177  
FXUS63 KDVN 262342  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
542 PM CST SUN FEB 26 2017  
   
..00Z AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 248 PM CST SUN FEB 26 2017  
 
A WEST TO SOUTHWEST BREEZE GUSTED OVER 30 MPH DURING THE EARLY  
AFTERNOON, AND BROUGHT MILDER AIR INTO THE REGION. EARLY AFTERNOON  
TEMPERATURES RANGED FROM THE LOW 40S TO LOW 50S. CLOUDS WERE ON  
THE INCREASE OVER THE SOUTHWEST THIRD OF IOWA, INTO WESTERN  
ILLINOIS.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 248 PM CST SUN FEB 26 2017  
 
SHORT TERM FORECAST ISSUES INCLUDE CONSIDERATION OF LIGHT  
PRECIPITATION OVER PARTS OF THE FORECAST AREA INTO THIS EVENING,  
AS WELL POTENTIAL FOR FOG.  
 
IN THE NEAR TERM, A ROBUST CU FIELD CONTINUES TO DEVELOP ALONG A  
WEAK MOISTURE CONVERGENCE AXIS FROM SOUTHERN IOWA TO NEAR THE QUAD  
CITIES. MOST HIGH-RES MODELS SUGGEST SOME LIGHT RAIN/SPRINKLES  
DEVELOPING DURING THE LATE AFTERNOON, MAINLY ALONG AND SOUTH OF  
INTERSTATE 80. THIS IS SUPPORTED BY RECENT RADAR TRENDS.  
CHANNELED VORTICITY MOVING INTO THE AREA SHOULD HELP LIGHT  
PRECIPITATION CONTINUE AFTER SUNSET. THE 18Z 12KM WRF IS LINGERING  
THIS PRECIPITATION AFTER MIDNIGHT, WITH COOLING NEAR SURFACE TEMPS  
ALLOWING FOR SOME LIGHT SNOW. CONFIDENCE IN THIS SCENARIO PLAYING  
OUT IS LOW, AND ONLY HAVE A MENTION OF SCATTERED SPRINKLES  
THROUGH EARLY EVENING. OVERNIGHT, THE WEAK CONVERGENCE ZONE IS  
FORECAST TO LIFT SLOWLY NORTH ACROSS THE FORECAST AREA. DO NOT  
BELIEVE WIDESPREAD DENSE FOG IS GOING TO HAPPEN, AS THE MORE  
FAVORABLE LOW LEVEL MOISTURE DOES NOT LOOK TO BE COINCIDENT WITH  
THE CONVERGENCE, BUT HAVE MATCHED NEIGHBORS WITH A MENTION OF  
PATCHY FOG AFTER MIDNIGHT.  
 
FOR MONDAY, WAA WILL CONTINUE AHEAD OF THE NEXT WAVE SET TO  
ARRIVE MONDAY NIGHT. EXPECT AN EVEN MILDER DAY ACROSS THE AREA,  
WITH HIGHS IN THE UPPER 40S NORTH TO UPPER 50S SOUTH.  
   
LONG TERM
 
(MONDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 248 PM CST SUN FEB 26 2017  
 
AN ACTIVE WEATHER PATTERN WILL BE SEEN OVER THE NEXT 7 DAYS WITH A  
WARMING TREND THE FIRST PART OF THE WEEK. COOLER TEMPERATURES WILL  
BE SEEN THE SECOND HALF OF THE WEEK BUT TEMPERATURES SHOULD  
GENERALLY AVERAGE ABOVE NORMAL.  
 
A RIVER FLOOD WATCH HAS BEEN ISSUED FOR PARTS OF THE MAIN STEM  
MISSISSIPPI. REFER TO THE HYDRO SECTION FOR INFORMATION ON AREA  
RIVERS.  
 
STRONG RETURN FLOW WILL USHER MOISTURE BACK INTO THE AREA MONDAY  
NIGHT. AS FORCING INCREASES AFTER SUNSET, ISOLATED TO SCATTERED RAIN  
SHOWERS WILL DEVELOP. FORCING WILL INCREASE FURTHER AFTER MIDNIGHT  
WITH A PASSING UPPER LEVEL DISTURBANCE THAT HAS THE POTENTIAL TO  
DEVELOP SOME ISOLATED THUNDERSTORMS.  
 
