Aggregator

Issued at 0900 UTC SUN SEP 01 2019 000 FOPZ11 KNHC 010832 PWSEP1 TROPICAL STORM JULIETTE WIND SPEED PROBABILITIES NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112019 0900 UTC SUN SEP 01 2019 AT 0900Z THE CENTER OF TROPICAL STORM JULIETTE WAS LOCATED NEAR LATITUDE 13.2 NORTH...LONGITUDE 107.6 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 40 KTS...45 MPH...75 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 06Z SUN 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 06Z SUN 18Z SUN 06Z MON 18Z MON 06Z TUE 06Z WED 06Z THU PERIODS TO TO TO TO TO TO TO 18Z SUN 06Z MON 18Z MON 06Z TUE 06Z WED 06Z THU 06Z FRI FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 15N 110W 34 51 34(85) X(85) X(85) X(85) X(85) X(85) 15N 110W 50 4 26(30) 1(31) X(31) X(31) X(31) X(31) 15N 110W 64 X 3( 3) X( 3) X( 3) X( 3) X( 3) X( 3) 20N 110W 34 X 2( 2) 3( 5) 1( 6) 1( 7) X( 7) X( 7) ISLA SOCORRO 34 X 5( 5) 7(12) 4(16) 1(17) X(17) X(17) ISLA CLARION 34 X 2( 2) 25(27) 46(73) 8(81) 1(82) X(82) ISLA CLARION 50 X X( X) 2( 2) 30(32) 9(41) X(41) X(41) ISLA CLARION 64 X X( X) X( X) 13(13) 6(19) X(19) X(19) 15N 115W 34 X 3( 3) 14(17) 10(27) 3(30) 1(31) X(31) 15N 115W 50 X X( X) 1( 1) 3( 4) X( 4) X( 4) X( 4) 20N 115W 34 X X( X) 7( 7) 18(25) 18(43) 2(45) X(45) 20N 115W 50 X X( X) X( X) 2( 2) 6( 8) X( 8) X( 8) 20N 115W 64 X X( X) X( X) X( X) 3( 3) X( 3) X( 3) 15N 120W 34 X X( X) X( X) 1( 1) 5( 6) 5(11) X(11) 20N 120W 34 X X( X) X( X) 1( 1) 24(25) 40(65) 6(71) 20N 120W 50 X X( X) X( X) X( X) 3( 3) 27(30) 4(34) 20N 120W 64 X X( X) X( X) X( X) 2( 2) 12(14) 2(16) 25N 120W 34 X X( X) X( X) X( X) X( X) 3( 3) 2( 5) 20N 125W 34 X X( X) X( X) X( X) X( X) 7( 7) 23(30) 20N 125W 50 X X( X) X( X) X( X) X( X) 2( 2) 7( 9) 20N 125W 64 X X( X) X( X) X( X) X( X) X( X) 3( 3) 25N 125W 34 X X( X) X( X) X( X) X( X) 1( 1) 8( 9) 20N 130W 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) $$ FORECASTER STEWART

Issued at 300 AM MDT Sun Sep 01 2019 000 WTPZ41 KNHC 010832 TCDEP1 Tropical Storm Juliette Discussion Number 1 NWS National Hurricane Center Miami FL EP112019 300 AM MDT Sun Sep 01 2019 Earlier scatterometer surface wind data around 0400 UTC indicate that the low pressure system located about 400 nmi south-southwest of Manzanillo, Mexico, had become better defined and that tropical-storm-force winds were occurring in the northern semicircle. More specifically, an ASCAT-A pass revealed peak surface winds of 42 kt, which could have been slightly rain inflated, and an ASCAT-C pass showed peak winds of 39 kt. Based on a blend of these wind data, the low has been upgraded to a 40-kt tropical storm, the tenth tropical storm of the 2019 eastern North Pacific hurricane season. Juliette's initial motion estimate is an uncertain 310/06 kt. The advisory position is an average of the locations of the mid- and low-level circulation centers, in anticipation of the low-level center noted in the ASCAT-C wind data developing closer to the recent bursts of central deep convection. Otherwise, the track forecast is pretty straight-forward with the NHC model guidance in good agreement on maintaining the deep-layer ridge to the north of Juliette throughout the forecast period. This steering pattern should result in the cyclone moving slowly northwestward today, followed by a turn toward the west-northwest with an increase in forward speed on Monday, with a west-northwestward motion continuing through 120 hours. The NHC forecast track lies close to the tightly packed consensus models HCCA and TVCE. Juliette is expected to remain within a favorable environment for intensification to occur over the next 48-72 hours or so, which is characterized by low vertical wind shear of less than 10 kt, a moist mid-level environment, and sea-surface temperatures (SST) of 28-29 deg C. Therefore, the official intensity forecast calls for steady strengthening, with Juliette expected to become a hurricane on Monday. By 