Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 04/03/12


AREA FORECAST DISCUSSION
NWS PUEBLO CO
857 PM MDT MON APR 2 2012 .UPDATE... WILL ALLOW HIGH WIND WARNING TO EXPIRE AS ONLY AREA EXCEEDING 50 KNOT GUSTS THE PAST 2 HOURS HAS BEEN HERE AT KPUB...WITH WINDS DIMINISHING SLIGHTLY ELSEWHERE. HRRR SUGGESTS SOME 40-45 KNOT GUSTS OVER EASTERN EL PASO AND NORTHERN PUEBLO COUNTIES STILL POSSIBLE THROUGH 05Z...AND PERHAPS SOME BRIEF CONVECTIVE OUTFLOW WINDS TO AROUND 45 KNOTS ACROSS PROWERS AND BACA COUNTIES FROM TSRA IN KS. PRECIP A LITTLE SLOW TO GET GOING THIS EVENING WITH DRY SURFACE LAYER OVER EASTERN COLORADO AND DEEPEST LIFT JUST SOUTH OF THE AREA. WILL NUDGE POPS DOWNWARD MANY AREAS THROUGH 06Z WITH THIS UPDATE..ESPECIALLY KPUB/KCOS. 00Z NAM RAMPS UP PRECIP AFTER 06Z AS DEEPER MOISTURE PUSHES WESTWARD...WITH A PROLONGED PERIOD OF MODERATE/HEAVY RAIN AND SNOW CONTINUING WELL INTO TUES NIGHT. NAM 00Z QPF INDICATES LIQUID AMOUNTS OVER 2 INCHES OVER THE PALMER DIVIDE AND ACROSS THE SOUTHERN SANGRES/WETS AND I-25 CORRIDOR FROM PUEBLO SOUTHWARD...WHICH SUGGESTS FORECASTS OF 1 TO 2 FEET OF SNOW OVER THE HIGHER TERRAIN LOOK ON TRACK. KCOS/KPUB/CANON CITY PRECIP AMOUNTS STILL TRICKY WITH USUAL PRECIP MINIMUM NEARBY...THOUGH STRENGTH OF ISENTROPIC UPGLIDE SHOULD OVERCOME DOWNSLOPE FLOW FOR SEVERAL HOURS LATE TONIGHT INTO TUES. OVERALL TREND OF THE FORECAST LOOKS GOOD. --PETERSEN && .PREV DISCUSSION... /ISSUED 400 PM MDT MON APR 2 2012/ SHORT TERM... (TONIGHT AND TUESDAY) ..STRONG SPRING STORM TAKING AIM ON SOUTH CENTRAL AND SOUTHEAST COLORADO... MODELS IN REMARKABLE AGREEMENT WITH THE OVERALL DETAILS OF CLOSED UPPER LOW ACROSS EAST CENTRAL NEW MEXICO SHIFTING EASTWARD THEN NORTHEASTWARD INTO THE TX/OK PANHANDLE BY TUES AFTERNOON. FRONT HAS ALREADY SLAMMED THROUGH EASTERN CO EARLIER TODAY...WITH PEAK GUSTS IN EXCESS OF 60 MPH ACROSS PORTIONS OF EL PASO COUNTY. HRRR AND LOCAL 4 KM WRF INDICATED TWO PERIODS OF STRONGER WINDS...ONE THIS MORNING...AND ANOTHER THIS AFTERNOON INTO EARLY THIS EVENING. JUST PICKED UP A GUST TO 50 KTS AT KPUB AIRPORT AROUND 230 PM...SO PERHAPS THE SHORT RANGE MODELS DO HAVE A HANDLE ON THIS. THUS...WILL MAINTAIN HIGH WIND WARNINGS THROUGH 03Z. INTERESTINGLY...HRRR SUGGESTS CORE OF STRONGER WINDS MAY EXPAND ACROSS MORE OF THE SOUTHEAST PLAINS AND CONTINUE THROUGH 06Z...HOWEVER WITH TIGHTEST PRESSURE GRADIENT ALREADY PAST...WILL LEAVE CURRENT EXPIRATION AT 03Z AND LET LATER SHIFTS MONITOR THE TRENDS TO DECIDE IF EXTENSION IN TIME...OR EXPANSION IN AREA IS NECESSARY. LOCAL 4 KM WRF BACKED OFF SOME ON WIND GUSTS AFTER 03Z FOR ALL BUT PERHAPS EASTERN EL PASO COUNTY. OTHER AREA OF CONCERN FOR HIGH WINDS CONTINUES ALONG THE EASTERN SIDE OF THE SAN LUIS VALLEY AS WINDS ACCELERATE THROUGH THE PASSES IN THE SANGRES AND SPILLS INTO THE VALLEY. HRRR AND 12Z 4KM WRF STILL PAINT THIS SCENARIO IN THE LATEST RUNS...WITH PEAK WINDS OCCURRING NOW THROUGH 00Z...WITH GUSTS STARTING TO TAIL OFF BY 03Z. ALS HAD A WIND GUST TO 54 MPH AFTER NOON...WHICH IS VERY CLOSE. SUSPECT LOCAL AREAS TO THE WEST HAD HIGHER GUSTS. AGAIN...WRF KEEPS GUSTS UP AROUND 70 MPH THROUGH 03Z BEFORE TAILING OFF...SO CURRENT HIGHLIGHT LOOKS ON TARGET. FIRST LOBE OF ENERGY WILL ROTATE AROUND THE CLOSED LOW INTO SOUTHEAST COLORADO THIS EVENING. SNOW IS ALREADY OCCURRING ACROSS THE EAST FACING SLOPES OF THE SANGRES/WETS...THOUGH ITS BEEN PRETTY LIGHT SO FAR AS MOISTURE LAYER REMAINS SHALLOW. HOWEVER...RADARS TO THE SOUTH SHOW ECHOES EXPANDING ACROSS NORTHEAST NM WITH SOME EMBEDDED CONVECTION EVIDENT VIA LIGHTNING STRIKES. SHOULD SEE THIS BAND OF SHOWERS SPREAD NORTHWARD THROUGH THE EVENING WITH SNOW SPREADING NORTHWARD AND RAMPING UP ACROSS THE PIKES PEAK AREA AFTER 03-06Z. NICE ISENTROPIC UPGLIDE EVIDENT IN BOTH NAM AND GFS ON THE 300K SFC...AND MODELS IN GOOD AGREEMENT WITH HEAVY QPF AMOUNTS ACROSS A LARGE PORTION OF THE SOUTHEAST PLAINS THROUGH TUESDAY...PARTICULARLY NEAR THE MOUNTAINS. SNOW LEVELS WILL START OFF AROUND 7000 FEET...BUT DROP TO AROUND 5000 FEET OVERNIGHT. TIMING OF THE DROP IN TEMPERATURES AND THE RESIDUAL WARMTH OF THE GROUND WILL PLAY A BIG ROLE IN HOW MUCH SNOW ACCUMULATES ACROSS THE LOWER ELEVATIONS OF THE I-25 CORRIDOR SUCH AS SOUTHERN EL PASO AND PUEBLO COUNTIES. HOWEVER...WITH GOOD MODEL CONSENSUS AND IMPRESSIVE TROWAL ALOFT EXPECTED TO OVERWHELM DOWNSLOPE OFF THE PALMER AT LEAST THROUGH THE 06Z TO 15Z WINDOW...HAVE OPTED TO ISSUE A WINTER WEATHER ADVISORY FOR THE LOWER ELEVATIONS OF THE I-25 CORRIDOR...INCLUDING COLORADO SPRINGS AND PUEBLO. SNOWFALL AMOUNTS WILL LIKELY EXHIBIT A WIDE RANGE WITH SOME MELTING OFF ROAD SURFACES AT TIMES...BUT ANYWHERE FROM 2 INCHES ON THE GRASS...TO AROUND 6 INCHES NEAR THE MOUNTAINS SEEMS PLAUSIBLE. WITH A PERIOD OF EAST TO NORTHEAST WINDS FUNNELING UP THE ARKANSAS RIVER...AND UPSLOPING ALONG THE WEST SIDE OF THE LA GARITAS/AND EASTERN SAN JUANS...WILL INCLUDE THESE AREAS IN A WINTER WEATHER ADVISORY AND RUN IT THROUGH 00Z. BIGGEST WINNER IN THIS EVENT WILL BE THE EAST SLOPES OF THE SANGRES AND WETS 40 TO 50 KTS OF NORTHEAST UPSLOPE WILL RESULT IN 1 TO 2 FEET OF SNOW...WITH HIGHER AMOUNTS ( UP TO 30 INCHES) ACROSS THE HIGHER ELEVATIONS. REMAINDER OF THE HEADLINES IN GOOD SHAPE. TROWAL EVENTUALLY PULLS OFF TO THE NORTHEAST ON TUESDAY WITH SNOW WINDING DOWN FROM SOUTHWEST TO NORTHEAST DURING THE DAY ON TUESDAY. -KT LONG TERM... (TUESDAY NIGHT-MONDAY) ..TIMING AND LOCATION OF UPPER LEVEL STORM LIFTING OUT ACROSS THE SE PLAINS TUESDAY NIGHT THE MAIN FORECAST PROBLEM... TUESDAY NIGHT-WEDNESDAY...SLIGHT MODEL DIFFERENCES ON TIMING AND LOCATION OF UPPER LOW LIFTING OUT ACROSS THE SE PLAINS CONTINUE AND HAVE TAILORED FORECAST TOWARDS THE NAM AND EC WHICH HAVE THE LOW ACROSS EXTREME NORTHEAST NEW MEXICO AT 00Z WED AND THEN SLOWLY LIFT IT OUT ACROSS WESTERN OKLAHOMA INTO CENTRAL OKLAHOMA THROUGH THE DAY ON WEDNESDAY. ONGOING WRAP AROUND PRECIPITATION ACROSS THE EASTERN MTS AND I-25 CORRIDOR TUESDAY AFTERNOON SLOWLY SHIFTS EAST AND DIMINISHES FROM WEST TO EAST OVERNIGHT...AS UPPER LEVEL FLOW BECOMES MORE NORTHWEST. COULD SEE SOME ADDITIONAL LIGHT ACCUMULATIONS OF A COUPLE OF INCHES ACROSS THE NORTH AND EAST FACING SLOPES OF THE EASTERN MTS AND ALONG WITH PALMER DVD AND RATON MESA TUESDAY EVENING WITH THINGS WINDING INTO WEDNESDAY MORNING. TEMPERATURES ALOFT WARM FROM WEST TO EAST THROUGH THE DAY ON WEDNESDAY...AS UPPER LEVEL RIDGING BUILDS INTO THE STATE WITH HIGHS WARMING BACK TO AT OR SLIGHTLY ABOVE SEASONAL AVERAGES...THOUGH HAVE TAPERED BACK HIGHS A TAD IN EXPECTED SNOW COVERED AREAS. WEDNESDAY NIGHT-MONDAY...WARMER AND DRIER WEATHER CONTINUES TO BE PROGGED THROUGH THE PERIOD...WITH MODERATE TO STRONG WESTERLY FLOW EXPECTED ACROSS THE REGION AS SEVERAL SHORT WAVES MOVE ACROSS THE NORTHERN ROCKIES. ONE WAVE MOVES ACROSS THE REGION THURSDAY NIGHT AND FRIDAY...WITH BREEZY TO WINDY CONDITIONS AND POSSIBLE CRITICAL FIRE WEATHER CONDITIONS ON FRIDAY...DEPENDING ON HOW MUCH PRECIP FALLS. PASSING WAVE SENDS A DRY COLD FRONT ACROSS THE PLAINS FRIDAY WITH SLIGHTLY COOLER TEMPERATURES ACROSS THE AREA ON SATURDAY. ANOTHER WAVE POSSIBLE MOVES ACROSS THE NORTHERN ROCKIES ON SUNDAY NIGHT...WITH A BACKDOOR COLD FRONT POSSIBLE BRINGING IN ENOUGH LOW LEVEL MOISTURE FOR A FEW SHOWERS ACROSS THE EASTERN PLAINS ON MONDAY. HOWEVER...WILL KEEP A DRY FORECAST IN TACT THROUGH THE PERIOD. -MW AVIATION... IFR CIGS/VIS EXPECTED TO AFFECT THE TAF SITES TONIGHT AS STRONG SYSTEM MOVES ACROSS NORTHERN NEW MEXICO. STRONG NORTH WINDS IN THE 30 TO 45 KT RANGE WILL CONTINUE AT KCOS AND KPUB BEFORE DECREASING TOWARDS 06Z. KALS WILL CONTINUE TO SEE EAST WINDS IN THE 25 TO 40 KT RANGE THROUGH EARLY EVENING WITH PERIODS OF BLDU. HEAVIEST SNOW WILL IMPACT KCOS AND KPUB BETWEEN 06Z-18Z PERIOD WITH POTENTIAL FOR A COUPLE INCHES OF SNOW...MAINLY ON GRASSY SURFACES AT KPUB...TO AROUND 2 TO 5 INCHES AT KCOS. WITH WARM GROUND...THERE WILL BE SOME MELTING AT TIMES AT KCOS...BUT PAVED SURFACES COULD BECOME SLUSHY AND SNOWPACKED UNDER THE HEAVIER SNOW BANDS. KALS COULD SEE AN INCH OR TWO AS WELL. RAIN/SNOW SWITCH OVER WILL OCCUR AROUND 03Z FOR KCOS AND KALS...AND AROUND 06Z FOR KPUB. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075- 078>080-087-088. WINTER WEATHER ADVISORY UNTIL 6 PM MDT TUESDAY FOR COZ058- 060>063-076-077. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY FOR COZ083-085-086. WINTER WEATHER ADVISORY UNTIL 6 PM MDT TUESDAY FOR COZ066>068. WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ081-082-084. && $$ 77/10
AREA FORECAST DISCUSSION
NWS ALBANY NY
133 PM EDT SUN APR 1 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE FROM THE GREAT LAKES AND ACROSS THE REGION THIS AFTERNOON INTO TONIGHT...ALLOWING FOR SOME RAIN SHOWERS. SOME WET SNOW MAY MIX IN WITH THE RAIN SHOWERS ACROSS THE HIGHEST TERRAIN TONIGHT. HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION PROVIDING FAIR WEATHER FOR EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM...RADAR INDICATES SHOWERS MOVING SLIGHTLY FASTER THAN CURRENT HOURLY POPS INDICATE...SO HAVE SHIFTED HOURLY POP/WX GRIDS AHEAD BY AN HOUR. REST OF PREVIOUS FORECAST LOOKS GOOD AND WAS UNCHANGED. ****PREVIOUS DISCUSSION**** LATEST VISIBLE SATELLITE IMAGERY SHOWS THAT LOWER STRATUS CLOUDS HAVE COMPLETELY OVERTAKEN THE CWA. MEANWHILE...THE 12 UTC KALY SOUNDING SHOWS ENOUGH DRY AIR IN PLACE FOR THE BOTTOM FEW THOUSAND FEET OF THE COLUMN...AND BUFR MODEL SOUNDING SUPPORT THIS HOLDING FOR A FEW HOURS AS WELL. THE LATEST REGIONAL RADAR IMAGERY CONTINUES TO SHOW NO RETURNS ACROSS OUR AREA...BUT INCREASING AMOUNTS OF LIGHT TO MODERATE PRECIP ACROSS WESTERN NY/LAKE ONTARIO DUE TO A SHORTWAVE AND WEAK SURFACE LOW ACROSS THE GREAT LAKES. FOR NOW...WILL CONTINUE TO FORECAST CLOUDY...BUT DRY WEATHER FOR MUCH OF THE AREA THROUGH AROUND NOON. FOR THE AFTERNOON HOURS...WILL STEADILY INCREASE POPS TO CATEGORICAL FOR MOST AREAS BY THE LATE AFTN HOURS. THE NEW 12 UTC NAM AND 10 UTC 3KM HRRR ALL SHOW BATCHES OF LIGHT RAIN SHOWERS MOVING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST THROUGH THE AFTN AND EVENING HOURS...WITH THE BEST QPF ACROSS THE CATSKILLS...AS THE LOW PRESSURE WAVE MOVES ACROSS OUR AREA. ALTHOUGH QPF SHOULD BE FAIRLY LIGHT...ALL AREAS SEEM TO AT LEAST GET A FEW HUNDREDTHS...SO HIGH LIKELY/CATEGORICAL POPS SEEM WARRANTED. MAX TEMPS TODAY WILL PROBABLY BE IN THE EARLY AFTN JUST BEFORE THE START OF PRECIP...WITH TEMPS RANGING FROM THE UPPER 30S ACROSS THE SRN DACKS TO NEAR 50 IN THE MID HUDSON VALLEY. AFTER 00 UTC...WILL START TO LOWER POPS FROM NORTHWEST TO SOUTHEAST...AS MODEL GUIDANCE SHOWS THE BEST FORCING AND ASSOCIATED PRECIPITATION DROPPING SOUTHEAST OF THE REGION. AT THE HIGHEST TERRAIN /GENERALLY 2500 FT AND ABOVE/...ANY LINGERING RAIN SHOWERS COULD START TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS AS TEMPS ALOFT START TO CRASH. ANY SNOW ACCUMULATION LOOKS VERY LIGHT...OF ABOUT A HALF INCH OR SO...AND MAINLY LIMITED TO THE HIGH PEAKS OF THE CATSKILLS AND HIGHEST ELEVATIONS IN SOUTHERN VERMONT. A COATING OF SNOW IS POSSIBLE ACROSS THE SOUTHERN ADIRONDACKS AS WELL. VALLEY AREAS WILL PROBABLY JUST STAY AS RAIN SHOWERS BEFORE ENDING AND NO SNOW ACCUMULATION IS EXPECTED IN ANY VALLEY AREAS AT THIS TIME. ANY PRECIP SHOULD BE FINISHED BY AROUND 06 UTC...WITH CLEARING TAKING PLACE FOR THE REMAINDER OF THE NIGHT...AS SKIES BECOME PARTLY CLOUDY. THIS SHOULD ALLOW TEMPS TO FALL OFF...WITH MIN TEMPS RANGING FROM THE 20S IN THE DACKS TO THE MID 30S IN THE CAPITAL REGION/MID HUDSON VALLEY. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9 HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA SHORT WAVES WED. FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN OUT. && .LONG TERM /TUESDAY THROUGH SATURDAY/... GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS 500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... RAIN SHOWERS OVER CENTRAL NEW YORK AND THE MOHAWK VALLEY ARE ADVANCING EAST SOUTHEAST TOWARDS THE HUDSON VALLEY TAF SITES. WITH DRY AIR IN PLACE AT LOW LEVELS...IT MAY TAKE A LITTLE BIT UNTIL THE BOUNDARY LAYER MOISTENS UP ENOUGH TO REDUCE FLYING CONDITIONS. WITH SITES CURRENTLY VFR...IT MAY TAKE UNTIL THE MID TO LATE AFTN FOR VSBYS/CIGS TO BE REDUCED TO MVFR. RAINFALL SHOULD BE LIGHT...AND BASED ON UPSTREAM CONDITIONS...DO NOT ANTICIPATE ANY IFR CONDITIONS WITHIN THIS RAINFALL. SFC WINDS WILL BE LIGHT AND VARIABLE. RAIN SHOWERS SHOULD TAPER OFF LATER IN THE EVENING...LINGERING LONGEST /PERHAPS TOWARDS MIDNIGHT/ NEAR KPOU. AFTERWARD...WINDS WILL SWITCH TO W-NW DIRECTION AND BECOME STRONGER...ABOUT 5-10 KTS. ANY MVFR CIGS SHOULD GIVE WAY TO VFR CONDITIONS...AS LOWER CLOUDS LIFT TO 4-6 KFT AND BECOME SCT-BKN. ON MONDAY...VFR CONDITIONS ARE EXPECTED WITH JUST SCT CU AROUND 6 KFT. WITHIN DAYTIME MIXING...N-NW WINDS WILL BE GUSTY AT TIMES...ESP IN AREAS OF CHANNELED FLOW. SOME GUSTS MAY REACH 20-25 KTS...ESP BY AFTN. OUTLOOK... MON PM-TUE...VFR...NO SIG WX. TUE NT...MAINLY VFR...CHC -SHRA. WED-THU...VFR...NO SIG WX. && .FIRE WEATHER... LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK. AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE BETWEEN 80 AND 90 PERCENT. SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS. THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND ENDING THE WEEK ABV NORMALS. 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...FRUGIS NEAR TERM...FRUGIS/GJM SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
110 AM EDT SUN APR 1 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE FROM THE GREAT LAKES AND ACROSS THE REGION THIS AFTERNOON INTO TONIGHT...ALLOWING FOR SOME RAIN SHOWERS. SOME WET SNOW MAY MIX IN WITH THE RAIN SHOWERS ACROSS THE HIGHEST TERRAIN TONIGHT. HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION PROVIDING FAIR WEATHER FOR EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM...RADAR INDICATES SHOWERS MOVING SLIGHTLY FASTER THAN CURRENT HOURLY POPS INDICATE...SO HAVE SHIFTED HOURLY POP/WX GRIDS AHEAD BY AN HOUR. REST OF PREVIOUS FORECAST LOOKS GOOD AND WAS UNCHANGED. ****PREVIOUS DISCUSSION**** LATEST VISIBLE SATELLITE IMAGERY SHOWS THAT LOWER STRATUS CLOUDS HAVE COMPLETELY OVERTAKEN THE CWA. MEANWHILE...THE 12 UTC KALY SOUNDING SHOWS ENOUGH DRY AIR IN PLACE FOR THE BOTTOM FEW THOUSAND FEET OF THE COLUMN...AND BUFR MODEL SOUNDING SUPPORT THIS HOLDING FOR A FEW HOURS AS WELL. THE LATEST REGIONAL RADAR IMAGERY CONTINUES TO SHOW NO RETURNS ACROSS OUR AREA...BUT INCREASING AMOUNTS OF LIGHT TO MODERATE PRECIP ACROSS WESTERN NY/LAKE ONTARIO DUE TO A SHORTWAVE AND WEAK SURFACE LOW ACROSS THE GREAT LAKES. FOR NOW...WILL CONTINUE TO FORECAST CLOUDY...BUT DRY WEATHER FOR MUCH OF THE AREA THROUGH AROUND NOON. FOR THE AFTERNOON HOURS...WILL STEADILY INCREASE POPS TO CATEGORICAL FOR MOST AREAS BY THE LATE AFTN HOURS. THE NEW 12 UTC NAM AND 10 UTC 3KM HRRR ALL SHOW BATCHES OF LIGHT RAIN SHOWERS MOVING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST THROUGH THE AFTN AND EVENING HOURS...WITH THE BEST QPF ACROSS THE CATSKILLS...AS THE LOW PRESSURE WAVE MOVES ACROSS OUR AREA. ALTOUGH QPF SHOULD BE FAIRLY LIGHT...ALL AREAS SEEM TO AT LEAST GET A FEW HUNDREDTHS...SO HIGH LIKELY/CATEGORICAL POPS SEEM WARRANTED. MAX TEMPS TODAY WILL PROBABLY BE IN THE EARLY AFTN JUST BEFORE THE START OF PRECIP...WITH TEMPS RANGING FROM THE UPPER 30S ACROSS THE SRN DACKS TO NEAR 50 IN THE MID HUDSON VALLEY. AFTER 00 UTC...WILL START TO LOWER POPS FROM NORTHWEST TO SOUTHEAST...AS MODEL GUIDANCES SHOWS THE BEST FORCING AND ASSOCIATED PRECIPITATION DROPPING SOUTHEAST OF THE REGION. AT THE HIGHEST TERRAIN /GENERALLY 2500 FT AND ABOVE/...ANY LINGERING RAIN SHOWERS COULD START TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS AS TEMPS ALOFT START TO CRASH. ANY SNOW ACCUMULATION LOOKS VERY LIGHT...OF ABOUT A HALF INCH OR SO...AND MAINLY LIMITED TO THE HIGH PEAKS OF THE CATSKILLS AND HIGHEST ELEVATIONS IN SOUTHERN VERMONT. A COATING OF SNOW IS POSSIBLE ACROSS THE SOUTHERN ADIRONDACKS AS WELL. VALLEY AREAS WILL PROBABLY JUST STAY AS RAIN SHOWERS BEFORE ENDING AND NO SNOW ACCUMULATION IS EXPECTED IN ANY VALLEY AREAS AT THIS TIME. ANY PRECIP SHOULD BE FINISHED BY AROUND 06 UTC...WITH CLEARING TAKING PLACE FOR THE REMAINDER OF THE NIGHT...AS SKIES BECOME PARTLY CLOUDY. THIS SHOULD ALLOW TEMPS TO FALL OFF...WITH MIN TEMPS RANGING FROM THE 20S IN THE DACKS TO THE MID 30S IN THE CAPITAL REGION/MID HUDSON VALLEY. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9 HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA SHORT WAVES WED. FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN OUT. && .LONG TERM /TUESDAY THROUGH SATURDAY/... GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS 500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS DESPITE THE EXPANDING STRATUS DECK ACROSS THE REGION. UPSTREAM SYSTEM APPROACHES DURING THE DAY WITH LOWER CIGS AND INCREASING CHANCES FOR WET CONDITIONS. THERE WILL BE A PERIOD LATER THIS AFTERNOON INTO EARLY EVENING WITH MVFR FLIGHT CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS EARLY SUNDAY MORNING. THOSE WINDS BECOME WEST-SOUTHWEST LATE THIS MORNING IN ADVANCE OF THIS SYSTEM AT SPEEDS LESS THAN 10KTS. WINDS QUICKLY SHIFT TO THE NORTH-NORTHWEST IN THE WAKE OF THIS STORM THIS EVENING AROUND 10 KTS AND CONTINUE OVERNIGHT. OUTLOOK... MON-TUE...VFR...NO SIG WX. TUE NT...MAINLY VFR...CHC -RA OR -SHRA. WED-THU...VFR...NO SIG WX. && .FIRE WEATHER... LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK. AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE BETWEEN 80 AND 90 PERCENT. SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS. THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND ENDING THE WEEK ABV NORMALS. 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...FRUGIS NEAR TERM...GJM/FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...BGM FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1038 AM EDT SUN APR 1 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE FROM THE GREAT LAKES AND ACROSS THE REGION THIS AFTERNOON INTO TONIGHT...ALLOWING FOR SOME RAIN SHOWERS. SOME WET SNOW MAY MIX IN WITH THE RAIN SHOWERS ACROSS THE HIGHEST TERRAIN TONIGHT. HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION PROVIDING FAIR WEATHER FOR EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST VISIBLE SATELLITE IMAGERY SHOWS THAT LOWER STRATUS CLOUDS HAVE COMPLETELY OVERTAKEN THE CWA. MEANWHILE...THE 12 UTC KALY SOUNDING SHOWS ENOUGH DRY AIR IN PLACE FOR THE BOTTOM FEW THOUSAND FEET OF THE COLUMN...AND BUFR MODEL SOUNDING SUPPORT THIS HOLDING FOR A FEW HOURS AS WELL. THE LATEST REGIONAL RADAR IMAGERY CONTINUES TO SHOW NO RETURNS ACROSS OUR AREA...BUT INCREASING AMOUNTS OF LIGHT TO MODERATE PRECIP ACROSS WESTERN NY/LAKE ONTARIO DUE TO A SHORTWAVE AND WEAK SURFACE LOW ACROSS THE GREAT LAKES. FOR NOW...WILL CONTINUE TO FORECAST CLOUDY...BUT DRY WEATHER FOR MUCH OF THE AREA THROUGH AROUND NOON. FOR THE AFTERNOON HOURS...WILL STEADILY INCREASE POPS TO CATEGORICAL FOR MOST AREAS BY THE LATE AFTN HOURS. THE NEW 12 UTC NAM AND 10 UTC 3KM HRRR ALL SHOW BATCHES OF LIGHT RAIN SHOWERS MOVING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST THROUGH THE AFTN AND EVENING HOURS...WITH THE BEST QPF ACROSS THE CATSKILLS...AS THE LOW PRESSURE WAVE MOVES ACROSS OUR AREA. ALTOUGH QPF SHOULD BE FAIRLY LIGHT...ALL AREAS SEEM TO AT LEAST GET A FEW HUNDREDTHS...SO HIGH LIKELY/CATEGORICAL POPS SEEM WARRANTED. MAX TEMPS TODAY WILL PROBABLY BE IN THE EARLY AFTN JUST BEFORE THE START OF PRECIP...WITH TEMPS RANGING FROM THE UPPER 30S ACROSS THE SRN DACKS TO NEAR 50 IN THE MID HUDSON VALLEY. AFTER 00 UTC...WILL START TO LOWER POPS FROM NORTHWEST TO SOUTHEAST...AS MODEL GUIDANCES SHOWS THE BEST FORCING AND ASSOCIATED PRECIPITATION DROPPING SOUTHEAST OF THE REGION. AT THE HIGHEST TERRAIN /GENERALLY 2500 FT AND ABOVE/...ANY LINGERING RAIN SHOWERS COULD START TO MIX WITH OR CHANGE OVER TO SNOW SHOWERS AS TEMPS ALOFT START TO CRASH. ANY SNOW ACCUMULATION LOOKS VERY LIGHT...OF ABOUT A HALF INCH OR SO...AND MAINLY LIMITED TO THE HIGH PEAKS OF THE CATSKILLS AND HIGHEST ELEVATIONS IN SOUTHERN VERMONT. A COATING OF SNOW IS POSSIBLE ACROSS THE SOUTHERN ADIRONDACKS AS WELL. VALLEY AREAS WILL PROBABLY JUST STAY AS RAIN SHOWERS BEFORE ENDING AND NO SNOW ACCUMULATION IS EXPECTED IN ANY VALLEY AREAS AT THIS TIME. ANY PRECIP SHOULD BE FINISHED BY AROUND 06 UTC...WITH CLEARING TAKING PLACE FOR THE REMAINDER OF THE NIGHT...AS SKIES BECOME PARTLY CLOUDY. THIS SHOULD ALLOW TEMPS TO FALL OFF...WITH MIN TEMPS RANGING FROM THE 20S IN THE DACKS TO THE MID 30S IN THE CAPITAL REGION/MID HUDSON VALLEY. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9 HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA SHORT WAVES WED. FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN OUT. && .LONG TERM /TUESDAY THROUGH SATURDAY/... GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS 500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS DESPITE THE EXPANDING STRATUS DECK ACROSS THE REGION. UPSTREAM SYSTEM APPROACHES DURING THE DAY WITH LOWER CIGS AND INCREASING CHANCES FOR WET CONDITIONS. THERE WILL BE A PERIOD LATER THIS AFTERNOON INTO EARLY EVENING WITH MVFR FLIGHT CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS EARLY SUNDAY MORNING. THOSE WINDS BECOME WEST-SOUTHWEST LATE THIS MORNING IN ADVANCE OF THIS SYSTEM AT SPEEDS LESS THAN 10KTS. WINDS QUICKLY SHIFT TO THE NORTH-NORTHWEST IN THE WAKE OF THIS STORM THIS EVENING AROUND 10 KTS AND CONTINUE OVERNIGHT. OUTLOOK... MON-TUE...VFR...NO SIG WX. TUE NT...MAINLY VFR...CHC -RA OR -SHRA. WED-THU...VFR...NO SIG WX. && .FIRE WEATHER... LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK. AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE BETWEEN 80 AND 90 PERCENT. SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS. THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND ENDING THE WEEK ABV NORMALS. 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...FRUGIS NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...BGM FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
