000
AXPZ20 KNHC 122153
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC FRI JUL 12 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...   
     
THE MONSOON TROUGH AXIS EXTENDS W FROM THE NW COAST OF COLOMBIA 
AT 10N76W ACROSS THE CARIBBEAN BETWEEN 11N-12N CROSSING SOUTHERN
NICARAGUA TO TO THE PACIFIC COAST OF NICARAGUA AT 11N86W...
CONTINUING WNW TO 13.5N97W THEN DIPPING WSW TO 13N103W WHERE 
SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTERTROPICAL
CONVERGENCE ZONE. THIS ITCZ THEN CONTINUES W TO 14N120W...THEN
TURNS SW TO BEYOND 09N140W. ISOLATED MODERATE TO STRONG CONVECTION
IS NOTED WELL S OF THE MONSOON TROUGH OVER THE PACIFIC WATERS N OF
A LINE FROM THE COLOMBIAN COAST AT 02N78W TO 09N102W. SCATTERED
MODERATE ISOLATED STRONG CONVECTION IS OBSERVED S OF THE ITCZ WITHIN 
150 NM EITHER SIDE OF A LINE FROM 10N108W TO 08N121W TO 12N125W TO
11N134W WITH A SMALL CLUSTER ALONG THE ITCZ AT 09.5N137.5W.

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED N OF THE 
MONSOON TROUGH AND ITCZ WITHIN 240 NM OF COAST OF MEXICO FROM 102W
TO 106W. 

...DISCUSSION... 

AN UPPER CYCLONE IS AT 34N136W WITH A NEGATIVE TILT TROUGH 
EXTENDING SE INTO THE NW PORTION OF THE DISCUSSION AREA ALONG
30N129W TO 25N125W. AN UPPER RIDGE EXTENDS E ALONG 26N140W TO
15N113W TO 11N104W. THESE UPPER LEVEL FEATURES COMBINE TO DRY
OUT THE UPPER LEVELS OF THE DISCUSSION AREA TO THE N OF 16N W
OF 113W.

A BROAD INVERTED UPPER TROUGH...ACCOMPANIED BY DRY AIR ALOFT... 
DOMINATES THE DEEP TROPICS S OF 07N BETWEEN 120W-137W WITH THE 
PATTERN SHIFTING W WITH TIME. THE UPPER FLOW IS SLIGHTLY 
DIFFLUENT S OF THE PREVIOUSLY MENTIONED SUBTROPICAL UPPER RIDGE 
AND TO THE N OF THIS BROAD TROUGH...AND IS ENHANCING THE 
CONVECTION PREVIOUSLY DESCRIBED TO THE W OF 110W. THE RESULTANT
DEBRIS MOISTURE HAS BECOME DENSE OVER THE PAST FEW HOURS AND IS
FANNING OUT ACROSS THE TROPICS FROM 07N-14N BETWEEN 110W-121W
AND WITHIN A FEW HUNDRED OF THE MATURE CONVECTIVE CLUSTERS TO 
THE W OF 121W.

AN UPPER CYCLONE IS CENTERED AT 19N108W WITH UPPER DIFFLUENCE OVER
ITS E SEMICIRCLE ENHANCING THE NOW DISSIPATING CONVECTION PREVIOUSLY
DESCRIBED ALONG THE MEXICAN COAST NEAR 18N104W. THE DENSE DEBRIS
MOISTURE IS SPREADING NE OVER INLAND MEXICO TO 20N100W.    

A SMALL UPPER ANTICYCLONE IS CENTERED OVER HONDURAS WITH AN UPPER
RIDGE EXTENDING SE TO 10N82W. THE ASSOCIATED WEAK UPPER DIFFLUENCE 
IS ENHANCING THE CONVECTION PREVIOUSLY DESCRIBED TO THE E OF 100W.
THE DEBRIS MOISTURE IS ADVECTED S OVER THE DEEP TROPICS TO THE
E OF 100W WITH MOISTURE NOW SPREADING ACROSS THE EQUATOR NEAR 98W. 

AT THE LOW LEVELS A RIDGE EXTENDS FROM 30N140W TO 14N107W. NE 
TRADES AT 15-20 KT ACROSS THE TROPICS FROM 11N-18N W OF 130W 
WITH SEAS OF 6-7 FT IN MIXING NE AND S SWELL.  

SOUTHERLY CROSS EQUATORIAL SWELL IS MAINTAINING COMBINED SEAS OF 
6-8 FT ACROSS THE TROPICAL WATERS FROM 05N-10N BETWEEN 112W-120W. 
THESE SWELLS ARE FORECAST TO CONTINUE TO SUBSIDE WITH COMBINED 
SEAS BELOW 8 FT TONIGHT.

MODEL GUIDANCE IS BEGINNING TO FAVOR A WEAK CYCLONIC TURNING 
CURRENTLY ALONG THE MONSOON TROUGH AXIS NEAR 11N91W...AND 
MAINTAINS A BROAD BUT WEAK CYCLONIC CIRCULATION SHIFTING W TO
NEAR 12N100W MON NIGHT...AND NEAR 12N105W LATE WED.   
 
$$ 
NELSON