Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1054 AM CST Thu Nov 10 2022 Valid 101700Z - 111200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 11/10/2022 .PREV DISCUSSION... /ISSUED 1237 AM CST Thu Nov 10 2022/ ...Synopsis... A cold front will move southeastward across the central US early Thursday. Dry post-frontal northwesterly flow will overspread the Plains by Thursday afternoon with relative humidity falling to around 20-25 percent across western Kansas south into the Oklahoma Panhandle. Though conditions will be dry and windy, much cooler temperatures and recent rainfall will keep fire weather concerns low. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1935 CONCERNING WINTER MIXED PRECIPITATION FOR EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA.
Mesoscale Discussion 1935 NWS Storm Prediction Center Norman OK 1038 AM CST Thu Nov 10 2022 Areas affected...eastern North Dakota into northern Minnesota. Concerning...Winter mixed precipitation Valid 101638Z - 102045Z SUMMARY...Areas of mixed sleet and freezing rain should expand in coverage near a strengthening low this morning/early afternoon. DISCUSSION...As of 1620 UTC, upper air and objective analysis showed a deep upper trough and associated surface low across south MN, with a warm front extending northeastward toward the international border. To the north of the front, weak convection within the waa regime has supported some mixed precipitation including snow pellets and freezing drizzle over the last 2 hours. As lift and warm advection increase ahead of the approaching upper trough, additional precip should develop atop the shallow cold airmass north of the front from southeastern ND into north-central MN. Area RAP soundings show temperatures in the elevated warm nose near or slightly above freezing suggesting sleet and some freezing rain are likely to develop. Rates may briefly approach 0.25 inches per hour with weak embedded convective elements and some elevated instability (MUCAPE ~100 J/kg). A transition to all snow (heavy at times) appears likely later this afternoon and evening as the surface low and upper wave shift northeastward, weakening the warm nose and deepening the freezing layer. ..Lyons.. 11/10/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...FGF... LAT...LON 46549775 47489738 47949665 48389571 48629497 48789393 48609239 48449231 47889318 47059539 46769627 46489737 46549775 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Thu Nov 10 2022 Valid 101630Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT OVER PARTS OF NORTHEAST FLORIDA...EASTERN GEORGIA...AND THE COASTAL CAROLINAS... ...SUMMARY... A few tornadoes are possible today from northern Florida into eastern Georgia and South Carolina, and possibly overnight into southern North Carolina. Isolated damaging gusts are possible this afternoon across parts of the Upper Mississippi to Lower Missouri Valleys. ...FL/GA/Carolinas... Tropical Storm Nicole continues to affect much of FL. So far, convection over the eastern semi-circle has not shown significant intensity, with only occasional and transient rotating structures off of the coast near JAX. This is near a surface baroclinic zone that extends northeastward just off the GA/SC/NC coast. Most model solutions suggest this boundary will drift inland this afternoon, resulting in at least a conditional risk of surface-based deep convection. Shear profiles will be quite strong throughout this area, possibly resulting in a few tornadoes this afternoon and tonight if convective trends increase. The threat farther inland will be limited by northeasterly surface winds, dewpoints only in the 60s, and dense cloud cover maintaining a generally stable surface airmass. ...Upper MS Valley... A very strong surface cold front is sweeping eastward across parts of MN/IA/KS, and will affect much of the upper MS Valley through the day. Dewpoints in the 60s and partial daytime heating will lead to sufficient CAPE (generally around 750 J/kg) ahead of the front for a line of showers and low-topped thunderstorms by mid-afternoon. Wind fields and forcing are strong, suggesting a risk of gusty/damaging winds in the more robust cells along the line. Morning CAM solutions differ on the extent/intensity of the convective line, and given the weak CAPE, there is doubt whether the line can become sufficiently organized to pose an organized damaging wind threat. Therefore will maintain MRGL risk. However, an upgrade to SLGT is possible later today if mesoscale trends show the line strengthening more than anticipated. ..Hart/Lyons.. 11/10/2022 Read more

WW 0565 Status Updates
STATUS REPORT ON WW 565 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ENE SGJ TO 20 SE JAX TO 25 SW JAX. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1934 ..SQUITIERI..11/10/22 ATTN...WFO...JAX... STATUS REPORT FOR WT 565 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC031-089-101640- FL . FLORIDA COUNTIES INCLUDED ARE DUVAL NASSAU GAC039-127-101640- GA . GEORGIA COUNTIES INCLUDED ARE CAMDEN GLYNN AMZ450-452-101640- CW . ADJACENT COASTAL WATERS INCLUDED ARE COASTAL WATERS FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT 20 Read more

No watches are valid as of Wed Nov 9 18:01:02 UTC 2022.

