[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190604
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...SPECIAL FEATURES...

AS OF 19/0300 UTC...TROPICAL STORM EDOUARD IS CENTERED NEAR
39.9N 39.2W OR ABOUT 494 NM W-NW OF FAYAL ISLAND IN THE WESTERN
AZORES MOVING E AT 15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS
980 MB. MAXIMUM SUSTAINED WINDS ARE 60 KT WITH GUSTS TO 75 KT.
WEAKENING IS EXPECTED DURING THE NEXT 48 HOURS...AND
EDOUARD IS FORECAST TO BECOME A POST-TROPICAL CYCLONE BY FRIDAY
NIGHT. SCATTERED MODERATE CONVECTION IS FROM 36N-42N BETWEEN 33W-
38W. 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 18N18W TO A 1009 MB LOW NEAR 11N20W...WHICH IS EMBEDDED IN
THE MONSOON TROUGH. THE WAVE IS MOVING AT APPROXIMATELY 10 KT.
METEOSAT RGB AIRMASS IMAGERY SHOW THICK HIGH CLOUDS N OF THE LOW
AND NE OF THE WAVE AXIS WHERE STRONG CONVECTION AND ISOLATED
TSTMS ARE OBSERVED. WARM...MOIST AIR AT THE MIDDLE LEVELS IS
NOTED WEST AND SOUTH OF THE LOW WHILE SAHARAN DRY AIR AND DUST
CONTINUES TO ENGULF THE N-NW WAVE ENVIRONMENT.

TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS
EXTENDING FROM 19N45W TO A 1012 MB LOW NEAR 15N46W TO 10N47W
...MOVING WEST AT 10 KT. THE GOES-R RGB AIRMASS PRODUCT INDICATE
A MOIST MIDDLE TO UPPER LEVEL WAVE ENVIRONMENT EXCEPT NW OF THE
LOW WHERE DRY CONDITIONS ARE PRESENT...ALSO DEPICTED IN METEOSAT
SAL TRACKING IMAGERY. LITTLE TO NONE DUST IS DEPICTED IN THE
GOES-R DUST PRODUCT IN THIS REGION OF DRY AIR. STRONG DEEP LAYER
ENVIRONMENTAL SHEAR IS OVER THE WAVE ENVIRONMENT WHICH IS
LIMITING THE CONVECTION TO ISOLATED MODERATE FROM 7N-15N BETWEEN
42W-51W AND FROM 15N-18N WITHIN 250 NM OF THE WAVE AXIS.

TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS
EXTENDING FROM 21N65W TO 10N66W...MOVING WEST AT 10 KT. MOSTLY
MODERATE DEEP LAYER MOISTURE IS ASSOCIATED WITH THE WAVE IN THE
CARIBBEAN WITH PATCHES OF HIGH MOISTURE N OF 16N BETWEEN 64W-
68W. STRONG DEEP LAYER ENVIRONMENTAL SHEAR IS HINDERING
CONVECTION ELSEWHERE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N16W TO
A 1009 MB LOW NEAR 11N19W TO 7N30W. THE ITCZ AXIS EXTENDS FROM
7N31W TO 10N43W...THEN RESUMES W OF A TROPICAL WAVE AT 10N50W TO
7N58W. OTHER THAN THE CONVECTION MENTIONED IN THE TROPICAL WAVE
SECTION...SCATTERED MODERATE CONVECTION IS FROM 8N-11N BETWEEN
50W-57W.

...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 A 1012 MB LOW IN SOUTHERN MISSISSIPPI. A PRE-
FRONTAL TROUGH EXTENDS FROM THE SW N ATLC...ACROSS SOUTHERN
FLORIDA TO 24N85W IN THE SE GULF. SCATTERED SHOWERS ARE ACROSS
THE EASTERN GULF AND IN THE NW BASIN N OF 25N. 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 17N W OF 78W. A TROPICAL
WAVE IS MOVING ACROSS THE EASTERN BASIN WHICH IS SUPPORTING
HEAVY SHOWERS AND TSTMS N OF 16N BETWEEN 64W-68W. SEE THE TROPICAL
WAVES SECTION FOR MORE DETAILS. 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...

EXCEPT FOR SW HAITI WHERE ISOLATED SHOWERS AND TSTMS ARE
NOTED...THE REMAINDER ISLAND IS CLOUDY WITH POSSIBLE ISOLATED
SHOWERS. HOWEVER...A TROPICAL WAVE CURRENTLY MOVING ACROSS PUERTO
RICO WILL INCREASE SHOWER ACTIVITY STARTING FRIDAY MORNING AS IT
CONTINUES IT WESTWARD PATH TO MOVE ACROSS HISPANIOLA ON FRIDAY.

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


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