000
AXNT20 KNHC 231702
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
205 PM EDT SUN OCT 23 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 
1645 UTC.

...SPECIAL FEATURES...

AT 1500 UTC...A 1007 MB LOW IS NEAR 15N81W. A DISSIPATING 
STATIONARY FRONT REMAINS N OF THIS LOW. SCATTERED MODERATE TO 
STRONG CONVECTION IS N OF THE LOW FROM 14N-20N BETWEEN 81W-85W 
TO INCLUDE NE NICARAGUA AND E HONDURAS. ENVIRONMENTAL CONDITIONS 
ARE GRADUALLY BECOMING MORE CONDUCIVE FOR DEVELOPMENT OF THIS 
SYSTEM AND A TROPICAL DEPRESSION COULD FORM WITHIN THE NEXT 48 
HOURS AS IT MOVES SLOWLY NORTHWESTWARD. REGARDLESS OF 
DEVELOPMENT... LOCALLY HEAVY RAINS AND GUSTY WINDS WILL 
CONTINUE TO AFFECT PORTIONS OF HONDURAS AND NICARAGUA THROUGH 
MONDAY. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS 
PRESENTLY INBOUND TO INVESTIGATE THIS DISTURBANCE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 13N16W CONTINUING ALONG 12N28W 7N38W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM 7N-15N BETWEEN 20W-30W...AND FROM 
4N-15N BETWEEN 30W-45W. A SURFACE TROUGH IS ANALYZED FROM 16N39W 
TO 13N46W WITH WIDELY SCATTERED MODERATE CONVECTION S OF THE 
TROUGH AXIS. A 1008 MB LOW IS OFF THE COAST OF SOUTH AMERICA 
NEAR 10N55W WITH SCATTERED MODERATE CONVECTION WITHIN 60 NM OF 
THE CENTER.

...DISCUSSION...

GULF OF MEXICO...
A 1022 MB HIGH IS CENTERED OVER E TENNESSEE NEAR 36N84W. A 
SURFACE RIDGE AXIS EXTENDS SW TO THE NW GULF OF MEXICO. 5-10 KT 
ANTICYCLONIC SURFACE WINDS ARE NOTED OVER THE GULF. SOME 
ISOLATED SHOWERS ARE OVER THE BAY OF CAMPECHE WHILE THE 
REMAINDER OF THE GULF HAS FAIR WEATHER. IN THE UPPER LEVELS... 
ZONAL FLOW PERSISTS WITH STRONG SUBSIDENCE. EXPECT IN 24 HOURS 
FOR A SURFACE TROUGH TO ENTER THE NW GULF WITH ISOLATED SHOWERS. 
ALSO EXPECT AN UPPER LEVEL TROUGH TO BE OVER THE N GULF IN 24 
HOURS.   

CARIBBEAN SEA...
A SPECIAL FEATURE LOW IS CENTERED OVER THE W CARIBBEAN. SEE 
ABOVE. A DISSIPATING STATIONARY FRONT STILL LINGERS FROM CENTRAL 
CUBA TO NEAR THE CAYMAN ISLANDS ALONG 22N78W 19N83W. SCATTERED 
SHOWERS ARE NOTED S OF JAMAICA...ALONG THE COAST OF NW 
VENEZUELA...AND OVER CENTRAL AMERICA FROM PANAMA TO HONDURAS. 
FURTHER E...ISOLATED MODERATE CONVECTION IS OVER THE WINDWARD 
ISLANDS FROM 13N-16N BETWEEN 58W-62W. EXPECT OVER THE NEXT 24 
HOURS FOR LITTLE CHANGE OVER THE W CARIBBEAN AND CENTRAL AMERICA 
WHILE THE CONVECTION OVER THE WINDWARD ISLANDS SPREADS W.
 
ATLANTIC OCEAN...
A STATIONARY FRONT IS OVER THE W ATLANTIC FROM 30N71W TO 27N76W 
TO CENTRAL CUBA AT 22N78W. SCATTERED SHOWERS ARE WITHIN 120 NM W 
OF THE FRONT TO INCLUDE THE N BAHAMAS. A 1025 MB HIGH IS OVER 
THE CENTRAL ATLANTIC NEAR 37N44W PRODUCING FAIR WEATHER. IN THE 
UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED NEAR 25N61W. 
WIDELY SCATTERED SHOWERS ARE FROM 23N-33N BETWEEN 59W-64W. 
EXPECT OVER THE NEXT 24 HOURS FOR THE FRONT OVER THE W ATLANTIC 
TO DISSIPATE TO A SURFACE TROUGH. ALSO EXPECT THE TROPICAL LOW 
NEAR 10N55W TO MOVE NW TO THE S WINDWARD ISLANDS WITH CONTINUED 
CONVECTION. 

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

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FORMOSA