SPC Oct 21, 2022 1730 UTC Day 2 Convective Outlook

2 years 9 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Fri Oct 21 2022 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Synopsis... An upper trough is forecast to amplify over the West on Saturday. As this occurs, a persistent upper low offshore of Baja California will begin moving eastward. Across the East, a weak upper low is forecast to drift northward offshore of the GA/Carolina coast, while weak ridging develops upstream of this feature across the Southeast. Southerly low-level flow will increase across much of the central U.S. as a surface cyclone gradually deepens over the northern High Plains. Modest low-level moisture return is expected across parts of the central/southern Plains, but instability is expected to remain minimal across this region through the period. Low/mid-level moistening may support isolated thunderstorm development across parts of AZ/NM. Coverage remains uncertain across this region, but deep-layer shear will be sufficient to support a strong storm or two if deep convection can be sustained. Elsewhere, a broad general thunderstorm area has been maintained from the Pacific Northwest into parts of the central Rockies, where steep midlevel lapse rates and weak buoyancy may support isolated lightning flashes embedded within larger precipitation areas. To the east, weak convection may spread into coastal NC late Saturday night as the upper low drifts northward, with potential for sporadic lightning flashes into early Sunday morning. ..Dean.. 10/21/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 9 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1137 AM CDT Fri Oct 21 2022 Valid 211700Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN WYOMING... ...CRITICAL FIRE WEATHER AREA FOR NORTHERN NEVADA... No changes to the ongoing forecast. Locally elevated conditions remain possible in portions of the Midwest where conditions will be breezy but RH will only be marginally critical in a limited area. ..Wendt.. 10/21/2022 .PREV DISCUSSION... /ISSUED 1236 AM CDT Fri Oct 21 2022/ ...Synopsis... A more progressive pattern develops on Friday as ridging across the western US weakens and a trough deepens across the northern Pacific. Associated with the deepening trough, strong westerly flow aloft will overspread areas from the northern Great Basin into the northern Rockies with continued dry conditions. Critical fire weather conditions are expected across northern Nevada and in southern Wyoming. ...Central and Southern Wyoming... Dry downslope flow across south-central Wyoming will support sustained surface winds at 20-25 mph and afternoon relative humidity around 15-20 percent. Locally stronger winds up to 30+ mph may support pockets of extreme fire weather conditions. As these winds look to be fairly localized, a Critical delineation covers the threat well. ...Northern Great Basin... Across northern Nevada, sustained winds around 15-20 mph, relative humidity around 10-15 percent, and ERCs above the 95th percentile will support a Critical delineation. While winds may be marginal in a few areas, ERCs are well above seasonal averages with below normal rainfall in the last month. ...Central Plains... Sustained winds around 15-20 mph and minimum relative humidity around 15-20 percent will be possible across portions of central Oklahoma into southeastern Kansas. Fuels are moderately receptive across much of Oklahoma, worsening into southeastern Kansas. Higher relative humidity around 20-25 percent will be possible across southeastern Kansas. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Oct 21, 2022 1630 UTC Day 1 Convective Outlook

2 years 9 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Oct 21 2022 Valid 211630Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible near coastal eastern Florida. ...Discussion... The potential for thunderstorms will continue near the east coast of the Florida Peninsula, although the majority of deeper convection should remain offshore. Relatively moist marine air near the coast and relatively cool mid-level temperatures in association with a Southeast States upper low will support this near-coastal thunderstorm potential. Elsewhere, a few lightning flashes could occur across the coastal Pacific Northwest tonight in association with steepening lapse rates via an amplifying upper-level trough. However, overall thunderstorm probabilities/coverage are expected to remain low (below 10 percent). ..Guyer/Squitieri.. 10/21/2022 Read more

