778  
FXUS21 KWNC 021832  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT JUNE 02 2026  
 
SYNOPSIS: MID-LEVEL HIGH PRESSURE FORECAST OVER SOUTHERN CANADA IS EXPECTED TO  
BRING ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE LOWER 48, WITH A LINGERING  
POTENTIAL FOR EXTREME HEAT CONDITIONS OVER PARTS OF THE GREAT PLAINS,  
MISSISSIPPI VALLEY, AND GREAT LAKES HEADING INTO NEXT WEEK. THE COMBINATION OF  
UNSEASONABLE LATE SPRING WARMTH AND INADEQUATE RAINFALL AMOUNTS SUPPORTS THE  
CONTINUATION OF A RAPID ONSET DROUGHT (ROD) RISK OVER PORTIONS OF THE  
MISSISSIPPI AND OHIO VALLEYS AND GREAT LAKES.  
 
HAZARDS  
 
SLIGHT RISK OF EXTREME HEAT FOR PORTIONS OF THE NORTHERN AND CENTRAL PLAINS,  
UPPER AND MIDDLE MISSISSIPPI AND OHIO VALLEYS, AND GREAT LAKES REGION, WED-THU,  
JUN 10-11.  
 
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF COASTAL CALIFORNIA AND THE PACIFIC  
NORTHWEST, WED-FRI, JUN 10-12.  
 
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE COASTAL SOUTHEAST, AND  
FLORIDA, WED-THU, JUN 10-11.  
 
RAPID ONSET DROUGHT POSSIBLE FOR PARTS OF THE UPPER AND MIDDLE MISSISSIPPI  
VALLEY, OHIO VALLEY, AND GREAT LAKES REGION.  
 
DETAILED SUMMARY  
 
FOR FRIDAY JUNE 05 - TUESDAY JUNE 09:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
FOR WEDNESDAY JUNE 10 - TUESDAY JUNE 16: AT THE START OF WEEK-2, THERE  
CONTINUES TO BE AGREEMENT BETWEEN THE GEFS AND ECMWF ENSEMBLE MEAN 500-HPA  
HEIGHT FORECASTS FAVORING A DEAMPLIFYING RIDGE CENTER TO THE SOUTH OF HUDSON  
BAY, WITH A LARGE COVERAGE OF POSITIVE HEIGHT DEPARTURES OVERSPREADING MUCH OF  
THE ENTIRE CONUS. AS THE ANOMALOUS RIDGE CENTER WEAKENS AND SHIFTS EASTWARD TO  
THE CANADIAN MARITIMES, THESE ENSEMBLE MEAN SOLUTIONS ARE NOW BEGINNING TO  
FAVOR MORE OF A SPLIT FLOW PATTERN TAKING SHAPE OVER THE EASTERN U.S AND  
WESTERN ATLANTIC, WITH THE ECMWF DEPICTING A CLOSED MID-LEVEL LOW THAT  
TEMPORARILY CUTS OFF FROM THE MEAN CIRCULATION. ADDITIONALLY, MORE MID-LEVEL  
TROUGHING IS FEATURED UPSTREAM IN BOTH THE GEFS AND ECMWF, WHERE LOWERING  
HEIGHTS OVER THE WEST COAST LOOKS TO BETTER ISOLATE THE RIDGE AXIS ACROSS THE  
CENTRAL CONUS EARLY IN THE PERIOD. OVER TIME, THE ECMWF STILL MAINTAINS A  
COMPARABLY MORE PROGRESSIVE PATTERN THAN THE GEFS, NAMELY WITH AN ANOMALOUS  
500-HPA RIDGE CENTER INITIALLY FAVORED OVER THE EASTERN PACIFIC THAT SHIFTS  
EASTWARD INTO THE NORTHWESTERN CONUS AND SOUTHWESTERN CANADA. TAKEN TOGETHER,  
THERE IS CONTINUED FORECAST CONFIDENCE FOR ABOVE-NORMAL TEMPERATURES AND  
POSSIBLE EXTREME HEAT CONDITIONS OVER THE NORTH-CENTRAL CONUS IN PROXIMITY TO  
THE ANOMALOUS RIDGE CENTER OVER SOUTHERN CANADA, WITH HEAT RISKS POSSIBLY  
EMERGING OVER THE WEST COAST LATER IN WEEK-2. BOOKENDING MEAN TROUGHS OVER THE  
WESTERN AND EASTERN CONUS SUPPORTS THE POTENTIAL FOR MORE UNSETTLED WEATHER  
EARLY IN WEEK-2, WITH COOLER MEAN TEMPERATURE SOLUTIONS BEING FAVORED OVER THE  
SOUTHEASTERN CONUS RELATIVE TO PREVIOUS MODEL GUIDANCE.  
 
