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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Fri Sep 20 2019 Valid 202000Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF THE NORTHERN PLAINS... ...SUMMARY... Scattered severe storms capable of producing wind damage, isolated large hail and a couple tornadoes are possible this afternoon and evening across the northern Plains, with more isolated severe storms possible in parts of the southern High Plains. ...Discussion... No change was made to the severe probabilities. The forecast appears on track. Minor changes were made to the 10-percent thunderstorm probability line across the central Great Lakes and the central FL Peninsula. ..Smith.. 09/20/2019 .PREV DISCUSSION... /ISSUED 1115 AM CDT Fri Sep 20 2019/ ...Northern and Central Plains... Morning water vapor loop shows a large upper trough over the western US, with southwesterly midlevel flow strengthening across the Rockies and High Plains. Several weak impulses are noted from CO northeastward into the Dakotas, with clusters of showers and thunderstorms occurring at this time. The timing and effects of this ongoing convection will result in a rather complex forecast for this afternoon and evening. Activity currently over the western Dakotas is expected to intensify later today as air mass destabilizes and winds aloft strengthen. Occasionally severe storms are expected to affect parts of central and northeast ND into central SD through the mid-late afternoon, with damaging winds, hail, and a couple of tornadoes possible. Later this afternoon, forcing associated with the a stronger shortwave trough will help to initiate thunderstorms from southern MT into eastern WY. These storms will be in a favorable environment for supercells early in the convective life cycle, capable of large hail and a couple of tornadoes. These storms will likely congeal and grow upscale during the evening as they track across parts of NE/SD with a continued threat of damaging winds and hail. ...Southern Plains... A weak remnant outflow boundary extends from near LBB into southern OK. Thunderstorms are expected to develop in vicinity of this boundary this afternoon in a moist and very unstable air mass. Deep-layer shear will be marginal for convective organization. However, convergence along the boundary coupled with slightly enhanced low-level shear may be sufficient for a few supercell storms capable of hail, damaging winds, and perhaps a tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Fri Sep 20 2019 Valid 202000Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF THE NORTHERN PLAINS... ...SUMMARY... Scattered severe storms capable of producing wind damage, isolated large hail and a couple tornadoes are possible this afternoon and evening across the northern Plains, with more isolated severe storms possible in parts of the southern High Plains. ...Discussion... No change was made to the severe probabilities. The forecast appears on track. Minor changes were made to the 10-percent thunderstorm probability line across the central Great Lakes and the central FL Peninsula. ..Smith.. 09/20/2019 .PREV DISCUSSION... /ISSUED 1115 AM CDT Fri Sep 20 2019/ ...Northern and Central Plains... Morning water vapor loop shows a large upper trough over the western US, with southwesterly midlevel flow strengthening across the Rockies and High Plains. Several weak impulses are noted from CO northeastward into the Dakotas, with clusters of showers and thunderstorms occurring at this time. The timing and effects of this ongoing convection will result in a rather complex forecast for this afternoon and evening. Activity currently over the western Dakotas is expected to intensify later today as air mass destabilizes and winds aloft strengthen. Occasionally severe storms are expected to affect parts of central and northeast ND into central SD through the mid-late afternoon, with damaging winds, hail, and a couple of tornadoes possible. Later this afternoon, forcing associated with the a stronger shortwave trough will help to initiate thunderstorms from southern MT into eastern WY. These storms will be in a favorable environment for supercells early in the convective life cycle, capable of large hail and a couple of tornadoes. These storms will likely congeal and grow upscale during the evening as they track across parts of NE/SD with a continued threat of damaging winds and hail. ...Southern Plains... A weak remnant outflow boundary extends from near LBB into southern OK. Thunderstorms are expected to develop in vicinity of this boundary this afternoon in a moist and very unstable air mass. Deep-layer shear will be marginal for convective organization. However, convergence along the boundary coupled with slightly enhanced low-level shear may be sufficient for a few supercell storms capable of hail, damaging winds, and perhaps a tornado. Read more

