Alert archive / Idaho / Flash Flood Warnings in 2026
Flash Flood Warning 9, NWS Pocatello, ID
NWS Pocatello, ID issued this flash flood warning at Sep 17, 2026, 9:51 PM MDT for Madison County, Idaho. It was in force for 5 hr. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Sep 17, 2026, 9:51 PM MDT (03:51 UTC)
- Expired
- Sep 18, 2026, 2:45 AM MDT
- In force
- 5 hr
- Issued by
- NWS Pocatello, ID
- Area
- Storm-based polygon
- Flood severity
- None
County Madison County, ID
The radar
The Pocatello radar (KSFX), 109 km from the middle of the area, began a volume at 03:52 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 17, 11:00 PM MDT | FLASH FLOOD | 1 S Rexburg, ID | Multiple reports of road flooding near the roundabout in Rexburg. Report via Facebook. |
| Sep 17, 11:15 PM MDT | FLASH FLOOD | Rexburg, ID | Reports of multiple flooded basement apartments in Rexburg. Report via Facebook. |
| Sep 17, 11:53 PM MDT | RAIN 1.22 | 1 Nw Rexburg, ID | ASOS station KRXE Rexburg-Madison Airport. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 69 minutes after it went out.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Riverton, WY (KRIW), launched 00:00Z, 3.9 hours before the alert went out and 284 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 272 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 1762 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 17 m²/s²
- 0-3 km storm-relative helicity
- 104 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted.
462
WGUS55 KPIH 180351
FFWPIH
IDC065-180845-
/O.NEW.KPIH.FF.W.0009.260918T0351Z-260918T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
951 PM MDT Thu Sep 17 2026
The National Weather Service in Pocatello has issued a
* Flash Flood Warning for...
Central Madison County in southeastern Idaho...
* Until 245 AM MDT.
* At 951 PM MDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Rexburg.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4384 11181 4381 11181 4380 11180 4380 11175
4381 11175 4381 11173 4382 11173 4382 11172
4385 11172 4384 11173
FLASH FLOOD...RADAR INDICATED
$$
GK1 follow-up statement
759
WGUS75 KPIH 180849
FFSPIH
Flash Flood Statement
National Weather Service Pocatello ID
249 AM MDT Fri Sep 18 2026
IDC065-180859-
/O.EXP.KPIH.FF.W.0009.000000T0000Z-260918T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison ID-
249 AM MDT Fri Sep 18 2026
...FLASH FLOOD WARNING HAS EXPIRED FOR CENTRAL MADISON COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
&&
LAT...LON 4384 11181 4381 11181 4380 11180 4380 11175
4381 11175 4381 11173 4382 11173 4382 11172
4385 11172 4384 11173
$$
13What forecasters said that day
The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Pocatello, ID wrote its last area forecast discussion before this flash flood warning went out at Sep 17, 6:43 PM MDT, 3 hours 8 minutes earlier. Its key messages:
- Showers and thunderstorms continue through Saturday
- Hail and gusty winds are possible with storms through this evening, and locally heavy rainfall through Saturday
- Cooler temperatures are expected through Saturday before slowly warming up next week
Area forecast discussion, Sep 17, 6:43 PM MDT, 3 hours 8 minutes before
Area Forecast Discussion National Weather Service Pocatello ID 643 PM MDT Thu Sep 17 2026 .KEY MESSAGES... - Showers and thunderstorms continue through Saturday - Hail and gusty winds are possible with storms through this evening, and locally heavy rainfall through Saturday - Cooler temperatures are expected through Saturday before slowly warming up next week && .DISCUSSION... Issued at 1250 PM MDT Thu Sep 17 2026 Showers and thunderstorms have continued today as one of more waves spin north across Idaho ahead of the low centered over northern California. Showers and storms already this morning have produced moderate to heavy rainfall, as moisture continues to become deeper and more conducive for this to happen. For the rest of today and into this evening, more showers and storms will develop...especially where the dry slot behind this morning's precipitation has allowed for more sunshine to interact with the humid airmass in place. Heavy rainfall at times is possible and will be the main impact. Some stronger storms will produce hail and gusty winds over 40 mph. The latter is already evident due to outflow from storms over the eastern/southeast highlands, creating a slow moving outflow boundary across the Snake Plain and into portions of the Magic Valley. It is likely this boundary will become an additional focus for storm development, in addition to anything from pure heating. There is a MARGINAL RISK for severe storms across the area, and certainly is possible with the conditions setting up. The overall pattern remains unchanged through Saturday, as the cutoff low