Aggregator

WW 0570 Status Updates
STATUS REPORT ON WW 570 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NNW PUB TO 30 WSW AKO TO 30 ESE CYS TO 60 WNW CDR. ..GOSS..08/11/19 ATTN...WFO...BOU...CYS... STATUS REPORT FOR WS 570 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC039-073-075-087-095-115-121-120040- CO . COLORADO COUNTIES INCLUDED ARE ELBERT LINCOLN LOGAN MORGAN PHILLIPS SEDGWICK WASHINGTON NEC007-013-033-045-105-123-157-165-120040- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER BOX BUTTE CHEYENNE DAWES KIMBALL MORRILL SCOTTS BLUFF SIOUX 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 570 SEVERE TSTM CO NE WY 111925Z - 120200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 570 NWS Storm Prediction Center Norman OK 125 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Colorado Western Nebraska Panhandle Southeast Wyoming * Effective this Sunday afternoon and evening from 125 PM until 800 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...A few supercells should develop just east of the Denver metro area along the I-76 corridor into northeast Colorado, while clusters are more predominant farther north across southeast Wyoming into the Nebraska Panhandle. The severe thunderstorm watch area is approximately along and 55 statute miles east and west of a line from 55 miles west northwest of Chadron NE to 35 miles east southeast of Colorado Springs CO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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 569... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24030. ...Grams Read more

WW 0572 Status Updates
STATUS REPORT ON WW 572 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..GOSS..08/11/19 ATTN...WFO...GLD...LBF... STATUS REPORT FOR WT 572 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC017-063-125-120040- CO . COLORADO COUNTIES INCLUDED ARE CHEYENNE KIT CARSON YUMA KSC023-039-063-071-109-153-179-181-193-199-203-120040- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR GOVE GREELEY LOGAN RAWLINS SHERIDAN SHERMAN THOMAS WALLACE WICHITA NEC029-049-057-063-085-087-101-111-135-145-120040- NE . NEBRASKA COUNTIES INCLUDED ARE CHASE DEUEL DUNDY FRONTIER HAYES HITCHCOCK Read more

000
ABPZ20 KNHC 112342
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sun Aug 11 2019

For the eastern North Pacific...east of 140 degrees west longitude:

Thunderstorm activity has become more concentrated near the center
of a small low pressure system located a few hundred miles south of
the southern tip of the Baja California peninsula. Satellite images
also indicate that the low is gradually becoming better defined. If
this recent development trend continues, then advisories could be
initiated on a tropical depression or a tropical storm later tonight
while the disturbance moves generally west-northwestward, away from
the coast of Mexico. Environmental conditions are expected to become
unfavorable for significant development by early Tuesday.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

An area of disturbed weather located about 1000 miles southwest of
the Baja California peninsula remains disorganized. Environmental
conditions are expected to become gradually more conducive for
tropical cyclone formation by the middle of the week while the
system moves west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...50 percent.

$$
Forecaster Stewart

WW 0570 Status Updates
STATUS REPORT ON WW 570 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NNW PUB TO 30 WSW AKO TO 30 ESE CYS TO 60 WNW CDR. ..GOSS..08/11/19 ATTN...WFO...BOU...CYS... STATUS REPORT FOR WS 570 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC039-073-075-087-095-115-121-120040- CO . COLORADO COUNTIES INCLUDED ARE ELBERT LINCOLN LOGAN MORGAN PHILLIPS SEDGWICK WASHINGTON NEC007-013-033-045-105-123-157-165-120040- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER BOX BUTTE CHEYENNE DAWES KIMBALL MORRILL SCOTTS BLUFF SIOUX 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 570 SEVERE TSTM CO NE WY 111925Z - 120200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 570 NWS Storm Prediction Center Norman OK 125 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Colorado Western Nebraska Panhandle Southeast Wyoming * Effective this Sunday afternoon and evening from 125 PM until 800 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...A few supercells should develop just east of the Denver metro area along the I-76 corridor into northeast Colorado, while clusters are more predominant farther north across southeast Wyoming into the Nebraska Panhandle. The severe thunderstorm watch area is approximately along and 55 statute miles east and west of a line from 55 miles west northwest of Chadron NE to 35 miles east southeast of Colorado Springs CO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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 569... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24030. ...Grams Read more

