000
AXPZ20 KNHC 210405
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE MAR 21 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 
0400 UTC.

...ITCZ...
ITCZ AXIS IS ALONG 2N78W 3N95W 6N106W 3N130W 5N140W. NO 
SIGNIFICANT CONVECTION

...DISCUSSION...
W OF 100W...
RATHER PROGRESSIVE PATTERN UNDERWAY ACROSS THE AREA N OF 20N. 
SHEARED SHORTWAVE TROUGH EXTENDS FROM NRN MEXICO ACROSS SRN BAJA 
CALIFORNIA TO 19N125W. STRONG SUBSIDENCE NOTED AT THE SW END OF 
THE TROUGH FROM 18N TO 24N BETWEEN 110W AND 130W. SHORTWAVE 
RIDGE N OF 26N ALONG 105W WAS MOVING EWD 20-25 KT N OF THE 
TROUGH. RIDGE WAS IN ADVANCE OF ANOTHER SHORTWAVE WHICH EXTENDED 
FROM A WELL DEFINED CYCLONIC CIRCULATION OVER N-CENTRAL 
CALIFORNIA SWWD THROUGH 32N127W TO 28N135W. AXIS OF SUBTROPICAL 
JTST EXTENDED FROM 19N115W ENEWD THROUGH N-CENTRAL MEXICO INTO 
THE EXTREME NW GULF OF MEXICO AND CONTINUES TO ADVECT A 300 NM 
WIDE BAND OF TROPICAL MOISTURE INTO A LATE SEASON WINTER STORM 
OVER THE GREAT PLAINS AND TENNESSEE RIVER VALLEY OF THE U.S. 
CORE SPEEDS IN THE JET WERE 100 KT OVER MEXICO. WEAK ZONAL FLOW 
AND MODERATE SUBSIDENCE COVERED THE TROPICS S OF 12N. AT THE 
SURFACE COLD FRONT EXTENDED FROM 30N126W TO 27N140W AND WAS 
ADVANCING SE AT 10-15 KT...MAINLY E OF 130W. COLD FRONT WAS 
MARKED BY A 90-120 NM WIDE BAND OF BROKEN TO OVERCAST 
STRATOCUMULUS WITH POSSIBLE EMBEDDED SHOWERS.  

E OF 100W...
FLAT UPPER RIDGE DOMINATED THE AREA WITH AXIS ROUGHLY ALONG 88W. 
ZONAL FLOW OVER THE AREA WAS INCREASINGLY CONFLUENT OVER CENTRAL 
AMERICA AND THE W CARIBBEAN AND RESULTED IN STRONG SUBSIDENCE 
ALOFT OVER THE AREA...INHIBITING CONVECTION ALONG THE ITCZ.  
AXIS OF SUBTROPICAL JTST NOTED ABOVE WAS ADVECTING MID AND UPPER 
LEVEL MOISTURE OVER CENTRAL MEXICO AND THE ENTIRE GULF OF 
MEXICO.   

GAP WINDS...
0010 UTC QUIKSCAT...AS IN THE CASE OF LAST NIGHT...INDICATED 
WINDS HAD DROPPED TO 10-15 KT IN THE GULF OF PAPAGAYO. THESE 
WINDS APPEAR TO BE DIURNAL IN NATURE WITH MAXIMUM WINDS IN THE 
LATE MORNING AND AFTERNOON AND WEAKER WINDS AT NIGHT. 
HOWEVER...NWP MODELS INDICATE WINDS SHOULD REMAIN BELOW 20 KT BY 
24 HOURS.

$$
COBB