SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1153 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO CRITICAL AREAS... ...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. ..Squitieri.. 11/22/2024 ...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 1150 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...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. ..Squitieri.. 11/22/2024 ...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 1139 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... On Saturday, a large upper trough will move out of the northeastern states, with a weak upper ridge moving across the Plains and toward the MS Valley. To the west, a large upper trough will continue eastward across the Great Basin and much of the central and northern Rockies. A lead wave will likely pivot northeastward toward the Dakotas late. At the surface, a large area of high pressure will exist from the southern Plains into the Southeast, maintaining stable conditions. Low pressure will exist ahead of a cold front from the eastern Great Basin into the northern High Plains by late in the day. A low chance of a few lightning flashes may exist along the coastal Pacific Northwest where cold temperatures aloft may result in weak buoyancy. Otherwise, minimal activity will be possible over parts of central ID and vicinity as lapse rates steepen. ..Jewell.. 11/22/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible today in the Pacific Coastal states. No severe storms are not expected today or tonight across the continental U.S. ...DISCUSSION... A mid-level low will remain over the vicinity of southeast New York today as a mid-level ridge stays over the Rockies. In the eastern Pacific, a mid-level trough will approach the West Coast. A few thunderstorms may develop ahead of the system from the Washington and Oregon coasts southeastward into the northern Sierras. No severe thunderstorms are expected. ..Broyles/Squitieri.. 11/22/2024 Read more

MD 2240 CONCERNING HEAVY SNOW FOR THE CATSKILLS AND POCONOS VICINITY OF NORTHEASTERN PENNSYLVANIA AND SOUTHEASTERN NEW YORK
Mesoscale Discussion 2240 NWS Storm Prediction Center Norman OK 1023 PM CST Thu Nov 21 2024 Areas affected...the Catskills and Poconos vicinity of northeastern Pennsylvania and southeastern New York Concerning...Heavy snow Valid 220423Z - 220830Z SUMMARY...Snowfall rates of an inch per hour are expected locally across parts of southeastern New York and northeastern Pennsylvania, specifically over the higher terrain in the Catskills and Poconos vicinity. DISCUSSION...As an upper low centered over southwestern Pennsylvania moves slowly east-southeastward, a surface low currently analyzed over the eastern Long Island vicinity will continue to retrograde northwestward across southern New England and eventually into southeastern New York. Strong low-level warm advection north of the low is resulting in widespread moderate to heavy precipitation -- mostly in the form of rain -- across southern New England and into eastern New York, northeastern Pennsylvania, and northern New Jersey. However, temperatures near or slightly below freezing are indicated across the higher terrain areas including the Poconos and Catskills, where moderate to locally heavy snow is occurring (moderate snow is now being reported at the BGM obs site). Given the rather slow movement of the upper system, QG ascent across the discussion area should remain strong over the next 3 to 6 hours. As such, expect locally heavy snow -- at rates near an inch per hour -- to persist through midnight and into early Friday morning. ..Goss/Guyer.. 11/22/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ALY...PHI...BGM...CTP... LAT...LON 42677447 42397416 41817439 41547501 41107548 41177575 41367590 41477650 41887688 42867614 42917505 42677447 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0646 PM CST Thu Nov 21 2024 Valid 220100Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected across the continental U.S. through tonight. ...DISCUSSION... A mid-level low will move eastward toward the Mid-Atlantic coast tonight, as an upper-level ridge moves through the Rockies. At the surface, a cool and dry airmass will remain over most of the nation, making conditions unfavorable for thunderstorms through this evening and tonight. ..Broyles.. 11/22/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0646 PM CST Thu Nov 21 2024 Valid 220100Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected across the continental U.S. through tonight. ...DISCUSSION... A mid-level low will move eastward toward the Mid-Atlantic coast tonight, as an upper-level ridge moves through the Rockies. At the surface, a cool and dry airmass will remain over most of the nation, making conditions unfavorable for thunderstorms through this evening and tonight. ..Broyles.. 11/22/2024 Read more

No watches are valid as of Thu Nov 21 22:26:01 UTC 2024.

