000
AXPZ20 KNHC 291554
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT SEP 29 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.
  
...SPECIAL FEATURE...

TROPICAL DEPRESSION FOURTEEN-E NEAR 15.3N 111.7W 1006 MB AT 1500 
UTC SEP 29 MOVING WNW OR 285 DEG AT 10 KT. MAXIMUM SUSTAINED 
WINDS 30 KT GUSTS TO 40 KT. CLOUD TOP TEMPERATURES HAVE WARMED 
SLIGHTLY OVER THE PAST THREE HOURS INDICATING THE CONVECTION HAS 
WEAKENED SOMEWHAT. HOWEVER MODERATE TO STRONG CONVECTION IS 
STILL EVIDENT ON SATELLITE IMAGERY WITHIN 90 NM OF THE CENTER. 
IN ADDITION...A BAND OF CONVECTION FED BY GOOD OUTFLOW ALOFT IS 
DEVELOPING WITHIN 180 NM TO THE N OF THE CENTER...WITHIN 60 NM 
OF A LINE FROM 18N111W TO 16N113W.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 121W S OF 16N MOVING W 10 KT. NO CONVECTION 
IS NOTED WITH THIS WAVE. THE WAVE IS MOVING INTO AN REGION VERY 
DRY MID AND UPPER LEVELS WITH NLY SHEAR ALOFT...UNFAVORABLE FOR 
SIGNIFICANT CONVECTIVE DEVELOPMENT.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE...AXIS 7N77W 8N100W 13N114W 
10N123W. SCATTERED MODERATE ISOLATED STRONG WITHIN 30 NM OF 
7N78W AND WITHIN 30 NM EITHER SIDE OF LINE 7N97W 12N108W. 
SCATTERED MODERATE FROM 9N TO 16N BETWEEN 114W AND 122W.

SCATTERED MODERATE ISOLATED STRONG WITHIN 60 NM OF MEXICAN COAST 
FROM 97W TO 101W AND FROM 17N TO 22N BETWEEN 105W AND 109W. 

...DISCUSSION...

E OF 120W...BROAD UPPER ANTICYCLONE CENTERED OVER THE FAR 
WESTERN GULF OF MEXICO IS THE DOMINANT UPPER FEATURE. THIS IS 
MAINTAINING MODERATE ELY SHEAR OVER E PACIFIC WATERS S OF 18N. 
AT THE SURFACE...LIGHT TO MODERATE SWLY FLOW S OF THE ITCZ IS 
CONVERGING WITH GENERALLY LIGHT ELY FLOW N OF THE ITCZ RESULTING 
IN VERY MODEST LOW LEVEL CONVERGENCE. THE WEAK LOWER CONVERGENCE 
AND MODERATE SHEAR ALOFT ARE INHIBITING CONVECTIVE DEVELOPMENT 
ALONG THE ITCZ E OF 100W. DIVERGE ALOFT ON THE SW SIDE OF THE 
UPPER ANTICYCLONE...COMBINED WITH FRESH SWLY WINDS DEPICTED IN 
SCATTEROMETER DATA S OF THE ITCZ W OF 100W...ARE PROVIDING 
SUFFICIENT LIFT TO SUPPORT DEVELOPMENT OF T.D. 14-E NEAR 
15N112W. INTENSIFICATION TO TROPICAL STORM STRENGTH IS EXPECTED 
IN THE SHORT TERM WHILE 14-E REMAINS IN THIS FAVORABLE 
ENVIRONMENT. IT WILL LIKELY WEAKEN STARTING AFTER TOMORROW 
HOWEVER AS IT MOVES INTO A REGION OF DRIER AND MORE STABLE AIR 
WITH INCREASING SHEAR ALOFT. ELSEWHERE MODERATE TO FRESH NLY 
WINDS WILL PERSIST IN THE GULF OF TEHUANTEPEC AREA AT LEAST 
THROUGH TOMORROW...THE RESULT OF HIGHER DENSITY BOUNDARY LAYER 
AIR FUNNELING OUT OF THE GULF OF MEXICO. FRESH NLY FLOW WILL 
DIMINISH OFF THE NRN BAJA COAST...ON THE PERIPHERY OF HIGH PRES 
TO THE NW.

W OF 120W...UPPER TROUGH EXTENDS FROM 30N120W TO 22N132W. UPPER 
RIDGE AXIS IS SITUATED TO THE W OF THE TROUGH. THE NWLY FLOW 
ALOFT BETWEEN THE TWO SYSTEMS IS BRINGING MUCH DRIER AND MORE 
STABLE AIR OVER THE REGION W OF 120W...SUPPRESSING CONVECTIVE 
DEVELOPMENT. A SURFACE RIDGE 1025 MB IS CENTERED TO THE NW OF 
THE AREA AND IS MOVING GRADUALLY SE. TRADE FLOW IS TO INCREASE 
SLIGHTLY BETWEEN THE HIGH PRES AND THE DEVELOPING T.D. 14-E.
$$

CHRISTENSEN