SPC Day 2 Fire Weather Outlook

2 years 9 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Thu Oct 20 2022 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN WYOMING... Parts of the northern Great Basin appear much less likely to see sustained elevated fire weather tomorrow afternoon. Based on frontal position in guidance and increasing mid/upper-level clouds, these areas have been removed from the previous forecast. Strengthening southerly/southwesterly winds at low levels within the southern Plains will lead to elevated fire weather as RH falls to 15-25%. Winds of 15-20 mph and gusts around 30 mph are possible. Areas of North Texas could see locally elevated conditions, but fuels receptiveness is marginal enough that large fire potential remains low. Similarly, locally elevated conditions may also occur into central/northern Missouri. Fuels are receptive there, but RH falling below 25% is much more uncertain. The forecast remains unchanged elsewhere. ..Wendt.. 10/20/2022 .PREV DISCUSSION... /ISSUED 0208 AM CDT Thu Oct 20 2022/ ...Synopsis... A trough will begin to deepen across portions of the Pacific Northwest on Friday with enhanced west-northwesterly flow spreading across portions of the Great Basin and northern Rockies. This enhanced flow in combination with dry conditions will allow for increased fire-spread potential. ...Southern Wyoming... Westerly surface winds sustained at 25-30 mph in combination with afternoon relative humidity around 15-20 percent support introducing a Critical delineation across southern Wyoming. Further north, relative humidity will be more marginal and is well covered by the Elevated risk. ...Northern Great Basin to the Central High Plains... A broad area of sustained winds around 15-20 mph and minimum relative humidity around 15-20% will support an Elevated risk of fire weather conditions across much of the northern Great Basin eastward into the High Plains. Across northern Nevada, winds may be a limiting factor. However, fuels in this region are dry and remain receptive, supporting mention of elevated fire weather concerns. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Oct 20, 2022 1730 UTC Day 2 Convective Outlook

2 years 9 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Thu Oct 20 2022 Valid 211200Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... No severe storms are expected across the U.S. Friday. ...Synopsis... An upper trough over the eastern CONUS is forecast to weaken on Friday, though the southern portion of this trough will linger offshore of the FL/GA coast. Another upper-level trough is forecast to amplify over the Northwest through the period. A surface ridge will persist over much of the East, while a surface low is forecast to deepen over the northern High Plains. Modest low-level moisture return will commence over south TX, but buoyancy is expected to remain negligible across this region. Weak convection will be possible across south FL and the FL east coast, but the primary thunderstorm threat is expected to remain offshore. Weak embedded convection will also be possible as precipitation spreads inland across the Northwest in association with the upper-level trough, but very limited buoyancy is expected to limit thunderstorm potential. ..Dean.. 10/20/2022 Read more

SPC Oct 20, 2022 1630 UTC Day 1 Convective Outlook

2 years 9 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Oct 20 2022 Valid 201630Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the 48 contiguous states. ...Discussion... The prevalence of continental trajectories and stable conditions will considerably limit convective potential across the Lower 48 today. Any lingering thunderstorms should remain off the coast of southeast Florida. ..Guyer/Bentley.. 10/20/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 9 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CDT Thu Oct 20 2022 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND EASTERN MONTANA... No changes to the ongoing forecast. ..Wendt.. 10/20/2022 .PREV DISCUSSION... /ISSUED 0120 AM CDT Thu Oct 20 2022/ ...Synopsis... As the southwestern ridge begins to lose amplitude, a shortwave disturbance will translate southeastward across portions of the High Plains, bringing enhanced westerly flow amid dry and unseasonably warm conditions. Stronger winds can be expected in the downslope regions of central/eastern Montana and eastern Wyoming where fuels remain very dry and receptive to fire spread. ...Central and Eastern Montana... Sustained westerly surface winds at 15-20 mph, along with minimum relative humidity around 15-20 percent, are expected across portions of Montana. Fuels across this region are in the 80th-90th percentile with minimal rainfall in the last 7-14 days. These conditions will support Elevated and Critical fire weather delineations. With disagreement in guidance on the overall strength of the winds, the region of highest confidence for a Critical risk will be in the downslope regions downwind of the high terrain in central Montana, where ensemble guidance has highest likelihood of sustained winds of 20 mph. ...Eastern Wyoming... Sustained westerly winds and enhanced downslope flow around 15-20 mph in combination with relative humidity around 15-20 percent are expected across portions of eastern Wyoming Thursday. With marginal relative humidity and receptive fuels, an Elevated delineation is appropriate, though a few stations may briefly approach critical. ...Ohio Valley... Continued windy and dry conditions amid receptive fuels will support an Elevated delineation from western Kentucky northward into southern Illinois and Indiana. Though the winds are a limiting factor, relative humidity around 25-30 percent (locally as low as 20 percent) and ERCs at or above the 95th percentile will support increased risk of fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Oct 19, 2022 1730 UTC Day 2 Convective Outlook

