Day 4-8 Severe Weather Outlook Issued on Jul 29, 2020
Updated: Wed Jul 29 08:31:02 UTC 2020
Day 4 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 5 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 6 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 7 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 8 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4
Sat, Aug 01, 2020 - Sun, Aug 02, 2020
D7
Tue, Aug 04, 2020 - Wed, Aug 05, 2020
D5
Sun, Aug 02, 2020 - Mon, Aug 03, 2020
D8
Wed, Aug 05, 2020 - Thu, Aug 06, 2020
D6
Mon, Aug 03, 2020 - Tue, Aug 04, 2020
(All days are valid from 12 UTC - 12 UTC the following day)
Note: A severe weather area depicted in the Day 4-8 period indicates 15%, 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears unlikely (i.e., less than 15%) for the forecast day.
Forecast Discussion
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 290829
SPC AC 290829
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0329 AM CDT Wed Jul 29 2020
Valid 011200Z - 061200Z
...DISCUSSION...
To the east of initially amplified mid-level ridging over western
North America, there may be some consolidation of troughing within
initially split branches of westerlies by late this coming weekend,
roughly along a positively tilted axis across eastern Canada and the
Great Lakes into the lower Mississippi Valley. Within southwesterly
flow downstream of this axis, models continue to suggest that a
convectively generated or enhanced perturbation emerging from the
southern branch may accelerate northeast of the Mid South region
into the northern Mid Atlantic Coast states Saturday into Sunday. A
belt of enhanced flow (30-40 kt in the 850-500 mb layer) to the
south of this feature, and an associated surface low, could
contribute to at least some organized severe weather potential.
Mid-levels may be fairly warm, but surface dew points in the warm
sector probably will be high (near or above 70f), possibly
contributing to an environment conducive to convection capable of
producing potentially damaging wind gusts, and perhaps a couple of
tornadoes.
While the predictability of the associated synoptic and sub-synoptic
features remains low at this extended range, resulting in the
maintenance of less than 15 percent severe probabilities, this could
still change in later outlooks for this time period. Similar
uncertainties exist concerning tornado potential with a possible
developing tropical cyclone, which might impact Florida this
weekend.
Thereafter, mid/upper flow across the U.S. may transition to a less
amplified regime, during the early to middle portion of next week.
However, there is little evidence in model output at this time to
suggest anything beyond relatively isolated and/or minor severe
weather potential.
..Kerr.. 07/29/2020
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