000
AXPZ20 KNHC 151510
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN FEB 15 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1315 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 05N77W 
TO 04N86W TO 02N100W TO 03N115W TO 03N140W. NO SIGNIFICANT 
CONVECTION CAN BE FOUND NEAR THE ITCZ.

...DISCUSSION...
THE SOUTHERN EDGE OF A SLOW MOVING DEEP LAYER LOW LIES OVER N 
WATERS...WITH ITS SURFACE COLD FRONT FOUND FROM 30N128W TO 
27N134W TO 27N140W.  NW SWELL WITH SEAS IN THE 15 TO 18 FT RANGE 
IS MAKING ITS WAY INTO N WATERS OVER THE NEXT 24 HOURS.  THE 
ASCAT PASSES AT 0454 AND 0634 UTC ALONG WITH THE QUIKSCAT PASSES 
AT 0230 AND 0410 UTC SHOW WINDS TO 30 KT ASSOCIATED WITH THE 
COLD FRONT...WITH GALE CONDITIONS JUST N OF THE FORECAST AREA.  
UPPER LEVEL DIFFLUENCE WITH THE REAR RIGHT QUADRANT OF A 150 KT 
SOUTHWESTERLY UPPER JET ON THE SE EDGE OF THE LOW HAS MADE 
CONDITIONS RIPE FOR SCATTERED MODERATE CONVECTION WHICH CAN BE 
FOUND WITHIN 45 NM OF THE COLD FRONT FROM 30N128W TO 28N132W.  
THIS SOUTHWESTERLY JET IS TRANSPORTING MID TO UPPER LEVEL 
MOISTURE NORTHEASTWARD ACROSS FORECAST WATERS ALONG AN AXIS FROM 
17N140W INTO NORTHERN BAJA CALIFORNIA.  MULTILAYERED CLOUDINESS 
WITH SOME EMBEDDED SHOWERS CAN BE FOUND ALONG THIS AXIS SE OF 
THE FRONT.  THE DEEP LAYER LOW SUPPORTING THE COLD FRONT SHOULD 
SLOWLY MOVE EASTWARD THROUGH MON MORNING.  BY MON AFTERNOON...A 
NEW BATCH OF MID LATITUDE ENERGY WILL MOVE INTO THE BACKSIDE OF 
THE BROAD TROUGH OVER THE NE PACIFIC AND SHOVE THE DEEP LAYER 
LOW MORE QUICKLY INTO CALIFORNIA AND WEAKEN IT.  BY TUE 
MORNING...THE ASSOCIATED COLD FRONT IS EXPECTED TO DISSIPATE 
OVER NE WATERS AND WINDS ARE EXPECTED TO DROP TO 20 KT. 

NEAR BAJA CALIFORNIA...THE INCREASED PRESSURE GRADIENT BETWEEN 
THE 1019 MB SURFACE HIGH NEAR 27N121W AND LOW PRESSURE OVER 
MAINLAND MEXICO N OF 20N HAS INDUCED WINDS OVER 20 KT OVER THE 
SOUTHERN GULF OF CALIFORNIA THIS MORNING.  THE QUIKSCAT PASS 
FROM 1340 UTC OVER THE SOUTHERN GULF OF CALIFORNIA HAD WINDS TO 
25 KT.  THIS HIGH PRESSURE SYSTEM WILL CONTINUE TO MOVE EASTWARD 
AHEAD OF THE COLD FRONT OVER N WATERS...KEEPING WINDS ABOVE 20 
KT HERE THROUGH MON.  BY MON EVENING...WINDS IN THE NORTHERN 
GULF OF CALIFORNIA SHOULD PICK UP AHEAD OF THE APPROACHING COLD 
FRONT WHILE THE PRESSURE GRADIENT BEGINS TO RELAX FARTHER SOUTH 
IN THE GULF OF CALIFORNIA.

SUBSIDENCE UNDER A SPRAWLING UPPER LEVEL ANTICYCLONE CENTERED 
NEAR 10N90W WITH DRY MID TO UPPER LEVELS CAN BE FOUND OVER MUCH 
OF CENTRAL AMERICA S OF 20N AND OVER MUCH OF THE PACIFIC 
FORECAST WATERS S OF 20N E OF 115W.  NO SIGNIFICANT CONVECTION 
CAN BE FOUND ALONG THE ITCZ AT THIS TIME.

THE QUIKSCAT PASS AT 1156 UTC SHOWS EASTERLY WINDS ARE STILL IN 
THE 20 TO 25 KT RANGE DOWNWIND OF THE GULF OF PAPAGAYO.  WINDS 
SHOULD HOVER AROUND 20 KT HERE INTO MON AND THEN INCREASE TUE AS 
WINDS IN THE WESTERN CARIBBEAN INCREASE AND TURN MORE NORTHERLY 
BEHIND A FAST MOVING COLD FRONT PASSING THROUGH THE GULF OF 
MEXICO.  THIS COLD FRONT WILL INCREASE WINDS ABOVE 20 KT 
DOWNWIND OF THE GULF OF TEHUANTEPEC BY MON MORNING.  FARTHER 
SOUTH...EXPECT THE INCREASED PRESSURE GRADIENT BETWEEN THE 
CLIMATOLOGICAL LOW PRESSURE OVER NORTHERN COLOMBIA AND THE 
BUILDING HIGH PRESSURE OVER THE WESTERN CARIBBEAN TO INCREASE 
NORTHERLY FLOW THROUGH PANAMA TOMORROW.

$$
SCHAUER CLARK