000 AXNT20 KNHC 270534 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 20N48W TO 10N48W 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 SCATTERED STRONG CONVECTION FROM 10N-23N BETWEEN 44W-51W. TROPICAL WAVE APPROACHING THE LEEWARD ISLANDS EXTENDS FROM 19N57W TO 9N55W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS MOVING W OF THE UPPER LOW WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 90 NM OF THE WAVE BETWEEN 10N-17N. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 13N16W TO 12N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 7N25W 5N33W TO 7N42W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60/75 NM OF LINE FROM 14N20W 10N19W TO THE COAST OF GUINEA NEAR 10N14W AND WITHIN 60 NM OF LINE FROM 9N27W TO 7N32W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 11N-15N E OF 19W TO THE COAST OF W AFRICA AND WITHIN 30 NM OF LINE FROM 5N34W TO 9N40W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE DOMINATES THE N GULF ANCHORED OVER THE RIO GRAND NEAR EAGLE PASS TEXAS. A WEAK SHORTWAVE UPPER TROUGH CUTS E/W ACROSS THE CENTRAL GULF FROM A BROAD UPPER TROUGH IN THE W ATLC ACROSS S FLORIDA TO TAMPICO MEXICO. THE BROAD UPPER TROUGH IS SUPPORTING A COLD FRONT THAT AT 27/0300 UTC ENTERS THE GULF ACROSS FLORIDA NEAR NAPLES TO 26N85W THEN DISSIPATES TO 26N89W. WATER VAPOR IMAGERY INDICATED DRY STABLE AIR COVERS THE GULF N OF 23N...THUS ONLY ISOLATED SHOWERS ARE POSSIBLE ALONG THE IMMEDIATE FRONT. A SECOND UPPER RIDGE COVERS THE S GULF ANCHORED NEAR MEXICO CITY MEXICO AND EXTENDING A RIDGE AXIS E ACROSS THE YUCATAN PENINSULA TO W CUBA. ISOLATED SHOWERS ARE POSSIBLE OVER THE NE GULF WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS POSSIBLE WITHIN 45 NM ALONG THE COAST OF MEXICO FROM TAMPICO TO VERACRUZ. THIS IS LEAVING MOST OF THE GULF UNDER CLEAR SKIES TONIGHT. THE WEAK FRONT WILL MOVE ACROSS THE SE GULF TONIGHT REACHING THE STRAITS OF FLORIDA FRI MORNING. HIGH PRESSURE WILL BUILD ACROSS SE CONUS FRI AND SAT. THE SURFACE RIDGE WILL THEN DOMINATE THE GULF THROUGH TUE. CARIBBEAN SEA... AN UPPER RIDGE ANCHORED NEAR MEXICO CITY MEXICO EXTENDS A RIDGE AXIS ACROSS THE YUCATAN PENINSULA TO OVER W CUBA COVERING THE W CARIBBEAN W OF 80W. A SECOND UPPER RIDGE IS ANCHORED OVER SOUTH AMERICA COVERING THE S CARIBBEAN S OF 17N BETWEEN 64W-80W INDUCING AN UPPER TROUGH THAT EXTENDS FROM E CUBA TO NE HONDURAS AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N BETWEEN 72W-80W INCLUDING MOST OF HAITI AND E CUBA. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 8N75W ALONG 10N80W TO ACROSS COSTA RICA NEAR 10N83W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 13N W OF 71W TO INLAND OVER COLOMBIA TO 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 ARE OVER HAITI AND THE GULF OF GONAVE TONIGHT 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 W CARIBBEAN THROUGH THE WEEKEND. THIS WILL POSSIBLY INCREASE OR INTENSIFY AFTERNOON SHOWERS/THUNDERSTORMS. ATLANTIC OCEAN... AN UPPER TROUGH COVERS THE W ATLC N OF 24N W OF 70W TO OVER THE FLORIDA PENINSULA SUPPORTING A COLD FRONT THAT AT 27/0300 UTC ENTERS THE REGION THROUGH A 1000 MB LOW JUST S OF BERMUDA ALONG 30N67W TO 28N70W WHERE IT BECOMES NEARLY STATIONARY TO A 1007 MB LOW NEAR 29N76W THEN COLD FRONT EXTENDS ACROSS FLORIDA NEAR BOCA RATON TO NAPLES THEN INTO THE GULF OF MEXICO. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 25N TO THE FRONT BETWEEN 60W-79W. AN UPPER RIDGE STRETCHES FROM THE N/CENTRAL ATLC TO THE WINDWARD PASSAGE ENHANCING THE ACTIVITY ABOVE. AN UPPER LOW IS BETWEEN THE TROPICAL WAVES NEAR 20N53W 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 1021 MB HIGH NEAR 25N37W. THE 1000 MB LOW WILL MOVE E-NE WHILE DRAGGING THE FRONT ACROSS ATLC N OF 27N. THE 1007 MB LOW WILL DRIFT SE THROUGH SAT THEN ACCELERATE NE SUN AND MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW