000
AXPZ20 KNHC 092154
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU JUL 09 2009

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 
2000 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS N OF 05N TO THE COAST OF MEXICO JUST W OF THE 
GULF OF TEHUANTEPEC ALONG 97W MOVING W 10-15 KT. THE WAVE AXIS 
EXTENDS NORTHWARD INTO THE BAY OF CAMPECHE. THE SOUTHERN END OF 
THE WAVE CROSSES THE ITCZ NEAR 08N. SCATTERED MODERATE 
CONVECTION LIES WITHIN 270 NM W OF THE TROPICAL WAVE AXIS FROM 
04N TO 12N. 

A 1008 MB LOW PRESSURE SYSTEM CAN BE FOUND AT 10N ON THE 
TROPICAL WAVE AXIS ALONG 109W/110W. THE TROPICAL WAVE EXTENDS 
FROM 05N TO 13N. THIS TROPICAL WAVE CROSSES THE ITCZ NEAR 09N. 
SCATTERED MODERATE CONVECTION IS LOCATED WITHIN 150 NM W AND 120 
NM E OF THE TROPICAL WAVE AXIS FROM 08N TO 13N. THIS SYSTEM HAS 
BECOME BETTER ORGANIZED AND FURTHER DEVELOPMENT IS POSSIBLE 
DURING THE NEXT 48 HOURS.  

...ITCZ...
THE ITCZ AXIS IS ALONG 08N78W TO 10N106W TO 06N117W TO 10N128W 
TO 09N140W. ISOLATED MODERATE CONVECTION LIES WITHIN 210 NM N 
AND 150 NM S OF THE ITCZ AXIS BETWEEN 114W AND 124W.

...DISCUSSION...
AN QUIKSCAT PASS FROM 1256 UTC TODAY SHOWS A LOW PRES 
CIRCULATION HAS DEVELOPED NEAR 10N ON THE TROPICAL WAVE ALONG 
109W/110W. CONVECTION ON THE NE SIDE OF THE LOW CAUSED MANY OF 
THE RETRIEVALS TO BE RAIN-FLAGGED IN THAT QUADRANT...BUT THERE 
ARE A FEW RELIABLE 20 TO 25 KT RETRIEVALS IN THE N AND S 
QUADRANTS. THE SYSTEM LIES IN A REGION OF UPPER LEVEL DIFFLUENCE 
ASSOCIATED WITH A RIDGE AXIS FROM THE UPPER LEVEL ANTICYCLONE 
CENTERED NEAR 14N106W TO 08N124W. CURRENTLY...THERE IS NO STRONG 
CONVECTION NOTED WITH THIS LOW...BUT CONDITIONS ARE CONDUCIVE 
FOR FURTHER DEVELOPMENT OF DEEP CONVECTION WITH THE SYSTEM THIS 
AFTERNOON/EVENING.

THE REMNANT LOW OF BLANCA HAS SCATTERED LOW-TOPPED CONVECTION 
DISPLACED TO THE N OF ITS LOW LEVEL CENTER. THE SYSTEM LIES IN A 
REGION OF INCREASING SOUTHERLY FLOW ALOFT ON THE LEADING EDGE OF 
THE UPPER LEVEL TROUGH CENTERED ALONG 140W. THE QUIKSCAT PASS 
FROM 1440 UTC SHOWS WINDS TO 30 KT PRIMARILY WITHIN 120 NM NW 
QUADRANT AND A REGION OF 20 TO 25 KT WINDS N OF 22N BETWEEN 121W 
AND 129W WHERE THE PRESSURE GRADIENT IS STRONG BETWEEN THE 
REMNANT LOW OF BLANCA AND THE SURFACE RIDGE FROM 30N133W TO 
28N120W. LITTLE CHANGE IN THESE CONDITIONS IS EXPECTED OVER THE 
NEXT FEW DAYS AS BLANCA CONTINUES ON ITS WNW PATH NEAR 10 KT.

STRONG NE TRADE WINDS ARE EXPECTED TO BLEED THROUGH CENTRAL 
AMERICA FROM THE WESTERN CARIBBEAN ACROSS THE GULF OF PAPAGAYO 
BEGINNING OVERNIGHT AND PERSISTING THE NEXT FEW DAYS. WINDS TO 
20 KT WILL IMPACT THE REGION W OF 88W...WITH WINDS POSSIBLY 
INCREASING IN THE EARLY MORNING HOURS WHEN DRAINAGE FLOW IS AT A 
MAXIMUM.

$$
SCHAUER CLARK