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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0353 PM CDT Sun Jul 21 2024 Valid 231200Z - 291200Z Fire weather concerns during the extended period will focus on parts of the Northwest, northern Great Basin, and northern Rockies. Dry and windy conditions, as well as dry thunderstorms, are possible ahead of an upper-level trough that will promote some upper-level ridge breakdown in the West. ...Wind/RH Concerns... Winds will begin to increase in the northwest into northern California as the trough approaches on Wednesday. At this time, the strongest winds appear they may remain closer to the terrain/Cascade Gaps. Winds will likely peak on Thursday across the Northwest into northern California/northwest Nevada. Critical fire weather is perhaps most likely Thursday, but there will also be some increase in RH as well. Confidence is not high enough for greater critical fire weather probabilities at this time. By Friday, strong mid-level flow will remain over parts of the northern Rockies. Additionally, a weak tropical low will rejoin the mean westerlies aloft and move into central California and the western Great Basin into the weekend. Strong winds and low RH are possible from the western Great Basin into western/central Montana on Friday and Saturday. However, there are differences between the ECMWF/GFS on the timing and intensity of some key features. When comparing the deterministic models to their counterpart ensembles, it suggests that there is large spread in potential outcomes. This uncertainty precludes introducing highlights. ...Dry Lightning... Mid-level moisture will remain across the northern Great Basin into the adjacent Northwest on Tuesday. Large-scale ascent will be weaker than on previous days and coverage is still somewhat uncertain. Available CAM and global guidance shows some potential for thunderstorms from far northern Nevada into central Idaho. Some of these storms may produce little rainfall. Thunderstorm potential for the northern Great Basin into parts of eastern Oregon, northeast California, and southwest Montana will increase on Wednesday. At least subtle forcing from an approaching trough should support some increase in storm coverage. Slightly faster storm motions should also increase the probability of a few drier storms. Mid-level moisture will shift eastward as the trough progresses. There is a consistent signal in models for thunderstorms from central Idaho into southwest and parts of central Montana. Forcing for ascent will be moderately strong as the trough moves into the region by late afternoon. Between dry sub-cloud layers and fast storm motions, confidence in dry thunderstorms is moderate to high. ..Wendt.. 07/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0558 Status Updates
STATUS FOR WATCH 0558 HAS NOT BEEN ISSUED YET Read more

WW 0558 Status Updates
STATUS FOR WATCH 0558 HAS NOT BEEN ISSUED YET Read more

No watches are valid as of Sun Jul 21 20:46:01 UTC 2024.

MD 1690 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR MOGOLLON RIM OF AZ AND ADJACENT LOWER DESERTS
Mesoscale Discussion 1690 NWS Storm Prediction Center Norman OK 0111 PM CDT Sun Jul 21 2024 Areas affected...Mogollon Rim of AZ and adjacent lower deserts Concerning...Severe potential...Watch possible Valid 211811Z - 212045Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorms will form over the Mogollon Rim through 20z and spread southward this afternoon with the potential to produce isolated outflow gusts of 60-75 mph. The need for a watch is uncertain. DISCUSSION...Visible imagery depicts deepening cumulus over the Mogollon Rim in a zone of strong surface heating, immediately downstream from a subtle midlevel perturbation over northern AZ. Continued surface heating/destabilization will contribute to MLCAPE near 1000 J/kg with minimal convective inhibition, while modest (10-20 kt) northerly midlevel flow suggests that storms and resultant cold pools will spread southward off the Rim and toward the lower deserts this afternoon. Typical inverted-V profiles with the moderate buoyancy will support precipitation-loaded downbursts capable of producing isolated outflow gusts of 60-75 mph as storms move off the higher terrain and some coalescence of storms/cold pools occurs. Isolated instances of marginally severe hail may also occur with the initial storms near the Rim. Confidence in storm formation is high, but the number of storms that will be capable of producing damaging/severe outflow gusts is less certain. Thus, the need for a severe thunderstorm watch is uncertain. ..Thompson/Smith.. 