No Mesoscale Discussions are in effect as of Wed Nov 9 18:01:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CST Wed Nov 09 2022 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHEAST FLORIDA INTO SOUTHERN/COASTAL GEORGIA AND SOUTH CAROLINA...AND PARTS OF THE UPPER MIDWEST...... ...SUMMARY... A few tornadoes should occur Thursday into Thursday night over parts of Florida into coastal Georgia and the Carolinas in association with Tropical Cyclone Nicole. Isolated strong to severe thunderstorms also appear possible across portions of the central Plains into the Upper Midwest, with damaging winds the main threat. ...Florida into Georgia and the Carolinas... The latest track from the NHC shows Tropical Cyclone Nicole over the central Florida peninsula Thursday morning. The track shows a northeastward turn through the day and the remnant surface low somewhere near central Georgia by 12Z Friday. This inland penetration of the center of the cyclone should allow a warm/moist warm sector to advance well inland across northeast Florida, eastern Georgia, and the eastern Carolinas. Low 70s dewpoints are likely with temperatures in the mid 70s which should be sufficient for 750-1000 J/kg MLCAPE. Despite the weakening surface low, guidance suggest the 925-850mb flow should maintain intensity of 50-55 knots through the day Thursday. In addition, some guidance suggests the low-level jet may strengthen after 06Z Friday morning as the tropical remnants start to interact with the larger trough to the west and low-level flow veers. At minimum, this should maintain a tornado threat through Thursday night/Friday into southeastern North Carolina. Additionally, it could potentially increase tornadic potential, particularly if surface winds can remain backed northeast of the cyclone while the low-level jet strengthens/veers, enlarging hodographs. Therefore, the slight risk has been expanded to include southeast North Carolina, primarily for the 06Z to 12Z period. The highest tornado potential will likely be near the Georgia and southern South Carolina coast. Shear and instability are expected to be greatest in this region with favorable diurnal timing during the afternoon hours Thursday. Most forecast soundings in this region show STP values around 1 with some guidance peaking around 2.5 for a few hours. In addition, most CAM guidance shows one or more well developed convective bands in the vicinity of this most favorable environment Thursday afternoon. ...Central Plains into the Upper Midwest... A fast-moving surface low will move across the Upper-Midwest on Thursday. Unseasonably high low-level moisture will be in place across the warm sector (low to mid 60s F dewpoints). As the upper trough advances east, convection is expected to develop along and ahead of the cold front across the eastern Plains into the Upper-Midwest by early afternoon as convective temperatures are met. Mid level lapse rates should limit overall storm intensity. However, storms will be developing within a moderately strong wind field with a ~45 knot low-level jet. Therefore, some severe wind gusts may be possible with these storms, particularly those along the front whose updraft will be supported by the frontal convergence. Additionally, strong low-level speed shear may support a brief tornado threat, but this threat should be mitigated by veered surface flow and weak lapse rates. The duration of the severe weather threat will be limited by the narrow warm sector. Due to the fast storm motion, most storms will likely move east of the best low-level moisture by 22-23Z and quickly face their demise. ..Bentley.. 11/09/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CST Wed Nov 09 2022 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN COLORADO... The previous forecast (see below) remains on track, and only minor adjustments were made to the Critical area in eastern CO based on the latest observational data and high-resolution guidance. ..Weinman.. 11/09/2022 .PREV DISCUSSION... /ISSUED 0122 AM CST Wed Nov 09 2022/ ...Synopsis... A surface low will deepen across the Central Plains on Wednesday with strong surface winds and very dry conditions across eastern Colorado/southwestern Nebraska just west of the dryline. Critical fire weather conditions are expected, with a few localized areas approaching Extremely Critical in eastern Colorado. Surface high pressure will bring very dry conditions across portions of the eastern US with Elevated fire weather concerns in Eastern Kentucky and West Virginia. ...Eastern CO, Southeastern WY, and Southwestern NE... Critical fire weather is expected in eastern Colorado on Wednesday with the most favorable conditions for rapid growth of new fires across eastern Colorado. In this region, southwest surface winds sustained at 20-25 mph (locally higher around 30 mph gusting up to 50 mph) will combine with afternoon minimum relative humidity around 10-15 percent (locally dropping below 10 percent). In addition to the dry conditions