Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 02/17/12


AREA FORECAST DISCUSSION
NWS TAUNTON MA
1004 PM EST THU FEB 16 2012 .SYNOPSIS... LOW PRESSURE OVER SOUTHEAST CANADA WILL MOVE NORTHEAST TONIGHT WITH ITS ATTENDING COLD FRONT MOVING ACROSS SOUTHERN NEW ENGLAND LATE TONIGHT AND FRIDAY MORNING. RAIN SHOWERS WILL ACCOMPANY THE FRONTAL PASSAGE WITH SOME SNOW SHOWERS POSSIBLE ACROSS THE HIGHER TERRAIN. DRY AND COOLER WEATHER OVERSPREADS THE REGION FRIDAY AFTERNOON INTO SATURDAY. A WEAK TROUGH SATURDAY NIGHT MAY BRING SCATTERED SNOW SHOWERS TO THE AREA. AN OCEAN STORM MAY BRING A PERIOD OF RAIN...SNOW AND WIND TO THE SOUTH COAST SUNDAY NIGHT INTO MONDAY MORNING. DRY BUT COOLER WEATHER IS EXPECTED EARLY NEXT WEEK...WITH A MODERATING TREND RETURNING BY MID WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 10 PM UPDATE... MOST OF THE SHOWERS THIS EVENING ARE CONCENTRATED ALONG THE S COAST AND E NEW ENG ASSOCD WITH MODEST MID LEVEL JET. FURTHER NW IN THE INTERIOR...THE AREAL COVERAGE OF PRECIP HAS DECREASED CONSIDERABLY AND MANY AREAS ARE NOW DRY. RUC13 SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT PRECIP...FOCUSING THE SHOWERS ACROSS SE HALF OF NEW ENG NEXT SEVERAL HOURS. REGIONAL RADAR INDICATES PRECIP INCREASING EAST OF THE GT LAKES AND INTO CENTRAL NY AHEAD OF THE COLD FRONT. AS THE FRONT APPROACHES FROM THE WEST...A FEW RAIN/SNOW SHOWERS WILL LIKELY MOVE BACK IN ACROSS W ZONES LATE TONIGHT. LITTLE OR NO ADDITIONAL ACCUM EXPECTED. ADJUSTED POPS TO REFLECT CURRENT RADAR TRENDS AND EXPECTED AREAL COVERAGE OF PRECIP. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY... 12Z MODELS HAVE TRENDED SLOWER WITH THE DEPARTURE OF THE MID LEVEL TROF AND ATTENDING COLD FRONT. ALSO MODELS INDICATE MODEST MID LEVEL LIFT AND DEEP LAYER MOISTURE OVER THE AREA FRI MORNING IN ADVANCE OF APPROACHING SHORT WAVE MOVING ACROSS THE EASTERN GREAT LAKES. THEREFORE SHOWERS WILL LIKELY BE WIDESPREAD FRI MORNING ESPECIALLY OVER EASTERN MA AND RI. NAM ALSO OFFERING STEEPENING MID LEVEL LAPSE RATES AHEAD OF THE FRONT AND APPROACHING SHORT WAVE. THE 12Z ECMWF AND GFS ARE NOT AS ROBUST. THEREFORE NOT EXPECTING ANY ELEVATED CONVECTION BUT COULD BE ENOUGH INSTABILITY ALOFT TO ENHANCE SHOWERS IN COVERAGE AND INTENSITY ESPECIALLY OVER EASTERN MA DURING THE MORNING AND INTO THE MIDDAY OVER THE CAPE AND NANTUCKET. FRONTAL PASSAGE WILL OCCUR DURING THE EARLY AFTERNOON /MID TO LATE AFTN FOR CAPE COD AND NANTUCKET/ WITH CLEARING FROM WEST TO EAST. COLDER AIR LAGS WELL BEHIND THE FRONT SO EXPECTING ANOTHER DAY OF ABOVE NORMAL TEMPS. WNW WINDS WILL INCREASE BEHIND THE FRONT. FRI NIGHT... QUIET/DRY WEATHER WITH SHORT WAVE RIDGING OVER THE AREA. MODEST COLD AIR ADVECTION WILL RESULT IN A SEASONABLY COLD NIGHT. && .LONG TERM /SATURDAY THROUGH THURSDAY/... OVERVIEW... THE BIG STORY FOR THIS PERIOD IS THE POSSIBLE COASTAL STORM DEVELOPING AROUND THE MID ATLC COAST THIS WEEKEND AND ITS TRACK ACROSS THE WESTERN ATLC. TODAY/S 12Z MODEL SUITE ALL APPEAR TO BE IN GOOD AGREEMENT IN KEEPING THE NORTHERN AND SOUTHERN STREAMS SEPARATE...WITH HIGH PRESSURE HOLDING THE DEVELOPING LOW AT BAY AT LEAST FOR MOST OF THE REGION. H5 PATTERN REMAINS PROGRESSIVE...WITH A POSITIVELY TILTED SHORT WAVE TROUGH ASSOCIATED WITH THIS LOW. WILL STILL NEED TO MONITOR FUTURE MODEL SOLUTIONS...BUT CONFIDENCE IS INCREASING FOR LESSER EFFECTS FROM THIS SYSTEM. BEYOND THIS...MODELS STILL SHOWING A FAST FLOW ALOFT...WITH TIMING ISSUES EARLY NEXT WEEK THROUGH THE END OF THE PERIOD. HOWEVER...THERE IS GOOD CONTINUITY OF A WARMING TREND RETURNING BY THE MIDDLE OF NEXT WEEK AFTER SOME NEAR NORMAL TEMPERATURES FOR MONDAY AND TUESDAY. SATURDAY...EXPECT DRY CONDITIONS BUT INCREASING CLOUDS DURING THE DAY AS WEAK CLIPPER TYPE SHORT WAVE WORKS ACROSS IN THE NORTHERN STREAM OUT OF THE GREAT LAKES. RATHER MOISTURE STARVED...SO NOT EXPECT A WHOLE LOT PRECIP WITH THIS FEATURE. HAVE MAINLY SLIGHT CHANCE POPS GOING. SOME MOISTURE FROM THE DEVELOPING MID ATLC COASTAL LOW MAY START TO WORK INTO THIS WEAKER LOW...BUT WILL WEAKEN EVEN FURTHER SAT NIGHT. DAYTIME HIGHS WILL MAINLY BE IN THE 40S. SUNDAY-SUNDAY NIGHT...CLOUD SHIELD WILL REMAIN ACROSS THE REGION AS COASTAL LOW TAKES SHAPE AND MOVES E-NE. INTERESTING TO NOTE THAT HPC FEELS THE 12Z OP ECMWF RUN HAS SOME INITIALIZATION ISSUES WHICH GIVES LESS CREDENCE TO ITS SOLUTION...THOUGH APPEARS TO BE IN PRETTY GOOD AGREEMENT WITH THE CANADIAN GGEM. IN ANY EVENT...ALL MODELS TEND TO KEEP THE MAJORITY OF PRECIP WELL S OF THE REGION. LEANED TOWARD A BLEND OF HPC AND GFS FOR THIS PORTION OF THE FORECAST. THE GFS REMAINS THE FURTHEST N WITH THE PRECIP SHIELD...AND CAN NOT RULE THIS OUT FOR NOW. MOS GUIDANCE DID GIVE LIKELY POPS INTO THE OUTER CAPE AND NANTUCKET...BUT FEEL THIS IS STILL TOO HIGH CONSIDERING THE CONSISTENCE OF EACH MODEL RUN KEEPING THE SYSTEM FURTHER AND FURTHER S. SO...HAVE KEPT THE HIGHEST POPS GOING FOR THE S COAST...CAPE COD AND THE ISLANDS FROM SUNDAY AFTERNOON THROUGH THE PRE DAWN HOURS MONDAY. WILL SEE LIGHT PRECIP...MAINLY IN THE FORM OF RAIN DURING SUNDAY WITH SOME POSSIBLE LIGHT SNOW SUN NIGHT AS THE WESTERN EDGE OF THE PRECIP STARTS TO PUSH OFFSHORE. SOME DIFFERENCES WITH INCREASING PRES GRADIENT AND NE-N WINDS SUN NIGHT AS LOW DEEPENS OFFSHORE WITH THE GFS RAPIDLY DEEPENING THIS LOW. HAVE MENTIONED POSSIBLE GUSTS UP TO 25-30 KT MAINLY ALONG THE E COAST. MONDAY INTO TUESDAY...LARGE HIGH PRES BUILDS OUT OF THE MIDWEST AND GREAT LAKES TOWARD THE EASTERN SEABOARD DURING THIS TIMEFRAME. WILL SEE BLUSTERY N-NW WINDS WITH THE CONTINUED PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND THE STRONG HIGH. WILL BE A COOL DAY ON MONDAY WITH HIGHS MAINLY IN THE 30S THOUGH IT WILL FEEL COOLER DUE TO THE WINDS. WITH THE QUICK UPPER LEVEL FLOW IN PLACE...THE HIGH RIDGE WILL BUILD ACROSS THE REGION DURING TUESDAY...SO WILL START TO SEE MODERATING TREND RETURN ONCE AGAIN TO THE REGION. HIGHS FORECAST TO REACH INTO THE LOWER-MID 40S FOR MOST AREAS. WEDNESDAY-THURSDAY...AS FAST UPPER FLOW CONTINUES ACROSS THE LOWER 48...MODEL SUITE HAVING A DIFFICULT TIME WITH THE TIMING AND TRACK OF INDIVIDUAL SHORT WAVES ALOFT AS WELL AS SURFACE FEATURES. AT THIS POINT...DOES APPEAR A WARM FRONT WILL TRY TO PUSH N OF THE REGION SOMETIME WEDNESDAY...THEN A COLD FRONT WILL PUSH THROUGH SOMETIME THURSDAY. CONTINUED TO CARRY CHANCE POPS FOR MOST OF THIS TIMEFRAME...THOUGH TIMING IS STILL IN QUESTION. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT TONIGHT...MODERATE TO HIGH CONFIDENCE IN TAFS. MVFR-IFR CIGS/VSBYS LIKELY MOST AREAS...WITH SHOWERS MOSTLY CONCENTRATED EASTERN NEW ENG. FRIDAY...MODERATE TO HIGH CONFIDENCE IN THE TAFS. MVFR/IFR CONDITIONS LIKELY IN -SHRA MOST AREAS...-SHSN POSSIBLE NW CT/MA AND SOUTHWEST NH...BUT IMPROVING TO VFR IN THE AFTERNOON FROM WEST TO EAST. WNW MAY GUSTS UP TO 25 KT LATER IN THE DAY. FRIDAY NIGHT... HIGH CONFIDENCE FOR VFR ALONG WITH GUSTY WNW WIND OVER CAPE COD AND THE ISLANDS. KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF. VFR CIGS AND VSBYS INTO THIS EVENING IN LIGHT RAIN SHOWERS. MVFR LIKELY FROM 03Z-04Z ONWARD IN LIGHT RAIN SHOWERS. LOW PROBABILITY OF BRIEF IFR 09Z-15Z FRI BUT MVFR MORE LIKELY IN LINGERING SHOWERS. IMPROVING TO VFR AROUND MIDDAY ALONG WITH A WIND SHIFT TO THE WEST. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...MODERATE CONFIDENCE FOR VFR CONDITIONS. MAY SEE BRIEF MVFR CIGS/VSBYS ALONG S COAST LATE SAT NIGHT IN ANY LIGHT SPOTTY RAIN AND/OR SNOW. SUNDAY...LOW TO MODERATE CONFIDENCE. CONDITIONS REMAIN DEPENDENT UPON HOW FAR N COASTAL STORM TRACKS TO REGION. AT THIS POINT... EXPECT MAINLY VFR CONDITIONS NEAR AND N OF THE MASS PIKE. S OF THE MASS PIKE...MAY SEE PERIODS OF MVFR CIGS VSBYS IN RAIN AND/OR SNOW WITH THE BEST CHANCE ALONG THE S COAST. ALSO...POTENTIAL FOR NE WIND GUSTS UP TO 25-30 KT ALONG THE S COAST. MONDAY...MODERATE TO HIGH CONFIDENCE FOR VFR CONDITIONS. N-NW WIND GUSTS UP TO 25-30 KT...DIMINISHING EARLY MON NIGHT. TUESDAY...MODERATE TO HIGH CONFIDENCE FOR VFR CONDITIONS. && .MARINE... TONIGHT... SOUTH WINDS 10-15 KT AHEAD OF APPROACHING FRONT. NUMEROUS SHOWERS. FRI... NUMEROUS SHOWERS IN THE MORNING FOLLOWED BY A FRONTAL PASSAGE IN THE AFTERNOON. WIND SHIFT FROM S TO WNW BEHIND THE FRONT. POST FRONTAL WINDS 15-20 KT. SHOWERS SHOULD BE WELL OFFSHORE BY LATE IN THE DAY. FRI NIGHT... WNW WINDS 15-20 KT WITH GUSTS UP TO 25 KT POSSIBLE. AIRMASS DOESN/T APPEAR COLD ENOUGH TO SUPPORT FREEZING SPRAY. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...EXPECT W WIND GUSTS AT 25-30 KT THROUGH SAT EVENING... THEN SHOULD DIMINISH. SEAS REMAINING AOA 5 FT THROUGH SAT ON THE OUTER WATERS...BUT FORECAST TO SUBSIDE SAT NIGHT. SUNDAY...N-NE WINDS PICK UP TO AT LEAST SMALL CRAFT CRITERIA SUNDAY AFTERNOON. POTENTIAL FOR AT LEAST SCA NE WINDS AS A COASTAL STORM TRACKS S OF THE WATERS. NE GALES POSSIBLE IF STORM TRACKS FURTHER N. MONDAY...SCA NW WINDS LIKELY WITH A LOW PROB OF GALE FORCE GUSTS. TUESDAY...W WINDS REMAIN BELOW SMALL CRAFT CRITERIA...THEN BACK TO SW. LOW PROB OF 25 KT GUSTS ON THE OUTER WATERS TUE NIGHT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...NOCERA/EVT NEAR TERM...KJC SHORT TERM...NOCERA LONG TERM...EVT AVIATION...KJC/NOCERA/EVT MARINE...KJC/NOCERA/EVT
AREA FORECAST DISCUSSION
NWS ALBANY NY
1238 AM EST WED FEB 15 2012 .SYNOPSIS... SEVERAL WEAK UPPER LEVEL DISTURBANCES WILL MOVE ACROSS THE REGION OVERNIGHT THROUGH WEDNESDAY...BRINGING MAINLY CLOUDY SKIES...ALONG WITH THE CHANCE OF SOME VERY LIGHT SNOW OR RAIN SHOWERS. ANOTHER STORM SYSTEM APPROACHING FROM THE SOUTHWEST WILL BRING ADDITIONAL PRECIPITATION TO THE REGION THURSDAY INTO THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 940 PM EST...LATEST 00Z NAM MODEL GUIDANCE AND 3KM HRRR IS SHOWING LITTLE PRECIP ACROSS OUR AREA TONIGHT. CURRENTLY...THE BEST RADAR RETURNS ARE SEEN ON THE KBGM RADAR ACROSS NORTHEAST PA AND THE SOUTHWESTERN CATSKILLS. AS PREVIOUSLY MENTIONED...THE 00Z KALY SOUNDING SHOWS VERY DRY AIR AT LOW LEVELS...AND WEAK FORCING DUE TO A SHORTWAVE ALOFT WILL ONLY ALLOW FOR WIDELY SCT/ISOLD SHOWERS. WHILE THE BOUNDARY LAYER IS WARM ENOUGH FOR RAIN IN SOUTHERN PARTS OF THE AREA RIGHT NOW...TEMPS SHOULD COOL OFF ENOUGH TO ALLOW P-TYPE TO BE SNOW ACROSS THE ENTIRE AREA AFTER MIDNIGHT. HOWEVER...QPF WILL ONLY BE A HUNDREDTH OR TWO AT MOST...WITH THE BEST CHC OF SEEING THIS OVER THE HIGHER TERRAIN OF THE CATSKILLS AND PERHAPS THE SOUTHERN ADIRONDACKS AS WELL. EVEN THOUGH TEMPS IN SOME AREAS HAVE DROPPED OFF THIS EVENING...THICKER CLOUD COVER SHOULD SLOW THE RATE OF FALLING TEMPS AND OUR PROJECTED MIN TEMPS STILL LOOK GOOD...WITH MID TO UPPER 20S IN MOST AREAS...TO AROUND 30 FOR THE CAPITAL REGION AND MID HUDSON VALLEY. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... WED-WED NT...ONE FINAL SHORTWAVE...AND AREA OF WEAK SFC CONVERGENCE WILL MOVE ACROSS DURING THE MORNING/EARLY AFTERNOON HOURS...WITH ISOLATED TO SCATTERED LIGHT SHOWERS OF RAIN OR WET SNOW POSSIBLE. IN ITS WAKE...EXPECT CLOUDS TO LINGER INTO THE EARLY EVENING HOURS. THEN...EXPECT CLEARING TO DEVELOP FROM SW TO NE LATER WED EVE INTO THE OVERNIGHT HOURS. LIGHT WINDS...AND CLEARING SKIES SHOULD ALLOW TEMPS TO FALL TO LOWER LEVELS THAN TONIGHT...WITH MINS GENERALLY EXPECTED TO REACH CLOSE TO THE COOLER MAV MOS...GENERALLY 20-25 IN MOST VALLEYS...AND TEENS ACROSS THE NORTH COUNTRY AND HIGHER ELEVATIONS ACROSS WESTERN NEW ENGLAND. THU-THU NT...NEXT FEATURE IS EXPECTED TO APPROACH FROM THE SOUTHWEST/WEST DURING THURSDAY...AS ONE WEAK LOW TRACKS INTO AND ACROSS SE CANADA...WITH AN EVEN WEAKER SFC LOW DEVELOPING OFF THE MID ATLANTIC COAST AND TRACKING ENE. MODELS HAVE DECREASED OVERALL QPF CONSIDERABLY ACROSS THE REGION...WITH GENERALLY 0.15-0.25 EXPECTED...PERHAPS LOCALLY HIGHER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS/MOHAWK VALLEY REGION. P-TYPE MAY INITIALLY BE RAIN IN VALLEYS...AND A RAIN/SNOW MIX ACROSS HIGHER ELEVATIONS EARLY THU AFTERNOON...TRANSITIONING TO MAINLY WET SNOW BY THU EVE INTO THE OVERNIGHT HOURS. GIVEN THE LIGHTER QPF...SNOWFALL ACCUMS SHOULD ALSO BE LESS...PERHAPS 1-3 INCHES ACROSS PORTIONS OF THE WESTERN ADIRONDACKS/MOHAWK VALLEY...AND GENERALLY AN INCH OR LESS ELSEWHERE...WITH MOST ACCUMS IN VALLEYS OCCURRING ON COLDER SURFACES. ONE THING TO WATCH FOR WILL BE HOW QUICKLY THE PRECIP DEVELOPS THU AFTERNOON...AS WE HAVE SEEN WITH OTHER EVENTS THIS SEASON THUS FAR...THIS COULD CHANGE OVER TO SNOW FAIRLY QUICKLY IF A DECENT BURST OF WARM ADVECTION/LIFT PASSES THROUGH...WHICH COULD PRODUCE MINOR...SLUSHY ACCUMS EVEN ON ROAD SURFACES THU EVE. HAVE GENERALLY INDICATED THU MAXES IN THE UPPER 30S TO LOWER 40S IN VALLEYS AND MID 30S ACROSS HIGHER ELEVATIONS...WITH FAIRLY UNIFORM MINS IN THE UPPER 20S TO LOWER 30S FOR THU NT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MAINLY QUITE WEATHER IS EXPECTED DURING THE LONG TERM PERIOD WITH TEMPS STILL WELL ABOVE NORMAL FRIDAY INTO SATURDAY TRENDING TO MORE SEASONABLE LEVELS SATURDAY NIGHT THROUGH TUESDAY. ON FRIDAY THE PRIMARY LOW LIFTS NORTHEAST THROUGH QUEBEC WHILE THE SECONDARY LOW LIFTS NORTHEAST FROM WELL SOUTH OF LONG ISLAND TO SOUTH OF NOVA SCOTIA. STILL EXPECT SOME LINGERING RAIN AND SNOW SHOWERS ACROSS THE NORTHERN THIRD OF THE AREA MAINLY FOR AREAS FROM THE NORTH SIDE OF THE MOHAWK VALLEY TO SOUTHERN VERMONT AND POINTS NORTH. THERE WILL ALSO BE SOME LAKE ENHANCED SNOW AS A 280 DEG WIND FLOW OFF LAKE ONTARIO WILL RESULT IN A LAKE ENHANCED BAND REACHING NORTHERN HERKIMER AND FAR NORTHWEST HAMILTON COUNTY. TEMPS ARE EXPECTED TO BE IN THE MID 30S TO MID 40S. FRIDAY NIGHT AND SATURDAY THE LAKE EFFECT IS EXPECTED TO CONTINUE ACROSS NORTHERN HERKIMER COUNTY AND EXTREME NORTHWEST HAMILTON COUNTY ALTHOUGH THE FLOW MAY GET DISRUPTED FOR A TIME AS A SECONDARY TROUGH DROPS INTO THE REGION SATURDAY MORNING. EXPECT LOWS FRIDAY NIGHT IN THE UPPER TEENS TO UPPER 20S AND HIGHS ON SATURDAY RANGING FROM THE UPPER 20S AND LOWER 30S NORTHWEST TO THE MID 40S SOUTHEAST. THE PERIOD FROM SATURDAY NIGHT THROUGH TUESDAY LOOKS MAINLY DRY AND SEASONABLE WITH THE GGEM...ECMWF AND GFS ALL TAKING THE SOUTHERN STREAM SYSTEM SUNDAY MORNING OUT TO SEA OFF THE CAROLINA COAST WHICH SHOULD BE TOO FAR SOUTH AND EAST EVEN TO IMPACT OUR FAR SOUTHERN ZONES. EXPECT LOWS DURING THIS PERIOD TO GENERALLY RANGE FROM THE SINGLE DIGITS NORTHWEST TO UPPER TEENS TO LOW TO MID 20S SOUTH AND EAST. HIGHS ARE EXPECTED TO RANGE FROM THE UPPER 20S AND LOWER 30S NORTHWEST TO THE UPPER 30S TO LOWER 40S SOUTHEAST. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... A WEAK DISTURBANCE WILL CONTINUE TO GRADUALLY MOVE ACROSS THE AREA THROUGH MAINLY THIS MORNING. SOME OCCASIONAL LIGHT RAIN HAS DEVELOPED AT KPOU...HOWEVER THE AIR IN THE LOW LEVELS IS STILL QUITE DRY FROM KALB-KGFL...SO WILL NOT MENTION ANY PRECIP AT THOSE TWO SITES WITH CIGS LOWERING TO JUST ABOVE VFR THRESHOLD. WILL MENTION TEMPOS FOR OCCASIONAL LIGHT RAIN AS ASSOCIATED MVFR CONDITIONS AT KPOU THROUGH SUNRISE. CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL SITES LATER THIS MORNING INTO THE AFTERNOON AS WEAK HIGH PRESSURE STARTS TO BUILD IN. CLOUDS WILL LIKELY LINGER THROUGH THE AFTERNOON BUT CIGS SHOULD REMAIN IN VFR RANGE. CLOUDS WILL LIKELY SCOUR OUT THIS EVENING AS THE HIGH MOVES OVERHEAD WITH DRIER AIR. WINDS TODAY WILL INITIALLY BE LIGHT AND VARIABLE...SHIFTING TO A MAINLY NORTHWEST DIRECTION THIS AFTERNOON AROUND 4 TO 7 KT. OUTLOOK... WED NT-THU AM...VFR. NO SIG WX. THU PM-FRI...MVFR/IFR. -RA/-SN LIKELY. FRI NT-SAT...VFR. SLGT CHC -SHSN/-SHRA. SAT NT-SUN...MAINLY VFR...ALTHOUGH LOW PROB OF IFR WITH SNOW. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. SOME GAGES WILL CONTINUE TO HAVE ICE EFFECTS ACROSS THE NORTHERN TIER OF THE ALBANY HYDRO SERVICE AREA /HSA/. SOME VERY LIGHT PRECIPITATION IS POSSIBLE OVERNIGHT INTO WEDNESDAY...IN THE FORM OF LIGHT SNOW AND/OR RAIN SHOWERS. HOWEVER...LIQUID EQUIVALENT PRECIPITATION WILL REMAIN UNDER ONE TENTH OF AN INCH DURING THIS TIME. ANOTHER LOW PRESSURE SYSTEM COULD BRING RAIN AND/OR SNOW TO THE REGION LATE THURSDAY INTO THURSDAY NIGHT...WITH GENERALLY LIGHT TO MODERATE AMOUNTS OF PRECIPITATION EXPECTED. ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL NEAR TERM...FRUGIS SHORT TERM...KL LONG TERM...11 AVIATION...JPV HYDROLOGY...KL/GJM
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
331 PM EST WED FEB 15 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... LOW PRESSURE WILL TRACK THROUGH THE OHIO VALLEY TONIGHT...BRINGING WIDESPREAD RAIN AND PERHAPS A COUPLE THUNDERSTORMS FOR CENTRAL INDIANA. CHANCES FOR RAIN WILL END BY MIDDAY THURSDAY AS THE LOW PULLS AWAY TO THE EAST. HIGH PRESSURE WILL EXPAND INTO THE REGION BY THURSDAY NIGHT...WITH DRY WEATHER AND SEASONABLE TEMPERATURES EXPECTED THROUGH THE WEEKEND. PRECIP CHANCES WILL RETURN FOR NEXT TUESDAY AND WEDNESDAY AS A COLD FRONT MOVES THROUGH THE REGION. && .NEAR TERM /TONIGHT/... LIGHT RAINFALL CONTINUES TO EXPAND ACROSS CENTRAL INDIANA THIS AFTERNOON AHEAD OF A FRONTAL BOUNDARY MOVING APPROACHING FROM THE WEST. TEMPS HAD WARMED INTO THE MID 40S OVER EASTERN PORTIONS OF THE FORECAST AREA WHERE PRECIP WAS JUST BEGINNING TO ARRIVE. FURTHER WEST AS RAINFALL BEGINS...TEMPS SLIDING BACK A FEW DEGREES INTO THE LOWER 40S. FORECAST FOCUS TONIGHT IS ON RAIN CHANCES AS FRONTAL BOUNDARY ARRIVES AND A SURFACE WAVE TRACKS THROUGH THE REGION. HAVE RELIED MORE ON THE HRRR FOR RAINFALL COVERAGE INTO THIS EVENING AS BOTH THE NAM AND OP GFS ALREADY ARE TOO FAR NORTH AND NOT CAPTURING THE WIDESPREAD NATURE OF THE LIGHT PRECIP PROPERLY. BROAD SURFACE WAVE CURRENTLY LOCATED OVER OKLAHOMA WILL MOVE STEADILY NORTHEAST INTO THE OHIO VALLEY OVERNIGHT. WHILE PRECIP WILL REMAIN LIGHT OVER THE NEXT FEW HOURS...RAINFALL INTENSITY SHOULD INCREASE DURING THE EVENING AS 35-40KT LOW LEVEL JET PUMPS DEEPER MOISTURE INTO THE REGION AHEAD OF THE APPROACHING WAVE. BOTH OP GFS AND NAM INDICATE FAVORABLE PRECIP EFFICIENCY PROGS AFTER MIDNIGHT AS LOW LEVEL CONVERGENCE BELOW 700MB MAXIMIZES AND COINCIDES WITH AN AXIS OF PRECIP WATER VALUES APPROACHING 1 INCH. ENHANCED FORCING ALOFT WILL ALSO CONTRIBUTE TO WIDESPREAD RAINFALL WITH EMBEDDED CONVECTIVE ELEMENTS OVERNIGHT. HAVE CONTINUED WITH 100 POPS FOR THE ENTIRE FORECAST AREA...SPECIFICALLY FOCUSED AFTER MIDNIGHT WHEN FORCING AND MOISTURE ARE GREATEST. MODEL SOUNDINGS SHOWING WEAK ELEVATED INSTABILITY WHICH MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS OVER THE AREA LATE TONIGHT AS THE BOUNDARY APPROACHES AND WILL CONTINUE TO CARRY SLIGHT CHANCES FOR THUNDER. QPF VALUES OF 0.40 TO 0.75 INCHES STILL LOOKS QUITE REASONABLE BY DAYBREAK THURSDAY. TEMPS...TEMPS NOT LIKELY TO FALL MUCH OVERNIGHT AS COOLER AIR REALLY DOES NOT START TO WORK INTO THE REGION UNTIL RIGHT NEAR DAYBREAK AS THE FRONT SWEEPS THROUGH THE AREA. LAMP DATA DOING A MUCH BETTER JOB THAN MOS CAPTURING THIS THINKING...AND HAVE LEANED MUCH CLOSER TO ITS NUMBERS WITH LOWS RANGING FROM THE UPPER 30S NORTH TO NEAR 45 DEGREE OVER FAR SOUTHERN COUNTIES. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... FORECAST CHALLENGES FOCUS ON DEPARTURE OF RAINFALL AND CLOUDS ON THURSDAY. LINGERING RAINFALL EXPECTED TO END FROM WEST TO EAST ACROSS THE REGION DURING THE MORNING AS FRONTAL BOUNDARY SHIFTS AWAY TO THE EAST. HELD ONTO PREVIOUS FORECAST THINKING OF KEEPING ANY THUNDER MENTION OUT FOR THURSDAY MORNING WITH SOUNDINGS SHOWING NO ELEVATED INSTABILITY IN WAKE OF THE BOUNDARY. ISSUE DURING THE DAY WILL BECOME HOW QUICKLY LOW STRATUS DEPARTS WITH HIGH PRESSURE EXPANDING INTO THE OHIO VALLEY FROM THE WEST. LOW LEVEL RH PROGS AND MODEL SOUNDINGS BOTH SHOWING SHALLOW MOISTURE BECOMING TRAPPED UNDERNEATH A FAIRLY SHARP INVERSION. INVERSION GIVES WAY ONLY SLOWLY DESPITE THE INCREASING SUBSIDENCE AS THE DAY PROGRESSES. HELD OFF ON FULLY CLEARING SKIES UNTIL LATE AFTERNOON/EARLY EVENING AS THE INVERSION FINALLY GIVES WAY. REMAINDER OF THE SHORT TERM LOOKS QUIET AS HIGH PRESSURE REMAINS THE DOMINANT FEATURE. EXPECT MAINLY CLEAR SKIES THURSDAY NIGHT AND FRIDAY WITH JUST PERIODS OF CIRRUS FROM TIME TO TIME. LIKELY TO SEE A BUMP UP IN CLOUD COVERAGE FRIDAY NIGHT AS A SHORTWAVE ALOFT WITH A WEAK SURFACE WAVE PINWHEELS THROUGH THE LOWER GREAT LAKES. OP GFS REMAINS ALONE IN CONTINUING TO ADVERTISE INCREASING LOW LEVEL MOISTURE INTO THE REGION RIGHT AT THE END OF THE PERIOD EARLY SATURDAY DUE TO ENHANCED PHASING ALOFT BETWEEN THE AFOREMENTIONED SHORTWAVE AND A DEVELOPING STORM SYSTEM OVER THE NORTHERN GULF OF MEXICO. PREFER MODEL CONSENSUS WHICH MAINTAINS NO IMPACTS OTHER THAN SUBTLE INCREASES IN MID AND HIGH LEVEL CLOUD COVERAGE AS PREDOMINANT NORTHERLY FLOW THROUGH THE BOUNDARY LAYER CUTS OFF ANY ADVECTION OF GULF MOISTURE INTO THE OHIO VALLEY. TEMPS...UNDERCUT MOS GUIDANCE FOR TEMPS THURSDAY AS LINGERING LOW CLOUDS ARE LIKELY TO STUNT TEMP RISES IN COLD ADVECTION REGIME. WENT FAIRLY CLOSE TO MAVMOS GUIDANCE THROUGH THE REST OF THE PERIOD AS HIGHS SHOULD RECOVER INTO THE UPPER 40S ON FRIDAY. LOWS RANGING FROM THE MID 20S TO LOWER 30S ARE ANTICIPATED THURS/FRI NIGHTS. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... LATEST INITIALIZATION CONTINUES TO FAVOR THE NAM AND CANADIAN IN REGARD TO POSSIBLE PRECIP ON SATURDAY. ACCORDING TO THOSE MODELS...IT WILL BE A DRY FORECAST AS 2 DISTURBANCES JUST MISS CENTRAL INDIANA...ONE TO THE NORTH AND ONE TO THE SOUTH. HOWEVER...THE EXCEPTION CONTINUES TO BE THE GFS. FOR NOW...WILL STICK WITH MODEL CONSENSUS AND LEAVE PRECIP OUT OF FORECAST. BEYOND THAT...ALL MODELS ARE INDICATING RAIN ACROSS FORECAST AREA EARLY WEDNESDAY MORNING THROUGH THURSDAY MORNING AS THE NEXT LOW PRESSURE SYSTEM MOVES IN. THERE IS STILL SOME DISCREPANCY IN REGARD TO TIMING OF SYSTEM...WITH THE GFS BEING SLOWER THAN THE EURO. CONFIDENCE IS NOT HIGH ENOUGH TO GO ANY HIGHER THAN CHANCE POPS AT THIS TIME. SO WILL NOT DEVIATE FROM INITIALIZATION NUMBERS. WILL ALSO STAY WITH MODEL BLEND IN REGARD TO TEMPS THROUGH DURATION OF LONG TERM. && .AVIATION /DISCUSSION FOR THE 152030Z TAF UPDATE/... MVFR VISIBILITIES IN RAIN HAVE ALREADY ARRIVED AT KIND AND SHOULD CONTINUE FOR THE NEXT SEVERAL HOURS. CEILINGS ARE CURRENTLY VFR BUT THEY WILL DETERIORATE INTO MVFR AS WELL IN THE NEXT FEW HOURS. PREVIOUS DISCUSSION FOLLOWS... FLYING CONDITIONS WILL GRADUALLY DETERIORATE OVER THE NEXT FEW HOURS AS A LOW PRESSURE SYSTEM MOVES CLOSER TO TAF SITES. CURRENT RADAR IMAGERY IS ALREADY SHOWING PRECIP MOVING IN FROM THE SOUTHWEST. SO...MVFR/VFR CONDITIONS WILL CONTINUE UNTIL MID TO LATE AFTERNOON...AND THEN DETERIORATE TO IFR CATEGORY AS CEILINGS FALL WITH ONSET OF RAIN. RAIN WILL INTENSIFY AFTER THU 00Z AND CONTINUE THROUGH THE NIGHT. PRECIP WILL TAPER OFF AROUND DAYBREAK TOMORROW AND COME TO AN END BY MID MORNING. EXPECT A RETURN TO MVFR CONDITIONS AROUND THAT TIME AND THROUGH THE REMAINDER OF TAF PERIOD. WINDS WILL BE SOUTH/SOUTHEASTERLY AT 8 TO 10 KTS THROUGH TONIGHT BEFORE BECOMING WESTERLY IN WAKE OF THE SYSTEM TOMORROW MORNING. ALSO EXPECT AN INCREASE IN SPEEDS WITH WIND SHIFT. SUSTAINED WIND SPEEDS WILL INCREASE TO 10 TO 14 KTS WITH GUSTS TO 25 KTS THROUGH TOMORROW AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....TDUD AVIATION...TDUD/50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
329 PM EST WED FEB 15 2012 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... LOW PRESSURE WILL TRACK THROUGH THE OHIO VALLEY TONIGHT...BRINGING WIDESPREAD RAIN AND PERHAPS A COUPLE THUNDERSTORMS FOR CENTRAL INDIANA. CHANCES FOR RAIN WILL END BY MIDDAY THURSDAY AS THE LOW PULLS AWAY TO THE EAST. HIGH PRESSURE WILL EXPAND INTO THE REGION BY THURSDAY NIGHT...WITH DRY WEATHER AND SEASONABLE TEMPERATURES EXPECTED THROUGH THE WEEKEND. PRECIP CHANCES WILL RETURN FOR NEXT TUESDAY AND WEDNESDAY AS A COLD FRONT MOVES THROUGH THE REGION. && .NEAR TERM /TONIGHT/... LIGHT RAINFALL CONTINUES TO EXPAND ACROSS CENTRAL INDIANA THIS AFTERNOON AHEAD OF A FRONTAL BOUNDARY MOVING APPROACHING FROM THE WEST. TEMPS HAD WARMED INTO THE MID 40S OVER EASTERN PORTIONS OF THE FORECAST AREA WHERE PRECIP WAS JUST BEGINNING TO ARRIVE. FURTHER WEST AS RAINFALL BEGINS...TEMPS SLIDING BACK A FEW DEGREES INTO THE LOWER 40S. FORECAST FOCUS TONIGHT IS ON RAIN CHANCES AS FRONTAL BOUNDARY ARRIVES AND A SURFACE WAVE TRACKS THROUGH THE REGION. HAVE RELIED MORE ON THE HRRR FOR RAINFALL COVERAGE INTO THIS EVENING AS BOTH THE NAM AND OP GFS ALREADY ARE TOO FAR NORTH AND NOT CAPTURING THE WIDESPREAD NATURE OF THE LIGHT PRECIP PROPERLY. BROAD SURFACE WAVE CURRENTLY LOCATED OVER OKLAHOMA WILL MOVE STEADILY NORTHEAST INTO THE OHIO VALLEY OVERNIGHT. WHILE PRECIP WILL REMAIN LIGHT OVER THE NEXT FEW HOURS...RAINFALL INTENSITY SHOULD INCREASE DURING THE EVENING AS 35-40KT LOW LEVEL JET PUMPS DEEPER MOISTURE INTO THE REGION AHEAD OF THE APPROACHING WAVE. BOTH OP GFS AND NAM INDICATE FAVORABLE PRECIP EFFICIENCY PROGS AFTER MIDNIGHT AS LOW LEVEL CONVERGENCE BELOW 700MB MAXIMIZES AND COINCIDES WITH AN AXIS OF PRECIP WATER VALUES APPROACHING 1 INCH. ENHANCED FORCING ALOFT WILL ALSO CONTRIBUTE TO WIDESPREAD RAINFALL WITH EMBEDDED CONVECTIVE ELEMENTS OVERNIGHT. HAVE CONTINUED WITH 100 POPS FOR THE ENTIRE FORECAST AREA...SPECIFICALLY FOCUSED AFTER MIDNIGHT WHEN FORCING AND MOISTURE ARE GREATEST. MODEL SOUNDINGS SHOWING WEAK ELEVATED INSTABILITY WHICH MAY BE ENOUGH TO GENERATE A FEW THUNDERSTORMS OVER THE AREA LATE TONIGHT AS THE BOUNDARY APPROACHES AND WILL CONTINUE TO CARRY SLIGHT CHANCES FOR THUNDER. QPF VALUES OF 0.40 TO 0.75 INCHES STILL LOOKS QUITE REASONABLE BY DAYBREAK THURSDAY. TEMPS...TEMPS NOT LIKELY TO FALL MUCH OVERNIGHT AS COOLER AIR REALLY DOES NOT START TO WORK INTO THE REGION UNTIL RIGHT NEAR DAYBREAK AS THE FRONT SWEEPS THROUGH THE AREA. LAMP DATA DOING A MUCH BETTER JOB THAN MOS CAPTURING THIS THINKING...AND HAVE LEANED MUCH CLOSER TO ITS NUMBERS WITH LOWS RANGING FROM THE UPPER 30S NORTH TO NEAR 45 DEGREE OVER FAR SOUTHERN COUNTIES. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... FORECAST CHALLENGES FOCUS ON DEPARTURE OF RAINFALL AND CLOUDS ON THURSDAY. LINGERING RAINFALL EXPECTED TO END FROM WEST TO EAST ACROSS THE REGION DURING THE MORNING AS FRONTAL BOUNDARY SHIFTS AWAY TO THE EAST. HELD ONTO PREVIOUS FORECAST THINKING OF KEEPING ANY THUNDER MENTION OUT FOR THURSDAY MORNING WITH SOUNDINGS SHOWING NO ELEVATED INSTABILITY IN WAKE OF THE BOUNDARY. ISSUE DURING THE DAY WILL BECOME HOW QUICKLY LOW STRATUS DEPARTS WITH HIGH PRESSURE EXPANDING INTO THE OHIO VALLEY FROM THE WEST. LOW LEVEL RH PROGS AND MODEL SOUNDINGS BOTH SHOWING SHALLOW MOISTURE BECOMING TRAPPED UNDERNEATH A FAIRLY SHARP INVERSION. INVERSION GIVES WAY ONLY SLOWLY DESPITE THE INCREASING SUBSIDENCE AS THE DAY PROGRESSES. HELD OFF ON FULLY CLEARING SKIES UNTIL LATE AFTERNOON/EARLY EVENING AS THE INVERSION FINALLY GIVES WAY. REMAINDER OF THE SHORT TERM LOOKS QUIET AS HIGH PRESSURE REMAINS THE DOMINANT FEATURE. EXPECT MAINLY CLEAR SKIES THURSDAY NIGHT AND FRIDAY WITH JUST PERIODS OF CIRRUS FROM TIME TO TIME. LIKELY TO SEE A BUMP UP IN CLOUD COVERAGE FRIDAY NIGHT AS A SHORTWAVE ALOFT WITH A WEAK SURFACE WAVE PINWHEELS THROUGH THE LOWER GREAT LAKES. OP GFS REMAINS ALONE IN CONTINUING TO ADVERTISE INCREASING LOW LEVEL MOISTURE INTO THE REGION RIGHT AT THE END OF THE PERIOD EARLY SATURDAY DUE TO ENHANCED PHASING ALOFT BETWEEN THE AFOREMENTIONED SHORTWAVE AND A DEVELOPING STORM SYSTEM OVER THE NORTHERN GULF OF MEXICO. PREFER MODEL CONSENSUS WHICH MAINTAINS NO IMPACTS OTHER THAN SUBTLE INCREASES IN MID AND HIGH LEVEL CLOUD COVERAGE AS PREDOMINANT NORTHERLY FLOW THROUGH THE BOUNDARY LAYER CUTS OFF ANY ADVECTION OF GULF MOISTURE INTO THE OHIO VALLEY. TEMPS...UNDERCUT MOS GUIDANCE FOR TEMPS THURSDAY AS LINGERING LOW CLOUDS ARE LIKELY TO STUNT TEMP RISES IN COLD ADVECTION REGIME. WENT FAIRLY CLOSE TO MAVMOS GUIDANCE THROUGH THE REST OF THE PERIOD AS HIGHS SHOULD RECOVER INTO THE UPPER 40S ON FRIDAY. LOWS RANGING FROM THE MID 20S TO LOWER 30S ARE ANTICIPATED THURS/FRI NIGHTS. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... LATEST INITIALIZATION CONTINUES TO FAVOR THE NAM AND CANADIAN IN REGARD TO POSSIBLE PRECIP ON SATURDAY. ACCORDING TO THOSE MODELS...IT WILL BE A DRY FORECAST AS 2 DISTURBANCES JUST MISS CENTRAL INDIANA...ONE TO THE NORTH AND ONE TO THE SOUTH. HOWEVER...THE EXCEPTION CONTINUES TO BE THE GFS. FOR NOW...WILL STICK WITH MODEL CONSENSUS AND LEAVE PRECIP OUT OF FORECAST. BEYOND THAT...ALL MODELS ARE INDICATING RAIN ACROSS FORECAST AREA EARLY WEDNESDAY MORNING THROUGH THURSDAY MORNING AS THE NEXT LOW PRESSURE SYSTEM MOVES IN. THERE IS STILL SOME DISCREPANCY IN REGARD TO TIMING OF SYSTEM...WITH THE GFS BEING SLOWER THAN THE EURO. CONFIDENCE IS NOT HIGH ENOUGH TO GO ANY HIGHER THAN CHANCE POPS AT THIS TIME. SO WILL NOT DEVIATE FROM INITIALIZATION NUMBERS. WILL ALSO STAY WITH MODEL BLEND IN REGARD TO TEMPS THROUGH DURATION OF LONG TERM. && .AVIATION /DISCUSSION FOR THE 15/18Z TAF ISSUANCE/... FLYING CONDITIONS WILL GRADUALLY DETERIORATE OVER THE NEXT FEW HOURS AS A LOW PRESSURE SYSTEM MOVES CLOSER TO TAF SITES. CURRENT RADAR IMAGERY IS ALREADY SHOWING PRECIP MOVING IN FROM THE SOUTHWEST. SO...MVFR/VFR CONDITIONS WILL CONTINUE UNTIL MID TO LATE AFTERNOON...AND THEN DETERIORATE TO IFR CATEGORY AS CEILINGS FALL WITH ONSET OF RAIN. RAIN WILL INTENSIFY AFTER THU 00Z AND CONTINUE THROUGH THE NIGHT. PRECIP WILL TAPER OFF AROUND DAYBREAK TOMORROW AND COME TO AN END BY MID MORNING. EXPECT A RETURN TO MVFR CONDITIONS AROUND THAT TIME AND THROUGH THE REMAINDER OF TAF PERIOD. WINDS WILL BE SOUTH/SOUTHEASTERLY AT 8 TO 10 KTS THROUGH TONIGHT BEFORE BECOMING WESTERLY IN WAKE OF THE SYSTEM TOMORROW MORNING. ALSO EXPECT AN INCREASE IN SPEEDS WITH WIND SHIFT. SUSTAINED WIND SPEEDS WILL INCREASE TO 10 TO 14 KTS WITH GUSTS TO 25 KTS THROUGH TOMORROW AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....TDUD AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS DES MOINES IA
536 PM CST THU FEB 16 2012 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... LATEST WV IMAGERY WITH H500 RUC ANALYSIS SHOWED CONFLUENT UPPER LEVEL FLOW ACROSS THE MISSOURI RIVER VALLEY...WITH A WEAK SHORTWAVE APPROACHING THE MT/ND BORDER. SURFACE ANALYSIS DEPICTED 1025MB HIGH CENTERED OVER KS/MO BORDER...WITH A NORTH/SOUTH ORIENTED TROUGH LOCATED OVER THE CENTRAL DAKOTAS IN ASSOCIATION WITH THE AFOREMENTIONED SHORTWAVE. AS THE WEAK UPPER LEVEL WAVE MOVES SOUTHEAST ACROSS THE DAKOTAS OVERNIGHT...AND THE SURFACE HIGH MEANDERS EASTWARD...THE LOW LEVEL WINDS WILL GRADUALLY BACK FROM THE WEST TOWARD THE SOUTHWEST OVERNIGHT. THEY SHOULD REMAIN STRONG ENOUGH TO MITIGATE ANY WIDESPREAD DENSE FOG. HOWEVER...TIME HEIGHT CROSS SECTIONS SHOW SOME LOW LEVEL MOISTURE DEVELOPING BY MORNING...SO FEEL THAT PATCHY FOG IS POSSIBLE...ESPECIALLY ACROSS SNOW COVERED AREAS. FOR OVERNIGHT LOW TEMPS WENT WITH THE BIAS-CORRECTED GUIDANCE. .LONG TERM /FRIDAY THROUGH THURSDAY/... FORECAST CHALLENGE THROUGH THE PERIOD REMAINS THE UPPER LEVEL SYSTEM IMPACTING THE MIDWEST EARLY NEXT WEEK. BEFORE THEN...SHORT WAVE ENERGY DROPPING SOUTHEAST THROUGH ERN MONTANA/WRN NORTH DAKOTA WILL PUSH THROUGH FRIDAY MORNING. GOOD KINEMATICS AND A PUSH OF TEMPERATURE ADVECTION WILL ARRIVE WITH THE SYSTEM. THE SYSTEM WILL BE LACKING MOISTURE HOWEVER. THAT SAID...IT APPEARS TO BE A SMALL WINDOW WITH FLURRIES OR WORST CASE SCENARIO A LIGHT SNOW SHOWER TO MOVE THROUGH INTO MID MORNING. A SFC BOUNDARY WILL MOVE THROUGH DURING THE DAY ON FRIDAY AS WELL. IT WILL NOT REACH THE SOUTHEAST UNTIL THE AFTERNOON...THEREFORE A GOOD WARMUP AHEAD OF BOUNDARY IS POSSIBLE. THE COLD ADVECTION WILL BE FOCUSED NEAR 925 MB WITH THE SFC IMPACT LAGGING. WITH THIS...MIXING WILL OCCUR AND LIMIT THE SFC IMPACT ON TEMPERATURES DURING THE DAY. ANOTHER BOUNDARY WILL DROP SOUTH FRIDAY NIGHT AND WILL LEAD TO A COOLER YET DRY WEEKEND. STILL A COMPLEX SITUATION EARLY NEXT WEEK WITH AN ACTIVE FLOW AND NUMEROUS PIECES OF ENERGY MOVING THROUGH THE LONG WAVE TROUGH. THE FOCUS IS ON THREE OF THE EMBEDDED IMPULSES WITH ONE NORTH INTO CANADA...ONE IMPACTING THE MIDWEST AND ANOTHER DROPPING WELL TO THE SOUTH. EACH COULD CERTAINLY IMPACT THE OTHERS REGARDING TIMING AND PLACEMENT BUT AT THIS TIME...SOME CONSENSUS DEVELOPING REGARDING EACH. FOCUS FOR PRECIPITATION WILL BE LATE MONDAY THROUGH EARLY TUESDAY. TRENDS ARE SUGGESTING THE PRECIPITATION COULD BE MOSTLY SNOW OVER THE NORTH WITH A MIX OR EVEN ALL RAIN TO THE SOUTH. THE FLOW WILL REMAIN ACTIVE FOR THE REMAINDER OF THE EXTENDED WITH ADDITIONAL POTENTIAL FOR PRECIPITATION AND TEMPERATURES GENERALLY NEAR TO ABOVE SEASONAL VALUES. && .AVIATION...17/00Z SOME PATCHY FOG LOOKS TO DEVELOP LATE TONIGHT WITH WINDS DROPPING OFF AS SURFACE HIGH SHIFTS INTO EASTERN MISSOURI. HAVE MENTION OF MVFR VIS AT DSM/FOD/MCW. WINDS LOOK TO MIX BY MIDDAY FRIDAY WHICH LOOKS TO PROVIDE A BREEZY AFTERNOON. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BEITLICH LONG TERM...DONAVON AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
353 PM CST WED FEB 15 2012 ...UPDATED SYNOPSIS, SHORT TERM, AND LONG TERM SECTIONS... .SYNOPSIS... ISSUED AT 353 PM CST WED FEB 15 2012 THE 15.12Z 300 HPA SYNOPTIC MAP SHOWED A FAST 125 TO 140 KT JET EXTENDING ACROSS TEXAS AND INTO THE LOWER MISSOURI RIVER VALLEY. ANOTHER 75 TO 85 KT MERIDIONAL JET EXTENDED FROM OREGON INTO SOUTHERN CALIFORNIA. 500 HPA MAP ANALYSIS SHOWS TWO MID LEVEL DISTURBANCES ASSOCIATED WITH THESE JETS...ONE OVER EASTERN CA/WESTERN NV AND ANOTHER OPEN SHORTWAVE TROUGH ACROSS THE SOUTHERN/CENTRAL PLAINS. IN THE LOW TO MID LEVELS (850 TO 500 HPA), THE MOST INTERESTING ITEM OF NOTE, PARTICULARLY FOR THE KDDC RAOB, WAS STEEP LAPSE RATES. SURFACE FRONTAL ANALYSIS PER HPC AT 1943Z SHOWED A FRONTAL SYSTEM ACROSS KANSAS WITH A LOW PRESSURE CENTER ACROSS NW OKLAHOMA AND AN OCCLUDED FRONT ACROSS CENTRAL OKLAHOMA. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 353 PM CST WED FEB 15 2012 TONIGHT: THE NEAR TERM/MESOSCALE CONCERN FOR TONIGHT WAS WHAT TO DO WITH POPS FROM THE LATEST KDDC WSR-88D TRENDS. THIS PRECIPITATION IS BEING CAUSED BY A 700 HPA DEFORMATION AXIS ON THE BACKSIDE OF A SHORTWAVE TROUGH. RUC AND PARTICULARLY HRRR WERE AGGRESSIVE WITH FORECAST COMPOSITE REFLECTIVITIES THIS MORNING. IN ADDITION, 700 HPA OMEGA WAS ALSO NOTED IN THE SAME REGION. THE 700 HPA DEFORMATION ZONE PER SATELLITE OBSERVATIONS IS BECOMING STRETCHED ALONG AN AXIS OF DILATATION. THEREFORE HAVE TRIMMED THE POPS EVEN FURTHER FROM AN UPDATE THIS MORNING WITH THE AERIAL COVERAGE OF SHOWERS DIMINISHING TO NOTHING BY 00Z TONIGHT. MODELS SHOW THAT AFTER 00Z, LOWER DEWPOINT ADVECTION WILL OCCUR AT THE SURFACE. FORECAST SOUNDINGS ALSO SHOW A DRYING IN THE LOW TO MID LEVELS. THEREFORE HAVE A CLEARING TREND IN THE SKY GRIDS. A LIGHT NORTHWESTERLY TO NORTHERLY WIND IS EXPECTED OVERNIGHT. OVERNIGHT LOWS WILL BE PRIMARILY IN THE 20S DEG F. THURSDAY: A FORECAST CONCERN THAT WAS MENTIONED IN THE TAF SECTION BELOW WAS THE POTENTIAL FOR FREEZING FOG. MOS GUIDANCE WAS AGGRESSIVE, INCLUDING LAMP GUIDANCE, IN BRINGING LOW STRATUS AND FOG BACK TO THE REGION TOMORROW. BUFKIT FORECAST SOUNDINGS SHOW THAT THE LAYER OF SATURATION IS NEAR THE SURFACE AND DOESN`T EXTEND VERY FAR UP IN THE ATMOSPHERIC COLUMN FOR CONSIDERABLE DRYING/LARGE DEWPOINT DEPRESSIONS ARE FORECAST. AS A RESULT, WILL NOT BRING THE MENTION OF FREEZING FOG IN THE FORECAST FOR NOW. FROST LOOKS MORE LIKELY AT THE SURFACE. EVEN IF FREEZING FOG DOES OCCUR, IT SHOULD BE VERY PATCHY DUE TO DRY AIR IMMEDIATELY ABOVE THE SURFACE, INCLUDING WITHIN THE BOUNDARY LAYER. WINDS TOMORROW MORNING WILL BE LIGHT AND VARIABLE AS A CENTER OF HIGH PRESSURE MOVES ACROSS KANSAS. SOUTHERLY WINDS WILL DEVELOP BY TOMORROW AFTERNOON ACROSS THE FA ON THE WEST SIDE OF THE DEPARTING HIGH. HIGHS TOMORROW SHOULD BE IN THE UPPER 40S AND NEAR 50 DEG F. NO PRECIPITATION IS EXPECTED IN THE WAKE OF THE DEPARTING UPPER LEVEL SHORTWAVE TROUGH AND WITH SUBSIDENCE EXPECTED THROUGH THE ATMOSPHERIC COLUMN. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 353 PM CST WED FEB 15 2012 A FAIRLY ACTIVE UPPER LEVEL FLOW PATTERN IS FORECAST TO CONTINUE THROUGH THE EXTENDED PERIOD. AT THE BEGINNING OF THE PERIOD A BROAD TROUGH WILL BE SITUATED FROM HUDSON BAY INTO THE UPPER MIDWEST AND GREAT LAKES REGION WITH A SHORTWAVE TROUGH DROPPING SOUTH OUT OF CANADA INTO THE NORTHERN HIGH PLAINS. A TROUGH/CLOSED LOW WILL BE OVER THE DESERT SOUTHWEST INTO NORTHWEST MEXICO. THE GFS MODEL SHOWS THE NORTHERN PLAINS SHORTWAVE PHASING WITH THE SOUTHWEST CONUS SYSTEM WITH THE RESULTANT TROUGH MOVING INTO THE MISSISSIPPI VALLEY BY LATE IN THE WEEKEND. THIS MODEL ALSO BREAKS OUT SOME LIGHT PRECIPITATION OVER THE SOUTHERN PART OF THE FORECAST AREA SATURDAY NIGHT. THE ECMWF AND CANADIAN MODELS SHOW THE TWO SYSTEMS REMAINING SEPARATE WITH BOTH SYSTEMS PASSING BY EITHER NORTH OR SOUTH OF THE CENTRAL HIGH PLAINS. THE GFS HAS STRUGGLED WITH THIS SYSTEM OVER THE PAST SEVERAL RUNS WHICH LEADS LESS CREDENCE TO THAT MODEL SOLUTION. WILL GO WITH A DRY FORECAST FOR THAT TIME PERIOD. WHILE THIS WAVE IS MOVING EAST OF THE CENTRAL CONUS...ANOTHER SYSTEM WILL BE MOVING INTO THE ROCKIES. BY SUNDAY NIGHT AND MONDAY THE ECMWF SHOWS A PIECE OF THIS WAVE EJECTING OUT OVER WESTERN KANSAS WITH PRECIPITATION BREAKING OUT OVER WESTERN KANSAS. THE MODELS HAVE DIFFERING SOLUTIONS IN HOW THIS WAVE WILL EVOLVE AND WHEN IT WILL MOVE OUT THROUGH THE CENTRAL CONUS. NOT REAL CONFIDENT IN ANY SOLUTION BUT THE ECMWF SEEMS TO SHOW A LITTLE MORE CONTINUITY WITH ITS PREVIOUS RUNS. THE LATEST CR INIT HAS CHANCE/SLIGHT CHANCE POPS ESPECIALLY ACROSS THE NORTHERN 2/3RDS OFF THE CWA WHICH LOOKS REASONABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1135 AM CST WED FEB 15 2012 MODIFIED TAFS WITH A GRADUAL IMPROVEMENT IN CIGS THROUGH THE AFTERNOON. SHOWER ACTIVITY SHOULD BE NW OF THE TERMINALS SO DO NOT ANTICIPATE MUCH OF AN IMPACT IN THIS REGARD. HOWEVER, CIGS WILL REMAIN REDUCED DUE TO FOG/STRATUS/LOWERED VIS. MOS GUIDANCE WAS SUGGESTING FOG FORMATION FOR TOMORROW MORNING, HOWEVER, FORECAST SOUNDINGS (INCLUDING BUFKIT) SHOW THIS SHOULD BE PATCHY/ISOLATED SO WILL DEFER TO LATER TAF ISSUANCES DUE TO UNCERTAINTY. && .PRELIMINARY POINT TEMPS/POPS... DDC 22 48 26 50 / 10 0 0 10 GCK 19 48 24 51 / 0 0 0 0 EHA 21 49 27 53 / 0 0 0 10 LBL 22 51 25 53 / 20 0 0 10 HYS 21 47 26 47 / 0 0 0 0 P28 26 50 27 54 / 0 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM....GERARD AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1050 AM MST WED FEB 15 2012 .UPDATE... 731 AM MST WED FEB 15 2012 UPDATED GRIDS AND ZONES FOR THE CANCELLATION OF THE WINTER WEATHER ADVISORY. RADAR RETURNS AND OBSERVATIONS INDICATE THE LACK OF ANY PRECIPITATION SIGNIFICANT ENOUGH TO WARRANT AN ADVISORY. FS && .DISCUSSION... 326 AM MST WED FEB 15 2012 FORECAST CONCERN WILL BE WHAT KIND OF WEATHER TODAYS INCOMING SYSTEM IS GOING TO SPREAD ACROSS THE AREA. SATELLITE SHOWING A BROAD STRONG UPPER TROUGH OVER MOST OF THE PACIFIC WHICH IS CAUSING A RIDGE TO AMPLIFY ALONG THE WEST COAST. THEN OVER NORTH AMERICA THERE IS A CHAOTIC SPLIT FLOW WITH NUMEROUS SYSTEM MOVING THROUGH THIS FLOW. SYSTEM TO AFFECT US TODAY IS MOVING ACROSS NEW MEXICO WITH A SHORTWAVE MOVING THROUGH THE NORTH CENTRAL PORTION OF THE COUNTRY. ANOTHER SYSTEM MOVING SOUTH FROM THE PACIFIC NORTHWEST. AT JET LEVEL THE MODELS LOOKED FINE. MID LEVEL FLOW IS VERY CHAOTIC AND UNORGANIZED WITH A LOT OF SHORTWAVE TROUGH INTERACTION. INITIALLY AT 00Z...THE NAM FOLLOWED BY THE UKMET...GFS...AND CANADIAN WERE GETTING OUR SOUTHERN CIRCULATION THE BEST BASED ON SATELLITE AND UPPER AIR ANALYSIS. BY 06Z THE SYSTEM LOOKS TO HAVE SEPARATED INTO TWO DIFFERENT CIRCULATION. AT THIS TIME THE RUC FOLLOWED BY THE CANADIAN AND UKMET WAS CATCHING THE SYSTEM THE BEST OVER NEW MEXICO. FOR THE SYSTEM MOVING ACROSS THE NORTH CENTRAL PORTION OF THE COUNTRY...WHICH WILL AFFECT HOW THE SOUTHERN SYSTEM KICKS OUT...THE CANADIAN AND UKMET WERE DOING THE BEST THERE. AT THE SURFACE THE ECMWF IS CATCHING THE POSITION OF THE INCOMING FRONT BEST PLUS HAS THE BEST HANDLE ON THE SURFACE LOW POSITION TO OUR SOUTH. THE ECMWF AND CANADIAN ARE THE LOW LEVEL THERMAL AND MOISTURE PROFILE THE BEST. TODAY/TONIGHT...VERY TRICKY FORECAST FOR TODAY. MODELS HAVING TROUBLE IN DIFFERENT ASPECTS. OVERALL LIKE THE RUC...CANADIAN AND UKMET DEPICTION OF THE POSITION OF THE MID LEVEL CIRCULATION ALONG WITH THE QPF...SNOWFALL...AND WEATHER THEY ARE DEPICTING. CURRENTLY SATELLITE AND PLAN PROFILER WINDS SHOW THAT 700 MB TROUGHLINE IS WORKING ITS WAY ACROSS THE AREA AND ROUGHLY DIVIDES MY AREA INTO A NORTHWEST AND SOUTHEAST HALF. CURRENTLY IR SATELLITE AND MOSAIC RADAR HAVE THE COLDEST CLOUD TOPS AND RETURNS OVER THE SOUTHEAST HALF AHEAD OF THE TROUGHLINE. MODELS HAVE TENDED TO TAKE THE MID LEVEL CIRCULATION A LITTLE FURTHER SOUTH THAN YESTERDAY WITH MOST IN THE SAME GENERAL AREA BUT BASED ON SATELLITE AND REASONING GIVEN ABOVE THE RUC...CANADIAN AND UKMET TENDED TO HAVE IT FURTHER SOUTH. SO BELIEVE THE SOUTHEAST HALF OF THE AREA WILL HAVE THE BEST CHANCE FOR PRECIPITATION. HOWEVER AM CONCERNED WITH THE TROUGHLINE ALREADY WORKING ITS WAY ACROSS THE AREA AND THE NORTHERN STREAM SHORTWAVE MOVING IN WESTERLY FLOW ALOFT OVER THE FORECAST ALREADY. IF RUC IS CORRECT LITTLE TO NO PRECIPITATION WILL OCCUR. BUT NOT CONFIDENT TO TOTALLY ELIMINATE THAT. NEXT QUESTION WILL BE THE PHASE. SURFACE/850 MB DEWPOINTS AND TEMPERATURES START OUT ABOVE FREEZING IN THE SOUTHEAST PORTION OF THE AREA ACCORDING TO THE MODELS AND MATCH WELL WITH REALITY AT THIS TIME. THE COLD AIR DOES NOT REALLY ARRIVE IN ERNEST LATE BY LATE THIS MORNING AND EARLY AFTERNOON. THE WINDOW FOR FREEZING PRECIPITATION HAS NARROWED. FELT CONFIDENT ENOUGH TO TRIM OFF THE NORTHERN PORTION OF THE WINTER WEATHER ADVISORY. HOWEVER...IT LOOKS CLOSE ENOUGH IN THE SOUTHEAST THIRD REMAINS HIGH ENOUGH BUT CONFIDENCE IS NOT VERY HIGH. SO LOWERED ICE AMOUNTS IN THE ADVISORY AREA. ALSO BASED ON SOUNDINGS AND REALITY ADDED FREEZING FOG THIS MORNING. SHOULD BE ALL SNOW THIS AFTERNOON WITH THE SOUTHEAST MAYBE SEEING UP TO AN INCH BASED ON WHERE THE CIRCULATION APPEARS TO BE. QPF AND SNOW AMOUNTS ACTUALLY MAKE SENSE WITH WHERE THE LIFT IS GOING TO BE. WHATEVER FALLS SHOULD BE DONE BY 00Z. TEMPERATURES ARE INTERESTING FOR TODAY. WOULD BE SURPRISED TO SEE SOME SUN THIS AFTERNOON. RAISED MAXES A LITTLE BUT THAT STILL MAY NOT BE ENOUGH. THURSDAY/THURSDAY NIGHT...LOOKS TO BE A DECENT AMOUNT OF SUN. HOWEVER...SURFACE RIDGE IS NOT THAT FAR AWAY AND THE DOWNSLOPE COMPONENT TO THE WIND IS NOT THAT STRONG. SO SIDED WITH THE SLIGHTLY COOLER GUIDANCE. GET SOME DOWNSLOPE WARMING AND WINDS DURING THE NIGHT IN ADVANCE OF NEXT SURFACE TROUGH/FRONT THAT WILL MOVE THROUGH. FRIDAY/FRIDAY NIGHT...NORTHERN STREAM SHORTWAVE FORCES A FRONT THROUGH EARLY IN THE DAY. BASED ON COLD AIR ADVECTION/UNFAVORABLE WIND DIRECTION...DID TEND TOWARD THE COOLER TWO METER. LIGHT AND VARIABLE WINDS DURING THE NIGHT SHOULD ALLOW THE TEMPERATURES TO FALL BELOW GUIDANCE. BULLER SATURDAY THROUGH TUESDAY...SHORTWAVE RIDGE SHOULD KEEP CONDITIONS DRY SATURDAY AND SUNDAY. TEMPS SHOULD BE NEAR SEASONAL NORMS ON SATURDAY...AND ABOVE NORMAL SUNDAY. DEGREE OF WARM UP SUNDAY IS STILL IN QUESTION DUE TO UNCERTAINTY REGARDING EVOLUTION OF TROUGH EXPECTED TO ARRIVE SUNDAY NIGHT. GUIDANCE COMING INTO GOOD AGREEMENT ON TIMING OF NEGATIVELY TILTED TROUGH SUNDAY NIGHT...WHICH SHOULD BRING GOOD PRECIP CHANCES TO THE CWA SUNDAY NIGHT AND LINGERING CHANCES IN THE EASTERN CWA INTO MONDAY. WHILE GUIDANCE IS IS GOOD AGREEMENT ON THE TIMING...THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EVOLUTION OF THE SYSTEM. THE GFS IS MUCH STRONGER AND FARTHER NORTH WITH A CLOSED H5/H7 CIRCULATION ALMOST RIGHT ON TOP OF THE CWA SUNDAY NIGHT. THE LATEST GEM/ECMWF BOTH SUPPORT MORE OF AN OPEN WAVE SOLUTION OVER THE CWA...WITH A WEAKER CLOSED CIRCULATION OVER SOUTHERN KANSAS. THIS AFFECTS HOW FAR NORTH A POTENTIAL DRY SLOT SETS UP...AS WELL AS HOW MUCH COLD AIR IS IN PLACE OVER THE CWA FOR RAIN/SNOW CHANGEOVER. THE STRONGER GFS SOLUTION WOULD ALSO ALLOW FOR MUCH HIGHER QPF AND POTENTIAL SNOW ACCUMULATIONS...ESPECIALLY ALONG AND NORTH OF INTERSTATE 70. FOR NOW I HAVE BUMPED POPS NORTH OF INTERSTATE 70 WHERE BEST OVERLAP BETWEEN GUIDANCE IS ON MEASURABLE PRECIP. QPF AND POTENTIAL SNOW AMOUNTS ARE TOO DIFFICULT TO PIN DOWN AT THIS POINT...WITH A FAIRLY LARGE SPREAD ACROSS THE CWA DEPENDING ON MODEL OF CHOICE. THIS SYSTEM IS WORTH KEEPING AN EYE ON THOUGH. DRY CONDITIONS AND SEASONABLE TEMPS SHOULD BE FAVORED ON MONDAY NIGHT AND TUESDAY AS SHORTWAVE RIDGING BUILDS OVER THE CWA IN THE WAKE OF THE EXITING TROUGH...ASSUMING THERE ARE NO COMPLICATIONS FROM SNOW PACK. DR THANKS TO ALL WHO COLLABORATED. && .AVIATION... 1024 AM MST WED FEB 15 2012 FOR THE 18Z TAFS...CURRENT VISIBLE SATELLITE OBSERVATIONS INDICATE THAT STRATUS DECK IS BEGINNING TO ERODE AT KGLD AND WILL CONTINUE OVER THE NEXT HOUR OR TWO WITH CONDITIONS RETURNING TO VFR. KMCK HAS MANAGED TO STAY OUT OF A DECENT STRATUS DECK THIS MORNING AND WILL REMAIN VFR THROUGH THE REMAINDER OF THE PERIOD. GUSTY NORTH WINDS WILL SLOWLY DECREASE AT BOTH TERMINALS THROUGH THE AFTERNOON...BECOMING LIGHT OVERNIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE DEPARTING SYSTEM. MIDLEVEL CLOUD DECK MAY RETURN OVERNIGHT AS UPPER LEVEL LOW DIGS INTO THE DESERT SOUTHWEST. PMM && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1149 AM CST WED FEB 15 2012 ...UPDATE FOR NEAR TERM FORECAST AND 18Z TAFS... .UPDATE... ISSUED AT 1135 AM CST WED FEB 15 2012 HAVE TRIMMED DOWN POPS SIGNIFICANTLY BASED OFF LATEST KDDC WSR-88D TRENDS AND GUIDANCE FROM THE HRRR. FORECASTS SHOW THAT THE 700 HPA DEFORMATION ZONE/ENHANCED OMEGA REGION WILL BECOME STRETCHED OUT/DECREASE WITH TIME THIS AFTERNOON AND RADAR REFLECTIVITIES SHOULD WEAKEN AS A RESULT. THEREFORE, HAVE CONFINED POPS TO THE NW HALF OF THE FA AND RAMPED DOWN POPS QUICKLY BY 00Z. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM CST WED FEB 15 2012 TODAY`S FORECAST CHALLENGES CENTER AROUND POPS, WEATHER TYPES, AND TIMING. THE SHORT TERM MODELS, NAMELY THE HRRR AND THE NAM MODELS, DELAY THE ONSET OF PRECIPITATION IN OUR WEST AND SOUTH, BRINGING ONLY A LITTLE RAIN/SNOW MIX TO OUR NORTHEAST COUNTIES AROUND 10Z THIS MORNING. THEN AS A COLD FRONT RUSHES SOUTHWARD INTO OUR NORTHWEST CWA TOWARD 18Z. THE NAM MODEL IS SIMILAR TO THE HRRR IN BRINGING SNOW TO AN AREA NORTHWEST OF A ELKHART TO SCOTT CITY TO WAKEENEY LINE BY 18Z, THE FARTHER EAST BY 00Z. THE EC AND GFS MODELS ARE A LITTLE EARLIER AND MORE AGGRESSIVE THAN THE NAM MODEL, SO HAVE DELAYED THE START OF PRECIP IN OUR CENTRAL ZONES UNTIL AFTER 18Z. ALSO, LOWERED SNOW AMOUNTS IN THE SUBLETTE, DODGE CITY TO LARNED AREAS, THINKING THERE WILL BE ENOUGH RAIN FIRST BEFORE ANY SNOW STARTS THIS AFTERNOON TO LIMIT SNOW ACCUMULATIONS. IN THE SCOTT CITY, DIGHTON AND LAKIN AREAS, UP TO AN INCH OF SNOW IS POSSIBLE BY TONIGHT. THE FRONT MENTIONED ABOVE WILL SERVE AS A FOCUS BOUNDARY FOR ENHANCED LIFT. THERE IS A DEFORMATION ZONE SHOWN JUST NORTHWEST OF OUR CWA AT 18 TO 00Z BY THE ECMWF AND THE GFS MODELS. TEMPERATURES WON`T WARM TOO MUCH TODAY, ONLY RISING TO THE MID 30S IN OUR NORTH AND NORTHWESTERN COUNTIES, TO NEAR 40F DEGREES FROM LARNED TO DODGE CITY TO JOHNSON CITY. OUR EXTREME SOUTHEAST COULD RISE TO THE UPPER 40S, BEFORE THE COLD FRONT REACHES THERE THIS EVENING. THERE IS AN UPPER LOW PRESSURE SYSTEM MOVING EAST ACROSS THE KANSAS/OKLAHOMA BORDER. AS IT MOVES TO SOUTH CENTRAL KANSAS EARLY TONIGHT, AN AREA OF WRAP AROUND COLD AIR AND MOISTURE WILL KEEP CHANCE POPS FOR SNOW GOING IN THE NORTH AND NORTHEAST. DO NOT SEE MUCH SNOW ACCUMULATION OUT OF THIS SITUATION, AS SUBSTANTIAL MID AND UPPER LEVEL LIFT WILL BE TO OUR EAST. LOWERED POPS TO BELOW SLIGHT CHANCES BY 04Z, THINKING WE WILL BE WELL TO THE WEST OF ANY WRAP AROUND MOISTURE. MINIMUM TEMPERATURES SHOULD COOL TO THE 17F TO 19F DEGREE RANGE IN OUR NORTHWEST, WHERE THERE SHOULD BE A FRESH SNOW COVER OF AROUND 1 INCH. MID 20S WILL RESULT FROM LARNED TO DODGE CITY TO LIBERAL, WITH UPPER 20S FORECAST IN OUR SOUTHEASTERN CWA. I EXPECT A MOSTLY SUNNY THURSDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. SURFACE WINDS MAY START OUT FROM THE NORTH AT 10 TO 15 MPH, BUT SHOULD SHIFT TO THE SOUTH BY NOON AND ALLOW WARM ADVECTION TO HELP WARM MAXIMUM TEMPERATURES TO NEAR 50F DEGREES ALONG THE OKLAHOMA BORDER, THE MID 40S ACROSS OUR CENTRAL CWA, AND THE LOWER TO MIDDLE 40S IN OUR NORTHWEST WHERE A LITTLE SNOW MAY REMAIN. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 15 2012 PLEASANT WEATHER CONDITIONS ARE FORECASTED THURSDAY NIGHT THROUGH SATURDAY AS UPPER LEVEL FLOW WILL BE FROM THE WEST TO SOUTHWEST AND THE SURFACE WILL GENERALLY BE DOMINATED BY HIGH PRESSURE. THE ONLY EXCEPTION TO THIS WILL BE ON FRIDAY AFTERNOON WHEN A WEAK COLD FRONT MOVES THROUGH THE AREA INCREASING CLOUDS AND SHIFTING WINDS TO A NORTHERLY DIRECTION ACROSS WESTERN KANSAS. THIS COLD FRONT WILL BE PUSHED ACROSS THE AREA WITH HELP FROM AN UPPER LEVEL LOW MOVING ACROSS THE SOUTHERN PLAINS AND A SHORTWAVE MOVING THROUGH THE NORTHERN PLAINS. NO PRECIPITATION IS ANTICIPATED AT THIS TIME BUT IF FUTURE MODEL RUNS MOVE THE UPPER LEVEL LOW FURTHER NORTH THERE COULD INCREASED PRECIPITATION CHANCES ACROSS THE SOUTHERN TWO ROWS OF COUNTIES IN KANSAS. HIGHS WILL GENERALLY BE IN THE LOWER TO MID 50S ON FRIDAY THEN THE MID TO UPPER 40S ON SATURDAY. LOWS WILL GENERALLY BE IN THE MID TO UPPER 20S FRIDAY AND SATURDAY MORNING. MODELS ARE STILL IN GOOD AGREEMENT BRINGING AN UPPER LEVEL LOW ACROSS THE PACIFIC NORTHWEST SATURDAY, INTERMOUNTAIN WEST AND CENTRAL ROCKIES SUNDAY, AND INTO THE CENTRAL PLAINS ON MONDAY. THIS IN TURN WILL DEVELOP SURFACE LEE TROUGHING ACROSS EASTERN COLORADO AND SHIFT WINDS TO MORE OF A SOUTHERLY DIRECTION SATURDAY NIGHT THROUGH MONDAY MORNING. WINDY CONDITIONS COULD BE POSSIBLE ON SUNDAY AS THE LEE TROUGHING AND ATMOSPHERIC MIXING INCREASES ACROSS THE HIGH PLAINS. CLOUDS WILL BE ON THE INCREASE SUNDAY NIGHT AS THE SYSTEM APPROACHES WITH MOSTLY CLOUDY SKIES EXPECTED ON MONDAY. PRECIPITATION CHANCES WILL ALSO INCREASE SUNDAY NIGHT INTO MONDAY, MAINLY ACROSS NORTH AND NORTH CENTRAL KANSAS. PRECIPITATION TYPE IS STILL UNKNOWN BUT SHOULD BE IN THE FORM OF RAIN DURING THE DAY AS HIGHS WILL BE WELL ABOVE FREEZING. EXTENDED MODELS THEN HAVE SURFACE HIGH PRESSURE BUILDING INTO THE AREA ON TUESDAY WITH PARTLY CLOUDY SKIES AND DRY CONDITIONS ANTICIPATED. HIGHS ARE FORECASTED TO BE IN THE LOWER TO MID 50S SUNDAY, RANGE FROM THE MID 40S TO LOWER 50S MONDAY AND TUESDAY. LOWS WILL GENERALLY BE IN THE UPPER 20S TO MID 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1135 AM CST WED FEB 15 2012 MODIFIED TAFS WITH A GRADUAL IMPROVEMENT IN CIGS THROUGH THE AFTERNOON. SHOWER ACTIVITY SHOULD BE NW OF THE TERMINALS SO DO NOT ANTICIPATE MUCH OF AN IMPACT IN THIS REGARD. HOWEVER, CIGS WILL REMAIN REDUCED DUE TO FOG/STRATUS/LOWERED VIS. MOS GUIDANCE WAS SUGGESTING FOG FORMATION FOR TOMORROW MORNING, HOWEVER, FORECAST SOUNDINGS (INCLUDING BUFKIT) SHOW THIS SHOULD BE PATCHY/ISOLATED SO WILL DEFER TO LATER TAF ISSUANCES DUE TO UNCERTAINTY. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 25 47 27 / 40 20 0 0 GCK 39 20 47 25 / 60 10 0 0 EHA 43 23 49 28 / 30 0 0 0 LBL 45 24 48 26 / 20 10 0 0 HYS 37 20 45 27 / 60 30 0 0 P28 47 28 49 28 / 20 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SUGDEN SHORT TERM...BURKE LONG TERM....HOVORKA AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
