000
AXPZ20 KNHC 262138
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC FRI JUL 26 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 FLOSSIE IS CENTERED NEAR 16.3N 133.3W AT 26/2100 
UTC OR ABOUT 1200 NM E OF HILO HAWAII MOVING WNW AT 17 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. MAXIMUM SUSTAINED 
WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION IS WITHIN 120 NM W AND NW QUADRANTS. 
SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 09N TO 17N 
BETWEEN 129W AND 133W...AND FROM 16N TO 21N BETWEEN 130W AND 
137W. FLOSSIE IS FORECAST TO CROSS OVER INTO THE CENTRAL PACIFIC 
OCEAN ON SATURDAY. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/ 
WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. 

...TROPICAL WAVES...                                     
TROPICAL WAVE EXTENDS FROM 13N92W TO 21N92W MOVING W AT 10 KT. 
THE WAVE COINCIDES WITH GLOBAL MODEL 700 MB TROUGHING OVER 
SOUTHERN MEXICO WITH A VORTICITY MAXIMUM IN THE VICINITY OF 
17N92W. THE WAVE WILL LIKELY ENHANCE DRAINAGE FLOW THROUGH THE 
CHIVELA PASS AND INTO THE GULF OF TEHUANTEPEC LATER TONIGHT INTO 
EARLY SATURDAY MORNING. THE NORTHERLY FLOW COULD BRIEFLY REACH 
20 KT WITH SEAS TO NEAR 8 FT. THEREAFTER...THE WAVE WILL LIKELY 
LOSE IDENTITY ACROSS SOUTHERN MEXICO BY LATE SATURDAY.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N84W TO 10N108W TO 
08N115W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
14N135W TO 08N140W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 
11N BETWEEN 78W AND 83W...FROM 07N TO 12N BETWEEN 83W AND 
90W...FROM 07N TO 13N BETWEEN 93W AND 101W...AND FROM 06N TO 11N 
BETWEEN 104W AND 112W. WIDELY SCATTERED MODERATE CONVECTION IS 
FROM 11N TO 17N BETWEEN 119W AND 125W.

...DISCUSSION...                                              
              
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH AXIS ENTERS 
THE FORECAST REGION NEAR 30N133W AND CONTINUES SW TO A BASE NEAR 
24N139W. MODERATE TO STRONG SUBSIDENCE AND A DRY AIR MASS 
ACCOMPANIES THIS TROUGH COVERING A LARGE PORTION OF THE NW 
CORNER OF THE DISCUSSION AREA. THIS AIRMASS WILL LIKELY AFFECT 
TROPICAL STORM FLOSSIE OVER THE NEXT FEW DAYS AND CONTRIBUTE TO 
THE WEAKENING FORECAST TREND AFTER EARLY SUNDAY AND INTO EARLY 
NEXT WEEK. FARTHER EAST...AN ANTICYCLONIC CIRCULATION IS 
CENTERED INLAND OVER NORTHWESTERN MEXICO NEAR 31N109W THAT 
DOMINATES THE FLOW OVER MUCH OF MEXICO AND THE ADJACENT COASTAL 
WATERS N OF 15N E OF 119W. EASTERLY WIND FLOW ALOFT COVERS MOST 
OF THE AREA S OF 15N E OF 120W. EMBEDDED WITHIN THIS FLOW 
ALOFT...AN INVERTED TROUGH AXIS EXTENDS FROM NE OF THE GULF OF 
TEHUANTEPEC REGION NEAR 21N89W TO NEAR 14N96W. 

THE PRESSURE GRADIENT BETWEEN FLOSSIE AND HIGH PRESSURE CENTERED 
TO THE NORTH WILL MAINTAIN A LARGE AREA OF NE TO E WINDS IN THE 
20 TO 30 KT RANGE ON THE NORTHERN PERIPHERY OF THE STORM. RECENT 
SCATTEROMETER DATA INDICATES THAT THESE WINDS ARE WITHIN 360 NM 
OF THE STORM CENTER.
 
NE TO E 15-20 KT WINDS WILL CONTINUE TO PULSE ACROSS THE GULF OF 
PAPAGAYO LATER TONIGHT INTO THE EARLY MORNING HOURS RESULTING IN 
COMBINED SEAS OF 6-8 FT IN MIXED SHORT PERIOD E SWELL AND LONG 
PERIOD SW SWELL. 

CROSS EQUATORIAL SE AND SW SWELLS RESULTING IN COMBINED SEAS TO 
9 FT CONTINUE ACROSS THE DEEP TROPICS...GENERALLY S OF 05N 
BETWEEN 107W AND 134W. THIS SWELL EVENT IS FORECAST TO PROPAGATE 
GENERALLY NORTHWARD ACROSS THE SOUTHERN WATERS DURING THE 
UPCOMING WEEKEND REACHING AS FAR N AS A LINE FROM 20N120W TO 
02N80W BY SUNDAY.

$$
HUFFMAN