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MD 0850 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN MISSISSIPPI
Mesoscale Discussion 0850 NWS Storm Prediction Center Norman OK 0235 AM CDT Sun May 18 2025 Areas affected...northern Mississippi Concerning...Severe potential...Watch unlikely Valid 180735Z - 180830Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms will continue moving east across Mississippi this morning. Large hail and damaging winds will be possible with the strongest cores, but the overall threat should remain sparse enough to preclude the need for a watch. DISCUSSION...A cluster of thunderstorms moving east out of Arkansas appears to have developed small mesoscale convective vortex. This MCV appears to be aiding thunderstorm development on its southern flank, where MUCAPE is between 2000-3000 J/kg. Given this thermodynamic environment and effective-layer shear around 50 knots, episodic updraft pulses may support isolated large hail or wind damage. However, widespread severe reports are not anticipated. ..Marsh/Smith.. 05/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MEG...JAN... LAT...LON 33819083 34218985 33978835 33088837 33349085 33819083 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun May 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY...OHIO VALLEY...AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are likely across portions of the Ohio Valley, Mid-Mississippi Valley, and Tennessee Valley on Monday. ...Synopsis... A mid-level low will stall and perhaps start to retrograde across parts of the Upper Midwest on Monday. A surface low in the MO/IL region will start to occlude during the day. A cold front will move east through the period with a warm front across the Ohio Valley. ...Mid-Mississippi Valley into the Ohio Valley and Tennessee Valley... Thunderstorms will likely be ongoing amid broad isentropic ascent and moderate elevated instability along the warm front in southern Illinois and Indiana and vicinity on Monday morning. South of this morning activity, where upper 60s to low 70s dewpoints are anticipated, moderate to strong instability is forecast to develop amid daytime heating. As 55 to 65 knots of mid-level flow overspreads the warm sector, strong shear will be present for supercells. Large to very large hail will be the primary threat initially, as low-level flow will likely be veered. However, low-level shear should be strong enough to support some tornado threat during the afternoon/evening. As storms grow upscale, one or more bowing segments may develop with an increased damaging wind threat during the evening and perhaps persisting into the overnight period. ..Bentley.. 05/18/2025 Read more

MD 0849 CONCERNING SEVERE THUNDERSTORM WATCH 283... FOR OKLAHOMA
Mesoscale Discussion 0849 NWS Storm Prediction Center Norman OK 1130 PM CDT Sat May 17 2025 Areas affected...Oklahoma Concerning...Severe Thunderstorm Watch 283... Valid 180430Z - 180630Z The severe weather threat for Severe Thunderstorm Watch 283 continues. SUMMARY...A severe threat will likely continue across much of Oklahoma for several more hours. Very large hail, wind damage and an isolated tornado threat will be possible. DISCUSSION...The latest hi-resolution radar data from KTLX shows three areas of somewhat widely spaced severe storms. The most intense convection is located in western Oklahoma, along the eastern edge of a bullseye of moderate instability. The RAP has MLCAPE estimated in the 2000 to 3500 J/kg range, which appears to be related to a localized maximum in surface dewpoints. The storms are being supported by increasing low-level warm advection and to subtle perturbations within within west-southwesterly flow. The storms will continue to move eastward across central and eastern Oklahoma during the early overnight period. Regional WSR-88D VWPs at Oklahoma City and Tulsa have 0-6 km shear of 52 kt and 42 kt, respectively. The RAP is showing mid-level lapse rates above 8 C/km across much of central Oklahoma. This will support supercells with large hail. The most intense storms could also produce hailstones greater than 2 inches in diameter. An isolated wind-damage and tornado threat may also accompany the stronger storms. ..Broyles.. 05/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA...OUN... LAT...LON 34579644 34599806 34869881 35709901 36369836 36299590 35559537 34849571 34579644 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more