735 AM MST WED FEB 15 2012 .UPDATE... 731 AM MST WED FEB 15 2012 UPDATED GRIDS AND ZONES FOR THE CANCELLATION OF THE WINTER WEATHER ADVISORY. RADAR RETURNS AND OBSERVATIONS INDICATE THE LACK OF ANY PRECIPITATION SIGNIFICANT ENOUGH TO WARRANT AN ADVISORY. FS && .DISCUSSION... 326 AM MST WED FEB 15 2012 FORECAST CONCERN WILL BE WHAT KIND OF WEATHER TODAYS INCOMING SYSTEM IS GOING TO SPREAD ACROSS THE AREA. SATELLITE SHOWING A BROAD STRONG UPPER TROUGH OVER MOST OF THE PACIFIC WHICH IS CAUSING A RIDGE TO AMPLIFY ALONG THE WEST COAST. THEN OVER NORTH AMERICA THERE IS A CHAOTIC SPLIT FLOW WITH NUMEROUS SYSTEM MOVING THROUGH THIS FLOW. SYSTEM TO AFFECT US TODAY IS MOVING ACROSS NEW MEXICO WITH A SHORTWAVE MOVING THROUGH THE NORTH CENTRAL PORTION OF THE COUNTRY. ANOTHER SYSTEM MOVING SOUTH FROM THE PACIFIC NORTHWEST. AT JET LEVEL THE MODELS LOOKED FINE. MID LEVEL FLOW IS VERY CHAOTIC AND UNORGANIZED WITH A LOT OF SHORTWAVE TROUGH INTERACTION. INITIALLY AT 00Z...THE NAM FOLLOWED BY THE UKMET...GFS...AND CANADIAN WERE GETTING OUR SOUTHERN CIRCULATION THE BEST BASED ON SATELLITE AND UPPER AIR ANALYSIS. BY 06Z THE SYSTEM LOOKS TO HAVE SEPARATED INTO TWO DIFFERENT CIRCULATION. AT THIS TIME THE RUC FOLLOWED BY THE CANADIAN AND UKMET WAS CATCHING THE SYSTEM THE BEST OVER NEW MEXICO. FOR THE SYSTEM MOVING ACROSS THE NORTH CENTRAL PORTION OF THE COUNTRY...WHICH WILL AFFECT HOW THE SOUTHERN SYSTEM KICKS OUT...THE CANADIAN AND UKMET WERE DOING THE BEST THERE. AT THE SURFACE THE ECMWF IS CATCHING THE POSITION OF THE INCOMING FRONT BEST PLUS HAS THE BEST HANDLE ON THE SURFACE LOW POSITION TO OUR SOUTH. THE ECMWF AND CANADIAN ARE THE LOW LEVEL THERMAL AND MOISTURE PROFILE THE BEST. TODAY/TONIGHT...VERY TRICKY FORECAST FOR TODAY. MODELS HAVING TROUBLE IN DIFFERENT ASPECTS. OVERALL LIKE THE RUC...CANADIAN AND UKMET DEPICTION OF THE POSITION OF THE MID LEVEL CIRCULATION ALONG WITH THE QPF...SNOWFALL...AND WEATHER THEY ARE DEPICTING. CURRENTLY SATELLITE AND PLAN PROFILER WINDS SHOW THAT 700 MB TROUGHLINE IS WORKING ITS WAY ACROSS THE AREA AND ROUGHLY DIVIDES MY AREA INTO A NORTHWEST AND SOUTHEAST HALF. CURRENTLY IR SATELLITE AND MOSAIC RADAR HAVE THE COLDEST CLOUD TOPS AND RETURNS OVER THE SOUTHEAST HALF AHEAD OF THE TROUGHLINE. MODELS HAVE TENDED TO TAKE THE MID LEVEL CIRCULATION A LITTLE FURTHER SOUTH THAN YESTERDAY WITH MOST IN THE SAME GENERAL AREA BUT BASED ON SATELLITE AND REASONING GIVEN ABOVE THE RUC...CANADIAN AND UKMET TENDED TO HAVE IT FURTHER SOUTH. SO BELIEVE THE SOUTHEAST HALF OF THE AREA WILL HAVE THE BEST CHANCE FOR PRECIPITATION. HOWEVER AM CONCERNED WITH THE TROUGHLINE ALREADY WORKING ITS WAY ACROSS THE AREA AND THE NORTHERN STREAM SHORTWAVE MOVING IN WESTERLY FLOW ALOFT OVER THE FORECAST ALREADY. IF RUC IS CORRECT LITTLE TO NO PRECIPITATION WILL OCCUR. BUT NOT CONFIDENT TO TOTALLY ELIMINATE THAT. NEXT QUESTION WILL BE THE PHASE. SURFACE/850 MB DEWPOINTS AND TEMPERATURES START OUT ABOVE FREEZING IN THE SOUTHEAST PORTION OF THE AREA ACCORDING TO THE MODELS AND MATCH WELL WITH REALITY AT THIS TIME. THE COLD AIR DOES NOT REALLY ARRIVE IN ERNEST LATE BY LATE THIS MORNING AND EARLY AFTERNOON. THE WINDOW FOR FREEZING PRECIPITATION HAS NARROWED. FELT CONFIDENT ENOUGH TO TRIM OFF THE NORTHERN PORTION OF THE WINTER WEATHER ADVISORY. HOWEVER...IT LOOKS CLOSE ENOUGH IN THE SOUTHEAST THIRD REMAINS HIGH ENOUGH BUT CONFIDENCE IS NOT VERY HIGH. SO LOWERED ICE AMOUNTS IN THE ADVISORY AREA. ALSO BASED ON SOUNDINGS AND REALITY ADDED FREEZING FOG THIS MORNING. SHOULD BE ALL SNOW THIS AFTERNOON WITH THE SOUTHEAST MAYBE SEEING UP TO AN INCH BASED ON WHERE THE CIRCULATION APPEARS TO BE. QPF AND SNOW AMOUNTS ACTUALLY MAKE SENSE WITH WHERE THE LIFT IS GOING TO BE. WHATEVER FALLS SHOULD BE DONE BY 00Z. TEMPERATURES ARE INTERESTING FOR TODAY. WOULD BE SURPRISED TO SEE SOME SUN THIS AFTERNOON. RAISED MAXES A LITTLE BUT THAT STILL MAY NOT BE ENOUGH. THURSDAY/THURSDAY NIGHT...LOOKS TO BE A DECENT AMOUNT OF SUN. HOWEVER...SURFACE RIDGE IS NOT THAT FAR AWAY AND THE DOWNSLOPE COMPONENT TO THE WIND IS NOT THAT STRONG. SO SIDED WITH THE SLIGHTLY COOLER GUIDANCE. GET SOME DOWNSLOPE WARMING AND WINDS DURING THE NIGHT IN ADVANCE OF NEXT SURFACE TROUGH/FRONT THAT WILL MOVE THROUGH. FRIDAY/FRIDAY NIGHT...NORTHERN STREAM SHORTWAVE FORCES A FRONT THROUGH EARLY IN THE DAY. BASED ON COLD AIR ADVECTION/UNFAVORABLE WIND DIRECTION...DID TEND TOWARD THE COOLER TWO METER. LIGHT AND VARIABLE WINDS DURING THE NIGHT SHOULD ALLOW THE TEMPERATURES TO FALL BELOW GUIDANCE. BULLER SATURDAY THROUGH TUESDAY...SHORTWAVE RIDGE SHOULD KEEP CONDITIONS DRY SATURDAY AND SUNDAY. TEMPS SHOULD BE NEAR SEASONAL NORMS ON SATURDAY...AND ABOVE NORMAL SUNDAY. DEGREE OF WARM UP SUNDAY IS STILL IN QUESTION DUE TO UNCERTAINTY REGARDING EVOLUTION OF TROUGH EXPECTED TO ARRIVE SUNDAY NIGHT. GUIDANCE COMING INTO GOOD AGREEMENT ON TIMING OF NEGATIVELY TILTED TROUGH SUNDAY NIGHT...WHICH SHOULD BRING GOOD PRECIP CHANCES TO THE CWA SUNDAY NIGHT AND LINGERING CHANCES IN THE EASTERN CWA INTO MONDAY. WHILE GUIDANCE IS IS GOOD AGREEMENT ON THE TIMING...THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EVOLUTION OF THE SYSTEM. THE GFS IS MUCH STRONGER AND FARTHER NORTH WITH A CLOSED H5/H7 CIRCULATION ALMOST RIGHT ON TOP OF THE CWA SUNDAY NIGHT. THE LATEST GEM/ECMWF BOTH SUPPORT MORE OF AN OPEN WAVE SOLUTION OVER THE CWA...WITH A WEAKER CLOSED CIRCULATION OVER SOUTHERN KANSAS. THIS AFFECTS HOW FAR NORTH A POTENTIAL DRY SLOT SETS UP...AS WELL AS HOW MUCH COLD AIR IS IN PLACE OVER THE CWA FOR RAIN/SNOW CHANGEOVER. THE STRONGER GFS SOLUTION WOULD ALSO ALLOW FOR MUCH HIGHER QPF AND POTENTIAL SNOW ACCUMULATIONS...ESPECIALLY ALONG AND NORTH OF INTERSTATE 70. FOR NOW I HAVE BUMPED POPS NORTH OF INTERSTATE 70 WHERE BEST OVERLAP BETWEEN GUIDANCE IS ON MEASURABLE PRECIP. QPF AND POTENTIAL SNOW AMOUNTS ARE TOO DIFFICULT TO PIN DOWN AT THIS POINT...WITH A FAIRLY LARGE SPREAD ACROSS THE CWA DEPENDING ON MODEL OF CHOICE. THIS SYSTEM IS WORTH KEEPING AN EYE ON THOUGH. DRY CONDITIONS AND SEASONABLE TEMPS SHOULD BE FAVORED ON MONDAY NIGHT AND TUESDAY AS SHORTWAVE RIDGING BUILDS OVER THE CWA IN THE WAKE OF THE EXITING TROUGH...ASSUMING THERE ARE NO COMPLICATIONS FROM SNOW PACK. DR THANKS TO ALL WHO COLLABORATED. && .AVIATION... 400 AM MST WED FEB 15 2012 FOR THE 12Z TAFS...AN AREA OF LOW STRATUS AROUND 700 FT AGL THAT HAS DEVELOPED OVER WESTERN NEBRASKA WILL CONTINUE TO MOVE SOUTH THIS MORNING TOWARDS BOTH TERMINALS. BASED ON SATELLITE TRENDS AND LATEST HIGH RES SHORT RANGE GUIDANCE THE LEADING EDGE OF THIS STATUS DECK SHOULD FIRST ARRIVE AT KMCK AROUND 1430Z AND THEN AT KGLD AFTER 15Z. GUIDANCE SHOWS THIS STRATUS ERODING BY 18Z AS MIXING INCREASES. VFR CONDITIONS SHOULD THEN PREVAIL THROUGH THE REMAINING TAF PERIOD AT BOTH SITES. GUSTY WINDS ARE EXPECTED TO DEVELOP AT BOTH TERMINALS DURING THE DAY...DECREASING AROUND 00Z. DR && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
528 AM CST WED FEB 15 2012 .UPDATE... ISSUED AT 527 AM CST WED FEB 15 2012 NO CHANGES NEEDED TO THE FORECAST AT THIS TIME. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM CST WED FEB 15 2012 TODAY`S FORECAST CHALLENGES CENTER AROUND POPS, WEATHER TYPES, AND TIMING. THE SHORT TERM MODELS, NAMELY THE HRRR AND THE NAM MODELS, DELAY THE ONSET OF PRECIPITATION IN OUR WEST AND SOUTH, BRINGING ONLY A LITTLE RAIN/SNOW MIX TO OUR NORTHEAST COUNTIES AROUND 10Z THIS MORNING. THEN AS A COLD FRONT RUSHES SOUTHWARD INTO OUR NORTHWEST CWA TOWARD 18Z. THE NAM MODEL IS SIMILAR TO THE HRRR IN BRINGING SNOW TO AN AREA NORTHWEST OF A ELKHART TO SCOTT CITY TO WAKEENEY LINE BY 18Z, THE FARTHER EAST BY 00Z. THE EC AND GFS MODELS ARE A LITTLE EARLIER AND MORE AGGRESSIVE THAN THE NAM MODEL, SO HAVE DELAYED THE START OF PRECIP IN OUR CENTRAL ZONES UNTIL AFTER 18Z. ALSO, LOWERED SNOW AMOUNTS IN THE SUBLETTE, DODGE CITY TO LARNED AREAS, THINKING THERE WILL BE ENOUGH RAIN FIRST BEFORE ANY SNOW STARTS THIS AFTERNOON TO LIMIT SNOW ACCUMULATIONS. IN THE SCOTT CITY, DIGHTON AND LAKIN AREAS, UP TO AN INCH OF SNOW IS POSSIBLE BY TONIGHT. THE FRONT MENTIONED ABOVE WILL SERVE AS A FOCUS BOUNDARY FOR ENHANCED LIFT. THERE IS A DEFORMATION ZONE SHOWN JUST NORTHWEST OF OUR CWA AT 18 TO 00Z BY THE ECMWF AND THE GFS MODELS. TEMPERATURES WON`T WARM TOO MUCH TODAY, ONLY RISING TO THE MID 30S IN OUR NORTH AND NORTHWESTERN COUNTIES, TO NEAR 40F DEGREES FROM LARNED TO DODGE CITY TO JOHNSON CITY. OUR EXTREME SOUTHEAST COULD RISE TO THE UPPER 40S, BEFORE THE COLD FRONT REACHES THERE THIS EVENING. THERE IS AN UPPER LOW PRESSURE SYSTEM MOVING EAST ACROSS THE KANSAS/OKLAHOMA BORDER. AS IT MOVES TO SOUTH CENTRAL KANSAS EARLY TONIGHT, AN AREA OF WRAP AROUND COLD AIR AND MOISTURE WILL KEEP CHANCE POPS FOR SNOW GOING IN THE NORTH AND NORTHEAST. DO NOT SEE MUCH SNOW ACCUMULATION OUT OF THIS SITUATION, AS SUBSTANTIAL MID AND UPPER LEVEL LIFT WILL BE TO OUR EAST. LOWERED POPS TO BELOW SLIGHT CHANCES BY 04Z, THINKING WE WILL BE WELL TO THE WEST OF ANY WRAP AROUND MOISTURE. MINIMUM TEMPERATURES SHOULD COOL TO THE 17F TO 19F DEGREE RANGE IN OUR NORTHWEST, WHERE THERE SHOULD BE A FRESH SNOW COVER OF AROUND 1 INCH. MID 20S WILL RESULT FROM LARNED TO DODGE CITY TO LIBERAL, WITH UPPER 20S FORECAST IN OUR SOUTHEASTERN CWA. I EXPECT A MOSTLY SUNNY THURSDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. SURFACE WINDS MAY START OUT FROM THE NORTH AT 10 TO 15 MPH, BUT SHOULD SHIFT TO THE SOUTH BY NOON AND ALLOW WARM ADVECTION TO HELP WARM MAXIMUM TEMPERATURES TO NEAR 50F DEGREES ALONG THE OKLAHOMA BORDER, THE MID 40S ACROSS OUR CENTRAL CWA, AND THE LOWER TO MIDDLE 40S IN OUR NORTHWEST WHERE A LITTLE SNOW MAY REMAIN. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 15 2012 PLEASANT WEATHER CONDITIONS ARE FORECASTED THURSDAY NIGHT THROUGH SATURDAY AS UPPER LEVEL FLOW WILL BE FROM THE WEST TO SOUTHWEST AND THE SURFACE WILL GENERALLY BE DOMINATED BY HIGH PRESSURE. THE ONLY EXCEPTION TO THIS WILL BE ON FRIDAY AFTERNOON WHEN A WEAK COLD FRONT MOVES THROUGH THE AREA INCREASING CLOUDS AND SHIFTING WINDS TO A NORTHERLY DIRECTION ACROSS WESTERN KANSAS. THIS COLD FRONT WILL BE PUSHED ACROSS THE AREA WITH HELP FROM AN UPPER LEVEL LOW MOVING ACROSS THE SOUTHERN PLAINS AND A SHORTWAVE MOVING THROUGH THE NORTHERN PLAINS. NO PRECIPITATION IS ANTICIPATED AT THIS TIME BUT IF FUTURE MODEL RUNS MOVE THE UPPER LEVEL LOW FURTHER NORTH THERE COULD INCREASED PRECIPITATION CHANCES ACROSS THE SOUTHERN TWO ROWS OF COUNTIES IN KANSAS. HIGHS WILL GENERALLY BE IN THE LOWER TO MID 50S ON FRIDAY THEN THE MID TO UPPER 40S ON SATURDAY. LOWS WILL GENERALLY BE IN THE MID TO UPPER 20S FRIDAY AND SATURDAY MORNING. MODELS ARE STILL IN GOOD AGREEMENT BRINGING AN UPPER LEVEL LOW ACROSS THE PACIFIC NORTHWEST SATURDAY, INTERMOUNTAIN WEST AND CENTRAL ROCKIES SUNDAY, AND INTO THE CENTRAL PLAINS ON MONDAY. THIS IN TURN WILL DEVELOP SURFACE LEE TROUGHING ACROSS EASTERN COLORADO AND SHIFT WINDS TO MORE OF A SOUTHERLY DIRECTION SATURDAY NIGHT THROUGH MONDAY MORNING. WINDY CONDITIONS COULD BE POSSIBLE ON SUNDAY AS THE LEE TROUGHING AND ATMOSPHERIC MIXING INCREASES ACROSS THE HIGH PLAINS. CLOUDS WILL BE ON THE INCREASE SUNDAY NIGHT AS THE SYSTEM APPROACHES WITH MOSTLY CLOUDY SKIES EXPECTED ON MONDAY. PRECIPITATION CHANCES WILL ALSO INCREASE SUNDAY NIGHT INTO MONDAY, MAINLY ACROSS NORTH AND NORTH CENTRAL KANSAS. PRECIPITATION TYPE IS STILL UNKNOWN BUT SHOULD BE IN THE FORM OF RAIN DURING THE DAY AS HIGHS WILL BE WELL ABOVE FREEZING. EXTENDED MODELS THEN HAVE SURFACE HIGH PRESSURE BUILDING INTO THE AREA ON TUESDAY WITH PARTLY CLOUDY SKIES AND DRY CONDITIONS ANTICIPATED. HIGHS ARE FORECASTED TO BE IN THE LOWER TO MID 50S SUNDAY, RANGE FROM THE MID 40S TO LOWER 50S MONDAY AND TUESDAY. LOWS WILL GENERALLY BE IN THE UPPER 20S TO MID 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 505 AM CST WED FEB 15 2012 THE TAFS THIS MORNING WILL START WITH IFR CIGS, AND IN THE DDC AND HYS CASES, ALSO WITH IFR VSBYS IN DENSE FOG. THE FOG SHOULD LIFT AND VSBYS IMPROVE BY 15Z, WHEN SOME MIXING WILL OCCUR DOWN FROM THE 850MB LEVEL. A COLD FRONT WILL SWEEP SOUTH AND CHANGE SOUTH SURFACE WINDS TO THE NORTH AT 15G25KT KNOT RANGE. LOW STATUS WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY, WITH LIGHT RAIN OR SNOW MOVING IN AFTER 18Z. THE PRECIP SHOULD END AROUND 02Z, WITH WINDS SUBSIDING TO NORTHWEST AROUND 10 MPH. CIGS WILL BREAK OUT AS HIGH PRESSURE BUILDS IN THIS EVENING, RETURNING AVIATION CATEGORIES TO VFR BY 01 TO 03Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 25 47 27 / 50 20 0 0 GCK 39 20 47 25 / 60 10 0 0 EHA 43 23 49 28 / 30 0 0 0 LBL 45 24 48 26 / 30 10 0 0 HYS 37 20 45 27 / 70 30 0 0 P28 47 28 49 28 / 40 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031- 043>046-062>066-075>081-085>090. && $$ UPDATE...BURKE SHORT TERM...BURKE LONG TERM....HOVORKA AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
506 AM CST WED FEB 15 2012 .UPDATE... FOR 12Z TAF ISSUANCE ISSUED AT 505 AM CST WED FEB 15 2012 && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM CST WED FEB 15 2012 TODAY`S FORECAST CHALLENGES CENTER AROUND POPS, WEATHER TYPES, AND TIMING. THE SHORT TERM MODELS, NAMELY THE HRRR AND THE NAM MODELS, DELAY THE ONSET OF PRECIPITATION IN OUR WEST AND SOUTH, BRINGING ONLY A LITTLE RAIN/SNOW MIX TO OUR NORTHEAST COUNTIES AROUND 10Z THIS MORNING. THEN AS A COLD FRONT RUSHES SOUTHWARD INTO OUR NORTHWEST CWA TOWARD 18Z. THE NAM MODEL IS SIMILAR TO THE HRRR IN BRINGING SNOW TO AN AREA NORTHWEST OF A ELKHART TO SCOTT CITY TO WAKEENEY LINE BY 18Z, THE FARTHER EAST BY 00Z. THE EC AND GFS MODELS ARE A LITTLE EARLIER AND MORE AGGRESSIVE THAN THE NAM MODEL, SO HAVE DELAYED THE START OF PRECIP IN OUR CENTRAL ZONES UNTIL AFTER 18Z. ALSO, LOWERED SNOW AMOUNTS IN THE SUBLETTE, DODGE CITY TO LARNED AREAS, THINKING THERE WILL BE ENOUGH RAIN FIRST BEFORE ANY SNOW STARTS THIS AFTERNOON TO LIMIT SNOW ACCUMULATIONS. IN THE SCOTT CITY, DIGHTON AND LAKIN AREAS, UP TO AN INCH OF SNOW IS POSSIBLE BY TONIGHT. THE FRONT MENTIONED ABOVE WILL SERVE AS A FOCUS BOUNDARY FOR ENHANCED LIFT. THERE IS A DEFORMATION ZONE SHOWN JUST NORTHWEST OF OUR CWA AT 18 TO 00Z BY THE ECMWF AND THE GFS MODELS. TEMPERATURES WON`T WARM TOO MUCH TODAY, ONLY RISING TO THE MID 30S IN OUR NORTH AND NORTHWESTERN COUNTIES, TO NEAR 40F DEGREES FROM LARNED TO DODGE CITY TO JOHNSON CITY. OUR EXTREME SOUTHEAST COULD RISE TO THE UPPER 40S, BEFORE THE COLD FRONT REACHES THERE THIS EVENING. THERE IS AN UPPER LOW PRESSURE SYSTEM MOVING EAST ACROSS THE KANSAS/OKLAHOMA BORDER. AS IT MOVES TO SOUTH CENTRAL KANSAS EARLY TONIGHT, AN AREA OF WRAP AROUND COLD AIR AND MOISTURE WILL KEEP CHANCE POPS FOR SNOW GOING IN THE NORTH AND NORTHEAST. DO NOT SEE MUCH SNOW ACCUMULATION OUT OF THIS SITUATION, AS SUBSTANTIAL MID AND UPPER LEVEL LIFT WILL BE TO OUR EAST. LOWERED POPS TO BELOW SLIGHT CHANCES BY 04Z, THINKING WE WILL BE WELL TO THE WEST OF ANY WRAP AROUND MOISTURE. MINIMUM TEMPERATURES SHOULD COOL TO THE 17F TO 19F DEGREE RANGE IN OUR NORTHWEST, WHERE THERE SHOULD BE A FRESH SNOW COVER OF AROUND 1 INCH. MID 20S WILL RESULT FROM LARNED TO DODGE CITY TO LIBERAL, WITH UPPER 20S FORECAST IN OUR SOUTHEASTERN CWA. I EXPECT A MOSTLY SUNNY THURSDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. SURFACE WINDS MAY START OUT FROM THE NORTH AT 10 TO 15 MPH, BUT SHOULD SHIFT TO THE SOUTH BY NOON AND ALLOW WARM ADVECTION TO HELP WARM MAXIMUM TEMPERATURES TO NEAR 50F DEGREES ALONG THE OKLAHOMA BORDER, THE MID 40S ACROSS OUR CENTRAL CWA, AND THE LOWER TO MIDDLE 40S IN OUR NORTHWEST WHERE A LITTLE SNOW MAY REMAIN. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 15 2012 PLEASANT WEATHER CONDITIONS ARE FORECASTED THURSDAY NIGHT THROUGH SATURDAY AS UPPER LEVEL FLOW WILL BE FROM THE WEST TO SOUTHWEST AND THE SURFACE WILL GENERALLY BE DOMINATED BY HIGH PRESSURE. THE ONLY EXCEPTION TO THIS WILL BE ON FRIDAY AFTERNOON WHEN A WEAK COLD FRONT MOVES THROUGH THE AREA INCREASING CLOUDS AND SHIFTING WINDS TO A NORTHERLY DIRECTION ACROSS WESTERN KANSAS. THIS COLD FRONT WILL BE PUSHED ACROSS THE AREA WITH HELP FROM AN UPPER LEVEL LOW MOVING ACROSS THE SOUTHERN PLAINS AND A SHORTWAVE MOVING THROUGH THE NORTHERN PLAINS. NO PRECIPITATION IS ANTICIPATED AT THIS TIME BUT IF FUTURE MODEL RUNS MOVE THE UPPER LEVEL LOW FURTHER NORTH THERE COULD INCREASED PRECIPITATION CHANCES ACROSS THE SOUTHERN TWO ROWS OF COUNTIES IN KANSAS. HIGHS WILL GENERALLY BE IN THE LOWER TO MID 50S ON FRIDAY THEN THE MID TO UPPER 40S ON SATURDAY. LOWS WILL GENERALLY BE IN THE MID TO UPPER 20S FRIDAY AND SATURDAY MORNING. MODELS ARE STILL IN GOOD AGREEMENT BRINGING AN UPPER LEVEL LOW ACROSS THE PACIFIC NORTHWEST SATURDAY, INTERMOUNTAIN WEST AND CENTRAL ROCKIES SUNDAY, AND INTO THE CENTRAL PLAINS ON MONDAY. THIS IN TURN WILL DEVELOP SURFACE LEE TROUGHING ACROSS EASTERN COLORADO AND SHIFT WINDS TO MORE OF A SOUTHERLY DIRECTION SATURDAY NIGHT THROUGH MONDAY MORNING. WINDY CONDITIONS COULD BE POSSIBLE ON SUNDAY AS THE LEE TROUGHING AND ATMOSPHERIC MIXING INCREASES ACROSS THE HIGH PLAINS. CLOUDS WILL BE ON THE INCREASE SUNDAY NIGHT AS THE SYSTEM APPROACHES WITH MOSTLY CLOUDY SKIES EXPECTED ON MONDAY. PRECIPITATION CHANCES WILL ALSO INCREASE SUNDAY NIGHT INTO MONDAY, MAINLY ACROSS NORTH AND NORTH CENTRAL KANSAS. PRECIPITATION TYPE IS STILL UNKNOWN BUT SHOULD BE IN THE FORM OF RAIN DURING THE DAY AS HIGHS WILL BE WELL ABOVE FREEZING. EXTENDED MODELS THEN HAVE SURFACE HIGH PRESSURE BUILDING INTO THE AREA ON TUESDAY WITH PARTLY CLOUDY SKIES AND DRY CONDITIONS ANTICIPATED. HIGHS ARE FORECASTED TO BE IN THE LOWER TO MID 50S SUNDAY, RANGE FROM THE MID 40S TO LOWER 50S MONDAY AND TUESDAY. LOWS WILL GENERALLY BE IN THE UPPER 20S TO MID 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 505 AM CST WED FEB 15 2012 THE TAFS THIS MORNING WILL START WITH IFR CIGS, AND IN THE DDC AND HYS CASES, ALSO WITH IFR VSBYS IN DENSE FOG. THE FOG SHOULD LIFT AND VSBYS IMPROVE BY 15Z, WHEN SOME MIXING WILL OCCUR DOWN FROM THE 850MB LEVEL. A COLD FRONT WILL SWEEP SOUTH AND CHANGE SOUTH SURFACE WINDS TO THE NORTH AT 15G25KT KNOT RANGE. LOW STATUS WILL LIKELY HANG AROUND THROUGH MUCH OF THE DAY, WITH LIGHT RAIN OR SNOW MOVING IN AFTER 18Z. THE PRECIP SHOULD END AROUND 02Z, WITH WINDS SUBSIDING TO NORTHWEST AROUND 10 MPH. CIGS WILL BREAK OUT AS HIGH PRESSURE BUILDS IN THIS EVENING, RETURNING AVIATION CATEGORIES TO VFR BY 01 TO 03Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 25 47 27 / 50 20 0 0 GCK 39 20 47 25 / 60 10 0 0 EHA 43 23 49 28 / 30 0 0 0 LBL 45 24 48 26 / 30 10 0 0 HYS 37 20 45 27 / 70 30 0 0 P28 47 28 49 28 / 40 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031- 043>046-062>066-075>081-085>090. && $$ UPDATE...BURKE SHORT TERM...BURKE LONG TERM....HOVORKA AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 AM MST WED FEB 15 2012 .DISCUSSION... 326 AM MST WED FEB 15 2012 FORECAST CONCERN WILL BE WHAT KIND OF WEATHER TODAYS INCOMING SYSTEM IS GOING TO SPREAD ACROSS THE AREA. SATELLITE SHOWING A BROAD STRONG UPPER TROUGH OVER MOST OF THE PACIFIC WHICH IS CAUSING A RIDGE TO AMPLIFY ALONG THE WEST COAST. THEN OVER NORTH AMERICA THERE IS A CHAOTIC SPLIT FLOW WITH NUMEROUS SYSTEM MOVING THROUGH THIS FLOW. SYSTEM TO AFFECT US TODAY IS MOVING ACROSS NEW MEXICO WITH A SHORTWAVE MOVING THROUGH THE NORTH CENTRAL PORTION OF THE COUNTRY. ANOTHER SYSTEM MOVING SOUTH FROM THE PACIFIC NORTHWEST. AT JET LEVEL THE MODELS LOOKED FINE. MID LEVEL FLOW IS VERY CHAOTIC AND UNORGANIZED WITH A LOT OF SHORTWAVE TROUGH INTERACTION. INITIALLY AT 00Z...THE NAM FOLLOWED BY THE UKMET...GFS...AND CANADIAN WERE GETTING OUR SOUTHERN CIRCULATION THE BEST BASED ON SATELLITE AND UPPER AIR ANALYSIS. BY 06Z THE SYSTEM LOOKS TO HAVE SEPARATED INTO TWO DIFFERENT CIRCULATION. AT THIS TIME THE RUC FOLLOWED BY THE CANADIAN AND UKMET WAS CATCHING THE SYSTEM THE BEST OVER NEW MEXICO. FOR THE SYSTEM MOVING ACROSS THE NORTH CENTRAL PORTION OF THE COUNTRY...WHICH WILL AFFECT HOW THE SOUTHERN SYSTEM KICKS OUT...THE CANADIAN AND UKMET WERE DOING THE BEST THERE. AT THE SURFACE THE ECMWF IS CATCHING THE POSITION OF THE INCOMING FRONT BEST PLUS HAS THE BEST HANDLE ON THE SURFACE LOW POSITION TO OUR SOUTH. THE ECMWF AND CANADIAN ARE THE LOW LEVEL THERMAL AND MOISTURE PROFILE THE BEST. TODAY/TONIGHT...VERY TRICKY FORECAST FOR TODAY. MODELS HAVING TROUBLE IN DIFFERENT ASPECTS. OVERALL LIKE THE RUC...CANADIAN AND UKMET DEPICTION OF THE POSITION OF THE MID LEVEL CIRCULATION ALONG WITH THE QPF...SNOWFALL...AND WEATHER THEY ARE DEPICTING. CURRENTLY SATELLITE AND PLAN PROFILER WINDS SHOW THAT 700 MB TROUGHLINE IS WORKING ITS WAY ACROSS THE AREA AND ROUGHLY DIVIDES MY AREA INTO A NORTHWEST AND SOUTHEAST HALF. CURRENTLY IR SATELLITE AND MOSAIC RADAR HAVE THE COLDEST CLOUD TOPS AND RETURNS OVER THE SOUTHEAST HALF AHEAD OF THE TROUGHLINE. MODELS HAVE TENDED TO TAKE THE MID LEVEL CIRCULATION A LITTLE FURTHER SOUTH THAN YESTERDAY WITH MOST IN THE SAME GENERAL AREA BUT BASED ON SATELLITE AND REASONING GIVEN ABOVE THE RUC...CANADIAN AND UKMET TENDED TO HAVE IT FURTHER SOUTH. SO BELIEVE THE SOUTHEAST HALF OF THE AREA WILL HAVE THE BEST CHANCE FOR PRECIPITATION. HOWEVER AM CONCERNED WITH THE TROUGHLINE ALREADY WORKING ITS WAY ACROSS THE AREA AND THE NORTHERN STREAM SHORTWAVE MOVING IN WESTERLY FLOW ALOFT OVER THE FORECAST ALREADY. IF RUC IS CORRECT LITTLE TO NO PRECIPITATION WILL OCCUR. BUT NOT CONFIDENT TO TOTALLY ELIMINATE THAT. NEXT QUESTION WILL BE THE PHASE. SURFACE/850 MB DEWPOINTS AND TEMPERATURES START OUT ABOVE FREEZING IN THE SOUTHEAST PORTION OF THE AREA ACCORDING TO THE MODELS AND MATCH WELL WITH REALITY AT THIS TIME. THE COLD AIR DOES NOT REALLY ARRIVE IN ERNEST LATE BY LATE THIS MORNING AND EARLY AFTERNOON. THE WINDOW FOR FREEZING PRECIPITATION HAS NARROWED. FELT CONFIDENT ENOUGH TO TRIM OFF THE NORTHERN PORTION OF THE WINTER WEATHER ADVISORY. HOWEVER...IT LOOKS CLOSE ENOUGH IN THE SOUTHEAST THIRD REMAINS HIGH ENOUGH BUT CONFIDENCE IS NOT VERY HIGH. SO LOWERED ICE AMOUNTS IN THE ADVISORY AREA. ALSO BASED ON SOUNDINGS AND REALITY ADDED FREEZING FOG THIS MORNING. SHOULD BE ALL SNOW THIS AFTERNOON WITH THE SOUTHEAST MAYBE SEEING UP TO AN INCH BASED ON WHERE THE CIRCULATION APPEARS TO BE. QPF AND SNOW AMOUNTS ACTUALLY MAKE SENSE WITH WHERE THE LIFT IS GOING TO BE. WHATEVER FALLS SHOULD BE DONE BY 00Z. TEMPERATURES ARE INTERESTING FOR TODAY. WOULD BE SURPRISED TO SEE SOME SUN THIS AFTERNOON. RAISED MAXES A LITTLE BUT THAT STILL MAY NOT BE ENOUGH. THURSDAY/THURSDAY NIGHT...LOOKS TO BE A DECENT AMOUNT OF SUN. HOWEVER...SURFACE RIDGE IS NOT THAT FAR AWAY AND THE DOWNSLOPE COMPONENT TO THE WIND IS NOT THAT STRONG. SO SIDED WITH THE SLIGHTLY COOLER GUIDANCE. GET SOME DOWNSLOPE WARMING AND WINDS DURING THE NIGHT IN ADVANCE OF NEXT SURFACE TROUGH/FRONT THAT WILL MOVE THROUGH. FRIDAY/FRIDAY NIGHT...NORTHERN STREAM SHORTWAVE FORCES A FRONT THROUGH EARLY IN THE DAY. BASED ON COLD AIR ADVECTION/UNFAVORABLE WIND DIRECTION...DID TEND TOWARD THE COOLER TWO METER. LIGHT AND VARIABLE WINDS DURING THE NIGHT SHOULD ALLOW THE TEMPERATURES TO FALL BELOW GUIDANCE. BULLER SATURDAY THROUGH TUESDAY...SHORTWAVE RIDGE SHOULD KEEP CONDITIONS DRY SATURDAY AND SUNDAY. TEMPS SHOULD BE NEAR SEASONAL NORMS ON SATURDAY...AND ABOVE NORMAL SUNDAY. DEGREE OF WARM UP SUNDAY IS STILL IN QUESTION DUE TO UNCERTAINTY REGARDING EVOLUTION OF TROUGH EXPECTED TO ARRIVE SUNDAY NIGHT. GUIDANCE COMING INTO GOOD AGREEMENT ON TIMING OF NEGATIVELY TILTED TROUGH SUNDAY NIGHT...WHICH SHOULD BRING GOOD PRECIP CHANCES TO THE CWA SUNDAY NIGHT AND LINGERING CHANCES IN THE EASTERN CWA INTO MONDAY. WHILE GUIDANCE IS IS GOOD AGREEMENT ON THE TIMING...THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EVOLUTION OF THE SYSTEM. THE GFS IS MUCH STRONGER AND FARTHER NORTH WITH A CLOSED H5/H7 CIRCULATION ALMOST RIGHT ON TOP OF THE CWA SUNDAY NIGHT. THE LATEST GEM/ECMWF BOTH SUPPORT MORE OF AN OPEN WAVE SOLUTION OVER THE CWA...WITH A WEAKER CLOSED CIRCULATION OVER SOUTHERN KANSAS. THIS AFFECTS HOW FAR NORTH A POTENTIAL DRY SLOT SETS UP...AS WELL AS HOW MUCH COLD AIR IS IN PLACE OVER THE CWA FOR RAIN/SNOW CHANGEOVER. THE STRONGER GFS SOLUTION WOULD ALSO ALLOW FOR MUCH HIGHER QPF AND POTENTIAL SNOW ACCUMULATIONS...ESPECIALLY ALONG AND NORTH OF INTERSTATE 70. FOR NOW I HAVE BUMPED POPS NORTH OF INTERSTATE 70 WHERE BEST OVERLAP BETWEEN GUIDANCE IS ON MEASURABLE PRECIP. QPF AND POTENTIAL SNOW AMOUNTS ARE TOO DIFFICULT TO PIN DOWN AT THIS POINT...WITH A FAIRLY LARGE SPREAD ACROSS THE CWA DEPENDING ON MODEL OF CHOICE. THIS SYSTEM IS WORTH KEEPING AN EYE ON THOUGH. DRY CONDITIONS AND SEASONABLE TEMPS SHOULD BE FAVORED ON MONDAY NIGHT AND TUESDAY AS SHORTWAVE RIDGING BUILDS OVER THE CWA IN THE WAKE OF THE EXITING TROUGH...ASSUMING THERE ARE NO COMPLICATIONS FROM SNOW PACK. DR THANKS TO ALL WHO COLLABORATED. && .AVIATION... 400 AM MST WED FEB 15 2012 FOR THE 12Z TAFS...AN AREA OF LOW STRATUS AROUND 700 FT AGL THAT HAS DEVELOPED OVER WESTERN NEBRASKA WILL CONTINUE TO MOVE SOUTH THIS MORNING TOWARDS BOTH TERMINALS. BASED ON SATELLITE TRENDS AND LATEST HIGH RES SHORT RANGE GUIDANCE THE LEADING EDGE OF THIS STATUS DECK SHOULD FIRST ARRIVE AT KMCK AROUND 1430Z AND THEN AT KGLD AFTER 15Z. GUIDANCE SHOWS THIS STRATUS ERODING BY 18Z AS MIXING INCREASES. VFR CONDITIONS SHOULD THEN PREVAIL THROUGH THE REMAINING TAF PERIOD AT BOTH SITES. GUSTY WINDS ARE EXPECTED TO DEVELOP AT BOTH TERMINALS DURING THE DAY...DECREASING AROUND 00Z. DR && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ004-015-016-028-029-041-042. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
326 AM MST WED FEB 15 2012 .DISCUSSION... 326 AM MST WED FEB 15 2012 FORECAST CONCERN WILL BE WHAT KIND OF WEATHER TODAYS INCOMING SYSTEM IS GOING TO SPREAD ACROSS THE AREA. SATELLITE SHOWING A BROAD STRONG UPPER TROUGH OVER MOST OF THE PACIFIC WHICH IS CAUSING A RIDGE TO AMPLIFY ALONG THE WEST COAST. THEN OVER NORTH AMERICA THERE IS A CHAOTIC SPLIT FLOW WITH NUMEROUS SYSTEM MOVING THROUGH THIS FLOW. SYSTEM TO AFFECT US TODAY IS MOVING ACROSS NEW MEXICO WITH A SHORTWAVE MOVING THROUGH THE NORTH CENTRAL PORTION OF THE COUNTRY. ANOTHER SYSTEM MOVING SOUTH FROM THE PACIFIC NORTHWEST. AT JET LEVEL THE MODELS LOOKED FINE. MID LEVEL FLOW IS VERY CHAOTIC AND UNORGANIZED WITH A LOT OF SHORTWAVE TROUGH INTERACTION. INITIALLY AT 00Z...THE NAM FOLLOWED BY THE UKMET...GFS...AND CANADIAN WERE GETTING OUR SOUTHERN CIRCULATION THE BEST BASED ON SATELLITE AND UPPER AIR ANALYSIS. BY 06Z THE SYSTEM LOOKS TO HAVE SEPARATED INTO TWO DIFFERENT CIRCULATION. AT THIS TIME THE RUC FOLLOWED BY THE CANADIAN AND UKMET WAS CATCHING THE SYSTEM THE BEST OVER NEW MEXICO. FOR THE SYSTEM MOVING ACROSS THE NORTH CENTRAL PORTION OF THE COUNTRY...WHICH WILL AFFECT HOW THE SOUTHERN SYSTEM KICKS OUT...THE CANADIAN AND UKMET WERE DOING THE BEST THERE. AT THE SURFACE THE ECMWF IS CATCHING THE POSITION OF THE INCOMING FRONT BEST PLUS HAS THE BEST HANDLE ON THE SURFACE LOW POSITION TO OUR SOUTH. THE ECMWF AND CANADIAN ARE THE LOW LEVEL THERMAL AND MOISTURE PROFILE THE BEST. TODAY/TONIGHT...VERY TRICKY FORECAST FOR TODAY. MODELS HAVING TROUBLE IN DIFFERENT ASPECTS. OVERALL LIKE THE RUC...CANADIAN AND UKMET DEPICTION OF THE POSITION OF THE MID LEVEL CIRCULATION ALONG WITH THE QPF...SNOWFALL...AND WEATHER THEY ARE DEPICTING. CURRENTLY SATELLITE AND PLAN PROFILER WINDS SHOW THAT 700 MB TROUGHLINE IS WORKING ITS WAY ACROSS THE AREA AND ROUGHLY DIVIDES MY AREA INTO A NORTHWEST AND SOUTHEAST HALF. CURRENTLY IR SATELLITE AND MOSAIC RADAR HAVE THE COLDEST CLOUD TOPS AND RETURNS OVER THE SOUTHEAST HALF AHEAD OF THE TROUGHLINE. MODELS HAVE TENDED TO TAKE THE MID LEVEL CIRCULATION A LITTLE FURTHER SOUTH THAN YESTERDAY WITH MOST IN THE SAME GENERAL AREA BUT BASED ON SATELLITE AND REASONING GIVEN ABOVE THE RUC...CANADIAN AND UKMET TENDED TO HAVE IT FURTHER SOUTH. SO BELIEVE THE SOUTHEAST HALF OF THE AREA WILL HAVE THE BEST CHANCE FOR PRECIPITATION. HOWEVER AM CONCERNED WITH THE TROUGHLINE ALREADY WORKING ITS WAY ACROSS THE AREA AND THE NORTHERN STREAM SHORTWAVE MOVING IN WESTERLY FLOW ALOFT OVER THE FORECAST ALREADY. IF RUC IS CORRECT LITTLE TO NO PRECIPITATION WILL OCCUR. BUT NOT CONFIDENT TO TOTALLY ELIMINATE THAT. NEXT QUESTION WILL BE THE PHASE. SURFACE/850 MB DEWPOINTS AND TEMPERATURES START OUT ABOVE FREEZING IN THE SOUTHEAST PORTION OF THE AREA ACCORDING TO THE MODELS AND MATCH WELL WITH REALITY AT THIS TIME. THE COLD AIR DOES NOT REALLY ARRIVE IN ERNEST LATE BY LATE THIS MORNING AND EARLY AFTERNOON. THE WINDOW FOR FREEZING PRECIPITATION HAS NARROWED. FELT CONFIDENT ENOUGH TO TRIM OFF THE NORTHERN PORTION OF THE WINTER WEATHER ADVISORY. HOWEVER...IT LOOKS CLOSE ENOUGH IN THE SOUTHEAST THIRD REMAINS HIGH ENOUGH BUT CONFIDENCE IS NOT VERY HIGH. SO LOWERED ICE AMOUNTS IN THE ADVISORY AREA. ALSO BASED ON SOUNDINGS AND REALITY ADDED FREEZING FOG THIS MORNING. SHOULD BE ALL SNOW THIS AFTERNOON WITH THE SOUTHEAST MAYBE SEEING UP TO AN INCH BASED ON WHERE THE CIRCULATION APPEARS TO BE. QPF AND SNOW AMOUNTS ACTUALLY MAKE SENSE WITH WHERE THE LIFT IS GOING TO BE. WHATEVER FALLS SHOULD BE DONE BY 00Z. TEMPERATURES ARE INTERESTING FOR TODAY. WOULD BE SURPRISED TO SEE SOME SUN THIS AFTERNOON. RAISED MAXES A LITTLE BUT THAT STILL MAY NOT BE ENOUGH. THURSDAY/THURSDAY NIGHT...LOOKS TO BE A DECENT AMOUNT OF SUN. HOWEVER...SURFACE RIDGE IS NOT THAT FAR AWAY AND THE DOWNSLOPE COMPONENT TO THE WIND IS NOT THAT STRONG. SO SIDED WITH THE SLIGHTLY COOLER GUIDANCE. GET SOME DOWNSLOPE WARMING AND WINDS DURING THE NIGHT IN ADVANCE OF NEXT SURFACE TROUGH/FRONT THAT WILL MOVE THROUGH. FRIDAY/FRIDAY NIGHT...NORTHERN STREAM SHORTWAVE FORCES A FRONT THROUGH EARLY IN THE DAY. BASED ON COLD AIR ADVECTION/UNFAVORABLE WIND DIRECTION...DID TEND TOWARD THE COOLER TWO METER. LIGHT AND VARIABLE WINDS DURING THE NIGHT SHOULD ALLOW THE TEMPERATURES TO FALL BELOW GUIDANCE. BULLER SATURDAY THROUGH TUESDAY...SHORTWAVE RIDGE SHOULD KEEP CONDITIONS DRY SATURDAY AND SUNDAY. TEMPS SHOULD BE NEAR SEASONAL NORMS ON SATURDAY...AND ABOVE NORMAL SUNDAY. DEGREE OF WARM UP SUNDAY IS STILL IN QUESTION DUE TO UNCERTAINTY REGARDING EVOLUTION OF TROUGH EXPECTED TO ARRIVE SUNDAY NIGHT. GUIDANCE COMING INTO GOOD AGREEMENT ON TIMING OF NEGATIVELY TILTED TROUGH SUNDAY NIGHT...WHICH SHOULD BRING GOOD PRECIP CHANCES TO THE CWA SUNDAY NIGHT AND LINGERING CHANCES IN THE EASTERN CWA INTO MONDAY. WHILE GUIDANCE IS IS GOOD AGREEMENT ON THE TIMING...THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EVOLUTION OF THE SYSTEM. THE GFS IS MUCH STRONGER AND FARTHER NORTH WITH A CLOSED H5/H7 CIRCULATION ALMOST RIGHT ON TOP OF THE CWA SUNDAY NIGHT. THE LATEST GEM/ECMWF BOTH SUPPORT MORE OF AN OPEN WAVE SOLUTION OVER THE CWA...WITH A WEAKER CLOSED CIRCULATION OVER SOUTHERN KANSAS. THIS AFFECTS HOW FAR NORTH A POTENTIAL DRY SLOT SETS UP...AS WELL AS HOW MUCH COLD AIR IS IN PLACE OVER THE CWA FOR RAIN/SNOW CHANGEOVER. THE STRONGER GFS SOLUTION WOULD ALSO ALLOW FOR MUCH HIGHER QPF AND POTENTIAL SNOW ACCUMULATIONS...ESPECIALLY ALONG AND NORTH OF INTERSTATE 70. FOR NOW I HAVE BUMPED POPS NORTH OF INTERSTATE 70 WHERE BEST OVERLAP BETWEEN GUIDANCE IS ON MEASURABLE PRECIP. QPF AND POTENTIAL SNOW AMOUNTS ARE TOO DIFFICULT TO PIN DOWN AT THIS POINT...WITH A FAIRLY LARGE SPREAD ACROSS THE CWA DEPENDING ON MODEL OF CHOICE. THIS SYSTEM IS WORTH KEEPING AN EYE ON THOUGH. DRY CONDITIONS AND SEASONABLE TEMPS SHOULD BE FAVORED ON MONDAY NIGHT AND TUESDAY AS SHORTWAVE RIDGING BUILDS OVER THE CWA IN THE WAKE OF THE EXITING TROUGH...ASSUMING THERE ARE NO COMPLICATIONS FROM SNOW PACK. DR THANKS TO ALL WHO COLLABORATED. && .AVIATION... 1030 PM MST TUE FEB 14 2012 FOR THE 06Z TAFS AT KGLD AND KMCK...FOR KGLD VFR CONDITIONS EXPECTED THROUGH 14Z WITH ONLY MID AND HIGH LEVEL CLOUDS EXPECTED. STRATUS AND RESTRICTED VIS HAS MADE IT TO KOEL...WITH KGLD WINDS NOW FROM THE NW SHOULD NOT SEE THESE RESTRICTIONS AT THE TERMINAL. HOWEVER...MVFR CIGS STILL EXPECTED FROM 14Z-21Z GIVEN CURRENT UPSTREAM OBSERVATIONS. BY 21Z CLOUDS WILL QUICKLY DECREASE WITH VFR CONDITIONS. NW WINDS GUSTING CLOSE TO 30KTS FROM 14Z-23Z. PRECIPITATION WILL BE CLOSE TO THE TERMINAL BUT RIGHT NOW NOT CONFIDENT ENOUGH TO INCLUDE IT IN THE TAF. FOR KMCK VFR CONDITIONS EXPECTED TIL AT LEAST 08Z WHERE WE WILL NEED TO WATCH JUST HOW FAR NORTH STRATUS AND RESTRICTED VIS GET TO TERMINAL. RIGHT NOW THINK IT WILL REMAIN JUST OUTSIDE THE TERMINAL. VFR CONDITIONS STILL EXPECTED THROUGH 16Z WHEN POST FRONTAL MVFR/IFR CIGS POSSIBLE THROUGH 21Z...QUICKLY BECOMING SKC SHORTLY THEREAFTER. 007 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WINTER WEATHER ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ004-015-016-028-029-041-042. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
314 AM CST WED FEB 15 2012 .SYNOPSIS... ISSUED AT 314 AM CST WED FEB 15 2012 THE 250 MB CHART ANALYSIS INDICATED TWO UPPER JETS OVER THE SOUTH CENTRAL AND EASTERN HALF OF THE COUNTRY. THE STRONGER, LARGER SCALE JET RAN FROM WESTERN MEXICO THROUGH CENTRAL TEXAS TO ABOUT 125 MILES EAST OF THE FLORIDA COAST. MAXIMUM SPEEDS WITHIN THIS SOUTHERN JET WERE IN THE 100-120KT RANGE. THE SECONDARY JET WAS ORIENTED WEST TO EAST FROM NORTHERN MISSOURI TO TO THE VIRGINA/NORTH CAROLINA COAST AND FURTHER EAST. MAX JET SPEED WITH THIS NORTHERN BRANCH WERE IN THE 100 TO 110 KT RANGE. SOUTHWEST FLOW CONTINUED AT BOTH 500 AND 700MB LEVELS, WITH A LOW PRESSURE SYSTEM OVER NORTHEASTERN ARIZONA. THE 500MB TEMPERATURE WAS -24C AT DDC, AND THE 700MB TEMP WAS -02C. THE 850MB CHART SHOWED A LOW PRESSURE AREA OVER EAST CENTRAL COLORADO, WITH A COLD FRONT TRAILING BACK TO THE SOUTH AND SOUTHWEST THROUGH NEW MEXICO. A WARM FRONT EXTENDED SOUTHEAST FROM THE LOW TO SOUTHEASTERN OKLAHOMA. ANOTHER COLD FRONT WAS EVIDENT FROM A LOW IN EXTREME SOUTHEASTERN NORTH DAKOTA, SWEEPING SOUTH AND WEST THROUGH NORTHERN NEBRASKA TO ANOTHER LOW IN EXTREME SOUTHWEST MONTANA. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 314 AM CST WED FEB 15 2012 TODAY`S FORECAST CHALLENGES CENTER AROUND POPS, WEATHER TYPES, AND TIMING. THE SHORT TERM MODELS, NAMELY THE HRRR AND THE NAM MODELS, DELAY THE ONSET OF PRECIPITATION IN OUR WEST AND SOUTH, BRINGING ONLY A LITTLE RAIN/SNOW MIX TO OUR NORTHEAST COUNTIES AROUND 10Z THIS MORNING. THEN AS A COLD FRONT RUSHES SOUTHWARD INTO OUR NORTHWEST CWA TOWARD 18Z. THE NAM MODEL IS SIMILAR TO THE HRRR IN BRINGING SNOW TO AN AREA NORTHWEST OF A ELKHART TO SCOTT CITY TO WAKEENEY LINE BY 18Z, THE FARTHER EAST BY 00Z. THE EC AND GFS MODELS ARE A LITTLE EARLIER AND MORE AGGRESSIVE THAN THE NAM MODEL, SO HAVE DELAYED THE START OF PRECIP IN OUR CENTRAL ZONES UNTIL AFTER 18Z. ALSO, LOWERED SNOW AMOUNTS IN THE SUBLETTE, DODGE CITY TO LARNED AREAS, THINKING THERE WILL BE ENOUGH RAIN FIRST BEFORE ANY SNOW STARTS THIS AFTERNOON TO LIMIT SNOW ACCUMULATIONS. IN THE SCOTT CITY, DIGHTON AND LAKIN AREAS, UP TO AN INCH OF SNOW IS POSSIBLE BY TONIGHT. THE FRONT MENTIONED ABOVE WILL SERVE AS A FOCUS BOUNDARY FOR ENHANCED LIFT. THERE IS A DEFORMATION ZONE SHOWN JUST NORTHWEST OF OUR CWA AT 18 TO 00Z BY THE ECMWF AND THE GFS MODELS. TEMPERATURES WON`T WARM TOO MUCH TODAY, ONLY RISING TO THE MID 30S IN OUR NORTH AND NORTHWESTERN COUNTIES, TO NEAR 40F DEGREES FROM LARNED TO DODGE CITY TO JOHNSON CITY. OUR EXTREME SOUTHEAST COULD RISE TO THE UPPER 40S, BEFORE THE COLD FRONT REACHES THERE THIS EVENING. THERE IS AN UPPER LOW PRESSURE SYSTEM MOVING EAST ACROSS THE KANSAS/OKLAHOMA BORDER. AS IT MOVES TO SOUTH CENTRAL KANSAS EARLY TONIGHT, AN AREA OF WRAP AROUND COLD AIR AND MOISTURE WILL KEEP CHANCE POPS FOR SNOW GOING IN THE NORTH AND NORTHEAST. DO NOT SEE MUCH SNOW ACCUMULATION OUT OF THIS SITUATION, AS SUBSTANTIAL MID AND UPPER LEVEL LIFT WILL BE TO OUR EAST. LOWERED POPS TO BELOW SLIGHT CHANCES BY 04Z, THINKING WE WILL BE WELL TO THE WEST OF ANY WRAP AROUND MOISTURE. MINIMUM TEMPERATURES SHOULD COOL TO THE 17F TO 19F DEGREE RANGE IN OUR NORTHWEST, WHERE THERE SHOULD BE A FRESH SNOW COVER OF AROUND 1 INCH. MID 20S WILL RESULT FROM LARNED TO DODGE CITY TO LIBERAL, WITH UPPER 20S FORECAST IN OUR SOUTHEASTERN CWA. I EXPECT A MOSTLY SUNNY THURSDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. SURFACE WINDS MAY START OUT FROM THE NORTH AT 10 TO 15 MPH, BUT SHOULD SHIFT TO THE SOUTH BY NOON AND ALLOW WARM ADVECTION TO HELP WARM MAXIMUM TEMPERATURES TO NEAR 50F DEGREES ALONG THE OKLAHOMA BORDER, THE MID 40S ACROSS OUR CENTRAL CWA, AND THE LOWER TO MIDDLE 40S IN OUR NORTHWEST WHERE A LITTLE SNOW MAY REMAIN. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 314 AM CST WED FEB 15 2012 PLEASANT WEATHER CONDITIONS ARE FORECASTED THURSDAY NIGHT THROUGH SATURDAY AS UPPER LEVEL FLOW WILL BE FROM THE WEST TO SOUTHWEST AND THE SURFACE WILL GENERALLY BE DOMINATED BY HIGH PRESSURE. THE ONLY EXCEPTION TO THIS WILL BE ON FRIDAY AFTERNOON WHEN A WEAK COLD FRONT MOVES THROUGH THE AREA INCREASING CLOUDS AND SHIFTING WINDS TO A NORTHERLY DIRECTION ACROSS WESTERN KANSAS. THIS COLD FRONT WILL BE PUSHED ACROSS THE AREA WITH HELP FROM AN UPPER LEVEL LOW MOVING ACROSS THE SOUTHERN PLAINS AND A SHORTWAVE MOVING THROUGH THE NORTHERN PLAINS. NO PRECIPITATION IS ANTICIPATED AT THIS TIME BUT IF FUTURE MODEL RUNS MOVE THE UPPER LEVEL LOW FURTHER NORTH THERE COULD INCREASED PRECIPITATION CHANCES ACROSS THE SOUTHERN TWO ROWS OF COUNTIES IN KANSAS. HIGHS WILL GENERALLY BE IN THE LOWER TO MID 50S ON FRIDAY THEN THE MID TO UPPER 40S ON SATURDAY. LOWS WILL GENERALLY BE IN THE MID TO UPPER 20S FRIDAY AND SATURDAY MORNING. MODELS ARE STILL IN GOOD AGREEMENT BRINGING AN UPPER LEVEL LOW ACROSS THE PACIFIC NORTHWEST SATURDAY, INTERMOUNTAIN WEST AND CENTRAL ROCKIES SUNDAY, AND INTO THE CENTRAL PLAINS ON MONDAY. THIS IN TURN WILL DEVELOP SURFACE LEE TROUGHING ACROSS EASTERN COLORADO AND SHIFT WINDS TO MORE OF A SOUTHERLY DIRECTION SATURDAY NIGHT THROUGH MONDAY MORNING. WINDY CONDITIONS COULD BE POSSIBLE ON SUNDAY AS THE LEE TROUGHING AND ATMOSPHERIC MIXING INCREASES ACROSS THE HIGH PLAINS. CLOUDS WILL BE ON THE INCREASE SUNDAY NIGHT AS THE SYSTEM APPROACHES WITH MOSTLY CLOUDY SKIES EXPECTED ON MONDAY. PRECIPITATION CHANCES WILL ALSO INCREASE SUNDAY NIGHT INTO MONDAY, MAINLY ACROSS NORTH AND NORTH CENTRAL KANSAS. PRECIPITATION TYPE IS STILL UNKNOWN BUT SHOULD BE IN THE FORM OF RAIN DURING THE DAY AS HIGHS WILL BE WELL ABOVE FREEZING. EXTENDED MODELS THEN HAVE SURFACE HIGH PRESSURE BUILDING INTO THE AREA ON TUESDAY WITH PARTLY CLOUDY SKIES AND DRY CONDITIONS ANTICIPATED. HIGHS ARE FORECASTED TO BE IN THE LOWER TO MID 50S SUNDAY, RANGE FROM THE MID 40S TO LOWER 50S MONDAY AND TUESDAY. LOWS WILL GENERALLY BE IN THE UPPER 20S TO MID 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1050 PM CST TUE FEB 14 2012 LATEST NAM, RUC AND HRRR CONTINUES TO INDICATED A 700-900 METER DEEP LAYER OF LOW LEVEL MOISTURE SPREADING ACROSS MOST OF SOUTHWEST AND PORTIONS OF NORTH CENTRAL KANSAS OVERNIGHT. AS OF 05Z CIGS AT DDC WERE ALREADY AT 200FEET WITH A BK DECK OF 300FT CIGS STARTING TO SPREAD INTO GCK. BU FR SOUNDINGS INDICATING THE BOTH DDC AND GCK HAVE THE POTENTIAL OF VSBYS TO FALL BELOW 1/4MILE EARLY THIS MORNING. HAYS VSBYS WILL BE SLIGHTLY BETTER BUT LIFR CIGS STILL ARE ANTICIPATED. DENSE FOG WILL BE THE MAIN HAZARD AT DDC OVERNIGHT BUT AT GCK AND HYS SOME LIGHT RAINSHOWERS WILL ALSO BE POSSIBLE AS 850MB WARM AIR ADVECTION IMPROVES. WIND SPEEDS OVERNIGHT AT ALL THREE TAF SITES WILL BE AT LESS THAN 10KTS. ON WEDNESDAY THE RAIN WILL CHANGE OVER TO SNOW AS THE ATMOSPHERE COOLS AHEAD OF AN APPROACHING UPPER LEVEL TROUGH. AS THIS UPPER LEVEL TROUGH PASSES SOUTHWEST KANSAS/TEXAS PANHANDLE LATE IN THE DAY...SUBSIDENCE IS EXPECTED TO DEVELOP IN ITS WAKE AND AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BEGIN TO BUILD INTO THE AREA. THIS WILL RESULT IN CLEARING SKIES AND DECREASING WINDS...MAINLY AFTER 00Z THURSDAY. UNTIL THEN NORTH WINDS WILL DEVELOP DURING EARLY IN THE DAY WITH AFTERNOON WIND SPEEDS INCREASING TO AROUND 15 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 38 25 47 26 / 70 40 0 0 GCK 38 22 47 24 / 70 30 0 0 EHA 43 23 48 28 / 30 10 0 0 LBL 45 24 49 25 / 30 20 0 0 HYS 36 22 45 26 / 70 40 0 0 P28 47 28 49 28 / 40 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ063>066- 077>081-087>090. && $$ SYNOPSIS...BURKE SHORT TERM...BURKE LONG TERM....HOVORKA AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
253 AM CST WED FEB 15 2012 .UPDATE... ISSUED AT 245 AM CST WED FEB 15 2012 UPDATED TO EXTEND THE DENSE FOG ADVISORY TO THE NORTH AND A LITTLE FARTHER WEST. THE 11U-3.9U SATELLITE IMAGERY WAS SHOWING THE FOG AND LOW CLOUDS ADVANCING BOTH WEST AND NORTH AT 08Z. MESHED THESE NEW AREA`S NPW WITH THE PREVIOUS NPW, IN EFFECT UNTIL 15Z. DEW POINTS ADVECTING NORTH AND NORTHWEST ARE COLLIDING WITH SLIGHTLY DRIER DEW POINTS IN OUR FAR WEST, THUS DID NOT INCLUDE OUR 3 WESTERN-MOST COUNTIES IN THE NPW. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW NIGHT) ISSUED AT 246 PM CST TUE FEB 14 2012 THE CHALLENGE IN THE FORECAST CONTINUES TO BE TEMPERATURES/PRECIPITATION TYPE AND WHERE THE HEAVIEST ACCUMULATION OF PRECIPITATION WILL OCCUR. TONIGHT...A SURFACE LOW WILL CONTINUE TO DEVELOP OVER FAR SOUTHEAST COLORADO THROUGH THE EVENING AND WINDS WILL CONTINUE TO RESPOND OUT OF THE SOUTHEAST. THIS WIND DIRECTION WILL ACTUALLY BE A COLD ADVECTION WIND FROM THE WESTERN OKLAHOMA COLD POOL, WHICH IS SOMETHING YOU DON`T SEE EVERY DAY. THIS IS VERY HIGH-RELATIVE HUMIDITY AIR AS THE TEMPERATURE-DEWPOINT SPREADS DOWN THERE IN THE COLD POOL ARE BASICALLY 0 OR 1 DEGREE FAHRENHEIT...EVEN AT DIURNAL MAXIMUM. ON THE SOUTHEAST WINDS...THIS AIRMASS WILL MOVE INTO THE SOUTHERN AND SOUTHEASTERN SECTIONS OF THE DDC FORECAST AREA. ALL SHORT-RANGE MODELS ARE VERY AGGRESSIVE AT DENSE FOG FORMATION AFTER 03Z AND BASED ON THE OBSERVATIONS THIS AFTERNOON UPSTREAM IN WESTERN OKLAHOMA...IT IS VERY JUSTIFIED. HAVE GONE AHEAD AND INSERTED DENSE FOG INTO THE GRIDS SOUTHEAST OF A LIBERAL TO CIMARRON TO LACROSSE LINE. THE PROBABILITY OF WIDESPREAD DENSE FOG IS A BIT LESS FARTHER NORTHWEST AND THE GENERATION OF PRECIPITATION AFTER MIDNIGHT MAY PRECLUDE WIDESPREAD DENSE FOG FORMATION NORTH OF THIS LINE. RAIN SHOWERS WILL DEVELOP ON INCREASING WARM ADVECTION AHEAD OF THE UPPER LOW AFTER ABOUT 04Z. THIS IS ABOUT THE TIME POPS WILL RAMP UP IN THE GRIDS FROM 20 PERCENT TO ABOUT 60 PERCENT OVERNIGHT. ALL THE MODEL SOUNDINGS SUPPORT A SIGNIFICANT WARM LAYER ALOFT, ALBEIT DRY, EARLY ON. THE PRECIPITATION TYPE IS EXPECTED TO BE RAIN SHOWERS...HOWEVER THE SURFACE TEMPERATURE WILL BE DROPPING SLOWLY DOWN INTO THE MID 30S AND LIKELY STOPPING IN THE 33-36F RANGE ON INCREASING MOISTURE ADVECTION AND THE REALIZATION OF LOW STRATUS AND AREAS/WIDESPREAD FOG. AS A RESULT...THE UPDATED OFFICIAL FORECAST WILL REFLECT LIQUID PRECIPITATION (NOT FREEZING) FOR AREAS SOUTHEAST OF A SYRACUSE TO SCOTT CITY TO WAKEENEY LINE (THE ENTIRE DDC FORECAST AREA). THAT BEING SAID...SOME SCATTERED SLEET SHOWERS CANNOT BE RULED OUT...AND IN THE FAR WEST AND NORTHWEST WILL INCLUDE MENTION OF SLEET. TOMORROW...AS THE UPPER LOW APPROACHES...700MB FRONTOGENESIS WILL BE INCREASING...AND THE PRECIPITATION IS EXPECTED TO BECOME MORE STRATIFIED IN NATURE ALONG THE 700MB BAROCLINIC ZONE. THE BEST AREA FOR FRONTOGENETIC PRECIPITATION WILL BE FROM THE ELKHART-JOHNSON-SYRACUSE AREAS NORTHEAST TOWARD ULYSSES TO GARDEN CITY...AND EVENTUALLY BY AFTERNOON THE DIGHTON-NESS CITY-WAKEENEY AREAS. FARTHER SOUTH OF THIS AXIS...LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED AND POPS WILL BE IN THE 20-40 PERCENT RANGE. WITHIN THE ZONE OF 700MB FRONTOGENESIS...THE LOWER TROPOSPHERIC THERMAL PROFILES WILL BE COOLING TO SUPPORT SNOW AT THE SURFACE. AT AROUND DAYBREAK...THE SNOW LINE SHOULD EXTEND FROM ROUGHLY ELKHART TO LAKIN TO SCOTT CITY. BY LATE MORNING...THE RAIN IS EXPECTED TO CHANGE OVER TO SNOW ALONG ROUGHLY A HUGOTON TO CIMARRON TO NESS CITY AXIS...AND BY MID-AFTERNOON ALONG ROUGHLY A MINNEOLA TO LARNED LINE. SNOW INTENSITY WITHIN THE STRONGEST ZONE OF FRONTOGENESIS WILL LIKELY BE ABOUT A HALF INCH PER HOUR RATE, BUT THIS RATE SHOULD NOT LAST VERY LONG AT ANY ONE LOCATION. GIVEN WARM SURFACES AND DIURNAL TIMING OF THE EVENT...ROAD SURFACES WILL PROBABLY BE OKAY IN MOST AREAS. SLUSHY TO SPOTTY SNOWPACKED ROADS CAN BE EXPECTED IF THE SNOW RATES ARE MORE THAN EXPECTED AND/OR LAST LONGER THAN EXPECTED IN ANY ONE LOCATION FROM MID MORNING THROUGH LATE AFTERNOON. AN AVERAGE SNOWFALL ACCUMULATION TOTAL OF ONE HALF TO ONE INCH CONTINUES TO BE IN THE FORECAST BUT A FEW 2 INCH AMOUNTS WILL BE POSSIBLE...PARTICULARLY FARTHER NORTHWEST FROM ROUGHLY LAKIN TO DIGHTON TO WAKEENEY...AS THE MID LEVEL CYCLONE TRACKS FROM LIBERAL TO GREAT BEND DURING THE DAY. TOMORROW NIGHT...WHATEVER PRECIPITATION REMAINS EARLY IN THE EVENING WILL BE ACROSS THE FAR EASTERN COUNTIES AND EXITING QUICKLY...SO MUCH OF THIS TIME FRAME WILL BE TRANQUIL AS A SURFACE HIGH SETTLES IN AND WINDS DECREASE QUITE A BIT. LOW TEMPERATURE FORECAST IS A CHALLENGE AND A LOT WILL DEPEND ON HOW MUCH SNOW FELL AND ACCUMULATED. IF AN INCH OR TWO OF FRESH SNOWFALL STILL REMAINS ON THE GROUND AFTER SUNSET...THEN TEMPERATURES WILL SURELY FALL INTO THE UPPER TEENS...HOWEVER IF THERE IS A LOT OF MELT GOING ON AS THE SNOW FALLS WITH NOT MUCH LEFT ON THE GROUND BY SUNSET...THEN LOWS WILL BE WARMER (LOWER TO MID 20S). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 246 PM CST TUE FEB 14 2012 THURSDAY: WEDNESDAYS UPPER LEVEL WEATHER SYSTEM WILL BE MOVING WELL TO THE EAST OF THE FA ON THURSDAY WITH A FLAT MID TO UPPER LEVEL FLOW PATTERN LEFT IN ITS WAKE. AT THE SURFACE, HIGH PRESSURE WILL RIDGE ACROSS THE PLAINS. WITH SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED SYSTEM, WILL LEAVE THE FORECAST DRY FOR NOW. TEMPERATURES ON THURSDAY ARE EXPECTED TO BE FAIRLY NEAR CLIMO. FRIDAY/SATURDAY: KANSAS WILL BE IN THE MIDDLE BETWEEN AN UPPER LEVEL LOW MOVING ACROSS MEXICO AND A BROAD UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE UPPER MIDWEST SYSTEM WILL CAUSE THE WEAK TAIL END OF A COLD FRONT TO MOVE ACROSS THE STATE, RESULTING IN A WEAK WIND SHIFT. TEMPERATURES WILL MODERATE A BIT MORE BY THE END OF THE BUSINESS WEEK WITH LOW 50S DEG F EXPECTED. SUNDAY: HAVE KEPT THE ALLBLEND POPS SUNDAY NIGHT AS THE UPPER LEVEL FLOW TURNS MORE SOUTHWESTERLY AND A WARM AIR ADVECTION PATTERN ENSUES. THESE POPS ARE ASSOCIATED WITH A PASSING OF AN UPPER LEVEL SHORTWAVE TROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING. SUNDAY LOOKS TO BE BREEZY AS 850 HPA WINDS INCREASE TO AROUND 35 KT ON BOTH GFS/ECMWF PLUS DECENT LEE SURFACE TROUGHING AHEAD OF THE APPROACHING UL DISTURBANCE. HAVE INCREASED WINDS ABOVE THE ALLBLEND AS A RESULT. THE ECMWF IS LESS AMPLIFIED WITH THE WAVE THAN COMPARED TO THE GFS AND WITH SLIGHTLY WEAKER DYNAMICS GOING INTO MONDAY MORNING. THE HIGHEST POPS ARE ALONG INTERSTATE 70 AND LESS ACROSS SOUTH CENTRAL KANSAS. MONDAY ONWARDS: THE FORECAST BECOMES A BIT MUDDLED MONDAY AND PARTICULARLY INTO TUESDAY. BOTH THE GFS AND ECMWF SHOW A LARGE AND BAGGY TROUGH ACROSS THE PLAINS. THE ECMWF IS MORE BROAD WITH THE 500 HPA PATTERN THAN COMPARED TO THE GFS. THIS WOULD RESULT IN A DRY WESTERLY FLOW PATTERN ACROSS KANSAS...SOMETHING THAT IS NOT TOO CONDUCIVE TO BRINGING PRECIPITATION HERE. AS A RESULT, HAVE LIMITED POPS BELOW 15 PERCENT AND GONE WITH A DRY FORECAST FOR NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1050 PM CST TUE FEB 14 2012 LATEST NAM, RUC AND HRRR CONTINUES TO INDICATED A 700-900 METER DEEP LAYER OF LOW LEVEL MOISTURE SPREADING ACROSS MOST OF SOUTHWEST AND PORTIONS OF NORTH CENTRAL KANSAS OVERNIGHT. AS OF 05Z CIGS AT DDC WERE ALREADY AT 200FEET WITH A BKN DECK OF 300FT CIGS STARTING TO SPREAD INTO GCK. BUFR SOUNDINGS INDICATING THE BOTH DDC AND GCK HAVE THE POTENTIAL OF VSBYS TO FALL BELOW 1/4MILE EARLY THIS MORING. HAYS VSBYS WILL BE SLIGHTLY BETTER BUT LIFR CIGS STILL ARE ANTICIAPTED. DENSE FOG WLL BE THE MAIN HAZARD AT DDC OVERNIGHT BUT AT GCK AND HYS SOME LIGHT RAINSHOWERS WILL ALSO BE POSSIBLE AS 850MB WARM AIR ADVECTION IMPROVES. WIND SPEEDS OVERNIGHT AT ALL THREE TAF SITES WILL BE AT LESS THAN 10KTS. ON WEDNESDAY THE RAIN WILL CHANGE OVER TO SNOW AS THE ATMOSHERE COOLS AHEAD OF AN APPROACHING UPPER LEVEL TROUGH. AS THIS UPPER LEVEL TROUGH PASSES SOUTHWEST KANSAS/TEXAS PANHANDLE LATE IN THE DAY...SUBSIDENCE IS EXPECTED TO DEVELOP IN ITS WAKE AND AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BEGIN TO BUILD INTO THE AREA. THIS WILL RESULT IN CLEARING SKIES AND DECREASING WINDS...MAINLY AFTER 00Z THURSDAY. UNTIL THEN NORTH WINDS WILL DEVELOP DURING EARLY IN THE DAY WITH AFTERNOON WIND SPEEDS INCREASING TO AROUND 15 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 25 47 26 / 70 40 0 0 GCK 39 22 47 24 / 70 30 0 0 EHA 43 23 48 28 / 30 10 0 0 LBL 45 24 49 25 / 30 20 0 0 HYS 37 22 45 26 / 70 40 0 0 P28 47 28 49 28 / 40 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ030-031- 043>046-062>066-075>081-085>090. && $$ UPDATE...BURKE SHORT TERM...UMSCHEID LONG TERM....SUGDEN AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1109 PM CST TUE FEB 14 2012 .UPDATED AVIATION SECTION FOR THE 06Z TAFS... .SHORT TERM...