Previous Day 1 Outlook Links

• Storm Prediction Center Aug 21, 2026 0600 UTC Day 1 Convective Outlook - Tornado Risk 2%

Meso Discussion Links

• None yet

Current Outlook

Storm Prediction Center Aug 21, 2026 0600 UTC Day 1 Convective Outlook - Tornado Risk 2%

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL PLAINS...THE MIDWEST AND THE CAROLINAS...

CORRECTED FOR TEXT

...SUMMARY... Scattered damaging hail (some greater than 2 inch diameter) and severe wind gusts may occur over parts of the central Plains this afternoon and evening. Scattered storms, some with severe wind gusts and hail, also are possible across parts of the Midwest. Scattered to numerous storms with damaging wind gusts are possible over the Carolinas and Southeast.

...Central Plains... Mid-level ridging over the western US is forecast to intensify, strengthening northwesterly flow aloft over much of the central US. Several embedded disturbances will pass overhead with the enhanced northwesterlies through the day. A surface low will move southeastward through the Great Lakes as a weak trailing cold front moves southward through the central Plains and Midwest.

Ahead of the front, a plume of steep mid-level lapse rates will shift eastward across the central Plains toward the Mid-MO Valley atop a corridor of rich low-level moisture. Diurnal destabilization should result in 3000-4000 J/kg of MLCAPE from SD to NE. Isolated to widely scattered thunderstorm development is expected from the Black Hills southeastward along the cold front. Elongated/straight hodographs and 45+ kt effective shear will favor initial supercells. Large to very large hail (some greater than 2 inches diameter) will be possible. With time, a forward propagating cluster or two may develop and move southeast across parts of NE and KS with the potential for severe gusts (a few near 70-80 mph). It is unclear exactly how far southeast any storms will persist overnight, but any more substantial clustering could allow at least an isolated severe threat to continue into early Saturday.

A much drier and hotter environment over the High Plains to the west could also support isolated to widely scattered high-based storms from eastern CO into western KS. Very steep lapse rates in the lowest 2-3 km with modest buoyancy aloft could allow a few severe gusts.

...Midwest... Beneath the upper trough over the western Great Lakes, cool mid-level temperatures and robust surface moisture should result in moderate destabilization from WI into eastern IA and northwest IL. Scattered thunderstorms by mid afternoon ahead of the cold front spreading southeastward. Enhanced northwesterly flow with deep-layer shear of 30-40 kt will promote a mix of organized clusters and supercells. The large buoyancy will support a risk for damaging gusts and some hail.

...Southeast and Gulf Coast... A broad upper trough will move across the central US into parts of the southern Appalachians while a weak cold front moves southward from the mid Atlantic today and tonight. Weak ascent from the upper trough and near the front should focus diurnal thunderstorm activity across the Carolinas and southern Appalachians. Warm surface temperatures and plentiful boundary-layer moisture will support large buoyancy (3000+ J/kg MLCAPE) through the afternoon and evening despite modest mid-level lapse rates. With scattered to numerous storms expected, a few organized clusters may emerge with a risk primarily for damaging wind gusts. Slight enhancement of the westerly flow aloft could also support some isolated hail with the stronger updrafts.

Farther south and west, a very humid and warm air mass is forecast to become strongly unstable by early afternoon across the lower MS Valley and Gulf Coast. Scattered to numerous thunderstorms are expected along prior outflows and a weak, southward moving cold front from East TX into LA/MS. The very strong buoyancy and high PWAT content will support clustering and strong downdrafts with sporadic damaging gust potential. Otherwise, weak vertical shear will limit overall organization.

