Snow Advisory 1, NWS Cheyenne, WY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1111 AM MST TUE JAN 8 2008

.UPDATE...QUITE INTERESTING WEATHER SCENARIO SHAPING UP THROUGH
THURSDAY...AS IS TYPICAL WITH THIS TYPE OF A PROGRESSIVE WEATHER
PATTERN AND IN OUR NECK OF THE WOODS. FOR TODAY...ADJUSTED
TEMPERATURES...DEWPOINTS...WINDS AND CLOUDS TO MATCH TRENDS. SNOW
COVER WILL RETARD WARMING ALTHOUGH AMAZING THINGS HAPPEN...LOW
LEVEL WARMING...WITH DOWNSLOPE WINDS TO THE LEE OF THE MOUNTAINS
DOING THEIR KATABATIC WARMING...ALSO KNOWN AS COMPRESSIONAL
WARMING OR HEATING...THUS HAVE BOOSTED HIGHS TODAY A TAD AT SOME
LOCALES. RUBIN

&&

.PREV DISCUSSION... /ISSUED 926 AM MST TUE JAN 8 2008/

UPDATE...WENT AHEAD AND ALLOWED THE PROACTIVE HIGH WIND WARNING FOR
PLATTE COUNTY WYOMING TO EXPIRE AT 9 AM BASED ON BORDEAUX SURFACE
OBSERVATIONS AND PROGGED LOW/MID LEVEL GRADIENTS AND ISOTACH PROGS
FOR TODAY.   RUBIN

PREV DISCUSSION... /ISSUED 653 AM MST TUE JAN 8 2008/

SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
QUICK UPDATE FOR ISSUING THE HIGH WIND WARNING FOR THE BORDEAUX
AREA THROUGH 900 AM MST.

WATER VAPOR IMAGERY CONTINUES TO SHOW A 110 KNOT JET STREAK
MOVING EAST ACROSS THE TEXAS PANHANDLE EARLY THIS MORNING. AN
ASSOCIATED MID-LEVEL TROUGH IS LOCATED ACROSS WESTERN KANSAS AND
EASTERN COLORADO...AND MOISTURE WRAPPING NORTH AND WEST AROUND
THE BASE OF THE 700 MB LOW CONTINUES TO BE OVER SOUTHEAST WYOMING
AND WESTERN NEBRASKA THIS MORNING. THIS CLOUD COVER WILL DECREASE
AS THE STORM SYSTEM MOVES FARTHER EAST ACROSS THE GREAT PLAINS
THIS MORNING...AND ANOTHER 110 KNOT JET STREAK FROM NORTH TO
SOUTH ACROSS THE AREA ALLOWS THE UPPER LEVEL RIDGE TO MOVE
OVERHEAD. THE PRESENCE OF THE RIDGE AND DECREASED CLOUDS WILL
TRANSLATE INTO SLIGHTLY WARMER CONDITIONS ACROSS THE FORECAST
AREA TODAY.

MID-LEVEL MOISTURE WILL INCREASE AHEAD OF THE NEXT UPPER TROUGH AS
UPPER WINDS BACK FROM WEST TO SOUTHWEST TONIGHT AND HAVE INCREASED
PRECIPITATION CHANCES TO LIKELY...WITH WEST FACING SLOPES MOST
FAVORED TONIGHT IN THE SIERRA MADRE AND SNOWY RANGES.

WINDS ALSO APPEAR TO BE A CONCERN FOR TONIGHT NEAR BORDEAUX. THE
MODELS ARE SHOWING A SITUATION VERY SIMILAR TO PAST FEW NIGHTS
WHEN HIGH WIND CRITERIA WAS MET FOR SEVERAL HOURS. THE UPPER RIDGE
AXIS WILL BE EAST OF THE AREA WITH THE 500 MB TROUGH AXIS STILL TO
THE WEST. SUPPORTING FACTORS INCLUDE THE DEVELOPING LEE TROUGH AND
THE PASSAGE OF THE 700 MB TROUGH AXIS. BELIEVE THAT SUBSIDENCE
BEHIND THE 700 MB TROUGH VORTICITY MAXIMA ENHANCED THE MIXING DOWN
OF THE STRONG MID LEVEL WINDS DURING THE PAST FEW EVENTS...AND
COMBINED WITH THE INCREASING PRESSURE GRADIENT SHOULD SUPPORT
ANOTHER EPISODE OF STRONG WINDS IN THE GAP FAVORED AREA OF
BORDEAUX. OTHER AREAS OF PLATTE COUNTY WILL LIKELY HAVE JUST
BREEZY CONDITIONS OVERNIGHT. AT THIS TIME...WILL GO WITH A HIGH
WIND WATCH FOR PLATTE COUNTY VALID THIS EVENING THROUGH MID-
MORNING WEDNESDAY.

MID-LEVEL WINDS WILL VEER MORE TO THE NORTHWEST DURING THE DAY
WEDNESDAY AS THE UPPER TROUGH MOVES OVER THE AREA. WITH UPPER
LEVEL ENERGY BEGINNING TO AFFECT THE AREA...HAVE UPGRADED MOUNTAIN
PRECIPITATION CHANCES TO LIKELY. CONTINUING SURFACE PRESSURE FALLS
EAST OF THE MOUNTAINS SHOULD CONTINUE TO KEEP THE AREA DRY DURING
THE DAYLIGHT HOURS OF WEDNESDAY. A SURFACE COLD FRONT WILL SHIFT
THE WINDS TO NORTHWEST MID-AFTERNOON WEDNESDAY WITH TEMPERATURES
EXPECTED TO FALL THROUGH THE AFTERNOON HOURS. WILL SPREAD AT LEAST
A SLIGHT CHANCE FOR SNOW SHOWERS ACROSS AREAS EAST OF THE LARAMIE
RANGE WEDNESDAY NIGHT EXPECTING CONTINUE LIFT BEHIND THE FRONT.
ALSO WEDNESDAY NIGHT WILL GRADUALLY DECREASE CHANCES FOR THE
WESTERN ZONES AND HIGHER TERRAIN AS DRIER AIRMASS IS EXPECTED TO
MOVE INTO SOUTHEAST WYOMING AND THE NEBRASKA PANHANDLE.

LONG TERM...THURSDAY THROUGH MONDAY...
NW FLOW WILL BE ALOFT OVER THE CWA THUR.  THE UPPER
RIDGE OVER THE AREA WILL BREAK DOWN THURS NIGHT WITH A DISTURBANCE
MOVING SE ACROSS THE FORECAST AREA.  BRISK WINDS WILL OCCUR IN THE
MORNING AND INCREASE AS THE DAY GOES ON AS 700 MB AND SURFACE
GRADIENTS TIGHTEN.  WILL KEEP A SLIGHT CHANCE OF SNOW SHOWERS IN THE
MOUNTAINS...BUT STRONG DOWNSLOPE WINDS WILL RESULT IN DRY CONDITIONS
ELSEWHERE.  NW FLOW WILL CONT ALF FRI AS AN UPPER RIDGE BUILDS INTO
THE PAC NW.  BRISK DOWNSLOPE WINDS WILL CONT AT THE SURFACE...SO
WILL CONT THE DRY CONDITIONS.  OROGRAPHIC EFFECTS WILL ONCE AGAIN
PRODUCE SNOW SHOWERS IN THE MOUNTAINS.  FOR SAT...THE FLOW ALOFT
WILL BECOME NORTHERLY AS THE UPPER RIDGE AXIS MOVES ACROSS SOUTHERN
CANADA AND ANOTHER UPPER RIDGE BUILDS ON THE WEST COAST.  SFC
GRADIENT WILL TIGHTEN AGAIN...RESULTING IN WINDY CONDITIONS ACROSS
THE AREA.  WILL KEEP THE SAME PATTERN GOING WITH SNOW SHOWERS IN THE
MOUNTAINS AND DRY ELSEWHERE.  NORTH FLOW WILL CONT ALF SUN AS THE
NORTHERN PORTION OF THE UPPER RIDGE GETS PUSHED EAST BY AN UPPER
TROUGH DEEPENING OVER SOUTHERN CANADA.  SNOW SHOWERS WILL LIKELY
MAKE IT EAST OF THE LARAMIE RANGE DURING THE DAY SUN.  FINALLY...DRY
CONDITIONS WILL PREVAIL ACROSS THE ENTIRE AREA MON AS SFC LEE TROUGH
SETS UP ACRS ERN WY/WRN NEB.  HIGH TEMPERATURES WILL BE AROUND
NORMAL EACH DAY.

AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY AND TONIGHT ACROSS
ALL BUT THE MOUNTAINS OF SOUTH CENTRAL WYOMING. IN THE
MOUNTAINS...VFR CONDITIONS WILL PREVAIL TODAY BUT MOUNTAIN
OBSCURATION WILL THEN BECOME POSSIBLE TONIGHT AS CLOUD COVER AND
SNOW SHOWERS DEVELOP OVER THE HIGHER TERRAIN OF CARBON COUNTY.
STRONG WINDS JUST ABOVE MOUNTAIN TOP TONIGHT WILL LIKELY CREATE
TURBULENCE ALONG AND EAST OF THE FRONT RANGE. CARPENTER

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 6 PM TUESDAY TO 9 AM WEDNESDAY FOR WYZ067.
NE...NONE.

&&

UPDATE...RUBIN
SHORT TERM/AVIATION...SJC
LONG TERM....KMD

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE CHEYENNE WY
932 AM MST TUE JAN 8 2008

NEZ001>003-019>021-054-055-WYZ059>062-064>066-068>070-091400-
SIOUX-DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-
CHEYENNE-CONVERSE-NIOBRARA-SOUTHWEST CARBON-NORTH CARBON-
NORTH LARAMIE RANGE-LARAMIE VALLEY-LARAMIE RANGE-GOSHEN-
CHEYENNE FOOTHILLS-PINE BLUFFS-
932 AM MST TUE JAN 8 2008

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

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

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

WYZ067-091400-
PLATTE-
932 AM MST TUE JAN 8 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST WYOMING.

.DAY ONE...TODAY AND TONIGHT

WEST WINDS OF 25 TO 40 MPH WITH GUSTS TO 50 MPH CAN BE EXPECTED
TODAY.

A HIGH WIND WATCH IS IN EFFECT FROM 6 PM TODAY THROUGH THE REST OF
TONIGHT. STRONG WEST WINDS OF 35 TO 45 MPH WITH GUSTS TO 65 MPH ARE
POSSIBLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A HIGH WIND WATCH IS IN EFFECT UNTIL 9 AM WEDNESDAY. STRONG WEST
WINDS OF 35 TO 45 MPH WITH GUSTS TO 65 MPH ARE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

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

WYZ063-091400-
SNOWY RANGE-
932 AM MST TUE JAN 8 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST WYOMING.

.DAY ONE...TODAY AND TONIGHT

SNOW IS LIKELY ACROSS THE AREA TONIGHT. SNOW ACCUMULATIONS WILL BE
AN INCH OR TWO BY LATE TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

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

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
1218 PM MST TUE JAN 08 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1200 PM     NON-TSTM WND GST ARLINGTON               41.59N 106.21W
01/08/2008  M63 MPH          CARBON             WY   MESONET

            SUST AT 40 MPH

&&