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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sat Jul 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHEAST AND THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... Strong to isolated severe thunderstorms are possible over parts of the Southeast and central to southern High Plains, mainly from mid-afternoon to evening. ...20Z Update... Minimal changes were made to the outlook with this update, as the previous forecast remains on track. Scattered multicell thunderstorms (with occasional/transient supercell structures) will continue spreading east-northeastward across the Southeast this afternoon. Given a hot/moist boundary layer and around 2 inch PW extending from northeast FL northward into southeast VA, sporadic damaging winds (generally 50-60 mph) will be possible. Farther west, isolated to widely scattered thunderstorms will gradually increase in coverage across the central and southern High Plains this afternoon, with isolated large hail and severe gusts possible with the strongest storms. Reference forthcoming MCD 1687 for additional details. Over portions southern AZ, temperatures have climbed into the 100-105 F range amid upper 50s/lower 60s dewpoints. While weak midlevel flow will limit storm longevity/organization, occasional strong to locally severe gusts cannot be ruled out this afternoon. ..Weinman/Smith.. 07/20/2024 .PREV DISCUSSION... /ISSUED 1113 AM CDT Sat Jul 20 2024/ ...Southeast... Water-vapor imagery late this morning shows a mid-level shortwave trough moving slowly east across KY/TN/AL towards the southern Appalachians. A mid-level anticyclone located over the Gulf Stream to the east of the Southeast U.S. will move little during the period. Late morning surface analysis indicates a very moist airmass resides over the coastal plains of GA/Carolinas with mid 70s deg F dewpoints. Ample heating via mostly sunny skies (per visible satellite data) east of a line from Macon, GA to Columbia, SC, and to the Research Triangle, will result in a moderately unstable boundary layer by early to mid afternoon. Forecast soundings show PW around 2 to 2.25 inches and moderate effective shear (20-30 kt). Scattered thunderstorms will likely develop in several clusters as convective temperatures are breached by early afternoon. Given the buoyant/high PW environment, water-loaded downdrafts will accompany the stronger thunderstorm cores. Isolated wet microbursts capable of 45-60 mph gusts will potentially result in isolated to widely scattered wind damage this afternoon and early evening. ...Central and southern High Plains... Isolated to scattered thunderstorms are expected to develop this afternoon along the Front Range/Sangre de Cristo corridor from southeastern WY to NM, as well as over the Raton Mesa, near the lee trough, and along leftover outflow/differential-heating boundaries from prior overnight/morning convection. Isolated severe gusts and hail are possible with the stronger storms before this activity diminishes by mid to late evening. Read more

MD 1686 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEASTERN GEORGIA INTO SOUTHERN SOUTH CAROLINA
Mesoscale Discussion 1686 NWS Storm Prediction Center Norman OK 0105 PM CDT Sat Jul 20 2024 Areas affected...Southeastern Georgia into southern South Carolina Concerning...Severe potential...Watch unlikely Valid 201805Z - 202000Z Probability of Watch Issuance...20 percent SUMMARY...Storms will intensify along a differential heating boundary and along the sea breeze. Isolated damaging winds are the primary hazard. Should clustering occur a locally greater wind damage threat would be possible. A small severe thunderstorm watch would be considered if that occurs. DISCUSSION...Though cloud cover has generally eroded across northern Georgia/Upstate South Carolina, temperatures have remained cooler in those locations thus far. This has set up a differential heating boundary from central Georgia into southern South Carolina. Cumulus development is ongoing along this boundary as well as the sea breeze. Thunderstorms have already initiated in central/east-central Georgia and have been deepening over the last hour per MRMS CAPPI data. The observed morning sounding from Charleston showed modestly steeper mid-level lapse rates than other regional soundings (6-6.5 C/km). Portions of southeast Georgia into southern South Carolina should have some of the better overlap of buoyancy and effective shear given the enhanced mid-level winds over the region. As storms continue to deepen/intensify with continued heating, the expectation is for marginally organized multicells to be capable of sporadic wind damage. Should clustering occur, a locally greater wind damage threat would be possible. ..Wendt/Smith.. 07/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...CAE...JAX...FFC...TAE... LAT...LON 32128363 32698339 33508112 33058019 32418060 31778120 31248161 30638209 30588247 31688358 32128363 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...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 1244 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHEASTERN OREGON...AND FAR NORTHWESTERN NEVADA... ...Update... Overall, the fire weather forecast has changed very little for Sunday. Scattered dry thunderstorms are expected to develop during the afternoon across portions of the northwestern Great Basin and OR High Desert, with isolated coverage extending over the northern Sierra Nevada and Cascades. In addition to dry thunderstorm chances, sustained northerly wind speeds around 15 mph and low RH near northwestern CO, where seasonal ERC percentiles are beginning to exceed 80, may result in some localized, brief elevated fire spread conditions. However, the duration of these conditions do not currently warrant an Elevated area. Please see the previous discussion below for additional details pertaining to dry thunderstorms. ..Barnes.. 07/20/2024 .PREV DISCUSSION... /ISSUED 0223 AM CDT Sat Jul 20 2024/ ...Synopsis... The strong upper ridge will remain in place over the Western US Day2 Sunday as a weak upper trough passes along the western periphery. Mid-level moisture will advect inland ahead of the trough, supporting the potential for scattered thunderstorms over much of the Northwest. Low rainfall efficiency is expected with these dry thunderstorms over portions of the Cascades and northern Great Basin. Significant lightning activity is possible within dry fuels D2/Sunday. ...Northwest and northern Great Basin... Isolated thunderstorms are expected to be ongoing at the start of the period as the upper trough continues northward along the western periphery of the upper ridge. Coverage appears greatest west of the Cascades and toward the Coastal ranges of WA and OR. While these initial storms should slowly diminish in coverage through the morning, at least isolated lightning will remain possible over dry fuels across parts of southern WA and northern OR. A second round of storms is expected to develop by early to mid afternoon as weak ascent from the departing upper trough and orographic lift overlap with diurnal heating. Very warm surface temperatures and continued mid-level moistening will support weak destabilization atop deep and well-mixed sub-cloud layer depths of 2-3 km. 30-40 kt of mid-level southerly flow will also favor moderate storm motions, suggesting very little potential for wetting rainfall. Convection should gradually expand along the higher terrain of the Cascades and northern Great Basin from northern NV/CA into OR and WA through the day. Scattered fast-moving thunderstorms and receptive fuels (ERCs exceeding the 95th percentile) will favor efficient lightning ignitions and gusty/erratic surface winds beneath passing storms. Given the volatile state of area fuels and significant ongoing fire activity, the potential for scattered lightning coverage warrants the introduction of critical Dry T probabilities. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

