Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0653 AM CST Thu Feb 24 2022 Valid 241300Z - 251200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are possible today and tonight from the western Gulf Coast across the lower/mid Mississippi and Ohio Valley regions. ...Synopsis... Positively tilted, large-scale troughing will persist over the western CONUS, with a series of lower-end synoptic to small shortwave troughs traversing the associated cyclonic flow. The leading perturbation -- evident in moisture-channel imagery from central WY across western CO, AZ and northern Baja -- should eject northeastward to the central Plains and southern High Plains by 00Z. By the end of the period, this feature should reach Lower MI and the OH/IN border area, in substantially deamplified form. An upstream shortwave trough -- now over southeastern BC and WA -- will dig southeastward across the interior Northwest to the northern Great Basin and southern ID today, before merging with an initially separate perturbation now over east-central SK tonight. The resultant trough should be positioned from ND across western WY to central NV by 12Z tomorrow. At the surface, 11Z analysis showed a mostly quasistationary frontal zone from southern NC to a weak, frontal-wave low over eastern TN, southwestward across central AL and southern portions of MS/LA. With the oblique approach of the ejecting western trough, a separate, discrete low should develop along a retreated version of the frontal wave by 00Z, most likely over western/central KY near the Ohio River. By that time, the trailing boundary should extend across western TN, central MS, southwestern LA, and the northwestern Gulf to south of BRO, again becoming a cold front. By 12Z, the low should deepen and move to northwestern PA, with cold front across eastern WV, the Appalachians of VA/NC/GA, eastern/southern AL, to near the Mississippi River mouth, and slightly farther southeastward over the northwestern Gulf than 12 hours prior. ...Southeastern LA to northwestern AL this evening/overnight... Isolated to widely scattered thunderstorms are possible on either side of the front through the period, with postfrontal convection dominant before 00Z, and frontal/warm-sector activity more likely this evening through overnight. The latter may access a favorably moist warm sector, characterized by surface dew points in the mid/upper 60s F. Deep-layer lapse rates will be weak: 1. In the low levels, without the benefit of strong diurnal heating, and 2. In midlevels, with neutral to stable thermal layers (basal EML remnants that remain evident in upstream 12Z LIX/SHV/JAN/LCH/CRP RAOBs) lingering in forecast soundings until very near to after cold-frontal passage. DCVA-related large-scale ascent with the ejecting mid/upper trough will remain well behind the surface front. Still, warm advection may be sufficient to lift/cool the remnant EML base enough to permit deeper convection near the front. This regime is possible amidst 35-45-kt effective-shear magnitudes, and hodograph somewhat enlarged on the eastern rim of a departing LLJ whose axis also should be behind the surface cold front. An isolated, briefly strong thunderstorm may mature before being undercut by the front, while embedded within (and training along the axis of) a southwest/ northeast-aligned convective band. However, given a marginal (at best) kinematic/thermodynamic parameter space expected, and the anafrontal regime, severe potential remains too conditional/ uncertain to reintroduce a risk area at this time. ..Edwards/Gleason.. 02/24/2022 Read more

MD 0182 CONCERNING FREEZING RAIN FOR PORTIONS OF CENTRAL/NORTHEAST TX INTO EASTERN OK AND MUCH OF CENTRAL/NORTHERN AR
Mesoscale Discussion 0182 NWS Storm Prediction Center Norman OK 0416 AM CST Thu Feb 24 2022 Areas affected...Portions of central/northeast TX into eastern OK and much of central/northern AR Concerning...Freezing rain Valid 241016Z - 241615Z SUMMARY...Another round of freezing rain will develop across central/northeast Texas and spread northeastward this morning. Freezing-rain rates around 0.05 inch per 3 hours may occur, with locally higher rates possible. DISCUSSION...Recent radar imagery across central into northeast TX shows a gradual filling of light reflectivities, with multiple recent reports of light freezing drizzle and freezing rain. A synoptic-scale upper trough over the Rockies and Southwest will continue to eject northeastward, while a low-amplitude shortwave trough over northern Mexico moves northeastward over TX this morning. Modest ascent associated with this latter feature, and warm advection attendant to a 30-40-kt southwesterly low-level jet, will likely aid in a gradual increase of precipitation coverage across central/northeast TX over the next few hours. 10Z surface observations indicate the sub-freezing temperatures are present where most of this light precipitation is falling. With a substantial low-level warm nose also over this region per latest mesoanalysis estimates and NAM/RAP forecast soundings, freezing rain is expected to be the dominant precipitation type. As the showery precipitation gradually expands in coverage/intensity and develops northeastward, freezing-rain rates around 0.05 inch per 3 hours may occur. This swath of generally light freezing rain is expected to overspread parts of eastern OK and much of central/northern AR through 16Z (10 AM CST), where surface temperatures remain below freezing. Locally higher rates will be possible within the heavier precipitation cores. Some elevated convection may be capable of producing isolated lighting flashes, as about 250-500 J/kg of MUCAPE exists over much of this region. ..Gleason.. 02/24/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SHV...TSA...FWD...OUN... LAT...LON 30949778 31689829 32009834 33269751 34439652 35589537 36079413 36289309 36429189 36429127 36029106 35489111 34949164 34369265 34299333 34049438 33689473 32799516 31809585 31139680 30949778 Read more

No watches are valid as of Wed Feb 23 14:48:01 UTC 2022.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 AM CST Wed Feb 23 2022 Valid 231300Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today or tonight. ...Synopsis/Discussion... In mid/upper levels, deep troughing predominates over the western CONUS, with intermittently closed cyclonic flow centered over NV. The synoptic trough will lose some amplitude through the period, but remain strong and well-defined, as it moves eastward to a position at 12Z tomorrow from eastern WY to central CO, the Four Corners area, and southwestern AZ/northern Baja. Marginal low/middle-level moisture, favorable large-scale DCVA/lift, related steep midlevel lapse rates, and resulting weak buoyancy will promote isolated thunderstorm potential in a corridor of cyclonic flow from southern CA to the Four Corners. Downstream southwesterly flow will prevail over the central CONUS, gradually becoming westerly with eastward extent into the Atlantic Coast States. A weak/embedded shortwave trough -- initially located over parts of northeast TX to southeastern NM and far west TX -- will eject northeastward rapidly, reaching parts of KY by 00Z, and NJ by 12Z in a much-weakened condition. Until then, associated low-level warm/moist advection to its east and south -- elevated atop an intense post-frontal cold/stable layer where north of the frontal zone described below -- will support sporadic thunder. This will include bouts of lightning accompanying sleet and freezing rain from an ongoing/expanding episode over north-central/northwest TX and southern OK, across more of OK/AR through afternoon. Forecast soundings suggest 200-700 J/kg MUCAPE may develop over the cold- frontal layer, and isolated subsevere hail may occur in the most intense cores already yielding sleet and freezing rain. At the surface, a cold front was drawn at 11Z from the Adirondacks across central PA, southwestern VA, eastern TN, northwestern AL, southwestern MS, to near GLS and LRD, across northern Coahuila and northeastern Chihuahua, to central/north-central NM. By 00Z, this boundary should extend from the Delmarva Peninsula to central/ southwestern GA, southern portions of AL/MS/LA, and just offshore from most of the TX Coast, to near BRO. By 12Z, the front should move little from LA southwestward while retreating inland across central and perhaps northern parts of MS/AL/GA. ..Edwards/Gleason.. 02/23/2022 Read more

MD 0176 CONCERNING WINTER MIXED PRECIPITATION FOR PORTIONS OF WEST/NORTH TX INTO SOUTHERN/CENTRAL/EASTERN OK
Mesoscale Discussion 0176 NWS Storm Prediction Center Norman OK 0358 AM CST Wed Feb 23 2022 Areas affected...Portions of west/north TX into southern/central/eastern OK Concerning...Winter mixed precipitation Valid 230958Z - 231600Z SUMMARY...A mix of sleet and freezing rain will spread quickly northeastward this morning. Convective elements with embedded lightning may produce enhanced sleet accumulation rates. DISCUSSION...A subtle shortwave trough ejecting northeastward from northern Mexico and far west TX across the southern Plains is encouraging low-level warm and moist air advection atop a deep sub-freezing, near-surface layer across much of central/north TX this morning. A rash of elevated convection with numerous lightning flashes has developed over the past couple of hours on the leading edge of the low-level moisture return across parts of west into north-central TX, as large-scale ascent preceding the shortwave trough overspreads this region. 00Z observed soundings from OUN/FWD and latest NAM/RAP forecast soundings show a substantial warm nose generally centered in the 850-700-mb layer across much of north TX into southern/central/eastern OK that should completely melt frozen hydrometeors aloft. Consensus of latest guidance continues to suggest that the depth of the sub-freezing layer from the surface to around 850 mb will likely be cold/deep enough to support complete refreezing of the melted hydrometeors. Therefore, sleet should be the dominant precipitation type. On the southern fringes of the expanding precipitation plume across north-central TX, including the Metroplex, a mix of freezing rain and sleet appears possible as the near-surface sub-freezing layer should not be as quite deep as locations farther north. Ongoing elevated thunderstorms will likely offer potential for greater sleet accumulation rates of 0.5 inch to locally 1 inch per hour as they pass over a given location. Current expectations are for this sleet-producing convection to spread quickly northeastward this morning across much of north TX over the next couple of hours, and into parts of southern/central/eastern OK in the 12-16Z time frame (6-10 AM CST). ..Gleason.. 02/23/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SHV...TSA...FWD...OUN...SJT...LUB...MAF... LAT...LON 32579775 32629856 32679914 32190028 31850069 31990120 32310190 33240191 33710121 35319863 35969714 36239597 35899459 35279446 34459452 33419534 32549653 32579775 Read more

MD 0170 CONCERNING TORNADO WATCH 25... FOR SOUTH-CENTRAL KY...NORTHERN MIDDLE TN
Mesoscale Discussion 0170 NWS Storm Prediction Center Norman OK 0926 AM CST Tue Feb 22 2022 Areas affected...South-Central KY...Northern Middle TN Concerning...Tornado Watch 25... Valid 221526Z - 221730Z The severe weather threat for Tornado Watch 25 continues. SUMMARY...Isolated damaging wind gusts may occur across portions of south-central KY and northern Middle TN. DISCUSSION...A line of thunderstorms currently extends from far south-central KY southwestward through northern middle TN and back into western TN. The northern portion of this line has shown a trend for a bit more forward motion as updrafts/downdrafts within the line briefly intensify. This has lead to a few inflections within the line, indicative of slightly stronger winds possibly reaching the surface. Storm motion is already fast (i.e. around 50-55 kt) so any convective augmentation could lead to isolated severe gusts reaching the surface. Even so, stable boundary layer sampled by the 12Z BNA is likely limiting the overall realization of stronger winds at the surface. The overall trends of updrafts intensifying briefly within the line may continue, but the low-level stability will likely persist, limiting the overall severe potential with eastern extent. ..Mosier/Hart.. 02/22/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JKL...LMK...OHX...PAH... LAT...LON 36608735 37008648 37178564 36938501 36128534 35778676 35898784 36608735 Read more

MD 0169 CONCERNING FREEZING RAIN FOR PORTIONS OF NORTHERN LOWER MI
Mesoscale Discussion 0169 NWS Storm Prediction Center Norman OK 0920 AM CST Tue Feb 22 2022 Areas affected...Portions of northern Lower MI Concerning...Freezing rain Valid 221520Z - 221915Z SUMMARY...Freezing rain, mixed at times with sleet and snow, is expected to increase in coverage through early afternoon with significant ice accumulation possible. DISCUSSION...A nearly stationary front extended east-west across southern Lower MI at 15z, with temperatures north of the front mostly in the 15 - 25 deg F range. Regional radar composite shows precipitation expanding in areal coverage southwest of the discussion area as increasing large-scale ascent associated with a mid-level impulse approaches the area. Latest RAP forecast soundings and 12z HREF guidance depict a favorable thermal profile for freezing rain as the primary precipitation type given a prominent warm nose located above a deep sub-freezing surface layer. Although sleet and snow may mix in at times, freezing rain should remain the primary concern in the short term with significant ice accumulation possible. ..Bunting.. 02/22/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...APX...GRR... LAT...LON 44688621 44888532 44898459 44898392 44758322 44508279 44028281 43898302 43738406 43668471 43578598 43598629 43808658 44238667 44688621 Read more

WW 0025 Status Updates
STATUS REPORT ON WW 25 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 E LIT TO 60 SSE BVX TO 35 ESE JBR TO 5 ENE DYR TO 45 NNE MKL TO 50 SSE PAH TO 30 WSW HOP TO 30 WNW HOP TO 30 E PAH TO 45 NE PAH TO 25 WSW EVV. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0168 ..GLEASON..02/22/22 ATTN...WFO...MEG...LZK...PAH...OHX... STATUS REPORT FOR WT 25 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC035-037-093-123-221440- AR . ARKANSAS COUNTIES INCLUDED ARE CRITTENDEN CROSS MISSISSIPPI ST. FRANCIS KYC033-047-055-059-101-107-143-149-177-219-221-225-233-221440- KY . KENTUCKY COUNTIES INCLUDED ARE CALDWELL CHRISTIAN CRITTENDEN DAVIESS HENDERSON HOPKINS LYON MCLEAN MUHLENBERG TODD TRIGG UNION WEBSTER Read more

WW 25 TORNADO AR IL KY MO TN 220950Z - 221700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 25 NWS Storm Prediction Center Norman OK 350 AM CST Tue Feb 22 2022 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and northeastern Arkansas Extreme southern Illinois Western Kentucky Southeastern Missouri Western and a small part of middle Tennessee * Effective this Tuesday morning from 350 AM until 1100 AM CST. * Primary threats include... A couple tornadoes possible Scattered damaging winds likely with isolated significant gusts to 75 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A band of severe thunderstorms should move rapidly east-northeastward through the watch area this morning, offering mainly damaging winds, and the threat for a couple embedded tornadoes. Isolated supercell formation east of the band also may occur, but is more uncertain. The tornado watch area is approximately along and 65 statute miles north and south of a line from 50 miles north northwest of Little Rock AR to 30 miles northeast of Fort Campbell KY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...CONTINUE...WW 24... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 24050. ...Edwards Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0654 AM CST Tue Feb 22 2022 Valid 221300Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH...LOWER OHIO VALLEY...TENNESSEE VALLEY...MISSISSIPPI...AND ALABAMA.... ...SUMMARY... Damaging thunderstorm gusts, a few tornadoes, and isolated severe hail are possible today from Arkansas to the Mid-South and lower Ohio Valley, and this evening over parts of Mississippi, Alabama and Tennessee. ...Synopsis... In mid/upper levels, mean troughing and extensive cyclonic flow will be maintained over the West through the period, but with an embedded pattern shift toward split flow. This will occur as a strong, cold shortwave trough -- evident in moisture-channel imagery over OR and northern CA -- pivots southeastward and evolves into a closed cyclone tonight over NV. In response to these developments, a broad fetch of southwesterlies aloft will be maintained from the southern/central Rockies across the southern/central Plains, Midwest, Great Lakes and Southeast. An embedded shortwave trough -- initially located from southern KS to west TX -- will move northeastward and weaken. This feature should stretch into a remnant vorticity banner from the Ozarks to north-central and southwest TX by 00Z, weakening further while aligning from the Ohio Valley back to the Red River by 12Z tomorrow. At the surface, 11Z analysis showed an intense cold front extending from an elongated area of low pressure over western IL to central MO, southwestward across eastern OK, the TX South Plains, and extreme east-central/northeastern NM. By 00Z, the low should consolidate and reach eastern Lower MI, with cold front over western OH, western TN, northern LA, south-central/southwest TX, and east- central/north-central NM. By the end of the period, the front should reach eastern NY, western VA, northwestern GA, southwestern MS, deep south to far west TX across some adjoining portions of MX, and central NM. ...AR to Ohio Valley today... A belt of strong-severe convection, with a fast-moving, leading squall line, is ongoing across portions of the Mid-South. This activity will proceed northeastward to parts of the Ohio Valley, western/mid TN, and western/central KY this morning, encountering an environment of weak but adequate low/middle-level instability, surface dew points in the mid 50s to low 60s F, long hodographs and low-level shear vectors, and strong deep shear. Damaging gusts, a few tornadoes, and isolated, marginally severe hail are possible. Trailing convection in the associated belt of prefrontal/low-level lift also may pose a severe threat. Refer to SPC tornado watch 25 and related mesoscale discussions for near-term details on the morning scenario. As the associated hodograph-enhancing LLJ shifts rapidly northeastward toward the central/northern Appalachians today, two processes are expected: 1. The initial MCS will outrun a narrowing surface-based warm sector in its path, encountering progressively weaker inflow-layer buoyancy, and weaken across northeastern fringes of the outlook area. 2. Low-level shear will decrease substantially, but remain at least marginally favorable for any trailing/lingering convection in the plume, that can access diurnally heated and relatively undisturbed surface-based effective-inflow parcels. However, in the absence of substantial large-scale lift/support, and with flow aloft parallel to a sagging outflow boundary, messy/training convection with a slightly anafrontal boundary regime will make the severe threat more conditional and marginal into mid/late afternoon. ...MS/AL/TN this evening... Some rejuvenation of a LLJ-associated plume of low-level convergence and convective potential is expected this evening, as the boundary layer decouples, but before it cools/stabilizes too much to support surface-based thunderstorms. Despite lack of substantial mid/upper- level forcing for ascent, warm advection, moisture transport and related favorable low-level theta-e will support thunderstorm development, amid weak CINH and lingering favorable deep shear. Forecast soundings suggest 500-1000 J/kg MLCAPE will be possible in a triangular swath bounded on the east by more-stable, recycled continental/polar air, the cold front and EML-related MLCINH on the northwest/west, and weaker lift/greater CINH to the south. Though not as large as with the morning regime farther north, well-shaped hodographs and 45-55-kt effective-shear magnitudes will support supercell potential, as well as embedded small bow/LEWP formations. Damaging gusts and a couple tornadoes may occur before lift and instability weaken overnight, ramping down the severe threat. ..Edwards/Gleason.. 02/22/2022 Read more

No watches are valid as of Fri Feb 18 14:24:02 UTC 2022.

No Mesoscale Discussions are in effect as of Fri Feb 18 14:24:02 UTC 2022.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Fri Feb 18 2022 Valid 181300Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible today from the coastal Carolinas to northern Florida. ...Synopsis/Discussion... In mid/upper levels, mean troughing will persist from the Canadian Arctic Islands and Hudson Bay to the east-central CONUS through the period. Initially, a positively tilted trough and associated lengthy vorticity banner were apparent from southern ON across parts of the Ohio Valley to the Ozarks, northwest TX and northwestern MX. This feature will elongate further and weaken, with its northern portion moving offshore from New England and the Mid-Atlantic, while the southern part slowly loses definition within a broad cyclonic- flow field. A trailing/northern-stream shortwave trough -- evident in moisture-channel imagery from southern MB to northwestern MN -- will reach southeastern ON and southern Lower MI by 12Z tomorrow. At the surface, 11Z analysis showed a cold front across portions of New England, the near-coastal Mid-Atlantic, central VA, western SC, the west-central FL Panhandle, and the north-central/west-central Gulf. This front will move offshore from all but northern FL by 03Z, then southeastward to south-central FL by 12Z. Isolated thunderstorms will remain possible in a narrow band of mostly prefrontal convection now located from coastal NC to the eastern FL Panhandle. With nearly front-parallel flow aloft, poor mid/upper- level lapse rates, weakening large-scale to frontal-scale lift, and veering prefrontal surface winds with time, severe potential appears minimal, despite lingering strong flow aloft. In the continental/polar air mass behind that cold front, another low (associated with the MB/MN perturbation aloft) was drawn over extreme southern MB, with cold front across northern parts of ND/MT. The latter front is forecast to sweep southward/southeastward over the Upper Midwest, Great Lakes and lower/middle Missouri Valley, to near the Ohio Valley by the end of the period. Dry/stable low-level conditions in the prefrontal sector will prevent associated thunderstorm development. ..Edwards/Gleason.. 02/18/2022 Read more

No watches are valid as of Thu Feb 17 15:31:02 UTC 2022.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Thu Feb 17 2022 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING ACROSS PARTS OF THE MID-SOUTH AND TN VALLEY... ...SUMMARY... Severe thunderstorms are expected across portions of the Mid-South, Tennessee Valley, and the lower Ohio Valley, mainly later today into this evening. Damaging winds and a strong tornado or two will be possible. ...Mid South/TN Valley into the OH Valley through this evening... A midlevel shortwave trough over the Red River of TX/OK this morning will eject northeastward to the OH River by this evening, as an associated surface cyclone likewise develops northeastward from southeast OK this morning to southern OH this evening. In advance of a cold front trailing the surface cyclone, continued northward moisture transport will result in mid-upper 60s boundary-layer dewpoints reaching the Mid South this afternoon, and low-mid 60s into middle TN and AL by this evening/early tonight. Surface heating in cloud breaks and the increasing low-level moisture will result in MLCAPE of 500-750 J/kg in advance of the cold front this afternoon, especially near and east of the MS River. Thus far, overnight and morning convection across north TX/OK/western AR has not been particularly intense/organized. There is substantial uncertainty regarding how quickly any severe/tornado threat will increase during the day across AR, given widespread clouds and the saturated profile noted in the 12z LZK sounding. The primary threat for supercells in the warm sector may be delayed until mid afternoon across the Mid South, with broken bands of storms/embedded supercells along and ahead of the front spreading eastward into AL/Middle TN this evening. Despite the rather modest buoyancy and lapse rates expected, very strong low-level shear (curved hodographs with 300-500 m2/s2 0-1 km SRH) and effective bulk shear of 50-60 kt will favor supercells, and a storm or two could produce a strong tornado (in addition to damaging winds) this afternoon into this evening across northeast MS/northwest AL and adjacent areas of TN. Otherwise, a shallow/forced band of convection will likely accompany the surface cyclone and trailing cold front just to the south. Buoyancy will remain weak close to the OH River and some low-level static stability could persist through the day. However, profiles will be sensitive to changes of only a few degrees (from the low to the mid 60s), such that there is still some potential for damaging winds and a line-embedded tornado or two as far north as the cyclone track through this evening. Overnight, the severe threat will diminish with northeastward and eastward extent as a result of minimal buoyancy and the stronger forcing for ascent no longer phasing with the remaining weakly unstable warm sector to the south. ..Thompson/Gleason.. 02/17/2022 Read more

MD 0140 CONCERNING WINTER MIXED PRECIPITATION FOR PORTIONS OF NORTHERN OK...SOUTHERN/EASTERN KS...MUCH OF MO...AND FAR WESTERN IL
Mesoscale Discussion 0140 NWS Storm Prediction Center Norman OK 0600 AM CST Thu Feb 17 2022 Areas affected...Portions of northern OK...southern/eastern KS...much of MO...and far western IL Concerning...Winter mixed precipitation Valid 171200Z - 171800Z SUMMARY...A wintry mix of freezing rain, sleet, and snow will spread northeastward this morning. Snowfall rates of 1-2 inches per hour appear likely. Blowing snow with reduced visibilities will also occur due to the strong winds. DISCUSSION...A mid-level shortwave trough ejecting over the southern/central Plains this morning and associated low-level frontogenesis/lift is supporting a large area of precipitation extending from parts of northern OK into KS and MO. At the surface, an arctic cold front will continue to move southward across the southern Plains, with sub-freezing temperatures occurring fairly quickly after its passage. Within the broad precipitation shield and north of the cold front, recent surface observations and mPING reports indicate a mix of wintry precipitation is ongoing. A fairly quick transition from freezing rain to sleet should occur behind the cold front, as low/mid-level temperatures will quickly cool with the approach of the shortwave trough. Moderate to locally heavy sleet may occur in a swath extending from parts of southeastern KS into southern/central MO based on consensus of short-term model guidance and observational trends. Where the low-level warm nose can erode more quickly, a band of moderate to heavy snow (already forming at 12Z) will further develop and subsequently spread northeastward through the morning. With strong lift occurring within the saturated dendritic growth zone, snowfall rates of 1-2 inches per hour appear likely within this band. The best potential for mainly snow and the greater snowfall rates should occur from parts of northern OK into south-central/east-central KS and western/central MO through midday. Due to an enhanced surface pressure gradient, strong/gusty winds will aid in blowing snow, which should reduce visibilities. ..Gleason.. 02/17/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILX...LSX...DVN...SGF...EAX...TSA...TOP...ICT... OUN...DDC... LAT...LON 35989893 35979938 36249958 36469960 36739953 37199895 38499692 39799386 40219246 40309186 40159102 39829026 39398996 38868995 38219049 37809098 37359166 37079240 36829324 36589489 36439689 36169811 35989893 Read more

No watches are valid as of Tue Feb 15 14:23:02 UTC 2022.

No Mesoscale Discussions are in effect as of Tue Feb 15 14:23:02 UTC 2022.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0634 AM CST Tue Feb 15 2022 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur late this afternoon into early tonight from parts of central Nevada toward the Coastal Range in southern California. ...Synopsis... A deep midlevel trough will progress southeastward over CA/NV and will reach the lower CO River valley by Wednesday morning. Cold midlevel temperatures and associated steep lapse rates will support the potential for low-topped convection and isolated lightning flashes both from east of the southern Sierra Nevada into northwest AZ this afternoon into early tonight, and across southern CA. Otherwise, air mass modification and the early stages of return flow are underway across the Gulf basin and FL Straits. However, the degree of moistening inland will be insufficient for deep convection until later in the D2 period across the southern Plains and south FL. ..Thompson.. 02/15/2022 Read more

No Mesoscale Discussions are in effect as of Mon Feb 14 14:50:01 UTC 2022.