087  
FXUS63 KDVN 170825  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
325 AM CDT TUE OCT 17 2017  
   
SYNOPSIS
 
 
ISSUED AT 324 AM CDT TUE OCT 17 2017  
 
AN AREA OF HIGH LEVEL CLOUDS OVERSPREAD EASTERN IOWA AND NORTHERN  
ILLINOIS DURING THE OVERNIGHT HOURS. A SOUTHERLY BREEZE AVERAGED 5  
TO 10 MPH. EARLY MORNING TEMPERATURES RANGED FROM THE UPPER 40S TO  
MID 50S.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 324 AM CDT TUE OCT 17 2017  
 
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS TEMPERATURES.  
WARM AIR ADVECTION WILL CONTINUE TO PICK UP TODAY WITH A SOUTHWEST  
BREEZE GUSTING AROUND 20 MPH AND PLENTY OF SUNSHINE. HAVE BUMPED  
AFTERNOON HIGHS UP SLIGHTLY, ESPECIALLY WEST WHERE THE WARMEST  
850MB TEMPS WILL RESIDE. AFTERNOON HIGHS SHOULD REACH THE UPPER  
60S TO LOW 70S, ABOUT 10 DEGREES ABOVE NORMAL FOR THE DATE.  
 
FOR TONIGHT, EXPECT A MOSTLY CLEAR SKY AND A SOUTH WIND STAYING UP  
AROUND 5 TO 8 MPH. LOWS WILL BE IN THE MID TO UPPER 40S.  
   
LONG TERM
 
(WEDNESDAY THROUGH MONDAY)  
ISSUED AT 324 AM CDT TUE OCT 17 2017  
 
WEDNESDAY THROUGH FRIDAY...RATHER BREEZY MILD DAY WED AHEAD OF  
INCOMING SFC FRONT SQUEEZED IN BETWEEN RIDGE CENTERS. MIXING UP TO  
BASE OF H8 MB INVERSION COMBINED WITH PLENTY OF INSOLATION MAKE FOR  
WIDESPREAD HIGHS WED IN THE LOW TO MID 70S. THEN A DRY FROPA LAYS  
THROUGH THE AREA WED NIGHT INTO THU MORNING, WITH WEAKER SFC WIND  
FLOW AND MIXING EXPECTED IN THE VICINITY OF THIS FEATURE FOR THU.  
WITH NOT MUCH IN THE WAY OF AIRMASS CHANGE, HIGHS ON THU MAY BE  
SIMILAR TO WED OR A DEGREE OR TWO COOLER DUE TO LESS MIXING DEPTH.  
PASSING SFC RIDGE AND UPSTREAM LLVL TROF/FRONT ORGANIZATION ACRS THE  
WESTERN PLAINS RE-INVIGORATES WARMING SOUTHERLY RETURN FLOW BY  
FRIDAY. CURRENTLY PROJECTED LLVL THERMAL PROFILES SUPPORTS  
UNSEASONABLY MILD HIGHS IN THE MID TO UPPER 70S FOR FRI, WITH AN  
OUTSIDE CHANCE AT AN 80 DEGREE READING SOMEWHERE AS LONG AS THE DAY  
REMAINS SUNNY.  
 
SATURDAY THROUGH MONDAY...LATEST SUITE OF MEDIUM RANGE MODEL RUNS  
STILL ADVERTISE INCREASING SOUTHERLY WARM MOIST CONVEYOR UP OFF THE  
WESTERN GULF AND TO THE LEESIDE OF AN APPROACHING L/W UPPER TROF  
WITH AN ASSOCIATED NORTH-TO-SOUTH ORIENTED SFC FRONT. THIS SHOULD  
BRING ABOUT THE NEXT PASSING PRECIP EVENT TO THE AREA SOMETIME THIS  
WEEKEND, BUT STILL WITHIN MODEL VARIANCES AT THIS POINT. THE GENERAL  
TREND WITH THE 00Z RUNS IS A BIT MORE PROGRESSION WITH THE SFC  
FRONT. BOTH THE 00Z GFS AND ECMWF NOW BREAK OUT WINGS OF WARM  
FRONTAL SHOWERS AND EVEN SOME THUNDER EARLIER IN THE DAY SAT ACRS  
THE CWA, BEFORE THE MAIN EVENT OF FRONTALLY SCOOPED UP LONG FETCH  
CONVEYOR OF SHOWERS AND EMBEDDED THUNDER SWEEP THROUGH LATER SAT  
NIGHT INTO SUNDAY MORNING. THE SLOWER ECMWF LINGERS RAINS WELL INTO  
SUNDAY AND IS LESS WET, WHILE THE MORE PROGRESSIVE GFS SWEEPS THE  
RAIN EAST BY MID SUNDAY MORNING. THE GFS IS ALSO MORE BULLISH WITH  
IT'S MOISTURE DRAW THIS FAR NORTH AND PRODUCES WELL OVER AN INCH OF  
RAIN IN THE SOUTH HALF OF THE CWA. THE ECMWF IS MORE IN THE WAY OF  
0.25 TO 0.75 OF AN INCH FOR THE LOCAL AREA WITH ITS HIGHER AMOUNTS  
ACRS THE WESTERN CWA. FOR NOW WILL STILL TARGET SAT NIGHT INTO EARLY  
SUNDAY AS THE MAIN PRECIP WINDOW WITH HIGH POPS, BUT WONDER WITH  
AMPLIFIED UPPER TROF AND FLANKING RIDGES, IF FURTHER MODEL RUNS WILL  
TREND SLOWER AGAIN.  
 
POST-SYSTEM COOL DOWN THEN LOOKS ON TAP FOR EARLY NEXT WEEK, WITH  
SOME CHANCE FOR SCTRD INSTABILITY SHOWERS LATER MONDAY AND IN/UNDER  
BASE OF DEEPENING COOL CORE UPPER TROF OVERHEAD. ..12..  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)  
ISSUED AT 1112 PM CDT MON OCT 16 2017  
 
THOUGH VFR / CLEAR WEATHER WILL LAST THROUGH THE NEXT 24 HOURS,  
THERE REMAINS LOW- LEVEL WIND SHEAR AT KCID, KDBQ, AND KMLI FOR  
LATE TONIGHT INTO EARLY MORNING AS WSW WINDS AROUND 2 KFT AGL  
INCREASE TO 30-40 KTS IS OCCURRING. THIS WILL DISSIPATE AROUND  
SUNRISE TUESDAY.  
 

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

 
 

 
 
SYNOPSIS...RP KINNEY  
SHORT TERM...RP KINNEY  
LONG TERM...12  
AVIATION...ERVIN  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IL Page
The Nexlab IA Page
The Nexlab MO Page Main Text Page