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WW 0579 Status Updates
STATUS REPORT ON WW 579 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 ENE CKV TO 25 SE CKV TO 15 NW BNA TO 20 ESE BNA TO 45 W CSV TO 15 NW CSV TO 25 N CSV TO 40 N CSV TO 50 N CSV. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1729 ..COOK..08/13/19 ATTN...WFO...OHX...MRX...HUN... STATUS REPORT FOR WS 579 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TNC003-007-011-015-021-031-035-037-043-049-051-055-061-065-081- 085-099-101-103-105-107-115-117-119-121-123-127-129-135-139-143- 145-149-153-175-177-181-185-187-132340- TN . TENNESSEE COUNTIES INCLUDED ARE BEDFORD BLEDSOE BRADLEY CANNON CHEATHAM COFFEE CUMBERLAND DAVIDSON DICKSON FENTRESS FRANKLIN GILES GRUNDY HAMILTON HICKMAN HUMPHREYS LAWRENCE LEWIS LINCOLN LOUDON MCMINN MARION MARSHALL MAURY MEIGS MONROE MOORE MORGAN PERRY POLK RHEA ROANE RUTHERFORD SEQUATCHIE VAN BUREN WARREN WAYNE WHITE WILLIAMSON Read more

WW 579 SEVERE TSTM TN 131950Z - 140200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 579 NWS Storm Prediction Center Norman OK 250 PM CDT Tue Aug 13 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Middle and southeast Tennessee * Effective this Tuesday afternoon and evening from 250 PM until 900 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Scattered thunderstorms developing across middle Tennessee may intensify as they consolidate into an east-southeast moving cluster towards southeast Tennessee. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 50 miles south southwest of Clarksville TN to 25 miles east southeast of Crossville TN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 576...WW 577...WW 578... 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 29025. ...Grams Read more

MD 1730 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR CENTRAL AND SOUTHWEST KS...FAR EAST-CENTRAL CO
Mesoscale Discussion 1730 NWS Storm Prediction Center Norman OK 0522 PM CDT Tue Aug 13 2019 Areas affected...central and southwest KS...far east-central CO Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 132222Z - 132345Z Probability of Watch Issuance...80 percent SUMMARY...Storms will probably develop south-southeastward into west-central and southwest KS this evening. Severe gusts (60-75mph) and isolated large hail are the primary threats. DISCUSSION...Radar mosaic shows a couple of intense storm clusters near the Burlington, CO/Goodland KS vicinity and another farther northeast in between Colby, KS and McCook, NE. A considerable amount of outflow associated with the storms is becoming more spatially extensive with time. Surface analysis indicates temperatures in the upper 80s with middle 60s degrees F dewpoints south of the ongoing storms. Recent storm-scale model guidance suggests a continuation of storms through the evening as this activity moves to the south-southeast. The eastern periphery of steeper 700-500mb lapse rates (7.5 degrees C/km) is located over western KS with 8-9 degree C/km 0-3km lapse rates. Despite some slow cooling early this evening, mature cold pools and regenerative development will probably lead to storms moving towards the Garden City/Dodge City vicinity later this evening. The hail risk may focus over west-central KS before additional linear upscale growth favors mostly a risk for severe gusts. ..Smith/Edwards.. 08/13/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ICT...DDC...GLD...PUB... LAT...LON 38620270 39129909 38469849 37539902 37109983 37110131 38620270 Read more

