680  
FXUS02 KWBC 051803  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
203 PM EDT SAT APR 5 2025  
 
VALID 12Z TUE APR 08 2025 - 12Z SAT APR 12 2025  
 
   
..GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
THE WPC MEDIUM RANGE GUIDANCE SUITE WAS PRIMARILY DERIVED FROM A  
COMPOSITE BLEND OF SEEMINGLY REASONABLE AND BEST CLUSTERED  
GUIDANCE FROM THE 00 UTC ECMWF/UKMET/CANADIAN MODELS AND  
ECMWF/CANADIAN ENSEMBLE MEANS. FORECAST SPREAD INCREASES NORMALLY  
THROUGH MEDIUM-RANGE TIME SCALES AND A COMPOSITE OF THESE OVERALL  
COMPATIBLE GUIDANCE PIECES TENDS TO MITIGATE MUCH OF NUMEROUS  
SMALLER SCALE SYSTEM DETAILS AS CONSISTENT WITH INDIVIDUAL SYSTEM  
PREDICTABILITY. THIS PLAN MAINTAINS GOOD WPC PRODUCT CONTINUITY,  
GENERALLY IN LINE WITH MACHINE LEARNING GUIDANCE AND THE NATIONAL  
BLEND OF MODELS. LATEST 12 UTC GUIDANCE OVERALL IS IN LINE SO FAR.  
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
HEAVY RAINFALL POTENTIAL DECREASES QUITE A BIT GOING INTO THE  
TUESDAY AND WEDNESDAY TIME PERIOD, WITH NO RISK AREAS NECESSARY FOR  
BOTH THE DAY 4 AND DAY 5 EXCESSIVE RAINFALL OUTLOOKS. WITH THE  
EXCEPTION OF SOME LOCALLY HEAVY SHOWERS ACROSS PORTIONS OF THE  
CENTRAL AND SOUTHERN FLORIDA PENINSULA, THE THREAT OF HEAVY  
RAINFALL SHOULD END BY TUESDAY ACROSS THE REST OF THE COUNTRY.  
HOWEVER, LINGERING SNOW IS LIKELY ACROSS PORTIONS OF NORTHERN NEW  
ENGLAND THROUGH TUESDAY EVENING MAIN SURFACE LOW DEPARTURE.  
 
ELSEWHERE ACROSS THE COUNTRY, ORGANZIED RAIN AND MOUNTAIN SNOW  
PERIODS RETURN TO ESPECIALLY WESTERN WASHINGTON AND OREGON  
COURTESY OF ONSHORE FLOW AND AN POTENTIALLY AMPLIFIED SERIES OF  
SHORTWAVE TROUGH PASSAGES ALL NEXT WEEK, BUT THESE DON'T LOOK LIKE  
MAJOR EVENTS AT THIS TIME. WITH DOWNSTREAM PROPAGATION OF THESE  
TROUGHS, LIGHT PRECIPITATION CHANCES CROSS THE NORTHWEST THEN  
NORTHERN PLAINS AND MIDWEST INTO MID-LATE NEXT WEEK, BUT THERE IS  
SOME RISK FOR MODERATE AMOUNTS WITH RUNOFF ISSUES OVER THE OHIO  
VALLEY GIVEN INUDATED SOILS FROM CURRENTLY ONGOING RAINS. THE NEXT  
GOOD CHANCE OF ENHANCED RAINFALL SETTLES OVER THE EAST FRIDAY AND  
NEXT SATURDAY WITH POTENTIAL SURFACE LOW/COASTAL LOW DEVELOPMENT.  
 
IN TERMS OF TEMPERATURES, MUCH COOLER CONDITIONS ARE COMING FOR THE  
EASTERN U.S. AFTER THE STRONG COLD FRONT EXITS THE EAST COAST  
BY MONDAY MORNING. AFTERNOON HIGHS ARE LIKELY TO BE ON THE ORDER  
OF 10 TO 20 DEGREES BELOW EARLY APRIL AVERAGES ON TUESDAY AND  
WEDNESDAY FROM THE OHIO VALLEY/GREAT LAKES TO THE NORTHEAST U.S.,  
COMPLIMENTS OF THE UPPER LOW OVERHEAD. READINGS RETURN CLOSER TO  
AVERAGE BY LATE IN THE WEEK FOR THE EAST COAST STATES WITH THE  
UPPER TROUGH LIFTING OUT OF THE REGION. MEANWHILE, A WARM PATTERN  
IS EXPECTED FOR THE WESTERN U.S. THROUGH THE WEEK WITH BOTH DAYTIME  
HIGHS AND OVERNIGHT LOWS ABOUT 10-20 DEGREES ABOVE AVERAGE, WITH  
THE GREATEST ANOMALIES OVER THE GREAT BASIN.  
 
HAMRICK/SCHICHTEL  
 
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC  
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL  
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT  
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:  
 
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW  
 

 
 
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