Alert archive / Wyoming / High Wind Warnings in 2009

High Wind Warning 8, NWS Riverton, WY

September 20, 2009Big Horn County, Johnson County, Park County, Wyoming

NWS Riverton, WY issued this high wind warning at Sep 20, 2009, 2:39 PM MDT for Big Horn County, Johnson County, Park County, Wyoming. It took effect at Sep 20, 2009, 6:00 PM MDT. It was in force for 9 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 20, 2009, 2:39 PM MDT (20:39 UTC)
In effect from
Sep 20, 2009, 6:00 PM MDT
Expired
Sep 21, 2009, 2:57 AM MDT
In force
9 hr
Issued by
NWS Riverton, WY

Counties Big Horn County, WY, Johnson County, WY, Park County, WY

The radar

The Riverton/Lander radar (KRIW), 148 km from the middle of the area, began a volume at 20:39 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 8.7 hours before the alert went out and 146 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Riverton, WY at 12:00Z on 2009-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2009-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
6 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
2743 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS75 KRIW 202039
NPWRIW

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE RIVERTON WY
239 PM MDT SUN SEP 20 2009

...HIGH WIND WARNING FOR NORTHERN BIGHORN BASIN AND NORTHEAST
JOHNSON COUNTY TONIGHT...

...FREEZE WARNING FOR THE UPPER WIND RIVER BASIN TONIGHT...

.A STRONG STORM SYSTEM WILL MOVE ACROSS THE COWBOY STATE
TONIGHT...BRINGING MUCH COOLER...VERY WINDY CONDITIONS...AND SOME
RAIN AND SNOW. A STRONG COLD FRONT WILL QUICKLY PUSH SOUTH ACROSS
THE AREA TONIGHT...WITH STRONG NORTHWEST TO NORTHEAST WINDS
EXPECTED BEHIND THE FRONT. THE STRONGEST WINDS WILL BE OVER NORTHERN
BIGHORN BASIN AND THE LOWER ELEVATIONS OF NORTHERN JOHNSON...WHERE
SUSTAINED WINDS ARE EXPECTED TO REACH BETWEEN 30 AND 45 MPH...WITH
A FEW GUSTS AROUND 55 MPH. THE UPPER WIND RIVER BASIN IS EXPECTED TO
REACH FREEZING TONIGHT BEHIND THE COLD FRONT. MORE WIDESPREAD
FREEZING TEMPERATURES COULD OCCUR OVER THE LOWER ELEVATIONS MONDAY
NIGHT...AS WINDS DECREASE AND THE SKY BECOMES MOSTLY CLEAR. 

WYZ016-211200-
/O.NEW.KRIW.FZ.W.0003.090921T0600Z-090921T1500Z/
UPPER WIND RIVER BASIN-
INCLUDING THE CITY OF...DUBOIS
239 PM MDT SUN SEP 20 2009

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM MDT
MONDAY...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A FREEZE
WARNING...WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM MDT
MONDAY. 

A STRONG COLD FRONT WILL USHER IN MUCH COLDER AIR INTO THE UPPER
WIND RIVER BASIN...WITH SUB FREEZING TEMPERATURES EXPECTED.
ALTHOUGH A FEW AREAS HAVE REACHED FREEZING ALREADY...WIDESPREAD
FREEZING TEMPERATURES ARE EXPECTED FROM CROWHEART TO DUBOIS TONIGHT.
LOW TEMPERATURES TONIGHT ARE EXPECTED TO RANGE FROM THE LOWER 30S
NEAR CROWHEART...TO THE MID AND UPPER 20S NEAR DUBOIS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL SENSITIVE PLANTS OR
GARDENS.

&&

$$

WYZ004-211200-
/O.NEW.KRIW.HW.W.0008.090921T0000Z-090921T1200Z/
NORTH BIG HORN BASIN-
INCLUDING THE CITIES OF...POWELL...LOVELL...GREYBULL...BASIN
239 PM MDT SUN SEP 20 2009

...HIGH WIND WARNING IN EFFECT FROM 6 PM THIS EVENING TO 6 AM MDT
MONDAY...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 6 PM THIS EVENING TO 6 AM MDT
MONDAY. 

VERY STRONG NORTHWEST WINDS ARE EXPECTED TO DEVELOP OVER THE
NORTHERN BIG HORN BASIN BEHIND A STRONG COLD FRONT THIS EVENING.
NORTHWEST WINDS BETWEEN 30 AND 45 MPH ARE EXPECTED WITH A FEW
GUSTS NEAR 55 MPH. WINDS ARE EXPECTED TO GRADUALLY DECREASE AFTER
MIDNIGHT...BUT STILL REMAIN STRONG. RESIDENTS ARE URGED TO SECURE
OR BRING INDOORS ANY LOOSE ITEMS. IN ADDITION...TRAVELERS DRIVING
ACROSS THE BIGHORN MOUNTAINS TONIGHT CAN EXPECT TO ENCOUNTER SOME
SNOW WITH REDUCED VISIBILITY...WITH GRANITE AND POWDER RIVER
PASSES POTENTIALLY BECOMING SLICK IN SPOTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WARNING MEANS A HAZARDOUS HIGH WIND EVENT IS EXPECTED
OR OCCURRING. SUSTAINED WIND SPEEDS OF AT LEAST 40 MPH OR GUSTS
OF 58 MPH OR MORE CAN LEAD TO PROPERTY DAMAGE.

