Aggregator

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Sun Sep 01 2019 Valid 011200Z - 021200Z ...Synopsis... An upper-level ridge will prevail across the western CONUS throughout the day, with an intensifying mid-level impulse beginning to crest the ridge, across the Pacific Northwest/northern Rockies regions by the end of the period. The resultant strengthening flow aloft by peak heating may be transported downward via a deep, mixed boundary layer, promoting dry and breezy conditions which may foster some threat for wildfire-spread. ...Northern Great Basin into the central Rockies... Downslope flow and boundary layer mixing of the winds aloft will result in 15-20 mph sustained west-southwesterly surface winds and 10-20% RH, from parts of the Snake River Plain into the Great Divide Basin. An elevated area has been maintained for regions where the aforementioned breezy, dry surface conditions are expected to persist for several hours during the afternoon. Fuels across this area are also quite supportive of wildfire-spread potential. Farther west-southwest into parts of the Great Basin, at least localized to briefly widespread elevated conditions may be observed, but the patchy or brief nature of such conditions precludes a delineation at this time. ...Central into southern Colorado and far northwest New Mexico... A couple of thunderstorms may initiate atop the higher terrain of the Rocky Mountains across parts of central Colorado into Northwest New Mexico during the afternoon hours. These storms may be high-based in nature, with a couple of dry strikes possible, and where fuels are marginally to modestly receptive to fire spread. The very sparse nature of dry strikes renders an isolated dry thunderstorm delineation unwarranted at this time. ..Squitieri.. 09/01/2019 ...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 1241 AM CDT Sun Sep 01 2019 Valid 011200Z - 021200Z ...Synopsis... An upper-level ridge will prevail across the western CONUS throughout the day, with an intensifying mid-level impulse beginning to crest the ridge, across the Pacific Northwest/northern Rockies regions by the end of the period. The resultant strengthening flow aloft by peak heating may be transported downward via a deep, mixed boundary layer, promoting dry and breezy conditions which may foster some threat for wildfire-spread. ...Northern Great Basin into the central Rockies... Downslope flow and boundary layer mixing of the winds aloft will result in 15-20 mph sustained west-southwesterly surface winds and 10-20% RH, from parts of the Snake River Plain into the Great Divide Basin. An elevated area has been maintained for regions where the aforementioned breezy, dry surface conditions are expected to persist for several hours during the afternoon. Fuels across this area are also quite supportive of wildfire-spread potential. Farther west-southwest into parts of the Great Basin, at least localized to briefly widespread elevated conditions may be observed, but the patchy or brief nature of such conditions precludes a delineation at this time. ...Central into southern Colorado and far northwest New Mexico... A couple of thunderstorms may initiate atop the higher terrain of the Rocky Mountains across parts of central Colorado into Northwest New Mexico during the afternoon hours. These storms may be high-based in nature, with a couple of dry strikes possible, and where fuels are marginally to modestly receptive to fire spread. The very sparse nature of dry strikes renders an isolated dry thunderstorm delineation unwarranted at this time. ..Squitieri.. 09/01/2019 ...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 1241 AM CDT Sun Sep 01 2019 Valid 011200Z - 021200Z ...Synopsis... An upper-level ridge will prevail across the western CONUS throughout the day, with an intensifying mid-level impulse beginning to crest the ridge, across the Pacific Northwest/northern Rockies regions by the end of the period. The resultant strengthening flow aloft by peak heating may be transported downward via a deep, mixed boundary layer, promoting dry and breezy conditions which may foster some threat for wildfire-spread. ...Northern Great Basin into the central Rockies... Downslope flow and boundary layer mixing of the winds aloft will result in 15-20 mph sustained west-southwesterly surface winds and 10-20% RH, from parts of the Snake River Plain into the Great Divide Basin. An elevated area has been maintained for regions where the aforementioned breezy, dry surface conditions are expected to persist for several hours during the afternoon. Fuels across this area are also quite supportive of wildfire-spread potential. Farther west-southwest into parts of the Great Basin, at least localized to briefly widespread elevated conditions may be observed, but the patchy or brief nature of such conditions precludes a delineation at this time. ...Central into southern Colorado and far northwest New Mexico... A couple of thunderstorms may initiate atop the higher terrain of the Rocky Mountains across parts of central Colorado into Northwest New Mexico during the afternoon hours. These storms may be high-based in nature, with a couple of dry strikes possible, and where fuels are marginally to modestly receptive to fire spread. The very sparse nature of dry strikes renders an isolated dry thunderstorm delineation unwarranted at this time. ..Squitieri.. 09/01/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

