796
FXUS65 KCYS 161803
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1203 PM MDT WED OCT 16 2013
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 330 AM MDT WED OCT 16 2013
MID AND UPPER LEVEL TROUGH AXIS WILL MOVE SOUTH OF THE CWA BY 15Z.
THE EXTENSIVE MID CLOUD COVER AHEAD OF THE FEATURE OVER THE CWA
FOR MUCH OF NIGHT IS FINALLY DECREASING. MOSTLY CLEAR SKIES WILL
BE OVER THE CWA FOR TODAY AND EARLY TONIGHT AFTER THE TROUGH
PASSAGE. A SHORTWAVE RIDGE ALOFT WILL DEVELOP OVER THE REGION THIS
AFTERNOON AND EVENING AND TEMPERATURES AT 700 MB WILL RISE. THE
SURFACE HIGH CURRENTLY OVER THE CWA WILL CONTINUE TO MOVE SOUTH
AND THE RESULTING SURFACE PRESSURE GRADIENT WILL INCREASE. THE
RESULTING WEATHER FOR TODAY WILL BE WARMER TEMPERATURES AND BRISK
WINDS...ESPECIALLY ALONG AND WEST OF THE LARAMIE RANGE.
THE WEATHER OVER THE CWA WILL CHANGE TO COOL AND WET FROM NORTH
TO SOUTH ON THURSDAY. THE PRECIPITATION WILL GRADUALLY TAPER OFF
AND END FROM NORTH TO SOUTH THURSDAY NIGHT. A SHORTWAVE TROUGH
ENTERING SOUTHERN ALBERTA AND SASKATCHEWAN EARLY THIS MORNING WILL
MOVE ACROSS THE CWA LATE TONIGHT AND THURSDAY MORNING. THE FEATURE
WILL BE FOLLOWED BY A FAST NORTHERLY FLOW ALOFT. THE CYCLONIC SIDE
OF THE 300 MB JET WITHIN THAT FLOW WILL MOVE SLOWLY FROM WEST TO
EAST OVER THE CWA THURSDAY AFTERNOON AND THURSDAY NIGHT. THE
ASSOCIATED SURFACE COLD FRONT WAS CURRENTLY JUST NORTH OF THE U.S.
AND CANADIAN BORDER AND WILL MOVE ACROSS THE CWA TONIGHT.
PRECIPITATION WAS FALLING OVER SOUTHERN ALBERTA BEHIND THE FRONT.
RAIN AND SNOW WILL SPREAD INTO THE FAR NORTH PART OF THE CWA LATE
TONIGHT AND THEN OVER THE ENTIRE CWA BY THURSDAY AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT AND SHORTWAVE TROUGH WILL
CHANGE THE PRECIPITATION TO ALL SNOW OVER THE CWA BY THURSDAY
EVENING. AT THIS TIME...THE MORE SIGNIFICANT SNOWFALL SHOULD FALL
OVER SOUTHERN WYOMING...INCLUDING K82V...KCYS AND KLAR...THURSDAY
NIGHT. THE ATMOSPHERE WILL BE SATURATED PER FORECAST RAOBS...
ESPECIALLY OVER THE SOUTHERN PART OF THE CWA THURSDAY AFTERNOON
AND THURSDAY NIGHT. THE JET DYNAMICS...WEAK MID LEVEL FRONTOGENESIS
AND WEAK Q-G AND SURFACE FORCING WILL PROVIDE THE LIFT FOR THE
FAIRLY BRIEF PRECIPITATION EVENT. SNOW AMOUNTS WILL BE CLOSE TO
ADVISORY LEVELS OVER LARAMIE AND SOUTHERN ALBANY COUNTIES BY 12Z
FRIDAY.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 AM MDT WED OCT 16 2013
UPPER TROF AXIS SHOULD BE PRETTY MUCH PAST THE CWA FRIDAY MORNING
WITH A FEW LINGERING FLURRIES STILL POSSIBLE FRIDAY MORNING MAINLY
NEAR THE COLORADO BORDER. OTHERWISE MAINLY DRY AND MILD WEATHER
THEN EXPECTED THROUGH THE WEEKEND INTO EARLY NEXT WEEK AS THE CWA
REMAINS UNDER A NW FLOW ALOFT. CLIPPER-LIKE SYSTEM MAY PASS ACROSS
THE REGION SUNDAY NIGHT INTO EARLY MONDAY AND BRING A FEW SHOWERS
TO MAINLY THE NORTHWEST PART OF THE CWA THEN. ECMWF MORE ROBUST
WITH THIS SYSTEM THAN THE GFS AS WELL AS SLOWER AS IT IS MORE
AMPLIFIED WITH THE BROAD SCALE UPPER TROF OVER THE GREAT LAKES
REGION. MAY NEED TO NUDGE POPS UP SOME FOR THIS TIME IF MORE
CONSISTENCY IS DEMONSTRATED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1152 AM MDT WED OCT 16 2013
THROUGH 06Z...VFR. GUSTY WINDS DECREASING AFTER 00Z.
AFTER 06Z...FAST MOVING SHORTWAVE TROUGH ALOFT MOVING SOUTHEAST
ALONG WITH QUICK MOVING CANADIAN ORIGIN COLD FRONT...SHIFTING
WINDS TO NORTH AND NORTHWEST AND INCREASING MARKEDLY WITH WIND
GUSTS AFTER COLD FRONTAL PASSAGE.
AREAS OF LOW CLOUDS...FOG AND SNOW DEVELOPING BEHIND COLD FRONT...
ESPECIALLY AT ALLIANCE AND CHADRON...WHERE IFR WILL DEVELOP AFTER
13Z THURSDAY. MVFR IN LOW CLOUDS AT CHEYENNE AND SCOTTSBLUFF AFTER
16Z THURSDAY. AT RAWLINS AND LARAMIE...VFR PREVAILS WITH CEILINGS
LOWERING TO 3500 TO 5000 FEET AGL.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MDT WED OCT 16 2013
FIRE WEATHER CONCERNS WILL BE MINIMAL OVER THE CWA THROUGH EARLY
NEXT WEEK. TODAY WILL BE WARMER WITH NO PRECIPITATION. SOUTHWEST
WINDS WILL GUST AS HIGH AS 35 MPH IN AREAS ALONG AND WEST OF THE
LARAMIE RANGE FROM MID MORNING THROUGH SUNSET.
A COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT AND WILL BRING
COOLER TEMPERATURES AND RAIN AND SNOW TO THE CWA FOR THURSDAY
AND THURSDAY NIGHT.
TEMPERATURES WILL WARM TO NEAR NORMAL OVER THE WEEKEND AND
CONTINUE THROUGH EARLY NEXT WEEK. LITTLE OR NO PRECIPITATION AND
BREEZY CONDITIONS ARE EXPECTED.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...WEILAND
LONG TERM...RE
AVIATION...RUBIN
FIRE WEATHER...WEILAND