467  
FXUS63 KOAX 222014  
AFDOAX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE  
314 PM CDT FRI JUN 22 2018  
   
SHORT TERM
 
(TONIGHT THROUGH MONDAY)  
ISSUED AT 315 PM CDT FRI JUN 22 2018  
 
GENERALLY DRY WEATHER THROUGH MOST OF THE EVENING AS WE WAIT FOR  
THE ARRIVAL OF THE NEXT SYSTEM MOVING OUT OF THE NORTHERN ROCKIES.  
CONVECTION SHOULD DEVELOP ACROSS THE WESTERN HIGH PLAINS TONIGHT,  
AND COULD BEGIN TO AFFECT EASTERN NEBRASKA BY MIDNIGHT AND BEYOND,  
ALTHOUGH THE STORMS DO LOSE QUITE A BIT OF THEIR PUNCH AS THEY GET  
THIS FAR EAST.  
 
THE WEAK UPPER WAVE CONTINUES TO MEANDER THROUGH THE MID MISSOURI  
RIVER VALLEY THROUGH THE DAY ON SATURDAY. THIS WILL RESULT IN A  
CHANCE OF MORNING SHOWERS AND STORMS, BUT MORE WIDESPREAD COVERAGE  
THROUGH THE AFTERNOON AND EVENING, ESPECIALLY WHEN COMBINED WITH  
DAYTIME HEATING. HOWEVER, OVERALL THE SEVERE THREAT REMAINS LOW  
AND RAINFALL AMOUNTS ARE NOT EXCESSIVE TOMORROW, BUT RAINFALL  
COULD DAMPER OUTDOOR ACTIVITIES ESPECIALLY ALONG/NORTH OF I80.  
 
THERE COULD BE A LINGERING STORM CHANCE SATURDAY EVENING. THERE IS  
ANOTHER WAVE MOVING OUT OF THE ROCKIES, WHICH BRINGS US A CHANCE  
OF RAIN ON SUNDAY MORNING. STRONGER AND MOSTLY LIKELY SEVERE  
STORMS APPEAR TO TAKE SHAPE ACROSS CENTRAL NE BY SUNDAY AFTERNOON,  
AND ROLL THROUGH THE AREA SUNDAY NIGHT. THESE STORMS DO THE HAVE  
THE POTENTIAL FOR LARGE HAIL AND WIND DAMAGE, ALONG WITH LOCALLY  
HEAVY RAIN, ESPECIALLY ALONG/SOUTH OF I80. PORTIONS OF EASTERN NE  
REMAIN IN A SLIGHT RISK FOR SEVERE STORMS DURING THIS TIME.  
 
ADDITIONAL RAIN POTENTIAL INTO MONDAY AS THE MAIN UPPER LOW SPINS  
INTO THE UPPER MIDWEST AND WE CONTINUE TO SEE LIFT .  
   
LONG TERM
 
(MONDAY NIGHT THROUGH FRIDAY)  
ISSUED AT 315 PM CDT FRI JUN 22 2018  
 
STILL SOME RAIN POTENTIAL ON TUESDAY, BUT BY THEN, THE BULK OF THE  
ENERGY IS SHIFT EAST INTO THE MISSISSIPPI RIVER VALLEY. WEDNESDAY  
IS LOOKING DRY AND HOT AGAIN AS TEMPS CLIMB BACK INTO THE 90S,  
WHICH COULD LINGER INTO THE END OF THE WEEK. SPOTTY RAIN CHANCES  
WEDNESDAY NIGHT NORTH OF I80. THURSDAY AND FRIDAY LOOK MOSTLY DRY  
BASED ON THE ECMWF, BUT GFS SUGGESTS SPOTTY PRECIP CHANCES  
CONTINUE.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)  
ISSUED AT 1222 PM CDT FRI JUN 22 2018  
 
HAVE ADDED PROB30 GROUPS AT ALL TERMINALS SATURDAY MORNING IN  
LIGHT OF POSSIBLE TSRA DEVELOPING OVER ERN NE. OTHERWISE VFR  
CONDITIONS EXPECTED.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 315 PM CDT FRI JUN 22 2018  
 
RIVER FLOOD WARNINGS CONTINUE ON THE MISSOURI RIVER DOWNSTREAM  
FROM PLATTSMOUTH. ELEVATED RIVER FLOWS JUST BELOW FLOOD STAGE ARE  
EXPECTED AT BOTH BLAIR AND OMAHA. THIS IS IN LARGE PART DUE TO  
THE UNCONTROLLED WATER COMING OUT OF EASTERN SD AND NORTHWEST IA  
FROM THE HEAVY RAINS A COUPLE OF NIGHTS AGO. TO HELP MITIGATE THE  
IMPACT OF THE FLOODING SLIGHTLY, THE CORPS OF ENGINEERS HAS  
LOWERED THE RELEASES OUT OF GAVINS POINT DAM TEMPORARILY TO 24,000  
CFS, DOWN FROM 35,000 CFS A FEW DAYS AGO. THESE LOWER RELEASES  
WON'T ELIMINATE THE FLOODING THOUGH. THE CURRENT RIVER FORECASTS  
ON OUR AHPS WEBPAGE FACTOR IN 24 HOURS OF FORECAST RAINFALL, WHICH  
IS EXPECTED TO REMAIN ON THE LIGHT SIDE. WHAT IS NOT FACTORED IN  
THIS THE POTENTIAL FOR HEAVY RAINS IN THE MISSOURI RIVER BASIN  
SUNDAY THROUGH TUESDAY, WHICH COULD RANGE AN ADDITIONAL 2 TO 4  
INCHES IN SOME LOCATIONS. THE BOTTOM LINE, EXPECT ELEVATED RIVER  
LEVELS AND POSSIBLE FLOODING SOUTH OF OMAHA ON THE MISSOURI RIVER  
FOR AT LEAST THE NEXT WEEK.  
 
LONG RANGE FORECASTS FROM THE CORPS SUGGEST THAT GAVINS POINT  
RELEASES COULD INCREASE TO 50,000 CFS BY THE END OF THE MONTH TO  
ACCOMMODATE WATER UPSTREAM INTO SOUTH DAKOTA AND NORTH DAKOTA.  
WHILE THIS IS WELL OUTSIDE OF OUR FORECAST WINDOW, IT IS UNCLEAR  
HOW THESE INCREASED FLOWS WILL IMPACT THE RIVER, WHICH WILL BE  
HIGHLY DEPENDENT ON SUMMER RAINFALL.  
 

 
   
OAX WATCHES/WARNINGS/ADVISORIES
 
 
NE...NONE.  
IA...NONE.  

 
 

 
 
SHORT TERM...DEWALD  
LONG TERM...DEWALD  
AVIATION...DEE  
HYDROLOGY...DEWALD  
 
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