000
AXPZ20 KNHC 290926
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON JUN 29 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0700 UTC.

...TROPICAL WAVE...

THE SOUTHERN END OF A TROPICAL WAVE PRIMARILY OVER THE WESTERN 
CARIBBEAN LIES ALONG 82W N OF 06N. THE TROPICAL WAVE IS MOVING W 
AT 10 TO 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
LIES OVER THE EASTERN PACIFIC N OF THE ITCZ TO THE COAST OF 
CENTRAL AMERICA BETWEEN 85W AND 89W WHILE SCATTERED MODERATE 
CONVECTION CAN BE FOUND ELSEWHERE E OF THE WAVE WITHIN 120 NM OF 
THE ITCZ AXIS BETWEEN 86W AND 93W AND OVER FAR WESTERN 
PANAMA...COSTA RICA...AND MUCH OF SOUTHERN AND WESTERN 
NICARAGUA. 

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 07N78W TO 09N90W TO 09N105W TO 
14N124W TO 11N133W. ASIDE FROM THE CONVECTION NEAR THE TROPICAL 
WAVE MENTIONED ABOVE...SCATTERED MODERATE CONVECTION LIES WITHIN 
90 NM OF THE ITCZ AXIS BETWEEN 98W AND 103W.

...DISCUSSION...

E OF 120W...
THERE IS PLENTIFUL ATMOSPHERIC MOISTURE IN THE REGION E OF 
125W...WITH SATELLITE TOTAL PRECIPITABLE WATER VALUES ON THE 
ORDER OF 1.5 TO 2.5 INCHES OVER THE REGION N OF 05N. THIS 
MOISTURE IS BEING DRAWN NORTHWARD BY SOUTHERLY FLOW ON THE EAST 
SIDE OF THE MID TO UPPER LEVEL LOW NEAR THE SOUTHERN TIP OF BAJA 
CALIFORNIA...WITH SCATTERED MODERATE CONVECTION FIRING WITHIN 60 
NM OF THE MEXICAN COAST FROM 19N TO 24N WHERE THERE IS UPPER 
LEVEL DIFFLUENCE BETWEEN THIS LOW AND THE UPPER LOW OVER THE 
SOUTHEASTERN RIO GRANDE VALLEY AS WELL AS ON THE MAINLAND MEXICO 
GULF OF CALIFORNIA COAST FROM 26N TO 28N WITHIN THE DIFFLUENT 
REGION BETWEEN THE MEAN UPPER TROUGH AXIS TO THE SE AND THE 
UPPER RIDGE TO THE N. THE MID TO UPPER LEVEL LOW NEAR THE 
SOUTHERN TIP OF BAJA CALIFORNIA ALONG WITH ITS SURFACE 
REFLECTION...CURRENTLY A TROUGH FROM 27N113W TO 20N11W...WILL 
WEAKEN AND DRIFT SW OVER THE NEXT FEW DAYS. THIS SYSTEM IS IN AN 
AREA OF GENERALLY STABLE ATMOSPHERIC CONDITIONS WHICH SHOULD 
LIMIT CONVECTION. THE STRONGEST CONVECTION E OF 120W LIES WITH 
THE AFOREMENTIONED TROPICAL WAVE...BUT THERE IS ALSO SCATTERED 
MODERATE WITHIN 90 NM OF AXIS BETWEEN 98W AND 103W TO THE W OF A 
SURFACE TROUGH EMBEDDED IN THE ITCZ ALONG 96W FROM 01N TO 14N. 
CONVECTION WITH THIS TROUGH MAY BE ENHANCED OVER THE NEXT 
DAY OR TWO AS IT MOVES INTO A REGION OF INCREASED UPPER LEVEL 
DIFFLUENCE.

W OF 120W...
A SURFACE TROUGH EMBEDDED IN THE ITCZ LIES FROM 14N131W TO 
09N140W. THE QUIKSCAT PASS FROM 0254 UTC SHOWS WINDS TO 20 KT 
OVER FORECAST WATERS NEAR THE TROUGH FROM 10N TO 16N W OF 128W.  
THE SURFACE TROUGH WILL SLOWLY MIGRATE NW OVER THE NEXT 48 HOURS 
AS THE PATTERN BECOMES MORE AMPLIFIED. LOOK FOR THE UPPER TROUGH 
CURRENTLY CENTERED OVER NW WATERS FROM 30N132W TO 20N126W TO BE 
RELOADED BY THE MID LATITUDE TROUGH CURRENTLY PASSING N OF 
HAWAII. THE SOUTHERLY FLOW ON THE LEADING EDGE OF THE AMPLIFYING 
TROUGH SHOULD STEER SOME OF THE MID-LEVEL ENERGY AND MOISTURE 
ASSOCIATED WITH THIS SURFACE TROUGH NORTHWARD AWAY FROM THE 
ITCZ. THE NORTHWARD MIGRATING SURFACE TROUGH HAS MOVED UNDER A 
LESS DIFFLUENT REGION CLOSER TO THE UPPER RIDGE AXIS ALONG 15N W 
OF 125W. AS A RESULT...CONVECTIVE ACTIVITY IS LIMITED TO 
SCATTERED MODERATE CONVECTION WITHIN 30 NM OF TROUGH AXIS WITH 
MORE WIDESPREAD MODERATE CONVECTION FARTHER IN THE MORE 
DIFFLUENT REGION S OF THE SURFACE TROUGH W OF 138W FROM 06N TO 
09N. THE INCREASED TROUGHING ALOFT OVER NW WATERS WILL BREAKDOWN 
THE RIDGE AT THE SURFACE OVER THE NEXT FEW DAYS...DIMINISHING 
TRADE WINDS. FARTHER S...THE QUIKSCAT PASS FROM 0258 UTC SHOWS E 
TO SE WINDS TO 20 KT S OF 07N W OF 127W. THESE CONDITIONS ARE 
EXPECTED TO PERSIST OVER THE NEXT FEW DAYS...WITH SEAS RISING 
ABOVE 8 FT IN SE SWELL LATE TONIGHT. 

$$
SCHAUER CLARK