000
AXNT20 KNHC 302350
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE OCT 30 2012

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 
2315 UTC.

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

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL 
ATLC NEAR 14N17W CONTINUING ALONG 8N29W TO 9N35W. THE ITCZ 
EXTENDS FROM 8N42W TO SOUTH AMERICA NEAR 5N55W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 60 NM 
ALONG THE COAST OF GUINEA AND GUINEA-BISSAU AND WITHIN 150 NM S 
OF THE MONSOON TROUGH BETWEEN 22W-29W. CLUSTERS OF SCATTERED 
MODERATE CONVECTION ARE FROM THE ITCZ TO 14N BETWEEN 47W-55W. A 
WEAK SURFACE TROUGH EXTENDS FROM 14N38W TO 10N39W WITH A SECOND 
EQUALLY WEAK SURFACE TROUGH APPROACHING THE LESSER ANTILLES FROM 
15N57W TO 11N57W. NEITHER TROUGH IS PRODUCING ANY CONVECTION. 

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER PENNSYLVANIA 
TO 27N FROM THE MISSISSIPPI VALLEY INTO THE W ATLC. A SURFACE 
RIDGE DOMINATES THE GULF IN WAKE OF THE RECENT FRONTAL PASSAGE 
ANCHORED BY A 1020 MB HIGH NEAR 26N92W. DRY UPPER AIR CONTINUES 
TO WRAP AROUND THE BASE OF THE UPPER TROUGH GIVING MOST OF THE 
GULF FAIR WEATHER THIS EVENING. THE EXCEPTION IS SOME LOW LEVEL 
MOISTURE AND ISOLATED SHOWERS WITHIN 120 NM ALONG THE COAST OF 
MEXICO S OF BROWNSVILLE TEXAS W OF 93W. SURFACE RIDGE AND FAIR 
WEATHER WILL PREVAIL ACROSS THE GULF WED THROUGH THE WEEKEND. 

CARIBBEAN SEA...
SW FLOW ALOFT DOMINATES THE CARIBBEAN W OF 70W. AN UPPER RIDGE 
OVER THE TROPICAL ATLC EXTENDS OVER THE E CARIBBEAN ALONG 16N TO 
68W. THE UPPER TROUGH OVER THE GULF OF MEXICO AND W ATLC EXTENDS 
A COLD FRONT INTO THE CARIBBEAN ACROSS E CUBA NEAR 20N76W TO 
17N81W AND APPEARS TO BECOMING STATIONARY. A SURFACE TROUGH 
TRAILS THE FRONT ENTERING THE CARIBBEAN OVER CENTRAL CUBA NEAR 
22N81W TO 21N86W. NORTHERLY SURFACE FLOW COVERS THE NW CARIBBEAN 
IN WAKE OF THE FRONT. A SURFACE TROUGH IS IN THE E/CENTRAL 
CARIBBEAN EXTENDING FROM 17N70W TO THE COAST OF COLOMBIA NEAR 
11N73W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 
150/180 NM EITHER SIDE OF THE TROUGH AXIS. THE SURFACE TROUGH 
WILL CONTINUE TO TRACK WESTWARD WITH A LOW PRESSURE FORMING OVER 
THE S PART OF THE TROUGH WHEN IT REACHES THE SW CARIBBEAN WED. 
THE LOW WILL LINGER THERE THROUGH SAT BEFORE DISSIPATING SUN.

ATLANTIC OCEAN...
BROAD UPPER TROUGH THAT COVERS THE GULF OF MEXICO EXTENDS OVER 
THE W ATLC W OF 70W SUPPORTING A COLD FRONT THAT ENTERS THE 
REGION NEAR 32N67W ALONG 26N71W CROSSING CUBA INTO THE CARIBBEAN 
NEAR 20N76W. A SURFACE TROUGH TRAILS THE FRONT EXTENDING THROUGH 
32N73W ALONG 26N77W INTO THE N CARIBBEAN ACROSS CUBA NEAR 
22N81W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 30 NM ALONG THE 
FRONT. AN UPPER RIDGE OVER THE W TROPICAL ATLC EXTENDS AN AXIS 
OVER THE CENTRAL ATLC ALONG 21N58W TO BEYOND 32N57W WITH A WEAK 
1016 MB SURFACE HIGH IS LOCATED NEAR 23N60W. THIS UPPER RIDGE IS 
ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120 NM 
OF LINE FROM 23N64W INTO THE CARIBBEAN ACROSS PUERTO RICO AND 
HISPANIOLA NEAR 18N68W. AN UPPER TROUGH IS OVER THE E ATLC N OF 
20N BETWEEN 20W-45W SUPPORTING A COLD FRONT THAT ENTERS THE 
DISCUSSION AREA NEAR 32N16W W OF THE CANARY ISLANDS ALONG 26N24W 
TO 19N40W WITH SCATTERED SHOWERS WITHIN 75 NM E OF THE FRONT N 
OF 24N. A SURFACE TROUGH EXTENDS FROM 21N32W TO 16N39W WITH 
SCATTERED SHOWERS WITHIN 60 NM E OF THE TROUGH AXIS. A SERIES OF 
SURFACE TROUGHS WILL ROTATE THROUGH THE NW ATLC THROUGH EARLY 
THU. 

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

$$
PAW