634 AM EDT SUN APR 1 2012 .SYNOPSIS... LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE ACROSS THE REGION TODAY. A LOBE OF HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION FROM HUDSON BAY MONDAY...AND SLIDE OFFSHORE TUESDAY. LATE TUESDAY A COLD FRONT DROP THROUGH THE REGION. WEDNESDAY THROUGH THE END OF THE WEEK...THE REST OF THE HUDSONS BAY HIGH PRESSURE AREA WILL BUILD INTO THE GREAT LAKES WHILE A STORM LINGERS IN THE MARITIMES. && .NEAR TERM /THROUGH TONIGHT/... STRATUS DECK EXPANDING SLOWLY THIS EARLY SUNDAY MORNING PER THE 11U-3.9U IMAGERY. MEANWHILE...AN INCREASE IN HIGH LEVEL MOISTURE WAS UNDERWAY FROM THE CLIPPER TYPE SYSTEM ACROSS THE NORTHERN GREAT LAKES REGION. PER THE SATELLITE DERIVED WINDS...THE UPPER JET WAS GREATER THAN 120KTS...SO A RATHER DYNAMIC SYSTEM. FORECAST BUFR PROFILES ALL SUGGEST THE LOW LEVEL DRY AIR WILL HANG ON TOUGH THROUGH MOST OF THE MORNING AND WILL CUT BACK POPS ACCORDINGLY. LATEST RUC13/HRRR DOES SUGGEST SHOWER ACTIVITY WILL DEVELOP AND BECOME ENHANCED WITH FAVORABLE UPSLOPE CONDITIONS THROUGH THE NOON HOUR AND INTO THE AFTERNOON AND WE WILL RAISE POPS INTO THE LIKELY CATEGORY. LATEST HRRR CONTINUES ALONG THIS FORECAST LINE THIS SUNDAY MORNING. THERMAL PROFILES ARE CHILLY YET THOSE BOUNDARY LAYER VALUES ARE EXPECTED TO REMAIN RATHER MILD TODAY. THE FREEZING LEVEL FORECASTS FROM THE NCEP MODEL SUITE SUGGEST FOR SNOW LEVELS WILL BE RATHER HIGH...AT OR ABOVE 2K FEET. SO FOR MOST OF THE REGION...EXPECTATIONS ARE FOR MAINLY RAIN/RAIN SHOWERS TODAY UNDER CLOUDY SKIES. WE WILL SHADE A LITTLE CLOSER TO THE COOLER SIDE OF THE GUIDANCE ENVELOPE WHICH IS IN LINE WITH THE LATEST LAV/LAMP. PRECIP WILL END FROM NORTHWEST TO SOUTHEAST THIS EVENING WITH THE QUICK DEPARTURE OF THIS SYSTEM. SOME UPSLOPE CLOUD ENHANCEMENT...ESPECIALLY FOR OUR ADJACENT WESTERN NEW ENGLAND COUNTIES...ARE EXPECTED BUT WE WILL DIMINISH THOSE POPS ACCORDINGLY. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... MONDAY INTO TUESDAY MODEL SUITE IS IN AGREEMENT OTHER THAN 6-9 HOURS DIFFERENCE IN TIMING OF TUES CDFNT AND INTENSITY OF 500HPA SHORT WAVES WED. FAST MOVING FLOW AT 500HPA OVER RGN...AS 500HPA TROF DEPARTS...RIDGE BUILDS EAST...ANOTHER SHORT WV FOLLOWS LATE TUESDAY. TUESDAY NIGHT SOME DIFFERENCES BEGIN TO EMERGE. AT SFC MASSIVE HIGH BUILDS FM HUDSONS BAY S INTO GRTLKS AS A SERIES OF STRONG 500HPA SHORT WVS DIVE SE ACROSS THE RGN. THE MODEL SUITE GENERALLY (GFS/GEM/12UTC ECMWF) ARE AGGRESSIVE WITH THE SHORT WAVES...THE NAM THE LEAST AND THE OUTLIER. THE MORE AGGRESSIVE SHORT WV SOLUTION RESULTS IN SOME INSTAB -SHRA/SN AT HIR TRRN...VRBL CLOUDS...BRISK N WINDS AND THIS SOLUTION IS THE ONE THE FCST WILL LEAN TWRD WITH NAM BEING THROWN OUT. && .LONG TERM /THURSDAY THROUGH SATURDAY/... GFS AND ECMWF FAIRLY SIMILAR IN THIS PERIOD. 500HPA TROF OVER MARITIMES WILL SLOWLY DEPART...MASSIVE SFC HIGH FM HUDSONS BAY WILL BUILD INTO GRTLKS. FCA WILL BE BTWN THESE TWO SYSTEMS WITH GENERALLY DRY CONDS...SOME CLOUDS INTO FRI AS 500 HPA SHORT WAVES ROTATED ACROSS FCA. BY SAT SFC HIGH HAS MOVED INTO RGN. GFS SHIFTS 500HPA TROF OFFSHORE...ECMWF HAS CUTOFF FORM ALONG DELMARVA/SE COAST WHILE GFS KEEPS PROGRESSIVE TROFS MOVING OFFSHORE. ECMWF DEVELOPS POTENTIAL COASTAL SFC LOW THAT DRIFTS N WITH CUTOFF. THIS SYSTEM BACKS INTO FCA SUN WITH CLDS AN LT RN. FOR NOW WILL GO W/GMOS SOLUTION. SINCE ONLY DIFFERENCE IS IN DAYS 7-8. TEMPS WILL REMAIN NR NRMLS...REACHING 5 DEGREES ABV BY END OF PD. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS DESPITE THE EXPANDING STRATUS DECK ACROSS THE REGION. UPSTREAM SYSTEM APPROACHES DURING THE DAY WITH LOWER CIGS AND INCREASING CHANCES FOR WET CONDITIONS. THERE WILL BE A PERIOD LATER THIS AFTERNOON INTO EARLY EVENING WITH MVFR FLIGHT CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS EARLY SUNDAY MORNING. THOSE WINDS BECOME WEST-SOUTHWEST LATE THIS MORNING IN ADVANCE OF THIS SYSTEM AT SPEEDS LESS THAN 10KTS. WINDS QUICKLY SHIFT TO THE NORTH-NORTHWEST IN THE WAKE OF THIS STORM THIS EVENING AROUND 10 KTS AND CONTINUE OVERNIGHT. OUTLOOK... MON-TUE...VFR...NO SIG WX. TUE NT...MAINLY VFR...CHC -RA OR -SHRA. WED-THU...VFR...NO SIG WX. && .FIRE WEATHER... LOW PRESSURE DROPPING SOUTHEAST FROM THE GREAT LAKES WILL MOVE ACROSS THE REGION TODAY INTO THIS EVENING...THEN A MASSIVE HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION FOR EARLY NEXT WEEK. AS SHOWERS MOVE ACROSS THE REGION...RELATIVE HUMIDITY VALUES WILL GENERALLY REMAIN ABOVE 50 PERCENT. AS THIS SYSTEM DEPARTS TONIGHT...THE WET WEATHER ALSO SUBSIDES AS RELATIVE HUMIDITIES RANGE BETWEEN 80 AND 90 PERCENT. SURFACE WINDS WILL BE WEST-SOUTHWEST AT 5 TO 15 MPH TODAY...BECOMING NORTHERLY TONIGHT AT 10 MPH OR LESS...THEN INCREASING TOWARD SUNRISE AND THROUGH THE DAY MONDAY WITH GUSTS OVER 20 MPH. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS. THE ONLY PCPN EXPECTED IN THE NEXT WEEK WILL BE A QUARTER TO THIRD INCH TODAY...ISOLATED -SHRA LATE TUESDAY. OTHERWISE WILL BE DRY WITH TEMPS BLO NORMAL AT FIRST...RISING NEAR NORMAL MID WEEK AND ENDING THE WEEK ABV NORMALS. 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...SNYDER NEAR TERM...BGM SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...BGM FIRE WEATHER...BGM HYDROLOGY...BGM WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
935 PM EDT MON APR 2 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE REGION TONIGHT. LOW PRESSURE IN THE OHIO VALLEY TUESDAY WILL MOVE TO SOUTHERN NEW ENGLAND WEDNESDAY MORNING WITH ANOTHER COLD FRONTAL PASSAGE DURING THE DAY WEDNESDAY. CANADIAN HIGH PRESSURE WILL VERY SLOWLY BUILD INTO THE MID ATLANTIC STATES LATE THIS WEEK THROUGH THE WEEKEND PROBABLY PROVIDING AN EXTENDED SPELL OF DRY WEATHER. THE NEXT CHANCE FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER COLD FRONTAL PASSAGE EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THE BEST PRESSURE GRADIENT IS ABOUT TO EXIT THE NEW JERSEY COAST THIS EVENING. THE GUSTINESS TO THE WIND HAS DROPPED OFF ACROSS MUCH OF EASTERN PENNSYLVANIA (OUTSIDE OF THE TERRAIN) AND MUCH WESTERN NEW JERSEY. GUSTS CONTINUE ACROSS PORTIONS OF EASTERN NEW JERSEY AND COASTAL DELAWARE...WHERE THE MIXING IS STILL OCCURRING. A RECENT AMDAR SOUNDING FROM KPHL SHOWED THAT THE LOW LEVEL INVERSION WAS TRYING TO SET UP...WITH 35 TO 40 KNOTS OF WIND AT THE TOP OF THE INVERSION. THIS WOULD SUGGEST THAT PROTECTED AREAS PROBABLY SEE WINDS DROP OFF TO LESS THAN 6 MPH DURING THE NEXT COUPLE OF HOURS. ELSEWHERE...THE GRADIENT WIND REMAINS...BUT THE GUSTINESS IS PROBABLY DONE FOR THE NIGHT. A DRY MID LEVEL SHORT WAVE DROPPING DOWN THE BACK OF THE CLOSED MD LEVEL SYSTEM WILL CROSS THE AREA LATE THIS EVENING AND EARLY TUESDAY MORNING. THIS COULD ALLOW THE PRESSURE GRADIENT TO INCREASE A BIT...BUT THE LOWER LEVELS SHOULD BE STRATIFIED ENOUGH BY THEN TO TAMP DOWN MUCH GUSTINESS. IN ANY EVENT...THE LOWER WINDS THIS EVENING IS ALLOWING TEMPERATURES TO TUMBLE IN THE DRY AIRMASS IN PLACE. BASED ON THE TEMPERATURE TRENDS...AND THE LOW DEW POINTS...LOWS WERE NUDGED DOWN IN THE NORMALLY COLDER LOCATIONS...ESPECIALLY THE NEW JERSEY PINE BARRENS. BASED ON THE CHANGE...PATCHY FROST WAS ADDED TO PHILADELPHIA AND DELAWARE COUNTIES IN SOUTHEAST PENNSYLVANIA... BUT IT MAY BE TOO DRY FOR MUCH MORE THAN THAT IN THESE LOCATIONS. BASED ON THE ABOVE...THE FROST ADVISORY WILL NOT BE EXTENDED INTO PHILADELPHIA. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... HIGH PRESSURE AT THE SURFACE BUILDS ACROSS THE AREA ON TUESDAY, WHILE SLIGHT RIDGING ALOFT BUILDS ACROSS THE AREA. THICKNESSES ARE EXPECTED TO RISE, ALONG WITH 925/850 MB TEMPERATURES. MAX TEMPERATURES ARE EXPECTED TO RISE INTO THE LOW/MID 60S IN MOST PLACES, WITH SOME UPPER 60S POSSIBLE. THE HIGHER ELEVATIONS IN THE NORTHERN ZONES AND AREAS RIGHT ALONG THE COAST WILL BE COOLER WITH TEMPS MAXING OUT IN THE MID/UPPER 50S. WINDS ARE EXPECTED TO GUST PRETTY STRONG IN THE MORNING, BUT SHOULD SLOWLY DIMINISH THROUGH THE DAY AS THE HIGH SINKS SOUTHWARD ACROSS THE AREA. SKIES SHOULD REMAIN MOSTLY CLEAR, EXCEPT SOME CIRRUS LATE IN THE DAY. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... OVERALL...A DRY AND SEASONABLE TEMPERATURE REGIME WILL BE PREDOMINANT DURING THIS TIME PERIOD. THE EXCEPTIONS WILL BE NEAR THE BEGINNING AND END OF THIS TIME. A COLD FRONTAL PASSAGE ON WEDNESDAY WILL BRING THE POSSIBILITY OF SOME VERY LIGHT PRECIPITATION. POPS ARE IN THE SLIGHT CHANCE/CHANCE RANGE FOR THE TUESDAY NIGHT AND WEDNESDAY TIME PERIOD. DRY CONDITIONS ARE EXPECTED FROM WEDNESDAY NIGHT INTO SUNDAY. ANOTHER CHANCE FOR PRECIPITATION WILL OCCUR WITH A COLD FRONTAL PASSAGE EXPECTED MONDAY OF NEXT WEEK. TEMPERATURES WILL BE VERY CLOSE TO SEASONAL NORMS (WHICH MEANS THEY WILL FEEL PRETTY COOL COMPARED TO RECENT WEATHER). FROST/FREEZE CONDITIONS WILL BE POSSIBLE, WITH THE BEST CHANCES ON FRIDAY MORNING AND AGAIN SATURDAY MORNING. LATER FORECASTS WILL REFINE THE TIMING AND AREAL COVERAGE. THIS FORECAST CONTINUES THE PATTERN OF ABNORMALLY DRY WEATHER THAT HAS AFFECTED THE REGION FOR THE PAST SEVERAL MONTHS. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS CONTINUE EARLY THIS EVENING WITH CLEAR SKIES. THE NORTH TO NORTHWEST GRADIENT ALSO REMAINS IN PLACE...AS WEAKENING SURFACE HIGH PRESSURE BUILDS SOUTHEAST FROM THE GREAT LAKES. A RECENT AMDAR SOUNDING FROM KPHL SUGGESTS THAT THE SURFACE IS ATTEMPTING TO DECOUPLE FROM THE REST OF THE MIXED LAYER. HOWEVER... WINDS AT THE TOP OF THE MIXED LATER ARE STILL NEAR 40 KNOTS...SO GUSTINESS COULD CONTINUE THROUGH 0300 UTC OR SO (ESPECIALLY FOR THE KPHL METRO AIRPORTS). NEAR TERM MODELS SUGGEST ANOTHER PUSH OF LOW LEVEL WINDS COULD ARRIVE AROUND 0600 UTC TUESDAY. THE DECOUPLING SHOULD BE A BIT MORE PRONOUNCED...SO FOR NOW NO ADDITIONAL GUSTINESS WAS INCLUDED IN THE FORECAST. HEATING WEDNESDAY MORNING SHOULD ALLOW GUSTINESS TO DEVELOPMENT AFTER 1400 OR 1500 UTC AT JUST ABOUT ALL TERMINAL LOCATIONS. VFR CONDITIONS ARE EXPECTED...WITH SOME MID LEVEL CLOUDS POSSIBLE LATE IN THE DAY. OUTLOOK... TUESDAY NIGHT...CIGS LOWER TO 4000 FT IN WIDELY SCT SHOWERS LATE. WEDNESDAY...VFR WITH SCT DIURNAL SC IN THE AFTN NEAR 5000 FT. AFTERNOON NW GUSTS 18 TO 22 KTS. THURSDAY/FRIDAY/SATURDAY...VFR. NW WIND G10-15KTS. AFTERNOON SEA BREEZES POSSIBLE. && .MARINE... WINDS HAVE TEMPORARILY DROPPED BELOW SMALL CRAFT LEVELS ACROSS ALL WATERS THIS EVENING. IN ADDITION...THE 6 FOOT SHORT PERIOD WIND WAVES HAVE BEEN REPLACED BY 4 FOOT LONGER PERIOD SWELL...AND IT APPEARS AS THOUGH SEAS ON THE OCEAN PROBABLY REMAIN BELOW 5 FEET FOR THE BALANCE OF THE NIGHT. THE QUANDARY IS WHAT TO DO WITH THE SMALL CRAFT ADVISORY. THE LATEST NAM AND HRRR MODELS SHOW ANOTHER PUSH OF WIND WITH THE PASSAGE OF A MID LEVEL SYSTEM LATE THIS EVENING AND EARLY TUESDAY MORNING. THE MODELED PUSH WOULD BRING WINDS BACK TO SMALL CRAFT LEVELS (AT LEAST ON THE OCEAN WATERS)...AND MODEL SOUNDINGS SUGGEST THE GUSTS COULD CONTINUE THROUGH 600 AM. WHILE WINDS ARE BELOW THE LIMITS NOW...WOULD HATE TO DROP THE ADVISORY WITH ANOTHER PUSH ON THE WAY. LATER SHIFTS CAN ADJUST THE SMALL CRAFT ADVISORY IF THE WINDS TO NOT MATERIALIZE. THE SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 6 AM...ALTHOUGH IT IS POSSIBLE THAT THERE MAY BE A FEW GUSTS EARLY IN THE DAY TUESDAY, BEFORE DIMINISHING THROUGH THE DAY. HOWEVER...WE DID NOT EXTEND THE ADVISORY INTO THE DAY TUESDAY AS WE ARE NOT CONFIDENT ON THE WINDS REMAINING ELEVATED. LATER SHIFTS CAN EXTEND IF THEY NEED TO. OUTLOOK... WED...MODERATE PROBABILITY AN SCA WOULD BE NEEDED FOR A PART OF THIS DAY. THU-FRI-SAT...PROBABLY NO HAZARDS WITH AFTERNOON SEA BREEZES. && .FIRE WEATHER... RELATIVE HUMIDITIES ARE EXPECTED TO BE QUITE LOW TUESDAY BUT WINDS ARE NOT EXPECTED TO BE AS WINDY AS TODAY. FUELS MAY STILL BE A BIT MOIST AS WELL, BUT THERE MAY BE ENOUGH OF AN ELEVATED FIRE WEATHER CONCERN THAT AN SPS MAY BE NEEDED. WEDNESDAY MAY BE DRY AND BREEZY AGAIN, SO WE WILL NEED TO COORDINATE WITH PARTNERS AGAIN FOR POSSIBLE RED FLAG CONDITIONS IF FUELS HAVE DRIED OUT BY THEN. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FREEZE WARNING UNTIL 8 AM EDT TUESDAY FOR PAZ060>062. FROST ADVISORY UNTIL 8 AM EDT TUESDAY FOR PAZ067>069. NJ...FREEZE WARNING UNTIL 8 AM EDT TUESDAY FOR NJZ007>010. FROST ADVISORY UNTIL 8 AM EDT TUESDAY FOR NJZ012-013-015>022- 027. DE...FROST ADVISORY UNTIL 8 AM EDT TUESDAY FOR DEZ001. MD...FROST ADVISORY UNTIL 8 AM EDT TUESDAY FOR MDZ008-012. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ430-431- 450>455. && $$ SYNOPSIS...SZATKOWSKI NEAR TERM...HAYES SHORT TERM...ROBERTSON LONG TERM...SZATKOWSKI AVIATION...SZATKOWSKI/HAYES MARINE...SZATKOWSKI/HAYES FIRE WEATHER...ROBERTSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
223 PM CDT SUN APR 1 2012 .DISCUSSION... 1005 AM CDT THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS AFTERNOON. IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR 1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM. THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000 J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL- DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION. INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF ANY STORM WERE TO SUSTAIN ITSELF. MTF //PREV DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * PERSISTENT FOG WITH 4-5SM VIS TO LINGER THROUGH THE AFTERNOON AND OVERNIGHT HOURS. * HIGH END MVFR CEILINGS THIS AFTERNOON BEFORE BECOMING VFR THIS EVENING. * NORTHEAST WINDS THIS AFTERNOON AND EVENING BECOMING EAST SOUTHEAST MONDAY MORNING. RODRIGUEZ //DISCUSSION...UPDATED 18Z... A COMPLEX WEATHER PATTERN REMAINS OVER THE TERMINALS EARLY THIS AFTERNOON AS A FRONTAL BOUNDARY IS SITUATED ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. ITS THIS BOUNDARY WHICH IS HELPING TO PROVIDE VARYING SKY AND WEATHER CONDITIONS OVER RATHER SMALL DISTANCES. LOWER CEILINGS WHICH HAVE BEEN SITUATED OVER FAR NORTHERN ILLINOIS AND SOUTHERN WISCONSIN HAVE FINALLY WORKED THEIR WAY SOUTH OVER ALL OF THE TERMINALS...WITH THE EXCEPTION OF GYY AT THIS TIME. WITH THIS SOUTHERLY PUSH...HIGH END MVFR CEILINGS HAVE SHIFTED OVERHEAD AND EXPECT THESE CEILINGS/HEIGHTS TO REMAIN THROUGH THE REMAINDER OF THE AFTERNOON/EARLY EVENING WITH GYY ALSO OBSERVING THESE LOWER CEILINGS THIS AFTERNOON. THE OVERALL EXTENT OF THIS LOW CLOUD COVER HAS BEEN ERODING ON ALL SIDES TODAY AND EXPECT THIS TO CONTINUE AS DRIER AIR TO THE NORTH ADVECTS SOUTH...WITH CEILINGS TO SCATTER/SHIFT OUT OF THE TERMINALS LATER THIS EVENING. WITH THE BOUNDARY OVER THE TERMINALS TODAY...FOG WITH VIS OF 3-5SM HAS BEEN IN PLACE. INITIAL THOUGHTS WERE THAT THIS FOG WOULD SCATTER OUT BY MID DAY...BUT LATEST THINKING HAS SINCE CHANGED WITH LITTLE IF ANY IMPROVEMENT HAS BEEN OBSERVED. NOW THAT THESE LOWER CEILINGS HAVE MOVED OVERHEAD...DONT SEE ANY REASON WHY THE FOG WILL IMPROVE THROUGH THE REMAINDER OF THE AFTERNOON. SO HAVE INCLUDED FOG OF 4-5SM THROUGH THIS AFTERNOON AND EVENING...WITH CONDITIONS TO IMPROVE BY MONDAY MORNING. WINDS WILL HOLD OUT OF THE NORTHEAST THIS AFTERNOON WITH SOME INCREASE IN SPEED...BUT WITH NO PREVAILING GUSTS EXPECTED. THEN WINDS WILL SLOWLY SHIFT TO MORE OF AN EAST SOUTHEAST DIRECTION TONIGHT INTO MONDAY WITH SPEEDS/GUSTS INCREASING THROUGHOUT THE DAY WITH DAY TIME MIXING. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM HIGH CONFIDENCE WITH FOG/VIS TRENDS. * MEDIUM CONFIDENCE WITH CEILINGS/TRENDS THIS AFTERNOON AND EVENING. * HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH CHANCE TSRA. TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. SATURDAY...VFR. MDB && .MARINE... 220 PM CDT LIGHT EAST TO NORTHEAST WINDS WILL BE WITH US THROUGH TUESDAY. A LARGE HIGH PRESSURE IS CURRENTLY OVER HUDSON BAY...AND A SERIES OF LOWS EXTEND FROM SASKATCHEWAN THROUGH THE CENTRAL GREAT PLAINS. AS THE LOWS MOVE EASTWARD EARLY THIS WEEK...THE GRADIENT OVER THE SOUTHERN HALF OF THE LAKE WILL TIGHTEN...BUT WINDS ARE EXPECTED TO BE 25 KT OR LESS THROUGHOUT THE FORECAST. ALTHOUGH WINDS WILL BE LIGHT...AN EXTENDED PERIOD OF EASTERLY WINDS RAISES CONCERNS OF HIGHER WAVES ACROSS THE ILLINOIS NEARSHORE ZONES. NO PLANS TO ISSUE A SMALL CRAFT ADVISORY...BUT WILL MONITOR TRENDS. THE SOUTHERN LOW WEAKENS AS IT PASSES OVER SOUTHERN LAKE MICHIGAN TUESDAY. EXACT TIMING OF WHEN THE LOW WILL PASS OVER THE LAKE IS UNCERTAIN AS THE MODELS SHOW A 6 HOUR DIFFERENCE IN TIMING. THE NORTHERN LOW MOVES EASTWARD INTO NORTHERN ONTARIO...AND ITS COLD FRONT MOVES SOUTHWARD ACROSS THE LAKE TUESDAY. WINDS WILL SHIFT FROM SOUTH TO NORTH BEHIND THE FRONT. HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT LEADING TO ANOTHER PERIOD OF NORTHEAST TO EAST WINDS OF 20 KT OR LESS THROUGH THE END OF THE WEEK. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
114 PM CDT SUN APR 1 2012 .DISCUSSION... 1005 AM CDT THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS AFTERNOON. IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR 1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM. THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000 J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL- DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION. INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF ANY STORM WERE TO SUSTAIN ITSELF. MTF //PREV DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * PERSISTENT FOG WITH 4-5SM VIS TO LINGER THROUGH THE AFTERNOON AND OVERNIGHT HOURS. * HIGH END MVFR CEILINGS THIS AFTERNOON BEFORE BECOMING VFR THIS EVENING. * NORTHEAST WINDS THIS AFTERNOON AND EVENING BECOMING EAST SOUTHEAST MONDAY MORNING. RODRIGUEZ //DISCUSSION...UPDATED 18Z... A COMPLEX WEATHER PATTERN REMAINS OVER THE TERMINALS EARLY THIS AFTERNOON AS A FRONTAL BOUNDARY IS SITUATED ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. ITS THIS BOUNDARY WHICH IS HELPING TO PROVIDE VARYING SKY AND WEATHER CONDITIONS OVER RATHER SMALL DISTANCES. LOWER CEILINGS WHICH HAVE BEEN SITUATED OVER FAR NORTHERN ILLINOIS AND SOUTHERN WISCONSIN HAVE FINALLY WORKED THEIR WAY SOUTH OVER ALL OF THE TERMINALS...WITH THE EXCEPTION OF GYY AT THIS TIME. WITH THIS SOUTHERLY PUSH...HIGH END MVFR CEILINGS HAVE SHIFTED OVERHEAD AND EXPECT THESE CEILINGS/HEIGHTS TO REMAIN THROUGH THE REMAINDER OF THE AFTERNOON/EARLY EVENING WITH GYY ALSO OBSERVING THESE LOWER CEILINGS THIS AFTERNOON. THE OVERALL EXTENT OF THIS LOW CLOUD COVER HAS BEEN ERODING ON ALL SIDES TODAY AND EXPECT THIS TO CONTINUE AS DRIER AIR TO THE NORTH ADVECTS SOUTH...WITH CEILINGS TO SCATTER/SHIFT OUT OF THE TERMINALS LATER THIS EVENING. WITH THE BOUNDARY OVER THE TERMINALS TODAY...FOG WITH VIS OF 3-5SM HAS BEEN IN PLACE. INITIAL THOUGHTS WERE THAT THIS FOG WOULD SCATTER OUT BY MID DAY...BUT LATEST THINKING HAS SINCE CHANGED WITH LITTLE IF ANY IMPROVEMENT HAS BEEN OBSERVED. NOW THAT THESE LOWER CEILINGS HAVE MOVED OVERHEAD...DONT SEE ANY REASON WHY THE FOG WILL IMPROVE THROUGH THE REMAINDER OF THE AFTERNOON. SO HAVE INCLUDED FOG OF 4-5SM THROUGH THIS AFTERNOON AND EVENING...WITH CONDITIONS TO IMPROVE BY MONDAY MORNING. WINDS WILL HOLD OUT OF THE NORTHEAST THIS AFTERNOON WITH SOME INCREASE IN SPEED...BUT WITH NO PREVAILING GUSTS EXPECTED. THEN WINDS WILL SLOWLY SHIFT TO MORE OF AN EAST SOUTHEAST DIRECTION TONIGHT INTO MONDAY WITH SPEEDS/GUSTS INCREASING THROUGHOUT THE DAY WITH DAY TIME MIXING. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM HIGH CONFIDENCE WITH FOG/VIS TRENDS. * MEDIUM CONFIDENCE WITH CEILINGS/TRENDS THIS AFTERNOON AND EVENING. * HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH CHANCE TSRA. TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. SATURDAY...VFR. MDB && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1258 PM CDT SUN APR 1 2012 .DISCUSSION... ISSUED 1040 AM CDT SUN APR 1 2012 PRECIP ASSOCIATED WITH EXITING MCS WELL OFF TO THE EAST LEAVING SUNNY SKIES IN ITS WAKE. TEMPERATURES ARE QUICK TO REBOUND AS WELL...LENDING MORE CONFIDENCE TO THE WARM FORECAST. NEWEST NAM KEEPS AFTERNOON DRY...CONSIDERING THE RAPID RETREAT OF THE SHOWERS THIS MORNING...WILL KEEP ISL WORDING...AND NOT RAISE THE POP THIS AFTERNOON IN THE EAST. MINOR TWEAKS TO HRLY AND POP GRIDS. UPDATE OUT MOMENTARILY. && .AVIATION... ISSUED 1254 PM CDT SUN APR 1 2012 NEW MODELS COMING IN DRY THRU TAF PD. SWRLY/WRLY WINDS COMING AROUND TO SRLY THEN EASTERLY AFTER 06Z TONIGHT AS WEAK BOUNDARY MOVES BACK NORTH. CU THRU THE AFTERNOON SCT OUT AS LLVL STRATUS DEVELOPS WITH MOISTURE TRAPPED IN BOUNDARY LAYER ON RH TIME HEIGHTS. NOT DROPPING CIGS BELOW MVFR HOWEVER...AS PLENTY OF SUNSHINE THIS AFTERNOON MAY COUNTER AND MIX OUT A BIT MORE EFFECTIVELY THAN MOS HINTS. HJS && .PREV DISCUSSION... ISSUED 300 AM CDT SUN APR 1 2012 SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM. SHORT TERM...TODAY THROUGH TUESDAY... LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY... SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY 6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON. BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS. TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S. THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE BOUNDARY IN THE AREA. LONG TERM...WEDNESDAY THROUGH SATURDAY... STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY... WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1122 AM CDT SUN APR 1 2012 .DISCUSSION... 