Here you'll find all available severe weather outlooks on one page.
Isolated non-severe thunderstorms are possible across the Lower Colorado Valley and southern Arizona through tonight.
← back to overviewSPC AC 201940
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0140 PM CST Wed Jan 20 2021
Valid 202000Z - 211200Z
NO SEVERE THUNDERSTORM AREAS FORECAST
### SUMMARY
Isolated non-severe thunderstorms are possible across the Lower Colorado Valley and southern Arizona through tonight.
20z Update
The ongoing forecast remains on track, and no changes are necessary with this update. For forecast details, please see the previous discussion below.
..Leitman.. 01/20/2021
.PREV DISCUSSION… /ISSUED 1029 AM CST Wed Jan 20 2021/
Southern Arizona/far southeast California
A closed upper low west of the Baja Peninsula will become somewhat more progressive as it evolves into an open wave through early Thursday morning while approaching the northern Gulf of California. Preceding it, a plume of sufficient low to mid-level moisture across the peninsula and gulf will support periods of showers and embedded thunderstorms mostly across the northwest portions of Mexico and adjacent waters. Some of this activity will spread across the international border, mainly later this afternoon through tonight across southern Arizona. Severe thunderstorms are unlikely owing to meager buoyancy and weak low-level winds.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
Severe weather is not expected across the U.S. on Thursday.
← back to overviewSPC AC 201712
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CST Wed Jan 20 2021
Valid 211200Z - 221200Z
NO SEVERE THUNDERSTORM AREAS FORECAST
### SUMMARY
Severe weather is not expected across the U.S. on Thursday.
Synopsis
The upper low over the lower Colorado River Valley/northwest Mexico will weaken and become an open wave as it progresses east/northeast across New Mexico, and moves into the southern Plains overnight. Cooling temperatures aloft near the compact low/shortwave trough will result in steep midlevel lapse rates and enough instability to support isolated lightning flashes near the Colorado Valley and into southern AZ.
Further east, a southern and northern stream jet over the TN Valley/southern states and the Midwest will merge as a broad trough envelopes the eastern half of the country. Modest cooling aloft as the upper southwestern upper trough approaches during the evening and nighttime hours will allow for modest instability across portions of north TX into the lower MS Valley. A few lightning flashes could accompany showers during the later half of the forecast period.
..Leitman.. 01/20/2021
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z
No severe weather is expected across the U.S. Friday.
← back to overviewSPC AC 200707
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0107 AM CST Wed Jan 20 2021
Valid 221200Z - 231200Z
NO THUNDERSTORM AREAS FORECAST
### SUMMARY
No severe weather is expected across the U.S. Friday.
Discussion
Substantial amplification of the large-scale pattern is expected Friday, as the short-wave trough digging southeastward across the northwestern U.S. at the start of the period strengthens with time. By the end of the period, broad/high-amplitude cyclonic flow will prevail over the entire western U.S., with the positively tilted trough axis extending from Montana to central California.
At the surface, high pressure will prevail east of the Rockies through the period, while a cold front shifts across the Southwest/southern Rockies through the period.
With dry/stable conditions prevailing east of the Rockies, thunderstorms are not expected. In the West, cold air/steep lapse rates aloft – associated with the upper trough – will support scattered/showery convection. While a lightning flash or two cannot be ruled out, any coverage would likely be less than 10%.
..Goss.. 01/20/2021
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z
You are looking at an outlook that is part of the medium range forecast (the outlook for days 4-8). The most important thing to note is that lack of a risk does not mean zero risk. Generally speaking, confidence has to be pretty high for the Storm Prediction Center to have an outlook area this far into the future.
If you bookmark this page, it will continue to update with each new outlook that is issued.
← back to overviewZCZC SPCSWOD48 ALL ACUS48 KWNS 200930 SPC AC 200930
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CST Wed Jan 20 2021
Valid 231200Z - 281200Z
DISCUSSION
Medium-range models are in reasonably good agreement with respect to the synoptic-scale features across the U.S. through roughly Day 5 (Sunday). Beyond that, increasing divergence in solutions suggests insufficient predictability to make any meaningful assessment of convective potential.
Within the Day 4-5 time frame, the primary feature of interest will be the large trough situated over the West at the start of the period. More specifically, a short-wave feature moving through the broader-scale cyclonic flow – which is progged to lie near the central California coast at the start of Day 4 – will substantially influence convective potential in the medium range.
Day 4 (Saturday), this short-wave feature is forecast to shift southeastward, moving into the southwestern U.S./northern Baja during the overnight hours. As this occurs, an increase in southerly low-level flow is progged over the southern Plains. This trend will continue into Day 5, as the upper system shifts eastward and crosses northern Mexico/Arizona/New Mexico – but while weakening steadily as it progresses eastward. In response, rather ill-defined cyclogenesis is expected to occur over the Texas vicinity. As ascent increases and low-level moisture advection continues, an increase in convective potential will occur across the southern Plains and into the lower Mississippi Valley. However, despite favorable shear that would otherwise support severe potential, some likelihood for persistent/weak boundary layer stability beneath low-level capping is a concern. Still, some severe potential could evolve, possibly focused along a weak east-to-west warm frontal zone across east Texas and the Arklatex region later Sunday and into Monday. However, degree of risk remains questionable at this time, such that an outlook area will not be introduced at this time.
By Day 6 (Monday), the weakening upper system is progged by the GFS to essentially dampen out with time, as it crosses Oklahoma and Kansas, and shifts into Missouri. Meanwhile, the ECMWF maintains a much more well-defined feature, that moves quickly across the Ozarks and Mid Mississippi Valley by evening, and then into/across the Carolinas and Virginia by the end of the period. Along with this more pronounced upper feature, a corresponding/well-developed surface cyclone is also progged to cross the southeastern quarter of the country Monday, suggestive of at least some severe potential spreading eastward across this region should the pattern evolve more similar to the ECMWF solution.
At this time however, given the increasing model differences beyond Day 5/Sunday, no severe-weather assessment will be attempted through the remainder of the medium-range period.
..Goss.. 01/20/2021
CLICK TO GET WUUS48 PTSD48 PRODUCT
You are looking at an outlook that is part of the medium range forecast (the outlook for days 4-8). The most important thing to note is that lack of a risk does not mean zero risk. Generally speaking, confidence has to be pretty high for the Storm Prediction Center to have an outlook area this far into the future.
If you bookmark this page, it will continue to update with each new outlook that is issued.
← back to overviewZCZC SPCSWOD48 ALL ACUS48 KWNS 200930 SPC AC 200930
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CST Wed Jan 20 2021
Valid 231200Z - 281200Z
DISCUSSION
Medium-range models are in reasonably good agreement with respect to the synoptic-scale features across the U.S. through roughly Day 5 (Sunday). Beyond that, increasing divergence in solutions suggests insufficient predictability to make any meaningful assessment of convective potential.
Within the Day 4-5 time frame, the primary feature of interest will be the large trough situated over the West at the start of the period. More specifically, a short-wave feature moving through the broader-scale cyclonic flow – which is progged to lie near the central California coast at the start of Day 4 – will substantially influence convective potential in the medium range.
Day 4 (Saturday), this short-wave feature is forecast to shift southeastward, moving into the southwestern U.S./northern Baja during the overnight hours. As this occurs, an increase in southerly low-level flow is progged over the southern Plains. This trend will continue into Day 5, as the upper system shifts eastward and crosses northern Mexico/Arizona/New Mexico – but while weakening steadily as it progresses eastward. In response, rather ill-defined cyclogenesis is expected to occur over the Texas vicinity. As ascent increases and low-level moisture advection continues, an increase in convective potential will occur across the southern Plains and into the lower Mississippi Valley. However, despite favorable shear that would otherwise support severe potential, some likelihood for persistent/weak boundary layer stability beneath low-level capping is a concern. Still, some severe potential could evolve, possibly focused along a weak east-to-west warm frontal zone across east Texas and the Arklatex region later Sunday and into Monday. However, degree of risk remains questionable at this time, such that an outlook area will not be introduced at this time.
By Day 6 (Monday), the weakening upper system is progged by the GFS to essentially dampen out with time, as it crosses Oklahoma and Kansas, and shifts into Missouri. Meanwhile, the ECMWF maintains a much more well-defined feature, that moves quickly across the Ozarks and Mid Mississippi Valley by evening, and then into/across the Carolinas and Virginia by the end of the period. Along with this more pronounced upper feature, a corresponding/well-developed surface cyclone is also progged to cross the southeastern quarter of the country Monday, suggestive of at least some severe potential spreading eastward across this region should the pattern evolve more similar to the ECMWF solution.
