Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 312313
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
613 PM CDT MON AUG 31 2015

.SYNOPSIS...
ISSUED AT 343 PM CDT MON AUG 31 2015

12Z UPPER AIR  ANALYSIS HAS AN UPPER LEVEL HIGH FROM THE SOUTHERN
ROCKIES INTO THE GREAT LAKES. A WEAK UPPER LOW WAS OVER INDIANA
THAT GENERATED SOME EARLY MORNING CONVECTION IN EASTERN ILLINOIS.
SATELLITE TRENDS THROUGH MID AFTERNOON SOME DIURNAL CLOUDS ACROSS
THE AREA WITH A HIGH LEVEL SMOKE LAYER OVER THE MIDWEST.

18Z SFC DATA HAS HIGH PRESSURE OVER THE APPALACHIAN MOUNTAINS WITH A
WEAK LOW IN SOUTHEAST COLORADO. A SEASONABLY STRONG COLD FRONT RAN
FROM THE COLORADO LOW INTO NORTHWEST MINNESOTA. DEW POINTS WERE IN
THE 60S AND 70S FROM THE OHIO VALLEY AND GREAT LAKES WEST INTO THE
PLAINS. DEW POINTS WERE IN THE 40S AND 50S BEHIND THE COLD FRONT.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 343 PM CDT MON AUG 31 2015

SATELLITE THROUGH MID AFTERNOON HAS DIURNAL CLOUDS THAT HAVE NOT
SHOWN ANY ADDITIONAL VERTICAL DEVELOPMENT. BASED ON THESE
TRENDS...DRY BUT VERY WARM AND HUMID CONDITIONS SHOULD BE SEEN
THROUGH SUNSET.

AFTER SUNSET...DRY BUT MUGGY CONDITIONS ARE EXPECTED THROUGH SUNRISE
TUESDAY. GIVEN THE LIGHT WINDS AND HIGH MOISTURE LEVELS IN THE LOWER
ATMOSPHERE...SOME PATCHY FOG SHOULD DEVELOP AFTER MIDNIGHT.

ON TUESDAY...ANY PATCHY FOG THAT DEVELOPS WILL DISSIPATE DURING THE
MORNING COMMUTE. AFTERWARDS...VERY WARM AND HUMID CONDITIONS ARE
THEN EXPECTED. TEMPERATURES ON TUESDAY SHOULD BE A LITTLE WARMER
THAN MONDAY. HEAT INDEX READINGS SHOULD BE 90 TO 95 ACROSS THE AREA.

DRY CONDITIONS ARE CURRENTLY EXPECTED ON TUESDAY GIVEN THE UPPER
LEVEL HIGH ACROSS THE AREA. HOWEVER...ONE CANNOT ENTIRELY RULE OUT
SOME EXTREMELY ISOLATED AFTERNOON CONVECTION GIVEN THE WARMER
TEMPERATURES. IF SAID CONVECTION DOES OCCUR...THE AREAL COVERAGE
WOULD BE 1 OR 2 PERCENT AT BEST.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 343 PM CDT MON AUG 31 2015

UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT WEATHER FEATURE INTO
NEXT WEEKEND AS PATTERN IS STAGNANT WITH JET STREAM DIPPING
INTO THE WEST AND THEN ARCING NORTHWARD WELL INTO CANADA. THE
RESULT WILL BE GOOD OLD FASHIONED SUMMER WX WITH LITTLE DAY TO
DAY CHANGE FOR MUCH OF THE EXTENDED WITH ABOVE NORMAL TEMPS
(HIGHS MID 80S TO LOWER 90S... AND LOWS MID 60S TO LOWER 70S)...
HUMID CONDITIONS AND POTENTIAL FOR ISOLD PM AIRMASS SHOWERS AND
STORMS.

LATE IN THE WEEKEND THROUGH EARLY NEXT WEEK CONTINUED SIGNS OF
A BREAK DOWN IN THE PATTERN... AS UPPER LEVEL TROUGH OVER THE WEST
IS SHOWN TO EJECT ACROSS THE NORTHERN CONUS SUPPRESSING THE
RIDGE FURTHER SOUTH AND EVENTUALLY LEADING TO COOLER TEMPS AND
INCREASING CHANCES FOR WETTING RAINS AS SYSTEM INTERACTS WITH
MONSOONAL MOISTURE. THERE HOWEVER REMAINS TYPICAL TIMING CHALLENGES
WITH THE ECMWF SLOWER WITH EJECTING TROUGH AND ATTENDANT COLD
FRONT... WHILE THE GFS IS MORE PROGRESSIVE ALTHOUGH DPROG/DT OF
PREVIOUS GFS MODEL RUNS SHOW SOME SLOWING. IF SLOWING TREND
CONTINUES THEN WILL NEED TO POSSIBLY LOOK AT NUDGING UP HIGHS A BIT
MORE FOR SAT/SUN WITH MANY AREAS AROUND 90 OR LOWER 90S GIVEN
H85 TEMPS OF 20-21C SHOWN BY GFS AND ECMWF. POPS REMAIN A BLENDED
APPROACH... BUT IF SLOWING TREND PERSISTS THEN WOULD NEED TO BE
LOWERED ESPECIALLY SUNDAY/SUNDAY NIGHT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 612 PM CDT MON AUG 31 2015

A WEAK FLOW UNDER AN UPPER LEVEL RIDGE WILL KEEP LIGHT WINDS AND
STABLE CONDITIONS OVER THE AREA THROUGHOUT. HIGH ALTITUDE SMOKE
FROM WESTERN U.S. WILDFIRES WILL RESULT IN HAZE ALOFT...WHICH IS
EXPECTED TO THIN OUT OVERNIGHT INTO TUESDAY. AT THE SURFACE...
LINGERING MOISTURE WILL AGAIN LEAD TO FOG...WHICH IS ONLY EXPECTED
TO RESULT IN MVFR CONDITIONS FROM AROUND MIDNIGHT THROUGH A
COUPLE HOURS AFTER SUNRISE. THERE IS A POTENTIAL FOR LOWER
CONDITIONS AT MAINLY CID AND DBQ...WHERE EARLY MORNING TEMPO
GROUPS FOR VISIBILITIES IN IFR RANGE ARE INCLUDED.

&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...05
AVIATION...SHEETS


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