FXUS63 KMPX 210949
AFDMSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
345 AM CST FRI NOV 21 2003 

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
COLDER AIR HAS PUSHED ACROSS THE AREA IN THE WAKE OF YESTERDAY'S 
COLD FRONT.  TEMPS TODAY WILL BE MORE TYPICAL OF LATE NOVEMBER. SFC 
HIGH PRESSURE WILL CONTINUE TO SPRAWL ACROSS THE AREA TODAY WITH 
CLOUDS THINNING OUT DURING THE MORNING.  HIGH CLOUDS ARE HOWEVER 
ALREADY INCREASING ACROSS WY AND WILL SRPEAD INTO WESTERN CWA THIS 
AFTERNOON. 

MODELS HAVE BEEN COMING TOGETHER ON A WHOPPER OF A STORM LATER IN 
THE WEEKEND INTO MONDAY AS POWERFUL STORM SURGES NORTHEAST OUT OF 
THE PANHANDLE AREA ACROSS IOWA THEN THRU WISCONSIN.  THIS IS SHAPING 
UP TO BE A LONG DURATION EVENT WITH LGT SNW BREAKING OUT IN WESTERN 
CWA BY EVENING AND THEN SPREADING EAST OVERNIGHT. NICE SUSTAINED 
ISENTROPIC LIFT THRU SATURDAY MAY DEPOSIT A FEW INCHES OF SNOW PRIOR 
TO THE MAIN EVENT.   THE NVD CHARTS ALREADY HAVE NICE AREA OF LIFT 
OF 40 TO 60MB BY 12Z SAT...WITH ISENTROPIC SURFACES BEGINNING TO 
SATURATE. AVN AND ETA VERY SIMILAR ON TRACK OF SFC LOW AS IT EJECTS 
NORTHEAST...BUT THE AVN IS SOMEWHAT FASTER.  BOTH MODELS GENERATE 
MASSIVE AMOUNTS OF QPF AND SNOW WITH VERY STRONG AND SUSTAINED 
VERTICAL MOTION.  RAPID INCREASE IN PWATS AS GULF OPENS UP AND 
POWERFUL LOW LVL JET TRANSPORTS MOISTURE NORTH.  COULD BE SOME 
THUNDER AS WELL AS K INDEX APPROACHES 30 IN NE IA/S WI.  IF MODELS 
PAN OUT THERE ISN'T MUCH THAT ISN'T DARN NEAR PERFECT FOR AT LEAST A 
FOOT OF SNOW.  TRACK OF SURFACE LOW AND DEEPENING UPPER TROF ARE 
NEAR IDEAL WITH EXTREMELY TIGHT S SHAPED THERMAL RIBBON.  MID AND 
AND LOW LVL THICKNESS VALUES ALSO VERY NICE.  EXTREMELY TIGHT 
PRESSURE GRADIENT WILL ALSO MAKE THIS A WIND JAMMER.  WILL LIKELY 
NEED WINTER STORM WATCH FOR ENTIRE CWA FOR SUNDAY INTO MONDAY. 
 
&&

.LONG TERM...13Z MON THRU THU
FOCUS OF EXTENDED PERIOD ON ONGOING WINTER STORM EXPCD TO DMSH ACRS 
AREA ON MON.  AS DISCUSSED ABV...EXTENDED MODELS APPEAR TO BE 
ZEROING IN ON SOLUTION WHICH WOULD CARRY SIGNIFICANT SNOWFALL ACRS 
MUCH OF CWA SUN INTO SUN NGT.  THE TRACKS ARE VERY SIMILAR...BUT THE 
AVN IS ABOUT 12 HRS FASTER.  LEANING TWD SLIGHTLY SLOWER SOLUTION 
WHICH WOULD KEEP SNOWFALL OCCURRING LONGER ACRS CWA ON MON.  IN 
ADDITION...SIGNIFICANT PRES GRADIENT WL RESULT IN BLOWING SNOW 
PERSISTING THRU MUCH OF MON.  SYSTEM PULLS OFF TO THE EAST MON NGT 
WITH DMSHG WNDS.  WITH POTENTIAL FOR WIDESPREAD FRESH 
SNOWCOVER...TEMPS LKLY TO BE COLDEST OF SEASON...BUT WARM AIR 
ADVECTION CLDS ALREADY STREAMING IN FM WEST WL SLOW TEMP PLUMMET 
SOMEWHAT.  CONSISTENCY BTWN GFS AND CANADIAN MODEL SHOWING WEAK TROF 
PUSHING INTO AREA TUE...SO WL ADD SML POPS FOR -SN OVER ENTIRE CWA 
FOR NOW...AND ENSEMBLE POPS DO SHOW SML POTENTIAL.  REST OF EFP 
UNCHANGED...BUT UNSETTLED WX WL PERSIST REST OF WEEK.
  
&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.

$$
BAP/MBK