96 hours, the cyclone will be moving over SSTs around 26 deg C and cooler, which should induce gradual weakening. The NHC intensity forecast is above the consensus intensity models HCCA and IVCN, and is close to a blend of the statistical SHIPS intensity models and the dynamical HWRF model. FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 13.2N 107.6W 40 KT 45 MPH 12H 01/1800Z 14.5N 109.4W 45 KT 50 MPH 24H 02/0600Z 15.7N 111.5W 55 KT 65 MPH 36H 02/1800Z 16.7N 113.5W 65 KT 75 MPH 48H 03/0600Z 17.6N 115.2W 75 KT 85 MPH 72H 04/0600Z 18.9N 118.0W 75 KT 85 MPH 96H 05/0600Z 20.0N 121.0W 70 KT 80 MPH 120H 06/0600Z 21.8N 124.8W 55 KT 65 MPH $$ Forecaster Stewart

Issued at 0900 UTC SUN SEP 01 2019 000 WTPZ21 KNHC 010831 TCMEP1 TROPICAL STORM JULIETTE FORECAST/ADVISORY NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112019 0900 UTC SUN SEP 01 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. TROPICAL STORM CENTER LOCATED NEAR 13.2N 107.6W AT 01/0900Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 6 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1004 MB MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT. 34 KT....... 70NE 0SE 0SW 60NW. 12 FT SEAS.. 75NE 0SE 0SW 0NW. 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 13.2N 107.6W AT 01/0900Z AT 01/0600Z CENTER WAS LOCATED NEAR 13.0N 107.4W FORECAST VALID 01/1800Z 14.5N 109.4W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 70NE 50SE 0SW 60NW. FORECAST VALID 02/0600Z 15.7N 111.5W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 20NE 0SE 0SW 20NW. 34 KT... 70NE 50SE 0SW 60NW. FORECAST VALID 02/1800Z 16.7N 113.5W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 15NE 0SE 0SW 15NW. 50 KT... 30NE 20SE 0SW 30NW. 34 KT... 70NE 50SE 40SW 60NW. FORECAST VALID 03/0600Z 17.6N 115.2W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 15NE 0SE 0SW 15NW. 50 KT... 30NE 20SE 0SW 30NW. 34 KT... 70NE 50SE 40SW 60NW. FORECAST VALID 04/0600Z 18.9N 118.0W MAX WIND 75 KT...GUSTS 90 KT. 50 KT... 40NE 30SE 20SW 40NW. 34 KT... 90NE 70SE 50SW 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 05/0600Z 20.0N 121.0W MAX WIND 70 KT...GUSTS 85 KT. OUTLOOK VALID 06/0600Z 21.8N 124.8W MAX WIND 55 KT...GUSTS 65 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.2N 107.6W NEXT ADVISORY AT 01/1500Z $$ FORECASTER STEWART

Issued at 300 AM MDT Sun Sep 01 2019 000 WTPZ31 KNHC 010831 TCPEP1 BULLETIN Tropical Storm Juliette Advisory Number 1 NWS National Hurricane Center Miami FL EP112019 300 AM MDT Sun Sep 01 2019 ...NEW TROPICAL STORM FORMS WELL TO THE SOUTHWEST OF MEXICO... ...EXPECTED TO BECOME A HURRICANE ON MONDAY... SUMMARY OF 300 AM MDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...13.2N 107.6W ABOUT 455 MI...735 KM SSW OF MANZANILLO MEXICO ABOUT 685 MI...1105 KM SSE OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 7 MPH...11 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 300 AM MDT (0900 UTC), the center of Tropical Storm Juliette was located near latitude 13.2 North, longitude 107.6 West. Juliette is moving toward the northwest near 7 mph (11 km/h), and this general motion is expected to continue today. A turn toward the west-northwest with an increase in forward speed is expected by Monday and continuing into Wednesday. Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Strengthening is forecast during the next few days, and Juliette is expected to become a hurricane on Monday. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. The estimated minimum central pressure is 1004 mb (29.65 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 900 AM MDT. $$ Forecaster Stewart

...NEW TROPICAL STORM FORMS WELL TO THE SOUTHWEST OF MEXICO... ...EXPECTED TO BECOME A HURRICANE ON MONDAY... As of 3:00 AM MDT Sun Sep 1 the center of Juliette was located near 13.2, -107.6 with movement NW at 7 mph. The minimum central pressure was 1004 mb with maximum sustained winds of about 45 mph.

