Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Fri Sep 13 2019 Valid 131630Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTHEAST LOWER MI TO NORTHERN OH... ...SUMMARY... Scattered damaging winds, a couple tornadoes, and isolated severe hail are possible across southeast Lower Michigan into northern Ohio through about 9 PM EDT. ...MI/OH/IN... An upper low over northwest ON will evolve into an open wave while moving northeastward towards James Bay, as embedded speed maxima rotate around the southeastern periphery of the low. At the surface, a cold front arcing into far southwest Lower MI to the Wabash Valley will progress east across the rest of IN/Lower MI. Thick overcast and residual stratiform rain have tempered destabilization ahead of the front across most of Lower MI, except across the southeast portion with nearly cloud-free insolation occurring from there southward across much of OH and eastern IN. Surface temperatures were already warming through the 80s and will reach the low 90s across most of OH where surface dew points should mix down into the low 60s. A confined corridor of upper 60s dew points should remain near the front and where boundary-layer mixing is not quite as pronounced across southeast Lower MI. Scattered storms are expected to develop in the next couple hours near the front, and then continue eastward across Lake Erie and parts of northern OH into this evening. Despite being on the southeast periphery of the Upper Great Lakes mid-level jet, largely unidirectional/veered wind profiles should hold effective shear to between 25-40 kts. The greatest potential for supercells will exist across southeast Lower MI where the low-level hodograph should be adequately enlarged, yielding a short-duration risk for a couple tornadoes before surface winds veer. Modest mid-level lapse rates will probably limit hail magnitudes. Scattered damaging winds should be the primary hazard with this threat likely diminishing shortly after dusk. ...Western NC into SC... Strong surface heating and lingering low-level moisture along and southwest of a reinforcing frontal surge could provide some focus for thunderstorm development this afternoon. Thermodynamic profiles will favor some risk for damaging downbursts given DCAPE values near 1000 J/kg. Minimal deep-layer shear will temper the potential for organized clustering. ..Grams/Dial.. 09/13/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1101 AM CDT Fri Sep 13 2019 Valid 131700Z - 141200Z The elevated area was expanded farther west in the Santa Ynez Mountains and closer to the coast near Santa Barbara/vicinity with dry/breezy conditions continuing this afternoon/evening and possibly overnight. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/13/2019 .PREV DISCUSSION... /ISSUED 0200 AM CDT Fri Sep 13 2019/ ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ...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 1101 AM CDT Fri Sep 13 2019 Valid 131700Z - 141200Z The elevated area was expanded farther west in the Santa Ynez Mountains and closer to the coast near Santa Barbara/vicinity with dry/breezy conditions continuing this afternoon/evening and possibly overnight. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/13/2019 .PREV DISCUSSION... /ISSUED 0200 AM CDT Fri Sep 13 2019/ ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ...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 1101 AM CDT Fri Sep 13 2019 Valid 131700Z - 141200Z The elevated area was expanded farther west in the Santa Ynez Mountains and closer to the coast near Santa Barbara/vicinity with dry/breezy conditions continuing this afternoon/evening and possibly overnight. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/13/2019 .PREV DISCUSSION... /ISSUED 0200 AM CDT Fri Sep 13 2019/ ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ...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 1101 AM CDT Fri Sep 13 2019 Valid 131700Z - 141200Z The elevated area was expanded farther west in the Santa Ynez Mountains and closer to the coast near Santa Barbara/vicinity with dry/breezy conditions continuing this afternoon/evening and possibly overnight. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 09/13/2019 .PREV DISCUSSION... /ISSUED 0200 AM CDT Fri Sep 13 2019/ ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0739 AM CDT Fri Sep 13 2019 Valid 131300Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST LOWER MI INTO NORTHERN OH... ...SUMMARY... A few severe thunderstorms with damaging winds are expected from southeast Lower Michigan into northern Ohio this afternoon. ...Southeast Lower MI into IN/OH this afternoon/evening... A midlevel low over northern MN is evolving into an open wave while moving northeastward towards James Bay, as embedded speed maxima rotate around the southeastern periphery of the low. At the surface, a cold front will progress eastward across IN/Lower MI during the day, and the warm sector will spread northeastward into southeast Lower MI ahead of the front. A corridor of surface heating is expected from IN/OH into