000
AXPZ20 KNHC 082152
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI FEB 08 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 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 04N77W TO 04N85W TO 02N93W TO 09N108W THEN 
ITCZ TO 10N112W TO 05N128W TO BEYOND 07N140W.  ISOLATED MODERATE 
CONVECTION WITHIN 120 NM OF TROUGH FROM 84W TO 88W.

...DISCUSSION...
UPPER LEVEL LONGWAVE TROUGH WELL N OF BASIN FLATTENS CREST OF 
RIDGE CENTERED IN ANTICYCLONE AT 08N132W.  MOSTLY ZONAL FLOW 
ALOFT N OF 15N W OF 112W.  SOME MOISTURE ADVECTED BY 75 KT JET 
CORE IS EXPECTED TO EVAPORATE IN AN OTHERWISE VERY DRY AND 
STABLE UPPER LEVEL ENVIRONMENT.  SHARP UPPER LEVEL TROUGH FROM 
SOUTHERN MEXICO TO 00N108W EXTEND DRY AIR MASS E TO 90W.  ONLY 
MINOR AMOUNTS OF TROPICAL MOISTURE AVAILABLE FOR MONSOON TROUGH 
AND ITCZ WITH ONLY ISOLATED MODERATE CONVECTION NOTED.

...AT THE LOWER LEVELS...
HIGH PRES CENTER 1035 MB N OF AREA AT 37N138W HAS RIDGE EXTEND 
TO 16N113W SUPPORTING MODERATE TO FRESH TRADE WINDS WITH SEAS 9 
TO 10 FT FROM 10N TO  20N W OF 132W THROUGH SAT.  STRENGTHENING 
RIDGE MOVES NE SAT ALLOWING TRADES TO DIMINISH TO A MODERATE 
BREEZE WITH NW SWELLS 8-9 FT LINGERING BEYOND FORECAST PERIOD.  
PRES GRADIENT FROM RIDGE AGAINST SURFACE LOW PRES CENTER 1001 MB 
OVER NEVADA PROMPTS FRESH TO STRONG BREEZE ALONG CALIFORNIA 
COAST SPILLING S OF 30N INTO NORTHERN BAJA PENINSULA WATERS.  
SIMILARLY WINDS DIMINISH ALONG LATE SAT AS HIGH PRES CENTER 
MOVES NE.    

GAP WINDS...
GULF OF TEHUANTEPEC...COLD FRONT OVER GULF OF MEXICO MOVING E 
EARLY TONIGHT FUNNELS N WINDS ACROSS CHIVELAS PASS INTO GULF OF 
TEHUANTEPEC LATE TONIGHT.  WINDS QUICKLY TURN SOUTHEASTERLY IN 
SW GULF OF MEXICO LATE SAT...CUTTING OFF FUNNELING EVENT AND 
DIMINISHING WINDS ACROSS GULF OF TEHUANTEPEC BY LATE SUN.

GULF OF PAPAGAYO...INCREASING CARIBBEAN TRADES SEEP THROUGH 
MOUNTAINS PASSES IN NICARAGUA INTO GULF OF PAPAGAYO WITH WINDS 
INCREASING TO A FRESH BREEZE LATE TONIGHT.  WINDS DIMINISH 
DURING DAYTIME HOURS BUT STRENGTHEN AT NIGHT AS COOL DOWNSLOPE 
DRAINAGE MOUNTAIN AIR ENHANCE EASTERLIES MAKING THIS PULSATING 
EFFECT THROUGH BEYOND SUN.

$$
WALLY BARNES