000 AXNT20 KNHC 201754 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST MON MAR 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 2.5N20W 2N30W EQ40W. SCATTERED MODERATE/STRONG CONVECTION ALONG THE AXIS BETWEEN 13W-16W. SCATTERED SHOWERS/TSTMS WITHIN 150 NM NORTH OF THE AXIS BETWEEN 23W-36W. A CLUSTER OF MODERATE/STRONG CONVECTION IS OVER THE GULF OF GUINEA...MOVING WESTWARD. SIMILAR CONVECTION IS FOUND WITHIN 50 NM OF LINE 2N6W 2N10W. ...DISCUSSION... GULF OF MEXICO... STRONG MID/UPPER LEVEL RIDGE DOMINATES THE GULF OF MEXICO WITH THE MAIN MID-LEVEL HIGH CENTERED OVER THE YUCATAN PENINSULA. A POTENT SUBTROPICAL JET WITH 300 MB WIND SPEEDS NEAR 100 KT IS RIDING UP AND OVER THE RIDGE FROM N/CENTRAL MEXICO INTO CENTRAL TEXAS AND OKLAHOMA. MODERATE TO STRONG SELY LOW-LEVEL FLOW HAS DEVELOPED OVER THE AREA S OF A WARM FRONT WHICH EXTENDS OVER THE NORTH GULF STATES FROM SE TEXAS TO NORTH FLORIDA. RADAR IMAGERY ACROSS THE N GULF COAST REGION INDICATES THAT A STRONG SQUALL LINE IS CURRENTLY PUSHING EWD ACROSS EASTERN TEXAS AND LOUISIANA. SCATTERED HIGH CLOUDS COVERS THE GULF WEST OF 90W. UNDER A SE WIND FLOW...LINES OF LOW LEVEL CLOUDS ARE OBSERVED OVER THE EASTERN HALF OF THE GULF. AS OF 1500 UTC...A COLD FRONT WHICH EXTENDS ACROSS SOUTH TEXAS AND NE MEXICO WILL MOVE OFF THE TEXAS COAST LATER THIS AFTERNOON WITH A CHANCE OF SHOWERS AND TSTMS AHEAD OF THE BOUNDARY PRIMARILY NEAR THE N GULF COAST. THE FRONT AND ITS ASSOCIATED SHOWER ACTIVITY WILL MOVE E/SE TOWARDS NORTHERN FLORIDA...THE CENTRAL GULF AND ALONG THE COAST OF MEXICO NEAR TAMPICO BY EARLY TUE MORNING. CARIBBEAN... MAINLY ZONAL WESTERLIES COVER THE ENTIRE CARIBBEAN BASIN IN THE UPPER LEVELS WHILE A FAIRLY STRONG MID-LEVEL ANTICYCLONE IS CENTERED OVER THE YUCATAN PENINSULA. MODERATE/STRONG SUBSIDENCE DOMINATES THE GREATER/LESSER ANTILLES...CENTRAL AMERICA AND THE CARIBBEAN SEA. ONLY A FEW TRADE SHOWERS ARE SEEN OVER THE AREA. VISIBLE SATELLITE IMAGERY SHOWS AN AREA OF AFRICAN DUST ACROSS THE TROPICAL ATLC SOUTH OF 20N BETWEEN THE LESSER ANTILLES AND 45W. SAINT VINCENT AND GRENADA ARE REPORTING HAZY CONDITIONS. MODERATE TRADE WINDS WILL PERSIST ACROSS THE BASIN THROUGH AT LEAST WEDNESDAY. ATLANTIC... A LARGE UPPER LEVEL LOW LOCATED NEAR THE SE TIP OF NEWFOUNDLAND WITH A LARGE CIRCULATION IS PRODUCING UPPER LEVEL WESTERLIES AS SOUTH AS THE BAHAMAS AND GREATER ANTILLES. AT THE SURFACE...TWO COLD FRONTS ARE OVER THE AREA. THE FIRST ONE ENTERS THE CENTRAL ATLC NEAR 31N48W...THEN CONTINUES SW TO 23N69W. A LINE OF BROKEN LOW/MID LEVEL CLOUDS WITH ISOLATED SHOWERS IS ASSOCIATED WITH THE FRONT. THE SECOND ONE IS ALONG 31N41W 25N50W 23N56W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM EAST OF THE FRONT FROM 27.5N-35N AND BEYOND. FARTHER E...A MID/UPPER LEVEL RIDGE IS NORTH OF 20N BETWEEN 20W-40W WITH A 1020 MB SURFACE HIGH NEAR 27.5N30.5W. AN UPPER LEVEL TROUGH COVERS THE REMAINDER OF THE ATLC. ITS AXIS CROSSES THE CANARY AND CAPE VERDE ISLANDS. ELSEWHERE...A SUBTROPICAL JET STREAK AND ASSOCIATED HIGH LEVEL CIRRUS LIE OVER W AFRICA. OF NOTE...TODAY MARKS THE BEGINNING OF THE SPRING IN THE NORTHERN HEMISPHERE. AT 1:26 PM EST THE SUN WILL CROSS DIRECTLY THE EARTH'S EQUATOR. THIS MOMENT IS KNOWN AS A VERNAL EQUINOX. BECAUSE THE SUN IS POSITIONED OVER THE EQUATOR...DAY AND NIGHT ARE ABOUT EQUAL IN LENGTH ALL OVER THE WORLD DURING THE EQUINOXES. $$ GR