920
FXUS63 KDVN 082355
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
655 PM CDT WED JUL 8 2026
..00Z AVIATION UPDATE
KEY MESSAGES
- THERE IS A SLIGHT (LEVEL 2 OF 5) RISK FOR SEVERE STORMS LATE
THIS EVENING FOR AREAS NORTH OF A LINE FROM BELLE PLAINE IA TO
PLATTEVILLE WI. THE MAIN HAZARDS WILL BE DAMAGING WINDS AND
HEAVY RAIN.
- ADDITIONAL STORMS ARE LIKELY THURSDAY AND FRIDAY, WITH
HEAVY DOWNPOURS AND ISOLATED SEVERE POSSIBLE.
- ABOVE NORMAL TEMPERATURES NEXT WEEK, WITH A PROLONGED PERIOD
OF HEAT BECOMING MORE LIKELY.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 300 PM CDT WED JUL 8 2026
CURRENT RADAR AND SATELLITE OBSERVATIONS SHOW AREAS OF CONVECTION
ALONG A BROKEN LINE FROM NORTHEAST NE TO WEST-CENTRAL WI. THESE
STORMS WILL BE MUCH OF THE STORY FOR TONIGHT. AS THE SHORTWAVE MOVES
EAST, STORMS ARE EXPECTED TO GROW UPSCALE INTO A LINE AND MOVE
SOUTHEAST, REACHING THE HIGHWAY 20 AND I-380 CORRIDORS AROUND 9-10
PM. HOWEVER, THE QUESTION IS WHETHER THEY WILL DECAY OR CONTINUE.
WHILE CAPE WILL BE SUFFICIENT TO SUSTAIN ANY UPDRAFTS AT 1500-2000
J/KG, LOW LAPSE RATES AND LIMITED SHEAR WILL WILL BE LIMITING
FACTORS. GUIDANCE STILL REMAINS QUITE MIXED, WITH THE 12Z REFS
FAVORING STORMS CONTINUING WHILE THE 12Z HREF HAS THE STORMS DECAY
AS THEY REACH EASTERN IOWA. IF STORMS ARE ABLE TO MAINTAIN
THEMSELVES, THERE IS POTENTIAL FOR STRONG TO SEVERE STORMS. THIS
APPEARS MOST LIKELY FOR AREAS NORTH OF A LINE FROM BELLE PLAINE IA
TO PLATTEVILLE WI. DAMAGING WINDS WILL BE THE PRIMARY SEVERE THREAT
DUE TO DCAPE UP TO 1000 J/KG. HEAVY RAIN WILL ALSO BE POSSIBLE,
WHICH MAY POSE A FLASH FLOODING THREAT, ESPECIALLY IN AREAS THAT
RECEIVED HEAVY RAIN LAST WEEK. AS A RESULT, BOTH SPC AND WPC HAVE A
SLIGHT/LEVEL 2 RISK FOR SEVERE STORMS AND EXCESSIVE RAINFALL FOR
TONIGHT NORTH OF A LINE FROM BELLE PLAINE IA TO PLATTEVILLE WI.
ADDITIONAL STORM CHANCES ARE IN STORE FOR THURSDAY AS A BOUNDARY
MOVES SOUTHWARD ACROSS THE REGION. A SIMILAR ENVIRONMENT TO TODAY
WILL BE IN PLACE WITH MODERATE INSTABILITY, LOW LAPSE RATES, AND 15-
25 KTS OF SHEAR, AS WELL AS THE POTENTIAL FOR LINGERING SHOWERS AND
CLOUDS FROM OVERNIGHT. THUNDERSTORMS WILL BE POSSIBLE AS THE
BOUNDARY PASSES THROUGH, BUT THE THREAT OF STRONG TO SEVERE STORMS
WILL BE LOW.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 300 PM CDT WED JUL 8 2026
FRIDAY... A FINAL SHORTWAVE ON FRIDAY WILL BRING THE LAST NEAR-TERM
CHANCES FOR RAINFALL. ATMOSPHERIC MOISTURE WILL BE GREATEST ALONG
AND SOUTH OF INTERSTATE 80, WITH GUIDANCE SHOWING UP TO 1.5 INCH
PWATS AND DEWPOINTS IN THE LOW 70S. SHOWERS AND STORMS ARE LIKELY,
THOUGH SEVERE STORMS ARE NOT EXPECTED DUE TO MARGINAL DEEP LAYER
SHEAR. HOWEVER, IF A CONVECTIVELY AUGMENTED MCV WERE TO TAKE PLACE
UPSTREAM ENHANCING THE WIND FIELD, THEN SOME SEVERE STORMS WOULD BE
POSSIBLE.
