000
AXPZ20 KNHC 182203
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT FEB 18 2012

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...

MONSOON TROUGH FROM 00N89W TO 06N105W TO LOW PRES NEAR 05N117W 
1009 MB TO 03N125W. ITCZ FROM 03N125W TO BEYOND 01N140W. WITHIN 
60 NM N OF TROUGH AND 180 NM S OF TROUGH SCATTERED MODERATE 
ISOLATED STRONG CONVECTION BETWEEN 110W AND 120W.

...DISCUSSION...

VIGOROUS SHORT WAVE ENERGY MOVING TOWARD SOUTHERN CALIFORNIA IS 
ROUNDING THE BASE OF A LONG WAVE TROUGH THAT EXTENDS FROM THE 
NORTHERN ROCKIES TO 32N125W TO 33N140W. AN ATTENDANT COLD FRONT 
ANALYZED JUST NORTH OF THE DISCUSSION AREA FROM SOUTHERN 
CALIFORNIA TO 31N125W TO 32N135W WILL PUSH THROUGH NORTHERN BAJA 
AND THE ADJACENT PACIFIC WATERS W OF 125W ON SUN. THE FRONT WILL 
DISSIPATE INTO MON AS THE SUPPORTING UPPER DYNAMICS LIFT NE OF 
THE AREA THROUGH THE SOUTHWEST UNITED STATES. FRESH NW TO N 
WINDS WILL FOLLOW THE FRONT ALONG THE NORTHERN BAJA COAST 
THROUGH SUN. 

FURTHER SOUTH...A BROAD NEGATIVELY TILTED MID/UPPER TROUGH 
EXTENDS FROM 16N125W TO 05N115W...TO THE WEST OF A AN UPPER 
RIDGE CENTERED OVER SOUTHERN CENTRAL AMERICA. UPPER FORCING 
ASSOCIATED WITH THE RIGHT REAR ENTRANCE AREA OF THE RESULTING 
UPPER JET BETWEEN THESE FEATURES IS AIDING DEVELOPMENT OF 
CLUSTERS OF SCATTERED MODERATE CONVECTION FROM 08N TO 12N 
BETWEEN 105W TO 120W. SATELLITE DERIVED PRECIPITABLE WATER 
VALUES REMAIN FAIRLY HIGH OVER THE EASTERN PACIFIC...PROVIDING 
COPIOUS MID AND UPPER LEVEL MOISTURE ALONG THE SOUTHERN STREAM 
JET ACROSS MEXICO AND INTO THE DEEP SOUTH STATES. 

THE UPPER TROUGH IS ALSO SUPPORTING A PERSISTENT 1009 MB SURFACE 
LOW NEAR 05N117W. A SOMEWHAT TIGHT PRES GRADIENT BETWEEN THIS 
SURFACE LOW AND STRONG 1037 MB HIGH PRES CENTERED NEAR 34N142W 
IS MAINTAINING FRESH TO STRONG NE FLOW FROM 05N TO 25N W OF 
115W. MEANWHILE NW SWELL WITH 10 TO 15 SECOND PERIODS AND 
HEIGHTS OF 8 TO 12 FT CONTINUE TO PUSH INTO THE AREA AND MIX 
WITH FRESH NE SWELL ASSOCIATED WITH THE PERSIST TRADE WIND FLOW. 

...GAP WINDS...

GULF OF TEHUANTEPEC...EXPECT INCREASING WINDS AND SEAS ACROSS 
THE GULF OF TEHUANTEPEC BY SUN AFTERNOON AS A STRONG...BUT FAST 
MOVING...COLD FRONT MOVES THROUGH CHIVELA PASS. THE NORTHERLY 
WINDS THROUGH THE PASS INTO THE GULF OF TEHUANTEPEC ARE FORECAST 
TO BRIEFLY REACH GALE FORCE OVERNIGHT SUN NIGHT BEFORE 
DIMINISHING BELOW GALE BY SUNRISE ON MON.

GULF OF PAPAGAYO...NE TO E WINDS WILL CONTINUE TO PULSE TO 20 KT 
THROUGH THE GULF OF PAPAGAYO THROUGH MON MORNING. THE STRONGEST 
WINDS WILL OCCUR DURING THE EARLY MORNING HOURS WITH THE AID OF 
DRAINAGE FLOW. 
 
$$
CHRISTENSEN