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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0755 AM CDT Sat Sep 07 2019 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS...AND NEAR THE NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail are possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...Synopsis... A progressive upper-air pattern will persist over the northern 1/3-1/2 of the CONUS, while continued weakening of longstanding southwestern ridging is expected. A leading shortwave trough -- now apparent in moisture-channel imagery over portions of central MT and western WY -- will shift east-southeastward over the northern High Plains to the Dakotas and northern NE through the period. Upstream ridging will shift northeastward from the Pacific Coast States to the northern/central Rockies. This will occur as a strong, negatively tilted trough -- initially located offshore from the Pacific Coast, moves inland in the 00-06Z time frame. By the end of the period, this trough at 500 mb should be located from western portions of WA/OR to near LAS then down the lower Colorado River Valley. At the surface, a quasistationary frontal zone was analyzed from a low over southeastern CO east-southeastward across northern parts of OK, to portions of the Mid-South and Tennessee Valley region. This boundary should move northward over the central Plains as a warm front, potentially merging with another baroclinic zone evident over southern SD. ...Central Plains across adjoining Missouri Valley... Isolated to widely scattered convection should form late this afternoon into this evening, within two now-conjoined corridors: from southeastern CO across northern KS to northwestern MO, and from western SD southeastward across central/southeastern NE. The northern limb will correspond to a narrow, triangular, northwest/ southeast-oriented plume of favorable moisture and antecedent destabilization, from western SD to central NE. Any sustained thunderstorms will have the potential to become supercellular, with large hail and strong-severe gusts possible. Any activity over CO, KS, NE and southern SD may be surface-based, with the northern rim of a boundary-layer moist axis impinging on relatively maximized low-level convergence near the frontal zone, low, and an inverted trough. Forecast soundings suggest 1500-2000 J/kg MLCAPE by mid/late afternoon over central NE and the eastern Sandhills, increasing to 2000-3000 J/kg toward northeastern KS (but amidst stronger capping). This will be supported by surface dew points in the 60s F and steep deep-layer lapse rates. Surface-based buoyancy will lessen in magnitude and spatial width with northward extent and in over SD and southwester extent into southeastern CO, but still may support a severe storm or two moving southeastward to eastward obliquely through the narrow favorable thermodynamic zone. Strong directional shear is expected near the warm frontal zone, though weak wind speeds will limit hodograph size in the lowest couple of km. Lack of greater coverage of both progged convection and favorable parameter space precludes more than a marginal unconditional severe risk at this time. However, the potential for convection to cross the gap between the two previous marginal risks resulted in their union. ...Interior Northwest... Widely scattered thunderstorms are expected to develop over and just east of the Cascade crest this afternoon and evening, offering isolated threats for severe hail/gusts as activity moves north- northeastward to northeastward over the outlook area. Strong heating of higher terrain will preferentially remove MLCINH conterminously with strengthening large-scale ascent related to the approaching Pacific trough. The resulting steepening of low/middle- level lapse rates, atop a corridor of at least marginally favorable low-level moisture remaining after diurnal mixing, will support pockets of 500-1000 J/kg peak preconvective MLCAPE. Just as importantly, a large-DCAPE, well-mixed boundary layer will develop over the eastern Cascades region and part of adjoining lower terrain, helping to maintain hail and accelerate downdrafts to the surface. Forecast soundings suggest 25-40 kt effective-shear vectors in support of predominantly multicellular (but potentially isolated supercellular) storm mode. ..Edwards/Smith.. 09/07/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0755 AM CDT Sat Sep 07 2019 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS...AND NEAR THE NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail are possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...Synopsis... A progressive upper-air pattern will persist over the northern 1/3-1/2 of the CONUS, while continued weakening of longstanding southwestern ridging is expected. A leading shortwave trough -- now apparent in moisture-channel imagery over portions of central MT and western WY -- will shift east-southeastward over the northern High Plains to the Dakotas and northern NE through the period. Upstream ridging will shift northeastward from the Pacific Coast States to the northern/central Rockies. This will occur as a strong, negatively tilted trough -- initially located offshore from the Pacific Coast, moves inland in the 00-06Z time frame. By the end of the period, this trough at 500 mb should be located from western portions of WA/OR to near LAS then down the lower Colorado River Valley. At the surface, a quasistationary frontal zone was analyzed from a low over southeastern CO east-southeastward across northern parts of OK, to portions of the Mid-South and Tennessee Valley region. This boundary should move northward over the central Plains as a warm front, potentially merging with another baroclinic zone evident over southern SD. ...Central Plains across adjoining Missouri Valley... Isolated to widely scattered convection should form late this afternoon into this evening, within two now-conjoined corridors: from southeastern CO across northern KS to northwestern MO, and from western SD southeastward across central/southeastern NE. The northern limb will correspond to a narrow, triangular, northwest/ southeast-oriented plume of favorable moisture and antecedent destabilization, from western SD to central NE. Any sustained thunderstorms will have the potential to become supercellular, with large hail and strong-severe gusts possible. Any activity over CO, KS, NE and southern SD may be surface-based, with the northern rim of a boundary-layer moist axis impinging on relatively maximized low-level convergence near the frontal zone, low, and an inverted trough. Forecast soundings suggest 1500-2000 J/kg MLCAPE by mid/late afternoon over central NE and the eastern Sandhills, increasing to 2000-3000 J/kg toward northeastern KS (but amidst stronger capping). This will be supported by surface dew points in the 60s F and steep deep-layer lapse rates. Surface-based buoyancy will lessen in magnitude and spatial width with northward extent and in over SD and southwester extent into southeastern CO, but still may support a severe storm or two moving southeastward to eastward obliquely through the narrow favorable thermodynamic zone. Strong directional shear is expected near the warm frontal zone, though weak wind speeds will limit hodograph size in the lowest couple of km. Lack of greater coverage of both progged convection and favorable parameter space precludes more than a marginal unconditional severe risk at this time. However, the potential for convection to cross the gap between the two previous marginal risks resulted in their union. ...Interior Northwest... Widely scattered thunderstorms are expected to develop over and just east of the Cascade crest this afternoon and evening, offering isolated threats for severe hail/gusts as activity moves north- northeastward to northeastward over the outlook area. Strong heating of higher terrain will preferentially remove MLCINH conterminously with strengthening large-scale ascent related to the approaching Pacific trough. The resulting steepening of low/middle- level lapse rates, atop a corridor of at least marginally favorable low-level moisture remaining after diurnal mixing, will support pockets of 500-1000 J/kg peak preconvective MLCAPE. Just as importantly, a large-DCAPE, well-mixed boundary layer will develop over the eastern Cascades region and part of adjoining lower terrain, helping to maintain hail and accelerate downdrafts to the surface. Forecast soundings suggest 25-40 kt effective-shear vectors in support of predominantly multicellular (but potentially isolated supercellular) storm mode. ..Edwards/Smith.. 09/07/2019 Read more

000
ABPZ20 KNHC 071131
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sat Sep 7 2019

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

The National Hurricane Center is issuing advisories on Tropical
Storm Juliette, located about 1100 miles west of the southern
tip of the Baja California peninsula.

An area of low pressure is expected to form early next week a few
hundred miles southwest of the southern coast of Mexico. Gradual
development of this system is possible thereafter while it moves
west-northwestward at around 10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...30 percent.

$$
Forecaster Berg

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Sat Sep 07 2019 Valid 101200Z - 151200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... The medium-range models including the ECMWF, GFS, UKMET and Canadian are in generally good agreement at the start of the day 4 to 8 period. The models move a shortwave ridge across the northern Plains on Tuesday as an upper-level trough develops in the western U.S. At the surface, the models have a corridor of maximized low-level moisture from the central High Plains east-northeastward into the Upper Mississippi Valley. Moderate instability will be possible along parts of this corridor Tuesday afternoon. Thunderstorms that can develop along the instability gradient may have a severe threat mainly during the late afternoon and early evening. However, uncertainty remains too considerable to add a threat area. On Wednesday and Thursday, the model solutions agree that an upper-level trough along with an associated mid-level jet will move across the north-central U.S. Thunderstorms will be possible ahead of the trough on Wednesday across a moist and unstable airmass in the northern Plains and Upper Mississippi Valley. Thunderstorms will again be possible ahead of the upper-level trough on Thursday from the Upper Mississippi Valley into the Great Lakes. Some potential exists for a severe threat each day from Wednesday to Thursday. However, there is disagreement concerning how much deep-layer shear will be available across the warm sector. For this reason, will not add a threat area at this time. ...Friday/Day 7 to Saturday/Day 8... On Friday and Saturday, the models move the upper-level trough across the Great Lakes although the solutions have different timing. The GFS, ECMWF and Canadian solutions are in general agreement further west, returning low-level moisture into the north-central states from Friday night into Saturday. If this scenario pans out, an isolated severe threat would be possible in parts of the Dakotas, Nebraska and Iowa where these solutions suggest moderate instability could develop. Uncertainty is substantial at this range and will not outlook a threat area from Friday into Saturday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Sat Sep 07 2019 Valid 101200Z - 151200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... The medium-range models including the ECMWF, GFS, UKMET and Canadian are in generally good agreement at the start of the day 4 to 8 period. The models move a shortwave ridge across the northern Plains on Tuesday as an upper-level trough develops in the western U.S. At the surface, the models have a corridor of maximized low-level moisture from the central High Plains east-northeastward into the Upper Mississippi Valley. Moderate instability will be possible along parts of this corridor Tuesday afternoon. Thunderstorms that can develop along the instability gradient may have a severe threat mainly during the late afternoon and early evening. However, uncertainty remains too considerable to add a threat area. On Wednesday and Thursday, the model solutions agree that an upper-level trough along with an associated mid-level jet will move across the north-central U.S. Thunderstorms will be possible ahead of the trough on Wednesday across a moist and unstable airmass in the northern Plains and Upper Mississippi Valley. Thunderstorms will again be possible ahead of the upper-level trough on Thursday from the Upper Mississippi Valley into the Great Lakes. Some potential exists for a severe threat each day from Wednesday to Thursday. However, there is disagreement concerning how much deep-layer shear will be available across the warm sector. For this reason, will not add a threat area at this time. ...Friday/Day 7 to Saturday/Day 8... On Friday and Saturday, the models move the upper-level trough across the Great Lakes although the solutions have different timing. The GFS, ECMWF and Canadian solutions are in general agreement further west, returning low-level moisture into the north-central states from Friday night into Saturday. If this scenario pans out, an isolated severe threat would be possible in parts of the Dakotas, Nebraska and Iowa where these solutions suggest moderate instability could develop. Uncertainty is substantial at this range and will not outlook a threat area from Friday into Saturday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Sat Sep 07 2019 Valid 101200Z - 151200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... The medium-range models including the ECMWF, GFS, UKMET and Canadian are in generally good agreement at the start of the day 4 to 8 period. The models move a shortwave ridge across the northern Plains on Tuesday as an upper-level trough develops in the western U.S. At the surface, the models have a corridor of maximized low-level moisture from the central High Plains east-northeastward into the Upper Mississippi Valley. Moderate instability will be possible along parts of this corridor Tuesday afternoon. Thunderstorms that can develop along the instability gradient may have a severe threat mainly during the late afternoon and early evening. However, uncertainty remains too considerable to add a threat area. On Wednesday and Thursday, the model solutions agree that an upper-level trough along with an associated mid-level jet will move across the north-central U.S. Thunderstorms will be possible ahead of the trough on Wednesday across a moist and unstable airmass in the northern Plains and Upper Mississippi Valley. Thunderstorms will again be possible ahead of the upper-level trough on Thursday from the Upper Mississippi Valley into the Great Lakes. Some potential exists for a severe threat each day from Wednesday to Thursday. However, there is disagreement concerning how much deep-layer shear will be available across the warm sector. For this reason, will not add a threat area at this time. ...Friday/Day 7 to Saturday/Day 8... On Friday and Saturday, the models move the upper-level trough across the Great Lakes although the solutions have different timing. The GFS, ECMWF and Canadian solutions are in general agreement further west, returning low-level moisture into the north-central states from Friday night into Saturday. If this scenario pans out, an isolated severe threat would be possible in parts of the Dakotas, Nebraska and Iowa where these solutions suggest moderate instability could develop. Uncertainty is substantial at this range and will not outlook a threat area from Friday into Saturday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Sat Sep 07 2019 Valid 101200Z - 151200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... The medium-range models including the ECMWF, GFS, UKMET and Canadian are in generally good agreement at the start of the day 4 to 8 period. The models move a shortwave ridge across the northern Plains on Tuesday as an upper-level trough develops in the western U.S. At the surface, the models have a corridor of maximized low-level moisture from the central High Plains east-northeastward into the Upper Mississippi Valley. Moderate instability will be possible along parts of this corridor Tuesday afternoon. Thunderstorms that can develop along the instability gradient may have a severe threat mainly during the late afternoon and early evening. However, uncertainty remains too considerable to add a threat area. On Wednesday and Thursday, the model solutions agree that an upper-level trough along with an associated mid-level jet will move across the north-central U.S. Thunderstorms will be possible ahead of the trough on Wednesday across a moist and unstable airmass in the northern Plains and Upper Mississippi Valley. Thunderstorms will again be possible ahead of the upper-level trough on Thursday from the Upper Mississippi Valley into the Great Lakes. Some potential exists for a severe threat each day from Wednesday to Thursday. However, there is disagreement concerning how much deep-layer shear will be available across the warm sector. For this reason, will not add a threat area at this time. ...Friday/Day 7 to Saturday/Day 8... On Friday and Saturday, the models move the upper-level trough across the Great Lakes although the solutions have different timing. The GFS, ECMWF and Canadian solutions are in general agreement further west, returning low-level moisture into the north-central states from Friday night into Saturday. If this scenario pans out, an isolated severe threat would be possible in parts of the Dakotas, Nebraska and Iowa where these solutions suggest moderate instability could develop. Uncertainty is substantial at this range and will not outlook a threat area from Friday into Saturday. Read more

