870
FXUS63 KDVN 120711
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
211 AM CDT TUE MAY 12 2026
KEY MESSAGES
- WINDY WEATHER TODAY WILL ACCOMPANY A LOW CHANCE (20-50%) FOR
GUSTY THUNDERSTORMS AS A COLD FRONT PASSES THROUGH THE AREA.
- A DEVELOPING LOW PRESSURE SYSTEM OVER SOUTH-CENTRAL CANADA
WILL KICK OFF A WARMING TREND STARTING ON THURSDAY AND BRING
THE CHANCE FOR NUMEROUS (60-80%) SHOWERS AND A FEW
THUNDERSTORMS TO THE AREA THURSDAY NIGHT.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 206 AM CDT TUE MAY 12 2026
A CLIPPER-TYPE SYSTEM IS MAKING ITS WAY SOUTHEAST THROUGH THE UPPER
GREAT LAKES REGION THIS MORNING, WITH THE COLD FRONT ALREADY
REACHING WESTERN MN BY 1 AM. THIS APPROACHING SYSTEM IS ALREADY
INCREASING THE SURFACE PRESSURE GRADIENT OVER OUR CWA, AND COMBINED
WITH A PUSH OF LAKE MICHIGAN LAKE BREEZE, WE'RE ALREADY SEEING
OCCASIONAL GUSTS FROM EAST TO AROUND 25 MPH AT TIMES.
THE FIRST HALF OF TODAY, STRONG WARM ADVECTION WILL TAKE PLACE AHEAD
OF THE COLD FRONT. THOUGH MOISTURE IS LIMITED WITH THIS ADVECTION,
CLOUDS AND SOME SCATTERED SHOWER / WEAK THUNDERSTORM ACTIVITY IS
EXPECTED TO APPROACH OUR NORTHERN COUNTIES THROUGH MID MORNING. MUCH
OF THIS MAY BE VIRGA, AND DESPITE DECENT DEPICTION ON RADAR, IT IS
QUESTIONABLE HOW MUCH OF THAT ACTIVITY WILL BE CAPABLE OF WETTING
SURFACES, AND EVENTUALLY MEASURING 0.01 OR MORE. FARTHER SOUTH, DRY
WEATHER AND PLENTY OF SUN WILL ALLOW FOR STRONG HEATING TODAY.
BY NOON AND THIS AFTERNOON, CLOUD COVER WILL BE MAINLY IN THE
CENTRAL AND SOUTHERN CWA AS THE FRONT MOVES THROUGH. THE NORTH
SHOULD BEGIN TO CLEAR OUT, AND WITH STRONG MIXING BEHIND THE FRONT,
AN AFTERNOON HIGH AROUND 80 REMAINS A SOLID FORECAST THERE, WHILE
THE CLOUDS MOVING IN DOWN SOUTH SHOULD HELP LIMIT THE HIGHS TO THE
LOWER 80S THERE. WINDS TODAY WILL BE STRONG AS TIMES, INITIALLY
FROM THE EAST/SOUTHEAST, THEN SOUTH, THEN BY AFTERNOON, SOUTHWEST
AND WEST. MODEL SOUNDINGS FROM BUFKIT SHOW MUCH OF THE WIND NEAR
THE TOP OF THE MIXED LAYER AROUND 35KTS, WHICH SHOULD RESULT IN
FREQUENT SURFACE GUSTS THIS AFTERNOON OF 30 TO 40 MPH. WHILE WE ARE
NO LONGER DEALING WITH DRY FUELS THIS LATE IN THE GREEN-UP SEASON,
ANY FIRE WOULD BEHAVE AGGRESSIVELY TODAY IN A RATHER LOW RH AND
GUSTY WIND ENVIRONMENT, SO AVOID BURNING ANYWAY.
SHOWER AND THUNDERSTORMS APPEAR RATHER SPOTTY TODAY, GIVEN THE
LIMITED MOISTURE ALONG THE FRONT. AS NOTED FROM SPC, IF DEWPOINT
VALUES COULD RISE THE MID 50S (CURRENTLY FORECAST TO REACH NEAR 50),
WE COULD SEE THUNDERSTORMS TAKE ADVANTAGE OF STEEP MID LEVEL LAPSE
RATES AND WINDS ALOFT TO BRING STRONG STORMS. THIS IS A LOW THREAT,
GENERALLY UNDER 20% OF HAPPENING, BUT IF IT DID, HAIL COULD APPROACH
1" AND GUSTS NEAR 60 ARE POSSIBLE. THIS THREAT, IS HIGHER THE
FARTHER EAST YOU GO, WHICH IS OUTLINED BY SPC TODAY.
THE FRONT WILL EXIT THE EAST/SOUTHEASTERN COUNTIES BY EARLY EVENING,
AND DRY WEATHER WILL CONFIDENTLY MOVE IN FOR THE OVERNIGHT. MODELS
HAVE BACKED OFF ON STRONG CAA WIND GUSTS OVERNIGHT, BUT NON THE
LESS, I STILL EXPECT A GUSTY NORTHWEST WIND INTO THE OVERNIGHT
HOURS, HITTING 20-30 MPH AT TIMES. LOWS TONIGHT IN THE UPPER 40S TO
LOWER 50S ARE NEAR THE MID RANGE OF NBM GUIDANCE.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 206 AM CDT TUE MAY 12 2026
WEDNESDAY... NORTHWEST FLOW ALOFT AND HIGH PRESSURE RETURN TO THE
REGION WEDNESDAY, ALLOWING FOR MOSTLY CLEAR SKIES AND SEASONABLE
HIGHS IN THE MID-60S TO MID-70S. A STRONG PRESSURE GRADIENT ON THE
BACKSIDE OF THE LOW PRESSURE OVER SOUTHEAST ONTARIO WILL SUPPORT
GUSTY NORTHWEST WINDS UP TO 30 MPH, BUT THE WINDS ARE FORECASTED TO
SUBSIDE GOING INTO WEDNESDAY NIGHT AS LOWS DROP INTO THE 40S AREA-
WIDE.
