000 AXNT20 KNHC 280603 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 28 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE EASTERN ATLC WITH AXIS EXTENDING FROM 21N28W TO A 1013 MB LOW NEAR 10N26W AND MOVING W AT 20 KT. NO CONVECTION IS ASSOCIATED WITH THE WAVE AS SAHARAN DRY AIR AND DUST CONTINUE IN THE ENVIRONMENT OF THE WAVE. A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM 20N39W TO 10N37W AND MOVES W AT 20 KT. NO CONVECTION IS ASSOCIATED WITH THE WAVE AS SAHARAN DRY AIR AND DUST CONTINUE IN THE ENVIRONMENT OF THE WAVE. A TROPICAL WAVE IS ON THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 19N60W TO 10N64W...MOVING W AT 20 KT. DEEP LAYER MOISTURE ACCOMPANIES THIS WAVE S OF 17N WHICH ALONG WITH UPPER-LEVEL DIVERGENCE SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS FROM 9N-16N EAST OF 68W. A TROPICAL WAVE IS ON THE WESTERN CARIBBEAN WITH AXIS EXTENDING FROM 22N77W TO 9N81W...MOVING WEST AT 20-25 KT. AN UPPER LEVEL INVERTED TROUGH SUPPORTS THIS WAVE THAT IS ASSOCIATED WITH DEEP LAYER MOISTURE. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE N OF 17N BETWEEN 76W-83W. ISOLATED SHOWERS ARE ELSEWHERE S OF 17N. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N16W AND CONTINUES ALONG 8N23W TO 9N33W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS FROM 8N-15N BETWEEN 19W-22W. ...DISCUSSION... GULF OF MEXICO... SURFACE LOW PRESSURE DOMINATES ACROSS THE WESTERN GULF BEING SUPPORTED BY A MIDDLE LEVEL ELONGATED CYCLONIC CIRCULATION ACROSS THIS REGION OF THE BASIN. THIS TROUGHINESS ALOFT SUPPORT A 1011 MB LOW BEING ANALYZED IN THE NW GULF NEAR 26N95W AND A SURFACE TROUGH ALONG 23N88W...ACROSS THE YUCATAN PENINSULA TO NORTHERN GUATEMALA. MIDDLE-LEVEL DIFFLUENCE BEING GENERATED BY AN ANTICYCLONIC CIRCULATION ANCHORED ON THE SW N ATLC ALONG WITH HIGH LOW-LEVEL MOISTURE ALONG THE N-NW GULF SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS WITHIN 140 NM N-NE OF THE LOW CENTER. ISOLATED SHOWERS ASSOCIATED WITH A FORMER AREA OF LOW PRESSURE N OF THE YUCATAN PENINSULA LINGER FROM 21N-24N BETWEEN 85W-91W. FARTHER EAST...A SURFACE TROUGH EXTENDS FROM THE NORTHERN BAHAMAS SW TO 23N82W TO 21N84W...ENHANCING SCATTERED SHOWERS ACROSS THE FLORIDA STRAITS...INCLUDING THE FLORIDA KEYS. EASTERLY FLOW OF 10-15 KT DOMINATES N OF 24N AND ON THE SE GULF WHILE NORTHEASTERLY FLOW OF SIMILAR MAGNITUDE IS PRESENT ON THE SW BASIN. THE AREA OF LOW PRESSURE ON THE NW GULF IS EXPECTED TO MOVE SW INTO NE MEXICO BY THU MORNING. THE TROUGH OVER THE YUCATAN WILL CONTINUE TO MOVE WESTWARD TO CENTRAL BAY OF CAMPECHE WHERE IT DISSIPATES THU NIGHT. RAINSHOWERS ASSOCIATED WITH THESE FEATURES WILL CONTINUE THROUGH FRIDAY NIGHT. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL INVERTED TROUGH CONTINUES OVER THE WEST- CENTRAL CARIBBEAN SUPPORTING A TROPICAL WAVE WITH AXIS FROM CENTRAL- EASTERN CUBA TO THE SW BASIN. ANOTHER TROPICAL WAVE MOVED ACROSS THE EASTERN BASIN EARLIER TONIGHT. SEE THE TROPICAL WAVE SECTION FOR MORE DETAILS. DEEP LAYER MOISTURE ALONG A REGION OF UPPER- LEVEL DIFFLUENCE GENERATED BY WEAK RIDGE ON THE EASTERN BASIN SUPPORT SCATTERED MODERATE CONVECTION S OF 15N BETWEEN 70W-77W AND HEAVY SHOWERS AND TSTMS OVER NORTHERN COLOMBIA. THE PASSAGE OF THE TROPICAL WAVE ALONG WITH A TIGHT PRESSURE GRADIENT ACROSS THE NE CARIBBEAN SUPPORT TRADES OF 20-25 KT IN THIS REGION OF THE BASIN...INCLUDING PUERTO RICO ADJACENT WATERS. TRADES OF 15 KT DOMINATE ELSEWHERE. RAINSHOWER ACTIVITY ASSOCIATED WITH THE WAVES WILL PREVAIL THROUGH FRIDAY NIGHT. ...HISPANIOLA... A LOW-LEVEL DRY ENVIRONMENT PREVAILS ACROSS GREAT PORTIONS OF THE ISLAND. HOWEVER...A DIFFLUENT ENVIRONMENT S-SE OF THE ISLAND ALONG WITH MODERATE MOISTURE SUPPORT ISOLATED SHOWERS AND TSTMS OVER EASTERN DOMINICAN REPUBLIC AND ADJACENT WATERS. A TROPICAL WAVE WILL MOVE NEAR THE ISLAND THU THROUGH FRIDAY ENHANCING SHOWERS MAINLY IN SOUTHERN HISPANIOLA AND COASTAL WATERS. ATLANTIC OCEAN... A COL OR AREA OF LOW PRESSURE IN THE MIDDLE TO UPPER LEVELS ALONG WITH LOW-LEVEL MOISTURE CONVERGENCE ON THE SW N ATLC SUPPORT SCATTERED SHOWERS AND TSTMS FROM 24N-28N BETWEEN 70W- 74W. NEARBY TO THE SW...A SURFACE TROUGH EXTENDS FROM THE NORTHERN BAHAMAS SW ACROSS THE STRAITS OF FLORIDA TO THE NW CARIBBEAN ENHANCING SHOWERS IN THAT REGION. OTHERWISE...BESIDES THE TROPICAL WAVES...THE REMAINDER OF THE ATLC IS UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED NEAR 29N56W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR