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WW 0632 Status Updates
STATUS FOR WATCH 0632 HAS NOT BEEN ISSUED YET Read more

WW 0632 Status Updates
STATUS FOR WATCH 0632 HAS NOT BEEN ISSUED YET Read more

WW 0631 Status Updates
STATUS REPORT ON WW 631 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WSW BIS TO 55 NNE BIS TO 20 NW DVL. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1913 ..MOSIER..09/02/19 ATTN...WFO...BIS... STATUS REPORT FOR WS 631 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC015-031-043-093-103-022140- ND . NORTH DAKOTA COUNTIES INCLUDED ARE BURLEIGH FOSTER KIDDER STUTSMAN WELLS THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

5-Day Uncertainty Track last updated Mon, 02 Sep 2019 20:37:33 GMT


Wind Speed Probabilities last updated Mon, 02 Sep 2019 21:32:14 GMT

Issued at 300 PM MDT Mon Sep 02 2019 000 WTPZ41 KNHC 022036 TCDEP1 Hurricane Juliette Discussion Number 7 NWS National Hurricane Center Miami FL EP112019 300 PM MDT Mon Sep 02 2019 Juliette is clearly on the upswing. A banding eye is present in visible and IR imagery, and satellite intensity estimates around 1800 UTC were all near 65 kt. The IR presentation of the cyclone has continued to improve since then and the initial intensity has been raised to 70 kt, making making Juliette the 5th hurricane of the eastern North Pacific season, and the first hurricane in that basin since July 31. The hurricane has quickly strengthened today and I see no reason why this won't continue for the next 12 to 24 hours. Rapid intensification still seems like a distinct possibility, though the intensity guidance certainly suggests otherwise. It is surprising that none of the guidance shows Juliette strengthening very quickly during the next day or two despite the apparent favorable environment the hurricane is embedded within and the current intensification trend. The NHC forecast remains above all of the intensity models for the first 48 hours, given the impressive structure of the hurricane. Beyond that time, the forecast is again close to the multi-model consensus and shows Juliette weakening quickly as it moves over cooler SSTs and into a dry environment. Juliette has slowed down and the initial motion is now 305/10 kt. There is no change in the forecast reasoning, and Juliette is still generally expected to be steered west-northwestward by an extensive deep-layer ridge located to the north and northeast of the cyclone. The models remain in very good agreement on the forecast of Juliette for the first 3 or 4 days of the forecast, and confidence remains high through that period. The global models then vary on the strength of the ridge and the model spread is notably higher by the end of the forecast. For now, the NHC forecast continues to split the various models and closely follows the multi-model consensus at all times. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 17.2N 113.3W 70 KT 80 MPH 12H 03/0600Z 17.9N 114.4W 80 KT 90 MPH 24H 03/1800Z 18.6N 115.9W 90 KT 105 MPH 36H 04/0600Z 19.1N 117.2W 90 KT 105 MPH 48H 04/1800Z 19.6N 118.7W 85 KT 100 MPH 72H 05/1800Z 21.1N 122.4W 65 KT 75 MPH 96H 06/1800Z 22.5N 127.0W 45 KT 50 MPH 120H 07/1800Z 24.0N 131.0W 35 KT 40 MPH $$ Forecaster Zelinsky

Issued at 2100 UTC MON SEP 02 2019 000 FOPZ11 KNHC 022035 PWSEP1 HURRICANE JULIETTE WIND SPEED PROBABILITIES NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112019 2100 UTC MON SEP 02 2019 AT 2100Z THE CENTER OF HURRICANE JULIETTE WAS LOCATED NEAR LATITUDE 17.2 NORTH...LONGITUDE 113.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 70 KTS...80 MPH...130 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 18Z 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 18Z MON 06Z TUE 18Z TUE 06Z WED 18Z WED 18Z THU 18Z FRI PERIODS TO TO TO TO TO TO TO 06Z TUE 18Z TUE 06Z WED 18Z WED 18Z THU 18Z FRI 18Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ISLA SOCORRO 34 2 2( 4) 1( 5) X( 5) X( 5) X( 5) X( 5) ISLA CLARION 34 96 4(99) X(99) X(99) X(99) X(99) X(99) ISLA CLARION 50 44 39(83) X(83) X(83) X(83) X(83) X(83) ISLA CLARION 64 11 41(52) X(52) X(52) X(52) X(52) X(52) 15N 115W 34 2 3( 5) 2( 7) 1( 8) X( 8) X( 8) X( 8) 20N 115W 34 11 47(58) 6(64) 2(66) X(66) X(66) X(66) 20N 115W 50 1 4( 5) 3( 8) X( 8) X( 8) X( 8) X( 8) 15N 120W 34 X X( X) 3( 3) 1( 4) 2( 6) X( 6) X( 6) 20N 120W 34 X 2( 2) 9(11) 44(55) 34(89) X(89) X(89) 20N 120W 50 X X( X) 1( 1) 12(13) 43(56) X(56) X(56) 20N 120W 64 X X( X) X( X) 4( 4) 26(30) 1(31) X(31) 25N 120W 34 X X( X) X( X) 1( 1) 5( 6) 1( 7) X( 7) 20N 125W 34 X X( X) X( X) X( X) 13(13) 19(32) X(32) 20N 125W 50 X X( X) X( X) X( X) 1( 1) 7( 8) X( 8) 20N 125W 64 X X( X) X( X) X( X) X( X) 2( 2) X( 2) 25N 125W 34 X X( X) X( X) X( X) 2( 2) 8(10) 1(11) 20N 130W 34 X X( X) X( X) X( X) X( X) 3( 3) 4( 7) 25N 130W 34 X X( X) X( X) X( X) X( X) 3( 3) 10(13) $$ FORECASTER ZELINSKY

