Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KDVN 222100
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
300 PM CST MON DEC 22 2014

.SYNOPSIS...
ISSUED AT 110 PM CST MON DEC 22 2014

AN ELONGATED AREA OF LOW PRESSURE WAS CENTERED OVER NE SD THIS
AFTERNOON...WITH A NEW LOW FORMING OVER S OK. AN UPPER LEVEL TROF
WAS AIDING IN MOVING THE LOW OVER OK TO THE NE AND ADVECTING WARM
AIR INTO OUR AREA. AN IMPRESSIVE 175 KT JET AT H3 WAS MOVING ON
SHORE IN THE PACIFIC NW. THIS JET WILL HELP TO DIG THE TROF THAT
IS IN OUR AREA DEEPER. CURRENT RADAR SHOWS A SMALL HOLE IN
PRECIPITATION MOVING INTO THE AREA FROM THE SOUTH. THIS WILL MOST
LIKELY BE SHORT-LIVED AS ANOTHER VORT MAX ADVECTS IN FROM THE
SOUTH.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 110 PM CST MON DEC 22 2014

MAIN FORECAST CONCERN FOR THE FORECAST PERIOD IS THE LOW PRESSURE
THAT IS FORECAST TO MOVE DIRECTLY OVER THE CWA TOMORROW. FOR DAYS
THE MODELS HAVE FORECAST THIS LOW AND NOW THE SENSIBLE WEATHER
FROM THIS EVENT LOOKS TO BE ALL RAIN.

TONIGHT ANOTHER BAND OF RAIN WILL MOVE INTO THE AREA FROM THE
SOUTH. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THIS BAND MOVING
INTO THE AREA OVERNIGHT TONIGHT LEADING TO AROUND 0.3 INCHES
ACROSS THE AREA...WITH SOME AREAS SEEING SLIGHTLY HIGHER
AMOUNTS...ESPECIALLY ALONG AND EAST OF THE MISSISSIPPI RIVER. LOW
PRESSURE WILL BE ALMOST DIRECTLY OVER THE CWA AROUND 12Z BEFORE IT
LIFTS TO THE NORTH DURING THE DAY. ONCE THE LAST BAND OF PRECIP LEAVES
THE AREA TOMORROW AM IT APPEARS THAT EVERYWHERE EXCEPT FOR FAR NW
ZONES WILL BE DRY TOMORROW WITH TEMPS ABOVE FREEZING. AS FAR AS
PRECIP IN THE NW GOES...COLD AIR WILL TRY TO MAKE ITS WAY INTO THE
AREA. LOOKING AT H92 TEMPS...THE GFS IS ABOUT +2C...THE ECMWF IS
ABOUT +4C AND THE NAM IS AT OR JUST BELOW 0. BELIEVE THE NAM IS
STILL EXHIBITING A LOW LEVEL MOIST AND COLD BIAS DUE TO ITS
MISREPRESENTED SNOW COVER ACROSS THE AREA. SO AT THIS TIME BELIEVE
THAT ALL WE WILL SEE IS RA ACROSS THE AREA.

AS FAR AS TEMPERATURES GO...KEPT TEMPERATURES WARMER TONIGHT WITH
THE WAA ASSOCIATED WITH THE SURFACE LOW ADVECTING OVER THE AREA.
THIS MEANS THAT WE SHOULD STAY ABOVE FREEZING AT THE SFC AND
ALOFT...LEADING TO RAIN. ALLBLEND HAD A GOOD IDEA ON LOWS
TONIGHT...TWEAKED FAR NE ZONES UP A DEGREE OR TWO FROM IT.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 110 PM CST MON DEC 22 2014

THE OVERALL FLOW PATTERN ACROSS NORTH AMERICA WILL BE UNDERGOING A
CHANGE OVER THE NEXT WEEK. WHEN THIS IS COMBINED WITH AN ACTIVE
WEATHER PATTERN...RUN TO RUN MODEL VARIABILITY WILL BE HIGHER THAN
NORMAL.

TUESDAY NIGHT THE LOWER ATMOSPHERE IS NEARLY SATURATED BUT THE
OVERALL FORCING IS WEAK BETWEEN THE DEPARTING SYSTEM AND THE
APPROACHING SYSTEM. AS A RESULT...THE NORTHWEST THIRD OF THE AREA
WILL SEE RAIN SLOWLY MIXING WITH SNOW DURING THE EVENING.

AFTER MIDNIGHT...FORCING BEGINS TO SLOWLY INCREASE AS THE NEXT
SYSTEM APPROACHES THE OHIO VALLEY. A RAIN/SNOW MIX WILL SLOWLY
EXPAND ACROSS THE AREA WITH RAIN CHANGING TO LIGHT SNOW ACROSS THE
WESTERN HALF AS COLDER AIR GETS PULLED DOWN FROM THE NORTH.

WEDNESDAY...FORCING INCREASES CONSIDERABLY AS THE STORM SYSTEM MOVES
UP INTO WESTERN OHIO. LIGHT SNOW WILL CONTINUE MAINLY WEST OF A
DUBUQUE IA TO KIRKSVILLE MO LINE WITH A RAIN/SNOW MIX EAST OF THERE.
AS COLDER AIR GETS PULLED FURTHER SOUTH WEDNESDAY AFTERNOON...THE
RAIN/SNOW MIX WILL CHANGE OVER TO ALL SNOW EXCEPT FOR THE EXTREME
EASTERN PARTS OF BUREAU/PUTNAM COUNTIES. TEMPERATURES DURING THE DAY
WILL BE ABOVE FREEZING.

THE RAIN/SNOW MIX ACROSS BUREAU/PUTNAM COUNTIES WILL CHANGE OVER TO
ALL SNOW WEDNESDAY EVENING WITH DRY CONDITIONS ELSEWHERE. DRY
CONDITIONS ARE THEN EXPECTED LATE WEDNESDAY NIGHT ACROSS THE ENTIRE
AREA AS THE STORM SYSTEM MOVES INTO SOUTHEAST CANADA.

THE MAIN QUESTION IS HOW MUCH SNOW ACCUMULATION CAN BE EXPECTED FROM
TUESDAY NIGHT THROUGH WEDNESDAY EVENING. TEMPERATURES NEAR FREEZING
TUESDAY NIGHT AND ABOVE FREEZING ON WEDNESDAY WILL CUT DOWN ON THE
OVERALL AMOUNTS. TAKING THIS INTO CONSIDERATION...OVERALL SNOWFALL
AMOUNTS WILL BE A DUSTING ACROSS THE AREA. BUREAU AND PUTNAM
COUNTIES MAY SEE A BIT MORE THAN A DUSTING BUT AMOUNTS WILL BE LESS
THAN AN INCH OF ACCUMULATION.

QUIET AND DRY CONDITIONS WILL BE SEEN ACROSS THE AREA ON THURSDAY AS
HIGH PRESSURE QUICKLY MOVES THROUGH THE MIDWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL.

THURSDAY NIGHT ON...
THE MODEL CONSENSUS HAS QUIET AND DRY CONDITIONS THURSDAY NIGHT AS
THE NEXT STORM SYSTEM MOVES NORTHEAST FROM THE PLAINS. LOW
TEMPERATURES WILL BE ABOVE NORMAL.

FRIDAY INTO FRIDAY NIGHT THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS
ACROSS THE NORTHWEST THIRD OF THE AREA AND NORTHEAST HALF OF THE
AREA RESPECTIVELY. THE NEXT STORM SYSTEM WILL PASS TO THE NORTH AND
WEST OF THE AREA KEEPING TEMPERATURES CONSIDERABLY ABOVE NORMAL FOR
FRIDAY. THE ARRIVAL OF THE STRONG COLD FRONT HAS BEEN DELAYED UNTIL
FRIDAY AFTERNOON/EVENING. MOISTURE AND FORCING IS LIMITED BUT SOME
RAIN MAY BE SEEN DURING THE DAYLIGHT HOURS ON FRIDAY AND POTENTIALLY
A RAIN/SNOW MIX FRIDAY NIGHT BEFORE ENDING.

SATURDAY THROUGH MONDAY THE MODEL CONSENSUS HAS DRY CONDITIONS FOR
THE AREA. ANOTHER STORM SYSTEM IS PROGGED TO PASS TO THE SOUTH AND
EAST OF THE AREA OVER THE WEEKEND. TEMPERATURES SHOULD AVERAGE CLOSE
TO NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1138 AM CST MON DEC 22 2014

WITH THE CURRENT SYSTEM MOVING THROUGH THE AREA...MAIN AVIATION
CONCERNS WILL BE DUE TO VSBY AND CEILING ISSUES. AS THE -RA MAKES
ITS WAY IN HERE SITES ARE GOING TO IFE AND EVEN LIFR SOONER THAN
PREVIOUSLY FORECAST. EXPECT THE SITES TO STAY DOWN...ESPECIALLY IF
THERE IS PRECIP AT THEM. PRECIP IS EXPECTED TO WANE THIS AFTERNOON
PROVIDING A BRIEF IMPROVEMENT IN VSBYS AND EVEN SOME CEILINGS. AT
THIS TIME DID NOT INCLUDE THAT IN THE FORECAST AS TIMING AND
CERTAINTY OF IMPROVEMENTS IS UNKNOWN AND LOW. NO FREEZING PRECIP
IS EXPECTED THROUGH THE TAF PERIOD.


&&

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

$$

SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...08
AVIATION...GIBBS





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.