000
ABPZ20 KNHC 201741
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Jul 20 2024

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

Central and Western East Pacific:
A tropical wave located well to the south of the southwestern coast
of Mexico continues to produce a large area of disorganized showers
and thunderstorms. Environmental conditions appear conducive for
some gradual development of this system over the next several days
while it moves westward to west-northwestward at 10 to 15 mph across
the central and western portions of the basin.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 percent.

$$
Forecaster Reinhart

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe-thunderstorm potential is expected to be low on Sunday. ...Discussion... Little change is expected in the upper flow field configuration over the U.S. Sunday, with ridging to remain over the West, and weak troughing/cyclonic flow over most of the central and eastern portions of the country. At the surface, a weak baroclinic zone is forecast to extend from the southern New England vicinity west-southwestward across the Tennessee Valley area and into the southern Plains. Showers and thunderstorms -- with coverage peaking through the afternoon and evening hours -- are expected across a large portion of the country. However, with modest flow aloft prevailing, potential for well-organized storms remains low. One area where risk for a strong wind gust or two may be slightly greater, will be across roughly the southern half of Arizona. Storms developing over the Mogollon Rim during the afternoon should move southward off the higher terrain. With the typical dry/deep mixed layer expected over the lower deserts, evaporative effects may support some downdraft enhancement with the strongest storms. However, at this time it appears that mid-level northerlies are a bit weak to support a more organized, southward-propagating convective event. ..Goss.. 07/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe-thunderstorm potential is expected to be low on Sunday. ...Discussion... Little change is expected in the upper flow field configuration over the U.S. Sunday, with ridging to remain over the West, and weak troughing/cyclonic flow over most of the central and eastern portions of the country. At the surface, a weak baroclinic zone is forecast to extend from the southern New England vicinity west-southwestward across the Tennessee Valley area and into the southern Plains. Showers and thunderstorms -- with coverage peaking through the afternoon and evening hours -- are expected across a large portion of the country. However, with modest flow aloft prevailing, potential for well-organized storms remains low. One area where risk for a strong wind gust or two may be slightly greater, will be across roughly the southern half of Arizona. Storms developing over the Mogollon Rim during the afternoon should move southward off the higher terrain. With the typical dry/deep mixed layer expected over the lower deserts, evaporative effects may support some downdraft enhancement with the strongest storms. However, at this time it appears that mid-level northerlies are a bit weak to support a more organized, southward-propagating convective event. ..Goss.. 07/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Jul 20 2024 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe-thunderstorm potential is expected to be low on Sunday. ...Discussion... Little change is expected in the upper flow field configuration over the U.S. Sunday, with ridging to remain over the West, and weak troughing/cyclonic flow over most of the central and eastern portions of the country. At the surface, a weak baroclinic zone is forecast to extend from the southern New England vicinity west-southwestward across the Tennessee Valley area and into the southern Plains. Showers and thunderstorms -- with coverage peaking through the afternoon and evening hours -- are expected across a large portion of the country. However, with modest flow aloft prevailing, potential for well-organized storms remains low. One area where risk for a strong wind gust or two may be slightly greater, will be across roughly the southern half of Arizona. Storms developing over the Mogollon Rim during the afternoon should move southward off the higher terrain. With the typical dry/deep mixed layer expected over the lower deserts, evaporative effects may support some downdraft enhancement with the strongest storms. However, at this time it appears that mid-level northerlies are a bit weak to support a more organized, southward-propagating convective event. ..Goss.. 07/20/2024 Read more