000
AXPZ20 KNHC 182140
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN AUG 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 EXTENDS FROM 10N85W THROUGH LOW PRES NEAR 11N103W 
1009 MB TO BEYOND 13N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS WITHIN 60 NM EITHER SIDE OF TROUGH BETWEEN 108W 
AND 112W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF A LINE 
FROM 18N115W TO 12N124W. SCATTERED MODERATE CONVECTION IS WITHIN 
60 NM OF THE TROUGH W OF 134W.

...DISCUSSION...                                              
BROAD UPPER LEVEL ANTICYCLONE CENTERED NEAR 21N135W DRIFTING W 
CONTINUES TO DOMINATE MOST OF NW PORTION OF AREA. DIFFLUENT FLOW 
ALOFT IN SW PERIPHERY OF RIDGE HELPING SUSTAIN ACTIVE CONVECTION 
NEAR MONSOON TROUGH W OF 134W. MID-UPPER LEVEL LOW NEAR 22N117W 
WITH TROUGH SSW TO 18N120W BEING STRETCHED NNE TO SSW... WITH 
MAJORITY OF ENTRAINED MOISTURE AND ENERGY BEING PULLED NWD IN 
RESPONSE TO DIGGING DEEP LAYERED CYCLONE ALONG COAST OF CENTRAL 
CALIFORNIA. THIS MID LATITUDE TROUGH IS FORECAST TO DIG SSW 
ALONG 125W BY LATE TUE...ALLOWING HIGH AMPLITUDE RIDGE CURRENTLY 
ACROSS W MEXICO TO SHIFT W. 

HIGH PRES CENTERED NW OF AREA NEAR 37N141W EXTENDS BROAD RIDGE 
SE TO NEAR 21N116W. A MODEST PRES GRADIENT S OF THE NE PACIFIC 
RIDGE WAS YIELDING NE TO ENE TRADES AROUND 20 KT W OF 134W FROM 
16N TO THE TROUGH AXIS ALONG 11N...FORCING SCATTERED CONVECTION. 

ABUNDANT TROPICAL MOISTURE E OF 110W PROVIDING A CONDITIONALLY 
UNSTABLE ENVIRONMENT FOR ACTIVE CONVECTION ACROSS THE REGION. 
COMPUTER MODEL GUIDANCE SUGGESTS A FAVORABLE REGION WILL DEVELOP 
ALONG THE MONSOON TROUGH BETWEEN 100W AND 115W DURING THE NEXT 
SEVERAL DAYS THAT WOULD YIELD ONE OR MORE SURFACE LOWS...WHICH 
COULD POTENTIALLY DEVELOP INTO TROPICAL CYCLONES. THIS REGION 
HAS A HIGH CHANCE FOR TROPICAL DEVELOPMENT IN THE NEXT 5 DAYS. 
 
$$ 
MUNDELL