194 
FXUS63 KTOP 022103
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
300 PM CST SUN JAN 2 2000

...SNOW AMOUNTS AND TEMPERATURES MAIN FORECAST CHALLENGES NEXT
   FEW DAYS...

FAST WEATHER CHANGES TO OCCUR OVER THE CWA NEXT 24 TO 36 HRS AS 
FAST MOVING/INTENSE H7/H5 VORT MAX EJECTS FROM THE SRN ROCKIES INTO 
THE CNTRL US. WATER VAPOR SATL LOOP SHOWS THIS SYSTEM MOVING ACROSS
AZ ATTM...CLOSE TO MODEL FCSTS AT 18Z. SFC FRONTAL BOUNDARY 
STATIONARY ATTM FROM SERN MO INTO ERN OK WITH VERY TIGHT MOISTURE 
GRADIENT ON EITHER SIDE OF FRONT AS DEW POINTS GO FROM THE 20S INTO 
THE 60S IN A 50 MILE WIDE CORRIDOR. THIS LOW LEVEL MOISTURE SOURCE 
CAUSES SOME CONCERNS FOR EVENTUAL SNOW/PCPN AMOUNTS FOR MONDAY AS 
SFC/H85 LOW DEEPENS OVER NW OK/SCENT KS 12Z MON. THIS SHOULD ALLOW 
FOR SOME NORTHWARD MOVEMENT OF THIS MOISTURE SOURCE...BUT H85 FLOW 
QUICKLY BECOMES MORE SWLY AND WLY DURING THE MORNING AS SYSTEM PULLS 
INTO MO. STILL SHOULD SEE SOME OF THIS HIGHER MIXING RATIO/H85 DEW 
POINTS CONTRIBUTE TO ENHANCE PCPN/SNOW AMOUNTS OVER ECENT KS MON AFTN 
INTO MON NITE.

WILL BASE FCST ON COMP BETWEEN AVN/ETA MODELS. BOTH SHOW H85 LOW 
NEAR P28 AT 12Z MON...THEN QUICKLY MOVE H85/SFC LOW INTO SWRN/ECENT 
MO DURING THE AFTN. THIS MOVEMENT...ALONG WITH EJECTING H5 VORT 
MAX...SHOULD BE FAVORABLE TO GENERATE LIGHT TO MOD SNOW OVER MOST 
OF THE FA. FEEL WITH THE TRACK OF THE SFC LOW AND H5 VORT 
CENTER/DEFORMATION ZONE THAT ECENT ZONE HAS THE BEST CHANCE OF SEEING 
SOMEWHAT HEAVIER SNOW (2-4). 

SYSTEM QUICKLY MOVES OUT OF THE ERN CWA BY 06Z TUE...WITH FAIRLY 
COLD AIRMASS TO FOLLOW IN THE STORMS WAKE. WILL END PCPN FROM W TO 
E ERLY MON NITE...THEN GO MSUN AND COLD FOR TUES. 
  
.TOP...NONE.

BB