FXUS63 KDVN 031618
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1018 AM CST THU DEC 3 2009

.UPDATE...
COMPLEX SCENARIO THIS MORNING WITH LARGE DRY SLOT AND CLEARING ENVELOPING
MUCH OF THE FORECAST AREA. NARROW SNOW BANDS IN AREAS OF STEEP MID
LEVEL LAPSE RATES AHEAD OF UPPER VORT OVER NRN PLAINS HAVE ALREADY
PRODUCED REPORTS OF 1 TO 4 INCHES IN CENTRAL AND NRN IA EARLIER
THIS MORNING. THE CLEARING ON VISIBLE SATELLITE IMAGERY HAS
REVEALED NEW SNOW COVER ACROSS IA AND BENTON COUNTY FROM LOW
REFLECTIVITY BANDS EARLIER THIS MORNING. LATEST RADAR AND SURFACE
REPORTS INDICATE SMALL SNOW SHOWERS/FLURRIES PRIMARILY OCCURRING
ALONG THE EDGE OF THE CLEARING FROM VTI THROUGH MUT TO GBG.

STILL ASSESSING POTENTIAL FOR ADDITIONAL MEASURABLE SNOW
ESPECIALLY ALONG THE HIGHWAY 20 CORRIDOR NORTHWARD THIS AFTERNOON
INTO EVENING. THIS IS HERE MID LEVEL INSTABILITY AND FORCING
ALONG TRACK OF UPPER LOW WILL LIKELY PRODUCE ADDITIONAL NARROW
BANDS OF MODERATE SNOW AND POTENTIAL FOR NEAR ADVISORY
ACCUMULATIONS. 4KM HIGH RES WRF WAS ONLY MODEL CLOSE TO HANDLING
THESE FEATURES.

HAVE UPDATED FORECAST FOR SKY COVER TRENDS AS CURRENT DRY SLOT
PUSHES THROUGH LATE THIS MORNING WITH CLOUDS CLOUDS FILLING BACK
IN THIS AFTERNOON. POTENTIAL FOR ADDITIONAL MEASURABLE LIGHT SNOW
LOOKS GREATEST NORTH OF HIGHWAY 30. ALTHOUGH HIGHS KEPT IN THE
30S...MANY SITES MAY HAVE ALREADY SEEN THESE HIGHS WITH SEE STEADY
TO FALLING TEMPERATURES IN THE MID AND UPPER 20S THIS AFTERNOON.

&&

.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH EARLY AFTERNOON AS DRY SLOT
BRINGS TEMPORARY CLEARING OF CLOUD COVER. CLOUDS WILL FILL BACK IN
THIS AFTERNOON AS UPPER LOW OVER NRN PLAINS SWEEPS EASTWARD.
LIGHT SNOW SHOWERS OR FLURRIES WITH CONDITIONS DIPPING INTO MVFR
RANGE WILL BECOME MORE COMMON AT CID AND DBQ BY EARLY AFTERNOON.
MORE WIDESPREAD SNOW SHOWERS WILL DEVELOP MID TO LATE AFTERNOON
WITH PREVAILING CONDITIONS DROPPING INTO MVFR RANGE AT ALL SITES
BUT BRL. DBQ WILL HAVE GREATEST POTENTIAL TO DROP INTO IFR IN THE
23Z TO 06Z RANGE TONIGHT WITH SEVERAL INCHES OF SNOWFALL POSSIBLE.

&&

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

$$

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