000
FXUS63 KDVN 122342
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
642 PM CDT WED MAR 12 2014

.SYNOPSIS...
ISSUED AT 225 PM CDT WED MAR 12 2014

RADAR AND SURFACE REPORTS INDICATED THE WEAK NW TO SE TROUGH AXIS...
EMBEDDED IN THE CYCLONIC FLOW AROUND THE DEPARTING SURFACE LOW OVER
PA...CONTINUED TO PRODUCE FLURRIES OR LIGHT SNOW SHOWERS OVER NW IL
INTO FAR EAST CENTRAL IA AT MID AFTERNOON. THE CONVERGENCE ALONG
THIS AXIS WAS ALSO BEING ENHANCED BY SECONDARY PSEUDO COLD FRONT
THAT MARKED THE LEADING EDGE OF MUCH COLDER AND DRIER AIR ARRIVING
ON NE WINDS OUT OF WI AND LAKE MI. TO THE WEST...A WEAK RIDGE OF HIGH
PRESSURE REACHED FROM EASTERN NEB ACROSS NW IA INTO MN. IN THE UPPER
LEVELS...A TROUGH AXIS WAS OVER THE GREAT LAKES AND OHIO VALLEY
ALLOWING A POOL OF COLD AIR AT 850 MB TO DIP SOUTH OUT OF CANADA
INTO THE GREAT LAKES AND UPPER MS VALLEY. OUT WEST...AN UPPER RIDGE
OVER THE NORTHERN ROCKIES AND WESTERN CANADA WAS BEING UNDERCUT BY A
CUT OFF LOW OVER CA INTO SOUTHERN NV.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM CDT WED MAR 12 2014

TEMPERATURES ARE THE SHORT TERM CHALLENGE AS THE PROGRESSIVE UPPER
LEVEL PATTERN SENDS OUR BRIEF SHOT OF WINTER AIR EASTWARD LATE
TONIGHT. AN AXIS OF MOISTURE AND WARM ADVECTION ALONG THE 850 MB
BAROCLINIC AXIS FROM EASTERN ND INTO WESTERN IA WILL TRANSITION EAST
ACROSS THE FORECAST AREA TONIGHT. THIS SHOULD SEND A LARGE AREA OF
MVFR LEVEL STRATOCU...THAT SET UP IN THIS AXIS OF WARM ADVECTION
OVER THE MO VALLEY AND UPPER MS VALLEY TODAY...EASTWARD THROUGH THE
FORECAST AREA TONIGHT. SOME CLEARING WILL BE POSSIBLE ONCE THE
DIURNAL CLOUDS DISSIPATE OVER EASTERN IA...OTHERWISE TONIGHT LOOKS
TO BE MOSTLY CLOUDY. THIS SHOULD PREVENT TEMPERATURES FROM TANKING
OVER THE SNOW COVER AS NORMALLY WOULD BE EXPECTED WITH THE LIGHT
WINDS AND LOW DEWPOINTS. HAVE THUS STAYED CLOSER TO WARMER GUIDANCE
MINS FROM THE LOWER TEENS NORTH TO THE MID 20S SOUTH. THERE REMAINS
A REMOTE CHANCE FOR LIGHT PRECIPITATION...MOST LIKELY FLURRIES...IN
THIS PERIOD OF WARM ADVECTION LATE TONIGHT...BUT THIS LOOKS TOO LOW
OR INSIGNIFICANT TO INCLUDE IN THE FORECASTS AND HAVE LEFT OUT.

THURSDAY...DEVELOPING SOUTHWEST WINDS...SUNSHINE...AND 850 MB
TEMPERATURES WARMING TO ROUGHLY 2 TO 4 DEG C WILL POINT TOWARD
ANOTHER MILD MARCH DAY. A LIMITING FACTOR WILL BE THE MOIST SOIL
CONDITIONS AND LINGERING SNOW COVER OVER THE FAR NORTH AND THE NEWER
STRIP OF SNOW EVIDENT ON VISIBLE SATELLITE LOOPS ACROSS NE MO...FAR
SE IA INTO W CENTRAL IL. LOOKING BACK AT VERIFICATION FROM OUR
MONDAY WARM-UP...WIDESPREAD MID 40S TO MID 50S LOOK LIKELY...WHICH IS
A FEW DEGREES WARMER THAN THE PREVIOUS FORECAST...BUT IS IN LINE
WITH 12Z MOS GUIDANCE. IF IT WAS NOT FOR THE RECENT RAIN AND
SNOW...READINGS CLOSER TO 60 WOULD BE POSSIBLE IN THE SOUTHWEST.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 225 PM CDT WED MAR 12 2014

GENERALLY DRY WITH NEAR NORMAL TEMPERATURES WHICH WILL SEEM MILDER
DUE TO OUR RECENT PERIOD OF QUITE SEASONABLY COLD WEATHER.

OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH LITTLE SENSIBLE
WEATHER ISSUES UPSTREAM. ENERGY OFF PACIFIC POORLY HANDLED WHICH WILL
TAKE A COUPLE OF MORE DAYS TO BETTER ASCERTAIN. RUN TO RUN CONTINUITY
AND INTER MODEL VARIANCE IS LARGE. CONSISTENCY SUPPORTS A 70/30 BLEND
OF GFS TO THE HI-RES-ECMWF. TEMPERATURES MANY DAYS COULD REQUIRE
ADJUSTMENTS DEPENDING ON AMOUNT OF MARCH SUNSHINE RECEIVED WITH
LOW DEWPOINTS. MINS MAY ALSO BE A CHALLENGE WITH DECOUPLING CAUSING
COLDER NIGHTS.

THURSDAY NIGHT...PRE-FRONTAL WARM AIR ADVECTION WITH SW WINDS OF 5 TO
10+ MPH TO LIMIT LOWS MOSTLY ABOVE FREEZING. SOME LOCAL TOOLS SUGGEST
LOWS IN SOUTH SECTIONS MAY STAY AROUND 40 DEGREES FOR LATER SHIFTS
DESPITE A MOSTLY CLEAR SKY.

FRIDAY...WEAK FRONT TO PASS WITH NW WINDS INCREASING TO 10 TO 25 MPH
AND BLUSTERY. DEEP BL MIXING SHOULD RESULT WITH MARCH SUNSHINE AND
HIGH TEMPERATURES SHOULD RISE NICELY TO UPPER 40S NORTH TO UPPER 50S
SOUTH. LATER SHIFTS SHOULD CONSIDER SOME HIGHS SOUTH SECTIONS TO NEAR
60 DEGREES. FRIDAY NIGHT...WINDS TO BECOME LIGHT AND CURRENT FORECAST
MAY REQUIRE LOWERING MINS BY 3 PLUS DEGREES WITH A DECENT FROST SUGGESTED.

SATURDAY...INCREASING CLOUDS WITH ANOTHER COLD FRONT TO ARRIVE THAT
SHOULD LIMIT HIGHS WITH STRENGTH AND TIMING A QUESTION FOR LATER SHIFTS.
POOR CONFIDENCE ON HIGHS WITH STRONG GRADIENT OF LOWER 40S NORTH TO
UPPER 50S SOUTH SECTIONS. SATURDAY NIGHT... LOW POPS OF LIGHT SNOW WITH
UPPER LOW PASSING TO SOUTH AS COLD FRONT MOVES SOUTH. AGAIN BELOW AVERAGE
CONFIDENCE DUE TO LARGE TIMING AND TRACK VARIANCES. TRAJECTORY SUGGESTS
LITTLE OR NO PRECIPITATION DUE TO MODEST FORCING AND GULF CLOSED LIMITING
MOISTURE. LOWS MAY NEED RAISING A FEW DEGREES IF MORE CLOUDS OCCUR.

SUNDAY AND MONDAY...BACK DOOR COLD FRONT TO KEEP HIGHS UPPER 30S TO
MID 40S WITH RISK OF LIGHT SNOW OR MIX OF SNOW AND RAIN WITH WEAK PASSING
UPPER DISTURBANCES. LOWS MOSTLY IN 20S WITH SOME UPPER TEENS POSSIBLE
MONDAY AM. TEMPERATURES THESE WILL BE 5 TO 10 DEGREES BELOW NORMAL FOR
MID MARCH.

TUESDAY AND WEDNESDAY...WARMER...BUT POOR CONFIDENCE ON STRENGTH AND
TIMING OF THE WARM AIR DEVELOPING OUT WEST. HIGHS 40S AND LOWER 50S
MAY BE 10-15 DEGREES OR MORE TOO COLD IF STRONG SOUTH WINDS DEVELOP
AHEAD DEVELOPING PACIFIC TROUGH. THIS SHOULD BE BETTER KNOWN IN THE
NEXT 1-2 DAYS. SOME LOCAL TOOLS SUPPORTS HIGHS WELL INTO 60S MAY BE
POSSIBLE IF LEE SIDE TROUGH DOES DEVELOP IN THE PLAINS. MOSTLY DRY
TO DRY STILL SUGGESTED BUT TRACK OF DISTURBANCES ARE WIDELY VARYING
AT THIS TIME. KEPT LOW POPS DUE TO TRACK OF WARM FRONT AND SFC LOW
COULD IMPACT AREA WHICH AGAIN NEXT COUPLE DAYS WE WILL KNOW MORE BUT
ANY AMOUNTS SHOULD AGAIN BE LIGHT UNTIL GULF OF MEXICO OPENS BRINGING
IN MUCH HIGHER DEWPOINTS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 631 PM CDT WED MAR 12 2014

A RIDGE OF HIGH PRESSURE WAS LOCATED OVER CENTRAL IOWA WITH A TROF
JUST TO THE WEST NEAR THE MISSOURI RIVER. SCATTERED TO BROKEN
CLOUDS BASED AOA 4KFT WERE LOCATED EAST OF THE RIDGE INTO
NORTHWEST ILLINOIS. A FEW SNOW SHOWERS WERE ASSOCIATED WITH THE
CLOUDS EAST OF THE MISSISSIPPI RIVER...BUT THESE SHOWERS ARE
EXPECTED TO DISSIPATE OVER THE NEXT SEVERAL HOURS. FOR TONIGHT
MAINLY VFR CONDITIONS AREA EXPECTED. LATE TONIGHT A NARROW BAND
OF CLOUDS BASED AROUND 2KFT WILL MOVE THROUGH WITH THE SURFACE
RIDGE. AT THIS TIME IT APPEARS THESE CLOUDS WILL STAY NORTH OF
HIGHWAY 30. THURSDAY WILL ALSO SEE VFR CONDITIONS WITH SOUTH WINDS
VEERING TO THE SOUTHWEST DURING THE AFTERNOON AS THE TROF MOVES THROUGH.

&&

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

$$

SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...NICHOLS
AVIATION...DLF