Marine Weather and Tide Forecast for Sergeant Bluff, IA
May 19, 2024 12:35 PM CDT (17:35 UTC) Change Location
 | Sunrise 5:57 AM Sunset 8:46 PM Moonrise 4:05 PM Moonset 3:01 AM |
Area Discussion for - Sioux Falls, SD
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FXUS63 KFSD 191712 AFDFSD
Area Forecast Discussion National Weather Service Sioux Falls SD 1212 PM CDT Sun May 19 2024
KEY MESSAGES
- Scattered showers and thunderstorms spread in this morning with gusty south winds.
- Additional storms developing and/or moving through this evening and overnight bring potential for isolated strong to severe thunderstorms (SPC Level 1 of 5 risk). Large hail is the primary threat with locally heavy downpours and damaging wind gusts being secondary.
- Confidence is increasing in a widespread heavy rain with storms Monday night through Tuesday morning. During this 24-hour period, high confidence (>70%) in a widespread 1+" and a moderate chance (40-60%) of a widespread 2+" of rain with some locations possibly exceeding 3".
- Isolated severe thunderstorms are possible Monday night with a SPC level 1 of 5 risk near and south of a line from Jackson MN to Sioux Falls SD to Lake Andes SD.
- Scattered severe thunderstorms are possible Tuesday afternoon with a SPC level 2 of 5 risk across much of northwest Iowa and far eastern Nebraska.
DISCUSSION
Issued at 431 AM CDT Sun May 19 2024
TODAY: Early this morning, dry surface high pressure builds eastward and GOES-16 satellite images shows an area of scattered showers and storms tracking northeast through NE. 00z high resolution model guidance suggests this subtle mid level wave will take more northeasterly track than previously expected, resulting in high chances for scattered showers and storms across northeast NE and northwest IA this morning. Further northwest, another area of elevated showers has developed along the nocturnal low level jet nosing into central SD, ahead of a sfc low in eastern WY. Expect this activity to translate east into eastern SD with the warm sector through the morning and early afternoon, though there is lower confidence in exact timing and how far south rain would extend. The 00z NAMNest seems to have captured ongoing activity the best, so have slightly favored this guidance in the rain chances. This would suggest higher confidence in some breaks in the rain for much of the region this afternoon, especially west of I-29.
Cooler today with a southeast breeze. May see gusts in the 30s mix down with showers, but severe weather is not expected until at least mid afternoon due to a largely stable airmass. Persistent cloud cover will make it tough to heat much today. Expect highs in the 70s, aside from perhaps closer to 80 degrees near and west of the James River Valley where mixing into warming air aloft and breaks in the clouds are more likely between waves.
TONIGHT: High-res models suggest potential for late afternoon or early evening storm development as 1000-2000 J/kg MUCAPE develops near and west of the Missouri River. Low confidence on whether this would be in southwest SD or central SD depending on the progression of the dryline/sfc low and whether any more isolated storms could develop out ahead near the sfc warm front. With the stronger upper jet forcing well to our northwest and south, any strong to severe storms would favor multicellular mode and northeastward storm motion, aiding training storms. Modest mid level lapse rates of 6-7 C/km and skinny CAPE favor large hail as the main threat with damaging wind gusts up to 60 mph and locally heavy downpours being secondary. HRRR probability matched mean QPF suggests tonight's storms would produce a swath of at least 0.25" of rain east of the James River Valley and isolated pockets of 0.50-1.00" across portions of southwest MN. High confidence in storms exiting east of the area by sunrise Monday morning.
MONDAY: The sfc low stalls somewhere from southwest MN to north central IA Monday with a stationary front/inverted trough draped southwest through south central NE toward northwest KS. Can't entirely rule out isolated warm air advection showers east of I-29 Monday morning, but guidance continues to favor dry conditions for most of the day. Breaks in the clouds with warm air capped aloft brings a warmer day than Sunday with highs in the 70s and a breezy west (turning northwest or north) wind.
MONDAY NIGHT/TUESDAY: The progressive upper trough digging into the Rockies sends two mid level waves (one weak, one strong) northeast along the stationary front, with the best broad ascent aloft to trigger widespread showers and storms late Monday night through early Tuesday morning. Isolated severe thunderstorms are possible near and south of a line from Jackson to Sioux Falls to Lake Andes with this activity Monday night as the upper jet slides in aloft with 40+ kts deep layer shear and 1000-2000 J/kg MLCAPE nosing into northwest IA. All hazards are possible near the Hwy 20 corridor near the sfc front, but further northwest, the threat will be mainly large hail and damaging wind gusts.
