000
AXPZ20 KNHC 261600
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 UTC SUN MAY 26 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM 10N86W TO 11N89W TO 09N98W TO 
LOW PRES NEAR 11N110W 1010 MB TO 10N118W. ITCZ CONTINUES FROM 
10N118W TO 10N140W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION FROM 11N TO 15N BETWEEN 90W AND 105W. SCATTERED 
MODERATE CONVECTION WITHIN 120 NM S OF MONSOON TROF AXIS BETWEEN 
90W AND 100W.

...DISCUSSION...

THE MAIN FORECAST ISSUE E OF 110W REMAINS THE ACTIVE MONSOON 
TROUGH WITH ONE WELL DEFINED LOW PRES SYSTEM ALONG THE TROUGH 
NEAR 10N118W. AN OSCAT PASS FROM 0630 UTC SHOWED THIS WELL. 
CONVECTION HAS BEEN SPORADIC SINCE YESTERDAY HOWEVER AS THE 
CIRCULATION HAS MIGRATED TO THE UNFAVORABLE SE REGION OF AN 
UPPER ANTICYCLONE. THERE IS INITIALLY GOOD AGREEMENT AMONG GLOBAL 
AND ENSEMBLE MODELS IN THROUGH THE NEXT 48 HOURS SHOWING THE 
WEAK LOW PRES PERSISTING IN THE SAME VICINITY. THERE IS LESS 
CONFIDENCE HOWEVER BY 72 HOURS AS THE GFS BEGINS TO DEEPEN THE 
LOW AND SHIFT IT NE AHEAD OF THE APPROACHING MID/UPPER TROUGH.

THERE ARE TWO ADDITIONAL CIRCULATIONS FARTHER EAST ALONG THE 
MONSOON TROUGH BETWEEN 90W AND 105W SHOWING UP ON ANIMATED 
SATELLITE IMAGERY...BUT NOT REALLY PRESENTING IN ASCAT/OSCAT 
DATA OVER THE PAST FEW HOURS AND ARE NOT WELL DEFINED AT THE 
SURFACE. LARGE CLUSTERS OF CONVECTION PERSIST N OF THE MONSOON 
TROUGH BETWEEN 90W AND 105W...AIDED IN PART BY CONVERGENT 
EASTERLY FLOW N OF THE MONSOON TROUGH AIDED BY DIVERGENT FLOW 
ALOFT DUE TO AN UPPER TROUGH EXTENDING THROUGH CENTRAL MEXICO. 
GLOBAL AND ENSEMBLE MODELS ARE IN BETTER AGREEMENT SHOWING A 
BROAD SURFACE LOW PRES AREA COALESCING IN THE VICINITY OF 12N98W 
BY EARLY MON. CONFIDENCE IN THE MODEL SOLUTION DIMINISHES 
THROUGH MID WEEK REGARDING THE LOCATION AND INTENSITY OF THIS 
FEATURE...ALTHOUGH THERE IS BROAD CONSENSUS SHOWING LOW PRES 
WITHIN 150 NM OF THE COAST OF MEXICO BETWEEN 95W AND 100W.

MEANWHILE THE GENERAL LOWERING OF PRES ACROSS THE REGION E OF 
110W IS INDUCING MODEST GAP WIND FLOW THROUGH TEHUANTEPEC. 
SCATTEROMETER DATA INDICATED FRESH WINDS THIS MORNING...ALTHOUGH 
THIS HAS LIKELY DIMINISHED.

OVERNIGHT ASCAT DATA INDICATED A SMALL AREA FRESH TO STRONG 
TRADE WINDS FROM 11N TO 17N BETWEEN 125W AND 130W. THIS SOUTH OF 
A 1028 MB RIDGE CENTERED NEAR 34N138W. A SHARP UPPER TROUGH WILL 
MIGRATE TO THE E OF THE HIGH PRES TONIGHT...ALLOWING THE RIDGE 
TO BUILD SLIGHTLY AND ENHANCE TRADE WIND FLOW THROUGH TUE. FRESH 
TO STRONG NW TO N FLOW IS NOTED BETWEEN THE HIGH PRES AND THE 
COAST OF SOUTHERN CALIFORNIA. THIS WILL SHIFT S OF 32N THROUGH 
MON ALONG THE COAST OF NORTHERN BAJA REACHING AS FAR S AS 25N 
THROUGH TUE.
 
$$ 
CHRISTENSEN