May 5, 2016 0600 UTC Day 1 Convective Outlook
Updated: Thu May 5 05:13:16 UTC 2016 (20160505 1200Z Day 1 shapefile | 20160505 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160505 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 53,912 912,487 Nampa, ID...Missoula, MT...Meridian, ID...Caldwell, ID...Lewiston, ID...
Probabilistic Tornado Graphic
20160505 1200 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.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20160505 1200 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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 54,678 948,994 Nampa, ID...Missoula, MT...Meridian, ID...Caldwell, ID...Lewiston, ID...
Probabilistic Large Hail Graphic
20160505 1200 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.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 54,460 912,789 Nampa, ID...Missoula, MT...Meridian, ID...Caldwell, ID...Lewiston, ID...
   SPC AC 050513

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1213 AM CDT THU MAY 05 2016

   VALID 051200Z - 061200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS FOR PORTIONS OF ID/ORE/WA/MT...

   ...SUMMARY...
   A FEW STRONG TO LOCALLY SEVERE THUNDERSTORMS ARE FORECAST THIS
   AFTERNOON AND EARLY EVENING ACROSS THE INTERIOR PACIFIC NORTHWEST
   AND THE NORTHERN ROCKIES.

   ...SYNOPSIS...
   A HIGHLY AMPLIFIED BLOCKING PATTERN TODAY WILL FEATURE A STOUT
   MID-LEVEL RIDGE OVER THE SRN ROCKIES NWD INTO THE NRN PLAINS WHILE A
   PAIR OF CLOSED LOWS/TROUGHS --LOCATED ALONG THE W COAST AND SRN
   APPALACHIANS-- MOVE SLOWLY EWD DURING THE PERIOD.  THE NRN FRINGE OF
   A CORRIDOR OF STRONG MID-LEVEL FLOW OVER THE INTERIOR W WILL
   ENCOMPASS ADJACENT PORTIONS OF ID/ORE/MT.  IN THE LOW LEVELS...A
   BROAD AREA OF LOW PRESSURE WILL MOVE LITTLE DURING THE DAY OVER THE
   INTERIOR WRN U.S. WHILE HIGH PRESSURE IS CENTERED OVER MO.

   ...ORE/ID/WA/MT...
   BETWEEN THE MID-LEVEL RIDGE OVER THE HIGH PLAINS AND TROUGH LOCATED
   TO THE W...DEEP SLY TROPOSPHERIC FLOW WILL PREVAIL FROM THE GREAT
   BASIN NWD INTO THE PACIFIC NW.  A FRONTAL ZONE WILL SLOW/STALL AND
   BECOME QUASISTATIONARY NEAR THE ORE/ID BORDER NWD INTO THE NRN
   ROCKIES.  DESPITE THE LACK OF AN APPARENT SHORTWAVE IMPULSE MOVING
   THROUGH THE REGION DURING THE DAY...STRONG HEATING AND A MODEST
   INCREASE IN TROPOSPHERIC MOISTURE LEADING TO WEAK BUOYANCY...COUPLED
   WITH UPPER DIFFLUENCE WILL YIELD AT LEAST ISOLATED THUNDERSTORM
   DEVELOPMENT BY LATE AFTERNOON.  STEEP H7-H5 LAPSE RATES /AROUND 8
   DEG C PER KM/ AND ADEQUATE CLOUD-LAYER SHEAR FOR STORM ORGANIZATION
   WILL PROBABLY RESULT IN A FEW STRONGER STORMS CAPABLE OF A
   LARGE-HAIL AND STRONG TO LOCALLY SEVERE WIND-GUST RISK. THE LOSS OF
   HEATING BY EARLY TO MID-EVENING WILL SERVE TO WEAKEN STORMS.

   ...ELSEWHERE...
   ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP
   DURING THE DAY NEAR THE ERN U.S. H5 COLD POCKET OVER THE CAROLINAS
   /-20 TO -25 DEG C/ DESPITE MODEST BOUNDARY-LAYER MOISTURE.  WHERE
   HEATING IS MAXIMIZED...A FEW HUNDRED J/KG MUCAPE COUPLED WITH ASCENT
   WILL PROBABLY YIELD A FEW CLUSTERS OF WEAK THUNDERSTORMS DURING THE
   AFTERNOON.  THIS ACTIVITY WILL QUICKLY DIMINISH BY EARLY EVENING.

   ..SMITH/COOK.. 05/05/2016

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z