FirstWarn Weather

FIRST WARN FORECAST
Friday, September 25, 2026
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KEY MESSAGES
- Cloudy, cool conditions will dominate much of the region through the weekend.
- Scattered showers are possible today, especially across northern Missouri and west-central Illinois.
- The best chance for rain, 60–80%, arrives early Saturday morning, particularly across northeast Missouri and west-central Illinois.
- Areas that receive rain Saturday may struggle to reach 70°.
- Confidence continues to increase for a more widespread, beneficial rainfall Tuesday into Wednesday of next week.
CLOUDS, COOLER TEMPERATURES & SOME RAIN
It certainly feels more like late September across the region this morning. A large area of high pressure over eastern Canada continues to push cooler and drier air southwestward into Missouri and Illinois. At the same time, moisture moving around an upper-level ridge is producing areas of showers across portions of the Midwest.
For today, clouds will remain stubborn across much of the region. A few showers will be possible, mainly across northeast and central Missouri into west-central Illinois, but rainfall should generally remain light. Dry air closer to the surface will make it difficult for some of that rain to even reach the ground.
Temperatures will depend heavily on cloud cover. Areas that remain cloudy or see occasional rain may struggle to reach 70° this afternoon. Where we manage to get some breaks in the clouds, temperatures should climb into the middle and upper 70s. Far southeast Missouri will be the warm spot, with a few locations potentially approaching 80°.
BETTER RAIN CHANCES SATURDAY
Rain chances increase early Saturday morning as deeper moisture pushes farther south into the region. Scattered showers will become more numerous across central and northeast Missouri and west-central Illinois, where rain chances increase to around 60–80%. There may even be enough instability for an isolated rumble of thunder, but widespread thunderstorms or severe weather are not expected.
Once again, rainfall will have a significant impact on temperatures. Much of central Missouri, areas north of I-70 and portions of west-central Illinois could remain in the upper 60s to around 70° Saturday. Farther south, where rain will be less widespread, highs should reach the lower to middle 70s.
Some lingering showers remain possible Saturday night into Sunday morning, with rain chances generally around 20–40%. Otherwise, Sunday continues the cloudy and seasonably cool theme before we begin watching our next weather maker.
BENEFICIAL RAIN SIGNAL GROWING FOR NEXT WEEK
The more interesting part of the forecast arrives toward the middle of next week. A large upper-level trough will move across the western United States and eventually send increasing moisture toward Missouri and Illinois. There are still questions concerning the exact timing and evolution of this system, so we're not ready to pin down exact rainfall totals just yet.
What is becoming increasingly encouraging is the agreement among the ensemble guidance. Probabilities for measurable rainfall Tuesday into Wednesday reach around 90% in portions of the region. That does not mean everyone has a 90% chance of receiving significant rainfall, but it does indicate growing confidence that a widespread rain event may develop somewhere across our region.
Given the recent need for rainfall, this is a system we'll be watching closely. The potential is increasing for a beneficial soaking rain during the middle of next week, but we'll need another couple of forecast cycles before getting more specific about amounts and exactly where the heaviest rain will fall.
Temperatures next week should remain fairly steady for late September, generally ranging from the lower 70s north to near 80° south. For now, keep the umbrella nearby this weekend and enjoy the cooler temperatures. Fall has definitely decided to make its presence known.

First Warn Weather
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FIRST WARN FORECAST

Thursday, September 24, 2026

HEADLINES

Cloudy & Cool: Plenty of clouds will keep temperatures seasonably cool today and Friday.

Upper 60s to Mid 70s: The coolest temperatures will be found where clouds remain thickest.

Weekend Rain Chances: Showers return Friday night into Saturday, especially across central and northern Missouri.

Gradual Weekend Warm-Up: Southerly winds return with temperatures potentially climbing back into the 70s and possibly lower 80s.

Better Rain Opportunity Next Week: A stronger system could bring widespread rain Tuesday into Wednesday, with some areas potentially receiving 0.50 inch or more.

Clouds remain the big weather story across much of Missouri and Illinois this morning. Persistent northeast winds continue to pull cooler air into the region while plenty of low-level moisture remains trapped beneath the atmosphere. The result is another day with widespread low clouds, especially across northern and eastern Missouri into western Illinois.

Those clouds will have a major influence on temperatures this afternoon. Areas that remain socked in should struggle to get much beyond the upper 60s and lower 70s. Where the clouds thin enough to allow a little sunshine, temperatures could reach the mid 70s. Overall, it will be another seasonably cool late-September day.

Friday remains somewhat tricky. Clouds should once again be around, but there are indications they may begin breaking apart a little sooner as the upper-level weather pattern changes. If we manage several hours of sunshine, temperatures could respond quickly and climb into the mid to upper 70s. If the clouds stubbornly hang around, Friday may end up looking and feeling quite similar to today.

