000
AXPZ20 KNHC 180331
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON DEC 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0330 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N78W 8N100W 8N112W 7N125W 
6N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ALONG 
THE AXIS W OF 124W. A CLUSTER OF SIMILAR CONVECTION IS NEAR 
8.5N117W.

...DISCUSSION...
A DEEP LAYERED TROUGH EXTENDS OVER THE NW PORTION OF THE AREA N 
OF 15 N W OF 110W. A JET STREAM LIES JUST AHEAD OF THE TROUGH 
ALONG 20N130W 25N120W...ENTERING THE SW U.S. THROUGH NORTHERN 
BAJA PENINSULA. SATELLITE DERIVED WINDS INDICATED THAT CORE 
SPEEDS ARE BETWEEN 90 AND 120 KT OVER THE DISCUSSION AREA. 
MID TO UPPER LEVEL TROUGH EXTENDS FROM W-CENTRAL MEXICO SWWD 
INTO THE PACIFIC NEAR 10N103W. A SUBTROPICAL JETSTREAM IS NOTED 
E OF THE TROUGH FROM 8N103W TO THE MEXICAN COAST NEAR 18N100W 
THEN EWD INTO THE GULF OF MEXICO...WITH WINDS TO NEAR 60 KT. 
THESE WINDS ARE ADVECTING ABUNDANT UPPER LEVEL MOISTURE THROUGH 
SOUTH-CENTRAL MEXICO INTO THE GULF OF MEXICO. MODERATE TO STRONG 
SUBSIDENCE WITH DRY AIR AT THE MID/UPPER LEVELS OF THE 
ATMOSPHERE IS OVER THE NW PORTION OF THE AREA AND ACROSS 
NORTHERN MEXICO. IN BETWEEN THESE TROUGHS THERE IS A BROAD AND 
FLAT RIDGE. ANOTHER UPPER LEVEL RIDGE COVERS THE E PACIFIC E OF 
100W...SUPPRESSING CONVECTION ALONG THE ITCZ IN THIS REGION.  

AT THE SURFACE...
A 1030 MB SFC HIGH PRES IS CENTERED NEAR 34N136W RIDGING SE TO 
NEAR 20N110W GENERATING STRONG NE WINDS AND HIGHEST SEAS TO 17 
FT. A DYING COLD FRONT CROSSES NW MEXICO AND CENTRAL BAJA 
PENINSULA THEN CONTINUES MAINLY SWWD ALONG 23N123W 16N140W. A 
NARROW BAND OF MAINLY LOW CLOUDS WITH EMBEDDED SHOWERS IS 
ASSOCIATED WITH THE FRONT. BROKEN COLD AIR STRATOCUMULUS CLOUDS 
ARE JUST BEHIND THE FRONTAL BOUNDARY COVERING THE NW CORNER OF 
THE DISCUSSION AREA. A 1010 MB SFC LOW PRES IS ALONG THE ITCZ 
NEAR 7N119W. LATEST SATELLITE IMAGERY IS STILL SHOWING A SWIRL 
OF LOW LEVEL CLOUDS ASSOCIATED WITH THIS LOW THAT IS MOVING WWD 
AT 10 TO 15 KT. A COUPLE OF CLUSTERS WITH MODERATE TO ISOLATED 
STRONG CONVECTION ARE WITHIN 60 NM NE AND S OF THE LOW LEVEL 
CENTER.   A SFC TROUGH EXTENDS FROM 14N105W TO 6N108W. ANOTHER 
SWIRL OF LOW LEVEL CLOUDS IS ASSOCIATED WITH THIS SFC TROUGH.  

GAP WINDS...NLY WIND TO 20 KT PRESENTLY IN GULF OF TEHUANTEPEC 
EXPECTED TO LAST FOR ABOUT 48 HOURS. ENE WINDS TO 20 KT IN THE 
GULF OF PAPAGAYO EXPECTED TO SPREAD W AND INCREASE TO 20 TO 25 
KT MON THEN BEGIN TO WEAKEN TUE.

$$
GR