000
AXPZ20 KNHC 210344
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION TWO-E REMAINS EMBEDDED IN THE MONSOON TROUGH.
SATELLITE IMAGERY SHOWS ORGANIZED LOW LEVEL CLOUD LINES COILING
INTO THE CENTER OF THE CIRCULATION. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN 120 NM OF THE CENTER. SEE LATEST TROPICAL 
CYCLONE ADVISORY WTPZ22/TCMEP2 KNHC FOR FURTHER DETAILS ON 
TROPICAL DEPRESSION TWO-E.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 09N83W TO 11N93W TO TROPICAL 
DEPRESSION TWO-E NEAR 09N99W TO 07N125W. THE ITCZ AXIS EXTENDS 
FROM 07N125W TO BEYOND 04N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS WITHIN 150 NM EITHER SIDE OF TROUGH AXIS E 
OF 98W.

...DISCUSSION...
AN ACTIVE MONSOON TROUGH PERSISTS E OF 103W. A BROAD UPPER LEVEL 
ANTICYCLONE CENTERED OVER GUATEMALA EXTENDS A UPPER RIDGE OVER 
THE SURFACE TROUGH FROM 65W TO 112W. 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 ARE FUNNELING THROUGH AND DOWNSTREAM 
OF ISTHMUS OF TEHUANTEPEC FROM THE PRES GRADIENT BETWEEN RIDGING 
IN THE WESTERN GULF OF MEXICO AND A TROUGH OVER THE E COAST OF 
THE YUCATAN PENINSULA. HIGH PRES OVER THE NORTHERN GULF OF 
MEXICO WILL RETROGRADE WEST THEN WEAKEN AS IT SINKS SOUTHWARD 
MON. THE PRES GRADIENT WILL REMAIN STRONG BETWEEN THIS RIDGE AND 
TROPICAL DEPRESSION TWO-E. THIS WILL ALLOW E-NE WINDS TO REMAIN 
FRESH TO STRONG DOWNSTREAM FROM THE GULF OF TEHUANTEPEC TO 
AROUND 102W THROUGH EARLY TUE.

A RELATIVELY WEAK 1022 MB SUBTROPICAL HIGH NEAR 30N136W EXTENDS 
A WEAK RIDGE ACROSS THE NORTHERN PORTION OF THE FORECAST AREA. A 
COLD FRONT APPROACHING FROM THE NW WILL FORCE THE HIGH SW TO 
NEAR 30N140W WHERE IT WILL GRADUALLY STRENGTHEN THROUGH EARLY 
TUE. THE ASSOCIATED PRES GRADIENT ON THE E SIDE OF THE HIGH WILL 
SUPPORT MODERATE TO FRESH N-NW WINDS W OF THE BAJA PENINSULA 
OVER NE WATERS THIS MORNING...BECOMING FRESH TO STRONG TUE 
THROUGH FRI. THE PRES GRADIENT WILL TIGHTEN TUE AND EXPAND THE 
AREA OF FRESH WINDS SOUTHWESTWARD AND BUILD SEAS TO AROUND 8 FT 
BY TUE NIGHT IN WESTERN PORTION OF THE DISCUSSION AREA. 

REMNANT LOW OF TROPICAL DEPRESSION ALETTA IS NEAR 12N112W SINKING
SLOWLY S AND TRANSITIONING INTO AN ELONGATED TROUGH WITH ONLY A 
ELONGATED SWIRL OF LOW LEVEL CLOUDS.

$$
MUNDELL