000
AXPZ20 KNHC 090917
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC FRI JAN 09 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 
0715 UTC. 

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...THE PRESSURE GRADIENT BETWEEN 
STRONG RIDGING EXTENDING S FROM THE NE COAST OF MEXICO TOWARD 
THE ISTHMUS OF TEHUANTEPEC AND TROUGHING TO THE S ALONG THE ITCZ 
IS SUPPORTING 40 KT GALE FORCE WINDS IN THE GULF OF TEHUANTEPEC 
THIS MORNING. THE RIDGE IS EXPECTED TO WEAKEN A BIT 
TODAY...ALLOWING WINDS TO DIP BELOW GALE FORCE BRIEFLY THIS 
AFTERNOON AND SAT AFTERNOON DURING THE DIURNAL MINIMUM OF 
DRAINAGE FLOW OFF THE LAND. OTHERWISE...A MINIMAL GALE IS 
FORECAST THROUGH THE END OF THE FORECAST PERIOD EARLY SUN 
MORNING. SEAS IN THE GULF OF TEHUANTEPEC ARE AS HIGH AS 18 FEET 
THIS MORNING ARE EXPECTED TO SUBSIDE TO 10-13 FEET BY THIS 
AFTERNOON WHERE THEY SHOULD REMAIN THROUGH EARLY SUN MORNING. 

GULF OF PAPAGAYO GALE WARNING...MINIMAL GALE CONDITIONS ARE 
BELIEVED TO BE IN PLACE THIS MORNING IN THE GULF OF PAPAGAYO AND 
ARE EXPECTED TO CONTINUE THROUGH THE END OF THE PERIOD OF PEAK 
DRAINAGE FLOW LATER THIS MORNING. AS MENTIONED ABOVE...THE RIDGE 
TO THE N IS EXPECTED TO DIMINISH SOME LATER TODAY. THIS WILL 
ALSO DIMINISH THE WINDS IN THE GULF OF PAPAGAYO AS IT WILL 
WEAKEN THE PRESSURE GRADIENT OVER THE AREA. WINDS WILL PULSE TO 
30 KT SAT MORNING AND TO 25 KT SUN MORNING AS THE PRESSURE 
GRADIENT CONTINUES TO WEAKEN.

NE SWELL FROM BOTH THE GULFS OF PAPAGAYO AND TEHUANTEPEC HAVE 
BROUGHT SEAS IN THE 8-12 FOOT RANGE TO MUCH OF THE DOWNSTREAM 
AREA E OF 130W. THIS AREA OF SEAS PRIMARILY ATTRIBUTED TO NE 
SWELL WILL SHRINK EASTWARD AS THE WINDS IN THE GAPS GENERALLY 
DIMINISH AND NW SWELL MOVES INTO WESTERN WATERS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 05N77W TO 04N79W TO 
05N85W. THE ITCZ AXIS WAS ANALYZED FROM 05N85W TO 06N87W TO 
03N98W TO 08N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 
NM N OF THE AXIS BETWEEN 113W AND 118W AND WITHIN 120 NM N OF 
THE AXIS BETWEEN 131W AND 135W. 
 
...DISCUSSION...                                                 

A COLD FRONT FROM 30N126W TO 22N133W IS IMPEDING ON 1018 MB HIGH 
PRESSURE LOCATED NEAR 24N125W. THIS HIGH EXTENDS A RIDGE ACROSS 
THE NE PART OF THE FORECAST AREA TO CABO CORRIENTES MEXICO. THE 
COLD FRONT IS EXPECTED TO OCCLUDE TODAY THEN GRADUALLY WEAKEN AS 
THE MAIN UPPER SUPPORT FOR THE BOUNDARY ADVANCES AHEAD OF THE 
SURFACE BOUNDARY AND A WEAKER UPPER SYSTEM MOVES IN. THE MAIN 
IMPACT OF THE FRONT IS NW SWELL...WITH PERIODS IN THE 19-21 
SECOND RANGE CURRENTLY ALONG THE COAST OF BAJA CALIFORNIA NORTE 
AND EXPECTED TO MOVE S ALONG THE REMAINDER OF THE BAJA 
CALIFORNIA PENINSULA LATER TODAY. OVER NW WATERS...SEAS AS HIGH 
AS 12 FT ARE CURRENTLY IN PLACE BUT ARE EXPECTED TO DIMINISH 
NEAR THE FRONT OVER THE NEXT FEW DAYS. THE NW SWELL PROPAGATING 
S OF 20N WILL MEET UP WITH AN AREA OF FRESH TO OCCASIONALLY 
STRONG TRADE WINDS W OF 120W LATER TODAY...PRODUCING SEAS IN THE 
8-12 FT RANGE. THE TRADES OVER W WATERS WILL BE DRIVEN BY THE 
PRESSURE GRADIENT BETWEEN THE ITCZ AND STRONGER HIGH PRES BEHIND 
THE COLD FRONT. 

FRESH TO LOCALLY STRONG N WINDS ARE FUNNELING INTO THE GULF OF 
PANAMA FROM THE CARIBBEAN. WINDS WILL PULSE TO 25 KT DURING THE 
LATE NIGHT AND EARLY MORNING HOURS THROUGH SAT MORNING AND 
DIMINISH TO 20 KT OR LESS DURING THE AFTERNOON AND EARLY EVENING 
HOURS. 

$$ 
SCHAUER