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AXNT20 KNHC 180602
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU SEP 18 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 FEATURES...

AS OF 18/0300 UTC...HURRICANE EDOUARD IS CENTERED NEAR 38.7N 48.2W OR ABOUT 896 NM E-NE OF BERMUDA MOVING E-NE AT 26 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 958 MB. MAXIMUM SUSTAINED WINDS ARE 75 KT WITH GUSTS TO 90 KT. GRADUAL WEAKENING IS FORECAST DURING THE NEXT 48 HOURS AND EDOUARD IS EXPECTED TO WEAKEN BELOW HURRICANE STRENGTH ON THURSDAY...AND BECOME A POST- TROPICAL CYCLONE BY LATE FRIDAY. SCATTERED MODERATE CONVECTION IS FROM 37N-43N BETWEEN 44W-50W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS.


...TROPICAL WAVES...

TROPICAL WAVE IS RIGHT OFF THE WESTERN COAST OF AFRICA WITH AXIS EXTENDING FROM 21N15W TO 10N17W. METEOSAT RGB AND SAL IMAGERY SHOW BOTH DUST AND DRY AIR ENGULFING THE N-NW WAVE ENVIRONMENT...WHICH REMAINS DEVOID OF CONVECTION. MAINLY THICK HIGH CLOUDS ARE TO THE S-SW OF THE WAVE WHERE SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE OBSERVED FROM 6N-14N EAST OF 29W. THE GLD LIGHTING DENSITY PRODUCT SHOW SCATTERED LIGHTING STROKES FROM 11N-14N EAST OF 20W INDICATING ALSO SOME CONVECTIVE ACTIVITY JUST EAST OF THE CENTRAL WAVE AXIS.

TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS EXTENDING FROM 19N39W TO 10N42W...MOVING WEST AT 15-20 KT. THE GOES-R SEVIRI DUST PRODUCT SHOW DUST ON THE CENTRAL AND WESTERN WAVE ENVIRONMENT AND LOW TO HIGH CLOUDS ON THE NORTHERN WAVE REGION WHERE ISOLATED MODERATE CONVECTION AND TSTMS ARE NOTED FROM 15N-20N BETWEEN 36W-43W. THE REST OF THE WAVE ENVIRONMENT IS DEVOID OF CONVECTION.

TROPICAL WAVE IS JUST E OF THE LESSER ANTILLES WITH AXIS EXTENDING FROM 25N57W TO 10N60W...MOVING WEST AT 15 KT. SCATTERED MODERATE CONVECTION AND TSTMS ARE LIMITED TO THE NORTHERN WAVE ENVIRONMENT WHERE GOES-R SEVIRI DUST PRODUCT SHOW LOW TO HIGH CLOUDS. STRONG DEEP LAYER ENVIRONMENTAL SHEAR IS HINDERING CONVECTION ELSEWHERE.


...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N16W TO 11N27W TO 10N39W. THE ITCZ AXIS BEGINS WEST OF A TROPICAL WAVE NEAR 10N44W AND CONTINUES TO 9N60W. OTHER THAN THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES ALREADY DISCUSSED...SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 12N-15N BETWEEN 51W-57W.


...DISCUSSION...

GULF OF MEXICO...

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. SOUTHWEST OF THE TROUGH ALOFT...THE EASTERN PERIPHERY OF A MIDDLE TO UPPER LEVEL RIDGE DOMINATES ELSEWHERE. MODERATE DEEP LAYER MOISTURE IS ACROSS THE NW...SW AND SE GULF...WHICH IS ENHANCING ISOLATED SHOWERS AND TSTMS. TROUGHINESS ALOFT SUPPORT A SURFACE TROUGH THAT HAS BEEN MOVING ACROSS THE FLORIDA PENINSULA WED THROUGH THU MORNING...ENHANCING SHOWERS AND TSTMS. DRY AIR AND STRONG DEEP LAYER ENVIRONMENTAL SHEAR SUPPRESS CONVECTION ELSEWHERE. OTHERWISE...A 1015 MB HIGH PRESSURE CENTER IS ANCHORED NEAR 28N91W. A FRONTAL SYSTEM N OF THE AREA OF DISCUSSION WILL MOVE ACROSS THE FLORIDA PENINSULA AS A COLD FRONT THURSDAY WHILE THE REMAINDER FRONT WILL STALL ACROSS THE NORTHERN TO CENTRAL GULF. THE FRONTAL SYSTEM WILL TRANSITION TO A STATIONARY FRONT ACROSS THE CENTRAL AND SE GULF ON FRIDAY.

CARIBBEAN SEA...

AN OVERALL UNSTABLE ENVIRONMENT CONTINUES MAINLY ACROSS THE CENTRAL AND NE BASIN BEING SUPPORTED BY ABUNDANT DEEP LAYER MOISTURE AND A DIFFLUENT ENVIRONMENT ALOFT BEING GENERATED BY A MIDDLE TO UPPER LEVEL INVERTED TROUGH ON THE NW BASIN AND A RIDGE DOMINATING ELSEWHERE. THIS SYNOPTIC PATTERN IS ENHANCING ISOLATED SHOWERS S OF 19N BETWEEN 73W-82W AND ISOLATED TSTMS ON CENTRAL-SOUTHERN HAITI. ISOLATED SHOWERS AND TSTMS ARE ALSO ON THE MONA PASSAGE AND WESTERN PUERTO RICO. STRONG DEEP LAYER ENVIRONMENTAL SHEAR INHIBITS CONVECTION ELSEWHERE. OTHERWISE...A RELAXED PRESSURE GRADIENT CONTINUE TO SUPPORT TRADES OF 10-15 KT ACROSS THE BASIN. THE NEXT TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE EASTERN CARIBBEAN THU MORNING...ACROSS HISPANIOLA FRIDAY AND ACROSS CUBA SATURDAY.


...HISPANIOLA...

ISOLATED SHOWERS AND TSTMS OVER CENTRAL-SOUTHERN HAITI BEING SUPPORTED BY ABUNDANT DEEP LAYER MOISTURE IN THE REGION AS WELL AS AN UPPER-LEVEL DIFFLUENT ENVIRONMENT. RAINSHOWERS ACTIVITY IS FORECAST TO CONTINUE THROUGH THU NIGHT AND INCREASE BY FRIDAY DUE TO THE PASSAGE OF A TROPICAL WAVE.

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 EXTENDS NORTHWARD FROM THE CARIBBEAN. THIS SYNOPTIC PATTERN ALOFT IS GENERATING A DIFFLUENT ENVIRONMENT IN THE SW N ATLC WHICH ALONG ABUNDANT DEEP LAYER MOISTURE SUPPORT SCATTERED MODERATE/ISOLATED STRONG CONVECTION AND TSTMS N OF 24N W OF 68W. SHOWERS AND ISOLATED TSTMS ARE ALSO ALONG THE COAST AND ADJACENT WATERS OF NORTHERN CUBA. OTHERWISE...BESIDES THE TWO TROPICAL WAVES DISCUSSED IN THE WAVES SECTION...SURFACE RIDGING AND FAIR WEATHER DOMINATE ELSEWHERE.

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

$$ NR

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