07/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...PSR...VEF... LAT...LON 32781183 33431297 34011335 34681357 35281346 35351263 34641161 34191085 34101008 33580943 33020940 32540996 32521096 32781183 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 21 2024 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL AND SOUTHERN ARIZONA... ...SUMMARY... Scattered severe thunderstorms are forecast this afternoon into the evening across parts of central and southern Arizona. Isolated severe storms are also possible from southern Colorado to eastern New Mexico. ...20Z Update... The primary change to the outlook was the introduction of a wind-driven (15 percent) Slight Risk over portions of central and southern Arizona. Thunderstorms are increasing in coverage along the Mogollon Rim early this afternoon, and with the approach of a subtle midlevel wave, this trend should continue. These recent convective trends have increased confidence in a sufficient amount of storms (and related congealing outflow) spreading southward off the Rim -- with a risk of scattered severe gusts into this evening. For additional details, reference MCD #1690. ..Weinman/Smith.. 07/21/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Jul 21 2024/ ...Synopsis... Water-vapor imagery late this morning shows a mid-level disturbance moving south-southeast across WY/CO to the east of a mid-level ridge located over the Interior West. A mid-level shortwave trough will move northward along the Pacific Northwest coast into British Columbia by tonight. Farther east, a mid-level trough/low centered over the lower MO/mid MS Valleys will meander slowly eastward. ...Sangre de Cristos and adjacent escarpment/plains... Scattered orographically favored thunderstorm development is forecast by early to mid afternoon across the mountains ahead of the aforementioned weak upper disturbance. A seasonably moist airmass (reference 12 UTC Albuquerque raob data) is in place across the region with considerable cloud breaks and partly sunny skies noted in visible-satellite imagery. Strong heating will foster upwards of 500-1250 J/kg MLCAPE by peak heating. Modest deep-layer shear will limit overall convective organization potential, but the stronger multicells (becoming numerous in coverage) will likely be capable of an isolated hail/wind risk through the early evening before this activity dissipates. ...AZ... A weak PV anomaly was noted in upper-layer water-vapor imagery this morning over northern AZ. This upper feature may aid in storm development near the Mogollon Rim later this afternoon with scattered thunderstorms forecast. A hot and a deeply mixed sub-cloud layer in the lower desert will likely support some risk for severe gusts via evaporatively cooled downbursts as this activity slowly pushes southward late this afternoon through the evening. Isolated to widely scattered severe gusts (60-75 mph) are possible with the stronger cores and outflow surges. ...Central/eastern Oregon into northwest NV... Model guidance indicates scattered thunderstorms are forecast to develop later this afternoon on the southeast periphery of the mid-level shortwave trough glancing the region. Inverted-V profiles per forecast soundings suggest gusty winds may accompany the stronger downdrafts. The overall severe risk appears too limited in time/space to include a 5-percent severe wind highlight. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 PM CDT Sun Jul 21 2024 Valid 221200Z - 231200Z Slight expansion to the isolated dry thunder area was made in parts of eastern/northern Washington. CAM guidance and forecast soundings show potential for storms during the afternoon in these areas. Some lightning activity is possible very early in the period in the Columbia Basin, but confidence in coverage is not particularly high. ..Wendt.. 07/21/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sun Jul 21 2024/ ...Synopsis... A broad upper trough over the Pacific Northwest is forecast to intensify as it merges with a second trough moving onshore from the eastern Pacific. Stronger flow aloft ahead of the trough will move inland, increasing mid-level moisture to the west of a weakening mid-level ridge. Thunderstorms are likely ahead of the trough over parts of the northern Rockies and Northwest, with dry fuels and little rainfall supporting a risk for dry lightning ignitions. ...Northwest, and Northern Rockies... Isolated dry thunderstorms are expected to be ongoing early in the period as convection from the previous day continues to advect north with the advancing upper trough. Additional storm development is possible later in the afternoon, as peak diurnal heating and lingering mid-level moisture allow for weak buoyancy. Deep and well-mixed sub-cloud layers, along with moderate storm speeds, will favor low precipitation efficiency and the potential for dry lightning strikes with any storm that develops. Scattered thunderstorm are also possible farther south across parts of the Great Basin, but a wetter mode is more probable. Coverage of dry storms appears highest across parts of south-central OR, extending northeastward across central ID into western MT. With receptive fuels in place over much of the Northwest and northern Rockies, IsoDryT probabilities are warranted. ...