000 AXNT20 KNHC 311741 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAY 31 2007 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... A BROAD AREA OF LOW PRESSURE...ANALYZED 1006 MB...IS LOCATED ABOUT 75 MI SE OF COZUMEL MEXICO. THIS LOW SITS ALONG AN ELONGATED SFC TROUGH WHICH STRETCHES FROM NICARAGUA TO THE SRN GULF. THIS LARGE TROUGH OF LOW PRES IS PRODUCING A BIG AREA OF SCATTERED SHOWERS AND TSTMS MOSTLY ALONG AND TO THE E OF THE TROUGH AXIS. THE SHOWER ACTIVITY IS MOST ORGANIZED FROM 16N-23N BETWEEN 79W-87W. KEY WEST DOPPLER RADAR SHOWS SOME OF THIS STRONGER ACTIVITY PULLING N INTO RADAR RANGE. THE OVERALL STRUCTURE OF THE SYSTEM HAS IMPROVED OVER THE PAST DAY OR SO AND FOR THAT REASON THERE IS SOME POTENTIAL FOR TROPICAL DEVELOPMENT OVER THE NEXT DAY OR TWO. THEREAFTER...MODELS SHOW THE LOW TRACKING TO THE N/NE INTO A STRONGLY SHEARED ENVIRONMENT WHICH WOULD FAVOR NON-TROPICAL DEVELOPMENT. REGARDLESS OF WHAT FORMS...TROPICAL OR NON-TROPICAL...ASSOCIATED HEAVY RAINFALL MAY OCCUR ACROSS WRN CUBA AND S FLORIDA OVER THE NEXT COUPLE OF DAYS. ...TROPICAL WAVES... A LOW AMPLITUDE TROPICAL WAVE IS LOCATED ALONG 37W S OF 9N MOVING W ABOUT 15 KT. THIS WEAK WAVE IS A LITTLE MORE EVIDENT THAN IT WAS YESTERDAY ON SAT IMAGES WITH A HINT OF SOME LOW-MID LEVEL TURNING. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM E AND 180 NM W OF THE WAVE AXIS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 5N23W 3N35W 1N40W EQ50W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE AXIS E OF 24W. THIS ACTIVITY IS LIKELY ENHANCED BY A TROPICAL WAVE STILL INLAND OVER W AFRICA. SIMILAR ACTIVITY IS FROM 6N-10N W OF 43W. ...DISCUSSION... THE GULF OF MEXICO... PRONOUNCED UPPER TROUGHING COVERS THE MAJORITY OF THE GULF EXTENDING SWD FROM THE UPPER PLAINS TO AN UPPER LOW IN THE NW GULF NEAR 28N93W CONTINUING INTO THE BAY OF CAMPECHE. THE COMBINATION OF UPPER DIFFLUENCE TO THE E OF THE TROUGH AXIS AND MOIST SWLY FLOW ALOFT IS PULLING MOISTURE NEWD ACROSS THE MID AND E GULF. AVAILABLE DOPPLER RADAR DEPICTS SCATTERED SHOWERS EMBEDDED IN THIS MOISTURE PLUME BUT THE DEEPER...MORE ORGANIZED ACTIVITY IS LOCATED S IN THE CARIB. FOR MORE DETAILS REFER TO THE SPECIAL FEATURE SECTION. AT THE SFC...HIGH PRES CENTERED OFF THE MID-ATLANTIC COAST IS PRODUCING MODERATE ELY TRADES ACROSS THE E GULF AND THE FL STRAITS. THESE WINDS LIGHTEN AND VEER TOWARD THE NE IN THE W GULF IN RESPONSE TO THE NRN EXTENSION OF THE SFC TROUGH...ASSOCIATED WITH THE LOW PRES SYSTEM IN THE CARIB. THE FORECAST