Severe Thunderstorm Warning 1, NWS Des Moines, IA

Area Forecast Discussion
National Weather Service Des Moines IA
1138 AM CST Sat Mar 5 2022

...Updated for the 18z Aviation Discussion...

.SHORT TERM.../Today through Tonight/
Issued at 415 AM CST Sat Mar 5 2022

Key Messages:
-- Showers, elevated storms through around early afternoon with any
   severe risk being hail
-- Higher risk of severe weather starting mid-afternoon into
   early this evening - tornadoes, damaging wind gusts, hail all
   possible
-- Period of gusty winds after the storms tonight

Current radar echoes show scattered rain showers with embedded
thunderstorms, mainly impacting central Iowa early this morning as
the low level jet remains prominent. Overall storms stayed below
severe criteria, with periods of downpours at times and isolated
radar-indicated under half-inch hail. Showers with embedded
thunderstorms are expected to continue through much of the morning
today as the warm sector of the low pressure system continues to
push through the state. Elevated hail looks to be the main threat
through the morning to early afternoon. The main concern for
possible severe weather arrives towards the afternoon to early
evening, as the surface low moves over the state. Model soundings
suggest the presence of steep lapse rates with high shear during
this period, however instability needed is in question as this will
depend on cloud cover through the day. The SPC HREF suggests some
clearing in cloud cover across southwest Iowa into the afternoon
hours that would tap into this instability along the dryline. Will
have to watch how conditions evolve through the day and will make
adjustments as needed. Main threats with any surface based
convection that results, if conditions are met, would be hail,
damaging wind gusts, and potentially a few tornadoes. As the cold
front arrives through the evening, temperatures will drop from west
to east. This strong cold air advection will bring windy conditions
as the tightened gradient slides across the region. After
coordinating with neighboring offices, have decided to issue a Wind
Advisory across much of central and southern Iowa from 00z tonight
through 09z Sunday. Most precipitation will have exited the state by
the end of the evening. However a transition to a brief period of
freezing rain may be possible through the early morning Sunday
across northern Iowa with no accumulations. All precipitation is
expected to move out of the state by sunrise Sunday, with attention
turning to the next system later in the day.

&&

.LONG TERM.../Sunday through Friday/
Issued at 415 AM CST Sat Mar 5 2022

Key Messages:
-- Mainly snow Sunday night into Monday, particularly
   southeastern Iowa
-- Another bout of wintry precipitation Thursday followed by
   unseasonably cold air

Details: A shortwave trough will be ejecting from the central
Rockies Sunday evening and there will be a stalled boundary well
south of Iowa stretching from the southern Plains into the Ozarks.
Moisture will be overrunning this boundary with isentropic lift in
the 295-305K layer and low level QG convergence will move from the
central Plains into Missouri and southern and central Iowa. This
will lead to moistening of the profile per forecast soundings and
yield rain over the southeastern forecast area and snow elsewhere
Sunday evening. As temperatures cool, should see predominately snow.
However, there are forecast soundings that show intermittent ice
lose, which would result in brief bouts of freezing rain over
southeastern areas late Sunday night into Monday morning. Icing
would be generally a glaze to a few hundredths. As the shortwave
trough moves over and east of the region on Monday, subsidence and
profile drying will bring an end to the wintry precipitation Monday
morning. Snow ratios will be below 10:1 initially, but will increase
as colder air filters in and end above in the 12-13:1 range. Snow
accumulations are expected to largely be around 1 inch or less
across much of the area. The exception may be over southeastern and
far south central Iowa where WPC superensemble shows closer to an
1.5 to 2 inches. However, this will somewhat depend on what amount
of wintry mix occurs, which will lower. Current forecast is below
the above over the south central and southeastern areas so will need
to monitor precipitation type over the next 24 to 36 hours to
possibly adjust snow amounts up.

High pressure will move spread into the region from the west later
Monday through Tuesday departing on Wednesday. It's departure will
be aided by a southward diving cold front on Wednesday, which will
lose its momentum and stall over Iowa. As surface low pressure moves
out from the Colorado Rockies and rides along the front ahead of a
longwave, positively tilted trough over the western US, increasing
low level thermal lift and QG convergence will overspread the state.
This will result in precipitation that will be largely snow, but
could be rain at times during the day over southern portions of the
state. The low will pass southeast of the state, though the CMC and
ECMWF are closer to Iowa than the GFS. At least breezy winds should
result later Thursday into Thursday night, which will bring
unusually cold air for March into the state with highs 15 to 20
degrees below normal to end the week.

&&

.AVIATION.../For the 18Z TAFS through 18Z Sunday afternoon/
Issued at 1138 AM CST Sat Mar 5 2022

Scattered thunderstorms and areas of low ceilings will produce
periodic IFR or lower conditions at the terminals this afternoon
and evening, which are described using VC and TEMPO groups in the
18Z TAFs. Amendments are likely based on short term convective
trends. The storms will move out around 00-02Z or so, after which
lingering MVFR ceilings will affect primarily the northern
terminals tonight before clearing out. Strong WNW winds are also
forecast overnight and may create LLWS and crosswind issues on
some runways, especially those with N-S orientation.

&&

.HYDROLOGY...
Issued at 339 PM CST Fri Mar 4 2022

Little has changed from previous thinking with respect to river
concerns. With event QPF generally a half inch to an inch,
possibly isolated 1"+, RFC ensemble and contingency forecasts
suggest within bank rises. Even with frost still in the ground and
enhancing runoff, dry soils in Abnormally Dry to Moderate Drought
areas will likely not produce sufficient runoff to reach flood
stage. However, within bank rises may still increase the potential
for ice jams, especially in more typical areas, so localized
flooding would still be possible in those locations early next
week.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 6 PM this evening to 3 AM CST Sunday for
IAZ034>039-044>050-057>062-070>075-081>086-092>097.

&&

SHORT TERM...Bury/Ansorge
LONG TERM...Ansorge
AVIATION...Lee
HYDROLOGY...Small

Hazardous Weather Outlook
National Weather Service Des Moines IA
1225 PM CST Sat Mar 5 2022

IAZ004>007-015>017-023>028-033>039-044>050-057-058-070-061830-
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-Cass-
1225 PM CST Sat Mar 5 2022

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

There is a slight risk for severe weather later this afternoon
into early this evening. Damaging wind gusts, tornadoes, and hail
will be possible during this timeframe.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Rainfall from the Saturday storms will runoff into area rivers
and cause within bank rises. Where river ice remains, particularly
over northern Iowa, it is possible ice jams could develop and
cause localized flooding Sunday or early next week.

A wintry mix and snow is possible Sunday night into Monday. At
least minor snow accumulations are possible with the highest
confidence in accumulations over southeastern Iowa.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed this afternoon and early evening.

IAZ059>062-071>075-081>086-092>097-061830-
Dallas-Polk-Jasper-Poweshiek-Adair-Madison-Warren-Marion-Mahaska-
Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-
Wayne-Appanoose-Davis-
1225 PM CST Sat Mar 5 2022

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

There is an enhanced risk for severe weather later this afternoon
into early this evening. Damaging wind gusts, tornadoes, and hail
will be possible during this timeframe.

A Wind Advisory is in effect for central and southern Iowa
tonight. Please refer to the National Weather Service website at
weather.gov/desmoines for further details.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Rainfall from the Saturday storms will runoff into area rivers
and cause within bank rises. Where river ice remains, particularly
over northern Iowa, it is possible ice jams could develop and
cause localized flooding Sunday or early next week.

A wintry mix and snow is possible Sunday night into Monday. At
least minor snow accumulations are possible with the highest
confidence in accumulations over southeastern Iowa.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed this afternoon and early evening.

Special Weather Statement
National Weather Service Des Moines IA
925 AM CST Sat Mar 5 2022

IAZ083-084-094-095-051615-
Clarke IA-Lucas IA-Wayne IA-Decatur IA-
925 AM CST Sat Mar 5 2022

...A strong thunderstorm will impact portions of Lucas, northern
Decatur, northern Wayne and eastern Clarke Counties through 1015 AM
CST...

At 924 AM CST, Doppler radar was tracking a strong thunderstorm near
Leon, moving northeast at 60 mph.

HAZARD...Winds in excess of 30 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Chariton.