1005 AM CDT THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS AFTERNOON. IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR 1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM. THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000 J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL- DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION. INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF ANY STORM WERE TO SUSTAIN ITSELF. MTF //PREV DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * FOG WITH VIS OF 4-5SM THROUGH LATE MORNING...WITH CONDITIONS IMPROVING BY MID DAY. * VFR CEILINGS SCATTERING OUT BY MID AFTERNOON. * NORTHEAST WINDS STEADILY INCREASING THROUGHOUT THE DAY...WITH SOME GUSTS POSSIBLE IN THE AFTERNOON. RODRIGUEZ //DISCUSSION...UPDATED 12Z... EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS WELL BUT CONFIDENCE IS LOW. NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS. VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE. WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING. MDB //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE OF FOG/VIS TRENDS AND TIMING IMPROVEMENT. * MEDIUM CONFIDENCE WITH CEILING TRENDS THROUGH THE AFTERNOON. * HIGH CONFIDENCE IN WIND SPEED AND DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH CHANCE TSRA. TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. SATURDAY...VFR. MDB && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1051 AM CDT SUN APR 1 2012 .DISCUSSION... ISSUED 1040 AM CDT SUN APR 1 2012 PRECIP ASSOCIATED WITH EXITING MCS WELL OFF TO THE EAST LEAVING SUNNY SKIES IN ITS WAKE. TEMPERATURES ARE QUICK TO REBOUND AS WELL...LENDING MORE CONFIDENCE TO THE WARM FORECAST. NEWEST NAM KEEPS AFTERNOON DRY...CONSIDERING THE RAPID RETREAT OF THE SHOWERS THIS MORNING...WILL KEEP ISL WORDING...AND NOT RAISE THE POP THIS AFTERNOON IN THE EAST. MINOR TWEAKS TO HRLY AND POP GRIDS. UPDATE OUT MOMENTARILY. HJS && .AVIATION... ISSUED 655 AM CDT SUN APR 1 2012...FOR THE 12Z TAFS THE ONLY LINGERING MVFR CONDITIONS ARE IN DEC WITH 5SM BR AT 1145Z. STORMS HAVE MOVE EAST OF CMI...AN NO PRECIP SHOULD AFFECT ANY OF THE TERMINALS FOR MOST OF THE DAY. ACTUALLY...ALL OUR TERMINALS SHOULD BE VFR FOR MOST OF THE NEXT 24 HOURS. FORECAST SOUNDINGS CONFIRM WHAT THE CU RULE IS INDICATING FOR VFR CLOUD REDEVELOPMENT THIS AFTERNOON. THOSE CLOUDS MAY REDUCE HIGH TEMPS A LITTLE, BUT IT WILL STILL BE A VERY WARM DAY. SOME LIGHT MVFR FOG MAY FORM AGAIN LATER TONIGHT...AS A BACK DOOR COLD FRONT DROPS SOUTH INTO CENTRAL IL FROM NORTHERN IL AND N INDIANA. THE PRIMARY FOCUS FOR PRECIP WILL BE IN THE EAST...FOR CMI AND POSSIBLY DEC. WE INTRODUCED A VCSH WITH CB IN CMI AFTER 10Z. WINDS WILL SHIFT FROM SOUTHEAST EARLY IN THE TAF PERIOD TO SOUTHWEST BY MID MORNING. WIND SPEEDS MAY REACH UP NEAR 20KT AT TIMES DURING PEAK MIXING OF LATE MORNING/EARLY AFTERNOON. AS THE COLD FRONT DROPS INTO C IL TONIGHT...WINDS WILL SHIFT EAST- SOUTHEAST AGAIN...REMAINING IN THE 10-13KT RANGE FOR MOST TERMINAL SITES. LIGHT MVFR FOG MAY REDEVELOP LATE TONIGHT...ESPECIALLY FOR OUR NORTHERN TAFS OF PIA/BMI/CMI. MVFR CLOUDS WILL BE POSSIBLE AS WELL. SHIMON && .PREV DISCUSSION... ISSUED 300 AM CDT SUN APR 1 2012 SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM. SHORT TERM...TODAY THROUGH TUESDAY... LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY... SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY 6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON. BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS. TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S. THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE BOUNDARY IN THE AREA. LONG TERM...WEDNESDAY THROUGH SATURDAY... STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY... WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1005 AM CDT SUN APR 1 2012 .DISCUSSION... 1005 AM CDT THE EARLY MORNING STORMS HAVE MOVED QUICKLY SOUTHEAST INTO SOUTHERN INDIANA. IN THEIR WAKE...THEY HELPED TO SINK THE FRONTAL BOUNDARY SOUTH TO NEAR INTERSTATE 88 AT AROUND 10 AM. TO THE NORTH...WHERE STRATUS AND NORTHERLY WINDS PREVAIL...TEMPERATURES HAVE BEEN BASICALLY FLAT LINE. WHILE SOME MIXING OUT OF THE STRATUS MAY OCCUR LATE THIS MORNING...REINFORCING NORTHEAST COLD AIR ADVECTION WILL EVOLVE AS A WEAK LOW SHIFTS EAST ALONG THE FRONTAL BOUNDARY. THIS SCENARIO SHOULD ENABLE THE FRONT TO MOVE SOUTH KEEPING TEMPERATURES COOLER TO THE NORTH...WITH PLACES SEEING A FALL THIS AFTERNOON ESPECIALLY IN THE NEAR DOWNSTREAM OF LAKE MICHIGAN. THE 01.12 NAM CAPTURES THIS TREND WELL...AND SEEMS TO HAVE A DECENT HANDLE ON THE STRATUS EVOLUTION...HINTING AT LOW CLOUDS ALONG AND IMMEDIATELY BEHIND THE BOUNDARY THROUGH THIS AFTERNOON. IT IS A TALE OF TWO DIFFERENT DAYS ACROSS THE CWA AS TO THE SOUTH OF THE FRONT...TEMPERATURES ARE OFF TO THE RACES WITH MID 60S ALREADY AT 10 AM IN PERU AND PONTIAC. A WARM-UP TO AROUND OR JUST ABOVE 80 DEGREES STILL LOOKS WELL IN PLACE...ESPECIALLY SEEING GUSTS TO AROUND 20 KTS ALREADY INDICATING GOOD MIXING AND CONTINUED LOW- LEVEL WARM AIR ADVECTION. THE 12Z ILX RAOB HAD NEAR 1300 J/KG OF MUCAPE WHICH SHOULD BE A GOOD BASELINE FOR WHAT IS SHIFTING OVER THE SOUTHERN FORECAST AREA AS IT CONTINUES TO WARM. THIS LOOKS TO MAXIMIZE/POOL THIS AFTERNOON BETWEEN 1500 AND 2000 J/KG IN THE FAR SOUTH...BUT IN THE ABSENCE OF ANY PRONOUNCED TRIGGER AND A QUICKLY WEAKENING LOW- LEVEL JET. THE WEAK SURFACE CIRCULATION ALONG THE BOUNDARY MAY HELP TO INCREASE CONVERGENCE SOME AS IT SHIFTS EAST THROUGH THE AFTERNOON. ALSO...AN ILL- DEFINED SHORT WAVE RIPPLE IN EASTERN IA IS SHIFTING EAST. TOGETHER IT MIGHT BE ENOUGH TO SPARK ISOLATED THUNDERSTORMS...GENERALLY SOUTH OF U.S. HIGHWAY 24 THIS AFTERNOON. ABOUT ONE THIRD OF EXPLICIT CONVECTIVE GUIDANCE LOOKED AT HAS THAT FORM OF SOLUTION. INSTABILITY PROFILES ARE ENOUGH TO WARRANT MAINLY A HAIL THREAT IF ANY STORM WERE TO SUSTAIN ITSELF. MTF && .PREV DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * FOG WITH VIS OF 3-5SM THROUGH LATE MORNING...WITH CONDITIONS IMPROVING BY MID DAY. * POTENTIAL REMAINING FOR A PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID AFTERNOON. * NORTHEAST WINDS STEADILY INCREASING THROUGHOUT THE DAY...WITH SOME GUSTS POSSIBLE IN THE AFTERNOON. RODRIGUEZ //DISCUSSION...UPDATED 12Z... EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS WELL BUT CONFIDENCE IS LOW. NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS. VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE. WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING. MDB //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM HIGH CONFIDENCE OF FOG/VIS TRENDS WITH MEDIUM CONFIDENCE OF TIMING IMPROVEMENT. * LOW MEDIUM CONFIDENCE OF A PERIOD OF 1500-2000 FT CEILINGS LATE MORNING INTO THIS AFTERNOON. * HIGH CONFIDENCE IN WIND SPEED AND DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH CHANCE TSRA. TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. SATURDAY...VFR. MDB && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
912 AM CDT SUN APR 1 2012 .DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * FOG WITH VIS OF 3-5SM THROUGH LATE MORNING...WITH CONDITIONS IMPROVING BY MID DAY. * POTENTIAL REMAINING FOR A PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID AFTERNOON. * NORTHEAST WINDS STEADILY INCREASING THROUGHOUT THE DAY...WITH SOME GUSTS POSSIBLE IN THE AFTERNOON. RODRIGUEZ //DISCUSSION...UPDATED 12Z... EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS WELL BUT CONFIDENCE IS LOW. NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS. VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE. WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING. MDB //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM HIGH CONFIDENCE OF FOG/VIS TRENDS WITH MEDIUM CONFIDENCE OF TIMING IMPROVEMENT. * LOW MEDIUM CONFIDENCE OF A PERIOD OF 1500-2000 FT CEILINGS LATE MORNING INTO THIS AFTERNOON. * HIGH CONFIDENCE IN WIND SPEED AND DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH CHANCE TSRA. TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. SATURDAY...VFR. MDB && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
655 AM CDT SUN APR 1 2012 .DISCUSSION... ISSUED 300 AM CDT SUN APR 1 2012 SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM. SHORT TERM...TODAY THROUGH TUESDAY... LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY... SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY 6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON. BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS. TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S. THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE BOUNDARY IN THE AREA. LONG TERM...WEDNESDAY THROUGH SATURDAY... STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY... WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY. GEELHART && .AVIATION... ISSUED 655 AM CDT SUN APR 1 2012...FOR THE 12Z TAFS THE ONLY LINGERING MVFR CONDITIONS ARE IN DEC WITH 5SM BR AT 1145Z. STORMS HAVE MOVE EAST OF CMI...AN NO PRECIP SHOULD AFFECT ANY OF THE TERMINALS FOR MOST OF THE DAY. ACTUALLY...ALL OUR TERMINALS SHOULD BE VFR FOR MOST OF THE NEXT 24 HOURS. FORECAST SOUNDINGS CONFIRM WHAT THE CU RULE IS INDICATING FOR VFR CLOUD REDEVELOPMENT THIS AFTERNOON. THOSE CLOUDS MAY REDUCE HIGH TEMPS A LITTLE, BUT IT WILL STILL BE A VERY WARM DAY. SOME LIGHT MVFR FOG MAY FORM AGAIN LATER TONIGHT...AS A BACK DOOR COLD FRONT DROPS SOUTH INTO CENTRAL IL FROM NORTHERN IL AND N INDIANA. THE PRIMARY FOCUS FOR PRECIP WILL BE IN THE EAST...FOR CMI AND POSSIBLY DEC. WE INTRODUCED A VCSH WITH CB IN CMI AFTER 10Z. WINDS WILL SHIFT FROM SOUTHEAST EARLY IN THE TAF PERIOD TO SOUTHWEST BY MID MORNING. WIND SPEEDS MAY REACH UP NEAR 20KT AT TIMES DURING PEAK MIXING OF LATE MORNING/EARLY AFTERNOON. AS THE COLD FRONT DROPS INTO C IL TONIGHT...WINDS WILL SHIFT EAST- SOUTHEAST AGAIN...REMAINING IN THE 10-13KT RANGE FOR MOST TERMINAL SITES. LIGHT MVFR FOG MAY REDEVELOP LATE TONIGHT...ESPECIALLY FOR OUR NORTHERN TAFS OF PIA/BMI/CMI. MVFR CLOUDS WILL BE POSSIBLE AS WELL. SHIMON && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
647 AM CDT SUN APR 1 2012 .DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * SHRA/TSRA EXITING TO THE EAST 12-13Z. * FEW-SCT IFR LEVEL CLOUDS POSSIBLE NEXT HOUR OR SO...ESPECIALLY AT MDW. * MVFR MIST/HAZE EXPECTED TO CONTINUE THROUGH THE MORNING. * LIGHT/VARIABLE SOUTH/SOUTHWEST WINDS SHIFTING TO NORTHEAST BY LATE MORNING/MID-DAY. * POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID-AFTERNOON. MDB //DISCUSSION...UPDATED 12Z... EXPECT SOME RATHER VARIABLE CONDITIONS THROUGH EARLY AFTERNOON IN TERMS OF WINDS/CIGS/VSBY. CURRENTLY...SHRA/TSRA ACTIVITY ACROSS FAR NE IL IS MOVING INTO NW IN AND WILL EXIT TO THE EAST OF GYY TOWARD 14Z. NEXT CONCERNS ARE RELATED TO WEAK LOW PRESSURE WHICH WILL MOVE ALONG A FRONTAL BOUNDARY EXTENDING FROM NEAR KCID TO KRPJ TO JUST NORTH OF KPWK THIS MORNING. THIS FRONT IS EXPECTED TO SAG SOUTHWARD THROUGH THE MORNING BRINGING WINDS TO THE NORTHEAST ACROSS THE CHI AND NW IN TERMINALS...WITH RFD ALREADY SEEING NE WINDS. AS THE FRONT MOVES WINDS WILL LIKELY BECOME LIGHT AND VARIABLE WITH A SOUTH TO WEST DIRECTION. GIVEN THE RAINFALL THIS MORNING AND THE LIGHT WIND REGIME EXPECT THAT MVFR VSBY WILL PREVAIL...WITH SOME IFR TOWARDS DPA AND RFD...THROUGH AT LEAST MID MORNING AND POSSIBLY LONGER. IN ADDITION...FORECAST SOUNDINGS CONTINUE TO SHOW DEVELOPMENT OF MVFR LEVEL STRATUS DECK BY MIDDAY WHICH WOULD THEN SCATTER LATER THIS AFTERNOON. THIS SEEMS PLAUSIBLE GIVEN THE SHIFT TO A COOLER NORTHEASTERLY FLOW OFF THE LAKE AND THE ABUNDANT LOW LEVEL MOISTURE ALREADY IN PLACE. THERE IS A CHANCE THAT MIST/HAZE WILL CONTINUE THROUGH THE AFTERNOON AS WELL BUT CONFIDENCE IS LOW. NORTHEAST WINDS WILL TURN EASTERLY TONIGHT AS RIDGING BUILDS TO THE EAST AND LOW PRESSURE TAKES SHAPE ACROSS THE CENTRAL PLAINS. VFR SHOULD PREVAIL BUT SOME MVFR VSBY REDUCTION IS POSSIBLE LATE. WINDS WILL THEN TURN MORE SOUTHEASTERLY MONDAY MORNING. MDB //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN SHRA/TSRA ACTIVITY EXITING TO THE EAST 12-13Z. * MEDIUM-HIGH CONFIDENCE THAN FEW-SCT IFR LEVEL CLOUDS WILL BE SHORT LIVED THIS MORNING...CANNOT RULE OUT BRIEF BKN COVERAGE BUT PROBABILITY IS LOW. * MEDIUM CONFIDENCE IN MVFR MIST/HAZE CONTINUING FOR AT LEAST A FEW HOURS...LOW CONFIDENCE ON TIMING OF IMPROVEMENT. * HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD AND THAT THERE WILL LIKELY BE SOME VARIABILITY IN WIND DIRECTION THROUGH MID MORNING. * MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO THIS AFTERNOON. MDB //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...VFR WITH CHANCE TSRA. TUESDAY...VFR WITH CHANCE SHRA/TSRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. SATURDAY...VFR. MDB && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
406 AM CDT SUN APR 1 2012 .DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * SCATTERED BANDS OF TSRA APPROACHING FROM THE WEST AROUND 10Z. INTERMITTENT TSRA EXPECTED UNTIL AROUND 12Z...POSSIBLY LINGERING TIL 13-14Z IF NEW DEVELOPMENT ON THE REAR FLANK. * WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY. WINDS MAY BECOME LIGHT AND VARIABLE FOR A FEW HOURS AS THIS OCCURS. * POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID-AFTERNOON. MDB //DISCUSSION...UPDATED 09Z... BAND OF CLUSTERED SHRA/TSRA CONTINUES TO MOVE EASTWARD INTO THE FAR WESTERN CHI METRO AREA AT 09Z. THIS WILL CONTINUE TO MOVE EASTWARD OVER THE NEXT SEVERAL HOURS BRINGING BRIEF HEAVY DOWNPOURS AND IFR/MVFR VSBY. SOME ADDITIONAL DEVELOPMENT MAY OCCUR IMMEDIATELY BEHIND THE CURRENT BAND PROLONGING THE DURATION SOMEWHAT. MDB FROM 06Z... INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD 09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION PARTICULARLY FOR KRFD. ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY MID-LATE AFTERNOON TO SCATTER CLOUDS. WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE. AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER MIXING WITH LOW LEVEL COLD ADVECTION. RATZER //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN TSRA AFFECTING THE IMMEDIATE TERMINAL AREAS APPROX 10-12Z...WITH LOW CONFIDENCE IN POTENTIAL FOR NEW DEVELOPMENT IMMEDIATELY BEHIND CURRENT ACTIVITY PROLONGING IMPACT. * HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD. * MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO THIS AFTERNOON. MDB //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT. TUESDAY...VFR WITH CHANCE SHRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. RATZER && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 AM CDT SUN APR 1 2012 .DISCUSSION... 315 AM CDT THIS MORNING HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL PUSH EASTWARD WITH FRONTAL BOUNDARY SLOWLY TRYING TO LIFT NORTHWARD THROUGH THE EARLY MORNING HOURS. ONGOING ELEVATED CONVECTION ON NOSE OF LOW LEVEL JET WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION RIDING H5 HEIGHTS DOWN THE RIDGE ALONG THE INSTABILITY GRADIENT. SEVERE THREAT THROUGH THE PREDAWN HOURS WILL REMAIN MARGINAL...BUT LATEST RUC CONTINUES TO SHOW NEAR 1000 J/KG GENERALLY ALONG AND WEST OF THE I39 CORRIDOR SUPPORTING AT LEAST SOME THREAT FOR HAIL. THREAT SHOULD TAPER THROUGH DAYBREAK THIS MORNING AS LOW LEVEL JET VEERS AND THETA E ADVECTION WEAKENS. MEANWHILE...WEAK AREA OF LOW PRESSURE NEAR LAKE SUPERIOR WILL PUSH EAST INTO SOUTHEASTERN ONTARIO BY EARLY THIS AFTERNOON. GUIDANCE SUGGESTS BAROCLINIC ZONE WILL BE FARTHER SOUTH/WEST THAN ORIGINALLY ANTICIPATED THUS BUMPED DOWN TEMPERATURES SLIGHTLY ACROSS THE AREA FOR THIS AFTERNOON. IN ADDITION WINDS TURNING TO THE NORTHEAST BY MID MORNING IN RESPONSE TO LOW MOVING ACROSS ONTARIO WILL LIMIT HIGH TEMPS ALONG THE LAKE SHORE...WITH TEMPERATURES FALLING INLAND THROUGH THE AFTERNOON AS MARINE LAYER SPREADS INLAND. MONDAY...GUIDANCE CONTINUES TO STRUGGLE WITH PLACEMENT OF BAROCLINIC ZONE/LOW PRESSURE. A LARGE TEMPERATURE SPREAD IS STILL EXPECTED TO SET UP ACROSS THE CWA. MAJORITY OF GUIDANCE SHOWS SOUTHWEST PORTIONS OF THE CWA TRYING TO REACHING THE 80 MARK...BUT WARMER TEMPERATURES ARE NOW EXPECTED TO BE FARTHER WEST. ALSO HAD TO DROP TEMPERATURES ALONG THE LAKE FRONT SEVERAL DEGREES AS LATEST GUIDANCE IN GENERAL SUGGESTS 60S POSSIBLY EVEN 50S AS WE STAY UNDER SOUTHEAST FLOW THROUGH THE DAY WITH WINDS OFF THE LAKE IN ILLINOIS. AM CONCERNED TEMPS ARE STILL A LITTLE HIGH THOUGH FOR MONDAY ALONG THE ILLINOIS SHORES. TUESDAY THOUGH SATURDAY...COLD FRONT WILL SWEEP ACROSS THE REGION TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. BROAD AREA OF HIGH PRESSURE BUILDS ACROSS THE CANADIAN PRAIRIES EAST TOWARDS THE GREAT LAKE REGION THROUGH THE END OF THE WEEK. NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL BE IN AREA OF NORTHERLY FLOW AND EXPECT TO BE CLIPPED BY COOLER AIR ALOFT //H85 TEMPS FALLING TO AROUND -3C THURSDAY// BEHIND THE COLD FRONT. SHOULD SEE PLENTY OF SUNSHINE FOR THE LATTER HALF OF THE WEEK. TEMPERATURES WILL CONTINUE TO RUN SLIGHTLY ABOVE NORMAL...BUT SHOULD BE MORE SEASONABLE WITH HIGHS IN THE UPPER 50S TO LOW 60S AND LOWS IN THE UPPER 30S TO LOW 40S. BMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * COVERAGE/TIMING OF THUNDERSTORMS EARLY THIS MORNING. * WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY. * POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID-AFTERNOON. RATZER //DISCUSSION...UPDATED 06Z... INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD 09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION PARTICULARLY FOR KRFD. ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY MID-LATE AFTERNOON TO SCATTER CLOUDS. WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE. AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER MIXING WITH LOW LEVEL COLD ADVECTION. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE THUNDERSTORMS WILL AFFECT TRACON AIRSPACE...BUT MEDIUM CONFIDENCE IN DIRECT IMPACT ON INDIVIDUAL TERMINALS. * HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD. * MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO THIS AFTERNOON. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT. TUESDAY...VFR WITH CHANCE SHRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. RATZER && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
302 AM CDT SUN APR 1 2012 .DISCUSSION... ISSUED 300 AM CDT SUN APR 1 2012 SMALL MCS FORMED AS EXPECTED OVER EASTERN IOWA LATE IN THE EVENING...AND HAS BEEN MOVING ACROSS THE NORTHERN CWA OVERNIGHT...PRODUCING SEVERE HAIL AT TIMES. HAVE SEEN SOME SHOWERS/STORMS AS FAR SOUTH AS LINCOLN AT 2 AM. SHORT TERM...TODAY THROUGH TUESDAY... LATEST HRRR MODEL...WHICH HAS A GOOD HANDLE ON THE ACTIVITY... SHOWS MUCH OF THE RAIN SHOULD LARGELY BE OUT OF THE CWA BY SUNRISE. WILL MAKE A LAST MINUTE DECISION ON HOW LONG TO LINGER IT THIS MORNING. ONCE THAT CLEARS OUT...TEMPERATURES BECOME THE PRIMARY FOCUS. STILL LOOKING FOR HIGHS IN THE 80S ACROSS THE ENTIRE AREA...CLOSE TO THE DAILY RECORDS. HOWEVER...EVENING MODEL RUNS SHOWING A FRONTAL BOUNDARY NEAR THE I-80 CORRIDOR WILL LIKELY SLIP A BIT SOUTHWARD THIS AFTERNOON...DRIVEN BY A RATHER STIFF NORTHEAST FLOW. IF IT SLIPS TOO FAR...THEN TEMPERATURES ACROSS THE NORTHEAST CWA MAY END UP BEING COOLER THAN EXPECTED. WRF MODEL OUT OF WFO CHICAGO HAS THE BOUNDARY ALMOST ALL THE WAY TO I-74 BY 6 PM. WILL NEED TO WATCH THIS CLOSELY DURING THE AFTERNOON. BOUNDARY WILL PROBABLY REACH AT LEAST INTO PART OF THE CWA THIS EVENING...BEFORE BEGINNING TO RETREAT. SAME PROBLEM EXISTS WITH TEMPERATURES MONDAY AFTERNOON...DUE TO ITS POSITION. HAVE PULLED HIGH TEMPERATURES DOWN A BIT NORTH OF I-74...BUT STILL GOING A FEW DEGREES ABOVE GUIDANCE IN THAT AREA. REMAINDER OF THE CWA MORE LIKELY TO REACH THE 85-90 DEGREE RANGE...AGAIN NEAR THE RECORDS. TIMING OF COLD FRONTAL PASSAGE TUESDAY MORNING APPEARS TO HAVE SLOWED A BIT FROM EARLIER RUNS...SO HAVE KEPT TEMPERATURES SOUTH OF I-70 WARMER THAN PREVIOUSLY FORECAST...WITH LOWER 80S. THREAT OF SHOWERS/STORMS TO CONTINUE INTO THE AFTERNOON WITH THE BOUNDARY IN THE AREA. LONG TERM...WEDNESDAY THROUGH SATURDAY... STILL LOOKING TO BE MUCH COOLER THAN THE START OF THE WEEK...ALTHOUGH STILL A BIT ABOVE NORMAL. FOCUS IN THIS PERIOD REMAINS WITH A CUTOFF LOW WHICH WILL DEVELOP OVER THE SOUTHERN ROCKIES EARLY IN THE WEEK. LONGER RANGE MODELS IN REASONABLE AGREEMENT WITH A TRACK THAT TAKES IT SOUTH OF THE OHIO VALLEY...BUT WILL STILL SEE THE RAIN SHIELD ON THE NORTHERN FLANK EXTEND WELL TO THE NORTH. HAVE CUT BACK ON THE RAIN ACROSS THE NORTHERN CWA FOR WEDNESDAY/THURSDAY... WITH THE PERSISTENT NORTHEAST FLOW BRINGING DRIER AIR INTO CENTRAL ILLINOIS. MAINLY DRY CONDITIONS EXPECTED LATE IN THE WEEK...AS A NARROW RIDGE OF HIGH PRESSURE MOVES INTO THE MISSISSIPPI VALLEY. GEELHART && .AVIATION... ISSUED 1240 AM CDT SUN APR 1 2012...FOR THE 06Z TAFS STORMS WILL PUSH ACROSS PIA/BMI/CMI BETWEEN 06Z AND 09Z...WITH MVFR VIS IN HEAVY RAIN AND SMALL HAIL. BASED ON UPSTREAM OBS DURING STORMS...CIGS SHOULD REMAIN VFR DURING THE STORMS. WIND GUSTS UP TO 35 MPH ARE POSSIBLE. LIGHTER RAIN AND MORE ISOLATED THUNDERSTORMS ARE PROJECTED TO REACH THE SOUTHERN TERMINALS OF SPI/DEC. STILL BRIEF PERIODS OF MVFR VIS IN RAIN IS POSSIBLE. WE DID NOT INCLUDE TEMPOS FOR MVFR AT SPI/DEC WITH THE INITIAL ISSUANCE...AS WE EXPECT THE LINE OF STORMS TO WEAKEN AS IT PROGRESSES FARTHER FROM THE FAVORABLE WIND SHEAR...LLJ...AND INSTABILITY. SKIES ARE EXPECTED TO CLEAR RELATIVELY QUICKLY BEHIND THE LINE OF SHOWERS/STORMS. A PERIOD OF MVFR VIS IN FOG MAY DEVELOP IN PIA/BMI/CMI IF ANY CLEARING DEVELOPS BEFORE SUNRISE. FOG WOULD CLEAR TO VFR BY 15Z IN THAT SCENARIO. WINDS WILL VEER FROM SOUTHEAST TO SOUTHWEST BETWEEN 10Z-14Z...THEN REMAIN SOUTHWEST UNTIL A BACK DOOR COLD FRONT REACHES NEAR PIA/BMI/CMI TOWARD 06Z. THEN WINDS WILL BACK TO THE EAST BEHIND THAT FRONT. SHIMON && .CLIMATE... ISSUED 218 AM CDT SUN APR 1 2012 RECORD HIGHS FOR TODAY...MONDAY... BLOOMINGTON......82/1981...85/1903 CHAMPAIGN........83/1946...81/1932 DECATUR..........87/1946...85/1940 EFFINGHAM........83/1986...82/2010 JACKSONVILLE.....85/1946...85/1903 LINCOLN..........85/1946...84/1940 OLNEY............85/1946...85/1940 PEORIA...........83/1946...84/1940 SPRINGFIELD......87/1946...87/1981 GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
