033  
FXUS63 KDVN 231128 AAA  
AFDDVN  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
628 AM CDT SUN APR 23 2017  
   
..AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 317 AM CDT SUN APR 23 2017  
 
HIGH PRESSURE WAS CENTERED OVER THE GREAT PLAINS THIS MORNING.  
THIS LED TO CLEAR SKIES AND NEAR CALM WINDS TONIGHT. TEMPERATURES  
RANGED FROM THE UPPER 30S TO THE MID 40S EARLY THIS MORNING. THIS  
HIGH PRESSURE ISN'T FORECAST TO MOVE MUCH THROUGH THE SHORT TERM  
AND IS THE PRIMARY WEATHER PRODUCER DURING THIS PERIOD.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 317 AM CDT SUN APR 23 2017  
 
THE BEAUTIFUL SUNDAY THAT HAS BEEN FORECAST FOR THE PAST FEW DAYS  
IS NOW HERE. MAIN FORECAST CONCERN IN THE SHORT TERM PERIOD ARE  
THE HIGH AND LOW TEMPERATURES. H5 RIDGING AND CONVERGENCE WILL  
LEAD TO SUBSIDENCE ACROSS THE AREA. THE FLOW IS FORECAST TO TURN  
ZONAL LATER DURING THE DAY AND MAY ADVECT IN SOME VERY HIGH  
CIRRUS. OTHERWISE, LIGHT WINDS WITH HIGHS IN THE UPPER 60S TO LOWS  
70S ARE STILL EXPECTED. MOST OF THE DETERMINISTIC MODELS SEEM TO  
BE TOO LOW WITH THEIR HIGHS TODAY SO TRENDED TOWARDS MOS AND RAP  
MODEL GUIDANCE.  
   
LONG TERM
 
(MONDAY THROUGH SATURDAY)  
ISSUED AT 317 AM CDT SUN APR 23 2017  
 
A UNSETTLED PERIOD OF SHOWERS AND EMBEDDED STORMS BECOMING MORE  
LIKELY MID TO LATE THIS WEEK WITH SIGNIFICANT RAINFALL AMOUNTS.  
 
LONG TERM FORECAST CONFIDENCE ASSESSMENT...FAIR TO POOR OR AVERAGE  
TO BELOW AVERAGE. REASON IS TRENDS ARE NOW SHOWING A COMMON SPRING  
PHENOMENA OF SYSTEM SLOWING DOWN AS JET STARTS TO DECELERATE. THIS  
RESULTS IN SLOWER AND LARGER STORMS SYSTEMS ALONG FRONT. RUN TO RUN  
OF ALL SOLUTIONS SUGGEST THIS ISN'T DONE SO TIMING, COVERAGE AND  
AMOUNTS OF PRECIPITATION WITH EACH DAY ARE STILL POOR WHERE  
BOUNDARIES AND LOWS TRACK STILL UNCERTAIN. WHAT IS APPARENT IS  
MARGINAL OR NO SEVERE WEATHER RISK REMAINS THE CASE WITH MOST  
LOCATIONS PICKING UP RAIN AMOUNTS OF .5 TO 1.5+ INCHES BY NEXT  
SUNDAY. AREA HIGHS AND LOWS DAYS 3-7 DUE TO CLOUD COVERAGE AND  
PRECIPITATION MAY EASILY BE OFF BY 5+ DEGREES WITH TIMING, COVERAGE  
AND UNCERTAINTY OF ABOVE ISSUES.  
 
MONDAY...ONCE AGAIN ONLY MINOR CHANGES. LAST FAIR AND MILD DAY WITH  
SLIGHTLY ABOVE NORMAL TEMPERATURES OF 70 TO 75 DEGREES. SOUTHERLY  
OF 10 TO 20+ MPH. LOWS MOSTLY LOWER 50S FOR TUESDAY AM.  
 
TUESDAY & TUESDAY NIGHT...A SLOWER FRONTAL SYSTEM TO APPROACH LATE  
WITH BEST FORCING BEHIND BOUNDARY FOR DRY OR MOSTLY DRY DAY. DELAYED  
PASSAGE OF FRONT AND SUNSHINE SHOULD SUPPORT HIGHS LOWER TO MIDDLE  
70S AND POSSIBLY SOME UPPER 70S SE SECTIONS. HAVE 20 TO 30 POPS OF  
SHOWERS WITH ISOLATED STORMS NORTHWEST WITH LIMITED INSTABILITY AND  
MOISTURE RESULTING IN CAPE VALUES AOB 500 J/KG OR JUST A FEW BRIEF  
NON-SEVERE STORMS. TUESDAY NIGHT...INCREASED POPS AS FRONT NEARLY  
STALLS AND LOW APPEARS LIKELY TO DEVELOP IN MISSOURI FOR ENHANCED  
FORCING. TRENDS SUGGEST HIGHER POPS WITH MODERATE RAIN AMOUNTS WITH  
ONLY EMBEDDED STORMS OF NON-SEVERE NATURE ATTM. MINS MOSTLY  
LOWER/MID 50S WITH UPPER 40S FAR NW SECTIONS.  
 
WEDNESDAY & WEDNESDAY NIGHT...LOTS OF CLOUDS AND RAIN SUGGESTED AS  
SURFACE LOW TRACKS ACROSS THE REGION WITH JUST EMBEDDED STORMS WITH  
LIMITED INSTABILITY OF CAPE AOB 750 J/KG. MODERATE RAIN TOTALS  
MOSTLY SUGGESTED ATTM. HIGHS MID 50S NORTHWEST TO MID 60S SE  
SECTIONS. WEDNESDAY NIGHT...BLUSTERY NORTHWEST WINDS TO BRING IN  
COLDER AIR WITH CONCERN CLOUDS/MIXING SUPPORTS LOWS ABOUT 3 DEGREES  
HIGHER OF CURRENT MOSTLY UPPER 30S TO LOWER 40S FOR LATER SHIFTS TO  
REASSESS. STRENGTH AND TRACK OF LOW MAY CHANGE AS WELL AS IMPACTING  
AREA LOWS AND WHEN RAINS END.  
 
THURSDAY AND THURSDAY NIGHT...MOSTLY FAIR TO PARTLY CLOUDY WITH  
COLDER AIR AND HAVE LOWERED HIGHS INTO THE MID TO UPPER 50S AND DRY  
WITH LIGHT TO MODERATE NORTHWEST WIND. THURSDAY NIGHT...CLOUDS TO  
INCREASE LATE AHEAD OF NEXT SYSTEM WHICH MAY IMPACT LOWS WITH  
CURRENT FORECAST OF UPPER 30S NORTH TO MID 40S SOUTH. IF TREND FOR  
NEXT SYSTEM TO BE SLOWER, THEN CLOUDS WILL BE DELAYED AND LOWS COULD  
BE EASILY 3 TO 5 DEGREES TOO HIGH FOR LATER SHIFTS TO REVIEW.  
 
FRIDAY AND SATURDAY...LOW CONFIDENCE FORECAST. REASON IS TRACK AND  
TIMING ON NEXT DECENT STORM SYSTEM. BEST ESTIMATES ARE DECENT RAINS  
EXPECTED WITH LOCALLY 1+ INCH AMOUNTS POSSIBLE OF RAIN SHOWERS AND  
SOME EMBEDDED THUNDER AND BRISK EASTERLY WINDS OVER AT LEAST NORTH  
1/2 OF THE REGION. HIGHS IN THE 50S AND 60S WITH LOW TRACK KEY TO  
HOW MUCH OF THE AREA IS IN THE 50S OR 60S. FRIDAY NIGHT...LOWS IN  
THE 40S TO NEAR 50F SOUTH. SATURDAY NIGHT LOWS IS BASED ON CLEARING  
AS STORM SYSTEM MOVES NE WITH MOSTLY LOWER TO MIDDLE 40S WHICH IF  
LOW IS STRONGER AND CLEARING OCCURS ARE 3 TO 5 DEGREES TOO HIGH.  
 
SUNDAY...HIGHS PRESSURE TO MOVE IN WITH COOL BELOW NORMAL TEMPS WITH  
HIGHS IN THE 50S AND LOWS SUNDAY NIGHT IN THE 40S WITH SOME 30S  
POSSIBLE.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)  
ISSUED AT 627 AM CDT SUN APR 23 2017  
 
VFR CONDITIONS WITH LIGHT WINDS AND CLEAR SKIES TODAY. NO MAJOR  
WEATHER IMPACTS TO AVIATION EXPECTED.  
 

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

 
 

 
 
SYNOPSIS...GIBBS  
SHORT TERM...GIBBS  
LONG TERM...NICHOLS  
AVIATION...GIBBS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

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