MD 1729 CONCERNING SEVERE THUNDERSTORM WATCH 579... FOR MIDDLE AND EASTERN TENNESSEE
Mesoscale Discussion 1729 NWS Storm Prediction Center Norman OK 0509 PM CDT Tue Aug 13 2019 Areas affected...Middle and eastern Tennessee Concerning...Severe Thunderstorm Watch 579... Valid 132209Z - 132315Z The severe weather threat for Severe Thunderstorm Watch 579 continues. SUMMARY...The severe threat continues across WW 579. DISCUSSION...Scattered strong to severe thunderstorms continue across mainly northern and central portions of ongoing WW 579 at this time. These storms are loosely organized and in a marginally strong shear environment, though strong instability (3500-5000 J/kg MUCAPE) continues to support occasional wind-damage-producing downbursts with mostly outflow-dominant storms. Observations and short-term model guidance suggests that these storms should continue to gradually grow upscale over the next few hours, with the severe threat tapering off from north to south as overturning and maturing cold-pool processes continue. ..Cook.. 08/13/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MRX...JKL...FFC...LMK...OHX...HUN...MEG... LAT...LON 36038788 36318734 36648611 36648494 36258446 35628412 35118425 34938467 35058654 34988770 35178812 35488819 36038788 Read more

WW 0577 Status Updates
STATUS REPORT ON WW 577 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NNE AKO TO 10 N MCK. ..SMITH..08/13/19 ATTN...WFO...GLD...BOU...LBF... STATUS REPORT FOR WT 577 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC017-063-073-121-125-132240- CO . COLORADO COUNTIES INCLUDED ARE CHEYENNE KIT CARSON LINCOLN WASHINGTON YUMA KSC023-039-063-065-071-109-137-153-179-181-193-199-203-132240- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR GOVE GRAHAM GREELEY LOGAN NORTON RAWLINS SHERIDAN SHERMAN THOMAS WALLACE WICHITA NEC057-087-145-132240- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

WW 0576 Status Updates
STATUS REPORT ON WW 576 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SW GSP TO 20 S AVL TO 10 SSE HKY TO 30 SW GSO TO 30 ESE GSO TO 25 NNE RDU. ..COOK..08/13/19 ATTN...WFO...GSP...RAH...RNK...MRX... STATUS REPORT FOR WS 576 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC001-025-035-045-057-071-097-109-119-151-159-132240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALAMANCE CABARRUS CATAWBA CLEVELAND DAVIDSON GASTON IREDELL LINCOLN MECKLENBURG RANDOLPH ROWAN SCC021-045-083-091-132240- SC . SOUTH CAROLINA COUNTIES INCLUDED ARE CHEROKEE GREENVILLE SPARTANBURG YORK 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 more

WW 576 SEVERE TSTM GA NC SC TN VA 131725Z - 132300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 576 NWS Storm Prediction Center Norman OK 125 PM EDT Tue Aug 13 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Far northeast Georgia Western North Carolina Far northwest South Carolina Far eastern Tennessee Southwest Virginia * Effective this Tuesday afternoon and evening from 125 PM until 700 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible SUMMARY...A line of strong to locally severe storms across southwest Virginia and eastern Tennessee may intensify after it crosses the crest of the southern Appalachians, with additional clusters possibly developing downstream through the afternoon. The severe thunderstorm watch area is approximately along and 90 statute miles east and west of a line from 30 miles west southwest of Greenville SC to 60 miles northwest of Danville VA. 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27025. ...Grams Read more

WW 0578 Status Updates
STATUS REPORT ON WW 578 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ESE GSO TO 25 NNE RDU TO 15 NE RZZ TO 30 NE RZZ TO 15 SW RIC. ..COOK..08/13/19 ATTN...WFO...RAH...AKQ... STATUS REPORT FOR WS 578 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC007-037-051-063-065-069-073-077-083-085-091-093-101-105-123- 125-127-131-135-153-163-165-167-181-183-185-191-195-132240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ANSON CHATHAM CUMBERLAND DURHAM EDGECOMBE FRANKLIN GATES GRANVILLE HALIFAX HARNETT HERTFORD HOKE JOHNSTON LEE MONTGOMERY MOORE NASH NORTHAMPTON ORANGE RICHMOND SAMPSON SCOTLAND STANLY VANCE WAKE WARREN WAYNE WILSON VAC093-149-175-181-183-199-550-620-650-670-700-710-735-740-800- 810-132240- VA . VIRGINIA COUNTIES INCLUDED ARE ISLE OF WIGHT PRINCE GEORGE SOUTHAMPTON Read more

WW 0579 Status Updates
STATUS REPORT ON WW 579 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..COOK..08/13/19 ATTN...WFO...OHX...MRX...HUN... STATUS REPORT FOR WS 579 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TNC003-007-011-015-021-027-031-035-037-041-043-049-051-055-061- 065-081-085-087-099-101-103-105-107-111-115-117-119-121-123-127- 129-133-135-137-139-141-143-145-147-149-153-159-165-169-175-177- 181-185-187-189-132240- TN . TENNESSEE COUNTIES INCLUDED ARE BEDFORD BLEDSOE BRADLEY CANNON CHEATHAM CLAY COFFEE CUMBERLAND DAVIDSON DE KALB DICKSON FENTRESS FRANKLIN GILES GRUNDY HAMILTON HICKMAN HUMPHREYS JACKSON LAWRENCE LEWIS LINCOLN LOUDON MCMINN MACON MARION MARSHALL MAURY MEIGS MONROE MOORE MORGAN OVERTON PERRY PICKETT POLK PUTNAM RHEA ROANE ROBERTSON RUTHERFORD SEQUATCHIE SMITH SUMNER TROUSDALE VAN BUREN WARREN WAYNE WHITE WILLIAMSON WILSON Read more

August 12, 1545: Burning operation were completed at 1545, and the site is being monitored. August 12, 1200: At noon Monday, August 12, fire staff is burning four wood debris piles on two acres at Cheat Summit Fort in Randolph County. Smoke may be visible in the area.

WW 0578 Status Updates
STATUS REPORT ON WW 578 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1728 ..GLEASON..08/13/19 ATTN...WFO...RAH...AKQ... STATUS REPORT FOR WS 578 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC007-037-051-063-065-069-073-077-083-085-091-093-101-105-123- 125-127-131-135-153-163-165-167-181-183-185-191-195-132140- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ANSON CHATHAM CUMBERLAND DURHAM EDGECOMBE FRANKLIN GATES GRANVILLE HALIFAX HARNETT HERTFORD HOKE JOHNSTON LEE MONTGOMERY MOORE NASH NORTHAMPTON ORANGE RICHMOND SAMPSON SCOTLAND STANLY VANCE WAKE WARREN WAYNE WILSON VAC025-053-081-093-111-117-149-175-181-183-199-550-595-620-650- 670-700-710-735-740-800-810-132140- VA . VIRGINIA COUNTIES INCLUDED ARE Read more

WW 0576 Status Updates
STATUS REPORT ON WW 576 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE AND TO 20 S AVL TO 10 SE HKY TO 25 ENE HKY TO 20 WSW AVC. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1728 ..GLEASON..08/13/19 ATTN...WFO...GSP...RAH...RNK...MRX... STATUS REPORT FOR WS 576 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC001-025-033-035-045-057-059-067-071-081-097-109-119-145-151- 159-132140- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALAMANCE CABARRUS CASWELL CATAWBA CLEVELAND DAVIDSON DAVIE FORSYTH GASTON GUILFORD IREDELL LINCOLN MECKLENBURG PERSON RANDOLPH ROWAN SCC021-045-083-091-132140- SC . SOUTH CAROLINA COUNTIES INCLUDED ARE CHEROKEE GREENVILLE SPARTANBURG YORK Read more

