SPC MD 670

2 years 2 months ago
MD 0670 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF WESTERN NORTH TX
Mesoscale Discussion 0670 NWS Storm Prediction Center Norman OK 0154 PM CDT Wed May 03 2023 Areas affected...Portions of western north TX Concerning...Severe potential...Watch unlikely Valid 031854Z - 032130Z Probability of Watch Issuance...5 percent SUMMARY...An isolated hail/wind risk may exist with developing thunderstorms this afternoon. Watch issuance is not expected. DISCUSSION...The cu field has recently become agitated along an outflow-reinforced front across western north TX. Latest visible and day cloud phase satellite imagery suggest at least one thunderstorm may develop and persist along this boundary. The low/mid-level flow field remains modest across this region per recent area VWPs, but enough veering/strengthening with height may still support 25-35 kt of deep-layer shear. This should be sufficient for some updraft organization, including marginal supercell potential. If a robust thunderstorm can form and persist, it would tend to move slowly east-southeastward along/near the surface boundary. Around 1000-1500 J/kg of MLCAPE and somewhat steepened mid-level lapse rates should support some threat for isolated large hail. Occasional severe/damaging downdraft winds may also occur as low-level lapse rates continue to steepen. Current expectations are for the severe threat to remain quite isolated, so watch issuance is not currently expected. ..Gleason/Thompson.. 05/03/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...SJT... LAT...LON 32609969 32820000 33229992 33329953 33189863 32779850 32519900 32609969 Read more

Stage 1 drought contingency water conservation in Clyde, Texas

2 years 2 months ago
Clyde was in a stage 1 drought contingency water conservation notice as the level of Clyde Lake continued to fall. Water customers were encouraged to reduce their water use by 10%. The level was 10 feet, 2 inches below the spillway, making it less than 50% full. Motorized boats may not be used on the lake any longer, due to the shallow water level. Clyde Lake is the main supplier for Callahan County. Because the lake is low, the City of Clyde will leave the splash pad off to conserve water. KTAB TV 32 & KRBC TV 9 (Abilene, Texas), May 3, 2023

Lower pressure to conserve reclaimed water in St. Petersburg, Florida

2 years 2 months ago
The city of St. Petersburg lowered its reclaimed water pressure flow during the heat of the day to conserve water. Residents would still have enough water for irrigating during the night and early morning when the water pressure is normal. Lawn watering is permitted three times weekly during certain hours. April and May are the months when reclaimed water demand is at its highest while supply is lowest. Tampa Bay Times (Fla.), May 2, 2023

