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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun Sep 15 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE EASTERN GREAT BASIN TO FOUR CORNERS...THE RED RIVER VALLEY OF THE NORTH...AND EASTERN NC... ...SUMMARY... On Monday, sporadic severe gusts and marginally severe hail will be possible during the afternoon to early evening across parts of the eastern Great Basin to Four Corners. Isolated, marginally severe storms are possible over eastern North Dakota into northwest Minnesota during the late afternoon and evening. A low-probability tornado threat may develop over eastern North Carolina. ...Eastern Great Basin to the Four Corners... An amplified mid-level low near the Bay Area at 12Z Monday should initially move east before curling northeast Monday night towards the NV/UT/ID border area. This will occur in response to a strong mid-level jet translating through the basal portion of the large-scale trough across the Desert Southwest into the eastern Great Basin. Convection should be ongoing Monday morning immediately ahead of the mid-level low and separately in the low-level warm/moist conveyor over the Four Corners region. Greater boundary-layer heating should occur between these two regimes across eastern NV into UT, west of the Wasatch Range. Despite meager MLCAPE, the deepening boundary layer amid a strengthening meridional wind profile should yield efficient downward mixing. This will be further augmented by evaporatively cooled downdraft accelerations and promote a threat for sporadic severe gusts. Farther southeast, a more southwesterly mid to upper-flow regime should yield hodograph elongation, supporting a few splitting supercells. Warmer mid-level temperatures and correspondingly weaker lapse rates will temper parcel acceleration to an extent, but this may be offset by somewhat higher PW values. Marginal severe hail/gusts will be possible. ...Eastern ND to northwest MN... With the primary upper-level trough displaced well to the west, deep-layer shear will remain weak across much of the Great Plains. However, most guidance suggests an MCV will emanate out of D1 central High Plains convection and gradually progress northeast towards the Red River Valley. In conjunction with the northern nose of a strengthening central to northern Great Plains low-level jet, a focused corridor for regenerative thunderstorm development may occur during the late afternoon and evening. Some low-level hodograph enlargement should support a predominantly clustered convective mode, with transient supercell structures possible. An isolated, lower-end severe hail/wind threat may develop, and a brief tornado is also possible. ...Coastal NC... While guidance consensus increasingly favors offshore cyclogenesis, the amplitude of this development along with timing of inland progression remain quite varied for a D2 forecast. The 00Z NAM and some of the 18Z ECMWF ENS members suggest particularly robust deepening will occur. The more aggressive scenarios would yield substantial enlargement of low-level hodographs, likely becoming coupled with a narrow swath of high theta-e air spreading west-northwestward from the Gulf Stream. Given the potential range of scenarios from nil threat to multiple tornadic supercells, a low-probability tornado highlight appears warranted. ..Grams.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Sep 15 2024 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms capable of isolated severe gusts and hail will be possible today across parts of the central and northern High Plains. ...Central and Northern High Plains... An upper-level low will move southward along the West Coast today, as southwest mid-level flow remains over much of the western third of the U.S. A subtle shortwave trough is forecast to move northeastward through the central Rockies. Ahead of the trough, a moist airmass will be in place in the central and northern Plains, where surface dewpoints will mostly be from the upper 50s to the mid 60s F. As surface temperatures warm, moderate instability is expected to develop over much of this airmass. MLCAPE is forecast to peak in the 2000 to 3000 J/kg range in areas that heat up the most. The instability axis is forecast to be located from northwest Kansas northward into western Nebraska and southwest South Dakota by mid to late afternoon. At this time, RAP forecast soundings near the instability axis have low to mid-level lapse rates exceeding 8 C/km, and enough deep-layer shear for a marginal severe threat. Isolated severe gusts and hail will be possible with the stronger cells, mainly during the late afternoon and early evening. ..Broyles/Weinman.. 09/15/2024 Read more

