118  
FXUS63 KDVN 191049  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
549 AM CDT SUN MAY 19 2019  
   
..AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 325 AM CDT SUN MAY 19 2019  
 
THE BETTER FORCING ON THE NOSE OF THE LLJ HAS SHIFTED NORTHWARD  
AND MUCH OF THE SHOWERS AND STORMS WERE NORTH AND EAST OF THE DVN  
CWA. A FEW SHOWERS AND STORMS WERE NOTED IN NORTHERN/CENTRAL MO.  
TEMPERATURES ACROSS THE DVN CWA EARLY THIS MORNING WERE IN THE MID  
60S AT MOST LOCATIONS.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 325 AM CDT SUN MAY 19 2019  
 
HEADLINES: THE FLASH FLOOD WATCH HAS BEEN CANCELLED AS THE THREAT  
OF WIDESPREAD HEAVY RAINFALL HAS ENDED. THE AIRMASS WAS BECOMING  
DRIER AND SHEAR/INSTABILITY WAS MINIMAL.  
 
TODAY: A FEW SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED  
MAINLY THIS MORNING AS LOW PRESSURE TRACKS FROM EASTERN IA INTO  
NORTHERN LOWER MI LATER TODAY. THE AIRMASS WILL CONTINUE TO DRY  
OUT AS WINDS TURN SOUTHWEST WITH DECREASING COVERAGE OF SHOWERS.  
THE MAIN AREA OF STRONGER STORMS LATER TODAY LOOKS TO BE WELL  
EAST OF THE DVN CWA ALONG THE COLD FRONT.  
 
FORECAST SOUNDINGS INDICATE A DEEP SW TO W FLOW IN THE COLUMN  
WITH 35-40 KTS WINDS AT THE MIXED LAYER. THIS WILL BE A WINDY DAY  
ESPECIALLY FROM LATE THIS MORNING THROUGH THE AFTERNOON.  
CONSIDERED A WIND ADVISORY BUT FOR NOW THE SITUATION LOOKS  
MARGINAL FOR HEADLINES, BUT THE DAY SHIFT CAN MONITOR TRENDS. AS  
OF NOW, WIND GUSTS OF AROUND 40 MPH SEEM LIKELY. HIGHS WILL RANGE  
FROM THE LOWER 60S NW TO THE LOWER 70S SE.  
 
TONIGHT: A QUIET AND BELIEVE IT OR NOT A DRY NIGHT EXPECTED AS  
LOW PRESSURE PUSHES INTO THE NORTHERN GREAT LAKES REGION, AND HIGH  
PRESSURE RIDGE BUILDS INTO WESTERN IA FROM THE NORTHERN PLAINS.  
SKIES SHOULD CLEAR AFTER MIDNIGHT AND W TO NW WINDS WILL GRADUALLY  
DIMINISH. TEMPERATURES WILL BE COLDER WITH LOWS IN THE UPPER 30S  
TO LOWER 40S.  
   
LONG TERM
 
(MONDAY THROUGH SATURDAY)  
ISSUED AT 325 AM CDT SUN MAY 19 2019  
 
COOL TEMPERATURES TO START THE WEEK FOLLOWED BY A WARM UP AND THEN  
ANOTHER COOL DOWN FOR NEXT WEEKEND. OVERALL WEATHER PATTERN TO  
REMAIN VERY ACTIVE WITH SEVERAL ROUNDS OF RAIN.  
 
MONDAY  
ASSESSMENT...HIGH CONFIDENCE  
 
DRY AND VERY COOL CONDITIONS WILL BE SEEN MONDAY AS HIGH PRESSURE  
QUICKLY MOVES THROUGH THE MIDWEST. TEMPERATURES WILL AVERAGE AROUND  
10 DEGREES BELOW NORMAL.  
 
MONDAY NIGHT  
ASSESSMENT...MEDIUM CONFIDENCE  
 
MAINLY DRY CONDITIONS WILL BE SEEN ACROSS THE AREA DURING THE  
EVENING HOURS AS THE NEXT STORM SYSTEM APPROACHES FROM THE PLAINS.  
LATE MONDAY NIGHT RAIN WILL BEGIN OVERSPREADING THE AREA WITH THE  
BETTER RAIN CHANCES ACROSS THE WESTERN THIRD OF THE AREA. THE MODEL  
CONSENSUS HAS SLIGHT CHANCE TO LIKELY POPS FOR LATE MONDAY NIGHT.  
 
