000
AXPZ20 KNHC 241545
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN FEB 24 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1430 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 09N75.5W TO 03N80W TO 07.5N86W TO 
06N90W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 04N98W 
TO 06N113W TO 07N127W TO BEYOND 06N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION NOTED WITHIN 150 NM S OF TROUGH AXIS 
E OF 86W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 
180 NM N AND 90 NM S OF ITCZ BETWEEN 110W AND 128W.

...DISCUSSION...                                                 
A LARGE UPPER LEVEL TROUGH PERSISTS ACROSS THE INTERMOUNTAIN 
REGION OF THE U.S. THIS MORNING AND STRETCHES SSW ACROSS N BAJA 
CALIFORNIA...WHERE A NEW SHORTWAVE HAS DROPPED INTO THE BACKSIDE 
OF THIS TROUGH TO REDEFINE IT TO NEAR 28.5N121W. UPPER LEVEL 
MODEL AND SATELLITE WIND DATA INDICATE THAT IT WEAKENS TO A 
MIDDLE TO UPPER LEVEL SHEAR AXIS EXTENDING W TO AN UPPER CYCLONE 
NEAR 25N143W. HIGHLY AMPLIFIED UPPER LEVEL RIDGING IS WELL NW OF 
THE AREA WITH A CREST THAT SPILLS SE ACROSS THE FAR PACIFIC NW 
REGION INTO THE BACKSIDE OF THE NW U.S. TROUGH. A VERY ACTIVE 
SUBTROPICAL JET STREAM STRETCHES FROM THE DEEP CENTRAL TROPICAL 
PACIFIC REGION TO THE NE THEN E TO ACROSS THE S BAJA CALIFORNIA 
AND CENTRAL MEXICO THEN NE ACROSS THE NORTHERN GULF OF MEXICO 
COASTAL WATERS. SATELLITE DERIVED WINDS INDICATE A WIND 
MAXIMUM IN THE RANGE OF 80-115 KT IN THE JET CORE REGION FOUND 
FROM 18N TO 23N E OF 128W. THIS JET STREAM IS HELPING TO ADVECT 
UPPER LEVEL MOISTURE IN THE FORM OF MOSTLY SCATTERED TO BROKEN 
HIGH CLOUDS EASTWARD OVER THE AREA FROM 10N TO 25N. OVER THE S 
HALF OF THE AREA...AN UPPER LEVEL TROUGH EXTENDS FROM NEAR 
14N98W TO S OF THE EQUATOR NEAR 00N99W.

CONFLUENT FLOW INTO THE BASE OF THE NW U.S. UPPER TROUGH IS 
RESULTING IN MODERATE SUBSIDENCE WITH ASSOCIATED VERY DRY AND 
STABLE AIR PLUNGING S OVER THE NE PORTION N OF ABOUT 26N E OF 
127W. 

SURFACE...STRONG 1033 MB HIGH CENTER REMAINS ANCHORED NW OF THE 
AREA NEAR 35N147W WITH A RIDGE EXTENDING SE THROUGH 32N131W TO 
15N110W. THE PRES GRADIENT FOUND S OF THE RIDGE AND N OF THE 
ITCZ CONTINUES TO SUPPORT NE-E WINDS OF 20-25 KT FROM 08N TO A 
LINE FROM 27N140W TO 24N130W TO 13N123W...AS DEPICTED BY 
OVERNIGHT SCATTEROMETER PASSES...YIELDING SEAS 9-11 FT IN MIXED 
NE AND NW SWELL. CLUSTERS OF DEEP CONVECTION ACROSS S PORTIONS 
OF THIS ZONE HAVE INDUCED UPPER LEVEL RIDGING FROM 07N TO 13N 
BETWEEN 117W AND 127W...AIDING IN MAINTAINING DEEP CONVECTION. 
THE SURFACE HIGH IS FORECAST TO MIGRATE VERY SLOWLY E OVER THE 
NEXT 48 HOURS WHILE WEAKENING SLIGHTLY. THIS WILL ALLOW FOR THE 
AREA OF 20-25 KT WINDS TO DIMINISH TO W OF 130W WITH SEAS 
REMAINING IN THE 8-11 FT RANGE. 

LATE THIS AFTERNOON THROUGH TONIGHT...A TIGHTENING PRES GRADIENT 
FROM THE NW U.S. SOUTHWARD THROUGH THE GULF OF CALIFORNIA WILL  
FUNNEL IN NLY WINDS OF 20-30 KT INTO THE FAR NRN WATERS N OF 26N 
AND SPREAD S THROUGH THE ENTIRE GULF BY MON MORNING...WITH SEAS 
BUILDING TO 10 FT. WIND AND SEAS WILL THEN BEGIN TO DIMINISH MON 
NIGHT. 


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STRIPLING