000
AXPZ20 KNHC 091525
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                          
1605 UTC TUE APR 9 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
A MONSOON TROUGH EXTENDS FROM 06N77W TO 08N90W...THEN AS ITCZ TO 
07N110W TO 03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION
IS WITHIN 150 NM N OF THE ITCZ AXIS FROM 110W TO 127W.

...DISCUSSION...                                                 
WATER VAPOR IMAGERY SHOWS UPPER LEVEL SPLIT JET STREAM PATTERN W 
OF 125W WITH SOUTHERN BRANCH MERGING WITH POLAR JET ACROSS THE 
BAJA PENINSULA. GFS MODEL GUIDANCE INDICATES AN UPPER TROUGH 
WILL DEEPEN OVER THE INTERMOUNTAIN WEST AND INTENSIFY THE JET AS 
IT ROUNDS THE BASE OF THE TROUGH ACROSS NW MEXICO THROUGH WED 
NIGHT THEN SHIFT RAPIDLY EASTWARD THU. 

STRONG SURFACE HIGH CENTERED NEAR 35N135W EXTENDS A BROAD RIDGE 
ACROSS THE SUBTROPICS W OF 112W. TIGHT PRES GRADIENT ALONG THE 
COAST OF SOUTHERN CALIF...RESULT OF AN INTENSE LOW PRES IN FOUR 
CORNERS REGION PRODUCING GALE FORCE WINDS N OF DISCUSSION AREA 
BETWEEN 118W AND 125W. LARGE SEAS TO 17 FT GENERATED BY THESE 
WINDS ARE SPREADING S OF 30N W OF BAJA CALIFORNIA. DIRECTLY S OF 
THE HIGH...FRESH E-NE TRADE WINDS INDICATED FROM SCATTEROMETER 
FROM 08N TO 18N W OF 128W. GFS AND ECMWF MODELS SHOW SUBTROPICAL 
HIGH MAINTAINING CENTRAL PRES NEAR 1030 MB AND NEARLY STATIONARY 
THROUGH THU. LOW PRES IN THE SOUTHERN ROCKIES MOVES NE INTO THE 
NORTHERN PLAINS...ALLOWING PRES GRADIENT TO RELAX SIGNIFICANTLY 
IN THE REGION. EXPECT WINDS TO DIMINISH BELOW 25 KT ACROSS THE 
ENTIRE BASIN BY WED MORNING...WITH SEA HEIGHTS FROM LARGE N-NW 
SWELL GRADUALLY SUBSIDING AS WELL THROUGH FRI.

$$
MUNDELL