000 AXNT20 KNHC 041730 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAY 04 2006 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...WEATHER OBSERVATIONS... RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 2N20W EQ30W EQ50W. THE ITCZ IS FAIRLY ACTIVE W OF 30W...WHERE NUMEROUS SHOWERS AND EMBEDDED TSTMS CONTINUE WITHIN 200 NM ON EITHER SIDE OF THE AXIS. SOME OF THIS ACTIVITY IS SPREADING NWD CARRIED BY SWLY UPPER LEVEL FLOW ON THE WESTERN PERIPHERY OF A TROPICAL ANTICYCLONE. A FEW SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION HAS DEVELOPED WITHIN 90 NM OF THE AXIS BETWEEN 11W-17W. PATCHES OF SCATTERED MODERATE CONVECTION IS MOVING OFF THE COAST OF AFRICA E OF 4W FROM THE EQUATOR TO 5N. ...DISCUSSION... THE GULF OF MEXICO... NEARLY ZONAL UPPER LEVEL FLOW COVERS THE GULF WITH PATCHY HIGH CLOUDINESS ACROSS MEXICO AND THE NW PORTION OF THE AREA. DRY/STABLE AIR ALOFT IS OVER THE E GULF AND FLORIDA. AT THE SFC...A 1019 MB HIGH IS CENTERED 150 NM OFF THE COAST OF TAMPA NEAR 28N86W SUPPLYING PLENTY OF FAIR WEATHER ACROSS MUCH OF THE AREA. FAIRLY LIGHT WINDS EXTEND ACROSS THE GULF EXCEPT FOR THE W GULF...W OF 94W...WHERE S RETURN FLOW BREEZES ARE NEAR 15 KT. SFC RIDGING WILL SUPPORT FAIR WEATHER THRU SAT. THEREAFTER...SFC HIGH PRES WILL PULL TO THE E OF THE AREA AS A WEAK COLD FRONT ENTERS THE N GULF ON SUN BRINGING THE NEXT CHANCE OF ORGANIZED RAINFALL. THE CARIBBEAN SEA... A BROAD UPPER LEVEL TROPICAL ANTICYCLONE IS CENTERED E OF TRINIDAD NEAR 10N55W. MUCH OF THE CARIBBEAN IS ON THE NW PERIPHERY OF THIS TROPICAL RIDGE WITH SW TO W UPPER LEVEL WINDS. BROKEN PATCHES OF MID-UPPER LEVEL MOISTURE IS STREAMING AROUND THE UPPER HIGH FROM S AMERICA TO THE GREATER ANTILLES AND THEN TOWARDS THE E ATLC WITHIN 200 NM TO THE RIGHT OF A LINE 11N77W 19N68W 17N52W. SCATTERED SHOWERS AND SOME SMALL POCKETS OF ISOLATED TSTMS ARE EMBEDDED IN THIS PLUME OF MOISTURE. AT THE SFC...A WEAK TROUGH EXTENDS FROM 15N77W TO THE SW COAST OF HAITI GENERATING LOW-MID LEVEL CLOUDS AND SHOWERS WITHIN 75 NM OF THE TROUGH AXIS. THE TAIL END OF A CENTRAL ATLC TROUGH CUTS THRU THE LEEWARD ISLANDS ALONG 20N62W 16N65W. MULTILAYER CLOUDS AND SHOWERS ARE WITHIN 100 NM OF THE TROUGH AXIS. THIS FEATURE HAS BEEN MOVING VERY SLOWLY EWARD OVER THE PAST FEW DAYS. BASED ON THE SATELLITE SIGNATURE THE TAIL END OF THE TROUGH IS SHOWING SOME SIGNS OF WEAKENING. GLOBAL MODELS DO ANTICIPATE THE SFC FEATURE TO LIFT N OF THE CARIBBEAN THIS WEEKEND. HOWEVER...THERE MAY STILL BE SOME REMNANT MOISTURE ACROSS THE NEMOST CARIBBEAN ISLANDS FOR THE NEXT COUPLE OF DAYS. THE ATLANTIC OCEAN... A DEEP-LAYER TROUGH COVERS MUCH OF THE W ATLC WITH AN UPPER LOW CENTERED NEAR 32N65W. UPPER LEVEL CONFLUENCE TO THE S OF THE UPPER LOW IS PRODUCING AN AREA OF STRONG SUBSIDENCE FROM 24N-29N BETWEEN 53W-78W. AT THE SFC...WEAK HIGH PRES IS CENTERED OVER THE BAHAMAS. A WEAK TROUGH STRETCHES FROM A 1000 MB LOW S OF NOVA SCOTIA AND ENTERS THE AREA ALONG 32N67W 29N73 31N77W. SMALL PATCHES OF MULTILAYER CLOUDS AND SHOWERS ARE NEAR THE TROUGH. A SLIGHT WIND INCREASE IS OBSERVED BEHIND THE SFC TROUGH. A MORE SIGNIFICANT FEATURE IS A SLOW MOVING COLD FRONT THAT ENTERS THE DISCUSSION AREA ALONG 32N49W 27N55W THEN AS A SFC TROUGH TO THE VIRGIN ISLANDS. MULTILAYER CLOUDS AND SHOWERS STRETCH A FEW HUNDRED NM E OF THE COLD FRONT AND WITHIN 175 NM ON EITHER SIDE OF THE SFC TROUGH. THIS FRONTAL BOUNDARY WILL BEGIN TO FALL APART S OF 32N THIS WEEKEND AS ITS UPPER LEVEL SUPPORT FLATTENS AND PULLS NEWARD. FARTHER EAST...A 1024 MB HIGH CENTERED NEAR 31N34W DOMINATES THE E ATLC. SOME UPPER LEVEL MOISTURE IS SPILLING INTO THE SFC RIDGE W OF 37W N OF 24N. FAIR WEATHER IS THE RULE FOR THE REST OF E ATLC N OF 10N. IN THE UPPER LEVELS...GENTLE MID TO UPPER LEVEL RIDGING STRETCHES FROM A BROAD TROPICAL RIDGE NEAR 10N55W TO 32N35W. GRADUAL UPPER LEVEL TROUGHING RUNS FROM FROM NORTHERN MOROCCO TO 20N28W. $$ CANGIALOSI