000
AXNT20 KNHC 270554
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
205 AM EDT WED OCT 27 2010

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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND 
RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0445 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 12N34W 7N38W TO 2N40W MOVING W NEAR 
15 KT. WAVE REMAINS EMBEDDED WITHIN A BROAD MID LEVEL CYCLONIC 
CURVATURE. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE 
WITHIN 300 NM OF THE TROUGH AXIS. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N12W 3N20W 5N30W WITH NO 
SIGNIFICANT CONVECTION. 
 
...DISCUSSION...

GULF OF MEXICO...
A LARGE UPPER TROUGH COVERS MOST OF THE CONUS FROM THE CENTRAL 
PLAIN STATES TO OVER NEW ENGLAND AND TO OVER THE GULF N OF A 
LINE FROM TAMPA FLORIDA TO TUXPAN MEXICO WITH THE ASSOCIATED 
STATIONARY FRONT ACROSS CENTRAL LOUISIANA AND E TEXAS. THE 
REMNANTS OF WHAT WAS RICHARD IS AT 26/0300 UTC A SURFACE TROUGH 
ALONG 94W FROM 22N-25N. BROAD UPPER RIDGE ANCHORED IN THE W 
CARIBBEAN REMAINS ACROSS THE SE GULF AND CONTINUES TO ADVECT 
TROPICAL MOISTURE OVER THE AREA GENERATING ISOLATED SHOWERS S OF 
25N E OF 91W TO OVER THE FLORIDA STRAITS AND THE FLORIDA KEYS. 
WATER VAPOR IMAGERY CONTINUES TO INDICATE STRONG SUBSIDENCE AND 
DRY AIR IMPACTING ALL BUT THE FAR SE GULF GIVING THE REMAINDER 
OF THE GULF CLEAR SKIES AGAIN TONIGHT. 

CARIBBEAN SEA...
BROAD UPPER RIDGE REMAINS OVER THE W CARIBBEAN ANCHORED BETWEEN 
THE CAYMAN ISLANDS AND HONDURAS NEAR 17N83W COVERING ALL BUT THE 
FAR E CARIBBEAN W OF 66W PROVIDING DIFFLUENCE ALOFT AND COUPLED 
WITH ANY REMNANT TROPICAL MOISTURE OVER THE SW CARIBBEAN TO 
GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S 
OF A LINE FROM COLOMBIA NEAR 11N73W TO NE NICARAGUA NEAR 15N83W. 
WATER VAPOR IMAGERY INDICATES MODERATE/STRONG SUBSIDENCE AND DRY 
AIR CONTINUES TO IMPACT MOST OF THE CARIBBEAN MAINLY E OF 80W 
GIVING THE REMAINDER OF THE AREA FAIR WEATHER AGAIN TONIGHT WITH 
SOME POSSIBLE ISOLATED LOW LEVEL SHOWERS MOVING ACROSS THE E 
CARIBBEAN E OF 70W.

ATLANTIC OCEAN...
THE BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN EXTENDS OVER THE 
SW ATLC S OF 27N W OF 66W PROVIDING DIFFLUENCE ALOFT AND COUPLED 
WITH LINGERING MOISTURE CONTINUE TO GENERATE ISOLATED SHOWERS 
FROM 23N-27N BETWEEN 72W-77W INCLUDING THE BAHAMAS. SHORTWAVE 
UPPER TROUGH IN THE CENTRAL ATLC EXTENDS FROM 29N56W TO E OF THE 
LEEWARD ISLANDS NEAR 17N58W SUPPORTING A SURFACE TROUGH 
EXTENDING FROM 25N53W TO 19N56W. AN UPPER RIDGE IS TO THE E OF 
THE SHORTWAVE UPPER TROUGH PROVIDING DIFFLUENCE ALOFT TO ENHANCE 
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 
90/120 NM OF LINE FROM 21N49W TO 27N56W WITH ISOLATED SHOWERS 
WITHIN 120 NM OF LINE FROM 19N51W 23N58W. A SURFACE RIDGE COVERS 
THE W INTO THE CENTRAL ATLC W OF 50W ANCHORED BY A 1028 MB HIGH 
600 NM ENE OF BERMUDA LEAVING THE W ATLC UNDER FAIR WEATHER 
AGAIN TONIGHT. AN THE UPPER LOW IS IN THE E/CENTRAL ATLC 
CENTERED NEAR 24N40W SUPPORTING A SURFACE TROUGH THAT EXTENDS 
FROM 31N37W 28N40W THROUGH A 1008 MB SURFACE LOW CENTERED NEAR 
26N41W TO 23N42W. SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS ARE FROM 21N-33N BETWEEN 34W-41W. A WEAKENING  
SURFACE RIDGE CONTINUES TO DOMINATE THE FAR E ATLC N OF 25N E OF 
30W ANCHORED BY A 1028 MB HIGH E OF THE AZORES.

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

$$
PAW