FXUS65 KCYS 111038 AFDCYS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 338 AM MST THU MAR 11 2010 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT... TODAY...PRIMARY CHALLENGE WILL BE WIND SPEEDS...PARTICULARLY ACROSS WESTERN NEBRASKA. SURFACE THROUGH 700 MB GRADIENTS WILL BE RELATIVELY STRONG AND WITH 500-300 MB QG DOWNWARD MOTION COUPLET THIS AFTERNOON...EXPECT STRONGER WINDS TO BE TRANSPORTED TO THE SURFACE...THUS HAVE ISSUED A WIND ADVISORY FOR ALL OF WESTERN NEBRASKA EXCEPT DAWES COUNTY. EXPECT 40 KNOT 700 MB WINDS TO BE CAPABLE OF BEING TRANSPORTED TO THE SURFACE. ISOLATED TO SCATTERED SNOW SHOWERS WILL DECREASE IN COVERAGE THIS AFTERNOON AS LOW AND MID LEVEL MOISTURE WANES AND THE UPPER TROUGH MOVES FURTHER EAST ACROSS THE MIDWEST STATES. TONIGHT...DRY WITH LACK OF LOW AND MID LEVEL MOISTURE AND LIFT. WINDS WILL SUBSIDE IN THE EVENING WITH SOME DECOUPLING AND RELAXATION OF GRADIENTS. FRIDAY...WARMER DAY ON TAP WITH HIGH TEMPERATURES IN THE 40S TO LOWER 50S WITH 1000-500 MB THICKNESSES NEAR 5490 METERS AND 700 MB TEMPERATURES NEAR -4 CELSIUS. FRIDAY NIGHT...TRANSITORY SHORTWAVE RIDGE MOVES ACROSS WYOMING KEEPING OUR WEATHER DRY. .LONG TERM...SATURDAY THROUGH THURSDAY... A BROAD REX BLOCK DOWNSTREAM WILL IMPACT THE PATTERN PROGRESSION ACROSS THE WRN CONUS THIS WEEKEND...BEFORE THE PATTERN TURNS MORE PROGRESSIVE NEXT WEEK. INITIALLY...AN UPPER RIDGE AXIS WILL BE CENTERED OVER THE INTERMOUNTAIN WEST ON SATURDAY...AS THE REGION IS CAUGHT BETWEEN A LARGE UPPER LOW TO THE EAST...AND AN APPROACHING TROUGH MOVING ONTO THE PACIFIC COAST. SO...SATURDAY WILL BE DRY...WITH TEMPERATURES MODERATING INTO THE 40S...WITH LOW TO MID 50S IN LOWER ELEVATIONS EAST OF THE MOUNTAINS. CLOUDS WILL SLOWLY BE ON THE INCREASE...ESPECIALLY LATE SATURDAY...AS THE WEST COAST TROUGH SPLITS SENDING A PIECE OF ENERGY NORTH...AND AN EVENTUAL CUT-OFF LOW SOUTH OF THE AREA. GIVEN THE PROXIMITY OF THE SYNOPTIC FORCING ASSOCIATED WITH THE SOUTHERN CUT-OFF LOW...HAVE ADDED SOME SLIGHT POPS TO THE MOUNTAINS LATE SATURDAY NIGHT...AND TO ALL LOWER ELEVATIONS WEST OF THE MOUNTAINS ON SUNDAY. THERE WILL NOT BE MUCH MOISTURE TO WORK WITH...SO EXPECT ANY SNOW TO REMAIN VERY LIGHT. THE SOUTHERN STREAM ENERGY WILL DRIFT SOUTH AND BY SUNDAY NIGHT A DRIER AIR MASS WILL BE IN PLACE. BY MONDAY...THE BEGINNING OF THE NEXT QUIET PERIOD WILL BE UPON THE AREA...AS THE NEXT UPPER RIDGE WILL BUILD OVER THE INTERMOUNTAIN WEST. THIS UPPER RIDGE WILL MAINTAIN DRY CONDITIONS MONDAY THROUGH WEDNESDAY NIGHT. TEMPERATURES WILL ALSO BE QUITE MILD AS 700MB TEMPERATURES REACH FREEZING...WHICH WOULD YIELD 60F AT 5 KFT FULLY MIXED. HAVE KEPT TEMPERATURES AROUND THE MEAN ENSEMBLES...BUT EVEN THESE MAY NEED TO BE BUMPED UP SOME...ESPECIALLY IF THESE WARM 700MB TEMPS ARE REALIZED. BOTH THE ECMWF/GFS ARE SUGGESTING THE NEXT SYSTEM WILL MOVE IN NEXT THURSDAY...SO FOR NOW HAVE INTRODUCED CLIMO POPS ACROSS THE AREA. && .AVIATION... INITIALLY...MVFR CIGS/VSBYS CAN BE EXPECTED AT ALL TERMINALS AT LEAST FOR A FEW HOURS THIS MORNING. A GRADUAL RETURN TO VFR IS EXPECTED FROM WEST TO EAST THROUGH THE DAY. MVFR CONDITIONS WILL LINGER THE LONGEST AT NEBRASKA AIRPORTS...WHICH MAY NOT RETURN TO VFR UNTIL LATE THIS AFTERNOON. OTHERWISE...NORTHWEST WINDS RAMP UP TODAY...WITH 25 TO 35 MPH WITH GUSTS AT HIGH AS 45 MPH EXPECTED FOR LOCATIONS EAST OF THE MOUNTAINS. THIS WILL CREATE TURBULENCE ESPECIALLY IN AND AROUND THE MOUNTAINS TODAY. WINDS WILL SUBSIDE SOME OVERNIGHT...BUT ANOTHER WINDY DAY IS EXPECTED ON FRIDAY. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS THROUGH FRIDAY NIGHT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...WIND ADVISORY FROM 7 AM THURSDAY TO 5 PM THURSDAY FOR NEZ003- NEZ019-NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096. && $$ SHORT TERM/AVIATION...RUBIN LONG TERM...HAHN