[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220552
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN AUG 22 2010

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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...SPECIAL FEATURES...

TROPICAL DEPRESSION SIX IS CENTERED NEAR 11.3N 32.6W AT 22/0300
UTC OR LOCATED ABOUT 600 MILES WEST-SOUTHWEST OF THE
SOUTHERNMOST CAPE VERDE ISLANDS MOVING W-NW AT 08 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND
SPEED IS 30 KT WITH GUSTS TO 40 KT. STRENGTHENING IS FORECAST
OVER THE NEXT FEW DAYS AS THE CYCLONE REMAINS OVER WARM SEA
SURFACE TEMPERATURES AND WITHIN A RELATIVELY LOW NORTHEASTERLY
SHEAR ENVIRONMENT. THIS IS EXPECTED TO PROVIDE AN OVERALL
FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT FOR THE SYSTEM TO
MAINTAIN ORGANIZED CONVECTION AND PROVIDE FOR MINIMAL WIND
SHEAR. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION COVERS
A BROAD AREA FROM 5N-17N BETWEEN 25W-41W. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC
FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 11N46W TO 17N52W TO 24N53W MOVING W
AT 15-20 KT. WEAK CYCLONIC FLOW IS NOTED IN THE LOW-LEVEL CLOUD
FIELD ALONG THE WAVE AXIS. THIS SYSTEM MOVES ALONG WITH AN AREA
OF MODERATE VALUES OF DEEP LAYER MOISTURE OBSERVED ON THE TPW
IMAGERY. HOWEVER...MUCH OF THE MOISTURE TO THE EAST OF THE WAVE
IS POSITIONED BENEATH A STABLE SAHARAN AIR LAYER THAT COVERS
MUCH OF THE CENTRAL ATLC. NO SIGNIFICANT DEEP ORGANIZED
CONVECTION ACCOMPANIES THE WAVE... HOWEVER ISOLATED SHOWERS ARE
FROM 16N-25N BETWEEN 48W-55W.

TROPICAL WAVE EXTENDS FROM 18N69W TO 25N66W MOVING W AT 15-20
KT. THE WAVE COINCIDES WITH A MID-LEVEL TROUGH OVER THE W ATLC
BETWEEN 65W-74W. MAXIMUM TOTAL PRECIPITABLE WATER VALUES ARE
HIGHEST N OF 20N BETWEEN 61W-69W AS THIS MOISTURE CONTINUES TO
ADVECT NORTHWARD DUE TO A WEAKNESS IN THE SUBTROPICAL RIDGE
BETWEEN 70W-80W. ISOLATED MODERATE CONVECTION AND WIDELY
SCATTERED SHOWERS ARE OCCURRING FROM 20N-29N BETWEEN 62W-70W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 11N48W 10N57W...THEN RESUMES OVER
NORTHERN COLOMBIA NEAR 8N75W AND CONTINUES OVER CENTRAL AMERICA
ALONG 9N80W 14N90W. NO SIGNIFICANT CONVECTION IS OBSERVED NEAR
THE AXIS. THE GRADUAL DISSIPATION OF THE MONSOON TROUGH THAT HAS
PERSISTED OVER THE PAST SEVERAL DAYS OVER THE TROPICAL EASTERN
ATLC...IS ANALYZED AS A SURFACE TROUGH FROM NE OF T.D. SIX NEAR
15N28W TO 18N17W. HOWEVER...MOST OF THE CONVECTION IS ASSOCIATED
TO T.D. SIX. SCATTERED MODERATE TO STRONG CONVECTION IS MOVING
OFF THE W AFRICA COAST E OF 20W FROM 6N-16N.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION COVERS THE BASIN.
THIS UPPER LEVEL FEATURE IS PROVIDING A DRY EASTERLY FLOW ALOFT
OVER MUCH OF THE GULF. LOW TO MID-LEVEL INSTABILITY AND UPPER
LEVEL DIFFLUENCE PROVIDED BY THE UPPER LEVEL RIDGE IS GENERATING
SCATTERED SHOWERS AND TSTMS OVER THE EASTERN GULF E OF
85W...INCLUDING THE FLORIDA PENINSULA AND FAR WESTERN CUBA.
SCATTERED SHOWERS AND THUNDERSTORMS ARE ALSO OVER THE BAY OF
CAMPECHE S OF 20N. THIS ACTIVITY IS ASSOCIATED TO TROPICAL
DEPRESSION NINE-E CURRENTLY LOCATED ABOUT 110 NM S OF THE GULF
OF TEHUANTEPEC GENERATING BROAD CYCLONIC FLOW AND CONVECTION
THAT REACHES AS FAR NORTH AS THE BAY OF CAMPECHE. THE REMAINDER
OF THE GULF IS UNDER THE INFLUENCE OF THE EASTERN FLOW ALOFT
MENTIONED ABOVE AND THIS SUPPORTS A 1016 MB SURFACE HIGH
CENTERED OVER THE CENTRAL GULF NEAR 27N90W. CLEAR SKIES ARE
NOTED ELSEWHERE ON NIGHT VISION SATELLITE IMAGERY UNDER LIGHT
ANTICYCLONIC WINDS.

