663
FXUS63 KLOT 142352
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
652 PM CDT THU MAY 14 2026
KEY MESSAGES
- CHANCE FOR A PERIOD OF SHOWERS LATE TONIGHT INTO EARLY FRIDAY
MORNING. SCATTERED STRONG STORM CHANCES THEN EXIST AT TIMES
LATE FRIDAY THROUGH THIS WEEKEND.
- BETTER SHOT AT WIDESPREAD SHOWERS AND STORMS, SOME POSSIBLY
SEVERE, MONDAY INTO TUESDAY.
- TEMPERATURES TREND WARMER THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK.
DISCUSSION
ISSUED AT 215 PM CDT THU MAY 14 2026
SURFACE HIGH PRESSURE CENTERED OVER THE REGION WILL KEEP
CONDITIONS QUIET THROUGH THIS EVENING. A SUBTLE SHORT-WAVE AND
PUSH OF MID-LEVEL WAA TONIGHT WILL KICK OFF A ROUND OF SHOWERS
TONIGHT (AFTER 04Z). WITH A LACK OF INSTABILITY TONIGHT THE RISK
FOR ANY THUNDERSTORMS IS VERY LOW (LESS THAN 10%) AND IMPACTS
SHOULD BE MINIMAL. SHOWERS SHOULD DEPART TO THE EAST MID-MORNING
FRIDAY LEAVING THE REST OF THE DAY DRY WITH TEMPERATURES
PEAKING IN THE LOW TO MIDDLE 70S. WINDS ON FRIDAY WILL INCREASE
AS THEY BECOME SOUTHERLY, SUSTAINED WINDS OF 15-20 MPH ARE
EXPECTED THROUGH MUCH OF THE DAY WITH WIND GUSTS PEAKING AROUND
25-30 MPH. REFS SHOWS A BRIEF PERIOD OF 20-40% PROBABILITIES FOR
GREATER THAN 30 MPH GUSTS DURING THE LATE MORNING WITH
DIMINISHING PROBS THROUGH THE AFTERNOON AS THE PRESSURE GRADIENT
SLACKS OFF.
CAMS ARE IN GENERAL AGREEMENT THAT ANOTHER SHORT-WAVE WILL
EJECT OUT OF THE SOUTHWEST LATE FRIDAY AND PASS THROUGH
OTHERWISE ZONAL FLOW ALOFT. THIS FEATURE WILL BRING THE NEXT
CHANCE FOR THUNDERSTORMS TO THE REGION LATE FRIDAY INTO EARLY
SATURDAY MORNING. AHEAD OF THE SHORT-WAVE SURFACE DEW POINTS ARE
FORECAST TO INCREASE INTO THE MID 50S WHICH ALONG WITH AN EML
CAUSING STEEPENING MID-LEVEL LAPSE RATES (7-8 C/KM) WILL RESULT
IN ELEVATED INSTABILITY VALUES OF 1000-1500 J/KG. 0-6KM SHEAR
VALUES OF AROUND 50 KTS ARE ALSO EXPECTED DURING THIS TIMEFRAME
AS A 45-60KT JET STREAK PASSES OVER CENTRAL WI. THIS WILL CREATE
A PARAMETER SPACE CAPABLE OF SUPPORTING A FEW MARGINALLY SEVERE
ELEVATED THUNDERSTORMS ACROSS THE WESTERN HALF OF THE FORECAST
AREA WITH LARGE HAIL THE MAIN THREAT, HOWEVER, SPORADIC DAMAGING
WIND GUSTS ARE ALSO POSSIBLE.
A QUASI STATIONARY BOUNDARY IS EXPECTED TO SET UP SOMEWHERE
ACROSS THE REGION SATURDAY WHICH MAY PROVIDE THE FOCUS FOR
ANOTHER ROUND OF THUNDERSTORMS SATURDAY AFTERNOON/EVENING,
HOWEVER, EXACTLY WHERE THIS BOUNDARY SETS UP WILL IN PART BE
TIED TO HOW THE EARLY MORNING CONVECTION PLAYS OUT. SOUTH OF
THIS BOUNDARY LOW-LEVEL MOISTURE TRANSPORT WILL CONTINUE
THROUGHOUT THE DAY SATURDAY WITH DEW POINTS INCREASE INTO THE
LOW TO MID 60S AND TEMPERATURES WARMING INTO THE MID TO UPPER
70S RESULTING IN 1000-1500 J/KG OF SURFACE BASED INSTABILITY
WHICH WOULD SUPPORT AT LEAST ANOTHER ROUND OF STRONGER
THUNDERSTORMS. HOWEVER, MID-LEVEL CAPPING AND THE LACK OF A
STRONGER FORCING MECHANISM MAY LEAD TO MORE ISOLATED STORM
COVERAGE.
A TROUGH DIGGING INTO THE INTERMOUNTAIN WEST LATER INTO THE
WEEKEND AND EARLY NEXT WEEK WILL RESULT IN PROLONGED PERIOD OF
SOUTHWESTERLY FLOW BRING MORE SUMMER LIKE CONDITIONS (HIGH
TEMPERATURES IN MIDDLE 80S TO LOW 90S) TO THE REGION. ALONG WITH
THE WARMTH THERE WILL BE A CHANCE FOR THUNDERSTORMS EACH DAY
THROUGH TUESDAY AS A SERIES OF SHORT-WAVES MOVE ACROSS THE
REGION. SUNDAY THE BEST STORM CHANCES WILL COME DURING THE
MORNING ON THE LEADING EDGE OF AN AREA OF MIDDLE LEVEL WAA
BEFORE THE AREA BECOMES CAPPED DURING THE AFTERNOON. MONDAY THE
REGION IS FORECAST TO BE WELL INTO THE WARM SECTOR WITH DEW
POINTS IN THE UPPER 60S AND TEMPS IN THE 80S LEADING TO
IMPRESSIVE SURFACE INSTABILITY, HOWEVER, THE LACK OF A CLEAR
FORCING MECHANISM LEADS TO LOW CONFIDENCE IN CONVECTIVE
EVOLUTION MONDAY. AT THIS POINT THE TIMEFRAME WITH THE MOST
AREAL COVERAGE OF STORMS IS LATE TUESDAY AS A WELL DEFINED COLD
FRONT IS FORECAST TO SWING ACROSS THE FORECAST AREA.
KAISER
AVIATION /00Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 651 PM CDT THU MAY 14 2026
KEY AVIATION FORECAST MESSAGES:
- PERIOD OF VFR -SHRA POSSIBLE LATE TONIGHT INTO EARLY FRI AM
(30% CHANCE)
- GUSTY SSW WINDS DEVELOP FRI AM WITH ~25 KT GUSTS THROUGH
SUNSET
WINDS WILL SETTLE INTO A SE TO SSE DIRECTION ACROSS THE AREA
THIS EVENING AROUND 5-10 KT WITH INCREASING HIGH CLOUD COVERAGE
EXPECTED AHEAD OF AN APPROACHING DISTURBANCE. AN ASSOCIATED
AXIS OF SHOWERS AND ISOLATED THUNDERSTORMS IS FORECAST TO
DEVELOP ACROSS IOWA LATE THIS EVENING AND MOVE TOWARD THE
REGION OVERNIGHT. WHILE LIGHTNING IS NOT EXPECTED HERE LOCALLY,
A FEW LINGERING SHOWERS FROM THIS ACTIVITY MAY PERSIST INTO THE
AREA LATE TONIGHT INTO EARLY FRIDAY MORNING. HAVE INTRODUCED
PROB30 GROUPS FOR LIGHT SHOWERS (VFR) TO ACCOUNT FOR THIS AS IT
MOVES FROM WEST TO EAST ACROSS THE AREA.
THE SSE WINDS WILL THEN VEER SSW IN THE WAKE OF THE SHOWERS AND
BECOME GUSTY (~25 KT) THROUGH THE REMAINDER OF THE MORNING AND
AFTERNOON HOURS BEFORE EASING WITH SUNSET.
PETR
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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