5-Day Uncertainty Track last updated Sun, 15 Sep 2024 05:39:23 GMT


Wind Speed Probabilities last updated Sun, 15 Sep 2024 03:28:37 GMT

Issued at 1100 PM MST Sat Sep 14 2024 000 WTPZ34 KNHC 150539 TCPEP4 BULLETIN Tropical Storm Ileana Intermediate Advisory Number 11A NWS National Hurricane Center Miami FL EP092024 1100 PM MST Sat Sep 14 2024 ...ILEANA WEAKENING WHILE MEANDERING JUST OFFSHORE NORTHERN SINALOA... SUMMARY OF 1100 PM MST...0600 UTC...INFORMATION ----------------------------------------------- LOCATION...25.4N 109.2W ABOUT 30 MI...50 KM SSW OF LOS MOCHIS MEXICO MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Altata to Huatabampito Mexico A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case during the next few hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM MST (0600 UTC), the center of Tropical Storm Ileana was located near latitude 25.4 North, longitude 109.2 West. Ileana is meandering off the coast of northern Sinaloa but has a longer-term motion toward the west-northwest near 2 mph (4 km/h). A turn toward the northwest is expected soon with an increase in forward speed. On the forecast track, the center of Ileana will move near the coastal region of northern Sinaloa overnight, and then move over the Gulf of California roughly parallel to the coast on Sunday. Maximum sustained winds have begun decreasing and are now near 40 mph (65 km/h) with higher gusts. Additional weakening is forecast, and Ileana is expected to degenerate into a remnant low on Sunday. The remnant low is expected to dissipate by Monday. Tropical-storm-force winds extend outward up to 60 miles (95 km) from the center. The estimated minimum central pressure is 1004 mb (29.65 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Ileana can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4 and WMO header WTPZ44 KNHC. RAINFALL: Tropical Storm Ileana is expected to bring additional rainfall amounts of 3 to 6 inches, with localized higher amounts up to 10 inches, across northwest coastal Sinaloa through this weekend. For a complete depiction of forecast rainfall associated with Tropical Storm Ileana, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_ep4.shtml?rainqpf WIND: Tropical storm conditions, especially in gusts, are expected across portions of the warning area in northern Sinaloa and southern Sonora during the next few hours. SURF: Swells generated by Ileana will affect portions of the Gulf of California coasts of Sinaloa, southern Sonora, and southern Baja California Sur during the next day or so. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 200 AM MST. $$ Forecaster Berg

...ILEANA WEAKENING WHILE MEANDERING JUST OFFSHORE NORTHERN SINALOA... As of 11:00 PM MST Sat Sep 14 the center of Ileana was located near 25.4, -109.2 with movement WNW at 2 mph. The minimum central pressure was 1004 mb with maximum sustained winds of about 40 mph.

000
ABPZ20 KNHC 150524
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sat Sep 14 2024

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

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Ileana, located near the coast of northern Sinaloa, Mexico.

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Berg

5-Day Uncertainty Track last updated Sun, 15 Sep 2024 02:39:47 GMT


Wind Speed Probabilities last updated Sun, 15 Sep 2024 03:28:37 GMT

Issued at 800 PM MST Sat Sep 14 2024 000 WTPZ44 KNHC 150237 TCDEP4 Tropical Storm Ileana Discussion Number 11 NWS National Hurricane Center Miami FL EP092024 800 PM MST Sat Sep 14 2024 Ileana has stalled near the coast of northwestern Mexico, offshore of the state of Sinaloa. All of the deep convection has moved inland, as indicated by both the radar and satellite imagery, leaving the low-level circulation exposed. Surface observations from Topolobampo and Los Mochis recently measured sustained winds of 39 kt, with higher gusts. Based on these data, the initial intensity for this cycle is raised to 40 kt. The storm is drifting with an uncertain motion of 360/1 kt. Ileana is still expected to turn northwestward soon and gradually accelerate, bringing the center across the northern coastal region of Sinaloa during the next 12 h. By Sunday, the cyclone is forecast to be near the coast of southern Sonora and stay roughly parallel to the coast of Mexico over the Gulf of California until the system dissipates. The new track forecast is again nudged to the north and east of the previous track and lies near the various consensus models. Despite strong southwesterly vertical wind shear decoupling Ileana's surface circulation from its deep convection, the surface winds have yet to weaken. Global models indicated that deep organized convection should not reform and therefore Ileana is expected to become a post-tropical cyclone by Sunday. The system should gradually weaken due to the interaction with land and surrounding dry air and strong vertical wind shear. The official forecast shows Ileana dissipating by late Monday, though some numerical guidance suggests this could occur sooner. Key Messages: 1. Tropical Storm Ileana will bring heavy rainfall to portions of coastal Sinaloa, Mexico through this weekend. This heavy rainfall will bring a risk of flash flooding and mudslides to portions of the area. 2. Tropical storm conditions are expected within the warning area of northern Sinaloa and southern Sonora through Sunday. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 25.5N 109.0W 40 KT 45 MPH 12H 15/1200Z 25.7N 109.2W 35 KT 40 MPH...POST-TROPICAL 24H 16/0000Z 26.4N 109.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 16/1200Z 27.4N 110.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 17/0000Z...DISSIPATED $$ Forecaster Bucci

Issued at 0300 UTC SUN SEP 15 2024 000 FOPZ14 KNHC 150236 PWSEP4 TROPICAL STORM ILEANA WIND SPEED PROBABILITIES NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092024 0300 UTC SUN SEP 15 2024 AT 0300Z THE CENTER OF TROPICAL STORM ILEANA WAS LOCATED NEAR LATITUDE 25.5 NORTH...LONGITUDE 109.0 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 00Z SUN AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 00Z SUN 12Z SUN 00Z MON 12Z MON 00Z TUE 00Z WED 00Z THU PERIODS TO TO TO TO TO TO TO 12Z SUN 00Z MON 12Z MON 00Z TUE 00Z WED 00Z THU 00Z FRI FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT GUAYMAS 34 X X( X) 3( 3) X( 3) X( 3) X( 3) X( 3) HUATABAMPO 34 1 4( 5) 1( 6) X( 6) X( 6) X( 6) X( 6) LOS MOCHIS 34 99 X(99) X(99) X(99) X(99) X(99) X(99) $$ FORECASTER BUCCI

