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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 AM CDT Sat Sep 14 2019 Valid 141300Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MS VALLEY...AND THIS AFTERNOON/EVENING ACROSS PARTS OF AZ... ...SUMMARY... Isolated severe storms with damaging gusts and large hail will be possible from the upper Mississippi Valley into the central Plains. Isolated damaging gusts will be possible this afternoon/evening in the lower desert regions of Arizona. ...Upper MS Valley to the central Plains through tonight... Elevated thunderstorms are ongoing over northeast NE in a zone of low-level warm advection on the nose of a 45 kt southwesterly low-level jet. This zone of ascent and storms will spread east-northeastward across northern IA/southern MN through the day, immediately in advance of a low-amplitude shortwave trough moving from the Dakotas to the upper MS Valley. In the wake of the warm advection, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining convective inhibition through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development is uncertain this afternoon/evening. The elevated convection could pose a threat for isolated large hail as far east as western WI later today into tonight. If surface-based storms form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Somewhat weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated damaging gusts and large hail. ...Southern AZ this afternoon/evening... An MCV over northwest Mexico will drift north-northwestward toward southeast AZ through tonight. A substantial increase in low-midlevel moisture/PW has occurred across southeast and south central AZ the past 12-24 hours, and the moisture will continue to spread westward today. Stronger surface heating west of the thicker clouds, as well as 10-20 kt east-northeasterly midlevel flow around the north side of the MCV, will provide an environment favorable for storms to form and spread westward into the lower deserts this afternoon/evening. Typical inverted-v profiles and MLCAPE of 500-1000 J/kg will support a threat for hybrid microbursts capable of producing isolated damaging winds. ...Central/southern Appalachians this afternoon... A narrow corridor of weak-moderate buoyancy is expected this afternoon across the central/southern Appalachians, and a few storms are expected along a cold front and over the higher terrain this afternoon. Very isolated strong downburst winds cannot be ruled out, though the threat is too marginal to warrant damaging wind probabilities. ..Thompson/Gleason.. 09/14/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 AM CDT Sat Sep 14 2019 Valid 141300Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MS VALLEY...AND THIS AFTERNOON/EVENING ACROSS PARTS OF AZ... ...SUMMARY... Isolated severe storms with damaging gusts and large hail will be possible from the upper Mississippi Valley into the central Plains. Isolated damaging gusts will be possible this afternoon/evening in the lower desert regions of Arizona. ...Upper MS Valley to the central Plains through tonight... Elevated thunderstorms are ongoing over northeast NE in a zone of low-level warm advection on the nose of a 45 kt southwesterly low-level jet. This zone of ascent and storms will spread east-northeastward across northern IA/southern MN through the day, immediately in advance of a low-amplitude shortwave trough moving from the Dakotas to the upper MS Valley. In the wake of the warm advection, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining convective inhibition through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development is uncertain this afternoon/evening. The elevated convection could pose a threat for isolated large hail as far east as western WI later today into tonight. If surface-based storms form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Somewhat weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated damaging gusts and large hail. ...Southern AZ this afternoon/evening... An