650
FXUS01 KWBC 042001
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 PM EDT FRI APR 04 2025
VALID 00Z SAT APR 05 2025 - 00Z MON APR 07 2025
...LIFE-THREATENING, CATASTROPHIC, AND POTENTIALLY HISTORIC FLASH
FLOOD EVENT CONTINUES ACROSS THE LOWER OHIO VALLEY AND MID-SOUTH
TO LOWER MISSISSIPPI VALLEY...
...ADDITIONAL EPISODES OF SIGNIFICANT SEVERE WEATHER EXPECTED FROM
THE SOUTHERN PLAINS TO THE OHIO VALLEY...
...MODERATE TO LOCALLY HEAVY SNOW SHOWERS EXPECTED FOR THE
CENTRAL/SOUTHERN ROCKIES THROUGH SATURDAY...
...WELL ABOVE AVERAGE WARMTH IN THE EAST; CHILLY TEMPERATURES IN
THE CENTRAL U.S....
SEVERAL DEVELOPING WAVES OF LOW PRESSURE ACTING ON A STALLING
FRONTAL BOUNDARY WILL CONTINUE TO BE THE FOCUS FOR THE THREAT OF
LIFE-THREATENING FLASH FLOODING AND SIGNIFICANT SEVERE WEATHER
FROM THE OHIO VALLEY WEST-SOUTHWEST THROUGH THE MIDDLE/LOWER
MISSISSIPPI VALLEY, MID-SOUTH, AND ARKLATEX THROUGH SATURDAY. DEEP
MOISTURE POOLING ALONG THE FRONT COMBINED WITH IMPRESSIVE DYNAMICS
WILL SET THE STAGE FOR PERSISTENT ROUNDS OF INTENSE THUNDERSTORMS
CAPABLE OF PRODUCING TORRENTIAL DOWNPOURS THROUGHOUT THE REGION.
THIS WILL ESPECIALLY BE THE CASE FOR THE LOWER OHIO VALLEY INTO
THE MID-SOUTH AND LOWER MISSISSIPPI VALLEY, WHERE THE NECESSARY
INGREDIENTS OF MOISTURE, INSTABILITY, FORCING, AND WIND SHEAR BEST
OVERLAP. STORM INITIATION AND MOVEMENT ROUGHLY PARALLEL TO THE
BOUNDARY WILL LEAD TO REPEATED ROUNDS OF HEAVY RAINFALL OVER THE
SAME AREAS, LEADING TO SIGNIFICANT TO EXTREME, POTENTIALLY
HISTORIC, RAINFALL TOTALS OVER INCREASINGLY SATURATED SOILS. HIGH
RISKS (AT LEAST 70%) OF EXCESSIVE RAINFALL REMAIN IN EFFECT
THROUGH SATURDAY, HIGHLIGHTING AN INCREASINGLY DANGEROUS AND
LIFE-THREATENING SITUATION. OUTSIDE OF THE HIGH RISK, MODERATE AND
SLIGHT RISKS ALSO CONTINUE TO BE IN PLACE OVER BROADER AREAS OF
THE OHIO VALLEY INTO THE SOUTH-CENTRAL U.S. THROUGH SATURDAY WHERE
SCATTERED TO NUMEROUS INSTANCES OF FLASH FLOODING CAN BE EXPECTED.
AS HAS BEEN SAID REPEATEDLY FOR THE LAST SEVERAL DAYS, THIS HAS
THE MAKINGS OF A CATASTROPHIC, POTENTIALLY HISTORIC HEAVY RAINFALL
AND FLASH FLOOD EVENT, WITH SOME LOCATIONS POTENTIALLY SEEING
RAINFALL AMOUNTS AS HIGH AS 10-15"+ THROUGH THE WEEKEND. THE
REPEATING ROUNDS OF HEAVY RAINFALL EACH DAY WILL ALSO RAISE THE
RISK OF WIDESPREAD SIGNIFICANT RIVER FLOODING, INCLUDING
POTENTIALLY CATASTROPHIC MAJOR FLOODING, IN THE OZARKS, PORTIONS
OF THE MIDDLE MISSISSIPPI VALLEY, AND MUCH OF THE OHIO VALLEY.
THANKFULLY, THE HEAVIEST RAINFALL SHOULD EASE SOMEWHAT FOR THE
HARDEST HIT AREAS ON SUNDAY AS THE FRONTAL BOUNDARY FINALLY BEGINS
TO PUSH EASTWARD INTO THE SOUTHEAST AND MID-ATLANTIC; HOWEVER,
MAJOR RIVER FLOODING IS LIKELY TO CONTINUE INTO EARLY NEXT WEEK.
WITH THE FRONT ON THE MOVE, THE FOCUS FOR HEAVY RAINFALL SHIFTS
EASTWARD INTO PARTS OF THE CAROLINAS SOUTHWARD TO THE CENTRAL GULF
COAST TO ROUND OUT THE WEEKEND. A SLIGHT RISK (AT LEAST 15%)
REMAINS IN EFFECT AS A RESULT.
