ARKANSAS, USA — Enjoy Tuesday and Wednesday because the weather is expected to turn ugly by the end of the workweek.
A system developing into Texas will swing through or just to the northwest of central AR. This is a potent storm and will pull in a lot of moisture from the Gulf of Mexico which means the potential of heavy rain is on the table.
Another concern is the threat of severe weather, which does include the possibility of tornadoes due to key ingredients that look to be in place for this event.
Who is under the risk?
Here is my current thinking at this time on Tuesday afternoon. Most of state is under the risk of seeing severe weather for Friday evening into Saturday morning at this time. The higher threat appears to be for south and SW AR. This is where more ingredients are most likely to be in place for storms to become severe.
Here is what you need to know:
Thursday– Showers and storms will develop from west to east through the day. One or two storms could be strong producing gusty winds.
Friday-Scattered showers and storms through the day. By the evening the storms will become stronger. Strong to possible severe storms will continue through the night. A line of storms is expected to march across the region Friday night as a cold front pushes east. Along this line heavy rain producing several inches, damaging wind gusts and quick spin-up tornadoes are also possible.
Saturday-Severe weather moves into Mississippi and Tennessee by mid-morning if not sooner. Turning colder with temperatures dropping through the day from the 50s into 40s. The mercury will plunge into the 30s for north AR. Rain could end as a wintry mix to snow in NW AR. A light accumulation of up to 1” looks possible at this time.
SEVERE WEATHER THREAT BREAKDOWN:
Friday evening through the night is when you need to be weather aware, have a way of getting any watches or warnings that may be issued. And especially since this event is expected to occur at night have an alarm to wake you up if a tornado warning is issued.
A line of storms looks possible to move across the area Friday evening into the night. However, if any cells develop ahead of the main line these storms could be supercells and have a higher potential of producing tornadoes.
A TORNADO WATCH is issued when conditions are favorable for any storms that develop in and near the included counties could turn severe and produce damaging winds, large hail or a tornado. When a watch is issued stay tuned to THV11 for the latest and be prepared to rapidly changing conditions.
A TORNADO WARNING is issued when meteorologists with the National Weather Service see rotation on doppler radar developing in a storm that could produce a tornado at any time. A tornado has been spotted by reputable sources. Or a tornado is confirmed by debris being lofted into the air by the twister on doppler radar. At this time you need to take action and go to the safest place available quickly.
The Weather Set-up
The risk of severe weather is in play because the recipe for severe weather is expected to come together.
For severe storms to develop the atmosphere needs to have moisture, heat, something to lift the air, storm fuel and higher winds above the surface.
Looking at the amount of moisture that is expected, we have plenty. Dew points need to be at least 55° Once you get into the 60s that environment is ripe for storms and heavy rain.
Temperatures are expected to be well into the 60s and maybe 70s due to the path of the low pressure system and the warm front pushing north.
The cold front and rising air ahead of the system is all the lifting in place.
Storm fuel should not be an issue, the more fuel for the storms to feed off of the taller and stronger the storms can develop. Latest information has a good amount of storm fuel in place.
The key ingredient for the chance of severe weather is the placement of the low level Jetstream or the river of fast moving air at 5000 feet above the surface. The forecast shows winds of 60 to 80 mph over central AR at this level. This wind energy could be brought down to the surface by storms.
Also winds changing direction and speed as you go up in the atmosphere produces “SHEAR”. When shear is in place storms could rotate and produce tornadoes.
HEAVY RAIN POSSIBLE FLASH FLOODING:
Several inches of rain are possible depending on the track of the storm. Right now it looks like the target area of 3 to 5” of rain will be for northern parts of viewing area including the Little Rock metro.
The heaviest rain is expected to fall Friday evening into Saturday morning. Flash flooding will be possible for small creeks and streams, low lying areas and poor drainage locations.
FINAL THOUGHTS: This system is still a few days away and any changes in the expected track will change the risk of severe weather and where the heaviest swath of rain will fall.
Stay tuned to THV11 through the rest of the week for the latest updates.