214 AM CDT SUN APR 1 2012 .DISCUSSION... 908 PM CDT SOME MINOR CHANGES TO POPS AND WX FOR TONIGHT. MAINLY DELAYING ARRIVAL OF THREAT OF SHRA AND TSRA UNTIL LATER TONIGHT AND REDUCING POPS OVER FAR NE IL FOR OVERNIGHT. RADAR COMPOSITE SHOWS WEAK ECHOES TO THE W THRU N OF THE LOCAL AREA WHERE INITIAL WAA AND RESULTING UVV AT MAINLY MID LEVELS OCCURRING. EXPECT THESE ECHOES...ALREADY MOSTLY VIRGA UPSTREAM WITH FEW IF ANY METARS REPORTING ANY PRECIP...WILL CONTINUE TO DRY UP AS THEY MOVE INTO INCREASINGLY DRY MID AND LOW LEVELS. A THUNDERSTORM DEVELOPED JUST NE OF DSM AROUND 0030Z AND ARE SLOWLY INCREASING IN NUMBER AS THEY MOVE ENE-E. THESE TSRA ARE WHERE BETTER MOISTURE IN THE 850 TO 800 HPA LAYER IS IN PLACE...WHERE WEAK SURFACE CONVERGENCE IS OCCURRING...WHERE NOSE OF 45 KT SOUTHWESTERLY JET AT 5 TO 6 K FT AGL SHOWN BY KDMX VAD WIND PROFILE IS LOCATED...AND JUST AHEAD OF WEAK MID LEVEL SHORT WAVE TROF MOVING OVER CENTRAL IA. CHALLENGE TO FORECAST IS HOW EXTENSIVE FURTHER TSRA DEVELOPMENT WILL BE AND WHERE AREA OF STORMS IS LIKELY TO MOVE OVERNIGHT. LATEST RUC13 RUN INDICATES A RATHER SMALL AREA OF MID LEVEL ISENTROPIC LIFT CURRENTLY OVER CENTRAL IA MOVES THIS AREA EASTWARD TO E CENTRAL IA 04-06Z...AND THEN SOUTHEASTWARD ACROSS N CENTRAL IL TO THE CENTRAL IL-IND BORDER BY 12Z. THIS APPEARS TO BE BEST TRACK FOR THE ELEVATED TSRA THAT IS EXPECTED TO BE MAINTAINED THROUGH THE OVERNIGHT BY THE LLJ...THE MID LEVEL SHORT WAVE AND STEEPENING MID LEVEL LAPSE RATES. EXPECT RATHER SMALL AREA OF TSRA AS MOISTURE WILL BE MARGINAL SO ONLY ANTICIPATE ACTIVITY WHERE FORCING FACTORS ARE MAXIMIZED DURING THE OVERNIGHT. TRS //PREV DISCUSSION... 317 PM CDT MAIN FORECAST ISSUES/CONCERNS FOR THE REMAINDER OF THE WEEKEND ARE WITH CHANCES FOR SHOWERS/THUNDERSTORMS LATE TONIGHT INTO SUNDAY MORNING...AS WELL AS TEMPERATURE TRENDS SUNDAY. WITH THE LOW LEVEL CLOUD COVER TODAY MASKING THE FACT THAT HIGH PRESSURE IS OVERHEAD...RELATIVELY QUIET CONDITIONS HAVE BEEN IN PLACE FOR ALL OF TODAY. ALTHOUGH...OVER THE LAST COUPLE OF HOURS SEVERAL HOLES DEVELOPED WITHIN THIS LOW LEVEL MOISTURE. A WARM SUN AND DRIER AIR ALOFT HAS ALLOWED FOR THESE HOLES TO CONTINUE TO EXPAND WITH SOME AREAS ACROSS THE SOUTHERN CWA OBSERVING SUNNY TO PARTLY CLOUDY SKIES. WITHIN THESE AREAS OF BETTER SOLAR INSOLATION...TEMPS HAVE QUICKLY RISEN INTO THE 50S WITH SOME AREAS OBSERVING SOME PLEASANT CONDITIONS AS RATHER LIGHT FLOW REMAINS IN PLACE. EXPECT THIS LOW CLOUD SHIELD TO CONTINUE TO ERODE WITH TIME LATE THIS AFTERNOON AND EARLY EVENING BUT WITH SOME MID AND HIGH LEVEL CLOUD COVER TO PUSH OVERHEAD. THIS IN ITSELF SHOULD PROVIDE PARTLY CLOUDY SKIES FOR TONIGHT...BUT WITH PRECIP CHANCES LATER TONIGHT TO POSSIBLY BRING MORE CLOUDY CONDITIONS MORE TOWARDS EARLY SUNDAY MORNING. LATEST GUIDANCE CONTINUES TO INDICATE SHOWERS AND THUNDERSTORMS DEVELOPING TONIGHT ACROSS EASTERN IOWA AND SHIFTING EAST/SOUTHEAST ACROSS A PORTION OF THE CWA THROUGH SUNDAY MORNING. ALL GUIDANCE IS INDICATING THIS POSSIBILITY BUT WITH SOME VARIABILITY STILL REMAINING WITH REGARDS TO EXACT TIMING AND PLACEMENT/TRACK. WITH BACKING 850MB FLOW...A WARMER AND MORE MOIST AIR MASS LOCATED ACROSS THE CENTRAL PLAINS WILL ADVECT NORTH/NORTHEAST WITH TIME TONIGHT BRINGING HIGHER DEW POINT AIR TO THE REGION. NORTHWEST FLOW ALOFT WILL STEER A MID LEVEL IMPULSE AND ATTENDANT SURFACE TROUGH OUT OF THE NORTHERN PLAINS THIS EVENING...AND HELP TO INITIATE CONVECTION ALONG A LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE REGION. WITH LOW LEVEL FLOW FEEDING HIGHER THETA E AIR OVER THIS BOUNDARY AND INTO ANY DEVELOPING PRECIP...THIS AREA OF CONVECTION COULD SEE SOME EXPANSION IN COVERAGE AS IT SHIFTS EAST/SOUTHEAST THROUGH THE CWA EARLY SUNDAY MORNING. ALTHOUGH...GUIDANCE CONTINUES TO STRUGGLE WITH EXACT TIMING OF WHEN CONVECTION WILL DEVELOP AND WHERE THIS DEVELOPING AREA OF PRECIPITATION WILL PROGRESS THROUGH. DUE TO THIS UNCERTAINTY STILL IN PLACE...HAVE NOT MADE MANY CHANGES TO THE GOING POP GRIDS FOR TONIGHT KEEPING HIGH CHANCE POPS FOR MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME THROUGH MID MORNING SUNDAY. THIS IS BASED ON THE LIKELIHOOD THAT CONVECTION SHOULD BEGIN TO DEVELOP OVER IOWA ONCE WE DECOUPLE AND THE LLJ RAMPS UP...WHICH SHOULD BE AROUND THE 3Z-6Z TIME FRAME. SOME HI RES DATA IS SHOWING THE POSSIBILITY OF AN MCS DEVELOPING AND QUICKLY SHIFTING THROUGH THE REGION SUNDAY MORNING. HAVE NOT COMPLETELY THROWN THIS OUT AS A POSSIBILITY...WITH DECENT LOW LEVEL SHEAR TO BE PRESENT ACROSS THE REGION. A LIMITING FACTOR WILL BE THE AMOUNT OF INSTABILITY PRESENT OVER NORTHERN ILLINOIS AND NORTHWEST...WHICH AM CURRENTLY LEANING MORE ON THE SREF MUCAPE OUTPUT WHICH IS SHOWING WEAKER INSTABILITY PRESENT BY EARLY SUNDAY MORNING LIMITING MORE ROBUST CONVECTION...WITH OTHER GUIDANCE OF COURSE ALSO VARYING TO THIS AMOUNT. SO WITH ANY PRECIP WHICH MOVES THROUGH THE AREA LATE TONIGHT AND EARLY SUNDAY MORNING...A MORE LIKELY SCENARIO WILL BE FOR THIS TO BE AN UNORGANIZED AREA OF SHOWERS AND ELEVATED THUNDERSTORMS WITH LITTLE CHANCES FOR SEVERE WEATHER...HAIL/WIND. ONLY AN ISOLATED THREAT OF HAIL COULD BE OBSERVED MAINLY FOR THE WESTERN CWA WHERE BETTER INSTABILITY AND STRONGER EFFECTIVE BULK SHEAR WILL RESIDE. EVEN IF A MORE ORGANIZED MCS COULD DEVELOP...WOULD EXPECT IT TO FOLLOW THE HIGHER SURFACE DEW POINT AIR AND BETTER INSTABILITY WHICH WOULD MORE THAN LIKELY BE SITUATED TO THE SOUTH OF THE CWA. THUS...ONCE AGAIN KEEPING ANY THREAT FOR SEVERE WEATHER JUST OUTSIDE OF THE CWA. THIS SITUATION WARRANTS CONTINUED MONITORING...AND WILL MAINTAIN A MENTION FOR THE CHANCES FOR THUNDERSTORMS TONIGHT IN THE HWO. ANY LINGERING SHOWERS/THUNDERSTORMS SHOULD EXIT THE CWA BY MID DAY WITH PARTLY CLOUDY TO SUNNY CONDITIONS EXPECTED THROUGH THE AFTERNOON. THE EXTENT OF THE MORNINGS PRECIP WILL DEFINITELY PLAY A KEY ROLE WITH MAX TEMPS ON SUNDAY WITH PERSISTENT WAA ADVECTING A WARMER AIR MASS OVERHEAD. AS SURFACE WARM FRONT TRIES TO LIFT NORTHEAST ACROSS THE CWA DURING THE DAY SUNDAY...IT WILL ACTUALLY BEGIN TO RETREAT AS A COLD FRONT WITH COOLER LOW LEVEL AIR WORKING ITS WAY BACK WEST ACROSS THE CWA LATE IN THE AFTERNOON AND EARLY EVENING. SO OUTSIDE OF PRECIP TRENDS POSSIBLY AFFECTING TEMP TRENDS SUNDAY...PLACEMENT OF THIS BOUNDARY AND MOVEMENT WILL BE KEY IN DEFINING MAX TEMPS FOR SUNDAY. DID BRING DOWN TEMPS A TAD FROM GOING FORECAST BUT HAVE KEPT THE WEST/SOUTHWEST CWA WARMER THAN THE EAST WITH AREAS STILL TO POSSIBLY REACH THE 80 MARK...AND AREAS ACROSS THE EASTERN CWA TO REACH THE LOWER 70S WITH 60S EXPECTED FOR AREAS NEAR THE LAKE. HAVE ADDED SLIGHT CHANCE POPS FOR THE SOUTHEAST PORTION OF THE CWA FOR SUNDAY AFTERNOON WHERE BETTER FOCUS AND UPPER LEVEL SUPPORT COULD PROVIDE FOR DEVELOPMENT OF THUNDERSTORMS. STRONG UPPER LEVEL RIDGING WILL OCCUR ON MONDAY WITH MID AND UPPER LEVEL FLOW BECOMING RATHER WEAK. THIS WEAK FLOW COINCIDING WITH A FORECASTED CLOSED UPPER LEVEL LOW TRACKING THROUGH THE SOUTHERN US WILL PROVIDE A TRICKY FORECAST THROUGH THE REMAINDER OF THE WEEK WITH THE ANTICIPATION FOR GUIDANCE TO CONTINUE TO STRUGGLE WITH PLACEMENT OF LOW LEVEL FEATURES AND INEVITABLE PRECIP. ALTHOUGH...THERE DOES APPEAR TO BE BETTER CHANCES FOR OBSERVING CONVECTION MONDAY NIGHT. BETTER FORCING AS WELL AS INSTABILITY LOOK TO BE IN PLACE FOR THE DEVELOPMENT OF POSSIBLY MORE ORGANIZED CONVECTION...WITH CURRENT GUIDANCE INDICATING BETTER CHANCES RESIDING ACROSS NORTHERN ILLINOIS INTO EARLY TUESDAY MORNING. HAVE NOT GONE OVERLY EXCITED WITH POPS DURING THIS TIME FRAME AS THE ECMWF REMAINS THE OUTLIER KEEPING A SURFACE LOW AND FORCING/PRECIP OFF TO THE WEST FOR MOST OF MONDAY AND MONDAY NIGHT. IF THIS WERE TO COME INTO FRUITION...THAN DRIER CONDITIONS WOULD BE OBSERVED MONDAY NIGHT WITH PRECIP DELAYED UNTIL TUESDAY. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * COVERAGE/TIMING OF THUNDERSTORMS EARLY THIS MORNING. * WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY. * POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID-AFTERNOON. RATZER //DISCUSSION...UPDATED 06Z... INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD 09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION PARTICULARLY FOR KRFD. ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY MID-LATE AFTERNOON TO SCATTER CLOUDS. WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE. AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER MIXING WITH LOW LEVEL COLD ADVECTION. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE THUNDERSTORMS WILL AFFECT TRACON AIRSPACE...BUT MEDIUM CONFIDENCE IN DIRECT IMPACT ON INDIVIDUAL TERMINALS. * HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD. * MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO THIS AFTERNOON. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT. TUESDAY...VFR WITH CHANCE SHRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. RATZER && .MARINE... 210 AM CDT HIGH PRESSURE OVER OHIO EXTENDS NORTHEASTWARD ACROSS THE ST. LAWRENCE VALLEY THIS MORNING WHILE A COMPLEX SERIES OF WEAK LOW PRESSURE SYSTEMS ARE NOTED FROM LAKE SUPERIOR INTO THE MID MISSISSIPPI RIVER VALLEY...WITH BETTER ORGANIZED LOW PRESSURE IN THE LEE OF THE ROCKIES. ONE LOW...OVER LAKE SUPERIOR...WILL MOVE SOUTHEASTWARD TODAY AND MOVE OFF THE EAST COAST THIS EVENING WHERE IT WILL DEEPEN. ANOTHER AREA OF LOW PRESSURE OVER WESTERN IOWA WILL DRIFT EAST WITH A COOL FRONTAL BOUNDARY SETTING UP FROM THE FIRST LOW INTO THIS WEAKER LOW. HIGH PRESSURE WILL THEN SPREAD SOUTHWARD FROM HUDSON BAY AND INTO THE GREAT LAKES BEHIND THE LOW. AS A RESULT OF THIS FAIRLY COMPLEX PATTERN SOUTHERLY WINDS IN PLACE ACROSS LAKE MICHIGAN THIS MORNING WILL TURN NORTHEASTERLY TODAY AND EASTERLY TONIGHT...BEFORE BECOMING SOUTHEAST FOR MONDAY. IT APPEARS THAT THERE WILL BE SEVERAL PERIODS OF STRONGER WINDS FROM TONIGHT THROUGH TUESDAY AS THE PRESSURE GRADIENT MODULATES BETWEEN SYSTEMS. THE FIRST INCREASE SHOULD OCCUR TONIGHT ACROSS CENTRAL AND SOUTHERN PARTS OF THE LAKE WITH GUSTS TO AROUND 25 KT EXPECTED. SPEEDS LOOK TO EASE SOMEWHAT MONDAY BEFORE INCREASING AGAIN MONDAY EVENING THEN DROPPING OFF TUESDAY MORNING AS A LOW PASSES JUST TO THE SOUTH. THE GRADIENT TIGHTENS BEHIND THE LOW TUESDAY AFTERNOON AS STRONG HIGH PRESSURE SPREADS INTO THE UPPER MISSISSIPPI RIVER VALLEY. THIS LOOKS TO BE THE PERIOD OF STRONGEST WINDS WITH 30 KT POSSIBLE FROM THE NORTH. THE HIGH THEN GRADUALLY SPREADS EASTWARD KEEPING ITS INFLUENCE OVER THE LAKE THROUGH THE END OF THE WEEK. LOWS WILL PASS TO THE EAST AND SOUTH OF THE LAKE SO PERIODS OF SLIGHTLY STRONGER WINDS WILL BE POSSIBLE DESPITE THE PRESENCE OF THE HIGH...BUT HIGHEST SPEEDS LOOK TO BE UNDER 20 KTS OR SO FROM MID WEEK ONWARD. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1234 AM CDT SUN APR 1 2012 .DISCUSSION... 908 PM CDT SOME MINOR CHANGES TO POPS AND WX FOR TONIGHT. MAINLY DELAYING ARRIVAL OF THREAT OF SHRA AND TSRA UNTIL LATER TONIGHT AND REDUCING POPS OVER FAR NE IL FOR OVERNIGHT. RADAR COMPOSITE SHOWS WEAK ECHOES TO THE W THRU N OF THE LOCAL AREA WHERE INITIAL WAA AND RESULTING UVV AT MAINLY MID LEVELS OCCURRING. EXPECT THESE ECHOES...ALREADY MOSTLY VIRGA UPSTREAM WITH FEW IF ANY METARS REPORTING ANY PRECIP...WILL CONTINUE TO DRY UP AS THEY MOVE INTO INCREASINGLY DRY MID AND LOW LEVELS. A THUNDERSTORM DEVELOPED JUST NE OF DSM AROUND 0030Z AND ARE SLOWLY INCREASING IN NUMBER AS THEY MOVE ENE-E. THESE TSRA ARE WHERE BETTER MOISTURE IN THE 850 TO 800 HPA LAYER IS IN PLACE...WHERE WEAK SURFACE CONVERGENCE IS OCCURRING...WHERE NOSE OF 45 KT SOUTHWESTERLY JET AT 5 TO 6 K FT AGL SHOWN BY KDMX VAD WIND PROFILE IS LOCATED...AND JUST AHEAD OF WEAK MID LEVEL SHORT WAVE TROF MOVING OVER CENTRAL IA. CHALLENGE TO FORECAST IS HOW EXTENSIVE FURTHER TSRA DEVELOPMENT WILL BE AND WHERE AREA OF STORMS IS LIKELY TO MOVE OVERNIGHT. LATEST RUC13 RUN INDICATES A RATHER SMALL AREA OF MID LEVEL ISENTROPIC LIFT CURRENTLY OVER CENTRAL IA MOVES THIS AREA EASTWARD TO E CENTRAL IA 04-06Z...AND THEN SOUTHEASTWARD ACROSS N CENTRAL IL TO THE CENTRAL IL-IND BORDER BY 12Z. THIS APPEARS TO BE BEST TRACK FOR THE ELEVATED TSRA THAT IS EXPECTED TO BE MAINTAINED THROUGH THE OVERNIGHT BY THE LLJ...THE MID LEVEL SHORT WAVE AND STEEPENING MID LEVEL LAPSE RATES. EXPECT RATHER SMALL AREA OF TSRA AS MOISTURE WILL BE MARGINAL SO ONLY ANTICIPATE ACTIVITY WHERE FORCING FACTORS ARE MAXIMIZED DURING THE OVERNIGHT. TRS //PREV DISCUSSION... 317 PM CDT MAIN FORECAST ISSUES/CONCERNS FOR THE REMAINDER OF THE WEEKEND ARE WITH CHANCES FOR SHOWERS/THUNDERSTORMS LATE TONIGHT INTO SUNDAY MORNING...AS WELL AS TEMPERATURE TRENDS SUNDAY. WITH THE LOW LEVEL CLOUD COVER TODAY MASKING THE FACT THAT HIGH PRESSURE IS OVERHEAD...RELATIVELY QUIET CONDITIONS HAVE BEEN IN PLACE FOR ALL OF TODAY. ALTHOUGH...OVER THE LAST COUPLE OF HOURS SEVERAL HOLES DEVELOPED WITHIN THIS LOW LEVEL MOISTURE. A WARM SUN AND DRIER AIR ALOFT HAS ALLOWED FOR THESE HOLES TO CONTINUE TO EXPAND WITH SOME AREAS ACROSS THE SOUTHERN CWA OBSERVING SUNNY TO PARTLY CLOUDY SKIES. WITHIN THESE AREAS OF BETTER SOLAR INSOLATION...TEMPS HAVE QUICKLY RISEN INTO THE 50S WITH SOME AREAS OBSERVING SOME PLEASANT CONDITIONS AS RATHER LIGHT FLOW REMAINS IN PLACE. EXPECT THIS LOW CLOUD SHIELD TO CONTINUE TO ERODE WITH TIME LATE THIS AFTERNOON AND EARLY EVENING BUT WITH SOME MID AND HIGH LEVEL CLOUD COVER TO PUSH OVERHEAD. THIS IN ITSELF SHOULD PROVIDE PARTLY CLOUDY SKIES FOR TONIGHT...BUT WITH PRECIP CHANCES LATER TONIGHT TO POSSIBLY BRING MORE CLOUDY CONDITIONS MORE TOWARDS EARLY SUNDAY MORNING. LATEST GUIDANCE CONTINUES TO INDICATE SHOWERS AND THUNDERSTORMS DEVELOPING TONIGHT ACROSS EASTERN IOWA AND SHIFTING EAST/SOUTHEAST ACROSS A PORTION OF THE CWA THROUGH SUNDAY MORNING. ALL GUIDANCE IS INDICATING THIS POSSIBILITY BUT WITH SOME VARIABILITY STILL REMAINING WITH REGARDS TO EXACT TIMING AND PLACEMENT/TRACK. WITH BACKING 850MB FLOW...A WARMER AND MORE MOIST AIR MASS LOCATED ACROSS THE CENTRAL PLAINS WILL ADVECT NORTH/NORTHEAST WITH TIME TONIGHT BRINGING HIGHER DEW POINT AIR TO THE REGION. NORTHWEST FLOW ALOFT WILL STEER A MID LEVEL IMPULSE AND ATTENDANT SURFACE TROUGH OUT OF THE NORTHERN PLAINS THIS EVENING...AND HELP TO INITIATE CONVECTION ALONG A LOW LEVEL BAROCLINIC ZONE DRAPED ACROSS THE REGION. WITH LOW LEVEL FLOW FEEDING HIGHER THETA E AIR OVER THIS BOUNDARY AND INTO ANY DEVELOPING PRECIP...THIS AREA OF CONVECTION COULD SEE SOME EXPANSION IN COVERAGE AS IT SHIFTS EAST/SOUTHEAST THROUGH THE CWA EARLY SUNDAY MORNING. ALTHOUGH...GUIDANCE CONTINUES TO STRUGGLE WITH EXACT TIMING OF WHEN CONVECTION WILL DEVELOP AND WHERE THIS DEVELOPING AREA OF PRECIPITATION WILL PROGRESS THROUGH. DUE TO THIS UNCERTAINTY STILL IN PLACE...HAVE NOT MADE MANY CHANGES TO THE GOING POP GRIDS FOR TONIGHT KEEPING HIGH CHANCE POPS FOR MUCH OF THE CWA AFTER THE MIDNIGHT TIME FRAME THROUGH MID MORNING SUNDAY. THIS IS BASED ON THE LIKELIHOOD THAT CONVECTION SHOULD BEGIN TO DEVELOP OVER IOWA ONCE WE DECOUPLE AND THE LLJ RAMPS UP...WHICH SHOULD BE AROUND THE 3Z-6Z TIME FRAME. SOME HI RES DATA IS SHOWING THE POSSIBILITY OF AN MCS DEVELOPING AND QUICKLY SHIFTING THROUGH THE REGION SUNDAY MORNING. HAVE NOT COMPLETELY THROWN THIS OUT AS A POSSIBILITY...WITH DECENT LOW LEVEL SHEAR TO BE PRESENT ACROSS THE REGION. A LIMITING FACTOR WILL BE THE AMOUNT OF INSTABILITY PRESENT OVER NORTHERN ILLINOIS AND NORTHWEST...WHICH AM CURRENTLY LEANING MORE ON THE SREF MUCAPE OUTPUT WHICH IS SHOWING WEAKER INSTABILITY PRESENT BY EARLY SUNDAY MORNING LIMITING MORE ROBUST CONVECTION...WITH OTHER GUIDANCE OF COURSE ALSO VARYING TO THIS AMOUNT. SO WITH ANY PRECIP WHICH MOVES THROUGH THE AREA LATE TONIGHT AND EARLY SUNDAY MORNING...A MORE LIKELY SCENARIO WILL BE FOR THIS TO BE AN UNORGANIZED AREA OF SHOWERS AND ELEVATED THUNDERSTORMS WITH LITTLE CHANCES FOR SEVERE WEATHER...HAIL/WIND. ONLY AN ISOLATED THREAT OF HAIL COULD BE OBSERVED MAINLY FOR THE WESTERN CWA WHERE BETTER INSTABILITY AND STRONGER EFFECTIVE BULK SHEAR WILL RESIDE. EVEN IF A MORE ORGANIZED MCS COULD DEVELOP...WOULD EXPECT IT TO FOLLOW THE HIGHER SURFACE DEW POINT AIR AND BETTER INSTABILITY WHICH WOULD MORE THAN LIKELY BE SITUATED TO THE SOUTH OF THE CWA. THUS...ONCE AGAIN KEEPING ANY THREAT FOR SEVERE WEATHER JUST OUTSIDE OF THE CWA. THIS SITUATION WARRANTS CONTINUED MONITORING...AND WILL MAINTAIN A MENTION FOR THE CHANCES FOR THUNDERSTORMS TONIGHT IN THE HWO. ANY LINGERING SHOWERS/THUNDERSTORMS SHOULD EXIT THE CWA BY MID DAY WITH PARTLY CLOUDY TO SUNNY CONDITIONS EXPECTED THROUGH THE AFTERNOON. THE EXTENT OF THE MORNINGS PRECIP WILL DEFINITELY PLAY A KEY ROLE WITH MAX TEMPS ON SUNDAY WITH PERSISTENT WAA ADVECTING A WARMER AIR MASS OVERHEAD. AS SURFACE WARM FRONT TRIES TO LIFT NORTHEAST ACROSS THE CWA DURING THE DAY SUNDAY...IT WILL ACTUALLY BEGIN TO RETREAT AS A COLD FRONT WITH COOLER LOW LEVEL AIR WORKING ITS WAY BACK WEST ACROSS THE CWA LATE IN THE AFTERNOON AND EARLY EVENING. SO OUTSIDE OF PRECIP TRENDS POSSIBLY AFFECTING TEMP TRENDS SUNDAY...PLACEMENT OF THIS BOUNDARY AND MOVEMENT WILL BE KEY IN DEFINING MAX TEMPS FOR SUNDAY. DID BRING DOWN TEMPS A TAD FROM GOING FORECAST BUT HAVE KEPT THE WEST/SOUTHWEST CWA WARMER THAN THE EAST WITH AREAS STILL TO POSSIBLY REACH THE 80 MARK...AND AREAS ACROSS THE EASTERN CWA TO REACH THE LOWER 70S WITH 60S EXPECTED FOR AREAS NEAR THE LAKE. HAVE ADDED SLIGHT CHANCE POPS FOR THE SOUTHEAST PORTION OF THE CWA FOR SUNDAY AFTERNOON WHERE BETTER FOCUS AND UPPER LEVEL SUPPORT COULD PROVIDE FOR DEVELOPMENT OF THUNDERSTORMS. STRONG UPPER LEVEL RIDGING WILL OCCUR ON MONDAY WITH MID AND UPPER LEVEL FLOW BECOMING RATHER WEAK. THIS WEAK FLOW COINCIDING WITH A FORECASTED CLOSED UPPER LEVEL LOW TRACKING THROUGH THE SOUTHERN US WILL PROVIDE A TRICKY FORECAST THROUGH THE REMAINDER OF THE WEEK WITH THE ANTICIPATION FOR GUIDANCE TO CONTINUE TO STRUGGLE WITH PLACEMENT OF LOW LEVEL FEATURES AND INEVITABLE PRECIP. ALTHOUGH...THERE DOES APPEAR TO BE BETTER CHANCES FOR OBSERVING CONVECTION MONDAY NIGHT. BETTER FORCING AS WELL AS INSTABILITY LOOK TO BE IN PLACE FOR THE DEVELOPMENT OF POSSIBLY MORE ORGANIZED CONVECTION...WITH CURRENT GUIDANCE INDICATING BETTER CHANCES RESIDING ACROSS NORTHERN ILLINOIS INTO EARLY TUESDAY MORNING. HAVE NOT GONE OVERLY EXCITED WITH POPS DURING THIS TIME FRAME AS THE ECMWF REMAINS THE OUTLIER KEEPING A SURFACE LOW AND FORCING/PRECIP OFF TO THE WEST FOR MOST OF MONDAY AND MONDAY NIGHT. IF THIS WERE TO COME INTO FRUITION...THAN DRIER CONDITIONS WOULD BE OBSERVED MONDAY NIGHT WITH PRECIP DELAYED UNTIL TUESDAY. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * COVERAGE/TIMING OF THUNDERSTORMS EARLY THIS MORNING. * WIND SHIFT TO NORTHEAST BY LATE MORNING/MID-DAY. * POTENTIAL FOR PERIOD OF MVFR CEILINGS 1500-2000 FT LATE MORNING TO MID-AFTERNOON. RATZER //DISCUSSION...UPDATED 06Z... INITIAL CONCERN THIS MORNING IS WITH POTENTIAL FOR THUNDERSTORMS TO AFFECT TERMINALS DURING THE PRE-DAWN HOURS. AREA OF ELEVATED CONVECTION OVER FAR WESTERN IL AND NORTHEAST IA IS SLOWLY PROPAGATING TO THE EAST-SOUTHEAST AND WOULD LIKELY SKIRT SOUTH OF TERMINALS LATER THIS AM. NEW DEVELOPMENT CONTINUES TO OCCUR ON THE NORTHERN FRINGE OF THE CONVECTIVE COMPLEX ACROSS NORTHEAST IA HOWEVER...AND SEVERAL HIGH RES EXPLICIT CONVECTION MODELS CONTINUE TO DEPICT CONTINUED DEVELOPMENT INTO FAR NORTHERN IL TOWARD 09-10Z. THEREFORE HAVE MAINTAINED A BRIEF TEMPO MENTION FOR TS WITH SOME MINOR TIMING ADJUSTMENTS BASED ON RADAR EXTRAPOLATION PARTICULARLY FOR KRFD. ONCE MORNING STORMS MOVE OFF TO THE EAST...NEXT CONCERN IS WINDS SHIFTING TO THE NORTHEAST AND THE POTENTIAL FOR A PERIOD OF MVFR CEILINGS. GUIDANCE CONTINUES TO INDICATE WIND SHIFT BY VERY LATE MORNING/MID-DAY AS WEAK SURFACE WAVE MOVES EAST AND REINFORCING COLD FRONT SAGS SOUTH ACROSS TERMINALS. FORECAST SOUNDINGS DEPICT MOIST LAYER 1500-2000 FT IN COOL ADVECTION BENEATH INVERSION ALOFT. FORECAST SOUNDINGS INDICATE ENOUGH DRYING TAKES PLACE BY MID-LATE AFTERNOON TO SCATTER CLOUDS. WINDS...SOUTHEAST LESS THAN 10 KTS AT TAF ISSUANCE EXPECTED TO BECOME SOUTH OVERNIGHT...THEN LIGHT WESTERLY AFTER SUNRISE. AFOREMENTIONED FRONT THEN SAGS THROUGH WITH SHIFT TO THE NORTHEAST BY LATE MORNING OR SO...WITH GUSTS TO 15 KT POSSIBLE IN DEEPER MIXING WITH LOW LEVEL COLD ADVECTION. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE THUNDERSTORMS WILL AFFECT TRACON AIRSPACE...BUT MEDIUM CONFIDENCE IN DIRECT IMPACT ON INDIVIDUAL TERMINALS. * HIGH CONFIDENCE IN WIND TRENDS THROUGH PERIOD. * MEDIUM CONFIDENCE IN PERIOD OF 1500-2000 FT CIGS LATE MORNING INTO THIS AFTERNOON. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT. TUESDAY...VFR WITH CHANCE SHRA EARLY. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. RATZER && .MARINE... 115 PM CDT WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES. LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING. AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY. HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN THE NEXT WEEK. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