Issued at 300 PM MDT Mon Sep 02 2019 000 WTPZ31 KNHC 022035 TCPEP1 BULLETIN Hurricane Juliette Advisory Number 7 NWS National Hurricane Center Miami FL EP112019 300 PM MDT Mon Sep 02 2019 ...JULIETTE BECOMES A HURRICANE... ...THE FIFTH ONE OF THE EAST PACIFIC SEASON... SUMMARY OF 300 PM MDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...17.2N 113.3W ABOUT 450 MI...725 KM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 300 PM MDT (2100 UTC), the center of Hurricane Juliette was located near latitude 17.2 North, longitude 113.3 West. Juliette is moving toward the northwest near 10 mph (17 km/h). The hurricane is expected to continue at this forward speed toward the northwest or west-northwest for the next several days. Maximum sustained winds have increased to near 80 mph (130 km/h) with higher gusts. Additional strengthening is anticipated for the next day or two. Weakening is forecast to begin by Thursday. Hurricane-force winds extend outward up to 15 miles (30 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). The estimated minimum central pressure is 987 mb (29.15 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 900 PM MDT. $$ Forecaster Zelinsky

...JULIETTE BECOMES A HURRICANE... ...THE FIFTH ONE OF THE EAST PACIFIC SEASON... As of 3:00 PM MDT Mon Sep 2 the center of Juliette was located near 17.2, -113.3 with movement NW at 10 mph. The minimum central pressure was 987 mb with maximum sustained winds of about 80 mph.

MD 1915 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SOUTHEAST ND...WEST-CENTRAL MN...FAR NORTHEAST SD
Mesoscale Discussion 1915 NWS Storm Prediction Center Norman OK 0334 PM CDT Mon Sep 02 2019 Areas affected...Southeast ND...West-Central MN...Far Northeast SD Concerning...Severe potential...Watch likely Valid 022034Z - 022200Z Probability of Watch Issuance...95 percent SUMMARY...Strengthening MCS across central SD is expected to persist downstream in southeast ND, west-central MN, and far northeast SD. A downstream watch will likely be needed. DISCUSSION...Current storm motion takes the ongoing MCS across central ND to the edge of Severe Thunderstorm Watch 631 before 22Z. Convective inhibition currently remains in place over the downstream environment across southeast ND, west-central MN, and far northeastern SD. However, increasing moisture advection and diurnal heating will contribute to an erosion of at least some of this inhibition. In addition to the weakening convective inhibition and building instability, the strong warm-air advection is expected to persist. All of these factors combined with the organized character of the ongoing MCS suggest the severe threat will continue downstream. Some acceleration of the MCS is also possible along with higher probability for strong wind gusts at the surface. A downstream watch will likely be needed to cover the resulting severe weather threat. ..Mosier/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...FGF...ABR...BIS... LAT...LON 47309893 47729790 46999509 45629493 45419668 46019960 47309893 Read more

Issued at 2100 UTC MON SEP 02 2019 000 WTPZ21 KNHC 022034 TCMEP1 HURRICANE JULIETTE FORECAST/ADVISORY NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112019 2100 UTC MON SEP 02 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 17.2N 113.3W AT 02/2100Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 987 MB MAX SUSTAINED WINDS 70 KT WITH GUSTS TO 85 KT. 64 KT....... 15NE 0SE 0SW 15NW. 50 KT....... 30NE 20SE 0SW 30NW. 34 KT.......110NE 70SE 30SW 80NW. 12 FT SEAS..180NE 150SE 90SW 150NW. 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 17.2N 113.3W AT 02/2100Z AT 02/1800Z CENTER WAS LOCATED NEAR 17.0N 112.9W FORECAST VALID 03/0600Z 17.9N 114.4W MAX WIND 80 KT...GUSTS 100 KT. 64 KT... 20NE 0SE 0SW 20NW. 50 KT... 50NE 30SE 20SW 40NW. 34 KT...110NE 70SE 50SW 80NW. FORECAST VALID 03/1800Z 18.6N 115.9W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 25NE 20SE 15SW 20NW. 50 KT... 50NE 40SE 30SW 50NW. 34 KT...100NE 80SE 70SW 90NW. FORECAST VALID 04/0600Z 19.1N 117.2W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 30NE 25SE 15SW 25NW. 50 KT... 50NE 40SE 40SW 50NW. 34 KT...100NE 90SE 80SW 90NW. FORECAST VALID 04/1800Z 19.6N 118.7W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 30NE 25SE 15SW 25NW. 50 KT... 50NE 40SE 40SW 50NW. 34 KT...100NE 80SE 80SW 90NW. FORECAST VALID 05/1800Z 21.1N 122.4W MAX WIND 65 KT...GUSTS 80 KT. 50 KT... 50NE 40SE 30SW 50NW. 34 KT... 90NE 70SE 60SW 80NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 150 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 06/1800Z 22.5N 127.0W MAX WIND 45 KT...GUSTS 55 KT. OUTLOOK VALID 07/1800Z 24.0N 131.0W MAX WIND 35 KT...GUSTS 45 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.2N 113.3W NEXT ADVISORY AT 03/0300Z $$ FORECASTER ZELINSKY

