000
AXPZ20 KNHC 131501
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JUN 13 2012

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 FEATURE...
A 1006 MB LOW IS CENTERED NEAR 09N91W EMBEDDED ALONG THE MONSOON 
TROUGH N OF A FAIRLY STRONG SW MONSOONAL FLOW.  THUNDERSTORM 
ACTIVITY HAS BECOME MORE ORGANIZED THIS MORNING WITH NUMEROUS 
MODERATE SCATTERED STRONG CONVECTION WITHIN 180 NM OF LOW.  
VERTICAL SHEAR OVER THE LOW CURRENTLY IS A MODERATE 10-20 
KT...BUT IS EXPECTED TO LESSEN OVER THE NEXT DAY OR SO.  THE 
SYSTEM HAS A HIGH...60 PERCENT...CHANCE OF DEVELOPING INTO A 
TROPICAL CYCLONE IN THE NEXT 24 TO 48 HOURS AS IT MOVES NW 
TOWARD TEHUANTEPEC. ALL OF THE GLOBAL MODELS INDICATE THIS 
SYSTEM COULD DEEPEN QUICKLY ONCE THE CENTER BECOMES BETTER 
ORGANIZED. INTERESTS ALONG THE COASTS OF SOUTHEAST MEXICO SHOULD 
CLOSELY MONITOR THIS SYSTEM. IF THE SYSTEM IS UPGRADED TO A 
TROPICAL DEPRESSION LATER TODAY...THE HIGH SEAS FORECAST OF 
MAXIMUM WINDS WITH THIS SYSTEM COULD BE SIGNIFICANTLY INCREASED.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 09N84W TO LOW PRES 1006 MB NEAR 
09N91W TO 14N108W TO 07N132W. ITCZ EXTENDS FROM THAT POINT TO 
07N140W. NUMEROUS MODERATE SCATTERED STRONG FROM 07N TO 13N 
BETWEEN 82W AND 91W. 

...DISCUSSION...
THE MONSOON TROUGH TODAY REMAINS ACTIVE WITH SW MONSOONAL WINDS 
EXTENDING WEST OF 130W.  A SECONDARY LOW PRESSURE SYSTEM IS 
LIKELY TO FORM IN THE VICINITY OF 12N107W BY THURSDAY MORNING.  
HOWEVER...ALL GLOBAL MODELS WITH THE EXCEPTION OF NOGAPS...SHOW 
RELATIVELY LITTLE DEVELOPMENT OVER THE NEXT COUPLE OF DAYS.  
THIS LOW SHOULD MEANDER SLOWLY NORTH OR NORTHWESTWARD OVER THE 
NEXT SEVERAL DAYS.  THE POSSIBILITY ALSO EXISTS FOR A 
DEVELOPMENT OF A LOW NEAR THE WESTERN END OF THE MONSOON TROUGH 
IN A FEW DAYS TIME.  THE BOTTOM LINE IS THAT RELATIVELY ACTIVE 
CONDITIONS ARE RETURNING AGAIN TO THE NORTHEAST PACIFIC.

A 1030 MB HIGH NEAR 36N140W IN COMBINATION WITH LOW PRESSURE 
OVER THE WESTERN US IS FORCING 20 KT N WINDS ALONG WITH 8 FT N 
SWELL BETWEEN 120W AND 130W N OF 25N.  THE WINDS AND SEAS SHOULD 
INCREASE SLIGHTLY OVER THE NEXT TWO DAYS...BUT STAY BELOW GALE 
WINDS AND 12 FOOT SEAS.

THE GRIDDED FORECASTS WILL BE BASED UPON A BLEND OF THE 
GFS..UKMET...AND ECMWF MODELS.  THE RATHER QUICK DEVELOPMENT OF 
THE SECONDARY LOW BY THE UKMET APPEARS TO BE UNREALISTIC AT THIS 
TIME.

...GAP WINDS...
THE COMBINATION OF A MODERATE AREA OF HIGH PRESSURE OVER THE 
GULF OF MEXICO COMBINED WITH THE LOW PRESSURES OF THE MONSOON 
TROUGH AND THE DEVELOPING LOW ARE INDUCING A 20 TO 25 KT 
TEHUANTEPEC GAP WIND EVENT.  AS THE HIGH PRESSURE OVER THE GULF 
OF MEXICO IS LIKELY TO WEAKEN SHORTLY...THE GAP WINDS SHOULD 
DROP BELOW OUR 20 KT THRESHOLD BY TOMORROW MORNING.

$$
LANDSEA