At this time however, given the increasing model differences beyond Day 5/Sunday, no severe-weather assessment will be attempted through the remainder of the medium-range period.
..Goss.. 01/20/2021
CLICK TO GET WUUS48 PTSD48 PRODUCT
You are looking at an outlook that is part of the medium range forecast (the outlook for days 4-8). The most important thing to note is that lack of a risk does not mean zero risk. Generally speaking, confidence has to be pretty high for the Storm Prediction Center to have an outlook area this far into the future.
If you bookmark this page, it will continue to update with each new outlook that is issued.
← back to overviewZCZC SPCSWOD48 ALL ACUS48 KWNS 200930 SPC AC 200930
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CST Wed Jan 20 2021
Valid 231200Z - 281200Z
DISCUSSION
Medium-range models are in reasonably good agreement with respect to the synoptic-scale features across the U.S. through roughly Day 5 (Sunday). Beyond that, increasing divergence in solutions suggests insufficient predictability to make any meaningful assessment of convective potential.
Within the Day 4-5 time frame, the primary feature of interest will be the large trough situated over the West at the start of the period. More specifically, a short-wave feature moving through the broader-scale cyclonic flow – which is progged to lie near the central California coast at the start of Day 4 – will substantially influence convective potential in the medium range.
Day 4 (Saturday), this short-wave feature is forecast to shift southeastward, moving into the southwestern U.S./northern Baja during the overnight hours. As this occurs, an increase in southerly low-level flow is progged over the southern Plains. This trend will continue into Day 5, as the upper system shifts eastward and crosses northern Mexico/Arizona/New Mexico – but while weakening steadily as it progresses eastward. In response, rather ill-defined cyclogenesis is expected to occur over the Texas vicinity. As ascent increases and low-level moisture advection continues, an increase in convective potential will occur across the southern Plains and into the lower Mississippi Valley. However, despite favorable shear that would otherwise support severe potential, some likelihood for persistent/weak boundary layer stability beneath low-level capping is a concern. Still, some severe potential could evolve, possibly focused along a weak east-to-west warm frontal zone across east Texas and the Arklatex region later Sunday and into Monday. However, degree of risk remains questionable at this time, such that an outlook area will not be introduced at this time.
By Day 6 (Monday), the weakening upper system is progged by the GFS to essentially dampen out with time, as it crosses Oklahoma and Kansas, and shifts into Missouri. Meanwhile, the ECMWF maintains a much more well-defined feature, that moves quickly across the Ozarks and Mid Mississippi Valley by evening, and then into/across the Carolinas and Virginia by the end of the period. Along with this more pronounced upper feature, a corresponding/well-developed surface cyclone is also progged to cross the southeastern quarter of the country Monday, suggestive of at least some severe potential spreading eastward across this region should the pattern evolve more similar to the ECMWF solution.
At this time however, given the increasing model differences beyond Day 5/Sunday, no severe-weather assessment will be attempted through the remainder of the medium-range period.
..Goss.. 01/20/2021
CLICK TO GET WUUS48 PTSD48 PRODUCT
You are looking at an outlook that is part of the medium range forecast (the outlook for days 4-8). The most important thing to note is that lack of a risk does not mean zero risk. Generally speaking, confidence has to be pretty high for the Storm Prediction Center to have an outlook area this far into the future.
If you bookmark this page, it will continue to update with each new outlook that is issued.
← back to overviewZCZC SPCSWOD48 ALL ACUS48 KWNS 200930 SPC AC 200930
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CST Wed Jan 20 2021
Valid 231200Z - 281200Z
DISCUSSION
Medium-range models are in reasonably good agreement with respect to the synoptic-scale features across the U.S. through roughly Day 5 (Sunday). Beyond that, increasing divergence in solutions suggests insufficient predictability to make any meaningful assessment of convective potential.
Within the Day 4-5 time frame, the primary feature of interest will be the large trough situated over the West at the start of the period. More specifically, a short-wave feature moving through the broader-scale cyclonic flow – which is progged to lie near the central California coast at the start of Day 4 – will substantially influence convective potential in the medium range.