2 years 9 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Wed Oct 19 2022 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the U.S. on Thursday. ...Synopsis... A mid-level trough will gradually amplify across the western and central U.S. while an upper trough ejects into the Atlantic from the Eastern Seaboard tomorrow/Thursday. Widespread cool, dry, and stable low-level air will meander over the CONUS through the period, limiting thunderstorm development to the east-central Florida Peninsula coastline. These thunderstorms are most likely during the afternoon hours and are not anticipated to be severe. ..Squitieri.. 10/19/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 9 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Wed Oct 19 2022 Valid 191700Z - 201200Z Expanded the Elevated delineation slightly farther north across eastern Wyoming and southwest South Dakota based on morning forecast guidance. Otherwise, the remainder of the forecast appears on track. ..Bentley.. 10/19/2022 .PREV DISCUSSION... /ISSUED 0107 AM CDT Wed Oct 19 2022/ ...Synopsis... Elevated to locally critical fire weather conditions are anticipated this afternoon across portions of the central High Plains. This threat will largely be driven by a weak upper-level disturbance over south-central Canada that is forecast to propagate southward through the Plains within a northerly flow regime. The low-level mass response ahead of the wave will result in breezy northwesterly winds across the central High Plains where fuels are fairly dry. Elsewhere across the CONUS, dry conditions will prevail as an unseasonably dry air mass lingers across the central U.S.; however, weak winds will generally limit additional concerns. ...Central High Plains... Early-morning surface observations show dry conditions across southeast WY into northeast CO with dewpoints in the 20s. While this region is on the periphery of the driest air to the east, increasing northwest winds will support downslope warming/drying this afternoon. RH reductions down to 15-25% are expected with sustained winds between 15-25 mph (gusting to 30 mph at times). A swath of elevated wind/RH conditions is expected across the region with periods of critical conditions probable for southeast WY into parts of the NE Panhandle and far northeast CO. Consideration was given for a Critical risk area, but somewhat poor ensemble consensus on the duration and coverage of these conditions precluded an upgrade. Regardless, recent fuel analyses show adequately dry fuels with ERC values above seasonal average (generally in the 80-90th percentiles), which should support the fire weather concern. ...Lower OH River Valley... Brief and localized elevated conditions may materialize this afternoon across southern IL into southwest IN where winds may approach 15 mph with RH values in the mid 20s. Parts of this region that have seen little rainfall over the past 1-2 weeks have likely maintained dry fuels, but limited confidence in wind magnitudes precludes additional highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Oct 19, 2022 1300 UTC Day 1 Convective Outlook

2 years 9 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1100 AM CDT Wed Oct 19 2022 Valid 191300Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across much of the nation today through tonight. ...Synopsis... Models suggest that the westerlies will trend a bit more zonal and progressive today across the northern mid-latitude Pacific into the Canadian Prairies. Downstream, it appears that the center of the remnant cyclone over the lower Great Lakes vicinity will redevelop north-northeast of Lake Huron by late tonight, but large-scale mid-level troughing is forecast to persist across most areas east of the Mississippi Valley. In the wake of one embedded short wave impulse now beginning to pivot north-northeastward into and across the Northeast, cold surface ridging will be maintained across much of the Gulf Coast vicinity, while also building northeastward across the south Atlantic Seaboard into the adjacent western Atlantic. This will contribute to the maintenance of generally dry and/or stable conditions across much of the U.S., with negligible risk for thunderstorm activity. ...Lower Great Lakes vicinity... The axis of the mid-level cold core near the 500 mb level is now in the process of pivoting northeast of Lake Erie. As it overspreads Lake Ontario this afternoon, CAPE for boundary-layer parcels over the relatively warm waters will increase as equilibrium levels rise, and thermodynamic profiles may become marginally conducive to charge separation within associated convective development. Occasional lightning flashes are possible, but any potential for sustained bands appears generally confined to the immediate eastern shores of Lake Ontario (around Watertown) late this afternoon and evening, where/when low-level flow is forecast to strengthen and veer from a southerly to southwesterly component. ..Kerr.. 10/19/2022 Read more