A SLIGHT RISK OF EXTREME HEAT REMAINS POSTED FOR THE NORTH-CENTRAL CONUS WHERE  
THE GEFS AND ECMWF PROBABILISTIC EXTREME TOOLS MOST AGREE IN PERCENTILE SPACE,  
AND SHOW INCREASED CHANCES (20-40%) FOR DAYTIME TEMPERATURES EXCEEDING THE 85TH  
CLIMATOLOGICAL PERCENTILE. THE HIGHLIGHTED SLIGHT RISK AREA REMAINS VALID  
THROUGH JUN 11 AND CAPTURES THE STRONGEST POSITIVE TEMPERATURE DEPARTURES  
FAVORED ALONG WITH MODEST SUPPORT FOR THE HEAT INDEX VALUES POTENTIALLY  
REACHING 100 (105) DEG F ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI  
VALLEY (CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY). DUE TO THE POTENTIAL FOR  
TROUGHING UNDERNEATH THE RIDGE CENTER, ITS COVERAGE IS REDUCED TO EXCLUDE MORE  
OF THE OHIO VALLEY. SIMILAR TO YESTERDAY, THE ECMWF PET CONTINUES TO FEATURE  
GROWING HEAT SIGNALS OVER THE WEST COAST AND THE INTERIOR WEST TOWARDS THE  
MIDDLE OF THE PERIOD TIED TO THE ENCROACHING RIDGE CENTER FROM THE EASTERN  
PACIFIC. WHILE THE GEFS AND GEFSAI FAVORS THE EMERGENCE OF ABOVE-NORMAL  
TEMPERATURES OVER THE WEST COAST, AN ACCOMPANYING HEAT RISK CONTINUES TO BE  
LESS SUPPORTED IN THE RAW AND CALIBRATED TOOLS, PRECLUDING ANY CORRESPONDING  
TEMPERATURES HAZARDS IN BEING ISSUED IN THE UPDATED OUTLOOK. HOWEVER, THIS  
POTENTIAL WILL CONTINUE TO BE CLOSELY MONITORED IN UPCOMING HAZARD OUTLOOKS.  
 
 
 
OVER THE PAST SEVERAL WEEKS, PRECIPITATION HAS BEEN QUITE LIMITED OVER PORTIONS  
OF THE GREAT LAKES REGION AND MIDDLE AND UPPER MISSISSIPPI VALLEY FOLLOWING A  
WET SPRING IN THESE REGIONS. THE U.S. DROUGHT MONITOR SHOWS AN EXPANSION OF  
ABNORMALLY DRY CONDITIONS INTO PORTIONS OF MINNESOTA, WISCONSIN, EASTERN IOWA,  
NORTHERN ILLINOIS, AND ADJACENT INDIANA IN ITS LATEST UPDATE. ALTHOUGH NEAR TO  
SLIGHTLY ABOVE-NORMAL PRECIPITATION IS FAVORED DURING WEEK-2, THE LACK OF TOTAL  
PRECIPITATION FORECAST COMBINED WITH FAVORED ABOVE-NORMAL TEMPERATURES TO DRIVE  
INCREASED EVAPORATION RATES SUPPORTS THE CONTINUATION OF RAPID ONSET DROUGHT  
(ROD) RISK OVER THIS PART OF THE COUNTRY.  
 
