Weather Blog

dont you just "love" snow/sleet

1/31/2026 - Dean Eubanks

❄️ Potential Mid-South / Tennessee Valley Winter Storm

Pattern Overview & Early Signal

Still ~14 days out — details will change — but the large-scale pattern is worth watching.

A developing winter storm signal is emerging across the Mid-South and Tennessee Valley as strong continental high pressure (1026–1030 mb) remains anchored over the Plains and Midwest, supplying a solid cold air source while a deep surface low (~1006 mb) lifts northeast out of Texas toward the Lower Mississippi and Tennessee Valleys. A tight 1000–500 mb thickness gradient with the 540 dam line slicing across Arkansas and Tennessee highlights a classic rain–snow transition zone, where small track shifts could result in significant impact changes. Much of Arkansas, Tennessee, Kentucky, and Missouri appears locked into mid-20s to low-30s surface temperatures with deeper cold to the north, suggesting the cold air is not shallow at this time. Anomalously high February moisture, with precipitable water values of 1.5–2.0+ inches surging north from the Gulf, supports the potential for higher QPF and sustained precipitation. Aloft, a strong southern-stream jet, broad central U.S. troughing, and favorable diffluence over the Lower Mississippi and Tennessee Valleys promote cyclogenesis, while multiple embedded vorticity maxima support prolonged lift rather than a quick-hitting system. A well-defined 850-mb frontogenesis signal from Texas through Arkansas into Tennessee further raises the potential for mesoscale banding and heavier snowfall rates. Overall, pattern confidence is medium-high, location confidence remains low to medium due to expected track shifts, and impact potential is high if this general setup holds.

1. Synoptic Setup (Surface + Thickness)

Strong continental high pressure (1026–1030 mb) anchored over the Plains/Midwest → solid cold air supply.
A deep surface low (~1006 mb) over Texas, lifting NE toward the Lower Mississippi/Tennessee Valley.
Tight 1000–500 mb thickness gradient, with 540 dam slicing across AR/TN → classic rain/snow line indicator.
Snow shield north of the surface low, rain/thunder south — textbook.

👉 This is the kind of setup where small track shifts = big impacts.

2. Temperature Field (2 m AGL)

Much of AR/TN/KY/MO sitting in the mid-20s to low-30s°F.
Deep cold locked in to the north (single digits / teens).
Gulf Coast well into the 50s–70s, ensuring strong thermal contrast.

👉 Cold air is not shallow — that matters. This is not a warm-nose-dominated look.

3. Moisture (Precipitable Water)

PW values 1.5–2.0+ inches surging north from the Gulf.
For February, that’s anomalously high moisture feeding directly into subfreezing air.

👉 Translation: high QPF potential, not a dry, nuisance event.

4. Upper-Level Pattern (500 mb Heights & Wind)

Strong southern stream jet (90–120 kt) screaming from TX → Southeast.
Broad troughing across the central U.S., with downstream ridging off the East Coast.
Excellent diffluence aloft over the Lower Mississippi & Tennessee Valleys.

👉 This favors strong cyclogenesis and sustained precipitation, not a quick hitter.

5. Vorticity (500 mb)

Multiple embedded vorticity maxima ejecting out of the Southwest.
One dominant vort lifting NE, with additional energy behind it → prolonged lift.
East Coast also shows a deep system, helping lock the pattern.

👉 This supports long-duration precip, not a single band.

6. Frontogenesis (850 mb)

Clear, well-defined FGEN banding from TX → AR → TN.
Thermal gradient tightens right over the cold dome.
This is where mesoscale banding and heavier rates live.

👉 If this verifies, snowfall could come in bands, not evenly spread.

Page updated

Google Sites

Report abuse