612
FXUS63 KDVN 251122
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
622 AM CDT THU JUN 25 2026
KEY MESSAGES
- A PATTERN CHANGE THIS WEEKEND WILL BRING HEAT AND HIGH
HUMIDITY TO THE AREA AND PERSIST INTO NEXT WEEK. THE
PROBABILITY OF HEAT HEADLINES CONTINUES TO INCREASE (50-70%
CHANCE).
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 145 AM CDT THU JUN 25 2026
A DRY THURSDAY AHEAD AS THE COLD FRONT CLEARS THE AREA BY SUNRISE
AND DEW POINTS FALL A FEW DEGREES, MAKING TODAY COMPARABLE TO
TUESDAY. SCATTERED LOW LEVEL CLOUDS WILL DEVELOP AS SURFACE
TROUGHING LINGERS ACROSS EASTERN IOWA AND NORTHWEST ILLINOIS. OUR
ATTENTION SHIFTS TO THE NEXT MID-LEVEL SHORTWAVE EJECTING INTO THE
CENTRAL PLAINS THOUGH. SURFACE CYCLOGENESIS IS FORECASTED TO OCCUR
OVER NORTHERN TEXAS AS THE COLD FRONT FROM WEDNESDAY STALLS OUT
ACROSS CENTRAL MISSOURI AND SOME CIRRUS START TO INTRUDE INTO THE
SOUTHERN CWA.
HEADING INTO THURSDAY NIGHT, OUR LIGHT WINDS ARE EXPECTED TO SHIFT
SLOWLY FROM NORTHWESTERLY TO EASTERLY AS THE LOW PRESSURE OVER THE
SOUTHERN PLAINS MOVES INTO SOUTHERN KANSAS, ESSENTIALLY ALONG THE
STATIONARY FRONT. LOWS DROP BACK INTO THE UPPER 50S TO MID 60S, BUT
CLOUD COVER COULD HAMPER RADIATIONAL COOLING, ESPECIALLY SOUTH OF
INTERSTATE 80. LIGHT SHOWERS MAY ALSO START TO DEVELOP SOUTH OF
HIGHWAY 34 ALONG A MID-LEVEL F-GEN BAND AND ISENTROPIC UPGLIDE
IN THE LOW LEVELS. THE MAGNITUDE OF DRY AIR ADVECTION DURING THE
DAY ON THURSDAY WILL DETERMINE IF THE ONSET OF PRECIPITATION IS
DELAYED TO FRIDAY MORNING.
BY FRIDAY, THE LOW PRESSURE PROPAGATES INTO NORTH-CENTRAL MISSOURI,
CONVERTING THE STATIONARY FRONT INTO WARM FRONT INCHING
NORTHWARD. THE MID-LEVEL TROUGH SUPPORTING THIS SYSTEM ALSO
MOVES INTO NORTHERN MISSOURI, BUT THE LACK OF CURVATURE IN THE
FLOW LIMITS THE 500 MB VORTICITY TO PURELY SHEAR-DRIVEN. THIS IS
GOOD NEWS FOR MOST OF THE CWA NORTH OF INTERSTATE 80 AS THE
MAIN SOURCE OF LIFT BEING DISPLACED SO FAR TO THE SOUTH MEANS
THEY WILL LIKELY (80-90%) HAVE A DRY FRIDAY WHILE AREAS SOUTH
WILL HAVE STRATIFORM RAINFALL SIMILAR TO SUNDAY. THE 24.18Z REFS
RUN HAS ACCUMULATIONS RELATIVELY LIGHT ALONG AND SOUTH OF
INTERSTATE 80 WITH A 20-40% CHANCE OF GREATER THAN A QUARTER OF
AN INCH SOUTH OF HIGHWAY 34. THEREFORE, THE THREAT OF EXCESSIVE
RAINFALL WITH THIS SYSTEM IS LOW.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
ISSUED AT 145 AM CDT THU JUN 25 2026
FRIDAY NIGHT-SUNDAY...CONDITIONS DRY OUT HEADING INTO FRIDAY NIGHT
AS THE LOW PRESSURE OVER MISSOURI WEAKENS SIGNIFICANTLY FROM THE
LACK OF MID-TO-UPPER-LEVEL DYNAMICAL SUPPORT AND THE WARM FRONT ONCE
AGAIN CONVERTS TO A STATIONARY FRONT. A GREAT LAKES HIGH PRESSURE IS
EXPECTED TO KEEP WINDS EASTERLY NORTH OF THIS STATIONARY BOUNDARY
WITH SOME LINGERING SHOWERS POSSIBLE INTO SATURDAY. OUR ATTENTION
ONCE AGAIN SHIFTS OUT WEST WHERE A SEASONABLY STRONG LOW
HEIGHTS CENTER WILL DIG INTO THE WESTERN CONUS, ENABLING A
LONGWAVE RIDGE TO BUILD AHEAD OF IT ACROSS THE GREAT PLAINS.
THIS KICKS OFF A WARMING AND MOISTENING TREND SATURDAY NIGHT
WHEN PRESSURE FALLS ALONG THE CENTRAL AND NORTHERN ROCKIES TURN
THE LOW-LEVEL FLOW OUT OF THE SOUTH, FORCING THE STATIONARY
FRONT TO TRANSITION INTO A WARM FRONT (AGAIN!) AND MOVE
NORTHWARD INTO OUR CWA. ISOLATED (20-40%) POPS ARE CURRENTLY
FORECASTED ALONG THIS BOUNDARY SATURDAY NIGHT INTO SUNDAY
MORNING. IN TERMS OF SEVERE WEATHER, THAT REMAINS UNCERTAIN. THE
24.12Z LREF RUN HAS A 60-80% JOINT PROBABILITY OF MUCAPE VALUES
EXCEEDING 500 J/KG AND SFC-TO-500 MB BULK SHEAR EXCEEDING 30
KNOTS ALONG THE FRONT, BUT WITH RIDGING BUILDING OVERHEAD,
CONVECTIVE INITIATION SHOULD STRUGGLE TO OCCUR. ONCE THE WARM
FRONT CLEARS THE AREA FROM SOUTH TO NORTH, DEW POINTS SOAR INTO
THE MID-TO-UPPER 70S (60-80% CHANCE PER THE 24.12Z LREF RUN),
SETTING THE STAGE FOR POTENTIAL EXCESSIVE HEAT EARLY NEXT WEEK.
MONDAY-WEDNESDAY...WITH THE WARM SECTOR FULLY IN PLACE, MONDAY
APPEARS TO THE DAY WITH THE GREATEST CHANCE AT SEEING HEAT HEADLINES
WITH THE 24.12Z LREF RUN HAVING A 50-70% CHANCE (10% HIGHER COMPARED
TO YESTERDAY) OF HEAT INDICES EXCEEDING 100 DEGREES. BY TUESDAY, A
SHORTWAVE EMBEDDED IN THE LONGWAVE TROUGH, NOW OVER THE ROCKIES,
LIFTS NORTHWARD INTO CENTRAL CANADA, REORIENTING THE RIDGE OVER MUCH
OF THE EASTERN CONUS AND INTRODUCING SOUTHWESTERLY FLOW ALOFT OVER
IOWA. THIS WILL OPEN THE DOOR FOR SUBTLE SHORTWAVE PASSAGES AND
INCREASING POPS SLIGHTLY TUESDAY NIGHT AND WEDNESDAY. THE WEAKENING
OF THE NORTHWESTERN EDGE OF THE HEAT DOME COULD PROVIDE A COUPLE
DEGREES OF RELIEF, BUT HEAT HEADLINES REMAIN POSSIBLE (40-60%).
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 620 AM CDT THU JUN 25 2026
ASIDE FROM SOME PATCHY SHALLOW MVFR/IFR FOG AT CID AND BRL
EARLY THIS MORNING, VFR WILL PREVAIL INTO TONIGHT WITH AN AREA
OF HIGH PRESSURE REMAINING ANCHORED OVER THE GREAT LAKES REGION.
RAIN CHANCES WILL INCREASE AT BRL LATE TONIGHT AS THE NEXT
STORM SYSTEM APPROACHES FROM THE SOUTHWEST, WHICH COULD RESULT
IN A PERIOD OF MVFR CEILINGS AND VISIBILITIES.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...DELAUNE
LONG TERM...DELAUNE
AVIATION...UTTECH
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