000 FXUS65 KPUB 081746 AFDPUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 1046 AM MST WED FEB 8 2012 && .AVIATION... VFR CONDITIONS ARE EXPECTED OVER THE KALS...KCOS AND KPUB TAF SITES THROUGH THIS EVENING. && .PREV DISCUSSION... /ISSUED 448 AM MST WED FEB 8 2012/ SHORT TERM... (TODAY AND TONIGHT) ..LIGHT SNOW FOR THE MOUNTAINS TONIGHT... HIGH CLOUDS ASSOCIATED WITH THE UPSTREAM TROUGH OVR THE W COAST ARE NOW MOVING OVR CO. ALONG WITH LINGERING STRATUS OVR THE NRN I-25 CORRIDOR...THIS IS ONCE AGAIN KEEPING TEMPS FROM REACHING FORECAST LOWS THIS MORN. HIGH VALLEYS STILL PRETTY COLD...WITH KALS CURRENTLY BELOW ZERO. A FEW FLURRIES OR LIGHT SHSN OVR SRN EL PASO WITH LIGHT SE TO E WINDS PERSISTING OVR THE AREA. PRECIP AND STRATUS SHOULD RETREAT BY MID-MORNING...LEAVING JUST HIGH CLOUDS FOR TODAY...AND SEASONABLY COOL CONDITIONS. SNOW SHOULD START MOVING INTO THE DVD THIS AFTERNOON...AND WILL BECOME STEADY BY THIS EVE. HAVE RAISED POPS TO CATEGORICAL FOR THE DVD OVERNIGHT. PRECIP WILL GENERALLY BE LIGHT AND ATTM NO ADVISORY IS PLANNED...WITH THE PASSES MAYBE PICKING UP AN INCH OR TWO OF SNOW BY THU MORNING. OVR THE PLAINS...ANOTHER CHILLY NIGHT...BUT HIGH CLOUDS WILL AGAIN MODERATE THE LOWS...SO EXPECT LOWS IN THE TEENS FOR MUCH OF THE PLAINS...AND SOME SINGLE DIGITS FOR THE HIGHER ELEVATIONS. 44 LONG TERM... (THURSDAY THROUGH NEXT TUESDAY) UPPER TROUGH SHEARS SOUTHWARD ACROSS THE AREA THURSDAY...PRODUCING JUST ENOUGH UPWARD MOTION TO GENERATE SOME -SHSN ACROSS MAINLY THE MOUNTAINS THROUGH THE DAY. SNOWFALL ACCUMULATION LOOKS LIGHT...WITH ONLY AN INCH OR TWO AT BEST OVER THE SAN JUANS AND SOUTHERN SANGRES. MAX TEMPS WED LOOK SEASONABLE...30/40S LOWER ELEVATIONS...20S/30S MOUNTAINS. TROUGH MOVES SOUTH OF THE AREA THURSDAY NIGHT...LEAVING JUST A FEW FLURRIES ALONG THE NM BORDER. AREA SHOULD STAY BETWEEN WEATHER SYSTEMS ON FRIDAY WITH WEAK UPPER RIDGING OVER THE STATE LEADING TO SLIGHTLY WARMER MAX TEMPS BY AFTERNOON. ATTENTION TURNS NORTHWARD FRIDAY NIGHT/SATURDAY...AS ARCTIC HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS. NOW APPEARS FRONTAL BOUNDARY WILL BACK WESTWARD ACROSS THE PLAINS FRI NIGHT...WITH THE COLD AIR MASS REACHING THE EASTERN MOUNTAINS BY SAT AFTERNOON. SHOULD STILL BE ENOUGH TIME FOR EASTERN MOUNTAIN SLOPES TO WARM SOMEWHAT THROUGH MIDDAY SAT...WHILE AREAS EAST OF I-25 STAY FAIRLY COLD. BY LATE SAT AFTERNOON EXPECT MOST LOCATIONS ALONG AND EAST OF THE MOUNTAINS TO SEE FALLING TEMPS AS COLD AIR DEEPENS. GFS FAIRLY AGGRESSIVE BREAKING OUT LIGHT SNOW IN THE COLD AIR MASS SAT NIGHT...AS WARM ADVECTION ALOFT AND WEAK UPSLOPE COMBINE TO INCREASE UPWARD VERTICAL MOTION. SOME CONCERN ABOUT FREEZING DRIZZLE OVER THE FAR EASTERN PLAINS EARLY SAT NIGHT...THOUGH WITH SOUNDINGS BECOMING SATURATED THROUGH A DEEP LAYER AFTER 06Z...SUSPECT ICE CRYSTALS WILL BE INTRODUCED INTO THE COLUMN WITH A FAIRLY QUICK CHANGE TO LIGHT SNOW OVERNIGHT. ON SUNDAY...MODELS IN GOOD AGREEMENT MOVING UPPER TROUGH THROUGH THE SOUTHERN ROCKIES...WITH TROUGH AXIS EAST OF THE AREA BY LATE SUNDAY NIGHT. LOOKS AT THIS POINT LIKE A WIDESPREAD LIGHT SNOW EVENT FOR MOST OF SOUTHERN COLORADO...AS LOW/MID LEVEL UPSLOPE IS LACKING AS SURFACE AND MID LEVEL CIRCULATION IS SLIGHTLY TOO FAR NORTH FOR DEEP UPSLOPE AND HEAVIER SNOWFALL. CURRENT FORECAST HAS CHANCE POPS WHICH LOOK OK FOR NOW. QUICK BREAK BETWEEN WEATHER SYSTEMS ON MON...BEFORE NEXT AND POTENTIALLY STRONGER UPPER TROUGH APPROACHES LATE TUES/WED. --10 AVIATION...MAIN CONCERN WILL BE MVFR TO IFR CIGS AT KCOS AND KPUB...AS A BAND OF STRATUS PERSISTS OVR N PUEBLO AND SRN EL PASO COUNTIES. THIS SHOULD RETREAT EWD BY 14-15Z AS W WINDS ALOFT BEGIN TO INCREASE. HAVE REMOVED LOW VIS/CIGS FOR KALS THIS MORN...AS IT APPEARS THE INCREASE IN HIGH CLOUDS WILL INHIBIT FG FORMATION THIS MORN. THERE STILL IS A LOW PROBABILITY OF SOME LOW CLOUDS OR FG FORMING VC KALS...BUT IF SO IT SHOULD BE PC AND NOT EXPECTED TO PERSIST THIS MORNING. OVR THE MTS...EXPECT THE DVD TO BECOME OBSCURED TONIGHT AS SN BEGINS TO INCREASE OVERNIGHT. 44 && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$