514
FXUS63 KDVN 200546
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1246 AM CDT TUE MAY 20 2025
KEY MESSAGES
- WET WEATHER WILL BECOME MORE CONTINUOUS TONIGHT AS THE MAIN SYNOPTIC
LOW PRESSURE MOVES NORTHEAST, RESULTING IN RAINFALL OF 1-2
INCHES IN MOST LOCATIONS.
- WINDY CONDITIONS WILL CONTINUE THROUGH TUESDAY MORNING, WITH
EAST WINDS 20 TO 30 MPH, GUSTING TO 35-40, AND A FEW GUSTS TO
AROUND 45 MPH POSSIBLE.
- CONDITIONAL SEVERE WEATHER THREAT (LEVEL 1/2 OUT OF 5)
MODULATED BY THE LOCATION OF A WARM FRONT TONIGHT AND
TOMORROW, WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY
THREATS TONIGHT. TOMORROW (LVL 1), DAMAGING WINDS AND
ISOLATED TORNADOES ARE POSSIBLE.
- A SHARP TEMPERATURE GRADIENT IS EXPECTED, ESPECIALLY NEAR INTERSTATE
80, WITH COOL CONDITIONS NORTH, AND MILDER AIR TO THE SOUTH
THROUGH TUESDAY, FOLLOWED BY WIDESPREAD COOL WEATHER
WEDNESDAY.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 156 PM CDT MON MAY 19 2025
THE CHALLENGING FORECAST OF A TIGHT TEMPERATURE GRADIENT OVER THE
AREA ARE IN PLAY TODAY, AS RAIN COOLED EAST WINDS HAVE HELD
TEMPERATURES TO THE LOWER 50S SO FAR IN MUCH OF THE CWA, WHILE THE
SOUTH IS ONLY IN THE UPPER 50S AS OF 1 PM. DESPITE RAINFALL THROUGH
NOON OF ONLY AROUND 0.25 OR LESS ON AVERAGE IN THE SOUTH, THIS HAS
WETBULB TEMPERATURES DOWN QUITE A BIT BELOW GUIDANCE, AND
RECOVERY IN TEMPERATURES WILL REQUIRE A SUSTAINED DRY PERIOD
WITH SOME SUN, AND THAT'S NOT GOING TO HAPPEN IN ALL LOCATIONS
FOR SURE.
TONIGHT, WE EXPECT WIDESPREAD RAINFALL AND SOME HEAVY RAIN RATES.
THE MAIN SYNOPTIC LOW PRESSURE WILL MOVE TOWARDS IOWA TONIGHT,
INTENSIFYING WARM ADVECTION OVER THE COOL AIR, AND BRINGING
WIDESPREAD RAIN AND THUNDERSTORMS. WHILE MODELS ARE VARIED GREATLY
ON QPF PLACEMENT, THE POTENTIAL FOR RAINFALL REMAINS NEARLY 100% IN
ALL LOCATIONS TONIGHT THROUGH TUESDAY NOON. LOW PRESSURE WILL
CONTINUE TO DEEPEN TONIGHT AS IT MOVES EAST TOWARDS IOWA, RESULTING
IN STRONG FORCING, AND A PERIOD OF WINDS NEAR ADVISORY LEVEL,
ESPECIALLY IN THE NORTH 1/2 OF THE CWA. RAINFALL TONIGHT THROUGH
TUESDAY MORNING OF 1-2 INCHES REMAINS ON TRACK, WITH SOME ISOLATED
HIGHER AMOUNTS POSSIBLE.
BY TUESDAY MORNING, THE LOW PRESSURE IS EXPECTED TO BE OCCLUDING AND
BEGINNING TO FILL. WINDS ARE EXPECTED TO DECREASE, WITH A LULL NEAR
INTERSTATE 80 WHERE CONVERGENCE ALONG THE FRONT MAY RESULT IN LIGHT
WINDS, FOG, AND SLOW MOVING SHOWERS AND STORMS THROUGH TUESDAY
AFTERNOON. IF WE DID SEE HEATING, WEAK TORNADOES MIGHT BE A
POSSIBILITY ALONG THE FRONT, AND WE'LL NEED TO KEEP ANY EYE ON THAT
POTENTIAL, CURRENTLY ASSOCIATED WITH A LEVEL 1 OF 5, MARGINAL RISK
FROM SPC DAY 2. IN ADDITION, THE SLOWER MOVING CONVECTION FOSTERING
A LIKELIHOOD OF NARROW CORRIDORS OF ADDITIONAL HEAVY RAIN. FALLING
ON ALREADY WET GROUND THIS WOULD NEED TO BE WATCHED FOR A RISK OF
LOCALIZED FLASH FLOODING.
TUESDAY REMAINS A CHALLENGE REGARDING TEMPERATURES, WITH THE
FRONT BISECTING THE AREA, 50S NORTH HALF TO 70S SOUTH HALF
APPEAR ON TARGET, AND THAT'S HARD TO MESSAGE EVEN IF THAT'S
PERFECT.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
ISSUED AT 156 PM CDT MON MAY 19 2025
BY WEDNESDAY, WIDESPREAD CLOUDS AND COOL NORTHWEST WINDS SHOULD
BRING A COOL DAY FOR ALL LOCATIONS, IN THE MID 50S TO LOWER
60S. THURSDAY, HIGHS IN THE LOWER 60S ARE EXPECTED AS THE LAST
OF THE CLOUDS AND SHOWERS LINGER IN THE REGION WITH RESIDUAL
LIFT FROM THE UPPER LOW AND LOWER LEVEL CONVERGENCE/OCCLUDED
FRONT.
THEN BY LATE WEEK WE'LL START TO DRY OUT AND SEE MODERATING
TEMPERATURES HEADING INTO THE MEMORIAL DAY HOLIDAY WEEKEND. WE'LL
SEE SOME RAIN CHANCES RETURN THOUGH OVER THE WEEKEND AHEAD OF THE
NEXT TROUGH AND ONSET OF WARM, MOIST ADVECTION.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1241 AM CDT TUE MAY 20 2025
WIDESPREAD RA WITH EMBEDDED TSRA WILL BE SEEN ACROSS EASTERN
IOWA AND NORTHERN ILLINOIS THROUGH 18Z/20. CONDITIONS WILL
SLOWLY DETERIORATE TO IFR THROUGH 13Z/20 AND WILL LIKELY REMAIN
THERE THROUGH 00Z/20. STRONG GRADIENT WINDS GUSTING UP TO 45
KNOTS ARE EXPECTED TO DEVELOP PRIOR TO 12Z/20 AND CONTINUE TO
NEAR 18Z/20 BEFORE DECAYING RESULTING IN LLWS. NEW DIURNAL
CONVECTION WILL DEVELOP AFTER 16Z/20 ACROSS EASTERN IOWA AND
NORTHERN ILLINOIS BUT WILL LIKELY BE ISOLATED TO SCATTERED.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...ERVIN
LONG TERM...ERVIN/MCCLURE
AVIATION...08
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page