000
AXPZ20 KNHC 222125
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC MON APR 22 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 09N86W TO 1012 MB 
LOW PRES NEAR 06N101W TO 08N114W. THE ITCZ AXIS EXTENDS FROM 
08N114W TO 06N123W TO 07N133W TO 06N140W. ISOLATED MODERATE TO 
STRONG CONVECTION IS WITHIN AN AREA BOUNDED BY 10N94W TO 03N86W 
TO 04N83W TO 10N94W. SCATTERED MODERATE CONVECTION IS FROM 03N 
TO 05N BETWEEN 102W AND 106W...WITHIN 60 TO 120 NM N OF THE ITCZ 
BETWEEN 112W AND 117W...FROM 04N TO 07N BETWEEN 119W AND 123W... 
AND WITHIN 120 NM S OF ITCZ BETWEEN 127W AND 134W.

...DISCUSSION...                                                 

AN UPPER LEVEL RIDGE IS OVER THE SE DISCUSSION WATERS            
EXTENDING FROM NEAR 09N83W THROUGH 14N95W TO 14N107W...WHERE IT 
IS DISRUPTED BY AN UPPER LEVEL TROUGH...WITH ANOTHER RIDGE 
EXTENDING INTO THE SW PORTION OF THE AREA FROM 02N140W TO 
07N118W. ISOLATED TO SCATTERED CONVECTION UNDER UPPER DIFFLUENCE 
IS NOTED BELOW BOTH UPPER RIDGES AS IS DESCRIBED ABOVE. THIS 
REGION ALSO CORRESPONDS TO THE HIGHEST PRECIPITABLE WATER VALUES 
OBSERVED IN THE FORECAST AREA. 

AN UPPER CYCLONE IS CENTERED NEAR 32N133W AND IS MOVING TO THE 
NE-E...WITH THE AFOREMENTIONED UPPER TROUGH REACHING S-SE FROM 
THE CYCLONE CENTER THROUGH 29N130W TO 27N126W WHERE IT FLATTENS 
WITH SEMI-ZONAL FLOW PRESENT FROM 22N TO 26N...CONTINUING FROM 
NEAR 22N122W TO 08N115W. A WEAK SURFACE REFLECTION OF THE TROUGH 
IS NOTED FROM NEAR THE CALIFORNIA CHANNEL ISLANDS NEAR 33N121W 
TO 27N131W. LITTLE SENSIBLE WEATHER IMPACT IS EXPECTED WITH THE 
SURFACE TROUGH...WHILE THE UPPER LEVEL TROUGH WILL HELP TO 
ENHANCE PRECIPITATION ALONG THE ITCZ.

1037 MB HIGH PRES IS CENTERED WELL N OF THE DISCUSSION WATERS W 
OF VANCOUVER ISLAND NEAR 52N132W...EXTENDING A SURFACE RIDGE 
THROUGH 10N138W TO 32N137W...THEN SOUTHEASTWARD TO 20N111W. 
MAINLY LIGHT TO MODERATE TRADE WINDS EXIST SW OF THE RIDGE AXIS 
AND N OF THE ITCZ AXIS...WITH LOCALLY FRESH NEAR 10N140W. WINDS 
ARE FORECAST TO REMAIN BELOW 25 KT OVER THE ENTIRE FORECAST AREA 
THROUGH AT LEAST WED AFTERNOON...BUT NORTHERLY WINDS ALONG THE 
CALIFORNIA COAST N OF THE AREA SHOULD BECOME STRONG ENOUGH TO 
GENERATE AND THEN PROPAGATE N-NE SWELL WITH 8-9 FT SEAS INTO THE 
WATERS N OF 29N BETWEEN 130W AND 136W BY LATE TUE NIGHT THROUGH 
AT LEAST WED AFTERNOON.

THE RESIDUAL NE SWELL FROM THE FORMER GALE IN THE GULF OF 
TEHUANTEPEC HAS SUBSIDED TO 6-7 FT DURING THE PAST SEVERAL 
HOURS.

$$
LEWITSKY