000
AXPZ20 KNHC 191545
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE APR 19 2011

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N78W TO 
06N94W TO 04N99W TO 06N110W TO 03N122W TO 04N132W TO 03N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 04N TO 07N 
BETWEEN 85W AND 92W. SCATTERED MODERATE CONVECTION WITHIN 60 NM 
OF AXIS BETWEEN 118W AND 113W. ALSO SCATTERED MODERATE TO STRONG 
CONVECTION N OF THE ITCZ WITHIN 30 NM OF LINE 15N93W TO 08N113W.


...DISCUSSION...

NEARLY STATIONARY 1022 MB HIGH PRES NEAR 27N135W AND ASSOCIATED 
RIDGE EXTENDING TO NEAR 18N110W DOMINATES THE NW PORTION OF THE 
FORECAST AREA. LIGHT TO MODERATE WINDS AND SUBSIDING SEAS PREVAIL
OVER A BROAD AREA N OF 17N AND W OF 118W. SCATTEROMETER DATA FROM
12 HOURS AGO SHOWED AN AREA OF MODERATE 15-20 KT TRADE WINDS SSE 
OF THE HIGH FROM 06N TO 16N W OF 120W. MODEL GUIDANCE INDICATES 
THIS TREND WILL CONTINUE ACROSS THE ENTIRE EASTERN PACIFIC FOR 
ANOTHER 24-36 HOURS BEFORE PRES GRADIENTS TIGHTEN AGAIN NEAR BAJA
CALIFORNIA AND S OF RIDGE AXIS IN A TYPICAL TRADE WIND REGIME. 

A PAIR OF WEAK COLD FRONTS WILL CLIP THE EXTREME NW PART OF THE 
DISCUSSION AREA WITH LITTLE EFFECT OTHER THAN A SHIFT IN WIND DIR
AND SLIGHTLY HIGHER NW SWELL BEHIND THE FRONTS. THE FIRST FRONT 
WILL PASS CLOSE TO 30N140W LATER TODAY...AS A DISSIPATING FRONT 
EXTENDING S FROM A 1010 MB LOW CURRENTLY NEAR 37N142W...AND THE 
NEXT FRONT BRUSHING PAST THE NORTHERN BOUNDARY FRI AND FRI NIGHT.
HIGH PRES BUILDING N OF THE AREA BEHIND FIRST FRONT WILL MAINTAIN
WEAK STATIONARY FRONTAL BOUNDARY N OF 29N W OF 130W THROUGH WED.

WEAK CYCLONIC CIRCULATION IS EVIDENT FROM ANIMATED VIS SATELLITE 
IMAGERY IS LOCATED NEAR 06N93W. GFS AND EUROPEAN MODEL FORECASTS 
SHOW WEAK LOW LEVEL TROUGH ASSOCIATED WITH ITCZ CONVECTION IN THE
AREA S OF CENTRAL AMERICA CONTINUING THROUGH THU-FRI BUT THERE IS
NO EVIDENCE OF POTENTIAL FOR ANY OF THE WEAK VORTICES EMBEDDED IN
THE ITCZ TO DEVELOP BEYOND 10-20 KT WINDS NEAR THE CIRC CENTER.

VERY LONG PERIOD 19-20 SEC CROSS-EQUATORIAL SW SWELL WILL SWEEP 
NE ACROSS THE WATERS THE REMAINDER OF THE WEEK...REACHING 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 SAT.

$$
MUNDELL