Day 4 (Saturday), this short-wave feature is forecast to shift southeastward, moving into the southwestern U.S./northern Baja during the overnight hours. As this occurs, an increase in southerly low-level flow is progged over the southern Plains. This trend will continue into Day 5, as the upper system shifts eastward and crosses northern Mexico/Arizona/New Mexico – but while weakening steadily as it progresses eastward. In response, rather ill-defined cyclogenesis is expected to occur over the Texas vicinity. As ascent increases and low-level moisture advection continues, an increase in convective potential will occur across the southern Plains and into the lower Mississippi Valley. However, despite favorable shear that would otherwise support severe potential, some likelihood for persistent/weak boundary layer stability beneath low-level capping is a concern. Still, some severe potential could evolve, possibly focused along a weak east-to-west warm frontal zone across east Texas and the Arklatex region later Sunday and into Monday. However, degree of risk remains questionable at this time, such that an outlook area will not be introduced at this time.
By Day 6 (Monday), the weakening upper system is progged by the GFS to essentially dampen out with time, as it crosses Oklahoma and Kansas, and shifts into Missouri. Meanwhile, the ECMWF maintains a much more well-defined feature, that moves quickly across the Ozarks and Mid Mississippi Valley by evening, and then into/across the Carolinas and Virginia by the end of the period. Along with this more pronounced upper feature, a corresponding/well-developed surface cyclone is also progged to cross the southeastern quarter of the country Monday, suggestive of at least some severe potential spreading eastward across this region should the pattern evolve more similar to the ECMWF solution.
At this time however, given the increasing model differences beyond Day 5/Sunday, no severe-weather assessment will be attempted through the remainder of the medium-range period.
..Goss.. 01/20/2021
CLICK TO GET WUUS48 PTSD48 PRODUCT
You are looking at an outlook that is part of the medium range forecast (the outlook for days 4-8). The most important thing to note is that lack of a risk does not mean zero risk. Generally speaking, confidence has to be pretty high for the Storm Prediction Center to have an outlook area this far into the future.
If you bookmark this page, it will continue to update with each new outlook that is issued.
← back to overviewZCZC SPCSWOD48 ALL ACUS48 KWNS 200930 SPC AC 200930
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CST Wed Jan 20 2021
Valid 231200Z - 281200Z
DISCUSSION
Medium-range models are in reasonably good agreement with respect to the synoptic-scale features across the U.S. through roughly Day 5 (Sunday). Beyond that, increasing divergence in solutions suggests insufficient predictability to make any meaningful assessment of convective potential.
Within the Day 4-5 time frame, the primary feature of interest will be the large trough situated over the West at the start of the period. More specifically, a short-wave feature moving through the broader-scale cyclonic flow – which is progged to lie near the central California coast at the start of Day 4 – will substantially influence convective potential in the medium range.
Day 4 (Saturday), this short-wave feature is forecast to shift southeastward, moving into the southwestern U.S./northern Baja during the overnight hours. As this occurs, an increase in southerly low-level flow is progged over the southern Plains. This trend will continue into Day 5, as the upper system shifts eastward and crosses northern Mexico/Arizona/New Mexico – but while weakening steadily as it progresses eastward. In response, rather ill-defined cyclogenesis is expected to occur over the Texas vicinity. As ascent increases and low-level moisture advection continues, an increase in convective potential will occur across the southern Plains and into the lower Mississippi Valley. However, despite favorable shear that would otherwise support severe potential, some likelihood for persistent/weak boundary layer stability beneath low-level capping is a concern. Still, some severe potential could evolve, possibly focused along a weak east-to-west warm frontal zone across east Texas and the Arklatex region later Sunday and into Monday. However, degree of risk remains questionable at this time, such that an outlook area will not be introduced at this time.
By Day 6 (Monday), the weakening upper system is progged by the GFS to essentially dampen out with time, as it crosses Oklahoma and Kansas, and shifts into Missouri. Meanwhile, the ECMWF maintains a much more well-defined feature, that moves quickly across the Ozarks and Mid Mississippi Valley by evening, and then into/across the Carolinas and Virginia by the end of the period. Along with this more pronounced upper feature, a corresponding/well-developed surface cyclone is also progged to cross the southeastern quarter of the country Monday, suggestive of at least some severe potential spreading eastward across this region should the pattern evolve more similar to the ECMWF solution.
At this time however, given the increasing model differences beyond Day 5/Sunday, no severe-weather assessment will be attempted through the remainder of the medium-range period.
..Goss.. 01/20/2021
CLICK TO GET WUUS48 PTSD48 PRODUCT
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