Aggregator

000
ABNT20 KNHC 141700
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Wed Aug 14 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

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

$$
Forecaster Avila

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Wed Aug 14 2019 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... A few dry lightning strikes may occur across portions of south-central Montana this afternoon into the early evening hours (given 0.50-0.75 PWATS, relatively fast storm motions, and a dry sub-cloud layer extending up to 700 mb). Nonetheless, fuels appear too marginally receptive to fire spread, precluding an isolated dry thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... The synoptic pattern will gradually amplify across the CONUS today as a ridge maintains its strength across the Southwest and a broad, low-amplitude trough deepens across the East. This pattern will maintain a belt of enhanced mid-level flow from the Pacific Northwest through the northern Rockies and southeastward through the Midwest. Most of this flow will be displaced from areas of dry fuels across the West, with localized exceptions being portions of eastern Idaho into southwestern Wyoming. Briefly elevated fire weather can be expected in these areas as breezy (15 mph) and dry (15-25% RH) conditions develop during peak heating hours. These conditions are expected to be too brief to necessitate highlights for this outlook period. Elsewhere, relatively weak wind speeds across dry fuels will preclude the need for any highlights today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 14 2019 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Widely scattered severe thunderstorms with very large hail and damaging winds are expected across the central High Plains this afternoon and evening. A few strong storms may be noted across the Gulf Coast to the southern Middle Atlantic. ...Central High Plains this afternoon through tonight... The larger-scale pattern is rather quiescent with a flat ridge over the Rockies and moderate west-northwest flow aloft over the central and northern High Plains. Subtle speed maxima embedded in the flow will crest the ridge and move over the High Plains, the first and most apparent of which will progress from central WY to the central Plains this afternoon. In the wake of a frontal passage and widespread convection last night across the central/southern High Plains, surface ridging extends from western SD to the TX Panhandle/NM border. West of the ridge, boundary-layer dewpoints in the mid 50s have spread west to the Front Range in CO on upslope flow, and slightly lesser moisture extends northward across eastern WY. Steep midlevel lapse rates above a seasonally moist boundary layer with daytime heating will result in a corridor of MLCAPE of 2000-3000 J/kg this afternoon from northeast CO across eastern WY. Forcing for ascent will be rather weak near the higher terrain, so storm coverage within the corridor most favorable for supercells is somewhat in question. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will favor supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete storm interacting with the somewhat greater low-level shear/hodograph curvature expected from western NE into extreme northeast CO along the east edge of the greater buoyancy. There will be some potential for storms to grow upscale into a small MCS tonight, with the more probable corridor for upscale growth centering near western NE and southwest SD where warm advection will be strongest on the nose of a 25-35 kt nocturnal low-level jet, as weak midlevel height falls occur tonight. ...Gulf Coast to the Mid-Atlantic this afternoon... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Gulf Coast and southeastward toward the southeast Atlantic and Mid-Atlantic coasts. The richer moisture/buoyancy (PW greater than 2 inches and MLCAPE greater than 3000 J/kg) are expected along the southern fringe of the lingering clouds this morning, though vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor midlevel lapse rates. ...Northern IN and vicinity this afternoon... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a midlevel trough approaches from WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms could be strong with hail/wind near severe criteria, and a brief/weak tornado cannot be ruled out. ..Thompson/Kerr.. 08/14/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 14 2019 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Widely scattered severe thunderstorms with very large hail and damaging winds are expected across the central High Plains this afternoon and evening. A few strong storms may be noted across the Gulf Coast to the southern Middle Atlantic. ...Central High Plains this afternoon through tonight... The larger-scale pattern is rather quiescent with a flat ridge over the Rockies and moderate west-northwest flow aloft over the central and northern High Plains. Subtle speed maxima embedded in the flow will crest the ridge and move over the High Plains, the first and most apparent of which will progress from central WY to the central Plains this afternoon. In the wake of a frontal passage and widespread convection last night across the central/southern High Plains, surface ridging extends from western SD to the TX Panhandle/NM border. West of the ridge, boundary-layer dewpoints in the mid 50s have spread west to the Front Range in CO on upslope flow, and slightly lesser moisture extends northward across eastern WY. Steep midlevel lapse rates above a seasonally moist boundary layer with daytime heating will result in a corridor of MLCAPE of 2000-3000 J/kg this afternoon from northeast CO across eastern WY. Forcing for ascent will be rather weak near the higher terrain, so storm coverage within the corridor most favorable for supercells is somewhat in question. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will favor supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete storm interacting with the somewhat greater low-level shear/hodograph curvature expected from western NE into extreme northeast CO along the east edge of the greater buoyancy. There will be some potential for storms to grow upscale into a small MCS tonight, with the more probable corridor for upscale growth centering near western NE and southwest SD where warm advection will be strongest on the nose of a 25-35 kt nocturnal low-level jet, as weak midlevel height falls occur tonight. ...Gulf Coast to the Mid-Atlantic this afternoon... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Gulf Coast and southeastward toward the southeast Atlantic and Mid-Atlantic coasts. The richer moisture/buoyancy (PW greater than 2 inches and MLCAPE greater than 3000 J/kg) are expected along the southern fringe of the lingering clouds this morning, though vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor midlevel lapse rates. ...Northern IN and vicinity this afternoon... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a midlevel trough approaches from WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms could be strong with hail/wind near severe criteria, and a brief/weak tornado cannot be ruled out. ..Thompson/Kerr.. 08/14/2019 Read more

