845  
FXUS02 KWBC 091917  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
315 PM EDT THU JUN 09 2022  
 
VALID 12Z SUN JUN 12 2022 - 12Z THU JUN 16 2022  
 
...DANGEROUS/RECORD HEAT FOR THE SOUTHWEST/GREAT BASIN TO TEXAS  
INTO THE WEEKEND TO SHIFT INTO THE EAST-CENTRAL AND SOUTHEAST U.S.  
NEXT WEEK...  
...HEAVY RAIN/RUNOFF THREAT FROM THE NORTHERN GREAT BASIN/ROCKIES  
THROUGH NORTH DAKOTA SUNDAY/MONDAY...  
 
19Z UPDATE: THE 12Z MODEL GUIDANCE SUITE IS IN VERY GOOD SYNOPTIC  
SCALE AGREEMENT THROUGH THE MAJORITY OF THE FORECAST PERIOD,  
ESPECIALLY WITH THE BUILDING UPPER RIDGE AXIS ACROSS THE MIDWEST  
AND OHIO VALLEY REGION. SOME MINOR DIFFERENCES BECOME APPARENT  
WITH THE CMC BY EARLY NEXT WEEK WITH A MORE AMPLIFIED SOLUTION  
ACROSS THE EAST COAST REGION. BY NEXT WEDNESDAY, THE GFS IS  
FASTER TO LIFT THE MAIN SHORTWAVE TROUGH OUT OF THE NORTHERN  
PLAINS COMPARED TO THE SLOWER ECMWF/CMC SOLUTIONS. BY THURSDAY,  
THE GFS/GEFS IS DISPLACED SLIGHTLY EAST WITH THE RIDGE AXIS ACROSS  
THE NORTHEAST U.S. AND SLIGHTLY FASTER WITH THE ARRIVAL OF THE  
NEXT PACIFIC STORM SYSTEM. OVERALL, NOT MANY CHANGES WERE  
NECESSARY COMPARED TO THE EARLIER FORECAST ISSUANCE. THE PREVIOUS  
FORECAST DISCUSSION IS APPENDED BELOW FOR REFERENCE. /HAMRICK  
----------------  
   
..PATTERN OVERVIEW AND SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
THE UPPER PATTERN OVER THE NATION WILL AMPLIFY INTO SUNDAY WITH  
TROUGH DEVELOPMENT ACROSS THE WEST COAST AND OVER THE NORTHEAST TO  
SANDWICH RIDGING/HIGH HEAT SPREAD FROM THE SOUTHWEST TO THE  
SOUTH-CENTRAL U.S.. ACTIVE LEAD LOW PRESSURE SYSTEMS AND HEAVY  
RAINFALL WILL MOSTLY SHIFT OFFSHORE THE EAST COAST BY SUNDAY, BUT  
A WAVY TRAILING FRONT WILL SETTLE DOWN ACROSS THE SOUTH. AMPLIFIED  
TROUGHING WILL WORK INLAND OVER AN UNSETTLED/COOLING WEST  
EARLY-MID NEXT WEEK AS RIDGING STRONGLY BUILDS THROUGH THE  
EAST-CENTRAL U.S. AND THE SOUTHEAST. AN EXCESSIVE HEAT THREAT  
UNDER THE RIDGE WILL CHALLENGE DAILY RECORDS. THE STORM PREDICTION  
CENTER ALSO HAS A RISK FOR WILDFIRES OVER PARTS OF THE SOUTHWEST  
SUNDAY/MONDAY IN THIS PATTERN. MEANWHILE, UNSETTLED/WET WEATHER  
WILL SPREAD FROM THE PACIFIC NORTHWEST TO THE NORTHERN ROCKIES  
WHERE SOME HIGH ELEVATION SNOWS ARE POSSIBLE. THERE IS ALSO  
POTENTIAL FOR HEAVY RAIN WITH SOME LOCAL RUNOFF CONCERNS FOR THE  
NORTHERN GREAT BASIN/ROCKIES THIS WEEKEND AS DEEPER MOISTURE FROM  
THE PACIFIC ADVECTS INLAND. FLOW DOWNSTREAM OVER NORTHERN  
PLAINS/UPPER MIDWEST NEXT WEEK WILL FAVOR PERIODIC STRONG MCS  
ACTIVITY WITH HEAVY DOWNPOURS AS A SERIES OF UNCERTAIN IMPULSES  
TRACK ON THE NORTHERN PERIPHERY OF THE UPPER RIDGE. AN  
EXPERIMENTAL WEATHER PREDICTION CENTER MEDIUM RANGE EXCESSIVE  
RAINFALL OUTLOOK HAS A "SLIGHT" RISK AREA FOR NORTH DAKOTA BY  
MONDAY CONSIDERING SIMILAR MULTI-MODEL FLOW/QPF FOCUS WHERE  
ANTECEDENT CONDITIONS SEEM MOST CONDUCIVE FOR RUNOFF ISSUES AS PER  
THE RFCS/NATIONAL WATER CENTER.  
 
