Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CST Fri Dec 09 2022 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Isolated severe thunderstorms are possible across portions of the southern Plains from Saturday morning into early Sunday morning. ...Synopsis... A southern-stream shortwave trough is expected to progress from northwest Mexico/southern AZ eastward through the southern High Plans and much of the southern Plains on Saturday. At the same time, an upper low is forecast to drop southward to the Pacific Northwest Coast as a series of shortwave troughs rotate through its western and southern periphery. An additional shortwave should move from the northern Plains eastward through the Upper Midwest and into the Upper Great Lakes region. At the surface, moisture return is anticipated across the southern Plains and Lower MS Valley ahead of the approaching southern-stream shortwave. A surface low will likely be centered over south-central OK early Saturday, before then pushing eastward across southeast OK and southern AR. As it does, an associated cold front is expected to progress gradually southeastward across TX. Resulting increasing buoyancy coupled with strengthening wind fields and lift will contribute to some severe risk across the southern Plains. Isolated lightning flashes are also possible from the southwest OR coast into central CA and west-central NV where cold mid-level temperatures and persistent large-scale forcing for ascent will align. ...Southern Plains... Showers and thunderstorms will likely be ongoing across central and eastern OK early Saturday, north of the low and attendant cold front. These showers and thunderstorms should gradually diminish as the low-level jet weakens, with additional activity expected to develop farther west in the vicinity of the front across southwest/south-central OK and north TX. Much of this activity will be elevated north of the front, but instability and shear are expected to be strong enough to support a low-probability hail threat. Isolated thunderstorm development within the warm sector is possible Saturday evening into Sunday morning as the shortwave moves closer and large-scale ascent strengthens. Southerly/southeasterly surface winds will result in curved low-level hodographs, but the overall magnitude will remain low due to modest low-level flow. Even so, a few more organized storms are possible, with an attendant threat of damaging gusts and/or a brief tornado. ..Mosier.. 12/09/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Fri Dec 09 2022 Valid 091630Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through early Saturday. ...Synopsis... Several mid-level shortwave troughs are present amid a progressive mid-level pattern across the western two-thirds of the CONUS. A weakening mid-level trough will advance across the southern Great Lakes through the day today with a larger trough advancing across the Rockies in its wake. Additionally, another trough is approaching the West Coast which will bring moderate/heavy valley rain and mountain snow. As the mid-level trough over the Great Basin this morning advances into the Plains tonight, a low-level jet is expected to strengthen across the southern High Plains. As warm air advection strengthens and moisture increases, expect thunderstorms to develop across Oklahoma, mostly after 03Z and expand east-northeastward through the overnight period and into Saturday morning. Thunderstorm chances will increase along the northwest California/ southwest Oregon coast after 06Z as the trough advances east and colder air aloft overspreads relatively moist low level conditions. These thunderstorms may start to spread further inland closer to 12Z as the upper-level trough continues to advance east. ..Bentley.. 12/09/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0909 AM CST Fri Dec 09 2022 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/09/2022 .PREV DISCUSSION... /ISSUED 0155 AM CST Fri Dec 09 2022/ ...Synopsis... Across the CONUS, active mid-level flow is expected to remain in place today as a shortwave trough crosses the southern and central Rockies onto the High Plains. In response to increasing westerly flow aloft, downslope winds across proportions of southern CO and northern NM may occasionally reach 15-20 mph through the afternoon. While not overly warm, temperatures in the 40s and 50s F along with downslope drying and occasional stronger wind gusts may support a few hours of locally elevated fire weather potential from the Front Range into northern NM. However, relatively modest fuels and the limited overlap of gusty winds and dry surface conditions should limit the duration of any threat. Elsewhere across the CONUS, fire weather concerns are low. ...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 1243 PM CST Thu Dec 08 2022 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... No changes are needed to the current D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 12/08/2022 .PREV DISCUSSION... /ISSUED 0108 AM CST Thu Dec 08 2022/ ...Synopsis... The potential for widespread fire weather concerns is low for Friday across the CONUS, but localized fire weather conditions may develop for parts of eastern Colorado. The upper disturbance currently approaching the Plains will quickly be followed by upper ridging across the central U.S. on Friday. Height falls across the Southwest will support increasing flow over the central Rockies with modest lee troughing in response. 15 mph southerly winds may occasionally gust up to 20-25 mph from northeast NM into eastern CO and far western KS where fine fuels remain dry. No appreciable moisture return will maintain dry conditions with afternoon RH values in the 15-25% range. Consequently, localized elevated fire weather conditions are probable where dry conditions can overlap with breezier winds. However, confidence in the spatial coverage and duration of elevated conditions remains too limited due to uncertainty in wind magnitudes, precluding highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Thu Dec 8 18:45:02 UTC 2022.

No watches are valid as of Thu Dec 8 18:45:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CST Thu Dec 08 2022 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not forecast across the U.S. on Friday. ...Synopsis... A series of mid-level shortwave troughs will move across the central states on Friday. The lead disturbance will move from IA/MO and weaken as it moves to the Lake Erie vicinity. An upstream mid-level trough will move from the Interior West east-northeastward into the northern and central Great Plains by early Saturday. At the surface, a front will be draped from west Texas through the lower MS Valley and AL/GA. Low-level moisture will increase over parts of northwest TX/OK late in the period as showers/thunderstorms become more common Friday night. Weak buoyancy and the lack of stronger forcing will very likely limit thunderstorm intensity and any risk for severe thunderstorm development. ..Smith.. 12/08/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Thu Dec 08 2022 Valid 081700Z - 091200Z Morning satellite analysis shows skies are clearing from west to east across eastern Colorado/Western Kansas. Clear skies and strengthening westerly winds will promote deep mixing of drier air aloft to the surface, with further drying and warming aided by strong downslope flow. Gusts around 40 mph are already being observed this morning, with further strengthening expected for the afternoon. The current Elevated area covers the threat for increased fire weather potential this afternoon. As mentioned below, localized critical conditions will be possible in the lee of the high terrain where the strongest winds are expected. ..Thornton.. 12/08/2022 .PREV DISCUSSION... /ISSUED 1236 AM CST Thu Dec 08 2022/ ...Synopsis... Elevated fire weather conditions are expected across portions of southeast CO and adjacent areas of far southwest KS and far northeast NM. Latest surface observations shows weak cyclogenesis over the greater Panhandles region with modest surface pressure falls further north along the central High Plains ahead of an approaching upper wave. This surface low will consolidate across the central Plains over the next 24 hours, inducing 15-25 mph west/northwest winds off the central Rockies. Downslope warming/drying will yield RH values in the teens and low 20s over a region with dry fine fuels after little rainfall over the past 14 days. Elevated fire weather conditions appear likely across southeast CO with localized critical conditions possible, especially in the immediate lee of the terrain where gusts will likely approach 35 mph. ...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 1026 AM CST Thu Dec 08 2022 Valid 081630Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm threat appears negligible through early Friday. ...TX to TN... Morning surface analysis shows a quasi-stationary boundary extending from central TX northeastward into the TN Valley. Rich low-level moisture is present to the south of the boundary, with dewpoints in the mid-upper 60s noted. However, poor mid-level lapse rates and relatively warm temperatures aloft will limit CAPE values and the overall threat of deep convection. This corridor also lies beneath general large-scale ridging, suggesting little organized lift will occur. Therefore, scattered showers but only isolated thunderstorms are expected in vicinity of the front this forecast period. ..Hart/Squitieri.. 12/08/2022 Read more

No watches are valid as of Wed Dec 7 17:45:01 UTC 2022.

No Mesoscale Discussions are in effect as of Wed Dec 7 17:45:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1117 AM CST Wed Dec 07 2022 Valid 081200Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States on Thursday. ...Synopsis... A mid-level disturbance, embedded within strong high-level flow from the Desert Southwest through the Mid-Atlantic states, will move from the central Rockies to the middle MS Valley during the period. Only weak surface reflection is expected over the central U.S. with much of the stronger large-scale forcing for ascent displaced north of a front draped from OK eastward across the Mid South. Showers and a few elevated thunderstorms will likely be ongoing Thursday morning from OK and the Ozarks, with this activity moving east across KY/TN during the day. Additional isolated storms are possible later in the day from parts of north TX to the AR/TN/MS vicinity. However, weak lapse rates and associated buoyancy will limit storm intensity. Elsewhere, showers and couple of thunderstorms are possible along the Pacific Northwest coast as an upstream mid-level trough moves ashore. ..Smith.. 12/07/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1038 AM CST Wed Dec 07 2022 Valid 071700Z - 081200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 12/07/2022 .PREV DISCUSSION... /ISSUED 0103 AM CST Wed Dec 07 2022/ ...Synopsis... Fire weather concerns will be limited for today across the country. Dry conditions are expected to persist across the central High Plains where a dry air mass remains in place (dewpoints in the low to mid teens). Afternoon RH values in the 25-35% range over a region with modestly dry fuel introduces the potential for low-end fire weather concerns. However, wind speeds are expected to largely be limited given weak cyclogenesis across the southern High Plains and a building surface high over the northern Plains/upper MS River Valley. Latest ensemble guidance supports this idea with low probability for widespread winds above 15 mph. Localized elevated conditions are possible across eastern CO, southeast WY and adjacent areas of NE/KS, but the potential appears too limited for highlights. ...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 1022 AM CST Wed Dec 07 2022 Valid 071630Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Discussion... Around the northwest periphery of the persistent mid-upper ridge over the Gulf of Mexico, a shortwave trough over the Great Basin will eject eastward to the southern Rockies. A cool air mass entrenched from much of OK and northwest TX northward will yield muted lee cyclogenesis downstream of the ejecting trough, such that the surface baroclinic zone will move little from north TX to the TN Valley through tonight. Isolated thunderstorms will be possible, mainly through this afternoon, along the front from the Mid-South into the TN Valley, and over the Four Corners vicinity in association with the Great Basin trough. Scattered thunderstorms are most likely this evening into tonight as low-level warm theta-e advection strengthens from west TX towards the Ozarks. Much of this activity should remain on the cool side of the baroclinic zone. Marginal mid-level lapse rates resulting in weak elevated buoyancy should preclude appreciable severe potential. ..Grams/Squitieri.. 12/07/2022 Read more

No watches are valid as of Tue Dec 6 17:46:02 UTC 2022.

No Mesoscale Discussions are in effect as of Tue Dec 6 17:46:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CST Tue Dec 06 2022 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not forecast across the U.S. on Wednesday. ...Synopsis... A mid-level trough initially over the Mojave Desert will move east through the Great Basin and to the central Rockies by early Thursday morning. A larger-scale mid-level trough will pivot east from the Upper Midwest to the Northeast while weak mid-level ridging occurs over the middle MS Valley in its wake. In the low levels, a cold front will slide southeast across KY/TN and the Mid-Atlantic states and Northeast during the period. The stalled western portion of the boundary will advance northward as a warm front from the OK-TX Red River into central OK by late Wednesday night. Scattered showers and isolated thunderstorms are likely during the morning from the MS-AR Delta region east-northeastward into WV/western VA with lower coverage farther west in north TX. Sporadic shower/thunderstorm activity will probably linger from MS westward into north TX during the afternoon. As low-level warm-air advection intensifies during the evening into the overnight across the southern Great Plains, scattered thunderstorms will likely develop near the front. Moist profiles yielding modest lapse rates will limit storm intensity and severe weather is not expected. ..Smith.. 12/06/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1037 AM CST Tue Dec 06 2022 Valid 061700Z - 071200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 12/06/2022 .PREV DISCUSSION... /ISSUED 1225 AM CST Tue Dec 06 2022/ ...Synopsis... Fire weather concerns remain limited for today across the CONUS. Recent low-level water vapor imagery continues to show modest subsidence/drying in the lee of the southern Rockies amid a persistent west/southwest flow regime aloft. This pattern will be maintained over the next 24 hours as the upper low over CA gradually translates east. Consequently, another day of dry, breezy conditions is expected across eastern NM in the lee of terrain features. Localized elevated conditions may materialize as far east as the western TX Panhandle, but the combination of low probability for sub-20% RH away from terrain features, weakening boundary-layer winds, and unreceptive fuels (ERCs near or below seasonal average) will limit the overall fire weather threat. ...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 1029 AM CST Tue Dec 06 2022 Valid 061630Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WESTERN PORTIONS OF KY/TN... ...SUMMARY... A severe thunderstorm or two is possible this evening across western portions of Kentucky and Tennessee. ...Western KY/TN vicinity... Boundary-layer dewpoints into the mid 60s are present south of a warm front that extends from central AR to southern TN. The warm front should make some northward progress into western KY by this evening ahead of a weak wave over the Ozarks. Clouds will remain pervasive, but occasional breaks should help boost MLCAPE to between 500-750 J/kg. The bulk of convective development this evening should be focused within the warm conveyor regime ahead of the frontal wave and north of the surface warm front. Still, there are some indications for convection to backbuild southwestward into the warm sector over a portion of western KY/TN. Moderate low-level hodograph curvature in conjunction with a relatively elongated/straight-line mid to upper-level hodograph would be conditionally supportive of low-end supercell development. While it is plausible that severe storms may ultimately fail to materialize, there appears to be enough signal to warrant a low probability for a brief tornado and locally damaging winds. ..Grams/Squitieri.. 12/06/2022 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0111 PM CST Mon Dec 05 2022 Valid 061200Z - 071200Z ...NO CRITICAL AREAS... No updates are needed to for the D2 Fire Weather Outlook. See previous discussion below for more details. ..Thornton.. 12/05/2022 .PREV DISCUSSION... /ISSUED 0138 AM CST Mon Dec 05 2022/ ...Synopsis... Fire weather concerns are expected to remain minimal for Tuesday across the country. A dry air mass is expected to linger across portions of the southern and central High Plains. Modest downslope flow will foster another day of 25-35% RH by late afternoon with west winds near 15 mph. Localized elevated conditions are possible from eastern NM and southern CO in the lee of terrain features into portions of the TX Panhandle. However, ERCs across this region are expected to remain near to below seasonal average and will limit the overall fire weather potential. ...Please see www.spc.noaa.gov/fire for graphic product... Read more