WW 0654 Status Updates
STATUS FOR WATCH 0654 HAS NOT BEEN ISSUED YET Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z Short-term model guidance has come into better agreement regarding the potential for 15-20 mph west-southwesterly winds to overlap with reduced RH values of 10-20% for a few hours Saturday afternoon across portions of southern CO into northern NM. Have therefore introduced a small elevated area across parts of this region. ..Gleason.. 09/20/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Fri Sep 20 2019/ ...Synopsis... The upper-level trough located over the central/northern Plains should flatten while developing two short-wave troughs that pivot through the region. Meanwhile, ridging will develop over the upper Great Basin. These processes should keep most of the enhanced mid-level flow juxtaposed to the east of areas where fuels are currently receptive, and thus, fire-weather concerns remain low at this time. With that said, there exists some potential for perhaps localized elevated conditions to develop over portions of south-central Colorado/far north-central New Mexico. However, considerable spread is present among various model guidance concerning the RH/wind overlap/potential, and thus no highlights have been included at this time. ...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 0135 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z Short-term model guidance has come into better agreement regarding the potential for 15-20 mph west-southwesterly winds to overlap with reduced RH values of 10-20% for a few hours Saturday afternoon across portions of southern CO into northern NM. Have therefore introduced a small elevated area across parts of this region. ..Gleason.. 09/20/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Fri Sep 20 2019/ ...Synopsis... The upper-level trough located over the central/northern Plains should flatten while developing two short-wave troughs that pivot through the region. Meanwhile, ridging will develop over the upper Great Basin. These processes should keep most of the enhanced mid-level flow juxtaposed to the east of areas where fuels are currently receptive, and thus, fire-weather concerns remain low at this time. With that said, there exists some potential for perhaps localized elevated conditions to develop over portions of south-central Colorado/far north-central New Mexico. However, considerable spread is present among various model guidance concerning the RH/wind overlap/potential, and thus no highlights have been included at this time. ...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 0135 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z Short-term model guidance has come into better agreement regarding the potential for 15-20 mph west-southwesterly winds to overlap with reduced RH values of 10-20% for a few hours Saturday afternoon across portions of southern CO into northern NM. Have therefore introduced a small elevated area across parts of this region. ..Gleason.. 09/20/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Fri Sep 20 2019/ ...Synopsis... The upper-level trough located over the central/northern Plains should flatten while developing two short-wave troughs that pivot through the region. Meanwhile, ridging will develop over the upper Great Basin. These processes should keep most of the enhanced mid-level flow juxtaposed to the east of areas where fuels are currently receptive, and thus, fire-weather concerns remain low at this time. With that said, there exists some potential for perhaps localized elevated conditions to develop over portions of south-central Colorado/far north-central New Mexico. However, considerable spread is present among various model guidance concerning the RH/wind overlap/potential, and thus no highlights have been included at this time. ...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 0135 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z Short-term model guidance has come into better agreement regarding the potential for 15-20 mph west-southwesterly winds to overlap with reduced RH values of 10-20% for a few hours Saturday afternoon across portions of southern CO into northern NM. Have therefore introduced a small elevated area across parts of this region. ..Gleason.. 09/20/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Fri Sep 20 2019/ ...Synopsis... The upper-level trough located over the central/northern Plains should flatten while developing two short-wave troughs that pivot through the region. Meanwhile, ridging will develop over the upper Great Basin. These processes should keep most of the enhanced mid-level flow juxtaposed to the east of areas where fuels are currently receptive, and thus, fire-weather concerns remain low at this time. With that said, there exists some potential for perhaps localized elevated conditions to develop over portions of south-central Colorado/far north-central New Mexico. However, considerable spread is present among various model guidance concerning the RH/wind overlap/potential, and thus no highlights have been included at this time. ...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 0135 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z Short-term model guidance has come into better agreement regarding the potential for 15-20 mph west-southwesterly winds to overlap with reduced RH values of 10-20% for a few hours Saturday afternoon across portions of southern CO into northern NM. Have therefore introduced a small elevated area across parts of this region. ..Gleason.. 09/20/2019 .PREV DISCUSSION... /ISSUED 0100 AM CDT Fri Sep 20 2019/ ...Synopsis... The upper-level trough located over the central/northern Plains should flatten while developing two short-wave troughs that pivot through the region. Meanwhile, ridging will develop over the upper Great Basin. These processes should keep most of the enhanced mid-level flow juxtaposed to the east of areas where fuels are currently receptive, and thus, fire-weather concerns remain low at this time. With that said, there exists some potential for perhaps localized elevated conditions to develop over portions of south-central Colorado/far north-central New Mexico. However, considerable spread is present among various model guidance concerning the RH/wind overlap/potential, and thus no highlights have been included at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Fri Sep 20 18:37:01 UTC 2019.

