000 AXNT20 KNHC 112358 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED FEB 11 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. ...THE ITCZ... ITCZ IS CENTERED ALONG 6N9W 3N15W 1N23W CROSSING THE EQUATOR NEAR 26W...EXTENDING TO 1S36W AND INTO NE BRAZIL NEAR 2S46W. SCATTERED MODERATE CONVECTION IS S OF 3N BETWEEN 19W-31W. SCATTERED MODERATE CONVECTION IS ALSO S OF 2N BETWEEN 33W-38W. ...DISCUSSION... GULF OF MEXICO... STRONG WESTERLY FLOW ALOFT IS PRESENT ACROSS THE N GULF IN THE BASE OF A VIGOROUS DEEP LAYER TROUGH MOVING EASTWARD ACROSS THE E CONUS. A SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH EXTENDS FROM S MISSISSIPPI NEAR 30N89W TO 27N91W TO 22N97W. INCREASED NORTHERLY WINDS AND A RELATIVELY COOLER AND DRIER AIRMASS ARE PRESENT N OF THIS FRONT. A 1015 MB SURFACE LOW IS PRESENT IN THE SW GULF NEAR 21N97W WITH AN ASSOCIATED SURFACE TROUGH EXTENDING FROM 21N97W TO 19N95W. THE SURFACE LOW AND SURFACE TROUGH ARE BEING ENHANCED BY THE SOUTHWARD FUNNELING OF THIS AIRMASS ACROSS THE W GULF. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE COLD FRONT...WITH ISOLATED THUNDERSTORMS OCCURRING ALONG AND WITHIN 60 NM E OF THE COLD FRONT N OF 28N. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE AFOREMENTIONED VIGOROUS DEEP LAYER TROUGH. AT THE SAME TIME...A SURFACE RIDGE IS PRESENT OVER THE S AND E GULF. SUBSIDENCE ASSOCIATED WITH THIS RIDGE IS COMBINING WITH DRY AIR AND STABLE ATMOSPHERIC CONDITIONS ALOFT TO INHIBIT DEEP CONVECTION ACROSS MUCH OF THE S AND E GULF. CARIBBEAN SEA... GENERALLY FAIR WEATHER IS PRESENT ACROSS THE W CARIBBEAN...WHERE DEEP LAYER DRY AIR AND CONFLUENT WESTERLY FLOW ARE PRESENT. UPPER LEVEL MOISTURE CONTINUES TO BE ADVECTED NORTHEASTWARD INTO THE E CARIBBEAN...WITH SCATTERED SHOWERS E OF 68W. STRONG TRADE WINDS S OF A 1028 MB SURFACE HIGH IN THE W ATLC NEAR 30N65W ARE OCCURRING AND ARE FORECAST TO CONTINUE ACROSS MUCH OF THE CARIBBEAN THROUGH THURSDAY. ATLANTIC OCEAN... SOUTHWESTERLY FLOW ALOFT CONTINUES TO STRENGTHEN ACROSS THE SW NORTH ATLC AS THE VIGOROUS DEEP LAYER TROUGH OVER THE E CONUS MOVES EASTWARD. A SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH IS FORECAST TO ENTER THE SW NORTH ATLC DURING THE NEXT DAY... FOLLOWED BY W TO NW WINDS AND RELATIVELY COOLER AND DRIER CONDITIONS. FARTHER TO THE E...DEEP LAYER DRY AIR AND SUBSIDENCE ARE PRESENT IN THE VICINITY OF A 1028 MB SURFACE HIGH NEAR 30N65W. TO THE E...A DEEP LAYER TROUGH IS PRESENT WITH AN ASSOCIATED SURFACE COLD FRONT EXTENDING FROM 23N51W TO 28N40W TO 32N34W TO N OF THE DISCUSSION AREA. THIS COLD FRONT IS DISSIPATING W OF 35W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 30 NM EITHER SIDE OF THIS COLD FRONT. ALSO...UPPER LEVEL DIVERGENCE IN THE NE QUADRANT OF AN UPPER LEVEL JET MAXIMUM SE OF THE COLD FRONT IS SUPPORTING SCATTERED SHOWERS N OF 24N BETWEEN 32W-38W. THIS ACTIVITY IS BEING ENHANCED BY LOW LEVEL CONVERGENCE IN THE VICINITY OF A SURFACE TROUGH EXTENDING FROM 25N40W TO 23N44W TO 21N46W. FARTHER E... FAIR WEATHER CONDITIONS ARE OCCURRING ACROSS MUCH OF THE E ATLC...WHERE SUBSIDENCE ASSOCIATED WITH A SURFACE RIDGE IS PRESENT. ACROSS THE TROPICAL ATLC...AN UPPER HIGH IS PRESENT NEAR 6N46W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS HIGH IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ. $$ COHEN