(THIS EVENING THROUGH TOMORROW NIGHT) ISSUED AT 246 PM CST TUE FEB 14 2012 THE CHALLENGE IN THE FORECAST CONTINUES TO BE TEMPERATURES/PRECIPITATION TYPE AND WHERE THE HEAVIEST ACCUMULATION OF PRECIPITATION WILL OCCUR. TONIGHT...A SURFACE LOW WILL CONTINUE TO DEVELOP OVER FAR SOUTHEAST COLORADO THROUGH THE EVENING AND WINDS WILL CONTINUE TO RESPOND OUT OF THE SOUTHEAST. THIS WIND DIRECTION WILL ACTUALLY BE A COLD ADVECTION WIND FROM THE WESTERN OKLAHOMA COLD POOL, WHICH IS SOMETHING YOU DON`T SEE EVERY DAY. THIS IS VERY HIGH-RELATIVE HUMIDITY AIR AS THE TEMPERATURE-DEWPOINT SPREADS DOWN THERE IN THE COLD POOL ARE BASICALLY 0 OR 1 DEGREE FAHRENHEIT...EVEN AT DIURNAL MAXIMUM. ON THE SOUTHEAST WINDS...THIS AIRMASS WILL MOVE INTO THE SOUTHERN AND SOUTHEASTERN SECTIONS OF THE DDC FORECAST AREA. ALL SHORT-RANGE MODELS ARE VERY AGGRESSIVE AT DENSE FOG FORMATION AFTER 03Z AND BASED ON THE OBSERVATIONS THIS AFTERNOON UPSTREAM IN WESTERN OKLAHOMA...IT IS VERY JUSTIFIED. HAVE GONE AHEAD AND INSERTED DENSE FOG INTO THE GRIDS SOUTHEAST OF A LIBERAL TO CIMARRON TO LACROSSE LINE. THE PROBABILITY OF WIDESPREAD DENSE FOG IS A BIT LESS FARTHER NORTHWEST AND THE GENERATION OF PRECIPITATION AFTER MIDNIGHT MAY PRECLUDE WIDESPREAD DENSE FOG FORMATION NORTH OF THIS LINE. RAIN SHOWERS WILL DEVELOP ON INCREASING WARM ADVECTION AHEAD OF THE UPPER LOW AFTER ABOUT 04Z. THIS IS ABOUT THE TIME POPS WILL RAMP UP IN THE GRIDS FROM 20 PERCENT TO ABOUT 60 PERCENT OVERNIGHT. ALL THE MODEL SOUNDINGS SUPPORT A SIGNIFICANT WARM LAYER ALOFT, ALBEIT DRY, EARLY ON. THE PRECIPITATION TYPE IS EXPECTED TO BE RAIN SHOWERS...HOWEVER THE SURFACE TEMPERATURE WILL BE DROPPING SLOWLY DOWN INTO THE MID 30S AND LIKELY STOPPING IN THE 33-36F RANGE ON INCREASING MOISTURE ADVECTION AND THE REALIZATION OF LOW STRATUS AND AREAS/WIDESPREAD FOG. AS A RESULT...THE UPDATED OFFICIAL FORECAST WILL REFLECT LIQUID PRECIPITATION (NOT FREEZING) FOR AREAS SOUTHEAST OF A SYRACUSE TO SCOTT CITY TO WAKEENEY LINE (THE ENTIRE DDC FORECAST AREA). THAT BEING SAID...SOME SCATTERED SLEET SHOWERS CANNOT BE RULED OUT...AND IN THE FAR WEST AND NORTHWEST WILL INCLUDE MENTION OF SLEET. TOMORROW...AS THE UPPER LOW APPROACHES...700MB FRONTOGENESIS WILL BE INCREASING...AND THE PRECIPITATION IS EXPECTED TO BECOME MORE STRATIFIED IN NATURE ALONG THE 700MB BAROCLINIC ZONE. THE BEST AREA FOR FRONTOGENETIC PRECIPITATION WILL BE FROM THE ELKHART-JOHNSON-SYRACUSE AREAS NORTHEAST TOWARD ULYSSES TO GARDEN CITY...AND EVENTUALLY BY AFTERNOON THE DIGHTON-NESS CITY-WAKEENEY AREAS. FARTHER SOUTH OF THIS AXIS...LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED AND POPS WILL BE IN THE 20-40 PERCENT RANGE. WITHIN THE ZONE OF 700MB FRONTOGENESIS...THE LOWER TROPOSPHERIC THERMAL PROFILES WILL BE COOLING TO SUPPORT SNOW AT THE SURFACE. AT AROUND DAYBREAK...THE SNOW LINE SHOULD EXTEND FROM ROUGHLY ELKHART TO LAKIN TO SCOTT CITY. BY LATE MORNING...THE RAIN IS EXPECTED TO CHANGE OVER TO SNOW ALONG ROUGHLY A HUGOTON TO CIMARRON TO NESS CITY AXIS...AND BY MID-AFTERNOON ALONG ROUGHLY A MINNEOLA TO LARNED LINE. SNOW INTENSITY WITHIN THE STRONGEST ZONE OF FRONTOGENESIS WILL LIKELY BE ABOUT A HALF INCH PER HOUR RATE, BUT THIS RATE SHOULD NOT LAST VERY LONG AT ANY ONE LOCATION. GIVEN WARM SURFACES AND DIURNAL TIMING OF THE EVENT...ROAD SURFACES WILL PROBABLY BE OKAY IN MOST AREAS. SLUSHY TO SPOTTY SNOWPACKED ROADS CAN BE EXPECTED IF THE SNOW RATES ARE MORE THAN EXPECTED AND/OR LAST LONGER THAN EXPECTED IN ANY ONE LOCATION FROM MID MORNING THROUGH LATE AFTERNOON. AN AVERAGE SNOWFALL ACCUMULATION TOTAL OF ONE HALF TO ONE INCH CONTINUES TO BE IN THE FORECAST BUT A FEW 2 INCH AMOUNTS WILL BE POSSIBLE...PARTICULARLY FARTHER NORTHWEST FROM ROUGHLY LAKIN TO DIGHTON TO WAKEENEY...AS THE MID LEVEL CYCLONE TRACKS FROM LIBERAL TO GREAT BEND DURING THE DAY. TOMORROW NIGHT...WHATEVER PRECIPITATION REMAINS EARLY IN THE EVENING WILL BE ACROSS THE FAR EASTERN COUNTIES AND EXITING QUICKLY...SO MUCH OF THIS TIME FRAME WILL BE TRANQUIL AS A SURFACE HIGH SETTLES IN AND WINDS DECREASE QUITE A BIT. LOW TEMPERATURE FORECAST IS A CHALLENGE AND A LOT WILL DEPEND ON HOW MUCH SNOW FELL AND ACCUMULATED. IF AN INCH OR TWO OF FRESH SNOWFALL STILL REMAINS ON THE GROUND AFTER SUNSET...THEN TEMPERATURES WILL SURELY FALL INTO THE UPPER TEENS...HOWEVER IF THERE IS A LOT OF MELT GOING ON AS THE SNOW FALLS WITH NOT MUCH LEFT ON THE GROUND BY SUNSET...THEN LOWS WILL BE WARMER (LOWER TO MID 20S). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 246 PM CST TUE FEB 14 2012 THURSDAY: WEDNESDAYS UPPER LEVEL WEATHER SYSTEM WILL BE MOVING WELL TO THE EAST OF THE FA ON THURSDAY WITH A FLAT MID TO UPPER LEVEL FLOW PATTERN LEFT IN ITS WAKE. AT THE SURFACE, HIGH PRESSURE WILL RIDGE ACROSS THE PLAINS. WITH SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED SYSTEM, WILL LEAVE THE FORECAST DRY FOR NOW. TEMPERATURES ON THURSDAY ARE EXPECTED TO BE FAIRLY NEAR CLIMO. FRIDAY/SATURDAY: KANSAS WILL BE IN THE MIDDLE BETWEEN AN UPPER LEVEL LOW MOVING ACROSS MEXICO AND A BROAD UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE UPPER MIDWEST SYSTEM WILL CAUSE THE WEAK TAIL END OF A COLD FRONT TO MOVE ACROSS THE STATE, RESULTING IN A WEAK WIND SHIFT. TEMPERATURES WILL MODERATE A BIT MORE BY THE END OF THE BUSINESS WEEK WITH LOW 50S DEG F EXPECTED. SUNDAY: HAVE KEPT THE ALLBLEND POPS SUNDAY NIGHT AS THE UPPER LEVEL FLOW TURNS MORE SOUTHWESTERLY AND A WARM AIR ADVECTION PATTERN ENSUES. THESE POPS ARE ASSOCIATED WITH A PASSING OF AN UPPER LEVEL SHORTWAVE TROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING. SUNDAY LOOKS TO BE BREEZY AS 850 HPA WINDS INCREASE TO AROUND 35 KT ON BOTH GFS/ECMWF PLUS DECENT LEE SURFACE TROUGHING AHEAD OF THE APPROACHING UL DISTURBANCE. HAVE INCREASED WINDS ABOVE THE ALLBLEND AS A RESULT. THE ECMWF IS LESS AMPLIFIED WITH THE WAVE THAN COMPARED TO THE GFS AND WITH SLIGHTLY WEAKER DYNAMICS GOING INTO MONDAY MORNING. THE HIGHEST POPS ARE ALONG INTERSTATE 70 AND LESS ACROSS SOUTH CENTRAL KANSAS. MONDAY ONWARDS: THE FORECAST BECOMES A BIT MUDDLED MONDAY AND PARTICULARLY INTO TUESDAY. BOTH THE GFS AND ECMWF SHOW A LARGE AND BAGGY TROUGH ACROSS THE PLAINS. THE ECMWF IS MORE BROAD WITH THE 500 HPA PATTERN THAN COMPARED TO THE GFS. THIS WOULD RESULT IN A DRY WESTERLY FLOW PATTERN ACROSS KANSAS...SOMETHING THAT IS NOT TOO CONDUCIVE TO BRINGING PRECIPITATION HERE. AS A RESULT, HAVE LIMITED POPS BELOW 15 PERCENT AND GONE WITH A DRY FORECAST FOR NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1050 PM CST TUE FEB 14 2012 LATEST NAM, RUC AND HRRR CONTINUES TO INDICATED A 700-900 METER DEEP LAYER OF LOW LEVEL MOISTURE SPREADING ACROSS MOST OF SOUTHWEST AND PORTIONS OF NORTH CENTRAL KANSAS OVERNIGHT. AS OF 05Z CIGS AT DDC WERE ALREADY AT 200FEET WITH A BKN DECK OF 300FT CIGS STARTING TO SPREAD INTO GCK. BUFR SOUNDINGS INDICATING THE BOTH DDC AND GCK HAVE THE POTENTIAL OF VSBYS TO FALL BELOW 1/4MILE EARLY THIS MORING. HAYS VSBYS WILL BE SLIGHTLY BETTER BUT LIFR CIGS STILL ARE ANTICIAPTED. DENSE FOG WLL BE THE MAIN HAZARD AT DDC OVERNIGHT BUT AT GCK AND HYS SOME LIGHT RAINSHOWERS WILL ALSO BE POSSIBLE AS 850MB WARM AIR ADVECTION IMPROVES. WIND SPEEDS OVERNIGHT AT ALL THREE TAF SITES WILL BE AT LESS THAN 10KTS. ON WEDNESDAY THE RAIN WILL CHANGE OVER TO SNOW AS THE ATMOSHERE COOLS AHEAD OF AN APPROACHING UPPER LEVEL TROUGH. AS THIS UPPER LEVEL TROUGH PASSES SOUTHWEST KANSAS/TEXAS PANHANDLE LATE IN THE DAY...SUBSIDENCE IS EXPECTED TO DEVELOP IN ITS WAKE AND AN AREA OF HIGH PRESSURE AT THE SURFACE WILL BEGIN TO BUILD INTO THE AREA. THIS WILL RESULT IN CLEARING SKIES AND DECREASING WINDS...MAINLY AFTER 00Z THURSDAY. UNTIL THEN NORTH WINDS WILL DEVELOP DURING EARLY IN THE DAY WITH AFTERNOON WIND SPEEDS INCREASING TO AROUND 15 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 34 38 25 47 / 40 70 40 0 GCK 34 38 22 47 / 60 70 30 0 EHA 30 43 23 48 / 30 30 10 0 LBL 33 45 24 49 / 20 30 20 0 HYS 31 36 22 45 / 60 70 40 0 P28 34 47 28 49 / 20 40 20 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST WEDNESDAY FOR KSZ063>066- 077>081-087>090. && $$ UPDATE...BURGERT SHORT TERM...UMSCHEID LONG TERM....SUGDEN AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1035 PM CST TUE FEB 14 2012 .UPDATE... ISSUED AT 1032 PM CST TUE FEB 14 2012 A SOUTHEAST FLOW CONTINUES TO DRAW LOW LEVEL MOISTURE BACK INTO SOUTHWEST KANSAS. NEW 00Z NAM BURF SOUNDINGS INDICATING THE POTENTIAL FOR DENSE FOG NOW AS FAR WEST AS GARDEN CITY. GIVEN THE UPSLOPE FLOW AND HIGHER DEWPOINTS CURRENTLY SPREADING INTO THE GARDEN CITY VICINITY UNDER CLEAR SKIES HAVE DECIDED TO EXPAND THE DENSE FOG ADVISORY SEVERAL COUNTIES FURTHER WEST. FURTHER NORTH, NEAR HAYS, THE MODEL SOUNDINGS APPEAR LESS FAVORABLE FOR DENSE FOG ALTHOUGH STATUS ALSO IS LIKELY. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW NIGHT) ISSUED AT 246 PM CST TUE FEB 14 2012 THE CHALLENGE IN THE FORECAST CONTINUES TO BE TEMPERATURES/PRECIPITATION TYPE AND WHERE THE HEAVIEST ACCUMULATION OF PRECIPITATION WILL OCCUR. TONIGHT...A SURFACE LOW WILL CONTINUE TO DEVELOP OVER FAR SOUTHEAST COLORADO THROUGH THE EVENING AND WINDS WILL CONTINUE TO RESPOND OUT OF THE SOUTHEAST. THIS WIND DIRECTION WILL ACTUALLY BE A COLD ADVECTION WIND FROM THE WESTERN OKLAHOMA COLD POOL, WHICH IS SOMETHING YOU DON`T SEE EVERY DAY. THIS IS VERY HIGH-RELATIVE HUMIDITY AIR AS THE TEMPERATURE-DEWPOINT SPREADS DOWN THERE IN THE COLD POOL ARE BASICALLY 0 OR 1 DEGREE FAHRENHEIT...EVEN AT DIURNAL MAXIMUM. ON THE SOUTHEAST WINDS...THIS AIRMASS WILL MOVE INTO THE SOUTHERN AND SOUTHEASTERN SECTIONS OF THE DDC FORECAST AREA. ALL SHORT-RANGE MODELS ARE VERY AGGRESSIVE AT DENSE FOG FORMATION AFTER 03Z AND BASED ON THE OBSERVATIONS THIS AFTERNOON UPSTREAM IN WESTERN OKLAHOMA...IT IS VERY JUSTIFIED. HAVE GONE AHEAD AND INSERTED DENSE FOG INTO THE GRIDS SOUTHEAST OF A LIBERAL TO CIMARRON TO LACROSSE LINE. THE PROBABILITY OF WIDESPREAD DENSE FOG IS A BIT LESS FARTHER NORTHWEST AND THE GENERATION OF PRECIPITATION AFTER MIDNIGHT MAY PRECLUDE WIDESPREAD DENSE FOG FORMATION NORTH OF THIS LINE. RAIN SHOWERS WILL DEVELOP ON INCREASING WARM ADVECTION AHEAD OF THE UPPER LOW AFTER ABOUT 04Z. THIS IS ABOUT THE TIME POPS WILL RAMP UP IN THE GRIDS FROM 20 PERCENT TO ABOUT 60 PERCENT OVERNIGHT. ALL THE MODEL SOUNDINGS SUPPORT A SIGNIFICANT WARM LAYER ALOFT, ALBEIT DRY, EARLY ON. THE PRECIPITATION TYPE IS EXPECTED TO BE RAIN SHOWERS...HOWEVER THE SURFACE TEMPERATURE WILL BE DROPPING SLOWLY DOWN INTO THE MID 30S AND LIKELY STOPPING IN THE 33-36F RANGE ON INCREASING MOISTURE ADVECTION AND THE REALIZATION OF LOW STRATUS AND AREAS/WIDESPREAD FOG. AS A RESULT...THE UPDATED OFFICIAL FORECAST WILL REFLECT LIQUID PRECIPITATION (NOT FREEZING) FOR AREAS SOUTHEAST OF A SYRACUSE TO SCOTT CITY TO WAKEENEY LINE (THE ENTIRE DDC FORECAST AREA). THAT BEING SAID...SOME SCATTERED SLEET SHOWERS CANNOT BE RULED OUT...AND IN THE FAR WEST AND NORTHWEST WILL INCLUDE MENTION OF SLEET. TOMORROW...AS THE UPPER LOW APPROACHES...700MB FRONTOGENESIS WILL BE INCREASING...AND THE PRECIPITATION IS EXPECTED TO BECOME MORE STRATIFIED IN NATURE ALONG THE 700MB BAROCLINIC ZONE. THE BEST AREA FOR FRONTOGENETIC PRECIPITATION WILL BE FROM THE ELKHART-JOHNSON-SYRACUSE AREAS NORTHEAST TOWARD ULYSSES TO GARDEN CITY...AND EVENTUALLY BY AFTERNOON THE DIGHTON-NESS CITY-WAKEENEY AREAS. FARTHER SOUTH OF THIS AXIS...LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED AND POPS WILL BE IN THE 20-40 PERCENT RANGE. WITHIN THE ZONE OF 700MB FRONTOGENESIS...THE LOWER TROPOSPHERIC THERMAL PROFILES WILL BE COOLING TO SUPPORT SNOW AT THE SURFACE. AT AROUND DAYBREAK...THE SNOW LINE SHOULD EXTEND FROM ROUGHLY ELKHART TO LAKIN TO SCOTT CITY. BY LATE MORNING...THE RAIN IS EXPECTED TO CHANGE OVER TO SNOW ALONG ROUGHLY A HUGOTON TO CIMARRON TO NESS CITY AXIS...AND BY MID-AFTERNOON ALONG ROUGHLY A MINNEOLA TO LARNED LINE. SNOW INTENSITY WITHIN THE STRONGEST ZONE OF FRONTOGENESIS WILL LIKELY BE ABOUT A HALF INCH PER HOUR RATE, BUT THIS RATE SHOULD NOT LAST VERY LONG AT ANY ONE LOCATION. GIVEN WARM SURFACES AND DIURNAL TIMING OF THE EVENT...ROAD SURFACES WILL PROBABLY BE OKAY IN MOST AREAS. SLUSHY TO SPOTTY SNOWPACKED ROADS CAN BE EXPECTED IF THE SNOW RATES ARE MORE THAN EXPECTED AND/OR LAST LONGER THAN EXPECTED IN ANY ONE LOCATION FROM MID MORNING THROUGH LATE AFTERNOON. AN AVERAGE SNOWFALL ACCUMULATION TOTAL OF ONE HALF TO ONE INCH CONTINUES TO BE IN THE FORECAST BUT A FEW 2 INCH AMOUNTS WILL BE POSSIBLE...PARTICULARLY FARTHER NORTHWEST FROM ROUGHLY LAKIN TO DIGHTON TO WAKEENEY...AS THE MID LEVEL CYCLONE TRACKS FROM LIBERAL TO GREAT BEND DURING THE DAY. TOMORROW NIGHT...WHATEVER PRECIPITATION REMAINS EARLY IN THE EVENING WILL BE ACROSS THE FAR EASTERN COUNTIES AND EXITING QUICKLY...SO MUCH OF THIS TIME FRAME WILL BE TRANQUIL AS A SURFACE HIGH SETTLES IN AND WINDS DECREASE QUITE A BIT. LOW TEMPERATURE FORECAST IS A CHALLENGE AND A LOT WILL DEPEND ON HOW MUCH SNOW FELL AND ACCUMULATED. IF AN INCH OR TWO OF FRESH SNOWFALL STILL REMAINS ON THE GROUND AFTER SUNSET...THEN TEMPERATURES WILL SURELY FALL INTO THE UPPER TEENS...HOWEVER IF THERE IS A LOT OF MELT GOING ON AS THE SNOW FALLS WITH NOT MUCH LEFT ON THE GROUND BY SUNSET...THEN LOWS WILL BE WARMER (LOWER TO MID 20S). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 246 PM CST TUE FEB 14 2012 THURSDAY: WEDNESDAYS UPPER LEVEL WEATHER SYSTEM WILL BE MOVING WELL TO THE EAST OF THE FA ON THURSDAY WITH A FLAT MID TO UPPER LEVEL FLOW PATTERN LEFT IN ITS WAKE. AT THE SURFACE, HIGH PRESSURE WILL RIDGE ACROSS THE PLAINS. WITH SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED SYSTEM, WILL LEAVE THE FORECAST DRY FOR NOW. TEMPERATURES ON THURSDAY ARE EXPECTED TO BE FAIRLY NEAR CLIMO. FRIDAY/SATURDAY: KANSAS WILL BE IN THE MIDDLE BETWEEN AN UPPER LEVEL LOW MOVING ACROSS MEXICO AND A BROAD UPPER LEVEL SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST. THE UPPER MIDWEST SYSTEM WILL CAUSE THE WEAK TAIL END OF A COLD FRONT TO MOVE ACROSS THE STATE, RESULTING IN A WEAK WIND SHIFT. TEMPERATURES WILL MODERATE A BIT MORE BY THE END OF THE BUSINESS WEEK WITH LOW 50S DEG F EXPECTED. SUNDAY: HAVE KEPT THE ALLBLEND POPS SUNDAY NIGHT AS THE UPPER LEVEL FLOW TURNS MORE SOUTHWESTERLY AND A WARM AIR ADVECTION PATTERN ENSUES. THESE POPS ARE ASSOCIATED WITH A PASSING OF AN UPPER LEVEL SHORTWAVE TROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING. SUNDAY LOOKS TO BE BREEZY AS 850 HPA WINDS INCREASE TO AROUND 35 KT ON BOTH GFS/ECMWF PLUS DECENT LEE SURFACE TROUGHING AHEAD OF THE APPROACHING UL DISTURBANCE. HAVE INCREASED WINDS ABOVE THE ALLBLEND AS A RESULT. THE ECMWF IS LESS AMPLIFIED WITH THE WAVE THAN COMPARED TO THE GFS AND WITH SLIGHTLY WEAKER DYNAMICS GOING INTO MONDAY MORNING. THE HIGHEST POPS ARE ALONG INTERSTATE 70 AND LESS ACROSS SOUTH CENTRAL KANSAS. MONDAY ONWARDS: THE FORECAST BECOMES A BIT MUDDLED MONDAY AND PARTICULARLY INTO TUESDAY. BOTH THE GFS AND ECMWF SHOW A LARGE AND BAGGY TROUGH ACROSS THE PLAINS. THE ECMWF IS MORE BROAD WITH THE 500 HPA PATTERN THAN COMPARED TO THE GFS. THIS WOULD RESULT IN A DRY WESTERLY FLOW PATTERN ACROSS KANSAS...SOMETHING THAT IS NOT TOO CONDUCIVE TO BRINGING PRECIPITATION HERE. AS A RESULT, HAVE LIMITED POPS BELOW 15 PERCENT AND GONE WITH A DRY FORECAST FOR NOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 524 PM CST TUE FEB 14 2012 HIGH CLOUDS WILL CONTINUE TO THICKEN AND LOWER ACROSS SOUTHWEST KANSAS THIS EVENING AS AN UPPER LEVEL LOW MOVES EAST ACROSS EASTERN ARIZONIA/FAR WESTERN NEW MEXICO. THERE MAY EVEN BE A FEW SHOWERS DEVELOPING TOWARDS MIDNIGHT AT HAYS AS 850MB WARM AIR ADVECTION IMPROVES. TEMPERATURE PROFILES AT HAYS INDICATED THE ATMOSHERE WILL BE WARM ENOUGH FOR MAINLY RAINSHOWERS EARLY TONIGHT BUT UNABLE TO RULE OUT A PERIOD OF SLEET AS THE ATMOSHERE BEGINS TO COOL EARLY WEDNESDAY MORNING. AS MID LEVEL FRONTOGENESIS IMPROVES ON EARLY WEDNESDAY THE PRECIPITATION CHANCES AT ALL TAF SITES WILL IMPROVE. RAIN CHANGIN TO SNOW WILL BE LIKELY AT ALL TERMINALS AFTER 12Z WEDNESDAY. A PERSISTANT SOUTHEAST FLOW AT THE SURFACE WILL DRAW HIGHER LOW LEVEL MOISTURE BACK INTO SOUTHWEST KANSAS EARLY TONIGHT. AS THE LOW LEVELS SATURATE...STATUS AND FOG STILL APPEARS LIKELY. LATEST HRRR AND RUC STILL POINTS AT DDC HAVING THE GREATEST POTENTIAL FOR DENSE FOG BUT VISIBLITIES FALLING TO LESS THAN ONE MILE AT TIMES AT GCK AND HYS. THE ONSET OF THE LOW STATUS AND FOG IS EXPECTED TO SPREAD INTO THE DDC AREA BY 04Z WITH VSBYS FALLING TO LESS THAN ONE MILE BY MIDNIGHT AT GCK AND HYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 34 38 25 47 / 40 70 40 0 GCK 34 38 22 47 / 60 70 30 0 EHA 30 43 23 48 / 30 30 10 0 LBL 33 45 24 49 / 20 30 20 0 HYS 31 36 22 45 / 60 70 40 0 P28 34 47 28 49 / 20 40 20 0 && .DDC WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CST WEDNESDAY FOR KSZ066-078>081- 087>090. && $$ UPDATE...BURGERT SHORT TERM...UMSCHEID LONG TERM....SUGDEN AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
637 PM EST THU FEB 16 2012 .SYNOPSIS... PATCHES OF DRIZZLE AND DENSE FOG NEAR THE MOUNTAINS WILL LINGER OVERNIGHT, UNTIL MIDWEST HIGH PRESSURE BRINGS DRYING FRIDAY INTO SATURDAY. && .NEAR TERM /THROUGH FRIDAY/... HAVE ADDED MENTION OF AREAS OF DENSE FOG NEAR THE MOUNTAINS ALONG WITH PATCHY DRIZZLE AS FAR WEST AS THE OHIO LINE, BASED ON RECENT SURFACE DATA. HAVE ISSUED SPECIAL WEATHER STATEMENT PERTAINING TO HAZARD OF LOW VISIBILITY IN FOG NEAR THE MOUNTAINS AND ACROSS THE NORTH, AS FAR WEST AS VENANGO COUNTY PA. HAVE UPPED TEMPERATURES BY 2 DEGREES TIL 8 PM BASED ON RECENT SURFACE DATA, THEN SLOWED COOL DOWN TO NEAR FREEZING TEMPERATURES TOWARD MORNING, BASED ON HRRR AND NAM MODEL OUTPUT. IF DRIZZLE REMAINS OVER THE MOUNTAINS, IT CAN BECOME FREEZING DRIZZLE AFTER 2 AM. SUSPECT FOG COVERAGE MAY DECREASE LATE TONIGHT, ALTHOUGH THERE CAN STILL BE LOW VISIBILITY OVER HIGHER ELEVATIONS. RECENT NAM MODEL OUTPUT CONTINUES TO SHOW INCOMING HIGH PRESSURE PROVIDING DRYING FRIDAY WEST TO EAST ACROSS THE UPPER OHIO VALLEY. SO EXPECT THE DRIZZLE AND FOG OVER THE MOUNTAINS TO END FRIDAY MORNING, AND CLOUDS DECREASE TO YIELD AT LEAST PARTIAL SUNSHINE ALL LOCATIONS BY AFTERNOON. HIGHS FRIDAY AFTERNOON SHOULD BE SLIGHTLY WARMER THAN NORMAL, PER CONSENSUS OF RECENT NAM AND GFS MOS. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE EXITING EASTBOUND SHOULD STILL MAINTAIN DRY CONDITIONS FRIDAY NIGHT INTO SATURDAY. WEAK LOW PRESSURE PASSING THROUGH THE GREAT LAKES MAY BRUSH THE NORTH WITH LIGHT SNOW SATURDAY AFTERNOON. TEMPERATURES THROUGH THIS PERIOD WILL BE AROUND 5 DEGREES ABOVE NORMAL. SATURDAY NIGHT INTO SUNDAY...A WEEKEND SNOW EVENT FOR THE SOUTHEAST RIDGES APPEARS TO BE COMING INTO BETTER FOCUS NOW. NORTHERN AND SOUTHERN STREAM TROUGHS WILL PHASE AS THEY MOVE ACROSS THE TENNESSEE VALLEY AND MOVE INTO THE CAROLINAS. 12Z NAM/GFS RUNS HAVE TRENDED FURTHER NORTH WITH THE SURFACE LOW AND THE NORTHERN EXTENT OF ITS PRECIPITATION SHIELD. FOR SNOW AMOUNTS, THIS EVENT MAY NEED FUTURE WINTER STORM WATCHES AND WARNINGS, AS DETERMINISTIC MODELS SHOW THE POTENTIAL FOR HEAVY AMOUNTS OF WET SNOW ACROSS TUCKER AND GARRETT COUNTIES WITH THE LOWER END OF THE ENVELOPE POSSIBLE FOR PRESTON COUNTY. WITH THIS IN MIND, HAVE ADDED MENTION OF THIS TO THE HWO. FOR THE REMAINDER OF THE FORECAST AREA, THE NORTHERN EXTENT OF DEEPER MOISTURE WITH SNOW LOOKS TO REMAIN SOUTHEAST OF PITTSBURGH, WITH ONLY LIGHT ACCUMULATION IF ANY POSSIBLE FOR THESE LOCATIONS. OTHERWISE, A DRY FORECAST IS IN PLACE AS HIGH PRESSURE APPROACHES FROM THE UPPER MIDWEST. TEMPERATURES WILL BE A FEW DEGREES BELOW NORMAL THROUGH THIS PERIOD. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... STORM SYSTEM MOVING UP THE EAST COAST WILL WRAP UP SUNDAY NIGHT ALONG THE RIDGES. HIGH PRESSURE WILL THEN BRING DRY CONDITIONS FOR MONDAY INTO EARLY TUESDAY. MODEL DETAILS BECOME FUZZY BY TUESDAY NIGHT...BUT MULTIPLE WAVES WILL MOVE ACROSS THE EASTERN UNITED STATES FOR THE MIDDLE PART OF THE WORK WEEK. THIS UNSETTLED PATTERN WILL KEEP CHANCE POPS FOR THE REST OF THE FORECAST. DAYTIME TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL...WITH OVERNIGHT LOWS COLD ENOUGH TO ALLOW FOR THE POSSIBILITY OF SNOW EACH EVENING. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... PER RECENT SURFACE DATA, HAVE WILL MAINTAIN AREAS OF IFR IN STRATUS AND FOG ACROSS THE UPPER OHIO VALLEY. RECENT NAM MODEL OUTPUT AND GFS LAMP THEN SHOW LOW LEVEL DRYING ASSOCIATED WITH INCOMING HIGH PRESSURE, SHOWING A TREND LATE TONIGHT FOR STRATUS CEILINGS TO LIFT TO MVFR LEVELS, ALTHOUGH KDUJ AND KFKL MAY NOT REACH MVFR UNTIL 13Z. DAYTIME HEATING WILL HELP PROMOTE CLOUD DISSIPATION WITH VFR PREVALENT BY 16Z. OUTLOOK...FRIDAY THROUGH TUESDAY... EXPECT VFR CONDITIONS TO CONTINUE FRIDAY NIGHT INTO EARLY SATURDAY WITH HIGH PRESSURE OVERHEAD. LOW PRESSURE MOVING ACROSS THE EASTERN GREAT LAKES COULD CLIP NORTHERN TERMINALS WITH RESTRICTIONS SATURDAY AFTERNOON INTO SATURDAY NIGHT. A DEVELOPING LOW PRESSURE SYSTEM OFF THE ATLANTIC COAST COULD THEN CLIP SOUTHEASTERN TERMINALS SUCH AS KLBE AND KMGW SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE WILL THEN BRING VFR CONDITIONS FOR SUNDAY NIGHT INTO TUESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
157 PM EST WED FEB 15 2012 .SYNOPSIS... HIGH PRESSURE WILL SHIFT EAST OF THE AREA THIS EVENING. LOW PRESSURE IS FORECAST TO SPREAD MORE PRECIPITATION ACROSS THE UPPER OHIO VALLEY LATE TONIGHT INTO THURSDAY. && .NEAR TERM /THROUGH THURSDAY/... 19Z RUC ANALYSIS INDICATES A WEAK 500MB RIDGE ACROSS THE UPPER OHIO VALLEY WITH MID-LEVEL MOISTURE SLIDING ACROSS THE RIDGE INTO THE AREA. 1000-850MB MOISTURE IS BEGINNING TO FINALLY ERODE NORTHEASTWARD WITH BREAKS IN CLOUD COVERAGE. AT THE SURFACE, HIGH PRESSURE EXTENDS FROM THE UPPER OHIO VALLEY INTO THE CAROLINAS. THIS AFTERNOON...HIGH PRESSURE AND WEAK RIDGING ALOFT WILL SHIFT EASTWARD ACROSS THE AREA AND KEEP THE FORECAST DRY FOR THE REMAINDER OF TODAY. THE RUC SUPPORTS THAT SKIES WILL GO PARTLY CLOUDY BRIEFLY BEFORE MID-LEVEL CLOUDS MOVE IN FROM THE WEST. FOR TEMPS, FORECAST IS CLOSEST TO A LAMP/HRRR BLEND WITH HIGHS RANGING FROM THE MID 30S NORTH OF I-80 TO THE LOWER 40S ACROSS PORTIONS OF EASTERN OHIO AND NORTH- CENTRAL WV. TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT A MID-LEVEL SHORT WAVE TROUGH AND ITS COINCIDENT SURFACE LOW WILL MOVE FROM THE CENTRAL PLAINS INTO THE OHIO VALLEY OVERNIGHT. A FRONTAL BOUNDARY WILL LIFT NORTHEAST OF THIS FEATURE ACROSS THE AREA, WITH ISENTROPIC UPLIFT IN THE 290-300K PROVIDING FORCING FOR AN AREA OF PRECIPITATION TO MOVE INTO THE AREA NEAR DAWN. CONSIDERING LAMP SURFACE TEMPS ALONG WITH SREF FZRA PROBS AND GFS/NAM MODEL SOUNDINGS, BELIEVE A BRIEF PERIOD OF FREEZING RAIN/SNOW MAY MIX IN WITH RAIN AT THE ONSET FOR AERAS NORTHEAST OF A FRANKLIN-DUBOIS LINE. THUS, CHC OF FREEZING RAIN IS FORECAST WITH A RAIN/SNOW MIX FOR THIS AREA. OVERNIGHT TEMPS WILL BE FAIRLY STEADY ACROSS THE AREA RANGING FROM THE LOWER 30S ALONG THE I-80 CORRIDOR TO THE UPPER 30S ACROSS NORTH-CENTRAL WV. THURSDAY...SURFACE TROUGH ALONG WITH A FRONTAL BOUNDARY WILL SLIDE ACROSS THE AREA, PROGGED TO BE ALONG THE EASTERN RIDGES BY 00Z FRIDAY. FORECAST IS A GFS/NAM BLEND, WITH ISENTROPIC LIFT PROVIDING RAIN THROUGH MUCH OF THE DAY AND QPF TOTALS OF A QUARTER TO A HALF OF AN INCH. TEMPS IN THE MORNING WILL QUICKLY WARM TO ABOVE FREEZING WITH PRECIP TYPE ALL RAIN. WEAK WARM AIR ADVECTION THROUGHOUT THE DAY WILL ALLOW FOR TEMPS TO WARM TO 5 TO 10 DEGREES ABOVE NORMAL. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/... BAROCLINIC ZONE WILL BE EXITING EASTERN SECTIONS OF THE CWA THURSDAY NIGHT. TIGHTENED POP AND SKY GRADIENTS TO BE MORE DETERMINISTIC WITH THE FORECAST. STILL EXPECTING A TRANSITION FROM RAIN TO SNOW FOR THE MTNS N INTO DUJ THURSDAY NIGHT...BUT NO SNOW ACCUMULATION. TRANSITORY SURFACE ANTICYCLONE YIELDS A HIGH CONFIDENCE FORECAST OF DRY WEATHER FRI AND SAT. ZONAL FLOW ALOFT BRINGS SLIGHTLY ABOVE NORMAL TEMPERATURES UNDER A MIXTURE OF CLOUDS AND SUNSHINE FRI AND SAT. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HIGHLIGHTS... - NO SIGNS OF ARCTIC AIR - LOTS OF UNCERTAINTY IN THE SAT NGT - SUN TIME RANGE - AT OR SLIGHTLY ABOVE NORMAL TEMPS NEXT WEEK LOTS OF SPREAD IN THE ENSEMBLES AS ALLUDED TO IN BULLETS ABOVE RIGHT OUT OF THE GATE. GEFS AND NAEFS MEANS KEEP SRN PLAINS SYSTEM FROM PHASING WITH THE NRN STREAM...THUS SHUNTING THE SFC LOW / QPF TO OUR S AND SE. OPERATIONAL GFS PHASES THE TWO BRANCHES BRINGING LOW PRESSURE UP E OF THE MTNS...WHICH WOULD MEAN THE POTENTIAL FOR SIGNIFICANT SNOW IN THE RIDGES S AND E OF PIT SAT NGT AND SUN. HOWEVER...LEFT INHERITED FORECAST FOR CONSISTENCY AND LEVERAGE ENSEMBLE MEANS WITH CHANCE POPS. PROB TOO LOW OF INCLUSION IN THE HAZARDOUS WEATHER OUTLOOK...BUT WE WILL CONTINUE TO MONITOR. MEDIUM CONFIDENCE WITH LESS MODEL SPREAD FOR EARLY NEXT WEEK. HIGH PRESSURE WILL CONTROL OUR WEATHER AS MID LVL HEIGHTS BUILD MON AND TUE. THE NEXT WEATHER SYSTEM SHOULD PASS TO OUR NW BRINGING ALL A LIQUID PTYPE...BUT IF TIMING CHANGES AND PCPN ONSET IS DURING THE NIGHT OR EARLY MRNG HRS...CAN NOT RULE BRIEF PERIOD OF A WINTRY MIX. TEMPERATURES WERE CONSTRUCTED USING THE BIAS CORRECTED MOSGUIDE. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... MVFR CEILINGS WILL BEGIN TO ERODE THIS EVENING FROM THE SOUTHWEST AS HIGH PRESSURE CROSSES THE AREA AND MID-LEVEL MOISTURE MOVES IN AHEAD OF THE NEXT SYSTEM. AFTER 00Z, PREVAILING VFR CONDITIONS CAN BE EXPECTED THROUGH THE PRE-DAWN HOURS. WINDS WILL GENERALLY REMAIN LIGHT AT 5-10KTS OUT OF THE W-SW SHIFTING MORE SOUTHEASTERLY LATE IN THE TAF PERIOD WITH THE APPROACH OF THE NEXT LOW PRESSURE SYSTEM. A FRONTAL BOUNDARY WILL PUSH NORTHEAST INTO THE AREA AND BRING SHOWERS TO THE TERMINALS AFTER 06Z. THERE IS A CHANCE OF A BRIEF PERIOD OF SNOW AND FREEZING RAIN TO MIX IN AT THE ONSET OF PRECIP AT KDUJ, ALTHOUGH CONFIDENCE IS TOO LOW AT THIS TIME TO MENTION IN THE TAF. RAIN WILL CONTINUE INTO THURSDAY AFTERNOON, WITH CEILINGS AND VISIBILITIES DROPPING BACK TO MVFR. THE SURFACE LOW WILL PULL EAST OF THE AREA TONIGHT WITH SHOWERS COMING TO AN END AS MVFR CEILINGS LINGER ACROSS THE TERMINALS. OUTLOOK...THURSDAY THROUGH MONDAY... CEILING RESTRICTIONS WILL CONTINUE THROUGH EARLY FRIDAY BEFORE IMPROVEMENT TO VFR IN HIGH PRESSURE FOR THE BEGINNING OF THE WEEKEND. ANOTHER SYSTEM PASSING TO THE SOUTHEAST MAY BRING RESTRICTIONS SOUTHEAST OF KPIT WITH SNOW LATE SATURDAY AND SUNDAY. HIGH PRESSURE WILL RETURN VFR CONDITIONS FOR EARLY NEXT WEEK. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1112 AM EST WED FEB 15 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE ACROSS THE AREA TODAY. LOW PRESSURE IS FORECAST TO SPREAD MORE PRECIPITATION ACROSS THE UPPER OHIO VALLEY LATE TONIGHT INTO THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... THE LATE MORNING ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO REMOVE MORNING DRIZZLE WORDING AND TO ADD THE SCHC OF FREEZING RAIN TOMORROW MORNING FOR AREAS NORTHEAST OF A FRANKLIN- DUBOIS LINE. 16Z RUC ANALYSIS INDICATES A WEAK 500MB RIDGE ACROSS THE OHIO VALLEY WITH MID-LEVEL MOISTURE SLIDING ACROSS THE RIDGE INTO THE AREA. 1000-850MB MOISTURE CONTINUES TO LINGER AND KEEP THE AREA CLOUDY AS IT REMAINS TRAPPED UNDER AN INVERSION. AT THE SURFACE, HIGH PRESSURE EXTENDS FROM THE UPPER OHIO VALLEY INTO THE CAROLINAS. THIS AFTERNOON...HIGH PRESSURE AND WEAK RIDGING ALOFT WILL SHIFT ACROSS THE AREA AND KEEP THE FORECAST DRY FOR THE REMAINDER OF TODAY. THE RUC SUPPORTS THAT SKIES WILL REMAIN MOSTLY CLOUDY AS STRATOCUMULUS IS SLOW TO ERODE UNDER A LINGERING INVERSION AT 850MB. EVEN IF ANY LOW-LEVEL CLOUD COVERAGE ERODES, MID-LEVEL CLOUDS MOVING IN FROM THE WEST WILL KEEP SKIES CLOUDY. FOR TEMPS, FORECAST IS CLOSEST TO A LAMP/HRRR BLEND WITH HIGHS RANGING FROM THE MID 30S NORTH OF I-80 TO THE MID 40S ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV. TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT A SHORT WAVE MID-LEVEL TROUGH AND ITS COINCIDENT SURFACE LOW WILL MOVE FROM THE CENTRAL PLAINS INTO THE OHIO VALLEY OVERNIGHT. A FRONTAL BOUNDARY WILL LIFT NORTHEAST OF THIS FEATURE ACROSS THE AREA, WITH ISENTROPIC UPLIFT IN THE 290-300K PROVIDING FORCING FOR AN AREA OF PRECIPITATION TO MOVE INTO THE AREA NEAR DAWN. CONSIDERING LAMP SURFACE TEMPS ALONG WITH SREF WINTER PROBS AND GFS/NAM MODEL SOUNDINGS, BELIEVE A BRIEF PERIOD OF FREEZING RAIN/SNOW MAY MIX IN WITH RAIN AT THE ONSET FOR AERAS NORTHEAST OF A FRANKLIN-DUBOIS LINE. THUS, SCHC OF FREEZING RAIN HAS BEEN ADDED TO RAIN/SNOW MIX FOR THIS AREA. OVERNIGHT TEMPS WILL BE FAIRLY STEADY ACROSS THE AREA RANGING FROM THE LOWER 30S ALONG THE I-80 CORRIDOR TO THE UPPER 30S ACROSS NORTH-CENTRAL WV. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... MODELS TRANSITION SURFACE LOW TO EASTERN GREAT LAKES DURING THE DAY THURSDAY WITH WEAK FRONT PUSHING ACROSS REGION LATE DAY. WIDESPREAD RAIN EXPECTED WITH ANY MIX ACROSS THE NORTH QUICKLY ENDING. COLD ADVECTION BEHIND THE FRONT THURSDAY NIGHT WILL BRING SCATTERED RAIN SHOWERS MIXING TO SNOW SHOWERS IN THE RIDGES BEFORE ENDING. 850MB TEMPERATURES ONLY REACH -6C AT BEST SO NO SIGNIFICANT LAKE SNOW OR UP-SLOPE EXPECTED. DRY AND SEASONAL FRIDAY UNDERNEATH HIGH PRESSURE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MODELS ARE IN GENL AGREEMENT IN DEPICTIONS OF THE LONG TERM PERIOD...BEGINNING WITH SPLIT FLOW VIA TROUGHING FM THE HUDSON BAY ACRS THE GREAT LAKES AND CLOSED LOW OVER NRN MEXICO. PTN IS THUS OF ZONAL FLOW ACRS THE REGION FOR THE PERIOD WITH PHASING TROUGHS OVR THE E COAST FOR THE START OF THE NEW WEEK. WITH NO DEEP MSTR TAP...AND SUPPORT LACKING IN FAST MOVING SHRTWVS IN THE CONFLUENT FLOW PROGGED OVR THE AREA...FORECAST WL FEATURE SUB CLIMO PRECIP PROBABILITIES AND NR NORMAL TEMPERATURES AND WL NOT BE FAR OFF HPC GUIDANCE. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... MVFR CEILINGS WILL PREVAIL AT ALL TAF SITES INTO THE EARLY AFTERNOON AS MOISTURE REMAINS TRAPPED UNDER AN INVERSION AT 3KFT. VFR CONDITIONS WILL RETURN LATE THIS AFTERNOON AS HIGH PRESSURE AND MID-LEVEL MOISTURE CROSSES THE AREA. WINDS WILL GENERALLY REMAIN LIGHT AT 5-10KTS OUT OF THE W-SW SHIFTING MORE SOUTHEASTERLY LATE IN THE TAF PERIOD WITH THE APPROACH OF THE NEXT LOW PRESSURE SYSTEM. OUTLOOK...THURSDAY THROUGH SUNDAY... RESTRICTIONS WILL ONCE AGAIN BE POSSIBLE THURSDAY AS A LOW PRESSURE SYSTEM BRINGS MAINLY RAIN TO THE REGION. RESTRICTIONS WILL CONTINUE THROUGH EARLY FRIDAY BEFORE IMPROVEMENT TO VFR IN HIGH PRESSURE FOR THE BEGINNING OF THE WEEKEND. ANOTHER SYSTEM MAY BRING RESTRICTIONS LATE SATURDAY AND SUNDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EST WED FEB 15 2012 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 425 PM EST WED FEB 15 2012 WV IMAGERY AND RUC ANALYSIS INDICATED SPLIT FLOW PATTERN WITH TROUGHING OVER THE WRN CONUS AND A FLAT RIDGE OVER THE EAST. ONE NRN STREAM SHORTWAVE TROUGH WAS LOCATED OVER NW MN WITH ANOTHER TRAILING OVER SRN SASK INTO NW ND. A VIGOROUS SRN STREAM SHRTWV MOVING FROM THE TX/OK PANHANDLE INTO SE KS. AT THE SFC...A WEAK TROUGH EXTENDED FROM NW ONTARIO THROUGH WRN MN LEAVING LIGHT SW FLOW OVER THE NRN GREAT LAKES. AN AREA OF LIGHT SNOW FROM SRN MN INTO WRN WI WAS SUPPORTED BY 290K-295K ISENTROPIC ASCENT AHEAD OF THE TROUGH. TONIGHT AND THU...RADAR TRENDS AND NAM ISENTROPIC PROGS SUGGEST THAT THE INITIAL AREAS OF PCPN WILL LIFT INTO THE SW CWA THIS EVENING. HOWEVER...WITH LITTLE INCREASE IN INTENSITY EXPECTED...ONLY MENTIONED CHANCE POPS WITH SNOW ACCUMULATION OF A HALF INCH OR LESS. AS THE LAGGING SHORTWAVE MOVES TOWARD THE UPPER MS VALLEY...INCREASING 700-300 MB QVECTOR CONV WITH THE DEEPENING MID LEVEL TROUGH WILL ALSO PROVIDE ADDITIONAL SUPPORT FOR AREAS OF LIGHT SNOW. AGAIN WITH ONLY MODERATE FORCING AND MOISTURE INFLOW...KEPT ONLY CHANCE POPS WITH SNOW ACCUMULATIONS LESS THAN AN INCH. HOWEVER...OVER THE ERN CWA...SLIGHTLY GREATER MOISTURE ADVECTION AND ISENTROPIC ASCENT SHOULD BE ENOUGH FOR MORE WIDESPREAD OR SLIGHTLY HEAVIER PCPN WITH SNOW AMOUNTS TO AROUND AN INCH. WITH DEWPOINTS REMAINING IN THE MID 20S OVER THE AREA...MIN TEMPS WILL REMAIN WELL ABOVE NORMAL...WITH READINGS ONLY FALLING INTO THE MID AND UPPER 20S. CLOUDS AND LIGHT PCPN SHOULD LIMIT MAX READINGS TO THE MID 30S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 425 PM EST WED FEB 15 2012 WE START THE PERIOD 00Z FRI WITH A 600MB SHORTWAVE TROUGH AXIS OVER THE ERN CWA...ANOTHER WEAKER SHORTWAVE OVER NRN MN...AND ANOTHER STRONGER SHORTWAVE JUST N OF MANITOBA. THIS RESULTS IN A BROAD...WEAK SFC LOW TO OUR NE...AND A WEAK SFC RIDGE OVER MN. WITH NW TO WNW LOW LEVEL WINDS...850MB TEMPS AROUND -10C...AND DEEP MOISTURE...EXPECT SOME LIGHT UPSLOPE SNOW OVER THE WRN CWA AND SOME LIGHT LAKE ENHANCED SNOW OVER THE ERN CWA AT THE START OF THE PERIOD. AS THE NRN MN SHORTWAVE MOVES INTO THE AREA LATE THU NIGHT...LES MAY BECOME A LITTLE MORE ORGANIZED. BY 12Z FRI...850MB TEMPS WILL HAVE DECREASED TO AROUND -12C WITH LOW LEVEL WINDS FROM THE NW TO WNW. WILL DECREASE POPS SOME AFTER THE INITIAL SHORTWAVE PASSAGE AT THE START OF THE PERIOD...THEN INCREASE POPS LATER THU NIGHT. STILL EXPECT NOTHING MORE THAN LIGHT LES...WITH MINOR ACCUMULATIONS OF LESS THAN AN INCH THROUGH THU NIGHT. 850MB TEMPS WILL CONTINUE TO STEADILY DECREASE FRI...AND BE DOWN TO -14C BY 00Z SAT...BUT SUBSIDENCE BEHIND THE THU NIGHT SHORTWAVE AND DAYTIME MIXING WILL LEAD TO LES NOT REALLY INCREASING MUCH THROUGH THE DAY. CHANCE POPS LOOK GOOD FOR FRIDAY IN THE NW TO WNW SNOWBELTS...WITH AROUND AN INCH OF ADDITIONAL SNOWFALL ACCUMULATIONS. FRI NIGHT AND SAT ARE MORE COMPLEX AND UNCERTAIN AS A STRONGER SHORTWAVE TROUGH MOVES OVER THE AREA. MODELS HAVE SHOWN BOTH RUN TO RUN AND MODEL TO MODEL DISAGREEMENT ON THE STRENGTH AND TIMING OF THE SHORTWAVE...WHICH HAS A BIG IMPACT ON PRECIP TIMING/COVERAGE. BESIDES THE OBVIOUS TIMING DIFFERENCES...ONE OF THE BIGGER DIFFERENCES BETWEEN THE MODELS RESULTS FROM THE STRENGTH OF THE SYSTEM. ALL MODELS BRING A DEEPENING SFC LOW SOMEWHERE S OF THE CWA...BUT THE EXACT TRACK OF THE LOW IS WHAT IS IN QUESTION. THE 12Z/15 GFS IS THE STRONGEST AND FARTHEST N WITH THE SFC LOW...WHICH WOULD BRING A COUPLE OF INCHES OF SNOW TO AREAS OF MENOMINEE COUNTY AND FAR ERN UPPER MI. THE GFS SOLUTION WOULD ALSO BRING LOW LEVEL WINDS FROM THE NNE...WHEREAS MOST OTHER MODELS SHOW NW TO NNW LOW LEVEL WINDS...WHICH WOULD MAKES FOR BIG DIFFERENCES IN LES. WILL NOT USE THE GFS SOLUTION SINCE IT IS MORE OF AN OUTLIER. THUS...WILL HAVE HIGH CHANCE TO LOW LIKELY POPS IN NNW TO NW WIND SNOWBELTS FRI NIGHT AND SAT...DIMINISHING LATE SAT AS SFC HIGH PRESSURE MOVES IN. DAYS 4 THROUGH 7 (SUNDAY THROUGH NEXT WEDNESDAY)... MODELS COME INTO BRIEF AGREEMENT AGAIN ON MON WITH AN UPPER LEVEL RIDGE OVER THE CWA. SFC HIGH PRESSURE E AND LOW PRESSURE W RESULTS IN WAA OVER THE AREA...WHICH WILL ALLOW HIGHS MON TO BE IN THE MID 30S. MODELS THEN DIVERGE SIGNIFICANTLY WITH SOLUTIONS FROM MON NIGHT THROUGH THE REST OF THE FORECAST PERIOD. MODELS SHOWS A COUPLE OF TROUGHS MOVING THROUGH...THE FIRST SOMETIME BETWEEN MON NIGHT THROUGH TUE NIGHT AND THE OTHER POSSIBLY MOVING INTO THE AREA SOMETIME LATE WED. SIGNIFICANT RUN TO RUN ERRORS AND MODEL DISAGREEMENT MAKE FOR LOW CONFIDENCE IN MODELS PAST MON. THE PERIOD SHOULD GENERALLY BE ABOVE NORMAL WITH RESPECT TO TEMPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1238 PM EST WED FEB 15 2012 EXTENSIVE LOW-LVL MOISTURE WILL REMAIN TRAPPED UNDER A SUBSIDENCE INVERSION THROUGH MUCH OF THE DAY ALLOWING FOR MVFR CIGS TO PERSIST AT KIWD/KSAW. AN AREA OF CLEARING INTO THE KEWEENAW IS EXPECTED TO FILL BACK IN WITH MVFR CIGS BY LATE AFTERNOON AS THE AREA OF MOISTURE LIFTS SLOWLY TO THE NORTH...PER SATELLITE TRENDS AND NAM/RUC SFC-850 MB RH FCST. TONIGHT...EXPECT CONDITIONS TO FALL INTO THE IFR RANGE WITH SOME LIGHT SNOW POSSIBLE AS A TROUGH MOVES THROUGH THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 425 PM EST WED FEB 15 2012 WRLY WINDS ARE EXPECTED TO INCREASE INTO THE 20 TO 30 KT RANGE THU INTO THU NIGHT IN THE WAKE OF A TROUGH MOVING THROUGH THE REGION. OTHERWISE...CONDITIONS WILL REMAIN RELATIVELY TRANQUIL THIS WEEK. LOW PRESSURE WILL CROSS THE GREAT LAKES THROUGH THE WEEKEND...AND WINDS WILL GENERALLY BE BELOW 20 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1208 AM EST WED FEB 15 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 418 PM EST TUE FEB 14 2012 WV IMAGERY AND RUC ANALYSIS INDICATED AN UPSTREAM MID/UPPER LEVEL SHORTWAVE TROUGH FROM THE ERN DAKOTAS INTO SRN MN. AT THE SFC...LOW PRES WAS LOCATED OVER SE NORTH DAKOTA. SO FAR..ONLY LIGHT SNOW OR FLURRIES WERE OBSERVED WITH THE SHRTWV OVER THE DAKOTAS. AHEAD OF THE LOW WEAK SW FLOW PREVAILED WITH ABUNDANT LOW LEVEL MOISTURE FROM WI INTO UPPER MI KEEPING LOW CLOUDS OVER THE REGION. WITH THE MILD AIRMASS OVER THE AREA...TEMPS HAD CLIMBED INTO THE LOWER TO MID 30S DESPITE THE PERSISTENT CLOUD COVER. TONIGHT INTO WEDNESDAY...MODELS SUGGEST MID LEVEL FGEN ASSOCIATED WITH THE DAKOTAS SHRTWV WILL SUPPORT AREAS OF LIGHT SNOW INTO NRN WI AND UPPER MI LATE TONIGHT INTO WED MORNING. THE FCST LEANS TOWARD THE 12Z/18Z NAM WITH THE GREATER FORCING/POPS INTO THE SW HALF OF THE CWA. THERE MAY BE SOME POTENTIAL FOR A PERIOD OF BRIEF HEAVIER SNOW...GIVEN THE STRENGTH OF THE FORCING. HOWEVER...SINCE THERE STILL SOME UNCERTAINTY IN WHERE ANY STRONGER PCPN BAND MAY OCCUR...ONLY CHANCE POPS WERE INCLUDED WITH OVERALL SNOWFALL AMOUNTS OF LESS THAN AN INCH. LOOK FOR MINS TONIGHT TO RANGE MAINLY IN THE LOWER 20S OVER THE WRN INTERIOR TO THE MID 20S NEAR THE GREAT LAKES AND EAST. HIGH TEMPS WILL AGAIN CLIMB ABOVE NORMAL...INTO THE MID AND UPPER 30S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 418 PM EST TUE FEB 14 2012 STRONG NORTHERN STREAM SHORTWAVE WILL NEAR THE GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY MORNING...PHASING WITH A SOUTHERN STREAM SHORTWAVE MOVING NORTHWEST FROM THE PLAINS. PREVIOUS MODEL RUNS WERE SHOWING SOME UNCERTAINTY IN THE INTENSITY AND LOCATION OF THIS PHASING...CAUSING DISCREPANCIES IN QPF AMOUNTS AND LOCATION OF THE SURFACE LOW ASSOCIATED WITH THE SOUTHERN STREAM. MOST RECENT RUNS OF GFS/NAM/ECMWF/GEM HAVE SEEM TO COME INTO BETTER AGREEMENT...WITH GENERAL CONSENSUS HAVING THE SURFACE LOW PRESSURE PASSING OVER LOWER MI BY EARLY AFTERNOON THURSDAY. DEEPEST MOISTURE WILL BE CONFINED NEAR THE CENTER OF THE LOW...BUT GOOD CONVERGENCE AND DECENT LAPSE RATES WILL MOVE INTO UPPER MI...ESPECIALLY EAST AS THE SOUTHERN SHORTWAVE MOVES FROM SOUTHWEST TO NORTHEAST...BRINGING CHANCES FOR PRECIP BEGINNING WEDNESDAY NIGHT SOUTH CENTRAL AND REMAINING DURING THE DAY THURSDAY ACROSS THE SOUTHEAST. NORTHERN WAVE ENERGY WILL KEEP THE LOW SUPPRESSED FAR ENOUGH SOUTH THAT MOST OF THE MOISTURE AND LIFT WILL BE CONFINED TO SOUTHEAST WI AND LOWER MI WHERE THE BEST WAA IS LOCATED...THOUGH 0Z GEM BRINGS SOME OF THE ASSOCIATED HIGHER QPF VALUES FARTHER NORTH ALONG LAKE MI IN UPPER MI AS WELL. WILL KEEP WITH HIGHEST QPF AND SNOWFALL TOTALS NEAR THE LAKE MI SHORELINE...BUT GOING WITH CONSENSUS...ONLY EXPECT SNOWFALL AMOUNTS TO REACH THE 3 TO 5 INCH RANGE IN THIS AREA. SURFACE LOW PRESSURE WILL QUICKLY MOVE OFF TO THE NORTHEAST BY THURSDAY EVENING...FOLLOWED SHORTLY THEREAFTER BY THE ASSOCIATED PHASED SHORTWAVE. DRY AIR WILL THEN INFILTRATE FROM WEST TO EAST...BRINGING AN END TO PRECIP CHANCES ACROSS THE INLAND AREAS. AS THIS TAKES PLACE...WINDS WILL SHIFT TO A PREDOMINATE NW DIRECTION AND STRENGTHEN BEHIND THE SHORTWAVE. COLDER H850 TEMPERATURES WILL THEN BEGIN FILTERING IN BY THE DAY FRIDAY...ALLOWING INSTABILITY AND LES CHANCES TO DEVELOP. DAYS 4 THROUGH 7 /FRIDAY NIGHT THROUGH TUESDAY/... AS THE GENERAL TROUGH PATTERN CONTINUES OVER THE NORTHEASTERN CONUS THROUGH THE WEEKEND...EXPECT A SERIES OF SHORTWAVES TO IMPACT THE UPPER GREAT LAKES DURING THIS TIME PERIOD. MODELS WILL CONTINUE HAVING VARYING SOLUTIONS ON TIMING AND LOCATION...WITH THE ECMWF CONTINUING TO BE THE MOST PROGRESSIVE. LES CHANCES WILL CONTINUE FRIDAY NIGHT AND THEN DURING THE DAY SATURDAY WITH 0Z ECMWF H850 TEMPS -15C ACROSS LAKE SUPERIOR AND PREDOMINATE NW WINDS DURING THE DAY. LINGERING LOW LEVEL MOISTURE WILL HELP KEEP LES EAST OF MUNISING WHERE NW WINDS WILL BE MAXIMIZED WITH THE FETCH OVER THE LAKE. INVERSION HEIGHTS WILL BE AROUND 6KFT...WITH THE BEST SNOW GROWTH JUST BELOW THIS LAYER. CAPE VALUES WILL MAX OUT AROUND 18Z SATURDAY...AS WILL THE LES PARAMETER. WITH LIGHT TO MODERATE WINDS...COULD EXPECT HIGHER END SNOW RATIOS IN THE UPPER TEENS TO LOW 20S. WILL CONTINUE WITH MIDNIGHT SHIFTS DECISION TO BUMP UP POPS IN NW WIND FAVORED AREAS DURING THIS TIME PERIOD. AS NEXT SHORTWAVE PASSES OVER SATURDAY NIGHT...EXPECT WINDS TO THEN SHIFT TO A MORE WESTERLY DIRECTION AND H850 TEMPS TO BEGIN INCREASING BY SUNDAY EVENING...THEREBY BRINGING AN END TO ANY LINGERING LES CHANCES. 0Z ECMWF/GFS THEN HAVE A SHORT LIVED RIDGE BUILDING IN ON MONDAY KEEPING CONDITIONS DRY DURING THE DAY. DECREASING CLOUDS DURING THIS TIME PERIOD SHOULD ALLOW HIGH TEMPERATURES TO RISE BACK INTO THE MID 30S. AS RIDGE LIES OVER THE UPPER GREAT LAKES ON MONDAY...A SHORTWAVE WILL BEGIN DEVELOPING OVER THE PLAINS. THIS WILL AMPLIFY THE RIDGE...WHILE ALSO CAUSING ITS QUICK EXIT TO THE NORTHEAST. SHORTWAVE WILL THEN REPLACE THE RIDGE AND BRING PRECIP CHANCES BY MONDAY NIGHT...WITH THE 0Z ECMWF KEEPING THE TRACK OF THIS SHORTWAVE ACROSS WI AND LOWER MI. WITH INCREASED CLOUD COVER AHEAD OF THIS SYSTEM...DON/T EXPECT LOW TEMPERATURES TO DROP MUCH...REMAINING IN THE 20S. ASSOCIATED LOW PRESSURE WILL REACH CROSS UPPER MI BY TUESDAY AFTERNOON...WITH PRECIP CHANCES CONTINUING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1207 AM EST WED FEB 15 2012 MVFR CIGS WILL PREVAIL OVERNIGHT AT IWD AND CMX. WILL TAKE A BIT LONGER TO GET THEM INTO SAW WITH A SLIGHT DOWNSLOPE DIRECTION HELPING TO SUPPRESS THEM A BIT. A LOW PRESSURE SYSTEM APPROACHING FROM THE NORTHERN PLAINS LATE TONIGHT SHOULD CONTINUE TO KEEP MVFR CIGS ACROSS THE REGION. THERE COULD BE A CHANCE OF SOME LIGHT SNOW LATE TONIGHT INTO EARLY WED MORNING. WHEN THE SNOW ARRIVES AT SAW...MVFR CIGS SHOULD ACCOMPANY THE SNOW. VFR CONDITIONS WILL RETURN IN THE EVENING AT IWD AND CMX WITH DRIER AIR MOVING IN. SAW WILL KEEP THE MVFR CIGS THROUGH THE WHOLE PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 PM EST TUE FEB 14 2012 A SERIES OF WEAK LOW PRESSURE TROUGHS MOVING THROUGH THE AREA WILL KEEP WINDS BELOW 20KTS TONIGHT THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS ON WED NIGHT WILL MOVE THROUGH THE GREAT LAKES REGION FROM THURSDAY INTO FRIDAY. THIS WILL LEAD TO NW WINDS UP TO 25KTS OVER ERN LK SUPERIOR. HIGH PRESSURE WILL THEN MOVE OVER THE AREA FOR THE FIRST PART OF THE WEEKEND AND KEEP WINDS BELOW 20KTS. WITH ABOVE NORMAL TEMPERATURES THROUGH THE PERIOD...LITTLE TO NO FREEZING SPRAY IS EXPECTED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...JMW AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1135 AM CST WED FEB 15 2012 .UPDATE... UPDATED TO INCLUDE 18Z AVIATION DISCUSSION. && .DISCUSSION... RATHER COMPLICATED UPPER AIR PATTERN IN PLACE WITH SATELLITE IMAGERY SHOWING MULTIPLE WEATHER DISTURBANCES AFFECTING THE AREA IN THE NEXT 24 HOURS. THE FIRST IS A VORT NOW WEAKENING AND SHEARING OUT OF CENTRAL MN AS IT MOVES ACROSS N WI. ASSOCIATED -SN WILL BE NORTH OF OUR AREA BY 12Z. A PAIR OF UPSTREAM VORTS LURK AHEAD IN THE DKTS WITH ANOTHER DIVING SE ACROSS SASK. THE MORE WELL DEFINED DKTS FEATURE IS IN W NODAK NEAR DIK WITH ANOTHER MOVING ACROSS W SODAK. BOTH HAVE LIGHT MIXED PCPN ASSOCIATED WITH THEM. THE 06Z NAM HAS PRETTY GOOD PLACEMENT OF BOTH OF THESE. SOME CONCERN FOR THE MORNING HOURS THAT THE SOUTHERN FEATURE MAY CARRY SOME LIGHT MIXED PCPN INTO OUR WESTERN COUNTIES...WHICH HRRR HAS BEEN ADVERTISING LAST FEW RUNS. PROGGED SOUNDINGS SHOW TEMP PROFILE WARM ENUF FOR LIQUID AT LEAST AS FAR N AS THE MVE AREA. IF PCPN HOLDS OFF UNTIL AROUND 15Z...SHUD BE MAINLY --RA AND --SN...BUT IF IT MOVES IN PRIOR TO THAT HAVE RISK OF --ZR. WITH LOWER LEVELS TAKING SOME TIME TO SATURATE...WON`T MENTION THE ZR THREAT. DURING THE AFTN THE BETTER FORCING THEN FOCUSED MORE TO OUR NORTH AS NODAK VORT LIFTS ACROSS N MN. CONFINED PCPN THEN TO JUST A S/C -SN IN SOME CENTRAL MN COUNTIES. WEDGE OF CLEAR SKIES ACROSS MUCH OF THE AREA ATTM WILL BE FILLING IN DURING THE MORNING AS UPSTREAM SYSTEMS APPROACH AREA. FOR TONIGHT...KEPT SMALL CHANCE OF --SN IN EASTERN AREAS...BUT FOCUS OF ANY SIG PCPN WILL BE WELL TO OUR SOUTH AS SHORTWAVE NOW IN NEW MEXICO LIFTS ACROSS THE CENTRAL U.S. INTO THE OHIO VALLEY. A LITTLE COOLER ON THURSDAY ACROSS EASTERN AREAS AS NW WINDS BRING IN A BIT OF COOLING BEHIND THE WEAK SURFACE TROF MOVING THRU TODAY. IN THE WEST...WEST WINDS AHEAD OF NEXT SYSTEM ALREADY BEGIN TO PULL WARMER AIR BACK IN. MILD THURSDAY NIGHT WITH SW WINDS AHEAD OF SURFACE LOW DROPPING ACROSS THE DAKOTAS INTO SW MN. NAM AN OUTLIER WITH SYSTEM DROPPING ACROSS THE AREA MUCH FASTER AND SFC WINDS NW ACROSS AREA BY 12Z FRIDAY. RETAINED CURRENT DRY FCST...BUT 00Z ECMWF IS SQUIRTING OUT SOME LIGHT QPF MAINLY SW OF MN RIVER INTO SC MN ON FRIDAY. A BIT COOLER ON SATURDAY BEHIND THIS SYSTEM. LOW TEMPS SATURDAY MORNING WITH BE TRICKY WITH MODELS SHOWING A FAIRLY WIDE RANGE IN POSITION OF SURFACE HIGH PRESSURE RANGING FROM SE MN ON NAM TO THE EASTERN DAKOTAS ON THE GFS. JURY STILL OUT ON THE MONDAY/MONDAY NIGHT SYSTEM. GFS HAS PROBABLY BEEN THE MOST CONSISTENT SHOWING POSSIBLE PCPN OF SIGNIFICANCE...BUT 00Z ECMWF IS BEGINNING TO TREND BACK TOWARD THE GFS. TRIMMED BACK ON THE AREA OF MIXED PCPN WITH MODEL TRENDS NOW FAVORING SURFACE LOW TRACK MORE ACROSS IOWA. && .AVIATION.../18Z TAF ISSUANCE/ WEAK LOW PRESSURE TROUGH CROSSING THE REGION THIS AFTN WITH A LOW PRES CENTER CROSSING FROM NE NEBRASKA INTO NW IOWA HAS A BATCH OF PRECIP AND MVFR CIGS AHEAD OF IT THAT WILL GRADUALLY PUSH THROUGH ALL TAF SITES THIS AFTN AND EVE. PRECIP IS LIGHT AND SPLOTCHY WHERE IT IS BEING REPORTED SO AM NOT LOOKING FOR A GREAT REDUCTION IN VSBY WHILE CIGS WILL LIKELY DROP INTO THE MVFR RANGE FOR A FEW HOURS. PRECIP CHCS ARE TOO LOW AND PRECIP INTENSITY IS TOO LOW TO GO WITH ANYTHING MORE BONAFIDE THAN VCSH SO AM THINKING THE VC MENTION SHOULD WORK QUITE WELL IN THIS CASE. ONCE THE PRECIP ENDS...CLOUDS WILL GRADUALLY RISE AND THIN OUT...LEADING TO GENERALLY VFR CONDITIONS LATE TONIGHT THROUGH MIDDAY TMRW. WITH LIGHTER WINDS AND GOOD CLEARING...THERE IS A CHC THAT THE MORE FAVORABLE FOG SITES /INCLUDING KEAU AND KRNH/ MAY HAVE SOME MVFR VSBY DURING THE PRE- DAWN HOURS. MSP...NOT MANY CHANGES TO THE PREVIOUS TAF SET OTHER THAN TWEAKING THE TIMING OF VCSH AND TO INCLUDE A TEMPO PERIOD OF MVFR CIGS WITH THE OVERHEAD MOVEMENT OF THE PRECIP ACRS THE FIELD. NOT EXPECTING ANY CIGS BELOW 2 KFT THROUGHOUT THIS EVENT. CONDS IMPROVE BY LATE EVENING TO VFR. HAVE BROUGHT VSBY DOWN TO 6SM TO INDICATE THE CHC THAT VSBY COULD DROP INTO MVFR RANGE BUT AM NOT EXPECTING IT ATTM. VFR CONDS THEN PREVAIL THRU TMRW. OUTLOOK... /THU/...VFR. /FRI/...A WEAK LOW PRES SYSTEM WILL DROP THROUGH BUT WITH NEGLIGIBLE EFFECTS. VFR CONDS WILL PREVAIL BUT SOME MVFR CIGS CANNOT BE RULED OUT...ESP OVER ERN MN INTO WRN WI. /SAT-SUN/...VFR. /MON/...DEGRADED CONDITIONS POSSIBLE AS AN ORGANIZED STORM SYSTEM DEVELOPS OVER THE SOUTHWEST AND MOVES THROUGH THE PLAINS. MUCH UNCERTAINTY WITH TRACK AND IMPACTS ATTM. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
