000 AXNT20 KNHC 142352 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON SEP 14 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 65W S OF 15N MOVING W NEAR 10 KT. THIS WAVE IS LOW-AMPLITUDE AND IS MOSTLY INLAND OVER CENTRAL VENEZUELA. HOWEVER...THE LOW-LEVEL CLOUD FIELD ACROSS THE SE CARIBBEAN EXHIBITS CYCLONIC TURNING ALONG THE WAVE AXIS S OF 14N. THE WAVE CONTINUES MOVING BENEATH A VERY DRY AND STABLE ATMOSPHERE ALOFT OVER THE CARIBBEAN SEA WATERS...THEREFORE NO SIGNIFICANT CONVECTION OR SHOWERS ACCOMPANY THE WAVE N OF 11N. SCATTERED MODERATE CONVECTION IS S OF 11N BETWEEN 62W-68W...REMAINING MOSTLY OVER INLAND VENEZUELA. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 10N22W AND DISCONTINUOUS TO 11N30W THEN CONTINUOUS ALONG 9N42W 9N61W. WIDELY SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE W AFRICA COAST FROM 8N-18N BETWEEN 13W-20W. ELSEWHERE...SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE WITHIN 200 NM EITHER SIDE OF A LINE FROM 6N22W TO 8N44W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS LOCATED ACROSS THE CENTRAL AND SRN PLAINS OF THE CONUS AND CONTINUES TO SUPPORT A 1008 MB LOW CENTERED OVER ERN TEXAS NEAR 32N94W. ELSEWHERE OVER THE GULF IN THE UPPER LEVELS...MOSTLY WESTERLY NEAR ZONAL FLOW IS PRESENT. A SERIES OF FAST MOVING FRONTAL WAVES ARE ROTATING AROUND THE MIDDLE TO UPPER LEVEL LOW WITH A DISSIPATING COLD FRONT EXTENDING INTO THE GULF NEAR VERMILION BAY LOUISIANA TO 25N94W THEN AS A DISSIPATING STATIONARY FRONT TO 22N97W. SCATTERED SHOWERS AND A FEW ISOLATED TSTMS ARE WITHIN 60 NM OF THE FRONT ACROSS THE WRN GULF. FARTHER TO THE E OVER THE N/CENTRAL GULF...A SURFACE TROUGH IS ANALYZED FROM PENSACOLA FLORIDA TO 25N90W. THIS SURFACE BOUNDARY ALONG WITH A LARGE AREA OF UPPER LEVEL DIFFLUENCE E OF 90W...ARE GENERATING SCATTERED SHOWERS AND TSTMS N OF 27N BETWEEN 83W-87W...INCLUDING PORTIONS OF THE FLORIDA PANHANDLE AND WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH. A DISSIPATING STATIONARY FRONT IS ALONG THE WRN FLORIDA PANHANDLE FROM POMPANO BEACH TO TAMPA BAY AND OVER THE FLORIDA PANHANDLE. THIS BOUNDARY IS SUPPORTING A FEW SCATTERED SHOWERS AND ISOLATED TSTMS MAINLY INLAND OVER THE WRN FLORIDA PENINSULA THIS EVENING. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED IN THE YUCATAN CHANNEL AND EXTENDS UPPER LEVEL RIDGING ACROSS CARIBBEAN W OF 68W. THIS ANTICYCLONIC FLOW SUPPORTS A 1016 MB HIGH LOCATED S OF WRN CUBA NEAR 21N81W. MOSTLY FAIR SKIES ARE LOCATED ACROSS THE NW CARIBBEAN...HOWEVER UPPER LEVEL DIFFLUENCE AND DAYTIME INSTABILITY ARE SUPPORTING SCATTERED SHOWERS AND TSTMS ACROSS CUBA AND THE NEARBY COASTAL WATERS WITHIN 60 NM. AN UPPER LEVEL LOW IS CENTERED OVER THE VIRGIN ISLANDS AND COVERS THE ERN CARIBBEAN E OF 68W. MOIST SWLY UPPER LEVEL DIFFLUENT FLOW IS SUPPORTING SCATTERED SHOWERS E OF 63W...INCLUDING MOST OF THE LESSER ANTILLES. ELSEWHERE ACROSS THE SW CARIBBEAN...SCATTERED SHOWERS ARE OCCURRING S OF 10N BETWEEN COLOMBIA AND COSTA RICA DUE TO THE CLOSE PROXIMITY OF THE ITCZ AXIS. ATLANTIC OCEAN... A COLD FRONT EXTENDS FROM THE CENTRAL ATLC THROUGH 32N67W TO A 1011 MB LOW IN THE W ATLC NEAR 28N74W CONTINUING SW TO NEAR POMPANO BEACH FLORIDA. THIS FRONTAL SYSTEM AND LOW IS SUPPORTED ALOFT BY UPPER LEVEL TROUGHING PRESENT OVER MUCH OF THE WRN ATLC N OF 30N. THE UPPER LEVEL ANTICYCLONIC CIRCULATION ANCHORED OVER THE YUCATAN CHANNEL EXTENDS UPPER LEVEL RIDGING OVER THE W ATLC W OF 66W NARROWING ALONG 27N64W TO 29N59W. LOW-LEVEL CONVERGENCE ALONG AND E OF THE FRONTAL BOUNDARY COUPLED WITH DIFFLUENCE ALOFT ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 300 NM SE OF THE FRONTAL BOUNDARY. AN UPPER LOW IS CENTERED OVER THE VIRGIN ISLANDS NEAR 18N64W COVERING THE ERN CARIBBEAN. MOIST SWLY UPPER LEVEL DIFFLUENT FLOW IS GENERATING A LARGE AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS E OF THE UPPER TROUGH FROM 10N-20N BETWEEN 55W-61W. FARTHER TO THE EAST...THE REMNANTS OF FRED...A 1012 MB LOW...IS CENTERED NEAR 19N40W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION LOCATED NW OF THE LOW FROM 18N-22N BETWEEN 41W-43W. FARTHER TO THE SE NEAR THE CAPE VERDE ISLANDS...A DISCONTINUOUS AREA OF THE ITCZ CONTAINS A 1012 MB LOW CENTERED NEAR 14N25W AND IS GENERATING SCATTERED MODERATE CONVECTION FROM 14N-16N BETWEEN 25W-30W. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE ON AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 20N17W THAT COVERS THE ERN ATLC FROM 10N-32N E OF 38W. ELSEWHERE ACROSS THE ATLC BASIN...SURFACE RIDGING DOMINATES N OF 25N E OF 50W. $$ HUFFMAN