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 0159 PM CDT Sun Jul 21 2024 Valid 221200Z - 231200Z Slight expansion to the isolated dry thunder area was made in parts of eastern/northern Washington. CAM guidance and forecast soundings show potential for storms during the afternoon in these areas. Some lightning activity is possible very early in the period in the Columbia Basin, but confidence in coverage is not particularly high. ..Wendt.. 07/21/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sun Jul 21 2024/ ...Synopsis... A broad upper trough over the Pacific Northwest is forecast to intensify as it merges with a second trough moving onshore from the eastern Pacific. Stronger flow aloft ahead of the trough will move inland, increasing mid-level moisture to the west of a weakening mid-level ridge. Thunderstorms are likely ahead of the trough over parts of the northern Rockies and Northwest, with dry fuels and little rainfall supporting a risk for dry lightning ignitions. ...Northwest, and Northern Rockies... Isolated dry thunderstorms are expected to be ongoing early in the period as convection from the previous day continues to advect north with the advancing upper trough. Additional storm development is possible later in the afternoon, as peak diurnal heating and lingering mid-level moisture allow for weak buoyancy. Deep and well-mixed sub-cloud layers, along with moderate storm speeds, will favor low precipitation efficiency and the potential for dry lightning strikes with any storm that develops. Scattered thunderstorm are also possible farther south across parts of the Great Basin, but a wetter mode is more probable. Coverage of dry storms appears highest across parts of south-central OR, extending northeastward across central ID into western MT. With receptive fuels in place over much of the Northwest and northern Rockies, IsoDryT probabilities are warranted. ...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 0159 PM CDT Sun Jul 21 2024 Valid 221200Z - 231200Z Slight expansion to the isolated dry thunder area was made in parts of eastern/northern Washington. CAM guidance and forecast soundings show potential for storms during the afternoon in these areas. Some lightning activity is possible very early in the period in the Columbia Basin, but confidence in coverage is not particularly high. ..Wendt.. 07/21/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sun Jul 21 2024/ ...Synopsis... A broad upper trough over the Pacific Northwest is forecast to intensify as it merges with a second trough moving onshore from the eastern Pacific. Stronger flow aloft ahead of the trough will move inland, increasing mid-level moisture to the west of a weakening mid-level ridge. Thunderstorms are likely ahead of the trough over parts of the northern Rockies and Northwest, with dry fuels and little rainfall supporting a risk for dry lightning ignitions. ...Northwest, and Northern Rockies... Isolated dry thunderstorms are expected to be ongoing early in the period as convection from the previous day continues to advect north with the advancing upper trough. Additional storm development is possible later in the afternoon, as peak diurnal heating and lingering mid-level moisture allow for weak buoyancy. Deep and well-mixed sub-cloud layers, along with moderate storm speeds, will favor low precipitation efficiency and the potential for dry lightning strikes with any storm that develops. Scattered thunderstorm are also possible farther south across parts of the Great Basin, but a wetter mode is more probable. Coverage of dry storms appears highest across parts of south-central OR, extending northeastward across central ID into western MT. With receptive fuels in place over much of the Northwest and northern Rockies, IsoDryT probabilities are warranted. ...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 0159 PM CDT Sun Jul 21 2024 Valid 221200Z - 231200Z Slight expansion to the isolated dry thunder area was made in parts of eastern/northern Washington. CAM guidance and forecast soundings show potential for storms during the afternoon in these areas. Some lightning activity is possible very early in the period in the Columbia Basin, but confidence in coverage is not particularly high. ..Wendt.. 