000
AXPZ20 KNHC 110337
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON FEB 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 00N80W TO 05N94W TO 04N99W THEN ITCZ TO 1010 
MB LOW PRES AT 04N107W TO 08N117W TO 06N125W TO 04N140W.  
ISOLATED MODERATE CONVECTION WITHIN 150 NM OF AXIS FROM 85W TO 
96W.

...DISCUSSION...
PREVIOUSLY FLAT-CREST RIDGE NOW ABLE TO BUILD N AS LONGWAVE 
TROUGH PULLS EASTWARD.  MODEL GUIDANCE INDICATES RIDGE IS STRONG 
ENOUGH TO BLOCK APPROACHING DEEP LAYER CYCLONE DEVELOPING FROM 
VIGOROUS SHORT WAVE JUST W OF BASIN.  CYCLONE PLUNGES S ROUNDING 
BASE OF UPSTREAM LONGWAVE UPPER LEVEL TROUGH AND APPROACHES NW 
CORNER WITH ATTENDANT SURFACE LOW PRES AND COLD FRONT.  IF 
GUIDANCE SOLUTIONS ARE CORRECT...COLD FRONT SHOULD STALL JUST W 
OF 140W WITH ASSOCIATED GALE FORCE WINDS JUST W OF E PAC BASIN.  
GFS AND CANADIAN SOLUTIONS THE MOST AGGRESSIVE WHILE UKMET AND 
ECMWF LESS SO...BUT INCH COLD FRONT CLOSER TO 140W.  EITHER WAY 
WIND AND SEAS CONDITIONS LIKELY TO DETERIORATE BY END OF PERIOD 
IN WESTERN FRINGES OF BASIN.  LOW PRES CENTER LIKELY TO TIGHTEN 
GRADIENT ENOUGH TO INCREASE TRADES AND SEAS W OF 120W.

SECOND DEEP LAYER CYCLONE SUPPORTS WEAK LOW PRES CENTER 1010 MB 
AT 04N107W ALONG ITCZ...BUT SURROUNDING AIR MASS REMAINS VERY 
DRY WITH ISOLATED MODERATE CONVECTION NOTED WITHIN 150 NM OF 
MONSOON TROUGH FROM 85W TO 96W.  MID TO UPPER LEVEL ANTICYCLONE 
OVER PANAMA SUPPLIES MINOR AMOUNT OF TROPICAL MOISTURE TO PROMPT 
CONVECTION. 

...ELSEWHERE AT THE LOWER LEVELS...
HIGH PRES CENTER 1034 MB N OF BASIN MOVED FURTHER NE AND ALLOWED 
TRADES TO DIMINISH TO A MODERATE BREEZE W OF 120W.  SWELLS FROM 
PREVIOUS GALE EVENT N OF AREA REMAIN 10-13 FT N OF 23N AND 8-11 
FT S OF 20N W OF 106W.  TRADES EXPECTED TO INCREASE TO A STRONG 
BREEZE AGAIN...OR EVEN NEAR GALE FORCE CLOSE TO 140W...AS PRES 
GRADIENT WITH APPROACHING LOW PRES CENTER W OF BASIN INCREASE.  
LONG NE FETCH MAY BUILD SEAS HIGHER THAN THE 11-13 FT NWW3 
SOLUTION INDICATES.

E PAC SURFACE RIDGE MOVING INLAND CALIFORNIA LATE TUE TIGHTENS 
PRES GRADIENT WITH STATIONARY SURFACE TROUGH ALONG CENTRAL 
MEXICO AND PROMPT STRONG NW WINDS ALONG GULF OF CALIFORNIA WITH 
TRAPPED SEA HEIGHTS REACHING 8 FT BY LATE WED.

GAP WINDS...
STRONG E WINDS OVER SW CARIBBEAN SUPPORT FRESH TO STRONG BREEZE 
ACROSS NICARAGUA INTO GULF OF PAPAGAYO.  STRONGER WINDS PULSE 
DURING OVERNIGHT AND EARLY MORNING HOURS WHEN DRAINAGE IS STRONG 
...THEN DIMINISH DURING LATE MORNING INTO EARLY EVENING.  SEAS 
BRIEFLY BUILD AS MUCH AS 8 FT DURING STRONGER WINDS. 


$$
WALLY BARNES