000
AXPZ20 KNHC 171520
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON APR 17 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
ITCZ AXIS IS ALONG 6N78W 7N90W 7N105W 8N120W 7N130W 7N140W. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 90 NM OF THE 
AXIS FROM 128W-138W. ISOLATED MODERATE CONVECTION IS WITHIN 30 
NM OF THE AXIS FROM 90W-98W AND WITHIN 120 NM OF THE AXIS 
BETWEEN 115W-126W.

...DISCUSSION...
BROAD AND WEAK MID/UPPER LEVEL TROUGH THAT IS LIFTING NE AWAY 
FROM THE AREA...CURRENTLY REMAINS OVER THE AREA N OF 24N E OF 
135W. THE TROUGH WILL BE REPLACED BY WESTERLY ZONAL FLOW ACROSS 
THE N PORTION OF THE AREA IN THE NEXT 12-24 HOURS. DRY AIR AND 
SUBSIDENCE COVERS THE AREA NW OF LINE 20N240W 21N127W 29N112W. 
PLUME OF MID/HIGH LEVEL MOISTURE IS SEEN STREAMING NEWD IN THE 
SWLY FLOW SE OF THE TROUGH. THE MOISTURE IS BEING ADVECTED 
ACROSS THE SOUTHERN BAJA PENINSULA AND ACROSS CENTRAL MEXICO. 
THE COLD FRONT ASSOCIATED WITH THE TROUGH HAS DISSIPATED OVER 
THE PACIFIC WATERS WITH HIGH PRESSURE NOW BUILDING ACROSS THE 
REGION N OF THE ITCZ W OF 110W. THE HIGH IS PRODUCING SOME 20 KT 
NWLY WINDS ALONG THE W COAST OF BAJA PENINSULA AND 20-25 KT 
TRADES N OF THE ITCZ TO ABOUT 20N.

BROAD WEAK UPPER LEVEL RIDGING AND ANTICYCLONIC FLOW IS SEEN 
SOUTH OF 18N WEST OF ABOUT 125W. THIS RIDGE IS FORECAST TO 
BUILD A LITTLE NORTHWARD DURING THE NEXT 24 HOURS. AN AREA OF 
DIFLUENT FLOW OVER THE ITCZ IS HELPING TO PRODUCE SCATTERED 
CONVECTION ALONG THE AXIS W OF ABOUT 120W. 

FARTHER EAST...A LARGE MID/UPPER LEVEL LOW IS CENTERED OVER 
MEXICO NEAR 21N99W. TROUGH EXTENDS SOUTHWARD FROM THE 
CIRCULATION NEAR ACAPULCO TO 10N108W. THE UPPER LEVEL LOW IS 
FORECAST TO SHEAR OUT AS IT MOVES NORTHWARD OVER MEXICO. WEAK 
TROUGH IS FORECAST TO LINGER ACROSS THE PACIFIC WATERS BETWEEN 
102W AND 108W.

EAST OF THE TROUGH THE FLOW IS SE TO SLY AROUND A LARGE MID AND 
UPPER LEVEL HIGH THAT IS CENTERED OVER THE SW CARIBBEAN SEA JUST 
SE OF THE ISLAND OF SAN ANDRES. THE TROPICAL PACIFIC BETWEEN 85W 
AND 110W IS COVERED BY DRY AIR/SUBSIDENCE. SOME HIGH LEVEL 
MOISTURE IS BEING ADVECTED FROM SOUTH AMERICA NWWD INTO THE 
PACIFIC E OF 85W.  A LINE OF VERY THIN CIRRUS CLOUDS THAT HAVE
A RATHER MILKY APPEARANCE IN IR SATELLITE IMAGERY IS SEEN FROM 
THE PACIFIC NORTHWARD ACROSS COAST RICA AND NICARAGUA.
 
$$
BROWN