Mar 8, 2018 1300 UTC Day 1 Convective Outlook
Updated: Thu Mar 8 12:12:34 UTC 2018 (20180308 1300Z Day 1 shapefile | 20180308 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20180308 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Tornado Graphic
20180308 1300 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
20180308 1300 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
No Risk Areas Forecast
Probabilistic Large Hail Graphic
20180308 1300 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
No Risk Areas Forecast
   SPC AC 081212

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0612 AM CST Thu Mar 08 2018

   Valid 081300Z - 091200Z

   ...NO THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   No thunderstorm areas are forecast today.

   ...Synopsis...
   The large-scale upper-air pattern will remain characterized by mean
   eastern troughing and western ridging, dominated by a large cyclone
   now located over the Great Lakes.  That cyclone will undergo a net
   eastward shift as:
   1.  The main 500-mb low and associated vorticity max -- initially
   over eastern lower MI -- pivot east-southeastward to the CT/RI area
   by 12Z, and
   2.  The leading, smaller cyclone -- now centered just east of Cape
   Cod -- is forecast to pivot northward in the cyclonic-flow field of
   the approaching Great Lakes low today.  This perturbation will
   deamplify to an open wave and retrograde into the northern
   semicircle of the larger cyclone impinging on New England. 

   Related cyclonic flow will cover a large swath of eastern North
   America and southward across the Gulf and Cuba, to the Yucatan
   Peninsula and northwestern Caribbean.  The associated surface cold
   front has passed offshore from FL, leaving behind a large
   continental/polar anticyclone that will shift southeastward from the
   Plains states to the Southeast.  Associated dry/stable conditions
   will preclude thunder east of the Rockies, while ridging aloft
   suppresses convective potential over the Southwest.  

   A mid/upper-level shortwave trough -- now evident in moisture-
   channel imagery offshore from the Pacific Northwest -- will weaken
   considerably as it penetrates the mean ridge inland.  Still,
   divergence aloft and weak shots of DCVA will spread over the
   northern Rockies, destabilizing the midlevels.  A rogue lightning
   strike cannot be ruled out with shallow elevated convection
   occupying small pockets of roughly 50-75 J/kg MUCAPE.  Meager
   moisture and the weakening character of the perturbation aloft
   indicate any related thunder potential will be very isolated and
   brief, at best -- too much so to justify a 10% unconditional thunder
   area in this outlook.

   ..Edwards.. 03/08/2018

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z