
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 12 2026 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHWEST AND CENTRAL TX... ...SUMMARY... Isolated to scattered severe thunderstorms are possible today into evening mainly across parts of Texas and perhaps other nearby parts of the southern Plains. More isolated severe storms may occur across portions of the Upper Great Lakes and northern Rockies. ...Synopsis... Recent satellite imagery shows a pair of phased shortwave troughs over the Plains, one moving through the Dakotas and another moving through KS/OK. Both of these waves are forecast to continue northeastward through the day, with the northern wave reaching northwestern Ontario and the southern wave reaching the Great Lakes region. This evolution will take these waves east/northeast of the higher low-level moisture, which will remain in a corridor from the southern Plains northeastward into the Upper Midwest. Showers and thunderstorms are anticipated throughout much of this corridor today, with highest thunderstorm chances across central/east TX and from the Upper Midwest into the Great Lakes. Farther west, an upper low is slowly drifting eastward across northern CA. Guidance suggests this eastward drift will continue today, with several shortwave troughs rotating quickly through the base of this system and ejecting across the Great Basin and northern Rockies. Large-scale ascent and modest mid-level moisture associated with these waves will combine with cold temperatures aloft and associated buoyancy to support thunderstorms today from northern CA across the northern Great Basin and northern Rockies, and into the northern Plains. ...Southern/Central Plains... Much of this region will be displaced south and west of any notable large-scale forcing for ascent. This limited ascent, combined with the showers and isolated thunderstorms currently ongoing across central and east TX, complicates the overall forecast today, with mesoscale factors likely contributing significantly to when and where storms develop this afternoon and evening. General expectation is for development along the southern and western periphery on the ongoing storms (i.e. from southeast/south-central TX into southwest TX) later this afternoon and this evening. This redevelopment will be supported by a combination of moist advection, modest heating, and limited low-level convergence. Moderate to strong buoyancy amid moderate vertical shear could support supercells if the mode remains discrete. However, the weakness in the mid-level flow suggests storms may tend to cluster, a scenario that is supported by most CAM guidance. Buoyancy and shear are still strong enough to support rotating updrafts and large hail early in the convective cycle, but the trends towards a messy convective mode could limit the persistence and coverage of robust updrafts. Damaging gusts are possible even with the clustered storm mode, especially given there is some potential for slightly more organized bowing segments over time. Farther west, mid-level height rises/subsidence are anticipated coincident with the dryline from central Kansas south-southwestward across western Oklahoma and west/southwest Texas. The environment, characterized by 1500 to 2000 J/kg of MLCAPE and 30 to 40 kt of westerly deep-layer shear, is conditionally supportive of supercells capable of all severe hazards. However, the previously mentioned height rises and subsidence, combined with modest convective inhibition, are generally expected to preclude thunderstorm development. Even so, given the conditional risk, Marginal risk probabilities will be maintained. ...Minnesota/Wisconsin... Recent surface analysis places a low just west of FAR, with a warm front extending southwestward across central/southeast MN and southern WI. This low is forecast to move eastward today, while the warm front expands northward. A narrow corridor of surface-based buoyancy could develop from north-central MN into far northwest WI as dewpoints increase in the upper 50s (perhaps even low 60s). Thunderstorm initiation appears possible along the cold front within this corridor, although veered low-level flow and northward/westward displacement of the better forcing casts doubt to whether updrafts will be maintained. Any storms that do mature within this warm sector should become supercells capable of all severe hazards, including large hail and tornadoes. However, low confidence in storm development and maturity precludes higher probabilities with this outlook. ...Northern Rockies... Mid-level moisture will support another day of modest surface-based buoyancy ahead of the shortwave trough mentioned in the synopsis. Persistent 30-40 knot flow within the CAPE-bearing layer combined with somewhat deep boundary-layer mixing will support strong to severe downburst winds with the more robust convective cells, mainly this afternoon through early evening. ..Mosier/Squitieri.. 04/12/2026Read more

Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Sun Apr 12 2026 Valid 121700Z - 131200Z ...Central Plains... Dry and breezy conditions in the wake of a departing surface low are still expected across southeastern WY into southern ND and much of northwestern NE through this afternoon. West winds of 15-20 mph along with relative humidity in the 15-20% range will support elevated fire weather conditions as far east as the Sioux Falls area based on latest model guidance, where an eastward expansion of Elevated highlights was appropriate. ...Southeast and Appalachians... A tightening surface pressure gradient between the low entering the Upper Midwest and high pressure sliding eastward off the Mid-Atlantic Coast, will support steady south/southwest sustained winds of around 10 mph (locally 15 mph) across much of the Southeast and Appalachians through today. A relatively dry air mass remains in place with RH falling to as low as 20% during peak afternoon heating. Fuels remain exceptionally dry and receptive to wildfire spread with ERC values reaching into the 95th to 99th percentiles amid an expanding drought. The increased south/southwest flow and low afternoon RH will support a broad area of elevated fire weather conditions from the mid MS River Valley to the OH River Valley. An eastward expansion of Elevated highlights into portions WV, southern Appalachians and northern GA was warranted based on latest near term model guidance. See previous discussion for additional forecast details. ..Williams.. 04/12/2026 .PREV DISCUSSION... /ISSUED 0159 AM CDT Sun Apr 12 2026/ ...Synopsis... Broad and intensifying southwest flow aloft and an intensifying surface cyclone progressing from the northern plains into the upper Midwest will be responsible for widespread dry and windy conditions across much of the southwestern U.S. into the Great Plains this afternoon. ...Southwest and Four Corners... Deeply mixed and dry boundary layer profiles will support strong southwesterly surface winds across much of the Southwest into the Four Corners region, reaching 20 MPH (gusting 25-30 in some regions) with widespread relative humidity of 10-15%. These conditions will coincide with a wide array of fuel conditions ranging from marginally to modestly receptive. Locally Critical conditions may occur, with some signal for a corridor of stronger winds in south-central Utah. However, overall marginal fuels and lack of confidence in the duration and magnitude of surface winds reaching Critical criteria preclude highlights at this time. ...Central High Plains... Surface conditions behind the dryline in the Central High Plains will be quite gusty and dry, with winds of 20-25 MPH and relative humidity as low as 10% across much of the region. However, these conditions overlap a complex fuelsape where recent showers and thunderstorms have dampened fuels across portions of central/southern Colorado into New Mexico. Further north into portions of Wyoming and Nebraska, where fuels are more receptive, winds are expected to remain at or around 20 MPH, with gusts exceeding 25 MPH. Locally critical conditions may occur in portions of northern Nebraska. ...Ohio River Valley/Middle Mississippi Valley... Ongoing drought conditions coupled with dry and breezy southerly flow will result in Elevated fire-weather concerns across portions of the Mississippi Valley into the Ohio River Valley. Surface winds of 10-15 MPH and relative humidity of 25-35% will overlap with fuels exceeding the 95th-99th annual ERC percentiles. ...Please see www.spc.noaa.gov/fire for graphic product...Read more

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 AM CDT Sun Apr 12 2026 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TEXAS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible today into evening mainly across parts of Texas and perhaps other nearby parts of the southern Plains. More isolated severe storms may occur across portions of the Upper Great Lakes and northern Rockies. ...Texas/Southern Plains... A rather complex scenario exists early today attributable to several factors including an MCS that de-intensified/decayed generally near I-35 in Texas overnight, with residual cloud cover and outflow impacts. Potentially focused in vicinity of outflow, the passing mid-level wave and persistent warm/moist advection may support storm persistence and redevelopment/intensification later today across central Texas into parts of east Texas and possibly Louisiana within a moderately unstable environment. In the wake of the mid-level wave, mid-level height rises/subsidence are otherwise anticipated coincident with the dryline from central Kansas south-southwestward across western Oklahoma and west/southwest Texas. The extent and likelihood of storm development later today is highly uncertain, but if/where storms do form, the environment would generally be supportive of supercells and related hazards given ample buoyancy and moderate deep-layer shear. ...Minnesota/Wisconsin... A surface low over the northern Plains will migrate eastward along the U.S./Canadian border through the day, reaching northern Minnesota by around peak heating. A narrow tongue of returning moisture may support a corridor of sufficient ascent and buoyancy for deep convection. A few surface-based supercells could occur along the frontal zone where dewpoints may reach into the mid/upper 50s F. While this potential appears low/uncertain per latest guidance, some tornado threat could materialize along the front. Hail/wind will otherwise be possible regionally on an isolated basis. ...Northern Rockies... Ahead of an approaching upper wave, mid-level moisture will support another day of fairly modest surface-based buoyancy with persistent 30-40 knot flow within the CAPE-bearing layer. Combined with somewhat deep boundary-layer mixing, this may support strong to severe downburst winds with the more robust convective cells, mainly this afternoon through early evening. ..Guyer/Broyles.. 04/12/2026Read more