000
AXPZ20 KNHC 271530
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI SEP 27 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...           
THE MONSOON TROUGH IS ALONG 09N84W TO 09N87W TO 10N93W. THE AXIS 
RESUMES NEAR A 1008 MB LOW PRES NEAR 17N105W TO A 1011 MB LOW 
PRES NEAR 13N115W TO 12N140W. WIDELY SCATTERED MODERATE FROM 04N 
TO 08N BETWEEN 77W AND 79W AND FROM 04N TO 11N BETWEEN 85W AND 
97W. SCATTERED MODERATE FROM 15N TO 20N BETWEEN 105W AND 108W 
AND WITHIN 120 NM EITHER SIDE OF A LINE FROM 13N115W TO 10N126W.

...DISCUSSION...                                            
WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL TROUGH 
PROGRESSING EASTWARD OVER THE WESTERN CONUS WITH A TROUGH AXIS 
EXTENDING FROM SOUTHERN CALIFORNIA NEAR 33N116W SW TO A BROAD 
BASE NEAR 31N124W. THIS IS PROVIDING THE DISCUSSION AREA N OF 
20N WITH PRIMARILY WEST-SOUTHWESTERLY FLOW ALOFT IN A FAIRLY DRY 
AND STABLE AIRMASS. ONE EXCEPTION TO THE MOSTLY STABLE 
CONDITIONS RESULTING AT THE SURFACE ACROSS THIS AREA N OF 20N IS 
THAT THE UPPER LEVEL TROUGHING SUPPORTS A COLD FRONT ANALYZED 
FROM SE ARIZONA NEAR 31N110W TO 28N117W. WITH THE PRESENCE OF 
THE FRONT...NW TO N WINDS ARE FORECAST IN THE RANGE OF 20 TO 25 
KT IN THE EXTREME NORTHERN GULF OF CALIFORNIA THROUGH EARLY 
SATURDAY WITH SEAS REMAINING BELOW 8 FT. OTHERWISE...AS THIS 
UPPER LEVEL SYSTEM PASSES TO THE EAST...NW SWELL IS MAINTAINING 
SEAS IN THE RANGE OF 8 TO 11 FT N OF 23N BETWEEN 116W AND 133W 
WHICH IS EXPECTED TO SUBSIDE WITHIN 24 HOURS.

THE OTHER MAIN FEATURE NOTED ON WATER VAPOR IMAGERY IS A BROAD 
ANTICYCLONIC CIRCULATION CENTERED NEAR 18N106W. W OF 106W...A 
DIFFLUENT MIDDLE TO UPPER LEVEL ENVIRONMENT WITHIN THE 
SOUTHWESTERN QUADRANT OF THE UPPER LEVEL RIDGE IS SUSTAINING 
CONVECTION ALONG THE MONSOON TROUGH BETWEEN 115W AND 126W AND 
SUPPORTIVE OF A WEAK 1011 MB LOW EMBEDDED WITHIN THE AXIS NEAR 
13N115W. THE MAIN IMPACT ASSOCIATED WITH THE LOW IS SEAS TO 8 FT 
IN ITS VICINITY WITH ADDED WAVE ENERGY CONTRIBUTED FROM NW 
SWELL. E OF 106W...NORTHEASTERLY FLOW ALOFT ORIGINATES OVER THE 
WESTERN CARIBBEAN SEA...TRAVERSING OVER CENTRAL AMERICA AND INTO 
THE EAST PACIFIC BECOMING DIFFLUENT W OF 90W TO 102W. THE UPPER 
LEVEL DIFFLUENT PATTERN IS PROVIDING A FAVORABLE ENVIRONMENT FOR 
SCATTERED MODERATE CONVECTION IN THE VICINITY OF A BROAD 
MONSOONAL GYRE CENTERED NEAR 09N91W. THE INFLUENCE OF THIS GYRE 
AND THE ASSOCIATED SCATTERED SHOWERS AND TSTMS GENERALLY ARE 
IMPACTING THE AREA FROM 04N TO 15N BETWEEN 86W AND 97W.

$$
HUFFMAN