SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0107 PM CST Wed Feb 05 2025 Valid 071200Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S., Friday through Friday night. ...Discussion... General, broad mid/upper ridging centered over the subtropical latitudes is likely to be maintained, and a prominent influence across the southern into central tier of the U.S. through this period, downstream of persistent ridging in the northern mid-latitudes, and troughing in the southern mid- to subtropic latitudes, of the eastern Pacific. To the east of the Pacific ridging, broad mean troughing, with more progressive embedded smaller scale perturbations, will linger across British Columbia and the Pacific Northwest, while developing eastward across the Canadian Prairies, northern U.S. Rockies and Great Plains. This is likely to support deepening surface troughing, and perhaps cyclogenesis, to the lee of the Rockies. However, there remains substantive spread concerning this, as models continue to struggle with their varying ability to account for the seasonably cold air now entrenched to the east of the Rockies. Some erosion, from south to north, of the shallow leading edge of this air mass is possible, beneath a continuing southerly to westerly return flow across parts of the southern Great Plains into southern Mid Atlantic. However, it appears that associated moisture emanating from a modifying western Gulf boundary layer will not become supportive of more than weak destabilization, or an appreciable risk for thunderstorms, due to negligible forcing for ascent and warm, capping layers aloft. Models do indicate that forcing for ascent and cooling mid-levels may contribute to pockets of weak destabilization across parts of the Northwest into northern Great Plains. However, based on latest forecast soundings, it remains unclear whether associated boundary-layer based and/or elevated convective development will become capable of producing more than very transient/isolated lightning. ..Kerr.. 02/05/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CST Wed Feb 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THURSDAY MORNING ACROSS PARTS OF SOUTHEASTERN KENTUCKY AND ADJACENT PORTIONS OF TENNESSEE...VIRGINIA...WEST VIRGINIA.... ...SUMMARY... Strong thunderstorms posing at least some risk for scattered potentially damaging wind gusts and perhaps small hail may impact parts of southeastern Kentucky and adjacent portions of northern Tennessee, southwestern Virginia and West Virginia early Thursday. ...Discussion... Models indicate that large-scale ridging centered over the northeastern Pacific will be maintained through this period, although it appears that an embedded mid-level high to the southeast of the Aleutians is in the process of weakening. As this proceeds, the downstream mid-level low, currently offshore of the Pacific Northwest, is also forecast to weaken, and a more significant upstream perturbation may begin to migrate inland across Oregon/northern California coastal areas by late Thursday night. Downstream, it appears that broad mid-level ridging will build across the northern Rockies and Great Plains, eastward into the lower Ohio Valley, to the north of broad ridging centered over the subtropical western Atlantic through northern Mexico, and in the wake of a significant mid-level trough accelerating across and east of the Great Lakes through Canadian Maritimes. The latter feature may be accompanied by cyclogenesis across the St. Lawrence Valley, and/or across the Canadian Maritimes by the end of the period, but models vary concerning this. However, it does appear that the leading edge of a slowly modifying surface cold intrusion to the lee of the Rockies will advance through the Mid Atlantic and south of the Ohio Valley, while remaining generally stalled across parts of the southern Great Plains. At the same time, a return flow of moisture may continue across the western Gulf Basin through the northwestern Gulf Coast/lower Mississippi Valley and middle/southern Atlantic Seaboard. Beneath relatively warm layers at mid/upper levels, potential instability is likely to remain weak, and capped, except in a corridor near the southward advancing front, from parts of the Ozark Plateau/Mid South into the Alleghenies and east of the Blue Ridge, where scattered thunderstorm development is possible Thursday into Thursday night. ...Mid South into Allegheny/Cumberland Plateau... In response to a short wave perturbation, consolidating with the larger-scale mid-level troughing progressing into/through the Great Lakes late tonight into early Thursday, lower/mid-tropospheric wind fields are forecast to undergo considerable intensification across and east-northeast of the lower Ohio Valley vicinity. It appears that this will include strengthening to 50-70+ kt within a southwesterly to westerly regime in the 850-500 mb layer, across a narrow destabilizing pre-frontal corridor across southeastern Kentucky and adjacent portions of surrounding states by 12Z Thursday. However, where large-scale ascent is able to overcome mid-level inhibition and support thunderstorm development, RAP and NAM forecast soundings exhibit mid-level lapse rates supportive of only weak CAPE, which probably will remain rooted above a saturated near- surface layer characterized by moist adiabatic to more stable lapse