000 AXNT20 KNHC 271146 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI SEP 27 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 20N49W TO 10N49W MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS BENEATH AN UPPER RIDGE ENHANCING LARGE CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 10N-24N BETWEEN 44W-52W. TROPICAL WAVE APPROACHING THE LESSER ANTILLES EXTENDS FROM 18N59W TO 9N56W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS MOVING TO THE W OF AN UPPER LOW WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 90 NM OF THE WAVE BETWEEN 10N-16N. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W THROUGH A WEAK 1010 MB LOW OFF THE COAST NEAR 12N17W THEN TO 9N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 7N30W TO 7N47W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-13N E OF 23W TO THE COAST OF W AFRICA. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2N-9N BETWEEN 28W-34W AND FROM 5N-10N BETWEEN 34W-45W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE DOMINATES THE N GULF ANCHORED OVER CENTRAL TEXAS. A WEAK SHORTWAVE UPPER TROUGH CUTS E/W ACROSS THE CENTRAL GULF FROM A BROAD UPPER TROUGH IN THE W ATLC ACROSS THE STRAITS OF FLORIDA/FLORIDA KEYS TO TAMPICO MEXICO. THE BROAD UPPER TROUGH IS SUPPORTING A FRONTAL SYSTEM THAT EXTENDS A COLD FRONT AT 27/0900 UTC INTO THE GULF ACROSS S FLORIDA FROM MIAMI TO EVERGLADES CITY TO 25N86W WHERE IT BECOMES STATIONARY TO 25N93W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM S OF THE STATIONARY PORTION OF THE FRONT WITH ISOLATED SHOWERS WITHIN 90 NM S AND 75 NM N OF THE COLD FRONT. ISOLATED SHOWERS ARE POSSIBLE OVER THE NE GULF WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE WITHIN 30 NM ALONG THE COAST OF MEXICO IN THE BAY OF CAMPECHE. WATER VAPOR IMAGERY INDICATED DRY STABLE AIR COVERS THE GULF N OF 23N KEEPING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES THIS MORNING. THE WEAK FRONT WILL SINK SE AND REACH THE STRAITS OF FLORIDA BY THIS AFTERNOON THEN DRIFT SE INTO NW CUBA OVER THE WEEKEND. HIGH PRESSURE BUILDING ACROSS THE SE CONUS TODAY THROUGH SAT. A WEAK SURFACE RIDGE WILL DOMINATE THE GULF THROUGH TUE. CARIBBEAN SEA... AN UPPER RIDGE ANCHORED NEAR MEXICO CITY MEXICO EXTENDS A RIDGE AXIS ACROSS THE YUCATAN PENINSULA TO CENTRAL CUBA COVERING THE W CARIBBEAN W OF 78W. A SECOND UPPER RIDGE IS ANCHORED OVER SOUTH AMERICA COVERING THE S CARIBBEAN S OF 17N BETWEEN 64W-78W INDUCING AN UPPER TROUGH THAT EXTENDS FROM E CUBA/WINDWARD PASSAGE TO NE HONDURAS AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N BETWEEN 73W-78W. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 11N73W ALONG 11N77W TO ACROSS COSTA RICA NEAR 10N83W GENERATING CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 13N W OF 75W TO INLAND OVER PANAMA AND TO THE COAST OF NICARAGUA. EASTERLY TRADE WINDS WILL PREVAIL THROUGH TUE. BROAD AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE SW CARIBBEAN DURING THE WEEKEND. HISPANIOLA... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS REMAIN OVER THE GULF OF GONAVE THIS MORNING WHILE THE SKIES REMAIN CLEAR OVER THE DOMINICAN REPUBLIC. EASTERLY FLOW ALOFT IS BEGINNING TO GIVE WAY TO SOUTHERLY FLOW AS THE UPPER TROUGH OVER THE W ATLC WILL DIG S OVER THE N CARIBBEAN THROUGH THE WEEKEND. THIS WILL POSSIBLY INCREASE OR INTENSIFY AFTERNOON SHOWERS/THUNDERSTORMS. ATLANTIC OCEAN... AN UPPER TROUGH COVERS THE W ATLC N OF 23N W OF 70W TO OVER THE FLORIDA PENINSULA SUPPORTING A COLD FRONT THAT AT 27/0900 UTC ENTERS THE REGION THROUGH A 1000 MB LOW NEAR 32N61W ALONG 28N67W TO 28N72W WHERE IT BECOMES NEARLY STATIONARY TO A 1006 MB LOW NEAR 29N76W THEN COLD FRONT EXTENDS ACROSS FLORIDA NEAR MIAMI TO EVERGLADES CITY THEN INTO THE GULF OF MEXICO. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 24N-30N BETWEEN 58W-78W. AN UPPER RIDGE STRETCHES FROM THE N/CENTRAL ATLC TO HISPANIOLA ENHANCING THE ACTIVITY ABOVE. AN UPPER LOW IS BETWEEN THE TROPICAL WAVES NEAR 21N54W AND COUPLED WITH THE UPPER RIDGE TO THE E ARE ENHANCING THE ACTIVITY ASSOCIATED WITH THE EASTERN MOST TROPICAL WAVE. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH NEAR 23N38W. THE 1000 MB LOW WILL MOVE E-NE AND EXIT THE REGION THROUGH SAT WHILE DRAGGING THE FRONT ACROSS W ATLC N OF 27N.THE 1006 MB LOW WILL MOVE SLOWLY E-SE THROUGH SAT THEN ACCELERATE NE SAT NIGHT THROUGH MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW