Aggregator

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected across the U.S. Sunday. ...Discussion... A shortwave trough will move through the Great Lakes and Northeast U.S. during the day, while an upstream low-amplitude ridge builds across the northern Plains and upper MS Valley regions. A high-amplitude upper trough will move into the Pacific Northwest. Farther south an upper low will drift slowly westward through the western Gulf, while a weak shortwave trough drifts slowly northward through the southwestern States. Tropical Storm Humberto is forecast by the NHC to remain well off the FL coast. Thunderstorms will likely be ongoing across a portion of the Great Lakes along and ahead of a cold front and in association with the aforementioned progressive shortwave trough. While this activity will reside within a belt of moderate deep-layer winds, updrafts will likely be elevated and will encounter an increasingly marginal thermodynamic environment as they continue east. Surface-based thunderstorm development along the southwestern extension of the front across the middle MS Valley and central Plains appears unlikely due to weak frontal convergence and potential mid-level subsidence with building upper ridge. Elsewhere, general thunderstorms are expected from the Gulf Coast through the coastal Carolinas as well as a portion of the Southwestern States. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Dial.. 09/14/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected across the U.S. Sunday. ...Discussion... A shortwave trough will move through the Great Lakes and Northeast U.S. during the day, while an upstream low-amplitude ridge builds across the northern Plains and upper MS Valley regions. A high-amplitude upper trough will move into the Pacific Northwest. Farther south an upper low will drift slowly westward through the western Gulf, while a weak shortwave trough drifts slowly northward through the southwestern States. Tropical Storm Humberto is forecast by the NHC to remain well off the FL coast. Thunderstorms will likely be ongoing across a portion of the Great Lakes along and ahead of a cold front and in association with the aforementioned progressive shortwave trough. While this activity will reside within a belt of moderate deep-layer winds, updrafts will likely be elevated and will encounter an increasingly marginal thermodynamic environment as they continue east. Surface-based thunderstorm development along the southwestern extension of the front across the middle MS Valley and central Plains appears unlikely due to weak frontal convergence and potential mid-level subsidence with building upper ridge. Elsewhere, general thunderstorms are expected from the Gulf Coast through the coastal Carolinas as well as a portion of the Southwestern States. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Dial.. 09/14/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected across the U.S. Sunday. ...Discussion... A shortwave trough will move through the Great Lakes and Northeast U.S. during the day, while an upstream low-amplitude ridge builds across the northern Plains and upper MS Valley regions. A high-amplitude upper trough will move into the Pacific Northwest. Farther south an upper low will drift slowly westward through the western Gulf, while a weak shortwave trough drifts slowly northward through the southwestern States. Tropical Storm Humberto is forecast by the NHC to remain well off the FL coast. Thunderstorms will likely be ongoing across a portion of the Great Lakes along and ahead of a cold front and in association with the aforementioned progressive shortwave trough. While this activity will reside within a belt of moderate deep-layer winds, updrafts will likely be elevated and will encounter an increasingly marginal thermodynamic environment as they continue east. Surface-based thunderstorm development along the southwestern extension of the front across the middle MS Valley and central Plains appears unlikely due to weak frontal convergence and potential mid-level subsidence with building upper ridge. Elsewhere, general thunderstorms are expected from the Gulf Coast through the coastal Carolinas as well as a portion of the Southwestern States. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Dial.. 09/14/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected across the U.S. Sunday. ...Discussion... A shortwave trough will move through the Great Lakes and Northeast U.S. during the day, while an upstream low-amplitude ridge builds across the northern Plains and upper MS Valley regions. A high-amplitude upper trough will move into the Pacific Northwest. Farther south an upper low will drift slowly westward through the western Gulf, while a weak shortwave trough drifts slowly northward through the southwestern States. Tropical Storm Humberto is forecast by the NHC to remain well off the FL coast. Thunderstorms will likely be ongoing across a portion of the Great Lakes along and ahead of a cold front and in association with the aforementioned progressive shortwave trough. While this activity will reside within a belt of moderate deep-layer winds, updrafts will likely be elevated and will encounter an increasingly marginal thermodynamic environment as they continue east. Surface-based thunderstorm development along the southwestern extension of the front across the middle MS Valley and central Plains appears unlikely due to weak frontal convergence and potential mid-level subsidence with building upper ridge. Elsewhere, general thunderstorms are expected from the Gulf Coast through the coastal Carolinas as well as a portion of the Southwestern States. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Dial.. 09/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Sep 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTH-CENTRAL AZ... ...SUMMARY... Isolated to scattered severe wind gusts are possible this afternoon and evening across southern and central Arizona. Isolated severe storms with large hail and damaging wind gusts are possible from the Upper Midwest to the central Great Plains through tonight. ...Southern/central AZ... An MCV over western Chihuahua will drift north-northwestward across southeast AZ through tonight. 50s surface dew points are common across southern AZ amid easterly flow north of this MCV. In conjunction with ample heating northwest of the thicker cloud cover near the MCV, a modestly buoyant air mass with MLCAPE approaching 1000 J/kg should develop by peak heating. 15-25 kt east-northeast 700-500 mb winds around the north side of the MCV will be favorable for cells and semi-organized clusters to spread off the Mogollon Rim into the lower deserts with a threat for severe gusts. Whether more organized clustering can evolve is uncertain compared to the significant severe wind event two weeks ago, but there is at least sufficient damaging wind potential to warrant a Slight Risk across parts of the Gila Valley. ...Upper Midwest to the central Great Plains... Elevated thunderstorms are ongoing in western IA on the leading edge of a low-level warm theta-e advection plume. This plume and attendant zone of ascent will spread east-northeast across the Upper MS Valley into tonight in advance of a low-amplitude shortwave trough near the ND/MB border that will move east-southeast into Lake Superior. This elevated convection will pose a threat for isolated large hail, mainly this evening into tonight with a probable decay cycle this afternoon. A risk for locally damaging winds may also develop tonight towards the IA/IL/WI border region if a cluster can become semi-organized. In the wake of the warm advection regime, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining MLCIN through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development should be sparse and may struggle to be sustained during the late afternoon/early evening. If surface-based storms can form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated severe wind and hail. ...Central Appalachians... A narrow corridor of weak to modest buoyancy is expected with scattered storms along a cold front and over the higher terrain through early evening. Isolated strong downburst winds are possible on the periphery of weak to moderate mid-level southwesterlies. ..Grams/Squitieri.. 09/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Sep 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTH-CENTRAL AZ... ...SUMMARY... Isolated to scattered severe wind gusts are possible this afternoon and evening across southern and central Arizona. Isolated severe storms with large hail and damaging wind gusts are possible from the Upper Midwest to the central Great Plains through tonight. ...Southern/central AZ... An MCV over western Chihuahua will drift north-northwestward across southeast AZ through tonight. 50s surface dew points are common across southern AZ amid easterly flow north of this MCV. In conjunction with ample heating northwest of the thicker cloud cover near the MCV, a modestly buoyant air mass with MLCAPE approaching 1000 J/kg should develop by peak heating. 15-25 kt east-northeast 700-500 mb winds around the north side of the MCV will be favorable for cells and semi-organized clusters to spread off the Mogollon Rim into the lower deserts with a threat for severe gusts. Whether more organized clustering can evolve is uncertain compared to the significant severe wind event two weeks ago, but there is at least sufficient damaging wind potential to warrant a Slight Risk across parts of the Gila Valley. ...Upper Midwest to the central Great Plains... Elevated thunderstorms are ongoing in western IA on the leading edge of a low-level warm theta-e advection plume. This plume and attendant zone of ascent will spread east-northeast across the Upper MS Valley into tonight in advance of a low-amplitude shortwave trough near the ND/MB border that will move east-southeast into Lake Superior. This elevated convection will pose a threat for isolated large hail, mainly this evening into tonight with a probable decay cycle this afternoon. A risk for locally damaging winds may also develop tonight towards the IA/IL/WI border region if a cluster can become semi-organized. In the wake of the warm advection regime, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining MLCIN through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development should be sparse and may struggle to be sustained during the late afternoon/early evening. If surface-based storms can form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated severe wind and hail. ...Central Appalachians... A narrow corridor of weak to modest buoyancy is expected with scattered storms along a cold front and over the higher terrain through early evening. Isolated strong downburst winds are possible on the periphery of weak to moderate mid-level southwesterlies. ..Grams/Squitieri.. 09/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Sep 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTH-CENTRAL AZ... ...SUMMARY... Isolated to scattered severe wind gusts are possible this afternoon and evening across southern and central Arizona. Isolated severe storms with large hail and damaging wind gusts are possible from the Upper Midwest to the central Great Plains through tonight. ...Southern/central AZ... An MCV over western Chihuahua will drift north-northwestward across southeast AZ through tonight. 50s surface dew points are common across southern AZ amid easterly flow north of this MCV. In conjunction with ample heating northwest of the thicker cloud cover near the MCV, a modestly buoyant air mass with MLCAPE approaching 1000 J/kg should develop by peak heating. 15-25 kt east-northeast 700-500 mb winds around the north side of the MCV will be favorable for cells and semi-organized clusters to spread off the Mogollon Rim into the lower deserts with a threat for severe gusts. Whether more organized clustering can evolve is uncertain compared to the significant severe wind event two weeks ago, but there is at least sufficient damaging wind potential to warrant a Slight Risk across parts of the Gila Valley. ...Upper Midwest to the central Great Plains... Elevated thunderstorms are ongoing in western IA on the leading edge of a low-level warm theta-e advection plume. This plume and attendant zone of ascent will spread east-northeast across the Upper MS Valley into tonight in advance of a low-amplitude shortwave trough near the ND/MB border that will move east-southeast into Lake Superior. This elevated convection will pose a threat for isolated large hail, mainly this evening into tonight with a probable decay cycle this afternoon. A risk for locally damaging winds may also develop tonight towards the IA/IL/WI border region if a cluster can become semi-organized. In the wake of the warm advection regime, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining MLCIN through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development should be sparse and may struggle to be sustained during the late afternoon/early evening. If surface-based storms can form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated severe wind and hail. ...Central Appalachians... A narrow corridor of weak to modest buoyancy is expected with scattered storms along a cold front and over the higher terrain through early evening. Isolated strong downburst winds are possible on the periphery of weak to moderate mid-level southwesterlies. ..Grams/Squitieri.. 09/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Sep 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTH-CENTRAL AZ... ...SUMMARY... Isolated to scattered severe wind gusts are possible this afternoon and evening across southern and central Arizona. Isolated severe storms with large hail and damaging wind gusts are possible from the Upper Midwest to the central Great Plains through tonight. ...Southern/central AZ... An MCV over western Chihuahua will drift north-northwestward across southeast AZ through tonight. 50s surface dew points are common across southern AZ amid easterly flow north of this MCV. In conjunction with ample heating northwest of the thicker cloud cover near the MCV, a modestly buoyant air mass with MLCAPE approaching 1000 J/kg should develop by peak heating. 15-25 kt east-northeast 700-500 mb winds around the north side of the MCV will be favorable for cells and semi-organized clusters to spread off the Mogollon Rim into the lower deserts with a threat for severe gusts. Whether more organized clustering can evolve is uncertain compared to the significant severe wind event two weeks ago, but there is at least sufficient damaging wind potential to warrant a Slight Risk across parts of the Gila Valley. ...Upper Midwest to the central Great Plains... Elevated thunderstorms are ongoing in western IA on the leading edge of a low-level warm theta-e advection plume. This plume and attendant zone of ascent will spread east-northeast across the Upper MS Valley into tonight in advance of a low-amplitude shortwave trough near the ND/MB border that will move east-southeast into Lake Superior. This elevated convection will pose a threat for isolated large hail, mainly this evening into tonight with a probable decay cycle this afternoon. A risk for locally damaging winds may also develop tonight towards the IA/IL/WI border region if a cluster can become semi-organized. In the wake of the warm advection regime, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining MLCIN through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development should be sparse and may struggle to be sustained during the late afternoon/early evening. If surface-based storms can form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated severe wind and hail. ...Central Appalachians... A narrow corridor of weak to modest buoyancy is expected with scattered storms along a cold front and over the higher terrain through early evening. Isolated strong downburst winds are possible on the periphery of weak to moderate mid-level southwesterlies. ..Grams/Squitieri.. 09/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Sep 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTH-CENTRAL AZ... ...SUMMARY... Isolated to scattered severe wind gusts are possible this afternoon and evening across southern and central Arizona. Isolated severe storms with large hail and damaging wind gusts are possible from the Upper Midwest to the central Great Plains through tonight. ...Southern/central AZ... An MCV over western Chihuahua will drift north-northwestward across southeast AZ through tonight. 50s surface dew points are common across southern AZ amid easterly flow north of this MCV. In conjunction with ample heating northwest of the thicker cloud cover near the MCV, a modestly buoyant air mass with MLCAPE approaching 1000 J/kg should develop by peak heating. 15-25 kt east-northeast 700-500 mb winds around the north side of the MCV will be favorable for cells and semi-organized clusters to spread off the Mogollon Rim into the lower deserts with a threat for severe gusts. Whether more organized clustering can evolve is uncertain compared to the significant severe wind event two weeks ago, but there is at least sufficient damaging wind potential to warrant a Slight Risk across parts of the Gila Valley. ...Upper Midwest to the central Great Plains... Elevated thunderstorms are ongoing in western IA on the leading edge of a low-level warm theta-e advection plume. This plume and attendant zone of ascent will spread east-northeast across the Upper MS Valley into tonight in advance of a low-amplitude shortwave trough near the ND/MB border that will move east-southeast into Lake Superior. This elevated convection will pose a threat for isolated large hail, mainly this evening into tonight with a probable decay cycle this afternoon. A risk for locally damaging winds may also develop tonight towards the IA/IL/WI border region if a cluster can become semi-organized. In the wake of the warm advection regime, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining MLCIN through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development should be sparse and may struggle to be sustained during the late afternoon/early evening. If surface-based storms can form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated severe wind and hail. ...Central Appalachians... A narrow corridor of weak to modest buoyancy is expected with scattered storms along a cold front and over the higher terrain through early evening. Isolated strong downburst winds are possible on the periphery of weak to moderate mid-level southwesterlies. ..Grams/Squitieri.. 09/14/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1049 AM CDT Sat Sep 14 2019 Valid 141700Z - 151200Z The elevated area was expanded slightly southward along the Sierra Front as downslope winds will likely result in elevated conditions. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/14/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Sat Sep 14 2019/ ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by late tonight, as a downstream shortwave trough moves quickly across the northern Plains. At the surface, broad low pressure will remain in place across south-central Canada, with a surface trough extending into portions of the central/northern High Plains. ...Southern WY... Low-level westerly flow will become established across southern WY this afternoon, to the west of the surface trough over the central/northern High Plains. Drying/mixing within a westerly flow regime will result in minimum RH values dropping to 10-20% this afternoon, in conjunction with sustained winds of 15-25 mph. These conditions will result in elevated fire weather conditions, with the best chance of locally critical conditions expected across portions of southeast WY. ...Northwest Great Basin and Vicinity... In advance of the upper trough, a gradual increase in low-level southwesterly flow is expected across portions of the northwest Great Basin and vicinity. Sustained winds may approach or exceed 15 mph within a hot and dry airmass characterized by minimum RH values of 10-15%, resulting in the potential for elevated fire weather conditions. As flow continues to increase into Sunday morning, mid/high elevation regions that remain above the nocturnal inversion for a longer period of time may see elevated conditions persist into the overnight hours. ...