MCV over northwest Mexico will drift north-northwestward toward southeast AZ through tonight. A substantial increase in low-midlevel moisture/PW has occurred across southeast and south central AZ the past 12-24 hours, and the moisture will continue to spread westward today. Stronger surface heating west of the thicker clouds, as well as 10-20 kt east-northeasterly midlevel flow around the north side of the MCV, will provide an environment favorable for storms to form and spread westward into the lower deserts this afternoon/evening. Typical inverted-v profiles and MLCAPE of 500-1000 J/kg will support a threat for hybrid microbursts capable of producing isolated damaging winds. ...Central/southern Appalachians this afternoon... A narrow corridor of weak-moderate buoyancy is expected this afternoon across the central/southern Appalachians, and a few storms are expected along a cold front and over the higher terrain this afternoon. Very isolated strong downburst winds cannot be ruled out, though the threat is too marginal to warrant damaging wind probabilities. ..Thompson/Gleason.. 09/14/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 AM CDT Sat Sep 14 2019 Valid 141300Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MS VALLEY...AND THIS AFTERNOON/EVENING ACROSS PARTS OF AZ... ...SUMMARY... Isolated severe storms with damaging gusts and large hail will be possible from the upper Mississippi Valley into the central Plains. Isolated damaging gusts will be possible this afternoon/evening in the lower desert regions of Arizona. ...Upper MS Valley to the central Plains through tonight... Elevated thunderstorms are ongoing over northeast NE in a zone of low-level warm advection on the nose of a 45 kt southwesterly low-level jet. This zone of ascent and storms will spread east-northeastward across northern IA/southern MN through the day, immediately in advance of a low-amplitude shortwave trough moving from the Dakotas to the upper MS Valley. In the wake of the warm advection, storm initiation will depend on weak low-level ascent along a surface trough that extends southwestward across NE/KS. Stronger surface heating and deeper mixing is expected along the trough in KS, with lesser mixing depths and a greater probability of maintaining convective inhibition through the afternoon in the warm sector farther northeast. Thus, surface-based thunderstorm development is uncertain this afternoon/evening. The elevated convection could pose a threat for isolated large hail as far east as western WI later today into tonight. If surface-based storms form as far northeast as southern MN this afternoon, vertical shear profiles will be sufficient for supercells. Somewhat weaker vertical shear is expected with southwestward extent into southwest KS, where high-based storms would pose a threat for isolated damaging gusts and large hail. ...Southern AZ this afternoon/evening... An MCV over northwest Mexico will drift north-northwestward toward southeast AZ through tonight. A substantial increase in low-midlevel moisture/PW has occurred across southeast and south central AZ the past 12-24 hours, and the moisture will continue to spread westward today. Stronger surface heating west of the thicker clouds, as well as 10-20 kt east-northeasterly midlevel flow around the north side of the MCV, will provide an environment favorable for storms to form and spread westward into the lower deserts this afternoon/evening. Typical inverted-v profiles and MLCAPE of 500-1000 J/kg will support a threat for hybrid microbursts capable of producing isolated damaging winds. ...Central/southern Appalachians this afternoon... A narrow corridor of weak-moderate buoyancy is expected this afternoon across the central/southern Appalachians, and a few storms are expected along a cold front and over the higher terrain this afternoon. Very isolated strong downburst winds cannot be ruled out, though the threat is too marginal to warrant damaging wind probabilities. ..Thompson/Gleason.. 09/14/2019 Read more

The Neck fire started by lightning on September 5, 2019 in the Neck of the Desert area of the Color Country District BLM district, approximately 25 miles NNW of Cedar City. The fire is burning in heavy grass and brush and some pinyon and juniper. Dry conditions and high winds coupled with thunderstorm activity caused the fire to burn over 10,000 acres in the first 48 hours. Great Basin Type II team 7 took over management of the fire at 0600 on September 8, 2019. The fire consumed 19,151 acres and is 100% contained at this point. A local Type-4 team has assumed command of the remaining repair suppression work. For more information call the Color Country BLM office at (435)

000
ABPZ20 KNHC 141148
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sat Sep 14 2019

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

The National Hurricane Center is issuing advisories on Tropical
Storm Kiko, located several hundred miles southwest of the southern
tip of the Baja California peninsula.

A weak area of low pressure centered about 500 miles south-southwest
of Acapulco, Mexico, is producing disorganized showers and a few
thunderstorms. Some gradual development of this system is possible,
and a tropical depression could form by the middle of next week
while it moves slowly westward or west-northwestward well offshore
the southwestern coast of Mexico.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...50 percent.

Another broad area of low pressure is located a few hundred miles
south of the coast of Guatemala. This system is producing a more
concentrated but also disorganized area of showers and
thunderstorms. Environmental conditions are forecast to be conducive
for development, and a tropical depression could form by the middle
of next week while the system moves west-northwestward, near or
parallel to the coast of Mexico.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...50 percent.

$$
Forecaster Brown

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0352 AM CDT Sat Sep 14 2019 Valid 171200Z - 221200Z ...DISCUSSION... The medium-range models generally suggest that subtropical ridging may remain a prominent influence across much of the south central and southeastern U.S. from the middle of the coming work week into next weekend. However, rather large spread is evident concerning short wave developments within the westerlies, indicative of poor pattern predictability throughout the period. Even early in the period (Tue/Wed), there are substantial differences concerning a compact, but vigorous short wave impulse emerging from the Great Basin, which could potentially contribute to at least some risk for severe storms, from the immediate lee of the northern Rockies through the northern Plains and portions of the Upper Midwest. And uncertainties associated with these differences are compounded by the uncertain influence of a preceding wave, emanating from the lower latitudes, on low-level moisture and instability across this region. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0352 AM CDT Sat Sep 14 2019 Valid 171200Z - 221200Z ...DISCUSSION... The medium-range models generally suggest that subtropical ridging may remain a prominent influence across much of the south central and southeastern U.S. from the middle of the coming work week into next weekend. However, rather large spread is evident concerning short wave developments within the westerlies, indicative of poor pattern predictability throughout the period. Even early in the period (Tue/Wed), there are substantial differences concerning a compact, but vigorous short wave impulse emerging from the Great Basin, which could potentially contribute to at least some risk for severe storms, from the immediate lee of the northern Rockies through the northern Plains and portions of the Upper Midwest. And uncertainties associated with these differences are compounded by the uncertain influence of a preceding wave, emanating from the lower latitudes, on low-level moisture and instability across this region. Read more

5-Day Uncertainty Track last updated Sat, 14 Sep 2019 08:41:43 GMT


Wind Speed Probabilities last updated Sat, 14 Sep 2019 09:31:24 GMT

Issued at 200 AM PDT Sat Sep 14 2019 434 WTPZ43 KNHC 140839 TCDEP3 Tropical Storm Kiko Discussion Number 8 NWS National Hurricane Center Miami FL EP132019 200 AM PDT Sat Sep 14 2019 A 0205 UTC WindSat pass showed that Kiko's low-level structure has become significantly better defined. The storm has also been producing a persistent cluster of deep convection, although microwave fixes suggest that the surface center is located beneath the eastern side of the convective mass. Satellite intensity estimates range from 45-55 kt, but scatterometer data from a few hours ago indicated that maximum winds were between 40-45 kt. Kiko's initial intensity is therefore held at 45 kt, but the cyclone's improved structure likely means that its winds will increase again soon. There's still a swath of dry air to the north and west of the storm, but now that the inner core has become more established, Kiko should be able to take advantage of low shear and sufficiently warm waters to strengthen during the next couple of days. The NHC intensity forecast is very close to the HFIP Corrected Consensus (HCCA) and Florida State Superensemble (FSSE) during the first 36 hours, showing a little more strengthening than the previous forecast, and making Kiko a hurricane in 24 hours. While the new forecast is also a little higher at 48 hours, it's still below the HCCA, FSSE, and HWRF solutions, so additional adjustment could be required in subsequent advisories. Weakening should commence by day 3 due to little to no oceanic heat content and gradually increasing westerly shear. Kiko is moving west-northwestward, or 285/8 kt. Mid-level ridging to the north should drive the cyclone on a westward to west-northwestward heading for the entire forecast period. The most significant gain in latitude should occur from Sunday through Tuesday when Kiko is at its strongest and responds to a break in the ridge between 120W and 130W. While the GFS and ECMWF models still prefer northern and southern solutions within the guidance envelope, respectively, the distance between the two at day 5 has been cut in half in the latest model runs, suggesting that the track uncertainty is not as high as it was previously. The NHC track forecast remains close to the various multi-model consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 17.3N 117.1W 45 KT 50 MPH 12H 14/1800Z 17.4N 118.3W 55 KT 65 MPH 24H 15/0600Z 17.7N 119.7W 65 KT 75 MPH 36H 15/1800Z 18.1N 121.0W 70 KT 80 MPH 48H 16/0600Z 18.6N 122.3W 70 KT 80 MPH 72H 17/0600Z 19.5N 124.7W 55 KT 65 MPH 96H 18/0600Z 20.2N 126.9W 40 KT 45 MPH 120H 19/0600Z 20.6N 129.6W 30 KT 35 MPH $$ Forecaster Berg

Issued at 0900 UTC SAT SEP 14 2019 416 FOPZ13 KNHC 140839 PWSEP3 TROPICAL STORM KIKO WIND SPEED PROBABILITIES NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132019 0900 UTC SAT SEP 14 2019 AT 0900Z THE CENTER OF TROPICAL STORM KIKO WAS LOCATED NEAR LATITUDE 17.3 NORTH...LONGITUDE 117.1 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 45 KTS...50 MPH...85 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 ISLA CLARION 34 2 3( 5) X( 5) X( 5) X( 5) X( 5) X( 5) 15N 115W 34 1 1( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) 20N 115W 34 1 2( 3) 1( 4) X( 4) X( 4) X( 4) X( 4) 15N 120W 34 2 5( 7) 5(12) 2(14) 1(15) X(15) X(15) 20N 120W 34 3 15(18) 16(34) 5(39) 3(42) X(42) X(42) 20N 120W 50 X 1( 1) 2( 3) 1( 4) X( 4) X( 4) X( 4) 15N 125W 34 X X( X) 2( 2) 2( 4) 5( 9) 1(10) X(10) 20N 125W 34 X X( X) 4( 4) 8(12) 40(52) 7(59) 1(60) 20N 125W 50 X X( X) X( X) 1( 1) 16(17) 5(22) X(22) 20N 125W 64 X X( X) X( X) X( X) 5( 5) 2( 7) X( 7) 25N 125W 34 X X( X) X( X) X( X) 1( 1) 2( 3) X( 3) 20N 130W 34 X X( X) X( X) X( X) 1( 1) 5( 6) 5(11) $$ FORECASTER BERG

Issued at 0900 UTC SAT SEP 14 2019 000 WTPZ23 KNHC 140839 TCMEP3 TROPICAL STORM KIKO FORECAST/ADVISORY NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132019 0900 UTC SAT SEP 14 2019 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. TROPICAL STORM CENTER LOCATED NEAR 17.3N 117.1W AT 14/0900Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1001 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT....... 60NE 0SE 40SW 60NW. 12 FT SEAS.. 30NE 0SE 45SW 90NW. 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 17.3N 117.1W AT 14/0900Z AT 14/0600Z CENTER WAS LOCATED NEAR 17.3N 116.7W FORECAST VALID 14/1800Z 17.4N 118.3W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 30NE 0SE 0SW 30NW. 34 KT... 60NE 30SE 50SW 60NW. FORECAST VALID 15/0600Z 17.7N 119.7W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 15NE 0SE 0SW 0NW. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 60NE 40SE 50SW 60NW. FORECAST VALID 15/1800Z 18.1N 121.0W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 15NE 0SE 0SW 15NW. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 60NE 50SE 50SW 60NW. FORECAST VALID 16/0600Z 18.6N 122.3W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 15NE 0SE 0SW 15NW. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 60NE 50SE 50SW 60NW. FORECAST VALID 17/0600Z 19.5N 124.7W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 30NE 20SE 0SW 20NW. 34 KT... 50NE 40SE 30SW 50NW. 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 18/0600Z 20.2N 126.9W MAX WIND 40 KT...GUSTS 50 KT. OUTLOOK VALID 19/0600Z 20.6N 129.6W MAX WIND 30 KT...GUSTS 40 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.3N 117.1W NEXT ADVISORY AT 14/1500Z $$ FORECASTER BERG

Issued at 200 AM PDT Sat Sep 14 2019 000 WTPZ33 KNHC 140839 TCPEP3 BULLETIN Tropical Storm Kiko Advisory Number 8 NWS National Hurricane Center Miami FL EP132019 200 AM PDT Sat Sep 14 2019 ...KIKO FORECAST TO BECOME A HURRICANE BY TONIGHT... SUMMARY OF 200 AM PDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...17.3N 117.1W ABOUT 605 MI...975 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 200 AM PDT (0900 UTC), the center of Tropical Storm Kiko was located near latitude 17.3 North, longitude 117.1 West. Kiko is moving toward the west-northwest near 9 mph (15 km/h). A westward or west-northwestward course at a slightly slower forward speed is expected during the next several days. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Strengthening is forecast during the next couple of days. Kiko is expected to become a hurricane by tonight and maintain hurricane intensity into Monday. Tropical-storm-force winds extend outward up to 70 miles (110 km) from the center. The estimated minimum central pressure is 1001 mb (29.56 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 800 AM PDT. $$ Forecaster Berg

