Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 230426
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1126 PM CDT TUE JUL 22 2014

.SYNOPSIS...
ISSUED AT 319 PM CDT TUE JUL 22 2014

LATEST SFC ANALYSIS WAS INDICATING INCOMING COOL FRONT PUSHING ACRS
SOUTHWESTERN WI...EXTENDING SOUTHWESTWARD TO NEAR WATERLOO...CENTRAL
INTO SOUTHWESTERN IA AND BACK ACRS NORTHWESTERN KS. BEST SFC PRESSURE
FALLS STARTING TO MOVE EAST/SOUTHEAST OF THE LOCAL AREA TOWARD NE
IL/LK MI...AND NE MO INTO WEST CENTRAL IL. POOLING SFC DPTS AHEAD OF
THIS FEATURE PUMPING VALUES UP IN THE MID TO UPPER 70S ACRS MUCH OF
THE CWA. STRATOCU AND ELEVATED CONVECTIVE DEBRIS KEEPING AMBIENT
TEMPS DOWN SOME...BUT STILL WIDESPREAD VALUES IN THE MID TO UPPER 80S
WITH A FEW 90S. DESPITE THE AREAS OF CLOUDS...STILL SOME PATCHY
MOSTLY SUNNY LOCATIONS AND HIGH DPTS HELPING HEAT INDICES RISE INTO
THE UPPER 90S TO LOWER 100S IN SEVERAL SPOTS. WILL LET THE HEAT
ADVISORY RIDE THROUGH 7 PM CDT. SFC BASED CAPES RANGING FROM 3000 TO
OVER 5000 J/KG LOCALLY...BUT ALSO NOTED WAS H7 MB TEMPS OF +13 TO
+14C AND STRONG LOW TO MID LEVEL CAPPING ACRS THE AREA. WATER VAPOR
IMAGERY WAS INDICATING THE MAIN VORT MAX ROLLING EAST-SOUTHEASTWARD
ACRS THE SOUTH HALF OF MN ATTM...BUT A SECONDARY LOBE NOTED ACRS
SOUTHWESTERN IA.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM CDT TUE JUL 22 2014

TONIGHT...BESIDES THE CURRENTLY FESTERING ELEVATED SHOWERS AND
STORMS WEST OF THE MS RVR...OF COURSE THE MAIN CHALLENGE WILL BE IF
THE FRONT AND VORTS ALOFT WILL BE ENOUGH TO GENERATE MORE SUBSTANTIAL
CONVECTION LATE THIS AFTERNOON AND EVENING. DEEP SHEAR PROFILES
REMAIN LOCALLY MARGINAL TO RATHER WEAK...WITH BETTER VALUES CLOSE
TO THE MAIN SHORT WAVE ALONG THE IA/MN BORDER AND POINTS NORTHWARD.
ASSESSING MCS FORCING PARAMETERS...TWO MORE FAVORED AREAS OF
DEVELOPMENT OVER THE NEXT 1-3 HRS LOOK TO BE ACRS SOUTHEASTERN THIRD
OF WI INTO NORTHERN IL WITH SOME OF THIS POSSIBLY TAILING WESTWARD
INTO THE DVN CWA/FREEPORT IL TO GENESEO IL AND EASTWARD/. THE OTHER
MAY OCCUR TO THE LEE OF THE SOUTHWESTERN IA VORT LOBE OVER FAR
SOUTH CENTRAL IA INTO NORTH CENTRAL MO...WITH THE POTENTIAL OF SOME
OF THIS ADVECTING INTO THE SOUTHWESTERN DVN CWA THROUGH AT LEAST MID
EVENING. IF THIS CONVECTION WHERE TO BECOME SFC ROOTED...THE HIGH
CAPES IN PLACE WOULD LIKELY FUEL STRONG TO SVR STORMS DESPITE THE
MARGINAL SHEAR IN PLACE WITH BOTH LARGE HAIL AND ESPECIALLY DOWN-
BURST WINDS. IF CONVECTION REMAINS ELEVATED OR STRUGGLES BECAUSE
THE CAP HOLDS...LITTLE SVR THREAT IN THE LOCAL AREA TONIGHT. WILL
KEEP LOW TO MODERATE CHC POPS GOING THIS EVENING BECAUSE OF THIS
POTENTIAL...BUT DOUBTS ARE SETTLING IN AND WONDER IF THE LOCAL AREA
WILL HAVE MUCH MORE THAN JUST ISOLATED ELEVATED SHOWERS/STORMS
AFTER 7-8 PM CDT. POST FRONTAL VEERING IN LLVL FLOW TO COOL/DRY
ADVECT ESPECIALLY AFTER MIDNIGHT...WILL GO WIDESPREAD LOWS IN THE
60S WITH THE HWY 20 CORRIDOR POSSIBLY DIPPING INTO THE LOWER 60S.

WEDNESDAY...IN-BUILDING HIGH PRESSURE AND LLVL NORTH TO NORTHEAST
FLOW TO MAKE FOR A MUCH COOLER AND LOWER HUMIDITY DAY ON WED. HIGHS
MAY BE HELD IN THE MID 70S IN THE FAR NORTHEASTERN CWA...BUT STILL
WARMING INTO THE LOWER 80S SOUTH OF I80. ALL BELOW NORMAL. SOME POST-
FRONTAL CELLULAR CU DEVELOPMENT EXPECTED BY AFTERNOON...BUT CURRENTLY
EXPECT COVERAGE NOT TO RUIN MOSTLY SUNNY WORDING.     ..12..

.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 319 PM CDT TUE JUL 22 2014

QUIET AND DRY CONDITIONS WILL BE SEEN WEDNESDAY NIGHT AND THURSDAY
AS HIGH PRESSURE MOVES THROUGH THE AREA.

THUNDERSTORMS WILL DEVELOP IN WESTERN IOWA ON THURSDAY AFTERNOON AND
GROW UPSCALE INTO A THUNDERSTORM COMPLEX THURSDAY NIGHT. THIS
COMPLEX WILL SLOWLY MOVE INTO THE AREA DURING THE LATE EVENING AND
OVERNIGHT HOURS.

THE THUNDERSTORM COMPLEX THAT DEVELOPS THURSDAY NIGHT WILL SLOWLY
MOVE ACROSS THE AREA ON FRIDAY AND DISSIPATE. BOUNDARIES LEFT OVER
FROM THIS COMPLEX WILL PROVIDE THE FOCUS FOR NEW THUNDERSTORMS
FRIDAY AFTERNOON.

FRIDAY NIGHT ON...
THE MODEL CONSENSUS HAS CHANCE TO LOW END LIKELY POPS ACROSS THE
AREA FRIDAY NIGHT. YET ANOTHER THUNDERSTORM COMPLEX SHOULD DEVELOP
ACROSS IOWA AND MOVE EAST TOWARD THE GREAT LAKES OVERNIGHT.

ON SATURDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO LOW CHANCE POPS
FOR THE DEPARTING THUNDERSTORM COMPLEX.

THE MODELS DIVERGE ON THEIR RESPECTIVE SOLUTIONS FOR SATURDAY NIGHT.
SOME MODELS INDICATE DRY CONDITIONS WITH HIGH PRESSURE MOVING INTO
THE AREA WHILE OTHER SUGGEST THE POSSIBILITY OF NOCTURNAL
THUNDERSTORMS. AS SUCH THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS
FOR THE AREA.

SUNDAY THROUGH MONDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO LOW
CHANCE POPS FOR THE AREA. SOME MODEL SOLUTIONS SUGGEST DRY
CONDITIONS WHILE OTHERS DEVELOP CONVECTION WITH WEAK DISTURBANCES
ALOFT MOVING THROUGH THE AREA.

THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS MONDAY NIGHT AS HIGH
PRESSURE DROPS SOUTH THROUGH THE PLAINS.

ON TUESDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO LOW CHANCE POPS
FOR THE AREA AS ANOTHER WEAK DISTURBANCE ALOFT MOVES THROUGH THE
AREA.    ..08..

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1124 PM CDT TUE JUL 22 2014

COOL FRONT HAS BROUGHT FAIR SKIES AND NORTHWEST WINDS TO THE
TERMINALS. VFR CONDITIONS WILL DOMINATE THE NEXT 24 PLUS HOURS
WITH SOME FAIR WEATHER CUMULUS CLOUDS MID DAY ON WEDNESDAY.
NORTHWEST WINDS OF 5 TO 10 MPH WILL SHIFT TO NORTH AND NORTHEAST
AT 5 TO 10 MPH WEDNESDAY.

&&

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

&&

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...08
AVIATION...NICHOLS





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