SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 PM CDT Tue Mar 18 2025 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST KANSAS TO FAR EASTERN IOWA... ...SUMMARY... Isolated, marginally severe hail is possible by late tonight in a corridor from north central Kansas through central Iowa. ...Discussion... 00Z Surface analysis shows a 989mb surface low in west-central Kansas this evening. Ahead of this surface low, a low-level jet is strengthening (now 50 kts below 1km on the KICT VWP). This low-level jet is forecast to strengthen to 65 to 70 knots by 06Z which will be crucial for low-level moistening and thunderstorm potential later tonight. The 00Z RAOB from TOP showed a very dry profile. However, slightly better moisture is in place across central Oklahoma with a 8C dewpoint at 850mb at OUN. Forecast guidance continues to indicate that enough of this moisture will advect north into warm frontal zone across northeast Kansas and Iowa for weak to moderate instability by 08-10Z. If sufficient moistening occurs for 1000 J/kg MUCAPE early Wednesday morning, supercells capable of large hail will be possible given 40-45 knots of effective shear. Expanded the marginal slightly east this outlook to account for latest HRRR placement of the strongest storms early Wednesday morning. ..Bentley.. 03/19/2025