000 AXNT20 KNHC 050537 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED MAR 05 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 2N30W CROSSING THE EQUATOR NEAR 36W TO 3S42W. SCATTERED MODERATE TO STRONG CONVECTION FROM 2N-6N BETWEEN 8W-13W AND IS WITHIN 150 NM EITHER SIDE OF AXIS FROM 19W-23W AND FROM 1N-4N BETWEEN 31W-45W. ...DISCUSSION... GULF OF MEXICO STRONG COLD FRONT ASSOCIATED WITH A DEEP LAYER LOW PRES SYSTEM OVER THE OHIO VALLEY EXTENDS FROM THE FLORIDA BIG BEND TO THE YUCATAN PENINSULA ALONG. SATELLITE INDICATES LINES OF SCATTERED SHOWERS AND TSTMS NEAR THE YUCATAN CHANNEL AND THE FLORIDA KEYS ARE DISSIPATING. OTHERWISE SHOWER ACTIVITY IS ALSO DISSIPATING OVER CENTRAL FLORIDA. W OF THE FRONT WINDS HAVE DECREASED TO BELOW GALE FORCE AS WEAK HIGH PRES HAS NOW ENTERED THE WESTERN GULF RELAXING THE PRES GRADIENT. A 85-100 KT JET EXTENDS FROM BROWNSVILLE TEXAS ACROSS THE N CENTRAL GULF...NEAR 28N90W TO THE FLORIDA BIG BEND. BROKEN CIRRUS CLOUDS ARE WITHIN 200 NM S OF THE JET W OF 90W. CARIBBEAN SEA... WEAK UPPER SHORTWAVE EXTENDS FROM THE VIRGIN ISLANDS TOWARD THE N SHORE OF COLOMBIA WHILE A MID TO UPPER RIDGE CONTROLS THE PATTERN ALOFT IN THE WESTERN CARIBBEAN. WIDESPREAD SUBSIDENCE IS ASSOCIATED WITH THESE UPPER SYSTEMS KEEPING THE TYPICAL SHALLOW LOW-LEVEL MOISTURE PATCHES. SATELLITE IMAGERY INDICATES THAT THE THICKEST CLOUD PATCHES ARE NEAR THE LEEWARD AND WINDWARD ISLANDS AND MUCH OF THE CENTRAL PORTION N OF 16N BETWEEN 65W-78W. AS USUAL...ISOLATED TO SCATTERED QUICK MOVING SHOWERS AND ARE LIKELY EMBEDDED IN THESE PATCHES. TRADE WINDS REMAIN ON THE STRONG SIDE ESPECIALLY IN THE TYPICAL ENHANCED ZONE NEAR THE COLOMBIAN COAST WHERE SUSTAINED WINDS ARE TO 30 KT. ATLANTIC OCEAN.... MID/UPPER LEVEL RIDGE EXTENDS FROM CENTRAL CUBA ACROSS THE BAHAMAS TO 32N72W. LARGE SFC RIDGE COVERS MUCH OF THE ATLC W OF AROUND 42W. FAIRLY QUIET CONDITIONS ARE BENEATH THIS RIDGE EXCEPT FOR AN AREA OF WEAKENING SCATTERED SHOWERS FROM 24N-27N BETWEEN 63W-68W....LIKELY DUE TO A SMALL WEAK MID-LEVEL DISTURBANCE. AN UPPER TROUGH WITH AXIS FROM 32N32W TO 24N41W. SURFACE COLD FRONT CLIPS THE N PORTION OF THE REGION EXTENDING FROM 32N35W TO 26N41W. LITTLE SIGNIFICANT WEATHER IS ASSOCIATED WITH THE FRONT EXCEPT FOR BROKEN/OVERCAST LOW CLOUDS NW OF THE FRONT TO 60W. IN THE TROPICS...AN E-W STRETCHED RIDGE WITH ANTICYCLONIC CIRCULATION CENTERED NEAR 4N23W. DIFFLUENCE ALOFT ASSOCIATED WITH THIS RIDGE IS AIDING CONVECTION IN THE ITCZ. $$ DGS