000
AXPZ20 KNHC 192210
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU MAY 19 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.
 
...ITCZ...
AXIS ALONG 12N86W TO 12N93W TO 06N116W TO 05N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 90 NM N AND 180 
NM S OF AXIS BETWEEN 97W AND 110W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION NOTED WITHIN 90 NM OF AXIS FROM 114W TO 137W.

...DISCUSSION...
UPPER LEVEL TROUGH EXTENDS SW FROM 32N138W TO WELL DEFINED 
CYCLONIC VORTEX AT 24N137W...WITH ATTENDANT TROUGH EXTENDING S 
TO 05N142W. BROAD ANTICYCLONIC GYRE DOWNSTREAM EFFECTIVELY 
COVERS REMAINDER OF BASIN WITH E-W RIDGE ALONG 08-11N E OF 
130W.  RIDGE CREST FLATTENED BY ANOTHER CYCLONE OVER FOUR 
CORNERS AREA IN SW CONUS. TROUGHING ALONG 140W COMBINING WITH W 
PORTION OF RIDGE TO ADVECT ABUNDANT TROPICAL MOISTURE FROM ITCZ 
N AND NE. HADLEY CELL WELL ESTABLISHED ACROSS THE TROPICAL EPAC 
AS PERSISTENT RISING MOTION PREVAILS UNDERNEATH UPPER RIDGE...AS 
INDICATED BY PERSISTENT DEEP CONVECTION...WHILE SINKING MOTION 
AND SUBSIDENCE CONTINUE 15-20 DEGREES TO THE N AND S IN BOTH 
HEMISPHERES. 

AT LOW LEVELS...WEAK COLD FRONTAL BOUNDARY HAS DISSIPATED AS IT 
MOVED ACROSS NRN BAJA CALIFORNIA LAST NIGHT. OTHERWISE...HIGH 
PRES RIDGE DOMINATES THE NW TWO-THIRDS OF THE AREA...CENTERED ON 
A 1024 MB HIGH NEAR 35N132W EXTENDING SE TO NEAR 17N110W. 
MODERATE TO FRESH NW BREEZE CONTINUES WITHIN 300 NM OF BAJA 
CALIFORNIA W COAST AND WILL DIMINISH NEXT 48 HOURS AS RIDGE 
BREAK DOWN THROUGH SAT. SUBSIDING CROSS-EQUATORIAL S-SW SWELLS 
STILL LINGER ACROSS MOST OF EPAC BASIN THROUGH FRI NIGHT AND BE 
REINFORCED BY ANOTHER PULSE OF MODERATE SW SWELL SAT AND SUN. 

E OF 110W...MONSOONAL LLVL FLOW PREVAILS...WITH S TO SW FLOW S 
OF THE ITCZ E OF 125W DEPICTED BY RECENT SCATTEROMETER PASSES. 
STRONGEST WINDS SUGGESTED AT 15 TO NEAR 20 KT FROM 02N TO ITCZ 
BETWEEN 93W AND 118W...ACTING AS ENHANCED INFLOW INTO DEEP 
CONVECTION PULSING THERE. GLOBAL MODELS SUGGESTING CHANCE FOR 
CONTINUED DEEP CONVECTION ALONG ITCZ BETWEEN 103W AND 112W NEXT 
FEW DAYS...WITH GFS DEVELOPING A SIGNIFICANT SURFACE LOW IN THIS 
AREA...BUT REMAINS THE OUTLIER AT THIS TIME.

$$
STRIPLING