000
AXPZ20 KNHC 301510
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU APR 30 2009

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...
AXIS IS ALONG 7N77W 6N85W 7N105W 6N120W 7N128W 6N140W. SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 140 NM S OF AXIS E OF 80W 
AND WITHIN 240 NM N OF AXIS FROM 117W-131W.

...DISCUSSION...
SHARP DEEP LAYER TROUGH WITH AXIS FROM 32N138W TO 18N140W. A 120 
KT JET STREAM IS NW OF THE TROUGH AXIS W OF THE DISCUSSION AREA. 
A WEAKER 85-95 KT JET IS E OF THE TROUGH AXIS FROM 13N140W TO 
32N123W. BROKEN/OVERCAST CIRRUS CLOUDS ARE WITHIN 400 NM SE OF 
THE JET. UPPER LEVEL RIDGE EXTENDS FROM SOUTHERN CALIFORNIA TO AN
ANTICYCLONIC CIRCULATION CENTERED NEAR 9N124W. DIFFLUENT UPPER 
FLOW WITH THE ANTICYCLONIC CIRCULATION IS ENHANCING A LARGE AREA
OF CONVECTION N OF THE ITCZ DESCRIBED ABOVE. 

ANOTHER UPPER TROUGH IS OVER THE EASTERN PORTION OF THE AREA 
WITH AXIS FROM THE BAY OF CAMPECHE ACROSS SOUTHERN MEXICO TO 
11N96W TO 5N105W. TO THE E OF THE TROUGH AXIS THE SLY FLOW IS 
ADVECTING DEEP LAYER MOISTURE WITH MULTI LEVEL BROKEN CLOUDS 
FROM ITCZ CONVECTION TO OVER CENTRAL AMERICA AND SOUTHERN 
MEXICO. A BROAD UPPER LEVEL RIDGE IS E OF 90W.

A COUPLE OF SURFACE TROUGHS ARE ANALYZED ALONG THE ITCZ. THE 
FIRST IS FROM 11N88W TO 6N87W. SCATTERED SHOWERS ARE FROM 6N-12N
BETWEEN 86W-93W. THE SECOND TROUGH EXTENDS FROM 12N127W TO 
4N130W. SCATTERED SHOWERS AND TSTMS ARE FROM 8N-12N BETWEEN
127W-131W.

DISSIPATING COLD FRONT ENTERS THE AREA NEAR 32N135W TO 21N140W.
OVERCAST MULTI-LAYERED CLOUDS WITH SCATTERED SHOWERS ARE WITHIN
240 NM E OF FRONT N OF 24N. ELSEWHERE A 1024 MB SURFACE HIGH 
PRES CENTER NEAR 32N125W WITH RIDGE COVERING THE AREA N OF 15N 
BETWEEN THE FRONT AND THE BAJA PENINSULA. NE TO E WINDS CONTINUE 
TO BLOW THROUGH THE GULF OF PAPAGAYO BUT SHOULD DECREASE FRI.

$$
DGS