Severe Thunderstorm Warning 253, NWS Des Moines, IA

277 
WWUS53 KDMX 281221
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
721 AM CDT TUE AUG 28 2018

IAC147-151-281230-
/O.CAN.KDMX.SV.W.0253.000000T0000Z-180828T1300Z/
Pocahontas IA-Palo Alto IA-
721 AM CDT TUE AUG 28 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN POCAHONTAS AND
SOUTHEASTERN PALO ALTO COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4325 9380 4274 9377 4284 9444 4312 9444
      4326 9382
TIME...MOT...LOC 1220Z 266DEG 35KT 4303 9428 

$$

IAC081-091-109-197-281300-
/O.CON.KDMX.SV.W.0253.000000T0000Z-180828T1300Z/
Wright IA-Kossuth IA-Hancock IA-Humboldt IA-
721 AM CDT TUE AUG 28 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 AM CDT
FOR NORTHWESTERN WRIGHT...SOUTHERN KOSSUTH...WESTERN HANCOCK AND
NORTHERN HUMBOLDT COUNTIES...

At 720 AM CDT, a severe thunderstorm was located near Algona, moving
east at 40 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Algona, Britt, West Bend, Kanawha, Whittemore, Wesley, Livermore,
Corwith, Bode, Lu Verne, Renwick, Woden, St. Joseph, Ottosen, Hardy,
St. Benedict, Irvington, Sexton, Hutchins and Stinson Prairie State
Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 4325 9380 4274 9377 4284 9444 4312 9444
      4326 9382
TIME...MOT...LOC 1220Z 266DEG 35KT 4303 9428 

HAIL...1.25IN
WIND...60MPH
 
$$

Boksa

011 
WWUS53 KDMX 281231
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
731 AM CDT TUE AUG 28 2018

IAC081-091-109-197-281300-
/O.CON.KDMX.SV.W.0253.000000T0000Z-180828T1300Z/
Wright IA-Kossuth IA-Hancock IA-Humboldt IA-
731 AM CDT TUE AUG 28 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 AM CDT
FOR NORTHWESTERN WRIGHT...SOUTHEASTERN KOSSUTH...WESTERN HANCOCK AND
NORTHEASTERN HUMBOLDT COUNTIES...

At 730 AM CDT, a severe thunderstorm was located near Algona, moving
east at 40 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Algona, Britt, Kanawha, Wesley, Corwith, Lu Verne, St. Joseph, St.
Benedict, Irvington, Sexton, Hutchins, Stinson Prairie State Park,
Algona Municipal Airport and Aa Call State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 4283 9378 4289 9433 4311 9433 4325 9380
TIME...MOT...LOC 1230Z 268DEG 38KT 4303 9412 

HAIL...1.00IN
WIND...<50MPH
 
$$

Boksa

387 
WWUS53 KDMX 281253
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
753 AM CDT TUE AUG 28 2018

IAC081-091-109-197-281259-
/O.CAN.KDMX.SV.W.0253.000000T0000Z-180828T1300Z/
Wright IA-Kossuth IA-Hancock IA-Humboldt IA-
753 AM CDT TUE AUG 28 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WRIGHT...
SOUTHEASTERN KOSSUTH...WESTERN HANCOCK AND NORTHEASTERN HUMBOLDT
COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

Remember, a Severe Thunderstorm Warning still remains in effect for 
a small portion of southeastern Kossuth, northeast Humboldt, 
northern Wright and Hancock Counties until 830 AM CDT. 

LAT...LON 4283 9378 4289 9433 4311 9433 4325 9380
TIME...MOT...LOC 1246Z 268DEG 38KT 4304 9384 

$$

Boksa

Area Forecast Discussion
National Weather Service Des Moines IA
639 AM CDT Tue Aug 28 2018

.SHORT TERM.../Today through Tonight/
Issued at 357 AM CDT Tue Aug 28 2018

At 3 AM a cold front was nosing into far northwest Iowa while aloft
several weak impulses were traversing north central and northwest
Iowa and locations to the west.  Moderate instability exists across
the northwest Iowa and locations north and west of the frontal
boundary along with sufficient deep shear to the continuation of
thunderstorms through the early morning hours.  Soundings appear to
indicate an elevated warm layer above the cold front and this is
likely where storms are initiating.  As long as the shear remains,
the threat for large hail...along with some wind threat will
persist.  Somewhat troubling is that the CAM models have recently
weakened or delayed the moving of these storms into the forecast
area until 12Z or later.  Radar imagery is not confirming this as
robust storms are just a few counties away.  Movement however does
indicate that they may just graze our northwest/northern counties.
Either way, the trend is for storms to gradually weaken as the low
level jet weakens through mid morning but not before a few severe
storms make their way across northern Iowa.

Later today and especially this afternoon and evening, instability
will be very strong along and ahead of the cold front and ongoing
storms are expected to become more widespread and intensify. Further
south, in an area of warm advection ahead of the front, additional
storms will break out mid to late morning.  It is unclear at this
point if the southern area will see much convection but if they do
develop the resultant convective debris may lessen the severe threat
at least initially.  The latest CAM models suggest that even if
storms initiate in the warm sector, there will be some clearing and
time for destabilization before the front comes through later this
afternoon and evening across the southeast.  Bottom line is that is
will be a stormy day today with a severe threat far north early this
morning then southeast during peak heating into the early evening.
QPF pretty impressive as well with over an inch forecast and higher
amounts possible in stronger storms.  Not really concerned with
flash flooding at this point as higher QPF amounts progged over D1
to D3 drought areas and with crops still capable of absorbing quite
a bit of water.

Front passes through late tonight ending the threat of storms/heavy
rainfall.  The bulk of the storms should be done by 06Z with
lingering showers and a few storms through 09Z.  Cooler and less
humid air will arrive by 12Z Wednesday.

.LONG TERM.../Wednesday through Monday/
Issued at 357 AM CDT Tue Aug 28 2018

Westerly flow aloft to be in place Wednesday with the cold front
expected to bring storms chances to the area today to have pushed to
the south of the state with an area of high pressure building into
the state. This will bring dry and cool conditions as h85 temps
falling to around +10C aloft. The area of high pressure will remain
in place into Thursday before return flow sets back up and
WAA/moisture advection returns to the state Thursday night into
Friday. A weak shortwave trough will push east through the broader
westerlies aloft and bring chances for storms back to the area
Thursday night. Broad lift will remain in place into Friday/Saturday
with a broad upper level trough across the central US and a sfc
trough axis in place across the state. This will allow for continued
chances for storms to end the week and into the weekend. The weakly
defined surface boundary to linger across the south into Sunday with
high pressure sliding across the northern portion of the state. This
should confine the better chances for precip to the central/south
late in the weekend. The boundary to then lift back to the north
into early next week with continued chances for storms with general
troughiness in the western US and westerly to southwesterly flow
aloft across Iowa.

Temperatures will initially be cooler across the state Wednesday
with the cool airmass in place aloft with highs expected to top out
in the low to mid 70s and lows in the 50s. Slightly warmer
conditions into Thursday with highs in the mid 70s to around 80,
with a return to mainly low to mid 80s expected for late this week
and into the weekend. Humidity will return to the area Friday and
beyond as dewpoints climb back into the upper 60s to lower 70s.

&&

.AVIATION.../For the 12Z TAFS through 12Z Wednesday morning/
Issued at 639 AM CDT Tue Aug 28 2018

Cold front to slowly move across TAF locations today.  Strong
thunderstorms with large hail possible across far northern Iowa this
morning before weakening some.  Additional strong storms tied to
frontal boundary in the afternoon with peak heating across eastern
TAF locations possibly impacting KDSM as well...especially early on.
Front to move out of the state after 09Z with improving conditions.

&&

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

&&

SHORT TERM...FAB
LONG TERM...Beerends
AVIATION...FAB

Hazardous Weather Outlook
National Weather Service Des Moines IA
405 AM CDT Tue Aug 28 2018

IAZ028-037>039-048>050-059>062-070>075-081>086-092>097-291100-
Bremer-Hardin-Grundy-Black Hawk-Story-Marshall-Tama-Dallas-Polk-
Jasper-Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-
Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
405 AM CDT Tue Aug 28 2018

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...Today and tonight

Strong to severe thunderstorms will be possible by mid to late
afternoon into tonight. The primary threats are damaging winds
and large hail, but an isolated tornado or two cannot be ruled
out. Locally heavy rainfall is also possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Periodic chances for storms return Thursday night through
Monday. The threat of severe weather is low at this time.

.SPOTTER INFORMATION STATEMENT...

Spotters are likely to be needed this afternoon into tonight.

IAZ004>007-015>017-023>027-033>036-044>047-057-058-291100-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Sac-Calhoun-Webster-
Hamilton-Crawford-Carroll-Greene-Boone-Audubon-Guthrie-
405 AM CDT Tue Aug 28 2018

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...Today and tonight

Thunderstorms are possible today into tonight. A strong to
possibly severe storm is possible early this morning. Large
hail or damaging wind gusts are the main threat early this
morning. Otherwise a strong storm may be possible with gusty
winds and small hail from late morning through this evening.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Periodic chances for storms return Thursday night through
Monday. The threat of severe weather is low at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed early this morning, otherwise
it is not anticipated.

MJB

Special Weather Statement
National Weather Service Des Moines IA
310 AM CDT Tue Aug 28 2018

IAZ004>007-015>017-281300-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Including the cities of Estherville, Algona, Forest City,
Lake Mills, Northwood, Manly, Emmetsburg, Garner, Britt, Kanawha,
Mason City, and Clear Lake
310 AM CDT Tue Aug 28 2018

...AREAS OF FOG DEVELOPING ACROSS NORTHERN IOWA...

Fog is developing across northern Iowa and will likely persist
into the morning commute hours. Visibility has dropped to around
a mile with local visibilities across Emmet and Palo Alto counties
as low as a quarter mile at times. Those traveling across
northern Iowa this morning should be prepared for lowered
visibilities especially in low lying areas. During the morning
commute, slow down and allow more space between yourself and the
vehicle ahead of you and remember to use low beams.

FAB

Special Weather Statement
National Weather Service Des Moines IA
656 AM CDT TUE AUG 28 2018

IAZ023-281230-
Pocahontas IA-
656 AM CDT TUE AUG 28 2018

...NICKEL HAIL AND GUSTY WINDS POSSIBLE...

At 655 AM CDT, Doppler radar was tracking a strong thunderstorm over
Albert City, or 13 miles west of Pocahontas, moving east at 45 mph.

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

Locations impacted include...
Pocahontas, Laurens, Rolfe, Palmer, Havelock, Varina and Pocahontas
Municipal Airport.

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 4287 9491 4282 9453 4263 9458 4264 9492
TIME...MOT...LOC 1155Z 270DEG 39KT 4277 9492

Beerends