Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Rapid City, SD...Bismarck, ND...Grand Island, NE...Minot, ND...Kearney, NE...
SPC AC 041630
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT FRI JUL 04 2014
VALID 041630Z - 051200Z
...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY
TONIGHT FOR ERN ND AND NW MN...
...SUMMARY...
ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
EVENING ACROSS PARTS OF EASTERN NORTH DAKOTA INTO NORTHWEST
MINNESOTA. STRONG WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. A
FEW STRONG STORMS WITH HAIL AND GUSTY WINDS WILL ALSO BE POSSIBLE
THIS AFTERNOON AND EVENING ACROSS THE CENTRAL PLAINS...AND ACROSS
WEST CENTRAL AND SOUTHWEST ARIZONA.
...NRN PLAINS LATE THIS AFTERNOON INTO EARLY TONIGHT...
NOT MUCH CHANGE TO THE PREVIOUS OUTLOOK. LOW-LEVEL
MOISTENING/DESTABILIZATION WILL CONTINUE TODAY ACROSS THE ERN
DAKOTAS/WRN MN...WHERE BOUNDARY LAYER DEWPOINTS COULD INCREASE TO
THE MID 60S BY LATE AFTERNOON. BASED ON REGIONAL 12Z
SOUNDINGS...SUCH MOISTENING /IN TANDEM WITH DAYTIME HEATING/ WILL
RESULT IN AFTERNOON MLCAPE VALUES NEAR 2500 J/KG. LINGERING CLOUD
COVER WITH ELEVATED MORNING CONVECTION AND CONVECTIVE TEMPERATURES
NEAR 90 F SUGGEST THAT SOME CONVECTIVE INHIBITION MAY REMAIN THIS
AFTERNOON...WHICH CASTS DOUBT ON CONVECTIVE INITIATION GIVEN THE
LACK OF A CLEAR LOW-LEVEL FOCUS FOR STORM FORMATION. THE MOST
PROBABLE SCENARIO WILL BE FOR ISOLATED STORMS TO FORM LATE
AFTERNOON/EVENING ACROSS ERN ND/NW MN AFTER PEAK HEATING...IN
CONJUNCTION WITH WEAK ASCENT ACCOMPANYING THE PASSAGE OF A SUBTLE
MIDLEVEL TROUGH MOVING THROUGH THE LARGER-SCALE RIDGE. ASSUMING
STORMS FORM AND BECOME ROOTED IN THE BOUNDARY LAYER...THE DEGREE OF
BUOYANCY/LAPSE RATES AND EFFECTIVE BULK SHEAR OF 30-40 KT WILL
SUPPORT A RISK OF LARGE HAIL/DAMAGING WINDS WITH SUPERCELLS.
...CENTRAL PLAINS THIS AFTERNOON INTO TONIGHT...
LEE CYCLOGENESIS WILL PROMOTE CONTINUED MOISTURE RETURN NWD FROM THE
SRN PLAINS TO THE CENTRAL PLAINS. STRONG SURFACE HEATING AND STEEP
MIDLEVEL LAPSE RATES WILL CONTRIBUTE TO MODERATE-STRONG INSTABILITY
THIS AFTERNOON...WHEN STORM DEVELOPMENT IS EXPECTED ALONG THE LEE
TROUGH ACROSS THE CENTRAL HIGH PLAINS. DEEP-LAYER VERTICAL SHEAR
WILL BE MARGINAL FOR ORGANIZED SEVERE STORMS...BUT THE DEGREE OF
BUOYANCY WILL FAVOR SOME RISK FOR ISOLATED LARGE HAIL...AS WELL AS
ISOLATED STRONG OUTFLOW WINDS WITH STEEP LOW-LEVEL LAPSE RATES.
SOME FORM OF THE EVENING CONVECTION COULD PERSIST OVERNIGHT AS WAA
INCREASES WITH A STRENGTHENING SLY LLJ.
...SRN AND WRN AZ THIS AFTERNOON/EVENING...
CLOUDS ARE WIDESPREAD ACROSS AZ THIS MORNING...AND LAPSE RATES ARE
POOR BASED ON 12Z SOUNDINGS. AN EMBEDDED WEAK MIDLEVEL WAVE IS
DRIFTING NWWD OVER W CENTRAL AZ...WITH MIDLEVEL FLOW BECOMING SELY
ALONG AND S OF THE RIM. THE CLOUDS WILL SLOW SURFACE HEATING AND
MIDLEVEL FLOW WILL NOT BE PARTICULARLY FAVORABLE FOR STORMS TO
PROPAGATE OFF THE RIM TO THE LOWER DESERTS. WILL MAINTAIN LOW WIND
PROBABILITIES...BUT THE THREAT FOR DAMAGING GUSTS APPEARS QUITE
MARGINAL.
..THOMPSON/SMITH.. 07/04/2014
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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