722
FXUS63 KDVN 220542
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1242 AM CDT TUE APR 22 2025
KEY MESSAGES
- CHANCE FOR A FEW STORMS LATE TONIGHT INTO EARLY TUE MORNING ESPECIALLY
NORTH OF THE HWY 30 CORRIDOR...SMALL HAIL POSSIBLE. PATCHY
FOG POSSIBLE IN RECENT RAIN AREAS?
- ACTIVE AND MILD WEATHER PATTERN ON TAP WITH PRECIP CHANCES
ALMOST EVERY DAY UNTIL THE WEEKEND, AND HIGH TEMPS IN THE 60S
AND 70S( MAINLY 70S).
- SPC HAS A MARGINAL RISK (LEVEL 1 OF 5) FOR MOST OF THE
FORECAST AREA FOR THE POTENTIAL FOR LARGE HAIL AND DAMAGING
WINDS TUESDAY INTO TUESDAY NIGHT.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 240 PM CDT MON APR 21 2025
TONIGHT...BOTH A BOUT OF SFC AND UPPER RIDGING SLIDING ACRS THE AREA
SHOULD KEEP A LID ON THINGS UNTIL WE GET ON THE BACKSIDE/LEFT FLANK
LATE TONIGHT INTO EARLY TUE MORNING. THAT'S WHEN A CONVERGENT
SOUTHWESTERLY 30 KT LLJ ELEVATED INSTABILITY POOL WITH MID LAYER
MUCAPES OF 500-1000 J/KG INDUCE ISOLATED TO SCTRD SHOWERS AND
THUNDERSTORMS MAINLY AFTER 09Z TUE AND NORTH OF I-80, AND CONTINUE
TO FESTER THROUGH MID TUE MORNING AS THEY MOVE EASTWARD. EFFECTIVE
SHEAR UP TO 35 KTS COMBINED WITH PROGGED THERMODYNAMICS SUPPORT THE
STRONGER CELLS PRODUCING AT LEAST SMALL HAIL, BUT COULD SEE A FEW
STONES NOT ALL THAT FAR OFF FROM QUARTERS. BACK TO EARLIER TONIGHT,
CURRENT WRAP AROUND CU FIELDS WILL DECAY DIURNALLY FOR A PERIOD OF
MOSTLY CLEAR SKIES TONIGHT. THIS WITH PASSING SFC RIDGE LOBE FOR
LIGHT BACKING SFC WIND REGIME MAY ALLOW FOR SOME PATCHY FOG IN
RECENT RAINFALL AREAS, BUT LOW CONFIDENCE IN THAT AND SEVERAL CAM
RUNS NOT SHOWING MUCH DEVELOPMENT IN THE DVN CWA. BUT MAY STILL GO
WITH SOME PATCHY FOG ON THE IL SIDE, BEFORE SOUTHEAST SFC WINDS
INCREASE ENOUGH TO MIX OUT ANY GROUND FOG TOWARD DAWN. LOWS TONIGHT
IN THE LOW 40S/NEAR 40 NORTHEAST, TO THE UPPER 40S SOUTHWEST.
TUESDAY...WEAK WEST-TO-EAST OR WSW-ENE QUASI-STATIONARY BOUNDARY
WILL CONTINUE TO UNDULATE SOMEWHERE ACRS SOUTHWEST INTO EASTERN IA
AND NW IL. THE MORNING CONVECTION SHOULD MOVE OFF TO THE EAST OR
DECAY SOME FOR A PARTIAL LULL FROM LATE MORNING INTO EARLY
AFTERNOON. BUT WITH STEERING FLOW BACK UPSTREAM TO THE CENTRAL
ROCKIES AND SHORT WAVE SOURCE REGION, ANOTHER APPROACHING VORT MAX
COULD INDUCE RENEWED AFTERNOON ACTIVITY ALONG THE FRONT OR MOST
ANYWHERE WITH NOT MUCH IN THE WAY OF CAPPING EML EVIDENT ON FCST
SOUNDINGS. BUT DO EXPECT MORE SCTRD CONVECTION TAKING OFF TO THE
NORTH OF THE MAIN LLVL SFC FRONT OR BAROCLINICITY RIBBON TUE EVENING
AS THE LLJ GETS GOING AGAIN. LATEST MODEL RUNS VARY ON HOW FAR NORTH
OR SOUTH THIS THERMAL GRADIENT FOCAL POINT WILL LAY OUT, WITH MORE
RECENT RUNS FAVORING THE CENTRAL INTO SOUTHERN CWA/I-80 AND SOUTH
ESPECIALLY OF EARLIER IN THE DAY ACTIVITY LINGERS LONGER AND RETARDS
FRONTAL RETREAT PROGRESSION. WILL HAVE TO HAVE 30-60+ POPS IN
VARYING LOCATIONS TO COVER THE POSSIBILITIES UNTIL BOUNDARY/
BAROCLINICITY ZONES ARE BETTER DEFINED.
EFFECTIVE SHEAR OF 35-40 KTS AND SOMEWHAT BETTER MID LAYER
LAPSE RATES OF AROUND 7 C/KM SUGGEST THE MARGINAL RISK FOR LARGE
HAIL AND ISOLATED DOWNBURST WINDS STILL LOOKS ON TARGET FOR
SOMEWHAT ELEVATED CONVECTION TUE AFTERNOON AND ESPECIALLY THE
EVENING AND OVERNIGHT ACTIVITY. A PRECIPITAL WATER FEED(PWATS)
OF 1 TO 1.2 INCHES SUPPORT LOCALLY HEAVY RAINFALL OF 0.50 TO
AROUND AN INCH IN AREAS THAT MANAGE TO GET SOME STORMS. OF
COURSE THERE IS A CHANCE FOR FEW HIGHER SWATHS IF A FEW STORM
CLUSTERS DEVELOP AND TRAIN/BACK-BUILD ALONG THE FRONT.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
ISSUED AT 240 PM CDT MON APR 21 2025
WEDNESDAY AND THURSDAY...CONTINUED PATTERN WITH THE LOCAL AREA UNDER
WEST-SOUTHWEST STEERING FLOW AROUND BROAD LOW AMPLITUDE SOUTHEASTERN
CONUS UPPER RIDGE. VERTICAL FLOW AND SHEAR PROFILES LOOK WEAKER ON
WED, BUT WITH A ONGOING QUASI-STATIONARY SFC FRONT ALIGNED WITH THE
HIGHER LEVEL FLOW AND STILL TRYING TO RETREAT NORTH, WILL HAVE TO
KEEP POPS FOR MORE SHOWERS AND THUNDERSTORMS. CURRENT ENSEMBLE WAVE
TIMING HAS A RIDGE-RIDING VORT MAX PROPAGATING ACRS THE AREA LATE THU
NIGHT INTO FRIDAY MORNING WITH A POTENTIAL MORE ORGANIZED STORM
CLUSTER DEVELOPMENT ACRS THE AREA AT THAT TIME. BEFORE THE WAVE'S
ARRIVAL, A POTENTAIL INCREASED RETURN FLOW AHEAD OF IT MAY WARM
AFTERNOON HIGHS ON THURSDAY INTO THE UPPER 70S OR NEAR 80 IN SOME
SPOTS.
FRIDAY, SATURDAY AND SUNDAY...DEPENDING ON WAVE PROGRESSION AND
TIMING, SHOWERS AND STORMS LINGERING OUT OF THU NIGHT MAY EXIT OFF
TO THE EAST BY LATE FRIDAY MORNING, BUT DIFFICULT TO NAIL DOWN THIS
TYPE OF DETAIL WITH THIS PATTERN AT THIS TIME. WHATEVER WAVE CAN
PROGRESS ACRS AND EAST OF THE REGION BY LATE WEEK, WILL OPEN UP THE
AREA TO BOTH SFC AND UPPER RIDGING FOR A DRY BUT COOLER SATURDAY
GENERALLY IN THE 60S. AS WE GET ON THE OTHER SIDE OF THE
PROGRESSING RIDGE AXIS, ELEVATED RETURN FLOW MAY SPAWN MORE SHOWERS
AND STORMS BY SUNDAY NIGHT.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1238 AM CDT TUE APR 22 2025
AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD MOVE ACROSS
LOCATIONS NORTH OF I-80 THIS MORNING, THEN ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS ROUGHLY THE I-80 CORRIDOR THIS
AFTERNOON BASED ON MODEL TRENDS. MVFR CONDITIONS ARE POSSIBLE WITH THE
STRONGER STORMS.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...12
LONG TERM...12
AVIATION...HAASE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page