Weather Alert Day: Heavy rain continues Monday morning, severe threat remains possible Monday afternoon

RAINFALL UPDATE:

Thunderstorms Sunday night and Monday morning have left streaks of extensive rain in relatively short periods of time. 24 hour rainfall totals are nearing 2 inches in isolated locations. Some places have even been subject to flash flood warnings in the last 24 hours. More rain is expected through midday, but also again tonight as more storms are expected.

Monday is an ABC17 Stormtrack Weather Alert Day, as severe thunderstorms continue early Monday morning, and are expected again from midday through the afternoon.

SETUP:

MONDAY AM

Strong low pressure across the Plains has sent a warm front to our region, opening up the area to warm, moist air from the Gulf with dew points rising into the 60s. Severe storms are possible along and south of the warm front. Overnight, there has been severe weather with several Severe Thunderstorm and Tornado warnings being issued by the National Weather Service. Severe storms worked from Kansas into mid-Missouri this morning, bringing damage to the region with additional alerts. After weakening, this cluster of storms is forecast to dry up this afternoon.

MONDAY PM

Areas south of the warm front, where we don't get storms through the morning, see moisture and instability bolstered, along with supportive amounts of wind shear. Where we can get lift ahead of the cold front working in later in the evening, supercellular storms could form quickly. Otherwise, strong storms are still likely to form along the cold front. In either scenario, severe weather is a concern.

TIMING

Two rounds are anticipated; one in the morning from 6 a.m. to around noon, and another in the afternoon until around 7 p.m.

Instability will be maximized over our area early in the day, with higher values if clouds and rain from Monday morning's round can clear quickly. There are some questions around the ability to destabilize on Monday. If rain and clouds from the Sunday night/Monday morning round dwell too long, the rain and storms along the cold front may struggle to develop much intensity. This will likely be localized, and not area-wide, so severe weather is likely at least in some locations. Instability wanes from west to east as a cold front sweeps through the area by evening, decreasing chances of storms sometime near to just after dinner time on Monday.

IMPACTS

Severe impacts may include wind, hail, and tornadoes, but concern for strong tornadoes is rising, particularly in eastern portions of mid-Missouri, on Monday afternoon. Still, there is a conditionality to all of this. If clouds and rain linger this morning, our severe threats will be on the lower end of the spectrum, but if some areas can clear out, we'll have potential for very strong thunderstorms capable of all hazards, including strong tornadoes.

The Storm Prediction Center has Mid-Missouri in a level 3/5 risk for severe storms on Monday. All hazards are possible where storms develop. Notably, SPC expanded the tornado risk to more of Mid-Missouri with its 1:00 a.m. update, bringing the zone of a reasonable maximum strength of EF-3 to areas along and east of Highway 63, and up to EF-2 along a line from Boonville to Camdenton and east. We believe this is reasonable as the potential for supercellular storms would provide a better environment for these stronger types of tornadoes. When the cold front comes through, tornadoes will still be possible as storms congeal into a line, but storm interactions will limit the tornado threat in comparison to the earlier afternoon threat of individual cells.

Along with the threat of severe weather, rounds of heavy rain overnight into Monday morning have prompted a Flood Watch for western portions of the state, where 1-3" of rain has already fallen, with another 1-2" possible by Monday afternoon. Slow-moving storms caused flash flooding on Sunday night, prompting water rescues in southwest Missouri.

Make sure to stay with the ABC 17 Stormtrack Weather Team over the weekend as we pinpoint the exact timing and hazards. We'll be sure to update this blog frequently, so set your ABC 17 Stormtrack Weather app to receive alerts from the team as we forecast this next severe weather event.