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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 142000Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible over parts of the north-central Plains this afternoon and evening. ...20z Update... Minimal changes have been made to trim the northern Plains Marginal behind ongoing convection, otherwise the Day 1 Convective Outlook remains on track. See previous discussion below for more information. ..Thornton/Gleason.. 09/14/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sat Sep 14 2024/ ...Northern/Central Plains... Modest ascent associated with a weak shortwave trough over eastern WY is encouraging towering cu and recent thunderstorm initiation across parts of western/central NE late this morning. This convective development is also occurring along/near a weak surface trough. Even though large-scale ascent is expected to remain fairly modest across much of the northern/central Plains today in the wake of a more prominent upper trough moving northeastward over central Canada, most guidance still shows potential for isolated to scattered thunderstorms developing this afternoon across parts of northwest NE into western/central SD along/near the surface trough. With modest/shallow low-level moisture in place, but steep mid-level lapse rates per 12Z LBF/UNR soundings, robust daytime heating will likely support around 1000-2000 J/kg of MLCAPE by mid afternoon. West-southwesterly flow at mid levels is forecast to be only modestly enhanced by the passing shortwave trough. Still, a veering and gradually strengthening wind profile with height through mid levels should support around 25-35 kt of deep-layer shear. Occasional hail may occur with any marginal supercells that can initially develop, although tendency for clustering and outflow interactions may lead to an isolated severe wind threat with time late this afternoon and early evening. The overall severe risk should quickly wane this evening with the loss of daytime heating. ...Southern High Plains... At least isolated high-based thunderstorms should develop this afternoon across parts of the TX Panhandle and vicinity along/east of a weak surface front/trough. With a deeply mixed boundary layer expected with daytime heating, occasional strong/gusty downdraft winds may occur with the more robust cores. However, weak deep-layer shear should keep the overall severe wind threat rather isolated. ...East Texas into Southern Louisiana/Mississippi... Isolated to widely scattered thunderstorms may develop along a weak front from parts of east TX into southern LA/MS later this afternoon. This activity would occur on the back side of a remnant mid-level circulation over the Mid-South. While modestly enhanced mid-level flow will be present, the potential for a more organized severe wind threat appears too low to include probabilities at this time. Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Sep 14 2024 Valid 161200Z - 221200Z A broad mid-level trough, with multiple embedded impulses, will amplify while gradually translating eastward from the West Coast to the Plains states through the upcoming week. Rainfall should accompany the passing mid-level trough across the Interior West through early parts of the week. Ahead of the mid-level trough, patches of overlapping dry and breezy conditions may develop along parts of the High Plains through Day 5/Wednesday. These conditions are too localized to address with Critical probabilities this outlook, though Elevated highlights may be introduced by Days 1-2. A dry low-level air mass should linger over parts of the Ohio Valley through the middle of the upcoming week. Surface high pressure across the Northeast will encourage dry easterly flow atop receptive fuels over portions of Indiana into Ohio and surrounding areas. Medium-range guidance consensus suggests that surface winds should not be overly strong, so any fire weather highlights that are added would probably take place in the Days 1-2 time frame if areas of locally higher gusts becomes apparent in short-range guidance. ..Squitieri.. 09/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2067 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF WESTERN AND CENTRAL SOUTH DAKOTA
Mesoscale Discussion 2067 NWS Storm Prediction Center Norman OK 0116 PM CDT Sat Sep 14 2024 Areas affected...portions of western and central South Dakota Concerning...Severe potential...Watch unlikely Valid 141816Z - 142015Z Probability of Watch Issuance...20 percent SUMMARY...Isolated thunderstorms -- the strongest of which may produce strong/damaging wind gusts and possibly severe-caliber hail -- are expected from parts of western and central South Dakota. The very isolated nature of the risk anticipated at this time should preclude the need for WW issuance. DISCUSSION...Latest radar loop shows isolated, vigorous storms east of the Black Hills area, with the strongest cells moving northeastward across the Haakon/Jackson County area at this time. The convection is ongoing within an environment featuring modestly increasing/veering flow with height, providing shear sufficient for at least multicell organization. Though CAPE will remain limited due to the dry boundary layer (around 1000 J/kg mixed-layer CAPE will prevail across the area), a deep sub-cloud layer has evolved in conjunction with diurnal heating. As such, sub-cloud evaporation -- and thus potential for acceleration of the downdrafts -- suggests that a few stronger/potentially severe gusts will be possible. However, with storms expected to remain isolated, severe-weather coverage is expected to remain insufficient to require WW consideration. ..Goss/Gleason.. 