000
AXPZ20 KNHC 190922
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE APR 19 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ALONG 05N77W TO 
07N92W THEN RESUMES NEAR 06N95W TO 04N112W TO 04N128W THEN 
RESUMES NEAR 03N131W TO 04N140W. SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION WAS FROM 03N TO 07N BETWEEN 89W AND 95W.  

...DISCUSSION...

ALOFT...A MID TO UPPER LEVEL TROUGH REACHES FROM 27N134W TO 
20N140W. MID TO UPPER LEVEL MOISTURE IS BEING ADVECTED NE FROM 
THE TROPICS WITHIN 360 NM E OF THE TROUGH BY A 40-55 KT JET. 
UPPER RIDGING IS TO THE E EXTENDING FROM 32N130W S TO 20N130W. 
ANOTHER MID TO UPPER LEVEL TROUGH IS E OF THIS RIDGING REACHING 
FROM WESTERN TEXAS ACROSS NW MEXICO AND THE CENTRAL BAJA 
CALIFORNIA PENINSULA TO 24N120W. A THIN BAND OF MID TO UPPER 
LEVEL MOISTURE IS MOVING OUT AHEAD OF THIS TROUGH ACROSS N 
CENTRAL MEXICO. UPPER RIDGING DOMINATES THE MAJORITY OF THE 
WATERS S OF 20N CENTERED OVER AND ALONG 10N. ONLY SPORADIC
CLUSTERS OF CONVECTION ARE OCCURRING ON THE S SIDE OF THIS 
RIDGING ALONG THE ITCZ.

AT THE SURFACE...1021 MB HIGH PRES IS CENTERED NEAR 29N134W WITH 
A RIDGE AXIS EXTENDING SE TO NEAR 20N113W. A SURFACE TROUGH IS 
NE OF THIS RIDGING EXTENDING FROM SW ARIZONA ACROSS THE NORTHERN 
GULF OF CALIFORNIA TO 28N114W. A 0444 UTC ASCAT PASS INDICATED 
THAT THE PRES GRADIENT W OF THE N BAJA CALIFORNIA PENINSULA HAS 
RELAXED ALLOWING FROM NW-N WINDS TO DIMINISH TO LESS THAN 20 KT. 
GFS...SREF AND NAM MODEL GUIDANCE ALL SUPPORT A RETURN OF 20 KT 
NW-N WINDS WITHIN 120 NM W OF THE N BAJA CALIFORNIA PENINSULA 
COMMENCING WED NIGHT. 

THE REMAINDER OF THE DISCUSSION AREA IS VOID OF 20 KT OR GREATER 
WINDS AT THIS TIME...HOWEVER MODEL GUIDANCE INDICATES A SMALL 
AREA OF 20 KT TRADES FORMING IN THE FAR W CENTRAL PORTION N OF 
THE ITCZ WED AFTERNOON. OTHERWISE...SEAS WILL BUILD TO 8 FT IN 
THE AREA S OF 03N BETWEEN 108W AND 124W WED AFTERNOON THROUGH 
NIGHT.

THESE SEAS ARE ASSOCIATED WITH VERY LONG PERIOD 19-21 SECOND 
CROSS-EQUATORIAL SW SWELL WHICH WILL SWEEP NE ACROSS THE WATERS 
TODAY THROUGH THE REMAINDER OF THE WEEK...REACHING THE COASTAL 
AREAS OF SOUTHERN CALIFORNIA...MEXICO AND CENTRAL AMERICA THU. 
WHILE SEA HEIGHTS WILL BE LESS THAN 8 FT AS THE SWELL PROPAGATES 
AWAY FROM THE EQUATOR...THIS HIGH ENERGY SWELL WILL STILL RESULT 
IN VERY HAZARDOUS SURF CONDITIONS AT COASTAL LOCATIONS INCLUDING 
AN ENHANCED RIP CURRENT DANGER THU THROUGH THE WEEKEND.

$$
LEWITSKY