000
AXPZ20 KNHC 291547
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU MAY 29 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 
1445 UTC.

...SPECIAL FEATURE...
TROPICAL STORM ALMA AT 11.1N 86.8W AT 1500 UTC MOVING N AT 5 KT. 
ESTIMATED MINIMUM CENTRAL PRES 1001 MB.  MAXIMUM SUSTAINED WIND 
40 GUSTS TO 50 KT.  SEE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR FURTHER DETAILS.

ALMA RAPIDLY INTENSIFIED EARLY THIS MORNING OVER WARM E PAC 
WATERS AS CONSTANT FEED OF MOIST AIR OVERCAME FRICTION WITH 
MOUNTAINOUS TERRAIN.  LARGE AND POWERFUL FEEDING BANDS ON ITS W 
SIDE CURVE THROUGH THE SOUTH INTO THE EASTERN QUADRANT WITH THE 
POTENTIAL OF TORRENTIAL RAINS INCREASING SIGNIFICANTLY AS THESE 
BANDS MOVE N OVER LAND.  HIGH TERRAIN MAKE CONDITIONS EVEN MORE 
HAZARDOUS AS IMMINENT FLASH FLOODING WILL RESULT.  HIGH SURF DUE 
TO LARGE SW STORM SWELLS COMPOUND COASTAL DANGERS AND DAMAGES. 
TRACK AND INTENSITY FORECAST FOR ALMA REMAIN COMPLICATED DUE TO 
TERRAIN EFFECTS AND CHANGING CONDITIONS OVER WRN CARIBBEAN WITH 
APPROACHING TRPCL WAVE ALONG 84W.  

...TROPICAL WAVES...
.NONE.

...ITCZ...
AXIS ALONG 09N91W TO 08N109W TO 00N131W.  SCATTERED MODERATE 
CONVECTION WITHIN 90 NM OF AXIS FROM 99W TO 121W.

...DISCUSSION...
UPPER LEVEL TROUGH COMBINED WITH MID-UPPER LEVEL ANTICYCLONE 
GYRE CENTERED OFF TIP OF BAJA CALIFORNIA HAVE MANAGED TO 
EFFECTIVELY DRY OUT AIR MASS WITH MODERATE TO STRONG CONVERGENT 
FLOW ALOFT.  DRYNESS EXTENSION COVER MOST E PAC N OF 07N W OF 
100W WITH ONLY THIN SWATH OF MOISTURE ALONG ITCZ BETWEEN 03N-07N 
E OF 121W.  

VERY NARROW UPPER LEVEL TROUGH FROM GULF OF TEHUANTEPEC TO 
08N110W SEPARATE ABOVE ANTICYCLONE FROM CARIBBEAN UPPER RIDGE 
WHICH DOMINATED FLOW OVER REMAINDER E PAC INCLUDING PROVIDING 
FAVORABLE OUTFLOW OVER TRPCL STORM ALMA.  WITH SUCH ADVANTAGE 
OVERHEAD...ALMA STANDS A CHANCE OF FURTHER INTENSIFYING BEFORE 
LANDFALL EXPECTED LATER TONIGHT.  

ELSEWHERE AT THE SURFACE...
PRES GRADIENT ASSOCIATED WITH TRPCL STORM ALMA AND RIDGE OVER 
GULF OF MEXICO PRODUCING DUE N WINDS ACROSS GULF OF TEHUANTEPEC.
EVENT SHOULD BE SHORT-LIVED AS LIFE SPAN FOR ALMA IS ONLY 36 HRS
...BUT LINGERING SWELL ARE EXPECTED TO REMAIN.  

$$
WALLY BARNES