862  
FXUS63 KDVN 252333  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
633 PM CDT WED MAY 25 2016  
   
..AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 340 PM CDT WED MAY 25 2016  
 
THE LATEST SFC ANALYSIS WAS INDICATING A LOW PRESSURE SYSTEM ACRS  
EXTREME SOUTHEASTERN SD...WITH MAIN ASSOCIATED WARM FRONT NOW  
ADJUSTED TO THE NORTH OF THE LOCAL AREA INTO SOUTHERN MN INTO WI.  
THE LATEST WATER VAPOR IMAGERY WAS INDICATING A VORT MAX ACRS  
NORTHEASTERN IA INTO MN, FLARING UP THE SHOWERS AND STORMS ACRS MN  
INTO WI ATTM. A TRAILING LOBE WAS SEEN JUTTING DOWN ACRS THE LOCAL  
AREA HELPING INDUCE THE SCTRD SHOWERS AND STORMS CURRENTLY IN NW  
IL. ANOTHER UPPER WAVE EMBEDDED IN BROAD SOUTHWESTERLIES WAS NOTED  
OUT ACRS NEB.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 340 PM CDT WED MAY 25 2016  
 
WILL KEEP ISOLATED TO LOW CHC POPS ACRS THE FAR NORTHEASTERN  
CWA/NW IL THROUGH 02Z OR SO FOR LINGERING ACTIVITY OR SOME SHORT  
LIVED NEW DEVELOPMENT OF SHOWERS AND STORMS IN THOSE AREAS, BUT  
GOOD CHANCE THAT MOST EVERYTHING WILL BE EAST OF THE CWA THIS  
EVENING AS THE MAIN UPPER WAVE PUSHES TOWARD NORTHERN WI/U.P. OF  
MI. THEN WE MAY HAVE A MID EVENING LULL OR JUST AN ISOLATED  
SHOWER/STORM WEST OF THE MS RIVER THRU MIDNIGHT. THEN AS THE  
ABOVE MENTIONED NEB WAVE ROLLS ACRS THE NORTHWEST HALF OF IA  
TOWARD MIDNIGHT, SEVERAL SOLUTIONS SUGGEST ENOUGH ELEVATED THTA-E  
FEED AND CONVERGENCE TO LEE OF THE VORT MAX TO SPARK AT LEAST SOME  
SCATTERED SHOWERS AND STORMS ACRS WESTERN INTO CENTRAL IA AS THE  
EVENING PROGRESSES...WITH SOME OF THIS MAKING IT ACRS THE LOCAL  
AREA FROM THE WEST ESPECIALLY AFTER MIDNIGHT.  
 
CURRENTLY THERE DOES NOT APPEAR TO BE ENOUGH SUPPORT FOR A FULL  
BLOWN MCS BARRELING IT'S WAY ACRS THE AREA, BUT WE MAY HAVE MORE  
IN THE WAY OF SOME STORM CLUSTERS TO GO ALONG WITH THE ISOLATED TO  
SCTRD SHOWERS/STORMS, ESPECIALLY SOUTH OF I80 LATE TONIGHT. WILL  
INCREASE CHANCE POPS AFTER MIDNIGHT, BUT WITH LACK OF CONFIDENCE  
IN COVERAGE AND THE WAY IT HAS BEEN GOING LATELY, DO NOT WANT TO  
TRY AND NAIL DOWN AREAS OF LIKELY POPS. SEE LITTLE IN THE WAY OF  
ANY SEVERE STORM THREAT ESPECIALLY AFTER MIDNIGHT, BUT THERE COULD  
BE LOCALLY HEAVY RAIN OF OVER A HALF INCH WHERE A MORE ENHANCED  
STORM CLUSTER MANAGES TO PROPAGATE OVER.  
 
THURSDAY...AFTER WHATEVER CONVECTIVE DEBRIS THERE IS CLEARS IN  
THE MORNING, A BOUT OF BOTH SFC AND UPPER RIDGING SHOULD MAKE THE  
DAY MAINLY DRY. WILL LEAN TOWARD WARM TEMPS OF MID TO UPPER 80S  
BANKING ON SOME INSOLATION EVEN IF FILTERED SOME BY CIRRUS. MORE  
SUN THAN CURRENTLY EXPECTED ALONG WITH MIXING POTENTIAL COULD MAKE  
FOR MORE WIDESPREAD UPPER 80S WITH EVEN A 90 DEGREE READING A GOOD  
BET. CONVECTIVE SPAWNING GROUNDS, WHICH COULD BE EXPLOSIVE, LOOKS  
TO TAKE PLACE LATE THU AFTERNOON AND EARLY EVENING TO THE WEST  
ACRS THE EAST CENTRAL PLAINS AND SOUTHERN MO RIVER VALLEY. ..12..  
   
