SPC Severe Thunderstorm Watch 544

3 weeks 3 days ago
WW 544 SEVERE TSTM NE SD 262240Z - 270300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 544 NWS Storm Prediction Center Norman OK 440 PM MDT Sat Jul 26 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Central Nebraska Far Southwest and South-Central South Dakota * Effective this Saturday afternoon and evening from 440 PM until 900 PM MDT. * Primary threats include... Isolated damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A line of thunderstorms moving eastward out of the NE Panhandle may produce damaging gusts as it moves into more of western and central NE this afternoon and evening. Some more cellular activity is possible across farther north across far southwest/south-central SD, where damaging gusts and isolated hail are possible. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 45 miles northwest of Valentine NE to 15 miles east southeast of Imperial NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...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 27030. ...Mosier Read more

SPC MD 1798

3 weeks 3 days ago
MD 1798 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF CENTRAL SOUTH DAKOTA
Mesoscale Discussion 1798 NWS Storm Prediction Center Norman OK 0641 PM CDT Sat Jul 26 2025 Areas affected...portions of central South Dakota Concerning...Severe potential...Watch possible Valid 262341Z - 270045Z Probability of Watch Issuance...40 percent SUMMARY...Splitting supercells should persist for at least a few more hours in a localized but very favorable environment for severe hazards, including very large hail or a tornado. DISCUSSION...A pair of splitting supercells continue to mature over portions of central SD near the surface low, where large amounts of low-level vertical-oriented vorticity resides. Furthermore, extreme instability precedes the storms, with the latest mesoanalysis showing over 5000 J/kg MLCAPE in place. Finally, with 40 kts of effective bulk shear overspreading this extreme instability, and given 200 m2/s2 effective SRH across northern SD, it seems plausible that a localized but potentially significant-severe threat may accompany these storms over the next few hours. 2+ inch diameter hail will probably be the main hazard with these storms, though a landspout/supercell hybrid tornado could accompany the southern supercell if it can successfully stretch the vertical vorticity in place. It is unclear if a WW issuance is needed at this point given how sparse these storms are. However, upscale-growing storms may approach the Dakotas this evening into the overnight, where greater coverage will exist, and when a WW issuance may be necessary. ..Squitieri/Mosier.. 07/26/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...UNR... LAT...LON 44610124 45060115 45390099 45560078 45560039 45330022 45080015 44800017 44590053 44550098 44610124 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

SPC MD 1797

3 weeks 3 days ago
MD 1797 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF WESTERN INTO SOUTHERN PENNSYLVANIA
Mesoscale Discussion 1797 NWS Storm Prediction Center Norman OK 0600 PM CDT Sat Jul 26 2025 Areas affected...portions of western into southern Pennsylvania Concerning...Severe potential...Watch unlikely Valid 262300Z - 270030Z Probability of Watch Issuance...20 percent SUMMARY...A few damaging gusts may occur over the next few hours. The overall severe threat should remain isolated. DISCUSSION...An MCS has been steadily organizing over western PA over the past couple of hours. This MCS will continue to propagate east-southeastward amid a buoyant airmass, characterized by over 2000 J/kg MLCAPE. Furthermore, deep-layer westerly flow around the upper ridge is promoting roughly 35 kts of effective speed shear, oriented roughly perpendicular to the MCS leading-line. This may foster continued organization of the MCS, with a few strong, damaging wind gusts possible. The best chance for damaging gusts will be with storm interactions between cells embedded in the MCS with those in the free warm sector. However, severe gusts should remain more sparse, so a Severe Thunderstorm Watch issuance is not currently expected. ..Squitieri/Mosier.. 07/26/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CTP...PBZ... LAT...LON 41347971 41277862 40957747 40617675 40237645 39977659 39867701 39827771 39897836 39967892 40107944 40247970 40507990 41347971 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC MD 1796