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0325 AM CDT Sun Sep 01 2019 Valid 041200Z - 091200Z ...DISCUSSION... The extended period will feature a mid-level anticyclone centered over the southern High Plains through the first half before model show this feature weakening by next weekend. A cold front is forecast to move through the Northeast on Wednesday (day 4) with the southwest portion of this boundary becoming nebulous over the south-central U.S. A drier airmass in its wake will tend to limit the magnitude of destabilization later in the week near westerlies over the north-central states. Severe potential seems largely dependent on the eventual track of Hurricane Dorian. Based on National Hurricane Center forecast guidance, it is possible a tornado risk could develop during the early half of the extended period over the coastal Carolinas. However, large uncertainty in this scenario precludes introducing a risk area. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0325 AM CDT Sun Sep 01 2019 Valid 041200Z - 091200Z ...DISCUSSION... The extended period will feature a mid-level anticyclone centered over the southern High Plains through the first half before model show this feature weakening by next weekend. A cold front is forecast to move through the Northeast on Wednesday (day 4) with the southwest portion of this boundary becoming nebulous over the south-central U.S. A drier airmass in its wake will tend to limit the magnitude of destabilization later in the week near westerlies over the north-central states. Severe potential seems largely dependent on the eventual track of Hurricane Dorian. Based on National Hurricane Center forecast guidance, it is possible a tornado risk could develop during the early half of the extended period over the coastal Carolinas. However, large uncertainty in this scenario precludes introducing a risk area. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0325 AM CDT Sun Sep 01 2019 Valid 041200Z - 091200Z ...DISCUSSION... The extended period will feature a mid-level anticyclone centered over the southern High Plains through the first half before model show this feature weakening by next weekend. A cold front is forecast to move through the Northeast on Wednesday (day 4) with the southwest portion of this boundary becoming nebulous over the south-central U.S. A drier airmass in its wake will tend to limit the magnitude of destabilization later in the week near westerlies over the north-central states. Severe potential seems largely dependent on the eventual track of Hurricane Dorian. Based on National Hurricane Center forecast guidance, it is possible a tornado risk could develop during the early half of the extended period over the coastal Carolinas. However, large uncertainty in this scenario precludes introducing a risk area. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sun Sep 01 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHERN ILLINOIS...EASTERN WISCONSIN...AND PARTS OF LOWER MICHIGAN... ...SUMMARY... Severe thunderstorms are possible across the western and central Great Lakes on Tuesday. ...Synopsis... A mid-level trough and associated speed max will move from the Upper Midwest eastward across the Great Lakes and into southeastern Canada on Tuesday into Tuesday night. A mid-level anticyclone will remain situated over the Four Corners while Hurricane Dorian slowly approaches the Southeast United States. In the low levels, a cold front is forecast to move southeast across the Midwest and into the lower Great Lakes. ...Great Lakes... Ongoing storms are likely in the morning across the Upper Midwest as a southwesterly LLJ and warm advection regime promote moisture transport and ascent in portions of MN/WI and the western U.P. of MI. A severe risk may accompany this activity mainly in the form of isolated damaging gusts. The northeastern extent of an elevated mixed layer with associated capping will probably overspread parts of the middle MS Valley during the day. Isolated diurnal storms are possible along the front with a hail/wind risk. Farther northeast, the magnitude of destabilization is highly dependent on the convective evolution of a possible MCS moving through the western Great Lakes during the morning. Wind fields will likely strengthen across the destabilizing warm sector during the day which will favor organized storm structures including the possibility for supercells and bowing segments. Refinements in severe probabilities will likely be needed due to mesoscale dependencies influencing the severe thunderstorm outlook. ...FL Peninsula (Hurricane Dorian)... Uncertainty remains regarding the eventual track of Hurricane Dorian as it moves into the Gulf Stream waters east of the FL Peninsula Monday night into Tuesday morning. If the northeast quadrant were to overspread the FL Peninsula on Tuesday and/or Tuesday night, then a risk for potential tornadoes would include those areas. At this time, uncertainty is too high to include low-severe probabilities. Please refer to the National Hurricane Center for the latest guidance regarding the forecast track of Hurricane Dorian. ..Smith.. 09/01/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sun Sep 01 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHERN ILLINOIS...EASTERN WISCONSIN...AND PARTS OF LOWER MICHIGAN... ...SUMMARY... Severe thunderstorms are possible across the western and central Great Lakes on Tuesday. ...Synopsis... A mid-level trough and associated speed max will move from the Upper Midwest eastward across the Great Lakes and into southeastern Canada on Tuesday into Tuesday night. A mid-level anticyclone will remain situated over the Four Corners while Hurricane Dorian slowly approaches the Southeast United States. In the low levels, a cold front is forecast to move southeast across the Midwest and into the lower Great Lakes. ...Great Lakes... Ongoing storms are likely in the morning across the Upper Midwest as a southwesterly LLJ and warm advection regime promote moisture transport and ascent in portions of MN/WI and the western U.P. of MI. A severe risk may accompany this activity mainly in the form of isolated damaging gusts. The northeastern extent of an elevated mixed layer with associated capping will probably overspread parts of the middle MS Valley during the day. Isolated diurnal storms are possible along the front with a hail/wind risk. Farther northeast, the magnitude of destabilization is highly dependent on the convective evolution of a possible MCS moving through the western Great Lakes during the morning. Wind fields will likely strengthen across the destabilizing warm sector during the day which will favor organized storm structures including the possibility for supercells and bowing segments. Refinements in severe probabilities will likely be needed due to mesoscale dependencies influencing the severe thunderstorm outlook. ...FL Peninsula (Hurricane Dorian)... Uncertainty remains regarding the eventual track of Hurricane Dorian as it moves into the Gulf Stream waters east of the FL Peninsula Monday night into Tuesday morning. If the northeast quadrant were to overspread the FL Peninsula on Tuesday and/or Tuesday night, then a risk for potential tornadoes would include those areas. At this time, uncertainty is too high to include low-severe probabilities. Please refer to the National Hurricane Center for the latest guidance regarding the forecast track of Hurricane Dorian. ..Smith.. 09/01/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sun Sep 01 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHERN ILLINOIS...EASTERN WISCONSIN...AND PARTS OF LOWER MICHIGAN... ...SUMMARY... Severe thunderstorms are possible across the western and central Great Lakes on Tuesday. ...Synopsis... A mid-level trough and associated speed max will move from the Upper Midwest eastward across the Great Lakes and into southeastern Canada on Tuesday into Tuesday night. A mid-level anticyclone will remain situated over the Four Corners while Hurricane Dorian slowly approaches the Southeast United States. In the low levels, a cold front is forecast to move southeast across the Midwest and into the lower Great Lakes. ...Great Lakes... Ongoing storms are likely in the morning across the Upper Midwest as a southwesterly LLJ and warm advection regime promote moisture transport and ascent in portions of MN/WI and the western U.P. of MI. A severe risk may accompany this activity mainly in the form of isolated damaging gusts. The northeastern extent of an elevated mixed layer with associated capping will probably overspread parts of the middle MS Valley during the day. Isolated diurnal storms are possible along the front with a hail/wind risk. Farther northeast, the magnitude of destabilization is highly dependent on the convective evolution of a possible MCS moving through the western Great Lakes during the morning. Wind fields will likely strengthen across the destabilizing warm sector during the day which will favor organized storm structures including the possibility for supercells and bowing segments. Refinements in severe probabilities will likely be needed due to mesoscale dependencies influencing the severe thunderstorm outlook. ...FL Peninsula (Hurricane Dorian)... Uncertainty remains regarding the eventual track of Hurricane Dorian as it moves into the Gulf Stream waters east of the FL Peninsula Monday night into Tuesday morning. If the northeast quadrant were to overspread the FL Peninsula on Tuesday and/or Tuesday night, then a risk for potential tornadoes would include those areas. At this time, uncertainty is too high to include low-severe probabilities. Please refer to the National Hurricane Center for the latest guidance regarding the forecast track of Hurricane Dorian. ..Smith.. 09/01/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0125 AM CDT Sun Sep 01 2019 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN IDAHO... ...Synopsis... A mature embedded impulse will traverse the northern Rockies along the crest of a fortified upper-level ridge on Day 2/Monday. Stronger flow aloft will glance the central/northern Rockies and northern Great Basin areas, inducing a surface mass response which will promote very breezy and dry conditions favorable for wildfire spread. ...Northern Great Basin into the central/northern Rockies... Widespread 15-20 mph sustained west-southwesterly winds, coincident with 10-20% RH, are expected to occur by afternoon across much of Wyoming, westward into Idaho and far southern Montana, and continue past sunset, where an elevated delineation was added. An additional downslope component of surface flow along the lee of the Bitterroot Range will also encourage sustained westerly winds of at least 20-25 mph (perhaps with higher gusts) across parts of the Snake River Plain, atop critically dry fuels, where a critical area was added. At least locally critical conditions may also be observed in terrain favoring locations east of the Snake River Plain into the Great Divide basin. However, the lack of widespread stronger flow across these areas lends too low of confidence to expand the critical area eastward at this time, though conditions will be monitored for a possible upgrade in later outlooks. ..Squitieri.. 09/01/2019 ...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 0125 AM CDT Sun Sep 01 2019 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN IDAHO... ...Synopsis... A mature embedded impulse will traverse the northern Rockies along the crest of a fortified upper-level ridge on Day 2/Monday. Stronger flow aloft will glance the central/northern Rockies and northern Great Basin areas, inducing a surface mass response which will promote very breezy and dry conditions favorable for wildfire spread. ...Northern Great Basin into the central/northern Rockies... Widespread 15-20 mph sustained west-southwesterly winds, coincident with 10-20% RH, are expected to occur by afternoon across much of Wyoming, westward into Idaho and far southern Montana, and continue past sunset, where an elevated delineation was added. An additional downslope component of surface flow along the lee of the Bitterroot Range will also encourage sustained westerly winds of at least 20-25 mph (perhaps with higher gusts) across parts of the Snake River Plain, atop critically dry fuels, where a critical area was added. At least locally critical conditions may also be observed in terrain favoring locations east of the Snake River Plain into the Great Divide basin. However, the lack of widespread stronger flow across these areas lends too low of confidence to expand the critical area eastward at this time, though conditions will be monitored for a possible upgrade in later outlooks. ..Squitieri.. 