745 PM EDT MON APR 2 2012 .AVIATION... VFR CONDITIONS TO BEGIN THIS TAF PACKAGE WITH CLEAR SKIES AND SOUTHEAST WINDS IN THE 8 TO 12 KNOT RANGE. EXPECT THIS FOR MOST OF EARLY TO MID EVENING HOURS BEFORE DEVELOPING WARM FRONT TO THE WEST APPROACHES OVERNIGHT. LOW LEVEL JET EXPECTED TO INCREASE OVER THIS BOUNDARY WITH THETA E ADVECTION INCREASING. THIS SHOULD LEAD TO MID LEVEL CLOUD DECK AND POTENTIAL FOR TSRA DEVELOPMENT UPSTREAM OVER NORTHERN IL OR WI LATE. FLOW WOULD BRING ANY DEVELOPMENT SOUTHEAST INTO OUR AREA WITH KSBN BEING CLOSEST TO FORCING AND POSSIBLE TSRA. KEPT VCTS AND CB MENTION THERE TOWARD DAYBREAK WITH CB MENTION AT KFWA WITH MORE UNCERTAINTY. ONCE THIS ACTIVITY PASSES SHOULD SEE A DRY REMAINDER OF MORNING AND EARLY TO MID AFTERNOON WITH SHORT WAVE RIDGE OVER AREA AND WARM CAPPED ATMOSPHERE. SOME POSSIBLE DEVELOPMENT LATE AFTERNOON/EARLY EVENING AHEAD OF COLD FRONT BUT TOO MUCH UNCERTAINTY FOR TSRA INCLUSION IN THIS PACKAGE. && .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT CHANCES OF MORE THUNDERSTORMS LATE TONIGHT THROUGH TUESDAY EVENING AND WARMER TEMPERATURES FOR TUESDAY WILL BE THE MAIN SHORT TERM CONCERNS. FOR TONIGHT...MOSTLY CLEAR SKIES EXPECTED ACROSS MUCH OF THE AREA THIS EVENING WITH SOME INCREASING IN MID LEVEL CLOUDINESS WITH MID LEVEL FRONTAL ZONE EXTENDING FROM NORTHERN LOWER MICHIGAN INTO NORTHWEST OHIO. SOME LOWER BASED CLOUDS HAVE ALSO BEEN DEVELOPING ALONG A LINE FROM NORTHWEST ILLINOIS INTO WEST CENTRAL ILLINOIS WHICH SEEM TO CORRELATE WELL WITH RUC 900/850 HPA LAYER FRONTOGENESIS FIELDS THIS AFTERNOON. THIS AXIS WILL GRADUALLY SHIFT EASTWARD LATER THIS EVENING WITH INCREASE IN CLOUDINESS LATER THIS EVENING FROM WEST TO EAST. WATER VAPOR IMAGERY NOT DEPICTING ANY IMMEDIATE SHORT WAVES OF CONSEQUENCE FOR THE LOCAL AREA TONIGHT BUT CONSISTENT SIGNAL OVER THE PAST FEW DAYS HAS BEEN FOR DEVELOPMENT OF 30 KNOT SOUTHWESTERLY LOW LEVEL JET NOSING INTO FAR NORTH CENTRAL INDIANA/SOUTHERN LOWER MICHIGAN...PERHAPS A BIT MORE DELAYED IN THE LAST FEW MODEL CYCLES. SEE LITTLE TO DEVIATE FROM PREVIOUS FORECAST FOR TONIGHT AT THIS POINT WITH MID CHANCE POPS NORTH AND LOW CHANCE POPS SOUTH...WITH THE HIGHER TSRA POPS LINING UP BETTER WITH 850 HPA MOISTURE CONVERGENCE ACROSS SOUTHERN LOWER MICHIGAN AND FAR NORTHERN INDIANA AFTER 06Z AS STRONG LOW LEVEL THETAE ADVECTION SPREADS FROM WEST TO EAST. ELEVATED MIXED LAYER ADVECTING INTO THE AREA LATER TONIGHT DOES POSE SOME UNCERTAINTY WITH MAGNITUDE OF ELEVATED INSTABILITY. TAKING A 900 HPA BASED PARCEL FROM 12Z NAM BUFFER SOUNDINGS YIELDS BETWEEN 1000-1500 J/KG OF ELEVATED CAPE AFTER 06Z. 12Z GFS BUFFER SOUNDINGS REMAIN A BIT MORE PRONOUNCED WITH THIS ELEVATED MIXED LAYER AND MID LEVEL WARM LAYER THAT WOULD RESULT IN LESSER INSTABILITY THAN INDICATED BY THE NAM. EFFECTIVE SHEAR FOR THESE ELEVATED PARCELS SHOULD DECREASE STEADILY OVERNIGHT HOWEVER WHICH SHOULD TEND TO LIMIT POTENTIAL FOR CONVECTIVE ORGANIZATION/SEVERE THREAT. PREVIOUS FORECAST IDEA OF ISOLATED LARGE HAIL THREAT STILL SEEMS IN ORDER...BUT SHIFTED A BIT LATER AFTER 06Z BASED ON TREND OF SLIGHTLY SLOWER MODEL DEPICTION OF LOW LEVEL JET AXIS SHIFTING INTO THE AREA. LINGERING ELEVATED CONVECTION SHOULD DIMINISH EARLY TUESDAY AS LOW LEVEL JET VEERS AND MOISTURE CONVERGENCE WEAKENS. A CONVECTIVELY ENHANCED VORT MAX ACROSS EASTERN TEXAS THIS AFTERNOON SHOULD LIFT NORTHWARD INTO MID MS RVR VALLEY LATE TUESDAY AFTERNOON...BUT OVERALL CONVECTIVE THREAT APPEARS TO BE LOW FOR LATE MORNING/AFTERNOON HOURS WITH FCST SOUNDINGS SUGGEST SOME CAPPING CONCERNS. THUS...HAVE LOWERED AFTERNOON TSRA POPS AND MAINTAINED HIGHEST CHANCE ACROSS THE WEST WHERE FORCING FROM THIS VORT MAX WILL LIKELY BE MAXIMIZED. BEST CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE FOR THE EVENING HOURS AS ANOTHER SOUTHERN CANADIAN UPPER LEVEL SHORT WAVE PROVIDES IMPETUS FOR SFC LOW/FRONT TO SHIFT SOUTHEAST THROUGH THE AREA. LOW LEVEL FRONTOGENESIS ALSO TO STRENGTHEN AS STRONGER NORTHERLY FLOW INTERACTS WITH THIS BOUNDARY DURING THE EARLY EVENING. SEVERE POTENTIAL APPEARS TO BE RELATIVELY LOW AT THIS TIME DUE TO CONTINUED MARGINAL TO WEAK SHEAR PROFILES. HAVE ALSO INCREASED MAX TEMPS FOR TUESDAY WITH CONFIDENCE INCREASING THAT MOST IF NOT ALL OF FORECAST AREA WILL GET INTO WARM SECTOR AGAIN BEFORE FRONTAL PASSAGE IN THE FAR NORTHWEST MID TO LATE AFTERNOON. RECORD HIGHS IN THE UPPER 70S FOR FORT WAYNE AND SOUTH BEND COULD ONCE AGAIN BE AT RISK OF BEING BROKEN. && .LONG TERM... WEDNESDAY THROUGH MONDAY MAIN FOCUS OF LONG TERM PERIOD IS COOLER TEMPERATURES AND FROST POTENTIAL WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. LONG TERM PERIOD BEGINS WEDNESDAY WITH SURFACE HIGH PRESSURE CENTERED NORTHWEST OF THE REGION BUILDING SOUTHEASTWARD INTO THE LOWER GREAT LAKES...AND A FRONTAL BOUNDARY SITUATED ALONG THE OHIO RIVER VALLEY. CUTOFF UPPER LOW OVER PANHANDLE REGION WILL SLOWLY TRACK EASTWARD TOWARDS MID MISSISSIPPI VALLEY. DRY CONDITIONS ARE EXPECTED WEDNESDAY AND WEDNESDAY NIGHT. KEPT PATCHY FROST MENTION IN THE NE PORTION OF THE FA...BUT INCREASED GRADIENT OF LOW TEMPS FROM NE TO SW AS CUTOFF LOW AND AFOREMENTIONED BOUNDARY PASS JUST SOUTH OF THE FA. CUTOFF LOW WILL CONTINUE EASTWARD INTO LOWER OHIO VALLEY ON THURSDAY. 12Z GFS INDICATED PRECIP POTENTIAL ACROSS THE FAR SW PORTIONS OF THE FA AS FRONTAL BOUNDARY SLIDES EASTWARD. HOWEVER...CONFIDENCE IS LOW AS 12Z GFS RUN OPENS LOW INTO POSITIVELY TILTED WAVE QUICKER AND DIVES MORE SOUTHEASTERLY THAN PREVIOUS RUN...MORE IN LINE WITH 00Z ECMWF. THURSDAY NIGHT LOOKS TO BE THE COOLEST NIGHT IN THE EXTENDED PERIOD AS SFC RIDGE AXIS SLIDES OVERHEAD. KEPT THE AREAS OF FROST MENTION IN ROUGHLY THE SAME AREAS AS PREVIOUS FCST. WILL CONTINUE TO MONITOR THIS PD OVER THE NEXT FEW FORECASTS WITH POSSIBLE NEED FOR HEADLINES...WITH LOWS NEARING 32-33 ACROSS MUCH OF THE FA. SFC RIDGE WILL CONTINUE TO SLIDE EAST ACROSS GREAT LAKES AS UPPER RIDGE AXIS MOVES ACROSS THE REGION. FRIDAY WILL AGAIN BE COOLER WITH EASTERLY WINDS AND SLOWLY MODERATING AIRMASS. KEPT PATCHY FROST MENTION IN FCST FRI NIGHT AS RIDGE AXIS WILL BE JUST EAST OF FA AND LIGHTER WINDS. SATURDAY WILL BE CONSIDERABLY WARM WITH UPPER RIDGE OVER THE AREA AND SFC HIGH EAST...RESULTING IN SOUTHERLY WINDS AND WAA. RAISED TEMPS A FEW DEGREES FROM PREVIOUS FCST/ALLBLEND. NEXT PRECIP CHANCES RETURN SAT NIGHT/SUN AS DEEPENING SFC LOW/EJECTING WRN CONUS TROF ENERGY ACROSS NRN TIER BRINGS A COLD FRONT THROUGH THE REGION. KEPT POPS CHANCE/SLIGHT CHANCE AS BEST FORCING REMAINS NORTH AND BEST MOISTURE/INSTABILITY REMAINS SOUTH. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MARSILI LONG TERM...NG AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
401 AM EDT SUN APR 1 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY. BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS OUT FOR THE WEEKEND. && .NEAR TERM /OVERNIGHT/... LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE LOWER WABASH VALLEY. FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT. HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK. WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE... POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE TO HIGHLIGHT IN THE HWO. LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z BEFORE ANY STORMS ARRIVE. ZONE AND GRID UPDATES OUT. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE LARGE HAIL. LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE AREA. FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... EUROPEAN MODEL BECOMES MUCH COLDER THAN GFS AT 850 MILLIBARS LATE IN PERIOD. OVERALL EUROPEAN MORE CONSISTENT WITH CANADIAN AND BRITISH MODELS IN DEVELOPING A VORTEX OVER THE NORTHEAST STATES THAT WILL DRAW RELATIVELY CHILLY AIR INTO INDIANA. FORTUNATELY...ALL BLEND MODEL SEEMS TO CAPTURE THIS FAIRLY WELL WITH HIGHS LOWER 60S AND LOWS LOWER 40S LATE IN THE PERIOD. DID NOT SEE NEED TO CHANGE ALL BLEND INITIALIZATION. ALTHOUGH EUROPEAN AND GFS MUCH DIFFERENT IN STRENGTH...THEIR PHASE IS NOT THAT DIFFERENT. WHILE THIS RESULTS IN BIG DIFFERENCES FOR TEMPERATURES...TIMING OF PRECIPITATION APT TO BE CLOSER. ALL BLEND SEEMS TO CAPTURE THIS WITH QUITE LOW POPS FRIDAY AND SATURDAY IN PARTICULAR. NO NEED TO CHANGE INITIALIZATION MUCH. && .AVIATION /DISCUSSION FOR THE 010900Z TAF UPDATE/... EARLIER FORECAST ON TRACK OVERALL...BUT TUNING WILL BE NEEDED FOR PRECISE TIMING AS SHOWERS AND THUNDERSTORMS MOVE IN FROM THE WEST AND NORTH. CONFIDENCE IS LOW SINCE EXACT CONDITIONS AT ANY ONE TERMINAL COULD CHANGE GREATLY OVER SHORT PERIODS. MVFR CONDITIONS IN TSRA POSSIBLE THROUGH 15Z...THEN EXPECT A RETURN TO VFR FOR THE REMAINDER OF SUNDAY. AREA OF TSRA ACROSS NORTHWEST ILLINOIS WILL CONTINUE TO SHIFT SOUTHEAST TOWARD THE SITES. QUESTIONS ARISE IN HOW WELL THEY WILL HOLD TOGETHER AS UPPER SUPPORT WILL FIGHT WITH POOR INSTABILITY IN THE LOWER LEVELS. FOR NOW WILL JUST GO WITH VCSH AND CB MENTION...BUT WILL HAVE TO KEEP A CLOSE EYE ON TSRA EVOLUTION. TEMPO GROUPS MAY BE NEEDED FOR SHORT TIME IN TAFS. TSRA THREAT SHOULD DIMINISH BY 15Z. UNCERTAINTY REMAINS ON ANY LINGERING CLOUD COVER FROM TSRA...BUT EXPECT BKN CU TO DEVELOP IF THERE IS SUNSHINE. THUS JUST KEPT BKN060 DURING THE DAY SUNDAY. ADDITIONAL CONVECTION MAY DEVELOP SUNDAY AFTERNOON...BUT THAT IS TOO FAR OUT TO MENTION IN TAFS AT THE MOMENT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...RYAN SHORT TERM...CP LONG TERM....JK AVIATION...JK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
317 AM EDT SUN APR 1 2012 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY. BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS OUT FOR THE WEEKEND. && .NEAR TERM /OVERNIGHT/... LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE LOWER WABASH VALLEY. FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT. HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK. WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE... POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE TO HIGHLIGHT IN THE HWO. LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z BEFORE ANY STORMS ARRIVE. ZONE AND GRID UPDATES OUT. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE LARGE HAIL. LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE AREA. FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... EUROPEAN MODEL BECOMES MUCH COLDER THAN GFS AT 850 MILLIBARS LATE IN PERIOD. OVERALL EUROPEAN MORE CONSISTENT WITH CANADIAN AND BRITISH MODELS IN DEVELOPING A VORTEX OVER THE NORTHEAST STATES THAT WILL DRAW RELATIVELY CHILLY AIR INTO INDIANA. FORTUNATELY...ALL BLEND MODEL SEEMS TO CAPTURE THIS FAIRLY WELL WITH HIGHS LOWER 60S AND LOWS LOWER 40S LATE IN THE PERIOD. DID NOT SEE NEED TO CHANGE ALL BLEND INITIALIZATION. ALTHOUGH EUROPEAN AND GFS MUCH DIFFERENT IN STRENGTH...THEIR PHASE IS NOT THAT DIFFERENT. WHILE THIS RESULTS IN BIG DIFFERENCES FOR TEMPERATURES...TIMING OF PRECIPITATION APT TO BE CLOSER. ALL BLEND SEEMS TO CAPTURE THIS WITH QUITE LOW POPS FRIDAY AND SATURDAY IN PARTICULAR. NO NEED TO CHANGE INITIALIZATION MUCH. && .AVIATION /DISCUSSION FOR THE 010600Z TAFS/... MVFR CONDITIONS IN FOG OR TSRA POSSIBLE THROUGH 15Z...THEN EXPECT A RETURN TO VFR FOR THE REMAINDER OF THE DAY ON SUNDAY. AREA OF TSRA ACROSS NORTHWEST ILLINOIS WILL CONTINUE TO SHIFT SOUTHEAST TOWARD THE SITES. QUESTIONS ARISE IN HOW WELL THEY WILL HOLD TOGETHER AS UPPER SUPPORT WILL FIGHT WITH POOR INSTABILITY IN THE LOWER LEVELS. FOR NOW WILL JUST GO WITH VCSH AND CB MENTION...BUT WILL HAVE TO KEEP A CLOSE EYE ON TSRA EVOLUTION. AT THE MOMENT CONFIDENCE IS LOW. TSRA/FOG THREAT SHOULD DIMINISH BY 15Z. UNCERTAINTY REMAINS ON ANY LINGERING CLOUD COVER FROM TSRA...BUT EXPECT BKN CU TO DEVELOP IF THERE IS SUNSHINE. THUS JUST KEPT BKN060 DURING THE DAY SUNDAY. ADDITIONAL CONVECTION MAY DEVELOP SUNDAY AFTERNOON...BUT THAT IS TOO FAR OUT TO MENTION IN TAFS AT THE MOMENT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...RYAN SHORT TERM...CP LONG TERM....JK AVIATION...50/JK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1245 AM EDT SUN APR 1 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS...A WEAK FRONTAL SYSTEM MOVING THROUGH COULD BRING CHANCES FOR THUNDERSTORMS ACROSS THE AREA LATE TONIGHT INTO SUNDAY. BY SUNDAY NIGHT UPPER RIDGING SHOULD REBUILD AND DRY THE WEATHER OUT THROUGH MONDAY...BUT BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM WILL APPROACH AND STALL OUT AND BRING THUNDERSTORM CHANCES FOR MONDAY NIGHT THROUGH THURSDAY. MORE UPPER RIDGING WILL DRY THINGS OUT FOR THE WEEKEND. && .NEAR TERM /OVERNIGHT/... LARGE AREA OF LOW STRATUS HAS FINALLY SHIFTED EAST WITH ONLY FAR NORTHEASTERN COUNTIES STILL UNDERNEATH THE DECK. REMAINDER OF THE FORECAST AREA HAD BECOME PARTLY CLOUDY WITH MID AND HIGH LEVEL CLOUDS DRIFTING ACROSS THE REGION. QUITE A RANGE OF TEMPERATURES EXISTED ACROSS THE FORECAST AREA AS OF 00Z...FROM MID 40S OVER THE NORTHEAST WHERE SKIES HAD BEEN CLOUDY ALL DAY TO MID 60S IN THE LOWER WABASH VALLEY. FOCUS FOR THE OVERNIGHT IS POTENTIAL FOR CONVECTION TO IMPACT WESTERN COUNTIES PRIOR TO DAYBREAK. SHORT RANGE MODEL GUIDANCE CONTINUING TO ADVERTISE DEVELOPMENT OF SCATTERED CONVECTION OVER EASTERN IOWA/WESTERN ILLINOIS SHORTLY AFTER MIDNIGHT AS AN UPPER LEVEL DISTURBANCE MOVES INTO THE REGION. PRESENCE OF A 35KT LOW LEVEL JET AND AXIS OF ELEVATED INSTABILITY SHOULD FURTHER CONTRIBUTE TO CONVECTIVE DEVELOPMENT IN THESE AREAS. STEERING FLOW ALOFT WOULD SUGGEST THAT CONVECTION WILL MOVE SOUTHEAST AND POTENTIALLY MIGRATE INTO THE NORTHERN WABASH VALLEY LATE TONIGHT. HAVE CHOSEN TO EXPAND LOW CHANCE POPS TO ENCOMPASS PORTIONS OF THE FORECAST AREA WEST OF A KOKOMO TO INDY METRO TO TERRE HAUTE LINE BETWEEN 09-12Z. HRRR GUIDANCE SUGGESTIVE OF LEADING EDGE OF CONVECTION ARRIVING INTO THESE AREAS SHORTLY BEFORE DAYBREAK. WHILE STORMS SHOULD BE WEAKENING BY THE TIME THEY ARRIVE IN CENTRAL INDIANA AS THE ENVIRONMENT WILL BE LESS FAVORABLE... POTENTIAL FOR STRONGER CELLS TO PRODUCE SMALL HAIL. WILL CONTINUE TO HIGHLIGHT IN THE HWO. LOWERED TEMPS A DEGREE OR TWO OVERNIGHT BASED ON CURRENT OBS...AND ADJUSTED TIMING AS LOWS LIKELY TO BOTTOM OUT BETWEEN 06 AND 08Z BEFORE ANY STORMS ARRIVE. ZONE AND GRID UPDATES OUT. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... MODELS ARE IN DECENT AGREEMENT ON THE SHORT TERM SO WILL USE A CONSENSUS GENERALLY...BUT THOUGHT EARLY ON THE NAM WAS A LITTLE OVERZEALOUS IN POPS AND PRECIP ARRIVAL WITH THE SUNDAY SYSTEM SO THERE WILL LEAN TOWARD THE GFS/ECMWF/SREFS. COULD HAVE AN MCS ARRIVING IN THE NORTHWEST TO START OUT SUNDAY. VERY WEAK UPPER FORCING WITH A LITTLE SHORTWAVE MOVING THROUGH BUT ISENTROPIC LIFT SHOULD BE GOING THROUGH THE DAY ON SUNDAY. INSTABILITY WILL INCREASE THROUGH THE DAY SO THAT MIXED LAYER CAPES OF 1000 TO 1500 OR SO WILL BE IN PLACE ACROSS THE EAST BY THE AFTERNOON. MARGINAL SHEAR /BOTH DIRECTIONAL AND SPEED/ WILL BE AVAILABLE AS WELL DURING THE AFTERNOON...AND THUS THE INCLUSION OF A SLIGHT RISK FOR SEVERE WEATHER ACROSS MUCH OF THE EASTERN COUNTIES FOR THAT TIME. ALSO HAVE MID LEVEL LAPSE RATES AROUND 7-8C SO EXPECT THE MAIN THREAT TO BE LARGE HAIL. LEFT A SLIGHT CHANCE IN THE FAR EAST THROUGH 3Z AS SYSTEM IS MOVING OUT OF THE AREA. UPPER RIDGING BUILDS BACK IN AND KEPT POPS OUT THROUGH MONDAY. BY MONDAY NIGHT ANOTHER FRONTAL SYSTEM MOVES IN TO NORTHERN ILLINOIS AND POSSIBLY NORTHERN INDIANA. THIS SURFACE LOW AND ISENTROPIC LIFT WILL SERVE AS THE MAIN FORCING MECHANISMS WITHOUT MUCH IN THE WAY OF UPPER FORCING AVAILABLE. WILL HAVE A CHANCE FOR THUNDERSTORMS MONDAY NIGHT AND INTO TUESDAY WITH THIS...WITH HIGHER CHANCES ON TUESDAY WITH THE LOW PASSING OVER THE AREA. FOR HIGH TEMPERATURES GENERALLY STUCK TOWARD THE WARMER END OF THE GUIDANCE ENVELOPE BASED ON RECENT VERIFICATION...AND COULD SEE A DECENT GRADIENT ACROSS THE AREA ON TUESDAY. FOR LOWS WENT A BIT WARMER THAN A CONSENSUS BASED ON EXPECTED CLOUD COVER AND FOR MONDAY NIGHT STUCK NEAR THE WET BULB TEMPERATURES WITH POTENTIAL FOR RAIN. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ENSEMBLES IN GENERAL AGREEMENT IN BRINGING A SYSTEM THAT IS PROGGED TO BE MOVING INTO THE WEST COAST SUNDAY ACROSS THE LOCAL AREA AROUND THE MIDDLE OF NEXT WEEK. ENSEMBLE TREND HAS BEEN TOWARDS CUTTING THIS SYSTEM OFF FROM THE MAIN WESTERLIES...AND TODAY THE MAJORITY OF THE ENSEMBLES POINT IN THIS DIRECTION...WITH THE EFFECTS OF THE CUTOFF AFFECTING THE AREA INTO THURSDAY. WILL GO WITH CHANCE POPS ON WEDNESDAY AND THURSDAY OVER MAINLY THE SOUTHERN ZONES...WHICH WILL BE CLOSER TO CUTOFF LOW. WILL CONTINUE WITH A DRY FORECAST FRIDAY AND SATURDAY AT THIS TIME WITH UPPER RIDGING MOVING THROUGH... ALTHOUGH SOME ENSEMBLES BRING A PRECIPITATION THREAT BACK INTO THE AREA BY NEXT SATURDAY. MAY NEED TO ADD POPS TO NEXT WEEKEND AT A LATER TIME IF FUTURE TRENDS POINT IN THAT DIRECTION. && .AVIATION /DISCUSSION FOR THE 010600Z TAFS/... MVFR CONDITIONS IN FOG OR TSRA POSSIBLE THROUGH 15Z...THEN EXPECT A RETURN TO VFR FOR THE REMAINDER OF THE DAY ON SUNDAY. AREA OF TSRA ACROSS NORTHWEST ILLINOIS WILL CONTINUE TO SHIFT SOUTHEAST TOWARD THE SITES. QUESTIONS ARISE IN HOW WELL THEY WILL HOLD TOGETHER AS UPPER SUPPORT WILL FIGHT WITH POOR INSTABILITY IN THE LOWER LEVELS. FOR NOW WILL JUST GO WITH VCSH AND CB MENTION...BUT WILL HAVE TO KEEP A CLOSE EYE ON TSRA EVOLUTION. AT THE MOMENT CONFIDENCE IS LOW. TSRA/FOG THREAT SHOULD DIMINISH BY 15Z. UNCERTAINTY REMAINS ON ANY LINGERING CLOUD COVER FROM TSRA...BUT EXPECT BKN CU TO DEVELOP IF THERE IS SUNSHINE. THUS JUST KEPT BKN060 DURING THE DAY SUNDAY. ADDITIONAL CONVECTION MAY DEVELOP SUNDAY AFTERNOON...BUT THAT IS TOO FAR OUT TO MENTION IN TAFS AT THE MOMENT. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...RYAN SHORT TERM...CP LONG TERM....JAS AVIATION...50/JK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
945 PM MDT MON APR 2 2012 .UPDATE... ISSUED AT 928 PM MDT MON APR 2 2012 AT 0330Z RAIN CONTINUES TO MOVE NORTHWEST AROUND 25 MPH IN RESPONSE TO LOW PRESSURE SPINNING ACROSS EAST CENTRAL NEW MEXICO. NORTH TO NORTHEAST WINDS CONTINUE TO GUST AROUND 40 MPH. FOR TONIGHT ALLOWED WIND ADVISORY TO EXPIRE. WIND GUSTS IN EXCESS OF 45 MPH ARE NO LONGER EXPECTED. FORECAST CHALLENGE FOR THE NEXT 20 HOUR OR SO IS PLACEMENT OF THE HIGHEST POPS/QPF AND SNOW. GENERALLY THINKING IS FOR CURRENT BAND OF PRECIPITATION TO MOVE NORTHWEST THROUGH THE FORECAST AREA DURING THE REMAINDER OF THE NIGHT WITH SOME DRIER MID LEVEL AIR CURRENTLY OVER THE TEXAS PANHANDLE TO QUICKLY MOVE NORTH BRINGING AN END TO THE HEAVIER PRECIPITATION (EXCEPT THE NORTHWEST 1/4 OF THE AREA) BY SUNRISE. FLAGLER CURRENT TEMP IS 37...NAM AND TO A LESSER EXTENT RUC LOWER TEMPERATURES INTO THE LOWER 30S BY SUNRISE WHICH WOULD SUPPORT SNOW VS ANY MIX OF RAIN AND SNOW. HOW FAR EAST THESE COLDER TEMPERATURES GET IS THE BIG QUESTION AS THE NAM PUSHES THEM AS FAR EAST AS THE CO/KS BORDER WHILE THE HRRR IS SLIGHTLY FURTHER WEST AND THE SREF FURTHER WEST TOWARD SEIBERT. RIGHT NOW ONLY HAVE SNOW ACCUMULATIONS OF A FEW INCHES CONFINED TO THE FLAGLER AREA AND MIDNIGHT SHIFT WILL NEED TO MONITOR JUST HOW FAR EAST THE COLDER TEMPERATURES GET. GIVEN THE EXPECTED PRECIPITATION SEVERAL INCHES OF ACCUMULATION IS CERTAINLY POSSIBLE. HAVE UPDATED HWO TO MENTION THE ACCUMULATION POSSIBILITIES. FOR TUESDAY LOWERED TEMPERATURES ACROSS THE ENTIRE AREA AS WE WILL BE UNDER EXTENSIVE CLOUD COVER. 00Z NAM/21Z SREF/00Z MET AND 18Z MAV 3 HOUR TEMPERATURES ALL IN PRETTY GOOD AGREEMENT WITH HIGHS RANGING FROM THE MID 30S TO LOW 40S ACROSS FAR EASTERN COLORADO TO THE MID 40S AND LOW 50S EAST OF THE BORDER. SHOULD HAVE ANOTHER BATCH OF RAIN MOVING IN FROM THE SOUTH DURING THE DAY WITH HIGHEST AMOUNTS GENERALLY SOUTH OF A LINE FROM YUMA TO COLBY AND GOVE. UPDATE ISSUED AT 541 PM MDT MON APR 2 2012 LINE OF SHOWERS AND THUNDERSTORMS JUST EAST-SOUTHEAST OF THE FORECAST AREA MOVING NORTHWEST AT 20-25 MPH. THIS WILL PUT THEM INTO THE SOUTHEAST PORTION OF THE AREA BY 01Z IF NOT A LITTLE SOONER. ALTHOUGH INSTABILITY REMAINS HIGHER TO THE SOUTHEAST OF OUR AREA CANT RULE OUT A FEW LIGHTNING STRIKES SO UPDATED TO INCLUDE SOME THUNDER MENTION. OTHER CHANGES WERE TO BEEF UP THE CLOUDINESS TONIGHT THROUGH TUESDAY AS LOW LEVEL MOISTURE AND CLOUDS COVER THE FORECAST AREA. OTHER CHANGES TO BE MADE LATER AS 00Z MODEL DATA COMES IN. && .SHORT TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 221 PM MDT MON APR 2 2012 PLAN TO LET THE WIND ADVISORY GO TO EXPIRATION AT 03Z. THIS SHOULD WORK OUT WELL SINCE HAVE ALREADY STARTED TO DECREASE. THE NAM MIXED LAYER WINDS INDICATE THAT THEY FALL AT OR JUST BELOW WIND ADVISORY LEVELS AT 03Z. THE GFS MIXED LAYER WIND KEEPS IT WINDY OVER THE SOUTHWEST THROUGH THE NIGHT. THIS IS PROBABLY AN OUTLIER SINCE THE TREND FOR WINDS IN THAT PART OF THE AREA IS SIMILAR TO THE REST OF THE FA. THE EVENING SHIFT WILL NEED TO DETERMINE WHETHER THE ADVISORY SHOULD BE EXTENDED IN TIME. THE UPPER LOW WILL MOVE NORTHEAST TONIGHT. THERE IS SOME UNCERTAINTY AS TO HOW QUICKLY PRECIPITATION WILL MOVE NORTHWARD SINCE THE MODELS DO NOT HAVE THE LOW AS FAR SOUTH AS ITS ACTUAL POSITION ON WATER VAPOR IMAGERY. NEVERTHELESS HAVE INTRODUCED CHANCE POPS FOR THE SOUTHERN ZONES THIS EVENING. BETTER CHANCES SHOULD TAKE PLACE AFTER MIDNIGHT TONIGHT AS THE LOW HAS MORE TIME TO MOVE NORTH. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL GET COLD ENOUGH FOR A FEW HOURS AROUND SUNRISE IN EASTERN COLORADO FOR A MIX OF RAIN/SNOW. THE NAM SHOWS A LULL IN THE PRECIPITATION TUESDAY MORNING WITH THE PASSAGE OF THE INITIAL SHORTWAVE SO WILL KEEP CHANCE POPS IN PLACE FOR TUESDAY MORNING. BY AFTERNOON THE NEXT WAVE IS PROGGED TO MOVE THROUGH THE FA SO WILL INCREASE TO HIGH CHANCE. LOW TEMPERATURES TONIGHT WILL GET DOWN TO 32 IN FAR WESTERN PORTIONS OF THE FA. OTHERWISE TEMPERATURES WILL RANGE FROM THE MID 30S FROM NEAR THE COLORADO BORDER TO THE LOWER 40S IN MCK AND HLC. MAX TEMPERATURES WILL RANGE FROM THE UPPER 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 221 PM MDT MON APR 2 2012 MAIN FOCUS WILL CONTINUE TO BE THE CLOSED LOW AND PRECIP. CHANCES THROUGH WEDNESDAY. MODELS ARE IN BETTER AGREEMENT WITH THE TRACK OF THE CLOSED LOW AS IT MOVES NORTHEAST. NOTICED THE 0Z ECMWF AND LATEST NAM/SREF ARE IN BETTER AGREEMENT THAN YESTERDAY. AS MENTIONED ABOVE...AM CONCERNED THE MODELS DID NOT INITIALIZE THE CLOSED LOW FAR ENOUGH SOUTH BASED MORNING WATER VAPOR IMAGERY. WITH THE CLOSED LOW BEING FURTHER SOUTH THAN WHAT THE MODELS HAVE...AM THINKING IT WILL LIFT FURTHER EAST THAN WHAT THE NAM/SREF/ECMWF HAVE. AS SUCH WILL TRENDED HIGHER POPS FURTHER EAST FOR TUESDAY NIGHT THROUGH WEDNESDAY BASED ON ABOVE CONCERNS. TUESDAY NIGHT THE LEFT EXIT OF THE UPPER LEVEL JET MOVES OVER THE EASTERN PART OF THE AREA AND ISENTROPIC LIFT INCREASES AS THE CLOSED LOW APPROACHES. OVER THE NORTHERN HALF OF THE AREA DEEP LIFTING SETS UP AND A BAND OF FRONTOGENESIS DEVELOPS. AS THE CLOSED LOW MOVES EAST THROUGH THE NIGHT THE LIFT FOLLOWS. TRENDED POPS IN THE SAME DIRECTION...WITH THE BEST CHANCES GENERALLY OVER THE EASTERN PART OF THE AREA WHERE THE BEST LIFT AND HIGHEST CERTAINTY WILL BE WITH LOWER CHANCES TO THE WEST WHERE THE I AM MORE UNCERTAIN THAT THE LIFT WILL DEVELOP BE AS THE SYSTEM MOVES EAST. AREAS OF EASTERN COLORADO MAY SEE A MIX OF RAIN AND SNOW AS TEMPERATURES DIP TO THE FREEZING POINT. NAM POINT SOUNDINGS SUGGEST A WINDOW OF FREEZING DRIZZLE DURING THE OVERNIGHT AND EARLY MORNING HOURS. HOWEVER SREF PRECIP. TYPE FIELDS ONLY SHOW A MIX OF RAIN AND SNOW. WILL JUST MENTION THE RAIN/SNOW MIX THROUGH THE NIGHT AND EARLY MORNING HOURS DUE TO UNCERTAINTY OF THE TRACK OF THE STORM SYSTEM. WEDNESDAY ISENTROPIC LIFT DWINDLES TOWARD THE WEST AS THE CLOSED LOW DEPARTS. HAVE PRECIP. CHANCES HIGHEST IN THE EAST WHERE THE FORCING FOR LIFT IS BEST WITH CHANCES DECLINING TO THE WEST. THROUGH THE DAY PRECIP. CHANCES DECLINE ACROSS THE AREA AS THE CLOSED LOW MOVES FURTHER EAST...WITH THE PRECIP. CHANCES COMING TO AN END OVER THE FAR EAST BY EARLY EVENING. FOR THURSDAY THROUGH MONDAY AN UPPER LEVEL SHORT WAVE RIDGE MOVES OVER THE AREA THURSDAY BEHIND THE EXITING STORM SYSTEM. BY THURSDAY NIGHT THE UPPER LEVEL FLOW TURNS TO THE NORTHWEST AHEAD OF THE NEXT UPPER LEVEL TROUGH MOVING ACROSS THE INTER MOUNTAIN WEST. PRECIPITATION CHANCES RETURN TO THE EASTERN PART OF THE AREA THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A COUPLE UPPER LEVEL SHORT WAVE TROUGHS MOVE OVER THE AREA. WITH THE LOW LEVEL JET AND ISENTROPIC LIFT AHEAD OF THE TROUGHS...A FEW SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE OVER THE EASTERN PART OF THE AREA. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD...WITH A WARMING TREND THURSDAY AND FRIDAY. COOLER BUT ABOVE NORMAL TEMPERATURES RETURN THROUGH THE REST OF THE PERIOD BEHIND A COLD FRONT THAT MOVES THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 553 PM MDT MON APR 2 2012 LOW CLOUDS TO THE NORTH AND AN AREA OF THUNDERSTORMS TO THE SOUTH WILL CONVERGE OVER THE AREA IN THE NEXT FEW HOURS. RUC IS HANDLING THE CLOUDS FAIRLY WELL SO HAVE USED THIS MODEL AS WELL AS THE HRRR CONCERNING THE PRECIPITATION. LOOK FOR MVFR CIGS AT BOTH TERMINALS IN THE 02-04Z RANGE WITH PRECIPITATION OCCURRING AROUND 03Z AT KGLD AND 08Z AT KMCK. THERE WILL BE A FEW HOURS OF POSSIBLE IFR AT KGLD AFTER THE PRECIPITATION HAS ENDED...THEN ANOTHER ROUND OF PRECIPITATION IN THE LATE MORNING INTO THE EARLY AFTERNOON. PRECIPITATION WILL END AROUND 12Z AT KMCK THEN HOLD OFF AGAIN UNTIL AFTER THIS TAF PERIOD. MVFR CIGS WILL HOLD THROUGH THE REST OF THE PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...007 SHORT TERM...FS LONG TERM....JTL AVIATION...BAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
