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WW 0601 Status Updates
STATUS REPORT ON WW 601 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NNE SDA TO 35 S FOD TO 30 E OTG AND 30 ENE SDA TO 20 W OXV TO 40 SW ALO. ..MARSH..08/20/19 ATTN...WFO...DMX...FSD...OAX... STATUS REPORT FOR WS 601 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC007-039-051-053-099-117-123-125-135-157-159-171-173-175-179- 185-201240- IA . IOWA COUNTIES INCLUDED ARE APPANOOSE CLARKE DAVIS DECATUR JASPER LUCAS MAHASKA MARION MONROE POWESHIEK RINGGOLD TAMA TAYLOR UNION WAPELLO WAYNE 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 0601 Status Updates
STATUS REPORT ON WW 601 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NNE SDA TO 35 S FOD TO 30 E OTG AND 30 ENE SDA TO 20 W OXV TO 40 SW ALO. ..MARSH..08/20/19 ATTN...WFO...DMX...FSD...OAX... STATUS REPORT FOR WS 601 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC007-039-051-053-099-117-123-125-135-157-159-171-173-175-179- 185-201240- IA . IOWA COUNTIES INCLUDED ARE APPANOOSE CLARKE DAVIS DECATUR JASPER LUCAS MAHASKA MARION MONROE POWESHIEK RINGGOLD TAMA TAYLOR UNION WAPELLO WAYNE 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 0601 Status Updates
STATUS REPORT ON WW 601 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NNE SDA TO 35 S FOD TO 30 E OTG AND 30 ENE SDA TO 20 W OXV TO 40 SW ALO. ..MARSH..08/20/19 ATTN...WFO...DMX...FSD...OAX... STATUS REPORT FOR WS 601 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC007-039-051-053-099-117-123-125-135-157-159-171-173-175-179- 185-201240- IA . IOWA COUNTIES INCLUDED ARE APPANOOSE CLARKE DAVIS DECATUR JASPER LUCAS MAHASKA MARION MONROE POWESHIEK RINGGOLD TAMA TAYLOR UNION WAPELLO WAYNE 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 601 SEVERE TSTM IA MN SD 200455Z - 201200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 601 NWS Storm Prediction Center Norman OK 1155 PM CDT Mon Aug 19 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and central Iowa Far southwest Minnesota Far southeast South Dakota * Effective this Monday night and Tuesday morning from 1155 PM until 700 AM CDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Multiple elevated supercells will likely develop through the early morning hours before growing upscale into a linear cluster that may eventually bow across central to south-central Iowa. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 45 miles east of Lamoni IA to 15 miles west northwest of Worthington MN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 550. Mean storm motion vector 33030. ...Grams Read more

000
ABPZ20 KNHC 201142
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Tue Aug 20 2019

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

A low pressure system located a couple of hundred miles south of the
southern coast of Mexico continues to produce a large area of
cloudiness and thunderstorms. Environmental conditions are
conducive for development, and a tropical depression is likely to
form during the next day or so while the low moves west-
northwestward at 10 to 15 mph, parallel to and just offshore of the
coast of Mexico. This system could produce heavy rainfall and flash
flooding over portions of southeastern Mexico during the next couple
of days.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

Another low pressure system located more than 900 miles
west-southwest of the southern tip of the Baja California peninsula
is producing disorganized showers and a few thunderstorms.
Environmental conditions are expected to become more conducive for
development by mid-week, and a tropical depression is likely to form
during the next few days while the system moves westward to
west-northwestward at about 10 mph.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

$$
Forecaster Pasch

WW 0602 Status Updates
STATUS FOR WATCH 0602 HAS NOT BEEN ISSUED YET Read more

WW 0602 Status Updates
STATUS FOR WATCH 0602 HAS NOT BEEN ISSUED YET Read more

WW 0601 Status Updates
STATUS REPORT ON WW 601 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NNE SDA TO 35 S FOD TO 30 E OTG. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1808. ..MARSH..08/20/19 ATTN...WFO...DMX...FSD...OAX... STATUS REPORT FOR WS 601 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC001-003-007-015-023-033-039-049-051-053-063-069-075-077-079- 081-083-091-099-109-117-121-123-125-127-135-147-153-157-159-169- 171-173-175-179-181-185-187-189-197-201140- IA . IOWA COUNTIES INCLUDED ARE ADAIR ADAMS APPANOOSE BOONE BUTLER CERRO GORDO CLARKE DALLAS DAVIS DECATUR EMMET FRANKLIN GRUNDY GUTHRIE HAMILTON HANCOCK HARDIN HUMBOLDT JASPER KOSSUTH LUCAS MADISON MAHASKA MARION MARSHALL MONROE PALO ALTO POLK POWESHIEK RINGGOLD STORY TAMA TAYLOR UNION WAPELLO WARREN WAYNE WEBSTER WINNEBAGO WRIGHT Read more