09/01/2019 ...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 0125 AM CDT Sun Sep 01 2019 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN IDAHO... ...Synopsis... A mature embedded impulse will traverse the northern Rockies along the crest of a fortified upper-level ridge on Day 2/Monday. Stronger flow aloft will glance the central/northern Rockies and northern Great Basin areas, inducing a surface mass response which will promote very breezy and dry conditions favorable for wildfire spread. ...Northern Great Basin into the central/northern Rockies... Widespread 15-20 mph sustained west-southwesterly winds, coincident with 10-20% RH, are expected to occur by afternoon across much of Wyoming, westward into Idaho and far southern Montana, and continue past sunset, where an elevated delineation was added. An additional downslope component of surface flow along the lee of the Bitterroot Range will also encourage sustained westerly winds of at least 20-25 mph (perhaps with higher gusts) across parts of the Snake River Plain, atop critically dry fuels, where a critical area was added. At least locally critical conditions may also be observed in terrain favoring locations east of the Snake River Plain into the Great Divide basin. However, the lack of widespread stronger flow across these areas lends too low of confidence to expand the critical area eastward at this time, though conditions will be monitored for a possible upgrade in later outlooks. ..Squitieri.. 09/01/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Sun Sep 01 2019 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NORTH DAKOTA SOUTHEASTWARD ACROSS MINNESOTA AND INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest Monday and Monday night. ...Upper Midwest... An intensifying mid-level shortwave trough will move quickly from the southern Canadian Rockies east-southeastward to the Red River during the period. In the low levels, a warm front will advance northeastward through parts of the Dakotas and southern MN and a cold front will sweep eastward across the Dakotas during the latter half of the period. A cluster of showers/thunderstorms is possible during the morning associated with warm advection over the mid Missouri Valley. As forcing for ascent increases during the afternoon, storm development will become likely in areas initially farther northwest near a surface low forecast to develop east near the international border. A very unstable airmass is progged by models by late afternoon over the warm sector (3000+ J/kg MLCAPE) with strong effective shear. Details concerning the convective evolution of a cluster of storms evolving into a possible bow are unclear at this time. If confidence increases in later outlook updates, a significant-wind highlight may be included, in addition to higher wind probabilities. Upscale growth is likely by the evening into the overnight with storms moving southeast in the vicinity of the warm front into southeast MN/WI late. ...Southern New England vicinity... A mid-level trough initially extending from James Bay southward into the southern Appalachians will move east and deamplify and eventually reach the New England coast by daybreak Tuesday. A belt of moderate southwesterly flow moving through the base of the trough will encompass the Northeast into northern portions of the Mid-Atlantic states. Widespread clouds and scattered showers/thunderstorms are forecast to be ongoing Monday morning over the Adirondacks and northern New England. This area of convection and related cloud debris is forecast to move east during the day. Forecast models indicate a possibility for pockets of diurnal heating over southern New England with stronger heating/destabilization forecast farther south across PA/NJ. With at least weak destabilization forecast (250-500 J/kg MLCAPE) across southern New England and shear supportive of some storm organization, the favorable timing of peak heating will support storm intensification primarily during the 2pm-8pm EDT period. As a result, included a relatively confined area of 5-percent severe probabilities (due to wind) across southern New England extending into portions of PA/NJ. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Smith.. 09/01/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Sun Sep 01 2019 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NORTH DAKOTA SOUTHEASTWARD ACROSS MINNESOTA AND INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest Monday and Monday night. ...Upper Midwest... An intensifying mid-level shortwave trough will move quickly from the southern Canadian Rockies east-southeastward to the Red River during the period. In the low levels, a warm front will advance northeastward through parts of the Dakotas and southern MN and a cold front will sweep eastward across the Dakotas during the latter half of the period. A cluster of showers/thunderstorms is possible during the morning associated with warm advection over the mid Missouri Valley. As forcing for ascent increases during the afternoon, storm development will become likely in areas initially farther northwest near a surface low forecast to develop east near the international border. A very unstable airmass is progged by models by late afternoon over the warm sector (3000+ J/kg MLCAPE) with strong effective shear. Details concerning the convective evolution of a cluster of storms evolving into a possible bow are unclear at this time. If confidence increases in later outlook updates, a significant-wind highlight may be included, in addition to higher wind probabilities. Upscale growth is likely by the evening into the overnight