000
AXPZ20 KNHC 142207
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU FEB 14 2013

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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 08N82W TO LOW PRES NEAR 
06N96.5W 1011 MB TO 07N113W...WHERE IT TRANSITIONS TO 
ITCZ...CONTINUING ON TO 05N127W TO 06N132W TO 06N140W. ISOLATED 
TO SCATTERED MODERATE TO STRONG NOTED WITHIN 120 NM S OF TROUGH 
BETWEEN 82W AND 88W. SCATTERED MODERATE TO STRONG NOTED WITHIN 
300 NM N OF ITCZ AXIS BETWEEN 124W AND 136W.

...DISCUSSION...
A MID TO UPPER CYCLONE JUST W OF THE AREA THE PAST FEW DAYS HAS 
FINALLY FILLED WITHIN AN UPPER TROUGH...EXTENDING FROM 34N136W 
TO 14N140W. A SHARPLY NEGATIVELY TILTED UPPER TROUGH EXTENDS 
FROM THIS PORTION SE TO THE EQUATOR ALONG 120W...WITH UPPER 
DIVERGENCE JUST E OF THIS TROUGH AIDING IN MAINTAINING SCATTERED 
MODERATE TO STRONG CONVECTION OCCURRING WITHIN A ZONE OF STRONG 
TRADEWINDS FROM 07N TO 16N W OF 125W. A SECOND UPPER TROUGH IS 
SINKING S INTO THE NORTHERN PORTION OF THE AREA...ROUGHLY ALONG 
33N BETWEEN 120W AND 130W. A LONGWAVE UPPER TROUGH DOMINATING N 
AMERICA HAS ITS MEAN AXIS EXTENDING S ACROSS TEXAS AND E 
PORTIONS OF OLD MEXICO FROM 32N100W TO 22N100W. TO THE S...AND 
SEPARATING THESE UPPER TROUGHS...IS UPPER RIDGE EXTENDING N FROM 
AN UPPER ANTICYCLONE AT 13N115W TO A CREST AT 31N120W. ANOTHER 
UPPER ANTICYCLONE IS OVER THE TROPICS AT 13N96W WITH A TROPICAL 
RIDGE EXTENDING W TO PREVIOUS ANTICYLONE...AND NE ACROSS MOST OF 
THE CARIBBEAN. 

AT THE LOW LEVELS...A RIDGE EXTENDS FROM 1037 MB HIGH ACROSS THE 
NE PACIFIC THROUGH 32N131W TO 14N108W. NE TRADES ARE ENHANCED TO 
20 TO 25 KT S OF THE RIDGE FROM 07N TO 16N W OF 125W...WITH A 
RECENT 1854 UTC ASCAT PASS DEPICTING NE WINDS 25-30 KT FROM 07N 
TO 10N BETWEEN 131W AND 138W...WHERE ALTIMETER PASSES VERIFY 
SEAS OF 9 TO 13 FT IN MIXING NE AND NW SWELL. THIS ENHANCED AREA 
OF TRADES WILL SHRINK OVER THE NEXT COUPLE OF DAYS. NORTHERLY 
FLOW E OF THE SURFACE RIDGE HAS DIMINISHED THROUGH THE GULF OF 
CALIFORNIA BUT WILL RETURN THIS EVENING TO 20 TO 25 KT THROUGH 
MIDDLE PORTIONS OF THE GULF AND GRADUALLY SHIFT INTO N PORTIONS 
THROUGH SAT.      

GAP WINDS...
GULF OF TEHUANTEPEC...NORTHERLY WINDS BEHIND A COLD FRONT MOVING 
THROUGH THE SW GULF OF MEXICO TODAY WILL SQUEEZE THROUGH THE 
CHIVELA PASS AND BEGIN TO GENERATE PULSES OF FRESH TO STRONG N 
WINDS IN THE GULF OF TEHUANTEPEC FROM AROUND SUNRISE FRI MORNING 
THROUGH SAT EVENING. HIGH PRESSURE BUILDING ACROSS THE GULF OF 
MEXICO FRI NIGHT WILL STRENGTHEN THE GAP WINDS THROUGH 
TEHUANTEPEC...WITH A MINIMAL GALE EXPECTED BY SUNRISE 
SAT...STRENGTHENING TO A STRONG GALE SAT NIGHT...POSSIBLY 
REACHING STORM STRENGTH...AND CONTINUING THROUGH SUNRISE ON SUN. 

$$
STRIPLING