MD 1808 CONCERNING SEVERE THUNDERSTORM WATCH 601... FOR EASTERN IOWA...NORTH-CENTRAL AND NORTHEAST MISSOURI AND MUCH OF CENTRAL AND NORTHERN ILLINOIS
Mesoscale Discussion 1808 NWS Storm Prediction Center Norman OK 0543 AM CDT Tue Aug 20 2019 Areas affected...eastern Iowa...north-central and northeast Missouri and much of central and northern Illinois Concerning...Severe Thunderstorm Watch 601... Valid 201043Z - 201215Z The severe weather threat for Severe Thunderstorm Watch 601 continues. SUMMARY...Thunderstorms continue to organize across central Iowa this morning. Over the next couple of hours these storms will move out of Severe Thunderstorm Watch #601. Hail and damaging wind potential will require the issuance of a new watch across portions of eastern Iowa, north-central and northeast Missouri and much of northern/central Illinois. DISCUSSION...Thunderstorms continue to organize this morning across central Iowa and accelerate southeastward this morning. The airmass feeding this complex of storms remains very supportive of severe thunderstorms, with most-unstable CAPE values in excess of 4000 J/kg and deep-layer shear between 40-50 knots. The leading edge of these thunderstorms currently extends from northeast Ringgold County, Iowa, north-northeast toward Polk County, Iowa. Additionally, to the northeast of this line, thunderstorms are developing in a more northwest-to-southeast orientation, including across portions of southeast Iowa that are currently not in Severe Thunderstorm Watch #601. Given continued development to the east of Severe Thunderstorm Watch #601 and the accelerating southeast motion of thunderstorms across south-central Iowa, coupled with the extreme instability and sufficient deep-layer shear values (in excess of 40 knots), a new watch downstream of #601 will be required in the next hour. ..Marsh.. 08/20/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...LSX...DVN...DMX...EAX... LAT...LON 40569423 42529210 42118857 39498937 39199203 40569423 Read more

MD 1807 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN AND CENTRAL MINNESOTA
Mesoscale Discussion 1807 NWS Storm Prediction Center Norman OK 0523 AM CDT Tue Aug 20 2019 Areas affected...northern and central Minnesota Concerning...Severe potential...Watch possible Valid 201023Z - 201200Z Probability of Watch Issuance...40 percent SUMMARY...Elevated, and loosely organized, thunderstorms across eastern North Dakota have developed into a small, compact bow echo. Hail and gusty winds will be possible with this bow. A watch is currently not expected, but conditions will be monitored through the morning. DISCUSSION...Loosely organized, elevated thunderstorms persist this morning across the north-central United States. These thunderstorms originated around midnight central time across eastern North Dakota and have produced episodic reports of large hail through the night. Recent radar imagery suggests this cluster of thunderstorms is beginning to better organize, with an apparent small, compact bow taking shape across northern Becker County. Although the source region of the airmass in question is extremely favorable for severe thunderstorms -- namely 5000-6000 J/kg of most-unstable CAP and deep-layer shear of 40-50 knots -- the airmass that lies ahead of these storms is devoid of this kind of instability given surface temperatures in the low/mid 60 F with similar surface dewpoints. This increasingly hostile thermodynamic environment should limit the overall severe threat. However, once thunderstorms develop organization they can, and often do, persist farther into poor thermodynamic environments than initially thought. For this reason, although a watch is currently not expected, conditions and trends will be monitored through the morning. ..Marsh/Edwards.. 08/20/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...MPX...FGF... LAT...LON 47629722 47399453 46869289 45159267 45159415 46549627 47629722 Read more

