Tornado watch shifts toward Eastern Iowa

The tornado watch has been expanded to include eastern Iowa overnight.

Areas east of I-35 and south of Hwy. 20 will be part of the watch until 4 a.m. Saturday.

Areas to the west like Carroll, Audubon, and Harlan are no longer in the watch.

So far, thunderstorms have mostly been non-severe and scattered, but the atmosphere still has lots of wind shear as the night continues.

There’s a low chance that more storms moving into eastern Iowa from the west and south could become tornadic overnight.

Severe thunderstorm warning expires for Polk, Boone, Dallas counties

The National Weather Service in Des Moines issued a severe thunderstorm warning at around 7:24 p.m. for parts of Polk, Boone and Dallas counties in central Iowa.

The warning includes winds of up to 50 mph and half-dollar-sized hail. Dallas Center, Grimes, Granger and Madrid are included in the warning.

The warning was set to expire at 8:15 p.m. but it was canceled at 7:52 after the storm weakened below severe limits.

Southwest Iowa thunderstorm warning canceled

A severe thunderstorm warning was issued for parts of southwest Iowa, including Cass County, through 7 p.m. Hail and strong winds have been reported.

The warning was canceled at 6:44 p.m., according to the National Weather Service.

Tornado watch issued

A tornado watch is out for much of central and southwest Iowa until 10 p.m. Friday.

This watch extends from Highway 20 in north-central Iowa all the way down to central Kansas.

A few tornadoes are possible in this watch area this evening, along with scattered large hail and damaging wind gusts up to 70 mph.

Storms are expected to fire down in Kansas and northwest Missouri, then spread northeast into Iowa this evening before a cold front sweeps through the state tonight.

Here’s how to make sure your phone provides severe weather alerts

When storms are in the forecast, you want to make sure your mobile phone settings allow for alerts that warn you of severe weather.

The U.S. Homeland Security Department says to check your phone’s settings and ensure you have «Government Alerts» or «Emergency Alert Messages» enabled.

You can keep track of the weather wherever you are with the KCCI app: Apple | Google Play

We’ll send you weather alerts and you can track live radar right on your phone.

Weather Aware: How to make sure your phone provides severe weather alerts

Share videos, photos of storm with KCCI

If you capture videos or photos of Friday’s storms, please consider sharing them with us through this link.

Tornado safety tips

If you are in a home, small building, nursing home, hospital, factory, shopping center or high-rise building:

• Go to a pre-designated area such as a safe room, basement, storm cellar or the lowest building level. If there is no basement, go to the center of a small interior room on the lowest level (closet, interior hallway) away from corners, windows, doors and outside walls. Put as many walls as possible between you and the outside. Get under a sturdy table and use your arms to protect your head and neck.
• If you are in a pickup line at your child’s school, get inside the building as quickly as possible.
• In a high-rise building, go to a small interior room or hallway on the lowest floor possible.
• Make sure you are wearing sturdy shoes.
• Do not open windows.

If you are in a mobile home, manufactured office building or camper:

• Get out immediately and go to a pre-identified location such as the lowest floor of a sturdy nearby building or a storm shelter. Mobile homes, even if tied down, offer little protection from tornadoes.

If you are not in a sturdy building, there is no single research-based recommendation for what last-resort action to take because many factors can affect your decision.

Possible actions (which do not guarantee safety) include:

• Immediately get into a vehicle, buckle your seat belt and try to drive to the closest sturdy shelter. If your vehicle is hit by flying debris while you are driving, pull over and park.
• Take cover in a stationary vehicle. Put the seat belt on and cover your head with your arms and a blanket, coat or cushion if possible.
• Lie in an area noticeably lower than the level of the road and cover your head with your arms and a blanket, coat or cushion if possible.

Understanding the Enhanced Fujita Scale

The National Weather Service uses the Enhanced Fujita Scale, or EF-Scale, to assign tornado ratings based on estimated wind speeds and related damage.

