000
AXPZ20 KNHC 182135
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED AUG 18 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED 09N84W TO 
13N97W TO 11N110W TO 09N125W TO 07N140. SCATTERED MODERATE/ 
ISOLATED STRONG CONVECTION IS FROM 08N TO 11N BETWEEN 96W AND 
100W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM BOTH SIDES 
OF THE ITCZ BETWEEN 111W AND 119W. 

...DISCUSSION...

AN UPPER LOW IS INLAND OVER S MEXICO JUST W OF GUATEMALA NEAR 
16N93W EXTENDING AN UPPER TROUGH S TO 13N93W AND SUPPORTING A 
SURFACE TROUGH THAT EXTENDS FROM THE FROM OVER S MEXICO NEAR 
19N95W THROUGH THE ISTHMUS AND GULF OF TEHUANTEPEC TO 13N94W 
GENERATING CLUSTERS OF SCATTERED MODERATE CONVECTION N OF 10N TO 
THE COAST OF MEXICO AND GUATEMALA BETWEEN 90W AND 97W. AN UPPER 
RIDGE ANCHORED OVER TEXAS EXTENDS A RIDGE AXIS W ACROSS N MEXICO 
TO NEAR 26N120W DRAWING UPPER LEVEL TROPICAL MOISTURE INTO THE 
REGION S OF 20N E OF 110W. A SECOND UPPER LEVEL RIDGE IS 
CENTERED NEAR 28N134W WITH RIDGE AXIS EXTENDING SW TO BEYOND 
21N140W AND NE TO BEYOND 32N131W. THE REGION N OF 20N W OF 125W 
IS MARKED BY RELATIVELY DRY STABLE CONDITIONS WITH ONLY LOW 
LEVEL STRATOCUMULUS CLOUD DECK. A WEAK UPPER LEVEL INVERTED 
TROUGH LIES IN THE TROPICS FROM 10N136W TO 20N131W. 
OTHERWISE...EASTERLY FLOW PREVAILS IN THE DEEP TROPICS S OF 20N. 

OTHER SURFACE FEATURES...A SECOND SURFACE TROUGH IS OFF THE W 
COAST OF MEXICO EXTENDING FROM 19N107W TO 14N101W GENERATING 
CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 150 NM OF LINE 
FROM 13N99W TO 20N109W. A THIRD WEAKER SURFACE TROUGH IS IN THE 
TROPICS EXTENDING FROM 16N133W TO 11N127W. WEAK SURFACE RIDGE 
EXTENDS FROM A WEAKENING 1026 MB HIGH NW OF THE DISCUSSION AREA. 

CROSS EQUATORIAL SWELL UP 8 TO 9 FT COVERS THE CENTRAL WATERS N 
OF 10N REACHING THE COAST OF MEXICO AND WESTERN PANAMA BY THU 
EVENING AND 10 FT REACHING THE SAME AREA BY FRI NIGHT FINALLY 
SUBSIDING SLIGHTLY LATE SUN THROUGH MON. 

$$
PAW