000
AXPZ20 KNHC 282152
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JUL 28 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 
2030 UTC.


...TROPICAL WAVES... 
TROPICAL WAVE ALONG 88W N OF 05N MOVING W AT 15 KT.  CONVECTION 
IS STRONGEST ALONG THE S EDGE OF THE TROPICAL WAVE WHERE BOTH 
DEEP TROPICAL MOISTURE AND STRONG UPPER LEVEL DIFFLUENCE BETWEEN 
THE UPPER LEVEL RIDGE AXIS INTENSIFYING OVER THE SW CARIBBEAN 
AND THE CYCLONIC FLOW ALONG THE COAST OF NW SOUTH AMERICA CAN BE 
FOUND.  THIS TROPICAL WAVE IS EMBEDDED IN THE ITCZ AND NUMEROUS 
MODERATE TO SCATTERED STRONG CONVECTION CAN BE FOUND WITHIN 300 
NM S OF THE ITCZ AXIS BETWEEN 79W AND 90W INCLUDING THE COAST OF 
COSTA RICA AND PANAMA.  THE CENTRAL AND NORTHERN PORTION OF THE 
TROPICAL WAVE LIES IN A REGION WITH LOW PRECIPITABLE WATER 
VALUES AND UPPER LEVEL CONFLUENCE BETWEEN THE RIDGE OVER THE SW 
CARIBBEAN AND A CYCLONE OVER JAMAICA AND...AS A RESULT...REMAINS 
RELATIVELY DEVOID OF CONVECTION.

FARTHER W...THERE IS A SECOND TROPICAL WAVE ALONG 115W BETWEEN 
05N AND 20N MOVING W AT 12 KT.  THIS TROPICAL WAVE IS ALSO 
EMBEDDED IN THE ITCZ WITH SCATTERED MODERATE CONVECTION LYING 
WITHIN 300 NM OF THE ITCZ AXIS FROM 109W TO 122W AND SCATTERED 
MODERATE AND STRONG CONVECTION FROM 19N TO 22N BETWEEN 109W AND 
112W.  THIS WAVE SHOULD MOVE INTO A REGION OF LOWER SEA SURFACE 
TEMPERATURES OVER THE NEXT DAY OR TWO.  THIS SHOULD LIMIT THE 
AVAILABLE ATMOSPHERIC MOISTURE...HENCE THE CONVECTION...WITH THE 
SYSTEM.

  
...ITCZ...
ITCZ AXIS LIES FROM 10N86W TO 06N99W TO 13N113W TO 10N126W TO 
06N140W. NUMEROUS MODERATE TO SCATTERED STRONG CONVECTION CAN 
BE FOUND WITHIN 300 NM S OF AXIS BETWEEN 79W AND 90W INCLUDING 
THE COAST OF COSTA RICA AND PANAMA. SCATTERED MODERATE 
CONVECTION LIES WITHIN 180 NM OF AXIS BETWEEN 92W AND 105W AND 
WITHIN 300 NM OF AXIS FROM 109W TO 122W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION CAN BE FOUND WITHIN 120 NM OF AXIS W 
OF 134W.


...DISCUSSION...
THE MID TO UPPER LEVEL ANTICYCLONE OVER NORTHERN MEXICO AND THE 
SW CONUS WILL BUILD SW OVER THE NEXT FEW DAYS.  EXPECT THE 
TROPICAL WAVE CURRENTLY ALONG 115W TO PUSH NW ALONG THE EDGE OF 
THIS RIDGE INTO COOLER WATERS AS IT ENCOUNTERS THE WEAK INVERTED 
MID LEVEL TROUGH THAT HAS PERSISTED NEAR 135W.  THE REMNANTS OF 
GENEVIEVE SHOULD BE OVERTAKEN BY THIS INVERTED TROUGH...WITH THE 
SYSTEM EXPECTED TO LOOSE ITS CLOSED SURFACE CIRCULATION OVER THE 
NEXT TWO DAYS.

A SURFACE LOW PRESSURE SYSTEM CURRENTLY 1010 MB NEAR 07N95W IS 
EMBEDDED WITHIN THE ITCZ AND IS TRIGGERING SCATTERED MODERATE 
CONVECTION WITHIN 180 NM OF THE ITCZ AXIS BETWEEN 92W AND 105W.  
THIS LOW PRESSURE SYSTEM IS EXPECTED TO PERSIST FOR A DAY OR TWO 
AS IT MOVES W AROUND 10-12 KT BEFORE WEAKENING AS A REGION OF 
UPPER LEVEL CONFLUENCE PASSES OVER THE SYSTEM LIMITING 
CONVECTION.

RELATIVELY DRY CONDITIONS AND WEAK UPPER LEVEL CONFLUENCE IS 
LIMITING CONVECTION OVER MUCH OF MEXICO AND NORTHERN CENTRAL 
AMERICA THIS EVENING.  SOME SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION CURRENTLY FIRING ALONG THE SIERRA MADRE 
OCCIDENTAL AS WELL AS ALONG 20N MAY SURVIVE LONG ENOUGH THIS 
EVENING TO MAKE IT TO THE COAST UNDER WEAK E STEERING FLOW.

$$
SCHAUER CLARK