000 AXNT20 KNHC 231749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON JAN 23 2012 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 1700 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE SRN COAST OF LIBERIA NEAR 5N9W TO 7N16W. THE ITCZ CONTINUES FROM 7N16W ALONG 3N25W 2N37W CROSSING THE EQUATOR AT 48W TO 1S50W. SCATTERED MODERATE/STRONG CONVECTION IS S OF THE MONSOON AXIS FROM EQ-3N BETWEEN 3W-13W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM OF THE AXIS BETWEEN 25W-30W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 1S-4N BETWEEN 39W-52W. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER LEVEL TROUGH WHICH IS RAPIDLY MOVING OVER THE GREAT LAKES REGION SUPPORTS A COLD FRONT MOVING ACROSS THE ERN CONUS WHICH ENTERS THE GULF OF MEXICO OVER SE LOUISIANA NEAR 29N91W. THE FRONT CONTINUES TO THE SRN TIP OF TEXAS NEAR 26N97W TO 25N100W...AS OF 1500 UTC. ISOLATED SHOWERS ARE ALONG THE FRONT AXIS WITH STRONGER ACTIVITY FARTHER INLAND. THE REMAINDER OF THE BASIN IS IMPACTED BY A SURFACE RIDGE EXTENDING FROM THE W ATLC. DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE OVER THE CARIBBEAN...GULF AND W ATLC IS HELPING SUPPORT THE SURFACE RIDGE AND MAINTAIN FAIR SURFACE CONDITIONS. BESIDES NEAR THE FRONT...SKIES ARE MOSTLY CLEAR WITH ANTI-CYCLONIC FLOW OF 10-15 KTS. THE FRONT IS EXPECTED TO CONTINUE TO MOVE SE ACROSS THE BASIN THROUGH TONIGHT BEFORE STALLING AND RETREATING BACK TO THE NW. ANOTHER FRONT IS EXPECTED TO MOVE INTO THE BASIN LATER IN THE WEEK. THE CARIBBEAN SEA... MOSTLY FAIR CONDITIONS ARE ACROSS THE CARIBBEAN TODAY DUE TO SIGNIFICANT DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE WRN HALF OF THE BASIN. AN UPPER LEVEL TROUGH DIGS INTO THE ERN CARIBBEAN ALONG 67W...BUT IS ACCOMPANIED BY DRY AIR. TRADEWIND FLOW OF 15-20 KTS IS ACROSS MUCH OF THE BASIN. A FEW PATCHES OF CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE EMBEDDED WITHIN THE FLOW. A SHEAR AXIS...REMNANTS OF A FRONTAL BOUNDARY IN THE CENTRAL ATLC...EXTENDS ACROSS THE FAR SE CORNER FROM 11N62W TO 12N67W SUPPORTING AN AREA OF MORE CONCENTRATED SHOWERS. EXPECT THE SHEAR AXIS TO DISSIPATE WHILE THE REMAINDER OF THE BASIN REMAINS UNDER SIMILAR CONDITIONS. THE ATLANTIC OCEAN... AN UPPER LEVEL RIDGE COVERS THE FAR WRN ATLC ALONG 75W PROVIDING FAIR WEATHER ACROSS FLORIDA AND MUCH OF THE BAHAMAS. A SHORTWAVE UPPER LEVEL TROUGH TO THE E ALONG 65W SUPPORTS A SURFACE TROUGH ALONG 29N69W TO 22N73W. A FEW CLUSTERS OF SHOWERS/THUNDERSTORMS ARE NEAR THE AXIS WITH UPPER LEVEL CLOUDINESS TO THE E AROUND THE E SIDE OF THE UPPER TROUGH. WEAK SURFACE RIDGING COVERS THE REMAINDER OF THE W ATLC AROUND A 1026 MB HIGH NEAR 32N62W. A NARROW UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLC ALONG 44W SUPPORTING A DISSIPATING STATIONARY FRONT ALONG 32N41W 21N41W 14N47W. A SHEAR AXIS CONTINUES FROM THE TAIL END OF THE FRONT TO JUST N OF VENEZUELA NEAR 11N61W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE WITHIN 200 NM E OF THE AXIS TO THE N OF 27N. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE THE AXIS ELSEWHERE ALONG THE FRONT AND THE SHEAR AXIS. A SURFACE TROUGH IS W OF THE FRONT ALONG 32N45W 26N45W 22N49W WITH NO ASSOCIATED SHOWER ACTIVITY. THE REMAINDER OF THE E ATLC IS DOMINATED BY SURFACE RIDGING ANCHORED BY A 1031 MB HIGH NEAR 36N27W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE ALONG 28W. EXPECT THE FRONTAL BOUNDARY IN THE CENTRAL ATLC TO CONTINUE TO DISSIPATE STILL LEAVING BEHIND SOME LOWER PRESSURES AND TROUGHING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON