000
AXPZ20 KNHC 022158
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN APR 02 2006

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 2145 UTC.

...ITCZ...
ITCZ AXIS ALONG AXIS 3N78W 5N92W 4N129W 3N140W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 90 NM OF AXIS FROM 88W TO 120W 
AND WITHIN 60 NM OF 6N126W AND 10N128W ASSOCIATED WITH A TROUGH 
AXIS.

...DISCUSSION...
THE NE PAC IS DOMINATED BY A LONGWAVE TROUGH WITH AN EMBEDDED  
DEEP LAYERED CYCLONE NEAR 45N135W. A SHORTWAVE TROUGH IS 
SWINGING SE ALONG 34N135W 26N145W ATTM ACCOMPANIED BY A BAND OF 
DRY UPPER AIR WITHIN 30 NM OF ITS AXIS. ANOTHER SHORTWAVE TROUGH 
OVER THE CENTRAL CONUS EXTENDS SW INTO THE DISCUSSION AREA FROM 
32N103W TO A BASE NEAR 22N109W. AN UPPER CYCLONE HAS CUTOFF AS 
EXPECTED NEAR 4N118W. SQUEEZED BETWEEN THESE TROUGHS...AN 
EMBEDDED SHORTWAVE RIDGE ORIGINATES FROM AN ANTICYCLONE NEAR 
2N163W...AND EXTENDS NE INTO THE AREA ALONG 17N140W 27N120W TO 
AN AMPLIFYING CREST OVER NEVADA NEAR 40N117W. 

A DEEP LAYERED TROUGH HAS DEVELOPED S OF 15N ALONG 130W WITH 
UPPER DIFFLUENCE NOTED ON LATEST CLOUD MOTION VECTORS. 
CONVECTION IS FLARING WITHIN 120 NM E OF THE ASSOCIATED LOW 
LEVEL TROUGH...EXTENDING FROM 3N TO 13N ALONG 130W...AND ALONG 
THE ITCZ BETWEEN 125W AND 110W. THE RESULTANT DEBRIS MOISTURE IS 
SPREADING NE TO NEAR 16N115W THEN EVAPORATES. BUT AN INTENSE 
MOISTURE PLUME THAT BEGINS NEAR THE ANTICYCLONE AT 2N163W LIES 
ALONG THE SHORTWAVE RIDGE AXIS AND CONTINUES ACROSS NW OLD 
MEXICO AND SOUTHERN CALIFORNIA INTO THE WESTERN CONUS. 

A BAND OF DRY AIR IS NOTED WITHIN THE SHORTWAVE TROUGH OVER OLD 
MEXICO...ROUGHLY TO THE N OF 23N BETWEEN 115W AND 100W...AND IS 
SHIFTING E WITH TIME. 

UPPER ANTICYCLONES IS CENTERED OVER N COLOMBIA AND N VENEZUELA 
WITH A COLLAPSING RIDGE EXTENDING NW ACROSS THE W CARIBBEAN 
WHERE THE UPPER FLOW HAS BECOME ZONAL. ANOTHER UPPER ANTICYCLONE
IS ESTIMATED NEAR 5N92W WITH A RIDGE EXTENDING NNE ACROSS THE W 
GULF OF MEXICO AND CONTINUING NE ACROSS THE SE CONUS. UPPER 
DIFFLUENCE UNDER THIS RIDGE IS ENHANCING CONVECTION ALONG THE 
ITCZ E OF 110W. THE RESULTANT UPPER DEBRIS MOISTURE IS SPREADING 
NE ACROSS CENTRAL AMERICA AND MERGING INTO THE ZONAL UPPER FLOW 
DOMINATING MOST OF THE CARIBBEAN. OTHERWISE DRY UPPER AIR 
DOMINATES THE DISCUSSION N OF THE ITCZ E OF 110W.

AT THE SURFACE...HIGH PRES 1023 MB IS QUASI STATIONARY NEAR 
28N120W AND IS BLOCKING A WEAKENING FRONTAL TROUGH THAT LIES 
ALONG 32N125W 21N133W. THE APPROACHING UPPER TROUGH HAS A 
SURFACE COLD FRONT ALONG 32N132W 28N140W THAT WILL BRING ANOTHER 
TRAIN OF NW SWELLS INTO THE DISCUSSION AREA.  

GULF OF PAPAGAYO...LATEST SSMI DATA INDICATE NE WINDS 20 KT 
WITHIN 60 NM EITHER SIDE LINE 8N94W 11N87W. MODEL GUIDANCE 
FLUCTUATES NE 20 KT WINDS THROUGH 48 HOURS. 

$$
NELSON