The Enhanced Fujita Scale, which replaced the earlier Fujita Scale in February 2007, categorizes tornadoes by degree of damage indicators and associates that damage with estimated wind speeds for three-second gusts.

Enhanced Fujita Scale levels

• EF0 (weak): 65-85 mph wind gusts
• EF1 (weak): 86-110 mph wind gusts
• EF2 (strong): 111-135 mph wind gusts
• EF3 (strong): 136-165 mph wind gusts
• EF4 (violent): 166-200 mph wind gusts
• EF5 (violent): Over 200 mph wind gusts

Illustrating hail size references

Traditionally, common objects like peas and golf balls and softballs have been used to describe the hail you may see. This image helps with those references.

The season’s first round of widespread thunderstorms moved in overnight, making for a rainy Friday morning. Drying out this afternoon with a potentially stronger round of thunderstorms expected by this evening.

Here’s what we know:

• A break in the storms this afternoon as temperatures and humidity levels climb
• Strong to severe storms expected to develop by the late afternoon and evening
• Most of Iowa has at least some chance of strong to severe storms

Afternoon clearing ahead of more storms

Today’s first round of storms moved in shortly after Midnight, lasting through mid-morning. Heavy downpours brought some impressive rain totals on the order of 1 to 2 inches. Des Moines set a new record for the day coming in at 1.41″ so far, breaking the cold record of 0.95″ of rain set in 1983.

The final lingering showers wrapped up around Noon with some clearing happening across southern and southwest Iowa helping temperatures to warm into the 60s and 70s. Clouds will fill back in at times through the afternoon, but temperatures will continue to warm with highs in the metro around 70 degrees, and mid-70s across southwest Iowa.

The warm, humid, and breezy conditions this afternoon will provide plenty of energy for storms to develop by late this afternoon and evening.

By late afternoon a cold front moving from west to east will kick off additional scattered storms. With the warmth and humidity available, stronger storms will be possible. How strong the storms get will depend on how much sunshine we see, and just how high temperatures climb. Highs in the 70s will mean stronger storms, while highs closer to 65 will slightly lower severe risks. The warmer conditions moving into southwest Iowa with highs in the 70s and higher humidity has increased the severe risk slightly for areas to the west and southwest of the Des Moines metro.

Main threats Friday: Large hail and strong wind gusts up to 70 mph

Most of the state currently has a slight risk for severe weather, or a level 2 out of 5. The southwest corner of Iowa has been upgraded to an enhanced risk, or a level 3 out of 5. This is the area that will have a slightly higher risk for large hail up to 2 inches in size and damaging winds to around 70mph. While the tornado risk is limited, it cannot be ruled out today, especially across southern and southwest Iowa where it will be slightly warmer this afternoon. If we do see more breaks in the clouds and temperatures do warm into the 70s that would increase the tornado threat and intensity as well. Storms will move quickly, possibly around 50mph. That will take them from southwest Iowa around 4pm, to the metro by around 6pm. The storms should generally be exiting the area by 10pm, if not sooner. The severe risk will decrease slowly as the storms move from west to east across the state.

There are still some question marks for the afternoon storms. While there was some brief clearing, clouds moving back in across southern Iowa may help to keep temperatures a little lower. If that happens, the severe risk will be dampened slightly. Additionally, if the storms arrive later than expected, temperatures will be cooling in the evening hours and that would also lower the severe risk. Stay tuned for updates over the next couple days as the details on the timing and risk levels are adjusted.

Potential rainfall totals

Rainfall totals of 1 to 2 inches were common this morning. With multiple rounds of storms expected, totals throughout the day could approach 2 to 4 inches, with isolated higher totals. While isolated flooding can’t be ruled out, the generally dry conditions so far this year and the relatively fast movement of the storms should keep the risk for widespread flash flood low. However, quick ponding and flowing water on roads and highways is possible.