Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 240453
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1153 PM CDT THU APR 23 2015

.SYNOPSIS...
ISSUED AT 307 PM CDT THU APR 23 2015

SFC HIGH PRESSURE AXIS OVER THE MISSISSIPPI VALLEY REGION/MIDWEST
BROUGHT CLEAR SKIES AND LIGHT WINDS TO E IOWA/W ILLINOIS TODAY. THE
LOW-LEVEL ATMOSPHERE IS STILL EXTREMELY DRY WITH DEWPOINTS IN THE
TEENS. AS OF 3 PM...THE RH AT THE DAVENPORT AIRPORT IS EVEN LOWER
THAN YESTERDAY AT 16 PERCENT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 307 PM CDT THU APR 23 2015

THIS EVENING AND TONIGHT...SFC WINDS WILL DECOUPLE UNDERNEATH THE
HIGH PRESSURE AXIS BUT LIGHT SE WINDS WILL DEVELOP NEAR OR AFTER
MIDNIGHT WHICH WILL CAUSE TEMPS TO REMAIN STEADY OR SLOWLY RISE.

HOWEVER...WITH VERY DRY AIR IN PLACE AND CLEAR SKIES FOR THE FIRST
HALF OR SO OF THE NIGHT...TEMPS WILL FALL RAPIDLY THROUGH MIDNIGHT.
THEREFORE...ISSUED A FROST ADVISORY FROM 1 AM CDT TO 8 AM CDT...FOR
LOWS IN THE LOWER TO MIDDLE 30S...OVER THE NORTHEAST PORTION OF THE
FORECAST AREA WHICH DOES INCLUDE THE QUAD CITIES METRO AREA.

FRIDAY...BREEZY CONDITIONS RETURN AS PRESSURE GRADIENT STRENGTHENS
OVER THE MIDWEST. SE FLOW BETWEEN 15-20 MPH WITH GUSTS NEAR 25-30
MPH IS EXPECTED THROUGH THE DAY.

MID-LEVEL NEGATIVE OMEGA AND ASSOCIATED CLOUDS WILL OVERSPREAD THE
AREA VIA WARM AIR AND MOISTURE ADVECTION DURING THE EARLY TO MID
MORNING. LOW-LEVELS WILL BE SLOW TO SATURATE AS DEWPOINTS HAVE BEEN
IN THE TEENS THE PAST FEW DAYS. SFC DEWPOINT DEPRESSIONS ARE STILL
FORECAST TO BE GREATER THAN 10 F BY 00Z/SATURDAY WHICH SUPPORTS THE
ISOLATED TO SCT SHOWERS AND NOT WIDESPREAD RAINFALL. HAVE 30-50 POPS
IN THE GRIDS FRI AFTN...HIGHEST OVER WESTERN CWA. MANY AREAS WILL
PROBABLY NOT RECEIVE MEASURABLE RAIN. THE WESTERN FORECAST AREA
STANDS THE BEST CHANCE TO RECEIVE A FEW HUNDREDTHS TO UP TO A TENTH
OF AN INCH.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 307 PM CDT THU APR 23 2015

MODELS ARE NOW CONSISTENT ON DRAWING A MOIST AIRMASS NORTH OVER
THE CWA...WITH DYNAMICS VERY TYPICAL FOR A MODERATE STRENGTH
WINTER CYCLONE. OUR CWA WILL BE IN THE MAIN PATH OF THE
DEFORMATION ZONE FORCING...THUS A WIDESPREAD RAIN IS A CERTAINTY.
I HAVE ADJUSTED THE POPS TO THE 75 TO 90 PERCENT RANGE FOR LATE
FRIDAY NIGHT THROUGH SATURDAY MORNING...AND THROUGH AFTERNOON IN
THE EASTERN 1/2. THE STABLE SATURATED AIRMASS SHOULD BE DOMINATED
BY A PERSISTENT LIGHT TO MODERATE RAIN...BUT WITH THE WARM SECTOR
OVER MISSOURI CLOSE AT HAND...SOME EMBEDDED RUMBLES APPEAR LIKELY
IN THE SOUTH 1/2 LATE FRIDAY NIGHT AND SATURDAY MORNING. AMOUNT
SHOULD BE SOLIDLY IN THE 0.50 TO 0.75 RANGE FOR MOST OF THE
CWA...WITH SOME LOCATIONS POSSIBLY SEEING OVER 1 INCH IN THE
SOUTHERN 2/3RDS...AND SOME NORTHERN LOCATIONS POSSIBLY SEEING
UNDER 1/2 INCH.

WINDS FRIDAY NIGHT AND SATURDAY WILL BE STRONG FROM THE EAST TO
SOUTHEAST...SUSTAINED AROUND 20 MPH...GUSTING OVER 30 AT TIMES. THAT
WILL COMBINE WITH THE RAIN AND CLOUDS...TO KEEP TEMPERATURES MAINLY
IN THE 40S THROUGH THE WET PERIOD. ASSUMING THE RAIN ENDS IN THE
AFTERNOON...THE SOUTH MAY CREEP BACK TO THE LOWER 50S IN THE
AFTERNOON SATURDAY. IN ANY CASE...IT WILL BE A WEEKEND TO SPEND
INDOORS THROUGH SATURDAY.

SUNDAY THROUGH THE END OF NEXT WEEK APPEARS COOLER THAN NORMAL...BUT
OTHERWISE DRY AND PLEASANT. THE NORTHWEST FLOW WILL KEEP THE REGION
BELOW NORMAL...BUT DEEP DAILY MIXING SHOULD ALLOW FOR MILD DAYS AND
COOL NIGHTS.
ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1147 PM CDT THU APR 23 2015

VFR CONDITIONS WITH INCREASING MID/HI CLOUDS OVERNIGHT AND ESPECIALLY
FRIDAY AHEAD OF NEXT STORM SYSTEM FRIDAY NIGHT. LIGHT WINDS TONIGHT
WILL SHIFT TO THE SOUTHEAST AT 5 TO 10 KTS AFTER MIDNIGHT AS THE SURFACE
HIGH MOVES EAST. SKIES WILL BECOME BKN-OVC BY 24/14Z ALL TERMINALS WITH
CEILINGS DROPPING FROM AOA 10K AGL TO AOB 6K AGL BY 24/22Z. SCATTERED
LIGHT SHOWERS AFTER 24/19Z ARE HANDLED AS A PROB30 WORDING. CONTINUED
RISKS OF PRECIPITATION AOA 25/02Z WITH MVFR CONDITIONS POSSIBLE BY LATE
EVENING.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FROST ADVISORY UNTIL 8 AM CDT FRIDAY FOR CEDAR-CLINTON-DELAWARE-
     DUBUQUE-JACKSON-JONES-MUSCATINE-SCOTT.

IL...FROST ADVISORY UNTIL 8 AM CDT FRIDAY FOR BUREAU-CARROLL-HENRY IL-
     JO DAVIESS-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WHITESIDE.

MO...NONE.

&&

$$

SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...ERVIN
AVIATION...NICHOLS


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