000
ABPZ20 KNHC 010533
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sat Aug 31 2019

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

Showers and thunderstorms are showing signs of organization and a
tropical cyclone could be forming several hundred miles southwest
of Manzanillo, Mexico. Recent satellite-derived winds indicate that
this low pressure system is already producing surface winds to near
tropical storm force east of the center. Environmental conditions
are conducive for further development, and a tropical depression or
a tropical storm is likely to form on Sunday while the system moves
west-northwestward to northwestward at around 10 mph. For additional
information see High Seas Forecasts issued by the National Weather
Service.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Stewart

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0755 PM CDT Sat Aug 31 2019 Valid 010100Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely through the remainder of this evening and overnight. ...01Z Update... Isolated strong to severe storms that formed earlier today along a weak surface boundary across parts of KY, WV, and far western VA will continue to weaken this evening with the loss of diurnal heating and gradual reduction in instability. While occasional strong/gusty downdraft winds may be possible for the next hour or two, overall severe potential is expected to continue decreasing. Have therefore removed 5% hail/wind probabilities from this region. Weak low-level warm advection may encourage isolated storms to form across southeastern SD and vicinity later this evening and continuing through the overnight hours. Although northwesterly winds are forecast to strengthen through mid and upper-levels, mid-level lapse rates should remain modest. This will limit MUCAPE available to any elevated convection that forms, with minimal severe hail threat anticipated. Isolated to scattered showers and storms should develop this evening and overnight across parts of the mid MS Valley into the Midwest as a weak shortwave trough moves eastward across these areas. Although some modest enhancement to the mid-level flow will exist, instability will be weak, and storms will probably remain elevated above a stable boundary layer. A robust storm that developed earlier this evening across far northern CO in a weak low-level upslope flow regime has since weakened. Upper ridging remains prominent across the Rockies, and any additional storms that form in this environment will likely weaken with southward extent as convective inhibition rapidly increases with the onset of nocturnal cooling. Elsewhere, isolated to scattered convection may continue this evening and into the overnight hours across parts of the Southeast and southern High Plains. Weak shear across these regions should greatly limit any organized severe storm potential. ..Gleason.. 09/01/2019 Read more

000
ABPZ20 KNHC 010004
TWOEP

Tropical Weather Outlook...Corrected
NWS National Hurricane Center Miami FL
500 PM PDT Sat Aug 31 2019

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

Updated to include High Seas Forecasts reference

Showers and thunderstorms continue to become better organized in
association with a broad area of low pressure located several
hundred miles south-southwest of Manzanillo, Mexico. Environmental
conditions appear conducive for further development of this system,
and a tropical depression is expected to form during the next day
or so while the system moves west-northwestward at 10 to 15 mph.
For additional information see High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Cangialosi

No watches are valid as of Sat Aug 31 23:43:02 UTC 2019.

No Mesoscale Discussions are in effect as of Sat Aug 31 23:43:02 UTC 2019.

000
ABPZ20 KNHC 312316
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sat Aug 31 2019

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

Showers and thunderstorms continue to become better organized in
association with a broad area of low pressure located several
hundred miles south-southwest of Manzanillo, Mexico. Environmental
conditions appear conducive for further development of this system,
and a tropical depression is expected to form during the next day
or so while the system moves west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