SPC May 3, 2023 1730 UTC Day 2 Convective Outlook

2 years 2 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1216 PM CDT Wed May 03 2023 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Severe thunderstorms capable of large hail, strong/damaging wind gusts, and a couple of tornadoes are possible across parts of the southern Great Plains Thursday afternoon and evening. ...TX/OK/KS... The upper ridge centered over the central/southern Plains will de-amplify on Wednesday as a series of shortwave impulses migrate through west/southwesterly flow. in response to modest height falls, a weak surface low is expected to develop over the western KS vicinity. A dryline will extend southward from the low across western OK into west-central TX. The day will begin with modest boundary-layer moisture across north TX into OK/KS. However, southerly low-level flow will transport a somewhat narrow corridor of low 60s F dewpoints northward across OK/KS through early evening. Deeper boundary-layer moisture will reside further south across central/southern TX where mid/upper 60s F dewpoints are expected. Uncertainty in convective initiation/evolution remains, especially from north TX into KS. A few scenarios are possible, with one point of uncertainty being potentially early ejection of a lead shortwave impulse around midday. If convection develops early in the afternoon, tied to the early shortwave impulse, elevated storms will be more likely. However, some guidance suggests decaying overnight convection and morning cloudiness over OK and vicinity could suppress early CI from the lead shortwave impulse. If this occurs, there may be better potential for late afternoon surface-based convection along the dryline in OK/southern KS. While this leads to a more uncertain/conditional forecast, a moist boundary-layer beneath steep lapse rates will support moderate destabilization. Furthermore, the nose of the midlevel jet will overspread the region during the afternoon and vertically veering profiles will result in 40+ kt effective shear. Supercells will a risk of large hail and strong gusts will be possible. If surface-based afternoon storms develop near the dryline bulge across northwest OK into south-central KS, backed low-level winds and effective SRH increasing to around 250 m2/s2 will support potential for a couple of tornadoes. Further south along the dryline in central TX, strong heating and mid/upper 60s F dewpoints will support MLCAPE values to around 2000-3000 J/kg by afternoon. Low to mid-level flow will be somewhat weak, but rapidly increase with height above 700 mb. Sufficient veering with height also will contribute to effective shear values greater than 40 kt. Supercells capable of large hail (some greater than 2 inches in diameter) will be possible. Given steep low-level lapse rates to around 850 mb and weak low-level winds, strong outflow and storm interactions may support some upward development into forward-propagating clusters by early evening. Damaging gusts in addition to large hail will be possible with this activity. ...Nebraska vicinity... Boundary-layer moisture will remain modest with northward extent into NE. However, steep midlevel lapse rates will support modest destabilization as temperatures warm to near 80 F ahead of a southward-progressing cold front. Modest deep-layer flow will limit longevity/better-organized updrafts, but marginally severe hail and strong gusts will be possible with more intense convection. ...Great Basin/Northwest... Scattered thunderstorms are expected in increasing southwesterly flow on the eastern periphery of the CA/NV upper low, and in the easterly flow regime on the north side of the low across ID toward the Cascades. Limited moisture and a deeply-mixed boundary-layer will result in high-based convection. Steep lapse rates will aid in modest destabilization with gusty winds and small hail possible. ..Leitman.. 05/03/2023 Read more

SPC May 3, 2023 1730 UTC Day 2 Convective Outlook

2 years 2 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1216 PM CDT Wed May 03 2023 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Severe thunderstorms capable of large hail, strong/damaging wind gusts, and a couple of tornadoes are possible across parts of the southern Great Plains Thursday afternoon and evening. ...TX/OK/KS... The upper ridge centered over the central/southern Plains will de-amplify on Wednesday as a series of shortwave impulses migrate through west/southwesterly flow. in response to modest height falls, a weak surface low is expected to develop over the western KS vicinity. A dryline will extend southward from the low across western OK into west-central TX. The day will begin with modest boundary-layer moisture across north TX into OK/KS. However, southerly low-level flow will transport a somewhat narrow corridor of low 60s F dewpoints northward across OK/KS through early evening. Deeper boundary-layer moisture will reside further south across central/southern TX where mid/upper 60s F dewpoints are expected. Uncertainty in convective initiation/evolution remains, especially from north TX into KS. A few scenarios are possible, with one point of uncertainty being potentially early ejection of a lead shortwave impulse around midday. If convection develops early in the afternoon, tied to the early shortwave impulse, elevated storms will be more likely. However, some guidance suggests decaying overnight convection and morning cloudiness over OK and vicinity could suppress early CI from the lead shortwave impulse. If this occurs, there may be better potential for late afternoon surface-based convection along the dryline in OK/southern KS. While this leads to a more uncertain/conditional forecast, a moist boundary-layer beneath steep lapse rates will support moderate destabilization. Furthermore, the nose of the midlevel jet will overspread the region during the afternoon and vertically veering profiles will result in 40+ kt effective shear. Supercells will a risk of large hail and strong gusts will be possible. If surface-based afternoon storms develop near the dryline bulge across northwest OK into south-central KS, backed low-level winds and effective SRH increasing to around 250 m2/s2 will support potential for a couple of tornadoes. Further south along the dryline in central TX, strong heating and mid/upper 60s F dewpoints will support MLCAPE values to around 2000-3000 J/kg by afternoon. Low to mid-level flow will be somewhat weak, but rapidly increase with height above 700 mb. Sufficient veering with height also will contribute to effective shear values greater than 40 kt. Supercells capable of large hail (some greater than 2 inches in diameter) will be possible. Given steep low-level lapse rates to around 850 mb and weak low-level winds, strong outflow and storm interactions may support some upward development into forward-propagating clusters by early evening. Damaging gusts in addition to large hail will be possible with this activity. ...Nebraska vicinity... Boundary-layer moisture will remain modest with northward extent into NE. However, steep midlevel lapse rates will support modest destabilization as temperatures warm to near 80 F ahead of a southward-progressing cold front. Modest deep-layer flow will limit longevity/better-organized updrafts, but marginally severe hail and strong gusts will be possible with more intense convection. ...Great Basin/Northwest... Scattered thunderstorms are expected in increasing southwesterly flow on the eastern periphery of the CA/NV upper low, and in the easterly flow regime on the north side of the low across ID toward the Cascades. Limited moisture and a deeply-mixed boundary-layer will result in high-based convection. Steep lapse rates will aid in modest destabilization with gusty winds and small hail possible. ..Leitman.. 05/03/2023 Read more