...KIKO FORECAST TO BECOME A HURRICANE BY TONIGHT... As of 2:00 AM PDT Sat Sep 14 the center of Kiko was located near 17.3, -117.1 with movement WNW at 9 mph. The minimum central pressure was 1001 mb with maximum sustained winds of about 50 mph.

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sat Sep 14 2019 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE MONDAY NIGHT ACROSS WESTERN UTAH AND ADJACENT PORTIONS OF THE GREAT BASIN... ...SUMMARY... Strong thunderstorms may impact western Utah and adjacent portions of the Great Basin late Monday night, perhaps accompanied by at least some risk for potentially damaging wind gusts. ...Discussion... Within the westerlies, models indicate substantive further amplification of mid-level ridging along an axis from the Upper Midwest into Hudson Bay during this period. As this occurs, downstream troughing is forecast to dig east-southeast of the Canadian Maritimes and north Atlantic coast, with an associated surface cold front advancing as far south as the Mid Atlantic Coast states and Ohio Valley by 12Z Tuesday. Within much weaker troughing off the south Atlantic coast, to the south of this feature, Humberto may intensify to hurricane strength, but is expected to be in the process of accelerating eastward away from the coast, through the western Atlantic. Meanwhile, as another significant short wave impulse digs southeast of the Gulf of Alaska, to the west of the British Columbia coast, initially amplified upper troughing near the Pacific coast is expected to increasingly split. One emerging short wave trough is forecast to accelerate across and northeast of the Canadian Rockies, while a more significant impulse to the south pivots inland of the Oregon and California coast, toward the northern Rockies. Strong forcing for ascent and wind fields/vertical shear associated with the trailing impulse may contribute to the best potential for any appreciable severe weather risk during this period. However, it appears that this probably will be tempered by drying over the Great Basin in the wake of a preceding short wave impulse, emerging from the lower latitudes ahead of the inland advancing troughing. Of most concern at the present time, at least some model output suggests that a return flow of monsoonal moisture could develop in a narrow plume, ahead the vigorous short wave and associated cold front, across western Utah by late Monday night. This could contribute to sufficient destabilization for the initiation of storms prior to 17/09-12Z, west of the Wasatch into the Great Salt Lake vicinity, where southwesterly flow in the 700-500 mb layer may strengthen to 40-70 kt. With relatively dry sub-cloud air contributing to evaporative cooling in downdrafts, downward mixing of higher momentum air may result in strong surface gusts. ..Kerr.. 09/14/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sat Sep 14 2019 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE MONDAY NIGHT ACROSS WESTERN UTAH AND ADJACENT PORTIONS OF THE GREAT BASIN... ...SUMMARY... Strong thunderstorms may impact western Utah and adjacent portions of the Great Basin late Monday night, perhaps accompanied by at least some risk for potentially damaging wind gusts. ...Discussion... Within the westerlies, models indicate substantive further amplification of mid-level ridging along an axis from the Upper Midwest into Hudson Bay during this period. As this occurs, downstream troughing is forecast to dig east-southeast of the Canadian Maritimes and north Atlantic coast, with an associated surface cold front advancing as far south as the Mid Atlantic Coast states and Ohio Valley by 12Z Tuesday. Within much weaker troughing off the south Atlantic coast, to the south of this feature, Humberto may intensify to hurricane strength, but is expected to be in the process of accelerating eastward away from the coast, through the western Atlantic. Meanwhile, as another significant short wave impulse digs southeast of the Gulf of Alaska, to the west of the British Columbia coast, initially amplified upper troughing near the Pacific coast is expected to increasingly split. One emerging short wave trough is forecast to accelerate across and northeast of the Canadian Rockies, while a more significant impulse to the south pivots inland of the Oregon and California coast, toward the northern Rockies. Strong forcing for ascent and wind fields/vertical shear associated with the trailing impulse may contribute to the best potential for any appreciable severe weather risk during this period. However, it appears that this probably will be tempered by drying over the Great Basin in the wake of a preceding short wave impulse, emerging from the lower latitudes ahead of the inland