Winter Weather in Missouri, January 17, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
307 AM CST MON JAN 17 2011

.SYNOPSIS...
STRONG WARM AIR ADVECTION TAKING PLACE AS PROFILERS INDICATE 40 KNOT
LOW LEVEL JET RAMMING INTO THE AREA. AS WITH THIS TYPE OF EVENT
DOPPLER RADAR INDICATES SEVERAL BANDS OF SNOW IN THE DVN CWA WITH
WIDESPREAD SNOW BACK TO THE WEST ACROSS MOST OF IA. VISIBILITIES
DOWN TO 1 MILE ALREADY IN SEVERAL SITES. CURRENT TEMPERATURES WERE
IN THE UPPER TEENS TO LOWER 20S. ..HAASE..

&&

.SHORT TERM...TODAY AND TONIGHT...
HEADLINES...HAVE EXPANDED THE WINTER WEATHER ADVISORY SOUTHWARD TO
THE I-80 CORRIDOR FOR SNOW AMOUNTS OF 3-5 INCHES. ADVISORY WILL RUN
UNTIL 9 PM THIS EVENING.

SNOW AMOUNTS FOR THIS EVENT...3 TO 5 INCHES WITH ISOLATED HIGHER
AMOUNTS POSSIBLE FROM I-80 NORTHWARD. AROUND 2 INCHES SOUTH OF I-80
WITH AN INCH OR LESS IN OUR FAR SOUTH. ICE ACCUMULATIONS LESS THAN A
TENTH OF AN INCH IN THE SOUTH.

TODAY...CHALLENGING FORECAST WITH REGARD TO PRECIPITATION TYPES WITH
MAJOR CHANGES TO THE FORECAST. ALL MODELS HAVE COME IN COLDER SO THE
MAJORITY OF THIS EVENT WILL BE IN THE FORM OF SNOW ACROSS THE NORTH
HALF. WARM ADVECTION THIS MORNING WILL BE FOLLOWED BY MAIN TROUGH
SWINGING THROUGH THE REGION THIS AFTERNOON. TWO REASONS FOR GOING
MAINLY SNOW WILL BE EVAPORATIVE COOLING AND DYNAMIC COOLING. BUFKIT
INDICATES WET BULBS STAY BELOW FREEZING FOR MUCH OF THE EVENT WHICH
FAVORS SNOW. CURRENTLY SURFACE DEWPOINTS ARE IN THE TEENS AND 20S
ALL THE WAY DOWN TO OKLAHOMA. THE WARMEST AIR IS FOUND ACROSS THE
WESTERN HALF OF NEBRASKA AND NW KS WHERE TEMPS ARE IN THE 30S TO
AROUND 40. THIS AIRMASS WILL ARRIVE LATE IN THE AFTERNOON OR EARLY
THIS EVENING FOR A BRIEF TIME...BUT AFTER THE BULK OF THE QPF HAS
ALREADY FALLEN. THE MAX TEMPS FORECAST IN THE 30S WILL NOT OCCUR
UNTIL LATE TODAY...OTHERWISE THIS MORNING INTO EARLY AFTERNOON WILL
BE SPENT MAINLY IN THE 20S.

PRECIPITATION TYPES BASED ON FORECAST SOUNDINGS FOLLOW...ALL SNOW
THIS MORNING FOR MUCH OF THE CWA BUT A MIX OF SNOW AND SLEET FAR
SOUTH. ALL SNOW NORTH HALF THIS AFTERNOON WITH A MIX OF FREEZING
RAIN...SNOW AND SLEET IN OUR SOUTHERN CWA THIS AFTERNOON CHANGING TO
PLAIN RAIN AND SLEET FAR SOUTH. THE SNOW SHOULD DIMINISH OR END THIS
EVENING IN THE NORTH FOLLOWED BY PATCHY FREEZING DRIZZLE. IN THE
SOUTH EXPECT PLAIN RAIN THIS EVENING THEN FOLLOWED BY PATCHY
FREEZING DRIZZLE. COLDER AIR BEHIND THE SYSTEM WILL ALLOW MIN TEMPS
TO FALL INTO THE TEENS NW TO MID 20S SE. THE TIMING OF THE
CHANGEOVER TO MIXED PRECIPITATION IS TRICKY AND UPDATES MAY BE
NEEDED.

..HAASE..

.LONG TERM...TUESDAY THROUGH SUNDAY...
THE EXTENDED FORECAST CONTINUES TO BE MAINLY CONCERNED WITH A
VARIABLE ARCTIC AIRMASS WITH SEVERAL CHANCES OF SNOW AS CLIPPERS
PASS THROUGH THE MIDWEST.  TUESDAY MORNING...THE LINGERING FORCING
WILL QUICKLY SHIFT OFF TO THE EAST...ENDING ANY FLURRIES OR VERY
LIGHT SNOW. IN ITS WAKE...SLOWLY FALLING TEMPERATURES SHOULD BE
FOUND THROUGH THE DAY...ALONG WITH RATHER GUSTY COLD CONDITIONS.
LOOK FOR TEMPS IN THE TEENS IN MOST LOCATIONS BY MID TO LATE
AFTERNOON. SOME DRIFTING SNOW IS ALSO LIKELY...BUT WILL LEAVE THIS
OUT OF THE FORECAST FOR NOW AS IT MAY NOT BE SIGNIFICANT ENOUGH TO
CALL IT BLOWING SNOW.

TUESDAY NIGHT SOME PARTIAL CLEARING MAY OCCUR...ENOUGH ALONG WITH
THE CAA TO BRING LOW TEMPERATURES DOWN TO THE -5 TO ZERO RANGE
WEST...TO +5 EAST. WEDNESDAYS RECOVERY LOOKS MEAGER...WITH LIGHT
WINDS UNDER ARCTIC HIGH PRESSURE. UPPER SINGLE DIGITS WEST TO MID
TEENS EAST MAY BE A BIT OPTIMISTIC...BUT UNTIL WE KNOW OUR NEW SNOW
DEPTHS...WE SHOULD NOT GO MUCH COLDER.

WEDNESDAY NIGHT TO THURSDAY...A CLIPPER WILL EITHER HIT...OR PASS
JUST SOUTHWEST OF THE CWA. MODEL ENSEMBLE POPS ARE STILL IN THE
CHANCE RANGE AND WILL GO WITH THIS. IF THE GFS AND NAM ARE CORRECT
ON THE TRACK...WE MAY SEE A FLUFFY SNOW OF SEVERAL INCHES. WHILE THE
ECMWF WOULD SUGGEST A INCH OR TWO ONLY IN THE FAR SOUTH.

BEYOND THIS...MODEL HAVE AGAIN TRENDED COLDER...WITH TEMPS POSSIBLY
BELOW -10 FOR THURSDAY NIGHT AND FRIDAY NIGHT. ANOTHER CLIPPER IS
BEING SUGGESTED TOWARD THE UPCOMING WEEKEND.
..ERVIN..

&&

.AVIATION...
IFR CONDS IN SNOW THIS MORNING AT ALL TAF SITES...MIXED WITH SLEET
AT KBRL. ALL SNOW AT KCID/KDBQ/KMLI THIS AFTERNOON WITH THE SNOW
MIXING WITH FREEZING RAIN AND SLEET AT KBRL. THE SNOW MOVES EAST
THIS EVENING FOLLOWED BY PATCHY FREEZING DRIZZLE. IFR CIGS/VIS IN BR
TONIGHT. SOUTHEAST TO SOUTH WINDS 10-20 KNOTS WITH GUSTS TO NEAR 25
KNOTS TODAY. WINDS BECOMING NORTHWEST 10 TO 15 KNOTS TONIGHT.

..HAASE..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR BENTON-
     BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-
     JOHNSON-JONES-LINN-MUSCATINE-SCOTT.

IL...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR BUREAU-
     CARROLL-HENRY IL-JO DAVIESS-PUTNAM-ROCK ISLAND-STEPHENSON-
     WHITESIDE.

MO...NONE.

&&

HAASE/ERVIN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
359 PM CST SUN JAN 16 2011

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-172200-
BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON-
CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON-
HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL-
WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON-
WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK-
359 PM CST SUN JAN 16 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
ILLINOIS...NORTHWEST ILLINOIS...WEST CENTRAL ILLINOIS...EAST
CENTRAL IOWA...NORTHEAST IOWA...SOUTHEAST IOWA AND NORTHEAST
MISSOURI.

.DAY ONE...THIS AFTERNOON AND TONIGHT

LIGHT SNOW WILL SPREAD INTO EASTERN IOWA AND NORTHEAST MISSOURI
ESPECIALLY AFTER MIDNIGHT. ACCUMULATIONS SHOULD BE AN INCH OR LESS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

FOR AREAS ALONG AND NORTH OF HIGHWAY 30...SNOW WILL CONTINUE THROUGH
MONDAY AFTERNOON...SLOWLY ENDING FROM WEST TO EAST DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS. TOTAL SNOW ACCUMULATIONS SHOULD
RANGE FROM 2 TO 4 INCHES. ALONG THE INTERSTATE 80 CORRIDOR...THE SNOW
WILL MIX WITH AND CHANGE OVER TO SLEET AND FREEZING RAIN DURING
THE DAY ON MONDAY...BEFORE CHANGING BACK TO SNOW BEFORE THE
PRECIPITATION ENDS MONDAY EVENING. SNOW AMOUNTS SHOULD BE 1 TO 3 INCHES.
ALONG HIGHWAY 34 THE PRECIPITATION SHOULD BEGIN AS A WINTRY
MIX...BEFORE BECOMING ALL RAIN DURING THE DAY...AND THEN MIXING
BACK TO SNOW BEFORE ENDING MONDAY EVENING. LITTLE TO NO SNOW
ACCUMULATIONS ARE EXPECTED. THE PRECIPITATION WILL END MONDAY
EVENING...BUT IN ITS WAKE...THERE MAY BE SOME PATCHY FREEZING
DRIZZLE FOR SEVERAL HOURS OVERNIGHT.

MUCH OF THE WEEK AHEAD WILL SEE VERY COLD TEMPERATURES. THERE IS
THE POTENTIAL FOR BITTER WIND CHILL VALUES LATE THURSDAY NIGHT AND
FRIDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT. HOWEVER...REPORTS OF
SNOW AMOUNTS OF AN INCH OR MORE WOULD BE APPRECIATED TONIGHT AND
MONDAY.