788
FXUS63 KDVN 240803
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
303 AM CDT THU APR 24 2025
KEY MESSAGES
- SHOWERS AND STORMS WILL ONCE AGAIN LINGER INTO THE EARLY MORNING
HOURS TODAY.
- ONE MORE SLOW MOVING ROUND OF SHOWERS AND STORMS ARE EXPECTED
FROM TONIGHT THROUGH FRIDAY MORNING. SEVERE STORMS ARE NOT
ANTICIPATED.
- SEVERE STORMS ARE POSSIBLE EARLY NEXT WEEK.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 302 AM CDT THU APR 24 2025
SIMILAR TO THE PAST FEW MORNINGS, THE OVERNIGHT SHOWERS AND
THUNDERSTORMS ARE IN A WEAKENING STAGE AND MOVING WELL EAST OF THE
INITIATION POINT AS OF 2 AM. OUTFLOW FROM THE STORMS IN CENTRAL IOWA
HAVE PUSHED THE CONVERGENCE FROM THE STATIONARY FRONT A BIT SOUTH,
NOW IN SOUTH CENTRAL IOWA THROUGH NORTHERN ILLINOIS. THIS IS ONLY
THE SURFACE BOUNDARY, AS THE FRONT ALOFT REMAINS IN NORTHERN IOWA
INTO SOUTHERN WISCONSIN. THE MAIN ACTION ALONG THE FRONT TODAY
APPEARS TO BE SETTING UP NORTH AND WELL WEST, WELL, AFTER THE
EVOLUTION OF THE FESTERING ACTIVITY ON THE NORTHEAST NOSE OF THE
WEAK LLJ, WHICH IS AIMED INTO OUR NORTHERN CWA, AND SHOULD AT LEAST
OFFER SCATTERED SHOWERS AND WEAK STORMS IN THE NORTHERN 1-2 COUNTIES
THROUGH SUNRISE, SOMETHING MODELS DON'T HANDLE WELL, BUT HAS BEEN
THE CASE THE LAST 2 MORNINGS.
AFTER THIS ACTIVITY DECAYS COMPLETELY, TODAY WILL SEE THE FRONT LIFT
NORTH, RESULTING IN A WARM, BUT NOT OVERLY HUMID DAY. DEW POINT
VALUES LOOK TO REMAIN IN THE 50S AS WE LACK FRONTAL CONVERGENCE TO
SEE HIGHER VALUES. HIGHS IN THE MID 70S NORTH TO LOWER 80S CENTRAL
AND SOUTH ARE EXPECTED, WITH DRY WEATHER HOLDING IN NEARLY THE
ENTIRE AREA THROUGH MID AFTERNOON. BY LATE AFTERNOON, THE
APPROACHING COLD FRONT AND MID LEVEL SHORT WAVE IS EXPECTED TO
INITIATE STORMS OVER WESTERN AND CENTRAL IOWA, WHICH COULD QUICKLY
EVOLVE EAST/NORTHEAST, REACHING OUR WESTERN COUNTIES IN THE 5 -7 PM
TIME FRAME. WITHOUT MUCH SHEAR AND STRONG FORCING TODAY, ONLY AN
ISOLATED DOWNBURST OR HAIL SEEMS THE THREAT, AND THAT'S MAINLY WEST
OF OUR AREA.
TONIGHT, STORMS WILL GRADUALLY SHIFT EAST, WITH SUPPORT FROM THE MID
LEVEL SHORT WAVE AND SLOWLY ADVANCING COLD FRONT. THIS FRONT IS NOT
EXPECTED TO ARRIVE IN OUR AREA UNTIL LATE TONIGHT, AND EXIT OUR AREA
BY LATE FRIDAY MORNING, WHICH PROBABLY MEANS THE CONVECTION WILL
DECAY BEFORE MOVING THROUGH THE AREA TONIGHT. THIS HAS RESULTED IN A
LOWERED POPS (30-40%) IN THE EASTERN CWA, WHILE WESTERN AREAS REMAIN
~80-90%.
FRIDAY MORNING, THE FRONT WILL SLOWLY WORK THROUGH THE AREA, WITH
POPS REMAINS IN THE 50-70% RANGE THROUGH THE MORNING, BEFORE
DROPPING CONSIDERABLY EARLY IN THE AFTERNOON, AND DRY BY LATE DAY.
QPF FROM TONIGHT THROUGH FRIDAY APPEARS TO BE 0.5 TO 1.0 INCH WEST,
TO UNDER 0.25 IN THE EAST. THE SLOW MOVEMENT OF STORMS MAY ALLOW FOR
ISOLATED HEAVY RAINFALL AMOUNTS IN OUR WESTERN AREAS FROM LATE
AFTERNOON THROUGH THIS EVENING.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
ISSUED AT 302 AM CDT THU APR 24 2025
PLEASANT, COOLER AIR IS ON THE WAY FOR FRIDAY NIGHT THROUGH SUNDAY,
AS HIGH PRESSURE MOVES INTO THE REGION, ALLOWING FOR LOWS TO DROP TO
THE UPPER 30S TO MID 40S AGAIN, WITH HIGHS IN THE 60S TO LOW 70S
THIS WEEKEND.
SUNDAY AFTERNOON, LOW OPS REMAIN IN THE BLENDED FORECAST, BUT WITH
LITTLE BOUNDARY LAYER MOISTURE, THE MOISTURE TRANSPORT ALOFT
SHOULDN'T REALLY ARRIVE UNTIL AFTER DARK, AND THAT APPEARS
AIMED INTO MN FOR NOW. OVERNIGHT INTO MONDAY MORNING, SOME
ELEVATED SHOWERS AND STORMS APPEAR MORE LIKELY, WITH BOTH
MOISTURE TRANSPORT BEGINNING TO AIM INTO OUR AREA, AND
CONCEPTUAL CONVECTIVE EVOLUTION SUPPORTS THE MN ACTIVITY
DROPPING SOUTHEAST BY MORNING TOO.
THE CONVECTIVE EVOLUTION INTO EARLY WEEK IS NO LONGER AS
CONSISTENTLY FORECAST BY MODELS INTO TUESDAY, WITH BOTH FRONTAL
PLACEMENT GREATLY VARIED, AS WELL AS THE UPPER TROF POSITION. FOR
NOW, THE 00Z GFS AND EC SHOW LESS PHASING OF THE NORTHERN ROCKIES
AND SOUTHERN ROCKIES TROF MONDAY. WE WILL WAIT FOR SPC'S EXTENDED
OUTLOOK BEFORE ADDRESSING THIS FARTHER. BUT A RISK WILL NEED TO BE
WATCHED IN THIS PERIOD, AS STRONGER WINDS ALOFT ARE FORECAST WITH
THIS FRONTAL PASSAGE, THAN THE STORMS IN THE PAST FEW DAYS.
WARM WEATHER CAN BE EXPECTED AHEAD OF THIS FRONTAL SYSTEM, MONDAY
AND TUESDAY, WITH HIGHS IN THE 70S AND 80S, FOLLOWED BY COOLER
WEATHER IN THE 60S FOR WEDNESDAY.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1234 AM CDT THU APR 24 2025
A FRONTAL BOUNDARY EXTENDS FROM SOUTH OF DBQ TO VTI WHERE IT
INTERSECTS AN EASTWARD PROGRESSING OUTFLOW AND COOL POOL
FROM EARLIER SEVERE CONVECTION IN NORTH-CENTRAL IOWA.
FORCING FROM BOTH WILL MAINTAIN SOME POTENTIAL FOR SHRA/TSRA
OVERNIGHT AT CID AND DBQ PARTICULARLY WHERE PROB30 MENTION WAS
INCLUDED THROUGH 09Z-11Z. THEREAFTER, I CAN'T RULE OUT SOME
PRECIPITATION POTENTIAL AT TIMES THE REST OF THE PERIOD AT
ALL SITES BUT CONFIDENCE IS TOO LOW FOR MENTION THIS FAR OUT AND
WILL NEED TO MONITOR MESOANALYSIS TO DEFINE POSSIBLE CORRIDORS
AND TIMING OF BETTER CHANCES IN SUBSEQUENT TAF ISSUANCES.
THERE IS ALSO SOME CHANCE FOR A PERIOD OF MVFR CEILINGS IN
PARTICULAR AT DBQ NORTH OF THE SAGGING FRONTAL ZONE, BUT THIS
TOO IS OF LOW CONFIDENCE AND THEREFORE HAVE KEPT ALL SITES VFR.
WINDS WILL BE A CHALLENGE AS WELL WITH THE FRONT AND OUTFLOW.
THIS WILL LIKELY BRING A NORTHERLY COMPONENT TO CID AND DBQ
FOR A TIME OVERNIGHT WITH A CHANCE FOR LOCALIZED GUSTINESS
TO 20 KTS, THEN SHIFTING MORE EASTERLY BY MORNING BEFORE LIGHT
AND VARIABLE THEREAFTER AS FLOW TURNS WEAK. MLI AND BRL WILL BE
VARIABLE TO SOUTHERLY OVERNIGHT TURNING MORE EASTERLY FOR A
TIME THURSDAY, BUT GENERALLY LIGHT THROUGHOUT.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...ERVIN
LONG TERM...ERVIN
AVIATION...MCCLURE
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