SPC Tornado Watch 134 Status Reports

2 years 3 months ago
WW 0134 Status Updates
STATUS REPORT ON WW 134 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 S SSI TO 20 SW CSG. ..KERR..04/13/23 ATTN...WFO...JAX...TAE...FFC... STATUS REPORT FOR WT 134 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS GAC001-005-023-025-039-053-069-079-081-091-093-127-145-153-161- 193-197-215-225-229-235-249-259-261-263-269-271-305-307-309-315- 132140- GA . GEORGIA COUNTIES INCLUDED ARE APPLING BACON BLECKLEY BRANTLEY CAMDEN CHATTAHOOCHEE COFFEE CRAWFORD CRISP DODGE DOOLY GLYNN HARRIS HOUSTON JEFF DAVIS MACON MARION MUSCOGEE PEACH PIERCE PULASKI SCHLEY STEWART SUMTER TALBOT TAYLOR TELFAIR WAYNE WEBSTER WHEELER WILCOX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

SPC Tornado Watch 134

2 years 3 months ago
WW 134 TORNADO GA 131640Z - 132300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 134 NWS Storm Prediction Center Norman OK 1240 PM EDT Thu Apr 13 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Georgia * Effective this Thursday afternoon and evening from 1240 PM until 700 PM EDT. * Primary threats include... A few tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms coverage and intensity will gradually increase through the afternoon. Severe thunderstorms capable of producing scattered damaging gusts, a few tornadoes and isolated large hail will be possible into early evening. The tornado watch area is approximately along and 55 statute miles north and south of a line from 20 miles southwest of Columbus GA to 30 miles north northeast of Jacksonville FL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 133... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Leitman Read more

SPC MD 510

2 years 3 months ago
MD 0510 CONCERNING TORNADO WATCH 134... FOR CENTRAL GEORGIA
Mesoscale Discussion 0510 NWS Storm Prediction Center Norman OK 0320 PM CDT Thu Apr 13 2023 Areas affected...central Georgia Concerning...Tornado Watch 134... Valid 132020Z - 132215Z The severe weather threat for Tornado Watch 134 continues. SUMMARY...At least low potential for convection capable of producing tornadoes will persist along a slowly northward advancing warm front zonal into early evening. A new Tornado Watch will probably be needed. DISCUSSION...A gradual northward and northeastward progression of a pair of narrow convective bands, and a focusing warm frontal zone for occasional thunderstorm intensification, continues into much of central Georgia. Although a substantial increase in the risk for tornadoes, beyond what has existed the past several hours, still appears unlikely, at least some risk probably will continue into early evening, before subsiding as the boundary-layer near the front stabilizes with nocturnal cooling. ..Kerr.. 04/13/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...CAE...JAX...FFC... LAT...LON 33318518 33068443 32918368 33028245 32958180 32468126 31608210 32078301 32048391 32358480 32838514 33318518 Read more

SPC Apr 13, 2023 2000 UTC Day 1 Convective Outlook

2 years 3 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Apr 13 2023 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN ALABAMA...SOUTHERN AND WESTERN GEORGIA...AND NORTHERN AND EASTERN FLORIDA... ...SUMMARY... A few tornadoes, along with damaging gusts and isolated large hail, will continue this afternoon and into this evening across parts of the Southeast. A severe gust or two may also occur this afternoon over the central High Plains. ...Discussion... Along with line adjustments to account for recent convective evolution, the enhanced risk/10% tornado outlook area is being removed, as convection nears northern and eastern fringes of the existing risk area. Otherwise, isolated but all-hazard severe risk will continue over the next few hours across the southeastern U.S. area, with risk tapering/moving offshore during the early evening. An isolated/late afternoon or early evening wind gust or two near or exceeding severe levels may also occur, as widely scattered convection develops across the High Plains. ..Goss.. 04/13/2023 .PREV DISCUSSION... /ISSUED 1104 AM CDT Thu Apr 13 2023/ ...Southeast... An upper low over the Lower MS Valley will slowly drift east/northeast through the period. This will maintain southeasterly low-level flow across much of FL/GA and vicinity. A dry slot wrapping around the mid/upper low noted over the northern Gulf and nosing into the FL Panhandle/southern GA late this morning is expected to continue spreading northward through the day. Forecast guidance varies considerably with regard to midlevel moisture and amount of low/midlevel mixing across parts of AL/GA. Given current water vapor imagery, it appears drying across AL seems reasonable with more uncertainty with eastward extent across GA. Further east, southeasterly flow should maintain better boundary-layer moisture compared to further west. Surface dewpoints across northern FL are noted in the mid 60s to near 70 F as of 15z, and surface dewpoints have increased around 4 F over the past 3 hours across southern GA. Continual warm/moist advection into southern GA should result in a zone of quality boundary-layer moisture amid modest vertical shear in the vicinity of a quasi-warm front/confluence zone across southern GA. This area may see greater potential for a few tornadoes through this afternoon. Additionally, supercell wind profiles combined with steep low-level lapse rates amid pockets of stronger heating also will support damaging gusts from parts of AL/GA southward along the eastern coast of FL. Isolated large hail also will be possible with cellular convection across parts of AL/GA, and along the northeast/east-central FL coast. ...High Plains... Isolated to widely scattered thunderstorms are expected to develop this afternoon near the lee trough, in a zone of favorable heating and low-level convergence. Modest boundary-layer moisture (surface dewpoints in the 40s F) with steep low/middle-level lapse rates will support modest destabilization. The main concern will be locally strong to severe downdrafts accelerating through the well-mixed subcloud layer. Low-level stabilization should reduce the convective/severe potential with time during early evening. Read more

