809
ACUS48 KWNS 030830
SWOD48
SPC AC 030829
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0329 AM CDT MON AUG 03 2026
VALID 061200Z - 111200Z
..DISCUSSION
..DAY 4/THURSDAY
BROAD TROUGHING IS FORECAST FROM THE NORTHERN PLAINS THROUGH THE
GREAT LAKES WITH A SERIES OF DISTURBANCES MOVING THROUGH THAT
AIRFLOW PATTERN. ELSEWHERE, AN ELONGATED VORTICITY RIBBON WILL
PROGRESS FROM THE CENTRAL AND SOUTHERN APPALACHIANS INTO THE
NORTHEAST. AT THE SURFACE, A FRONT INITIALLY FROM THE SOUTHERN GREAT
LAKES INTO THE SOUTHERN PLAINS IS FORECAST TO WEAKEN. OVER THE
EASTERN CONUS, SOUTHERLY WINDS WILL MAINTAIN A BROAD CORRIDOR OF 70+
F DEWPOINTS ALONG AND EAST OF THE APPALACHIANS, WHICH WILL
CONTRIBUTE TO MODERATE INSTABILITY BY AFTERNOON. AIDED BY THE
APPROACH OF THE DISTURBANCE ALOFT, THUNDERSTORMS ARE EXPECTED TO
INCREASE IN COVERAGE THROUGH THE AFTERNOON WITH SOME SEVERE WEATHER
POSSIBLE. GENERALLY WEAK VERTICAL SHEAR AND THE ABSENCE OF A
COHERENT FRONT IN THE REGION LEAD TO UNCERTAINTY IN WHERE THE
GREATEST THREAT MAY MATERIALIZE.
AN ISOLATED SEVERE THREAT MAY ALSO DEVELOP ALONG THE FRONT FROM THE
OZARK PLATEAU INTO THE SOUTHERN HIGH PLAINS, AND IN AZ DURING THE
AFTERNOON AND EVENING.
..DAY 5/FRIDAY
AN INTENSE MID/UPPER-LEVEL LOW IS EXPECTED TO EVOLVE OVER CENTRAL
CANADA WITH UPPER HIGHS SITUATED OVER THE GREAT BASIN AND OFF THE
MID-ATLANTIC COAST. BETWEEN THOSE FEATURES, CORRIDORS OF STRONGER
MID-LEVEL FLOW ARE FORECAST FROM THE NORTHERN ROCKIES INTO THE
NORTHERN PLAINS, AND TO A LESSER EXTENT OVER THE NORTHEAST.
SOME SEVERE WEATHER THREAT MAY AGAIN MATERIALIZE FROM THE
MID-ATLANTIC INTO SOUTHERN NEW ENGLAND IN THE VICINITY OF A SURFACE
TROUGH. HOWEVER, THE STRONGEST VERTICAL SHEAR IS FORECAST TO BE
DISPLACED TO THE NORTH OF THE STRONGER INSTABILITY, LEADING TO
UNCERTAINTY IN THE EXTENT OF THE SEVERE WEATHER THREAT. ISOLATED
SEVERE STORMS ALSO APPEAR POSSIBLE ALONG A FRONT MOVING INTO THE
UPPER MS VALLEY.
..DAYS 6-8/SATURDAY THROUGH MONDAY
THE VARIOUS 00Z ENSEMBLE MEANS INDICATE AN UPPER LOW INITIALLY OVER
HUDSON BAY SHIFTING EAST INTO NORTHERN QC WITH PERSISTENT RIDGING
OVER THE SOUTHERN CONUS. BETWEEN THOSE FEATURES, A BELT OF ENHANCED
MID-LEVEL FLOW IS FORECAST ACROSS THE NORTHERN TIER OF STATES WITH
SOME SIGNAL FOR CONTINUED TROUGHING THROUGH SUNDAY OVER THE GREAT
LAKES INTO THE OH VALLEY. AT THE SURFACE, THERE IS ENSEMBLE MEMBER
CLUSTERING IN SURFACE LOW POSITIONS OVER THE NORTHERN PLAINS ALONG A
FRONT EXTENDING INTO THE UPPER GREAT LAKES. THERE IS A MODEL SIGNAL
FOR THE FRONT TO CONTINUE INTO THE GREAT LAKES AND MIDWEST, WHERE
SOME SEVERE WEATHER THREAT APPEARS POSSIBLE. A SEPARATE SEVERE
WEATHER RISK MAY ALSO PERSIST FROM THE MID-ATLANTIC INTO NEW
ENGLAND.
..MEAD.. 08/03/2026
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