SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1140 PM CST Mon Feb 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN SOUTHEAST TX AND SOUTH LA... ...SUMMARY... Isolated severe thunderstorms are possible this evening across parts of southeast Texas, shifting across south Louisiana tonight. Large hail should be the primary hazard, but a tornado and severe gusts will be possible along the immediate Louisiana coast. ...Southeast TX and south LA... A low-amplitude shortwave trough over the eastern Great Basin will progress east and reach the Mid-MS to Lower Red River Valley by early morning Wednesday. Weak surface cyclogenesis will occur tonight over the northwest Gulf, as a baroclinic zone strengthens in its wake with a surface ridge expanding south across the southern Great Plains. The downstream surface warm front should approach coastal LA, mainly near the mouth of the MS River, struggling to displace the modified continental air mass inland. Prior to the arrival of the Arctic air mass nosing south over the Plains, Gulf air should spread across parts of the Lower to Middle TX Coast this afternoon. To the northeast of this across southeast TX, strengthening low-level warm theta-e advection should foster elevated thunderstorms by early evening. While MUCAPE should remain weak amid moderate mid-level lapse rates, favorable speed shear within a nearly unidirectional west-southwesterly wind profile will support a threat for isolated severe hail. Elevated convection will likely consolidate into a broadening cluster in the mid to late evening across southeast TX and LA, further reinforcing the stable surface air mass inland where mid-level lapse rates will also be weaker. Overnight, organization of the cluster/short-line segments should occur near the immediate LA coast. Embedded supercell structures may brush the mouth of the MS River vicinity with an attendant tornado/severe gust threat. ..Grams/Thornton.. 02/18/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 PM CST Mon Feb 17 2025 Valid 180100Z - 181200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms should remain negligible tonight. ...Discussion... Conditions will be too dry/stable for lightning-producing convection across much of the CONUS through the period. A lone thunderstorm occurred in the past hour over western CO amid scant buoyancy and very steep lapse rates per the 00Z GJT sounding. While an additional storm or two might occur in the next hour or so, amid moderate large-scale ascent, predominately sub-freezing thermodynamic profiles with eastern extent across the CO Rockies and adjacent High Plains should largely mitigate thunderstorm potential. ..Grams.. 02/18/2025 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Mon Feb 17 2025 Valid 191200Z - 251200Z The extended forecast period will begin with a very strong Arctic high pressure in the central Plains. The associated cold front will push into the High Plains with warm and dry conditions confined to portions of the Southwest. Dry fuels remain confined to southern New Mexico and vicinity where no additional precipitation is expected this week. Therefore, by the end of the week and into the weekend when dry westerly conditions resume ahead of an approaching mid-level trough, some elevated fire weather conditions may resume. Some critical fire weather conditions may be possible, but there still remains too much uncertainty regarding the strength of winds and the timing of the trough for any probabilities at this time. ..Bentley.. 02/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Mon Feb 17 17:34:01 UTC 2025.

No Mesoscale Discussions are in effect as of Mon Feb 17 17:34:01 UTC 2025.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CST Mon Feb 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF SOUTHEASTERN TEXAS EASTWARD ACROSS SOUTHERN LOUISIANA... ...SUMMARY... A couple of strong to severe thunderstorms are expected to evolve across southeast Texas and portions of southern Louisiana, mainly Tuesday evening and into the overnight hours. ...Synopsis... A mid-/upper-level short-wave trough will continue digging southeastward across the Four Corners states during the day Tuesday, before arcing more eastward into the across the southern Plains overnight. As this system advances, weak/gradual surface wave development is expected along the primary baroclinic zone across Texas during the day. With time, as the wave shifts eastward to the Texas Coastal Plain by evening, a southward surge of Arctic air will occur in its wake. Overnight, this wave should continue eastward roughly along the western Gulf Coast, reaching the vicinity of the mouth of the Mississippi by 12Z Wednesday. By this time, the trailing cold front will likely have reached the western Gulf, with cold air penetrating south of the Rio Grande into northern Mexico. ...Southeastern Texas eastward across southern Louisiana... A broad zone of low-level theta-e advection is expected across all but western portions of the southern Plains at the start of the period, shifting gradually eastward across the Sabine and Lower Mississippi Valleys, and reaching central Gulf Coast and eventually the Southeast states overnight. As the relatively warm/moist air spreads northward atop a still-cool/stable boundary layer, elevated convection is forecast to gradually increase/expand across the eastern half of the southern Plains and into