Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KDVN 281138
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
638 AM CDT TUE JUL 28 2015

.SYNOPSIS...
ISSUED AT 303 AM CDT TUE JUL 28 2015

AT 3 AM CDT...CONVECTION IS RAPIDLY DEVELOPING AHEAD OF THE NEXT
COOL FRONT WITH A DECENT WARM ADVECTION WING OF STORMS IN IOWA.
TRENDS SUGGEST CONVECTION WILL CONTINUE TO INCREASE INTO THE MID
MORNING HOURS WITH CLOUDS THAT MAY IMPACT TEMPERATURES TODAY.
UPSTREAM DATA SUPPORTS A COOL FRONT THAT MAY BE STRONGER THAN
MOST SOLUTIONS AND ALSO MAY PROVIDE FOR MORE PRECIPITATION AS IT
PASSES TONIGHT. RISK OF SEVERE IS TOO UNCERTAIN AT THIS TIME AS
HEATING WILL BE NEEDED AND FORCING FOR AREA WILL NEED TO OCCUR
THIS EVENING. UPSTREAM ENERGY SUPPORTS COOLER AND DRIER THAT WILL
LAST INTO THIS WEEKEND.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT TUE JUL 28 2015

SHORT TERM FORECAST CONFIDENCE ASSESSMENT...POOR TO VERY POOR OR BELOW
TO WELL BELOW NORMAL. DYNAMIC CONVECTION MAY IMPACT HIGHS TODAY AND
HEAT ADVISORY FOR THE REGION. HIGHS COULD BE OFF BY 5 PLUS DEGREES
IF CLOUDS AND PRECIPITATION IS MORE WIDESPREAD THAN FORECAST FOR TODAY.
THIS RISK WILL BE BETTER KNOWN BY MID TO LATE MORNING AS THE WARM ADVECTION
WING CONVECTION PLAYS IT HAND. STRENGTH AND SPEED OF FRONTAL PASSAGE
SUGGESTS CATEGORICAL POPS WITH MOSTLY MODERATE TO LOWER END HEAVY RAINFALL
TOTALS UP TO 1 TO 1.5 INCHES.

TODAY...HAVE ADDED A ROW OF COUNTIES TO HEAT ADVISORY WITH POOR CONFIDENCE
THOUGH AS TRENDS OF CONVECTION AND PRESSURE FALL/RISE COUPLETS SUGGEST
LESS SUN AND MORE CLOUDS AND PRECIPITATION THAN CURRENT FORECAST HAS
FOR TODAY. AGAIN...THIS TREND SHOULD BE BETTER KNOWN IN THE NEXT 6 PLUS
HOURS. HIGHS HAVE TRIMMED A DEGREE OR TWO IN THE NORTH WITH RISKS OF
FURTHER TRIMMING ALL BUT MAYBE FAR SOUTH IF CLOUDS AND CONVECTION ARE
UNDERDONE. LIKELY LOCATIONS ALONG AND SOUTH OF HIGHWAY 34 WILL SEE HEAT
ADVISORY WITH INDICES UP TO 105F AND LOCALLY POSSIBLY BRIEFLY HIGHER.

TONIGHT...A HEALTHY TO STRONG LINE OF STORMS SHOULD PASS ALL OR MOST
OF THE AREA BY MIDNIGHT OR POSSIBLY AS LATE AS 2 AM. ISOLATED SEVERE
WITH STRONG WINDS TO 60-70 MPH SUGGESTED AS MAIN THREAT. LOCAL RAIN
TOOLS WITH PW/S AOA 2.00 INCHES SUGGEST RAIN TOTALS WITH TRAINING
MAY CAUSE WATER ISSUES. CURRENT TRENDS SUGGEST A PROGRESSIVE NATURE
TO PRECIPITATION WITH MOST AMOUNTS .5 TO 1.5 INCHES LIMITING WATER
ISSUES. HOWEVER...DYNAMIC NATURE OF SYSTEM WITH CURRENT CONVECTION
SUGGEST INTERACTION MAY OCCUR WITH SOME TRAINING RISKS. IF THIS HAPPENS
THEN LOCALLY 3 TO 4 PLUS INCHES MAY OCCUR. AGAIN...THIS WON/T BE KNOWN
FOR AT LEAST 6 PLUS HOURS AND POSSIBLY NOT UNTIL THIS AFTERNOON TO SEE
IF MORNING CONVECTION CREATES A COOL POOL TO FOCUS LATE DAY CONVECTION
ON. MINS LOWER 60S TO LOWER 70S.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 303 AM CDT TUE JUL 28 2015

FORECAST FOCUS ON NEAR NORMAL TEMPERATURES AND DRY THE REMAINDER OF
THE WORK WEEK. THEN THUNDERSTORM CHANCES RETURN THIS WEEKEND.

WEDNESDAY THROUGH SATURDAY...WILL WALK OUT DIMINISHING SHOWERS AND
STORMS WEDNESDAY MORNING IN OUR SOUTHEAST CWA OTHERWISE THIS WILL BE
A QUIET PERIOD. A NORTHWEST FLOW ALOFT AND A SPRAWLING HIGH PRESSURE
SYSTEM WILL PREVAIL. THIS WILL BRING TOLERABLE HUMIDITY AND NEAR
NORMAL TEMPERATURES...WITH HIGHS IN THE LOWER TO MID 80S AND LOWS IN
THE LOWER TO MID 60S.

SATURDAY NIGHT THROUGH MONDAY...THE PATTERN BECOMES A BIT MORE
ACTIVE AS A SERIES OF DISTURBANCES RIDE THE NORTHWEST FLOW.
HOWEVER...CONFIDENCE IS LOW AS OPERATIONAL MODELS DISAGREE ON
PLACEMENT/TIMING OF THESE WAVES AND ANY ASSOCIATED SHOWERS AND
THUNDERSTORMS. FOR NOW THE ALLBLEND HAS CHANCE POPS DURING THIS
ENTIRE TIME FRAME BUT LATER SHIFTS CAN NARROW THE WINDOW OF
OPPORTUNITY FOR CONVECTION IF/WHEN THE MODELS COME INTO BETTER
AGREEMENT. LITTLE CHANGE IN TEMPERATURES EXPECTED BUT HUMIDITY
LEVELS LOOK TO CREEP BACK UP HIGHER.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 635 AM CDT TUE JUL 28 2015

VFR CONDITIONS WITH EPISODES OF MVFR/IFR CONDITIONS IN THUNDERSTORMS
ARE EXPECTED AT ALL THE TERMINALS THROUGH 29/08Z WITH POSSIBLY
STRONG WINDS AOA 35 KTS. AFTER A COOL FRONT PASSES...SKIES WILL
CLEAR AND WINDS SHIFT FROM A SOUTHERLY DIRECTION TO THE WEST AND
NORTHWEST AT 5 TO 10+ KTS.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR DES
     MOINES-HENRY IA-JEFFERSON-KEOKUK-LEE-LOUISA-VAN BUREN-
     WASHINGTON.

IL...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
     HANCOCK-HENDERSON-MCDONOUGH-MERCER-WARREN.

MO...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR CLARK-
     SCOTLAND.

&&

$$

SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...NICHOLS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.