Prognostic Meteorological Discussion
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FXSA20 KWBC 231724
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SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
123 PM EDT WED APR 23 2014

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

MODEL DISCUSSION (VALID FROM 23 APRIL 00UTC): GLOBAL MODELS AND
ENSEMBLE MEMBERS AGREE FAIRLY WELL IN FORECAST EVOLUTION THROUGH
72-96 HRS. SOME DISCREPANCIES IN THE DETAILS ON THE SOUTHERN
STREAM APPEAR AFTERWARDS.

OVER THE CONTINENT...MOISTURE REMAINS BLOCKED TO THE NORTH OF
15-20S. THIS IS LIMITING ACCUMULATIONS IN MID-SECTIONS AND
SOUTHERN SECTIONS OF THE CONTINENT. INITIALLY...EXPECTING SOME
ENHANCEMENT TO PERSIST ACROSS SOUTHEASTERN BRASIL AS AN UPPER
TROUGH MOVES EASTWARD ACROSS MATO GROSSO/MATO GROSSO DO SUL INTO
THE REGION. THIS WILL SUSTAIN ACTIVE DIURNAL CONVECTION ACROSS
MINAS GERAIS/NORTHERN SAO PAULO/RIO DO JANEIRO THROUGH DAY 02.
LARGEST AMOUNTS ARE EXPECTED LOCALLY OVER THE SERRA DO MAR ON DAY
01...AS ENHANCED LOW-LEVEL CONVERGENCE IN DEEP MOISTURE POOL
ENHANCE ACTIVITY. FOCUS WILL GRADUALLY PROGRESS NORTHEASTWARD...TO
CENTER ACROSS ESPIRITO SANTO-BAHIA-ALAGOAS-SERGIPE BY LATE CYCLE.

OTHER REGION WITH ACTIVE CONVECTION WILL BE EXTREME NORTHWESTERN
AMAZONIA FROM NORTHERN BRASIL/NORTHERN PERU/ECUADOR INTO COLOMBIA
AND SOUTHERN VENEZUELA. ACTIVE CONVECTION WILL PRODUCE ISOLATED TO
SCATTERED AMOUNTS IN THE ORDER OF 25-50MM/DAY THROUGH THE CYCLE.

IN THE SOUTHERN CONE...LONG WAVE PATTERN IS DOMINATING. THE
LIMITING FACTOR WILL BE LACK OF AVAILABLE MOISTURE FOR HEAVY
PRECIPITATION. LARGE MID-UPPER TROUGHS ARE MOVING VERY SLOWLY.
TROUGH AND SURFACE FRONTS WILL ARRIVE IN SOUTHERN CHILE ON DAY 03
TO PRODUCE MAXIMA OF 15-20MM/DAY. EXPECTING STILL ACTIVE
CONDITIONS ON DAY 04 WITH ACCUMULATIONS OF 10-15MM/DAY EXTENDING
AS FAR NORTH AS CONCEPCION.

ITA...SENAMHI (PERU)
FERNANDES...INMET (BRASIL)
GALVEZ...WPC (USA)
$$




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