000 AXNT20 KNHC 101803 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SAT MAR 10 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 1730 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 2N25W EQ42W AND INTO NE BRAZIL NEAR 1S51W. ISOLATED CLUSTERS OF MODERATE CONVECTION ARE WITHIN 90 NM N AND 150 NM S OF THE AXIS E OF 21W. SCATTERED MODERATE IS WITHIN 210 NM N AND 90 NM S OF AXIS BETWEEN 30W-51W. ...DISCUSSION... GULF OF MEXICO... WEAK SFC HIGH PRES RIDGING CONTINUES TO DOMINATE MUCH OF THE GULF...EXTENDING SW FROM THE 1035 MB CENTER PUSHING AWAY FROM THE MID ATLANTIC COAST. A WEAK TROUGH IS EMBEDDED IN THE RIDGE IN THE MIDDLE GULF WATERS S OF MISSISSIPPI...ALONG 29N88W 25N89W. SCATTERED LOW TO MID CLOUDS WITH POSSIBLE EMBEDDED LIGHT RAIN SHOWERS ARE WITHIN 120 NM E OF THE TROUGH AXIS. SIMILAR CLOUDS ARE IN THE SW GULF/BAY OF CAMPECHE S OF 25N. IN THE UPPER LEVELS...STRONG ZONAL FLOW DOMINATES MUCH OF THE BASIN BETWEEN RIDGING EXTENDING N FROM NICARAGUA AND A SHORTWAVE TROUGH PUSHING THROUGH THE ERN U.S. THE EXCEPTION IS NW FLOW OFF N TEXAS AND LOUISIANA WHICH IS ADVECTING EXTREMELY DRY UPPER AIR INTO THE ADJACENT GULF WATERS N OF 27N. THIS IS HELPING SUPPORT THE CLEAR SKIES/GOOD WEATHER BEING OBSERVED IN THE NW GULF. A BAND OF UPPER MOISTURE FROM THE EPAC CONTINUES TO SPREAD E THROUGH THE SRN GULF S OF 25N. OVER THE NEXT COUPLE OF DAYS...THE WEAK TROUGH WILL GRADUALLY DISSIPATE AS STRONG HIGH PRES BUILDS N OF THE REGION. THE PRES GRADIENT ON THE S SIDE OF THE HIGH WILL INCREASE THE SFC EASTERLIES SLIGHTLY ON SUN AND INTO EARLY NEXT WEEK. CARIBBEAN... QUIET WEATHER PERSISTS ACROSS MUCH OF THE BASIN THIS AFTERNOON WITH PLENTY OF DRY STABLE AIR ALOFT AND MODERATE TRADEWINDS IN PLACE. UPPER RIDGING GENERALLY DOMINATES THE REGION AS THE SHORTWAVE TROUGH HAS NOW PULLED E INTO THE CENTRAL ATLC. ABUNDANT FAIR WEATHER AND TYPICAL ISOLATED TRADE WIND SHOWERS ARE MOVING WWD ACROSS THE REGION. A MORE CONCENTRATED REGION OF LOW LEVEL MOISTURE IS NOTED ALONG COASTAL COSTA RICA AND PANAMA...ASSOCIATED WITH ONSHORE/UPSLOPE FLOW. TRANQUIL WEATHER IS EXPECTED TO CONTINUE THROUGH THE WEEKEND WITH CONDITIONS DOMINATED BY MODERATE TO FRESH TRADE WINDS. WESTERN ATLANTIC... A LARGE AREA OF MULTILAYER CLOUDINESS AND SCATTERED SHOWERS/TSTMS CONTINUE TO AFFECT THE REGION. THE STRONGEST CLUSTER OF MODERATE CONVECTION IS FROM 26N-29N BETWEEN 66W-71W. CLEAR UPPER DIFFLUENT FLOW IS HELPING SUPPORT THIS CONVECTION. THE SFC PATTERN CONTRIBUTING TO THIS UNSETTLED WEATHER REMAINS SOMEWHAT COMPLEX. A 1012 MB SFC LOW IS NEAR 27N72W THAT HAS A TROUGH EXTENDING S TO THE SE BAHAMAS NEAR 21N74W. A STATIONARY FRONT EXTENDS ENE FROM THE SURFACE LOW TO NEAR 31N49W. THIS AFTERNOONS SATELLITE IMAGERY SUGGESTS THERE MAY BE MORE THAN ONE WAVE OF LOW PRESSURE IN THIS AREA E OF THE BAHAMAS...SO WILL HAVE TO REEVALUATE FOR THE 1800 UTC MAP. THE MAIN LOW IS EXPECTED TO MOVE NE THROUGH TONIGHT WHILE INTERACTING WITH STRONG HIGH PRESSURE TO ITS NE. THIS WILL GENERATE GALE CONDITIONS ESPECIALLY N AND E OF THE LOW...IN ADDITION TO A PERSISTENT MODERATE ELY SWELL EVENT FOR THE SE U.S. COAST THROUGH EARLY NEXT WEEK. EASTERN ATLANTIC... STRONG HIGH PRESSURE RIDGING CONTINUES TO DOMINATE THE SFC PATTERN ACROSS THE ATLC E OF 45W. THIS HIGH IS PRODUCING MODERATE TO STRONG TRADE WINDS AND FAIR ACROSS A GOOD PORTION OF THE AREA. IN THE MID AND UPPER LEVELS...STRONG RIDGING ALSO DOMINATES WITH A HIGH CENTER SEEN SPINNING IN WV IMAGERY NEAR 18N31W. ABUNDANT DRY SUBSIDENT FLOW ALOFT IS WIDESPREAD AIDING IN THE FAIR WEATHER ACROSS THIS REGION. OVER THE NEXT FEW DAYS...TRADES WILL RELAX SLIGHTLY THROUGH EARLY TOMORROW AS HIGH PRES MOVES NE. HOWEVER THEY ARE SET TO PICK UP AGAIN FROM W TO E LATER SUN AND INTO NEXT WEEK AS STRONG HIGH PRES REBUILDS E ACROSS THE ATLC OCEAN. $$ WILLIS