000
AXPZ20 KNHC 181012
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU NOV 18 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS IS ALONG 10N86W 6N95W 11N115W 10N125W 9N140W. NO 
SIGNIFICANT CONVECTION.

...DISCUSSION...
UPPER LEVEL RIDGE OVER THE NW PORTION OF THE DISCUSSION WITH 
AXIS FROM 32N130W TO AN ANTICYCLONIC CIRCULATION NEAR 12N124W.
FLOW BETWEEN THE RIDGE AND A CYCLONIC CIRCULATION W OF THE AREA
IS ADVECTING MID AND UPPER LEVEL MOISTURE THROUGH THE CREST OF 
THE RIDGE.   AN UPPER LEVEL TROUGH IS E OF THE RIDGE EXTENDS 
FROM A CYCLONIC CIRCULATION NEAR THE CALIFORNIA/ARIZONA BORDER 
ACROSS THE BAJA PENENSULA TO 17N116W. MODERATE TO STRONG 
SUBSIDENCE WITH VERY DRY STABLE AIR ALOFT ACROSS THE AREA N OF 
20N E OF 125W EXCEPT FOR AN AREA OF MID TO HIGH CLOUDS FROM 
21N-25N BETWEEN 121W AND 116W. SW TO W FLOW ALOFT SE OF TROUGH IS 
ADVECTING MID/UPPER LEVEL MOISTURE FROM THE ITCZ TO CENTRAL 
MEXICO. AN UPPER LEVEL RIDGE EXTENDS FROM THE SW CARIBBEAN 
ACROSS CENTRAL AMERICA TO 10N92W.

SURFACE TROUGH EXTENDS FROM 17N111W TO 1012 MB LOW PRES ALONG 
THE ITCZ NEAR 11N120W. A FEW SHOWERS ARE NEAR THE LOW PRES 
CENTER. ANOTHER TROUGH EXTENDS FROM 13N128W TO 8N130W. A FEW 
SHOWERS ARE ALONG THE TROUGH. ANOTHER 1012 MB SURFACE LOW IS 
ANALYZED ALONG THE ITCZ AT 10N135W. NO SIGNIFICANT WEATHER 
ASSOCIATED WITH THE LOW. OTHERWISE HIGH PRES RIDGE COVERS THE 
AREA N OF 17N W OF 115W. THE RIDGE HAS WEAKENED AND THE WINDS 
HAVE DECREASED OVER THE NW PORTION OF THE AREA HOWEVER SWELLS TO 
9 FT CONTINUE BUT ARE FORECAST TO SUBSIDE TO BELOW 8 FT IN THE 
NEXT 24 HOURS.

COLD FRONT MOVING THROUGH THE GULF OF MEXICO WILL BE RE-ENFORCED
AND STRONG HIGH PRES WILL BUILD ACROSS THE GULF WITH A STRONG 
PRES GRADIENT OVER SOUTHERN MEXICO RESULTING IN GALE FORCE WINDS 
DEVELOPING THROUGH THE GULF OF TEHUANTEPEC LATER TODAY AND 
INCREASING FURTHER TO STORM FORCE TONIGHT AND BACK TO GALE FRI 
EVENING.
 
$$
DGS