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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Aug 12 2019 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHEAST IA TO WEST-CENTRAL IN... ...SUMMARY... A few tornadoes, a couple possibly strong, and significant damaging winds will be likely across southeast Iowa through central Illinois, mainly this evening. ...IA/IL/IN... An upgrade to Moderate Risk for tornado and/or wind may become necessary in later outlooks today. A leading MCV is tracking east into eastern IA with a lingering surface cyclone centered over west-central IA. This latter feature should move east into northern IL through this evening. Diffuse convective outflow from remnant leading MCS over southern IL has been shunted across southeast to northwest MO. Nevertheless, air mass recovery is underway north of the boundary into extreme southern IA and west-central IL. Further erosion of the prior cold pool amid cloud breaks should yield at least weak to moderate surface-based buoyancy by late afternoon in IA to northern IL. More robust destabilization is expected farther south where greater unimpeded insolation occurs while a plume of 77-81 F surface dew points is advected north from the Mid-South. Despite relatively warm mid-level temperatures, the very rich boundary-layer moisture and surface heating should yield a plume of large buoyancy with MLCAPE likely reaching 3000-4000 J/kg across much of MO into central/southern IL. Renewed thunderstorm development is probable towards late afternoon near the surface cyclone in southeast IA and during the early evening to the southeast in central IL within a corridor of strengthening low-level warm advection. The initial storms will likely be supercells capable of producing all hazards, given the enhanced low-level shear/hodograph curvature near the cyclone/warm front. Hodographs aloft should tend to favor relatively quick upscale growth, but even semi-discrete supercells will pose a risk for at least a few tornadoes, a couple of which be may strong. A forward-propagating MCS should eventually evolve along the MLCAPE gradient from central IL into central IN where severe wind gusts will remain a threat before weakening overnight. ...TX Panhandle to southern KS/northern OK... A remnant midlevel trough will drift slowly east-northeastward over the TX Panhandle, as a weak cold front moves slowly southeastward from KS/CO. Surface heating and deep mixing will result in inverted-v profiles along and south of the front, and will support the potential for isolated strong downburst winds. Convection will tend to develop east-northeastward tonight along the front, with strong downdrafts still possible in an environment of lingering large CAPE/DCAPE. ...ME... A midlevel trough over James Bay will pivot east-southeastward to Maine overnight. In advance of this trough, a weak pre-frontal trough at the surface and band of weak ascent will provide a focus for thunderstorm development this afternoon. Though moisture and lapse rates will be modest, increasing deep-layer westerly shear and surface heating on the south edge of the thicker clouds could support storms capable of producing isolated damaging gusts and marginally severe hail. ...Dakotas... Widespread clouds and rain are spreading slowly eastward across the eastern Dakotas in association with a couple of diffuse MCVs from overnight convection. A little clearing of clouds and surface heating will be possible from west to east this afternoon, in advance of a larger-scale trough moving east-southeastward from MT to ND. Isolated thunderstorm development and a low-end severe threat will be possible this afternoon if sufficient near-surface destabilization occurs, given enough vertical shear for organized storms. ..Grams/Dean.. 08/12/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Aug 12 2019 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHEAST IA TO WEST-CENTRAL IN... ...SUMMARY... A few tornadoes, a couple possibly strong, and significant damaging winds will be likely across southeast Iowa through central Illinois, mainly this evening. ...IA/IL/IN... An upgrade to Moderate Risk for tornado and/or wind may become necessary in later outlooks today. A leading MCV is tracking east into eastern IA with a lingering surface cyclone centered over west-central IA. This latter feature should move east into northern IL through this evening. Diffuse convective outflow from remnant leading MCS over southern IL has been shunted across southeast to northwest MO. Nevertheless, air mass recovery is underway north of the boundary into extreme southern IA and west-central IL. Further erosion of the prior cold pool amid cloud breaks should yield at least weak to moderate surface-based buoyancy by late afternoon in IA to northern IL. More robust destabilization is expected farther south where greater unimpeded insolation occurs while a plume of 77-81 F surface dew points is advected north from the Mid-South. Despite relatively warm mid-level temperatures, the very rich boundary-layer moisture and surface heating should yield a plume of large buoyancy with MLCAPE likely reaching 3000-4000 J/kg across much of MO into central/southern IL. Renewed thunderstorm development is probable towards late afternoon near the surface cyclone in southeast IA and during the early evening to the southeast in central IL within a corridor of strengthening low-level warm advection. The initial storms will likely be supercells capable of producing all hazards, given the enhanced low-level shear/hodograph curvature near the cyclone/warm front. Hodographs aloft should tend to favor relatively quick upscale growth, but even semi-discrete supercells will pose a risk for at least a few tornadoes, a couple of which be may strong. A forward-propagating MCS should eventually evolve along the MLCAPE gradient from central IL into central IN where severe wind gusts will remain a threat before weakening overnight. ...TX Panhandle to southern KS/northern OK... A remnant midlevel trough will drift slowly east-northeastward over the TX Panhandle, as a weak cold front moves slowly southeastward from KS/CO. Surface heating and deep mixing will result in inverted-v profiles along and south of the front, and will support the potential for isolated strong downburst winds. Convection will tend to develop east-northeastward tonight along the front, with strong downdrafts still possible in an environment of lingering large CAPE/DCAPE. ...ME... A midlevel trough over James Bay will pivot east-southeastward to Maine overnight. In advance of this trough, a weak pre-frontal trough at the surface and band of weak ascent will provide a focus for thunderstorm development this afternoon. Though moisture and lapse rates will be modest, increasing deep-layer westerly shear and surface heating on the south edge of the thicker clouds could support storms capable of producing isolated damaging gusts and marginally severe hail. ...Dakotas... Widespread clouds and rain are spreading slowly eastward across the eastern Dakotas in association with a couple of diffuse MCVs from overnight convection. A little clearing of clouds and surface heating will be possible from west to east this afternoon, in advance of a larger-scale trough moving east-southeastward from MT to ND. Isolated thunderstorm development and a low-end severe threat will be possible this afternoon if sufficient near-surface destabilization occurs, given enough vertical shear for organized storms. ..Grams/Dean.. 08/12/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1114 AM CDT Mon Aug 12 2019 Valid 121700Z - 131200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes made. Please see below for details. ..Squitieri.. 08/12/2019 .PREV DISCUSSION... /ISSUED 0712 AM CDT Mon Aug 12 2019/ ...Synopsis... Fire weather concerns will be minimal today. A mid-level trough over the northern Rockies will weaken and eject, leaving behind weaker and more zonally oriented mid-level flow across the CONUS. Mid-level flow will become minimal across dry areas of the western U.S. Outside of areas of locally elevated fire weather in Wyoming and vicinity, the quiet overall pattern indicates that no highlights will be needed for this outlook. ...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 1114 AM CDT Mon Aug 12 2019 Valid 121700Z - 131200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes made. Please see below for details. ..Squitieri.. 08/12/2019 .PREV DISCUSSION... /ISSUED 0712 AM CDT Mon Aug 12 2019/ ...Synopsis... Fire weather concerns will be minimal today. A mid-level trough over the northern Rockies will weaken and eject, leaving behind weaker and more zonally oriented mid-level flow across the CONUS. Mid-level flow will become minimal across dry areas of the western U.S. Outside of areas of locally elevated fire weather in Wyoming and vicinity, the quiet overall pattern indicates that no highlights will be needed for this outlook. ...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 1114 AM CDT Mon Aug 12 2019 Valid 121700Z - 131200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes made. Please see below for details. ..Squitieri.. 08/12/2019 .PREV DISCUSSION... /ISSUED 0712 AM CDT Mon Aug 12 2019/ ...Synopsis... Fire weather concerns will be minimal today. A mid-level trough over the northern Rockies will weaken and eject, leaving behind weaker and more zonally oriented mid-level flow across the CONUS. Mid-level flow will become minimal across dry areas of the western U.S. Outside of areas of locally elevated fire weather in Wyoming and vicinity, the quiet overall pattern indicates that no highlights will be needed for this outlook. ...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 1114 AM CDT Mon Aug 12 2019 Valid 121700Z - 131200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes made. Please see below for details. ..Squitieri.. 08/12/2019 .PREV DISCUSSION... /ISSUED 0712 AM CDT Mon Aug 12 2019/ ...Synopsis... Fire weather concerns will be minimal today. A mid-level trough over the northern Rockies will weaken and eject, leaving behind weaker and more zonally oriented mid-level flow across the CONUS. Mid-level flow will become minimal across dry areas of the western U.S. Outside of areas of locally elevated fire weather in Wyoming and vicinity, the quiet overall pattern indicates that no highlights will be needed for this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

