273  
FXUS02 KWBC 101851  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
250 PM EDT FRI JUN 10 2022  
 
VALID 12Z MON JUN 13 2022 - 12Z FRI JUN 17 2022  
 
...DANGEROUS/RECORD HEAT TO SHIFT FROM THE PLAINS INTO THE  
EAST-CENTRAL AND SOUTHEAST U.S. NEXT WEEK...  
...HEAVY RAIN/RUNOFF THREAT OVER PARTS OF THE NORTHERN  
ROCKIES/PLAINS EARLY NEXT WEEK...  
 
18Z UPDATE: THE 12Z MODEL GUIDANCE SUITE HAS A VERY GOOD OVERALL  
DEPICTION ON THE SYNOPTIC SCALE THROUGH THE MIDDLE OF NEXT WEEK,  
ESPECIALLY WITH THE BUILDING UPPER RIDGE AXIS ACROSS THE MIDWEST  
AND OHIO VALLEY REGION. THE UKMET IS SLIGHTLY MORE ROBUST WITH  
THE RIDGE, BUT STILL CLOSE ENOUGH TO THE CONSENSUS TO MERIT THE  
USE OF A MULTI-DETERMINISTIC BLEND THROUGH WEDNESDAY. THE 6Z GFS  
WAS AN OUTLIER SOLUTION WITH RESPECT TO A SURFACE LOW DEVELOPING  
NEAR THE SOUTHEAST U.S. COAST THAT RETROGRADED WESTWARD, WHEREAS  
THE 00Z AND 12Z RUNS WERE MUCH CLOSER TO THE CONSENSUS ACROSS THIS  
REGION. THUS, THE 00Z GFS WAS SUBSTITUTED FOR THE 6Z RUN FOR THE  
FRONTS/PRESSURES PROGS. THE 12Z CMC STRAYS FROM THE CONSENSUS BY  
FRIDAY ACROSS THE GREAT LAKES WITH MUCH LESS TROUGHING INDICATED  
AND A LESS AMPLIFIED RIDGE ACROSS THE WESTERN HIGH PLAINS. BY THE  
END OF THE WEEK, SOME OF THE GEFS AND ECENS WERE USED WHILE STILL  
INCLUDING SOME OF THE 00Z CMC/ECMWF/GFS/PREVIOUS WPC CONTINUITY.  
OVERALL, NOT MANY CHANGES WERE NECESSARY COMPARED TO THE EARLIER  
FORECAST ISSUANCE. THE PREVIOUS FORECAST DISCUSSION IS APPENDED  
BELOW FOR REFERENCE. /HAMRICK  
--------------------  
   
..OVERVIEW AND GUIDANCE/PREDICTABILITY EVALUATION
 
 
THE MEDIUM RANGE PERIOD WILL LIKELY FEATURE A TRANSITION BETWEEN  
AMPLIFIED REGIMES. THE FIRST PART OF THE WEEK WILL SEE A RATHER  
AMPLIFIED UPPER TROUGH CROSSING THE WEST AND A STRONG RIDGE  
COVERING THE SOUTHEAST/EAST-CENTRAL U.S. WHILE A TROUGH CROSSES  
THE NORTHEAST AND BEGINS TO AMPLIFY INTO THE ATLANTIC. CONTINUED  
PROGRESSION OF THE EJECTING WESTERN ENERGY ACROSS THE NORTHERN  
U.S./SOUTHERN CANADA AND THE APPROACH OF ANOTHER AMPLIFIED UPPER  
TROUGH TOWARD THE WEST COAST SHOULD PROMOTE UPPER RIDGING OVER THE  
PLAINS LATE IN THE WEEK. THIS EVOLUTION SHOULD PROMOTE ACTIVE  
WEATHER OVER PARTS OF THE NORTHERN TIER INTO THE EAST, HOT WEATHER  
FROM THE CENTRAL/SOUTHERN PLAINS INTO THE EAST-CENTRAL  
U.S./SOUTHEAST WITH THE BEST POTENTIAL FOR RECORD HIGHS DURING  
MONDAY-WEDNESDAY, AND PRONOUNCED TEMPERATURE SWINGS (CHILLY EARLY  
AND WARM TO HOT LATE) OVER PARTS OF THE WEST/HIGH PLAINS.  
 
