000
AXPZ20 KNHC 131531
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI AUG 13 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1445 UTC.

...SPECIAL FEATURE...

THE 1006 MB LOW PRESSURE CENTER NOW IS JUST INLAND NEAR
17.6N101W...JUST TO THE NORTHWEST OF ACAPULCO MEXICO.
THE LOW CENTER IS MOVING NORTHWESTWARD ABOUT 10 KT.
WIDELY SCATTERED TO SCATTERED MODERATE SHOWERS AND ISOLATED
STRONG THUNDERSTORMS ARE FROM 16N TO 19N BETWEEN 98W AND 104W.
SIMILAR PRECIPITATION ALSO IS FROM 12N TO 16N BETWEEN 98W AND
106W. 

...THE ITCZ...

FROM COSTA RICA NEAR 10N84W TO 08N89W TO 12N96W...13N103W
09N121W 11N133W BEYOND 10N140W. STRONG SHOWERS AND THUNDERSTORMS 
ARE FROM 07N TO 09N BETWEEN 95W AND 97W...AND WITHIN A 30 NM 
RADIUS OF 11N89W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG 
THUNDERSTORMS ARE FROM 11N TO 12N BETWEEN 107W AND 109W.

...DISCUSSION...

A 1007 MB LOW PRESSURE CENTER IS NEAR 16N110W...FORECAST
TO BE STATIONARY IN MOVEMENT DURING THE NEXT 24 HOURS.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 14N
TO 16N BETWEEN 111W AND 114W.

AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 35N129W.
A TROUGH EXTENDS FROM THIS CYCLONIC CENTER...THROUGH 30N130W
TO A SECOND CYCLONIC CENTER THAT IS NEAR 20N133W. THE TROUGH
CONTINUES TOWARD 15N138W. DRY AIR IN SUBSIDENCE IS NEAR THIS 
TROUGH. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS APPARENT 
WITH THIS TROUGH.

AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS OVER MEXICO NEAR
27N104W. CYCLONIC FLOW COVERS PARTS OF THE EASTERN PACIFIC 
OCEAN...MEXICO...AND TEXAS FROM 20N TO 31N BETWEEN 98W AND 114W.

A SURFACE RIDGE RUNS FROM 22N132W BEYOND 26N140W. THE PRESSURE 
GRADIENT THAT IS BETWEEN THE RIDGE AND THE BROAD SURFACE LOW 
PRESSURE THAT COVERS THE EASTERN PACIFIC OCEAN TO THE NORTH
OF 09N BETWEEN 94W AND 120W WILL RESULT IN NORTHERLY TO 
NORTHWESTERLY WINDS TO 20 KT NEAR THE WESTERN COAST OF BAJA
CALIFORNIA TO THE NORTH OF 26N DURING THE NEXT 24 TO 30 HOURS.
THE BROAD AREA OF LOW PRESSURE IS DRAWING ITCZ MOISTURE 
NORTHEASTWARD FROM CENTRAL WATERS. SOUTHWESTERLY WINDS REACHING
20 KT WILL FEED INTO THE SOUTH SIDE OF THIS BROAD TROUGH...
AND HELP TO KEEP SEAS IN THE 8 TO 10 FT RANGE IN SOUTHWESTERLY 
SWELL.
 
SOME SHORTWAVE ENERGY HAS BROKEN OFF FROM THE CARIBBEAN SEA
TROPICAL WAVE THAT REACHES 10N80W. THIS SYSTEM IS EXPECTED
TO FORCE A SURFACE TROUGH IN THE EASTERN PACIFIC OCEAN TO THE
NORTH OF 04N...THAT WILL MOVE WESTWARD FROM COASTAL COSTA RICA
THROUGH THE GULF OF FONSECA. A FEW OF THE DYNAMICAL MODELS FAVOR
SOME DEVELOPMENT OF THIS SYSTEM DURING THE NEXT DAY OR TWO.
INCREASING NORTHWESTERLY WIND FLOW ACROSS THE NORTHERN PART
OF THE TROUGH LATER IN THE WEEKEND IS EXPECTED TO INHIBIT
ANY FURTHER DEVELOPMENT.

$$
MT