000 AXNT20 KNHC 141737 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAR 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 5N10W 2N14W 1N39W CROSSING THE EQUATOR NEAR 47W TO 1S51W. ITCZ IS FAIRLY ACTIVE WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 120 NM EITHER SIDE OF THE AXIS AND WITHIN 180 NM N OF THE AXIS W OF 33W. ISOLATED MODERATE IS WITHIN 120 NM N OF THE AXIS BETWEEN 20W-30W. ...DISCUSSION... GULF OF MEXICO... A STRONG SLOW MOVING CUT OFF LOW IS LOCATED OVER NE TEXAS. SWIFT MID AND UPPER LEVEL SWLY WINDS AND DIFFLUENCE ALOFT ALONG WITH LOW-LEVEL MOIST SE RETURN FLOW ARE FUELING SCATTERED TO NUMEROUS TSTMS MAINLY ALONG THE NRN GULF COAST W OF 87W...SOME OF THESE STORMS MAY BE SEVERE. A SUBTROPICAL JET ORIGINATES ON THE S SIDE OF THE UPPER LOW AND EXTENDS ACROSS FLORIDA AND INTO THE SW ATLC. THIS JET IS TRANSPORTING/GENERATING A FAIR AMOUNT OF MOSTLY HIGH LEVEL MOISTURE ACROSS THE GULF E OF 90W. ABUNDANT DRY AIR ALOFT LIES W OF THE MOISTURE PLUME SLOWLY ERODING THE WRN SIDE. THIS DRY AIR WILL CONTINUE TO PUSH E STABILIZING THE SRN HALF OF THE GULF. AT THE SFC...THE MAIN WEATHER FEATURE IS AN WRN ATLC RIDGE THAT EXTENDS SW INTO THE ERN HALF OF THE REGION. E-SE WINDS...MAINLY IN THE 10-20 KT RANGE...COVER MOST OF THE AREA. OVER THE NEXT COUPLE OF DAYS...THE UPPER LOW WILL MOVE ESE AND WEAKEN. NWP MODELS SHOW AN ASSOCIATED SFC TROUGH PULLING E WITH IT TARGETING A CHANCE OF SHOWERS AND POSSIBLE TSTMS ALONG IT. CARIBBEAN... THE WRN PORTION OF THE CARIB IS DOMINATED BY WLY UPPER LEVEL FLOW ON THE NRN PERIPHERY OF AN UPPER HIGH CENTERED OVER COSTA RICA. THE UPPER PATTERN THEN FOLDS INTO A TROUGH ACROSS THE CENTRAL AND ERN CARIB WITH THE AXIS RUNNING FROM PUERTO RICO TO VENEZUELA AND COLOMBIA. CONFLUENCE ALOFT BETWEEN THESE FEATURES IS ENHANCING VERY DRY AIR/STABILITY S OF 15N W OF 70W. MODESTLY DRY AIR ALOFT COVERS THE REMAINDER OF THE BASIN. IN THE LOWER LEVELS...STRONG SFC HIGH PRES LOCATED N OF THE REGION IS PRODUCING MODERATE TO FRESH NE-ELY TRADES. THESE WINDS ARE DRIVING PATCHES OF SHALLOW MOISTURE ACROSS THE SEA. THE CLOUDS ARE THICKEST N OF 15N E OF 73W...ESPECIALLY OVER THE NRN LEEWARD ISLANDS WHERE LOW-LEVEL CONVERGENCE IS NOTED NEAR THE TAIL END OF A SLOW MOVING CENTRAL ATLC TROUGH. SAN JUAN DOPPLER RADAR IS DETECTING ISOLATED SHOWERS MOVING NE-SW ACROSS THE ISLAND SO SCATTERED SHOWERS ARE LIKELY FURTHER E AND S WHERE VIS IMAGES DETECT MORE ORGANIZED CLOUD COVER. OVER THE NEXT