$$
Forecaster Cangialosi

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Aug 31 2019 Valid 312000Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN KENTUCKY INTO FAR WEST-CENTRAL VIRGINIA... ...SUMMARY... A few strong storms are possible across parts of the Ohio Valley to central Appalachians this afternoon. No significant changes were made to the previous outlook. Only isolated storms are expected along the east-west instability axis from northern KY into far western VA, aided by strong heating. 18Z soundings indicate a subsidence inversion aloft, and weak shear, with only short lived, marginal wind or hail expected. ..Jewell.. 08/31/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Aug 31 2019/ ...Ohio Valley to central Appalachians... Robust boundary-layer heating near a weakly convergent quasi-stationary front, ahead of a decaying mid-level impulse, should aid in isolated thunderstorms forming by mid afternoon. A confined corridor of modest buoyancy should develop, characterized by MLCAPE of 1000-1500 J/kg. While low-level winds will be weak, a belt of 25-30 kt 500-mb southwesterlies should support transient updraft rotation in a few cells. This may yield locally strong wind gusts along with marginally severe hail. ...Northern Nebraska to southern/eastern South Dakota... While overall forcing for ascent will be limited, sufficient moist/convergence could influence isolated thunderstorm development near a weak surface/boundary across northern Nebraska/southern South Dakota. If storms develop, a severe storm or two cannot be entirely ruled out given adequate buoyancy and moderately strong northwesterly flow aloft. Storms are a bit more likely to develop later tonight across eastern South Dakota with increasing warm advection, although hail potential will tend to be limited by modest mid-level lapse rates. Overall scenario across the region currently appears too marginal/uncertain to warrant severe probabilities. ...Southern Arizona... An isolated storm or two could develop over/near the mountains of southeast Arizona this afternoon and drift generally westward. However, storm organization should be limited by weaker mid-level winds, while the strongest updrafts should be relegated to south of the international border. As such, severe wind probabilities do not appear warranted. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Aug 31 2019 Valid 312000Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN KENTUCKY INTO FAR WEST-CENTRAL VIRGINIA... ...SUMMARY... A few strong storms are possible across parts of the Ohio Valley to central Appalachians this afternoon. No significant changes were made to the previous outlook. Only isolated storms are expected along the east-west instability axis from northern KY into far western VA, aided by strong heating. 18Z soundings indicate a subsidence inversion aloft, and weak shear, with only short lived, marginal wind or hail expected. ..Jewell.. 08/31/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Aug 31 2019/ ...Ohio Valley to central Appalachians... Robust boundary-layer heating near a weakly convergent quasi-stationary front, ahead of a decaying mid-level impulse, should aid in isolated thunderstorms forming by mid afternoon. A confined corridor of modest buoyancy should develop, characterized by MLCAPE of 1000-1500 J/kg. While low-level winds will be weak, a belt of 25-30 kt 500-mb southwesterlies should support transient updraft rotation in a few cells. This may yield locally strong wind gusts along with marginally severe hail. ...Northern Nebraska to southern/eastern South Dakota... While overall forcing for ascent will be limited, sufficient moist/convergence could influence isolated thunderstorm development near a weak surface/boundary across northern Nebraska/southern South Dakota. If storms develop, a severe storm or two cannot be entirely ruled out given adequate buoyancy and moderately strong northwesterly flow aloft. Storms are a bit more likely to develop later tonight across eastern South Dakota with increasing warm advection, although hail potential will tend to be limited by modest mid-level lapse rates. Overall scenario across the region currently appears too marginal/uncertain to warrant severe probabilities. ...Southern Arizona... An isolated storm or two could develop over/near the mountains of southeast Arizona this afternoon and drift generally westward. However, storm organization should be limited by weaker mid-level winds, while the strongest updrafts should be relegated to south of the international border. As such, severe wind probabilities do not appear warranted. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Aug 31 2019 Valid 312000Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN KENTUCKY INTO FAR WEST-CENTRAL VIRGINIA... ...SUMMARY... A few strong storms are possible across parts of the Ohio Valley to central Appalachians this afternoon. No significant changes were made to the previous outlook. Only isolated storms are expected along the east-west instability axis from northern KY into far western VA, aided by strong heating. 18Z soundings indicate a subsidence inversion aloft, and weak shear, with only short lived, marginal wind or hail expected. ..Jewell.. 