MD 1988 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR TX CAPROCK VICINITY AND LOW ROLLING PLAINS
Mesoscale Discussion 1988 NWS Storm Prediction Center Norman OK 0135 PM CDT Fri Sep 20 2019 Areas affected...TX Caprock vicinity and Low Rolling Plains Concerning...Severe potential...Watch unlikely Valid 201835Z - 201930Z Probability of Watch Issuance...20 percent SUMMARY...Storm intensity may maximize as developing storms move near and cross the earlier-day outflow boundary draped across parts of the TX Rolling Plains to near the greater Lubbock area. DISCUSSION...Visible satellite imagery shows a swelling cumulus field and scattered thunderstorms initiating from near and south-southwest of Lubbock arcing southeast and east across the TX Rolling Plains. Surface analysis indicates a stationary outflow boundary is oriented similarly to where storms are developing east of Lubbock. KLBB VAD data shows around 30kt south-southwesterly 500mb flow atop backed low-level east-southeasterlies. The latest RAP forecast soundings show modest 700-500mb lapse rates with a very moist profile from the surface through the midlevels. Around 2500 J/kg MLCAPE is currently analyzed. It appears the greatest combination of shear/CAPE is located near the boundary where the hodograph has been augmented and is resulting in 100-200 m2/s^2 effective SRH. Therefore the risk for a supercell or two may focus within the aforementioned corridor along the outflow boundary where a brief supercell tornado could occur later this afternoon. The coverage and magnitude of the severe risk will likely preclude a convective watch issuance but trends will continue to be monitored. ..Smith/Hart.. 09/20/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SJT...LUB...MAF... LAT...LON 33580206 33480126 33340038 32800025 32730114 33110190 33580206 Read more

Issued at 1200 PM MDT Fri Sep 20 2019 000 WTPZ35 KNHC 201813 CCA TCPEP5 BULLETIN Hurricane Lorena Intermediate Advisory Number 13A...Corrected NWS National Hurricane Center Miami FL EP152019 1200 PM MDT Fri Sep 20 2019 corrected initial latitude ...HURRICANE LORENA VERY NEAR THE SOUTHERN PORTION OF THE BAJA CALIFORNIA PENINSULA... ...HURRICANE CONDITIONS SHOULD BEGIN SOON... SUMMARY OF 1200 PM MDT...1800 UTC...INFORMATION ----------------------------------------------- LOCATION...22.9N 109.4W ABOUT 35 MI...55 KM E OF CABO SAN LUCAS MEXICO MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 6 MPH...10 KM/H MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Baja California peninsula from La Paz to Puerto Cortes A Hurricane Watch is in effect for... * East coast of the Baja California peninsula north of La Paz to San Evaristo A Tropical Storm Warning is in effect for... * Puerto Cortes to Cabo San Lazaro A Tropical Storm Watch is in effect for... * East coast of the Baja California peninsula north of San Evaristo to Loreto * West coast of the Baja California peninsula north of Cabo San Lazaro to Puerto San Andresito A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case during the next few hours. Preparations to protect life and property should be rushed to completion. A Hurricane Watch means that hurricane conditions are possible within the watch area, in this case within the next 12 to 24 hours. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within the next 12 to 24 hours. Interests elsewhere in Baja California Sur should monitor the progress of Lorena. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1200 PM MDT (1800 UTC), the center of Hurricane Lorena was located near latitude 22.9 North, longitude 109.4 West. Lorena is now moving toward the west near 6 mph (10 km/h), and a turn toward the west-northwest with some increase in forward speed is expected later today and Saturday. On the forecast track, the center of Lorena will move near or over the southern portion of the Baja California peninsula later today, and then gradually move away from the west coast of the peninsula tonight and Saturday. Maximum sustained winds are near 75 mph (120 km/h) with higher gusts. Some additional strengthening is possible today, but weakening is likely to begin by Saturday night, and Lorena will then either degenerate into a remnant low, or become absorbed by Tropical Storm Mario in a couple of days. Hurricane-force winds extend outward up to 10 miles (20 km) from the center and tropical-storm-force winds extend outward up to 60 miles (95 km). The estimated minimum central pressure is 987 mb (29.15 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Lorena can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP5 and WMO header WTPZ45 KNHC and on the web at www.hurricanes.gov/text/MIATCDEP5.shtml. WIND: Hurricane conditions are expected within the hurricane warning area in the southern Baja California peninsula during the next several hours. Hurricane and tropical storm conditions are possible within the hurricane watch area by Saturday. Tropical storm conditions are possible in the tropical storm watch area by Saturday night. RAINFALL: Lorena is expected to produce rainfall accumulations of 3 to 6 inches, with maximum amounts around 8 inches, across southern Baja California Sur. This rainfall may result in flash flooding. SURF: Swells generated by Lorena will affect portions of the southwestern coast of Mexico and the southern Baja California peninsula during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 300 PM MDT. $$ Forecaster Avila

