SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Fri Sep 06 2024 Valid 081200Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms will be possible on Sunday in parts of the Southeast, western states and Great Lakes. No severe weather is expected. ...DISCUSSION... An upper-level trough is forecast to move through the Ohio and Tennessee Valleys on Sunday, as a front remains located over the central and eastern Gulf Coast states. Thunderstorms will be possible on Sunday near and to the south of the front. Thunderstorms will also be possible within southwest mid-level flow to the west of a ridge in the western U.S. Isolated thunderstorms may also occur in north-northwesterly mid-level flow over parts of the Great Lakes. No severe threat is expected across the U.S. on Sunday or Sunday night. ..Broyles.. 09/06/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0153 AM CDT Fri Sep 06 2024 Valid 071200Z - 081200Z ...Synopsis... As the weak Pacific trough continues inland, additional mid-level moisture will advect onshore over portions of the northern Sierra and Cascades through the weekend. The upper ridge will continue to slowly weaken, allowing for isolated thunderstorms over the Northwest. Thunderstorms are likely across portions of the Cascades in OR and southern WA, across the Sierra, and into portions of southern CA. Hot and well-mixed boundary-layer profiles will likely support low precipitation efficiency, especially with storm motions greater than 20 kt. Confidence in dry thunderstorm coverage is greatest across portions of the central Cascades, though drier storms will also be possible, albeit less certain, across the northern Sierra and parts of southern CA. Given the risk for lightning atop dry fuels, an IsoDryT area has been added where storm coverage and confidence in lightning atop dry fuels is highest. In addition to the risk for lightning, increasingly strong southwesterly flow aloft is expected to support gusty downslope winds over parts of northern CA and northwest NV. Gusty winds of 15-20 mph in the lee of the Sierra are likely to overlap with afternoon RH values below 20%. With receptive fuels and at least a few hours of dry and breezy conditions possible, elevated fire-weather conditions are likely. ..Lyons.. 09/06/2024 ...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 0153 AM CDT Fri Sep 06 2024 Valid 071200Z - 081200Z ...Synopsis... As the weak Pacific trough continues inland, additional mid-level moisture will advect onshore over portions of the northern Sierra and Cascades through the weekend. The upper ridge will continue to slowly weaken, allowing for isolated thunderstorms over the Northwest. Thunderstorms are likely across portions of the Cascades in OR and southern WA, across the Sierra, and into portions of southern CA. Hot and well-mixed boundary-layer profiles will likely support low precipitation efficiency, especially with storm motions greater than 20 kt. Confidence in dry thunderstorm coverage is greatest across portions of the central Cascades, though drier storms will also be possible, albeit less certain, across the northern Sierra and parts of southern CA. Given the risk for lightning atop dry fuels, an IsoDryT area has been added where storm coverage and confidence in lightning atop dry fuels is highest. In addition to the risk for lightning, increasingly strong southwesterly flow aloft is expected to support gusty downslope winds over parts of northern CA and northwest NV. Gusty winds of 15-20 mph in the lee of the Sierra are likely to overlap with afternoon RH values below 20%. With receptive fuels and at least a few hours of dry and breezy conditions possible, elevated fire-weather conditions are likely. ..Lyons.. 09/06/2024 ...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 0151 AM CDT Fri Sep 06 2024 Valid 061200Z - 071200Z ...Synopsis... Mid-level ridging centered over the Great Basin is forecast to slowly decay today as a weak upper trough approaches the Pacific Coast. Ahead of the weak trough, a modest influx of mid-level moisture and ascent will overspread the northern Sierra and southern Cascades. Adequate buoyancy will develop with daytime heating supporting isolated thunderstorms through the evening hours. Beneath the advancing mid-level moisture, dry boundary-layer profiles and storm motions of 20-25 kt will favor low to very low rainfall efficiency with these storms. With thunderstorms expected atop areas of receptive fuels, dry lightning appears probable. Additionally, strengthening southwesterly mid-level flow should enhance downslope winds and low relative humidity across northern CA into northwest NV. Areas of brief elevated fire weather conditions are possible, though the duration and coverage should remain limited. ..Lyons.. 09/06/2024 ...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 0151 AM CDT Fri Sep 06 2024 Valid 061200Z - 071200Z ...Synopsis... Mid-level ridging centered over the Great Basin is forecast to slowly decay today as a weak upper trough approaches the Pacific Coast. Ahead of the weak trough, a modest influx of mid-level moisture and ascent will overspread the northern Sierra and southern Cascades. Adequate buoyancy will develop with daytime heating supporting isolated thunderstorms through the evening hours. Beneath the advancing mid-level moisture, dry boundary-layer profiles and storm motions of 20-25 kt will favor low to very low rainfall efficiency with these storms. With thunderstorms expected atop areas of receptive fuels, dry lightning appears probable. Additionally, strengthening southwesterly mid-level flow should enhance downslope winds and low relative humidity across northern CA into northwest NV. Areas of brief elevated fire weather conditions are possible, though the duration and coverage should remain limited. ..Lyons.. 09/06/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Fri Sep 06 2024 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms will be possible on Saturday in parts of the southwestern states, the Pacific Northwest and from the Southeast northward to the lower Great Lakes. No severe weather is expected. ...DISCUSSION... An upper-level low will move eastward across southeast Canada on Saturday, as an associated mid-level trough moves into the central Appalachians. At the surface, a cold front will advance southeastward across the Mid-Atlantic, Carolinas and Southeast. Ahead of the front, scattered thunderstorms will likely develop as a moist airmass heats up during the day. Additional storms will be possible on Saturday in the vicinity of a large area of mid-level high pressure located over the southwestern U.S. A few strikes may also occur near the Interstate-5 corridor in western Washington southward into the Willamette Valley. ..Broyles.. 09/06/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Fri Sep 06 2024 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY REGION... ...SUMMARY... Strong to locally severe storms are possible this afternoon across much of Ohio and adjacent portions of the Great Lakes and Ohio Valley. ...Ohio Valley Region... Seasonally strong upper trough is currently located over northwestern ON/upper MS Valley, digging southeast toward the Great Lakes. Leading edge of strong 12hr mid-level height falls will overspread the OH Valley this afternoon as a 500mb speed max translates across MN/IA into northern IL/IN. Pronounced surface front will advance into central OH, arcing southwest into western KY by 18z, and this boundary will serve as the focus for potentially robust convection this afternoon. Latest model guidance suggests strong boundary-layer heating ahead of the front which should result in SBCAPE in excess of 1000 J/kg as temperatures rise to near 80F. Current thinking is scattered storms should readily develop by mid day as convective temperatures are breached, aided by frontal forcing. Modest 0-6km bulk shear suggests some potential for organization, but lapse rates will not be that steep, and this should limit updraft strength. Even so, some risk for locally damaging winds, and perhaps some hail will exist with the strongest storms. The primary window for severe will be between 06/18-07/00z. ..Darrow/Lyons.. 09/06/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 PM CDT Thu Sep 05 2024 Valid 060100Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE SOUTHERN ROCKIES... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will remain possible through mid evening across parts of the southern Rockies. ...01z Update... Notable mid-level short-wave trough, currently located over southern CO, is digging south-southeast in line with latest model guidance. This feature is forecast to progress into southern NM by the end of the period. Scattered robust convection has developed ahead of this feature which has produced several severe wind gusts over the last few hours. 00z sounding from ABQ exhibited a dry adiabatic lapse rate in the lowest 3km, with steep mid-level lapse rates. While PW values are not particularly high, adequate moisture is available for efficient downbursts. Over the next few hours, scattered strong/locally severe storms will propagate toward southern NM with an attendant risk for severe gusts, or even marginally severe hail. However, boundary-layer cooling should lead to weakening updrafts in the next few hours and the severe threat will lessen markedly after 03-04z. ..Darrow.. 09/06/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 PM CDT Thu Sep 05 2024 Valid 060100Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE SOUTHERN ROCKIES... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will remain possible through mid evening across parts of the southern Rockies. ...01z Update... Notable mid-level short-wave trough, currently located over southern CO, is digging south-southeast in line with latest model guidance. This feature is forecast to progress into southern NM by the end of the period. Scattered robust convection has developed ahead of this feature which has produced several severe wind gusts over the last few hours. 00z sounding from ABQ exhibited a dry adiabatic lapse rate in the lowest 3km, with steep mid-level lapse rates. While PW values are not particularly high, adequate moisture is available for efficient downbursts. Over the next few hours, scattered strong/locally severe storms will propagate toward southern NM with an attendant risk for severe gusts, or even marginally severe hail. However, boundary-layer cooling should lead to weakening updrafts in the next few hours and the severe threat will lessen markedly after 03-04z. ..Darrow.. 09/06/2024 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0352 PM CDT Thu Sep 05 2024 Valid 071200Z - 131200Z High pressure will continue to build in across the western US through D3/Saturday. Thunderstorm activity will be minimal across the Southwest as Monsoonal moisture has gradually shifted southward. Temperatures across the west will climb to above normal, but winds will remain mostly light where fuels are the driest in the west. The aforementioned hot, dry, unstable conditions will lead to some increase in fire behavior. A return of isolated dry thunderstorm activity is expected D3/Saturday across the Pacific Northwest as a trough approaches from the Pacific and precipitable water values steadily increase. Isolated dry thunder probabilities were maintained on D3/Saturday, where signal for thunderstorms is highest in CAM guidance and ensemble output. Monsoonal moisture will slowly begin to return northward across the Southwest by D4/Sunday-D7/Wednesday. A few areas of isolated dry thunderstorms will be possible across northern Arizona into southern Utah. Fuels in this region are drying, with further warming and drying is expected through the early extended and status of fuels will be reevaluated for future outlooks. The Pacific trough will deepen and move through D4/Sunday-D8 /Thursday, bringing enhanced westerly flow across northern California, the Pacific Northwest, and into the Great Basin. This will lead to multiple rounds of potential for Elevated to Critical conditions. Considerable differences in the speed and timing of this trough lead to uncertainty in where these conditions will occur and when. For now 40 percent probabilities were included across portions of northern California, western Nevada, and southern Oregon, and into portions of western/central Idaho. These areas may need to be adjusted with better model consensus. Given the dry lightning risk on D1/Thursday, hold over fires will be a concern should winds speeds increase. ..Thornton.. 09/05/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Thu Sep 05 2024 Valid 052000Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTH-CENTRAL COLORADO INTO NORTHERN/CENTRAL NEW MEXICO... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will be possible today across parts of far south-central Colorado into northern/central New Mexico. ...20Z Update... The forecast remains on track, and with the exception of minor trimming of General Thunder in parts of the Midwest (where instability has weakened substantially), no appreciable changes were made with this update. The severe threat will gradually increase across portions of the southern Rockies and adjacent High Plains through the afternoon, where isolated instances of hail and sporadic severe wind gusts will be possible. For details, see MCD #2048. ..Weinman.. 09/05/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Thu Sep 05 2024/ ...Synopsis... Satellite imagery shows a shortwave trough moving southeastward through the central Rockies, between the upper ridging in place over the western Great Basin and the broad upper troughing across central Canadian and northern Plains/Upper MS Valley. Another shortwave trough exists over the Upper MS Valley. This shortwave trough is forecast to continue progressing eastward through the base broad central Canada/northern Plains trough, moving across the Upper Great Lakes and into eastern Ontario. Recent surface analysis places a surface low associated with this shortwave over Lake Superior, with a cold front extending southwestward from this low through KS and into northeast NM. This front is forecast to progress southward/southeastward as its parent surface low lifts northeastward. Isolated thunderstorms are possible along this frontal boundary, but overall severity should be mitigated by modest buoyancy and vertical shear. Greater thunderstorm coverage and severity is anticipated over the southern Rockies as the previously mentioned central Rockies shortwave trough continues southeastward and promotes thunderstorm development. Lastly, a tropical wave just off the TX Coast is contributing to abundant moisture across much of Gulf Coast, with low 70s dewpoints reaching into much of east TX and northern LA, and upper 70s across FL. Precipitable water values over 2" cover much of this region as well. Heavy rain is the primary threat (as indicated by the latest Day 1 Excessive Rainfall Outlook from WPC), but a few water-loaded downbursts capable of damaging gusts are possible from southeast TX and southern/central LA eastward along the Gulf Coast and over the Florida Peninsula. Coverage of these gusts is expected to be sparse and too low to delineate a 5% wind probability area. ...Southern Rockies/southern High Plains... Moderate low-level moisture is anticipated within the post-frontal airmass across the southern Rockies and adjacent southern High Plains this afternoon, characterized by dewpoints in the low to mid 50s across the High Plains and upper 40s across the higher terrain. Even with this modest moisture, the airmass is expected to destabilize, fostered by deep boundary-layer mixing and cool temperatures aloft (i.e. around -10 deg C at 500 mb). Surface easterlies/northeasterlies beneath modest westerlies aloft will contribute to effective bulk shear around 35 kt, which is strong enough for some updraft organization. Isolated hail is possible across the higher terrain with the initially more cellular development. Damaging gusts are expected to be the primary risk thereafter as storms trend towards a more clustered mode and move eastward into the more mixed southern High Plains. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Thu Sep 05 2024 Valid 052000Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTH-CENTRAL COLORADO INTO NORTHERN/CENTRAL NEW MEXICO... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will be possible today across parts of far south-central Colorado into northern/central New Mexico. ...20Z Update... The forecast remains on track, and with the exception of minor trimming of General Thunder in parts of the Midwest (where instability has weakened substantially), no appreciable changes were made with this update. The severe threat will gradually increase across portions of the southern Rockies and adjacent High Plains through the afternoon, where isolated instances of hail and sporadic severe wind gusts will be possible. For details, see MCD #2048. ..Weinman.. 09/05/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Thu Sep 05 2024/ ...Synopsis... Satellite imagery shows a shortwave trough moving southeastward through the central Rockies, between the upper ridging in place over the western Great Basin and the broad upper troughing across central Canadian and northern Plains/Upper MS Valley. Another shortwave trough exists over the Upper MS Valley. This shortwave trough is forecast to continue progressing eastward through the base broad central Canada/northern Plains trough, moving across the Upper Great Lakes and into eastern Ontario. Recent surface analysis places a surface low associated with this shortwave over Lake Superior, with a cold front extending southwestward from this low through KS and into northeast NM. This front is forecast to progress southward/southeastward as its parent surface low lifts northeastward. Isolated thunderstorms are possible along this frontal boundary, but overall severity should be mitigated by modest buoyancy and vertical shear. Greater thunderstorm coverage and severity is anticipated over the southern Rockies as the previously mentioned central Rockies shortwave trough continues southeastward and promotes thunderstorm development. Lastly, a tropical wave just off the TX Coast is contributing to abundant moisture across much of Gulf Coast, with low 70s dewpoints reaching into much of east TX and northern LA, and upper 70s across FL. Precipitable water values over 2" cover much of this region as well. Heavy rain is the primary threat (as indicated by the latest Day 1 Excessive Rainfall Outlook from WPC), but a few water-loaded downbursts capable of damaging gusts are possible from southeast TX and southern/central LA eastward along the Gulf Coast and over the Florida Peninsula. Coverage of these gusts is expected to be sparse and too low to delineate a 5% wind probability area. ...Southern Rockies/southern High Plains... Moderate low-level moisture is anticipated within the post-frontal airmass across the southern Rockies and adjacent southern High Plains this afternoon, characterized by dewpoints in the low to mid 50s across the High Plains and upper 40s across the higher terrain. Even with this modest moisture, the airmass is expected to destabilize, fostered by deep boundary-layer mixing and cool temperatures aloft (i.e. around -10 deg C at 500 mb). Surface easterlies/northeasterlies beneath modest westerlies aloft will contribute to effective bulk shear around 35 kt, which is strong enough for some updraft organization. Isolated hail is possible across the higher terrain with the initially more cellular development. Damaging gusts are expected to be the primary risk thereafter as storms trend towards a more clustered mode and move eastward into the more mixed southern High Plains. Read more

No watches are valid as of Thu Sep 5 19:58:01 UTC 2024.

MD 2048 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST NEW MEXICO AND VICINITY
Mesoscale Discussion 2048 NWS Storm Prediction Center Norman OK 0148 PM CDT Thu Sep 05 2024 Areas affected...northeast New Mexico and vicinity Concerning...Severe potential...Watch unlikely Valid 051848Z - 052045Z Probability of Watch Issuance...5 percent SUMMARY...A few strong to severe storms are possible this afternoon across northeast New Mexico. DISCUSSION...A few thunderstorms developed this morning and have continued into the early afternoon ahead of the southward moving mid-level shortwave trough across Colorado. These storms have been sub-severe thus far with a maximum wind gust of 38 knots measured at Taos, NM. However, surface heating is destabilizing the airmass ahead of this storm activity and inhibition is forecast to eventually erode. Once this occurs, more robust convection is anticipated with the potential for some multicell/occasional supercell structures. Through time, these storms may congeal into one or more clusters with an increasing threat for sporadic severe wind gusts into the early evening. Any severe-weather threat which does materialize should subside near sunset as the boundary layer cools and inhibition increases. ..Bentley/Mosier.. 09/05/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABQ... LAT...LON 36500575 36970490 36940399 35760341 34950326 34370341 34010389 34150469 34350511 35260559 36090596 36500575 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z Only minor adjustments were made to the isolated dry thunderstorm area along the Oregon Coast in line with recent model trends. Otherwise, the outlook remains on track. See previous discussion below. ..Thornton.. 09/05/2024 .PREV DISCUSSION... /ISSUED 1213 AM CDT Thu Sep 05 2024/ ...Synopsis... Isolated dry thunderstorms will be the primary fire weather concern for Friday across parts of the northern Sierra Nevada into southwest OR. Recent water-vapor imagery reveals a weak upper disturbance over the eastern Pacific on the fringe of the upper ridge over the western U.S. This feature is expected to drift east/northeast over the next 48 hours, reaching northern CA/southern OR by late afternoon/evening Friday. As this occurs, a modest influx of mid-level moisture and ascent-driven mid-level cooling over the northern Sierra Nevada and southern Cascades should support adequate buoyancy for isolated thunderstorms. Recent forecast soundings suggest that boundary layer conditions will be sufficiently dry for dry lightning strikes, which will pose a fire weather concern given the dry fuels over the region (ERCs generally at or above the 80th percentile). Thunderstorms will be most likely along and to the lee side of the northern Sierra Nevada and southern Cascades where orographic ascent will aid in convective initiation. Additionally, strengthening southwesterly mid-level flow should enhance downslope winds across northern CA into northwest NV. Areas of elevated fire weather conditions are possible (and will most likely occur within the dry-thunderstorm risk area, but ensemble confidence in the coverage and duration of these conditions is somewhat limited (around 30-40% probability for sustained elevated conditions based on latest ensemble guidance). ...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 0249 PM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z Only minor adjustments were made to the isolated dry thunderstorm area along the Oregon Coast in line with recent model trends. Otherwise, the outlook remains on track. See previous discussion below. ..Thornton.. 09/05/2024 .PREV DISCUSSION... /ISSUED 1213 AM CDT Thu Sep 05 2024/ ...Synopsis... Isolated dry thunderstorms will be the primary fire weather concern for Friday across parts of the northern Sierra Nevada into southwest OR. Recent water-vapor imagery reveals a weak upper disturbance over the eastern Pacific on the fringe of the upper ridge over the western U.S. This feature is expected to drift east/northeast over the next 48 hours, reaching northern CA/southern OR by late afternoon/evening Friday. As this occurs, a modest influx of mid-level moisture and ascent-driven mid-level cooling over the northern Sierra Nevada and southern Cascades should support adequate buoyancy for isolated thunderstorms. Recent forecast soundings suggest that boundary layer conditions will be sufficiently dry for dry lightning strikes, which will pose a fire weather concern given the dry fuels over the region (ERCs generally at or above the 80th percentile). Thunderstorms will be most likely along and to the lee side of the northern Sierra Nevada and southern Cascades where orographic ascent will aid in convective initiation. Additionally, strengthening southwesterly mid-level flow should enhance downslope winds across northern CA into northwest NV. Areas of elevated fire weather conditions are possible (and will most likely occur within the dry-thunderstorm risk area, but ensemble confidence in the coverage and duration of these conditions is somewhat limited (around 30-40% probability for sustained elevated conditions based on latest ensemble guidance). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Thu Sep 05 2024 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the USA on Saturday. ...Synopsis and Discussion... An upper low will exist over the Great Lakes, and will slowly move into the Northeast while deepening. Low pressure will shift northward across western Quebec, with a cold front trailing south into the Mid Atlantic region. Behind this system, high pressure will exist into the Plains and MS Valley. Although winds aloft will increase over the Northeast as the upper low nears, low-level wind speeds, when combined with expected instability levels, do not appear to warrant severe probabilities. ...Northeast... A band of showers and a few thunderstorms is forecast to move east across NY and PA during the day, and into New England after about 00Z. Forecast soundings ahead of the cold front depict minimal instability as high temperatures only reach the upper 60s F to lower 70s F in many areas. In addition, wind speeds in the lowest few km AGL will not be particularly strong either, with less than 30 kt at 850 mb. Therefore, the combination of a relatively shallow/cool boundary layer, combined with modest wind speeds, and lack of appreciable instability, all suggest severe weather is unlikely. ..Jewell.. 09/05/2024 Read more

No Mesoscale Discussions are in effect as of Thu Sep 5 17:23:02 UTC 2024.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF OHIO AND PARTS OF ADJACENT STATES... ...SUMMARY... Strong to locally severe storms are possible on Friday across much of Ohio and adjacent portions of the Great Lakes and Ohio Valley. ...Synopsis... A large upper trough will deepen on Friday as it moves from the upper MS Valley across the Great Lakes. The primary speed max will dive southeastward across MN/IA during the day and round the base of the trough into IL, IN, OH and toward Lake Erie into Saturday morning. Meanwhile, modest upper ridging will exist across the West with weak flow. At the surface, a cold front will stretch from near Lake Erie southwestward toward the OH Valley during the afternoon with a surface low developing from Lake Ontario into far southwest Quebec late. Otherwise, the pre-frontal trough will be relatively weak during the day. ...OH and Vicinity... Daytime heating will lead to steepening lapse rates, with a plume of 60s F dewpoints likely east of the cold front. Forecast soundings show in excess of 1000 J/kg MUCAPE. While low-level lapse rates will become steep, most of the cooling aloft will be post frontal, and not contribute appreciably to destabilization across the warm sector. Increasing frontal ascent into the uncapped air mass will lead to scattered storms after about 18Z, from far western NY into parts of KY. The most favorable combination of instability and wind profiles appears to be over OH, with sufficiently long hodographs to support hail in some of the storms. Cellular storm mode is expected early, with the undercutting cold front supporting a transition to linear. As such, marginal hail and then wind gusts will be possible through about 02Z, when storms are expected to dissipate with the loss of heating. ..Jewell.. 09/05/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF OHIO AND PARTS OF ADJACENT STATES... ...SUMMARY... Strong to locally severe storms are possible on Friday across much of Ohio and adjacent portions of the Great Lakes and Ohio Valley. ...Synopsis... A large upper trough will deepen on Friday as it moves from the upper MS Valley across the Great Lakes. The primary speed max will dive southeastward across MN/IA during the day and round the base of the trough into IL, IN, OH and toward Lake Erie into Saturday morning. Meanwhile, modest upper ridging will exist across the West with weak flow. At the surface, a cold front will stretch from near Lake Erie southwestward toward the OH Valley during the afternoon with a surface low developing from Lake Ontario into far southwest Quebec late. Otherwise, the pre-frontal trough will be relatively weak during the day. ...OH and Vicinity... Daytime heating will lead to steepening lapse rates, with a plume of 60s F dewpoints likely east of the cold front. Forecast soundings show in excess of 1000 J/kg MUCAPE. While low-level lapse rates will become steep, most of the cooling aloft will be post frontal, and not contribute appreciably to destabilization across the warm sector. Increasing frontal ascent into the uncapped air mass will lead to scattered storms after about 18Z, from far western NY into parts of KY. The most favorable combination of instability and wind profiles appears to be over OH, with sufficiently long hodographs to support hail in some of the storms. Cellular storm mode is expected early, with the undercutting cold front supporting a transition to linear. As such, marginal hail and then wind gusts will be possible through about 02Z, when storms are expected to dissipate with the loss of heating. ..Jewell.. 09/05/2024 Read more