SOUTH AMERICA FORECAST DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
303 PM EDT THU JUL 18 2024

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

SOUTH AMERICAN FORECAST BULLETIN FOR 18 JUL 2024 AT 1900 UTC:

ON THURSDAY...MOST OF THE SOUTHERN CONE IS EXPECTED TO BE POST
COLD FRONT...FROM CENTRAL ARGENTINA AND TO THE SOUTH. A COLD FRONT
IS EXPECTED OVER VALPARAISO AND METROPOLITAN SANTIAGO...INTO THE
CENTRAL PORTIONS OF ARGENTINA AND EXITING THROUGH SOUTHERN BUENOS
AIRES. AN UPPER LEVEL TROUGH WEST OF NORTHERN CHILE. THE WESTERN
PORTION OF THE UPPER LEVEL TROUGH IS DEEPENING THE TROUGH AND IT
IS EXPECTED TO BECOME A CUT OFF LOW BY FRIDAY EVENING. ON
THURSDAY...EXPECT ANOTHER FRONTAL SYSTEM TO ADVANCE INTO
MAGALLANES-CHILE AND THE SOUTHERN PATAGONIA IN
ARGENTINA...FAVORING SCATTERED RAIN/SNOW MIX IN AYSEN AND
MAGALLANES...WITH TRACE AMOUNTS OF ACCUMULATIONS. IN BUENOS
AIRES...THE SALLJ CONTINUES TO TRANSPORT MOISTURE INTO NORTHERN
ARGENTINA AND FAVOR MAXIMA OF 15-20MM. THE HIGHER ELEVATIONS OF
METROPOLITAN SANTIAGO AND O'HIGGINS CAN EXPECT SNOWFALL MAXIMA OF
15CM. ON FRIDAY...A FRONTAL SYSTEM IS MOVING INTO URUGUAY AND
NORTHERN ARGENTINA...WHERE MOISTURE IS EXPECTED TO BE PRESENT BUT
FAVOR MAXIMA OF 15MM IN URUGUAY AND NORTH-CENTRAL ARGENTINA. IN
SOUTHERN CHILE...A WARM FRONT PASSES OVER THE SOUTHERN CONE
FAVORING MAXIMA OF 20-35MM. ON SATURDAY...A COLD FRONT ADVANCES
INTO CENTRAL CHILE AND ARGENTINA...AND ADDITIONALLY...LOW LEVEL
JETS INCREASE OVER THE SOUTHERNMOST SECTION. THESE JETS ARE ALSO
FAVORING MOISTURE CONVERGENCE ALONG THE WESTERN SECTOR OF SOUTH
AYSEN AND MAGALLANES...WITH PRECIPITABLE WATER LEVELS OF AROUND
25MM. THIS WILL FAVOR RAIN/SNOW MAXIMA OF 20-35MM IN THE
AFOREMENTIONED REGIONS. THE ATMOSPHERIC RIVER ASSOCIATED WITH THE
AMOUNTS OF PRECIPITABLE WATER IS EXPECTED TO CONTINUE INTO THE
SATURDAY AND SUNDAY...SUPPORTING THE INCREASED AVAILABLE MOISTURE
INTO THE SOUTHERN REGION OF CHILE. ADDITIONALLY...A ZONAL UPPER
LEVEL JET IS EXPECTED TO POSITION OVER THIS REGION OVER THE
WEEKEND...SUPPORTING MODERATE TO HEAVY PRECIPITATION IN MAGALLANES
AND AYSEN. MORE INFORMATION ABOUT THIS EVENT WILL BE PROVIDING IN
THE FOLLOWING FORECAST BULLETIN. NORTH ARGENTINA AND URUGUAY WILL
SEE MAXIMA OF 15MM AS THE STRENGTHENING FRONTAL SYSTEM ADVANCES
SOUTHWARD.

IN THE TROPICAL REGION OF SOUTH AMERICA...TROPICAL WAVES AND
TROUGHS CONTINUE TO PROGRESS OVER THE REGION. HOWEVER...MOST OF
THE HEAVIER PRECIPITATION IS EXPECTED TO REMAIN FURTHER NORTH OF
THE FORECAST REGION. ON THURSDAY...A TROPICAL WAVE OVER VENEZUELA
IS FORECAST MAXIMA OF 20-35MM. ON FRIDAY...THE WAVE WILL FAVOR
SIMILAR AMOUNTS IN SOUTHERN VENEZUELA...AND MAXIMA OF 15MM IN EAST
COLOMBIA INTO NORTH AMAZONAS-BRASIL. A SECOND TROPICAL WAVE OVER
THE GUIANAS WILL FAVOR MAXIMA OF 15-20MM. ON SATURDAY...A WAVE
MOVING INTO EASTERN VENEZUELA WILL FAVOR MAXIMA OF 20-40MM.

ACOSTA...(WPC)