Hail in Iowa, May 8, 2023

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
223 PM CDT Mon May 8 2023

.SHORT TERM...(This Evening through Tuesday)
Issued at 220 PM CDT Mon May 8 2023

TONIGHT: As of mid afternoon, an area of unstable cumulus and weak
showers has developed in southeast SD and is tracking northeast,
associated with a weak upper disturbance pivoting around the upper
low to our north. Main focus through early this evening will be
whether isolated storms are able to develop as this feature tracks
near and east of the I-29 corridor. CAMs suggest a low end potential
for a few isolated strong to severe Tstorms with up to quarter sized
hail developing through 9pm east of I-29, but this is conditional on
whether there is enough instability (up to 1000 J/kg) for storms to
tap into. Dew points observed in the upper 50s near the Hwy 20
corridor in IA suggest this remains possible.

After this early evening wave exits, quiet zonal flow aloft and
mostly clear skies prevail until after midnight. Expect temperatures
to fall into the 50s with light winds and cirrus spreading in late
tonight.

TUESDAY: Zonal flow aloft persists with another weak mid level wave
sliding by to our west. Model soundings suggest an increasing chance
of morning showers near the Missouri River, but lingering subcloud
layer dry air below 7 kft means it will be tough to get more than a
few hundredths of an inch of rain. As the day progresses, this dry
air becomes less of a concern with 12z deterministic models favoring
moistening via warm air advection and a warm front lifting
widespread 50+ degree dew points in by the afternoon. Thus expect
rain chances to spread northeastward with the wave. Can't rule out a
few rumbles of thunder but rainfall amounts are favored to remain
under a tenth inch at most sites. A stronger LLJ should aid
destabilization to 500-1500 J/kg MUCAPE in the afternoon and
evening, but weaker shear and mid level lapse rates favor only
weaker multicell storms, so severe weather looks unlikely.

Highs will be able to reach the 70s pretty easily south of the I-90
corridor where south winds will prevail, but confidence is lower
regarding highs further north ahead of the front. Near and north of
I-90 in easterly flow, showers and cloud cover could hold
temperatures back in the 60s.

.LONG TERM...(Tuesday Night through Monday)
Issued at 220 PM CDT Mon May 8 2023

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: Ridging aloft and residual
dry air in the region favor drier weather, which is in agreement
with global ensembles. Convective remnants from better forcing for
ascent over the High Plains are our best hope for any meaningful
rain and impactful weather. The latest 12z models (including
global ensembles) favor drier weather than not with ridging owing
to a period of slight warming. Widespread highs in the 70s are
likely Wednesday and Thursday, though could be tapered back some
if clouds or rain stray in for too long. Breezy southeast winds
return as well with gusts in the 20s.

THURSDAY THROUGH THE WEEKEND: Amplified troughing out west shifts
into the eastern Rockies by Thursday and into the High Plains by
Friday. Ensemble guidance favors some periods of an increased
chance (up to 50% chance) of receiving over 0.10 inches of rain
late week as the associated sfc low ejects into the High Plains,
but there are some concerns with the better forcing being
counteracted by strong capping aloft. Near to above normal
temperatures are expected to continue with daily highs mainly in
the 70s until this strong wave gets swept up in northwest flow
aloft late in the weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1240 PM CDT Mon May 8 2023

VFR conditions are expected for the TAF period. A weak CU field
is developing this afternoon as shown on current satellite. Hi-res
guidance has been hinting at the possibility of isolated showers
and storms developing east of I-29 this afternoon. There is a bit
of a higher consensus amongst the guidance with KSUX seeing rain
and have thus included VCSH in KSUX's TAF. While thunder is
possible with the showers, confidence is not high enough to
include in a TAF at this time.

Predominately light and variable westerly flow will begin the TAF
period before slowly turning to out of the southeast to end the TAF
period with speeds of 5-10 knots expected. The next chance for rain
looks to move into the area by the end of the TAF period tomorrow.
As such, have included VCSH in all TAF to end the TAF period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

SHORT TERM...BP
LONG TERM...BP
AVIATION...Meyers

Hazardous Weather Outlook...UPDATED
National Weather Service Sioux Falls SD
225 PM CDT Mon May 8 2023

SDZ038-039-050-052>054-057>060-063>065-068-069-091030-
Beadle-Kingsbury-Gregory-Jerauld-Sanborn-Miner-Brule-Aurora-Davison-
Hanson-Charles Mix-Douglas-Hutchinson-Bon Homme-Yankton-
225 PM CDT Mon May 8 2023

This Hazardous Weather Outlook is for central South Dakota, east
central South Dakota, south central South Dakota and southeast
South Dakota.

.DAY ONE...This afternoon and tonight.

Isolated to scattered showers and thunderstorms will be possible
through early this evening. Severe weather is not expected with this
activity.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Isolated to scattered showers and thunderstorms will be possible
through late this week. At this time, the severe weather threat is
expected to remain low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ040-055-056-061-062-066-067-070-071-091030-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Brookings-Lake-Moody-McCook-Minnehaha-
Turner-Union-
225 PM CDT Mon May 8 2023

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota, northeast Nebraska, east central South
Dakota and southeast South Dakota.

.DAY ONE...This afternoon and tonight.

Isolated to scattered showers and thunderstorms will be possible
early this afternoon into the evening hours. A few isolated strong to severe
thunderstorms with hail up to quarter size cannot be ruled out with
this activity.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Isolated to scattered showers and thunderstorms will be possible
through late this week. At this time the severe weather threat is
expected to remain low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
625 PM CDT MON MAY 8 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0616 PM     HAIL             1 SE ELK POINT          42.67N 96.67W
05/08/2023  M1.00 INCH       UNION              SD   TRAINED SPOTTER

&&

JC