advancing troughing. Of most concern at the present time, at least some model output suggests that a return flow of monsoonal moisture could develop in a narrow plume, ahead the vigorous short wave and associated cold front, across western Utah by late Monday night. This could contribute to sufficient destabilization for the initiation of storms prior to 17/09-12Z, west of the Wasatch into the Great Salt Lake vicinity, where southwesterly flow in the 700-500 mb layer may strengthen to 40-70 kt. With relatively dry sub-cloud air contributing to evaporative cooling in downdrafts, downward mixing of higher momentum air may result in strong surface gusts. ..Kerr.. 09/14/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sat Sep 14 2019 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE MONDAY NIGHT ACROSS WESTERN UTAH AND ADJACENT PORTIONS OF THE GREAT BASIN... ...SUMMARY... Strong thunderstorms may impact western Utah and adjacent portions of the Great Basin late Monday night, perhaps accompanied by at least some risk for potentially damaging wind gusts. ...Discussion... Within the westerlies, models indicate substantive further amplification of mid-level ridging along an axis from the Upper Midwest into Hudson Bay during this period. As this occurs, downstream troughing is forecast to dig east-southeast of the Canadian Maritimes and north Atlantic coast, with an associated surface cold front advancing as far south as the Mid Atlantic Coast states and Ohio Valley by 12Z Tuesday. Within much weaker troughing off the south Atlantic coast, to the south of this feature, Humberto may intensify to hurricane strength, but is expected to be in the process of accelerating eastward away from the coast, through the western Atlantic. Meanwhile, as another significant short wave impulse digs southeast of the Gulf of Alaska, to the west of the British Columbia coast, initially amplified upper troughing near the Pacific coast is expected to increasingly split. One emerging short wave trough is forecast to accelerate across and northeast of the Canadian Rockies, while a more significant impulse to the south pivots inland of the Oregon and California coast, toward the northern Rockies. Strong forcing for ascent and wind fields/vertical shear associated with the trailing impulse may contribute to the best potential for any appreciable severe weather risk during this period. However, it appears that this probably will be tempered by drying over the Great Basin in the wake of a preceding short wave impulse, emerging from the lower latitudes ahead of the inland advancing troughing. Of most concern at the present time, at least some model output suggests that a return flow of monsoonal moisture could develop in a narrow plume, ahead the vigorous short wave and associated cold front, across western Utah by late Monday night. This could contribute to sufficient destabilization for the initiation of storms prior to 17/09-12Z, west of the Wasatch into the Great Salt Lake vicinity, where southwesterly flow in the 700-500 mb layer may strengthen to 40-70 kt. With relatively dry sub-cloud air contributing to evaporative cooling in downdrafts, downward mixing of higher momentum air may result in strong surface gusts. ..Kerr.. 09/14/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NV...NORTHEAST CA...SOUTHEAST OR...SOUTHWEST ID... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL/EASTERN NV... ...Synopsis... A vigorous upper trough is forecast to amplify and shift eastward across the Pacific Coast into the Great Basin/interior Northwest by Monday morning. At the surface, low pressure will deepen from the northern Great Basin into portions of the northern High Plains, with a surface trough extending southward into the central/southern High Plains. ...Great Basin and vicinity... As low/midlevel flow increases in advance of the strong upper trough, a broad area of elevated to potentially critical fire weather conditions is forecast to develop from the Great Basin and vicinity eastward into portions of southern WY. Within this region, critical conditions are likely over northwest NV and adjacent portions of northeast CA, southeast OR, and far southwest ID. In this area, sustained winds of 20-30 mph will combine with minimum RH values of 8-15%, with localized areas of extremely critical conditions possible. Another region of potentially critical conditions is forecast over portions of central/eastern NV, where sustained winds of 15-25 mph are forecast in conjunction with minimum RH values of 10-15%. The onset of critical conditions in these areas may occur as early as late morning, with critical conditions potentially persisting into late Sunday night across the westernmost critical area. ..Dean.. 09/14/2019 ...