The area closure for the Verde Fire was lifted August 10 at 7:00am.The lightning caused Verde Fire was reported on Saturday, August 3rd after thunderstorms passed through the area. The fire is burning on the east side of the Verde River, near Black Mesa, approximately two miles northeast of Fort McDowell Reservation lands, and four miles east of the community of Rio Verde. The fire is burning in grass and brush in a remote area with limited road access for fire

5-Day Uncertainty Track last updated Mon, 12 Aug 2019 14:37:25 GMT


Wind Speed Probabilities last updated Mon, 12 Aug 2019 15:24:18 GMT

Issued at 900 AM MDT Mon Aug 12 2019 000 WTPZ44 KNHC 121433 TCDEP4 Tropical Storm Henriette Discussion Number 3 NWS National Hurricane Center Miami FL EP092019 900 AM MDT Mon Aug 12 2019 Henriette is a sheared tropical cyclone, with microwave and first-light visible satellite imagery revealing a low level center that is near the northeastern edge of the deep convection. The overall presentation of the cyclone has changed little over the past several hours, and therefore the initial intensity is being held at 35 kt. This is in agreement with an earlier ASCAT pass showing a very small area of 30-35 kt winds over the northwestern portion of the circulation. The initial motion is 295/10 kt. Henriette is expected to continue this general motion for the next 24 hours as it is steered by a mid-level ridge that extends from northern Mexico to the north of the cyclone. A turn to the west is expected on Tuesday as the system weakens and becomes steered by the low-level flow. The official forecast is slightly south of the previous one through 24 hours, due to a more southward initial position. Beyond 24 hours, the official forecast is very near the previous one, and near the middle of the consensus aids. Northeasterly shear and dry air over the northern portion of the cyclone should continue to keep the low level center near the edge of the deep convection into tonight, preventing any further strengthening. By 24 hours, the cyclone is forecast to cross the 26 C SST isotherm and move into a more stable airmass. This should cause the cyclone to lose its convection and weaken on Tuesday, with the system likely becoming a remnant low by Tuesday night. The official intensity forecast is close to the previous one, and is in agreement with the various dynamical and consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 12/1500Z 19.7N 112.2W 35 KT 40 MPH 12H 13/0000Z 20.2N 113.9W 35 KT 40 MPH 24H 13/1200Z 20.9N 116.1W 30 KT 35 MPH 36H 14/0000Z 21.4N 118.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 14/1200Z...DISSIPATED $$ Forecaster Latto/Pasch

Issued at 1500 UTC MON AUG 12 2019 000 FOPZ14 KNHC 121432 PWSEP4 TROPICAL STORM HENRIETTE WIND SPEED PROBABILITIES NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092019 1500 UTC MON AUG 12 2019 AT 1500Z THE CENTER OF TROPICAL STORM HENRIETTE WAS LOCATED NEAR LATITUDE 19.7 NORTH...LONGITUDE 112.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 35 KTS...40 MPH...65 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 MON 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 MON 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI PERIODS TO TO TO TO TO TO TO 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI 12Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 20N 115W 34 2 16(18) 1(19) X(19) X(19) X(19) X(19) 20N 115W 50 X 3( 3) X( 3) X( 3) X( 3) X( 3) X( 3) $$ FORECASTER LATTO/PASCH

Issued at 900 AM MDT Mon Aug 12 2019 933 WTPZ34 KNHC 121432 TCPEP4 BULLETIN Tropical Storm Henriette Advisory Number 3 NWS National Hurricane Center Miami FL EP092019 900 AM MDT Mon Aug 12 2019 ...HENRIETTE MAINTAINS INTENSITY BUT IS EXPECTED TO WEAKEN BY TUESDAY... SUMMARY OF 900 AM MDT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...19.7N 112.2W ABOUT 265 MI...430 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 900 AM MDT (1500 UTC), the center of Tropical Storm Henriette was located near latitude 19.7 North, longitude 112.2 West. Henriette is moving toward the west-northwest near 12 mph (19 km/h) and this general motion is expected to continue for the next couple of days. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Henriette is expected to begin weakening by Tuesday and degenerate into a remnant low by Tuesday night. Tropical-storm-force winds extend outward up to 35 miles (55 km) from the center. The estimated minimum central pressure is 1005 mb (29.68 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 300 PM MDT. $$ Forecaster Latto/Pasch

...HENRIETTE MAINTAINS INTENSITY BUT IS EXPECTED TO WEAKEN BY TUESDAY... As of 9:00 AM MDT Mon Aug 12 the center of Henriette was located near 19.7, -112.2 with movement WNW at 12 mph. The minimum central pressure was 1005 mb with maximum sustained winds of about 40 mph.

