000
AXPZ20 KNHC 090343
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON FEB 09 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0130 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 05N78W 
TO 02N95W TO 03N110W TO 04N125W TO 05N140W. SCATTERED MODERATE 
CONVECTION CAN BE FOUND WITHIN 30 NM OF THE ITCZ AXIS FROM 92W 
TO 96W AND WITHIN 210 NM N OF ITCZ AXIS W OF 130W.

...DISCUSSION...
THE UPPER TO MID LEVEL PATTERN WILL BE PROGRESSIVE AND SOMEWHAT 
AMPLIFIED OVER N WATERS THE NEXT FEW DAYS.  THE TROUGH CURRENTLY 
OVER THE GULF OF CALIFORNIA EXTENDING NORTH TO A MID LEVEL LOW 
OVER THE GREAT BASIN WILL QUICKLY MOVE EASTWARD.  THE QUIKSCAT 
PASS FROM 1320 UTC HAD SHOWN WINDS TO 25 KT OFF THE SOUTHERN TIP 
OF THE BAJA CALIFORNIA PENINSULA.  WITH THE UPPER LEVEL SUPPORT 
PASSING QUICKLY TO THE EAST...EXPECT THESE WINDS TO FALL BELOW 
20 KT OVERNIGHT TONIGHT...BUT THE NEXT TROUGH IS EXPECTED TO 
MOVE INTO A SIMILAR POSITION TUE...BRINGING WINDS BACK ABOVE 20 
KT HERE BY TUE AFTERNOON.  

STRONGER WINDS...IN THE 25 TO 30 KT RANGE...OFF THE PACIFIC 
COAST OF THE BAJA PENINSULA N OF 25N SHOULD ALSO ABATE SOME 
OVERNIGHT TONIGHT.  HOWEVER...THE PROGRESSIVE PATTERN WILL BRING 
THE NEXT TROUGH INTO THESE NE WATERS TOMORROW...INCREASING WINDS 
TO 25 KT AGAIN OFF THE NORTHERN BAJA COAST BY MON AFTERNOON.  
THE COLD FRONT ASSOCIATED WITH THIS SECOND TROUGH IS CURRENTLY 
JUST N OF NW WATERS.  IT IS EXPECTED TO WEAKEN AT THE SURFACE AS 
THE DEEP LAYER TROUGH RAPIDLY MOVES EASTWARD.  THE SURFACE HIGH 
PRESSURE RIDGE CURRENTLY TO ITS S ALONG 30N140W TO 27N130W TO 
24N112W IS EXPECTED TO BUILD OVER THE NEXT FEW DAYS AND SHIFT 
SLIGHTLY TO THE NORTH...HELPING WASH OUT THE COLD FRONT AT THE 
SURFACE.

SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 210 NM N OF 
ITCZ AXIS W OF 130W.  THIS CONVECTION IS SUPPORTED BY UPPER 
LEVEL DIFFLUENCE OVER THIS REGION WHERE THE WESTERLY JET 
SPLITS...TAKING THE JET CORE ON A SOUTHWARD TURN S OF THE 
ANTICYCLONE CENTERED NEAR 10N100W WHILE SOME OF THE WESTERLY 
FLOW IS DIRECTED N OF THE ANTICYCLONE...PASSING N OF THE UPPER 
HIGH CENTER.  CONVECTION IS LIKELY TO PERSIST IN THIS REGION AS 
THE UPPER LEVEL FLOW IS EXPECTED TO REMAIN LARGELY DIFFLUENT 
AROUND 10N W OF 120W FOR THE NEXT FEW DAYS.

GAP WINDS...THE 1138 QUIKSCAT PASS STILL SUPPORTED WINDS TO 30 
KT DOWNWIND OF THE GULF OF PAPAGAYO.  UNFORTUNATELY...THE LATER 
ASCAT PASSES MISSED THIS REGION.  SHIP OBSERVATION V7DI7 
REPORTED 16 KT NEAR 10N92W AT 0000 UTC.  THIS OBSERVATION FELL 
IN THE SMALL REGION OF MINIMUM WINDS IN THE EARLIER QUIKSCAT 
PASS...SO IT IS HARD TO TELL IF THE LARGE SCALE WIND FIELD HAS 
CHANGED BASED ON THIS OBSERVATION.  COMPUTER MODELS SHOW LITTLE 
CHANGE IN CONDITIONS HERE OVER THE NEXT DAY...BUT WINDS SHOULD 
DIMINISH SLIGHTLY BY TUE AS PRESSURES LOWER OVER THE WESTERN 
GULF OF MEXICO AND CARIBBEAN UNDER THIS PROGRESSIVE MID LATITUDE 
PATTERN.  SIMILARLY...THE WINDS OFF WESTERN PANAMA...WHICH WERE 
AT 20 TO 25 KT ACCORDING TO THE 1448 ASCAT PASS...SHOULD SLOWLY 
DIMINISH OVER THE NEXT TWO DAYS.  THE IMPACT OF THE PROGRESSIVE 
PATTERN IS ALREADY BEING FELT IN THE GULF OF TEHUANTEPEC WHERE 
THE 1626 ASCAT PASS SHOWED A SUBSTANTIAL DECREASE IN THE WIND 
FIELD COMPARED TO THIS TIME YESTERDAY...AND WINDS TO 30 KT WERE 
CONFINED TO VERY CLOSE TO SHORE.  WINDS HERE SHOULD DIMINISH 
BELOW 20 KT MON MORNING.  

$$
SCHAUER CLARK