and strong winds, temperatures will be above normal, with highs approaching the mid to upper 70s. Fuels in this region are critically dry, with ERCs in the 80-90th percentile for dryness. Fuels, in combination with the dry and gusty conditions, support a Critical delineation. A few isolated areas may briefly approach Extremely Critical. Outside of the Critical area, Elevated fire weather can be expected across far eastern Colorado, southwestern Wyoming, and southwestern Nebraska. Winds are expected to be around 15-20 mph with afternoon minimum relative humidity around 15-20 percent. Trends will need to be monitored closely in the position of the dryline and potential extension of the Elevated area. ...Eastern KY and West Virginia... Very dry conditions are expected across portions of eastern Kentucky and West Virginia on Wednesday, with a corridor of minimum relative humidity approaching 20-25 percent (locally as low as 15 percent). Winds in this region will be around 10-15 mph. Given the very dry fuels (above 80th percentile for dryness), warm temperatures, and recent fire activity across western and eastern Kentucky on Tuesday, an Elevated delineation is supported even with marginal winds. ...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 1030 AM CST Wed Nov 09 2022 Valid 091630Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE EASTERN FLORIDA PENINSULA...MAINLY LATE TONIGHT.... ...SUMMARY... A tornado threat is expected to develop this evening and persist tonight over parts of eastern Florida. Isolated damaging thunderstorm gusts may occur before dawn tomorrow in parts of the central Plains. ...Eastern FL... Tropical Storm Nicole will track eastward and approach the east coast of the FL Peninsula tonight. As the center approaches, surface winds along the east-central/northeast coast will back to easterly and eventually southeasterly, aiding in the transport of rich low-level moisture and high theta-e air. This, along with rapidly strengthening shear profiles, will result in an increasing risk of a few tornadoes. The threat is not expected to begin until after midnight tonight. ...NE/KS... A strong surface boundary extends from eastern CO into central NE today. A deep surface low is expected to form this afternoon in eastern CO as an upper trough approaches, then track eastward along the boundary tonight. Most model solutions suggest a narrow band of shallow convection will form in vicinity of this low as it tracks eastward across parts of southern NE/northern KS. Instability will be weak, but perhaps sufficient for locally gusty/damaging winds along the line - mainly after midnight. ..Hart/Lyons.. 11/09/2022 Read more

No watches are valid as of Tue Nov 8 17:58:02 UTC 2022.

MD 1928 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF COASTAL SOUTHERN CALIFORNIA.
Mesoscale Discussion 1928 NWS Storm Prediction Center Norman OK 1136 AM CST Tue Nov 08 2022 Areas affected...portions of coastal Southern California. Concerning...Severe potential...Watch unlikely Valid 081736Z - 082000Z Probability of Watch Issuance...5 percent SUMMARY...Shoreward moving bands of low-topped convection may pose an isolated risk for strong/damaging wind gusts and or a brief tornado through the early afternoon. A weather watch is not expected. DISCUSSION...Morning water-vapor imagery showed a well-developed upper trough and strong cyclonically curved jet streak moving onshore across portions of the West Coast. A cold front and convergence band associated with the main upper wave are forecast to move toward the near coast supporting a couple of bands of low-topped convection through the morning and early afternoon. Moist onshore flow will allow for weak destabilization in the lowest few kilometers with forecast soundings showing 300-500 J/kg of MUCAPE ahead of the front. Very strong low/mid level wind fields will also be present with 0-6 km bulk shear of 60-70 kt favorable for storm organization into a QLCS. Orographic convergence may result in backing of the near-surface winds over the LA Basin and near shore aiding in a localized risk of a few strong/damaging wind gusts or perhaps a brief tornado over the next few hours. Given very limited buoyancy and uncertainty with storm coverage, a weather watch is not expected. ..Lyons/Hart.. 11/08/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGX...HNX...LOX... LAT...LON 34922068 34891904 34621766 34001718 33591722 33321744 33561804 33831888 33941939 33911981 33922022 33992062 34272084 34712093 34922068 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CST Tue Nov 08 2022 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE FLORIDA PENINSULA... ...SUMMARY... A couple tornadoes appear possible mainly Wednesday evening/night into early Thursday morning across parts of the Florida Peninsula. ...Florida... Tropical Cyclone Nicole will likely be centered just east of the northern Bahamas early Wednesday morning. Expectations is that this cyclone will make steady westward progress