159  
FXUS02 KWBC 241857  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
257 PM EDT FRI JUN 24 2022  
 
VALID 12Z MON JUN 27 2022 - 12Z FRI JUL 01 2022  
   
..OVERVIEW
 
 
GUIDANCE STILL AGREES THAT A BROAD UPPER LEVEL RIDGE OVER THE  
SOUTHERN HALF OF THE CONUS WILL BE IN PLACE THROUGH MUCH OF THE  
MEDIUM RANGE PERIOD, FORCING STORM TRACKS MAINLY THROUGH THE  
NORTHERN TIER. A VIGOROUS SHORTWAVE THROUGH THE UPPER  
MIDWEST/GREAT LAKES WILL AMPLIFY SOME AS IT MOVES INTO THE  
MID-ATLANTIC AND THE NORTHEAST EARLY NEXT WEEK, PUSHING A SURFACE  
COLD FRONT ACROSS THE EAST AND HELPING PRODUCE SHOWERS AND  
THUNDERSTORMS. BEHIND THIS, AMPLIFIED RIDGING SHOULD BUILD OVER  
THE NORTHWEST U.S., AND SLIDE INTO THE NORTHERN PLAINS AS A CLOSED  
LOW/UPPER TROUGH COULD SETTLE OVER THE PACIFIC NORTHWEST, PERHAPS  
BY AROUND WEDNESDAY. MEANWHILE, MONSOONAL MOISTURE WILL CONTINUE  
TO PERSIST INTO THE FOUR CORNERS REGION THROUGH MUCH OF THE  
PERIOD, WITH THE BEST POTENTIAL FOR HEAVIER TO EXCESSIVE RAINS TO  
REMAIN ACROSS THE SOUTH-CENTRAL ROCKIES INTO EARLY NEXT WEEK.  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
RECENT MODEL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH THE MEDIUM  
RANGE TIME FRAME FOR THE LARGE SCALE PATTERN DESCRIBED ABOVE AND  
ITS EVOLUTION. THIS INCLUDES A COUPLE OF ROUNDS OF TROUGHING OVER  
THE NORTHEASTERN U.S. AND RIDGING SHIFTING FROM THE NORTHWESTERN  
TO NORTH-CENTRAL U.S. BEHIND. SOME SLIGHTLY LARGER DIFFERENCES ARE  
INDICATED IN MODEL GUIDANCE WITH THE TRACK OF AN EASTERN PACIFIC  
UPPER LOW THAT SHOULD SHIFT INTO SOUTHWESTERN CANADA/NORTHWESTERN  
U.S. AROUND WEDNESDAY, AND CMC RUNS HAVE BEEN MOST CONSISTENT IN  
LEAVING ENERGY FARTHER WEST. THEN THERE ARE SOME PLACEMENT  
DIFFERENCES WITH THE CENTROID OF A CENTRAL CANADA/HUDSON BAY UPPER  
LOW, WITH THE GFS ON THE WESTERN SIDE WEDNESDAY-FRIDAY, WHICH  
COULD CAUSE MINOR DIFFERENCES OVER THE NORTHERN U.S. WITH  
TROUGHING AND SURFACE FRONTAL PLACEMENT. BUT THE OVERALL GOOD  
AGREEMENT ALLOWED FOR THE UPDATED WPC FORECAST TO USE A  
MULTI-MODEL DETERMINISTIC BLEND OF THE 00/06Z GFS RUNS AND 00Z  
ECMWF, CMC, AND UKMET, PHASING IN THE 00Z EC ENSEMBLE MEAN IN  
PLACE OF THE UKMET BY DAYS 6-7, BUT WITH A MAJORITY DETERMINISTIC  
BLEND. THIS CREATED A MIDDLE GROUND SOLUTION WITH DECENT  
CONTINUITY FROM THE PREVIOUS ISSUANCE.  
 
