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Flood Watch


Flood Watch
National Weather Service Riverton WY
916 AM MDT Tue May 22 2018

...Rapid rises along mountain streams and creeks expected tonight
through early Wednesday morning...

.Three quarters to one inch of rain is expected across the
upper Wind River Basin and Absaroka Mountains tonight through
early Wednesday morning; while one inch to an inch and a half
inch of rain is forecasted across the Big Horn Mountains tonight
through early Wednesday morning. Locally higher amounts of
precipitation is possible with thunderstorms. Rapid rises of
streams and creeks will cause flooding of low lying areas tonight
through Wednesday morning.


WYZ002-004-006-008-009-015-016-231530-
/O.NEW.KRIW.FA.A.0003.180523T0000Z-180523T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Absaroka Mountains-North Big Horn Basin-Southeast Big Horn Basin-
Bighorn Mountains West-Bighorn Mountains Southeast-
Wind River Mountains East-Upper Wind River Basin-
Including the cities of Worland and Dubois
916 AM MDT Tue May 22 2018

...FLOOD WATCH IN EFFECT FROM 6 PM MDT THIS EVENING THROUGH
WEDNESDAY MORNING...

The National Weather Service in Riverton has issued a

* Flood Watch for portions of central Wyoming, north central
  Wyoming, and northwest Wyoming, including the following areas,
  in central Wyoming, Upper Wind River Basin and Wind River
  Mountains East. In north central Wyoming, Bighorn Mountains
  Southeast, Bighorn Mountains West, and Southeast Big Horn
  Basin. In northwest Wyoming, Absaroka Mountains and North Big
  Horn Basin.

* From 6 PM MDT this evening through Wednesday morning

* Three quarters to one inch of rain is expected across the upper
  Wind River Basin and Absaroka Mountains tonight through early
  Wednesday morning; while one inch to an inch and a half inch of
  rain is forecasted across the Big Horn Mountains tonight through
  early Wednesday morning. Locally higher amounts of
  precipitation is possible with thunderstorms.

* Rapid rises of streams and creeks will cause flooding of low
  lying areas tonight through Wednesday morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Watch means there is a potential for flooding based on
current forecasts.

You should monitor later forecasts and be alert for possible
Flood Warnings. Those living in areas prone to flooding should be
prepared to take action should flooding develop. Crossing creeks
and streams will be very hazardous tonight through early
Wednesday morning.

&&

$$
jtfahey


Hazardous Weather Outlook


Hazardous Weather Outlook
National Weather Service Grand Junction CO
241 AM MDT Wed May 23 2018

COZ001>014-017>023-UTZ022>025-027>029-241200-
Lower Yampa River Basin-Central Yampa River Basin-
Roan and Tavaputs Plateaus-Elkhead and Park Mountains-
Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor-
Central Colorado River Basin-Grand and Battlement Mesas-
Gore and Elk Mountains/Central Mountain Valleys-
Central Gunnison and Uncompahgre River Basin-
West Elk and Sawatch Mountains-Flat Tops-
Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide-
Northwest San Juan Mountains-Southwest San Juan Mountains-
Paradox Valley/Lower Dolores River-
Four Corners/Upper Dolores River-Animas River Basin-
San Juan River Basin-Southeast Utah-Eastern Uinta Mountains-
Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat-
La Sal and Abajo Mountains-Canyonlands/Natural Bridges-
241 AM MDT Wed May 23 2018

This hazardous weather outlook is for eastern Utah and western
Colorado.

.DAY ONE...Today and Tonight

Scattered thunderstorms will develop this afternoon and continue
through early evening across northeast Utah and northwest
Colorado, mainly areas north of I-70. Storms will favor higher
terrain with gusty outflow winds and lightning the primary
concerns. Elsewhere, partly to mostly sunny skies can be expected
with warmer temperatures than yesterday.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Dry conditions with warm, above normal temperatures will continue
through the weekend. Winds will increase on Saturday ahead of an
approaching storm system, leading to potential for critical fire
weather conditions. The chance for precipitation will slowly
increase late weekend into early next week as this storm system
affects the area, with isolated to scattered storms favoring
higher terrain at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

$$

Hazardous Weather Outlook
National Weather Service Riverton WY
229 AM MDT Wed May 23 2018

WYZ001>020-022>030-241100-
Yellowstone National Park-Absaroka Mountains-Cody Foothills-
North Big Horn Basin-Southwest Big Horn Basin-
Southeast Big Horn Basin-Owl Creek and Bridger Mountains-
Bighorn Mountains West-Bighorn Mountains Southeast-
Northeast Johnson County-Southeast Johnson County-
Teton and Gros Ventre Mountains-Jackson Hole-
Wind River Mountains West-Wind River Mountains East-
Upper Wind River Basin-Wind River Basin-Lander Foothills-
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-Casper Mountain-Star Valley-
Salt River and Wyoming Ranges-Upper Green River Basin Foothills-
Upper Green River Basin-South Lincoln County-
Rock Springs and Green River-Flaming Gorge-East Sweetwater County-
229 AM MDT Wed May 23 2018

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and Tonight

Isolated afternoon and evening thunderstorms; most numerous in
northern and western Wyoming. Localized flooding possible.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Thursday...A chance of afternoon and evening thunderstorms over
and near the mountains.

Saturday...Isolated afternoon and evening thunderstorms in the
west.

Sunday and Memorial Day...Scattered mainly afternoon and evening
thunderstorms most areas. Isolated strong to severe thunderstorms
possible on Sunday across central Wyoming.

.SPOTTER INFORMATION STATEMENT...

Spotters are urged to report hail, wind gusts past 45 mph and any
flooding. Thank you.

$$

Hazardous Weather Outlook
National Weather Service North Platte NE
312 AM CDT Wed May 23 2018

NEZ004>010-022>029-035>038-056>059-069>071-094-240815-
Sheridan-Eastern Cherry-Keya Paha-Boyd-Brown-Rock-Holt-Garden-
Grant-Hooker-Thomas-Blaine-Loup-Garfield-Wheeler-Arthur-McPherson-
Logan-Custer-Deuel-Keith-Perkins-Lincoln-Chase-Hayes-Frontier-
Western Cherry-
312 AM CDT Wed May 23 2018 /212 AM MDT Wed May 23 2018/

This Hazardous Weather Outlook is for portions of western and
north central Nebraska.

.DAY ONE...TODAY AND TONIGHT.

Scattered thunderstorms will affect western Nebraska this
afternoon and evening and north central Nebraska tonight. Some
storms will be capable of producing large hail and strong winds,
primarily for portions of the northern panhandle and northwest
Nebraska.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

Another round of thunderstorms is possible Thursday afternoon and
evening, mainly along and east of Highway 83. A few storms may
approach severe limits with hail and wind the primary threats.

Thunderstorm chances increase again Sunday and Monday evenings.
The severe threat is uncertain at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated through tonight.

&&

Get your weather, hydrological, and climate information at
http://www.weather.gov/northplatte

$$

DS

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1103 AM MDT Tue May 22 2018

COZ030>051-231715-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1103 AM MDT Tue May 22 2018

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Scattered showers and thunderstorms will develop over the
mountains and foothills this afternoon and evening with brief
heavy rain, gusty winds and small hail. A few thunderstorms will also
move off the foothills and over the urban corridor and northern
plains late in the afternoon and early evening. There is a slight
chance that the storms which develop near the Wyoming border
could produce hail up to one inch in diameter. Thunderstorm
activity is expected to come to an end by 10 PM.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

A few afternoon and evening thunderstorms can be expected again on
Wednesday. A couple of the storms on the eastern plains may be
severe near the Wyoming and Nebraska borders with large hail and
gusty winds being the main threats. There should be less storm
coverage Thursday into Saturday, although there is still a risk of
a severe storm or two near the Nebraska border on Thursday.

An approaching storm system will bring the threat of thunderstorms
and possible severe weather back to the Front Range I-25 Corridor
late this weekend into early next week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

$$

Hazardous Weather Outlook
National Weather Service Cheyenne WY
1000 AM MDT Tue May 22 2018

NEZ002-003-019>021-054-055-095-096-231030-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-
1000 AM MDT Tue May 22 2018

This hazardous weather outlook is for portions of western
Nebraska.