throughout the day and overnight, reaching the coast late Wednesday night/early Thursday morning. Northwesterly flow will strengthen through the day as the system approaches. However, thermodynamics throughout the western periphery of the system are expected to remain unfavorable for deep convection, limiting the overall severe potential throughout the day. An increased severe potential is anticipated later Wednesday evening into Thursday morning as greater low-level moisture attendant to the center of the cyclone moves into the coastal areas. This increase in moisture/buoyancy may result in few strong, more sustained updrafts and the potential for a tornado or two. Primary threat area is currently expected to extend from the Lake Okeechobee vicinity to south of Jacksonville Wednesday evening through Thursday morning. ...Northern/Central Plains into the Upper Midwest... Showers and isolated thunderstorms will likely be ongoing across the Upper Midwest early Wednesday amid a warm-air advection regime fostered by an expansive low-level jet over the Plains. Strong vertical shear will be in place but poor lapse rates and modest buoyancy should keep the severe potential limited. Surface cyclogenesis is anticipated over the central High Plains throughout the day as a strong shortwave trough pivots through the deep mean troughing over the western CONUS. Resultant surface low is then forecast move northeastward across NE and through the Mid MO Valley overnight. Additional thunderstorm development is anticipated along and north of a sharpening warm front associated with low, primarily from western SD across MN. Buoyancy will be slightly better than with the early morning storms, so a few storms may become strong enough to produce hail. However, coverage is still expected to remain less than 5%. Shallow convection in also anticipated along the front as it moves across NE and north-central KS early Thursday morning. Depth of the updrafts should be mitigated by warm mid-level temperatures, likely limiting lightning potential. Even so, given the robust low-level flow in place, a few strong, convectively augmented gusts are still possible. ..Mosier.. 11/08/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1047 AM CST Tue Nov 08 2022 Valid 081700Z - 091200Z No changes. See previous discussion below. ..Bentley.. 11/08/2022 .PREV DISCUSSION... /ISSUED 0110 AM CST Tue Nov 08 2022/ ...Synopsis... As an upper-level low deepens across the West Coast, lee troughing will continue to bring gusty surface winds and dry conditions across eastern Colorado. Across the eastern US, surface gradients will increase between a surface high over Ontario/Quebec and developing Subtropical Storm Nicole, bringing dry and breezy conditions across portions of Central South Carolina and Georgia. ...Eastern Colorado... South to southwesterly surface winds sustained at 20 mph (with gusts 30-40 mph) along with afternoon minimum relative humidity around 15-20 percent will be possible on Tuesday afternoon. Fuels are drying, with ERCs approaching the 80th percentile, especially across the plains of eastern Colorado. Given the duration and uncertainty on exactly how widespread the driest conditions will be, an Elevated delineation was included. Localized brief critical conditions may be possible. ...Central South Carolina and eastern Georgia... Northeasterly winds will be sustained around 10-15 mph with afternoon minimum relative humidity around 25-30 percent across portions of central South Carolina and eastern Georgia. Fuels in this region are marginal, given recent rainfall, but some drying has been reported in the 10-hour fuels. Given the winds and low afternoon relative humidity, an Elevated delineation has been included. ...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 1026 AM CST Tue Nov 08 2022 Valid 081630Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF SOUTHERN CALIFORNIA... ...SUMMARY... Isolated gusty/damaging wind gusts and/or a brief tornado are possible in parts of southern California this afternoon and evening. ...Los Angeles Basin... A large upper trough is in place today across the western US. Multiple weak cold fronts are sweeping eastward from the offshore waters onto coastal CA today, with one noted currently over the LA Basin, and another approaching Point Conception. This second wave is expected to move into the LA Basin around peak heating this afternoon, accompanied with a narrow line of showers and low-topped thunderstorms. Forecast soundings suggest 300-500 J/kg of CAPE ahead of the front, along with very strong low/mid level winds. Orographic effects may result in local backing of the near-surface winds over the LA Basin, enhancing convergence and aiding in a localized risk of a few damaging wind gusts or perhaps a brief tornado. Therefore have added low wind and tornado probabilities for this area - mainly during the 21-03z period. ..Hart/Lyons.. 11/08/2022 Read more

No watches are valid as of Mon Nov 7 17:39:02 UTC 2022.

