[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 071046
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUL 07 2012

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
1035 UTC.

...TROPICAL WAVES...

TROPICAL WAVE MOVES ACROSS THE CENTRAL ATLC WITH AXIS ANALYZED
FORM 23N47W TO 12N44W MOVING W AT ABOUT 15 KT. THE WAVE LIES ON
THE WRN SIDE OF A SURGE OF DEEP LAYER MOISTURE NOTICED ON TPW
IMAGERY. NO SIGNIFICANT DEEP CONVECTION IS OBSERVED DUE TO
SAHARAN DUST EMBEDDED IN THE WAVE ENVIRONMENT.

TROPICAL WAVE IS MOVING ACROSS THE WRN CARIBBEAN WITH AXIS
ANALYZED FROM 25N80W TO 11N85W MOVING W NEAR 10-15 KT. THE WAVE
IS EMBEDDED IN A LARGE SURGE OF DEEP LAYER MOISTURE COVERING THE
WRN CARIBBEAN TO THE CENTRAL BAHAMAS. AN EARLIER SCATTEROMETER
PASS REVEALED A WELL DEFINED LOW-LEVEL CYCLONIC TURNING AROUND
THE WAVE AXIS. SCATTERED HEAVY RAINFALL AND THUNDERSTORM
ACTIVITY COVER THE SW AND NW CARIBBEAN BASINS W OF 80W...AS WELL
AS ACROSS THE BAHAMAS AND NRN COASTAL WATERS OF CUBA S OF 25N
BETWEEN 72W-80W.

FIRST VISIBLE SATELLITE PICTURES OF THE DAY REVEALED A BROAD
AREA OF MODERATE TO ISOLATED STRONG CONVECTION OVER THE FAR ERN
TROPICAL ATLC...ASSOCIATED TO A TROPICAL WAVE MOVING OFF THE
COAST OF THE WEST AFRICA. THE WAVE AXIS WILL BE ADDED TO THE
SURFACE ANALYSIS TODAY...AS MODEL DATA AND SURFACE OBSERVATIONS
BECOME MORE CONCLUSIVE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS SW FROM THE WEST AFRICAN COAST OF
MAURITANIA NEAR 18N16W ALONG 10N21W 8N30W TO 7N41W...WHERE THE
ITCZ AXIS CONTINUES TO THE COAST OF FRENCH GUIANA NEAR 5N52W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION COVERS THE AREA
E OF 27W FROM 6N-14N. THIS AREA OF CONVECTION IS ALSO RELATED TO
A TROPICAL WAVE MOVING OFF THE COAST OF WEST AFRICA DISCUSSED
ABOVE. OTHERWISE...SCATTERED WEAK TO ISOLATED MODERATE
CONVECTION IS ELSEWHERE WITHIN 50-100 NM ON EITHER SIDE OF THE
MONSOON TROUGH AND ITCZ.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL OMEGA TYPE RIDGE COVERS THE CONUS THIS MORNING
...GENERATING EASTERLY ZONAL FLOW ALOFT ACROSS THE GULF ON WATER
VAPOR IMAGERY. THIS PATTERN IS PROVIDING FAIR WEATHER CONDITIONS
AND LIGHT ANTI-CYCLONIC SURFACE FLOW AROUND A PAIR OF SURFACE
HIGHS CENTERED OVER THE NW BASIN NEAR 29N93W AND OVER THE FAR
EASTERN BASIN NEAR 28N83W. A SMALL CLUSTER OF SHOWERS AND
THUNDERSTORMS IS NOTED OFF THE COAST OF LOUISIANA ON DOPPLER
RADAR IMAGERY. THESE SHOWERS COULD LINGER THROUGHOUT THE DAY
BEFORE LIFTING N BY SAT NIGHT. SOME ISOLATED SHOWERS ARE MOVING
ACROSS THE FAR SE GULF AND FLORIDA STRAITS. THE MOISTURE AND
SHOWER ACTIVITY IN THIS REGION IS EXPECTED TO INCREASE AS A
TROPICAL WAVE IN THE NW CARIBBEAN CONTINUES TO MOVE WEST DURING
THE NEXT 24 HOURS. WEAK SURFACE RIDGING IS EXPECTED TO REMAIN
ACROSS THE BASIN THROUGH THE WEEKEND.

CARIBBEAN SEA...
HEAVY RAINFALL AND THUNDERSTORMS ACTIVITY COVER THE SW AND NW
BASINS W OF 80W ASSOCIATED WITH THE PASSAGE OF A TROPICAL WAVE
EXTENDING FROM WRN CUBA TO CENTRAL AMERICA ACROSS CENTRAL
HONDURAS. WHILE THE RAINSHOWER ACTIVITY OVER THE NW BASIN COULD
SEE SOME BREAKS IN BETWEEN...THE ACTIVITY OVER THE SW BASIN IS
EXPECTED TO REMAIN CONSTANT AND SLOWLY MOVE INLAND ACROSS
CENTRAL AMERICA...PROVOKING FLOODING AND POSSIBLE MUDSLIDES
DURING THE NEXT DAY OR SO. THE CENTRAL AND ERN CARIBBEAN ARE
EXPERIENCING MOSTLY FAIR WEATHER DUE TO A COMBINATION OF DRY AIR
ALOFT AND SAHARAN DUST ACROSS THESE REGIONS OF THE CARIBBEAN.
EASTERLY TRADEWIND FLOW OF 15-25 KT IS ACROSS MUCH OF THE BASIN
REACHING TO NEAR GALE FORCE CRITERIA IN THE CENTRAL CARIBBEAN
BETWEEN 70W-77W.

ATLANTIC OCEAN...
SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE MOVING ACROSS THE
BAHAMAS AND NRN COASTAL WATERS OF CUBA S OF 25N BETWEEN 72W-80W.
THIS AREA OF CONVECTION IS ASSOCIATED WITH THE NRN EXTENSION OF
A TROPICAL WAVE AXIS MOVING ACROSS THE WRN CARIBBEAN. A BROAD
AND STRONG 1031 MB HIGH PRESSURE SYSTEM CENTERED NNW OF THE
AZORES EXTENDS A SURFACE RIDGE AXIS TO THE WRN ATLC KEEPING FAIR
WEATHER CONDITIONS ELSEWHERE ACROSS THE REMAINDER OF THE
DISCUSSION AREA. THE FAIR WEATHER IS FURTHER ENHANCED BY A LARGE
AREA OF SAHARAN DUST EXTENDING FROM THE WEST AFRICA TO THE ERN
CARIBBEAN.

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

$$

GARCIA




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