000
AXPZ20 KNHC 072152
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON NOV 07 2011

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...MONSOON 
TROUGH EXTENDS FROM 08N84W TO 11N115W TO 10N120W...THEN 
TRANSITIONS TO ITCZ AXIS FROM 10N120W TO 09N130W TO 08N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 60 NM OF 
AXIS W OF 110W.

...DISCUSSION...
UPPER FLOW N OF 20N IS BECOMING MORE ZONAL AS AN EXITING DEEP 
LAYER TROUGH ALONG 115W CONTINUES TO PUSH E THROUGH THE ROCKIES 
AND BAJA CALIFORNIA. ALTHOUGH THE ASSOCIATED COLD FRONT AS 
BECOME DIFFUSE OVER THE GULF OF CALIFORNIA AND PACIFIC WATERS 
OFF BAJA...A TIGHT PRES GRADIENT REMAINS AS HIGH PRES BUILDS 
FROM THE WEST. SHIP OBSERVATIONS AND DATA FROM A 1715 UTC ASCAT 
SCATTEROMETER PASS SHOW 20 KT NW WINDS ALONG THE NORTHERN COAST 
OF BAJA CALIFORNIA. A REINFORCING SHORT WAVE TROUGH WITHIN THE 
NW FLOW ALOFT IS BARELY DISCERNIBLE ON WATER VAPOR IMAGERY N OF 
THE AREA LONG 135W. THIS WILL AMPLIFY SLIGHTLY AND SHIFT INTO 
THE AREA OFF THE N BAJA COAST THROUGH EARLY TUE. THE SHORT WAVE 
RIDGING THAT FOLLOWS THIS TROUGH WILL REINFORCE THE SURFACE HIGH 
PRES THAT WILL BE CENTERED NEAR 30N130W BY LATE TUE. THIS IN 
TURN WILL MAINTAIN A BROAD AREA OF 20 KT TRADE WINDS NOTED IN 
THE ASCAT SCATTEROMETER DATA THAT GENERALLY COVERS THE AREA N 
BETWEEN THE ITCZ AND 25N...W OF 115W. 

FAIRLY WARM SEA SURFACE TEMPERATURES S OF THE ITCZ W OF 120W ARE 
ALLOWING ENHANCED 20 KT SE GRADIENT FLOW BETWEEN THE EQUATOR AND 
THE ITCZ TO MIX TO THE SURFACE. CONVERGENCE OF THESE WINDS WITH 
THE FRESH NE TRADES IS RESULTING IN NEAR CONTINUOUS MODERATE 
CONVECTION ALONG THE ITCZ W OF 125W. FURTHER E ALONG THE 
ITCZ...A SURFACE TROUGH PERSISTS NEAR 114W. THIS 
QUASI-STATIONARY SURFACE FEATURE IS AN ARTIFACT OF UPPER LEVEL 
DIVERGENCE ON THE N SIDE OF AN UPPER CYCLONE CENTERED NEAR 
05N105W...S OF THE DEEP LAYER TROUGH N OF THE AREA ALONG 115W. 

ALTHOUGH THERE IS SCANT DATA TO VERIFY IT...GLOBAL MODELS 
SUGGEST SW WINDS ARE INCREASING TO 20 KT S OF PANAMA OVERNIGHT. 
A SHIP OFF WESTERN PANAMA DID REGISTER 20 KT EARLIER TODAY. 
SCATTERED SHOWERS AND TSTMS ARE NOTED IN THIS AREA...AND SURFACE 
PRES MAY BE DROPPING SLIGHTLY...AN INDICATION THAT WINDS MAY 
INCREASE ACCORDINGLY OVER THE NEXT COUPLE OF DAYS TO BARELY 20 
KT. 
 
FOR THE GULF OF CALIFORNIA...LAND BASED OBSERVATIONS FROM SAN 
FELIPE IN THE FAR NW COAST OF THE GULF OF CALIFORNIA ALSO SHOWED 
WINDS NW WINDS TO 20 KT...A GOOD INDICATION THAT FRESH NW FLOW 
PERSISTS OVER GULF OF CALIFORNIA WATERS. WINDS DIMINISH OVER THE 
NORTHERN GULF OVERNIGHT AS THE HIGH PRES BUILDS INTO THE AREA 
FROM THE WEST. THIS WILL ALSO PRESENT A TIGHTER GRADIENT FURTHER 
S DOWN THE GULF THROUGH TUE. WINDS WILL INCREASE AGAIN OVER THE 
NORTHERN GULF STARTING TUE NIGHT AS THE HIGH PRES OVER THE NE 
PACIFIC BUILDS EASTWARD TO THE NORTH OF THE GULF OVER THE GREAT 
BASIN. GLOBAL MODELS ARE NOT SHOWING GALE FORCE WINDS AT THIS 
TIME...MOST LIKELY DUE TO THE PRESENCE OF THE RESIDUAL SURFACE 
HIGH PRES OFF THE N BAJA COAST. 

GULF OF TEHUANTEPEC...A STRONG COLD FRONT WILL MOVE THROUGH THE 
WESTERN GULF OF MEXICO WED. NORTHERLY WINDS AT 15 TO 20 KT WILL 
SURGE INTO THE GULF OF TEHUANTEPEC AS EARLY AS LATE WED POSSIBLY 
INCREASING TO GALE FORCE EARLY THU.

$$
CHRISTENSEN