Arkansas/Louisiana through the day. By late afternoon/early evening, some convection will likely have deepened sufficiently to produce some lightning, with thunderstorm coverage then increasing and spreading eastward through the overnight hours in tandem with the advance of the aforementioned surface wave. With convection largely remaining elevated, severe potential will likely be relegated to marginal hail with a few of the strongest storms, largely evolving after sunset. Potential for near-surface-based storms will remain confined to southern portions of the MRGL risk area, where gusty winds may occur with one or two of the strongest storms. Any risk for a tornado will remain even more limited -- confined to coastal areas of southern Louisiana, and most likely after midnight. ..Goss.. 02/17/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Mon Feb 17 2025 Valid 171700Z - 181200Z No changes. See previous discussion below. ..Bentley.. 02/17/2025 .PREV DISCUSSION... /ISSUED 1158 PM CST Sun Feb 16 2025/ ...Synopsis... A disturbance will bring enhanced westerly flow today across California into the desert southwest and across the southern Rockies. This will lead to an increase in surface winds across southern Arizona into New Mexico, as well as into the southern high Plains as lee troughing strengthens and surface low development occurs. This will promote windy and dry conditions from southern Arizona into New Mexico. Across western Texas into southern New Mexico, ERCs will generally be around the 50th-75th percentile. Across southern Arizona, very little rainfall/snowfall has been observed, with ERCs also near the 75th percentile. Within these regions, overlap of relative humidity to around 15-20 percent with sustained winds around 15-20 mph (gusting locally higher) will be possible. Hi-res guidance from the HREF suggests longest duration Critical conditions would be tied to favored downslope regions near terrain features. As such, an Elevated was maintained with this outlook but locally Critical fire weather will be possible. Elevated to critical meteorological conditions will likely extend into northeastern New Mexico. However, fuels in this region are below the 50th percentile which will preclude the need to include additional Elevated or Critical areas. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1012 AM CST Mon Feb 17 2025 Valid 171630Z - 181200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A cold, continental-polar airmass is in place across the much of the Lower 48 today due to a 1045-mb surface high centered over the ND/Canada border region. Dry/cool offshore flow this morning has led to tranquil conditions across much of the Eastern Seaboard and Gulf coastlines. As a cold front pushes south across the central into the southern Great Plains, low-level flow will veer across the northwest Gulf Coast with onshore flow beginning mainly tonight. Thunderstorm potential in this region will be negated by the onset and limited duration of moisture return into the TX Gulf Coast. Cool/dry conditions will be pervasive across much of the CONUS. ..Smith/Lyons.. 02/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 AM CST Mon Feb 17 2025 Valid 171300Z - 181200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected through tonight. ...Synopsis and Discussion... A surface cold front is in the process of clearing far south FL and the Keys this morning. In its wake, expansive high pressure will dominate much of the central CONUS. Across the western states, a weak mid-level shortwave trough will advance from the Northwest towards the central Rockies through the period. With cool and/or dry conditions expected across a large majority of the CONUS, thunderstorm potential appears limited through tonight. ..Gleason/Broyles.. 02/17/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0256 AM CST Mon Feb 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... In the wake of a prior Arctic cold front moving offshore the Gulf and Atlantic coasts, strong surface high pressure will settle over a large portion of the CONUS through much of the period. This will result in a dry, stable airmass and thunderstorm potential will be low. Severe storms are not expected during the Day 4-8 period. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Mon Feb 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the Southeast on Wednesday, but severe storms are not expected. ...Synopsis... A strong, Arctic cold front will continue to surge east across the Southeast on Wednesday. Showers and thunderstorms will likely be ongoing Wednesday morning in a warm advection regime across parts of the central Gulf coast. This activity will shift east into southern GA and parts of north/central FL. While modest boundary-layer moisture will be in place ahead of the front, lapse rates will remain quite poor, limiting destabilization inland, with any substantial instability remaining over the warmer Gulf waters. While moderate vertical shear will overspread parts of the central Gulf coast and FL/GA, the poor thermodynamic environment will preclude severe thunderstorm potential. ..Leitman.. 