SPC MD 509

2 years 3 months ago
MD 0509 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN FLORIDA ATLANTIC COASTAL AREAS
Mesoscale Discussion 0509 NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Apr 13 2023 Areas affected...southern Florida Atlantic coastal areas Concerning...Severe potential...Watch unlikely Valid 131944Z - 132215Z Probability of Watch Issuance...20 percent SUMMARY...A couple of storms may intensify further and pose a risk for severe hail and wind through 5-7 PM EDT. Due to the anticipated sparse coverage of this threat, a severe weather watch may not be needed. But trends will continue to be monitored. DISCUSSION...Scattered thunderstorm development is well underway, with initiation ongoing near the Atlantic coast, mainly north of Miami, as well as across interior southern Florida, along the inland advancing sea-breeze from the Gulf of Mexico. This is occurring in the presence of sufficiently strong deep-layer shear (beneath 30 kt flow around 500 mb) for supercell structures, and sizable boundary-layer CAPE supported by insolation and dew points above 70F. While it appears that at least one or two of these storms could pose a risk for severe hail and wind during the next few hours, model output is suggestive that somewhat weaker mid/upper support for ascent relative to northern Florida Atlantic coastal areas may maintain a more isolated severe weather threat. ..Kerr/Leitman.. 04/13/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB... LAT...LON 28198066 27828024 26707998 25808016 25738074 26478087 27008074 28198066 Read more

SPC Tornado Watch 133 Status Reports

2 years 3 months ago
WW 0133 Status Updates
STATUS REPORT ON WW 133 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 W MGR TO 30 WSW ABY. REMAINING VALID PORTION OF WW MAY BE ALLOWED TO EXPIRE AT 13/18Z. ..KERR..04/13/23 ATTN...WFO...TAE...MOB... STATUS REPORT FOR WT 133 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC065-079-123-131800- FL . FLORIDA COUNTIES INCLUDED ARE JEFFERSON MADISON TAYLOR GAC007-027-071-185-205-275-131800- GA . GEORGIA COUNTIES INCLUDED ARE BAKER BROOKS COLQUITT LOWNDES MITCHELL THOMAS THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

