586
FXUS63 KDVN 291750
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1250 PM CDT SAT MAR 29 2025
KEY MESSAGES
- AN ACTIVE WEEKEND IS ON TAP, WITH OCCASIONAL CHANCES OF
SHOWERS AND STORMS (60-90%) TONIGHT THROUGH SUNDAY, WITH A
LEVEL 1 AND 2 OUT OF 5 RISK FOR SEVERE WEATHER. DAMAGING WINDS
AND LARGE HAIL ARE THE MAIN THREATS.
- TEMPERATURES WILL START OFF WARM TODAY, TURNING COOLER SUNDAY AND
MONDAY
- A BRIEF RESPITE IN SHOWERS AND STORMS IS EXPECTED MONDAY AND
MOST OF TUESDAY BEFORE A LARGE SYSTEM MOVES IN FOR MID-WEEK
NEXT WEEK, WITH ANOTHER CHANCE OF STRONG TO SEVERE STORMS
WEDNESDAY
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 419 AM CDT SAT MAR 29 2025
LARGELY DRY CONDITIONS ARE EXPECTED TODAY THROUGH THIS AFTERNOON AS
WE REMAIN BETWEEN SYSTEMS, ALTHOUGH THERE WILL BE MORE CLOUD COVER
TODAY COMPARED TO YESTERDAY. WE REMAIN ON THE SOUTHERN EDGE OF A
WEAK AREA OF LOW PRESSURE, CURRENTLY SITUATED OVER NORTHEAST
IA/SOUTHEAST MN. THIS AREA OF LOW PRESSURE IS ACCOMPANIED BY A
SURFACE COLD FRONT, WHICH IS SLOWLY SAGGING SOUTHWARD EARLY THIS
MORNING. SOUTHERLY FLOW REMAINS IN OUR AREA, WHICH SHOULD HELP KEEP
TEMPERATURES NEARLY 15 TO 20 DEGREES ABOVE AVERAGE FOR TODAY AS
HIGHS WARM TO THE LOWER 70S FOR MOST OF THE AREA.
MOISTURE SHOULD INCREASE TONIGHT INTO SUNDAY AS A NEGATIVELY-TILTED
UPPER-LEVEL TROUGH AND ASSOCIATED SURFACE LOW APPROACHES THE REGION,
LEADING TO LIKELY CHANCES (50-80+%) OF SHOWERS AND STORMS LATE
TONIGHT. PWAT VALUES BETWEEN 1 TO 1.4 INCHES ARE EXPECTED TONIGHT,
WHICH ARE ABOVE THE 90TH PERCENTILE ON THE ECMWF PWAT CLIMATOLOGICAL
PERCENTILES, SO A WETTING RAINFALL IS LIKELY WITH ANY ACTIVITY THAT
DEVELOPS. MOST-UNSTABLE CAPE VALUES ARE PROGGED AROUND 500-1000+
J/KG PER THE 29.00Z HREF ENSEMBLE MEAN, ALONG WITH SOME DECENT DEEP-
LAYER SHEAR ON THE ORDER OF 30-40 KNOTS. SOUNDINGS SUGGEST
CONVECTION SHOULD STRUGGLE TO BECOME SURFACE-BASED, IN FAVOR OF MORE
ELEVATED CONVECTION. WITH MODEST MID-LEVEL LAPSE RATES AROUND 6-7
DEGREE C/KM, THIS WOULD SUGGEST STRONG WINDS AND LARGE HAIL AS THE
MAIN THREATS. AS SUCH, SPC CONTINUES TO KEEP THE WESTERN HALF OF THE
FORECAST AREA IN A MARGINAL RISK (LEVEL 1 OF 5) OF STRONG TO SEVERE
STORMS THROUGH 12Z/7 AM SUNDAY MORNING. HOWEVER, THAT'S NOT ALL FOR
OUR SEVERE WEATHER THREAT THIS WEEKEND - MORE ON THAT IN THE LONG
TERM SECTION.
LONG TERM /SUNDAY THROUGH FRIDAY/
ISSUED AT 419 AM CDT SAT MAR 29 2025
AS WE GO THROUGH THE DAY SUNDAY, THE AREA OF LOW PRESSURE WILL
FINALLY ARRIVE, WITH A POTENT MID-LEVEL IMPULSE ON THE SOUTHERN
SIDE OF THE SURFACE LOW MOVING THROUGH OUR AREA. THIS WILL HELP
MAINTAIN LIKELY CHANCES (60-90%) OF SHOWERS AND STORMS IN OUR
AREA SUNDAY MORNING. HOWEVER, AS THE LOW PRESSURE SYSTEM PASSES
THROUGH THE AREA, THE LINGERING COLD FRONT/BAROCLINIC ZONE WILL
FINALLY TRANSLATE SOUTHEASTWARD, WHICH SHOULD LEAD TO
TEMPERATURES CRASHING FROM NORTHWEST TO SOUTHEAST SUNDAY. SOME
LOCATIONS OVER OUR WEST COULD SEE THEIR DAYTIME HIGH
TEMPERATURES IN THE MORNING, MAKING FOR A CHALLENGING
TEMPERATURE FORECAST SUNDAY. AS FAR AS THE STORMS ARE CONCERNED,
THE LATEST SUITE OF CAM GUIDANCE STRONGLY SUGGESTS THAT THE
MORNING WILL BE MORE ACTIVE THAN THE AFTERNOON, SO WE WILL HAVE
TO WATCH FOR ROBUST CONVECTION IN THE MORNING. SPC HAS KEPT THE
SEVERE WEATHER RISK FOR SUNDAY UNCHANGED, WITH A SLIGHT RISK
(LEVEL 2/5) ACROSS OUR SOUTH, WITH A MARGINAL RISK (LEVEL 1/5)
FOR MOST OF THE REMAINDER OF THE AREA. THE LION'S SHARE OF THE
SEVERE WEATHER ON SUNDAY LOOKS TO REMAIN TO OUR SOUTHEAST WHERE
AN ENHANCED RISK (LEVEL 3/5) CONTINUES TO BE. THE COLD FRONT
WILL HAVE ALREADY PASSED US BY PEAK HEATING OF THE DAY, SO MORE
ADVANTAGEOUS FOR SEVERE WEATHER SOUTHEAST OF OUR AREA. AGAIN,
THE MAIN THREATS WITH ANY STRONG TO SEVERE STORMS ON SUNDAY WILL
BE STRONG WINDS AND LARGE HAIL. WITH STRONG COLD AIR ADVECTION
SURGING INTO THE AREA, THERE COULD ACTUALLY BE SOME LIGHT WINTRY
PRECIPITATION ON THE BACKSIDE OF THE SYSTEM CLOSER TO A
DEFORMATION ZONE. SOME LIGHT SNOW OR EVEN SLEET WILL BE POSSIBLE
SUNDAY NIGHT, BUT ANY ACCUMULATIONS SHOULD REMAIN VERY LIMITED.
SUNDAY NIGHT LOWS SHOULD FALL TO THE UPPER 20S TO LOWER 30S,
WHICH WOULD BE A NEARLY 30 DEGREE DROP FROM THE HIGH
TEMPERATURES.
MUCH CALMER AND COOLER CONDITIONS ARE EXPECTED MONDAY AND MONDAY
NIGHT AS AN AREA OF HIGH PRESSURE BUILDS ACROSS THE CENTRAL CONUS,
WITH MORE SEASONAL TEMPERATURES FOR DAYTIME HIGHS (IN THE UPPER 40S
NORTH TO THE LOWER 50S SOUTH). CONDITIONS SHOULD BECOME MORE ACTIVE
BY MID-WEEK AS LONGWAVE TROUGH DEEPENS OVER THE WESTERN CONUS ON
TUESDAY. A 140+ KT UPPER-LEVEL JET IS PROGGED TO NOSE INTO MIDWEST,
BECOMING MORE NEGATIVELY-TILTED WITH TIME. LREF CLUSTER ANALYSIS
FROM THE GEFS, EPS, AND GEFS ENSEMBLES DO SHOW SOME UNCERTAINTY ON
JUST HOW AMPLIFIED THIS TROUGH WILL BECOME, WITH THE GEFS AND ITS
DETERMINISTIC COUNTERPART MORE SHALLOW WITH THE AMPLITUDE OF THE
WAVE, WITH THE EPS AND GEFS MORE AMPLIFIED. THESE SOLUTIONS WOULD
PLACE US CLOSER TO THE ASSOCIATED SURFACE LOW. THIS LOW PRESSURE
SYSTEM DOES APPEAR RATHER POTENT, WITH MSLP VALUES AT LEAST TWO
STANDARD DEVIATIONS BELOW THE MEAN PER THE ECWMF MSLP STANDARDIZED
ANOMALIES. ANOTHER DAY OF ACTIVE WEATHER IS POSSIBLE ON WEDNESDAY,
AS THE ECMWF EFI CAPE-SHEAR VALUES RANGE BETWEEN 0.6 TO 0.8,
INDICATING A NOTABLE SEVERE WEATHER ENVIRONMENT. ADDITIONALLY, THE
CSU-MLP ALSO INDICATE THE POTENTIAL FOR STRONG TO SEVERE STORMS,
ALONG WITH INCREASING THETA-E, WITH HIGH TEMPERATURES LIKELY TO WARM
BACK UP TO THE UPPER 60S TO LOWER 70S PER THE NBM. SPC CONTINUES TO
KEEP OUR SOUTHEASTERN HALF IN A SLIGHT RISK FOR WEDNESDAY, SO WE
WILL NEED TO CONTINUE KEEPING AN EYE ON THIS SYSTEM AS WE APPROACH
MID-WEEK NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1243 PM CDT SAT MAR 29 2025
FRONTAL BOUNDARY INTO EASTERN IOWA WILL STALL AND REMAIN NEARLY
STATIONARY UNTIL ABOUT 12Z/30 WHEN IT WILL BEGIN MOVING EAST.
WIND ALOFT INCREASE OVERNIGHT WHICH WILL BRING 20-40% COVERAGE
OF SHRA WITH A 10% RISK OF A TSRA. GIVEN THE LOW RISK, TSRA WAS
NOT INCLUDED IN THE 18Z TAFS. THERE IS A MARGINAL LLWS RISK IN
SOUTHEAST IOWA INTO WESTERN ILLINOIS WIDESPREAD MVFR WITH
POCKETS OF IFR TO DEVELOP BY 12Z/30 ACROSS EASTERN IOWA AND
NORTHERN ILLINOIS. AFTER 14Z/30 NEW SHRA/TSRA WILL DEVELOP WITH
BETTER COVERAGE ALONG/EAST OF THE MISSISSIPPI RIVER.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...SCHULTZ
LONG TERM...SCHULTZ
AVIATION...08
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