&&

$$

WYZ010-211200-
/O.NEW.KRIW.HW.W.0008.090921T0000Z-090921T1200Z/
NORTHEAST JOHNSON COUNTY-
INCLUDING THE CITY OF...BUFFALO
239 PM MDT SUN SEP 20 2009

...HIGH WIND WARNING IN EFFECT FROM 6 PM THIS EVENING TO 6 AM MDT
MONDAY...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT FROM 6 PM THIS EVENING TO 6 AM MDT
MONDAY. 

VERY STRONG NORTHWEST WINDS ARE EXPECTED TO DEVELOP OVER THE LOWER
ELEVATIONS OF NORTHERN JOHNSON COUNTY BEHIND A STRONG COLD FRONT
THIS EVENING. NORTHWEST WINDS BETWEEN 30 AND 45 MPH ARE EXPECTED
WITH A FEW GUSTS NEAR 55 MPH. WINDS ARE EXPECTED TO GRADUALLY
DECREASE AFTER MIDNIGHT...BUT STILL REMAIN STRONG. RESIDENTS ARE
URGED TO SECURE OR BRING INDOORS ANY LOOSE ITEMS. IN ADDITION...TRAVELERS
DRIVING ACROSS THE BIGHORN MOUNTAINS TONIGHT CAN EXPECT TO
ENCOUNTER SOME SNOW WITH REDUCED VISIBILITY...WITH GRANITE AND
POWDER RIVER PASSES POTENTIALLY BECOMING SLICK IN SPOTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WARNING MEANS A HAZARDOUS HIGH WIND EVENT IS EXPECTED
OR OCCURRING. SUSTAINED WIND SPEEDS OF AT LEAST 40 MPH OR GUSTS
OF 58 MPH OR MORE CAN LEAD TO PROPERTY DAMAGE.

&&

$$

21
2 follow-up statements
000 
WWUS75 KRIW 210340
NPWRIW

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE RIVERTON WY
940 PM MDT SUN SEP 20 2009

...HIGH WIND WARNING FOR NORTHERN BIGHORN BASIN AND NORTHEAST
JOHNSON COUNTY TONIGHT...

...FREEZE WARNING FOR THE UPPER WIND RIVER BASIN TONIGHT...

...FREEZE WATCH FOR THE LOWER ELEVATIONS OF CENTRAL WYOMING 
EARLY TUESDAY MORNING...

.A STRONG STORM SYSTEM WILL MOVE ACROSS THE COWBOY STATE
TONIGHT...BRINGING MUCH COOLER...VERY WINDY CONDITIONS...AND SOME
RAIN AND SNOW. A STRONG COLD FRONT WILL QUICKLY PUSH SOUTH ACROSS
THE AREA TONIGHT...WITH STRONG NORTHWEST TO NORTHEAST WINDS
EXPECTED BEHIND THE FRONT. THE STRONGEST WINDS WILL BE OVER
NORTHERN BIGHORN BASIN AND THE LOWER ELEVATIONS OF NORTHERN
JOHNSON...WHERE SUSTAINED WINDS ARE EXPECTED TO REACH BETWEEN
30 AND 45 MPH...WITH A FEW GUSTS AROUND 55 MPH. THE UPPER WIND
RIVER BASIN IS EXPECTED TO REACH FREEZING TONIGHT BEHIND THE COLD
FRONT. MORE WIDESPREAD FREEZING TEMPERATURES COULD OCCUR OVER THE
LOWER ELEVATIONS MONDAY NIGHT...AS WINDS DECREASE AND THE SKY
BECOMES MOSTLY CLEAR.

WYZ004-211145-
/O.NEW.KRIW.FZ.A.0002.090922T0600Z-090922T1500Z/
/O.CON.KRIW.HW.W.0008.000000T0000Z-090921T1200Z/
NORTH BIG HORN BASIN-
INCLUDING THE CITIES OF...POWELL...LOVELL...GREYBULL...BASIN
940 PM MDT SUN SEP 20 2009

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 6 AM MDT MONDAY...
...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A FREEZE
WATCH...WHICH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING. A HIGH WIND WARNING REMAINS IN EFFECT UNTIL 6 AM MDT
MONDAY. 

STRONG NORTHWEST WINDS WILL CONTINUE OVERNIGHT. SUSTAINED WINDS
OF 30 TO 40 MPH WITH GUSTS OF 50 TO 55 MPH CONTINUED ACROSS THE
AREA THIS EVENING. THESE STRONG WINDS ARE EXPECTED TO CONTINUE FOR
THE REMAINDER OF THE EVENING. WINDS ARE EXPECTED TO GRADUALLY
DECREASE AFTER MIDNIGHT. RESIDENTS ARE URGED TO SECURE OR BRING
INDOORS ANY LOOSE ITEMS. IN ADDITION...TRAVELERS DRIVING ACROSS
THE BIGHORN MOUNTAINS TONIGHT CAN EXPECT TO ENCOUNTER SOME SNOW
WITH REDUCED VISIBILITY...WITH GRANITE AND POWDER RIVER PASSES
POTENTIALLY BECOMING SLICK IN SPOTS.

CLEARING SKIES AND A COLD DRY AIRMASS WILL RESULT IN TEMPERATURES
FALLING TO NEAR OR BELOW FREEZING MONDAY NIGHT AND EARLY TUESDAY
MORNING. THE COLDEST TEMPERATURES ARE EXPECTED ALONG THE LOWER
RIVER VALLEYS. PEOPLE SHOULD TAKE PRECAUTIONS TO PROTECT VEGETABLE
CROPS AND OTHER COLD-SENSITIVE PLANTS FROM THE POSSIBILITY OF A
HARD FROST OR FREEZE EARLY TUESDAY MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WARNING MEANS A HAZARDOUS HIGH WIND EVENT IS EXPECTED
OR OCCURRING. SUSTAINED WIND SPEEDS OF AT LEAST 40 MPH OR GUSTS
OF 58 MPH OR MORE CAN LEAD TO PROPERTY DAMAGE.