over California is finally picked back up by the steering flow across the rest of the western U.S. The low will still be a slow mover, and finally shifts over the state on Saturday. Until that low passes, expect multiple rounds of showers and storms producing heavy rainfall at times. A combination of much higher moisture content and more widespread showers and storms tomorrow into Saturday, the potential for higher rainfall amounts has jumped up quite a bit. Will everyone see the heaviest rainfall in the forecast? No, but the potential is there and higher than the past day or so. From the Wood River Valley south across the Magic Valley and into the South Hills/Albion Mountains, potential rainfall amounts through Saturday afternoon are the "lowest" and up to 0.35 is possible. Elsewhere, the potential is there from 0.50-1.0" with locally higher amounts. The current storm total forecast is likely showing the higher end of the forecast ranges, as likely not every square mile shown in the gridded forecast is going to see those amounts. We considered Flash Flood Watches especially in areas with burn scars, but for now are opting to handle it on a case-by-case basis in terms of any needed warnings. Wraparound showers and storms are possible Sunday. Heading into next week, there is a struggle on what happens with the next low moving into the western U.S. Before it appeared the low would stay the south and we would remain dry. There is some indication it may now drift far enough north to bring some clouds and potentially more showers and storms. That seems to be handled by the Blend of Models which does have isolated coverage daily across portions of central and eastern Idaho. Temperatures will struggle to hit the 70s tomorrow and Saturday, before warming back up early next week. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 637 PM MDT Thu Sep 17 2026 Expect periods of showers and thunderstorms through Friday afternoon. Went with prob 30 thunderstorms at all sites after 18Z Friday with -SHRA as well after 12Z or 18Z. Thunderstorms at IDA and PIH should end after 02Z this evening. && .FIRE WEATHER... Issued at 1250 PM MDT Thu Sep 17 2026 A low pressure system moving through the region will produce intermittent showers and thunderstorms over the next 36-48 hours. Ample wetting rainfall is expected especially across the central mountains and eastern highlands, with lower totals in the Magic Valley and south Hills areas. This system will depart over the weekend allowing for drier weather to setup by the second half of the weekend and into much of next week. && .PIH WATCHES/WARNINGS/ADVISORIES... && DISCUSSION...Keyes AVIATION...GK FIRE WEATHER...McKaughan
In the hours before
Special weather statement, Sep 17, 6:14 PM MDT, 3 hours 37 minutes before
Special Weather Statement
National Weather Service Pocatello ID
614 PM MDT Thu Sep 17 2026
IDZ054-058-180045-
Marsh and Arbon Highlands ID-Lower Snake River Plain ID-
614 PM MDT Thu Sep 17 2026
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL BANNOCK AND SOUTH
CENTRAL BINGHAM COUNTIES THROUGH 645 PM MDT...
At 614 PM MDT, Doppler radar was tracking a strong thunderstorm over
Fort Hall Buffalo Lodge, or 10 miles north of Pocatello, moving
northeast at 15 to 20 mph.
HAZARD...Wind gusts in excess of 35 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to outdoor objects is
possible.
Locations impacted include...
Blackfoot, Chubbuck, Fort Hall Buffalo Lodge, Fort Hall Eagle Lodge,
and Fort Hall Townsite.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4290 11251 4303 11255 4320 11235 4307 11223
TIME...MOT...LOC 0014Z 228DEG 19KT 4302 11247
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...35 MPH
TWLocal storm report, Sep 17, 6:17 PM MDT, 3 hours 34 minutes before
Preliminary Local Storm Report
National Weather Service Pocatello ID
617 PM MDT Thu Sep 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0545 PM Hail 1 SSE Pocatello Airport 42.90N 112.59W
09/17/2026 M0.75 Inch Power ID Official NWS Obs
&&Special weather statement, Sep 17, 7:52 PM MDT, 1 hour 59 minutes before
Special Weather Statement
National Weather Service Pocatello ID
752 PM MDT Thu Sep 17 2026
IDZ052-053-067-180245-
Arco/Mud Lake Desert ID-Upper Snake River Plain ID-
Beaverhead/Lemhi Highlands ID-
752 PM MDT Thu Sep 17 2026
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN FREMONT...CENTRAL
JEFFERSON...NORTHERN BONNEVILLE...NORTHWESTERN MADISON AND EAST
CENTRAL CLARK COUNTIES THROUGH 845 PM MDT...
At 751 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Roberts, or 13 miles northwest of Idaho Falls,
moving snortheast at 25 mph.
HAZARD...Wind gusts in excess of 45 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to outdoor objects is
possible.
Locations impacted include...
