000
AXPZ20 KNHC 190926
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JUL 19 2007

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 
0845 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 92W N OF 2N MOVING W 5 TO 10 KT. ONE SMALL PATCH 
OF CONVECTION ALONG THE ITCZ OTHERWISE THIS WAVE IS NOT VERY ACTIVE.
  
TROPICAL WAVE ALONG 113W N OF 4N MOVING W AT 10 TO 15 KT. SCATTERED 
MODERATE TO STRONG CONVECTION ALONG THE AXIS AND IN A DEEP LAYER OF 
MOISTURE. THERE IS EVIDENCE OF ANTI-CYCLONIC FLOW IN THE HIGH LEVELS 
WHICH IS AIDING THE CONVECTION. 

TROPICAL WAVE ALONG 127W FROM 3N TO 15N MOVING W 10 TO 15 KT. WHILE 
THE ITCZ BOWS NWD ALONG THE WAVE AXIS..LITTLE ELSE IS GOING ON..NOT 
EVEN ISOLATED MODERATE CONVECTION.

...ITCZ...
AXIS ALONG 8N78W 7N93W 14N112W 9N125W 13N133W 7N140W. SCATTERED 
MODERATE CONVECTION NEAR 7N79W 8N89W AND 8N98W. SCATTERED MODERATE 
ALONG A LINE FROM 16N111W TO 9N117W. SCATTERED MODERATE WITHIN 90 NM 
OF 9N123W AND WITHIN 30 NM OF A LINE FROM 12N135W TO 8N140W.

OTHER MODERATE TO STRONG CONVECTION NEAR THE CENTRAL AMERICAN COAST 
NEAR 11N89W 13N93W AND 16N96W.

...DISCUSSION...

AN UPPER TROUGH ALONG 130W N OF 28N IS GETTING A NEW SURGE OF ENERGY 
FROM A DIGGING JET FROM OVER THE N PACIFIC. THE TROUGH IS SANDWICHED 
BETWEEN TWO MID LEVEL RIDGES..ONE OVER THE SW CONUS AND THE OTHER W 
OF 140W.  AN INVERTED TROUGH IN THE MID LEVELS EXTENDS NE FROM OFF 
THE MEXICAN COAST NEAR 20N110W TO ERN TX. ON THE SURFACE TONIGHT NOW 
TRPL DEPRESSION COSME HAS MOVED W OF THE AREA. A TRPL WAVE ALONG 90W 
IS SETTING OFF SOME ISOLATED CONVECTION BUT THERE IS NO 
ORGANIZATION. THE PACIFIC RIDGE EXTENDS SE OVER THE AREA TO 15N120W 
WITH MOSTLY LIGHT WINDS. WINDS ALONG THE BAJA COAST ARE NWLY 15 TO 
20 KT ACCORDING TO SSMI AND QUIKSCAT IMAGERY. SOME GAP WINDS W OF 
NICARAGUA TO 20 KT AS DEPICTED BY THE MICROWAVE IMAGERY. CROSS 
EQUATORIAL SLY WINDS ARE MAINLY WHERE CONVECTON IS ACTIVE ON THE 
ITCZ. THESE AREAS ARE BETWEEN 80W AND 100W AND BETWEEN 110W AND 
125W. 

LATER DAY 1 THE UPPER TROUGH ALONG 130W BEGINS TO LIFT NE AS THE 
SURGE SHIFTS EWD. LITTLE CHANGE ELSEWHERE. ON THE SURFACE LATER DAY 
1 THE PACIFIC RIDGE STRENGTHENS SLIGHTLY AND WINDS PICK UP TO 20 KT 
IN NLY FLOW E OF 130W AND N OF 18N W OF 135W. LITTLE CHANGE 
ELSEWHERE.

FOR DAY 2 THE UPPER TROUGH BEGINS TO WASH OUT AS MID LEVEL HEIGHTS 
RISE ALONG 30N. MID LEVEL RIDGES SHOW SIGNS OF SHIFTING TOO. THE ONE 
OVER THE SW CONUS DRIFTS NWD WHILE THE ONE W OF 140W SINKS SWD TO 
ALONG 30N.  THE INVERTED TROUGH IN MID LEVELS DRIFTS W TO ALONG 110W 
MAINLY OVER SRN BAJA AND NW MEXICO. ON THE SURFACE DAY 2 GFS MODEL 
SHOWS WEAK LOW CENTERS ASSOCIATED WITH TRAVELLING TRPL WAVES BUT 
LITTLE DEVELOPMENT. THE PACIFIC RIDGE BACKS OFF A LITTLE AND WINDS 
DECREASE TO MOSTLY 15 KT.  WINDS ALONG THE BAJA COAST DIMINISH TO 10 
KT. LITTLE CHANGE ELSEWHERE.

$$
RRG