...HURRICANE LORENA VERY NEAR THE SOUTHERN PORTION OF THE BAJA CALIFORNIA PENINSULA... ...HURRICANE CONDITIONS SHOULD BEGIN SOON... As of 12:00 PM MDT Fri Sep 20 the center of Lorena was located near 22.9, -109.4 with movement W at 6 mph. The minimum central pressure was 987 mb with maximum sustained winds of about 75 mph.

5-Day Uncertainty Track last updated Fri, 20 Sep 2019 18:14:19 GMT


Wind Speed Probabilities last updated Fri, 20 Sep 2019 15:44:54 GMT

MD 1987 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR WESTERN THROUGH CENTRAL NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA
Mesoscale Discussion 1987 NWS Storm Prediction Center Norman OK 1249 PM CDT Fri Sep 20 2019 Areas affected...western through central North Dakota and northwest South Dakota Concerning...Severe potential...Watch possible Valid 201749Z - 201945Z Probability of Watch Issuance...60 percent SUMMARY...A few storms may continue to pose a risk for mainly isolated large hail early this afternoon. The threat for isolated damaging wind and a couple of tornadoes will also increase later this afternoon and evening. DISCUSSION...Early this afternoon thunderstorms continue developing over western ND and northwest SD, primarily within a post-frontal zone of deeper ascent associated with a northeast-moving shortwave trough interacting with a cold front that extends across the western Dakotas. These storms are elevated, but effective bulk shear from 40-45 kt is supporting mid-level rotation, and radar data has indicated occasional large hail. The downstream warm sector is destabilizing with MLCAPE from 1500-2000 J/kg as temperatures warm through the 80s. However, the atmosphere is still capped to surface based parcels. By 20-21Z, convective inhibition should weaken sufficiently for surface based storms to develop along the front. Though mixed storms modes are likely, effective bulk shear from 30-40 kt will support some organized structures including a few supercells and bowing line segments. Damaging wind and large hail should be the main threats. A couple of tornadoes will also be possible, especially with any storm interacting with warm front over northern ND where 0-1 km hodograph size will be somewhat larger. ..Dial/Hart.. 09/20/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...ABR...BIS...UNR... LAT...LON 47970256 48880158 48859952 48239933 47350007 45410163 46090279 47970256 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS INTO IOWA AND OVER NORTHWEST MINNESOTA... ...SUMMARY... Severe storms are possible across parts of the Plains on Saturday, most concentrated from Kansas into Iowa. Severe storms are also expected across northwest Minnesota. Other more isolated activity is possible over parts of the southern High Plains. ...Synopsis... Progressive shortwave trough embedded within a broad upper trough will move northeastward across the Dakotas and into southern Manitoba on Saturday. Its parent upper trough will also gradually move eastward as a second shortwave trough rotates through its base across the Four Corners region. Overall evolution of these features will result in strong mid/upper-level southwesterly flow spreading across the northern/central Plains into the mid/upper MS Valley and Upper Great Lakes. The surface pattern early Saturday will feature a cold front extending from a low centered over the central Manitoba/Ontario border south-southwestward to another low over the southern CO/KS border. Northern portion of this front is expected to progress quickly eastward/southeastward throughout the day, likely reaching the Upper Great Lakes by early Sunday morning. Southern portion of front is also expected to move southeastward, but more slowly than portions farther north. Expectation is for this portion of this front to extend from southwest KS into northern MO by early Sunday morning. Thunderstorms are expected along the length of the front as it interacts with the moist and unstable air mass ahead of it. ...Central Plains into the Mid MS Valley... Highest thunderstorm coverage is expected along the front from KS northeastward into northwest MO/southern IA. In this region, several mechanisms for ascent will overlap, including convergence along front, persistent warm-air advection, and large-scale lift provided within the entrance region of the upper jet. This ascent combined with the moist low-level air mass and moderate vertical shear will support some more organized updrafts and potentially a few supercells. Given the sagging cold front and persistent warm-air advection, storms may have trouble remaining surface based, potentially limiting a more widespread severe threat. Even so, the more organized storms will be capable of large hail, with