   
..GUIDANCE AND PREDICTABILITY EVALUATION
 
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM A  
COMPOSITE BLEND OF REASONABLY CLUSTERED GUIDANCE OF THE 18 UTC GFS  
AND 12 UTC ECMWF/UKMET/CANADIAN ALONG WITH THE 01 UTC NATIONAL  
BLEND OF MODELS (NBM) FOR DAYS 3-5 (SUNDAY-TUESDAY) BEFORE LEANING  
ON THE GEFS/ECMWF ENSEMBLE MEANS AND BEST MATCHED MODEL GUIDANCE  
FROM THE ECMWF/CANADIAN INTO DAYS 6/7 (NEXT THURSDAY/FRIDAY).  
WHILE COMPLEX CONVECTIVE DETAILS WILL REMAIN UNCERTAIN INTO SHORT  
RANGE TIME SCALES, NEWER 00 UTC GUIDANCE REMAINS IN LINE WITH THE  
OVERALL FORECAST SCENARIO IN A PATTERN WITH AVERAGE OR BETTER  
OVERALL FORECAST PREDICTABILITY AND CONTINUITY THROUGH THESE  
MEDIUM RANGE TIME SCALES AS MAIN SYSTEM AMPLITUDES AND TIMINGS  
HAVE TRENDED MORE IN SYNC.  
 
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  
 
HAZARDS:  
- HEAVY RAIN ACROSS PORTIONS OF THE NORTHERN ROCKIES AND THE  
NORTHERN GREAT BASIN, SUN-MON, JUN  
12-JUN 13.  
- HEAVY RAIN ACROSS PORTIONS OF THE UPPER MISSISSIPPI VALLEY AND  
THE NORTHERN PLAINS, MON, JUN 13.  
- FLOODING POSSIBLE ACROSS PORTIONS OF THE SOUTHERN PLAINS, THE  
NORTHERN ROCKIES, AND THE NORTHERN  
GREAT BASIN.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE MIDDLE  
MISSISSIPPI VALLEY, THE SOUTHERN  
PLAINS, THE UPPER MISSISSIPPI VALLEY, AND THE NORTHERN PLAINS.  
- FLOODING LIKELY ACROSS PORTIONS OF THE PACIFIC NORTHWEST, THE  
NORTHERN ROCKIES, THE NORTHERN  
GREAT BASIN, AND THE NORTHERN PLAINS.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE SOUTHERN ROCKIES/PLAINS,  
THE CENTRAL GREAT BASIN, THE  
SOUTHWEST, AND CALIFORNIA, SUN, JUN 12.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE CENTRAL/SOUTHERN PLAINS,  
THE LOWER/MIDDLE MISSISSIPPI  
VALLEY, THE SOUTHERN ROCKIES, AND THE SOUTHWEST, SUN-MON, JUN  
12-JUN 13.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE LOWER/MIDDLE MISSISSIPPI  
VALLEY, THE TENNESSEE/OHIO VALLEY,  
THE MID-ATLANTIC, THE SOUTHERN APPALACHIANS, THE SOUTHEAST, AND  
THE SOUTHERN PLAINS, MON-THU, JUN  
13-JUN 16.  
- EXCESSIVE HEAT ACROSS PORTIONS OF THE MIDDLE/LOWER MISSISSIPPI  
VALLEY, THE GREAT LAKES, AND THE  
OHIO/TENNESSEE VALLEY, MON-WED, JUN 13-JUN 15.  
- HIGH WINDS ACROSS PORTIONS OF THE CENTRAL/NORTHERN GREAT BASIN,  
THE NORTHERN/CENTRAL ROCKIES,  
CALIFORNIA, AND THE SOUTHWEST, SUN, JUN 12.  
- HIGH WINDS ACROSS PORTIONS OF THE SOUTHERN/CENTRAL ROCKIES, THE  
CENTRAL GREAT BASIN, AND THE  
SOUTHWEST, MON, JUN 13.  
- HIGH WINDS ACROSS PORTIONS OF THE NORTHERN PLAINS, WED, JUN 15.  
- ENHANCED WILDFIRE RISK ACROSS PORTIONS OF THE CENTRAL GREAT  
BASIN AND THE SOUTHWEST, SUN, JUN 12.  
- ENHANCED WILDFIRE RISK ACROSS PORTIONS OF THE SOUTHERN  
ROCKIES/PLAINS, AND THE SOUTHWEST, MON,  
JUN 13.  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION, EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK, WINTER WEATHER OUTLOOK PROBABILITIES AND HEAT INDICES ARE  
AT:  
 
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  
 

 
 

 
 
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