000
AXPZ20 KNHC 260928
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC THU DEC 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

MONSOON TROUGH EXTENDS FROM 04N77W TO 03N83W. ITCZ CONTINUES 
FROM 03N83W TO 06N96W TO 07N112W TO 06N125W TO 10N135W TO 
09N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS 
FROM 08N TO 11N BETWEEN 126W AND 129W. SIMILAR CONVECTION IS 
NOTED FROM 11N TO 14N BETWEEN 132W AND 134.5W.

...DISCUSSION... 

A HIGH PRES OF 1029 MB LOCATED WELL N OF AREA NEAR 44N128W 
EXTENDS A WEAK RIDGE ACROSS THE N WATERS TO NEAR 20N110W. THIS 
SYSTEM WILL REMAIN NEARLY STATIONARY WHILE A NEW HIGH PRES 
CENTER IS FORECAST TO DEVELOP NEAR 34N137W IN ABOUT 24 HOURS. 

LARGE SCALE UPPER LEVEL DIVERGENCE E OF A CUT-OFF UPPER LOW 
CENTERED NEAR 16N148W IS PRODUCING AN EXTENSIVE PLUME OF DEEP 
LAYER MOISTURE WITH EMBEDDED LIGHT TO MODERATE SHOWERS OVER A 
LARGE PART OF THE DISCUSSION AREA W OF 130W. A SURFACE TROUGH 
INDUCED BY THIS UPPER LEVEL FEATURE EXTENDS FROM 20N138W TO 
11N137W. SCATTEROMETER DATA SHOWED AN AREA OF FRESH TO STRONG 
WINDS E OF THE TROUGH AXIS TO NEAR 130W. PRES GRADIENT BETWEEN 
THE TROUGH AND HIGH PRES TO THE NORTH IS ALSO RESULTING IN AN 
AREA OF NE TO E WINDS OF 20-25 KT NEAR THE NORTHERN END OF THE 
TROUGH AXIS THAT WILL MOVE IN TANDEM WITH THE TROUGH OVER THE 
NEXT COUPLE OF DAYS. THE TROUGH IS FORECAST TO BE W OF AREA IN 
ABOUT 48 HOURS. THE 0606 ASCAT PASS INDICATES THE PRESENCE OF 
THESE FRESH TO STRONG WINDS COVERING MAINLY FROM 17N TO 22N W OF 
135W. SEAS OF 8-11 FT ARE IN ASSOCIATION WITH THE TROUGH PER 
THE MOST RECENT ALTIMETER PASS.

PRES GRADIENT BETWEEN STRONG HIGH PRES OVER THE GREAT BASIN AND 
A SURFACE TROUGH ALONG THE W COAST OF MEXICO FROM 21N105W TO 
32N112W IS PRODUCING NW WINDS OF 20-25 KT ACROSS THE GULF OF 
CALIFORNIA MAINLY N OF 27N. LITTLE CHANGE IS EXPECTED OVER THE 
NEXT 24 HOURS.

AN EARLIER ASCAT PASS DIRECTLY OVER GULF OF TEHUANTEPEC PROVIDED 
OBSERVATIONS OF NORTHERLY WINDS IN THE 20-30 KT RANGE THROUGH 
THE GULF. WINDS AND SEAS WILL CONTINUE TO DIMINISH THE REST OF 
TODAY IMMEDIATELY DOWNSTREAM FROM THE GULF...WHILE A LARGE AREA 
OF 8-10 FT NE SWELL GENERATED BY GALES THE PAST 24-36 HOURS WILL 
SPREAD AND EXPAND EASTWARD TO AROUND 110W-111W THIS MORNING. 
LOOKING AHEAD...MARINE GUIDANCE SUGGESTS PEAK WINDS APPROACHING 
MINIMAL GALE FORCE ONCE AGAIN IN THE GULF OF TEHUANTEPEC N OF 
15N EARLY SAT MORNING.

PULSING OF NOCTURNAL WINDS ARE ALSO EXPECTED ACROSS THE GULF OF 
PAPAGAYO REACHING AROUND 25 KT FROM 0600 TO 1200 UTC...WITH SEAS 
OF 6-7 FT THROUGH AND DOWNWIND OF THE GULF. AN ASCAT PASS 
CONFIRMED THE PRESENCE OF THESE WINDS.

LONG PERIOD NW SWELL MOVING INTO NW PORTION WILL SPREAD SE AND 
AFFECT MOST OF THE WATERS W OF 110W BY FRI...AND W OF 100W BY 
SAT. 
 
$$
GR