982
FXUS63 KIND 152310
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
710 PM EDT SUN MAR 15 2026
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS EXPECTED LATE TODAY, WITH SEVERE STORMS
POSSIBLE MAINLY FROM 7 PM TO 2 AM EDT
- HIGH WIND WARNING UNTIL 8PM, THEN WIND ADVISORY FROM 8PM TODAY
TO 8AM MONDAY. WIND GUSTS BETWEEN 50-60 MPH POSSIBLE TODAY, THEN
UP TO 45 MPH OVERNIGHT.
- SNOW SHOWERS LIKELY ON MONDAY WITH UP TO AN INCH POSSIBLE
- MUCH COLDER AIR EARLY THIS WEEK, WIND CHILLS NEAR ZERO TUESDAY
MORNING
MESOSCALE UPDATE
ISSUED AT 710 PM EDT SUN MAR 15 2026
A WARM AND RELATIVELY MOIST AIRMASS IS IN PLACE ACROSS CENTRAL
INDIANA EARLY THIS EVENING. 22Z OBS SHOW A THERMAL RIDGE EXTENDING
SW-NE ACROSS MUCH OF CENTRAL INDIANA, WITH THE MOIST AXIS (WITH
DEWPOINTS FROM 55-59 F) OFF TO THE WEST IN CENTRAL/SOUTHERN IL.
MODEST PRESSURE FALLS (2-3 MB/2HR) ARE PRESENT EAST OF A SURGING
FRONTAL BOUNDARY OVER THE MS VALLEY. THE STRONGEST PRESSURE
FALL/RISE COUPLET WILL CONTINUE TO REMAIN JUST SOUTH OF CENTRAL
INDIANA.
AN UPSTREAM QLCS OVER IL IS ORIENTED ROUGHLY 30 DEGREES OFF PARALLEL
TO THE DEEP SHEAR VECTOR. THEREFORE, THE TORNADO THREAT WILL BE
OVERALL LIMITED, WITH DAMAGING WINDS THE PRIMARY HAZARD GIVEN STEEP
LOW LEVEL LAPSE RATES (PER RECENT KIND ACARS SOUNDINGS) AND STRONG
DOWNDRAFTS INTO BOUNDARY LAYER FLOW OF 50-60 KTS AT 850 MB PER IND
VWP DATA. HOWEVER, GIVEN THE DEGREE OF LOW LEVEL SHEAR (150-200
M2/S2 0-1KM SRH) EMBEDDED MESOVORTICES AND TORNADO POTENTIAL WILL
EXIST. THESE WILL BE MOST LIKELY WHERE MESO-BETA COLD POOL-DRIVEN
SURGES DRIVE LOCALIZED LINE REORIENTATION TO MORE NORTH-SOUTH
STRUCTURES AND MORE PERPENDICULAR TO THE DEEP SHEAR VECTOR.
THE THREAT FOR WIDESPREAD SEVERE WEATHER WITH THE QLCS WILL REACH
THE IN/IL BORDER AROUND 8 PM. ISOLATED TS ACTIVITY DEVELOPING AHEAD
OF THE MAIN QLCS WILL HAVE THE POTENTIAL FOR ISOLATED DAMAGING WIND
GUSTS GENERALLY WEST OF I-65.
SHORT TERM (THIS EVENING THROUGH MONDAY)
ISSUED AT 310 PM EDT SUN MAR 15 2026
SURFACE LOW PRESSURE CONTINUES TO STRENGTHEN OVER NORTHERN ILLINOIS
AS A VORT MAX AMPLIFIES SIGNIFICANTLY OVER THE GREAT PLAINS. THE LOW
WILL THEN TRACK NORTHEASTWARD INTO THE GREAT LAKES TONIGHT, DRAGGING
A STRONG COLD FRONT THROUGH INDIANA BETWEEN 00Z-06Z. AS OF 2PM,
INDIANA LIES FIRMLY WITHIN THE SYSTEM'S WARM SECTOR. TEMPERATURES
HAVE SURGED INTO THE 70S AS STRONG MASS RESPONSE PROMOTES CONTINUED
WARM AIR ADVECTION. ADDITIONALLY, A TIGHTENING MSLP GRADIENT HAS
LEAD TO STRONG GUSTY WINDS WITH NUMEROUS OBSERVATIONS OF GUSTS
BETWEEN 50 TO 60 MPH. A HIGH WIND WARNING IS IN EFFECT UNTIL 8PM,
WITH A WIND ADVISORY FROM 8PM TODAY TO 8AM MONDAY.
TURNING OUR ATTENTION TO THE SYSTEM'S COLD FRONT, THIS FEATURE WILL
ACT AS A FOCAL POINT FOR THUNDERSTORM INITIATION THIS AFTERNOON OVER
ILLINOIS. MOISTURE ADVECTION AHEAD OF THE FRONT IS MODEST, WITH DEW
POINTS CURRENTLY INTO THE MID 40S TO LOW 50S. HIGH-RESOLUTION
GUIDANCE SUGGESTS A LAST-MINUTE SURGE OF SLIGHTLY HIGHER MOISTURE
CONTENT IMMEDIATELY AHEAD OF THE FRONT, WHICH MAY IMPACT SEVERE
WEATHER POTENTIAL THIS EVENING.
TONIGHT'S SEVERE WEATHER THREAT
AS MENTIONED ABOVE, TONIGHT'S THREAT DEPENDS ON AVAILABLE MOISTURE
AND THEREFORE LOW-LEVEL INSTABILITY. FIRST, WE'LL DISCUSS THE
AVAILABLE DYNAMICS, WHICH CERTAINLY ARE NOT LACKING. A STRONG LOW-
LEVEL JET FROM THE SOUTH BETWEEN 50-70KT (925MB-850MB LAYER) IS
EXPECTED TO DEVELOP THIS EVENING. THIS WILL RESULT IN HIGHLY
ELONGATED AND CURVED HODOGRAPHS, SIGNIFYING ABUNDANT SPEED AND
DIRECTIONAL SHEAR. ACARS SOUNDINGS SHOW A DEEP ELEVATED MIXED LAYER
FROM 850MB TO 650MB, WHICH WILL ACT TO MITIGATE OPEN WARM SECTOR
CONVECTION. AS SUCH, FORCING LOOKS TO BE CONFINED TO THE FRONT
ITSELF. WITH A LARGELY SOUTHWESTERLY SHEAR PROFILE, A NORT-SOUTH
ORIENTED BOUNDARY, AND A FOCUSED REGION OF FORCING...A LINEAR MODE
IS PREFERRED FOR TONIGHT'S CONVECTION.
REGARDING HAZARDS, THE LINEAR CONVECTIVE MODE COMBINED WITH THE
POTENCY OF THE LOW-LEVEL JET WILL FAVOR SEVERE (60-70MPH) TO
SIGNIFICANTLY SEVERE (70-80MPH) WIND GUSTS AS THE PRIMARY THREAT.
HOWEVER, WITH SUCH A STRONGLY SHEARED LOW-LEVEL ENVIRONMENT,
INDICATED BY THE LONG CURVED HODOGRAPHS MENTIONED ABOVE, A QLCS
TORNADO THREAT IS ALSO PRESENT. THIS THREAT IS CONTINGENT ON NEAR-
SURFACE MOISTURE/INSTABILITY. GREATER MOISTURE AND NEAR SURFACE
LAPSE RATES, AND THUS LOWER LCLS WOULD INCREASE THE QLCS TORNADO
THREAT WITH THE INVERSE ALSO TRUE. QLCS SPIN UP POTENTIAL SHOULD BE
MAXIMIZED IN LINE SEGMENTS THAT BECOME PERPENDICULAR TO THE
EFFECTIVE SHEAR VECTOR WITHIN THE LOWEST KILOMETER OF THE
ATMOSPHERE. THIS WOULD ALLOW FOR GREATER REAR INFLOW JET (RIJ) SURGE
POTENTIAL AND VERTICAL SHEARING VORTICITY THAT COULD THEN BE
STRETCHED BY UPDRAFTS.
SNOWFALL POTENTIAL
TEMPERATURES FALL QUICKLY BEHIND THE FRONT, WHICH WILL PASS THROUGH
THE AREA BETWEEN 00-09Z. BY 12Z MONDAY, MOST OF THE REGION LIKELY
FALLS TO AROUND FREEZING WITH CONTINUED STRONG COLD ADVECTION
CAUSING TEMPERATURES TO DROP THROUGH THE DAYLIGHT HOURS MONDAY.
STEEP LAPSE RATES WITHIN THE COLD AIR MASS WILL PROMOTE SCATTERED TO
NUMEROUS SNOW SHOWERS ON MONDAY. SOME OF THE SNOW SHOWERS COULD BE
BRIEFLY HEAVY, GIVEN STEEP LOW-LEVEL LAPSE RATES, WHICH MAY REDUCE
VISIBILITY AND LEAD TO HAZARDOUS TRAVEL. SNOWFALL LIKELY MELTS ON
CONTACT WITH ROADWAYS EARLY BUT AS TEMPERATURES DROP THROUGH THE DAY
SOME SLICK SPOTS MAY DEVELOP. TOTAL SNOWFALL ACCUMULATIONS SHOULD BE
LESS THAN AN INCH ON AVERAGE.
ADDITIONALLY, CONTINUED GUSTY WINDS BETWEEN 30-40 MPH THROUGHOUT THE
DAY MONDAY COMBINED TEMPERATURES FALLING THROUGH THE 20S MAY RESULT
IN WIND CHILLS IN THE TEENS. EVEN COLDER WIND CHILLS IN THE SINGLE
DIGITS ARE POSSIBLE TUESDAY NIGHT AS AMBIENT AIR TEMPERATURES FALL
INTO THE TEENS.
LONG TERM (MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EDT SUN MAR 15 2026
MUCH OF THE LONG TERM WILL BE DOMINATED BY NW FLOW AS VERY STRONG
CAA FROM THE EARLIER WEAK SYSTEM HELPS INDUCE HIGH PRESSURE IN THE
LOW LEVELS AND A DEEPENING TROUGH IN THE MID TO UPPER LEVELS. IN
RETURN, WINTER-LIKE CONDITIONS ARE EXPECTED FOR MONDAY NIGHT AND
TUESDAY. THE BIGGEST FORECAST CONCERN FOR THE BEGINNING OF THE LONG
TERM WILL BE CLOUD COVERAGE. THE STRONG SUBSIDENCE WITH AN UPSTREAM
DEEP TROUGH COULD LEAD TO A LOW STRATUS LAYER, BUT CONTINUED SURFACE
MIXING AND EMERGENCE OF MORE BROAD SUBSIDENCE THROUGH AVA COULD
PRODUCE SOME BREAKS. IF OVERCAST CONDITIONS REMAIN MONDAY NIGHT,
LOWS WILL LIKELY ONLY FALL INTO THE MID TO UPPER TEENS; HOWEVER, IF
THERE IS SOME CLEARING, POCKETS OF LOWS NEAR 10 DEGREE OR EVEN
LOWER IN THE VALLEYS WILL BE POSSIBLE. FOR HIGHS ON TUESDAY, TYPICAL
DIURNAL CURVES WITH 850MB TEMPERATURES AROUND -15C SHOULD LEAD TO
HIGHS IN THE MID 20S.
THE PATTERN BEGINS TO CHANGE MID WEEK AS 700-600MB WAVE PROGRESSES
EASTWARD. THIS WAVE HAS MODEST CVA AND WAA ATTACHED WITH IT, BUT THE
FORCING IS DISPLACED FROM THE LOW LEVELS KEEPING TEMPERATURES COLD
INITIALLY, THIS SHOULD LEAD TO A WEAK SNOWFALL EVENT TUESDAY NIGHT
INTO WEDNESDAY MORNING WITH SNOWFALL UP TO AN INCH POSSIBLE OVER
PORTIONS OF CENTRAL INDIANA. FOLLOWING THE PASSAGE OF THIS WAVE, LOW
LEVEL HIGH RISES AND TEMPERATURE GAINS WILL PROMOTE A LATE WEEK WARM
UP WITH HIGH BACK NEAR 60 BY THURSDAY.
AVIATION (00Z TAF ISSUANCE)
ISSUED AT 656 PM EDT SUN MAR 15 2026
IMPACTS:
- SOUTH WINDS WITH GUSTS BETWEEN 40-49KT THIS EVENING.
- THUNDERSTORMS AND MVFR CONDITIONS EXPECTED AFTER 00Z ENDING BY 04Z.
- SNOW SHOWERS WITH POCKETS OF IFR VIS POSSIBLE AFTER 08Z.
COVERAGE WILL LOWER BUT SNOW SHOWERS REMAIN POSSIBLE THROUGH
THE REST OF TAF PERIOD.
- WIND GUSTS REMAIN OVER 30 KTS THROUGH TOMORROW.
DISCUSSION:
STRONG WINDS WILL CONTINUE THROUGH A MAJORITY OF THE TAF PERIOD,
GENERALLY WITH SUSTAINED AROUND 20KT WITH GUSTS BETWEEN 30-40KT.
THERE WILL BE A BRIEF PERIOD TO BEGIN THE TAF PERIOD AT KIND AND
KBMG PRIOR TO A LINE OF THUNDERSTORMS WHERE STRONGER WIND GUSTS OF
UP TO 50KT WILL BE POSSIBLE. SCATTERED RAIN SHOWERS ARE ALSO
POSSIBLE IN THIS PRE-LINE ENVIRONMENT. WINDS WILL INITIALLY BE
SOUTHERLY BEFORE BECOMING WESTERLY FOLLOWING LINE PASSAGE.
A LINE OF THUNDERSTORMS WILL MOVE WEST TO EAST THROUGH THE TERMINALS
BETWEEN 00Z-04Z. CONVECTION MAY BE SEVERE WITH WIND GUSTS UP TO
60KT, BUT IN THE GROUP ITS LEFT BELOW 50KT AT THIS TIME. IFR TO LIFR
VIS IS LIKELY WITHIN CONVECTION. AFTER THE LINE PASSES, MVFR
CEILINGS WILL BE LIKELY WITH LIGHT RAIN SHOWERS. THERE WILL BE A FEW
HOURS OF NO PRECIPITATION AROUND 08-12Z, BEFORE SNOW SHOWERS ARRIVE.
GREATEST SNOW SHOWER COVERAGE WILL BE IN THE MORNING AND EARLY
AFTERNOON, BUT THE THREAT WILL CONTINUE THROUGH 06Z. BRIEF IFR VIS
WILL BE POSSIBLE WITHIN THESE SNOW SHOWERS.
IND WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING UNTIL 10 PM EDT THIS EVENING FOR INZ021-030-
031-037>042-046>049-054>057-062>065-070>072.
WIND ADVISORY UNTIL 8 AM EDT MONDAY FOR INZ021-028>031-035>049-
051>057-060>065-067>072.
HIGH WIND WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ028-029-035-
036-043>045-051>053-060-061-067>069.
MESOSCALE...CROSBIE
SHORT TERM...ECKHOFF
LONG TERM...UPDIKE
AVIATION...UPDIKE
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