OVER THE NEXT DAY OR TWO DEPENDS ON THE TRACK OF THE LOW PRES SYSTEM IN THE CARIB. WHILE THERE ARE MANY UNCERTAINTIES...IT DOES LOOK LIKELY THAT MOISTURE WILL CONTINUE TO INCREASE INTO THE ERN HALF OF THE GULF FRI AND SAT AS THE LOW HEADS IN THAT DIRECTION. THE CARIBBEAN SEA... THE MAIN AREA OF INTEREST IS IN THE NW CARIB ASSOCIATED WITH A LARGE LOW PRES SYSTEM...FOR DETAILS REFER TO THE SPECIAL FEATURE SECTION ABOVE. ELSEWHERE...THE TAIL END OF A LARGE ATLC TROUGH CLIPS THE EXTREME NE PORTION OF THE AREA. WHILE THE ASSOCIATED SYNOPTIC SFC BOUNDARIES HAVE PULLED N...LOW-LEVEL CONFLUENCE AND UPPER DIFFLUENCE IS PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE NRN LEEWARD ISLANDS...VIRGIN ISLANDS AND PUERTO RICO. A WEAK LOW-LEVEL TROUGH IS ANALYZED ALONG 76W. THIS FEATURE IS AIDING IN SMALL PATCHES OF SCATTERED MODERATE CONVECTION OVER COLOMBIA AND THE SRN CARIB BETWEEN 73W-78W S OF 14N. OTHERWISE...AN UPPER HIGH CENTERED NEAR 17N80W IS KEEPING CONDITIONS RELATIVELY QUIET ELSEWHERE. THE ATLANTIC OCEAN... A VERY BROAD DEEP LAYER TROUGH COVERS MUCH OF THE W AND CENTRAL ATLC WITH THE AXIS EXTENDING FROM 32N58W TOWARD THE NRN LEEWARD ISLANDS. PLENTY OF DRY AIR ALOFT COVERS THE REGION N OF 23N BETWEEN 57W-75W KEEPING THE REGION WITH ONLY SCATTERED LOW-LEVEL STRATOCUMULUS CLOUDS WHILE A MID-HIGH LEVEL CLOUD DECK...ASSOCIATED WITH DEBRIS MOISTURE FROM THE LARGE LOW PRES SYSTEM IN THE CARIB...HAS PUSHED INTO THE REGION W OF 75W. THE UPPER TROUGH IS PROVIDING SUPPORT FOR TWO SFC BOUNDARIES. ONE IS ANALYZED AS A TROUGH...LACKING THERMAL STRUCTURE...EXTENDING ALONG 32N52W 26N61W. LATEST VIS IMAGES SUGGEST THAT THERE COULD BE A WEAK LOW ALONG THIS TROUGH NEAR 28N. REGARDLESS...ONLY LOW CLOUDS AND SHALLOW SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE AXIS. THE SECOND BOUNDARY IS A COLD FRONT WHICH BARELY ENTERS THE AREA NEAR 32N58W...MOSTLY ACTING AS A SURGE IN THE NLY FLOW. MUCH MORE SIGNIFICANT MOISTURE IS LOCATED FURTHER E IN DIFFLUENT ZONE BETWEEN THE TROUGH AND A RIDGE TO ITS E. IR IMAGES SUGGEST THAT SCATTERED SHOWERS AND ISOLATED TSTMS ARE POSSIBLE WITHIN 300 NM E OF A LINE ALONG 32N51W 24N58W 21N69W. THE REMAINDER OF THE REGION IS DOMINATED BY A 1027 MB HIGH NEAR 32N25W. THIS HIGH PRES SYSTEM IS SUPPLYING FAIR WEATHER AND MODERATE TRADES ACROSS THE TROPICS. IN THE MID AND UPPER LEVELS...A HIGHLY ELONGATED RIDGE/TROUGH/RIDGE PATTERN HAS SET UP E OF 50W. HOWEVER...LITTLE SIGNIFICANT WEATHER IS BEING GENERATED IN THIS STABLE ENVIRONMENT. $$ CANGIALOSI