WW 0601 Status Updates
STATUS REPORT ON WW 601 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ESE SUX TO 15 N DNS TO 10 ENE OTG. ..MARSH..08/20/19 ATTN...WFO...DMX...FSD...OAX... STATUS REPORT FOR WS 601 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC001-003-007-009-015-021-023-025-027-029-033-039-041-047-049- 051-053-059-063-069-073-075-077-079-081-083-091-099-109-117-121- 123-125-127-133-135-147-151-153-157-159-161-165-169-171-173-175- 179-181-185-187-189-197-201040- IA . IOWA COUNTIES INCLUDED ARE ADAIR ADAMS APPANOOSE AUDUBON BOONE BUENA VISTA BUTLER CALHOUN CARROLL CASS CERRO GORDO CLARKE CLAY CRAWFORD DALLAS DAVIS DECATUR DICKINSON EMMET FRANKLIN GREENE GRUNDY GUTHRIE HAMILTON HANCOCK HARDIN HUMBOLDT JASPER KOSSUTH LUCAS MADISON MAHASKA MARION MARSHALL MONONA MONROE PALO ALTO POCAHONTAS POLK POWESHIEK RINGGOLD SAC SHELBY STORY TAMA TAYLOR UNION WAPELLO WARREN WAYNE WEBSTER Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Tue Aug 20 2019 Valid 231200Z - 281200Z ...DISCUSSION... High pressure will move eastward across the Great Lakes on Friday/D4 as a large upper trough exits the northeastern states. This will allow for southerly winds to increase across the Plains, with a plume of 60s F dewpoints extending northward through the Dakotas. Meanwhile, a small lead wave will move from the Dakotas into western Ontario, with a weakly convergent cold front over the western Dakotas. Marginally severe storms will be possible over this region on Friday/D4 with hail the main threat. By Saturday/D5, an elongated belt of strong upper winds will nose into the northern Rockies, with a more pronounced amplification into Sunday/D6 and Monday/D7 from the northern Plains into the upper MS Valley. A few severe storms are possible along the front Saturday/D5 over ND, and perhaps overnight into southern MN or IA related to warm advection with a low-level jet, although winds aloft will not be strong that far east. The most likely time frame for more widespread severe storms will be from 12Z Sunday/D6 to 12Z Tuesday/D8, from the eastern Dakotas across MN, IA, WI, and perhaps northern IL. Given a series of fast-moving waves within the larger-scale flow aloft, the possibility of nightly MCSs, and model differences, predictability is too low to precisely place severe corridors. However, 15% or greater probabilities are possible in later updates, mainly for damaging wind potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Tue Aug 20 2019 Valid 231200Z - 281200Z ...DISCUSSION... High pressure will move eastward across the Great Lakes on Friday/D4 as a large upper trough exits the northeastern states. This will allow for southerly winds to increase across the Plains, with a plume of 60s F dewpoints extending northward through the Dakotas. Meanwhile, a small lead wave will move from the Dakotas into western Ontario, with a weakly convergent cold front over the western Dakotas. Marginally severe storms will be possible over this region on Friday/D4 with hail the main threat. By Saturday/D5, an elongated belt of strong upper winds will nose into the northern Rockies, with a more pronounced amplification into Sunday/D6 and Monday/D7 from the northern Plains into the upper MS Valley. A few severe storms are possible along the front Saturday/D5 over ND, and perhaps overnight into southern MN or IA related to warm advection with a low-level jet, although winds aloft will not be strong that far east. The most likely time frame for more widespread severe storms will be from 12Z Sunday/D6 to 12Z Tuesday/D8, from the eastern Dakotas across MN, IA, WI, and perhaps northern IL. Given a series of fast-moving waves within the larger-scale flow aloft, the possibility of nightly MCSs, and model differences, predictability is too low to precisely place severe corridors. However, 15% or greater probabilities are possible in later updates, mainly for damaging wind potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Tue Aug 20 2019 Valid 231200Z - 281200Z ...DISCUSSION... High pressure will move eastward across the Great Lakes on Friday/D4 as a large upper trough exits the northeastern states. This will allow for southerly winds to increase across the Plains, with a plume of 60s F dewpoints extending northward through the Dakotas. Meanwhile, a small lead wave will move from the Dakotas into western Ontario, with a weakly convergent cold front over the western Dakotas. Marginally severe storms will be possible over this region on Friday/D4 with hail the main threat. By Saturday/D5, an elongated belt of strong upper winds will nose into the northern Rockies, with a more pronounced amplification into Sunday/D6 and Monday/D7 from the northern Plains into the upper MS Valley. A few severe storms are possible along the front Saturday/D5 over ND, and perhaps overnight into southern MN or IA related to warm advection with a low-level jet, although winds aloft will not be strong that far east. The most likely time frame for more widespread severe storms will be from 12Z Sunday/D6 to 12Z Tuesday/D8, from the eastern Dakotas across MN, IA, WI, and perhaps northern IL. Given a series of fast-moving waves within the larger-scale flow aloft, the possibility of nightly MCSs, and model differences, predictability is too low to precisely place severe corridors. However, 15% or greater probabilities are possible in later updates, mainly for damaging wind potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Tue Aug 20 2019 Valid 231200Z - 281200Z ...DISCUSSION... High pressure will move eastward across the Great Lakes on Friday/D4 as a large upper trough exits the northeastern states. This will allow for southerly winds to increase across the Plains, with a plume of 60s F dewpoints extending northward through the Dakotas. Meanwhile, a small lead wave will move from the Dakotas into western Ontario, with a weakly convergent cold front over the western Dakotas. Marginally severe storms will be possible over this region on Friday/D4 with hail the main threat. By Saturday/D5, an elongated belt of strong upper winds will nose into the northern Rockies, with a more pronounced amplification into Sunday/D6 and Monday/D7 from the northern Plains into the upper MS Valley. A few severe storms are possible along the front Saturday/D5 over ND, and perhaps overnight into southern MN or IA related to warm advection with a low-level jet, although winds aloft will not be strong that far east. The most likely time frame for more widespread severe storms will be from 12Z Sunday/D6 to 12Z Tuesday/D8, from the eastern Dakotas across MN, IA, WI, and perhaps northern IL. Given a series of fast-moving waves within the larger-scale flow aloft, the possibility of nightly MCSs, and model differences, predictability is too low to precisely place severe corridors. However, 15% or greater probabilities are possible in later updates, mainly for damaging wind potential. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Tue Aug 20 2019 Valid 231200Z - 281200Z ...DISCUSSION... High pressure will move eastward across the Great Lakes on Friday/D4 as a large upper trough exits the northeastern states. This will allow for southerly winds to increase across the Plains, with a plume of 60s F dewpoints extending northward through the Dakotas. Meanwhile, a small lead wave will move from the Dakotas into western Ontario, with a weakly convergent cold front over the western Dakotas. Marginally severe storms will be possible over this region on Friday/D4 with hail the main threat. By Saturday/D5, an elongated belt of strong upper winds will nose into the northern Rockies, with a more pronounced amplification into Sunday/D6 and Monday/D7 from the northern Plains into the upper MS Valley. A few severe storms are possible along the front Saturday/D5 over ND, and perhaps overnight into southern MN or IA related to warm advection with a low-level jet, although winds aloft will not be strong that far east. The most likely time frame for more widespread severe storms will be from 12Z Sunday/D6 to 12Z Tuesday/D8, from the eastern Dakotas across MN, IA, WI, and perhaps northern IL. Given a series of fast-moving waves within the larger-scale flow aloft, the possibility of nightly MCSs, and model differences, predictability is too low to precisely place severe corridors. However, 15% or greater probabilities are possible in later updates, mainly for damaging wind potential. Read more

