000
AXPZ20 KNHC 191552
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU FEB 19 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 
1545 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS 01N79W TO 05N95W TO 
03N103W TO 07N125W TO 05N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS NOTED WITHIN 90 NM OF AXIS BETWEEN 123W
AND 130W.

...DISCUSSION...
A DEEP LAYER TROUGH LIES OFF THE WESTERN UNITED STATES WITH A 
DEEP LAYERED CYCLONE CENTERED N OF THE DISCUSSION AREA NEAR 
36N136W...LIFTING NE AT THE MOMENT. AN ASSOCIATED SURFACE 
FRONT...THE FIRST OF A SERIES OF FRONTS THAT WILL ROTATE AROUND 
THE CYCLONE...EXTENDS S FROM 32N131W TO 25N140W. CONVECTION IS 
ENHANCED N OF THE AREA WHILE MULTI LEVEL CLOUDS AND LIGHT 
SHOWERS ARE NOTED WITHIN 90 NM W OF THE FRONT TO THE S OF 32N. 
STRONG SURFACE WINDS NOTED WITHIN 300 NM EITHER SIDE OF FRONT 
WHICH WILL PROPAGATE ANOTHER SERIES OF NW SWELLS INTO THE 
DISCUSSION AREA TODAY AND REINFORCED BY ANOTHER SURFACE FRONT 
FRI. 

AN UPPER LEVEL ANTICYCLONE IS NEAR 16N106W WITH A RIDGE NW 
CRESTING ALONG POINTS 19N134W TO 28N118W TO 30N104W. ANOTHER 
UPPER ANTICYLONE IS JUST S OF THE AREA AT 01S140W WITH ITS 
ENVELOPE OF ANTICYCLONIC FLOW NOTED OVER THE AREA S OF 18N W IF 
130W. UPPER DEBRIS MOISTURE...ORIGINATING FROM ITCZ CONVECTION 
W OF THE AREA BETWEEN 144W AND 165W...CONCENTRATES INTO AN UPPER 
MOISTURE PLUME ROUGHLY WITHIN 420 NM EITHER SIDE OF LINE 13N140W 
TO 20N120W THEN NARROWS AS IT CROSSES THE SOUTHERN BAJA 
PENINSULA AND CENTRAL OLD MEXICO AND THE NORTHERN GULF OF 
MEXICO...ALL ROUGHLY WITHIN 150 NM OF POINTS 23N113W TO 27N97W 
TO 29N81W. 

SOME DEBRIS MOISTURE IS NOTED ALONG THE PACIFIC COAST OF 
COLOMBIA. OTHERWISE THE UPPER LEVELS APPEAR VERY DRY S OF 23N E 
OF 110W. 

ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS FROM 32N120W TO 
21N138W AND BLOCKS THE EASTWARD PROGRESSION OF A SERIES OF COLD 
FRONT ROTATING AROUND THE DEEP LAYERED CYCLONE PREVIOUSLY 
MENTIONED. E OF THE RIDGE... NW WINDS IN THE GULF OF CALIFORNIA 
WILL PULSE AT 15 TO 20 KT...INCREASING TO 10 TO 25 KT JUST AFTER 
SUNRISE...THROUGH THE WEEKEND. 

CENTRAL AMERICAN GAPS...NORTHERLY WINDS S OF THE GULF OF PANAMA 
HAVE DIMINISHED TO 15 KT PER A EARLY MORNING QSCAT PASS. NE TO E 
WINDS IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO OF 20 TO 25 
KNOTS WILL INCREASE OVER THE NEXT SEVERAL DAYS. NORTHERLY WINDS 
WILL INCREASE TO 20 TO 25 KT LATE TONIGHT IN THE GULF OF 
TEHUANTEPEC...AND FURTHER INCREASE TO 20 TO 30 KNOTS AFTER 
SUNRISE FRI AND CONTINUE THROUGH 48 HOURS.

$$
NELSON