000
AXPZ20 KNHC 251528
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...                                          
TROPICAL STORM FLOSSIE IS CENTERED NEAR 15.6N 125.6W AT 25/1500 
UTC MOVING W AT 15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 
1003 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 
KT. NUMEROUS MODERATE TO STRONG CONVECTION IS NOTED WITHIN 210 
NM S SEMICIRCLE.  SOME STRENGTHENING IS FORECAST DURING THE NEXT 
48 HOURS AS FLOSSIE CONTINUES TO MOVE OVER RELATIVELY WARM WATER 
AND IN A LOW WIND SHEAR ENVIRONMENT. BASED ON THE OFFICIAL 
INTENSITY FORECAST THIS TROPICAL STORM IS EXPECTED TO REACH 
MAXIMUM SUSTAINED WINDS OF 50 KT IN ABOUT 24 HOURS. SEE LATEST 
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/ WTPZ21 
KNHC FOR MORE DETAILS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH EXTENDS FROM 08N78W TO 09N86W TO 07N110W TO 
11N112W THEN RESUMES AT 12N127W TO 11N140W. SCATTERED MODERATE 
TO STRONG CONVECTION IS NOTED FROM 07N TO 10N BETWEEN 85W AND 
90W...AND FROM 07N TO 10N BETWEEN 135W AND 138W. SCATTERED 
MODERATE CONVECTION IS FROM 07N TO 10N BETWEEN 123W AND 134W.

...DISCUSSION...                                                
ALOFT...AN ANTICYCLONE CENTERED W OF AREA NEAR 16N143W EXTENDS A 
RIDGE NE ACROSS THE WEST CENTRAL WATERS TO ABOUT 21N130W. 
MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS IS NOTED 
ON WATER VAPOR IMAGERY UNDER THE INFLUENCE OF THIS RIDGE. AN  
UPPER TROUGH EXTENDS FROM A CYCLONIC CIRCULATION JUST N OF THE 
AREA AT 33N131W TO 23N130W. ANOTHER ANTICYCLONE LOCATED OVER 
ARIZONA U.S. DOMINATES NORTHERN MEXICO...THE BAJA CALIFORNIA 
PENINSULA AND THE NE FORECAST WATERS. ANOTHER ANTICYCLONIC 
CIRCULATION IS OVER CENTRAL MEXICO NEAR 21N101W. EASTERLY WIND 
FLOW ALOFT COVERS MOST OF THE AREA E OF 115W. AN INVERTED TROUGH 
EXTENDS FROM 23N113W TO 16N115W. ANOTHER INVERTED TROUGH IS WEST 
OF FLOSSIE AND STRETCHES FROM 19N129W TO 11N132W.
 
GAP WINDS OF 20 TO 25 KT CONTINUE OVER THE GULF OF PAPAGAYO AS 
FRESH TO STRONG TRADE WIND FLOW IN THE SW CARIBBEAN FUNNELS 
THROUGH THE GAP. THE WINDS ARE GREATEST DURING THE OVERNIGHT AND 
EARLY MORNING HOURS WITH THE ASSISTANCE OF THE NOCTURNAL 
DRAINAGE FLOW. THIS PATTERN IS FORECAST TO PERSIST THROUGH 48 
HOURS. SCATTEROMETER DATA SHOWED NORTHERLY WINDS OF 20-25 KT 
ACROSS THE GULF OF TEHUANTEPEC LIKELY ASSOCIATED WITH A TROPICAL 
WAVE FORECAST TO MOVE ACROSS THE YUCATAN PENINSULA TONIGHT. NLY 
WINDS OF 20 KT WITH SEAS TO 8 FT COULD PERSIST FRI MORNING. 

CROSS EQUATORIAL SW SWELLS...WITH PERIODS IN THE 17-18 SECOND 
RANGE CAN BE FOUND OVER MOST OF THE FORECAST WATERS W OF 120W. 
THIS SWELL EVENT IS REACHING THE COASTS OF MEXICO AND CENTRAL 
AMERICA. ADDITIONAL PULSES OF SW SWELLS ARE ALREADY SPREADING 
ACROSS THE SOUTH WATERS BETWEEN 115W AND 135W. 

$$
GR