Winter Storm Warning 5, NWS Des Moines, IA

794 
WWUS43 KDMX 160741
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
241 AM CDT Thu Apr 16 2020

...Spring Heavy Snow to Impact Southern Iowa Today and Tonight...

.A strong spring storm will bring wintry weather to portions of 
central southern Iowa today and tonight. A heavy band of snow is 
forecast to set up across southern portions of Iowa, generally 
along and south of the Highway 34 corridor to the Missouri border.
A sharp cutoff of the accumulating snow is anticipated in central
Iowa in the vicinity of the Interstate 80 corridor as north of 
this line likely to just only light snow amounts. Winds will range
from 10 to 20 mph how the wetter consistency of the expected
snowfall will result in only minor blowing. Some power outages and
tree damage may occur over southern Iowa as the wet and heavy 
snow sticks to trees and powerlines. 

IAZ081>086-092>097-161545-
/O.EXT.KDMX.WS.W.0005.200416T1400Z-200417T1200Z/
Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-
Wayne-Appanoose-Davis-
Including the cities of Corning, Creston, Osceola, Chariton, 
Albia, Ottumwa, Bedford, Lenox, New Market, Mount Ayr, Lamoni, 
Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
241 AM CDT Thu Apr 16 2020

...WINTER STORM WARNING NOW IN EFFECT FROM 9 AM THIS MORNING TO
7 AM CDT FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 6 to 9 
  inches.

* WHERE...Southern Iowa.

* WHEN...From 9 AM this morning to 7 AM CDT Friday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions will impact the evening commute. Wet, heavy snow will
  stick to power lines and trees and will create a risk for power
  outages and some tree damage.

* ADDITIONAL DETAILS...Very heavy snowfall rates of one to two
  inches an hour are possible this afternoon and evening. Road conditions
  will deteriorate quickly. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ057>062-161545-
/O.EXB.KDMX.WW.Y.0018.200416T1700Z-200417T1200Z/
Audubon-Guthrie-Dallas-Polk-Jasper-Poweshiek-
Including the cities of Audubon, Exira, Guthrie Center, Panora, 
Bayard, Casey, Perry, Waukee, Adel, Des Moines, Newton, 
and Grinnell
241 AM CDT Thu Apr 16 2020

...WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO 7 AM CDT
FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 1 to 4 
  inches.

* WHERE...Portions of central Iowa mainly along and south of
  Interstate 80.

* WHEN...From noon today to 7 AM CDT Friday.

* IMPACTS...Icy travel conditions may develop later this afternoon
  and into the evening. 

* ADDITIONAL DETAILS...The main impacts will arrive later this
  afternoon and into the evening. Sharp gradients are possible
  across the advisory area with the lightest amounts over the
  northern areas and heaviest to the south.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ070>075-161545-
/O.EXT.KDMX.WW.Y.0018.200416T1700Z-200417T1200Z/
Cass-Adair-Madison-Warren-Marion-Mahaska-
Including the cities of Atlantic, Greenfield, Stuart, Adair, 
Fontanelle, Winterset, Earlham, Indianola, Norwalk, Carlisle, 
Pella, Knoxville, and Oskaloosa
241 AM CDT Thu Apr 16 2020

...WINTER WEATHER ADVISORY NOW IN EFFECT FROM NOON TODAY TO 7 AM
CDT FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 6 
  inches.

* WHERE...Portions of central and southern Iowa.

* WHEN...From noon today to 7 AM CDT Friday.

* IMPACTS...Travel could be difficult. The hazardous conditions
  may impact the evening commute.

* ADDITIONAL DETAILS...Localized power outages are possible due to
  the wet and heavy snow sticks to trees and powerlines. A period
  of one inch per hour snowfall rates are possible. 

PRECAUTIONARY/PREPAREDNESS
  ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

456 
WWUS43 KDMX 161532
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
1032 AM CDT Thu Apr 16 2020

...Spring Heavy Snow to Impact Southern Iowa Today and Tonight...

