000
AXPZ20 KNHC 011530
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI AUG 01 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 
1530 UTC.

...TROPICAL WAVES... 

TROPICAL WAVE IS ALONG 94W N OF 4N MOVING W 15 KT. VISIBLE 
IMAGERY REVEALS A FAIR AMOUNT OF CYCLONIC TURNING IN THE 
LOW-LEVELS WITH WEAK VORTICITY MAX ALONG THE AXIS NEAR 9N. 
SCATTERED PATCHES OF MODERATE CONVECTION ARE WITHIN 240 NM E AND 
360 NM W OF THE WAVE AXIS.

TROPICAL WAVE IS ALONG 114W FROM 4N-18N MOVING W 15 KT. THIS 
WAVE IS CAUSING A SLIGHT PERTURBATION IN THE ITCZ EXPANDING 
CLOUDINESS NWD BUT CONVECTION REMAINS CONFINED TO THE ITCZ FROM 
6N-9N BETWEEN 112W-118W. 

...ITCZ...

ITCZ AXIS IS CENTERED E TO W BETWEEN 08N AND 10N E OF 140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 180 NM 
EITHER SIDE OF A LINE FROM 05N77W TO 11N93W TO 08N117W TO 
11N132W.

...DISCUSSION...

E OF 120W...
MAIN AREA OF INTEREST IS A LOW PRESSURE SYSTEM EMBEDDED WITHIN 
THE ITCZ NEAR 10N104W...ANALYZED 1007 MB. THE ROTATION OF CLOUD 
ELEMENTS ON VISIBLE IMAGERY SUGGEST THAT LOW-LEVEL CENTER IS 
LOCATED NEAR THE ERN EDGE OF A BLOW-UP OF SCATTERED MODERATE TO 
STRONG CONVECTION FROM 7N-11N BETWEEN 104W-107W. SLOW 
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT COUPLE OF 
DAYS IF IT BECOMES SEPARATED FROM THE ITCZ. ANOTHER AREA OF LOW 
PRES IS LOCATED ABOUT 120-150 NM OFF THE COAST OF MEXICO NEAR 
18N106W. THIS LOW EXHIBITS SOME SIMILAR QUALITIES TO THE ONE 
FARTHER S AS A FAIR AMOUNT OF CYCLONIC TURNING IS NOTED IN EARLY 
VIS AND SHORTWAVE IR IMAGES. ADDITIONALLY...SHIP DGAS REPORTED 
23 KT SE WINDS ABOUT 75 NM IN THE NE QUADRANT AT 12Z. LATEST 
ASCAT PASS...HOWEVER...SHOWS SOME CYCLONIC TURNING BUT NO 
EVIDENCE OF A CLOSED CIRCULATION. LIGHTNING DATA DEPICTS 
SCATTERED TSTMS WITHIN 120 NM OF THE CENTER AND FARTHER N INTO 
THE SRN GULF OF CALIFORNIA FROM 21N-25N. 

W OF 120W...
THE MID AND UPPER FLOW N OF 20N IS MAINLY FROM THE S OR SW 
BETWEEN AN UPPER HIGH OVER THE SW CONUS AND AN UPPER LOW JUST N 
OF THE HAWAIIAN ISLANDS. HOWEVER...LITTLE MOISTURE IS BEING 
ADVECTED FROM THE DEEP TROPICS WITH THIS FLOW. S OF 20N...THE 
UPPER PATTERN IS A BIT MORE DIFFLUENT DUE TO A WEAK TROUGH ALONG 
137W...HOWEVER ALL OF THE SIGNIFICANT MOISTURE IS CONFINED TO 
THE ITCZ. AT THE SFC...WEAK HIGH PRES IS ALLOWING FOR FAIRLY 
LIGHT NE TRADES BUT THERE IS A SLIGHT ENHANCEMENT NW OF A 
LOW-LEVEL TROUGH THAT RUNS FROM 18N123W TO 10N129W. THE TRADES 
WILL LIKELY STRENGTHEN SLIGHTLY TO NEAR 20 KT OVER THE WEEKEND 
AS HIGH PRES RIDGING AMPLIFIES N OF THE ZONE.

$$
CANGIALOSI