000
AXPZ20 KNHC 310954
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAR 31 2013

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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
ITCZ AXIS 05N77W TO 03N84W TO 05N108W TO 01N125W.  SCATTERED
MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM N AND 90 NM 
S OF AXIS FROM 105W TO 120W. 

...DISCUSSION...
DEEP LAYERED CYCLONE H JUST N OF AREA AT 37N130W MOVES NE 
DRAGGING UPPER LEVEL TROUGH ACROSS NW PORTION OF BASIN FROM 
32N126W TO 20N134W.  VERY DRY AND STABLE AIR MASS N AND W OF 
TROUGH AXIS.  DOWNSTREAM FROM AXIS...ABUNDANT TROPICAL MOISTURE
ADVECTS NE TOWARDS SOUTHERN BAJA CALIFORNIA AND CENTRAL MEXICO. 
SWATH OF MOISTURE RIDES 90 KT JET CORE OVER RIDGE CREST.  ITCZ
TAKES ADVANTAGE OF WEAK DIVERGENT FLOW ALOFT TO PRODUCE SCATTERED
MODERATE ISOLATED STRONG CONVECTION ALONG ITS AXIS FROM 105W TO 
130W.  

WEAK UPPER LEVEL TROUGH DOWNSTREAM FROM RIDGE CREST EXTEND FROM
GULF OF TEHUANTEPEC TO 00N120W.  MODERATE TO STRONG SUBSIDENCE 
ALOFT MAINTAINS VERY DRY CONDITIONS S OF 18N E OF 105W.

...ELSEWHERE AT THE LOWER LEVELS...
GULF OF PAPAGAYO...E-NE WINDS CONTINUE TO PULSE REACHING A FRESH
BREEZE IN LATE NIGHT AND EARLY MORNING DUE TO COOL DOWNSLOPING
AIR THEN DIMINISH IN THE LATE MORNING AND AFTERNOONS AS THE SEA
BREEZE COUNTERS EASTERLY FLOW.  OVERALL WIND FIELD EXPECTED TO 
DIMINISH LATE TUE AS CARIBBEAN PRES GRADIENT RELAXES.

LARGE SWELLS GENERATED BY PREVIOUS STRONG WINDS DOWNSTREAM OF
GULFS OF TEHUANTEPEC AND PAPAGAYO MERGE WELL W OF ITS SOURCE AND
COVER LARGE PORTION OF BASIN FROM 05N TO 18N W OF 120W.  SWELLS
PROPAGATE W AND HOLD THEIR HEIGHTS AS TRADE WINDS STRENGTHEN.

SURFACE HIGH PRES AT 28N122W WITH GOOD SUPPORT OF RIDGE ALOFT
PREVENTS VERTICAL MOTION OF ADVECTED MOISTURE WITH LITTLE 
PRECIPITATION TO SHOW.  BUT AS HIGH PRES INTENSIFIES SO DOES 
PRES GRADIENT WITH ITCZ STRENGTHENING TRADES TO A FRESH BREEZE 
EARLY MON AND STRONGER ON TUE.  

...LOOKING AHEAD...
SECOND DEEP LAYER CYCLONE WITH SURFACE LOW PRES AND ATTENDANT
COLD FRONT APPROACH WESTERN FRINGES OF E PAC MON BUT SUFFERS THE
SAME CRUSHING FATE AS THE PRESENT ONE AT THE HANDS OF BUILDING
1022 MB HIGH PRES.

$$
WALLY BARNES