000
AXPZ20 KNHC 191521
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED DEC 19 2007

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.
 
...ITCZ...

INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 5N77W 7N100W 
10N120W 7N140W. SCATTERED MODERATE CONVECTION FROM 6N-10N 
BETWEEN 99W-107W. SCATTERED MODERATE FROM 9N-13N BETWEEN 
109W-115W.

...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 15N/16N AND THE MID-LEVEL ANTICYCLONE CENTERED 
OVER THE BAY OF CAMPECHE. DEEP EASTERLIES LIE S OF THE RIDGE 
ACROSS THE TROPICS...EXTENDING FROM CENTRAL AMERICA TO ABOUT 
115W AT THE EDGE OF THE RIDGE AXIS. N OF THE RIDGE...QUICK 
MID-LATITUDE FLOW IS LOCATED OVER NORTHERN MEXICO WITH A 125 KT 
JET RUNNING ALONG THE U.S.-MEXICO BORDER.

FARTHER W...A SHORTWAVE TROUGH IS MOVING ACROSS UTAH AND ARIZONA 
WITH ITS SOUTHERN EXTENSION ACROSS FAR NW MEXICO THEN HANGING 
BACK TO 21N140W. THE TROUGH IS TAPPING INTO MOISTURE LOCATED 
OVER THE DEEP TROPICS NEAR HAWAII...AND IS PULLING IT NE INTO 
NORTHERN MEXICO ALONG THE SUBTROPICAL JET. A WEAK COLD FRONT IS 
ASSOCIATED WITH THE SHORTWAVE AND EXTENDS FROM NEAR SAN DIEGO 
CALIFORNIA SW TO 28N130W...BUT THIS BOUNDARY IS QUICKLY 
WEAKENING AS IT MOVES SE. WIDESPREAD CIRRUS IS NOTED OVER THE 
PACIFIC WATERS S OF ABOUT 25N...SPREADING ACROSS THE SOUTHERN 
BAJA PENINSULA AND THROUGH MEXICO N OF 25N. UPPER LEVEL WESTERLY 
FLOW LIES S OF THE TROUGH AXIS TO ABOUT 8N AND THEN TURNS 
NORTHERLY TOWARDS THE EQUATOR. FARTHER N...AN UPPER LEVEL HIGH 
IS LOCATED NEAR 27N139W AND IS HELPING TO PRODUCE AN AREA OF 
MODERATE/STRONG SUBSIDENCE N OF 20N W OF 127W.

$$
BERG