Rapid City, SD...North Platte, NE...Dickinson, ND...Scottsbluff, NE...Lexington, NE...
Forecast Discussion
SPC AC 241711
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1211 PM CDT FRI MAY 24 2013
VALID 251200Z - 261200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NORTHERN AND CENTRAL
HIGH PLAINS...
...NRN/CNTRL HIGH PLAINS...
EARLY MORNING SHORT-WAVE TROUGH IS EXPECTED TO ROTATE NWD ACROSS SRN
AB/SK AND WEAK HEIGHT RISES ARE ANTICIPATED ACROSS THE NRN ROCKIES
IN ITS WAKE. EVEN SO A BROAD ZONE OF MID LEVEL SWLY FLOW ON THE
ORDER OF 30-40KT SHOULD EXTEND ACROSS THE GREAT BASIN INTO THE
NRN/CNTRL HIGH PLAINS THROUGH THE PERIOD. THIS BROAD ZONE OF MODEST
DEEP LAYER SHEAR IS EXPECTED TO SUPPORT SEVERAL CLUSTERS OF
ORGANIZED TSTM ACTIVITY...INITIALLY FORMING WITHIN UPSLOPE REGIONS
ALONG LEE TROUGH...THEN POSSIBLY MODULATED BY LLJ AFTER DARK.
BOUNDARY LAYER MOISTURE IS EXPECTED TO ADVANCE NWD ACROSS THE HIGH
PLAINS AS LEE TROUGH BECOMES FIRMLY ESTABLISHED DOWNSTREAM OF WRN
U.S. UPPER TROUGH. SFC DEW POINTS IN THE 50S SHOULD ADVECT ACROSS
THE WRN DAKOTAS INTO ERN MT WHERE 2KM DEEP ELY LOW LEVEL WINDS WILL
VEER INTO THE SW AT MID LEVELS. FORECAST SOUNDING FOR MLS AT 23/00Z
DEPICTS MODEST INSTABILITY...SBCAPE OF 2800 J/KG...AND STRONG SHEAR
SUPPORTIVE OF SUPERCELLS. OTHER SOUNDINGS ACROSS THE HIGH PLAINS
EXHIBIT THESE CHARACTERISTICS FAVORABLE FOR SUSTAINED ROTATING
UPDRAFTS. ALTHOUGH NO DISCERNIBLE DISTURBANCES ARE FORECAST TO
AFFECT THE HIGH PLAINS DURING THE AFTERNOON IT APPEARS STRONG
DIURNAL HEATING WILL WEAKEN THE CAP SUCH THAT OROGRAPHIC FORCING
SHOULD LEAD TO TSTM DEVELOPMENT BY LATE AFTERNOON. LARGE HAIL IS
LIKELY WITH ANY SUPERCELL THAT EVOLVES ACROSS THIS REGION AND
ISOLATED TORNADOES ARE ALSO POSSIBLE.
...ERN NM/WEST TX...
MUCH WEAKER DEEP LAYER FLOW IS FORECAST ACROSS THE SRN ROCKIES WHERE
500 MB FLOW MAY STRUGGLE TO MAINTAIN 20KT INTO ERN NM. AS ACROSS
THE NRN/CNTRL HIGH PLAINS...STRONG HEATING NEAR THE LEE TROUGH WILL
PROVE INSTRUMENTAL IN AFTERNOON THUNDERSTORM DEVELOPMENT. A FEW
STORMS MAY PRODUCE HAIL/WIND ACROSS THIS REGION BUT WITH WEAKER
SHEAR THE LIKELIHOOD FOR MEANINGFUL ORGANIZATION IS CONSIDERABLY
LESS THAN POINTS NORTH.
..DARROW.. 05/24/2013
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z