606 AM CST WED FEB 15 2012 .UPDATE... 12Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... RATHER COMPLICATED UPPER AIR PATTERN IN PLACE WITH SATELLITE IMAGERY SHOWING MULTIPLE WEATHER DISTURBANCES AFFECTING THE AREA IN THE NEXT 24 HOURS. THE FIRST IS A VORT NOW WEAKENING AND SHEARING OUT OF CENTRAL MN AS IT MOVES ACROSS N WI. ASSOCIATED -SN WILL BE NORTH OF OUR AREA BY 12Z. A PAIR OF UPSTREAM VORTS LURK AHEAD IN THE DKTS WITH ANOTHER DIVING SE ACROSS SASK. THE MORE WELL DEFINED DKTS FEATURE IS IN W NODAK NEAR DIK WITH ANOTHER MOVING ACROSS W SODAK. BOTH HAVE LIGHT MIXED PCPN ASSOCIATED WITH THEM. THE 06Z NAM HAS PRETTY GOOD PLACEMENT OF BOTH OF THESE. SOME CONCERN FOR THE MORNING HOURS THAT THE SOUTHERN FEATURE MAY CARRY SOME LIGHT MIXED PCPN INTO OUR WESTERN COUNTIES...WHICH HRRR HAS BEEN ADVERTISING LAST FEW RUNS. PROGGED SOUNDINGS SHOW TEMP PROFILE WARM ENUF FOR LIQUID AT LEAST AS FAR N AS THE MVE AREA. IF PCPN HOLDS OFF UNTIL AROUND 15Z...SHUD BE MAINLY --RA AND --SN...BUT IF IT MOVES IN PRIOR TO THAT HAVE RISK OF --ZR. WITH LOWER LEVELS TAKING SOME TIME TO SATURATE...WON`T MENTION THE ZR THREAT. DURING THE AFTN THE BETTER FORCING THEN FOCUSED MORE TO OUR NORTH AS NODAK VORT LIFTS ACROSS N MN. CONFINED PCPN THEN TO JUST A S/C -SN IN SOME CENTRAL MN COUNTIES. WEDGE OF CLEAR SKIES ACROSS MUCH OF THE AREA ATTM WILL BE FILLING IN DURING THE MORNING AS UPSTREAM SYSTEMS APPROACH AREA. FOR TONIGHT...KEPT SMALL CHANCE OF --SN IN EASTERN AREAS...BUT FOCUS OF ANY SIG PCPN WILL BE WELL TO OUR SOUTH AS SHORTWAVE NOW IN NEW MEXICO LIFTS ACROSS THE CENTRAL U.S. INTO THE OHIO VALLEY. A LITTLE COOLER ON THURSDAY ACROSS EASTERN AREAS AS NW WINDS BRING IN A BIT OF COOLING BEHIND THE WEAK SURFACE TROF MOVING THRU TODAY. IN THE WEST...WEST WINDS AHEAD OF NEXT SYSTEM ALREADY BEGIN TO PULL WARMER AIR BACK IN. MILD THURSDAY NIGHT WITH SW WINDS AHEAD OF SURFACE LOW DROPPING ACROSS THE DAKOTAS INTO SW MN. NAM AN OUTLIER WITH SYSTEM DROPPING ACROSS THE AREA MUCH FASTER AND SFC WINDS NW ACROSS AREA BY 12Z FRIDAY. RETAINED CURRENT DRY FCST...BUT 00Z ECMWF IS SQUIRTING OUT SOME LIGHT QPF MAINLY SW OF MN RIVER INTO SC MN ON FRIDAY. A BIT COOLER ON SATURDAY BEHIND THIS SYSTEM. LOW TEMPS SATURDAY MORNING WITH BE TRICKY WITH MODELS SHOWING A FAIRLY WIDE RANGE IN POSITION OF SURFACE HIGH PRESSURE RANGING FROM SE MN ON NAM TO THE EASTERN DAKOTAS ON THE GFS. JURY STILL OUT ON THE MONDAY/MONDAY NIGHT SYSTEM. GFS HAS PROBABLY BEEN THE MOST CONSISTENT SHOWING POSSIBLE PCPN OF SIGNIFICANCE...BUT 00Z ECMWF IS BEGINNING TO TREND BACK TOWARD THE GFS. TRIMMED BACK ON THE AREA OF MIXED PCPN WITH MODEL TRENDS NOW FAVORING SURFACE LOW TRACK MORE ACROSS IOWA. && .AVIATION.../12Z TAF ISSUANCE/ MESSY UPPER AIR CHART THIS MORNING...WITH SHORTWAVES CURRENTLY OVER THE TX PANHANDLE...AND CENTRAL SODAK AND NODAK. PRECIP ASSOCIATED WITH THE SRN WAVE WILL STAY ACROSS IA/IL AND THE NRN WAVE WILL RUN SNOW ALONG THE INTL BORDER. THE SODAK WAVE IS THE WEAKEST OF THE THREE AND WILL BE IMPACTING THE THE MPX TERMINALS WITH MAINLY LOW VFR CIGS. SATURATION LOOKS QUESTIONABLE...AND DO NOT EXPECT MUCH MORE THAN SOME PASSING SPRINKLES WITH THIS WAVE. ALTHOUGH A FEW FZRA REPORTS ARE SHOWING UP ACROSS ERN SODAK...HI-RES REFLECTIVITY FORECASTS DRY THIS PRECIP UP AS IT HEADS INTO MN. FORECAST SOUNDINGS TODAY INDICATING ANY PRECIP THAT DOES FALL WOULD MOST LIKELY BE IN THE LIQUID FORM. LOOKING AT OBS ACROSS SODAK...WILL PROBABLY SEE SOME MVFR CONDITIONS TODAY...BUT LOOKS LIKE NOTHING MORE THAN A TEMPORARY BASIS AT THE MOMENT...WITH MOST WIDESPREAD MVFR CONDS GOING ACROSS NRN MN. SEEING GOOD DRYING ACROSS WRN SODAK BEHIND THIS WAVE...AND RH PROFILES SUGGEST THIS TREND WILL CONTINUE OVER HERE TONIGHT. WILL HAVE TO AGAIN WATCH FOR BR/HZ LATE TONIGHT ACROSS ERN MN/WRN WI...WHERE DEWP DEPRESSIONS ARE AGAIN PROGGED TO BE LESS THAN 2 DEGS. KMSP...VFR CONDITIONS WILL PREVAIL MOST OF THIS PERIOD...ONLY EXCEPTION BEING WHEN UPPER WAVE MOVES THROUGH AROUND 00Z. MAY SEE A TEMPO MVFR CIG WITH SPRINKLES AS THE UPPER TROUGH MOVES THROUGH...BUT NOTHING WORSE THAN THAT. LOW LEVEL MOISTURE LOOKS TO REMAIN HIGH AGAIN TONIGHT...SO ANOTHER BOUGHT OF 4-6SM VSBYS LOOKS LIKELY AS SKIES CLEAR OUT BEHIND THIS WAVE. WINDS TODAY LOOK TO BE FAIRLY LIGHT /LESS THAN 5 KTS/ AND OUT OF THE SW TODAY...TRANSITIONING TO WNW TONIGHT. OUTLOOK... THU...VFR FRI...MVFR CIGS POSSIBLE. NO PRECIP EXPECTED ATTM. SAT-SUN...VFR. MON-TUE...-SN POSSIBLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ BAP/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
315 AM CST WED FEB 15 2012 .DISCUSSION... RATHER COMPLITCATED UPPER AIR PATTERN IN PLACE WITH SATELLITE IMAGERY SHOWING MULTIPLE WEATHER DISTURBANCES AFFECTING THE AREA IN THE NEXT 24 HOURS. THE FIRST IS A VORT NOW WEAKENING AND SHEARING OUT OF CENTRAL MN AS IT MOVES ACROSS N WI. ASSOCIATED -SN WILL BE NORTH OF OUR AREA BY 12Z. A PAIR OF UPSTREAM VORTS LURK AHEAD IN THE DKTS WITH ANOTHER DIVING SE ACROSS SASK. THE MORE WELL DEFINED DKTS FEATURE IS IN W NODAK NEAR DIK WITH ANOTHER MOVING ACROSS W SODAK. BOTH HAVE LIGHT MIXED PCPN ASSOCIATED WITH THEM. THE 06Z NAM HAS PRETTY GOOD PLACEMENT OF BOTH OF THESE. SOME CONCERN FOR THE MORNING HOURS THAT THE SOUTHERN FEATURE MAY CARRY SOME LIGHT MIXED PCPN INTO OUR WESTERN COUNTIES...WHICH HRRR HAS BEEN ADVERTISING LAST FEW RUNS. PROGGED SOUNDINGS SHOW TEMP PROFILE WARM ENUF FOR LIQUID AT LEAST AS FAR N AS THE MVE AREA. IF PCPN HOLDS OFF UNTIL AROUND 15Z...SHUD BE MAINLY --RA AND --SN...BUT IF IT MOVES IN PRIOR TO THAT HAVE RISK OF --ZR. WITH LOWER LEVELS TAKING SOME TIME TO SATURATE...WON`T MENTION THE ZR THREAT. DURING THE AFTN THE BETTER FORCING THEN FOCUSED MORE TO OUR NORTH AS NODAK VORT LIFTS ACROSS N MN. CONFINED PCPN THEN TO JUST A S/C -SN IN SOME CENTRAL MN COUNTIES. WEDGE OF CLEAR SKIES ACROSS MUCH OF THE AREA ATTM WILL BE FILLING IN DURING THE MORNING AS UPSTREAM SYSTEMS APPROACH AREA. FOR TONIGHT...KEPT SMALL CHANCE OF --SN IN EASTERN AREAS...BUT FOCUS OF ANY SIG PCPN WILL BE WELL TO OUR SOUTH AS SHORTWAVE NOW IN NEW MEXICO LIFTS ACROSS THE CENTRAL U.S. INTO THE OHIO VALLEY. A LITTLE COOLER ON THURSDAY ACROSS EASTERN AREAS AS NW WINDS BRING IN A BIT OF COOLING BEHIND THE WEAK SURFACE TROF MOVING THRU TODAY. IN THE WEST...WEST WINDS AHEAD OF NEXT SYSTEM ALREADY BEGIN TO PULL WARMER AIR BACK IN. MILD THURSDAY NIGHT WITH SW WINDS AHEAD OF SURFACE LOW DROPPING ACROSS THE DAKTOAS INTO SW MN. NAM AN OUTLIER WITH SYSTEM DROPPING ACROSS THE AREA MUCH FASTER AND SFC WINDS NW ACROSS AREA BY 12Z FRIDAY. RETAINED CURRENT DRY FCST...BUT 00Z ECMWF IS QUIRTING OUT SOME LIGHT QPF MAINLY SW OF MN RIVER INTO SC MN ON FRIDAY. A BIT COOLER ON SATURDAY BEHIND THIS SYSTEM. LOW TEMPS SATURDAY MORNING WITH BE TRICKY WITH MODELS SHOWING A FAIRLY WIDE RANGE IN POSTION OF SURFACE HIGH PRESSURE RANGING FROM SE MN ON NAM TO THE EASTERN DAKOTAS ON THE GFS. JURY STILL OUT ON THE MONDAY/MONDAY NIGHT SYSTEM. GFS HAS PROBABLY BEEN THE MOST CONSISENT SHOWING POSSIBLE PCPN OF SIGNIFICANCE...BUT 00Z ECMWF IS BEGINING TO TREND BACK TOWARD THE GFS. TRIMMED BACK ON THE AREA OF MIXED PCPN WITH MODEL TRENDS NOW FAVORING SURFACE LOW TRACK MORE ACROSS IOWA. && .AVIATION.../06Z TAF ISSUANCE/ SFC LOW PRES CENTER NEAR KSTC WILL CONTINUE TO ROTATE ENE THROUGH THE AREA OVERNIGHT. SEVERAL BANDS OF -SHSN MOVING THROUGH MAINLY ERN MN AND WRN WI WILL PRODUCE OCNL IFR CONDS BUT THE TRICKY PART THROUGH THE REST OF THE OVERNIGHT WILL BE LOW CIGS TRANSITIONING TO FOG. CLEARING LINE IS APPROXIMATELY FROM KMOX-KHCD-KSYN-KRST AND SLOWLY SHIFTING EWD. LITTLE IN THE WAY OF FOG FORMING WITH THE CLEARING ALTHOUGH THE WIND SHIFT TO WSW WITH THE CLEARING IS BRINGING IN DRIER AIR IN THE LOWER LEVELS SO THIS MAY BE MITIGATING SOME FOG FORMATION. HAVE ISSUED A MUCH MORE OPTIMISTIC SET OF TAFS...AVOIDING IFR CONDITIONS AND HOLDING CONDITIONS ONLY AS LOW AS MVFR. AFTER DAYBREAK...LOWER CLOUDS RETURN FOR MUCH OF THE DAY ACRS THE AREA...THUS HAVE ADVERTISED MVFR CIGS FOR MUCH OF THE DAY. ANOTHER AREA OF LOW PRESSURE WILL BE DIVING DOWN FROM THE NORTH LATE IN THE DAY INTO THE EVENING...BUT CHCS FOR PRECIP ARE QUITE LOW /ONLY ABOUT 20 PERCENT...AND FOR MAINLY EASTERN TAF SITES/ SO HAVE REMOVED ITS MENTION FROM THIS TAF SET. CONDITIONS THEN GRADUALLY IMPROVE WEDNESDAY NIGHT INTO THURSDAY MORNING. MSP...INITIALIZED WITH VFR CONDITIONS BUT A SCATTERING OF OB SITES ARND KMSP ARE REPORTING MVFR. ONCE THE CLEARING LINE MOVES THROUGH AND WINDS SETTLE DOWN A BIT...AM EXPECTING VSBYS TO DROP INTO THE MVFR RANGE DURING THE PRE-DAWN HOURS. AFTER DAYBREAK... CONDITIONS IMPROVE TO VFR INTO LATE MRNG THEN LOW CLOUDS RETURN FOR MUCH OF THE AFTN AND EVENING. MODELS INDICATE THAT DECKS WILL REMAIN IN THE 2-3 KFT RANGE THROUGH LATE EVENING BEFORE RISING TO VFR LEVELS WEDNESDAY NIGHT INTO THURSDAY MORNING. OUTLOOK... /THU/...VFR UNDER PASSING HIGH PRESSURE. /FRI/...MVFR CIGS POSSIBLE WITH A WEAK LOW PRESSURE SYSTEM DROPPING THROUGH. NO PRECIP EXPECTED ATTM. /SAT-SUN/...VFR. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPC/BAP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1115 PM CST TUE FEB 14 2012 .UPDATE... UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW. && .PREVIOUS DISCUSSION/UPDATE... SENT QUICK UPDATE TO GRIDDED AND TEXT PRODUCTS BASED ON RADAR AND SHORT-TERM TRENDS. SFC LOW PRESSURE CENTERED REFLECTED NICELY ON KMPX RADAR WITH THE CENTER ROTATING THROUGH CENTRAL MN WEST OF THE TWIN CITIES. SEVERAL PASSING BANDS HAVE PRODUCED DUSTING ACCUMULATIONS AS THEY HAVE ROTATED THROUGH...SO HAVE INCRD POPS TO THE LOW-MID CHC RANGE FOR CENTRAL AND EASTERN PORTIONS OF THE WFO MPX COVERAGE AREA. NONE OF THE BANDS ARE LONG-LASTING NOR ARE THEY PRODUCING ANYTHING SIGNIFICANT...SO AM ONLY EXPECTING A TENTH TO A QUARTER INCH OF SNOW THROUGH THE OVERNIGHT HOURS WITH THE HIGHEST AMOUNTS OVER ERN MN INTO W-CENTRAL WI. LOCAL WRF...SREF AND RUC ARE HAVING A HARD TIME WITH THE INITIALIZATION WHILE THE 18Z AND 00Z RUNS OF THE HRRR BOTH CAPTURE THINGS QUITE WELL SO AM STICKING CLOSE TO ITS PROJECTIONS FOR MOST WX ELEMENTS THROUGH THE OVERNIGHT HOURS. && .AVIATION.../06Z TAF ISSUANCE/ SFC LOW PRES CENTER NEAR KSTC WILL CONTINUE TO ROTATE ENE THROUGH THE AREA OVERNIGHT. SEVERAL BANDS OF -SHSN MOVING THROUGH MAINLY ERN MN AND WRN WI WILL PRODUCE OCNL IFR CONDS BUT THE TRICKY PART THROUGH THE REST OF THE OVERNIGHT WILL BE LOW CIGS TRANSITIONING TO FOG. CLEARING LINE IS APPROXIMATELY FROM KMOX-KHCD-KSYN-KRST AND SLOWLY SHIFTING EWD. LITTLE IN THE WAY OF FOG FORMING WITH THE CLEARING ALTHOUGH THE WIND SHIFT TO WSW WITH THE CLEARING IS BRINGING IN DRIER AIR IN THE LOWER LEVELS SO THIS MAY BE MITIGATING SOME FOG FORMATION. HAVE ISSUED A MUCH MORE OPTIMISTIC SET OF TAFS...AVOIDING IFR CONDITIONS AND HOLDING CONDITIONS ONLY AS LOW AS MVFR. AFTER DAYBREAK...LOWER CLOUDS RETURN FOR MUCH OF THE DAY ACRS THE AREA...THUS HAVE ADVERTISED MVFR CIGS FOR MUCH OF THE DAY. ANOTHER AREA OF LOW PRESSURE WILL BE DIVING DOWN FROM THE NORTH LATE IN THE DAY INTO THE EVENING...BUT CHCS FOR PRECIP ARE QUITE LOW /ONLY ABOUT 20 PERCENT...AND FOR MAINLY EASTERN TAF SITES/ SO HAVE REMOVED ITS MENTION FROM THIS TAF SET. CONDITIONS THEN GRADUALLY IMPROVE WEDNESDAY NIGHT INTO THURSDAY MORNING. MSP...INITIALIZED WITH VFR CONDITIONS BUT A SCATTERING OF OB SITES ARND KMSP ARE REPORTING MVFR. ONCE THE CLEARING LINE MOVES THROUGH AND WINDS SETTLE DOWN A BIT...AM EXPECTING VSBYS TO DROP INTO THE MVFR RANGE DURING THE PRE-DAWN HOURS. AFTER DAYBREAK... CONDITIONS IMPROVE TO VFR INTO LATE MRNG THEN LOW CLOUDS RETURN FOR MUCH OF THE AFTN AND EVENING. MODELS INDICATE THAT DECKS WILL REMAIN IN THE 2-3 KFT RANGE THROUGH LATE EVENING BEFORE RISING TO VFR LEVELS WEDNESDAY NIGHT INTO THURSDAY MORNING. OUTLOOK... /THU/...VFR UNDER PASSING HIGH PRESSURE. /FRI/...MVFR CIGS POSSIBLE WITH A WEAK LOW PRESSURE SYSTEM DROPPING THROUGH. NO PRECIP EXPECTED ATTM. /SAT-SUN/...VFR. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
404 AM CST Wed Feb 15 2012 .DISCUSSION... Isentropic assent has begun to spread northeast ahead of the shortwave exiting the Four Corners region, as evident by the cloud cover and storm development stretching from the crook of the Texas panhandle through eastern Kansas and Missouri. Cyclogenesis ahead of the shortwave is currently focused across southwest Kansas, though the development of a warm front seems to be evident on surface observations from north of Kansas City east into the vicinity of St. Louis, thanks to the exiting surface high moisture return on its backside. For Today, as the associated surface cyclone shifts east through the day, the warm front is expected to rotate into northern Missouri, thus supporting above normal temperatures today for most locations except extreme northwest Missouri, where the front is not likely to reach. Fog issues that where expected to develop early this morning as a result of warm air advection across the cold ground, have not begun to surface yet. Cloud cover and modest boundary layer mixing in advance of the approaching system looks to be keeping the fog issue at bay for now. Have reoriented morning POPs to reflect current trends in radar and models, which focuses rain across the southern half of the forecast area this morning, south of the developing warm front, spreading to the rest of the forecast region this afternoon as the warm front pivots north. Limited instability may still result in isolated thunderstorms through the day with the rain. This evening, the potential for precipitation should fade through the night as the upper level shortwave traverses Kansas and Missouri, dragging a cold front with it. There looks to be some potential on the very back side of the exiting precipitation shield for temperatures to drop fast enough to make precipitation type overnight a little iffy. Though, currently have held to the observation that model sounding indicate the surface will be the last layer of the atmosphere to fall below freezing tonight, and that in most locations the precipitation is likely to shut off before the thermal profile cools enough for precipitation conversion. Therefore, have opted to include a limited area of sleet in the far northwest corner of Missouri, where afternoon temperatures wont get very warm, and the evening falling temperatures behind the cold front will arrive first. For Thursday and Friday, conditions will dry out, with above normal temperatures as the surface high behind the cold front wont be particularly cold. However, by Saturday, model inconsistencies are evident once again and the operational and ensemble models are showing some disagreement on how to eject a cutoff low in the Desert Southwest. At this time, the GFS has begun to trend to a more open wave solution which brings the low out much faster and farther north than in previous runs, phasing with a potent shortwave rotating through the Great Lakes. As a result the GFS is advertising rain across central Missouri early Saturday. Have chosen to ignore the GFS solution this morning as it is the outlier, opting to keep the focus for our next round of precipitation on the Sunday Night through Tuesday. In these outer periods models continue to point at bits and peaces of a western CONUS trough ejecting through the Central Plains, and by Sunday night into Monday these ejecting energy packets should be able to tap into returning Gulf moisture. Cutter && .AVIATION... For the 06Z TAFs...Watching closely the area of IFR/LIFR ceilings and visibilities that are expanding northward out of Oklahoma. All latest guidance suggests this moisture may be slower to reach the KC/STJ terminals than previously forecast, which makes sense with thick mid/high clouds making it difficult to cool off the boundary layer and achieve thick low level saturation. So for now, bumped back the arrival of IFR/LIFR conditions to after 12Z. RUC and LAMP guidance suggest conditions may not deteriorate until mid morning. Still expect restrictions to both cigs and vsbys once this moisture arrives, with cigs possibly well into LIFR. Areas of rain will overspread the area through the afternoon, and while there could be some embedded thunder, the threat for this is too low to include any prolonged mention of thunder in the TAFs at this point. While there could be occasional lifts into MVFR during the afternoon, IFR is expected to be the general rule and this should continue after 00Z behind a cold front. Showery precipitation behind this front may mix with snow at times but any wintry precipitation should be light and brief. Hawblitzel && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1134 PM CST Tue Feb 14 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Compact, yet potent PV anomaly passing through central Arizona (several CG strikes noted in advance of cold core aloft) will rapidly eject into the plains early Wednesday providing the strong likelihood for widespread rain showers and embedded thunderstorms. A modest 30-40kt LLJ axis will develop in response to downstream height falls and lee cyclogenesis pulling an unseasonably high theta-e airmass north towards a materializing warm front through the immediate forecast area. Broad, moist isentropic ascent through a deep 290K-300K layer will support slantwise ascent of low static stability air such that pockets of elevated mucapes of 100-200 J/kg will become common through the southern half of the cwa. Have increased pops above numerical statistical guidance and hastened precipitation onset given waa regime and historical model biases under such scenarios. Aside from a near definite precipitation potential, am concerned about fog potential overnight in advance and coincident with the rain shield. Although snow melt has been rather effective under full insolation this afternoon, residual snow along with cold ground temperatures juxtaposed with low/mid 40 dewpoints pulled north appears prime for a widespread advection fog event. However, uncertainty is greater with respect to how dense this fog may be, or whether it will lift more into a low stratus deck with enough mixing to the top of the shallow boundary layer. Future shifts will need to closely assess the onset time and potential for any advisory statements. A second round of showers (or a partial continuation of the morning activity) and isolated storms also appears very likely through the late afternoon and evening in association with increasing dynamical lift in advance of the vorticity center and layered elevated frontogenesis. With pwats on the order of 0.75 inches and prolonged forcing, would expect areas of half inch rainfall totals on partially frozen and moist ground unlocking any left over snow pack. River headwater guidance remains above one inch for the most part, so not expecting any significant flooding issues, however some minor problems may arise on the typical smaller basins. With little to no cold air advection and the overall system opening up and weakening, see minimal chance for true deformation banding and dynamical cooling through a deep column. Thus, will not advertise any wintry mix before moisture is scoured east with the shortwave forcing. Pacific high pressure builds east Thursday, with H9 temperatures remaining above 0C yielding highs at and above normal for mid-February. Have stayed on the warmer end of guidance and towards and sref mean for temperatures here. 21 Medium Range (Friday-Tuesday)... A fairly active weather pattern looks to be in place across the country through the extended period, with above normal temperatures and a chance for precipitation early next week expected for the forecast area. For Friday, the region will be wedged between a large upper level trough over the Great Lakes region and a closed off upper low over extreme northern Mexico. Between these two systems an area of high pressure will be in place over the region, pushing into the Ohio River Valley through the day. This tracking of the surface high will lead to a southwesterly/westerly flow into the forecast area, which will lead to afternoon temperatures 5 to 10F above seasonal normals. A weak and dry cold front will move through the region Friday night, shifting winds to the northwest. For Saturday, a second surface high will move into the Northern and Central Plains. With a light northerly flow still in place, temperatures will be slightly cooler than on Friday, but still a few degrees warmer than normal. Models are in agreement for keeping the southern closed-off low south of the region as it tracks eastward along the Gulf coast Saturday into Sunday. The surface high will progress east of the region on Sunday, resulting in winds shifting to the southeast and yet another unseasonably mild winter day. Main focus though will be on an upper level trough that will move into the Pacific Northwest on Saturday and move into the Northern and Central Plains by Monday morning. Discrepancies exist between the GFS/ECMWF with regards to just how far south this trough will dig into the Central Plains, ultimately affecting temperatures and possibly precipitation type. 12Z GFS shows a stronger, deeper trough resulting in colder temperatures being ushered into the region which could result in the chance for a rain/snow mix across the Missouri/Iowa border. 12Z ECMWF shows a weaker trough focused primarily across the Northern Plains, resulting in warmer conditions and precipitation remaining in the form of rain. Have kept the mention of a rain/snow mix in extreme northern Missouri and northeast Kansas, but confidence is not high in having snow mixed in. Precipitation from this system should exit the region Monday evening. By Tuesday there is a wide variation amongst the models regarding the chance for additional precipitation, so have nothing more than slight chance pops at this time. Temperatures for the start of the work week will be a continuation of the unseasonably mild trend from the weekend. ACH && .AVIATION... For the 06Z TAFs...Watching closely the area of IFR/LIFR ceilings and visibilities that are expanding northward out of Oklahoma. All latest guidance suggests this moisture may be slower to reach the KC/STJ terminals than previously forecast, which makes sense with thick mid/high clouds making it difficult to cool off the boundary layer and achieve thick low level saturation. So for now, bumped back the arrival of IFR/LIFR conditions to after 12Z. RUC and LAMP guidance suggest conditions may not deteriorate until mid morning. Still expect restrictions to both cigs and vsbys once this moisture arrives, with cigs possibly well into LIFR. Areas of rain will overspread the area through the afternoon, and while there could be some embedded thunder, the threat for this is too low to include any prolonged mention of thunder in the TAFs at this point. While there could be occasional lifts into MVFR during the afternoon, IFR is expected to be the general rule and this should continue after 00Z behind a cold front. Showery precipitation behind this front may mix with snow at times but any wintry precipitation should be light and brief. Hawblitzel && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
936 AM MST WED FEB 15 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY... SENT AN UPDATE THIS MORNING TO ADD SOME FLURRIES AS REPORTED THIS MORNING FROM A PHONE CALL TO SCOBEY. AS THE HRRR MODEL PERFORMED SO WELL YESTERDAY AND CURRENT RADAR TRENDS ARE HEADING THAT WAY...I FELT IT WAS BEST TO BRING IN A SLIGHT CHANCE FOR SNOW FOR OUR NORTHEAST ZONES THIS AFTERNOON FOLLOWING THE HRRR MODEL SOLUTION. EXPECT THE SNOW FIELD GRADIENT TO HAVE AN EFFECT ON THE TEMPERATURES TODAY. BARE GROUND NEAR WINNETT MAY REACH 40 DEGREES WHILE MALTA AND GLASGOW WILL STRUGGLE TO REACH 30 DEGREES. AFTERNOON WINDS FROM THE NORTHWEST WILL BE A LITTLE BREEZY. BMICKELSON PREVIOUS SHORT TERM DISCUSSION...UPPER TROF DIPPING INTO THE NORTHERN PLAINS THIS MORNING. SHORTWAVE WHICH BROUGHT THE SNOWFALL ALONG THE MILK/MISSOURI RIVER YESTERDAY MOVING THROUGH NORTH DAKOTA WITH SNOW ENDING ACROSS THE REGION. SKIES CLEARING BEHIND THIS WAVE HAS RESULTING IN TEMPERATURES DROPPING SIGNIFICANTLY THIS MORNING. SOME MID LEVEL CLOUD MOVING INTO THE NORTHERN ZONES WITH ANOTHER SHORTWAVE PUSHING THROUGH SASKATCHEWAN THIS MORNING. OBSERVATIONS AND RADAR NOT INDICATING ANY PRECIPITATION WITH THIS SECOND SHORTWAVE SO JUST ANTICIPATING CLOUD COVER ACROSS THE NORTHEAST ZONES. OTHER CONCERN FOR TODAY IS TEMPERATURES DUE TO THE FRESH SNOWFALL. STARTING OUT VERY COLD AND SUNSHINE WILL ALSO BE SOMEWHAT LIMITED OVER THE REGION THAT RECEIVED THE SNOW SO EXPECT TEMPERATURES TO BE SLOWER TO RECOVER. A THIRD SHORTWAVE DROPS ACROSS CENTRAL CANADA ON THURSDAY. THIS WAVE PHASES WITH ANOTHER SHORTWAVE PUSHING OUT OF THE PACIFIC NORTHWEST THAT DROPS ACROSS WESTERN MONTANA THURSDAY NIGHT. THIS PACIFIC WAVE COULD PRODUCE SOME PRECIPITATION OVER CENTRAL MONTANA WHILE THE CENTRAL CANADIAN WAVE PUSHES MOST OF ITS MOISTURE INTO NORTH DAKOTA. THIS SHOULD KEEP MOST OF NORTHEAST MONTANA DRY THROUGH FRIDAY. EACH OF THESE WAVES BRING COLD AIR INTO THE REGION SO NOT EXPECTING QUICK SNOWMELT...AND THUS SNOW COVER WILL LIKELY BE IMPACTING TEMPERATURES OVER THE NORTH. EBERT .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY... LONG TERM FORECAST PERIOD BEGINS WITH AN UPPER LEVEL RIDGE OVER ALL OF CENTRAL MONTANA. FRIDAY NIGHT INTO SATURDAY AFTERNOON AN APPROACHING UPPER LEVEL LOW MOVES ONSHORE OVER THE PACIFIC NORTHWEST PUSHING THE UPPER RIDGE EASTWARD INTO THE NORTHERN PLAINS. THIS UPPER LOW BECOMES MORE OF AN OPEN WAVE WHICH WILL SPLIT AND SEND THE MORE ACTIVE PART OF THE SYSTEM OVER THE CENTRAL ROCKIES. THE NORTHERN PART OF THIS OPEN WAVE WILL CROSS THE NORTHERN ROCKIES AND IT WILL TRIGGER SOME LIGHT SNOW SHOWERS ACROSS NEMONT SATURDAY NIGHT THROUGH SUNDAY NIGHT. LOOKS LIKE ANOTHER INCH OR TWO OF SNOW WILL BE POSSIBLE BUT KEPT POPS IN THE LOWER CHANCE RANGE FOR NOW. MODELS TAKE THE SOUTHERN PART OF THIS UPPER WAVE INTO THE CENTRAL PLAINS BY MONDAY AND IT BECOMES VERTICALLY STACKED. IT LOOKS AS THOUGH THIS SYSTEM WILL BE TOO FAR TO THE SOUTH TO EFFECT WEATHER ACROSS EASTERN MONTANA. GENERALLY THE UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE REST OF THE EXTENDED AND NORTHEAST MONTANA SEEMS PINNED BETWEEN A RIDGING INFLUENCE FROM THE SOUTHWEST AND CONTINUED TROUGHING OVER THE GREAT LAKES. THIS MEANS EASTERN MONTANA WILL BE IN THE NORTHWEST FLOW WITH DISTURBANCES MOVING THROUGH THIS FLOW FROM MONDAY THROUGH THURSDAY NIGHT. MODELS ARE ALL DIFFERENT ON TIMING OF THESE WAVES BUT TUESDAY NIGHT INTO WEDNESDAY LOOKS LIKE A PERIOD THAT THE MODELS ARE IN SOME AGREEMENT FOR MORE LIGHT SNOWFALL. SO ADDED SOME SLIGHT CHANCE POPS TO THIS TIME FRAME. RSMITH && .AVIATION... VFR. SCATTERED TO BROKEN CEILINGS ARE EXPECTED ACROSS THE AREA TODAY. A BRIEF FLURRY MAY OCCUR NORTHEAST OF THE TAF SITES...POSSIBLY SNEAKING INTO THE SIDNEY AREA. NORTHWEST WINDS WILL INCREASE A BIT THIS AFTERNOON TO 10 TO 15 KTS. JAMBA && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
513 PM CST THU FEB 16 2012 .AVIATION...00Z TAF. VFR CONDITIONS WILL BE IN PLACE TO START THE 00Z TAF PERIOD. THE MAIN CONCERN WILL BE THE POSSIBILITY OF FOG DUE TO CLEAR SKIES...LIGHT WINDS AND LOW LEVEL MOISTURE FROM THE MELTING SNOW. RUC PROXIMITY SOUNDINGS SHOW THE POSSIBILITY OF AT LEAST PATCHY FOG AT KGRI...AND WILL CONTINUE TO CARRY 4SM VISIBILITIES IN A TEMPO GROUP LATE TONIGHT INTO EARLY FRIDAY MORNING. ONCE THE FOG EXITS...VFR CONDITIONS ARE AGAIN EXPECTED TO PREVAIL. WINDS WILL START FROM THE SOUTHWEST...BUT WILL GRADUALLY TURN TO A NORTHERLY DIRECTION DUE TO A PASSING COLD FRONT. && .PREV DISCUSSION... /ISSUED 347 PM CST THU FEB 16 2012/ SHORT TERM...SHORT TERM...TONIGHT AND FRIDAY...THE UPPER LEVEL PATTERN REVEALS A SPLIT FLOW FOR ESSENTIALLY THE WESTERN HALF OF THE COUNTRY AS A CLOSED LOW MOVE EAST ACROSS NORTHERN MEXICO AND A NORTHERN STREAM WAVE MOVES INTO THE NORTHERN PLAINS. THERE HAS BEEN SOME DECENT MELTING OF SNOW TODAY...AND WITH RELATIVELY LIGHT WIND...WE COULD HAVE SOME FOG OVER THE SNOWPACK OF SOUTH CENTRAL NEBRASKA TONIGHT INTO EARLY FRIDAY MORNING. WITH RETURN FLOW TONIGHT...TEMPERATURES MAY DROP OFF MORE SLOWLY FOR SOME AREAS OR ACTUALLY RISE FOR A TIME AS WELL. A COLD FRONT WILL MOVE THROUGH FROM THE NORTH ON FRIDAY...BUT CONDITIONS ARE SO DRY THAT I AM NOT EXPECTING MUCH MORE THAN SOME CLOUDS. ALSO...WITH SOME MIXING AND THE FACT THAT THE AIR BEHIND THE COLD FRONT IS NOT VERY COLD...TEMPERATURES SHOULD RISE INTO THE LOWER TO MID 40S FOR FRIDAY. STUCK CLOSER TO THE ECMWF SOLUTION FOR FRIDAY. LONG TERM...FRIDAY NIGHT THROUGH THURSDAY. PRIMARY FORECAST CONCERN LIES WITH PRECIPITATION CHANCES DURING THE LATE WEEKEND/EARLY NEXT WEEK TIME PERIOD. A LITTLE BIT OF UNCERTAINTY HAS POPPED UP LOOKING AT THE START OF THE LONG TERM PERIOD...WITH WHETHER OR NOT SOUTHERN PORTIONS OF THE CWA MIGHT SEE SOME PRECIPITATION. FRIDAY EVENING/OVERNIGHT SHOWS THE CWA SITTING BETWEEN SYSTEMS...A NORTHERN STREAM TROUGH DIVING SOUTH THROUGH THE DAKOTAS AND A SOUTHERN STREAM SYSTEM MAKING ITS WAY THROUGH THE DESERT SW. FOR THE PAST COUPLE OF DAYS MODELS HAVE BEEN FAIRLY CONSISTENT SHOWING INCREASED LIFT OUT AHEAD OF THAT SOUTHERN SYSTEM CREEPING NORTH THROUGH THE SOUTHERN PLAINS...BUT HAD REMAINED SOUTH OF THE CWA. MOST MODELS CONTINUE THAT TREND...BUT THE 12Z GFS DID PUSH THAT PRECIPITATION FAR ENOUGH NORTH TO IMPACT THE SOUTHERN FRINGE OF THE CWA. WONT PUT ANY POPS IN AT THIS POINT...BUT IF THIS IS A TREND THE OTHER MODELS BEGIN TO SUPPORT...SOME MAY NEED TO BE ADDED. THROUGH THE DAY ON SATURDAY THESE SYSTEMS BECOME MORE PHASED TOGETHER...AND BY MIDDAY THE AXIS IS EXPECTED TO BE ON ITS WAY PAST THE CWA. SATURDAY NIGHT...THIS SYSTEM CONTINUES TO PUSH EAST INTO THE MIDWEST...WHILE ANOTHER UPPER LEVEL SYSTEM IS WORKING INLAND FROM THE WEST COAST. THIS RESULTS IN SHORTWAVE RIDGING DEVELOPING OVER THE ROCKIES...WITH THE AXIS MAKING ITS WAY EAST ONTO THE PLAINS ON SUNDAY...AND LOOKS TO BE CENTERED RIGHT THROUGH THE PLAINS DURING THE AFTERNOON...CONTINUING THE DRY FORECAST. THE SURFACE PATTERN FRIDAY NIGHT AND INTO SATURDAY IS IMPACTED BY HIGH PRESSURE...WHICH SETTLES IN OVER THE CWA BY 12Z SATURDAY...AND THEN GRADUALLY STARTS TO SHIFT OFF TO THE EAST. ALONG WITH THE LIGHTER WINDS ACCOMPANYING THE SURFACE HIGH...A COOLER AIR MASS IS EXPECTED...WHICH WILL BRING A DROP IN TEMPERATURES. THE HIGH/COOLER AIR LOOK TO LINGER AROUND WELL THROUGH SATURDAY...WITH HIGH TEMPERATURES FORECAST IN THE MID 30S TO LOWER 40S...JUST A FEW DEGREES BELOW AVERAGE FOR THIS TIME OF YEAR. SOUTHERLY WINDS RETURN SATURDAY NIGHT/SUNDAY...AS THE CWA GETS SANDWICHED BETWEEN THE SFC HIGH SLIDING EAST AND LOW PRESSURE DEVELOPING OVER THE ROCKIES AHEAD OF THE NEXT SYSTEM APPROACHING FROM THE WEST. SEE A SLIGHT BUMP UP IN TEMPS ALOFT...AND WITH MORE SOUTHERLY FLOW AND MORE SUNSHINE...EXPECTING HIGHS TO REBOUND BACK INTO THE MID/UPPER 40S. SUNDAY NIGHT THROUGH MONDAY NIGHT REMAINS THE MOST ACTIVE TIME DURING THE LONG TERM PERIOD...BUT WITH SOME DIFFERENCE REMAINING BETWEEN MODELS...CERTAINLY PLENTY TO WORK OUT OVER THE COMING DAYS. SUNDAY EVENING...MODELS SHOW A LOW PRESSURE SYSTEM SET UP OVER PORTIONS OF CANADA...WITH THE ACCOMPANYING TROUGH AXIS EXTENDING SOUTH THROUGH THE WRN/CNTL ROCKIES. AS WE GET CONTINUE THROUGH MONDAY/MONDAY NIGHT...LATEST MODEL RUNS SHOWING A CLOSED 700MB LOW/OPEN 500MB TROUGH SWINGING THROUGH THE CENTRAL PLAINS. WHERE ONE DIFFERENCE ARISES IS WITH TIMING...GFS IS A TOUCH QUICKER THROUGH THE CWA THAN THE EC /ENDING PRECIP TIME ROUGHLY 6HRS SLOWER/. WILL CONTINUE TO SIDE WITH THE SLOWER SOLUTION. SOME SLIGHT DIFFERENCE EXIST WITH SFC/LOW LEVEL TEMPS AND RESULTING PRECIP TYPE...BUT WITH IT STILL 4 DAYS OUT ITS A LITTLE EARLY TO GET OVERLY EXACT. THERE IS GOOD AGREEMENT THAT THE TEMPERATURES ARE NOT ARCTIC IN NATURE...AND AT THIS POINT MODELS ARE SHOWING 850MB TEMPS ONLY DROPPING TO A FEW DEGREES BELOW ZERO AT BEST...AND AM EXPECTING THIS TO BE A RA TO RA/WET SN MIX. DID UP POPS ACROSS THE CWA...THE EC IS MORE AGGRESSIVE WITH THE OVERALL QPF AMOUNT AND COVERAGE VS THE GFS...AND HAVE THE BETTER POPS ACROSS THE NORTHERN HALF OF THE CWA. DID TREND BACK HIGHS ON MONDAY A TOUCH...BUT AM CONCERNED THAT WITH THE CLOUDS/PRECIP EXPECTED THAT IT MAY NOT BE ENOUGH /ESP IN THE NORTH/. LOOKING AT THE REST OF THE PERIOD...TUES THROUGH THURS...NOT THE MOST TRANQUIL UPPER LEVEL PATTERN ACROSS THE CONUS...AND KEPT THE FORECAST DRY WITH THE CWA AT THIS POINT NOT LOOKING TO BE DIRECTLY IMPACTED BY ANY DISTURBANCE. MODELS DO SHOW ACTIVITY IN CLOSE PROXIMITY...SO ITS BY NO MEANS A HIGH CONFIDENCE DRY FORECAST. STAYED CLOSE TO ALLBLEND TEMPS...WITH GENERALLY 40S ACROSS THE CWA...POTENTIALLY SOME LOWER 50S ACROSS THE SOUTH. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...HEINLEIN LONG TERM...ADO AVIATION...KING
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1142 AM CST WED FEB 15 2012 .AVIATION... A FEW AREAS OF PATCHY FOG REMAIN OVER THE AREA BUT OVERALL VISIBILITIES WILL BE MVFR TO VFR. KLNK WILL HAVE BEST CHANCE AT ANY RAIN SO DID INCLUDE A TEMPO GROUP IN FOR THIS AFTERNOON. WILL MONITOR RADAR TRENDS FOR KOMA BUT RAIN LOOKS TO REMAIN WEST OF THE AIRPORT FOR NOW. VFR CONDITIONS EXPECTED OVERNIGHT WITH MAINLY MID CLOUDS OVERHEAD. LIGHT NORTHWEST TO WEST SFC WINDS MAY KEEP FOG POTENTIAL DOWN OVERNIGHT. KERN && .PREV DISCUSSION... /ISSUED 647 AM CST WED FEB 15 2012/ UPDATE... UPDATED FOR SHORT-LIVED WINTER WEATHER ADVISORY FOR FREEZING RAIN NERN NEBRASKA AND DENSE FOG ADVISORY SWRN ZONES DISCUSSION... BAND OF LIGHT FREEZING RAIN SPREADING ACROSS NERN ZONES ASSOCIATED WITH UPPER TROUGH SWINGING THRU DAKOTAS/NRN NEBRASKA WAS CREATING ICE COVERED ROADS/BLACK ICE ACCORDING TO NEDOR. ISSUED A SHORT- LIVED WINTER WEATHER ADVISORY TO ACCOUNT FOR THIS. IN ADDITION...LOW LEVEL MOISTURE STREAMING NORTH OVER EXISTING SNOW COVER WILL PROBABLY ONLY INCREASE COVERAGE OF DENSEST FOG SWRN ZONES SO WENT AHEAD AND ISSUED A DENSE FOG ADVISORY THAT AREA. AS FRONT APPROACHES...BOUNDARY LAYER WINDS SHOULD TURN MORE N/NE HALTING THE MOISTURE ADVECTION. ALSO MENTIONED A LITTLE FREEZING RAIN POSSIBLE FAR S AS LIGHT RETURNS MOVE INTO FAR SE NEBR. CHERMOK PREV DISCUSSION... /ISSUED 518 AM CST WED FEB 15 2012/ AVIATION... 12Z TAFS FOR KOFK...KOMA AND KLNK. COMPLEX AVIATION SCENARIO SHAPING UP FOR THE FIRST PART OF TODAY AT LEAST. IFR CONDITIONS IN STRATUS/FOG WERE SPREADING INTO FAR SOUTHEAST NEBRASKA SW OF KLNK AS OF 15/11Z. IN ADDITION...PATCHY FOG WAS OBSERVED NORTHEAST OF THE LOW CLOUDS BUT SOUTHEAST OF A MID CLOUD DECK THAT CONTAINED SCATTERED LIGHT RAIN OR LIGHT FREEZING RAIN SHOWERS ADVANCING ACROSS NORTHEAST NEBRASKA. THIS LIGHT PRECIP SHOULD BE CONFINED TO KOFK TAF EARLY THIS MORNING AND THE LOW CLOUD ADVANCE SHOULD MAKE IT TO KLNK. WITH LOW LEVEL WINDS RELAXING AND POSSIBLY SHIFTING TO NERLY...NEWD DEVELOPMENT/ADVECTION OF LOW CLOUDS INTO KOMA QUESTIONABLE BUT SOME WERE INCLUDED IN 12Z TAF FORECAST. A FRONT PUSHING THROUGH CENTRAL NEBRASKA WILL CROSS TAF SITES LATER TODAY AND A PERIOD OF LOW CLOUDS IS POSSIBLE BEHIND THE FRONT...ALTHOUGH THEY COULD TEND TO MIX OUT WITH HEATING. OVERALL A CHANGEABLE FORECAST WITH LOW CONFIDENCE IN TIMING OF LOWER CIGS/VSBYS. CHERMOK PREV DISCUSSION... /ISSUED 255 AM CST WED FEB 15 2012/ DISCUSSION... VARIABLE SKY COVER ACROSS THE FORECAST AREA AT 08Z WITH PATCHY DENSE FOG REPORTED OVER EAST CENTRAL NEBRASKA AT KAHQ AND AROUND KOLU. CLOUDS ENCROACHING FROM THE WEST AND SOUTH AND SHOULD OVERSPREAD THE AREA BY 12Z. BEST CHANCE FOR PRECIP STILL LOOKS TO BE OVER SOUTHERN PARTS OF THE AREA...GENERALLY SOUTH OF I80 AFTER 12Z. TIMING HOWEVER MAY BE A PROBLEM AS LATEST RUC FORECAST SOUNDINGS SHOW LIMITED MID LEVEL MOISTURE THROUGH MID MORNING ALONG THE KANSAS BORDER THERE. HAVE LIMITED CHANCE POPS IN THAT AREA THROUGH THE MORNING IN LINE WITH BOTH THE GFS AND NAM. BASED ON THIS START TIME SHOULD SEE MAINLY RAIN THIS MORNING. AREA OF RAIN THEN SPREADS NORTH FOR THE AFTERNOON WITH CHANCE POPS TO JUST SOUTH OF THE OMAHA AREA INTO LINCOLN AND SOUTHWEST CORNER OF IOWA. A CHANCE OF MIXED RAIN OR FREEZING RAIN IN THE EVENING FOR FAR SOUTHEAST NEBRASKA AND SOUTHWEST CORNER OF IOWA BEFORE PRECIP SLIDES EAST AND ENDS. NO HEADLINES ANTICIPATED AT THIS TIME. LOOKS DRY AFTER THAT THROUGH FRIDAY NIGHT ALTHOUGH MODELS DIFFER IN TIMING OF CLIPPER AND ASSOCIATED COLD FRONT THAT COMES ACROSS THE AREA ON FRIDAY WITH THE GFS STRONGER WITH ITS FEATURES THAN THE NAM OR EURO. UPPER RIDGING MOVES INTO THE REGION EARLY IN THE EXTENDED WITH SOMEWHAT WARMER TEMPERATURES BUT FAIRLY STRONG WAVE FOLLOWS FAST ON ITS HEELS SUNDAY NIGHT INTO MONDAY. GFS AGAIN STRONGER THAN THE EURO WITH THIS SYSTEM SO LOW CONFIDENCE WITH TIMING AND TRACK. TIMING ISSUES THEN CONTINUE BETWEEN THE TWO MODELS THROUGH THE REMAINDER OF THE FORECAST PERIOD. FOBERT AVIATION... 06Z TAF FOR KOMA...KLNK AND KOFK. FOG WILL BE THE PRIMARY CONCERN FOR THE TAF SITES...AND PRIMARILY AT KLNK/KOMA. MID CLOUDS HAVE CLEARED THE AREA WITH MOSTLY CLEAR SKIES. THIS SHOULD ALLOW FOG TO CONTINUE TO DEVELOP...ALREADY 5 MILES AT KLNK. DROPPED VISIBILITY TO 5 MILES WITH IFR CEILINGS DEVELOPING... BUT BELIEVE CONDITIONS SHOULD IMPROVE BY 15Z WITH JUST SOME HAZE AFTER THAT. REGARDING PRECIPITATION...BELIEVE PRECIP MAY DEVELOP ALONG THE KS/NE BORDER REGION...BUT HAVE DOUBTS THAT IT WOULD MAKE IT AS FAR NORTH AS KLNK/KOMA. ALSO FORECAST A WIND SHIFT...FROM GENERALLY LIGHT AND VARIABLE...TO NORTH NORTHWEST...INITIALLY AT KOFK AT 16Z...THEN AT AT KLNK/KOMA BY ABOUT 20Z. DEWALD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
647 AM CST WED FEB 15 2012 .UPDATE... UPDATED FOR SHORT-LIVED WINTER WEATHER ADVISORY FOR FREEZING RAIN NERN NEBRASKA AND DENSE FOG ADVISORY SWRN ZONES && .DISCUSSION... BAND OF LIGHT FREEZING RAIN SPREADING ACROSS NERN ZONES ASSOCIATED WITH UPPER TROUGH SWINGING THRU DAKOTAS/NRN NEBRASKA WAS CREATING ICE COVERED ROADS/BLACK ICE ACCORDING TO NEDOR. ISSUED A SHORT- LIVED WINTER WEATHER ADVISORY TO ACCOUNT FOR THIS. IN ADDITION...LOW LEVEL MOISTURE STREAMING NORTH OVER EXISTING SNOW COVER WILL PROBABLY ONLY INCREASE COVERAGE OF DENSEST FOG SWRN ZONES SO WENT AHEAD AND ISSUED A DENSE FOG ADVISORY THAT AREA. AS FRONT APPROACHES...BOUNDARY LAYER WINDS SHOULD TURN MORE N/NE HALTING THE MOISTURE ADVECTION. ALSO MENTIONED A LITTLE FREEZING RAIN POSSIBLE FAR S AS LIGHT RETURNS MOVE INTO FAR SE NEBR. CHERMOK && .PREV DISCUSSION... /ISSUED 518 AM CST WED FEB 15 2012/ AVIATION... 12Z TAFS FOR KOFK...KOMA AND KLNK. COMPLEX AVIATION SCENARIO SHAPING UP FOR THE FIRST PART OF TODAY AT LEAST. IFR CONDITIONS IN STRATUS/FOG WERE SPREADING INTO FAR SOUTHEAST NEBRASKA SW OF KLNK AS OF 15/11Z. IN ADDITION...PATCHY FOG WAS OBSERVED NORTHEAST OF THE LOW CLOUDS BUT SOUTHEAST OF A MID CLOUD DECK THAT CONTAINED SCATTERED LIGHT RAIN OR LIGHT FREEZING RAIN SHOWERS ADVANCING ACROSS NORTHEAST NEBRASKA. THIS LIGHT PRECIP SHOULD BE CONFINED TO KOFK TAF EARLY THIS MORNING AND THE LOW CLOUD ADVANCE SHOULD MAKE IT TO KLNK. WITH LOW LEVEL WINDS RELAXING AND POSSIBLY SHIFTING TO NERLY...NEWD DEVELOPMENT/ADVECTION OF LOW CLOUDS INTO KOMA QUESTIONABLE BUT SOME WERE INCLUDED IN 12Z TAF FORECAST. A FRONT PUSHING THROUGH CENTRAL NEBRASKA WILL CROSS TAF SITES LATER TODAY AND A PERIOD OF LOW CLOUDS IS POSSIBLE BEHIND THE FRONT...ALTHOUGH THEY COULD TEND TO MIX OUT WITH HEATING. OVERALL A CHANGEABLE FORECAST WITH LOW CONFIDENCE IN TIMING OF LOWER CIGS/VSBYS. CHERMOK PREV DISCUSSION... /ISSUED 255 AM CST WED FEB 15 2012/ DISCUSSION... VARIABLE SKY COVER ACROSS THE FORECAST AREA AT 08Z WITH PATCHY DENSE FOG REPORTED OVER EAST CENTRAL NEBRASKA AT KAHQ AND AROUND KOLU. CLOUDS ENCROACHING FROM THE WEST AND SOUTH AND SHOULD OVERSPREAD THE AREA BY 12Z. BEST CHANCE FOR PRECIP STILL LOOKS TO BE OVER SOUTHERN PARTS OF THE AREA...GENERALLY SOUTH OF I80 AFTER 12Z. TIMING HOWEVER MAY BE A PROBLEM AS LATEST RUC FORECAST SOUNDINGS SHOW LIMITED MID LEVEL MOISTURE THROUGH MID MORNING ALONG THE KANSAS BORDER THERE. HAVE LIMITED CHANCE POPS IN THAT AREA THROUGH THE MORNING IN LINE WITH BOTH THE GFS AND NAM. BASED ON THIS START TIME SHOULD SEE MAINLY RAIN THIS MORNING. AREA OF RAIN THEN SPREADS NORTH FOR THE AFTERNOON WITH CHANCE POPS TO JUST SOUTH OF THE OMAHA AREA INTO LINCOLN AND SOUTHWEST CORNER OF IOWA. A CHANCE OF MIXED RAIN OR FREEZING RAIN IN THE EVENING FOR FAR SOUTHEAST NEBRASKA AND SOUTHWEST CORNER OF IOWA BEFORE PRECIP SLIDES EAST AND ENDS. NO HEADLINES ANTICIPATED AT THIS TIME. LOOKS DRY AFTER THAT THROUGH FRIDAY NIGHT ALTHOUGH MODELS DIFFER IN TIMING OF CLIPPER AND ASSOCIATED COLD FRONT THAT COMES ACROSS THE AREA ON FRIDAY WITH THE GFS STRONGER WITH ITS FEATURES THAN THE NAM OR EURO. UPPER RIDGING MOVES INTO THE REGION EARLY IN THE EXTENDED WITH SOMEWHAT WARMER TEMPERATURES BUT FAIRLY STRONG WAVE FOLLOWS FAST ON ITS HEELS SUNDAY NIGHT INTO MONDAY. GFS AGAIN STRONGER THAN THE EURO WITH THIS SYSTEM SO LOW CONFIDENCE WITH TIMING AND TRACK. TIMING ISSUES THEN CONTINUE BETWEEN THE TWO MODELS THROUGH THE REMAINDER OF THE FORECAST PERIOD. FOBERT AVIATION... 06Z TAF FOR KOMA...KLNK AND KOFK. FOG WILL BE THE PRIMARY CONCERN FOR THE TAF SITES...AND PRIMARILY AT KLNK/KOMA. MID CLOUDS HAVE CLEARED THE AREA WITH MOSTLY CLEAR SKIES. THIS SHOULD ALLOW FOG TO CONTINUE TO DEVELOP...ALREADY 5 MILES AT KLNK. DROPPED VISIBILITY TO 5 MILES WITH IFR CEILINGS DEVELOPING... BUT BELIEVE CONDITIONS SHOULD IMPROVE BY 15Z WITH JUST SOME HAZE AFTER THAT. REGARDING PRECIPITATION...BELIEVE PRECIP MAY DEVELOP ALONG THE KS/NE BORDER REGION...BUT HAVE DOUBTS THAT IT WOULD MAKE IT AS FAR NORTH AS KLNK/KOMA. ALSO FORECAST A WIND SHIFT...FROM GENERALLY LIGHT AND VARIABLE...TO NORTH NORTHWEST...INITIALLY AT KOFK AT 16Z...THEN AT AT KLNK/KOMA BY ABOUT 20Z. DEWALD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ043-044- 050-051-065-066-078-088>090-092. WINTER WEATHER ADVISORY UNTIL 10 AM CST THIS MORNING FOR NEZ012- 016>018-030>032-042. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
518 AM CST WED FEB 15 2012 .AVIATION... 12Z TAFS FOR KOFK...KOMA AND KLNK. COMPLEX AVIATION SCENARIO SHAPING UP FOR THE FIRST PART OF TODAY AT LEAST. IFR CONDITIONS IN STRATUS/FOG WERE SPREADING INTO FAR SOUTHEAST NEBRASKA SW OF KLNK AS OF 15/11Z. IN ADDITION...PATCHY FOG WAS OBSERVED NORTHEAST OF THE LOW CLOUDS BUT SOUTHEAST OF A MID CLOUD DECK THAT CONTAINED SCATTERED LIGHT RAIN OR LIGHT FREEZING RAIN SHOWERS ADVANCING ACROSS NORTHEAST NEBRASKA. THIS LIGHT PRECIP SHOULD BE CONFINED TO KOFK TAF EARLY THIS MORNING AND THE LOW CLOUD ADVANCE SHOULD MAKE IT TO KLNK. WITH LOW LEVEL WINDS RELAXING AND POSSIBLY SHIFTING TO NERLY...NEWD DEVELOPMENT/ADVECTION OF LOW CLOUDS INTO KOMA QUESTIONABLE BUT SOME WERE INCLUDED IN 12Z TAF FORECAST. A FRONT PUSHING THROUGH CENTRAL NEBRASKA WILL CROSS TAF SITES LATER TODAY AND A PERIOD OF LOW CLOUDS IS POSSIBLE BEHIND THE FRONT...ALTHOUGH THEY COULD TEND TO MIX OUT WITH HEATING. OVERALL A CHANGEABLE FORECAST WITH LOW CONFIDENCE IN TIMING OF LOWER CIGS/VSBYS. CHERMOK && .PREV DISCUSSION... /ISSUED 255 AM CST WED FEB 15 2012/ DISCUSSION... VARIABLE SKY COVER ACROSS THE FORECAST AREA AT 08Z WITH PATCHY DENSE FOG REPORTED OVER EAST CENTRAL NEBRASKA AT KAHQ AND AROUND KOLU. CLOUDS ENCROACHING FROM THE WEST AND SOUTH AND SHOULD OVERSPREAD THE AREA BY 12Z. BEST CHANCE FOR PRECIP STILL LOOKS TO BE OVER SOUTHERN PARTS OF THE AREA...GENERALLY SOUTH OF I80 AFTER 12Z. TIMING HOWEVER MAY BE A PROBLEM AS LATEST RUC FORECAST SOUNDINGS SHOW LIMITED MID LEVEL MOISTURE THROUGH MID MORNING ALONG THE KANSAS BORDER THERE. HAVE LIMITED CHANCE POPS IN THAT AREA THROUGH THE MORNING IN LINE WITH BOTH THE GFS AND NAM. BASED ON THIS START TIME SHOULD SEE MAINLY RAIN THIS MORNING. AREA OF RAIN THEN SPREADS NORTH FOR THE AFTERNOON WITH CHANCE POPS TO JUST SOUTH OF THE OMAHA AREA INTO LINCOLN AND SOUTHWEST CORNER OF IOWA. A CHANCE OF MIXED RAIN OR FREEZING RAIN IN THE EVENING FOR FAR SOUTHEAST NEBRASKA AND SOUTHWEST CORNER OF IOWA BEFORE PRECIP SLIDES EAST AND ENDS. NO HEADLINES ANTICIPATED AT THIS TIME. LOOKS DRY AFTER THAT THROUGH FRIDAY NIGHT ALTHOUGH MODELS DIFFER IN TIMING OF CLIPPER AND ASSOCIATED COLD FRONT THAT COMES ACROSS THE AREA ON FRIDAY WITH THE GFS STRONGER WITH ITS FEATURES THAN THE NAM OR EURO. UPPER RIDGING MOVES INTO THE REGION EARLY IN THE EXTENDED WITH SOMEWHAT WARMER TEMPERATURES BUT FAIRLY STRONG WAVE FOLLOWS FAST ON ITS HEELS SUNDAY NIGHT INTO MONDAY. GFS AGAIN STRONGER THAN THE EURO WITH THIS SYSTEM SO LOW CONFIDENCE WITH TIMING AND TRACK. TIMING ISSUES THEN CONTINUE BETWEEN THE TWO MODELS THROUGH THE REMAINDER OF THE FORECAST PERIOD. FOBERT AVIATION... 06Z TAF FOR KOMA...KLNK AND KOFK. FOG WILL BE THE PRIMARY CONCERN FOR THE TAF SITES...AND PRIMARILY AT KLNK/KOMA. MID CLOUDS HAVE CLEARED THE AREA WITH MOSTLY CLEAR SKIES. THIS SHOULD ALLOW FOG TO CONTINUE TO DEVELOP...ALREADY 5 MILES AT KLNK. DROPPED VISIBILITY TO 5 MILES WITH IFR CEILINGS DEVELOPING... BUT BELIEVE CONDITIONS SHOULD IMPROVE BY 15Z WITH JUST SOME HAZE AFTER THAT. REGARDING PRECIPITATION...BELIEVE PRECIP MAY DEVELOP ALONG THE KS/NE BORDER REGION...BUT HAVE DOUBTS THAT IT WOULD MAKE IT AS FAR NORTH AS KLNK/KOMA. ALSO FORECAST A WIND SHIFT...FROM GENERALLY LIGHT AND VARIABLE...TO NORTH NORTHWEST...INITIALLY AT KOFK AT 16Z...THEN AT AT KLNK/KOMA BY ABOUT 20Z. DEWALD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
355 AM CST WED FEB 15 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT. MAIN FORECAST CONCERNS WILL BE PRECIPITATION CHANCES AND TYPE TODAY...THEN TEMPERATURES. SATELLITE AND OBSERVATIONS SHOW STRATUS MOVING INTO THE SOUTHERN PART OF THE FORECAST AREA EARLY THIS MORNING. RADAR HAS A FEW RETURNS IN THE WESTERN PART OF THE FORECAST AREA...BUT SURFACE OBSERVATIONS INDICATE THIS IS COMING OUR OF MID LEVEL CLOUDS SO BELIEVE THAT AT MOST IT WOULD BE VERY LIGHT PRECIPITATION. VICINITY SOUNDINGS INDICATE THAT THE PRECIPITATION WOULD LIKELY BE FALLING AS RAIN BUT WITH SURFACE TEMPERATURES JUST BELOW FREEZING IT COULD BE FREEZING RAIN. SO FAR EXPECT THAT IT IS ONLY SPRINKLES OR LIGHT PRECIPITATION. THE UPPER LEVEL LOW CONTINUES TO MOVE THROUGH SOUTHERN KANSAS DURING THE DAY TODAY. PRECIPITATION IS EXPECTED TO DEVELOP AND SPREAD INTO NORTH CENTRAL KANSAS AND FAR SOUTH CENTRAL NEBRASKA DURING THE MORNING. VICINITY SOUNDINGS HAVE A VERY WARM LAYER ABOVE THE SURFACE AND EXPECT THE PRECIPITATION TO FALL AS LIQUID. WITH TEMPERATURES NEAR OR JUST BELOW FREEZING THIS WOULD MEAN EITHER RAIN OR FREEZING RAIN. THE PRECIPITATION CONTINUES TO PUSH A LITTLE TO THE NORTH DURING THE AFTERNOON. TEMPERATURES DURING THE DAY SHOULD WARM TO JUST ABOVE FREEZING AND PRECIPITATION SHOULD CHANGE TO RAIN ACROSS THE AREA. AS THE LOW MOVES TO THE EAST THERE IS SOME CONCERN WITH THE COLDER AIR MOVING INTO THE AREA. SOUNDINGS REVEAL THAT BY THE TIME THE COLDER AIR MOVES IN THE PRECIPITATION SHOULD BE COMING TO AN END. BY EVENING THE COLDER AIR PUSHES INTO THE AREA...BUT THE PRECIPITATION SHOULD BE ENDING ACROSS THE FAR SOUTHEAST DURING THE EARLY EVENING. ONCE THIS SYSTEM MOVES TO THE EAST THERE IS ZONAL TO NORTHWEST FLOW ALOFT. QUIET WEATHER IS EXPECTED WITH A SURFACE HIGH THAT SETTLES INTO THE REGION. TEMPERATURES RETURN TO NEAR NORMAL OR A LITTLE ABOVE. THE AREAS WITH SNOW WILL BE A LITTLE COOLER. .LONG TERM...SATURDAY THROUGH TUESDAY. THE WEEKEND LOOKS GREAT...BUT ANOTHER STORM SYSTEM MAY BRING A RETURN TO WINTRY WEATHER BY MONDAY. SATURDAY AND SUNDAY WILL BE DRY ACROSS THE CENTRAL PLAINS WITH THE REGION IN A LULL BETWEEN STORM SYSTEMS. THE WIND WILL BE SOUTHERLY AND THE TEMPERATURES FAIRLY MILD ALLOWING FOR CONTINUED SNOW MELT. THERE MAY NOT REALLY BE MUCH IN THE WAY OF SNOW COVER LEFT BY THE END OF THIS WEEKEND. THE SNOW COVER WILL CONTINUE TO HAVE SOME IMPACT ON HIGH TEMPERATURES UNTIL ITS GONE...BUT THE OVERALL INFLUENCE ON TEMPERATURES WILL DECREASE EACH DAY AS THERE WILL BE LESS AND LESS SNOW COVER AROUND. MONDAY...FORECAST MODELS CONTINUE TO HINT AT THE NEXT STORM SYSTEM ROLLING OUT OF THE ROCKIES AND INTO THE CENTRAL PLAINS ON MONDAY. THERE IS STILL FAIRLY SIGNIFICANT VARIATIONS IN THE TRACK OF THIS SYSTEM FROM MODEL RUN TO MODEL RUN AND AMONG THE DIFFERING ENSEMBLE MEMBERS. PRECIPITATION TYPE WILL BE AN ADDITIONAL CHALLENGE WITH BOTH RAIN AND SNOW POSSIBLE. THE STORM SYSTEM SHOULD FOR THE MOST PART BE OUT OF THE AREA OR NEARLY OUT OF THE AREA BY TUESDAY. && .PREV DISCUSSION... /ISSUED 1217 AM CST WED FEB 15 2012/ AVIATION...06Z KGRI TAF. THERE CONTINUE TO BE SEVERAL CHALLENGES FOR THIS FORECAST PERIOD INCLUDING THE POSSIBILITY OF FOG AND LOW CEILINGS. A STORM SYSTEM WILL MOVE ACROSS PARTS OF KANSAS TODAY. THE MOST RECENT FORECAST MODEL GUIDANCE IS IN GOOD AGREEMENT THAT ANY ACCUMULATING PRECIPITATION SHOULD REMAIN SOUTH OF KGRI. REDUCED VISIBILITIES DUE TO FOG COULD TURN OUT TO BE A MORE IMMEDIATE CONCERN AT THE TERMINAL LOCATION WITH VISIBILITY FORECASTS FROM THE NAM AND HRRR CONTINUING TO SUGGEST SURFACE VISIBILITIES COULD FALL QUICKLY EARLY THIS MORNING. CEILINGS ARE ANOTHER CONCERN WITH STRATUS ACROSS PARTS OF OKLAHOMA EXPECTED TO STREAM ITS WAY NORTH THIS MORNING...BUT QUESTION IF IT WILL MAKE IT AS FAR NORTH AS KGRI. ANOTHER POSSIBILITY FOR LOWER CEILINGS WILL EXIST DUE TO THE PASSAGE OF A COLD FRONT BY LATE MORNING. CLOUDS WILL SCATTER OUT THIS EVENING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ005>007- 017>019. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
