000
AXPZ20 KNHC 181520
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU APR 18 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH 9N85W 4N115W TO 5N120W. ITCZ 5N124W TO 3N140W.
SCATTERED MODERATE TO STRONG CONVECTION N OF 3N E OF 84W
AND WITHIN 200 NM S OF AXIS FROM 90W-93W AND WITHIN 200 NM N
OF AXIS FROM 98W-101W.

...DISCUSSION... 
AN UPPER  LEVEL CYCLONIC CIRCULATION IS LOCATED OVER THE FAR
NW PORTION OF THE DISCUSSION AREA CENTERED NEAR 29N140W.
MODERATE TO STRONG SUBSIDENCE WITH DRY AND STABLE AIR AT THE
MIDDLE AND UPPER LEVELS N OF 25N BETWEEN 115W-130W. AN UPPER
LEVEL RIDGE EXTENDS FROM AN ANTICYCLONIC CIRCULATION NEAR
18N108W TO 32N132W WITH ANOTHER RIDGE EXTENDING WESTWARD
INTO MEXICO. ANTICYCLONIC FLOW COVERS OF THE AREA S OF 30N
E OF 135W. A 95-110 KT JETSTREAM BETWEEN THE ANTICYCLONE
AND AN UPPER LEVEL TROUGH OVER THE ROCKIES EXTENDS FROM
25N120W NORTHERN MEXICO WHERE WINDS INCREASE TO 130 KT.

SURFACE TROUGH EXTENDS FROM 12N-5N ALONG 122W. SCATTERED
MODERATE TO STRONG IS FROM 10N-12N WITHIN 150 NM W OF THE
TROUGH.

LATE SEASON COLD FRONT IS FORECAST TO MOVE THROUGH THE GULF
OF MEXICO FRI. STRONG HIGH PRES WILL BUILD SOUTH BEHIND THE
FRONT TIGHTENING THE GRADIENT OVER SOUTHERN MEXICO RESULTING
GALE FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC FRI NIGHT
AND SAT.

$$
DGS