.A strong spring storm will continue to bring wintry weather to 
portions of central and southern Iowa through the remainder of
today into tonight. A heavy band of snow is forecast to set up 
across southern portions of Iowa, generally along and south of the
Highway 34 corridor to the Missouri border. A sharp cutoff of the
accumulating snow is anticipated in central Iowa in the vicinity 
of the Interstate 80 corridor. North of this line, there will  
likely be only light snow amounts. Winds will range from 10 to 20
mph, but with the wetter consistency of the expected snowfall this  
will result in only minor blowing. Some power outages and tree 
damage may occur over southern Iowa as the wet and heavy snow 
sticks to trees and power lines.

IAZ081>086-092>097-162345-
/O.CON.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-
Wayne-Appanoose-Davis-
Including the cities of Corning, Creston, Osceola, Chariton, 
Albia, Ottumwa, Bedford, Lenox, New Market, Mount Ayr, Lamoni, 
Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
1032 AM CDT Thu Apr 16 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM CDT FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 6 to 9 
  inches.

* WHERE...Southern Iowa.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions will impact this evening's commute. Wet, heavy snow 
  will stick to power lines and trees and will create a risk for 
  power outages and some tree damage.

* ADDITIONAL DETAILS...Very heavy snowfall rates of one to two 
  inches an hour are possible this afternoon and evening. Road 
  conditions will deteriorate quickly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ057>062-070>075-162345-
/O.CON.KDMX.WW.Y.0018.200416T1700Z-200417T1200Z/
Audubon-Guthrie-Dallas-Polk-Jasper-Poweshiek-Cass-Adair-Madison-
Warren-Marion-Mahaska-
Including the cities of Audubon, Exira, Guthrie Center, Panora, 
Bayard, Casey, Perry, Waukee, Adel, Des Moines, Newton, Grinnell,
Atlantic, Greenfield, Stuart, Adair, Fontanelle, Winterset, 
Earlham, Indianola, Norwalk, Carlisle, Pella, Knoxville, 
and Oskaloosa
1032 AM CDT Thu Apr 16 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT
FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 1 to 4 
  inches.

* WHERE...Portions of central Iowa mainly along and south of 
  Interstate 80.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slick travel conditions may develop later this
  afternoon into this evening.

* ADDITIONAL DETAILS...The main impacts will arrive later this
  afternoon and into the evening. Sharp snow gradients are 
  possible across the advisory area with the lightest amounts over
  the northern areas and heaviest to the south.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

Ansorge

179 
WWUS43 KDMX 162039
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
339 PM CDT Thu Apr 16 2020

...Spring Heavy Snow to Impact Southern Iowa Through Tonight...

.Widespread accumulating snow remains on track across central to
southern Iowa through tonight. Intense snowfall rates of 1 to 2
inches per hour can be expected at times over southern Iowa and
will produce one half mile visibility or less this evening. Travel
is likely to be difficult, especially south of Interstate 80 and
in particular, along and south of Highway 34 corridor where the
heaviest snowfall is forecast. Some power outages and tree damage
may occur over southern Iowa as the wet and heavy snow sticks to 
trees and power lines.

IAZ081>086-092>097-170445-
/O.CON.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-
Wayne-Appanoose-Davis-
Including the cities of Corning, Creston, Osceola, Chariton, 
Albia, Ottumwa, Bedford, Lenox, New Market, Mount Ayr, Lamoni, 
Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
339 PM CDT Thu Apr 16 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM CDT FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 6 to 9
  inches with isolated totals over 10 inches possible. 

* WHERE...Southern Iowa.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Travel are expected be very difficult. The hazardous
  conditions will impact the evening commute. Wet, heavy snow may
  stick to power lines and trees and create a risk for power 
  outages and some tree damage.

* ADDITIONAL DETAILS...Very heavy snowfall rates of one to two
  inches an hour are possible this afternoon and evening. Road
  conditions may deteriorate quickly and visibility is going to 
  be reduced to less than one half mile at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ057>062-070>075-170445-
/O.CON.KDMX.WW.Y.0018.000000T0000Z-200417T1200Z/
Audubon-Guthrie-Dallas-Polk-Jasper-Poweshiek-Cass-Adair-Madison-
Warren-Marion-Mahaska-
Including the cities of Audubon, Exira, Guthrie Center, Panora, 
Bayard, Casey, Perry, Waukee, Adel, Des Moines, Newton, Grinnell,
Atlantic, Greenfield, Stuart, Adair, Fontanelle, Winterset, 
Earlham, Indianola, Norwalk, Carlisle, Pella, Knoxville, 
and Oskaloosa
339 PM CDT Thu Apr 16 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT
FRIDAY...

* WHAT...Snow expected. A sharp gradient of snowfall totals
  resulting in a wide range. Generally, 1 to 3 inches north of
  Interstate 80 and 2 to 6 inches further south of Interstate 80. 

* WHERE...Portions of central Iowa mainly along and south of
  Interstate 80. Again, higher totals closer to Highway 92
  corridor from Oskaloosa, Knoxville, Winterset and west to
  Atlantic.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slick travel conditions may develop later this
  afternoon into this evening as well as reduced visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

887 
WWUS43 KDMX 170223
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
923 PM CDT Thu Apr 16 2020

...Spring Heavy Snow to Impact Southern Iowa Through Tonight...

.A strong spring storm will produce moderate to heavy snow 
tonight across the southern half of Iowa with highest snowfall 
rates near the Missouri border. Unseasonably high snow totals are
forecast in the warning area before the snow ends toward daybreak
on Friday. 

IAZ081>086-092>097-171030-
/O.CON.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-
Wayne-Appanoose-Davis-
Including the cities of Corning, Creston, Osceola, Chariton, 
Albia, Ottumwa, Bedford, Lenox, New Market, Mount Ayr, Lamoni, 
Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
923 PM CDT Thu Apr 16 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM CDT FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 6 to 12
  inches with isolated totals over 12 inches possible.

* WHERE...Southern Iowa.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Travel is expected to be very difficult, especially as
  the night progresses and pavement temperatures fall below
  freezing. Wet, heavy snow may stick to power lines and trees 
  and create a risk for power outages and some tree damage.

* ADDITIONAL DETAILS...Very heavy snowfall rates of one to two
  inches an hour are possible into tonight. Low visibilities are
  expected with the heavy snow along with difficult travel. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ057>062-070>075-171030-
/O.CON.KDMX.WW.Y.0018.000000T0000Z-200417T1200Z/
Audubon-Guthrie-Dallas-Polk-Jasper-Poweshiek-Cass-Adair-Madison-
Warren-Marion-Mahaska-
Including the cities of Audubon, Exira, Guthrie Center, Panora, 
Bayard, Casey, Perry, Waukee, Adel, Des Moines, Newton, Grinnell,
Atlantic, Greenfield, Stuart, Adair, Fontanelle, Winterset, 
Earlham, Indianola, Norwalk, Carlisle, Pella, Knoxville, 
and Oskaloosa
923 PM CDT Thu Apr 16 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT
FRIDAY...

* WHAT...Snow expected. A sharp gradient of snowfall totals
  resulting in a wide range. Generally, 1 to 2 inches north of 
  Interstate 80 and 2 to 6 inches further south of Interstate 80.

* WHERE...Portions of central Iowa mainly along and south of 
  Interstate 80. Again, higher totals closer to Highway 92 
  corridor from Oskaloosa, Knoxville, Winterset and west to 
  Atlantic.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slick travel conditions are expected overnight as
  pavement temperatures fall below freezing. Visibilities may also
  be restricted due to the falling snow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling.

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

468 
WWUS43 KDMX 170747
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
247 AM CDT Fri Apr 17 2020

...Snow Will Gradually Diminish This Morning...

.Snow will continue to diminish this morning. Little to no
additional accumulations are anticipated after daybreak.

