774  
FOUS30 KWBC 200718  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
318 AM EDT FRI MAR 20 2026  
 
DAY 1  
VALID 12Z FRI MAR 20 2026 - 12Z SAT MAR 21 2026  
 
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
WESTERN WASHINGTON STATE...  
 
AT THE BEGINNING OF THE FORECAST PERIOD, A STUBBORN ATMOSPHERIC  
RIVER IS FORECAST TO WEAKEN AS A SURFACE LOW AND ATTENDANT COLD  
FRONT PROGRESS EASTWARD INTO THE PACIFIC NORTHWEST. EVEN SO,  
MODERATE IVT VALUES ON THE ORDER OF 500-700 KG/M * S DIRECTED INTO  
THE WA COASTLINE FROM 12-18Z SHOULD MAINTAIN THE THREAT OF LOCALLY  
HEAVY RAINFALL AHEAD OF THE FRONT. WHILE HOURLY RAINFALL RATES WILL  
LIKELY REMAIN BELOW 0.5 INCHES PER HOUR, ISOLATED INSTANCES OF  
EXCESSIVE RAINFALL REMAIN POSSIBLE IN UPSLOPE REGIONS OF THE  
OLYMPICS AND CASCADES OWING TO ANTECEDENT RAINFALL OVER THE LAST  
FEW DAYS.  
 
ASHERMAN  
 
DAY 2  
VALID 12Z SAT MAR 21 2026 - 12Z SUN MAR 22 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
ASHERMAN  
 
DAY 3  
VALID 12Z SUN MAR 22 2026 - 12Z MON MAR 23 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
ASHERMAN  
 
DAY 1 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/94EPOINTS.TXT  
DAY 2 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/98EPOINTS.TXT  
DAY 3 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/99EPOINTS.TXT  
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