SPC Apr 13, 2023 1730 UTC Day 2 Convective Outlook

2 years 3 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Apr 13 2023 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms capable of producing very large hail, and possibly a few damaging gusts, appear most likely to occur across portions of southeast Nebraska and into eastern Kansas Friday. ...Synopsis... While a weakening upper low shifts northeastward out of the Tennessee Valley, a larger trough will advance gradually eastward across the Intermountain West through the period. At the surface, the primary feature will be a cold front -- associated with the western upper trough -- which is forecast to make eastward/southeastward progress across the Plains through the period. ...Central Plains... While lack of moisture beneath an elevated mixed layer will allow rather stout capping to persist through much of the afternoon, a couple of storms may initiate near the advancing cold front by late in the day. Given amply strong/veering flow, in tandem with the steep lapse rates aloft, very large hail would be possible, along with a locally damaging gust or two. While storms may try to grow upscale locally, capping should tend to hinder robust/warm sector MCS development. To the cool side of the front, storms should increase across Kansas and Nebraska into the evening, as a southerly low-level jet develops. With these elevated storms, large hail will be a primary concern into the overnight hours. ...Southern Plains... In part due to modest boundary-layer moisture, a capping inversion at the base of an elevated mixed-layer will hinder afternoon convective development in most areas. A weak mid-level perturbation on the southeastern fringe of the advancing western U.S. trough may aid in a few local breaches of the cap -- with portions of eastern North Texas one area where a couple of cells may briefly develop. Any storm which could organize, would be capable of producing large hail and locally gusty winds. However, will maintain only low/conditional risk due to the strength of capping expected. ...The Carolinas vicinity... As a weakening upper low shifts northeastward out of the Tennessee Valley toward the central Appalachians, early-day convection is forecast to spread northeastward across the Carolinas and Mid-Atlantic region. In the wake of these storms, some diurnal heating to occur, beneath steepening lapse rates aloft associated with the upper system. This should lead to a regeneration of showers and scattered thunderstorms with a noted diurnal peak in coverage/intensity. While shear should remain somewhat limited, in terms of potential for well-organized storms, a few stronger multicell-type clusters may produce marginal hail, and wind gusts locally capable of tree damage. Risk should diminish through the evening hours. ..Goss.. 04/13/2023 Read more

SPC Day 2 Fire Weather Outlook

2 years 3 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Thu Apr 13 2023 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN HIGH PLAINS INTO NORTHWEST TEXAS... ...Southern High Plains... The previous forecast remains on track with only minor adjustments needed based on recent trends in hi-res ensemble guidance. See the previous discussion for additional details. ...Midwest... Periodic elevated conditions appear plausible for portions of northeast IA, southeast MN and WI tomorrow afternoon. While larger fuels remain only modestly dry per recent fuel analyses, fine fuels are likely receptive after multiple days of warm/dry weather. Winds will likely increase to 15 mph ahead of an approaching cold front, and some areas may see RH reductions to near 25%. Transient elevated conditions appear probable, but confidence in coverage/duration remains too limited for additional highlights at this time. ..Moore.. 04/13/2023 .PREV DISCUSSION... /ISSUED 0142 AM CDT Thu Apr 13 2023/ ...Synopsis... The mid-level jet will overspread southern New Mexico into West Texas on Friday. Trends in model guidance have been for the jet to be less intense the past few model cycles. However, a deep surface cyclone and strong low-level pressure gradients will still drive critical fire weather concerns within the southern High Plains. Confidence in critical fire weather is highest underneath the core of the mid-level jet within the Permian Basin into the South Plains. Still, strong winds will exist farther north into the Texas Panhandle as well. The latest fuel guidance from TICC shows ERCs nearing the 90th percentile in the Panhandle. While there is some potential for isolated thunderstorms on Thursday, the impacts should remain minimal and localized. As such, critical fire weather is anticipated in much of the Texas Panhandle. RH of near 10% to 15% will occur over a relatively broad area west of the dryline. Winds of 20-25 mph (with higher gusts) will also be common. The fire weather threat will be bounded by the dryline to the east and a southward-advancing cold front to the north. Winds will quickly change to northerly behind the cold front. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Apr 12, 2023 2000 UTC Day 1 Convective Outlook

2 years 3 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Wed Apr 12 2023 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG PORTIONS OF THE CENTRAL GULF COAST.... ...SUMMARY... Isolated damaging wind gusts and/or a tornado are possible along parts of the Gulf Coast late tonight into Thursday morning. ...20z Update... ...Southern FL Peninsula and Keys... A few stronger storms have been noted moving onshore over the far southern FL Peninsula and Keys this afternoon. Backed low-level flow along a northward moving warm front may support a low-end risk for transient supercells and a brief tornado through the afternoon. However, uncertainty on the coverage and longevity of any severe threat remains too high to introduce severe probabilities. Please see mesoscale discussion 504 for more information. Otherwise, no major changes have been made to the current outlook. Please see the previous discussion for additional details. ..Lyons/Dean.. 04/12/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Wed Apr 12 2023/ ...Gulf Coast including southern portions MS/AL and FL Panhandle... With the mid-level portion of the cyclone centered along the southwest Louisiana coast this morning, the low-level circulation is expected to intensify and shift northward and reach coastal southeast Mississippi/far southwest Alabama vicinity by Thursday morning. However, it is noted that there are several-MB differences, even in the short term, with the progged deepening of the surface low and its northeast-peripheral strengthening wind field among model guidance (e.g. 12z NAM one of the more aggressive solutions). Even more modest-strength/slower solutions suggest that the near-coastal environment could become conducive to some severe-weather potential late tonight into Thursday, including locally damaging winds and a tornado risk. This will be as an increasingly moist air mass via a northward-shifting warm front approaches and moves inland. Mid-level winds will remain modest-strength, but strengthening low-level shear/SRH should be adequate for at least some near-coastal transient supercells, with the potential persisting into Thursday (see Day 2). Read more