Issued at 1100 PM HST Fri Sep 06 2019 000 WTPZ41 KNHC 070834 TCDEP1 Tropical Storm Juliette Discussion Number 25 NWS National Hurricane Center Miami FL EP112019 1100 PM HST Fri Sep 06 2019 Juliette is rapidly declining and is well on its way to becoming post-tropical. Cloud tops have warmed dramatically over the past few hours, and satellite intensity estimates have decreased sharply in turn. ASCAT data that arrived shortly before 06Z revealed that Juliette is not as strong as previously estimated, with max winds of only 35-40 kt. Based on that new info, the intensity has been adjusted down to 40 kt. The main change in the NHC forecast is that it now shows Juliette becoming post-tropical in 24 hours. Given current trends, it could certainly happen much sooner than that. Otherwise, the overall reasoning behind the forecast is the same. Juliette is located over quite cold waters and will steadily spin down over the next several days. The tropical storm has turned westward and should continue heading west through the middle of next week, steered by low-level easterly trade winds. This track will take the soon-to-be remnant low over warmer waters by day 5, and some of the dynamical guidance suggests that Juliette could try to make a comeback at that time. However, extremely high wind shear should prevent any convection that does develop from becoming organized and regeneration is not expected. The NHC track and intensity forecasts remain very close to the various consensus aids throughout the 5-day period. FORECAST POSITIONS AND MAX WINDS INIT 07/0900Z 23.8N 127.1W 40 KT 45 MPH 12H 07/1800Z 24.0N 128.8W 35 KT 40 MPH 24H 08/0600Z 24.0N 131.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 08/1800Z 24.0N 133.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 09/0600Z 23.9N 135.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 10/0600Z 23.7N 139.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 11/0600Z 23.5N 142.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 12/0600Z 24.0N 145.0W 25 KT 30 MPH...DISSIPATED $$ Forecaster Zelinsky

Issued at 0900 UTC SAT SEP 07 2019 000 FOPZ11 KNHC 070834 PWSEP1 TROPICAL STORM JULIETTE WIND SPEED PROBABILITIES NUMBER 25 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112019 0900 UTC SAT SEP 07 2019 AT 0900Z THE CENTER OF TROPICAL STORM JULIETTE WAS LOCATED NEAR LATITUDE 23.8 NORTH...LONGITUDE 127.1 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 SAT 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 SAT 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED PERIODS TO TO TO TO TO TO TO 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED 06Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 25N 130W 34 5 11(16) X(16) X(16) X(16) X(16) X(16) 25N 135W 34 X X( X) 5( 5) 13(18) 1(19) X(19) X(19) 25N 135W 50 X X( X) X( X) 2( 2) 1( 3) X( 3) X( 3) 25N 140W 34 X X( X) X( X) 1( 1) 6( 7) 3(10) 1(11) 25N 145W 34 X X( X) X( X) X( X) X( X) 2( 2) 4( 6) $$ FORECASTER ZELINSKY

