Flash Flood Warning 29, NWS Sioux Falls, SD

501 
WGUS73 KFSD 251010
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
510 AM CDT WED JUL 25 2018

SDC015-023-053-251145-
/O.CON.KFSD.FF.W.0029.000000T0000Z-180725T1145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Charles Mix SD-Gregory SD-Brule SD-
510 AM CDT WED JUL 25 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 AM CDT FOR
NORTHWESTERN CHARLES MIX...NORTHWESTERN GREGORY AND SOUTHWESTERN
BRULE COUNTIES...

At 509 AM CDT, Doppler radar indicated thunderstorms had produced 
heavy rainfall across the warning area.  Since midnight, radar 
estimates indicate 2 to 5" of rain has fallen.  Flash flooding is 
likely ongoing or beginning to slowly subside. 

Flash flooding will remain over mainly rural areas of northwestern
Charles Mix...northwestern Gregory and southwestern Brule Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4350 9935 4350 9929 4353 9928 4357 9934
      4359 9934 4360 9922 4335 9910 4328 9901
      4320 9914 4323 9929 4331 9936

$$

Dux

921 
WGUS73 KFSD 251136
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
636 AM CDT WED JUL 25 2018

SDC015-023-053-251146-
/O.EXP.KFSD.FF.W.0029.000000T0000Z-180725T1145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Charles Mix SD-Gregory SD-Brule SD-
636 AM CDT WED JUL 25 2018

...THE FLASH FLOOD WARNING FOR NORTHWESTERN CHARLES MIX...
NORTHWESTERN GREGORY AND SOUTHWESTERN BRULE COUNTIES WILL EXPIRE AT
645 AM CDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 4350 9935 4350 9929 4353 9928 4357 9934
      4359 9934 4360 9922 4335 9910 4328 9901
      4320 9914 4323 9929 4331 9936

$$

Dux

Area Forecast Discussion
National Weather Service Sioux Falls SD
1049 PM CDT Tue Jul 24 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 313 PM CDT Tue Jul 24 2018

The focus for this forecast will be thunderstorm chances tonight
into Wednesday evening, then cooler temperatures to finish the week.
Surface high pressure was moving through the area today allowing for
a beautiful late afternoon and evening. The approach of a weak upper
level wave will turn winds in the low to mid levels to the south and
southwest and advect a bit more moist and unstable air northward.
This should allow thunderstorms to develop over the Western High
Plains this evening and move east and southeast through the night.
Thunderstorm chances across southeast SD into southwest MN may be at
a bit of a minimum as the higher lapse rates might drive a complex
to the south into Nebraska and the stronger dynamic forcing and
synoptic scale boundary are across northern SD into west central MN.
If thunderstorms can advect into the area a few of them may be
severe with strong winds the main threat. Instability very marginal
but a deep dry layer may allow for an enhanced wind gust threat. The
soundings do seem to support the potential for a weak heat burst,
maybe temperatures bumping up into the mid 80s, with the inversion
about 1500 feet deep and very dry above and below.

Wednesday a messy forecast as any overnight activity, or lack
thereof, will aid in determining what happens Wednesday afternoon
and evening. For now believe that there will be some activity around
on Wednesday morning, but then expect a lull from late morning into
early afternoon. The cool front will work into the south part of the
area by mid afternoon Wednesday. Soundings indicate CAPE profiles of
about 1500-2000 J/kg with with decent mid and upper level
unidirectional shear. If any storms could develop Wednesday
afternoon they would pose a threat for hail up to golf balls and
winds to 60 mph, especially if storms can split and a left dominate
cell can develop. Something to watch for but right now confidence is
marginal.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 313 PM CDT Tue Jul 24 2018

Strong upper level low pressure over the Great Lakes will keep
cooler than normal temperatures in place through the weekend with
strong northwest flow aloft across the Northern and Central Plains.
Thursday and Friday look dry and cooler with highs in the 70s and
morning lows in the 50s. Friday night into Saturday a wave will move
through the flow to the south and bring a chance for rain ans
thunderstorms, with the better chances likely south of Interstate 90.
At this time not looking like a severe weather threat. As this wave
passes the cooler air mostly remains in place but does modify a bit
with some westerly flow possible. Highs Monday and Tuesday should be
about 75 to 85 with dry conditions.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1044 PM CDT Tue Jul 24 2018

VFR is expected to be the dominant category for the 06Z TAF set at
KHON, KFSD and KSUX. However there will be chances for showers and
thunderstorms as an upper air disturbance moves through the area
from northwest to southeast with an associated cold front. For
now, have a TSRA tempo group for KHON and KFSD for very late
tonight and Wednesday morning following the timing of the TSRA
which currently resides from western SD to southwest ND along the
disturbance. The chances of this early day convection happening at
KSUX is more skittish. In the afternoon, there will be more
chances for TSRA at KFSD and KSUX as the cold front moves through.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

SHORT TERM...08
LONG TERM...08
AVIATION...MJ

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
414 PM CDT Tue Jul 24 2018

IAZ001>003-012>014-020>022-031-032-MNZ089-090-NEZ013-014-SDZ067-
070-071-252115-
Lyon IA-Osceola-Dickinson-Sioux-O'Brien-Clay IA-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Nobles-Jackson-Dixon-Dakota-Lincoln SD-
Clay SD-Union-
414 PM CDT Tue Jul 24 2018

This Hazardous Weather Outlook is for portions of northwest Iowa,
west central Iowa, southwest Minnesota, northeast Nebraska, and
southeast South Dakota.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

There is a slight risk of severe thunderstorms on Wednesday.
However the instability is contingent on how much rain develops
in the morning and early afternoon. If conditions remain cloudy
through the first half of the day, severe storms will be very
limited. If sky conditions can break out and allow the atmosphere
to destabilize, then golf ball size hail and wind gusts around 60
mph are possible. The primary time frame for severe weather
chances will be 4 pm to 9 pm.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed tonight.

MNZ071-072-080-081-097-098-SDZ056-061-062-065-066-068-069-252115-
Lincoln MN-Lyon MN-Murray-Cottonwood-Pipestone-Rock-Moody-McCook-
Minnehaha-Hutchinson-Turner-Bon Homme-Yankton-
414 PM CDT Tue Jul 24 2018

This Hazardous Weather Outlook is for portions of southwest
Minnesota, east central South Dakota, and southeast South Dakota.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Thunderstorms chances will continue during the day on Wednesday as
a cold front moves through. A few storms may be marginally severe
in the vicinity of the cold front.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed tonight.

SDZ038>040-050-052>055-057>060-063-064-252115-
Beadle-Kingsbury-Brookings-Gregory-Jerauld-Sanborn-Miner-Lake-
Brule-Aurora-Davison-Hanson-Charles Mix-Douglas-
414 PM CDT Tue Jul 24 2018

This Hazardous Weather Outlook is for portions of central South
Dakota, east central South Dakota, south central South Dakota,
and southeast South Dakota.

.DAY ONE...Tonight

A few thunderstorms late tonight could produce isolated wind gusts
to 60 mph.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Thunderstorms chances will continue on Wednesday morning with gusty
winds in the vicinity of storms the primary threat.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed tonight.