3 weeks 3 days ago
MD 1796 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN WYOMING INTO SOUTHEAST MONTANA AND THE WESTERN DAKOTAS
Mesoscale Discussion 1796 NWS Storm Prediction Center Norman OK 0534 PM CDT Sat Jul 26 2025 Areas affected...Northern Wyoming into southeast Montana and the western Dakotas Concerning...Severe potential...Watch possible Valid 262234Z - 270030Z Probability of Watch Issuance...40 percent SUMMARY...An uptick in convection is noted across northern WY into southeast MT. Trends are being monitored for the potential development of an organized cluster/line later this evening. Timing remains uncertain, but watch issuance is possible if/when this cluster begins to emerge and pose severe wind threat. DISCUSSION...Increasing ascent ahead of a mid-level wave over central WY is evident in recent GOES imagery across northern WY into southeast MT. Within the past hour or so, the number of shallow convective cores, as well as the depth/intensity of existing cores, has begun to increase as ascent attendant to the wave begins to overspread a modestly buoyant air mass in place across the northern High Plains. Over the next couple of hours, coverage of initially cellular, high-based thunderstorms should increase before gradual cold pool amalgamation begins to occur. It remains unclear if cold pool consolidation will be sufficient for the development of a more prominent convective cluster/line, but recent CAM guidance suggests that this could be the initiation zone for a more prolonged MCS that moves northeast into the western Dakotas later this evening. Regardless, in the short term, the high-based nature of the storms within a deeply mixed environment should support the potential for strong to severe downburst winds. A few instances of large hail are also possible within initially discrete cells given increasing deep-layer winds shear with the approach of the upper wave. Convective trends will continue to be monitored, and watch issuance is possible later this evening if/when an organized cluster or line begins to emerge. ..Moore/Mosier.. 07/26/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...UNR...BYZ...RIW... LAT...LON 43800557 43610633 43640712 44100783 44590804 44920795 46470447 46510360 46300307 45820272 45360264 45010267 44580294 44330326 43800557 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC MD 1795

3 weeks 3 days ago
MD 1795 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWEST TO NORTHEAST MONTANA
Mesoscale Discussion 1795 NWS Storm Prediction Center Norman OK 0505 PM CDT Sat Jul 26 2025 Areas affected...Southwest to northeast Montana Concerning...Severe potential...Watch unlikely Valid 262205Z - 270000Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms developing across southwest to central Montana may produce sporadic severe gusts through early evening. This threat is expected to remain sufficiently limited to preclude watch issuance. DISCUSSION...Over the past 1-2 hours, thunderstorms have been slowly deepening/maturing across southwest to central MT as they develop within a modestly moist/deeply mixed air mass. Based on observed dewpoint depressions (around 30 F) and recent forecast soundings, LCLs are likely around 3 km, which will favor strong sub-cloud evaporational cooling and downdraft acceleration within ongoing convection. Additionally, ascent ahead of an approaching, but low-amplitude, upper-level wave will continue to promote thunderstorm development over the next few hours. As such, the potential for a few severe gusts should increase across the region, especially if a more consolidated/organized cluster emerges out of this activity as hinted by recent CAM guidance. Given the unfocused forcing for ascent and recent convective trends, confidence in where/when/if such as cluster emerges is low. More robust/long-lived severe storms, including the potential for a supercell or two and/or organized cluster, may exists across northeast MT where richer low-level moisture is promoting MLCAPE values on the order of 1000-2000 J/kg, and deep-layer shear is adequate (30-35 knots) for storm organization. Weaker forcing for ascent casts uncertainty on storm coverage, but trends will be monitored given the favorable convective environment and the potential for a focused corridor of relatively higher severe threat. ..Moore/Mosier.. 07/26/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...TFX...MSO... LAT...LON 47120441 46780483 46480569 45600977 45610994 45441148 45541209 45841265 46261291 46621275 46981229 49010822 49050506 48940443 48720417 48310404 47840404 47550413 47280426 47120441 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC Severe Thunderstorm Watch 545

3 weeks 3 days ago
WW 545 SEVERE TSTM MT 262345Z - 270700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 545 NWS Storm Prediction Center Norman OK 545 PM MDT Sat Jul 26 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Montana * Effective this Saturday afternoon and Sunday morning from 545 PM until 100 AM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms across central MT have shown more northeastward progression over the past hour or so. This upscale growth will likely continue as amalgamation of outflows persists, with the resulting convective line then expected to continue northeastward into more of northeast MT. Strong gusts will be possible with this line throughout the evening. Isolated hail is possible with any more discrete, cellular thunderstorms that develop ahead of the line. The severe thunderstorm watch area is approximately along and 75 statute miles north and south of a line from 40 miles northwest of Lewistown MT to 55 miles east of Wolf Point MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 544... AVIATION...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 24030. ...Mosier Read more