MD 1728 CONCERNING SEVERE THUNDERSTORM WATCH 576...578... FOR PORTIONS OF SOUTH-CENTRAL/SOUTHEASTERN VA...MUCH OF NC...AND FAR NORTHERN SC
Mesoscale Discussion 1728 NWS Storm Prediction Center Norman OK 0330 PM CDT Tue Aug 13 2019 Areas affected...Portions of south-central/southeastern VA...much of NC...and far northern SC Concerning...Severe Thunderstorm Watch 576...578... Valid 132030Z - 132130Z The severe weather threat for Severe Thunderstorm Watch 576, 578 continues. SUMMARY...Scattered strong/gusty winds should continue to produce damage through the early evening across Severe Thunderstorm Watch 576 and 578. DISCUSSION...A loosely organized line of storms has recently crossed the Appalachians into parts of western/central NC and south-central VA. 30-40 kt of mid-level flow remains generally confined to portions of southern VA where instability is slightly weaker compared to locations farther south. Regardless, low-level lapse rates have been able to steepen ahead of ongoing convection owing to strong diurnal heating. Multiple tree damage reports have been received over the past few hours, and this threat should continue with eastward extent across central NC into southeastern VA through the early evening. Storms that can become oriented more orthogonal to the mean westerly flow should have a greater damaging wind potential. This wind threat may be maximized across north-central NC and southeastern VA in the short term based on radar trends. ..Gleason.. 08/13/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...RNK...CAE...GSP... LAT...LON 34858205 35848122 36278020 36577876 37317812 37467685 37277600 36607600 35027844 34927987 34858205 Read more

WW 0577 Status Updates
STATUS REPORT ON WW 577 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NE AKO TO 35 SSE SNY TO 30 ESE SNY TO 15 NNW LBF. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1727 ..MOSIER..08/13/19 ATTN...WFO...GLD...BOU...LBF... STATUS REPORT FOR WT 577 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC017-063-073-095-115-121-125-132140- CO . COLORADO COUNTIES INCLUDED ARE CHEYENNE KIT CARSON LINCOLN PHILLIPS SEDGWICK WASHINGTON YUMA KSC023-039-063-065-071-109-137-153-179-181-193-199-203-132140- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR GOVE GRAHAM GREELEY LOGAN NORTON RAWLINS SHERIDAN SHERMAN THOMAS WALLACE WICHITA NEC029-057-063-085-087-111-135-145-132140- Read more

