000 AXNT20 KNHC 250004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 24 2014 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLC WITH AXIS EXTENDING NEAR 35W-36W. WITHIN THE LAST 24 HOURS THIS WAVE HAS BEEN MOVING WESTWARD AT 20-25 KT WHILE THE LOW LEVEL CYCLONIC CIRCULATION ASSOCIATED WITH IT HAS VANISHED. CURRENTLY...THE WAVE SIGNAL IN MODEL GUIDANCE AT 700 HPA IS VERY WEAK...HOWEVER THE GUIDANCE SHOWS THE WAVE WILL AMPLIFY BY MONDAY AND BE JUST EAST OF THE LESSER ANTILLES BY WEDNESDAY. THE WAVE CONTINUES EMBEDDED WITHIN THE ITCZ AXIS WHICH MAY BE MASKING ITS SIGNAL AT THE TIME. SCATTERED MODERATE CONVECTION IS WITHIN THE WAVE ENVIRONMENT FROM 1S-8N BETWEEN 32W-42W. A SECOND TROPICAL WAVE IS SE OF THE LESSER ANTILLES WITH AXIS NEAR 55W-56W AND MOVING WEST AT 15 KT WITHIN THE LAST 24 HOURS. MODEL GUIDANCE SHOW A CLEAR SIGNAL OF THIS WAVE AT THE 700 HPA AND INDICATES IT WILL BE MOVING ACROSS THE WINDWARD ISLANDS BY MONDAY MORNING BRINGING RAINSHOWERS TO THIS REGION. CURRENTLY...THE SSMI TPW IMAGERY SHOW THE WAVE IS EMBEDDED WITHIN VERY MOIST AIR WHICH ALONG UPPER LEVEL DIFFLUENCE IS SUPPORTING CLUSTERS OF MODERATE CONVECTION FROM 3N-10N BETWEEN 53W-58W. ISOLATED SHOWERS ARE ELSEWHERE FROM 3N-13N BETWEEN 52W- 60W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF GUINEA NEAR 9N13W AND THEN INTO THE TROPICAL EASTERN ATLC ALONG 7N15W TO 5N18W. THE ITCZ AXIS BEGINS NEAR 5N18W AND CONTINUES ALONG 1N27W TO EAST OF A TROPICAL WAVE NEAR 1N35W. IT RESUMES WEST OF THE TROPICAL WAVE NEAR 1N37W TO 2N45W TO 4N51W. SMALL CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 1S-6N E OF 30W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 1S-8N W OF 30W. ...DISCUSSION... GULF OF MEXICO... MIDDLE TO UPPER LEVEL RIDGING REMAINS ACROSS THE GULF AND CONTINUE TO SUPPORT A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH NEAR 29N88W. THIS IS MAINTAINING ANTICYCLONIC WIND FLOW OF 5-15 KT ACROSS THE GULF. SSMI TPW IMAGERY SHOW VERY MOIST AIR IN THE FAR WESTERN BASIN BEING ADVECTED FROM THE NW CARIBBEAN BASIN WHILE DRY AIR DOMINATES ELSEWHERE. ALOFT...WATER VAPOR IMAGERY SHOW A SWATH OF MOIST AIR ACROSS THE GULF BEING ADVECTED FROM THE EPAC BY SW WIND FLOW. HOWEVER...STRONG DEEP LAYER WIND SHEAR ACROSS THE BASIN IS SUPPORTING FAIR WEATHER. THE HIGH PRESSURE CENTER IS FORECAST TO DISSIPATE BY SUNDAY NIGHT. HOWEVER...A BROAD AREA OF HIGH PRESSURE COMING OFF THE CAROLINAS COAST THE SAME DAY WILL SUPPORT RIDGING AND RETURN FLOW ACROSS THE BASIN THROUGH TUESDAY NIGHT. OTHERWISE...A FRONTAL SYSTEM CURRENTLY ACROSS GEORGIA IS EXPECTED TO REACH THE NORTHERN FLORIDA PENINSULA AND NE GULF ADJACENT WATERS BY SUNDAY MORNING ENHANCING RAINSHOWERS THROUGH THE NIGHT. CARIBBEAN SEA... A DEEP LAYER TROUGH DOMINATES ACROSS THE CARIBBEAN WATERS WHICH IS SUPPORTING A SURFACE TROUGH ANALYZED FROM EASTERN CUBA NEAR 20N76W TO SOUTHERN ADJACENT WATERS OF JAMAICA NEAR 16N78W. WITH MODERATE MOISTURE MAINLY ACROSS THE NW CARIBBEAN AND THE TROUGH ALOFT SUPPORTING LIFTING...SCATTERED SHOWERS AND TSTMS ARE BEING ENHANCED ACROSS CUBA AND JAMAICA WHILE ISOLATED SHOWERS AND TSTMS AFFECT HISPANIOLA. PASSING SCATTERED SHOWERS ARE POSSIBLE FOR PUERTO RICO AND ADJACENT WATERS TONIGHT. ISOLATED SHOWERS AND TSTMS ASSOCIATED WITH THE MONSOON TROUGH ARE NOTED IN THE SW BASIN S OF 11N BETWEEN 76W-82W. ELSEWHERE...DEEP LAYER DRY AIR SUPPORTS FAIR WEATHER. THE AZORES HIGH EXTENDS A RIDGE SW TO THE NORTHERN BASIN WHICH IS TIGHTENING THE PRESSURE GRADIENT TO SUPPORT TRADES OF 20-25 KT ACROSS THE CENTRAL CARIBBEAN S OF 17N. A MORE RELAXED PRESSURE GRADIENT ELSEWHERE SUPPORT TRADES OF 15 KT. A TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE WINDWARD ISLANDS BY MONDAY MORNING ENHANCING SHOWERS IN THIS REGION. ...HISPANIOLA... THE SURFACE TROUGH THAT WAS MOVING ACROSS THE ISLAND EARLIER THIS MORNING IS NOW ACROSS EASTERN CUBA AND JAMAICA...HOWEVER A DEEP LAYER TROUGH ACROSS THE CARIBBEAN AND THE AVAILABILITY OF MODERATE MOISTURE ACROSS THE ISLAND IS SUPPORTING SCATTERED SHOWERS WITH ISOLATED TSTMS NOTED OVER THE NORTH-CENTRAL ISLAND. THIS ACTIVITY WILL REDUCE OVER THE REMAINDER WEEKEND AS A DRY AIRMASS OVER THE EASTERN CARIBBEAN MOVES ACROSS THE REGION. ATLANTIC OCEAN... A DEEP LAYER TROUGH COVERS THE WESTERN ATLC WHICH IS SUPPORTING A FRONTAL SYSTEM N OF THE AREA. A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL ENTER THE SW N ATLC BY SUNDAY MORNING AND WILL KEEP MOVING SLOWLY ACROSS THE REGION THROUGH TUESDAY MORNING. A BROAD UPPER LEVEL RIDGE THAT COVERS THE CENTRAL AND PARTS OF THE EASTERN ATLC IS GENERATING DIFFLUENCE ALOFT TO SUPPORT SCATTERED SHOWERS AND TSTMS N OF 26N BETWEEN 58W-63W AND ISOLATED SHOWERS NE OF PUERTO RICO. OTHERWISE...EXCEPT FOR THE TROPICAL WAVES DISCUSSED ABOVE...SURFACE RIDGING AND FAIR WEATHER DOMINATE ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR