000
AXPZ20 KNHC 202147
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU MAR 20 2008

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG...3N78W 4N88W 4N95W 5N105W 6N110W
5N117W 6N129W 6N140W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION EXISTS FROM 4N-7N BETWEEN 109W-116W...AND FROM 5N-7N 
BETWEEN 120W-127W.

...DISCUSSION...

DEEP LAYER TROUGH CUTS THROUGH THE FAR NW CORNER OF THE AREA 
NEAR 30N139W AND EXTENDS SW TO A MID/UPPER LEVEL LOW MOVING ENE 
15 KT NEAR 22N143W...AND CONTINUES S TO NEAR 10N148W. EXTENSIVE 
MID/UPPER LEVEL MOISTURE IS STREAMING ENE AHEAD OF THE TROUGH 
REACHING TO 126W WHERE A MID/UPPER LEVEL RIDGE IS IDENTIFIED ON 
WATER VAPOR IMAGERY. THE UPPER LEVEL FLOW BECOMES DIFFLUENT TO 
THE SE OF THE TROUGH AND S OF RIDGE ENHANCING ITCZ CONVECTION 
BETWEEN 117W-131W.

ANOTHER DEEP LAYER TROUGH EXTENDS SW FROM MID-WEST PORTION OF
THE U.S. SW THROUGH NW MEXICO AND THROUGH 19N109W TO 14N112W. 
THE TROUGH EARLIER PRODUCED WIDELY SCATTERED SHOWERS NEAR A 
STATIONARY SURFACE TROUGH FROM 13N101W TO 6N105W. CONFLUENT FLOW 
INTO THE BACK SIDE OF THIS TROUGH IS RESULTING IN AMPLE MODERATE 
TO STRONG SUBSIDENCE N OF 15N E OF 120W WHERE SKIES ARE NOTED AS 
MOSTLY CLEAR WITH ONLY SCATTERED TO BROKEN STRATOCUMULUS CLOUDS 
MOVING WSW FROM 12N-19N BETWEEN 112W-123W. A SUBTROPICAL JET 
STREAM ROUNDS THE BASE OF THE TROUGH EXTENDING FROM 12N112W NE 
THROUGH 15N107W TO ACROSS CENTRAL MEXICO AT 20N100W. THE JET 
CONTINUES TO ADVECT EXTENSIVE HIGH LEVEL MOISTURE NEWD ACROSS 
MEXICO...AND OVER MUCH OF THE GULF OF MEXICO SE OF A LINE FROM 
SE LOUISIANA TO TAMPICO MEXICO. MID/UPPER LEVEL RIDGING IS 
PRESENT S OF 8N BETWEEN 90W-105W. A MID LEVEL TROUGH IS ALONG 
85W S OF 5N. MID/UPPER LEVEL RIDGING EXTENDS FROM NW COLOMBIA NW 
ACROSS CENTRAL AMERICA TO AN ANTICYCLONIC CENTER AND TO OVER THE 
GULF OF HONDURAS. 

AT THE SURFACE...
A RIDGE ENTERS THE REGION AT 32N129W AND STRETCHES SE TO 
21N116W. HIGH PRES COVERS THE AREA N OF 14N W OF 112W. THE PRES 
GRADIENT ASSOCIATED WITH THE RIDGE IS PRODUCING NE-E WINDS IN 
THE RANGE OF 20-25 KT FROM 8N-28N W OF 130W...AND ALSO FROM 
7N-18N BETWEEN 118W-130W.
 
GAP NE-E WINDS TO 20 KT IN THE GULF OF PAPAGAYO AREA WILL 
INCREASE
TO 20-25 KT IN 24 HOURS AND LAST THROUGH SAT AFTERNOON.

A TIGHT PRES GRADIENT OVER SE MEXICO IS RESULTING IN GALE
FORCE WINDS IN THE GULF OF TEHUANTEPEC. A MORNING QUIKSCAT PASS
SHOWED MOSTLY GALE FORCE WINDS UP TO 45 WITH THE HI-RES PASS
SHOWING UP TO 50 KT FOR A POSSIBLE BRIEF INSTANCE. MODEL GUIDANCE
IS SUGGESTING THAT THE GRADIENT WEAKENS RATHER QUICKLY ON FRI 
ALLOWING
FOR WINDS TO DROP TO BELOW GALE FORCE.

$$
AGUIRRE