A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.

&&

$$

WYZ010-211145-
/O.NEW.KRIW.FZ.A.0002.090922T0600Z-090922T1500Z/
/O.CON.KRIW.HW.W.0008.000000T0000Z-090921T1200Z/
NORTHEAST JOHNSON COUNTY-
INCLUDING THE CITY OF...BUFFALO
940 PM MDT SUN SEP 20 2009

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 6 AM MDT MONDAY...
...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A FREEZE
WATCH...WHICH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING. A HIGH WIND WARNING REMAINS IN EFFECT UNTIL 6 AM MDT
MONDAY. 

STRONG NORTHWEST WINDS AT 35 TO 45 MPH CONTINUED ACROSS NORTHEAST
JOHNSON COUNTY THIS EVENING. THESE WINDS ARE EXPECTED TO CONTINUE
THROUGH THE REST OF THE EVENING BEFORE GRADUALLY DECREASING AFTER
MIDNIGHT.  RESIDENTS ARE URGED TO SECURE OR BRING INDOORS ANY
LOOSE ITEMS. IN ADDITION...TRAVELERS DRIVING ACROSS THE BIGHORN
MOUNTAINS TONIGHT CAN EXPECT TO ENCOUNTER SOME SNOW WITH REDUCED
VISIBILITY...WITH GRANITE AND POWDER RIVER PASSES POTENTIALLY
BECOMING SLICK IN SPOTS.

CLEARING SKIES AND A COLD DRY AIRMASS WILL RESULT IN TEMPERATURES
FALLING TO NEAR OR BELOW FREEZING MONDAY NIGHT AND EARLY TUESDAY
MORNING. THE COLDEST TEMPERATURES ARE EXPECTED ALONG THE LOWER
RIVER VALLEYS. PEOPLE SHOULD TAKE PRECAUTIONS TO PROTECT VEGETABLE
CROPS AND OTHER COLD-SENSITIVE PLANTS FROM THE POSSIBILITY OF A
HARD FROST OR FREEZE EARLY TUESDAY MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WARNING MEANS A HAZARDOUS HIGH WIND EVENT IS EXPECTED
OR OCCURRING. SUSTAINED WIND SPEEDS OF AT LEAST 40 MPH OR GUSTS
OF 58 MPH OR MORE CAN LEAD TO PROPERTY DAMAGE.

A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.

&&

$$

WYZ016-211145-
/O.CON.KRIW.FZ.W.0003.090921T0600Z-090921T1500Z/
UPPER WIND RIVER BASIN-
INCLUDING THE CITY OF...DUBOIS
940 PM MDT SUN SEP 20 2009

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM MDT MONDAY...

A FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM MDT MONDAY. 

A STRONG COLD FRONT WILL USHER IN MUCH COLDER AIR INTO THE UPPER
WIND RIVER BASIN...WITH SUB FREEZING TEMPERATURES EXPECTED.
ALTHOUGH A FEW AREAS HAVE REACHED FREEZING ALREADY...WIDESPREAD
FREEZING TEMPERATURES ARE EXPECTED FROM CROWHEART TO DUBOIS
TONIGHT. LOW TEMPERATURES TONIGHT ARE EXPECTED TO RANGE FROM THE
LOWER 30S NEAR CROWHEART...TO THE MID AND UPPER 20S NEAR DUBOIS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL SENSITIVE PLANTS OR
GARDENS.

&&

$$

WYZ003-005-006-011-017>020-028>030-211145-
/O.NEW.KRIW.FZ.A.0002.090922T0600Z-090922T1500Z/
CODY FOOTHILLS-SOUTHWEST BIG HORN BASIN-SOUTHEAST BIG HORN BASIN-
SOUTHEAST JOHNSON COUNTY-WIND RIVER BASIN-LANDER FOOTHILLS-
GREEN MOUNTAINS AND RATTLESNAKE RANGE-
NATRONA COUNTY LOWER ELEVATIONS-ROCK SPRINGS AND GREEN RIVER-
FLAMING GORGE-EAST SWEETWATER COUNTY-
INCLUDING THE CITIES OF...CODY...MEETEETSE...THERMOPOLIS...
WORLAND...KAYCEE...RIVERTON...SHOSHONI...LANDER...JEFFREY CITY...
CASPER...ROCK SPRINGS...GREEN RIVER...WAMSUTTER
940 PM MDT SUN SEP 20 2009

...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A FREEZE
WATCH...WHICH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY
MORNING. 

CLEARING SKIES AND A COLD DRY AIRMASS WILL RESULT IN TEMPERATURES
FALLING TO NEAR OR BELOW FREEZING MONDAY NIGHT AND EARLY TUESDAY
MORNING. THE COLDEST TEMPERATURES ARE EXPECTED ALONG THE LOWER
RIVER VALLEYS. PEOPLE SHOULD TAKE PRECAUTIONS TO PROTECT VEGETABLE
CROPS AND OTHER COLD-SENSITIVE PLANTS FROM THE POSSIBILITY OF A
HARD FROST OR FREEZE EARLY TUESDAY MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.

