000 AXNT20 KNHC 060004 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN MAR 05 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...WEATHER OBSERVATIONS... RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...THE ITCZ... 6N10W 4N20W 1N30W...TO THE EQUATOR AT 40W AND THE EQUATOR AT 50W. ISOLATED MODERATE SHOWERS ARE WITHIN 30 NM ON EITHER SIDE OF 5N13W 4N20W 2N33W...AND WITHIN 150 NM ON EITHER SIDE OF 2N33W TO THE EQUATOR AT 42W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FOUND FROM 2S TO 5N BETWEEN 42W AND 50W. SCATTERED STRONG THUNDERSTORMS ARE IN NORTHEASTERN BRAZIL FROM 4S TO 1S BETWEEN 49W AND 52W. ...DISCUSSION... THE GULF OF MEXICO AND THE ATLANTIC OCEAN WEST OF 50W... MIDDLE TO UPPER LEVEL WESTERLY TO NORTHWESTERLY FLOW IS MOVING ACROSS THE OPEN GULF WATERS. A LOT OF THIS FLOW APPEARS TO BE MOVING TOWARD THE BASE OF THE DEEP LAYER TROUGH ALONG 65W. SURFACE HIGH PRESSURE IS WELL-ESTABLISHED FROM THE SOUTHEASTERN U.S.A. TOWARD THE MEXICO GULF COAST AND THE YUCATAN CHANNEL. THE 65W DEEP LAYER TROUGH SUPPORTS THE SURFACE COLD FRONT WHICH PASSES THROUGH 32N51W TO 24N60W TO 22N65W. THE FRONT STARTS TO DISSIPATE NEAR 22N65W AND IT CONTINUES TO 21N70W AND 19N72W ALONG THE HAITI/DOMINICAN REPUBLIC BORDER. SHOWERS AND THUNDERSTORMS ARE WITHIN 180 NM ON EITHER SIDE OF 24N54W BEYOND 32N46W. BROKEN LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE PRECIPITATION ARE WITHIN 90 NM ON EITHER SIDE OF 24N54W 20N57W 17N60W 16N62W 15N67W. A SURFACE TROUGH IS ALONG 25N55W 20N59W 17N64W. MIDDLE TO UPPER LEVEL DRY AIR IS WEST OF 30N51W 20N57W AND NORTH OF 20N IN THE ATLANTIC WATERS...AND EVERYWHERE ELSE IN THE GULF OF MEXICO EXCEPT NORTH OF 26N EAST OF 88W. HIGH LEVEL MOISTURE IS MOVING SOUTHEASTWARD IN THIS AREA NORTH OF 26N EAST OF 88W. THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST INTO THE EASTERN UNITED STATES AND THE MIDDLE TO UPPER LEVEL FLOW OVER THE GULF OF MEXICO IS FORECAST TO BECOME WESTERLY AND NORTHWESTERLY DURING THE NEXT 24 HOURS. AN ASSOCIATED COLD FRONT IS EXPECTED TO APPROACH THE NORTHWESTERN AND NORTHERN GULF COAST ON MONDAY. SURFACE HIGH PRESSURE WILL BECOME ORIENTED EAST TO WEST ACROSS THE GULF ALONG 25N/26N. THE TROUGH WILL DEEPEN OVER THE EASTERN U.S.A. BY MONDAY NIGHT...AND A STRONG MID LEVEL RIDGE IS FORECAST TO BUILD FROM MEXICO NORTHWARD ACROSS THE WESTERN PLAINS. THE CARIBBEAN SEA... NORTHWESTERLY MIDDLE LEVEL FLOW MOVES THROUGH THE YUCATAN CHANNEL AND ACROSS MEXICO INTO THE NORTHWESTERN CORNER OF THE AREA...TOWARD JAMAICA. MIDDLE TO UPPER LEVEL SOUTHWESTERLY WIND FLOW IS SOUTH AND SOUTHEAST OF THE LINE FROM NORTHERN NICARAGUA TO SOUTHERN JAMAICA AND SOUTHWESTERN HAITI. THIS MOVES ACROSS CENTRAL AMERICA SOUTH OF NICARAGUA INTO THE OPEN CARIBBEAN WATERS. THE SOUTHWESTERLY FLOW EVENTUALLY BECOMES MORE WESTERLY AS IT CROSSES 70W. MIDDLE TO UPPER LEVEL DRY AIR IS EVERYWHERE. THE ATLANTIC OCEAN EAST OF 50W... DEEP LAYER MOISTURE IS WITHIN 250 NM ON EITHER SIDE OF 25N51W BEYOND 32N47W...TO THE EAST OF THE 65W DEEP LAYER TROUGH. A SURFACE RIDGE COVERS THE ATLANTIC WATERS FROM 11N56W TO 19N51W 22N44W 26N39W 29N35W TO A 1033 MB HIGH PRESSURE CENTER NEAR 36N22W. ONE UPPER LEVEL ATLANTIC RIDGE IS ALONG 26N44W 8N49W IN THE MIDDLE OF DRY AIR. AN UPPER LEVEL RIDGE ALONG 28W FROM 30N NORTHWARD IS ON TOP OF A MIDDLE LEVEL LOW CENTER NEAR 22N24W. CYCLONIC FLOW AROUND THIS LOW CENTER COVERS THE ATLANTIC WATERS FROM 8N TO 27N BETWEEN AFRICA JUST EAST OF 10W TO 33W ON THE EAST SIDE OF THE 26N44W 8N49W RIDGE. $$ MT