02/17/2025 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Mon Feb 17 2025 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the Southeast on Wednesday, but severe storms are not expected. ...Synopsis... A strong, Arctic cold front will continue to surge east across the Southeast on Wednesday. Showers and thunderstorms will likely be ongoing Wednesday morning in a warm advection regime across parts of the central Gulf coast. This activity will shift east into southern GA and parts of north/central FL. While modest boundary-layer moisture will be in place ahead of the front, lapse rates will remain quite poor, limiting destabilization inland, with any substantial instability remaining over the warmer Gulf waters. While moderate vertical shear will overspread parts of the central Gulf coast and FL/GA, the poor thermodynamic environment will preclude severe thunderstorm potential. ..Leitman.. 02/17/2025 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1247 AM CST Mon Feb 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHERN LOUISIANA... ...SUMMARY... A couple of strong to severe thunderstorms are expected to evolve across southeast Texas and portions of southern Louisiana, mainly Tuesday evening and into the overnight hours. ...Upper TX Coast and Southern LA... An upper shortwave trough will move across the Plains to the MS Valley on Tuesday. This will bring a swath of enhanced mid/upper-level southwesterly flow across the south-central states. At the surface, a weak low will traverse the western Gulf Coast vicinity to southern MS through the period. Meanwhile, an Arctic cold front will surge south/southeast across the region mainly after 00z and into Wednesday morning. Ahead of the cold front, southerly near-surface flow and a strengthening southwesterly low-level jet will transport 60s F dewpoints northward. However, the northward extent of deeper moisture return will be limited to near the I-10 corridor. A cool boundary-layer beneath a warm layer between 925-850 mb will result in little surface-based instability. Additionally, nebulous large-scale ascent will preclude convective development until near 00z when the upper trough impinges on the area. Cooling aloft and modestly steep midlevel lapse rates amid moistening low/midlevels will support MUCAPE values up to around 1000 J/kg. Vertical shear will be favorable for organized convection, with elongated/straight hodographs forecast above the aforementioned warm layer. While the warm sector will be rather limited, and the cold front will quickly surge southeast after dark, a few stronger elevated storms will be possible. This activity will mainly pose a risk for marginally severe hail. There is some conditional potential toward the end of the period for near-surface based convection across parts of southern LA. However, this is conditional on the northward extent of the warm sector, which remains uncertain as the surface low is forecast to track very near the coast. If near-surface based storms can develop, some potential for strong gusts and a tornado or two will accompany storms given very favorable low-level SRH and large/curved low-level hodographs. Will include low tornado probabilities to encompass this scenario, though this outcome remains uncertain. ..Leitman.. 02/17/2025 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1247 AM CST Mon Feb 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHERN LOUISIANA... ...SUMMARY... A couple of strong to severe thunderstorms are expected to evolve across southeast Texas and portions of southern Louisiana, mainly Tuesday evening and into the overnight hours. ...Upper TX Coast and Southern LA... An upper shortwave trough will move across the Plains to the MS Valley on Tuesday. This will bring a swath of enhanced mid/upper-level southwesterly flow across the south-central states. At the surface, a weak low will traverse the western Gulf Coast vicinity to southern MS through the period. Meanwhile, an Arctic cold front will surge south/southeast across the region mainly after 00z and into Wednesday morning. Ahead of the cold front, southerly near-surface flow and a strengthening southwesterly low-level jet will transport 60s F dewpoints northward. However, the northward extent of deeper moisture return will be limited to near the I-10 corridor. A cool boundary-layer beneath a warm layer between 925-850 mb will result in little surface-based instability. Additionally, nebulous large-scale ascent will preclude convective development until near 00z when the upper trough impinges on the area. Cooling aloft and modestly steep midlevel lapse rates amid moistening low/midlevels will support MUCAPE values up to around 1000 J/kg. Vertical shear will be favorable for organized convection, with elongated/straight hodographs forecast above the aforementioned warm layer. While the warm sector will be rather limited, and the cold front will quickly surge southeast after dark, a few stronger elevated storms will be possible. This activity will mainly pose a risk for marginally severe hail. There is some conditional potential toward the end of the period for near-surface based convection across parts of southern LA. However, this is conditional on the northward extent of the warm sector, which remains uncertain as the surface low is forecast to track very near the coast. If near-surface based storms can develop, some potential for strong gusts and a tornado or two will accompany storms given very favorable low-level SRH and large/curved low-level hodographs. Will include low tornado probabilities to encompass this scenario, though this outcome remains uncertain. ..Leitman.. 02/17/2025 Read more