Severe Thunderstorm Warning 91, NWS Des Moines, IA

980 
WWUS53 KDMX 022020
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
320 PM CDT Fri Jun 2 2023

IAC049-153-022030-
/O.CON.KDMX.SV.W.0091.000000T0000Z-230602T2030Z/
Polk IA-Dallas IA-
320 PM CDT Fri Jun 2 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM CDT
FOR SOUTHWESTERN POLK AND EAST CENTRAL DALLAS COUNTIES...

At 320 PM CDT, a severe thunderstorm was located over Windsor
Heights, or near Des Moines, moving northwest at 20 mph.

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...Expect damage to roofs, siding, and trees.

This severe storm will be near...
  Ankeny, Clive, Valley West Mall and Jordan Creek Town Center 
  around 325 PM CDT.

Other locations in the path of this severe thunderstorm include
Johnston, Merle Hay Mall, Saylorville, Urbandale, Waukee, Grimes and
Saylorville Lake.

This includes the following highways...
 Interstate 35 between mile markers 69 and 72.
 Interstate 80 between mile markers 121 and 135.
 Interstate 235 between mile markers 1 and 9.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4164 9389 4173 9365 4153 9358 4151 9363
      4151 9375
TIME...MOT...LOC 2020Z 148DEG 16KT 4160 9369 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cogil

265 
WWUS53 KDMX 022030
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
330 PM CDT Fri Jun 2 2023

IAC049-153-022038-
/O.EXP.KDMX.SV.W.0091.000000T0000Z-230602T2030Z/
Polk IA-Dallas IA-
330 PM CDT Fri Jun 2 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN POLK AND EAST
CENTRAL DALLAS COUNTIES WILL EXPIRE AT 330 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small 
hail to penny size and gusty winds to 40 mph are still possible with 
this thunderstorm.

LAT...LON 4164 9389 4173 9365 4153 9358 4151 9363
      4151 9375
TIME...MOT...LOC 2028Z 142DEG 16KT 4162 9372 

$$

Cogil

Area Forecast Discussion
National Weather Service Des Moines IA
207 PM CDT Fri Jun 2 2023

.DISCUSSION.../Tonight through Friday/
Issued at 207 PM CDT Fri Jun 2 2023

Key Messages:

- Scattered storms this afternoon and evening with a low severe
  weather and locally heavy rain threat, similar to the past
  couple of days.
- Lingering POPs at times this weekend, but with lower coverage,
  then another round of showers and isolated storms around Monday
  night or Tuesday.
- Dry and much more comfortable from late Tuesday through
  Thursday.

A large 500 mb high pressure area remains entrenched over the
Great Lakes and Upper Midwest, with the associated light east to
southeast surface flow promoting warm and humid conditions.
Scattered thunderstorms continue to develop mainly around diurnal
heating maximum, as depicted in current radar imagery with a
marked increase in echoes over the last hour or so, similar to
what has occurred the past couple of days. Once again ambient
shear is effectively non-existent, large-scale forcing nebulous at
best, and mid-level lapse rates poor, combining to promote a very
low severe weather risk. Efficient rainfall rates and relatively
slow storm motions support a continued, limited threat of heavy
rainfall, with any impacts likely confined to low-probability
scenarios such as a heavy core tracking slowly over an urban area.
In other words, this is as close to proverbial garden variety
thunderstorms as we can get in June.

A deep 500 mb trough currently extending down the Atlantic
Canadian coastline will strengthen and dig further south tonight,
eventually closing off as a low over upper New England by late
Saturday. This will cause the aforementioned Great Lakes high to
retrograde westward a bit, pushing somewhat drier air from the
center of the high more into our area and concurrently pushing
most of the showers and storms associated with higher
dewpoints/instability west of our area this weekend. While POPs
will remain in the forecast at times, again mainly around
afternoon/evening each day, coverage should be lower and it will
be somewhat more comfortable as dewpoints fall from current
levels in the mid to upper 60s more into the upper 50s for the
weekend.

Early next week, around Monday-Tuesday, another strong 500 mb
trough will dig down over eastern Canada and interact with the
preceding New England low, resulting in a large gyre that will
park and expand over the northeastern U.S. for most of the week.
This will place Iowa beneath more organized northerly steering
flow, especially from around Tuesday through Thursday, promoting
dry and slightly cooler weather. As the pattern transitions into
this flow it will push a strong backdoor front from the upper
Great Lakes down across Wisconsin and through Iowa around Monday
night or Tuesday. The passage of this front will likely be
accompanied by some showers and a few thunderstorms, but has
slowed down considerably with newer model runs this morning, and
have slowed down progression of POPs accordingly. There is some
support for a renewed threat of locally heavy rainfall during this
time and WPC is advertising a marginal risk of excessive rainfall,
but any impacts are once again expected to be isolated. The
passage of the front will also usher in a few days of glorious
weather with Tuesday- Thursday daily highs generally in the upper
70s to lower 80s, and daytime dewpoints falling into the 40s and
perhaps even upper 30s by Wednesday and Thursday. Eventually the
party will come to an end as the New England gyre finally begins
to ease eastward toward the end of next week, but how a new
pattern evolves after that is still uncertain at this range.

&&

.AVIATION.../For the 18Z TAFS through 18Z Saturday afternoon/
Issued at 1222 PM CDT Fri Jun 2 2023

VFR conditions will prevail through the TAF period. Isolated to
scattered thunderstorms are forecast at times, especially between
about 20Z and 03Z this afternoon/evening, however probability and
expected duration of any impacts at a given terminal are too
low/uncertain to advertise. Did put in a targeted VCTS group at
FOD where odds of impact are slightly however, however, at all
terminals amendments are a possibility later today as radar and
short-term observational trends dictate.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

DISCUSSION...Lee
AVIATION...Lee

Hazardous Weather Outlook
National Weather Service Des Moines IA
230 PM CDT Fri Jun 2 2023

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-031930-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun-
Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene-
Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper-
Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-
Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
230 PM CDT Fri Jun 2 2023

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

Widely scattered showers and thunderstorms are expected to
continue this afternoon into the evening. Locally heavy rain will
be possible, which may lead to ponding of water in low lying and
poor drainage or urban areas. Otherwise, the threat of severe
weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Chances for isolated to scattered storms continue through Tuesday.
Severe weather is unlikely, but slow moving storms may produce
locally heavy rain and result in localized ponding, especially in
urban areas. Otherwise expect lightning and gusty winds at times
with any storms.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated, but rainfall reports are
always appreciated.