textproduct: Springfield

KEY MESSAGES

- Light patchy fog again tonight into Monday morning (60-80% confidence). Freezing fog will not be an issue this time around as lows only drop to the middle 30s to lower 40s.

- Dry conditions and above normal temperatures expected through Wednesday.

- A pattern change brings 45-65% chances of widespread rain Thursday and possibly (15-30% chance) into Friday.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 230 PM CST Sun Jan 4 2026

The large-scale pattern today features broad ridging across the entire CONUS. Mid-level water vapor imagery highlights two branches of the jet stream ending at the base of mid-level shortwaves. One branch extends from central California into the Dakotas where a mid-level shortwave and surface low pressure system is currently moving through. The second branch extends from the Baja Peninsula into Oklahoma where another mid-level shortwave is moving through. The surface low in the Dakotas is vacuuming in air from the south, renewing warm air advection across our area. Highs are on track to reach the mid-40s to mid-50s despite high cloud cover.

Light patchy fog again tonight into Monday morning:

Moisture has also been advecting into the region through the course of the day. HREF guidance suggests cloud cover will clear as the backside of the subtle 700mb shortwave moves through the area. Both factors may allow for some patchy light fog again tonight into Monday morning much like last night. However, one major difference includes a low-level jet developing overhead creating 8-12 mph southerly winds tonight. This may be enough to keep the low-levels mixed and unable to produce fog and side more with low stratus. Either way, the probability for dense fog is very low (<10%), so impacts are not expected. Furthermore, low temperatures are forecast to be in the mid-30s to lower 40s which will inhibit any freezing fog potential.

Dry conditions above normal temperatures through Wednesday:

The ridge axis is progged to be directly overhead Monday, bringing well above normal high temperatures in the lower to middle 60s and lows in the middle to upper 40s.

Global ensembles then flatten out the ridge a bit Tuesday as a small shortwave trough traverses the northern Plains. A weak cold front will push through with this shortwave, but with the flat trough and jet streak north of the area, any appreciably cooler air will stay well north of the area keeping highs in the 60s Tuesday with lows slightly cooler in the mid-30s to lower 40s Tuesday night.

Heights then rise ahead of the next incoming trough/system, allowing for above normal highs again in the middle to upper 60s Wednesday.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/

Issued at 230 PM CST Sun Jan 4 2026

Pattern change brings 45-65% chances of showers Thursday:

Global ensembles seem to have figured out the large-scale troughing pattern coming into the area as NBM probability of precipitation across the area has finally increased from 30-50% to 45-65%. Despite this general agreement, clusters still reveal slight differences in the timing/position of the shortwave trough. This is resulting in drastic "wiggles" of the axis of greatest rainfall amounts across the area. The 13Z NBM has this axis across our far southeast counties. However, 12Z global models (which most aren't included in the 13Z NBM) depict a shift further northwest with the axis over the I-44 corridor. We'll have to see if this trend continues to hold weight. Ignoring pinning down where the greatest amounts land for a second, the main message is that widespread, minimally impactful rain showers are possible for much of the area (45-65%).

While the main message leads to minimal impacts, there are some nuances to the forecast that model members are hinting at the potential for. Firstly, the NBM forecast calls for mainly rain showers as the "Probability of Thunder" was too low to introduce thunderstorms in the forecast. However, global deterministics like the GFS and ECMWF both bring in enough CAPE for some embedded thunderstorms. As a result, would not be surprised to see subsequent forecast packages introduce the mention of lightning.

Secondly, with the introduction of thunderstorm potential paired with the strong trough and deep low pressure system expected, a low excessive rainfall potential should be considered. The chance is at 5% as the WPC has us in a Marginal (1 of 4) Risk for excessive rainfall Thursday and Thursday night. This concern would need to be heeded if a few things happen with the forecast. First, thunderstorm potential pans out. And second, a more meridional trough orientation occurs, resulting in stronger synoptic lift along the frontal boundary. For what it's worth, the 12Z GFS does show this scenario, resulting in a swath of 2-3 inches of rain along I-44. The 12Z ECMWF deterministic depicts thunderstorms, but has a more southwesterly trough orientation which keeps amounts around one inch. That said, those are just 2 of the 100 of model members. The current NBM probability of exceeding one inch of rain is only 20-40%, so we will have to continue to monitor to see if the trend seen in the deterministics translates to the ensemble mean.

Lastly, if the trough assumes or more positively-tilted orientation, this would delay its exit which could bring the potential for additional light precipitation on the backside cold front. This could bring either rain or snow. Once again, though, each scenario is particularly uncertain so we will have to monitor trends going forward.

Cooldown following the system; uncertainty in degree of cooling:

Model ensembles now agree in northwesterly flow overspreading the area in the wake of the system (shoutout to AI ensembles for predicting this before physical ensembles). This will result in a general cooldown. However, potential high/low temperatures are still very uncertain due to the notorious southwest CONUS closed low. Models will continue to struggle with this low until a few days before. Therefore, we can only offer a forecast of a cooldown. But that cool down could be into the lower 50s, or further into the middle 30s.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1102 PM CST Sun Jan 4 2026

VFR conditions are expected through the TAF period. There could be some patchy light fog in some river valleys across the area but not expecting any impacts at the TAF sites. Some low level wind shear is possible tonight with gusty southerly winds developing on Monday.

SGF WATCHES/WARNINGS/ADVISORIES

KS...None. MO...None.