000
AXPZ20 KNHC 200916
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU DEC 20 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 
0600 UTC.
 
...ITCZ...

INTERTROPICAL CONVERGENCE ZONE ALONG 9N84W 10N100 8N110W 9N140W. 
CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE 
WITHIN 90/120 NM OF THE AXIS FROM 104W-113W.

...DISCUSSION...
THE MID-LATITUDE UPPER LEVEL WESTERLIES ARE FAIRLY ZONAL AND 
PROGRESSIVE AT THE MOMENT...WITH VERY FEW TROUGH INTRUSIONS 
NOTED EXTENDING INTO THE DEEP TROPICS. STARTING IN THE EAST...A 
DOMINATING DEEP-LAYERED RIDGE COVERS MUCH OF THE AREA WITH THE 
UPPER RIDGE ALONG 13N/14N AND THE MID-LEVEL HIGH CENTERED OVER S 
MEXICO JUST S THE BAY OF CAMPECHE. DEEP EASTERLIES LIE S OF THIS 
RIDGE ACROSS THE TROPICS...EXTENDING FROM CENTRAL AMERICA TO 
ABOUT 115W AT THE EDGE OF THE RIDGE AXIS. N OF THE RIDGE... 
MID-LATITUDE FLOW IS LOCATED OVER N MEXICO WITH A 90/115 KT JET 
RUNNING ACROSS N MEXICO AND TEXAS TO ALONG THE N GULF OF MEXICO. 

FARTHER W...A SHORTWAVE TROUGH IS MOVING ACROSS ARIZONA INTO NEW 
MEXICO WITH ITS SOUTHERN EXTENSION ACROSS FAR NW MEXICO AND THE 
N BAJA PENINSULA THEN HANGING BACK TO 20N135W. THE TROUGH IS 
TAPPING INTO MOISTURE LOCATED OVER THE DEEP TROPICS AND IS 
PULLING IT NE ALONG THE SUBTROPICAL JET TO OVER MEXICO. FARTHER 
N...AN UPPER LEVEL HIGH IS LOCATED NEAR 27N136W AND IS HELPING 
TO PRODUCE AN AREA OF MODERATE/STRONG SUBSIDENCE N OF 20N W OF 
130W.

$$
WALLACE