Eastern North Pacific Tropical Weather Outlook

3 weeks 3 days ago
846
ABPZ20 KNHC 262338
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sat Jul 26 2025

For the eastern and central North Pacific east of 180 longitude:

Eastern portion of Central Pacific (CP90):
Showers and thunderstorms have become slightly better organized in
association with an area of low pressure located about 950 miles
southeast of the Hawaiian Islands. Additional development of this
system is expected as it moves generally westward staying well south
of the Hawaiian Islands, and a short-lived tropical depression is
likely to form during the next few days.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...70 percent.

Western East Pacific:
A trough of low pressure about 1500 miles east-southeast of the
Hawaiian Islands is producing a large area of disorganized showers
and thunderstorms. Some slow development of this system is possible
as it moves generally westward during the next several days.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...30 percent.

South of Southwestern Mexico:
An area of low pressure is forecast to form well offshore of the
southwestern coast of Mexico early next week. Thereafter,
environmental conditions appear conducive for gradual development,
and a tropical depression could form during the middle to latter
part of next week as the system moves west-northwestward or
northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...40 percent.

$$
Forecaster Bucci
NHC Webmaster

SPC MD 1794

3 weeks 3 days ago
MD 1794 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF FAR EASTERN ILLINOIS INTO CENTRAL INDIANA AND OHIO
Mesoscale Discussion 1794 NWS Storm Prediction Center Norman OK 0434 PM CDT Sat Jul 26 2025 Areas affected...portions of far eastern Illinois into central Indiana and Ohio Concerning...Severe potential...Watch unlikely Valid 262134Z - 262330Z Probability of Watch Issuance...20 percent SUMMARY...A few damaging gusts may accompany the stronger storms as they continue to coalesce through the afternoon. DISCUSSION...Several pulse-cellular and multicellular storms have organized from eastern IL into OH over the past few hours. Ahead of these storms resides strong buoyancy (e.g. 3000 J/kg MLCAPE), but modest vertical wind shear (20-30 kts of effective bulk shear). The current thinking is that strong wind gusts are possible with the stronger wet downbursts, and a severe gust or two cannot be ruled out, particularly with merging storm cold pools. However, the overall severe threat should remain isolated. ..Squitieri/Mosier.. 07/26/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...RLX...CLE...ILN...IWX...IND...LOT...ILX... LAT...LON 40988867 41398753 41418421 41118207 40678127 40218085 39758097 39578166 39668260 39838395 40008583 39918717 39888790 39918827 40988867 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC MD 1793

3 weeks 3 days ago
MD 1793 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR MUCH OF CENTRAL INTO NORTHERN SOUTH DAKOTA INTO SOUTHERN NORTH DAKOTA
Mesoscale Discussion 1793 NWS Storm Prediction Center Norman OK 0350 PM CDT Sat Jul 26 2025 Areas affected...much of central into northern South Dakota into southern North Dakota Concerning...Severe potential...Watch possible Valid 262050Z - 262315Z Probability of Watch Issuance...60 percent SUMMARY...Storms will increase over the next 1-2 hours over central South Dakota, with further activity developing north/northeastward into southern North Dakota. Damaging winds appear likely, with locally large hail. Isolated significant gusts cannot be ruled out. DISCUSSION...Visible imagery shows storms beginning to develop near the surface low over south-central SD, in a very steep lapse rate environment. The 18Z UNR soundings shows 9.5 C/km midlevel lapse rates, and modest westerlies aloft. East of there, surface analysis depicts MLCAPE in excess of 3000 J/kg, and a theta-e axis roughly along the ND/SD border counties. Given the observed TCU vigor over south-central SD currently, this may be the initiation point for a larger-scale, northward-propagating complex of storms depicted in some CAM solutions. Otherwise, it is also possible outflow from high-based storms coming out of WY into western NE may produce outflow aiding further development as well. ..Jewell.. 07/26/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...FSD...ABR...BIS...UNR... LAT...LON 43140128 43830130 44500152 45160194 45550265 46150284 46800235 47290018 47319857 46949712 46709687 46289670 45579699 45589706 43979908 43360008 43060102 43140128 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC Severe Thunderstorm Watch 544