08/31/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Aug 31 2019/ ...Ohio Valley to central Appalachians... Robust boundary-layer heating near a weakly convergent quasi-stationary front, ahead of a decaying mid-level impulse, should aid in isolated thunderstorms forming by mid afternoon. A confined corridor of modest buoyancy should develop, characterized by MLCAPE of 1000-1500 J/kg. While low-level winds will be weak, a belt of 25-30 kt 500-mb southwesterlies should support transient updraft rotation in a few cells. This may yield locally strong wind gusts along with marginally severe hail. ...Northern Nebraska to southern/eastern South Dakota... While overall forcing for ascent will be limited, sufficient moist/convergence could influence isolated thunderstorm development near a weak surface/boundary across northern Nebraska/southern South Dakota. If storms develop, a severe storm or two cannot be entirely ruled out given adequate buoyancy and moderately strong northwesterly flow aloft. Storms are a bit more likely to develop later tonight across eastern South Dakota with increasing warm advection, although hail potential will tend to be limited by modest mid-level lapse rates. Overall scenario across the region currently appears too marginal/uncertain to warrant severe probabilities. ...Southern Arizona... An isolated storm or two could develop over/near the mountains of southeast Arizona this afternoon and drift generally westward. However, storm organization should be limited by weaker mid-level winds, while the strongest updrafts should be relegated to south of the international border. As such, severe wind probabilities do not appear warranted. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Aug 31 2019 Valid 312000Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN KENTUCKY INTO FAR WEST-CENTRAL VIRGINIA... ...SUMMARY... A few strong storms are possible across parts of the Ohio Valley to central Appalachians this afternoon. No significant changes were made to the previous outlook. Only isolated storms are expected along the east-west instability axis from northern KY into far western VA, aided by strong heating. 18Z soundings indicate a subsidence inversion aloft, and weak shear, with only short lived, marginal wind or hail expected. ..Jewell.. 08/31/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Aug 31 2019/ ...Ohio Valley to central Appalachians... Robust boundary-layer heating near a weakly convergent quasi-stationary front, ahead of a decaying mid-level impulse, should aid in isolated thunderstorms forming by mid afternoon. A confined corridor of modest buoyancy should develop, characterized by MLCAPE of 1000-1500 J/kg. While low-level winds will be weak, a belt of 25-30 kt 500-mb southwesterlies should support transient updraft rotation in a few cells. This may yield locally strong wind gusts along with marginally severe hail. ...Northern Nebraska to southern/eastern South Dakota... While overall forcing for ascent will be limited, sufficient moist/convergence could influence isolated thunderstorm development near a weak surface/boundary across northern Nebraska/southern South Dakota. If storms develop, a severe storm or two cannot be entirely ruled out given adequate buoyancy and moderately strong northwesterly flow aloft. Storms are a bit more likely to develop later tonight across eastern South Dakota with increasing warm advection, although hail potential will tend to be limited by modest mid-level lapse rates. Overall scenario across the region currently appears too marginal/uncertain to warrant severe probabilities. ...Southern Arizona... An isolated storm or two could develop over/near the mountains of southeast Arizona this afternoon and drift generally westward. However, storm organization should be limited by weaker mid-level winds, while the strongest updrafts should be relegated to south of the international border. As such, severe wind probabilities do not appear warranted. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Aug 31 2019 Valid 312000Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN KENTUCKY INTO FAR WEST-CENTRAL VIRGINIA... ...SUMMARY... A few strong storms are possible across parts of the Ohio Valley to central Appalachians this afternoon. No significant changes were made to the previous outlook. Only isolated storms are expected along the east-west instability axis from northern KY into far western VA, aided by strong heating. 18Z soundings indicate a subsidence inversion aloft, and weak shear, with only short lived, marginal wind or hail expected. ..Jewell.. 08/31/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Aug 31 2019/ ...Ohio Valley to central Appalachians... Robust boundary-layer heating near a weakly convergent quasi-stationary front, ahead of a decaying mid-level impulse, should aid in isolated thunderstorms forming by mid afternoon. A confined corridor of modest buoyancy should develop, characterized by MLCAPE of 1000-1500 J/kg. While low-level winds will be weak, a belt of 25-30 kt 500-mb southwesterlies should support transient updraft rotation in a few cells. This may yield locally strong wind gusts along with marginally severe hail. ...Northern Nebraska to southern/eastern South Dakota... While overall forcing for ascent will be limited, sufficient moist/convergence could influence isolated thunderstorm development near a weak surface/boundary across northern Nebraska/southern South Dakota. If storms develop, a severe storm or two cannot be entirely ruled out given adequate buoyancy and moderately strong northwesterly flow aloft. Storms are a bit more likely to develop later tonight across eastern South Dakota with increasing warm advection, although hail potential will tend to be limited by modest mid-level lapse rates. Overall scenario across the region currently appears too marginal/uncertain to warrant severe probabilities. ...Southern Arizona... An isolated storm or two could develop over/near the mountains of southeast Arizona this afternoon and drift generally westward. However, storm organization should be limited by weaker mid-level winds, while the strongest updrafts should be relegated to south of the international border. As such, severe wind probabilities do not appear warranted. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0141 PM CDT Sat Aug 31 2019 Valid 011200Z - 021200Z The primary change with this forecast update was to expand the elevated fire weather area farther east across southern portions of Wyoming. While this area will be on the extreme southern periphery of the stronger mid-level flow, breezy westerly/northwesterly downslope winds amidst critically-lowered RH values and receptive fuels should foster several hours of Elevated fire weather conditions during the afternoon. While locally critically conditions are possible -- especially over the Sawtooth Mountains and Snake River plain in Idaho, the northern Wasatch Mountains in Utah, and across portions of southeast Wyoming -- the coverage of sustained wind speeds at or above 20 mph appears too limited/brief to introduce a critical fire weather area at this time. An elevated fire weather area was also considered over portions of northwest Nevada, where afternoon breeziness will overlap a large area of critical RH values (i.e., < 15%). While Vaisala National Lightning Detection Network cloud-to-ground lightning data over the past 72-hours does indicate a few flashes (and potential holdovers) occurred nearby, most of these were west of where the breezy winds are expected. Additionally, the brief/spotty nature of the threat precludes the introduction of an elevated fire weather area at this time. ..Elliott.. 08/31/2019 .PREV DISCUSSION... /ISSUED 0146 AM CDT Sat Aug 31 2019/ ...Synopsis... A vigorous mid-level shortwave trough will translate across the upper-level ridge axis over the Pacific Northwest, northern Rockies, and northern Great Basin areas on Day 2/Sunday. As a result, dry and breezy surface conditions due to the mass response associated with the passing shortwave will encourage at least a few hours of wildfire-spread potential across parts of the northwest CONUS. In addition, afternoon heating atop the higher terrain of the Rockies in central Colorado may encourage the development of a few high based storms capable of very sparse, dry lightning strikes. ...Central Rockies into the Great Basin... Widespread west-southwesterly sustained surface winds exceeding 15 mph are expected by peak afternoon heating, that in tandem with 10-20% RH, will foster conditions favorable for fire-spread through at least sunset. Fuels are quite dry across much of the Great Basin into the central Rockies. Currently, an elevated delineation is in place across parts of the Snake River Plain and surrounding locations, where aforementioned stronger flow aloft/synoptic forcing will overlap most favorably with the aforementioned elevated conditions. Widespread elevated conditions may also occur across much of the central Great Basin, but given that the strongest upper-level support will likely remain north of the area, and lack of run-to-run consistency among model guidance members, an elevated delineation will be withheld at this time. ...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 0141 PM CDT Sat Aug 31 2019 Valid 011200Z - 021200Z The primary change with this forecast update was to expand the elevated fire weather area farther east across southern portions of Wyoming. While this area will be on the extreme southern periphery of the stronger mid-level flow, breezy westerly/northwesterly downslope winds amidst critically-lowered RH values and receptive fuels should foster several hours of Elevated fire weather conditions during the afternoon. While locally critically conditions are possible -- especially over the Sawtooth Mountains and Snake River plain in Idaho, the northern Wasatch Mountains in Utah, and across portions of southeast Wyoming -- the coverage of sustained wind speeds at or above 20 mph appears too limited/brief to introduce a critical fire weather area at this time. An elevated fire weather area was also considered over portions of northwest Nevada, where afternoon breeziness will overlap a large area of critical RH values (i.e., < 15%). While Vaisala National Lightning Detection Network cloud-to-ground lightning data over the past 72-hours does indicate a few flashes (and potential holdovers) occurred nearby, most of these were west of where the breezy winds are expected. Additionally, the brief/spotty nature of the threat precludes the introduction of an elevated fire weather area at this time. ..Elliott.. 08/31/2019 .PREV DISCUSSION... /ISSUED 0146 AM CDT Sat Aug 31 2019/ ...Synopsis... A vigorous mid-level shortwave trough will translate across the upper-level ridge axis over the Pacific Northwest, northern Rockies, and northern Great Basin areas on Day 2/Sunday. As a result, dry and breezy surface conditions due to the mass response associated with the passing shortwave will encourage at least a few hours of wildfire-spread potential across parts of the northwest CONUS. In addition, afternoon heating atop the higher terrain of the Rockies in central Colorado may encourage the development of a few high based storms capable of very sparse, dry lightning strikes. ...Central Rockies into the Great Basin... Widespread west-southwesterly sustained surface winds exceeding 15 mph are expected by peak afternoon heating, that in tandem with 10-20% RH, will foster conditions favorable for fire-spread through at least sunset. Fuels are quite dry across much of the Great Basin into the central Rockies. Currently, an elevated delineation is in place across parts of the Snake River Plain and surrounding locations, where aforementioned stronger flow aloft/synoptic forcing will overlap most favorably with the aforementioned elevated conditions. Widespread elevated conditions may also occur across much of the central Great Basin, but given that the strongest upper-level support will likely remain north of the area, and lack of run-to-run consistency among model guidance members, an elevated delineation will be withheld at this time. ...