Home


000
AXNT20 KNHC 191056
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI SEP 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC.


...SPECIAL FEATURES...

AS OF 19/0900 UTC...TROPICAL STORM EDOUARD IS CENTERED NEAR 39.8N 38.5W OR ABOUT 462 NM W-NW OF FAYAL ISLAND IN THE WESTERN AZORES MOVING E AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT. WEAKENING IS EXPECTED DURING THE NEXT 48 HOURS...AND EDOUARD IS FORECAST TO BECOME A POST-TROPICAL CYCLONE LATER TODAY. THE CONVECTION ASSOCIATED WITH EDOUARD HAS REDUCED SIGNIFICANTLY AND LIES SE OF THE CENTER FROM 34N-39N BETWEEN 33W-37W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.


...TROPICAL WAVES...

TROPICAL WAVE IS OVER THE FAR EASTERN ATLC WITH AXIS EXTENDING FROM 17N18W TO A 1008 MB LOW NEAR 12N19W TO 9N19W. THE WAVE IS MOVING AT APPROXIMATELY 10 KT. METEOSAT RGB AIRMASS IMAGERY SHOW THICK HIGH CLOUDS N-NW OF THE LOW WHERE THE STRONGEST CONVECTION IS OBSERVED AS SCATTERED MODERATE WITH ISOLATED TSTMS. CONVECTION IN THE S-SW WAVE ENVIRONMENT IS LIMITED DUE TO SOME DRY AIR AND DUST INTRUSION NOTED IN THE GOES-R SEVIRI DUST PRODUCT AND THE SSMI TPW IMAGERY.

TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS EXTENDING FROM 19N46W TO 8N48W...MOVING WEST AT 15 KT. SCATTERED LOW TO HIGH LEVEL CLOUDS ACCOMPANY THE WAVE EXCEPT NW OF THE AXIS WHERE THE GOES-R DUST PRODUCT AND THE METEOSAT SATELLITE IMAGERY SHOW DRY AIR AND DUST. SCATTERED MODERATE CONVECTION IS WITHIN 210 NM E OF THE AXIS AND 300 NM W OF THE AXIS S OF 11N.

TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 21N66W TO 11N67W...MOVING WEST AT 15 KT. MOSTLY MODERATE DEEP LAYER MOISTURE IS ASSOCIATED WITH THE WAVE IN THE CARIBBEAN WITH PATCHES OF HIGH MOISTURE N OF 17N BETWEEN 65W-67W WHERE SCATTERED HEAVY SHOWERS AND TSTMS ARE OBSERVED. STRONG DEEP LAYER ENVIRONMENTAL SHEAR IS HINDERING CONVECTION ELSEWHERE.


...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N16W TO A 1008 MB LOW NEAR 12N19W TO 8N31W. THE ITCZ AXIS EXTENDS FROM 8N31W TO 9N45W...THEN RESUMES W OF A TROPICAL WAVE AT 9N49W TO 6N58W. FOR INFORMATION ABOUT CONVECTION SEE THE TROPICAL WAVE SECTION.


...DISCUSSION...

GULF OF MEXICO...

AN OVERALL UNSTABLE ENVIRONMENT IS ACROSS THE GULF BEING INFLUENCED BY LOW PRESSURE AT THE SURFACE...A DIFFLUENT ENVIRONMENT IN THE MIDDLE AND UPPER LEVELS AND DEEP LAYER MOISTURE. A BROAD MIDDLE TO UPPER LEVEL TROUGH EXTENDING ACROSS THE EASTERN U.S. TO THE WEST ATLC NEAR 60W HAS ITS BASE REACHING THE EASTERN GULF...THE FLORIDA PENINSULA AND THE SW N ATLC. THIS TROUGH ALOFT SUPPORT A STATIONARY FRONT ANALYZED ACROSS NORTHERN FLORIDA WESTWARD TO SW LOUISIANA. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE ACROSS THE EASTERN GULF E OF 91W N OF 23N. SURFACE TROUGHINESS WILL DOMINATE ACROSS THE GULF ALONG ABUNDANT MOISTURE ADVECTED FROM THE CARIBBEAN WHICH WILL FUEL RAINSHOWERS ACROSS THE BASIN OVER THE WEEKEND.

CARIBBEAN SEA...

EXCEPT FOR SOUTH OF HISPANIOLA AND A PORTION OF THE NW CARIBBEAN...MODERATE MIDDLE TO LOWER LEVEL MOISTURE DOMINATES IN THE REGION ALONG WITH LIGHT TRADE WINDS. MIDDLE LEVEL DIFFLUENCE IN THE WESTERN BASIN GENERATED BY AN INVERTED TROUGH W OF 80W AND AN ANTICYCLONIC CIRCULATION ANCHORED OVER HISPANIOLA ENHANCES ISOLATED SHOWERS AND TSTMS S OF 18N W OF 80W. A TROPICAL WAVE IS MOVING ACROSS THE EASTERN BASIN WHICH IS SUPPORTING SCATTERED HEAVY SHOWERS AND TSTMS N OF 17N BETWEEN 64W-68W. SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. SIMILAR CONVECTION IS ON THE SE BASIN S OF 15N E OF 65W BEING SUPPORTED BY A MIDDLE TO UPPER LEVEL INVERTED TROUGH. ELSEWHERE...STRONG DEEP LAYER ENVIRONMENTAL SHEAR AND DRY AIR SUBSIDENCE FROM ALOFT SUPPRESS CONVECTION. THE TROPICAL WAVE IS FORECAST TO MOVE ACROSS HISPANIOLA FRIDAY AND ACROSS CUBA ON SATURDAY.


...HISPANIOLA...

FAIR WEATHER DOMINATES ACROSS THE ISLAND THIS MORNING AS DEEP LAYER DRY AIR IS ON THE REGION. HOWEVER...A TROPICAL WAVE CURRENTLY MOVING ACROSS PUERTO RICO WILL START AFFECTING THE WEATHER LATER THIS MORNING THROUGH SATURDAY MORNING AS IT MOVES ACROSS THE ISLAND.

ATLANTIC OCEAN...

A BROAD MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE EASTERN U.S. TO THE WEST ATLC NEAR 60W WITH ITS BASE EXTENDING ACROSS FLORIDA AND THE SW N ATLC. SOUTH-SOUTHEAST OF THE TROUGH...A BROAD MIDDLE TO UPPER LEVEL RIDGE IS GENERATING A DIFFLUENT ENVIRONMENT IN THE SW N ATLC THAT ENHANCES ISOLATED SHOWERS AND TSTMS N OF 25N W OF 69W. THIS CONVECTION IS ALSO BEING SUPPORTED BY A SURFACE TROUGH ALONG 29N73W TO 26N80W TO THE SE GULF. ANOTHER SURFACE TROUGH IS ON THE SW PERIPHERY OF THE SURFACE RIDGE WHICH ALONG A TROPICAL WAVE SOUTHWARD SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS S OF 24N BETWEEN 64W-67W. SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. OTHERWISE...SURFACE RIDGING AND FAIR WEATHER DOMINATE ELSEWHERE.

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

$$ NR

Home