000
AXPZ20 KNHC 202110
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON OCT 20 2008

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 
2045 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 05N77W TO 11N97W TO 09N109W TO 
06N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WITHIN 
90 NM OF AXIS BETWEEN 108W AND 111W. SCATTERED MODERATE 
CONVECTION FROM 08N TO 12N BETWEEN 125W AND 132W. 

...DISCUSSION...

STRONG WINDS REMAIN THROUGH THE GULF OF TEHUANTEPEC JUST BELOW 
GALE FORCE AS HIGH PRES OVER THE GULF OF MEXICO SHIFTS EAST. 
THESE WINDS WILL CONTINUE TO BE 20 TO 30 KT THROUGH TUE 
WEAKENING SLIGHTLY ON WED BUT RETURN TO NEAR GALE FORCE LATE 
THU/EARLY FRI AS ANOTHER FRONT MOVES ACROSS THE GULF OF MEXICO. 

A WEAK SURFACE 1012 MB LOW IS CENTERED NEAR 11N97W WITH AN UPPER 
LEVEL ANTICYCLONE CENTERED NEAR 15N100W AND AN UPPER RIDGE AXIS 
EXTENDING E ALONG 15N THROUGH NORTHERN CENTRAL AMERICA PROVIDING 
MODERATE EASTERLY SHEAR ACROSS THE LOW AND ITCZ. DEEP LAYER 
MOISTURE IS NOT PARTICULARLY ABUNDANT...AND CONVECTION IS MODEST 
NEAR THE LOW. UPPER DIFFLUENCE ON THE EAST SIDE OF A WEAK UPPER 
LOW IS EVIDENT NEAR 12N113W IS ENHANCING MODEST CONVECTION ALONG 
THE ITCZ AND SUSTAINING A 1013 MB SURFACE LOW NEAR 09N111W. 

FURTHER NORTH...SCATTEROMETER DATA SHOW 20 KT NORTHERLY FLOW OFF 
THE LENGTH OF THE BAJA COAST...ON THE EASTERN PERIPHERY OF 1028 
MB HIGH PRES NEAR 31N136W. A BROAD SWATH OF 20 TO 25 KT TRADES 
IS EVIDENT S OF THE SURFACE HIGH...MAINLY FROM 10N TO 20N W OF 
120W. THE HIGH PRES WILL WEAKEN AS AN UPPER TROUGH DIGS INTO THE 
NE PACIFIC THROUGH WED.

$$
WALLACE