Severe Thunderstorm Warning 106, NWS Aberdeen, SD

AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
425 PM CDT SAT JUL 14 2001

MAIN FCST CHALLENGE IS BOUNDARY THAT HAS SAGGED A BIT FURTHER SOUTH
AND EAST DURING DAY. DWPTS CONT TO POOL NICELY ALONG FEATURE...AND
APPROACHING 7H VORT SHOULD ENSURE THAT CONVECTION CURRENTLY FIRING
ACROSS WRN CWA WILL REMAIN THROUGH EVENING. BIG CONCERN IS HOW FAR
EAST TSRA WILL PUSH. LATEST RUC...AS WELL AS AVN AND 18Z MESO-ETA
SHOWS TROUGH/BOUNDARY RETREATING BACK TO THE WEST OVERNIGHT...AND
LOSING A BIT OF ITS IDENTITY. 18Z RUC SHOWS THAT NVA REMAINS OVER
ERN CWA THROUGH NIGHT. ALSO OF NOTE...WINDS ACROSS ERN CWA ARE MORE
SWRLY INSTEAD OF SOUTH OR SOUTHEASTERLY...SO REAL HIGH DWPT AIR NOT
BEING PUSHED INTO CURRENT LINE OF TSRA. 8H JET GETS GOING TONIGHT
THAT WILL HELP WITH FORCING...AND LACK OF CAP WILL ENSURE THAT
ANYTHING THAT GETS GOING SHOULD STAY. WITH HIGH DWPTS ACRSS
EAST...LOWS SHOULD STAY UP TONIGHT.

FOR SUNDAY...PROBLEM DEALS WITH TROUGH SLIDING THROUGH. EVEN THO THE
ETA APPEARED TO INIT THE LEAD VORT SLIDING THROUGH TONIGHT...IT
HANDLED POORLY THE STRONGER VORT EJECTING OUT OF 4 CORNERS
NOW...WITH THE AVN DOING MUCH BETTER. 7H AND 5H TROFS PUSH INTO CWA
DURING DAY...BUT OMEGA FIELDS NOT ALL THAT IMPRESSIVE. 7H TEMPS WARM
WITH PASSAGE OF VORT TONIGHT. AVN KEEPS BOUNDARY TO OUR WEST...WHILE
THE ETA PUSHES FEATURE THROUGH DURING DAY. AM MORE INCLINED TO
FOLLOW AVN SOLN WITH ITS BETTER INIT OF VORT MAX. SFC LOW FORMS ON
SRN END OF TROUGH LATE IN THE DAY AND BEGINS TO EJECT TO THE EAST.
TSRA MAY FIRE LATER IN THE EVENING AS TROFS APPROACH.

FOR MONDAY...RIDGE BEGINS TO BUILD BACK INTO REGION WITH LAYERS
WARMING NICELY. PLENTY OF MID AND HIGH LEVEL CLOUDS AROUND TO ENSURE
PCLOUDY/PSUNNY CONDS.

FOR EXTENDED...DECENT WARMUP IN STORE THROUGH FIRST PART OF
FORECAST...AS RIDGE REBOUNDS NICELY AND LAYERS WARM. NO WELL DEFINED
WAVE SLIDING THROUGH AND WARM FRONT REMAINS WELL TO OUR NORTH. RIDGE
BEGINS TO FLATTEN ON THURSDAY AS STRONG 5H WRN LOW BEGINS TO EJECT
OVER RIDGE. SFC LOW FORMS ACROSS THE WEST WITH COLD FRONT TRAILING
SOUTH AND WEST. AS LOW MOVES TO THE EAST...INVERTED TROF TAKES SHAPE
ACROSS CWA LATER ON THURSDAY AND CONTS INTO FRIDAY. TROF PUSHES EAST
OF CWA ON SATURDAY...BUT STILL APPEARS THAT OVERRUNNING STRATIFORM
TYPE PCPN WILL LINGER INTO SATURDAY.

.ABR...SVR TSTORM WATCH FOR KMBG AND KPIR TIL 02Z.
       SVR TSTORM WATCH FOR KABR AND KATY TIL 03Z.

HINTZ