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 0141 PM CDT Sat Aug 31 2019 Valid 011200Z - 021200Z The primary change with this forecast update was to expand the elevated fire weather area farther east across southern portions of Wyoming. While this area will be on the extreme southern periphery of the stronger mid-level flow, breezy westerly/northwesterly downslope winds amidst critically-lowered RH values and receptive fuels should foster several hours of Elevated fire weather conditions during the afternoon. While locally critically conditions are possible -- especially over the Sawtooth Mountains and Snake River plain in Idaho, the northern Wasatch Mountains in Utah, and across portions of southeast Wyoming -- the coverage of sustained wind speeds at or above 20 mph appears too limited/brief to introduce a critical fire weather area at this time. An elevated fire weather area was also considered over portions of northwest Nevada, where afternoon breeziness will overlap a large area of critical RH values (i.e., < 15%). While Vaisala National Lightning Detection Network cloud-to-ground lightning data over the past 72-hours does indicate a few flashes (and potential holdovers) occurred nearby, most of these were west of where the breezy winds are expected. Additionally, the brief/spotty nature of the threat precludes the introduction of an elevated fire weather area at this time. ..Elliott.. 08/31/2019 .PREV DISCUSSION... /ISSUED 0146 AM CDT Sat Aug 31 2019/ ...Synopsis... A vigorous mid-level shortwave trough will translate across the upper-level ridge axis over the Pacific Northwest, northern Rockies, and northern Great Basin areas on Day 2/Sunday. As a result, dry and breezy surface conditions due to the mass response associated with the passing shortwave will encourage at least a few hours of wildfire-spread potential across parts of the northwest CONUS. In addition, afternoon heating atop the higher terrain of the Rockies in central Colorado may encourage the development of a few high based storms capable of very sparse, dry lightning strikes. ...Central Rockies into the Great Basin... Widespread west-southwesterly sustained surface winds exceeding 15 mph are expected by peak afternoon heating, that in tandem with 10-20% RH, will foster conditions favorable for fire-spread through at least sunset. Fuels are quite dry across much of the Great Basin into the central Rockies. Currently, an elevated delineation is in place across parts of the Snake River Plain and surrounding locations, where aforementioned stronger flow aloft/synoptic forcing will overlap most favorably with the aforementioned elevated conditions. Widespread elevated conditions may also occur across much of the central Great Basin, but given that the strongest upper-level support will likely remain north of the area, and lack of run-to-run consistency among model guidance members, an elevated delineation will be withheld at this time. ...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 0141 PM CDT Sat Aug 31 2019 Valid 011200Z - 021200Z The primary change with this forecast update was to expand the elevated fire weather area farther east across southern portions of Wyoming. While this area will be on the extreme southern periphery of the stronger mid-level flow, breezy westerly/northwesterly downslope winds amidst critically-lowered RH values and receptive fuels should foster several hours of Elevated fire weather conditions during the afternoon. While locally critically conditions are possible -- especially over the Sawtooth Mountains and Snake River plain in Idaho, the northern Wasatch Mountains in Utah, and across portions of southeast Wyoming -- the coverage of sustained wind speeds at or above 20 mph appears too limited/brief to introduce a critical fire weather area at this time. An elevated fire weather area was also considered over portions of northwest Nevada, where afternoon breeziness will overlap a large area of critical RH values (i.e., < 15%). While Vaisala National Lightning Detection Network cloud-to-ground lightning data over the past 72-hours does indicate a few flashes (and potential holdovers) occurred nearby, most of these were west of where the breezy winds are expected. Additionally, the brief/spotty nature of the threat precludes the introduction of an elevated fire weather area at this time. ..Elliott.. 08/31/2019 .PREV DISCUSSION... /ISSUED 0146 AM CDT Sat Aug 31 2019/ ...Synopsis... A vigorous mid-level shortwave trough will translate across the upper-level ridge axis over the Pacific Northwest, northern Rockies, and northern Great Basin areas on Day 2/Sunday. As a result, dry and breezy surface conditions due to the mass response associated with the passing shortwave will encourage at least a few hours of wildfire-spread potential across parts of the northwest CONUS. In addition, afternoon heating atop the higher terrain of the Rockies in central Colorado may encourage the development of a few high based storms capable of very sparse, dry lightning strikes. ...Central Rockies into the Great Basin... Widespread west-southwesterly sustained surface winds exceeding 15 mph are expected by peak afternoon heating, that in tandem with 10-20% RH, will foster conditions favorable for fire-spread through at least sunset. Fuels are quite dry across much of the Great Basin into the central Rockies. Currently, an elevated delineation is in place across parts of the Snake River Plain and surrounding locations, where aforementioned stronger flow aloft/synoptic forcing will overlap most favorably with the aforementioned elevated conditions. Widespread elevated conditions may also occur across much of the central Great Basin, but given that the strongest upper-level support will likely remain north of the area, and lack of run-to-run consistency among model guidance members, an elevated delineation will be withheld at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

