Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 031136
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
636 AM CDT MON AUG 3 2015

.SYNOPSIS...
ISSUED AT 323 AM CDT MON AUG 3 2015

07Z SUBJECTIVE ANALYSIS PLACES COLD FRONT NEAR GALESBURG IL TO
KIRKSVILLE MO WITH THE FRONT EXTENDING BACK INTO SOUTHWEST NE
NEAR OGALLALA. NORTHERLY WINDS POST FRONTAL USHERING IN
COOLER AND DRIER AIRMASS... WITH TEMPS MAINLY IN THE 50S AND
DEWPTS IN THE 40S AND L50S ACROSS MUCH OF THE NORTHERN PLAINS AND
UPPER MIDWEST. DEEPENING NORTHERLY FLOW TO CONTINUE DRAWING DOWN
THIS COOLER AND DRIER AIRMASS OVER MUCH OF THE REGION NEXT 24 HRS
MAKING FOR SOME FANTASTIC WEATHER. ANOMALOUSLY DEEP MID TO UPPER
LEVEL LOW WAS LOCATED NEAR JAMES BAY RESULTING IN NORTHWEST FLOW
ALOFT ACROSS THE REGION. REGIONAL RADARS SHOW SQUALL LINE
ADVANCING SOUTHWARD ACROSS PORTIONS OF THE OHIO VALLEY... WHILE
ADDITIONAL CONVECTION WAS OCCURRING OVER PORTIONS OF NORTHWEST MO
AIDED BY AN UPPER LEVEL SHORTWAVE AND ISENTROPIC ASCENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CDT MON AUG 3 2015

FANTASTIC WEATHER IN STORE TODAY WITH DEEPENING NORTHERLY WINDS
TO DRAW DOWN DRIER AIR AND LOWERING DEWPTS WITH AMPLE SUNSHINE
WITH INCOMING SURFACE HIGH PRESSURE AND SUBSIDENCE MAKING FOR VERY
PLEASANT DAY. LIKELY TO DRAW DOWN DEWPTS INTO THE 50S MOST AREAS
BUT WITH DEEPER MIXING CANT RULE OUT A FEW 40S NORTH AND ALSO AT
VARIOUS AWOS SITES...WHILE SOME LOWER 60 DEWPTS COULD HANG ON
ACROSS THE FAR SOUTH IN CLOSER PROXIMITY TO FRONTAL ZONE AS IT
SLOWS AND EVENTUALLY STALLS OUT NEAR THE I-70 CORRIDOR ACROSS MO.
PRECIP CHANCES NOT ENTIRELY ZERO TODAY FAR SOUTH BEING IN CLOSE
PROXIMITY TO ELEVATED BAROCLINIC ZONE NEAR/NORTH OF COOL SIDE OF
FRONT... BUT MAIN CHANCES SHOULD RESIDE FROM PORTIONS OF NE INTO
MO. HIGHS TODAY PER PROGGED LOW LEVEL THICKNESS AND VERIFICATION
SUPPORTS UPPER 70S AND LOWER 80S... WHICH WOULD BE A FEW DEGS
BELOW NORMAL (81-86F).

TONIGHT... SURFACE RIDGE OF HIGH PRESSURE LARGELY IN CONTROL
PROVIDING TRANQUIL AND VERY PLEASANT CONDITIONS. LATE TONIGHT
THERE IS A SMALL CHANCE OF A SHOWER OR POSSIBLY WEAK STORM FAR
SOUTHERN CWA WITH ISENTROPIC LIFT ALONG ELEVATED NW TO SE BAROCLINIC
ZONE AHEAD OF UPPER LEVEL SHORTWAVE... BUT BETTER CHANCES WILL
REMAIN TO OUR WEST/SOUTHWEST FROM NE THROUGH MO. OTHERWISE...
CLEAR TO PARTLY CLOUDY SKIES GENERALLY WITH PLEASANT LOWS IN THE
50S...WITH LOWER 60S FAR SOUTH DUE TO MORE CLOUDS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 AM CDT MON AUG 3 2015

MAIN FORECAST CONCERN FOR THE LONG TERM IS THE ZONAL TO NW FLOW AND
RIPPLES THAT WILL MOVE THROUGH THE FLOW.  TOWARDS THE MIDWEEK AND
THEN THROUGH THE REST OF THE LONG TERM...THERE WILL BE CHANCES FOR
PRECIP AND THUNDER.  FOR THE MOST PART THE LARGE SCALE FLOW IS
SIMILAR IN THE MODELS.  SFC FEATURES ARE DIFFERENT AND THUS RESULT
IN DIFFERENT SOLUTIONS AT THE END OF THE PERIOD.

TUESDAY INTO THURSDAY...HIGH PRESSURE BUILDING SOUTH ACROSS THE
GREAT LAKES WILL HELP TO CREATE AN EASTERLY WIND INTO THE AREA.  AT
H85 AND H5 A RIDGE WILL BUILD INTO THE AREA.  THE EASTERLY WINDS
WILL HELP TO KEEP US DRY ACROSS THE AREA.  THE GFS ATTEMPTS TO BRING
IN A WARM ADVECTION WING INTO THE AREA OVERNIGHT TUESDAY INTO
WEDNESDAY.  THIS SEEMS UNREASONABLE GIVEN THE SFC FLOW AND
SUBSEQUENT UPPER LEVEL FEATURES THAT SHOULD HELP TO KEEP THE WARM
FRONT SOUTH.  THE MODELS ATTEMPT TO BRING A DECENT WAVE SOUTH OF THE
TROF INTO THE AREA.  THINK THAT CVA ASSOCIATED WITH THIS HELPS TO
BRING THE FRONT NORTH IN THE GFS.  THINK THIS IS OVERDONE.  BELIEVE
THAT THE BEST CHANCES WILL REMAIN SOUTH OF THE AREA OVERNIGHT
TUESDAY.  THE ECM SUPPORTS THIS THOUGHT.  WITH FLOW OFF THE
LAKE...THINK THE WARM ADVECTION WILL STRUGGLE TO MAKE IT NORTH
BEFORE THE LOW DEEPENS AND MOVES TO THE EAST.  THE 00Z ECM IS
BASICALLY DRY FOR US UNTIL THE END OF THE WEEK.  THINK THAT TRENDING
TOWARDS THIS SOLUTION IS REASONABLE.  WILL KEEP POPS AS AN NOD TO
THE GFS AND NAM...WILL LIKELY BE LOWERING THEM TONIGHT ON THE NEXT
MID SHIFT.

FRIDAY...THE NEXT WAVE IN THE FLOW ADVECTS INTO THE PLAINS.  THIS
WAVE WILL GO NEGATIVELY TILTED BEFORE IT GETS TO THE AREA AND THEN
TRIES TO CLOSE OFF AND SLOWLY MOVE TO THE EAST.  A FRONT ASSOCIATED
WITH THIS WAVE IS FORECAST TO ADVECT INTO THE AREA FRIDAY INTO
SATURDAY.  WITH LOWER DEWPOINTS AND THE BETTER FORCING NORTH...THINK
THAT ANY STORMS THAT DO FORM WILL STRUGGLE TO BECOME SEVERE. THE GFS
AND EURO DIFFER ON TIMING FOR THE SYSTEM.  THIS LEADS TO POPS BEING
IN FOR THE WEEKEND.  AS WE GET CLOSER THE ACTUAL DURATION OF PRECIP
AND POPS WILL LIKELY BE REDUCED AND SOME DRY SPELLS WILL EXIST THIS
WEEKEND.  THAT SAID....WITH THE FLOW BEING NW WE ARE AT THE WHIMS OF
RIPPLES THROUGH THE FLOW AND THEREFORE COULD SEE CONVECTION AND
POSSIBLE MCS THROUGH THE WEEKEND.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 629 AM CDT MON AUG 3 2015

VFR CONDITIONS WILL PERSIST NEXT 24+ HRS WITH SURFACE HIGH PRESSURE
BUILDING THROUGH THE REGION. AHEAD OF THE HIGH TODAY MIXING SHOULD
RESULT IN OCCASIONAL GUSTY NORTHWEST WINDS AROUND 10-15 KTS THAT
WILL BECOME LIGHT TONIGHT AS THE HIGH MOVES ACROSS. LATE TONIGHT
THERE IS A SMALL CHANCE OF A SHOWER MAINLY SOUTHWEST OF KBRL WITH
ISENTROPIC LIFT NORTH OF STALLED SURFACE FRONT ACROSS MO.

&&

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

$$

SYNOPSIS...05
SHORT TERM...05
LONG TERM...GIBBS
AVIATION...05



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