000
AXPZ20 KNHC 270933
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN NOV 27 2011

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 09N84W TO 07N95W. ITCZ AXIS 07N95W TO 09N110W TO 
LOW PRES NEAR 09N121W TO 08N130W TO 09N140W. SCATTERED MODERATE 
CONVECTION IS NOTED WITHIN 90 NM S OF ITCZ AXIS BETWEEN 112W AND 
122W.

...DISCUSSION...

A RIDGE/TROUGH PATTERN DOMINATES MOST OF THE FORECAST WATERS N 
OF 10N W OF 100W. A LONG WAVE UPPER TROUGH CONTINUES TO PROGRESS 
SLOWLY E ACROSS CENTRAL N AMERICA WITH ITS MEAN AXIS EXTENDING S 
AND SW ACROSS TEXAS AND NW MEXICO THEN THROUGH SOUTHERN BAJA 
CALIFORNIA INTO THE DISCUSSION AREA TO NEAR 11N121W. AN 
ANTICYCLONIC CIRCULATION CENTERED NEAR 11N136W EXTENDS A RIDGE 
NE BEYOND 32N121W. W OF THE RIDGE...ANOTHER LONG WAVE UPPER 
TROUGH IS APPROACHING THE FAR NW CORNER OF THE FORECAST AREA. 
THE ASSOCIATED COLD FRONT IS JUST CLIPPING THE REGION AND 
EXTENDS FROM 30N139W TO 29N140W. NLY WINDS OF 20-25 KT ARE 
EXPECTED W OF THE FRONT AS WELL AS LONG PERIOD NW SWELL WITH 
BUILDING SEAS OF 12 TO 16 FT. THE FRONT IS FORECAST TO MOVE W OF 
140W IN ABOUT 24 HOURS AS HIGH PRES STRENGTHENS N OF FORECAST 
REGION. PRES GRADIENT BETWEEN HIGH PRES AND THE FRONT WILL 
PRODUCE AN AREA OF E TO SE WINDS OF 20 TO 25 KT MAINLY N OF 20N 
W OF 135W IN ABOUT 48 HOURS. 

THE REMNANTS OF KENNETH ARE STILL NOTED ON SATELLITE IMAGERY AS 
A WELL DEFINED SWIRL OF LOW CLOUDS WITH A FEW SHOWERS SPINNING 
NEAR 14N138W. A SURFACE TROUGH IS ANALYZED ON THE 0600 UTC 
SURFACE MAP AND EXTENDS 19N137W TO 12N137W. A TIGHT PRES 
GRADIENT BETWEEN A 1026 MB HIGH CENTERED NEAR 32N126W AND THIS 
TROUGH IS PRODUCING A LARGE AREA OF NE WINDS OF 20 KT E OF 
TROUGH TO ABOUT 118W...WITH SEAS OF UP TO 12 FT IN MIXED NE AND 
NW SWELL. SCATTEROMETER PASSES CONFIRMED THE PRESENCE OF THESE 
WIND SPEEDS. 

GULF OF CALIFORNIA...NW WINDS OF 20 TO 25 KT ARE BLOWING ACROSS 
THE GULF OF CALIFORNIA PER THE MOST RECENT ASCAT PASS. A FEW 
SHIP OBSERVATIONS ALSO INDICATED THE PRESENCE OF NLY WINDS OF 20 
KT JUST OFF THE BAJA CALIFORNIA PENINSULA...PARTICULARLY BETWEEN 
25N AND 28N. THESE WINDS WILL CONTINUE THROUGH EARLY SUN BEFORE 
VEERING MORE NE THEN DIMINISHING SOME LATE SUN. WINDS ARE 
FORECAST TO DEGREASE BELOW 20 KT ACROSS THIS GULF BY MON.

ATTENTION REMAINS FOCUSED ON THE NEXT GULF OF TEHUANTEPEC WIND 
EVENT FORECAST TO BE A STRONGER ONE. NLY WINDS OF 20 TO 30 KT 
WILL BEGIN TO SURGE INTO THE AREA THIS MORNING (1500 UTC) AND 
QUICKLY INCREASE TO GALE FORCE EARLY THIS AFTERNOON (1800 UTC)  
COMPUTER MODEL GUIDANCE IS IN GENERAL AGREEMENT THAT WINDS WILL 
FURTHER INCREASE TO STORM FORCE (50 KT) BY THIS EVENING OR 
TONIGHT. SEAS ARE EXPECTED TO BUILD IN EXCESS OF 15-20 FT IN 
ASSOCIATION WITH THESE STORM FORCE WINDS TONIGHT. A STORM 
WARNING REMAINS IN EFFECT FOR THIS AREA. THIS GAP WIND EVENT IS 
FORECAST TO PEAK THIS EVENING THROUGH MON MORNING THEN DIMINISH 
TO GALE FORCE MON AFTERNOON AND CONTINUE THROUGH MON NIGHT. GALE 
CONDITIONS SHOULD END EARLY TUE MORNING BUT STRONG N WINDS MAY 
PERSIST THROUGH THE MIDDLE OF NEXT WEEK.  

THIS GAP WIND EVENT WILL BE ASSOCIATED WITH A STRONG COLD SURGE 
BEHIND A COLD FRONT CURRENTLY MOVING SE ACROSS THE GULF OF 
MEXICO. WHEN COLD AIR OUTBREAKS OCCUR OVER THE GULF OF MEXICO...
THE SIERRA MADRE MOUNTAINS BLOCK THE LARGE SCALE FLOW OF COLD 
AIR SOUTHWARD RESULTING IN THE DEVELOPMENT OF A STRONG 
NORTH-SOUTH PRES GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC. NLY 
FLOW IS THEN FUNNELED THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC. THIS GAP FLOW OFTEN RESULTS IN A NARROW JET OF WIND 
THAT CAN REACH GALE...STORM AND OCCASIONALLY HURRICANE FORCE.  

$$
GR