000
AXPZ20 KNHC 261952
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1700 UTC SAT JUL 26 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...SPECIAL FEATURE...
TROPICAL STORM GENEVIEVE AT 17.4N 120.4W AT 26/1500 UTC MOVING W 
AT 12 KT.  MAXIMUM SUSTAINED WIND 50 GUSTS TO 60 KT.  MINIMUM 
CENTRAL PRES 997 MB.  SEE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.  AREA 
OF DEEP CONVECTION AROUND GENEVIEVE HAS BEEN HOLDING STEADY FOR 
LAST 4-6 HR...BUT TOPS HAVE BEGUN THEIR WARMING CYCLE AS STORM 
APPROACHES MUCH DRIER AND MORE STABLE AIR MASS WITH COOLER SSTS.
WHILE UPPER ENVIRONMENT NOT UNFAVORABLE MODEL GUIDANCE AND 
FORECAST LEAN TOWARD WEAKENING AND EVENTUYALLY DYING SYSTEM. 

...TROPICAL WAVES... 
TROPICAL WAVE ALONG 95W N OF 05N MOVING W 10 KT.  AREA OF 
DIFFLUENT AIR ABOVE NRN HALF OF WAVE LIKELY TO MAINTAIN DEEP 
CONVECTION WHILE SRN HALF DEALS WITH ADVERSE ENVIRONMENT.  
PLENTY OF MOISTURE FLUX AVAILABLE FOR ENERGYZING WAVE IF MORE 
FAVORABLE CONDITIONS MAINTAIN SYSTEM GOING. 
  
...ITCZ...
ITCZ AXIS ALONG 08N78W TO 07N88W TO 13N94W TO 09N127W TO 10N135W 
TO 09N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION 
WITHIN 120 NM S OF AXIS E OF 91W.  SCATTERED MODERATE CONVECTION 
WITHIN 240 NM OF AXIS FROM 100W TO 120W.

...DISCUSSION...
UPPER LEVEL RIDGE CENTERED AT 19N139W KEEPS REGION N OF 13N W OF 
123W VERY DRY DUE TO MODERATE TO STRONG AIR MASS SUBSIDENCE 
ALOFT.  THIS IS THE DRY AREA GENEVIEVE IS COMING INTO DOOMING 
ITS TENURE.  WEAK UPPER LEVEL TROUGH ALLOWS MINOR AMOUNT OF 
MOISTURE TO ENCROACH N OF 27N FROM 120W-125W WITH NO SIGNIFICANT 
CONSEQUENCES.  

SECOND UPPER LEVEL RIDGE OVER TEXAS KEEPS OUTFLOW FROM GENEVIEVE 
GOING BUT EVENTUALLY BECOME USELESS AS SYSTEMS DRIFT APART 
WITHIN NEXT 24-36 HR.  CARIBBEAN RIDGE ALOFT PUMPING SIGNIFICANT 
AMOUNTS OF TROPICAL MOISTURE INTO E PAC AT 10N-12N ENHANCING 
CONVECTION ALONG ITCA LATITUDES.

ELSEWHERE AT THE SURFACE...
BROAD HIGH PRES CENTER 1034 MB WELL NW OF BASIN MAINTAINS 
CONTROL OVER CLOUD DEVELOPMENT AS IT EXTENDS SE TO THE FRINGES 
OF GENEVIEVE.  

STRONG WRN CARIBBEAN WINDS SPILLING OVER E PAC THROUGH GULF OF 
PAPAGAYO.  CONDITIONS SHOULD LAST THROUGH FORECAST PERIOD WITH 
LITTLE CHANGE.  

CROSS EQUATORIAL SW SWELL TRAIN CREEPING N BRING 8-9 FT SEAS S 
OF ITCZ E OF 125W.  
 
$$
WALLY BARNES