000 AXNT20 KNHC 050005 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SAT DEC 04 2010 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. ...ITCZ... ITCZ AXIS IS ANALYZED ALONG 09N13W 07N22W 08N40W 05N50W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ AND ANALYZED FROM 02N-10N ALONG 51W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 180 NM N OF THE ITCZ AXIS BETWEEN 39W-50W. ...DISCUSSION... GULF OF MEXICO... CONVERGENT FLOW ALOFT OVER THE GULF IS LEADING TO WIDESPREAD SUBSIDENCE IN SUPPORT OF A BROAD 1022 MB HIGH CENTERED NEAR 26N88W. THIS SURFACE HIGH IS PROVIDING THE ENTIRE GULF WITH FAIR CONDITIONS AND MOSTLY CLEAR SKIES THIS AFTERNOON. SURFACE WINDS ACROSS THE GULF ARE ALL BELOW 20 KT. THROUGH THE WEEKEND...AS THE HIGH SHIFTS SOUTHWESTWARD AND WEAKENS SLIGHTLY...A COLD FRONT CURRENTLY INLAND OVER CENTRAL TEXAS WILL BEGIN TO IMPACT THE GULF COAST AND NORTHERN GULF WATERS SUNDAY MORNING. BY LATE SUNDAY...N TO NE WINDS BEHIND THE FRONT WILL SPREAD SOUTHWARD AS THE FRONT REACHES THE CENTRAL GULF OF MEXICO. CARIBBEAN SEA... CONVERGENT UPPER LEVEL WESTERLIES AND SOUTHWESTERLIES DOMINATE THE WESTERN AND CENTRAL CARIBBEAN...LEADING TOWARD GENERALLY CLEAR WEATHER WITH NO ORGANIZED DEEP CONVECTION. FARTHER EAST...UPPER LEVEL RIDGING EXISTS ALONG 12N AND SCATTERED MODERATE ISOLATED DEEP CONVECTION HAS BEEN OCCURRING TODAY ALONG THE NORTHERN COAST OF VENEZUELA AND THE ABC ISLANDS. NO OBVIOUS SURFACE FEATURE IS CONNECTED WITH THIS CONVECTIVE ACTIVITY. A WEAKENING COLD FRONT EXTENDS SOUTHWESTWARD FROM THE ATLANTIC OCEAN INTO HISPANIOLA. FROM THERE...A SHEAR LINE CONTINUES SOUTHWESTWARD TO JAMAICA AND ENDS JUST EAST OF HONDURAS. NO DEEP CONVECTION IS OCCURRING WITH THESE BOUNDARIES...THOUGH THERE MAY BE SOME SHALLOW CLOUD RAINFALL OCCURRING ALONG THE BOUNDARIES...ESPECIALLY IN HISPANIOLA. SURFACE WINDS THROUGHOUT THE CARIBBEAN ARE GENERALLY 20 KT OR LESS OUT OF THE NORTHEAST AS THE SURFACE PRESSURE GRADIENT IS RELAXED. THESE WEAK TO MODERATE WINDS SHOULD CONTINUE FOR THE NEXT DAY OR SO...WITH THE NEXT COOL FRONT IMPACTING THE NW CARIBBEAN ON MONDAY. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS LOCATED OVER THE W ATLC WITH AXIS EXTENDING FROM 32N63W TO 22N70W. THIS UPPER LEVEL FEATURE SUPPORTS A PRIMARY COLD FRONT ANALYZED FROM 32N55W SW ALONG 25N60W TO OVER HISPANIOLA. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. BEHIND THE FRONT...WINDS IN OUR REGION ARE W TO NW 20 TO 25 KT. IN THE EXTREME NORTHERN PORTION OF OUR REGION...SW WINDS AHEAD OF A SECOND FRONTAL SYSTEM SHOULD MAY REACH GALE FORCE W OF 68W TONIGHT AND BETWEEN 63W AND 73W TOMORROW. EAST OF THE COLD FRONT...A WEAK 1016 MB HIGH PRESSURE IS CENTERED NEAR 23N53W IS CONTRIBUTING TOWARD RELATIVELY WEAK SURFACE WINDS ACROSS MOST OF THE TROPICAL AND SUBTROPICAL NORTH ATLANTIC. IN THE FAR EAST ATLANTIC...A COOL FRONT EXTENDS SOUTHWESTWARD FROM 32N25W TO 22N35W AND A DISSIPATING COOL FRONT EXTENDS SOUTHWESTWARD FROM 32N19W TO 21N28W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE COOL FRONT. AFTERNOON PASSES FROM BOTH THE ASCAT AND WINDSAT SCATTEROMETERS INDICATED GALE FORCE SW WINDS N OF 28N BETWEEN 20W AND 30W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LANDSEA/HUFFMAN