TUESDAY AND TUESDAY NIGHT  
ASSESSMENT...HIGH CONFIDENCE ON RAIN OCCURRING. LOW CONFIDENCE ON  
AMOUNTS AND SEVERE POTENTIAL  
 
THE NEXT STORM SYSTEM MOVES THE MAIN LOW NORTH THROUGH THE PLAINS.  
EASTERLY FLOW OVER MOST OF THE AREA WILL KEEP COOL TEMPERATURES FOR  
MUCH OF THE DAY. TEMPERATURES MAY WARM LATE IN THE AFTERNOON SOUTH  
OF I-80 AS WINDS TURN MORE SOUTHEAST.  
 
THE STRONGEST FORCING AND THUS BETTER CHANCES FOR RAIN ARE GENERALLY  
ACROSS CENTRAL IOWA. THERE IS SOME GOOD FORCING OCCURRING INTO  
NORTHEAST IOWA WHICH SHOULD HELP ENHANCE RAIN POTENTIAL WEST OF THE  
MISSISSIPPI. THE MODEL CONSENSUS HAS CHANCE TO LIKELY POPS TUESDAY  
WITH LIKELY POPS TUESDAY NIGHT.  
 
THE LARGE SCALE SHOWS THE GULF WIDE OPEN AND FEEDING DEEP MOISTURE  
INTO THE PLAINS AND MIDWEST. THUS THE HEAVY RAINFALL RISK IS REAL.  
CENTRAL IOWA IS CURRENTLY FAVORED FOR HEAVY RAINFALL BUT RAINFALL  
AMOUNTS OF 1 TO 2 INCHES ARE VERY POSSIBLE ACROSS EASTERN IOWA. THIS  
SITUATION WILL HAVE TO BE WATCHED CLOSELY FOR POSSIBLE HEADLINES.  
 
THE INITIAL COOL TEMPERATURES MEANS THAN RAIN WILL BE SEEN DURING  
THE MORNING AND EARLY AFTERNOON HOURS. AS FORCING INCREASES WITH THE  
APPROACH OF THE UPPER LEVEL PART OF THE STORM SYSTEM, THUNDERSTORMS  
SHOULD BEGIN DEVELOPING BY MID TO LATE AFTERNOON AND CONTINUE INTO  
TUESDAY NIGHT.  
 
REGARDING THE SEVERE POTENTIAL; THE SHEAR IN THE ATMOSPHERE IS  
TREMENDOUS. HOWEVER, THE ATMOSPHERE ONLY BECOMES MARGINALLY UNSTABLE  
DUE TO THE COOL TEMPERATURES. THUS WHILE THERE IS A SEVERE RISK THE  
WINDOW FOR ANY SEVERE STORMS LOOKS TO BE QUITE NARROW AND CONFINED  
TO THE LATE AFTERNOON AND EARLY EVENING HOURS WITH HAIL BEING THE  
PRIMARY RISK.  
 
A WIND RISK 'MAY' BE POSSIBLE IF STORMS CAN ORGANIZE INTO A LINE  
ACROSS MISSOURI THAT RACES NORTHEAST INTO THE AREA. THE LINE  
SCENARIO IS WITHIN THE REALM OF POSSIBILITIES GIVEN THE MORE  
UNSTABLE ATMOSPHERE ACROSS MISSOURI.  
 
WEDNESDAY ON...  
 
WEDNESDAY  
ASSESSMENT...HIGH CONFIDENCE  
 
QUIET, DRY AND WARMER CONDITIONS WILL BE SEEN ON WEDNESDAY AS HIGH  
PRESSURE MOVES THROUGH THE MIDWEST. TEMPERATURES SHOULD AVERAGE  
ABOVE NORMAL.  
 
WEDNESDAY NIGHT THROUGH SATURDAY  
ASSESSMENT...LOW TO MEDIUM CONFIDENCE  
 
THE MODELS DIVERGE WITH THEIR RESPECTIVE SOLUTIONS. THEY DO SUGGEST  
SOMEWHAT SIMILAR SCENARIOS BUT DIFFER ON THE DETAILS.  
 
ALL FOUR GLOBAL MODELS DEVELOP A BOUNDARY FROM NORTHERN MISSOURI  
INTO CENTRAL INDIANA WEDNESDAY NIGHT. THE FV3 HAS IT AS A SURFACE  
BOUNDARY WHILE THE GFS, CMC GLOBAL AND ECMWF HAVE IT AS AN UPPER  
LEVEL BOUNDARY.  
 
SAID BOUNDARY REMAINS IN PLACE THROUGH THURSDAY BEFORE LIFTING NORTH  
OF THE AREA THURSDAY NIGHT/FRIDAY. ANOTHER STORM SYSTEM THEN DRAGS A  
SURFACE COLD FRONT THROUGH THE AREA IN THE FRIDAY THROUGH SATURDAY  
NIGHT TIME FRAME.  
 
WHILE THE OVERALL SCENARIO IS SIMILAR BETWEEN THE GLOBAL MODELS  
THERE ARE DIFFERENCES IN THE DETAILS REGARDING TIMING OF RAIN AND  
POTENTIAL RAINFALL AMOUNTS. THE MODEL CONSENSUS IS SOMEWHAT BIASED  
TOWARD THE GFS AND CMC SOLUTIONS.  
 
CURRENTLY THE MODEL CONSENSUS HAS CHANCE TO LIKELY POPS WEDNESDAY  
NIGHT AND THURSDAY, MAINLY DRY CONDITIONS THURSDAY NIGHT (DUE TO THE  
CMC GLOBAL), AND THEN SLIGHT CHANCE TO CHANCE POPS FRIDAY THROUGH  
SATURDAY. AREAS SOUTH OF HIGHWAY 30 ARE FAVORED FRIDAY AND FRIDAY  
NIGHT. FOR SATURDAY AREAS SOUTH OF I-80 ARE FAVORED.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)  
ISSUED AT 546 AM CDT SUN MAY 19 2019  
 
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL AFFECT THE TAF  
SITES THIS MORNING. VSBYS WILL DROP WITH ANY STORM. CIGS  
EVENTUALLY LOWER TO MVFR/LCL IFR TODAY INTO THIS EVENING.  
SOUTHWEST TO WEST WINDS INCREASE TO 30 TO 35 KNOTS LATER THIS  
MORNING THROUGH THE AFTERNOON.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 1225 PM CDT SAT MAY 18 2019  
 
A LINE OF THUNDERSTORMS THAT TRACKED THROUGH THE AREA THIS MORNING  
PRODUCED RAINFALL ROUGHLY IN A .25 TO .5 INCH RANGE WITH LOCAL  
HEAVIER TOTALS, BASED ON BOTH RADAR AND SURFACE REPORTS. THE  
RELATIVELY FAST MOVEMENT OF THE HEAVY RAINFALL RATES HAS PREVENTED  
ANY SHORT TERM HYDRO ISSUES. A FLASH FLOOD WATCH IS IN EFFECT FOR  
TONIGHT THROUGH MID MORNING SUNDAY IN ANTICIPATION OF THE NEXT ROUND  
OF POTENTIALLY HEAVY RAINFALL, THAT WILL OCCUR WITH NEARLY SATURATED  
SOIL CONDITIONS NOW IN PLACE.  
 
LATEST TRENDS SUGGEST A BREAK IN THE RAIN IS EXPECTED EARLY THIS  
AFTERNOON, THEN ANOTHER THUNDERSTORM COMPLEX WITH HEAVY RAINFALL  
CURRENTLY OVER KS AND OK WILL PASS THROUGH THE FORECAST AREA LATE  
THIS AFTERNOON INTO OVERNIGHT. THIS WILL HAVE THE POTENTIAL FOR  
WIDESPREAD HEAVY RAIN AND THE LATEST RIVER FORECASTS HAVE THESE TWO  
EVENTS INCORPORATED, WITH EXPECTED RAINFALL TOTALS OF AROUND 1 INCH  
EAST TO 2 INCHES IN THE FAR WEST, WHICH IS A CONSERVATIVE, MIDDLE  
RANGE OF POSSIBILITIES. AS A RESULT, NEW RIVER FORECASTS THIS  
MORNING, INCORPORATING THIS RAINFALL, HAVE MUCH HIGHER LEVELS THAN  
YESTERDAY, ON BOTH TRIBUTARY RIVERS AND THE MISSISSIPPI RIVER, THIS  
HAS RESULTED IN HIGHER LEVELS, NEW FLOODING AND HIGHER CATEGORY  
FLOODING ON AREA RIVERS, AND NUMEROUS FLOOD WARNINGS WENT OUT THIS  
MORNING, AS DETAILED BELOW.  
 
ON THE TRIBUTARY RIVERS: RAPID RISES ARE EXPECTED OVER THE NEXT  
COUPLE DAYS. MODERATE FLOODING IS NOW EXPECTED ON THE WAPSIPINICON  
AT DEWITT. ON THE SKUNK RIVER, SIGOURNEY IS NOW FORECAST TO REACH  
THE UPPER LEVELS OF MODERATE FLOODING AND AUGUSTA REACHES MODERATE  
FLOODING AS WELL. ON THE IOWA RIVER, MARENGO SURGES MUCH HIGHER INTO  
MODERATE FLOODING, WHILE WAPELLO AND OAKVILLE ARE NOW FORECAST TO  
REACH MINOR FLOODING. ON THE CEDAR RIVER, ONLY WITHIN BANK RISES ARE  
EXPECTED. THE ENGLISH RIVER AT KALONA IS NOW FORECAST TO CLIMB INTO  
MODERATE FLOODING. THE DES MOINES RIVER IS ALSO FORECAST TO RISE  
INTO MINOR FLOODING. ON THE ILLINOIS SIDE, WITHIN BANK RISES ARE  
EXPECTED AT FREEPORT, WHILE THE ROCK RIVER WILL RISE ABOVE FLOOD  
STAGE AT MOLINE AND STAY LONGER ABOVE FLOOD STAGE AT JOSLIN. THE LA  
MOINE RIVER AT COLMAR IS FORECAST TO CLIMB SHARPLY, BUT CREST BELOW  
FLOOD STAGE EARLY NEXT WEEK.  
 
ON THE MISSISSIPPI RIVER: FORECASTS HAVE RISEN CONSIDERABLY, NOW  
THAT THIS WEEKEND SYSTEM'S QPF (TOTAL RAIN FORECAST) IS TAKEN INTO  
ACCOUNT. WARNINGS FOR MINOR TO MODERATE FLOODING WERE ISSUED THIS  
MORNING FOR DUBUQUE LD11, DUBUQUE RAILROAD BRIDGE, FULTON, AND LE  
CLAIRE. AT ROCK ISLAND, A HIGHER AND PROLONGED CREST INTO MODERATE  
FLOODING IS NOW EXPECTED. A CHANGE FROM MINOR TO MODERATE FLOODING  
WAS MADE FOR MUSCATINE AND FROM MODERATE TO MAJOR FLOODING ISSUED  
FOR KEITHSBURG AND GLADSTONE. AT BURLINGTON, THE NEW FORECAST HAS A  
HIGHER CREST, NOW CLOSE TO MAJOR FLOODING OCCURRING EARLY NEXT WEEK.  
KEOKUK ROSE FROM MINOR FLOODING TO MAJOR FLOODING, LIKELY DUE TO THE  
CONTRIBUTION OF UPSTREAM TRIBUTARIES. GREGORY LANDING STAYS WITHIN  
MODERATE FLOODING, BUT CRESTS MUCH HIGHER THAN THE PREVIOUS FORECAST.  
 
THESE FORECASTS WILL LIKELY CHANGE SOME AS RAINFALL AMOUNTS AND  
COVERAGE ARE TAKEN INTO ACCOUNT. ANOTHER SYSTEM WITH POTENTIALLY  
HEAVY RAINFALL IS EXPECTED TUESDAY, WHICH MAY RESULT IN ADDITIONAL  
RISES, RENEWED FLOODING OR HIGHER CATEGORY FLOODING AND IS NOT  
INCORPORATED IN THE CURRENT RIVER FORECASTS.  
 

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

 
 

 
 
SYNOPSIS...HAASE  
SHORT TERM...HAASE  
LONG TERM...08  
AVIATION...HAASE  
HYDROLOGY...SHEETS  
 
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