ACUS02 KWNS 210601

SWODY2

SPC AC 210559



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1259 AM CDT Sun Jun 21 2026



Valid 221200Z - 231200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF

THE CAROLINAS INTO THE MID-ATLANTIC AND FOR THE CENTRAL/NORTHERN

HIGH PLAINS....



...SUMMARY...

Scattered severe storms appear possible across portions of the

Mid-Atlantic Monday afternoon and evening. More isolated severe

weather is expected along a frontal zone that will extend from the

southern Appalachians to the Mid-South and southern Plains.

Additionally, a widely scattered severe weather threat is expected

across the central and northern High Plains Monday afternoon and

evening.



...Synopsis...

Mostly zonal flow is expected across the CONUS on Monday with

multiple embedded shortwave troughs within the flow pattern from the

central Plains to the Mid-Atlantic. A weak surface low is expected

to movefrom the Appalachians to the Mid-Atlantic, associated with

the strongest of the mid-level jet streaks within the broader flow.

An additional lee cyclone is expected to develop along the southern

High Plains during the period with a surface front connecting these

two features. 



...Mid-Atlantic...

Moderate instability is forecast to develop east of the Appalachians

from the Carolinas into the Mid-Atlantic on Monday beneath up to 50

knots of mid-level flow. This combination of shear and instability

will support storm organization, including the potential for some

supercells. Neutral to potentially weak height rises may limit storm

coverage across the region, which may preclude a more widespread

severe wind threat. However, given the steep low-level lapse rates

where temperatures are forecast to warm into the mid 90s, damaging

winds will be likely from any storms that develop. 



A narrow zone near the warm front will have a greater tornado threat

given the enhanced shear from a compact, but strong, low-level jet

across northern Virginia into the DelMarVa. A 5% tornado contour may

eventually be needed within this zone, but given the relatively

narrow zone of threat and some uncertainty where this front will be

by Monday afternoon/evening, higher probabilities will not be added

at this time. 



...Central/Northern High Plains...

Weak lee cyclogenesis is forecast across eastern Wyoming during the

day Monday. This will strengthen upslope flow across the

central/northern Plains. Moderate instability and strengthening

west-northwesterly flow aloft of 40 to 45 knots will result in an

environment that supports widely scattered supercells with the

potential for large to very large hail and perhaps some isolated

wind gusts. 



...Northwest Texas and Vicinity...

A more conditional severe weather threat will exist across northwest

Texas and vicinity where there is potential for an outflow boundary

from the morning MCS across Oklahoma to intersect the dryline.

Height rises aloft and strong inhibition should mostly suppress

convection. However, mesoscale convergence at the intersection of

these boundaries could result in one or two supercells capable of

all severe hazards. However, given the conditionality of this

mesoscale threat, higher probabilities have not been added at this

time. 



...Mid-Mississippi Valley...

Moderate to strong destabilization is forecast ahead of and south of

a morning MCS that should be in the Oklahoma/Arkansas region on

Monday morning. Reinvigoration of the ongoing MCS or additional

development may result in some isolated damaging wind threat.

However, overall very weak mid-level lapse rates and weaker shear

where the greatest instability is forecast, should keep the threat

mostly marginal/isolated.



..Bentley.. 06/21/2026



$$