COUPLE OF DAYS...THE STRONG SFC RIDGE AND TROUGH WILL SHIFT SLIGHTLY TO THE E. THIS WILL ALLOW THE TRADE WINDS TO BECOME MORE UNIFORM ELY AND SLACKEN. THIS WILL ALSO REDUCE THE FETCH OF MOISTURE ACROSS THE ERN CARIB. WESTERN ATLANTIC... A MID AND UPPER LEVEL RIDGE/TROUGH PATTERN COVERS THE ATLC W OF 45W. THE MID/UPPER LEVEL RIDGE IS ALIGNED FAIRLY N-S ALONG 76W. A PLUME OF HIGH LEVEL CLOUDS ARE STREAMING INTO THE SW ATLC BY STRONG SW-WLY WINDS ALONG AND TO THE W OF THE RIDGE AXIS...CURRENTLY CONTAINED W OF 74W/75W. THIS UPPER MOISTURE QUICKLY DRIES OUT E OF 74W AS THE MID/UPPER LEVEL FLOW VEERS NWLY IN RESPONSE TO AN UPPER LEVEL LOW SEVERAL HUNDRED NM E OF BERMUDA NEAR 36N57W...WHICH HAS AN ASSOCIATED SFC REFLECTION. WIDESPREAD DRY STABLE AIR IS NOTED ON WV IMAGES BETWEEN 54W-72W. THE MOST UNSETTLED WEATHER IN THE ATLC HAS TO DO WITH THE VERTICALLY STACKED LOW PRES SYSTEM E OF BERMUDA. THE SFC ANALYSIS SHOWS A 1012 MB LOW LOCATED NEAR 32N50W WITH A COLD FRONT EXTENDING SW TO 20N57W. A SFC TROUGH...LACKING MUCH THERMAL GRADIENT...CONTINUES SW FROM THERE ACROSS THE NRN LEEWARD ISLANDS. SCATTERED SHOWERS AND TSTMS ARE WITHIN 240 NM AHEAD OF THE FRONT N OF 25N AND ISOLATED TO SCATTERED SHOWERS S OF THERE. LOOKING AHEAD A DAY OR TWO...THE FRONT WILL MOVE VERY SLOWLY AND BECOME STRETCHED. THEREAFTER IT WILL LIKELY BEGIN WEAKENING AS ITS UPPER SUPPORT PULLS AWAY. EASTERN ATLANTIC... A DEEP LAYER RIDGE COVERS THE MAJORITY OF THE ATLC E OF 45W. THE UPPER LEVEL PART OF THIS RIDGE RUNS ALONG 21N43W TO BEYOND 32N37W. DEBRIS MOISTURE FROM THE STRONG FRONT IN THE ATLC IS STREAMING AROUND THE RIDGE W OF 33W. THIS UPPER MOISTURE QUICKLY DRIES OUT E OF 33W AS THE MID/UPPER LEVEL FLOW VEERS NWLY IN RESPONSE TO A NEARLY STATIONARY SMALL STACKED LOW OVER THE CANARY ISLANDS...ANALYZED 1010 MB AT THE SFC. SCATTERED SHOWERS ARE MAINLY WITHIN 180 NM N AND E OF THE SFC LOW. THE PRES GRAD BETWEEN THIS LOW AND A STRONG HIGH N OF THE AZORES IS GENERATING STRONG WINDS N OF 25N BETWEEN 18W-27W. IN THE DEEP TROPICS...AN UPPER LEVEL JET BRANCH ORIGINATED NEAR 10N35W AND RUNS NE TO AFRICA ACROSS THE CAPE VERDE ISLANDS. PLENTY OF MOISTURE LIES TO THE E OF THE JET AXIS WHILE UPPER CONFLUENT FLOW IS ENHANCING STABILITY W OF THE AXIS. THIS IS PROVIDING A FAVORABLE ENVIRONMENT FOR CONVECTION IN THE ITCZ. OVER THE NEXT COUPLE OF DAYS...THE WEAK LOW OVER THE CANARY ISLANDS WILL DISSIPATE AS SFC HIGH PRES REMAINS IN PLACE. $$ CANGIALOSI/MARCINIAK