Sprinkler use limited in Pinellas County, Florida

2 years 2 months ago
Water customers in northern Pinellas County must limit sprinkler use as the drought affecting the Tampa Bay area worsens. The county utilities department announced that outdoor watering may be done just once weekly, rather than thrice. The reclaimed water in storage has been used as demand for it has been higher due to low rainfall. Fines for violating the water restrictions begin at $193. Tampa Bay Times (Fla.), April 21, 2023

SPC MD 668

2 years 2 months ago
MD 0668 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF FAR SOUTHEASTERN NM INTO WEST TX
Mesoscale Discussion 0668 NWS Storm Prediction Center Norman OK 0330 PM CDT Tue May 02 2023 Areas affected...Portions of far southeastern NM into west TX Concerning...Severe potential...Watch possible Valid 022030Z - 022300Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorms may gradually increase in coverage and intensity this afternoon, with both severe winds and hail possible. Trends will be monitored for possible watch issuance. DISCUSSION...Convection has been slowly increasing along and just east of the Sacramento/Guadalupe Mountains in southern NM and the Davis Mountains in west TX. This is occurring as a weak shortwave trough moves over this region, and modest low-level upslope flow continues. The current activity is rather high based, given the presence of generally 30s surface dewpoints and a very well mixed boundary layer where surface heating has occurred. As this convection spreads east-northeastward over the next couple of hours, these thunderstorms will gradually intercept modestly greater low-level moisture characterized by mid 40s to mid 50s surface dewpoints present across far eastern NM into west TX. Some intensification of this convection may occur as it intercepts the greater instability across west TX. Still, deep-layer shear remains rather modest, around 20-30 kt, due to the low-amplitude nature of the shortwave trough and weak low-level mass response. Multicell clusters will probably be the dominant mode with any convection that can persist with eastward extent. Given the steep low/mid-level lapse rates and inverted-v type soundings, severe wind gusts should be the main threat, but some hail may also occur with the more robust updrafts. Overall convective organization and intensity may remain somewhat marginal/isolated late this afternoon and evening, and the need for a watch is unclear. Regardless, observational trends will be closely monitored. ..Gleason/Thompson.. 05/02/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LUB...MAF...ABQ... LAT...LON 31300293 31580328 32020350 33770349 34260324 34350275 34330219 34090186 33710174 33110166 32060169 31480212 31280249 31300293 Read more

SPC Day 2 Fire Weather Outlook

2 years 2 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Tue May 02 2023 Valid 031200Z - 041200Z The current Day 2 Fire Weather Outlook is on track with no changes needed. See previous discussion below. ..Thornton.. 05/02/2023 .PREV DISCUSSION... /ISSUED 0216 AM CDT Tue May 02 2023/ ...Synopsis... Fire weather concerns will primarily be focused across the Southwest on Wednesday. A sub-tropical shortwave trough is forecast to migrate out of northern Mexico into the Southwest through the day. This will lead to broad, but modest, pressure falls across the Four Corners and southern High Plains. In response, southerly winds are forecast to increase to 15-20 mph from the international border into the Four Corners and eastern Great Basin. Downslope warming and drying will support areas of 15-20% RH coincident with breezy winds. Elevated fire weather conditions are possible across much of the region, but the fire concern will be focused primarily across southeast AZ into southwest and central NM where ERCs have reached the 80-90th percentile amid a prolonged (30-day) period of negligible rainfall. ...Georgia into South Carolina... Another day of dry and breezy weather is expected as a Great Lakes low continues to meander northeast. Gradient winds will likely be weaker compared to today (Tuesday), but most solutions hint at winds near 15 mph during peak heating when RH values will likely be around 25-30%. Elevated fire weather conditions are possible, but the overall fire threat will be conditional on fuel status by Wednesday afternoon. Widespread drying/curing of fine fuels is expected today, and may be sufficient for highlights in subsequent updates. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