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 1049 AM CDT Sat Sep 14 2019 Valid 141700Z - 151200Z The elevated area was expanded slightly southward along the Sierra Front as downslope winds will likely result in elevated conditions. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/14/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Sat Sep 14 2019/ ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by late tonight, as a downstream shortwave trough moves quickly across the northern Plains. At the surface, broad low pressure will remain in place across south-central Canada, with a surface trough extending into portions of the central/northern High Plains. ...Southern WY... Low-level westerly flow will become established across southern WY this afternoon, to the west of the surface trough over the central/northern High Plains. Drying/mixing within a westerly flow regime will result in minimum RH values dropping to 10-20% this afternoon, in conjunction with sustained winds of 15-25 mph. These conditions will result in elevated fire weather conditions, with the best chance of locally critical conditions expected across portions of southeast WY. ...Northwest Great Basin and Vicinity... In advance of the upper trough, a gradual increase in low-level southwesterly flow is expected across portions of the northwest Great Basin and vicinity. Sustained winds may approach or exceed 15 mph within a hot and dry airmass characterized by minimum RH values of 10-15%, resulting in the potential for elevated fire weather conditions. As flow continues to increase into Sunday morning, mid/high elevation regions that remain above the nocturnal inversion for a longer period of time may see elevated conditions persist into the overnight hours. ...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 1049 AM CDT Sat Sep 14 2019 Valid 141700Z - 151200Z The elevated area was expanded slightly southward along the Sierra Front as downslope winds will likely result in elevated conditions. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/14/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Sat Sep 14 2019/ ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by late tonight, as a downstream shortwave trough moves quickly across the northern Plains. At the surface, broad low pressure will remain in place across south-central Canada, with a surface trough extending into portions of the central/northern High Plains. ...Southern WY... Low-level westerly flow will become established across southern WY this afternoon, to the west of the surface trough over the central/northern High Plains. Drying/mixing within a westerly flow regime will result in minimum RH values dropping to 10-20% this afternoon, in conjunction with sustained winds of 15-25 mph. These conditions will result in elevated fire weather conditions, with the best chance of locally critical conditions expected across portions of southeast WY. ...Northwest Great Basin and Vicinity... In advance of the upper trough, a gradual increase in low-level southwesterly flow is expected across portions of the northwest Great Basin and vicinity. Sustained winds may approach or exceed 15 mph within a hot and dry airmass characterized by minimum RH values of 10-15%, resulting in the potential for elevated fire weather conditions. As flow continues to increase into Sunday morning, mid/high elevation regions that remain above the nocturnal inversion for a longer period of time may see elevated conditions persist into the overnight hours. ...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 1049 AM CDT Sat Sep 14 2019 Valid 141700Z - 151200Z The elevated area was expanded slightly southward along the Sierra Front as downslope winds will likely result in elevated conditions. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/14/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Sat Sep 14 2019/ ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by late tonight, as a downstream shortwave trough moves quickly across the northern Plains. At the surface, broad low pressure will remain in place across south-central Canada, with a surface trough extending into portions of the central/northern High Plains. ...Southern WY... Low-level westerly flow will become established across southern WY this afternoon, to the west of the surface trough over the central/northern High Plains. Drying/mixing within a westerly flow regime will result in minimum RH values dropping to 10-20% this afternoon, in conjunction with sustained winds of 15-25 mph. These conditions will result in elevated fire weather conditions, with the best chance of locally critical conditions expected across portions of southeast WY. ...Northwest Great Basin and Vicinity... In advance of the upper trough, a gradual increase in low-level southwesterly flow is expected across portions of the northwest Great Basin and vicinity. Sustained winds may approach or exceed 15 mph within a hot and dry airmass characterized by minimum RH values of 10-15%, resulting in the potential for elevated fire weather conditions. As flow continues to increase into Sunday morning, mid/high elevation regions that remain above the nocturnal inversion for a longer period of time may see elevated conditions persist into the overnight hours. ...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 1049 AM CDT Sat Sep 14 2019 Valid 141700Z - 151200Z The elevated area was expanded slightly southward along the Sierra Front as downslope winds will likely result in elevated conditions. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/14/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Sat Sep 14 2019/ ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by late tonight, as a downstream shortwave trough moves quickly across the northern Plains. At the surface, broad low pressure will remain in place across south-central Canada, with a surface trough extending into portions of the central/northern High Plains. ...Southern WY... Low-level westerly flow will become established across southern WY this afternoon, to the west of the surface trough over the central/northern High Plains. Drying/mixing within a westerly flow regime will result in minimum RH values dropping to 10-20% this afternoon, in conjunction with sustained winds of 15-25 mph. These conditions will result in elevated fire weather conditions, with the best chance of locally critical conditions expected across portions of southeast WY. ...Northwest Great Basin and Vicinity... In advance of the upper trough, a gradual increase in low-level southwesterly flow is expected across portions of the northwest Great Basin and vicinity. Sustained winds may approach or exceed 15 mph within a hot and dry airmass characterized by minimum RH values of 10-15%, resulting in the potential for elevated fire weather conditions. As flow continues to increase into Sunday morning, mid/high elevation regions that remain above the nocturnal inversion for a longer period of time may see elevated conditions persist into the overnight hours. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

5-Day Uncertainty Track last updated Sat, 14 Sep 2019 14:56:28 GMT


Wind Speed Probabilities last updated Sat, 14 Sep 2019 15:31:28 GMT

Issued at 800 AM PDT Sat Sep 14 2019 000 WTPZ43 KNHC 141455 TCDEP3 Tropical Storm Kiko Discussion Number 9 NWS National Hurricane Center Miami FL EP132019 800 AM PDT Sat Sep 14 2019 Kiko's cloud pattern has continued to quickly organize overnight and this morning. A couple of high-resolution microwave overpass from several hours ago revealed significant banding around the center, and that a banded eye had formed. Dvorak intensity estimates from TAFB and SAB at 1200 UTC were 55 kt, and the UW/CIMSS ADT is now up to about 60 kt. Based on the continued increase in organization, the initial intensity has been raised to 60 kt. Kiko is forecast to remain over warm water and in a low wind shear environment during the next day or so. This should allow for additional intensification, and Kiko is expected to become a hurricane later today. The new NHC intensity forecast shows a slightly higher peak intensity and is in best agreement with the HFIP corrected consensus model, which is at the upper-end of the guidance envelope. By 72 hours, Kiko will be moving into an area of increasing westerly shear and over slightly cooler waters. As a result, steady weakening is anticipated later in forecast period. The tropical storm is moving westward (280/9 kt) to the south of a mid-level ridge that extends westward from northern Mexico. The track models still exhibit an usually large spread after 48 hours, especially for a system in the eastern Pacific basin. This appears to be the result of the forecast vertical depth of Kiko and how the cyclone responds to a developing weakness in the ridge. The GFS, GFS ensemble mean, and HWRF show a more northerly track, with a stronger Kiko heading toward the break in the ridge. Meanwhile, the ECMWF and UKMET take a weaker Kiko on a more westerly heading. Since the NHC forecast shows Kiko a stronger and vertically deep system during the next couple of days, the track forecast lies a little north of the consensus models. After that time, Kiko is likely to weaken and the official forecast shows a turn back toward the west, as Kiko comes under the influence of the low-level easterly flow. As a result of the large model spread, the confidence in the track forecast remains lower than normal. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 17.4N 118.3W 60 KT 70 MPH 12H 15/0000Z 17.6N 119.5W 70 KT 80 MPH 24H 15/1200Z 17.9N 120.9W 75 KT 85 MPH 36H 16/0000Z 18.3N 122.1W 75 KT 85 MPH 48H 16/1200Z 18.8N 123.3W 70 KT 80 MPH 72H 17/1200Z 19.6N 125.5W 55 KT 65 MPH 96H 18/1200Z 20.3N 128.0W 40 KT 45 MPH 120H 19/1200Z 20.7N 131.0W 30 KT 35 MPH $$ Forecaster Brown

