000
AXPZ20 KNHC 201003
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC SUN SEP 20 2015

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 
0945 UTC.               

...SPECIAL FEATURES...

AN ELONGATED AREA OF LOW PRES IS LOCATED ABOUT 250 MILES S-SW OF 
THE SOUTHERN TIP OF BAJA CALIFORNIA. LAST VISIBLE IMAGERY FROM 
YESTERDAY SHOWED MORE THAN ONE LOW CLOUD SWIRL WITHIN THIS AREA 
OF LOW PRES. THE MAIN LOW CENTER IS APPROXIMATED TO BE NEAR 
23N113W WITH A PRES OF 1003 MB. LATEST SATELLITE REVEALS 
CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE 
GULF OF CALIFORNIA FROM 22N-25N BETWEEN 112W-114W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 30 NM OF A LINE 
FROM 20N114W TO 22N114W. THERE REMAINS THE POTENTIAL FOR THIS 
LOW TO DEVELOP INTO A TROPICAL DEPRESSION TODAY AS IT MOVES IN A 
N-NW DIRECTION...THEN WILL MOVE ACROSS PORTIONS OF BAJA THIS 
EVENING AND MON AND BEGIN TO ENCOUNTER A LESS FAVORABLE 
ENVIRONMENT FOR IT TO BECOME A TROPICAL CYCLONE. 

THE MONSOONAL FLOW WILL CONTINUE TO ADVECT ABUNDANT TROPICAL 
MOISTURE ACROSS SOUTHERN BAJA CALIFORNIA AND INTO CENTRAL 
PORTIONS AS WELL AS THE ADJACENT GULF AND MEXICAN STATES TO THE 
E THROUGH TODAY. THIS TROPICAL MOISTURE SHOULD THEN SPREAD 
FARTHER NW-N ACROSS NORTHERN BAJA CALIFORNIA...AND MAY REACH FAR 
SOUTHERN CALIFORNIA MON INTO TUE. INCREASING RAIN CHANCES SHOULD 
BE EXPECTED ACROSS THESE AREAS...EXTENDING INLAND ACROSS 
MAINLAND MEXICO TO THE W SLOPES OF THE SIERRA MADRES 
OCCIDENTALES...WITH THE POTENTIAL FOR HEAVY RAINS...FLASH 
FLOODING AND LANDSLIDES THROUGH THE WEEKEND. 

...TROPICAL WAVES... 

A TROPICAL WAVE AXIS IS ALONG 90W/91W FROM 05N TO 15N...MOVING W 
NEAR 15 KT. EARLIER DEEP CONVECTION NOTED WITH THE WAVE HAS 
DISSIPATED WITH ONLY ISOLATED TSTMS REMAINING OVER N CENTRAL
GUATEMALA.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 10N74W TO 
09N82W TO 11N93W TO 10N100W TO 13N107W WHERE IT REMAINS 
FRACTURED. IT RESUMES FROM LOW PRES NEAR 15N118W TO 10N130W TO 
LOW PRES NEAR 10N140W. SCATTERED MODERATE TO STRONG CONVECTION 
IS WITHIN 120 NM N OF THE TROUGH BETWEEN 120W-128W. SCATTERED 
MODERATE CONVECTION IS WITHIN 180 NM S OF THE TROUGH BETWEEN 
118W-120W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 
06N-11N BETWEEN 103W-111W.T
 
...DISCUSSION...

A 1024 MB HIGH IS CENTERED NW OF THE AREA NEAR 36N147W AND 
EXTENDS A RIDGE SE TO NEAR 25N131. THE PRES GRADIENT BETWEEN THE 
RIDGE AND MONSOON TROUGH IS PRODUCING MODERATE TO FRESH NE TRADE 
WINDS OVER MOST OF THE WESTERN PORTION. THIS IS RESULTING IN 
SEAS OF 7-9 FT FROM FROM 15N-22.5N W OF 130W. THE HIGH PRES 
CENTER WILL REMAIN NEARLY STATIONARY THROUGH THIS AFTERNOON 
...THEN REFORM INTO A RIDGE FROM 32N140W SE TO NEAR 23N130W BY 
MON AFTERNOON AS A COLD FRONT PASSES TO THE N OF THE AREA. THE 
PRES GRADIENT OVER THE WESTERN PORTION THEN WEAKENS ALLOWING FRO 
THE TRADE WINDS TO DIMINISH WITH SEAS LOWERING TO BELOW 8 FT.
 
GAP WINDS...N WINDS OF 20-25 KT ARE EXPECTED TO BEGIN ACROSS THE 
GULF OF TEHUANTEPEC LATE TONIGHT...THEN BRIEFLY DIMINISH MON 
AFTERNOON. THESE WINDS WILL THEN MATERIALIZE IN PULSING FASHION 
TO 25 KT...POSSIBLY TO 30 KT...WITH ASSISTANCE FROM NOCTURNAL 
DRAINAGE MON NIGHT THROUGH TUE NIGHT WITH SEAS TO 8 FT. 
 
$$
AGUIRRE