3 weeks 3 days ago
WW 544 SEVERE TSTM NE SD 262240Z - 270300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 544 NWS Storm Prediction Center Norman OK 440 PM MDT Sat Jul 26 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Central Nebraska Far Southwest and South-Central South Dakota * Effective this Saturday afternoon and evening from 440 PM until 900 PM MDT. * Primary threats include... Isolated damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A line of thunderstorms moving eastward out of the NE Panhandle may produce damaging gusts as it moves into more of western and central NE this afternoon and evening. Some more cellular activity is possible across farther north across far southwest/south-central SD, where damaging gusts and isolated hail are possible. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 45 miles northwest of Valentine NE to 15 miles east southeast of Imperial NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...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 27030. ...Mosier Read more

SPC Day 3-8 Fire Weather Outlook

3 weeks 3 days ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0447 PM CDT Sat Jul 26 2025 Valid 281200Z - 031200Z Sub-tropical ridging over the central and eastern US is forecast to intensify late this weekend and through much of next week. At the same time, broad troughing will develop over the West, allowing for increased thunderstorm chances across the Northwest. Fire-weather potential should gradually increase through the extended forecast period. ...Northwest... Broad Pacific troughing should begin to develop across the West Coast early next week as the upper ridge intensifies to the east. Flow aloft will gradually turn more meridional as several weak disturbances move northeastward across the West. An increase in mid-level moisture (PWATS 0.7-1 inch) is likely with the broad troughing. This should support a general increase in thunderstorm chances over much of the region through next week. Current guidance shows isolated thunderstorms beginning as by late D3/Monday into early D4/Tuesday across northern CA and southern OR. These initial storms will likely be dry given steep lapse rates and PWATS generally below one inch. Confidence in greater storm coverage and lightning potential increases into D5/Wednesday as a more pronounced perturbation is forecast to move across the northern Great Basin farther into the Northwest. However, a slow increase in low to mid-level moisture each day and continued rainfall should being to limit the opportunity for dry lightning strikes, creating uncertainty on IsoDryT coverage. Some lightning threat is likely to persist through D6/Thursday, though details remain too limited to introduce probabilities. ...Great Basin... As the upper ridge builds, flow aloft will generally weaken through the next several days. The exception to this may be ahead of the stronger perturbation midweek next week. While not overly pronounced, some guidance shows enhanced flow aloft over spreading drier parts of the eastern Great basin D5/Wednesday. This could support some dry and breezy conditions favorable for elevated to locally critical fire-weather concerns through the end of the week. ..Lyons.. 07/26/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

3 weeks 3 days ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0447 PM CDT Sat Jul 26 2025 Valid 281200Z - 031200Z Sub-tropical ridging over the central and eastern US is forecast to intensify late this weekend and through much of next week. At the same time, broad troughing will develop over the West, allowing for increased thunderstorm chances across the Northwest. Fire-weather potential should gradually increase through the extended forecast period. ...Northwest... Broad Pacific troughing should begin to develop across the West Coast early next week as the upper ridge intensifies to the east. Flow aloft will gradually turn more meridional as several weak disturbances move northeastward across the West. An increase in mid-level moisture (PWATS 0.7-1 inch) is likely with the broad troughing. This should support a general increase in thunderstorm chances over much of the region through next week. Current guidance shows isolated thunderstorms beginning as by late D3/Monday into early D4/Tuesday across northern CA and southern OR. These initial storms will likely be dry given steep lapse rates and PWATS generally below one inch. Confidence in greater storm coverage and lightning potential increases into D5/Wednesday as a more pronounced perturbation is forecast to move across the northern Great Basin farther into the Northwest. However, a slow increase in low to mid-level moisture each day and continued rainfall should being to limit the opportunity for dry lightning strikes, creating uncertainty on IsoDryT coverage. Some lightning threat is likely to persist through D6/Thursday, though details remain too limited to introduce probabilities. ...Great Basin... As the upper ridge builds, flow aloft will generally weaken through the next several days. The exception to this may be ahead of the stronger perturbation midweek next week. While not overly pronounced, some guidance shows enhanced flow aloft over spreading drier parts of the eastern Great basin D5/Wednesday. This could support some dry and breezy conditions favorable for elevated to locally critical fire-weather concerns through the end of the week. ..Lyons.. 07/26/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