Depletion warning on aquifer in Gillespie County, Texas

2 years 3 months ago
The new well permit moratorium in the Hill Country Underground Water Conservation District was allowed to expire April 6. The moratorium took effect on July 12, 2022. The district gave a warning for “critical depletion” of the Ellenberger Aquifer, a large component of the county’s water supply. The well moratorium included irrigation, municipal and commercial purposes within Gillespie County. It had been renewed in 90-day increments since last summer as rainfall to replenish the aquifer has been scarce. Fredericksburg Standard (Texas), April 12, 2023

SPC Day 2 Fire Weather Outlook

2 years 3 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0108 PM CDT Wed Apr 12 2023 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO TO SOUTHWEST NEBRASKA... The expected synoptic evolution remains on track per latest guidance, but a nearly-uniform increase in wind magnitudes is noted across the central Plains in most model solutions, indicative of a trend towards a stronger lee cyclone and stronger 925-850 mb flow than previously depicted. Consequently, confidence in widespread 15-25 mph winds has increased from the southern High Plains to parts of the upper MS River Valley. Diurnal RH reductions to 20-25% remain likely through the Plains/Midwest with 10-20% likely across the southern High Plains behind a sharpening dryline. Both the Elevated and Critical risk areas have been expanded to account for these trends. One complicating factor is the potential for strong to severe thunderstorms along the dryline from southwest NE to west TX during the late afternoon. High-based thunderstorms will pose a risk for strong to severe winds as well as a few dry lightning strikes given PWAT values generally around 0.6 inches or lower. Storm coverage remains uncertain, but the potential for lightning ignitions within a hot, dry, windy environment is noted across parts of the western Plains. ..Moore.. 04/12/2023 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Apr 12 2023/ ...Synopsis... A broad upper trough will move through the Four Corners on Thursday and eject into the southern Plains around Friday morning. A strong low-pressure system in the central High Plains will continue to deepen and shift southeastward through the period. Strong surface winds are possible from the southern Plains into parts of the Midwest ahead of a cold front moving southward through the northern Plains. ...Southern High Plains into southeast Colorado... Surface winds of 15-25 mph appear possible from the foothills of the southern Rockies eastward to the surface trough/dryline. Several models indicate that RH could fall to 10-15% across the region. These meteorological factors will combine with drought-stressed fine fuels to promote critical fire weather conditions within a fairly narrow corridor east of the higher terrain. ...Central Plains into the Midwest... The surface pattern will be similar to Wednesday, though winds will likely be stronger. The driest conditions are most probable along the Foothills of Colorado into western portions of Kansas/Nebraska. There, RH of 15-20% with can be expected. Farther north and east into Iowa, RH of 20-25% appears possible. Some guidance shows at least local values in the teens. Winds across the central Plains/Midwest will be aided by enhanced 850 mb winds during the day. Fuels within the Foothills and Iowa do not appear to be critically dry. Impacts from drought have dried fuels in western Kansas into parts of Nebraska, but potential convection along the dryline may limit the duration of critical fire weather. Elevated fire weather is expected with locally critical fire weather remaining possible. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Apr 12, 2023 1730 UTC Day 2 Convective Outlook