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 0100 AM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NV...NORTHEAST CA...SOUTHEAST OR...SOUTHWEST ID... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL/EASTERN NV... ...Synopsis... A vigorous upper trough is forecast to amplify and shift eastward across the Pacific Coast into the Great Basin/interior Northwest by Monday morning. At the surface, low pressure will deepen from the northern Great Basin into portions of the northern High Plains, with a surface trough extending southward into the central/southern High Plains. ...Great Basin and vicinity... As low/midlevel flow increases in advance of the strong upper trough, a broad area of elevated to potentially critical fire weather conditions is forecast to develop from the Great Basin and vicinity eastward into portions of southern WY. Within this region, critical conditions are likely over northwest NV and adjacent portions of northeast CA, southeast OR, and far southwest ID. In this area, sustained winds of 20-30 mph will combine with minimum RH values of 8-15%, with localized areas of extremely critical conditions possible. Another region of potentially critical conditions is forecast over portions of central/eastern NV, where sustained winds of 15-25 mph are forecast in conjunction with minimum RH values of 10-15%. The onset of critical conditions in these areas may occur as early as late morning, with critical conditions potentially persisting into late Sunday night across the westernmost critical area. ..Dean.. 09/14/2019 ...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 0100 AM CDT Sat Sep 14 2019 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHWEST NV...NORTHEAST CA...SOUTHEAST OR...SOUTHWEST ID... ...CRITICAL FIRE WEATHER AREA FOR CENTRAL/EASTERN NV... ...Synopsis... A vigorous upper trough is forecast to amplify and shift eastward across the Pacific Coast into the Great Basin/interior Northwest by Monday morning. At the surface, low pressure will deepen from the northern Great Basin into portions of the northern High Plains, with a surface trough extending southward into the central/southern High Plains. ...Great Basin and vicinity... As low/midlevel flow increases in advance of the strong upper trough, a broad area of elevated to potentially critical fire weather conditions is forecast to develop from the Great Basin and vicinity eastward into portions of southern WY. Within this region, critical conditions are likely over northwest NV and adjacent portions of northeast CA, southeast OR, and far southwest ID. In this area, sustained winds of 20-30 mph will combine with minimum RH values of 8-15%, with localized areas of extremely critical conditions possible. Another region of potentially critical conditions is forecast over portions of central/eastern NV, where sustained winds of 15-25 mph are forecast in conjunction with minimum RH values of 10-15%. The onset of critical conditions in these areas may occur as early as late morning, with critical conditions potentially persisting into late Sunday night across the westernmost critical area. ..Dean.. 09/14/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Sat Sep 14 2019 Valid 141200Z - 151200Z ...Synopsis... An upper trough is forecast to approach the Pacific Northwest by late tonight, as a downstream shortwave trough moves quickly across the northern Plains. At the surface, broad low pressure will remain in place across south-central Canada, with a surface trough extending into portions of the central/northern High Plains. ...Southern WY... Low-level westerly flow will become established across southern WY this afternoon, to the west of the surface trough over the central/northern High Plains. Drying/mixing within a westerly flow regime will result in minimum RH values dropping to 10-20% this afternoon, in conjunction with sustained winds of 15-25 mph. These conditions will result in elevated fire weather conditions, with the best chance of locally critical conditions expected across portions of southeast WY. ...Northwest Great Basin and Vicinity... In advance of the upper trough, a gradual increase in low-level southwesterly flow is expected across portions of the northwest Great Basin and vicinity. Sustained winds may approach or exceed 15 mph within a hot and dry airmass characterized by minimum RH values of 10-15%, resulting in the potential for elevated fire weather conditions. As flow continues to increase into Sunday morning, mid/high elevation regions that remain above the nocturnal inversion for a longer period of time may see elevated conditions persist into the overnight hours. ..Dean.. 09/14/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more