SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CST Fri Nov 22 2024 Valid 241200Z - 251200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected across the USA Sunday. ...Synopsis... On Sunday, an upper trough will depart the northeastern states as an elongated mid/upper level speed max extends across the Four Corners states and into the Plains. This feature will phase with an upper low/trough extending from southern SK/MB into the northern Plains, with ridging over the East. A low pressure trough will exist ahead of the cold front from the upper MS Valley into the southern High Plains around 00Z, extending from Lower MI into northern TX by 12Z Monday. Ahead of this front, southerly winds will result in a batch of low 60s F dewpoints from eastern TX toward AR, but the air mass should remain capped with little of any convection along the intersecting cold front. Elsewhere, cool air aloft will remain over much of the northwestern states, with little if any instability to support thunderstorms. ..Jewell.. 11/23/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 PM CST Fri Nov 22 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible today from parts of the West Coast into the northern Rockies. No severe threat is expected. ...DISCUSSION... A mid-level ridge will move across the central U.S. as a mid-level shortwave trough moves across the northwestern states. Thunderstorms will be possible near and ahead of the trough along parts of the West Coast, Intermountain West, and northern Rockies. No severe threat is expected today or tonight. ..Broyles/Squitieri.. 11/23/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 PM CST Fri Nov 22 2024 Valid 230100Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur this evening from the coasts of Washington and Oregon southeastward into the northern Sierras, but no severe threat is expected. ...DISCUSSION... A mid-level shortwave trough will approach the West Coast this evening. A chance of thunderstorms will exist ahead of the trough in an area of steep mid-level lapse rates and strong large-scale ascent. The potential for thunderstorm activity will be from the coasts of Washington and Oregon southeastward into the northern Sierras. Elsewhere across the continental U.S., thunderstorms are not expected. ..Broyles.. 11/23/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0644 PM CST Fri Nov 22 2024 Valid 230100Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms may occur this evening from the coasts of Washington and Oregon southeastward into the northern Sierras, but no severe threat is expected. ...DISCUSSION... A mid-level shortwave trough will approach the West Coast this evening. A chance of thunderstorms will exist ahead of the trough in an area of steep mid-level lapse rates and strong large-scale ascent. The potential for thunderstorm activity will be from the coasts of Washington and Oregon southeastward into the northern Sierras. Elsewhere across the continental U.S., thunderstorms are not expected. ..Broyles.. 11/23/2024 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Fri Nov 22 2024 Valid 241200Z - 301200Z The large scale pattern will be characterized by troughing across the west and eastern US and increasing zonal westerly flow into the central US. The western trough will bring several rounds of precipitation across the western US through early next week, which will aid in limiting fuel concerns. Similarly, several rounds of precipitation and cooler temperatures will limit fuel concerns across the eastern US, though some breezy post-frontal winds will be likely. With the increase in zonal flow and enhancement of westerly flow across the Rockies, some areas of dry/windy conditions will be possible in the lee of the southern Rockies. Some dry/wind conditions may extend to the southern Plains as lee troughing increases across the High Plains by the weekend. Recent precipitation and cold air intrusion should limit fire weather concerns. ..Thornton.. 11/22/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Fri Nov 22 2024 Valid 241200Z - 301200Z The large scale pattern will be characterized by troughing across the west and eastern US and increasing zonal westerly flow into the central US. The western trough will bring several rounds of precipitation across the western US through early next week, which will aid in limiting fuel concerns. Similarly, several rounds of precipitation and cooler temperatures will limit fuel concerns across the eastern US, though some breezy post-frontal winds will be likely. With the increase in zonal flow and enhancement of westerly flow across the Rockies, some areas of dry/windy conditions will be possible in the lee of the southern Rockies. Some dry/wind conditions may extend to the southern Plains as lee troughing increases across the High Plains by the weekend. Recent precipitation and cold air intrusion should limit fire weather concerns. ..Thornton.. 11/22/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2241 CONCERNING HEAVY SNOW FOR THE HIGHER TERRAIN ACROSS WESTERN PENNSYLVANIA...NORTHERN WEST VIRGINIA...AND FAR WESTERN MARYLAND.
Mesoscale Discussion 2241 NWS Storm Prediction Center Norman OK 1256 PM CST Fri Nov 22 2024 Areas affected...the higher terrain across western Pennsylvania...northern West Virginia...and far western Maryland. Concerning...Heavy snow Valid 221856Z - 222300Z SUMMARY...Snowfall rates of 1 to 2 inches per hour this afternoon and evening. DISCUSSION...Snowfall rates have increased across the central Appalachians in western Pennsylvania, northern West Virginia, and far western Maryland as upslope flow strengthens and temperatures cool aloft. The strongest west-northwesterly flow (45 to 50 knots) will persist through 06Z before weakening. Snowfall rates of 1 to 2 inches per hour are expected through much of this period. Some snow is expected at lower elevation/valley locations, but a marginal thermodynamic environment should limit snowfall accumulation rates at these lower elevations. In addition, some blizzard conditions are possible at the highest peaks where 50+ knots of winds are occurring and expected to continue through the overnight period. ..Bentley.. 11/22/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CTP...LWX...PBZ...RLX... LAT...LON 39727991 40497949 41007925 41257897 41227864 41047843 40467856 39697910 39297940 39077956 39017980 39078010 39208025 39727991 Read more

No watches are valid as of Fri Nov 22 22:01:02 UTC 2024.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Fri Nov 22 2024 Valid 231200Z - 241200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 11/22/2024 .PREV DISCUSSION... /ISSUED 1153 PM CST Thu Nov 21 2024/ ...Synopsis... Upper ridging will occur over the central U.S. as a low-amplitude mid-level trough overspreads the Southwest tomorrow (Saturday). Adequate precipitation accumulations along the West Coast toward the Rockies, as well as relatively weak surface wind fields east of the Rockies, should limit widespread significant wildfire-spread potential across most of the CONUS. Given the expected quiescent fire weather conditions across the CONUS, no fire weather highlights have been introduced this outlook. ...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 0143 PM CST Fri Nov 22 2024 Valid 222000Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely through tonight. ...Discussion... No changes have been made to the ongoing thunder area near the West Coast. Very low-topped convection from Grays Harbor northward along the WA coast may contain weak, transient circulations this afternoon over the offshore waters amid strong low-level shear. Instability on land is expected to remain too flimsy to support a brief tornado risk. ..Grams.. 11/22/2024 .PREV DISCUSSION... /ISSUED 1028 AM CST Fri Nov 22 2024/ ...Synopsis... A relatively dry and stable air mass is present over a large part of the CONUS today, preventing thunderstorm potential in most areas. The one exception will be associated with a deep upper low off the Pacific Northwest coast. Strong onshore flow and cold temperatures aloft will result in pockets of thunderstorms along the coastal ranges and mountains of northern CA throughout the forecast period. No severe storms are anticipated. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CST Fri Nov 22 2024 Valid 241200Z - 251200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected across the USA Sunday. ...Synopsis... A low amplitude, mostly zonal, mid-level flow regime will persist across the US Sunday, as weak ridging over the central states shifts eastward. A shortwave trough, embedded within strong westerly flow aloft, will eject into the central Plains as a second, weaker trough approaches the West Coast early Monday. A lee low should steadily deepen over the central Plains and Midwest ahead of the advancing shortwave trough, while high pressure remains steady over the Southeast. Weak moisture return is expected across parts of the Plains and ArkLaTex as the low deepens and moves east. However, low and mid-level lapse rates will remain poor, with strong inhibition negating thunderstorm potential. Elsewhere, little to no buoyancy is expected across the CONUS outside of the near coastal waters of WA and OR. Given the poor lapse rates and weak inland moisture advection, any low-topped thunderstorms that do develop are expected to remain transient and offshore. ..Lyons.. 