000 
FXUS63 KDMX 212005
AFDDSM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
305 PM CDT SAT APR 21 2001

FORECAST CONCERNS WITH TSRA DEVELOPMENT OVERNIGHT AND ASSOCIATED 
RAINFALL...THEN SEVERE WX SUNDAY AFTERNOON INTO SUNDAY NIGHT. 

CURRENTLY...CLDS ACRS THE N KEEPING TEMPS QUITE COOL IN THE 50S 
WHILE SUNNY CONDITIONS IN THE SOUTH HAVE ALLOWED TEMPERATURES TO 
RISE INTO THE 70S.  FRONT ACRS KS AND MO BEGINNING TO PRODUCE A FEW 
SHRA/TSRA AS 850 MB FLOW BACKS INTO THE BOUNDARY.  THIS AREA SHOULD 
CONTINUE TO EXPAND THIS EVENING AS STRONG MOISTURE AND WAA OCCUR.  

AS SFC LOW DEEPENS ACRS E COLORADO TONIGHT...WL SEE MOISTURE 
TRANSPORT AND WAA INCREASE INTO IA ALONG WITH ELEVATED INSTABILITY.  
SHRA/TSRA WL SPREAD NORTHEAST INTO STATE AFTER MIDNIGHT AS BOUNDARY 
MOVES TO THE NORTH.  HAVE MENTIONED HEAVY RAINFALL FAR SOUTHERN 
ZONES BUT RELATIVELY QUICK MOVEMENT SHOULD PRECLUDE WIDESPREAD 
EXCESSIVE AMOUNTS.  BOUNDARY CONTINUES TO MOVE NORTH ON SUNDAY WITH 
WARM SECTOR MOVING INTO CWA.  SHOULD SEE TWO ROUNDS OF PCPN.  ONE 
ROUND WITH WAA EARLY IN THE DAY THEN THE SECOND ROUND WITH 
APPROACHING FRONT LATER IN THE DAY.  HEAVIEST QPF SHOULD FALL IN THE 
WEST AND WL OUTLINE IT IN AN ESF AS STRONG MOISTURE TRANSPORT 
CONTINUES THROUGH THE DAY. INSTABILITY ALSO TO INCREASE THROUGH THE 
DAY WITH AMPLE LOW LEVEL MOISTURE AND COOLING MID LEVELS. SHEAR WILL 
ALSO BE GOOD ALTHOUGH IT DOES BECOME SOMEWHAT UNIDIRECTIONAL LATE.  
EITHER WAY...STAGE WL BE SET FOR ANOTHER ROUND OF SEVERE WEATHER 
TOMORROW AFTERNOON AND NIGHT AS FRONT PASSES THROUGH AND HAVE ADDED 
SVR WORDING TO MOD RISK AREA.  

FRONT TO PASS SUNDAY NIGHT WITH COOL AND BREEZY DAY MONDAY.  SOME 
SPRINKLES NOT OUT OF THE QUESTION AS MOISTURE WRAPS AROUND LOW ON
MONDAY.  CLEARING EXPECTED INTO MONDAY NIGHT WITH TEMPS FALLING INTO 
THE 30S MANY AREAS.  EXTENDED WL BE DRY FOR THE MOST PART ALTHOUGH 
WL MENTION A CHANCE FOR SHOWERS NORTHEAST ON WEDNESDAY AS SHORTWAVE 
IN NORTHWEST FLOW MOVES THROUGH THE GREAT LAKES.  THIS SHOULD DRAG A 
TROF AXIS THROUGH THE STATE WITH BEST DYNAMICS ACRS THE NORTHEAST.

.DSM...NONE

COGIL