000
AXPZ20 KNHC 300949
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUL 30 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...
FROM 10N86W TO 09N97W TO 09N122W TO 11N134W TO 10N140W.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE
FROM 06N TO 08N BETWEEN PANAMA AND 80W...AND FROM 9N TO 10N 
BETWEEN 114W AND 124W. SCATTERED MODERATE TO STRONG SHOWERS AND 
THUNDERSTORMS ARE FROM 09N TO 11N BETWEEN 105W AND 112W. 

SCATTERED STRONG SHOWERS AND THUNDERSTORMS ARE FROM 14N TO 15N
BETWEEN 105W AND 106W...AND WITHIN A 30 NM RADIUS OF 18N107W.

...DISCUSSION...

A SURFACE LOW PRESSURE CENTER IS NEAR 09N94W. NUMEROUS STRONG 
SHOWERS AND THUNDERSTORMS ARE FROM 09N TO 12N BETWEEN 94W AND 
97W...AND FROM 14N TO 15N BETWEEN 94W AND 96W. SOME OF THE 
COMPUTER MODEL GUIDANCE SUGGESTS THAT SHORTWAVE ENERGY OVER
THE ISTHMUS OF TEHUANTEPEC OF MEXICO WILL MOVE SOUTHWARD
THROUGH THE GULF OF TEHUANTEPEC INTO THE WESTERN SIDE OF
THIS LOW CENTER. THE PASSAGE OF THE SHORTWAVE ENERGY HAS
BROUGHT NORTH TO NORTHEAST WINDS REACHING 20 KT INTO THE
GULF OF TEHUANTEPEC. THESE WINDS ARE EXPECTED TO INCREASE
TO 25 KT DOWNWIND OF THE GULF OF TEHUANTEPEC BY FRIDAY
MORNING. THE WINDS ARE EXPECTED TO DIMINISH TO LESS THAN
20 KT IN THIS AREA BY SATURDAY EVENING.

AN UPPER LEVEL TROUGH PASSES THROUGH 32N137W BEYOND 30N140W.
A 30 KT TO 50 KT UPPER LEVEL JET STREAM IS WITHIN 750 NM
TO THE EAST OF THE TROUGH FROM 27N TO 30N.

AN UPPER LEVEL TROUGH IS ALONG 28N116W TO A CYCLONIC CIRCULATION 
CENTER THAT IS NEAR 24N117W TO 17N118W. CYCLONIC FLOW COVERS THE 
AREA THAT IS TO THE NORTH OF 17N BETWEEN 110W AND 121W. THIS 
PATTERN IS EXPECTED TO BECOME MORE AMPLIFIED AND RETROGRADE 
SLIGHTLY WESTWARD DURING THE NEXT COUPLE OF DAYS. DRY AIR IN 
SUBSIDENCE COVERS THE AREA TO THE NORTHWEST OF THE LINE FROM 
24N112W TO 17N117W 17N125W 07N126W 05N120W 00N120W.

BROAD UPPER LEVEL CYCLONIC FLOW COVERS THE AREA FROM 10N TO 20N 
BETWEEN 130W AND 140W. ISOLATED MODERATE SHOWERS ARE WITHIN
A 30 NM RADIUS OF 11N133W AND 10N136W.

A SURFACE TROUGH IS ALONG 15N113W 13N116W 12N118W. STRONG 
SHOWERS AND THUNDERSTORMS ARE WITHIN A 30 NM RADIUS OF 12N118W. 
SOUTHERLY SWELLS THAT REACH 9 FEET ARE TO THE SOUTH OF 10N TO 
THE WEST OF 100W...AND INTO THE CENTRAL WATERS THAT ARE TO THE 
SOUTH OF 19N BETWEEN 103W AND 110W WHERE SE WINDS TO 20 KT ARE 
TO THE NORTH OF 16N.

BROAD SURFACE ANTICYCLONIC FLOW COVERS THE AREA
TO THE NORTH OF 16N TO AND WEST OF 116W.

$$
MT