000
AXPZ20 KNHC 051003
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC THU NOV 05 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.               

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH AXIS EXTENDS FROM NW COLOMBIA W TO 09N84W TO 
10N96W TO LOW PRES NEAR 07N104W 1008 MB TO 07N110W. IT RESUMES 
AT LOW PRES NEAR 14N110W 1011 MB TO LOW PRES NEAR 14N117W 1009 
MB TO 09N123W. ITCZ AXIS THEN EXTENDS FROM 07N123W TO 08N130W TO 
10N140W. SCATTERED STRONG CONVECTION IS WITHIN 120 NM N OF THE 
TROUGH BETWEEN 112W-114W. SCATTERED MODERATE CONVECTION IS 
WITHIN 120 NM S OF THE TROUGH BETWEEN 94W-98W.

...DISCUSSION...

A SHARP UPPER TROUGH IS OVER WESTERN UNITED STATES WITH ITS BASE 
EXTENDING SW TO NORTHERN GULF OF CALIFORNIA AND TO A BASE NEAR 
20N131W. AN ASSOCIATED DISSIPATING COLD FRONT CONTINUES TO 
QUICKLY MOVE SOUTHWARD...AND EXTENDS FROM THE TEXAS PANHANDLE SW 
TO LOS MOCHIS MEXICO...TO BAJA CALIFORNIA SUR NEAR 24N111W AND 
TO 20N118W TO 21N115W TO 19N123W TO 18N135W. GENERALLY MODERATE 
TO FRESH NW FLOW FOLLOWS THE FRONT ALONG THE PACIFIC COAST OF 
THE BAJA CALIFORNIA PENINSULA. THE FRESH TO STRONG SW TO W WINDS 
THAT WERE RECENTLY ACROSS PORTIONS OF THE FAR NORTHERN GULF OF 
CALIFORNIA APPEAR TO BE DIMINISHING TO MOSTLY FRESH IN 
INTENSITY. THE UPPER TROUGH WILL LIFT NE THROUGH THIS EVENING 
WITH THE DISSIPATING COLD FRONT BECOMING A FRACTURED CLOUD LINE 
ON SATELLITE IMAGERY. 6-8 FT SEAS IN NW SWELL OFF THE BAJA 
CALIFORNIA NORTE COAST ARE FORECAST TO SUBSIDE TO LESS THAN 8 FT 
THROUGH THIS AFTERNOON. HIGH PRESSURE OF 1029 MB N OF THE AREA 
AT 34N139W EXTENDS A RIDGE SE TO 27N126W TO 26N120W AND TO 
22N114W. A TIGHT PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER 
PRESSURE NEAR THE WESTERN PART OF THE FRONT...AND A TROUGH JUST 
W OF THE AREA IS ALLOWING FOR NE-E 20-25 KT TO EXIST FROM 17.5N 
TO 20.5N W OF 133W WITH SEAS TO 10 FT. OVERNIGHT SCATTEROMETER 
DATA HIGHLIGHTED THESE WINDS. THIS AREA OF WINDS WILL GRADUALLY 
SHRINK THROUGH LATE TONIGHT...AND BY LATE FRI NIGHT THESE WINDS 
WILL WEAKEN TO 15-20 KT FROM 13N-20N W OF 133W...AND ALSO FROM 
14N-18N BETWEEN 118W-133W WITH SEAS TO 9 FT IN MIXED SWELL.

MODELS SHOW THAT THE PRESSURE GRADIENT BETWEEN RIDGING OVER THE 
PACIFIC WATERS W OF BAJA CALIFORNIA AND TROUGHING ALONG THE W 
COAST OF NW MEXICO WILL INDUCE A SURGE OF NW 20-25 KT WINDS 
ACROSS GULF OF CALIFORNIA BEGINNING TONIGHT. THESE WINDS THEN 
SUBSIDE TO 15-20 KT BY AFTERNOON AND MATERIALIZE AGAIN FRI 
EVENING FR0M 25N-28N...CONTINUING INTO SAT. SEAS ARE EXPECTED TO 
BUILD TO AROUND 7 FT IN THE FAR SOUTHERN PART OF THE GULF LATE 
FRI WITH SEAS ELSEWHERE IN THE GULF IN THE RANGE OF 4-6 FT. 
 
GULF OF TEHUANTEPEC...A QUICK SURGE OF N-NE 20-25 KT GAP WINDS 
WITHIN 30 NM OF A LINE FROM 16N95W TO 15N95.5W WILL SEAS TO 8 FT 
WILL DIMINISH EARLY THIS AFTERNOON. THE SEAS WILL SUBSIDE TO 
LESS THAN 8 FT BY EARLY THIS EVENING. BEYOND 48 HOURS...MODELS 
ARE SUGGESTING THAT A STRONGER GAP WIND EVENT IS LIKELY TO OCCUR 
COMMENCING EARLY ON SUN. WILL HAVE TO MONITOR MODEL TRENDS FOR 
POSSIBILITY OF THESE WINDS REACHING GALE FORCE LATE SUN.
 
WEAK LOW PRES WILL PERSIST ALONG THE MONSOON TROUGH BETWEEN 102W 
AND 107W THROUGH 48 HOURS. THIS WILL SUPPORT 15-20 KT S TO SW 
FLOW INTO THE MONSOON TROUGH WHICH IN TURN WILL KEEP SEAS TO 8 
FT WITHIN ABOUT 300 NM S AND SE OF THE LOW THROUGH TONIGHT. THE 
8 FT SEAS WILL SUBSIDE TO LESS THAN 8 FT FRI AFTERNOON AS THE 
SWELL DECAYS AND THE LOW BECOMES LESS DEFINED.

$$
AGUIRRE