Issued at 1500 UTC SAT SEP 14 2019 000 FOPZ13 KNHC 141454 PWSEP3 TROPICAL STORM KIKO WIND SPEED PROBABILITIES NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132019 1500 UTC SAT SEP 14 2019 AT 1500Z THE CENTER OF TROPICAL STORM KIKO WAS LOCATED NEAR LATITUDE 17.4 NORTH...LONGITUDE 118.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 60 KTS...70 MPH...110 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z SAT AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z SAT 00Z SUN 12Z SUN 00Z MON 12Z MON 12Z TUE 12Z WED PERIODS TO TO TO TO TO TO TO 00Z SUN 12Z SUN 00Z MON 12Z MON 12Z TUE 12Z WED 12Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 15N 120W 34 2 3( 5) 3( 8) 1( 9) 1(10) X(10) X(10) 20N 120W 34 3 14(17) 7(24) 3(27) 2(29) X(29) X(29) 20N 120W 50 X 1( 1) 1( 2) 1( 3) X( 3) X( 3) X( 3) 15N 125W 34 X 1( 1) 2( 3) 2( 5) 4( 9) 1(10) X(10) 20N 125W 34 X 2( 2) 4( 6) 23(29) 36(65) 4(69) 1(70) 20N 125W 50 X X( X) X( X) 3( 3) 24(27) 2(29) X(29) 20N 125W 64 X X( X) X( X) 1( 1) 9(10) 1(11) X(11) 25N 125W 34 X X( X) X( X) X( X) 2( 2) 1( 3) X( 3) 20N 130W 34 X X( X) X( X) X( X) 3( 3) 8(11) 6(17) $$ FORECASTER BROWN

Issued at 800 AM PDT Sat Sep 14 2019 000 WTPZ33 KNHC 141453 TCPEP3 BULLETIN Tropical Storm Kiko Advisory Number 9 NWS National Hurricane Center Miami FL EP132019 800 AM PDT Sat Sep 14 2019 ...KIKO QUICKLY STRENGTHENS... ...EXPECTED TO BECOME A HURRICANE LATER TODAY... SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...17.4N 118.3W ABOUT 665 MI...1070 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 800 AM PDT (1500 UTC), the center of Tropical Storm Kiko was located near latitude 17.4 North, longitude 118.3 West. Kiko is moving toward the west near 10 mph (17 km/h). A westward or west-northwestward course at a slightly slower forward speed is expected during the next several days. Maximum sustained winds have increased to near 70 mph (110 km/h) with higher gusts. Additional strengthening is forecast during the next couple of days, and Kiko is expected to become a hurricane by tonight and maintain hurricane intensity into Monday. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. The estimated minimum central pressure is 992 mb (29.30 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 200 PM PDT. $$ Forecaster Brown

...KIKO QUICKLY STRENGTHENS... ...EXPECTED TO BECOME A HURRICANE LATER TODAY... As of 8:00 AM PDT Sat Sep 14 the center of Kiko was located near 17.4, -118.3 with movement W at 10 mph. The minimum central pressure was 992 mb with maximum sustained winds of about 70 mph.

Issued at 1500 UTC SAT SEP 14 2019 000 WTPZ23 KNHC 141453 TCMEP3 TROPICAL STORM KIKO FORECAST/ADVISORY NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132019 1500 UTC SAT SEP 14 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. TROPICAL STORM CENTER LOCATED NEAR 17.4N 118.3W AT 14/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 992 MB MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT. 50 KT....... 30NE 20SE 0SW 20NW. 34 KT....... 70NE 50SE 40SW 70NW. 12 FT SEAS.. 60NE 30SE 60SW 90NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 17.4N 118.3W AT 14/1500Z AT 14/1200Z CENTER WAS LOCATED NEAR 17.4N 117.9W FORECAST VALID 15/0000Z 17.6N 119.5W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 20NE 15SE 0SW 15NW. 50 KT... 40NE 30SE 20SW 30NW. 34 KT... 70NE 60SE 40SW 70NW. FORECAST VALID 15/1200Z 17.9N 120.9W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 20NE 15SE 10SW 20NW. 50 KT... 40NE 30SE 20SW 40NW. 34 KT... 70NE 60SE 40SW 70NW. FORECAST VALID 16/0000Z 18.3N 122.1W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 20NE 15SE 10SW 20NW. 50 KT... 40NE 30SE 20SW 40NW. 34 KT... 70NE 60SE 40SW 70NW. FORECAST VALID 16/1200Z 18.8N 123.3W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 20NE 15SE 10SW 20NW. 50 KT... 40NE 30SE 20SW 40NW. 34 KT... 70NE 60SE 40SW 70NW. FORECAST VALID 17/1200Z 19.6N 125.5W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 40NE 30SE 20SW 40NW. 34 KT... 70NE 70SE 50SW 70NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 150 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 18/1200Z 20.3N 128.0W MAX WIND 40 KT...GUSTS 50 KT. OUTLOOK VALID 19/1200Z 20.7N 131.0W MAX WIND 30 KT...GUSTS 40 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.4N 118.3W NEXT ADVISORY AT 14/2100Z $$ FORECASTER BROWN