000 AXNT20 KNHC 210604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN JUL 21 2013 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0539 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS FROM 19N49W TO 09N51W MOVING W-NW NEAR 10 KT. THE WAVE IS EMBEDDED WITHIN A MODERATE MOIST ENVIRONMENT AS DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY. THE METEOSAT-9 SAL TRACKING PRODUCT IS SHOWING SOME DRY AIR SPREADING OVER THE WAVE ENVIRONMENT WHICH IS HINDERING CONVECTION. TROPICAL WAVE MOVING ACROSS CENTRAL AMERICA WITH AXIS EXTENDING FROM 17N86W IN THE WESTERN CARIBBEAN TO 09N86W IN THE EAST PACIFIC. ITS AXIS IS MOVING NEAR 5 KT AND IS MOSTLY EMBEDDED IN A MODERATE MOIST ENVIRONMENT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OCCURRING OVER NICARAGUA...WESTERN HONDURAS...EASTERN GUATEMALA AND EL SALVADOR WITH ISOLATED SHOWERS EXTENDING OVER THE W CARIBBEAN W OF 84W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 16N16W AND CONTINUES ALONG 09N25W TO 04N38W. THE ITCZ AXIS EXTENDS FROM 04N39W TO 03N46W 03N53W. CLUSTERS OF MODERATE CONVECTION WITH EMBEDDED THUNDERSTORMS ARE FROM 08N-16N E OF 20W. ISOLATED MODERATE CONVECTION IS WITHIN 170 NM EITHER SIDE OF THE AXES BETWEEN 20W AND 48W. ...DISCUSSION... GULF OF MEXICO... A MODERATE MOIST ENVIRONMENT IS ACROSS THE BASIN IN THE MIDDLE AND LOWER LEVELS AS DEPICTED IN TOTAL PRECIPITABLE WATER AND WATER VAPOR IMAGERY. S-SE WIND FLOW IN THE RANGE OF 5-15 KT COVERS MOST OF THE GULF THIS EVENING. IN THE UPPER LEVELS...A LOW OVER NE LOUISIANA EXTENDS A TROUGH TO THE BAY OF CAMPECHE AND SOUTHERN MEXICO WHICH IS SUPPORTING A 1011 MB LOW NEAR THE CHIVELA PASS MEXICO. CLUSTERS OF MODERATE CONVECTION WITH EMBEDDED THUNDERSTORMS ARE OVER INLAND SOUTHERN MEXICO AND EXTEND TO THE BAY OF CAMPECHE S OF 20N. OVER THE NE GULF...N OF 28N E OF 89W WINDS FROM THE SW ARE BANKING LOW LEVELS CLOUDS TO NORTHERN FLORIDA. MIDDLE LEVEL DIFFLUENCE OVER THIS REGION IS SUPPORTING A CLUSTER OF MODERATE CONVECTION N OF 28N E OF 85W. SURFACE RIDGING AND RETURN FLOW WILL PREVAIL ACROSS THE GULF DURING THE NEXT 48 HOURS. FAIR WEATHER IS EXPECTED FOR THE MOST PART DURING THIS TIME BEING SUPPORTED BY DRY AIR ADVECTION FROM THE WESTERN CARIBBEAN. CARIBBEAN SEA... EXCEPT FOR THE FAR WESTERN CARIBBEAN W OF 85W AND THE SOUTHERN CARIBBEAN S OF 13N...DRY AIR SPREADS ACROSS THE BASIN IN THE MIDDLE AND LOWER LEVELS AS DEPICTED IN TOTAL PRECIPITABLE WATER AND WATER VAPOR IMAGERY WHICH IS SUPPORTING FAIR WEATHER. THE AXIS OF A TROPICAL WAVE EXTENDS FROM 17N86W IN THE WESTERN CARIBBEAN TO 09N86W IN THE EAST PACIFIC. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OCCURRING OVER NICARAGUA...WESTERN HONDURAS...EASTERN GUATEMALA AND EL SALVADOR WITH ISOLATED SHOWERS EXTENDING OVER THE W CARIBBEAN W OF 84W. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION WITH EMBEDDED THUNDERSTORMS ARE OVER THE SOUTHERN CARIBBEAN S OF 11N ASSOCIATED WITH THE MONSOON TROUGH WHICH AXIS MOVES ACROSS COSTA RICA AND PANAMA. ALSO IN THE SOUTHERN CARIBBEAN...CONVECTION ASSOCIATED WITH THE TROPICAL WAVE CROSSING CENTRAL AMERICA EXTENDS WITHIN 140 NM OF THE COAST OF NICARAGUA. SCATTERED SHOWERS EXTENDS WITHIN 70 NM N OF THE COASTS OF COLOMBIA AND VENEZUELA BETWEEN 69W-73W ASSOCIATED WITH A 1008 MB LOW OVER INLAND N COLOMBIA. OTHERWISE...A TIGHT PRESSURE GRADIENT OVER THE CENTRAL CARIBBEAN HAS PRODUCED GALE FORCE WINDS FROM 12N TO 14N BETWEEN 73W AND 76W THAT ARE EXPECTED TO SUBSIDE SUNDAY AFTERNOON. TRADEWINDS OF 15-20 KT ARE OVER THE REST OF THE BASIN. FAIR WEATHER IS EXPECTED OVER MOST OF THE CARIBBEAN UNTIL LATE SUNDAY WHEN CONDITIONS START TO DEGRADE AS A TROPICAL WAVE ENTERS THE EASTERN CARIBBEAN. THE WAVE IS EXPECTED TO MOVE ACROSS PUERTO RICO MONDAY AFTERNOON AND OVER THE HISPANIOLA ON EARLY ON TUESDAY. HISPANIOLA... DRY AIR IS ACROSS LA HISPANIOLA THIS EVENING LIMITING ANY CONVECTIVE ACTIVITY. AFTERNOON/EARLY EVENING RAINSHOWERS ASSOCIATED WITH DIURNAL SURFACE HEATING AND ENHANCED BY AN UPPER LEVEL LOW EXTENDING A TROUGH TO THE ISLAND CAN BE EXPECTED ON SUNDAY. WEATHER CONDITIONS IMPROVE FOR MOST OF THE DAY ON MONDAY AS A DRY AIR MASS MOVES ACROSS THE ISLAND BUT START TO DETERIORATE AGAIN AT NIGHT AS THE TROPICAL WAVE MOVES WESTWARD ACROSS PUERTO RICO. THE TROPICAL WAVE IS EXPECTED TO ENTER THE DOMINICAN REPUBLIC EARLY TUESDAY AND RAINSHOWERS ARE EXPECTED. ATLANTIC OCEAN... MODERATE MOISTURE AND MIDDLE LEVELS DIVERGENCE IS OVER THE WESTER ATLC ENHANCING SCATTERED MODERATE CONVECTION N OF THE BAHAMAS W OF 75W. SURFACE RIDGING IS ACROSS THE REMAINDER BASIN ANCHORED BY A 1023 MB HIGH NEAR 28N64W AND A 1023 MB HIGH NEAR 28N35W. BESIDES THE REGIONS FORMERLY MENTIONED...FAIR WEATHER IS ACROSS THE ATLC SUPPORTED BY DRY AIR AT THE LOWER LEVELS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS