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.
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 %
26,947
4,330,745
San Antonio, TX...Austin, TX...Killeen, TX...Round Rock, TX...Temple, TX...
SPC AC 021630
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CDT Wed Sep 02 2020
Valid 021630Z - 031200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NORTHERN VA INTO
SOUTHEAST PA...
...SUMMARY...
The most likely corridor for at least a couple tornadoes and locally
damaging winds is from northern Virginia to southeast Pennsylvania,
between 4 to 10 PM EDT.
...Mid-Atlantic and Northeast...
Primary feature of concern for late afternoon to early evening
severe potential is an MCV tracking east from the Upper OH Valley.
This feature in conjunction with low-level convergence along the lee
trough should aid in at least isolated thunderstorms off the Blue
Ridge from central VA to southern PA. Additional storms will likely
develop in the lee of the Lower Great Lakes and spread east. Warm
mid-level temperatures from -4 to -6 C at 500 mb and similarly poor
lapse rates aloft will limit updraft accelerations. Where cloud
breaks are present east of the Blue Ridge, boundary-layer warming
should support MLCAPE in excess of 1000 J/kg from MD southward given
the presence of mid 70s surface dew points. Sufficient low and
deep-layer shear will be present for a few supercells to form. These
will be capable of producing a risk for at least a couple tornadoes
across parts of the Mid-Atlantic region, along with locally damaging
winds. A cat 2/SLGT risk has been introduced for this possibility.
...Mid-South...
A convectively augmented shortwave trough will drift east across
northern TX through the period, with a series of downstream MCVs
gradually progressing east-northeast towards the OH Valley. A belt
of enhanced 700-mb southwesterlies should be centered on the
ArkLaTex to TN Valley at peak heating. This should aid in
relatively greater potential for downbursts to occur as convection
likely redevelops ahead of MCVs in central AR and the ArkLaTex. Poor
mid-level lapse rates and flow weakening with height above 700 mb
suggest a cat 1/MRGL risk remains warranted.
...South-central TX...
A conditional large hail/severe wind/brief tornado risk remains
during the late afternoon to early evening, focused with potential
peak heating convective development in association with an MCV near
Del Rio that should drift east. Some uncertainty exists with the
degree of midday non-severe convection ongoing as outflow has
already reached Austin. Still, with ample boundary-layer heating
occurring to the west of this outflow, large buoyancy should develop
within a rather confined corridor in parts of the Brush Country.
Deep-layer shear may be adequate for a couple transient
supercells/small clusters.
...ND...
A pronounced shortwave trough will dig as it progresses from the
Canadian Prairies into northern MN by tonight. A sharp cold front
will sweep southeast across ND during the late afternoon to
mid-evening. Higher-based showers that may deepen into a few
thunderstorms are expected along the front amid scant buoyancy.
Inverted-v thermodynamic profiles should support mixing of
strengthening mid-level flow such that isolated severe wind gusts
are possible.
..Grams/Dial.. 09/02/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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