Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KDVN 280845
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
345 AM CDT SAT MAR 28 2015

.SYNOPSIS...
ISSUED AT 317 AM CDT SAT MAR 28 2015

WATER VAPOR IMAGERY INDICATED A SHORTWAVE PASSING TO OUR SOUTHWEST
EARLY THIS MORNING. LIGHT SNOW WAS FALLING ACROSS CENTRAL IOWA INTO
MISSOURI. CIRRUS ASSOCIATED WITH THIS WAVE WAS SPREADING INTO
EASTERN IOWA...NORTHWEST ILLINOIS...AND FAR NORTHEAST MISSOURI.
CLOSER TO HOME...TEMPERATURES WERE MAINLY IN THE LOWER 20S ALONG AND
NORTH OF A LINE FROM FAIRFIELD TO GALESBURG WITH  MID 20S TO THE
SOUTH.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT SAT MAR 28 2015

THE MAIN FORECAST CONCERN WILL BE PRECIPITATION TYPE EARLY SUNDAY
MORNING. THE MODELS WERE IN GOOD OVERALL AGREEMENT WITH SOME MINOR
DIFFERENCES IN THE TIMING OF SUNDAYS AND THE STRENGTH OF THE WARM
ADVECTION.

THIS MORNINGS SHORTWAVE WILL PASS TO THE SOUTH UNDER STRONG NORTH TO
NORTHWEST FLOW ALOFT ACROSS THE CENTRAL US. AFTER THE PASSAGE OF
THIS SHORTWAVE...THE FLOW ALOFT WILL BECOME MORE ZONAL INTO SUNDAY
MORNING. HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION ON
SATURDAY BRINGING QUIET CONDITIONS AND TEMPERATURES 3 TO 5 DEGREES
WARMER THAN FRIDAY TO THE REGION.

AS HIGH PRESSURE DEPARTS TO THE EAST THE PRESSURE GRADIENT WILL
BEGIN TO TIGHTEN AS THE WINDS TURN TO THE SOUTH. THIS WILL HELP TO
DRAW WARMER INTO THE REGION AFTER 06 UTC ON SUNDAY. EXPECTING LOW
TEMPERATURES TO OCCUR PRIOR 06 UTC WITH A SLOW WARMING OVERNIGHT.
850 HPA LOW LEVEL JET AROUND 40 KNOTS` WILL HELP TO OVERSPREAD THE
REGION WITH MOISTURE. MODELS ARE IN GOOD OVERALL AGREEMENT OF
SATURATION OCCURRING AROUND 12 UTC ON SUNDAY WITH BULK OF THE
PRECIPITATION FALLING AFTER 12 UTC WITH THE ARRIVAL OF THE BEST
FORCING. SOME CONCERN THAT ANY LIGHT PRECIPITATION PRIOR TO 12Z
WOULD FALL AS FREEZING RAIN DEPENDING ON HOW QUICKLY TEMPERATURES
WARM. THE NAM WAS SLOWER SPREADING THE WARMER AIR EASTWARD OVERNIGHT
AND WOULD RESULT IN SOUNDINGS PREFERRING A LIGHT FREEZING RAIN WHILE
THE GFS WAS QUICKER WITH THE WARMER AIR AND A STRONG INVERSION IN
PLACE AND SURFACE TEMPERATURES ABOVE FREEZING LEADING TO
PRECIPITATION FALLING AS ALL LIQUID. WILL STAY WITH THE CURRENT
FORECAST TRENDS OF A WARMER SOLUTION AND KEEP PRECIPITATION AS ALL
RAIN.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 317 AM CDT SAT MAR 28 2015

MORE ACTIVE WEATHER DURING THE LONG TERM PERIOD IS COMPLICATED BY
CONTINUED MODEL INCONSISTENCY.

ON SUNDAY MORNING...BUFR SOUNDINGS ARE WARMER THAN RUNS LAST
NIGHT...NOW SUGGESTING A VERY LOW PROBABILITY OF A LIGHT MIX OF
PRECIP AT ONSET EARLY SUNDAY MORNING BEFORE A QUICK CHANGE OVER TO
RAIN. THUS...WILL MENTION ONLY RAIN IN FORECAST GRIDS...WITH QPF
EXPECTED TO BE GENERALLY UNDER 0.2 INCHES. HAVE CUT POPS BACK
DURING THE AFTERNOON HOURS AS THE 28/00Z ECMWF IS NOW ON BOARD
WITH FASTER TIMING. WESTERN PORTIONS OF THE FORECAST AREA ARE
FAVORED FOR A CLEARING WINDOW IN THE AFTERNOON AND SOUTHWEST FLOW
WITH A DECENT BUMP INTO THE 55 TO 60 DEGREE RANGE.

THE WARMING TREND WILL CONTINUE MONDAY THROUGH WEDNESDAY WITH MILD
ZONAL FLOW ALOFT. CONSENSUS BLEND TEMP GUIDANCE IS WARMER TODAY
AND NOW YIELDS HIGHS IN THE LOW 70S SOUTHWEST ON WEDNESDAY. OTHER
THAN A WEAK WAVE POSSIBLY CLIPPING THE FAR NORTHEAST MONDAY
NIGHT...EXPECT MAINLY DRY CONDITIONS THROUGH THE DAY ON WEDNESDAY.

A FRONT IS FORECAST TO MOVE THROUGH THE REGION WEDNESDAY NIGHT
INTO THURSDAY. CONFIDENCE IN THE TIMING IS A BIT HIGHER TODAY
BASED ON THE 28/00Z GFS/ECMWF/GEM. MODELS SUGGEST ENOUGH INSTABILITY
TO WARRANT AT LEAST A MENTION OF ISOLATED THUNDERSTORMS.

FOR THURSDAY AND FRIDAY...THE GFS/ECMWF DIVERGE WITH THE ECMWF
QUICKLY DEVELOPING ANOTHER...MORE POTENT SYSTEM WHILE THE GFS IS
VIRTUALLY DRY. NO REASON TO DIFFER FROM THE CONSENSUS LOW CHANGE
POPS AT THIS POINT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1149 PM CDT FRI MAR 27 2015

VFR CONDITIONS WILL PERSIST THROUGH SATURDAY EVENING WITH LIGHT WINDS
BECOMING S/SE AROUND 10 KTS ON SATURDAY AS HIGH PRESSURE MOVES INTO
THE OHIO VALLEY.

&&

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

$$

SYNOPSIS...COUSINS
SHORT TERM...COUSINS
LONG TERM...RP KINNEY
AVIATION...05





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.