Weather Blog: Widespread Flash Flooding Event Likely Wednesday into Thursday as well as a Severe Threat

Weather Blog

Here is the latest on the flash flooding and severe threat across the region!

Current Situation

Strong Upper Level Storm System.

A massive storm system currently situated over the southwest will slowly eject eastward. As it does so, several waves of lift will move along a stalled out frontal boundary at the surface. These waves will bring several rounds of rain throughout the day on our Wednesday through the overnight hours and into our Thursday morning. The system finally gets kicked out of here by Thursday evening.

This is a classic flash flooding set-up. A slow moving positively-tilted upper level trough creates a stalled out frontal boundary at the surface leading to the training of thunderstorms. These storms will be VERY efficient rain producers with a tropical atmosphere in place over our area. 1 to possibly 2 inches per hour rainfall rates are possible in the heaviest of the downpours.

Areal Flash Flood Watch in Effect Thru Thursday 7 AM for Most of Our Viewing Area..

Due to this set-up, the National Weather Service offices have issued both flash flood and area flood watches for our viewing area. An areal flood watch means that conditions are ripe for small creeks/streams, main stem rivers and low lying areas to flood. Stay weather aware, and NEVER drive into a flooded road. “TURN AROUND, DON’T DROWN!”

Severe Threat

As far as the severe threat is concerned. We could see some large hail from elevated storms early Wednesday morning. The Storm Prediction Center has us briefly clipped by a level 2/5 for the overnight tonight into early (before 7 AM) Wednesday morning.

SPC Outlook Day 1. Valid Tuesday 7 AM Thru Wednesday 7 AM.
SPC Severe Threats Day 1. Valid Tuesday After 7 AM Thru Wednesday 7 AM.

If we see breaks in the storms and rain in the afternoon, storms could reorganize with all threats including tornadoes are on the table. The Storm Prediction Center has us at a level 1/5 (marginal risk) for severe weather during the day on Wednesday.

SPC Outlook Day 2. Valid Wednesday After 7 AM Thru Thursday 7 AM.
SPC Severe Threats Day 2. Valid Wednesday After 7 AM Thru Thursday 7 AM.

Flash Flooding Threat

Widespread Rainfall Amounts of 2-4″, Localized Higher Amounts Possible.

For 7 day rainfall totals, we are looking at a widespread 2-4″ with some amounts locally over 4 inches! These high rain totals will likely causes issues for low lying areas and areas near creeks or streams.

Change in HRRR Rainfall Bullseye from the 18Z to the 0Z Run. Zoomed in NW Arkansas View.
Change in HRRR Rain Bullseye from the 18Z to the 0Z Run. Coverage Area View.
Most Models Are Showing Widespread 2-4″ from This Event.

One of our high resolution models is indicating that we could see bullseyes of well over 4″ in some places across NW Arkansas. DO NOT take these numbers as the totals exactly, but it gives you an idea that we could see quite a bit of rainfall across our northwestern counties. Keep in mind, this bullseye of the heaviest rain could shift north or south, so stay tuned to later forecasts.

Timing

Here is the latest timing of this flash flood threat and severe threat.

HRRR Future Track Model. Valid 5:30 PM Tuesday Thru 1:30 PM on Thursday.

Scattered storms develop overnight and move into the area early on our Wednesday morning. Then rainfall becomes widespread as we head through the day on Wednesday. Severe weather could be possible if the River Valley warms and instability increases as we go into the late afternoon.

Rain will continue heavy at times overnight Wednesday night into Thursday morning, eventually shifting south of the area by Thursday evening.

To Learn More About the Dangers of Flooding Check Out These Digital Extras

Find out if you live in a flood prone area using this ArcGIS Map application from FEMA. Just type in your address and drop a pin. Click HERE to begin!

Keep it here with Your Weather Authority Team for the latest on this massive rain event!

Download Our Free NWA Weather Authority App From the Google Play and Apple App Store!

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