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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1106 AM CDT Tue Jul 09 2024 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... No further forecast updates are necessary, as current thinking remains unchanged. See previous discussion for further detail. ..Halbert/Weinman.. 07/09/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Tue Jul 09 2024/ ...Synopsis... Strong upper-level ridging aloft will generally keep winds generally light across the western US today where the most critical fuels are presently located. Very warm and dry conditions are forecast, with afternoon relative humidity reductions to 5-15 percent across much of the region. Sundowner winds will lead to localized Elevated to Critical fire weather concerns across Santa Barbra County in southern California, but these conditions remain too localized for highlights. Isolated dry thunderstorms are possible across the Central Rockies Tuesday afternoon. Overall, this threat remains too localized for highlights. ...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 1106 AM CDT Tue Jul 09 2024 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... No further forecast updates are necessary, as current thinking remains unchanged. See previous discussion for further detail. ..Halbert/Weinman.. 07/09/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Tue Jul 09 2024/ ...Synopsis... Strong upper-level ridging aloft will generally keep winds generally light across the western US today where the most critical fuels are presently located. Very warm and dry conditions are forecast, with afternoon relative humidity reductions to 5-15 percent across much of the region. Sundowner winds will lead to localized Elevated to Critical fire weather concerns across Santa Barbra County in southern California, but these conditions remain too localized for highlights. Isolated dry thunderstorms are possible across the Central Rockies Tuesday afternoon. Overall, this threat remains too localized for highlights. ...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 1106 AM CDT Tue Jul 09 2024 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... No further forecast updates are necessary, as current thinking remains unchanged. See previous discussion for further detail. ..Halbert/Weinman.. 07/09/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Tue Jul 09 2024/ ...Synopsis... Strong upper-level ridging aloft will generally keep winds generally light across the western US today where the most critical fuels are presently located. Very warm and dry conditions are forecast, with afternoon relative humidity reductions to 5-15 percent across much of the region. Sundowner winds will lead to localized Elevated to Critical fire weather concerns across Santa Barbra County in southern California, but these conditions remain too localized for highlights. Isolated dry thunderstorms are possible across the Central Rockies Tuesday afternoon. Overall, this threat remains too localized for highlights. ...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 1106 AM CDT Tue Jul 09 2024 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... No further forecast updates are necessary, as current thinking remains unchanged. See previous discussion for further detail. ..Halbert/Weinman.. 07/09/2024 .PREV DISCUSSION... /ISSUED 0158 AM CDT Tue Jul 09 2024/ ...Synopsis... Strong upper-level ridging aloft will generally keep winds generally light across the western US today where the most critical fuels are presently located. Very warm and dry conditions are forecast, with afternoon relative humidity reductions to 5-15 percent across much of the region. Sundowner winds will lead to localized Elevated to Critical fire weather concerns across Santa Barbra County in southern California, but these conditions remain too localized for highlights. Isolated dry thunderstorms are possible across the Central Rockies Tuesday afternoon. Overall, this threat remains too localized for highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

The NHC has issued its final advisory on this system. Public Advisories from the Weather Prediction Center will provide updates as long as the system remains a flood threat. Issued at 1000 AM CDT Tue Jul 09 2024

