Severe Thunderstorm Warning 37, NWS Des Moines, IA

910 
WWUS53 KDMX 042208
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
508 PM CDT Thu Jun 4 2020

IAC075-083-042217-
/O.EXP.KDMX.SV.W.0037.000000T0000Z-200604T2215Z/
Hardin IA-Grundy IA-
508 PM CDT Thu Jun 4 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN HARDIN AND
WESTERN GRUNDY COUNTIES WILL EXPIRE AT 515 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.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Des Moines .

LAT...LON 4238 9316 4250 9311 4247 9276 4227 9282
TIME...MOT...LOC 2207Z 282DEG 19KT 4239 9284 

$$

Kotenberg

Area Forecast Discussion
National Weather Service Des Moines IA
252 PM CDT Thu Jun 4 2020

.DISCUSSION.../Tonight through Thursday/
Issued at 251 PM CDT Thu Jun 4 2020

Summary...

The name of the game today/tonight will be scattered non-severe
storms this afternoon/evening, followed by a line or broken line of
storms streaming in from the northwest overnight. After that, warm
to hot and humid remains through the weekend and to start next week
before cooling back towards normal by the middle of the week.
Potential remains too for parts/remnants of Tropical Storm Cristobal
influencing Iowa Tuesday.

Today through Friday Morning...

A couple of concerns exist through this time frame, including
scattered storms continuing across portions of northern Iowa and the
potential for a line of stronger storms overnight moving in form the
Dakotas.

Currently, satellite nicely depicts the cumulus field that began to
blossom around/after 16z this morning. A few scattered storms began
around 17z and continue currently, primarily along Highway 20 where
there is also a weak surface/low level convergence boundary and
concurrent with the approach/passage of a weak shortwave aloft. With
the underwhelming wind profiles, storms have primarily been
relegated to short lives of moderate to heavy rainfall and small
hail potential. An isolated stronger updraft capable of marginally
severe hail will be possible, but should continue to follow the
up/down nature with inability to organize.

Later tonight, storms beginning to fire up in W South Dakota and SW
North Dakota will grow upscale and take a likely SE/ESE turn, riding
along the MUCAPE gradient. Some uncertainty remains in the exact
geographic extent, ranging from a long linear structure to a broken
line of sorts. Model trends today have typically trended toward the
latter, likely due to the relatively dry air situated just NW of the
air in the low-mid levels. That said, with better moisture situated
within central Iowa and forecast to remain, if not slowly increase,
overnight there is concern for growth as it enters the forecast
area. Should that come to fruition, the main concerns will revolve
around strong/damaging winds and hail (especially any storms able to
organize within increasing shear profiles). A non-zero tornado
threat will remain based on shear vector orientation (though a small-
ish margin with 0-3km around 30-40 kts), and will be for QLCS
development as opposed to any supercells (which would be more
elevated in nature). Have tended to lean towards the HRRR suite
throughout the day given its relatively well handling of the current
situation. With some lingering uncertainty in spatial extent and
evolution, the SPC Slight Risk across much of the area is more than
reasonable.

Friday Afternoon through Thursday...

Warm and at times humid conditions will remain through the weekend
and to start the week. A reprieve from the humidity will be seen
Friday and Saturday as drier air settles in. The warmth though will
predominantly continue, especially Sunday and Monday as upper
level/thermal ridging slides east. Monday continues to look like
another day in the low 90s with 850mb temps in the low 20s deg C.
The ridging will quickly be ushered away as the western trough
begins to kick out Tuesday. As it does so, the next good opportunity
for widespread rainfall will accompany it Tuesday, including the
continued opportunity for at least some remnants of Tropical Storm
Cristobal (mainly moisture) as well. The rest of the week then looks
to return to near-normal conditions in mid 70s to low 80s and
comfortable dew points.

&&

.AVIATION.../For the 18Z TAFS through 18Z Friday afternoon/
Issued at 1232 PM CDT Thu Jun 4 2020

Main concerns within the TAF period will be scattered storms
potentially affection KALO/KMCW/KFOD this afternoon/early evening
and then another round that may affect all TAF sites overnight
between roughly 06z and 15z from NW to SE. Generally MVFR
conditions may prevail in areas of storms and VFR otherwise.

