000
AXPZ20 KNHC 222122
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI FEB 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 IS ALONG 03N77W TO 08N87W TO 04N94W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N94W TO 
04N110W TO 07N125W TO 07N140W. SCATTERED MODERATE CONVECTION IS 
WITHIN 45 NM EITHER SIDE OF THE MONSOON TROUGH BETWEEN 82W AND 
86W...FROM 07N TO 10N BETWEEN 117W AND 120W...AND ALSO WITHIN 75 
NM N OF THE ITCZ BETWEEN 122W AND 130W.

...DISCUSSION...

ALOFT...                                                         
A LARGE UPPER LEVEL TROUGH ACROSS THE INTERMOUNTAIN REGION OF 
THE U.S. STRETCHES SSW ACROSS N BAJA CALIFORNIA...THEN SW TO 
NEAR 25N122W WHERE UPPER LEVEL MODEL AND SATELLITE WIND DATA 
INDICATE THAT IT WEAKENS TO A SHEAR AXIS EXTENDING W-NW TO 
28N140W. HIGHLY AMPLIFIED UPPER LEVEL RIDGING IS WELL NW OF THE 
AREA WITH A CREST THAT SPILLS SE ACROSS THE FAR PACIFIC NW 
REGION. A VERY ACTIVE SUBTROPICAL JET STREAM STRETCHES FROM THE 
DEEP CENTRAL TROPICAL PACIFIC REGION TO THE NE-E TO ACROSS 
CENTRAL MEXICO AND THE U.S. GULF OF MEXICO STATES. SATELLITE 
DERIVED WINDS INDICATE A WIND MAXIMUM IN THE RANGE OF 90-110 KT 
IN THE JET CORE REGION FOUND FROM 18N TO 23N W OF 120W. 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 16N TO 24N W OF 120W. SIMILAR CLOUDS ARE BEING CHANNELED NE 
WITHIN 420 NM EITHER SIDE OF A LINE FROM 23N106W TO 17N120W TO 
16N127W. OVER THE S HALF OF THE AREA...AN UPPER LEVEL TROUGH 
EXTENDS FROM NEAR 14N111W TO S OF THE EQUATOR NEAR 00N109W.

CONFLUENT FLOW INTO THE BASE OF THE UPPER TROUGH IS RESULTING
IN MODERATE SUBSIDENCE WITH ASSOCIATED DRY AND STABLE CONDITIONS 
OVER THE NE PORTION N OF ABOUT 25N E OF 120W. OUTSIDE THE 
TROPICAL BELT REGION...ATMOSPHERIC CONDITIONS ARE STABLE AS 
NORMAL FOR THIS TIME OF YEAR WITH SCATTERED TO BROKEN 
STRATOCUMULUS TYPE CLOUDS MOVING S-SW N OF 15N.

SURFACE...STRONG 1037 MB HIGH CENTER REMAINS ANCHORED NW OF THE 
AREA AT 36N146W WITH A RIDGE EXTENDING SE THROUGH 32N136W TO 
25N120W WITH A TERMINUS NEAR 14N97W. THE PRES GRADIENT FOUND S 
OF THE RIDGE AND N OF THE ITCZ CONTINUES TO SUPPORT NE-E WINDS 
OF 20-25 KT WINDS FROM 08N-27N W OF 130W...AND ALSO FROM 11N TO 
20N BETWEEN 120W AND 130W. THE SEA STATE IS IN THE 8-11 FT RANGE 
ACROSS THESE SAME AREAS. THE 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. 

BY 48 HOURS...A TIGHTER PRES GRADIENT OVER E PACIFIC WATERS OFF 
THE COAST OF CALIFORNIA IS EXPECTED TO FUNNEL IN N WINDS OF 
20-25 KT INTO THE FAR NRN WATERS N OF 26N AND BETWEEN 118W-128W 
WITH A NEW SET OF LARGE NW SWELL OF 11-16 FT ACROSS THE SAME 
AREA.

GAP WINDS...                                                     
NE-E 20-25 KT WINDS WILL PULSE IN THE GULF OF PAPAGAYO LATER 
TONIGHT THROUGH SAT MORNING...DIMINISHING BY SAT AFTERNOON. 
WINDS WILL LIKELY REMAIN MODERATE TO FRESH DURING SUBSEQUENT 
NIGHTS THROUGH EARLY NEXT WEEK.

$$
LEWITSKY