.DAY ONE...REST OF TODAY AND TONIGHT

Scattered showers and thunderstorms are expected this afternoon and
evening. A few storms could become strong with gusty winds and small
hail.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Scattered showers and thunderstorms are expected Wednesday, and
again Sunday and Monday. A few strong to severe storms are
possible Wednesday afternoon with hail the main threat.

.Spotter information statement...

Spotter activation is not expected.

$$

Hazardous Weather Outlook
National Weather Service Cheyenne WY
1000 AM MDT Tue May 22 2018

WYZ101>119-231030-
Converse County Lower Elevations-Niobrara County-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-Central Carbon County-
North Snowy Range Foothills-Southwest Carbon County-
Sierra Madre Range-Upper North Platte River Basin-Snowy Range-
Laramie Valley-South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
1000 AM MDT Tue May 22 2018

This hazardous weather outlook is for portions of east central
Wyoming...south central Wyoming and southeast Wyoming.

.DAY ONE...REST OF TODAY AND TONIGHT

Scattered to numerous showers and thunderstorms are expected this
afternoon and evening. A few storms could become strong to severe
with hail the main threat.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Scattered showers and thunderstorms are expected Wednesday, and
again Sunday and Monday. A few storms could become strong to severe
in the Wyoming High Plains east of the Laramie Range.

.Spotter information statement...

Spotter activation is not anticipated.

$$

Hazardous Weather Outlook
National Weather Service Rapid City SD
558 AM MDT Tue May 22 2018

SDZ001-002-012>014-024>031-041-042-072>074-WYZ054>058-071-231300-
Harding-Perkins-Butte-Northern Meade Co Plains-Ziebach-
Northern Black Hills-Northern Foot Hills-Rapid City-
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Pennington Co Plains-Fall River-Oglala Lakota-
Sturgis/Piedmont Foot Hills-Southern Meade Co Plains-
Hermosa Foot Hills-Northern Campbell-Southern Campbell-
Western Crook-Wyoming Black Hills-Weston-Northeastern Crook-
558 AM MDT Tue May 22 2018

This Hazardous Weather Outlook is for portions of northwestern
South Dakota...southwestern South Dakota...the Black Hills of
South Dakota...northeast Wyoming...and the Black Hills of
Wyoming.

.DAY ONE...Today and Tonight

Showers and thunderstorms will develop this afternoon and persist
into the overnight hours. A few strong to severe storms will be
possible, along with the possibility of heavy rainfall.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Chances for thunderstorms are expected for the remainder of the
week. The best chances for storms will be on Wednesday, with
strong to severe storms possible again.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

$$


Hydrologic Outlook


Hydrologic Outlook
WYC003-013-023-029-039-240406-
Hydrologic Outlook
National Weather Service Riverton WY
1006 AM MDT Tue May 22 2018

...Accelerated snowmelt at the 9,000 to 10,000 foot elevation
Friday through Sunday...

...Significant rises in creeks and streams during the
Memorial Day Weekend...

The snowpack at the 9,000 to 10,000 foot elevation has ripened
considerably in the last week to 10 days due to mild temperatures
and recent rainfall.  Rainfall today and Wednesday will only
further ripen or increase the water content of the current snowpack.

Afternoon mountain temperatures at the 9,000 foot elevation are
expected to warm to near 60 for Thursday--and into the lower to
middle 60s Friday through Sunday.  Morning low temperatures are
forecasted to be at or above the frost temperature of 37 degrees
Thursday through Sunday.

Increased snowmelt at the 9,000 to 10,000 foot elevation Friday
through Sunday will cause significant rises in creeks and streams
during the Memorial Day Weekend.

Rain showers are in the forecast for Sunday afternoon through and Memorial
Day. The combination of rain and snowmelt runoff will greatly increase
river levels.

The Wind River and the South Fork of the Shoshone River should see flows
high enough to cause flooding by Monday and Tuesday of next week.
Tributary streams that feed into the Big Horn and Snake Rivers may
see the highest flows of the season early next week.

During active snowmelt runoff, mountain creeks and streams are
at their highest levels during the late afternoon/early evening
hours.  Crossing creeks and streams during that time is highly
hazardous.

Graphical forecasts are available at:
http://water.weather.gov/ahps2/index.php?wfo=riw
Visit weather.gov/riverton and select the rivers & lakes tab for
graphical forecasts and additional information.

$$
jtfahey

U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: June 2, 2009
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