000
AXPZ20 KNHC 140934
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT AUG 14 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 
0630 UTC.

...TROPICAL WAVE...

A TROPICAL WAVE N OF 07N ALONG 84W IS MOVING WEST AT 15 KT. THIS 
WAVE IS EXPECTED TO INTERACT WITH AN AREA OF BROAD TROUGHING OFF 
THE COAST OF MEXICO THAT WILL STEER IT N OF WEST OVER THE NEXT 
FEW DAYS. THE WAVE IS FORECAST TO REACH THE GULF OF TEHUANTEPEC 
SUN NIGHT AS IT ENCOUNTERS INCREASING NORTHEASTERLY FLOW ALOFT 
THAT WILL INHIBIT THE DEVELOPMENT OF DEEP CONVECTION.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED FROM 11N86W TO 
12N95W TO 11N110W TO 10N125W TO 10N140W. SCATTERED MODERATE TO 
STRONG CONVECTION LIES WITHIN 150 NM N OF THE ITCZ AXIS BETWEEN 
88W AND 94W WHILE SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION IS WITHIN 120 NM N OF THE ITCZ AXIS BETWEEN 101W AND 
107W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE LIES NEAR 31N113W AND EXTENDS A RIDGE 
SOUTHWESTWARD TO NEAR 23N132W. UPPER LEVEL DIFFLUENCE ON THE SE 
SIDE OF THIS ANTICYCLONE IS ENHANCING SCATTERED MODERATE TO 
STRONG CONVECTION OVER THE CENTRAL GULF OF CALIFORNIA AND 
NORTHEAST MEXICO. AN UPPER TROUGH LIES WEST OF THE RIDGE AXIS 
FROM 22N137W TO 30N133W AND THEN N OF AREA. DRY AIR IN 
SUBSIDENCE CAN BE FOUND IN MUCH OF THE REGION NW OF A LINE FROM 
30N124W TO 15N140W. ON THE SE SIDE OF THE RIDGE LIES ANOTHER 
UPPER TROUGH. THIS TROUGH EXTENDS FROM THE TEXAS/MEXICO BORDER 
NEAR 29N103W SOUTHWESTWARD TO 21N116W. ANOTHER ANTICYCLONE ALOFT 
LIES SE OF THIS TROUGH NEAR 23N102W. UPPER DIFFLUENCE ON THE 
WESTERN SIDE OF THIS ANTICYCLONE IS ENHANCING SCATTERED MODERATE 
WITH ISOLATED STRONG CONVECTION WITHIN 90 NM OF THE MEXICAN 
COAST FROM 18N TO 23N. AN UPPER LOW OVER THE YUCATAN PENINSULA 
EXTENDS A TROUGH SOUTH TO THE GUATEMALA/EL SALVADOR BORDER. 
UPPER LEVEL DIFFLUENCE BETWEEN THIS TROUGHING AND THE 
ANTICYCLONE TO ITS NORTHEAST IS ENHANCING CONVECTION FROM THE 
ITCZ TO THE COAST BETWEEN 88W AND 94W.

A SURFACE RIDGE LIES FROM 28N140W TO 26N117W. THE PRESSURE 
GRADIENT BETWEEN THIS RIDGE AND TROUGHING IN THE GULF OF 
CALIFORNIA WILL RESULT IN N TO NW WINDS TO 20 KT NEAR THE W 
COAST OF BAJA CALIFORNIA N OF 26N OVER THE NEXT FEW DAYS. 
TROUGHING OVER THE SW U.S. WILL DEEPEN SUNDAY AS A COLD FRONT 
DIVES SOUTH OF THE FOUR CORNERS. THIS WILL INCREASE THE PRES 
GRADIENT OVER THE NORTHERN GULF OF CALIFORNIA AND INCREASE 
SOUTHERLY WINDS TO 20 KT BY SUNDAY EVENING. SOUTHERLY FLOW 
THROUGH THE GULF OF CALIFORNIA AND ON THE BACKSIDE OF THE LOW 
PRES SYSTEM CURRENTLY NEAR 16N110W IS EXPECTED TO TRANSPORT 
MOISTURE NORTHWARD THROUGH THE GULF INTO THE SW U.S. AND NE 
MEXICO. AN INCREASED CHANCE OF SHOWERS AND TSTMS IS EXPECTED IN 
THAT AREA AS A RESULT.

THE AFOREMENTIONED 1006 MB LOW PRES SYSTEM NEAR 16N110W IS PART 
OF A BROAD AREA OF LOW PRES THAT IS DRAWING ITCZ MOISTURE 
NORTHEASTWARD FROM CENTRAL WATERS. THE 0510 ASCAT PASS SHOWS 
20-25 KT SOUTHWEST WINDS FEEDING INTO THE SOUTH SIDE OF THIS 
BROAD TROUGH AND HELPING KEEP SEAS IN THE 8 TO 10 FT RANGE IN SW 
SWELL. SOME MID LEVEL SHORTWAVE ENERGY CURRENTLY IN THE VICINITY 
OF MANZANILLO MEXICO IS EXPECTED TO MERGE INTO THE NORTHERN SIDE 
OF THE LOW PRES SYSTEM TO ITS WEST. THE LOW IS FORECAST TO SHIFT 
GRADUALLY NORTHEASTWARD OVER THE WEEKEND AS THIS ENERGY IS 
INCORPORATED.

$$
SCHAUER