Issued at 1500 UTC MON AUG 12 2019 000 WTPZ24 KNHC 121431 TCMEP4 TROPICAL STORM HENRIETTE FORECAST/ADVISORY NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092019 1500 UTC MON AUG 12 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. TROPICAL STORM CENTER LOCATED NEAR 19.7N 112.2W AT 12/1500Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT. 34 KT....... 0NE 0SE 30SW 30NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 19.7N 112.2W AT 12/1500Z AT 12/1200Z CENTER WAS LOCATED NEAR 19.5N 111.7W FORECAST VALID 13/0000Z 20.2N 113.9W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 0NE 0SE 30SW 30NW. FORECAST VALID 13/1200Z 20.9N 116.1W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 14/0000Z 21.4N 118.8W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 14/1200Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.7N 112.2W NEXT ADVISORY AT 12/2100Z $$ FORECASTER LATTO/PASCH

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Mon Aug 12 2019 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST IA INTO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...IA/IL this afternoon/evening... A well-defined MCV is moving eastward over western IA this morning, per reflectivity mosaics and VWP observations of 50-60 kt midlevel flow at OAX/DMX. The associated MCS and low-level cold pool have weakened since 09z, though convective outflow appears to extend farther south into KS/MO than most model guidance. Thus, recovery of the boundary layer into IA is a primary concern for this afternoon. Assuming surface heating in cloud breaks by early-mid afternoon and erosion of the morning cold pool, boundary-layer dewpoints in the low-mid 70s will contribute to MLCAPE in excess of 2000 J/kg east of the surface low and south of the warm front in IA. Renewed thunderstorm development is probable by mid afternoon near the surface low, with storms expected to subsequently move/develop east-southeastward along the warm front into IL by this evening. The initial storms will likely be supercells capable of producing tornadoes and damaging winds, given the enhanced low-level shear/hodograph curvature near the cyclone/warm front, along the north edge of the unstable warm sector. Upscale growth into a cluster is expected by this evening from southeast IA/northeast MO into northwest and central IL, where damaging winds will become the more prominent threat into tonight. The MCV/cyclone will begin to move east of the surface warm sector late tonight, which should result in gradual weakening of the storms across IN. The northward extent and magnitude of the severe/tornado threat this afternoon will depend heavily on the degree of recovery from the ongoing/weakening MCS, which is still a bit uncertain. ...TX Panhandle this afternoon to southeast KS tonight... A remnant midlevel trough will drift slowly east-northeastward over the TX Panhandle today, as a weak cold front moves slowly southeastward from KS/CO. Surface heating and deep mixing will result in inverted-v profiles along and south of the front, and will support the potential for isolated strong downburst winds. Convection will tend to develop east-northeastward tonight along the front, with strong downdrafts still possible in an environment of lingering large CAPE/DCAPE. ...Maine this afternoon... A midlevel trough over James Bay will pivot east-southeastward to Maine overnight. In advance of this trough, a weak pre-frontal trough at the surface and band of weak ascent will provide a focus for thunderstorm development this afternoon. Though moisture and lapse rates will be modest, increasing deep-layer westerly shear and surface heating on the south edge of the thicker clouds could support storms capable of producing isolated damaging gusts. ...Dakotas this afternoon/evening... Widespread clouds and rain are spreading slowly eastward across the eastern Dakotas in association with a couple of diffuse MCVs from overnight convection. A little clearing of clouds and surface heating will be possible from west to east this afternoon, in advance of a larger-scale trough moving east-southeastward from MT to ND. Isolated thunderstorm development and a low-end severe threat will be possible this afternoon if sufficient near-surface destabilization occurs, given enough vertical shear for organized storms. ..Thompson/Kerr.. 08/12/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Mon Aug 12 2019 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST IA INTO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...IA/IL this afternoon/evening... A well-defined MCV is moving eastward over western IA this morning, per reflectivity mosaics and VWP observations of 50-60 kt midlevel flow at OAX/DMX. The associated MCS and low-level cold pool have weakened since 09z, though convective outflow appears to extend farther south into KS/MO than most model guidance. Thus, recovery of the boundary layer into IA is a primary concern for this afternoon. Assuming surface heating in cloud breaks by early-mid afternoon and erosion of the morning cold pool, boundary-layer dewpoints in the low-mid 70s will contribute to MLCAPE in excess of 2000 J/kg east of the surface low and south of the warm front in IA. Renewed thunderstorm development is probable by mid afternoon near the surface low, with storms expected to subsequently move/develop east-southeastward along the warm front into IL by this