SPC AC 060600

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0100 AM CDT Tue Jun 06 2023

   Valid 071200Z - 081200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHERN HIGH PLAINS...NORTHWEST...NORTHERN PLAINS/UPPER
   MIDWEST...CAROLINAS VICINITY...AND FLORIDA...

   ...SUMMARY...
   Isolated strong to severe thunderstorms appear possible Wednesday
   across parts of the southern High Plains, Northwest, northern
   Plains/Upper Midwest, Carolinas vicinity, and Florida.

   ...Synopsis...
   Upper ridging will remain centered over the northern/central Plains
   on Wednesday. An upper low is forecast to persist over the Northeast
   and Canadian Maritime provinces, with a mid-level shortwave trough
   expected to move generally southward across the Great Lakes, OH
   Valley, and Mid-Atlantic through the period. This should encourage
   mid/upper-level troughing over much of the eastern CONUS. Across the
   western states, a mid/upper-level low initially over CA should
   develop very slowly eastward across the Sierras and western Great
   Basin. A modestly enhanced upper-level sub-tropical jet should
   extend across northern Mexico into the southern Plains, Gulf of
   Mexico, and parts of FL.

   ...Southern High Plains...
   Scattered thunderstorms are forecast to form over the higher terrain
   of central/eastern NM and west TX Wednesday afternoon. Although weak
   upper ridging will persist across this region, modestly enhanced
   mid/upper-level westerly winds should be present with southward
   extent across the southern High Plains in association with a
   sub-tropical jet. Deep-layer shear should generally range around
   20-35 kt, perhaps slightly weaker towards CO/KS. Loosely organized
   thunderstorm clusters spreading eastward Wednesday afternoon/evening
   may be capable of producing isolated severe gusts as low-level lapse
   rates steepen through the day. Occasional large hail also appears
   possible, especially across parts of west TX where marginal
   supercells may occur with slightly stronger effective bulk shear.

   ...Northern California into Oregon/Idaho and Western Montana...
   Similar to Day 1/Tuesday, thunderstorms should initially develop
   over the higher terrain of northern CA due to orographic influences
   and weak ascent on the northern periphery of an upper low. With
   seasonably cool temperatures aloft and modest deep-layer shear
   forecast, some of these thunderstorms could produce marginally
   severe hail. Additional convective development should occur farther
   east into OR/ID and parts of western MT. While low-level moisture is
   forecast to remain rather limited, sufficient instability to support
   high-based thunderstorms is still forecast. 20-30 kt of effective
   bulk shear should also provide modest updraft organization. Isolated
   severe wind gusts should be the main threat with convective clusters
   as they spread generally west-northwestward with time. Some hail
   could also occur with initial development.

   ...Carolinas and Vicinity...
   Weak to moderate instability should develop Wednesday afternoon
   along and south of a weak surface trough/front from central GA
   across coastal SC/NC. Low-level convergence is forecast to remain
   weak, as low/mid-level flow should be mostly westerly and parallel
   to the boundary. Still, strengthening winds with height, especially
   at mid/upper levels in association with an amplifying upper trough,
   should support around 25-35 kt of deep-layer shear. Any
   thunderstorms that can form along the boundary and spread eastward
   towards the Atlantic Coast could produce isolated damaging winds,
   and perhaps marginally severe hail, before moving offshore. Overall
   convective coverage should remain fairly isolated.

   ...Florida...
   A weak, low-amplitude shortwave trough embedded within an
   upper-level sub-tropical jet may advance eastward across the Gulf of
   Mexico and FL Peninsula on Wednesday. A seasonably moist low-level
   airmass should be present across this area, and daytime heating
   should encourage at least moderate instability along the Atlantic
   Coast by early afternoon. Thunderstorms should preferentially form
   along the Atlantic Coast sea breeze and perhaps the Everglades,
   where low-level convergence should be slightly greater. Low-level
   winds are expected to remain weak, but west-southwesterly flow
   should strengthen with height at mid/upper levels. Around 25-35 kt
   of deep-layer shear should promote some updraft organization.
   Occasional damaging winds and severe hail may occur with the more
   robust cores before they move offshore. But, poor mid-level lapse
   rates should tend to limit updraft intensity to some extent, and
   keep the overall severe threat fairly isolated/marginal.

   ...Northern Plains/Upper Midwest...
   On the eastern side of upper ridging, isolated to scattered
   thunderstorms will probably develop Wednesday afternoon along a
   nearly stationary surface front. This convection should then spread
   southward across eastern Dakotas/NE and western MN/IA through early
   evening. Although flow through mid-levels should remain fairly weak,
   deep-layer shear peaking around 20-25 kt should aid modest updraft
   intensity and organization. Loosely organized multicell clusters may
   produce isolated strong to severe wind gusts, with some potential
   for a remnant MCV to provide a focus for renewed convective
   development Wednesday afternoon. Occasional marginally severe hail
   may occur as well.

   ..Gleason.. 06/06/2023

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z