WITH BETTER MODEL AGREEMENT FAVORING MORE TROUGHING OVER THE WEST COAST EARLY  
IN THE PERIOD, A SLIGHT RISK OF HIGH WINDS IS ADDED TO THE OUTLOOK OVER PARTS  
OF COASTAL CALIFORNIA AND THE PACIFIC NORTHWEST FOR EARLY WEEK-2 (JUN 10-12).  
THIS HAZARD IS SUPPORTED BY BOTH THE GEFS AND ECMWF PETS, WHICH HAVE COME INTO  
BETTER AGREEMENT DEPICTING INCREASED CHANCES FOR WIND SPEEDS EXCEEDING THE 85TH  
PERCENTILE, AS WELL AS MEAN SURFACE PATTERNS FAVORED IN THE ENSEMBLE WHICH  
DEPICT PERIODS OF STRENGTHENING PRESSURE GRADIENTS ALONG PARTS OF THE WEST  
COAST.  
 
OVER THE WESTERN ATLANTIC, THERE IS GROWING GUIDANCE SUPPORT FOR CYCLONIC  
SURFACE FLOW AND THE POTENTIAL COASTAL LOW DEVELOPMENT TIED TO THE TROUGHING  
FAVORED UNDERNEATH THE RIDGE CENTER OVER SOUTHEASTERN CANADA. WHILE THIS  
DEVELOPMENT IS RATHER NOVEL IN THE GUIDANCE, A MORE COHERENT PRECIPITATION  
RESPONSE IS DEPICTED IN SOME OF THE TOOLS LATE IN WEEK-1 THAT PERSISTS INTO  
EARLY WEEK-2. UNCALIBRATED PRECIPITATION TOOLS SHOW THE GREATEST SIGNALS FOR  
PRECIPITATION EXCEEDANCE MOSTLY OFFSHORE OF THE LOWER EASTERN SEABOARD, HOWEVER  
THERE IS SUPPORT IN THE GEFS PET FOR A HEAVY PRECIPITATION RISK WHICH EXTENDS  
INLAND OVER THE COASTAL CAROLINAS SOUTHWARD TO THE FLORIDA PENINSULA. GIVEN  
THIS, AND THE PREVAILING PATTERN FAVORED, A SLIGHT RISK OF HEAVY PRECIPITATION  
IS ADDED TO THE OUTLOOK, VALID FOR JUN 10-11. SHOULD ANY HEAVY PRECIPITATION  
BE REALIZED, LOCALIZED FLASH FLOODING IS POSSIBLE WITHIN THE HIGHLIGHTED AREA.  
 
OVER THE EASTERN PACIFIC, THE NATIONAL HURRICANE CENTER (NHC) CONTINUES TO  
MONITOR TWO AREAS FOR FORMATION IN THE EASTERN PACIFIC, WITH ONE LOCATED TO THE  
SOUTH OF MEXICO (40% CHANCES FOR DEVELOPMENT DURING THE NEXT SEVEN DAYS).  
SHOULD ANY DEVELOPMENT OCCUR NEXT WEEK ASSOCIATED WITH THE AREA SOUTH OF  
MEXICO, A NORTHWESTWARD TRACK NEARING THE GULF OF CALIFORNIA COULD BRING  
ENHANCED MOISTURE AND INCREASED PRECIPITATION INTO THE LOWER FOUR CORNERS. THE  
ECMWF ENSEMBLE DOES FAVOR AN INCREASE IN PRECIPITABLE WATER EXTENDING POLEWARD  
FROM WESTERN MEXICO ASSOCIATED WITH THIS SCENARIO LATE IN WEEK-2, HOWEVER NO  
CORRESPONDING HAZARDS ARE POSTED GIVEN A LACK OF SUPPORT IN THE PRECIPITATION  
TOOLS AS WELL AS GENERAL HIGH UNCERTAINTY AT THIS LEAD.  
 
 
 
IN ALASKA, RIVER ICE BREAKUP SEASON IS ENDING, BUT MANY RIVERS NORTH OF THE  
BROOKS RANGE REMAIN ICEBOUND. RIVER BREAKUP FLOODING CAN OCCUR WITH LITTLE OR  
NO NOTICE AS CONDITIONS ON FROZEN RIVERS CAN CHANGE QUICKLY, SO PLEASE CHECK  
WITH THE ALASKA PACIFIC RIVER FORECAST CENTER FOR THE LATEST CONDITIONS AND  
ADVISORIES.  
 
FORECASTER: NICK NOVELLA  
 

 
 
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