No Mesoscale Discussions are in effect as of Thu Nov 21 22:26:01 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0316 PM CST Thu Nov 21 2024 Valid 231200Z - 291200Z Fire weather concerns remain limited through the extended period. The upper trough over the Great Lakes/Ohio River Valley will continue to promote widespread rain/snow chances across these regions and into the Northeast over the next 48 hours. The precipitation associated with this system, combined with seasonal temperatures over the next several days, will limit fuel concerns across the northern/northeastern CONUS. A breakdown of the upper ridge over the central U.S. will transition into a more zonal flow regime over this weekend. As this occurs, increasing west/southwesterly mid-level flow - augmented by transient shortwave troughs - may promote areas of dry/windy conditions in the lee of the southern Rockies. Additionally, a dry return flow regime may become established across the southern Plains this weekend as a lee trough deepens along the High Plains; however, recent widespread rainfall should limit fuel status. This regime will be short-lived as cold air intrusions overspread the Plains behind a deepening surface low during the early to mid-week period. Recent precipitation, cool temperatures, and weak gradient winds should limit fire concerns across the western CONUS. ..Moore.. 11/21/2024 ...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 0316 PM CST Thu Nov 21 2024 Valid 231200Z - 291200Z Fire weather concerns remain limited through the extended period. The upper trough over the Great Lakes/Ohio River Valley will continue to promote widespread rain/snow chances across these regions and into the Northeast over the next 48 hours. The precipitation associated with this system, combined with seasonal temperatures over the next several days, will limit fuel concerns across the northern/northeastern CONUS. A breakdown of the upper ridge over the central U.S. will transition into a more zonal flow regime over this weekend. As this occurs, increasing west/southwesterly mid-level flow - augmented by transient shortwave troughs - may promote areas of dry/windy conditions in the lee of the southern Rockies. Additionally, a dry return flow regime may become established across the southern Plains this weekend as a lee trough deepens along the High Plains; however, recent widespread rainfall should limit fuel status. This regime will be short-lived as cold air intrusions overspread the Plains behind a deepening surface low during the early to mid-week period. Recent precipitation, cool temperatures, and weak gradient winds should limit fire concerns across the western CONUS. ..Moore.. 11/21/2024 ...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 0144 PM CST Thu Nov 21 2024 Valid 212000Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A line of convective rain/show showers continues across the Appalachians with occasional lightning flashes. This will persist for a few more hours before weakening late this afternoon as the boundary layer cools and low-level lapse rates weaken. Lightning is expected to remain offshore near the New England coast and the Pacific Northwest coast and therefore, the thunder line has been removed from both areas. ..Bentley.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1029 AM CST Thu Nov 21 2024/ ...Synopsis... A deep midlevel low, characterized by 500-mb temperatures around -32C, will move from the Great Lakes into the Mid-Atlantic through the period. These cold midlevel temperatures and strong height falls accompanying the midlevel low may promote isolated lightning flashes embedded in showers across the central Appalachians this afternoon. Over coastal southern New England, low-level warm advection north of a related occluded surface low will also support isolated thunderstorms, given weak elevated instability. Most of this activity should remain offshore. Isolated thunderstorms are also possible over immediate coastal areas of WA, where forcing for ascent in the left exit region of a jet streak is overlapping deep tropospheric moisture/weak instability. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Thu Nov 21 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms appear unlikely across the CONUS Saturday. ...Synopsis... Mid-level flow across the CONUS is forecast to become more zonal with time as prominent troughing on either coast gradually deamplifies. Ridging over the central CONUS will weaken and shift eastward as the East Coast trough moves offshore. To the west, strong mid-level flow will move inland across the Pacific Northwest and northern Rockies as the upper low cuts off southwest of BC. A weak surface low and cold front will move across the northern Rockies and intensify over the High Plains. High pressure over the eastern US will favor cool, dry and stable offshore flow across the eastern half of the country. ...Northwest and Northern Rockies... As the broad upper-level cyclone over the Pacific Northwest gradually devolves, a lead shortwave trough embedded within the stronger zonal flow will quickly eject eastward over the Northern Rockies. A weak surface low and trailing cold front will also move east with the stronger flow aloft. Area model soundings show weak destabilization is possible over parts of eastern OR and southern ID as forcing for ascent increases and low-level lapse rates steepen ahead of the front. While very limited, enough buoyancy (MUCAPE ~100-200 J/kg) may develop for a few lightning flashes with low-topped, mixed-phase, convective elements. Additionally, low-topped storms may approach near shore areas of OR/WA and northern CA. However, cool inland surface temperatures and weakening large-scale ascent should limit lightning chances inland. ..Lyons.. 11/21/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1230 PM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... An Elevated risk area has been introduced for portions of central FL. Latest guidance has trended towards slightly stronger winds along the FL peninsula tomorrow as a secondary cold surge pushes across the region. Gusts up to 15-20 mph will be possible - especially during the late morning hours - with RH reductions into the 25-35% range. Dry/windy conditions today across the area and limited rainfall over the past three days should allow for adequate drying of fine fuels to support a fire concern. ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1151 PM CST Wed Nov 20 2024/ ...Synopsis... A similar upper-level pattern to Thursday will again be present on Friday. The strong upper low will continue east and a complex surface low evolution will occur off the Mid-Atlantic/New England coast. Fire weather conditions are expected to be minimal for most areas. Northern into central Florida will again be dry. Temperature will be a bit cooler and RH will be a bit higher. Boundary layer mixing will also be less than Thursday, tempering gust potential. With the strongest winds/lowest RH expected over less receptive fuels, highlights will be withheld. Locally elevated conditions can be expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CST Thu Nov 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few thunderstorms are possible along the Pacific Northwest Coast Friday. Severe storms are not expected. ...Synopsis... Amplified mid-level flow is likely over much of the CONUS Friday, with a deep upper low off the East Coast and a similarly deep trough off the West Coast. Between the two lows, a shortwave ridge will slowly migrate eastward over the central Plains. At the surface, a low and trailing cold front will steadily move offshore through the day over the East. High pressure and offshore flow are likely over the central CONUS. While along the West Coast, a pronounced low and onshore flow will continue. As the upper trough continues to shift eastward, cool and stable offshore flow should limit buoyancy and deep convection over the eastern 2/3rds of the CONUS. The only exception to this could be brief, low-topped storms near Cape Cod. A few deeper convective elements embedded within broad stratiform could produce sporadic lightning before stronger offshore flow shifts any lingering buoyancy completely offshore by midday. Across the Pacific Northwest, continuous onshore flow is likely as the cold core of the upper trough (-28 to -30 C 500 mb temps) moves onshore late in the day and overnight. Scattered low-topped convection will be most likely over the ocean overnight, but a few thunderstorms with sporadic lightning could move inland. With very weak MUCAPE (100-200 J/kg) any stronger updrafts will likely be brief. Strong deep-layer shear could briefly overlap with the buoyancy supporting a sporadic strong wind gust near the coast. However, the transient nature of the updrafts should keep the severe risk negligible. ..Lyons.. 