Issued at 800 PM MST Sat Sep 14 2024 000 WTPZ34 KNHC 150235 TCPEP4 BULLETIN Tropical Storm Ileana Advisory Number 11 NWS National Hurricane Center Miami FL EP092024 800 PM MST Sat Sep 14 2024 ...ILEANA MEANDERING NEAR THE COAST OF NORTHWESTERN MEXICO... ...BRINGING TROPICAL STORM CONDITIONS TO SINALOA... SUMMARY OF 800 PM MST...0300 UTC...INFORMATION ---------------------------------------------- LOCATION...25.5N 109.0W ABOUT 20 MI...35 KM S OF LOS MOCHIS MEXICO MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Altata to Huatabampito Mexico A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within 12 hours. Interests elsewhere in the Mexican states of Sinaloa and Sonora should closely monitor the progress of Ileana. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 800 PM MST (0300 UTC), the center of Tropical Storm Ileana was located near latitude 25.5 North, longitude 109.0 West. Ileana is drifting toward the north near 2 mph (4 km/h). A turn toward the northwest is expected soon with an increase in forward speed. On the forecast track, the center of Ileana will move near, or over the coastal region of northern Sinaloa during the next several hours, and then move over the Gulf of California roughly parallel to the coast on Sunday. Maximum sustained winds have increased to near 45 mph (75 km/h) with higher gusts. Weakening is forecast to begin overnight, and Ileana is likely to degenerate into a remnant low on Sunday. The remnant low is expected to dissipate by Monday. Tropical-storm-force winds extend outward up to 60 miles (95 km) from the center. The Mexican Navy station at Topolobampo recently reported sustained winds of 45 mph (72 km/h) and a wind gust of 58 mph (93 km/h). The estimated minimum central pressure is 1000 mb (29.53 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Ileana can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP4 and WMO header WTPZ44 KNHC. RAINFALL: Tropical Storm Ileana is expected to bring additional rainfall amounts of 3 to 6 inches, with localized higher amounts up to 10 inches, across northwest coastal Sinaloa through this weekend. For a complete depiction of forecast rainfall associated with Tropical Storm Ileana, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_ep4.shtml?rainqpf WIND: Tropical storm conditions are expected across portions of the warning area in northern Sinaloa and southern Sonora into Sunday. SURF: Swells generated by Ileana will affect portions of the Gulf of California coasts of Sinaloa, southern Sonora, and southern Baja California Sur during the next day or so. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 1100 PM MST. Next complete advisory at 200 AM MST. $$ Forecaster Bucci

...ILEANA MEANDERING NEAR THE COAST OF NORTHWESTERN MEXICO... ...BRINGING TROPICAL STORM CONDITIONS TO SINALOA... As of 8:00 PM MST Sat Sep 14 the center of Ileana was located near 25.5, -109.0 with movement N at 2 mph. The minimum central pressure was 1000 mb with maximum sustained winds of about 45 mph.

Issued at 0300 UTC SUN SEP 15 2024 000 WTPZ24 KNHC 150235 TCMEP4 TROPICAL STORM ILEANA FORECAST/ADVISORY NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092024 0300 UTC SUN SEP 15 2024 TROPICAL STORM CENTER LOCATED NEAR 25.5N 109.0W AT 15/0300Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTH OR 360 DEGREES AT 2 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1000 MB MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT. 34 KT....... 50NE 50SE 0SW 30NW. 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 25.5N 109.0W AT 15/0300Z AT 15/0000Z CENTER WAS LOCATED NEAR 25.4N 109.0W FORECAST VALID 15/1200Z 25.7N 109.2W...POST-TROPICAL MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 30NE 0SE 0SW 30NW. FORECAST VALID 16/0000Z 26.4N 109.9W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 16/1200Z 27.4N 110.8W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 17/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 25.5N 109.0W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPEP4...AT 15/0600Z NEXT ADVISORY AT 15/0900Z $$ FORECASTER BUCCI

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0819 PM CDT Sat Sep 14 2024 Valid 150100Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... CORRECTED FOR FLIPPED THUNDER LINE ...SUMMARY... Thunderstorms capable of producing isolated severe gusts and hail will be possible this evening over parts of the central and northern Plains. ...Central and Northern Plains... The latest water vapor imagery shows a shortwave trough over the Dakotas extending southward into northern Nebraska. Along this corridor, the RAP has a two distinct vorticity maxima analyzed. At the surface, a trough is located in the northern High Plains, and a moist airmass is present over much of the central and northern Plains. Surface dewpoints within this moist airmass vary from the mid 50s to mid 60s F. The RAP suggests that moderate instability is present from west-central Nebraska into parts of the Dakotas, where isolated to scattered thunderstorms are ongoing. The North Platte 00Z sounding has the best severe environment regionally, with MLCAPE near 1500 J/kg, and 0-3 km shear around 35 knots. On this sounding, the average low to mid-level lapse rate is near 7.5 C/km. This, along with instability and shear suggest that a marginal severe threat will likely continue for a few more hours. Isolated severe gusts and hail will be possible with rotating cells. The threat is expected to diminish during the mid to late evening as instability decreases across the region. ..Broyles.. 09/15/2024 Read more