MESOSCALE DISCUSSION 1363
NWS STORM PREDICTION CENTER NORMAN OK
0333 PM CDT MON JUL 02 2012
AREAS AFFECTED...ERN ND...NRN AND CNTRL MN
CONCERNING...SEVERE THUNDERSTORM WATCH 454...
VALID 022033Z - 022200Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 454
CONTINUES.
SUMMARY...THE SEVERE THREAT ACROSS WW 454 IS EXPECTED TO INCREASE
THIS AFTERNOON AS A CLUSTER OF STORMS DEVELOPS IN NRN MN OR POSSIBLY
FURTHER TO THE WEST IN FAR ERN ND. EVENTUALLY...A LINE SEGMENT
SHOULD ORGANIZE AND MOVE ESEWD ACROSS THE WATCH AREA WHERE A THREAT
FOR WIND DAMAGE AND LARGE HAIL SHOULD EXIST LATE THIS AFTERNOON.
DISCUSSION...SO FAR STORM COVERAGE HAS REMAINED SPARSE FROM NE ND
EWD ACROSS NRN MN. A FEW SEVERE STORMS ARE LOCATED SOUTH OF THE LAKE
OF THE WOODS ALONG AN AXIS OF STRONG INSTABILITY WITH MLCAPE VALUES
ESTIMATED IN THE 3500 TO 4500 J/KG RANGE. IN ADDITION...REGIONAL
WSR-88D VWPS ARE SHOWING 40 TO 50 KT OF 0-6 KM SHEAR ACROSS THE
WATCH AREA. IN SPITE OF THE STRONG INSTABILITY AND MODERATE DEEP
LAYER SHEAR...LARGE-SCALE ASCENT LIKELY REMAINS WEAK ACROSS NRN MN
WHICH IS KEEPING STORM COVERAGE ISOLATED. AS A VORTICITY MAX NEAR
BISMARCK ND APPROACHES THE WATCH AREA OVER THE NEXT FEW
HOURS...STORM COVERAGE SHOULD GRADUALLY INCREASE. THE LATEST 17Z
HRRR RUN SUGGESTS THAT THE CELLS CURRENTLY IN NRN MN WILL GRADUALLY
ORGANIZE INTO A LINE ACROSS NCNTRL MN LATE THIS AFTERNOON. IF THIS
OCCURS...THEN THE STORMS WILL ENCOUNTER LOWER 70S F SFC
DEWPOINTS...0-3 KM LAPSE RATES NEAR 8.0 C/KM AND A STRENGTHENING
LOW-LEVEL JET. THIS COMBINATION OF FACTORS WILL SUPPORT A WIND
DAMAGE THREAT. LARGE HAIL WILL ALSO BE POSSIBLE WITH THE MORE
INTENSE CORES MAINLY DUE TO THE STRONG INSTABILITY.
..BROYLES/THOMPSON.. 07/02/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
No comments:
Post a Comment