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000
FXUS63 KDVN 121735
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1235 PM CDT SUN MAY 12 2013

.SYNOPSIS...
ISSUED AT 337 AM CDT SUN MAY 12 2013

GREAT LAKES UPPER LEVEL LOW PRESSURE SYSTEM IS PRODUCING STRONG
NORTH-NORTHWEST FLOW ACROSS THE REGION WITH AN AMPLIFIED RIDGE
HOLDING ACROSS THE WESTERN U.S. AT THE SURFACE...HIGH PRESSURE IN
THE NORTHERN PLAINS IS DROPPING SLOWLY SOUTHEASTWARD TOWARD THE
AREA. A COOL AND VERY DRY CANADIAN AIR MASS REMAINS IN PLACE
FOLLOWING YESTERDAYS COLD FRONTAL PASSAGE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CDT SUN MAY 12 2013

ONLY CONCERN IN THIS FORECAST TIME FRAME IS THE THREAT OF FROST
AGAIN LATER TONIGHT. CONS FOR FROST INCLUDE DEVELOPMENT OF WEAK
850MB WAA TONIGHT AND THE POTENTIAL FOR CIRRUS CLOUDS TO MOVE INTO
THE AREA OVERNIGHT. PROS FOR FROST DEVELOPMENT INCLUDE SURFACE
RIDGE PROGGED TO BE IN THE AREA AROUND 06Z WITH LIGHT WINDS...AND
VERY DRY AIR MASS THAT SHOULD COOL QUICKLY THIS EVENING AS WINDS
LIGHTEN BEFORE SUNSET. AT THIS POINT WILL MENTION THE FROST THREAT
IN THE FORECAST BUT HOLD OFF ISSUING A HIGHLIGHT AT THIS TIME.

HIGH TEMPS TODAY WILL REMAIN ON THE SEASONALLY COOL SIDE...THOUGH
LIGHTER WINDS AND MORE SUNSHINE THAN SATURDAY SHOULD MAKE FOR A
NICER DAY OUTDOORS.  WOLF

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 337 AM CDT SUN MAY 12 2013

MONDAY AND MONDAY NIGHT THE WARM AIR ADVECTION ALOFT
STRENGTHENS...WHICH SHOULD ALSO BRING SOME MID LEVEL MOISTURE INTO
THE AREA AS WELL. THIS MAY PRODUCE SOME WARM AIR ADVECTION WING
PRECIPITATION DURING THE AFTERNOON AND EVENING...MAINLY ACROSS THE
NORTHEAST WHERE IT APPEARS THE MODELS PUT TOGETHER ENOUGH MOISTURE
WITH THE BEST WAA. HIGHS TEMPS MONDAY WILL STILL BE RELATIVELY
COOL COMPARED TO TODAY...BUT IN THE 60S TO LOW 70S. LOWS MONDAY
NIGHT IN THE 50S TO REFLECT THE ONGOING WARM AIR ADVECTION.

TUESDAY WILL BE DRY AND VERY WARM. 500MB RIDGING ALONG WITH
SOUTHWEST MID LEVEL FLOW WILL BRING VERY WARM 850MB TEMPERATURES
OF 18-24C...DEPENDING ON THE MODEL AND TIMING. MODELS ARE
DEPICTING THAT THIS FORMS A STRONG CAP OVER THE SURFACE...WITH
COOLER SURFACE TEMPERATURES AND HIGHER LOW LEVEL DEWPOINTS. HAVE
SOME DOUBTS ABOUT THIS AS THE SOUTHWEST SURFACE FLOW AND EXPECTED
MOSTLY SUNNY CONDITIONS SHOULD ALLOW FOR DEEPER MIXING THAT THE
MODELS ARE SHOWING...AND HAVE GONE WITH THE WARMEST OF GUIDANCE.
IF WE WERE TO MIX ALL THE WAY TO 850MB...WE COULD BE LOOKING AT
LOW 90S...BUT HAVE SOME DOUBTS WE WOULD GET QUITE THAT WARM AS WE
ARE GOING TO HAVE AT LEAST SOME MID AND HIGH LEVEL CLOUD COVERAGE
TO SUPPRESS THE HEATING.

TUESDAY NIGHT A COLD FRONT SAGS INTO THE AREA...AND THEN STALLS
OVER THE AREA THROUGH AT LEAST WEDNESDAY OR WEDNESDAY
NIGHT...DEPENDING ON THE MODEL. INITIALLY HAD SOME CONCERNS FOR
POTENTIAL SEVERE WEATHER WITH THIS FRONT...BUT THE TIMING NOW
LOOKS LESS FAVORABLE...WITH THE BETTER DYNAMICS TOO FAR NORTH OR
SOUTH. TEMPERATURES TO BE NEAR NORMAL THROUGH THE PERIOD.

THURSDAY THROUGH SATURDAY WILL BE AN ACTIVE TIME FRAME WITH THE
FRONT INITIALLY SAGGING SOUTH OF THE AREA THURSDAY...BUT POSSIBLY
SERVING AS A FOCUS FOR AN MCS THURSDAY NIGHT WHICH MAY AFFECT A
PORTION OF OUR AREA. THEN...A NEW STORM SYSTEM FORMS OUT IN THE
PLAINS AS AN UPPER LEVEL TROUGH MOVES ACROSS THE ROCKIES ON
FRIDAY...AND THIS SYSTEM SHOULD MOVE TOWARDS THE AREA SATURDAY.
PRECIP CHANCES RIGHT NOW LOOK FAIRLY HIGH FOR SATURDAY...BUT WOULD
NOT BE SURPRISED TO SEE THESE SHIFT TO LATER IN THE WEEKEND.
..LE..

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1229 PM CDT SUN MAY 12 2013

CLEAR TO MOSTLY CLEAR SKIES AND VFR CONDITIONS THROUGH AT LEAST 13/18Z.
NORTHWEST WINDS OF 10-20 KTS WILL BECOME LIGHT AND VARIABLE TONIGHT
AS SURFACE HIGH PRESSURE MOVES ACROSS THE REGION. WINDS WILL SHIFT TO
THE SOUTH AND SOUTHWEST AT 5-10 KTS BY MID MORNING AS THE SURFACE HIGH
SLIDES EAST.

NICHOLS

&&

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

$$

SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...LE
AVIATION...NICHOLS