000
AXPZ20 KNHC 110311
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED MAY 11 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS ALONG 07N86W TO O8N114W TO 06N129W TO 04N140W.  SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 180 NM S OF AXIS E OF 95W. 
SCATTERED MODERATE CONVECTION WITHIN 180 NM S OF AXIS FROM 98W 
TO 102W AND WITHIN 210 NM N OF AXIS FROM 102W TO 107W. 

...DISCUSSION...
DEEP LAYER TROUGH EXTEND FROM 32N113W TO WELL DEFINED CYCLONIC 
VORTEX AT 23N137W.  VERY DRY AIR MASS WITHIN 240 NM BOTH SIDES 
OF TROUGH AXIS.  JET CORE 90 KT ADVECTS ABUNDANT MOISTURE FROM 
DEEP TROPICS NE TOWARDS SRN BAJA CALIFORNIA AND CENTRAL MEXICO 
THEN N-NE INTO CENTRAL TEXAS WHERE DRY LINE PROMPT SCATTERED 
CONVECTION ACROSS CENTRAL PLAINS.  WELL ANCHORED ANTICYCLONIC 
GYRE AT 08N102W COVERS MOST OF REMAINDER OF BASIN.  MODERATE 
DIFFLUENCE UNDER GYRE ENHANCING DEEP CONVECTION ALONG ITCZ AND 
STATIONARY EMBEDDED LOW PRES 1007 MB AT 08N102W.  THERE IS NO 
SIGNIFICANT TROPICAL ORGANIZATION NOTED IN FEATURE IN SPITE OF 
MINIMAL SHEAR AND UPPER LEVEL ENVIRONMENT REMAINS FAVORABLE.
MODEL GUIDANCE RELUCTANT TO INTENSIFY FEATURE WITH GFS THE MOST 
AGGRESSIVE BY DEEPENING IT NEXT 48 HRS THEN WEAKEN IT TO 
OBLIVION AFTER THAT. 

...AT THE SURFACE...
HIGH PRES CENTER 1024 MB AT 35N137W AND LOW PRES TROUGH OVER 
CALIFORNIA TIGHTEN GRADIENT TO PROMPT FRESH TO STRONG NW WINDS 
ALONG BAJA CALIFORNIA W COAST THROUGH NEXT 12 HRS.  HIGH PRES 
QUICKLY WEAKENS AND DISSIPATES EFFECTIVELY EASING GRADIENT AND 
DIMINISHING WINDS.  

ITCZ REMAINS ACTIVE E OF 117W AS MOISTURE IS FED FROM LOW PRES 
1007 MB JUST W OF COSTA RICA.  AFOREMENTIONED EMBEDDED LOW PRES 
PROVIDES MECHANICAL UPLIFT AND UPPER ENVIRONMENT ENHANCES 
SCATTERED DEEP CONVECTION.

$$
WALLY BARNES