000
AXPZ20 KNHC 182208
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC SUN JAN 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC. 

...SPECIAL FEATURES...
                                       
GULF OF TEHUANTEPEC GALE WARNING...HIGH PRESSURE BUILDING SOUTH 
FROM TEXAS INTO CENTRAL MEXICO HAS BEGUN TO TIGHTEN THE PRES 
GRADIENT ACROSS SOUTHERN MEXICO AND FUNNEL WINDS FROM THE GULF 
OF MEXICO THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. 
RECENT 1600 UTC ASCAT DATA INDICATES THAT WINDS HAVE INCREASED 
TO MINIMAL GALE FORCE ACROSS TEHUANTEPEC...AND ARE EXPECTED TO 
INCREASE TO 40 KT BY THIS EVENING...THE GRADUALLY WEAKEN BELOW 
GALE FORCE MONDAY MORNING. DOWNSTREAM SEAS WILL BUILD TO 10-15 
FT OVERNIGHT. WINDS AND SEAS WILL RAPIDLY DIMINISH MON NIGHT AND 
TUE MORNING AS THE PRESSURE GRADIENT WEAKENS ACROSS THE REGION.  
GALE FORCE WINDS ARE NOT EXPECTED BY GLOBAL MODELS AGAIN IN THE 
REGION UNTIL FRI NIGHT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...  
         
THE MONSOON TROUGH EXTENDS FROM 07N74W TO 02.5N81W TO 08N85.5W  
TO 07N94W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 
11N111W...WHERE IT BREAKS...THEN RESUMES FROM 08N116W TO 10N126W 
TO BEYOND 07N140W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO 
STRONG N OF ITCZ TO 16N BETWEEN 106W AND 111W.

...DISCUSSION...  
                                               
THE REMNANTS OF A LOW PRES CENTER CONTINUE TO MOVE WESTWARD 
ACROSS THE AREA TODAY...IN THE FORM OF A TROUGH EXTENDING FROM 
20N125.5W TO 14N127W. THE PRESSURE GRADIENT BETWEEN THE TROUGH 
AND A WEAKENING RIDGE TO THE NORTH CONTINUE TO PRODUCE A ZONE OF 
STRONG NE WINDS DRAPED ACROSS N AND NW PORTIONS OF THE TROUGH... 
FROM 19N TO 4.5N BETWEEN 123W AND 129W...WHERE SEAS ARE RUNNING 
9 TO 11 FT. THIS TROUGH HAS MOVED INTO THE DRY AND STABLE AIR 
OCCURRING ACROSS THE W PERIPHERY OF A BROAD MIDDLE TO UPPER LEVEL 
TROUGH PERSISTING ACROSS CENTRAL PORTIONS FOR THE PAST FEW DAYS. 
THIS TROUGH EXTENDED N OF 08N AND SPANNED THE AREA BETWEEN 110W 
AND 130W. AN EMBEDDED DEEP LAYERED CYCLONE WAS CENTERED NEAR 
13N122W...WITH TROUGHING EXTENDING FROM THIS CYCLONE TO 10N110W. 
ABUNDANT LOW LEVEL MOISTURE CONVERGING E OF THE CYCLONE AND N OF 
THE ITCZ WAS PRODUCING AN AREA OF SCATTERED TO LOCALLY NUMEROUS 
MODERATE TO STRONG CONVECTION ACROSS THIS AREA DESCRIBED ABOVE. 
THE UPPER CYCLONE WILL SHIFT SLOWLY E AND NE AND WEAKEN OVER THE 
NEXT FEW DAYS...AND ACTIVE CONVECTION ACROSS THIS AREA WILL 
GRADUALLY DIMINISH. 

GULF OF PAPAGAYO...STRONG RIDGE ACROSS CENTRAL AMERICA SUPPORTS 
FRESH TO STRONG DIURNAL NE WINDS PULSING THROUGH PAPAGAYO. PEAK 
WINDS WILL CONTINUE TO BE IN EXCESS OF 25 KT DURING LATE NIGHT 
AND EARLY MORNING HOURS THROUGH TUE...BRIEFLY REACHING 30 KT 
DURING MAXIMUM NOCTURNAL DRAINAGE FLOW BEFORE SUNRISE...WITH A 
LULL EACH DAY DURING THE AFTERNOON WITH WINDS LESS THAN 20 KT. 
SEAS WILL REACH 8-9 FT DOWNWIND OF THE GULF MON MORNING. LOCAL 
EFFECTS ARE EXPECTED TO BE WEAKER TUE MORNING...WITH SEAS LESS 
THAN 8 FT.

GULF OF PANAMA...FRESH TO OCCASIONALLY N WINDS WILL PERSIST IN 
THE GULF OF PANAMA THROUGH MON NIGHT DUE TO A PRESSURE GRADIENT 
ACROSS THE AREA. MAX SEAS TO 7 FT EXPECTED AT PEAK WINDS DURING 
THE MORNING. LOCAL EFFECTS WILL BE WEAKER TUE MORNING...WITH 
WINDS 20 KT OR LESS AND SEAS LESS THAN 8 FT.
 
$$ 
STRIPLING