255 AM CST WED FEB 15 2012 .DISCUSSION... VARIABLE SKY COVER ACROSS THE FORECAST AREA AT 08Z WITH PATCHY DENSE FOG REPORTED OVER EAST CENTRAL NEBRASKA AT KAHQ AND AROUND KOLU. CLOUDS ENCROACHING FROM THE WEST AND SOUTH AND SHOULD OVERSPREAD THE AREA BY 12Z. BEST CHANCE FOR PRECIP STILL LOOKS TO BE OVER SOUTHERN PARTS OF THE AREA...GENERALLY SOUTH OF I80 AFTER 12Z. TIMING HOWEVER MAY BE A PROBLEM AS LATEST RUC FORECAST SOUNDINGS SHOW LIMITED MID LEVEL MOISTURE THROUGH MID MORNING ALONG THE KANSAS BORDER THERE. HAVE LIMITED CHANCE POPS IN THAT AREA THROUGH THE MORNING IN LINE WITH BOTH THE GFS AND NAM. BASED ON THIS START TIME SHOULD SEE MAINLY RAIN THIS MORNING. AREA OF RAIN THEN SPREADS NORTH FOR THE AFTERNOON WITH CHANCE POPS TO JUST SOUTH OF THE OMAHA AREA INTO LINCOLN AND SOUTHWEST CORNER OF IOWA. A CHANCE OF MIXED RAIN OR FREEZING RAIN IN THE EVENING FOR FAR SOUTHEAST NEBRASKA AND SOUTHWEST CORNER OF IOWA BEFORE PRECIP SLIDES EAST AND ENDS. NO HEADLINES ANTICIPATED AT THIS TIME. LOOKS DRY AFTER THAT THROUGH FRIDAY NIGHT ALTHOUGH MODELS DIFFER IN TIMING OF CLIPPER AND ASSOCIATED COLD FRONT THAT COMES ACROSS THE AREA ON FRIDAY WITH THE GFS STRONGER WITH ITS FEATURES THAN THE NAM OR EURO. UPPER RIDGING MOVES INTO THE REGION EARLY IN THE EXTENDED WITH SOMEWHAT WARMER TEMPERATURES BUT FAIRLY STRONG WAVE FOLLOWS FAST ON ITS HEELS SUNDAY NIGHT INTO MONDAY. GFS AGAIN STRONGER THAN THE EURO WITH THIS SYSTEM SO LOW CONFIDENCE WITH TIMING AND TRACK. TIMING ISSUES THEN CONTINUE BETWEEN THE TWO MODELS THROUGH THE REMAINDER OF THE FORECAST PERIOD. && .AVIATION... 06Z TAF FOR KOMA...KLNK AND KOFK. FOG WILL BE THE PRIMARY CONCERN FOR THE TAF SITES...AND PRIMARILY AT KLNK/KOMA. MID CLOUDS HAVE CLEARED THE AREA WITH MOSTLY CLEAR SKIES. THIS SHOULD ALLOW FOG TO CONTINUE TO DEVELOP...ALREADY 5 MILES AT KLNK. DROPPED VISIBILITY TO 5 MILES WITH IFR CEILINGS DEVELOPING... BUT BELIEVE CONDITIONS SHOULD IMPROVE BY 15Z WITH JUST SOME HAZE AFTER THAT. REGARDING PRECIPITATION...BELIEVE PRECIP MAY DEVELOP ALONG THE KS/NE BORDER REGION...BUT HAVE DOUBTS THAT IT WOULD MAKE IT AS FAR NORTH AS KLNK/KOMA. ALSO FORECAST A WIND SHIFT...FROM GENERALLY LIGHT AND VARIABLE...TO NORTH NORTHWEST...INITIALLY AT KOFK AT 16Z...THEN AT AT KLNK/KOMA BY ABOUT 20Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ FOBERT/DEWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1217 AM CST WED FEB 15 2012 .AVIATION...06Z KGRI TAF. THERE CONTINUE TO BE SEVERAL CHALLENGES FOR THIS FORECAST PERIOD INCLUDING THE POSSIBILITY OF FOG AND LOW CEILINGS. A STORM SYSTEM WILL MOVE ACROSS PARTS OF KANSAS TODAY. THE MOST RECENT FORECAST MODEL GUIDANCE IS IN GOOD AGREEMENT THAT ANY ACCUMULATING PRECIPITATION SHOULD REMAIN SOUTH OF KGRI. REDUCED VISIBILITIES DUE TO FOG COULD TURN OUT TO BE A MORE IMMEDIATE CONCERN AT THE TERMINAL LOCATION WITH VISIBILITY FORECASTS FROM THE NAM AND HRRR CONTINUING TO SUGGEST SURFACE VISIBILITIES COULD FALL QUICKLY EARLY THIS MORNING. CEILINGS ARE ANOTHER CONCERN WITH STRATUS ACROSS PARTS OF OKLAHOMA EXPECTED TO STREAM ITS WAY NORTH THIS MORNING...BUT QUESTION IF IT WILL MAKE IT AS FAR NORTH AS KGRI. ANOTHER POSSIBILITY FOR LOWER CEILINGS WILL EXIST DUE TO THE PASSAGE OF A COLD FRONT BY LATE MORNING. CLOUDS WILL SCATTER OUT THIS EVENING. && .PREV DISCUSSION... /ISSUED 358 PM CST TUE FEB 14 2012/ SHORT TERM...TONIGHT AND WEDNESDAY... GENERAL CONSENSUS OF MODELS REGARDING THE TRACK OF THE LOW COMING OUT OF THE ROCKIES IS THAT THIS WILL IMPACT ESSENTIALLY THE SOUTHEAST ONE THIRD TO ONE HALF OF THE CWA TO VARYING DEGREES...DEPENDING ON WHICH MODEL SOLUTION ONE BELIEVES. SOUNDING LOOK DRY FOR TONIGHT ACROSS SOUTH CENTRAL NEBRASKA...BUT BOUNDARY LAYER MOISTURE FOR OUR NORTH CENTRAL COUNTIES INCREASES LATE TONIGHT WITH A SIGNIFICANT DRY LAYER POINTING TOWARD A LIGHT ICING EVENT AS A SIGNIFICANT WARM LAYER EXISTS ABOVE THE SURFACE. SREF ENSEMBLES ARE FAIRLY SLUGGISH BRINGING CHANCES OF PRECIPITATION NORTH...WHICH WORKS TO OUR FAVOR TO AVOID FREEZING RAIN AND SLEET FOR MOST OF SOUTH CENTRAL NEBRASKA. SNOW AMOUNTS APPEAR TO BE MINIMAL AND BELOW A HALF INCH IN THIS CASE. BY AFTERNOON...ANY PRECIPITATION SHOULD BE RAIN OR SNOW AS THE WARM LAYER COOLS OFF AND EVERY MODEL SOLUTION POINTS TO THIS. ISSUING A WINTER WEATHER ADVISORY 3 AM TO NOON FOR POTENTIAL FREEZING DRIZZLE/RAIN IN THE SOUTH WHICH WILL PRODUCE A POTENTIAL LIGHT GLAZE. ANOTHER THING TO WATCH OUT FOR IS SOME FOG IN THE SOUTHEAST HALF OF THE CWA. SIGNALS ARE PRETTY STRONG FOR THIS FROM THE SREF. TEMPERATURES SHOULD CLIMB JUST ABOVE FREEZING FOR MOST OF THE CWA IN THE AFTERNOON ACCORDING TO MOST MODEL SOLUTIONS. LONG TERM...STARTING 00Z THURSDAY. GUIDANCE SUGGEST THE MID AND UPPER LEVEL FLOW WILL REMAIN RATHER ACTIVE WITH SEVERAL SMALL SCALE PERTURBATIONS PUSHING OVERHEAD DURING THE TIME PERIOD. FORCING WITH MANY OF THESE DISTURBANCES WILL REMAIN VERY WEAK HOWEVER...AND AN OVERALL LACK OF LOWER TROPOSPHERIC MOISTURE SHOULD PREVENT PRECIPITATION PRODUCTION FROM OCCURRING ACROSS OUR AREA THROUGH SUNDAY. THE OPERATIONAL GFS AND EC BOTH SUGGEST A MORE SIGNIFICANT MID LEVEL SYSTEM WILL ADVANCE EAST FROM THE WESTERN CONUS DURING THE EARLY PART OF NEXT WEEK...BRINGING WITH IT INCREASED MID LEVEL THERMAL ADVECTION AND RESULTANT LIFT. LOWER TROPOSPHERIC MOISTURE SHOULD ALSO BE ON THE INCREASE BY SUNDAY AS LOW LEVEL SOUTHERLY FLOW ESTABLISHES ITSELF ACROSS THE REGION TO FINISH OUT THE WEEKEND. GIVEN ALL THIS...WENT AHEAD AND KEPT POPS ACROSS THE CWA SUNDAY NIGHT AND MONDAY. THE EC REMAINS SOMEWHAT SLOWER PUSHING THE SYSTEM OUT OF OUR AREA WHEN COMPARED TO THE GFS AND AS A RESULT...ALSO KEPT SLIGHT CHANCE POPS LINGERING ACROSS OUR EAST SUNDAY NIGHT AND MONDAY. A PERSISTENT DOWN SLOPING LOW LEVEL WIND FIELD THROUGH SATURDAY WILL LIKELY PROMOTE WARMER CONDITIONS ACROSS THE AREA...ALTHOUGH SNOW PACK WILL HAMPER FULL TEMPERATURE RECOVERY ACROSS PORTIONS OF SOUTH CENTRAL NEBRASKA. AS A RESULT...KEPT DAYTIME TEMPERATURE RISES UNDER 20 DEGREES ACROSS MANY OF OUR NEBRASKA COUNTIES...WITH LARGER TEMPERATURE RISES ACROSS SOUTHERN PORTIONS OF OUR CWA WHERE SNOW PACK HAS ALREADY DIMINISHED. FULL DAY TIME TEMPERATURE RECOVERY COULD BE POSSIBLE ACROSS THE ENTIRE CWA BY EARLY NEXT WEEK ASSUMING SUFFICIENT SNOW MELT...BUT INCREASED CLOUD COVER AND POSSIBLE PRECIPITATION SUGGEST DAY TIME TEMPERATURE RISES WILL ALSO BE HAMPERED SOMEWHAT EARLY NEXT WEEK. ALL THAT BEING SAID...FORECAST TEMPERATURES IN THE LONG TERM WILL REMAIN AT NEAR TO SLIGHTLY ABOVE-NORMAL LEVELS...WITH OVERNIGHT LOWS GENERALLY IN THE 20S AND LOW 30S...AND DAYTIME HIGHS GENERALLY IN THE 30S AND 40S. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ005>007- 017>019. && $$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
601 AM EST WED FEB 15 2012 .SYNOPSIS... A WEAK WEATHER DISTURBANCE MOVING OUT OF THE OHIO VALLEY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. LIGHT SNOW AND SCATTERED FLURRIES WILL BE POSSIBLE AS THIS HAPPENS. BY WEDNESDAY...CONDITIONS WILL BEGIN TO IMPROVE AS WEAK HIGH PRESSURE MOVES INTO THE AREA FROM THE WEST. BY THURSDAY...ANOTHER DISTURBANCE WILL BARE DOWN ON THE REGION WHICH WILL LEAD TO THE NEXT ROUND OF PRECIPITATION ACROSS NORTHEAST PENNSYLVANIA AND CENTRAL NEW YORK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1 AM UPDATE... THE CURRENT FCST IS IN GOOD SHAPE...SO ONLY MINOR TWEAKS WERE MADE TO IT. RADAR MOSAIC CONTS TO SHOW PATCHY -RA/-SN OVER MUCH OF THE FA ATTM. AS AN UPR-LVL WAVE PROGRESSES THROUGH THE RGN EARLY THIS MRNG...THIS PCPN SHOULD PERSIST TIL 09-12Z...BEFORE DIMINISHING TO SPOTTY FLRYS/SPRINKLES. WE ADDED SOME VERY LGT SNOW ACCUMS PRIOR TO DAYBRK...OVER THE HIGHER TERRAIN OF NE PA AND THE CATSKILLS. WE`VE RECEIVED A COUPLE OF REPORTS OF A COATING OF SNOW THESE AREAS OVER THE PAST FEW HRS. MASSAGED NEAR-TERM TEMP GRIDS A BIT...TO BETTER REFLECT THE LATEST SFC OBS...AND ALSO BLEND IN THE MOST RECENT LAV TEMPS. 1000 PM UPDATE... A SHORT WAVE OVER NW PA AND WESTERN NY WILL CONTINUE TO MOVE NORTHEAST OVER THE CWA THROUGH EARLY WEDNESDAY MORNING. AN AREA OF LIGHT SNOW OVER NORTHERN PA WILL SLIDE NORTHEAST ACROSS THE CATSKILLS THROUGH 07Z. WITH SURFACE TEMPS NEAR OR ABOVE FREEZING...ONLY A DUSTING AT MOST IS EXPECTED IN THESE AREAS...WITH THE BEST CHANCE FOR THIS OCCURRING OVER THE HIGHEST TERRAIN. ASIDE FROM THIS AREA OF SNOW...THE REST OF THE NIGHT FOR MOST OF OUR AREA LOOKS VERY QUIET. A LOOK AT 0Z SOUNDINGS FROM BUFFALO AND PITTSBURGH ALONG WITH RUC FORECAST SOUNDINGS HAVE EASED THE CONCERN FOR FREEZING DRIZZLE OVERNIGHT SOMEWHAT. WHILE WE DO HAVE DRIER AIR WORKING INTO THE MID LEVELS...WE ARE STILL FAIRLY MOIST UP THROUGH -14C/-15C...SO WE SHOULD HAVE SOME ICE CRYSTALS TO WORK WITH. I NOTICED THAT MOST OF THE OBS TO THE WEST THAT REPORTED PLAIN DRIZZLE WERE IN CLOSE PROXIMITY TO THE LAKES...AND PROBABLY BEING INFLUENCED BY THEM. WHILE SOME PATCHY DRIZZLE HERE AND THEIR CAN`T ENTIRELY BE RULED OUT...THINKING THAT WHAT LITTLE PRECIP WE SEE FOR THE REST OF THE OVERNIGHT WILL BE JUST SOME SCT. FLURRIES. IT SEEMS OUR BEST SHOT AT A CHANGEOVER TO DRIZZLE WOULD BE MORE TOWARD MID-MORNING WEDNESDAY AS WE BEGIN TO DRY OUT DOWN TOWARD THE -10C LAYER. HOWEVER BY THE TIME THIS HAPPENS...BOUNDARY LAYER TEMPS WILL WARM ENOUGH THAT IT SHOULD NOT BE AN ISSUE. THE PREVIOUS AFD IS BELOW... 630 PM UPDATE... FORECAST LOOKS TO BE IN VERY GOOD SHAPE WITH CHANCE POPS ACROSS THE ENTIRE CWA THROUGH THE NEXT FEW HOURS. DESPITE RETURNS OF NEAR 20 DBZ ON RADAR...OBS ACROSS OUR AREA ARE SHOWING VERY...VERY LIGHT SNOW WITH VSBYS IN THE 4 TO 6SM RANGE. IN FACT ACROSS THE LOWER ELEVATIONS JUST SOME LIGHT RAIN OR DRIZZLE HAS BEEN REPORTED AT SYRACUSE AND AVOCA IS STILL 41! PRECIP WILL REMAIN LIGHT OVER THE NEXT FEW HOURS BUT AS THE BOUNDARY LAYER MOISTENS A BIT AND TEMPS COOL TO NEAR FREEZING WE MAY SEE A QUICK COATING OF SNOW OVER THE FAR NORTH (ONEIDA COUNTY). WE ARE ALREADY SEEING DRYING TO OUR WEST AND OUR NEXT CONCERN WILL BE THE CHANCE FOR SOME FREEZING DRIZZLE TONIGHT. THE PREVIOUS AFD ALREADY ADDRESSES THIS CONCERN AND WILL MONITOR AND UPDATE AS NEEDED LATER TONIGHT. SHORTWAVE ENERGY CURRENTLY LOCATED ACROSS THE EASTERN OHIO RVR VLY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. CURRENT REGIONAL RADAR IMAGERY DEPICTING MOST CONCENTRATED ACTIVITY ACROSS SOUTHERN PA...WITH LIGHTER ACTIVITY NOTED FURTHER TO THE NORTH. WITH TIME THIS EVENING...SHORTWAVE WILL PASS SOUTH OF THE REGION KEEPING THE BEST FORCING FOR ASCENT SOUTH OF THE CWA. THAT SAID...MAIN CONCERN WITH GOING FORECAST WILL BE INCREASING PROSPECTS FOR -FZDZ OVERNIGHT AS AFOREMENTIONED WAVE INTERACTS WITH AN APPROACHING ELEVATED FRONTAL BOUNDARY. BUFKIT SOUNDINGS INDICATE SUBSTANTIAL DRYING ALOFT AS WEAK UPPER RIDGING APPROACHES FROM THE WEST. AS THIS OCCURS...ICE CRYSTAL GROWTH POTENTIAL WILL DECREASE WITH LOSS OF SATURATION...THUS INTRODUCING THE POTENTIAL FOR -FZDZ ACROSS THE FORECAST AREA AS MOISTURE REMAINS CONFINED IN THE LOWEST 10KFT. WITH ONLY LIGHT QPF EXPECTED ACROSS THE FORECAST AREA OVERNIGHT...ANY -FZDZ THAT DEVELOPS WILL LIKELY BE PATCHY IN NATURE AND HAVE DECIDED TO JUST ADVERTISE POTENTIAL IN THE HWO PRODUCT FOR NOW. WITH ABUNDANT CLOUD COVER ALOFT...OVERNIGHT LOWS WILL REMAIN IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... BY WED...SHORTWAVE ENERGY AND ELEVATED FRONT WILL BE DEPARTING TO OUR EAST AS WEAK UPPER RIDGING BUILDS ACROSS THE NORTHEAST IN ADVANCE OF A CENTRAL PLAINS TROUGH. DIFFICULT TO PIN DOWN HOW QUICKLY PRECIP WILL EXIT TO THE EAST WED MORNING...BUT MODEL INDICATIONS SUGGEST IMPROVING CONDITIONS THROUGH THE LATE MORNING/EARLY AFTERNOON. HAVE MAINTAINED SLGT CHC MENTION ACROSS THE EASTERN CWA DURING THE AFTERNOON HRS...WITH MAINLY DRY CONDITIONS EXPECTED WED NIGHT AREA WIDE AS SURFACE HIGH PRESSURE MOVES OVER THE AREA. HIGH TEMPS WED SHOULD WARM INTO THE UPPER 30S TO NEAR 40 ALONG AND WEST OF I-81...WITH COOLER VALUES EXPECTED TO THE EAST. AFOREMENTIONED PLAINS DISTURBANCE WILL THEN TAKE AIM AT THE REGION BY EARLY THU MORNING. PER CURRENT MODEL TRENDS...DRY NEAR SURFACE LAYER CONDITIONS WILL REQUIRE COLUMN SATURATION BEFORE PRECIP MAKES ITS WAY TO THE GROUND...AND HAVE ELECTED TO DELAY THE PRECIP ARRIVAL TIME BY A FEW HRS THU MORNING AS A RESULT. WHEN PRECIP DOES ARRIVE AFTER 12Z...MAIN CONCERN WILL BE PRECIP TYPE. HIGH PRESSURE MOVING OFF TO OUR EAST COMBINED WITH AN APPROACHING WARM FRONT SUGGEST WE MAY RECEIVE A BRIEF WINTRY MIX THU MORNING BEFORE BULK OF ACTIVITY TRANSITIONS INTO RA AS REGION GETS ENTRENCHED IN THE WARM SECTOR AHEAD OF MAIN COLD FRONT. CURRENT LOW TRACK TAKES LOW FROM NEAR DETROIT NORTHEAST TO NORTH BAY, ON WHICH CERTAINLY IS REMINISCENT OF ANY SIGNIFICANT MIXED PRECIP EVENTS. THAT SAID...MAIN AREA OF CONCERN WILL BE ACROSS THE WESTERN MOHAWK VALLEY WERE AGEOSTROPIC WIND CIRCULATIONS MAY KEEP COLD AIR ENTRENCHED FOR A LONGER PERIOD OF TIME. ALL TOLD...HAVE DECIDED TO ENTER A WINTRY MIX MENTION IN THE MORNING...WITH WITH A GRADUAL CHANGEOVER TO RA AS THE DAY PROGRESSES. WILL CERTAINLY HAVE TO WATCH TRENDS IN THE COMING DAYS TO PIN DOWN THE DETAILS AS THE EVENT NEARS. BY THU NIGHT...MUCH OF THE AREA WILL BE POST FRONTAL WITH COLD AIR ADVECTION SLOWLY WORKING INTO THE AREA. LAKE EFFECT POTENTIAL WILL BE ON THE INCREASE FRI AS WESTERLY WINDS DOWN THE LENGTH OF THE LAKE COMBINE WITH H85 TEMPS -11C. CURRENT BUFKIT PROFILES SUGGEST BEST POTENTIAL FOR ANYTHING SIGNIFICANT WILL BE NORTH OF CWA IN WELL ALIGNED 270-280 FLOW HOWEVER MEAGER INVERSION HEIGHTS HOWEVER MAY BE A LIMITING FACTOR. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE EXTENDED PERIOD BEGINS WITH SHARP DISAGREEMENT BETWEEN THE GFS AND EURO SOLUTIONS. EACH SHOW A NORTHEASTERN TROF. HOWEVER THE GFS SOLUTION CALLS FOR A VIGOROUS, SHARP TROF WITH A STRONG STACKED LOW OVER LAKE ERIE AND AN EVEN STRONGER STORM SOUTHEAST OF LONG ISLAND. THE EURO CALLS FOR A MUCH GENTLER TROF, WITH LITTLE IN THE WAY OF WEATHER REFLECTED. MODELS PHASE INTO STRONG AGREEMENT THAT A LARGE HIGH PRESSURE SYSTEM WILL BUILD ALONG THE COAST FOR MONDAY AND TUESDAY, WITH NOTICEABLE RIDGING ALOFT. THE RESULT WOULD BE MUCH ABOVE AVERAGE TEMPERATURES, AND CLEAR WEATHER. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/... A WEAK TROF OF LOW PRESSURE IS MOVING THOUGH THE MID ATLANTIC REGION THIS MORNING. LIGHT FOG AND VERY LIGHT PRECIPITATION WILL CONTINUE NORTH OF THE TROF, INTO NY AND PA. THIS WILL BRING MAINLY MVFR CONDITIONS TO THE REGION THROUGH THIS AFTERNOON. A PERIOD OF IFR VISBYS IS EXPECTED AT AVP BETWEEN 11Z AND 14Z, FLUCTUATING BETWEEN 1 1/2SM AND 4SM. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT LATER TODAY, ALLOWING THE ATMOSPHERE TO DRY, AND CONDITIONS TO IMPROVE. VISIBILITIES WILL BE QUICKEST TO REACH VFR TERRITORY BY LATE MORNING. VFR CEILINGS ARE EXPECTED TOWARD SUNSET. .OUTLOOK... WED NGT...VFR. THUR...IFR/MVFR IN -SHRA AND PSBLY SOME MIXED PCPN AT ONSET. FRI/SAT...MAINLY VFR. SUN...VFR...PSBL MVFR/IFR PA WITH SNOW. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MLJ NEAR TERM...MLJ SHORT TERM...MLJ LONG TERM...DJP AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
301 AM EST WED FEB 15 2012 .SYNOPSIS... A WEAK WEATHER DISTURBANCE MOVING OUT OF THE OHIO VALLEY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. LIGHT SNOW AND SCATTERED FLURRIES WILL BE POSSIBLE AS THIS HAPPENS. BY WEDNESDAY...CONDITIONS WILL BEGIN TO IMPROVE AS WEAK HIGH PRESSURE MOVES INTO THE AREA FROM THE WEST. BY THURSDAY...ANOTHER DISTURBANCE WILL BARE DOWN ON THE REGION WHICH WILL LEAD TO THE NEXT ROUND OF PRECIPITATION ACROSS NORTHEAST PENNSYLVANIA AND CENTRAL NEW YORK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1 AM UPDATE... THE CURRENT FCST IS IN GOOD SHAPE...SO ONLY MINOR TWEAKS WERE MADE TO IT. RADAR MOSAIC CONTS TO SHOW PATCHY -RA/-SN OVER MUCH OF THE FA ATTM. AS AN UPR-LVL WAVE PROGRESSES THROUGH THE RGN EARLY THIS MRNG...THIS PCPN SHOULD PERSIST TIL 09-12Z...BEFORE DIMINISHING TO SPOTTY FLRYS/SPRINKLES. WE ADDED SOME VERY LGT SNOW ACCUMS PRIOR TO DAYBRK...OVER THE HIGHER TERRAIN OF NE PA AND THE CATSKILLS. WE`VE RECEIVED A COUPLE OF REPORTS OF A COATING OF SNOW THESE AREAS OVER THE PAST FEW HRS. MASSAGED NEAR-TERM TEMP GRIDS A BIT...TO BETTER REFLECT THE LATEST SFC OBS...AND ALSO BLEND IN THE MOST RECENT LAV TEMPS. 1000 PM UPDATE... A SHORT WAVE OVER NW PA AND WESTERN NY WILL CONTINUE TO MOVE NORTHEAST OVER THE CWA THROUGH EARLY WEDNESDAY MORNING. AN AREA OF LIGHT SNOW OVER NORTHERN PA WILL SLIDE NORTHEAST ACROSS THE CATSKILLS THROUGH 07Z. WITH SURFACE TEMPS NEAR OR ABOVE FREEZING...ONLY A DUSTING AT MOST IS EXPECTED IN THESE AREAS...WITH THE BEST CHANCE FOR THIS OCCURRING OVER THE HIGHEST TERRAIN. ASIDE FROM THIS AREA OF SNOW...THE REST OF THE NIGHT FOR MOST OF OUR AREA LOOKS VERY QUIET. A LOOK AT 0Z SOUNDINGS FROM BUFFALO AND PITTSBURGH ALONG WITH RUC FORECAST SOUNDINGS HAVE EASED THE CONCERN FOR FREEZING DRIZZLE OVERNIGHT SOMEWHAT. WHILE WE DO HAVE DRIER AIR WORKING INTO THE MID LEVELS...WE ARE STILL FAIRLY MOIST UP THROUGH -14C/-15C...SO WE SHOULD HAVE SOME ICE CRYSTALS TO WORK WITH. I NOTICED THAT MOST OF THE OBS TO THE WEST THAT REPORTED PLAIN DRIZZLE WERE IN CLOSE PROXIMITY TO THE LAKES...AND PROBABLY BEING INFLUENCED BY THEM. WHILE SOME PATCHY DRIZZLE HERE AND THEIR CAN`T ENTIRELY BE RULED OUT...THINKING THAT WHAT LITTLE PRECIP WE SEE FOR THE REST OF THE OVERNIGHT WILL BE JUST SOME SCT. FLURRIES. IT SEEMS OUR BEST SHOT AT A CHANGEOVER TO DRIZZLE WOULD BE MORE TOWARD MID-MORNING WEDNESDAY AS WE BEGIN TO DRY OUT DOWN TOWARD THE -10C LAYER. HOWEVER BY THE TIME THIS HAPPENS...BOUNDARY LAYER TEMPS WILL WARM ENOUGH THAT IT SHOULD NOT BE AN ISSUE. THE PREVIOUS AFD IS BELOW... 630 PM UPDATE... FORECAST LOOKS TO BE IN VERY GOOD SHAPE WITH CHANCE POPS ACROSS THE ENTIRE CWA THROUGH THE NEXT FEW HOURS. DESPITE RETURNS OF NEAR 20 DBZ ON RADAR...OBS ACROSS OUR AREA ARE SHOWING VERY...VERY LIGHT SNOW WITH VSBYS IN THE 4 TO 6SM RANGE. IN FACT ACROSS THE LOWER ELEVATIONS JUST SOME LIGHT RAIN OR DRIZZLE HAS BEEN REPORTED AT SYRACUSE AND AVOCA IS STILL 41! PRECIP WILL REMAIN LIGHT OVER THE NEXT FEW HOURS BUT AS THE BOUNDARY LAYER MOISTENS A BIT AND TEMPS COOL TO NEAR FREEZING WE MAY SEE A QUICK COATING OF SNOW OVER THE FAR NORTH (ONEIDA COUNTY). WE ARE ALREADY SEEING DRYING TO OUR WEST AND OUR NEXT CONCERN WILL BE THE CHANCE FOR SOME FREEZING DRIZZLE TONIGHT. THE PREVIOUS AFD ALREADY ADDRESSES THIS CONCERN AND WILL MONITOR AND UPDATE AS NEEDED LATER TONIGHT. SHORTWAVE ENERGY CURRENTLY LOCATED ACROSS THE EASTERN OHIO RVR VLY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. CURRENT REGIONAL RADAR IMAGERY DEPICTING MOST CONCENTRATED ACTIVITY ACROSS SOUTHERN PA...WITH LIGHTER ACTIVITY NOTED FURTHER TO THE NORTH. WITH TIME THIS EVENING...SHORTWAVE WILL PASS SOUTH OF THE REGION KEEPING THE BEST FORCING FOR ASCENT SOUTH OF THE CWA. THAT SAID...MAIN CONCERN WITH GOING FORECAST WILL BE INCREASING PROSPECTS FOR -FZDZ OVERNIGHT AS AFOREMENTIONED WAVE INTERACTS WITH AN APPROACHING ELEVATED FRONTAL BOUNDARY. BUFKIT SOUNDINGS INDICATE SUBSTANTIAL DRYING ALOFT AS WEAK UPPER RIDGING APPROACHES FROM THE WEST. AS THIS OCCURS...ICE CRYSTAL GROWTH POTENTIAL WILL DECREASE WITH LOSS OF SATURATION...THUS INTRODUCING THE POTENTIAL FOR -FZDZ ACROSS THE FORECAST AREA AS MOISTURE REMAINS CONFINED IN THE LOWEST 10KFT. WITH ONLY LIGHT QPF EXPECTED ACROSS THE FORECAST AREA OVERNIGHT...ANY -FZDZ THAT DEVELOPS WILL LIKELY BE PATCHY IN NATURE AND HAVE DECIDED TO JUST ADVERTISE POTENTIAL IN THE HWO PRODUCT FOR NOW. WITH ABUNDANT CLOUD COVER ALOFT...OVERNIGHT LOWS WILL REMAIN IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/... BY WED...SHORTWAVE ENERGY AND ELEVATED FRONT WILL BE DEPARTING TO OUR EAST AS WEAK UPPER RIDGING BUILDS ACROSS THE NORTHEAST IN ADVANCE OF A CENTRAL PLAINS TROUGH. DIFFICULT TO PIN DOWN HOW QUICKLY PRECIP WILL EXIT TO THE EAST WED MORNING...BUT MODEL INDICATIONS SUGGEST IMPROVING CONDITIONS THROUGH THE LATE MORNING/EARLY AFTERNOON. HAVE MAINTAINED SLGT CHC MENTION ACROSS THE EASTERN CWA DURING THE AFTERNOON HRS...WITH MAINLY DRY CONDITIONS EXPECTED WED NIGHT AREA WIDE AS SURFACE HIGH PRESSURE MOVES OVER THE AREA. HIGH TEMPS WED SHOULD WARM INTO THE UPPER 30S TO NEAR 40 ALONG AND WEST OF I-81...WITH COOLER VALUES EXPECTED TO THE EAST. AFOREMENTIONED PLAINS DISTURBANCE WILL THEN TAKE AIM AT THE REGION BY EARLY THU MORNING. PER CURRENT MODEL TRENDS...DRY NEAR SURFACE LAYER CONDITIONS WILL REQUIRE COLUMN SATURATION BEFORE PRECIP MAKES ITS WAY TO THE GROUND...AND HAVE ELECTED TO DELAY THE PRECIP ARRIVAL TIME BY A FEW HRS THU MORNING AS A RESULT. WHEN PRECIP DOES ARRIVE AFTER 12Z...MAIN CONCERN WILL BE PRECIP TYPE. HIGH PRESSURE MOVING OFF TO OUR EAST COMBINED WITH AN APPROACHING WARM FRONT SUGGEST WE MAY RECEIVE A BRIEF WINTRY MIX THU MORNING BEFORE BULK OF ACTIVITY TRANSITIONS INTO RA AS REGION GETS ENTRENCHED IN THE WARM SECTOR AHEAD OF MAIN COLD FRONT. CURRENT LOW TRACK TAKES LOW FROM NEAR DETROIT NORTHEAST TO NORTH BAY, ON WHICH CERTAINLY IS REMINISCENT OF ANY SIGNIFICANT MIXED PRECIP EVENTS. THAT SAID...MAIN AREA OF CONCERN WILL BE ACROSS THE WESTERN MOHAWK VALLEY WERE AGEOSTROPIC WIND CIRCULATIONS MAY KEEP COLD AIR ENTRENCHED FOR A LONGER PERIOD OF TIME. ALL TOLD...HAVE DECIDED TO ENTER A WINTRY MIX MENTION IN THE MORNING...WITH WITH A GRADUAL CHANGEOVER TO RA AS THE DAY PROGRESSES. WILL CERTAINLY HAVE TO WATCH TRENDS IN THE COMING DAYS TO PIN DOWN THE DETAILS AS THE EVENT NEARS. BY THU NIGHT...MUCH OF THE AREA WILL BE POST FRONTAL WITH COLD AIR ADVECTION SLOWLY WORKING INTO THE AREA. LAKE EFFECT POTENTIAL WILL BE ON THE INCREASE FRI AS WESTERLY WINDS DOWN THE LENGTH OF THE LAKE COMBINE WITH H85 TEMPS -11C. CURRENT BUFKIT PROFILES SUGGEST BEST POTENTIAL FOR ANYTHING SIGNIFICANT WILL BE NORTH OF CWA IN WELL ALIGNED 270-280 FLOW HOWEVER MEAGER INVERSION HEIGHTS HOWEVER MAY BE A LIMITING FACTOR. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE EXTENDED PERIOD BEGINS WITH SHARP DISAGREEMENT BETWEEN THE GFS AND EURO SOLUTIONS. EACH SHOW A NORTHEASTERN TROF. HOWEVER THE GFS SOLUTION CALLS FOR A VIGOROUS, SHARP TROF WITH A STRONG STACKED LOW OVER LAKE ERIE AND AN EVEN STRONGER STORM SOUTHEAST OF LONG ISLAND. THE EURO CALLS FOR A MUCH GENTLER TROF, WITH LITTLE IN THE WAY OF WEATHER REFLECTED. MODELS PHASE INTO STRONG AGREEMENT THAT A LARGE HIGH PRESSURE SYSTEM WILL BUILD ALONG THE COAST FOR MONDAY AND TUESDAY, WITH NOTICEABLE RIDGING ALOFT. THE RESULT WOULD BE MUCH ABOVE AVERAGE TEMPERATURES, AND CLEAR WEATHER. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... A WEAK TROF OF LOW PRESSURE IS MOVING THOUGH THE MID ATLANTIC REGION. LIGHT FOG AND VERY LIGHT PRECIPITATION WILL CONTINUE NORTH OF THE TROF, INTO NY AND PA. THIS WILL BRING MAINLY MVFR CONDITIONS TO THE REGION THROUGH THIS AFTERNOON. A PERIOD OF IFR CEILINGS IS EXPECTED AT BGM BETWEEN 7Z AND 12Z, WITH FORECAST CEILING HEIGHTS FLUCTUATING BETWEEN 700 AND 1200 FEET. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT LATER TODAY, ALLOWING THE ATMOSPHERE TO DRY, AND CONDITIONS TO IMPROVE. VISIBILITIES WILL BE QUICKEST TO REACH VFR TERRITORY BY LATE MORNING. VFR CEILINGS ARE EXPECTED TOWARD SUNSET. .OUTLOOK... WED NGT...VFR. THUR...IFR/MVFR IN -SHRA AND PSBLY SOME MIXED PCPN AT ONSET. FRI/SAT...MAINLY VFR. SUN...VFR...PSBL MVFR/IFR PA WITH SNOW. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG NEAR TERM...CMG/HEDEN/MLJ SHORT TERM...CMG LONG TERM...DJP AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
122 AM EST WED FEB 15 2012 .SYNOPSIS... A WEAK WEATHER DISTURBANCE MOVING OUT OF THE OHIO VALLEY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. LIGHT SNOW AND SCATTERED FLURRIES WILL BE POSSIBLE AS THIS HAPPENS. BY WEDNESDAY...CONDITIONS WILL BEGIN TO IMPROVE AS WEAK HIGH PRESSURE MOVES INTO THE AREA FROM THE WEST. BY THURSDAY...ANOTHER DISTURBANCE WILL BARE DOWN ON THE REGION WHICH WILL LEAD TO THE NEXT ROUND OF PRECIPITATION ACROSS NORTHEAST PENNSYLVANIA AND CENTRAL NEW YORK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1 AM UPDATE... THE CURRENT FCST IS IN GOOD SHAPE...SO ONLY MINOR TWEAKS WERE MADE TO IT. RADAR MOSAIC CONTS TO SHOW PATCHY -RA/-SN OVER MUCH OF THE FA ATTM. AS AN UPR-LVL WAVE PROGRESSES THROUGH THE RGN EARLY THIS MRNG...THIS PCPN SHOULD PERSIST TIL 09-12Z...BEFORE DIMINISHING TO SPOTTY FLRYS/SPRINKLES. WE ADDED SOME VERY LGT SNOW ACCUMS PRIOR TO DAYBRK...OVER THE HIGHER TERRAIN OF NE PA AND THE CATSKILLS. WE`VE RECEIVED A COUPLE OF REPORTS OF A COATING OF SNOW THESE AREAS OVER THE PAST FEW HRS. MASSAGED NEAR-TERM TEMP GRIDS A BIT...TO BETTER REFLECT THE LATEST SFC OBS...AND ALSO BLEND IN THE MOST RECENT LAV TEMPS. 1000 PM UPDATE... A SHORT WAVE OVER NW PA AND WESTERN NY WILL CONTINUE TO MOVE NORTHEAST OVER THE CWA THROUGH EARLY WEDNESDAY MORNING. AN AREA OF LIGHT SNOW OVER NORTHERN PA WILL SLIDE NORTHEAST ACROSS THE CATSKILLS THROUGH 07Z. WITH SURFACE TEMPS NEAR OR ABOVE FREEZING...ONLY A DUSTING AT MOST IS EXPECTED IN THESE AREAS...WITH THE BEST CHANCE FOR THIS OCCURRING OVER THE HIGHEST TERRAIN. ASIDE FROM THIS AREA OF SNOW...THE REST OF THE NIGHT FOR MOST OF OUR AREA LOOKS VERY QUIET. A LOOK AT 0Z SOUNDINGS FROM BUFFALO AND PITTSBURGH ALONG WITH RUC FORECAST SOUNDINGS HAVE EASED THE CONCERN FOR FREEZING DRIZZLE OVERNIGHT SOMEWHAT. WHILE WE DO HAVE DRIER AIR WORKING INTO THE MID LEVELS...WE ARE STILL FAIRLY MOIST UP THROUGH -14C/-15C...SO WE SHOULD HAVE SOME ICE CRYSTALS TO WORK WITH. I NOTICED THAT MOST OF THE OBS TO THE WEST THAT REPORTED PLAIN DRIZZLE WERE IN CLOSE PROXIMITY TO THE LAKES...AND PROBABLY BEING INFLUENCED BY THEM. WHILE SOME PATCHY DRIZZLE HERE AND THEIR CAN`T ENTIRELY BE RULED OUT...THINKING THAT WHAT LITTLE PRECIP WE SEE FOR THE REST OF THE OVERNIGHT WILL BE JUST SOME SCT. FLURRIES. IT SEEMS OUR BEST SHOT AT A CHANGEOVER TO DRIZZLE WOULD BE MORE TOWARD MID-MORNING WEDNESDAY AS WE BEGIN TO DRY OUT DOWN TOWARD THE -10C LAYER. HOWEVER BY THE TIME THIS HAPPENS...BOUNDARY LAYER TEMPS WILL WARM ENOUGH THAT IT SHOULD NOT BE AN ISSUE. THE PREVIOUS AFD IS BELOW... 630 PM UPDATE... FORECAST LOOKS TO BE IN VERY GOOD SHAPE WITH CHANCE POPS ACROSS THE ENTIRE CWA THROUGH THE NEXT FEW HOURS. DESPITE RETURNS OF NEAR 20 DBZ ON RADAR...OBS ACROSS OUR AREA ARE SHOWING VERY...VERY LIGHT SNOW WITH VSBYS IN THE 4 TO 6SM RANGE. IN FACT ACROSS THE LOWER ELEVATIONS JUST SOME LIGHT RAIN OR DRIZZLE HAS BEEN REPORTED AT SYRACUSE AND AVOCA IS STILL 41! PRECIP WILL REMAIN LIGHT OVER THE NEXT FEW HOURS BUT AS THE BOUNDARY LAYER MOISTENS A BIT AND TEMPS COOL TO NEAR FREEZING WE MAY SEE A QUICK COATING OF SNOW OVER THE FAR NORTH (ONEIDA COUNTY). WE ARE ALREADY SEEING DRYING TO OUR WEST AND OUR NEXT CONCERN WILL BE THE CHANCE FOR SOME FREEZING DRIZZLE TONIGHT. THE PREVIOUS AFD ALREADY ADDRESSES THIS CONCERN AND WILL MONITOR AND UPDATE AS NEEDED LATER TONIGHT. SHORTWAVE ENERGY CURRENTLY LOCATED ACROSS THE EASTERN OHIO RVR VLY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. CURRENT REGIONAL RADAR IMAGERY DEPICTING MOST CONCENTRATED ACTIVITY ACROSS SOUTHERN PA...WITH LIGHTER ACTIVITY NOTED FURTHER TO THE NORTH. WITH TIME THIS EVENING...SHORTWAVE WILL PASS SOUTH OF THE REGION KEEPING THE BEST FORCING FOR ASCENT SOUTH OF THE CWA. THAT SAID...MAIN CONCERN WITH GOING FORECAST WILL BE INCREASING PROSPECTS FOR -FZDZ OVERNIGHT AS AFOREMENTIONED WAVE INTERACTS WITH AN APPROACHING ELEVATED FRONTAL BOUNDARY. BUFKIT SOUNDINGS INDICATE SUBSTANTIAL DRYING ALOFT AS WEAK UPPER RIDGING APPROACHES FROM THE WEST. AS THIS OCCURS...ICE CRYSTAL GROWTH POTENTIAL WILL DECREASE WITH LOSS OF SATURATION...THUS INTRODUCING THE POTENTIAL FOR -FZDZ ACROSS THE FORECAST AREA AS MOISTURE REMAINS CONFINED IN THE LOWEST 10KFT. WITH ONLY LIGHT QPF EXPECTED ACROSS THE FORECAST AREA OVERNIGHT...ANY -FZDZ THAT DEVELOPS WILL LIKELY BE PATCHY IN NATURE AND HAVE DECIDED TO JUST ADVERTISE POTENTIAL IN THE HWO PRODUCT FOR NOW. WITH ABUNDANT CLOUD COVER ALOFT...OVERNIGHT LOWS WILL REMAIN IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... BY WED...SHORTWAVE ENERGY AND ELEVATED FRONT WILL BE DEPARTING TO OUR EAST AS WEAK UPPER RIDGING BUILDS ACROSS THE NORTHEAST IN ADVANCE OF A CENTRAL PLAINS TROUGH. DIFFICULT TO PIN DOWN HOW QUICKLY PRECIP WILL EXIT TO THE EAST WED MORNING...BUT MODEL INDICATIONS SUGGEST IMPROVING CONDITIONS THROUGH THE LATE MORNING/EARLY AFTERNOON. HAVE MAINTAINED SLGT CHC MENTION ACROSS THE EASTERN CWA DURING THE AFTERNOON HRS...WITH MAINLY DRY CONDITIONS EXPECTED WED NIGHT AREA WIDE AS SURFACE HIGH PRESSURE MOVES OVER THE AREA. HIGH TEMPS WED SHOULD WARM INTO THE UPPER 30S TO NEAR 40 ALONG AND WEST OF I-81...WITH COOLER VALUES EXPECTED TO THE EAST. AFOREMENTIONED PLAINS DISTURBANCE WILL THEN TAKE AIM AT THE REGION BY EARLY THU MORNING. PER CURRENT MODEL TRENDS...DRY NEAR SURFACE LAYER CONDITIONS WILL REQUIRE COLUMN SATURATION BEFORE PRECIP MAKES ITS WAY TO THE GROUND...AND HAVE ELECTED TO DELAY THE PRECIP ARRIVAL TIME BY A FEW HRS THU MORNING AS A RESULT. WHEN PRECIP DOES ARRIVE AFTER 12Z...MAIN CONCERN WILL BE PRECIP TYPE. HIGH PRESSURE MOVING OFF TO OUR EAST COMBINED WITH AN APPROACHING WARM FRONT SUGGEST WE MAY RECEIVE A BRIEF WINTRY MIX THU MORNING BEFORE BULK OF ACTIVITY TRANSITIONS INTO RA AS REGION GETS ENTRENCHED IN THE WARM SECTOR AHEAD OF MAIN COLD FRONT. CURRENT LOW TRACK TAKES LOW FROM NEAR DETROIT NORTHEAST TO NORTH BAY, ON WHICH CERTAINLY IS REMINISCENT OF ANY SIGNIFICANT MIXED PRECIP EVENTS. THAT SAID...MAIN AREA OF CONCERN WILL BE ACROSS THE WESTERN MOHAWK VALLEY WERE AGEOSTROPIC WIND CIRCULATIONS MAY KEEP COLD AIR ENTRENCHED FOR A LONGER PERIOD OF TIME. ALL TOLD...HAVE DECIDED TO ENTER A WINTRY MIX MENTION IN THE MORNING...WITH WITH A GRADUAL CHANGEOVER TO RA AS THE DAY PROGRESSES. WILL CERTAINLY HAVE TO WATCH TRENDS IN THE COMING DAYS TO PIN DOWN THE DETAILS AS THE EVENT NEARS. BY THU NIGHT...MUCH OF THE AREA WILL BE POST FRONTAL WITH COLD AIR ADVECTION SLOWLY WORKING INTO THE AREA. LAKE EFFECT POTENTIAL WILL BE ON THE INCREASE FRI AS WESTERLY WINDS DOWN THE LENGTH OF THE LAKE COMBINE WITH H85 TEMPS -11C. CURRENT BUFKIT PROFILES SUGGEST BEST POTENTIAL FOR ANYTHING SIGNIFICANT WILL BE NORTH OF CWA IN WELL ALIGNED 270-280 FLOW HOWEVER MEAGER INVERSION HEIGHTS HOWEVER MAY BE A LIMITING FACTOR. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL TROF OVER THE NORTHEAST ALONG WITH A WEAK SFC LOW MOVING THROUGH THE REGION ON SATURDAY. THESE FEATURES WILL BRING UNSETTLED WEATHER TO THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT. WILL CONTINUE WITH CHC POPS FOR SNOW SHOWERS ESPECIALLY OVER CENTRAL NEW YORK. SATURDAY AFTERNOON AS THE BOUNDARY LAYER WARMS THERE COULD BE A MIX OF RAIN AND SNOW SHOWERS. SUNDAY THROUGH TUESDAY AN UPPER LEVEL RIDGE BUILDS OVER THE NORTHEAST AS SFC HIGH PRES FROM CENTRAL CANADA DROPS SOUTH AND RESIDES OVER THE AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD. TEMPS THROUGH THE PERIOD WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMS. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... A WEAK TROF OF LOW PRESSURE IS MOVING THOUGH THE MID ATLANTIC REGION. LIGHT FOG AND VERY LIGHT PRECIPITATION WILL CONTINUE NORTH OF THE TROF, INTO NY AND PA. THIS WILL BRING MAINLY MVFR CONDITIONS TO THE REGION THROUGH THIS AFTERNOON. A PERIOD OF IFR CEILINGS IS EXPECTED AT BGM BETWEEN 7Z AND 12Z, WITH FORECAST CEILING HEIGHTS FLUCTUATING BETWEEN 700 AND 1200 FEET. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT LATER TODAY, ALLOWING THE ATMOSPHERE TO DRY, AND CONDITIONS TO IMPROVE. VISIBILITIES WILL BE QUICKEST TO REACH VFR TERRITORY BY LATE MORNING. VFR CEILINGS ARE EXPECTED TOWARD SUNSET. .OUTLOOK... WED NGT...VFR. THUR...IFR/MVFR IN -SHRA AND PSBLY SOME MIXED PCPN AT ONSET. FRI/SAT...MAINLY VFR. SUN...VFR...PSBL MVFR/IFR PA WITH SNOW. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG NEAR TERM...CMG/HEDEN/MLJ SHORT TERM...CMG LONG TERM...RRM AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1231 AM EST WED FEB 15 2012 .SYNOPSIS... A WEAK WEATHER DISTURBANCE MOVING OUT OF THE OHIO VALLEY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. LIGHT SNOW AND SCATTERED FLURRIES WILL BE POSSIBLE AS THIS HAPPENS. BY WEDNESDAY...CONDITIONS WILL BEGIN TO IMPROVE AS WEAK HIGH PRESSURE MOVES INTO THE AREA FROM THE WEST. BY THURSDAY...ANOTHER DISTURBANCE WILL BARE DOWN ON THE REGION WHICH WILL LEAD TO THE NEXT ROUND OF PRECIPITATION ACROSS NORTHEAST PENNSYLVANIA AND CENTRAL NEW YORK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1000 PM UPDATE... A SHORT WAVE OVER NW PA AND WESTERN NY WILL CONTINUE TO MOVE NORTHEAST OVER THE CWA THROUGH EARLY WEDNESDAY MORNING. AN AREA OF LIGHT SNOW OVER NORTHERN PA WILL SLIDE NORTHEAST ACROSS THE CATSKILLS THROUGH 07Z. WITH SURFACE TEMPS NEAR OR ABOVE FREEZING...ONLY A DUSTING AT MOST IS EXPECTED IN THESE AREAS...WITH THE BEST CHANCE FOR THIS OCCURRING OVER THE HIGHEST TERRAIN. ASIDE FROM THIS AREA OF SNOW...THE REST OF THE NIGHT FOR MOST OF OUR AREA LOOKS VERY QUIET. A LOOK AT 0Z SOUNDINGS FROM BUFFALO AND PITTSBURGH ALONG WITH RUC FORECAST SOUNDINGS HAVE EASED THE CONCERN FOR FREEZING DRIZZLE OVERNIGHT SOMEWHAT. WHILE WE DO HAVE DRIER AIR WORKING INTO THE MID LEVELS...WE ARE STILL FAIRLY MOIST UP THROUGH -14C/-15C...SO WE SHOULD HAVE SOME ICE CRYSTALS TO WORK WITH. I NOTICED THAT MOST OF THE OBS TO THE WEST THAT REPORTED PLAIN DRIZZLE WERE IN CLOSE PROXIMITY TO THE LAKES...AND PROBABLY BEING INFLUENCED BY THEM. WHILE SOME PATCHY DRIZZLE HERE AND THEIR CAN`T ENTIRELY BE RULED OUT...THINKING THAT WHAT LITTLE PRECIP WE SEE FOR THE REST OF THE OVERNIGHT WILL BE JUST SOME SCT. FLURRIES. IT SEEMS OUR BEST SHOT AT A CHANGEOVER TO DRIZZLE WOULD BE MORE TOWARD MID-MORNING WEDNESDAY AS WE BEGIN TO DRY OUT DOWN TOWARD THE -10C LAYER. HOWEVER BY THE TIME THIS HAPPENS...BOUNDARY LAYER TEMPS WILL WARM ENOUGH THAT IT SHOULD NOT BE AN ISSUE. THE PREVIOUS AFD IS BELOW... 630 PM UPDATE... FORECAST LOOKS TO BE IN VERY GOOD SHAPE WITH CHANCE POPS ACROSS THE ENTIRE CWA THROUGH THE NEXT FEW HOURS. DESPITE RETURNS OF NEAR 20 DBZ ON RADAR...OBS ACROSS OUR AREA ARE SHOWING VERY...VERY LIGHT SNOW WITH VSBYS IN THE 4 TO 6SM RANGE. IN FACT ACROSS THE LOWER ELEVATIONS JUST SOME LIGHT RAIN OR DRIZZLE HAS BEEN REPORTED AT SYRACUSE AND AVOCA IS STILL 41! PRECIP WILL REMAIN LIGHT OVER THE NEXT FEW HOURS BUT AS THE BOUNDARY LAYER MOISTENS A BIT AND TEMPS COOL TO NEAR FREEZING WE MAY SEE A QUICK COATING OF SNOW OVER THE FAR NORTH (ONEIDA COUNTY). WE ARE ALREADY SEEING DRYING TO OUR WEST AND OUR NEXT CONCERN WILL BE THE CHANCE FOR SOME FREEZING DRIZZLE TONIGHT. THE PREVIOUS AFD ALREADY ADDRESSES THIS CONCERN AND WILL MONITOR AND UPDATE AS NEEDED LATER TONIGHT. SHORTWAVE ENERGY CURRENTLY LOCATED ACROSS THE EASTERN OHIO RVR VLY WILL SLIDE SOUTH OF THE REGION OVERNIGHT. CURRENT REGIONAL RADAR IMAGERY DEPICTING MOST CONCENTRATED ACTIVITY ACROSS SOUTHERN PA...WITH LIGHTER ACTIVITY NOTED FURTHER TO THE NORTH. WITH TIME THIS EVENING...SHORTWAVE WILL PASS SOUTH OF THE REGION KEEPING THE BEST FORCING FOR ASCENT SOUTH OF THE CWA. THAT SAID...MAIN CONCERN WITH GOING FORECAST WILL BE INCREASING PROSPECTS FOR -FZDZ OVERNIGHT AS AFOREMENTIONED WAVE INTERACTS WITH AN APPROACHING ELEVATED FRONTAL BOUNDARY. BUFKIT SOUNDINGS INDICATE SUBSTANTIAL DRYING ALOFT AS WEAK UPPER RIDGING APPROACHES FROM THE WEST. AS THIS OCCURS...ICE CRYSTAL GROWTH POTENTIAL WILL DECREASE WITH LOSS OF SATURATION...THUS INTRODUCING THE POTENTIAL FOR -FZDZ ACROSS THE FORECAST AREA AS MOISTURE REMAINS CONFINED IN THE LOWEST 10KFT. WITH ONLY LIGHT QPF EXPECTED ACROSS THE FORECAST AREA OVERNIGHT...ANY -FZDZ THAT DEVELOPS WILL LIKELY BE PATCHY IN NATURE AND HAVE DECIDED TO JUST ADVERTISE POTENTIAL IN THE HWO PRODUCT FOR NOW. WITH ABUNDANT CLOUD COVER ALOFT...OVERNIGHT LOWS WILL REMAIN IN THE UPPER 20S TO LOWER 30S. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... BY WED...SHORTWAVE ENERGY AND ELEVATED FRONT WILL BE DEPARTING TO OUR EAST AS WEAK UPPER RIDGING BUILDS ACROSS THE NORTHEAST IN ADVANCE OF A CENTRAL PLAINS TROUGH. DIFFICULT TO PIN DOWN HOW QUICKLY PRECIP WILL EXIT TO THE EAST WED MORNING...BUT MODEL INDICATIONS SUGGEST IMPROVING CONDITIONS THROUGH THE LATE MORNING/EARLY AFTERNOON. HAVE MAINTAINED SLGT CHC MENTION ACROSS THE EASTERN CWA DURING THE AFTERNOON HRS...WITH MAINLY DRY CONDITIONS EXPECTED WED NIGHT AREA WIDE AS SURFACE HIGH PRESSURE MOVES OVER THE AREA. HIGH TEMPS WED SHOULD WARM INTO THE UPPER 30S TO NEAR 40 ALONG AND WEST OF I-81...WITH COOLER VALUES EXPECTED TO THE EAST. AFOREMENTIONED PLAINS DISTURBANCE WILL THEN TAKE AIM AT THE REGION BY EARLY THU MORNING. PER CURRENT MODEL TRENDS...DRY NEAR SURFACE LAYER CONDITIONS WILL REQUIRE COLUMN SATURATION BEFORE PRECIP MAKES ITS WAY TO THE GROUND...AND HAVE ELECTED TO DELAY THE PRECIP ARRIVAL TIME BY A FEW HRS THU MORNING AS A RESULT. WHEN PRECIP DOES ARRIVE AFTER 12Z...MAIN CONCERN WILL BE PRECIP TYPE. HIGH PRESSURE MOVING OFF TO OUR EAST COMBINED WITH AN APPROACHING WARM FRONT SUGGEST WE MAY RECEIVE A BRIEF WINTRY MIX THU MORNING BEFORE BULK OF ACTIVITY TRANSITIONS INTO RA AS REGION GETS ENTRENCHED IN THE WARM SECTOR AHEAD OF MAIN COLD FRONT. CURRENT LOW TRACK TAKES LOW FROM NEAR DETROIT NORTHEAST TO NORTH BAY, ON WHICH CERTAINLY IS REMINISCENT OF ANY SIGNIFICANT MIXED PRECIP EVENTS. THAT SAID...MAIN AREA OF CONCERN WILL BE ACROSS THE WESTERN MOHAWK VALLEY WERE AGEOSTROPIC WIND CIRCULATIONS MAY KEEP COLD AIR ENTRENCHED FOR A LONGER PERIOD OF TIME. ALL TOLD...HAVE DECIDED TO ENTER A WINTRY MIX MENTION IN THE MORNING...WITH WITH A GRADUAL CHANGEOVER TO RA AS THE DAY PROGRESSES. WILL CERTAINLY HAVE TO WATCH TRENDS IN THE COMING DAYS TO PIN DOWN THE DETAILS AS THE EVENT NEARS. BY THU NIGHT...MUCH OF THE AREA WILL BE POST FRONTAL WITH COLD AIR ADVECTION SLOWLY WORKING INTO THE AREA. LAKE EFFECT POTENTIAL WILL BE ON THE INCREASE FRI AS WESTERLY WINDS DOWN THE LENGTH OF THE LAKE COMBINE WITH H85 TEMPS -11C. CURRENT BUFKIT PROFILES SUGGEST BEST POTENTIAL FOR ANYTHING SIGNIFICANT WILL BE NORTH OF CWA IN WELL ALIGNED 270-280 FLOW HOWEVER MEAGER INVERSION HEIGHTS HOWEVER MAY BE A LIMITING FACTOR. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... THE EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL TROF OVER THE NORTHEAST ALONG WITH A WEAK SFC LOW MOVING THROUGH THE REGION ON SATURDAY. THESE FEATURES WILL BRING UNSETTLED WEATHER TO THE AREA FRIDAY NIGHT THROUGH SATURDAY NIGHT. WILL CONTINUE WITH CHC POPS FOR SNOW SHOWERS ESPECIALLY OVER CENTRAL NEW YORK. SATURDAY AFTERNOON AS THE BOUNDARY LAYER WARMS THERE COULD BE A MIX OF RAIN AND SNOW SHOWERS. SUNDAY THROUGH TUESDAY AN UPPER LEVEL RIDGE BUILDS OVER THE NORTHEAST AS SFC HIGH PRES FROM CENTRAL CANADA DROPS SOUTH AND RESIDES OVER THE AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD. TEMPS THROUGH THE PERIOD WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMS. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... A WEAK TROF OF LOW PRESSURE IS MOVING THOUGH THE MID ATLANTIC REGION. LIGHT FOG AND VERY LIGHT PRECIPITATION WILL CONTINUE NORTH OF THE TROF, INTO NY AND PA. THIS WILL BRING MAINLY MVFR CONDITIONS TO THE REGION THROUGH THIS AFTERNOON. A PERIOD OF IFR CEILINGS IS EXPECTED AT BGM BETWEEN 7Z AND 12Z, WITH FORECAST CEILING HEIGHTS FLUCTUATING BETWEEN 700 AND 1200 FEET. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT LATER TODAY, ALLOWING THE ATMOSPHERE TO DRY, AND CONDITIONS TO IMPROVE. VISIBILITIES WILL BE QUICKEST TO REACH VFR TERRITORY BY LATE MORNING. VFR CEILINGS ARE EXPECTED TOWARD SUNSET. .OUTLOOK... WED NGT...VFR. THUR...IFR/MVFR IN -SHRA AND PSBLY SOME MIXED PCPN AT ONSET. FRI/SAT...MAINLY VFR. SUN...VFR...PSBL MVFR/IFR PA WITH SNOW. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG NEAR TERM...CMG/HEDEN SHORT TERM...CMG LONG TERM...RRM AVIATION...DJP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
316 PM EST WED FEB 15 2012 .SYNOPSIS... HIGH PRESSURE WILL BE OVERHEAD TODAY THEN SHIFT EAST TONIGHT. A WEAK PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION THURSDAY AFTERNOON AND EVENING. && .NEAR TERM /TONIGHT/... AS OF 215 PM WEDNESDAY... THE SKIES CONTINUED SUNNY THIS AFTERNOON AS HIGH PRESSURE REMAINED IN CONTROL (CENTERED OVER VA/NC/SC). HIGHS 60-65 THIS AFTERNOON WITH LIGHT AND VARIABLE WINDS. IT NOW APPEARS THAT THE SIGNIFICANT CLOUDINESS WILL DEVELOP/OVERSPREAD OUR REGION LATER TONIGHT. THIS WILL GIVE MOST AREAS A CHANCE AT EXCELLENT RADIATIONAL COOLING DURING THE EVENING BEFORE THE CLOUDS BECOME THICK ENOUGH TO SLOW THE COOLING PROCESS. LOWS SHOULD OCCUR BETWEEN LATE EVENING AND 200 AM TO 400 AM... BEFORE LEVELING OFF. THE CURRENT PATTERN OF THE SKIES REMAINING CLEAR LONGER IN THE EAST FAVORS A NON-CLIMATOLOGICAL GEOGRAPHICAL PRESENTATION OF MINIMUM TEMPERATURES OVERNIGHT... WITH READINGS 30-35 IN THE NE AROUND ROCKY MOUNT AND HALIFAX... TO READINGS AT OR POSSIBLY ABOVE 40 IN THE YADKIN VALLEY OF THE WESTERN PIEDMONT. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 215 PM WEDNESDAY... HIGH CONFIDENCE IN RAIN ON THURSDAY...LOW CONFIDENCE IN AMOUNT. MODELS ARE IN GOOD OVERALL AGREEMENT IN THE FORECAST OF THE CURRENT MID-UPPER TROUGH CURRENTLY MOVING OUT OF TEXAS AND OKLAHOMA. CONVECTION HAS BEEN BLOSSOMING OVER SE TEXAS THIS AFTERNOON. THIS HAS BEEN HANDLED WELL THUS FAR BY THE 12Z GFS. ALL MODELS GENERALLY SHOW THE MID-UPPER TROUGH PROGRESSING QUICKLY ENE TOWARD OUR REGION TONIGHT AND THURSDAY. THE AFOREMENTIONED 12Z/GFS HAS PICKED UP ON THE CONVECTION FLARING UP ALREADY OVER SE TEXAS... AND HAS THIS CONVECTION SPREADING ENE ACROSS MS/AL AND GA OVERNIGHT THROUGH 12Z/THU. FROM THERE... MODELS DIVERGE ON POP/QPF OVER NC THURSDAY. THE LATEST GFS AND NOW THE LATEST EUROPEAN MODELS DEPICT ALMOST DOUBLE THE QPF OR RAINFALL AMOUNTS ACROSS MUCH OF OUR REGION THAN THE 12Z/NAM WITH THE EVENT. YET... THE HIGH RESOLUTION MODELS IN PARTICULAR THE SPC WRF AND THE HRRR DEPICT MINIMAL QPF OVER CENTRAL NC. THIS LACK OF QPF MAY BE THE WAY TO GO GIVEN THE NCEP MODELS TYPICAL FAILURE IN CAPTURING GULF COAST CONVECTION AND ITS ROLE IN DISRUPTING MOISTURE TRANSPORT INTO THE CAROLINAS UPSTREAM. HOWEVER... THE LATEST EURO SUPPORTS HEAVIER QPF ACROSS CENTRAL NC WITH THE CONVECTION FALLING APART AS IT SWEEPS ACROSS THE DEEP SOUTH LATE TONIGHT AND THURSDAY. WITH THIS IN MIND... WE WILL KEEP CURRENT CATEGORICAL POP IN PLACE... AND CONTINUE TO FORECAST RAINFALL AMOUNTS OF AROUND 0.25. IF CONVECTION DOES NOT SPREAD EAST ACROSS GA... AND THE DEEP MOISTURE TRANSPORT (35-45KT SSW FLOW 925-850MB) IN THE MODELS IS NOT DISRUPTED... THEN QPF OF UP TO A HALF INCH WOULD BE LIKELY. HIGHS SHOULD SHOW QUITE A RANGE WITH SOME LIGHT RAIN IN THE WEST EARLY... KEEPING HIGHS IN THE 50-55 RANGE. HIGHS SHOULD REACH THE LOWER 60S AROUND FAY TO GSB. THURSDAY NIGHT... SHOWERS WILL QUICKLY MOVE EAST WITH THE TROUGH... BUT LOW LEVEL MOISTURE WILL LAG PER THE LATEST MODELS. DEPENDING ON IF THE GROUND GETS WET OR NOT... FOG WILL/WILL NOT BE AN ISSUE. IF WE SQUEEZE OUT 0.10 OR SO... THEN FOG WILL BE LIKELY. OTHERWISE... PARTLY CLOUDY WITH LOWS 35-40. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY... FRIDAY AND FRIDAY NIGHT: A DEAMPLIFYING SHORTWAVE PROGRESSING EAST THROUGH THE MID-ATLANTIC ON THU (AND ITS ATTENDANT SFC LOW DEVELOPING OVER THE CAROLINAS) WILL MOVE OFFSHORE THU NIGHT. EXPECT CLEAR SKIES EVERYWHERE BY 12Z FRI MORNING AS DRY HIGH PRESSURE BUILDS INTO THE AREA FROM THE W/NW. HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE MID-ATLANTIC/CAROLINAS FROM DURING THE DAY FRI...AND IS PROGGED TO BE CENTERED NEAR THE MID-ATLANTIC COAST BY 12Z SAT. UNIFORM/FLAT FLOW ALOFT IS EXPECTED OVER THE CAROLINAS FRI THROUGH FRI NIGHT. WITH THE ABOVE IN MIND... EXPECT SUNNY SKIES DURING THE DAY FRI. 1000-850 MB THICKNESSES ARE PROGGED TO RANGE FROM 1335-1345 METERS N-S ON FRIDAY...SUGGESTING HIGHS RANGING FROM 59-65F OR SO...WARMEST NEAR THE SC BORDER. A LOW PRESSURE SYSTEM IS EXPECTED TO BEGIN DEVELOPING IN VICINITY OF THE TX GULF COAST LATE FRI NIGHT AS SHORTWAVE ENERGY CURRENTLY PROGRESSING SOUTH THROUGH CA/NV AMPLIFIES INTO A CLOSED UPPER LOW AND STARTS TRACKING EAST TOWARD WESTERN TX. IT IS POSSIBLE THAT SOME UPPER LEVEL CLOUD COVER COULD MOVE INTO THE CAROLINAS DOWNSTREAM OF PRECIPITATION EXPECTED ALONG THE GULF COAST STATES LATE FRI NIGHT... HOWEVER...THE LATEST MODEL GUIDANCE INDICATES THAT MOST OF THE INCREASE IN MID/UPPER LEVEL CLOUD COVER SHOULD HOLD OFF UNTIL AFTER SUNRISE SAT (WHEN PRECIP IS EXPECTED TO BLOSSOM OVER THE DEEP SOUTH)...WITH MINIMAL IMPACT ON LOW TEMPS. WILL FCST LOWS RANGING FROM THE LOWER/MID 30S TO UPPER 30S SAT MORNING...COLDEST IN THE TYPICAL SHELTERED/LOW-LYING AREAS...PARTICULARLY IN EAST/NE PORTIONS OF THE AREA. SATURDAY THROUGH SUNDAY NIGHT: SIGNIFICANT UNCERTAINTY PERSISTS W/REGARD TO THE EVOLUTION OF THE AFOREMENTIONED STORM SYSTEM AS IT TRACKS FROM THE TX GULF COAST THROUGH THE DEEP SOUTH AND INTO THE CAROLINAS/MID-ATLANTIC THIS WEEKEND. THE OPERATIONAL MODELS ARE HAVING A VERY DIFFICULT TIME DETERMINING HOW MUCH (IF ANY) PHASING WILL OCCUR BETWEEN THE SHORTWAVE ENERGY EJECTING EASTWARD FROM TX INTO THE DEEP SOUTH SAT/SAT NIGHT AND NORTHERN STREAM SHORTWAVE ENERGY DIVING SOUTHEAST FROM WESTERN CANADA THROUGH THE UPPER MIDWEST/GREAT LAKES INTO THE TN/OH VALLEYS. EXACTLY HOW THE NORTHERN/SOUTHERN STREAM SHORTWAVE ENERGY INTERACTS WILL IN LARGE PART DETERMINE THE SUBSEQUENT EVOLUTION OF THE LOW PRESSURE SYSTEM OVER AND OFFSHORE THE CAROLINAS THIS WEEKEND. AT THIS TIME...THE ECMWF IS STILL THE PREFERRED MODEL OF CHOICE GIVEN ITS CONSISTENCY AND BETTER TRACK RECORD...ALTHOUGH CONSIDERABLE UNCERTAINTY PERSISTS EVEN WITH THE ECMWF DUE TO THE COMPLEX NATURE OF THE UPPER LEVEL PATTERN AND THAT SOME OF THE KEY FEATURES WILL NOT BE SAMPLED WELL BY THE RAOB NETWORK UNTIL LATER THIS WEEK. WITH THE ABOVE IN MIND...ASIDE FROM INTRODUCING PRECIP CHANCES FROM SW-NE SATURDAY AFTERNOON (A BIT EARLIER THAN PREVIOUSLY INDICATED)...WILL MAKE FEW CHANGES TO THE CURRENT FORECAST FOR SATURDAY THROUGH SUNDAY NIGHT. MONDAY THROUGH WEDNESDAY: THERE IS REASONABLE AGREEMENT AMONG THE LONG TERM MODELS THAT DRY HIGH PRESSURE WILL BUILD INTO THE CAROLINAS IN THE WAKE OF THE LOW PRESSURE SYSTEM DEPARTING THE CAROLINA COAST SUN/SUN NIGHT...AND AT THIS TIME EXPECT DRY CONDITIONS WITH SUNNY SKIES AND HIGHS NEAR NORMAL IN THE LOWER/MID 50S...WITH LOWS MON NIGHT IN THE LOWER 30S. UNCERTAINTY GROWS AGAIN BY MID-WEEK IN ADVANCE OF THE NEXT SYSTEM EXPECTED TO APPROACH THE AREA FROM THE WEST LATE TUE NIGHT INTO WED. AT THIS TIME...WILL KEEP THE FCST DRY ON TUE WITH HIGH PRESSURE SLOWLY SHIFTING OFFSHORE THE CAROLINAS. A WARM/MOIST SOUTHERLY RETURN FLOW IS PROGGED TO DEVELOP BY TUE NIGHT/WED AS HIGH PRESSURE MOVES OFFSHORE IN ADVANCE OF THE NEXT SYSTEM PROGGED TO APPROACH THE AREA BY MID-WEEK...AND WILL INTRODUCE A 30% CHANCE FOR SHOWERS ON WED. -VINCENT && .AVIATION /18Z WEDNESDAY THROUGH SUNDAY/... AS OF 115 PM WEDNESDAY... VFR CONDITIONS WILL PERSIST UNDER HIGH PRESSURE THROUGH THIS EVENING. OVERNIGHT... VFR OVERCAST CONDITIONS WILL OVERSPREAD OUR REGION OVERNIGHT. RAIN IS EXPECTED TO DEVELOP AROUND 10Z-13Z IN THE WEST... THEN SPREAD EAST DURING THE DAY. CIGS/VSBYS WILL BECOME IFR WITH RAIN AND FOG MUCH OF THE DAY THURSDAY. OUTLOOK: AREAS OF MVFR THEN IFR FOG IS EXPECTED THURSDAY NIGHT AFTER THE CIGS LIFT IN THE EVENING. AREAS OF FOG EARLY FRIDAY WILL BECOME VFR VSBYS BY 15Z. THERE IS INCREASING CHANCE OF WIDESPREAD RAIN WITH IFR CIGS/VSBYS AS ANOTHER SYSTEM APPROACHES OUR REGION SAT-SUN. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...BADGETT SHORT TERM...BADGETT LONG TERM...VINCENT AVIATION...BADGETT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 PM EST WED FEB 15 2012 .SYNOPSIS... HIGH PRESSURE WILL BE OVERHEAD TODAY THEN SHIFT EAST TONIGHT. A WEAK PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION THURSDAY AFTERNOON AND EVENING. && .NEAR TERM /TONIGHT/... AS OF 215 PM WEDNESDAY... THE SKIES CONTINUED SUNNY THIS AFTERNOON AS HIGH PRESSURE REMAINED IN CONTROL (CENTERED OVER VA/NC/SC). HIGHS 60-65 THIS AFTERNOON WITH LIGHT AND VARIABLE WINDS. IT NOW APPEARS THAT THE SIGNIFICANT CLOUDINESS WILL DEVELOP/OVERSPREAD OUR REGION LATER TONIGHT. THIS WILL GIVE MOST AREAS A CHANCE AT EXCELLENT RADIATIONAL COOLING DURING THE EVENING BEFORE THE CLOUDS BECOME THICK ENOUGH TO SLOW THE COOLING PROCESS. LOWS SHOULD OCCUR BETWEEN LATE EVENING AND 200 AM TO 400 AM... BEFORE LEVELING OFF. THE CURRENT PATTERN OF THE SKIES REMAINING CLEAR LONGER IN THE EAST FAVORS A NON-CLIMATOLOGICAL GEOGRAPHICAL PRESENTATION OF MINIMUM TEMPERATURES OVERNIGHT... WITH READINGS 30-35 IN THE NE AROUND ROCKY MOUNT AND HALIFAX... TO READINGS AT OR POSSIBLY ABOVE 40 IN THE YADKIN VALLEY OF THE WESTERN PIEDMONT. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 215 PM WEDNESDAY... HIGH CONFIDENCE IN RAIN ON THURSDAY... LOW CONFIDENCE IN AMOUNT. MODELS ARE IN GOOD OVERALL AGREEMENT IN THE FORECAST OF THE CURRENT MID-UPPER TROUGH CURRENTLY MOVING OUT OF TEXAS AND OKLAHOMA. CONVECTION HAS BEEN BLOSSOMING OVER SE TEXAS THIS AFTERNOON. THIS HAS BEEN HANDLED WELL THUS FAR BY THE 12Z GFS. ALL MODELS GENERALLY SHOW THE MID-UPPER TROUGH PROGRESSING QUICKLY ENE TOWARD OUR REGION TONIGHT AND THURSDAY. THE AFOREMENTIONED 12Z/GFS HAS PICKED UP ON THE CONVECTION FLARING UP ALREADY OVER SE TEXAS... AND HAS THIS CONVECTION SPREADING ENE ACROSS MS/AL AND GA OVERNIGHT THROUGH 12Z/THU. FROM THERE... MODELS DIVERGE ON POP/QPF OVER NC THURSDAY. THE LATEST GFS AND NOW THE LATEST EUROPEAN MODELS DEPICT ALMOST DOUBLE THE QPF OR RAINFALL AMOUNTS ACROSS MUCH OF OUR REGION THAN THE 12Z/NAM WITH THE EVENT. YET... THE HIGH RESOLUTION MODELS IN PARTICULAR THE SPC WRF AND THE HRRR DEPICT MINIMAL QPF OVER CENTRAL NC. THIS LACK OF QPF MAY BE THE WAY TO GO GIVEN THE NCEP MODELS TYPICAL FAILURE IN CAPTURING GULF COAST CONVECTION AND ITS ROLE IN DISRUPTING MOISTURE TRANSPORT INTO THE CAROLINAS UPSTREAM. HOWEVER... THE LATEST EURO SUPPORTS HEAVIER QPF ACROSS CENTRAL NC WITH THE CONVECTION FALLING APART AS IT SWEEPS ACROSS THE DEEP SOUTH LATE TONIGHT AND THURSDAY. WITH THIS IN MIND... WE WILL KEEP CURRENT CATEGORICAL POP IN PLACE... AND CONTINUE TO FORECAST RAINFALL AMOUNTS OF AROUND 0.25. IF CONVECTION DOES NOT SPREAD EAST ACROSS GA... AND THE DEEP MOISTURE TRANSPORT (35-45KT SSW FLOW 925-850MB) IN THE MODELS IS NOT DISRUPTED... THEN QPF OF UP TO A HALF INCH WOULD BE LIKELY. HIGHS SHOULD SHOW QUITE A RANGE WITH SOME LIGHT RAIN IN THE WEST EARLY... KEEPING HIGHS IN THE 50-55 RANGE. HIGHS SHOULD REACH THE LOWER 60S AROUND FAY TO GSB. THURSDAY NIGHT... SHOWERS WILL QUICKLY MOVE EAST WITH THE TROUGH... BUT LOW LEVEL MOISTURE WILL LAG PER THE LATEST MODELS. DEPENDING ON IF THE GROUND GETS WET OR NOT... FOG WILL/WILL NOT BE AN ISSUE. IF WE SQUEEZE OUT 0.10 OR SO... THEN FOG WILL BE LIKELY. OTHERWISE... PARTLY CLOUDY WITH LOWS 35-40. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 250 AM... ZONAL FLOW ALOFT FRIDAY AND FRIDAY NIGHT AS WEAK SURFACE HIGH PRESSURE COVERS THE EAST COAST. LOW LEVEL THICKNESSES AT LEAST FIFTEEN METERS ABOVE NORMAL FRIDAY AFTERNOON. WEAK DOWNSLOPE FLOW SHOULD MARGINALLY RAISE TEMPERATURES IN THE WEST. AFTERNOON HIGH TEMPERATURES 61 TO 65. LIGHT WINDS FRIDAY NIGHT AND A LITTLE INCREASE IN AIR COLUMN MOISTURE OVERNIGHT. LOW TEMPERATURES IN THE MID 30S WITH COLDEST SPOTS BELOW FREEZING. THE POTENTIAL FOR A WEEKEND PRECIPITATION EVENT CONTINUES IN THE MODELS WITH A WIDE DIVERGENCE IN SOLUTIONS. A SHORT WAVE DROPPING SOUTH INTO THE GREAT BASIN THIS MORNING IS FORECAST TO REACH WEST TEXAS FRIDAY AFTERNOON BY THE ECMWF AND GFS... BUT TIMINGS IS SLOWER WITH THE NAM AND CANADIAN. THE WELL INLAND TRACK OF THE SURFACE LOW ON THE GFS IS NOT CLIMATOLOGICALLY FAVORED AND A SOLUTION CLOSER TO THE 00Z NAM AND ECMWF WILL BE FOLLOWED. FORECAST OF A DRY SATURDAY WITH CHANCE POPS WELLING UP FROM THE SOUTH SATURDAY NIGHT ACCEPTED... AND FIFTY PERCENT RAIN CHANCES SUNDAY. SEE NO REASON TO ALTER A FORECAST OF RAIN FOR THIS SYSTEM. COLD AIR WILL NOT BE IN PLACE PRIOR TO THE SYSTEMS ARRIVAL AND ANY COLD AIR WOULD HAVE TO BE PULLED DOWN BY THE LOW PRESSURE SYSTEM AND THIS IS A SCENARIO FOR COLD AIR CHASING EXITING MOISTURE. FREEZING LEVELS COULD POTENTIALLY BE LOW ENOUGH AS THE LAST BIT OF RAIN EXITS TO ALLOW FOR SOMETHING OTHER THAN RAIN. GIVEN THE MODEL UNCERTAINTY... KNOWN MODEL COLD BIAS AND THE SCENARIO ABOVE FAVORING RAIN... THAT FORECAST WILL CONTINUE. DRIER AND COLDER BEHIND THE EXITING LOW FOR MONDAY... WITH TEMPERATURES RECOVERING TUESDAY. CLOUDS WILL INTERFERE WITH INSOLATION SATURDAY... AND MID TO UPPER 50S FORECAST FOR HIGH TEMPERATURES. FORECAST HIGH TEMPERATURES OF MID 40S TO LOWER 50S SUNDAY REFLECT A TEN DEGREE DIURNAL RISE FROM MORNING LOWS... AND WOULD BE TOO WARM IF WIDESPREAD RAINS OCCUR BY MID MORNING. HIGH TEMPERATURES NEAR 50 NORTHEAST TO NEAR 55 SOUTHWEST MONDAY... UPPER 50S TO LOWER 60S TUESDAY. LOW TEMPERATURES IN THE MID 30S FRIDAY NIGHT... WARMING TO MID 30S TO LOWER 40S SATURDAY NIGHT WITH INCREASING CLOUDS AND A CHANCE FOR RAIN. LOW TEMPERATURES IN THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST SUNDAY NIGHT... LOW TO MID 30S MONDAY NIGHT. && .AVIATION /18Z WEDNESDAY THROUGH SUNDAY/... AS OF 115 PM WEDNESDAY... VFR CONDITIONS WILL PERSIST UNDER HIGH PRESSURE THROUGH THIS EVENING. OVERNIGHT... VFR OVERCAST CONDITIONS WILL OVERSPREAD OUR REGION OVERNIGHT. RAIN IS EXPECTED TO DEVELOP AROUND 10Z-13Z IN THE WEST... THEN SPREAD EAST DURING THE DAY. CIGS/VSBYS WILL BECOME IFR WITH RAIN AND FOG MUCH OF THE DAY THURSDAY. OUTLOOK: AREAS OF MVFR THEN IFR FOG IS EXPECTED THURSDAY NIGHT AFTER THE CIGS LIFT IN THE EVENING. AREAS OF FOG EARLY FRIDAY WILL BECOME VFR VSBYS BY 15Z. THERE IS INCREASING CHANCE OF WIDESPREAD RAIN WITH IFR CIGS/VSBYS AS ANOTHER SYSTEM APPROACHES OUR REGION SAT-SUN. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...BADGETT SHORT TERM...BADGETT LONG TERM...99 AVIATION...BADGETT
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1034 AM CST WED FEB 15 2012 .DISCUSSION... 16 UTC WSR-88D RADARS STILL SHOWING TWO AREAS OF LIGHT SNOW ASSOCIATED WITH COMPACT VORT MOVING ACROSS NORTH CENTRAL ND. THE FIRST IS ACROSS THE DEVILS LAKE BASIN AND THE SECOND IS ENTERING THE SOUTHERN VALLEY. THERE HAVE A BEEN A COUPLE REPORTS OF VISIBILITY TO 1 SM ACROSS THE NORTH...SO WILL KEEP POPS IN THE 60 TO 80 PERCENT RANGE THROUGH THE DAY. ANY ACCUMULATION WILL BE AN INCH OR LESS. FARTHER SOUTH...DID INCREASE POPS INTO THE CHANCE CATEGORY THROUGH THE AFTERNOON GIVEN STRONGER ECHOES ENTERING RANSOM/SARGENT/RICHLAND COUNTIES. LATEST HRRR SEEMS TO BE HANDLING THIS AREA OF SNOW THE BEST AND BRINGS IT ACROSS WEST CENTRAL MN THIS AFTERNOON. ANY ACCUMULATION HERE SHOULD ALSO BE LESS THAN AN INCH. CLOUD COVER WILL KEEP A LID ON TEMPERATURES WITH AFTERNOON HIGHS IN THE LOWER TO MID 30S. MODEL SOUNDINGS SUGGEST LOW-LEVEL MELTING LAYER IS QUITE SHALLOW...SO WILL CONTINUE WITH ALL SNOW FOR PRECIPITATION TYPE. OVERALL...FORECAST IS IN GOOD SHAPE WITH NO MAJOR CHANGES NEEDED AT THIS TIME. && .AVIATION... A SHORTWAVE TROUGH MOVING THROUGH WILL BRING SOME MVFR CEILINGS AND -SN TO MAINLY THE NORTHERN CWA TODAY. KDVL WILL GO DOWN BELOW VFR IN THE NEXT HOUR OR TWO...WITH KGFK AND POSSIBLY KTVF AND KBJI AFFECTED. THE SNOW COULD BRING VIS DOWN TO AROUND 1 TO 2SM AT TIMES...BUT THINK THAT IT WILL BE SHORT LIVED AND WILL COVER WITH TEMPO GROUPS. CONDITIONS SHOULD RETURN TO VFR BY THIS EVENING AS THE SHORTWAVE MOVES OFF TO THE EAST. WINDS WILL REMAIN PRIMARILY FROM THE WEST AT 12 KTS OR LESS. && .PREV DISCUSSION... /ISSUED 318 AM CST WED FEB 15 2012/ SHORT TERM...WATER VAPOR IMAGERY INDICATES MULTIPLE CIRCULATIONS APPROACHING THE REGION OVER THE NEXT FEW DAYS. ECMWF HAS DONE BEST WITH TEMPS AND PRECIP OVER THE PAST COUPLE DAYS AND WILL FOLLOW FOR DETAILS. FIRST UPPER CIRCULATION ABOUT TO EXIT THE SE FA...BUT SCATTERED SNOW SHOWERS COULD PRODUCE MINOR ACCUMULATION THROUGH 12Z HERE. NEXT UPPER TROUGH WITH A FEW CIRCULATIONS WILL AFFECT THE FA TODAY. RADAR SHOWS TWO MAIN AREAS OF PRECIP ASSOCIATED WITH SHORTWAVES ON WATER VAPOR IMAGERY...ONE AREA ACROSS NORTH CENTRAL NORTH DAKOTA AND ANOTHER ACROSS CENTRAL SOUTH DAKOTA. THE NORTHERN AREA OF PRECIP (SNOW) WILL MOVE ACROSS THE NORTHERN FA (ALONG AND NORTH OF A NEW ROCKFORD TO GRAND FORKS TO BAUDETTE LINE). THINKING UP TO AN INCH OF SNOWFALL ACROSS THIS AREA...AND INCREASED POPS INTO THE LIKELY/DEFINITE RANGE. NOT QUITE SURE WHAT IS GOING TO OCCUR SOUTH OF THIS AREA. HRRR/ECMWF INDICATES THAT THE SOUTHERN AREA OF PRECIP WILL PROPAGATE TO THE NORTHEAST...AND AFFECT THE SOUTHERN FA TODAY. INSERTED 20 POPS AND WILL MONITOR RADAR/OBS FOR FUTURE UPDATES. P-TYPE SHOULD BE SNOW GIVEN ANY ABOVE FREEZING LAYER WILL BE VERY SHALLOW NEAR THE GROUND. CLOUD COVER SHOULD LIMIT MAX TEMPS TODAY...BUT GIVEN WARM START LOW-MID 30S ARE OBTAINABLE. SNOW WILL LINGER ACROSS THE NE FA OVERNIGHT. THERE IS POTENTIAL FOR CLEARING ACROSS THE WESTERN FA...WITH MIN TEMPS INTO THE TEENS. OTHERWISE...MIN TEMPS NEAR 20F ELSEWHERE WITH CLOUD COVER. THUR-FRI NIGHT...SIMILAR PATTERN CONTINUES. THUR COULD BE SIMILAR TO PAST COUPLE DAYS WITH CLEARING POTENTIAL AND WESTERLY SFC WINDS. SLIGHTLY COLDER AIRMASS ASSOCIATED WITH ANOTHER SHORTWAVE ARRIVES BY FRIDAY...WITH CLEARING AND LIGHT WINDS POSSIBLE FRIDAY NIGHT. NOT MUCH CHANGE NEEDED TO THE FORECAST FOR THIS PERIOD. LONG TERM (SAT-TUE)...SIMILAR PATTERN WILL CONTINUE INTO THIS PERIOD. MAIN SYSTEM OF CONCERN WILL BE MONDAY. UNCERTAINTY REGARDING DEGREE OF PHASING BETWEEN NORTHERN AND SOUTHERN STREAM. 00Z GFS/ECMWF INDICATE SOME PHASING...BUT KEEP MAJORITY OF PRECIP TO THE SOUTH. TEMPERATURES ABOVE NORMAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ ROGERS/JR/TG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
632 AM EST WED FEB 15 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE ACROSS THE AREA TODAY AND REACH THE EAST COAST THURSDAY MORNING. A COLD FRONT OVER THE PLAINS STATES WILL MOVE ACROSS OHIO AND WESTERN PENNSYLVANIA THURSDAY. HIGH PRESSURE WILL BEGIN BUILDING INTO THE REGION THURSDAY NIGHT AND WILL MOVE ACROSS THE AREA FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGH PRESSURE WAS BUILDING INTO THE AREA THIS MORNING. THE LIGHT PRECIPITATION/FLURRIES/FREEZING DRIZZLE CONTINUES TO DECREASE AS PER THE RADAR AND THE OBSERVATIONS. WILL CONTINUE WITH A THREAT OF IT EAST OF CLEVELAND AND AKRON THROUGH THE MORNING COMMUTE. OTHERWISE THE LOW CLOUDS WILL EVENTUALLY GO AWAY BUT WILL BE REPLACED BY MID CLOUDS. A LITTLE SUN COULD OCCUR...HOWEVER...MOSTLY CLOUDY SHOULD HANDLE IT. HIGH TEMPERATURES ARE A LITTLE TRICKY...SINCE THE CLOUD COVER IS A LITTLE IN QUESTION. USED A COMPROMISE OF THE MOS GUIDANCE. THE HRRR MODEL IS TRYING TO INDICATE SOME RAIN COULD MOVE INTO THE FINDLAY AND MARION AREAS LATE THIS AFTERNOON. RADAR UPSTREAM IS INDICATING ISOLATED LIGHT SHOWERS. WILL FORECAST SPRINKLES LATE THIS AFTERNOON FOR NORTHWEST OHIO. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... RAIN WILL SPREAD EAST FAIRLY RAPIDLY ACROSS THE AREA TONIGHT. TEMPERATURES AND THICKNESS AND A SOUTHWEST FLOW INDICATE THAT THE PRECIPITATION SHOULD BE ALL RAIN. THE NAM SEEMS TOO SLOW BASED ON THE RADAR AND THE SOMEWHAT FAST FLOW. THE RAIN WILL DECREASE AFTER THE FRONTAL PASSAGE. THE FRONT WILL MOVE THROUGH NORTHWEST OHIO IN THE MORNING AND ELSEWHERE THROUGH THE AFTERNOON AND EVENING. SPC HAS THE AREA IN GENERAL THUNDER FOR THURSDAY. AT THIS TIME WILL NOT MENTION IT AS THE AIRMASS DOESN`T SEEM UNSTABLE ENOUGH...BUT IT WILL HAVE TO BE MONITORED. RAINFALL AMOUNTS SHOULD UNDER HALF AN INCH AND EVEN THE IMPACT FROM THE SNOW MELT SHOULD ONLY BE ENOUGH TO CAUSE RISES IN STREAMS...CREEKS AND RIVERS. SOME COULD APPROACH BANKFULL. TEMPERATURES WILL NOT DROP MUCH TONIGHT AND MAY RISE A DEGREE OR TWO. HIGHS ARE TOUGH ON THURSDAY...ESPECIALLY IF THE RAIN IS SOMEWHAT CONTINUOUS. STAYED ON THE COOLER SIDE. SOME LAKE EFFECT SNOW SHOWERS COULD DEVELOP LATE THURSDAY NIGHT AND CONTINUE INTO FRIDAY. NOT EXPECTING MUCH OF AN IMPACT AS THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL BE ONLY AROUND 8 OR 9C AND THE AIRMASS IS REALLY DRYING OUT. ELSEWHERE JUST SOME CLOUDS AND THE AMOUNT OF CLOUDS IS IN QUESTION. HIGH PRESSURE WILL BEGIN TO MOVE ACR0SS THE REGION FRIDAY. THE MODELS AGREE WITH ANOTHER COLD FRONT MOVING THROUGH ON SATURDAY BUT THE GFS IS MUCH STRONGER WITH IT THEN THE ECMWF. AT THIS TIME WILL CONTINUE THE DRIER TREND. && .LONG TERM /SUNDAY THROUGH TUESDAY/... MODELS STILL NOT IN AGREEMENT ON SUNDAY. GFS MAINTAINS A COASTAL LOW OFF THE MID ATLANTIC COAST SUNDAY AFTERNOON WITH A TROUGH ACROSS THE EASTERN LAKES. THE ECMWF ON THE OTHER HAND HAS THE COASTAL LOW MUCH FURTHER SOUTH WITH HIGH PRESSURE OVER THE GREAT LAKES. HPC PREFERS THE ECMWF WHICH LOOKS REASONABLE AT THIS POINT. ACTUALLY BOTH MODELS IN GOOD AGREEMENT WITH HIGH PRESSURE CENTERED OVER THE GREAT LAKES MONDAY. BOTH MODELS BRING LOW PRESSURE SYSTEM ACROSS CENTRAL LAKES TUESDAY...WITH THE GFS BEING THE FASTER OF THE 2 MODELS. LEANED TOWARD THE SLOWER ECMWF FOR NOW. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... PATCHY FREEZING DRIZZLE FROM YNG EAST WILL END BY MID MORNING. MVFR CIGS WILL LINGER THROUGH THE MORNING PUSH. CONDITIONS WILL SLOWLY IMPROVE TO VFR FROM THE SW DURING THE AFTERNOON. OUTLOOK...NON VFR CONDITIONS RETURN OVERNIGHT WITH RAIN DEVELOPING AFTER MIDNIGHT. RAIN WILL CONTINUE INTO THURSDAY AFTERNOON. NON VFR WILL LINGER ACROSS NE OH/NW PA FROM THURSDAY EVENING INTO FRIDAY WITH SNOW SHOWERS. && .MARINE... ANOTHER DAY WITH LIGHT SOUTHERLY FLOW. SMALL CRAFT ADVISORY WILL BE NEEDED THURSDAY. LOW PRESSURE MOVES ACROSS THE CENTRAL LAKES TOMORROW DRAGGING A STRONG COLD FRONT ACROSS THE LAKE. MODELS STILL DIFFER ON THE EXACT TRACK AND TIMING OF THE LOW BUT IN ANY CASE A WEST TO NORTHWEST FLOW OF 15 TO 25 KNOTS DEVELOPS BEHIND THE FRONT. SMALL CRAFT WILL BE NEEDED UNTIL LATE FRIDAY AS HIGH PRESSURE BUILDS OVER THE LAKE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...DJB AVIATION...DJB MARINE...DJB
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1131 AM CST WED FEB 15 2012 .UPDATE... DRYLINE PUSHING EASTWARD WILL MOVE EAST OF THE I-35 CORRIDOR BY EARLY AFTERNOON. CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON EAST OF THE DRYLINE THOUGH SEVERE THREAT LOOKS MINIMAL. A FEW STORMS MAY BECOME STRONG WITH GUSTY WINDS AND SMALL HAIL THE MAIN THREAT. DID LOWER TEMPS A FEW DEGREES OVER THE EASTERN SECTIONS AS CLOUDS LOOK TO HANG AROUND THROUGH THIS EVENING. BEHIND THE DRY LINE...ELEVATED FIRE WEATHER THREAT WILL CONTINUE WITH GUSTY WEST WINDS AND DECREASING RELATIVE HUMIDITY. 99 && .AVIATION... CONCERNS... IFR AND LIFR CEILINGS THIS MORNING...CROSSWIND PROBLEMS AT THE METROPLEX TAF SITES THIS AFTERNOON...AND MVFR/IFR CEILINGS RETURNING THURSDAY MORNING. IFR CEILINGS ARE PREVAILING AT THE METROPLEX TAF SITES THIS MORNING WITH LIFR CIGS AND VISBY AT KACT. HOWEVER...SATELLITE IMAGERY SHOWS THE LOW ALREADY ERODING TO THE WEST OF THE METROPLEX AS DRY AIR AT 850 MB MOVES ACROSS THE REGION. BASED ON THE LATEST TRENDS AND GUIDANCE FROM THE RUC MODEL...IT APPEARS THE IFR CIGS WILL IMPROVE INTO VFR CONDITIONS BETWEEN 12-13Z AS THIS DRIER AIR AT 850 MB REACHES THE METROPLEX. AT KACT...EXPECT LIFR CONDITIONS TO PERSIST THROUGH 15Z AND IMPROVE TO MVFR FOR THE REMAINDER OF THE MORNING. LIGHT SHOWERS ARE INCREASING IN COVERAGE ACROSS THE REGION AND WILL CARRY VCSH AT ALL THE TAF SITES FOR MUCH OF THE MORNING. WHILE AN ISOLATED THUNDERSTORM CANNOT BE COMPLETELY RULED OUT THIS MORNING...THE THREAT IS TOO LOW TO CONTINUE THE CB MENTION IN THE TAF...EXCEPT FOR AT KACT FROM 16-18Z. A DRYLINE WILL REACH THE I-35 CORRIDOR AROUND 20Z WITH WEST WINDS OF 15G25KT OCCURRING AT THE METROPLEX TAF SITES BUT LESSER WINDS AROUND 12-14 KTS AT KACT. THE GUSTY WEST WINDS IN THE METROPLEX WILL CREATE SOME CROSSWIND PROBLEMS. THERE IS A SMALL CHANCE THAT A FEW ADDITIONAL THUNDERSTORMS MAY OCCUR ALONG THE DRYLINE AS IT REACHES THE TAF SITES THIS AFTERNOON BUT THE POTENTIAL IS LOW AT THIS TIME AND WILL NOT MENTION A CB GROUP IN THE TAF WITH THIS ISSUANCE. THE WIND SPEEDS WILL SUBSIDE AROUND SUNSET AND THEN A COLD FRONT WILL ARRIVE BETWEEN 07-08Z WITH THE WINDS SHIFTING TO THE NORTHWEST AND THEN NORTH. THERE IS FAIRLY GOOD CONSENSUS AMONG THE MODELS THAT LOW MVFR OR IFR CEILINGS WILL DROP IN BEHIND THE COLD FRONT...REACHING THE METROPLEX BETWEEN 10-12Z THURSDAY MORNING AND WILL PREVAIL BKN010. 82/JLD && .PREV DISCUSSION... /ISSUED 401 AM CST WED FEB 15 2012/ STRONG LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS NORTH TEXAS THIS MORNING AHEAD OF AN APPROACHING UPPER LOW AND ASSOCIATED DRY LINE/PRE-FRONTAL TROUGH. SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE MORNING WITH INCREASING LARGE SCALE FORCING. THE UPPER LOW IS PROGGED TO OPEN UP AND LIFT QUICKLY NORTHEAST THIS AFTERNOON AND ALLOW THE DRY LINE TO SURGE EASTWARD. A FEW STRONG/MARGINALLY SEVERE STORMS COULD DEVELOP ALONG THE DRY LINE ACROSS THE SOUTHEAST ZONES WHERE MOISTURE AND SHEAR WILL BE MOST FAVORABLE. ANY STORMS THAT DO FORM WILL BE FAST MOVERS AND SHOULD EXIT INTO EAST TEXAS BEFORE SUNSET. DOWNBURST WINDS AND HAIL WILL BE THE PRIMARY HAZARDS. WEST TO SOUTHWEST WINDS WILL INCREASE BETWEEN 15 AND 30 MPH BEHIND THE DRYLINE AND HUMIDITIES WILL FALL BELOW 30 PERCENT. THESE ELEVATED GRASS FIRE CONDITIONS WILL OCCUR THIS AFTERNOON... ESPECIALLY ALONG AND WEST OF A GRAHAM TO GOLDTHWAITE LINE. A COLD FRONT WILL MOVE ACROSS NORTH TEXAS TONIGHT AND BRING COOLER AND DRIER AIR THROUGH THURSDAY. ANOTHER UPPER TROUGH WILL DEVELOP IN THE SOUTHWEST U.S. ON FRIDAY AND RESULT IN INCREASING HIGH CLOUDINESS ACROSS TEXAS. HOWEVER...LOW LEVEL MOISTURE IS NOT EXPECTED TO SURGE NORTHWARD DUE TO A SURFACE LOW IN THE GULF. SCATTERED SHOWERS AND THUNDERSTORMS SHOULD DEVELOP ACROSS NORTH TEXAS FRIDAY NIGHT WITH THE BEST CHANCES IN THE SOUTHERN ZONES WHERE LOW LEVEL MOISTURE WILL BE MOST ABUNDANT. SHOWERS AND THUNDERSTORMS WILL END FROM NORTHWEST TO SOUTHEAST SATURDAY AS THE UPPER TROUGH AXIS AND ASSOCIATED COLD FRONT MOVES ACROSS THE REGION. A BRIEF COOL DOWN IS EXPECTED SUNDAY BEFORE LOW LEVEL WARM AIR ADVECTION INCREASES AHEAD OF YET ANOTHER DEVELOPING LOW PRESSURE SYSTEM IN THE WEST. MOST OF THE ENERGY ASSOCIATED WITH THIS SYSTEM WILL REMAIN TO THE NORTH OF TEXAS WITH SNOW EXPECTED ACROSS PORTIONS OF THE ROCKIES AND CENTRAL HIGH PLAINS. NORTH TEXAS MAY SEE A SLIGHT CHANCE OF SHOWERS MONDAY GENERALLY ALONG AND AHEAD OF ANOTHER COLD FRONT. SURFACE HIGH PRESSURE WILL SETTLE INTO THE REGION MONDAY NIGHT/TUESDAY WITH DRIER AND COOLER CONDITIONS EXPECTED. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 76 42 60 40 58 / 50 10 0 10 10 WACO, TX 75 39 59 40 58 / 50 10 0 10 10 PARIS, TX 69 42 60 36 61 / 60 10 0 10 10 DENTON, TX 76 38 61 34 57 / 50 10 0 10 10 MCKINNEY, TX 73 39 59 36 58 / 50 10 0 10 10 DALLAS, TX 76 46 58 41 60 / 50 10 0 10 10 TERRELL, TX 70 41 59 38 60 / 60 10 0 10 10 CORSICANA, TX 72 44 61 40 60 / 60 10 0 10 10 TEMPLE, TX 74 41 62 40 60 / 60 10 0 10 10 MINERAL WELLS, TX 75 37 58 34 56 / 40 10 0 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
532 AM CST WED FEB 15 2012 .AVIATION... CONCERNS... IFR AND LIFR CEILINGS THIS MORNING...CROSSWIND PROBLEMS AT THE METROPLEX TAF SITES THIS AFTERNOON...AND MVFR/IFR CEILINGS RETURNING THURSDAY MORNING. IFR CEILINGS ARE PREVAILING AT THE METROPLEX TAF SITES THIS MORNING WITH LIFR CIGS AND VISBY AT KACT. HOWEVER...SATELLITE IMAGERY SHOWS THE LOW ALREADY ERODING TO THE WEST OF THE METROPLEX AS DRY AIR AT 850 MB MOVES ACROSS THE REGION. BASED ON THE LATEST TRENDS AND GUIDANCE FROM THE RUC MODEL...IT APPEARS THE IFR CIGS WILL IMPROVE INTO VFR CONDITIONS BETWEEN 12-13Z AS THIS DRIER AIR AT 850 MB REACHES THE METROPLEX. AT KACT...EXPECT LIFR CONDITIONS TO PERSIST THROUGH 15Z AND IMPROVE TO MVFR FOR THE REMAINDER OF THE MORNING. LIGHT SHOWERS ARE INCREASING IN COVERAGE ACROSS THE REGION AND WILL CARRY VCSH AT ALL THE TAF SITES FOR MUCH OF THE MORNING. WHILE AN ISOLATED THUNDERSTORM CANNOT BE COMPLETELY RULED OUT THIS MORNING...THE THREAT IS TOO LOW TO CONTINUE THE CB MENTION IN THE TAF...EXCEPT FOR AT KACT FROM 16-18Z. A DRYLINE WILL REACH THE I-35 CORRIDOR AROUND 20Z WITH WEST WINDS OF 15G25KT OCCURRING AT THE METROPLEX TAF SITES BUT LESSER WINDS AROUND 12-14 KTS AT KACT. THE GUSTY WEST WINDS IN THE METROPLEX WILL CREATE SOME CROSSWIND PROBLEMS. THERE IS A SMALL CHANCE THAT A FEW ADDITIONAL THUNDERSTORMS MAY OCCUR ALONG THE DRYLINE AS IT REACHES THE TAF SITES THIS AFTERNOON BUT THE POTENTIAL IS LOW AT THIS TIME AND WILL NOT MENTION A CB GROUP IN THE TAF WITH THIS ISSUANCE. THE WIND SPEEDS WILL SUBSIDE AROUND SUNSET AND THEN A COLD FRONT WILL ARRIVE BETWEEN 07-08Z WITH THE WINDS SHIFTING TO THE NORTHWEST AND THEN NORTH. THERE IS FAIRLY GOOD CONSENSUS AMONG THE MODELS THAT LOW MVFR OR IFR CEILINGS WILL DROP IN BEHIND THE COLD FRONT...REACHING THE METROPLEX BETWEEN 10-12Z THURSDAY MORNING AND WILL PREVAIL BKN010. 82/JLD && .PREV DISCUSSION... /ISSUED 401 AM CST WED FEB 15 2012/ STRONG LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS NORTH TEXAS THIS MORNING AHEAD OF AN APPROACHING UPPER LOW AND ASSOCIATED DRY LINE/PRE-FRONTAL TROUGH. SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE MORNING WITH INCREASING LARGE SCALE FORCING. THE UPPER LOW IS PROGGED TO OPEN UP AND LIFT QUICKLY NORTHEAST THIS AFTERNOON AND ALLOW THE DRY LINE TO SURGE EASTWARD. A FEW STRONG/MARGINALLY SEVERE STORMS COULD DEVELOP ALONG THE DRY LINE ACROSS THE SOUTHEAST ZONES WHERE MOISTURE AND SHEAR WILL BE MOST FAVORABLE. ANY STORMS THAT DO FORM WILL BE FAST MOVERS AND SHOULD EXIT INTO EAST TEXAS BEFORE SUNSET. DOWNBURST WINDS AND HAIL WILL BE THE PRIMARY HAZARDS. WEST TO SOUTHWEST WINDS WILL INCREASE BETWEEN 15 AND 30 MPH BEHIND THE DRYLINE AND HUMIDITIES WILL FALL BELOW 30 PERCENT. THESE ELEVATED GRASS FIRE CONDITIONS WILL OCCUR THIS AFTERNOON... ESPECIALLY ALONG AND WEST OF A GRAHAM TO GOLDTHWAITE LINE. A COLD FRONT WILL MOVE ACROSS NORTH TEXAS TONIGHT AND BRING COOLER AND DRIER AIR THROUGH THURSDAY. ANOTHER UPPER TROUGH WILL DEVELOP IN THE SOUTHWEST U.S. ON FRIDAY AND RESULT IN INCREASING HIGH CLOUDINESS ACROSS TEXAS. HOWEVER...LOW LEVEL MOISTURE IS NOT EXPECTED TO SURGE NORTHWARD DUE TO A SURFACE LOW IN THE GULF. SCATTERED SHOWERS AND THUNDERSTORMS SHOULD DEVELOP ACROSS NORTH TEXAS FRIDAY NIGHT WITH THE BEST CHANCES IN THE SOUTHERN ZONES WHERE LOW LEVEL MOISTURE WILL BE MOST ABUNDANT. SHOWERS AND THUNDERSTORMS WILL END FROM NORTHWEST TO SOUTHEAST SATURDAY AS THE UPPER TROUGH AXIS AND ASSOCIATED COLD FRONT MOVES ACROSS THE REGION. A BRIEF COOL DOWN IS EXPECTED SUNDAY BEFORE LOW LEVEL WARM AIR ADVECTION INCREASES AHEAD OF YET ANOTHER DEVELOPING LOW PRESSURE SYSTEM IN THE WEST. MOST OF THE ENERGY ASSOCIATED WITH THIS SYSTEM WILL REMAIN TO THE NORTH OF TEXAS WITH SNOW EXPECTED ACROSS PORTIONS OF THE ROCKIES AND CENTRAL HIGH PLAINS. NORTH TEXAS MAY SEE A SLIGHT CHANCE OF SHOWERS MONDAY GENERALLY ALONG AND AHEAD OF ANOTHER COLD FRONT. SURFACE HIGH PRESSURE WILL SETTLE INTO THE REGION MONDAY NIGHT/TUESDAY WITH DRIER AND COOLER CONDITIONS EXPECTED. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 76 42 60 40 58 / 50 10 0 10 10 WACO, TX 75 39 59 40 58 / 50 10 0 10 10 PARIS, TX 69 42 60 36 61 / 60 10 0 10 10 DENTON, TX 76 38 61 34 57 / 50 10 0 10 10 MCKINNEY, TX 74 39 59 36 58 / 50 10 0 10 10 DALLAS, TX 77 46 58 41 60 / 50 10 0 10 10 TERRELL, TX 72 41 59 38 60 / 60 10 0 10 10 CORSICANA, TX 73 44 61 40 60 / 60 10 0 10 10 TEMPLE, TX 74 41 62 40 60 / 60 10 0 10 10 MINERAL WELLS, TX 75 37 58 34 56 / 40 10 0 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/79
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1156 PM CST THU FEB 16 2012 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... LATEST WV IMAGERY WITH H500 RUC ANALYSIS SHOWED CONFLUENT UPPER LEVEL FLOW ACROSS THE MISSOURI RIVER VALLEY...WITH A WEAK SHORTWAVE APPROACHING THE MT/ND BORDER. SURFACE ANALYSIS DEPICTED 1025MB HIGH CENTERED OVER KS/MO BORDER...WITH A NORTH/SOUTH ORIENTED TROUGH LOCATED OVER THE CENTRAL DAKOTAS IN ASSOCIATION WITH THE AFOREMENTIONED SHORTWAVE. AS THE WEAK UPPER LEVEL WAVE MOVES SOUTHEAST ACROSS THE DAKOTAS OVERNIGHT...AND THE SURFACE HIGH MEANDERS EASTWARD...THE LOW LEVEL WINDS WILL GRADUALLY BACK FROM THE WEST TOWARD THE SOUTHWEST OVERNIGHT. THEY SHOULD REMAIN STRONG ENOUGH TO MITIGATE ANY WIDESPREAD DENSE FOG. HOWEVER...TIME HEIGHT CROSS SECTIONS SHOW SOME LOW LEVEL MOISTURE DEVELOPING BY MORNING...SO FEEL THAT PATCHY FOG IS POSSIBLE...ESPECIALLY ACROSS SNOW COVERED AREAS. FOR OVERNIGHT LOW TEMPS WENT WITH THE BIAS-CORRECTED GUIDANCE. .LONG TERM /FRIDAY THROUGH THURSDAY/... FORECAST CHALLENGE THROUGH THE PERIOD REMAINS THE UPPER LEVEL SYSTEM IMPACTING THE MIDWEST EARLY NEXT WEEK. BEFORE THEN...SHORT WAVE ENERGY DROPPING SOUTHEAST THROUGH ERN MONTANA/WRN NORTH DAKOTA WILL PUSH THROUGH FRIDAY MORNING. GOOD KINEMATICS AND A PUSH OF TEMPERATURE ADVECTION WILL ARRIVE WITH THE SYSTEM. THE SYSTEM WILL BE LACKING MOISTURE HOWEVER. THAT SAID...IT APPEARS TO BE A SMALL WINDOW WITH FLURRIES OR WORST CASE SCENARIO A LIGHT SNOW SHOWER TO MOVE THROUGH INTO MID MORNING. A SFC BOUNDARY WILL MOVE THROUGH DURING THE DAY ON FRIDAY AS WELL. IT WILL NOT REACH THE SOUTHEAST UNTIL THE AFTERNOON...THEREFORE A GOOD WARMUP AHEAD OF BOUNDARY IS POSSIBLE. THE COLD ADVECTION WILL BE FOCUSED NEAR 925 MB WITH THE SFC IMPACT LAGGING. WITH THIS...MIXING WILL OCCUR AND LIMIT THE SFC IMPACT ON TEMPERATURES DURING THE DAY. ANOTHER BOUNDARY WILL DROP SOUTH FRIDAY NIGHT AND WILL LEAD TO A COOLER YET DRY WEEKEND. STILL A COMPLEX SITUATION EARLY NEXT WEEK WITH AN ACTIVE FLOW AND NUMEROUS PIECES OF ENERGY MOVING THROUGH THE LONG WAVE TROUGH. THE FOCUS IS ON THREE OF THE EMBEDDED IMPULSES WITH ONE NORTH INTO CANADA...ONE IMPACTING THE MIDWEST AND ANOTHER DROPPING WELL TO THE SOUTH. EACH COULD CERTAINLY IMPACT THE OTHERS REGARDING TIMING AND PLACEMENT BUT AT THIS TIME...SOME CONSENSUS DEVELOPING REGARDING EACH. FOCUS FOR PRECIPITATION WILL BE LATE MONDAY THROUGH EARLY TUESDAY. TRENDS ARE SUGGESTING THE PRECIPITATION COULD BE MOSTLY SNOW OVER THE NORTH WITH A MIX OR EVEN ALL RAIN TO THE SOUTH. THE FLOW WILL REMAIN ACTIVE FOR THE REMAINDER OF THE EXTENDED WITH ADDITIONAL POTENTIAL FOR PRECIPITATION AND TEMPERATURES GENERALLY NEAR TO ABOVE SEASONAL VALUES. && .AVIATION...17/06Z VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE TAF PERIOD. HAD LOW CONFIDENCE WITH MENTION OF FOG DEVELOPING OVERNIGHT TONIGHT AND TOOK MENTION OUT ATTM. WINDS WILL SHIFT TO THE SOUTHWEST FOR A SHORT WHILE BEFORE THE WEAK COOL FRONT/TROUGH PUSHES THROUGH EARLY FRIDAY MORNING. MIXING DEVELOPS BY AROUND MIDDAY AND SHOULD SEE A FEW GUSTS NEAR 20KTS FRIDAY AFTERNOON. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BEITLICH LONG TERM...DONAVON AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS CARIBOU ME
422 AM EST FRI FEB 17 2012 .SYNOPSIS... AN OCCLUDED FRONT WILL CROSS THE REGION TODAY. HIGH PRESSURE WILL THEN SLOWLY BUILD EAST SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... THE CHALLENGE WILL BE SNOWFALL AND TEMPERATURES. SHORT RANGE MODEL GUIDANCE IS RUNNING TOO COLD ATTM PER THE LATEST OBS BY AT LEAST 2-4 DEGREES. THE GFS AND RUC MATCHED WELL W/THE 00Z UA SHOWING WARMER AIR MAKING ITS WAY FURTHER NORTH INTO NE AROOSTOOK COUNTY THIS AFTERNOON. RADAR WAS SHOWING LIGHT PRECIP IN THE FORM OF RAIN MOVING ACROSS THE INTERIOR SECTIONS OF DOWNEAST MAINE WHILE LIGHT SNOW IS BREAKING OUT ACROSS THE CENTRAL REGIONS. THAT WARMER AIR WILL CONTINUE TO STREAM NE LATER THIS MORNING W/SNOW MIXING W/& CHANGING OVER TO RAIN OVER THE CENTRAL AREAS AND THEN THE MIX OR EVEN CHANGEOVER TO RAIN ACROSS THE NORTHERN AREAS BY AROUND 18Z. ACROSS THE SAINT JOHN VALLEY, TEMPERATURES WILL BE RIGHT AROUND THE CRITICAL TEMPERATURES OF 32-33F W/PRECIP MAINLY IN THE FORM OF SNOW. QPF WILL BE LESS THAN .25" FOR THIS EVENT W/THE HIGHEST TOTAL OVER THE EASTERN CORRIDOR OF MAINE & MAINLY IN THE FORM OF RAIN. SNOW RATIOS ACROSS THE NORTH WILL BE IN A RANGE OF 10-11:1 AND THEN DROP BACK TO LESS THAN 10:1 BY LATE MORNING AS THE LLVLS WARM. THIS WILL CUT DOWN ON ACCUMULATIONS. STAYED W/SNOWFALL AMOUNTS OF 1-2 INCHES AND THIS WILL MAINLY BE NORTH AND WEST OF CARIBOU AND PRESQUE ISLE. THERE COULD BE A PERIOD OF MODERATE TO HEAVY SNOWFALL AS SOME MID LEVEL INSTABILITY IS SHOWN BY THE GFS TO TAKE PLACE FROM 12-18Z. HIGH TEMPERATURES TODAY WILL BE IN THE LOW TO MID 30S ACROSS THE NORTH W/UPPER 30S TO LOWER 40S ACROSS DOWNEAST AND THE COAST. FOR TONIGHT, OCCLUSION IS FCST TO SLIDE INTO NEW BRUNSWICK THIS EVENING W/STEADY PRECIP ENDING AND COOLER AIR FILTERING INTO THE REGION. AIRMASS STARTS TO DRY OUT TONIGHT MAINLY ACROSS THE CENTRAL AND DOWNEAST REGION W/SOME CLEARING. FURTHER NORTH, BRIEF CLEARING WILL GIVE WAY TO CLOUDS AS UPPER TROF MOVES ACROSS THE REGION. SOME WEAK FORCING IS THERE IN THE MID LEVELS TO TRIGGER SOME LIGHT SNOW/SNOW SHOWERS. STAYED W/20-30% POPS AND LEANED CLOSE TO THE PREVIOUS LOWS OF UPPER TEENS/LOWER 20S ACROSS THE NORTH AND WEST TO LOW TO MID 20S FOR THE CENTRAL AND DOWNEAST REGION. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... INTENSIFYING LOW PRESSURE WILL LIFT THROUGH THE CANADIAN MARITIMES ON SATURDAY WITH GUSTY WEST WINDS EXPECTED. OUTSIDE OF ANY SCATTERED SNOW SHOWERS OR FLURRIES ACROSS NORTHWEST AREAS EXPECT PARTLY SUNNY SKIES ACROSS THE NORTH AND MOSTLY SUNNY SKIES DOWNEAST. A FAST MOVING SHORT WAVE FROM THE EASTERN GREAT LAKES WILL MOVE ACROSS NEW ENGLAND LATER SATURDAY AND SATURDAY NIGHT. ANY SNOW SHOWERS WITH THIS SYSTEM WILL REMAIN TO OUR SOUTH WITH MAINLY CLEAR TO PARTLY CLOUDY SKIES EXPECTED ACROSS THE REGION. HIGH PRESSURE WILL BUILD TOWARD THE REGION ON SUNDAY WITH PARTLY TO MOSTLY SUNNY SKIES EXPECTED. HIGHS ON SATURDAY WILL RANGE THE UPR 20S TO LWR 30S NORTH AND MID TO UPR 30S DOWNEAST. LOWS SATURDAY NIGHT WILL FALL INTO THE SINGLE DIGITS ABOVE ZERO NORTH AND LOW TO MID TEENS DOWNEAST. HIGHS ON SUNDAY WILL RANGE FROM THE MID TO UPR 20S NORTH AND LOW TO MID 30S DOWNEAST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... QUIET WEATHER PATTERN WILL CONTINUE FOR MUCH OF THE UPCOMING WEEK. LOW PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST SUNDAY EVENING AND PASS WELL TO THE SOUTH OF THE GULF OF MAINE SUNDAY NIGHT. MONDAY WILL BE A COLD AND BLUSTERY DAY AS HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. HIGH PRESSURE WILL CONTINUE TO BUILD EAST ACROSS THE REGION ON TUESDAY...THEN MOVE EAST TUESDAY NIGHT. LOW PRESSURE WILL APPROACH FROM THE WEST TUESDAY NIGHT AND TRACK THROUGH QUEBEC PROVINCE ON WEDNESDAY. EXPECT INCREASING CLOUDS LATER TUESDAY NIGHT WITH THE CHANCE FOR SNOW SHOWERS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY BUILD ACROSS THE REGION WEDNESDAY NIGHT BEFORE ANOTHER WEAK DISTURBANCE BRINGS ANOTHER CHANCE FOR SNOW SHOWERS ON THURSDAY. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... NEAR TERM: MVFR FOR KBGR/KBHB WILL GO TO IFR W/RAIN. ACROSS THE NORTHERN TERMINALS, VFR WILL GO TO MVFR THIS MORNING AND THEN QUICKLY TO IFR W/RASN. CONDITIONS WILL IMPROVE TO VFR FOR KBGR AND KBHB AFT 00Z W/SOME CLEARING. THE NORTHERN TERMINALS WILL SEE IFR GO MVFR LATE IN THE AFTERNOON AND THEN VFR LATER AT NIGHT. SHORT TERM: MVFR CIGS ARE POSSIBLE ACROSS THE NORTHERN TERMINALS SATURDAY...OTHERWISE MAINLY VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. && .MARINE... NEAR TERM: DECIDED TO GO W/A SCA STARTING LATER TONIGHT THROUGH SATURDAY PER COORD W/GYX. THIS WILL MAINLY BE FOR WIND GUSTS OF 25 KT AND FOR THE OUTER ZONES AS THE INTRACOASTAL WATERS SHOULD STAY BELOW SCA THRESHOLDS. KEPT SEAS IN THE RANGE OF 2-4 FT W/ WAVE HEIGHTS GETTING CLOSE TO 5 FT. SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED SATURDAY AND INTO SATURDAY NIGHT. ANOTHER ROUND OF SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE SUNDAY NIGHT AND MONDAY AS INTENSIFYING LOW PRESSURE MOVES WELL SOUTH OF NOVA SCOTIA. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 4 PM EST SATURDAY FOR ANZ050-051. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 AM EST FRI FEB 17 2012 .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 437 AM EST FRI FEB 17 2012 WV SATELLITE AND RUC ANALYSIS SHOWING UPPER TROUGH CURRENTLY OVER THE NCNTRL CONUS...WITH A COUPLE SHORTWAVES EMBEDDED WITHIN THE FLOW. SHORTWAVE IN WRN MN IS AIDING A WEAK SFC LOW THAT HAS DEVELOPED ALONG A SFC TROUGH EXTENDING FROM A MUCH STRONGER LOW LOCATED OVER WRN ONTARIO. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES AROUND -8.5C OVER THE ERN LK...WHICH HAS DIMINISHED MUCH OF THE LES DURING THE OVERNIGHT HOURS. FARTHER TO THE W...THERE ARE A FEW SNOW SHOWERS THAT HAVE DEVELOPED OVER THE NW CWA UNDER BROAD/WEAK H925-700 WAA. FINALLY...MORE NUMEROUS -SHSN ARE SEEN W OF A LINE FROM KELO TO KDLH ASSOCIATED WITH STRONGER H850-700 WAA/FGEN AND DEEPER MOISTURE. TODAY...THE SHORTWAVE WILL TRACK ESE THROUGH THE DAY AND KEEP THE MAIN WEAK LOW TRACKING TO THE S OF THE CWA AND THROUGH CNTRL WI. ON A BROAD SCALE...BEST H850-700 Q-VECTOR CONV...WAA...AND MOISTURE IS FOCUSED/TRACKS TO THE S OF THE CWA...FOLLOWING THE SHORTWAVE AND SFC LOW. BUT A RIBBON OF DEEPER MOISTURE JUST WNW OF KDLH AND PRODUCING THE SHOWERS WILL BE THE FIRST TO INFLUENCE THE AREA TODAY. H800-750 FGEN LINES UP WELL THE THE ONGOING -SHSN AND SHOULD START TO SLIDE INTO THE WRN CWA BETWEEN 12-15Z AND THEN INTO THE CNTRL BETWEEN 15-18Z. BUT AS IT MOVES E...THE FGEN/WAA BEGINS TO FOCUS FARTHER S/W CLOSER TO THE SFC LOW AND SHORTWAVE. THE NEXT WAVE OF H900-800 FGEN/WAA LOOKS TO PUSH OVER THE AREA HEADING INTO THE AFTN AND BRING THE BETTER CHANCE OF MORE WIDESPREAD LIGHT/MOD SNOW. 00Z NAM IS MORE PRONOUNCED ON THIS FGEN THAN THE 18Z GFS...BUT THE 00Z GFS HAS FOLLOWED SUIT AND LEADS TO HIGHER CONFIDENCE. IN ADDITION...00Z NAM/GFS BOTH SHOWING FAIRLY STRONG H850 OMEGA OVER THE SRN HALF OF THE CWA IN THE AFTN. ALL OF THIS COMBINED MADE ME FEEL CONFIDENT ON BUMPING POPS UP FROM THE GOING LOW CHANCES TO HIGH END CHANCES AND POCKETS OF LIKELY VALUES. SNOW AMNTS ARE TRICKY AS HEAVIEST ACCUMS WILL OCCUR WHERE THE BEST FGEN OCCURS AND IT APPEARS TO BE A FAIRLY NARROW CORRIDOR. SNOW RATIOS SHOULD START OUT IN THE 15/16-1 RANGE INITIALLY WITH THE HIGHER FORCING CLOSER TO THE DGZ...BUT DROP TO AROUND 13-1 DURING THE MAIN SNOW THIS AFTN...DUE TO BEST FGEN FORCING LOCATED BELOW THE DGZ AND WITH LLVL TEMPS ARE SLIGHTLY ABOVE FREEZING. WETBULB ZERO VALUES STAY BELOW 700FT SO EXPECT PCPN TO STAY AS ALL SNOW OVER THE SCNTRL CWA. OVERALL...EXPECT AREAS S OF A TWIN LAKES...TO GWINN...TO ESCANABA TO SEE A DUSTING TO AN INCH OF SNOW. BUT COULD BE SOME LOCALIZED 1.5-2IN AMOUNTS WHERE THE W-E ALIGNED BAND SETS UP. LATEST 06Z NAM RUN HAS SHIFTED THIS HEAVIER BAND SLIGHTLY FARTHER S...FROM KIMT THROUGH MENOMINEE COUNTY...SO SNOW AMNTS MAY NEED TO BE TWEAKED BASED OFF TRENDS THIS MORNING WITH LATEST RUNS. ALSO...THERE ARE SOME HINTS OF WEAK UPSLOPE/LK ENHANCED PCPN AIDING AMNTS OVER THE HIGHER TERRAIN OF MARQUETTE COUNTY...BUT WITH LIMITED COLD AIR CURRENTLY IN PLACE OVER THE LK...NOT TO CONFIDENT ON IT HELPING TOTALS TOO MUCH. TONIGHT...SHOULD SEE DIMINISHING TREND FROM W TO E DURING THE LATE AFTN AND INTO THE EVENING AS THE FGEN/MOISTURE SLIDES E AHEAD OF THE NEXT SHORTWAVE. STRONGER SHORTWAVE WILL BE DIVING S ACROSS THE UPPER GREAT LKS REGION LATE THIS EVENING AND OVERNIGHT. FOLLOWED 00Z GFS/NAM SOLN AS PREFERRED BY HPC THAT IS SLIGHTLY SLOWER AND DIVES THE WAVE ACROSS WRN/CNTRL UPPER MI. EVEN THOUGH THE SHORTWAVE LOOKS TO BE FAIRLY POTENT...MOISTURE LOOKS TO BE OF CONCERN AS MUCH OF THE DEEPER MOISTURE PULLS OUT OF THE AREA WITH THE FIRST WAVE. THIS LEAVES LIMITED CONFIDENCE IN SYNOPTIC PCPN OCCURRING. ATTENTION THEN TURNS TO LES POTENTIAL. H850 TEMPS FALLING FROM AROUND -10C AT 00Z SAT TO AROUND -14 TO -15C BY 12Z SAT WILL INCREASE THE LK INDUCED INSTABILITY. WITH LIMITED INSTABILITY/MOISTURE TO START THE EVENING...HAVE TRIMMED BACK POPS OVER THE NW U.P. SHORELINES AT THE START OF THE PERIOD. WITH THE COLDER TEMPS ARRIVING AND SHORTWAVE ENERGY PUSHING THROUGH LATE THIS EVENING AND OVERNIGHT...EXPECT LES CHANCES TO INCREASE THROUGH THE NIGHT. WINDS ARE STILL A LITTLE TRICKY SINCE HIGH RES RUNS ARE STILL HINTING AT SOME LK INDUCED TROUGHING...BUT EXPECT THE BEST CHANCES OVER THE N TO NNW WIND FAVORED LOCATIONS. WITH INVERSION HEIGHTS AROUND 5-6KFT THERE COULD BE SOME STRONGER BANDS...BUT SOME LIMITING FACTORS EXIST. FIRST...ALTHOUGH TEMPS ARE COOLING...MODELS SHOWING MUCH OF THE OMEGA OCCURRING BELOW THE DGZ...WHICH SHOULD KEEP SNOW RATIOS ON THE LOW SIDE. ONE EXCEPTION WOULD BE OVER THE KEWEENAW...WHERE THE COLDEST TEMPS ARE AND SHOULD PLACE FORCING MORE IN THE DGZ. SECOND...WITH THE SHORTWAVE MOVING THROUGH...MODELS ARE SHOWING SOME DIRECTIONAL SHEAR BETWEEN THE SFC AND H850. THUS...KEPT LES AMNTS UNDER AN INCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 437 AM EST FRI FEB 17 2012 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE GREAT LAKES REGION INTO THE NORTHERN PLAINS WITH A CLOSED LOW OVER THE GULF OF CA AND A RIDGE IS OFF THE WEST COAST. THE TROUGH OVER THE GREAT LAKES REGION WILL GET AMPLIFIED AS A SHORTWAVE DIGS SOUTHEAST INTO THE AREA TONIGHT WITH A SHORTWAVE RIDGE BUILDING INTO THE AREA SAT NIGHT INTO SUNDAY. LAKE EFFECT WILL CONTINUE TO BE GOING ON SATURDAY MORNING BEFORE THE ENVIRONMENT GETS A BIT MORE HOSTILE TO LAKE EFFECT. GFS BUFKIT SOUNDINGS SHOW AN INVERTED-V SOUNDING IN THE LOW LEVELS AT IWD...CMX AND ERY AND INVERSION HEIGHTS FALL IN THE MORNING FROM 3000-4000 FEET. DGZ ALSO FALLS IN HEIGHT AND DEEPER MOISTURE DEPARTS AS DRY AIR COMES IN. OMEGA IN THE DGZ ALSO BECOMES NEGATIVE WITH DOWNWARD MOTION AT THAT TIME SO THE LIKELY POPS IN THE MORNING IN NORTH AFFECT LAKE SUPERIOR LAKE EFFECT SNOW BELTS WILL DECREASE TO CHANCE IN THE AFTERNOON AS THE WINDS BACK MORE TOWARDS THE WEST. WINDS GO WEST TO SOUTHWEST SAT NIGHT SO ANY LINGERING LAKE EFFECT IN THE NORTH WILL PUSH OFFSHORE AND IN THE EAST WILL CONTINUE TO DIMINISH. WITH THE LIGHT SW WINDS ON LAND...TEMPERATURES WILL GET COLD AS IDEAL RADIATIONAL COOLING SETS UP WITH CLEAR SKIES AND LIGHT WINDS. WENT COLDER WITH TEMPERATURES THAN THE GOING FORECAST AND WENT WITH ADJMAV GUIDANCE WHICH LOOKED REASONABLE. SUNDAY AND SUNDAY NIGHT LOOK DRY AND THIS CARRIES INTO MONDAY AS WELL. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO LOWER LOW TEMPERATURES FOR SATURDAY NIGHT. IN THE EXTENDED...ECMWF SHOWS A 500 MB TROUGH THAT WILL MOVE INTO THE PLAINS ON MONDAY WITH SPLIT FLOW COMBINING TO FORM A DEEP TROUGH MOVING INTO THE UPPER GREAT LAKES LATE TUE THAT PUSHES THROUGH WITH MORE ENERGY DIGGING INTO THE GREAT LAKES WED NIGHT INTO THU. TEMPERATURES LOOK TO STAY MILD THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL. SYSTEM SNOW FOR MON NIGHT AND TUE. THERE IS A HINT OF SOME LAKE EFFECT FOR THE REST OF THE PERIOD WITH THE GFS SHOWING SOME COLDER AIR COMING IN. THE ECMWF DOES NOT HAVE THE COLDER AIR COMING IN SO NO LAKE EFFECT. AVERAGING THIS OUT WOULD GIVE SLIGHT CHANCE POPS AND THAT IS WHAT WILL BE FORECASTED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1231 AM EST FRI FEB 17 2012 DURING THE OVERNIGHT...VFR CONDITIONS SHOULD GENERALLY PREVAIL AT KIWD/KCMX/KSAW AS SOMEWHAT DRIER AIR AT THE LOW-LEVELS MOVES ACROSS THE AREA. ATTENTION THEN TURNS TO A FAIRLY WELL-DEFINED SHORTWAVE AND ASSOCIATED SMALL LOW PRES CENTER MOVING INTO NW MN. AS THIS SYSTEM TRACKS EASTWARD...IT`S LOOKING MORE FAVORABLE FOR A RELATIVELY SMALL AREA OF -SN TO DEVELOP INTO WRN UPPER MI IN THE MORNING AND SPREAD E DURING THE DAY. AS A RESULT...EXPECT CONDITIONS AT KIWD TO FALL TO MVFR WITH THE ONSET OF PCPN...AND THERE MAY BE PERIODS OF IFR IN THE EARLY AFTN. KSAW WILL BE ON THE NRN EDGE OF SYSTEM...SO ONLY LOWERED CONDITIONS TO MVFR THERE IN THE MID/LATE AFTN INTO EARLY EVENING. WITH SYSTEM LIKELY PASSING S OF KCMX... ONLY EXPECT SOME FLURRIES AT TIMES OFF THE LAKE ALONG WITH THE DEVELOPMENT OF MVFR CIGS. BETTER CHANCE OF -SHSN WILL DEVELOP AT KCMX DURING THE EVENING AS OVERLAKE INSTABILITY INCREASES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 437 AM EST FRI FEB 17 2012 NO GALES ARE EXPECTED THROUGH THE PERIOD. THE STRONGEST WINDS THROUGH MID WEEK NEXT WEEK WILL OCCUR THIS MORNING AS NORTHWEST WINDS GUST TO AROUND 30 KTS ON THE PERIPHERY OF A LOW MOVING ACROSS ONTARIO. WITH WARMER TEMPERATURES AND LIGHTER WINDS...FREEZING SPRAY SHOULD NOT BE A PROBLEM EITHER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...07 AVIATION...ROLFSON MARINE...07
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 AM CST FRI FEB 17 2012 .SHORT TERM... 305 AM CST FRI FEB 17 2012 MAIN FORECAST CONCERN IS ON PRECIPITATION CHANCES TODAY. 07Z WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH OVER NORTH DAKOTA. AT THE SURFACE...A WEAK COLD FRONT WAS SITUATED FROM NORTHERN MINNESOTA...BACK INTO EASTERN SOUTH DAKOTA. BAND OF MAINLY MID LEVEL CLOUDS WERE SEEN AHEAD OF IT ACROSS MINNESOTA. 17.00Z MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. SHORTWAVE OVER NORTH DAKOTA WILL ROTATE SOUTHEAST AND ACROSS THE FORECAST AREA TODAY...AS SURFACE COLD FRONT AND WEAK SURFACE LOW PUSHES THROUGH THE AREA. BOTH THE GFS AND NAM SHOWING A SWATH OF QG CONVERGENCE BETWEEN 850MB-500MB ALONG WITH SOME 285K-295K ISENTROPIC LIFT. IN ADDITION...850MB-700MB LAPSE RATES RATHER STEEP 7-9 DEGREES CELSIUS PER KILOMETER BY THIS AFTERNOON. RUC ALSO SHOWING UPWARDS OF 200 J/KG OF 0-3KM MOST UNSTABLE CAPE OVER THE NORTHEASTERN PORTION OF THE FORECAST AREA. THE BIGGEST QUESTION WILL BE DEGREE OF SATURATION. 17.06Z RUC BUFKIT SOUNDINGS SHOWS BEST SATURATION TO THE NORTH OF INTERSTATE 94...WITH AREAS SOUTH OF THERE SATURATION OCCURS ABOVE 900MB. DID RAISE PROBABILITIES A LITTLE ACROSS THE NORTHEAST. WITH MILD PACIFIC AIRMASS IN PLACE AND SURFACE TEMPERATURES EXPECTED INTO THE MIDDLE 30S TO THE LOWER 40S DID MENTION BOTH RAIN AND SNOW SHOWERS. SHORTWAVE EXITS EAST OF THE AREA TONIGHT WITH ONLY SOME LINGERING PRECIPITATION EARLY IN THE EVENING ACROSS THE EASTERN COUNTIES. OTHERWISE...BOTH THE NAM AND GFS INDICATE SOME STRATUS BEHIND THE FONT TO SETTLE OVER THE AREA...MAINLY ACROSS THE NORTHEAST SECTIONS OF THE FORECAST AREA. THESE CLOUDS WILL MOVE OUT RATHER QUICKLY ON SATURDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA. THIS SURFACE HIGH WILL REMAIN OVERHEAD THROUGH SUNDAY WITH CLEAR SKIES...LIGHT WINDS AND SEASONABLE TEMPERATURES. .LONG TERM... 305 AM CST FRI FEB 17 2012 BOTH THE 17.00Z GFS AND ECMWF SHOWING A MORE ACTIVE WEATHER PATTERN DURING THIS TIME FRAME. LONGWAVE TROUGH PUSHES OUT OF THE CENTRAL CONUS MONDAY AND ACROSS THE AREA MONDAY NIGHT INTO TUESDAY. GFS IS SHOWING A MORE NORTH/SOUTH SPLIT OF THE ENERGY VERSUS THE ECMWF...ALTHOUGH THE ECMWF TO A LESSER EXTENT IS ALSO SHOWING THIS TREND. THUS...SURFACE LOW LOOKS TO BE SOMEWHAT WEAKER. GULF WILL BE OPEN AHEAD OF THE SYSTEM WHICH WILL ALLOW FOR A GOOD FETCH OF MOISTURE AHEAD OF IT. WITH PACIFIC AIRMASS REMAINING IN PLACE QUESTION WILL BE PRECIPITATION TYPES...WITH A LIKELY SCENARIO OF MAINLY SNOW MONDAY NIGHT AND RAIN/SNOW TUESDAY. ANOTHER WAVE DROPS THROUGH THE AREA WEDNESDAY THROUGH THURSDAY AND KEPT PRECIPITATION CHANCES IN THE FORECAST WITH RAIN/SNOW MIX. ALL IN ALL...TEMPERATURES LOOK TO REMAIN MILD AND ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...THROUGH 06Z SATURDAY 1131 PM CST THU FEB 16 2012 SURFACE HIGH PRESSURE RIDGE AXIS IS PASSING OVER THE AREA LATE THIS EVENING AND A WEAK AREA OF LOW PRESSURE WAS NEAR KFAR. A BAND OF MID LEVEL CLOUDS WITH VFR CEILINGS WAS ADVANCING SOUTHEAST AHEAD OF THE SURFACE LOW AND IS EXPECTED TO SPREAD ACROSS BOTH TAF SITES BEFORE 12Z. THE SURFACE LOW IS EXPECTED TO TRACK ACROSS CENTRAL MINNESOTA AND WISCONSIN THROUGH TONIGHT AND FRIDAY AS A SHORT WAVE TROUGH ALOFT MOVES ACROSS THE UPPER MIDWEST. THE BEST FORCING FROM THE SHORT WAVE TROUGH IS EXPECTED TO OCCUR DURING THE LATE MORNING HOURS WITH THE 17.00Z NAM BEING THE STRONGEST AND BRINGS IN A SHORT PERIOD OF MVFR CEILINGS A BOTH TAF SITES. THE 17.03Z RUC ALSO SHOWS THESE CEILINGS DEVELOPING WHILE THE 17.00Z GFS DOES NOT AND THE PROBABILITIES FOR MVFR CEILINGS FROM THE 16.21Z SREF IS ONLY AROUND 20. THIS SIGNAL HAS BEEN CONSISTENT IN THE NAM SO HAVE INTRODUCED A SHORT PERIOD OF SOME TEMPORARY MVFR CEILINGS FOR BOTH SITES LATE FRIDAY MORNING. ONCE THE WEAK LOW GOES BY...THE WINDS WILL SWING AROUND TO THE NORTHWEST WITH ALL GUIDANCE SHOWING THE CLOUDS SCATTERING OUT. && .ARX WATCHES/WARNINGS/ADVISORIES... 305 AM CST FRI FEB 17 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RABERDING LONG TERM...RABERDING AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1132 PM CST THU FEB 16 2012 .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT 239 PM CST THU FEB 16 2012 MAIN FORECAST CONCERNS THIS PACKAGE...SMALL SPRINKLE/FLURRY CHANCE ON FRI...CLOUDS/TEMPERAURES THRU THE PERIOD. DATA ANALYSIS AT 18Z HAD A BROAD AREA OF HIGH PRESSURE OVER MUCH OF THE CENTRAL CONUS...CENTERED OVER KS/OK. A WEAK LOW WAS LOCATED NORTH OF LK SUPERIOR...PRODUCING WEST TO NORTHWEST GRADIENT FLOW AND WEAK LOW LEVEL COLD ADVECTION ACROSS MUCH OF MN/IA/WI AT MID DAY. A SHORTWAVE WAS MOVING ACROSS NORTHERN WI. BUT FOR A PATCH OF MID CLOUDS MOVING ACROSS CENTRAL WI...CLOUDS AND ANY PRECIP WITH THE SHORTWAVE CONFINED TO FAR NORTHERN MN/WI. ELSEWHERE SUNNY SKIES AND MINIMAL SNOW COVER OVER MUCH OF MN/IA/WI ALLOWING NOON-TIME TEMPS TO AGAIN WARM INTO THE 30S TO LOW 40S OVER MUCH OF THE REGION. 16.12Z MODELS LOOK TO HAVE INITIALIZED WELL AND OFFER QUITE SIMILAR SOLUTIONS FOR TONIGHT INTO SUN NIGHT. BIGGEST DIFFERENCE OF SIGNIFICANCE LOOKS TO BE 925-850MB MOISTURE/SATURATION AND IMPACTS ON ANY PRECIP CHANCE FRI. DPROG/DT OF 500MB HGTS AT 16.12Z SHOWED MODEL RUNS OF 14.12Z AND 15.12Z VERIFIED QUITE WELL ACROSS NOAM WITH A TIGHT CONSENSUS TRENDED TOWARD A COMPROMISE OF THE EARLIER RUNS ON ALL FEATURES. TREND FOR TONIGHT/FRI IS TOWARD THE MORE PROGRESSIVE OF EARLIER RUNS WITH THE SHORTWAVE TROUGH DROPPING INTO THE UPPER MIDWEST. THIS FASTER TREND FAVORED FRI NIGHT/SAT AS THE TROUGH SHIFTS EAST OF THE AREA AND HGTS RISE ACROSS THE NORTHERN PLAINS. BETTER CONSISTENCY DEVELOPING SAT THRU SUN NIGHT WITH THE NEXT TROUGH INTO THE WESTERN CONUS SAT THEN INTO THE ROCKIES/WESTERN PLAINS SUN/SUN NIGHT...AND CONTINUED RISING HGTS/RIDGING ALOFT OVER THE UPPER MIDWEST. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED ALL MODELS QUITE GOOD WITH THE SFC MASS FIELDS OVER CENTRAL NOAM. PER WV IMAGERY...ALL MODELS LOOKED QUITE GOOD WITH THE SHORTWAVE DETAILS ACROSS NOAM. WITH NO PREFERRED DETERMINISTIC MODEL AT 18Z AND THE TREND TOWARD A TIGHTER COMMON SOLUTION...FAVORED THE MODEL/ ENSEMBLE CONSENSUS THIS CYCLE. SHORT-TERM FCST CONFIDENCE GOOD... THOUGH THE SHORT-TERM REMAINS RATHER QUIET FOR THE AREA. FOR THE SHORT TERM...BUT FOR FRI THE SHORT TERM IS GENERALLY DOMINATED BY HIGH PRESSURE AND MODIFIED PACIFIC AIRMASSES. MID/HIGH CLOUDS INCREASE TONIGHT AHEAD OF THE SHORTWAVE APPROACHING ACROSS ND/MN...WITH LOWER CLOUDS/MOISTURE SWEEPING ACROSS MUCH OF THE AREA BEHIND THE DEPARTING SFC-850MB TROUGH FRI NIGHT. RIDGING ALOFT...SFC HIGH PRESSURE...LOW LEVEL ANTICYCLONIC FLOW/SUBSIDENCE/DIVERGENCE SPREAD ACROSS THE AREA FOR SAT THRU SUN NIGHT. GENERALLY CLEAR TO PARTLY CLOUDY SKIES AND LIGHT WINDS EXPECTED SAT THRU SUN NIGHT UNDER THE INFLUENCE OF THE HIGH/RIDGING ALOFT. LOW LEVEL COLD ADVECTION SPREADS ACROSS THE AREA IN THE WAKE OF THE TROUGH FRI NIGHT...WITH 925MB TEMPS FOR SAT IN THE -6C TO -10C RANGE AND HIGHS SAT CLOSER TO NORMAL FOR MID FEB. WITH LIGHT WINDS UNDER THE SFC- 850MB RIDGE AXIS SAT NIGHT INTO SUN NIGHT...AIRMASS ONLY SLOWLY MODIFIES/WARMS. WITH PLENTY OF SUNSHINE BY SUN AND MINIMAL SNOW COVER...HIGHS SUN SHOULD BE AT LEAST A FEW DEGREES WARMER THAN THOSE OF SAT. BACK TO FRI/FRI EVENING...MODEL CONSENSUS CONTINUES TO INDICATE MAIN MOISTURE WITH THE APPROACHING/PASSING SHORTWAVE WILL BE ABOVE ABOUT 800MB. BULK OF LOWER LEVEL CONVERGENCE/LIFT AHEAD OF THE SFC-700MB TROUGH AND DIVERGENCE ALOFT AHEAD OF THE MID LEVEL SHORTWAVE STILL APPEAR TO GO INTO TRYING TO SATURATE THE COLUMN ENOUGH TO ALLOW ANY PRECIP TO REACH THE GROUND. PER MODEL SOUNDINGS AND X-SECTIONS...BY THE TIME SOME 925-800MB SATURATION OCCURS THE STRONGER/DEEPER OF THE LIFT IS PASSING EAST OF THE FCST AREA LATE FRI AFTERNOON/ EVENING. GIVEN THE INITIAL DRY AIRMASS OVER THE AREA AND MINIMAL CLOUDS OVER ND WITH/AHEAD OF THE SHORTWAVE THIS AFTERNOON...REDUCED PRECIP MENTION FRI/FRI EVENING TO SPRINKLES/FLURRIES WITH A SMALL CHANCE OF MEASURABLE PRECIPITATION. MOISTURE CENTERED NEAR 925MB ROTATES SOUTHEAST ACROSS THE AREA BEHIND THE TROUGH FRI NIGHT BUT THIS QUITE SHALLOW UNDER A DEVELOPING INVERSION NEAR 900MB. WITH THE PROGRESSIVENESS OF THE SFC-MID LEVEL TROUGH AND RIDGING BUILDING IN THIS MOISTURE/STRATUS EXPECTED TO PUSH EAST OF THE FCST AREA BY OR DURING SAT MORNING. NUMERICAL TEMP GUIDANCE FOR TONIGHT THRU SUN NIGHT QUITE SIMILAR AND LOOK TO BE IN THE BALLPARK. WITH PLENTY OF SUNSHINE EXPECTED SAT/SUN AND MINIMAL/BROKEN SNOW COVER...TRENDED HIGHS BOTH DAYS TOWARD THE WARMER OF GUIDANCE HIGHS. .LONG TERM...MONDAY THROUGH THURSDAY 239 PM CST THU FEB 16 2012 16.00Z MEDIUM RANGE MODEL RUNS CONTINUE THE TREND OF THE 15.12Z RUNS OF A MORE NORTH/SOUTH STREAM SPLIT OF THE ENERGY IN THE TROUGH MOVING ACROSS THE CENTRAL CONUS MON/TUE. NORTHERN STREAM PORTION OF THE TROUGH REMAINS MORE PROGRESSIVE...WITH A POSITIVE TILT TO THE TROUGH AS IT MOVES ACROSS THE UPPER MIDWEST TUE. BETTER BETWEEN MODEL CONSISTENCY WED FOR A NORTHERN STREAM SHORTWAVE TO CARVE OUT A LONG-WAVE TROUGH OVER THE NORTH-CENTRAL CONUS. MODELS THEN DIFFER ON THE PROGRESSIVENESS OF THIS TROUGH BY THU...GFS FASTER...ECMWF SLOWER. THE TRENDS MON/TUE LEAD TO LESSER RUN-TO-RUN CONSISTENCY AND LOWER FCST CONFIDENCE. GFS/ECMWF DO OFFER DECENT RUN-TO-RUN CONSISTENCY WITH THEIR OWN PREVIOUS RUNS WED/THU. THE 16.12Z GFS/ ECMWF RUNS CONTINUE TO SUPPORT THIS. WITH ALL THE SPREAD IN THE DETAILS...LESSER BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY...LIKE PMDEPD A MODEL/ENSEMBLE BLEND FAVORED IN THE DAY 4-7 PERIOD. LONG- TERM FCST CONFIDENCE AVERAGE AT BEST. PATTERN DOES LOOK TO BE MORE ACTIVE/UNSETTLED NEXT WEEK WITH AREA TO BE IMPACTED BY 2 STRONGER TROUGHS. FIRST TROUGH MOVES INTO THE CENTRAL/NORTHERN PLAINS MON WITH SHORTWAVE RIDGING ALOFT AND MILD HIGH PRESSURE SLOWLY SHIFTING EAST OF THE AREA. THE SFC THRU MID LEVEL TROUGH WITH AN INCREASE OF MOISTURE AND FORCING/LIFT MOVES INTO/ACROSS THE UPPER MIDWEST MON NIGHT/TUE. SOME TIMING/SPEED DIFFERENCES AMONG THE MODELS BY DAYS 4/5 BUT MAINLY -SN CHANCES IN THE 25-45 PERCENT RANGE REASONABLE FOR NOW. PLENTY OF DETAIL DIFFERENCES BY WED/THU...BUT ANOTHER INCREASE OF MOISTURE/LIFT WITH FALLING HGTS AS THE NEXT NORTHERN STREAM SHORTWAVE CARVES OUT A DEEPER TROUGH ACROSS THE UPPER MIDWEST. PRECIP CHANCES IN THE 15-30 PERCENT RANGE FOR WED/THU REASONABLE UNTIL MODELS CONVERGE ON A TIGHTER CONSENSUS SOLUTION. LOWER LEVELS ABOVE 0C WED...WITH COLUMN COOLING THRU WED NIGHT/THU AS HGTS FALL. PRECIP WOULD BE -RA OR -RA/-SN WED...TRANSITIONING TO MAINLY -SN FOR WED NIGHT/THU. WITH UNCERTAINTIES ON CLOUDS/PRECIP...A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR MON-THU REASONABLE FOR NOW. && .AVIATION...THROUGH 06Z SATURDAY 1131 PM CST THU FEB 16 2012 SURFACE HIGH PRESSURE RIDGE AXIS IS PASSING OVER THE AREA LATE THIS EVENING AND A WEAK AREA OF LOW PRESSURE WAS NEAR KFAR. A BAND OF MID LEVEL CLOUDS WITH VFR CEILINGS WAS ADVANCING SOUTHEAST AHEAD OF THE SURFACE LOW AND IS EXPECTED TO SPREAD ACROSS BOTH TAF SITES BEFORE 12Z. THE SURFACE LOW IS EXPECTED TO TRACK ACROSS CENTRAL MINNESOTA AND WISCONSIN THROUGH TONIGHT AND FRIDAY AS A SHORT WAVE TROUGH ALOFT MOVES ACROSS THE UPPER MIDWEST. THE BEST FORCING FROM THE SHORT WAVE TROUGH IS EXPECTED TO OCCUR DURING THE LATE MORNING HOURS WITH THE 17.00Z NAM BEING THE STRONGEST AND BRINGS IN A SHORT PERIOD OF MVFR CEILINGS A BOTH TAF SITES. THE 17.03Z RUC ALSO SHOWS THESE CEILINGS DEVELOPING WHILE THE 17.00Z GFS DOES NOT AND THE PROBABILITIES FOR MVFR CEILINGS FROM THE 16.21Z SREF IS ONLY AROUND 20. THIS SIGNAL HAS BEEN CONSISTENT IN THE NAM SO HAVE INTRODUCED A SHORT PERIOD OF SOME TEMPORARY MVFR CEILINGS FOR BOTH SITES LATE FRIDAY MORNING. ONCE THE WEAK LOW GOES BY...THE WINDS WILL SWING AROUND TO THE NORTHWEST WITH ALL GUIDANCE SHOWING THE CLOUDS SCATTERING OUT. && .ARX WATCHES/WARNINGS/ADVISORIES... 239 PM CST THU FEB 16 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION...04
AREA FORECAST DISCUSSION
NWS CARIBOU ME