some instances of very large hail (i.e. greater than 2" in diameter) possible. ...Far Eastern Dakotas across MN into WI... Showers and thunderstorms will likely be ongoing at the beginning of the period, supported by a strong low-level jet. A few of these storms may be strong enough to produce hail. These showers and thunderstorms will drift eastward/northeastward and weaken during the morning as the low-level also shifts eastward. Moisture advection ahead of the approaching front is expected to result in mid to upper 60s across the region by mid-afternoon. Lapse rates are also expected to steepen as cooler mid/upper-level temperatures gradually move into the area while low-level temperatures remain relatively warm from antecedent convection. These thermodynamic conditions coupled with strong mid-level flow aloft result in an environment conditionally supportive of strong to severe thunderstorms. Main deterrents for storm initiation are the warm low-level temperatures (i.e. between 850-700 mb) and the lack of stronger convergence along the front. As such, much of the region will likely struggle to produce deep convection. Most probable location for thunderstorms is across northern MN where the frontal ascent is well correlated with ascent provided by the shortwave trough. Here, a few supercells capable of large hail and strong wind gusts are possible. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Mosier.. 09/20/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS INTO IOWA AND OVER NORTHWEST MINNESOTA... ...SUMMARY... Severe storms are possible across parts of the Plains on Saturday, most concentrated from Kansas into Iowa. Severe storms are also expected across northwest Minnesota. Other more isolated activity is possible over parts of the southern High Plains. ...Synopsis... Progressive shortwave trough embedded within a broad upper trough will move northeastward across the Dakotas and into southern Manitoba on Saturday. Its parent upper trough will also gradually move eastward as a second shortwave trough rotates through its base across the Four Corners region. Overall evolution of these features will result in strong mid/upper-level southwesterly flow spreading across the northern/central Plains into the mid/upper MS Valley and Upper Great Lakes. The surface pattern early Saturday will feature a cold front extending from a low centered over the central Manitoba/Ontario border south-southwestward to another low over the southern CO/KS border. Northern portion of this front is expected to progress quickly eastward/southeastward throughout the day, likely reaching the Upper Great Lakes by early Sunday morning. Southern portion of front is also expected to move southeastward, but more slowly than portions farther north. Expectation is for this portion of this front to extend from southwest KS into northern MO by early Sunday morning. Thunderstorms are expected along the length of the front as it interacts with the moist and unstable air mass ahead of it. ...Central Plains into the Mid MS Valley... Highest thunderstorm coverage is expected along the front from KS northeastward into northwest MO/southern IA. In this region, several mechanisms for ascent will overlap, including convergence along front, persistent warm-air advection, and large-scale lift provided within the entrance region of the upper jet. This ascent combined with the moist low-level air mass and moderate vertical shear will support some more organized updrafts and potentially a few supercells. Given the sagging cold front and persistent warm-air advection, storms may have trouble remaining surface based, potentially limiting a more widespread severe threat. Even so, the more organized storms will be capable of large hail, with some instances of very large hail (i.e. greater than 2" in diameter) possible. ...Far Eastern Dakotas across MN into WI... Showers and thunderstorms will likely be ongoing at the beginning of the period, supported by a strong low-level jet. A few of these storms may be strong enough to produce hail. These showers and thunderstorms will drift eastward/northeastward and weaken during the morning as the low-level also shifts eastward. Moisture advection ahead of the approaching front is expected to result in mid to upper 60s across the region by mid-afternoon. Lapse rates are also expected to steepen as cooler mid/upper-level temperatures gradually move into the area while low-level temperatures remain relatively warm from antecedent convection. These thermodynamic conditions coupled with strong mid-level flow aloft result in an environment conditionally supportive of strong to severe thunderstorms. Main deterrents for storm initiation are the warm low-level temperatures (i.e. between 850-700 mb) and the lack of stronger convergence along the front. As such, much of the region will likely struggle to produce deep convection. Most probable location for thunderstorms is across northern MN where the frontal ascent is well correlated with ascent provided by the shortwave trough. Here, a few supercells capable of large hail and strong wind gusts are possible. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Mosier.. 09/20/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS INTO IOWA AND OVER NORTHWEST MINNESOTA... ...SUMMARY... Severe storms are possible across parts of the Plains on Saturday, most concentrated from Kansas into Iowa. Severe storms are also expected across northwest Minnesota. Other more isolated activity is possible over parts of the southern High Plains. ...Synopsis... Progressive shortwave trough embedded within a broad upper trough will move northeastward across the Dakotas and into southern Manitoba on Saturday. Its parent upper trough will also gradually move eastward as a second shortwave trough rotates through its base across the Four Corners region. Overall evolution of these features will result in strong mid/upper-level southwesterly flow spreading across the northern/central Plains into the mid/upper MS Valley and Upper Great Lakes. The surface pattern early Saturday will feature a cold front extending from a low centered over the central Manitoba/Ontario border south-southwestward to another low over the southern CO/KS border. Northern portion of this front is expected to progress quickly eastward/southeastward throughout the day, likely reaching the Upper Great Lakes by early Sunday morning. Southern portion of front is also expected to move southeastward, but more slowly than portions farther north. Expectation is for this portion of this front to extend from southwest KS into northern MO by early Sunday morning. Thunderstorms are expected along the length of the front as it interacts with the moist and unstable air mass ahead of it. ...Central Plains into the Mid MS Valley... Highest thunderstorm coverage is expected along the front from KS northeastward into northwest MO/southern IA. In this region, several mechanisms for ascent will overlap, including convergence along front, persistent warm-air advection, and large-scale lift provided within the entrance region of the upper jet. This ascent combined with the moist low-level air mass and moderate vertical shear will support some more organized updrafts and potentially a few supercells. Given the sagging cold front and persistent warm-air advection, storms may have trouble remaining surface based, potentially limiting a more widespread severe threat. Even so, the more organized storms will be capable of large hail, with some instances of very large hail (i.e. greater than 2" in diameter) possible. ...Far Eastern Dakotas across MN into WI... Showers and thunderstorms will likely be ongoing at the beginning of the period, supported by a strong low-level jet. A few of these storms may be strong enough to produce hail. These showers and thunderstorms will drift eastward/northeastward and weaken during the morning as the low-level also shifts eastward. Moisture advection ahead of the approaching front is expected to result in mid to upper 60s across the region by mid-afternoon. Lapse rates are also expected to steepen as cooler mid/upper-level temperatures gradually move into the area while low-level temperatures remain relatively warm from antecedent convection. These thermodynamic conditions coupled with strong mid-level flow aloft result in an environment conditionally supportive of strong to severe thunderstorms. Main deterrents for storm initiation are the warm low-level temperatures (i.e. between 850-700 mb) and the lack of stronger convergence along the front. As such, much of the region will likely struggle to produce deep convection. Most probable location for thunderstorms is across northern MN where the frontal ascent is well correlated with ascent provided by the shortwave trough. Here, a few supercells capable of large hail and strong wind gusts are possible. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Mosier.. 