000
AXPZ20 KNHC 210313
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE FEB 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0115 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH WAS AXIS ANALYZED FROM 05N77W TO 00N82W THEN 
CONTINUES FROM 02N97W TO 05N117W TO 05N127W TO 01N140W. ISOLATED 
MODERATE CONVECTION WAS WITHIN 150 NM N OF AXIS BETWEEN 112W AND 
127W.

...DISCUSSION...

THE NORTHERN STREAM PATTERN WILL SLOWLY SHIFT E OVER THE NEXT 
TWO DAYS. AN UPPER ANTICYCLONE N OF THE AREA NEAR 36N138W WILL 
STRENGTHEN AS IT DRIFTS ABOUT 5 DEGREES FARTHER E...CHASING THE 
MEAN TROUGH CENTERED FROM 32N118W TO 26N127W TO 28N140W 
SOUTHEASTWARD THROUGH NE WATERS AND NW MEXICO. A NEW BATCH OF 
NORTHERN STREAM ENERGY IS DROPPING INTO THE BACKSIDE OF THE 
NORTHERN UPPER TROUGH AND WILL SLOWLY SWEEP THROUGH BAJA 
CALIFORNIA NORTE TUE. A 50-70 KT UPPER JET CURRENTLY LIES S OF 
THE TROUGH AXIS OVER WATERS E OF SOUTHERN BROAD...BUT WEAK... 
UPPER TROUGH THAT EXTENDS FROM 15N125W TO 00N115W. THIS JET IS 
TRANSPORTING MID AND HIGH LEVEL MOISTURE NORTHEASTWARD INTO W 
CENTRAL AND NE MEXICO. 

AT THE SURFACE...THE SUBTROPICAL RIDGE EXTENDS FROM THE 1035 MB 
SUBTROPICAL HIGH CENTERED NEAR 34N142W SOUTHEASTWARD TO 15N105W. 
THIS HIGH IS EXPECTED TO DRIFT E LIKE ITS PARENT ANTICYCLONE 
ALOFT. MEANWHILE...MID-LEVEL ENERGY NEAR THE SOUTHERN UPPER 
TROUGH IS ENHANCING THE SURFACE TROUGHING ALONG THE MONSOON 
TROUGH AROUND 115W-125W. THIS IS INCREASING THE PRES GRADIENT 
BETWEEN THE MONSOON TROUGH AND THE SUBTROPICAL RIDGE W OF 
115W...FORCING FRESH TO STRONG TRADE WINDS OVER MUCH OF THE 
AREA. THE MID-LEVEL ENERGY IS EXPECTED TO DRIFT WESTWARD OVER 
THE NEXT TWO DAYS AND THE AREA OF TRADE WINDS IS FORECAST TO 
SHIFT W AS WELL. IN ADDITION...SURFACE TROUGHING ASSOCIATED WITH 
THE MEAN UPPER TROUGH PASSING THROUGH BAJA CALIFORNIA WILL 
INCREASE THE PRES GRADIENT AGAINST THE SUBTROPICAL RIDGE OVER 
THE GULF OF CALIFORNIA. FRESH NW TO N WINDS ARE EXPECTED IN THE 
NORTHERN GULF OF CALIFORNIA TUE AFTERNOON THROUGH WED EVENING AS 
A RESULT. THIS TROUGHING WILL ALSO WEAKEN THE EASTERN EDGE OF 
THE RIDGE...TIGHTENING THE PRES GRADIENT OVER N CENTRAL WATERS 
AND ALLOWING FRESH N TO NE WINDS TO DEVELOP THERE BY TUE MORNING 
AND ALSO CONTRIBUTING TO THE WESTWARD MIGRATION OF THE TRADES 
THROUGH WED.

...GAP WINDS...

GULF OF TEHUANTEPEC...THE EVENT IN THE GULF OF TEHUANTEPEC HAS 
ENDED. WINDS AT SALINA CRUZ WERE SOUTHEASTERLY AT 5 KT AT 0000 
UTC AND THE ONLY OBSERVATION OF SEAS DOWNWIND OF TEHUANTEPEC WAS 
FROM SHIP DDAC2 NEAR 13N95W REPORTING 7 FT AT 0000 UTC. 

GULF OF PAPAGAYO...THE PRES GRADIENT BETWEEN RIDGING IN THE NE 
GULF OF MEXICO AND TROUGHING TO THE S OF THE GULF OF PAPAGAYO IS 
FORCING FRESH NE WINDS HERE. WINDS WILL INCREASE TO STRONG IN 
THE EARLY MORNING HOURS WITH THE AID OF LOCAL DRAINAGE FLOW. THE 
TRADE WIND FLOW OVER THE SW CARIBBEAN WILL INCREASE MON... 
ALLOWING THE AREA OF FRESH TO STRONG WINDS AND HIGHER SEAS TO 
EXPAND WESTWARD DOWNWIND OF THE GULF OF PAPAGAYO.

GULF OF PANAMA...SHIP A8SE8 REPORTED 22 KT NORTHERLY WINDS NEAR 
06N80W AT 1800 UTC. STRENGTHENING FLOW FROM THE CARIBBEAN WILL 
PUSH ACROSS THE ISTHMUS OF PANAMA AND INTO THE GULF OF PANAMA 
THROUGH WED. 

$$
SCHAUER