000 AXNT20 KNHC 121751 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAR 12 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... THE ITCZ AXIS IS CENTERED ALONG 6N9W CROSSING THE EQUATOR NEAR 23W TO 4S30W AND INTO NE BRAZIL NEAR 6S35W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 3N-6N BETWEEN 10W-15W. ISOLATED MODERATE CONVECTION IS S OF 2N BETWEEN 20W-24W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONTAL BOUNDARY EXTENDS ACROSS SRN GEORGIA AND ENTERS THE GULF OF MEXICO NEAR PANAMA CITY FLORIDA. THE FRONT CONTINUES THROUGH THE MISSISSIPPI RIVER DELTA REGION TO 29N93W WHERE IT TRANSITIONS INTO A SLOWLY EWD MOVING COLD FRONT ALONG 28N96W 24N97W AND INLAND OVER MEXICO NEAR 23N98W. DOPPLER RADAR AND VISIBLE SATELLITE DATA INDICATE SCATTERED SHOWERS PRIMARILY NORTH OF THE FRONT WEST OF 88W. THE UPPER SHORTWAVE TROUGH SUPPORTING THE BOUNDARY CONTINUES TO MOVE OFF TO THE NE AS AN UPPER RIDGE IS LOCATED ACROSS THE W ATLC AND FLORIDA PENINSULA. GLOBAL MODELS FORECAST ANOTHER SHORTWAVE TROUGH TO COME INTO PHASE WITH THE FRONT SAT WHICH MAY PROVIDE SOME SUPPORT TO MAKE IT PROGRESSIVE ONCE AGAIN. ELSEWHERE...THE PREVIOUSLY MENTIONED DEEP LAYERED RIDGING CENTERED E OF THE AREA REMAINS IN CONTROL ACROSS THE ERN AND SW GULF THIS AFTERNOON PROVIDING FAIR CONDITIONS AND LIGHT TO MODERATE E-SE SFC WINDS. CARIBBEAN SEA... HIGH PRESSURE CENTERED A COUPLE HUNDRED NM W OF BERMUDA IS GENERATING MODERATE TO FRESH TRADES ACROSS THE CARIBBEAN. SURFACE OBS AND AN EARLIER QSCAT PASS SUGGEST THAT THE STRONGEST FLOW...20-25 KT...IS OVER THE S/CENTRAL CARIBBEAN WITH WINDS REACHING 30 KT NEAR THE COAST OF COLOMBIA BETWEEN 73W-77W. TYPICAL PATCHES OF LOW-LEVEL CLOUDS AND ISOLATED SHOWERS ARE SCATTERED ACROSS THE BASIN. MOST NOTABLY NE WINDS ARE USHERING IN THESE SHOWERS ACROSS THE NE CARIBBEAN N OF 15N E OF 70W. IN THE MID AND UPPER LEVELS...STRONG SUBSIDENCE PREVAILS OVER THE ENTIRE BASIN WITH A LARGE CONFLUENCE ZONE OVER THE ERN CARIBBEAN. LITTLE CHANGE IN THE LARGE SCALE WEATHER PATTERN IS ANTICIPATED OVER THE NEXT DAY OR SO. ATLANTIC OCEAN... AN OCCLUDED 1000 MB LOW PRESSURE SYSTEM IS CENTERED NEAR 31N45W AND CONTINUES TO MOVE ESE AT 15 KT. THE ATTENDANT WEAKENING COLD FRONT EXTENDS FROM THE TRIPLE POINT NEAR 34N40W SWD ALONG 30N40W 20N48W THEN AS A SURFACE TROUGH TO 17N60W. SCATTERED SHOWERS ARE WITHIN 60 NM E OF THE FRONT N OF 24N. A SECONDARY SURFACE TROUGH IS ANALYZED FROM JUST E OF THE LOW CENTER NEAR 30N43W SW TO 21N51W. INSTABILITY NEAR THE LOW CENTER AND ALONG THE TROUGH IS TRIGGERING SCATTERED SHOWERS WITHIN 30 NM EITHER SIDE OF THE TROUGH. WINDS TO GALE FORCE ARE BLOWING WITHIN THE COLD SECTOR DUE TO THE TIGHT PRESSURE GRADIENT BETWEEN THE LOW AND A SURFACE RIDGE OVER THE W ATLC. GLOBAL MODELS SHOW THIS FEATURE TRACKING ESE AND WEAKENING OVER THE NEXT COUPLE OF DAYS AS IT CUTS OFF FROM THE PROGRESSIVE FLOW. IN THE DEEP TROPICS...STRONG WLY FLOW ALOFT ON THE N SIDE OF A BROAD UPPER-LEVEL RIDGE IS TRANSPORTING MID-HIGH LEVEL CLOUDINESS FROM THE LESSER ANTILLES TO W AFRICA. DIFFLUENCE ALOFT ON THE S SIDE OF THIS RIDGE IS ENHANCING CONVECTION WITHIN THE ITCZ E OF 20W. $$ HUFFMAN