Aggregator

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Fri Aug 30 2019 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Synopsis and Discussion... An upper high will remain over the Four Corners region, with the ridge axis shifting slowly east across the northern Rockies. To the east, weak northwesterly flow aloft will remain over the MO and mid/upper MS Valleys, with an embedded disturbance moving from KS into MO during the day. At the surface, high pressure will move eastward across the Great Lakes, with a quasi-stationary front extending from the central Plains across the OH Valley. Meanwhile, a weak area of low pressure will develop over west TX during the afternoon, with hot conditions. The air mass over the southern and central Plains, extending eastward across the OH Valley, will remain unstable, favoring scattered thunderstorms. Winds and shear will remain weak over the Plains and MO Valley, but localized strong wind gusts cannot be ruled out in association with storms which will persist throughout the period over KS, OK, MO and AR. In addition, it is uncertain precisely where the outflow boundaries will be located in this region. To the east, isolated afternoon storms are possible within the east-west oriented instability axis across the OH Valley. Steepening low-level lapse rates will favor storm development, but weak winds in the low-levels and a midlevel subsidence inversion suggests little organization. A few strong wind gusts or even small hail cannot be ruled out. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Jewell.. 08/30/2019 Read more

000
ABPZ20 KNHC 301718
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Fri Aug 30 2019

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

A broad area of low pressure has formed several hundred miles
south-southwest of the southwestern coast of Mexico. Environmental
conditions appear conducive for gradual development of this system
early next week as it moves generally west-northwestward.

* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Roberts

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Aug 30 2019 Valid 301630Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE HIGH PLAINS...MIDWEST...AND SOUTHEAST ARIZONA... ...SUMMARY... Isolated severe thunderstorms are possible this afternoon and evening across parts of the High Plains, and also across southeast Missouri/southern Illinois to southwest Ohio. ...High Plains... Post-frontal upslope flow will be common from northeast New Mexico to eastern Wyoming today, maintaining upper 40s to mid 50s surface dewpoints at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Stronger/confluent mid-level westerlies will generally be confined to the Wyoming portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern Wyoming to northeast Colorado. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central/southeast Missouri to southern Ohio... An MCV continues to move slowly eastward over west-central Missouri late this morning. While this MCV may tend to weaken today, a belt of modestly enhanced low/mid-level winds accompanying the MCV will coincide with a front across south-central/southeast Missouri into southern Illinois. There is a risk for a couple supercells capable of a tornado and isolated damaging winds, particularly along and south/southeast of I-44 in southeast Missouri, as well as southwest Illinois. Farther to the east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind across southern Indiana/northern Kentucky to southern Ohio. ...Southern Plains... Composite outflow/effective front continues to progress south/southwestward across the Texas Panhandle and Red River vicinity. Surface-based late afternoon redevelopment will probably be confined to the Texas Panhandle and possibly far western Oklahoma near the intersection of the composite outflow/front and dryline. A few severe thunderstorms are possible, but weakening deep-layer shear across the region will serve to limit the overall risk. ...Southeast Arizona... On the immediate southern periphery of an upper ridge, isolated thunderstorms are expected to develop over/near the mountains of southeast Arizona and drift west-southwestward with aid of modestly enhanced easterly mid-level winds. A reservoir of moist/unstable air may allow for some relatively stout storms, with strong/gusty outflow winds a possibility as they move across southeast Arizona. ..Guyer/Nauslar.. 08/30/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Aug 30 2019 Valid 301630Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE HIGH PLAINS...MIDWEST...AND SOUTHEAST ARIZONA... ...SUMMARY... Isolated severe thunderstorms are possible this afternoon and evening across parts of the High Plains, and also across southeast Missouri/southern Illinois to southwest Ohio. ...High Plains... Post-frontal upslope flow will be common from northeast New Mexico to eastern Wyoming today, maintaining upper 40s to mid 50s surface dewpoints at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Stronger/confluent mid-level westerlies will generally be confined to the Wyoming portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern Wyoming to northeast Colorado. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central/southeast Missouri to southern Ohio... An MCV continues to move slowly eastward over west-central Missouri late this morning. While this MCV may tend to weaken today, a belt of modestly enhanced low/mid-level winds accompanying the MCV will coincide with a front across south-central/southeast Missouri into southern Illinois. There is a risk for a couple supercells capable of a tornado and isolated damaging winds, particularly along and south/southeast of I-44 in southeast Missouri, as well as southwest Illinois. Farther to the east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind across southern Indiana/northern Kentucky to southern Ohio. ...Southern Plains... Composite outflow/effective front continues to progress south/southwestward across the Texas Panhandle and Red River vicinity. Surface-based late afternoon redevelopment will probably be confined to the Texas Panhandle and possibly far western Oklahoma near the intersection of the composite outflow/front and dryline. A few severe thunderstorms are possible, but weakening deep-layer shear across the region will serve to limit the overall risk. ...Southeast Arizona... On the immediate southern periphery of an upper ridge, isolated thunderstorms are expected to develop over/near the mountains of southeast Arizona and drift west-southwestward with aid of modestly enhanced easterly mid-level winds. A reservoir of moist/unstable air may allow for some relatively stout storms, with strong/gusty outflow winds a possibility as they move across southeast Arizona. ..Guyer/Nauslar.. 08/30/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Aug 30 2019 Valid 301630Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE HIGH PLAINS...MIDWEST...AND SOUTHEAST ARIZONA... ...SUMMARY... Isolated severe thunderstorms are possible this afternoon and evening across parts of the High Plains, and also across southeast Missouri/southern Illinois to southwest Ohio. ...High Plains... Post-frontal upslope flow will be common from northeast New Mexico to eastern Wyoming today, maintaining upper 40s to mid 50s surface dewpoints at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Stronger/confluent mid-level westerlies will generally be confined to the Wyoming portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern Wyoming to northeast Colorado. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central/southeast Missouri to southern Ohio... An MCV continues to move slowly eastward over west-central Missouri late this morning. While this MCV may tend to weaken today, a belt of modestly enhanced low/mid-level winds accompanying the MCV will coincide with a front across south-central/southeast Missouri into southern Illinois. There is a risk for a couple supercells capable of a tornado and isolated damaging winds, particularly along and south/southeast of I-44 in southeast Missouri, as well as southwest Illinois. Farther to the east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind across southern Indiana/northern Kentucky to southern Ohio. ...Southern Plains... Composite outflow/effective front continues to progress south/southwestward across the Texas Panhandle and Red River vicinity. Surface-based late afternoon redevelopment will probably be confined to the Texas Panhandle and possibly far western Oklahoma near the intersection of the composite outflow/front and dryline. A few severe thunderstorms are possible, but weakening deep-layer shear across the region will serve to limit the overall risk. ...Southeast Arizona... On the immediate southern periphery of an upper ridge, isolated thunderstorms are expected to develop over/near the mountains of southeast Arizona and drift west-southwestward with aid of modestly enhanced easterly mid-level winds. A reservoir of moist/unstable air may allow for some relatively stout storms, with strong/gusty outflow winds a possibility as they move across southeast Arizona. ..Guyer/Nauslar.. 08/30/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Aug 30 2019 Valid 301630Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE HIGH PLAINS...MIDWEST...AND SOUTHEAST ARIZONA... ...SUMMARY... Isolated severe thunderstorms are possible this afternoon and evening across parts of the High Plains, and also across southeast Missouri/southern Illinois to southwest Ohio. ...High Plains... Post-frontal upslope flow will be common from northeast New Mexico to eastern Wyoming today, maintaining upper 40s to mid 50s surface dewpoints at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Stronger/confluent mid-level westerlies will generally be confined to the Wyoming portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern Wyoming to northeast Colorado. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central/southeast Missouri to southern Ohio... An MCV continues to move slowly eastward over west-central Missouri late this morning. While this MCV may tend to weaken today, a belt of modestly enhanced low/mid-level winds accompanying the MCV will coincide with a front across south-central/southeast Missouri into southern Illinois. There is a risk for a couple supercells capable of a tornado and isolated damaging winds, particularly along and south/southeast of I-44 in southeast Missouri, as well as southwest Illinois. Farther to the east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind across southern Indiana/northern Kentucky to southern Ohio. ...Southern Plains... Composite outflow/effective front continues to progress south/southwestward across the Texas Panhandle and Red River vicinity. Surface-based late afternoon redevelopment will probably be confined to the Texas Panhandle and possibly far western Oklahoma near the intersection of the composite outflow/front and dryline. A few severe thunderstorms are possible, but weakening deep-layer shear across the region will serve to limit the overall risk. ...Southeast Arizona... On the immediate southern periphery of an upper ridge, isolated thunderstorms are expected to develop over/near the mountains of southeast Arizona and drift west-southwestward with aid of modestly enhanced easterly mid-level winds. A reservoir of moist/unstable air may allow for some relatively stout storms, with strong/gusty outflow winds a possibility as they move across southeast Arizona. ..Guyer/Nauslar.. 08/30/2019 Read more