09/14/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...UNR... LAT...LON 45440172 44300327 43030229 43170131 43800026 44659929 45330089 45440172 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT BASIN INTO THE FOUR CORNERS REGION... ...SUMMARY... Isolated severe gusts and small to marginally severe hail will be possible on Monday afternoon to early evening across parts of the eastern Great Basin to Four Corners. ...Synopsis... The upper-level trough currently in place across the northeastern Pacific is forecast to amplify over the next 24-72 hours as it migrates southward along the West Coast and eventually into the Great Basin. As this occurs, an attendant mid-level jet streak will pivot into the interior West. The combination of increasing ascent and strengthening mid/upper-level winds will support isolated to scattered strong to severe thunderstorms across parts of the Great Basin and Four Corners. To the east across the Plains, surface pressure falls will become increasingly concentrated across the central to northern High Plains, which will maintain a moisture return regime. Weak ascent over a broadening warm sector will support isolated to widely scattered thunderstorm chances. ...Great Basin/Four Corners... Forecast guidance continues to show reasonably good agreement in strengthening wind fields across NV into UT and AZ by peak heating Monday as the mid/upper jet noses into the region. Mid-level lapse rates will steepen through the day ahead of the approaching wave, which, despite very modest moisture content, should support adequate buoyancy for convection. Deep, well-mixed boundary layers will facilitate efficient downward mixing of strong mid-level flow, which will likely be augmented by evaporatively-cooled downdraft accelerations. Consequently, the probability for strong to severe wind gusts appears higher and somewhat more concentrated compared to preceding days. Portions of the Four Corners region may also see a large hail threat given elongated wind profiles and slightly better buoyancy due to an influx of low/mid-level moisture from the Gulf of California. ...Central to northern Plains... Northward moisture return is expected to persist through Monday evening as a lee cyclone becomes more consolidated across the central to northern High Plains. With the primary upper-level trough displaced well to the west, synoptic-scale ascent will remain weak across the Great Plains region. However, signals for thunderstorm development within a modest warm-advection regime across ND and along the lee trough over parts of central/western KS into far northwest OK are noted in recent solutions. Predictability in either scenario is too limited to warrant risk probabilities, but the convective parameter space across both ND and KS/OK appears conducive for a conditional severe threat. ...Coastal North Carolina... A low off the Carolina coast is forecast to gradually intensify/organize over the next 72 hours, though forecast uncertainty regarding its exact evolution remains very high (see the latest NHC forecast discussion for additional details). However, a few solutions, notably recent GFS and NAM runs, suggest the low will migrate inland across the Carolinas during the day Monday. As this occurs, a narrow swath of high theta-e air will span from the NC coast into eastern NC and perhaps southeast VA. Wind profiles within this swath may feature strong low-level helicity that could support some tornado threat given sufficient buoyancy for deep convection. Confidence in this scenario remains very limited, but forecast trends will be monitored. ..Moore.. 09/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT BASIN INTO THE FOUR CORNERS REGION... ...SUMMARY... Isolated severe gusts and small to marginally severe hail will be possible on Monday afternoon to early evening across parts of the eastern Great Basin to Four Corners. ...Synopsis... The upper-level trough currently in place across the northeastern Pacific is forecast to amplify over the next 24-72 hours as it migrates southward along the West Coast and eventually into the Great Basin. As this occurs, an attendant mid-level jet streak will pivot into the interior West. The combination of increasing ascent and strengthening mid/upper-level winds will support isolated to scattered strong to severe thunderstorms across parts of the Great Basin and Four Corners. To the