2 years 2 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Tue May 02 2023 Valid 031200Z - 041200Z The current Day 2 Fire Weather Outlook is on track with no changes needed. See previous discussion below. ..Thornton.. 05/02/2023 .PREV DISCUSSION... /ISSUED 0216 AM CDT Tue May 02 2023/ ...Synopsis... Fire weather concerns will primarily be focused across the Southwest on Wednesday. A sub-tropical shortwave trough is forecast to migrate out of northern Mexico into the Southwest through the day. This will lead to broad, but modest, pressure falls across the Four Corners and southern High Plains. In response, southerly winds are forecast to increase to 15-20 mph from the international border into the Four Corners and eastern Great Basin. Downslope warming and drying will support areas of 15-20% RH coincident with breezy winds. Elevated fire weather conditions are possible across much of the region, but the fire concern will be focused primarily across southeast AZ into southwest and central NM where ERCs have reached the 80-90th percentile amid a prolonged (30-day) period of negligible rainfall. ...Georgia into South Carolina... Another day of dry and breezy weather is expected as a Great Lakes low continues to meander northeast. Gradient winds will likely be weaker compared to today (Tuesday), but most solutions hint at winds near 15 mph during peak heating when RH values will likely be around 25-30%. Elevated fire weather conditions are possible, but the overall fire threat will be conditional on fuel status by Wednesday afternoon. Widespread drying/curing of fine fuels is expected today, and may be sufficient for highlights in subsequent updates. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC May 2, 2023 2000 UTC Day 1 Convective Outlook

2 years 2 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Tue May 02 2023 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTHEAST NEW MEXICO AND WEST-CENTRAL TEXAS... ...SUMMARY... A few severe thunderstorm gusts and isolated large hail will be possible through evening across eastern New Mexico and west Texas. ...Southern High Plains... Aside from minor changes to the 10 percent general thunder line, no changes have been made to the ongoing outlook with the 20z update. Isolated thunderstorms are developing near the higher terrain of southwest TX into southern NM as of 1930z. This activity is developing within a drier, weakly unstable airmass. However, as convection shifts east toward modestly better moisture/instability, increasing potential for severe wind/hail is expected through evening. ..Leitman.. 05/02/2023 .PREV DISCUSSION... /ISSUED 1127 AM CDT Tue May 02 2023/ ...Southern High Plains this afternoon/evening... The persistent omega block persists over the CONUS, with a deep low over the Great Lakes/Northeast, a ridge over the Rockies, and another midlevel low over northern CA. A plume of midlevel moisture extends from the northern CA low southeastward toward west TX, within the deformation zone between the two deep lows. Subtle speed maxima are moving northeastward from northern Mexico toward the southern High Plains, as low-level moisture gradually increases from the southeast (in response to weak lee troughing). In the immediate wake of morning clouds, strong surface heating and modest increases in low-level moisture will contribute to destabilization this afternoon, when MLCAPE will approach 1000 J/kg. The 12z MAF/EPZ soundings suggest that the warmest elevated mixed layer plume is already over TX, with cooler upstream temperatures. Thus, afternoon surface temperatures into the mid 80s should be sufficient to mix through the base of the elevated mixed layer, reducing convective inhibition and supporting scattered thunderstorm development across eastern NM/west TX along the lee trough. The weak-moderate buoyancy and steep lapse rate profiles, in combination with rather modest deep-layer shear and relatively straight hodographs, will support a mix of multicell clusters and perhaps some splitting supercells. The primary severe threat will be a few severe outflow gusts with the high-based storms, though isolated/marginally severe hail may occur with transient supercell structures and/or favorable storm mergers/interactions. The severe-weather threat will peak late afternoon and slowly diminish by late evening, though slightly elevated storms could persist overnight. Read more

