Valid 2026-10-13 12:00 UTC – 2026-10-18 12:00 UTC

DISCUSSION

The 00Z models have slowed the progression of an upper low and associated trough from the Great Basin into the central Rockies on Days 4 and 5/Tuesday and Wednesday. By Day 6/Thursday and beyond, model spread increases in the handling of that midlevel system, leading to greater uncertainty in the evolution of the large-scale pattern.

Day 4/Tuesday

There is some model signal that a subtle disturbance embedded within a belt of enhanced mid/upper-level flow will progress from the southern Rockies into the central High Plains, aiding in the deepening of a lee cyclone over southeast CO. Elsewhere, a low-amplitude disturbance is forecast to advance from the Great Lakes into the Northeast, in tandem with another surface low. A frontal system will connect the two lows, stretching from the lower Great Lakes through the OH Valley into the central Plains. A dryline will extend south from the lee cyclone to along the TX-NM border. A moist and unstable air mass will reside south of the front, especially over the central and southern Plains, where richer boundary-layer moisture is expected to reside.

Isolated severe storms appear possible along the front Tuesday afternoon and evening, especially in the Northeast, and from the lower-MO Valley into the central and southern Plains. The most probable location for organized severe storm potential is over the southern High Plains in the vicinity of the lee cyclone and strengthening low-level jet where stronger forcing for ascent and vertical shear will coincide with a moderately unstable air mass.

Day 5/Wednesday

The slowing of the upper-air system and the potential for thunderstorms Tuesday night into Wednesday morning lead to greater uncertainty in where the strongest instability will develop by afternoon. Isolated severe storms appear possible along and south of a surface front from the southern Mid-Atlantic into the central and southern Plains. However, confidence in delineating an area of more concentrated severe weather potential has diminished. And as such, the previously included 15% contour will be removed for this forecast update.

Days 6 through 8/Thursday through Saturday

As alluded to above, spread increases across the models (especially the deterministic solutions) in the handling of the central Rockies low/trough. However, the general signal is for a trend toward a less-favorable synoptic pattern for severe storms by next weekend.

Mead · 10/10/2026