Issued by NWS Pueblo, CO
000 FXUS65 KPUB 212024 AFDPUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 224 PM MDT TUE OCT 21 2008 .SHORT TERM... (TODAY AND TONIGHT) ...SNOW ACROSS THE CENTRAL MOUNTAINS... ...SEVERE THUNDERSTORMS POSSIBLE ACROSS THE SOUTHEAST PLAINS... ...STRONG GUSTY NORTH WINDS BEHIND THE FRONT TONIGHT THROUGH WEDNESDAY ACROSS THE PLAINS... DIGGING UPPER TROF MOVING THROUGH THE NRN ROCKIES ATTM WILL CONTINUE TO DROP SOUTHWARD ACROSS THE STATE TONIGHT BEFORE CLOSING OFF ACROSS WRN/CEN KS BY WED AFTN. COLD FRONT BEGINNING TO MOVE INTO NRN CO AS OF 19Z...WITH BAND OF SHOWERS/THUNDERSTORMS ALONG/BEHIND THIS BOUNDARY. SFC LOW EXTENDS ACROSS EASTERN CO...WITH SOUTHERLY WINDS ALONG THE KS BORDER ADVECTING UPPER 40S TO LOWER 50S NORTHWARD ALONG THE BORDER. ALREADY SEEING A LINE OF CB DEVELOPING ACROSS WRN BACA COUNTY ALONG SFC TROF AXIS/DEVELOPING DRY LINE. SO FAR CONVECTION HAS BEEN HAVING A DIFFICULT TIME MAINTAINING STRENGTH...BUT THIS SHOULD CHANGE WITH TIME AS BETTER FORCING AND STEEPENING LAPSE RATES ALOFT MOVE IN LATER THIS AFTERNOON. WEST OF THE SFC TROF AXIS...DEW POINTS HAVE BEEN DROPPING ALONG THE EASTERN SLOPES OF THE SE MTS/ADJACENT I-25 CORRIDOR AS SOUTHWEST WINDS HAVE BEEN KICKING IN. WITH TROF DROPPING IN FROM THE NORTHWEST...LAPSE RATES WILL CONTINUE TO STEEPEN DURING THE LATE AFTN/EARLY EVENING. SHOULD START TO SEE CONVECTION DEVELOPING ACROSS THE EASTERN COUNTIES WITH DEEP LAYER SHEARS STRONG ENOUGH TO SUPPORT SUPERCELL DEVELOPMENT. MAIN THREAT WILL BE GUSTY WINDS UP TO 60 MPH AND HAIL UP TO AROUND 1 INCH IN DIAMETER. FRONT IS PROJECTED TO DROP SOUTH OF THE PALMER DIVIDE BY AROUND 00Z WITH STRONGER SURGE DROPPING DOWN BETWEEN 03Z AND 09Z. WIND WILL BE QUITE STRONG BEHIND THE FRONT WITH GUSTS UP TO 50-55 MPH POSSIBLE. CONSIDERED ISSUING A HIGH WIND WARNING FOR STRONG GRADIENT WINDS ACROSS THE PLAINS TONIGHT THROUGH EARLY TOMORROW...BUT TIMING OF FRONT DURING THE OVERNIGHT HOURS ISN`T TERRIBLY CONDUCIVE FOR STRONG WIND GUSTS. APPEARS STRONGEST GUSTS MAY BE JUST TO THE EAST. WILL WAIT FOR THE 18Z NAM BEFORE MAKING THE FINAL CALL. (AFTER QUICK LOOK AT 18Z RUN...HAVE DECIDED TO ISSUE A HIGH WIND WARNING FOR THE EASTERN MOST COUNTIES. TWO ROUNDS OF POTENTIAL HIGH WINDS...ONE WITH FROPA THIS EVENING...AND SECOND WITH GRADIENT WINDS TOMORROW MORNING. THINK WE MAY BE MORE LIKELY TO HIT THE SUSTAINED 40 MPH CRITERIA FOR HIGH WIND RATHER THAN GUST CRITERIA (58 MPH). THIS BLENDS WELL WITH NEIGHBORING OFFICES.) RAIN AND SNOW WILL ALSO BE SPREADING IN BEHIND THE FRONT. FREEZING LEVELS DROP TO AROUND 6KFT BY 06Z...AND DOWN TO AROUND 5KFT BY 12Z. THE PALMER DIVIDE/PIKES PEAK REGION COULD SEE A COUPLE INCHES OF WIND DRIVEN SNOW OVERNIGHT. GROUND IS STILL STARTING OUT RATHER WARM...SO THERE WILL INITIALLY BE SOME MELTING...BUT VISIBILITIES COULD BE QUITE POOR AT TIMES DUE TO ALL THE BLOWING. THIS SYSTEM WRAPS UP QUICKLY ACROSS THE SE PLAINS WITH MOISTURE SHALLOWING OUT BY EARLY WEDNESDAY MORNING. SO SNOW WILL BE BRIEF WHICH SHOULD