Home


000
AXNT20 KNHC 200005
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE AUG 19 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...

A TROPICAL WAVE IS ABOUT 300 NM EAST OF THE LESSER ANTILLES ASSOCIATED WITH A 1009 MB LOW EMBEDDED IN THE MONSOON TROUGH. HIGH DEEP LAYER MOISTURE ALONG WITH A MIDDLE TO UPPER LEVEL DIFFLUENT ENVIRONMENT IS SUPPORTING SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS FROM 7N-13N BETWEEN 48W-55W. DRY SAHARAN AIR AND DUST ARE PRESENT IN THE NORTHERN WAVE ENVIRONMENT...WHICH IS HINDERING CONVECTION N OF 13N. ENVIRONMENTAL CONDITIONS ARE FORECAST TO BE MORE CONDUCIVE FOR GRADUAL DEVELOPMENT OF THIS SYSTEM DURING THE NEXT FEW DAYS AS IT APPROACHES THE LESSER ANTILLES AND MOVES INTO THE CARIBBEAN SEA. MEDIUM CHANCE OF DEVELOPMENT IS EXPECTED THROUGH 48 HOURS. SEE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 KNHC FOR MORE DETAILS.


...TROPICAL WAVES...

A TROPICAL WAVE CAME OFF THE WESTERN AFRICAN COAST EARLIER THIS AFTERNOON WITH A WELL-DEFINED AXIS ALONG 18W. MOSTLY MEDIUM DEEP LAYER MOISTURE IS ASSOCIATED WITH THIS SYSTEM WHICH ALONG UPPER- LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS FROM 13N-17N E OF 20W. SAHARAN DRY AIR ENGULFS THE NORTHERN PORTION OF THE WAVE...THUS DEVOIDING OF CONVECTION THE REGION OF THE WAVE N OF 17N.

A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM 24N39W TO 12N39W...MOVING W AT 15 KT. NORTH OF 14N THE WAVE IS BEING AFFECTED BY THE DRY SAHARAN AIR LAYER WHICH IS HINDERING CONVECTION IN THAT PORTION OF THE WAVE. SCATTERED MODERATE CONVECTION IS CONFINED WITHIN 200 NM SOUTHWEST OF THE WAVE AXIS FROM 12N-14N BETWEEN 39W-42W.

A TROPICAL WAVE IS NEAR 51W. SEE THE SPECIAL FEATURES SECTION OF THE DISCUSSION.

A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA...GUATEMALA AND THE EASTERN PACIFIC WATERS WITH AXIS EXTENDING FROM 22N88W TO 8N92W...MOVING W AT 15-20 KT. SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE MAINLY INLAND WITH SOME OF THE CONVECTION ENTERING THE EASTERN BAY OF CAMPECHE.


...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH BEGINS WEST OF A TROPICAL WAVE NEAR 14N21W AND CONTINUES ALONG 13N39W TO A 1009 MB LOW NEAR 9N51W TO 8N61W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...ISOLATED MODERATE CONVECTION IS FROM 10N-14N BETWEEN 24W-35W.


...DISCUSSION...

GULF OF MEXICO...

WEAK SURFACE RIDGING ACROSS NORTHEASTERN GULF OF MEXICO IS SUPPORTING MAINLY 5 TO 10 KT ANTICYCLONIC WINDS WITH THE EXCEPTION OF THE EASTERN BAY OF CAMPECHE WHERE 15 KT WINDS ARE NOTED IN A SCATTEROMETER PASS AHEAD OF A TROPICAL WAVE TO MOVE INTO THE SW GULF LATER TONIGHT. THE NORTHERN PORTION OF THIS TROPICAL WAVE IS ALREADY ENHANCING SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ACROSS THE YUCATAN PENINSULA WHICH ARE BEGINNING TO SPREAD INTO THE EASTERN BAY OF CAMPECHE. WEAK UPPER LEVEL DIFFLUENCE IS SUPPORTING ISOLATED MODERATE CONVECTION ACROSS THE WEST CENTRAL GULF FROM 24N-26N BETWEEN 90W-93W. ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE BAY OF CAMPECHE THROUGH WED MORNING AS THE TROPICAL WAVE CONTINUES TO MOVE WESTWARD. SURFACE RIDGING WILL DOMINATE ELSEWHERE WITHIN THE NEXT THREE DAYS.

CARIBBEAN SEA...

MAINLY 10 TO 25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA. BASED ON A SCATTEROMETER PASS...THE STRONGEST WINDS ARE OCCURRING ACROSS THE SOUTHWESTERN BASIN S OF 15N. AN UPPER-LEVEL DIFFLUENCE PATTERN ALONG WITH DEEP LAYER MOISTURE SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS S OF 15N W OF 77W...INCLUDING NICARAGUA...COSTA RICA AND PANAMA. AN UPPER LEVEL LOW IS CENTERED NE OF THE LEEWARD ISLANDS WHICH ALONG A PATCH OF LOW-LEVEL MODERATE MOISTURE SUPPORT ISOLATED TO SCATTERED SHOWERS ACROSS PUERTO RICO AND THE VIRGIN ISLANDS. THE UPPER-LEVEL LOW NE OF THE LEEWARD ISLANDS ALONG WITH ANOTHER UPPER-LEVEL LOW ON THE NW CARIBBEAN IS GENERATING A DIFFLUENT ENVIRONMENT OVER HISPANIOLA. THIS ENVIRONMENT ALOFT ALONG WITH MODERATE/HIGH DEEP LAYER MOISTURE SUPPORT SCATTERED HEAVY SHOWERS AND TSTMS OVER WESTERN DOMINICAN REPUBLIC...HAITI AND ADJACENT WATERS. ELSEWHERE...FAIR WEATHER DOMINATE BEING INFLUENCED BY A DRY SAHARAN AIRMASS MOVING ACROSS THE REGION. DUST AND HAZE ARE BEING REPORTED BY SEVERAL LOCATIONS ACROSS THE CENTRAL AND EASTERN BASIN. THE NEXT TROPICAL WAVE IS FORECAST TO ENTER THE EASTERN CARIBBEAN BY FRI MORNING.


...HISPANIOLA...

AN UPPER-LEVEL LOW CENTERED NE OF THE LEEWARD ISLANDS ALONG WITH ANOTHER UPPER-LEVEL LOW ON THE NW CARIBBEAN IS GENERATING A DIFFLUENT ENVIRONMENT OVER HISPANIOLA. THIS ENVIRONMENT ALOFT ALONG WITH MODERATE/HIGH DEEP LAYER MOISTURE SUPPORT SCATTERED HEAVY SHOWERS AND TSTMS OVER WESTERN DOMINICAN REPUBLIC...HAITI AND ADJACENT WATERS. SHOWERS ARE EXPECTED TO CONTINUE DURING THE NEXT 24 HOURS.

ATLANTIC OCEAN...

MODERATE LOW-LEVEL MOISTURE ASSOCIATED WITH THE PASSAGE OF THE TROPICAL WAVE CURRENTLY MOVING ACROSS THE YUCATAN PENINSULA IS ENHANCING SCATTERED/ISOLATED SHOWERS ON THE FLORIDA STRAITS...AS WELL AS THE NORTHERN AND CENTRAL BAHAMAS. OTHERWISE...BESIDES THE TROPICAL WAVES ALREADY DISCUSSED...THE REMAINDER BASIN IS UNDER THE INFLUENCE OF SURFACE RIDGING BEING ANCHORED BY A 1024 MB HIGH NEAR 35N34W AND A 1019 MB HIGH NEAR 26N66W.

FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE

$$ NAR/ASL

Home