IAZ081>086-092>097-171200-
/O.CON.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Adams-Union-Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-
Wayne-Appanoose-Davis-
Including the cities of Corning, Creston, Osceola, Chariton, 
Albia, Ottumwa, Bedford, Lenox, New Market, Mount Ayr, Lamoni, 
Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
247 AM CDT Fri Apr 17 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM CDT THIS
MORNING...

* WHAT...Snow ending. Total snow accumulations of 6 to 12 inches 
  with isolated totals over 12 inches possible.

* WHERE...Southern Iowa.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slippery conditions are expected yet early this 
  morning then road conditions will improve quickly during the 
  daytime hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ057>062-070>075-171200-
/O.CON.KDMX.WW.Y.0018.000000T0000Z-200417T1200Z/
Audubon-Guthrie-Dallas-Polk-Jasper-Poweshiek-Cass-Adair-Madison-
Warren-Marion-Mahaska-
Including the cities of Audubon, Exira, Guthrie Center, Panora, 
Bayard, Casey, Perry, Waukee, Adel, Des Moines, Newton, Grinnell,
Atlantic, Greenfield, Stuart, Adair, Fontanelle, Winterset, 
Earlham, Indianola, Norwalk, Carlisle, Pella, Knoxville, 
and Oskaloosa
247 AM CDT Fri Apr 17 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT THIS
MORNING...

* WHAT...Snow Ending. A sharp gradient of snowfall totals 
  resulting in a wide range. Generally, 1 to 2 inches north of 
  Interstate 80 and 2 to 6 inches further south of Interstate 80.

* WHERE...Portions of central Iowa mainly along and south of 
  Interstate 80. Again, higher totals closer to Highway 92 
  corridor from Oskaloosa, Knoxville, Winterset and west to 
  Atlantic.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slippery conditions are possible yet early this 
  morning then road conditions will improve quickly during the 
  daytime hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

202 
WWUS43 KDMX 170900
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
400 AM CDT Fri Apr 17 2020

...Snow Will Gradually Diminish This Morning...

.Snow will continue to diminish this morning. Little to no
additional accumulations are anticipated after daybreak.

IAZ081-082-092-093-171000-
/O.CAN.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Adams-Union-Taylor-Ringgold-
Including the cities of Corning, Creston, Bedford, Lenox, 
New Market, and Mount Ayr
400 AM CDT Fri Apr 17 2020

...WINTER STORM WARNING IS CANCELLED...

The accumulating snow is ending and conditions will continue to
improve this morning.

$$

IAZ057>060-070>073-171000-
/O.CAN.KDMX.WW.Y.0018.000000T0000Z-200417T1200Z/
Audubon-Guthrie-Dallas-Polk-Cass-Adair-Madison-Warren-
Including the cities of Audubon, Exira, Guthrie Center, Panora, 
Bayard, Casey, Perry, Waukee, Adel, Des Moines, Atlantic, 
Greenfield, Stuart, Adair, Fontanelle, Winterset, Earlham, 
Indianola, Norwalk, and Carlisle
400 AM CDT Fri Apr 17 2020

...WINTER WEATHER ADVISORY IS CANCELLED...

The accumulating snow is ending and conditions will continue to
improve this morning.

$$

IAZ083>086-094>097-171200-
/O.CON.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Clarke-Lucas-Monroe-Wapello-Decatur-Wayne-Appanoose-Davis-
Including the cities of Osceola, Chariton, Albia, Ottumwa, 
Lamoni, Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
400 AM CDT Fri Apr 17 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM CDT THIS
MORNING...

* WHAT...Snow ending. Total snow accumulations of 6 to 12 inches 
  with isolated totals over 12 inches possible.

* WHERE...Southern Iowa.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slippery conditions are expected yet early this 
  morning then road conditions will improve quickly during the 
  daytime hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

IAZ061-062-074-075-171200-
/O.CON.KDMX.WW.Y.0018.000000T0000Z-200417T1200Z/
Jasper-Poweshiek-Marion-Mahaska-
Including the cities of Newton, Grinnell, Pella, Knoxville, 
and Oskaloosa
400 AM CDT Fri Apr 17 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 7 AM CDT THIS
MORNING...

* WHAT...Snow Ending. A sharp gradient of snowfall totals 
  resulting in a wide range. Generally, 1 to 2 inches north of 
  Interstate 80 and 2 to 6 inches further south of Interstate 80.

* WHERE...Portions of central Iowa mainly along and south of 
  Interstate 80. Again, higher totals closer to Highway 92 
  corridor from Oskaloosa, Knoxville, Winterset and west to 
  Atlantic.

* WHEN...Until 7 AM CDT Friday.

* IMPACTS...Slippery conditions are possible yet early this 
  morning then road conditions will improve quickly during the 
  daytime hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

657 
WWUS43 KDMX 171202
WSWDMX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Des Moines IA
702 AM CDT Fri Apr 17 2020

...Snowfall coming to an end in central and southern Iowa...

IAZ083>086-094>097-171315-
/O.EXP.KDMX.WS.W.0005.000000T0000Z-200417T1200Z/
Clarke-Lucas-Monroe-Wapello-Decatur-Wayne-Appanoose-Davis-
Including the cities of Osceola, Chariton, Albia, Ottumwa, 
Lamoni, Leon, Corydon, Seymour, Allerton, Humeston, Centerville, 
and Bloomfield
702 AM CDT Fri Apr 17 2020

...WINTER STORM WARNING HAS EXPIRED...

$$

IAZ061-062-074-075-171315-
/O.EXP.KDMX.WW.Y.0018.000000T0000Z-200417T1200Z/
Jasper-Poweshiek-Marion-Mahaska-
Including the cities of Newton, Grinnell, Pella, Knoxville, 
and Oskaloosa
702 AM CDT Fri Apr 17 2020

...WINTER WEATHER ADVISORY HAS EXPIRED...

$$

For more information from the National Weather Service visit
https://weather.gov/desmoines

Area Forecast Discussion
National Weather Service Des Moines IA
633 PM CDT Wed Apr 15 2020

...Updated 00z Aviation...

.DISCUSSION.../Tonight through Wednesday/
Issued at 346 PM CDT Wed Apr 15 2020

The snow overnight Tuesday into this morning aside, we couldn't
escape a day without some flurries (or sprinkles) across parts of
central Iowa. HRRR and RAP soundings show the moisture depth a bit
greater than yesterday's model runs and within the dendritic growth
zone (DGZ) with some elevated instability. While not as robust as
Monday or Tuesday with large scale subsidence overhead, this has
allowed for flurries or sprinkles to pass over portions of our
northwest forecast area into our central and southeast counties this
afternoon. Unfortunately, this will not be the last snow mention in
this discussion.

While a broad trough remains carved out across the CONUS, an
embedded, potent shortwave coming into the Pacific Northwest this
afternoon will be the feature that will bring a mid-April snow
episode to southern Iowa tomorrow into tomorrow night. As this
shortwave digs into the central Rockies, surface low pressure will
develop over the southern Plains with a baroclinic zone setting up
over eastern Kansas into Missouri. This will promote an excellent
overrunning precipitation event with isentropic lift primarily
focused in the 290 to 295K layer into northern Missouri and southern
and central Iowa. Once again, have lowered temperatures back into
the middle 30s across southern Iowa from initial guidance, which had
highs in the low 40s. Soundings continue to point toward the
temperature trending to the wet bulb once precipitation begins.
Further support for lowering temperatures will be the snow rates.
The 3z/9z SREF and 0z/12z HREF 1"/hr snow rates have a high
probability over southern Iowa during the day Thursday. These rates
are supported by frontogenetical forcing that is maximized in the
low levels with cross sections showing moderate to strong omega
within the DGZ. These rates may be enhanced by weak convective
instability in the south per HRRR sounding at LWD. With these snow
rates, should be able to dynamically cool the column for all snow
over southern Iowa with the rates also supporting accumulation on
roadways despite the date being in mid-April. There could be some
changeover or rain mix on the northern side of the precipitation
shield over central Iowa along and north of I-80 where lighter
precipitation may not foster as much dynamic cooling.

