Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 282013
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
313 PM CDT THU MAY 28 2015

.SYNOPSIS...
ISSUED AT 311 PM CDT THU MAY 28 2015

12Z UA ANALYSIS HAD AN 850MB HIGH OVER THE GREAT LAKES AND OHIO
VALLEY. A WEAK LLJ RAN FROM TEXAS INTO EASTERN KANSAS THAT WAS
HELPING TO SUPPORT NOCTURNAL CONVECTION ALONG THE KS/MO BORDER.
SATELLITE TRENDS THROUGH MID AFTERNOON HAS WEAK CONVECTIVE COMPLEXES
FROM WESTERN IOWA INTO MISSOURI. RADAR HAS MAINLY SHOWERS ACROSS
IOWA WITH MORE THUNDERSTORMS THAN SHOWERS ACROSS MISSOURI.

18Z SFC DATA HAS HIGH PRESSURE OVER THE GREAT LAKES WITH AN IMPLIED
FRONT/BOUNDARY FROM THE OHIO VALLEY INTO CENTRAL MISSOURI. DEW
POINTS WERE IN THE 50S FROM THE GREAT LAKES INTO THE NORTHERN PLAINS
WITH 60S FROM THE CENTRAL PLAINS INTO THE OHIO VALLEY ON SOUTH.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CDT THU MAY 28 2015

BASED ON RADAR/SATELLITE TRENDS CONVECTION WILL CONTINUE TO DEVELOP
ACROSS MISSOURI THROUGH LATE AFTERNOON WITH SOME ISOLATED TO
POSSIBLY SCATTERED SHOWERS MOVING INTO THE FAR SOUTH AND SOUTHWEST.
THE LATE ARRIVAL OF THE CONVECTION INTO THE AREA SUGGESTS IT SHOULD
BE IN A DECAYING PHASE BY EARLY EVENING.

THIS EVENING THE BETTER SUPPORT ALOFT STARTS MOVING OUT OF THE
PLAINS SO ISOLATED TO SCATTERED SHOWERS SHOULD BECOME A BIT MORE
NUMEROUS ACROSS THE WESTERN THIRD TO HALF OF THE AREA THROUGH
MIDNIGHT ALONG WITH SOME THUNDERSTORMS.

AFTER MIDNIGHT THE BETTER FORCING/SUPPORT STARTS MOVING THROUGH THE
AREA. THE BETTER COVERAGE OF SHOWERS AND SOME THUNDERSTORMS WILL BE
OVER THE NORTHWEST THIRD OF THE AREA BUT AGAIN SHOULD ONLY BE
SCATTERED IN NATURE. EAST OF THE MISSISSIPPI ISOLATED TO LOW END
SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOULD DEVELOP AFTER
MIDNIGHT.

OVERALL RAINFALL TONIGHT SHOULD GENERALLY BE A TENTH OF AN INCH BUT
SOME AMOUNTS APPROACHING A QUARTER INCH MIGHT BE SEEN IN THE
NORTHWEST THIRD OF THE AREA.

SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOULD BE SEEN ACROSS THE
AREA MONDAY MORNING AS THE BETTER SUPPORT EXITS THE AREA. THE LATE
MORNING AND EARLY AFTERNOON HOURS MAY SEE VERY LITTLE IN THE WAY OF
CONVECTION DUE TO THE LACK OF STRONGER FORCING ALOFT.

BY LATE FRIDAY AFTERNOON...THE MAIN FRONT MOVES CLOSER TO THE AREA
AND THE OVERALL FORCING ALOFT INCREASES. THUS CONVECTION WILL BE ON
THE INCREASE DURING THE PEAK HEATING HOURS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CDT THU MAY 28 2015

THE COLD FRONTAL PASSAGE WILL OCCUR LATE FRIDAY NIGHT THROUGH EARLY
SATURDAY MORNING. WHILE PWAT VALUES WELL ABOVE NORMAL ARE
FORECAST...ALONG WITH CAPE SUFFICIENT FOR STRONG THUNDERSTORMS...WE
WILL BE LACKING A STRONG FORCING MECHANISM...WITH NO DEFINITE SHORT
WAVE PASSING THROUGH THE MIDWEST AT THE TIME OF THE FROPA. I AM
WORRIED THAT WITH AMPLE CAPE...CONVECTIVE TRENDS WILL FORM SMALL
CLUSTERS AND EAT INTO THE HIGHER CAPE VALUES FARTHER SOUTH...AND
WITH STRONGER MID LEVEL WINDS TO THE NORTH...OTHER WIDESPREAD
ACTIVITY MAY TRACK OVER NORTHEAST IOWA TO WISCONSIN. WE HAVE BEEN
ADVERTISING CATEGORICAL POPS...BUT GIVEN THIS UNCERTAINTY ON
COVERAGE...I AM ELECTING TO LOWER POPS TO LIKELY FOR FRIDAY NIGHT.
ISOLATED AMOUNTS OVER 1 INCH ARE LIKELY...BUT WIDESPREAD AMOUNTS
OTHERWISE SHOULD BE A HALF INCH OR LESS.

EARLY SATURDAY...ANY REMAINING SHOWERS WILL EXIT THE AREA. COOLER
AIR WILL ARRIVE SATURDAY MORNING...AND HIGHS WILL LIKELY NOT CLIMB
MORE THAN 10 DEGREES ABOVE MORNING LOWS IN MANY SPOTS. THIS
COMFORTABLE AIR SHOULD LAST THROUGH MUCH OF THE EXTENDED...WITH
HIGHS REMAINING BELOW NORMAL THROUGH MONDAY. BY TUESDAY...WITH LOW
PRESSURE DEVELOPING IN THE PLAINS...AND A VERY WEAK UPPER LOW CUT
OFF OVER THE SOUTHEAST SLIPPING SOUTHEAST...RETURN FLOW SHOULD
ESTABLISH ITSELF. MILDER AIR...AND EVENTUALLY ABOVE NORMAL
TEMPERATURES AND TYPICAL JUNE HUMIDITY...WILL ARRIVE BY MID TO LATE
WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM CDT THU MAY 28 2015

VFR CONDITIONS WILL BE SEEN THROUGH 00Z/29 WITH HIGH AND THEN MID
LEVEL CLOUDS INCREASING ACROSS THE AREA. AFT 00Z/29 VFR CONDITIONS
ARE EXPECTED TO CONTINUE WITH ISOLATED TO SCATTERED SHRA AND
POSSIBLY A TSRA. KCID/KDBQ HAVE SLIGHTLY BETTER CHANCES OF SEEING
A PERIOD OF MVFR CONDITIONS WITH A POTENTIAL TSRA FROM 06Z/29 THROUGH
SUNRISE FRIDAY.


&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...08



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