&&

$$

MEUNIER
000 
WWUS75 KRIW 210857
NPWRIW

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE RIVERTON WY
257 AM MDT MON SEP 21 2009

...HIGH WIND WARNING FOR NORTHERN BIGHORN BASIN AND NORTHEAST
JOHNSON COUNTY TONIGHT...

...FREEZE WARNING FOR THE UPPER WIND RIVER BASIN TONIGHT...

...FREEZE WATCH FOR THE LOWER ELEVATIONS OF CENTRAL WYOMING EARLY
TUESDAY MORNING...

.A STRONG STORM SYSTEM WILL MOVE ACROSS EASTERN WYOMING 
TODAY...BRINGING MUCH COOLER...VERY WINDY CONDITIONS...AND SOME
RAIN AND SNOW. THE UPPER WIND RIVER BASIN IS EXPECTED TO REACH
FREEZING EARLY THIS MORNING THROUGH AROUND DAWN BEHIND A COLD
FRONT. MORE WIDESPREAD FREEZING TEMPERATURES COULD OCCUR OVER THE
LOWER ELEVATIONS OF CENTRAL WYOMING AND SWEETWATER COUNTY LATE MONDAY
NIGHT AND TUESDAY MORNING...AS WINDS DECREASE AND THE SKY BECOMES MOSTLY
CLEAR.

WYZ004-010-212200-
/O.CAN.KRIW.HW.W.0008.000000T0000Z-090921T1200Z/
/O.CON.KRIW.FZ.A.0002.090922T0600Z-090922T1500Z/
NORTH BIG HORN BASIN-NORTHEAST JOHNSON COUNTY-
INCLUDING THE CITIES OF...POWELL...LOVELL...GREYBULL...BASIN...
BUFFALO
257 AM MDT MON SEP 21 2009

...FREEZE WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
TUESDAY MORNING...
...HIGH WIND WARNING IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS CANCELLED THE HIGH
WIND WARNING. A FREEZE WATCH REMAINS IN EFFECT FROM LATE TONIGHT
THROUGH TUESDAY MORNING. 

CLEARING SKIES AND A COLD DRY AIRMASS WILL RESULT IN TEMPERATURES
FALLING TO NEAR OR BELOW FREEZING MONDAY NIGHT AND EARLY TUESDAY
MORNING. THE COLDEST TEMPERATURES ARE EXPECTED ALONG THE LOWER
RIVER VALLEYS. PEOPLE SHOULD TAKE PRECAUTIONS TO PROTECT VEGETABLE
CROPS AND OTHER COLD-SENSITIVE PLANTS FROM THE POSSIBILITY OF A
HARD FROST OR FREEZE EARLY TUESDAY MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.

&&

$$

WYZ016-211500-
/O.CON.KRIW.FZ.W.0003.000000T0000Z-090921T1500Z/
UPPER WIND RIVER BASIN-
INCLUDING THE CITY OF...DUBOIS
257 AM MDT MON SEP 21 2009

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM MDT THIS MORNING...

A FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM MDT THIS MORNING. 

A STRONG COLD FRONT WILL USHER IN MUCH COLDER AIR INTO THE UPPER
WIND RIVER BASIN...WITH SUB FREEZING TEMPERATURES EXPECTED.
ALTHOUGH A FEW AREAS HAVE REACHED FREEZING ALREADY...WIDESPREAD
FREEZING TEMPERATURES ARE EXPECTED FROM CROWHEART TO DUBOIS
THIS MORNING. LOW TEMPERATURES TONIGHT ARE EXPECTED TO RANGE FROM THE
LOWER 30S NEAR CROWHEART...TO THE MID AND UPPER 20S NEAR DUBOIS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL SENSITIVE PLANTS OR
GARDENS.

&&

$$

WYZ003-005-006-011-017>020-028>030-212200-
/O.CON.KRIW.FZ.A.0002.090922T0600Z-090922T1500Z/
CODY FOOTHILLS-SOUTHWEST BIG HORN BASIN-SOUTHEAST BIG HORN BASIN-
SOUTHEAST JOHNSON COUNTY-WIND RIVER BASIN-LANDER FOOTHILLS-
GREEN MOUNTAINS AND RATTLESNAKE RANGE-
NATRONA COUNTY LOWER ELEVATIONS-ROCK SPRINGS AND GREEN RIVER-
FLAMING GORGE-EAST SWEETWATER COUNTY-
INCLUDING THE CITIES OF...CODY...MEETEETSE...THERMOPOLIS...
WORLAND...KAYCEE...RIVERTON...SHOSHONI...LANDER...JEFFREY CITY...
CASPER...ROCK SPRINGS...GREEN RIVER...WAMSUTTER
257 AM MDT MON SEP 21 2009

...FREEZE WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
TUESDAY MORNING...

A FREEZE WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
TUESDAY MORNING. 

CLEARING SKIES AND A COLD DRY AIRMASS WILL RESULT IN TEMPERATURES
FALLING TO NEAR OR BELOW FREEZING MONDAY NIGHT AND EARLY TUESDAY
MORNING. THE COLDEST TEMPERATURES ARE EXPECTED ALONG THE LOWER
RIVER VALLEYS. PEOPLE SHOULD TAKE PRECAUTIONS TO PROTECT
VEGETABLE CROPS AND OTHER COLD-SENSITIVE PLANTS FROM THE
POSSIBILITY OF A HARD FROST OR FREEZE EARLY TUESDAY MORNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.

