000 AXNT20 KNHC 151031 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT JUN 15 2013 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA... NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 23N72W OVER THE TURKS AND CAICOS INTO THE CARIBBEAN ACROSS W HAITI TO OFF THE COAST OF COLOMBIA NEAR 12N74W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS ENHANCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 17N-24N BETWEEN 67W-75W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W AND CONTINUES TO 8N22W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N25W 6N35W 7N42W TO INLAND OVER SOUTH AMERICA NEAR 4N51W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-8N BETWEEN 27W-35W...FROM 4N-9N BETWEEN 35W-46W...AND 2N-7N BETWEEN 47W-52W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH COVERS MOST OF THE GULF E OF 94W INTO THE W ATLC SUPPORTING A COLD FRONT THAT AT 15/0900 UTC DRAPES ACROSS THE N GULF ACROSS FLORIDA NEAR CAPE CANAVERAL INTO THE GULF NEAR CEDAR KEY TO APALACHICOLA BAY WHERE IT BECOMES STATIONARY ALONG 29N89W CONTINUING INLAND OVER LOUISIANA NEAR ATCHAFALAYA BAY. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 75/90 NM S OF THE FRONT E OF 90W TO INLAND OVER FLORIDA. AN UPPER RIDGE COVERS THE REMAINDER OF THE GULF ANCHORED OVER SW MEXICO AND EXTENDS A RIDGE AXIS N OVER THE CENTRAL PLAIN STATES. A WEAK SURFACE RIDGE EXTENDS FROM THE ATLC ACROSS S FLORIDA WITH A 1016 MB HIGH NEAR 25N89W. THIS IS LEAVING THE REMAINDER OF THE GULF WITH MOSTLY CLEAR SKIES THIS MORNING. THE WEAKENING COLD FRONT WILL DRIFT S THIS MORNING BEFORE DISSIPATING FROM CENTRAL FLORIDA TO SE LOUISIANA LATE THIS AFTERNOON. THE SURFACE RIDGE WILL SHIFT N SUN THROUGH TUE. A TROPICAL WAVE WILL MOVE THROUGH THE STRAITS OF FLORIDA SUN THEN SHIFT MORE W-NW ACROSS THE YUCATAN PENINSULA AND GULF WATERS S OF 25N LATE MON THROUGH TUE THEN ACROSS THE SW GULF WED. A LOW IS EXPECTED TO DEVELOP ALONG THE WAVE OVER THE SE BAY OF CAMPECHE WED. CARIBBEAN SEA... AN UPPER TROUGH OVER THE GULF OF MEXICO DIPS S OVER THE NW CARIBBEAN TO OVER HONDURAS W OF THE CAYMAN ISLANDS. THIS IS DRAWING DRY STABLE AIR OVER THAT AREA WITH CLEAR SKIES. A LARGE UPPER HIGH DOMINATES THE REMAINDER OF THE CARIBBEAN ANCHORED OVER THE WINDWARD ISLANDS AND EXTENDS E INTO THE TROPICAL ATLC WITH A RIDGE AXIS EXTENDING N OVER THE W ATLC. THE UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM THE TIP OF NICARAGUA/HONDURAS TO ACROSS CUBA NEAR 20N75W INCLUDING JAMAICA. THE REMAINDER OF THE ACTIVITY IN THE N/CENTRAL CARIBBEAN IS ASSOCIATED WITH THE TROPICAL WAVE. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 9N75W ALONG 10N90W THEN ACROSS COSTA RICA NEAR 10N84W INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N BETWEEN 75W-82W. THE EASTERLY TRADE WINDS ARE USHERING IN SOME LOW LEVEL SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE E CARIBBEAN S OF 17N BETWEEN 63W-71W. TROPICAL WAVE WILL MOVE W ACROSS THE CENTRAL CARIBBEAN THROUGH TODAY THEN ACROSS THE W CARIBBEAN TONIGHT THROUGH MON AND OVER THE YUCATAN PENINSULA EARLY TUE. HISPANIOLA... THE ACTIVITY OVER HISPANIOLA IS ASSOCIATED WITH THE TROPICAL WAVE CURRENTLY MOVING ACROSS THE ISLAND. THE SHOWERS WILL CONTINUE THROUGH THIS MORNING. THE TROPICAL WAVE WILL MOVE W OF HAITI LATER THIS MORNING AND WITH THE DAYTIME HEATING IN THE AFTERNOON COUPLED WITH THE DEEP LAYER MOISTURE PRESENT WILL REGENERATE THUNDERSTORMS THIS AFTERNOON. DEEP LAYERED MOISTURE WILL LINGER OVER THE ISLAND AS THE UPPER TROUGH TO THE W MOVES E TOWARD THE ISLAND INCREASING THE CHANCES OF SHOWERS/ THUNDERSTORMS THROUGH EARLY NEXT WEEK. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF 68W SUPPORTING A COLD FRONT THAT 15/0900 UTC ENTERS THE REGION NEAR 32N69W AND CONTINUES ALONG 28N78W OVER FLORIDA NEAR CAPE CANAVERAL THEN INTO THE GULF OF MEXICO. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 90/120 NM SE OF THE FRONT. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS AN UPPER RIDGE AXIS N ACROSS THE VIRGIN ISLANDS TO BEYOND 32N62W PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/THUNDERSTORMS WITHIN 60 NM OF LINE FROM 25N74W TO 31N65W. THE TROPICAL WAVE IS TO THE S OF THE ABOVE ACTIVITY. THE REMAINDER OF THE ATLC IS DOMINATED BY A LARGE SURFACE RIDGE AND BENIGN UPPER FEATURES ANCHORED BY A 1028 MB HIGH LOCATED NEAR 32N42W AND WITH A WEAK RIDGE EXTENDING S OF THE FRONT INTO THE GULF OF MEXICO. THIS IS KEEPING THE REMAINDER OF THE ATLC TRANQUIL THIS MORNING. THE FIRST VISIBLE SATELLITE IMAGERY SHOWS A BROAD SWATH OF SAHARAN DUST COVERING THE ATLC MAINLY BETWEEN 10N-20N FROM AFRICA INTO THE CARIBBEAN. THE N PORTION OF A TROPICAL WAVE WILL MOVE ACROSS THE SW ATLC THROUGH TONIGHT BEFORE MOVING ACROSS STRAITS OF FLORIDA SUN. A SURFACE RIDGE IN THE GULF OF MEXICO WILL WEAKEN AND MOVE E-SE AHEAD OF A COLD FRONT THAT WILL SHIFT E-SE AND EXTEND FROM 32N62W TO THE NW BAHAMAS THIS EVENING THEN STALL AND DISSIPATE AS IT MOVES INTO THE CENTRAL ATLC SUN. HIGH PRESSURE WILL BUILD BEHIND THE FRONT WITH A RIDGE FROM NEAR BERMUDA TO CENTRAL FLORIDA MON THROUGH WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW