000
AXPZ20 KNHC 132209
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN APR 13 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 
2130 UTC.

...ITCZ...

ITCZ CENTERED ALONG 6N77W TO 7N105W TO 5N140W. SCATTERED 
MODERATE CONVECTION WITHIN 120 NM N OF AXIS E OF 85W. SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION WITHIN 120 NM S OF AXIS 
BETWEEN 90W AND 95W. SCATTERED MODERATE CONVECTION FROM 7N TO 
10N BETWEEN 110W AND 119W. SCATTERED MODERATE CONVECTION WITHIN 
60 NM OF AXIS W OF 135W.

...DISCUSSION...

E OF 110W...
MAIN ISSUE IS THE DEVELOPMENT OF A RARE LATE SEASON WIND EVENT 
THROUGH THE GULF OF TEHUANTEPEC OVER THE NEXT 48 HOURS. COLD AIR 
MOVING THROUGH THE GULF OF MEXICO IS FILTERING THROUGH THE 
TEHUANTEPEC ISTHMUS AND INTO THE GULF OF TEHUANTEPEC CURRENTLY. 
A MORNING HIGH RESOLUTION QUIKSCAT PASS INDICATED 30 KT WIND WAS 
ALREADY ONGOING. WITH THAT...GALE CONDITIONS LOOK PROMISING BY 
THIS EVENING. MORE INTERESTING IS THE FACT THAT GFS IS SHOWING 
925 MB WINDS TO 55 KT BY LATE MON...AND REGIONAL NAM HAS 925 MB 
WINDS TO 65 KT BY SLIGHTLY EARLIER. WATER TEMPERATURES IN THE 
GULF OF TEHUANTEPEC ARE IN THE LOWER 80S. THIS WILL ADD ENOUGH 
INSTABILITY TO MIX DOWN THE STRONGER WINDS...LENDING CREDENCE 
TO WIND SPEEDS REACHING STORM CONDITIONS BY MIDDAY TOMORROW. 
FURTHER S...FRESH TO STRONG ELY TRADES IN THE CARIBBEAN ARE 
PROMPTING A PUSH OF 20 TO 25 KT WINDS THROUGH THE GULF OF 
PAPAGAYO...AS PER MORNING SCATTEROMETER DATA. MODELS PICK UP ON 
THIS LATE...BUT SHOW THE EVENT PERSISTING THROUGH MID WEEK. 
MEANWHILE DIVERGENCE ALOFT ON THE SOUTH SIDE OF AN  UPPER 
ANTICYCLONE OVER THE SW CARIBBEAN IS ENHANCING CONVECTION ALONG 
THE ITCZ E OF 110W...AND AIDING DEVELOPMENT OF A LOW PRES AREA 
NEAR ALONG THE ITCZ N OF THE GALAPAGOS. 

W OF 110W...
AMPLIFIED UPPER PATTERN IN PLACE N OF 20N AS WEAK SHORT WAVE 
TROUGH EXITS E INTO SW U.S. AND IS FOLLOWED BY A MID/UPPER RIDGE 
CENTERED NEAR 27N132W. THIS IS OBSTRUCTING EWD PROGRESS OF A  
SHORT WAVE TROUGH DIGGING INTO THE N CENTRAL PACIFIC FURTHER TO 
THE NW. AS A RESULT...A SURFACE COLD FRONT NW OF THE AREA IS 
STALLING AS IT ADVANCES E. STRONG 1045 MB SURFACE HIGH PRES 
CENTERED NEAR 41N160W MOVES LITTLE EWD THROUGH THE NEXT 24 TO 48 
HOURS...BUT TIGHT PRES GRADIENT ON THE PERIPHERY OF THE HIGH 
WILL ALLOW FRESH TO STRONG NE WINDS INTO THE FAR NW PORTION OF 
THE DISCUSSION AREA THROUGH TUE. IN ADDITION...FRESH  TRADES 
PERSIST TO THE S.

$$
CHRISTENSEN