rates. While this is generally expected to minimize the risk for severe weather, small hail might not be out of the question in stronger storms, and it is possible that latent cooling associated with melting might enhance downdrafts sufficiently to aid the downward transfer of stronger momentum to the surface. ..Kerr.. 02/05/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1010 AM CST Wed Feb 05 2025 Valid 051630Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS PORTIONS OF THE OHIO AND TENNESSEE VALLEYS... ...SUMMARY... Thunderstorms with isolated severe potential will be possible tonight from Tennessee and Kentucky into southern Ohio and western West Virginia. ...OH/TN Valleys Tonight... A shortwave trough currently over the central Rockies will track across the Plains and into the mid MS Valley tonight. A transient low-level jet feature will accompany the shortwave and strengthen as it spreads into the OH/TN Valleys after dark. Low-level moisture will slowly increase through the day, with dewpoints in the 50s spreading northward across TN into KY. This will lead to a zone of weak CAPE (500-800 J/kg) from west TN into eastern KY. 12z Model guidance indicates the potential for one or two clusters of thunderstorms in this region during the overnight period. Forecast soundings suggest that some of the storms could become surface-based with a marginal concern for damaging wind gusts or a tornado. Mid-level lapse rates are sufficiently steep to pose some risk of hail if a robust updraft can become established. ..Hart/Jewell.. 02/05/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0922 AM CST Wed Feb 05 2025 Valid 051700Z - 061200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO... A Critical risk area has been introduced to portions of eastern New Mexico where the best fire weather potential is expected to emerge later this afternoon. Morning surface observations show a very dry air mass in place across western to central NM, characterized by dewpoints in the single digits. RH values will rapidly fall into the single digits to teens as this air mass spreads east amid strengthening westerly winds. Ongoing fog/low stratus across eastern NM and far western TX should rapidly mix out by 18 UTC as winds increase and dry air advects into the region. Latest guidance continues to suggest widespread winds between 15-20 mph are likely across eastern NM and much of the southern High Plains with a swath of 20-30 mph winds probable from east-central to northeast NM and adjacent areas of CO, KS, and the OK/TX Panhandles. Although critical wind/RH conditions may manifest across a broad swath of the southern High Plains, recent fuel guidance suggests the best overlap of receptive fuels and critical wind/RH resides across east-central NM where ERCs have increased into the 80-90th percentile in recent days. ..Moore.. 02/05/2025 .PREV DISCUSSION... /ISSUED 0200 AM CST Wed Feb 05 2025/ ...Synopsis... A shortwave trough, embedded within stronger westerly flow, will cross the Rockies and eject over the Plains through the forecast period. In response to the increase in flow aloft, a surface low will move eastward from the Great Basin and intensify in the lee of the Rockies. This will support periods of strong winds and low humidity over parts of the Southwest and High Plains. Elevated to locally critical fire-weather conditions are possible. ...High Plains and Southwest... As the upper trough crosses the Rockies, low-level westerly winds are expected to increase across central NM and parts of eastern AZ, scouring out a shallow cold air mass from a stalled cold front farther east. Aided by the increasing flow aloft, surface winds of 15-25 mph and higher gusts are likely, especially through terrain-favored areas across central NM. Ample heating/mixing should promote RH reductions into the teens to upper single digits. The combination of increasing winds with falling RH over areas of rapidly drying fuels should allow for sustained elevated to locally critical fire-weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Wed Feb 05 2025 Valid 051300Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM TENNESSEE AND KENTUCKY INTO FAR SOUTHERN OHIO AND FAR SOUTHWEST WEST VIRGINIA... ...SUMMARY... Thunderstorms with isolated severe potential will be possible this afternoon and evening from Tennessee and Kentucky into far southern Ohio and far southwest West Virginia. ...Synopsis... Early morning satellite imagery reveals a shortwave trough entering the central Plains, with another, more amplified shortwave trough farther west across the Pacific Northwest. The lead shortwave is forecast to progress eastward, reaching the Mid MS Valley by late tonight and continuing through the OH Valley early tomorrow. Mass response ahead of this wave will contribute to a broad area of moisture return, with the airmass that is currently over east TX and the Lower MS Valley advecting northeastward through the Mid South and TN Valley throughout the day. A weak surface low will likely develop over the Ozarks ahead of the approaching shortwave, before then progressing quickly northeastward along the warm front and ending the period near the OH/WV/KY border vicinity. ...Tennessee/Kentucky... As mentioned in the synopsis, moderate low-level moisture is expected to advect in the TN Valley throughout the day, with most guidance bringing low 60s dewpoints into western and south-central KY by early Thursday. Showers and occasional thunderstorms are possible amid the broad warm-air advection expected throughout the warm sector. Instability will be modest, tempered by widespread cloud cover and poor lapse rates, which is expected to limit thunderstorm strength and duration throughout much of the period. However, large-scale forcing for ascent will increase as the shortwave trough approaches the region, augmenting the ongoing warm-air advection. This increased lift is expected to result in increased convective coverage and intensity, with more persistent updrafts likely. Strong vertical shear will be in place (i.e. 0-6 km bulk shear around 50 kt), supporting the potential for organization with any more persistent updrafts. Primary threat will likely be hail as storms are generally expected to stay elevated. A strong gust or two, and perhaps even a brief tornado are possible from central KY into western/middle TN where a few surface based storms could occur. ..Mosier/Bentley.. 02/05/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Wed Feb 05 2025 Valid 051300Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM TENNESSEE AND KENTUCKY INTO FAR SOUTHERN OHIO AND FAR SOUTHWEST WEST VIRGINIA... ...SUMMARY... Thunderstorms with isolated severe potential will be possible this afternoon and evening from Tennessee and Kentucky into far southern Ohio and far southwest West Virginia. ...Synopsis... Early morning satellite imagery reveals a shortwave trough entering the central Plains, with another, more amplified shortwave trough farther west across the Pacific Northwest. The lead shortwave is forecast to progress eastward, reaching the Mid MS Valley by late tonight and continuing through the OH Valley early tomorrow. Mass response ahead of this wave will contribute to a broad area of moisture return, with the airmass that is currently over east TX and the Lower MS Valley advecting northeastward through the Mid South and TN Valley throughout the day. A weak surface low will likely develop over the Ozarks ahead of the approaching shortwave, before then progressing quickly northeastward along the warm front and ending the period near the OH/WV/KY border vicinity. ...Tennessee/Kentucky... As mentioned in the synopsis, moderate low-level moisture is expected to advect in the TN Valley throughout the day, with most guidance bringing low 60s dewpoints into western and south-central KY by early Thursday. Showers and occasional thunderstorms are possible amid the broad warm-air advection expected throughout the warm sector. Instability will be modest, tempered by widespread cloud cover and poor lapse rates, which is expected to limit thunderstorm strength and duration throughout much of the period. However, large-scale forcing for ascent will increase as the shortwave trough approaches the region, augmenting the ongoing warm-air advection. This increased lift is expected to result in increased convective coverage and intensity, with more persistent updrafts likely. Strong vertical shear will be in place (i.e. 0-6 km bulk shear around 50 kt), supporting the potential for organization with any more persistent updrafts. Primary threat will likely be hail as storms are generally expected to stay elevated. A strong gust or two, and perhaps even a brief tornado are possible from central KY into western/middle TN where a few surface based storms could occur. ..Mosier/Bentley.. 02/05/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0336 AM CST Wed Feb 05 2025 Valid 081200Z - 131200Z ...DISCUSSION... Medium-range global models appear to be in reasonable large-scale agreement into the first half of day 6 (Monday). At this point, more substantial differences begin to emerge with respect to the amplification of the flow field across the U.S., as the main western U.S. trough begins a slow eastward advance. These differences are significant in that speed and timing of the advance of this system will influence surface cyclogenesis along what has been a persistent, roughly west-to-east baroclinic zone across the south-central and southeastern CONUS. Stronger/inland low development along this front would potential bring an increase in severe-weather potential, but this scenario is far too uncertain at this point to highlight through the second half of the period. Earlier in the period, a frontal low along the surface baroclinic zone is forecast to shift out of the Oklahoma vicinity, and east-northeastward across the Ohio Valley area day 4, before reaching the southern New England coastal vicinity by the start of day 5. However, very weak warm-sector instability is expected at this time, which should preclude severe risk. As the low deepens northward into the Canadian Maritimes, the trailing cold front should settle back into its recently persistent position from the southern Plains to the Southeast, and remain there into the Day 6 period ahead of the advancing western upper trough. Again, with weak instability near the boundary and southward into the warm sector, severe weather is not expected. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0336 AM CST Wed Feb 05 2025 Valid 081200Z - 131200Z ...DISCUSSION... Medium-range global models appear to be in reasonable large-scale agreement into the first half of day 6 (Monday). At this point, more substantial differences begin to emerge with respect to the amplification of the flow field across the U.S., as the main western U.S. trough begins a slow eastward advance. These differences are significant in that speed and timing of the advance of this system will influence surface cyclogenesis along what has been a persistent, roughly west-to-east baroclinic zone across the south-central and southeastern CONUS. Stronger/inland low development along this front would potential bring an increase in severe-weather potential, but this scenario is far too uncertain at this point to highlight through the second half of the period. Earlier in the period, a frontal low along the surface baroclinic zone is forecast to shift out of the Oklahoma vicinity, and east-northeastward across the Ohio Valley area day 4, before reaching the southern New England coastal vicinity by the start of day 5. However, very weak warm-sector instability is expected at this time, which should preclude severe risk. As the low deepens northward into the Canadian Maritimes, the trailing cold front should settle back into its recently persistent position from the southern Plains to the Southeast, and remain there into the Day 6 period ahead of the advancing western upper trough. Again, with weak instability near the boundary and southward into the warm sector, severe weather is not expected. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 AM CST Wed Feb 05 2025 Valid 071200Z - 081200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunder potential appears minimal across the U.S. on Friday. ...Synopsis... Quasi-zonal flow aloft will continue across the U.S. in a broad sense on Friday. A short-wave trough initially over the northwestern U.S. will move quickly eastward within the background westerly flow field, weakening with time as it crosses the northern Rockies and reaches the northern Plains late. Surface mass response associated with this system, in the form of a weak surface low, is forecast to shift eastward across the Intermountain West and into the Plains, settling over the Nebraska vicinity late. Meanwhile, the main surface baroclinic zone will remain draped west-to-east from Oklahoma to the Southeast. Any lingering/sporadic lightning ongoing early over the Carolina Coast near this front should move quickly offshore. Afterward, though isolated showers may evolve during the afternoon near the front over the Southeast, and other/isolated showers should accompany passage of the western U.S. trough across the Rockies, any potential for lightning appears too low at this time to highlight with a 10% thunder area. ..Goss.. 02/05/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Wed Feb 05 2025 Valid 061200Z - 071200Z ...Synopsis... Continued, largely zonal, mid-level flow is expected across the central and western US D2/Thursday. Several embedded perturbations are forecast to move over the Rockies, enhancing lee troughing and surface winds over the Southwest. Continued warm/dry conditions, bolstered by increasing winds, should support several hours of elevated to near-critical fire-weather concerns. ...Southern High Plains and Southwest... Periods of breezy conditions are anticipated as low-amplitude upper disturbances and strong westerly flow aloft traverse the central Rockies. Modest lee troughing will encourage westerly downslope winds of 15-25 mph off the central/southern Rockies over much of AZ and NM. Continued dry and warm conditions, aided by deep mixing, will keep humidity below 15% over much of the area. With several days of drying, fuels will likely continue to become more receptive to fire spread. Recent model guidance has trended windier and drier across much of the Southwest. A few hours of locally critical fire-weather conditions also appear possible within areas of stronger terrain-enhanced wind gusts. However, confidence in widespread critical conditions is relatively low, given the more limited overlap of the stronger winds, low humidity and more receptive fuels. ..Lyons.. 02/05/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Wed Feb 05 2025 Valid 051200Z - 061200Z ...Synopsis... A shortwave trough, embedded within stronger westerly flow, will cross the Rockies and eject over the Plains through the forecast period. In response to the increase in flow aloft, a surface low will move eastward from the Great Basin and intensify in the lee of the Rockies. This will support periods of strong winds and low humidity over parts of the Southwest and High Plains. Elevated to locally critical fire-weather conditions are possible. ...High Plains and Southwest... As the upper trough crosses the Rockies, low-level westerly winds are expected to increase across central NM and parts of eastern AZ, scouring out a shallow cold air mass from a stalled cold front farther east. Aided by the increasing flow aloft, surface winds of 15-25 mph and higher gusts are likely, especially through terrain-favored areas across central NM. Ample heating/mixing should promote RH reductions into the teens to upper single digits. The combination of increasing winds with falling RH over areas of rapidly drying fuels should allow for sustained elevated to locally critical fire-weather conditions. ..Lyons.. 