000
AXPZ20 KNHC 160920
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED MAR 16 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0730 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 04N85W 
TO 06N106W TO 03N116W TO 04N134W TO 04N140W. SCATTERED MODERATE 
CONVECTION LIES WITHIN 240 NM N AND 90 NM S OF THE ITCZ AXIS W 
OF 109W.

...DISCUSSION...
AN UPPER TROUGH EXTENDS FROM NW MEXICO NEAR 24N107W THROUGH 
20N125W TO 13N140W. A 50-70 KT UPPER JET LIES BETWEEN THE TROUGH 
AXIS AND 17N. THIS JET MERGES WITH A 40-50 KT SOUTHWESTERLY JET 
ALOFT THAT IS CENTERED FROM 00N100W TO NEAR THE GULF OF FONSECA 
13N88W. THE RESULTING CONFLUENT FLOW OVER SOUTHERN MEXICO AND 
CENTRAL AMERICA COUPLED WITH SUBSIDENT CONDITIONS INDICATED ON 
WATER VAPOR IMAGERY IS PROHIBITING THE DEVELOPMENT OF DEEP 
CONVECTION OVER THE AREA S OF 25N AND E OF 109W. THE NORTHERN 
PORTION OF THE UPPER TROUGH WILL BE RELOADED WITH NEW ENERGY AS 
IT MOVES EASTWARD INTO THE GULF OF MEXICO WHILE THE REMAINDER OF 
THE TROUGH OVER THE FORECAST AREA WILL BE PUSHED SLIGHTLY 
SOUTHEASTWARD OVER THE NEXT TWO DAYS AS A BROAD UPPER TROUGH 
MOVES INTO THE NORTHERN PORTION OF THE AREA. A WEAK COLD FRONT 
ASSOCIATED WITH THIS BROAD TROUGH HAS ENTERED NW WATERS FROM 
30N135W TO 29N140W THIS MORNING. THIS FRONT IS USHERING IN A NEW 
BATCH OF NW SWELL WITH SEAS AS HIGH AS 15-17 FT OVER NW WATERS 
TODAY. 

HIGH PRES DOMINATES THE FORECAST AREA N OF 15N W OF 115W. THE 
AFOREMENTIONED WEAK COLD FRONT IS COMPROMISING THE STRENGTH OF 
THE RIDGE OVER THE AREA. HIGH PRES WILL BUILD NW OF THE AREA 
BEHIND THE FRONT LATER TODAY AND WILL ACT TO EXPAND THE TRADE 
WINDS INTO NW WATERS THIS AFTERNOON THROUGH THU MORNING. THE 
AREA OF FRESH TRADE WINDS CURRENTLY LIES FROM 05N TO 20N W OF 
120W ACCORDING TO THE 0202 UTC WINDSAT PASS. FRESH TO STRONG NW 
WINDS LIE E OF THE HIGH ALONG THE COAST OF THE BAJA CALIFORNIA 
PENINSULA ACCORDING TO THE 0446 UTC ASCAT PASS AND SHIP A8RW5 
WHICH REPORTED 21 KT NEAR 23N111W AT 0600 UTC. THESE WINDS ARE 
EXPECTED TO BECOME FRESH AND SHRINK NORTHWARD ALONG THE BAJA 
CALIFORNIA NORTE COAST THU AS THE HIGH REORGANIZES NW.

CONVECTION ALONG THE ITCZ W OF 109W IS BEING ENHANCED BY 
DIFFLUENT FLOW ALOFT BETWEEN THE SOUTHWESTERLY UPPER JET ON THE 
LEADING EDGE OF THE AFOREMENTIONED UPPER TROUGH EXTENDING 
SOUTHWESTWARD FROM NW MEXICO AND A 50-70 KT WESTERLY JET 
CENTERED JUST S OF THE EQUATOR W OF 109W. THIS CONVECTION IS 
DESCRIBED IN THE ITCZ SECTION ABOVE.

GAP WINDS...
GULF OF TEHUANTEPEC...N WINDS WILL CONTINUE TO FUNNEL THROUGH 
THE ISTHMUS OF TEHUANTEPEC THROUGH THE FORECAST PERIOD AS HIGH 
PRES BUILDS OVER NE MEXICO. WINDS WILL PULSE TO 25 KT IN THE 
MORNING HOURS WHEN DRAINAGE FLOW THROUGH THE PASS WILL BE AT ITS 
DIURNAL MAXIMUM. 

GULF OF PAPAGAYO...DRAINAGE FLOW OFF THE LANDMASS WILL HELP 
MAINTAIN WINDS AT THE ADVISORY LEVEL DURING THE EARLY MORNING 
HOURS THROUGH THU MORNING. AS HIGH PRES BUILDS OVER SOUTHERN 
MEXICO...LOOK FOR WINDS TO INCREASE TO 25 KT DOWNWIND OF THE 
GULF OF PAPAGAYO BY FRI MORNING.

GULF OF PANAMA...THE PRES GRADIENT WILL BUILD BETWEEN THE 
COLOMBIAN LOW AND HIGH PRES OVER SOUTHERN MEXICO ALLOWING FOR N 
WINDS TO REACH ADVISORY CRITERIA IN THE GULF OF PANAMA BY THU 
MORNING AND REMAIN THERE THROUGH THE END OF THE FORECAST PERIOD 
FRI MORNING.  

$$
SCHAUER