000 AXNT20 KNHC 130548 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN SEP 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 0345 UTC. ...TROPICAL WAVES... THE TROPICAL WAVE THAT WAS ALONG 22W HAS NOT PROGRESSED WESTWARD OVER THE PAST 24 HOURS. HOWEVER THE 1012 MB LOW REMAINS NEAR 12N22W AND IS MENTIONED IN THE MIATWOAT AS HAVING A LOW PROBABILITY OF FORMING A TROPICAL SYSTEM. THEREFORE THE TROPICAL WAVE PORTION WILL BE DROPPED ON THE 0600 UTC ANALYSIS. SCATTERED STRONG CONVECTION IS FROM 12N-14N BETWEEN 21W-24W. TROPICAL WAVE IS ALONG 89W S OF 19N MOVING W NEAR 15 KT. WAVE IS INLAND OVER THE YUCATAN PENINSULA AND INTO THE E PACIFIC REGION. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 15N15W 12N28W 9N40W 12N52W 10N62W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE OVER THE CAPE VERDE ISLANDS FROM 15N-19N BETWEEN 22W-26W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 75 NM OF ITCZ FROM 34W-40W. ...DISCUSSION... GULF OF MEXICO... A NEAR STATIONARY BOUNDARY EXTENDS ACROSS THE N GULF FROM A 1011 MB LOW OFF THE NE COAST OF FLORIDA THROUGH APALACHICOLA FLORIDA THEN JUST S OF NEW ORLEANS LOUISIANA SW TO A 1004 MB LOW NEAR 27N96W WITH A SURFACE TROUGH EXTENDING S TO 23N96W. A SURFACE TROUGH IS FROM 24N86W ACROSS S FLORIDA NEAR NAPLES TO PALM BEACH. A STRONG UPPER LOW IS INLAND OVER E TEXAS WITH THE UPPER TROUGH EXTENDING S TO 20N COVERING THE GULF W OF 91W WHILE AN UPPER RIDGE EXTENDS FROM THE NE YUCATAN PENINSULA TO ACROSS S FLORIDA INTO THE W ATLC. THIS SCENARIO COUPLED WITH THE ABUNDANCE OF DEEP LAYER MOISTURE IS GENERATING SCATTERED/HEAVY SHOWERS WITH SCATTERED/NUMEROUS THUNDERSTORMS ACROSS THE SE GULF WITHIN 120 NM S OF THE SURFACE TROUGH E OF 86W TO OVER S FLORIDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE NE GULF N OF THE SURFACE TROUGH E OF 86W TO INLAND OVER FLORIDA. ISOLATED SHOWERS/THUNDERSTORMS DOT THE NW GULF N OF 26N W OF 90W. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE W CARIBBEAN N OF 13N W OF 74W WHILE AN UPPER TROUGH COVERS THE NE CARIBBEAN EXTENDING FROM AN UPPER LOW N OF THE VIRGIN ISLANDS. EVEN THOUGH THERE IS DIFFLUENCE ALOFT...THE SURFACE REMAINS DRY OVER THE W CARIBBEAN LEAVING ISOLATED SHOWERS/THUNDERSTORMS INLAND AND ALONG THE IMMEDIATE COASTAL WATERS OF CUBA AND HAITI. THE ITCZ EXTENDS FROM COLOMBIA ACROSS PANAMA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N TO INLAND OVER COLOMBIA AND PANAMA FROM 74W-82W. AN UPPER RIDGE EXTENDING ACROSS VENEZUELA FROM THE W TROPICAL ATLC IS GIVING THE SE CARIBBEAN DENSE CIRRUS CLOUDS BUT NO SHOWER ACTIVITY. OTHERWISE THE REMAINDER OF THE CARIBBEAN IS REMARKABLY CLEAR AGAIN TONIGHT. ATLANTIC OCEAN... A 1011 MB LOW IS JUST OFF THE NE FLORIDA COAST NEAR 31N80W WITH A STATIONARY BOUNDARY EXTENDING W INTO THE GULF OF MEXICO. THE UPPER RIDGE FROM THE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF 70W PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 27N W OF 75W. AN UPPER LOW IS N OF VIRGIN ISLANDS NEAR 21N65W WITH THE UPPER TROUGH DIPPING S OVER THE NE CARIBBEAN. A BROAD UPPER TROUGH COVERS THE CENTRAL ATLC N OF 15N BETWEEN 35W-54W WITH THE ASSOCIATED FRONTAL BOUNDARY ENTERING THE REGION NEAR 32N37W EXTENDING SW ALONG 29N42W W 30N48W SW TO 28N52W THEN NW TO BEYOND 32N58W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM EITHER SIDE OF THE ENTIRE FRONTAL BOUNDARY. A REMNANT SURFACE TROUGH REMAINS IN THE TROPICAL ATLC EXTENDING FROM 18N52W TO 11N54W WITH NO SIGNIFICANT WEATHER. A BROAD UPPER RIDGE COVERS THE E ATLC FROM THE TROPICS TO 30N ANCHORED NEAR 19N21W AND PROVIDING THE SLY SHEAR OVER A 1006 MB LOW...THE REMNANTS OF FRED...CENTERED NEAR 17N34W AND ENHANCING THE CONVECTION OVER THE CAPE VERDE ISLANDS. $$ WALLACE