2 years 3 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1216 PM CDT Wed Apr 12 2023 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS AND INTO PORTIONS OF THE SOUTHEAST.... ...SUMMARY... Isolated severe thunderstorms are possible across portions of the southern and central High Plains and portions of the Southeast States/Florida on Thursday. ...Synopsis... A mid-level closed low over the Gulf of Mexico is forecast to continue to slowly meander eastward while the associated surface circulation moves onshore early Thursday. Scattered strong thunderstorms should move inland early, and persist through much of the day. To the west, a mid-level trough digging over the central Rockies and northern Great Basin will shift eastward overspreading the central High Plains. A strong lee low is forecast to evolve aiding in the development of a dryline and weak moisture return over the western High Plains. Isolated severe thunderstorms are possible in the afternoon and evening ahead of the sharpening dryline. ...Southeastern States... As the closed low shifts northeastward across the central Gulf Coast, rapid low-level moistening is expected in its eastern quadrant early in the forecast period. Mid, to eventually upper, 60s F surface dewpoints will surge inland over portions of eastern MS/AL, into southern GA and much of FL by midday. Weak mid-level warm advection and a mostly uncapped surface warm sector should allow for loosely organized bands of scattered thunderstorms to move onshore and develop through much of the day. Limited by mostly cloudy skies, afternoon destabilization is not expected to be overly strong, but diffuse heating and returning surface moisture should be sufficient to support scattered thunderstorms and occasional stronger updrafts. Mid-level shear is also not particularly strong owing the weaker flow aloft on the eastern periphery of the upper-level circulation. However, enhanced easterly flow in the low to mid-levels supports some hodograph curvature/expansion in the lowest few kilometers. Given the favorable storm relative flow and larger SRH (200 m2/s2), transient supercell structures may evolve with the more persistent updrafts. The strongest storms may pose a risk for damaging wind gusts and a tornado or two into the early evening. A few storms may also be capable of marginally severe hail given cooler temperatures aloft. ...Central and southern High Plains... As the western US trough continues to deepen and shift eastward through the day, broad-scale ascent and an embedded shortwave trough will overspread a sharpening dryline/lee trough extending south from a lee low over western NE. Strong diurnal heating and mixing along the dryline will remove limited inhibition concurrent with northward returning surface moisture. While not excessively moist, surface dewpoints reaching the upper 30s to mid 40s F should be adequate for weak afternoon destabilization given the very warm temperatures and steep lapse rates. The warm temperatures and marginal moisture should support around 500 J/kg of MLCAPE allowing the development of isolated high-based storms late in the afternoon. Steepening low-level lapse rates will favor strong downdrafts and severe wind gust potential with any convection able to develop. The greatest converge of storms is currently expected over portions of the TX Panhandle into southwestern KS where deeper surface moisture and locally stronger surface convergence are expected along the dryline. Given the limited surface moisture, storms should diminish quickly after sunset with the loss of diurnal heating. A Marginal Risk area has been added from central NE to the southern TX Panhandle mainly for isolated damaging wind gusts. ..Lyons/Dean.. 04/12/2023 Read more

SPC Apr 12, 2023 1630 UTC Day 1 Convective Outlook

2 years 3 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Apr 12 2023 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE GULF COAST... ...SUMMARY... Isolated damaging wind gusts and/or a tornado are possible along parts of the Gulf Coast late tonight into Thursday morning. ...Gulf Coast including southern portions MS/AL and FL Panhandle... With the mid-level portion of the cyclone centered along the southwest Louisiana coast this morning, the low-level circulation is expected to intensify and shift northward and reach coastal southeast Mississippi/far southwest Alabama vicinity by Thursday morning. However, it is noted that there are several-MB differences, even in the short term, with the progged deepening of the surface low and its northeast-peripheral strengthening wind field among model guidance (e.g. 12z NAM one of the more aggressive solutions). Even more modest-strength/slower solutions suggest that the near-coastal environment could become conducive to some severe-weather potential late tonight into Thursday, including locally damaging winds and a tornado risk. This will be as an increasingly moist air mass via a northward-shifting warm front approaches and moves inland. Mid-level winds will remain modest-strength, but strengthening low-level shear/SRH should be adequate for at least some near-coastal transient supercells, with the potential persisting into Thursday (see Day 2). ..Guyer/Weinman.. 04/12/2023 Read more