with storms moving southeast in the vicinity of the warm front into southeast MN/WI late. ...Southern New England vicinity... A mid-level trough initially extending from James Bay southward into the southern Appalachians will move east and deamplify and eventually reach the New England coast by daybreak Tuesday. A belt of moderate southwesterly flow moving through the base of the trough will encompass the Northeast into northern portions of the Mid-Atlantic states. Widespread clouds and scattered showers/thunderstorms are forecast to be ongoing Monday morning over the Adirondacks and northern New England. This area of convection and related cloud debris is forecast to move east during the day. Forecast models indicate a possibility for pockets of diurnal heating over southern New England with stronger heating/destabilization forecast farther south across PA/NJ. With at least weak destabilization forecast (250-500 J/kg MLCAPE) across southern New England and shear supportive of some storm organization, the favorable timing of peak heating will support storm intensification primarily during the 2pm-8pm EDT period. As a result, included a relatively confined area of 5-percent severe probabilities (due to wind) across southern New England extending into portions of PA/NJ. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Smith.. 09/01/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Sun Sep 01 2019 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NORTH DAKOTA SOUTHEASTWARD ACROSS MINNESOTA AND INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest Monday and Monday night. ...Upper Midwest... An intensifying mid-level shortwave trough will move quickly from the southern Canadian Rockies east-southeastward to the Red River during the period. In the low levels, a warm front will advance northeastward through parts of the Dakotas and southern MN and a cold front will sweep eastward across the Dakotas during the latter half of the period. A cluster of showers/thunderstorms is possible during the morning associated with warm advection over the mid Missouri Valley. As forcing for ascent increases during the afternoon, storm development will become likely in areas initially farther northwest near a surface low forecast to develop east near the international border. A very unstable airmass is progged by models by late afternoon over the warm sector (3000+ J/kg MLCAPE) with strong effective shear. Details concerning the convective evolution of a cluster of storms evolving into a possible bow are unclear at this time. If confidence increases in later outlook updates, a significant-wind highlight may be included, in addition to higher wind probabilities. Upscale growth is likely by the evening into the overnight with storms moving southeast in the vicinity of the warm front into southeast MN/WI late. ...Southern New England vicinity... A mid-level trough initially extending from James Bay southward into the southern Appalachians will move east and deamplify and eventually reach the New England coast by daybreak Tuesday. A belt of moderate southwesterly flow moving through the base of the trough will encompass the Northeast into northern portions of the Mid-Atlantic states. Widespread clouds and scattered showers/thunderstorms are forecast to be ongoing Monday morning over the Adirondacks and northern New England. This area of convection and related cloud debris is forecast to move east during the day. Forecast models indicate a possibility for pockets of diurnal heating over southern New England with stronger heating/destabilization forecast farther south across PA/NJ. With at least weak destabilization forecast (250-500 J/kg MLCAPE) across southern New England and shear supportive of some storm organization, the favorable timing of peak heating will support storm intensification primarily during the 2pm-8pm EDT period. As a result, included a relatively confined area of 5-percent severe probabilities (due to wind) across southern New England extending into portions of PA/NJ. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Smith.. 09/01/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 01 2019 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OH VALLEY...NORTHERN/CENTRAL PLAINS...AND SOUTHERN/CENTRAL AZ... ...SUMMARY... Isolated severe storms may occur mainly this afternoon across parts of the Ohio Valley, this evening/tonight across portions of the northern/central Plains, and this afternoon/evening over parts of southern/central Arizona. ...Ohio Valley... Within broadly cyclonic flow over eastern Canada and the Great Lakes, a weak shortwave trough will move across parts of the OH Valley today. Modest ascent associated with this feature should encourage at least scattered storm development by the afternoon from eastern IN into northern KY and OH. This convection should then spread eastward across parts of WV into western PA through the early evening. Even though mid-level lapse rates will remain modest, diurnal heating will contribute to around 1000-2000 J/kg of MLCAPE across most of this region by this afternoon. A veering wind profile in low levels combined with around 20-30 kt of mid-level west-southwesterly flow may support occasional storm organization. Small multicells/clusters capable of producing isolated strong to damaging winds appear to be the main threat. This risk should quickly diminish with eastward extent into PA by late evening as instability wanes. ...Northern/Central Plains... Upper ridging will remain prominent across much of the northern/central Plains through the period. An upper trough/low over BC will move eastward into AB and gradually erode the upper ridge over the northern Rockies and vicinity late tonight. At the surface, a low will develop eastward across central/eastern MT from this evening through early Monday morning. An EML with steep mid-level lapse rates will gradually overspread much of the northern/central Plains though tonight. Greater low-level moisture will likely remain confined along/south of a surface boundary that will be located near the SD/NE border through this evening. Considerable