905  
FXUS01 KWBC 152000  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
359 PM EDT WED AUG 15 2018  
 
VALID 00Z THU AUG 16 2018 - 00Z SAT AUG 18 2018  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF  
NEBRASKA AND SOUTH DAKOTA.  
 
...HEAVY RAIN POSSIBLE FOR PARTS OF THE WESTERN OHIO VALLEY INTO  
PARTS OF THE LOWER MISSISSIPPI VALLEY...  
   
..HEAVY RAIN POSSIBLE FOR PARTS OF THE NORTHERN PLAINS
 
 
AN DEEP UPPER LEVEL WAVE IS CURRENTLY MOVING ACROSS THE NORTHERN  
PLAINS, RESULTING IN COMPLEX OF SHOWERS AND THUNDERSTORMS ACROSS  
SOUTH DAKOTA AND NORTHERN NEBRASKA. AS THIS AREA OF HEAVY RAIN AND  
STRONG THUNDERSTORMS IS EXPECTED TO CONTINUE, THE STORM PREDICTION  
CENTER HAS ISSUED A SLIGHT RISK FOR SEVERE THUNDERSTORMS THROUGH  
TONIGHT. THE WEATHER PREDICTION CENTER HAS ALSO OUTLINED THIS AREA  
AS HAVING A MARGINAL TO SLIGHT RISK FOR EXCESSIVE RAINFALL AND  
FLASH FLOODING. THIS UPPER LEVEL WAVE WILL CONTINUE TO SHIFT  
SOUTHEAST, PUTTING SOUTHEAST NEBRASKA, MUCH OF EASTERN KANSAS, AND  
FAR NORTHWEST MISSOURI IN A SLIGHT RISK FOR SEVERE STORMS ON  
THURSDAY.  
 
A FRONTAL SYSTEM IS CURRENTLY STRETCHING FROM THE SOUTHERN PLAINS  
NORTHEAST TOWARDS THE GREAT LAKES AND ACROSS THE NORTHEAST. WARM,  
MOIST AIR IS BEING PUMPED NORTHWARD FROM THE GULF OF MEXICO  
TOWARDS THIS FRONTAL BOUNDARY, ESPECIALLY ACROSS THE SOUTHERN  
PLAINS AND LOW/MIDDLE MISSISSIPPI VALLEY. THIS IS RESULTING IN AN  
UNSTABLE ATMOSPHERE CAPABLE OF PRODUCING STRONG STORMS AND  
EXCESSIVE RAINFALL. THE WEATHER PREDICTION CENTER HAVE OUTLINED  
TWO AREAS AS BEING IN A SLIGHT RISK FOR EXCESSIVE RAINFALL AND  
FLASH FLOODING THROUGH TONIGHT. THE FIRST ENCOMPASSES THE  
NORTHWEST PORTION OF THE SOUTHERN PLAINS (INCLUDING THE OKLAHOMA  
AND TEXAS PANHANDLES), AND THE SECOND STRETCHES FROM FAR EASTERN  
OKLAHOMA INTO SOUTHERN INDIANA AND ALONG THE OHIO RIVER OF  
KENTUCKY. FURTHERMORE, A PORTION OF WEST-CENTRAL ARKANSAS AND FAR  
EAST-CENTRAL OKLAHOMA IS IN A MODERATE RISK FOR FLASH FLOODING.  
FLASH FLOOD WATCHES AND WARNINGS ARE ONGOING ACROSS THIS MODERATE  
RISK REGION, STRETCHING NORTHWARD INTO THE SOUTHERN MISSOURI. THE  
STORM PREDICTION CENTER HAS ALSO PLACED THESE SAME REGIONS IN A  
MODERATE RISK OF SEVERE WEATHER DEVELOPMENT. AS THE FRONTAL  
BOUNDARY SLOWLY SHIFTS EASTWARD OVER THE COMING DAYS, SO TOO WITH  
THE RISK FOR EXCESSIVE RAINFALL AND STRONG STORMS.  
 
MEANWHILE THE WESTERN U.S. IS STILL BEING IMPACTED BY FIRE WEATHER  
CONCERNS. MONSOONAL MOISTURE IS CURRENTLY MAKING ITS WAY INTO THE  
SOUTHWEST. HOWEVER, AS THIS MOISTURE SURGES NORTHWARD ACROSS THE  
WESTERN U.S., A VERY DRY NEAR-SURFACE LAYER WILL LIKELY PREVENT  
ANY RAINFALL FROM HITTING THE GROUND. FURTHERMORE IT WILL LIKELY  
RESULT IN DRY THUNDERSTORMS, WITH LIGHTNING POTENTIALLY SPARKING  
NEW WILDFIRES. RED FLAG WARNINGS ARE IN EFFECT ACROSS CENTRAL  
OREGON, NORTHEAST CALIFORNIA, WESTERN NEVADA, AND SOUTHWEST  
WYOMING THROUGH THIS EVENING. AIR QUALITY ALERTS ARE ALSO  
ENCOMPASSING LARGE PORTIONS OF THE WESTERN U.S. AS ONGOING  
WILDFIRES CONTINUE TO INFUSE THE AIR WITH COPIOUS AMOUNTS OF  
SMOKE. MUCH OF WASHINGTON, OREGON, NORTHERN IDAHO, AND WESTERN  
MONTANA, AS WELL AS A PORTION OF CENTRAL CALIFORNIA ARE INCLUDED  
IN AN AIR QUALITY ALERT. AN AIR QUALITY ALERT FOR BLOWING DUST HAS  
ALSO BEEN ISSUED NEAR AND AROUND PHOENIX, ARIZONA THROUGH THURSDAY.  
 
WIX  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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