   
..SENSIBLE WEATHER/THREAT HIGHLIGHTS
 
 
ANOMALOUSLY HIGH MONSOONAL MOISTURE FOR THIS TIME OF YEAR, LIKELY  
TIED AT LEAST IN PART TO TROPICAL STORM CELIA IN THE EAST PACIFIC,  
WILL CONTINUE STREAMING INTO THE FOUR CORNERS STATES INTO EARLY  
NEXT WEEK. LOCALLY HEAVY TO EXCESSIVE RAINFALL WILL BE POSSIBLE  
EACH DAY, PARTICULARLY OVER SENSITIVE BURN SCAR AREAS AND  
CONSIDERING THE MULTIPLE DAY REPEATING NATURE OF THIS ACTIVITY.  
THE BEST CHANCE FOR IMPACTFUL RAINFALL LOOKS TO BE OVER PARTS OF  
SOUTHERN COLORADO/NEW MEXICO WITH FAVORABLE UPSLOPE FLOW  
INTERACTING WITH THE MOISTURE ALREADY IN PLACE. A SLIGHT RISK WAS  
MAINTAINED ACROSS NORTHERN NEW MEXICO ON THE EXPERIMENTAL DAY 4  
EXCESSIVE RAINFALL OUTLOOK FOR MONDAY WHERE GOOD MODEL AGREEMENT  
OVERLAPPED WITH AREAS THAT HAVE SEEN ANOMALOUS RAINFALL ALREADY.  
ACTIVITY THEN WANES AROUND TUESDAY-WEDNESDAY, BUT THERE MAY BE  
ANOTHER UPTICK IN MOISTURE BY THE LATTER PART OF NEXT WEEK.  
 
A COLD FRONT SHOULD BE FAIRLY PROGRESSIVE THROUGH THE EAST MONDAY,  
BUT SHOULD FOCUS ENOUGH MOISTURE AND INSTABILITY TO FUEL  
CONVECTION WITH POSSIBLY LOCALLY HEAVY RAINFALL. A SETTLING OF THE  
FRONT ACROSS THE GULF COAST, AS WELL AS THE NEXT COLD FRONT  
DROPPING INTO THE REGION, SHOULD ALLOW FOR ENHANCED RAINFALL INTO  
THE MIDDLE OF NEXT WEEK FROM FLORIDA TO ALONG THE GULF COAST AS  
AIDED BY PROTRACTED ONSHORE FETCH OF MOISTURE. ELSEWHERE,  
PROGRESSIVE FRONTS TRACKING ACROSS THE UPPER MIDWEST INTO THE  
UPPER GREAT LAKES SHOULD PRODUCE A COUPLE OF ROUNDS OF RAIN AND  
STORMS THROUGH THE WORKWEEK THERE, AND RAIN MAY ALSO FOCUS OVER  
THE CENTRAL PLAINS/MID-MISSISSIPPI VALLEY BY LATE WEEK AS A FRONT  
SHIFTS INTO THAT AREA.  
 
BY EARLY NEXT WEEK, TEMPERATURES ALL ACROSS THE SOUTH SHOULD  
FINALLY TREND BACK TOWARDS NORMAL. RELATIVELY COOLER TEMPERATURES  
WITH WELL BELOW NORMAL HIGHS ARE LIKELY TO BE MOST PERSISTENT OVER  
PARTS OF NEW MEXICO AND COLORADO GIVEN THE MONSOONAL CLOUDS AND  
RAIN COVERAGE. IN THE WEST, RIDGING THROUGH THE REGION SHOULD  
PRESENT AN EXCESSIVE HEAT THREAT ACROSS PARTS OF ESPECIALLY THE  
NORTHWEST INTO MONDAY WITH THE ABOVE NORMAL TEMPERATURES THEN  
WORKING THROUGH THE NORTHERN HALF OF THE ROCKIES, PLAINS, MIDWEST  
AND THEN EAST TUESDAY-NEXT FRIDAY AS WE HEAD INTO JULY.  
 
TATE/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 SOUTHERN ROCKIES, THE CENTRAL  
ROCKIES, THE SOUTHERN PLAINS, THE CENTRAL PLAINS, AND THE  
SOUTHWEST, MON, JUN 27.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE UPPER  
MISSISSIPPI VALLEY, THE NORTHERN PLAINS, AND THE NORTHERN ROCKIES.  
- EXCESSIVE HEAT ACROSS PORTIONS OF CALIFORNIA, THE CENTRAL GREAT  
BASIN, THE PACIFIC NORTHWEST, THE NORTHERN GREAT BASIN, AND THE  
SOUTHERN PLAINS, MON, JUN 27.  
 
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  
 

 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page