600 AM EST FRI FEB 17 2012 .SYNOPSIS... AN OCCLUDED FRONT WILL CROSS THE REGION TODAY INTO TONIGHT. HIGH PRESSURE WILL THEN SLOWLY BUILD EAST SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...ADJUSTED THE TIMING OF PRECIP TO ACCOUNT MORE FOR THE LATEST RADAR TRENDS WHICH SHOW PRECIP MOVING FASTER TO THE NE THAN EARLIER EXPECTED. ALSO INCREASED PERCENTAGES UP TO NEAR 100% WHERE PRECIP IS OCCURRING. HRLY TEMPS WERE ADJUSTED AND ALSO RAISED THE MAXES FOR TODAY UP A FEW DEGREES EVEN AS FAR NORTH AS THE SAINT JOHN VALLEY. .PREVIOUS DISCUSSION... THE CHALLENGE WILL BE SNOWFALL AND TEMPERATURES. SHORT RANGE MODEL GUIDANCE IS RUNNING TOO COLD ATTM PER THE LATEST OBS BY AT LEAST 2-4 DEGREES. THE GFS AND RUC MATCHED WELL W/THE 00Z UA SHOWING WARMER AIR MAKING ITS WAY FURTHER NORTH INTO NE AROOSTOOK COUNTY THIS AFTERNOON. RADAR WAS SHOWING LIGHT PRECIP IN THE FORM OF RAIN MOVING ACROSS THE INTERIOR SECTIONS OF DOWNEAST MAINE WHILE LIGHT SNOW IS BREAKING OUT ACROSS THE CENTRAL REGIONS. THAT WARMER AIR WILL CONTINUE TO STREAM NE LATER THIS MORNING W/SNOW MIXING W/& CHANGING OVER TO RAIN OVER THE CENTRAL AREAS AND THEN THE MIX OR EVEN CHANGEOVER TO RAIN ACROSS THE NORTHERN AREAS BY AROUND 18Z. ACROSS THE SAINT JOHN VALLEY, TEMPERATURES WILL BE RIGHT AROUND THE CRITICAL TEMPERATURES OF 32-33F W/PRECIP MAINLY IN THE FORM OF SNOW. QPF WILL BE LESS THAN .25" FOR THIS EVENT W/THE HIGHEST TOTAL OVER THE EASTERN CORRIDOR OF MAINE & MAINLY IN THE FORM OF RAIN. SNOW RATIOS ACROSS THE NORTH WILL BE IN A RANGE OF 10-11:1 AND THEN DROP BACK TO LESS THAN 10:1 BY LATE MORNING AS THE LLVLS WARM. THIS WILL CUT DOWN ON ACCUMULATIONS. STAYED W/SNOWFALL AMOUNTS OF 1-2 INCHES AND THIS WILL MAINLY BE NORTH AND WEST OF CARIBOU AND PRESQUE ISLE. THERE COULD BE A PERIOD OF MODERATE TO HEAVY SNOWFALL AS SOME MID LEVEL INSTABILITY IS SHOWN BY THE GFS TO TAKE PLACE FROM 12-18Z. HIGH TEMPERATURES TODAY WILL BE IN THE LOW TO MID 30S ACROSS THE NORTH W/UPPER 30S TO LOWER 40S ACROSS DOWNEAST AND THE COAST. FOR TONIGHT, OCCLUSION IS FCST TO SLIDE INTO NEW BRUNSWICK THIS EVENING W/STEADY PRECIP ENDING AND COOLER AIR FILTERING INTO THE REGION. AIRMASS STARTS TO DRY OUT TONIGHT MAINLY ACROSS THE CENTRAL AND DOWNEAST REGION W/SOME CLEARING. FURTHER NORTH, BRIEF CLEARING WILL GIVE WAY TO CLOUDS AS UPPER TROF MOVES ACROSS THE REGION. SOME WEAK FORCING IS THERE IN THE MID LEVELS TO TRIGGER SOME LIGHT SNOW/SNOW SHOWERS. STAYED W/20-30% POPS AND LEANED CLOSE TO THE PREVIOUS LOWS OF UPPER TEENS/LOWER 20S ACROSS THE NORTH AND WEST TO LOW TO MID 20S FOR THE CENTRAL AND DOWNEAST REGION. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... INTENSIFYING LOW PRESSURE WILL LIFT THROUGH THE CANADIAN MARITIMES ON SATURDAY WITH GUSTY WEST WINDS EXPECTED. OUTSIDE OF ANY SCATTERED SNOW SHOWERS OR FLURRIES ACROSS NORTHWEST AREAS EXPECT PARTLY SUNNY SKIES ACROSS THE NORTH AND MOSTLY SUNNY SKIES DOWNEAST. A FAST MOVING SHORT WAVE FROM THE EASTERN GREAT LAKES WILL MOVE ACROSS NEW ENGLAND LATER SATURDAY AND SATURDAY NIGHT. ANY SNOW SHOWERS WITH THIS SYSTEM WILL REMAIN TO OUR SOUTH WITH MAINLY CLEAR TO PARTLY CLOUDY SKIES EXPECTED ACROSS THE REGION. HIGH PRESSURE WILL BUILD TOWARD THE REGION ON SUNDAY WITH PARTLY TO MOSTLY SUNNY SKIES EXPECTED. HIGHS ON SATURDAY WILL RANGE THE UPR 20S TO LWR 30S NORTH AND MID TO UPR 30S DOWNEAST. LOWS SATURDAY NIGHT WILL FALL INTO THE SINGLE DIGITS ABOVE ZERO NORTH AND LOW TO MID TEENS DOWNEAST. HIGHS ON SUNDAY WILL RANGE FROM THE MID TO UPR 20S NORTH AND LOW TO MID 30S DOWNEAST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... QUIET WEATHER PATTERN WILL CONTINUE FOR MUCH OF THE UPCOMING WEEK. LOW PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST SUNDAY EVENING AND PASS WELL TO THE SOUTH OF THE GULF OF MAINE SUNDAY NIGHT. MONDAY WILL BE A COLD AND BLUSTERY DAY AS HIGH PRESSURE SLOWLY BUILDS IN FROM THE WEST. HIGH PRESSURE WILL CONTINUE TO BUILD EAST ACROSS THE REGION ON TUESDAY...THEN MOVE EAST TUESDAY NIGHT. LOW PRESSURE WILL APPROACH FROM THE WEST TUESDAY NIGHT AND TRACK THROUGH QUEBEC PROVINCE ON WEDNESDAY. EXPECT INCREASING CLOUDS LATER TUESDAY NIGHT WITH THE CHANCE FOR SNOW SHOWERS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY BUILD ACROSS THE REGION WEDNESDAY NIGHT BEFORE ANOTHER WEAK DISTURBANCE BRINGS ANOTHER CHANCE FOR SNOW SHOWERS ON THURSDAY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... NEAR TERM: MVFR FOR KBGR/KBHB WILL GO TO IFR W/RAIN. ACROSS THE NORTHERN TERMINALS, VFR WILL GO TO MVFR THIS MORNING AND THEN QUICKLY TO IFR W/RASN. CONDITIONS WILL IMPROVE TO VFR FOR KBGR AND KBHB AFT 00Z W/SOME CLEARING. THE NORTHERN TERMINALS WILL SEE IFR GO MVFR LATE IN THE AFTERNOON AND THEN VFR LATER AT NIGHT. SHORT TERM: MVFR CIGS ARE POSSIBLE ACROSS THE NORTHERN TERMINALS SATURDAY...OTHERWISE MAINLY VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. && .MARINE... NEAR TERM: DECIDED TO GO W/A SCA STARTING LATER TONIGHT THROUGH SATURDAY PER COORD W/GYX. THIS WILL MAINLY BE FOR WIND GUSTS OF 25 KT AND FOR THE OUTER ZONES AS THE INTRACOASTAL WATERS SHOULD STAY BELOW SCA THRESHOLDS. KEPT SEAS IN THE RANGE OF 2-4 FT W/ WAVE HEIGHTS GETTING CLOSE TO 5 FT. SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED SATURDAY AND INTO SATURDAY NIGHT. ANOTHER ROUND OF SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE SUNDAY NIGHT AND MONDAY AS INTENSIFYING LOW PRESSURE MOVES WELL SOUTH OF NOVA SCOTIA. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 4 PM EST SATURDAY FOR ANZ050-051. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
944 AM EST FRI FEB 17 2012 .UPDATE... ISSUED AT 943 AM EST FRI FEB 17 2012 SFC TROUGH IS SETTLING ACROSS KEWEENAW ATTM AND THAT IS HELPING TO ENHANCE THE SNOW FM THE KEWEENAW ACROSS SOUTH CENTRAL LAKE SUPERIOR. INCREASED POPS THROUGH MORNING TO ACCOUNT FOR THIS. SNOW AMOUNTS SHOULD REMAIN LESS THAN AN INCH. TWEAKED POPS FOR AFTN OVR CNTRL TO BRING IN HIGHER POPS INTO NCNTRL UPR MI. TROUGH SINKING SOUTH SHOULD ENHANCE LOW-LEVEL CONVERGENCE. MEANWHILE...LARGER SCALE UVM/LGT SNOW TIED TO H8-H7 FRONTOGENESIS SHOULD CONTINUE TO SPREAD FM WESTERN LK SUPERIOR ACROSS MUCH OF THE WEST HALF OF CWA. WOULD EXPECT THE SNOW TO BECOME ENHANCED OVR CNTRL CWA AS THIS FORCING IS SUPPLEMENTED BY THE LOWER LEVEL CONVERGENCE. IF ALL THIS COMES TOGETHER AS LATEST NAM/LOCAL WRF SHOWS...THEN MAY SEE AT LEAST LOCALIZED SNOW AMOUNTS OVER AN INCH OVER PORTIONS OF WEST HALF OF CWA. KIND OF A WETTER SNOW WITH SLR/S IN THE 10-15:1 RANGE. TEMPS/WINDS ON TRACK AND ONLY MINOR CHANGES WERE MADE. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 437 AM EST FRI FEB 17 2012 WV SATELLITE AND RUC ANALYSIS SHOWING UPPER TROUGH CURRENTLY OVER THE NCNTRL CONUS...WITH A COUPLE SHORTWAVES EMBEDDED WITHIN THE FLOW. SHORTWAVE IN WRN MN IS AIDING A WEAK SFC LOW THAT HAS DEVELOPED ALONG A SFC TROUGH EXTENDING FROM A MUCH STRONGER LOW LOCATED OVER WRN ONTARIO. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES AROUND -8.5C OVER THE ERN LK...WHICH HAS DIMINISHED MUCH OF THE LES DURING THE OVERNIGHT HOURS. FARTHER TO THE W...THERE ARE A FEW SNOW SHOWERS THAT HAVE DEVELOPED OVER THE NW CWA UNDER BROAD/WEAK H925-700 WAA. FINALLY...MORE NUMEROUS -SHSN ARE SEEN W OF A LINE FROM KELO TO KDLH ASSOCIATED WITH STRONGER H850-700 WAA/FGEN AND DEEPER MOISTURE. TODAY...THE SHORTWAVE WILL TRACK ESE THROUGH THE DAY AND KEEP THE MAIN WEAK LOW TRACKING TO THE S OF THE CWA AND THROUGH CNTRL WI. ON A BROAD SCALE...BEST H850-700 Q-VECTOR CONV...WAA...AND MOISTURE IS FOCUSED/TRACKS TO THE S OF THE CWA...FOLLOWING THE SHORTWAVE AND SFC LOW. BUT A RIBBON OF DEEPER MOISTURE JUST WNW OF KDLH AND PRODUCING THE SHOWERS WILL BE THE FIRST TO INFLUENCE THE AREA TODAY. H800-750 FGEN LINES UP WELL THE THE ONGOING -SHSN AND SHOULD START TO SLIDE INTO THE WRN CWA BETWEEN 12-15Z AND THEN INTO THE CNTRL BETWEEN 15-18Z. BUT AS IT MOVES E...THE FGEN/WAA BEGINS TO FOCUS FARTHER S/W CLOSER TO THE SFC LOW AND SHORTWAVE. THE NEXT WAVE OF H900-800 FGEN/WAA LOOKS TO PUSH OVER THE AREA HEADING INTO THE AFTN AND BRING THE BETTER CHANCE OF MORE WIDESPREAD LIGHT/MOD SNOW. 00Z NAM IS MORE PRONOUNCED ON THIS FGEN THAN THE 18Z GFS...BUT THE 00Z GFS HAS FOLLOWED SUIT AND LEADS TO HIGHER CONFIDENCE. IN ADDITION...00Z NAM/GFS BOTH SHOWING FAIRLY STRONG H850 OMEGA OVER THE SRN HALF OF THE CWA IN THE AFTN. ALL OF THIS COMBINED MADE ME FEEL CONFIDENT ON BUMPING POPS UP FROM THE GOING LOW CHANCES TO HIGH END CHANCES AND POCKETS OF LIKELY VALUES. SNOW AMNTS ARE TRICKY AS HEAVIEST ACCUMS WILL OCCUR WHERE THE BEST FGEN OCCURS AND IT APPEARS TO BE A FAIRLY NARROW CORRIDOR. SNOW RATIOS SHOULD START OUT IN THE 15/16-1 RANGE INITIALLY WITH THE HIGHER FORCING CLOSER TO THE DGZ...BUT DROP TO AROUND 13-1 DURING THE MAIN SNOW THIS AFTN...DUE TO BEST FGEN FORCING LOCATED BELOW THE DGZ AND WITH LLVL TEMPS ARE SLIGHTLY ABOVE FREEZING. WETBULB ZERO VALUES STAY BELOW 700FT SO EXPECT PCPN TO STAY AS ALL SNOW OVER THE SCNTRL CWA. OVERALL...EXPECT AREAS S OF A TWIN LAKES...TO GWINN...TO ESCANABA TO SEE A DUSTING TO AN INCH OF SNOW. BUT COULD BE SOME LOCALIZED 1.5-2IN AMOUNTS WHERE THE W-E ALIGNED BAND SETS UP. LATEST 06Z NAM RUN HAS SHIFTED THIS HEAVIER BAND SLIGHTLY FARTHER S...FROM KIMT THROUGH MENOMINEE COUNTY...SO SNOW AMNTS MAY NEED TO BE TWEAKED BASED OFF TRENDS THIS MORNING WITH LATEST RUNS. ALSO...THERE ARE SOME HINTS OF WEAK UPSLOPE/LK ENHANCED PCPN AIDING AMNTS OVER THE HIGHER TERRAIN OF MARQUETTE COUNTY...BUT WITH LIMITED COLD AIR CURRENTLY IN PLACE OVER THE LK...NOT TO CONFIDENT ON IT HELPING TOTALS TOO MUCH. TONIGHT...SHOULD SEE DIMINISHING TREND FROM W TO E DURING THE LATE AFTN AND INTO THE EVENING AS THE FGEN/MOISTURE SLIDES E AHEAD OF THE NEXT SHORTWAVE. STRONGER SHORTWAVE WILL BE DIVING S ACROSS THE UPPER GREAT LKS REGION LATE THIS EVENING AND OVERNIGHT. FOLLOWED 00Z GFS/NAM SOLN AS PREFERRED BY HPC THAT IS SLIGHTLY SLOWER AND DIVES THE WAVE ACROSS WRN/CNTRL UPPER MI. EVEN THOUGH THE SHORTWAVE LOOKS TO BE FAIRLY POTENT...MOISTURE LOOKS TO BE OF CONCERN AS MUCH OF THE DEEPER MOISTURE PULLS OUT OF THE AREA WITH THE FIRST WAVE. THIS LEAVES LIMITED CONFIDENCE IN SYNOPTIC PCPN OCCURRING. ATTENTION THEN TURNS TO LES POTENTIAL. H850 TEMPS FALLING FROM AROUND -10C AT 00Z SAT TO AROUND -14 TO -15C BY 12Z SAT WILL INCREASE THE LK INDUCED INSTABILITY. WITH LIMITED INSTABILITY/MOISTURE TO START THE EVENING...HAVE TRIMMED BACK POPS OVER THE NW U.P. SHORELINES AT THE START OF THE PERIOD. WITH THE COLDER TEMPS ARRIVING AND SHORTWAVE ENERGY PUSHING THROUGH LATE THIS EVENING AND OVERNIGHT...EXPECT LES CHANCES TO INCREASE THROUGH THE NIGHT. WINDS ARE STILL A LITTLE TRICKY SINCE HIGH RES RUNS ARE STILL HINTING AT SOME LK INDUCED TROUGHING...BUT EXPECT THE BEST CHANCES OVER THE N TO NNW WIND FAVORED LOCATIONS. WITH INVERSION HEIGHTS AROUND 5-6KFT THERE COULD BE SOME STRONGER BANDS...BUT SOME LIMITING FACTORS EXIST. FIRST...ALTHOUGH TEMPS ARE COOLING...MODELS SHOWING MUCH OF THE OMEGA OCCURRING BELOW THE DGZ...WHICH SHOULD KEEP SNOW RATIOS ON THE LOW SIDE. ONE EXCEPTION WOULD BE OVER THE KEWEENAW...WHERE THE COLDEST TEMPS ARE AND SHOULD PLACE FORCING MORE IN THE DGZ. SECOND...WITH THE SHORTWAVE MOVING THROUGH...MODELS ARE SHOWING SOME DIRECTIONAL SHEAR BETWEEN THE SFC AND H850. THUS...KEPT LES AMNTS UNDER AN INCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 437 AM EST FRI FEB 17 2012 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE GREAT LAKES REGION INTO THE NORTHERN PLAINS WITH A CLOSED LOW OVER THE GULF OF CA AND A RIDGE IS OFF THE WEST COAST. THE TROUGH OVER THE GREAT LAKES REGION WILL GET AMPLIFIED AS A SHORTWAVE DIGS SOUTHEAST INTO THE AREA TONIGHT WITH A SHORTWAVE RIDGE BUILDING INTO THE AREA SAT NIGHT INTO SUNDAY. LAKE EFFECT WILL CONTINUE TO BE GOING ON SATURDAY MORNING BEFORE THE ENVIRONMENT GETS A BIT MORE HOSTILE TO LAKE EFFECT. GFS BUFKIT SOUNDINGS SHOW AN INVERTED-V SOUNDING IN THE LOW LEVELS AT IWD...CMX AND ERY AND INVERSION HEIGHTS FALL IN THE MORNING FROM 3000-4000 FEET. DGZ ALSO FALLS IN HEIGHT AND DEEPER MOISTURE DEPARTS AS DRY AIR COMES IN. OMEGA IN THE DGZ ALSO BECOMES NEGATIVE WITH DOWNWARD MOTION AT THAT TIME SO THE LIKELY POPS IN THE MORNING IN NORTH AFFECT LAKE SUPERIOR LAKE EFFECT SNOW BELTS WILL DECREASE TO CHANCE IN THE AFTERNOON AS THE WINDS BACK MORE TOWARDS THE WEST. WINDS GO WEST TO SOUTHWEST SAT NIGHT SO ANY LINGERING LAKE EFFECT IN THE NORTH WILL PUSH OFFSHORE AND IN THE EAST WILL CONTINUE TO DIMINISH. WITH THE LIGHT SW WINDS ON LAND...TEMPERATURES WILL GET COLD AS IDEAL RADIATIONAL COOLING SETS UP WITH CLEAR SKIES AND LIGHT WINDS. WENT COLDER WITH TEMPERATURES THAN THE GOING FORECAST AND WENT WITH ADJMAV GUIDANCE WHICH LOOKED REASONABLE. SUNDAY AND SUNDAY NIGHT LOOK DRY AND THIS CARRIES INTO MONDAY AS WELL. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO LOWER LOW TEMPERATURES FOR SATURDAY NIGHT. IN THE EXTENDED...ECMWF SHOWS A 500 MB TROUGH THAT WILL MOVE INTO THE PLAINS ON MONDAY WITH SPLIT FLOW COMBINING TO FORM A DEEP TROUGH MOVING INTO THE UPPER GREAT LAKES LATE TUE THAT PUSHES THROUGH WITH MORE ENERGY DIGGING INTO THE GREAT LAKES WED NIGHT INTO THU. TEMPERATURES LOOK TO STAY MILD THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL. SYSTEM SNOW FOR MON NIGHT AND TUE. THERE IS A HINT OF SOME LAKE EFFECT FOR THE REST OF THE PERIOD WITH THE GFS SHOWING SOME COLDER AIR COMING IN. THE ECMWF DOES NOT HAVE THE COLDER AIR COMING IN SO NO LAKE EFFECT. AVERAGING THIS OUT WOULD GIVE SLIGHT CHANCE POPS AND THAT IS WHAT WILL BE FORECASTED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 629 AM EST FRI FEB 17 2012 A DISTURBANCE MOVING THROUGH WI TODAY WILL SPREAD SNOW ACROSS MAINLY THE SOUTHERN 2/3RDS OF UPPER MI TODAY. BEST SHOT FOR SNOW AND LOWER VSBYS WILL BE AT KIWD...BUT STILL SOME UNCERTAINTY ON IF THE HEAVIEST SNOW WILL BE S OF THE TAF SITE. KCMX WILL LIKELY BE AT MVFR CIGS THROUGH MUCH OF THE DAY AS THE FRONT SAGS SOUTH...WHILE KIWD/KSAW WILL HAVE TO WAIT UNTIL THE -SHSN START. TRIED TO SHOW A BREAK IN LOWER CIGS BEHIND THE DISTURBANCE AND DEVELOPING LES...BUT LIGHT UPSLOPE NORTHERLY FLOW COULD LEAD TO THE SCT CLOUDS BECOMING BKN. KIWD/KCMX WILL SEE LOWEST VSBYS AFTER MIDNIGHT...AS LAKE EFFECT SNOW DEVELOPS UNDER NNW FLOW. THIS LES COULD AFFECT KSAW LATE IN THE TAF PERIOD AND ONLY MADE SLIGHT VSBY REDUCTION DUE TO UNCERTAINTY OF A FAVORABLE WIND DIRECTION. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 437 AM EST FRI FEB 17 2012 NO GALES ARE EXPECTED THROUGH THE PERIOD. THE STRONGEST WINDS THROUGH MID WEEK NEXT WEEK WILL OCCUR THIS MORNING AS NORTHWEST WINDS GUST TO AROUND 30 KTS ON THE PERIPHERY OF A LOW MOVING ACROSS ONTARIO. WITH WARMER TEMPERATURES AND LIGHTER WINDS...FREEZING SPRAY SHOULD NOT BE A PROBLEM EITHER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...SRF LONG TERM...07 AVIATION...SRF MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
629 AM EST FRI FEB 17 2012 .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 437 AM EST FRI FEB 17 2012 WV SATELLITE AND RUC ANALYSIS SHOWING UPPER TROUGH CURRENTLY OVER THE NCNTRL CONUS...WITH A COUPLE SHORTWAVES EMBEDDED WITHIN THE FLOW. SHORTWAVE IN WRN MN IS AIDING A WEAK SFC LOW THAT HAS DEVELOPED ALONG A SFC TROUGH EXTENDING FROM A MUCH STRONGER LOW LOCATED OVER WRN ONTARIO. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES AROUND -8.5C OVER THE ERN LK...WHICH HAS DIMINISHED MUCH OF THE LES DURING THE OVERNIGHT HOURS. FARTHER TO THE W...THERE ARE A FEW SNOW SHOWERS THAT HAVE DEVELOPED OVER THE NW CWA UNDER BROAD/WEAK H925-700 WAA. FINALLY...MORE NUMEROUS -SHSN ARE SEEN W OF A LINE FROM KELO TO KDLH ASSOCIATED WITH STRONGER H850-700 WAA/FGEN AND DEEPER MOISTURE. TODAY...THE SHORTWAVE WILL TRACK ESE THROUGH THE DAY AND KEEP THE MAIN WEAK LOW TRACKING TO THE S OF THE CWA AND THROUGH CNTRL WI. ON A BROAD SCALE...BEST H850-700 Q-VECTOR CONV...WAA...AND MOISTURE IS FOCUSED/TRACKS TO THE S OF THE CWA...FOLLOWING THE SHORTWAVE AND SFC LOW. BUT A RIBBON OF DEEPER MOISTURE JUST WNW OF KDLH AND PRODUCING THE SHOWERS WILL BE THE FIRST TO INFLUENCE THE AREA TODAY. H800-750 FGEN LINES UP WELL THE THE ONGOING -SHSN AND SHOULD START TO SLIDE INTO THE WRN CWA BETWEEN 12-15Z AND THEN INTO THE CNTRL BETWEEN 15-18Z. BUT AS IT MOVES E...THE FGEN/WAA BEGINS TO FOCUS FARTHER S/W CLOSER TO THE SFC LOW AND SHORTWAVE. THE NEXT WAVE OF H900-800 FGEN/WAA LOOKS TO PUSH OVER THE AREA HEADING INTO THE AFTN AND BRING THE BETTER CHANCE OF MORE WIDESPREAD LIGHT/MOD SNOW. 00Z NAM IS MORE PRONOUNCED ON THIS FGEN THAN THE 18Z GFS...BUT THE 00Z GFS HAS FOLLOWED SUIT AND LEADS TO HIGHER CONFIDENCE. IN ADDITION...00Z NAM/GFS BOTH SHOWING FAIRLY STRONG H850 OMEGA OVER THE SRN HALF OF THE CWA IN THE AFTN. ALL OF THIS COMBINED MADE ME FEEL CONFIDENT ON BUMPING POPS UP FROM THE GOING LOW CHANCES TO HIGH END CHANCES AND POCKETS OF LIKELY VALUES. SNOW AMNTS ARE TRICKY AS HEAVIEST ACCUMS WILL OCCUR WHERE THE BEST FGEN OCCURS AND IT APPEARS TO BE A FAIRLY NARROW CORRIDOR. SNOW RATIOS SHOULD START OUT IN THE 15/16-1 RANGE INITIALLY WITH THE HIGHER FORCING CLOSER TO THE DGZ...BUT DROP TO AROUND 13-1 DURING THE MAIN SNOW THIS AFTN...DUE TO BEST FGEN FORCING LOCATED BELOW THE DGZ AND WITH LLVL TEMPS ARE SLIGHTLY ABOVE FREEZING. WETBULB ZERO VALUES STAY BELOW 700FT SO EXPECT PCPN TO STAY AS ALL SNOW OVER THE SCNTRL CWA. OVERALL...EXPECT AREAS S OF A TWIN LAKES...TO GWINN...TO ESCANABA TO SEE A DUSTING TO AN INCH OF SNOW. BUT COULD BE SOME LOCALIZED 1.5-2IN AMOUNTS WHERE THE W-E ALIGNED BAND SETS UP. LATEST 06Z NAM RUN HAS SHIFTED THIS HEAVIER BAND SLIGHTLY FARTHER S...FROM KIMT THROUGH MENOMINEE COUNTY...SO SNOW AMNTS MAY NEED TO BE TWEAKED BASED OFF TRENDS THIS MORNING WITH LATEST RUNS. ALSO...THERE ARE SOME HINTS OF WEAK UPSLOPE/LK ENHANCED PCPN AIDING AMNTS OVER THE HIGHER TERRAIN OF MARQUETTE COUNTY...BUT WITH LIMITED COLD AIR CURRENTLY IN PLACE OVER THE LK...NOT TO CONFIDENT ON IT HELPING TOTALS TOO MUCH. TONIGHT...SHOULD SEE DIMINISHING TREND FROM W TO E DURING THE LATE AFTN AND INTO THE EVENING AS THE FGEN/MOISTURE SLIDES E AHEAD OF THE NEXT SHORTWAVE. STRONGER SHORTWAVE WILL BE DIVING S ACROSS THE UPPER GREAT LKS REGION LATE THIS EVENING AND OVERNIGHT. FOLLOWED 00Z GFS/NAM SOLN AS PREFERRED BY HPC THAT IS SLIGHTLY SLOWER AND DIVES THE WAVE ACROSS WRN/CNTRL UPPER MI. EVEN THOUGH THE SHORTWAVE LOOKS TO BE FAIRLY POTENT...MOISTURE LOOKS TO BE OF CONCERN AS MUCH OF THE DEEPER MOISTURE PULLS OUT OF THE AREA WITH THE FIRST WAVE. THIS LEAVES LIMITED CONFIDENCE IN SYNOPTIC PCPN OCCURRING. ATTENTION THEN TURNS TO LES POTENTIAL. H850 TEMPS FALLING FROM AROUND -10C AT 00Z SAT TO AROUND -14 TO -15C BY 12Z SAT WILL INCREASE THE LK INDUCED INSTABILITY. WITH LIMITED INSTABILITY/MOISTURE TO START THE EVENING...HAVE TRIMMED BACK POPS OVER THE NW U.P. SHORELINES AT THE START OF THE PERIOD. WITH THE COLDER TEMPS ARRIVING AND SHORTWAVE ENERGY PUSHING THROUGH LATE THIS EVENING AND OVERNIGHT...EXPECT LES CHANCES TO INCREASE THROUGH THE NIGHT. WINDS ARE STILL A LITTLE TRICKY SINCE HIGH RES RUNS ARE STILL HINTING AT SOME LK INDUCED TROUGHING...BUT EXPECT THE BEST CHANCES OVER THE N TO NNW WIND FAVORED LOCATIONS. WITH INVERSION HEIGHTS AROUND 5-6KFT THERE COULD BE SOME STRONGER BANDS...BUT SOME LIMITING FACTORS EXIST. FIRST...ALTHOUGH TEMPS ARE COOLING...MODELS SHOWING MUCH OF THE OMEGA OCCURRING BELOW THE DGZ...WHICH SHOULD KEEP SNOW RATIOS ON THE LOW SIDE. ONE EXCEPTION WOULD BE OVER THE KEWEENAW...WHERE THE COLDEST TEMPS ARE AND SHOULD PLACE FORCING MORE IN THE DGZ. SECOND...WITH THE SHORTWAVE MOVING THROUGH...MODELS ARE SHOWING SOME DIRECTIONAL SHEAR BETWEEN THE SFC AND H850. THUS...KEPT LES AMNTS UNDER AN INCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 437 AM EST FRI FEB 17 2012 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE GREAT LAKES REGION INTO THE NORTHERN PLAINS WITH A CLOSED LOW OVER THE GULF OF CA AND A RIDGE IS OFF THE WEST COAST. THE TROUGH OVER THE GREAT LAKES REGION WILL GET AMPLIFIED AS A SHORTWAVE DIGS SOUTHEAST INTO THE AREA TONIGHT WITH A SHORTWAVE RIDGE BUILDING INTO THE AREA SAT NIGHT INTO SUNDAY. LAKE EFFECT WILL CONTINUE TO BE GOING ON SATURDAY MORNING BEFORE THE ENVIRONMENT GETS A BIT MORE HOSTILE TO LAKE EFFECT. GFS BUFKIT SOUNDINGS SHOW AN INVERTED-V SOUNDING IN THE LOW LEVELS AT IWD...CMX AND ERY AND INVERSION HEIGHTS FALL IN THE MORNING FROM 3000-4000 FEET. DGZ ALSO FALLS IN HEIGHT AND DEEPER MOISTURE DEPARTS AS DRY AIR COMES IN. OMEGA IN THE DGZ ALSO BECOMES NEGATIVE WITH DOWNWARD MOTION AT THAT TIME SO THE LIKELY POPS IN THE MORNING IN NORTH AFFECT LAKE SUPERIOR LAKE EFFECT SNOW BELTS WILL DECREASE TO CHANCE IN THE AFTERNOON AS THE WINDS BACK MORE TOWARDS THE WEST. WINDS GO WEST TO SOUTHWEST SAT NIGHT SO ANY LINGERING LAKE EFFECT IN THE NORTH WILL PUSH OFFSHORE AND IN THE EAST WILL CONTINUE TO DIMINISH. WITH THE LIGHT SW WINDS ON LAND...TEMPERATURES WILL GET COLD AS IDEAL RADIATIONAL COOLING SETS UP WITH CLEAR SKIES AND LIGHT WINDS. WENT COLDER WITH TEMPERATURES THAN THE GOING FORECAST AND WENT WITH ADJMAV GUIDANCE WHICH LOOKED REASONABLE. SUNDAY AND SUNDAY NIGHT LOOK DRY AND THIS CARRIES INTO MONDAY AS WELL. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO LOWER LOW TEMPERATURES FOR SATURDAY NIGHT. IN THE EXTENDED...ECMWF SHOWS A 500 MB TROUGH THAT WILL MOVE INTO THE PLAINS ON MONDAY WITH SPLIT FLOW COMBINING TO FORM A DEEP TROUGH MOVING INTO THE UPPER GREAT LAKES LATE TUE THAT PUSHES THROUGH WITH MORE ENERGY DIGGING INTO THE GREAT LAKES WED NIGHT INTO THU. TEMPERATURES LOOK TO STAY MILD THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL. SYSTEM SNOW FOR MON NIGHT AND TUE. THERE IS A HINT OF SOME LAKE EFFECT FOR THE REST OF THE PERIOD WITH THE GFS SHOWING SOME COLDER AIR COMING IN. THE ECMWF DOES NOT HAVE THE COLDER AIR COMING IN SO NO LAKE EFFECT. AVERAGING THIS OUT WOULD GIVE SLIGHT CHANCE POPS AND THAT IS WHAT WILL BE FORECASTED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 629 AM EST FRI FEB 17 2012 A DISTURBANCE MOVING THROUGH WI TODAY WILL SPREAD SNOW ACROSS MAINLY THE SOUTHERN 2/3RDS OF UPPER MI TODAY. BEST SHOT FOR SNOW AND LOWER VSBYS WILL BE AT KIWD...BUT STILL SOME UNCERTAINTY ON IF THE HEAVIEST SNOW WILL BE S OF THE TAF SITE. KCMX WILL LIKELY BE AT MVFR CIGS THROUGH MUCH OF THE DAY AS THE FRONT SAGS SOUTH...WHILE KIWD/KSAW WILL HAVE TO WAIT UNTIL THE -SHSN START. TRIED TO SHOW A BREAK IN LOWER CIGS BEHIND THE DISTURBANCE AND DEVELOPING LES...BUT LIGHT UPSLOPE NORTHERLY FLOW COULD LEAD TO THE SCT CLOUDS BECOMING BKN. KIWD/KCMX WILL SEE LOWEST VSBYS AFTER MIDNIGHT...AS LAKE EFFECT SNOW DEVELOPS UNDER NNW FLOW. THIS LES COULD AFFECT KSAW LATE IN THE TAF PERIOD AND ONLY MADE SLIGHT VSBY REDUCTION DUE TO UNCERTAINTY OF A FAVORABLE WIND DIRECTION. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 437 AM EST FRI FEB 17 2012 NO GALES ARE EXPECTED THROUGH THE PERIOD. THE STRONGEST WINDS THROUGH MID WEEK NEXT WEEK WILL OCCUR THIS MORNING AS NORTHWEST WINDS GUST TO AROUND 30 KTS ON THE PERIPHERY OF A LOW MOVING ACROSS ONTARIO. WITH WARMER TEMPERATURES AND LIGHTER WINDS...FREEZING SPRAY SHOULD NOT BE A PROBLEM EITHER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...07 AVIATION...SRF MARINE...07
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
735 AM CST FRI FEB 17 2012 .UPDATE... ADDED SLIGHT CHANCE OF SNOW SHOWERS BETWEEN 9 AM AND NOON CST TODAY ON THE CAPROCK MAINLY ALONG AND SOUTH OF I-40 INCLUDING AMARILLO... CANYON...HEREFORD...VEGA...PANHANDLE...CLAUDE...AND PAMPA. && .DISCUSSION... LIGHT PRECIPITATION...MAINLY IN THE FORM OF LIGHT RAIN...CONTINUES TO MOVE NORTHEAST AND INTO THE SOUTH TEXAS PANHANDLE THIS MORNING. MADE THE ADJUSTMENTS ABOVE AS LATEST KLBB RADAR INDICATED BRIGHT BANDING AS LOW AS 600 FT AGL JUST NORTHWEST OF LUBBOCK. APPEARS THIS HEAVIER ACTIVITY MAY COOL THE LOWEST 5000 FT OF THE ATMOSPHERE ENOUGH TO ALLOW FOR LIGHT SNOW TO MIX WITH THE LIGHT RAIN ACROSS THE SOUTH CENTRAL AND SOUTHWEST TEXAS PANHANDLES BETWEEN 9 AM AND NOON CST INCLUDING AMARILLO. WITH WARM SURFACE TEMPERATURES ABOVE FREEZING/32 DEGREES...IF ANY SNOW OCCURS...NO ACCUMULATIONS ARE EXPECTED. STILL BELIEVE LIGHT RAIN WILL BE THE PREDOMINANT PRECIPITATION TYPE THIS MORNING. SOME MID/UPPER DRY SLOTTING MOVING INTO THE PANHANDLES MAY LIMIT PRECIPITATION CHANCES THIS AFTERNOON. BY MIDDAY TODAY...SURFACE TEMPERATURES WILL LIKELY BE TOO WARM TO SUPPORT ANYTHING BUT LIGHT RAIN. PRODUCTS HAVE BEEN UPDATED. MBS && .PREV DISCUSSION... /ISSUED 557 AM CST FRI FEB 17 2012/ AVIATION... FOR THE 12Z TAFS...THERE IS QUITE A BIT OF UNCERTAINTY WITH RESPECT TO PRECIPITATION TIMING AND FLIGHT CATEGORIES. AT KAMA...EXPECT MVFR CONDITIONS 13-16Z AS -RA IMPACTS THE TAF SITE. AFTERWARD...VFR MAY PREDOMINANTLY PREVAIL THROUGH 23Z...BUT CONFIDENCE IS LOW. AFTER 23Z...HAVE MODERATE CONFIDENCE THAT MVFR CONDITIONS WILL DEVELOP...DETERIORATING TO IFR AFTER 03Z. AFTER 08Z...LIFR OR VLIFR CONDITIONS WILL BE POSSIBLE...BUT CONFIDENCE IN THIS IS CURRENTLY TOO LOW TO MENTION. AT KDHT...HAVE MODERATE CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL THROUGH 20Z WHEN MVFR CIGS DEVELOP. HAVE MODERATE TO HIGH CONFIDENCE THAT CIGS/VSBYS WILL DETERIORATE INTO IFR CATEGORY AFTER 03Z AND POSSIBLY LIFR/VLIFR AFTER 08Z. HOWEVER...CONFIDENCE IS LOW WHETHER LIFR/VLIFR CONDITIONS WILL DEVELOP. AT KGUY...HAVE MODERATE CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL THROUGH 21Z...BUT THERE IS A POSSIBILITY THAT MVFR CONDITIONS MAY DEVELOP AFTER 21Z. HAVE MODERATE CONFIDENCE THAT MVFR CONDITIONS WILL DEVELOP BY 03Z AND DETERIORATING TO IFR CONDITIONS AFTER 06Z. IT/S POSSIBLE THAT LIFR CONDITIONS COULD DEVELOP AFTER 06Z...BUT CONFIDENCE IN THIS IS LOW. -RA IS EXPECTED AT ALL TAF SITES THROUGH THIS PERIOD...BUT TIMING THE ONSET AND ENDING TIMES AT THIS POINT IS NEARLY IMPOSSIBLE. AMENDMENTS WILL BE NEEDED. IT/S POSSIBLE THERE COULD BE A -RASN MIX AT KDHT AFTER 09Z...BUT CONFIDENCE IS TOO LOW TO MENTION AT THIS TIME. A COLD FRONT WILL MOVE THROUGH ALL SITES 06-08Z WITH WINDS SHIFTING TO THE NORTH. JACKSON PREV DISCUSSION... /ISSUED 448 AM CST FRI FEB 17 2012/ DISCUSSION... PRECIPITATION CHANCES AND TYPES TODAY THROUGH SATURDAY MORNING ARE THE MAIN FORECAST CHALLENGES. LATEST MODELS WERE IN FAIR TO GOOD AGREEMENT. USED A BLEND WITH A PREFERENCE TOWARDS THE 00Z ECMWF DUE TO IT/S BETTER HANDLING OF MOISTURE AND QPF FIELDS. THE BIGGEST CHANGE TO THE PREVIOUS FORECAST WAS TO LOWER PRECIPITATION CHANCES TODAY ACROSS THE NORTH TEXAS AND OKLAHOMA PANHANDLES. AT 445 AM CST ACROSS THE PANHANDLES...MOSTLY CLOUDY CONDITIONS WERE OCCURRING WITH SURFACE TEMPERATURES MAINLY IN THE 30S. LIGHT RAIN SHOWERS WERE NEAR I-40 EAST OF AMARILLO AND AN AREA OF RAIN SHOWERS WERE JUST SOUTH OF A HEREFORD TO CLOVIS LINE. A MID/UPPER LOW WAS WELL SOUTH OF ARIZONA. THIS MORNING...KEPT THE HIGHEST RAIN CHANCES OVER THE SOUTH TEXAS PANHANDLE...GENERALLY 60 TO 90 PERCENT...THINKING CURRENT AREA OF RAIN SHOWERS MENTIONED ABOVE WILL HOLD TOGETHER. THE 00Z ECMWF DID BEST DEPICTING THIS AREA WITH ITS MOISTURE/QPF FIELDS. DOUBT MUCH...IF ANY RAINFALL...WILL OCCUR NORTH OF A CHANNING TO LIPSCOMB LINE. LATEST RUC13 AND WARM LOW LEVEL THERMAL FIELDS SUGGESTED THAT MOST...IF NOT ALL...OF THE PRECIPITATION WILL BE IN THE FORM OF LIGHT RAIN. RAINFALL AMOUNTS ARE EXPECTED TO RANGE FROM ZERO IN THE OKLAHOMA PANHANDLE UP TO 0.25 INCH SOUTH OF I-40. THERE IS A LITTLE CONCERN THAT THE PRECIPITATION COULD MIX WITH OR BRIEFLY TURN OVER TO LIGHT SNOW AND BRING A QUICK WET INCH OF SNOWFALL WEST OF I-27 AND SOUTH OF I-40 NEAR HEREFORD THIS MORNING...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE QUITE LOW...ESPECIALLY WITH CURRENT SURFACE WET BULB TEMPERATURES A FEW DEGREES ABOVE 32F. THIS AFTERNOON...KEPT RAIN CHANCES...20 TO 50 PERCENT ACROSS THE AREA. THERE MAY BE MORE DRY HOURS THAN WET ONES AND APPEARS ANY ADDITIONAL RAINFALL WILL GENERALLY BE LESS THAN 0.10 INCH. LOW LEVEL TEMPERATURES WILL BE WARM ENOUGH TO SUPPORT ALL RAIN. THE WARMER 00Z MAVMOS HIGHS IN THE 40S APPEARED REASONABLE. TONIGHT INTO SATURDAY MORNING...KEPT PRECIPITATION CHANCES 30 TO 50 PERCENT ACROSS THE AREA TONIGHT...THEN 20 TO 30 PERCENT SATURDAY MORNING. APPEARS ANY PRECIPITATION BEFORE MIDNIGHT WILL BE IN THE FORM OF LIGHT RAIN...THEN TURN OVER TO LIGHT SNOW NORTHWEST TO SOUTHEAST. AT THIS TIME...APPEARS ANY SNOWFALL ACCUMULATIONS WILL BE UNDER ONE HALF INCH. THERE IS A LOW CHANCE A BAND OF SNOW MAY DEVELOP NEAR A DALHART TO BEAVER LINE LATE TONIGHT INTO SATURDAY MORNING WHICH COULD BRING LOCALLY ENHANCE SNOWFALL AND BRING ONE TO TWO INCHES TO THESE AREAS...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE VERY LOW...ESPECIALLY AS NOT SURE PHASING WILL OCCUR WITH MID/UPPER TROUGHS MOVING OVER THE AREA. IN ADDITION...APPEARS THE BEST MOISTURE WILL BE CUT OFF AND OVER SOUTH TEXAS. WENT CLOSER TO THE WARMER 00Z MAVMOS LOWS. SATURDAY AFTERNOON THROUGH SUNDAY NIGHT...DRY CONDITIONS ARE EXPECTED. CLOUDS WILL BE SLOW TO CLEAR SATURDAY AFTERNOON...SO LOWERED HIGHS CLOSER TO THE COLDER 00Z MAVMOS NUMBERS. THERE IS A LOW CHANCE FOR LIGHT FREEZING FOG SUNDAY MORNING...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. BREEZY AND WARMER CONDITIONS WILL RETURN SUNDAY AFTERNOON UNDER MOSTLY SUNNY SKIES. MONDAY INTO MONDAY NIGHT...WINDY CONDITIONS SEEM LIKELY...ESPECIALLY MONDAY AFTERNOON. MAY BE CLOSE TO ADVISORY LEVEL OF 35 MPH SUSTAINED FOR 3 OR MORE HOURS. KEPT A DRY FORECAST FOR NOW AS APPEARS THE BEST MOISTURE AND LIFT WILL STAY NORTH AND EAST OF THE AREA. WENT NEAR OR ABOVE THE WARMER 00Z MEXMOS HIGHS. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA LATE AFTERNOON AND NIGHT. TUESDAY THROUGH THURSDAY...DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. LATEST MODELS WERE IN SOME DISAGREEMENT WITH SURFACE FEATURES. STAYED CLOSE TO THE 00Z MEXMOS TEMPERATURES. MBS FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH THIS WEEKEND. ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE MONDAY AFTERNOON ACROSS MUCH OF THE TEXAS PANHANDLE DUE WINDY CONDITIONS AND LOW HUMIDITY. THERE IS A CHANCE CRITICAL FIRE WEATHER CONDITIONS COULD OCCUR MONDAY AFTERNOON IF GROUND MOISTURE DECREASES SUFFICIENTLY AND ALLOWS FOR VERY LOW HUMIDITY VALUES BELOW 10 PERCENT. WINDY TO PERHAPS VERY WINDY WEST TO SOUTHWEST WINDS MAY OCCUR MONDAY AFTERNOON ALONG WITH A WIND SHIFT DUE TO AN APPROACHING COLD FRONT LATE MONDAY AFTERNOON AND NIGHT. MBS && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 13/17
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
557 AM CST FRI FEB 17 2012 .AVIATION... FOR THE 12Z TAFS...THERE IS QUITE A BIT OF UNCERTAINTY WITH RESPECT TO PRECIPITATION TIMING AND FLIGHT CATEGORIES. AT KAMA...EXPECT MVFR CONDITIONS 13-16Z AS -RA IMPACTS THE TAF SITE. AFTERWARD...VFR MAY PREDOMINANTLY PREVAIL THROUGH 23Z...BUT CONFIDENCE IS LOW. AFTER 23Z...HAVE MODERATE CONFIDENCE THAT MVFR CONDITIONS WILL DEVELOP...DETERIORATING TO IFR AFTER 03Z. AFTER 08Z...LIFR OR VLIFR CONDITIONS WILL BE POSSIBLE...BUT CONFIDENCE IN THIS IS CURRENTLY TOO LOW TO MENTION. AT KDHT...HAVE MODERATE CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL THROUGH 20Z WHEN MVFR CIGS DEVELOP. HAVE MODERATE TO HIGH CONFIDENCE THAT CIGS/VSBYS WILL DETERIORATE INTO IFR CATEGORY AFTER 03Z AND POSSIBLY LIFR/VLIFR AFTER 08Z. HOWEVER...CONFIDENCE IS LOW WHETHER LIFR/VLIFR CONDITIONS WILL DEVELOP. AT KGUY...HAVE MODERATE CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL THROUGH 21Z...BUT THERE IS A POSSIBILITY THAT MVFR CONDITIONS MAY DEVELOP AFTER 21Z. HAVE MODERATE CONFIDENCE THAT MVFR CONDITIONS WILL DEVELOP BY 03Z AND DETERIORATING TO IFR CONDITIONS AFTER 06Z. IT/S POSSIBLE THAT LIFR CONDITIONS COULD DEVELOP AFTER 06Z...BUT CONFIDENCE IN THIS IS LOW. -RA IS EXPECTED AT ALL TAF SITES THROUGH THIS PERIOD...BUT TIMING THE ONSET AND ENDING TIMES AT THIS POINT IS NEARLY IMPOSSIBLE. AMENDMENTS WILL BE NEEDED. IT/S POSSIBLE THERE COULD BE A -RASN MIX AT KDHT AFTER 09Z...BUT CONFIDENCE IS TOO LOW TO MENTION AT THIS TIME. A COLD FRONT WILL MOVE THROUGH ALL SITES 06-08Z WITH WINDS SHIFTING TO THE NORTH. JACKSON && .PREV DISCUSSION... /ISSUED 448 AM CST FRI FEB 17 2012/ DISCUSSION... PRECIPITATION CHANCES AND TYPES TODAY THROUGH SATURDAY MORNING ARE THE MAIN FORECAST CHALLENGES. LATEST MODELS WERE IN FAIR TO GOOD AGREEMENT. USED A BLEND WITH A PREFERENCE TOWARDS THE 00Z ECMWF DUE TO IT/S BETTER HANDLING OF MOISTURE AND QPF FIELDS. THE BIGGEST CHANGE TO THE PREVIOUS FORECAST WAS TO LOWER PRECIPITATION CHANCES TODAY ACROSS THE NORTH TEXAS AND OKLAHOMA PANHANDLES. AT 445 AM CST ACROSS THE PANHANDLES...MOSTLY CLOUDY CONDITIONS WERE OCCURRING WITH SURFACE TEMPERATURES MAINLY IN THE 30S. LIGHT RAIN SHOWERS WERE NEAR I-40 EAST OF AMARILLO AND AN AREA OF RAIN SHOWERS WERE JUST SOUTH OF A HEREFORD TO CLOVIS LINE. A MID/UPPER LOW WAS WELL SOUTH OF ARIZONA. THIS MORNING...KEPT THE HIGHEST RAIN CHANCES OVER THE SOUTH TEXAS PANHANDLE...GENERALLY 60 TO 90 PERCENT...THINKING CURRENT AREA OF RAIN SHOWERS MENTIONED ABOVE WILL HOLD TOGETHER. THE 00Z ECMWF DID BEST DEPICTING THIS AREA WITH ITS MOISTURE/QPF FIELDS. DOUBT MUCH...IF ANY RAINFALL...WILL OCCUR NORTH OF A CHANNING TO LIPSCOMB LINE. LATEST RUC13 AND WARM LOW LEVEL THERMAL FIELDS SUGGESTED THAT MOST...IF NOT ALL...OF THE PRECIPITATION WILL BE IN THE FORM OF LIGHT RAIN. RAINFALL AMOUNTS ARE EXPECTED TO RANGE FROM ZERO IN THE OKLAHOMA PANHANDLE UP TO 0.25 INCH SOUTH OF I-40. THERE IS A LITTLE CONCERN THAT THE PRECIPITATION COULD MIX WITH OR BRIEFLY TURN OVER TO LIGHT SNOW AND BRING A QUICK WET INCH OF SNOWFALL WEST OF I-27 AND SOUTH OF I-40 NEAR HEREFORD THIS MORNING...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE QUITE LOW...ESPECIALLY WITH CURRENT SURFACE WET BULB TEMPERATURES A FEW DEGREES ABOVE 32F. THIS AFTERNOON...KEPT RAIN CHANCES...20 TO 50 PERCENT ACROSS THE AREA. THERE MAY BE MORE DRY HOURS THAN WET ONES AND APPEARS ANY ADDITIONAL RAINFALL WILL GENERALLY BE LESS THAN 0.10 INCH. LOW LEVEL TEMPERATURES WILL BE WARM ENOUGH TO SUPPORT ALL RAIN. THE WARMER 00Z MAVMOS HIGHS IN THE 40S APPEARED REASONABLE. TONIGHT INTO SATURDAY MORNING...KEPT PRECIPITATION CHANCES 30 TO 50 PERCENT ACROSS THE AREA TONIGHT...THEN 20 TO 30 PERCENT SATURDAY MORNING. APPEARS ANY PRECIPITATION BEFORE MIDNIGHT WILL BE IN THE FORM OF LIGHT RAIN...THEN TURN OVER TO LIGHT SNOW NORTHWEST TO SOUTHEAST. AT THIS TIME...APPEARS ANY SNOWFALL ACCUMULATIONS WILL BE UNDER ONE HALF INCH. THERE IS A LOW CHANCE A BAND OF SNOW MAY DEVELOP NEAR A DALHART TO BEAVER LINE LATE TONIGHT INTO SATURDAY MORNING WHICH COULD BRING LOCALLY ENHANCE SNOWFALL AND BRING ONE TO TWO INCHES TO THESE AREAS...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE VERY LOW...ESPECIALLY AS NOT SURE PHASING WILL OCCUR WITH MID/UPPER TROUGHS MOVING OVER THE AREA. IN ADDITION...APPEARS THE BEST MOISTURE WILL BE CUT OFF AND OVER SOUTH TEXAS. WENT CLOSER TO THE WARMER 00Z MAVMOS LOWS. SATURDAY AFTERNOON THROUGH SUNDAY NIGHT...DRY CONDITIONS ARE EXPECTED. CLOUDS WILL BE SLOW TO CLEAR SATURDAY AFTERNOON...SO LOWERED HIGHS CLOSER TO THE COLDER 00Z MAVMOS NUMBERS. THERE IS A LOW CHANCE FOR LIGHT FREEZING FOG SUNDAY MORNING...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. BREEZY AND WARMER CONDITIONS WILL RETURN SUNDAY AFTERNOON UNDER MOSTLY SUNNY SKIES. MONDAY INTO MONDAY NIGHT...WINDY CONDITIONS SEEM LIKELY...ESPECIALLY MONDAY AFTERNOON. MAY BE CLOSE TO ADVISORY LEVEL OF 35 MPH SUSTAINED FOR 3 OR MORE HOURS. KEPT A DRY FORECAST FOR NOW AS APPEARS THE BEST MOISTURE AND LIFT WILL STAY NORTH AND EAST OF THE AREA. WENT NEAR OR ABOVE THE WARMER 00Z MEXMOS HIGHS. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA LATE AFTERNOON AND NIGHT. TUESDAY THROUGH THURSDAY...DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. LATEST MODELS WERE IN SOME DISAGREEMENT WITH SURFACE FEATURES. STAYED CLOSE TO THE 00Z MEXMOS TEMPERATURES. MBS FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH THIS WEEKEND. ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE MONDAY AFTERNOON ACROSS MUCH OF THE TEXAS PANHANDLE DUE WINDY CONDITIONS AND LOW HUMIDITY. THERE IS A CHANCE CRITICAL FIRE WEATHER CONDITIONS COULD OCCUR MONDAY AFTERNOON IF GROUND MOISTURE DECREASES SUFFICIENTLY AND ALLOWS FOR VERY LOW HUMIDITY VALUES BELOW 10 PERCENT. WINDY TO PERHAPS VERY WINDY WEST TO SOUTHWEST WINDS MAY OCCUR MONDAY AFTERNOON ALONG WITH A WIND SHIFT DUE TO AN APPROACHING COLD FRONT LATE MONDAY AFTERNOON AND NIGHT. MBS && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ JJ/MBS
AREA FORECAST DISCUSSION
NWS AMARILLO TX
448 AM CST FRI FEB 17 2012 .DISCUSSION... PRECIPITATION CHANCES AND TYPES TODAY THROUGH SATURDAY MORNING ARE THE MAIN FORECAST CHALLENGES. LATEST MODELS WERE IN FAIR TO GOOD AGREEMENT. USED A BLEND WITH A PREFERENCE TOWARDS THE 00Z ECMWF DUE TO IT/S BETTER HANDLING OF MOISTURE AND QPF FIELDS. THE BIGGEST CHANGE TO THE PREVIOUS FORECAST WAS TO LOWER PRECIPITATION CHANCES TODAY ACROSS THE NORTH TEXAS AND OKLAHOMA PANHANDLES. AT 445 AM CST ACROSS THE PANHANDLES...MOSTLY CLOUDY CONDITIONS WERE OCCURRING WITH SURFACE TEMPERATURES MAINLY IN THE 30S. LIGHT RAIN SHOWERS WERE NEAR I-40 EAST OF AMARILLO AND AN AREA OF RAIN SHOWERS WERE JUST SOUTH OF A HEREFORD TO CLOVIS LINE. A MID/UPPER LOW WAS WELL SOUTH OF ARIZONA. THIS MORNING...KEPT THE HIGHEST RAIN CHANCES OVER THE SOUTH TEXAS PANHANDLE...GENERALLY 60 TO 90 PERCENT...THINKING CURRENT AREA OF RAIN SHOWERS MENTIONED ABOVE WILL HOLD TOGETHER. THE 00Z ECMWF DID BEST DEPICTING THIS AREA WITH ITS MOISTURE/QPF FIELDS. DOUBT MUCH...IF ANY RAINFALL...WILL OCCUR NORTH OF A CHANNING TO LIPSCOMB LINE. LATEST RUC13 AND WARM LOW LEVEL THERMAL FIELDS SUGGESTED THAT MOST...IF NOT ALL...OF THE PRECIPITATION WILL BE IN THE FORM OF LIGHT RAIN. RAINFALL AMOUNTS ARE EXPECTED TO RANGE FROM ZERO IN THE OKLAHOMA PANHANDLE UP TO 0.25 INCH SOUTH OF I-40. THERE IS A LITTLE CONCERN THAT THE PRECIPITATION COULD MIX WITH OR BRIEFLY TURN OVER TO LIGHT SNOW AND BRING A QUICK WET INCH OF SNOWFALL WEST OF I-27 AND SOUTH OF I-40 NEAR HEREFORD THIS MORNING...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE QUITE LOW...ESPECIALLY WITH CURRENT SURFACE WET BULB TEMPERATURES A FEW DEGREES ABOVE 32F. THIS AFTERNOON...KEPT RAIN CHANCES...20 TO 50 PERCENT ACROSS THE AREA. THERE MAY BE MORE DRY HOURS THAN WET ONES AND APPEARS ANY ADDITIONAL RAINFALL WILL GENERALLY BE LESS THAN 0.10 INCH. LOW LEVEL TEMPERATURES WILL BE WARM ENOUGH TO SUPPORT ALL RAIN. THE WARMER 00Z MAVMOS HIGHS IN THE 40S APPEARED REASONABLE. TONIGHT INTO SATURDAY MORNING...KEPT PRECIPITATION CHANCES 30 TO 50 PERCENT ACROSS THE AREA TONIGHT...THEN 20 TO 30 PERCENT SATURDAY MORNING. APPEARS ANY PRECIPITATION BEFORE MIDNIGHT WILL BE IN THE FORM OF LIGHT RAIN...THEN TURN OVER TO LIGHT SNOW NORTHWEST TO SOUTHEAST. AT THIS TIME...APPEARS ANY SNOWFALL ACCUMULATIONS WILL BE UNDER ONE HALF INCH. THERE IS A LOW CHANCE A BAND OF SNOW MAY DEVELOP NEAR A DALHART TO BEAVER LINE LATE TONIGHT INTO SATURDAY MORNING WHICH COULD BRING LOCALLY ENHANCE SNOWFALL AND BRING ONE TO TWO INCHES TO THESE AREAS...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE VERY LOW...ESPECIALLY AS NOT SURE PHASING WILL OCCUR WITH MID/UPPER TROUGHS MOVING OVER THE AREA. IN ADDITION...APPEARS THE BEST MOISTURE WILL BE CUT OFF AND OVER SOUTH TEXAS. WENT CLOSER TO THE WARMER 00Z MAVMOS LOWS. SATURDAY AFTERNOON THROUGH SUNDAY NIGHT...DRY CONDITIONS ARE EXPECTED. CLOUDS WILL BE SLOW TO CLEAR SATURDAY AFTERNOON...SO LOWERED HIGHS CLOSER TO THE COLDER 00Z MAVMOS NUMBERS. THERE IS A LOW CHANCE FOR LIGHT FREEZING FOG SUNDAY MORNING...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. BREEZY AND WARMER CONDITIONS WILL RETURN SUNDAY AFTERNOON UNDER MOSTLY SUNNY SKIES. MONDAY INTO MONDAY NIGHT...WINDY CONDITIONS SEEM LIKELY...ESPECIALLY MONDAY AFTERNOON. MAY BE CLOSE TO ADVISORY LEVEL OF 35 MPH SUSTAINED FOR 3 OR MORE HOURS. KEPT A DRY FORECAST FOR NOW AS APPEARS THE BEST MOISTURE AND LIFT WILL STAY NORTH AND EAST OF THE AREA. WENT NEAR OR ABOVE THE WARMER 00Z MEXMOS HIGHS. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA LATE AFTERNOON AND NIGHT. TUESDAY THROUGH THURSDAY...DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. LATEST MODELS WERE IN SOME DISAGREEMENT WITH SURFACE FEATURES. STAYED CLOSE TO THE 00Z MEXMOS TEMPERATURES. MBS && .FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH THIS WEEKEND. ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE MONDAY AFTERNOON ACROSS MUCH OF THE TEXAS PANHANDLE DUE WINDY CONDITIONS AND LOW HUMIDITY. THERE IS A CHANCE CRITICAL FIRE WEATHER CONDITIONS COULD OCCUR MONDAY AFTERNOON IF GROUND MOISTURE DECREASES SUFFICIENTLY AND ALLOWS FOR VERY LOW HUMIDITY VALUES BELOW 10 PERCENT. WINDY TO PERHAPS VERY WINDY WEST TO SOUTHWEST WINDS MAY OCCUR MONDAY AFTERNOON ALONG WITH A WIND SHIFT DUE TO AN APPROACHING COLD FRONT LATE MONDAY AFTERNOON AND NIGHT. MBS && .PRELIMINARY POINT TEMPS/POPS... AMARILLO TX 44 32 39 25 56 / 80 40 20 0 0 BEAVER OK 51 31 41 24 52 / 30 50 30 0 0 BOISE CITY OK 48 27 41 21 55 / 20 40 20 0 0 BORGER TX 45 32 41 28 56 / 60 40 20 0 0 BOYS RANCH TX 44 29 39 26 57 / 70 50 20 0 0 CANYON TX 44 31 40 24 56 / 90 40 20 0 0 CLARENDON TX 45 35 44 27 56 / 90 40 30 0 0 DALHART TX 45 28 40 21 57 / 40 50 20 0 0 GUYMON OK 48 29 44 23 54 / 30 50 20 0 0 HEREFORD TX 43 30 43 25 57 / 90 40 20 0 0 LIPSCOMB TX 47 34 41 22 53 / 40 50 30 0 0 PAMPA TX 46 33 41 24 53 / 70 40 30 0 0 SHAMROCK TX 49 36 42 25 54 / 80 40 30 0 0 WELLINGTON TX 49 37 45 27 54 / 80 40 30 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 13/17
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
546 AM CST FRI FEB 17 2012 .SHORT TERM... 305 AM CST FRI FEB 17 2012 MAIN FORECAST CONCERN IS ON PRECIPITATION CHANCES TODAY. 07Z WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH OVER NORTH DAKOTA. AT THE SURFACE...A WEAK COLD FRONT WAS SITUATED FROM NORTHERN MINNESOTA...BACK INTO EASTERN SOUTH DAKOTA. BAND OF MAINLY MID LEVEL CLOUDS WERE SEEN AHEAD OF IT ACROSS MINNESOTA. 17.00Z MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. SHORTWAVE OVER NORTH DAKOTA WILL ROTATE SOUTHEAST AND ACROSS THE FORECAST AREA TODAY...AS SURFACE COLD FRONT AND WEAK SURFACE LOW PUSHES THROUGH THE AREA. BOTH THE GFS AND NAM SHOWING A SWATH OF QG CONVERGENCE BETWEEN 850MB-500MB ALONG WITH SOME 285K-295K ISENTROPIC LIFT. IN ADDITION...850MB-700MB LAPSE RATES RATHER STEEP 7-9 DEGREES CELSIUS PER KILOMETER BY THIS AFTERNOON. RUC ALSO SHOWING UPWARDS OF 200 J/KG OF 0-3KM MOST UNSTABLE CAPE OVER THE NORTHEASTERN PORTION OF THE FORECAST AREA. THE BIGGEST QUESTION WILL BE DEGREE OF SATURATION. 17.06Z RUC BUFKIT SOUNDINGS SHOWS BEST SATURATION TO THE NORTH OF INTERSTATE 94...WITH AREAS SOUTH OF THERE SATURATION OCCURS ABOVE 900MB. DID RAISE PROBABILITIES A LITTLE ACROSS THE NORTHEAST. WITH MILD PACIFIC AIRMASS IN PLACE AND SURFACE TEMPERATURES EXPECTED INTO THE MIDDLE 30S TO THE LOWER 40S DID MENTION BOTH RAIN AND SNOW SHOWERS. SHORTWAVE EXITS EAST OF THE AREA TONIGHT WITH ONLY SOME LINGERING PRECIPITATION EARLY IN THE EVENING ACROSS THE EASTERN COUNTIES. OTHERWISE...BOTH THE NAM AND GFS INDICATE SOME STRATUS BEHIND THE FONT TO SETTLE OVER THE AREA...MAINLY ACROSS THE NORTHEAST SECTIONS OF THE FORECAST AREA. THESE CLOUDS WILL MOVE OUT RATHER QUICKLY ON SATURDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA. THIS SURFACE HIGH WILL REMAIN OVERHEAD THROUGH SUNDAY WITH CLEAR SKIES...LIGHT WINDS AND SEASONABLE TEMPERATURES. .LONG TERM... 305 AM CST FRI FEB 17 2012 BOTH THE 17.00Z GFS AND ECMWF SHOWING A MORE ACTIVE WEATHER PATTERN DURING THIS TIME FRAME. LONGWAVE TROUGH PUSHES OUT OF THE CENTRAL CONUS MONDAY AND ACROSS THE AREA MONDAY NIGHT INTO TUESDAY. GFS IS SHOWING A MORE NORTH/SOUTH SPLIT OF THE ENERGY VERSUS THE ECMWF...ALTHOUGH THE ECMWF TO A LESSER EXTENT IS ALSO SHOWING THIS TREND. THUS...SURFACE LOW LOOKS TO BE SOMEWHAT WEAKER. GULF WILL BE OPEN AHEAD OF THE SYSTEM WHICH WILL ALLOW FOR A GOOD FETCH OF MOISTURE AHEAD OF IT. WITH PACIFIC AIRMASS REMAINING IN PLACE QUESTION WILL BE PRECIPITATION TYPES...WITH A LIKELY SCENARIO OF MAINLY SNOW MONDAY NIGHT AND RAIN/SNOW TUESDAY. ANOTHER WAVE DROPS THROUGH THE AREA WEDNESDAY THROUGH THURSDAY AND KEPT PRECIPITATION CHANCES IN THE FORECAST WITH RAIN/SNOW MIX. ALL IN ALL...TEMPERATURES LOOK TO REMAIN MILD AND ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...TODAY AND TONIGHT 546 AM CST FRI FEB 17 2012 WILL BE WATCHING A WEAK AREA OF LOW PRESSURE AND COLD FRONT MOVE ACROSS THE AREA TODAY. MOST OF THE LIFT AND THREAT FOR ANY PRECIPITATION ASSOCIATED WITH THIS SYSTEM APPEARS TO BE THIS MORNING. A BRIEF SNOW SHOWER PASSED THROUGH KONA AROUND 1058Z WHICH DROPPED THE VISIBILITY BRIEFLY TO AROUND A MILE. THIS SNOW SHOWER THREAT APPEARS TO LINGER THROUGH THIS MORNING MAINLY ALONG/EAST OF THE MISSISSIPPI RIVER. BASED ON THIS...HAVE OPTED TO KEEP VCSH IN THE KLSE THROUGH THIS MORNING. OTHERWISE...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THIS MORNING. LOOK FOR THE COLD FRONT TO PASS THROUGH KRST AROUND 18Z AND AT KLSE BY 21Z...WHICH WILL SWING THE WINDS TO THE NORTHWEST WITH SOME GUSTINESS INTO THE 15 TO 20KT RANGE. GFS/NAM MODELS THEN SHOW SOME LOWER LEVEL MOISTURE/MVFR CLOUD ROTATING INTO THE AREA THIS AFTERNOON BEHIND THE FRONT...LINGERING INTO THE OVERNIGHT HOURS. THE BULK OF THIS CLOUD APPEARS TO BE CONFINED ALONG AND EAST OF THE MISSISSIPPI RIVER. AS A RESULT...KEPT KRST VFR WHILE KLSE WILL LIKELY GO TO MVFR BY 01Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 305 AM CST FRI FEB 17 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RABERDING LONG TERM...RABERDING AVIATION...DAS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
339 PM EST FRI FEB 17 2012 .SHORT TERM... AREA OF ISENTROPIC LIFT AHEAD OF APPROACHING CLIPPER SYSTEM WAS GENERATING AN AREA OF LIGHT SNOW JUST TO OUR NORTH THIS AFTERNOON. REGIONAL RADAR MOSAIC COUPLED WITH HIGH RES GUIDANCE SUGGEST THIS WILL REMAIN JUST NORTH OF FORECAST AREA EARLY THIS EVENING. HOWEVER...AS SURFACE LOW DROPS SOUTH AND EAST LIGHT PCPN WILL AGAIN BE POSSIBLE AND HRRR SHOWS THIS AFTER ABOUT 01Z. WILL MAINTAIN A LOW CHANCE POP FOR THIS LIGHT PRECIPITATION POSSIBILITY ACROSS THE FAR NORTH AS MOISTURE AHEAD OF THIS SYSTEM REMAINS LIMITED. AS LOW PASSES AND COLD AIR ADVECTION DEVELOPS SHOULD SEE AN INCREASE IN LOW AND MID LEVEL MOISTURE WITH AID OF LAKE MICHIGAN. DELTA T VALUES INCREASE TO LOWER TEENS WHICH SHOULD BE ENOUGH TO HELP IN LAKE CLOUD GENERATION AND SOME LIGHT SNOW SHOWERS IN THE NORTH. ANY ACCUMS EXPECTED TO BE LIGHT AND WILL DEPEND ON DEPTH OF MOISTURE COLUMN. HIGH PRESSURE QUICKLY MOVES IN ON SATURDAY WITH CLEARING SKIES IN AFTERNOON AS FLOW VEERS. INCREASE IN HIGH CLOUDS POSSIBLE SATURDAY NIGHT AS SOUTHERN STREAM SYSTEMS DEEPENS AND SPREADS HIGH LEVEL MOISTURE NORTH. PRECIPITATION EXPECTED TO REMAIN WELL SOUTH OF FORECAST AREA. && .LONG TERM... SUNDAY THROUGH FRIDAY... PLEASANT WEATHER PATTERN TO BEGIN THE FORECAST PERIOD WITH SFC HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION ON SUNDAY THEN DRIFTING SE INTO OH VALLEY ON MONDAY. AFTER SEASONABLE TEMPERATURES ON SUNDAY WILL SEE A WARMUP TO BEGIN NEXT WEEK AS MID LEVEL RIDGING BUILDS EASTWARD INTO THE AREA IN RESPONSE TO STRONG JET DYNAMICS COMING ONSHORE IN PACIFIC NW WHICH WILL REINFORCE TROUGH OVER FOUR CORNERS. MEDIUM RANGE MODELS OFFERING VARIED SOLNS IN HANDLING ENERGY EJECTING OUT OF TROUGH...BUT ALL INDICATIONS POINT TO PERIOD OF UNSETTLED WEATHER MIDDLE PORTION OF NEXT WEEK. ONE COMMON THEME AND AN AREA OF HIGHER CONFIDENCE AMONG THE MODELS IS THE PHASING OF NORTHERN AND SOUTHERN STREAMS AND SUBSEQUENT BROAD LONGWAVE TROUGH CARVED OUT FROM THE PLAINS TO GREAT LAKES REGION THURSDAY-FRIDAY TIMEFRAME. WHILE TIMING AND DETAILS OF RESULTING SENSIBLE WEATHER REMAIN UNCERTAIN...PATTERN SUGGESTS KEEPING POPS IN FCST TUE-THU AND ABSENCE OF ANY SIGNS OF SFC RIDGING BUILDING IN BEHIND THIS SYSTEM FAVORS CONTINUED CYCLONIC FLOW AND SMALL CHANCE POPS FRI AS WELL.&& .AVIATION... MID LEVEL CLOUDS SHOULD INCREASE AT KSBN THROUGH THE AFTERNOON AND AT KFWA LATER THIS EVENING AS SHORT WAVE MOVES BY TO THE NORTH. VFR CONDITIONS EXPECTED REST OF TODAY AND THIS EVENING. AS SURFACE LOW PASSES TO THE NORTH AND FLOW BECOMES NORTHWEST OVERNIGHT SHOULD SEE LAKE CLOUD DEVELOPMENT. MODEL SOUNDINGS SUGGEST MVFR CIGS AT KSBN TOWARD DAYBREAK. PCPN EXPECTED TO BE LIGHT AND MAINLY NORTH OF TAF SITES BUT KSBN WILL BE ON SOUTHERN FRINGE. COULD SEE SOME FLURRIES WITH LAKE CLOUDS AND COLD AIR ADVECTION EARLY SAT MORNING. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...LASHLEY LONG TERM...LOGSDON AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS DES MOINES IA
330 PM CST FRI FEB 17 2012 .SHORT TERM /TONIGHT/... LATEST WV IMAGERY WITH H500 RUC ANALYSIS SHOWED CONFLUENT UPPER LEVEL FLOW ACROSS THE MISSOURI RIVER VALLEY ONCE AGAIN...WITH ANOTHER WEAK SHORTWAVE APPROACHING THE MT/ND BORDER. A STRIP OF POSITIVE VORTICITY ORIENTED EAST/WEST FROM CENTRAL SOUTH DAKOTA THROUGH CENTRAL WISCONSIN IS A RESULT OF SPEED SHEAR ASSOCIATED WITH THE ZONAL FLOW TO THE SOUTH...AND NORTHERLY FLOW TO THE NORTH. THIS FEATURE WILL REMAIN FAIRLY TRANSIENT...SO WITH LITTLE PVA...IT SHOULD HAVE LITTLE IMPACT ON THE SURFACE. IN ADDITION...SUBSIDENCE ASSOCIATED WITH THE LEFT ENTRANCE REGION OF THE UPPER LEVEL JET AND THE ANTICYCLONIC CURVATURE OF THE UPPER LEVEL FLOW WILL CAUSE A SURFACE HIGH PRESSURE TO BUILD INTO CENTRAL IOWA AS SHOWN IN THE 6HR SURFACE ISALLOBARIC MAP. THIS SURFACE HIGH WILL REDUCE WINDS OVERNIGHT...WHICH COULD ALLOW TEMPS TO FALL OFF. HOWEVER...CELLULAR STRATUS DECK SPREADING ACROSS ALL OF MINNESOTA COULD LIMIT THE RADIATIONAL COOLING IF IT HOLDS TOGETHER AFTER SUNSET AND MOVES INTO NORTHERN IOWA. FORECAST SOUNDINGS AND TIME/HEIGHT CROSS SECTIONS SHOW THIN LAYER OF HIGH RH IN THE LOWEST LEVELS OF THE BOUNDARY LAYER. ANTICIPATING THIS TO TAKE SHAPE AS MORE OF A SCATTERED VS BROKEN DECK OF CLOUDS...SO HAVE KEPT LOW TEMPS IN THE TEENS ACROSS THE NORTHWESTERN CWA...WITH WARMER TEMPS IN THE SOUTHEAST. .LONG TERM /SATURDAY THROUGH FRIDAY/... LITTLE CHANGE IN THE OVERALL LONG TERM FORECAST WITH TIMING AND PLACEMENT DETAILS OF ATMOSPHERIC FEATURES REMAINING CONSISTENT THE PAST FEW DAYS. TEMPERATURES THIS WEEKEND WILL BE NEAR TO A LITTLE ABOVE SEASONAL VALUES THOUGH SHOULD BE ABOVE GUIDANCE VALUES. DRY CONDITIONS WILL PREVAIL THROUGH THE WEEKEND. WELL ADVERTISED UPPER LEVEL SYSTEM IS STILL ON TRACK TO IMPACT THE STATE MONDAY THROUGH EARLY TUESDAY. PRECIPITATION TYPE DUE TO SOME UNCERTAINTY OF LOW LEVEL TEMPERATURE PROFILE REMAINS THE PRIMARY CHALLENGE WITH THE SYSTEM. THE PAST SEVERAL EVENTS IN ADDITION TO LOW LEVEL FORECAST PROFILES SUGGEST THE PRECIPITATION WILL BE MAINLY RAIN FOR THE SOUTHERN HALF TO TWO-THIRDS OF THE FORECAST AREA. THE PRECIPITATION TYPE BECOMES MUCH MORE PROBLEMATIC OVER NORTHERN IOWA. VERY WELL COULD HAVE A TRANSITION ZONE TO ALL SNOW OVER THE NORTHERN FEW TIER OF COUNTIES AND COULD RESULT IN MODERATE SNOWFALL ACCUMULATIONS. WILL ADD THE POTENTIAL TO THE HWO. ANOTHER SHORTWAVE STILL ON TRACK MID NEXT WEEK. PROFILES ARE A BIT COLDER WITH THIS SYSTEM AND COULD RESULT IN A MORE WIDESPREAD LIGHT SNOW EVENT. LOW PRECIPITATION CHANCES AROUND TO END THE FORECAST PERIOD HOWEVER ANYTHING THAT WOULD OCCUR WOULD BE QUITE LIGHT. && .AVIATION...17/18Z A COLD FRONT IS MOVING SOUTHEAST ACROSS THE STATE...AND IS MOST EVIDENT BY THE WIND SHIFT FROM SOUTHWEST TO NORTHWEST AS IT PASSES THROUGH. A THIN STRATUS DECK CURRENTLY LOCATED OVER THE DAKOTA/MINNESOTA BORDER IS HEADING TOWARD NORTHERN IOWA...BUT STILL UNSURE IF THIS WILL HOLD TOGETHER BY THE TIME IT ARRIVES THIS EVENING. THEREFORE JUST HAVE SCATTERED DECK IN THE TAF. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...BEITLICH LONG TERM...DONAVON AVIATION...BEITLICH
