000 AXNT20 KNHC 251117 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 6N9W 2N17W CROSSING THE EQUATOR NEAR 21W EXTENDING TO 2S32W INTO NE BRAZIL NEAR 3S43W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS S OF 6N BETWEEN 6W-21W. SCATTERED MODERATE CONVECTION IS S OF 1N BETWEEN 23W-29W. SCATTERED MODERATE CONVECTION IS ALSO S OF 1N BETWEEN 36W-43W. ...DISCUSSION... GULF OF MEXICO... GENERALLY FAIR WEATHER IS PRESENT ACROSS MUCH OF THE GULF REGION...WHERE CONFLUENCE IN WESTERLY FLOW ALOFT IS SUPPORTING ATMOSPHERIC SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS. THE SUBSIDENCE IS ALSO BEING SUPPORTED BY A SURFACE RIDGE OVER THE GULF...WITH A 1020 MB SURFACE HIGH OVER E MEXICO NEAR 23N90W. ACROSS THE NW GULF...SE TO S SURFACE WINDS ARE PRESENT AROUND THE SURFACE RIDGE. DEEP LAYER DRY AIR IS ALSO PRESENT ACROSS MUCH OF THE GULF REGION. HOWEVER...UPPER LEVEL MOISTURE IS STREAMING SOUTHEASTWARD ACROSS PORTIONS OF THE N GULF. CARIBBEAN SEA... A DEEP LAYER TROUGH OVER THE W ATLC IS ASSOCIATED WITH A SURFACE COLD FRONT IN THE NW CARIBBEAN THAT EXTENDS FROM NE OF JAMAICA NEAR 19N76W TO E OF CUBA NEAR 20N74W TO THE SW NORTH ATLC. LOW LEVEL CONVERGENCE IS SUPPORTING ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THIS FRONT. TRADE WINDS ARE FORECAST TO DIMINISH OVER MUCH OF THE CARIBBEAN SEA THROUGH SUNDAY. GENERALLY FAIR WEATHER CONDITIONS ARE OCCURRING ACROSS MUCH OF THE CARIBBEAN REGION...WHERE A BROAD UPPER LEVEL RIDGE IS PRESENT. PATCHES OF LOW LEVEL MOISTURE CONTINUE TO BE ADVECTED WESTWARD ACROSS THE CARIBBEAN BY THE TRADE WINDS...WITH SCATTERED SHOWERS EMBEDDED WITHIN THESE PATCHES OF LOW LEVEL MOISTURE. THE GREATEST CONCENTRATION OF THESE SHOWERS IS FROM 13N-15N BETWEEN 62W-69W. ATLANTIC OCEAN... THE DEEP LAYER TROUGH OVER THE W ATLC IS ASSOCIATED WITH A SURFACE COLD FRONT THAT EXTENDS FROM THE NW CARIBBEAN TO E OF CUBA NEAR 20N74W TO 25N65W TO 32N53W TO NE OF THE DISCUSSION AREA. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THIS FRONT. TO THE W OF THIS FRONT...FAIR WEATHER CONDITIONS ARE OCCURRING...WHERE SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS ARE PRESENT IN THE VICINITY OF A SURFACE RIDGE. THIS SURFACE RIDGE EXTENDS SOUTHEASTWARD FROM A 1032 MB SURFACE HIGH OVER NE NORTH CAROLINA NEAR 37N76W. ALSO...ACROSS LOCATIONS IN THE CENTRAL AND E ATLC THAT ARE SE OF THE COLD FRONT...SUBSIDENCE ASSOCIATED WITH A SURFACE RIDGE IS SUPPORTING FAIR WEATHER CONDITIONS. HOWEVER...A DEEP LAYER TROUGH IS PRESENT OVER THE E ATLC N OF 22N E OF 30W WITH AN UPPER LOW NEAR 31N19W. THE DEEP LAYER TROUGH AND UPPER LOW ARE ASSOCIATED WITH A DISSIPATING SURFACE COLD FRONT THAT EXTENDS FROM 20N29W TO 22N21W TO 25N19W TO A 1010 MB SURFACE LOW W OF THE CANARY ISLANDS NEAR 28N21W. THIS SURFACE LOW IS FORECAST TO REMAIN NEARLY STATIONARY DURING THE NEXT DAY. ALSO...A 1009 MB SURFACE LOW IS PRESENT NEAR 32N19W. THIS SURFACE LOW IS FORECAST TO MOVE SOUTHWESTWARD DURING THE NEXT DAY AND MERGE WITH THE AFOREMENTIONED 1010 MB SURFACE LOW W OF THE CANARY ISLANDS NEAR 28N21W...RESULTING IN A 1010 MB SURFACE LOW NEAR 28N21W AT 26/0600 UTC. LOW LEVEL CONVERGENCE AND ATMOSPHERIC INSTABILITY IN THE VICINITY OF THE SURFACE LOWS AND DISSIPATING SURFACE COLD FRONT ARE SUPPORTING SCATTERED SHOWERS N OF 24N BETWEEN 12W-23W. ACROSS THE TROPICAL ATLC...AN UPPER RIDGE IS S OF 9N E OF 41W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS UPPER LEVEL RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ. THIS UPPER LEVEL DIVERGENCE IS ALSO SUPPORTING SCATTERED SHOWERS FROM 2N-5N BETWEEN 40W-49W. $$ COHEN