000 AXNT20 KNHC 290559 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUL 29 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. ...SPECIAL FEATURE... A DISTURBANCE OVER THE CENTRAL TROPICAL ATLANTIC HAS BECOME BETTER ORGANIZED DURING THE PAST SEVERAL HOURS. THE SYSTEM IS ASSOCIATED WITH A 1010 MB LOW EMBEDDED IN THE MONSOON TROUGH NEAR 9N35W. RAINBANDS OF SCATTERED MODERATE CONVECTION ARE FROM 5N-14N BETWEEN 31W-42W. THERE IS A MEDIUM CHANCE OF FURTHER DEVELOPMENT OF THIS DISTURBANCE WITHIN 48 HOURS. SEE THE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE CAME OFF THE WEST AFRICAN COAST MONDAY EVENING. ITS AXIS IS CURRENTLY NEAR 18W OR ABOUT 250 NM E OF THE CAPE VERDE ISLANDS. THE NORTHERN ENVIRONMENT OF THE WAVE IS EMBEDDED IN THE DRY SAHARAN AIR LAYER WHILE S OF 13N THE WAVE IS ASSOCIATED WITH DEEP LAYER MOISTURE. A CLUSTER OF MODERATE CONVECTION AND ISOLATED TSTMS IS IN THE SOUTHERN WAVE ENVIRONMENT FROM 5N-10N BETWEEN 17W-23W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 5N-10N BETWEEN 14W-23W. A TROPICAL WAVE IS W-NW OF AN AREA OF DISTURBED WEATHER OVER THE CENTRAL ATLC. THE AXIS OF THE WAVE EXTENDS FROM 17N41W TO 8N39W MOVING W AT 10 KT DURING THE PAST 24 HOURS. MOST OF THE WAVE ENVIRONMENT IS IN THE DRY SAHARAN AIR LAYER WHICH IS HINDERING THE DEVELOPMENT OF DEEP CONVECTION. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM THE COAST OF WEST AFRICA NEAR 10N15W TO 8N21W 8N29W TO A 1010 MB LOW NEAR 9N35W TO 6N42W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 6N42W TO THE COAST OF N-NE SOUTH AMERICA NEAR 5N52W. AREAS OF CONVECTION ARE ASSOCIATED WITH TROPICAL WAVES. SEE THE SECTIONS ON TROPICAL WAVES AND SPECIAL FEATURES FOR DETAILS. ...DISCUSSION... GULF OF MEXICO... A BROAD MID-UPPER LEVEL TROUGH EXTENDS ACROSS THE EASTERN CONUS SUPPORTING A STATIONARY FRONT THAT EXTENDS FROM A 1008 MB LOW OVER SOUTH CAROLINA SW ACROSS CENTRAL GEORGIA TO LOUISIANA TO TEXAS. A PRE-FRONTAL TROUGH IS OVER THE NE BASIN EXTENDING FROM 31N83W TO 29N88W AND SUPPORTING SCATTERED SHOWERS AND TSTMS N OF 27N E OF 90W. OVER THE SW GULF...A CLUSTER OF MODERATE CONVECTION AND TSTMS IS S OF 21N E OF 95W ASSOCIATED WITH THE NORTHERN PORTION OF A TROPICAL WAVE MOVING INTO E PACIFIC WATERS. THE REST OF THE GULF IS BEING INFLUENCED BY RIDGING ALOFT WHICH IS SUPPORTING A 1019 MB HIGH NEAR 26N92W. DRY AIR SUBSIDENCE FROM ALOFT ALONG WITH SURFACE HIGH PRESSURE PROVIDE A GENERAL STABLE ENVIRONMENT THAT SUPPORT FAIR WEATHER ELSEWHERE IN THE GULF. VARIABLE WINDS OF 5-15 KT PREVAILS ACROSS THE GULF N OF 21N WHILE WINDS UP TO 20 KT ARE OVER THE BAY OF CAMPECHE IN ASSOCIATION WITH THE TROPICAL WAVE. THE STATIONARY FRONT WILL TRANSITION TO A COLD