000
FXUS63 KDVN 021221 AAB
AFDDVN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
621 AM CST MON MAR 2 2015

.UPDATE...
ISSUED AT 619 AM CST MON MAR 2 2015

FORECAST LOOKS TO STILL BE ON TRACK. SOME 4SM VSBYS HAVE FORMED
ACROSS SOUTHERN ZONES AND FAR NORTHERN ZONES. DO NOT EXPECT THIS
TO GET MUCH WORSE THAN THAT. TEMPS ARE ONCE AGAIN FRIGID THIS
MORNING AND WITH THE WIND...SOME BELOW 0 WIND CHILLS HAVE BEEN
OBSERVED.

&&

.SYNOPSIS...
ISSUED AT 235 AM CST MON MAR 2 2015

HIGH PRESSURE WAS LOCATED OVER CENTRAL AND WESTERN IA THIS
MORNING...LEADING TO MOSTLY CLEAR SKIES. A HIGH DECK OF CIRRUS
CLOUDS WAS LOCATED OVER SOUTHERN PORTIONS OF THE AREA. THIS WAS
HELPING TO KEEP TEMPERATURES WARMER ACROSS THAT AREA TONIGHT.
NEARLY ZONAL FLOW ALOFT WILL LEAD TO WARMER TEMPERATURES ACROSS
THE AREA AS WELL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM CST MON MAR 2 2015

MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE NASTY WINTRY MIX
FORECAST FOR LATE MONDAY NIGHT AND INTO TUESDAY. DIFFERENCES IN
GUIDANCE HAVE LEAD TO DIFFICULTIES IN PREDICTING QPF AMOUNTS.
OVERALL SNOW TRANSITIONING TO SLEET AND THEN TO FREEZING RAIN WILL
OCCUR FROM SOUTH TO NORTH DURING THIS PERIOD. CURRENT QPF VALUES
LEADS ONE TO BELIEVE THAT OVERALL SNOWFALL AND ICE ACCUMULATIONS
WILL BE LIGHT.

EXPECT A NICE DAY TODAY BEFORE CLOUDS RETURN TO THE AREA AS WELL
AS MOISTURE. ONSET OF PRECIP APPEARS TO BE BETWEEN 03Z AND 06Z FOR
MOST OF THE AREA. H85 LLJ CONVERGES OVER THE AREA BETWEEN 06Z AND
12Z. THIS WILL LEAD TO THE RAPID DEVELOPMENT OF PRECIP OVER THE
AREA. WITH WAA OCCURRING MOST OF THE PRECIP WILL START AS SNPL AND
QUICKLY TRANSITION INTO PL AND FZRA...ESPECIALLY ALONG AND SOUTH
OF I80. THIS LLJ CONVERGENCE WILL QUICKLY MOVE TO THE EAST. BY
THIS TIME THE EXTENDED FORECASTER BEGINS THEIR PERIOD. DO NOT
THINK THAT MUCH WARM AIR WILL MAKE IT NORTH OF HIGHWAY 30...THIS
MEANS THAT MOSTLY SN WILL FALL WITH POSSIBLY SOME PL. ACCUMULATION
OF SN AND PL LOOK LIKELY IN THIS AREA. THE AM COMMUTE WILL BE
MESSY ACROSS THE AREA WITH THIS MIX.

QPF REMAINS THE MAIN ISSUE WITH THIS FORECAST. HPC QPF IS UNDER
0.1 INCHES FROM 6Z TO 12Z. I CAN SEE THIS OCCURRING...HOWEVER WITH
THE STRONG LLJ I COULD ALSO SEE OUR AMOUNTS BE TOO LOW WITH
MOISTURE CONVERGENCE OVER THE AREA. OF THIS IS THE CASE...IT COULD
GET VERY MESSY FOR THE AM COMMUTE TOMORROW. TOTAL ICE ACCUMS ARE
CURRENTLY 0.05 OF AN INCH WITH SNOW ACROSS FAR N ZONES UNDER 2
INCHES. DO NOT HAVE HIGH CONFIDENCE ON THE THE AMOUNTS. REGARDLESS
AT THIS TIME DECIDED TO SEND A QUICK EMAIL BRIEFING TO OUR PARTNERS
ABOUT THIS...AS WE ARE UNCERTAIN ON AMOUNTS FOR AN ADVISORY.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 AM CST MON MAR 2 2015

