000
AXPZ20 KNHC 202121
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAR 20 2007

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2100 UTC.

...ITCZ...

ITCZ IS CENTERED ALONG...7N77W 4N113W 6N132W 4N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM EITHER 
SIDE OF LINE 5.5N91W 5N101W AND WITHIN 150 NM EITHER SIDE OF 
LINE 5N123W 6N136W. 

...DISCUSSION...

A COUPLE OF MID TO UPPER LEVEL TROUGHS ENTER THE NW PORTION OF 
THE DISCUSSION AREA WITH THE MEAN AXIS ALONG 32N124W 23N140W. A 
THIS BAND OF MOISTURE LIES BETWEEN THE TROUGHS WITHIN 60 NM 
EITHER SIDE OF LINE 31N124W 25N136W...OTHERWISE DRY UPPER AIR IS 
NOTED NW OF LINE 18N140W 30N118W. 

AN UPPER LEVEL ANTICYCLONE IS NEAR 3N123W WITH ITS ENVELOPE OF 
ANTICYCLONIC FLOW DOMINATING THE REMAINDER OF THE AREA W OF 
102W. ANOTHER UPPER TROUGH EXTENDS SW ACROSS THE E PORTION OF 
THE AREA...ROUGHLY ALONG 22N92W 6N106W. A MOISTURE PLUME... 
ORIGINATING FROM ITCZ CONVECTION BETWEEN 137W AND 155W...LIES 
ALONG THE W PERIPHERY OF THE UPPER RIDGE...WITHIN 300 NM EITHER 
SIDE OF LINE FROM 8N145W TO BEYOND 32N112W. DRY UPPER AIR IS 
TRAPPED ELSEWHERE UNDER THE UPPER RIDGE AND EXTENDS E ACROSS THE 
REMAINDER OF THE DISCUSSION AREA. 

AT THE SURFACE...A RIDGE EXTENDS SE INTO THE AREA ALONG 32N142W 
20N105W. A DISSIPATING COLD FRONT LIES ALONG 32N123W 22N136W 
ACCOMPANIED BY SCATTERED TO LOCALLY BROKEN LOW CLOUDS AND 
ISOLATED SHOWERS ROUGHLY WITHIN 90 NM NW OF THE FRONT.

GAP WINDS...SURFACE OBSERVATIONS REPORT N WINDS AT 20 KT 
SURROUNDING THE GULF OF TEHUANTEPEC AND HIGH RESOLUTION MODELS 
SUGGEST NLY SURGES 20 TO 25 KT THROUGH 48 HOURS...SO INTRODUCED 
INTO AFTERNOON HIGH SEAS PACKAGE. TIGHT PRES GRADIENT OVER THE W 
CARIBBEAN IS SPILLING ACROSS CENTRAL AMERICA AT 20-25 KT INTO 
AND DOWNSTREAM OF THE GULF OF PAPAGAYO. LATEST MODEL GUIDANCE 
INDICATES LITTLE CHANGE THROUGH AT LEAST 48 HOURS.

$$
NELSON