MD 1727 CONCERNING TORNADO WATCH 577... FOR SOUTHWEST NE...NORTHEAST CO...NORTHWEST KS
Mesoscale Discussion 1727 NWS Storm Prediction Center Norman OK 0304 PM CDT Tue Aug 13 2019 Areas affected...Southwest NE...Northeast CO...Northwest KS Concerning...Tornado Watch 577... Valid 132004Z - 132130Z The severe weather threat for Tornado Watch 577 continues. SUMMARY...Threat for all severe hazards, including very large hail greater than 2" in diameter and tornadoes, continues across Tornado Watch 577. DISCUSSION...Radar signature within the storm over Perkins County NE suggests it has become more outflow dominant, although it still possesses a very strong updraft. This upscale growth/linear transition is expected to continue, gradually transitioning the primary severe threat from very large hail (i.e. greater than 2" in diameter) to strong wind gusts. Currently, all severe hazards, including a tornado or two, still remain possible with this storm. Farther southwest, a few discrete supercells have developed. Strong instability, southeasterly low-level flow, and ample low-level moisture suggests these storms will persist, posing a threat for all severe hazards, including brief tornadoes. ..Mosier.. 08/13/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...DDC...GLD...PUB...BOU... LAT...LON 38440228 38500352 38980400 40300281 40850244 41390181 41370060 40520019 38800056 38440228 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Tue Aug 13 2019 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE TENNESSEE VALLEY EASTWARD TO THE ATLANTIC SEABOARD... ...SUMMARY... Significant severe hail and wind gusts are possible across the central High Plains during the late afternoon to mid evening. Scattered damaging winds are possible from the Tennessee Valley to the Carolinas and southern Virginia through early evening. ...DISCUSSION... The main change to the outlook is to reorient the enhanced risk area in the central High Plains. The enhanced has been shifted eastward and now goes from southwest Nebraska and far northeastern Colorado into southwest Kansas which is aligned with the projected track of ongoing severe thunderstorms. The hail and wind damage probabilities have been changed according to the updated position of the enhanced risk area. Severe weather probabilities have been removed from parts of the central and northern High Plains to the north and northeast of the ongoing convection. ..Broyles.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Aug 13 2019/ ...Central High Plains... Weak warm-advection driven convection is ongoing across northwest/north-central NE. To its south, ample low-level moisture is prevalent. The difference between the NAM/RAP in the degree of boundary-layer mixing within the warm/moist sector is unusual in that the NAM is actually quite a bit more mixed at peak heating than the RAP (typically its the reverse). Surface dew points will probably mix to 60-65 F, contributing to a confined corridor of MLCAPE of 2000-3000 J/kg across the CO/KS/NE border area beneath rather steep mid-level lapse rates. Surface-based storm development is expected around 21Z near this tri-state region as convergence strengthens at the intersection of the lee trough and the southward-sagging cold front. Initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection should grow upscale into a southward propagating cluster into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for severe wind gusts into early tonight. ...TN Valley to the Carolinas/southern VA... A separated belt of enhanced 700-mb westerlies should remain centered on the KY to VA area through early evening. Areas of decaying stratiform rain remnants of early morning MCSs are generally located within this belt of stronger flow, largely south of 12Z HREF members. Convection is ongoing an arc across eastern TN into far southwest VA along the remnant outflow. Ample heating is occurring downstream across the Carolinas and it is possible that this convection intensifies (see MCD 1722). With flow weakening with southern extent, the degree of organization becomes increasingly uncertain, but at least a few multicell clusters should develop with a risk for scattered damaging winds across southern Virginia and parts of the Carolinas. Additional clusters should also form west across the TN Valley along the remnant outflow towards late afternoon as large buoyancy develops amid upper 70s surface dew points. Somewhat weaker effective shear from 15-25 kt should foster multicell clusters with a risk for isolated to scattered damaging winds. ...Upper MS Valley... A shortwave trough along the Red River Valley should dampen as it tracks into WI tonight. Ascent preceding this trough will coincide with a pocket of stronger surface heating and low-level convergence along a weak northwest-southeast oriented front, which will support scattered thunderstorm development towards late afternoon. A confined corridor of MLCAPE from 1000-1500 J/kg may potentially coincide with effective bulk shear near 40 kt. However, modest mid-level lapse rates should temper overall storm intensity despite the expectation of a few transient supercells. Isolated damaging winds and severe hail will likely be the main threats. A brief tornado may also occur with storms moving southeast along the boundary, where low-level shear and vertical vorticity will be larger. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Tue Aug 13 2019 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE TENNESSEE VALLEY EASTWARD TO THE ATLANTIC SEABOARD... ...SUMMARY... Significant severe hail and wind gusts are possible across the central High Plains during the late afternoon to mid evening. Scattered damaging winds are possible from the Tennessee Valley to the Carolinas and southern Virginia through early evening. ...DISCUSSION... The main change to the outlook is to reorient the enhanced risk area in the central High Plains. The enhanced has been shifted eastward and now goes from southwest Nebraska and far northeastern Colorado into southwest Kansas which is aligned with the projected track of ongoing severe thunderstorms. The hail and wind damage probabilities have been changed according to the updated position of the enhanced risk area. Severe weather probabilities have been removed from parts of the central and northern High Plains to the north and northeast of the ongoing convection. ..Broyles.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Aug 13 2019/ ...Central High Plains... Weak warm-advection driven convection is ongoing across northwest/north-central NE. To its south, ample low-level moisture is prevalent. The difference between the NAM/RAP in the degree of boundary-layer mixing within the warm/moist sector is unusual in that the NAM is actually quite a bit more mixed at peak heating than the RAP (typically its the reverse). Surface dew points will probably mix to 60-65 F, contributing to a confined corridor of MLCAPE of 2000-3000 J/kg across the CO/KS/NE border area beneath rather steep mid-level lapse rates. Surface-based storm development is expected around 21Z near this tri-state region as convergence strengthens at the intersection of the lee trough and the southward-sagging cold front. Initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection should grow upscale into a southward propagating cluster into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for severe wind gusts into early tonight. ...TN Valley to the Carolinas/southern VA... A separated belt of enhanced 700-mb westerlies should remain centered on the KY to VA area through early evening. Areas of decaying stratiform rain remnants of early morning MCSs are generally located within this belt of stronger flow, largely south of 12Z HREF members. Convection is ongoing an arc across eastern TN into far southwest VA along the remnant outflow. Ample heating is occurring downstream across the Carolinas and it is possible that this convection intensifies (see MCD 1722). With flow weakening with southern extent, the degree of organization becomes increasingly uncertain, but at least a few multicell clusters should develop with a risk for scattered damaging winds across southern Virginia and parts of the Carolinas. Additional clusters should also form west across the TN Valley along the remnant outflow towards late afternoon as large buoyancy develops amid upper 70s surface dew points. Somewhat weaker effective shear from 15-25 kt should foster multicell clusters with a risk for isolated to scattered damaging winds. ...Upper MS Valley... A shortwave trough along the Red River Valley should dampen as it tracks into WI tonight. Ascent preceding this trough will coincide with a pocket of stronger surface heating and low-level convergence along a weak northwest-southeast oriented front, which will support scattered thunderstorm development towards late afternoon. A confined corridor of MLCAPE from 1000-1500 J/kg may potentially coincide with effective bulk shear near 40 kt. However, modest mid-level lapse rates should temper overall storm intensity despite the expectation of a few transient supercells. Isolated damaging winds and severe hail will likely be the main threats. A brief tornado may also occur with storms moving southeast along the boundary, where low-level shear and vertical vorticity will be larger. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Tue Aug 13 2019 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE TENNESSEE VALLEY EASTWARD TO THE ATLANTIC SEABOARD... ...SUMMARY... Significant severe hail and wind gusts are possible across the central High Plains during the late afternoon to mid evening. Scattered damaging winds are possible from the Tennessee Valley to the Carolinas and southern Virginia through early evening. ...DISCUSSION... The main change to the outlook is to reorient the enhanced risk area in the central High Plains. The enhanced has been shifted eastward and now goes from southwest Nebraska and far northeastern Colorado into southwest Kansas which is aligned with the projected track of ongoing severe thunderstorms. The hail and wind damage probabilities have been changed according to the updated position of the enhanced risk area. Severe weather probabilities have been removed from parts of the central and northern High Plains to the north and northeast of the ongoing convection. ..Broyles.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Aug 13 2019/ ...Central High Plains... Weak warm-advection driven convection is ongoing across northwest/north-central NE. To its south, ample low-level moisture is prevalent. The difference between the NAM/RAP in the degree of boundary-layer mixing within the warm/moist sector is unusual in that the NAM is actually quite a bit more mixed at peak heating than the RAP (typically its the reverse). Surface dew points will probably mix to 60-65 F, contributing to a confined corridor of MLCAPE of 2000-3000 J/kg across the CO/KS/NE border area beneath rather steep mid-level lapse rates. Surface-based storm development is expected around 21Z near this tri-state region as convergence strengthens at the intersection of the lee trough and the southward-sagging cold front. Initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection should grow upscale into a southward propagating cluster into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for severe wind gusts into early tonight. ...TN Valley to the Carolinas/southern VA... A separated belt of enhanced 700-mb westerlies should remain centered on the KY to VA area through early evening. Areas of decaying stratiform rain remnants of early morning MCSs are generally located