SPC Apr 11, 2023 2000 UTC Day 1 Convective Outlook

2 years 3 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Tue Apr 11 2023 Valid 112000Z - 121200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected over the U.S. today and tonight. ...20z Update... No major changes have been made to the outlook. A few areas of general thunderstorms remain possible over the Lower 48 through this evening, but severe weather is not expected. Please see the previous discussion for more information. ..Lyons/Dean.. 04/11/2023 .PREV DISCUSSION... /ISSUED 1118 AM CDT Tue Apr 11 2023/ ...Synopsis/Discussion... A midlevel trough will continue slowly eastward over the Northwest today/tonight, providing enough lift (aided by orographic effects) to support isolated lightning flashes across the Pacific Northwest this afternoon/evening given steepening lapse rates and adequate buoyancy. Farther east, a positively tilted mid/upper-level trough will drift south/southeastward over the lower MS Valley vicinity into the northwestern Gulf of Mexico, becoming a closed upper low late in the period. Several embedded lobes of ascent (evident in water-vapor imagery) rotating around this feature, combined with filtered diurnal heating of a partially modified gulf air mass, will favor isolated to widely scattered thunderstorms over southern LA and parts of south TX. Over southern FL and the Keys, enhanced low-level easterlies and deep boundary-layer moisture along/north of a remnant frontal boundary will support periodic bands of convection, with the greater lightning potential expected over the FL Straits and spreading northward late in the period. Marginal buoyancy and weak deep-layer shear should generally limit convective intensity/organization across the CONUS, though a loosely organized storm or two cannot be entirely ruled out near the FL Keys. Read more

SPC Day 2 Fire Weather Outlook

2 years 3 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0236 PM CDT Tue Apr 11 2023 Valid 121200Z - 131200Z ...High Plains to central Plains... Latest guidance continues to show reasonably high confidence in widespread elevated conditions from the greater Panhandles region into the central Plains as gradient winds increase by mid-day. Localized critical conditions appear possible across parts of western KS into southwest NE, but confidence in the overlap of the strongest winds (over central KS/NE) with the drier air mass (over eastern CO/western NE) remains limited per latest ensemble guidance and deterministic RAP runs. The coverage of elevated conditions is likely under-done in most model solutions given the recent cool/moist bias over the past several days. Consequently, the risk area has been expanded based on recent RAP solutions (which have been handling boundary-layer mixing the best out of any guidance). ...Midwest... The Elevated risk area has been expanded eastward into portions of southern WI/northern IL. Recent RAP forecasts suggests afternoon RH values in the mid to upper 20s are probable across eastern IA into southern WI/northern IL. Gradient winds near 20 mph appear likely, and should support elevated fire weather conditions where RH criteria are met. 10+ hour fuels across this region appear to be unreceptive based on recent fuel moisture analyses and drought indices, but fuel reports from local offices/fire agencies indicate that fine (1-hour) fuels are sufficiently dry to support a fire weather concern. ...Northeast... Gradient winds on the northeast periphery of the southern surface high are expected to strengthen to near 15 mph with gusts approaching 20 mph. While winds may be stronger/more widespread on Wednesday as compared to today/Tuesday, RH is forecast to be slightly higher with minimums near 25-35% based on latest RAP forecasts. Confidence in the spatial extent and coverage of the fire weather threat is uncertain, but localized elevated conditions appear probable across parts of the Mid-Atlantic to New England region. ..Moore.. 04/11/2023 .PREV DISCUSSION... /ISSUED 0225 AM CDT Tue Apr 11 2023/ ...Synopsis... A Rex block will setup across the Mississippi Valley region on Wednesday. The strong trough in the Northwest will continue to slowly move eastward. A similar surface pattern to Tuesday is expected with a slightly deeper lee trough in the High Plains along with a weakened, but still stout, Southeast surface high. ...Parts of southern High Plains and central Plains... With a stronger lee trough, similarly dry and windy conditions are possible again across much of the same areas as Tuesday. Winds in parts of Kansas into Nebraska may be stronger, but some additional moisture return may slightly increase RH values during the afternoon. Winds of 15-20 mph are more likely near the southern High Plains, increasing to perhaps 20+ mph into eastern Nebraska/western Iowa. RH 10-20% will exist in the High Plains with values closer to 20-25% farther north and east. Given the dry fuels in the region and similar conditions to Tuesday, elevated fire weather is again expected. ...Parts of Upper Midwest... Locally dry and windy conditions are possible as the pressure gradient strengthens across the region. Dry southwesterly winds may lead to RH around 20-25% as temperatures warm into the afternoon. Winds are expected to be strongest in the morning appear to be mostly out of phase with the lowest RH. Fire weather conditions will be elevated on a local basis, where fuels are dry, however. ...Please see www.spc.noaa.gov/fire for graphic product... Read more