CHANGES THIS WEEKEND

Our weather pattern begins shifting Friday night into the weekend as the persistent northeast flow finally relaxes and winds gradually turn more southerly. That should allow temperatures to moderate, but it will also bring moisture back into the region.

A disturbance moving out of the Plains will bring our next opportunity for showers from Friday night into Saturday. The best rain chances currently favor central and northeastern Missouri. While measurable rainfall is increasingly likely in those areas, this does not appear to be a particularly heavy rainmaker. Many locations that receive rain will likely see relatively modest totals.

Outside of the showers, temperatures should gradually warm this weekend into early next week. There is still quite a bit of uncertainty regarding exactly how warm we become. Depending on cloud cover and rainfall, afternoon temperatures could remain in the mid and upper 70s, while locations seeing more sunshine could make a run toward the lower to perhaps middle 80s.

WATCHING A STRONGER SYSTEM NEXT WEEK

Our attention then turns toward Tuesday and Wednesday, when a stronger disturbance and associated cold front may move through the central United States. The exact timing remains uncertain this far out, but this system currently represents our best opportunity for widespread rainfall during the next seven days.

Current guidance supports a 70–90% chance of measurable rainfall across much of the region, with roughly a 50–60% chance of rainfall totals reaching or exceeding 0.50 inch. Those numbers will continue to change as the timing and track of the system become clearer.

The front could also deliver another noticeable temperature change. Depending on exactly when it arrives, we could spend part of next week in the 70s before temperatures fall back into the 60s and lower 70s behind the front.

For now, enjoy the cooler weather. We have clouds today and Friday, a gradual warm-up this weekend, a few weekend showers, and potentially a much better opportunity for meaningful rainfall by the middle of next week.

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First Warn Weather

FirstWARN Alert: Flood Warning for Pike County in MO. From Meteorologist Nick Palisch

Fall arrives officially at 7:05 this evening.

FIRST WARN FORECAST

Monday, September 21, 2026

HEADLINES
The Heat Wave Is Over: The cold front has finally swept through most of the region, bringing a dramatic change in temperatures.
Morning Rain Moves Out: Scattered showers and thunderstorms will gradually end later this morning, although a few showers could linger.
60s & 70s Today: Most of us will be dramatically cooler than last week, with southeast Missouri the warm spot.
Cool Nights Ahead: Lows fall into the 50s this week, with some northern locations possibly dipping into the upper 40s Tuesday night.
A Taste of Fall: Seasonably cool and much less humid weather settles in for the remainder of the week.
No Heat Comeback: Temperatures gradually warm through the 70s and potentially reach the lower 80s next weekend, but another surge of significant heat and humidity is not showing up.
FIRST WARN FORECAST

Well, we made it.

After what seemed like an endless stretch of September heat, humidity and afternoon heat index values around 100°, the atmosphere has finally flipped the switch. The cold front we have been tracking for several days has pushed through most of the First Warn Weather coverage area, and if you step outside today, you are going to notice the difference immediately.

The front has already cleared much of Missouri and Illinois early this morning and is continuing south through southeast Missouri. Scattered showers and thunderstorms remain behind the front, but the majority of this activity will continue moving east and gradually come to an end later this morning. A few leftover showers could linger into the day, and southeast Missouri could see another shower or thunderstorm develop this afternoon as the remaining boundary works south.

I'm not concerned about severe weather today. While there is still some instability available across southeast Missouri, wind shear is very weak and cooler air is continuing to filter into the region behind the front. Any thunderstorms that manage to develop should remain relatively disorganized and below severe limits.

The bigger story is something we haven't been able to say much lately: it is going to feel comfortable outside.

Temperatures today will be dramatically different from what we experienced last week. Instead of widespread middle and upper 90s with heat index values over 100°, most locations will spend Monday in the 60s and 70s. Southeast Missouri will be the exception, where more sunshine and the later arrival of cooler air could allow temperatures to reach the lower 80s.

Cloud cover will play a major role in just how cool we remain today. Across much of the region, widespread low clouds combined with northerly winds will make it difficult for temperatures to climb very much from where they started this morning. Some locations may only warm about five degrees from their overnight lows. After the furnace we lived through last week, that is quite the turnaround.

Tuesday brings the cooler air to everyone. Southeast Missouri joins the rest of us with highs generally in the middle 70s, while much of the region enjoys another comfortable September afternoon. Humidity will be noticeably lower as well, so this isn't simply a break from the extreme temperatures. It is a genuine change in the air mass.

And wait until Tuesday night.

