000 AXNT20 KNHC 181113 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON FEB 18 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 4N18W 3N26W 1N37W 2N46W 1N51W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 120/150 NM OF THE ITCZ AXIS FROM 21W-33W AND CLUSTERS OF SIMILAR CONVECTION ARE WITHIN 60 NM OF LINE FROM 4N8W ACROSS THE ITCZ AXIS TO 6N15W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM N OF THE ITCZ AXIS FROM 33W-39W. CLUSTERS OF SIMILAR CONVECTION COVER THE ARE FROM 4N TO S OF THE EQUATOR BETWEEN 34W-42W. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH COVERS THE E HALF OF THE U.S. INTO THE GULF N OF 23N TO OVER THE FLORIDA PENINSULA WITH A COMPLEX FRONTAL SYSTEM. THE LEADING COLD FRONT ENTERS THE GULF NEAR PANAMA CITY FLORIDA TO A WEAKENING 1009 MB LOW IN THE CENTRAL GULF NEAR 27N91W CONTINUING TO 23N96W A WEAK OROGRAPHICALLY INDUCED 1008 MB LOW IS JUST N OF THE BAY OF CAMPECHE NEAR 21N95W. A SECOND REINFORCING COLD FRONT ENTERS THE GULF OVER MOBILE BAY ALABAMA SW ACROSS THE MISSISSIPPI DELTA OF LOUISIANA TO INLAND OVER TEXAS BETWEEN CORPUS CHRISTI AND BROWNSVILLE. A SQUALL LINE CONSISTING OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IS AHEAD OF THE EASTERN FRONT EXTENDING WITHIN 45 NM OF LINE FROM 26N89W ACROSS FLORIDA NEAR THE BIG BEND AREA WEAKENING OVER SE GEORGIA CONTINUING ALONG THE COAST OF THE CAROLINAS. POLAR JET REMAINS OVER THE N GULF COAST AND MERGES WITH THE SUBTROPICAL JET WHICH EXTENDS N OF A LINE FROM OFF THE TEXAS COAST NEAR 22N94W ACROSS FLORIDA JUST S OF LAKE OKEECHOBEE. MAXIMUM UPPER LEVEL WINDS OF 120 KT WITHIN THE JET ARE OVER THE N GULF COAST N OF 29N FROM PANAMA CITY FLORIDA TO VERMILION BAY LOUISIANA. THE REINFORCING COLD FRONT IS EXPECTED TO CONTINUE TO MOVE ACROSS THE GULF TONIGHT AND GIVE THE FIRST BOUNDARY AN EXTRA PUSH...THEN MERGING AND MOVING INTO THE E GULF AND FLORIDA LATE TODAY. CARIBBEAN... BROAD UPPER LEVEL RIDGE IS ANCHORED OVER SOUTH AMERICA AND THE AXIS CENTERED ALONG 76W INTO THE W ATLC. BROAD SW FLOW ALOFT IS DRAWING MOISTURE FROM THE E PACIFIC ACROSS CENTRAL AMERICA AS FAR N AS CUBA MOSTLY AS THIN HIGH CLOUDS. FARTHER E...UPPER LEVEL WINDS ARE MORE CONFLUENT AND THUS STRONG SUBSIDENCE AND DRY STABLE AIR COVERS THE E CARIBBEAN INCLUDING THE LESSER ANTILLES. FRESH TO STRONG EASTERLY TRADE WINDS ARE USHERING IN SOME PATCHES OF SHOWERS MOSTLY N OF 14N E OF 74W INCLUDING THE PORTIONS OF LESSER ANTILLES. LITTLE CHANGE IS EXPECTED ACROSS THE REGION FOR THE FIRST OF THE WEEK. ATLANTIC... THE UPPER RIDGE AXIS FROM THE CARIBBEAN EXTENDS TO BEYOND 32N ALONG 76W COVERING THE AREA W OF 60W. A DEEP LAYERED TROUGH IS OVER THE W/CENTRAL ATLC N OF 18N FROM 40W-60W WITH THE ASSOCIATED COLD FRONT ENTERING THE REGION NEAR 32N44W EXTENDING SW TO 29N54W THEN DISSIPATING TO NEAR 30N60W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM E OF THE FRONT. THE REMNANTS OF A FRONTAL BOUNDARY...SURFACE TROUGH EXTENDS FROM 29N39W ALONG TO 26N49W WITH POSSIBLE ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE TROUGH. A SURFACE RIDGE CONTINUES TO BUILD S OVER THE W ATLC BRIDGING THE FRONT AND COVERING THE AREA FROM 30W TO JUST E OF THE BAHAMAS. THE TYPICAL E/W UPPER RIDGE COVERS THE TROPICS AND A JETSTREAM WITH MAX WINDS OF 110 KT IS WITHIN 175/275 NM ALONG THE N PERIPHERY EXTENDING FROM 17N40W 25N23W ACROSS THE CANARY ISLANDS TO INLAND OVER W AFRICA NEAR 29N13W. THIS UPPER FLOW IS ALSO ADVECTING TROPICAL MOISTURE WITHIN 150 NM OF LINE FROM 10N41W N OF THE CAPE VERDE ISLANDS TO W AFRICA NEAR 21N16W. $$ WALLACE