000
ABPZ20 KNHC 141228
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Wed Aug 14 2019

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

An elongated low pressure system located more than 1300 miles
west-southwest of the southern tip of the Baja California peninsula
is producing a small area of showers and thunderstorms.
Environmental conditions are expected to be somewhat conducive for
development, and a tropical depression could form over the next few
days before the system reaches cooler waters and upper-level winds
become unfavorable. This disturbance is forecast to move
west-northwestward at 10 to 15 mph during the next couple of days.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...50 percent.

A broad area of low pressure is forecast to form south or
southeast of the southeastern coast of Mexico late this week.
Environmental conditions are expected to be conducive for gradual
development of the system over the weekend while the system moves
generally westward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Berg

000
ABNT20 KNHC 141228
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed Aug 14 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

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

$$
Forecaster Avila

000
ABPZ20 KNHC 141146
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Wed Aug 14 2019

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

An elongated low pressure system located more than 1300 miles
west-southwest of the southern tip of the Baja California peninsula
is producing a small area of showers and thunderstorms.
Environmental conditions are expected to be somewhat conducive for
development, and a tropical depression could form over the next few
days before the system reaches cooler waters and upper-level winds
become unfavorable. This disturbance is forecast to move
west-northwestward at 10 to 15 mph during the next couple of days.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...50 percent.

A broad area of low pressure is forecast to form south or
southeast of the southeastern coast of Mexico late this week.
Environmental conditions are expected to be conducive for gradual
development of the system over the weekend while the system moves
generally westward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Berg

000
ABNT20 KNHC 141116
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed Aug 14 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

