000
AXPZ20 KNHC 041612
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JUN 04 2011

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 
1515 UTC.
 
...ITCZ/MONSOON TROUGH...
MONSOON TROUGH REMAINS ANCHORED ON MONSOONAL GYRE ACROSS THE W 
CARIBBEAN AND EXTENDS W ACROSS SRN COSTA RICA NEAR 09.5N83W TO 
10N86W TO 14N94W TO LOW PRES NEAR 10.5N98W 1009 MB TO 08N102W TO 
11N110W TO LOW PRES NEAR 09N115W 1010 MB TO 05.5N134W WHERE IT 
TRANSITIONS TO ITCZ AND CONTINUES TO 04.5N140W. SCATTERED TO 
LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION N OF 05N E OF 
86W. SCATTERED MODERATE TO STRONG CONVECTION FROM 08.5N TO 11N 
BETWEEN 112W TO 118W. 

...DISCUSSION...
DEEP LAYERED AND UNUSUALLY VIGOROUS CYCLONE OFF CALIFORNIA 
COAST NEAR 36.5N126.5W WITH BROAD MIDDLE TO UPPER LEVEL TROUGH 
EXTENDING S TO 28N129W AND HAS BEGUN TO MERGE WITH A LINGERING 
MID LEVEL TROUGH THAT EXTENDS FROM 29N124W TO 19N126W TO 
10N127W. DOWNSTREAM RIDGE EXTENDS FROM ITCZ NEAR 116W NE TO 
ACROSS CENTRAL MEXICO THEN TO SHARP RIDGE CREST ACROSS SW TEXAS 
NEAR 30N100W. RIDGE IS SQUEEZED BETWEEN PREVIOUS UPPER LEVEL 
TROUGH AND DEEP LAYER TROUGH TO SE EXTENDING FROM A TUTT LOW 
ACROSS THE W GULF OF MEXICO NEAR 23N94W TO WEAK CYCLONIC VORTEX 
AT 13N105W. BROAD ANTICYCLONIC FLOW DOMINATES THE TROPICS TO THE 
E OF THIS TROUGH...ACROSS THE FAR EPAC...NRN S AMERICA AND THE 
CARIBBEAN. 
 
...AT THE LOW LEVELS...
HIGH PRES CENTERED ON 1029 MB HIGH NW OF BASIN NEAR 36N150W HAS 
RIDGE EXTENDING TO 23N114W. DEEP LAYERED LOW OFF CALIFORNIA 
SUPPORTS SURFACE LOW AND COLD FRONT ENTERING AREA FROM 30N127W 
TO 28N134W TO 30N140W. LOW WILL MEANDER NEXT 24 HOURS ALLOWING 
COLD FRONT TO MOVE SE AND WEAKEN NEXT 24 HOURS...AND USHER NW 
SWELL INTO N AND NW PORTIONS OF THE AREA. THIS FRONT HAS 
WEAKENED THE PRES GRADIENT ALONG THE W COAST OF BAJA 
CALIFORNIA...AND S OF THE RIDGE...BUT WILL INCREASE ACROSS BOTH 
AREAS BY SUN MORNING TO PRODUCE WINDS AT 20 KT...WITHIN 120 NM 
OF CENTRAL PORTIONS OF BAJA...AND IN A VERY SMALL AREA N OF THE 
ITCZ W OF 135W. 

THE MONSOONAL GYRE ACROSS THE W CARIBBEAN CONTINUES TO DOMINATE 
THE LLVL FLOW E OF 105W THIS MORNING. A 1009 MB LOW PRESSURE 
CENTER APPEARS TO BE DEVELOPING AT THE SURFACE NEAR 10.5N98W 
ALONG THE MONSOON TROUGH. THIS LOW WILL DRIFT VERY SLOWLY W TO 
NW DURING THE NEXT FEW DAYS AND HAS SOME MODEST POTENTIAL FOR 
SLOW DEVELOPMENT AND IMPROVED ORGANIZATION. THE MONSOON TROUGH 
TO THE E OF THIS LOW REMAINS VERY CLOSE TO THE COASTLINE BEFORE 
CROSSING COSTA RICA INTO THE CARIBBEAN. ABUNDANT TROPICAL 
MOISTURE FEEDING INTO S PORTIONS OF THE MONSOON GYRE IS IGNITING 
INTO DEEP CONVECTION ACROSS THE EPAC E OF 86W...WHICH IN TURN IS 
INDUCING STRONG UPPER DIVERGENCE IN THE ELYS ALOFT.

GAP WINDS...FRESH N BREEZE CONTINUE TO SURGE ACROSS CHIVELA PASS 
AND DOWNSTREAM OF GULF OF TEHUANTEPEC AND WILL CONTINUE THROUGH 
SUN...AIDING LOW PRES ORGANIZATION TO THE SW. 

$$
STRIPLING