000 AXNT20 KNHC 162354 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI MAR 16 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 3N20W CROSSING THE EQUATOR AT 38W AND INTO NE BRAZIL NEAR 3S46W. THE ITCZ IS PRETTY ACTIVE THIS EVENING WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ALONG THE AXIS AND WITHIN 50 NM N OF THE AXIS FROM 14W-22W...AND FROM 32W-38W. SIMILAR CONVECTION IS OVER NE BRAZIL. CLUSTERS OF STRONG CONVECTION ARE SEEN OVER SW AFRICA... PARTICULARLY OVER LIBERIA AND FROM 1N-4N BETWEEN THE PRIME MERIDIAN AND 8W. ...DISCUSSION... GULF OF MEXICO... A SHARP UPPER LEVEL TROUGH EXTENDS FROM THE GREAT LAKES REGION TO LOUISIANA...CLIPPING THE N GULF WATERS. AS OF 21Z...THE ATTENDANT COLD FRONT STRETCHES FROM THE FLORIDA PANHANDLE TO THE TEXAS COAST NEAR 28N96W. MOST OF THE CONVECTIVE ACTIVITY IS ASSOCIATED WITH A PRE-FRONTAL TROUGH THAT CROSSES NORTH-CENTRAL FLORIDA AND CONTINUES OVER THE SE GULF ALONG 24N85W TO THE YUCATAN PENINSULA. MOSAIC DOPPLER RADAR FROM THE SE US SHOWS A NARROW BAND OF SHOWERS WITH EMBEDDED TSTMS MOVING ACROSS LAKE OKEECHOBEE WHILE OTHER CELLS ARE DEVELOPING OVER SOUTH FLORIDA. A WELL DEFINED SHORT-WAVE TROUGH MOVING AROUND THE BASE OF THE LONG WAVE TROUGH MENTIONED ABOVE IS ENHANCING THIS CONVECTION THAT IS ALSO AFFECTING THE SE GULF AND PARTS OF CUBA. THE COLD FRONT IN THE NRN GULF IS ANTICIPATED TO PUSH SE AND MERGE WITH THE PRE-FRONTAL TROUGH ACROSS FLORIDA TONIGHT. THE FRONT IS FORECAST TO CLEAR SOUTH FLORIDA JUST AFTER MIDNIGHT REACHING THE NW BAHAMAS AND W CUBA AFTERWARDS. INCREASE IN WINDS AND SEAS IS EXPECTED IN THE WAY OF THE FRONT TONIGHT THROUGH SAT NIGHT... THEN SUBSIDING ACROSS MUCH OF THE GULF EXCEPT THE SE PORTION SAT NIGHT AND SUNDAY. BEHIND THE FRONT...HIGH PRES WILL GRIP THE GULF AND THE STATE OF FLORIDA WITH A COLD AND DRY AIRMASS. CARIBBEAN... AS MENTIONED IN THE GULF SECTION...A SHORT-WAVE TROUGH WITH THE AXIS ACROSS W-CENTRAL CUBA AND THE NW CARIBBEAN IS SUPPORTING THE DEVELOPMENT OF SCATTERED SHOWERS AND TSTMS OVER THE YUCATAN PENINSULA...PARTS OF CUBA/JAMAICA AND COASTAL WATERS...AND THE NW CARIBBEAN INCLUDING ALSO NE HONDURAS. THIS TROUGH COVERS MUCH OF THE W AND CENTRAL CARIBBEAN WHILE THE WRN PERIPHERY OF A BROAD RIDGE DOMINATES THE REMAINDER OF THE BASIN. STRONG SWLY WINDS ASSOCIATED WITH THIS RIDGE ARE ADVECTING SOME UPPER LEVEL MOISTURE/HIGH CLOUDS FROM N SOUTH AMERICA TO THE E CARIBBEAN INTO THE TROPICAL NORTH ATLC. TYPICAL PATCHES OF LOW LEVEL MOISTURE ARE FOUND ACROSS THE AREA...ESPECIALLY OVER HISPANIOLA. TRADE WINDS HAVE SLACKEN IN THE WRN CARIB AS LOW PRES IS LOCATED N OF THE AREA BUT REMAIN MODERATE TO FRESH ACROSS THE CENTRAL AND ERN PARTS. LOOKING AHEAD...A COLD FRONT IS EXPECTED TO PUSH INTO THE REGION TONIGHT INCREASING THE CHANCE OF SHOWERS AS IT PROGRESSES EWD AND WEAKENS. DRIER AND SLIGHTLY COOLER WEATHER WILL FOLLOW ADVECTED BY MODERATE TO STRONG NLY WINDS. WESTERN AND CENTRAL ATLANTIC... A BAND OF SHOWERS AND TSTMS IS MOVING ACROSS THE NW CORNER OF THE FORECAST AREA AND IS RELATED TO A PRE-FRONTAL TROUGH MOVING ACROSS SOUTH-CENTRAL FLORIDA AND THE SE GULF. A COLD FRONT ENTERS THE REGION NEAR 32N45W AND EXTENDS TO 25N49W THEN CONTINUES AS A SFC TROUGH TO JUST N OF PUERTO RICO. THE SAN JUAN DOPPLER RADAR SHOWS ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH THIS FEATURE. A 1025 MB HIGH IS LOCATED NE OF BERMUDA. THIS SYSTEM IS MOVING EWD AHEAD OF A COLD FRONT/PRE-FRONTAL TROUGH EMERGING OFF THE SE COAST/FLORIDA PENINSULA. ALOFT... MAINLY ZONAL FLOW DOMINATES THE AREA. EASTERN ATLANTIC... THE WEATHER PATTERN REMAINS QUIET WITH STRONG RIDGING BOTH AT THE SFC AND ALOFT DOMINATING MOST OF THE REGION. THERE ARE SOME HIGH CLOUDS...DEBRIS MOISTURE FROM THE COLD FRONT IN THE CENTRAL ATLC...STREAMING ACROSS THE RIDGE AXIS BUT MUCH OF THE AREA IS VOID OF PRECIP. AN UPPER LOW IS SPINNING JUST WEST OF THE MADEIRA ISLANDS WITH AN UPPER TROUGH EXTENDING SOUTH TO NEAR THE CAPE VERDE ISLANDS. THIS LOW WILL MOVE MAINLY S ENTERING THE FORECAST AREA ON MONDAY. A JETSTREAM BOUNDS THE S PERIPHERY OF THE TROUGH ADVECTING UPPER LEVEL MOISTURE ACROSS AFRICA. DRY AIR...RESULTING IS MODERATE TO STRONG SUBSIDENCE IS OBSERVED ON WV IMAGERY E OF 25N FROM 14N-25N. THE SFC RIDGE IS PRODUCING A LARGE AREA OF MODERATE TO STRONG WINDS ACROSS THE REGION. THIS RIDGE IS EXPECTED TO SHIFT SWD TIGHTENING THE PRES GRAD WHICH WILL INCREASE THE WINDS FURTHER ESPECIALLY N OF 22N LATE THIS WEEKEND. $$ GR