This includes Interstate 35 between mile markers 15 and 38.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4088 9398 4111 9376 4116 9351 4116 9325
      4082 9310 4065 9370
TIME...MOT...LOC 1524Z 230DEG 52KT 4080 9367

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

Krull

Special Weather Statement
National Weather Service Des Moines IA
949 AM CST Sat Mar 5 2022

IAZ074-084-085-051615-
Marion IA-Lucas IA-Monroe IA-
949 AM CST Sat Mar 5 2022

...A strong thunderstorm will impact portions of western Monroe,
eastern Lucas and southeastern Marion Counties through 1015 AM CST...

At 949 AM CST, Doppler radar was tracking a strong thunderstorm near
Chariton, moving northeast at 55 mph.

HAZARD...Winds in excess of 30 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of western Monroe,
eastern Lucas and southeastern Marion Counties, including the
following locations... Marysville, Melrose, Lovilia and Hamilton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4110 9323 4131 9300 4102 9276 4090 9306
      4090 9314
TIME...MOT...LOC 1549Z 237DEG 47KT 4095 9328

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

Krull

Special Weather Statement
National Weather Service Des Moines IA
1251 PM CST Sat Mar 5 2022

IAZ058-059-071-072-081-082-051915-
Guthrie IA-Adams IA-Adair IA-Union IA-Madison IA-Dallas IA-
1251 PM CST Sat Mar 5 2022

...A strong thunderstorm will impact portions of northwestern
Madison, northwestern Union, southeastern Guthrie, northeastern
Adams, southwestern Dallas and Adair Counties through 115 PM CST...

At 1250 PM CST, Doppler radar was tracking a strong thunderstorm near
Greenfield, moving northeast at 65 mph.

HAZARD...Winds in excess of 30 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Greenfield around 1255 PM CST.
  Stuart around 110 PM CST.

Other locations in the path of this storm include Earlham.

This includes Interstate 80 between mile markers 85 and 110.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4108 9449 4119 9469 4171 9432 4146 9387
TIME...MOT...LOC 1850Z 214DEG 56KT 4122 9452

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

Krull

Special Weather Statement
National Weather Service Des Moines IA
110 PM CST Sat Mar 5 2022

IAZ059-060-072-073-051945-
Polk IA-Madison IA-Dallas IA-Warren IA-
110 PM CST Sat Mar 5 2022

...A strong thunderstorm will impact portions of Polk, northeastern
Madison, southeastern Dallas and northwestern Warren Counties through
145 PM CST...

At 110 PM CST, Doppler radar was tracking a strong thunderstorm near
Winterset, moving northeast at 65 mph.

HAZARD...Winds in excess of 30 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Norwalk, Des Moines Int'l Airport, Valley West Mall and Jordan
  Creek Town Center around 125 PM CST.
  West Des Moines, Johnston, Clive, Windsor Heights, Drake Stadium
  And Knapp Center, Iowa Events Center, Principal Park, Merle Hay
  Mall and Southridge Mall around 130 PM CST.

Other locations in the path of this storm include Des Moines, Ankeny,
Pleasant Hill, Saylorville, Iowa State Fairgrounds, Altoona,
Bondurant, Prairie Meadows and Adventureland Amusement Park.

This includes the following highways...
 Interstate 35 between mile markers 54 and 72, and between mile
markers 87 and 94.
 Interstate 80 between mile markers 114 and 146.
 Interstate 235 between mile markers 1 and 14.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4134 9409 4184 9371 4163 9335 4160 9335
      4160 9333 4156 9333 4124 9392
TIME...MOT...LOC 1910Z 220DEG 56KT 4136 9392

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

Krull

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special Weather Statement
National Weather Service Des Moines IA
151 PM CST Sat Mar 5 2022

IAZ048-049-061-052015-
Story IA-Jasper IA-Marshall IA-
151 PM CST Sat Mar 5 2022

...A strong thunderstorm will impact portions of southeastern Story,
Marshall and northwestern Jasper Counties through 215 PM CST...

At 151 PM CST, Doppler radar was tracking a strong thunderstorm near
Baxter, or 10 miles northwest of Newton, moving northeast at 75 mph.

HAZARD...Winds in excess of 30 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Baxter around 155 PM CST.

Other locations in the path of this storm include Marshalltown.

This includes Interstate 80 between mile markers 154 and 160.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4165 9322 4174 9335 4221 9311 4221 9277
      4217 9277 4217 9276 4211 9277 4187 9277
TIME...MOT...LOC 1951Z 225DEG 65KT 4178 9322

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...30 MPH

Krull