WW 0572 Status Updates
STATUS REPORT ON WW 572 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..GOSS..08/11/19 ATTN...WFO...GLD...LBF... STATUS REPORT FOR WT 572 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC017-063-125-120040- CO . COLORADO COUNTIES INCLUDED ARE CHEYENNE KIT CARSON YUMA KSC023-039-063-071-109-153-179-181-193-199-203-120040- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR GOVE GREELEY LOGAN RAWLINS SHERIDAN SHERMAN THOMAS WALLACE WICHITA NEC029-049-057-063-085-087-101-111-135-145-120040- NE . NEBRASKA COUNTIES INCLUDED ARE CHASE DEUEL DUNDY FRONTIER HAYES HITCHCOCK Read more

WW 572 TORNADO CO KS NE 112045Z - 120400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 572 NWS Storm Prediction Center Norman OK 245 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far eastern Colorado Northwest Kansas Southwest Nebraska * Effective this Sunday afternoon and evening from 245 PM until 1000 PM MDT. * Primary threats include... A couple tornadoes possible Scattered damaging winds and isolated significant gusts to 85 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Multiple discrete supercells will develop into far eastern Colorado with all severe hazards possible. These storms will likely consolidate and evolve into a bowing MCS that accelerates east along the Kansas-Nebraska border. This will yield an increasing risk for significant severe wind gusts later this evening. The tornado watch area is approximately along and 90 statute miles north and south of a line from 65 miles west southwest of Imperial NE to 25 miles south southeast of Mccook NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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 569...WW 570...WW 571... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 75 knots. A few cumulonimbi with maximum tops to 600. Mean storm motion vector 25035. ...Grams Read more

WW 0569 Status Updates
STATUS REPORT ON WW 569 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 ENE WEY TO 25 NNE LVM TO 20 SW LWT TO 50 S HVR. ..COOK..08/11/19 ATTN...WFO...TFX...BYZ... STATUS REPORT FOR WS 569 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC027-097-107-120040- MT . MONTANA COUNTIES INCLUDED ARE FERGUS SWEET GRASS WHEATLAND 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 0571 Status Updates
STATUS REPORT ON WW 571 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..COOK..08/11/19 ATTN...WFO...BYZ...UNR... STATUS REPORT FOR WT 571 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC003-009-011-017-025-037-065-075-087-095-103-111-120040- MT . MONTANA COUNTIES INCLUDED ARE BIG HORN CARBON CARTER CUSTER FALLON GOLDEN VALLEY MUSSELSHELL POWDER RIVER ROSEBUD STILLWATER TREASURE YELLOWSTONE SDC019-033-047-063-081-093-102-103-105-120040- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BUTTE CUSTER FALL RIVER HARDING LAWRENCE MEADE OGLALA LAKOTA PENNINGTON PERKINS WYC005-011-033-045-120040- WY . WYOMING COUNTIES INCLUDED ARE Read more

WW 569 SEVERE TSTM MT 111835Z - 120100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 569 NWS Storm Prediction Center Norman OK 1235 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest to central Montana * Effective this Sunday afternoon and evening from 1235 PM until 700 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Multiple supercells are expected to develop from southwest into central Montana. Large hail will be the primary initial hazard, but potential for severe wind gusts will increase later this afternoon as storms likely grow upscale into a cluster. The severe thunderstorm watch area is approximately along and 70 statute miles either side of a line from 45 miles west southwest of Dillon MT to 25 miles southeast of Lewistown MT. 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 22035. ...Grams Read more

WW 571 TORNADO MT SD WY 112000Z - 120300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 571 NWS Storm Prediction Center Norman OK 200 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Montana Western South Dakota Northeast Wyoming * Effective this Sunday afternoon and evening from 200 PM until 900 PM MDT. * Primary threats include... A couple tornadoes possible Scattered damaging winds and isolated significant gusts to 80 mph possible Scattered large hail and isolated very large hail events to 3 inches in diameter possible SUMMARY...Multiple discrete supercells will progress east-northeast from northeast Wyoming and south-central Montana. Large hail and a couple tornadoes should be the primary threat during the first few hours. Severe wind gust potential will increase later into the evening as cells likely consolidate into one or more clusters, especially across southern Montana. The tornado watch area is approximately along and 85 statute miles north and south of a line from 20 miles west northwest of Billings MT to 50 miles northeast of Rapid City SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 569...WW 570... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 24030. ...Grams Read more

