000 AXNT20 KNHC 191742 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST TUE FEB 19 2013 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1645 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA ENTERING THE TROPICAL ATLC ALONG THE COAST OF SIERRA LEONE AT 8N13W TO 4N21W. THE ITCZ BEGINS AT 4N21W AND CONTINUES TO THE EQUATOR AT 33W TO 2S45W. SCATTERED MODERATE CONVECTION IS FROM 1N-2N BETWEEN 31W-35W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING CONTINUES TO DOMINATE A GOOD PORTION OF THE GULF OF MEXICO EXTENDING FROM A 1030 MB HIGH IN THE WEST ATLC. THIS IS PROVIDING FAIR CONDITIONS ACROSS THE SOUTHERN AND EASTERN GULF. RETURN FLOW OF 10-15 KT IS AROUND THE RIDGE IN THE EASTERN GULF. HOWEVER...AN UPPER LEVEL TROUGH NORTH OF THE AREA ACROSS THE EASTERN CONUS SUPPORTS A COLD FRONT THAT SKIMS THE NORTHERN GULF EXTENDING FROM THE FLORIDA PANHANDLE NEAR 31N86W TO THE SOUTHERN TIP OF TEXAS ALONG 27N93W 26N98W...AS OF 1500 UTC. SCATTERED SHOWER ARE WITHIN 90 NM EAST OF THE AXIS. WINDS INCREASE TO 20 KT AHEAD OF THE FRONT WITH 20 KT WINDS ALSO PRESENT WEST AND NORTH OF THE FRONT AROUND A SURFACE RIDGE BUILDING OVER THE GREAT PLAINS. ALOFT...ZONAL WESTERLY FLOW DOMINATES THE GULF WITH ONLY A MODERATE AREA OF MOISTURE ALOFT NEAR THE FRONT. THE REMAINDER OF THE BASIN IS COVERED BY DRY AIR ALOFT. THE FRONT IS EXPECTED TO CONTINUE MOVING QUICKLY EAST WITH THE WESTERN PORTION STALLING AND DISSIPATING. SHOWERS ARE LIKELY NEAR THE FRONTAL BOUNDARY. CARIBBEAN SEA... MOSTLY FAIR CONDITIONS ARE ACROSS THE CARIBBEAN TODAY DUE TO DRY AIR ALOFT AROUND AN INVERTED UPPER TROUGH WITH AXIS NEAR 78W. STRONG SUBSIDENCE IS ALSO NOTED OVER THE SW CARIBBEAN. A FEW AREAS OF LOW-LEVEL MOISTURE ARE PRESENT AND PRODUCING A FEW ISOLATED SHOWERS DESPITE THE DRY AIR ALOFT. ISOLATED SHOWERS ARE NOTED NORTH OF VENEZUELA FROM 13N-15N BETWEEN 65W-69W. SIMILAR ACTIVITY IS ALSO IN THE NW CARIBBEAN FROM 15N-19N BETWEEN 81W-84W. TRADEWIND FLOW OF 20 KT DOMINATES A LARGE PORTION OF THE BASIN WITH AREAS OF 25 KT WINDS IN THE CENTRAL CARIBBEAN AND NORTH OF COLOMBIA WHERE EVEN 30 KT WINDS ARE POSSIBLE. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... BROAD SURFACE RIDGING COVERS THE WEST ATLC TODAY ANCHORED BY A 1030 MB HIGH CENTERED NEAR 32N69W. THE RIDGE IS PROVIDING FAIR CONDITIONS ACROSS THIS AREA. A BROAD UPPER LEVEL TROUGH COVER THE AREA TO THE NORTH AS WELL AS INTO THE CENTRAL ATLC SUPPORTING A FRONTAL BOUNDARY IN THE CENTRAL ATLC. THE COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N43W AND CONTINUES TO 25N58W WHERE IT BECOMES STATIONARY AND ALSO BEGINS TO DISSIPATE TO 24N68W. ISOLATED SHOWERS ARE ALONG THE AXIS. THE REMAINDER OF THE BASIN IS DOMINATED BY ANOTHER SURFACE RIDGE CENTERED AROUND A 1025 MB HIGH NEAR 27N37W. THE RIDGE IS SUPPORTED BY A STRONG UPPER RIDGE CENTERED NEAR 24N34W. A VERY WEAK SURFACE TROUGH IS EAST OF THE SURFACE HIGH EMBEDDED WITHIN THE RIDGE ALONG 31N26W TO 27N28W. POSSIBLE ISOLATED SHOWERS ARE EAST OF THE TROUGH. THE FRONT IN THE CENTRAL ATLC IS EXPECTED TO CONTINUE MOVING EAST...WHICH WILL CAUSE THE SURFACE HIGH OVER THE EASTERN ATLC TO GRADUALLY DISSIPATE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON