273
FXUS63 KIWX 181937
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
237 PM EST WED FEB 18 2026
KEY MESSAGES
- HIGHS IN THE 60S ON THURSDAY ARE WITHIN 5 DEGREES OF RECORD
LEVELS.
- THUNDERSTORMS WILL BE POSSIBLE ON THURSDAY. A MARGINAL RISK
FOR SEVERE WEATHER EXISTS MAINLY DURING THE LATER AFTERNOON ON
INTO THE EVENING WITH GUSTY WINDS, HAIL, AND A TORNADO AS THE
MAIN THREATS.
- COOLER AIR ARRIVES FRIDAY WITH SNOW BECOMING MORE LIKELY,
ESPECIALLY BY SUNDAY MORNING.
DISCUSSION
ISSUED AT 228 PM EST WED FEB 18 2026
WITHIN THIS -PNA PATTERN OF A TROUGH IN THE WEST AND A RIDGE IN THE
EAST, THE SENSIBLE WEATHER IS WARMER TEMPS ALONG WITH WAVES EJECTING
AT SOME TRAJECTORY TOWARDS THE UPPER MISSISSIPPI VALLEY AND LOWER
GREAT LAKES AREA. AFTER THE MORNING RAIN, THE COLUMN LOOKS TO DRY
OUT WITH BIG CHANGES COMING AS 50 DEGREE DEW POINTS THIS MORNING
DROP TO THE 30S THIS EVENING. AS THIS HAPPENS, GRADIENT WEAKENS THIS
AFTERNOON AND THE MIXING HEIGHT STRUGGLES TO GET MUCH HIGHER THAN
850 MB AND THIS KEEPS BREEZY GUSTS BELOW 30 KTS. THIS IS STILL
ENOUGH TO DRY OUT GRASSES ABOVE THE GROUND AND POTENTIALLY GET TO
LEAVES ON GROUND. AS SUCH, CANNOT COMPLETELY RULE OUT A GRASSY FIRE
SCENARIO, BUT SNOWMELT AND THE MORNING RAIN MAY BE ABLE TO KEEP THE
GROUND SOMEWHAT WET YET.
AS AN UPPER LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND NORTHERN
PLAINS/NORTHERN GREAT LAKES AREA TONIGHT, ANOTHER SURFACE LOW EJECTS
OUT OF THE ROCKIES AND INTO THE CENTRAL PLAINS TOMORROW MORNING AND
REACHES CENTRAL IL BY THURSDAY EVENING. AT THE SAME TIME, A SLOW
EASTWARD MEANDERING COLD FRONT LOOKS TO STALL AROUND THE US-24 AREA
THIS EVENING. AS THAT SURFACE LOW APPROACHES, IT MAY BE ABLE TO
SHOVE THE BOUNDARY NORTHWARD THURSDAY AM. AN INITIAL WAVE PUSHES
NORTHWARD THROUGH THE AREA THURSDAY MORNING, AND INITIALLY, IT
LOOKED LIKE THIS MAY BE WHAT INITIATES CONVECTION AS IT MOVES NORTH
AND EAST WITH THE FRONT. HOWEVER, IT NOW APPEARS LIKE A SECOND WAVE
MOVING INTO THE AREA DURING THE AFTERNOON/EVENING MAY BE THE MAIN
FORCING FOR THE EVENT AND COULD SET OFF SOME THUNDERSTORMS AT THAT
POINT. INSTABILITY APPEARS TO BE THE LIMITING FACTOR FOR THIS SETUP
AS MORNING CONVECTION COULD LEAVE BEHIND DEBRIS CLOUDS AND PUSH ANY
OUTFLOW BOUNDARIES SOUTH, STUNTING LOW LEVEL INSTABILITY GENERATION.
THE COLD FRONT WAITS UNTIL THURSDAY NIGHT TO MOVE THROUGH SO SHOWER
AND THUNDERSTORM GENERATION ARE STILL POSSIBLE, BUT BY THIS
POINT, INSTABILITY WOULD LIKELY BE WORKED OVER. THURSDAY'S
HIGHS LOOK TO BE IN THE 50S AND 60S, BUT WOULD TREND DOWNWARD
FOR FRIDAY, WITH HIGHS IN THE 40S MORE LIKELY BY THEN. RAIN
WOULD BE FINISHING UP NORTH OF US-6 AS THE MAIN SHORTWAVE
ASSOCIATED WITH THE DEEPENING LOW PRESSURE SYSTEM FINALLY MOVES
INTO THE EASTERN GREAT LAKES BY FRIDAY AFTERNOON/EVENING.
BETWEEN FRIDAY AND SATURDAY, THE AFOREMENTIONED TROUGH OVER THE
WESTERN CONUS TRANSLATES EASTWARD AND UPPER TRAJECTORIES TAKE A MORE
SOUTHWARD STORM TRACK ALLOWING COLD AIR TO COME IN ON THE BACKSIDE
OF THE EASTWARD-MOVING TROUGH. THIS ALLOWS FOR NEGATIVE 850 MB
TEMPERATURES TO ARRIVE IN THE AREA, MAKING IT MORE CONDUCIVE FOR THE
ARRIVAL OF SNOW. THERE COULD BE SOME LAKE ENHANCEMENT WITH THIS, BUT
IT APPEARS TO BE FORCED MAINLY BY A TROUGH COMING DOWN ON THE
WESTERN SIDE OF AN UPPER LOW EAST OF THE GREAT LAKES WITHOUT A
VIGOROUS SHORTWAVE IN THE VICINITY OF LAKE MI, LIMITING SNOW
OUTPUT. TEMPERATURES ALSO LOOK TO BE IN THE LOW TO POTENTIALLY
MID 30S, WHICH CAUSES WET SNOW RATIOS. EVEN STILL, MODELS DO
HAVE TIME PERIODS WHERE LAKE ENHANCED INVERSION CREEP UP TO 5
TO 6 KFT, WHICH MAY ALLOW FOR AN AREA OF ADVISORY LEVEL SNOW.
LAKE ENHANCEMENT LETS UP LATER MONDAY/MONDAY NIGHT AS HIGH
PRESSURE AND MID LEVEL RIDGING FINALLY WORKS ITS WAY INTO THE
AREA. TEMPERATURES LOOK TO CREEP BACK UP BY MIDWEEK NEXT WEEK
AS WAA TAKES OVER. NEXT SYSTEM ARRIVES DURING THE TUE/WED TIME
FRAME.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1232 PM EST WED FEB 18 2026
AREA OF LOW LEVEL LIFT AND ASSOCIATED SHOWERS/ISOLATED STORMS
HAS SHIFTED WELL EAST OF BOTH SITES, WHICH ARE NOW FIRMLY
ENTRENCHED IN THE WARM SECTOR OF THE APPROACHING SYSTEM. WIND
GUSTS OF 25 TO LOCALLY 35 KTS WILL PERSIST THROUGH THE AFTERNOON
BEFORE DIMINISHING. A FURTHER INCREASE IN LOW LEVEL MOISTURE AND
A STALLED WEAK BOUNDARY MAY ALLOW FOR THE DEVELOPMENT OF SOME
STRATUS/FOG AT BOTH SITES (KFWA HAVING THE BEST SHOT) OVERNIGHT.
WILL MAINTAIN PREVIOUS TEMPOS TO HANDLE FOR NOW, BUT NOT
EXPECTING WIDESPREAD ISSUES.
FOCUS THEN BECOMES CHANCES FOR SHOWERS AND A FEW STORMS AHEAD OF
THE MAIN TROUGH AND FRONT WHICH WILL IMPACT THE AREA OUTSIDE OF
THE CURRENT FORECAST PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...ROLLER
AVIATION...FISHER
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