NZUS93 KILX 112025 LLLILX ILZ027>031-036>038-040>057-061>063-066>068-071>073-120825- Public Information Statement National Weather Service Lincoln IL 325 PM CDT Tue Mar 11 2025 Tonight through Thursday A robust lake-enhanced backdoor front has barrelled through the region with colder air now gradually oozing inland in its wake. Winds will remain gusty through the rest of the afternoon, but will continue to gradually ease through the evening. Temperatures tonight will meander their way down into the upper 20s and lower 30s west of the Fox Valley, and into the low to mid 30s elsewhere. Modest warm advection will develop aloft tonight as 925-850 mb winds turn south to southwesterly. At this point, all this looks to encourage may be some pockets of increased mid-level cloud cover that will drift north through the region overnight. Wednesday will feature a large north-south temperature gradient across the area. Persistent onshore flow and a reinforcing afternoon lake breeze likely to hold highs in the low 40s lakeside, while locales south of I-80 will see temperatures rocket into the 60s and possibly even near 70 in spots. Conditions on Thursday look to be largely similar to those on Wednesday, just perhaps a few degrees warmer. Friday and Friday night A vigorous mid-latitude cyclone is expected to rapidly take shape across the central Plains on Thursday night and Friday as an impressive–nearly 120 kt–500 mb jet streak surges eastward across southern New Mexico and the Caprock Escarpment of west Texas. As the left exit region of this incredible upper jet fans out across central plains, intense lee cyclogenesis will commence in earnest late Thursday night and Friday morning. Intense pressure falls across western Kansas/southwest Nebraska are nearly ubiquitously advertised across the guidance suite, with a roughly mid 970s mb low progged to scoot into central Kansas through midday on Friday. Locally, the effects of this burgeoning surface low will be increasingly gusty southerly winds and temperatures likely soaring well into the 70s across pretty much the entire forecast area. The lone exception could be lakeside Lake County where the northward-retreating boundary will likely get hung up, with a late day lake breeze offering a reinforcing push of lake-chilled air. That said, the low-level mass response by early evening looks significant enough that any lake breeze may eventually get shunted into Wisconsin. Forecast soundings suggest that while tufts of high cloud cover, along with diurnally-driven cumulus may develop through the day, none of this looks opaque enough to really hold insolation down. If things remain entirely sunny, it wouldnt be difficult to crank out a few near 80 degree readings across our southwest locales. Southerly winds will increase through the day on Friday as mixing deepens into the base of an intensifying LLJ. Forecast soundings suggest gusts could increase through 40-45 mph by mid-late afternoon. Some signals that some locales could near formal Wind Advisory levels, with the greatest chances for this south and west of a Rockford to Valparaiso line. These types of scenarios sometimes turn into sneaky fire weather set-ups. In this case, even with increasing mixing, deeper moisture is forecast to gradually pile into the region from the south through the day. This should yield RH values holding steady above critical thresholds, but something well continue to keep a close eye on. If this returning moisture ends up being shallower than presently depicted, dewpoints would more easily mix out/down during the afternoon yielding increased fire weather concerns. No precipitation is expected through the daylight hours on Friday with capping in place along with forcing displaced wells to our west. A dryline (impressive to see one this far north and east this time of year) will serve as an initial focus for thunderstorm development across southwest Iowa and western Missouri on Friday afternoon. With such intense large scale forcing, even though a considerable cross-boundary component to deep layer shear vectors is forecast, global guidance seems to depict a gradual transition to a strongly-forced line (or several lines) of convection as things evolve into the evening. Guidance seems to be settling on an arrival time for this activity into our forecast area during the mid-late evening timeframe, although some continued refinement will occur over the coming days. Instability remains one of the big uncertainties related to any strong-severe threat locally, with a general dearth of near-surface CAPE advertised. Concern, however, is that wind fields will be absolutely screaming just off the deck, with nearly 70 kt winds advertised around 3 kft. Commensurately, all low-level shear metrics are off the charts. If a well-developed/mature QLCS does indeed develop and sustain itself into the region amid otherwise increasing nocturnal inhibition, a severe wind threat and potential for embedded spin-ups would be possible. Theres still too much uncertainty regarding convective mode/evolution to pin down the severe threat, but the mid-late Friday evening period bears close watching. Saturday Precipitation should largely exit the region by daybreak Saturday. Some potential for lingering showers across far NW Illinois, but currently things look generally dry. The main focus on Saturday is on the gradient wind threat, with 50+ knot winds advertised at 850 mb rounding the base of the main upper low. Forecast soundings depict mixing at least into a portion of this flow with rapidly steepening , although theres some uncertainty regarding the degree of lingering low-level stratus and what impacts (if any) this will have on stunting vertical mixing. Regardless, there is a concerning signal for a potentially significant high wind event in the vicinity, if not within our forecast area. Finally, am also a bit concerned that dewpoints may briefly mix out sufficiently to drive RH values down ahead of the incoming cold front. If this occurs, an elevated to potentially briefly near-critical fire danger could materialize. This is currently not the most favored scenario, but one well also be watching closely. Sunday-Monday: Looks like a brief cool down to near normal temps Sunday, followed by a potential warm up and a return to above average temps by Monday. Given the volatility of the forecast prior to this period, forecast confidence is on the lower end of the spectrum for this time frame. $$