000
AXPZ20 KNHC 102212
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU MAR 10 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 
2030 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 05N78W 
TO 03N90W TO 05N110W TO 05N120W TO 03N130W TO 04N140W. ISOLATED 
MODERATE WITHIN60 NM OF THE AXIS BETWEEN 78W AND 95W...AND 
WITHIN 90 NM OF THE AXIS BETWEEN 122W AND 140W.

...DISCUSSION...

IN THE UPPER LEVELS...BROAD RIDGING IS N OF 10N BETWEEN 95W AND 
125W. UPPER RIDGING IS OCCURRING OVER THE ITCZ BETWEEN 125W AND 
145W IN RESPONSE TO DIVERGENCE ALOFT INDUCED BY PULSING DEEP 
ITCZ CONVECTION. SWLY UPPER LEVEL FLOW W OF THE RIDGE AND N OF 
THE ITCZ IS TRANSPORTING ABUNDANT MOISTURE FROM THE CENTRAL 
TROPICAL PACIFIC TO THE CREST OF THE RIDGE AND INTO BAJA 
CALIFORNIA. A FEW SUBTLE SHORTWAVES WERE NOTED IN THIS SWLY FLOW 
ALOFT...WITH THE MOST SIGNIFICANT N OF 17N ALONG 132W. IS W OF 
THE AXIS N OF 15N W OF 115W. SUBSIDENCE DOMINATES THE NE 
QUADRANT OF THE BROAD UPPER RIDGE AND EXTENDS NE INTO MEXICO AND 
E INTO THE TROPICAL EPAC N OF THE ITCZ TO 88W. 

AT THE SURFACE...A WEAK COLD FRONT HAS ENTERED THE NW PORTION OF 
THE FORECAST AREA FROM 30N135W TO 28N140W. THE UPPER SUPPORT FOR 
THIS FRONT IS RACING EAST NORTHEASTWARD INTO THE U.S. W COAST 
WHILE THE PORTION OVER THE FORECAST AREA WEAKENS AS IT IS FORCED 
AGAINST THE PERSISTENT UPPER RIDGE OVER THE NE PORTION OF THE 
FORECAST AREA...INCLUDING NW MEXICO. AN INCREASED PRES GRADIENT 
BETWEEN HIGH PRES BEHIND THIS FRONT AND LOWER PRES E OF THE 
ROCKIES AND SIERRA MADRE OCCIDENTAL ASSOCIATED WITH THE FRONT 
WILL BRING NW WINDS TO 20 KT OFF THE COAST OF BAJA CALIFORNIA 
SUR OVERNIGHT FRI MORNING. WINDS ARE CURRENTLY BELOW ADVISORY 
CRITERIA NEAR THE FRONT...BUT NW SWELL BEHIND THE FRONT HAS 
BROUGHT SEAS TO 14 FT THIS AFTERNOON ACROSS FAR NW PORTIONS.

FRESH TRADE WINDS CURRENTLY LIE FROM 06N TO 15N W OF 130W. THIS 
AREA OF 20 KT TRADE WINDS IS EXPECTED TO SHRINK AND SHIFT 
WESTWARD FOR THE NEXT 24 HOURS THEN BE REPLACED WITH NW SWELL 
FROM THE COLD FRONT IN 48 HOURS. 

GAP WINDS...

GULF OF TEHUANTEPEC...A STRONG COLD FRONT SWEEPING THROUGH THE 
WESTERN GULF OF MEXICO TODAY HAS REACHED THE SOUTHERN GULF AND 
BLASTED COOL AIR THROUGH THE ISTHMUS OF TEHUANTEPEC. WINDS 
FUNNELING THROUGH THE CHIVELAS PASS AND ACROSS THE GULF OF 
TEHUANTEPEC INCREASED TO GALE FORCE LATE THIS MORNING AND WERE 
ESTIMATED AT 40 KT AT 1800 UTC...AND ARE EXPECTED TO REACH 45 KT 
BY THIS EVENING WITH SEAS AS HIGH AS 18 FT. WINDS ARE EXPECTED 
TO DIMINISH BELOW GALE FORCE BY FRI EVENING AS THE HIGH PRES 
OVER THE GULF BEHIND THE COLD FRONT BECOMES DISPLACED EASTWARD 
BY THE NEXT FRONT ENTERING THE SOUTHERN PLAINS.

GULF OF PAPAGAYO...AS THE GULF OF MEXICO COLD FRONT CONTINUES TO 
MOVE SOUTHEASTWARD INTO THE WESTERN CARIBBEAN...WINDS WILL 
FUNNEL THROUGH SOUTHERN NICARAGUA AND NORTHERN COSTA RICA AND  
PRODUCE FRESH NE WINDS ACROSS THE GULF OF PAPAGAYO AND DOWNWIND 
TO 88W ON FRI MORNING AND LAST AT LEAST 24 MORE HOURS. 

$$
STRIPLING