uncertainty remains regarding possible convective initiation during the day, as subsidence associated with the upper ridge will probably tend to limit overall storm coverage across the northern/central Plains. A southerly low-level jet should strengthen to around 30-40 kt across western KS into central NE in the 00-06Z time frame. Warm air advection and related lift may support at least isolated storm development this evening across parts of western/central NE and vicinity. Although any storms that develop will probably be slightly elevated, steep mid-level lapse rates and rich low-level moisture will result in strong MUCAPE across this area, potentially in excess of 3000 J/kg. Around 35-45 kt of effective bulk shear will likely promote rotating updrafts with these storms, and isolated large hail may occur with any elevated supercells that form initially. Farther north, a strengthening south-southwesterly low-level jet late in the period (06-12Z) may encourage isolated convection to develop over northeastern MT/southern SK and subsequently spread southeastward along an instability gradient into parts of western/central ND early Monday morning. Overall coverage still remains uncertain, but there appears to be enough of a convective precipitation signal in short-term guidance to support inclusion of 5% probabilities for isolated instances of large hail occurring with elevated strong to severe storms given the strong shear that will be present. ...Southern/Central Arizona... An upper high will remain centered over the Four Corners region today. Orographic lift should be the main driver of isolated to widely scattered convection that should develop by early afternoon across the higher terrain of western NM and southern/central AZ. However, unlike the past couple of days, around 20 kt of easterly flow at 500 mb may prove sufficient to move these storms off the higher terrain and into lower elevations of southern/central AZ through the evening. A deeply mixed boundary layer is expected to be in place across this area, which will encourage strong/gusty downdraft winds potentially producing isolated damage. Marginally severe hail may also occur with more discrete initial development. These storms should move westward through the evening posing mainly a wind threat before eventually weakening as convective inhibition slowly increases. ...Florida... Strong low-level shear and outer rain bands associated with Hurricane Dorian are forecast to remain generally offshore and to the east of the southern/central FL Peninsula through the period. See the latest advisories from the National Hurricane Center for more information on other hazards associated with Hurricane Dorian. ..Gleason/Squitieri.. 09/01/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 01 2019 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OH VALLEY...NORTHERN/CENTRAL PLAINS...AND SOUTHERN/CENTRAL AZ... ...SUMMARY... Isolated severe storms may occur mainly this afternoon across parts of the Ohio Valley, this evening/tonight across portions of the northern/central Plains, and this afternoon/evening over parts of southern/central Arizona. ...Ohio Valley... Within broadly cyclonic flow over eastern Canada and the Great Lakes, a weak shortwave trough will move across parts of the OH Valley today. Modest ascent associated with this feature should encourage at least scattered storm development by the afternoon from eastern IN into northern KY and OH. This convection should then spread eastward across parts of WV into western PA through the early evening. Even though mid-level lapse rates will remain modest, diurnal heating will contribute to around 1000-2000 J/kg of MLCAPE across most of this region by this afternoon. A veering wind profile in low levels combined with around 20-30 kt of mid-level west-southwesterly flow may support occasional storm organization. Small multicells/clusters capable of producing isolated strong to damaging winds appear to be the main threat. This risk should quickly diminish with eastward extent into PA by late evening as instability wanes. ...Northern/Central Plains... Upper ridging will remain prominent across much of the northern/central Plains through the period. An upper trough/low over BC will move eastward into AB and gradually erode the upper ridge over the northern Rockies and vicinity late tonight. At the surface, a low will develop eastward across central/eastern MT from this evening through early Monday morning. An EML with steep mid-level lapse rates will gradually overspread much of the northern/central Plains though tonight. Greater low-level moisture will likely remain confined along/south of a surface boundary that will be located near the SD/NE border through this evening. Considerable uncertainty remains regarding possible convective initiation during the day, as subsidence associated with the upper ridge will probably tend to limit overall storm coverage across the northern/central Plains. A southerly low-level jet should strengthen to around 30-40 kt across western KS into central NE in the 00-06Z time frame. Warm air advection and related lift may support at least isolated storm development this evening across parts of western/central NE and vicinity. Although any storms that develop will probably be slightly elevated, steep mid-level lapse rates and rich low-level moisture will result in strong MUCAPE across this area, potentially in excess of 3000 J/kg. Around 35-45 kt of effective bulk shear will likely promote rotating updrafts with these storms, and isolated large hail may occur with any elevated supercells that form initially. Farther north, a strengthening south-southwesterly low-level jet late in the period (06-12Z) may encourage isolated convection to develop over northeastern MT/southern SK and subsequently spread southeastward along an instability gradient into parts of western/central ND early Monday morning. Overall coverage still remains uncertain, but there appears to be enough of a convective precipitation signal in short-term guidance to support inclusion of 5% probabilities for isolated instances of large hail