SPC May 2, 2023 2000 UTC Day 1 Convective Outlook

2 years 2 months ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Tue May 02 2023 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTHEAST NEW MEXICO AND WEST-CENTRAL TEXAS... ...SUMMARY... A few severe thunderstorm gusts and isolated large hail will be possible through evening across eastern New Mexico and west Texas. ...Southern High Plains... Aside from minor changes to the 10 percent general thunder line, no changes have been made to the ongoing outlook with the 20z update. Isolated thunderstorms are developing near the higher terrain of southwest TX into southern NM as of 1930z. This activity is developing within a drier, weakly unstable airmass. However, as convection shifts east toward modestly better moisture/instability, increasing potential for severe wind/hail is expected through evening. ..Leitman.. 05/02/2023 .PREV DISCUSSION... /ISSUED 1127 AM CDT Tue May 02 2023/ ...Southern High Plains this afternoon/evening... The persistent omega block persists over the CONUS, with a deep low over the Great Lakes/Northeast, a ridge over the Rockies, and another midlevel low over northern CA. A plume of midlevel moisture extends from the northern CA low southeastward toward west TX, within the deformation zone between the two deep lows. Subtle speed maxima are moving northeastward from northern Mexico toward the southern High Plains, as low-level moisture gradually increases from the southeast (in response to weak lee troughing). In the immediate wake of morning clouds, strong surface heating and modest increases in low-level moisture will contribute to destabilization this afternoon, when MLCAPE will approach 1000 J/kg. The 12z MAF/EPZ soundings suggest that the warmest elevated mixed layer plume is already over TX, with cooler upstream temperatures. Thus, afternoon surface temperatures into the mid 80s should be sufficient to mix through the base of the elevated mixed layer, reducing convective inhibition and supporting scattered thunderstorm development across eastern NM/west TX along the lee trough. The weak-moderate buoyancy and steep lapse rate profiles, in combination with rather modest deep-layer shear and relatively straight hodographs, will support a mix of multicell clusters and perhaps some splitting supercells. The primary severe threat will be a few severe outflow gusts with the high-based storms, though isolated/marginally severe hail may occur with transient supercell structures and/or favorable storm mergers/interactions. The severe-weather threat will peak late afternoon and slowly diminish by late evening, though slightly elevated storms could persist overnight. Read more

SPC May 2, 2023 1730 UTC Day 2 Convective Outlook

2 years 2 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Tue May 02 2023 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST TEXAS TO FAR EASTERN COLORADO AND WESTERN KANSAS... ...SUMMARY... Isolated to widely scattered strong to severe thunderstorms capable of strong gusts and large hail are possible Wednesday afternoon and evening across the central and southern High Plains. ...Southern/Central High Plains... An upper ridge will be centered over the Rockies and adjacent High Plains on Wednesday. Various weak impulses related to remnants of Day 1/Tuesday convection will be shifting east across KS/OK early in the period. Thereafter, forcing for ascent will remain nebulous until late in the period when a shortwave impulse is forecast to eject into the southern Rockies/High Plains vicinity after 03z. This later impulse will be ill-timed for diurnal convection. Modest boundary-layer moisture (surface dewpoints from the mid 50s to low 60s F) is forecast from southwest TX northward through the OK/TX Panhandles and into far eastern CO/western KS. Steep midlevel lapse rates will contribute to MLCAPE values around 1500-2000 J/kg, with much of the instability focused above 700 mb atop a weak EML. Deep-layer flow also will remain fairly weak beneath the upper ridge, though favorable veering with height will be sufficient for effective shear values near 30 kt. Strong heating and low-level convergence should be sufficient to support isolated thunderstorm development by afternoon. Shear will be marginally favorable for transient supercells and clusters. Elongated hodographs above 2-3 km coupled with favorable thermodynamic profiles suggest large hail will be possible with any sustained semi-discrete convection. Steep low-level lapse rates also may support isolated strong downburst winds. Modestly enlarged low-level hodographs and around 100 J/kg 0-3km MLCAPE typically would indicate some potential for a tornado. However, given modest boundary-layer moisture and weak 0-1 km shear, the tornado threat is expected to remain minimal. ...Oregon/Washington... Modest heating/destabilization will again support thunderstorm development across parts of the interior Northwest on Wednesday. Guidance still suggests that a midlevel shortwave trough embedded within the broader cyclonic flow may be favorably timed for storm development during the late afternoon/evening across western/northern OR into southern WA. Some uncertainty regarding low-level moisture, and hence degree of destabilization, is evident in forecast surface dewpoints. The operational NAM remains more aggressive with boundary-layer dewpoints compared to most other guidance. While some low severe potential may develop (mainly for hail), current expectation is for a few strong storms capable of mainly small, sub-severe hail. ..Leitman.. 05/02/2023 Read more