No Mesoscale Discussions are in effect as of Mon Nov 7 17:39:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CST Mon Nov 07 2022 Valid 081200Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely on Tuesday. ...California/Nevada... An upper trough/low will progress slowly eastward over the western CONUS on Tuesday. A strong mid-level jet and associated large-scale ascent should aid convective development across parts of CA/NV through the period. Instability is forecast to remain limited and convection is expected to be low-topped beneath a warm layer located around 7-10 kft, but isolated lightning flashes will be possible across the region. Low/mid-level winds will be fairly strong across parts of central/southern CA into southern NV, but very weak instability (MUCAPE 300 J/kg or less) should limit the threat for more robust convection. Nevertheless, forecast hodographs indicate some rotation will be possible in showers/isolated thunderstorms, especially as they move onshore the southern/central CA coast. Gusty winds may accompany any more robust convection that can develop, but overall severe potential is expected to remain low. ...Southern Plains Vicinity... Thunderstorms are expected to be ongoing Tuesday morning in a low-level warm advection regime. Southerly low-level flow will bring Gulf moisture northward across the southern Plains though the period, though only modest boundary-layer dewpoints are expected with westward extent into the southern High Plains. Deep layer shear will be favorable for organized convection. However, severe potential appears rather limited/conditional given nebulous forcing for ascent (with neutral to slightly rising heights), and a low-level inversion limiting surface-based convective potential. Some small hail could accompany the strongest cells across OK, but convective initiation further west into parts of western TX/eastern NM is questionable. Severe probabilities are not expected at this time given the low-end and conditional nature of the threat. ...Upper Midwest Vicinity... An upper ridge will be oriented over the Upper Midwest/Great Lakes early Tuesday. As the upper trough shifts east over the western states, a weak shortwave impulse is forecast to migrate across the northern Plains and shift the upper ridge eastward into Quebec and the northeast U.S. Modest height falls/large-scale ascent, and increasing midlevel moisture will support the development of showers and isolated elevated thunderstorms. However, instability will remain limited and severe potential is expected to remain low. ..Leitman.. 11/07/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Mon Nov 07 2022 Valid 071700Z - 081200Z No changes. See previous discussion below. ..Bentley.. 11/07/2022 .PREV DISCUSSION... /ISSUED 1245 AM CST Mon Nov 07 2022/ ...Synopsis... As a trough deepens across the Pacific Northwest, lee troughing will develop across the High Plains with increasing south to southeasterly flow and dry conditions on Monday. South to southeasterly winds will be sustained around 15-20 mph (locally higher around 25-30 mph with gusts 40-50 mph) across portions of south-central North Dakota, central South Dakota, and north-central Nebraska on Monday. Afternoon relative humidity will be around 20-30 percent. Mid-level cloud cover still looks likely, which could play a part in reducing high temperatures and keeping relative humidity a bit higher than forecast. HREF probabilities have come up this evening indicating a 70-80 percent chance of Elevated conditions occurring, which is in good agreement with most of the deterministic guidance. Given the condition of fuels (ERCs above largely above 90th percentile) and the strong winds, have kept an Elevated delineation in place. ...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 1006 AM CST Mon Nov 07 2022 Valid 071630Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely through tonight. ...Southern Plains... A broad upper trough is present today over much of the western US, while an upper ridge extends from the southern Plains into the OH Valley. Scattered showers and isolated thunderstorms have been occurring along a weak retreating warm front that extends from central TX into AR/MS. Convection is expected to become a little more widespread after dark as the zone of low-level warm advection spreads northward into parts of OK. No severe storms are anticipated with this activity. ...Western States... Very cold temperatures aloft and strong onshore low/mid level winds will promote scattered showers and isolated thunderstorms offshore moving into coastal areas of OR and northern/central CA. A few of these cells could produce small hail or funnel clouds. However, the overall severe threat appears low. ..Hart/Lyons.. 11/07/2022 Read more

No watches are valid as of Sun Nov 6 17:50:02 UTC 2022.