11/22/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CST Fri Nov 22 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow over the CONUS will continue to deamplify as a large trough moves offshore in the East. Shortwave ridging over the central US will weaken as it moves east behind the departing trough. Over the West, broad troughing and strong mid-level flow will gradually move inland, with a lead shortwave reaching the northern Rockies by early Sunday. At the surface, high pressure will shift eastward with offshore flow over the eastern third of the US. At the same time, a weak surface low and cold front associated with the lead shortwave, will translate through the Great Basin and northern Rockies before intensifying on the leeward side. A few lightning flashes are possible with low-topped storms ahead of the cold front over the northern Rockies Saturday. Isolated storms are also possible along the Pacific Coast beneath the broad trough with onshore flow and weak destabilization. Otherwise, cool, dry and stable conditions will prevent thunderstorms over the remainder of the CONUS. ..Lyons.. 11/22/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CST Fri Nov 22 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow over the CONUS will continue to deamplify as a large trough moves offshore in the East. Shortwave ridging over the central US will weaken as it moves east behind the departing trough. Over the West, broad troughing and strong mid-level flow will gradually move inland, with a lead shortwave reaching the northern Rockies by early Sunday. At the surface, high pressure will shift eastward with offshore flow over the eastern third of the US. At the same time, a weak surface low and cold front associated with the lead shortwave, will translate through the Great Basin and northern Rockies before intensifying on the leeward side. A few lightning flashes are possible with low-topped storms ahead of the cold front over the northern Rockies Saturday. Isolated storms are also possible along the Pacific Coast beneath the broad trough with onshore flow and weak destabilization. Otherwise, cool, dry and stable conditions will prevent thunderstorms over the remainder of the CONUS. ..Lyons.. 11/22/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Fri Nov 22 2024 Valid 221700Z - 231200Z No changes are need to the current D1 Fire Weather Outlook. See previous discussion for more information below. ..Thornton.. 11/22/2024 .PREV DISCUSSION... /ISSUED 1150 PM CST Thu Nov 21 2024/ ...Synopsis... A pronounced mid-level trough will eject into the Atlantic as a second mid-level trough impinges on the West Coast today. Ample precipitation accumulations should accompany both mid-level troughs along the West and East Coast shorelines, reducing wildfire-spread potential in these areas. Surface high pressure will also support cooler surface conditions and minimal wildfire-spread potential across much of the central U.S. The only notable area for fire weather concerns is across the northern FL Peninsula. Here, northwesterly surface flow within a post-cold front environment will support 15 mph sustained winds amid 25-35 percent RH by afternoon peak heating. Given at least marginally receptive fuels available for wildfire spread, Elevated highlights have been introduced. ...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 1028 AM CST Fri Nov 22 2024 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely through tonight. ...Synopsis... A relatively dry and stable air mass is present over a large part of the CONUS today, preventing thunderstorm potential in most areas. The one exception will be associated with a deep upper low off the Pacific Northwest coast. Strong onshore flow and cold temperatures aloft will result in pockets of thunderstorms along the coastal ranges and mountains of northern CA throughout the forecast period. No severe storms are anticipated. ..Hart/Bentley.. 11/22/2024 Read more

No Mesoscale Discussions are in effect as of Fri Nov 22 14:42:01 UTC 2024.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Fri Nov 22 2024 Valid 221300Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely through tonight. ...Synopsis/Discussion... A well-amplified mid/upper-level pattern features synoptic-scale cyclones on either side of the CONUS: 1. In the East, the cyclone core is elongated west-southwest/east- northeast from WV to southern New England, occasionally exhibiting two centers at 500 mb. This cyclone should pivot offshore gradually, with a more consolidated center south of RI and east of NJ by 12Z tomorrow. Associated thunder tonight should remain offshore. 