000 AXNT20 KNHC 201750 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI MAR 20 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... FROM 5N9W TO 1N20W...CROSSING THE EQUATOR ALONG 34W...INTO NE BRAZIL NEAR 2S44W. ISOLATED AND DISORGANIZED MODERATE SHOWERS ARE WITHIN 30 NM OF THE ITCZ BETWEEN 20W AND 23W. ...DISCUSSION... GULF OF MEXICO... A LOW PRESSURE TROUGH IS EXTENDING N OUT OF THE YUCATAN PENINSULA TO 27N90W. ISOLATED SHOWERS ARE ACCOMPANYING THE TROUGH AS IT SLOWLY DRIFTS TO THE W. A WEAKENING COLD FRONT IS CURRENTLY ACROSS THE FAR NORTHERN GULF...EXTENDING OFF THE WESTERN FLORIDA COAST NEAR 30N TO 29N90W...THEN INTO THE FAR NE TEXAS COAST NEAR 30N94W. THE FRONT IS FAIRLY WEAK...AND THERE ARE CLEAR SKIES IN THE VICINITY OF THE FRONT. A HIGH PRESSURE RIDGE AXIS EXTENDS ALONG THE S TEXAS AND MEXICO COAST. THERE ARE MOSTLY CLEAR SKIES OVER THE WESTERN GULF...EXCEPT FOR A FEW BROKEN CLOUDS AND ISOLATED SHOWERS NEAR 24N ASSOCIATED WITH A SMALL REGION OF WEAK INSTABILITY. IN THE UPPER LEVELS...A WEAK UPPER TROUGH OVER THE NW GULF WILL MOVE E INTO SAT...AS THE UPPER RIDGE ALONG THE WESTERN GULF COAST AMPLIFIES WHILE SLOWLY PROPAGATING E. CARIBBEAN SEA... 1100 UTC QSCAT WINDS INDICATE PREDOMINATELY NE TO E FLOW OVER THE AREA...WITH WINDS UP TO 25 KT ALONG THE COLOMBIAN COAST... DECREASING TO 5-10 KT IN THE NW CARIBBEAN SEA. WATER VAPOR IMAGERY INDICATES SUBSIDENCE ACROSS THE CARIBBEAN...EXCEPT FOR A FEW BROKEN CLOUDS AND ISOLATED SHOWERS S OF JAMAICA TO 15N DUE TO WEAK INSTABILITY. ALSO...AN AREA OF BROKEN CLOUDS HAVE FORMED N OF THE COLOMBIAN COAST...AS CYCLONIC TURNING AROUND THE LOW OVER COLOMBIA NEAR 10N74W HAS CREATED CONVERGENT FLOW. IN ADDITION...THE SUBTROPICAL JET FLOWING OVER THE YUCATAN IS CAUSING BROKEN CLOUDS OVER THE NW CARIBBEAN...AND IS EXPECTED TO MARGINALLY DESTABILIZE THE ATMOSPHERE S OF CUBA. CLOUD COVER WILL MOST LIKELY INCREASE SLIGHTLY OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... STRONG LOW PRESSURE IS CURRENTLY N OF THE DISCUSSION AREA NEAR 37N43W. QSCAT WINDS FROM 0900 UTC THIS MORNING INDICATE GALE FORCE WINDS N OF THE AREA...EXTENDING AS FAR S AS 34N. A COLD FRONT EXTENDS INTO THE AREA FROM THE LOW TO 32N38W...TURNS SW TO 27N42W TO 22N54W...THEN EXTENDS NE TO A 1012 MB LOW NEAR 27N73W. A LOW PRES TROUGH EXTENDS SW FROM THE LOW TO 21N77W. ISOLATED CONVECTION EXTENDS FROM 28N TO 31N BETWEEN 62W AND 67W...AND N OF THE FRONT FROM 26N TO 28N BETWEEN 68W AND 70W. ALSO...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT. CONDITIONS ASSOCIATED WITH THE COLD FRONT WILL IMPROVE OVER THE NEXT 24 HORUS...AS THE LOW MOVES NE AND THE SYSTEM SLOWLY WEAKENS. HOWEVER...CONDITIONS ASSOCIATED WITH THE AFOREMENTIONED LOW E OF FLORIDA ARE EXPECTED TO CONTINUE...AS THE LOW DRIFTS E. A 1024 MB HIGH PRESSURE N OF THE AREA NEAR 35N58W IS CURRENTLY EXTENDING A RIDGE INTO REGION TO 25N55W...BEHIND THE COLD FRONT. OTHERWISE...MAINLY CLEAR SKIES WITH A FEW AREA OF BROKEN CLOUDS DOMINATE THE WEATHER OVER THE REMAINDER OF THE ATLC...INDICATED BY THE SUBSIDENCE IN THE WATER VAPOR IMAGERY. IN THE UPPER LEVELS...A SLIGHTLY AMPLIFIED PATTERN EXTENDS ACROSS THE ATLC...WITH A PAIR OF TROUGHS NEAR 30N77W AND 30N45W...AND A BUILDING RIDGE NEAR 30N55W. A SLIGHTLY MORE AMPLIFIED RIDGE IS IN THE NE ATLC NEAR 30N27W. THE UPPER PATTERN IS EXPECTED TO CONTINUE BUCKLING UP AS IT PROPAGATES E OVER THE NEXT 24 HOURS. $$ JMK/MKH