000
AXPZ20 KNHC 182150
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC MON MAR 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
MONSOON TROUGH FROM 09N84W TO 05N93W THEN ITCZ TO 01N111W TO 
02N123W.  SCATTERED MODERATE WITHIN 60 NM OF AXIS FROM 113W TO
116W AND WITHIN 45 NM OF AXIS E OF 92W.

...DISCUSSION...
SHARP UPPER LEVEL LONGWAVE TROUGH CUTS DEEP SW FROM CENTRAL
MEXICO TO 10N115W THEN S-SE TO 00N110W.  VIGOROUS SHORT WAVE
APPROACHES NE MEXICO/SE TEXAS READY TO START NEXT WEATHER 
EPISODE IN GULF OF MEXICO.  MEANWHILE IN THE E PAC...WEAK RIDGE
DOWNSTREAM OF LONGWAVE TROUGH BRINGS MINOR AMOUNT OF TROPICAL
MOISTURE INTO E PAC E OF 92W ALONG MONSOON TROUGH PRODUCING
SCATTERED MODERATE CONVECTION.  ON THE UPSTREAM SIDE OF TROUGH
...BROAD RIDGE CREST ALONG 130W ADVECTS ABUNDANT MOISTURE E OF 
ITS AXIS.  SECOND LONG WAVE UPPER LEVEL TROUGH SUPPORTED BY 
DEEP LAYER CYCLONE AT 38N146W HAS ATTENDANT COLD FRONT 32N139W
TO 22N145W.  TROUGH PUSHES RIDGE CREST EASTWARD AS CYCLONE SHIFT
NE.  

...AT THE LOWER LEVELS...
SURFACE HIGH PRES CENTER 1025 MB AT 35N128W DRIFT E MAINTAINING 
DRY AND STABLE PATTERN OVER MOST OF BASIN WITH GENTLE TO 
MODERATE BREEZE ACROSS ENTIRE BASIN.  SUBSIDING 8 FT SWELL FROM
PREVIOUS GAP WIND EVENTS ACROSS GULFS OF PAPAGAYO...TEHUANTEPEC
AND FONSECA LINGER IN THE MIDDLE OF BASIN WITH A SLIGHT WESTWARD
DRIFT. 

PREVIOUS SWELLS N OF 28N CAUSED BY STRONG NW WINDS ALONG COAST
OF CALIFORNIA HAVE BACKED N AGAIN.  WINDS DIMINISHED AND HIGH 
PRES WEAKENED AS IT IS FORCED E BY INCOMING COLD FRONT.

LOOKING AHEAD...NEW AND STRONGER 1030 MB HIGH PRES REPLACES 
PRESENT ONE BY THU INCREASING NW-N WINDS ALONG COAST OF 
CALIFORNIA TO NEAR GALE FORCE.  STRONG NW WINDS AND 9-11 FT 
SWELL EXPECTED TO SPILL INTO WATERS S OF 30N.  UPPER LEVEL 
TROUGH SETS OVER BAJA CALIFORNIA AND OPENS POSSIBILITY OF
ANOTHER SET OF SHORT WAVES ENERGY SURGES CROSSING MEXICO INTO
GULF OF MEXICO.

$$
WALLY BARNES