000 AXNT20 KNHC 302348 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUN 30 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. ...SPECIAL FEATURES... AN AREA OF LOW PRESSURE CENTERED ABOUT 80 NM EAST OF VERO BEACH FLORIDA HAS SHOWN LITTLE CHANGE IN ORGANIZATION WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM IN THE SE SEMICIRCLE OF THE LOW...AND EXTENDING WESTWARD OVER MOST OF SOUTH FLORIDA. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE FOR ADDITIONAL DEVELOPMENT AND A TROPICAL DEPRESSION COULD FORM LATER TONIGHT OR TUESDAY. INTERESTS ALONG THE FLORIDA AND SOUTHEAST U.S. COAST SHOULD MONITOR THIS SYSTEM CLOSELY AND REFER TO THE ATLANTIC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 KNHC FOR ADDITIONAL INFORMATION. ...TROPICAL WAVES... TROPICAL WAVE HAS MOVED OFF THE W COAST OF AFRICA WITH AXIS EXTENDING FROM 20N19W TO 9N20W. SAHARAN AIR ENGULFS THIS WAVE LIMITING CONVECTION TO THE SOUTHERN PORTION OF THE WAVE NEAR THE MONSOON TROUGH. TROPICAL WAVE IS OVER THE E CARIBBEAN SEA WITH AXIS EXTENDING FROM 18N65W TO 9N67W. DEEP LAYER MOISTURE AND UPPER LEVEL DIFFLUENCE OVER THE NE CARIBBEAN IS SUPPORTING SCATTERED SHOWERS AND TSTMS OVER THE NORTHERN WINDWARD AND LEEWARD ISLANDS AND PUERTO RICO. TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 19N74W TO THE N COAST OF VENEZUELA NEAR 77W MOVING W AT 15 TO 20 KT WITH NO CONVECTION ASSOCIATED WITH IT. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF SENEGAL NEAR 13N17W THROUGH 10N20W 7N30W TO 5N40W. THE ITCZ BEGINS NEAR 5N40W AND CONTINUES TO THE COAST OF SOUTH AMERICA NEAR 2N50W. SCATTERED MODERATE CONVECTION IS FROM 4N-8N E OF 30W. ...DISCUSSION... ...THE GULF OF MEXICO... COMPLEX MID-TO UPPER LEVEL PATTERN IN PLACE OVER THE GULF OF MEXICO WITH A CYCLONIC CIRCULATION OVER THE UPPER TEXAS COAST AND AN ATTENDANT SHEAR/TROUGH AXIS EXTENDING SE THROUGH THE YUCATAN CHANNEL. A SHORTWAVE UPPER LEVEL RIDGE WAS BUILDING NORTHWARD OVER THE BAY OF CAMPECHE ALONG 93W. FAIRLY DEEP LAYERED ELONGATED ANTICYCLONE OVER GEORGIA AND FLORIDA WAS SUPPORTING A WEAK SURFACE RIDGE ANCHORED BY A 1019 MB HIGH NEAR 28N89W. HIGH PRESSURE AND DRY AIR SUBSIDENCE IS SUPPORTING FAIR WEATHER ACROSS MUCH OF THE BASIN. REMNANTS OF A SAHARAN AIRMASS ADVECTED FROM THE CARIBBEAN SEA IS SUPPORTING HAZE OVER THE CENTRAL GULF. SOME DEEP LAYER MOISTURE ACROSS THE BAY OF CAMPECHE REMAINS FROM EARLIER SCATTERED MODERATE SHOWERS AND TSTMS. SCATTERED STRONG THUNDERSTORMS WERE EMERGING OFF THE SW FLORIDA COAST NEAR EVERGLADES CITY EXTENDING ALONG AND WITHIN 60 NM OF THE COAST TO THE TAMPA BAY AREA. SURFACE WINDS ACROSS THE BASIN ARE GENERALLY LIGHT WITH RETURN LOW OF 15-20 KT ALONG THE TEXAS COAST. HIGH PRESSURE IS FORECAST TO PERSIST DURING THE NEXT TWO DAYS. ...THE CARIBBEAN SEA... AN UPPER LEVEL TROUGH/SHEAR AXIS EXTENDS FROM THE WINDWARD PASSAGE WESTWARD ACROSS THE NORTHERN CARIBBEAN TO THE YUCATAN CHANNEL WHILE A BROAD FLAT ANTICYCLONE AND RIDGING PERSISTS OVER THE BASIN S OF 15N. STRONG SUBSIDENCE WAS NOTED OVER CUBA AND HISPANIOLA. AT THE SURFACE...TWO TROPICAL WAVES ARE MOVING ACROSS THE BASIN. SEE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. EXCEPT FOR THE SW AND E CARIBBEAN WHERE DEEP LAYER MOISTURE ABOUNDS...REMNANTS OF A SAHARAN AIRMASS COVER THE REMAINDER OF THE BASIN WHICH ALONG STRONG DEEP LAYER ENVIRONMENTAL WIND SHEAR HINDERS DEEP CONVECTION. HOWEVER...DUST ASSOCIATED WITH THIS AIRMASS IS SUPPORTING HAZE ACROSS THE GREATER ANTILLES. THE PRESSURE GRADIENT BETWEEN THE ATLANTIC RIDGE AND A MONSOON TROUGH INTO NORTHERN COLOMBIA IS MAINTAINING 20-25 KT TRADES IN THE CENTRAL CARIBBEAN AND 10-20 KT WINDS IN THE WESTERN AND EASTERN CARIBBEAN. ...HISPANIOLA... DRY SAHARAN AIRMASS CONTINUES ACROSS THE GREATER ANTILLES SUPPORTING FAIR BUT HAZY WEATHER CONDITIONS. THE CONTINUED PRESENCE OF THE SAHARAN AIR LAYER IN THE AREA DURING THE NEXT DAY OR SO SHOULD RESULT IN DELAYED DEVELOPMENT OF AFTERNOON CONVECTION WITH GENERALLY LESS COVERAGE THAN TYPICALLY EXPECTED. ...THE ATLANTIC OCEAN... AN AREA OF LOW PRESSURE WITH A HIGH POTENTIAL OF BECOMING A TROPICAL CYCLONE IN THE NEXT FEW DAYS WAS LOCATED 80 NM E OF VERO BEACH FLORIDA. REFER TO THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. THE LOW PRESSURE AREA WAS EMBEDDED WITHIN AN AREA OF NORTHWESTERLY UPPER LEVEL FLOW WHICH COVERED THE ATLANTIC W OF 66W. FURTHER EAST...A BROAD UPPER LEVEL TROUGH CONTINUES TO SUPPORT AN ACTIVE SURFACE TROUGH FROM ALONG 32N52W TO 27N60W WHICH IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 180 NM EAST OF THE TROUGH. OTHERWISE...A BROAD SURFACE RIDGE ANCHORED BY A 1027 MB HIGH NEAR 37N36W EXTENDS WSW TO 22N55W GENERALLY SUPPORTING FAIR WEATHER CONDITIONS ACROSS MOST OF THE REMAINDER OF THE BASIN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB