[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051733
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE JUL 05 2011

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 20N42W
TO 11N47W MOVING W 15-20 KT. WAVE IS WELL DEFINED IN THE LOW
LEVEL SATELLITE DERIVED WINDS. WAVE IS PRECEDING A BROAD
AMPLITUDE MOISTURE SURGE INDICATED ON THE TOTAL PRECIPITABLE
WATER IMAGERY. CONVECTION IS LIMITED DUE TO A DRY SLOT WRAPPING
AROUND THE NORTHERN HALF OF THE WAVE AXIS.

TROPICAL WAVE IS MOVING ACROSS THE NW CARIBBEAN MOVING WNW AT
ABOUT 10-15 KT. WAVE REMAINS EMBEDDED WITHIN A BROAD AREA OF
DEEP LAYERED MOISTURE THAT COVERS MOST OF THE N CENTRAL AND NW
CARIBBEAN BASIN. THE WAVE LIES UNDERNEATH AN AREA OF DIFFLUENCE
ALOFT WHICH IS HELPING SUPPORT CONVECTION NEAR THE WAVE. EARLIER
ASCAT DATA INDICATED A SHARP CYCLONIC TURNING EAST OF THE
CURRENT WAVE AXIS...AND THEREFORE...THE WAVE IS NOW REANALYZED
FROM 22N81W TO 15N85W. SCATTERED MODERATE TO STRONG CONVECTION
IS WITHIN 150/200 NM EITHER SIDE OF THE WAVE AXIS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS INLAND OVER AFRICA AND ENTERS THE
EAST TROPICAL ATLC THROUGH SENEGAL FROM 14N17W TO 10N22W. THE
ITCZ AXIS STARTS FROM 10N22W CONTINUING WSW ALONG 7N30W 6N38W.
SCATTERED WEAK TO MODERATE CONVECTION IS WITHIN 100/130 NM ON
EITHER SIDE OF THE ITCZ BETWEEN 25W-35W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER LEVEL CYCLONIC FLOW COVERS THE DISCUSSION AREA THIS
AFTERNOON CENTERED NEAR 26N90W. THIS FEATURE SUPPORTS A SURFACE
TROUGH AXIS ANALYZED FORM 27N88W TO 24N88W. SCATTERED WEAK
SHOWERS ARE WITHIN 50/80 E OF THE AXIS. SCATTERED HEAVY SHOWERS
AND ISOLATED THUNDERSTORMS ARE S OF 26N E OF 85W...ASSOCIATED TO
A TROPICAL WAVE CURRENTLY MOVING ACROSS THE NW CARIBBEAN. THIS
ACTIVITY IS FURTHER ENHANCED BY DIFLUENT FLOW ALOFT COVERING THE
SE GULF AND NW CARIBBEAN BASINS. THE REMAINDER OF THE BASIN IS
UNDER DRY AIR ALOFT AND A VERY WEAK SURFACE PRESSURE GRADIENT
YIELDING LIGHT WINDS. EXPECT THE SURFACE TROUGH TO CONTINUE TO
DRIFT W WITH LIMITED CONVECTION OVER THE NEXT 24 HOURS...AND THE
TROPICAL WAVE AXIS TO START MOVING INTO THE SE GULF DURING THE
TIME PERIOD.

CARIBBEAN SEA...
THE UPPER LEVELS OF THE CARIBBEAN SEA ARE DOMINATED BY
ANTICYCLONIC FLOW CENTERED NEAR 16N75W. THIS FLOW BECOMES
DIFFLUENT OVER THE NW BASIN BETWEEN THE UPPER LOW OVER THE GULF
AND THE UPPER HIGH OVER THE CARIBBEAN. HOWEVER...AT SURFACE...
SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE OVER THE N CENTRAL
AND NW CARIBBEAN...INCLUDING INLAND PORTIONS OVER THE GREATER
ANTILLES AND CENTRAL AMERICA N OF 15N W OF 68W...DUE TO A
TROPICAL WAVE MOVING ACROSS THE NW BASIN...AND A BROAD AREA OF
DEEP LAYER MOISTURE OVER THE N CENTRAL BASIN. SIMILAR ACTIVITY
IS FOUND OVER THE FAR SW BASIN WITHIN 100 NM OFF THE COAST OF
PANAMA AND COSTA RICA...ASSOCIATED TO THE MONSOON TROUGH
EXTENDING ACROSS SOUTHERN NICARAGUA INTO NORTHERN COLOMBIA. FAIR
WEATHER CONDITIONS ARE ELSEWHERE ACROSS THE CARIBBEAN INFLUENCED
BY DRY AIR ALOFT ASSOCIATED TO THE SUBSIDENCE GENERATED BY THE
UPPER HIGH. A SURFACE TROUGH LOCATED 80 NM SE OF TRINIDAD AND
TOBAGO WILL BRING MODERATE TO STRONG CONVECTION TO THE FAR SE
BASIN OVER THE NEXT 6-12 HOURS.

ATLANTIC OCEAN...
A SURFACE TROUGH IS MOVING ACROSS THE BAHAMAS...ANALYZED FROM
27N74W TO 21N77W. CLUSTERS OF SCATTERED HEAVY SHOWERS AND
THUNDERSTORMS ARE S OF 27N BETWEEN 68W-77W. THE CONVECTION TO
THE NW OF THE TROUGH AXIS IS VERY LIMITED DUE TO AN UPPER LEVEL
RIDGE OVER THE WEST ATLC. A WEAK UPPER LEVEL LOW IS NEAR 27N64W
ENHANCING THE CONVECTION ASSOCIATED TO THE SURFACE TROUGH AND...
AT THE SAME TIME SHEARING IT TO THE NE. THE SURFACE TROUGH IS
EXPECTED TO CONTINUE TO TRACK NW ACROSS THE NORTHERN BAHAMAS AND
THE EASTERN COASTAL WATERS OF THE FLORIDA PENINSULA WITH
CONVECTION OVER THE NEXT 24-48 HOURS. THE REMAINDER OF THE ATLC
IS DOMINATED BY A BROAD RIDGE ANCHORED BY A 1030 MB HIGH NEAR
35N37W. THIS BROAD SYSTEM IS PROVIDING MOSTLY FAIR WEATHER
ACROSS THE CENTRAL AND EAST ATLC. ANOTHER UPPER LOW IS EMBEDDED
IN THE BROAD RIDGE SPINNING NEAR 25N50W SUPPORTING A WEAK
SURFACE TROUGH ANALYZED FROM 26N50W TO 24N52W WITHOUT ANY
SIGNIFICANT CONVECTION.

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

$$

GARCIA




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