000
AXPZ20 KNHC 040957
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAY 04 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... MONSOON 
TROUGH AXIS 11N86W TO 08N96W TO 09N101W THEN ITCZ TO 10N104W TO 
05N140W.  SCATTERED MODERATE TO STRONG WITHIN 150 NM OF AXIS 
FROM 94W TO 111W.  ISOLATED MODERATE WITHIN 90 NM OF AXIS FROM 
103W TO 118W.

...DISCUSSION...
WELL DEFINED UPPER LEVEL CYCLONE AT 27N137W WITH ASSOCIATED
TROUGH TO 12N137W BRING SWATH OF DRY AIR MASS INTO E PAC N OF 19N
W OF 115W.  REMAINDER OF BASIN UNDER BROAD RIDGE ANCHORED BY 
ANTICYCLONE AT 07N104W.  DIVERGENT FLOW BETWEEN RIDGE CREST AND 
CYCLONE INCREASE CONVECTION FROM 30N TO 32N W OF 125W. 
ANTICYCLONE OVER ITCZ PROMOTES DIVERGENCE ALOFT ENHANCING 
SCATTERED MODERATE TO STRONG CONVECTION FROM 100W-110W.

...ELSEWHERE AT THE LOWER LEVELS... 
BROAD HIGH PRES CENTER 1036 MB WELL N OF BASIN HAS SURFACE RIDGE
EXTEND SE TO 15N115W.  WEAKENING RIDGE FORCED NE BY APPROACHING
LOW PRES STILL WELL NW OF E PAC.  RIDGE PROVIDES BASIN WITH 
GENTLE TO MODERATE ANTICYCLONIC FLOW. 

GULF OF TEHUANTEPEC...SCATTEROMETER WIND PASS AT 0404 UTC OVER 
REGION CONFIRMED MINIMAL 35 KT GALE FORCE WINDS.  MODEL GUIDANCE 
EXPECTED SEAS AS HIGH AS 14-15 FT...BUT GIVEN THE MINIMAL GALE 
FORCE...ITS SHORT DURATION AND FETCH AND SMALL AFFECTED AREA...
FORECAST DOES NOT GO ABOVE 12 FT THIS MORNING BEFORE SUBSIDING
LATER TODAY.  SHIP REPORTS NEAR...BUT NOT WITHIN REGION OF GALE
...SHOW ONLY 7 AND 9 FT.  WINDS QUICKLY DIMINISH EARLY TODAY AND
BECOME A MODERATE NE BREEZE BY LATE TODAY AND TONIGHT.  SWELL 
8-10 FT WILL LINGER DOWNSTREAM FROM ITS SOURCE THROUGH LATE SUN. 

$$
WALLY BARNES