Flash Flood Warning 23, NWS Cheyenne, WY

000
WGUS75 KCYS 170012
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
612 PM MDT SAT AUG 16 2008

WYC021-170100-
/O.CON.KCYS.FF.W.0023.000000T0000Z-080817T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LARAMIE WY-
612 PM MDT SAT AUG 16 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM MDT FOR
CENTRAL LARAMIE COUNTY...

LOCAL LAW ENFORCEMENT OFFICIALS HAVE REPORTED THAT THE 1800 BLOCK
OF COUNTY ROAD 143 NEAR THE HILLSDALE COMMUNITY HAS BEEN WASHED 
OUT.  HILLSDALE IS ABOUT 15 MILES EAST OF CHEYENNE.  RUNOFF FROM 
THE HEAVIER RAINS OF THIS AFTERNOON HAS JUST ABOUT ENDED AND ONLY
A FEW LIGHT RAIN SHOWERS ARE EXPECTED TO PERSIST TONIGHT.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

LAT...LON 4128 10457 4128 10438 4116 10437 4116 10456

$$

JLH

000
WGUS75 KCYS 170059
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
659 PM MDT SAT AUG 16 2008

WYC021-170105-
/O.EXP.KCYS.FF.W.0023.000000T0000Z-080817T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LARAMIE WY-
659 PM MDT SAT AUG 16 2008

...THE FLASH FLOOD WARNING WILL EXPIRE AT 700 PM MDT FOR CENTRAL
LARAMIE COUNTY...

LOCAL LAW ENFORCEMENT OFFICIALS HAVE CLOSED THE 1800 BLOCK OF
COUNTY ROAD 143 ABOUT THREE MILES NORTH OF HILLSDALE AS THE HEAVY
RAIN OF THE PAST TWO DAYS WASHED OUT PART OF THE ROAD.  HILLSDALE
IS SOME 15 MILES EAST OF CHEYENNE.    

ALL OF THE RUNOFF FROM THE HEAVIER RAINS OF THIS AFTERNOON HAS
ENDED...AND ONLY A FEW LINGERING SPRINKLES ARE POSSIBLE TONIGHT. 

LAT...LON 4128 10457 4128 10438 4116 10437 4116 10456

$$

JLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
140 PM MDT SAT AUG 16 2008

.SHORT TERM...TONIGHT THROUGH MONDAY...
VERY SLOW MOVING UPPER LOW WAS LOCATED OVER EXTREME NORTHWEST
COLORADO EARLY THIS AFTERNOON. A SHORTWAVE TROUGH ROTATING
AROUND THAT FEATURE EXTENDED INTO SOUTHEAST COLORADO. SHOWERS
AND SOME THUNDERSTORMS WERE LOCATED AHEAD OF THE SHORTWAVE
TROUGH OVER SOUTHEAST WYOMING. RAINFALL INTENSITY AND RATES
HAVE INCREASED IN LARAMIE COUNTY SINCE 18Z. MODELS PLACE BEST
Q VECTOR DIVERGENCE OVER THE ENTIRE CWA AT 00Z AND THEN SHIFTS
SLOWLY SOUTH. RECENT SATELLITTE IMAGERY WOULD FAVOR PLACING
THE BEST SYNOPTIC LIFT OVER THE SOUTHERN THIRD OF THE CWA
THROUGH EARLY TONIGHT. WILL KEEP THE HIGH POPS THROUGH EARLY
TONIGHT IN THAT PART OF THE CWA AND THEN TAPER OFF POPS
TOWARDS THE NORTH. WILL NEED TO MONITOR THE POTENTIAL FOR
FLOODING DURING THAT TIME AS ONE HOUR RATES MAY APROACH FLASH
FLOOD GUIDANCE AT LEAST IN LARAMIE COUNTY AND THE SOUTHERN
LARAMIE RANGE. THROUGH MONDAY THE UPPER LOW WILL CONTINUE TO
MOVE SLOWLY TO THE SOUTHEAST AND FILL. BY 00Z TUESDAY THE
FEATURE IS PLACED OVER THE TEXAS PANHANDLE BY ALL MODELS.
AS THE UPPER LOW GRADUALLY MOVES AWAY FROM THE CWA...SHOWERS
AND THEN CLOUDS WILL TAPER OFF SLOW,Y FROM THE NORTH TO THE
SOUTH.  MODELS ALL LINGER SOME QPF OVER THE FAR SOUTH PART
OF THE CWA THROUGH MONDAY...WITH THE ECMWF FURTHER NORTH.
SUNDAY NIGHT AND MONDAY WILL BE DRY AS A RIDGE ALOFT BUILDS
JUST WEST OF THE CWA. TEMPERATURES WILL MODERATE SOME ON SUNDAY
AND THEN RETURN TO NEAR NORMAL ON MONDAY.

