Aggregator

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

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

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

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1152 PM CDT Fri Sep 13 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across U.S. Sunday through Sunday night. ...Discussion... Substantial further amplification within the mid-latitude westerlies appears likely during this period. While models indicate large-scale troughing will continue to dig along an axis near/just west of the Pacific coast, downstream ridging is forecast to build across and north of the Canadian/U.S. border, east of the Rockies through Ontario and the Great Lakes region. In advance (east) of the troughing, models suggest that a much weaker perturbation emerging from the lower latitudes will gradually accelerate north of the Southwestern international border area, through the Four Corners region. Although this may be preceded by considerable lingering convectively generated cloud cover and precipitation, which appears likely to limit or slow daytime heating, destabilization in its wake may still be sufficient to support scattered afternoon and evening thunderstorm activity. Elsewhere, thunderstorms developing Saturday night, mostly in response to forcing associated with low-level warm advection, may linger into Sunday morning across parts of the Upper Midwest and Great Lakes region. However, it still appears that this activity will diminish early, with low to negligible probabilities for redevelopment as mid-level ridging builds into the region. Additionally, low probabilities for convection capable of producing lightning may develop into Washington/Oregon coastal areas by Sunday evening, in response to destabilization associated with strong mid-level cooling. There appears some risk for thunderstorms near northwest Gulf coastal areas, in association with a slow moving perturbation within the easterlies, over the western Gulf of Mexico. Isolated to widely scattered afternoon thunderstorm development may not be out of the question across parts of the Florida peninsula, well to the southwest of Humberto. With Humberto now forecast to track along a path well offshore of the Southeast coast, severe weather potential appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 09/14/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1152 PM CDT Fri Sep 13 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across U.S. Sunday through Sunday night. ...Discussion... Substantial further amplification within the mid-latitude westerlies appears likely during this period. While models indicate large-scale troughing will continue to dig along an axis near/just west of the Pacific coast, downstream ridging is forecast to build across and north of the Canadian/U.S. border, east of the Rockies through Ontario and the Great Lakes region. In advance (east) of the troughing, models suggest that a much weaker perturbation emerging from the lower latitudes will gradually accelerate north of the Southwestern international border area, through the Four Corners region. Although this may be preceded by considerable lingering convectively generated cloud cover and precipitation, which appears likely to limit or slow daytime heating, destabilization in its wake may still be sufficient to support scattered afternoon and evening thunderstorm activity. Elsewhere, thunderstorms developing Saturday night, mostly in response to forcing associated with low-level warm advection, may linger into Sunday morning across parts of the Upper Midwest and Great Lakes region. However, it still appears that this activity will diminish early, with low to negligible probabilities for redevelopment as mid-level ridging builds into the region. Additionally, low probabilities for convection capable of producing lightning may develop into Washington/Oregon coastal areas by Sunday evening, in response to destabilization associated with strong mid-level cooling. There appears some risk for thunderstorms near northwest Gulf coastal areas, in association with a slow moving perturbation within the easterlies, over the western Gulf of Mexico. Isolated to widely scattered afternoon thunderstorm development may not be out of the question across parts of the Florida peninsula, well to the southwest of Humberto. With Humberto now forecast to track along a path well offshore of the Southeast coast, severe weather potential appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 09/14/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1152 PM CDT Fri Sep 13 2019 Valid 151200Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across U.S. Sunday through Sunday night. ...Discussion... Substantial further amplification within the mid-latitude westerlies appears likely during this period. While models indicate large-scale troughing will continue to dig along an axis near/just west of the Pacific coast, downstream ridging is forecast to build across and north of the Canadian/U.S. border, east of the Rockies through Ontario and the Great Lakes region. In advance (east) of the troughing, models suggest that a much weaker perturbation emerging from the lower latitudes will gradually accelerate north of the Southwestern international border area, through the Four Corners region. Although this may be preceded by considerable lingering convectively generated cloud cover and precipitation, which appears likely to limit or slow daytime heating, destabilization in its wake may still be sufficient to support scattered afternoon and evening thunderstorm activity. Elsewhere, thunderstorms developing Saturday night, mostly in response to forcing associated with low-level warm advection, may linger into Sunday morning across parts of the Upper Midwest and Great Lakes region. However, it still appears that this activity will diminish early, with low to negligible probabilities for redevelopment as mid-level ridging builds into the region. Additionally, low probabilities for convection capable of producing lightning may develop into Washington/Oregon coastal areas by Sunday evening, in response to destabilization associated with strong mid-level cooling. There appears some risk for thunderstorms near northwest Gulf coastal areas, in association with a slow moving