000
AXPZ20 KNHC 201013
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU APR 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N78W 6N90W 8N110W 5N120W 5N130W 
4N140W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS
BETWEEN 82W AND 84.5W. SCATTERED MODERATE CONVECTION IS WITHIN
60 NM OF THE AXIS BETWEEN 127W-130W. ISOLATED STRONG CONVECTION 
IS NORTH OF THE ITCZ WITHIN 30 NM OF 8N130W.

...DISCUSSION...
MID/UPPER LEVEL RIDGING IS SLIDING EASTWARD OVER THE AREA NORTH
OF 13N BETWEEN 118W-130W WITH MEAN RIDGE AXIS EXTENDING THROUGH
32N123W 21N123W TO 13N123W. AS THE RIDGE MOVES EASTWARD...THE
NEXT DEEP-LAYERED TROUGH CONTINUES ITS PROGRESS EASTWARD ACROSS
THE WESTERN PART OF THE AREA WEST OF THE MID/UPPER RIDGE. A MID/
UPPER LEVEL VORTEX NORTH OF THE AREA NEAR 33N138W IS SEEN 
DROPPING SOUTHEASTWARD TOWARDS THE DISCUSSION AREA...BUT IS 
STRETCHING NORTHEAST-SOUTHWEST WITH TIME. THE CORRESPONDING 
SURFACE COLD FRONT ENTERS THE AREA THROUGH 32N139W AND CONTINUES 
TO SOUTHWEST WEST OF THE AREA WHERE IT IS TRANSITIONING TO A 
SHEAR LINE. THERE IS LIMITED UPPER LEVEL DYNAMICS/LIFT WITH THE 
FRONT SO ONLY WIDELY SCATTERED TO LOCALLY SCATTERED SHOWERS ARE 
EXPECTED ALONG THE BOUNDARY. LATEST MODEL GUIDANCE INDICATES 
THAT THE FRONT WILL BE ACCOMPANIED BY AN INCREASE IN NORTHERLY 
WINDS TO 20-25 KT I ABOUT 24 HOURS WITH BUILDING SEAS POSSIBLY 
UP TO 13 FT. FURTHER E...MID/UPPER LEVEL TROUGH EXTENDS 
SOUTHWEST INTO THE EASTERN PACIFIC FROM CENTRAL MEXICO NEAR 
21N105.5W TO 14.5N110W TO 8N112W. SCATTERED MODERATE CONVECTION 
IS WITHIN 45 NM EITHER SIDE OF LINE 8N110W 10N106W. MODERATE TO 
STRONG SUBSIDENCE AND ASSOCIATED DRY AIR RESULTING IN STABLE 
CONDITIONS ARE NOTED EAST OF 120W INCLUDING MUCH OF MEXICO AND 
CENTRAL AMERICA.

AN UPPER LEVEL RIDGE EXTENDS FROM COLOMBIA NW ALONG CENTRAL 
AMERICA THEN N OVER THE GULF OF MEXICO. AT THE SURFACE...THE 
SUBTROPICAL RIDGE EXTENDS FROM A 1020 MB HIGH NEAR 35N130W 
SOUTHEASTWARD TO 20N115W. HIGH PRESSURE COVERS THE AREA NORTH
OF 15N WEST OF 115W. GLOBAL MODELS SUGGEST THAT THE RIDGE
WILL WEAKEN SOME OVER THE NEXT 24-48 HOURS AS THE AFOREMENTIONED 
COLD FRONT MOVES INTO THE AREA...AND ALLOW FOR THE TYPICAL
TRADES TO DECEASE OVER THE WESTERN PORTION OF THE AREA FRIDAY
THROUGH SUNDAY.

GAP WINDS...STRONG TRADES OVER THE WESTERN CARIBBEAN ARE EXPECTED
TO SPILL THROUGH INTO THE EASTERN PACIFIC IN ABOUT 48 HOURS 
ALLOWING FOR NE 20 KT WINDS TO BEGIN ACROSS THE GULF OF PAPAGAYO.

$$
AGUIRRE