000 AXNT20 KNHC 072351 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU DEC 07 2006 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 5N30W 4N50W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE SEEN WITHIN 60 NM OF THE AXIS BETWEEN 29W-47W. ...DISCUSSION... THE GULF OF MEXICO... ZONAL UPPER FLOW IS CARRYING ABUNDANT UPPER MOISTURE AND HIGH CLOUDS E ACROSS MUCH OF THE GULF THIS EVENING. THIS IS MAKING IT DIFFICULT TO FIND THE EXACT PLACEMENT OF THE COLD FRONT MOVING THROUGH. AS OF 2100 UTC...THE COLD FRONT EXTENDS E FROM THE TAMPA AREA TO 27N84W. THE FRONT IS WARM FROM THIS POINT TO THE SFC LOW NEAR 26N85W...AND COLD THROUGH THE WRN GULF TO 24N96W. THIS BOUNDARY IS GENERALLY AT THE LEADING EDGE OF A STRONG 1045 MB HIGH BUILDING INTO THE NRN GULF FROM KANSAS. THE LOW IN THE EAST CENTRAL GULF HAS NOT BEEN HANDLED WELL BY THE MODELS...AND LIKELY CONTAINS SCATTERED TO NUMEROUS SHOWERS ESPECIALLY IN THE NRN AND ERN SEMICIRCLES OUT 150 NM AS ESTIMATED BY SATELLITE IMAGERY. A GALE WARNING IS IN EFFECT FOR THE WRN GULF N OF 22N WITH RAPIDLY INCREASING NE WINDS AND WIND WAVES. THESE CONDITIONS GRADUALLY SUBSIDE THROUGH THE WEEKEND AS THE HIGH WEAKENS AND SHIFTS E. BROWNSVILLE RADAR SHOWING A FAIRLY WIDESPREAD REGION OF LIGHT RAIN IN THE AREA...WITH SOME WEAK SFC TROUGHING AND ISENTROPIC LIFT OVER THE WRN GULF. MODEL CONSENSUS SUGGESTS THE WRN GULF/COASTAL MEXICO WILL CONTINUE TO SEE THE PRECIP MAXIMA OVER THE GULF INTO THE WEEKEND...WITH WEAK TROUGHING PERSISTING. CARIBBEAN SEA... DRY MID TO UPPER AIR CONTINUES TO DOMINATE MUCH OF THE CARIBBEAN THIS EVENING. THE LARGE SCALE UPPER PATTERN OVER THE CARIBBEAN IS DOMINATED BY AN UPPER RIDGE OVER MUCH OF THE CENTRAL AND WRN PORTION...WITH THE AXIS EXTENDING FROM THE SW PORTION THROUGH HISPANIOLA. A WEAK UPPER TROUGH CONTINUES TO EXTEND THROUGH THE LEEWARD ISLANDS INTO THE NE CARIBBEAN. SCATTERED LOW CLOUDS WITH ISOLATED SHOWERS CONTINUED TO BE ADVECTED W THROUGH THE CARIBBEAN WITH THE TRADES...WHICH ARE GENERALLY IN THE 15 TO 25 KT RANGE. NE FLOW EXPECTED TO INCREASE OVER THE NW PORTION FRI EVENING INTO SAT AS STRONGER HIGH PRESSURE BUILDS N OF THE AREA. THE SFC TROUGH THAT IS ALONG 12N75W 29N75W WILL LIKELY BE REMOVED FROM THE CARIBBEAN AT 00Z...AS THE CYCLONIC TURNING IN THE AREA SEEMS MORE ASSOCIATED WITH THE NATURAL TRADE FLOW THROUGH THE AREA AND AROUND THE COLOMBIAN LOW. THE ATLANTIC OCEAN... A COLD FRONT IS PUSHING INTO THE SW NORTH ATLC JUST OFF THE COAST OF NE FLORIDA. STRONG HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE FRONT FRIDAY AND SATURDAY...ALLOWING NE WINDS AND WIND WAVES TO INCREASE. A GALE WARNING IS IN EFFECT FOR THIS STARTING LATE TONIGHT OFF THE COAST OF N FLORIDA...SEE MIAHSFAT2 FOR DETAILS. SCATTERED MODERATE CONVECTION IS AHEAD OF THE FRONT N OF 26N BETWEEN 69W-74W...WHICH SEEMS ALIGNED WITH A PREFRONTAL TROUGH. THIS AREA ALSO SUPPORTED BY UPPER DIFFLUENT AIR BETWEEN THE LARGE SCALE TROUGHING OVER THE ERN US WITH THE UPPER RIDGE EXTENDING NE THROUGH HISPANIOLA AND INTO THE CENTRAL ATLC. A PRONOUNCED UPPER LOW IS SEEN SPINNING NEAR 19N36W. ABUNDANT UPPER MOISTURE IS S AND SE OF THIS FEATURE...WITH SCATTERED SHOWERS POSSIBLE FROM 9N-22N BETWEEN AFRICA AND 35W. THE SFC PATTERN IN THE E AND CENTRAL ATLC DOMINATED BY THE SOUTH SIDE OF HIGH PRESSURE...WITH A 1030 MB CENTER NEAR 32N31W. WLY JET OVER THE DEEP TROPICS CONTINUES TO SHEAR THE CONVECTION OVER THE ITCZ TO THE E. $$ WILLIS