The greater impact Monday night and Tuesday morning will be areas of heavy rainfall as precipitable water values exceed 1.0-1.5", at the 90th to 95th percentile of ensemble climatology for this time of year. Though pockets of 1-2+ inches will be possible with strong to severe storms in northwest IA, the more widespread heavy rainfall is expected near the 700mb low track through eastern SD into west central MN, where deterministic models highlight a swath of 2-3 inches of rain Tuesday morning.
This would likely cause ponding of water in low lying or poor drainage areas and rises on local rivers, as well as perhaps isolated flash flooding.
Showers and storms continue well into Tuesday with potential for another round of severe weather that bears watching Tuesday afternoon and early evening for eastern Nebraska and across Iowa.
Low level moisture pooling just ahead of the sfc low should bring 1000-2500 J/kg MLCAPE. Combined with strong deep layer shear (0-6km at 50+ kts), this suggests if initial surface based supercells can develop in northwest IA (vs further east), all severe hazards are possible.
WEDNESDAY THROUGH FRIDAY: Drier, cooler air moves in behind the strong departing system Tuesday night, but dry conditions are short lived. An active zonal flow weather pattern continues for the second half of the work week. We start off Wednesday morning with temperatures in the 40s to lower 50s. Another weak shortwave brings a low chance of showers Wednesday. By Thursday night, another potent longwave trough slides into the Rockies and drags a cold front through the Plains with potential for another round of showers and storms Thursday night through Friday.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
Issued at 1152 AM CDT Sun May 19 2024
Scattered showers continue to move through portions of the Tri- state area this morning, one area tied to a departing shortwave, and a second area developed on a low level jet. A few showers may continue to move eastward this afternoon as the jet veers in direction more to the southwest. For most, VFR conditions will continue with a gusty southeast wind up to 30 mph.
More uncertainty develops later this evening as a cluster of convection may slide eastward out of western South Dakota.
Additional scattered activity may form later this evening closer to the Tri-state area as the LLJ increases once again.
However, most guidance supports all of this activity moving east of I-29 by 6Z and out of the CWA by 06z. Behind this convection, a period of lower stratus may be possible into Monday morning.
FSD WATCHES/WARNINGS/ADVISORIES
SD...None.
MN...None.
IA...None.
NE...None.
Area Forecast Discussion National Weather Service Sioux Falls SD 1212 PM CDT Sun May 19 2024
KEY MESSAGES
- Scattered showers and thunderstorms spread in this morning with gusty south winds.
- Additional storms developing and/or moving through this evening and overnight bring potential for isolated strong to severe thunderstorms (SPC Level 1 of 5 risk). Large hail is the primary threat with locally heavy downpours and damaging wind gusts being secondary.
- Confidence is increasing in a widespread heavy rain with storms Monday night through Tuesday morning. During this 24-hour period, high confidence (>70%) in a widespread 1+" and a moderate chance (40-60%) of a widespread 2+" of rain with some locations possibly exceeding 3".
- Isolated severe thunderstorms are possible Monday night with a SPC level 1 of 5 risk near and south of a line from Jackson MN to Sioux Falls SD to Lake Andes SD.
- Scattered severe thunderstorms are possible Tuesday afternoon with a SPC level 2 of 5 risk across much of northwest Iowa and far eastern Nebraska.
DISCUSSION
Issued at 431 AM CDT Sun May 19 2024
TODAY: Early this morning, dry surface high pressure builds eastward and GOES-16 satellite images shows an area of scattered showers and storms tracking northeast through NE. 00z high resolution model guidance suggests this subtle mid level wave will take more northeasterly track than previously expected, resulting in high chances for scattered showers and storms across northeast NE and northwest IA this morning. Further northwest, another area of elevated showers has developed along the nocturnal low level jet nosing into central SD, ahead of a sfc low in eastern WY. Expect this activity to translate east into eastern SD with the warm sector through the morning and early afternoon, though there is lower confidence in exact timing and how far south rain would extend. The 00z NAMNest seems to have captured ongoing activity the best, so have slightly favored this guidance in the rain chances. This would suggest higher confidence in some breaks in the rain for much of the region this afternoon, especially west of I-29.
Cooler today with a southeast breeze. May see gusts in the 30s mix down with showers, but severe weather is not expected until at least mid afternoon due to a largely stable airmass. Persistent cloud cover will make it tough to heat much today. Expect highs in the 70s, aside from perhaps closer to 80 degrees near and west of the James River Valley where mixing into warming air aloft and breaks in the clouds are more likely between waves.