TUESDAY WILL SEE RAIN/FREEZING RAIN/SLEET ANS SNOW MOVING OUT OF THE
CWA DURING THE MORNING HOURS...FOLLOWED BY MUCH MORE PATCHY
RAIN...SNOW OR EVEN DRIZZLE IN THE AFTERNOON. TEMPERATURES WILL RISE
THROUGH THE MORNING HOURS...REACHING 32 OR ABOVE NEAR BURLINGTON BY
7 TO 8 AM...THE QUAD CITIES...BY AROUND 10 AM...AND NEAR DUBUQUE BY
NOON. IN ANY CASE...THE THREAT FOR FREEZING RAIN WILL LINGER UNTIL
TEMPERATURES EXCEED 32...THOUGH PAVEMENT TEMPERATURES DURING THE DAY
WILL LIKELY LEAD AIR TEMPERATURES DUE TO INCOMING SHORT WAVE AND
LONG WAVE RADIATION FROM THE BRIGHTNESS OF THE DAY. THIS IS A VAGUE
SCIENTIFIC EXPLANATION...THAT RESULTS IN A HAZARD OF ICY
ROADS...THAT SHOULD NOT LINGER THROUGH THE MORNING VERY LONG. AN
ADVISORY MAY YET BE REQUIRED...BUT WITH QPF SO LOW...UNDER 0.20 FOR
THE TOTAL EVENT IN MOST LOCATIONS...IT MAY FALL MORE INTO AN SPECIAL
WEATHER STATEMENT EVENT.  WE HAVE SENT OUT INFORMATION TO EMERGENCY
MANAGERS CONCERNING THIS POSSIBLE EVENT TO HIGHLIGHT THIS BEYOND A
TYPICAL HWO.

THE LOWER THAN EARLIER EXPECTED QPF IS LARGELY DUE TO THE LLJ
VEERING EAST OF THE CWA QUICKLY TUESDAY MORNING. THIS SHUNTS THE
BETTER MOISTURE AND CONVERGENCE INTO WISCONSIN AND MICHIGAN BY MID
MORNING...WITH DRY MID LEVEL AIR POURING INTO IOWA AS WELL.
THUS...MOST OF THE RAINS WILL END BY MID MORNING IN OUR CWA...AND
TOTAL DAYTIME QPF SHOULD BE ON THE ORDER OF A FEW HUNDREDTHS
SOUTHWEST TO AROUND 0.20 NORTHEAST.

BY AFTERNOON...WEST TO NORTHWEST WINDS WILL QUICKLY SWEEP COLD AIR
BACK ACROSS EASTERN IOWA...AND NORTHWEST ILLINOIS. MODEL SOUNDINGS
SUPPORT PATCHY DRIZZLE...FLURRIES...OR SPRINKLES DURING THIS INITIAL
FEW HOURS OF COLD ADVECTION. WINDS BY TUESDAY NIGHT WILL BE AROUND
20 MPH...WITH GUSTS TO 30...AND WITH TEMPERATURES FALLING TO THE
SINGLE DIGITS TO LOWER TEENS...WIND CHILLS WILL BE ZERO TO -18.
ACTUAL TEMPERATURES WILL STRUGGLE THROUGH THE TEENS WEDNESDAY...THEN
FALL TO THE BITTERLY COLD -10 TO ZERO RANGE FROM NORTH TO SOUTH
WEDNESDAY NIGHT. THIS WILL COMBINE WITH WINDS AROUND 10 MPH TO BRING
WIND CHILLS -15 TO -25...IN OTHER WORDS...WE MAY SEE A WIND CHILL
ADVISORY NEEDED IN MARCH. AFTER A COLD THURSDAY IN THE TEENS AND
THURSDAY NIGHT IN THE SINGLE DIGITS...MILD AIR IS FORECAST BY ALL
MODELS TO SPREAD INTO THE MIDWEST FOR FRIDAY THROUGH SUNDAY.

PACIFIC AIR SHOULD SPREAD EAST ALOFT...WITH LITTLE IN THE WAY OF ANY
MOISTURE AVAILABLE FOR CLIPPER WHICH SHOULD PASS WELL NORTH OF IOWA.
THUS...IF YOU ARE LOOKING FOR HINTS OF SPRING...FRIDAY THROUGH THE
WEEKEND IS WHERE YOU SHOULD FIND HOPE.

ERVIN

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 521 AM CST MON MAR 2 2015

VFR CONDITIONS TO DOMINATE TODAY UNTIL SHORTLY INTO MAR 3. A
WINTRY MIX OF PRECIP WILL MOVE THROUGH ALL OF THE TAF SITES
STARTING BETWEEN 03Z AND 06Z. SNOW WILL TRANSITION TO PL THEN TO
FZRA DURING THE PERIOD. SOME OF THE FZRA COULD BE MODERATE NEAR
THE END OF THE TAF PERIOD. CEILINGS COULD FALL TO IFR AT THE END
OF THE PERIOD WITH THE PRECIP. CID AND DBQ WILL LIKELY NOT SEE
MUCH IF ANY FZRA DURING THIS PERIOD. HOWEVER FOR THE NEXT TAF
ISSUANCE THERE IS A GOOD CHANCE THAT IT WILL BE NEEDED SHORTLY
AFTER 12Z ON MAR 3.


&&

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

$$

UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS