000
AXPZ20 KNHC 181505
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JUL 18 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 
1500 UTC.

...SPECIAL FEATURE...
TROPICAL STORM COSME AT 15.3N 138.9W AT 18/1500 UTC MOVING W AT 12 
KT. ESTIMATED MINIMUM CENTRAL PRES IS 1004 MB. MAXIMUM SUSTAINED 
WINDS ARE 35 KT GUSTS TO 45 KT. THE CENTER IS PARTIALLY EXPOSED NE OF
CONVECTIVE BURST NEAR 15N139W. FOR ADDITIONAL DETAILS REFER TO LATEST
FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC.

 ...TROPICAL WAVES...
TROPICAL WAVE ALONG 87W N OF 4N MOVING W 15 KT. MINIMAL CONVECTION 
ASSOCIATED WITH THIS WAVE. BROAD CYCLONIC TURNING IS NOTED BETWEEN 
85W AND 94W WITH A 1010 MB LOW PRES ANALYZED AT 7N89W.
  
TROPICAL WAVE ALONG 107W N OF 7N MOVING W 10 KT. STRONG PERSISTENT 
CONVECTION IS ASSOCIATED WITH THE WAVE ALONG THE COAST OF MEXICO.

TROPICAL WAVE ALONG 122W FROM 3N TO 15N MOVING W 12 KT. A FEW 
CONVECTIVE CLUSTERS ARE OBSERVED EAST OF THE WAVE AXIS.

...ITCZ...
DISCONTINUOUS AXIS 8N78W 9N86W 6N90W 9N98W 18N102W 15N110W 11N120W 
11N125W 14N129W 6N140W. SCATTERED MODERATE CONVECTION N OF 5N E OF 
85W. SCATTERED MODERATE TO STRONG CONVECTION N OF 16N BETWEEN 102W 
AND 108W. SCATTERED MODERATE FROM 9N TO 14N BETWEEN 112W AND 120W. 

...DISCUSSION...
TROPICAL STORM COSME REMAINS UNDER MODERATE UPPER LEVEL SHEAR AND 
ITS CONVECTION IS DISPLACED ABOUT 45 NM SW OF THE LOW LEVEL CENTER. 
IT WAS BETWEEN QUIKSCAT PASSES LAST NIGHT SO SURROUNDING 20-33 KT 
WINDS ARE ESTIMATED. COSME CONTINUES MOVING WEST AND WILL EXIT THE 
DISCUSSION AREA THIS AFTERNOON OR TONIGHT. 

THE MOST SIGNIFICANT FEATURE ELSEWHERE IS A TROUGH THAT EXTENDS SW 
FROM THE COAST OF MEXICO NEAR 19N104W TO AROUND 10N117W. THIS TROUGH 
HAS FRACTURED THE ITCZ BETWEEN 102W AND 110W. FRESH SW WINDS S OF THE
TROUGH AXIS CONVERGING NEAR THE MEXICAN COAST ARE PRODUCING A LARGE 
AREA OF ACTIVE CONVECTION. THE DEEP CONVECTION IS MASKING LOW LEVEL 
FEATURES AND ITS PROXIMITY TO THE COAST MAKE MICROWAVE SATELLITE DATA
UNAVAILABLE. IT IS THEREFORE DIFFICULT TO DETERMINE IF A LOW PRESSURE
CENTER IS DEVELOPING OR NOT. ALTHOUGH THE CONVECTION SHOULD PERSIST 
FOR ANOTHER DAY OR SO...ANY INTENSIFICATION IS UNLIKELY.

A QUIKSCAT PASS AT 12Z REVEALED A MONSOON TROUGH EXTENDING WSW FROM 
COSTA RICA NEAR 10N85W TO 7N90W TO 7N95W. WEAK CYCLONIC CIRCULATIONS 
ARE EMBEDDED IN THE TROUGH NEAR 9N87W AND 8N89W. THE CONSENSUS OF 
GLOBAL FORECAST MODELS APPEARS TO SLOW DEVELOPMENT...WITH THE ECMWF 
THE MOST AGGRESSIVE. 

$$
MUNDELL