[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 170004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE AUG 16 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2345 UTC.

...TROPICAL WAVES...

TROPICAL WAVE W OF CAPE VERDE ISLANDS IS FROM 18N27W TO 12N27W
CONTINUES MOVING WESTWARD AT APPROXIMATELY 15 KT. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THAT THIS WAVE CONTINUES
EMBEDDED WITHIN A HIGH MOISTURE REGION THAT EXTENDS FROM 12N-18N
BETWEEN 23W-31W...HOWEVER...NO SIGNIFICANT PRECIPITATION IS
ASSOCIATED TO IT.

TROPICAL WAVE IS MOVING W ACROSS THE CENTRAL CARIBBEAN ALONG
18N66W TO 12N67W AT 20 KT. MID LEVEL CYCLONIC TURNING IS VERY
WELL OBSERVED ALONG THE WAVE AXIS. NUMEROUS MODERATE TO STRONG
CONVECTION IS FROM 15N-18N BETWEEN 66W-72W.

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

THE MONSOON TROUGH EXTENDS FROM THE W AFRICAN COAST NEAR 21N17W
AND THEN SW TO 11N30W 8N42W...THE ITCZ CONTINUES FROM THERE TO
THE COAST OF FRENCH GUIANA NEAR 5N52W. CLUSTERS OF MODERATE
CONVECTION ARE FROM 9N-12N BETWEEN 21W-25W. CLUSTERED MODERATE
TO STRONG CONVECTION IS FROM 7N-9N BETWEEN 29W-38W. ANOTHER
REGION OF MODERATE CONVECTION IS FROM 6N-11N BETWEEN 43W-49W.

...DISCUSSION...

GULF OF MEXICO...
A LONGWAVE UPPER LEVEL TROUGH IS MOVING EWD WITH AXIS NEAR 81W.
THIS IS SUPPORTING A NEARLY STATIONARY FRONT THAT EXTENDS FROM
30N78W ENTERING THE FLORIDA E COAST NEAR 29N81W...IT MOVES FROM
THE W FLORIDA COAST NEAR 28N82W AND CONTINUES WESTWARD ENTERING
LOUISIANA COAST NEAR 29N90W. PRE-FRONTAL MODERATE TO ISOLATED
STRONG CONVECTION IS OCCURRING PARALLEL TO THE FRONT WITHIN 140
NM. THE REMAINDER OF THE BASIN IS UNDER WEAK SURFACE RIDGING
AROUND A 1015 MB HIGH IN THE NW GULF NEAR 28N93W. ALOFT...UPPER
LEVEL RIDGING COVERS THE WRN GULF AROUND AN UPPER LEVEL HIGH
CENTERED OVER SRN NEW MEXICO NEAR 32N106W. IN 24 HOURS THE HIGH
PRESSURE SYSTEM IS EXPECTED TO REMAIN NEARLY STATIONARY WHILE
THE FRONTAL SYSTEM WILL CONTINUE MOVING SLOWLY EASTWARD.

CARIBBEAN SEA...
ISOLATED SHOWERS/THUNDERSTORMS IN THE NW CARIBBEAN ARE
ASSOCIATED WITH A SURFACE TROUGH THAT IS CROSSING CENTRAL CUBA
AND PRODUCING HEAVY PRECIPITATION TO THE SE OF THE ISLAND.
THE CENTRAL AND EASTERN CARIBBEAN ARE IN A HIGH MOISTURE
ENVIRONMENT AS SHOWN BY THE WATER VAPOR IMAGERY...MOSTLY
ASSOCIATED TO A TROPICAL WAVE LOCATED ALONG 18N66W TO 12N67W.
NUMEROUS MODERATE STRONG CONVECTION ASSOCIATED TO THIS WAVE IS
FROM 15N-18N BETWEEN 66W-72W. ALOFT...WEAK UPPER RIDGING REMAINS
FROM CENTRAL TO WESTERN CARIBBEAN. IN 24 HOURS THE WAVE WILL
CONTINUE MOVING WESTWARD WITH THE TRADE WINDS BRINGING MORE
PRECIPITATION TO LA HISPANIOLA AND EASTERN CUBA.

ATLANTIC OCEAN...
A NEARLY STATIONARY FRONT IS IN THE W ATLANTIC EXTENDING FROM
30N78W AND ENTERING THE FLORIDA E COAST NEAR 29N81W. PRE-FRONTAL
SHOWERS ARE WITHIN 100 NM. SCATTERED SHOWERS ARE OVER THE
CENTRAL BAHAMAS ASSOCIATED TO THE SURFACE TROUGH MENTIONED IN THE
CARIBBEAN DISCUSSION. SURFACE RIDGING DOMINATES THE CENTRAL AND
EASTERN ATLANTIC N OF 20N...AT THE UPPER LEVEL WATER VAPOR
IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE SUPPORTING FAIR
WEATHER CONDITIONS FOR THIS REGION. THIS PATTERN IS EXPECTED TO
CONTINUE IN THE NEXT 24 HOURS.

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

$$
RAMOS/GARCIA





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