LIMIT SNOW TOTALS AND KEEP AMOUNTS BELOW ADVISORY CRITERIA. RAW BLUSTERY CHILLY DAY EXPECTED ON THE PLAINS ON WEDNESDAY. WINDS GRADUALLY DECREASE SOME DURING THE AFTERNOON AS SURFACE PRESSURE GRADIENT WEAKENS...BUT IT WILL STILL REMAIN QUITE BREEZY. MAIN PRECIPITATION AXIS/TROWAL SHIFTS EASTWARD BY THE AFTERNOON WITH PRECIPITATION ENDING ACROSS MOST OF THE PLAINS BY AFTERNOON. -KT .LONG TERM... (WEDNESDAY NIGHT THROUGH TUESDAY) ...MAIN CHALLENGES ARE CHANCES FOR PRECIPITATION EAST EARLY...THEN TIMING OF WARM UP... LARGE UPPER LOW OVER CENTRAL NEBRASKA AND KANSAS WILL BE SLOW TO MOVE. LATEST GFS AND NAM HAVE IT WOBBLING...ALLOWING EXTREME EASTERN COLORADO TO BE ON THE FRINGE OF MOISTURE AND IN THE WIND THROUGH THURSDAY EVENING. HAVE KEPT SLIGHT CHANCE POPS IN OUR FAR EASTERN ZONES. WITH GUSTY WINDS OVER 30 MPH...AND A FEW RAIN OR SNOW SHOWERS WITH TEMPERATURES IN THE 40S TO UPPER 20S...IT WILL BE RAW. BOTH MODELS HAVE THE MOISTURE WOBBLING FARTHER WEST DURING THURSDAY. THURSDAY MORNING LOWS SHOULD BE IN THE SINGLE DIGITS TO LOWER TEENS MOUNTAINS AND HIGH VALLEYS TO THE UPPER TEENS AND 20S OVER THE PLAINS. HIGHS ON THURSDAY WILL STRUGGLE INTO THE LOWERS TO MID 50S OVER THE PLAINS WITH MID LEVEL TEMPERATURES ONLY CLIMBING TO A FEW DEGREES CELSIUS EITHER SIDE OF ZERO BY LATE AFTERNOON. HIGHS WILL RANGE FROM THE 30S TO MID 50S OVER THE HIGHEST MOUNTAINS TO HIGH VALLEYS FLOORS. AS THE UPPER LOW PUSHES EAST THURSDAY NIGHT...MOISTURE DECREASES...WINDS DIMINISH...AND MID LEVEL TEMPERATURES INCREASE A FEW DEGREES CELSIUS. AFTER A CHILLY START TO FRIDAY...WITH LOWS IN THE TEENS TO 20S...HIGHS SHOULD REACH THE MID 50S TO LOWER 60S ACROSS THE PLAINS AND HIGH VALLEYS AND 30S TO 40S IN THE MOUNTAINS...WITH MID LEVEL TEMPERATURES AROUND 4 DEGREES WARMER THAN THURSDAY. FROM SATURDAY THROUGH NEXT TUESDAY...WARM RIDGE IN SOUTHWEST US WILL BRING PLEASANT...DRY WEATHER. WITH MID LEVEL TEMPERATURE FROM 5 TO 8 DEGREES CELSIUS...HIGHS SHOULD REACH THE 60S TO LOWER 70S OVER THE PLAINS...50S AND 60S HIGH VALLEYS...AND MAINLY 40S OVER THE MOUNTAINS. -TLM- && .AVIATION...IFR TO LIFR CIGS EXPECTED TO SPREAD ACROSS THE CENTRAL MOUNTAINS LATE THIS AFTN/EVENING AS STRONG SYSTEM DROPS IN FROM THE NORTHWEST. WIDESPREAD MTN OBSCURATIONS EXPECTED ACROSS CHAFFEE/LAKE COUNTY AND ACROSS THE PIKES PEAK REGION AS RAIN AND SNOW SPREADS IN. STRONG COLD FRONT WILL DROP THROUGH THE PLAINS DURING THE EARLY EVENING...WITH GUSTS UP TO 45KTS POSSIBLE FOR THE KCOS AND KPUB TAF SITES. STRONGEST WINDS WILL AFFECT THE KCOS AND KPUB TAF SITES AROUND AND AFTER 03Z. SNOW WILL ALSO SPREAD ACROSS THE PALMER DIVIDE REGION WHERE IFR CIGS POSSIBLE ALONG THE CREST OVERNIGHT. NORTHERLY WINDS WILL PROVIDE MORE OF A DOWNSLOPE COMPONENT FOR KCOS AND KPUB SO CIGS SHOULD STAY IN THE MVFR CATEGORY UNDER BANDS OF SHOWERS. CLEARING CONDITIONS EXPECTED FROM WEST TO EAST ON WEDNESDAY. && .PUB WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 9 PM THIS EVENING TO 1 PM MDT WEDNESDAY FOR COZ096-098-099. && $$ 31/13
