000 AXNT20 KNHC 141719 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT FEB 14 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 1515 UTC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 05N08E TO 08N01W TO 03N20W TO 00N40W AND FOLLOWS THE EQUATOR WESTWARD INTO NE BRAZIL ENDING NEAR 50W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION CAN BE FOUND ALONG THE AFRICAN COAST WITHIN 180 NM SW OF THE ITCZ E OF 03E. SCATTERED MODERATE CONVECTION LIES WITHIN 90 NM OF THE ITCZ BETWEEN 10W AND 21W AND WITHIN 120 NM OF THE ITCZ BETWEEN 25W AND 29W. ...DISCUSSION... GULF OF MEXICO... MODERATE TO STRONG THUNDERSTORMS CAN BE FOUND MAINLY WITHIN 45 NM OF THE NORTHERN GULF COAST THIS AFTERNOON. AT THE SURFACE...A COLD FRONT IS SLOWLY MAKING ITS WAY TO THE TX COAST AND EASTWARD ACROSS THE GULF COAST STATES. THE FRONT IS NOT EXPECTED TO PENETRATE MUCH FARTHER S INTO THE GULF UNTIL THE STEERING FLOW BECOMES MORE AMPLIFIED SUN AFTERNOON/EVENING. UNTIL THEN...SHOWERS AND THUNDERSTORMS SHOULD PERSIST OVER THE NORTHERN GULF. A SURFACE WAVE WILL DEVELOP OVER THE NORTHERN GULF OF MEXICO AND MOVE EASTWARD INTO THE ATLC SUN/MON...SENDING THE ASSOCIATED COLD FRONT SOUTHWARD THROUGH THE GULF. OVER THE SOUTHERN HALF OF THE GULF...SUBSIDENCE PERSISTS WITH VERY DRY MID TO UPPER LEVELS. STABLE CONDITIONS HELPED GENERATE MOSTLY PATCHY FOG OVERNIGHT FRI NIGHT IN THE SOUTHERN GULF THAT SHOULD BE BURNING OFF TODAY AS SOUTHEASTERLY FLOW PICKS UP BETWEEN THE HIGH PRESSURE MOVING EASTWARD AWAY FROM FL AND THE COLD FRONT OVER THE NORTHERN GULF. CARIBBEAN SEA... THE CARIBBEAN IS VOID OF DEEP CONVECTION WITH STRONG SUBSIDENCE AND DRY AIR IN THE MID AND UPPER LEVELS COUPLED WITH CONFLUENT FLOW ALOFT BETWEEN THE RIDGING OFF THE WEST COAST OF CENTRAL AMERICAN AND THE SOUTHERN END OF THE TROUGH OVER THE WESTERN ATLC/EASTERN CARIBBEAN. EASTERLY TRADE WINDS ARE GENERALLY IN THE 20 TO 25 KT RANGE S OF 18N E OF 80W. HOWEVER...THE 1042 QUIKSCAT PASS SHOWS WINDS TO 30 KT OFF THE COAST OF COLOMBIA. ELSEWHERE IN THE CARIBBEAN...WINDS ARE LESS THAN 20 KT. ISOLATED EASTERLY MOVING HIGH CLOUDS CAN BE FOUND OVER THE SOUTHERN CARIBBEAN. WEAK TO MODERATE TRADE WINDS SHOULD CONTINUE OVER MUCH OF THE CARIBBEAN THROUGH THE SUN...WITH ISOLATED TRADE SHOWERS MOVING WESTWARD ACROSS THE REGION. THE CHANCE OF CONVECTION WILL INCREASE OVER THE EASTERN CARIBBEAN SUN AS THE INVERTED TROUGH CURRENTLY OVER NORTHERN BRAZIL MAKES ITS WAY WESTWARD...TRANSPORTING LOW TO MID LEVEL MOISTURE ALONG WITH IT. ATLANTIC OCEAN... AN INVERTED TROUGH ALONG 49W S OF 08N INTO NORTHERN BRAZIL HAS SCATTERED MODERATE CONVECTION ACCOMPANYING IT WITHIN 150 NM FROM 00N TO 04N. THIS SURFACE TROUGH CURRENTLY LIES WITHIN THE REAR RIGHT QUADRANT OF THE UPPER JET STRETCHED ACROSS THE TROPICAL ATLC FROM AFRICA. THIS JET IS EXPECTED TO LIFT NORTHWARD AS THE UPPER RIDGE TO ITS SOUTH EXPANDS...MOVING THE REGION OF BEST UPPER LEVEL DIFFLUENCE NORTHWARD AS THE SYSTEM APPROACHES THE LESSER ANTILLES. CURRENTLY...UPPER LEVEL MOISTURE IS BEING ADVECTED NORTHEASTWARD ACROSS THE ATLC S OF 22N BY THIS JET...GENERATING SOME HIGH CLOUDINESS. THE ASCAT PASSES FROM 0900 AND 0720 UTC SHOW TRADE WINDS IN THE 20 TO 25 KT RANGE GENERALLY WITHIN 360 NM OF A LINE FROM 22N16W TO 09N54W. FAIR WEATHER AND SUBSIDENCE COVERS MUCH OF THE NORTHEAST FORECAST WATERS. FARTHER SOUTH...UPPER LEVEL DIFFLUENCE BETWEEN THE RIDGE AXIS OFF THE SOUTH COAST OF WEST AFRICA AND AN UPPER LOW NEAR 10S15W IS ENHANCING CONVECTION ALONG THE ITCZ. IN THE WESTERN ATLC S OF 20N...WINDS HAVE ALREADY BEGUN TO DIMINISH AS THE DEEP LAYER TROUGH OVER THE WESTERN ATLC APPROACHES. THE SUBTROPICAL SURFACE HIGH NEAR 28N34W SHOULD REMAIN STATIONARY OVER THE NEXT FEW DAYS AS A SERIES OF COLD FRONTS PASS THROUGH THE WESTERN ATLC AND LIFT NORTH OF THIS HIGH. THE SURFACE COLD FRONT ASSOCIATED WITH THE DEEP LAYER TROUGH LIES OVER FORECAST WATERS FROM 31N50W TO 25N60W TO 24N74W AND A SECONDARY SURGE OF COLD AND DRY AIR IS FAST ON ITS HEELS JUST NORTH OF 32N. SCATTERED SHOWERS CAN GENERALLY BE FOUND WITHIN 60 NM OF THE LEAD COLD FRONT OVER FORECAST WATERS E OF 65W. THE QUIKSCAT PASS FROM 0906 UTC SHOWS SOUTHWEST WINDS TO 30 KT WITHIN 120 NM OF THIS FRONT E OF 55W. ON SUN...A NEW SURFACE LOW IS EXPECTED TO PASS OFF THE CAROLINA COAST AND BRING ANOTHER COLD FRONT INTO NW FORECAST WATERS. $$ SCHAUER CLARK