Severe Thunderstorm Warning 230, NWS Des Moines, IA

575 
WWUS53 KDMX 020017
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
717 PM CDT WED AUG 1 2018

IAC187-020027-
/O.CAN.KDMX.SV.W.0230.000000T0000Z-180802T0045Z/
Webster IA-
717 PM CDT WED AUG 1 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WEBSTER COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4221 9393 4233 9372 4230 9347 4204 9367
TIME...MOT...LOC 0017Z 299DEG 21KT 4225 9363 

$$

IAC015-079-169-020045-
/O.CON.KDMX.SV.W.0230.000000T0000Z-180802T0045Z/
Story IA-Boone IA-Hamilton IA-
717 PM CDT WED AUG 1 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR NORTHWESTERN STORY...NORTHEASTERN BOONE AND SOUTHEASTERN HAMILTON
COUNTIES...

At 717 PM CDT, a severe thunderstorm was located near Jewell
Junction, or 15 miles north of Ames, moving southeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Ames, Story City, Jewell Junction, Gilbert, Ellsworth, Stanhope and
Randall.

This includes Interstate 35 between mile markers 124 and 133.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4221 9393 4233 9372 4230 9347 4204 9367
TIME...MOT...LOC 0017Z 299DEG 21KT 4225 9363 

HAIL...1.00IN
WIND...60MPH
 
$$

Hagenhoff

Area Forecast Discussion
National Weather Service Des Moines IA
640 PM CDT Wed Aug 1 2018

.DISCUSSION.../Tonight through Wednesday/
Issued at 343 PM CDT Wed Aug 1 2018

Relatively quiet weather continues throughout much of the
forecast with a few isolated storms still possible this afternoon
into the evening with the cold frontal passage. Otherwise, the
focus of the forecast was on the heat building back into the
region and a periodic storm chances over the weekend into early
next week.

Cold front slowly creeping into northwest Iowa late this afternoon
will continue progress southeast this evening. The latest hires
models, especially the HRRR and ESRL HRRR, have the best handle on
the current radar trends and depictions through late this
evening. There is limited instability due to the weak shower/cloud
cover from southwest to northeast Iowa through the day and shear
remains low or even non existence. Not much going for severe
weather chances later this afternoon into the evening, but still
cannot rule out an isolated threat for now.

Surface high pressure builds into the state tonight into Thursday
providing cool and dry conditions. This high shifts east through
the day Friday and return flow begins to develop from west to
east across the forecast area. The ECMWF is a bit stronger and
faster with a shortwave to cut across the region late Saturday
into Saturday evening. Certainly looks to be a breezy and warm day
Saturday and confident to nudge up wind gusts a couple of knots.
Winds near the mix layer range from 28-36 knots but with forecast
soundings suggesting some high clouds, this should limited some of
the deep mixing. Regardless, the surface pressure gradient
increases and mixing is likely to be enough for wind gusts around
25 mph or slightly higher Saturday afternoon. 850mb temperatures
still progged to range from +20C to +22C Saturday afternoon and
Sunday afternoon, and thus warm temperatures on track for the
weekend. Surface dew points remain in the lower to middle 60s and
not anticipating significant heat index values over the weekend.

Sunday night into Monday, the ECMWF and GFS are in decent
agreement with another shortwave riding the westerly flow into
the region. Timing and location looks to be b/t 00-12z Monday and
over central to northern Iowa. Severe potential remains uncertain,
but instability increases Sunday afternoon there is decent shear
present Sunday night into Monday. Certainly something to continue
to monitor if models continue to converge on timing and location.

&&

.AVIATION.../For the 00Z TAFS through 00Z Thursday evening/
Issued at 640 PM CDT Wed Aug 1 2018

Storms have developed along a passing cold front as expected. The
front will pass southeast across the TAF locations through 06Z-07Z.
MVFR cigs/vsbys associated with FROPA and storms then again late
tonight with a potential for some patchy fog otherwise VFR
conditions will prevail. Ahead of the front southerly winds at 5-
15kts are forecast.  Behind the front, winds become northwest at
15g25kts and these are expected to become lighter further behind the
front...aft 06Z.

&&

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

&&

DISCUSSION...Podrazik
AVIATION...FAB

Hazardous Weather Outlook
National Weather Service Des Moines IA
325 PM CDT Wed Aug 1 2018

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-022030-
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-
325 PM CDT Wed Aug 1 2018

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

Isolated to scattered thunderstorms are expected to develop this
afternoon over northern Iowa. A few of the storms may reach severe
levels across northern Iowa late this afternoon and toward central
Iowa into the evening. The primary threats are large hail and strong
winds.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Additional intermittent chances for thunderstorms are forecast
Saturday through Monday. The severe weather threat is uncertain
at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed briefly this late this afternoon
and into the evening.

REV

Special Weather Statement
National Weather Service Des Moines IA
536 PM CDT WED AUG 1 2018

IAZ017-012330-
Cerro Gordo IA-
536 PM CDT WED AUG 1 2018

...Hail and Strong Winds Possible...

At 535 PM CDT, Doppler radar was tracking a strong thunderstorm near
Mason City, moving east at 20 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Mason City, Nora Springs, Mason City Municipal Airport, Rock Falls
and Portland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4321 9302 4304 9302 4314 9335 4323 9333
TIME...MOT...LOC 2235Z 279DEG 19KT 4318 9325

Hagenhoff

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
636 PM CDT WED AUG 1 2018

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

0620 PM     HAIL             3 S DUNCOMBE            42.43N 93.99W
08/01/2018  E0.75 INCH       WEBSTER            IA   TRAINED SPOTTER

&&

MJB