09/20/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Sep 20 2019 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KANSAS INTO IOWA AND OVER NORTHWEST MINNESOTA... ...SUMMARY... Severe storms are possible across parts of the Plains on Saturday, most concentrated from Kansas into Iowa. Severe storms are also expected across northwest Minnesota. Other more isolated activity is possible over parts of the southern High Plains. ...Synopsis... Progressive shortwave trough embedded within a broad upper trough will move northeastward across the Dakotas and into southern Manitoba on Saturday. Its parent upper trough will also gradually move eastward as a second shortwave trough rotates through its base across the Four Corners region. Overall evolution of these features will result in strong mid/upper-level southwesterly flow spreading across the northern/central Plains into the mid/upper MS Valley and Upper Great Lakes. The surface pattern early Saturday will feature a cold front extending from a low centered over the central Manitoba/Ontario border south-southwestward to another low over the southern CO/KS border. Northern portion of this front is expected to progress quickly eastward/southeastward throughout the day, likely reaching the Upper Great Lakes by early Sunday morning. Southern portion of front is also expected to move southeastward, but more slowly than portions farther north. Expectation is for this portion of this front to extend from southwest KS into northern MO by early Sunday morning. Thunderstorms are expected along the length of the front as it interacts with the moist and unstable air mass ahead of it. ...Central Plains into the Mid MS Valley... Highest thunderstorm coverage is expected along the front from KS northeastward into northwest MO/southern IA. In this region, several mechanisms for ascent will overlap, including convergence along front, persistent warm-air advection, and large-scale lift provided within the entrance region of the upper jet. This ascent combined with the moist low-level air mass and moderate vertical shear will support some more organized updrafts and potentially a few supercells. Given the sagging cold front and persistent warm-air advection, storms may have trouble remaining surface based, potentially limiting a more widespread severe threat. Even so, the more organized storms will be capable of large hail, with some instances of very large hail (i.e. greater than 2" in diameter) possible. ...Far Eastern Dakotas across MN into WI... Showers and thunderstorms will likely be ongoing at the beginning of the period, supported by a strong low-level jet. A few of these storms may be strong enough to produce hail. These showers and thunderstorms will drift eastward/northeastward and weaken during the morning as the low-level also shifts eastward. Moisture advection ahead of the approaching front is expected to result in mid to upper 60s across the region by mid-afternoon. Lapse rates are also expected to steepen as cooler mid/upper-level temperatures gradually move into the area while low-level temperatures remain relatively warm from antecedent convection. These thermodynamic conditions coupled with strong mid-level flow aloft result in an environment conditionally supportive of strong to severe thunderstorms. Main deterrents for storm initiation are the warm low-level temperatures (i.e. between 850-700 mb) and the lack of stronger convergence along the front. As such, much of the region will likely struggle to produce deep convection. Most probable location for thunderstorms is across northern MN where the frontal ascent is well correlated with ascent provided by the shortwave trough. Here, a few supercells capable of large hail and strong wind gusts are possible. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Mosier.. 09/20/2019 Read more

799
ABPZ20 KNHC 201729
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Fri Sep 20 2019

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

The National Hurricane Center is issuing advisories on Tropical
Storm Kiko, located over the far southwestern part of the basin, on
Tropical Storm Mario, located a few hundred miles south of the
southern tip of the Baja California peninsula, and on Hurricane
Lorena, located very near the southern tip of the Baja California
peninsula.

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

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Forecaster Zelinsky

The U.S. Forest Service’s Arapaho National Forest will be looking for opportunities to continue the Blue Ridge prescribed fire project this fall in the area near Cottonwood Pass between Granby and Hot Sulphur Springs as conditions allow. In the past year, crews have completed burning on 438 acres in the area. This fall, fire managers are looking to burn up to 700 acres over multiple days. Blue Ridge is part of the Wildland-Urban Interface formed by the towns of Granby, Hot Sulphur Springs and the Fraser Valley. Improving conditions in this area is a key component of the Hot Sulphur, Fraser and Grand County Community Wildfire Protection Plans. Learn more about prescribed fire at: https://smokeybear.com/en/about-wildland-fire/benefits-of-fire/prescribed-fires