700
FXUS21 KWNC 031939
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JUNE 03 2026
SYNOPSIS: MID-LEVEL HIGH PRESSURE FORECAST OVER SOUTH-CENTRAL OR SOUTHEASTERN
CANADA IS EXPECTED TO BE SLOWLY DEAMPLIFYING EARLY IN WEEK-2, WITH A LINGERING
POTENTIAL FOR EXTREME HEAT ACROSS PARTS OF THE CENTRAL AND NORTHEASTERN
CONTIGUOUS UNITED STATES (CONUS) EARLY IN THE PERIOD. THE ABOVE-NORMAL
TEMPERATURES, IN COMBINATION WITH DEFICIENT RAINFALL AND ANTECEDENT SHORT-TERM
DRYNESS, INCREASES THE POTENTIAL FOR RAPID ONSET DROUGHT (ROD) OVER THE
SOUTHWESTERN GREAT LAKES REGION AND UPPER MIDWEST. FARTHER SOUTH, A LOW
PRESSURE SYSTEM IS EXPECTED TO SLOWLY DRIFT FROM NEAR SOUTHERN FLORIDA TOWARD
THE SOUTHEAST AND GULF COAST, BRINGING A RISK OF HEAVY PRECIPITATION TO MOST OF
FLORIDA AND ADJACENT AREAS THROUGH THE MIDDLE OF WEEK-2. MEANWHILE, A MID-LEVEL
RIDGE IS FORECAST TO SLOWLY AMPLIFY NEAR THE WEST COAST, ACCOMPANIED BY
GRADUALLY INCREASING TEMPERATURES AND AN ELEVATED RISK OF EXTREME HEAT IN THE
SOUTHWEST AND THE CALIFORNIA VALLEYS BY THE MIDDLE OF WEEK-2.
HAZARDS
SLIGHT RISK OF EXTREME HEAT ACROSS THE CENTRAL NORTHERN PLAINS, PARTS OF THE
UPPER AND MIDDLE MISSISSIPPI AND OHIO VALLEYS, THE GREAT LAKES REGION, AND
PARTS OF THE MID-ATLANTIC AND NORTHEAST, THU-FRI, JUN 11-12, 2026.
SLIGHT RISK OF EXTREME HEAT IN THE DESERT SOUTHWEST AND THE CALIFORNIA VALLEYS,
SAT-WED, JUN 13-17, 2026.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF COASTAL CALIFORNIA AND THE PACIFIC
NORTHWEST, THU-FRI, JUN 11-12, 2026.
SLIGHT RISK OF HEAVY PRECIPITATION OVER MOST OF FLORIDA, SOUTHERN GEORGIA, AND
ADJACENT AREAS, THU-MON, JUN 11-15, 2026.
RAPID ONSET DROUGHT POSSIBLE FOR PARTS OF THE UPPER AND MIDDLE MISSISSIPPI
VALLEY, OHIO VALLEY, AND GREAT LAKES REGION.
DETAILED SUMMARY
FOR SATURDAY JUNE 06 - WEDNESDAY JUNE 10:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY JUNE 11 - WEDNESDAY JUNE 17: AT THE START OF WEEK-2, THE MODELS
ALL DEPICT A MID LEVEL RIDGE STRETCHING FROM CANADA SOUTHWARD INTO THE INTERIOR
CONUS THAT IS IN THE PROCESS OF DEAMPLIFYING AND PUSHING EASTWARD. AS A RESULT,
UNUSUALLY HOT WEATHER THAT BUILT INTO THE CENTRAL CONUS DURING WEEK-1 WILL BE
ON THE WANE, BUT A LINGERING RISK OF EXTREME HEAT IS EXPECTED TO CONTINUE INTO
THE FIRST FEW DAYS OF WEEK-2. FORECAST UNCERTAINTY IS INTRODUCED BY POOR MODEL
AGREEMENT ON THE LOCATION AND EVOLUTION OF THIS MID-LEVEL RIDGE, WHICH LOWERS
FORECAST CONFIDENCE IN ANY SPECIFIC AREA. THE 0Z GEFS MEAN SHOWS THE
DEAMPLIFYING RIDGE AXIS CONSIDERABLY FARTHER WEST ACROSS THE PLAINS OR