5-Day Uncertainty Track last updated LATEST_W5_TIMESTAMP

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Tue Jul 09 2024 Valid 091300Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN KENTUCKY AND SOUTHERN INDIANA... ...SUMMARY... Several tornadoes are possible today over the lower Ohio Valley in association with the remnants of Beryl. ...Lower Ohio Valley/Mid Mississippi Valley... Water-vapor imagery this morning shows a progressive mid-level shortwave trough moving east across the lower MO Valley/Ozarks. This mid-level trough is forecast to reach Lake Michigan/Indiana by late tonight. The remnants of Beryl will move across the mid Mississippi and lower Ohio Valleys today. Ahead of the associated surface low, morning surface analysis indicates a reservoir of lower 70s deg F dewpoints from the IN/OH/KY tri-state south/southwest into the Mid South ahead of the low. Surface streamlines show a warm frontal zone extending east-northeast from the low. The warm front will advance northward to near the OH River by mid afternoon and serve as a focus for severe thunderstorm potential. Despite considerable cloud cover this morning, significant cloud breaks south of the warm front and pockets of heating will destabilize the airmass from the mid MS Valley to the OH Valley. Moderate buoyancy is forecast to develop in the vicinity of the warm front and to its south over parts of KY/TN. Models imply, and this notion is supported by morning observational trends, that a couple of convective bands will preferentially favor storm development today. Widely scattered to scattered thunderstorms are forecast to develop within a moderately unstable airmass (1000-1500 J/kg MLCAPE). Forecast hodographs will become enlarged --especially in the warm frontal zone where backed low-level flow will reside-- as a 30-40 southerly 850-mb LLJ overspreads the OH Valley during the afternoon/evening. One or more bands of quasi-discrete supercells are forecast with tornado potential greatest in a southwest to northeast corridor paralleling the OH River this afternoon into the evening. ...New England... A low-amplitude trough at mid-levels will move eastward across Quebec and New England during the period. Heating of a seasonably moist airmass by afternoon will aid in the development of scattered thunderstorms. A few organized multicells and perhaps a transient supercell or two, will pose an isolated risk for 50-65 mph gusts and large hail. ..Smith/Bentley.. 07/09/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Tue Jul 09 2024 Valid 091300Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN KENTUCKY AND SOUTHERN INDIANA... ...SUMMARY... Several tornadoes are possible today over the lower Ohio Valley in association with the remnants of Beryl. ...Lower Ohio Valley/Mid Mississippi Valley... Water-vapor imagery this morning shows a progressive mid-level shortwave trough moving east across the lower MO Valley/Ozarks. This mid-level trough is forecast to reach Lake Michigan/Indiana by late tonight. The remnants of Beryl will move across the mid Mississippi and lower Ohio Valleys today. Ahead of the associated surface low, morning surface analysis indicates a reservoir of lower 70s deg F dewpoints from the IN/OH/KY tri-state south/southwest into the Mid South ahead of the low. Surface streamlines show a warm frontal zone extending east-northeast from the low. The warm front will advance northward to near the OH River by mid afternoon and serve as a focus for severe thunderstorm potential. Despite considerable cloud cover this morning, significant cloud breaks south of the warm front and pockets of heating will destabilize the airmass from the mid MS Valley to the OH Valley. Moderate buoyancy is forecast to develop in the vicinity of the warm front and to its south over parts of KY/TN. Models imply, and this notion is supported by morning observational trends, that a couple of convective bands will preferentially favor storm development today. Widely scattered to scattered thunderstorms are forecast to develop within a moderately unstable airmass (1000-1500 J/kg MLCAPE). Forecast hodographs will become enlarged --especially in the warm frontal zone where backed low-level flow will reside-- as a 30-40 southerly 850-mb LLJ overspreads the OH Valley during the afternoon/evening. One or more bands of quasi-discrete supercells are forecast with tornado potential greatest in a southwest to northeast corridor paralleling the OH River this afternoon into the evening. ...New England... A low-amplitude trough at mid-levels will move eastward across Quebec and New England during the period. Heating of a seasonably moist airmass by afternoon will aid in the development of scattered thunderstorms. A few organized multicells and perhaps a transient supercell or two, will pose an isolated risk for 50-65 mph gusts and large hail. ..Smith/Bentley.. 07/09/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Tue Jul 09 2024 Valid 091300Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN KENTUCKY AND SOUTHERN INDIANA... ...SUMMARY... Several tornadoes are possible today over the lower Ohio Valley in association with the remnants of Beryl. ...Lower Ohio Valley/Mid Mississippi Valley... Water-vapor imagery this morning shows a progressive mid-level shortwave trough moving east across the lower MO Valley/Ozarks. This mid-level trough is forecast to reach Lake Michigan/Indiana by late tonight. The remnants of Beryl will move across the mid Mississippi and lower Ohio Valleys today. Ahead of the associated surface low, morning surface analysis indicates a reservoir of lower 70s deg F dewpoints from the IN/OH/KY tri-state south/southwest into the Mid South ahead of the low. Surface streamlines show a warm frontal zone extending east-northeast from the low. The warm front will advance northward to near the OH River by mid afternoon and serve as a focus for severe thunderstorm potential. Despite considerable cloud cover this morning, significant cloud breaks south of the warm front and pockets of heating will destabilize the