within this belt of stronger flow, largely south of 12Z HREF members. Convection is ongoing an arc across eastern TN into far southwest VA along the remnant outflow. Ample heating is occurring downstream across the Carolinas and it is possible that this convection intensifies (see MCD 1722). With flow weakening with southern extent, the degree of organization becomes increasingly uncertain, but at least a few multicell clusters should develop with a risk for scattered damaging winds across southern Virginia and parts of the Carolinas. Additional clusters should also form west across the TN Valley along the remnant outflow towards late afternoon as large buoyancy develops amid upper 70s surface dew points. Somewhat weaker effective shear from 15-25 kt should foster multicell clusters with a risk for isolated to scattered damaging winds. ...Upper MS Valley... A shortwave trough along the Red River Valley should dampen as it tracks into WI tonight. Ascent preceding this trough will coincide with a pocket of stronger surface heating and low-level convergence along a weak northwest-southeast oriented front, which will support scattered thunderstorm development towards late afternoon. A confined corridor of MLCAPE from 1000-1500 J/kg may potentially coincide with effective bulk shear near 40 kt. However, modest mid-level lapse rates should temper overall storm intensity despite the expectation of a few transient supercells. Isolated damaging winds and severe hail will likely be the main threats. A brief tornado may also occur with storms moving southeast along the boundary, where low-level shear and vertical vorticity will be larger. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Tue Aug 13 2019 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE TENNESSEE VALLEY EASTWARD TO THE ATLANTIC SEABOARD... ...SUMMARY... Significant severe hail and wind gusts are possible across the central High Plains during the late afternoon to mid evening. Scattered damaging winds are possible from the Tennessee Valley to the Carolinas and southern Virginia through early evening. ...DISCUSSION... The main change to the outlook is to reorient the enhanced risk area in the central High Plains. The enhanced has been shifted eastward and now goes from southwest Nebraska and far northeastern Colorado into southwest Kansas which is aligned with the projected track of ongoing severe thunderstorms. The hail and wind damage probabilities have been changed according to the updated position of the enhanced risk area. Severe weather probabilities have been removed from parts of the central and northern High Plains to the north and northeast of the ongoing convection. ..Broyles.. 08/13/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Aug 13 2019/ ...Central High Plains... Weak warm-advection driven convection is ongoing across northwest/north-central NE. To its south, ample low-level moisture is prevalent. The difference between the NAM/RAP in the degree of boundary-layer mixing within the warm/moist sector is unusual in that the NAM is actually quite a bit more mixed at peak heating than the RAP (typically its the reverse). Surface dew points will probably mix to 60-65 F, contributing to a confined corridor of MLCAPE of 2000-3000 J/kg across the CO/KS/NE border area beneath rather steep mid-level lapse rates. Surface-based storm development is expected around 21Z near this tri-state region as convergence strengthens at the intersection of the lee trough and the southward-sagging cold front. Initial storms will likely be discrete supercells capable of producing isolated very large hail and perhaps a tornado or two. Convection should grow upscale into a southward propagating cluster into a weak nocturnal low-level jet across far eastern CO/western KS, with a continuing threat for severe wind gusts into early tonight. ...TN Valley to the Carolinas/southern VA... A separated belt of enhanced 700-mb westerlies should remain centered on the KY to VA area through early evening. Areas of decaying stratiform rain remnants of early morning MCSs are generally located within this belt of stronger flow, largely south of 12Z HREF members. Convection is ongoing an arc across eastern TN into far southwest VA along the remnant outflow. Ample heating is occurring downstream across the Carolinas and it is possible that this convection intensifies (see MCD 1722). With flow weakening with southern extent, the degree of organization becomes increasingly uncertain, but at least a few multicell clusters should develop with a risk for scattered damaging winds across southern Virginia and parts of the Carolinas. Additional clusters should also form west across the TN Valley along the remnant outflow towards late afternoon as large buoyancy develops amid upper 70s surface dew points. Somewhat weaker effective shear from 15-25 kt should foster multicell clusters with a risk for isolated to scattered damaging winds. ...Upper MS Valley... A shortwave trough along the Red River Valley should dampen as it tracks into WI tonight. Ascent preceding this trough will coincide with a pocket of stronger surface heating and low-level convergence along a weak northwest-southeast oriented front, which will support scattered thunderstorm development towards late afternoon. A confined corridor of MLCAPE from 1000-1500 J/kg may potentially coincide with effective bulk shear near 40 kt. However, modest mid-level lapse rates should temper overall storm intensity despite the expectation of a few transient supercells. Isolated damaging winds and severe hail will likely be the main threats. A brief tornado may also occur with storms moving southeast along the boundary, where low-level shear and vertical vorticity will be larger. Read more

WW 0579 Status Updates
STATUS FOR WATCH 0579 HAS NOT BEEN ISSUED YET Read more