perturbation within the easterlies, over the western Gulf of Mexico. Isolated to widely scattered afternoon thunderstorm development may not be out of the question across parts of the Florida peninsula, well to the southwest of Humberto. With Humberto now forecast to track along a path well offshore of the Southeast coast, severe weather potential appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 09/14/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Sat Sep 14 2019 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MS VALLEY AND CENTRAL PLAINS AND OVER PARTS OF AZ... ...SUMMARY... A few strong-severe storms are possible across portions of the upper Mississippi Valley, extending southwest into the central Plains. Locally damaging winds are the primary risk along with marginally severe hail. Gusty winds may also accompany storms in the lower desert regions of AZ. ...Upper MS Valley to Central Plains... Notable short-wave trough over the northern Rockies is forecast to progress across the Dakotas into the upper MS Valley by 15/00z. While southern extent of this feature should influence northern portions of the MRGL Risk late this afternoon, large-scale height rises are expected across much of the central US, including the Plains and MS Valley. Partly in response to this feature, LLJ should increase across the central Plains before veering into WI by early evening. This will allow higher-PW air mass to advance north, then east into southern MN/IA by peak heating. Even so, forecast soundings suggest surface parcels will struggle to reach convective temperatures and low-level warm advection may ultimately be the primary forcing mechanism for potential robust convective development. Latest models support this with most guidance suggesting warm-sector convection struggling to organize in the presence of height rises and marginal low-level lapse rates. However, isentropic ascent across southern MN into southwest WI should encourage slightly elevated convection along nose of LLJ. Some of this activity could produce gusty winds and perhaps some hail. Farther southwest across KS, strong boundary-layer heating will be noted across the High Plains where surface temperatures should soar into the mid 90s. Forecast soundings suggest convective temperatures will be breached by 23z and isolated high-based convection is expected to develop across southwest KS which could spread/develop northeast along the boundary into south-central NE. Gusty winds and hail are the primary threats with the diurnally-driven activity. ...AZ... A considerable amount of deep convection developed over the higher terrain of northwestern Mexico ahead of what appears to be a weak short-wave trough. This low-latitude wave should drift toward the Gulf of California which will allow for more favorable trajectories to transport moisture north of the international border into AZ. With PWs expected to climb well above 1", strong boundary-layer heating should contribute to increasing buoyancy that will prove supportive of robust convection. Forecast soundings suggest deep convection will develop as early as 19z across southeast AZ, then spread/develop west toward the lower deserts. A considerable amount of convection may ultimately evolve across this region and gusty winds are certainly possible given the increasingly wet downdrafts. ..Darrow/Dean.. 09/14/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Sat Sep 14 2019 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MS VALLEY AND CENTRAL PLAINS AND OVER PARTS OF AZ... ...SUMMARY... A few strong-severe storms are possible across portions of the upper Mississippi Valley, extending southwest into the central Plains. Locally damaging winds are the primary risk along with marginally severe hail. Gusty winds may also accompany storms in the lower desert regions of AZ. ...Upper MS Valley to Central Plains... Notable short-wave trough over the northern Rockies is forecast to progress across the Dakotas into the upper MS Valley by 15/00z. While southern extent of this feature should influence northern portions of the MRGL Risk late this afternoon, large-scale height rises are expected across much of the central US, including the Plains and MS Valley. Partly in response to this feature, LLJ should increase across the central Plains before veering into WI by early evening. This will allow higher-PW air mass to advance north, then east into southern MN/IA by peak heating. Even so, forecast soundings suggest surface parcels will struggle to reach convective temperatures and low-level warm advection may ultimately be the primary forcing mechanism for potential robust convective development. Latest models support this with most guidance suggesting warm-sector convection struggling to organize in the presence of height rises and marginal low-level lapse rates. However, isentropic ascent across southern MN into southwest WI should encourage slightly elevated convection along nose of LLJ. Some of this activity could produce gusty winds and perhaps some hail. Farther southwest across KS, strong boundary-layer heating will be noted across the High Plains where surface temperatures should soar into the mid 90s. Forecast soundings suggest convective temperatures will be breached by 23z and isolated high-based convection is expected to develop across southwest KS which could spread/develop northeast along the boundary into south-central NE. Gusty winds and hail are the primary threats with the diurnally-driven activity. ...AZ... A considerable amount of deep convection developed over the higher terrain of northwestern Mexico ahead of what appears to be a weak short-wave trough. This low-latitude wave should drift toward the Gulf of California which will allow for more favorable trajectories to transport moisture north of the international border into AZ. With PWs expected to climb well above 1", strong boundary-layer heating should contribute to increasing buoyancy that will prove supportive of robust convection. Forecast soundings suggest deep convection will develop as early as 19z across southeast AZ, then spread/develop west toward the lower deserts. A considerable amount of convection may ultimately evolve across this region and gusty winds are certainly possible given the increasingly wet downdrafts. ..Darrow/Dean.. 09/14/2019 Read more

000
ABPZ20 KNHC 140543
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Fri Sep 13 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.

Disorganized showers located about 1800 miles west-southwest of the
southern tip of the Baja California peninsula are associated with
an elongated trough of low pressure. Development of this system is
not expected as it begins to drift eastward into the larger
circulation of Tropical Storm Kiko during the next several days.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...near 0 percent.

Recent satellite-derived wind data indicate that a weak area of low
pressure has developed along an elongated trough about 500 miles
south-southwest of Acapulco, Mexico. This disturbance is producing
a large area of disorganized cloudiness, 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.

Satellite-derived wind data also indicate that a broad area of low
pressure is developing 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 Berg

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Sat Sep 14 2019 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MS VALLEY AND CENTRAL PLAINS AND OVER PARTS OF AZ... ...SUMMARY... A few strong-severe storms are possible across portions of the upper Mississippi Valley, extending southwest into the central Plains. Locally damaging winds are the primary risk along with marginally severe hail. Gusty winds may also accompany storms in the lower desert regions of AZ. ...Upper MS Valley to Central Plains... Notable short-wave trough over the northern Rockies is forecast to progress across the Dakotas into the upper MS Valley by 15/00z. While southern extent of this feature should influence northern portions of the MRGL Risk late this afternoon, large-scale height rises are expected across much of the central US, including the Plains and MS Valley. Partly in response to this feature, LLJ should increase across the central Plains before veering into WI by early evening. This will allow higher-PW air mass to advance north, then east into southern MN/IA by peak heating. Even so, forecast soundings suggest surface parcels will struggle to reach convective temperatures and low-level warm advection may ultimately be the primary forcing mechanism for potential robust convective development. Latest models support this with most guidance suggesting warm-sector convection struggling to organize in the presence of height rises and marginal low-level lapse rates. However, isentropic ascent across southern MN into southwest WI should encourage slightly elevated convection along nose of LLJ. Some of this activity could produce gusty winds and perhaps some hail. Farther southwest across KS, strong boundary-layer heating will be noted across the High Plains where surface temperatures should soar into the mid 90s. Forecast soundings suggest convective temperatures will be breached by 23z and isolated high-based convection is expected to develop across southwest KS which could spread/develop northeast along the boundary into south-central NE. Gusty winds and hail are the primary threats with the diurnally-driven activity. ...AZ... A considerable amount of deep convection developed over the higher terrain of northwestern Mexico ahead of what appears to be a weak short-wave trough. This low-latitude wave should drift toward the Gulf of California which will allow for more favorable trajectories to transport moisture north of the international border into AZ. With PWs expected to climb well above 1", strong boundary-layer heating should contribute to increasing buoyancy that will prove supportive of robust convection. Forecast soundings suggest deep convection will develop as early as 19z across southeast AZ, then spread/develop west toward the lower deserts. A considerable amount of convection may ultimately evolve across this region and gusty winds are certainly possible given the increasingly wet downdrafts. ..Darrow/Dean.. 09/14/2019 Read more

5-Day Uncertainty Track last updated Sat, 14 Sep 2019 02:42:33 GMT


Wind Speed Probabilities last updated Sat, 14 Sep 2019 03:29:50 GMT