Aggregator

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... A few mixed mode (i.e., dry/wet) thunderstorms are possible along the leading edge of the northward-moving monsoonal moisture surge across portions of Nevada into western Utah Day 2/Tuesday afternoon/evening. However, the expected relatively quick transition towards generally wetter thunderstorms -- with precipitable water values rapidly increasing above 0.75" -- coupled with relatively sparse fuels for large fire spread across portions of this area preclude the introduction of a fire weather area at this time. Otherwise, the fire weather forecast remains on track. See previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 02 2019/ ...Synopsis... An upper-level ridge will remain fortified across the western CONUS, with another mid-level shortwave trough cresting the ridge and traversing the Pacific Northwest during the Day 2/Tuesday period. As such, mildly breezy and dry conditions may be observed east of the Cascades. Deep-layer ascent and marginal instability accompanying the aforementioned shortwave may yield very isolated thunderstorm development across parts of the Pacific Northwest. ...Pacific Northwest... Downslope flow along the lee of the Cascades, particularly in Oregon, may support up to 15 mph sustained westerly winds and 15-20% RH by afternoon peak heating. Currently, the latest model guidance differs in the placement and timing of elevated conditions, precluding a delineation. In addition, enhanced lift may also foster the development of a couple thunderstorms, especially along the lee of the northern Cascades in Washington. Given precipitable water values in the 0.50-0.75 inch range, a dry strike or two cannot be ruled out. ...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 0218 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... A few mixed mode (i.e., dry/wet) thunderstorms are possible along the leading edge of the northward-moving monsoonal moisture surge across portions of Nevada into western Utah Day 2/Tuesday afternoon/evening. However, the expected relatively quick transition towards generally wetter thunderstorms -- with precipitable water values rapidly increasing above 0.75" -- coupled with relatively sparse fuels for large fire spread across portions of this area preclude the introduction of a fire weather area at this time. Otherwise, the fire weather forecast remains on track. See previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 02 2019/ ...Synopsis... An upper-level ridge will remain fortified across the western CONUS, with another mid-level shortwave trough cresting the ridge and traversing the Pacific Northwest during the Day 2/Tuesday period. As such, mildly breezy and dry conditions may be observed east of the Cascades. Deep-layer ascent and marginal instability accompanying the aforementioned shortwave may yield very isolated thunderstorm development across parts of the Pacific Northwest. ...Pacific Northwest... Downslope flow along the lee of the Cascades, particularly in Oregon, may support up to 15 mph sustained westerly winds and 15-20% RH by afternoon peak heating. Currently, the latest model guidance differs in the placement and timing of elevated conditions, precluding a delineation. In addition, enhanced lift may also foster the development of a couple thunderstorms, especially along the lee of the northern Cascades in Washington. Given precipitable water values in the 0.50-0.75 inch range, a dry strike or two cannot be ruled out. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0631 Status Updates
STATUS FOR WATCH 0631 HAS NOT BEEN ISSUED YET Read more

MD 1912 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE MID-ATLANTIC INTO THE NORTHEAST
Mesoscale Discussion 1912 NWS Storm Prediction Center Norman OK 0101 PM CDT Mon Sep 02 2019 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Watch unlikely Valid 021801Z - 022000Z Probability of Watch Issuance...20 percent SUMMARY...Storms are developing across portions of the Mid-Atlantic into the Northeast. These storms could produce marginally severe hail/wind and a brief, weak tornado. DISCUSSION...A broad upper-level trough is over Ontario/Quebec with multiple mid-level disturbance rotating around the base of it across the eastern Great Lakes into the Northeast. A surface pressure trough is extending southward through eastern New York helping to enhance surface convergence with south-southeast surface winds ahead of it. Storms within a narrow corridor across northern New Jersey into NYC/vicinity may become capable of a brief, weak tornado given the backing low-level winds. However, cloud cover has limited insolation across this area thus far, inhibiting low-level instability. Farther south in southeast Pennsylvania into northern Virginia, the Cu field is maturing, but updrafts are struggling to mature via satellite/radar imagery. As buoyancy/instability increase during the afternoon, storms will develop amid MLCAPE of 1000-1500 J/kg and move eastward. Shear is increasing with time with the passage of the upper-level trough to the north, which will allow some marginal storm organization. A broken line of storms is likely to form with marginally severe hail/wind possible. Given the isolated, marginal severe risk, a watch issuance is unlikely. ..Nauslar/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...CTP...LWX...PBZ... LAT...LON 40657549 41017429 41247330 41097297 40697279 40307313 39827389 39567460 39007665 39137863 39407923 39637884 39917801 40327709 40657549 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

000
ABPZ20 KNHC 021734
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Mon Sep 2 2019

For the eastern North Pacific...east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical
Storm Juliette, located several hundred miles south-southwest of the
southern tip of the Baja California peninsula.

