000 
FXUS63 KDMX 092114
AFDDSM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
315 PM CST SAT FEB 9 2002

FORECAST CHALLENGES MAINLY WITHIN THE FIRST 24 HOURS AS WINTER STORM 
MOVES ALONG SOUTHERN IA BORDER.  FOCUS ON PCPN TYPE...AMOUNTS AND 
WINDS.  CURRENTLY...SOUTHEAST WINDS ACRS MUCH OF THE CWA TODAY HAVE 
LIFTED TEMPS WELL ABOVE FREEZING WITH ONLY EXCEPTION IN FAR NW 
ZONES.  LIGHT RAIN AND DRIZZLE HAS RECENTLY DEVELOPED ACRS WESTERN IA 
AS MOISTURE ENTRAINS INTO THE SYSTEM.  RAIN CONTINUES TO BE PRIMARY 
PCPN TYPE ACRS THE STATE ALTHOUGH SOME SN HAS MIXED IN ACRS THE NW.  

MODELS HAVE COME MORE IN LINE WITH THE EVOLUTION OF THIS SYSTEM AS 
IT PASSES THE STATE.  BIG QUESTION NOW IS HOW MUCH OF THE QPF WL 
FALL AS RAIN BEFORE TRANSITION TO SNOW.  THIS...IN TURN...WL AFFECT 
FINAL SNOW AMOUNTS.  WITH RAIN/SNOW LINE STILL IN E NEBRASKA...FEEL 
THE SWITCH OVER IS STILL SOME TIME OFF...ESPECIALLY EAST ZONES.  
BUFKIT SOUNDINGS ACTUALLY DONT SWITCH ALO...DSM OR OTM OVER UNTIL 
09Z OR SO.  IN ADDITION...1000MB-850MB PARTIAL THICKNESSES SUGGEST 
TURN OVER WELL AFTER MIDNIGHT IN THESE LOCATIONS.  SOUNDINGS ON THE 
OTHER HAND TEND TO BRING TEMPS TO FREEZING ABOUT 2 TO 4 HOURS 
EARLIER.  IN THE END...HAVE OPTED TO GO CLOSER TO SOUNDINGS AS CAA 
AND DYNAMIC COOLING FROM LIFT SHOULD EVENTUALLY WIN OUT...BUT HAVE 
CUT BACK ON OVERALL TOTALS SLIGHTLY.  NEXT...AS SFC LOW PASSES TO 
THE EAST OVERNIGHT...PRESSURE GRADIENT TIGHTENS RAPIDLY.  SHOULD SEE 
NW WNDS CLIMB QUICKLY PRODUCING CONSIDERABLE BLSN AND NEAR BLIZZARD 
CONDITION...ESPECIALLY FAVORED FLAT AREAS OF WEST CENTRAL TO NORTH 
CENTRAL CWA.  SUSTAINED WINDS OF 20 TO 35 MPH WITH GUSTS OVER 40 
SHOULD NOT BE UNCOMMON AFT 06Z.  SO...AS FAR AS THE ONGOING WARNINGS 
ARE CONCERNED...VERY LITTLE CHANGE WL OCCUR.  EVENTHOUGH SNOW 
AMOUNTS ARE NOT WARNING CRITERIA...THE COMBINATION OF SNOW AND WND 
COULD EASILY PRODUCE NEAR WHITEOUT CONDITIONS.  ACRS THE FAR SE 
WHERE NO HEADLINES CURRENTLY EXIST...WL RAISE A WINTER WX ADVISORY 
LATE TONIGHT AND SUNDAY MORNING FOR SOME ACCUMULATING SNOW BUT 
ESPECIALLY FOR STRONG NW WNDS AND POTENTIAL BLOWING SNOW.

STORM WL SLIDE RAPIDLY EAST ON SUNDAY WITH SNOW COMING TO AN END 
ACROSS THE SE CORNER OF THE CWA.  WNDS WL CONTINUE MUCH OF THE DAY 
ALTHOUGH SHOULD SUBSIDE SOME OUT WEST AS RIDGE AXIS BUILDS INTO THE 
STATE.  RELATIVELY LITTLE SENSIBLE WX AFTER THIS TIME AS SHORTWAVES 
MOVE ALONG IN BROAD NORTHWEST FLOW.  MOST OF THE FORCING AND PCPN 
WITH THESE REMAIN WELL TO THE NORTH.  NEXT MENTION OF PCPN COMES ON 
THURSDAY AS SHORTWAVE GRAZES STATE...ALTHOUGH CHANCES ARENT VERY 
GREAT.  TEMPS TO REMAIN AT OR ABOVE NORMAL.

.DSM...WINTER STORM WARNING TNGT INTO SUN MRNG GENERALLY ALG AND N
        OF KCSQ-KCID LN.
       IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>073-
        081-082
       WINTER WEATHER ADVISORY LATE TONIGHT INTO SUNDAY MORNING
        ACROSS SOUTH CENTRAL IA.
       IAZ074-075-083>086-092>097

COGIL