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Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 121602
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAR 12 2014

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.                           

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...A COLD FRONT MOVING ACROSS 
THE NW GULF OF MEXICO THIS MORNING WILL SWEEP SOUTHWARD ACROSS 
THE WESTERN GULF OF MEXICO THROUGH TONIGHT. THE DENSER AIRMASS 
BEHIND THE FRONT WILL FUNNEL ACROSS THE ISTHMUS OF TEHUANTEPEC 
AND INTO THE GULF OF TEHUANTEPEC EARLY THU MORNING. THIS AIRMASS 
WILL MIX DOWN TO THE SURFACE RESULTING IN NLY WINDS REACHING TO 
GALE FORCE STRENGTH WITH SEAS BUILDING TO 15 FT BY EARLY THU 
AFTERNOON. THE WINDS AND SEAS WILL GRADUALLY DIMINISH INTO FRI 
AS THE HIGH PRES BEHIND THE FRONT SHIFTS EASTWARD ACROSS THE 
NORTHERN GULF OF MEXICO. 

A LARGE PLUME OF SHORT PERIOD NE SWELLS RANGING FROM 8 TO 12 FT 
GENERATED BY THE TEHUANTEPEC EVENT WILL MIX WITH LONGER PERIOD 
NW SWELL OVER THE WATERS FROM 10N TO 14N BETWEEN 94W AND 105W BY 
EARLY FRI...HOWEVER THESE SWELLS WILL BE SHORT-LIVED AS 
WAVEWATCH GUIDANCE DEPICTS THEM TO DECAY TO BELOW 8 FT BY FRI 
EVENING.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

MONSOON TROUGH EXTENDS FROM 10N86W TO 05N98W. THE ITCZ AXIS 
EXTENDS FROM 05N98W TO 03N106W TO 03N115W TO 03N120W TO 01N130W. 
NO SIGNIFICANT CONVECTION.

...DISCUSSION... 

SATELLITE WATER VAPOR IMAGERY SHOWS A NEGATIVELY TILTED UPPER 
TROUGH THAT EXTENDS FROM NEAR 22N117W SE TO 18N112W WHERE IT 
BROADENS SSE TO 13N112W TO NEAR 00N105W. DIVERGENCE ALOFT E OF 
THE TROUGH IS HELPING TO SUSTAIN AN AREA OF WIDELY SCATTERED 
SHOWERS AND TSTMS FROM 03N TO 10N BETWEEN 103W-111W. MODEL 
GUIDANCE IS IN AGREEMENT WITH THE WATER VAPOR IMAGERY THAT A 
SPLIT FLOW PATTERN HAS SET UP ALOFT N OF THE HAWAIIAN 
ISLANDS...WITH THE SOUTHERN STREAM CARVING AROUND THE BASE OF A 
SHARP UPPER TROUGH ROUGHLY ALONG 145W EXTENDING S TO NEAR 10N. 
DIVERGENCE ALOFT E OF THE TROUGH IS RESULTING IN A VERY 
NOTICEABLE AREA OF OVERCAST MULTILAYERED CLOUDS WITH NUMEROUS 
SHOWERS AND ISOLATED TSTMS OVER THE FAR WESTERN PORTION OF THE 
DISCUSSION AREA FROM 09N TO 10N W OF 131W. AN UPPER LEVEL 
DIFFLUENT FLOW PATTERN TO THE SE OF THE TROUGH IS BRINGING 
OVERCAST TO BROKEN MOSTLY MID AND HIGH CLOUDS FROM 03N TO 09N W 
OF 129W. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE 
UNDERNEATH THESE CLOUDS. FAST UPPER LEVEL WLY FLOW IS ADVECTING 
SOME OF THE HIGH CLOUDS EASTWARD TO NEAR 127W WHERE THEY 
DISSIPATE IN DRY UPPER LEVEL ENVIRONMENT.

GLOBAL MODEL GUIDANCE SUGGEST THAT A SMALL UPPER LOW MOVING E 
NEAR 31N130W WITH A TRAILING TROUGH SW TO NEAR 24N132W WILL 
QUICKLY SHIFT EASTWARD TO THE FAR NE PORTION OF THE AREA BY THU 
AFTERNOON WITH THE TRAILING TROUGH COMING INTO PHASE WITH THE 
AFOREMENTIONED TROUGH CURRENTLY W OF THE DISCUSSION AREA ALONG 
145W. AN UPPER LOW IS FORECAST TO DEVELOP ON THE SOUTHERN TAIL 
END OF THE TROUGH ON FRI NEAR 13N140W. BROAD UPPER ANTICYCLONIC 
FLOW WILL FOLLOW IN THE WAKE OF THE TROUGH. AT THE SURFACE...A 
RIDGE PRESENTLY EXTENDING FROM 32N134W SE TO NEAR 19N119W WILL 
BE REINFORCED BY AN AREA OF STRONGER HIGH PRES THAT BUILDS S AND 
SW OVER MUCH OF THE FORECAST AREA THU AND FRI. A TIGHTENING 
PRES GRADIENT BETWEEN THE HIGH AND LOW PRES OVER THE TROPICS 
WILL BRING AN INCREASE TO NE TRADE WIND FLOW FROM ABOUT 09N TO 
20N AND W OF 120W BY FRI WITH SEAS THERE MAXING OUT TO 8 FT. LOW-
LEVEL CONVERGENCE EXPECTED WITHIN THIS AREA SHOULD LEAD TO AN 
INCREASE OF SHOWER/TSTM ACTIVITY S OF 10N TO NEAR AND ALONG THE 
ITCZ REGION.

A NW SWELL TRAIN WITH SEAS TO 9 FT IS CONFINED TO NW OF LINE 
FROM 30N136W TO 28N140W. THESE SWELLS ARE FORECAST TO REACH NW 
OF A LINE FROM 30N125W TO 23N140W BY EARLY THU BEFORE DECAYING 6-
7 FT ON FRI.

OTHER GAP WINDS...                                               
THE TEHUANTEPEC GAP WIND EVENT...THE HIGH PRES THAT WILL BUILD 
BEHIND THE FRONT CURRENTLY PASSING ACROSS THE WESTERN GULF OF 
MEXICO WILL INITIATE FRESH TO STRONG GAP WINDS THROUGH THE GULF 
OF PAPAGAYO THU NIGHT INTO FRI MORNING...WITH ANOTHER PULSE FRI 
NIGHT INTO SAT MORNING. SIMILARLY...STRONG TRADE WINDS OVER THE 
SW CARIBBEAN SEA WILL PUSH THROUGH PANAMA FRI INTO SAT.

$$
AGUIRRE