977  
FXUS01 KWBC 200719  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
318 AM EDT SUN APR 20 2025  
 
VALID 12Z SUN APR 20 2025 - 12Z TUE APR 22 2025  
 
...LIGHT TO MODERATE SNOW OVER PARTS OF THE CASCADES, NORTHERN  
INTERMOUNTAIN REGION, NORTHERN ROCKIES, AND UPPER GREAT LAKES ON  
SUNDAY AND MONDAY...  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PARTS OF THE  
MIDDLE MISSISSIPPI VALLEY AND THE SOUTHERN PLAINS ON SUNDAY...  
 
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF  
THE MIDDLE/LOWER MISSISSIPPI VALLEY ON SUNDAY...  
 
A WAVE OF LOW PRESSURE OVER THE SOUTHERN PLAINS ON SUNDAY WILL  
MOVE NORTHEASTWARD TO INTO WESTERN QUEBEC, CANADA, BY TUESDAY. THE  
ASSOCIATED FRONT WILL MOVE FROM THE SOUTHERN PLAINS TO THE  
NORTHEAST TO THE MID-ATLANTIC AND THEN SOUTHWESTWARD TO THE  
SOUTHERN PLAINS BY TUESDAY AS WELL. MOISTURE FROM THE GULF OF  
AMERICA WILL STREAM NORTHWARD OVER THE PLAINS AND INTERSECT WITH  
THE BOUNDARY, PRODUCING SHOWERS AND SEVERE THUNDERSTORMS OVER THE  
MIDDLE/LOWER MISSISSIPPI VALLEY. THEREFORE, THE SPC HAS ISSUED AN  
ENHANCED RISK (LEVEL 3/5) OF SEVERE THUNDERSTORMS OVER THE  
MIDDLE/LOWER MISSISSIPPI VALLEY THROUGH MONDAY MORNING. THE  
HAZARDS ASSOCIATED WITH THESE THUNDERSTORMS ARE FREQUENT  
LIGHTNING, SEVERE THUNDERSTORM WIND GUSTS, HAIL, AND A FEW  
TORNADOES. FURTHERMORE, THERE IS AN ADDED THREAT OF EF 2 TO EF 5  
TORNADOS OVER THE MIDDLE/LOWER MISSISSIPPI VALLEY.  
 
IN ADDITION, THE SHOWERS AND THUNDERSTORMS WILL PRODUCE HEAVY RAIN  
OVER PARTS OF THE MIDDLE/LOWER MISSISSIPPI VALLEY AND THE SOUTHERN  
PLAINS ON SUNDAY. THEREFORE, THE WPC HAS ISSUED A SLIGHT RISK  
(LEVEL 2/4) OF EXCESSIVE RAINFALL OVER PARTS OF THE MIDDLE/LOWER  
MISSISSIPPI VALLEY AND THE SOUTHERN PLAINS THROUGH MONDAY MORNING.  
THE ASSOCIATED HEAVY RAIN WILL CREATE MAINLY LOCALIZED AREAS OF  
FLASH FLOODING, WITH URBAN AREAS, ROADS, SMALL STREAMS, AND  
LOW-LYING AREAS THE MOST VULNERABLE.  
 
ON MONDAY, THE THREAT OF SEVERE THUNDERSTORMS AND EXCESSIVE  
RAINFALL REDUCES. HOWEVER, SHOWERS AND THUNDERSTORMS WILL CONTINUE  
ALONG AND AHEAD OF THE FRONT FROM THE GREAT LAKES/OHIO VALLEY INTO  
THE TENNESSEE VALLEY, LOWER MISSISSIPPI VALLEY, AND THE WESTERN  
GULF COAST. THE THREAT OF EXCESSIVE RAINFALL ASSOCIATED WITH THESE  
STORMS IS NOT EXPECTED.  
 
EARLY MONDAY MORNING, WET SNOW WILL DEVELOP NEAR THE WESTERN THIRD  
OF LAKE SUPERIOR. BY MONDAY EVENING, THE SWATH OF WET SNOW WILL  
MOVE EASTWARD OVER PARTS OF THE UPPER PENINSULAS OF MICHIGAN,  
MOVING INTO CANADA BY TUESDAY MORNING. RAIN WITH EMBEDDED  
THUNDERSTORMS WILL MOVE INTO THE NORTHEAST OVERNIGHT MONDAY.  
SHOWERS AND THUNDERSTORMS WILL CONTINUE ALONG THE FRONT OVERNIGHT  
MONDAY INTO TUESDAY MORNING FROM PARTS OF THE EASTERN  
OHIO/TENNESSEE VALLEYS INTO THE LOWER MISSISSIPPI VALLEY AND  
CENTRAL GULF COAST.  
 
MEANWHILE, ON SUNDAY, UPPER-LEVEL ENERGY WILL MOVE ONSHORE OVER  
THE PACIFIC NORTHWEST OVERNIGHT, DEVELOPING A FRONT OVER THE  
NORTHERN INTERMOUNTAIN REGION. THE ENERGY WILL PRODUCE RAIN AND  
HIGHEST-ELEVATION SNOW OVER PARTS OF THE NORTHWEST INTO THE  
NORTHERN INTERMOUNTAIN REGION AND THE NORTHERN ROCKIES.  
 
ON MONDAY, THE FRONT CONSOLIDATES OVER THE NORTHERN  
ROCKIES/NORTHERN INTERMOUNTAIN REGION AND MOVES EASTWARD TO THE  
NORTHERN/CENTRAL PLAINS ACROSS THE CENTRAL ROCKIES INTO THE GREAT  
BASIN BY TUESDAY. THE SYSTEM WILL CREATE HIGHEST-ELEVATION SNOW  
AND LOWER-ELEVATION RAIN OVER PARTS OF THE NORTHERN INTERMOUNTAIN  
REGION/NORTHERN ROCKIES. RAIN WILL BEGIN TO DEVELOP OVER PARTS OF  
THE NORTHERN HIGH PLAINS ON MONDAY AFTERNOON INTO EVENING. THE  
RAIN WILL MOVE INTO PARTS OF THE NORTHERN PLAINS/UPPER MISSISSIPPI  
VALLEY BY TUESDAY MORNING.  
 
ZIEGENFELDER  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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