Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0128 PM CST Wed Jan 11 2023 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Brief locally elevated fire-weather conditions are possible in the dry post-frontal airmass across far south Texas. However, marginal fuels and the limited duration should keep concerns below elevated criteria. ..Lyons.. 01/11/2023 .PREV DISCUSSION... /ISSUED 0157 AM CST Wed Jan 11 2023/ ...Synopsis... A strong shortwave trough will move eastward across the southeastern CONUS through the day tomorrow/Thursday. Northerly surface flow on the west side of the associated surface cyclone will push a surface cold front southward and off the Texas coast into the Gulf of Mexico by midday. Behind this front, expect winds to be breezy (gusts to 15-20 mph) across much of Texas and Oklahoma, but below Elevated criteria for sustained winds. Relative humidity in this region will largely be above elevated criteria, except in south Texas, where 15-20% RH is possible by Thursday afternoon. Fuels in south Texas are modestly dry, with ERCs near the 60th-80th percentile for the time of year. Therefore, Elevated areas were not included in this outlook, though transient elevated conditions may occur. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0041 CONCERNING HEAVY SNOW FOR SOUTHERN NEBRASKA PANHANDLE AND NORTHEASTERN COLORADO
Mesoscale Discussion 0041 NWS Storm Prediction Center Norman OK 1252 PM CST Wed Jan 11 2023 Areas affected...southern Nebraska Panhandle and Northeastern Colorado Concerning...Heavy snow Valid 111852Z - 112145Z SUMMARY...A band of heavy snow will continue to shift eastward across the Nebraska Panhandle southward into northeastern Colorado. Snowfall rates of 1-2"/hr will be possible. DISCUSSION...A band of heavy snow has been ongoing across eastern Wyoming this afternoon and continues to shift eastward across the Nebraska Panhandle into northeastern Colorado. Surface objective analysis and RAP model sounding indicate mid-level lapse rates around 7 C/km coinciding with deep saturation of the dendritic growth zone across much of the region from northeast Colorado into the southern Nebraska Panhandle. This will support snowfall rates of 1-2"/hr. Surface observations have indicated areas of heavy snow with <1/4 visibility across I-80 in Nebraska. Expect quick accumulation and hazardous driving conditions due to low visibility and accumulating snow on roadways. ..Thornton.. 01/11/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 41080464 41550441 41970399 42030344 41860303 41580270 41280262 40920251 40330260 39820272 39320304 38890350 38770406 38910450 39440466 41080464 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CST Wed Jan 11 2023 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OHIO VALLEY SOUTHWARD ACROSS THE MID SOUTH AND PARTS OF THE SOUTHEAST... ...SUMMARY... Isolated to scattered severe thunderstorms appear possible Thursday across parts of the Tennessee/Ohio Valleys, and the Southeast. Damaging winds should be the main threat, but a brief tornado or two may also occur. ...Synopsis... A strengthening upper trough is forecast to move eastward across the eastern half of the U.S. Thursday. By the end of the period, a highly amplified flow field aloft will prevail over the U.S., with a Pacific trough approaching the West Coast, a ridge across the Intermountain West and Canadian Rockies, and a trough over the East. At the surface, a low initially progged to reside near the confluence of the Ohio and Mississippi Rivers will deepen steadily as it shifts northeastward, reaching the Pennsylvania/New York vicinity late. South of the low, a trailing cold front will cross the Mid South and central Gulf Coast states through the day, reaching the Appalachians during the evening. Overnight, the front will continue making steady eastward progress, likely reaching the Atlantic Coast near the end of the period. ...Ohio and Tennessee Valleys into the Southeast... Showers and scattered thunderstorms should be ongoing at the start of the period, ahead of the advancing cold front, from the middle Mississippi/lower Ohio Valleys southward into the central Gulf Coast states. While instability should remain limited overall, due to return of an incompletely modified Gulf boundary layer and substantial cloud cover, storms should nonetheless increase gradually in coverage through the day as a subtle increase in warm-sector CAPE occurs. Given antecedent stability, and a low-level capping inversion, ascent near the front will likely be required to eliminate the inversion and permit storm development -- which suggests largely linear storm mode. Still, with deep-layer flow veering modestly and speed increasing substantially with height, organized updrafts along with locally rotating elements within the line are expected. Damaging winds will likely be the primary risk, likely peaking through the afternoon and then very gradually diminishing during the evening -- in part due to a less favorable thermodynamic environment expected to persist east of the southern Appalachians. A couple of tornadoes will also be possible, across a broad area -- mainly of the brief variety within the linear band of convection. Severe risk will likely decrease more substantially overnight, as frontal convection nears -- and eventually clears -- the Atlantic coast. Convection lingering across Florida as the front slides southward across the Peninsula overnight should remain sub-severe. ..Goss.. 01/11/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1045 AM CST Wed Jan 11 2023 Valid 111700Z - 121200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN NEW MEXICO AND NORTHWEST TEXAS... ...Southern high Plains... Morning satellite imagery showed lingering cirrostratus across portions of the eastern TX Panhandle and northwest TX. This will likely delay heating and mixing across the eastern edge of the outlook area. As such, confidence in sustained elevated/critical conditions is lower, and minor adjustments to the eastern extent have been made. Otherwise, model guidance has trended stronger with winds in recent runs, and isolated gusts of 45+ mph will be possible across portions of west TX and far eastern NM as deep vertical mixing and flow aloft strengthen early this afternoon. Widespread elevated and critical fire-weather conditions are possible where short-hour fuels have dried sufficiently over the preceding days. Please see the previous discussion for additional information. ..Lyons.. 01/11/2023 .PREV DISCUSSION... /ISSUED 0155 AM CST Wed Jan 11 2023/ ...Synopsis... A strong mid-level shortwave trough will cross the central Plains today, and the associated surface cyclone will create gusty winds and dry conditions across the southern High Plains. The guidance consensus indicates the potential for RH of 10-15% and gusts to 35-45 mph over a large portion of the region during the afternoon. Also, after several days of warm, dry conditions, 1-hr fuel moisture levels are near 3-7% across west Texas and into southwest Oklahoma, indicating fine fuels have dried sufficiently to be receptive to fire spread. For the above reasons, elevated conditions were highlighted across eastern New Mexico, west Texas, and into southwest Oklahoma. Additionally, critical fire conditions have been added in far eastern New Mexico and west Texas. ...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 1030 AM CST Wed Jan 11 2023 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-SOUTH AND MIDDLE MISSISSIPPI/LOWER OHIO VALLEYS... ...SUMMARY... Isolated severe thunderstorms are possible late tonight and early Thursday morning from northern Arkansas into parts of the mid Mississippi and lower Ohio Valley. ...Mid-South/Middle Mississippi Valley/Lower Ohio Valley... A southern-stream shortwave trough will emerge from the southern Rockies/southern High Plains today and reach the Ozarks/ArkLaTex late tonight, with surface cyclogenesis occurring tonight from the Ozarks to the lower Ohio Valley in tandem with a northward-expanding warm/moist sector. Surface dewpoints in the upper 50s to lower 60s F will become established late tonight as far north as the Mid-South/western Kentucky vicinity. The warm sector will be capped until late tonight, with the moistening occurring beneath a plume of steepening mid-level lapse rates. By around 06z tonight, the low-level moistening and forcing for ascent within the left-exit region of the strong mid/upper-level jet will support thunderstorm development across northern Arkansas/far southern Missouri. Storms will subsequently move northeastward toward western Kentucky and other parts of the lower Ohio Valley by 09-12z. The steep mid-level lapse rates (>8 C/km), MUCAPE of 500-1500 J/kg, and effective bulk shear of 40-50 kt will support slightly elevated convection (mix of clusters and some supercell structures) capable of producing isolated large hail and damaging winds late tonight and early Thursday. ..Guyer/Thornton.. 01/11/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Tue Jan 10 2023 Valid 111200Z - 121200Z The previous forecast remains valid with only minor adjustments. Model timing with the passage of the cold front across the southern High Plains has trended faster in recent runs favoring more brief fire-weather conditions across the northern TX Panhandle. However, uncertainty on the extent and longevity of elevated to near-critical fire-weather conditions remains high. Thus, the Elevated area has been trimmed slightly south to account for this. Otherwise, the previous discussion remains valid. ..Lyons.. 01/10/2023 .PREV DISCUSSION... /ISSUED 0200 AM CST Tue Jan 10 2023/ ...Synopsis... A shortwave trough will eject over the central Plains during the day tomorrow/Wednesday. An attendant surface cyclone will produce strong, dry downslope flow on Wednesday afternoon across the southern high Plains, where guidance indicates low RH (10-15%) and strong gusts to 25-30 mph are possible. However, 10-hr fuels are only modestly drier than expected for early-mid January. For these reasons, an Elevated area has been introduced over eastern New Mexico and west Texas, though transient critical fire weather conditions are possible in the region. Some uncertainty exists regarding the timing of a cold front on Wednesday afternoon, which will determine the northern extent of elevated fire weather conditions across the Texas and Oklahoma Panhandles. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Tue Jan 10 19:36:01 UTC 2023.

No Mesoscale Discussions are in effect as of Tue Jan 10 19:36:01 UTC 2023.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CST Tue Jan 10 2023 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI/LOWER OHIO VALLEYS... ...SUMMARY... Limited risk for a few strong wind gusts or a brief tornado may evolve late Wednesday night/Thursday morning, across a portion of the mid Mississippi/lower Ohio Valley area. ...Synopsis... An upper trough initially over the Rockies is forecast to move eastward across the Plains through the day, and then to the Mississippi Valley vicinity late, while deepening gradually with time. As this trough advances, a surface cyclone is forecast to pivot eastward from the central High Plains vicinity, to the lower Ohio Valley by the end of the period. ...Parts of the Mid-Mississippi and lower Ohio Valleys... As the aforementioned surface low advances, a cold front will shift southeastward across the southern Plains/Arklatex and eventually the Mississippi Delta region through the second half of the period. Ahead of the front, northward advection of a partially modified airmass will occur, beneath a pronounced low-level thermal inversion. While the strong capping will largely hinder convective development, showers and a few thunderstorms may develop during the last several hours of the period across the Mid Mississippi/lower Ohio Valley vicinity. While CAPE will be quite limited (no more than a few hundred J/kg at most is anticipated), a strong kinematic environment -- including veering/increasing flow with height -- would support organized/rotating updrafts. However, given the persistent capping and very weak instability anticipated in areas where the cap can weaken, suggests only a very limited potential for a strong gust or two, or a brief/weak tornado. ..Goss.. 01/10/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1041 AM CST Tue Jan 10 2023 Valid 101700Z - 111200Z The previous forecast remains valid with only minimal expansion of the Elevated area westward into portions of eastern NM. Gusty winds and dry surface conditions along with above-normal temperatures will support a risk for elevated fire-weather conditions. Otherwise, see the previous discussion. ..Lyons.. 01/10/2023 .PREV DISCUSSION... /ISSUED 0134 AM CST Tue Jan 10 2023/ ...Synopsis... A shortwave trough will traverse the southwestern CONUS through the day today/Tuesday. Associated lee cyclogenesis will produce dry downslope winds this afternoon across the southern high Plains, where latest guidance indicates some overlap of 15-20% RH and 20-25 mph gusts. ERCs in the region are near expected values for early-mid January, though several days of days of warm, dry conditions have resulted in some drying of the 10-hr fuels. Expect elevated fire weather conditions on Tuesday afternoon across far eastern New Mexico and the Texas Panhandle. ...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 1030 AM CST Tue Jan 10 2023 Valid 101630Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM CENTRAL/SOUTHERN CALIFORNIA TO THE SOUTHERN GREAT BASIN... ...SUMMARY... Isolated strong to severe thunderstorms capable of producing damaging winds and perhaps a brief tornado may occur today across parts of southern/central California. Thunderstorms capable of isolated severe gusts will also be possible across parts of southeast Nevada, northwest Arizona, and southwest Utah. ...Central/southern California... Cloud breaks, diurnal heating, and steepening mid-level lapse rates (particularly over central California) should allow for some uptick in more cellular/isolated convection into this afternoon within the post-frontal environment. A couple of locally damaging thunderstorm wind gusts and/or a brief tornado will remain possible into this afternoon over the interior valley and/or near the coast. However, a tendency for veering low-level winds and weakening convergence should lead to a diminished potential over time. ...Southern Great Basin... Coincident with the approach of the upstream shortwave trough and upper jet exit region, there will be a modest increase in low-level moisture immediately ahead of the cold front this afternoon. Surface heating/steepening of low-level lapse rates could support some convectively enhanced wind gusts late this afternoon/early evening via the downward transfer of 50+ kt flow in association with the forced band of convection near the advancing front. ..Guyer/Thornton.. 01/10/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0105 PM CST Mon Jan 09 2023 Valid 101200Z - 111200Z Several days of above normal temperatures and weak downslope flow have resulted in drier fuel conditions across portions of the southern High Plains. With stronger flow expected Tues, several hours of lower RH (below 20%) and breezy winds (15-20 mph) are expected in eastern NM and the TX Panhandle. With the drier fuels, elevated conditions are possible for a few hours. See the previous discussion for more details. ..Lyons.. 01/09/2023 .PREV DISCUSSION... /ISSUED 1157 PM CST Sun Jan 08 2023/ ...Synopsis... A pronounced mid-level trough will approach the Plains states tomorrow/Tuesday, enhancing surface lee troughing across the High Plains and promoting another day of dry downslope flow along the lee of the southern Rockies. Latest guidance consensus suggests that Elevated overlapping surface winds/RH should become more widespread across the southern High Plains compared to Day 1 given the anticipated strength of the approaching upper trough. Furthermore, multiple days of preceding dry conditions and lack of rainfall suggests that finer fuels may be at least modestly receptive to wildfire-spread, especially across the central Texas Panhandle, where Elevated highlights have been introduced. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Mon Jan 9 19:07:01 UTC 2023.

No Mesoscale Discussions are in effect as of Mon Jan 9 19:07:01 UTC 2023.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Mon Jan 09 2023 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NEAR THE CENTRAL AND SOUTHERN CALIFORNIA COAST AND ADJACENT COASTAL MOUNTAINS... ...SUMMARY... Isolated strong to severe thunderstorms capable of producing damaging winds and perhaps a brief tornado may occur Tuesday across parts of southern/central California. ...CA... A potent mid-level shortwave trough will move ashore the CA coast during the day with this feature moving to the Four Corners by daybreak Wednesday. Mid-level cold air advection accompanying the trough will act to weakly destabilize the airmass primarily in the vicinity of the central and southern CA coast and adjacent mountains. A plume of deep-layer moisture from the eastern Pacific will favor scattered to widespread showers and isolated thunderstorms from the coast to areas farther inland (i.e., Mojave Desert and southern Great Basin). Forecast soundings near the coast show weak buoyancy with a strong wind profile featuring veering flow strengthening with height. A few weak, transient embedded cells near the central-southern CA coast may exhibit episodic weak rotation, and perhaps be capable of a localized risk for wind damage or a brief/weak tornado during the day. ..Smith.. 01/09/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1039 AM CST Mon Jan 09 2023 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... The previous forecast remains valid with no changes. Fire concerns today are low, see the previous discussion for more information. ..Lyons.. 01/09/2023 .PREV DISCUSSION... /ISSUED 1157 PM CST Sun Jan 08 2023/ ...Synopsis... A progressive upper-level weather pattern will dominate the CONUS today, with multiple mid-level troughs overspreading the East/West Coasts and the Plains states. With surface lee troughing prevailing across the central U.S., dry downslope flow should develop along the lee of the southern Rockies by afternoon. With surface winds expected to be relatively weak on a widespread basis, Elevated conditions should remain localized to terrain-favoring areas of the southern High Plains. Given the spatially confined nature of such conditions and mediocre fuel status, fire weather highlights have been withheld. ...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 1032 AM CST Mon Jan 09 2023 Valid 091630Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CALIFORNIA... ...SUMMARY... Isolated strong to marginally severe thunderstorms are possible near California coast late tonight and early Tuesday morning. ...Coastal California... Although some near-coastal thunderstorms are possible today, convective potential is expected to increase tonight through early Tuesday as a shortwave trough and jet streak approach the California coast. It appears that a couple hundred J/kg of MLCAPE could support some stronger storms as the frontal band approaches the region. In the presence of strong (40-60 kt) winds through the 1-5 km AGL layer, locally damaging wind gusts and/or a brief tornado could occur late tonight and early Tuesday morning, primarily after 09z. ..Guyer/Thornton.. 01/09/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1238 PM CST Sun Jan 08 2023 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... Weak downslope flow should persist through D2/Monday in the lee of the southern Rockies. However, area fuels remain poorly receptive to fire spread and minimal fire-weather concerns are expected. See previous discussion. ..Lyons.. 01/08/2023 .PREV DISCUSSION... /ISSUED 1218 AM CST Sun Jan 08 2023/ ...Synopsis... Similar to Day 1, another mid-level impulse will traverse the Southern Plains tomorrow/Monday, supporting dry and breezy downslope conditions along the lee of the Southern Rockies. Locally Elevated surface winds/RH may develop across portions of northeast New Mexico into southeast Colorado and western portions of the Texas and Oklahoma Panhandles by afternoon. However, locally Elevated meteorological conditions atop poorly receptive fuels preclude fire weather highlights this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sun Jan 8 18:40:02 UTC 2023.

No Mesoscale Discussions are in effect as of Sun Jan 8 18:40:02 UTC 2023.