553 PM MDT MON APR 2 2012 .UPDATE... ISSUED AT 541 PM MDT MON APR 2 2012 LINE OF SHOWERS AND THUNDERSTORMS JUST EAST-SOUTHEAST OF THE FORECAST AREA MOVING NORTHWEST AT 20-25 MPH. THIS WILL PUT THEM INTO THE SOUTHEAST PORTION OF THE AREA BY 01Z IF NOT A LITTLE SOONER. ALTHOUGH INSTABILITY REMAINS HIGHER TO THE SOUTHEAST OF OUR AREA CANT RULE OUT A FEW LIGHTNING STRIKES SO UPDATED TO INCLUDE SOME THUNDER MENTION. OTHER CHANGES WERE TO BEEF UP THE CLOUDINESS TONIGHT THROUGH TUESDAY AS LOW LEVEL MOISTURE AND CLOUDS COVER THE FORECAST AREA. OTHER CHANGES TO BE MADE LATER AS 00Z MODEL DATA COMES IN. && .SHORT TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 221 PM MDT MON APR 2 2012 PLAN TO LET THE WIND ADVISORY GO TO EXPIRATION AT 03Z. THIS SHOULD WORK OUT WELL SINCE HAVE ALREADY STARTED TO DECREASE. THE NAM MIXED LAYER WINDS INDICATE THAT THEY FALL AT OR JUST BELOW WIND ADVISORY LEVELS AT 03Z. THE GFS MIXED LAYER WIND KEEPS IT WINDY OVER THE SOUTHWEST THROUGH THE NIGHT. THIS IS PROBABLY AN OUTLIER SINCE THE TREND FOR WINDS IN THAT PART OF THE AREA IS SIMILAR TO THE REST OF THE FA. THE EVENING SHIFT WILL NEED TO DETERMINE WHETHER THE ADVISORY SHOULD BE EXTENDED IN TIME. THE UPPER LOW WILL MOVE NORTHEAST TONIGHT. THERE IS SOME UNCERTAINTY AS TO HOW QUICKLY PRECIPITATION WILL MOVE NORTHWARD SINCE THE MODELS DO NOT HAVE THE LOW AS FAR SOUTH AS ITS ACTUAL POSITION ON WATER VAPOR IMAGERY. NEVERTHELESS HAVE INTRODUCED CHANCE POPS FOR THE SOUTHERN ZONES THIS EVENING. BETTER CHANCES SHOULD TAKE PLACE AFTER MIDNIGHT TONIGHT AS THE LOW HAS MORE TIME TO MOVE NORTH. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL GET COLD ENOUGH FOR A FEW HOURS AROUND SUNRISE IN EASTERN COLORADO FOR A MIX OF RAIN/SNOW. THE NAM SHOWS A LULL IN THE PRECIPITATION TUESDAY MORNING WITH THE PASSAGE OF THE INITIAL SHORTWAVE SO WILL KEEP CHANCE POPS IN PLACE FOR TUESDAY MORNING. BY AFTERNOON THE NEXT WAVE IS PROGGED TO MOVE THROUGH THE FA SO WILL INCREASE TO HIGH CHANCE. LOW TEMPERATURES TONIGHT WILL GET DOWN TO 32 IN FAR WESTERN PORTIONS OF THE FA. OTHERWISE TEMPERATURES WILL RANGE FROM THE MID 30S FROM NEAR THE COLORADO BORDER TO THE LOWER 40S IN MCK AND HLC. MAX TEMPERATURES WILL RANGE FROM THE UPPER 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 221 PM MDT MON APR 2 2012 MAIN FOCUS WILL CONTINUE TO BE THE CLOSED LOW AND PRECIP. CHANCES THROUGH WEDNESDAY. MODELS ARE IN BETTER AGREEMENT WITH THE TRACK OF THE CLOSED LOW AS IT MOVES NORTHEAST. NOTICED THE 0Z ECMWF AND LATEST NAM/SREF ARE IN BETTER AGREEMENT THAN YESTERDAY. AS MENTIONED ABOVE...AM CONCERNED THE MODELS DID NOT INITIALIZE THE CLOSED LOW FAR ENOUGH SOUTH BASED MORNING WATER VAPOR IMAGERY. WITH THE CLOSED LOW BEING FURTHER SOUTH THAN WHAT THE MODELS HAVE...AM THINKING IT WILL LIFT FURTHER EAST THAN WHAT THE NAM/SREF/ECMWF HAVE. AS SUCH WILL TRENDED HIGHER POPS FURTHER EAST FOR TUESDAY NIGHT THROUGH WEDNESDAY BASED ON ABOVE CONCERNS. TUESDAY NIGHT THE LEFT EXIT OF THE UPPER LEVEL JET MOVES OVER THE EASTERN PART OF THE AREA AND ISENTROPIC LIFT INCREASES AS THE CLOSED LOW APPROACHES. OVER THE NORTHERN HALF OF THE AREA DEEP LIFTING SETS UP AND A BAND OF FRONTOGENESIS DEVELOPS. AS THE CLOSED LOW MOVES EAST THROUGH THE NIGHT THE LIFT FOLLOWS. TRENDED POPS IN THE SAME DIRECTION...WITH THE BEST CHANCES GENERALLY OVER THE EASTERN PART OF THE AREA WHERE THE BEST LIFT AND HIGHEST CERTAINTY WILL BE WITH LOWER CHANCES TO THE WEST WHERE THE I AM MORE UNCERTAIN THAT THE LIFT WILL DEVELOP BE AS THE SYSTEM MOVES EAST. AREAS OF EASTERN COLORADO MAY SEE A MIX OF RAIN AND SNOW AS TEMPERATURES DIP TO THE FREEZING POINT. NAM POINT SOUNDINGS SUGGEST A WINDOW OF FREEZING DRIZZLE DURING THE OVERNIGHT AND EARLY MORNING HOURS. HOWEVER SREF PRECIP. TYPE FIELDS ONLY SHOW A MIX OF RAIN AND SNOW. WILL JUST MENTION THE RAIN/SNOW MIX THROUGH THE NIGHT AND EARLY MORNING HOURS DUE TO UNCERTAINTY OF THE TRACK OF THE STORM SYSTEM. WEDNESDAY ISENTROPIC LIFT DWINDLES TOWARD THE WEST AS THE CLOSED LOW DEPARTS. HAVE PRECIP. CHANCES HIGHEST IN THE EAST WHERE THE FORCING FOR LIFT IS BEST WITH CHANCES DECLINING TO THE WEST. THROUGH THE DAY PRECIP. CHANCES DECLINE ACROSS THE AREA AS THE CLOSED LOW MOVES FURTHER EAST...WITH THE PRECIP. CHANCES COMING TO AN END OVER THE FAR EAST BY EARLY EVENING. FOR THURSDAY THROUGH MONDAY AN UPPER LEVEL SHORT WAVE RIDGE MOVES OVER THE AREA THURSDAY BEHIND THE EXITING STORM SYSTEM. BY THURSDAY NIGHT THE UPPER LEVEL FLOW TURNS TO THE NORTHWEST AHEAD OF THE NEXT UPPER LEVEL TROUGH MOVING ACROSS THE INTER MOUNTAIN WEST. PRECIPITATION CHANCES RETURN TO THE EASTERN PART OF THE AREA THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A COUPLE UPPER LEVEL SHORT WAVE TROUGHS MOVE OVER THE AREA. WITH THE LOW LEVEL JET AND ISENTROPIC LIFT AHEAD OF THE TROUGHS...A FEW SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE OVER THE EASTERN PART OF THE AREA. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD...WITH A WARMING TREND THURSDAY AND FRIDAY. COOLER BUT ABOVE NORMAL TEMPERATURES RETURN THROUGH THE REST OF THE PERIOD BEHIND A COLD FRONT THAT MOVES THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 553 PM MDT MON APR 2 2012 LOW CLOUDS TO THE NORTH AND AN AREA OF THUNDERSTORMS TO THE SOUTH WILL CONVERGE OVER THE AREA IN THE NEXT FEW HOURS. RUC IS HANDLING THE CLOUDS FAIRLY WELL SO HAVE USED THIS MODEL AS WELL AS THE HRRR CONCERNING THE PRECIPITATION. LOOK FOR MVFR CIGS AT BOTH TERMINALS IN THE 02-04Z RANGE WITH PRECIPITATION OCCURRING AROUND 03Z AT KGLD AND 08Z AT KMCK. THERE WILL BE A FEW HOURS OF POSSIBLE IFR AT KGLD AFTER THE PRECIPITATION HAS ENDED...THEN ANOTHER ROUND OF PRECIPITATION IN THE LATE MORNING INTO THE EARLY AFTERNOON. PRECIPITATION WILL END AROUND 12Z AT KMCK THEN HOLD OFF AGAIN UNTIL AFTER THIS TAF PERIOD. MVFR CIGS WILL HOLD THROUGH THE REST OF THE PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ090>092. KS...WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR NEZ079>081. && $$ UPDATE...007 SHORT TERM...FS LONG TERM....JTL AVIATION...BAS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
611 AM CDT SUN APR 1 2012 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 333 AM CDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 333 AM CDT SUN APR 1 2012 THE APRIL 1 2012 00Z 300 HPA SYNOPTIC MAP SHOWED A LARGE ANTICYCLONIC CURVED JET EXTENDING ACROSS THE WESTERN UNITED STATES AND INTO THE CANADIAN PRAIRIE PROVINCES. A JET STREAK OF AROUND 130-140 KT WAS OBSERVED FROM KREV TO KBOI. AT 500 HPA, AN AMPLIFIED TROUGH ASSOCIATED WITH THE JET STREAK WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND INTO NORTHERN CALIFORNIA. CONSIDERABLE COLD AIR ADVECTION WITH 500 HPA DELTA TEMPERATURES AROUND 10 DEG C WAS OBSERVED ACROSS THE PACIFIC NORTHWEST ALONG WITH SIGNIFICANT HEIGHT FALLS. MORE LOCALLY AND AT LOWER LEVELS, A WARM AND DRY PLUME AT 700 AND 850 HPA PREVAILED ACROSS THE HIGH PLAINS. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS EASTERN COLORADO. A DRYLINE ASSOCIATED WITH THIS FEATURE WAS LOCATED ACROSS THE SOUTHERN HIGH PLAINS AS WELL. THIS MORNING: AS WITH LAST NIGHT, HAVE FOLLOWED HRRR GUIDANCE IN CONCERNING THE POTENTIAL FOR PATCHY FOG FORMATION THIS MORNING. THIS MODEL HAS BEEN TRENDING WELL AS SITES AROUND KANSAS AND OKLAHOMA HAVE BEEN REPORTING BR THROUGH THE OVERNIGHT HOURS. I DID, HOWEVER, TAKE A MORE CONSERVATIVE APPROACH AS FAR AS DENSE FOG IS CONCERNED AND STUCK WITH PATCHY RATHER THAN +FG AS THE WINDS HAVE REMAINED ELEVATED THIS MORNING, WHICH COULD LIMIT THE OVERALL FOG INTENSITY. RECENT LAMP GUIDANCE AND RUC VIS OUTPUT SEEMS TO AGREE WITH THIS APPROACH AS WELL. FOG CONCERNS WILL BE OVER BY MID MORNING IF NOT SOONER. TODAY: UNPLEASANTLY WARM TEMPERATURES ARE EXPECTED TODAY. I SAY UNPLEASANT BECAUSE IT WILL FEEL DOWN RIGHT "HOT" RELATIVE TO THE BEGINNING OF APRIL. I DID TAKE THE COOLER SIDE OF MOS GUIDANCE AS BOISE VERIFICATION STILL SHOWS A WARM BIAS FROM THE MODELS. ONE REASON AS SUGGESTED FROM YESTERDAYS DAY SHIFT IS THAT EVAPOTRANSPIRATION FROM A RECENT HEAVY RAINFALL EVENT IS SLOWING DOWN HEAT FLUXES. IN ADDITION, DEWPOINTS ARE RUNNING AROUND 60 DEG F THIS MORNING SO THE ATMOSPHERE DOES HAVE SOME MOISTURE WHICH WILL RETARD SENSIBLE HEATING. THESE DEWPOINTS WILL LOWER AS THE DRYLINE WILL MIX EAST THROUGH THE AFTERNOON. CONVECTION IS NOT EXPECTED ALONG THE DRYLINE AS UPPER LEVEL RIDGING CONTINUES AND SUBSIDE PREVAILS AHEAD OF A WESTERN TROUGH. SOME RECORDS COULD BE IN JEOPARDY TODAY WHICH HAS BEEN HIGHLIGHTED IN THE CLIMATE SECTION BELOW. ANOTHER CONCERN FOR TODAY IS WINDS. THE 00Z GFS IS STRONGER WITH 850 HPA WINDS COMPARED TO THE 00Z NAM. THE ATMOSPHERE WILL BECOME WELL MIXED THIS AFTERNOON IN THE WAKE OF THE DRYLINE, HOWEVER WINDS PER THE MESOSCALE MODELS ARE NOT THAT IMPRESSIVE AND USING MIX DOWN TECHNIQUES SHOWS THAT A MARGINAL OR SUB MARGINAL WIND ADVISORY SPEEDS ARE POSSIBLE ACROSS THE WESTERN AND CENTRAL SECTIONS OF THE CWFA TODAY. AS A RESULT, DID NOT ISSUE A WIND ADVISORY FOR TODAY. LASTLY, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY WHICH IS ADDRESSED BELOW IN THE FIRE WEATHER SECTION. TONIGHT: WINDS WILL GRADUALLY VEER OVERNIGHT AHEAD OF AN APPROACHING SIGNIFICANT COLD FRONT. TEMPERATURES WILL BE MILD AND GENERALLY IN THE 40S DEG F WEST TO 50S DEG F EAST. NO PRECIPITATION IS EXPECTED DURING THIS TIME FRAME AS DYNAMICS WILL NOT ARRIVE UNTIL AS DESCRIBED IN THE LONG TERM SECTION. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 243 AM CDT SUN APR 1 2012 MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH QUICKLY MOVING AN UPPER LEVEL TROUGH WHICH WAS LOCATED JUST OFF THE WEST COAST OF CALIFORNIA TO NEAR THE FOUR CORNERS REGION BY 06Z MONDAY. THIS UPPER LEVEL SYSTEM THEN DEEPENS AS IT CROSSES NEW MEXICO DURING THE DAY ON MONDAY. BY 00Z TUESDAY THE GFS, ECMWF, AND NAM ALL PLACE THIS UPPER LEVEL LOW NEAR EAST CENTRAL NEW MEXICO. AHEAD OF THIS DEEPENING UPPER LEVEL SYSTEM A COLD FRONT WILL BE MOVING SOUTH ACROSS WESTERN KANSAS DURING THE DAY AND BASED ON THE GFS AND NAM THIS FRONTAL BOUNDARY WILL BE LOCATED NEAR THE OKLAHOMA BORDER AND SOUTH CENTRAL KANSAS BY 00Z TUESDAY. BOTH MODELS THIS MORNING ARE IN GOOD AGREEMENT WITH CONVECTION DEVELOPING ALONG THIS COLD FRONT LATE DAY DESPITE THE DIFFERENCES IN THE LOCATION OF THIS FRONT MONDAY EVENING. THE CONVECTION LATE DAY DOES APPEAR REASONABLE GIVEN THE MOISTURE RETURN FORECAST AHEAD OF THIS FRONT, IMPROVING LOW LEVEL FORCING AND LATE DAY INSTABILITY. AS A RESULT WILL CONTINUE TO FAVOR KEEPING A MENTION OF LATE DAY STORMS ACROSS SOUTH CENTRAL KANSAS AFTER 21Z. DECENT MID LEVEL INSTABILITY AT 00Z TUESDAY AND CAPES ARE FORECAST TO BE AT OR ABOVE 2000 J/KG. MARGINAL SHEAR HOWEVER IS EXPECTED WITH 0-6KM SHEAR AT OR BELOW 30KTS. STILL GIVEN SOME LATE DAY HEATING AND IMPROVING FORCING ALONG THIS BOUNDARY DO THINK A FEW STORMS THAT DO DEVELOP ALONG THIS FRONT LATE DAY MAY BECOME SEVERE WITH HAIL UP TO QUARTER SIZE BEING THE MAIN HAZARD. NORTH/NORTHWEST OF THIS COLD FRONT LATE MONDAY GUSTY NORTHERLY WINDS ARE EXPECTED TO INCREASE INTO THE 25 TO 35 MPH RANGE AS AN AREA OF LOW PRESSURE AT THE SURFACE DEEPENS ALONG THIS COLD FRONT ACROSS THE PANHANDLE OF TEXAS. THIS WILL BEGIN TO USHER IN SOME COOLER AIR LATE IN THE DAY SO TEMPERATURES BEHIND THIS COLD FRONT ARE EXPECTED TO STRUGGLE INTO THE UPPER 60S TO LOWER 70S. AHEAD OF THIS FRONT LOWER 80S STILL APPEAR LIKELY. THE CHANCES FOR PRECIPITATION THEN SPREADS NORTHWARD ACROSS ALL OF WESTERN AND MUCH OF NORTH CENTRAL KANSAS MONDAY NIGHT AS THE UPPER LEVEL LOW BEGINS TO LOWLY MOVE EAST INTO THE PANHANDLE OF TEXAS AND WARM AIR ADVECTION AND MOISTURE IMPROVES ACROSS WESTERN KANSAS DURING THE OVERNIGHT HOURS MONDAY NIGHT. FROM TUESDAY THROUGH EARLY WEDNESDAY A SERIES OF UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER LOW AS IT MOVES FROM THE PANHANDLE OF TEXAS INTO SOUTH CENTRAL KANSAS. MOISTURE AND LIFT (WARM AIR ADVECTION, ISENTROPIC LIFT, 850-700MB FRONTOGENESIS) CONTINUES SO HAVE THEREFORE RAISE PRECIPITATION CHANCES ACROSS THE ENTIRE AREA. BY LATE WEDNESDAY AN UPPER LEVEL SHORT WAVE RIDGE WILL BEGIN TO BUILD INTO THE ROCKIES AS THE UPPER LOW CONTINUES TO TRACK EASTWARD ACROSS EASTERN KANSAS. SKIES ARE EXPECTED TO CLEAR FROM WEST TO EAST AS THE PRECIPITATION ENDS. TEMPERATURES WEDNESDAY NIGHT HAS THE POTENTIAL TO FALL BACK TO NEAR FREEZING IF SKIES CLEAR QUICK ENOUGH AND WIND GO LIGHT BUT GIVEN THE TIMING ISSUES OF THE UPPER LOW HAVE DECIDED TO STAY CLOSE TO LATEST ALLBLEND. ON THURSDAY AND FRIDAY A WARMING TREND CAN BE EXPECTED ACROSS WESTERN KANSAS AS THE UPPER LEVEL RIDGE AXIS BUILDS EAST OUT INTO THE PLAINS AND WESTERLY DOWN SLOPE FLOW IMPROVES && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 608 AM CDT SUN APR 1 2012 AREAS OF LOW IFR STATUS AND PATCHY FOG HAVE BEEN DEVELOPING ACROSS MUCH OF SOUTHWEST KANSAS EARLIER THIS MORNING. THIS WAS OCCURRING EAST OF A DRYLINE WHICH WAS LOCATED NEAR THE COLORADO BORDER. THE NAM/RUC WERE IN GOOD AGREEMENT WITH THE DRYLINE QUICKLY MOVING EAST TODAY. WHAT STATUS/FOG THAT WILL DEVELOP BETWEEN 12Z AND 14Z AT DDC AND GCK WILL QUICKLY ERODE AS A DRIER SOUTHWEST WIND DEVELOPS. THESE SOUTHWEST WINDS WILL THEN INCREASE THROUGH THE DAY INTO THE 15 TO 25 KNOT RANGE. AFTER SUNSET...WINDS WILL DECREASE BACK INTO THE 10-15 KNOT RANGE AND BACK MORE TO THE SOUTH. && .FIRE WEATHER... ISSUED AT 333 AM CDT SUN APR 1 2012 AFTER COORDINATION WITH SURROUNDING WFO`S, HAVE CONTINUED THE RFW TODAY AND ADDED CLARK COUNTY IN. THE EASTERN COLUMN OF COUNTIES IS A BIT MARGINAL AS RH`S WILL BE IN THE 15 TO 17 PERCENT RANGE. DECIDED TO ERROR ON THE SIDE OF CAUTION AND KEEP THE COUNTIES IN THE WARNING AS TODAYS HIGHS WILL BE VERY WARM AND THE MODELS TYPICALLY UNDER FORECAST DEWPOINTS IN ASSOCIATION WITH A MIXING DRYLINE AND ADIABATIC COMPRESSIONAL WARMING. && .CLIMATE... ISSUED AT 333 AM CDT SUN APR 1 2012 A VERY ANOMALOUS DAY OF EXTREMELY WARM TEMPERATURES IS EXPECTED TODAY. POSITIVE TEMPERATURE DEVIATIONS OF 20 TO 30 DEGREES IS LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS. SOME RECORDS COULD BE BROKEN TODAY. CLIMATE RECORDS IS AS FOLLOWS: RECORD (YEAR)..........................FORECAST HIGH FOR TODAY DODGE CITY: 88 (1940, 1964)............89 MEDICINE LODGE: 93 (1946)..............86 GARDEN CITY: 87 (1964).................90 ELKHART 89 (1946)......................90 && .PRELIMINARY POINT TEMPS/POPS... DDC 89 52 71 41 / 0 10 10 60 GCK 90 50 68 40 / 0 10 10 60 EHA 90 49 63 38 / 0 10 20 50 LBL 90 50 68 40 / 0 10 20 60 HYS 88 54 70 41 / 0 10 10 50 P28 86 57 79 51 / 0 10 40 60 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM....BURGERT AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WICHITA KS
337 AM CDT SUN APR 1 2012 .DISCUSSION... TODAY-TONIGHT: UNSEASONABLY WARM TEMPERTURES ARE EXPECTED WITH FORECAST MAXES GETTING CLOSE TO RECORDS AT SEVERAL LOCATIONS. ANTICIPATE LOW CLOUDS WILL THIN/ERODE BY MIDDAY WITH TEMPERATURES BASED ON WARMER MODEL OUTPUT STATISTICS/BIASES FROM YESTERDAY. FAIR AMOUNT OF SPREAD IN SHORT TERM MODELS/MODEL OUTPUT STATISTICS WITH WIND SPEEDS DURING THE DAY...WITH SOME MODEL OUTPUT STATISTICS APPROACHING ADVISORY CRITERIA AT 2100 UTC. LOW CLOUDS MAY DEVELOP AGAIN TONIGHT IN SOUTHEAST KS MON-MON NIGHT: GOING TREND OF POPS MON AFTERNOON ALONG SAGGING FRONT STILL LOOKS ON TARGET. STILL FAIR AMOUNT OF WIGGLE ROOM WHERE BOUNDARY WILL BE WHEN INITIATION OCCURS...AND SHADED POPS BASED ON MODEL CONSENSUS. WHILE BOTH GFS/NAM SHOW GOOD INSTABILITY...DEEP LAYER SHEAR AND HODOGRAPHS ARE NOT FAVORABLE FOR SEVERE. HOWEVER GIVEN PROXIMITY TO UPPER LOW AND EFFECT OF EVEN SMALL CHANGES TO ITS TRACK...WILL CONTINUE MENTION OF STRONG STORMS IN HAZARDOUS WEATHER OUTLOOK FOR MON AFTERNOON-EVENING. VERY MILD TEMPERATURES ANTICIPATED MON NIGHT WITH WINDS STAYING UP A BIT AND INFLUX OF LOW LEVEL MOISTURE. TUE-WED: LATEST RUNS LESS LIKELY TO SUPPORT SIGNIFICANT DRY SLOT WHICH COULD SIGNIFICANTLY IMPACT POPS/TEMPERATURES. PRECIPITATION CHANCES SHOULD BE HIGHEST ON W-NW-NE SIDE OF UPPER LOW...AND SHADED HIGHEST POPS ACROSS CENTRAL KS. TEMPERATURES SOMEWHAT TRICKY WITH COMBO OF COLD AIR ADVECTION/CLOUDS AND PRECIPITATION. THU-SAT: ALTHOUGH TEMPERATURES WILL BE COOLER THIS PERIOD...VALUES WILL STILL BE ABOVE NORMAL. LATEST MODELS STILL HINTING AT SOME PRECIPITATION POTENTIAL ON FRI NIGHT/SAT WITH FRONT MOVING THROUGH THE AREA...ALTHOUGH THERE IS SOME QUESTION AS TO THE AMOUNT/DEPTH OF MOISTURE. -HOWERTON && .FIRE WEATHER... DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS ON TODAY...THE GRASSLAND FIRE DANGER RISK IS EXPECTED TO BE ONLY SLIGHTLY ELEVATED DUE TO THE EARLY SPRING GREEN-UP.-HOWERTON && .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU MAIN CONCERN REMAINS POTENTIAL FOR LOW STRATUS. LEE TROUGH WILL ALLOW LIGHT SOUTH-SOUTHEASTERLY WINDS TO CONTINUE OVERNIGHT WITH INCREASING BOUNDARY LAYER MOISTURE. THIS SHOULD RESULT IN LIFR-IFR STRATUS DEVELOPMENT OVER MUCH OF THE AREA DURING THE EARLY AM HOURS SUNDAY. THIS IS SUPPORTED IN THE NAM...GFS...RUC...AND 3KM HRRR MODELS. FORECAST CONFIDENCE IS ABOVE AVERAGE GIVEN THE LOW STRATUS OCCURRENCE IN CENTRAL/SOUTHWEST OK AND NORTH CENTRAL TEXAS SATURDAY MORNING. THE STRATUS LOOKS TO BURN OFF TOWARD MIDDAY SUNDAY. BETTER MIXING AND NEAR FULL SUNSHINE SUNDAY AFTERNOON SHOULD RESULT IN SOUTHERLY GUSTS ~25 KT MOST OF THE AREA. JMC && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 85 63 80 54 / 0 0 20 60 HUTCHINSON 86 60 78 51 / 0 0 20 50 NEWTON 84 63 79 53 / 0 0 20 50 ELDORADO 84 66 82 55 / 0 0 20 50 WINFIELD-KWLD 86 65 85 57 / 0 0 20 60 RUSSELL 88 56 70 45 / 0 0 10 30 GREAT BEND 87 55 72 44 / 0 0 20 40 SALINA 87 61 76 50 / 0 0 20 40 MCPHERSON 86 61 77 50 / 0 0 20 50 COFFEYVILLE 87 68 88 62 / 0 10 10 40 CHANUTE 86 65 88 60 / 0 10 10 40 IOLA 86 65 88 59 / 0 10 10 30 PARSONS-KPPF 87 67 88 60 / 0 10 10 40 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
