Apr 22, 2014 2000 UTC Day 1 Convective Outlook
Updated: Tue Apr 22 20:01:38 UTC 2014 (20140422 2000Z Day 1 shapefile | 20140422 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140422 2000 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20140422 2000 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20140422 2000 UTC Day 1 Damaging Wind Probabilities Graphic
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.
Probabilistic Large Hail Graphic
20140422 2000 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 47,562 748,035 Pocatello, ID...Bozeman, MT...Rexburg, ID...Jackson, WY...Smithfield, UT...
   SPC AC 221958

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0258 PM CDT TUE APR 22 2014

   VALID 222000Z - 231200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NORTHERN
   GREAT BASIN/NORTHERN ROCKIES...

   ...SUMMARY...
   THUNDERSTORMS MAY PRODUCE DAMAGING WIND OVER PARTS OF SOUTHEAST
   IDAHO...SOUTHWEST MONTANA...AND WESTERN WYOMING...INCLUDING
   YELLOWSTONE NATIONAL PARK.  ISOLATED STRONG TO SEVERE THUNDERSTORMS
   ALSO MAY OCCUR OVER THE CENTRAL-NORTHERN HIGH PLAINS.

   ...20Z UPDATE...
   ONLY LIMITED CHANGES TO PRIOR OUTLOOK...CONSULT PRIOR DISCUSSION
   BELOW. OBSERVATIONAL/GUIDANCE TRENDS STILL INDICATE THAT TSTMS WILL
   INCREASE IN NUMBER/INTENSITY THIS AFTERNOON WITHIN A CORRIDOR
   INCLUDING EASTERN ID/NORTHERN UT INTO SOUTHERN MT/WESTERN WY...WITH
   THE STRONGEST STORMS CAPABLE OF LOCALIZED WIND DAMAGE/SOME SEVERE
   HAIL. FOR MORE SHORT-TERM DETAILS...SEE MESOSCALE DISCUSSION 380.

   ..GUYER.. 04/22/2014

   .PREV DISCUSSION... /ISSUED 1128 AM CDT TUE APR 22 2014/

   ...SYNOPSIS...
   FAIRLY AMPLIFIED BUT PROGRESSIVE PATTERN WILL CONTINUE ACROSS THE
   CONUS THROUGH WED. SHARP W CST TROUGH WILL ASSUME A SLIGHT NEGATIVE
   TILT LATER TODAY/TNGT AS LEAD SHORTWAVE IMPULSE NOW CROSSING THE
   SIERRA TURNS E ACROSS NV THIS AFTN...AND CONTINUES NNE ACROSS SRN
   UT/WRN WY EARLY WED. FARTHER E...DOWNSTREAM RIDGE WILL PROGRESS E
   ACROSS THE PLNS TODAY AS GRT LKS SHORTWAVE TROUGH AMPLIFIES SE
   TOWARD THE MID-ATLANTIC. 

   AT LWR LVLS...BROAD SFC CYCLONE NOW ENCOMPASSING MUCH OF THE
   INTERIOR NORTHWEST SHOULD STRENGTHEN AND CONSOLIDATE IN THE LEE OF
   THE NRN RCKYS THIS AFTN/EVE...WITH FURTHER STRENGTHENING EXPECTED AS
   THE LOW REDEVELOPS E/SE INTO WRN SD BY 12Z WED. ELSEWHERE...COLD
   FRONT NOW EXTENDING FROM THE LWR GRT LKS TO THE TX GULF CST SHOULD
   CONTINUE STEADILY SEWD THROUGH THE PERIOD...WITH SOME
   INTENSIFICATION EXPECTED FROM THE CNTRL APPALACHIANS NWD AS BOUNDARY
   COMES UNDER THE INFLUENCE OF AMPLIFYING UPR TROUGH.  

   ...NRN RCKYS THIS AFTN INTO TNGT...
   APPROACH OF LEAD UPR IMPULSE ASSOCIATED WITH WRN STATES TROUGH WILL
   ENHANCE LARGE-SCALE ASCENT AND DEEP SHEAR ALONG ASSOCIATED COLD
   FRONT CROSSING THE NRN GRT BASIN LATER TODAY. COUPLED WITH SFC
   HEATING AND MODEST LOW-LVL MOISTENING IN WAKE OF PREVIOUS UPR
   DISTURBANCE...SETUP MAY SUPPORT THE DEVELOPMENT OF A NARROW BAND OF
   LOW-TOPPED CONVECTION/STORMS ALONG THE FRONT FROM NRN UT NNE TO WRN
   MT. SUCH ACTIVITY SHOULD FORM DURING THE MID-AFTN AND CONTINUE
   THROUGH LATE TNGT/EARLY WED...WITH THE STRONGEST UPDRAFTS EXPECTED
   LATE THIS AFTN THROUGH EARLY TNGT. GIVEN STRONG TO VERY
   STRONG...UNIDIRECTIONAL SSWLY LOW-MID TROPOSPHERIC FLOW AND
   STEEPENING LOW TO MID-LVL LAPSE RATES...POTENTIAL WILL EXIST FOR
   SVR/DMGG WIND GUSTS AND PERHAPS AN INSTANCE OR TWO OF MARGINALLY SVR
   HAIL.
     
   ...CNTRL/NRN HIGH PLNS THIS AFTN/EVE...
   ISOLD TO WDLY SCTD LATE DAY/EARLY EVE STORMS EXPECTED TO FORM OVER
   THE HIGHER TERRAIN OF ERN WY AND CO SHOULD MOVE/DEVELOP E/NE INTO
   THE ADJACENT HIGH PLNS. WHILE SPARSE MOISTURE WILL LIMIT
   BUOYANCY...STRONG STATIC INSTABILITY /STEEP LOW TO MID-LVL LAPSE
   RATES/ AMIDST STRENGTHENING MEAN SW FLOW AHEAD OF WRN U.S. TROUGH
   MAY YIELD A FEW STORMS WITH LOCALLY DMGG WIND.  

   ...ERN U.S....
   LOW TO MID-LVL LAPSE RATES AND/OR DEEP SHEAR APPEAR TOO LIMITED TO
   WARRANT INCLUSION OF SVR PROBABILITIES FOR STORMS EXPECTED TO FORM
   ALONG COLD FRONT CROSSING GA/SC LATER TODAY...OR WITH ACTIVITY
   FORMING ALONG THE SAME FRONT AHEAD OF DEEPENING UPR TROUGH IN THE
   NORTHEAST.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z