WW 136 SEVERE TSTM AL AR MS TN 102035Z - 110400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 136 NWS Storm Prediction Center Norman OK 335 PM CDT Thu Apr 10 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern and Central Alabama Far Eastern Arkansas Northern and Central Mississippi Far Southern Middle Tennessee * Effective this Thursday afternoon and evening from 335 PM until 1100 PM CDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail likely with isolated very large hail events to 2 inches in diameter possible SUMMARY...Robust thunderstorms will continue to develop this afternoon and spread southeastward through the evening. Supercells will pose a threat for large hail generally ranging from 1-2 inches in diameter. Scattered severe/damaging winds, with peak gusts up to 65-75 mph, should also occur as clusters form later this afternoon and evening. The severe thunderstorm watch area is approximately along and 70 statute miles north and south of a line from 55 miles north northwest of Greenwood MS to 25 miles northeast of Anniston AL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 135... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 31035. ...Gleason Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Thu Apr 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Scattered strong to severe thunderstorms are expected from portions of the lower Ohio Valley into the Southeast through this afternoon and evening. Large hail and damaging winds should be the main threats. ...20z Update... Ahead of the cold front moving across the OH/MS Valleys, strong heating has promoted gradual destabilization and multiple corridors of storm formation this afternoon. 70s and 80s F surface temperatures indicate the air mass is well-mixed with dewpoints generally in the 40s F. The relatively dry boundary layer should support efficient downward momentum transfer of stronger tropospheric winds, and a threat for scattered damaging winds. Some clustering and a stronger cold pool currently becoming established may focus this threat across the lower OH Valley into parts of TN/KY. Otherwise, isolated damaging gusts and some hail are possible. Across parts of the mid to lower MS valley, predominately cellular storms are expected late this afternoon continuing through the evening. Hail appears likely with these storms given the very favorable lapse rates aloft (8-9 C/km) and elongated hodographs favoring supercells. Some significant hail near 2 inches in diameter cannot be ruled out with the more robust rotating storms. Upscale growth overnight may foster a wind threat as one or more clusters/line segments spread east across AL and GA with damaging gusts. ..Lyons.. 04/10/2025 .PREV DISCUSSION... /ISSUED 1126 AM CDT Thu Apr 10 2025/ ...Lower Ohio Valley into the Southeast... Large-scale upper troughing is forecast to further amplify today over the eastern CONUS, as multiple embedded shortwave troughs rotate through its base. A lead shortwave trough will advance eastward over the upper OH Valley and central Appalachians through the day, while a trailing shortwave trough is expected to move southeastward across the mid MS Valley, lower OH Valley, and TN Valley through this evening. A weak/diffuse cold front is likewise forecast to develop southeastward across these regions through the day, providing some focus for thunderstorm development later this afternoon and evening. 12Z soundings across the Southeast indicate shallow/limited low-level moisture in place, but also relatively steep mid-level lapse rates. Strong daytime heating, gradual low-level moistening from the southwest, and cooling mid-level temperatures associated with the trailing shortwave trough should all aid in the development of around 1000-1500 J/kg of MLCAPE ahead of the front by mid afternoon. Weak low-level westerly winds are forecast to gradually veer and strengthen with height through the mid/upper levels, which will likely foster relatively long/straight hodographs and 40-55+ kt of effective bulk shear. This should easily support organized updrafts, including the potential for supercells. Current expectations are for robust thunderstorm development to occur over the lower OH Valley/Mid-South region by 18-20Z. This initial activity will likely be supercellular, with an associated threat for large hail given steep lapse rates aloft and strong deep-layer shear. Additional strong to severe thunderstorms should develop through the rest of the afternoon and early evening across a larger portion of the lower OH Valley into the TN Valley and Southeast. Any convection which can remain at least semi-discrete should pose a continued hail threat. Some tendency for upscale growth into multiple bowing clusters seems likely by late afternoon/early evening. A well-mixed boundary layer should support efficient downward momentum transfer and a threat for scattered damaging winds, before convection eventually weakens by mid/late evening with the loss of daytime heating. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Thu Apr 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Scattered strong to severe thunderstorms are expected from portions of the lower Ohio Valley into the Southeast through this afternoon and evening. Large hail and damaging winds should be the main threats. ...20z Update... Ahead of the cold front moving across the OH/MS Valleys, strong heating has promoted gradual destabilization and multiple corridors of storm formation this afternoon. 70s and 80s F surface temperatures indicate the air mass is well-mixed with dewpoints generally in the 40s F. The relatively dry boundary layer should support efficient downward momentum transfer of stronger tropospheric winds, and a threat for scattered damaging winds. Some clustering and a stronger cold pool currently becoming established may focus this threat across the lower OH Valley into parts of TN/KY. Otherwise, isolated damaging gusts and some hail are possible. Across parts of the mid to lower MS valley, predominately cellular storms are expected late this afternoon continuing through the evening. Hail appears likely with these storms given the very favorable lapse rates aloft (8-9 C/km) and elongated hodographs favoring supercells. Some significant hail near 2 inches in diameter cannot be ruled out with the more robust rotating storms. Upscale growth overnight may foster a wind threat as one or more clusters/line segments spread east across AL and GA with damaging gusts. ..Lyons.. 04/10/2025 .PREV DISCUSSION... /ISSUED 1126 AM CDT Thu Apr 10 2025/ ...Lower Ohio Valley into the Southeast... Large-scale upper troughing is forecast to further amplify today over the eastern CONUS, as multiple embedded shortwave troughs rotate through its base. A lead shortwave trough will advance eastward over the upper OH Valley and central Appalachians through the day, while a trailing shortwave trough is expected to move southeastward across the mid MS Valley, lower OH Valley, and TN Valley through this evening. A weak/diffuse cold front is likewise forecast to develop southeastward across these regions through the day, providing some focus for thunderstorm development later this afternoon and evening. 12Z soundings across the Southeast indicate shallow/limited low-level moisture in place, but also relatively steep mid-level lapse rates. Strong daytime heating, gradual low-level moistening from the southwest, and cooling mid-level temperatures associated with the trailing shortwave trough should all aid in the development of around 1000-1500 J/kg of MLCAPE ahead of the front by mid afternoon. Weak low-level westerly winds are forecast to gradually veer and strengthen with height through the mid/upper levels, which will likely foster relatively long/straight hodographs and 40-55+ kt of effective bulk shear. This should easily support organized updrafts, including the potential for supercells. Current expectations are for robust thunderstorm development to occur over the lower OH Valley/Mid-South region by 18-20Z. This initial activity will likely be supercellular, with an associated threat for large hail given steep lapse rates aloft and strong deep-layer shear. Additional strong to severe thunderstorms should develop through the rest of the afternoon and early evening across a larger portion of the lower OH Valley into the TN Valley and Southeast. Any convection which can remain at least semi-discrete should pose a continued hail threat. Some tendency for upscale growth into multiple bowing clusters seems likely by late afternoon/early evening. A well-mixed boundary layer should support efficient downward momentum transfer and a threat for scattered damaging winds, before convection eventually weakens by mid/late evening with the loss of daytime heating. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Thu Apr 10 2025 Valid 111200Z - 121200Z Primary adjustment to forecast across the Northern Plains was a southward extension of Elevated highlights into portions of Nebraska. Increasing surface winds are expected from the south in response to Northern Rockies lee troughing development. These winds will overlap sufficiently dry fuels within a well mixed boundary layer, where afternoon relative humidity is expected to drop into 15-20 percent range. This will promote an Elevated fire weather threat Friday for portions of the Dakotas and Nebraska. Otherwise, forecast (see below) remains on track across central Florida for Elevated fire weather conditions. ..Williams/Lyons.. 04/10/2025 .PREV DISCUSSION... /ISSUED 1219 AM CDT Thu Apr 10 2025/ ...Synopsis... A near-stationary mid-level trough will amplify along the East Coast as upper ridging continues to build over the central U.S. and another mid-level trough traverses the Pacific Northwest tomorrow (Friday). Ahead of the approaching Northwest mid-level trough, surface lee troughing will take place across the central and northern High Plains, supporting strong southerly flow in the process. A dry airmass will be transported northward across the northern High Plains, with 15-25 mph sustained southerly winds overlapping with 15-25 percent RH tomorrow afternoon. Elevated highlights have been introduced given dry/windy conditions overlapping at least marginally to modestly dry fuels. Meanwhile, a surface cold front is expected to sweep across the Florida Peninsula tomorrow, with dry/breezy conditions likely in the post-frontal regime. Winds may sustain over 15 mph for at least a few hours during the afternoon, as RH dips as low as 20-30 percent in some areas. Rainfall accumulations have barely exceeded 0.25 inches over the past week for most parts of the central Florida Peninsula, and given the presence of dry fuels, Elevated highlights have been introduced. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Thu Apr 10 2025 Valid 111200Z - 121200Z Primary adjustment to forecast across the Northern Plains was a southward extension of Elevated highlights into portions of Nebraska. Increasing surface winds are expected from the south in response to Northern Rockies lee troughing development. These winds will overlap sufficiently dry fuels within a well mixed boundary layer, where afternoon relative humidity is expected to drop into 15-20 percent range. This will promote an Elevated fire weather threat Friday for portions of the Dakotas and Nebraska. Otherwise, forecast (see below) remains on track across central Florida for Elevated fire weather conditions. ..Williams/Lyons.. 04/10/2025 .PREV DISCUSSION... /ISSUED 1219 AM CDT Thu Apr 10 2025/ ...Synopsis... A near-stationary mid-level trough will amplify along the East Coast as upper ridging continues to build over the central U.S. and another mid-level trough traverses the Pacific Northwest tomorrow (Friday). Ahead of the approaching Northwest mid-level trough, surface lee troughing will take place across the central and northern High Plains, supporting strong southerly flow in the process. A dry airmass will be transported northward across the northern High Plains, with 15-25 mph sustained southerly winds overlapping with 15-25 percent RH tomorrow afternoon. Elevated highlights have been introduced given dry/windy conditions overlapping at least marginally to modestly dry fuels. Meanwhile, a surface cold front is expected to sweep across the Florida Peninsula tomorrow, with dry/breezy conditions likely in the post-frontal regime. Winds may sustain over 15 mph for at least a few hours during the afternoon, as RH dips as low as 20-30 percent in some areas. Rainfall accumulations have barely exceeded 0.25 inches over the past week for most parts of the central Florida Peninsula, and given the presence of dry fuels, Elevated highlights have been introduced. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Thu Apr 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday or Saturday night. ...Central Rockies to the Upper Midwest... A mid-level ridge will deamplify through the day on Saturday as a mid-level shortwave trough progresses out of the northern Rockies into the northern Plains. Large-scale ascent will strengthen near peak diurnal heating across parts of the central Rockies to the Black Hills. With limited buoyancy, isolated/short-lived thunderstorms are anticipated amid scattered high-based/low-topped showers. Where deeply mixed thermodynamic profiles exist in eastern WY and western SD, isolated strong wind gusts are possible. As the low-level jet strengthens across the central Plains on Saturday night, sufficient elevated instability could support some thunderstorms across the Mid-Missouri Valley into the Upper Midwest. Limited moisture/instability should limit any large hail threat from this activity. ..Bentley.. 04/10/2025 Read more

No watches are valid as of Thu Apr 10 17:58:01 UTC 2025.

MD 0440 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR SOUTHEAST MISSOURI INTO PARTS OF KENTUCKY AND TENNESSEE
Mesoscale Discussion 0440 NWS Storm Prediction Center Norman OK 1255 PM CDT Thu Apr 10 2025 Areas affected...far southeast Missouri into parts of Kentucky and Tennessee Concerning...Severe potential...Watch possible Valid 101755Z - 102030Z Probability of Watch Issuance...60 percent SUMMARY...Storms will increase in coverage and intensity through the afternoon, with areas of damaging wind and sporadic hail expected. DISCUSSION...Strong heating continues ahead of a cold front and beneath very cold temperatures aloft with the shortwave trough. An expanding mass of convection is already developing ahead of the frontal surge over southeast MO, and this will develop rapidly southeastward into KY and TN. Very steep lapse rates and moderate deep-layer mean winds should support accelerating cold pools, while straight hodographs and cold temperatures aloft support hail production. ..Jewell/Gleason.. 04/10/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LMK...OHX...HUN...PAH...MEG... LAT...LON 35899043 36359040 37358963 38178912 38218849 38028762 37678624 37498586 37158558 36338578 35508630 35128709 35118828 35589010 35899043 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1207 PM CDT Thu Apr 10 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN CAROLINAS INTO FAR SOUTHEAST VIRGINIA AND FOR NORTHERN FLORIDA AND FAR SOUTHEAST GEORGIA... ...SUMMARY... Isolated strong to locally severe thunderstorms are possible from the eastern Carolinas into southeast Virginia and across far southeast Georgia and northern Florida. ...Eastern Carolinas into Southeast Virginia... A line of showers with embedded thunderstorms is approaching the southern Appalachians by mid-day Thursday along a low-mid-level front which will continue east through the day. Some intensification of these thunderstorms (or additional convective development along the mountains) is expected today which will impact the Friday/Day 2 forecast. As the remnants of this front/mountain convection interact with better low-level moisture across eastern North Carolina later tonight, some intensification of these storms are anticipated. While these storms likely will remain sub-severe without any surface heating and thus minimal instability, the intensification should assist in the remnant outflow boundary/front moving offshore during the morning hours on Friday. This will have a stabilizing effect which results in a conditional severe threat on Day 2/Friday. Some guidance shows a strengthening surface low which results in substantial return flow across the eastern Carolinas, which will result in low 60s dewpoints and weak to moderate instability by later morning to early afternoon. However, if this stronger cyclogenesis does not occur (as forecast by several hi-res models this morning), the instability and severe weather threat will remain mostly offshore. No modifications were made to the marginal risk, but a 2% tornado probability was added for parts of eastern North Carolina. If stronger southerly/southeasterly flow and low 60s dewpoints can develop ahead of a strengthening surface low, a tornado is possible. Overall, a few strong to isolated severe storms are possible with a primary threat of large hail. However, this threat is conditional on destabilization, which remains questionable at this time. ...Southeast Georgia and northern Florida... Strong heating is anticipated along a frontal zone from southeast Georgia to northern Florida Friday afternoon. Forecast soundings show 500 to 750 J/kg MLCAPE with a well-mixed boundary layer extending to near 3km. Overall lack of moisture should limit instability and storm intensity, but 35 to 45 knots of shear will support some storm organization. Therefore, the strongest storms could exhibit some updraft rotation with an increased large hail/severe wind threat, but overall expect the threat to remain isolated. ..Bentley.. 04/10/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1207 PM CDT Thu Apr 10 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN CAROLINAS INTO FAR SOUTHEAST VIRGINIA AND FOR NORTHERN FLORIDA AND FAR SOUTHEAST GEORGIA... ...SUMMARY... Isolated strong to locally severe thunderstorms are possible from the eastern Carolinas into southeast Virginia and across far southeast Georgia and northern Florida. ...Eastern Carolinas into Southeast Virginia... A line of showers with embedded thunderstorms is approaching the southern Appalachians by mid-day Thursday along a low-mid-level front which will continue east through the day. Some intensification of these thunderstorms (or additional convective development along the mountains) is expected today which will impact the Friday/Day 2 forecast. As the remnants of this front/mountain convection interact with better low-level moisture across eastern North Carolina later tonight, some intensification of these storms are anticipated. While these storms likely will remain sub-severe without any surface heating and thus minimal instability, the intensification should assist in the remnant outflow boundary/front moving offshore during the morning hours on Friday. This will have a stabilizing effect which results in a conditional severe threat on Day 2/Friday. Some guidance shows a strengthening surface low which results in substantial return flow across the eastern Carolinas, which will result in low 60s dewpoints and weak to moderate instability by later morning to early afternoon. However, if this stronger cyclogenesis does not occur (as forecast by several hi-res models this morning), the instability and severe weather threat will remain mostly offshore. No modifications were made to the marginal risk, but a 2% tornado probability was added for parts of eastern North Carolina. If stronger southerly/southeasterly flow and low 60s dewpoints can develop ahead of a strengthening surface low, a tornado is possible. Overall, a few strong to isolated severe storms are possible with a primary threat of large hail. However, this threat is conditional on destabilization, which remains questionable at this time. ...Southeast Georgia and northern Florida... Strong heating is anticipated along a frontal zone from southeast Georgia to northern Florida Friday afternoon. Forecast soundings show 500 to 750 J/kg MLCAPE with a well-mixed boundary layer extending to near 3km. Overall lack of moisture should limit instability and storm intensity, but 35 to 45 knots of shear will support some storm organization. Therefore, the strongest storms could exhibit some updraft rotation with an increased large hail/severe wind threat, but overall expect the threat to remain isolated. ..Bentley.. 04/10/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Thu Apr 10 2025 Valid 101700Z - 111200Z ...Morning Update... The prior outlook remains valid with only minor modifications. The Elevated area was expanded across parts of central SD where post-frontal gusty winds of 15-20 mph and low RH are expected for a few hours this afternoon. Areas across western SD have received around 0.25-0.5 inches of rainfall over the last 24 hours, and have been trimmed from the risk area. Otherwise the outlook was unchanged, see the previous discussion. ..Lyons.. 04/10/2025 .PREV DISCUSSION... /ISSUED 1149 PM CDT Wed Apr 09 2025/ ...Synopsis... A mid-level trough will amplify across the eastern CONUS as upper ridging persists across the Interior West, supporting surface high pressure and deep-layer northwesterly flow to overspread the central Plains today. Given the presence of a dry boundary layer, efficient downward momentum transport of the stronger flow aloft is expected by afternoon peak heating given boundary-layer mixing. Widespread 15-20 mph northwesterly surface winds (perhaps reaching 25 mph locally) will coincide with 20 percent RH for several hours across parts of the central Plains, warranting the continuation of Elevated highlights given at least modestly dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Thu Apr 10 2025 Valid 101700Z - 111200Z ...Morning Update... The prior outlook remains valid with only minor modifications. The Elevated area was expanded across parts of central SD where post-frontal gusty winds of 15-20 mph and low RH are expected for a few hours this afternoon. Areas across western SD have received around 0.25-0.5 inches of rainfall over the last 24 hours, and have been trimmed from the risk area. Otherwise the outlook was unchanged, see the previous discussion. ..Lyons.. 04/10/2025 .PREV DISCUSSION... /ISSUED 1149 PM CDT Wed Apr 09 2025/ ...Synopsis... A mid-level trough will amplify across the eastern CONUS as upper ridging persists across the Interior West, supporting surface high pressure and deep-layer northwesterly flow to overspread the central Plains today. Given the presence of a dry boundary layer, efficient downward momentum transport of the stronger flow aloft is expected by afternoon peak heating given boundary-layer mixing. Widespread 15-20 mph northwesterly surface winds (perhaps reaching 25 mph locally) will coincide with 20 percent RH for several hours across parts of the central Plains, warranting the continuation of Elevated highlights given at least modestly dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Apr 10 2025 Valid 101630Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY INTO THE SOUTHEAST... ...SUMMARY... Scattered strong to severe thunderstorms are expected from portions of the lower Ohio Valley into the Deep South this afternoon and evening. Large hail and damaging winds should be the main threats. ...Lower Ohio Valley into the Southeast... Large-scale upper troughing is forecast to further amplify today over the eastern CONUS, as multiple embedded shortwave troughs rotate through its base. A lead shortwave trough will advance eastward over the upper OH Valley and central Appalachians through the day, while a trailing shortwave trough is expected to move southeastward across the mid MS Valley, lower OH Valley, and TN Valley through this evening. A weak/diffuse cold front is likewise forecast to develop southeastward across these regions through the day, providing some focus for thunderstorm development later this afternoon and evening. 12Z soundings across the Southeast indicate shallow/limited low-level moisture in place, but also relatively steep mid-level lapse rates. Strong daytime heating, gradual low-level moistening from the southwest, and cooling mid-level temperatures associated with the trailing shortwave trough should all aid in the development of around 1000-1500 J/kg of MLCAPE ahead of the front by mid afternoon. Weak low-level westerly winds are forecast to gradually veer and strengthen with height through the mid/upper levels, which will likely foster relatively long/straight hodographs and 40-55+ kt of effective bulk shear. This should easily support organized updrafts, including the potential for supercells. Current expectations are for robust thunderstorm development to occur over the lower OH Valley/Mid-South region by 18-20Z. This initial activity will likely be supercellular, with an associated threat for large hail given steep lapse rates aloft and strong deep-layer shear. Additional strong to severe thunderstorms should develop through the rest of the afternoon and early evening across a larger portion of the lower OH Valley into the TN Valley and Southeast. Any convection which can remain at least semi-discrete should pose a continued hail threat. Some tendency for upscale growth into multiple bowing clusters seems likely by late afternoon/early evening. A well-mixed boundary layer should support efficient downward momentum transfer and a threat for scattered damaging winds, before convection eventually weakens by mid/late evening with the loss of daytime heating. ..Gleason/Guyer.. 04/10/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Apr 10 2025 Valid 101630Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY INTO THE SOUTHEAST... ...SUMMARY... Scattered strong to severe thunderstorms are expected from portions of the lower Ohio Valley into the Deep South this afternoon and evening. Large hail and damaging winds should be the main threats. ...Lower Ohio Valley into the Southeast... Large-scale upper troughing is forecast to further amplify today over the eastern CONUS, as multiple embedded shortwave troughs rotate through its base. A lead shortwave trough will advance eastward over the upper OH Valley and central Appalachians through the day, while a trailing shortwave trough is expected to move southeastward across the mid MS Valley, lower OH Valley, and TN Valley through this evening. A weak/diffuse cold front is likewise forecast to develop southeastward across these regions through the day, providing some focus for thunderstorm development later this afternoon and evening. 12Z soundings across the Southeast indicate shallow/limited low-level moisture in place, but also relatively steep mid-level lapse rates. Strong daytime heating, gradual low-level moistening from the southwest, and cooling mid-level temperatures associated with the trailing shortwave trough should all aid in the development of around 1000-1500 J/kg of MLCAPE ahead of the front by mid afternoon. Weak low-level westerly winds are forecast to gradually veer and strengthen with height through the mid/upper levels, which will likely foster relatively long/straight hodographs and 40-55+ kt of effective bulk shear. This should easily support organized updrafts, including the potential for supercells. Current expectations are for robust thunderstorm development to occur over the lower OH Valley/Mid-South region by 18-20Z. This initial activity will likely be supercellular, with an associated threat for large hail given steep lapse rates aloft and strong deep-layer shear. Additional strong to severe thunderstorms should develop through the rest of the afternoon and early evening across a larger portion of the lower OH Valley into the TN Valley and Southeast. Any convection which can remain at least semi-discrete should pose a continued hail threat. Some tendency for upscale growth into multiple bowing clusters seems likely by late afternoon/early evening. A well-mixed boundary layer should support efficient downward momentum transfer and a threat for scattered damaging winds, before convection eventually weakens by mid/late evening with the loss of daytime heating. ..Gleason/Guyer.. 04/10/2025 Read more

No Mesoscale Discussions are in effect as of Thu Apr 10 13:36:01 UTC 2025.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Thu Apr 10 2025 Valid 101300Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE LOWER OH VALLEY INTO THE DEEP SOUTH... ...SUMMARY... Scattered strong-severe thunderstorms are expected from portions of the lower Ohio Valley into the Deep South this afternoon. Hail and wind are the primary concerns. ...Synopsis... Broad upper troughing is forecast to shift eastward across the eastern CONUS today, as a series of embedded shortwave trough progress through its base. The lead wave in this series is currently moving through Lower/Middle OH Valley with a second wave farther back northwest across the Upper Midwest/Mid MO Valley. This second wave, which is accompanied by an 80 kt 500 mb jet streak, is expected to continue southeastward throughout the day, reaching the Mid-South vicinity by this evening before continuing more eastward into southern Appalachians by early Friday. Surface pattern preceding this upper troughing will be somewhat disorganized and broad, with one weak low moving northeastward across the Upper OH Valley and another moving southeastward across the Mid MS Valley and KY/TN. A diffuse cold front is forecast to shift southeastward across the OH Valley into the Mid-South and eventually the Southeast. Strong to severe thunderstorms are anticipated in the vicinity of this front throughout the afternoon and evening. ...Mid-South/TN and OH Valleys into the Southeast... Area soundings reveal the steep mid-level lapse rates (i.e. greater than 7 deg C per km) extend throughout much of the region, supported by a large area of cold mid-level temperatures (-18 to -24 deg C at 500 mb). These cold mid-level temperatures will help support airmass destabilization and modest buoyancy ahead of the approaching shortwave trough and cold front, despite relatively modest low-level moisture. Forcing for ascent along the front, as well as more broad large-scale ascent, will interact with this destabilized airmass to support thunderstorm development across much of the region this afternoon. Thunderstorm coverage will likely be maximized along the front, but initiation could also occur elsewhere across the region given the broad ascent and large destabilized area. Deep mixing is anticipated across the region, resulting in a thermodynamic profile that is somewhat unique for this part of the country. This profile will result in high-based thunderstorms capable of producing strong cold pools, particularly given that shear is quite strong and updraft organization is likely. Primary factor precluding greater severe potential is the limited low-level moisture and resulting modest buoyancy. That being said, the long hodographs suggest storms could be efficient at producing hail during their initially more discrete stage, with a trend towards cold pool amalgamation thereafter. Consequently, several bowing segments could develop, each with the potential to produce damaging gusts. ..Mosier/Kerr.. 04/10/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0333 AM CDT Thu Apr 10 2025 Valid 131200Z - 181200Z ...DISCUSSION... Primary feature of interest will be a shortwave trough over MT at 12Z Sunday and its major amplification into a broad eastern CONUS/southeast Canadian trough through mid-week. Poleward moisture quality from the western Gulf will remain sub-optimal, but will improve through D5/Monday. The northeast extent of weak surface buoyancy should reach the OH Valley by Monday afternoon, where guidance has been trending farther south with an intense mid-level jet. Given a prior EML and the deep surface cyclone tracking over Lake Superior to central ON vicinity, convective coverage may be limited along the trailing cold front. Still, consensus of guidance suggests that some fast-moving convection should accompany the portion of the front in the OH Valley vicinity. Robust 700-500 mb wind profiles should offer at least a threat for damaging winds. Depending upon timing of frontal passage, a limited-area severe threat may exist on D6/Tuesday along the Southeast Atlantic coast. A compact southern-stream shortwave impulse, approaching the backside of the broad east CONUS trough, indicates low-probability severe potential over the southern Great Plains on D7/Wednesday into the western Gulf Coast vicinity D8/Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0333 AM CDT Thu Apr 10 2025 Valid 131200Z - 181200Z ...DISCUSSION... Primary feature of interest will be a shortwave trough over MT at 12Z Sunday and its major amplification into a broad eastern CONUS/southeast Canadian trough through mid-week. Poleward moisture quality from the western Gulf will remain sub-optimal, but will improve through D5/Monday. The northeast extent of weak surface buoyancy should reach the OH Valley by Monday afternoon, where guidance has been trending farther south with an intense mid-level jet. Given a prior EML and the deep surface cyclone tracking over Lake Superior to central ON vicinity, convective coverage may be limited along the trailing cold front. Still, consensus of guidance suggests that some fast-moving convection should accompany the portion of the front in the OH Valley vicinity. Robust 700-500 mb wind profiles should offer at least a threat for damaging winds. Depending upon timing of frontal passage, a limited-area severe threat may exist on D6/Tuesday along the Southeast Atlantic coast. A compact southern-stream shortwave impulse, approaching the backside of the broad east CONUS trough, indicates low-probability severe potential over the southern Great Plains on D7/Wednesday into the western Gulf Coast vicinity D8/Thursday. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0154 AM CDT Thu Apr 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday or Saturday night. ...Central Rockies to the Upper Midwest... A mid-level ridge from the southern High Plains to the Upper Midwest at 12Z Saturday morning will shift east and gradually dampen, as a shortwave trough progresses across the northern Rockies and into MT through early Sunday. Large-scale ascent will strengthen near peak diurnal heating across parts of the central Rockies to the Black Hills. With only scant buoyancy, isolated/short-lived thunderstorms are anticipated amid scattered high-based/low-topped showers. Where deeply mixed thermodynamic profiles exist in eastern WY and western SD, a very isolated strong gust will be possible. Strengthening of the Great Plains LLJ on Saturday night should eventually yield isolated thunder potential across the Mid-MO Valley into the Upper Midwest. With poor-quality moisture return relative to the EML, uninhibited parcels may be rather elevated. The threat for severe hail overnight in this setup appears low. ..Grams.. 04/10/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0154 AM CDT Thu Apr 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday or Saturday night. ...Central Rockies to the Upper Midwest... A mid-level ridge from the southern High Plains to the Upper Midwest at 12Z Saturday morning will shift east and gradually dampen, as a shortwave trough progresses across the northern Rockies and into MT through early Sunday. Large-scale ascent will strengthen near peak diurnal heating across parts of the central Rockies to the Black Hills. With only scant buoyancy, isolated/short-lived thunderstorms are anticipated amid scattered high-based/low-topped showers. Where deeply mixed thermodynamic profiles exist in eastern WY and western SD, a very isolated strong gust will be possible. Strengthening of the Great Plains LLJ on Saturday night should eventually yield isolated thunder potential across the Mid-MO Valley into the Upper Midwest. With poor-quality moisture return relative to the EML, uninhibited parcels may be rather elevated. The threat for severe hail overnight in this setup appears low. ..Grams.. 04/10/2025 Read more