000
AXPZ20 KNHC 291557
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAY 29 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 
1515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 94W FROM 02N-12N MOVING W AT 15 KT.  WAVE 
APPROACHES AREA OF GOOD UPPER LEVEL DIFFLUENT FLOW WHICH IS 
LIKELY TO ENHANCE CONVECTION GIVEN DEEP LAYER MOISTURE 
ASSOCIATED WITH WAVE.  GFS GUIDANCE APPEARS NOT TO HAVE GOOD 
INITIALIZATION...BUT DOES GENERATE LOW PRES IN VICINITY OF WAVE 
WITHIN 48 HR.

...ITCZ...
ITCZ AXIS ALONG 06N77W TO 09N93W TO 06N106 TO 12N121W TO 
04N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 
270 NM OF AXIS FROM 88W-105W.  SCATTERED MODERATE CONVECTION 
WITHIN 75 NM OF AXIS FROM 128W-131W.  

...DISCUSSION...
MID-UPPER LEVEL ELONGATED E-W RIDGE MADE UP OF SEVERAL SMALL 
ANTICYCLONIC EDDIES ENHANCES OUTFLOW OF CONVECTION DEBRIS AND 
PROVIDES DEEP MOISTURE LAYER FOR FURTHER CONVECTION.  TROPICAL 
WAVE MENTIONED ABOVE AND SURFACE TROUGH ALONG 127W ABLE TO BUILD 
SCATTERED MODERATE TO STRONG CONVECTION WITH IT.  

UPPER LEVEL CYCLONE AT 32N119W MAINTAINS CONSTANT WESTERLY FLOW 
ALOFT N OF 10N W OF 115W.  NEW DEEP LAYER TROUGH APPROACHING 
140W WITH ASSOCIATED COLD FRONT 32N138W TO 29N140W BRINGING 
STRONG SW WINDS INTO NW CORNER OF E PAC.  COLD FRONT SWINGS NE 
WITHIN 24 HRS AND TAKE WINDS WITH IT...BUT LEAVE LARGE LONG 
PERIOD SWELLS AFFECTING N OF 27N W OF 129W BY SUN.

HIGH PRES 1018 MB AT 24N134W DRIFTING NW TIGHTENS PRES GRADIENT 
WITH WEAK SURFACE LOW PRES TROUGH ALONG CENTRAL MEXICO RESULTING 
IN FRESH NW WINDS N OF 23N WITHIN 90 NM OF BAJA CALIFORNIA 
COAST.  HIGH PRES WEAKENS WITHIN 48 HRS DIMINISHING WINDS THEN. 

$$
WALLY BARNES