000 AXNT20 KNHC 170524 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI JUL 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 18N29W TO 13N32W TO 7N32W MOVING W NEAR 10 KT. THIS WAVE HAS BEEN MOVED E OF ITS 16/1800 UTC SURFACE ANALYSIS POSITION TO COINCIDE WITH A LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION BASED ON RECENT SATELLITE IMAGERY. THE QUIKSCAT PASS AROUND 16/2045 UTC INDICATED CYCLONIC CURVATURE IN THE FLOW NEAR THE SURFACE IN THE VICINITY OF THIS WAVE. SCATTERED MODERATE CONVECTION IS FROM 8N-15N BETWEEN 30W-33W. A TROPICAL WAVE IS ALONG 50W/51W S OF 17N MOVING W NEAR 15 KT. THIS WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. RECENT SATELLITE IMAGERY INDICATES THAT THIS WAVE COINCIDES WITH AN INVERTED-V PATTERN IN THE COVERAGE OF LOW LEVEL CLOUDS. THE PRESENCE OF DRY LOW/MID-LEVEL SAHARAN AIR IS LIMITING DEEP CONVECTION NEAR THIS WAVE. HOWEVER...SCATTERED MODERATE CONVECTION IS FROM 12N-14N BETWEEN 47W-53W A TROPICAL WAVE EXTENDS FROM S OF FLORIDA NEAR 25N80W TO W CUBA NEAR 23N83W TO THE COAST OF HONDURAS NEAR 16N87W INTO THE E PACIFIC REGION NEAR 4N89W MOVING W NEAR 25 KT. THIS WAVE IS ASSOCIATED WITH A DISTINCT AND NARROW MAXIMUM IN TOTAL PRECIPITABLE WATER. THE WAVE IS LEADING AN AREA OF ABUNDANT DRY LOW/MID-LEVEL SAHARAN AIR ACROSS MUCH OF THE CENTRAL AND E CARIBBEAN. THE DRY AIR...ALONG WITH STABLE ATMOSPHERIC CONDITIONS BENEATH AN UPPER LEVEL RIDGE OVER THE CENTRAL AND E CARIBBEAN...ARE LIMITING THE AREAL COVERAGE OF DEEP CONVECTION NEAR THE WAVE. HOWEVER...SCATTERED MODERATE CONVECTION IS OVER THE W CARIBBEAN S OF 18N W OF 85W INCLUDING PORTIONS OF THE GULF OF HONDURAS. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 14N17W 11N28W 10N39W 10N48W 10N62W. SCATTERED MODERATE CONVECTION IS FROM 9N-13N BETWEEN 22W-25W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE IS PRESENT ACROSS THE N GULF...WITH A SURFACE RIDGE ACROSS THE CENTRAL GULF AND A 1018 MB SURFACE HIGH NEAR 27N84W. STABLE ATMOSPHERIC CONDITIONS AND SUBSIDENCE ASSOCIATED WITH THE SURFACE HIGH AND SURFACE RIDGE ARE RESULTING IN GENERALLY FAIR WEATHER ACROSS THE GULF. ANTICYCLONIC FLOW AROUND THE SURFACE RIDGE IS SUPPORTING A BROAD SWATH OF E TO SE WINDS OF 10-15 KT ACROSS A LARGE PART OF S GULF. A WEAK FRONT IS EXPECTED TO PUSH INTO THE FAR NE GULF DURING THE WEEKEND...AND THEN BECOME DIFFUSE OVER N FLORIDA ON MONDAY. THE FRONT IS FORECAST TO BE PRECEDED BY A BRIEF PERIOD OF INCREASING SW WINDS. CARIBBEAN SEA... FRESH TO STRONG TRADE WINDS ARE OCCURRING BETWEEN THE SUBTROPICAL RIDGE OVER THE CENTRAL ATLC AND A BROAD TROUGH OVER NORTHERN SOUTH AMERICA...WITH THE STRONGEST FLOW NEAR THE COAST OF COLOMBIA. RECENT SCATTEROMETER DATA INDICATE THAT A LARGE AREA OF NE TO E WINDS OF 20 TO 30 KT IS PRESENT ACROSS THE S CARIBBEAN. THESE TRADE WINDS ARE FORECAST TO REMAIN FRESH TO STRONG INTO THIS WEEKEND AS THE SUBTROPICAL RIDGE REMAINS IN PLACE. COMPUTER MODEL GUIDANCE INDICATES THAT STRONGER WINDS TO GALE FORCE ARE OCCURRING NEAR THE COAST OF COLOMBIA...WHERE WINDS ARE BEING ENHANCED DUE TO LOCAL TOPOGRAPHICAL VARIATIONS NEAR THE COAST OF COLOMBIA. GALE CONDITIONS ARE FORECAST TO CONTINUE THROUGH THIS MORNING NEAR THE COAST OF COLOMBIA. ACROSS MUCH OF THE CENTRAL AND E CARIBBEAN...DEEP LAYER DRY AIR AND STABLE ATMOSPHERIC CONDITIONS ARE RESULTING IN GENERALLY FAIR WEATHER. ATLANTIC OCEAN... DEEP LAYER MOISTURE IS COMBINING WITH UPPER LEVEL DIFFLUENCE IN NORTHWESTERLY FLOW ALOFT TO RESULT IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 27N BETWEEN 56W-67W. SUBSIDENCE AND GENERALLY FAIR WEATHER ARE PRESENT ACROSS MUCH OF THE CENTRAL AND E ATLC AROUND A BROAD SURFACE RIDGE ASSOCIATED WITH A 1036 MB HIGH NEAR 41N25W. ACROSS THE TROPICAL N ATLC...AN UPPER LEVEL RIDGE EXTENDS FROM 18N16W TO AN UPPER LEVEL HIGH NEAR 16N42W TO 15N59W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL HIGH AND THE UPPER LEVEL RIDGE IS SUPPORTING THE CONVECTION ASSOCIATED NEAR THE ITCZ AND ALONG THE TROPICAL WAVE EXTENDING FROM 18N29W TO 13N32W TO 7N32W. $$ COHEN