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

$$
Forecaster Avila

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0308 AM CDT Wed Aug 14 2019 Valid 171200Z - 221200Z ...DISCUSSION... An amplified upper trough is forecast to move from the northern Rockies toward the upper Great Lakes on Sat/D4, with attendant cold front. Southerly winds ahead of the upper trough will allow for warm advection and destabilization from the central Plains into the upper MS Valley with a few severe storms expected north of NE/IA. However, models are already in disagreement with timing, thus predictability is too low to depict an area. By Sun/D5, the aforementioned upper trough will lift north, allowing rising heights over the Rockies and Plains, resulting in decreasing thunderstorm coverage. Models do hint at a breakdown of the upper ridge across the northern Plains into the Tue/D7 or Wed/D8 period, and this will likely result in severe storms as strong instability will be present over the northern Plains. However, predictability is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0308 AM CDT Wed Aug 14 2019 Valid 171200Z - 221200Z ...DISCUSSION... An amplified upper trough is forecast to move from the northern Rockies toward the upper Great Lakes on Sat/D4, with attendant cold front. Southerly winds ahead of the upper trough will allow for warm advection and destabilization from the central Plains into the upper MS Valley with a few severe storms expected north of NE/IA. However, models are already in disagreement with timing, thus predictability is too low to depict an area. By Sun/D5, the aforementioned upper trough will lift north, allowing rising heights over the Rockies and Plains, resulting in decreasing thunderstorm coverage. Models do hint at a breakdown of the upper ridge across the northern Plains into the Tue/D7 or Wed/D8 period, and this will likely result in severe storms as strong instability will be present over the northern Plains. However, predictability is low. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Wed Aug 14 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL PLAINS INTO THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS... ...SUMMARY... Severe storms are possible from parts of the central Plains into the lower Missouri and mid Mississippi Valleys on Friday. ...Synopsis... A belt of relatively strong westerlies will remain situated over the northern Rockies and Plains, as will a surface low over southwest KS. A warm front is forecast from northern KS into northern MO, and this is where mid 70s F dewpoints and backed surface winds will likely reside. Farther west, moist northeast surface winds will bring a boundary westward into northeast CO. A shortwave trough embedded in the westerlies will move from SD/NE toward the Upper MS Valley, and this will induce increasing southerly 850 mb winds across the central Plains and mid MS Valley, maintaining a feed of unstable air toward the warm front region. ...Central Plains into the Lower MO and mid MS Valleys... Storms, possibly in the form of an MCS, are likely to be ongoing from eastern KS into MO, and may persist into western IL by midday. Strong wind gusts are possible with this activity, but weakening is expected as the low-level jet backs during the day. Any outflow boundaries are expected to modify over KS and MO, with a low-level lapse rate plume extending from the southern Plains into central KS. The greatest theta-e is thus expected to develop over KS during the day, spreading into southeast NE and into northern MO during the evening. Extreme instability is expected over KS, with storms most numerous after 00Z along the east-west boundary from northeast KS into northern MO. Given that this forecast is several days out, the exact corridor is likely to shift, but potentially damaging winds will be possible with a severe MCS Friday evening and overnight. Particularly damaging winds are possible should the more unstable model solutions verify. In addition, the extreme instability along with increasing low-level SRH near the warm front during the evening will likely favor at least isolated supercells with a tornado risk. ..Jewell.. 08/14/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Wed Aug 14 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL PLAINS INTO THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS... ...SUMMARY... Severe storms are possible from parts of the central Plains into the lower Missouri and mid Mississippi Valleys on Friday. ...Synopsis... A belt of relatively strong westerlies will remain situated over the northern Rockies and Plains, as will a surface low over southwest KS. A warm front is forecast from northern KS into northern MO, and this is where mid 70s F dewpoints and backed surface winds will likely reside. Farther west, moist northeast surface winds will bring a boundary westward into northeast CO. A shortwave trough embedded in the westerlies will move from SD/NE toward the Upper MS Valley, and this will induce increasing southerly 850 mb winds across the central Plains and mid MS Valley, maintaining a feed of unstable air toward the warm front region. ...Central Plains into the Lower MO and mid MS Valleys... Storms, possibly in the form of an MCS, are likely to be ongoing from eastern KS into MO, and may persist into western IL by midday. Strong wind gusts are possible with this activity, but weakening is expected as the low-level jet backs during the day. Any outflow boundaries are expected to modify over KS and MO, with a low-level lapse rate plume extending from the southern Plains into central KS. The greatest theta-e is thus expected to develop over KS during the day, spreading into southeast NE and into northern MO during the evening. Extreme instability is expected over KS, with storms most numerous after 00Z along the east-west boundary from northeast KS into northern MO. Given that this forecast is several days out, the exact corridor is likely to shift, but potentially damaging winds will be possible with a severe MCS Friday evening and overnight. Particularly damaging winds are possible should the more unstable model solutions verify. In addition, the extreme instability along with increasing low-level SRH near the warm front during the evening will likely favor at least isolated supercells with a tornado risk. ..Jewell.. 08/14/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Wed Aug 14 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL PLAINS INTO THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS... ...SUMMARY... Severe storms are possible from parts of the central Plains into the lower Missouri and mid Mississippi Valleys on Friday. ...Synopsis... A belt of relatively strong westerlies will remain situated over the northern Rockies and Plains, as will a surface low over southwest KS. A warm front is forecast from northern KS into northern MO, and this is where mid 70s F dewpoints and backed surface winds will likely reside. Farther west, moist northeast surface winds will bring a boundary westward into northeast CO. A shortwave trough embedded in the westerlies will move from SD/NE toward the Upper MS Valley, and this will induce increasing southerly 850 mb winds across the central Plains and mid MS Valley, maintaining a feed of unstable air toward the warm front region. ...Central Plains into the Lower MO and mid MS Valleys... Storms, possibly in the form of an MCS, are likely to be ongoing from eastern KS into MO, and may persist into western IL by midday. Strong wind gusts are possible with this activity, but weakening is expected as the low-level jet backs during the day. Any outflow boundaries are expected to modify over KS and MO, with a low-level lapse rate plume extending from the southern Plains into central KS. The greatest theta-e is thus expected to develop over KS during the day, spreading into southeast NE and into northern MO during the evening. Extreme instability is expected over KS, with storms most numerous after 00Z along the east-west boundary from northeast KS into northern MO. Given that this forecast is several days out, the exact corridor is likely to shift, but potentially damaging winds will be possible with a severe MCS Friday evening and overnight. Particularly damaging winds are possible should the more unstable model solutions verify. In addition, the extreme instability along with increasing low-level SRH near the warm front during the evening will likely favor at least isolated supercells with a tornado risk. ..Jewell.. 08/14/2019 Read more