airmass from the mid MS Valley to the OH Valley. Moderate buoyancy is forecast to develop in the vicinity of the warm front and to its south over parts of KY/TN. Models imply, and this notion is supported by morning observational trends, that a couple of convective bands will preferentially favor storm development today. Widely scattered to scattered thunderstorms are forecast to develop within a moderately unstable airmass (1000-1500 J/kg MLCAPE). Forecast hodographs will become enlarged --especially in the warm frontal zone where backed low-level flow will reside-- as a 30-40 southerly 850-mb LLJ overspreads the OH Valley during the afternoon/evening. One or more bands of quasi-discrete supercells are forecast with tornado potential greatest in a southwest to northeast corridor paralleling the OH River this afternoon into the evening. ...New England... A low-amplitude trough at mid-levels will move eastward across Quebec and New England during the period. Heating of a seasonably moist airmass by afternoon will aid in the development of scattered thunderstorms. A few organized multicells and perhaps a transient supercell or two, will pose an isolated risk for 50-65 mph gusts and large hail. ..Smith/Bentley.. 07/09/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Tue Jul 09 2024 Valid 091300Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN KENTUCKY AND SOUTHERN INDIANA... ...SUMMARY... Several tornadoes are possible today over the lower Ohio Valley in association with the remnants of Beryl. ...Lower Ohio Valley/Mid Mississippi Valley... Water-vapor imagery this morning shows a progressive mid-level shortwave trough moving east across the lower MO Valley/Ozarks. This mid-level trough is forecast to reach Lake Michigan/Indiana by late tonight. The remnants of Beryl will move across the mid Mississippi and lower Ohio Valleys today. Ahead of the associated surface low, morning surface analysis indicates a reservoir of lower 70s deg F dewpoints from the IN/OH/KY tri-state south/southwest into the Mid South ahead of the low. Surface streamlines show a warm frontal zone extending east-northeast from the low. The warm front will advance northward to near the OH River by mid afternoon and serve as a focus for severe thunderstorm potential. Despite considerable cloud cover this morning, significant cloud breaks south of the warm front and pockets of heating will destabilize the airmass from the mid MS Valley to the OH Valley. Moderate buoyancy is forecast to develop in the vicinity of the warm front and to its south over parts of KY/TN. Models imply, and this notion is supported by morning observational trends, that a couple of convective bands will preferentially favor storm development today. Widely scattered to scattered thunderstorms are forecast to develop within a moderately unstable airmass (1000-1500 J/kg MLCAPE). Forecast hodographs will become enlarged --especially in the warm frontal zone where backed low-level flow will reside-- as a 30-40 southerly 850-mb LLJ overspreads the OH Valley during the afternoon/evening. One or more bands of quasi-discrete supercells are forecast with tornado potential greatest in a southwest to northeast corridor paralleling the OH River this afternoon into the evening. ...New England... A low-amplitude trough at mid-levels will move eastward across Quebec and New England during the period. Heating of a seasonably moist airmass by afternoon will aid in the development of scattered thunderstorms. A few organized multicells and perhaps a transient supercell or two, will pose an isolated risk for 50-65 mph gusts and large hail. ..Smith/Bentley.. 07/09/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Tue Jul 09 2024 Valid 091300Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN KENTUCKY AND SOUTHERN INDIANA... ...SUMMARY... Several tornadoes are possible today over the lower Ohio Valley in association with the remnants of Beryl. ...Lower Ohio Valley/Mid Mississippi Valley... Water-vapor imagery this morning shows a progressive mid-level shortwave trough moving east across the lower MO Valley/Ozarks. This mid-level trough is forecast to reach Lake Michigan/Indiana by late tonight. The remnants of Beryl will move across the mid Mississippi and lower Ohio Valleys today. Ahead of the associated surface low, morning surface analysis indicates a reservoir of lower 70s deg F dewpoints from the IN/OH/KY tri-state south/southwest into the Mid South ahead of the low. Surface streamlines show a warm frontal zone extending east-northeast from the low. The warm front will advance northward to near the OH River by mid afternoon and serve as a focus for severe thunderstorm potential. Despite considerable cloud cover this morning, significant cloud breaks south of the warm front and pockets of heating will destabilize the airmass from the mid MS Valley to the OH Valley. Moderate buoyancy is forecast to develop in the vicinity of the warm front and to its south over parts of KY/TN. Models imply, and this notion is supported by morning observational trends, that a couple of convective bands will preferentially favor storm development today. Widely scattered to scattered thunderstorms are forecast to develop within a moderately unstable airmass (1000-1500 J/kg MLCAPE). Forecast hodographs will become enlarged --especially in the warm frontal zone where backed low-level flow will reside-- as a 30-40 southerly 850-mb LLJ overspreads the OH Valley during the afternoon/evening. One or more bands of quasi-discrete supercells are forecast with tornado potential greatest in a southwest to northeast corridor paralleling the OH River this afternoon into the evening. ...New England... A low-amplitude trough at mid-levels will move eastward across Quebec and New England during the period. Heating of a seasonably moist airmass by afternoon will aid in the development of scattered thunderstorms. A few organized multicells and perhaps a transient supercell or two, will pose an isolated risk for 50-65 mph gusts and large hail. ..Smith/Bentley.. 07/09/2024 Read more

