Aggregator

The Canyon Fire started on August 21, at approximately 1:46 p.m. The fire is 30 miles southeast of Carson City, NV, in Douglas County

No watches are valid as of Fri Aug 23 18:16:03 UTC 2019.

MD 1838 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF SOUTHERN VIRGINIA AND NORTHEASTERN NORTH CAROLINA
Mesoscale Discussion 1838 NWS Storm Prediction Center Norman OK 0114 PM CDT Fri Aug 23 2019 Areas affected...Parts of southern Virginia and northeastern North Carolina Concerning...Severe potential...Watch possible Valid 231814Z - 232015Z Probability of Watch Issuance...40 percent SUMMARY...Increasing thunderstorm development is expected within the next few hours, which may gradually organize and pose an increasing risk for potentially damaging wind gusts by 4-6 PM EDT. Trends are being monitored for the possibility of a severe weather watch. DISCUSSION...A gradual destabilization of the seasonably moist boundary layer within pre-frontal surface troughing is ongoing. Largest mixed-layer CAPE (up to 2000 J/kg), is still confined to portions of the North Carolina piedmont and coastal plain, perhaps into the Hampton Roads area of southeast Virginia, where temperatures have reached or are approaching 90F. However, CAPE appears to be in excess of 1000 J/kg ahead of the southward advancing cold front, across much of the remainder of central/southern Virginia, with insolation likely to contribute to further destabilization during the next few hours. Areas of deepening convective development are now underway, within the the surface troughing (including around the Southern Pines NC vicinity and southeast of Richmond VA, as well as near the southward advancing cold front, across the higher terrain of western Virginia (east/southeast of Hot Springs VA) eastward toward the southern Delmarva Peninsula. It appears that the front may provide the primary focus for increasing thunderstorm development through 20-22Z, perhaps aided by forcing for ascent associated with a low-amplitude mid-level wave progressing east of the central Appalachians. A belt of 30-40 kt westerly mid-level flow (in the 700-500 mb layer) is contributing to modest deep layer shear along this corridor, which could promote the the gradual upscale growth of an organizing cluster of storms posing increasing risk for potentially damaging wind gusts. ..Kerr/Thompson.. 08/23/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...LWX...RAH...RNK... LAT...LON 37777943 37807796 37877650 37897537 37117557 36207543 35507602 35477686 35317859 35447942 35737950 36137907 36597948 37018038 37777943 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

000
ABPZ20 KNHC 231718
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Fri Aug 23 2019

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

The National Hurricane Center is issuing advisories on Tropical
Storm Ivo, located a few hundred miles southwest of the southern
tip of the Baja California peninsula.

A surface trough located about 1100 miles east-southeast of the Big
Island of Hawaii is producing limited shower and thunderstorm
activity. Environmental conditions could become a little more
conducive for some development in the central Pacific basin well to
the east of the Hawaiian Islands in a few days as the system
moves slowly northwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

An area of low pressure is likely to form early next week just
offshore of the west-central Mexico coast near the southern tip of
the Baja California peninsula. Some slow development of this system
is possible thereafter as it moves west to west-northwest at around
10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Latto/Blake

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...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 Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...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 Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...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 Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Fri Aug 23 16:35:01 UTC 2019.

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more

Issued at 900 AM PDT Fri Aug 23 2019 000 WTPZ45 KNHC 231605 TCDEP5 Tropical Storm Ivo Special Discussion Number 10 NWS National Hurricane Center Miami FL EP102019 900 AM PDT Fri Aug 23 2019 An observation at 1430 UTC from Clarion Island, Mexico, indicated sustained winds of 53 kt and a wind gust to 66 kt on that island. Based on this data, a special advisory is being issued with the initial intensity increased to 55 kt. There has been a slight upward adjustment of the forecast intensity through 24 hours to account for the initial wind speed. However, the remainder of the forecast reasoning remains unchanged, and no changes were made to the track for this advisory. FORECAST POSITIONS AND MAX WINDS INIT 23/1600Z 18.9N 115.0W 55 KT 65 MPH 12H 24/0000Z 20.0N 115.7W 50 KT 60 MPH 24H 24/1200Z 21.6N 116.4W 45 KT 50 MPH 36H 25/0000Z 23.1N 117.2W 35 KT 40 MPH 48H 25/1200Z 24.6N 117.9W 30 KT 35 MPH 72H 26/1200Z 27.6N 118.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 27/1200Z...DISSIPATED $$ Forecaster Latto/Blake

5-Day Uncertainty Track last updated Fri, 23 Aug 2019 16:04:33 GMT


Wind Speed Probabilities last updated Fri, 23 Aug 2019 16:04:33 GMT

Issued at 1600 UTC FRI AUG 23 2019 000 FOPZ15 KNHC 231603 PWSEP5 TROPICAL STORM IVO SPECIAL WIND SPEED PROBABILITIES NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102019 1600 UTC FRI AUG 23 2019 AT 1600Z THE CENTER OF TROPICAL STORM IVO WAS LOCATED NEAR LATITUDE 18.9 NORTH...LONGITUDE 115.0 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 55 KTS...65 MPH...100 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z FRI 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE PERIODS TO TO TO TO TO TO TO 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE 12Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT IS GUADALUPE 34 X X( X) X( X) X( X) 4( 4) X( 4) X( 4) ISLA CLARION 34 99 X(99) X(99) X(99) X(99) X(99) X(99) ISLA CLARION 50 66 X(66) X(66) X(66) X(66) X(66) X(66) 20N 115W 34 85 3(88) X(88) X(88) X(88) X(88) X(88) 20N 115W 50 6 3( 9) X( 9) X( 9) X( 9) X( 9) X( 9) 25N 115W 34 X 1( 1) 2( 3) X( 3) 1( 4) X( 4) X( 4) 20N 120W 34 1 1( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) 25N 120W 34 X X( X) 1( 1) 3( 4) 4( 8) X( 8) X( 8) $$ FORECASTER LATTO/BLAKE