000
AXPZ20 KNHC 260921
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN FEB 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0715 UTC.

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

THE ITCZ AXIS EXTENDS FROM 01N120W TO 01N130W TO 00N135W. THERE 
IS NO SIGNIFICANT CONVECTION NEAR THE ITCZ.

...DISCUSSION...

THE SUBTROPICAL HIGH IS WELL N OF THE AREA NEAR 42N149W. THIS 
1038 MB HIGH EXTENDS A RIDGE SOUTHEASTWARD TO 28N120W. THE 
SOUTHEASTERN SIDE OF THE SUBTROPICAL RIDGE IS BEING ERODED BY A 
DISSIPATING MID LEVEL LOW CURRENTLY NEAR 28N120W. THE LOW LEVEL 
REFLECTION OF THIS SYSTEM IS WEAKENING THE SURFACE RIDGING OFF 
THE COAST OF BAJA CALIFORNIA AND SHIFTING THE TIGHTEST PRES 
GRADIENT TO ITS W OVER NORTHWESTERN FORECAST WATERS WITH FRESH 
TO STRONG NE WINDS SEEN W OF A LINE FROM 30N120W TO 16N140W 
ACCORDING TO THE 0510 ASCAT PASS AND THE 0320 WINDSAT PASS. THE 
LOW ALOFT IS BEING OVERTAKEN BY THE DEEP LAYER TROUGH MOVING 
INTO NE WATERS. THIS TROUGH WILL QUICKLY BE RELOADED BY A SYSTEM 
DROPPING S ALONG THE CALIFORNIA COAST EARLY MON AND MOVING E 
INTO THE SOUTHWESTERN U.S. BY EARLY TUE. THE PRES GRADIENT OVER 
NW WATERS WILL SLACKEN THROUGH EARLY MON AND THEN THE 
SUBTROPICAL RIDGE WILL BUILD EASTWARD ACROSS N WATERS THROUGH 
EARLY TUE...ALLOWING NE TRADE WINDS TO RETURN TO THEIR 
CLIMATOLOGICAL POSITION OVER W CENTRAL WATERS. 

GAP WINDS...

GULF OF TEHUANTEPEC...THE 0324 UTC ASCAT PASS CAPTURED ABOUT TWO 
THIRDS OF THE AREA IN THE GULF OF TEHUANTEPEC EXPERIENCING GAP 
WINDS. THE PASS SHOWED THE STRONGEST WINDS WERE JUST BELOW GALE 
FORCE. IN ADDITION TO THE ASCAT INSTRUMENT TENDING TO BE TOO 
LIGHT WITH WINDS THIS STRONG...THE PASS OCCURRED BEFORE THE 
DIURNAL MAXIMA OF DRAINAGE FLOW FROM THE MOUNTAINS AND MISSED A 
THIRD OF THE AREA. THE GALE WARNING WILL CONTINUE UNTIL AFTER 
THE DIURNAL MAXIMA IN DRAINAGE FLOW OCCURS IN THE MORNING HOURS. 
WHILE WINDS WILL DIMINISH BELOW GALE FORCE BY THIS AFTERNOON... 
LOOK FOR STRONG N TO NE WINDS TO CONTINUE OVER THE GULF OF 
TEHAUNTEPEC THROUGH TUE MORNING.

GULF OF PAPAGAYO...THE PRES GRADIENT OVER CENTRAL AMERICA IS 
INCREASING BETWEEN HIGH PRES OVER THE EASTERN U.S. AND TROUGHING 
OVER COLOMBIA AND ADJACENT PACIFIC WATERS. THIS GRADIENT IS 
RESPONSIBLE FOR SUSTAINED FRESH TO STRONG NE WINDS IN THE GULF 
OF PAPAGAYO THIS MORNING THROUGH THE END OF THE FORECAST PERIOD 
EARLY TUE MORNING. IN ADDITION...MID LEVEL ENERGY EXTENDING 
DOWNWIND FROM PAPAGAYO IS EXPECTED TO GRADUALLY REFLECT DOWN TO 
THE SURFACE...INCREASING THE TROUGHING ALONG THE ITCZ/MONSOON 
TROUGH S OF PAPAGAYO AND EXPANDING THE AREA OF FRESH NE WINDS AS 
FAR AS 104W BY TUE MORNING.

GULF OF CALIFORNIA...FRESH SW WINDS ARE EXPECTED IN THE 
NORTHERN GULF OF CALIFORNIA AHEAD OF A COLD FRONT ASSOCIATED 
WITH THE SYSTEM DROPPING S ALONG THE CALIFORNIA COAST EARLY MON. 
THE COLD FRONT WILL LIE FROM 31N113W TO 30N115W BY EARLY TUE 
MORNING...WITH FRESH NW WINDS BEHIND IT AND FRESH SW WINDS N OF 
29N AHEAD OF IT.

$$
SCHAUER