000 AXNT20 KNHC 071746 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU MAR 07 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 FROM THE COAST OF GUINEA NEAR 10N14W TO 4N20W. THE ITCZ BEGINS AT 4N20W AND CONTINUES ALONG 1N26W 3N36W EQ49W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-5N BETWEEN 11W-18W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM EQ-4N BETWEEN 21W-38W. SIMILAR ACTIVITY IS FROM EQ-2N BETWEEN 45W-52W. ...DISCUSSION... GULF OF MEXICO... A COLD AND DRY AIRMASS LIES ACROSS THE GULF OF MEXICO TODAY IN THE WAKE OF A COLD FRONT THAT MOVED THROUGH THE AREA LAST NIGHT. SURFACE RIDGING HAS BUILT IN BEHIND THE FRONT WITH A 1030 MB HIGH CENTERED OVER WESTERN KENTUCKY. THIS PATTERN IS PROVIDING ANTI-CYCLONIC FLOW ACROSS THE BASIN WITH SPEEDS RANGING FROM 10-15 KT. THE RIDGE IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE MOVING OVER THE AREA AND MUCH OF THE CENTRAL CONUS. WATER VAPOR IMAGERY ALSO INDICATES THERE IS A LOT OF DRY AIR ALOFT...WHICH IS HELPING MAINTAIN MOSTLY CLEAR SKIES BESIDES SOME STRATO-CUMULUS CLOUDS ACROSS THE EASTERN GULF. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. RETURN FLOW WILL INCREASE OVER THE WEEKEND BEFORE THE NEXT COLD FRONT REACHES THE AREA EARLY MONDAY. CARIBBEAN SEA... FAIR CONDITIONS SPREAD ACROSS A LARGE PORTION OF THE CARIBBEAN TODAY DUE TO MOSTLY DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE BASIN CENTERED NEAR 10N57W. AN AREA OF LOW-LEVEL MOISTURE IS PRESENT FROM JAMAICA TO THE COASTS OF NICARAGUA AND COSTA RICA WHERE LOW-LEVEL CLOUDS AND POSSIBLE ISOLATED SHOWERS ARE PRESENT. A FEW POSSIBLE ISOLATED SHOWERS ARE ALSO IN THE NE CORNER OF THE CARIBBEAN DUE TO A DISSIPATING COLD FRONT EXTENDING FROM CENTRAL CUBA TO THE YUCATAN PENINSULA ALONG 21N77W 20N86W...AS OF 1500 UTC. TRADEWIND FLOW OF 15-20 KT IS PRESENT THROUGHOUT THE CENTRAL AND EASTERN PORTIONS OF THE BASIN. THE FRONT IN THE NORTHEAST CORNER WILL CONTINUES TO DISSIPATE WITH LITTLE CHANGE EXPECTED ELSEWHERE. ATLANTIC OCEAN... A STRONG LOW PRESSURE SYSTEM COVERS THE WEST ATLC SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N62W AND CONTINUES TO CENTRAL CUBA ALONG 25N69W 21N77W. ISOLATED SHOWERS ARE ALONG THE AXIS WITH STRATO-CUMULUS CLOUDS SPREADING WESTWARD TO THE UNITED STATES COAST. STRONG WINDS ALL ALSO WEST OF THE FRONT REACHING GALE FORCE NORTH OF 29N BOTH EAST AND WEST OF THE AXIS. ALOFT...AN UPPER LEVEL LOW NEAR 37N67N SUPPORTS THE SURFACE LOW. BROAD UPPER RIDGING COVERS THE AREA TO THE SOUTH AND THE CENTRAL ATLC AS WELL. THE UPPER RIDGE SUPPORTS A 1019 MB HIGH NEAR 27N52W...WHICH IS PROVIDING FAIR CONDITIONS ACROSS THE CENTRAL ATLC. A SECOND UPPER LOW NEAR 46N32W SUPPORTS ANOTHER COLD FRONT THAT ENTERS THE AREA NEAR 32N18W AND CONTINUES TO 21N44W. POSSIBLE ISOLATED SHOWERS ARE UP TO 120 NM EAST OF THE AXIS. A SURFACE TROUGH...A DISSIPATED PORTION OF THE FRONT...IS JUST NORTHEAST OF THE LEEWARD ISLANDS ALONG 21N57W 19N63W SUPPORTING ISOLATED SHOWERS WITHIN 100 NM TO EITHER SIDE. THE REMAINDER OF THE EAST ATLC IS COVERED BY WEAK SURFACE RIDGING AROUND A 1021 MB HIGH NEAR 23N20W. THE RIDGE IS SUPPORTED BY A BROAD UPPER RIDGE ALONG 13W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON