• SPC Jun 20, 2019 0600 UTC Day 2 Convective Outlook
    on June 20, 2019 at 6:03 am

    SPC 0600Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Thu Jun 20 2019 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS...MIDDLE/LOWER MISSOURI RIVER VALLEY...AND NORTHEASTERN COLORADO.... ...SUMMARY... Severe thunderstorms are possible Friday across portions of the northern Plains, middle/lower Missouri River Valley, and northeastern Colorado. ...Northern/Central Plains eastward/southeastward into the Lower OH Valley... A very moist and strongly unstable air mass will be in place from eastern portions of the Plains into the lower OH Valley on Friday However, early period thunderstorms may have a large influence on the overall convective evolution, leading to moderate forecast uncertainty. Surface pattern early Friday morning will likely be characterized by a low over southeast MT/western SD with a trough extending to another low over western KS. A warm front is expected to arc northeastward from this western KS low to the KS/NE border and then southeastward across central MO. Storms may be ongoing north of this front across NE, although model consensus regarding the coverage and strength of these storms is poor. Presence of strong instability coupled with an eastward-shifting low-level jet could provide the ingredients needed for organization of any ongoing storms, with the warm front then providing a favored corridor for forward propagation. Confidence in this scenario is currently low, but if it materializes a corridor of damaging wind gusts is possible from northern/central MO into southern IL. The warm front is expected to progress northward as very moist air advects northward into the MO Valley. By late Friday afternoon, 70 degree dewpoints will likely be as far north as central IA and the NE/SD border. Very steep lapse rates (i.e. 9 deg C per km from 700 to 500 mb) associated with an well-developed EML atop this abundant low-level moisture will result in extreme buoyancy but also substantial convective inhibition. Large-scale forcing for ascent will be nebulous and slightly rising heights are anticipated, leading to some uncertainty as to whether or not the convective inhibition can be overcome and the resulting storm coverage. That being said, any storms that do develop should have strong updrafts capable of large hail. If a surface-based storm develops, backed surface winds along the warm front support enough low-level shear for a tornado or two. A somewhat separate regime exits across the eastern Dakotas, where convergence along the surface trough arcing from the western ND low to the KS low will likely result in scattered thunderstorm development. A few severe storms are anticipated, with hail as the primary threat. A tornado or two is also possible. ...Northeastern CO.. Post-frontal upslope regime is expected across northeastern CO on Friday, with enough low-level moisture and vertical shear to support severe thunderstorms. Primary severe threat is large hail, some of which could exceed 2" in diameter. Denver cyclonic convergence zone could also contribute to a few tornadoes. ...TX Panhandle/Far Western OK into the TX Big Bend... Temperatures will likely reach the upper 90s/low 100s along the dryline Friday afternoon, helping to overcome any convective inhibition. Resulting high-based thunderstorms will have the potential to produce strong wind gusts and isolated hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Mosier.. 06/20/2019 Read mor […]

  • SPC Jun 20, 2019 0600 UTC Day 1 Convective Outlook
    on June 20, 2019 at 6:02 am

    SPC 1200Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu Jun 20 2019 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CAROLINAS AND SOUTHERN VIRGINIA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY AND CENTRAL HIGH PLAINS... ...SUMMARY... Thunderstorms associated with damaging wind gusts and hail are likely today across parts of the Carolinas into the Middle Atlantic and Southeast. Isolated severe storms may also develop across parts of the Great Plains and Mid Missouri Valley. ...Eastern States... An upper-level trough will move eastward from the Ohio and Tennessee Valleys across the Southern and Central Appalachians into the Carolinas today. Ahead of the trough, a moist airmass will be in place from Georgia northeastward across the Carolinas into the Mid-Atlantic with surface dewpoints in the upper 60s and lower 70s F. In response, a large corridor of moderate instability is forecast to develop from the southern Appalachian foothills eastward to the Atlantic coast. Thunderstorms appear likely to initiate and organize just ahead of the shortwave trough in the southern Appalachians around midday with this activity moving eastward into the foothills during the afternoon. Forecast soundings in the foothills in northwestern South Carolina and west-central North Carolina at 21Z show MLCAPE values reaching 2,000 J/kg with 0-6 km shear of 30-35 kt. This combined with veered southwesterly winds at the surface and westerly flow in the low to mid-levels will be favorable for quasi-linear development. As low-level lapse rates become steep in the afternoon, conditions will become favorable for wind damage along the leading edge of an MCS moving eastward away from the southern Appalachians. For this reason, will upgrade to Enhanced risk for wind damage across parts of northern South Carolina, North Carolina and southern Virginia. Isolated large hail will also be possible with the stronger parts of the linear MCS. Further north into the Mid-Atlantic, instability is not forecast to be quite as strong as across the Carolinas. For that reason, the wind damage threat is expected to remain more isolated and will depend upon which areas destabilize the most. Wind damage would be the primary threat across the Mid-Atlantic this afternoon. ...Mid-Missouri Valley... Westerly mid-level flow will be in place in the central U.S. today as a shortwave ridge develops across the central and northern Plains. Beneath the ridge, an axis of moderate to strong instability is forecast to develop ahead of a cold front from Kansas northward into the mid Missouri Valley. Convection appears likely to initiate along the front with thunderstorms moving eastward across parts of eastern Nebraska and western Iowa during the late afternoon. Forecast soundings at 21Z for Omaha, Nebraska and Kansas City, Missouri show MLCAPE reaching 2,500 J/kg and have strong deep-layer shear profiles. 0-6 km shear is forecast to be around 55 kt at both locations suggesting that supercells will be the likely storm mode. Convective coverage should remain relatively isolated due to a weak cap but any cells that can initiate and mature should have severe potential. The strong instability combined with steep low to mid-level lapse rates would be favorable for wind damage and large hail. A brief tornado would also be possible with supercells mainly during the early evening as low-level flow increases across the region. ...Central High Plains... Mid-level flow is forecast to become west-southwesterly today across the central High Plains in the wake of a developing upper-level ridge in the mid Missouri Valley. At the surface, backed east-southeasterly flow will be in place which will reinforce an axis of moisture and instability from southern Kansas extending northwestward into northeastern Colorado and western Nebraska. As surface temperatures warm, convection will initiate in the higher terrain of northeastern Colorado and spread eastward into the central High Plains this afternoon. Steep low to mid-level lapse rates and moderate to strong deep-layer shear, evident on forecast soundings, will be favorable for severe storms. Dry air in the low-levels may contribute to downburst potential but isolated large hail will be possible especially if a supercell can develop. ..Broyles/Squitieri.. 06/20/2019 Read mor […]

  • SPC Severe Thunderstorm Watch 407 Status Reports
    on June 20, 2019 at 5:52 am

    WW 0407 Status Updates STATUS REPORT ON WW 407 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SE LFK TO 25 NNW LFK TO 10 WSW GGG TO 10 ESE SHV TO 35 ENE SHV TO 15 WSW ELD. ..GLEASON..06/20/19 ATTN...WFO...SHV...FWD...HGX... STATUS REPORT FOR WS 407 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC013-015-017-021-027-031-043-049-059-061-069-073-081-085-111- 119-127-200640- LA . LOUISIANA PARISHES INCLUDED ARE BIENVILLE BOSSIER CADDO CALDWELL CLAIBORNE DE SOTO GRANT JACKSON LA SALLE LINCOLN NATCHITOCHES OUACHITA RED RIVER SABINE UNION WEBSTER WINN TXC005-073-347-365-401-403-405-419-200640- TX . TEXAS COUNTIES INCLUDED ARE ANGELINA CHEROKEE NACOGDOCHES PANOLA RUSK SABINE SAN AUGUSTINE SHELBY Read mor […]

  • SPC Severe Thunderstorm Watch 407
    on June 20, 2019 at 5:52 am

    WW 407 SEVERE TSTM LA TX 200350Z - 201100Z URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 407 NWS Storm Prediction Center Norman OK 1050 PM CDT Wed Jun 19 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Louisiana East Texas * Effective this Wednesday night and Thursday morning from 1050 PM until 600 AM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Clusters and bands of thunderstorms should move across the watch area from the west and northwest, offering mainly damaging winds and sporadic large hail. A tornado cannot be ruled out. The severe thunderstorm watch area is approximately along and 45 statute miles either side of a line from 35 miles west northwest of College Station TX to 55 miles northeast of Natchitoches LA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 401...WW 403...WW 405...WW 406... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28035. ...Edwards Read mor […]

  • SPC Severe Thunderstorm Watch 406 Status Reports
    on June 20, 2019 at 5:49 am

    WW 0406 Status Updates STATUS REPORT ON WW 406 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 W GWO TO 45 E GWO TO 35 WNW CBM TO 20 W TUP TO 5 NW DYR. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1152 ..GLEASON..06/20/19 ATTN...WFO...BMX...HUN...MEG...JAN...OHX... STATUS REPORT FOR WS 406 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC007-009-021-033-043-057-059-063-065-073-075-077-079-083-089- 093-095-103-105-107-115-117-119-125-127-133-200640- AL . ALABAMA COUNTIES INCLUDED ARE BIBB BLOUNT CHILTON COLBERT CULLMAN FAYETTE FRANKLIN GREENE HALE JEFFERSON LAMAR LAUDERDALE LAWRENCE LIMESTONE MADISON MARION MARSHALL MORGAN PERRY PICKENS ST. CLAIR SHELBY SUMTER TUSCALOOSA WALKER WINSTON MSC003-007-009-015-017-019-025-051-057-069-079-081-087-089-095- 099-103-105-115-117-139-141-145-159-163-200640- MS . MISSISSIPPI COUNTIES INCLUDED ARE Read mor […]

  • SPC Severe Thunderstorm Watch 406
    on June 20, 2019 at 5:49 am

    WW 406 SEVERE TSTM AL AR MS TN 200320Z - 201100Z URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 406 NWS Storm Prediction Center Norman OK 1020 PM CDT Wed Jun 19 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern and central Alabama Northeastern Arkansas Central and northern Mississippi Southern middle and southwestern Tennessee * Effective this Wednesday night and Thursday morning from 1020 PM until 600 AM CDT. * Primary threats include... Widespread damaging winds likely with isolated significant gusts to 80 mph possible Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...A well-organized cluster and separate bow echo initially over eastern Arkansas, each with a well-developed wind signature and history of severe gusts, will proceed into and across the watch area. These systems could merge as well. Severe thunderstorm wind will remain the main threat, though an embedded tornado or two also is possible. The severe thunderstorm watch area is approximately along and 95 statute miles north and south of a line from 45 miles north northwest of Greenwood MS to 45 miles northeast of Birmingham AL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 401...WW 402...WW 403...WW 405... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27050. ...Edwards Read mor […]

  • SPC Severe Thunderstorm Watch 405 Status Reports
    on June 20, 2019 at 5:46 am

    WW 0405 Status Updates STATUS REPORT ON WW 405 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 ENE ELD TO 20 SW GWO. ..GLEASON..06/20/19 ATTN...WFO...LZK...JAN...MEG...SHV... STATUS REPORT FOR WS 405 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC003-017-200640- AR . ARKANSAS COUNTIES INCLUDED ARE ASHLEY CHICOT LAC035-041-065-067-083-107-123-200640- LA . LOUISIANA PARISHES INCLUDED ARE EAST CARROLL FRANKLIN MADISON MOREHOUSE RICHLAND TENSAS WEST CARROLL MSC053-055-125-151-200640- MS . MISSISSIPPI COUNTIES INCLUDED ARE HUMPHREYS ISSAQUENA SHARKEY WASHINGTON Read mor […]

  • SPC Severe Thunderstorm Watch 405
    on June 20, 2019 at 5:46 am

    WW 405 SEVERE TSTM AR LA MS 200140Z - 200900Z URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 405 NWS Storm Prediction Center Norman OK 840 PM CDT Wed Jun 19 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and eastern Arkansas Northern Louisiana Northwestern Mississippi * Effective this Wednesday night and Thursday morning from 840 PM until 400 AM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Clusters of severe thunderstorms are expected to move across the region this evening and tonight from the eastern parts of tornado watch 401, offering mainly hail and wind threats. However, a tornado cannot be ruled out. The severe thunderstorm watch area is approximately along and 65 statute miles east and west of a line from 50 miles north northeast of Little Rock AR to 60 miles south southwest of Greenville MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 400...WW 401...WW 402...WW 403...WW 404... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27030. ...Edwards Read mor […]

  • SPC Severe Thunderstorm Watch 403 Status Reports
    on June 20, 2019 at 5:43 am

    WW 0403 Status Updates STATUS REPORT ON WW 403 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NNE TYS TO 45 NE TYS. WW 403 WILL BE ALLOWED TO EXPIRE AT 200600Z. ..GLEASON..06/20/19 ATTN...WFO...LMK...JKL...MRX...OHX... STATUS REPORT FOR WS 403 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TNC025-200600- TN . TENNESSEE COUNTIES INCLUDED ARE CLAIBORNE THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read mor […]

  • SPC MD 1152
    on June 20, 2019 at 5:38 am

    MD 1152 CONCERNING SEVERE THUNDERSTORM WATCH 406... FOR PORTIOSN OF WESTERN/MIDDLE TN Mesoscale Discussion 1152 NWS Storm Prediction Center Norman OK 1237 AM CDT Thu Jun 20 2019 Areas affected...Portiosn of western/middle TN Concerning...Severe Thunderstorm Watch 406... Valid 200537Z - 200630Z The severe weather threat for Severe Thunderstorm Watch 406 continues. SUMMARY...Damaging winds should continue to spread eastward across western and middle TN over the next couple of hours. A small northward extension in area may be needed for Severe Thunderstorm Watch 406. DISCUSSION...A small bowing complex that earlier produced a 58 kt wind gust at the Memphis airport will continue moving eastward around 40-45 kt across parts of western/middle TN early this morning. The airmass downstream of this convection remains at least weakly unstable, and storm organization will probably be maintained for the next hour or two with a strengthening southwesterly low-level jet. Strong to damaging winds remain the primary threat, with velocity data from KNQA showing 50-60+ kt outbound wind signature northeast of Memphis. Part of this line will approach the northern edge of Severe Thunderstorm Watch 406 in the next hour, and a small extension northward in area may be warranted if current radar trends continue. ..Gleason.. 06/20/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OHX...MEG... LAT...LON 35048948 35718944 35888931 35878772 35708686 35168688 35038696 35058798 35048948 Read mor […]