National Weather Service Raw Text Product

400 
FXUS65 KCYS 062217
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
317 PM MST SUN JAN 6 2013

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...

HIGH TEMPS WARMED UP NICELY TODAY WITH 700MB TEMPS RISING TO
AROUND 2C AND SOUTHWESTERLY LLVL FLOW. WIND GUSTS HAVE GENERALLY
REMAINED BELOW 40 MPH ACROSS SOUTHEAST WYOMING. WAS NICE TO SEE
THE LARAMIE VALLEY WAM INTO THE UPPER 30S THIS AFTERNOON AS THE
PERSISTENT SFC INVERSION ERODED AROUND MIDDAY. SHORTWAVE THAT IS
CURRENTLY MOVING ACROSS MONTANA WILL CONTINUE EASTWARD THIS
EVENING WITH THE SFC PRESSURE GRADIENT WEAKENING BY LATE TONIGHT.
FAIRLY QUIET WEATHER DAY ON MONDAY...WITH SLIGHTLY COOLER HIGHS
(700MB TEMPS DROP TO -2C). ANOTHER STRONGER SHORTWAVE WILL QUICKLY
DIVE SOUTHEASTWARD ACROSS MONTANA ON MONDAY EVENING AND INTO THE
DAKOTAS BY TUESDAY. THIS WILL SET THE STAGE FOR A POTENTIAL HIGH
WIND EVENT ACROSS THE WIND PRONE AREAS OF SOUTHEAST WYOMING
STARTING MONDAY NIGHT.

CONFIDENCE IS STARTING TO INCREASE THAT THE WIND PRONE AREAS WILL
SEE STRONG WINDS ON MONDAY NIGHT INTO TUESDAY MORNING. SEVERAL
PARAMETERS COME TOGETHER DURING THIS PERIOD THAT FAVOR HIGH WINDS.
THE 700MB CAG-CPR GRADIENT INCREASES TO 60 METERS BY 06Z TUESDAY
AND REMAINS ABOVE 50 METERS THROUGH 18Z. IN ADDITION...ALTHOUGH
THE AXIS OF STRONGEST WESTERLY 700MB WINDS REMAIN ACROSS MONTANA
AND NORTHERN WYOMING...THE GFS AND NAM SHOW THEM INCREASING TO 50
KTS BY 12Z TUES IN SOUTHEAST WYOMING. THE REGION IS ALSO IN THE
SUBSIDENT RIGHT EXIT REGION OF THE UPPER JET ON MONDAY NIGHT.
ISSUED A HIGH WIND WATCH FOR THE WIND PRONE AREAS CONSIDERING THE
ABOVE FAVORABLE CONDITIONS. SFC WINDS SHOULD BEGIN TO COME DOWN BY
LATE IN THE AFTERNOON ON TUESDAY AS THE LLVL GRADIENTS RELAX AND
THE UPPER JET PULLS OFF TO THE EAST. LOW TEMPS WILL BE CONSIDERABLY
WARMER ON MONDAY NIGHT...ESPECIALLY OVER SOUTHEAST WYOMING WITH
ENHANCED MIXING FROM THE STRONGER WINDS. KEPT POPS IN THE SLIGHT
CHANCE CATEGORY FOR THE SIERRA MADRE AND SNOWY RANGES ON TUESDAY
MORNING AS THE MOISTURE IS PROGGED TO BE LIMITED WITH THIS SYSTEM.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

WARMEST DAY OF THE WEEK LOOKS TO TAKE PLACE WEDNESDAY AS WE ARE
UNDER A BROAD...FLAT RIDGE IN THE UPPER LEVELS. LOOKS TO BE A
PRETTY BREEZY DAY WITH DOWNSLOPING WINDS OFF THE LARAMIE RANGE AND
700MB TEMPERATURES AROUND +2C. LOOKING AT LOW 50 HIGHS EAST OF THE
LARAMIE RANGE WITH UPPER 30S WEST.

WINDS LOOK TO BECOME A LITTLE STRONGER THURSDAY AS RIDGE AXIS
SHIFTS OFF TO THE EAST AND A PACIFIC STORM SYSTEM BEGINS TO TRACK
INTO IDAHO. 700MB WINDS OVER THE CWFA RESPOND...INCREASING TO
45KTS THURSDAY AFTERNOON.

STILL SOME UNCERTAINTY WITH HOW THE SYSTEM WILL MOVE INTO THE
CWFA. GFS CONTINUES TO DISPLAY THE MOST CONSISTENT FORECAST WITH
THE FRONT ENTERING WESTERN WYOMING THURSDAY MORNING AND THEN INTO
CARBON COUNTY BY 00Z THURSDAY AFTERNOON. THE NEW ECMWF
SLOWER...BUT HAS STARTED TO COME IN LINE WITH THE GFS. INSTEAD OF
BEING 24 HOURS SLOWER THAN THE GFS FROM THE 00Z SOLUTION IS NOW
ABOUT 12 HOURS SLOWER ON THE NEW 12Z RUN. ANOTHER CHANGE ON THE
ECMWF IS NOW A CLOSED LOW VS AN OPEN WAVE. ECMWF NOW A BIT MORE
BULLISH ON QPF AS WELL.

WENT AHEAD AND SLIGHTLY INCREASED POPS FOR FRIDAY INTO FRIDAY
NIGHT. DEFINITELY LOOKS LIKE A WIDESPREAD SNOW EVENT TAKING SHAPE
FOR FRIDAY. WILL WAIT FOR A LITTLE MORE CONSISTENCY FROM THE ECMWF
BEFORE UPPING POPS FURTHER.

VERY COLD TEMPERATURES RETURN TO SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE FOR NEXT WEEKEND WITH BOTH THE GFS AND ECMWF SHOWING
700MB TEMPERATURES OF -20 TO -22C OVER THE CWFA. LOOKING AT LOWS
BELOW ZERO TO LOW SINGLE DIGITS PRETTY MUCH EVERYWHERE WITH HIGHS
IN THE TEENS AND LOW 20S SATURDAY INTO SUNDAY.

&&

.AVIATION...18Z TAFS

VFR CONDITIONS EXPECTED NEXT 24 HOURS AS HIGH PRESSURE REMAINS
OVER WESTERN WYOMING. LOOK FOR WINDS TO BEGIN PICKING UP LATE IN
THE PERIOD AS A LEESIDE TROUGH BEGINS TO DEEPEN OVER EASTERN
WYOMING AND WESTERN SOUTH DAKOTA. WINDS LOOK TO BECOME QUITE
STRONG MONDAY AFTERNOON.

&&

.FIRE WEATHER...

FIRE WEATHER CONCERNS WILL CONTINUE TO BE MINIMAL THROUGH THE
MIDDLE PART OF NEXT WEEK WITH AFTERNOON HUMIDITIES GENERALLY ABOVE
25 PERCENT. THERE WILL BE AN INCREASE IN WINDS ACROSS SOUTHEAST
WYOMING ON MONDAY NIGHT THROUGH TUESDAY MORNING...ESPECIALLY IN
THE WIND PRONE AREAS WHERE GUSTS TO 60 MPH WILL BE POSSIBLE.  

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 8 PM MONDAY TO 11 AM TUESDAY FOR WYZ106-
     WYZ110-WYZ116-WYZ117.
NE...NONE.

&&

$$

SHORT TERM/FIRE WEATHER...FINCH
LONG TERM/AVIATION...CLAYCOMB