448
FXUS01 KWBC 220801
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 AM EDT SAT JUN 22 2024
VALID 12Z SAT JUN 22 2024 - 12Z MON JUN 24 2024
...HEAT WAVE FOCUS SHITS FROM THE MIDWEST/OHIO VALLEY INTO THE
MID-ATLANTIC STATES THIS WEEKEND...
...HEAVY RAIN AND FLASH FLOODING CONCERNS ACROSS THE UPPER GREAT
LAKES/MISSISSIPPI VALLEY SATURDAY AND NORTHERN NEW ENGLAND
SUNDAY...
...HEAT BUILDING ACROSS THE WEST THIS WEEKEND, MONSOON-LIKE
CONDITIONS FOR THE DESERT SOUTHWEST...
A HEAT WAVE WILL CONTINUE OVER MUCH OF THE EASTERN U.S. SOUTH OF A
QUASI-STATIONARY BOUNDARY AND UNDER THE INFLUENCE OF LONGWAVE
RIDGING ALOFT THIS WEEKEND. FORECAST HIGH TEMPERATURES SATURDAY
WILL GENERALLY BE IN THE MID- TO UPPER 90S FROM THE
CENTRAL/SOUTHERN PLAINS TO THE EAST COAST. THESE TEMPERATURES
REMAIN THE MOST ANOMALOUS AND DANGEROUS FOR EARLY SUMMER OVER
PORTIONS OF THE MIDWEST/OHIO VALLEY EAST TO THE MID-ATLANTIC.
HEAT-RELATED ADVISORIES AND WARNINGS ARE IN PLACE AS HUMIDITY WILL
BRING HEAT INDEX VALUES AS HIGH AS THE MID-100S. A POTENT
UPPER-LEVEL SHORTWAVE WILL HELP TO FINALLY PUSH THE BOUNDARY
SOUTHWARD SUNDAY, BRINGING WELCOME RELIEF TO MUCH OF THE
MIDWEST/OHIO VALLEY, WHILE THE MID-ATLANTIC CONTINUES TO SIMMER.
NUMEROUS RECORD-TYING/BREAKING HIGHS ARE POSSIBLE. IN ADDITION,
OVERNIGHT LOW TEMPERATURES WILL REMAIN TO THE MID- AND EVEN UPPER
70S, PROVIDING LITTLE RELIEF FROM THE HEAT OVERNIGHT. THE
COMBINATION OF THIS HEAT COMING EARLY IN THE SUMMER SEASON AND
PERSISTING OVER SEVERAL DAYS INCREASES THE LEVEL OF HEAT STRESS
FOR THOSE WITHOUT RELIABLE AIR CONDITIONING.
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL CONTINUE TO THE NORTH
ALONG THE QUASI-STATIONARY BOUNDARY DRAPED FROM NEW ENGLAND WEST
THROUGH THE GREAT LAKES AND INTO THE UPPER MISSISSIPPI VALLEY.