east across the Plains, surface pressure falls will become increasingly concentrated across the central to northern High Plains, which will maintain a moisture return regime. Weak ascent over a broadening warm sector will support isolated to widely scattered thunderstorm chances. ...Great Basin/Four Corners... Forecast guidance continues to show reasonably good agreement in strengthening wind fields across NV into UT and AZ by peak heating Monday as the mid/upper jet noses into the region. Mid-level lapse rates will steepen through the day ahead of the approaching wave, which, despite very modest moisture content, should support adequate buoyancy for convection. Deep, well-mixed boundary layers will facilitate efficient downward mixing of strong mid-level flow, which will likely be augmented by evaporatively-cooled downdraft accelerations. Consequently, the probability for strong to severe wind gusts appears higher and somewhat more concentrated compared to preceding days. Portions of the Four Corners region may also see a large hail threat given elongated wind profiles and slightly better buoyancy due to an influx of low/mid-level moisture from the Gulf of California. ...Central to northern Plains... Northward moisture return is expected to persist through Monday evening as a lee cyclone becomes more consolidated across the central to northern High Plains. With the primary upper-level trough displaced well to the west, synoptic-scale ascent will remain weak across the Great Plains region. However, signals for thunderstorm development within a modest warm-advection regime across ND and along the lee trough over parts of central/western KS into far northwest OK are noted in recent solutions. Predictability in either scenario is too limited to warrant risk probabilities, but the convective parameter space across both ND and KS/OK appears conducive for a conditional severe threat. ...Coastal North Carolina... A low off the Carolina coast is forecast to gradually intensify/organize over the next 72 hours, though forecast uncertainty regarding its exact evolution remains very high (see the latest NHC forecast discussion for additional details). However, a few solutions, notably recent GFS and NAM runs, suggest the low will migrate inland across the Carolinas during the day Monday. As this occurs, a narrow swath of high theta-e air will span from the NC coast into eastern NC and perhaps southeast VA. Wind profiles within this swath may feature strong low-level helicity that could support some tornado threat given sufficient buoyancy for deep convection. Confidence in this scenario remains very limited, but forecast trends will be monitored. ..Moore.. 09/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT BASIN INTO THE FOUR CORNERS REGION... ...SUMMARY... Isolated severe gusts and small to marginally severe hail will be possible on Monday afternoon to early evening across parts of the eastern Great Basin to Four Corners. ...Synopsis... The upper-level trough currently in place across the northeastern Pacific is forecast to amplify over the next 24-72 hours as it migrates southward along the West Coast and eventually into the Great Basin. As this occurs, an attendant mid-level jet streak will pivot into the interior West. The combination of increasing ascent and strengthening mid/upper-level winds will support isolated to scattered strong to severe thunderstorms across parts of the Great Basin and Four Corners. To the east across the Plains, surface pressure falls will become increasingly concentrated across the central to northern High Plains, which will maintain a moisture return regime. Weak ascent over a broadening warm sector will support isolated to widely scattered thunderstorm chances. ...Great Basin/Four Corners... Forecast guidance continues to show reasonably good agreement in strengthening wind fields across NV into UT and AZ by peak heating Monday as the mid/upper jet noses into the region. Mid-level lapse rates will steepen through the day ahead of the approaching wave, which, despite very modest moisture content, should support adequate buoyancy for convection. Deep, well-mixed boundary layers will facilitate efficient downward mixing of strong mid-level flow, which will likely be augmented by evaporatively-cooled downdraft accelerations. Consequently, the probability for strong to severe wind gusts appears higher and somewhat more concentrated compared to preceding days. Portions of the Four Corners region may also see a large hail threat given elongated wind profiles and slightly better buoyancy due to an influx of low/mid-level moisture from the Gulf of California. ...Central to northern Plains... Northward moisture return is expected to persist through Monday evening as a lee cyclone becomes more consolidated across the central to northern High Plains. With the primary upper-level trough displaced well to the west, synoptic-scale ascent will remain weak across the Great Plains region. However, signals for thunderstorm development within a modest warm-advection regime across ND and along the lee trough over parts of central/western KS into far northwest OK are noted in recent solutions. Predictability in either scenario is too limited to warrant risk probabilities, but the convective parameter space across both ND and KS/OK appears conducive for a conditional severe threat. ...Coastal North Carolina... A low off the Carolina coast is forecast to gradually intensify/organize over the next 72 hours, though forecast uncertainty regarding its exact evolution remains very high (see the latest NHC forecast discussion for additional details). However, a few solutions, notably recent GFS and NAM runs, suggest the low will migrate inland across the Carolinas during the day Monday. As this occurs, a narrow swath of high theta-e air will span from the NC coast into eastern NC and perhaps southeast VA. Wind profiles within this swath may feature strong low-level helicity that could support some tornado threat given sufficient buoyancy for deep convection. Confidence in this scenario remains very limited, but forecast trends will be monitored. ..Moore.. 09/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT BASIN INTO THE FOUR CORNERS REGION... ...SUMMARY... Isolated severe gusts and small to marginally severe hail will be possible on Monday afternoon to early evening across parts of the eastern Great Basin to Four Corners. ...Synopsis... The upper-level trough currently in place across the northeastern Pacific is forecast to amplify over the next 24-72 hours as it migrates southward along the West Coast and eventually into the Great Basin. As this occurs, an attendant mid-level jet streak will pivot into the interior West. The combination of increasing ascent and strengthening mid/upper-level winds will support isolated to scattered strong to severe thunderstorms across parts of the Great Basin and Four Corners. To the east across the Plains, surface pressure falls will become increasingly concentrated across the central to northern High Plains, which will maintain a moisture return regime. Weak ascent over a broadening warm sector will support isolated to widely scattered thunderstorm chances. ...Great Basin/Four Corners... Forecast guidance continues to show reasonably good agreement in strengthening wind fields across NV into UT and AZ by peak heating Monday as the mid/upper jet noses into the region. Mid-level lapse rates will steepen through the day ahead of the approaching wave, which, despite very modest moisture content, should support adequate buoyancy for convection. Deep, well-mixed boundary layers will facilitate efficient downward mixing of strong mid-level flow, which will likely be augmented by evaporatively-cooled downdraft accelerations. Consequently, the probability for strong to severe wind gusts appears higher and somewhat more concentrated compared to preceding days. Portions of the Four Corners region may also see a large hail threat given elongated wind profiles and slightly better buoyancy due to an influx of low/mid-level moisture from the Gulf of California. ...Central to northern Plains... Northward moisture return is expected to persist through Monday evening as a lee cyclone becomes more consolidated across the central to northern High Plains. With the primary upper-level trough displaced well to the west, synoptic-scale ascent will remain weak across the Great Plains region. However, signals for thunderstorm development within a modest warm-advection regime across ND and along the lee trough over parts of central/western KS into far northwest OK are noted in recent solutions. Predictability in either scenario is too limited to warrant risk probabilities, but the convective parameter space across both ND and KS/OK appears conducive for a conditional severe threat. ...Coastal North Carolina... A low off the Carolina coast is forecast to gradually intensify/organize over the next 72 hours, though forecast uncertainty regarding its exact evolution remains very high (see the latest NHC forecast discussion for additional details). However, a few solutions, notably recent GFS and NAM runs, suggest the low will migrate inland across the Carolinas during the day Monday. As this occurs, a narrow swath of high theta-e air will span from the NC coast into eastern NC and perhaps southeast VA. Wind profiles within this swath may feature strong low-level helicity that could support some tornado threat given sufficient buoyancy for deep convection. Confidence in this scenario remains very limited, but forecast trends will be monitored. ..Moore.. 09/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT BASIN INTO THE FOUR CORNERS REGION... ...SUMMARY... Isolated severe gusts and small to marginally severe hail will be possible on Monday afternoon to early evening across parts of the eastern Great Basin to Four Corners. ...Synopsis... The upper-level trough currently in place across the northeastern Pacific is forecast to amplify over the next 24-72 hours as it migrates southward along the West Coast and eventually into the Great Basin. As this occurs, an attendant mid-level jet streak will pivot into the interior West. The combination of increasing ascent and strengthening mid/upper-level winds will support isolated to scattered strong to severe thunderstorms across parts of the Great Basin and Four Corners. To the east across the Plains, surface pressure falls will become increasingly concentrated across the central to northern High Plains, which will maintain a moisture return regime. Weak ascent over a broadening warm sector will support isolated to widely scattered thunderstorm chances. ...Great Basin/Four Corners... Forecast guidance continues to show reasonably good agreement in strengthening wind fields across NV into UT and AZ by peak heating Monday as the mid/upper jet noses into the region. Mid-level lapse rates will steepen through the day ahead of the approaching wave, which, despite very modest moisture content, should support adequate buoyancy for convection. Deep, well-mixed boundary layers will facilitate efficient downward mixing of strong mid-level flow, which will likely be augmented by evaporatively-cooled downdraft accelerations. Consequently, the probability for strong to severe wind gusts appears higher and somewhat more concentrated compared to preceding days. Portions of the Four Corners region may also see a large hail threat given elongated wind profiles and slightly better buoyancy due to an influx of low/mid-level moisture from the Gulf of California. ...Central to northern Plains... Northward moisture return is expected to persist through Monday evening as a lee cyclone becomes more consolidated across the central to northern High Plains. With the primary upper-level trough displaced well to the west, synoptic-scale ascent will remain weak across the Great Plains region. However, signals for thunderstorm development within a modest warm-advection regime across ND and along the lee trough over parts of central/western KS into far northwest OK are noted in recent solutions. Predictability in either scenario is too limited to warrant risk probabilities, but the convective parameter space across both ND and KS/OK appears conducive for a conditional severe threat. ...Coastal North Carolina... A low off the Carolina coast is forecast to gradually intensify/organize over the next 72 hours, though forecast uncertainty regarding its exact evolution remains very high (see the latest NHC forecast discussion for additional details). However, a few solutions, notably recent GFS and NAM runs, suggest the low will migrate inland across the Carolinas during the day Monday. As this occurs, a narrow swath of high theta-e air will span from the NC coast into eastern NC and perhaps southeast VA. Wind profiles within this swath may feature strong low-level helicity that could support some tornado threat given sufficient buoyancy for deep convection. Confidence in this scenario remains very limited, but forecast trends will be monitored. ..Moore.. 09/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT BASIN INTO THE FOUR CORNERS REGION... ...SUMMARY... Isolated severe gusts and small to marginally severe hail will be possible on Monday afternoon to early evening across parts of the eastern Great Basin to Four Corners. ...Synopsis... The upper-level trough currently in place across the northeastern Pacific is forecast to amplify over the next 24-72 hours as it migrates southward along the West Coast and eventually into the Great Basin. As this occurs, an attendant mid-level jet streak will pivot into the interior West. The combination of increasing ascent and strengthening mid/upper-level winds will support isolated to scattered strong to severe thunderstorms across parts of the Great Basin and Four Corners. To the east across the Plains, surface pressure falls will become increasingly concentrated across the central to northern High Plains, which will maintain a moisture return regime. Weak ascent over a broadening warm sector will support isolated to widely scattered thunderstorm chances. ...Great Basin/Four Corners... Forecast guidance continues to show reasonably good agreement in strengthening wind fields across NV into UT and AZ by peak heating Monday as the mid/upper jet noses into the region. Mid-level lapse rates will steepen through the day ahead of the approaching wave, which, despite very modest moisture content, should support adequate buoyancy for convection. Deep, well-mixed boundary layers will facilitate efficient downward mixing of strong mid-level flow, which will likely be augmented by evaporatively-cooled downdraft accelerations. Consequently, the probability for strong to severe wind gusts appears higher and somewhat more concentrated compared to preceding days. Portions of the Four Corners region may also see a large hail threat given elongated wind profiles and slightly better buoyancy due to an influx of low/mid-level moisture from the Gulf of California. ...Central to northern Plains... Northward moisture return is expected to persist through Monday evening as a lee cyclone becomes more consolidated across the central to northern High Plains. With the primary upper-level trough displaced well to the west, synoptic-scale ascent will remain weak across the Great Plains region. However, signals for thunderstorm development within a modest warm-advection regime across ND and along the lee trough over parts of central/western KS into far northwest OK are noted in recent solutions. Predictability in either scenario is too limited to warrant risk probabilities, but the convective parameter space across both ND and KS/OK appears conducive for a conditional severe threat. ...Coastal North Carolina... A low off the Carolina coast is forecast to gradually intensify/organize over the next 72 hours, though forecast uncertainty regarding its exact evolution remains very high (see the latest NHC forecast discussion for additional details). However, a few solutions, notably recent GFS and NAM runs, suggest the low will migrate inland across the Carolinas during the day Monday. As this occurs, a narrow swath of high theta-e air will span from the NC coast into eastern NC and perhaps southeast VA. Wind profiles within this swath may feature strong low-level helicity that could support some tornado threat given sufficient buoyancy for deep convection. Confidence in this scenario remains very limited, but forecast trends will be monitored. ..Moore.. 09/14/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z The previous forecast remains generally on track. The main change to the Day 2 Fire Weather Outlook update was to add Elevated highlights to portions of the southern High Plains. Across portions of the northwestern Texas Panhandle and adjacent areas to the north, initially dry southerly surface flow (driven by lee troughing) will promote 15 mph sustained winds amid 15-20 percent RH on Sunday afternoon. Fuels in this region are modestly dry, warranting the addition of fire weather highlights. A mix of wet and dry thunderstorms is possible across portions of northeastern Nevada into Idaho during the afternoon as well. However, the marginal receptiveness of fuels, along with the wet/dry thunderstorm mix, suggests that isolated dry thunderstorm highlights are not currently needed. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Sep 14 2024/ ...Synopsis... Ahead of an amplifying large-scale trough over the West Coast, enhanced deep-layer meridional flow will overspread a diurnally deepening boundary layer (15-20 percent RH) over portions of the southern Great Basin. This, coupled with a tightening pressure gradient along the southern periphery of an evolving surface cyclone, will yield 20-25 mph sustained southerly surface winds. These winds will overlap the lowest RH over portions of southern NV, and given modestly receptive fuels here, elevated fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z The previous forecast remains generally on track. The main change to the Day 2 Fire Weather Outlook update was to add Elevated highlights to portions of the southern High Plains. Across portions of the northwestern Texas Panhandle and adjacent areas to the north, initially dry southerly surface flow (driven by lee troughing) will promote 15 mph sustained winds amid 15-20 percent RH on Sunday afternoon. Fuels in this region are modestly dry, warranting the addition of fire weather highlights. A mix of wet and dry thunderstorms is possible across portions of northeastern Nevada into Idaho during the afternoon as well. However, the marginal receptiveness of fuels, along with the wet/dry thunderstorm mix, suggests that isolated dry thunderstorm highlights are not currently needed. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Sep 14 2024/ ...Synopsis... Ahead of an amplifying large-scale trough over the West Coast, enhanced deep-layer meridional flow will overspread a diurnally deepening boundary layer (15-20 percent RH) over portions of the southern Great Basin. This, coupled with a tightening pressure gradient along the southern periphery of an evolving surface cyclone, will yield 20-25 mph sustained southerly surface winds. These winds will overlap the lowest RH over portions of southern NV, and given modestly receptive fuels here, elevated fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z The previous forecast remains generally on track. The main change to the Day 2 Fire Weather Outlook update was to add Elevated highlights to portions of the southern High Plains. Across portions of the northwestern Texas Panhandle and adjacent areas to the north, initially dry southerly surface flow (driven by lee troughing) will promote 15 mph sustained winds amid 15-20 percent RH on Sunday afternoon. Fuels in this region are modestly dry, warranting the addition of fire weather highlights. A mix of wet and dry thunderstorms is possible across portions of northeastern Nevada into Idaho during the afternoon as well. However, the marginal receptiveness of fuels, along with the wet/dry thunderstorm mix, suggests that isolated dry thunderstorm highlights are not currently needed. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Sep 14 2024/ ...Synopsis... Ahead of an amplifying large-scale trough over the West Coast, enhanced deep-layer meridional flow will overspread a diurnally deepening boundary layer (15-20 percent RH) over portions of the southern Great Basin. This, coupled with a tightening pressure gradient along the southern periphery of an evolving surface cyclone, will yield 20-25 mph sustained southerly surface winds. These winds will overlap the lowest RH over portions of southern NV, and given modestly receptive fuels here, elevated fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z The previous forecast remains generally on track. The main change to the Day 2 Fire Weather Outlook update was to add Elevated highlights to portions of the southern High Plains. Across portions of the northwestern Texas Panhandle and adjacent areas to the north, initially dry southerly surface flow (driven by lee troughing) will promote 15 mph sustained winds amid 15-20 percent RH on Sunday afternoon. Fuels in this region are modestly dry, warranting the addition of fire weather highlights. A mix of wet and dry thunderstorms is possible across portions of northeastern Nevada into Idaho during the afternoon as well. However, the marginal receptiveness of fuels, along with the wet/dry thunderstorm mix, suggests that isolated dry thunderstorm highlights are not currently needed. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Sep 14 2024/ ...Synopsis... Ahead of an amplifying large-scale trough over the West Coast, enhanced deep-layer meridional flow will overspread a diurnally deepening boundary layer (15-20 percent RH) over portions of the southern Great Basin. This, coupled with a tightening pressure gradient along the southern periphery of an evolving surface cyclone, will yield 20-25 mph sustained southerly surface winds. These winds will overlap the lowest RH over portions of southern NV, and given modestly receptive fuels here, elevated fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z The previous forecast remains generally on track. The main change to the Day 2 Fire Weather Outlook update was to add Elevated highlights to portions of the southern High Plains. Across portions of the northwestern Texas Panhandle and adjacent areas to the north, initially dry southerly surface flow (driven by lee troughing) will promote 15 mph sustained winds amid 15-20 percent RH on Sunday afternoon. Fuels in this region are modestly dry, warranting the addition of fire weather highlights. A mix of wet and dry thunderstorms is possible across portions of northeastern Nevada into Idaho during the afternoon as well. However, the marginal receptiveness of fuels, along with the wet/dry thunderstorm mix, suggests that isolated dry thunderstorm highlights are not currently needed. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Sep 14 2024/ ...Synopsis... Ahead of an amplifying large-scale trough over the West Coast, enhanced deep-layer meridional flow will overspread a diurnally deepening boundary layer (15-20 percent RH) over portions of the southern Great Basin. This, coupled with a tightening pressure gradient along the southern periphery of an evolving surface cyclone, will yield 20-25 mph sustained southerly surface winds. These winds will overlap the lowest RH over portions of southern NV, and given modestly receptive fuels here, elevated fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 PM CDT Sat Sep 14 2024 Valid 151200Z - 161200Z The previous forecast remains generally on track. The main change to the Day 2 Fire Weather Outlook update was to add Elevated highlights to portions of the southern High Plains. Across portions of the northwestern Texas Panhandle and adjacent areas to the north, initially dry southerly surface flow (driven by lee troughing) will promote 15 mph sustained winds amid 15-20 percent RH on Sunday afternoon. Fuels in this region are modestly dry, warranting the addition of fire weather highlights. A mix of wet and dry thunderstorms is possible across portions of northeastern Nevada into Idaho during the afternoon as well. However, the marginal receptiveness of fuels, along with the wet/dry thunderstorm mix, suggests that isolated dry thunderstorm highlights are not currently needed. ..Squitieri.. 09/14/2024 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Sep 14 2024/ ...Synopsis... Ahead of an amplifying large-scale trough over the West Coast, enhanced deep-layer meridional flow will overspread a diurnally deepening boundary layer (15-20 percent RH) over portions of the southern Great Basin. This, coupled with a tightening pressure gradient along the southern periphery of an evolving surface cyclone, will yield 20-25 mph sustained southerly surface winds. These winds will overlap the lowest RH over portions of southern NV, and given modestly receptive fuels here, elevated fire-weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more