11/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Nov 21 2024 Valid 211630Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today and tonight. ...Synopsis... A deep midlevel low, characterized by 500-mb temperatures around -32C, will move from the Great Lakes into the Mid-Atlantic through the period. These cold midlevel temperatures and strong height falls accompanying the midlevel low may promote isolated lightning flashes embedded in showers across the central Appalachians this afternoon. Over coastal southern New England, low-level warm advection north of a related occluded surface low will also support isolated thunderstorms, given weak elevated instability. Most of this activity should remain offshore. Isolated thunderstorms are also possible over immediate coastal areas of WA, where forcing for ascent in the left exit region of a jet streak is overlapping deep tropospheric moisture/weak instability. ..Weinman.. 11/21/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0926 AM CST Thu Nov 21 2024 Valid 211700Z - 221200Z The previous forecast remains on track with no changes required. Recent 15 UTC surface observations show winds increasing to around 15 mph with occasionally stronger gusts and RH falling into the 30-40% range. This aligns well with recent guidance and supports the ongoing forecast (outlined in the discussion below). ..Moore.. 11/21/2024 .PREV DISCUSSION... /ISSUED 1150 PM CST Wed Nov 20 2024/ ...Synopsis... With a strong upper low over the lower Great Lakes region, strong flow aloft will overspread portions of the Southeast into Florida. A deepening low east of the DelMarVa will promote enhanced surface wind behind the cold front. With minimal precipitation falling over North Florida, where fuels are quite dry for this time of year, a period of elevated fire weather is expected. Winds of 10-15 mph and RH perhaps near 20% in some spots can be expected by the afternoon. The boundary layer should also deepen sufficiently to support gusts of up to 20 mph. ...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 0630 AM CST Thu Nov 21 2024 Valid 211300Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today and tonight. ...Synopsis and Discussion... A mature mid/upper-level cyclone will move from the Great Lakes/OH Valley to the East Coast today. Modest low-level warm advection may support occasional elevated thunderstorms to the north of a front near Long Island NY. This activity should generally remain offshore. Otherwise, isolated lightning flashes may be noted with shallow convection today across parts of the central Appalachians, beneath cold mid-level temperatures associated with the upper low. Although low-level moisture and related MUCAPE are both forecast to remain meager, some of this activity may acquire sufficient depth to support charge separation. Finally, isolated convection producing occasional lightning may brush parts of the WA Coast through this afternoon. ..Gleason/Kerr.. 11/21/2024 Read more

MD 2238 CONCERNING HEAVY SNOW FOR PORTIONS OF EASTERN WISCONSIN INTO ADJACENT NORTHEASTERN ILLINOIS
Mesoscale Discussion 2238 NWS Storm Prediction Center Norman OK 0409 AM CST Thu Nov 21 2024 Areas affected...portions of eastern Wisconsin into adjacent northeastern Illinois Concerning...Heavy snow Valid 211009Z - 211345Z SUMMARY...An hour or two period of 1-2+ inch per hour snow rates appears possible early this morning, coincident with strong gusty winds resulting in blowing snow and reduced visibilities. This appears most likely to spread from near or just west of Green Bay southward through the Oshkosh vicinity and areas west of Milwaukee by around 8-9 AM CST. DISCUSSION...To the southwest of the lingering occluded surface cyclone over the upper peninsula of Michigan, sub-freezing thermodynamic profiles remain entrenched across much of Wisconsin, in the presence of strengthening lower/mid-tropospheric warm advection. This is occurring in advance of a southwestward then southward pivoting mid-level cyclonic vorticity center, which is forecast to be accompanied by strengthening northerly flow to 50-60 kt in the 850-700 mb layer across much of eastern Wisconsin. Associated strengthening of large-scale ascent is likely to continue contributing to saturation of thermodynamic profiles and the development of snow through 13-15Z. Models suggest that lift may become strong and focused near and just ahead of the mid-level cyclonic vorticity center, maximized within a layer near/above 700 mb with temperatures around -15C, and conducive to large dendritic ice crystal growth. It appears that this may be accompanied by a period of heavy snow rates on the order of 1-2+ inches per hour, coincident with strengthening, gusty surface winds. ..Kerr.. 11/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...LOT...MKX... LAT...LON 45018918 44728772 43868764 42428826 43148946 45018918 Read more