SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 PM CDT Wed Jun 25 2025 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE SOUTHERN PLAINS TO THE GREAT LAKES...FROM THE MID-ATLANTIC TO THE SOUTHEAST...AND INTO FLORIDA...AND ACROSS NORTHERN MONTANA... ...SUMMARY... Scattered strong storms are possible from the central Plains to Lower Michigan, over parts of the Southeast, and over parts of Montana on Thursday. Scattered damaging gusts appears to be the main concern. ...Synopsis... A weak upper low will remain over Florida tomorrow, with relatively cool midlevel temperatures over the Southeast, although warmer compared to today. Otherwise, much of the east will remain beneath an upper ridge. Around the northern periphery of this ridge, modest southwest flow aloft will stretch from the central Plains into the Great Lakes and Northeast, with relatively warm temperatures aloft. To the west, a low-amplitude upper trough will push east across Montana. At the surface, an expansive area of moisture will persist from the central and southern Plains eastward to the Mid Atlantic, south of a cold front. This front will extend from KS into southern WI and Lower MI, and also from central NY into eastern PA. ...Mid Atlantic to the Southeast... A broad area of moderate to strong instability is forecast from the Mid-Atlantic to the Southeast on Thursday. Shear is expected to be very weak through the period, but moderate to strong instability and relatively steep mid-level lapse rates beneath the upper low will provide a thermodynamic environment favorable for some damaging wind gusts. More focused areas of strong to severe storms may exist near outflow boundaries from D1/Wednesday convection. ...Central/Southern Plains to the Great Lakes... Moderate to strong instability is forecast to develop along a frontal zone from Kansas to Wisconsin on Thursday afternoon/evening. Shear is expected to remain weak (20 to 25 knots), but strong instability will support the threat for some damaging wind gusts. Farther south, across western Oklahoma, shear will be very weak, but moderate instability and deep mixing (to around 600mb) will support some threat for downbursts and isolated wind gusts. ...Montana... Moderate mid-level flow is expected to overspread northern Montana on Thursday where a deeply mixed boundary layer (deeper than 3km) is forecast. While instability should be limited by meager moisture, it should be sufficient for a few storms. Moderate shear (25 to 30 knots) and a deeply mixed boundary layer will support a threat for some severe wind gusts Thursday afternoon/evening. ..Bentley.. 06/25/2025