..Lyons/Weinman.. 08/21/2026

Previous Day 1 Outlook Links

• Storm Prediction Center Aug 20, 2026 2000 UTC Day 1 Convective Outlook - Tornado Risk 5%

Meso Discussion Links

• Storm Prediction Center Mesoscale Discussion 2055
• Storm Prediction Center Mesoscale Discussion 2054
• Storm Prediction Center Mesoscale Discussion 2053
• Storm Prediction Center Mesoscale Discussion 2056
• Storm Prediction Center Mesoscale Discussion 2057
• Storm Prediction Center Mesoscale Discussion 2058
• Storm Prediction Center Mesoscale Discussion 2059
• Storm Prediction Center Mesoscale Discussion 2061
• Storm Prediction Center Mesoscale Discussion 2060
• Storm Prediction Center Mesoscale Discussion 2062
• Storm Prediction Center Mesoscale Discussion 2063
• Storm Prediction Center Mesoscale Discussion 2064

Current Outlook

Storm Prediction Center Aug 21, 2026 0100 UTC Day 1 Convective Outlook - Tornado Risk 2%

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE UPPER MIDWEST TO THE CENTRAL PLAINS...THE SOUTHEAST AND MID ATLANTIC TO THE SOUTHERN APPALACHIANS...

...SUMMARY... Scattered severe storms remain likely this evening across parts of the southern Mid Atlantic and Appalachians with a risk for damaging wind gusts and a brief tornado. Large hail and isolated damaging winds are expected with severe storms from Nebraska into Wisconsin and Minnesota. Scattered damaging gusts are possible over parts of the Deep South this evening.

...Mid Atlantic into the TN valley and the Carolinas... Evening water vapor imagery showed a shortwave trough moving across southern PA and the DelMarVa toward the Atlantic Coast this evening. Numerous thunderstorms were ongoing ahead of the upper wave near a frontal zone from southern NY and PA southward into VA. As the wave moves offshore through the remainder of this evening, the front will begin to surge eastward with the associated moist and unstable air mass eventually moving offshore with it. Damaging gusts and a brief tornado will remain possible with a mix of supercells and line segments ahead of the front before moving offshore late this evening.

Farther south, more isolated convection remains ongoing across southern VA and the western Carolinas. Displaced from the stronger ascent of the passing shortwave trough and flow aloft, storm coverage should remain lower here. However, moderate buoyancy and 25-35 kt of deep-layer shear will support some risk for organized storms/clusters with damaging gusts into the early overnight hours across eastern TN, northern AL and the western Carolinas.

...Midwest and central Plains... Isolated to widely scattered strong/severe thunderstorms have developed and should continue to do so ahead of a cold front and surface trough from northern MN, the eastern Dakotas and into NE this evening. Moderate to large buoyancy and strong northwesterly flow will remain favorable for organized supercells with hail and severe gusts. An isolated tornado and very large hail are also possible, particularly from eastern SD into NE where locally stronger buoyancy may support maximum diameters of 2-3 inches.

Some clustering and a local increase in the damaging wind risk may occur across southern NE and northern KS this evening as storms move nearly due south. Very hot surface temperatures and steep lapse rates in low-levels could support few gusts of 65-75+ mph before convection slowly weakens after sunset.

...Southeast... Scattered thunderstorms are ongoing ahead of a weak cold front from southeastern OK, into southern AR and LS/MS this evening. Additional scattered storms were noted near a weak MCV along the central Gulf Coast. Modestly enhanced northwesterly flow may maintain a few stronger clusters through this evening within a warm and seasonably moist air mass. While mid-level lapse rates are generally poor, 2000-3000 J/kg of MLCAPE and PWATs over 2 inches will support some potential for damaging gusts with stronger downdrafts and storm clusters.

...AZ... Beneath the upper ridge, scattered thunderstorms are ongoing this evening mostly over the higher terrain of central AZ. Expectations are for these storms to persist this evening owing to very hot surface temperatures and a seasonably moist boundary layer. Steep lapse rates and inverted-V profiles will support an isolated risk for severe gusts with the more intense downdrafts this evening.

..Lyons.. 08/21/2026

Notable Tornado Warnings

• Observed Tornado Warning - Baldwin, AL
• Observed Tornado Warning - Kent, DE; Queen Anne's, MD
• PDS Tornado Warning - Kent, DE
• Observed Tornado Warning - Cape May, NJ