Looking at a variety of QPF guidance from EC/EPS, GFS/GEFS, HREF,
and individual models, the mesoscale band of precipitation should
set up over southern Iowa or far northern Missouri. However, the
forecast is likely still a bit too broad with the QPF and not high
enough in a narrow, yet to be determined corridor to reflect the
higher end snow amounts. HREF probability matched mean and ensemble
max show a several county area over southern Iowa with 10 to 12" and
12 to 15", respectively. Those higher amounts may be a bit too broad
in spatial extent, but do indicate the upper end potential in this
mesoscale banding event. On the northern edge of the precipitation,
there will also be a tighter gradient with rain mixing in at times
and also fighting some lower level dry air. This will put a gradient
across the Des Moines metro and other I-80 counties with several
inches possible in the southern part and an inch or less in the
northern part of these counties.

Headline wise is a quandary. This is a solid advisory for southern
Iowa, but with the upper end potential and current forecast near 10"
along the Iowa Missouri border, certainly warrants a watch. While
this will leave little lead time when the watch is changed to an
advisory and/or warning with precipitation commencing in our
southwest area, it will allow for a further tightening of the
gradient and fine tuning of the location of the expected highest
snow totals.

As the snow ends early Friday, the pattern will take on a more
spring-like pattern with rising heights as high pressure passes
south of the region Friday into Saturday. While another cold front
will pass through on Sunday, it is primarily moisture-starved with
only perhaps a slight impact on temperatures on Sunday across the
north. Temperatures will be fairly close to typical for mid-April
for the weekend into early next week. The next chance for showers or
even some thunderstorms will arrive on Tuesday with the highest
chances over southern Iowa.

&&

.AVIATION.../For the 00Z TAFS through 00Z Thursday evening/
Issued at 627 PM CDT Wed Apr 15 2020

Quiet weather for the rest of this evening. Cumulus clouds with
VFR bases will dissipate. Low pressure will track across central
Missouri tomorrow, and will bring heavy snowfall to southern Iowa.
The main terminal impacts will to OTM, which will see visibility
less than 2 miles at times if the one inch per hour snowfall rates
are fully realized. DSM is the most uncertain TAF, as a sharp
cutoff in dry air will be present near the Des Moines metro. For
now, will leave the mention of snow and slightly reduced
visibilityin the TAF. If the banding snow shifts northward, the
impacts could be greater, but a shift few miles further south
could potentially leave DSM mostly dry. The precipitation will
stay well south of FOD, ALO, and MCW.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from 5 AM CDT Thursday through Friday morning
for IAZ070>075-081>086-092>097.

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DISCUSSION...Ansorge
AVIATION...Krull

Hazardous Weather Outlook
National Weather Service Des Moines IA
351 PM CDT Wed Apr 15 2020

IAZ070>075-081>086-092>097-162100-
Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-Clarke-Lucas-
Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-Appanoose-Davis-
351 PM CDT Wed Apr 15 2020

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

A Winter Storm Watch is in effect for the area early Thursday
through Thursday Night. Please refer to the National Weather
Service website at weather.gov/desmoines for further details.

A few thunderstorms are possible central and south Tuesday. Severe
weather is unlikely at this time.

.SPOTTER INFORMATION STATEMENT...

Spotters will not be needed, but snowfall reports are appreciated.

IAZ057>062-162100-
Audubon-Guthrie-Dallas-Polk-Jasper-Poweshiek-
351 PM CDT Wed Apr 15 2020

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Light snow, perhaps mixing with rain at times, is likely Thursday
into Thursday night over the I-80 and Highway 30 counties with
some minor accumulations possible.

A few thunderstorms are possible central and south Tuesday. Severe
weather is unlikely at this time.

.SPOTTER INFORMATION STATEMENT...

Spotters will not be needed, but snowfall reports are appreciated.

IAZ004>007-015>017-023>028-033>039-044>050-162100-
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-
351 PM CDT Wed Apr 15 2020

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter will not be needed.

Ansorge