000 AXNT20 KNHC 012344 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SAT MAR 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... ITCZ AXIS ALONG 6N10W 2N20W...CROSSING THE EQUATOR NEAR 33W... 2S42W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS LOCATED S OF 2N TO THE S AMERICA COAST W OF 40W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM S OF THE AXIS E OF 13W TO THE AFRICAN COAST. ...DISCUSSION... GULF OF MEXICO... SHEARING MID TO UPPER LEVEL TROUGH EXTENDS FROM THE CAROLINA COAST SWWD ACROSS THE GULF COAST TO THE UPPER TEXAS COAST NEAR 29N94W. VERY STRONG UPPER LEVEL SUBSIDENCE WAS NOTED IN THE WAKE OF THE TROUGH ACROSS THE GULF N OF 29N AND THE ADJACENT COAST. SATELLITE DERIVED WINDS INDICATED A BELT OF WSW WINDS OF 75-90 KNOTS ACROSS THE CENTRAL GULF WITH A 240 NM WIDE BAND OF MAINLY UPPER LEVEL MOISTURE CENTERED ALONG TAMPA BAY-26N90W TO THE NE MEXICAN COAST NEAR 25N97W. UPSTREAM MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW AND RIDGING EXTENDING FROM THE INTERMOUNTAIN REGION TO TEXAS IS EXPECTED TO SPREAD OVER THE GULF OVER THE NEXT 24 HOURS. AT THE SURFACE A 1027 MB HIGH WELL N OF THE AREA OVER THE TENNESSEE RIVER VALLEY IS BUILDING INTO THE GULF. A WEAK SURFACE TROUGH HAS DEVELOPED AT 21 UTC OVER THE SW GULF AND BAY OF CAMPECHE FROM 24N95W TO THE MEXICAN COAST JUST E OF COATZACOALCOS. SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM WERE NOTED ALONG THE TROUGH NEAR 21N95.5W. THIS TROUGH IS EXPECTED TO MOVE W AND WEAKEN OVER THE NEXT 24 HOURS AS SOUTHERLY RETURN FLOW INCREASES OVER THE WRN GULF ON SUN. CARIBBEAN SEA... A BROAD MID TO UPPER LEVEL RIDGE COVERS VIRTUALLY THE ENTIRE CARIBBEAN WITH WATER VAPOR IMAGERY INDICATING MODERATE TO STRONG SUBSIDENCE OVER THE AREA. WESTERLY WINDS ARE STRONGEST ACROSS THE ATLANTIC PASSAGES THROUGH JAMAICA TO EASTERN HONDURAS WITH SATELLITE DERIVED WINDS UP TO 50-60 KNOTS. SOME HIGH CLOUDS WERE NOTED IN PROXIMITY TO THE CORE OF THE HIGHEST WINDS ALOFT. THE FLOW WEAKENS TO 20 KNOTS OVER THE SOUTHEASTERN CARIBBEAN. AT THE SURFACE A WEAKENING FRONTAL TROUGH EXTENDS THROUGH EASTERN CUBA TO NORTHERN BELIZE NEAR 18N88W. WIDELY SCATTERED WESTWARD MOVING SHOWERS ARE LOCATED WITHIN A 60-90 NM EITHER SIDE OF THE FRONTAL TROUGH. STRONG ELY TRADES CONTINUE OVER THE SW PART OF THE CARIBBEAN WHERE NE WINDS ARE IN THE 25 TO 30 KT RANGE WITH SEAS 9 TO 14 FT. ATLANTIC OCEAN... THE STRONG WESTERLY FLOW AT THE MID AND UPPER LEVELS NOTED OVER THE GULF OF MEXICO CONTINUES EASTWARD INTO THE ATLANTIC TO ABOUT 55W N OF 20N. SATELLITE DERIVED WINDS INDICATED THE STRONGEST WINDS OF 90-100 KNOTS ARE W OF 70W. THE STRONG WINDS WERE ADVECTING MAINLY HIGH LEVEL MOISTURE WITHIN 150 NM EITHER SIDE OF ALINE THROUGH 32N69W TO THE E-CENTRAL FLORIDA COAST NEAR VERO BEACH. AT THE SURFACE A STATIONARY FRONT EXTENDED THROUGH 32N49W THROUGH 25N65W TO THE E COAST OF CUBA NEAR 21N76W. SCATTERED SHOWERS WERE NOTED WITHIN 120 NM OF THE FRONT MAINLY BETWEEN 63W AND 75W. FURTHER DOWNSTREAM...A LARGE WELL-DEFINED MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION...ABOUT 12 DEG IN DIAMETER...IS CENTERED OVER THE E ATLANTIC NEAR 28N27W AND IS BEGINNING TO LIFT OUT TO THE NE. THERE ARE INDICATIONS THAT A SURFACE LOW MAY BE FORMING IN ASSOCIATION WITH THIS UPPER SYSTEM AND MAY BE INCLUDED ON THE SUBSEQUENT 00 UTC SURFACE ANALYSIS. IN ANY EVENT THE ASSOCIATED UPPER TROUGH AXIS EXTENDS SW FROM THE CIRCULATION THROUGH 21N30W AND BECOMES SHEARED TO NEAR 13N47W. A NARROWING REGION OF STRONG UPPER LEVEL SUBSIDENCE IS NOTED WITHIN 180 NM EITHER SIDE OF THE SHEARED TROUGH AXIS S OF 18N. A 80 TO 100 KNOT JET ORIGINATES FROM CLOSE TO THE BASE OF THE TROUGH NEAR 11N45W THROUGH 16N30W TO THE COAST OF AFRICA/WESTERN SAHARA AT 24N. $$ COBB