SATURDAY AND BEYOND... MODEL GUIDANCE CONTINUES TO SHOW A LARGE
ANOMALOUS UPPER RIDGE (00Z NAEFS/ENS 2.0 TO 2.8 SIGMA FROM THEIR
ENSEMBLE MEAN) BUILDING INTO THE CENTRAL CONUS. IN FACT, THE 00Z
GEFS/ENS/GEPS HAS THIS RIDGE ENCOMPASSING MOST OF THE LOWER 48 BY
12Z TUESDAY WITH ITS CENTER NOT THAT FAR AWAY FROM THE LOCAL AREA.
AS A RESULT, A PROLONGED PERIOD OF DRY CONDITIONS, ABOVE NORMAL
TEMPS, AND BUILDING HEAT IS LIKELY. FACTORING IN EVAPOTRANSPIRATION
OF MATURING CROPS, MORE HEAT HEADLINES MAY BE NEEDED FOR AT LEAST A
PORTION OF THE AREA. APPARENT T PROBABILITIES OF 95 DEGREES OR
HIGHER OFF THE LREF (100 MEMBER ENSEMBLE OF THE GEFS/ENS/GEPS) ARE
IN THE 30-50% RANGE TUESDAY-THURSDAY. IF THAT WERE NOT ENOUGH, THE
LATEST CPC 8-14 DAY HAZARD OUTLOOK HAS A MODERATE (40-60%) RISK OF
EXTREME HEAT FOR MOST OF THE CWA JULY 16TH-18TH.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 650 PM CDT WED JUL 8 2026
MAIN TAF CONCERN AND CHALLENGE IS TRYING TO TIME A LINE OF
SCTRD THUNDERSTORMS DOWN OUT OF NORTHEAST IA AND HOW MUCH THEY
HOLD TOGETHER AND IMPACT THE SITES. TRIED TO TIME A 3-4 HOUR
WINDOW AT CID, DBQ, AND MLI USING THE LATEST CAMS AND
EXTRAPOLATING UPSTREAM RADAR MOVEMENT. MAY STILL BE A HOUR OR
TWO SLOW AS COMPARED TO REALITY IF THE STORMS SPEED UP SOME.
CHANCE OF THEM PRODUCE GUSTY OUTFLOW WINDS AHEAD OF THEM UP TO
AT LEAST 35 KTS AT CID AND DBQ, WEAKER BY THE TIME THE REMNANTS
OF THE CONVECTION GET TO MLI LATER ON. MOST MODELS REALLY DECAY
THE STORMS AS THEY MOVE SOUTHEASTWARD THROUGH THE AREA TONIGHT,
AND BRL MAY STAY DRY UNTIL THURSDAY MORNING. AWAY FROM THE
STORMS, MAINLY VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS.
WITH THE LIGHT WINDS, THERE MAY BE SOME MVFR FOG TOWARD DAWN AT
A FEW SITES. EXPECT A WIND SWITCH TO THE WEST-NORTHWEST BY LATE
THU MORNING. ISOLATED SHOWERS AND STORMS POSSIBLE THU AFTERNOON
BUT WILL LEAVE OUT TAF MENTION AT THIS TIME.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...ELLINGWORTH
LONG TERM...ELLINGWORTH/GROSS
AVIATION...12
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