TONIGHT: High-res models suggest potential for late afternoon or early evening storm development as 1000-2000 J/kg MUCAPE develops near and west of the Missouri River. Low confidence on whether this would be in southwest SD or central SD depending on the progression of the dryline/sfc low and whether any more isolated storms could develop out ahead near the sfc warm front. With the stronger upper jet forcing well to our northwest and south, any strong to severe storms would favor multicellular mode and northeastward storm motion, aiding training storms. Modest mid level lapse rates of 6-7 C/km and skinny CAPE favor large hail as the main threat with damaging wind gusts up to 60 mph and locally heavy downpours being secondary. HRRR probability matched mean QPF suggests tonight's storms would produce a swath of at least 0.25" of rain east of the James River Valley and isolated pockets of 0.50-1.00" across portions of southwest MN. High confidence in storms exiting east of the area by sunrise Monday morning.
MONDAY: The sfc low stalls somewhere from southwest MN to north central IA Monday with a stationary front/inverted trough draped southwest through south central NE toward northwest KS. Can't entirely rule out isolated warm air advection showers east of I-29 Monday morning, but guidance continues to favor dry conditions for most of the day. Breaks in the clouds with warm air capped aloft brings a warmer day than Sunday with highs in the 70s and a breezy west (turning northwest or north) wind.
MONDAY NIGHT/TUESDAY: The progressive upper trough digging into the Rockies sends two mid level waves (one weak, one strong) northeast along the stationary front, with the best broad ascent aloft to trigger widespread showers and storms late Monday night through early Tuesday morning. Isolated severe thunderstorms are possible near and south of a line from Jackson to Sioux Falls to Lake Andes with this activity Monday night as the upper jet slides in aloft with 40+ kts deep layer shear and 1000-2000 J/kg MLCAPE nosing into northwest IA. All hazards are possible near the Hwy 20 corridor near the sfc front, but further northwest, the threat will be mainly large hail and damaging wind gusts.
The greater impact Monday night and Tuesday morning will be areas of heavy rainfall as precipitable water values exceed 1.0-1.5", at the 90th to 95th percentile of ensemble climatology for this time of year. Though pockets of 1-2+ inches will be possible with strong to severe storms in northwest IA, the more widespread heavy rainfall is expected near the 700mb low track through eastern SD into west central MN, where deterministic models highlight a swath of 2-3 inches of rain Tuesday morning.
This would likely cause ponding of water in low lying or poor drainage areas and rises on local rivers, as well as perhaps isolated flash flooding.
Showers and storms continue well into Tuesday with potential for another round of severe weather that bears watching Tuesday afternoon and early evening for eastern Nebraska and across Iowa.
Low level moisture pooling just ahead of the sfc low should bring 1000-2500 J/kg MLCAPE. Combined with strong deep layer shear (0-6km at 50+ kts), this suggests if initial surface based supercells can develop in northwest IA (vs further east), all severe hazards are possible.
WEDNESDAY THROUGH FRIDAY: Drier, cooler air moves in behind the strong departing system Tuesday night, but dry conditions are short lived. An active zonal flow weather pattern continues for the second half of the work week. We start off Wednesday morning with temperatures in the 40s to lower 50s. Another weak shortwave brings a low chance of showers Wednesday. By Thursday night, another potent longwave trough slides into the Rockies and drags a cold front through the Plains with potential for another round of showers and storms Thursday night through Friday.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
Issued at 1152 AM CDT Sun May 19 2024
Scattered showers continue to move through portions of the Tri- state area this morning, one area tied to a departing shortwave, and a second area developed on a low level jet. A few showers may continue to move eastward this afternoon as the jet veers in direction more to the southwest. For most, VFR conditions will continue with a gusty southeast wind up to 30 mph.
More uncertainty develops later this evening as a cluster of convection may slide eastward out of western South Dakota.
Additional scattered activity may form later this evening closer to the Tri-state area as the LLJ increases once again.
However, most guidance supports all of this activity moving east of I-29 by 6Z and out of the CWA by 06z. Behind this convection, a period of lower stratus may be possible into Monday morning.
FSD WATCHES/WARNINGS/ADVISORIES
SD...None.
MN...None.
IA...None.
NE...None.
| Airport | Dist | Age | Wind kt | Vis | Sky | Weather | Temp | DewPt | RH | inHg |
| KSUX SIOUX GATEWAY/BRIG GEN BUD DAY FIELD,IA | 2 sm | 43 min | SE 13G20 | 10 sm | Partly Cloudy | 57°F | 50°F | 77% | 29.95 |
Omaha, NE,
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