000 FXUS65 KPUB 121046 AFDPUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 346 AM MST TUE FEB 12 2008 .SHORT TERM... (TODAY AND TONIGHT) ...MAIN SHORT TERM CONCERN INCLUDES TEMPERATURES AND WINDS... CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATED STRONG NORTH TO NORTHWEST FLOW ALOFT AS 120+ KT NORTH/SOUTH JET CORE TRANSLATES ACROSS THE ROCKIES. TODAY AND TONIGHT...FLOW ALOFT MODERATES AND BECOMES MORE WEST TO NORTHWEST AS JET CORE ACROSS THE ROCKIES TRANSLATES EAST INTO THE UPPER MIDWEST AND NORTHERN HIGH PLAINS THROUGH TONIGHT. TEMPERATURES ALOFT MODERATE WITH HEIGHTS BUILDING FROM WEST TO EAST ACROSS THE STATE AND EXPECT THE GUSTY NORTHWEST WINDS ACROSS THE HIGHER TERRAIN TO SLOWLY DIMINISH THROUGH THE DAY. MODELS KEEPING SHALLOW MOISTURE LAYER IN PLACE ACROSS THE NORTHERN AND CENTRAL MTS WITH DECENT OROGRAPHIC FLOW...THOUGH WITH POOR LAPSE RATES NOT EXPECTING MUCH MORE THAN A FEW FLURRIES. SOUNDINGS INDICATING GUSTY NORTHWEST WINDS OF 15 TO 25 MPH MIXING DOWN ACROSS THE EASTERN PLAINS LATE THIS MORNING HELPING TO WARM TEMPS INTO THE AFTERNOON...THOUGH WITH BOUTS OF CLOUDS ASSOCIATED WITH PASSING JET CORE...HAVE KEPT STAYED CLOSE TO MAV GUIDANCE FOR TEMPS...SAVE THE SAN LUIS VALLEY WHERE STRONG INVERSIONS LOOK TO PERSIST. .LONG TERM... (WEDNESDAY THROUGH MONDAY) ...WARM AND BREEZY/WINDY BEFORE THE STORM ON WEDNESDAY... ...POTENTIAL HIGH IMPACT WINTER WEATHER WEDNESDAY NIGHT-THURSDAY EVENING... WEDNESDAY...GENERALLY SHORT RANGE MODELS IN FAIR AGREEMENT WITH THE SYNOPTIC SCALE PATTERN WITH RELATIVELY VIGOROUS WEST-SOUTHWEST FLOW OVER MUCH OF CO AHEAD OF THE DIGGING WEATHER SYSTEM OVER THE GREAT BASIN. SHOULD SEE A RELATIVELY MILD/WARM DAY...BUT AT THE EXPENSE OF BREEZY/WINDY CONDITIONS. SURFACE CYCLOGENESIS IS FORECAST ACROSS NORTHEAST CO WITH LEE SIDE TROUGHING TRAILING SOUTHWARD ACROSS THE HIGH CO PLAINS. 45-65KT AT H7 ALONG WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES COULD PROMOTE BREEZY/WINDY CONDITIONS ACROSS MUCH OF SOUTHERN CO. THE ONLY CHALLENGE WOULD BE A BKN-OVC CS/CI MOUNTAIN WAVE CLOUD ALONG THE CO FRONT RANGE THAT COULD TEMPER THE TEMPERATURES IF THE WINDS DONT PICK UP. IF BREEZY/WINDY CONDITIONS DEVELOP IN THE SAN LUIS VALLEY...THEN TEMPERATURES COULD GET INTO THE 30S APPROACHING 40F. CRITICAL FIRE WEATHER CONCERNS COULD BE INCREASING ACROSS THE FAR SOUTHEASTERN CO PLAINS...BUT MOST AREAS DID RECEIVE SNOWFALL LAST WEEK IN SOME CASES AROUND 12 INCHES. THE BLM FIRE WEATHER FUELS PAGE IS SIGNIFICANTLY OLD ON THE INTERNET...SO THAT IS NO HELP. DAYTIME MINIMUM HUMIDITY VALUES WILL DROP BELOW 20%...BUT WIND SPEEDS MIGHT NOT REACH CRITICAL LEVELS. WILL HOLD OFF ISSUING ANY FIRE WEATHER HEADLINES AND ADDRESS IN HAZARDOUS WEATHER OUTLOOK. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...THESE FORECAST PERIODS CONTINUE TO BE TARGETED FOR A WEATHER SYSTEM MOVING THROUGH OR JUST TO THE WEST OF CO. CERTAINLY A COMPLEX WEATHER PATTERN WHEN POTENTIAL LOW PRESSURE SYSTEMS DEEPEN AND DROP SOUTH- SOUTHWESTWARD. THE 00Z/12 AND 06Z12 NAM-WRF IS THE WEAKEST WITH THE SOLUTION...WHILE THE 00Z/12 ECMWF IS MUCH STRONGER WITH THE CLOSED LOW. THE 00Z/12 GFS IS SOMEWHERE IN-BETWEEN. GFS AND ECMWF HAVE BEEN DOING BETTER THAN THE NAM-WRF...SO WILL LEAN HEAVILY TOWARDS THE GFS-ECMWF BLEND. A CLOSED LOW WILL LIKELY BE DEVELOPING AROUND THE FOUR CORNERS AREA LATE WEDNESDAY NIGHT AND THEN DROP SOUTHWARD INTO NM DURING THURSDAY- THURSDAY EVENING. MEANWHILE...A COLD FRONT IS FORECAST TO RACE THROUGH EASTERN CO. AGAIN...THIS PUTS SOUTHERN CO IN-BETWEEN TWO SYSTEMS. THE POTENTIALLY GREATEST SYNOPTIC SCALE ASCENT...PER MODEL KINEMATICS...COULD BE ACROSS CENTRAL AND SOUTH CENTRAL CO DURING WEDNESDAY NIGHT INTO THURSDAY AFTERNOON. -15C LEVEL DROPS BELOW 500MB NEAR THE CLOSED LOW AND IN THE TROUGH OVERHEAD ALONG WITH ADEQUATE MODEL PROJECTED UPWARD VERTICAL MOTION IN THIS LAYER. SURFACE TEMPERATURES ACROSS THE MOUNTAINS AND HIGH VALLEYS SHOULD BE IN THE SINGLE DIGITS TO 20S PROMOTING 20-1 TO 30-1 SNOW RATIOS. ALSO...KIND OF A MIDLEVEL COL SETTING UP OVER THE MOUNTAINS...WHICH COULD HELP WITH DEFORMATION BANDING PRECIPITATION ACROSS MUCH OF SOUTH CENTRAL CO. FURTHERMORE...AN ISENTROPIC ASCENT AREA DEVELOPS JUST SOUTH OF THE COL OVER NORTHERN NM AND THESE BANDS OF PRECIPITATION COULD MIGRATE NORTHWARD ACROSS THE NM/CO BORDER INTO THE SOUTHERN SAN LUIS VALLEY/SOUTHERN SANGRE DE CRISTO MOUNTAINS BY THURSDAY AFTERNOON. THE POTENTIAL FOR 12-24 HOUR WARNING CRITERIA COULD BE THE EASTERN SAN JUAN MOUNTAINS... SAN LUIS VALLEY...SANGRE DE CRISTO MOUNTAINS...WET MOUNTAINS/VALLEY... AND SOUTHERN FOOTHILLS...SO WILL GO WITH A WINTER STORM WATCH FOR WEDNESDAY EVENING THROUGH THURSDAY EVENING. ADVISORY NUMBERS COULD OCCUR AROUND THE WARNING AREA...BUT TOUGH CALL. FOR TELLER...EL PASO AND PUEBLO COUNTIES...A VERY DIFFICULT CALL AS THE CLOSE LOW WILL LIKELY BE TOO FAR WEST...HOWEVER THE COLD FRONT RACING DOWN THE PLAINS WILL BE A PLAYER. THE PALMER DIVIDE COULD SEE ADVISORY NUMBERS BY LATE WEDNESDAY NIGHT INTO THURSDAY. POTENTIAL FOR QPF/SNOW AMOUNT SHADOW TO DEVELOP ACROSS SOUTHERN EL PASO AND NORTHERN PUEBLO COUNTIES GIVEN THE STIFF NORTHERLY WIND AND LACK OF STRONG MIDLEVEL UPWARD VERTICAL MOTION...HOWEVER THERE WILL BE SOME LOW LEVEL FRONTOGENETICAL FORCING TO PRODUCE PRECIPITATION. OVERALL...ALWAYS A VERY TOUGH CALL WITH THIS STYLE OF STORM TRACK. IF IT IS A LITTLE FURTHER WEST...THEN NOT MUCH SNOW. IF IT IS A LITTLE FURTHER EAST...THEN SOUTH CENTRAL CO GETS SLAMMED WITH SNOW. THIS IS WHAT A WINTER STORM WATCH IS FOR AND SHOULD BE STRESSED. FRIDAY THROUGH MONDAY...NO CHANGES TO CURRENT FORECAST. METZE && .AVIATION... VFR CONDITIONS EXPECTED ACROSS THE REGION WITH ISOLATED SNOW SHOWERS CONFINED TO THE NORTHERN AND CENTRAL MTS. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR COZ078>080-087-088. WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR COZ064>075. && $$ 23/17