MISSISSIPPI VALLEY WHILE THE CANADIAN ENSEMBLE (CMCE) AND EUROPEAN ENSEMBLE
(ECENS) MEANS PLACE THE AXIS FARTHER EAST AT THE OUTSET OF WEEK-2. IN ADDITION,
THE ECENS AND GEFS MEANS MAINTAIN A BIT MORE AMPLITUDE THAN THE CMCE MEAN,
WHICH FLATTENS THE RIDGE AND SHEARS IT EASTWARD MORE QUICKLY. THESE PATTERN
DISCREPANCIES HAVE A SIGNIFICANT IMPACT ON TEMPERATURE FORECASTS OVER THE
CENTRAL AND EASTERN CONUS. SURFACE TEMPERATURE ANOMALY FORECASTS AND THE
PROBABILISTIC EXTREMES TOOLS (PETS) FROM THE GEFS START WEEK-2 WITH A RISK OF
EXTREME HEAT CENTERED OVER THE PLAINS OR MISSISSIPPI VALLEY EARLY WEEK-2 WHILE
THE TOOLS DERIVED FROM THE ECENS CENTER THE GREATEST RISK SIGNIFICANTLY FARTHER
EAST, OVER THE EASTERN GREAT LAKES AND INTERIOR NORTHEAST. THESE PATTERNS ARE
CONSIDERABLY OUT OF PHASE. INTERNAL EXCESSIVE HEAT GUIDANCE DERIVED FROM THE
GEFS PLACES THE GREATEST CHANCES FOR EXTREME HEAT OVER THE NORTH-CENTRAL GREAT
PLAINS AND ADJACENT MISSISSIPPI VALLEY, WHICH IS NEAR WHERE THE SAME TOOL BASED
ON THE ECENS SHOWS RELATIVELY LOWER CHANCES THERE THAN IN AREAS FARTHER EAST
AND WEST. THE BOTTOM LINE IS THAT THERE IS BROAD AGREEMENT AMONG THE TOOLS
SUPPORTING AN ENHANCED RISK OF EXTREME HEAT, BUT LITTLE AGREEMENT ON EXACTLY
WHERE THIS WILL OCCUR. OFFICIALLY, A SLIGHT RISK OF EXTREME HEAT IS POSTED
ACROSS A BROAD AREA COVERING MUCH OF THE CENTRAL AND EASTERN CONUS FOR THE
FIRST TWO DAYS OF WEEK-2 BEFORE 500-HPA HEIGHTS DROP TO NEAR NORMAL, ENDING THE
RISK. THE COVERAGE ESSENTIALLY COMBINES THE HIGHER RISK AREAS IDENTIFIED BY THE
DISPARATE TOOLS, AS THERE IS NO OVERRIDING REASON TO FAVOR ONE SOLUTION OVER
ANOTHER AT THIS TIME.
OVER THE PAST SEVERAL WEEKS, PRECIPITATION HAS BEEN SIGNIFICANTLY BELOW NORMAL
OVER PORTIONS OF THE WESTERN GREAT LAKES REGION AND ADJACENT PORTIONS OF THE
MISSISSIPPI VALLEY. THE U.S. DROUGHT MONITOR HIGHLIGHTS ABNORMALLY DRY
CONDITIONS IN THIS REGION. THE WEEK-2 PRECIPITATION OUTLOOK DEPICTS MARGINALLY
ENHANCED CHANCES FOR ABOVE-NORMAL PRECIPITATION ACROSS THIS AREA, BUT THE
EXPECTED HOT WEATHER AND ASSOCIATED INCREASES IN EVAPORATIVE MOISTURE LOSSES,
IN CONJUNCTION WITH THE ELEVATED HUMAN AND ECOLOGICAL DEMAND FOR SURFACE WATER
INHERENT TO SUMMERTIME, MAKES IT LIKELY THAT THE PRECIPITATION WILL NOT BE
SUFFICIENT TO OFFSET SURFACE MOISTURE LOSSES. AS A RESULT, A POTENTIAL FOR
RAPID-ONSET DROUGHT (ROD) IS MAINTAINED ACROSS SOUTHEASTERN MINNESOTA,
NORTHEASTERN IOWA, SOUTHWESTERN WISCONSIN, NORTHERN ILLINOIS, AND NORTHWESTERN
INDIANA. THE DROUGHT MONITOR WILL BE UPDATED TOMORROW, AT WHICH TIME THE
CHANCES FOR ROD WILL BE RE-ASSESSED.