No Mesoscale Discussions are in effect as of Fri Aug 30 16:34:02 UTC 2019.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1100 AM CDT Fri Aug 30 2019 Valid 301700Z - 311200Z The primary change with this forecast update was to expand the western edge of the isolated dry thunderstorm area farther west into northeast Utah, southwest Colorado, and extreme southeast Idaho. A few cloud to ground lightning flashes -- generally associated with dry thunderstorms -- are also possible across portions of northeast Oregon and vicinity. However, recent rainfall (locally > 0.5"), relatively marginal precipitable water values (0.8"-1"), and uncertainty regarding thunderstorm coverage precludes the introduction of an isolated dry thunderstorm area. See previous discussion below for more information on today's fire weather forecast. ..Elliott.. 08/30/2019 .PREV DISCUSSION... /ISSUED 0108 AM CDT Fri Aug 30 2019/ ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1100 AM CDT Fri Aug 30 2019 Valid 301700Z - 311200Z The primary change with this forecast update was to expand the western edge of the isolated dry thunderstorm area farther west into northeast Utah, southwest Colorado, and extreme southeast Idaho. A few cloud to ground lightning flashes -- generally associated with dry thunderstorms -- are also possible across portions of northeast Oregon and vicinity. However, recent rainfall (locally > 0.5"), relatively marginal precipitable water values (0.8"-1"), and uncertainty regarding thunderstorm coverage precludes the introduction of an isolated dry thunderstorm area. See previous discussion below for more information on today's fire weather forecast. ..Elliott.. 08/30/2019 .PREV DISCUSSION... /ISSUED 0108 AM CDT Fri Aug 30 2019/ ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1100 AM CDT Fri Aug 30 2019 Valid 301700Z - 311200Z The primary change with this forecast update was to expand the western edge of the isolated dry thunderstorm area farther west into northeast Utah, southwest Colorado, and extreme southeast Idaho. A few cloud to ground lightning flashes -- generally associated with dry thunderstorms -- are also possible across portions of northeast Oregon and vicinity. However, recent rainfall (locally > 0.5"), relatively marginal precipitable water values (0.8"-1"), and uncertainty regarding thunderstorm coverage precludes the introduction of an isolated dry thunderstorm area. See previous discussion below for more information on today's fire weather forecast. ..Elliott.. 08/30/2019 .PREV DISCUSSION... /ISSUED 0108 AM CDT Fri Aug 30 2019/ ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1100 AM CDT Fri Aug 30 2019 Valid 301700Z - 311200Z The primary change with this forecast update was to expand the western edge of the isolated dry thunderstorm area farther west into northeast Utah, southwest Colorado, and extreme southeast Idaho. A few cloud to ground lightning flashes -- generally associated with dry thunderstorms -- are also possible across portions of northeast Oregon and vicinity. However, recent rainfall (locally > 0.5"), relatively marginal precipitable water values (0.8"-1"), and uncertainty regarding thunderstorm coverage precludes the introduction of an isolated dry thunderstorm area. See previous discussion below for more information on today's fire weather forecast. ..Elliott.. 08/30/2019 .PREV DISCUSSION... /ISSUED 0108 AM CDT Fri Aug 30 2019/ ...Synopsis... A upper-level ridge will build across the western CONUS throughout the period, with stronger flow aloft associated with an approaching mid-level shortwave trough glancing the Pacific Northwest. In advance of the developing ridge, small shortwave perturbations embedded in the mid-level flow, combined with afternoon heating and upslope flow across the higher terrain, will promote the development of at least isolated, high-based thunderstorms across portions of the central Rockies. Locally dry, breezy conditions may also occur in terrain favoring locations across northern parts of the Great Basin into the central Rockies, with synoptic forcing to support a more widespread, favorable surface wind/RH parameter space largely absent given the aforementioned mid-level ridging pattern ...Central Rockies... A dry sub-cloud layer extending up to 500 mb, and precipitable water values between 0.50-0.75 inches will support dry strikes associated with high-based thunderstorms during the afternoon hours, where an isolated dry thunderstorm delineation was added. Near critical to critically dry fuels suggest that new ignitions will be possible, despite slower storm motions, especially on the periphery of the storm cores. Otherwise, 20% RH and surface westerly winds locally reaching the 15-20 mph range will be possible by peak afternoon heating, mainly across portions of the Snake River Plain, eastward to portions of the Great Divide Basin in central to southern Wyoming. The patchy nature of these dry, breezy conditions precludes an elevated delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Fri Aug 30 2019 Valid 301300Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE HIGH PLAINS TO SOUTHERN GREAT PLAINS AND SOUTH-CENTRAL MO TO SOUTHWEST OH... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the High Plains into the southern Great Plains, and separately from south-central Missouri to southwest Ohio, mainly through early evening. ...High Plains... Post-frontal upslope flow will be common from northeast NM to eastern WY today, maintaining upper 40s to mid 50s surface dew points at peak heating. This should support a plume of modest MLCAPE of 500-1500 J/kg. Confluent mid-level westerlies will generally be confined to the WY portion of the region where 500-mb flow of 35-45 kt is anticipated, with weaker winds southward along the Front Range. Isolated to scattered thunderstorms are expected to develop by mid to late afternoon over the higher terrain. A few of these storms should become supercellular for a couple hours across eastern WY to northeast CO. Abundant MLCIN with eastward extent on the plains and lack of stronger forcing for ascent should keep severe hail and wind coverage low. ...South-central MO to southern OH... An MCV over west-central MO should drift east towards the Mid-MS Valley before stalling tonight. Ongoing convection ahead of the MCV is decaying, yielding confidence that diabatic surface heating may become adequate for redevelopment later this afternoon. Should this overlap the narrow corridor of enhanced low-level shear/vorticity attendant to the MCV, the risk for a couple supercells capable of a tornado and isolated damaging wind may be realized. Farther east, a weakly convergent surface front might aid in small multicell clusters capable of locally damaging wind. ...Southern Great Plains... Composite outflow/effective front has reached southern OK into the TX Panhandle as a decaying MCS continues to push towards the Ark-La-Tex. Low-level warm advection atop the composite boundary has aided in persistent redevelopment across western OK. Marginally severe hail and wind will be possible with this latter activity, mainly through midday as the low-level jet subsides. Reference MCD 1898 for additional short-term information. Surface-based late afternoon development will probably be confined to the TX Panhandle vicinity near the intersection of the composite outflow/front and dryline. Weakening deep-layer shear across the region will serve to limit the overall threat. ..Grams/Leitman.. 08/30/2019 Read more

MD 1898 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WESTERN OK
Mesoscale Discussion 1898 NWS Storm Prediction Center Norman OK 0653 AM CDT Fri Aug 30 2019 Areas affected...western OK Concerning...Severe potential...Watch unlikely Valid 301153Z - 301400Z Probability of Watch Issuance...5 percent SUMMARY...Sporadic strong wind gusts and isolated hail near 1 inch are possible for a few hours this morning. A watch is not expected at this time. DISCUSSION...Scattered elevated thunderstorms are ongoing across western OK this morning. This convection is developing in a warm advection regime as a shortwave impulse tracks eastward across KS. A 30 kt southwesterly low level jet is aiding in semi-organized clusters on the edge of steep midlevel lapse rates across the southern and central High Plains. Most recently, a 59 mph gust was observed by the Oklahoma Mesonet site at Weatherford. Other gusts in the region have been sub-severe over the last hour. In addition to gusty winds, isolated hail near 1 inch is possible with the strongest cells. As the low level jet weakens through the morning and the upper shortwave impulse shifts east into MO, isolated severe potential should decrease as well across western OK. ..Leitman/Grams.. 08/30/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN... LAT...LON 35659988 36509964 36809939 36869869 36699801 36319765 35489756 34849806 34629856 34649916 34879962 35399993 35659988 Read more

000
ABPZ20 KNHC 301130
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Fri Aug 30 2019

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

A low pressure area is expected to form over the weekend several
hundred miles southwest of the southern tip of the Baja California
peninsula. Environmental conditions appear conducive for gradual
development of this system next week as it moves generally
west-northwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Roberts

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri Aug 30 2019 Valid 021200Z - 071200Z ...DISCUSSION... Primary features of interest during the extended period are Hurricane Dorian and strong shortwave trough expected to progress quickly through the northern CONUS westerlies from D4/Monday through D6/Wednesday. ...D4/Monday: Northern Plains/Upper Midwest... Air mass across the northern Plains and Upper Midwest is expected to be very moist and buoyant ahead of the approaching shortwave trough and attendant cold front on D4/Monday. Warm temperatures aloft should limit thunderstorm development throughout much of the day with initial convective initiation currently anticipated across the western Dakotas along the cold front. After initiation occurs, the strongly buoyant downstream air mass coupled with a progressive shortwave trough and increasing westerly/northwesterly flow suggest a favorable kinematic and thermodynamic environment for a forward-propagating MCS. ...FL Peninsula/Dorian... Regarding Dorian, current model forecasts and guidance from the National Hurricane Center move the storm into the southern FL Peninsula on D4/Monday. Forward motion is then expected to slow significantly, with the system moving slowly northward across the FL Peninsula on D5/Tuesday and D6/Wednesday. Given the anticipated storm trajectory and motion, an increasingly barotropic atmosphere will limit the overlap between the strong vertical shear and buoyancy. Additionally, the mesoscale details typically needed for TC-related tornadoes are difficult to predict at the medium range. Even so, some TC-related tornado threat is possible and this threat will be addressed in coordination with the National Hurricane Center in the coming days as confidence increases. Read more