occurring with elevated strong to severe storms given the strong shear that will be present. ...Southern/Central Arizona... An upper high will remain centered over the Four Corners region today. Orographic lift should be the main driver of isolated to widely scattered convection that should develop by early afternoon across the higher terrain of western NM and southern/central AZ. However, unlike the past couple of days, around 20 kt of easterly flow at 500 mb may prove sufficient to move these storms off the higher terrain and into lower elevations of southern/central AZ through the evening. A deeply mixed boundary layer is expected to be in place across this area, which will encourage strong/gusty downdraft winds potentially producing isolated damage. Marginally severe hail may also occur with more discrete initial development. These storms should move westward through the evening posing mainly a wind threat before eventually weakening as convective inhibition slowly increases. ...Florida... Strong low-level shear and outer rain bands associated with Hurricane Dorian are forecast to remain generally offshore and to the east of the southern/central FL Peninsula through the period. See the latest advisories from the National Hurricane Center for more information on other hazards associated with Hurricane Dorian. ..Gleason/Squitieri.. 09/01/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 01 2019 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OH VALLEY...NORTHERN/CENTRAL PLAINS...AND SOUTHERN/CENTRAL AZ... ...SUMMARY... Isolated severe storms may occur mainly this afternoon across parts of the Ohio Valley, this evening/tonight across portions of the northern/central Plains, and this afternoon/evening over parts of southern/central Arizona. ...Ohio Valley... Within broadly cyclonic flow over eastern Canada and the Great Lakes, a weak shortwave trough will move across parts of the OH Valley today. Modest ascent associated with this feature should encourage at least scattered storm development by the afternoon from eastern IN into northern KY and OH. This convection should then spread eastward across parts of WV into western PA through the early evening. Even though mid-level lapse rates will remain modest, diurnal heating will contribute to around 1000-2000 J/kg of MLCAPE across most of this region by this afternoon. A veering wind profile in low levels combined with around 20-30 kt of mid-level west-southwesterly flow may support occasional storm organization. Small multicells/clusters capable of producing isolated strong to damaging winds appear to be the main threat. This risk should quickly diminish with eastward extent into PA by late evening as instability wanes. ...Northern/Central Plains... Upper ridging will remain prominent across much of the northern/central Plains through the period. An upper trough/low over BC will move eastward into AB and gradually erode the upper ridge over the northern Rockies and vicinity late tonight. At the surface, a low will develop eastward across central/eastern MT from this evening through early Monday morning. An EML with steep mid-level lapse rates will gradually overspread much of the northern/central Plains though tonight. Greater low-level moisture will likely remain confined along/south of a surface boundary that will be located near the SD/NE border through this evening. Considerable uncertainty remains regarding possible convective initiation during the day, as subsidence associated with the upper ridge will probably tend to limit overall storm coverage across the northern/central Plains. A southerly low-level jet should strengthen to around 30-40 kt across western KS into central NE in the 00-06Z time frame. Warm air advection and related lift may support at least isolated storm development this evening across parts of western/central NE and vicinity. Although any storms that develop will probably be slightly elevated, steep mid-level lapse rates and rich low-level moisture will result in strong MUCAPE across this area, potentially in excess of 3000 J/kg. Around 35-45 kt of effective bulk shear will likely promote rotating updrafts with these storms, and isolated large hail may occur with any elevated supercells that form initially. Farther north, a strengthening south-southwesterly low-level jet late in the period (06-12Z) may encourage isolated convection to develop over northeastern MT/southern SK and subsequently spread southeastward along an instability gradient into parts of western/central ND early Monday morning. Overall coverage still remains uncertain, but there appears to be enough of a convective precipitation signal in short-term guidance to support inclusion of 5% probabilities for isolated instances of large hail occurring with elevated strong to severe storms given the strong shear that will be present. ...Southern/Central Arizona... An upper high will remain centered over the Four Corners region today. Orographic lift should be the main driver of isolated to widely scattered convection that should develop by early afternoon across the higher terrain of western NM and southern/central AZ. However, unlike the past couple of days, around 20 kt of easterly flow at 500 mb may prove sufficient to move these storms off the higher terrain and into lower elevations of southern/central AZ through the evening. A deeply mixed boundary layer is expected to be in place across this area, which will encourage strong/gusty downdraft winds potentially producing isolated damage. Marginally severe hail may also occur with more discrete initial development. These storms should move westward through the evening posing mainly a wind threat before eventually weakening as convective inhibition slowly increases. ...Florida... Strong low-level shear and outer rain bands associated with Hurricane Dorian are forecast to remain generally offshore and to the east of the southern/central FL Peninsula through the period. See the latest advisories from the National Hurricane Center for more information on other hazards associated with Hurricane Dorian. ..Gleason/Squitieri.. 09/01/2019 Read more