000
AXPZ20 KNHC 260930
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED OCT 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 11N86W TO 09N98W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 09N98W TO 10N115W TO 11N129W 
THEN RESUMES FROM 11N133W TO 08N140W. NO SIGNIFICANT CONVECTION 
ASSOCIATED WITH THE MONSOON TROUGH AND ITCZ IS NOTED...HOWEVER 
SCATTERED MODERATE CONVECTION IS IN THE GULF OF PANAMA N OF 05N 
E OF 80W. 

...DISCUSSION...

A DEEPENING UPPER LEVEL TROUGH EXTENDS FROM NEAR POINT 
CONCEPTION CALIFORNIA TO 32N126W TO AN UPPER LOW NEAR 23N136W TO 
15N140W. SOUTHERLY FLOW AHEAD OF THE TROUGH IS ADVECTING 
MOISTURE FROM THE TROPICS NORTHEASTWARD TO ACROSS THE BAJA 
CALIFORNIA PENINSULA AND FAR NW MEXICO. UPPER RIDGING DOMINATES 
THE AREA N OF 10N AND E OF THE TROUGH EXTENDING FROM A PARENT 
ANTICYCLONE OVER CENTRAL MEXICO NEAR 24N102W. THE UPPER TROUGH 
WILL FLATTEN WHILE SHIFTING WESTWARD AS THE UPPER RIDGING E OF 
IT SHIFTS AND EXPANDS TO THE W.

1030 MB SURFACE HIGH PRES IS N OF THE AREA NEAR 38N134W WITH A 
RIDGE AXIS EXTENDING INTO THE AREA NEAR 32N135W TO 23N115W. A 
TIGHT PRES GRADIENT IS OVER THE NW PORTION BETWEEN THIS HIGH AND 
LOWER PRES TO THE S RESULTING IN NE-E 20 KT WINDS N OF 24N W OF 
130W AS CAPTURED BY A 0554 UTC ASCAT SCATTEROMETER PASS. 
MEANWHILE MIXED NE AND NW SWELL IS OVER THE NW PORTION WITH SEAS 
TO 11 FT AS DEPICTED BY AN EARLIER 23 UTC JASON ALTIMETER PASS. 
THESE WINDS WILL GRADUALLY DIMINISH TO LESS THAN 20 KT BY 48 
HOURS AS THE GRADIENT WEAKENS OVER THIS AREA...WITH SEAS ALSO 
SUBSIDING TO LESS THAN 8 FT AT THE SAME TIME.

A SURFACE TROUGH EXTENDS FROM 21N122W TO 15N128W TO LOW PRES 
NEAR 12N130W 1010 MB. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION IS FROM 12N TO 16N BETWEEN 128W AND 131W. THE SAME 
ASCAT SCATTEROMETER PASS INDICATED NE-E 20 KT WINDS FROM 12N TO 
20N W OF THE TROUGH WHERE A TIGHT PRES GRADIENT IS ALSO PRESENT 
BETWEEN THE SURFACE LOW AND THE ABOVE MENTIONED RIDGING OVER THE 
NW PORTION OF THE AREA. THE LOW AND TROUGH WILL MOVE W THROUGH 
THE NEXT 48 HOURS SHIFTING THE AREA OF FRESH WINDS WESTWARD WITH 
THE FEATURE PROGRESSION.

HI-RES ASCAT WINDS AT 0412 UTC CAPTURED SW-W 20-25 KT WINDS IN 
THE FAR NORTHERN GULF OF CALIFORNIA DUE TO TROUGHING ALONG THE E 
COAST OF THE GULF AND THE RIDGING W OF THE PENINSULA AS 
DESCRIBED ABOVE. FRESH WINDS WILL BECOMING NORTHERLY AND EXPAND 
TO ENCOMPASS THE ENTIRE GULF WATERS N OF 23N BY 48 HOURS AS THE 
GRADIENT TIGTHENS WITH A STRONG COLD FRONT MOVING FROM SW TEXAS 
INTO NORTHERN MEXICO.

THE SAME ASCAT HI-RES WINDS ALSO INDICATED 20-30 KT NORTHERLY 
WINDS IN THE GULF OF TEHUANTEPEC WITH ACCOMPANYING SEAS EXPECTED 
TO BE IN THE 8-11 FT RANGE. THESE WINDS WILL DIMINISH AND SEAS 
WILL SUBSIDE TO BELOW ADVISORY CRITERIA BY THIS EVENING. LOOKING 
AHEAD...A STRONG COLD FRONT WILL MOVE THROUGH THE SW GULF OF 
MEXICO FRI NIGHT WITH A SURGE OF STRONG NORTHERLY WINDS EXPECTED 
TO FUNNEL FROM THE GULF THROUGH THE CHIVELA PASS AND INTO AND 
DOWNWIND OF THE GULF OF TEHUANTEPEC WITH GALE CONDITIONS 
EXPECTED LATE FRI NIGHT THROUGH SAT.

$$
LEWITSKY