ON TUESDAY, ISOLATED TO SCATTERED RAIN SHOWERS WILL BE SEEN ACROSS  
THE AREA DURING THE MORNING AS A SLIGHTLY STRONGER STORM SYSTEM  
MOVES NORTHEAST FROM THE SOUTHERN PLAINS. TUESDAY AFTERNOON, RAIN  
SHOWERS WILL INCREASE IN AREAL COVERAGE AND ISOLATED TO SCATTERED  
THUNDERSTORMS WILL ALSO DEVELOP AS THE STORM SYSTEM MOVES INTO THE  
AREA.  
 
AREAS SOUTH OF A KIRKSVILLE, MO TO STERLING, IL LINE HAVE THE BEST  
CHANCES OF SEEING THUNDERSTORMS TUESDAY AFTERNOON AND EVENING.  
HOWEVER, ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE ENTIRE  
AREA TUESDAY AFTERNOON.  
 
TUESDAY NIGHT INTO WEDNESDAY THE STORM SYSTEM WILL MOVE EAST OF THE  
AREA. COLDER AIR BEING PULLED IN BEHIND THE STORM WILL ALLOW SNOW TO  
MIX WITH THE RAIN LATE TUESDAY NIGHT INTO WEDNESDAY MORNING BEFORE  
ENDING DURING THE AFTERNOON. MUCH COOLER CONDITIONS WILL BE SEEN  
ACROSS THE AREA ON WEDNESDAY WITH TEMPERATURES NEAR NORMAL.  
 
WEDNESDAY NIGHT ON...  
 
QUIET AND DRY CONDITIONS LOOK TO BE IN STORE WEDNESDAY NIGHT AS HIGH  
PRESSURE MOVES THROUGH THE AREA AHEAD OF AN APPROACHING CLIPPER TYPE  
SYSTEM. TEMPERATURES SHOULD BE CLOSE TO NORMAL.  
 
ON THURSDAY, A WEAK CLIPPER TYPE SYSTEM WILL MOVE THROUGH THE AREA  
BRINGING A THREAT OF LIGHT SNOW OR A RAIN/SNOW MIX. MOISTURE IS  
LIMITED AND THE BETTER FORCING IS NORTH OF THE AREA SO ANY SNOW THAT  
OCCURS SHOULD BE A DUSTING AT BEST.  
 
THURSDAY NIGHT THROUGH SATURDAY NIGHT THE MODEL CONSENSUS HAS DRY  
CONDITIONS FOR THE AREA AS HIGH PRESSURE MOVES THROUGH THE MIDWEST.  
THERE IS A WEAK DISTURBANCE MOVING THROUGH THE FLOW ALOFT AROUND  
FRIDAY THAT MAY OR MAY NOT PRODUCE SOME PRECIPITATION. RETURN FLOW  
DEVELOPING FRIDAY NIGHT WILL RESULT IN TEMPERATURES ABOVE NORMAL FOR  
SATURDAY.  
 
ON SUNDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS OVER  
MAINLY THE EASTERN HALF OF THE AREA AS ANOTHER STORM SYSTEM MOVES  
THROUGH THE AREA. THERE ARE DIFFERENCES BETWEEN THE MODEL SOLUTIONS  
WHICH COULD DELAY THE ARRIVAL OF THE PRECIPITATION UNTIL SUNDAY  
NIGHT. TEMPERATURES SUNDAY WILL AVERAGE WELL ABOVE NORMAL.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)  
ISSUED AT 523 PM CST SUN FEB 26 2017  
 
MAIN FOCUS IS WITH FOG POTENTIAL. MORE GUIDANCE ON BOARD WITH FOG  
DEVELOPMENT LATE TONIGHT THROUGH MONDAY AM, ESPECIALLY FROM  
AROUND MLI THROUGH BRL. SPRINKLES/LIGHT SHOWERS HAVE AIDED IN  
MOISTENING OF BOUNDARY LAYER IN THESE AREAS WITH DEW POINTS IN  
THE UPPER 20S TO LOWER 30S. ALSO, CLEARING SKIES LATER TONIGHT  
AND LIGHT WINDS AHEAD OF A DEVELOPING WARM FRONT WILL LEAD TO  
A FAVORABLE FOG SETUP. HAVE TRENDED CONDITIONS DOWN FROM PREVIOUS  
TAFS WITH IFR VIS/CIGS AT BRL AND MLI LATE TONIGHT THROUGH MID  
MORNING MONDAY. LIFR/VLIFR CONDITIONS ARE BEING SUGGESTED AT MLI  
AND BRL BY SEVERAL PIECES OF GUIDANCE, BUT CONFIDENCE NOT THERE  
JUST YET AND PREFER TO TREND TOWARD SUCH A SCENARIO. I HAVE KEPT  
A PERIOD OF MVFR VISIBILITIES AROUND DAYBREAK AT CID AND DBQ.  
SOME GUIDANCE IS SHOWING IFR TO POSSIBLY EVEN LIFR DEVELOPING INTO  
CID TOWARD MID MORNING AHEAD OF THE ADVANCING WARM FRONT, BUT NOT  
AS MUCH MODEL CONSENSUS THUS TOO LOW OF CONFIDENCE TO INCLUDE ANY  
LOWER CONDITIONS.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 248 PM CST SUN FEB 26 2017  
 
RAIN EXPECTED THIS WEEK COMBINED WITH WARMER TEMPERATURES WILL ADD  
ADDITIONAL WATER TO AREA RIVERS. THIS ADDITIONAL WATER WILL THEN  
COMBINE WITH ROUTED FLOW COMING FROM UPSTREAM TO HELP PUSH RIVER  
LEVELS HIGHER. INDIVIDUALS WITH INTERESTS ALONG AREA RIVERS SHOULD  
PAY ATTENTION TO WEATHER AND RIVER FORECASTS OVER THE NEXT 7 TO 10  
DAYS.  
 
IOWA TRIBUTARY RIVERS...  
 
IOWA TRIBUTARY RIVERS WILL SEE RISES OVER THE NEXT 7 TO 10 DAYS,  
ESPECIALLY THE WAPSIPINICON, CEDAR, AND IOWA RIVERS. SEVERAL  
LOCATIONS ARE FORECAST TO APPROACH FLOOD STAGE. THE CEDAR RIVER NEAR  
CONESVILLE IS EXPECTED TO CREST AROUND 0.5 FEET ABOVE FLOOD STAGE  
EARLY THIS WEEK. HOW MUCH RAIN OCCURS THIS WEEK AND HOW QUICKLY THE  
SNOW MELTS ACROSS NORTHERN IOWA WILL BE CRITICAL FACTORS IN  
DETERMINING HOW HIGH RIVER LEVELS WILL GET.  
 
MISSISSIPPI RIVER...  
 
THE OVERALL TREND OF THE FORECAST FOR THE MISSISSIPPI RIVER HAS BEEN  
CONSISTENT. AS A RESULT OF THIS CONSISTENCY, CONFIDENCE HAS  
INCREASED TO THE POINT THAT RIVER FLOOD WATCHES HAVE BEEN ISSUED FOR  
PORTIONS OF THE MISSISSIPPI RIVER. ADDITIONAL RIVER FLOOD WATCHES  
FOR OTHER PARTS OF THE MISSISSIPPI RIVER ARE POSSIBLE OVER THE NEXT  
3 DAYS.  
 
PREDICTED RAINFALL LATER THIS WEEK AND HOW MUCH SNOW WILL MELT UP  
NORTH ARE NOT ACCOUNTED FOR IN THE CURRENT RIVER FORECASTS. THE FLOW  
INPUT FROM THE WISCONSIN RIVER, WHICH WILL BE CONSIDERABLE, HAS BEEN  
SLIGHTLY DELAYED BUT WILL BE GETTING INTO THE MISSISSIPPI RIVER  
BASIN THIS WEEK.  
 
HOW MUCH RAINFALL OCCURS THIS WEEK AND HOW MUCH OF THE SNOW UP NORTH  
MELTS WILL BE KEY FACTORS IN DETERMINING RIVER LEVELS ON THE  
MISSISSIPPI OVER THE NEXT 10 TO 14 DAYS.  
 
NORTHWEST ILLINOIS TRIBUTARY RIVERS...  
 
THE PECATONICA, ROCK, AND GREEN RIVERS ARE STILL FORECAST TO REMAIN  
BELOW FLOOD STAGE. HOWEVER, THESE FORECASTS DO NOT INCLUDE PREDICTED  
RAINFALL THIS WEEK. HOW MUCH RAIN OCCURS THIS WEEK WILL BE IMPORTANT  
IN DETERMINING RIVER LEVELS IN NORTHWEST ILLINOIS OVER THE NEXT 7 TO  
10 DAYS.  
 

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

 
 

 
 
SYNOPSIS...RP KINNEY  
SHORT TERM...RP KINNEY  
LONG TERM...08  
AVIATION...MCCLURE  
HYDROLOGY...08  
 
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