LATEST MODELS AND ENSEMBLES ARE FAIRLY AGREEABLE IN THEIR  
DEPICTION OF THE LARGE SCALE PATTERN EVOLUTION BUT DIFFER WITH  
SOME EMBEDDED DETAILS. TOWARD MIDWEEK THE UKMET HAS TENDED TO BE  
ON THE SLOW SIDE WITH THE UPPER LOW ANCHORING THE WESTERN  
U.S./SOUTHERN CANADA SYSTEM, BUT THIS LOOKS LESS EXTREME IN LIGHT  
OF THE NEW 00Z ECMWF TREND. EVEN VERSUS THE NEW RUN, THE 00Z  
ECMWF STRAYED TO THE SLOW SIDE ON DAY 7 FRIDAY. OTHER GUIDANCE  
DEVELOPS TYPICAL SPREAD FOR THE OVERALL TROUGH THAT REACHES THE  
GREAT LAKES AND EAST-CENTRAL CANADA LATE NEXT WEEK. IN GENERAL  
CLUSTERING FOR THE TROUGH NEARING THE WEST COAST AFTER MIDWEEK HAS  
BEEN BETTER THAN AVERAGE THUS FAR. THE NEW 00Z GFS BECOMES  
SOMEWHAT SOUTHWEST OF CONSENSUS FOR THE EMBEDDED UPPER LOW THOUGH.  
MEANWHILE THE GUIDANCE DEVELOPS SOME SPREAD FOR EXACT DETAILS OF  
FLOW ALOFT ALONG AND OFFSHORE THE EAST COAST, ULTIMATELY AFFECTING  
THE POSITION OF A POTENTIAL BACKDOOR FRONT OVER THE  
MID-ATLANTIC/CAROLINAS. AN EARLY-PERIOD BLEND AMONG THE 12Z/18Z  
OPERATIONAL MODELS FOLLOWED BY PARTIAL INCORPORATION OF THE 18Z  
GEFS/12Z ECMWF MEANS REFLECTED THE DESIRED CONSENSUS/INTERMEDIATE  
SOLUTION FOR SIGNIFICANT FEATURES AND YIELDED REASONABLE  
CONTINUITY.  
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
A VIGOROUS AND WAVY FRONTAL SYSTEM REACHING THE NORTHERN PLAINS  
EARLY NEXT WEEK SHOULD PROVIDE A FOCUS FOR LOCALLY HEAVY RAINFALL  
OVER SOME AREAS. CURRENTLY THE BEST COMBINATION OF INSTABILITY  
AND ANOMALOUSLY HIGH MOISTURE ALONG WITH ANTECEDENT CONDITIONS  
SUPPORT MAINTAINING A SLIGHT RISK AREA OVER PARTS OF NORTH DAKOTA  
IN THE WEATHER PREDICTION CENTER EXPERIMENTAL DAY 4 (MONDAY-MONDAY  
NIGHT) EXCESSIVE RAINFALL OUTLOOK. ADDITIONAL AREAS OF ENHANCED  
RAINFALL MAY BE POSSIBLE AS THE FRONT MOVES FROM THE PLAINS INTO  
THE EAST BUT IT WILL TAKE ADDITIONAL TIME TO REFINE THE DETAILS.  
A LEADING FRONT EXTENDING INTO THE EAST AND IMPULSES RIDING AROUND  
THE UPPER RIDGE MAY ALSO HELP TO PRODUCE ONE OR MORE CONVECTIVE  
SYSTEMS TRACKING SOUTHEAST FROM THE UPPER MIDWEST AND VICINITY.  
IT WILL LIKELY TAKE WILL INTO THE SHORT RANGE PERIOD TO CLARIFY  
THAT ASPECT OF THE FORECAST. WITHIN THE AREA OF HEAT  
TRANSITIONING FROM THE PLAINS INTO EAST-CENTRAL U.S./SOUTHEAST  
EARLY-MID WEEK, EXPECT HIGHS UP TO 10-20F ABOVE NORMAL WITH SOME  
CENTRAL PLAINS LOCATIONS POSSIBLY REACHING PLUS 20-25F ANOMALIES  
ON MONDAY. NUMEROUS DAILY RECORDS FOR HIGHS/WARM LOWS WILL BE  
POSSIBLE DURING MONDAY-WEDNESDAY. EVEN WITH TEMPERATURES  
MODERATING FROM WEST TO EAST, THE SOUTHERN TIER WILL REMAIN ON THE  
HOT SIDE WITH PLUS 5-10F ANOMALIES PERSISTING INTO FRIDAY. THE  
UPPER TROUGH CROSSING THE WEST EARLY IN THE WEEK WILL BRING A  
BRIEF PERIOD OF HIGHS 10-20F BELOW NORMAL ACROSS THE NORTHERN HALF  
OF THE REGION. THE UPPER RIDGE THAT BUILDS IN BEHIND THIS SYSTEM  
WILL BRING A RAPID WARMING TREND FROM THE SOUTHWEST/GREAT BASIN  
INTO THE NORTHERN-CENTRAL PLAINS DURING THE LATTER HALF OF THE  
WEEK. THE CENTRAL/NORTHERN WEST COAST SHOULD SEE BELOW NORMAL  
HIGHS BY FRIDAY WITH THE UPPER TROUGH NEARING THAT REGION. THE  
SYSTEM EMERGING FROM THE WEST INTO THE PLAINS MAY PRODUCE AREAS OF  
BRISK TO STRONG WINDS DURING THE FIRST PART OF THE WEEK,  
CONTRIBUTING TO INCREASING WILDFIRE RISK OVER AND WEST OF THE  
SOUTHERN ROCKIES. CHECK THE STORM PREDICTION CENTER FIRE WEATHER  
OUTLOOKS FOR THE LATEST INFORMATION.  
 
RAUSCH  
 
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, 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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