000
AXPZ20 KNHC 110922
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE DEC 11 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...6N77W 9N105W 
6N120W 8N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF 
THE POINT 9N99W. SCATTERED MODERATE TO STRONG CONVECTION IS 
WITHIN 45 NM OF THE POINT 12.5N106.3W.

...DISCUSSION...
UPPER LEVELS...
STRONG SHORTWAVE TROUGH IS NORTH OF LINE 32N130W 12N120W 
25N105W. THE MOST INTENSE PART OF THE SHORTWAVE IS OVER BAJA 
CALIFORNIA AND NORTHWEST MEXICO. THE SHORTWAVE IS FORECAST TO 
MOVE EAST NORTHEAST AND BE ABSORBED IN THE WESTERLIES OVER THE 
UNITED STATES. THE AREA WITHIN THE SHORTWAVE IS DRY AND CLOUD 
FREE IN THE MIDDLE AND UPPER LEVELS. HOWEVER THE APPROACHING 
SHORTWAVE HAS INCREASED CONVECTIVE ACTIVITY IN THE ITCZ NEAR 
107W WHERE A WEAK LOW PRESSURE HAS DEVELOPED ALONG A TROUGH. THE 
SYSTEM IS MOVING WEST ABOUT 12 KNOTS AND IS EXPECTED TO CHANGE 
LITTLE THROUGH THE NEXT 48 HOURS THEN BEGIN TO WEAKEN. ALSO EAST 
OF THE TROUGH MIDDLE AND UPPER LEVEL MOISTURE AND BROKEN MULTI 
LEVEL CLOUDS ARE FLOWING NORTH OVER MEXICO FROM 100W TO 105W.

A TROUGH TO THE WEST OF THE AREA IS CAUSING MIDDLE AND UPPER 
LEVEL MOISTURE AND CLOUDS TO ADVECT NORTHWARD FROM ITCZ 
CONVECTION WEST OF THE AREA TO OVER THE AREA SOUTH OF 23N WEST 
OF 135W.

BROKEN TO OVERCAST STRATOCUMULUS CLOUDS COVER THE AREA NORTH OF 
16N WEST OF 120W AND ALSO SOUTH OF THE ITCZ EAST OF 125W.

REMAINDER OF THE AREA IS COVERED BY MIDDLE AND UPPER LEVEL 
RIDGE.

SURFACE...
MODERATE RIDGE IS NORTH OF THE ITCZ WEST OF LINE 20N105W THE THE 
ITCZ NEAR 115W. ELSEWHERE...EXCEPT FOR THE WEAK LOW PRESSURE...A 
BROAD TROUGH IS ANALYZED.

GAP WINDS...STRONG CARIBBEAN WINDS EXPECTED TO SURGE THROUGH THE 
GULF OF PAPAGAYO TO NEAR 9N94W THROUGH ABOUT 36 HOURS THEN 
DIMINISH. NLY DRAINAGE SURGES IN THE 15 KT RANGE ARE EXPECTED IN 
THE GULF OF TEHUANTEPEC JUST AFTER SUNRISE FOR THE NEXT FEW  
DAYS.  

$$
LL