Cold in Illinois, January 28 to 29, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
315 PM CST TUE JAN 27 2004

.SHORT TERM...(TONIGHT THROUGH THURSDAY)...AS SNOW MAKING SYSTEM
EXITS THE AREA OFF TO THE EAST...MAIN NEAR TERM FCST CONCERNS ARE
HOW COLD TONIGHT AND ANY NEED OF WIND CHILL ADVISORY. MODELS
ADVERTISING CLIPPER TYPE SYSTEM IN THE MID TERM ON THU FOR NEXT
MAJOR SNOW CHANCE. EXTENDED LOOKS TROUBLING FOR THOSE WHO DONT LIKE
WINTER.

WEAK RIDGE TO TRY AND EDGE OVER THE CWA OVERNIGHT...BUT INCOMING SFC
SECONDARY ARCTIC BOUNDARY TO FOLLOW CLOSE BEHIND TOWARD MORNING.
ALTHOUGH EXPECT CONTINUED WIND DROP OFF WITH INITIAL CLEAR SKIES AND
IN-BUILDING NARROW RIDGE TONIGHT...FOLLOWING BOUNDARY MAY KEEP
ENOUGH OF A WIND CLOSE TO 10 MPH GOING ACRS THE NORTH. WITH
CONTINUED INFILTRATION OF FRIGID AIR OUT OF CENTRAL MN OVER FRESH
AND LOCALLY SUBSTANTIAL SNOW COVER...A SUB ZERO NIGHT LOOKS TO BE
IN STORE FOR MUCH OF THE CWA. THE NORTHERN CWA AND COLD AIR DRAINAGE
VALLEY REGIONS MAY DIP TO NEAR DOUBLE DIGIT VALUES BELOW ZERO
TOWARD MORNING. THUS WITH ONGOING WIND PROCESSES DESCRIBED ABOVE
COMBINING WITH SUCH COLD AMBIENT TEMPS...WILL ISSUE WIND CHILL
ADVISORY FOR TONIGHT AND WED MORNING ACRS ROUGHLY THE NORTHERN THIRD
OF THE CWA. BULK OF THE WIND CHILLS WILL NEAR OR JUST EXCEED THE
-20 F CRITERIA AFTER MIDNIGHT AND THROUGH 9 AM WED MORNING.

NORTHWEST FLOW WILL USHER IN NEXT WEAK DISTURBANCE ON WED...BUT JUST
EXPECT INCREASE IN MID TO HIGH LEVEL STRATUS. AFTER SUCH A COLD
START AND SECONDARY SFC BOUNDARY PASSAGE WITH VEERING SFC WINDS TO
THE NORTHWEST AGAIN(CAA)...HIGHS ACRS THE NORTH WEDNESDAY SHOULD
MAINTAIN IN THE SINGLE DIGITS.

AS ARCTIC INFRINGEMENT LLVL THERMAL GRADIENT MAINTAINS OVER THE CWA
IN NORTHWEST FLOW...WAVE HIGHWAY LOOKS TO SET UP FOR THE ARRIVAL
OF A CLIPPER TYPE SYSTEM BY THURSDAY. WITH EXPECTED FEATURE
STILL OFF PACIFIC NORTHWEST COAST...WILL TAKE SHORT RANGE MODEL ONE
OR TWO MORE RUNS TO FINE TUNE AND HANDLE...BUT POTENTIAL IS THERE.
GFS MOST AGGRESSIVE IN STRENGTH AND SPEED OF INCOMING VORT...WITH
ETA AND OTHER MODELS WEAKER. CANT RULE GFSS VIGOR OUT QUITE YET
WITH EXTENT OF BAROCLINICITY...BUT EVEN A BIT WEAKER SOLUTION AT THE
MOMENT AND GARCIA METHOD SUGGESTS A POTENTIAL OF 1-3 INCHES OVER MUCH
OF THE CWA BY THU EVENING. WILL TREND UP POPS FOR NOW. SFC THERMAL
RECOVER OUT AHEAD OF INCOMING WAVE MAY NOT BE AS ROBUST AS
PREVIOUSLY THOUGHT. LOOKS LIKE AN OVERALL COLD AND RATHER ACTIVE
PERIOD FOR MUCH OF 7-DAY FORECAST.

 &&

.LONGER TERM...(FRIDAY THROUGH TUESDAY)...MEDIUM RANGE MODELS
REASONABLY SIMILAR IN ADVERTISING ANOTHER COLD SHOT-REINFORCING
COLD LLVL ANTICYCLONE OUT OF NORTHERN SASK./MANITOBA DOWN ACRS THE
WESTERN GRT LKS ON FRI BEHIND DEPARTING OH RVR VALLEY SYSTEM.
POTENTIAL IS THERE FOR A GLANCING BLOW OF -15 TO -20 C H85 COLD
POOL. THUS AFTER A PROBABLE SUB ZERO START ON FRIDAY...WITH SNOW
COVER AND RIDGE/LIMITED MIXING, HIGHS NOT TO MAKE IT OUT OF SINGLE
DIGITS. MODELS THEN DIVERGE IN HANDLING OF PHASING AND PROGRESSIVE
NATURE OF INCOMING MAJOR WAVE ENERGY OVER THE WEEKEND. MRF MOST
PROGRESSIVE WITH CENTRAL AND SOUTHERN PLAINS WAVE PHASING AND
INCOMING SYSTEM WITH ACCUMULATING SNOW INTO THE WESTERN CWA BY MIDDAY
SAT...WHILE FAVORED UKMET AND ECMWF MAINTAINS ARCTIC HIGH IN PLACE
LONG ENOUGH TO HOLD OFF INITIAL ISENTROPIC UPGLIDE SNOWS UNTIL MAINLY
SAT NIGHT. MAIN ACCUMULATING SNOW EVENT APPEARS(AGAIN ACCORDING TO
FAVORED UKMET/EURO) TO BE ON SUNDAY. UKMET CONTINUES TO BE OMINOUS IN
POTENTIAL TRACK OF EJECTING SFC LOW OUT OF SOUTHERN PLAINS AND
UPSTREAM UPPER RIDGING CAUSING NORTHWEST DEFLECTION...FOR A MAJOR
WINTER EVENT FOR THE LOCAL CWA. WILL PLAY LINGERING SNOW INTO EARLY
MONDAY...ESPECIALLY IF SLOWEST EURO HAS ITS WAY.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY TONIGHT AND WED MORNING ALONG AND NORTH OF
A VAN HORNE...TO CEDAR RAPIDS...AND TO A CLINTON LINE.
IL...WIND CHILL ADVISORY TONIGHT AND WED MORNING FOR FAR NORTHWEST
IL.
MO...NONE.

&&

12

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
553 AM CST TUE JAN 27 2004

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-281200-
BENTON IA-BUCHANAN IA-BUREAU IL-CARROLL IL-CEDAR IA-CLARK MO-
CLINTON IA-DELAWARE IA-DES MOINES IA-DUBUQUE IA-HANCOCK IL-
HENDERSON IL-HENRY IA-HENRY IL-IOWA IA-JACKSON IA-JEFFERSON IA-
JO DAVIESS IL-JOHNSON IA-JONES IA-KEOKUK IA-LEE IA-LINN IA-LOUISA IA-
MCDONOUGH IL-MERCER IL-MUSCATINE IA-PUTNAM IL-ROCK ISLAND IL-
SCOTLAND MO-SCOTT IA-STEPHENSON IL-VAN BUREN IA-WARREN IL-
WASHINGTON IA-WHITESIDE IL-
553 AM CST TUE JAN 27 2004

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

.DAY ONE...TODAY AND TONIGHT

A WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON TODAY FOR THE
SOUTHEAST HALF OF THE OUTLOOK AREA. AN UPPER LEVEL DISTURBANCE WILL
CONTINUE TO PRODUCE ADDITIONAL SNOWFALL TODAY ACROSS THE ENTIRE AREA.
THE HEAVIEST SNOW WILL BE OVER FAR EASTERN IOWA AND NORTHWEST
ILLINOIS THIS MORNING WHERE AN ADDITIONAL 2 TO 4 INCHES CAN BE
EXPECTED. THE SNOW WILL DIMINISH TO FLURRIES OVER EASTERN IOWA AND
NORTHEAST MISSOURI BY EARLY AFTERNOON...WHILE ADDITIONAL LIGHT SNOW
ACCUMULATIONS WILL CONTINUE OVER NORTHWEST ILLINOIS.

IN ADDITION...WINDY CONDITIONS WILL DEVELOP ACROSS THE AREA AS A
LOW PRESSURE SYSTEM MOVES INTO THE GREAT LAKES AND ARCTIC HIGH
PRESSURE SETTLES IN FROM THE DAKOTAS. THIS WILL RESULT IN BLOWING
SNOW AND BITTER COLD WIND CHILL READINGS. NORTHWEST WINDS WILL
INCREASE TO 20 TO 30 MPH BY AFTERNOON WITH GUSTS AS HIGH AS 35 MPH.
BLOWING SNOW WILL SIGNIFICANTLY REDUCE VISIBILITIES...ESPECIALLY IN
OPEN COUNTRY. ARCTIC AIR WILL SURGE INTO THE AREA WITH TEMPERATURES
FALLING THROUGH THE TEENS IN THE AFTERNOON. THIS WILL RESULT IN WIND
CHILL READINGS AS LOW AS 5 BELOW TO 15 BELOW ZERO BY AFTERNOON.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH MONDAY

TUESDAY THE UPPER LEVEL SYSTEM THAT BROUGHT SNOW TO THE REGION WILL
DRAW EAST OF THE AREA.  IN ITS WAKE STRONG NORTHWEST WINDS ARE
EXPECTED...SUSTAINING BETWEEN 20 AND 30 MPH.  DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS...GUSTS AS HIGH AS 40 MPH ARE ALSO
POSSIBLE.

SNOW WILL BE POSSIBLE THURSDAY AND AGAIN OVER THE WEEKEND. AT THIS
TIME...IT APPEARS THAT SNOWFALL AMOUNTS THURSDAY WILL BE IN THE
RANGE OF 1 TO 2 INCHES. OVER THE WEEKEND...A MORE SIGNIFICANT WINTER
STORM MAY IMPACT THE AREA WITH THE POTENTIAL FOR HEAVY SNOWFALL AND
BLOWING SNOW . IT IS TOO EARLY TO DETERMINE THE TRACK...TIMING OR
ANTICIPATED SNOWFALL AMOUNTS WITH THIS SYSTEM. MORE DETAILED
INFORMATION WILL BE AVAILABLE IN LATER OUTLOOKS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER REPORTS OF SNOWFALL AND SNOW DEPTH AMOUNTS WOULD BE
APPRECIATED TODAY AND TONIGHT.

&&

FOR MORE INFORMATION...REFER TO THE FOLLOWING WEB SITE:

WWW.CRH.NOAA.GOV/DVN  (LOWER CASE)

LE/DLS