evening. The initial storms will likely be supercells capable of producing tornadoes and damaging winds, given the enhanced low-level shear/hodograph curvature near the cyclone/warm front, along the north edge of the unstable warm sector. Upscale growth into a cluster is expected by this evening from southeast IA/northeast MO into northwest and central IL, where damaging winds will become the more prominent threat into tonight. The MCV/cyclone will begin to move east of the surface warm sector late tonight, which should result in gradual weakening of the storms across IN. The northward extent and magnitude of the severe/tornado threat this afternoon will depend heavily on the degree of recovery from the ongoing/weakening MCS, which is still a bit uncertain. ...TX Panhandle this afternoon to southeast KS tonight... A remnant midlevel trough will drift slowly east-northeastward over the TX Panhandle today, as a weak cold front moves slowly southeastward from KS/CO. Surface heating and deep mixing will result in inverted-v profiles along and south of the front, and will support the potential for isolated strong downburst winds. Convection will tend to develop east-northeastward tonight along the front, with strong downdrafts still possible in an environment of lingering large CAPE/DCAPE. ...Maine this afternoon... A midlevel trough over James Bay will pivot east-southeastward to Maine overnight. In advance of this trough, a weak pre-frontal trough at the surface and band of weak ascent will provide a focus for thunderstorm development this afternoon. Though moisture and lapse rates will be modest, increasing deep-layer westerly shear and surface heating on the south edge of the thicker clouds could support storms capable of producing isolated damaging gusts. ...Dakotas this afternoon/evening... Widespread clouds and rain are spreading slowly eastward across the eastern Dakotas in association with a couple of diffuse MCVs from overnight convection. A little clearing of clouds and surface heating will be possible from west to east this afternoon, in advance of a larger-scale trough moving east-southeastward from MT to ND. Isolated thunderstorm development and a low-end severe threat will be possible this afternoon if sufficient near-surface destabilization occurs, given enough vertical shear for organized storms. ..Thompson/Kerr.. 08/12/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Mon Aug 12 2019 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST IA INTO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...IA/IL this afternoon/evening... A well-defined MCV is moving eastward over western IA this morning, per reflectivity mosaics and VWP observations of 50-60 kt midlevel flow at OAX/DMX. The associated MCS and low-level cold pool have weakened since 09z, though convective outflow appears to extend farther south into KS/MO than most model guidance. Thus, recovery of the boundary layer into IA is a primary concern for this afternoon. Assuming surface heating in cloud breaks by early-mid afternoon and erosion of the morning cold pool, boundary-layer dewpoints in the low-mid 70s will contribute to MLCAPE in excess of 2000 J/kg east of the surface low and south of the warm front in IA. Renewed thunderstorm development is probable by mid afternoon near the surface low, with storms expected to subsequently move/develop east-southeastward along the warm front into IL by this evening. The initial storms will likely be supercells capable of producing tornadoes and damaging winds, given the enhanced low-level shear/hodograph curvature near the cyclone/warm front, along the north edge of the unstable warm sector. Upscale growth into a cluster is expected by this evening from southeast IA/northeast MO into northwest and central IL, where damaging winds will become the more prominent threat into tonight. The MCV/cyclone will begin to move east of the surface warm sector late tonight, which should result in gradual weakening of the storms across IN. The northward extent and magnitude of the severe/tornado threat this afternoon will depend heavily on the degree of recovery from the ongoing/weakening MCS, which is still a bit uncertain. ...TX Panhandle this afternoon to southeast KS tonight... A remnant midlevel trough will drift slowly east-northeastward over the TX Panhandle today, as a weak cold front moves slowly southeastward from KS/CO. Surface heating and deep mixing will result in inverted-v profiles along and south of the front, and will support the potential for isolated strong downburst winds. Convection will tend to develop east-northeastward tonight along the front, with strong downdrafts still possible in an environment of lingering large CAPE/DCAPE. ...Maine this afternoon... A midlevel trough over James Bay will pivot east-southeastward to Maine overnight. In advance of this trough, a weak pre-frontal trough at the surface and band of weak ascent will provide a focus for thunderstorm development this afternoon. Though moisture and lapse rates will be modest, increasing deep-layer westerly shear and surface heating on the south edge of the thicker clouds could support storms capable of producing isolated damaging gusts. ...Dakotas this afternoon/evening... Widespread clouds and rain are spreading slowly eastward across the eastern Dakotas in association with a couple of diffuse MCVs from overnight convection. A