000
AXPZ20 KNHC 170313
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC TUE FEB 17 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...STRONG HIGH PRESSURE WILL 
BUILD NORTH OF THE REGION BEHIND A COLD FRONT MOVING ACROSS THE 
GULF OF MEXICO TUESDAY. THE TIGHT PRESSURE GRADIENT ALONG WITH A 
PUSH OF DENSE DRY AND COOL AIR THROUGH THE CHIVELA PASS IN 
SOUTHERN MEXICO WILL RESULT IN WINDS TO GALE FORCE OVER THE GULF 
OF TEHUANTEPEC BY TUESDAY NIGHT. SEAS WILL BUILD DOWNSTREAM OF 
THE GULF OF TEHUANTEPEC...REACHING AS HIGH AS 16 FT BY LATE WED. 
THE GALES WILL PERSIST THROUGH LATE THURSDAY...THEN DIMINISH AS 
THE HIGH PRESSURE NORTH OF THE AREA WEAKENS AND SHIFTS EAST.
                   
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
            
THE MONSOON TROUGH FROM EXTENDS FROM 09N85W TO 04N90W TO 
04N100W...WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ CONTINUES 
WESTWARD FROM 04N135W TO BEYOND 06N140W. SCATTERED MODERATE 
CONVECTION WITHIN 210 NM N OF AXIS FROM 122W TO 130W.

...DISCUSSION... 
 
THE GULFS OF PAPAGAYO AND PANAMA...THE STRONG HIGH PRESSURE 
NORTH OF THE AREA IS WEAKENING AND SHIFTING EAST AHEAD OF A COLD 
FRONT MOVING INTO THE NORTHEAST GULF OF MEXICO. THIS IS 
RESULTING IN A WEAKENING PRESSURE GRADIENT ACROSS THE SOUTHWEST 
CARIBBEAN. THIS IN TURN IS ALLOWING THE GAP WIND PULSES THROUGH 
THE GULFS OF PAPAGAYO AND PANAMA THAT HAVE BEEN PERSISTENTLY 
STRONG OVER THE PAST SEVERAL DAYS TO DIMINISH. ONE MORE BRIEF 
PULSE OF 20 TO 25 KT WINDS IS EXPECTED IN BOTH AREAS LATE THIS 
EVENING AND OVERNIGHT...BUT WILL QUICKLY DIMINISH THROUGH THE 
MORNING. LIGHT TO MODERATE WINDS CAN BE EXPECTED OVER THE NEXT 
COUPLE OF DAYS...WITH MODEST INCREASES OVERNIGHT DUE TO DRAINAGE 
EFFECTS. THE NEXT STRONG GAP EVENT IN THE GULF OF PAPAGAYO WILL 
COMMENCE LATE WEDNESDAY NIGHT AS THE NEXT HIGH PRESSURE AREA 
BUILDS OVER THE GULF.
 
1019 MB HIGH PRESSURE IS CENTERED NEAR 28N126W...BLOCKING THE 
ADVANCE OF A COLD FRONT FARTHER WEST THAT IS REACHING FROM 
35N135W TO 20N140W. A NEGATIVELY TILTED MID/UPPER LEVEL 
SUPPORTING THE COLD FRONT IS PIVOTING ACROSS THE NORTHWEST OF 
THE DISCUSSION AREA. INSTABILITY ASSOCIATED WITH THE MID/UPPER 
TROUGH IS ENHANCING AREAS OF THUNDERSTORMS WITHIN 60 NM E OF THE 
FRONT FROM 22N TO 25N.

GLOBAL MODELS ARE IN GOOD AGREEMENT INDICATING THE TROUGH WILL 
STALL AND BECOME CUTOFF NEAR 26N132W BY EARLY WEDNESDAY. THIS 
WILL ALLOW THE FRONT TO STALL AND DISSIPATE OVER THE NEXT 
COUPLE OF DAYS FROM 30N133W TO 20N140W. 

SHIP OBSERVATIONS AND EARLIER SCATTEROMETER SATELLITE DATA 
INDICATED GENERALLY MODERATE SOUTHERLY FLOW AHEAD OF THE 
FRONT...WITH 15 TO 20 KT NORTHWEST WINDS FOLLOWING THE FRONT. 
ALTIMETER SATELLITE DATA INDICATED SEAS TO 14 BEHIND THE FRONT 
HOWEVER...LIKELY IN NW SWELL. THIS LONGER PERIOD NW SWELL WILL 
FOLLOW THE FRONT. THIS SWELL WILL GRADUALLY DECAY BELOW 8 FT 
OVER THE NEXT 2 TO 3 DAYS.

$$
CHRISTENSEN