000 AXNT20 KNHC 130549 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST FRI NOV 13 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N15W 9N20W 7N22W 8N36W 8N38W 4N53W. A SURFACE TROUGH IS ALONG 21W FROM 5N-10N WITH SCATTERED MODERATE CONVECTION FROM 5N-10N BETWEEN 21W-26W. ANOTHER SURFACE TROUGH IS ANALYZED FROM 13N31W TO 10N36W TO 7N37W WITH SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION FROM 3N-12N BETWEEN 30W-40W. ELSEWHERE...SCATTERED MODERATE CONVECTION IS FROM 4N-10N BETWEEN 12W-16W. SIMILAR CONVECTION IS FROM 6N-9N BETWEEN 46W-55W. ...DISCUSSION... GULF OF MEXICO... MAINLY NLY SURFACE FLOW PREVAILS ACROSS THE GULF OF MEXICO E OF 94W AS A SURFACE RIDGE BUILDS IN ACROSS THE WESTERN GULF WATERS. ALOFT...AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS FROM THE FLORIDA PENINSULA THROUGH 25N90W TO OVER CENTRAL MEXICO. SIGNIFICANT DRY AIR AND SUBSIDENCE IS NOTED ON WATER VAPOR IMAGERY ACROSS THE GULF THIS EVENING PROVIDING GENERALLY STABLE CONDITIONS AND FAIR SKIES. AS THE SURFACE RIDGE DRIFTS EASTWARD...WINDS WILL REMAIN LIGHT WITH SELY RETURN FLOW EXPECTED TO DEVELOP ACROSS THE WESTERN WATERS SATURDAY EAST OF A COLD FRONT FORECAST TO MOVE OFF THE TEXAS COAST MONDAY. CARIBBEAN SEA... A COLD FRONT EXTENDS ACROSS CENTRAL CUBA AND INTO THE NW CARIBBEAN NEAR 22N80W EXTENDING SW TO NORTHERN BELIZE NEAR 18N88W. NO SHOWER ACTIVITY IS CURRENTLY ASSOCIATED WITH THIS FRONT. A SURFACE TROUGH HOWEVER IS ANALYZED SE OF THE COLD FRONT AND EXTENDS INTO THE WESTERN CARIBBEAN NEAR 20N77W CONTINUING ALONG 17N80W TO 12N82W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. MORE CONCENTRATED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE SW CARIBBEAN...SOUTHERN NICARAGUA...AND COSTA RICA FROM 8N-13N BETWEEN 80W-86W. THIS ACTIVITY NEAR THE TAIL END OF THE SURFACE TROUGH IS ENHANCED BY UPPER LEVEL DIFFLUENCE DUE TO AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 11N82W. THE UPPER LEVEL RIDGE EXTENDS ACROSS THE BASIN EASTWARD TO 60W. A FEW ISOLATED LOW-LEVEL SHOWERS ARE OCCURRING N OF 16N BETWEEN 61W-71W. ATLANTIC OCEAN... A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N73W AND EXTENDS S-SW ALONG 30N73W TO THE CENTRAL BAHAMAS NEAR 24N77W TO CENTRAL CUBA AND INTO THE NW CARIBBEAN. POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. E OF THE FRONT A SURFACE TROUGH IS ANALYZED FROM 32N70W TO 25N73W AND OVER EASTERN CUBA. SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 25N BETWEEN 66W-72W. THIS FRONT IS BEING DRIVEN BY AN UPPER LEVEL LOW CENTERED OFF THE NORTH CAROLINA COAST NEAR 34N77W AND UPPER LEVEL TROUGHING DIPPING TO 27N W OF 70W. UPPER LEVEL DIFFLUENCE E OF THE UPPER TROUGH AXIS IS ALSO AIDING IN ENHANCING THE CONVECTION. FARTHER E...A 1004 MB LOW IS CENTERED NEAR 33N65W. LOW-LEVEL CONVERGENCE EAST OF THE LOW CENTER FOCUSED ON A STATIONARY FRONT EXTENDING FROM THE LOW TO 31N58W IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 30N BETWEEN 50W-60W. THIS CONVECTION IS BEING ENHANCED BY A LARGE AREA OF UPPER LEVEL DIFFLUENCE ACROSS THE WESTERN ATLC AND INTO THE CENTRAL ATLC N OF 24N BETWEEN 50W-70W. OVER THE CENTRAL ATLC...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N42W AND EXTENDS WESTWARD ALONG 32N TO 55W. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...A BROAD SURFACE RIDGE DOMINATES ANCHORED BY A 1018 MB HIGH CENTERED NEAR 27N27W. THIS SURFACE HIGH IS SUPPORTED BY AN UPPER LEVEL RIDGE WITH AXIS ALONG 43W. EAST OF THE UPPER LEVEL RIDGE...AN UPPER LEVEL TROUGH AXIS DIPS TO 13N E OF 30W AND CONTINUES SHEARING MOISTURE FROM THE ITCZ TO THE NE SUPPORTING SCATTERED SHOWERS FROM 12N-21N E OF 27W. $$ HUFFMAN