000
AXPZ20 KNHC 021503
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC THU APR 02 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1300 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
          
THE ITCZ AXIS WAS ANALYZED FROM 08N87W TO 03N103W TO 04N120W TO 
03N126W. ISOLATED MODERATE CONVECTION WAS WITHIN 90 NM N OF 
THE AXIS BETWEEN 91W AND 110W. 
 
...DISCUSSION... 
  
A 1035 MB SUBTROPICAL HIGH WAS ANALYZED NEAR 40N138W. A RIDGE 
EXTENDS FROM THE HIGH THROUGH 32N138W TO 16N103W. THE PRESSURE 
GRADIENT BETWEEN THE RIDGE AND TROUGHING OVER THE INTERIOR 
WESTERN U.S. IS SUPPORTING AN AREA OF GALE FORCE WINDS OFF THE 
CALIFORNIA COAST N OF THE AREA. SCATTEROMETER DATA SHOWS 20-25 
KT WINDS FROM 28N-32N BETWEEN 120W-128W. ALTIMETER AND BUOY DATA 
SHOWS SEAS TO 13 FT IN THIS AREA. THESE WINDS WILL PERSIST INTO 
FRI BEFORE DIMINISHING AS THE RIDGE AXIS SHIFTS SLIGHTLY TO THE 
W...WEAKENING THE PRESSURE GRADIENT. A LARGE AREA OF NW SWELL 
WITH 8 TO 10 FT SEAS BLANKETS THE AREA N OF A LINE FROM 26N115W 
TO 08N140W. SCATTEROMETER DATA SHOW FRESH TO STRONG E-NE TRADE 
WINDS LIE ON THE SW SIDE OF THE RIDGE AXIS FROM 22N-29N W OF 
133W. THIS AREA OF TRADES SHOULD SHIFT S AROUND 3-5 DEGREES FRI 
IN RESPONSE TO THE CHANGES IN THE RIDGE LOCATION. THE TRADES 
WILL DIMINISH TO A FRESH BREEZE BY SAT AS THE SUBTROPICAL HIGH 
WEAKENS.

A WEAK UPPER TROUGH LIES FROM 21N122W TO 00N115W. A 45-KT 
SOUTHWESTERLY JET LIES ON THE NE SIDE OF THIS TROUGH. MID TO 
UPPER LEVEL MOISTURE IS BEING TRANSPORTED TOWARD BAJA CALIFORNIA 
SUR BY THIS JET. MULTI-LEVEL CLOUDS WITH SOME EMBEDDED SHOWERS 
LIE WITHIN 240 NM EITHER SIDE OF A LINE FROM 13N122W TO 23N115W 
TO MAZATLAN AND CIRRUS EXTENDS INLAND WITHIN 120 NM EITHER SIDE 
OF A LINE FROM MAZATLAN TO MATAMOROS. THIS TROUGH WILL BE 
OVERTAKEN BY A NORTHERN STREAM TROUGH CURRENTLY MOVING INTO NW 
WATERS. AN 80-KT UPPER JET ON THE E SIDE OF THIS TROUGH IS ALSO 
TRANSPORTING UPPER TO MID LEVEL MOISTURE NORTHEASTWARD. A LINE 
OF MULTI-LEVEL CLOUDS AND POSSIBLE A ISOLATED SHOWERS CAN BE 
FOUND WITHIN 90 NM EITHER SIDE OF A LINE FROM 32N123W TO 
18N136W. THIS TROUGH WILL GRADUALLY MOVE EASTWARD OVER N WATERS 
THROUGH THE END OF THE FORECAST PERIOD SAT MORNING.

GAP WINDS...                                                     
GULF OF PAPAGAYO...THE PRESSURE GRADIENT BETWEEN A PERSISTENT E-
W RIDGE ACROSS THE GULF OF MEXICO AND THE ITCZ TO THE SW IS 
SUPPORTING A MODERATE TO FRESH E-NE BREEZE. THIS BREEZE IS BEING 
ENHANCED BY NOCTURNAL DRAINAGE FLOW OFF THE MOUNTAINS...ALLOWING 
FOR WINDS TO REACH THE ADVISORY CRITERIA OF 20-25 KT IN THE LATE 
NIGHT AND EARLY MORNING HOURS. A FRESH TO STRONG E-NE WINDS 
DOWNWIND OF THE GULF OF PAPAGAYO TO 88W WILL DIMINISH LATER THIS 
MORNING. WEAK PULSES OF WINDS TO A FRESH TO STRONG BREEZE WILL 
RETURN OVERNIGHT TONIGHT AND TOMORROW NIGHT. 

GULF OF TEHUANTEPEC...A SURFACE TROUGH BUILDING OVER THE BAY OF 
CAMPECHE ON SAT MORNING WILL DIRECT NORTHERLY FLOW THROUGH 
CHIVELA PASS. THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW WILL 
ALLOW WINDS TO INCREASE TO A FRESH TO STRONG BREEZE IN THE GULF 
OF TEHUANTEPEC SAT MORNING.

$$ 
SCHAUER