000
AXPZ20 KNHC 070915
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JUL 7 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 111W S OF 16N MOVING W 10-15 KT. THERE IS 
MID LEVEL CYCLONIC TURNING EVIDENT IN THE LATEST SATELLITE PIX 
AS WELL AS HIGH LEVEL ANTICYCLONIC FLOW. CONVECTION IS SCATTERED 
SYMMETRICALLY ABOUT THE WAVE AXIS BUT NONE IN ANY BANDS YET. 

TROPICAL WAVE ALONG 125W S OF 17N MOVING W 10-15 KT. THERE IS 
SOME EVIDENCE OF MID LEVEL CYCLONIC TURNING AND WEAK HIGH LEVEL 
OUTFLOW. CONVECTION WAS HINTING AT SOME SORT OF BAND STRUCTURE 
BUT TOPS HAVE WARMED IN THE PAST FEW HOURS AND THERE HAS BEEN NO 
FURTHER BAND DEVELOPMENT.

TROPICAL WAVE ALONG 135W S OF 17N MOVING W 10 KT. THIS WAVE MAY 
HAVE DISSIPATED. THERE IS ONLY ISOLATED CONVECTION ALONG THE 
ITCZ AND NO EVIDENCE OF A WAVE ANYMORE.

...ITCZ...
ITCZ AXIS ALONG 8N79W 7N86W 12N107W 10N123W 7N140W. SCATTERED 
STRONG CONVECTION NEAR THE COAST FROM 7N78W TO 9N85W. ISOLATED 
MODERATE NEAR 9N93W 9N102W 10N135W AND 9N137W. SCATTERED 
MODERATE AND ISOLATED STRONG FROM 8N TO 15N BETWEEN 104W AND 
118W. SCATTERED MODERATE TO STRONG CONVECTION FROM 8N TO 13N 
BETWEEN 120W AND 132W.

...DISCUSSION...

MID LEVEL RIDGE STATIONARY OVER THE SW CONUS TONIGHT WITH AN 
AXIS EXTENDING SW TO 20N130W AND 15N145W. MID LEVEL ELY FLOW S 
OF 20N. GFS MODEL SHOWING WEAK VORTICITY IN FLOW ALONG 10N 
ASSOCIATED WITH TRPL WAVES. AN UPPER LOW NEAR 17N97W HAS BEEN 
MOVING SLOWLY WWD BUT HAS BECOME STATIONARY THE PAST FEW HOURS. 
THERE WAS ISOLATED CONVECTION E OF THE CENTER AND SCATTERED 
CONVECTION WITHIN 200 NM SW OF THE CENTER..OFF THE MEXICAN 
COAST. ON THE SURFACE TONIGHT PACIFIC RIDGE EXTENDS OVER THE 
REGION TO 15N110W BUT REMAINS WEAK ALONG THE BAJA COAST WITH 
LIGHT WINDS. NE TRADES SOMEWHAT WEAKER THAN 24 HR AGO. SSMI AND 
QUIKSCAT MICROWAVE IMAGERY SHOWING MOSTLY 20 KT N OF 10N W OF 
130W. SOME WINDS TO 20 KT BLOWING THROUGH CENTRAL AMERICA W OF 
NICARAGUA. SLY WINDS TO 20 KT EVIDENT IN IMAGERY S OF CONVECTIVE 
AREAS ON ITCZ. LATEST SATELLITE IMAGERY SHOWS CONVECTIVE 
CLUSTERS BECOMING MORE ACTIVE ON ITCZ BUT 10 DEGREES N AFFORDS 
LITTLE IN THE WAY OF NATURAL VORTICITY FROM EARTH'S SPIN TO 
CRANK UP CIRCULATION..THEREFORE DEVELOPMENT IS SLOW TO OCCUR.

LATER DAY 1 LITTLE CHANGE TO MID LEVEL RIDGE OVER SW CONUS BUT 
INVERTED TROUGH DEVELOPING ALONG 108W. ON THE SURFACE LATER DAY 
1 A 1028 MB HIGH ANCHORS THE PACIFIC RIDGE WITH A CENTER NEAR 
35N140W. THE RIDGE AXIS EXTENDS SE TO 20N110W. NE TRADES TO 20 
KT MAINLY N OF 12N AND W OF 125W. BAJA WINDS CONTINUE TO BE 
LIGHT. LITTLE CHANGE ELSEWHERE.

FOR DAY 2 SOME HINT OF WEAKENING OF MID LEVEL RIDGE OVER SW 
CONUS..BUT OVERALL POSITION OF RIDGE AXIS UNCHANGED. INVERTED 
MID LEVEL TROUGH MOVING W TO NEAR 117W. ON THE SURFACE DAY 2 
LITTLE CHANGE TO PACIFIC RIDGE OR NE TRADES. BAJA WINDS REMAIN 
LIGHT. STILL SOME GAP WINDS W OF NICARAGUA TO 20 KT. CROSS 
EQUATORIAL SLY WINDS STRENGTHEN TO 20 KT S OF 8N E OF 95W. GFS 
MODEL SHOWS LITTLE DEVELOPMENT OF WEAK LOWS ALONG ITCZ.

$$
RRG