000
AXPZ20 KNHC 211000
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON MAY 21 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION TWO-E REMAINS EMBEDDED IN MONSOON TROUGH...
BUT MAINTAINS GOOD OUTFLOW ALOFT.  WARM SST...PLENTY OF 
AVAILABLE MOISTURE AND LOW SHEAR KEEPS SYSTEM READY FOR SLOW 
INTENSIFICATION.  CLUSTERS OF MODERATE TO STRONG DEEP CONVECTION 
NOTED IN BANDS AROUND SOUTHERN SEMICIRCLE AND NW QUADRANT OF 
CENTER.  SEE LATEST TROPICAL CYCLONE ADVISORY WTPZ22/TCMEP2 KNHC 
FOR FURTHER DETAILS ON TROPICAL DEPRESSION TWO-E.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 10N86W TO 12N94W TO TROPICAL 
DEPRESSION TWO-E AT 09.3N99.9W TO 06N121W THEN ITCZ TO 06N129W 
TO BEYOND 03N140W.  ISOLATED MODERATE CONVECTION WITHIN 90 NM OF 
TROUGH AXIS E OF 98W.

...DISCUSSION...
UPPER LEVEL TROUGH CUTS THROUGH NW CORNER OF BASIN FROM 32N128W 
TO DEEP LAYER CYCLONE AT 19N141W THEN TURN SE TO 00N119W.  VERY 
DRY SUBSIDING AIR MASS COVER EXTENSIVE PART OF E PAC N OF 16N 
AND ALSO W OF 116W.  WELL DEFINED ANTICYCLONE AT 18N107W IS 
UNABLE TO ADVECT ANY SIGNIFICANT TROPICAL MOISTURE FROM ITCZ/ 
MONSOON TROUGH NORTHWARD.  ELSEWHERE...WEAK RIDGE ALONG 09N/10N 
PROVIDES FAVORABLE DIVERGENT FLOW ALOFT FOR LOW PRES AT 09.3N 
99.3W TO ENHANCE SCATTERED DEEP CONVECTION WITHIN 300 NM SE AND 
360 NM SW OF CENTER OF DEPRESSION TWO-E.  MODEL GUIDANCE 
STRENGTHEN SYSTEM AND STEER IT NW THEN TURNING N WITHIN 48 HOURS 
POSING A THREAT TO MAINLAND MEXICO.  INTERESTS SHOULD MONITOR 
DETAILS OF TROPICAL DEPRESSION TWO-E AT THE ABOVE MENTIONED NHC 
PRODUCTS. 

..AT THE LOWER LEVELS...
 DIVERGENT FLOW ALOFT AND LIGHT ANTICYCLONIC WIND SHEAR S OF THE 
RIDGE IS MAINTAINING A VERY FAVORABLE ENVIRONMENT FOR DEEP 
CONVECTION. ABUNDANT TROPICAL MOISTURE IS POOLED S OF THE 
MONSOON TROUGH E OF 105W. SCATTERED MODERATE TO STRONG 
CONVECTION CONTINUES TO PULSE IN CLUSTERS ACROSS THIS VERY 
UNSTABLE REGION...FURTHER ENHANCING DIVERGENCE ALOFT...AND 
AIDING IN THE MAINTENANCE OF THE UPPER LEVEL RIDGE.

FRESH TO STRONG N-NE WINDS CONTINUE OVER GULF OF TEHUANTEPEC DUE 
TO PRES GRADIENT BETWEEN RIDGE IN WESTERN GULF OF MEXICO AND 
TROUGH OVER E COAST OF YUCATAN PENINSULA.  WINDS EXPECTED TO 
EXTEND TO THE N OF TROPICAL DEPRESSION TWO-E ENHANCING LOW LEVEL 
WIND CONVERGENCE.

HIGH PRES JUST NW OF BASIN EXTEND WEAK RIDGE TO 15N115W KEEPING 
STRATIFIED LOW LEVEL CLOUDS DEVOID OF VERTICAL DEVELOPMENT.  
ASSOCIATED PRES GRADIENT SUPPORT MODERATE TO FRESH NE TRADES 
WITHIN NEXT 24-36 HRS WINDS.  

REMNANT LOW OF TROPICAL DEPRESSION ALETTA NOW A WEAK TROUGH 
BARELY IDENTIFIED IN 0600 UTC ANALYSIS.

$$
WALLY BARNES