000
ABPZ20 KNHC 091127
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Tue Jul 9 2024

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

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Hagen/Brown

000
ABNT20 KNHC 091127
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Tue Jul 9 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The Weather Prediction Center is issuing advisories on Tropical
Depression Beryl, located inland over Arkansas.

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Hagen/Brown

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Jul 09 2024 Valid 121200Z - 171200Z ...DISCUSSION... Deterministic and ensemble guidance offers a strong consensus on a general pattern shift involving deamplification of cyclonic flow over the Great Lakes, Ohio Valley and northeast on day 4 (12th-13th) through day 6 (14th-15th), but with a weaker version of the longwave trough lingering in that region through the remainder of the outlook period. Meanwhile, the Great Basin anticyclone is progged to expand and shift eastward toward the central Rockies day 4 through day 6, then deamplify over the central Plains. This process should reinforce an EML over the western plateaus and expand it eastward across the central Plains. As that occurs, west-northwesterly flow aloft should set up between the northern Plains and Great Lakes, mostly (but not entirely) north of a mean low-level frontal zone occupying a corridor from the north-central High Plains to the lower Missouri/Ohio Valleys. Strong lapse rates related to the EML, atop an enlarging area of upper 60s to mid 70s F surface dewpoints (from both advection and evapotranspiration), will yield a high-CAPE parameter space near the front. Provided it is not too far removed from that large buoyancy, the northeastern rim of the stronger EML capping, aligned parallel to the frontal instability gradient, may provide a favorable corridor for development/propagation of organized, severe-wind-producing MCS activity on at least one or two of those days, from the weekend into early next week. Activity may be supported by subtle shortwave troughs embedded in the largely front-parallel flow. Confidence in shortwave details, and in which day the cap is more likely to weaken enough to support suitable initiation and upscale growth, currently is too low to assign probabilities to a particular day in the series of somewhat similar ones, pattern-wise. Read more

The NHC has issued its final advisory on this system. Public Advisories from the Weather Prediction Center will provide updates as long as the system remains a flood threat. Issued at 400 AM CDT Tue Jul 09 2024