MD 2019 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NORTHEAST UTAH INTO SOUTHWEST WYOMING AND FAR SOUTHEAST IDAHO
Mesoscale Discussion 2019
NWS Storm Prediction Center Norman OK
0126 PM CDT Mon Aug 21 2023
Areas affected…Northeast Utah into southwest Wyoming and far
southeast Idaho
Concerning…Severe potential…Watch unlikely
Valid 211826Z – 212030Z
Probability of Watch Issuance…5 percent
SUMMARY…Isolated thunderstorms are expected to develop through the
remainder of the afternoon, and will pose a risk of sporadic strong
to severe wind. Watch issuance is not expected given the isolated
nature of the threat.
DISCUSSION…Over the past hour, GOES visible imagery has depicted
steady vertical growth of cumulus clouds across eastern UT. Sporadic
lightning flashes have also been observed with the deeper towers,
suggesting that more robust convective initiation is probable within
the next 1-2 hours amid steady diurnal destabilization (MUCAPE
values approaching 1000 J/kg). Despite the broken cloud cover,
dewpoint depressions continue to climb into the low 30s with a few
locations reporting 40 F T/Td spreads. In conjunction with recent
forecast soundings, these dewpoint depressions hint at deepening
boundary-layer mixing with LCLs approaching 2 km. While not overly
deep by inter-mountain West standards, this low-level profile is
conducive for downdraft accelerations via evaporative cooling.
Additionally, VWPs across the region are sampling 50-knot winds near
the 2 km AGL level, which may be mixed down by convective
downdrafts. Consequently, thunderstorms will pose a risk for strong
to severe gusts through the late afternoon/evening hours. The
coverage of this threat will be contingent on the number of robust
cells that can become established, which remains uncertain given
unfocused synoptic ascent; therefore, watch issuance is not
anticipated.
..Moore/Grams.. 08/21/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…RIW…GJT…SLC…PIH…
LAT…LON 38261091 39251140 42091214 43151148 43261005 43000921
42090915 38660975 38301004 38171040 38261091
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