3 weeks 3 days ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0447 PM CDT Sat Jul 26 2025 Valid 281200Z - 031200Z Sub-tropical ridging over the central and eastern US is forecast to intensify late this weekend and through much of next week. At the same time, broad troughing will develop over the West, allowing for increased thunderstorm chances across the Northwest. Fire-weather potential should gradually increase through the extended forecast period. ...Northwest... Broad Pacific troughing should begin to develop across the West Coast early next week as the upper ridge intensifies to the east. Flow aloft will gradually turn more meridional as several weak disturbances move northeastward across the West. An increase in mid-level moisture (PWATS 0.7-1 inch) is likely with the broad troughing. This should support a general increase in thunderstorm chances over much of the region through next week. Current guidance shows isolated thunderstorms beginning as by late D3/Monday into early D4/Tuesday across northern CA and southern OR. These initial storms will likely be dry given steep lapse rates and PWATS generally below one inch. Confidence in greater storm coverage and lightning potential increases into D5/Wednesday as a more pronounced perturbation is forecast to move across the northern Great Basin farther into the Northwest. However, a slow increase in low to mid-level moisture each day and continued rainfall should being to limit the opportunity for dry lightning strikes, creating uncertainty on IsoDryT coverage. Some lightning threat is likely to persist through D6/Thursday, though details remain too limited to introduce probabilities. ...Great Basin... As the upper ridge builds, flow aloft will generally weaken through the next several days. The exception to this may be ahead of the stronger perturbation midweek next week. While not overly pronounced, some guidance shows enhanced flow aloft over spreading drier parts of the eastern Great basin D5/Wednesday. This could support some dry and breezy conditions favorable for elevated to locally critical fire-weather concerns through the end of the week. ..Lyons.. 07/26/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

3 weeks 3 days ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0447 PM CDT Sat Jul 26 2025 Valid 281200Z - 031200Z Sub-tropical ridging over the central and eastern US is forecast to intensify late this weekend and through much of next week. At the same time, broad troughing will develop over the West, allowing for increased thunderstorm chances across the Northwest. Fire-weather potential should gradually increase through the extended forecast period. ...Northwest... Broad Pacific troughing should begin to develop across the West Coast early next week as the upper ridge intensifies to the east. Flow aloft will gradually turn more meridional as several weak disturbances move northeastward across the West. An increase in mid-level moisture (PWATS 0.7-1 inch) is likely with the broad troughing. This should support a general increase in thunderstorm chances over much of the region through next week. Current guidance shows isolated thunderstorms beginning as by late D3/Monday into early D4/Tuesday across northern CA and southern OR. These initial storms will likely be dry given steep lapse rates and PWATS generally below one inch. Confidence in greater storm coverage and lightning potential increases into D5/Wednesday as a more pronounced perturbation is forecast to move across the northern Great Basin farther into the Northwest. However, a slow increase in low to mid-level moisture each day and continued rainfall should being to limit the opportunity for dry lightning strikes, creating uncertainty on IsoDryT coverage. Some lightning threat is likely to persist through D6/Thursday, though details remain too limited to introduce probabilities. ...Great Basin... As the upper ridge builds, flow aloft will generally weaken through the next several days. The exception to this may be ahead of the stronger perturbation midweek next week. While not overly pronounced, some guidance shows enhanced flow aloft over spreading drier parts of the eastern Great basin D5/Wednesday. This could support some dry and breezy conditions favorable for elevated to locally critical fire-weather concerns through the end of the week. ..Lyons.. 07/26/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more