CARIBBEAN SEA...
CONVERGENT LOW-LEVEL SOUTHEASTERLY FLOW DOMINATES ACROSS THE
WESTERN CARIBBEAN W OF 79W S OF 18N...INCLUDING PORTIONS OF
CENTRAL AMERICA. THIS AREA OF CONVECTION IS MOVING AROUND AND
INTO THE BROAD CYCLONIC CIRCULATION GENERATED BY TROPICAL
DEPRESSION NINE-E CURRENTLY LOCATED OVER THE EASTERN PACIFIC
WATERS ABOUT 110 NM S OF THE GULF OF TEHUANTEPEC. AN ELONGATED
UPPER LEVEL LOW LOCATED NE OF THE BAHAMAS EXTENDS UPPER LEVEL
TROUGHINESS ACROSS HISPANIOLA...THE WINDWARD PASSAGE...AND
JAMAICA...CONTINUING WESTWARD TO NEAR 18N80W...GENERATING
SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 20 NM ON EITHER SIDE
OF THE UPPER LEVEL TROUGH AXIS. THE ITCZ AXIS EXTENDS ACROSS THE
FAR SW CARIBBEAN ALONG 11N AND IS ALSO PROVIDING LOW-LEVEL FOCUS
FOR SCATTERED SHOWERS AND ISOLATED TSTMS OVER PORTIONS OF COSTA
RICA AND PANAMA. WHILE MUCH OF THE EASTERN CARIBBEAN BETWEEN
64W-76W IS UNDER RELATIVELY CLEAR SKIES...A SURFACE TROUGH IS
OVER THE LESSER ANTILLES S OF 18N GENERATING SCATTERED SHOWERS
AND ISOLATED TSTMS E OF 64W.

ATLANTIC OCEAN...
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER MOST OF
THE WESTERN ATLC W OF 76W...PRODUCED BY UPPER LEVEL DIFFLUENT NE
FLOW AROUND AN ANTICYCLONIC CIRCULATION CENTERED OVER THE SE
CONUS AND AN ELONGATED UPPER LEVEL LOW LOCATED NE OF THE BAHAMAS
NEAR 24N72W. THE UPPER LEVEL LOW IS ALSO PROVIDING MOISTURE TO A
RATHER WEAK TROPICAL WAVE ALONG 68W...PRODUCING WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS FROM 20N-29N BETWEEN 62W-70W.
ELSEWHERE ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN
ATLC...SURFACE RIDGING DOMINATES THE ATLC N OF 25N ANCHORED BY A
1026 MB HIGH CENTERED NEAR 31N25W...MAINTAINING GENERALLY FAIR
WEATHER CONDITIONS E OF 62W.

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

$$

GARCIA




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