000
AXPZ20 KNHC 232126
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC FRI AUG 23 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 
2100 UTC.
                                    
...SPECIAL FEATURES...                                           
 
TROPICAL STORM IVO CENTERED NEAR 19.5N 111.8W AT 23/2100 UTC OR 
265 MI SSW OF CABO SAN LUCAS MEXICO MOVING N AT 5 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND 
SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC FORECAST/ 
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE 
DETAILS. NUMEROUS MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 210 NM IN THE E SEMICIRCLE...AND NUMEROUS MODERATE AND 
SCATTERED STRONG CONVECTION IS WITHIN 420 NM IN THE SE QUADRANT 
OF IVO.

IVO IS EXPECTED TO INTENSIFY SLIGHTLY DURING THE NEXT 24 HOURS 
BEFORE IT ENCOUNTERS COLDER WATER W OF BAJA CALIFORNIA WHICH 
WILL CAUSE IT TO GRADUALLY WEAKEN INTO A REMNANT LOW BY SUN 
AFTERNOON. A VERY LONG FETCH OF SW WINDS ASSOCIATED WITH THE 
TROPICAL CYCLONE IS ALLOWING FOR COMBINED SEAS TO BUILD TO 16 FT 
SE OF THE CENTER. MODEL GUIDANCE SHOWS HIGH SEAS REACHING WELL 
NORTHWARD INTO THE GULF OF CALIFORNIA BEGINNING TONIGHT THROUGH 
SUN...THE RESULT OF S-SE WINDS EXTENDING THE FETCH OF SOUTHERLY 
SWELL UNUSUALLY FAR NORTHWARD INTO THE GULF. A SMALL DEVIATION 
IN WIND DIRECTION OR RAPID WEAKENING WILL CAUSE THESE HIGH SEAS 
TO BARELY REACH N OF 24N IN THE GULF...SO UNCERTAINTY WITH 
RESPECT TO ANY ASSOCIATED OUTER WINDS AND LARGE SEAS REMAINS.

IN ANY CASE...LARGE SURF WILL IMPACT THE SOUTHERN BAJA 
CALIFORNIA PENINSULA TONIGHT WITH TROPICAL MOISTURE STREAMING 
NORTHWARD OVER NW MEXICO THROUGH THIS WEEKEND BRINING THE 
POTENTIAL FOR VERY HEAVY RAINFALL AND FLASH FLOODING.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...       

THE MONSOON TROUGH EXTENDS FROM 09N79W TO 12N103W THEN RESUMES 
AT LOW PRES NEAR 14N126W TO 12N138W. THE ITCZ AXIS EXTENDS FROM 
12N138W TO BEYOND 11N140W. SCATTERED MODERATE CONVECTION IS FROM 
04N TO 08N BETWEEN 81W AND 85W...FROM 07N TO 13.5N BETWEEN 94W 
AND 99W...WITHIN 240 NM IN THE SW QUADRANT OF THE AREA OF LOW 
PRES...AND ALSO WITHIN 120 NM S OF THE MONSOON TROUGH BETWEEN 
131W AND 134W.

...DISCUSSION... 

AT THE UPPER LEVELS...A LARGE AND BROAD ANTICYCLONE HAS SHIFTED 
W OF THE AREA TO NEAR 21N145W...HOWEVER VERY DRY AND STABLE AIR 
EXTENDS E OF IT ACROSS THE DISCUSSION WATERS N OF 14N W OF 130W. 
A TROUGH EXTENDS INTO THE N CENTRAL WATERS FROM NEAR 32N120W 
THROUGH 25N122W TO 16N128W WITH VERY DRY AND STABLE AREA W OF 
THE TROUGH TO 130W. SW FLOW CONTINUES TO ADVECT MOISTURE AND 
CONVECTIVE DEBRIS FROM THE DEEP TROPICS TO THE NE ACROSS FAR NW 
MEXICO OUT AHEAD OF TROPICAL STORM IVO. ELSEWHERE ALOFT... 
MAINLY ZONAL EASTERLY WINDS COVER THE REMAINDER OF THE 
DISCUSSION WATERS.

ELSEWHERE AT THE SURFACE...1021 MB HIGH PRES IS NEAR 33N133W 
WITH A RIDGE AXIS EXTENDING SE TO NEAR 27N118W. GENTLE TO 
MODERATE WINDS DOMINATE W OF A LINE FROM 24N111W TO 10N140W 
ALONG WITH 4-7 FT SEAS. SIMILAR CONDITIONS COVER THE REMAINDER 
OF THE DISCUSSION WATERS...OUTSIDE OF TROPICAL STORM IVO 
DISCUSSED ABOVE. 

A TROPICAL WAVE MOVING THROUGH THE FAR W CARIBBEAN MAY INDUCE 
ENHANCED WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC AS FRESH NORTHERLY WINDS TONIGHT AND SAT...WITH SEAS 
BUILDING TO 6-7 FT BY EARLY SAT MORNING.
 
$$
LEWITSKY