000 AXNT20 KNHC 041724 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU JAN 04 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 1N AT THE PRIME MERIDIAN TO 1S11W 2N20W 3N35W 2N43W CROSSING THE EQUATOR AT 50W. ISOLATED MODERATE CONVECTION IS WITHIN 240 NM N OF THE AXIS BETWEEN 21W-31W. ...DISCUSSION... GULF OF MEXICO... NUMEROUS SHOWERS AND TSTMS HAVE BEEN INCREASING IN COVERAGE AND INTENSITY TODAY ACROSS THE N CENTRAL GULF AND PORTIONS OF THE SRN STATES. THIS ACTIVITY IS MAINLY N OF 26N W OF 91W...BASED ON MOSAIC DOPPLER RADAR AND IR IMAGERY. THE UPPER LEVEL SUPPORT CONSISTS OF STRONG SWLY UPPER LEVEL WINDS TO THE E OF A NARROW RATHER VIGOROUS UPPER LOW CENTERED OVER N CENTRAL TEXAS. A RELATED SFC LOW PRES SYSTEM IS MOVING QUICKLY TO THE NE AND AS OF 15Z WAS LOCATED OVER NRN LA. A WARM FRONT STRETCHES EWD FROM THE LOW ALONG OR JUST S OF THE N GULF COAST AND ACROSS THE FL PANHANDLE. A COLD FRONT RUNS FROM THE LOW SWD TO MEXICO ALONG 26N94W 21N96W. THE STRONGEST ACTIVITY EXISTS BETWEEN THE FRONTS IN THE WARM SECTOR ENHANCED BY MOIST S-SE 15-20 KT SFC WINDS. A NOTICEABLE COOLER AIRMASS IS TRYING TO BUILD INTO THE NW GULF... BEHIND THE FRONT...WITH TEMPS AND DEW POINTS IN THE 40'S AND LOW 50'S F ACROSS E TEXAS. THE COLD FRONT WILL CONTINUE TO TRACK E ACROSS THE GULF BECOMING DIFFUSE IN THE ERN GULF TOMORROW AFTERNOON AS ITS UPPER SUPPORT WEAKENS. MEANWHILE...A STRONG COLD FRONT WILL DEVELOP AND MOVE OFF THE TEXAS COAST ON SAT. CARIBBEAN SEA... THE MAIN CONCERN IS THE STRONG WINDS WITH A GALE WARNING IN EFFECT FROM 11N TO 15N BETWEEN 74W AND 77W. SHIP...BUOY AND AN 1120 Z QSCAT PASS CONFIRM THIS WARNING. THE REMAINDER OF THE AREA HAS MODERATE TO STRONG ELY TRADES. LITTLE CHANGE IN THESE WINDS ARE EXPECTED OVER THE NEXT 24 HOURS WITH SEA CONDITIONS REMAINING HAZARDOUS. BESIDES FOR THE STRONG TRADES...THE WEATHER IS FAIRLY TRANQUIL AS ABUNDANT VERY DRY MID AND UPPER LEVEL AIR DOMINATES THE REGION. THIS DRY AIR IS BEING SUPPORTED BY AN UPPER LEVEL CONFLUENT PATTERN BETWEEN A STRONG UPPER HIGH CENTERED OVER HONDURAS AND TROUGHING EXTENDING ACROSS MUCH OF THE ERN CARIB. TYPICAL SMALL PATCHES OF LOW LEVEL MOISTURE...BENEATH THE STRONG MID LEVEL CAP...ARE BEING STIRRED UP AND CARRIED BY THE TRADE WINDS ACROSS THE REGION. MODELS SHOW THE MID AND UPPER LEVEL LAYERS OF DRY AIR REMAINING IN PLACE FOR AT LEAST THE NEXT DAY OR TWO. ATLANTIC OCEAN... STARTING IN THE WRN ATLC...BROKEN PATCHES OF MOISTURE IS BEING ADVECTED INTO THE AREA W OF 73W N OF 27N DRIVEN BY WLY UPPER LEVEL FLOW ON THE N PERIPHERY OF A STRONG RIDGE ANCHORED IN THE NW CARIB. A BROAD WEAK UPPER LEVEL TROUGH COVERS THE AREA TO THE E OF THE RIDGE ROUGHLY BETWEEN 50W AND 70W. GFS SHOWS THIS TROUGH SHARPENING AND EVENTUALLY BECOMING CUT OFF THIS WEEKEND/EARLY NEXT WEEK. IF THIS OCCURS...IT WILL LIKELY GENERATE AND SPREAD MOISTURE TO THE E OF THE CIRCULATION. AN ASSOCIATED SFC COLD FRONT ENTERS THE AREA NEAR 32N48W AND EXTENDS MAINLY WWD ALONG 29N56W 29N68W. THIS FRONT ACTS A SURGE IN NLY WINDS...AS INDICATED ON A RECENT QSCAT PASS. A BROKEN SWATH OF MOISTURE...PRODUCED BY UPPER DIFFLUENCE AND SOME LOW-LEVEL FORCING...COVERS THE AREA BETWEEN 46W-55W N OF 26N. A WEAK ILL-DEFINED SFC TROUGH IS LOCATED SE OF THE COLD FRONT ANALYZED FROM 30N42W TO 24N49W. THIS SFC FEATURE MAY BE RELATED TO AN UPPER LOW CENTERED NEAR 26N37W. A WIDE AREA OF BROKEN CLOUDINESS AND LIKELY SCATTERED SHOWERS LIE TO THE E OF THE UPPER LOW...N OF 18N BETWEEN 18W-35W...GENERATED AND DRIVEN BY STRONG S-SWLY UPPER LEVEL WINDS. THE SFC PATTERN IS DOMINATED BY HIGH PRES WITH THE CORE OF THESE SYSTEMS LOCATED N OF THE REGION. A 1034 MB HIGH IS LOCATED NEAR 36N17W AND A 1031 MB IS 300 NM NE OF BERMUDA NEAR 35N60W. THIS STRONG RIDGING IS INTERRUPTED BY THE COLD FRONT AND SFC TROUGH MENTIONED ABOVE. THE WEAK COLD FRONT IS PROGGED TO DISSIPATE TOMORROW WITH BROAD RIDGING STRETCHING ACROSS THE BASIN BLEMISHED BY A LINGERING SFC TROUGH IN THE CENTRAL ATLC. $$ CANGIALOSI