Rexburg, Sugar City, Menan, Roberts, Lewisville, Parker, Egin, Plano,
St Anthony, Osgood, Saint Anthony Sand Dunes, and Sage Junction.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 4417 11193 4401 11160 4349 11216 4362 11240
TIME...MOT...LOC 0151Z 027DEG 22KT 4364 11222
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...45 MPH
GKSpecial weather statement, Sep 17, 8:25 PM MDT, 1 hour 26 minutes before
Special Weather Statement
National Weather Service Pocatello ID
825 PM MDT Thu Sep 17 2026
IDZ052>054-180315-
Arco/Mud Lake Desert ID-Upper Snake River Plain ID-
Lower Snake River Plain ID-
825 PM MDT Thu Sep 17 2026
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN JEFFERSON...
NORTHWESTERN BANNOCK...WESTERN BONNEVILLE AND WESTERN BINGHAM
COUNTIES THROUGH 915 PM MDT...
At 824 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles southwest of Taber, or 19 miles west of Blackfoot, moving
northeast at 25 mph.
HAZARD...Wind gusts in excess of 35 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to outdoor objects is
possible.
Locations impacted include...
Blackfoot, eastern American Falls Reservoir, Firth, Rose, Fort Hall
Eagle Lodge, Taber, Springfield, Rockford, Moreland, Pingree,
Groveland, Basalt, Sterling, East Butte, and Wapello.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 4365 11258 4329 11209 4293 11272 4323 11289
TIME...MOT...LOC 0224Z 197DEG 22KT 4322 11272
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...35 MPH
GKLocal storm report, Sep 17, 9:18 PM MDT, 33 minutes before
Preliminary Local Storm Report
National Weather Service Pocatello ID
918 PM MDT Thu Sep 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 PM Hail 1 E Blackfoot 43.19N 112.33W
09/17/2026 E1.50 Inch Bingham ID Public
&&Local storm report, Sep 17, 9:38 PM MDT, 13 minutes before
Preliminary Local Storm Report
National Weather Service Pocatello ID
938 PM MDT Thu Sep 17 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0935 PM Hail Firth 43.31N 112.18W
09/17/2026 E1.00 Inch Bingham ID Public
&&The office that day
Everything else NWS Pocatello, ID issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 17, 6:14 PM MDT | Special Weather Statement | PIH | Bingham | 31 min |
| Sep 17, 7:32 PM MDT | Severe Thunderstorm Warning | PIH | Bear Lake | 29 min |
| Sep 17, 7:52 PM MDT | Special Weather Statement | PIH | Jefferson | 53 min |
| Sep 17, 8:25 PM MDT | Special Weather Statement | PIH | Bingham | 50 min |
| Sep 17, 9:08 PM MDT | Severe Thunderstorm Warning | PIH | Bingham, Bonneville | 52 min |
| Sep 17, 9:32 PM MDT | Severe Thunderstorm Warning | PIH | Bingham | 43 min |
| Sep 17, 10:00 PM MDT | Flash Flood Warning | PIH | Bonneville, Jefferson | 4 hr |
| Sep 17, 10:05 PM MDT | Severe Thunderstorm Warning | PIH | Bannock, Bingham, Oneida, Power | 29 min |
| Sep 17, 10:11 PM MDT | Severe Thunderstorm Warning | PIH | Bingham, Bonneville, Jefferson | 36 min |
| Sep 17, 10:25 PM MDT | Flash Flood Warning | PIH | Jefferson, Madison | 4 hr |
| Sep 17, 10:37 PM MDT | Severe Thunderstorm Warning | PIH | Bannock, Bingham, Caribou, Power | 38 min |
| Sep 17, 11:24 PM MDT | Special Weather Statement | PIH | Bonneville, Teton | 66 min |
| Sep 17, 11:26 PM MDT | Special Weather Statement | PIH | Bonneville | 49 min |
| Sep 18, 12:17 AM MDT | Special Weather Statement | PIH | Bonneville, Madison, Teton | 43 min |
| Sep 18, 12:21 AM MDT | Special Weather Statement | PIH | Bingham | 39 min |
| Sep 18, 2:52 AM MDT | Flash Flood Watch | PIH | Bonneville, Fremont, Jefferson, Madison | 8 hr |
| Sep 18, 8:28 AM MDT | Special Weather Statement | PIH | Bannock, Bear Lake, Caribou | 32 min |
| Sep 18, 9:08 AM MDT | Flash Flood Warning | PIH | Blaine | 5 hr |
| Sep 18, 10:30 AM MDT | Flood Watch | PIH | Bannock, Bear Lake, Bingham, Blaine, Bonneville, Butte and 10 more | 8 hr |
| Sep 18, 10:44 AM MDT | Flash Flood Warning | PIH | Jefferson, Madison | 89 min |
| Sep 18, 1:37 PM MDT | Flash Flood Warning | PIH | Blaine, Butte, Custer | 3 hr |
Nearby
Flash Flood Warnings in Idaho, 2026Every flash flood warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.