Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 291202
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
702 AM CDT FRI AUG 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT FRI AUG 29 2014

TODAY...WILL WALK OUT ONGOING WARM AIR ADVECTION WING OF SHOWERS/
STORMS OUT OF THE NORTHWESTERN/NORTHERN THIRD OF THE DVN CWA BY
MID MORNING...WITH JUST A SLIGHT CHC OR ISOLATED COVERAGE OF OTHER
SHOWERS OR STORMS TO POP UP FURTHER TO THE SOUTH AS THE MORNING
PROGRESSES. MUCH OF THE CWA COULD BE DRY AFTER 12-14Z THIS MORNING
AS THE WING AND ASSOCIATED LEAD VORT LIFTS UP INTO MN AND WI.
THERE IS A SECONDARY LLVL CONVERGENT ZONE ACRS THE NORTHEASTERN
HALF OF IL THIS MORNING THAT COULD KEEP A FEW SHOWERS FESTERING IN
THE FAR EASTERN CWA THROUGH LATE MORNING. ISOLATED COVERAGE OR
MAINLY DRY CONDITIONS TO CONTINUE INTO EARLY TO MID AFTERNOON...
BEFORE MAIN UPPER WAVE/VORT COMPLEX SEEN NOW ON WATER VAPOR
IMAGERY ACRS KS INTO OK LOOKS TO LIFT UP ACRS THE MO RVR VALLEY
AND SOUTHWESTERN IA BY THIS EVENING. ALL SIGNS SUGGEST ANOTHER
ASSOCIATED LEAD WARM AIR ADVECTION WING AHEAD OF THIS FEATURE TO
POSSIBLY PRODUCE A BAND OF SHOWERS/STORMS THAT WILL GATHER
STRENGTH AND PUSH ACRS THE WESTERN HALF OF THE DVN CWA BY LATE
AFTERNOON AND INTO EARLY EVENING. DEPENDING ON EXTENT OF HEATING
AND INSTABILITY BUILD UP WHICH IS A BIG UNCERTAINTY...IF TEMPS
COULD AT LEAST REACH THE MID 80S WITH SFC DPTS IN THE UPPER 60S TO
LOWER 70S A FEW STRONG STORMS MAY OCCUR WITH WIND GUSTS OF 40 TO
50+ MPH AND HALF INCH HAIL. SFC WARM FRONT RETREAT SPEED AND
TIMING AND ADDITIONAL WAA TYPE CLOUDS TO BE BIG FACTORS...BUT WILL
BANK ON THE STRENGTH OF THE APPROACHING WAVE TO HELP LLVL WARM
PUSH UP THROUGH THE CWA AND LLVL SOUTHERLY FLOW. WITH EXTENT OF
MIXING...EVEN PARTLY SUNNY SKIES WILL ALLOW FOR WIDESPREAD LOW TO
MID 80S SOUTH OF THE WARM FRONT. MORE SUN AND DEEPER MIXING IN THE
THERMAL PROFILES ADVECTING UP ACRS THE AREA SUPPORT HIGHS IN THE
UPPER 80S TO AROUND 90. IF TEMPS COULD APPROACH THESE VALUES...A
BETTER CHC FOR ISOLATED SVR STORMS WITH DAMAGING WIND GUSTS THIS
AFTERNOON INTO EARLY EVENING. A STORM CLUSTER DEVELOPING A SFC
COLD POOL AND MIXING INTO A HIGHER CAPE FIELD. WILL PLAY HIGH
TEMPS IN THE MIDDLE OF THE ROAD OF THE POTENTIAL...AGAIN LEANING
TOWARD THE WARM FRONT MAKING HEADWAY THROUGH MUCH OF THE AREA BY
LATE AFTERNOON WITH SOUTH SFC WINDS LEADING TO MUCH OF THE FCST
AREA IN THE LOW TO MID 80S. OF COURSE ANOTHER DAY WITH BIG BUST
POTENTIAL...MORE CLOUDS AND FRONTAL HOLD UP WILL KEEP TEMPS IN THE
70S ALONG AND NORTH OF THE BOUNDARY...AND MORE SUN IN THE SOUTH
COULD MAKE FOR SOME UPPER 80S OR EVEN A 90.

TONIGHT...AS THE APPROACHING UPPER WAVE PROPAGATES ACRS CENTRAL IA
BY MIDNIGHT...MAIN LIFT WINDOW ACRS EASTERN IA INTO NORTHWESTERN IL
WILL OCCUR FROM 00Z-07Z OR SO AND EXPECT MOST COVERAGE OF A PRECIP
COMPLEX OF SHOWERS AND EMBEDDED THUNDERSTORMS ACRS THE CWA DURING
THAT TIME FRAME. HIGH POPS WARRANTED TONIGHT. SOME WINGS OF STRONGER
THUNDERSTORMS POSSIBLE ON SOUTHERN AND SOUTHEASTERN FLANK OF
CONVECTIVE SYSTEM. WITH PRECIPITAL WATER FEED OF 1.6 TO 1.8 INCHES
THIS EVENING AND DEEP LAYER SHEAR OF 30-35+ KTS...LOCALLY HEAVY
RAIN A GOOD BET WITH SOME LOCATIONS RECEIVING 1 TO 2 INCHES BY THE
TIME THE ACTIVITY STARTS TO MIGRATE EASTWARD OUT OF THE CWA AFTER
09Z SAT MORNING. MOST AREAS FROM 0.45 TO 1 INCH. IN AREAS THAT
GET HIT REPEATEDLY...URBAN AND SMALL STREAM FLOODING LIKELY WITH A
CHANCE AT EVEN LOCALIZED FLASH FLOODING. LOWS TONIGHT IN THE MID
60S IN THE NORTHWEST TO THE UPPER 60S TO AROUND 70 IN THE
SOUTHEAST.    ..12..


.LONG TERM...(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 348 AM CDT FRI AUG 29 2014

SHOWERS AND STORMS WILL MOVE THROUGH EARLY ON SATURDAY... BUT WILL
HAVE A CHANCE OF SOME REDEVELOPMENT SATURDAY AFTN WITH SECONDARY
VORT MAX ESPECIALLY NEAR AND EAST OF THE MISSISSIPPI RIVER.
OTHERWISE... HUMID WITH SKIES BECOMING PTSUNNY AND HIGHS GENERALLY
IN THE UPPER 70S AND LOWER 80S.

SAT NGT-SUN... MAINLY DRY PERIOD AS MID/UPPER LEVEL RIDGING BUILDS
IN OVER REGION IN WAKE OF DEPARTING TROUGH. SKIES SHOULD BE
CLEAR TO PTCLDY WITH LOWS SAT NGT IN THE 60S... AND WARMER HIGHS
ON SUNDAY MAINLY IN THE MID 80S WITH CONTINUATION OF HUMID
CONDITIONS.

SUN NGT-MON... THIS PERIOD LOOKS LIKE NEXT BEST CHANCE OF SHOWERS
AND STORMS WITH UPPER LEVEL SHORTWAVE MOVING FROM THE NORTHERN
PLAINS INTO THE UPPER MIDWEST...WITH ATTENDANT SURFACE LOW PASSING
TO OUR NORTH PULLING WARM FRONT NORTHWARD INTO THE REGION. THIS
SHORTWAVE AND WARM FRONT INTERACTION TO ALLOW FOR LIKELIHOOD OF
SHOWERS AND STORMS ACROSS THE AREA. TIMING OF MAINLY LATER SUNDAY
EVE AND OVERNIGHT WITH INITIAL WAVE OF PCPN LENDS A LIMITED SEVERE
POTENTIAL ALTHOUGH A FEW STRONG STORMS WITH GUSTY WINDS AND HAIL
MAY BE POSSIBLE MOSTLY WEST OF THE MISSISSIPPI RIVER. REDEVELOPMENT
OF SHOWERS AND STORMS ANTICIPATED MON AFTN AHEAD OF COLD FRONT
ATTENDANT TO PASSING UPPER MIDWEST SHORTWAVE. ANY SEVERE RISK WILL
BE DEPENDENT ON AMOUNT OF HEATING AND DESTABILIZATION... WHICH IS
A BIT UNCERTAIN THIS FAR OUT.

MON NGT-THU... LOWER CONFIDENCE EXISTS AS MODELS CONTINUE TO SHOW
SOME DISAGREEMENT ON PLACEMENT OF MAIN SYNOPTIC FRONT AND TIMING
OF SHORTWAVES IN ZONAL FLOW ALOFT. GENERAL SUGGESTION OF SUBTROPICAL
RIDGING FROM SOUTHERN PLAINS INTO THE SOUTHEAST WOULD LEND SUPPORT
TO FRONT STALLING OUT SOUTH OF THE CWA... BUT GIVEN POOR MODEL
CONSISTENCY HAVE TO UNFORTUNATELY MAINTAIN SLIGHT CHC POPS FOR MUCH
OF AREA FOR MUCH OF THIS PERIOD FOR NOW AND AWAIT BETTER CLARIFICATION
ON FRONTAL PLACEMENT AND TIMING OF DISTURBANCES. TEMPS OVERALL LOOK
TO BE NEAR SEASONAL NORMS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 645 AM CDT FRI AUG 29 2014

MAINLY VFR LEVEL CLOUDS THIS MORNING...WITH ISOLATED SHOWERS OR
THUNDERSTORMS POSSIBLE THROUGH MID MORNING MAINLY EAST OF THE MS
RVR. IFR FOG IN VCNTY OF DBQ TO LIFT BY 14Z. LINGERING OUTFLOW
BOUNDARIES TEMPORARILY SWITCHING WIND DIRECTION TO THE WEST OR
NORTHWEST THIS MORNING...BUT SOUTH WINDS TO TAKE OVER AGAIN AS
MORNING PROGRESSES. THEN MUCH OF THE DAY TO BE VFR WITH SOUTHERLY
SFC WINDS OF 8-15KTS. CONDITIONS TO THEN DETERIORATE FROM THE WEST
AND SOUTHWEST WITH EXPECTED SHOWERS/STORMS AS A WEATHER SYSTEM
MOVES ACROSS CENTRAL IA. CID TO POSSIBLY IMPACTED BY MVFR TO IFR
CONDITIONS WITH ROUNDS OF STORMS AFTER 22Z THIS AFTERNOON...THE
OTHER SITES 1 TO 3 HRS LATER. DID GENERAL LOWERING OF CONDITIONS IN
THE TAFS FOR NOW THIS EVENING...BUT HEAVY RAIN IN ROBUST SHOWERS/STORMS MAY
TEMPORARILY DROP VSBYS AND CIGS FURTHER DOWN THAN CURRENTLY FCST
AS THEY PASS BY. AFTER THE MAIN BAND OF PRECIP MOVES EAST OF THE
SITES LATE TONIGHT AFTER 07Z SAT AM...INCOMING CIGS TO BE MVFR WITH
SOME FOG OF 3-5SM INTO SAT MORNING.    ..12..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SHORT TERM...12
LONG TERM...05
AVIATION...12






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