little clearing of clouds and surface heating will be possible from west to east this afternoon, in advance of a larger-scale trough moving east-southeastward from MT to ND. Isolated thunderstorm development and a low-end severe threat will be possible this afternoon if sufficient near-surface destabilization occurs, given enough vertical shear for organized storms. ..Thompson/Kerr.. 08/12/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Mon Aug 12 2019 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM SOUTHEAST IA INTO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...IA/IL this afternoon/evening... A well-defined MCV is moving eastward over western IA this morning, per reflectivity mosaics and VWP observations of 50-60 kt midlevel flow at OAX/DMX. The associated MCS and low-level cold pool have weakened since 09z, though convective outflow appears to extend farther south into KS/MO than most model guidance. Thus, recovery of the boundary layer into IA is a primary concern for this afternoon. Assuming surface heating in cloud breaks by early-mid afternoon and erosion of the morning cold pool, boundary-layer dewpoints in the low-mid 70s will contribute to MLCAPE in excess of 2000 J/kg east of the surface low and south of the warm front in IA. Renewed thunderstorm development is probable by mid afternoon near the surface low, with storms expected to subsequently move/develop east-southeastward along the warm front into IL by this evening. The initial storms will likely be supercells capable of producing tornadoes and damaging winds, given the enhanced low-level shear/hodograph curvature near the cyclone/warm front, along the north edge of the unstable warm sector. Upscale growth into a cluster is expected by this evening from southeast IA/northeast MO into northwest and central IL, where damaging winds will become the more prominent threat into tonight. The MCV/cyclone will begin to move east of the surface warm sector late tonight, which should result in gradual weakening of the storms across IN. The northward extent and magnitude of the severe/tornado threat this afternoon will depend heavily on the degree of recovery from the ongoing/weakening MCS, which is still a bit uncertain. ...TX Panhandle this afternoon to southeast KS tonight... A remnant midlevel trough will drift slowly east-northeastward over the TX Panhandle today, as a weak cold front moves slowly southeastward from KS/CO. Surface heating and deep mixing will result in inverted-v profiles along and south of the front, and will support the potential for isolated strong downburst winds. Convection will tend to develop east-northeastward tonight along the front, with strong downdrafts still possible in an environment of lingering large CAPE/DCAPE. ...Maine this afternoon... A midlevel trough over James Bay will pivot east-southeastward to Maine overnight. In advance of this trough, a weak pre-frontal trough at the surface and band of weak ascent will provide a focus for thunderstorm development this afternoon. Though moisture and lapse rates will be modest, increasing deep-layer westerly shear and surface heating on the south edge of the thicker clouds could support storms capable of producing isolated damaging gusts. ...Dakotas this afternoon/evening... Widespread clouds and rain are spreading slowly eastward across the eastern Dakotas in association with a couple of diffuse MCVs from overnight convection. A little clearing of clouds and surface heating will be possible from west to east this afternoon, in advance of a larger-scale trough moving east-southeastward from MT to ND. Isolated thunderstorm development and a low-end severe threat will be possible this afternoon if sufficient near-surface destabilization occurs, given enough vertical shear for organized storms. ..Thompson/Kerr.. 08/12/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0712 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... Weak, quasi-zonal mid-level flow will continue across the northern tier of the CONUS D2/Tuesday. Flow at the surface and aloft will be minimal across dry areas of the West outside of localized, terrain-favored areas. With the lack of major synoptic features traversing the West, fire weather conditions will be minimal. No highlights will be introduced for this outlook. ..Cook.. 08/12/2019 ...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 0712 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... Weak, quasi-zonal mid-level flow will continue across the northern tier of the CONUS D2/Tuesday. Flow at the surface and aloft will be minimal across dry areas of the West outside of localized, terrain-favored areas. With the lack of major synoptic features traversing the West, fire weather conditions will be minimal. No highlights will be introduced for this outlook. ..Cook.. 08/12/2019 ...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 0712 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... Weak, quasi-zonal mid-level flow will continue across the northern tier of the CONUS D2/Tuesday. Flow at the surface and aloft will be minimal across dry areas of the West outside of localized, terrain-favored areas. With the lack of major synoptic features traversing the West, fire weather conditions will be minimal. No highlights will be introduced for this outlook. ..Cook.. 08/12/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more