293
FXUS63 KDVN 150548
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1248 AM CDT THU MAY 15 2025
KEY MESSAGES
- THERE IS A SLIGHT CHANCE (15-30%) OF ISOLATED SHOWERS AND
STORMS ACROSS NORTHERN IL THIS AFTERNOON INTO THE EARLY
EVENING. BRIEF HEAVY RAIN AND LIGHTNING ARE THE MAIN THREATS
IN THE STRONGEST CELLS.
- A CONDITIONAL THREAT FOR SEVERE STORMS (LEVEL 2 OF 5) REMAINS
THURSDAY AFTERNOON AND EARLY EVENING ACROSS NORTHWEST AND NORTH
CENTRAL IL.
- HUMID AND BREEZY CONDITIONS WITH NEAR RECORD WARMTH THURSDAY,
WITH MOST LOCATIONS HITTING 90 DEGREES OR HIGHER.
- ACTIVE WEATHER RETURNS EARLY NEXT WEEK, WITH WIDESPREAD
BENEFICIAL RAIN POSSIBLE.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 220 PM CDT WED MAY 14 2025
EARLY AFTERNOON WATER VAPOR IMAGERY SHOWS A WEAK UPPER LOW
ROTATING ACROSS EASTERN MN AND WESTERN WI WITH ANOTHER STRONGER
UPPER LOW UPSTREAM CENTERED OVER NORTHWEST WY. THUNDERSTORMS
HAVE DEVELOPED IN WESTERN SD IN THE DIFFLUENT FLOW ALOFT AND IN
WESTERN WI AND EASTERN MN. AT THE SURFACE, AN AREA OF LOW
PRESSURE WAS SEEN NEAR KLBF IN NE, WITH A WARM FRONT EXTENDING
EAST INTO NORTHERN MO. TEMPERATURES AT 2PM, WERE MAINLY IN THE
LOW 80S, WITH DEWPOINTS IN THE UPPER 50S.
LATE AFTERNOON/EVENING...BUILDING INSTABILITY AND STEEPENING LOW
LEVEL LAPSE RATES MAY ALLOW FOR A FEW ISOLATED SHOWERS AND
STORMS TO FORM IN NORTHERN IL. NO SEVERE WEATHER IS EXPECTED,
BUT ANY CELLS THAT FORM WILL BE SLOW MOVING BRINGING HEAVY RAIN.
ANY ACTIVITY WILL QUICKLY DISSIPATE AFTER SUNSET.
TONIGHT...THE AFOREMENTIONED WARM FRONT WILL LIFT NORTH ACROSS
EASTERN IA, NORTHEAST MO, AND NORTHWEST IL. SEVERAL CAMS,
INCLUDING THE 12Z HRRR, 12Z HREF, AND 00Z MPAS ENSEMBLE RUN
DEVELOP A WING OF ELEVATED SHOWERS AND ISOLATED STORMS
OVERNIGHT AND HAVE MAINTAINED SLIGHT CHANCE POPS FOR THIS. STEEP
MID-LEVEL LAPSE RATES OVER 8C/KM AND DEEP LAYER SHEAR JUST OVER
30KTS MAY SUPPORT SMALL HAIL IN THE STRONGEST CELLS.
TEMPERATURES OVERNIGHT WILL BE MILD, ONLY DROPPING INTO THE
UPPER 60S/LOW 70S WHICH IS WHAT OUR NORMAL HIGHS ARE FOR THE
MIDDLE OF MAY!
THURSDAY...A VERY WARM AND HUMID DAY IS EXPECTED AND OUR 1ST 90
DEGREE DAY OF THE YEAR FOR MOST LOCATIONS IS LIKELY. 850MB TEMPS
ARE PROGGED TO REACH 19-20C, WHICH IS CLOSE TO THE DAILY MAX PER
SPC CLIMATOLOGY AND IN THE TOP 30 SOUNDINGS FOR THE MONTH OF MAY
FOR THE ENTIRE DVN SOUNDING RECORDS DATING BACK TO FEB 1995.
OTHER THAN SOME CLOUD DEBRIS FROM EARLY MORNING ACTIVITY, DEEP
MIXING UP TO 850MB SHOULD ALLOW FOR DRIER DEWPOINT MIX DOWN
KEEPING HEAT INDICES BELOW ADVISORY LEVELS. HAVE RAISED HIGHS A
DEGREE OR TWO RESULTING IN NEAR RECORD TO RECORD HIGHS FOR SOME
IN THE LOW 90S. SEE CLIMATE SECTION BELOW. AN INTERESTING NOTE
IS THAT THE RAP/HRRR RUNS TODAY ARE EVEN WARMER THAN CURRENT
FORECAST. ALSO, I DISCOUNTED THE 12Z NAM/NAMNEST WITH ITS MOIST
BIAS SHOWING 71-74 DEGREE DEWPOINTS ADVECTING IN TOMORROW WHICH
THEN SHOWS THE MORE AGGRESSIVE SOLUTIONS FOR CONVECTION IN THE
AFTERNOON. A LESS HUMID AIRMASS WILL ADVECT INTO THE CWA LATE
THURSDAY, WITH DEWPOINTS CRASHING INTO THE UPPER 40S/LOW 50S.
SEVERE POTENTIAL
THERE REMAINS A CONDITIONAL RISK FOR SEVERE WEATHER DURING THE
LATE AFTERNOON AND EVENING. IF THE CAPPING INVERSION BREAKS
BETWEEN 850-700MB, THEN SEVERE STORMS WOULD BE POSSIBLE, WITH
ALL HAZARDS IN PLAY (MANY MODELS SHOW LOADED GUN SOUNDINGS
TOMORROW AFTERNOON ALONG THE HWY 20 CORRIDOR). THE AREA TO WATCH
IN OUR CWA FOR ANY CONVECTIVE INITIATION WOULD BE NORTH OF HWY
30 IN A NARROW WINDOW BETWEEN 3 AND 7 PM. FORCING INCREASES JUST
TO OUR NORTH AND EAST AHEAD OF THE DRYLINE EARLY EVENING, SO
THERE IS A POSSIBILITY WE MAY NOT SEE ANY ACTIVITY AT ALL (MOST
CAM SOLUTIONS SHOW THIS SCENARIO). WE WILL DEFINITELY NEED TO BE
WATCH OBSERVATIONAL AND SATELLITE TRENDS TOMORROW.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
ISSUED AT 220 PM CDT WED MAY 14 2025
FRIDAY...CLOSED UPPER LOW OVER MN WILL TRACK EAST TOWARDS LAKE
SUPERIOR, WHILE ANOTHER SHORTWAVE TROUGH MOVES EAST OVER THE CENTRAL
PLAINS. A WEAK SURFACE LOW WILL RIDE ALONG A COLD FRONT FROM
EASTERN KS INTO NORTHERN MO KEEPING THE 60+ DEGREE DEWPOINTS AND
ANY SUBSEQUENT SEVERE RISK TO OUR SOUTHEAST. BEHIND THE FRONT,
DEEP MIXING UP TO 800MB AND A STRONG PRESSURE GRADIENT WILL
BRING GUSTY WESTERLY WINDS OVER 30 MPH AT TIMES IN THE
AFTERNOON. SOME BUFR SOUNDINGS EVEN SHOW SOME NEAR ADVISORY
LEVEL WINDS COULD BE POSSIBLE WITH 45KT WINDS AT THE TOP OF THE
MIXED LAYER FOR LATER SHIFTS TO MONITOR. AFTERNOON HIGHS TO TOP
OUT IN THE LOW TO MID 80S.
THIS WEEKEND...BROAD UPPER LEVEL RIDGE ACROSS THE CENTRAL CONUS TO
BRING US DRY AND PLEASANT CONDITIONS WITH COMFORTABLE HUMIDITY.
FORECAST HIGHS ARE IN THE 70S AND LOWS IN THE UPPER 40S/LOW 50S.
EARLY NEXT WEEK...A DIGGING WESTERN CONUS LONGWAVE TROUGH TO TRACK
INTO THE CENTRAL PLAINS, SETTING THE STAGE FOR MORE ACTIVE WEATHER.
A FAVORABLE THERMODYNAMIC AND KINEMATIC SETUP FOR SEVERE WEATHER IS
EXPECTED MONDAY NIGHT THROUGH TUESDAY JUST TO OUR WEST WITH CSU ML
GUIDANCE HIGHLIGHTING WESTERN IA AND WESTERN MO UNDER A SLIGHT RISK.
FURTHER DETAILS ON THIS WILL BE MADE AVAILABLE IN LATER FORECASTS.
IN ADDITION, NBM/ECE/GEFS 24-HR RAINFALL PROBABILITIES GREATER
THAN 0.50" ARE IN THE 50-70% RANGE AT THIS TIME, WHICH WOULD BE
GREAT NEWS FOR SOME MUCH NEEDED RAIN FOR THE CWA.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1232 AM CDT THU MAY 15 2025
VFR TAFS ARE FORECAST THROUGH THE PERIOD. FEW TO SCATTERED
CLOUDS AROUND 9 KFT HAVE DEVELOPED ACROSS THE AREA AHEAD OF A
WARM FRONT THAT SITS TO OUR SOUTH. ISOLATED SHOWERS AND STORMS
ARE POSSIBLE TONIGHT BUT CONFIDENCE REMAINS LOW THAT THEY WILL
IMPACT ANY TAF SITES. SOUTHEAST WINDS AROUND 5 TO 10 KNOTS
OVERNIGHT WILL INCREASE TO 10 TO 15 KNOTS WITH GUTS UP TO 25
KNOTS AROUND 12 UTC. WINDS SHIFT TO THE SOUTH AROUND 15 UTC
WITH WINDS SUSTAINED AROUND 20 KNOTS AND GUSTS UP NEAR 30 KNOTS.
A FRONT IS FORECAST TO MOVE ACROSS THE AREA DURING THE
AFTERNOON AND SWITCH WINDS TO THE SOUTHWEST. WINDS WILL BEGIN TO
DIMINISH TO AROUND 10 KNOTS AFTER 00 UTC. CONFIDENCE REMAINS
LOW IN ANY STORM DEVELOPMENT IN THE 20 TO 00 UTC TIMEFRAME. IF
STORMS DID DEVELOP THAT WOULD BE IN THE VICINITY OF KDBQ AND
KMLI.
CLIMATE
ISSUED AT 220 PM CDT WED MAY 14 2025
RECORD HIGH TEMPERATURES:
MAY 15:
KBRL: 93 / 1944
KCID: 94 / 1941
KDBQ: 90 / 1944
KMLI: 91 / 1941
RECORD WARM LOW TEMPERATURES:
MAY 15:
KDBQ: 67 / 2001
KMLI: 69 / 2001
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...GROSS
LONG TERM...GROSS
AVIATION...COUSINS
CLIMATE...GROSS
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