02/05/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Wed Feb 05 2025 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not expected across the U.S. on Thursday. ...Discussion... Zonal flow aloft will broadly persist across the U.S. Thursday, with the two main features being a short-wave trough pivoting toward -- and eventually into -- the Pacific Northwest, and a second that will cross Ontario/Quebec and the Great Lakes region through the period. Meanwhile, a much weaker/more subtle disturbance will move out of the Pacific and across California early, and then continue eastward across the Four Corners states, and eventually -- by the end of the period -- emerge into the Plains. At the surface, a weak frontal wave should move across the central Appalachians and then off the New England coast by evening, while the trailing cold front makes only slow southward progress across the Southeast and Southern Plains through the period. Showers and possibly a few weak thunderstorms may be ongoing at the start of the period, from the Tennessee Valley into the Mid-Atlantic region. Weak convective activity will likely continue during the period, along the aforementioned surface front as it sags southward. However, weak instability forecast across the region should substantially hinder appreciable severe risk. At this time, it appears that a stronger, elevated afternoon storm or two, evolving over the North Carolina vicinity, possibly capable of producing hail. However, overall risk for any hail exceeding 1" in diameter appears too small at this time to introduce a MRGL risk area. ..Goss.. 02/05/2025 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Wed Feb 05 2025 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not expected across the U.S. on Thursday. ...Discussion... Zonal flow aloft will broadly persist across the U.S. Thursday, with the two main features being a short-wave trough pivoting toward -- and eventually into -- the Pacific Northwest, and a second that will cross Ontario/Quebec and the Great Lakes region through the period. Meanwhile, a much weaker/more subtle disturbance will move out of the Pacific and across California early, and then continue eastward across the Four Corners states, and eventually -- by the end of the period -- emerge into the Plains. At the surface, a weak frontal wave should move across the central Appalachians and then off the New England coast by evening, while the trailing cold front makes only slow southward progress across the Southeast and Southern Plains through the period. Showers and possibly a few weak thunderstorms may be ongoing at the start of the period, from the Tennessee Valley into the Mid-Atlantic region. Weak convective activity will likely continue during the period, along the aforementioned surface front as it sags southward. However, weak instability forecast across the region should substantially hinder appreciable severe risk. At this time, it appears that a stronger, elevated afternoon storm or two, evolving over the North Carolina vicinity, possibly capable of producing hail. However, overall risk for any hail exceeding 1" in diameter appears too small at this time to introduce a MRGL risk area. ..Goss.. 02/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 PM CST Tue Feb 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TENNESSEE AND KENTUCKY... ...SUMMARY... Thunderstorms with isolated severe gusts will be possible this afternoon and evening across parts of Tennessee and Kentucky. ...Tennessee/Kentucky... A mid-level shortwave trough will move eastward across the central U.S. today, as an associated jet streak translates eastward through the central Plains. In response, a low-level jet will gradually strengthen across the Ozarks today. At the surface, a warm front will move northward across the Tennessee Valley this afternoon and into the Ohio Valley this evening. Scattered thunderstorms are expected to develop along and to the south of the warm front near the eastern edge of the low-level jet. This convection is forecast to expand in coverage as large-scale ascent increases ahead of the approaching trough. Surface dewpoints near the front should be in the 50s F, with instability remaining weak during the day due to abundant cloud cover. In spite of this, deep-layer shear will be strong, with a notable increase in shear taking place as the exit region of the mid-level jet overspreads the Ohio Valley early this evening. RAP forecast soundings near the warm front from 00Z to 02Z/Thursday across southern Kentucky and northern Tennessee have MUCAPE between 500 and 1000 J/kg, 0-6 km shear in the 50 to 60 knot range, and 700 to 500 mb lapse rates approaching 7 C/km. This environment could be enough for an isolated severe threat. If surface-based cells can initiate near or to the south of the front, a few severe gusts and a brief tornado spinup would be possible. However, a near-surface inversion is present on many of the forecast soundings along the warm front. This will likely be a negative factor for the severe threat, keeping any severe potential localized and marginal. ..Broyles/Lyons.. 