Issued at 1100 PM HST Fri Sep 06 2019 000 WTPZ31 KNHC 070833 TCPEP1 BULLETIN Tropical Storm Juliette Advisory Number 25 NWS National Hurricane Center Miami FL EP112019 1100 PM HST Fri Sep 06 2019 ...JULIETTE FORECAST TO BECOME POST-TROPICAL ON SATURDAY... SUMMARY OF 1100 PM HST...0900 UTC...INFORMATION ----------------------------------------------- LOCATION...23.8N 127.1W ABOUT 1090 MI...1755 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...W OR 280 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 1100 PM HST (0900 UTC), the center of Tropical Storm Juliette was located near latitude 23.8 North, longitude 127.1 West. Juliette is moving toward the west near 12 mph (19 km/h). This general motion should continue into the middle of next week. Maximum sustained winds have decreased to near 45 mph (75 km/h) with higher gusts. Additional weakening is forecast, and Juliette is expected to become a post-tropical remnant low on Saturday. Tropical-storm-force winds extend outward up to 70 miles (110 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 500 AM HST. $$ Forecaster Zelinsky

...JULIETTE FORECAST TO BECOME POST-TROPICAL ON SATURDAY... As of 11:00 PM HST Fri Sep 6 the center of Juliette was located near 23.8, -127.1 with movement W at 12 mph. The minimum central pressure was 1005 mb with maximum sustained winds of about 45 mph.

Issued at 0900 UTC SAT SEP 07 2019 000 WTPZ21 KNHC 070833 TCMEP1 TROPICAL STORM JULIETTE FORECAST/ADVISORY NUMBER 25 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112019 0900 UTC SAT SEP 07 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. TROPICAL STORM CENTER LOCATED NEAR 23.8N 127.1W AT 07/0900Z POSITION ACCURATE WITHIN 35 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT. 34 KT....... 60NE 30SE 0SW 60NW. 12 FT SEAS..120NE 60SE 90SW 120NW. 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 23.8N 127.1W AT 07/0900Z AT 07/0600Z CENTER WAS LOCATED NEAR 23.8N 126.6W FORECAST VALID 07/1800Z 24.0N 128.8W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 40NE 0SE 0SW 40NW. FORECAST VALID 08/0600Z 24.0N 131.1W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 08/1800Z 24.0N 133.5W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 09/0600Z 23.9N 135.7W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 10/0600Z 23.7N 139.6W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. 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 11/0600Z 23.5N 142.5W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. OUTLOOK VALID 12/0600Z 24.0N 145.0W...DISSIPATED MAX WIND 25 KT...GUSTS 35 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 23.8N 127.1W NEXT ADVISORY AT 07/1500Z $$ FORECASTER ZELINSKY

