000 AXNT20 KNHC 060003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI OCT 05 2012 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY VALID THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS APPROACHING THE CAPE VERDE ISLANDS ALONG 16N18W 10N23W MOVING WEST AT 10-15 KT. THE WAVE ALIGNS WITH A LOW-AMPLITUDE SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-11N BETWEEN 22W-29W. A TROPICAL WAVE IS MOVING THROUGH THE LESSER ANTILLES ALONG 21N58W TO 11N62W MOVING WEST AT 5-10 KT. THE WAVE LIES UNDERNEATH THE BASE OF AN UPPER LEVEL LOW CENTERED NE OF THE NORTHERN LEEWARD ISLANDS...WHICH IS HELPING ENHANCE CONVECTION EAST OF THE ISLANDS. THE WAVE WILL LIKELY LOSE SOME OF ITS ENERGY TO THE UPPER LOW. SCATTERED MODERATE CONVECTION IS FROM 14N-19N BETWEEN 54W-57W. SIMILAR ACTIVITY IS FROM 19N-22N BETWEEN 57W-60W. A TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 17N72W TO 8N73W MOVING W NEAR 15 KT. HIGH MOISTURE VALUES COVER THE SOUTHERN CARIBBEAN IN THE VICINITY OF THE WAVE...BUT THE AXIS IS BECOMING MORE DIFFICULT TO DETERMINE. CURRENTLY NUMEROUS STRONG CONVECTION IS OVER NORTHERN COLOMBIA FROM 9N-12N BETWEEN 72W-74W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA AT 10N15W ALONG 8N23W 11N34W 9N40W. THE ITCZ BEGINS AT 9N40W ALONG 9N48W 15N53W. A LARGE CLUSTER OF MODERATE/STRONG CONVECTION IS ABOUT TO MOVE OFF THE COAST OF GUINEA. SCATTERED MODERATE/STRONG CONVECTION IS ALSO FROM 8N-9N BETWEEN 32W-34W. SCATTERED MODERATE CONVECTION IS FROM 7N-9N BETWEEN 43W-46W. ...DISCUSSION... THE GULF OF MEXICO... MOIST CONDITIONS CONTINUE TO COVER THE GULF OF MEXICO FROM THE SW GULF TO THE NE GULF INCLUDING MUCH OF THE YUCATAN PENINSULA AND THE FLORIDA PENINSULA. AN UPPER LEVEL TROUGH SITS OVER THE WESTERN GULF PROVIDING MOIST DIFFLUENT FLOW ACROSS THE CENTRAL AND EASTERN GULF...WHILE DRY AIR AND SUBSIDENCE ARE KEEPING THE NW GULF UNDER FAIR WEATHER AND CLEAR SKIES. AS OF 2100 UTC...THE UPPER TROUGH SUPPORTS A SURFACE TROUGH IN THE SW GULF FROM 24N91W TO 19N90W WITH SCATTERED SHOWERS EXTENDING 150 NM IN EITHER DIRECTION OF THE AXIS. A SECOND SURFACE TROUGH IS IN THE NE CORNER ALONG 30N85W TO 27N87W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE 150 NM TO EITHER SIDE OF THE AXIS WITH WIDESPREAD SHOWERS/THUNDERSTORMS EXTENDING DOWN MUCH OF THE WESTERN HALF OF THE FLORIDA PENINSULA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... UPPER LEVEL MOISTURE IS BEING DRAWN AROUND AN UPPER LEVEL RIDGE COVERING THE NW CARIBBEAN HELPING SUPPORT A FEW WIDELY ISOLATED SHOWERS/THUNDERSTORMS OVER THE NW CARIBBEAN AND PORTIONS OF CUBA...JAMAICA...AND CENTRAL AMERICA. A TROPICAL WAVE IN THE CENTRAL CARIBBEAN IS HELPING SUPPORT STRONG SHOWERS/THUNDERSTORMS OVER NORTHERN COLOMBIA. SCATTERED SHOWERS ALSO COVERS THE SW CARIBBEAN S OF 12N INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS THROUGH COSTA RICA AND PANAMA TO NORTHERN COLOMBIA. THIS ACTIVITY IS ALSO ENHANCED BY DIFFLUENCE ALOFT AROUND THE BASE OF AN UPPER LEVEL TROUGH EXTENDING FROM EASTERN CUBA TO NICARAGUA. WEAK UPPER RIDGING ALONG WITH DRY AIR ALOFT COVER THE EASTERN CARIBBEAN PROVIDING MOSTLY FAIR CONDITIONS. HOWEVER...A TROPICAL WAVE IS JUST MOVING INTO THE BASIN AND COULD SUPPORT A FEW SHOWERS/THUNDERSTORMS OVER THE LESSER ANTILLES. RIGHT NOW...MOST OF THE ACTIVITY ASSOCIATED WITH THE WAVE IS WELL TO THE EAST. STRONG SHOWERS/THUNDERSTORMS ARE INLAND OVER VENEZUELA THOUGH. EXPECT BOTH WAVES TO CONTINUE WESTWARD WITH CONTINUED SHOWER ACTIVITY ACROSS THE SOUTHERN CARIBBEAN AND INCREASING IN THE EASTERN CARIBBEAN. THE ATLANTIC OCEAN... A FEW SHOWERS/THUNDERSTORMS EXTEND OFF THE EAST COAST OF FLORIDA ASSOCIATED WITH DIFFLUENCE ALOFT AROUND AN UPPER LEVEL TROUGH OVER THE WESTERN GULF OF MEXICO. THE REMAINDER OF THE W ATLC IS UNDER WEAK SURFACE RIDGING EXTENDING FROM GEORGIA AND SUPPORTED BY AN UPPER LEVEL RIDGE COVERING THE WESTERN ATLC. A SURFACE TROUGH ALONG 27N58W TO 25N65W IS SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 23N-26N BETWEEN 65W-69W...AND WITHIN 30 NM EITHER SIDE OF THE TROUGH AXIS. AN UPPER LEVEL LOW TO THE SE NEAR 20N60W IS ENHANCING CONVECTION NEAR A TROPICAL WAVE MOVING THROUGH THE LESSER ANTILLES. SEE SPECIAL FEATURES ABOVE. AN UPPER LEVEL TROUGH ALONG 35W SUPPORTS A COLD FRONT THAT EXTENDS INTO THE AREA NEAR 32N34W ALONG 26N44W 27N55W 30N62W. SCATTERED SHOWERS EXTEND 80 NM S OF THE AXIS. A LARGE AREA OF STRONG CONVECTION IS EAST OF THE FRONT N OF 27N BETWEEN 28W-32W. THIS IS LIKELY DUE TO WIND SPEED CONVERGENCE FROM GALE FORCE WINDS EAST OF THE FRONT NEAR 30N ALONG WITH DIFFLUENCE ALOFT AROUND THE UPPER TROUGH. A SURFACE TROUGH IS ALSO AHEAD OF THE FRONT ALONG 26N37W TO 21N38W. THIS TROUGH IS THE REMNANTS OF OSCAR WHICH DISSIPATED EARLIER TODAY. AN AREA OF SCATTERED SHOWERS IS EAST OF THE TROUGH FROM 24N-26N BETWEEN 32W-33W ALSO LIKELY DUE TO WIND SPEED CONVERGENCE FROM GALE FORCE WINDS EAST OF THE TROUGH AXIS NEAR 24N34W. AN UPPER LEVEL RIDGE COVERS THE FAR EASTERN ATLC SUPPORTING A WEAK SURFACE RIDGE...WHICH IS PROVIDING FAIR CONDITIONS ACROSS THE FAR EASTERN ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON