENDING S FROM ERN CANADA. THIS IS ADVECTING A FEW PATCHES OF CIRRUS THROUGH THE GULF BUT OVERALL FAIRLY DRY UPPER AIR DOMINATES. OVER THE NEXT COUPLE OF DAYS...WEAK RIDGING WILL PERSIST ALONG THE NRN GULF COAST KEEPING WINDS LIGHT TO MODERATE. THE MID AND UPPER PATTERN WILL LIKELY REMAIN NEARLY ZONAL BUT MAY INCREASE IN MAGNITUDE AS SMALL IMPULSES/VORT MAXES MOVE ACROSS THE SRN U.S. CARIBBEAN... A PIECE OF THE OLD FRONTAL BOUNDARY SEEMS TO HAVE REESTABLISHED ITSELF IN THE GULF OF HONDURAS. SATELLITE IMAGERY SUGGESTS A WEAK LOW MAY HAVE RECENTLY FORMED JUST N OF THE ISLAS DE LA BAHIA...AND WILL REEVALUATE FOR THE 1800 MAP. BASED ON THE BROAD ELONGATED TURNING SEEN IN THIS MORNINGS HIRES QUIKSCAT DATA...HAVE OPTED WITH A TROUGH WHICH WAS PLACED ALONG 19N84W 15N86W AS OF 1500 UTC. SUSPECT THERE ARE SCATTERED SHOWERS EMBEDDED IN THE ASSOCIATED BROKEN LOW TO MID CLOUD DECK SEEN ALONG COASTAL HONDURAS AND BELIZE...AND CARIB WATERS FROM 15N-21N BETWEEN 82W-89W. GFS SUGGESTS THIS AREA WILL DRIFT SLOWLY W OVER THE NEXT COUPLE OF DAYS...WITH SHOWERS LINGERING BETWEEN HONDURAS...BELIZE...AND THE WRN YUCATAN. OTHER LOW LEVEL CONFLUENT ZONES WITH POSSIBLE SHOWERS SEEN HUGGING THE COAST OF HISPANIOLA THROUGH ERN CUBA...ALSO SOME ENERGY LEFT OVER FROM THE FRONTAL TROUGH. A SIMILAR LOW LEVEL MOISTURE PATCH IS BEGINNING TO AFFECT SW PUERTO RICO. ELSEWHERE MODERATE TRADES AND FAIR WEATHER ARE DOMINATING. ALOFT...THE FLOW IS RATHER ZONAL WITH A LARGE AMOUNT OF DRY STABLE AIR ...ESPECIALLY E OF 78W...KEEPING MOST OF THE MOISTURE PATCHES SHALLOW. WESTERN ATLANTIC... DEEP LAYER TROUGHING COVERS THE MAJORITY OF THE ATLC W OF 50W EXTENDING SWD FROM A LARGE POLAR LOW. TWO COLD FRONTS ARE ASSOCIATED WITH THE TROUGH. ONE OF THESE HAS BEEN IN THE AREA FOR QUITE SOMETIME AND IS ANALYZED ALONG 32N48W 24N64W THEN STATIONARY ACROSS THE SE BAHAMAS. BROKEN LOW AND MID LEVEL CLOUDS AND EMBEDDED SHOWERS ARE WITHIN 120 NM ALONG AND AHEAD OF THE COLD FRONT AND WITHIN 150 NM NW OF THE STATIONARY PART OF THE BOUNDARY. A PREFRONTAL TROF LIES JUST E OF THE FRONT ALONG 25N55W 21N68W. THE SECONDARY AND WEAKER OF THE FRONTS EXTENDS WSW FROM 32N54W TO 27N75W THEN NW TO 29N79W. A THIN ROPE CLOUD HAS BEEN ASSOCIATED WITH THIS BOUNDARY BUT IS BECOMING RATHER RAGGED. MODELS SHOW THE LAYERED TROUGH HOLDING ON THROUGH MIDWEEK BEFORE PULLING NE TOWARD THE END OF THE WEEK. GFS IS HINTING AT DEVELOPING A SFC TROUGH OR WEAK LOW IN THE BAHAMAS LATE THU/FRI WHICH MAY PRODUCE SOME UNSETTLED WEATHER...ALONG WITH A PROLONGED ELY SWELL EVENT FOR THE SE U.S. COAST. EASTERN ATLANTIC... A 1035 MB HIGH PRES SYSTEM LOCATED A FEW HUNDRED NM S OF THE AZORES NEAR 34N24W IS DOMINATING THE SFC PATTERN ACROSS THE ATLC E OF 45W. THIS HIGH IS PRODUCING MODERATE TO STRONG TRADES ACROSS A GOOD PORTION OF THE DISCUSSION ZONE. THE MAIN FEATURE IN THIS AREA IS IN THE MID TO UPPER LEVELS WHERE A FAIRLY VIGOROUS LOW IS LOCATED NEAR 26N40W. DIFFLUENT ZONE TO THE E OF THE UPPER LOW AND ASSOCIATED TROUGHING IS GENERATING A FAIR AMOUNT OF MOISTURE FROM 10N-31N BETWEEN 25W-40W. MODELS SHOW THE UPPER LOW MOVING NWD AND OPENING INTO A TROUGH THROUGH TOMORROW. THIS WILL LIKELY REDUCE THE FETCH OF MOISTURE ACROSS THE REGION AS UPPER RIDGING GAINS CONTROL. $$ WILLIS