&&

$$

SMITH

What forecasters said that day

The local office's own words before this high wind warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Riverton, WY wrote its last area forecast discussion before this high wind warning went out at Sep 20, 3:27 AM MDT, 11 hours 12 minutes earlier.

Area forecast discussion, Sep 20, 3:27 AM MDT, 11 hours 12 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
327 AM MDT SUN SEP 20 2009

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT

WELL DEFINED TROUGH WILL MOVE SOUTHEASTWARD FROM SOUTHWESTERN CANADA
INTO CENTRAL MT TODAY WITH THE GFS AND NAM IN GOOD AGREEMENT ON THE
PROGRESSION OF THE TROUGH. A LEADING SHORTWAVE AND ASSOCIATED
PACIFIC COLD FRONT WILL MOVE ACROSS WESTERN WY THIS MORNING AND
ACROSS CENTRAL WY THIS AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS WILL MOVE THROUGH WESTERN WY THIS MORNING WITH LOW
LEVEL CONVERGENCE ALONG THE COLD FRONT AND WEAK INSTABILITY.
CONVECTIVE ACTIVITY WILL DIMINISH DURING THE AFTERNOON WEST OF THE
DIVIDE...AS GFS AND NAM SHOW DRIER AND MORE STABLE AIR MOVING INTO
THE REGION FROM THE WEST. SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
WILL MOVE INTO CENTRAL WY THIS AFTERNOON...AS THE COLD FRONT MOVES
EAST OF THE DIVIDE WHERE LIFTED INDICES ARE PROGGED TO BE SLIGHTLY
BELOW 0 C. STRONG H25 JET CORE OF 100+ KT TO THE WEST OF THE TROUGH
AXIS WILL CAUSE THE TROUGH IN CENTRAL MT THIS EVENING TO DIG SHARPLY
SOUTHEASTWARD ACROSS EASTERN WY TONIGHT. INCREASING LOW AND MID
LEVEL MOISTURE ACROSS JOHNSON AND NATRONA COUNTIES COMBINED WITH
NORTHERLY UPSLOPE FLOW AND MODERATE QG FORCING WILL PRODUCE LIGHT TO
MODERATE PRECIPITATION TONIGHT. POWERFUL SECONDARY COLD FRONT WILL
CAUSE H7 TEMPERATURES TO FALL TO AROUND MINUS 6 C OVER JOHNSON
COUNTY BY 03Z AND OVER NATRONA COUNTY BY 09Z...AND SNOW LEVELS WILL
FALL TO AROUND 6500 FEET. A TREND TO SHIFT THE BAND OF HEAVIEST
PRECIPITATION INTO FAR EASTERN WY AND THE WESTERN DAKOTAS WAS NOTED
IN THE 00Z RUNS OF THE GFS AND NAM. LOWERED PRECIPITATION AMOUNTS
SLIGHTLY IN EASTERN PORTIONS OF CENTRAL WY. THE BIGHORN MOUNTAINS
ARE EXPECTED TO RECEIVE BETWEEN 3 AND 6 INCHES OF SNOW THROUGH 15Z
MONDAY...WHILE CASPER MOUNTAIN COULD RECEIVE 2 TO 4 INCHES THROUGH
18Z. THE LOWER ELEVATIONS OF JOHNSON AND NATRONA COUNTIES COULD SEE
SOME MINOR ACCUMULATIONS...BUT AT THIS TIME IT APPEARS MORE LIKELY
THAT THESE AREAS WILL SEE RAIN CHANGING TO A MIXTURE OF RAIN AND
SNOW WITH BOUNDARY LAYER TEMPERATURES STAYING SEVERAL DEGREES
ABOVE FREEZING.

THE TROUGH WILL CONTINUE TO DROP SOUTHWARD INTO WESTERN NEB MONDAY
AFTERNOON WITH BOTH THE GFS AND NAM CLOSING OFF THE CIRCULATION.
LIGHT PRECIPITATION IS EXPECTED TO END ACROSS NATRONA COUNTY AROUND
18Z. COLD CORE OF AIR OVER WESTERN AND CENTRAL WY MONDAY WILL RESULT
IN HIGH TEMPERATURES 8-12 F BELOW NORMAL. AS THE UPPER LOW CONTINUES
TO MOVE SOUTHWARD ACROSS WESTERN NEB AND INTO WESTERN KS MONDAY
NIGHT...STRONG SUBSIDENCE ON THE NORTHWESTERN SIDE OF THE UPPER LOW
WILL PRODUCE CLEARING ACROSS WY. CLEAR SKIES...LIGHT WINDS AND
DEWPOINTS IN THE LOWER TO MID 20S MONDAY NIGHT WILL PRODUCE STRONG
RADIATIONAL COOLING IN THE LOWER ELEVATIONS OF CENTRAL AND WESTERN
WY WITH A GOOD CHANCE OF A HARD FREEZE ACROSS MUCH OF THE REGION.
LARGE UPPER HIGH CENTERED OVER THE PAC NW WILL BUILD OVER WY FROM
THE NORTHWEST TUESDAY. THIS UPPER HIGH WILL BRING CLEAR SKIES AND
DRY WEATHER TO THE REGION TUESDAY WITH HIGH TEMPERATURES RETURNING
TO NEAR NORMAL.

