023
FXUS01 KWBC 180812
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 AM EDT TUE AUG 18 2026
VALID 12Z TUE AUG 18 2026 - 12Z THU AUG 20 2026
...POTENTIAL FOR SEVERE STORMS ACROSS THE CENTRAL PLAINS WITH
HEAVY AND FLASH FLOODING THREATS ACROSS THE MIDWEST; SEVERE STORMS
ACROSS MID-MISSISSIPPI VALLEY WEDNESDAY TO WEDNESDAY NIGHT...
...DANGEROUS HEAT PERSISTS IN THE SOUTH AND SOUTHEAST WHILE
BUILDING INTO THE SOUTHWEST...
AS AN UPPER-LEVEL HIGH PRESSURE SYSTEM CONTINUES TO SUSTAIN THE
HEATWAVE ACROSS THE SOUTH AND SOUTHEAST, A COOL AIR MASS FROM
CANADA IS DIPPING INTO THE NORTHERN TIER STATES. STRONGER
UPPER-LEVEL TROUGHING ASSOCIATED WITH THE COOL AIR MASS WAS ABLE
TO PUSH THE UNRELENTING HEAVY RAIN AND THUNDERSTORMS AWAY FROM THE
MIDWEST AND THE OHIO VALLEY, AND OFF THE EAST COAST THIS MORNING.
AS THIS COOL AIR MASS ADVANCES DEEPER INTO THE NORTHERN PLAINS, A
NEW ROUND OF HEAVY SHOWERS AND STRONG TO SEVERE THUNDERSTORMS
DEVELOPING ACROSS THE NORTHERN PLAINS WILL MOVE TOWARD THE MIDWEST
INTO THIS EVENING. MEANWHILE, A SLIGHT RISK OF SEVERE
THUNDERSTORMS IS FORECAST FARTHER SOUTH ACROSS THE CENTRAL PLAINS
AS THE COLD FRONT FROM THE NORTH COLLIDES WITH A WARM FRONT
ARRIVING FROM THE SOUTH. NUMEROUS SHOWERS AND THUNDERSTORMS ARE
FORECAST FROM CENTRAL NEBRASKA AND NORTHERN KANSAS TO AS FAR EAST
AS THE MISSISSIPPI RIVER. WPC HAS A SLIGHT RISK OUT FOR EXCESSIVE
RAINFALL IN THE HEART OF THE MIDWEST, WHILE SPC HAS A SLIGHT RISK
FOR SEVERE STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING
WINDS FARTHER SOUTHWEST ACROSS THE CENTRAL PLAINS LATER TODAY INTO
TONIGHT. ELSEWHERE, THE SAME NORTHERN TIER COLD FRONT WILL TRACK
ACROSS THE GREAT LAKES, BRINGING MORE SHOWERS AND STORMS TO THE
REGION. HIT-OR-MISS STORMS WILL ALSO BE POSSIBLE ACROSS THE
CENTRAL AND SOUTHERN ROCKIES, AS WELL AS THE CENTRAL HIGH PLAINS.
THE COLD FRONT CONTINUES TO TRACK EAST TOWARDS THE NORTHEAST ON
WEDNESDAY WHILE LOW PRESSURE IN THE SOUTHERN PLAINS HELPS PRODUCE
ADDITIONAL STORMS FROM THE CENTRAL ROCKIES TO AS FAR EAST AS THE
OHIO VALLEY THROUGH WEDNESDAY NIGHT. SPC HAS A SLIGHT RISK OF
SEVERE STORMS FOR THE MID-MISSISSIPPI VALLEY IN ANTICIPATION OF
HEAVY THUNDERSTORMS MAINLY FROM LATER WEDNESDAY TO WEDNESDAY NIGHT
AHEAD OF THE COLD FRONT.
REGARDING TEMPERATURES, THE SOUTHERN TIER OF THE LOWER 48 REMAINS
MIRED IN A STEAMY AIR-MASS EVEN BY MID-LATE AUGUST STANDARDS.
RECORD HIGHS AND RECORD WARM MINIMUM TEMPERATURES WILL BE COMMON
WITH THE SOUTHEAST AT THE HEART OF THE ANOMALOUS HEAT THROUGH
TODAY. BY WEDNESDAY, AS UPPER-LEVEL RIDGING STRENGTHENS OVER THE
SOUTHWEST, SOME CASES OF RECORD BREAKING WARMTH ARE EXPECTED IN
THE DESERT SOUTHWEST AND SOUTHERN PLAINS. EXTREME HEAT WARNINGS
ARE IN EFFECT FOR MUCH OF THE DESERT SOUTHWEST, WITH WIDESPREAD
EXTREME HEAT WARNINGS AND HEAT ADVISORIES STRETCHING FROM THE
DALLAS/FORT WORTH AND OKLAHOMA CITY METRO AREAS EASTWARD TO THE
SOUTHEAST COAST. OVERNIGHT LOWS WILL BE SO WARM (LOW 80S IN SOME
CASES) THAT, WHEN COMBINED WITH OPPRESSIVE DEW POINTS,
LITTLE-TO-NO RELIEF FROM THE SCORCHING DAYTIME HIGHS WILL BE
AVAILABLE. RESIDENTS ARE ADVISED TO FOLLOW PROPER HEAT SAFETY TIPS
BY LIMITING OUTDOOR ACTIVITY, STAYING HYDRATED, ENSURING ACCESS TO
A/C OR COOLING CENTERS, AND CHECKING ON VULNERABLE FRIENDS,
NEIGHBORS, AND FAMILY MEMBERS.
KONG/MULLINAX
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
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