LONG TERM
 
(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)  
ISSUED AT 340 PM CDT WED MAY 25 2016  
 
THURSDAY NIGHT...SOUTHWEST FLOW ALOFT WITH LITTLE IN THE WAY OF  
DIVERGENCE OVER E IOWA/W ILLINOIS. THE MAIN JET STREAK ASSOCIATED  
WITH THE SOUTHWEST LONGWAVE TROUGH WILL BE LOCATED OVER THE SOUTHERN  
PLAINS. LOWER IN THE ATMOSPHERE, CONVERGENCE ON THE NOSE OF THE 850  
MB LOW-LEVEL JET IS FOCUSED ACROSS E NEBRASKA AND SW IOWA.  
 
MCS INGREDIENTS ARE FAVORABLE OVER CENTRAL/EASTERN NEBRASKA AND SW  
IOWA WHERE SOUTHERLY 850MB FLOW CONVERGES BENEATH BROAD 300MB UPPER  
DIVERGENCE ZONE. FOR E IOWA/W ILLINOIS, WHERE CONDITIONS ARE LESS  
FAVORABLE, POPS ARE IN THE 50-60% RANGE. CURRENTLY, WIDESPREAD  
SHOWERS AND STORMS ARE NOT EXPECTED.  
 
FRIDAY...UPPER JET STREAK MOVES THROUGH THE CENTRAL PLAINS, WELL  
WEST OF E IOWA/W ILLINOIS. MODELS HAVE A SERIES OF EMBEDDED  
VORTICITY MAXIMA CROSSING THE UPPER MISSISSIPPI RIVER VALLEY THROUGH  
THE DAY; HOWEVER, CONFIDENCE IS LOW ON WHETHER THESE FORM AND WHERE  
THEY TRACK AS THEY ARE CONVECTIVELY INDUCED MESOSCALE FEATURES (PV  
ANOMALIES) IN THE MODELS. POPS ARE AROUND 60%...SO AT LEAST  
SCATTERED COVERAGE LOOKS LIKELY. HIGHS ARE FORECAST IN THE LOWER  
80S; DEWPOINTS IN THE MID 60S WILL MAKE IT FEEL MUGGY.  
 
THUNDERSTORM POTENTIAL: MODERATE INSTABILITY ON THE ORDER OF 1500-  
2500 J/KG MUCAPE BUT WEAK 0-6 KM BULK SHEAR IS AN ENVIRONMENT  
CONDUCIVE FOR AN ISOLATED STRONG STORM BUT AN OVERALL LOW SEVERE  
THREAT.  
 
SATURDAY...WEAK UPPER LEVEL DISTURBANCE INTERACTING WITH HUMID  
AIRMASS COULD RESULT IN ISOLATED TO SCT STORMS. AT THIS TIME,  
CHANCES FOR MEASURABLE RAIN FOR ANY ONE LOCATION REMAIN LOW AT 40-  
50%. FORECAST HIGHS ARE IN THE UPPER 70S TO LOWER 80S.  
 
SUNDAY...MODELS DIFFER ON TIMING AND STRENGTH OF SHORTWAVE CROSSING  
THE UPPER MIDWEST. LOW END 20-30% POPS FOR NOW UNTIL DETAILS BECOME  
MORE CLEAR. GENERAL SYNOPTIC SETUP DOES NOT LOOK FAVORABLE FOR  
WIDESPREAD CONVECTION. HIGHS ARE FORECAST IN THE LOWER 80S ON AVG  
WITH DEWPOINTS IN THE LOWER/MIDDLE 60S.  
 
MONDAY THROUGH WEDNESDAY...ABOVE AVERAGE TEMPS CONTINUE. WEAK  
PRESSURE FIELDS WOULD PREVENT SIGNIFICANT MOISTURE ADVECTION, EITHER  
POSITIVE OR NEGATIVE. THEREFORE, DEWPOINTS IN THE 60S ARE FORECAST  
ALONG WITH CHANCES FOR ISOLATED TO SCT STORMS. UTTECH  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 633 PM CDT WED MAY 25 2016  
 
WILL CONTINUE PREDOMINANTLY VFR CONDITIONS TONIGHT THROUGH  
THURSDAY. WHILE THERE WILL REMAIN THE POTENTIAL FOR AT LEAST  
SCATTERED THUNDERSTORMS LATER TONIGHT AND THROUGH THE DAY  
THURSDAY, THE PREDICTABILITY REMAINS TOO LOW TO PIN DOWN IN THE  
FORECASTS. THE EXCEPTION IS AT THE BRL TERMINAL, WHERE A PROB30  
GROUP WAS USED FOR POSSIBLE THUNDERSTORMS TOWARD SUNRISE. WINDS  
WILL REMAIN LIGHT SOUTHWEST TO SOUTH THROUGHOUT.  
 

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

 
 

 
 
SYNOPSIS...12  
SHORT TERM...12  
LONG TERM...UTTECH  
AVIATION...SHEETS  
 
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