000
AXPZ20 KNHC 140920
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED DEC 14 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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 09N84W TO 05N108W THEN ITCZ AXIS TO 09N127W 
TO 08N140W. SCATTERED MODERATE CONVECTION WITHIN 30 NM OF TROUGH 
BETWEEN 88W AND 95W. SCATTERED MODERATE CONVECTION WITHIN 45 NM 
OF AXIS E OF 126W.

...DISCUSSION...
DEEP-LAYER LONG WAVE TROUGH ACROSS WESTERN U.S. FROM MONTANA TO 
S CALIFORNIA IS STARTING TO LIFT OUT AS A 120 KT JET MAX ROUNDS 
THE BASE OF TROUGH ACROSS NW MEXICO. HIGH AMPLITUDE BLOCKING 
PATTERN PAST FEW DAYS IS FINALLY BREAKING DOWN AS UPPER LEVELS 
BECOME ZONAL WITH PROGRESSIVE RIDGE/TROUGH PATTERN DEVELOPING.

WEAK SURFACE TROUGH PERSISTS OVER NORTHERN BAJA BUT IS WEAKENING 
RAPIDLY. ASCAT SCATTEROMETER PASS AT 0540 UTC SHOWS LIGHT TO 
MODERATE N-NW WINDS W OF BAJA CALIFORNIA. BUT N SWELL GENERATED 
FROM LONG FETCH OF 20-30 KT WINDS PAST 24 HOURS W OF CALIFORNIA 
CONTINUES TO TO SWEEP SOUTH OF 30N INTO DISCUSSION AREA. 

RIDGE OF HIGH PRES EXTENDS E-SE FROM 1028 MB HIGH NEAR 31N142W. 
PRES GRADIENT BETWEEN RIDGE AND LOWER PRES ASSOCIATED WITH ITCZ 
IS SUPPORTING FRESH E-NE TRADE WINDS W OF 120W. LITTLE CHANGE IS 
EXPECTED IN WINDS/SEAS NEXT 48 HOURS BETWEEN 10-18N W OF 120W.

EDGE OF ASCAT PASS AT 0400 UTC INDICATED PEAK WINDS ARE 25 KT IN 
THE GULF OF TEHUANTEPEC. PRES GRADIENT ACROSS THE CHIVELA PASS 
HAS WEAKENED AND WINDS IN THE SW GULF ARE VEERING SOUTHWARD SO 
EXPECT WINDS GREATER THAN 20 KT TO CONTINUE ONLY FEW MORE HOURS.

MODEL GUIDANCE SHOWS SURFACE TROUGH INTENSIFYING OVER N-CENTRAL 
MEXICO NEXT 2 DAYS...ALLOWING NW WINDS TO INCREASE TO 20 KT IN 
SOUTHERN HALF OF GULF OF CALIFORNIA THU.

$$
MUNDELL