742  
FXUS21 KWNC 071805  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT JUNE 07 2026  
 
SYNOPSIS: STRONG MID-LEVEL HIGH PRESSURE NEAR THE WEST COAST INCREASES THE RISK  
OF A MULTI-DAY HEAT WAVE FOR PORTIONS OF THE WEST DURING MID-JUNE. A  
SLOW-MOVING COLD FRONT LEADS TO AN ELEVATED CHANCE OF LOCALLY HEAVY  
PRECIPITATION ACROSS MUCH OF THE EASTERN AND SOUTH-CENTRAL CONTIGUOUS U.S.  
(CONUS) FROM JUNE 15 TO 17. LATER IN THE OUTLOOK PERIOD, A WARMING TREND IS  
EXPECTED ACROSS THE SOUTHEAST.  
 
HAZARDS  
 
MODERATE RISK OF EXTREME HEAT FOR PARTS OF THE PACIFIC NORTHWEST, MON-TUE, JUN  
15-16.  
 
SLIGHT RISK OF EXTREME HEAT FOR PARTS OF THE WEST, MON-THU, JUN 15-18.  
 
SLIGHT RISK OF EXTREME HEAT FOR PARTS OF THE MID-ATLANTIC AND NORTHEAST, MON,  
JUN 15.  
 
SLIGHT RISK OF EXTREME HEAT FOR PARTS OF THE SOUTHEAST, FRI-SUN, JUN 19-21.  
 
SLIGHT RISK OF HEAVY PRECIPITATION FOR MUCH OF THE EASTERN AND SOUTH-CENTRAL  
CONUS, MON-WED, JUN 15-17.  
 
RAPID ONSET DROUGHT POSSIBLE FOR PARTS OF NORTHEASTERN ILLINOIS AND  
NORTHWESTERN INDIANA.  
 
DETAILED SUMMARY  
 
FOR WEDNESDAY JUNE 10 - SUNDAY JUNE 14:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
FOR MONDAY JUNE 15 - SUNDAY JUNE 21: THE ECENS, GEFS, AND CMCE REMAIN IN GOOD  
AGREEMENT AND VERY CONSISTENT THAT A 500-HPA RIDGE STRENGTHENS LATER NEXT WEEK  
OVER THE NORTHEASTERN PACIFIC. THIS MID-LEVEL RIDGE PEAKS IN STRENGTH ON DAY 7  
(JUNE 14), BUT THE PREFERRED ECENS AND CMCE DEPICT 500-HPA HEIGHTS OF 582 DM  
PERSISTING OVER THE PACIFIC NORTHWEST THROUGH JUNE 16. THESE MODEL SOLUTIONS  
HAVE DAILY HEIGHT DEPARTURES OF MORE THAN +120 METERS IN WESTERN PARTS OF  
OREGON AND WASHINGTON, WHICH SIGNALS AN ENHANCED RISK OF A MULTI-DAY HEAT WAVE  
FOR PORTLAND AND SEATTLE. BASED ON THE GOOD MODEL AGREEMENT ON THIS ANOMALOUSLY  
STRONG 500-HPA RIDGE FOR JUNE AND A 40% (GEFS) TO 60% (ECENS) CHANCE OF MAXIMUM  
TEMPERATURES EXCEEDING THE 85TH PERCENTILE ACCORDING TO THE PROBABILISTIC  
EXTREME TOOLS (PETS), A MODERATE RISK OF EXTREME HEAT CONTINUES FOR PARTS OF  
THE PACIFIC NORTHWEST ON JUNE 15 AND 16. IN ADDITION, THE NATIONAL BLEND OF  
MODELS SHOWS NEAR RECORD OR RECORD HIGHS OF 95F IN PORTLAND AND 87F AT SEATTLE  
ON JUNE 15. SINCE THE NWS HEATRISK TOOL HAS LESS THAN A 40% CHANCE OF MAJOR  
HEAT-RELATED IMPACTS AND THE PETS ONLY HAVE A 20 TO 30% CHANCE THAT MAXIMUM  
TEMPERATURES REACH 100 DEGREES F, THE MODERATE RISK OF EXTREME HEAT IS  
DISCONTINUED FOR THE SACRAMENTO VALLEY OF NORTHERN CALIFORNIA. BASED ON THE NWS  
HEATRISK TOOL AND PETS (20-40% CHANCE OF EITHER MAJOR HEAT-RELATED IMPACTS OR  
MAXIMUM TEMPERATURES EXCEEDING THE 85TH PERCENTILE), A BROAD SLIGHT RISK OF  
EXTREME HEAT EXTENDS SOUTH THROUGH THE CENTRAL VALLEY OF CALIFORNIA AND DESERT  
SOUTHWEST. THE SLIGHT RISK OF EXTREME HEAT ENDS ON JUNE 18 AS THE 500-HPA RIDGE  
IS FORECAST TO WEAKEN AND SHIFT AWAY FROM THE WEST COAST.  
 
THE POTENTIAL HEAT WAVE ACROSS THE MID-ATLANTIC AND NORTHEAST LATER NEXT WEEK  
IS EXPECTED TO TIME OFF AT THE BEGINNING OF WEEK-2. HOWEVER, THE ECENS PET (20%  
CHANCE OF MAXIMUM TEMPERATURES > 90F) SUPPORTS THE CONTINUATION OF THE SLIGHT  
RISK OF EXTREME HEAT FOR THE GREATER NYC AREA ON JUNE 15TH. THIS SLIGHT RISK  
AREA EXTENDS SOUTH THROUGH THE MID-ATLANTIC WHERE THERE IS AN ELEVATED CHANCE  
THAT HEAT INDEX VALUES REACH 105F.  
 
THE AMPLIFIED 500-HPA TROUGH UPSTREAM OVER THE MIDWEST, A SLOW-MOVING/STALLED  
SURFACE FRONT, AND ANOMALOUSLY HIGH MOISTURE CONTENT INCREASE THE CHANCE OF  
LOCALLY HEAVY RAINFALL WITH ANY CONVECTION ACROSS MUCH OF THE EAST EXTENDING  
WEST TO THE CENTRAL AND SOUTHERN GREAT PLAINS. THE SLIGHT RISK OF HEAVY  
PRECIPITATION, VALID JUNE 15-17, GENERALLY FOLLOWED WHERE THE MULTI-MODEL  
ENSEMBLE MEANS DEPICT A SLOW-MOVING OR STALLED FRONT AND THE PETS HAVE 3-DAY  
AMOUNTS EXCEEDING THE 85TH PERCENTILE. THUNDERSTORMS ARE LIKELY TO BE CAPABLE  
OF PRODUCING MORE THAN 1 INCH PER 24 HOURS. A BROAD SLIGHT RISK AREA IS  
NECESSARY DUE TO THE UNCERTAINTY IN CONVECTIVE RAINFALL AT THIS TIME LEAD  
DURING JUNE. GIVEN THE ANOMALOUSLY HIGH MOISTURE, ANY SLOW-MOVING THUNDERSTORM  
COULD TRIGGER FLASH FLOODING.  
 
BEGINNING ON JUNE 17 OR 18, THE ECENS AND GEFS FAVOR A RETROGRESSION OF THE  
LONGWAVE PATTERN WHICH LEADS TO A STRENGTHENING SUBTROPICAL RIDGE OVER THE  
SOUTHEAST. THE GEFS IS MOST BULLISH WITH A WARMING TREND AND DEPICTS MAXIMUM  
TEMPERATURES ABOVE 95 DEGREES F FROM THE COASTAL PLAIN OF THE CAROLINAS AND  
GEORGIA SOUTH INTO THE FLORIDA PENINSULA. BASED ON THE CALIBRATED HEAT INDEX  
TOOL (20-40% CHANCE OF HEAT INDEX VALUES TO EXCEED THE 90TH PERCENTILE AND  
105F), A SLIGHT RISK OF EXTREME HEAT IS POSTED FOR PARTS OF THE SOUTHEAST FROM  
JUNE 19 TO 21.  
 
30-DAY PRECIPITATION HAS AVERAGED LESS THAN 50 PERCENT OF NORMAL ACROSS MUCH OF  
THE MIDWEST. THE U.S. DROUGHT MONITOR, VALID JUNE 2, DEPICTS AN EXPANDING  
COVERAGE OF ABNORMAL DRYNESS (D0) ACROSS THIS REGION AND MODERATE DROUGHT (D1)  
IN NORTHERN ILLINOIS AND SOUTHERN WISCONSIN. RAPID ONSET DROUGHT (ROD) IS  
UNDERWAY WITH THIS LACK OF ADEQUATE PRECIPITATION, WARMER TEMPERATURES, AND  
INCREASING WATER DEMAND AT THIS TIME OF YEAR. THE ROD HAZARD, CURRENTLY  
DEPICTED IN NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA, MAY BE DISCONTINUED  
ON MONDAY AS AN INCREASINGLY WET PATTERN IS FORECAST DURING THE NEXT TWO WEEKS.  
 
 
 
IN ALASKA, RIVER ICE BREAKUP SEASON IS ENDING AND EVEN THE RIVERS ACROSS THE  
NORTH SLOPE ARE BEGINNING TO OPEN. 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: BRAD PUGH  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page