PLENTIFUL MOISTURE WILL INCREASE THE CHANCE FOR LOCALLY HEAVY
DOWNPOURS. THE HIGHEST CHANCE FOR POTENTIALLY SIGNIFICANT HEAVY
RAINFALL WILL BE ALONG THE BOUNDARY AHEAD OF AN UPPER-LEVEL WAVE
OVER PORTIONS OF THE UPPER GREAT LAKES/UPPER MISSISSIPPI VALLEY
SATURDAY. ONGOING ORGANIZED STORMS FROM OVERNIGHT FRIDAY AS WELL
AS THE RISK FOR MORE WIDESPREAD, ORGANIZED STORMS AHEAD OF AN
UPPER-LEVEL WAVE INTO THE DAY SATURDAY HAS PROMPTED A MODERATE
RISK OF EXCESSIVE RAINFALL (LEVEL 3/4) OVER SOUTHERN WISCONSIN AND
NORTHEASTERN IOWA FOR THE THREAT OF SCATTERED TO NUMEROUS
INSTANCES OF FLASH FLOODING. A BROADER SLIGHT RISK (LEVEL 2/4)
COVERS THE REGION. IN ADDITION, A FEW STORMS MAY BE SEVERE, WITH A
SLIGHT RISK OF SEVERE WEATHER (LEVEL 2/5) ISSUED BY THE STORM
PREDICTION CENTER FOR THE THREAT OF SOME DAMAGING WINDS AND A FEW
TORNADOES. A LOCALLY HIGHER THREAT FOR HEAVIER DOWNPOURS WILL ALSO
EXIST OVER SOUTHERN NEW ENGLAND, WITH A SLIGHT RISK IN PLACE. THE
NOTED MORE POTENT UPPER-LEVEL SHORTWAVE ARRIVING SUNDAY WILL HELP
TO PUSH THE BOUNDARY SOUTH AND EASTWARD, BRINGING HIGHER STORM
CHANCES MORE BROADLY ACROSS NEW ENGLAND AND SOUTHWESTWARD THOUGH
THE MID-ATLANTIC/OHIO VALLEY/TENNESSEE VALLEY. STRONGER, VERY
MOIST LOW-LEVEL FLOW INTERACTING WITH THE BOUNDARY OVER NORTHERN
NEW ENGLAND WILL BRING THE GREATEST THREAT FOR HEAVY DOWNPOURS AND
SCATTERED FLASH FLOODING, WITH ANOTHER SLIGHT RISK IN PLACE. A
SLIGHT RISK FOR SEVERE WEATHER ALSO COVERS MUCH OF THE SAME REGION
AND SOUTHWESTWARD INTO THE NORTHERN APPALACHIANS/UPPER OHIO
VALLEY, WHERE DAMAGING WINDS AND A FEW TORNADOES WILL ONCE AGAIN
BE THE MAIN THREATS.
UPPER-LEVEL RIDGING WILL BEGIN TO BUILD OVER THE WESTERN AND THEN
CENTRAL U.S. FOLLOWING THE SHORTWAVE PASSAGE, BRINGING RISING
TEMPERATURES ACROSS THIS REGION AS WELL. FORECAST HIGHS SATURDAY
ACROSS MUCH OF THE INTERIOR PACIFIC NORTHWEST, GREAT BASIN, AND
CALIFORNIA WILL BE IN THE MID-90S TO LOW 100S. LOCALLY HIGHER
TEMPERATURES INTO THE MID-100S HAVE PROMPTED HEAT-RELATED
ADVISORIES AND WARNINGS FOR THE CENTRAL CALIFORNIA VALLEYS INTO
PORTIONS OF SOUTHERN CALIFORNIA. THE FOCUS OVER THE NORTHERN TIER
WILL BEGIN TO SHIFT EASTWARD WITH THE RIDGE ON SUNDAY, WITH COOLER
HIGHS IN THE PACIFIC NORTHWEST BUT TEMPERATURES SOARING INTO THE
MID- AND UPPER 90S OVER MUCH OF THE CENTRAL/NORTHERN HIGH PLAINS.
CONDITIONS WILL REMAIN HOT FROM CENTRAL TO SOUTHERN CALIFORNIA.
WHILE TEMPERATURES WILL STILL BE HOT, TEMPERATURES WON'T BE QUITE
AS ABOVE NORMAL FOR THE DESERT SOUTHWEST AS MONSOON-LIKE
CONDITIONS REMAIN OVER THE REGION. HIGHS SATURDAY AND SUNDAY WILL
RANGE IN THE MID- TO UPPER 100S, WITH SCATTERED SHOWERS AND STORMS
BRINGING THE THREAT FOR SOME LOCALLY HEAVY DOWNPOURS AND AN
ISOLATED RISK FOR FLASH FLOODING. ELSEWHERE, A PAIR OF WAVES OF
LOW PRESSURE PASSING OVER PORTIONS OF THE SOUTHEAST/FLORIDA AS
WELL AS SOUTH TEXAS WILL BRING DAILY SHOWER AND STORM CHANCES.
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