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Blake

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Mon Sep 02 2019 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN DAKOTAS AND CENTRAL MINNESOTA TO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a tornado risk along the Florida east coast. ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. ..Guyer/Nauslar.. 09/02/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Mon Sep 02 2019 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN DAKOTAS AND CENTRAL MINNESOTA TO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a tornado risk along the Florida east coast. ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. ..Guyer/Nauslar.. 09/02/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Mon Sep 02 2019 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN DAKOTAS AND CENTRAL MINNESOTA TO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a tornado risk along the Florida east coast. ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. ..Guyer/Nauslar.. 09/02/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Mon Sep 02 2019 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN DAKOTAS AND CENTRAL MINNESOTA TO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a tornado risk along the Florida east coast. ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. ..Guyer/Nauslar.. 09/02/2019 Read more

No watches are valid as of Mon Sep 2 16:51:07 UTC 2019.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook CORR 1 NWS Storm Prediction Center Norman OK 1144 AM CDT Mon Sep 02 2019 Valid 021700Z - 031200Z CORRECTED FOR AREA TYPE ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN IDAHO... The forecast remains on track with only minor changes needed based on the latest observations and ensemble/deterministic guidance. Please see discussion below for more information on today's fire weather threat. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Mon Sep 02 2019/ ...Synopsis... A well-defined 500 mb impulse, accompanied by 50+ knot winds, will crest an upper-level ridge across the northern Rockies during the afternoon. A response to the surface mass fields will ensue, with breezy, dry conditions prevailing across parts of the central/northern Rockies and northern Great Basin, promoting conditions favorable for wildfire spread. In addition, monsoonal moisture return across parts of the Great Basin may induce isolated thunderstorm activity over dry fuels. ...Northern/central Rockies into the Great Basin... As the aforementioned impulse glances by to the north, afternoon heating will help transport the stronger flow aloft towards the surface via a deeply mixed boundary layer. 15-20 mph westerly flow and RH under 20% should become commonplace across much of the northern Great Basin into parts of the central/northern Rockies, where an elevated area remains in place. A critical area has also been maintained for portions of the Snake River Plain, where downslope flow along the lee of the southeast Bitterroot Mountains will augment the ambient flow fields to support 20-25 mph sustained westerly surface winds and 10-20% RH. Here, fuels are also critically dry, which would support wildfire-spread potential given the aforementioned wind/RH conditions. Farther southwest into the Great Basin (i.e. Nevada into far western Utah), localized elevated wind/RH may occur during afternoon peak heating, though the brevity of such conditions precludes a delineation at this time. Given the well-mixed boundary layer, any storms that can develop in the Great Basin will be high-based, with at least a few dry strikes possible over critically dry fuels, potentially supporting ignitions. This is especially the case where dry downbursts may occur, where brief but erratic surface winds may worsen the spread of grass fires from recent ignitions. Nonetheless, storm coverage appears too sparse at this time to warrant an isolated dry thunderstorm delineation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook CORR 1 NWS Storm Prediction Center Norman OK 1144 AM CDT Mon Sep 02 2019 Valid 021700Z - 031200Z CORRECTED FOR AREA TYPE ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN IDAHO... The forecast remains on track with only minor changes needed based on the latest observations and ensemble/deterministic guidance. Please see discussion below for more information on today's fire weather threat. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Mon Sep 02 2019/ ...Synopsis... A well-defined 500 mb impulse, accompanied by 50+ knot winds, will crest an upper-level ridge across the northern Rockies during the afternoon. A response to the surface mass fields will ensue, with breezy, dry conditions prevailing across parts of the central/northern Rockies and northern Great Basin, promoting conditions favorable for wildfire spread. In addition, monsoonal moisture return across parts of the Great Basin may induce isolated thunderstorm activity over dry fuels. ...Northern/central Rockies into the Great Basin... As the aforementioned impulse glances by to the north, afternoon heating will help transport the stronger flow aloft towards the surface via a deeply mixed boundary layer. 15-20 mph westerly flow and RH under 20% should become commonplace across much of the northern Great Basin into parts of the central/northern Rockies, where an elevated area remains in place. A critical area has also been maintained for portions of the Snake River Plain, where downslope flow along the lee of the southeast Bitterroot Mountains will augment the ambient flow fields to support 20-25 mph sustained westerly surface winds and 10-20% RH. Here, fuels are also critically dry, which would support wildfire-spread potential given the aforementioned wind/RH conditions. Farther southwest into the Great Basin (i.e. Nevada into far western Utah), localized elevated wind/RH may occur during afternoon peak heating, though the brevity of such conditions precludes a delineation at this time. Given the well-mixed boundary layer, any storms that can develop in the Great Basin will be high-based, with at least a few dry strikes possible over critically dry fuels, potentially supporting ignitions. This is especially the case where dry downbursts may occur, where brief but erratic surface winds may worsen the spread of grass fires from recent ignitions. Nonetheless, storm coverage appears too sparse at this time to warrant an isolated dry thunderstorm delineation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook CORR 1 NWS Storm Prediction Center Norman OK 1144 AM CDT Mon Sep 02 2019 Valid 021700Z - 031200Z CORRECTED FOR AREA TYPE ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN IDAHO... The forecast remains on track with only minor changes needed based on the latest observations and ensemble/deterministic guidance. Please see discussion below for more information on today's fire weather threat. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Mon Sep 02 2019/ ...Synopsis... A well-defined 500 mb impulse, accompanied by 50+ knot winds, will crest an upper-level ridge across the northern Rockies during the afternoon. A response to the surface mass fields will ensue, with breezy, dry conditions prevailing across parts of the central/northern Rockies and northern Great Basin, promoting conditions favorable for wildfire spread. In addition, monsoonal moisture return across parts of the Great Basin may induce isolated thunderstorm activity over dry fuels. ...Northern/central Rockies into the Great Basin... As the aforementioned impulse glances by to the north, afternoon heating will help transport the stronger flow aloft towards the surface via a deeply mixed boundary layer. 15-20 mph westerly flow and RH under 20% should become commonplace across much of the northern Great Basin into parts of the central/northern Rockies, where an elevated area remains in place. A critical area has also been maintained for portions of the Snake River Plain, where downslope flow along the lee of the southeast Bitterroot Mountains will augment the ambient flow fields to support 20-25 mph sustained westerly surface winds and 10-20% RH. Here, fuels are also critically dry, which would support wildfire-spread potential given the aforementioned wind/RH conditions. Farther southwest into the Great Basin (i.e. Nevada into far western Utah), localized elevated wind/RH may occur during afternoon peak heating, though the brevity of such conditions precludes a delineation at this time. Given the well-mixed boundary layer, any storms that can develop in the Great Basin will be high-based, with at least a few dry strikes possible over critically dry fuels, potentially supporting ignitions. This is especially the case where dry downbursts may occur, where brief but erratic surface winds may worsen the spread of grass fires from recent ignitions. Nonetheless, storm coverage appears too sparse at this time to warrant an isolated dry thunderstorm delineation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook CORR 1 NWS Storm Prediction Center Norman OK 1144 AM CDT Mon Sep 02 2019 Valid 021700Z - 031200Z CORRECTED FOR AREA TYPE ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN IDAHO... The forecast remains on track with only minor changes needed based on the latest observations and ensemble/deterministic guidance. Please see discussion below for more information on today's fire weather threat. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Mon Sep 02 2019/ ...Synopsis... A well-defined 500 mb impulse, accompanied by 50+ knot winds, will crest an upper-level ridge across the northern Rockies during the afternoon. A response to the surface mass fields will ensue, with breezy, dry conditions prevailing across parts of the central/northern Rockies and northern Great Basin, promoting conditions favorable for wildfire spread. In addition, monsoonal moisture return across parts of the Great Basin may induce isolated thunderstorm activity over dry fuels. ...Northern/central Rockies into the Great Basin... As the aforementioned impulse glances by to the north, afternoon heating will help transport the stronger flow aloft towards the surface via a deeply mixed boundary layer. 15-20 mph westerly flow and RH under 20% should become commonplace across much of the northern Great Basin into parts of the central/northern Rockies, where an elevated area remains in place. A critical area has also been maintained for portions of the Snake River Plain, where downslope flow along the lee of the southeast Bitterroot Mountains will augment the ambient flow fields to support 20-25 mph sustained westerly surface winds and 10-20% RH. Here, fuels are also critically dry, which would support wildfire-spread potential given the aforementioned wind/RH conditions. Farther southwest into the Great Basin (i.e. Nevada into far western Utah), localized elevated wind/RH may occur during afternoon peak heating, though the brevity of such conditions precludes a delineation at this time. Given the well-mixed boundary layer, any storms that can develop in the Great Basin will be high-based, with at least a few dry strikes possible over critically dry fuels, potentially supporting ignitions. This is especially the case where dry downbursts may occur, where brief but erratic surface winds may worsen the spread of grass fires from recent ignitions. Nonetheless, storm coverage appears too sparse at this time to warrant an isolated dry thunderstorm delineation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1911 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR NORTHEAST MT...NORTHWEST ND
Mesoscale Discussion 1911 NWS Storm Prediction Center Norman OK 1054 AM CDT Mon Sep 02 2019 Areas affected...Far Northeast MT...Northwest ND Concerning...Severe potential...Watch possible Valid 021554Z - 021730Z Probability of Watch Issuance...40 percent SUMMARY...Isolated hail is possible across far northeast MT and northwest ND over the next few hours. Convective trends are being monitored for possible watch issuance. DISCUSSION...Moderate warm-air advection ongoing across the western Dakotas and eastern MT continues to support thunderstorm development across far northeastern MT and northwestern ND. The thermodynamic environment across the region is characterized by stable low-levels with temperatures and dewpoints in the upper 50/low 60s. Even so, steep mid-level lapse rates and warm mid-level temperatures are contributing to an environment with strong buoyancy for parcels rooted near 850-800 mb. The continued warm-air advection is forcing parcels to this level, resulting in persistent thunderstorm development in this region. Strong vertical shear associated with the enhanced westerly flow aloft is helping to organize these storms, resulting in a threat for isolated hail. General expectation is for the low-level jet to shift gradually eastward, with the storms shifting eastward as well. Uncertainty exists regarding severe coverage but trends are being monitored closely. ..Mosier/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...GGW... LAT...LON 49110426 48890245 47970144 47220203 47660494 48700559 49110426 Read more

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