Temperatures will fall into the lower and middle 50s across much of the region, and there is even a 30-50% chance that portions of northern Missouri and Illinois dip into the upper 40s. Considering we were talking about heat index values over 100° just a few days ago, opening the windows and waking up to temperatures in the 50s will feel pretty remarkable.

The cooler pattern isn't going anywhere quickly, either. A strong area of high pressure settling across the Great Lakes and southeastern Canada will help maintain northerly surface winds across our region. Meanwhile, northwesterly flow higher in the atmosphere will prevent another surge of hot, humid air from immediately returning.

Temperatures will gradually moderate as we move through the week, which is exactly what we would expect this time of year. Highs should work their way through the 70s, eventually approaching the lower 80s by next weekend. That's not another heat wave. That's simply late September being late September.

The same weather pattern responsible for our cooler temperatures will also limit moisture returning to the region. Once today's showers move out, rain chances become pretty limited for the remainder of the week. That leaves us with several days of generally quiet, comfortable weather.

And after the weather we have experienced lately, quiet sounds pretty good.

We spent much of last week talking about dangerous heat, record-challenging temperatures, oppressive humidity and wondering when the pattern would finally break. It finally has. Today is the transition, Tuesday settles us completely into the cooler air, and the rest of the week finally looks and feels like the calendar says it should.

Summer had quite the encore, but fall is finally knocking on the door.

First. Accurate. Trusted.
First Warn Weather

FIRST WARN FORECAST

Morning, September 21, 2026

HIGHLIGHTS

Heat Wave Ends- A cold front pushed through and turned on the air conditioning.

Showers Ending- Scattered showers and storms are pushing to the east and will end.

Temps in the 70s- Expect a big drop from the 90s the past few days to the 70s.

Cooler Nights- The cooler temps will make it into the upper 40s and low 50s.

Nice Change- Expect less humidity and cooler temps for the rest of the week.

No More Heat- The cooler temperatures and lack of heat and humidity will be the norm until the end of the week when highs in the 70s and lows in the 40s are expected.

FIRST WARN FORECAST

We all knew it was coming,--Cool down and most of us (if not all) are happy it finally did.

The long stretch of high temperatures and even higher heat index values have broken and will be gone for at least the next several days. A cold front moved through the area last night and pushed the heat and humidity with it. Expect a big difference as you step outside.

A warm front has moved much of its moisture East, leaving Northern Missouri and Illinois mostly dry this morning. Areas of showers and thunderstorms remain to the West and South of the warm front. These will quickly move off to the East and fish out out this afternoon. A few showers may linger in Southeast Missouri. A new cluster of showers and storms will develop in this area this afternoon.

Today, instability will prevent areas of Southeast Missouri from falling too warm. Furthermore, most of the moisture will be pushed East and cooler air will move into the region from the West behind the front. So, while storms may develop, the environment will favor their organization.

With all this said, high temperatures for the region will drop from the 90's into the 70's and 80's (with Southeast Missouri being the warmest). Relative humidity will also drop making the weather feel quite comfortable.

Cloud cover is going to be the biggest factor in keeping temperatures down today. Areas to the south of us will have a hard time getting temperatures to rise very much above where they started this morning with the help of a northerly wind. Some places won’t get out of the 50s. Everyone is appreciating the break from the heat after last week.

All of this means that for the next few days, the majority of the Midwest and Southeast will experience below average temperatures for this time of year. Southeast Missouri will experience the same temperatures as the rest of the Midwest with highs only in the 70s.

Temperatures are expected to fall into the 50s across the Midwest on Tuesday. Some areas may even see lows in the upper 40s. Many places were experiencing highs over 90 degrees a few days ago. With the current cooler temperatures, many people will be opening their windows and enjoying temperatures they haven't seen in months.

We are expected to have these cooler temperatures for the next week. Northerly winds will keep temperatures down, and upper level winds will keep humid air from the south from returning to us.

We can expect milder temperatures moving forward, which is normal for this time of year. We will remain in the mid to upper 70s throughout the week, with the possibility of rising to the low 80s by next weekend. This will not be a repeat of the recent heat domes. This is what we can expect during the latter part of September.

The same weather conditions that have brought the cooler temperatures to our area have also pushed the moisturizer to our north. Therefore, we will also be experiencing dry conditions for the week.

After what we have recently experienced, most people are looking for calm conditions.

Of course, we have been eager for the recent heat to end. Wednesday will bring a cooler air mass, and the rest of the week's conditions should be in the normal range for September.

Although Summer will likely have a late return this year, the Autumnal Equinox is fast approaching.

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FirstWARN Alert: Severe Thunderstorm Warning for Jefferson County in MO until 11:30pm CDT. From Meteorologist Nick Palisch

FirstWARN Alert: Flood Warning for Lincoln County in MO. From Meteorologist Nick Palisch