000 AXNT20 KNHC 172346 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 33W S OF 11N MOVING W 5-10 KT. A LOW-AMPLITUDE INVERTED-V SIGNATURE IS OBSERVED ON LATEST VISIBLE SATELLITE IMAGERY FOR THE DAY. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM EITHER SIDE OF AXIS S OF 8N. THE WAVE IS WELL DEFINED ON THE MIMIC-TPW PRODUCT FROM CIMSS. THE HOVMOLLER DIAGRAM ALSO SHOWS THE WWD PROPAGATION OF THIS WAVE. TROPICAL WAVE IS ALONG 55W/56W S OF 11N MOVING W 10 KT. THE WAVE COUPLED WITH THE ITCZ IS GENERATING CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION OVER THE GUYANAS REGION AND COASTAL WATERS. A BULGE OF MOISTURE IS SEEN ON THE MIMIC-TPW PRODUCT ASSOCIATED WITH THE WAVE. TROPICAL WAVE IN THE SW CARIBBEAN ALONG 79W/80W S OF 10N MOVING W NEAR 10 KT. THE WAVE AXIS CROSSES THE ISTHMUS OF PANAMA INTO THE EPAC. MODERATE TO STRONG CONVECTION IS BEHIND THE WAVE AFFECTING EASTERN PANAMA AND NORTHERN COLOMBIA. A DIFFLUENT PATTERN ALOFT IS ENHANCING THIS CONVECTIVE ACTIVITY. ..THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 4N20W 5N30W 3N45W AND INTO NE BRAZIL NEAR 2N52W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-5N BETWEEN 13W AND 16W...AND NEAR 4N21W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM N OF AXIS BETWEEN 25W-30W. SIMILAR CONVECTION IS WITHIN 200 NM N OF THE AXIS BETWEEN 40W-49W. ...DISCUSSION... GULF OF MEXICO... A WEAK STATIONARY FRONT STRETCHES ACROSS THE GULF THIS EVENING. AS OF 21Z...THE FRONT ENTERS THE REGION THROUGH CENTRAL FLORIDA AND EXTENDS ALONG THE CENTRAL GULF NEAR 25N90W TO THE BAY OF CAMPECHE NEAR COATZACOALCOS WHERE THERE IS A CLUSTER OF MODERATE CONVECTION. MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS ARE BEHIND THE FRONTAL BOUNDARY COVERING A GOOD PORTION OF THE GULF. THE FRONT WILL WEAKEN AND DISSIPATE SUN WITH A WEAK SFC HIGH PRES BUILDING ALONG THE CENTRAL GULF. AHEAD OF THE FRONT...SFC RIDGING IS PROVIDING A VERY WARM AND HUMID DAY OVER SOUTH-CENTRAL FLORIDA AND THE REMAINDER OF THE GULF WATERS. UNUSUAL SWLY WINDS ASSOCIATED WITH THE SFC RIDGE ARE BLOWING OVER SOUTH FLORIDA ALLOWING TEMPERATURES TO CLIMB INTO THE 90S ALONG THE EAST COAST WITH MIAMI BREAKING THE RECORD MAX TEMP FOR THIS DATE...REACHING 94 DEGREES (PREVIOUS RECORD WAS 93 IN 1985). ALOFT...A LARGE UPPER-LEVEL HIGH REMAINS CENTERED OVER THE CARIBBEAN SEA NOW NEAR JAMAICA EXTENDING A RIDGE OVER MOST OF THE GULF...BUT PARTICULARLY THE EASTERN HALF. A DEEP LAYERED TROUGH/LOW IS OVER TEXAS AND N MEXICO. SWLY WINDS BETWEEN THESE TWO UPPER LEVEL FEATURES CONTINUE TO TRANSPORT ABUNDANT UPPER LEVEL MOISTURE FROM THE EPAC THROUGH MEXICO INTO THE GULF WATERS AND THE SE CONUS. THESE WINDS ARE ALSO ENHANCING CONVECTION OVER SOUTH-CENTRAL MEXICO AND THE BAY OF CAMPECHE. CARIBBEAN SEA... A SFC TROUGH...REMNANTS OF A FRONTAL BOUNDARY...EXTENDS ACROSS THE CARIBBEAN FROM THE VIRGIN ISLANDS...OVER THE SOUTHERN TIP OF HISPANIOLA...AND ACROSS JAMAICA. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH. A PLUME OF TRANSVERSE HIGH CLOUDS EXTENDS FROM THE SE CARIBBEAN THROUGH THE LESSER ANTILLES INTO THE TROPICAL ATLC ASSOCIATED WITH STRONG SWLY UPPER LEVEL WINDS. OTHERWISE... THE REMAINDER OF THE REGION IS EXPERIENCING FAIR WEATHER UNDER THE INFLUENCE OF A MID/UPPER RIDGE ANCHORED ON A HIGH NEAR JAMAICA AND UPPER TROUGHING OVER THE E CARIBBEAN. WEAK HIGH PRES N OF THE AREA COMBINED WITH THE REMNANTS OF THE FRONT IS PRODUCING LIGHT TO MODERATE TRADE WINDS ACROSS THE REGION. ATLANTIC OCEAN... A COUPLE OF COLD FRONTS ARE OVER THE FORECAST REGION. THE FIRST ONE ENTERS THE AREA NEAR 31N70W THEN CONTINUES SW TO CENTRAL FLORIDA WHERE IT BECOMES STATIONARY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 120 NM AHEAD OF THE BOUNDARY N OF 29N. EXPECT THE FRONT TO MOVE RAPIDLY E AND DISSIPATE LATE TONIGHT. MOSTLY CLEAR CONDITIONS HAVE MOVED INTO THE W ATLC BEHIND THE FRONT. FARTHER EAST...A WEAKER COLD FRONT ENTERS THE CENTRAL ATLC NEAR 31N44W AND EXTENDS ALONG 28N46W TO 23N53W WHERE IT CONTINUES AS A SFC TROUGH OVER THE VIRGIN ISLANDS AND INTO THE CARIBBEAN SEA. MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS ARE WITHIN 200 NM AHEAD OF THE FRONT N OF 24N. A LARGE SFC RIDGE ANCHORED BY A 1025 MB SFC HIGH SOUTH OF THE AZORES DOMINATES THE REMAINDER OF THE ATLC. ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE DISCUSSION AREA. THE UPPER TROUGH OVER THE CENTRAL ATLC SUPPORTS THE WEAKER COLD FRONT. OVER THE DEEP TROPICS...AN ELONGATED RIDGE WITH AXIS ALONG 10N REMAINS IN PLACE. $$ GR