02/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 PM CST Tue Feb 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TENNESSEE AND KENTUCKY... ...SUMMARY... Thunderstorms with isolated severe gusts will be possible this afternoon and evening across parts of Tennessee and Kentucky. ...Tennessee/Kentucky... A mid-level shortwave trough will move eastward across the central U.S. today, as an associated jet streak translates eastward through the central Plains. In response, a low-level jet will gradually strengthen across the Ozarks today. At the surface, a warm front will move northward across the Tennessee Valley this afternoon and into the Ohio Valley this evening. Scattered thunderstorms are expected to develop along and to the south of the warm front near the eastern edge of the low-level jet. This convection is forecast to expand in coverage as large-scale ascent increases ahead of the approaching trough. Surface dewpoints near the front should be in the 50s F, with instability remaining weak during the day due to abundant cloud cover. In spite of this, deep-layer shear will be strong, with a notable increase in shear taking place as the exit region of the mid-level jet overspreads the Ohio Valley early this evening. RAP forecast soundings near the warm front from 00Z to 02Z/Thursday across southern Kentucky and northern Tennessee have MUCAPE between 500 and 1000 J/kg, 0-6 km shear in the 50 to 60 knot range, and 700 to 500 mb lapse rates approaching 7 C/km. This environment could be enough for an isolated severe threat. If surface-based cells can initiate near or to the south of the front, a few severe gusts and a brief tornado spinup would be possible. However, a near-surface inversion is present on many of the forecast soundings along the warm front. This will likely be a negative factor for the severe threat, keeping any severe potential localized and marginal. ..Broyles/Lyons.. 02/05/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Tue Feb 04 2025 Valid 050100Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible this evening across parts of north-central California, but no severe threat is expected. ...DISCUSSION... On water vapor imagery, a ridge is located in the central U.S. with a trough near the West Coast. Ahead of the trough, an area of widespread rainfall will continue to move inland across central and northern California this evening. Large-scale ascent and steep mid-level lapse rates may be enough for isolated lightning strikes from near San Francisco eastward into the Sierras. No severe weather is expected across the continental U.S. through tonight. ..Broyles.. 02/05/2025 Read more

No watches are valid as of Tue Feb 4 22:39:02 UTC 2025.

No Mesoscale Discussions are in effect as of Tue Feb 4 22:39:02 UTC 2025.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CST Tue Feb 04 2025 Valid 061200Z - 121200Z Fire weather concerns will remain focused across the southern High Plains through the upcoming weekend. Long-range ensemble guidance continues to suggest that dry conditions will prevail across the southern High Plains for the next several days as an anomalously strong upper-level ridge over the south-central CONUS gradually breaks down. Periods of breezy conditions are anticipated as low-amplitude upper disturbances traverse the central Rockies through the late week/weekend period. Modest lee troughing will promote westerly downslope winds off the central/southern Rockies. The combination of dry air advection and downslope warming/drying will help maintain a dry air mass with daily RH minimums in the teens to low 20s. While localized elevated conditions appear possible each day during the D3/Thu through D5/Sat period, ensemble guidance suggests the strongest lee trough/cyclone will likely develop on D4/Fri afternoon across eastern CO, supporting a higher probability for achieving critical (20+ mph) winds across eastern NM and parts of western TX. A cold frontal passage on D6/Sun will usher in a cold continental air mass to much of the central/southern Plains, limiting further fire concerns heading into early next week. ..Moore.. 02/04/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0151 PM CST Tue Feb 04 2025 Valid 042000Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across northern/central California this afternoon and evening. ...Synopsis... A mid-level trough continues to approach the CA coastline, along with cooler temperatures aloft, which are poised to overspread a marginally warm and moist low-level airmass later this evening and tonight. A broad precipitation band, with embedded low-topped convection, is still expected to traverse central CA with the aforementioned cooler temperatures aloft, supporting scant buoyancy and the chance for a few lightning flashes. A couple of lightning flashes also cannot be ruled out over portions of the Intermountain West or the WA/OR coastline, as mid-level impulses pass over these regions later tonight. Even so, overall lack of buoyancy suggests that lightning flashes in these regions should remain too sparse to warrant thunder probabilities at this time. ..Squitieri.. 02/04/2025 .PREV DISCUSSION... /ISSUED 1021 AM CST Tue Feb 04 2025/ ...Northern/Central CA... Morning water vapor imagery shows a shortwave trough approaching the coast of northern CA. An associated surface cold front is also moving southeastward into northern CA, with an increasingly large shield of showers along/ahead of the front. Forecast soundings show the development of very weak CAPE later today, which could result in a few lightning flashes within the embedded precip shield. No severe storms are expected. Read more