000
AXPZ20 KNHC 131003
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...
ASCAT SCATTEROMETER DATA AT 0250 UTC SHOWS A CYCLONIC CIRCULATION
EMBEDDED IN THE MONSOON TROUGH CENTERED NEAR 09N89W. SAT IMAGERY 
SHOWS CONVECTIVE BANDS AND WEAK CYCLONIC TURNING A LITTLE FURTHER
WEST NEAR 09N90W. SURFACE OBSERVATIONS SEVERAL HOURS AGO SHOWED A
BROAD LOW WITH 20 KT WINDS AWAY FROM THE CENTER. THE DISTURBANCE 
IS LOCATED IN AN AREA OF LOW VERTICAL SHEAR AND ANTICYCLONIC FLOW
ALOFT THAT IS FAVORABLE FOR FURTHER DEVELOPMENT. IT HAS A MEDIUM 
50 PERCENT CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE IN THE 
NEXT 24 TO 48 HOURS AS IT MOVES NW TOWARD TEHUANTEPEC. GLOBAL 
MODELS INDICATE THIS SYSTEM COULD DEEPEN QUICKLY ONCE THE CENTER 
BECOMES BETTER ORGANIZED. INTERESTS ALONG THE COASTS OF GUATEMALA
AND SOUTHEAST MEXICO SHOULD CLOSELY MONITOR THIS SYSTEM. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 10N85W TO A DEVELOPING LOW PRES 
1006 MB NEAR 09N90W TO 12N99W TO 14N111W TO 07N128W. THE ITCZ 
EXTENDS FROM 07N130W TO 07N140W. NUMEROUS MODERATE SCATTERED 
STRONG CONVECTION...ASSOCIATED WITH THE DEVELOPING LOW...IS FROM 
08N TO 11N BETWEEN 83W AND 93W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION FROM 07N TO 10N BETWEEN 96W AND 99W. SCATTERED 
MODERATE CONVECTION FROM 06N TO 10N BETWEEN 103W AND 118W.

...DISCUSSION...
THE MOST DISTINCTIVE FEATURE ACROSS THE EAST PAC BASIN TODAY IS 
VERY ACTIVE CONVECTION ASSOCIATED WITH A DEVELOPING TROUGH OF LOW
PRES ALL ALONG THE NEAR-EQUATORIAL CONVERGENCE ZONE EAST OF 120W.
W-SW WINDS ARE INTENSIFYING S OF THE MONSOON TROUGH AND FRESH E 
WINDS DOWNSTREAM OF THE GULF OF PAPAGAYO ARE HELPING SPIN UP THE 
DEVELOPING LOW NEAR 09N90W BY ADDING CYCLONIC VORTICITY TO THE NE
SEMICIRCLE OF THE CIRCULATION. DIFFLUENT UPPER LEVEL WINDS ALONG 
9N-10N ARE HELPING MAINTAIN DEEP CONVECTION OVER A WIDE SWATH OF 
THE NORTHEAST PACIFIC. A WEAK HIGH PRES RIDGE EXTENDS ACROSS THE 
NW PORTION OF THE DISCUSSION AREA TO AROUND 21N120W. MODERATE TO 
FRESH N WINDS ARE FOUND IN THE NORTH-CENTRAL PORTION WITH SEAS 7 
TO 8 FT N OF 26N BETWEEN 130W-135W. LIGHT TO MODERATE NE TRADES 
ARE LOCATED N OF THE ITCZ AXIS W OF 120W.

EXPECT THE MONSOON TROUGH TO REMAIN QUITE ACTIVE WITH WIDESPREAD 
DEEP CONVECTION AND MULTIPLE CYCLONIC CIRCULATIONS EMBEDDED IN 
THE LOW PRES TROUGH. GFS MODEL SHOWS GOOD CONSISTENCY OVER THE 
PAST 24-36 HOURS AND IS IN FAIRLY GOOD AGREEMENT WITH BOTH ECMWF 
AND UKMET GLOBAL MODELS. PRIMARY DIFFERENCE BETWEEN THE VARIOUS 
MODELS IS STRENGTH AND MOTION OF THE ANCHOR LOW CENTERED NEAR 9N 
90W OVER THE NEXT 2-3 DAYS...BUT THE GENERAL TREND IS DEEPENING 
WHILE THE LOW MOVES NNW TOWARD SOUTHERN MEXICO NEAR TEHUANTEPEC.

LONG RANGE PROGS SHOW AN ACTIVE MONSOON TROUGH EXTENDING FURTHER 
E ACROSS CENTRAL AMERICA LATER THIS WEEK THROUGH THE WEEKEND... 
WHICH POSES A SERIOUS DANGER FOR EXTENDED PERIODS OF HEAVY RAIN 
IN THE REGION AND A GREATER RISK FOR WIDESPREAD FLOODING.

$$
MUNDELL