MD 1806 CONCERNING SEVERE THUNDERSTORM WATCH 601... FOR IOWA
Mesoscale Discussion 1806 NWS Storm Prediction Center Norman OK 0308 AM CDT Tue Aug 20 2019 Areas affected...Iowa Concerning...Severe Thunderstorm Watch 601... Valid 200808Z - 200945Z The severe weather threat for Severe Thunderstorm Watch 601 continues. SUMMARY...Thunderstorms are developing across northwest Iowa. With time these thunderstorms should congeal into a complex that will move southeast through the morning. Large hail, damaging winds, and a brief tornado will be possible with the early morning storms, before a transition to primarily a damaging wind threat becomes likely later this morning. DISCUSSION...Persistent warm-air advection atop a northwest-to-southeast oriented warm front across western Iowa has resulted in elevated thunderstorms developing across northwest Iowa. The thunderstorms are tapping into a CAPE reservoir in excess of 5000 J/kg and are located in the presence of 40-55 knots of deep-layer shear. Given this thermodynamic and kinematic environment, along with midlevel lapse rates around 8-8.5 C/km, supercells capable of large hail and gusty thunderstorm winds, and a brief tornado will be possible. With time, increasing coverage of thunderstorms and congealing thunderstorm outflows should promote the upscale growth toward a mesoscale convective system (MCS). The resulting MCS should develop/move east-southeast with time -- generally along and north of the warm front -- with an increasing threat for strong thunderstorm winds despite being near the climatological minimum in surface wind potential given the time of day. ..Marsh.. 08/20/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX...EAX...FSD...OAX... LAT...LON 42479646 42739662 43159641 43289657 43499657 43499349 43299351 43259301 42959301 42909254 42329252 42279233 41549229 41499242 41189240 41179219 40579218 40569490 41179492 41199521 41499516 41519545 41609556 41869555 41899616 42479646 Read more

WW 0601 Status Updates
STATUS REPORT ON WW 601 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N SUX TO 20 ENE FSD. ..MARSH..08/20/19 ATTN...WFO...DMX...FSD...OAX... STATUS REPORT FOR WS 601 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC001-003-007-009-015-021-023-025-027-029-033-035-039-041-047- 049-051-053-059-063-069-073-075-077-079-081-083-091-093-099-109- 117-119-121-123-125-127-133-135-141-143-147-149-151-153-157-159- 161-165-167-169-171-173-175-179-181-185-187-189-193-197- 200840- IA . IOWA COUNTIES INCLUDED ARE ADAIR ADAMS APPANOOSE AUDUBON BOONE BUENA VISTA BUTLER CALHOUN CARROLL CASS CERRO GORDO CHEROKEE CLARKE CLAY CRAWFORD DALLAS DAVIS DECATUR DICKINSON EMMET FRANKLIN GREENE GRUNDY GUTHRIE HAMILTON HANCOCK HARDIN HUMBOLDT IDA JASPER KOSSUTH LUCAS LYON MADISON MAHASKA MARION MARSHALL MONONA MONROE O'BRIEN OSCEOLA PALO ALTO PLYMOUTH POCAHONTAS POLK POWESHIEK RINGGOLD SAC Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue Aug 20 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN KANSAS AND MISSOURI INTO NORTHERN OKLAHOMA AND ARKANSAS...AND OVER THE NORTHERN HIGH PLAINS... ...SUMMARY... At least isolated severe storms are possible Thursday from parts of Kansas and Oklahoma eastward across Missouri and Arkansas, and from eastern Montana into the western Dakotas. ...Synopsis... Strong west/southwest winds aloft will remain over the Northeast as an upper low moves slowly east across Quebec, and a cold front moves rapidly east across New England providing drying. To the west, a progressive shortwave trough will move across MT and ND, providing cooling aloft and lift. At the surface, a westward continuation of the New England cold front will remain quasi-stationary from the OH Valley into the central/southern Plains, with ample moisture and instability for thunderstorms. ...Southern KS and MO into northern OK and AR... Areas of storms are likely to be ongoing Thursday morning along the primary east-west front, most likely across KS, MO, and IL. Heating will occur south of this activity and attendant outflow boundaries, mainly over OK and AR, removing convective inhibition. Weakly veering low-level winds with height beneath 20 kt mean midlevel westerlies will favor southeastward-moving clusters of storms, with a marginal wind threat. ...Northern High Plains... A cold front will move into eastern MT and WY Thursday afternoon, providing convergence as southeast winds ahead of it maintain mid to upper 50s F dewpoints. Steep lapse rates through a deep layer as well as modest 30 kt deep-layer shear will likely favor mixed storm mode with at least isolated severe hail or wind. Storms will likely weaken and/or become elevated overnight as they continue into the western Dakotas where capping will exist. ..Jewell.. 08/20/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue Aug 20 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN KANSAS AND MISSOURI INTO NORTHERN OKLAHOMA AND ARKANSAS...AND OVER THE NORTHERN HIGH PLAINS... ...SUMMARY... At least isolated severe storms are possible Thursday from parts of Kansas and Oklahoma eastward across Missouri and Arkansas, and from eastern Montana into the western Dakotas. ...Synopsis... Strong west/southwest winds aloft will remain over the Northeast as an upper low moves slowly east across Quebec, and a cold front moves rapidly east across New England providing drying. To the west, a progressive shortwave trough will move across MT and ND, providing cooling aloft and lift. At the surface, a westward continuation of the New England cold front will remain quasi-stationary from the OH Valley into the central/southern Plains, with ample moisture and instability for thunderstorms. ...Southern KS and MO into northern OK and AR... Areas of storms are likely to be ongoing Thursday morning along the primary east-west front, most likely across KS, MO, and IL. Heating will occur south of this activity and attendant outflow boundaries, mainly over OK and AR, removing convective inhibition. Weakly veering low-level winds with height beneath 20 kt mean midlevel westerlies will favor southeastward-moving clusters of storms, with a marginal wind threat. ...Northern High Plains... A cold front will move into eastern MT and WY Thursday afternoon, providing convergence as southeast winds ahead of it maintain mid to upper 50s F dewpoints. Steep lapse rates through a deep layer as well as modest 30 kt deep-layer shear will likely favor mixed storm mode with at least isolated severe hail or wind. Storms will likely weaken and/or become elevated overnight as they continue into the western Dakotas where capping will exist. ..Jewell.. 08/20/2019 Read more