FRONT LATER THIS MORNING AND MOVE INTO THE NE GULF WHERE IT IS EXPECTED TO TRANSITION BACK INTO A STATIONARY FRONT LATER DURING THE DAY. THE FRONTAL SYSTEM IS EXPECTED TO DISSIPATE OVER THE EASTERN GULF WED MORNING. SURFACE RIDGING WILL PREVAIL ELSEWHERE DURING THIS PERIOD. CARIBBEAN SEA... WITH THE EXCEPTION TO THE FAR WESTERN AND SW CARIBBEAN...LOWER TO MIDDLE LEVEL DRY AIR DOMINATES ACROSS THE REGION ALONG WITH STRONG DEEP LAYER ENVIRONMENTAL WIND SHEAR. THESE TWO FACTORS PROVIDE OVERALL STABILITY...THUS SUPPORTING CLEAR SKIES. A DIFFLUENT ENVIRONMENT ALOFT OVER THE GREATER ANTILLES ALONG WITH PATCHES OF LOW-LEVEL MOISTURE SUPPORT SHOWERS AND TSTMS OVER COASTAL WATERS OF WESTERN CUBA N OF 21N...SCATTERED SHOWERS OVER CENTRAL AND WESTERN HISPANIOLA AND PASSING SHOWERS OVER EASTERN PUERTO RICO. CLOUDINESS AS WELL AS ISOLATED SHOWERS AND TSTMS ASSOCIATED WITH THE PASSAGE OF A TROPICAL WAVE ARE ALONG CENTRAL AMERICA COASTAL WATERS N OF 9N W OF 81W. OTHERWISE...A CONTINUAL TIGHT PRESSURE GRADIENT BETWEEN A LOW OVER NORTHERN COLOMBIA AND HIGH PRESSURE FROM THE ATLC EXTENDING INTO THE CARIBBEAN SUPPORT TRADES OF 20-25 KT S OF 17N BETWEEN 66W-82W WITH NEAR GALE FORCE WINDS ALONG THE COAST OF COLOMBIA. A TROPICAL WAVE IS EXPECTED TO ENTER THE EASTERN CARIBBEAN THU MORNING AHEAD OF A POSSIBLE TROPICAL CYCLONE. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. ...HISPANIOLA... CURRENTLY...A DIFFLUENT ENVIRONMENT ALOFT SUPPORTS CLOUDINESS AND POSSIBLE ISOLATED SHOWERS ACROSS HAITI AND WESTERN DOMINICAN REPUBLIC. MOSTLY FAIR WEATHER IS FORECAST FOR TUE...HOWEVER MODEL GUIDANCE PREDICTS SHOWERS ACROSS PORTIONS OF THE ISLAND MOST OF THE DAY WEDNESDAY. ATLANTIC OCEAN... A MID-UPPER LEVEL TROUGH OVER THE EASTERN CONUS ALONG WITH THE SE PERIPHERY OF A RIDGE GENERATE A DIFFLUENT ENVIRONMENT ALOFT OVER THE SW N ATLC WATERS WHICH ALONG MODERATE DEEP LAYER MOISTURE IN THE REGION SUPPORT SHOWERS AND TSTMS NW OF FREEPORT FROM 26N-29N BETWEEN 77W-80W. OVER THE E ATLC...A MID-UPPER LEVEL LOW N OF THE AREA CONTINUE TO SUPPORT A SURFACE TROUGH FROM 30N27W TO 27N28W WITH NO CONVECTION ASSOCIATED WITH IT. THE REMAINDER BASIN IS FAIRLY DRY AND UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED BY A 1026 MB HIGH NEAR 33N53W. THESE TWO FACTORS SUPPORTS FAIR WEATHER ELSEWHERE IN THE BASIN. OTHERWISE...SEE ABOVE THE SPECIAL FEATURES AND TROPICAL WAVES SECTIONS. SURFACE RIDGING WILL DOMINATE ACROSS THE CENTRAL AND EASTERN ATLC THE TUE AND WED. A FRONTAL BOUNDARY IS EXPECTED TO MOVE ACROSS THE SW N ATLC TODAY THROUGH THU MORNING. ANOTHER FRONTAL SYSTEM IS EXPECTED TO SINK INTO THE NORTHERN CENTRAL ATLC BY EARLY THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS