
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Sun Apr 19 2026 Valid 221200Z - 271200Z ...DISCUSSION... A western trough will take hold in the days preceding this convective period. Ahead of this trough moisture will return northward through the central Plains, with 50F dewpoints reaching perhaps as far north as the Canadian border during Wednesday/Day-4. This return flow setup and western trough will set the stage for multiple days of severe weather potential. On Wednesday/Day-4, a lobe of vorticity will eject northeast out of the western longwave trough across the central and northern Plains. As this occurs, surface cyclogenesis should take place across the far northern Plains. To the south of this surface low, a dryline should sharpen across western Nebraska and Kansas. At the same time, vertical shear should strengthen as the shortwave moves northeast across the region. The kinematic profiles will support supercells initiating along the dryline. However, concerns remain about the quality of the moisture to the east of the dryline and subsequently as to the number of potential thunderstorms that may develop. This uncertainty precluded the introduction of unconditional 15% probabilities at this time. On Thursday/Day-5, the shortwave trough/midlevel low will deepen as it slowly moves north-northeast during the day. This will help maintain a strong surface cyclone across the northern Plains, with strong southerly winds advecting Gulf moisture northward to the east of the north-south oriented frontal boundary. Showers and thunderstorms will be possible along and east of the aforementioned frontal boundary across a large portion of the central US. Strong vertical wind shear across this frontal boundary will promote severe potential from Oklahoma northward to perhaps as far north as Minnesota. The northern extent of the severe potential will be delimited by the degree of moisture return, and have expanded the unconditional 15% probability area northward into Iowa to account for the increasing confidence in severe thunderstorm potential. Overnight Thursday/Day-5, a surface cold front, augmented by convective outflow, should push east across the northern and central Plains and south-southeast across the southern Plains. Another round of severe thunderstorms will be possible on Friday/Day-6 across portions of northeast Texas/northern Louisiana and much of Arkansas as diurnal heating of a moist airmass results in MUCAPE values between 1000-2000 J/kg beneath modest vertical shear associated persistent southwest midlevel flow. The severe potential will likely persist into Saturday/Day-7 and Sunday/Day-8 across portions of the southern Plains and northern Gulf Coast states. Here, persistent western troughing will maintain an increasingly moist airmass along and south of the aforementioned frontal boundary. The location of this frontal boundary will likely be significantly impacted by the repeated rounds of thunderstorms in the prior days. Model guidance is in general agreement that at least modest westerly/southwesterly flow will persist across the southern Plains, with episodic perturbations traversing this flow field downstream of the broader large-scale western trough. However, significant differences remain with respect to the timing, strength, and location of any of these perturbations to attempt to highlight unconditional severe probabilities.Read more

Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 AM CDT Sun Apr 19 2026 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms will be possible across the western CONUS, the south-central CONUS, and the southern Great Lakes. No severe weather is anticipated. ... Synopsis ... A large-scale midlevel trough will move push inland across the western CONUS into the Great Basin on Wednesday, with downstream ridging building across the central CONUS in response. Across the Northeast, northwest flow aloft will prevail downstream of the central CONUS ridge. An embedded jet streak and associated vorticity maximum within the northwest flow will aid driving a weak surface low and attendant frontal boundary southeast across the Great Lakes through the forecast period. Meanwhile, the surface ridge across the Southeast will move east, just offshore of the Southeast Atlantic Coast, promoting return flow across the Plains. The return flow will be aided by the development of lee troughing across much of the High Plains. ... Western US ... Scattered showers are expected across portions of the West in association with the inland-moving large-scale trough. Seasonably cool midlevel temperatures will support enough instability for a few thunderstorms, although severe potential is very low. ... South-central US ... Showers and thunderstorms will be possible across the region within the return flow regime. Here, weak warm-air advection combined with between 500-1000 J/kg of MUCAPE will support convective development. Weak vertical shear and the lack of strong forcing for ascent should limit any severe potential. ... Southern Great Lakes ... Scattered showers a few thunderstorms will be possible within the surface frontal zone as it pushes south/southeast during the day. Instability around 500 J/kg MUCAPE and weak effective layer shear should preclude a more robust severe weather event, but a strong wind gust or two may be possible. ..Marsh.. 04/19/2026Read more

Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0204 AM CDT Sun Apr 19 2026 Valid 201200Z - 211200Z ...Synopsis... Areas of elevated fire weather conditions are expected across parts of the High Plains and the Southeast on Monday. Upper-level ridging will gradually shift east from the Rockies into the Plains through the day. While surface high pressure shifts east over the Southeast states, a lee trough will deepen along the northern High Plains, resulting in areas of breezy conditions over dry fuels. ...High Plains... A deepening lee trough along the northern High Plains will support strengthening west/southwest winds to the west of the trough axis across eastern WY into western NE. Further south, a tightening pressure gradient in proximity to a lingering surface high over eastern TX will promote strengthening winds across the OK/TX Panhandle region. Within both regimes, ensemble guidance suggests sustained winds between 15-20 mph are likely. RH minimums in the teens are likely across WY into NE where downslope wind will depress moisture content within an antecedent dry air mass. Further south, the northern fringe of returning moisture will begin nosing into western TX. This may limit RH reductions to some degree, but RH minimums will likely fall into at least the low 20s given model guidance tendency to display a moist bias at the surface within the early stages of moisture return. ...Southeast... A dry air mass will reside across much of the Southeast where fuels will likely remain dry owing to limited rainfall forecast over the next 24-48 hours for much of the region. In general, gradient winds will weaken through the day as surface high pressure builds across the region. However, areas of breezy conditions will likely persist in the lee of the southern Appalachians and along the northeastern Gulf coast. Sustained winds near 15 mph within a dry air mass (RH minimums in the teens to twenties) will likely support another day of elevated fire weather conditions. ...New Mexico to eastern Arizona... Low to mid-level moisture return is anticipated across southern TX and into central NM through Monday afternoon. Although forcing for ascent will be modest under an upper-level ridge, a combination of localized orographic ascent and deeply mixed boundary-layers with minimal inhibition will support isolated thunderstorm development. Storm motions around 10 knots will likely support pockets of wetting precipitation, but PWAT values between 0.6 to 0.7 inches will likely support dry lightning strikes outside of the heavier precipitation cores. With regional ERCs near the 75th to 80th percentile, lightning ignitions appear possible. ..Moore.. 04/19/2026 ...Please see www.spc.noaa.gov/fire for graphic product...Read more

Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sun Apr 19 2026 Valid 191200Z - 201200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH PLAINS... ...Synopsis... Elevated to critical fire weather conditions are expected this afternoon across portions of the southern and central High Plains as well as across parts of the Southeast. Both fire weather regimes will be influenced by building surface high pressure in the wake of a cold front pushing into the northern Gulf and southeast Atlantic coast. ...Central/Southern High Plains... Building surface high pressure is noted across the southern Plains with very dry conditions (dewpoints in the teens to single digits) observed across western TX into western KS. Southwest winds are forecast to strengthen to 15-25 mph on the western periphery of the surface high this afternoon as a dry return flow regime becomes established. Mostly sunny skies coupled with very low boundary-layer moisture will support deep mixing and RH minimums in the single digits to low teens. Critical fire weather conditions remain likely across the TX/OK Panhandles into southwest KS where gusts up to 30 mph appear likely. Given recent fire activity across northwest TX, the fuel environment will support the fire weather threat. ...Southeast States... 06 UTC surface observations depict a cold front pushing eastward across the Southeast. Although scattered showers accompany this front, latest forecast depicts low probability for wetting rainfall across northern FL into central GA and SC, which will likely be insufficient to mitigate ERC values well above the 95th percentile. In the wake of the cold front, west/northwest winds will prevail across much of the region. A combination of dry air advection and downslope flow off the southern Appalachians will contribute to widespread 15-25% RH minimums. Elevated to locally critical fire weather conditions should become fairly widespread as winds increase into the 15-20 mph with localized gusts upwards of 25-30 mph. ..Moore.. 04/19/2026 ...Please see www.spc.noaa.gov/fire for graphic product...Read more