SPC Oct 18, 2022 1730 UTC Day 2 Convective Outlook

2 years 9 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Tue Oct 18 2022 Valid 191200Z - 201200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... No severe weather is expected across the U.S. Wednesday. ...Synopsis... An upper low will pivot over eastern Ontario/western Quebec and the lower Great Lakes region, while the attendant trough envelops the eastern U.S. At the surface, a cold front will mostly extend mostly well offshore across the southern Gulf of Mexico and the western Atlantic water, arcing into central Maine Wednesday morning. The front will quickly shift east across eastern Maine during the morning. Cold temperatures aloft, resulting in steep midlevel lapse rates beneath the Great Lakes upper low could support a lightning flash or two over Lakes Ontario and Erie in lake effect convection, but coverage will remain low and confined to offshore waters. Otherwise, stable conditions amid widespread surface high pressure across the remainder of the CONUS will preclude thunderstorm activity. ..Leitman.. 10/18/2022 Read more

SPC Day 1 Fire Weather Outlook

2 years 9 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1158 AM CDT Tue Oct 18 2022 Valid 181700Z - 191200Z No changes. See previous discussion below. ..Bentley.. 10/18/2022 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Oct 18 2022/ ...Synopsis... Elevated fire weather conditions are expected this afternoon across portions of the central Gulf Coast as a dry post-frontal air mass overspreads the region. Localized fire weather concerns may develop across portions of the eastern Plains as near-record-low dewpoints linger of the region. Dry conditions will persist across the northern Great Basin, but ridging over the northwest CONUS will limit wind speeds, modulating the fire weather threat. ...Gulf Coast... An offshore flow regime has become established along the central Gulf Coast after a cold frontal passage late Monday. Latest guidance suggests that strong cold advection will be in place over the coast by peak heating, which will aid in steepening low-level lapse rates and downward mixing of 20-25 mph winds. Ensemble guidance continues to show reasonably high probability in RH values in the 20-30% range, which will support elevated fire weather conditions over an area with ERC values above the 90th percentile. ...Eastern Plains to East Texas... Early-morning surface observations across eastern NE/KS and western IA/MO are sampling single digit to low-teen dewpoints, which are near record low values for mid October. This unseasonably dry air mass will yield RH values between 20-25% from the lower MO River Valley to eastern TX as it migrates south through the day. Winds generally between 10-15 mph may occasionally gust into the upper teens and low 20s, resulting in periods of elevated fire weather conditions. Low confidence in the sustenance and coverage of these conditions over areas that have not received recent rainfall precludes additional highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Oct 18, 2022 1630 UTC Day 1 Convective Outlook

2 years 9 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Tue Oct 18 2022 Valid 181630Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely today and tonight. ...Florida... A cluster of showers and some embedded thunderstorms is approaching the southwest Florida Peninsula early this afternoon. Preceding anvil-related cloud debris is overspreading the region, but some cloud breaks are noted particularly in vicinity of the front across the central/south-central Peninsula where modest boundary-layer destabilization is occurring. Further warming and steepening of low-level lapse rates could allow for a few stronger storms to develop along the front and/or near the east coast of the southern Peninsula this afternoon. However, the potential for severe storms should be limited by weak mid-level lapse rates and modest low-level convergence, with organized/sustained severe storms not currently anticipated. ..Guyer/Smith.. 10/18/2022 Read more
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