MD 1706 CONCERNING TORNADO WATCH 572... FOR SOUTHWESTERN NEBRASKA...NORTHEASTERN COLORADO...AND NORTHWESTERN KANSAS
Mesoscale Discussion 1706 NWS Storm Prediction Center Norman OK 0605 PM CDT Sun Aug 11 2019 Areas affected...southwestern Nebraska...northeastern Colorado...and northwestern Kansas Concerning...Tornado Watch 572... Valid 112305Z - 120100Z The severe weather threat for Tornado Watch 572 continues. SUMMARY...Severe storms are forecast to continue spreading into Tornado Watch 572, yielding an increase in severe risk across the watch area. DISCUSSION...Thunderstorms continue to increase in coverage just west of WW 572, and should continue to spread into western portions of the watch. One large/complex storm continues to evolve over northern Yuma County, as multiple cells continue to develop along a surface boundary, and become ingested into the main rotating updraft. A tornado warning remains in effect for this storm, with severe weather risk expected to increase across western portions of the watch over the next couple of hours. ..Goss.. 08/11/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...DDC...GLD...PUB...BOU... LAT...LON 38809994 38220130 38580291 39440319 41220252 41510022 40449975 38809994 Read more

WW 0573 Status Updates
STATUS FOR WATCH 0573 HAS NOT BEEN ISSUED YET Read more

WW 573 SEVERE TSTM MT 112305Z - 120700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 573 NWS Storm Prediction Center Norman OK 505 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Montana * Effective this Sunday afternoon and Monday morning from 505 PM until 100 AM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Scattered large hail and isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...Clusters of thunderstorms over central Montana will track east-northeastward across the watch area this evening. A few supercells and bow echoes capable of damaging winds and large hail are possible. The severe thunderstorm watch area is approximately along and 80 statute miles north and south of a line from 85 miles west southwest of Glasgow MT to 10 miles north northeast of Sidney MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). 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 569...WW 570...WW 571...WW 572... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

MD 1705 CONCERNING SEVERE THUNDERSTORM WATCH 570... FOR EASTERN WYOMING/EASTERN COLORADO INTO THE NEBRASKA PANHANDLE
Mesoscale Discussion 1705 NWS Storm Prediction Center Norman OK 0551 PM CDT Sun Aug 11 2019 Areas affected...eastern Wyoming/eastern Colorado into the Nebraska Panhandle Concerning...Severe Thunderstorm Watch 570... Valid 112251Z - 120045Z The severe weather threat for Severe Thunderstorm Watch 570 continues. SUMMARY...Strong/locally severe thunderstorms continue across WW 570. DISCUSSION...Latest radar loop shows widespread thunderstorms -- including a few well-organized, rotating updrafts -- occurring over the central high Plains region. The storms are evolving near multiple/complex boundary interactions across the area. With low-level east-southeast flow advecting moist low-level air (60s dewpoints) into the high Plains fueling the convection, expect storms to continue for several hours. A couple of brief tornadoes have been reported over the past couple of hours, and large hail is also indicated with a couple of the most intense updrafts. These risks -- along with potential for locally damaging wind gusts -- are ongoing. With time, storms should grow upscale, and spread eastward into/across southwestern Nebraska and northwestern Kansas -- where Tornado Watch 572 is currently in effect. ..Goss/Hart.. 08/11/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...GLD...PUB...BOU...CYS... LAT...LON 38770317 38690459 40320519 41390525 41840585 43190606 43350355 42880275 40940268 38770317 Read more

000
ABNT20 KNHC 112245
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sun Aug 11 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Stewart

