000
AXPZ20 KNHC 160931
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JAN 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 5N78W 8N85W 5N100W TO 6N105W. ITCZ 6N105W TO 
06N107W 8N125W 5N135W TO 07N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...
UPPER LEVEL RIDGE OVER THE FAR WESTERN PORTION OF THE DISCUSSION 
AREA IS N OF 20N W OF 135W. DOWNSTREAM UPPER LEVEL TROUGH 
EXTENDS FROM 32N133W TO 15N120W. AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION IS CENTERED OFF THE CENTRAL COAST OF CALIFORNIA WITH 
A RIDGE EXTENDING SOUTHWARD TO OFF THE N COAST OF THE BAJA 
PENINSULA. A 100-135 KT JETSTREAM FROM SOUTHERN BAJA CALIFORNIA 
INTO NORTHERN MEXICO. BROKEN TO OVERCAST MID AND HIGH LEVEL 
CLOUDS ARE WITHIN 500 NM S OF THE JET. MODERATE TO STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS 
WITHIN 500 NM N OF THE JETSTREAM.

SURFACE HIGH PRES N  OF THE AREA PRODUCING A TIGHT ENOUGH PRES 
GRADIENT ACROSS THE DISCUSSION AREA WITH 20 KT ELY WINDS FROM 
10N-25N W OF 115W...WITH SEAS TO 12 FT.

THE PRES GRADIENT HAS TIGHTENED BETWEEN HIGH PRES OVER THE 
WESTERN U.S. AND LOW PRE OVER CENTRAL MEXICO IS RESULTING IN NLY 
WINDS 20-30 KT ACROSS THE GULF OF CALIFORNIA. THE GRADIENT 
RELAXES AND WINDS DECREASE TO LESS THAN 20 KT THU EVENING.

STRONG HIGH PRES BUILDS ACROSS THE GULF OF MEXICO AND TIGHTENS 
THE PRES GRADIENT OVER SOUTHERN MEXICO WED NIGHT RESULTING IN 
STORM FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC WITH WINDS UP 
TO 50 KT. WINDS DECREASE BACK TO GALE FORCE BY THU NIGHT.

$$
DGS