IN ADDITION TO THE FLASH FLOOD THREAT, ADDITIONAL BOUTS OF
SIGNIFICANT SEVERE WEATHER WILL ALSO BE IN PLAY FOR MANY OF THE
SAME LOCATIONS THROUGH THE WEEKEND. THE SAME INGREDIENTS OF
MOISTURE, INSTABILITY, FORCING, AND WIND SHEAR THAT ARE CONDUCIVE
TO INTENSE DOWNPOUR PRODUCING THUNDERSTORMS ARE ALSO SUPPORTIVE OF
SUPERCELLS AND SEVERE WEATHER. THE STORM PREDICTION CENTER HAS
ISSUED A MODERATE RISK (LEVEL 4/5) FOR TONIGHT FROM THE ARKLATEX
INTO SOUTHEAST MISSOURI FOR STRONG TORNADOES, VERY LARGE HAIL, AND
DAMAGING WINDS. A BROADER SLIGHT RISK IS IN PLACE FROM TEXAS
THROUGH THE LOWER OHIO VALLEY. ON SATURDAY, SLIGHT TO ENHANCED
RISKS ARE DELINEATED FOR THE LOWER MISSISSIPPI VALLEY THROUGH THE
MID-SOUTH AND OHIO VALLEY, WITH SEVERE THUNDERSTORMS CAPABLE OF
PRODUCING STRONG TORNADOES, VERY LARGE HAIL, AND DAMAGING WIND
GUSTS ABOVE 70 MPH. SIMILAR TO THE FLASH FLOOD THREAT, THE SEVERE
WEATHER RISK SHIFTS EASTWARD INTO PARTS OF THE MID-ATLANTIC,
SOUTHEAST, AND SOUTHERN APPALACHIANS ON SUNDAY, WITH THE STORM
PREDICTION CENTER ISSUING A SLIGHT RISK FOR THE POTENTIAL FOR
DAMAGING WINDS AND POSSIBLY A FEW TORNADOES.
FARTHER WEST, A PASSING COLD FRONT WILL HELP SUPPORT SNOW SHOWERS
OVER THE ROCKIES AS WELL AS PORTIONS OF THE HIGH PLAINS THROUGH
SATURDAY. ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT. TO THE
SOUTH, AN AREA OF LOW PRESSURE IN THE LEE OF THE ROCKIES WILL HELP
TO FOCUS UPSLOPE FLOW ALONG THE MOUNTAINS, RESULTING IN MODERATE
TO LOCALLY HEAVY SNOWS FOR THE REGIONAL MOUNTAIN RANGES ON THROUGH
THIS EVENING, WITH THE POTENTIAL FOR SOME SNOW FOR PORTIONS OF THE
HIGH PLAINS ALONG THE FRONT RANGE. THE COLD FRONT TO THE NORTH
WILL ALSO PASS SOUTHWARD BY LATE TONIGHT AND INTO THE DAY
SATURDAY, BRINGING RENEWED POST-FRONTAL UPSLOPE FLOW AND
ADDITIONAL HEAVY SNOW FOR THE MOUNTAINS OF THE FRONT RANGE. THERE
IS ALSO AN INCREASING POTENTIAL FOR ACCUMULATING SNOW TO SPREAD
ACROSS PORTIONS OF NEW MEXICO AND INTO THE SOUTHERN HIGH PLAINS
INTO SATURDAY. DRIER WEATHER RETURNS ON SUNDAY AS HIGH PRESSURE
SETTLES OVER THE CENTRAL U.S..
THE HIGHLY AMPLIFIED FLOW PATTERN WILL LEAD TO WELL ABOVE AVERAGE
TEMPERATURES ACROSS THE SOUTHEAST AS AN UPPER-LEVEL RIDGE
DOMINATES THE REGION. MEANWHILE, TEMPERATURES WILL REMAIN MUCH
COOLER AND BELOW AVERAGE UNDER THE UPPER-LEVEL TROUGH OVER MOST OF
THE WESTERN/CENTRAL U.S. HIGHS THE NEXT COUPLE DAYS ACROSS THE
SOUTHEAST ARE FORECAST TO BE IN THE 80S TO LOW 90S, WITH NUMEROUS
RECORD-TYING/BREAKING HIGHS POSSIBLE. FARTHER NORTH, A COOL
SURFACE HIGH WILL TAKE HOLD IN THE NORTHEAST SATURDAY WITH BELOW
NORMAL HIGHS IN THE 40S. SOME WINTRY WEATHER CAN'T BE RULED OUT
ACROSS NORTHERN NEW ENGLAND ON SUNDAY EITHER GIVEN PERSISTENTLY
COOL TEMPERATURES ON THE NORTH SIDE OF THE FRONT. MEANWHILE,
FORECAST HIGHS ACROSS THE PLAINS INTO THE INTERIOR WEST WILL BE
MOSTLY WELL BELOW AVERAGE. SOUTHERN ROCKIES/HIGH PLAINS CAN EXPECT
HIGHS THAT ARE BELOW AVERAGE BY 20-25 DEGREES BY SATURDAY WITH
ACTUAL HIGHS FALLING INTO THE 40S. THE WEST COAST CAN EXPECT
WARMER, ABOVE AVERAGE TEMPERATURES COMPARED TO THE REST OF THE
WEST AS A RIDGE BUILDS NORTHWARD OVER THE REGION, WITH HIGHS IN
THE 60S AND 70S THE WEST WILL CONTINUE TO WARM UP ON SUNDAY WHILE
COOLER AIR ACROSS THE PLAINS SPREADS EASTWARD INTO THE OHIO
VALLEY, THE MID-SOUTH, AND THE LOWER MISSISSIPPI VALLEY.
KEBEDE/MILLER
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