ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 040859
   SPC AC 040859

   Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0359 AM CDT Thu Jun 04 2020

   Valid 071200Z - 121200Z

   ...DISCUSSION...
   ...Sunday/Day 4 and Monday/Day 5...
   On Sunday, the medium-range models are in reasonable good agreement
   with an upper-level trough in the western U.S. and an upper-level
   ridge in the mid to upper Mississippi Valley. South-southwest
   mid-level flow is forecast in the northern Plains in the exit region
   of a mid-level jet. A broad corridor of moderate to strong
   instability should be in place in the northern Plains by afternoon
   with thunderstorms developing to the north of the strongest
   instability, from central South Dakota northward to near the
   Canadian Border. Moderate deep-layer shear should be favorable for a
   severe threat with large hail and wind damage possible. Will
   maintain a 15 percent probability contour for Sunday afternoon and
   evening. Will not upgrade at this time due to uncertainties
   concerning storm coverage.

   On Monday, the models move the upper-level trough into the northern
   Rockies and maintain south-southwest mid-level flow across the
   northern Plains. Moderate instability may develop by Monday
   afternoon from parts of the northern Plains eastward into the upper
   Mississippi Valley. Due a moderately sheared wind profile, an
   isolated severe threat will be possible as thunderstorms form along
   the instability corridor during the late afternoon and evening.
   However, the magnitude and spatial distribution of the severe threat
   is uncertain at this time.

   Also, early on Monday, the National Hurricane Center is forecasting
   Tropical Storm Cristobal to move northward into Louisiana.
   Thunderstorms associated with this system could have a severe
   threat.

   ...Tuesday/Day 6 to Thursday/Day 8...
   The models remain in good agreement for Tuesday with an upper-level
   trough in the central and northern Plains. Southwest mid-level flow
   is forecast across the upper Mississippi Valley where a cold front
   should be present. Instability along and ahead of the front may be
   strong enough for an isolated severe threat Tuesday afternoon. But
   predictability remains too low for a threat area at this time.

   An isolated severe threat could also accompany the remnants of
   Tropical Storm Cristobal in parts of the Ozarks and mid Mississippi
   Valley during the day on Tuesday.

   For Wednesday and Thursday, the cold front is forecast to move from
   the mid Mississippi Valley into the Appalachians, where the front is
   forecast to stall. At mid-levels, there is considerable spread in
   the model solutions. If the models are close concerning the front
   position, a few severe storms would be possible across parts of the
   Appalachians each afternoon. But predictability remains low late in
   the Day 4 to 8 period.

   ..Broyles.. 06/04/2020

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