Aggregator

WW 0521 Status Updates
STATUS REPORT ON WW 521 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1700 ..WENDT..07/17/25 ATTN...WFO...CAR...GYX...BTV... STATUS REPORT FOR WS 521 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC003-007-017-021-025-172240- ME . MAINE COUNTIES INCLUDED ARE AROOSTOOK FRANKLIN OXFORD PISCATAQUIS SOMERSET NHC003-007-009-172240- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CARROLL COOS GRAFTON NYC019-172240- NY . NEW YORK COUNTIES INCLUDED ARE CLINTON Read more

WW 521 SEVERE TSTM ME NH NY VT 171825Z - 180100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 521 NWS Storm Prediction Center Norman OK 225 PM EDT Thu Jul 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Northern Maine Northern and Central New Hampshire Far Northern New York Northern and Central Vermont * Effective this Thursday afternoon and evening from 225 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible A tornado or two possible SUMMARY...Scattered thunderstorms are forecast to develop and intensify this afternoon across the Watch area. A couple of transient supercells are possible as well as a few organized multicells. The primary severe hazard will be strong to severe gusts (50-65 mph) capable of wind damage, but a tornado is possible with the more intense transient supercells. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 20 miles north northwest of Caribou ME to 15 miles south southwest of Montpelier VT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 400. Mean storm motion vector 23030. ...Smith Read more

No Mesoscale Discussions are in effect as of Thu Jul 17 20:00:13 UTC 2025.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 17 2025 Valid 181200Z - 191200Z A mid-level trough coming into the Pacific Northwest interacting with peripheral monsoon moisture will support mainly dry, isolated high-based thunderstorms across portions of northeastern NV into southeastern ID where pockets of receptive fuels remain. Farther southeast across the Greater Four Corners region, deeper monsoon moisture (precipitable water values greater than 0.80") will support heavier precipitation cores from thunderstorms, mitigating new ignition potential. Otherwise, dry and breezy conditions east of the Cascades are still expected as westerly flow increases from the deepening Pacific Northwest trough. An elevated fire weather threat remains with locally critical conditions possible in favored Cascade gaps amid dry fuels. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1258 AM CDT Thu Jul 17 2025/ ...Synopsis... A deeper trough will traverse the Pacific Northwest on D2/Friday bringing more widespread Elevated conditions across the areas along and east of the Cascades. Afternoon relative humidity around 10-20 percent will overlap sustained westerly winds at 10-15 mph (locally higher). Some locally Critical conditions may persist for a couple of hours where terrain enhancements favor locally stronger winds in the Cascade Gaps. ...Dry Thunderstorms... The western shortwave will bring forcing for ascent across portions of northern Nevada into southern Idaho and eastern Wyoming. This area remains on the periphery of deeper moisture across the Southwest into the Great Basin. High based convection and very dry boundary layer conditions will favor little to no measurable precipitation with potential for new ignitions from lightning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1699 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE OHIO RIVER VALLEY
Mesoscale Discussion 1699 NWS Storm Prediction Center Norman OK 1253 PM CDT Thu Jul 17 2025 Areas affected...portions of the Ohio River Valley Concerning...Severe potential...Watch unlikely Valid 171753Z - 172000Z Probability of Watch Issuance...5 percent SUMMARY...Scattered to numerous thunderstorms are expected along a stalled front over the OH valley. A few of these thunderstorm clusters may produce occasional damaging gusts. A WW is unlikely. DISCUSSION...As of 1745 UTC, regional radar and visible imagery showed scattered thunderstorms increasing in coverage and intensity across much of the OH Valley region. Driven largely by strong heating along a broad stalled frontal zone, a very warm and humid air mass will continue to destabilize through the afternoon. With MLCAPE of 2000-3000 J/kg, scattered to numerous thunderstorms are expected. Vertical shear is weak, but some organization into loose clusters is possible as local outflows consolidate with time. Storm coverage should be maximized ahead of several small-scale features along the front such as the remnant MCV over eastern MO/southern IL and a localized convergence zone across eastern IN northern KY and southwest OH. Radar and CAM trends show a few stronger storms emanating from these clusters. With steep low-level lapse rates and high PWs (1.9-2.1 inches) occasional stronger downdrafts capable of damaging gusts of 45-60 mph are possible. While some local increase in the severe risk is possible over the next few hours, general storm organization still appears limited due to the lack of greater vertical shear and synoptic-scale forcing. Thus, a WW is unlikely. ..Lyons/Smith.. 07/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RLX...JKL...ILN...LMK...IND...PAH...ILX...LSX... SGF... LAT...LON 39108827 38139133 37009101 36898811 37708322 38068191 38788125 39288173 39558319 39108827 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0239 PM CDT Thu Jul 17 2025 Valid 172000Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN HIGH PLAINS AND NORTHERN NEW ENGLAND... ...SUMMARY... Scattered damaging winds and a tornado remain possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...20Z Update... The primary change to the outlook was to add 15 percent wind probabilities across portions of northern into eastern Montana. Here, supercells and/or short line segments should develop amid strong mid/upper flow overspreading the region. Downward momentum transport of this stronger flow aloft may promote efficient severe gust production with the stronger storms. Otherwise, the previous forecast (see below) remains on track, with minor changes made to thunder/severe probabilities to reflect the latest observations and guidance consensus. ..Squitieri.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1125 AM CDT Thu Jul 17 2025/ ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0239 PM CDT Thu Jul 17 2025 Valid 172000Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN HIGH PLAINS AND NORTHERN NEW ENGLAND... ...SUMMARY... Scattered damaging winds and a tornado remain possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...20Z Update... The primary change to the outlook was to add 15 percent wind probabilities across portions of northern into eastern Montana. Here, supercells and/or short line segments should develop amid strong mid/upper flow overspreading the region. Downward momentum transport of this stronger flow aloft may promote efficient severe gust production with the stronger storms. Otherwise, the previous forecast (see below) remains on track, with minor changes made to thunder/severe probabilities to reflect the latest observations and guidance consensus. ..Squitieri.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1125 AM CDT Thu Jul 17 2025/ ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. Read more