southeast Lower MI, to the southeast of the thicker clouds associated with ongoing (pre-frontal) convection from northeast IL to central Lower MI. Midlevel lapse rates will remain rather modest (less than 7 C/km) within the warm sector today. Still, surface temperatures warming to near 80 F in southeast Lower MI and well into the 80s across IN/OH, in combination with 68-70 F boundary-layer dewpoints, will result in MLCAPE of 1000-1500 J/kg. Storms are expected to form by early afternoon from northeast IN into southeast Lower MI, and then continue eastward across northern OH into this evening. Diurnal destabilization will coincide with an increase in midlevel flow/vertical shear, which will support both organized storm clusters/supercells along the cold front with a primary threat for damaging winds. A low-end tornado threat is expected from southeast Lower MI into northern OH where low-level shear/hodograph curvature will be greater near the surface warm front this afternoon/evening. The severe threat will diminish to the south in conjunction with weakening vertical shear. ...Western NC into SC this afternoon... Strong surface heating and lingering low-level moisture along and southwest of a reinforcing frontal surge could provide some focus for thunderstorm development this afternoon. Thermodynamic profiles will favor some potential for isolated damaging downbursts given DCAPE values near 1000 J/kg. ...Southeast FL coast today... Convection with gusty winds will be possible along the southeast FL coast, where northeasterly low-level winds will increase to about 30 kt around the northwest periphery of a tropical disturbance near the southeast Bahamas. Moist profiles, however, should limit the potential stronger/damaging outflow winds. ..Thompson/Gleason.. 09/13/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0739 AM CDT Fri Sep 13 2019 Valid 131300Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST LOWER MI INTO NORTHERN OH... ...SUMMARY... A few severe thunderstorms with damaging winds are expected from southeast Lower Michigan into northern Ohio this afternoon. ...Southeast Lower MI into IN/OH this afternoon/evening... A midlevel low over northern MN is evolving into an open wave while moving northeastward towards James Bay, as embedded speed maxima rotate around the southeastern periphery of the low. At the surface, a cold front will progress eastward across IN/Lower MI during the day, and the warm sector will spread northeastward into southeast Lower MI ahead of the front. A corridor of surface heating is expected from IN/OH into southeast Lower MI, to the southeast of the thicker clouds associated with ongoing (pre-frontal) convection from northeast IL to central Lower MI. Midlevel lapse rates will remain rather modest (less than 7 C/km) within the warm sector today. Still, surface temperatures warming to near 80 F in southeast Lower MI and well into the 80s across IN/OH, in combination with 68-70 F boundary-layer dewpoints, will result in MLCAPE of 1000-1500 J/kg. Storms are expected to form by early afternoon from northeast IN into southeast Lower MI, and then continue eastward across northern OH into this evening. Diurnal destabilization will coincide with an increase in midlevel flow/vertical shear, which will support both organized storm clusters/supercells along the cold front with a primary threat for damaging winds. A low-end tornado threat is expected from southeast Lower MI into northern OH where low-level shear/hodograph curvature will be greater near the surface warm front this afternoon/evening. The severe threat will diminish to the south in conjunction with weakening vertical shear. ...Western NC into SC this afternoon... Strong surface heating and lingering low-level moisture along and southwest of a reinforcing frontal surge could provide some focus for thunderstorm development this afternoon. Thermodynamic profiles will favor some potential for isolated damaging downbursts given DCAPE values near 1000 J/kg. ...Southeast FL coast today... Convection with gusty winds will be possible along the southeast FL coast, where northeasterly low-level winds will increase to about 30 kt around the northwest periphery of a tropical disturbance near the southeast Bahamas. Moist profiles, however, should limit the potential stronger/damaging outflow winds. ..Thompson/Gleason.. 09/13/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0739 AM CDT Fri Sep 13 2019 Valid 131300Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST LOWER MI INTO NORTHERN OH... ...SUMMARY... A few severe thunderstorms with damaging winds are expected from southeast Lower Michigan into northern Ohio this afternoon. ...Southeast Lower MI into IN/OH this afternoon/evening... A midlevel low over northern MN is evolving into an open wave while moving northeastward towards James Bay, as embedded speed maxima rotate around the southeastern periphery of the low. At the surface, a cold front will progress eastward across IN/Lower MI during the day, and the warm sector will spread northeastward into southeast Lower MI ahead of the front. A corridor of surface heating is expected from IN/OH into southeast Lower MI, to the southeast of the thicker clouds associated with ongoing (pre-frontal) convection from northeast IL to central Lower MI. Midlevel lapse rates will remain rather modest (less than 7 C/km) within the warm sector today. Still, surface temperatures warming to near 80 F in southeast Lower MI and well into the 80s across IN/OH, in combination with 68-70 F boundary-layer dewpoints, will result in MLCAPE of 1000-1500 J/kg. Storms are expected to form by early afternoon from northeast IN into southeast Lower MI, and then continue eastward across northern OH into this evening. Diurnal destabilization will coincide with an increase in midlevel flow/vertical shear, which will support both organized storm clusters/supercells along the cold front with a primary threat for damaging winds. A low-end tornado threat is expected from southeast Lower MI into northern OH where low-level shear/hodograph curvature will be greater near the surface warm front this afternoon/evening. The severe threat will diminish to the south in conjunction with weakening vertical shear. ...Western NC into SC this afternoon... Strong surface heating and lingering low-level moisture along and southwest of a reinforcing frontal surge could provide some focus for thunderstorm development this afternoon. Thermodynamic profiles will favor some potential for isolated damaging downbursts given DCAPE values near 1000 J/kg. ...Southeast FL coast today... Convection with gusty winds will be possible along the southeast FL coast, where northeasterly low-level winds will increase to about 30 kt around the northwest periphery of a tropical disturbance near the southeast Bahamas. Moist profiles, however, should limit the potential stronger/damaging outflow winds. ..Thompson/Gleason.. 09/13/2019 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0343 AM CDT Fri Sep 13 2019 Valid 161200Z - 211200Z ...DISCUSSION... The medium-range models generally indicate that a significant short wave impulse will emerge from the base of initially amplified large-scale mid-level troughing, near the Pacific coast at the start of the period. It appears probable that this perturbation will accelerate northeastward across the northern Rockies and Plains, and north of the international border by Wednesday night, accompanied by modest surface cyclogenesis from eastern Montana through the Hudson Bay vicinity. This seems to provide the primary focus for any appreciable severe thunderstorm potential across the U.S. during this period, which could impact areas from the immediate lee of the northern Rockies into the northern Plains Tuesday through Tuesday night, and portions of the Upper Midwest on Wednesday. However, the extent of this potential remains unclear at this time, and may considerably hinge on sub-synoptic developments with low predictability in this extended forecast time frame. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0343 AM CDT Fri Sep 13 2019 Valid 161200Z - 211200Z ...DISCUSSION... The medium-range models generally indicate that a significant short wave impulse will emerge from the base of initially amplified large-scale mid-level troughing, near the Pacific coast at the start of the period. It appears probable that this perturbation will accelerate northeastward across the northern Rockies and Plains, and north of the international border by Wednesday night, accompanied by modest surface cyclogenesis from eastern Montana through the Hudson Bay vicinity. This seems to provide the primary focus for any appreciable severe thunderstorm potential across the U.S. during this period, which could impact areas from the immediate lee of the northern Rockies into the northern Plains Tuesday through Tuesday night, and portions of the Upper Midwest on Wednesday. However, the extent of this potential remains unclear at this time, and may considerably hinge on sub-synoptic developments with low predictability in this extended forecast time frame. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0343 AM CDT Fri Sep 13 2019 Valid 161200Z - 211200Z ...DISCUSSION... The medium-range models generally indicate that a significant short wave impulse will emerge from the base of initially amplified large-scale mid-level troughing, near the Pacific coast at the start of the period. It appears probable that this perturbation will accelerate northeastward across the northern Rockies and Plains, and north of the international border by Wednesday night, accompanied by modest surface cyclogenesis from eastern Montana through the Hudson Bay vicinity. This seems to provide the primary focus for any appreciable severe thunderstorm potential across the U.S. during this period, which could impact areas from the immediate lee of the northern Rockies into the northern Plains Tuesday through Tuesday night, and portions of the Upper Midwest on Wednesday. However, the extent of this potential remains unclear at this time, and may considerably hinge on sub-synoptic developments with low predictability in this extended forecast time frame. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CDT Fri Sep 13 2019 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY NEAR NORTHEAST FLORIDA AND GEORGIA ATLANTIC COASTAL AREAS... ...SUMMARY... Shower and thunderstorm activity associated with a tropical system may pose at least some risk for isolated tornadoes and potentially damaging wind gusts near northeast Florida and Georgia coastal areas Sunday. ...Discussion... Models indicate substantial further amplification within the westerlies during this period, including digging upper troughing near the Pacific coast, and building of much broader downstream ridging across and north of the central Canadian/U.S. border area. Remnant mid-level troughing over eastern Canada is forecast to dig southeastward across the Canadian Maritimes and northern U.S. Atlantic coast. In lower latitudes, a tropical storm may track inland of east central Florida coastal areas through northeastern Florida Sunday through Sunday night, while another perturbation continues to slowly progress through easterly flow across the western Gulf of Mexico into Texas coastal plain. One or two additional perturbations may develop northward around the western periphery of subtropical ridging, to the east of the Pacific coast troughing, across the southern Rockies into the northern Plains. Each of these features may provide support for areas of scattered thunderstorm activity Sunday and Sunday night. However, it seems probable that any appreciable severe weather potential will be limited to convective development associated with the possible tropical storm. This will considerably hinge on the track of the storm, but could include a risk for isolated tornadoes, in addition to potentially damaging wind gusts. Across the Upper Midwest and Great Lakes region, thunderstorm probabilities appear generally low and mostly in association with remnant convection from Saturday night, driven largely by warm advection. This may continue into early Sunday, before thunderstorm potential becomes more unclear as mid-level ridging builds into the region. ..Kerr.. 09/13/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CDT Fri Sep 13 2019 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY NEAR NORTHEAST FLORIDA AND GEORGIA ATLANTIC COASTAL AREAS... ...SUMMARY... Shower and thunderstorm activity associated with a tropical system may pose at least some risk for isolated tornadoes and potentially damaging wind gusts near northeast Florida and Georgia coastal areas Sunday. ...Discussion... Models indicate substantial further amplification within the westerlies during this period, including digging upper troughing near the Pacific coast, and building of much broader downstream ridging across and north of the central Canadian/U.S. border area. Remnant mid-level troughing over eastern Canada is forecast to dig southeastward across the Canadian Maritimes and northern U.S. Atlantic coast. In lower latitudes, a tropical storm may track inland of east central Florida coastal areas through northeastern Florida Sunday through Sunday night, while another perturbation continues to slowly progress through easterly flow across the western Gulf of Mexico into Texas coastal plain. One or two additional perturbations may develop northward around the western periphery of subtropical ridging, to the east of the Pacific coast troughing, across the southern Rockies into the northern Plains. Each of these features may provide support for areas of scattered thunderstorm activity Sunday and Sunday night. However, it seems probable that any appreciable severe weather potential will be limited to convective development associated with the possible tropical storm. This will considerably hinge on the track of the storm, but could include a risk for isolated tornadoes, in addition to potentially damaging wind gusts. Across the Upper Midwest and Great Lakes region, thunderstorm probabilities appear generally low and mostly in association with remnant convection from Saturday night, driven largely by warm advection. This may continue into early Sunday, before thunderstorm potential becomes more unclear as mid-level ridging builds into the region. ..Kerr.. 09/13/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0204 AM CDT Fri Sep 13 2019 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY NEAR NORTHEAST FLORIDA AND GEORGIA ATLANTIC COASTAL AREAS... ...SUMMARY... Shower and thunderstorm activity associated with a tropical system may pose at least some risk for isolated tornadoes and potentially damaging wind gusts near northeast Florida and Georgia coastal areas Sunday. ...Discussion... Models indicate substantial further amplification within the westerlies during this period, including digging upper troughing near the Pacific coast, and building of much broader downstream ridging across and north of the central Canadian/U.S. border area. Remnant mid-level troughing over eastern Canada is forecast to dig southeastward across the Canadian Maritimes and