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
352 PM EST FRI FEB 17 2012 .SYNOPSIS... ISSUED AT 238 PM EST FRI FEB 17 2012 AN AREA OF LOW PRESSURE WILL TRACK EASTWARD THROUGH LOWER MICHIGAN TONIGHT PRODUCING SOME SNOWFALL. AN AREA OF HIGH PRESSURE WILL ARRIVE FOR SATURDAY NIGHT. THIS FAIR WEATHER SYSTEM WILL KEEP THE AREA DRY GOING INTO EARLY NEXT WEEK. A SLOW MOVING COLD FRONT WILL ARRIVE FOR THE MIDDLE PART OF NEXT WEEK WITH SOME RAIN OR SNOW. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 238 PM EST FRI FEB 17 2012 RADAR SHOWS A DEVELOPING AREA OF SNOW FROM NEAR GRAND RAPIDS WEST THROUGH THE MIDDLE PART OF LAKE MI. SOME INSTABILITY WAS PRESENT MAINLY FROM 850 MB TO 700 MB. THE BEST LIFT AND MOISTURE IN THE DGZ TRACKS FROM NEAR MUSKEGON TO HOLLAND AT 21Z TO CADILLAC AND MT PLEASANT BY 03Z. DEEP DRYING ARRIVES IN MUSKEGON BY 03Z...WHICH SHOULD SHUT DOWN THE HIGH RISK FOR MEASURABLE PRECIPITATION. THE HRRR RUC DOES SHOW A SUDDEN DEVELOPMENT OF SNOW IN THE 23Z TO 01Z TIMEFRAME JUST WEST OF HOLLAND AND SOUTH HAVEN WHICH TRACKS EAST INTO SOUTHWEST LOWER MI...WHICH WOULD PROLONG THE RISK FOR ACCUMULATING SNOW BEYOND 03Z. COLDER SURFACES COULD SEE AN INCH WITH LOCALLY HIGHER AMOUNTS WHERE ANY BAND PERSISTS. MUCH OF THAT SNOW COULD FALL IN AN HOURS TIME EARLY THIS EVENING. WRAP AROUND MOISTURE ON THE BACKSIDE OF THE DEPARTING LOW COULD LEAD TO A RETURN OF SOME SNOW FOR LATE TONIGHT INTO SATURDAY MORNING. AS A RESULT I WILL KEEP THE HIGHER POPS GOING TONIGHT...MAINLY FOR THE FIRST HALF OF THE NIGHT. WILL KEEP THE MENTION OF SNOW GOING INTO SATURDAY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 238 PM EST FRI FEB 17 2012 (SUNDAY THROUGH FRIDAY) AS A STORM MOVES ALONG THE GULF COAST...HIGH PRESSURE WILL HOVER OVER THE GREAT LAKES SUNDAY AND MONDAY. AFTER MONDAY A CLIPPER AND A WAVE MOVING EAST FROM THE ROCKIES ARE PROGD TO PHASE NEAR THE GREAT LAKES TUESDAY. THE RESULT WILL BE A PERIOD OF SNOW TUESDAY NORTH OF I-96 AND GENERALLY RAIN SOUTH OF THERE. TWO MORE CLIPPERS...ONE ON WEDNESDAY AND ANOTHER THURSDAY NIGHT WILL RESULT IN PCPN FROM WED INTO FRIDAY. THE WEDNESDAY CLIPPER WILL DRAW A BIT MORE WARM AIR NORTHWARD INTO THE REGION WHICH WILL RESULT IN SOME MORE LIGHT RAIN OVER THE SRN HALF OF THE CWA WEDNESDAY BEFORE IT MOVES THROUGH. AS COLDER AIR FLOWS IN BEHIND IT...WE/LL HAVE A BETTER CHANCE AT SOME LIGHT SNOW BY THE TIME THE THURSDAY NIGHT CLIPPER ARRIVES. FROM THURSDAY INTO FRIDAY....THE LIGHT PCPN THAT FALLS WILL BE IN THE FORM OF SNOW. && .AVIATION...(FOR THE 21Z TAFS THROUGH 21Z SATURDAY AFTERNOON) ISSUED AT 238 PM EST FRI FEB 17 2012 SNOW SHOWERS WILL MOVE IN QUICKER THAN FORECASTED AND TAFS HAVE BEEN UPDATED TO ACCOUNT FOR THIS. ADDED IFR TO THE FORECAST FOR KGRR AND KLAN AS WELL. UPSTREAM CONDITIONS HAVE BRIEFLY GONE DOWN TO IFR AT MULTIPLE SITES. THE DURATION OF ANY IFR WILL LIKELY BE LIMITED...BUT A RISK WILL EXIST INTO THE EVENING FOR KGRR AND KMKG. LOWER CLOUDS WILL LIKELY LINGER INTO SAT AM WITH THE PASSAGE OF THE LOW PRESSURE SYSTEM. && .MARINE... ISSUED AT 238 PM EST FRI FEB 17 2012 SMALL CRAFT ADVISORY ISSUED FOR INCREASING WINDS AND WAVES TONIGHT. && .HYDROLOGY... ISSUED AT 330 AM EST FRI FEB 17 2012 RELATIVELY QUIET WITH THE HYDRO SECTION FOR THIS TIME OF THE YEAR. NO SIGNIFICANT RUNOFF FORECASTED THROUGH MONDAY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY LATE TONIGHT THROUGH SATURDAY NIGHT. && $$ SYNOPSIS...MJS SHORT TERM...MJS LONG TERM....93 AVIATION...MJS MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
100 PM EST FRI FEB 17 2012 .UPDATE... ISSUED AT 1245 PM EST FRI FEB 17 2012 SOUTHWARD EXTENSION OF THE SNOW IN SRN WI...SHOULD CLIP PARTS OF MY SOUTHERN COUNTIES LATER THIS AFTERNOON/EVENING AS ADVERTISED BY THE HRRR RUC. POPS HAVE BEEN INCREASED TO ACCOUNT FOR THIS THIS AFTERNOON. UPDATE ISSUED AT 1052 AM EST FRI FEB 17 2012 INCOMING MODEL DATA IS SHOWING SOME INSTABILITY AS THE AREA OF SNOW PULLS THROUGH LOWER MI LATER THIS AFTERNOON INTO THIS EVENING. UPSTREAM SAT IMAGERY SHOWS A CONVECTIVE APPEARANCE TO THE CLOUDS AND OBS HAVE INDICATED CONVECTIVE BURSTS. THUS I TOOK OUT THE LIGHT WORDING AND ALSO FEATURED MORE SNOW FOR THE AFTERNOON. HWO WAS UPDATED TO INDICATE POTENTIAL IMPACTS. BY 21Z SNOW COULD REACH HIGHWAY 131 GRR TO CAD. ISSUED AT 928 AM EST FRI FEB 17 2012 ADDED SOME SNOW TO THE LATE AFTERNOON FORECAST AROUND LUDINGTON. THE WEAK WAVE OF LOW PRESSURE MOVING IN FROM THE WEST WILL ARRIVE ACROSS MY NORTHWEST COUNTIES PRIOR TO 00Z. FAVORABLE MOISTURE IN THE DGZ COMBINED WITH STRONGER OMEGA VALUES SUPPORTS THIS ALONG WITH BUMPING UP POPS TO CATEGORICAL FOR THE REGION NORTH OF A HART TO MT PLEASANT LINE. ALONG AND SOUTH OF INTERSTATE 96 WE MAY HAVE TROUBLE MEASURING. BY 03Z THE MAIN AREA OF PRECIP SHOULD BE MOVING EAST OF LUDINGTON AS THE DGZ WILL BE DRYING OUT. SOUNDINGS AT 21Z DO HAVE A SHALLOW MELTING LAYER...BUT BY 00Z THEY ARE SEVERAL DEGREES BELOW FREEZING. SO WILL KEEP THE PRECIP TYPE AS SNOW. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 330 AM EST FRI FEB 17 2012 HIGH PRESSURE TO BRING FAIR WX TODAY WITH PARTLY CLOUDY SKIES AND SEASONABLY MILD MAX TEMPS REACHING THE UPPER 30S TO LOWER 40S. WEAK LOW PRESSURE MOVING ESE ACROSS LWR MI TONIGHT WILL BRING LIGHT SNOW. THERE IS A NARROW WINDOW OF DEEPER MOISTURE ALONG WITH DECENT OMEGAS BY EARLY TO MID EVENING AND WE WILL GO WITH LIKELY POPS FOR MUCH OF OUR FCST AREA FOR LIGHT SNOW THIS EVE. THE BEST CHC FOR LIGHT SNOW SHOULD COME NEAR TO NORTH OF I-96. WILL GO WITH CHC POPS FOR OUR FAR SOUTHERN COUNTIES. ACCUMULATIONS TONIGHT SHOULD BE RATHER LIGHT... GENERALLY AROUND AN INCH OR LESS... TO PERHAPS LOCALLY TWO INCHES IN A FEW SPOTS NORTH OF I-96. COLDER AIR ADVECTS IN SATURDAY WITH H8 TEMPS FALLING TO -11 TO -14 C BY 00Z SUN. THIS IN CONJUNCTION WITH SOME LINGERING LOW LEVEL MOISTURE SHOULD BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES. ANY ACCUMULATIONS SATURDAY SHOULD BE VERY LIGHT (TRACE AMOUNTS TO LESS THAN AN INCH). .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM EST FRI FEB 17 2012 FROM SATURDAY NIGHT INTO MONDAY NIGHT THE WEATHER SHOULD BE RATHER TRANQUIL AND FOR THE MOST PART ON THE WARM SIDE OF NORMAL. THE REST OF THE LONG TERM FORECAST PERIOD LOOKS UNSETTLED WITH PERIODS OF LIGHT RAIN AND LIGHT SNOW. EVEN SO...TOTAL QPF FOR THIS ENTIRE WEEK SHOULD BE LESS THAN A HALF INCH IN MOST AREAS. THE 180 TO 200 KNOT JET STREAK COMING OFF ASIA (CROSSES JAPAN DURING THE DAY TIME HOURS OF TODAY) WILL BE OUR WEATHER CHANGER IN THE LONG TERM. AS THAT JET STREAK REACHES THE DATELINE EARLY NEXT WEEK IT HELPS TO BUILD A WESTERN RIDGE WHICH IN TURN DEEPENS THE CENTRAL UNITED STATES TROUGH. A SERIES OF SHORTWAVES MOVE THROUGH THE DEVELOPING TROUGH TUESDAY THROUGH THURSDAY BUT NO BIG STORM COMES OUT... JUST A SERIES OF SHORT WAVES. BEING ON THE UPSTREAM SIDE OF THE TROUGH... WARM AIR LARGELY PREVAILS THROUGH THURSDAY WITH A SLIGHT COOLING TREND THURSDAY. IN THE THURSDAY TIME FRAME IS WHEN SOME OF THE COOLER AIR STARTS TO FILTER SO I FEATURE FALLING TEMPERATURES DURING THE AFTERNOON THURSDAY AND CHANGE THE RAIN TO SNOW DURING THE DAY THURSDAY. I HAVE ABOVE AVERAGE CONFIDENCE IN THE OVERALL IDEA BEHIND THE FORECAST BUT SINCE WE ARE WATCHING WEAK SHORTWAVES TRAVEL ALONG IN THE LARGE SCALE FLOW... THE DETAILS OF WHEN AND WHERE THE RAINS/SNOWS WILL BE TUE THROUGH THURSDAY ARE DUBIOUS AT BEST. IN THE PERIOD FROM SATURDAY NIGHT THROUGH MONDAY NIGHT SHORTWAVE RIDGING PREVAILS. THAT WELL LEAD TO LIMITED CLOUD COVER AND UNSEASONABLY MILD TEMPERATURE (REMEMBER THE POLAR JET IS STILL LOCKING UP THE TRULY COLD AIR NORTH OF 55 N). && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1245 PM EST FRI FEB 17 2012 SNOW SHOWERS WILL MOVE IN QUICKER THAN FORECASTED AND TAFS HAVE BEEN UPDATED TO ACCOUNT FOR THIS. ADDED IFR TO THE FORECAST FOR KGRR AND KLAN AS WELL. UPSTREAM CONDITIONS HAVE BRIEFLY GONE DOWN TO IFR AT MULTIPLE SITES. THE DURATION OF ANY IFR WILL LIKELY BE LIMITED...BUT A RISK WILL EXIST INTO THE EVENING FOR KGRR AND KMKG. LOWER CLOUDS WILL LIKELY LINGER INTO SAT AM WITH THE PASSAGE OF THE LOW PRESSURE SYSTEM. && .MARINE... ISSUED AT 1245 PM EST FRI FEB 17 2012 THE SMALL CRAFT ADVISORY HAS EXPIRED. WINDS ARE LIKELY TO STAY UNDER 25 KNOTS THROUGH TONIGHT. WINDS WILL INCREASE SOMEWHAT ON SATURDAY AND MAY REACH SMALL CRAFT ADVISORY CRITERIA. && .HYDROLOGY... ISSUED AT 330 AM EST FRI FEB 17 2012 NO SIGNIFICANT PRECIPITATION IS FORECASTED THROUGH THE WEEKEND INTO EARLY NEXT WEEK. RIVER LEVELS ARE NOT FORECASTED TO RISE SIGNIFICANTLY THROUGH THEN. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...MJS SHORT TERM...LAURENS LONG TERM....WDM AVIATION...MJS MARINE...LAURENS HYDROLOGY...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1245 PM EST FRI FEB 17 2012 .UPDATE... ISSUED AT 1144 AM EST FRI FEB 17 2012 ANOTHER UPDATE AS SNOW OVER WESTERN LK SUPERIOR IS HOLDING ITS OWN WHILE SLIDING INTO THE AREA. OTHER AREA OF LGT SNOW OVER KEWEENAW THAT IS MORE TIED TO CONVERGENCE WITH SFC TROUGH IS BEGINNING TO DROP SE INTO NCNTRL UPR MI. MOST AREAS OVR WEST HALF OF UPR MI WILL SEE LGT SNOW THROUGH REST OF AFTN. INCREASED POPS TO CATEGORICAL. A HIGH POP/LOW QPF SETUP. BASED ON UPSTREAM REPORTS AND REPORT FM KEWEENAW EARLIER...EXPECT MOST AREAS TO SEE ADDITIONAL AMOUNTS UP TO A HALF INCH OF SNOW WITH ISOLD AMOUNTS OVR 1 INCH POSSIBLE. STEADIER LGT SNOW WILL SHIFT INTO SCNTRL UPR MI...VCNTY OF IMT TO ESC TO MNM BY EARLY EVENING...THEN DEPART THAT AREA BY LATE EVENING. MAY SEE ADDITIONAL AMOUNTS UP TO 1 INCH THIS EVENING OVR SCNTRL. LK EFFECT BEGINS TO DEVELOP BY LATE EVENING/OVERNIGHT CLOSER TO LK SUPERIOR AS THE SYSTEM SNOW DEPARTS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 437 AM EST FRI FEB 17 2012 WV SATELLITE AND RUC ANALYSIS SHOWING UPPER TROUGH CURRENTLY OVER THE NCNTRL CONUS...WITH A COUPLE SHORTWAVES EMBEDDED WITHIN THE FLOW. SHORTWAVE IN WRN MN IS AIDING A WEAK SFC LOW THAT HAS DEVELOPED ALONG A SFC TROUGH EXTENDING FROM A MUCH STRONGER LOW LOCATED OVER WRN ONTARIO. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES AROUND -8.5C OVER THE ERN LK...WHICH HAS DIMINISHED MUCH OF THE LES DURING THE OVERNIGHT HOURS. FARTHER TO THE W...THERE ARE A FEW SNOW SHOWERS THAT HAVE DEVELOPED OVER THE NW CWA UNDER BROAD/WEAK H925-700 WAA. FINALLY...MORE NUMEROUS -SHSN ARE SEEN W OF A LINE FROM KELO TO KDLH ASSOCIATED WITH STRONGER H850-700 WAA/FGEN AND DEEPER MOISTURE. TODAY...THE SHORTWAVE WILL TRACK ESE THROUGH THE DAY AND KEEP THE MAIN WEAK LOW TRACKING TO THE S OF THE CWA AND THROUGH CNTRL WI. ON A BROAD SCALE...BEST H850-700 Q-VECTOR CONV...WAA...AND MOISTURE IS FOCUSED/TRACKS TO THE S OF THE CWA...FOLLOWING THE SHORTWAVE AND SFC LOW. BUT A RIBBON OF DEEPER MOISTURE JUST WNW OF KDLH AND PRODUCING THE SHOWERS WILL BE THE FIRST TO INFLUENCE THE AREA TODAY. H800-750 FGEN LINES UP WELL THE THE ONGOING -SHSN AND SHOULD START TO SLIDE INTO THE WRN CWA BETWEEN 12-15Z AND THEN INTO THE CNTRL BETWEEN 15-18Z. BUT AS IT MOVES E...THE FGEN/WAA BEGINS TO FOCUS FARTHER S/W CLOSER TO THE SFC LOW AND SHORTWAVE. THE NEXT WAVE OF H900-800 FGEN/WAA LOOKS TO PUSH OVER THE AREA HEADING INTO THE AFTN AND BRING THE BETTER CHANCE OF MORE WIDESPREAD LIGHT/MOD SNOW. 00Z NAM IS MORE PRONOUNCED ON THIS FGEN THAN THE 18Z GFS...BUT THE 00Z GFS HAS FOLLOWED SUIT AND LEADS TO HIGHER CONFIDENCE. IN ADDITION...00Z NAM/GFS BOTH SHOWING FAIRLY STRONG H850 OMEGA OVER THE SRN HALF OF THE CWA IN THE AFTN. ALL OF THIS COMBINED MADE ME FEEL CONFIDENT ON BUMPING POPS UP FROM THE GOING LOW CHANCES TO HIGH END CHANCES AND POCKETS OF LIKELY VALUES. SNOW AMNTS ARE TRICKY AS HEAVIEST ACCUMS WILL OCCUR WHERE THE BEST FGEN OCCURS AND IT APPEARS TO BE A FAIRLY NARROW CORRIDOR. SNOW RATIOS SHOULD START OUT IN THE 15/16-1 RANGE INITIALLY WITH THE HIGHER FORCING CLOSER TO THE DGZ...BUT DROP TO AROUND 13-1 DURING THE MAIN SNOW THIS AFTN...DUE TO BEST FGEN FORCING LOCATED BELOW THE DGZ AND WITH LLVL TEMPS ARE SLIGHTLY ABOVE FREEZING. WETBULB ZERO VALUES STAY BELOW 700FT SO EXPECT PCPN TO STAY AS ALL SNOW OVER THE SCNTRL CWA. OVERALL...EXPECT AREAS S OF A TWIN LAKES...TO GWINN...TO ESCANABA TO SEE A DUSTING TO AN INCH OF SNOW. BUT COULD BE SOME LOCALIZED 1.5-2IN AMOUNTS WHERE THE W-E ALIGNED BAND SETS UP. LATEST 06Z NAM RUN HAS SHIFTED THIS HEAVIER BAND SLIGHTLY FARTHER S...FROM KIMT THROUGH MENOMINEE COUNTY...SO SNOW AMNTS MAY NEED TO BE TWEAKED BASED OFF TRENDS THIS MORNING WITH LATEST RUNS. ALSO...THERE ARE SOME HINTS OF WEAK UPSLOPE/LK ENHANCED PCPN AIDING AMNTS OVER THE HIGHER TERRAIN OF MARQUETTE COUNTY...BUT WITH LIMITED COLD AIR CURRENTLY IN PLACE OVER THE LK...NOT TO CONFIDENT ON IT HELPING TOTALS TOO MUCH. TONIGHT...SHOULD SEE DIMINISHING TREND FROM W TO E DURING THE LATE AFTN AND INTO THE EVENING AS THE FGEN/MOISTURE SLIDES E AHEAD OF THE NEXT SHORTWAVE. STRONGER SHORTWAVE WILL BE DIVING S ACROSS THE UPPER GREAT LKS REGION LATE THIS EVENING AND OVERNIGHT. FOLLOWED 00Z GFS/NAM SOLN AS PREFERRED BY HPC THAT IS SLIGHTLY SLOWER AND DIVES THE WAVE ACROSS WRN/CNTRL UPPER MI. EVEN THOUGH THE SHORTWAVE LOOKS TO BE FAIRLY POTENT...MOISTURE LOOKS TO BE OF CONCERN AS MUCH OF THE DEEPER MOISTURE PULLS OUT OF THE AREA WITH THE FIRST WAVE. THIS LEAVES LIMITED CONFIDENCE IN SYNOPTIC PCPN OCCURRING. ATTENTION THEN TURNS TO LES POTENTIAL. H850 TEMPS FALLING FROM AROUND -10C AT 00Z SAT TO AROUND -14 TO -15C BY 12Z SAT WILL INCREASE THE LK INDUCED INSTABILITY. WITH LIMITED INSTABILITY/MOISTURE TO START THE EVENING...HAVE TRIMMED BACK POPS OVER THE NW U.P. SHORELINES AT THE START OF THE PERIOD. WITH THE COLDER TEMPS ARRIVING AND SHORTWAVE ENERGY PUSHING THROUGH LATE THIS EVENING AND OVERNIGHT...EXPECT LES CHANCES TO INCREASE THROUGH THE NIGHT. WINDS ARE STILL A LITTLE TRICKY SINCE HIGH RES RUNS ARE STILL HINTING AT SOME LK INDUCED TROUGHING...BUT EXPECT THE BEST CHANCES OVER THE N TO NNW WIND FAVORED LOCATIONS. WITH INVERSION HEIGHTS AROUND 5-6KFT THERE COULD BE SOME STRONGER BANDS...BUT SOME LIMITING FACTORS EXIST. FIRST...ALTHOUGH TEMPS ARE COOLING...MODELS SHOWING MUCH OF THE OMEGA OCCURRING BELOW THE DGZ...WHICH SHOULD KEEP SNOW RATIOS ON THE LOW SIDE. ONE EXCEPTION WOULD BE OVER THE KEWEENAW...WHERE THE COLDEST TEMPS ARE AND SHOULD PLACE FORCING MORE IN THE DGZ. SECOND...WITH THE SHORTWAVE MOVING THROUGH...MODELS ARE SHOWING SOME DIRECTIONAL SHEAR BETWEEN THE SFC AND H850. THUS...KEPT LES AMNTS UNDER AN INCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 437 AM EST FRI FEB 17 2012 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE GREAT LAKES REGION INTO THE NORTHERN PLAINS WITH A CLOSED LOW OVER THE GULF OF CA AND A RIDGE IS OFF THE WEST COAST. THE TROUGH OVER THE GREAT LAKES REGION WILL GET AMPLIFIED AS A SHORTWAVE DIGS SOUTHEAST INTO THE AREA TONIGHT WITH A SHORTWAVE RIDGE BUILDING INTO THE AREA SAT NIGHT INTO SUNDAY. LAKE EFFECT WILL CONTINUE TO BE GOING ON SATURDAY MORNING BEFORE THE ENVIRONMENT GETS A BIT MORE HOSTILE TO LAKE EFFECT. GFS BUFKIT SOUNDINGS SHOW AN INVERTED-V SOUNDING IN THE LOW LEVELS AT IWD...CMX AND ERY AND INVERSION HEIGHTS FALL IN THE MORNING FROM 3000-4000 FEET. DGZ ALSO FALLS IN HEIGHT AND DEEPER MOISTURE DEPARTS AS DRY AIR COMES IN. OMEGA IN THE DGZ ALSO BECOMES NEGATIVE WITH DOWNWARD MOTION AT THAT TIME SO THE LIKELY POPS IN THE MORNING IN NORTH AFFECT LAKE SUPERIOR LAKE EFFECT SNOW BELTS WILL DECREASE TO CHANCE IN THE AFTERNOON AS THE WINDS BACK MORE TOWARDS THE WEST. WINDS GO WEST TO SOUTHWEST SAT NIGHT SO ANY LINGERING LAKE EFFECT IN THE NORTH WILL PUSH OFFSHORE AND IN THE EAST WILL CONTINUE TO DIMINISH. WITH THE LIGHT SW WINDS ON LAND...TEMPERATURES WILL GET COLD AS IDEAL RADIATIONAL COOLING SETS UP WITH CLEAR SKIES AND LIGHT WINDS. WENT COLDER WITH TEMPERATURES THAN THE GOING FORECAST AND WENT WITH ADJMAV GUIDANCE WHICH LOOKED REASONABLE. SUNDAY AND SUNDAY NIGHT LOOK DRY AND THIS CARRIES INTO MONDAY AS WELL. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO LOWER LOW TEMPERATURES FOR SATURDAY NIGHT. IN THE EXTENDED...ECMWF SHOWS A 500 MB TROUGH THAT WILL MOVE INTO THE PLAINS ON MONDAY WITH SPLIT FLOW COMBINING TO FORM A DEEP TROUGH MOVING INTO THE UPPER GREAT LAKES LATE TUE THAT PUSHES THROUGH WITH MORE ENERGY DIGGING INTO THE GREAT LAKES WED NIGHT INTO THU. TEMPERATURES LOOK TO STAY MILD THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL. SYSTEM SNOW FOR MON NIGHT AND TUE. THERE IS A HINT OF SOME LAKE EFFECT FOR THE REST OF THE PERIOD WITH THE GFS SHOWING SOME COLDER AIR COMING IN. THE ECMWF DOES NOT HAVE THE COLDER AIR COMING IN SO NO LAKE EFFECT. AVERAGING THIS OUT WOULD GIVE SLIGHT CHANCE POPS AND THAT IS WHAT WILL BE FORECASTED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1240 PM EST FRI FEB 17 2012 AREA OF SNOW THAT WAS OVER KEWEENAW MUCH OF THE MORNING ALONG A WEAK LOW PRESSURE TROUGH WILL SLOWLY DROP SOUTH INTO KIWD AND KSAW TERMINALS THROUGH THE AFTN. EXPECT MAINLY MVFR CONDITIONS AT THESE LOCATIONS...THOUGH VERY BRIEF LOWERING TO IFR VSBY IS POSSIBLE /THROUGH 21Z AT KIWD AND BTWN 21Z-01Z AT KSAW/. MEANWHILE... CONDITIONS WILL PROBABLY TRY TO BECOME VFR AT KCMX FOR THE REST OF THE DAY AS DRIER AIR WORKS IN FM THE NORTH. BY EARLY EVENING...EXPECT VFR CONDITIONS FOR ALL SITES AS TROUGH SETTLES SOUTH OF UPR MI. LK EFFECT SNOW SHOWERS WITH MVFR CONDITIONS SHOULD DEVELOP LATER TONIGHT INTO SATURDAY AT ALL THE TAF SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 437 AM EST FRI FEB 17 2012 NO GALES ARE EXPECTED THROUGH THE PERIOD. THE STRONGEST WINDS THROUGH MID WEEK NEXT WEEK WILL OCCUR THIS MORNING AS NORTHWEST WINDS GUST TO AROUND 30 KTS ON THE PERIPHERY OF A LOW MOVING ACROSS ONTARIO. WITH WARMER TEMPERATURES AND LIGHTER WINDS...FREEZING SPRAY SHOULD NOT BE A PROBLEM EITHER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...SRF LONG TERM...07 AVIATION...JLA MARINE...07
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1146 AM EST FRI FEB 17 2012 .UPDATE... ISSUED AT 1144 AM EST FRI FEB 17 2012 ANOTHER UPDATE AS SNOW OVER WESTERN LK SUPERIOR IS HOLDING ITS OWN WHILE SLIDING INTO THE AREA. OTHER AREA OF LGT SNOW OVER KEWEENAW THAT IS MORE TIED TO CONVERGENCE WITH SFC TROUGH IS BEGINNING TO DROP SE INTO NCNTRL UPR MI. MOST AREAS OVR WEST HALF OF UPR MI WILL SEE LGT SNOW THROUGH REST OF AFTN. INCREASED POPS TO CATEGORICAL. A HIGH POP/LOW QPF SETUP. BASED ON UPSTREAM REPORTS AND REPORT FM KEWEENAW EARLIER...EXPECT MOST AREAS TO SEE ADDITIONAL AMOUNTS UP TO A HALF INCH OF SNOW WITH ISOLD AMOUNTS OVR 1 INCH POSSIBLE. STEADIER LGT SNOW WILL SHIFT INTO SCNTRL UPR MI...VCNTY OF IMT TO ESC TO MNM BY EARLY EVENING...THEN DEPART THAT AREA BY LATE EVENING. MAY SEE ADDITIONAL AMOUNTS UP TO 1 INCH THIS EVENING OVR SCNTRL. LK EFFECT BEGINS TO DEVELOP BY LATE EVENING/OVERNIGHT CLOSER TO LK SUPERIOR AS THE SYSTEM SNOW DEPARTS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 437 AM EST FRI FEB 17 2012 WV SATELLITE AND RUC ANALYSIS SHOWING UPPER TROUGH CURRENTLY OVER THE NCNTRL CONUS...WITH A COUPLE SHORTWAVES EMBEDDED WITHIN THE FLOW. SHORTWAVE IN WRN MN IS AIDING A WEAK SFC LOW THAT HAS DEVELOPED ALONG A SFC TROUGH EXTENDING FROM A MUCH STRONGER LOW LOCATED OVER WRN ONTARIO. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES AROUND -8.5C OVER THE ERN LK...WHICH HAS DIMINISHED MUCH OF THE LES DURING THE OVERNIGHT HOURS. FARTHER TO THE W...THERE ARE A FEW SNOW SHOWERS THAT HAVE DEVELOPED OVER THE NW CWA UNDER BROAD/WEAK H925-700 WAA. FINALLY...MORE NUMEROUS -SHSN ARE SEEN W OF A LINE FROM KELO TO KDLH ASSOCIATED WITH STRONGER H850-700 WAA/FGEN AND DEEPER MOISTURE. TODAY...THE SHORTWAVE WILL TRACK ESE THROUGH THE DAY AND KEEP THE MAIN WEAK LOW TRACKING TO THE S OF THE CWA AND THROUGH CNTRL WI. ON A BROAD SCALE...BEST H850-700 Q-VECTOR CONV...WAA...AND MOISTURE IS FOCUSED/TRACKS TO THE S OF THE CWA...FOLLOWING THE SHORTWAVE AND SFC LOW. BUT A RIBBON OF DEEPER MOISTURE JUST WNW OF KDLH AND PRODUCING THE SHOWERS WILL BE THE FIRST TO INFLUENCE THE AREA TODAY. H800-750 FGEN LINES UP WELL THE THE ONGOING -SHSN AND SHOULD START TO SLIDE INTO THE WRN CWA BETWEEN 12-15Z AND THEN INTO THE CNTRL BETWEEN 15-18Z. BUT AS IT MOVES E...THE FGEN/WAA BEGINS TO FOCUS FARTHER S/W CLOSER TO THE SFC LOW AND SHORTWAVE. THE NEXT WAVE OF H900-800 FGEN/WAA LOOKS TO PUSH OVER THE AREA HEADING INTO THE AFTN AND BRING THE BETTER CHANCE OF MORE WIDESPREAD LIGHT/MOD SNOW. 00Z NAM IS MORE PRONOUNCED ON THIS FGEN THAN THE 18Z GFS...BUT THE 00Z GFS HAS FOLLOWED SUIT AND LEADS TO HIGHER CONFIDENCE. IN ADDITION...00Z NAM/GFS BOTH SHOWING FAIRLY STRONG H850 OMEGA OVER THE SRN HALF OF THE CWA IN THE AFTN. ALL OF THIS COMBINED MADE ME FEEL CONFIDENT ON BUMPING POPS UP FROM THE GOING LOW CHANCES TO HIGH END CHANCES AND POCKETS OF LIKELY VALUES. SNOW AMNTS ARE TRICKY AS HEAVIEST ACCUMS WILL OCCUR WHERE THE BEST FGEN OCCURS AND IT APPEARS TO BE A FAIRLY NARROW CORRIDOR. SNOW RATIOS SHOULD START OUT IN THE 15/16-1 RANGE INITIALLY WITH THE HIGHER FORCING CLOSER TO THE DGZ...BUT DROP TO AROUND 13-1 DURING THE MAIN SNOW THIS AFTN...DUE TO BEST FGEN FORCING LOCATED BELOW THE DGZ AND WITH LLVL TEMPS ARE SLIGHTLY ABOVE FREEZING. WETBULB ZERO VALUES STAY BELOW 700FT SO EXPECT PCPN TO STAY AS ALL SNOW OVER THE SCNTRL CWA. OVERALL...EXPECT AREAS S OF A TWIN LAKES...TO GWINN...TO ESCANABA TO SEE A DUSTING TO AN INCH OF SNOW. BUT COULD BE SOME LOCALIZED 1.5-2IN AMOUNTS WHERE THE W-E ALIGNED BAND SETS UP. LATEST 06Z NAM RUN HAS SHIFTED THIS HEAVIER BAND SLIGHTLY FARTHER S...FROM KIMT THROUGH MENOMINEE COUNTY...SO SNOW AMNTS MAY NEED TO BE TWEAKED BASED OFF TRENDS THIS MORNING WITH LATEST RUNS. ALSO...THERE ARE SOME HINTS OF WEAK UPSLOPE/LK ENHANCED PCPN AIDING AMNTS OVER THE HIGHER TERRAIN OF MARQUETTE COUNTY...BUT WITH LIMITED COLD AIR CURRENTLY IN PLACE OVER THE LK...NOT TO CONFIDENT ON IT HELPING TOTALS TOO MUCH. TONIGHT...SHOULD SEE DIMINISHING TREND FROM W TO E DURING THE LATE AFTN AND INTO THE EVENING AS THE FGEN/MOISTURE SLIDES E AHEAD OF THE NEXT SHORTWAVE. STRONGER SHORTWAVE WILL BE DIVING S ACROSS THE UPPER GREAT LKS REGION LATE THIS EVENING AND OVERNIGHT. FOLLOWED 00Z GFS/NAM SOLN AS PREFERRED BY HPC THAT IS SLIGHTLY SLOWER AND DIVES THE WAVE ACROSS WRN/CNTRL UPPER MI. EVEN THOUGH THE SHORTWAVE LOOKS TO BE FAIRLY POTENT...MOISTURE LOOKS TO BE OF CONCERN AS MUCH OF THE DEEPER MOISTURE PULLS OUT OF THE AREA WITH THE FIRST WAVE. THIS LEAVES LIMITED CONFIDENCE IN SYNOPTIC PCPN OCCURRING. ATTENTION THEN TURNS TO LES POTENTIAL. H850 TEMPS FALLING FROM AROUND -10C AT 00Z SAT TO AROUND -14 TO -15C BY 12Z SAT WILL INCREASE THE LK INDUCED INSTABILITY. WITH LIMITED INSTABILITY/MOISTURE TO START THE EVENING...HAVE TRIMMED BACK POPS OVER THE NW U.P. SHORELINES AT THE START OF THE PERIOD. WITH THE COLDER TEMPS ARRIVING AND SHORTWAVE ENERGY PUSHING THROUGH LATE THIS EVENING AND OVERNIGHT...EXPECT LES CHANCES TO INCREASE THROUGH THE NIGHT. WINDS ARE STILL A LITTLE TRICKY SINCE HIGH RES RUNS ARE STILL HINTING AT SOME LK INDUCED TROUGHING...BUT EXPECT THE BEST CHANCES OVER THE N TO NNW WIND FAVORED LOCATIONS. WITH INVERSION HEIGHTS AROUND 5-6KFT THERE COULD BE SOME STRONGER BANDS...BUT SOME LIMITING FACTORS EXIST. FIRST...ALTHOUGH TEMPS ARE COOLING...MODELS SHOWING MUCH OF THE OMEGA OCCURRING BELOW THE DGZ...WHICH SHOULD KEEP SNOW RATIOS ON THE LOW SIDE. ONE EXCEPTION WOULD BE OVER THE KEWEENAW...WHERE THE COLDEST TEMPS ARE AND SHOULD PLACE FORCING MORE IN THE DGZ. SECOND...WITH THE SHORTWAVE MOVING THROUGH...MODELS ARE SHOWING SOME DIRECTIONAL SHEAR BETWEEN THE SFC AND H850. THUS...KEPT LES AMNTS UNDER AN INCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 437 AM EST FRI FEB 17 2012 UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE GREAT LAKES REGION INTO THE NORTHERN PLAINS WITH A CLOSED LOW OVER THE GULF OF CA AND A RIDGE IS OFF THE WEST COAST. THE TROUGH OVER THE GREAT LAKES REGION WILL GET AMPLIFIED AS A SHORTWAVE DIGS SOUTHEAST INTO THE AREA TONIGHT WITH A SHORTWAVE RIDGE BUILDING INTO THE AREA SAT NIGHT INTO SUNDAY. LAKE EFFECT WILL CONTINUE TO BE GOING ON SATURDAY MORNING BEFORE THE ENVIRONMENT GETS A BIT MORE HOSTILE TO LAKE EFFECT. GFS BUFKIT SOUNDINGS SHOW AN INVERTED-V SOUNDING IN THE LOW LEVELS AT IWD...CMX AND ERY AND INVERSION HEIGHTS FALL IN THE MORNING FROM 3000-4000 FEET. DGZ ALSO FALLS IN HEIGHT AND DEEPER MOISTURE DEPARTS AS DRY AIR COMES IN. OMEGA IN THE DGZ ALSO BECOMES NEGATIVE WITH DOWNWARD MOTION AT THAT TIME SO THE LIKELY POPS IN THE MORNING IN NORTH AFFECT LAKE SUPERIOR LAKE EFFECT SNOW BELTS WILL DECREASE TO CHANCE IN THE AFTERNOON AS THE WINDS BACK MORE TOWARDS THE WEST. WINDS GO WEST TO SOUTHWEST SAT NIGHT SO ANY LINGERING LAKE EFFECT IN THE NORTH WILL PUSH OFFSHORE AND IN THE EAST WILL CONTINUE TO DIMINISH. WITH THE LIGHT SW WINDS ON LAND...TEMPERATURES WILL GET COLD AS IDEAL RADIATIONAL COOLING SETS UP WITH CLEAR SKIES AND LIGHT WINDS. WENT COLDER WITH TEMPERATURES THAN THE GOING FORECAST AND WENT WITH ADJMAV GUIDANCE WHICH LOOKED REASONABLE. SUNDAY AND SUNDAY NIGHT LOOK DRY AND THIS CARRIES INTO MONDAY AS WELL. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT TO LOWER LOW TEMPERATURES FOR SATURDAY NIGHT. IN THE EXTENDED...ECMWF SHOWS A 500 MB TROUGH THAT WILL MOVE INTO THE PLAINS ON MONDAY WITH SPLIT FLOW COMBINING TO FORM A DEEP TROUGH MOVING INTO THE UPPER GREAT LAKES LATE TUE THAT PUSHES THROUGH WITH MORE ENERGY DIGGING INTO THE GREAT LAKES WED NIGHT INTO THU. TEMPERATURES LOOK TO STAY MILD THROUGH THE PERIOD WITH TEMPERATURES ABOVE NORMAL. SYSTEM SNOW FOR MON NIGHT AND TUE. THERE IS A HINT OF SOME LAKE EFFECT FOR THE REST OF THE PERIOD WITH THE GFS SHOWING SOME COLDER AIR COMING IN. THE ECMWF DOES NOT HAVE THE COLDER AIR COMING IN SO NO LAKE EFFECT. AVERAGING THIS OUT WOULD GIVE SLIGHT CHANCE POPS AND THAT IS WHAT WILL BE FORECASTED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 629 AM EST FRI FEB 17 2012 A DISTURBANCE MOVING THROUGH WI TODAY WILL SPREAD SNOW ACROSS MAINLY THE SOUTHERN 2/3RDS OF UPPER MI TODAY. BEST SHOT FOR SNOW AND LOWER VSBYS WILL BE AT KIWD...BUT STILL SOME UNCERTAINTY ON IF THE HEAVIEST SNOW WILL BE S OF THE TAF SITE. KCMX WILL LIKELY BE AT MVFR CIGS THROUGH MUCH OF THE DAY AS THE FRONT SAGS SOUTH...WHILE KIWD/KSAW WILL HAVE TO WAIT UNTIL THE -SHSN START. TRIED TO SHOW A BREAK IN LOWER CIGS BEHIND THE DISTURBANCE AND DEVELOPING LES...BUT LIGHT UPSLOPE NORTHERLY FLOW COULD LEAD TO THE SCT CLOUDS BECOMING BKN. KIWD/KCMX WILL SEE LOWEST VSBYS AFTER MIDNIGHT...AS LAKE EFFECT SNOW DEVELOPS UNDER NNW FLOW. THIS LES COULD AFFECT KSAW LATE IN THE TAF PERIOD AND ONLY MADE SLIGHT VSBY REDUCTION DUE TO UNCERTAINTY OF A FAVORABLE WIND DIRECTION. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 437 AM EST FRI FEB 17 2012 NO GALES ARE EXPECTED THROUGH THE PERIOD. THE STRONGEST WINDS THROUGH MID WEEK NEXT WEEK WILL OCCUR THIS MORNING AS NORTHWEST WINDS GUST TO AROUND 30 KTS ON THE PERIPHERY OF A LOW MOVING ACROSS ONTARIO. WITH WARMER TEMPERATURES AND LIGHTER WINDS...FREEZING SPRAY SHOULD NOT BE A PROBLEM EITHER. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...JLA SHORT TERM...SRF LONG TERM...07 AVIATION...SRF MARINE...07
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1144 AM CST FRI FEB 17 2012 .AVIATION... SHOWERS CURRENTLY DETECTED ON KAMA 88D CONTINUE TO MOVE NORTHEAST AT AROUND 30 KT. THESE SHOWERS WILL MOST LIKELY AFFECT KAMA IN THE VERY NEAR TERM...WITH POTENTIAL FOR INCREASED DEVELOPMENT NEAR NORTHERN TERMINALS DURING LATE AFTERNOON AND EARLY EVENING...DUE TO ENHANCED CONVERGENCE AND HIGHER INSTABILITY. DO NOT EXPECT THUNDER NEXT 24 HOURS. VFR CEILINGS EXPECTED TO PREVAIL THROUGH MOST OF THE AFTERNOON. MVFR CEILINGS DEVELOP BEFORE 00Z SATURDAY AT KAMA AND KDHT...AND AROUND 03Z SATURDAY AT KGUY. FURTHER DETERIORATION EXPECTED OVERNIGHT...WITH IFR CEILINGS AND VISIBILITIES DEVELOPING AT ALL TAF SITES THIS EVENING. COLD FRONT STILL EXPECTED TO PASS THROUGH TERMINALS BETWEEN 06Z AND 08Z SATURDAY...WITH SURFACE WINDS SHIFTING TO THE NORTH. DRIER AIR FOLLOWS FRONTAL PASSAGE...WITH IMPROVEMENT BEGINNING AFTER 15Z SATURDAY. COCKRELL && .PREV DISCUSSION... /ISSUED 735 AM CST FRI FEB 17 2012/ UPDATE... ADDED SLIGHT CHANCE OF SNOW SHOWERS BETWEEN 9 AM AND NOON CST TODAY ON THE CAPROCK MAINLY ALONG AND SOUTH OF I-40 INCLUDING AMARILLO... CANYON...HEREFORD...VEGA...PANHANDLE...CLAUDE...AND PAMPA. DISCUSSION... LIGHT PRECIPITATION...MAINLY IN THE FORM OF LIGHT RAIN...CONTINUES TO MOVE NORTHEAST AND INTO THE SOUTH TEXAS PANHANDLE THIS MORNING. MADE THE ADJUSTMENTS ABOVE AS LATEST KLBB RADAR INDICATED BRIGHT BANDING AS LOW AS 600 FT AGL JUST NORTHWEST OF LUBBOCK. APPEARS THIS HEAVIER ACTIVITY MAY COOL THE LOWEST 5000 FT OF THE ATMOSPHERE ENOUGH TO ALLOW FOR LIGHT SNOW TO MIX WITH THE LIGHT RAIN ACROSS THE SOUTH CENTRAL AND SOUTHWEST TEXAS PANHANDLES BETWEEN 9 AM AND NOON CST INCLUDING AMARILLO. WITH WARM SURFACE TEMPERATURES ABOVE FREEZING/32 DEGREES...IF ANY SNOW OCCURS...NO ACCUMULATIONS ARE EXPECTED. STILL BELIEVE LIGHT RAIN WILL BE THE PREDOMINANT PRECIPITATION TYPE THIS MORNING. SOME MID/UPPER DRY SLOTTING MOVING INTO THE PANHANDLES MAY LIMIT PRECIPITATION CHANCES THIS AFTERNOON. BY MIDDAY TODAY...SURFACE TEMPERATURES WILL LIKELY BE TOO WARM TO SUPPORT ANYTHING BUT LIGHT RAIN. PRODUCTS HAVE BEEN UPDATED. MBS PREV DISCUSSION... /ISSUED 557 AM CST FRI FEB 17 2012/ AVIATION... FOR THE 12Z TAFS...THERE IS QUITE A BIT OF UNCERTAINTY WITH RESPECT TO PRECIPITATION TIMING AND FLIGHT CATEGORIES. AT KAMA...EXPECT MVFR CONDITIONS 13-16Z AS -RA IMPACTS THE TAF SITE. AFTERWARD...VFR MAY PREDOMINANTLY PREVAIL THROUGH 23Z...BUT CONFIDENCE IS LOW. AFTER 23Z...HAVE MODERATE CONFIDENCE THAT MVFR CONDITIONS WILL DEVELOP...DETERIORATING TO IFR AFTER 03Z. AFTER 08Z...LIFR OR VLIFR CONDITIONS WILL BE POSSIBLE...BUT CONFIDENCE IN THIS IS CURRENTLY TOO LOW TO MENTION. AT KDHT...HAVE MODERATE CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL THROUGH 20Z WHEN MVFR CIGS DEVELOP. HAVE MODERATE TO HIGH CONFIDENCE THAT CIGS/VSBYS WILL DETERIORATE INTO IFR CATEGORY AFTER 03Z AND POSSIBLY LIFR/VLIFR AFTER 08Z. HOWEVER...CONFIDENCE IS LOW WHETHER LIFR/VLIFR CONDITIONS WILL DEVELOP. AT KGUY...HAVE MODERATE CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL THROUGH 21Z...BUT THERE IS A POSSIBILITY THAT MVFR CONDITIONS MAY DEVELOP AFTER 21Z. HAVE MODERATE CONFIDENCE THAT MVFR CONDITIONS WILL DEVELOP BY 03Z AND DETERIORATING TO IFR CONDITIONS AFTER 06Z. IT/S POSSIBLE THAT LIFR CONDITIONS COULD DEVELOP AFTER 06Z...BUT CONFIDENCE IN THIS IS LOW. -RA IS EXPECTED AT ALL TAF SITES THROUGH THIS PERIOD...BUT TIMING THE ONSET AND ENDING TIMES AT THIS POINT IS NEARLY IMPOSSIBLE. AMENDMENTS WILL BE NEEDED. IT/S POSSIBLE THERE COULD BE A -RASN MIX AT KDHT AFTER 09Z...BUT CONFIDENCE IS TOO LOW TO MENTION AT THIS TIME. A COLD FRONT WILL MOVE THROUGH ALL SITES 06-08Z WITH WINDS SHIFTING TO THE NORTH. JACKSON PREV DISCUSSION... /ISSUED 448 AM CST FRI FEB 17 2012/ DISCUSSION... PRECIPITATION CHANCES AND TYPES TODAY THROUGH SATURDAY MORNING ARE THE MAIN FORECAST CHALLENGES. LATEST MODELS WERE IN FAIR TO GOOD AGREEMENT. USED A BLEND WITH A PREFERENCE TOWARDS THE 00Z ECMWF DUE TO IT/S BETTER HANDLING OF MOISTURE AND QPF FIELDS. THE BIGGEST CHANGE TO THE PREVIOUS FORECAST WAS TO LOWER PRECIPITATION CHANCES TODAY ACROSS THE NORTH TEXAS AND OKLAHOMA PANHANDLES. AT 445 AM CST ACROSS THE PANHANDLES...MOSTLY CLOUDY CONDITIONS WERE OCCURRING WITH SURFACE TEMPERATURES MAINLY IN THE 30S. LIGHT RAIN SHOWERS WERE NEAR I-40 EAST OF AMARILLO AND AN AREA OF RAIN SHOWERS WERE JUST SOUTH OF A HEREFORD TO CLOVIS LINE. A MID/UPPER LOW WAS WELL SOUTH OF ARIZONA. THIS MORNING...KEPT THE HIGHEST RAIN CHANCES OVER THE SOUTH TEXAS PANHANDLE...GENERALLY 60 TO 90 PERCENT...THINKING CURRENT AREA OF RAIN SHOWERS MENTIONED ABOVE WILL HOLD TOGETHER. THE 00Z ECMWF DID BEST DEPICTING THIS AREA WITH ITS MOISTURE/QPF FIELDS. DOUBT MUCH...IF ANY RAINFALL...WILL OCCUR NORTH OF A CHANNING TO LIPSCOMB LINE. LATEST RUC13 AND WARM LOW LEVEL THERMAL FIELDS SUGGESTED THAT MOST...IF NOT ALL...OF THE PRECIPITATION WILL BE IN THE FORM OF LIGHT RAIN. RAINFALL AMOUNTS ARE EXPECTED TO RANGE FROM ZERO IN THE OKLAHOMA PANHANDLE UP TO 0.25 INCH SOUTH OF I-40. THERE IS A LITTLE CONCERN THAT THE PRECIPITATION COULD MIX WITH OR BRIEFLY TURN OVER TO LIGHT SNOW AND BRING A QUICK WET INCH OF SNOWFALL WEST OF I-27 AND SOUTH OF I-40 NEAR HEREFORD THIS MORNING...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE QUITE LOW...ESPECIALLY WITH CURRENT SURFACE WET BULB TEMPERATURES A FEW DEGREES ABOVE 32F. THIS AFTERNOON...KEPT RAIN CHANCES...20 TO 50 PERCENT ACROSS THE AREA. THERE MAY BE MORE DRY HOURS THAN WET ONES AND APPEARS ANY ADDITIONAL RAINFALL WILL GENERALLY BE LESS THAN 0.10 INCH. LOW LEVEL TEMPERATURES WILL BE WARM ENOUGH TO SUPPORT ALL RAIN. THE WARMER 00Z MAVMOS HIGHS IN THE 40S APPEARED REASONABLE. TONIGHT INTO SATURDAY MORNING...KEPT PRECIPITATION CHANCES 30 TO 50 PERCENT ACROSS THE AREA TONIGHT...THEN 20 TO 30 PERCENT SATURDAY MORNING. APPEARS ANY PRECIPITATION BEFORE MIDNIGHT WILL BE IN THE FORM OF LIGHT RAIN...THEN TURN OVER TO LIGHT SNOW NORTHWEST TO SOUTHEAST. AT THIS TIME...APPEARS ANY SNOWFALL ACCUMULATIONS WILL BE UNDER ONE HALF INCH. THERE IS A LOW CHANCE A BAND OF SNOW MAY DEVELOP NEAR A DALHART TO BEAVER LINE LATE TONIGHT INTO SATURDAY MORNING WHICH COULD BRING LOCALLY ENHANCE SNOWFALL AND BRING ONE TO TWO INCHES TO THESE AREAS...BUT CONFIDENCE OF THIS OCCURRING SEEMS TO BE VERY LOW...ESPECIALLY AS NOT SURE PHASING WILL OCCUR WITH MID/UPPER TROUGHS MOVING OVER THE AREA. IN ADDITION...APPEARS THE BEST MOISTURE WILL BE CUT OFF AND OVER SOUTH TEXAS. WENT CLOSER TO THE WARMER 00Z MAVMOS LOWS. SATURDAY AFTERNOON THROUGH SUNDAY NIGHT...DRY CONDITIONS ARE EXPECTED. CLOUDS WILL BE SLOW TO CLEAR SATURDAY AFTERNOON...SO LOWERED HIGHS CLOSER TO THE COLDER 00Z MAVMOS NUMBERS. THERE IS A LOW CHANCE FOR LIGHT FREEZING FOG SUNDAY MORNING...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. BREEZY AND WARMER CONDITIONS WILL RETURN SUNDAY AFTERNOON UNDER MOSTLY SUNNY SKIES. MONDAY INTO MONDAY NIGHT...WINDY CONDITIONS SEEM LIKELY...ESPECIALLY MONDAY AFTERNOON. MAY BE CLOSE TO ADVISORY LEVEL OF 35 MPH SUSTAINED FOR 3 OR MORE HOURS. KEPT A DRY FORECAST FOR NOW AS APPEARS THE BEST MOISTURE AND LIFT WILL STAY NORTH AND EAST OF THE AREA. WENT NEAR OR ABOVE THE WARMER 00Z MEXMOS HIGHS. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA LATE AFTERNOON AND NIGHT. TUESDAY THROUGH THURSDAY...DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. LATEST MODELS WERE IN SOME DISAGREEMENT WITH SURFACE FEATURES. STAYED CLOSE TO THE 00Z MEXMOS TEMPERATURES. MBS FIRE WEATHER... NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH THIS WEEKEND. ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE MONDAY AFTERNOON ACROSS MUCH OF THE TEXAS PANHANDLE DUE WINDY CONDITIONS AND LOW HUMIDITY. THERE IS A CHANCE CRITICAL FIRE WEATHER CONDITIONS COULD OCCUR MONDAY AFTERNOON IF GROUND MOISTURE DECREASES SUFFICIENTLY AND ALLOWS FOR VERY LOW HUMIDITY VALUES BELOW 10 PERCENT. WINDY TO PERHAPS VERY WINDY WEST TO SOUTHWEST WINDS MAY OCCUR MONDAY AFTERNOON ALONG WITH A WIND SHIFT DUE TO AN APPROACHING COLD FRONT LATE MONDAY AFTERNOON AND NIGHT. MBS && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 03/16
AREA FORECAST DISCUSSION
NWS SPOKANE WA
255 PM PST Fri Feb 17 2012 .SYNOPSIS... A strong weather system will pass through the region tonight and early Saturday resulting in widespread rain and snow to the valleys and snow to the mountains. Snow showers will continue to impact the region through the day Saturday...lingering across the Idaho Panhandle through Sunday afternoon. The active weather pattern is expected to continue through much of the upcoming week. && .DISCUSSION... Tonight: Low pressure continues to spin off the northern tip of Vancouver Island, with an occluded/cold front trailing southward along the Washington and Oregon coastline. Satellite and radar shows this feature steadily moving inland. A swath of precipitation was expanding across western Washington and coming into the Cascades around 22Z (near 2 PM PST). Extrapolation of the shield brings precipitation across the Cascades near 00Z and near the Idaho border toward 05-06Z, with the potential for areas of light precipitation developing ahead of the main swath. The forecast for tonight follows this general trend, meaning a good chance of precipitation in most areas. The duration, however, may not be long in some spots especially once occluded/cold front passage occurs. Extrapolation based on satellite brings the front east of the Cascades between 06-08Z and east of the Washington/Idaho border between 12-14Z. Thus the precipitation should begin to wane overnight in the lee of the Cascades, including areas such as Wenatchee and Moses Lake and toward morning toward the Idaho border with increasing south to southwest winds. Temperatures have been slow to warm over the west and northern portions of the CWA, but there remains good opportunity for warming this evening ahead of the front. Even the most recent guidance, including the 20Z RUC and 18Z NAM, show temperatures warming and accompanying wet-bulb zero heights rising toward 3-5kft across the Moses Lake area, Columbia Basin east into the Spokane/C`da area and Palouse and south into the Blues/L-C Valley. This will mean a threat of rain and snow or perhaps all snow that will have little success in accumulating. The periphery of the CWA will see lower snow levels, near 1-3kft, with a much better chance of accumulating snows. Winter weather highlights remain in place for most of these snows, including the Cascades and northern mountains, and the Wenatchee area through Okanogan Valley. In this latter region, areas below 1500-2500 feet will likely remain on the lower end of advisory amounts. The Idaho Panhandle mountain zones are also under winter weather highlights, starting late tonight. Some of the higher accumulations are expected near the crest of the Cascades and closer to the Canadian border. /J. Cote` Saturday through Monday: The winter storm expected to bring snow and rain to the region this evening and overnight will continue to have a large influence on the weekend weather. The strong frontal occlusion will be just lifting out of Idaho early Saturday morning and the cold core upper-level trough will be in the process of settling into the Inland NW. 500mb temperatures will be cooling near -34C along the WA/ID border to -30C along the Cascades leading to increasing atmospheric instability...and likelihood for snow showers throughout the afternoon and evening across most locations. There are a few features that will impact the order of events. First of all, a midlevel dry slot will be in place roughly 12-18z Saturday which will prevent the ongoing orographic showers for N WA and N ID from producing excessive amounts of QPF/snow due as the brief drying is noted within the heart of the dendritic layer (-10 to -20 celsius). On another note, these showers should persist as strong SW to NE pressure gradients setup across the region bringing gusty winds for most lowlands south of highway 2 and east of the Waterville Plateau. Wind sustained at 15-25 mph with gusts on the order of 30-40 mph will be possible...especially along the typical windy locations within the Blue Mountains and adjacent foothills and lower Columbia Basin, Palouse, and West Plains. This strong upsloping component will continue to fuel the orographic showers despite the drying aloft. As midlevels slowly re-saturate throughout the day, the threat for moderate to heavy mountain snow showers will increase. Snow showers for the valleys will be more hit or miss Saturday afternoon until the remnants of the low pressure system nearing the northern tip of Vancouver Island tracks across the region. Aside from weak differential PVA (positive vorticity advection), there are signs of incr warm advection processes with this feature as the higher theta-e air within its occluded core track through. As a result, the threat for light to locally moderate valley and mtn snows will amp back up Saturday evening through Sunday morning. For several days, the models have shown a track roughly from Seattle to Missoula which favors locations along and north of highway 2 for a secondary light snow event during this time. The forecast has been updated to reflect these changes which will has led to an extension of the winter wx advisories for ID until Saturday afternoon. The storm system will finally clear east of the region Sunday night with a break in the pcpn for most locations. Another wave dropping within the northwesterly jet will bring another shot of light pcpn (mainly snow) for Monday. There is still quite a bit of uncertainty with the strength of this wave and forecast trends were toward the drier SREF/GFS at this time. If skies are able to clear completely Sunday night, we could be looking at very cold temperatures for the northern valleys...however clouds should be on the increase as the next wave of moisture drops into BC and we took a more conservative approach to overnight lows. /sb Monday night through Friday...Models in fair agreement with the overall synoptic scale pattern this period. Longwave ridge is expected to set up along 140w or so and remain there through much of the week. This places the Inland NW under somewhat moist northwest flow. While this pattern isn`t terribly conducive to heavy precipitation...various weak shortwaves passing over the top of the ridge will deliver periods of light precipitation...especially to locations near the Cascade Crest and over the Idaho Panhandle. The air mass associated with this pattern is not very unstable and thus...we should see a well-defined rain shadow in the lee of the Cascades due to persistent westerly mid-level flow over the crest. The pattern could also prove to be a windy one...especially on Wednesday as a strong surface low crosses central portions of British Columbia and Alberta. The 18z GFS solution shows surface winds over the southern Columbia Basin and Washington Palouse of 25-30kt with 850 mb winds ranging from 35-45 kts. If this were to verify...we would certainly need a wind advisory. However the 12z ECMWF and 12z GFS Ensembles don`t paint quite as windy of a picture. Anyway...even if its not quite as windy as the GFS suggests...it will certainly be windier than the weather we have seen for much of this week...which should equate to fairly mild daytime temperatures. Most valleys south of I90 will highs in the 40s through much of the week...with 50s expected over southern portions of the Palouse, Columbia Basin...and Lewiston area. The longwave ridge axis is expected to shift slightly eastward on Friday and then amplify significantly for the following weekend. The change on Friday could be accompanied by a fairly vigorous shortwave trough crossing through the southern half of British Columbia which could deliver a good chance of precipitation to the northern half of our forecast area. Then again there is quite a difference between this solution and the one offered by ECMWF which depicts a much weaker disturbance. By next weekend there is good model consistency that the offshore ridge will amplify into Alaska with deep northerly flow pushing into the western US. 850 mb temps would plunge as a result...with temperatures possibly falling much below the seasonal normals and certainly colder than what we have seen in quite sometime. fx && .AVIATION... 18Z TAFS: IFR/MVFR conditions expected over the north and western TAF sites, with low level moisture being banked up in the east to southeasterly flow ahead of an approaching storm system. This includes the KGEG-KCOE area TAFs and KEAT. Some improvement toward VFR is possible in these areas just ahead and with the incoming front during the late afternoon. Then rain and snow develops from west to east between 00-08z, before decreasing and from west to east between 08-14z. The southeast TAF sites will see a threat of -RASN developing in the same time frame as well with MVFR/LCL IFR conditions. There will be a threat of LLWS around the KGEG-KCOE area this evening, before frontal passage and better mixing. /J. Cote` && .PRELIMINARY POINT TEMPS/POPS... Spokane 33 37 28 37 27 36 / 100 60 60 20 10 30 Coeur d`Alene 31 37 28 36 27 36 / 100 70 70 20 20 30 Pullman 33 39 29 37 28 38 / 100 50 70 30 10 30 Lewiston 36 45 32 43 30 45 / 80 40 40 20 10 20 Colville 30 39 20 38 23 35 / 100 70 70 20 20 30 Sandpoint 30 36 27 36 25 36 / 100 80 70 30 20 30 Kellogg 30 36 27 35 26 35 / 100 90 80 60 20 40 Moses Lake 33 45 26 44 27 41 / 100 20 20 10 10 20 Wenatchee 30 40 27 41 26 38 / 100 30 20 10 10 20 Omak 29 37 19 37 21 37 / 100 70 20 10 10 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory from 10 PM this evening to 10 AM PST Sunday for Central Panhandle Mountains-Northern Panhandle. WA...Winter Weather Advisory until 4 AM PST Saturday for Okanogan Highlands-Okanogan Valley-Waterville Plateau-Wenatchee Area. Winter Weather Advisory until 4 PM PST Saturday for East Slopes Northern Cascades. Winter Storm Warning from 10 PM this evening to 4 PM PST Saturday for Northeast Mountains. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 AM CST FRI FEB 17 2012 .SHORT TERM... 305 AM CST FRI FEB 17 2012 MAIN FORECAST CONCERN IS ON PRECIPITATION CHANCES TODAY. 07Z WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH OVER NORTH DAKOTA. AT THE SURFACE...A WEAK COLD FRONT WAS SITUATED FROM NORTHERN MINNESOTA...BACK INTO EASTERN SOUTH DAKOTA. BAND OF MAINLY MID LEVEL CLOUDS WERE SEEN AHEAD OF IT ACROSS MINNESOTA. 17.00Z MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. SHORTWAVE OVER NORTH DAKOTA WILL ROTATE SOUTHEAST AND ACROSS THE FORECAST AREA TODAY...AS SURFACE COLD FRONT AND WEAK SURFACE LOW PUSHES THROUGH THE AREA. BOTH THE GFS AND NAM SHOWING A SWATH OF QG CONVERGENCE BETWEEN 850MB-500MB ALONG WITH SOME 285K-295K ISENTROPIC LIFT. IN ADDITION...850MB-700MB LAPSE RATES RATHER STEEP 7-9 DEGREES CELSIUS PER KILOMETER BY THIS AFTERNOON. RUC ALSO SHOWING UPWARDS OF 200 J/KG OF 0-3KM MOST UNSTABLE CAPE OVER THE NORTHEASTERN PORTION OF THE FORECAST AREA. THE BIGGEST QUESTION WILL BE DEGREE OF SATURATION. 17.06Z RUC BUFKIT SOUNDINGS SHOWS BEST SATURATION TO THE NORTH OF INTERSTATE 94...WITH AREAS SOUTH OF THERE SATURATION OCCURS ABOVE 900MB. DID RAISE PROBABILITIES A LITTLE ACROSS THE NORTHEAST. WITH MILD PACIFIC AIRMASS IN PLACE AND SURFACE TEMPERATURES EXPECTED INTO THE MIDDLE 30S TO THE LOWER 40S DID MENTION BOTH RAIN AND SNOW SHOWERS. SHORTWAVE EXITS EAST OF THE AREA TONIGHT WITH ONLY SOME LINGERING PRECIPITATION EARLY IN THE EVENING ACROSS THE EASTERN COUNTIES. OTHERWISE...BOTH THE NAM AND GFS INDICATE SOME STRATUS BEHIND THE FONT TO SETTLE OVER THE AREA...MAINLY ACROSS THE NORTHEAST SECTIONS OF THE FORECAST AREA. THESE CLOUDS WILL MOVE OUT RATHER QUICKLY ON SATURDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA. THIS SURFACE HIGH WILL REMAIN OVERHEAD THROUGH SUNDAY WITH CLEAR SKIES...LIGHT WINDS AND SEASONABLE TEMPERATURES. .LONG TERM... 305 AM CST FRI FEB 17 2012 BOTH THE 17.00Z GFS AND ECMWF SHOWING A MORE ACTIVE WEATHER PATTERN DURING THIS TIME FRAME. LONGWAVE TROUGH PUSHES OUT OF THE CENTRAL CONUS MONDAY AND ACROSS THE AREA MONDAY NIGHT INTO TUESDAY. GFS IS SHOWING A MORE NORTH/SOUTH SPLIT OF THE ENERGY VERSUS THE ECMWF...ALTHOUGH THE ECMWF TO A LESSER EXTENT IS ALSO SHOWING THIS TREND. THUS...SURFACE LOW LOOKS TO BE SOMEWHAT WEAKER. GULF WILL BE OPEN AHEAD OF THE SYSTEM WHICH WILL ALLOW FOR A GOOD FETCH OF MOISTURE AHEAD OF IT. WITH PACIFIC AIRMASS REMAINING IN PLACE QUESTION WILL BE PRECIPITATION TYPES...WITH A LIKELY SCENARIO OF MAINLY SNOW MONDAY NIGHT AND RAIN/SNOW TUESDAY. ANOTHER WAVE DROPS THROUGH THE AREA WEDNESDAY THROUGH THURSDAY AND KEPT PRECIPITATION CHANCES IN THE FORECAST WITH RAIN/SNOW MIX. ALL IN ALL...TEMPERATURES LOOK TO REMAIN MILD AND ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION... 1110 AM CST FRI FEB 17 2012 COLD FRONT SWEEPING WEST TO EAST ACROSS THE REGION THIS AFTERNOON. SUNSHINE INITIALLY POST FRONT...SO LOOK FOR SOME GUSTINESS WITH MIXING. MAIN CONCERNS FOCUS ON AN AREA OF MVFR TO VFR CIGS SINKING SOUTH ACROSS NORTHERN/CENTRAL MN. LATEST RUC13/NAM12 RH FIELDS FAVOR BRINGING THESE CLOUDS OVER KRST/KLSE...WITH PROBABILITIES HIGHER FROM THE MISSISSIPPI RIVER EAST. LITTLE IF ANY -SN ASSOCIATED WITH THESE CLOUDS...AND DON/T EXPECT ANY -SN THAT COULD IMPACT VSBYS AT THIS TIME. THE CLOUDS SHOULD EXIT EAST OVERNIGHT AS AN AREA OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. LOOK FOR VFR CONDITIONS THROUGH THE REST OF THE WEEKEND...WITH NORTHWEST WINDS BECOMING SOUTHERLY ON SUNDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... 305 AM CST FRI FEB 17 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RABERDING LONG TERM....RABERDING AVIATION.....RIECK