000
AXPZ20 KNHC 180929
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED OCT 18 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 
0900 UTC.

...TROPICAL WAVES...
NONE.

...ITCZ...
AXIS 11N86W 14N98W 12N110W 8N128W 9N140W. SCATTERED MODERATE STRONG 
CONVECTION WITHIN 180 NM OF 8N187W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WITHIN 100 NM OF AXIS BETWEEN 88W AND 126W.

...DISCUSSION...
MID/UPPER LEVEL TROUGH PATTERN CONTINUES TO SIT OVER THE WESTERN U.S.
WITH A FEW SHORT WAVES ROTATING AROUND THE BASE ACROSS THE N PART OF 
THE DISCUSSION AREA. ONE SHORTWAVE TROUGH EXTENDS FROM THE NRN GULF 
OF CALIFORNIA S TO 16N115W AND IS ACCOMPANIED BY AN AREA OF STRONG 
SUBSIDENCE EXTENDING UP TO 750 NM SW OF THE BAJA PENINSULA. A SECOND 
BROADER SHORTWAVE EXTENDING FROM 30N122W TO 19N135W IS ADVECTING MORE
DRY AIR INTO THE AREA. THESE SHORTWAVES ARE HELPING TO PUSH A DYING 
COLD FRONT SWD FROM CENTRAL BAJA W TO 25N126W TO 28N136W WITH A WEAK 
WIND SURGE AND A BAND OF STRATOCUMULUS IN ITS WAKE.

AN UPPER RIDGE AXIS ANCHORED IN THE GULF OF MEXICO EXTENDS SW ACROSS 
MEXICO TO NEAR 10N121W AND MARKS A DIVIDING LINE BETWEEN DRY AIR TO 
THE NW AND MOIST AIR TO THE SE. LOW-LEVEL CONVERGENCE ALONG THE ITCZ 
IS PRODUCING CLUSTERS OF DEEP CONVECTION ACROSS MOST OF ITS LENGTH 
AND THE RIDGE IS ENHANCING WIDESPREAD COVERAGE. STRONG NE UPPER LEVEL
WINDS ARE DIVERGENT S OF CENTRAL AMERICA...PRODUCING STRONGLY SHEARED
ACTIVE CONVECTION...PRIMARILY BETWEEN 85W AND 92W.

$$
MUNDELL