000 AXNT20 KNHC 031127 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SAT MAR 03 2007 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N10W 4N20W 1N30W CROSSING THE EQUATOR AT 37W INTO NE BRAZIL NEAR 3S50W. WIDELY SCATTERED MODERATE CONVECTION SOUTH OF 4N WEST OF 27W...EXTENDING TO THE BRAZILIAN COAST. ...DISCUSSION... GULF OF MEXICO... A LARGE MID/UPPER CUT-OFF LOW OVER THE GREAT LAKES IS PRODUCING A BROAD SWATH OF CYCLONIC FLOW ACROSS A MAJORITY OF THE CONTINENTAL US...WHICH IS CAUSING NEARLY ZONAL FLOW ACROSS THE GULF OF MEXICO. VERY STRONG SUBTROPICAL JETSTREAM WITH 250 MB WINDS INDICATING CORE SPEEDS OF 130-150 KT LIES ALONG THE NORTH GULF STATES. THE FRONTAL BOUNDARY ASSOCIATED WITH THIS SYSTEM HAS BEGUN TO SLOWLY MOVES ACROSS N-CENTRAL FLORIDA WHILE REMAINS NEARLY STATIONARY OVER THE GULF ALONG 26N86W...WHERE THERE IS A 1009 MB SFC LOW TO ANOTHER 1007 MB SFC LOW LOCATED NEAR 20N91W. REGIONAL RADAR MOSAICS IS INDICATING A BAND OF SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE NE GULF AND N-CENTRAL FLORIDA. AT 09Z...A REINFORCING COLD FRONT IS ENTERING THE NW PORTION OF THE GULF FOLLOWED BY A STRONG HIGH PRES SYSTEM AND A SURGE OF COLD AIR. A SHORTWAVE TROUGH CURRENTLY OVER NEW MEXICO WILL MOVE TOWARDS TEXAS...GIVING THE FRONTAL BOUNDARY OVER THE GULF AND THE FLORIDA PENINSULA A SECOND PUSH. THE FRONT IS EXPECTED TO MOVE ACROSS SOUTH FLORIDA THIS EVENING AND SE OF THE GULF WATERS BY SUN AFTERNOON WITH AN INCREASE IN WINDS AND SEAS. GALE FORCE WINDS ARE EXPECTED OVER THE SW GULF SAT NIGHT INTO SUN. CARIBBEAN... A MID-LEVEL HIGH IS CENTERED OVER THE NW CARIBBEAN WITH AN ASSOCIATED RIDGE AXIS ALONG 18N/19N. THIS FEATURE EXPANDS ACROSS THE GREATER ANTILLES TO SOUTH MEXICO AND THE YUCATAN PENINSULA. IN ADDITION...THERE IS AN UPPER LEVEL TROUGH/SHEAR AXIS EXTENDING FROM THE LEEWARD ISLANDS SW TO JUST OFF THE COAST OF COLOMBIA... THEN SW ACROSS COSTA RICA. BOTH OF THESE FEATURES ARE PRODUCING MODERATE/STRONG SUBSIDENCE OVER THE BASIN. SCATTERED TRADE WIND SHOWERS ARE SEEN ACROSS THE REGION EXTENDING NW TOWARDS PUERTO RICO/VIRGIN ISLANDS...THE MONA PASSAGE AND HISPANIOLA. THE SAN JUAN DOPPLER RADAR IS SHOWING SCATTERED SHOWERS OVER THESE ISLANDS AND THE REGIONAL COASTAL WATERS. A PATCH OF BROKEN TO OVERCAST LOW/MID CLOUDS IS OVER THE SW CARIBBEAN MOVING WWD TOWARDS THE CARIBBEAN PLAINS OF COSTA RICA AND NICARAGUA. ATLANTIC... A COLD FRONT EXTENDS FROM 32N75W TO THE FLORIDA COAST NEAR TITUSVILLE WITH SCATTERED SHOWERS/ISOLATED TSTMS EXTENDING UP TO 140 NM N OF THE FRONTAL BOUNDARY. UPPER DIFFLUENCE IS SUPPORTING THIS CONVECTIVE ACTIVITY. AN UPPER RIDGE COVERS THE W ATLC...WITH HIGH CLOUDS SPILLING EWD FROM FLORIDA TO BEYOND 60W. FARTHER DOWNSTREAM...MID/UPPER TROUGH EXTENDS FROM 31N35W TO THE LEEWARD ISLANDS CONTINUING ACROSS THE CARIBBEAN. A WEAKENING STATIONARY FRONT LIES ALONG 30N40W 28N50W 28N58W. TO THE S...A SURFACE TROUGH IS EMBEDDED WITHIN THE TRADES ALONG 54W FROM 14N TO 21N...MAINLY AS A PRESSURE PERTURBATION BUT ALSO SHOWING SOME SIGNS OF SLIGHT TURNING IN THE CUMULUS FIELD. OVER THE E ATLC...A SURFACE RIDGE DOMINATES THE AREA WITH A 1026 MB HIGH CENTERED NE OF THE MADEIRA ISLANDS WITH THE AXIS STRETCHING SW TO 27N35W. AT THE UPPER LEVELS...A RIDGE AXIS EXTENDS FROM 14N35W IN THE TROPICS NE TO THE MADEIRA ISLANDS... THEN EWD INTO NORTHERN MOROCCO. THERE APPEARS TO BE AN EMBEDDED CYCLONIC CIRCULATION NEAR THE CANARY ISLANDS. THERE IS VERY LITTLE MOISTURE TO WORK WITH NO SIGNIFICANT PRECIPITATION FALLING ACROSS W AFRICA OR THE E ATLC WATERS. $$ GR