[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 130001
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU JUN 12 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.

...TROPICAL WAVES...
A HIGH AMPLITUDE TROPICAL WAVE CAME OFF THE COAST OF AFRICA
EARLIER THIS AFTERNOON. ITS AXIS EXTENDS FROM 15N18W TO 3N18W.
THE NORTHERN AND CENTRAL PORTION OF THE WAVE IS EMBEDDED IN A
SAHARAN AIR LAYER OUTBREAK...THUS THE CONVECTION IS BEING
LIMITED TO THE SOUTHERN PORTION OF THE WAVE. ISOLATED MODERATE
CONVECTION IS FROM 2N-5N WITHIN 140 NM WEST OF THE WAVE AXIS.

A LOW AMPLITUDE TROPICAL WAVE IS EMBEDDED IN THE ITCZ WITH AXIS
EXTENDING FROM 8N36W TO 1N36W. DRY AIR FROM A SAHARAN AIR LAYER
OUTBREAK ENGULFS THE NORTHERN PORTION OF THE WAVE. SCATTERED
MODERATE CONVECTION IS FROM 1N-6N BETWEEN 34W-38W.

A SECOND HIGH AMPLITUDE TROPICAL WAVE IS SE OF THE WINDWARD
ISLANDS WITH AXIS EXTENDING FROM 15N54W TO 1N55W MOVING WEST
NEAR 15 KT. THE WAVE IS ON THE WESTERN PERIPHERY OF A SAHARAN
AIR LAYER OUTBREAK...HOWEVER DUST AND DRY AIR EXTENDS INTO THE
WAVE ENVIRONMENT...THUS SUPPORTING THE LACK OF CONVECTION.

A FOURTH TROPICAL WAVE IS CROSSING PANAMA WITH AXIS EXTENDING
FROM 13N78W TO 4N78W MOVING W NEAR 20 KT. SCATTERED MODERATE
CONVECTION AND ISOLATED TSTMS ARE S OF 11N W OF 80W AS WELL N OF
3N E OF 82W AND OVER PANAMA. ELSEWHERE...STRONG DEEP LAYER
ENVIRONMENTAL WIND SHEAR HINDERS CONVECTION.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF SENEGAL
NEAR 12N15W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS
FROM 8N20W TO 4N27W TO 3N34W. IT THEN RESUMES WEST OF A TROPICAL
WAVE NEAR 3N38W TO 1N50W. BESIDES THE CONVECTION ASSOCIATED WITH
THE TROPICAL WAVES...ISOLATED SHOWERS ARE FROM 2N-6N BETWEEN 22W-
27W AS WELL AS FROM 2N-5N W OF 42W.

...DISCUSSION...

GULF OF MEXICO...
A MID-UPPER LEVEL RIDGE COVERS THE CENTRAL AND WESTERN GULF AND
PROVIDES NORTHWESTERLY FLOW ALOFT. FARTHER EAST...A DEEP LAYER
TROUGH CONTINUE TO SUPPORT SCATTERED HEAVY SHOWERS AND TSTMS S
OF 27N E OF 88W AS WELL AS OVER NORTHERN AND CENTRAL-EASTERN
FLORIDA. SCATTERED SHOWERS ARE NOTED ON THE FLORIDA STRAITS.
SCATTERED SHOWERS AND TSTMS ARE ALSO N OF 28N BETWEEN 90W-
95W...COINCIDING WITH AN AREA OF DIFFLUENT FLOW ALOFT.
OTHERWISE...OVERALL DRY AIR ACROSS THE GULF IS MAINTAINING
STABLE CONDITIONS. A SURFACE RIDGE AXIS EXTENDS FROM A PAIR OF
HIGH PRES LOCATED IN THE SW N ATLC INTO THE GULF AND PROVIDES SE
WIND FLOW OF 5-10 KT TO MOST OF THE BASIN. RIDGING AND MOSTLY
RETURN FLOW WILL PREVAIL DURING THE NEXT 48 HOURS.

CARIBBEAN SEA...
A MID-UPPER LEVEL TROUGH ACROSS THE EASTERN GULF OF MEXICO WITH
BASE EXTENDING INTO THE WESTERN CARIBBEAN IS SUPPORTING HEAVY
SHOWERS AND TSTMS ACROSS CUBA AND ADJACENT WATERS. FARTHER
EAST...MIDDLE TO UPPER LEVEL RIDGING IS GENERATING DIFFLUENT
FLOW ALOFT TO SUPPORT SCATTERED/ISOLATED SHOWERS AND TSTMS
ACROSS NW DOMINICAN REPUBLIC AND CENTRAL HAITI. A TROPICAL WAVE
IS MOVING OVER THE SW BASIN...SEE TROPICAL WAVE SECTION ABOVE.
OTHERWISE...A DRY AIRMASS ACROSS THE CENTRAL AND EASTERN BASIN
ALONG WITH STRONG DEEP LAYER ENVIRONMENTAL SHEAR SUPPORT FAIR
WEATHER. TRADES OF 15 KT PREVAILS ACROSS GREATER PORTIONS OF THE
BASIN EXCEPT FOR THE CENTRAL CARIBBEAN WHERE WINDS REACH A
MAXIMUM OF 20-30 KT DUE TO A TIGHTER PRESSURE GRADIENT BETWEEN A
LOW OVER COLOMBIA AND HIGH PRESSURE N OF THE AREA. A TROPICAL
WAVE WILL ENTER THE EASTERN CARIBBEAN WATERS BY SATURDAY
AFTERNOON.

...HISPANIOLA...
AN OVERALL DIFFLUENT ENVIRONMENT IS NOTED N-NW OF THE ISLAND ON
WATER VAPOR IMAGERY PROVIDING SUPPORT FOR SCATTERED SHOWERS AND
ISOLATED TSTMS OVER CENTRAL HAITI AND NW DOMINICAN REPUBLIC.
WEATHER CONDITIONS ARE EXPECTED TO IMPROVE OVER THE NEXT DAY OR
TWO INFLUENCED BY A DRY AIRMASS TO MOVE ACROSS THE ISLAND.

ATLANTIC OCEAN...
A MID-UPPER LEVEL TROUGH ACROSS THE EASTERN GULF AND FLORIDA
PENINSULA IS PROVIDING FOR AN UPPER LEVEL DIFFLUENT ENVIRONMENT
OVER THE SW N ATLC THUS SUPPORTING SCATTERED SHOWERS AND TSTMS W
OF 72W...INCLUDING THE BAHAMAS AND CUBA. OTHERWISE...THE SW
NORTH ATLC REMAINS FAIRLY TRANQUIL DUE TO SURFACE RIDGING
EXTENDING FROM 1021 MB HIGH PRES NEAR 27N65W AND A 1022 MB HIGH
NEAR 32N58W. FARTHER EAST...A MID-UPPER LEVEL TROUGH COVERS A
PORTION OF THE CENTRAL ATLC SUPPORTING A DISSIPATING STATIONARY
FRONT ANALYZED FROM 30N44W TO 26N50W TO 21N58W. OTHERWISE...A
1027 MB HIGH PRES NEAR 39N19W EXTENDS A RIDGE TO 23N47W.

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

$$
NR

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