textproduct: Springfield

KEY MESSAGES

- Patchy light fog this morning, mainly along and west of Highway 65.

- There is high confidence that much-above-average temperatures will occur early this week, with some locations challenging records around 80 degrees Monday. - Widespread 90-100% thunderstorm chances return Tuesday into Wednesday. There is currently a Slight Risk for severe weather and excessive rainfall with this system.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 400 AM CST Sun Mar 8 2026

Surface observations across the area are recording light and variable winds as a surface high pressure moves southeast behind an exiting cold front. The surface cold front is ahead of a positively tilted shortwave trough axis identified in water vapor imagery. The downstream trough branch extends from northeast Canada down through the Ozarks and into an upper-level closed low currently churning off the coast of the Baja Peninsula. Dry air within this branch is slowly clearing clouds from west to east across the area.

Patchy light fog along and west of Highway 65 this morning:

The surface high pressure and resulting light winds and clear skies is leading to strong radiational cooling. Lows are on track to reach the lower to middle 30s, with valley locations likely dipping below 30 F. Earlier in the night, light ground fog was observed to be developing in localized areas around the Springfield Metro. Some stations along and west of Highway 65 are reporting visibilities down to 3 miles. Expect patchy light radiational fog to continue through the morning before increasing southwesterly winds and sunny skies quickly burn off what has developed. Given marginal moisture behind the cold front, dense fog is not expected this morning.

Above normal temperatures return today:

The renewed southwesterly winds will reinvigorate warm air advection. Paired with sunny skies, highs are expected to rise into the middle 60s to lower 70s. Moisture will lag a bit behind the warmer temperatures, resulting in afternoon relative humidity values dropping into the 25-40% range. With winds at 5-12 mph across the area, localized areas of elevated fire weather will be present, especially north of I-44 where winds are on the upper-end of the aforementioned range. However, recent rain should make fuels less receptive, decreasing any appreciable concern. Lows tonight are then forecast to be in the lower 40s to lower 50s depending on lower vs. higher terrain.

Record highs near 80 F to be challenged Monday:

As the upper-level closed low churns off the Baja Peninsula coast, the main polar jet stream is progged to be positioned just south of the Canadian border, with mainly zonal flow Monday. This, along with continued southerly surface winds, will allow warm air to continue to build across the entire southern two-thirds of the CONUS. Clear skies will also exacerbate the forecasted warmth. As a result, high temperatures are forecast to be in the upper 70s to lower 80s Monday. This will challenge records across the area which are generally around 81 F. Based on the latest NBM, there is a 20-30% chance for these stations to tie or break that record. Either way, it will be well above average for early March Monday. Lows will also be very mild in the upper 50s to middle 60s, also challenging the record low max for several stations.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 400 AM CST Sun Mar 8 2026

Widespread 90-100% thunderstorm chances Tuesday into Wednesday:

Global ensembles are continuing to hone in on the evolution of the closed low early this week. The low is progged to lolly-gag its way eastward, somewhere near the intersection of AZ/NM and Mexico around mid-day Tuesday. LREF clusters still reveal some slight timing/amplitude differences (as is normal for closed low modeling), but the overall pattern is pretty much in agreement now. Of particular note, an energetic shortwave trough is also progged to be north of the closed low, moving through the northern Plains states in lock-step with the closed low. The resulting pattern produces amplifying heights east of the two waves across the central and eastern CONUS with broad strong southwesterly flow. This acts to open up the Gulf and continue to build an expansive warm and moist sector from south Texas, up into south Michigan, and eastward into the Appalachian spine.

This warm/moist sector will be quite anomalous for March with the NAEFS and ECMWF ESATs both showing >99.5th percentile PWATs (1.25-1.5") across the region for early March. This amount of moisture along with highs forecast in the upper 70s to lower 80s again will also produce decent instability at 1500-2500 J/kg. According to the ECMWF Extreme Forecast Index, this is also quite anomalous instability for March with values of 0.9-0.96 and a shift of the tail. Early March will feel like April/May with this type of air mass!

Furthermore, GFS/NAM/ECMWF deterministic models depict very broad and strong synoptic lift ahead of the closed low/polar jet wave (which will begin phasing into Tuesday night. The combination of very appreciable instability, lift, and moisture results in widespread chances for thunderstorms Tuesday into Wednesday, with the peak chances (70-100%) occurring Tuesday afternoon and through the night.

Slight (2 of 5) Risk for severe thunderstorms Tuesday:

Enhanced flow downstream of the closed low will add Shear to the expansive area of Lift, Instability, and Moisture. This completes our SLIM acronym for severe thunderstorm potential (missing one of those ingredients means there's a SLIM chance of severe storms). LREF joint probabilities of >500 J/kg MUCAPE; >35 kts 0-6 km bulk shear; >0.01" QPF confirm this with probabilities at 60-75%, up from 45-60% with yesterday's 00Z suite. Added confidence comes from the SREF with a 70-90% chance of the Supercell Composite Parameter exceeding 1 from south Texas up into Michigan and a bullseye of higher probs from the Red River Valley, through the Ozarks, and into the Mid- Mississippi Valley.

The main severe risk looks to occur later Tuesday night with a cold front surging south associated with the polar jet wave. This cold front would surge through the juiced up environment, and would make a damaging wind threat the main driver for the Slight (2 of 5) Risk.

With that said---much like Friday's severe event, there is a scenario for open warm sector storm development Tuesday afternoon/evening. Synoptic-scale ascent looks much broader and stronger than Friday's event, and NAM/GFS/ECMWF deterministic models do depict a subtle mid-level shortwave moving through the flow during peak heating Tuesday. If this scenario were to occur, the environment in place would support supercells and/or bowing clusters with damaging wind gusts up to 60-70 mph, hail up to 2 inches, and a few tornadoes all possible. This will be conditional on both synoptic ascent and any surface lift (which appreciable lift along synoptic fronts would stay north of our area). Otherwise, the main risk comes becomes a damaging wind risk with the surging cold front Tuesday evening into the overnight hours.

Slight (2 of 4) Risk for excessive rainfall and flooding Tuesday:

With anomalous moisture/instability for this time of year, excessive rainfall will also be a concern with any thunderstorms. This is especially true as the ground is already saturated from the past few rounds of rain. Therefore, a flooding threat will also need to be monitored even though the main threat of storms comes with a quick line along the cold front. The NBM gives a 70-80% chance for most areas to see at least another inch of rain with this system.

Above average temperatures continue for the rest of the week:

Behind the system, temperatures are forecast to marginally cool, but with the polar jet stream progged to stay north of the area, above normal temperatures are still expected. Highs in the 60s are expected Wednesday through Friday, with the coolest day being Thursday in the middle 50s to lower 60s. Lows range from the middle 30s to upper 40s. NBM 25th-75th percentile spreads are generally small for this timeframe, indicating good confidence in these temperature ranges through the end of the week.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 555 AM CDT Sun Mar 8 2026

Some light patchy fog/mist is impacting the TAF sites, but visibilities have stayed just above MVFR level. JLN may be the best candidate to see MVFR visibilities before 14Z. Otherwise, the light fog/mist will give way to clear skies and VFR conditions after 14-15Z.

Winds will become southwesterly at 5-10 kts after 14-15Z, slightly shifting to southerly after 23-01Z. As a low-level jet moves overhead tonight, around 40-45 kts of LLWS will be present at JLN after 06Z. SGF and BBG will see more marginal LLWS at 35-40 kts.

SGF WATCHES/WARNINGS/ADVISORIES

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