000
AXPZ20 KNHC 111521
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JUL 11 2007

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 OVER CENTRAL AMERICA ALONG 85W N OF 7N MOVING W 
NEAR 15 KT. THERE IS LITTLE STRUCTURE EVIDENT ON SATELLITE 
IMAGERY. NEARBY SHOWER AND TSTM ACTIVITY...MAINLY OVER THE SW 
CARIB...IS LIKELY MORE TIED TO THE ITCZ AND UPPER LEVEL FEATURES.

TROPICAL WAVE IS ALONG 97W/98W N OF 7N MOVING W 10-15 KT. THIS 
WAVE HAS BECOME BETTER DEFINED TODAY WITH A LARGE AREA...ABOUT 6 
DEGREES EITHER SIDE OF THE WAVE AXIS...OF LOW TO MID LEVEL 
TURNING. CONVECTION IS ORGANIZED IN TWO BATCHES...ONE TO THE NE 
OF THE AXIS FROM 12N TO 15N BETWEEN 94W AND 97W...WHICH INCLUDES 
A PORTION OF THE GULF OF TEHUANTEPEC. THE OTHER IS EMBEDDED IN 
THE ITCZ FROM 10N-12N BETWEEN 99W-103W. 

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N78W 10N84W 11N96W 12N112W 10N130W 
8N140W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM S OF AXIS 
E OF 83W. SCATTERED MODERATE FROM 10N-15N BETWEEN 93W-103W ALSO 
FROM 7N-13N BETWEEN 112W-123W.

...DISCUSSION...

UPPER TROUGHING...ASSOCIATED WITH A LOW PRES SYSTEM N OF THE 
REGION...COVERS THE NW PORTION OF THE AREA. A SPRAWLING UPPER 
HIGH IS CENTERED TO IT'S S NEAR 15N135W. THIS OVERALL CONFLUENT 
PATTERN IS PRODUCING ABUNDANT DRY AIR ALOFT S OF 24N W OF 123W. 
THIS STABLE AIR IS HELPING TO SUPPRESS WIDESPREAD DEEP 
CONVECTION ALONG THE ITCZ W OF 125W. FARTHER E...THE MAIN MID TO 
UPPER FEATURE IS AN HIGHLY N-S STRETCHED RIDGE CENTERED OVER THE 
MEXICAN PLATEAU ALONG 106W. THERE IS A FAIR AMOUNT OF MOISTURE 
ALOFT ROTATING AROUND THE RIDGE...PROVIDING A FAIR ENVIRONMENT 
...FROM A MOISTURE VANTAGE POINT...FOR THE IMPROVING TROPICAL 
WAVE ALONG 97W/98W. LARGE CLUSTERS OF SCATTERED MODERATE 
CONVECTION ALONG THE ITCZ BETWEEN 93W AND 103W ARE BEING 
ENHANCED TO THE S OF AN UPPER LOW AND BY A LOW-LEVEL TROUGH 
ANALYZED ALONG 112W FROM 8N-15N.
 
THE REMNANTS OF TROPICAL DEPRESSION FOUR-E IS SPINNING NEAR 
20N125W. THIS MORNING'S QSCAT CYCLE MISSED THIS AREA...BUT BASED 
ON LAST NIGHT'S PASS AND AN EARLY MORNING ASCAT PASS THERE IS 
LIKELY STILL A SMALL AREA OF WINDS IN THE 20-25 KT RANGE NEAR 
THE SHALLOW CENTER. THIS WEAK SYSTEM IS EXPECTED TO OPEN AS A 
TROUGH OVER THE NEXT DAY OR SO. OTHERWISE...SFC WINDS ACROSS THE 
SUBTROPICAL PACIFIC ARE PRETTY LIGHT DUE TO THE UNUSUAL WEAK 
PRES GRADIENT. SLIGHTLY STRONGER NLY FLOW IS NEAR THE BAJA COAST 
WHERE THERE IS SOME TIGHTENING IN THE GRADIENT BETWEEN A 1018 MB 
HIGH PRES NEAR 29N120W AND INVERTED TROUGHING OVER THE SW U.S.

...GAP WINDS...
WHILE THIS MORNING'S 1140 UTC QSCAT PASS DID NOT SHOW MUCH WINDS 
IN THE GULF OF PAPAGAYO...MODELS ARE IN GOOD AGREEMENT OF THE 
PULSING OF THIS STRONG FLOW CROSSING FROM THE W CARIB INTO THE 
EPAC. LOOKS LIKE THE WINDS SHOULD PEAK IN ABOUT 24 HOURS AND 
THEN DECREASE. 

$$
CANGIALOSI