THURSDAY-FRIDAY... THE NEXT TROUGH MOVES ACROSS THE NORTHERN ROCKIES
ON THURSDAY, STRENGTHENING A MID-LATITUDE CYCLONE OVER SASKATCHEWAN.
THIS SHOVES A LONGWAVE RIDGE OVER THE MIDWEST AS SURFACE FLOW TURNS
TO SOUTHEASTERLY AHEAD OF THE APPROACHING COLD FRONT. A WARMING AND
MOISTENING TREND KICKS OFF AS HIGHS CLIMB BY 3-5 DEGREES AND PWATS
INCREASE OVER 0.5 INCH. BY THURSDAY NIGHT, A PRE-FRONTAL TROUGH AND
LOW-TO-MID-LEVEL ISENTROPIC UPGLIDE COULD PRODUCE SOME SCATTERED
SHOWERS AND THUNDERSTORMS, BUT THE MAIN SURFACE FRONT STALLS OUT
OVER THE UPPER MISSISSIPPI RIVER VALLEY AS THE 500 MB TROUGH
NEGATIVELY TILTS OVER SOUTH-CENTRAL CANADA, OCCLUDING THE MID-
LATITUDE CYCLONE. DUE TO LIMITED INSTABILITY AND LACK OF LOW-
LEVEL SUPPORT, THE SEVERE THREAT FOR THESE STORMS IS CURRENTLY
LOW.
ON FRIDAY, CONVERGENCE ALOFT AND DRY AIR ADVECTION IN THE MID-LEVELS
WILL LIMIT POPS. THERE IS MODEL UNCERTAINTY ON IF THE COLD FRONT
CLEARS THE CWA OR NOT WHICH WILL HAVE AN INFLUENCE ON THE HIGHS AS
SEEN IN THE LREF PROBABILITIES OF HIGHS EXCEEDING 80 DEGREES ONLY
BEING 30-60%. REGARDLESS, THIS BOUNDARY WILL PROVIDE A SOURCE OF
LIFT HEADING INTO THE WEEKEND AS THE NEXT SYSTEM APPROACHES.
SATURDAY-MONDAY... A SHORTWAVE IN THE SUBTROPICAL JET STREAM OVER
THE DESERT SOUTHWEST IS PULLED TO THE NORTHEAST INTO THE CENTRAL
PLAINS BY A LONGWAVE TROUGH OVER THE PACIFIC NORTHWEST. AS A LOW
PRESSURE DEEPENS OVER WESTERN KANSAS AND NEBRASKA, THE STALLED
BOUNDARY FROM FRIDAY IS EXPECTED TO BE PULLED NORTHWARD AS THE
SUBTROPICAL TROUGH PASSES OVER THE REGION, BRINGING POPS BACK UP
OVERNIGHT SATURDAY. AS THE TROUGH FROM THE PACIFIC NORTHWEST ENTERS
THE NORTHERN PLAINS ON SUNDAY, A COLD FRONT IS EXPECTED TO MOVE INTO
IOWA. STEEPER LAPSE RATES SHOULD PROVIDE ENOUGH INSTABILITY FOR
THUNDERSTORMS DEVELOPMENT WITH THE GFS ENSEMBLES SHOWING A 40-70%
CHANCE OF SBCAPE EXCEEDING 1000 J/KG. MODEL UNCERTAINTY ARISES AGAIN
SUNDAY NIGHT INTO MONDAY AS THE ECMWF ENSEMBLES HAVE A FASTER,
NORTHELY STORM SYSTEM WHICH HAS THE COLD FRONT CLEARING THE REGION
WHILE THE GFS ENSEMBLES HAVE A SLOWER, SOUTHERLY TRACK THAT KEEPS
POPS AND THUNDERSTORMS CHANCES HIGH INTO MONDAY.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1256 AM CDT TUE MAY 12 2026
DESPITE THE PASSING COLD FRONT AND CLOUDS, VFR CONDITIONS ARE
EXPECTED THROUGH THE NEXT 24 HOURS WITH THE MAIN FOCUS ON GUSTY
CONDITIONS AS THE WIND SHIFTS FROM SOUTHEAST TO NORTHWEST. WIND
GUSTS ABOVE 30 KNOTS ARE POSSIBLE AHEAD OF THE FRONT DURING THE
AFTERNOON. PREVIOUS TAFS HAD LLWS FOR KCID, KDBQ, AND KMLI, BUT
IT WAS REMOVED FROM THIS ISSUANCE DUE TO A LAKE BREEZE
ENHANCEMENT OF SURFACE WINDS AND GUSTS, PRIMARILY NORTH OF I-80.
KBRL RETAINS LLWS AS A 35-45 KNOT LOW-LEVEL JET DEVELOPS PRIOR
TO SUNRISE ABOVE WEAKER SURFACE WINDS. THE FRONT WILL ALSO BRING
A CHANCE (20-40%) FOR SHRA ACROSS THE AREA, BUT ONLY PROB30S
FOR -SHRA WERE GIVEN TO KDBQ AND KMLI DUE TO GREATER LOW-LEVEL
SATURATION. REGARDLESS, CEILINGS WILL REMAIN ABOVE 8 KFT IN THE
VFR CATEGORY. SKIES ARE FORECASTED TO CLEAR OUT DURING THE
EVENING FROM NORTH TO SOUTH AS WINDS SHIFT TO THE NORTHWEST.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...ERVIN
LONG TERM...DELAUNE
AVIATION...DELAUNE
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