000 AXNT20 KNHC 172337 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SAT FEB 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N10W 3N20W 2N35W CROSSING THE EQUATOR AT 41W INTO NE BRAZIL NEAR 3N47W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS FROM 20W-40W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE OVER NE BRAZIL NEAR THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A NEW COLD FRONT HAS ENTERED THE GULF TODAY. THIS FRONT IS EMBEDDED WITHIN DRY AIR...THUS LITTLE IN THE FORM OF SHOWERS IS EXPECTED. THIS FEATURE WILL RAPIDLY MOVE ACROSS THE AREA TONIGHT REINFORCING THE WINTER CONDITIONS ALREADY IN PLACE. THE FRONT IS FORECAST TO REACH SOUTH FLORIDA LATE TONIGHT. ANOTHER SHOT OF COLD AND DRY AIR WILL GRIP THE GULF AND THE STATE OF FLORIDA ON SUNDAY. WINDS WILL BRIEFLY INCREASE TO GALE FORCE BEHIND THE FRONT OVER THE MIDDLE AND E GULF LATE TONIGHT AND EARLY SUN AS HIGH PRES BUILDS OVER THE DEEP SOUTH AND NE MEXICO. OVERCAST LOW/MID CLOUDS WITH EMBEDDED LIGHT RAIN/DRIZZLE ARE COVERING THE SW GULF INCLUDING THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA. IN THE UPPER LEVELS...STRONG WLY WINDS ASSOCIATED WITH A SUBTROPICAL JET COVERS THE ENTIRE GULF. A BROAD UPPER TROUGH THAT EXTENDS FROM THE GREAT LAKES TO TEXAS WILL MOVE EWD ACROSS THE E US ON SUNDAY...DIGGING INTO THE E GULF OF MEXICO. THIS UPPER TROUGH IS SUPPORTING THE COLD FRONT MENTIONED ABOVE. CARIBBEAN SEA... A DIFFUSE FRONTAL BOUNDARY EXTENDS FROM THE WINDWARD PASSAGE TO THE HONDURAS/NICARAGUA BORDER. BROKEN/OVERCAST LOW/MID LEVEL CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE OVERRUNNING THE FRONTAL SYSTEM. MODERATE/STRONG EASTERLY TRADE WINDS DOMINATES THE ENTIRE CARIBBEAN. IN THE UPPER LEVEL...A BROAD RIDGE CENTERED OVER THE SW CARIBBEAN IS STILL IN CONTROL OF THE WEATHER PATTERN ACROSS THE BASIN. THIS RIDGE ALSO DOMINATES CENTRAL AMERICA AND N SOUTH AMERICA WITH DRY SINKING AIR ALOFT. THE DRIEST AIR IS LOCATED SOUTH OF HISPANIOLA. OVERCAST LOW/MID CLOUDS WITH EMBEDDED LIGHT RAIN ARE COVERING THE NW CARIBBEAN W OF 83W AND THE GULF OF HONDURAS. POCKETS OF LOW LEVEL MOISTURE WITH MAINLY LIGHT SHOWERS DRIVEN BY THE TRADE WINDS ARE MOVING FROM THE TROPICAL N ATLC INTO THE E CARIBBEAN. NLY WINDS WILL INCREASE ACROSS THE NW CARIBBEAN AND W CUBA ON SUNDAY AS HIGH PRES INVADES THE GULF OF MEXICO. ATLANTIC OCEAN... THE SURFACE RIDGE EXTENDS FROM THE CENTRAL GULF OF MEXICO INTO THE W ATLC W OF THE SLOW MOVING COLD FRONT THAT ENTERS THE AREA NEAR 32N52W THEN CONTINUES SW ALONG 27N60W TO THE TURKS AND CAICOS ISLANDS WHERE IT BECOMES STATIONARY. IT CONTINUES ACROSS CUBA INTO THE CARIBBEAN AS A DYING FRONTAL SYSTEM. A 220 NM WIDE BAND OF OVERCAST LOW/MID LEVEL CLOUDS AND ISOLATED SHOWERS IS RELATED TO THE FRONT. THE ASSOCIATED UPPER LEVEL TROUGH DIPS S OVER THE NW ATLC AND OVER THE E US WITH MOST OF THE UPPER LEVEL ENERGY N OF THE REGION. A SUBTROPICAL JET WITH WINDS OF 90 TO 130 KT THAT COVERS THE GULF EXTENDS INTO THE W ATLC ACROSS N FLORIDA THEN NE TO 32N70W AND BEYOND. UPPER RIDGE ANCHORED IN THE SW CARIBBEAN EXTENDS AN AXIS NE ACROSS PUERTO RICO/VIRGIN ISLANDS TO BEYOND 32N42W. AN UPPER TROUGH REMAINS OVER THE E ATLC EXTENDING FROM THE MADEIRA/CANARY ISLANDS INTO THE TROPICAL ATLC NEAR 12N40W. AT THE SURFACE...THE E ATLC IS DOMINATED BY A SURFACE RIDGE THAT EXTENDS FROM A 1028 MB HIGH JUST SE OF THE AZORES TO THE NE CARIBBEAN SUPPLYING MOSTLY FAIR WEATHER AND MODERATE TRADES ACROSS A GOOD PORTION OF THE REGION. ONLY PATCHES OF LOW LEVEL MOISTURE ARE UNDER THE INFLUENCE OF THIS RIDGE. $$ GR