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Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 270333
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC TUE JAN 27 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC. 

...SPECIAL FEATURES...                                           
GULF OF TEHUANTEPEC GALE WARNING...PERSISTENT HIGH PRES ACROSS 
THE WESTERN GULF OF MEXICO CONTINUES TO MAINTAIN A TIGHT PRES 
GRADIENT ACROSS SE MEXICO INTO THE GULF OF TEHUANTEPEC. THIS IS 
SUPPORTING GALE FORCE WINDS ACROSS THE AREA. WINDS WILL CONTINUE 
TO REACH 35-40 KT DURING THE OVERNIGHT AND EARLY MORNING 
HOURS...THEN WILL SLIGHTLY DIMINISH TO MINIMAL GALE FORCE DURING 
THE AFTERNOON AND EVENING HOURS THROUGH AT LEAST THE NEXT 48 
HOURS. SEAS ARE FORECAST TO BUILD TO 10-16 FT IN THE GULF DURING 
THE PERIOD OF STRONGEST WINDS. A GALE WARNING REMAINS IN EFFECT. 
NE TO E SWELLS ASSOCIATED WITH THIS EVENT COMBINED WITH STRONG 
WINDS ACROSS THE GULF OF PAPAGAYO IS PRODUCING A LARGE AREA OF 
SEAS 8 FT OR GREATER THAT EXTENTS SW TO BEYOND 110W. BY WED 
MORNING...SEAS 8 FT OR GREATER WILL COVER MUCH OF THE AREA FROM 
03N TO 13N BETWEEN 92W AND 120W. THIS GALE WIND EVENT IS 
FORECAST TO BE OF LONG DURATION...LASTING THROUGH MUCH OF THE 
WEEK.

GULF OF PAPAGAYO GALE WARNING...A TIGHT PRES GRADIENT WILL ALSO 
PERSIST ACROSS THE WESTERN CARIBBEAN ASSOCIATED WITH A HIGH PRES 
RIDGE THERE. THIS WILL COMBINE WITH STRONG TRADE WINDS ACROSS 
THE SOUTH CENTRAL CARIBBEAN TO SUPPORT MINIMAL GALE FORCE WINDS 
ACROSS THE GULF OF PAPAGAYO LATE TUE NIGHT INTO WED MORNING AND 
PROBABLY LATE WED NIGHT INTO THU MORNING. FRESH TO STRONG WINDS 
WILL EXTEND SW AND DOWNWIND OF THE GULF TO 90W-91W. EXPECT 
BUILDING SEAS TO AROUND 11 FT WITH THE STRONGEST WINDS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 02N78W TO 03N83W TO 05N88W. THE 
ITCZ CONTINUES FROM 05N88W TO 06N110W TO 10N130W TO 07N140W. 
SCATTERED MODERATE CONVECTION IS NOTED FROM 03N TO 06N BETWEEN 
91W AND 96W...AND FROM 01N TO 04N BETWEEN 85W AND 87W. 

...DISCUSSION...                                                
ALOFT...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE FORECAST 
AREA W OF 100W. THE STRONG CUT-OFF LOW HAS MOVED JUST N OF AREA 
AND NOW IS CENTERED NEAR 32N126W WITH A TROUGH EXTENDING FROM 
THE LOW TOWARD NORTHERN BAJA CALIFORNIA AND NW MEXICO. TO THE W 
OF THE UPPER LOW AND TROUGH...A NARROW RIDGE IS ALONG 130W N OF 
21N...AND IS SLIDING EASTWARD. A RATHER NARROW LONGWAVE WAVE 
TROUGH IS OVER THE WESTERN PORTION OF THE AREA ALONG 136W AND N 
13N. OVER THE FAR EASTERN PORTION OF THE AREA...BROAD MID/UPPER 
LEVEL RIDGING IS PRESENT E OF ABOUT 100W WITH A RIDGE AXIS 
STRETCHING FROM THE TEXAS PANHANDLE SEWD TO SE MEXICO...AND TO 
ACROSS CENTRAL AMERICA. 

AT THE SURFACE...A COLD FRONT IS OVER THE FAR NW CORNER OF THE 
AREA AND EXTENDS FROM 30N136W TO A 1013 MB WEAK LOW PRES NEAR 
28N137W TO 24N140W. THE MOST RECENT SCATTEROMETER PASS SHOWED 
FRESH TO STRONG NORTHERLY WINDS W OF THE LOW AND FRONT. EAST OF 
THE FRONT...A WEAK PRES GRADIENT PREVAILS AS HIGH PRES LOCATED N 
OF AREA DISSIPATES. MAINLY GENTLE WINDS ARE NOTED ACROSS THE N 
WATERS E OF THE FRONT. A SURFACE TROUGH EXTENDS FROM 26N115W TO 
20N116W. A SMALL AREA OF E TO SE WINDS IN THE 15-20 KT RANGE IS 
OBSERVED FROM 25N TO 27N E OF TROUGH TO 113W WITH SEAS TO AROUND 
9 FT. THIS TROUGH IS FORECAST TO WEAKEN THROUGH TONIGHT...AND 
DISSIPATE ON TUE. THE COLD FRONT WILL BECOME STATIONARY ON TUE 
AND DISSIPATE BY WED...THEN A RIDGE IS EXPECTED TO BUILD ACROSS 
THE N WATERS.  

LONG PERIOD NW SWELLS DOMINATE MUCH OF THE FORECAST WATERS AND 
ARE CURRENTLY MIXING WITH THE SHORT PERIOD WIND WAVES GENERATING 
IN THE GAP WIND REGIONS OF TEHUANTEPEC AND PAPAGAYO. ADDITIONAL 
PULSES OF NW SWELLS RELATED TO THE AFOREMENTIONED COLD FRONT ARE 
PROPAGATING SEWD TO THE W OF A LINE FROM 30N120W TO 14N130W TO 
04N136W. THESE SWELLS ARE RESULTING IN MAX COMBINED SEAS OF UP 
TO 11 FT. 

GAP WINDS...                                                  
SEE SPECIAL FEATURES FOR DETAILS. 

FRESH TO STRONG N WINDS ARE FUNNELING INTO THE GULF OF PANAMA 
FROM THE CARIBBEAN SEA REACHING TO NEAR 05N BETWEEN 79W-81W. 
THESE WINDS WILL CHANGE LITTLE THROUGH WED WITH SEAS THERE TO 8 
OR 9 FT.

$$ 
GR