Severe Thunderstorm Warning 7, NWS Aberdeen, SD

AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
400 PM CST TUE MAR 7 2000

ALL MDLS COMING TOGETHER ON THE LOCATION AND STRENGTH OF LOW
PRESSURE MOVING ACROSS THE CENTRAL PLAINS THROUGH WED NIGHT.
ABUNDANT MOISTURE AND INSTABILITY MOVING RAPIDLY NORTH ON THE LLJ
AND INTERACTING WITH BOUNDARY EXTENDING FROM SC TO NE SD WILL
CONTINUE TO SET OFF SHOWERS AND THUNDERSTORMS ACROSS THE CWA THROUGH
TONIGHT. TEMPERATURES TONIGHT WILL ONLY FALL OFF A FEW DEGREES BY
MORNING WITH HIGH DWPTS MOVING IN AND CLOUD COVER. AS THE SFC LOW
DEEPENS...E TO NE WINDS ACROSS THE AREA WILL INCREASE BY MORNING. ON
WED...WIDESPREAD RAIN WILL OCCUR ACROSS THE CWA. MDL QPFS ARE ALL
CLOSE AND PUT OUT MORE THAN AN INCH OF RAIN MANY AREAS. MDLS SHOW
THE WINDS INCREASING EVEN MORE DURING THE DAY...WED. IT SHOULD
BECOME VERY WINDY ACROSS THE ENTIRE CWA BY LATE AFTN. ALONG WITH THE
INCREASE IN WINDS WILL COME THE SOUTHWARD ADVANCING COLD AIR...
CHANGING THE RAIN TO SNOW AROUND NOON ACROSS C AND NC SD AND BY LATE
AFTN/EARLY EVENING NE SD AND WC MN. THE SNOW COULD BE HEAVY ACROSS C
AND NC SD WED AFTN. THEREFORE...WILL CONTINUE WITH THE WINTER STORM
WATCH FOR WED AFTN AND NIGHT. FOR FAR NE SD AND WC MN...EAST OF ABR
...THE RAIN WILL CHANGE OVER TO SNOW IN THE EVENING. THE MDLS SHOW
THE LOW WEAKENING AS IT MOVES EAST NORTHEAST. THEREFORE...FAR NE SD
AND WC MN SHOULD NOT RECEIVE ANY HEAVY SNOW. NEVERTHELESS...IT WILL
BECOME VERY WINDY AND COLD LATE WED AFTN AND NIGHT. THE SNOW WILL
END FROM W TO E THROUGH LATE WED NIGHT WITH THE STRONG WINDS STAYING
UP.

ON THURSDAY...MDLS SHOW HIGH PRESSURE BUILDING INTO THE CWA...WITH A
TIGHT SFC PRES GRADIENT REMAINING AND DRIER AIR MOVING IN.
THEREFORE...THE WINDS WILL CONTINUE STRONG ON THURSDAY WITH
DECREASING CLOUDS. TEMPS WILL BE WELL BELOW NORMAL...ESPECIALLY OVER
THE SNOW COVERED AREA. WENT HIGHER THAN THE FAN AND FWC ON POPS
THROUGH THE ENTIRE FORECAST AND NEAR FAN ON TEMPS.

...EXTENDED DISCUSSION...

MODELS ARE NOT IN REAL GOOD AGREEMENT...MRF AND NOGAPS ARE FAIRLY
CLOSE. ECMWF IS VERY DIFFERENT THAN THOSE TWO. THIS CAUSES QUITE A
BIT OF UNCERTAINTY WITH THIS EXTENDED...BUT WILL GENERALLY FOLLOW A
BLEND OF THE MRF AND NOGAPS. THE CWA WILL REMAIN UNDER THE INFLUENCE
OF HIGH PRESSURE TO THE NORTHEAST ON FRIDAY AS A WEAK UPPER WAVE
MOVES JUST SOUTH OF THE STATE. H85 TEMPS WILL BE ON THE RISE...BUT
CLOUD COVER WILL LIKELY KEEP SFC TEMPS FROM RISING TOO MUCH. A
SURFACE TROUGH DEVELOPS OVER THE WESTERN PLAINS ON SATURDAY ALONG
WITH UPPER RIDGING. EXPECT TEMPS TO BE A BIT WARMER WITH NOT AS MUCH
MOISTURE AROUND AND H85 TEMPS AND THICKNESSES CONTINUING TO RISE.
MRF AND NOGAPS SHOW A SURFACE LOW AND UPPER LOW MOVING INTO THE
PLAINS ON SUNDAY...BUT DIFFER IN POSITION AND STRENGTH. BOTH DO
INDICATE SOME PRECIPITATION DURING THE DAY WITH UPPER LEVEL RIDGING
DEVELOPING AGAIN BY EVENING. TEMPS AND THICKNESSES FALL DURING THE
DAY...WILL INTRODUCE A CHANCE OF SNOW SUNDAY AND LEAVE THE REST OF
THE FORECAST DRY.

.ABR...WINTER STORM WATCH...WED AFTN AND WED NIGHT...C AND NC SD
       INTO NE SD TO ABR/REDFIELD LINE

MOHR/PARKIN