000
AXPZ20 KNHC 122149
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT MAR 12 2011

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 
2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 1014 MB 
LOW PRES NEAR 01N94W TO 02N100W TO 06N120W TO 06N130W TO 
06N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM N 
OF AXIS W OF 130W.

...DISCUSSION...
A DEEP-LAYER TROUGH EXTENDS FROM 30N130W TO 23N140W. THIS TROUGH 
IS SUPPORTING A STRONG COLD FRONT CURRENTLY LOCATED NW OF THE 
AREA THAT WILL BE APPROACHING TO 30N140W EARLY SUN MORNING. SW 
WINDS OF 20 KT WILL AFFECT THE FAR NW PORTION OF THE AREA 
TONIGHT AND SUN. TO THE E OF THE TROUGH...THERE IS A BROAD UPPER 
LEVEL RIDGE THAT DOMINATES THE MAJORITY OF THE AREA N OF 7N W OF 
110W. UPPER LEVEL DIVERGENCE ON THE W PORTIONS OF THE RIDGE IS 
HELPING TO INDUCE CONVECTION ALONG THE ITCZ AS DESCRIBED ABOVE. 
A WEST TO EAST TROUGH LIES N OF THE EQUATOR AND STRETCHES FROM 
AN UPPER LEVEL LOW NEAR 3N140W TO NEAR 6N117W. SW FLOW BETWEEN 
THE RIDGE AND THE FIRST UPPER LEVEL TROUGH CONTINUES TO 
TRANSPORT ABUNDANT MOISTURE FROM THE CENTRAL TROPICAL PACIFIC S 
OF THE HAWAIIAN ISLANDS TO THE CREST AND OVER THE TOP OF THE 
RIDGE TO ACROSS BAJA CALIFORNIA...NW MEXICO AND THE SW CONUS. 

ELSEWHERE AT THE SURFACE...A 1025 MB HIGH PRES IS POSITIONED 
NEAR 29N126 WITH RIDGING EXTENDING SE FROM THE HIGH TO NEAR 
20N110W. THE ASSOCIATED UPPER LEVEL RIDGING E OF 140W CONTINUES 
TO BLOCK FRONTAL SYSTEMS FROM ENTERING THE AREA FROM THE W-NW. 
AS THE NEXT ABOVE MENTIONED FRONTAL SYSTEM APPROACHES THE AREA 
THE HIGH IS BEING NUDGED SLIGHTLY E-SE...INCREASING THE PRES 
GRADIENT BETWEEN THE HIGH AND LOWER PRES E OF THE U.S. ROCKY 
MOUNTAINS AND THE SIERRA MADRE OCCIDENTALS. THIS HAS ALREADY  
RESULTED IN NW-N 20 KT WINDS WITHIN AROUND 180 NM OF THE W COAST 
OF BAJA CALIFORNIA. THESE WINDS ARE EXPECTED TO PERSIST DURING 
THE NEXT 48 HOURS.

AN AREA OF FRESH TRADE WINDS IS ALSO NOTED ON THE SOUTHERN 
PERIPHERY OF THE RIDGE COVERING ROUGHLY THE AREA FROM 7N TO 15N 
AND W OF 125W. THIS WEATHER PATTERN WILL PERSIST OVER THE NEXT 
COUPLE OF DAYS. 

GAP WINDS...
GULF OF TEHUANTEPEC...WINDS CONTINUE TO DIMINISH THROUGH THE 
GULF OF TEHUANTEPEC AS WINDS VEER TO THE SE AND S ACROSS THE 
GULF OF MEXICO. WINDS WILL GRADUALLY DIMINISH TO LESS THAN 20 KT 
DURING THE NEXT 24 HOURS. A WINDSAT PASS FROM THIS MORNING 
SHOWED NE WINDS OF 20 KT EXTENDING DOWNSTREAM TO NEAR 13N97W.

GULF OF PAPAGAYO...NE TO E WINDS OF 20 KT WILL CONTINUE TO BLOW 
ACROSS THE GULF OF PAPAGAYO DURING THE NEXT COUPLE OF DAYS. THE 
1516 ASCAT PASS VERIFIED THESE WIND SPEEDS. 

GULF OF PANAMA...LATEST MODEL GUIDANCE CONTINUES TO INDICATE 20 
KT NORTHERLY WINDS IN THE GULF OF PANAMA AS THE PRES GRADIENT 
HAS TIGHTENED OVER WESTERN COLOMBIA. THESE WINDS ARE EXPECTED TO 
PERSIST THROUGH THE NEXT 24-36 HOURS.

$$
GR