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sat Sep 07 2019 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS EASTWARD INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms associated with hail and marginally severe wind gusts will be possible on Monday across parts of the central and northern Plains eastward into the upper Mississippi Valley. ...Central and Northern Plains/Upper Mississippi Valley... An upper-level ridge is forecast to move into the Great Lakes on Monday as a shortwave trough moves northeastward into the northern Plains. At the surface, a low is forecast to deepen in the northern Plains as a warm front advances northward across the upper Mississippi Valley. To the south of the warm front, a corridor of maximized low-level moisture is forecast to exist from western Illinois northwestward into southeastern South Dakota by Monday afternoon. Pockets of moderate instability may develop along this corridor. Model forecasts suggest that elevated convection will form north of the warm front from the eastern Dakotas into Minnesota Monday afternoon. Surface-based convective development will be possible mainly from the warm front southward across the moist sector during the late afternoon and early evening. The environment across the moist sector may support an isolated severe threat with forecast soundings showing MLCAPE values in the 1500 to 2500 J/kg range and 0-6 km shear of 30 to 40 kt. Mesoscale conditions will likely determine which areas have the greatest convective threat. For this reason, uncertainty is substantial concerning where the severe threat will become maximized. Have drawn a marginal threat area in eastern South Dakota, eastern Nebraska and Iowa where severe parameters show the greatest potential at this time. ..Broyles.. 09/07/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sat Sep 07 2019 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS EASTWARD INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms associated with hail and marginally severe wind gusts will be possible on Monday across parts of the central and northern Plains eastward into the upper Mississippi Valley. ...Central and Northern Plains/Upper Mississippi Valley... An upper-level ridge is forecast to move into the Great Lakes on Monday as a shortwave trough moves northeastward into the northern Plains. At the surface, a low is forecast to deepen in the northern Plains as a warm front advances northward across the upper Mississippi Valley. To the south of the warm front, a corridor of maximized low-level moisture is forecast to exist from western Illinois northwestward into southeastern South Dakota by Monday afternoon. Pockets of moderate instability may develop along this corridor. Model forecasts suggest that elevated convection will form north of the warm front from the eastern Dakotas into Minnesota Monday afternoon. Surface-based convective development will be possible mainly from the warm front southward across the moist sector during the late afternoon and early evening. The environment across the moist sector may support an isolated severe threat with forecast soundings showing MLCAPE values in the 1500 to 2500 J/kg range and 0-6 km shear of 30 to 40 kt. Mesoscale conditions will likely determine which areas have the greatest convective threat. For this reason, uncertainty is substantial concerning where the severe threat will become maximized. Have drawn a marginal threat area in eastern South Dakota, eastern Nebraska and Iowa where severe parameters show the greatest potential at this time. ..Broyles.. 09/07/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sat Sep 07 2019 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS EASTWARD INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms associated with hail and marginally severe wind gusts will be possible on Monday across parts of the central and northern Plains eastward into the upper Mississippi Valley. ...Central and Northern Plains/Upper Mississippi Valley... An upper-level ridge is forecast to move into the Great Lakes on Monday as a shortwave trough moves northeastward into the northern Plains. At the surface, a low is forecast to deepen in the northern Plains as a warm front advances northward across the upper Mississippi Valley. To the south of the warm front, a corridor of maximized low-level moisture is forecast to exist from western Illinois northwestward into southeastern South Dakota by Monday afternoon. Pockets of moderate instability may develop along this corridor. Model forecasts suggest that elevated convection will form north of the warm front from the eastern Dakotas into Minnesota Monday afternoon. Surface-based convective development will be possible mainly from the warm front southward across the moist sector during the late afternoon and early evening. The environment across the moist sector may support an isolated severe threat with forecast soundings showing MLCAPE values in the 1500 to 2500 J/kg range and 0-6 km shear of 30 to 40 kt. Mesoscale conditions will likely determine which areas have the greatest convective threat. For this reason, uncertainty is substantial concerning where the severe threat will become maximized. Have drawn a marginal threat area in eastern South Dakota, eastern Nebraska and Iowa where severe parameters show the greatest potential at this time. ..Broyles.. 09/07/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Sat Sep 07 2019 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS EASTWARD INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms associated with hail and marginally severe wind gusts will be possible on Monday across parts of the central and northern Plains eastward into the upper Mississippi Valley. ...Central and Northern Plains/Upper Mississippi Valley... An upper-level ridge is forecast to move into the Great Lakes on Monday as a shortwave trough moves northeastward into the northern Plains. At the surface, a low is forecast to deepen in the northern Plains as a warm front advances northward across the upper Mississippi Valley. To the south of the warm front, a corridor of maximized low-level moisture is forecast to exist from western Illinois northwestward into southeastern South Dakota by Monday afternoon. Pockets of moderate instability may develop along this corridor. Model forecasts suggest that elevated convection will form north of the warm front from the eastern Dakotas into Minnesota Monday afternoon. Surface-based convective development will be possible mainly from the warm front southward across the moist sector during the late afternoon and early evening. The environment across the moist sector may support an isolated severe threat with forecast soundings showing MLCAPE values in the 1500 to 2500 J/kg range and 0-6 km shear of 30 to 40 kt. Mesoscale conditions will likely determine which areas have the greatest convective threat. For this reason, uncertainty is substantial concerning where the severe threat will become maximized. Have drawn a marginal threat area in eastern South Dakota, eastern Nebraska and Iowa where severe parameters show the greatest potential at this time. ..Broyles.. 09/07/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ..Elliott.. 09/07/2019 ...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 1255 AM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ..Elliott.. 09/07/2019 ...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 1255 AM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ..Elliott.. 09/07/2019 ...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 1255 AM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ..Elliott.. 09/07/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more