000
AXPZ20 KNHC 151517
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JAN 15 2011

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 6N86W 5N100W 8N115W 7N120W 7N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM N OF THE AXIS 
FROM 114W-119W AND WITHIN 120 NM N OF AXIS BETWEEN 135W-138W

...DISCUSSION...
UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTERED 
NEAR 29N126W TO 25N140W, MODERATE TO STRONG SUBSIDENCE WITH DRY 
STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS N OF 24N W OF 115W.
ANOTHER UPPER LEVEL CYCLONIC CIRCULATION IS ALONG THE FAR 
WESTERN PORTION OF THE AREA NEAR 18N40W. UPPER LEVEL DIFFLUENT 
FLOW SE OF THE CYCLONIC CIRCULATION IS ENHANCING CONVECTION 
ALONG THE ITCZ. AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED 
OVER NORTHERN BAJA CALIFORNIA NEAR 30N116W. DOWN STREAM UPPER 
LEVEL TROUGH OVER NORTHERN MEXICO FROM THE BIG BEND OF TEXAS SW 
TO THE SOUTHERN TIP OF THE BAJA PENINSULA.

IN THE DEEP TROPICS AN UPPER LEVEL RIDGE WITH AXIS FROM 12N114W 
TO 23N127W. A 70-75 KT JET STREAM FROM THE SOUTHERN HEMISPHERE
IS S OF A LINE FROM EQUATOR AT 130W TO 5N104W. MODERATE TO 
STRONG SUBSIDENCE IS S OF THE ITCZ E OF 125W.

A 1030 MB SURFACE HIGH PRES NEAR 32N133W WITH A RIDGE SE TO 
19N115W. TIGHT PRES GRADIENT ON THE SOUTHERN PERIPHERY OF THE 
RIDGE CONTINUES TO MAINTAIN A LARGE AREA OF NE TO E 20 TO 25 KT 
NE TRADE WINDS FROM GENERALLY 8N TO 25N W OF 120W. THE HIGH IS 
FORECAST TO MOVE N AND THE GRADIENT SHOULD LOOSEN ON SUN AND 
MON. A SURFACE TROUGH IS ANALYZED ALONG THE ITCZ FROM 10N113W TO
5N118W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 180 NM 
E OF THE TROUGH FROM 7N-10N. 

GALE FORCE WINDS CONTINUE IN THE GULF OF TEHUANTEPEC. THE WINDS 
ARE FORECAST TO DECREASE TO BELOW GALE FORCE LATER THIS 
AFTERNOON AS RETURN SE TO S FLOW SETS UP OVER THE WESTERN GULF 
OF MEXICO AND THE RESPONSIBLE AREA OF TIGHT PRES GRADIENT 
RELAXES OVER SOUTHERN MEXICO. ELY WINDS 20-25 KT THROUGH THE 
GULF OF PAPAGAYO WILL DECREASE TO BELOW 20 KT TONIGHT.

$$
DGS