07/21/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sun Jul 21 2024/ ...Synopsis... A broad upper trough over the Pacific Northwest is forecast to intensify as it merges with a second trough moving onshore from the eastern Pacific. Stronger flow aloft ahead of the trough will move inland, increasing mid-level moisture to the west of a weakening mid-level ridge. Thunderstorms are likely ahead of the trough over parts of the northern Rockies and Northwest, with dry fuels and little rainfall supporting a risk for dry lightning ignitions. ...Northwest, and Northern Rockies... Isolated dry thunderstorms are expected to be ongoing early in the period as convection from the previous day continues to advect north with the advancing upper trough. Additional storm development is possible later in the afternoon, as peak diurnal heating and lingering mid-level moisture allow for weak buoyancy. Deep and well-mixed sub-cloud layers, along with moderate storm speeds, will favor low precipitation efficiency and the potential for dry lightning strikes with any storm that develops. Scattered thunderstorm are also possible farther south across parts of the Great Basin, but a wetter mode is more probable. Coverage of dry storms appears highest across parts of south-central OR, extending northeastward across central ID into western MT. With receptive fuels in place over much of the Northwest and northern Rockies, IsoDryT probabilities are warranted. ...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 0159 PM CDT Sun Jul 21 2024 Valid 221200Z - 231200Z Slight expansion to the isolated dry thunder area was made in parts of eastern/northern Washington. CAM guidance and forecast soundings show potential for storms during the afternoon in these areas. Some lightning activity is possible very early in the period in the Columbia Basin, but confidence in coverage is not particularly high. ..Wendt.. 07/21/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sun Jul 21 2024/ ...Synopsis... A broad upper trough over the Pacific Northwest is forecast to intensify as it merges with a second trough moving onshore from the eastern Pacific. Stronger flow aloft ahead of the trough will move inland, increasing mid-level moisture to the west of a weakening mid-level ridge. Thunderstorms are likely ahead of the trough over parts of the northern Rockies and Northwest, with dry fuels and little rainfall supporting a risk for dry lightning ignitions. ...Northwest, and Northern Rockies... Isolated dry thunderstorms are expected to be ongoing early in the period as convection from the previous day continues to advect north with the advancing upper trough. Additional storm development is possible later in the afternoon, as peak diurnal heating and lingering mid-level moisture allow for weak buoyancy. Deep and well-mixed sub-cloud layers, along with moderate storm speeds, will favor low precipitation efficiency and the potential for dry lightning strikes with any storm that develops. Scattered thunderstorm are also possible farther south across parts of the Great Basin, but a wetter mode is more probable. Coverage of dry storms appears highest across parts of south-central OR, extending northeastward across central ID into western MT. With receptive fuels in place over much of the Northwest and northern Rockies, IsoDryT probabilities are warranted. ...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 0159 PM CDT Sun Jul 21 2024 Valid 221200Z - 231200Z Slight expansion to the isolated dry thunder area was made in parts of eastern/northern Washington. CAM guidance and forecast soundings show potential for storms during the afternoon in these areas. Some lightning activity is possible very early in the period in the Columbia Basin, but confidence in coverage is not particularly high. ..Wendt.. 07/21/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sun Jul 21 2024/ ...Synopsis... A broad upper trough over the Pacific Northwest is forecast to intensify as it merges with a second trough moving onshore from the eastern Pacific. Stronger flow aloft ahead of the trough will move inland, increasing mid-level moisture to the west of a weakening mid-level ridge. Thunderstorms are likely ahead of the trough over parts of the northern Rockies and Northwest, with dry fuels and little rainfall supporting a risk for dry lightning ignitions. ...Northwest, and Northern Rockies... Isolated dry thunderstorms are expected to be ongoing early in the period as convection from the previous day continues to advect north with the advancing upper trough. Additional storm development is possible later in the afternoon, as peak diurnal heating and lingering mid-level moisture allow for weak buoyancy. Deep and well-mixed sub-cloud layers, along with moderate storm speeds, will favor low precipitation efficiency and the potential for dry lightning strikes with any storm that develops. Scattered thunderstorm are also possible farther south across parts of the Great Basin, but a wetter mode is more probable. Coverage of dry storms appears highest across parts of south-central OR, extending northeastward across central ID into western MT. With receptive fuels in place over much of the Northwest and northern Rockies, IsoDryT probabilities are warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more