000 AXNT20 KNHC 130001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAR 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE GUINEA COAST IN AFRICA NEAR 10N14W TO 06N17W TO 04N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N19W THEN ALONG 1N21W 1S30W TO THE NORTHERN COAST OF BRAZIL NEAR 2S40W. SCATTERED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 10W-20W AS WELL AS FROM 02S-04N BETWEEN 20W- 29W. ...DISCUSSION... GULF OF MEXICO... A BROAD MIDDLE TO UPPER LEVEL LONGWAVE TROUGH EXTENDS FROM CENTRAL USA TO THE EASTERN CONUS SUPPORTING A COLD FRONT THAT AS OF 21 UTC ENTERS THE GULF BY FORT MYERS FLORIDA AND EXTENDS ALONG 24N83W 21N85W THEN ALONG THE EASTERN COAST OF THE YUCATAN PENINSULA TO 16N87W. MOSAIC DOPPLER RADAR IMAGERY INDICATE WIDELY SCATTERED SHOWERS OCCURRING IN THE STRAITS OF FLORIDA. METAR OBSERVATIONS OVER WESTERN CUBA AND PENINSULA OF YUCATAN INDICATE THAT RAINSHOWERS ARE OCCURRING IN THE YUCATAN CHANNEL. NORTH-NORTHEASTERLY WIND FLOW SPREADS W OF 85W AND NORTHWESTERLY WIND COVERS THE REMAINDER OF THE GULF WEST OF THE COLD FRONT. IN TERMS OF WIND MAGNITUDE 5-10 KT WINDS SPREAD W OF 91W WHEREAS 15 KT WINDS DOMINATE W OF THAT MERIDIAN. THE FRONT IS EXPECTED TO WEAKEN AND SWEEP EAST OF THE BASIN WITHIN 24 HOURS WHILE NORTHEASTERLY WINDS WILL BE DOMINATING THE ENTIRE BASIN. CARIBBEAN SEA... AS OF 21 UTC...A PORTION OF THE COLD FRONT OVER THE EASTERN GULF EXTENDS ALONG THE YUCATAN CHANNEL FROM 21N85W TO 20N86W AND CONTINUES ALONG THE COASTAL WATERS OF THE EASTERN YUCATAN PENINSULA TO 16N87W. ALSO NEAR THE COASTAL WATERS OF THE EASTERN YUCATAN PENINSULA...A PREFRONTAL TROUGH EXTENDS FROM 20N86W TO 16N86W. METAR OBSERVATIONS OVER WESTERN CUBA AND THE YUCATAN PENINSULA INDICATE SHOWERS ARE OCURRING ALONG THE FRONTAL BOUNDARY AND COULD BE EXTENDING APPROXIMATELY 100 NM EAST OF THE FRONT. IN THE MIDDLE TO UPPER LEVELS WESTERLY FLOW IS ACROSS THE ENTIRE BASIN. WATER VAPOR IMAGERY INDICATE GENERALLY DRY AND STABLE AIR ALOFT FOR THE REMAINDER OF THE CARIBBEAN WHICH IS FAVORING FAIR WEATHER CONDITIONS. E-NE TRADEWINDS IN THE RANGE OF 15-20 KT SPREAD OVER THE EASTERN...CENTRAL AND SOUTHERN CARIBBEAN WHILE LIGHTER SOUTHEASTERLY WINDS DOMINATE THE WESTERN CARIBBEAN AHEAD OF THE FRONT. OVER THE COURSE OF 24 HOURS...THE FRONT WILL CONTINUE TO MOVE SLOWLY OVER THE NW CARIBBEAN WHILE IT WEAKENS. RAINSHOWERS WILL CONTINUE OVER THE NW CARIBBEAN AND EASTERLY TRADEWINDS OVER THE REST OF THE BASIN. ATLANTIC OCEAN... BROKEN TO OVERCAST SKIES ALONG WITH SCATTERED SHOWERS COVER THE WEST ATLC N OF 24N W OF 74W. THIS PRECIPITATION IS ASSOCIATED TO A COLD FRONT THAT AS OF 2100 UTC IS EXTENDING FROM 30N80W TO 29N81W AND THEN ACROSS FLORIDA TO THE YUCANTAN PENINSULA. MOISTURE FROM THE E PACIFIC BEING ADVECTED BY UPPER LEVEL WESTERLY FLOW IS ENHANCING THIS CONVECTION. TWO SURFACE TROUGHS ARE OVER THE CENTRAL ATLC...THE WESTERNMOST TROUGH EXTENDS FROM A 1000 MB LOW N OF THE DISCUSSION AREA TO 30N47W 26N48W 23N52W. ISOLATED SHOWERS ARE UP TO 250 NM EAST OF THIS TROUGH AND 160 NM WEST OF IT. THE EASTERNMOST TROUGH EXTENDS FROM 30N38W TO 21N44W 14N55W. NUMEROUS SHOWERS ARE OCCURING N OF 21N BETWEEN 33W AND 44W. SURFACE RIDGING IS OVER THE E ATLC N OF 15 E OF 37W ANCHORED BY A 1018 MB HIGH LOCATED NEAR 27N23W. WITHIN 24 HOURS...THE FRONT ACROSS FLORIDA AND THE E GULF IS EXPECTED TO WEAKEN AND MOVE OVER THE WEST ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR