SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Sun Sep 29 2024 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis/Discussion... A highly amplified, slow-moving, mid/upper-level pattern will persist over much of the CONUS, south of a progressive northern stream near and north of the Canadian border. A norther-stream trough, nearly synoptic in scale, is apparent in moisture-channel imagery from central/southwestern BC to near-coastal WA/OR. This feature should amplify and move eastward across southwestern Canada and the interior Northwest through the period, reaching east- central/south-central SK, central MT and western WY by 12Z tomorrow. Weak, basal height falls and modest midlevel moisture will contribute to the potential for isolated, high-based convection over portions of UT, some of which may extend deep enough to generate lighting and strong gusts, into a deeply mixed boundary layer. Weak moisture/buoyancy (MLCAPE generally less than 100 J/kg) precludes an unconditional severe area. As the northern-stream trough moves away from CA, a formerly cut-off low now moving ashore into south-central CA will become cut off again, and drift southward/southwestward back toward the Pacific by the end of the period. Ridging will weaken greatly over the northern Plains and Upper Midwest ahead of the northern-stream trough, but will persist at its root over the Four Corners region. To its east, a longstanding, stacked, gradually filling cyclone will drift erratically eastward over the TN/KY border area, possibly devolving into an open-wave trough by the end of the period. Associated convection to its east will encounter a relatively warm/ stable layer in mid/upper levels, limiting but not entirely suppressing potential for convection to reach into icing layers suitable for lightning. As such, isolated thunder will be possible from the central Appalachians to the Tidewater. Although warm midlevels will extend southward to most of FL, rich boundary-layer moisture/theta-e south of a quasistationary frontal zone over northern FL will support sporadic thunderstorm potential, mainly from midday through early evening. ..Edwards/Broyles.. 09/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Sun Sep 29 2024 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis/Discussion... A highly amplified, slow-moving, mid/upper-level pattern will persist over much of the CONUS, south of a progressive northern stream near and north of the Canadian border. A norther-stream trough, nearly synoptic in scale, is apparent in moisture-channel imagery from central/southwestern BC to near-coastal WA/OR. This feature should amplify and move eastward across southwestern Canada and the interior Northwest through the period, reaching east- central/south-central SK, central MT and western WY by 12Z tomorrow. Weak, basal height falls and modest midlevel moisture will contribute to the potential for isolated, high-based convection over portions of UT, some of which may extend deep enough to generate lighting and strong gusts, into a deeply mixed boundary layer. Weak moisture/buoyancy (MLCAPE generally less than 100 J/kg) precludes an unconditional severe area. As the northern-stream trough moves away from CA, a formerly cut-off low now moving ashore into south-central CA will become cut off again, and drift southward/southwestward back toward the Pacific by the end of the period. Ridging will weaken greatly over the northern Plains and Upper Midwest ahead of the northern-stream trough, but will persist at its root over the Four Corners region. To its east, a longstanding, stacked, gradually filling cyclone will drift erratically eastward over the TN/KY border area, possibly devolving into an open-wave trough by the end of the period. Associated convection to its east will encounter a relatively warm/ stable layer in mid/upper levels, limiting but not entirely suppressing potential for convection to reach into icing layers suitable for lightning. As such, isolated thunder will be possible from the central Appalachians to the Tidewater. Although warm midlevels will extend southward to most of FL, rich boundary-layer moisture/theta-e south of a quasistationary frontal zone over northern FL will support sporadic thunderstorm potential, mainly from midday through early evening. ..Edwards/Broyles.. 09/29/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CDT Sun Sep 29 2024 Valid 021200Z - 071200Z ...DISCUSSION... Zonal flow aloft is expected to persist into late next week across the CONUS. The upper-level jet will be displaced northward to near and along the Canadian border. As successive shortwave troughs move through that zone of stronger flow, cooler/drier air will move southward into much of the Plains and parts of the Midwest/Northeast. By next weekend, there is some potential for some upper-level flow amplification with a ridge developing in the West and shortwave troughs moving into the eastern third of the CONUS. However, models remain rather divergent in their exact depiction of this evolution (the ECMWF deterministic/ensemble is more amplified than its GFS counterparts). Further increasing uncertainty, the degree of moisture return ahead of any potential shortwave trough is questionable given the expected frontal progression to along/near the Gulf Coast. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CDT Sun Sep 29 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Tuesday. ...Synopsis... A weak mid-level shortwave trough will move offshore in the Mid-Atlantic on Tuesday. Isolated thunderstorms may occur in far eastern North Carolina during the afternoon before the trough departs. A more substantial upper-level trough will move through the upper Great Lakes region by early/mid afternoon. This trough will push a surface cold front through much of the Midwest and Ohio Valley regions. Dewpoints ahead of the cold front are forecast to be in the low 60s F. Lingering effects of ridging aloft are evident in forecast soundings. However, where mid-level ascent is greatest, some thunderstorm activity is possible along the front in eastern Lower Michigan into parts of northern/central Ohio. Some gusty winds could occur with this activity, but weak low-level winds and the mentioned thermodynamic weaknesses should preclude severe weather potential. The highest coverage of thunderstorms is most likely within the Florida Peninsula as the moist airmass heats during the day and sea breeze boundaries provide lift. ..Wendt.. 09/29/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Sun Sep 29 2024 Valid 301200Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND NORTHERN NEBRASKA... ...Synopsis... A southeastward-moving cold front will bring elevated to critical fire-weather conditions to the central and northern Great Plains. Gusty winds of 20-25 MPH will coincide with post-frontal boundary-layer relative humidity values of 10-15% across much of South Dakota into Nebraska and northern Kansas. These conditions will overlap with ERC fuels that exceed the 98th annual percentile, and warm/dry conditions expected the preceding day. A Critical highlight area was introduced where the greatest confidence in persistent dry and windy conditions will occur, though additional adjustments and expansions may be needed as frontal timing and speed come into clearer focus. ..Halbert.. 09/29/2024 ...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 1228 AM CDT Sun Sep 29 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWESTERN NEBRASKA...WEST-CENTRAL SOUTH DAKOTA...AND SOUTHERN NORTH DAKOTA... ...Synopsis... Elevated to critical fire-weather conditions are expected across much of the Intermountain West into the northern Great Plains as a progressive mid-level trough traverses the Canadian prairies. The deepening surface cyclone and tightening surface pressure gradients associated with this trough will result in widespread dry and windy conditions over receptive fuels. A narrow Critical area has been maintained where the highest confidence in 20-25 MPH winds and relative humidity values below 15% are expected to overlap with ERC fuels exceeding the 95th annual percentiles. Portions of central and eastern Wyoming may also experience locally critical conditions, though confidence in the magnitude and spatial extent of surface winds precludes Critical highlights at this time. Further west, elevated fire-weather conditions are expected across central and eastern Nevada into western Utah, as well as portions of Columbia River Basin in Washington. Winds in the Columbia River Basin could be as high as 20-25 MPH, but forecast guidance shows significant spread in the forecast boundary-layer relative humidity values (15-25%). Across the Great Basin, winds will generally remain in the 15-20 MPH range with relative humidity values of 10-15%. ..Halbert.. 09/29/2024 ...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 1153 PM CDT Sat Sep 28 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... A weakening, positively-tilted upper trough will continue eastward in the central/southern Appalachians on Monday. On the southern flank of this trough, mid-level winds will remain modestly enhanced from Georgia into parts of the eastern Carolinas. Thermodynamic profiles across the region suggest convection should remain rather shallow due to warmer temperatures at mid/upper levels. This will particularly be the case with northern/western extent closer to the remnant upper level circulation. A few deeper updrafts are possible near the eastern coast of North Carolina. Despite adequate shear, weak lapse rates aloft and minimal forcing for ascent will limit potential for severe storms. Across the Florida Peninsula, a moist airmass will remain in place. Daytime heating and ascent along the sea breeze boundary will promote isolated to scattered storm development during the afternoon. Weak shear will limit severe potential, however. Though limited, mid-level moisture within the upper-level ridge will allow isolated thunderstorms to develop within the higher terrain in the Four Corners vicinity. Slightly greater coverage may be realized in central Colorado where PWAT values are forecast to be higher. ..Wendt.. 09/29/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1152 PM CDT Sat Sep 28 2024 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast for today. ...Synopsis... A positive-tilt upper trough will stretch from the lower MS Valley into the Northeast today, with a weakening upper low over KY. To the west, an upper ridge will extend from the Four Corners states into the upper MS Valley during the day, and will tilt eastward across the upper Great Lakes overnight as a strong upper trough affects the northern Rockies and pushes into the western Dakotas late. At the surface, high pressure will be most prominent from James Bay into New England, with a ridge extending southwestward across the central Plains and toward the Four Corners region. Low pressure will deepen over southern SK during the day and into central MB overnight, with a rather dry cold front pushing east across MT. To the south, mid to occasional upper 60s F dewpoints will stretch from southern AL across GA and into the Mid Atlantic, with mid 70s F over the FL Peninsula. Little focus will exist for storms across this relatively moist zone, but an uncapped air mass and heating may yield widely scattered afternoon thunderstorms over FL and perhaps ahead of the upper low from OH into WV. Elsewhere, isolated high-based thunderstorms may occur near the Wasatch Range, where lapse rates will be steep through a deep layer and with little overall CAPE or shear. ...FL... The greatest probability of general thunderstorms will be over FL, as the very moist air mass heats. Weak surface convergence may develop over central parts of the Peninsula, with chances maximized through the Cape Canaveral area. Forecast soundings indicate warm temperatures aloft and weak flow. Given up to around 2500 J/kg MLCAPE by late afternoon and ample PWAT over 2.00", gusty outflow may occur. ..Jewell/Halbert.. 09/29/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 PM CDT Sat Sep 28 2024 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Minimal thunderstorm chances exist through the remainder of the period. ...Discussion... Very little lightning is noted across the CONUS as of 01Z. A few convective showers persist over interior parts of the FL Peninsula, where the air mass remains very moist with upper 70s F dewpoints. However, diurnal cooling and lack of appreciable lift should result in a further reduction in coverage this evening. Farther west under the upper ridge, isolated activity will weaken as well over the higher terrain of northern NM, with further thunderstorm chances below the 10% threshold. Overnight, additional thunderstorms will be possible over the eastern Gulf of Mexico and perhaps toward the Tampa FL area, within the deeper theta-e plume. Lack of shear and poor lapse rates aloft suggest weak activity. ..Jewell.. 09/29/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 PM CDT Sat Sep 28 2024 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Minimal thunderstorm chances exist through the remainder of the period. ...Discussion... Very little lightning is noted across the CONUS as of 01Z. A few convective showers persist over interior parts of the FL Peninsula, where the air mass remains very moist with upper 70s F dewpoints. However, diurnal cooling and lack of appreciable lift should result in a further reduction in coverage this evening. Farther west under the upper ridge, isolated activity will weaken as well over the higher terrain of northern NM, with further thunderstorm chances below the 10% threshold. Overnight, additional thunderstorms will be possible over the eastern Gulf of Mexico and perhaps toward the Tampa FL area, within the deeper theta-e plume. Lack of shear and poor lapse rates aloft suggest weak activity. ..Jewell.. 09/29/2024 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Sat Sep 28 2024 Valid 301200Z - 061200Z An upper-level trough will move over the northern Plains and western Great Lakes early next week followed by strong zonal flow aloft along the US-Canadian border. A cold front will sweep southeast through the northern/central Plains and Upper Midwest D3/Monday and to the Gulf and East Coasts D5/Wednesday. Another cold front will slide south through the northern Intermountain West and northern Plains D4/Tuesday - D5/Wednesday. A thermal trough will extend through northwest California to off the southwest Oregon coast into mid-next week, with well above normal temperatures extending from the Desert Southwest through California and into portions of the central Intermountain West. ...D3/Monday: central/northern Plains... A dry cold front will push southeast across the northern and central Plains D3/Monday, with gusty winds overlapping low RH behind it. Widespread elevated conditions are expected, and an area of critical conditions is currently most likely in western/central Nebraska. Forecast uncertainty remains regarding the timing of the front and eastward extent of the dry air that will be monitored in subsequent outlooks. ...D4/Tuesday - D6/Thursday: northern Intermountain West and northern/central High Plains... Another dry cold front will push south through the northern Intermountain West and northern Plains with strong westerly flow aloft. Dry/breezy west-northwest winds are likely across the northern Intermountain West onto portions of the northern/central Plains beginning possibly on D4/Tuesday, with higher chances of dry/breezy conditions D5/Wednesday. The area of concern will shift south on D6/Thursday from the Sierra Front across portions of the Great Basin into Wyoming. While elevated conditions are likely across portions of these areas during this period, there is too much forecast uncertainty to delineate areas at this time. ...D3/Monday - D5/Wednesday: northwest California and southwest Oregon... Offshore winds are likely to develop at times, most likely overnight on mid/upper slopes, in portions of southwest Oregon and northwest California. The overlap of critical winds/RH will likely be relatively sporadic and isolated but will be monitored going forward. ...D5/Wednesday - D6/Thursday: southern/central Plains... Dry and breezy southerly winds are forecast to develop on portions of the southern/central Plains mid to late next week. Elevated conditions are possible if not likely, but there remains too much forecast uncertainty to issue probabilities of critical conditions at this time. ..Nauslar.. 09/28/2024 ...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 0448 PM CDT Sat Sep 28 2024 Valid 301200Z - 061200Z An upper-level trough will move over the northern Plains and western Great Lakes early next week followed by strong zonal flow aloft along the US-Canadian border. A cold front will sweep southeast through the northern/central Plains and Upper Midwest D3/Monday and to the Gulf and East Coasts D5/Wednesday. Another cold front will slide south through the northern Intermountain West and northern Plains D4/Tuesday - D5/Wednesday. A thermal trough will extend through northwest California to off the southwest Oregon coast into mid-next week, with well above normal temperatures extending from the Desert Southwest through California and into portions of the central Intermountain West. ...D3/Monday: central/northern Plains... A dry cold front will push southeast across the northern and central Plains D3/Monday, with gusty winds overlapping low RH behind it. Widespread elevated conditions are expected, and an area of critical conditions is currently most likely in western/central Nebraska. Forecast uncertainty remains regarding the timing of the front and eastward extent of the dry air that will be monitored in subsequent outlooks. ...D4/Tuesday - D6/Thursday: northern Intermountain West and northern/central High Plains... Another dry cold front will push south through the northern Intermountain West and northern Plains with strong westerly flow aloft. Dry/breezy west-northwest winds are likely across the northern Intermountain West onto portions of the northern/central Plains beginning possibly on D4/Tuesday, with higher chances of dry/breezy conditions D5/Wednesday. The area of concern will shift south on D6/Thursday from the Sierra Front across portions of the Great Basin into Wyoming. While elevated conditions are likely across portions of these areas during this period, there is too much forecast uncertainty to delineate areas at this time. ...D3/Monday - D5/Wednesday: northwest California and southwest Oregon... Offshore winds are likely to develop at times, most likely overnight on mid/upper slopes, in portions of southwest Oregon and northwest California. The overlap of critical winds/RH will likely be relatively sporadic and isolated but will be monitored going forward. ...D5/Wednesday - D6/Thursday: southern/central Plains... Dry and breezy southerly winds are forecast to develop on portions of the southern/central Plains mid to late next week. Elevated conditions are possible if not likely, but there remains too much forecast uncertainty to issue probabilities of critical conditions at this time. ..Nauslar.. 09/28/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sat Sep 28 21:54:02 UTC 2024.

No Mesoscale Discussions are in effect as of Sat Sep 28 21:54:02 UTC 2024.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0217 PM CDT Sat Sep 28 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR THE NEBRASKA PANHANDLE INTO SOUTH-CENTRAL NORTH DAKOTA... The Elevated areas in the central/northern Plains and eastern Washington were expanded to reflect the latest high-resolution forecast guidance. Locally elevated conditions may develop farther east on the northern Plains into northwest Minnesota and in portions of eastern Oregon into southwest Idaho as well. Breezy offshore winds are likely to develop overnight in far southwest Oregon and northwest California, most likely affecting mid/upper slopes, and may result in locally elevated conditions. Otherwise, the forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 09/28/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Sat Sep 28 2024/ ...Synopsis... A deepening mid to upper-level trough and accompanying jet streak are expected to traverse the western Canadian provinces Sunday. At the surface, a low will deepen across the northern Rockies and tightening pressure gradients will develop from the northern Plains, into the Intermountain West, and Cascades. The result will be increasing surface winds within these areas. A dry return-flow regime over the northern Plains will unfold, where high confidence in the latest guidance suggests speeds around 15-25 mph by the afternoon. Persistent low moisture content of fine to medium fuels across this region, ERCs exceeding 95th percentiles, and RH in the low teens warrants a narrow Critical area from the NE Panhandle through west-central SD. Further west of this region, southwest to westerly winds of slightly lower speeds will impact central WY, southern MT, and portions of ID. Two other Elevated areas have also been included for the Great Basin and Columbia River Basin of WA. Fuels across the former region continue to become more receptive to fire spread due to persistent warm and dry conditions, but only transient elevated to critical south-southwest winds are anticipated. Dry, westerly downslope surface flow near 15 mph coinciding with RH in the upper teens preceding the trough will impact eastern WA. If later guidance suggest a deeper and/or slower trough progression, this Elevated area may need to be expanded. ...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 0211 PM CDT Sat Sep 28 2024 Valid 282000Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...20Z Update... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 09/28/2024 .PREV DISCUSSION... /ISSUED 1058 AM CDT Sat Sep 28 2024/ A relatively quiet convective day is forecast across the CONUS today. Afternoon thunderstorms may affect the higher terrain of northern NM and southern CO, as well as along a weak occluded front from lower MI into NY. Weak instability and limited shear will preclude severe storms. Scattered thunderstorms will also be possible this afternoon and tonight across the FL peninsula and along the GA/SC/NC coast. Weak winds aloft will limit the organization of these storms, with no severe activity expected. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CDT Sat Sep 28 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Discussion... A weakening, positive-tilt mid/upper trough will drift east over the central/southern Appalachians. Similar to prior days, a confined belt of stronger mid-level southwesterlies will remain present from eastern Georgia into the eastern Carolinas. The surface pattern in the East will remain quite diffuse. Isolated thunderstorms are possible, mainly during Monday afternoon, centered on parts of central/eastern NC/VA. Weak mid/upper-level lapse rates and nebulous forcing for ascent will remain limiting factors to storm intensity. Daytime heating of a moist low-level airmass and lift from sea breeze boundaries will promote isolated to scattered thunderstorms in a weakly sheared environment across the Florida Peninsula. In the West, potential for very isolated afternoon thunderstorms should shift southeast from the eastern Great Basin on Sunday to the southern Rockies and Mogollon Rim on Monday. Scant buoyancy and nebulous large-scale ascent suggest thunderstorm probabilities are only around 10 percent. ..Grams.. 09/28/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CDT Sat Sep 28 2024 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Discussion... A weakening, positive-tilt mid/upper trough will drift east over the central/southern Appalachians. Similar to prior days, a confined belt of stronger mid-level southwesterlies will remain present from eastern Georgia into the eastern Carolinas. The surface pattern in the East will remain quite diffuse. Isolated thunderstorms are possible, mainly during Monday afternoon, centered on parts of central/eastern NC/VA. Weak mid/upper-level lapse rates and nebulous forcing for ascent will remain limiting factors to storm intensity. Daytime heating of a moist low-level airmass and lift from sea breeze boundaries will promote isolated to scattered thunderstorms in a weakly sheared environment across the Florida Peninsula. In the West, potential for very isolated afternoon thunderstorms should shift southeast from the eastern Great Basin on Sunday to the southern Rockies and Mogollon Rim on Monday. Scant buoyancy and nebulous large-scale ascent suggest thunderstorm probabilities are only around 10 percent. ..Grams.. 09/28/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1143 AM CDT Sat Sep 28 2024 Valid 291200Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely on Sunday. ...Eastern Great Basin... Very isolated thunderstorm development is possible on Sunday afternoon amid scattered high-based, low-topped convection. A low-amplitude mid-level low currently off the southern CA coast should progress into southern CA before stalling Sunday night. Weak forcing for ascent combined with recycled 700-mb moisture within the Four Corners States may be adequate for a 10 percent chance of thunderstorms. The more moist spectrum of guidance suggests buoyancy will remain scant. Even with the low thunder probability, very large surface temperature-dew point spreads will support dry microburst potential and locally strong gusts. ...Upper OH Valley to the Lower Mid-Atlantic... Ahead of the positive-tilt mid/upper trough drifting east across KY/TN, isolated lower-topped thunderstorms will be possible, mainly during Sunday afternoon. Mid-level temperatures will be relatively warm east-southeast of the trough and cooler to the northeast. Boundary-layer warming will be more limited with northern extent amid abundant cloud coverage and early-day showers. As such, instability will be weak regionwide. A confined belt of stronger mid-level southwesterlies should be over GA into the Carolinas. Within this sub-region, the warm temperatures and poor lapse rates aloft will probably hold thunder probs around 10 percent or less, yielding negligible severe concern. ..Grams.. 09/28/2024 Read more