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY. OVERALL GFS AND ECMWF
IN AGREEMENT AS BOTH ARE INDICIATING MAJOR SHIFT IN LARGE SCALE
FLOW...WITH PACFIC NORTHWEST SYSTEM MOVING EAST MUCH FASTER THAN
PREVIOUS RUNS. BUT GFS ENSEMBLES ARE SOMEWHAT BIMODAL WITH BOTH
SLOWER AND FASTER MEMBERS. GFS AND ECMWF SEEM TOO FAST SO WILL GO
WITH THE GFS ENSEMBLES AVERAGE AND SLOW THINGS DOWN A BIT.

LAST REMNANTS OF UPPER LOW WILL HAVE DRIFTED INTO THE SOUTHERN
PLAINS BY TUESDAY...SO NO IMPACT ON WEATHER HERE. HIGHLY AMPLIFIED
RIDGE FROM SOUTHWEST DESERTS TO NORTHERN PLAINS WILL KEEP QUIET
AND DRY WEATHER ACROSS AREA FOR TUESDAY THROUGH THURSDAY. LOW OFF
THE PACIFIC NORTHWEST COAST WILL TURN THE UPPER FLOW TO THE
SOUTHWEST THURSDAY MORNING BUT ANY SHORT WAVE ENERGY WITH THIS
SYSTEM WILL REMAIN WELL NORTH AND WEST OF THE CWA...SO HAVE KEPT
THE GRIDS MOSTLY DRY THROUGH FRIDAY. THE ONLY CHANCE OF RAIN WILL
BE MAINLY OVER FAR NORTHERN PARTS OF CWA THURSDAY NIGHT INTO
SATURDAY. BUT WITH THE UNCERTAINTY OF THE EASTWARD PROGRESSION OF
SYSTEM DUE TO DOWNSTREAM CONSIDERATIONS OF TROPICAL STORM
FAY...EXPECT THAT CHANCES OF RAIN MAY PERSIST INTO NEXT WEEKEND
DUE TO SLOWER MOVEMENT...THOUGH PUBLISHED GRIDS CURRENTLY ARE
STAYING ON THE CLIMATOLOGICALLY DRY SIDE FOR NOW DUE TO THE
UNCERTAINTY.

&&

.AVIATION...MVFR CEILINGS AND VISIBILITIES IN RAIN WILL CONTINUE
OVER THE SOUTHERN THIRD OF THE CWA THROUGH EARLY TONIGHT, THEN
WITH THE ABUNDANT LOW LEVEL MOISTURE...CONDITIONS WILL LOWER
AFTER 06Z WITH AT LEAST AREAS OF IFR CEILINGS AND VISIBILITIES
IN FOG. SOME SHOWERS AND STORMS WILL LINGER NEAR THE COLORADO
BORDER ON SUNDAY WITH BRIEF MVFR CEILINGS AND VISIBILITIES
EXPECTED. VFR CONDITIONS WILL BE OVER THE ENTIRE CWA SUNDAY NIGHT
AND MONDAY. LIGHT RIME ICING IS QUITE POSSIBLE TONIGHT AND
SUNDAY MORNING OVER THE SOUTHERN THIRD OF THE CWA AROUND 11000
FEET MSL.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

SHORT TERM/AVIATION...WEILAND
LONG TERM...EISE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
956 AM MDT SAT AUG 16 2008

NEZ001>003-019>021-054-055-WYZ059>070-171115-
SIOUX-DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-
CHEYENNE-CONVERSE-NIOBRARA-SOUTHWEST CARBON-NORTH CARBON-
SNOWY RANGE-NORTH LARAMIE RANGE-LARAMIE VALLEY-LARAMIE RANGE-
PLATTE-GOSHEN-CHEYENNE FOOTHILLS-PINE BLUFFS-
956 AM MDT SAT AUG 16 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA
PANHANDLE AND SOUTHEAST WYOMING.

.DAY ONE...THIS AFTERNOON AND TONIGHT

ISOLATED THUNDERSTORMS WILL OCCUR THIS AFTERNOON AND EVENING OVER
SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE.  THE
WIDESPREAD SHOWERS WILL BE MAINLY SOUTH OF A LARAMIE TO WHEATLAND
TO KIMBALL LINE THROUGH THE EVENING.  ANY STORMS THAT FORM WILL
NOT BE STRONG...BUT WILL PRODUCE HEAVIER RAINFALL AND SMALL HAIL.
THE RAINFALL WILL PRODUCE HIGHER WATER LEVELS IN RIVERS AND STREAMS
AS WELL AS PONDING OF WATER IN LOW LYING AREAS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS NEAR THE COLORADO BORDER
ON SUNDAY. THERE IS ALSO A SLIGHT CHANCE OF LATE DAY THUNDERSTORMS
ON FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THIS AFTERNOON OR TONIGHT.

&&

THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND
CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT...
HTTP://WEATHER.GOV/CHEYENNE

WEILAND