&&

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

DISCUSSION...Curtis
AVIATION...Curtis

Hazardous Weather Outlook
National Weather Service Des Moines IA
433 PM CDT Thu Jun 4 2020

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-050845-
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-
433 PM CDT Thu Jun 4 2020

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...Tonight

Scattered thunderstorms can be expected across northern Iowa into
the evening, with more storms possible into the overnight hours
area wide. Some may be severe with large hail and damaging winds.
A brief tornado cannot be ruled out overnight.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Strong to severe thunderstorms may linger across central and
southern Iowa into Friday morning, with other non-severe storms
possible later in the day south.

Other thunderstorm chances are back in the forecast around
Tuesday and Wednesday. The severe weather and heavy rain potential
for these storms will be better determined in the coming days.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed tonight and into early Friday morning.

Small

Special Weather Statement
National Weather Service Des Moines IA
334 PM CDT Thu Jun 4 2020

IAZ038-039-050-042115-
Black Hawk IA-Tama IA-Grundy IA-
334 PM CDT Thu Jun 4 2020

...SPECIAL WEATHER STATEMENT...

At 333 PM CDT, Doppler radar was tracking a strong thunderstorm near
Reinbeck, or 12 miles southeast of Grundy Center, moving east at 20
mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Traer, Reinbeck, Dysart, Lincoln and Tf Clark State Park.

LAT...LON 4229 9230 4214 9230 4221 9270 4233 9267
      4230 9227
TIME...MOT...LOC 2033Z 272DEG 18KT 4226 9258

Kotenberg

Special Weather Statement
National Weather Service Des Moines IA
342 PM CDT Thu Jun 4 2020

IAZ039-042115-
Black Hawk IA-
342 PM CDT Thu Jun 4 2020

...SPECIAL WEATHER STATEMENT...

At 342 PM CDT, Doppler radar was tracking a strong thunderstorm over
Evansdale, or near Waterloo, moving east at 25 mph.

Half inch hail will be possible with this storm.

Locations impacted include...
Waterloo, Evansdale, Jesup, La Porte City, Elk Run Heights,
Crossroads Mall, Washburn, Raymond and Gilbertville.

LAT...LON 4230 9239 4252 9234 4254 9208 4247 9208
      4247 9206 4230 9207
TIME...MOT...LOC 2042Z 279DEG 20KT 4244 9229

Kotenberg

Special Weather Statement
National Weather Service Des Moines IA
404 PM CDT Thu Jun 4 2020

IAZ036-042145-
Hamilton IA-
404 PM CDT Thu Jun 4 2020

...Strong storms may produce penny size hail...

At 404 PM CDT, Doppler radar was tracking a strong thunderstorm near
Webster City, moving east at 15 mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Williams and Blairsburg.

LAT...LON 4252 9350 4247 9350 4247 9346 4239 9346
      4246 9376 4253 9376
TIME...MOT...LOC 2104Z 278DEG 13KT 4247 9368

Kotenberg

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
414 PM CDT THU JUN 4 2020

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

0330 PM     TSTM WND DMG     EVANSDALE               42.46N 92.28W
06/04/2020                   BLACK HAWK         IA   BROADCAST MEDIA

            LARGE TREE DOWN. VIA KWWL TV VIEWER. TIME
            ESTIMATED.

&&

BSS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
421 PM CDT THU JUN 4 2020

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

0350 PM     TSTM WND GST     2 WSW EVANSDALE         42.46N 92.31W
06/04/2020  M55 MPH          BLACK HAWK         IA   MESONET

            IDOT RWIS MESONET STATION RWLI4 2 W
            EVANSDALE.

&&

BSS

Special Weather Statement
National Weather Service Des Moines IA
429 PM CDT Thu Jun 4 2020

IAZ038-039-050-042230-
Black Hawk IA-Tama IA-Grundy IA-
429 PM CDT Thu Jun 4 2020

...Strong storms may produce small hail and winds over 40 mph...

At 429 PM CDT, Doppler radar was tracking a strong thunderstorm near
Reinbeck, or 11 miles south of Cedar Falls, moving east at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Waterloo, La Porte City, Hudson, Reinbeck, Washburn, Gilbertville and
Tf Clark State Park.

LAT...LON 4230 9230 4220 9230 4221 9264 4244 9261
      4243 9206 4230 9206
TIME...MOT...LOC 2129Z 273DEG 23KT 4236 9251

Kotenberg