.LONG TERM...WEDNESDAY THROUGH SUNDAY
TEMPERATURES WILL RECOVER TO NEAR NORMAL IN MOST AREAS WEDNESDAY
AS AN UPPER LEVEL LOW PRESSURE SYSTEM IN EASTERN COLORADO IS
SUPPLANTED BY HIGH PRESSURE MOVING INTO THE INTERMOUNTAIN REGION
FROM THE NORTHWEST. COOLER TEMPS FOR THE EASTERN AND SOUTHERN
ZONES AS THE COOLER AIRMASS TO THE SOUTH RETAINS SOME INFLUENCE
THROUGH THURSDAY. GFS KEEPS H7 TEMPS FOR SWEETWATER COUNTY IN THE
0 TO +2 C RANGE. WHILE ECMWF IS A BIT WARMER AT 2-4 C. HIGH
PRESSURE WILL REMAIN IN PLACE THOUGH FRIDAY. GFS CUTS OFF ANOTHER
UPPER LOW LATE FRIDAY AND PUSHES A COLD FRONT THROUGH THE STATE
EARLY SATURDAY. EURO HAS YET TO RESOLVE A SIMILAR FEATURE. IN ANY
CASE...GFS HAS LITTLE MOISTURE TO GO WITH POTENTIAL DYNAMICS SO
HAVE NOT INCLUDED POPS FOR THE SATURDAY/SUNDAY PERIOD.

&&

.AVIATION...

A TROUGH OF LOW PRESSURE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE AREA TODAY.  ISOLATED TO SCATTERED SHOWERS WILL PRECEDE THE COLD
FRONT WEST OF THE DIVIDE THIS MORNING...THE SHOWERS MORE NUMEROUS
ACROSS THE SOUTHWEST ALONG KRKS-KBPI ROUTES WHERE LOCAL MVFR
CONDITIONS MAY BE ENCOUNTERED. RAPIDLY CLEARING SKIES AND
INCREASING NW WIND WILL OCCUR IN THE WEST BEHIND THE FRONT IN THE
AFTERNOON.

EAST OF THE DIVIDE...ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT DROPPING SOUTH OUT
OF MONTANA THIS AFTERNOON.  THE SHOWERS AND THUNDERSTORMS WILL BE
MOST NUMEROUS VCNTY AND EAST OF A KCOD-KWRL-KCPR LINE.  LOWERING
CIGS AND MORE WIDESPREAD PRECIPITATION WILL FOLLOW THE FRONT SUNDAY
EVENING WITH SNOW LEVELS LOWERING TO NEAR 6500 FEET BY EARLY MONDAY
MORNING.  EXPECT AREAS OF MVFR/IFR CONDITIONS AND MOUNTAIN
OBSCURATIONS EAST OF THE DIVIDE AFTER 06Z MONDAY.

&&

.FIRE WEATHER...

A PACIFIC COLD FRONT WILL MOVE ACROSS WESTERN WYOMING THIS MORNING
AND CONTINUE ACROSS CENTRAL WYOMING THIS AFTERNOON. DAYTIME
TEMPERATURES WILL BE 10-14 F COOLER THAN TEMPERATURES ON
SATURDAY...AND AFTERNOON RELATIVE HUMIDITIES WILL BE IN THE UPPER
TEENS AND 20S IN THE LOWER ELEVATIONS. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED ALONG THE COLD FRONT IN  THE MORNING WEST
OF THE DIVIDE AND IN THE AFTERNOON EAST OF THE DIVIDE. A STRONGER
COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT. IT WILL BRING MUCH
COOLER AIR TO THE REGION LATE TONIGHT AND MONDAY. HIGH TEMPERATURES
MONDAY WILL BE 8-12 F BELOW NORMAL. UPSLOPE FLOW AND INCREASING
MOISTURE EAST OF THE DIVIDE LATE TONIGHT AND MONDAY MORNING IS
EXPECTED TO BRING WETTING RAIN/SNOW TO JOHNSON AND NATRONA COUNTIES.
SNOW LEVELS WILL BE AROUND 6500 FEET LATE TONIGHT AND MONDAY MORNING
WITH 3-6 INCHES POSSIBLE IN THE BIGHORN MOUNTAINS AND 2-4 INCHES ON
CASPER MOUNTAIN.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

SHORT TERM...SMITH
LONG TERM...BERC
AVIATION...AEM
FIRE WEATHER...SMITH
Hazardous weather outlook, Sep 20, 5:01 AM MDT, 9 hours 38 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RIVERTON WY
501 AM MDT SUN SEP 20 2009

WYZ001>020-022>030-211101-
ABSAROKA MOUNTAINS-BIGHORN MOUNTAINS SOUTHEAST-
BIGHORN MOUNTAINS WEST-CASPER MOUNTAIN-CODY FOOTHILLS-
EAST SWEETWATER COUNTY-FLAMING GORGE-
GREEN MOUNTAINS AND RATTLESNAKE RANGE-JACKSON HOLE-LANDER FOOTHILLS-
NATRONA COUNTY LOWER ELEVATIONS-NORTH BIG HORN BASIN-
NORTHEAST JOHNSON COUNTY-OWL CREEK AND BRIDGER MOUNTAINS-
ROCK SPRINGS AND GREEN RIVER-SALT RIVER AND WYOMING RANGES-
SOUTH LINCOLN COUNTY-SOUTHEAST BIG HORN BASIN-
SOUTHEAST JOHNSON COUNTY-SOUTHWEST BIG HORN BASIN-STAR VALLEY-
TETON AND GROS VENTRE MOUNTAINS-UPPER GREEN RIVER BASIN-
UPPER GREEN RIVER BASIN FOOTHILLS-UPPER WIND RIVER BASIN-
WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST-
YELLOWSTONE NATIONAL PARK-
501 AM MDT SUN SEP 20 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING.

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED WEST
OF THE DIVIDE THIS MORNING AND EAST OF THE DIVIDE THIS AFTERNOON.
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING GUSTY WIND...SMALL HAIL
AND LIGHTNING.

A STRONG COLD FRONT WILL MOVE SOUTHWARD ACROSS CENTRAL WYOMING
TONIGHT. MOISTURE ASSOCIATED WITH THE FRONT AND UPSLOPE
FLOW BEHIND THE FRONT WILL BRING MEASURABLE RAIN AND SNOW TO AREAS
EAST OF THE DIVIDE TONIGHT. SNOW LEVELS WILL FALL TO AROUND 6500
FEET LATE TONIGHT. 2 TO 4 INCHES OF SNOW ARE EXPECTED IN THE BIGHORN
MOUNTAINS AND 1 TO 2 INCHES ON CASPER MOUNTAIN.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

UPSLOPE FLOW WILL CONTINUE THROUGH MONDAY MORNING IN EASTERN
PORTIONS OF CENTRAL WYOMING WITH 3 TO 6 INCHES OF TOTAL SNOWFALL
POSSIBLE IN THE BIGHORNS AND 2 TO 4 INCHES POSSIBLE ON CASPER
MOUNTAIN.

SKIES WILL CLEAR ACROSS CENTRAL AND WESTERN WYOMING MONDAY NIGHT.
WITH CLEAR SKIES...LIGHT WINDS AND A COLD AIRMASS IN PLACE MONDAY
NIGHT...A HARD FREEZE IS LIKELY ACROSS MANY OF THE LOWER ELEVATIONS
OF CENTRAL AND WESTERN WYOMING.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT HAIL AND WIND GUSTS IN EXCESS OF 40
MPH TODAY. THANK YOU.

TEAM RIVERTON

In the hours before

Special weather statement, Sep 20, 1:06 PM MDT, 1 hour 33 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
106 PM MDT SUN SEP 20 2009

WYZ012-013-202100-
JACKSON HOLE-TETON AND GROS VENTRE MOUNTAINS-
106 PM MDT SUN SEP 20 2009

AN WEST-TO-EAST ORIENTED BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS
EXISTS FROM NEAR DRIGGS TO JUST NORTH OF MOOSE TO TOGWOTEE PASS.
THIS BAND WILL GRADUALLY DRIFT SOUTH THROUGH 3 PM...AFFECTING TETON
VILLAGE...MOOSE...KELLY...AND THE NORTHERN COMMUNITIES OF JACKSON.
EXPECT BRIEF LIGHT TO MODERATE RAIN...A FEW LIGHTNING STRIKES AND
WIND GUSTS TO 30 MPH.  THERE IS ANOTHER BAND ALONG THE SOUTHERN
YELLOWSTONE PARK BOUNDARY DRIFTING SOUTH AS WELL.

TWB
Special weather statement, Sep 20, 1:32 PM MDT, 1 hour 7 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
132 PM MDT SUN SEP 20 2009

WYZ016-202100-
UPPER WIND RIVER BASIN-
132 PM MDT SUN SEP 20 2009

AN WEST-TO-EAST ORIENTED BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS
EXISTS FROM TOGWOTEE PASS TO NORTH OF DUBOIS. THIS BAND WILL
GRADUALLY DRIFT SOUTH THROUGH 3 PM...AFFECTING DUNOIR...UNION PASS
AND DUBOIS.  EXPECT BRIEF LIGHT TO MODERATE RAIN...A FEW LIGHTNING
STRIKES AND WIND GUSTS TO 40 MPH.

TWB
Special weather statement, Sep 20, 1:51 PM MDT, 48 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
151 PM MDT SUN SEP 20 2009

WYZ015-019-026-030-202030-
EAST SWEETWATER COUNTY-GREEN MOUNTAINS AND RATTLESNAKE RANGE-UPPER
GREEN RIVER BASIN-WIND RIVER MOUNTAINS EAST-
151 PM MDT SUN SEP 20 2009

...SIGNIFICANT WEATHER ADVISORY FOR FREMONT AND SWEETWATER COUNTIES
UNTIL 230 PM MDT...

AT 149 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR OREGON BUTTES...OR 33 MILES EAST OF
FARSON...MOVING EAST AT 20 MPH.

PENNY SIZE HAIL...AND WINDS AROUND 40 MPH ARE POSSIBLE WITH THIS
STORM.

RESIDENTS IN NORTHERN SWEETWATER AND SOUTHERN FREMONT COUNTIES...
INCLUDING THE LOCATION OF OREGON BUTTES...SHOULD MONITOR THE WEATHER
SITUATION CLOSELY. LISTEN FOR POSSIBLE WARNINGS AND BE PREPARED TO
TAKE APPROPRIATE ACTION SHOULD SEVERE WEATHER THREATEN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE INDOORS IMMEDIATELY AS THIS STORM APPROACHES YOUR LOCATION. THIS
IS A POTENTIALLY DANGEROUS STORM. IF YOU ARE IN ITS PATH...YOU SHOULD
BE PREPARED FOR GUSTY WINDS...HAIL...AND DEADLY CLOUD TO GROUND
LIGHTNING. IF A STURDY STRUCTURE IS NOT AVAILABLE...SEEK SHELTER IN A
VEHICLE WITH THE WINDOWS UP.

