000 AXNT20 KNHC 102333 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE APR 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N10W 4N25W 2N30W CROSSING THE EQUATOR AT 40W INTO NE BRAZIL NEAR 2S48W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 80-100 NM N OF THE AXIS W OF 22W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE OVER SW AFRICA BETWEEN 5N-11N AND BETWEEN THE PRIME MERIDIAN AND 11W. SIMILAR CONVECTION IS OVER NE BRAZIL. ...DISCUSSION... THE GULF OF MEXICO... A FRONTAL SYSTEM CONTINUES TO SLOWLY DRIFT N IN THE NRN GULF. AS OF 21Z...THE FRONT WAS ANALYZED FROM CENTRAL FLORIDA JUST NORTH OF LAKE OCKEECHOBEE TO SE LOUISIANA. THE FRONT IS PRODUCING AN AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS OVER THE NE QUADRANT OF THE GULF AND ACROSS N/CENTRAL FLORIDA AND INTO THE WEST ATLC. THE STRONGER CELLS ARE EAST OF LAKE OCKEECHOBEE ENTERING THE WEST ATLC. A SEVERE THUNDERSTORM WARNING AND A TORNADO WARNING HAVE BEEN ISSUED FOR THIS AREA. SCATTERED THUNDERSTORMS HAVE BEGUN TO DEVELOP OVER THE STRAITS OF FLORIDA AND WEST OF THE EVERGLADES. THE FRONT IS FORECAST TO MOVE SLOWLY NORTH AND BE OUT OF THE REGION BY TOMORROW. A WEAK COLD FRONT WILL MOVE INTO THE NW GULF TOMORROW MORNING. THE MAJORITY OF THE MOISTURE WILL MOVE OVER SOUTH FLORIDA WITH LIGHT TO MODERATE SOUTHERLY RETURN FLOW AHEAD OF THE COLD FRONT. THE GFS MODEL CONTINUES TO DEVELOP A LOW OVER N/CENTRAL FLORIDA EARLY TOMORROW MORNING. THE LOW IS EXPECTED TO MOVE NE ACROSS FLORIDA INTO THE WEST ATLC KEEPING MOISTURE OVER THE FLORIDA PENINSULA. A SHORT WAVE TROUGH EXISTS OVER THE WESTERN GULF WITH THE DIFFLUENT PATTERN AHEAD OF THE TROUGH ENHANCING THE SHOWER AND THUNDERSTORM ACTIVITY IN THE NE GULF. THE WEATHER CONDITIONS ARE MORE TRANQUIL AND TROPICAL-LIKE S OF THE FRONT. A PLUME OF MID-HIGH LEVEL CLOUDS IS BEING TRANSPORTED BY EXTENSIVE MODERATE TO STRONG SWLY UPPER FLOW FROM THE EPAC ACROSS THE YUCATAN PENINSULA INTO THE SE GULF. THE CARIBBEAN SEA... A BROAD MID TO UPPER LEVEL RIDGE COVERS THE REGION ANCHORED BY AN UPPER HIGH CENTERED OVER THE S CENTRAL CARIB NEAR 11N74W. DIFFLUENCE ON THE W SIDE OF THIS UPPER ANTICYCLONE IS ENHANCING CLUSTERS OF MODERATE CONVECTION OVER PANAMA AND COSTA RICA. A NARROW BAND OF HIGH CLOUDS IS CROSSING CENTRAL AMERICA EXTENDING TO EASTERN CUBA AND THE SOUTHERN BAHAMAS. ELSEWHERE...DRY AIR AND MODEST SUBSIDENCE IS KEEPING CONDITIONS FAIRLY TRANQUIL OVER THE EAST CARIBBEAN. AT THE SFC...WEAK HIGH PRES N OF THE AREA IS PRODUCING MODERATE TO STRONG TRADES OVER THE SW CARIBBEAN. NO SIGNIFICANT CHANGES ARE EXPECTED OVER THE NEXT COUPLE OF DAYS AS MOST OF THE WX FEATURES REMAIN N OF THE REGION. THE ATLANTIC OCEAN... ZONAL FLOW DOMINATES THE WEST/CENTRAL ATLANTIC WITH A STREAK OF MULTILAYERED CLOUDS ROUGHLY N OF 24N. THE DIFFLUENCE AHEAD OF THE SHORTWAVE TROUGH IN THE GULF OF MEXICO IS ENHANCING CONVECTION IN THE WEST ATLC. A SURFACE LOW IS EXPECTED TO DEVELOP OVER N/CENTRAL FLORIDA EARLY TOMORROW MORNING AND MOVE ACROSS THE WEST ATLC NORTH OF THE REGION BY THURSDAY. A WEAK SURFACE HIGH IN THE CENTRAL ATLC NEAR 28N63W WILL DISSIPATE WITHIN 24 HOURS. A WEAKENING SURFACE TROUGH EXTENDS FROM 28N59W TO NEAR NORTHERN HISPANIOLA WHERE IT CONTINUES TO PRODUCE WEAK CONVECTION. THE SAN JUAN DOPPLER RADAR IS SHOWING NORMAL AFTERNOON SHOWERS OVER THE MOUNTAINS OF PUERTO RICO. A RIDGE/TROUGH PATTERN BREAKS UP THE ZONAL FLOW IN THE EASTERN ATLC. THE MOISTURE IS DEEPEST IN AN UPPER DIFFLUENT ZONE...N OF 29N BETWEEN 31W-43W...IN RESPONSE TO THE LARGE TROUGH THAT ENCOMPASSES MUCH OF THE E ATLC. THIS UPPER TROUGH AXIS IS VERY PRONOUNCED EXTENDING FROM AN UPPER LOW OFF THE IBERIAN PENINSULA ENTERING THE AREA NEAR 32N19W AND EXTENDING WELL SSW INTO THE DEEP TROPICS NEAR 5N42W. DRY AIR IS PRESENT ALONG THE TROUGH AXIS WITH A BROAD BAND OF UPPER LEVEL MOISTURE SE OF THE TROUGH EXTENDING FROM NE SOUTH AMERICA TO WESTERN AFRICA CROSSING SOUTH OF THE CAPE VERDE ISLANDS. $$ RJW/GR