000
AXPZ20 KNHC 251514
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT FEB 25 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

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

THE MONSOON TROUGH EXTENDS FROM 01N100W TO 01N110W. THE ITCZ 
EXTENDS FROM 01N110W TO 05N120W TO 02N132W TO 04N140W. 

SCATTERED MODERATE CONVECTION WAS NOTED FROM 08N TO 12N BETWEEN 
102W AND 111W.

...DISCUSSION...

A WEAK SURFACE TROUGH IS ANALYZED NEAR FROM 29N123W TO 
25N124W...ASSOCIATED WITH A MID LEVEL LOW CENTERED NEAR 26N120W. 
THE PRESENCE OF THE SURFACE TROUGH AND ITS SUPPORTING MID LEVEL 
LOW HAVE DISPLACED WEAK SURFACE RIDGING FURTHER SOUTH TO ALONG 
20N...ENHANCING TRADE WIND FLOW FURTHER SOUTH ALONG THE ITCZ. 
ASCAT DATA FROM 0640 UTC SHOWED AN AREA OF FRESH TRADES FROM 10N 
TO 12N BETWEEN 105W AND 110W. THE ENHANCED TRADES ARE PROVIDING 
JUST ENOUGH LOW LEVEL CONVERGENCE TO SUPPORT SCATTERED MODERATE 
CONVECTION FROM 08N TO 12N BETWEEN 102W AND 111W. 

WEST OF THE TROUGH...A MID TO UPPER LEVEL RIDGE EXTENDS ALONG 
140W...WITH ASSOCIATED 1040 MB SURFACE HIGH PRES NEAR 42N140W. A 
TIGHT PRES GRADIENT HAS SET UP BETWEEN THE TROUGH AND THE 
RIDGE...AND SCATTEROMETER DATA OVER THE PAST SEVERAL HOURS HAVE 
SHOWN A BROAD AREA OF FRESH STRONG NE WINDS BETWEEN THESE 
FEATURES COVERING MUCH OF THE AREA N OF 25N W OF 125W. SHORT 
WAVE ENERGY EMERGING OUT OF THE FAR NW PACIFIC WILL PUSH 
SOUTHWARD OFF THE WEST COAST TONIGHT. THE MID LEVEL LOW AND 
ASSOCIATED SURFACE TROUGH LIFT OUT TO THE NE SUN AS THIS FEATURE 
MOVES EASTWARD ACROSS SOUTHERN CALIFORNIA THROUGH MON. THE 
SURFACE RIDGE REMAINS IN PLACE ALONG 20N...MAINTAINING AREAS OF 
FRESH TRADE WIND FLOW OVER MUCH OF THE AREA N OF THE ITCZ FROM 
05N TO 10N W OF 115W.

GAP WINDS...

GULF OF TEHUANTEPEC...AN UPPER LOW MOVING EASTWARD ACROSS 
NORTHERN MEXICO WILL WEAKEN AS IT TURNS NORTHEASTWARD INTO TEXAS 
TODAY. THE SURFACE REFLECTION OF THIS LOW WILL DEVELOP IN THE SW 
GULF OF MEXICO TODAY AS HIGH PRES MOVES INTO SOUTHERN TEXAS AND 
NE MEXICO. THE BUILDING PRES GRADIENT OVER THE SW GULF OF MEXICO 
AND THE CHIVELA PASS WILL SEND NORTHERLY WINDS INTO THE GULF OF 
TEHUANTEPEC THIS MORNING...WITH WINDS INCREASING TO GALE FORCE 
THIS AFTERNOON AND PEAKING AT 40 KT BEFORE DIMINISHING BELOW 
GALE FORCE SUN AFTERNOON AS HIGH PRES OVER NE MEXICO WEAKENS.

GULF OF PAPAGAYO...THE AFOREMENTIONED HIGH PRES OVER SOUTHERN 
TEXAS AND NE MEXICO TODAY WILL SHIFT NORTHEASTWARD THOUGH THE 
TENNESSEE VALLEY BY SUN MORNING AND OFF THE U.S. MID ATLC COAST 
BY MON MORNING. THE INCREASED PRES GRADIENT BETWEEN THIS HIGH 
PRES SYSTEM AND TROUGHING OVER NW SOUTH AMERICA WILL ALLOW 
SUSTAINED FRESH TO STRONG NE WINDS TO PASS THROUGH THE GULF OF 
PAPAGAYO BEGINNING OVERNIGHT TONIGHT AND CONTINUING THROUGH THE 
END OF THE PERIOD EARLY MON MORNING.

GULF OF CALIFORNIA...FRESH SW WINDS ARE EXPECTED EARLY MON 
MORNING IN THE NORTHERN GULF OF CALIFORNIA AHEAD OF A COLD FRONT 
ASSOCIATED WITH THE SYSTEM DROPPING S ALONG THE CALIFORNIA COAST 
EARLY MON. 

$$
SCHAUER/CHRISTENSEN