2. For the Pacific cyclone, a double center was evident as well, with the strongest, closest, and most important one being near 45N131W. This is becoming the primary low as the other one well to the west devolves into an open shortwave trough. The eastern low should pivot northward, offshore from the Northwest Coast, toward Vancouver Island. Meanwhile, a series of small shortwaves and vorticity lobes will move ashore in the preceding southwest flow, predominantly this afternoon through tonight -- each contributing shots of cooling/destabilization aloft, and atop the weakly unstable marine air mass. Forecast soundings accordingly suggest that the midlevel inversion should rise/cool such that modest buoyancy (overland MUCAPE generally under 250 J/kg) extends upward into icing layers suitable for at least isolated/brief lightning, especially from around 00Z onward. A few thunderstorms are possible near the coast, as well as embedded in the deep low/middle-level moisture fetch impinging on higher terrain in northern CA. ..Edwards.. 11/22/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0338 AM CST Fri Nov 22 2024 Valid 251200Z - 301200Z ...DISCUSSION... Models are in good agreement with the general pattern on Mon/D4, depicting a midlevel speed max nosing into the central Plains Monday morning, then phasing with an upper trough over the northern Plains. This should then result in an amplified shortwave trough moving across the Midwest and Great Lakes through Tue/D5 morning. An associated cold front will shunt the young moist plume back south toward the Gulf Coast. This trough is then expected to eject northeastward toward Quebec into Tue/D5, with a zonal flow regime across the CONUS on Wed/D6, with slow moisture return. Beyond this time frame, subtle differences exist regarding how quickly the pattern may amplify, as ridging occurs over the West, and a possible trough develops from the southern Plains into the southeastern states. Any appreciable low-level moisture return and destabilization would likely be tied to such a trough amplification, which is low predictability. In short, a non-zero threat of severe storms may develop over parts of the Gulf Coast states, Thu/D7 into Fri/D8, as moisture increases and flow aloft remains strong. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Fri Nov 22 2024 Valid 241200Z - 251200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Little if any thunderstorms are expected across the USA on Sunday. ...Synopsis... An upper low will remain over the Canadian Maritimes for much of the day Sunday, and will shift east overnight as upper ridging occurs over the Midwest and Lower Great Lakes. To the west, height falls will spread east across much of the West during the day and into the Plains overnight, with a lead trough extending from Manitoba into the northern and central Plains by 12Z Monday. At the surface, high pressure will remain over the Southeast, with a trough developing from the upper MS Valley southwestward to the southern High Plains 00Z. Southerly winds will increase over the western Gulf of Mexico, with increasing surface to 850 mb southwesterlies aiding low-level moisture transport. While the air mass from eastern TX into the lower MS Valley will continually moisten, lapse rates will remain poor, and therefore, thunderstorms are not forecast in this region. Elsewhere, very weak instability may again develop near the shores of WA and OR, but the bulk of any low-topped thunderstorms are expected to remain offshore. ..Jewell.. 11/22/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Fri Nov 22 2024 Valid 241200Z - 251200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Little if any thunderstorms are expected across the USA on Sunday. ...Synopsis... An upper low will remain over the Canadian Maritimes for much of the day Sunday, and will shift east overnight as upper ridging occurs over the Midwest and Lower Great Lakes. To the west, height falls will spread east across much of the West during the day and into the Plains overnight, with a lead trough extending from Manitoba into the northern and central Plains by 12Z Monday. At the surface, high pressure will remain over the Southeast, with a trough developing from the upper MS Valley southwestward to the southern High Plains 00Z. Southerly winds will increase over the western Gulf of Mexico, with increasing surface to 850 mb southwesterlies aiding low-level moisture transport. While the air mass from eastern TX into the lower MS Valley will continually moisten, lapse rates will remain poor, and therefore, thunderstorms are not forecast in this region. Elsewhere, very weak instability may again develop near the shores of WA and OR, but the bulk of any low-topped thunderstorms are expected to remain offshore. ..Jewell.. 11/22/2024 Read more