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... AMENDED TO ADD SIG WIND ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... AMENDED TO ADD SIG WIND ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... AMENDED TO ADD SIG WIND ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

MD 1914 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE MID-ATLANTIC INTO THE NORTHEAST
Mesoscale Discussion 1914 NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Sep 02 2019 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Watch unlikely Valid 021958Z - 022230Z Probability of Watch Issuance...20 percent SUMMARY...Storms are developing along and ahead of a cold front across Upstate New York stretching into central Pennsylvania. Marginally severe wind/hail are possible, and a brief, weak tornado may also be possible where surface winds are backed. DISCUSSION...A broad upper-level trough is moving over Ontario/Quebec today with a mid-level disturbance rotating around the base of it across the eastern Great Lakes into the Northeast. An associated surface cold front is pushing east/southeast across the region with storms developing along/ahead of it currently. Insolation behind storms/showers that moved through earlier have increased MLCAPE to 500-1000+ J/kg as surface temperatures have warmed into the 70s and low 80s F with 65-70 F dewpoints. Buoyancy and instability should continue to increase and also shift eastward with time as the upper-level wave progresses and as heating continues behind the eastward moving showers in New England. Isolated damaging wind is possible given increasing low-level lapse rates and large hail is also possible with effective bulk shear of 30-40 knots. A broken line of storms is expected to develop with a few storms possibly developing ahead of it. These storms will move eastward this afternoon/evening with some weak, transient supercellular structures possible. A brief, weak tornado is possible across portions of southern New England/New York where backed low-level flow exists. Given the marginal and relatively expected isolated severe risk, a watch issuance is unlikely. ..Nauslar/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...OKX...ALY...PHI...BGM...CTP... LAT...LON 40657637 40507695 40377741 40477777 40707794 40957795 41207748 41947596 42677380 43057255 43147212 43157180 43067141 42737122 42237114 41957124 41577196 41447239 41417256 41297304 41207378 40657637 Read more

WW 0631 Status Updates
STATUS REPORT ON WW 631 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 WSW N60 TO 55 WNW DVL. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1913 ..MOSIER..09/02/19 ATTN...WFO...BIS... STATUS REPORT FOR WS 631 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC015-031-043-055-057-059-065-069-083-093-103-022040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE BURLEIGH FOSTER KIDDER MCLEAN MERCER MORTON OLIVER PIERCE SHERIDAN STUTSMAN WELLS THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

MD 1913 CONCERNING SEVERE THUNDERSTORM WATCH 631... FOR CENTRAL ND
Mesoscale Discussion 1913 NWS Storm Prediction Center Norman OK 0247 PM CDT Mon Sep 02 2019 Areas affected...Central ND Concerning...Severe Thunderstorm Watch 631... Valid 021947Z - 022115Z The severe weather threat for Severe Thunderstorm Watch 631 continues. SUMMARY...Large hail and strong wind gusts remain possible with the line of storms moving quickly across central ND. DISCUSSION...Current estimated storm motion on the forward-propagating MCS moving through central ND is 290 degrees at 36 kt. Some increase in forward motion is possible over the next few hours as mid-level flow gradually increases and the system matures. Thus far, the primary threat with the MCS has been large hail, owing to its predominantly elevated character. Moisture advection continues within the downstream air mass but the low-level stratus remains in place. Delayed erosion of this stratus layer has stunted insolation immediately downstream of the MCS across central ND, limiting destabilization (shown well on the 18Z BIS sounding). More thinning of the stratus layer is beginning to occur across southeast ND where temperatures are now in the upper 60s/low 70s. Current expectation is for the MCS to maintain strength as it continues southeastward, perhaps increasing its forward speed. Limited downstream destabilization has likely limited strong wind gusts thus far. However, gusts are expected to become increasingly likely this afternoon as the downstream air mass becomes more favorable for surface-based storms. ..Mosier.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 48300267 48750127 47999804 46339851 46510218 48300267 Read more

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

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