000
AXNT20 KNHC 051137
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT MON SEP 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...SPECIAL FEATURES...

HURRICANE KATIA IS CENTERED NEAR 23.9N 62.0W AT 05/0900 UTC OR 
ABOUT 350 NM N OF THE NORTHERN LEEWARD ISLANDS AND ABOUT 525 
NM S-SE OF BERMUDA MOVING NW AT 10 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 972 MB. MAXIMUM SUSTAINED WIND SPEED IS 85 KT WITH 
GUSTS TO 105 KT. PLEASE SEE THE LATEST INTERMEDIATE PUBLIC 
ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT2/WTNT32 KNHC AND THE 
FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT2/WTNT22 
KNHC FOR MORE DETAILS. SCATTERED STRONG CONVECTION IS FROM 
22N-24N BETWEEN 62W-64W WITH SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION COVERING THE REMAINDER OF THE AREA FROM 21N-27N 
BETWEEN 60W-65W. 

...TROPICAL WAVES...
TROPICAL WAVE IS IN THE E TROPICAL ATLC EXTENDING FROM 15N29W TO 
5N27W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN AN AREA OF 
DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER 
IMAGERY. SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN 120 NM W 
OF THE WAVE AXIS BETWEEN 10N-13N WITH CLUSTERS OF SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION COVERING THE REMAINDER OF 
THE AREA FROM 4N-13N BETWEEN 27W-34W. 

TROPICAL WAVE IS IN THE CENTRAL TROPICAL ATLC EXTENDING FROM 
19N45W TO 14N42W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN AN 
AREA OF DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL 
PRECIPITABLE WATER IMAGERY WITH DRIER AIR UNDERCUTTING THE WAVE 
AXIS. WAVE REMAINS LOCATED AT THE BASE OF AN UPPER TROUGH WHICH 
IS GENERATING SHOWER/THUNDERSTORM ACTIVITY NOT ASSOCIATED WITH 
THE WAVE ITSELF. 

...THE ITCZ/THE MONSOON TROUGH...
THE MONSOON TROUGH IS ANALYZED ACROSS AFRICA ENTERING THE E 
TROPICAL ATLC NEAR DAKAR SENEGAL TO 13N21W. THE ITCZ AXIS IS 
ANALYZED FROM 8N48W 9N52W TO GUYANA SOUTH AMERICA. CLUSTERS OF 
SCATTERED MODERATE CONVECTION ARE FROM 3N-9N BETWEEN 12W-18W.

...DISCUSSION...

GULF OF MEXICO...
THE REMNANTS OF LEE CONTINUES TO GENERATE BANDS OF SCATTERED/ 
HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS OVER THE GULF N OF 24N 
E OF 91W AND INLAND OVER THE N GULF COAST E OF CENTRAL LOUISIANA 
TO NE FLORIDA. AT 05/0900 UTC A COLD FRONT ENTERS THE GULF 
WATERS NEAR VERMILION BAY LOUISIANA TO INLAND OVER TEXAS JUST S 
OF CORPUS CHRISTI WHERE IT BECOMES NEAR STATIONARY ACROSS S 
TEXAS WITH A SURFACE TROUGH EXTENDING INTO THE GULF WATERS JUST 
E OF ATCHAFALAYA BAY LOUISIANA ALONG 27N92W TO 24N95W. SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF 
THE SURFACE TROUGH. AN UPPER TROUGH COVERS THE W GULF WHILE AN 
UPPER RIDGE DOMINATES THE E GULF. THE MONSOON TROUGH IS ANALYZED 
ALONG THE S COAST OF CENTRAL AMERICA AND MEXICO BETWEEN EL 
SALVADOR TO NEAR ACAPULCO MEXICO GENERATING SCATTERED SHOWERS/ 
THUNDERSTORMS INLAND AND IN THE BAY OF CAMPECHE S OF 23N BETWEEN 
91W-95W. THE COLD FRONT WILL DIG SE THROUGH THE W GULF TODAY AND 
BECOME STATIONARY FROM NE GULF TO BAY OF CAMPECHE WED THROUGH 
FRI. 

CARIBBEAN SEA...
AN INVERTED TROUGH AXIS EXTENDS FROM AN UPPER LOW OVER THE TIP 
OF NICARAGUA/HONDURAS TO THE WINDWARD PASSAGE GIVING THE NW 
CARIBBEAN NE FLOW ALOFT GENERATING ISOLATED CLUSTERS OF 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N TO THE COAST 
OF CUBA BETWEEN 80W-85W. THE MONSOON TROUGH IS ANALYZED ACROSS 
THE SW CARIBBEAN FROM COLOMBIA NEAR 11N75W ACROSS NICARAGUA NEAR 
12N84W GENERATING ISOLATED CLUSTERS OF ISOLATED SHOWERS/ 
THUNDERSTORMS W OF LINE FROM 17N80W TO COLOMBIA NEAR 11N74W. DRY 
STABLE AIR ALOFT DOMINATES THE E CARIBBEAN ESPECIALLY E OF 73W. 
THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER CLEAR SKIES 
THIS MORNING. WHILE HURRICANE KATIA CONTINUES TO MOVE NW AWAY 
FROM TROPICAL ATLC. THE CENTRAL ATLC TROPICAL WAVE WILL MOVE 
INTO THE E CARIBBEAN LATE WED AND INTO THE CENTRAL CARIBBEAN BY 
FRI. 
 
ATLANTIC OCEAN...
LARGE SWELLS GENERATED BY HURRICANE KATIA ARE EXPECTED TO AFFECT 
MOST OF THE EAST COAST OF THE UNITED STATES...BERMUDA...THE 
GREATER ANTILLES...AND EAST FACING BEACHES OF THE BAHAMAS DURING 
THE NEXT FEW DAYS. THESE SWELLS ARE LIKELY TO CAUSE LIFE 
THREATENING SURF AND RIP CURRENT CONDITIONS. PLEASE CONSULT 
PRODUCTS ISSUED BY LOCAL NATIONAL WEATHER SERVICE OFFICES FOR 
MORE INFORMATION. THE W ATLC IS DOMINATED BY NORTHERLY FLOW IN 
RESPONSE TO THE UPPER RIDGE OVER THE E GULF OF MEXICO. CLUSTERS 
OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 28N W OF 
79W TO THE COAST OF FLORIDA. THE UPPER RIDGE ASSOCIATED WITH 
HURRICANE KATIA COVERS THE REMAINDER OF THE W ATLC INTO THE 
CENTRAL ATLC. AN UPPER TROUGH COVERS THE E ATLC INTO THE TROPICS 
WITH THE AXIS EXTENDING FROM AN UPPER LOW NEAR 31N25W SW TO 
16N41W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AT THE BASE 
OF THE UPPER TROUGH FROM 12N-17N BETWEEN 37W-44W. A SURFACE 
RIDGE DOMINATES THE E AND CENTRAL ATLC MAINLY N OF 20N WITH A 
WEAKNESS SURROUNDING HURRICANE KATIA AND ANCHORED BY A 1023 MB 
HIGH NEAR 33N51W. HURRICANE KATIA WILL CONTINUE TO MOVE THROUGH 
THE W ATLC THROUGH WED MOVING N OF THE AREA THU MORNING. 

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

$$
PAW