047
FXUS63 KILX 190928
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
328 AM CST MON JAN 19 2026
KEY MESSAGES
- A COLD WEATHER ADVISORY REMAINS IN EFFECT THROUGH MIDDAY FOR
WIND CHILL VALUES OF 10 TO 20 DEGREES BELOW ZERO. THE THREAT OF
COLD TO OCCASIONALLY VERY COLD WEATHER WILL RETURN LATER THIS
WEEK.
- NEAR DAILY CHANCES (10-30%) FOR LIGHT SNOW EXIST THROUGHOUT THIS
WEEK AND UPCOMING WEEKEND, BUT WITH LITTLE OR NO NEW
ACCUMULATION.
DISCUSSION
(THROUGH NEXT MONDAY)
ISSUED AT 325 AM CST MON JAN 19 2026
PERSISTENT, MULTI-DAY PERIODS OF COLD TO OCCASIONALLY VERY COLD
TEMPERATURES IS THE PRIMARY FORECAST CONCERN FOR THE MIDWEST AND
GREAT LAKES REGIONS OVER THE NEXT 7 TO 10 DAYS. THIS PROLONGED
COLD SNAP IS LARGELY DRIVEN BY A SIGNIFICANT ALIGNMENT OF
ATMOSPHERIC TELECONNECTIONS: THE ARCTIC OSCILLATION (AO), NORTH
ATLANTIC OSCILLATION (NAO), AND EAST PACIFIC OSCILLATION (EPO) ARE
ALL DEEPLY NEGATIVE.
ANALYSIS OF THE RECENT NORTHERN HEMISPHERE 5-WAVE PATTERN
CONFIRMS THIS SETUP. A MASSIVE RIDGE OF HIGH PRESSURE IS STATIONED
OVER THE GULF OF ALASKA, WHICH IS A HALLMARK OF A DEEPLY NEGATIVE
EPO. AT THE SAME TIME, AN ANOMALOUS RIDGE IS IMPINGING UPON THE
NORTH POLE, CHARACTERISTIC OF A DEEPLY NEGATIVE AO. THIS
CONFIGURATION PROMOTES THE EQUATORWARD DISPLACEMENT OF THE POLAR
VORTEX. CONSEQUENTLY, LOBES OF ARCTIC AIR ARE EXPECTED TO
PERIODICALLY SLIDE DOWN THE EASTERN PACIFIC RIDGE TOWARD THE GREAT
LAKES THROUGH THE REMAINDER OF THE MONTH. THE NET IMPACT WILL BE
A SUSTAINED PERIOD OF BELOW-NORMAL TEMPERATURES, WITH READINGS
PROJECTED TO BE 10 TO 20 DEGREES BELOW SEASONAL AVERAGES. THIS
MEANS THERE WILL BE A HANDFUL OF DAYS FORTHCOMING WHERE AFTERNOON
HIGHS STRUGGLE TO RISE INTO THE 20S WHILE OVERNIGHT LOWS FALL NEAR
OR BELOW ZERO.
AN ACTIVE STORM TRACK WILL COINCIDE WITH THIS COLD AIR, BRINGING
A WAVETRAIN OF DISTURBANCES ACROSS THE UPPER MIDWEST. THESE QUICK-
HITTING, CLIPPER-LIKE SYSTEMS WILL FAVOR THE UPPER MIDWEST AND
MAY OCCASIONALLY IMPACT CENTRAL ILLINOIS DIRECTLY; HOWEVER, THEY
ARE NOT EXPECTED TO DEVELOP INTO SIGNIFICANT MID-LATITUDE
CYCLONES, AND THEREFORE ARE NOT FORECASTED TO PRODUCE SIGNIFICANT
SNOWFALL OVER THE NEXT WEEK.
THE TREND IN THE EASTERN PACIFIC OSCILLATION (EPO) IS A KEY
TELECONNECTIONS TO WATCH. WHILE CURRENTLY DEEPLY NEGATIVE, THE
INDEX IS PROJECTED TO TREND TOWARD NEUTRAL BY THE END OF THE WEEK.
THIS SHIFT COINCIDES WITH A SLIGHT WEAKENING AND REPOSITIONING OF
THE ALASKAN RIDGE.
THE CHANGE WILL ALLOW MOISTURE TO LEAK UNDER THE RIDGE, A
DEVELOPMENT SUPPORTED BY MOST MODEL GUIDANCE. SPECIFICALLY, A
CLOSED UPPER LOW IS EXPECTED TO MEANDER PAST THE CALIFORNIA COAST,
DRAWING BOTH PACIFIC AND GULF MOISTURE INTO THE SOUTHERN US.
THIS PATTERN IS ANTICIPATED TO LEAD TO A SUBSTANTIAL OVERRUNNING
EVENT THIS WEEKEND. WARM, MOIST AIR WILL RIDE OVER A STRONG COLD
DOME DESCENDING ACROSS THE MIDWEST, CREATING A THREAT OF SLEET AND
FREEZING RAIN ACROSS THE SOUTH, AND ACCUMULATING SNOW ACROSS
PARTS OF THE OZARKS AND TENNESSEE VALLEY.
FOR CENTRAL ILLINOIS, HOWEVER, RECENT FORECAST CYCLES HAVE
INDICATED A COLDER AND DRIER TREND FOR THE WEEKEND, WITH THE MOST
IMPACTFUL WINTRY PRECIPITATION LIKELY TRACKING JUST SOUTH OF THE
AREA.
MJA
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 930 PM CST SUN JAN 18 2026
AN ARCTIC COLD FRONT WILL CROSS THE TERMINALS BY 06Z, VEERING
WINDS WNW AND INCREASING GUSTS TO 25-30 KT. THESE GUSTS WILL BE
COMMON THROUGH MONDAY AFTERNOON THEN DIMINISH AROUND SUNSET.
ISOLATED SNOW SHOWERS ARE POSSIBLE ESPECIALLY NEAR THE I-74
TERMINALS OVER THE NEXT FEW HOURS, SO INCLUDED VCSH, AND THERE IS
A LOW PROBABILITY THAT A SHSN WILL IMPACT A TERMINAL AND REDUCE
CATEGORY BRIEFLY. OTHERWISE, CEILINGS WILL BE NEAR THE MVFR/VFR
THRESHOLD FOR KPIA- KBMI-KCMI OVERNIGHT WITH MOST GUIDANCE
SUPPORTING KEEPING PREDOMINANT VFR CONDITIONS.
25
ILX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL NOON CST TODAY FOR ILZ027>031-
036>038-040>057-061>063-066>068-071>073.
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