&&

REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4220 10816 4195 10829 4219 10899 4235 10891
TIME...MOT...LOC 1950Z 287DEG 19KT 4224 10881

T. BAKER
Special weather statement, Sep 20, 2:10 PM MDT, 29 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
210 PM MDT SUN SEP 20 2009

WYZ028>030-202100-
EAST SWEETWATER COUNTY-FLAMING GORGE-ROCK SPRINGS AND GREEN RIVER-
210 PM MDT SUN SEP 20 2009

...SIGNIFICANT WEATHER ADVISORY FOR SWEETWATER COUNTY UNTIL 300 PM
MDT...

AT 209 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 9 MILES NORTH OF STATE HWY 414 MILE MARKER 140...
OR 11 MILES NORTHWEST OF MANILA...MOVING EAST AT 30 MPH.

PEA SIZE HAIL...AND WINDS AROUND 40 MPH ARE POSSIBLE WITH THIS STORM.

RESIDENTS IN SOUTHWESTERN SWEETWATER COUNTY...INCLUDING THE LOCATIONS
OF STATE HWY 530 MILE MARKER 30 TO 40...SQUAW HOLLOW BOAT RAMP ON
FLAMING GORGE...U.S. HWY 191 MILE MARKER 550 TO 540...SHOULD MONITOR
THE WEATHER SITUATION CLOSELY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF ON OR NEAR FLAMING GORGE...GET OUT OF THE WATER AND MOVE INDOORS
OR INSIDE A VEHICLE. REMEMBER...LIGHTNING CAN STRIKE OUT TO 15 MILES
FROM THE PARENT THUNDERSTORM. IF YOU CAN HEAR THUNDER...YOU ARE
CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER NOW.
DONT BE CAUGHT ON THE WATER IN A THUNDERSTORM

&&

REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4107 10994 4124 10989 4116 10904 4099 10908
      4099 10956
TIME...MOT...LOC 2010Z 281DEG 25KT 4114 10979

T. BAKER
Special weather statement, Sep 20, 2:21 PM MDT, 18 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
221 PM MDT SUN SEP 20 2009

WYZ005-007-017-202100-
OWL CREEK AND BRIDGER MOUNTAINS-SOUTHWEST BIG HORN BASIN-WIND RIVER
BASIN-
221 PM MDT SUN SEP 20 2009

...SIGNIFICANT WEATHER ADVISORY FOR FREMONT AND HOT SPRINGS COUNTIES
UNTIL 300 PM MDT...

AT 219 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 15 MILES WEST OF
U.S. HWY 20/789 MILE MARKER 120 TO STATE HWY 134 MILE MARKER 10...OR
ALONG A LINE EXTENDING FROM 17 MILES SOUTHWEST OF THERMOPOLIS TO 15
MILES NORTH OF RIVERTON...MOVING EAST AT 25 MPH.

PEA SIZE HAIL...AND WINDS AROUND 40 MPH ARE POSSIBLE WITH THESE
STORMS.

RESIDENTS IN CENTRAL FREMONT AND SOUTHERN HOT SPRINGS
COUNTIES...INCLUDING BOYSEN RESERVOIR...SHOSHONI AND MISSOURI
VALLEY...SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR
POSSIBLE WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD
SEVERE WEATHER THREATEN.

REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4357 10791 4315 10801 4315 10865 4357 10855
TIME...MOT...LOC 2020Z 270DEG 20KT 4348 10844 4324 10850

T. BAKER
Special weather statement, Sep 20, 2:33 PM MDT, 6 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
233 PM MDT SUN SEP 20 2009

WYZ019-030-202115-
EAST SWEETWATER COUNTY-GREEN MOUNTAINS AND RATTLESNAKE RANGE-
233 PM MDT SUN SEP 20 2009

...SIGNIFICANT WEATHER ADVISORY FOR SWEETWATER COUNTY UNTIL 315 PM
MDT...

AT 232 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 18 MILES SOUTHEAST OF OREGON BUTTES...OR 43 MILES
NORTHWEST OF WAMSUTTER...MOVING EAST AT 25 MPH.

NICKEL SIZE HAIL IS POSSIBLE WITH THIS STORM.

RESIDENTS IN NORTHERN SWEETWATER COUNTY...SHOULD MONITOR THE WEATHER
SITUATION CLOSELY.

REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4213 10797 4189 10806 4204 10870 4222 10864
TIME...MOT...LOC 2033Z 284DEG 23KT 4211 10855

T. BAKER

The office that day

Everything else NWS Riverton, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 8:23 PM MDTSpecial Weather StatementRIW52 min
Sep 20, 1:51 PM MDTSpecial Weather StatementRIW39 min
Sep 20, 2:21 PM MDTSpecial Weather StatementRIWHot Springs39 min
Sep 20, 2:33 PM MDTSpecial Weather StatementRIW42 min
Sep 20, 2:39 PM MDTFreeze WarningRIWFremont18 hr
Sep 20, 2:41 PM MDTWinter Weather AdvisoryRIWNatrona18 hr
Sep 20, 2:56 PM MDTSpecial Weather StatementRIWFremont49 min
Sep 20, 3:19 PM MDTSpecial Weather StatementRIWHot Springs41 min
Sep 20, 3:35 PM MDTSpecial Weather StatementRIWFremont40 min
Sep 20, 4:38 PM MDTSpecial Weather StatementRIWNatrona37 min
Sep 20, 5:02 PM MDTSpecial Weather StatementRIWNatrona43 min
Sep 20, 5:14 PM MDTSpecial Weather StatementRIWNatrona46 min

Nearby

High Wind Warnings in Wyoming, 2009Every high wind warning in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.