northern U.S. Atlantic coast. In lower latitudes, a tropical storm may track inland of east central Florida coastal areas through northeastern Florida Sunday through Sunday night, while another perturbation continues to slowly progress through easterly flow across the western Gulf of Mexico into Texas coastal plain. One or two additional perturbations may develop northward around the western periphery of subtropical ridging, to the east of the Pacific coast troughing, across the southern Rockies into the northern Plains. Each of these features may provide support for areas of scattered thunderstorm activity Sunday and Sunday night. However, it seems probable that any appreciable severe weather potential will be limited to convective development associated with the possible tropical storm. This will considerably hinge on the track of the storm, but could include a risk for isolated tornadoes, in addition to potentially damaging wind gusts. Across the Upper Midwest and Great Lakes region, thunderstorm probabilities appear generally low and mostly in association with remnant convection from Saturday night, driven largely by warm advection. This may continue into early Sunday, before thunderstorm potential becomes more unclear as mid-level ridging builds into the region. ..Kerr.. 09/13/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Fri Sep 13 2019 Valid 141200Z - 151200Z ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by Saturday evening, with largely zonal flow expected further east across the interior Northwest into 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 northern Plains. ...Southeast WY... Low-level westerly flow will become established across southern WY by Saturday afternoon, to the west of the surface trough over the northern Plains. While there remains some variability among model guidance regarding the strength of low-level flow, sustained surface winds of 15-25 mph (with higher gusts) combined with minimum RH values of 10-20% will likely result in elevated to locally critical conditions across portions of southeast WY. ..Dean.. 09/13/2019 ...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 0200 AM CDT Fri Sep 13 2019 Valid 141200Z - 151200Z ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by Saturday evening, with largely zonal flow expected further east across the interior Northwest into 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 northern Plains. ...Southeast WY... Low-level westerly flow will become established across southern WY by Saturday afternoon, to the west of the surface trough over the northern Plains. While there remains some variability among model guidance regarding the strength of low-level flow, sustained surface winds of 15-25 mph (with higher gusts) combined with minimum RH values of 10-20% will likely result in elevated to locally critical conditions across portions of southeast WY. ..Dean.. 09/13/2019 ...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 0200 AM CDT Fri Sep 13 2019 Valid 141200Z - 151200Z ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by Saturday evening, with largely zonal flow expected further east across the interior Northwest into 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 northern Plains. ...Southeast WY... Low-level westerly flow will become established across southern WY by Saturday afternoon, to the west of the surface trough over the northern Plains. While there remains some variability among model guidance regarding the strength of low-level flow, sustained surface winds of 15-25 mph (with higher gusts) combined with minimum RH values of 10-20% will likely result in elevated to locally critical conditions across portions of southeast WY. ..Dean.. 09/13/2019 ...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 0200 AM CDT Fri Sep 13 2019 Valid 131200Z - 141200Z ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ..Dean.. 09/13/2019 ...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 0200 AM CDT Fri Sep 13 2019 Valid 131200Z - 141200Z ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ..Dean.. 09/13/2019 ...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 0200 AM CDT Fri Sep 13 2019 Valid 131200Z - 141200Z ...Synopsis... A seasonably strong upper trough over the upper Midwest will progress eastward through the period, while a lower-amplitude trough will move quickly eastward from the northern Rockies into the northern Plains by Saturday morning. At the surface, high pressure centered over the central Rockies is expected to gradually weaken, while a weak surface low moves eastward across the southern Canadian Prairies. ...Southern California... Elevated fire weather conditions may be ongoing at the start of the period across portions of southern CA, within a weak offshore flow regime. Some weakening of the offshore gradient is expected later today, resulting in a general decrease in wind speeds, though very warm and dry conditions will persist, with poor overnight RH recovery into Saturday morning. ..Dean.. 09/13/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more