000 AXNT20 KNHC 251800 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED FEB 25 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 WAS CENTERED ALONG 5N6W 7N12W CROSSING THE EQUATOR NEAR 19W EXTENDING TO 1.5N23W 1N42W THEN INTO NE BRAZIL NEAR THE EQUATOR ALONG 52W. SCATTERED MODERATE TO STRONG CONVECTION WAS S OF AXIS TO EQUATOR E OF 12W...AND S OF AXIS TO 5S FROM 35W-42W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION WAS WITHIN 90 NM EITHER SIDE OF AXIS FROM 18W-32W AND FROM 34W-52W. S OF 1N BETWEEN 23W-29W. SCATTERED MODERATE CONVECTION IS ALSO S OF 1N BETWEEN 36W-43W. ...DISCUSSION... GULF OF MEXICO... GENERALLY FAIR WEATHER PERSISTS TODAY ACROSS THE GULF REGION... WHERE CONFLUENCE IN WESTERLY FLOW ALOFT IS SUPPORTING SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS. HIGH PRESSURE BEHIND A RECENT COLD FRONT THAT HAS SWEPT THROUGH THE AREA WAS ALONG THE EASTERN SEABOARD...AND IS MAINTAINING A MODERATE SE TO S WIND FLOW GULF WIDE THAT HAS OPENED UP INTO THE NEXT APPROACHING FRONTAL SYSTEM MOVING INTO THE CENTRAL PLAINS TO CENTRAL TEXAS. MODEST UPPER LEVEL MOISTURE ASSOCIATED WITH A SHORT WAVE TROUGH IS STREAMING EAST SOUTHEASTWARD ACROSS PORTIONS OF THE N GULF...YIELDING SOME THIN CIRRUS CLOUDS. CARIBBEAN SEA... A DEEP LAYER TROUGH OVER THE W ATLC EXTENDING S ACROSS THE CAICOS ISLANDS TO HISPANIOLA SUPPORTS A SURFACE COLD FRONT FROM THE CENTRAL ATLANTIC THAT HAS BECOME STATIONARY ACROSS THE CAICOS ISLANDS AND INTO EASTERN CUBA AND THEN DIFFUSE INTO THE NW CARIBBEAN. A FRESH NELY FLOW OF 20-25 KT WAS DEPICTED BY A MORNING QUIKSCAT PASS TO THE N OF THIS DIFFUSE BOUNDARY. THE INDUCED LOW LEVEL CONVERGENCE WAS SUPPORTING NARROW LINES OF ISOLATED TO SCATTERED SHOWERS ACROSS THE NW CARIBBEAN N OF 18N AND ALONG THE COASTAL SLOPES OF CENTRAL AMERICA FROM BELIZE TO NICARAGUA. AN UPPER LEVEL RIDGE CONTINUES ACROSS MOST OF THE CARIBBEAN...EXTENDING FROM NE COASTAL BRAZIL NW TO NICARAGUA. THIS RIDGE HAS FLATTENED AND SHIFTED SLIGHTLY E IN THE PAST 24 HOURS...YIELDING ZONAL FLOW ALOFT ACROSS THE CARIBBEAN N OF 13N. A BROAD AREA OF LOW LEVEL MOISTURE EMBEDDED IN THE ELY TRADES HAS MOVED INTO THE CENTRAL CARIBBEAN...PRODUCING SCATTERED TO LOCALLY NUMEROUS SHOWERS AND GUSTY WINDS...WITH THE UPPER LEVEL WESTERLIES ENHANCING ISOLATED EMBEDDED TSTMS. OTHER SCATTERED PASSING TRADE WIND SHOWERS WERE SEEN MOVING ACROSS THE LESSER ANTILLES AND INTO THE BASIN E OF 64W...WITH SCATTERED SHOWERS OF DEEPER VERTICAL EXTENT SPREAD ACROSS MUCH OF THE SW CARIBBEAN. THE TRADE WINDS ARE FORECAST TO DIMINISH SLIGHTLY ACROSS MOST OF THE BASIN IN THE NEXT 24 HOURS. ATLANTIC OCEAN... THE DEEP LAYER TROUGH OVER THE W ATLC CONTINUES TO SUPPORT A SURFACE COLD FRONT THAT EXTENDS FROM THE CENTRAL ATLC...SW TO NEAR 30N 56W TO 24N 67W WHERE IT THEN HAS BECOME STATIONARY ACROSS THE CAICOS ISLANDS INTO ERN CUBA. STRONG LOW LEVEL CONVERGENCE NEAR AND BEHIND THE FRONT IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM E OF THIS FRONT...AND NUMEROUS SHOWERS WITH ISOLATED EMBEDDED TSTMS 120 TO 180 NM TO THE NW OF THE FRONT...FROM 56W TO 70W. FARTHER TO THE W AND NW OF THIS FRONT...FAIR AND VERY STABLE WEATHER CONDITIONS ARE OCCURRING...WHERE STRONG SUBSIDENCE AND BROAD A SURFACE RIDGE DOMINATE. THIS SURFACE RIDGE EXTENDS SOUTHEASTWARD TO THE FRONT FROM A 1033 MB SURFACE HIGH OVER DELMARVA. ALSO...E THROUGH SE OF THE COLD FRONT...SUBSIDENCE ASSOCIATED WITH A SURFACE RIDGE IS SUPPORTING FAIR WEATHER CONDITIONS W OF 30W AND N OF 8N. TO THE E...A DEEP LAYER LOW HAS BECOME NEARLY STATIONARY OVER THE NE ATLC OFF OF NW AFRICA...WITH AN ASSOCIATED TROUGH EXTENDING SSW TO 20N 24W AND ROTATING EWD. AS THE SURFACE IS REFLECTED A BROAD AND COMPLEX CYCLONIC CIRCULATION...WITH A LOW DIRECTLY UNDERNEATH THE UPPER LOW NEAR 32N 20W...AND AN OLD WEAKENED LOW...GENERALLY BENIGN OF WEATHER...SW OF THE CANARY ISLANDS NEAR 27N 21W. THE DEEP LOW TO THE N IS GRADUALLY BECOMING OCCLUDED...WITH MODERATE CONVECTION SPIRALING OUTWARD FROM THE W QUAD TO THE NE QUAD...WHILE A COLD FRONTAL TROUGH ASSOCIATED WITH THE SRN LOW HAS BECOME DIFFUSE TO NEAR 19N 22W. COLD STABLE AIR CONTINUES TO FUNNEL S INTO THE SUB TROPICS E OF 45W... BETWEEN THESE LOWS AND A HIGH OVER THE N CENTRAL ATLC. THESE LOWS SHOULD GRADUALLY MERGE NEAR THE SRN LOW POSITION DURING THE NEXT 24 HOURS...WEAKEN...AND THEN DRIFT E INTO NW AFRICA OVER THE NEXT FEW DAYS. ACROSS THE TROPICAL ATLC...AN UPPER RIDGE IS S OF 9N E OF 41W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS UPPER LEVEL RIDGE IS FAVORABLY ENHANCING ITCZ CONVECTION ACROSS MOST OF THE EQUATORIAL TROPICS. GOOD LOW LEVEL CONVERGENCE AND ABUNDANT TROPICAL MOISTURE PREVAIL OVER THE WARM SST'S OF THIS REGION. THIS UPPER LEVEL DIVERGENCE IS ALSO SUPPORTING SCATTERED MODERATE TO DEEP CONVECTION ASSOCIATED WITH A SURGE OF LOW LEVEL MOISTURE THAT HAS MOVED W INTO NE PORTIONS OF S AMERICA. $$ STRIPLING