000
AXPZ20 KNHC 022137
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN AUG 02 2009

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 2115 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS N OF 05N ALONG 93W AND IS MOVING W AT 15 TO 
20 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ENHANCED 
WITHIN 60 NM OF THE WAVE AXIS FROM 06N TO 11N. A LARGER CLUSTER 
OF SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 120 NM OF 13N98W...BUT IS CURRENTLY WEAKENING PER 
LIGHTNING DATA.

A TROUGH EXTENDS FROM 07N107W TO 16N105W AND IS MOVING WESTWARD 
SIMILAR TO THE TROPICAL WAVES TO ITS E AND W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 60 NM OF THE TROUGH 
AXIS.

A TROPICAL WAVE EXTENDS FROM 05N TO 17N ALONG 117W AND IS MOVING 
W AT 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED FROM 07N TO 15N BETWEEN 110W AND 121W. BROAD CYCLONIC 
IS CURRENTLY IS CENTERED AROUND 10N117W.

A TROPICAL WAVE EXTENDS FROM 06N TO 18N ALONG 134W AND IS MOVING 
W AT 10 TO 15 KT. ALTHOUGH CYCLONIC TURNING IS NOTED AT 
07N135W...ONLY ISOLATED WEAK CONVECTION IS NOTED ALONG THE WAVE 
ALONG 10N.

...ITCZ...
THE AXIS IS ALONG 10N77W TO 11N104W TO 10N109W TO 12N116W TO 
09N122W TO 12N132W TO 11N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS OBSERVED WITHIN 60 NM OF LINE 05N78W TO 
07N88W. ISOLATED MODERATE AND STRONG CONVECTION IS NOTED 
ELSEWHERE AROUND THE PREVIOUSLY DESCRIBED TROPICAL WAVE 
CONVECTION FROM 06N TO 15N BETWEEN 90W AND 123W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS ALSO NOTED FROM 09N TO 
13N ALONG 139W.

...DISCUSSION...
A DEEP LAYERED CYCLONE IS CENTERED N OF THE AREA NEAR 36N129W 
WITH A TROUGH EXTENDING SE ALONG 32N122W TO 25N114W. FURTHER S 
OVER THE TROPICS IS ANOTHER UPPER CYCLONE NEAR 14N124W MOVING W 
WITH TIME. THE RESULT IS A BROAD UPPER TROUGH...ACCOMPANIED BY 
MOSTLY DRY UPPER AIR...OVER THE DISCUSSION AREA TO THE N OF 12N 
ROUGHLY ALONG 125W. THIS TROUGH SEPARATES TWO UPPER ANTICYCLONES 
WITH THE WESTERNMOST ANTICYCLONE CENTERED AT 16N137W. ITS 
ENVELOPE OF ANTICYCLONIC FLOW DOMINATES THE AREA FROM 15N TO 28N 
W OF 129W AND IS ADVECTING DEBRIS MOISTURE THAT ORIGINATED FROM 
TROPICAL STORM LANA...INTO THE AREA WITHIN 150 NM OF LINE 
27N140W TO 24N127W WHERE IT IMMEDIATELY EVAPORATES AS IT 
ENCOUNTERS THE BROAD TROUGH AND ASSOCIATED DRY AIR PREVIOUSLY 
MENTIONED. THE SECOND UPPER ANTICYCLONE IS CENTERED NEAR 27N101W 
WITH A RIDGE EXTENDING SW TO A CREST AT 20N115W. THE ASSOCIATED 
UPPER LEVEL DIFFLUENCE IS SUPPORTING THE CONVECTION OVER THE 
TROPICS BETWEEN 100W AND 122W.

AN UPPER TROUGH EXTENDS SW ACROSS THE NW CARIBBEAN AND THE 
YUCATAN PENINSULA INTO THE DISCUSSION AREA TO NEAR 07N98W. 
EMBEDDED SMALL UPPER CYCLONES ARE NOTED ALONG THE TROUGH AT 
17N92W AND 12N97W WITH CONVECTION ENHANCED OVER THE NE 
SEMICIRCLES OF BOTH FEATURES. THE UPPER LOW AT 12N97W IS MOVING 
W ROUGHLY IN PHASE WITH A TROPICAL WAVE RESULTING IN THE 
CONVECTIVE BURST CURRENTLY DISSIPATING NEAR 12N98W. THE UPPER 
LEVELS APPEAR VERY DRY S OF THE ITCZ...BASICALLY S OF 03N TO 
BEYOND 20S SUPPRESSING DEEP CONVECTION IN THE TROPICAL E PACIFIC.
        
AT THE LOW LEVELS...A SURFACE RIDGE HAS ITS AXIS FROM 28N141W TO 
15N108W. BROKEN TO LOCALLY OVERCAST STRATOCUMULUS CLOUDS ARE 
NOTED OVER THE AREA N OF 19N W OF 115W. 

GAP WINDS...NE TO E WINDS CONTINUE TO SURGE THROUGH AND JUST 
DOWNSTREAM OF THE GULF OF PAPAGAYO.

$$
NELSON