MODELS REMAIN IN GOOD AGREEMENT FAVORING MID-LEVEL TROUGHING OVER THE WEST
COAST EARLY WEEK-2. THIS IS EXPECTED TO ESTABLISH LOW SURFACE PRESSURE OVER THE
INTERIOR WEST WHILE SURFACE HIGH PRESSURE BUILDS EASTWARD FROM THE NORTH
PACIFIC. THE RESULTING PRESSURE GRADIENT SUPPORTS A SLIGHT RISK OF HIGH WINDS
OVER PARTS OF COASTAL CALIFORNIA AND THE PACIFIC NORTHWEST EARLY WEEK-2 (JUN
11-12). SURFACE PRESSURE FORECASTS FROM THE ENSEMBLE MEANS HIGHLIGHT THIS
POTENTIAL, AND THE PETS DERIVED FROM THE GEFS AND ECENS SHOW ENHANCED CHANCES
FOR WINDS TO REACH THE TOP 15 PERCENT OF THE CLIMATOLOGICAL ENVELOPE. PETS,
WHICH HAVE COME INTO BETTER AGREEMENT DEPICTING INCREASED CHANCES FOR WIND
SPEEDS EXCEEDING THE 85TH PERCENTILE, ALONG WITH 20 TO LOCALLY 60 PERCENT
CHANCES FOR WIND SPEEDS TOPPING 20 MPH, WITH THE HIGHEST ODDS ALONG THE
IMMEDIATE COAST. CHANCES FOR WINDS ABOVE 25 MPH REACH AS HIGH AS 50 PERCENT
NORTHWEST OF SANTA ROSA, CA IN THE ECENS PET.
OVER THE WESTERN ATLANTIC, GUIDANCE INCREASINGLY SUPPORTS THE POTENTIAL FOR A
WAVE OF LOW PRESSURE TO DEVELOP. THE MODELS HAVE BEEN INCONSISTENT IN HANDLING
THE EVOLUTION OF THIS POTENTIAL SYSTEM, WHICH IS NOT UNEXPECTED GIVEN THE
RELATIVELY SUBTLE MID-LEVEL FEATURES THAT DETERMINE THE EVENTUAL EVOLUTION OF
LOW PRESSURE IN LOWER LATITUDES DURING SUMMER. TODAY, THERE IS GENERAL
AGREEMENT THAT THIS SYSTEM WILL BE AFFECTING SOUTH FLORIDA AT THE OUTSET OF
WEEK-2, MOVING SLOWLY NORTHWARD TOWARD SOUTHERN GEORGIA OR THE NORTHEASTERN
GULF COAST OVER THE NEXT SEVERAL DAYS. THIS CONSENSUS IS LONGER-LIVED AND
FARTHER WEST THAN THE CONSENSUS OF TOOLS YESTERDAY. THE PETS ARE NOT TOO
ENTHUSIASTIC ON THE POTENTIAL FOR HEAVY PRECIPITATION, BUT THE ECENS, GEFS, AND
ESPECIALLY THE DYNAMICAL EUROPEAN MODEL (ECMWF) ALL SHOW ENHANCED CHANCES FOR A
FEW INCHES OF RAIN TO FALL ON SOME AREAS AFFECTED BY THIS SYSTEM. A SLIGHT RISK
OF HEAVY PRECIPITATION IS POSTED FOR MOST OF FLORIDA, SOUTHERN GEORGIA, AND
SOME ADJACENT AREAS WHICH COULD BE AFFECTED BY THIS FEATURE, BUT THERE REMAINS
A LOT OF UNCERTAINTY AS INDICATED BY THE WIDE ARRAY OF POTENTIAL SCENARIOS
INDICATED BY THE INDIVIDUAL MEMBERS OF THE ENSEMBLES.
A MID-LEVEL TROUGH OVER THE WESTERN CONUS WILL BE PULLING AWAY FROM THE REGION
EARLY WEEK-2. IN ITS WAKE, MOST TOOLS DEPICT A MID-LEVEL RIDGE AMPLIFYING IN
THE EASTERN NORTH PACIFIC THAT BUILDS SLOWLY INTO THE WESTERN CONUS. AS THIS
EVOLVES, TEMPERATURES ARE EXPECTED TO SLOWLY INCREASE ACROSS THE WESTERN CONUS,
RESULTING IN A SLIGHT RISK OF EXTREME HEAT ACROSS THE DESERT SOUTHWEST AND
CALIFORNIA VALLEYS DURING THE MIDDLE AND LATTER PARTS OF WEEK-2. THE ECENS MEAN
IS CONSIDERABLY MORE ROBUST WITH THIS SOLUTION THAN THE GEFS AND CMCE MEANS,
BUT THE MEAN SOLUTION FROM THE NEW GEFS ARTIFICIAL INTELLIGENCE ENSEMBLE
(AIGEFS) SUPPORTS THE ECENS SCENARIO, ALONG WITH THE EUROPEAN ARTIFICIAL
INTELLIGENCE MODEL (ECMWF-AI) ENSEMBLE MEAN. TEMPERATURES ARE EXPECTED TO CLIMB
INTO THE LOW TO MIDDLE 100'S F AFTER THE FIRST COUPLE DAYS OF WEEK-2, WITH THE
ECENS MEAN FORECASTING TEMPERATURES OF 110 TO 115 DEG. F IN THE MOST ARID
LOCATIONS NEAR THE LOWER COLORADO RIVER AND NEAR THE MEXICAN BORDER.
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: RICH TINKER
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