000
ABPZ20 KNHC 311735
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Aug 31 2019

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

Showers and thunderstorms associated with a broad area of low
pressure located several hundred miles south-southwest of the
southern coast of Mexico have become better organized since
yesterday. Environmental conditions appear conducive for further
development of this system, and a tropical depression is expected to
form during the next 2 or 3 days while the system moves west-
northwestward at 10 to 15 mph.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...90 percent.

$$
Forecaster Blake

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sat Aug 31 2019 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms on Sunday is low across the Lower 48, but a few strong storms are possible over parts of the northern High Plains, and the Ohio Valley. ...Synopsis... An upper high will remain over the Four Corners region, with ridge axis extending north across the Rockies. This ridge will break down late Sunday into Monday as a positive-tilt upper trough drops south out of British Columbia and Alberta. To the east, moderate to strong northwest flow aloft will remain over the northern Plains and toward the upper Great Lakes, with the primary upper cyclone moving from Hudson Bay into northern Quebec. Well south of the Canadian trough, cool temperatures aloft and weak height falls will sweep eastward across the OH Valley and northeastern states. At the surface, low pressure will develop from MT into the northern High Plains, with increasing southeast low-level winds resulting in warming and moistening over the region with increasing thunderstorms chances overnight from northeast MT into ND. To the east, high pressure depart New England, with gradually lowering pressure westward across the OH Valley. Here, sufficient moisture combined with cool temperatures aloft will remain to support thunderstorms, developing eastward throughout the period. Elsewhere, wind shear and the bulk of the outer convective bands associated with Hurricane Dorian is forecast to remain offshore/east of the FL coast. ...Northeast MT into ND Sunday evening and overnight... Shortwave ridging will occur over MT during the day, though strong deep-layer shear will be in place along with marginal instability. An isolated storm cannot be ruled out over northwest and north-central MT during the heat of the afternoon. Long hodographs would favor small cells, conditionally with marginal hail. The greater chance of thunderstorms will be from evening into the overnight, from northeast MT into ND, where an increasing low-level jet will aid lift. Currently, it is unclear whether elevated instability will be sufficient to support hail, but low severe probabilities cannot be ruled out in future updates. ...OH into western PA... Aside from possible ongoing rain and outflow boundaries, the surface pattern will offer little to focus storms over the OH Valley during the day. However, the presence of 60s F dewpoints beneath cool temperatures aloft along with heating will lead to scattered storms over IN and OH, then into PA and NY during the evening. A few strong wind gusts or small hail cannot be ruled out as weakly veering winds with height may support cellular activity, but in general sub-severe storms are expected. A Marginal Risk cannot be ruled out in future outlooks if instability looks to be stronger than currently expected. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Jewell.. 08/31/2019 Read more