000 AXNT20 KNHC 180538 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI OCT 18 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 WAS ADDED TO THE 18/0000 UTC ANALYSIS INLAND ALONG THE COAST OF AFRICA BASED ON THE GFS GLOBAL MODEL AND THE TOTAL PRECIPITABLE WATER IMAGERY ALONG 16W N OF 8N. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 90/120 NM OF THE WAVE BETWEEN 8N-11N. TROPICAL WAVE EXTENDS FROM 14N46W TO 5N50W MOVING W-NW 15-20 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 75 NM OF LINE FROM 9N47W 10N51W TO 8N53W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-13N BETWEEN 47W-50W. TROPICAL WAVE E OF THE LESSER ANTILLES EXTENDS FROM 15N58W TO 7N58W MOVING W 10-15 KT. THE N PORTION OF THE WAVE HAS BROKEN OFF AND IS NOW DEPICTED AS A SURFACE TROUGH THAT EXTENDS FROM 22N49W TO 15N51W. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 13N-15N BETWEEN 57W-61W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO E OF THE NEWLY ADDED TROPICAL WAVE. THE ITCZ BEGINS W OF THE WAVE NEAR 13N20W AND CONTINUES ALONG 10N25W 8N35W TO 11N44W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-10N BETWEEN 25W- 36W AND FROM 6N-14N BETWEEN 36W-46W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER TROUGH THAT COVERS THE NE CONUS IS SUPPORTING A COLD FRONT THAT ENTERS THE GULF OVER THE FLORIDA PANHANDLE NEAR PANAMA CITY AND CONTINUES ALONG 27N89W 25N95W TO THE COAST OF MEXICO NEAR TUXPAN. ISOLATED SHOWERS ARE W OF THE FRONT TO A LINE FROM VERMILION BAY LOUISIANA TO CORPUS CHRISTI TEXAS. A BROAD UPPER RIDGE DOMINATES THE GULF WATERS ANCHORED IN THE SE GULF NEAR 24N83W. THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES TONIGHT. COLD FRONT IS EXPECTED TO DRIFT SLOWLY SE AND BECOME NEARLY STATIONARY FRI. A REINFORCING SURGE OF NORTHERLY FLOW WILL ALLOW THE FRONT TO BRIEFLY PUSH S AGAIN FRI NIGHT AND SAT. THE SW PORTION OF THE FRONT WILL BEGIN TO LIFT BACK N AS A WARM FRONT FRI EVENING INTO SAT. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE NW CARIBBEAN NW OF LINE FROM CUBA NEAR 20N76W TO GUATEMALA NEAR 16N89W. AN UPPER LOW IS CENTERED INLAND OVER NICARAGUA NEAR 14N84W COVERING THE CARIBBEAN WATERS FROM 11N-16N BETWEEN 80W-86W. THE UPPER TROUGH OVER THE W ATLC EXTENDS ACROSS THE NE CARIBBEAN N OF 14N E OF 76W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 14N- 17N BETWEEN 64W-73W. AN UPPER RIDGE COVERS THE SE CARIBBEAN S OF 14N W OF 80W AND ANCHORED INLAND OVER VENEZUELA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 14N BETWEEN 63W-74W. THE MONSOON TROUGH EXTENDS FROM COLOMBIA ACROSS PANAMA NEAR 9N80W TO OVER COSTA RICA NEAR 10N83W GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 11N E OF 80W AND S OF 10N W OF 80W. WEAK PRESSURE PATTERN WILL PERSIST THROUGH TUE. TROPICAL WAVE ENTER THE CARIBBEAN FRI MOVING NW SAT BEFORE DISSIPATING SUN. A SECOND TROPICAL WAVE WILL MOVE ACROSS THE S CARIBBEAN SUN THROUGH TUE. HISPANIOLA... CURRENTLY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALONG THE N COAST OF THE ISLAND WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER SE HAITI. THE UPPER TROUGH GENERATING THIS ACTIVITY IS BEGINNING TO SHIFT E GIVING THE ISLAND A MORE NORTHERLY FLOW ALOFT. THE TROPICAL WAVE E OF THE LESSER ANTILLES WILL CLIP THE ISLAND ON SAT NIGHT INTO SUN BEFORE IT DISSIPATES INCREASING THE CHANCES OF WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS. DAYTIME HEATING PRODUCING AFTERNOON SHOWERS/ISOLATED THUNDERSTORMS REMAIN A POSSIBILITY. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF 70W. A NARROW UPPER TROUGH COVERS THE REMAINDER OF THE W ATLC EXTENDING FROM AN UPPER LOW NEAR 28N64W ACROSS E HISPANIOLA INTO THE CENTRAL CARIBBEAN SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 29N69W ACROSS THE BAHAMA ISLANDS TO THE COAST OF CUBA NEAR 21N75W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 19N-28N BETWEEN 59W-68W AND FROM 22N TO ALONG THE N COAST OF HISPANIOLA BETWEEN 70W-73W. A SURFACE TROUGH...PREVIOUSLY N PORTION OF A TROPICAL WAVE EXTENDS FROM 22N49W ALONG 18N51W TO 15N51W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 19N-24N BETWEEN 45W-54W. A WEAK 1020 MB HIGH IS IN THE CENTRAL ATLC NEAR 29N57W. A LINGERING COLD FRONT IS IN THE E/CENTRAL ATLC ENTERING THE REGION NEAR 32N22W TO 26N29W WHERE IT DISSIPATES TO 25N38W THEN BECOMES A DISSIPATING STATIONARY FRONT TO 28N49W. CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE WITHIN 75 NM E OF THE FROM E OF 27W AND WITHIN 45 NM NW OF THE FRONT BETWEEN 27W-30W. A WEAK PRESSURE PATTERN WILL PERSIST THROUGH SUN. THE GULF OF MEXICO COLD FRONT IS EXPECTED TO ENTER THE FAR W ATLC SAT THEN SLOW DOWN AS IT BECOMES STATIONARY ACROSS THE NW PORTION INTO MON WHILE A SURFACE TROUGH LINGERS ACROSS THE SW WATERS AND CENTRAL BAHAMAS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW