Severe Thunderstorm Warning 1, NWS Aberdeen, SD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
300 AM CDT SAT MAY 3 2003

.SHORT TERM...
MODELS ARE SIMILAR IN HANDLING CURRENT SITUATION.  WILL BLEND ETA
AND AVN WHERE THERE IS DIFFERENCE.  CURRENT WSR-88D SHOWS WEAK AREAS
OF CONVECTION STARTING IN SOUTHCENTRAL SOUTH DAKOTA AND NORTHERN
NEBRASKA.  THESE CELLS APPEAR TO BE FORMING ON THE NOSE OF THE LOW
LEVEL JET.  MODEL TIME HEIGHT CROSS SECTIONS SUGGEST THAT MOISTURE
IS NOT ABUNDANT SO DO NOT EXPECT THESE TO AMOUNT TO MORE THAN
ISOLATED/SCATTERED SHOWERS OR THUNDERSTORMS EARLY TODAY.  THIS
AFTERNOON MOISTURE CONTINUES TO PUSH INTO THE AREA.  AT KPIR AT THIS
TIME ETA MODEL PROG SOUNDINGS SHOW .60 PRECIPITABLE WATER AND A -2
LIFTED INDEX.  ABERDEEN IS DRIER WITH .42 PW AND +2 LI.  BY THIS
AFTERNOON PIERRE SHOWS .90 PW -6 LI AND CAPE VALUES AROUND
1400J/KG.  ABERDEEN COMES UP TO .87 PW AND -2 LI WITH 500J/KG CAPE.
WILL MENTION THUNDERSTORMS EARLY TODAY AND AGAIN THIS AFTERNOON.
TONIGHT THE LOW LEVEL JET GETS COOKING WITH VALUES NEAR 50 KNOTS
ALONG THE EAST SIDE OF THE STATE.  PIERRE TONIGHT WILL SEE PW VALUES
JUST OVER ONE INCH.  EXPECT THIS TO TURN TO A WIDESPREAD RAIN EVENT
TONIGHT AND TO CONTINUE INTO MONDAY NIGHT AS UPPER LOW STACKS
VERTICALLY WITH SURFACE LOW AND IS VERY SLOW TO LEAVE THIS AREA.
TEMPERATURES BLENDED WELL WITH MOS AND GOING GRIDS.

.EXTENDED...TUESDAY THROUGH FRIDAY
AS LOW PRESSURE SHOVES OFF TO THE EAST...A WEAK AREA OF HIGH
PRESSURE BUILDS INTO THE NRN PLAINS TUESDAY. FOR THE REMAINDER OF
THE EXT...WILL HAVE A TROUGH RESIDE OVER THE WRN CONUS. THIS WILL
KEEP THE NRN PLAINS UNDER A SW FLOW ALOFT...WITH A SERIES OF S/WVS
PUSHING THROUGH THE AREA WED THROUGH FRI. THE FIRST WAVE MOVES
THROUGH WED...WITH THE POSSIBILITY OF PRECIP. MDLS SOUNDING SHOW A
WELL-MOISTENED COLUMN...BUT BEST LIFT LOOKS TO REMAIN OUT WEST. WILL
THUS GO WITH SOME CLOUDS FOR NOW. ON THU...A STRONGER WAVE MOVES
OVER THE REGION...WITH THE SFC LOW CENTERED OVER WRN KS/ERN CO. WILL
GET SOUTHERLY FLOW AHEAD OF THE SYSTEM WITH SOME WAA. MDL SOUNDINGS
SHOWING SOME INSTABILITY FOR THU AFTERNOON INTO THE OVERNIGHT...SO
HAVE ADDED -TRW TO THOSE TIME PERIODS. AS FOR FRI...STILL LOOKS FOR
CHANCE OF SHOWERS FRI NIGHT WITH NEXT WAVE PUSHING INTO THE REGION.
HAVE LEFT TEMPS CLOSE TO PREVIOUS FCST...WITH THE EXCEPTION OF
WARMING THE MAX TEMPS FOR THU AND FRI WITH THE SOUTHERLY FLOW.

.ABR...NONE.
KEEFE/ALBRECHT

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-041030-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
526 AM CDT SAT MAY 3 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF CENTRAL...
NORTH CENTRAL AND NORTHEAST SOUTH DAKOTA...AS WELL AS
BIG STONE AND TRAVERSE COUNTIES IN MINNESOTA.

.DAY ONE...TODAY AND TONIGHT
AN APPROACHING LOW PRESSURE SYSTEM WILL CAUSE THUNDERSTORMS AND RAIN
SHOWERS TODAY AND TONIGHT.  THESE STORMS WILL LIKELY PRODUCE STRONG
WINDS...BRIEF HEAVY RAIN...AND SMALL HAIL.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME...ALTHOUGH THERE IS A
SLIGHT CHANCE THAT ONE OF THESE STORMS COULD BECOME SEVERE.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER TODAY OR TONIGHT.