[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211158
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN AUG 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...SPECIAL FEATURE...

TROPICAL STORM IRENE IS CENTERED NEAR 16.5N 62.0W AT 21/1200 UTC
OR ABOUT 35 MI...55 KM WNW OF GUADELOUPE...OR ABOUT 45 MI...70
KM SSW OF ANTIGUA MOVING W AT 19 KT. THE ESTIMATED MINIMUM
CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 45
KT WITH GUSTS TO 55 KT. PLEASE SEE THE LATEST INTERMEDIATE
PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT4/ WTNT34 KNHC
AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT4/
WTNT24 KNHC FOR MORE DETAILS. SCATTERED STRONG CONVECTION COVERS
A BROAD REGION OF THE ATLC AND EAST CARIBBEAN BASIN FROM 14N-21N
BETWEEN 57W-65W. IRENE IS EXPECTED TO PRODUCE TOTAL RAINFALL
ACCUMULATIONS OF 4 TO 7 INCHES IN THE LEEWARD ISLANDS...PUERTO
RICO AND THE VIRGIN ISLANDS...WITH ISOLATED MAXIMUM AMOUNTS OF
UP TO 10 INCHES. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH
FLOODS AND MUDSLIDES IN AREAS OF STEEP TERRAIN. TROPICAL STORM
CONDITIONS ARE EXPECTED TO BEGIN THIS AFTERNOON IN THE VIRGIN
ISLANDS AND PUERTO RICO. HURRICANE CONDITIONS ARE POSSIBLE OVER
THE DOMINICAN REPUBLIC BY LATE MONDAY WITH TROPICAL STORM
CONDITIONS POSSIBLE BY MONDAY AFTERNOON.

TROPICAL DEPRESSION HARVEY IS CENTERED INLAND ABOUT 60 MI...95
KM ESE OF VILLAHERMOSA MEXICO...OR ABOUT 100 MI...160 KM NE OF
TUXTLA GUTIERREZ MEXICO NEAR 17.7N 92.0W AT 21/0900 UTC MOVING W
AT 13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB.
MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT.
PLEASE SEE THE LATEST INTERMEDIATE PUBLIC ADVISORY UNDER
AWIPS/WMO HEADER MIATCPAT3/WTNT33 KNHC AND THE FULL
FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT3/ WTNT23 KNHC
FOR MORE DETAILS. ALTHOUGH MOST OF THE HEAVY AND STRONG
CONVECTION IS INLAND OVER CENTRAL AMERICA A SOUTHERN
MEXICO...SCATTERED SHOWERS AND THUNDERSTORMS LINGER OVER THE NW
CARIBBEAN N OF 15N W OF 81W TO THE COAST OF THE YUCATAN. HARVEY
IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 3 TO 6
INCHES ACROSS GUATEMALA...WRN HONDURAS...AND THE YUCATAN
PENINSULA...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 10 INCHES.
THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND
MUDSLIDES...ESPECIALLY OVER HIGHER TERRAIN.

...THE ITCZ/THE MONSOON TROUGH...

DUE TO THE BROAD CYCLONIC WIND FIELD ASSOCIATED TO T.S. IRENE IN
THE SPECIAL FEATURES AND THE MONSOON TROUGH REACHING AS FAR WEST
AS 45W FROM THE COAST OF AFRICA...THERE IS NO CONVERGENCE OF NE
AND SE TRADE WINDS...THUS THERE IS NO ITCZ DEPICTED ON THE 0600
UTC SURFACE ANALYSIS. THE MONSOON TROUGH EXTENDS FROM THE COAST
OF MAURITANIA NEAR 19N16W ALONG A BROAD ELONGATED 1007 MB LOW
WEST OF CAPE VERDE ISLANDS NEAR 16N28W TO 10N35W TO 11N45W.
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 12N-18N
BETWEEN 23W-30W. SIMILAR CONVECTION IS FROM 5N-10N BETWEEN
33W-53W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER OMEGA RIDGE PATTERN IS SETTLED ACROSS THE CONUS
...AND CONTINUES TO INFLUENCE MOST OF THE GULF OF MEXICO THIS
MORNING...PROVIDING A DRY SUBSIDENT AIRMASS ALOFT ACROSS THE NRN
AND WRN AREAS OF THE GULF ON WATER VAPOR IMAGERY. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE OVER THE FAR E...SE...AND
S CENTRAL BASINS E OF A LINE EXTENDING FROM 30N85W TO 21N90W
ASSOCIATED TO WEAK INVERTED MID LEVEL TROUGHINESS EXTENDING NE
FROM T.D. HARVEY. SIMILAR CONVECTION IS OVER THE BAY OF CAMPECHE
ALSO ASSOCIATED TO THE OUTER CONVECTION OF T.S. HARVEY. THE
REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES WITH A FEW
ISOLATED WEAK SHOWERS DOTTING THE BASIN. THE WEAK SURFACE RIDGE
IS EXPECTED TO PREVAIL ACROSS THE N GULF THROUGH WEDNESDAY.

CARIBBEAN SEA...
THE PRIMARY CONCERN THIS MORNING IS T.S. IRENE MOVING ACROSS THE
NORTHERN LESSER ANTILLES. THIS SYSTEM IS PRODUCING SIGNIFICANT
CONVECTION OVER THE NE CARIBBEAN BASIN. FOR MORE INFORMATION SEE
SPECIAL FEATURES ABOVE. WIDELY SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS REMAIN OVER THE NW BASIN N OF 15N W OF 81W IN THE
WAKE OF T.D. HARVEY. SIMILAR ACTIVITY IS IN THE SW BASIN NEAR
THE COAST OF COLOMBIA AND PANAMA BETWEEN 75W-83W DUE TO CLOSE
PROXIMITY TO THE MONSOON TROUGH EXTENDING INLAND ACROSS PANAMA
TO NORTHERN COLOMBIA. THE REMAINDER OF THE CARIBBEAN UNDER
MOSTLY CLEAR SKIES WITH A FEW ISOLATED SHOWERS EMBEDDED IN THE
5-15 KT EASTERLY TRADE WIND FLOW. AS HARVEY CONTINUES TO WEAKEN
INLAND OVER MEXICO...T.S. IRENE IS FORECAST TO MOVE INTO NE
CARIBBEAN TODAY...THEN TO NEAR THE WINDWARD PASSAGE ON TUESDAY.

ATLANTIC OCEAN...
THE PRIMARY CONCERN THIS EVENING IS T.S. IRENE MOVING ACROSS THE
NORTHERN THE LESSER ANTILLES. SEE SPECIAL FEATURES ABOVE FOR
MORE INFORMATION ON IRENE. OTHERWISE...AN UPPER LEVEL TROUGH
SLOWLY MOVES OFF THE EASTERN CONUS SEABOARD GENERATING ISOLATED
SHOWERS AND POSSIBLE THUNDERSTORMS N OF 21N W OF 70W. THE
REMAINDER OF THE ATLC BASIN IS DOMINATED BY A BROAD SURFACE
RIDGE ANCHORED BY A 1025 MB HIGH W OF THE AZORES NEAR 37N35W...
LEAVING THE REMAINDER OF THE DISCUSSION AREA N OF 21N UNDER FAIR
CONDITIONS THIS MORNING. LONG RANGE COMPUTER MODELS SUGGEST
IRENE WILL MOVE ACROSS THE WINDWARD PASSAGE ON TUESDAY...TO OVER
CUBA ON WEDNESDAY AND THE STRAITS OF FLORIDA ON THURSDAY.

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

$$

GARCIA




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