SPC May 2, 2023 1730 UTC Day 2 Convective Outlook

2 years 2 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Tue May 02 2023 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST TEXAS TO FAR EASTERN COLORADO AND WESTERN KANSAS... ...SUMMARY... Isolated to widely scattered strong to severe thunderstorms capable of strong gusts and large hail are possible Wednesday afternoon and evening across the central and southern High Plains. ...Southern/Central High Plains... An upper ridge will be centered over the Rockies and adjacent High Plains on Wednesday. Various weak impulses related to remnants of Day 1/Tuesday convection will be shifting east across KS/OK early in the period. Thereafter, forcing for ascent will remain nebulous until late in the period when a shortwave impulse is forecast to eject into the southern Rockies/High Plains vicinity after 03z. This later impulse will be ill-timed for diurnal convection. Modest boundary-layer moisture (surface dewpoints from the mid 50s to low 60s F) is forecast from southwest TX northward through the OK/TX Panhandles and into far eastern CO/western KS. Steep midlevel lapse rates will contribute to MLCAPE values around 1500-2000 J/kg, with much of the instability focused above 700 mb atop a weak EML. Deep-layer flow also will remain fairly weak beneath the upper ridge, though favorable veering with height will be sufficient for effective shear values near 30 kt. Strong heating and low-level convergence should be sufficient to support isolated thunderstorm development by afternoon. Shear will be marginally favorable for transient supercells and clusters. Elongated hodographs above 2-3 km coupled with favorable thermodynamic profiles suggest large hail will be possible with any sustained semi-discrete convection. Steep low-level lapse rates also may support isolated strong downburst winds. Modestly enlarged low-level hodographs and around 100 J/kg 0-3km MLCAPE typically would indicate some potential for a tornado. However, given modest boundary-layer moisture and weak 0-1 km shear, the tornado threat is expected to remain minimal. ...Oregon/Washington... Modest heating/destabilization will again support thunderstorm development across parts of the interior Northwest on Wednesday. Guidance still suggests that a midlevel shortwave trough embedded within the broader cyclonic flow may be favorably timed for storm development during the late afternoon/evening across western/northern OR into southern WA. Some uncertainty regarding low-level moisture, and hence degree of destabilization, is evident in forecast surface dewpoints. The operational NAM remains more aggressive with boundary-layer dewpoints compared to most other guidance. While some low severe potential may develop (mainly for hail), current expectation is for a few strong storms capable of mainly small, sub-severe hail. ..Leitman.. 05/02/2023 Read more

