000 AXNT20 KNHC 211740 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAR 21 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 1715 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N AT THE PRIME MERIDIAN 3N11W 1N21W EQ30W 1S40W TO NE BRAZIL NEAR 3S44W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 18W-24W AND 31W-36W. SIMILAR ACTIVITY IS WITHIN 150 NM S OF THE AXIS BETWEEN 24W-31W AND FROM 2N-6N BETWEEN 30W-43W. ...DISCUSSION... GULF OF MEXICO... FAIRLY QUIET WEATHER EXISTS IN THE GULF AS STRONG HIGH PRES...CENTERED IN THE NE U.S...COVERS THE REGION. THE MAIN WEATHER ELEMENT IS THE STIFF E TO SELY WINDS ON THE SW PERIPHERY OF THE SFC RIDGE. SFC OBS AND QSCAT DATA SHOW THE WINDS GENERALLY IN THE 15-25 KT RANGE. THESE WINDS WILL STAY ON THE STRONG SIDE...ALTHOUGH SLIGHT RELAXING IS ANTICIPATED THU AND FRI. ISOLATED PATCHES OF SHALLOW MOISTURE ARE BEING STEERED ACROSS THE GULF AROUND THE SFC RIDGE LIKELY PRODUCING SOME QUICK MOVING ISOLATED SHOWERS. IN THE UPPER LEVELS...NWLY FLOW TO THE W OF A WRN ATLC SHORTWAVE IS COMMON WITH ONLY PATCHY LAYERED CLOUDS AND ISOLATED SHOWERS N OF 25N BETWEEN 88W-94W. AN INCREASE IN MOISTURE IS LIKELY ACROSS THE EXTREME SE GULF AS THE UPPER SHORTWAVE DEEPENS SLIGHTLY. ELSEWHERE MAINLY FAIR WEATHER IS EXPECTED TO PERSIST OVER THE NEXT COUPLE OF DAYS AS THE REGION REMAINS ON THE SW PERIPHERY OF THE SFC HIGH AND AN UPPER RIDGE BUILDS OVERHEAD. CARIBBEAN... SCATTERED SHOWERS AND ISOLATED TSTMS CONTINUE OVER PORTIONS OF ERN CUBA...JAMAICA AND THE WINDWARD PASSAGE. THIS ACTIVITY IS ASSOCIATED WITH A STALLED FRONTAL BOUNDARY WHICH LIES JUST TO THE N AND AN UPPER DIFFLUENT PATTERN BETWEEN TROUGHING OVER THE NW CARIB AND BROAD RIDGING OVER THE TROPICAL ATLC AND E CARIB. THE REMAINDER OF THE REGION IS RELATIVELY QUIET WITH ONLY TYPICAL PATCHES OF SHALLOW MOISTURE BEING STEERED W ACROSS THE SEA. TRADE WINDS...THE STEERING FOR THE CLOUDS/ISOLATED SHOWERS...ARE BLOWING GENERALLY IN THE 15-25 KT RANGE. LOOKING AHEAD A FEW DAYS...TRADE WINDS ARE EXPECTED TO SLACKEN A LITTLE AS THE STRONG SFC HIGH IN THE NE U.S. SHIFTS E. SCATTERED SHOWERS AND TSTMS ARE LIKELY TO PERSIST AND INCREASE IN COVERAGE ACROSS SIMILAR REGIONS AS TODAY AS THE WEAK LOW-LEVEL BOUNDARY REMAINS NEARLY STATIONARY N OF THE ISLANDS AND THE UPPER TROUGH SHARPENS OVER THE NW CARIB. ATLANTIC... THERE IS ONLY ONE AREA OF UNSETTLED WEATHER TO TALK ABOUT IN THE ATLC BASIN. THE CONTRIBUTING SFC FEATURE IS A STALLED FRONT WHICH ENTERS THE REGION NEAR 32N53W AND EXTENDS SW ALONG 26N68W TO THE SE BAHAMAS. THIS SFC BOUNDARY IS NOT EASY TO LOCATE WITH A MESSY STRUCTURE OF LAYERED CLOUDS AND ONLY A WIND SHIFT FROM ELY TO NELY. LOW-LEVEL CONVERGENCE ALONG WITH UPPER LEVEL SWLY FLOW AND DIFFLUENCE BETWEEN TROUGHING OVER THE WRN ATLC AND RATHER STRONG RIDGING IN THE CENTRAL ATLC IS PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 240 NM EITHER SIDE OF THE FRONT N OF 25N. AN APPROACHING COLD FRONT...JUST N OF THE AREA...IS LINED UP NW OF THE STATIONARY BOUNDARY. THESE BOUNDARIES WILL LIKELY MERGE LATER TODAY/TONIGHT. ELSEWHERE SFC HIGH PRES DOMINATES BOTH TO THE W AND E OF THE FRONT. IN THE W ATLC...A VERY STRONG 1044 MB HIGH IS CENTERED IN THE NE U.S. GENERATING SOME STIFF E/NELY WINDS W OF THE FRONT. PATCHES OF LOW/MID LEVEL CLOUDS ARE BEING STEERED QUICKLY TOWARD THE BAHAMAS AND FLORIDA...LIKELY PRODUCING SOME ISOLATED SHOWERS. IN THE E ATLC...A 1034 MB HIGH CONTROLS THE SFC PATTERN. A FAIRLY TIGHT PRES GRADIENT E OF THE HIGH IS PRODUCING STRONG WINDS ACROSS THE NE PART OF THE DISCUSSION AREA...N OF 28N E OF 28W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW CENTERED NEAR 31N26W IS ROTATING AROUND EXTENSIVE UPPER LEVEL TROUGHING. A SWLY JET HAS BEEN SUPPRESSED S A BIT EXTENDING FROM 6N42W 13N22W ACROSS WRN AFRICA. THIS JET IS AIDING IN THE DEVELOPMENT OF CONVECTION IN THE ITCZ AND SPREADING WIDESPREAD HIGH LEVEL MOISTURE SE OF THE JET AXIS. ELSEWHERE UPPER CONFLUENCE IS LEADING TO ABUNDANT DRY STABLE AIR. $$ CANGIALOSI