MD 1704 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWESTERN NORTH DAKOTA
Mesoscale Discussion 1704 NWS Storm Prediction Center Norman OK 0519 PM CDT Sun Aug 11 2019 Areas affected...southwestern North Dakota Concerning...Severe potential...Watch unlikely Valid 112219Z - 120015Z Probability of Watch Issuance...20 percent SUMMARY...Damaging wind gusts or an isolated tornado cannot be completely ruled out with convection across the discussion area. A WW issuance is not anticipated, though convective trends continue to be monitored. DISCUSSION...A cluster of strong to isolated severe storms continues across southwestern North Dakota currently. These storms are in a moderately unstable environment (1000-2000 J/kg MUCAPE) with sufficient deep shear (35-40 kts) for updraft organization, and even though low-level wind fields are relatively weak, easterly surface winds veering to westerly with height are supporting weak updraft rotation in the strongest cores. This is apparent with recently severe-warned convection over Adams County, and with time other storms may occasionally rotate given the shear profiles. Modest increases in low-level flow after about 00-01Z or so will also enhance shear profiles and further support rotation, though storms will also encounter gradually stabilizing boundary layer thermodynamic profiles in tandem with the strengthening shear. The scenario may only support an isolated severe threat in a localized, temporally brief nature that will not necessitate any WW issuance, although convective trends will be monitored for any increase in the threat beyond current expectations. ..Cook/Hart.. 08/11/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...BIS...UNR...BYZ...GGW... LAT...LON 46890386 47010273 47050127 46730037 46259999 45940011 45780157 45910323 45970390 46200419 46660423 46890386 Read more

000
ABPZ20 KNHC 112159
TWOEP

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
300 PM PDT Sun Aug 11 2019

For the eastern North Pacific...east of 140 degrees west longitude:

Special tropical weather outlook issued to update the discussion of
the low-pressure system south of the southern tip of the Baja
California peninsula.

Thunderstorm activity associated with a low pressure system located
a few hundred miles south of the southern tip of the Baja California
peninsula have become a little better organized during the past
several hours. In addition, recent satellite-derived surface wind
data indicate that the low has become better defined, with winds
just below tropical-storm strength occurring near and to the east
of the center. If this recent development trend continues, then
advisories could be initiated on a tropical depression or a tropical
storm later this evening while the disturbance moves westward to
west-northwestward, away from the coast of Mexico. Environmental
conditions are expected to become unfavorable for significant
development on Tuesday.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.

A disturbance located a little less than 1000 miles southwest of the
Baja California peninsula is producing a large area of disorganized
showers and thunderstorms. Environmental conditions are expected to
become more conducive for tropical cyclone formation by the middle
of the week while the system moves west-northwestward at 10 to 15
mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...50 percent.

$$
Forecaster Stewart

MD 1703 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTH-CENTRAL AND NORTHEASTERN MONTANA
Mesoscale Discussion 1703 NWS Storm Prediction Center Norman OK 0455 PM CDT Sun Aug 11 2019 Areas affected...north-central and northeastern Montana Concerning...Severe potential...Watch possible Valid 112155Z - 112300Z Probability of Watch Issuance...60 percent SUMMARY...Storms over central Montana will migrate northeastward into the discussion area after around 23Z or so. These storms may necessitate a WW issuance. DISCUSSION...An expanding cluster of mixed-mode (linear and cellular) storms continues to migrate northeastward across portions of central Montana (within WW 569). These storms are in a moderately unstable environment and have exhibited some upscale growth over time. Low-level easterlies veer to west-northwesterly and strengthen with height, allowing for some storm organization in this environment even though weak low-level shear is contributing largely to outflow-dominant convection. Though instability profiles are slightly less buoyant with northern extent, the expectation is that as storms continue to grow upscale and move northeastward into the discussion area, they will pose a risk of large hail and damaging wind gusts - especially if growth into a linear complex occurs as expected/depicted in latest CAMs. An isolated tornado cannot be completely ruled out either given the vertical shear profiles in place. Given these convective trends, a WW issuance is being considered around/after 23Z. ..Cook/Hart.. 08/11/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...BYZ...GGW...TFX... LAT...LON 48070958 48260912 48450646 48290480 47790395 46990377 46610439 46730664 46780810 47220889 47700953 48070958 Read more