SPC Day 1 Fire Weather Outlook

2 years 2 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Tue May 02 2023 Valid 021700Z - 031200Z No changes are needed to the current Day 1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 05/02/2023 .PREV DISCUSSION... /ISSUED 0141 AM CDT Tue May 02 2023/ ...Synopsis... ...Minnesota to Iowa... Elevated fire weather concerns are expected this afternoon across parts of Minnesota into northern Iowa. Early-morning satellite and surface observations continue to show a stacked upper and surface low over the lower Great Lakes region. This system will continue to gradually shift east today, but will maintain breezy northerly gradient winds across the upper MS Valley. Previous 24-hour observations across MN show a slight drying trend with dewpoints falling into the low to mid 20s. Recent model solutions have had a slight moist-bias during this period, and continue the slow drying trend into this afternoon. Consequently, afternoon RH values will likely fall below yesterday's observed RH minimums. Gradient winds between 15-25 mph are expected with frequent gusts up to 35 mph. Little rainfall over the past week, coupled with curing from hot, dry, windy conditions yesterday, has allowed ERCs to approach the 90th percentile for some locations. Refinements to the risk area have been made across IA to reflect where local fuel reports indicate spring green up has sufficiently mitigated fuel receptiveness. ...Southeast NM into southwest TX... 00 UTC soundings from MAF and EPZ show steep mid-level lapse rates with dry, well-mixed boundary layers and PWAT values near 0.5 inch. This thermodynamic profile is expected to largely remain in place through the afternoon as ascent associated with an sub-tropical shortwave trough overspreads the region. A few isolated dry thunderstorms are possible over the region where ERC values are in excess of the 80th percentile. Additional thunderstorms are expected in the periphery of the risk area, but latest ensemble guidance suggests the probability of wetting rainfall is higher. ...Georgia into South Carolina... Westerly gradient winds on the southern periphery of the Great Lakes low are forecast to be sustained around 15 mph (gusting to 20-30 mph) from GA eastward to the Carolina coast. A dry continental air mass moving into the region, coupled with diurnal warming, will support RH reductions into the 20-30% range. Elevated to locally critical fire weather conditions appear probable, but widespread rainfall amounts of 0.25-0.5 inch over the past 48-72 hours cast uncertainty onto the coverage of receptive fuels. As such, the fire concern will primarily be focused on local areas where dead grasses and other fine fuels have sufficiently dried over the past 24-48 hours. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

2 years 2 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Tue May 02 2023 Valid 021700Z - 031200Z No changes are needed to the current Day 1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 05/02/2023 .PREV DISCUSSION... /ISSUED 0141 AM CDT Tue May 02 2023/ ...Synopsis... ...Minnesota to Iowa... Elevated fire weather concerns are expected this afternoon across parts of Minnesota into northern Iowa. Early-morning satellite and surface observations continue to show a stacked upper and surface low over the lower Great Lakes region. This system will continue to gradually shift east today, but will maintain breezy northerly gradient winds across the upper MS Valley. Previous 24-hour observations across MN show a slight drying trend with dewpoints falling into the low to mid 20s. Recent model solutions have had a slight moist-bias during this period, and continue the slow drying trend into this afternoon. Consequently, afternoon RH values will likely fall below yesterday's observed RH minimums. Gradient winds between 15-25 mph are expected with frequent gusts up to 35 mph. Little rainfall over the past week, coupled with curing from hot, dry, windy conditions yesterday, has allowed ERCs to approach the 90th percentile for some locations. Refinements to the risk area have been made across IA to reflect where local fuel reports indicate spring green up has sufficiently mitigated fuel receptiveness. ...Southeast NM into southwest TX... 00 UTC soundings from MAF and EPZ show steep mid-level lapse rates with dry, well-mixed boundary layers and PWAT values near 0.5 inch. This thermodynamic profile is expected to largely remain in place through the afternoon as ascent associated with an sub-tropical shortwave trough overspreads the region. A few isolated dry thunderstorms are possible over the region where ERC values are in excess of the 80th percentile. Additional thunderstorms are expected in the periphery of the risk area, but latest ensemble guidance suggests the probability of wetting rainfall is higher. ...Georgia into South Carolina... Westerly gradient winds on the southern periphery of the Great Lakes low are forecast to be sustained around 15 mph (gusting to 20-30 mph) from GA eastward to the Carolina coast. A dry continental air mass moving into the region, coupled with diurnal warming, will support RH reductions into the 20-30% range. Elevated to locally critical fire weather conditions appear probable, but widespread rainfall amounts of 0.25-0.5 inch over the past 48-72 hours cast uncertainty onto the coverage of receptive fuels. As such, the fire concern will primarily be focused on local areas where dead grasses and other fine fuels have sufficiently dried over the past 24-48 hours. ...Please see www.spc.noaa.gov/fire for graphic product... Read more