000
AXPZ20 KNHC 230310
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT APR 23 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

AXIS IS CENTERED ALONG 6N77W 6N95W 5N106W 5N118W 1N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM N OF THE AXIS 
BETWEEN 117W-121W.

...DISCUSSION...

AT UPPER LEVELS...BROAD RIDGING COVERS MOST OF THE AREA WITH THE
ASSOCIATED UPPER ANTICYCLONE NEAR 15N109W...AND HAS EXPANDED N 
AND NE DURING THE PAST 24 HOURS AND NOW COVERS MOST OF THE AREA 
N OF THE ITCZ BETWEEN 105W AND 135W. THIS RIDGING HAS OCCURRED 
IN LARGE PART DUE TO A SHORTWAVE MOVING EWD THROUGH THE NW 
PORTIONS OF THE AREA AND BROAD TROUGHING ACROSS THE WRN U.S. 
YESTERDAY SHIFTING E INTO TEXAS ALLOWING THE RIDGE TO AMPLIFY 
NWD IN BETWEEN THESE TWO TROUGHS. S TO SW FLOW ALOFT THUS 
PREVAILS FROM 07N TO 25N BETWEEN 125W AND 140W. S OF THE 
ITCZ...A PERSISTENT EQUATORIAL UPPER CYCLONE WAS NOTED NEAR 
1N122W AND WAS BECOMING MORE ELONGATED W TO E. ACTIVE DEEP 
CONVECTION CONTINUES NEAR THE ITCZ BETWEEN THIS UPPER CYCLONE 
AND THE UPPER ANTICYCLONE HELPING TO MAINTAIN DIFFLUENT FLOW 
ALOFT. 

AT LOWER LEVELS...HIGH PRES AND ANTICYCLONIC FLOW DOMINATES MUCH 
OF THE AREA N OF THE ITCZ AND W OF 106W WITH THE ASSOCIATED HIGH 
CENTER OF 1021 MB JUST W OF THE AREA NEAR 25N142W. A RIDGE 
EXTENDS SE FROM THIS HIGH SE TO 18N118W. THE PRES GRADIENT 
BETWEEN THE RIDGE AND A TROUGH OF LOW PRESSURE OVER MEXICO IS 
SUPPORTING NW WINDS OF 20 KT N OF 24N E OF 119W TO THE W COAST 
OF BAJA CALIFORNIA. AN ASCAT PASS FROM 1750 UTC THU AFTERNOON
PARTIALLY CAPTURED THESE WINDS. THE PRES GRADIENT BETWEEN THE 
RIDGE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS 
SUPPORTING NE TO E 20 KT TRADES FROM 6N TO 17N W 0F 132W...AND 
ALSO FROM 8N TO 15N BETWEEN 125W-132W. THE HIGH WILL REORGANIZE 
OVER THE NEXT 18-24 HOURS AS A SHORTWAVE AND ITS ASSOCIATED COLD 
FRONT SWEEP EWD AND OVER THE RIDGE. THIS WILL SHIFT THE FRESH 
TRADEWINDS SLIGHTLY WWD BEFORE REBUILDING SAT NIGHT AND SUN. 
FRESH NWLY WINDS OFF OF BAJA WILL DIMINISH IN AREAL COVERAGE 
DURING THE NEXT 48 HOURS.

A PLUME OF ABUNDANT TROPICAL MOISTURE CONTINUES TO SPREAD FRO 
THE ITCZ NEAR 100W...NE INTO EXTREME SE MEXICO AND GUATEMALA 
THIS MORNING. CONVECTION SHOULD ONCE AGAIN BECOME ACTIVE OVER
FAR SE MEXICO AND GUATEMALA ON SATURDAY WITH DAYTIME HEATING.

$$
AGUIRRE