334 AM CDT SUN APR 1 2012 ...UPDATED SYNOPSIS/SHORT TERM/FIRE WEATHER/CLIMATE DISCUSSIONS... .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 333 AM CDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 333 AM CDT SUN APR 1 2012 THE APRIL 1 2012 00Z 300 HPA SYNOPTIC MAP SHOWED A LARGE ANTICYCLONIC CURVED JET EXTENDING ACROSS THE WESTERN UNITED STATES AND INTO THE CANADIAN PRAIRIE PROVINCES. A JET STREAK OF AROUND 130-140 KT WAS OBSERVED FROM KREV TO KBOI. AT 500 HPA, AN AMPLIFIED TROUGH ASSOCIATED WITH THE JET STREAK WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND INTO NORTHERN CALIFORNIA. CONSIDERABLE COLD AIR ADVECTION WITH 500 HPA DELTA TEMPERATURES AROUND 10 DEG C WAS OBSERVED ACROSS THE PACIFIC NORTHWEST ALONG WITH SIGNIFICANT HEIGHT FALLS. MORE LOCALLY AND AT LOWER LEVELS, A WARM AND DRY PLUME AT 700 AND 850 HPA PREVAILED ACROSS THE HIGH PLAINS. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS EASTERN COLORADO. A DRYLINE ASSOCIATED WITH THIS FEATURE WAS LOCATED ACROSS THE SOUTHERN HIGH PLAINS AS WELL. THIS MORNING: AS WITH LAST NIGHT, HAVE FOLLOWED HRRR GUIDANCE IN CONCERNING THE POTENTIAL FOR PATCHY FOG FORMATION THIS MORNING. THIS MODEL HAS BEEN TRENDING WELL AS SITES AROUND KANSAS AND OKLAHOMA HAVE BEEN REPORTING BR THROUGH THE OVERNIGHT HOURS. I DID, HOWEVER, TAKE A MORE CONSERVATIVE APPROACH AS FAR AS DENSE FOG IS CONCERNED AND STUCK WITH PATCHY RATHER THAN +FG AS THE WINDS HAVE REMAINED ELEVATED THIS MORNING, WHICH COULD LIMIT THE OVERALL FOG INTENSITY. RECENT LAMP GUIDANCE AND RUC VIS OUTPUT SEEMS TO AGREE WITH THIS APPROACH AS WELL. FOG CONCERNS WILL BE OVER BY MID MORNING IF NOT SOONER. TODAY: UNPLEASANTLY WARM TEMPERATURES ARE EXPECTED TODAY. I SAY UNPLEASANT BECAUSE IT WILL FEEL DOWN RIGHT "HOT" RELATIVE TO THE BEGINNING OF APRIL. I DID TAKE THE COOLER SIDE OF MOS GUIDANCE AS BOISE VERIFICATION STILL SHOWS A WARM BIAS FROM THE MODELS. ONE REASON AS SUGGESTED FROM YESTERDAYS DAY SHIFT IS THAT EVAPOTRANSPIRATION FROM A RECENT HEAVY RAINFALL EVENT IS SLOWING DOWN HEAT FLUXES. IN ADDITION, DEWPOINTS ARE RUNNING AROUND 60 DEG F THIS MORNING SO THE ATMOSPHERE DOES HAVE SOME MOISTURE WHICH WILL RETARD SENSIBLE HEATING. THESE DEWPOINTS WILL LOWER AS THE DRYLINE WILL MIX EAST THROUGH THE AFTERNOON. CONVECTION IS NOT EXPECTED ALONG THE DRYLINE AS UPPER LEVEL RIDGING CONTINUES AND SUBSIDE PREVAILS AHEAD OF A WESTERN TROUGH. SOME RECORDS COULD BE IN JEOPARDY TODAY WHICH HAS BEEN HIGHLIGHTED IN THE CLIMATE SECTION BELOW. ANOTHER CONCERN FOR TODAY IS WINDS. THE 00Z GFS IS STRONGER WITH 850 HPA WINDS COMPARED TO THE 00Z NAM. THE ATMOSPHERE WILL BECOME WELL MIXED THIS AFTERNOON IN THE WAKE OF THE DRYLINE, HOWEVER WINDS PER THE MESOSCALE MODELS ARE NOT THAT IMPRESSIVE AND USING MIX DOWN TECHNIQUES SHOWS THAT A MARGINAL OR SUB MARGINAL WIND ADVISORY SPEEDS ARE POSSIBLE ACROSS THE WESTERN AND CENTRAL SECTIONS OF THE CWFA TODAY. AS A RESULT, DID NOT ISSUE A WIND ADVISORY FOR TODAY. LASTLY, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY WHICH IS ADDRESSED BELOW IN THE FIRE WEATHER SECTION. TONIGHT: WINDS WILL GRADUALLY VEER OVERNIGHT AHEAD OF AN APPROACHING SIGNIFICANT COLD FRONT. TEMPERATURES WILL BE MILD AND GENERALLY IN THE 40S DEG F WEST TO 50S DEG F EAST. NO PRECIPITATION IS EXPECTED DURING THIS TIME FRAME AS DYNAMICS WILL NOT ARRIVE UNTIL AS DESCRIBED IN THE LONG TERM SECTION. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 243 AM CDT SUN APR 1 2012 MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH QUICKLY MOVING AN UPPER LEVEL TROUGH WHICH WAS LOCATED JUST OFF THE WEST COAST OF CALIFORNIA TO NEAR THE FOUR CORNERS REGION BY 06Z MONDAY. THIS UPPER LEVEL SYSTEM THEN DEEPENS AS IT CROSSES NEW MEXICO DURING THE DAY ON MONDAY. BY 00Z TUESDAY THE GFS, ECMWF, AND NAM ALL PLACE THIS UPPER LEVEL LOW NEAR EAST CENTRAL NEW MEXICO. AHEAD OF THIS DEEPENING UPPER LEVEL SYSTEM A COLD FRONT WILL BE MOVING SOUTH ACROSS WESTERN KANSAS DURING THE DAY AND BASED ON THE GFS AND NAM THIS FRONTAL BOUNDARY WILL BE LOCATED NEAR THE OKLAHOMA BORDER AND SOUTH CENTRAL KANSAS BY 00Z TUESDAY. BOTH MODELS THIS MORNING ARE IN GOOD AGREEMENT WITH CONVECTION DEVELOPING ALONG THIS COLD FRONT LATE DAY DESPITE THE DIFFERENCES IN THE LOCATION OF THIS FRONT MONDAY EVENING. THE CONVECTION LATE DAY DOES APPEAR REASONABLE GIVEN THE MOISTURE RETURN FORECAST AHEAD OF THIS FRONT, IMPROVING LOW LEVEL FORCING AND LATE DAY INSTABILITY. AS A RESULT WILL CONTINUE TO FAVOR KEEPING A MENTION OF LATE DAY STORMS ACROSS SOUTH CENTRAL KANSAS AFTER 21Z. DECENT MID LEVEL INSTABILITY AT 00Z TUESDAY AND CAPES ARE FORECAST TO BE AT OR ABOVE 2000 J/KG. MARGINAL SHEAR HOWEVER IS EXPECTED WITH 0-6KM SHEAR AT OR BELOW 30KTS. STILL GIVEN SOME LATE DAY HEATING AND IMPROVING FORCING ALONG THIS BOUNDARY DO THINK A FEW STORMS THAT DO DEVELOP ALONG THIS FRONT LATE DAY MAY BECOME SEVERE WITH HAIL UP TO QUARTER SIZE BEING THE MAIN HAZARD. NORTH/NORTHWEST OF THIS COLD FRONT LATE MONDAY GUSTY NORTHERLY WINDS ARE EXPECTED TO INCREASE INTO THE 25 TO 35 MPH RANGE AS AN AREA OF LOW PRESSURE AT THE SURFACE DEEPENS ALONG THIS COLD FRONT ACROSS THE PANHANDLE OF TEXAS. THIS WILL BEGIN TO USHER IN SOME COOLER AIR LATE IN THE DAY SO TEMPERATURES BEHIND THIS COLD FRONT ARE EXPECTED TO STRUGGLE INTO THE UPPER 60S TO LOWER 70S. AHEAD OF THIS FRONT LOWER 80S STILL APPEAR LIKELY. THE CHANCES FOR PRECIPITATION THEN SPREADS NORTHWARD ACROSS ALL OF WESTERN AND MUCH OF NORTH CENTRAL KANSAS MONDAY NIGHT AS THE UPPER LEVEL LOW BEGINS TO LOWLY MOVE EAST INTO THE PANHANDLE OF TEXAS AND WARM AIR ADVECTION AND MOISTURE IMPROVES ACROSS WESTERN KANSAS DURING THE OVERNIGHT HOURS MONDAY NIGHT. FROM TUESDAY THROUGH EARLY WEDNESDAY A SERIES OF UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER LOW AS IT MOVES FROM THE PANHANDLE OF TEXAS INTO SOUTH CENTRAL KANSAS. MOISTURE AND LIFT (WARM AIR ADVECTION, ISENTROPIC LIFT, 850-700MB FRONTOGENESIS) CONTINUES SO HAVE THEREFORE RAISE PRECIPITATION CHANCES ACROSS THE ENTIRE AREA. BY LATE WEDNESDAY AN UPPER LEVEL SHORT WAVE RIDGE WILL BEGIN TO BUILD INTO THE ROCKIES AS THE UPPER LOW CONTINUES TO TRACK EASTWARD ACROSS EASTERN KANSAS. SKIES ARE EXPECTED TO CLEAR FROM WEST TO EAST AS THE PRECIPITATION ENDS. TEMPERATURES WEDNESDAY NIGHT HAS THE POTENTIAL TO FALL BACK TO NEAR FREEZING IF SKIES CLEAR QUICK ENOUGH AND WIND GO LIGHT BUT GIVEN THE TIMING ISSUES OF THE UPPER LOW HAVE DECIDED TO STAY CLOSE TO LATEST ALLBLEND. ON THURSDAY AND FRIDAY A WARMING TREND CAN BE EXPECTED ACROSS WESTERN KANSAS AS THE UPPER LEVEL RIDGE AXIS BUILDS EAST OUT INTO THE PLAINS AND WESTERLY DOWN SLOPE FLOW IMPROVES && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1201 AM CDT SUN APR 1 2012 TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS 20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW AFTERNOON. && .FIRE WEATHER... ISSUED AT 333 AM CDT SUN APR 1 2012 AFTER COORDINATION WITH SURROUNDING WFO`S, HAVE CONTINUED THE RFW TODAY AND ADDED CLARK COUNTY IN. THE EASTERN COLUMN OF COUNTIES IS A BIT MARGINAL AS RH`S WILL BE IN THE 15 TO 17 PERCENT RANGE. DECIDED TO ERROR ON THE SIDE OF CAUTION AND KEEP THE COUNTIES IN THE WARNING AS TODAYS HIGHS WILL BE VERY WARM AND THE MODELS TYPICALLY UNDER FORECAST DEWPOINTS IN ASSOCIATION WITH A MIXING DRYLINE AND ADIABATIC COMPRESSIONAL WARMING. && .CLIMATE... ISSUED AT 333 AM CDT SUN APR 1 2012 A VERY ANOMALOUS DAY OF EXTREMELY WARM TEMPERATURES IS EXPECTED TODAY. POSITIVE TEMPERATURE DEVIATIONS OF 20 TO 30 DEGREES IS LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS. SOME RECORDS COULD BE BROKEN TODAY. CLIMATE RECORDS IS AS FOLLOWS: RECORD (YEAR)..........................FORECAST HIGH FOR TODAY DODGE CITY: 88 (1940, 1964)............89 MEDICINE LODGE: 93 (1946)..............86 GARDEN CITY: 87 (1964).................90 ELKHART 89 (1946)......................90 && .PRELIMINARY POINT TEMPS/POPS... DDC 89 52 74 41 / 0 10 10 60 GCK 90 50 69 40 / 0 10 10 50 EHA 90 49 66 38 / 0 10 20 50 LBL 90 50 71 40 / 0 10 20 50 HYS 88 54 72 41 / 0 10 10 50 P28 86 57 82 51 / 0 10 40 60 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM....BURGERT AVIATION...SUGDEN FIRE WEATHER...SUGDEN CLIMATE...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
333 AM CDT SUN APR 1 2012 ...UPDATED SYNOPSIS/SHORT TERM/FIRE WEATHER/CLIMATE DISCUSSIONS... .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 333 AM CDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 333 AM CDT SUN APR 1 2012 THE APRIL 1 2012 00Z 300 HPA SYNOPTIC MAP SHOWED A LARGE ANTICYCLONIC CURVED JET EXTENDING ACROSS THE WESTERN UNITED STATES AND INTO THE CANADIAN PRAIRIE PROVINCES. A JET STREAK OF AROUND 130-140 KT WAS OBSERVED FROM KREV TO KBOI. AT 500 HPA, AN AMPLIFIED TROUGH ASSOCIATED WITH THE JET STREAK WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND INTO NORTHERN CALIFORNIA. CONSIDERABLE COLD AIR ADVECTION WITH 500 HPA DELTA TEMPERATURES AROUND 10 DEG C WAS OBSERVED ACROSS THE PACIFIC NORTHWEST ALONG WITH SIGNIFICANT HEIGHT FALLS. MORE LOCALLY AND AT LOWER LEVELS, A WARM AND DRY PLUME AT 700 AND 850 HPA PREVAILED ACROSS THE HIGH PLAINS. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS EASTERN COLORADO. A DRYLINE ASSOCIATED WITH THIS FEATURE WAS LOCATED ACROSS THE SOUTHERN HIGH PLAINS AS WELL. THIS MORNING: AS WITH LAST NIGHT, HAVE FOLLOWED HRRR GUIDANCE IN CONCERNING THE POTENTIAL FOR PATCHY FOG FORMATION THIS MORNING. THIS MODEL HAS BEEN TRENDING WELL AS SITES AROUND KANSAS AND OKLAHOMA HAVE BEEN REPORTING BR THROUGH THE OVERNIGHT HOURS. I DID, HOWEVER, TAKE A MORE CONSERVATIVE APPROACH AS FAR AS DENSE FOG IS CONCERNED AND STUCK WITH PATCHY RATHER THAN +FG AS THE WINDS HAVE REMAINED ELEVATED THIS MORNING, WHICH COULD LIMIT THE OVERALL FOG INTENSITY. RECENT LAMP GUIDANCE AND RUC VIS OUTPUT SEEMS TO AGREE WITH THIS APPROACH AS WELL. FOG CONCERNS WILL BE OVER BY MID MORNING IF NOT SOONER. TODAY: UNPLEASANTLY WARM TEMPERATURES ARE EXPECTED TODAY. I SAY UNPLEASANT BECAUSE IT WILL FEEL DOWN RIGHT "HOT" RELATIVE TO THE BEGINNING OF APRIL. I DID TAKE THE COOLER SIDE OF MOS GUIDANCE AS BOISE VERIFICATION STILL SHOWS A WARM BIAS FROM THE MODELS. ONE REASON AS SUGGESTED FROM YESTERDAYS DAY SHIFT IS THAT EVAPOTRANSPIRATION FROM A RECENT HEAVY RAINFALL EVENT IS SLOWING DOWN HEAT FLUXES. IN ADDITION, DEWPOINTS ARE RUNNING AROUND 60 DEG F THIS MORNING SO THE ATMOSPHERE DOES HAVE SOME MOISTURE WHICH WILL RETARD SENSIBLE HEATING. THESE DEWPOINTS WILL LOWER AS THE DRYLINE WILL MIX EAST THROUGH THE AFTERNOON. CONVECTION IS NOT EXPECTED ALONG THE DRYLINE AS UPPER LEVEL RIDGING CONTINUES AND SUBSIDE PREVAILS AHEAD OF A WESTERN TROUGH. SOME RECORDS COULD BE IN JEOPARDY TODAY WHICH HAS BEEN HIGHLIGHTED IN THE CLIMATE SECTION BELOW. ANOTHER CONCERN FOR TODAY IS WINDS. THE 00Z GFS IS STRONGER WITH 850 HPA WINDS COMPARED TO THE 00Z NAM. THE ATMOSPHERE WILL BECOME WELL MIXED THIS AFTERNOON IN THE WAKE OF THE DRYLINE, HOWEVER WINDS PER THE MESOSCALE MODELS ARE NOT THAT IMPRESSIVE AND USING MIX DOWN TECHNIQUES SHOWS THAT A MARGINAL OR SUB MARGINAL WIND ADVISORY SPEEDS ARE POSSIBLE ACROSS THE WESTERN AND CENTRAL SECTIONS OF THE CWFA TODAY. AS A RESULT, DID NOT ISSUE A WIND ADVISORY FOR TODAY. LASTLY, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TODAY WHICH IS ADDRESSED BELOW IN THE FIRE WEATHER SECTION. TONIGHT: WINDS WILL GRADUALLY VEER OVERNIGHT AHEAD OF AN APPROACHING SIGNIFICANT COLD FRONT. TEMPERATURES WILL BE MILD AND GENERALLY IN THE 40S DEG F WEST TO 50S DEG F EAST. NO PRECIPITATION IS EXPECTED DURING THIS TIME FRAME AS DYNAMICS WILL NOT ARRIVE UNTIL AS DESCRIBED IN THE LONG TERM SECTION. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 PM CDT SAT MAR 31 2012 ON MONDAY AN ELONGATED UPPER LEVEL TROUGH WILL BEGIN TO GET CUTOFF AT THE BASE JUST SOUTH OF THE FOUR CORNERS REGION AND MOVE INTO NORTHEASTERN NEW MEXICO. THIS WILL ALLOW A COLD FRONT TO SURGE INTO SOUTHWESTERN KANSAS ON MONDAY MORNING, THEN ACROSS MUCH OF SOUTH CENTRAL KANSAS BY EVENING TO NEAR MEDICINE LODGE. PREFER THE FASTER FRONTAL MOVEMENT OF THE NAM/GFS THAN THE ECMWF BECAUSE OF THE STRONGER NORTHERN BRANCH WAVE MOVING ACROSS THE DAKOTAS. A FEW THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON ALONG AND AHEAD OF THE COLD FRONT, MAINLY EAST OF LINE FROM COLDWATER TO SAINT JOHN. IF STORMS FORM A FEW COULD HAVE SOME SMALL HAIL. HOWEVER IF THE FRONT DELAYS THE STORMS COULD BE STRONGER NEAR A COLD FRONT AND DRYLINE INTERSECTION. AHEAD OF THE COLD FRONT LOWS WILL BE MILD AND INTO THE UPPER 40S NORTHEAST AND MID 50S SOUTHEAST FA. HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE 60S NORTHWEST TO THE LOW TO MID 80S SOUTHEAST FA. FOR TUESDAY THE UPPER LOW MOVES NORTHEASTWARD SLOWLY INTO THE TEXAS PANHANDLE AND PARTS OF FAR SOUTHWESTERN KANSAS. THE GEM AND THE ECMWF ARE A BIT FASTER WITH THE UPPER LOW THAN THE GFS. RAIN SHOWERS AND A FEW THUNDERSTORMS WILL RAPIDLY SPREAD NORTH AHEAD OF THE UPPER LOW INTO SOUTHWEST AND SOUTH CENTRAL KANSAS. THE BEST CHANCES WILL OCCUR AFTER MIDNIGHT. A CHANCE FOR THUNDERSTORMS WITH SOME ELEVATED CAPE WILL BE MAINLY EAST OF A LINE FROM LARNED TO ASHLAND. SEVERE WEATHER IS NOT EXPECTED. LOWS ON TUESDAY MORNING LOOK TO BE IN THE UPPER 30S WEST TO NEAR 50 EAST FA. HIGHS ON TUESDAY WILL RANGE FROM NEAR 50 IN THE FAR WEST TO THE LOW TO MID 60S FAR EAST FA. ON WEDNESDAY THE UPPER LOW CONTINUES TO MOVE NORTHEAST AND INTO EASTERN KANSAS AND OKLAHOMA. LOWS IN MORNING WILL BE IN THE UPPER 30S FAR WEST TO THE MID AND UPPER 40S EAST. HIGH TEMPERATURES WILL RANGE FROM THE MID 60S WEST TO AROUND 60 NORTHEAST. RAIN CHANCES DIMINISH FROM WEST TO EAST WITH THE UPPER LOW. TOTAL RAINFALL COULD RANGE FROM ONE QUARTER TO OVER ONE HALF INCH WITH THE HIGHEST IN THE SOUTHEASTERN FA FROM LARNED TO ASHLAND. FOR THURSDAY THE UPPER LEVEL SHORTWAVE RIDGING WILL MOVE INTO THE PLAINS WITH A WARM UP BACK INTO THE 70S. ANOTHER UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY NORTHEASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS FOR FRIDAY PUSHING ANOTHER COLD FRONT ACROSS KANSAS ON SATURDAY AS IT MOVES INTO THE NORTHERN HIGH PLAINS. LITTLE IF ANY RAINFALL IS EXPECTED. HIGHS ON FRIDAY LOOK TO BE IN THE MID TO UPPER 70S WITH SLIGHTLY COOLER TEMPS ON SATURDAY TO AROUND 70. OVERNIGHT LOWS WILL BE IN THE 40S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1201 AM CDT SUN APR 1 2012 TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS 20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW AFTERNOON. && .FIRE WEATHER... ISSUED AT 333 AM CDT SUN APR 1 2012 AFTER COORDINATION WITH SURROUNDING WFO`S, HAVE CONTINUED THE RFW TODAY AND ADDED CLARK COUNTY IN. THE EASTERN COLUMN OF COUNTIES IS A BIT MARGINAL AS RH`S WILL BE IN THE 15 TO 17 PERCENT RANGE. DECIDED TO ERROR ON THE SIDE OF CAUTION AND KEEP THE COUNTIES IN THE WARNING AS TODAYS HIGHS WILL BE VERY WARM AND THE MODELS TYPICALLY UNDER FORECAST DEWPOINTS IN ASSOCIATION WITH A MIXING DRYLINE AND ADIABATIC COMPRESSIONAL WARMING. && .CLIMATE... ISSUED AT 333 AM CDT SUN APR 1 2012 A VERY ANOMALOUS DAY OF EXTREMELY WARM TEMPERATURES IS EXPECTED TODAY. POSITIVE TEMPERATURE DEVIATIONS OF 20 TO 30 DEGREES IS LIKELY ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS. SOME RECORDS COULD BE BROKEN TODAY. CLIMATE RECORDS IS AS FOLLOWS: RECORD (YEAR)..........................FORECAST HIGH FOR TODAY DODGE CITY: 88 (1940, 1964)............89 MEDICINE LODGE: 93 (1946)..............86 GARDEN CITY: 87 (1964).................90 ELKHART 89 (1946)......................90 && .PRELIMINARY POINT TEMPS/POPS... DDC 89 52 74 41 / 0 10 10 60 GCK 90 50 69 40 / 0 10 10 50 EHA 90 49 66 38 / 0 10 20 50 LBL 90 50 71 40 / 0 10 20 50 HYS 88 54 72 41 / 0 10 10 50 P28 86 57 82 51 / 0 10 40 60 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM....KRUSE AVIATION...SUGDEN FIRE WEATHER...SUGDEN CLIMATE...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
247 AM CDT SUN APR 1 2012 ...UPDATED LONG TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 321 PM CDT SAT MAR 31 2012 THE PRIMARY FORECAST CHALLENGES IN THE SHORT TERM ARE THE FOLLOWING: 1) EVALUATING THE PROBABILITY FOR PATCHY DENSE FOG SUNDAY MORNING IN THE RICH BUT SHALLOW LOW LEVEL MOISTURE FIELD IN SOUTH CENTRAL KANSAS; 2) DETERMINING HOW FAR EAST THE DRYLINE WILL PROGRESS ON SUNDAY AS CYCLOGENESIS OCCURS IN EASTERN COLORADO; 3) DETERMINING THE AREA WHERE RED FLAG CONDITIONS WILL BE MET SUNDAY AFTERNOON; AND 4) ANTICIPATING TEMPERATURES IN THE ANOMALOUSLY WARM AIR SUNDAY AFTERNOON. A MADDEN-JULIAN OSCILLATION CONTINUES TO MOVE DOWN THE SOUTH PACIFIC CONVERGENCE ZONE FROM NORTH OF AUSTRALIA INTO THE TROPICAL SOUTH PACIFIC. A TROPICAL CYCLONE WAS IN PROGRESS EAST OF VIET NAM ON THE TRAILING EDGE OF THE MADDEN-JULIAN OSCILLATION. THE GLOBAL MODELS ARE IN GOOD AGREEMENT IN MOVING THE MADDEN-JULIAN OSCILLATION INTO PHASE 8 OF THE WHEELER-HENDON PHASE SPACE DIAGRAM BY AROUND EASTER, AND THIS PATTERN FAVORS ANTICYCLONIC FLOW ALOFT IN THE NORTHERN ROCKIES. THE MODEL SOLUTIONS OF A SPLIT FLOW WITH AN ANTICYCLONICALLY BREAKING UPPER LEVEL CYCLONE WALLOWING INTO THE CENTRAL PART OF THE COUNTRY FOLLOWED BY A BUILDING RIDGE BACK INTO THE NORTHERN ROCKIES NEXT WEEKEND SEEM VERY REASONABLE. IN THE SHORTER TERM, THE MODELS ARE IN GOOD AGREEMENT WITH DIGGING THE SOUTHERN PART OF THE STRONG TROUGH INTO ARIZONA BY SUNDAY EVENING WHILE THE NORTHERN PORTION OF THE TROUGH LIFTS OUT INTO SASKATCHEWAN IN THE NORTHERN BRANCH OF THE WESTERLIES. THERE ALWAYS IS UNCERTAINTY ON HOW CLOSED UPPER LEVEL CYCLONES WILL EVOLVE WITH TIME, BUT THE SLOWER GFS SOLUTION PROBABLY IS FAIRLY GOOD. THE GFS LARGELY WAS USED FOR GRID MODIFICATIONS THROUGH SUNDAY. PRESSURES ALREADY ARE FALLING IN THE LEE OF THE ROCKIES THIS AFTERNOON, AND THE TROUGH WILL CONTINUE TO DEEPEN TONIGHT. LOW LEVEL MOISTURE WILL SLOSH BACK WESTWARD TONIGHT AS THE LOW LEVEL WINDS BACK, BUT THE MOISTURE FIELD WILL BE RATHER SHALLOW ACROSS MOST OF WESTERN KANSAS. BY SUNRISE, VEERING LOW LEVEL FLOW WILL BEGIN TO ERODE THE MOISTURE IN FAR WESTERN KANSAS, AND THE DRYLINE GRADUALLY WILL MIX EASTWARD DURING THE DAY. THE RICHEST LOW LEVEL MOISTURE WILL BE IN SOUTH CENTRAL KANSAS TONIGHT WITH DRY AIR ABOVE THE MOIST LAYER. LOW LEVEL WINDS WILL BE RELATIVELY LIGHT IN SOUTH CENTRAL KANSAS, AND THE MOISTURE MAY BE DEEP ENOUGH THAT THE HYDROLAPSE WILL FAVOR PATCHY FOG FORMATION BY SUNRISE. WHATEVER FOG DOES FORM WILL BURN OFF QUICKLY AS WINDS INCREASE DURING THE EARLY MORNING HOURS. PRESSURES WILL CONTINUE TO FALL IN THE LEE OF THE ROCKIES SUNDAY AS CYCLOGENESIS OCCURS IN NORTHEASTERN COLORADO. THE SHALLOW MOISTURE WILL MIX OUT AT LEAST AS FAR EAST AS DODGE CITY BY MID AFTERNOON, AND A VERY DEEPLY MIXED BOUNDARY LAYER WILL EVOLVE DURING THE DAY. H8 WINDS WILL INCREASE TO 30-35 KNOTS BY LATE MORNING, SO SURFACE WINDS IN THE 20 TO 25 KNOT RANGE WITH GUSTS INTO THE 30-35 KNOT RANGE SEEM REASONABLE. H8 DEWPOINTS WILL DROP TO NEAR -10C IN FAR WESTERN KANSAS WITH VALUES NEAR 0C AS FAR EAST AS DODGE CITY. WITH H8 TEMPERATURES ABOVE 25C IN THE DRY AIR, SURFACE TEMPERATURES WILL APPROACH RECORDS IN A FEW LOCATIONS. EVAPOTRANSPIRATION FROM VEGETATION MAY SHAVE TWO OR THREE DEGREES OFF MAXIMUM TEMPERATURES, BUT HIGHS NEAR 90 DEGREES ARE LIKELY. WINDS MAY APPROACH ADVISORY CRITERIA BY MID AFTERNOON AND WILL HAVE TO BE MONITORED FOR POSSIBLE HEADLINES BY SUBSEQUENT SHIFTS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 243 AM CDT SUN APR 1 2012 MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH QUICKLY MOVING AN UPPER LEVEL TROUGH WHICH WAS LOCATED JUST OFF THE WEST COAST OF CALIFORNIA TO NEAR THE FOUR CORNERS REGION BY 06Z MONDAY. THIS UPPER LEVEL SYSTEM THEN DEEPENS AS IT CROSSES NEW MEXICO DURING THE DAY ON MONDAY. BY 00Z TUESDAY THE GFS, ECMWF, AND NAM ALL PLACE THIS UPPER LEVEL LOW NEAR EAST CENTRAL NEW MEXICO. AHEAD OF THIS DEEPENING UPPER LEVEL SYSTEM A COLD FRONT WILL BE MOVING SOUTH ACROSS WESTERN KANSAS DURING THE DAY AND BASED ON THE GFS AND NAM THIS FRONTAL BOUNDARY WILL BE LOCATED NEAR THE OKLAHOMA BORDER AND SOUTH CENTRAL KANSAS BY 00Z TUESDAY. BOTH MODELS THIS MORNING ARE IN GOOD AGREEMENT WITH CONVECTION DEVELOPING ALONG THIS COLD FRONT LATE DAY DESPITE THE DIFFERENCES IN THE LOCATION OF THIS FRONT MONDAY EVENING. THE CONVECTION LATE DAY DOES APPEAR REASONABLE GIVEN THE MOISTURE RETURN FORECAST AHEAD OF THIS FRONT, IMPROVING LOW LEVEL FORCING AND LATE DAY INSTABILITY. AS A RESULT WILL CONTINUE TO FAVOR KEEPING A MENTION OF LATE DAY STORMS ACROSS SOUTH CENTRAL KANSAS AFTER 21Z. DECENT MID LEVEL INSTABILITY AT 00Z TUESDAY AND CAPES ARE FORECAST TO BE AT OR ABOVE 2000 J/KG. MARGINAL SHEAR HOWEVER IS EXPECTED WITH 0-6KM SHEAR AT OR BELOW 30KTS. STILL GIVEN SOME LATE DAY HEATING AND IMPROVING FORCING ALONG THIS BOUNDARY DO THINK A FEW STORMS THAT DO DEVELOP ALONG THIS FRONT LATE DAY MAY BECOME SEVERE WITH HAIL UP TO QUARTER SIZE BEING THE MAIN HAZARD. NORTH/NORTHWEST OF THIS COLD FRONT LATE MONDAY GUSTY NORTHERLY WINDS ARE EXPECTED TO INCREASE INTO THE 25 TO 35 MPH RANGE AS AN AREA OF LOW PRESSURE AT THE SURFACE DEEPENS ALONG THIS COLD FRONT ACROSS THE PANHANDLE OF TEXAS. THIS WILL BEGIN TO USHER IN SOME COOLER AIR LATE IN THE DAY SO TEMPERATURES BEHIND THIS COLD FRONT ARE EXPECTED TO STRUGGLE INTO THE UPPER 60S TO LOWER 70S. AHEAD OF THIS FRONT LOWER 80S STILL APPEAR LIKELY. THE CHANCES FOR PRECIPITATION THEN SPREADS NORTHWARD ACROSS ALL OF WESTERN AND MUCH OF NORTH CENTRAL KANSAS MONDAY NIGHT AS THE UPPER LEVEL LOW BEGINS TO LOWLY MOVE EAST INTO THE PANHANDLE OF TEXAS AND WARM AIR ADVECTION AND MOISTURE IMPROVES ACROSS WESTERN KANSAS DURING THE OVERNIGHT HOURS MONDAY NIGHT. FROM TUESDAY THROUGH EARLY WEDNESDAY A SERIES OF UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER LOW AS IT MOVES FROM THE PANHANDLE OF TEXAS INTO SOUTH CENTRAL KANSAS. MOISTURE AND LIFT (WARM AIR ADVECTION, ISENTROPIC LIFT, 850-700MB FRONTOGENESIS) CONTINUES SO HAVE THEREFORE RAISE PRECIPITATION CHANCES ACROSS THE ENTIRE AREA. BY LATE WEDNESDAY AN UPPER LEVEL SHORT WAVE RIDGE WILL BEGIN TO BUILD INTO THE ROCKIES AS THE UPPER LOW CONTINUES TO TRACK EASTWARD ACROSS EASTERN KANSAS. SKIES ARE EXPECTED TO CLEAR FROM WEST TO EAST AS THE PRECIPITATION ENDS. TEMPERATURES WEDNESDAY NIGHT HAS THE POTENTIAL TO FALL BACK TO NEAR FREEZING IF SKIES CLEAR QUICK ENOUGH AND WIND GO LIGHT BUT GIVEN THE TIMING ISSUES OF THE UPPER LOW HAVE DECIDED TO STAY CLOSE TO LATEST ALLBLEND. ON THURSDAY AND FRIDAY A WARMING TREND CAN BE EXPECTED ACROSS WESTERN KANSAS AS THE UPPER LEVEL RIDGE AXIS BUILDS EAST OUT INTO THE PLAINS AND WESTERLY DOWN SLOPE FLOW IMPROVES && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1201 AM CDT SUN APR 1 2012 TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS 20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 89 52 74 41 / 0 10 10 60 GCK 90 50 69 40 / 0 10 10 50 EHA 90 49 66 38 / 0 10 20 50 LBL 90 50 71 40 / 0 10 20 50 HYS 88 54 72 41 / 0 10 10 50 P28 86 57 82 51 / 0 10 40 60 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>088. && $$ UPDATE...RUTHI SYNOPSIS...RUTHI SHORT TERM...RUTHI LONG TERM....BURGERT AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1208 AM CDT SUN APR 1 2012 ...UPDATE TO AVIATION FOR 06Z TAFS... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 321 PM CDT SAT MAR 31 2012 THE PRIMARY FORECAST CHALLENGES IN THE SHORT TERM ARE THE FOLLOWING: 1) EVALUATING THE PROBABILITY FOR PATCHY DENSE FOG SUNDAY MORNING IN THE RICH BUT SHALLOW LOW LEVEL MOISTURE FIELD IN SOUTH CENTRAL KANSAS; 2) DETERMINING HOW FAR EAST THE DRYLINE WILL PROGRESS ON SUNDAY AS CYCLOGENESIS OCCURS IN EASTERN COLORADO; 3) DETERMINING THE AREA WHERE RED FLAG CONDITIONS WILL BE MET SUNDAY AFTERNOON; AND 4) ANTICIPATING TEMPERATURES IN THE ANOMALOUSLY WARM AIR SUNDAY AFTERNOON. A MADDEN-JULIAN OSCILLATION CONTINUES TO MOVE DOWN THE SOUTH PACIFIC CONVERGENCE ZONE FROM NORTH OF AUSTRALIA INTO THE TROPICAL SOUTH PACIFIC. A TROPICAL CYCLONE WAS IN PROGRESS EAST OF VIET NAM ON THE TRAILING EDGE OF THE MADDEN-JULIAN OSCILLATION. THE GLOBAL MODELS ARE IN GOOD AGREEMENT IN MOVING THE MADDEN-JULIAN OSCILLATION INTO PHASE 8 OF THE WHEELER-HENDON PHASE SPACE DIAGRAM BY AROUND EASTER, AND THIS PATTERN FAVORS ANTICYCLONIC FLOW ALOFT IN THE NORTHERN ROCKIES. THE MODEL SOLUTIONS OF A SPLIT FLOW WITH AN ANTICYCLONICALLY BREAKING UPPER LEVEL CYCLONE WALLOWING INTO THE CENTRAL PART OF THE COUNTRY FOLLOWED BY A BUILDING RIDGE BACK INTO THE NORTHERN ROCKIES NEXT WEEKEND SEEM VERY REASONABLE. IN THE SHORTER TERM, THE MODELS ARE IN GOOD AGREEMENT WITH DIGGING THE SOUTHERN PART OF THE STRONG TROUGH INTO ARIZONA BY SUNDAY EVENING WHILE THE NORTHERN PORTION OF THE TROUGH LIFTS OUT INTO SASKATCHEWAN IN THE NORTHERN BRANCH OF THE WESTERLIES. THERE ALWAYS IS UNCERTAINTY ON HOW CLOSED UPPER LEVEL CYCLONES WILL EVOLVE WITH TIME, BUT THE SLOWER GFS SOLUTION PROBABLY IS FAIRLY GOOD. THE GFS LARGELY WAS USED FOR GRID MODIFICATIONS THROUGH SUNDAY. PRESSURES ALREADY ARE FALLING IN THE LEE OF THE ROCKIES THIS AFTERNOON, AND THE TROUGH WILL CONTINUE TO DEEPEN TONIGHT. LOW LEVEL MOISTURE WILL SLOSH BACK WESTWARD TONIGHT AS THE LOW LEVEL WINDS BACK, BUT THE MOISTURE FIELD WILL BE RATHER SHALLOW ACROSS MOST OF WESTERN KANSAS. BY SUNRISE, VEERING LOW LEVEL FLOW WILL BEGIN TO ERODE THE MOISTURE IN FAR WESTERN KANSAS, AND THE DRYLINE GRADUALLY WILL MIX EASTWARD DURING THE DAY. THE RICHEST LOW LEVEL MOISTURE WILL BE IN SOUTH CENTRAL KANSAS TONIGHT WITH DRY AIR ABOVE THE MOIST LAYER. LOW LEVEL WINDS WILL BE RELATIVELY LIGHT IN SOUTH CENTRAL KANSAS, AND THE MOISTURE MAY BE DEEP ENOUGH THAT THE HYDROLAPSE WILL FAVOR PATCHY FOG FORMATION BY SUNRISE. WHATEVER FOG DOES FORM WILL BURN OFF QUICKLY AS WINDS INCREASE DURING THE EARLY MORNING HOURS. PRESSURES WILL CONTINUE TO FALL IN THE LEE OF THE ROCKIES SUNDAY AS CYCLOGENESIS OCCURS IN NORTHEASTERN COLORADO. THE SHALLOW MOISTURE WILL MIX OUT AT LEAST AS FAR EAST AS DODGE CITY BY MID AFTERNOON, AND A VERY DEEPLY MIXED BOUNDARY LAYER WILL EVOLVE DURING THE DAY. H8 WINDS WILL INCREASE TO 30-35 KNOTS BY LATE MORNING, SO SURFACE WINDS IN THE 20 TO 25 KNOT RANGE WITH GUSTS INTO THE 30-35 KNOT RANGE SEEM REASONABLE. H8 DEWPOINTS WILL DROP TO NEAR -10C IN FAR WESTERN KANSAS WITH VALUES NEAR 0C AS FAR EAST AS DODGE CITY. WITH H8 TEMPERATURES ABOVE 25C IN THE DRY AIR, SURFACE TEMPERATURES WILL APPROACH RECORDS IN A FEW LOCATIONS. EVAPOTRANSPIRATION FROM VEGETATION MAY SHAVE TWO OR THREE DEGREES OFF MAXIMUM TEMPERATURES, BUT HIGHS NEAR 90 DEGREES ARE LIKELY. WINDS MAY APPROACH ADVISORY CRITERIA BY MID AFTERNOON AND WILL HAVE TO BE MONITORED FOR POSSIBLE HEADLINES BY SUBSEQUENT SHIFTS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 PM CDT SAT MAR 31 2012 ON MONDAY AN ELONGATED UPPER LEVEL TROUGH WILL BEGIN TO GET CUTOFF AT THE BASE JUST SOUTH OF THE FOUR CORNERS REGION AND MOVE INTO NORTHEASTERN NEW MEXICO. THIS WILL ALLOW A COLD FRONT TO SURGE INTO SOUTHWESTERN KANSAS ON MONDAY MORNING, THEN ACROSS MUCH OF SOUTH CENTRAL KANSAS BY EVENING TO NEAR MEDICINE LODGE. PREFER THE FASTER FRONTAL MOVEMENT OF THE NAM/GFS THAN THE ECMWF BECAUSE OF THE STRONGER NORTHERN BRANCH WAVE MOVING ACROSS THE DAKOTAS. A FEW THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON ALONG AND AHEAD OF THE COLD FRONT, MAINLY EAST OF LINE FROM COLDWATER TO SAINT JOHN. IF STORMS FORM A FEW COULD HAVE SOME SMALL HAIL. HOWEVER IF THE FRONT DELAYS THE STORMS COULD BE STRONGER NEAR A COLD FRONT AND DRYLINE INTERSECTION. AHEAD OF THE COLD FRONT LOWS WILL BE MILD AND INTO THE UPPER 40S NORTHEAST AND MID 50S SOUTHEAST FA. HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE 60S NORTHWEST TO THE LOW TO MID 80S SOUTHEAST FA. FOR TUESDAY THE UPPER LOW MOVES NORTHEASTWARD SLOWLY INTO THE TEXAS PANHANDLE AND PARTS OF FAR SOUTHWESTERN KANSAS. THE GEM AND THE ECMWF ARE A BIT FASTER WITH THE UPPER LOW THAN THE GFS. RAIN SHOWERS AND A FEW THUNDERSTORMS WILL RAPIDLY SPREAD NORTH AHEAD OF THE UPPER LOW INTO SOUTHWEST AND SOUTH CENTRAL KANSAS. THE BEST CHANCES WILL OCCUR AFTER MIDNIGHT. A CHANCE FOR THUNDERSTORMS WITH SOME ELEVATED CAPE WILL BE MAINLY EAST OF A LINE FROM LARNED TO ASHLAND. SEVERE WEATHER IS NOT EXPECTED. LOWS ON TUESDAY MORNING LOOK TO BE IN THE UPPER 30S WEST TO NEAR 50 EAST FA. HIGHS ON TUESDAY WILL RANGE FROM NEAR 50 IN THE FAR WEST TO THE LOW TO MID 60S FAR EAST FA. ON WEDNESDAY THE UPPER LOW CONTINUES TO MOVE NORTHEAST AND INTO EASTERN KANSAS AND OKLAHOMA. LOWS IN MORNING WILL BE IN THE UPPER 30S FAR WEST TO THE MID AND UPPER 40S EAST. HIGH TEMPERATURES WILL RANGE FROM THE MID 60S WEST TO AROUND 60 NORTHEAST. RAIN CHANCES DIMINISH FROM WEST TO EAST WITH THE UPPER LOW. TOTAL RAINFALL COULD RANGE FROM ONE QUARTER TO OVER ONE HALF INCH WITH THE HIGHEST IN THE SOUTHEASTERN FA FROM LARNED TO ASHLAND. FOR THURSDAY THE UPPER LEVEL SHORTWAVE RIDGING WILL MOVE INTO THE PLAINS WITH A WARM UP BACK INTO THE 70S. ANOTHER UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY NORTHEASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS FOR FRIDAY PUSHING ANOTHER COLD FRONT ACROSS KANSAS ON SATURDAY AS IT MOVES INTO THE NORTHERN HIGH PLAINS. LITTLE IF ANY RAINFALL IS EXPECTED. HIGHS ON FRIDAY LOOK TO BE IN THE MID TO UPPER 70S WITH SLIGHTLY COOLER TEMPS ON SATURDAY TO AROUND 70. OVERNIGHT LOWS WILL BE IN THE 40S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1201 AM CDT SUN APR 1 2012 TWO CONCERNS FOR THE 06Z TAFS. FOG AND WINDS. THE 01/02Z HRRR IS MOST AGGRESSIVE IN BRINGING DENSE FOG ACROSS SOUTH CENTRAL KANSAS BY MORNING. THIS MODEL WAS FAIRLY ACCURATE LAST NIGHT ALTHOUGH A LITTLE TOO LOW ON VIS. THE RUC ALSO SHOWS LOWERED VIS GENERALLY IN THE SAME AREA. DON`T HAVE ENOUGH CONFIDENCE FOR LIFR CIGS BUT HAVE LOWERED CIGS FROM VFR TO MVFR TO START OUT ON THE CONSERVATIVE SIDE SINCE THE HRRR OVERDID IT LAST NIGHT. SECOND CONCERN IS WINDS. HAVE INCREASED SW WINDS 20-25 KT WITH GUSTS TO 30-35 KT AS THE LEE SFC TROUGH STRENGTHENS TOMORROW AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 52 74 43 57 / 0 10 50 50 GCK 49 69 41 55 / 0 10 50 50 EHA 50 66 37 50 / 0 20 50 40 LBL 49 71 40 55 / 0 20 50 50 HYS 52 72 44 59 / 0 10 40 50 P28 57 82 49 63 / 0 30 50 50 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR KSZ030-043>045-061>064-074>078-084>087. && $$ UPDATE...RUTHI SYNOPSIS...RUTHI SHORT TERM...RUTHI LONG TERM....KRUSE AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
1135 PM CDT SAT MAR 31 2012 .AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU MAIN CONCERN REMAINS POTENTIAL FOR LOW STRATUS. LEE TROUGH WILL ALLOW LIGHT SOUTH-SOUTHEASTERLY WINDS TO CONTINUE OVERNIGHT WITH INCREASING BOUNDARY LAYER MOISTURE. THIS SHOULD RESULT IN LIFR-IFR STRATUS DEVELOPMENT OVER MUCH OF THE AREA DURING THE EARLY AM HOURS SUNDAY. THIS IS SUPPORTED IN THE NAM...GFS...RUC...AND 3KM HRRR MODELS. FORECAST CONFIDENCE IS ABOVE AVERAGE GIVEN THE LOW STRATUS OCCURRENCE IN CENTRAL/SOUTHWEST OK AND NORTH CENTRAL TEXAS SATURDAY MORNING. THE STRATUS LOOKS TO BURN OFF TOWARD MIDDAY SUNDAY. BETTER MIXING AND NEAR FULL SUNSHINE SUNDAY AFTERNOON SHOULD RESULT IN SOUTHERLY GUSTS ~25 KT MOST OF THE AREA. JMC && PREV DISCUSSION... /ISSUED 243 PM CDT SAT MAR 31 2012/ DISCUSSION... FORECAST CHALLENGES...LOW CLOUD TRENDS TONIGHT/SUNDAY MORNING AND THEN PRECIP CHANCES/TRENDS EARLY NEXT WEEK. TONIGHT-MONDAY LITTLE CHANGE TO THE FORECAST TO CLOSE OUT THE WEEKEND...WITH THE UNSEASONABLE WARMTH CLOSING IN ON SOME RECORDS. FOR THIS EVENING...SOUTHEAST KANSAS WILL REMAIN ON EDGE OF WEAKER CAP WHERE MODERATE INSTABILITY WILL BE PRESENT PRIOR TO DARK. HOWEVER LACK OF FOCUS/TRIGGER SHOULD PRECLUDE CONVECTION SO WILL KEEP FORECAST DRY. SOME PATCHY LIGHT FOG WITH PERHAPS BETTER CHANCE FOR SOME LOW CLOUDS TO DEVELOP AROUND DAWN ACROSS SOUTHERN PORTIONS OF THE AREA WITH CLOUDS LINGERING INTO MIDDAY FOR AREAS EAST OF THE TURNPIKE. OTHERWISE...INCREASING SOUTHERLY FLOW/BETTER MIXING INTO SUNDAY AFTERNOON SHOULD RESULT IN MORE SUNSHINE...WIND AND VERY WARM MAXS ACROSS THE ENTIRE...GENERALLY IN THE 85 TO 90F RANGE. THE APPROACHING UPPER TROF WILL MOVE ACROSS THE SOUTHWEST CONUS SUNDAY NIGHT...BECOMING A CLOSED LOW AS IT MOVES ACROSS THE SOUTHERN ROCKIES DURING MONDAY. THE INHERITED FORECAST SUPPORTS THE LATEST MODEL CONSENSUS IN SLOWING THE SURFACE FRONTAL PASSAGE AND PRECIP/CONVECTIVE CHANCES TO LATER IN THE DAY ON MONDAY. THIS WILL RESULT IN ONE MORE DAY OF UNSEASONABLY WARM TEMPERATURES ESPECIALLY FOR LOCATIONS ALONG AND EAST OF THE TURNPIKE. TUESDAY-WEDNESDAY A LITTLE BETTER MODEL CONTINUITY EXISTS WITH THE MOVEMENT OF THE CLOSED UPPER LOW ACROSS MID-AMERICA INTO MID-WEEK...WITH BEST CHANCE FOR SHOWERS/STORMS ON TUESDAY AND WEDNESDAY. THURSDAY-SATURDAY A COUPLE DAYS OF DRY WEATHER EXPECTED IN THE WAKE OF THE DEPARTING UPPER LOW FOR THURSDAY AND FRIDAY. MEANWHILE UPPER TROUGHING WILL DEVELOP ACROSS THE WESTERN CONUS WITH A SIGNIFICANT SHORTWAVE LIFTING NORTHEAST ACROSS THE NORTHERN PLAINS BY SATURDAY. WHILE CONFIDENCE IS MODEST AT BEST...WILL SHOW SMALL PRECIP/CONVECTIVE CHANCES ALONG THE ASSOCIATED SURFACE FRONT FRIDAY NIGHT/SATURDAY. DARMOFAL AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU FAIRLY QUIET AVIATION FORECAST FOR MOST OF THE PERIOD. FEW-SCT DIURNAL CUMULUS THIS AFTERNOON AT KICT-KHUT-KCNU WILL BURN OFF BY 00-02Z. OTHERWISE...DIURNAL COOLING IN CONCERT WITH INCREASING BOUNDARY LAYER MOISTURE MAY PROMOTE A 3-5 HOUR PERIOD OF IFR/LIFR CIGS FROM 10/11Z THROUGH 14/15Z. THE NAM MODEL MAY BE OVER-MOISTENING THE BOUNDARY LAYER AS IT OFTEN DOES...HENCE CONFIDENCE IS LOW ON THIS OCCURRING...SO ONLY HINTED AT IT IN THE 18Z TAFS. ADK FIRE WEATHER... DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS ON SUNDAY...THE GRASSLAND FIRE DANGER RISK IS EXPECTED TO BE ONLY SLIGHTLY ELEVATED DUE TO THE EARLY SPRING GREEN-UP. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 60 87 61 84 / 0 0 0 20 HUTCHINSON 59 89 59 81 / 0 0 0 20 NEWTON 60 87 62 82 / 0 0 0 20 ELDORADO 60 87 63 85 / 0 0 0 20 WINFIELD-KWLD 61 88 63 86 / 0 0 0 20 RUSSELL 59 91 56 75 / 0 0 0 20 GREAT BEND 58 90 55 77 / 0 0 0 20 SALINA 61 90 60 81 / 0 0 0 20 MCPHERSON 60 89 60 81 / 0 0 0 20 COFFEYVILLE 62 88 66 88 / 0 10 10 10 CHANUTE 61 88 65 87 / 0 10 10 10 IOLA 61 88 65 87 / 0 10 10 10 PARSONS-KPPF 61 88 65 88 / 0 10 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
527 PM EDT SUN APR 1 2012 .UPDATE... ISSUED AT 526 PM EDT SUN APR 1 2012 LAST OF THE MCS IS FINALLY DEPARTING OFF TO OUR SOUTHEAST...WITH SKIES QUICKLY CLEARING ACROSS THE AREA THIS EVENING. THIS SHOULD ALLOW FOR MOST PLACES TO REACH THEIR HIGH FOR THE DAY OVER THE NEXT HOUR OR TWO AS TEMPERATURES QUICKLY SHOOT UP WITH THE SUNSHINE. WITH STABLE AREA ENTRENCHED ACROSS EASTERN KENTUCKY STRETCHING NORTH INTO SOUTHERN OHIO...ANY DEVELOPING MCS WILL BE AT LEAST 3 TO 6 HOURS BEFORE IT IMPACTS OUR NECK OF THE WOODS. WITH THIS IN MIND...HAVE GONE AHEAD AND DELAYED THE BETTER PRECIPITATION CHANCES UNTIL AFTER 04Z (MIDNIGHT). THE HRRR SEEMS TO HAVE THE BEST TIMING AND HANDLING ON THE SITUATION WITH ALL OTHER MODELS TO AGGRESSIVE ON REDEVELOPING ACTIVITY IN THE STABLE BOUNDARY LAYER OVER THE NEXT FEW HOURS. NO INDICATION THIS WILL HAPPEN AS CLOUDS ARE FEW AND FAR BETWEEN. THUS...THE HRRR INDICATION OF LATER CONVECTION SEEMS LIKE THE WAY TO GO UNTIL SOMETHING SHOWS ME OTHERWISE. STILL GOING TO BE MAINLY A HAIL THREAT...ESPECIALLY GIVEN MOST OF THE ACTIVITY SHOULD BE ELEVATED. WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES AS EVENTS UNFOLD OVER THE NEXT 3 TO 6 HOURS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 359 PM EDT SUN APR 1 2012 THE LEFTOVER MCS IS FINALLY MAKING AN EXIT ACROSS THE AREA...WITH THE BACK EDGE LIKELY TO EXIT BETWEEN 4 AND 5 PM. HIGHS HAVE REALLY BEEN HAMPERED BY THE CLOUD COVER...BUT DO EXPECT A LATE IN THE DAY PUSH...WITH SOME LOW TO MID 70S FOUND WEST OF I-75...WHILE MOST OTHERS RANGE FROM THE MIDDLE 60S TO AROUND 70 DEGREES. THE MODELS CONTINUE TO PLAY UP ANOTHER THUNDERSTORM COMPLEX TO DEVELOP ACROSS THE UPPER OHIO BASIN LATER THIS EVENING IN RESPONSE TO A DIGGING SHORT WAVE TROUGH WHICH WILL NOSE IN FROM THE SAINT LAWRENCE RIVER VALLEY OVERNIGHT. THE MODEL TIMING OF THIS ACTIVITY IF IT DOES HAPPEN...SEEMS A BIT FAST...AS THERE IS NOTHING POPPING YET IN NORTHERN OHIO. WILL CONTINUE TO ALLOW FOR SOME GOOD CHANCE POPS LATER TONIGHT FOR THE NORTHEAST HALF OF THE AREA...SCALING BACK QUICKLY TO SLIGHT CHANCE TO THE SOUTHWEST. AS FOR THE SEVERE THREAT...HAVE EVEN LESS CONFIDENCE IN THIS...AS WE HAVE BEEN STABILIZED BY THE STORMS THAT TOOK PLACE THIS AFTERNOON. WILL HAVE TO WAIT AND SEE HOW THE ATMOSPHERE RECOVERS TONIGHT...WITH AT LEAST LIGHT SOUTHWEST WINDS ADVECTING SOME LOW LEVEL MOISTURE...WHICH MAY RECHARGE US SOMEWHAT. THIS COMPLEX...WILL HELP DRAG A BACKDOOR COOL FRONT THROUGH THE AREA DURING THE DAY TOMORROW. BESIDES SOME LEFTOVER CONVECTION IN THE MORNING...DO NOT EXPECT ANY RE-FIRING LATER IN THE DAY...WITH THE MODEL SOUNDINGS SHOWING SOME DECENT CAPPING. THE FRONT WILL THEN MOVE BACK TO THE NORTHEAST MONDAY NIGHT AS A WARM FRONT...PERHAPS KICKING OFF SOME ISOLATED CONVECTION AS THIS OCCURS. AS FOR TEMPERATURES...ABOVE NORMAL READINGS WILL CONTINUE...ALTHOUGH READINGS HAVE COME IN A BIT COOLER FOR MONDAY WITH A LITTLE MORE COOLER AND DRIER AIR INTRUSION...SO 70S WILL MOST LIKELY BE THE RULE FOR MOST LOCATIONS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 359 PM EDT SUN APR 1 2012 A RATHER COMPLEX AND SOMEWHAT PROGRESSIVE PATTERN IS ANTICIPATED DURING THE LONG TERM PERIOD. MOST OF THE TIME THE MAIN BAND OF WESTERLIES ARE EXPECTED TO RESIDE TO OUR WEST...NORTH OR NORTHEAST WITH UPPER LEVEL RIDGING POSSIBLY DOMINATING DURING TWO DISTINCT PERIODS...WITH THE HIGHEST CHANCE OF THIS LATE IN THE PERIOD. OVERALL...MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE PATTERN WITH SOME DIFFERENCES LATER IN THE PERIOD AND SOME TIMING DIFFERENCES FROM INDIVIDUAL MODEL RUN TO MODEL RUN. EARLY ON...A WARM FRONT WILL BE MOVING NORTHEAST AND POSSIBLY EXIT NORTHEAST OF THE AREA BY TUESDAY AFTERNOON OR EVENING. MODELS GENERALLY DEVELOP PRECIP ONLY OVER THE EASTERN HALF OF THE CWA EARLY IN THE PERIOD...WITH A POSSIBLE PERIOD OF SHORTWAVE RIDGING/DRY SLOTTING OCCURRING BEFORE A COLD FRONT APPROACHES LATE IN THE DAY OR TUE NIGHT. THIS COLD FRONT WILL DROP SLOWLY SOUTH FROM TUE NIGHT INTO WED...WITH THE MODEL CONSENSUS TAKING THE BOUNDARY SOUTH OF THE CWA BY WED EVENING. HOWEVER...THE BOUNDARY SHOULD THEN STALL FOR A TIME...THOUGH THE MODELS VARY IN HOW LONG DUE TO DIFFERENCES IN HANDLING AN UPPER LOW THAT WILL MEANDER SOUTH OF A NORTHERN PLAINS/NORTHERN GREAT LAKES RIDGE FROM THE SOUTHERN ROCKIES ACROSS THE PLAINS AND MS VALLEY AND ON INTO THE EASTERN CONUS...POSSIBLY ACROSS THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS AND THEN OFF THE EASTERN SEABOARD. THIS UPPER LOW IS EXPECTED TO FOLLOW THIS MEANDERING PATH FROM THE START OF THE PERIOD ON TUE THROUGH FRI. AS MENTIONED BY THE PREVIOUS FORECASTER....BUT FRI IT SHOULD FINALLY GET PICKED UP BY A TROUGH TO ITS NORTHEAST AND THIS SHOULD THEN TAKE IT OUT TO SEA. THEREAFTER...THE MODEL CONSENSUS IS FOR THE UPPER LEVEL RIDGE TO BUILD IN AND DOMINATE THAT LAST TWO TO TWO AND A HALF DAYS OF THE PERIOD. AS FOR POPS...WENT WITH SLIGHT CHANCE TO CHANCE POPS EARLY ON TUE WITH THE WARM FRONT AND THEN INCREASED POPS LATE ON TUE INTO TUE EVENING IN ADVANCE OF THE APPROACHING COLD FRONT AND SHORTWAVE THAT THE MODEL CONSENSUS TAKES ACROSS THE OH VALLEY REGION OR THE CWA ON TUE NIGHT. THE BOUNDARY SHOULD CONTINUE SLIPPING SOUTH ON WED AND CONTINUED CHANCE POPS DURING WED...BUT GRADUALLY LOWERED POPS IN THE NORTH FARTHER AWAY FROM THE BOUNDARY. A SFC LOW MAY DEVELOP ALONG THE BOUNDARY AS THE UPPER LOW APPROACHES AROUND MIDWEEK AND SLOW THE SOUTHWARD PROGRESS OF THE FRONT AND HOLD IN CHANCES FOR ISOLATED TO SCATTERED CONVECTION AS THE SFC LOW AND UPPER SYSTEM PROBABLY TRACK JUST TO OUR SOUTH ACROSS THE TN VALLEYS. ONCE THE UPPER SYSTEM TRACKS EAST...PRECIP CHANCES WILL DIMINISH LATE THU NIGHT OR FRI. FOR NOW THE END OF THE FORECAST IS EXPECTED TO BE DRY...WITH UPPER LEVEL RIDGING DOMINATING. WITH THIS RIDGE...OPTED TO FAVOR THE ECMWF RUNS. TEMPERATURES SHOULD BE WARMEST AND MOST ABOVE NORMAL ON TUESDAY AND THEN MORE MODEST DEPARTURES OF ABOUT 5 DEGREES ABOVE NORMAL AT THE END OF THE PERIOD. OVERNIGHT LOWS SHOULD AVERAGE AT LEAST 5 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 158 PM EDT SUN APR 1 2012 A COMPLEX OF SHOWERS AND THUNDERSTORMS WILL GRADUALLY WEAKEN AND EXIT OFF TO THE SOUTHEAST IN THE NEXT FEW HOURS...ALLOWING FOR AT LEAST TEMPORARILY IMPROVING CONDITIONS AT SME AND LOZ. VFR CONDITIONS WILL RETURN...ALTHOUGH THERE WILL BE A RENEWED THREAT OF CONVECTION THIS EVENING AND INTO THE OVERNIGHT HOURS TONIGHT...HOWEVER WILL ONLY MAINTAIN THE VCTS WORDING FOR NOW...AS CONFIDENCE REMAINS LOW IN WHERE AND WHEN THE CONVECTION WILL OCCUR. RIGHT NOW...IT DOES APPEAR THAT THE BETTER THREAT WILL BE ALONG AND EAST OF A LINE FROM MOREHEAD...TO JACKSON...TO HARLAN. .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...GEOGERIAN LONG TERM....JP AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
935 PM CDT MON APR 2 2012 .UPDATE...CONVECTION IS BEING RATHER STUBBORN. OLD OUTFLOW BNDRY CONTINUES TO WORK EAST ACROSS COASTAL MS BUT HAS BASICALLY STALLED OVER COASTAL LA. IN FACT WHERE THE BNDRY IS ANCHORED(OVER TERREBONNE...ST MARY...ASSUMPTION...AND ST MARTING PARISHES) IT IS INTERACTING WITH A COOL POCKET NOTED BY THE RUC. THE RUC IS THE ONLY MODEL EVEN NOTICING IT RIGHT NOW AS ALL OF THE OTHER HIRES SHORT RANGE MDLS(12-36 HRS) ARENT EVEN HANDLING THE CURRENT CONVECTION. THE RUC IS SHOWING THIS COOL POCKET MOVING TO THE NORTH AND BECOMING ELONGATED FROM NNW-SSE OVER THE WRN QUARTER OF OUR CWA. WITH THAT I HAVE INCREASED POPS GREATLY FOR OUR SW AND WEST FOR OVERNIGHT. THERE IS THE POSSIBILITY THAT THERE COULD BE SOME RATHER HEAVY RAINFALL SOMEWHERE OVER ASSUMPTION...NRN TERREBONNE...NWRN LAFOURCHE...ST JAMES...AND MAYBE INTO IBERVILLE AND ASCENSION PARISHES OVERNIGHT. CONVECTION SOUTH OF THE NO METRO SHOULD CONTINUE TO SLOWLY DRIFT SOUTH AND WEAKEN OVERNIGHT. GRIDS AND ZONES ARE OUT. /CAB/ && .PRELIMINARY POINT TEMPS/POPS... MCB 66 85 67 83 / 20 40 40 50 BTR 68 85 71 83 / 40 40 40 50 ASD 67 85 69 82 / 20 30 40 50 MSY 71 85 72 82 / 30 30 40 50 GPT 70 81 72 80 / 20 30 40 40 PQL 67 82 71 80 / 20 30 20 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$ CAB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
412 PM EDT SUN APR 1 2012 .SYNOPSIS... A COLD FRONT MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY TONIGHT WILL SPAWN SHOWERS AND SCATTERED EVENING THUNDERSTORMS. CANADIAN HIGH PRESSURE WILL THEN PROVIDE DRY SEASONABLE WEATHER MONDAY. A LOW PRESSURE SYSTEM, COMING SOUTHEAST FROM MONTANA, WILL BRING SHOWERS AND SCATTERED THUNDERSTORMS TUESDAY AFTERNOON AND NIGHT. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... BLEND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOW A SLOWER DEVELOPMENT OF THE COLD FRONTAL SHOWER BAND ACROSS THE I-80 CORRIDOR. THIS MAY BE DUE TO SURFACE LAYER DRYNESS WHICH WOULD INHIBIT INSTABILITY. THIS WOULD LIKEWISE INHIBIT THUNDERSTORM DEVELOPMENT THIS EVENING, BUT AT THIS JUNCTURE HAVE NOT OMITTED MENTION OF SCATTERED EVENING THUNDERSTORMS. CONCUR WITH RECENT HRRR THAT ANY REMAINING SHOWERS WILL HAVE EXITED SOUTH INTO CENTRAL WEST VIRGINIA BY LATE TONIGHT. FORECASTED TEMPERATURES TONIGHT USING BLEND OF HRRR, LAMP, AND NAM MODEL OUTPUT WHICH YIELDED VALUES EITHER NEAR OR SLIGHTLY WARMER THAN NORMAL. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... BLEND OF RECENT SREF MODEL OUTPUT SHOWS CANADIAN HIGH PRESSURE PROVIDING SUBSIDENCE AND DRYING MONDAY. HENCE EXPECT SUNSHINE TO BE PREVALENT. LOW PRESSURE SYSTEM, COMING SOUTHEAST FROM MONTANA, WILL NEXT SPREAD CLOUDS EASTWARD ACROSS THE UPPER OHIO VALLEY STARTING LATE MONDAY NIGHT. HAVE MAINTAINED A FORECAST OF A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND NIGHT WITH THE EASTWARD PASSAGE OF THE LOW PRESSURE CENTER ACROSS THE UPPER OHIO VALLEY. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS WEDNESDAY. FORECASTED TEMPERATURES, USING CONSENSUS OF SREF, GFS AND NAM GUIDANCE, TO BE NEAR NORMAL MONDAY, 7 TO 10 DEGREES WARMER THAN NORMAL TUESDAY, AND NO MORE LIKE 3 TO 5 DEGREES WARMER THAN NORMAL DAYTIME WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... DRY WEATHER SHOULD PREVAIL ACROSS THE UPPER OHIO VALLEY REGION INTO THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE SLIDES SOUTHEAST ACROSS THE GREAT LAKES. A SLOW MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD FROM THE LOWER MS VALLEY TO OFF SOUTHEAST COAST LATE IN THE WEEK. THE BULK OF ASSOCIATED MOISTURE IS PROGGED TO REMAIN SOUTH OF THE FORECAST AREA. HPC GUIDANCE SHOWS THE NEXT COLD FRONT APPROACHING FROM THE WEST WITH A CHANCE OF SHOWERS LATE SUNDAY. TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH FRIDAY...THEN WARMING TO AROUND 10 DEGREES ABOVE NORMAL DURING THE WEEKEND. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... A SHORTWAVE TROUGH WILL CONTINUE TO PLUNGE SOUTHEAST OFF THE MID ATLANTIC COAST EARLY TONIGHT. THE ASSOCIATED WEAK SURFACE REFLECTION AND COLD FRONT WILL MOVE ACROSS THE TERMINALS EARLY TONIGHT. SCATTERED SHOWERS WITH BRIEF MVFR RESTRICTIONS ARE EXPECTED AS THE SYSTEM MOVES THROUGH...FOLLOWED BY GENERALLY MVFR CEILINGS BEHIND THE FRONT OVERNIGHT. CONDITIONS ARE FORECAST TO IMPROVE TO VFR BY LATE MONDAY MORNING AS A SURFACE RIDGE BUILDS IN FROM THE NORTH. SOUTHWEST SURFACE WINDS WILL BECOME NORTHWEST AROUND 10KT BEHIND THE FRONTAL BOUNDARY TONIGHT. OUTLOOK...MONDAY NIGHT THROUGH FRIDAY... ANOTHER SHORTWAVE TROUGH AND COLD FRONT WILL BRING SCATTERED SHOWERS AND THE POTENTIAL FOR RESTRICTIONS LATE TUESDAY INTO TUESDAY NIGHT. A RETURN TO PREDOMINATELY VFR WEATHER IS EXPECTED WEDNESDAY THROUGH FRIDAY AS HIGH PRESSURE SLIDES ACROSS THE REGION. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
307 PM EDT SUN APR 1 2012 .SYNOPSIS... A COLD FRONT WILL PASS THROUGH THE REGION TONIGHT BEFORE HIGH PRESSURE BUILDS OVERHEAD MONDAY THROUGH MONDAY NIGHT. HIGH PRESSURE WILL MOVE OFF THE COAST TUESDAY AND ANOTHER COLD FRONT WILL IMPACT THE REGION WEDNESDAY. HIGH PRESSURE IS EXPECTED TO BUILD OVERHEAD LATE IN THE WEEK. && .NEAR TERM /THROUGH MONDAY/... CU/STRATOCU FIELD EAST OF THE BLUE RIDGE WAS BREAKING UP/SCATTERING THIS AFTERNOON. THIS WILL ALLOW FOR PARTIAL SUNSHINE THIS AFTERNOON BEFORE THE NEXT BATCH OF CLOUDS ROLLS IN BY EARLY EVENING. HAVE A FEW SHOWERS MAKING THEIR WAY INTO CENTRAL PENNSYLVANIA AT 2 PM. SOUTHERN EDGE MAY CLIP MARYLAND COUNTIES ALONG THE MASON DIXON LINE THIS AFTERNOON BUT PER HRRR GUIDANCE THE BULK OF THESE STAY TO THE NORTH/NORTHEAST OF THE CWA THIS AFTERNOON. HOWEVER...AS LOW PRESSURE AND A COLD FRONT APPROACH FROM THE WEST...EXPECT A NEW AREA OF SHOWERS TO DEVELOP AND PRESS SOUTH THROUGH THE EVENING/OVERNIGHT HOURS. WRF-ARW SEEMS A LITTLE ON THE FAST SIDE...AND PREFER THE TIMING/EVOLUTION INDICATED BY THE HRRR WHICH HAS GENERAL SUPPORT FROM THE NAM/GFS/SREFS. HAVE INCREASED POPS TO CATEGORICAL ACROSS THE NORTHERN HALF OF THE CWA...WITH HIGH CHANCE TO LIKELY ACROSS THE SOUTHERN REACHES OF THE CWA. GIVEN TIME OF DAY/RELATIVE LACK OF INSTABILITY...HAVE LOW CONFIDENCE IN THUNDERSTORMS. HAVE ALLOWED FOR ISOLATED EVENING THUNDER ACROSS THE WEST WHERE SUNSHINE THIS AFTERNOON HAS BEEN LONGER AND WHERE THERE MAY BE A LITTLE INSTABILITY. FURTHER EAST...ONLY P-TYPE INCLUDED IS SHOWERS. LOW PRESSURE SHOULD BE OFF THE COAST AND THE COLD FRONT SOUTH OF THE AREA BY AROUND 10Z MONDAY. SKIES WILL CLEAR OUT BEHIND THE FRONT...PAVING THE WAY FOR PLENTY OF SUNSHINE. HOWEVER WITH SUNSHINE MIXING WILL BE DECENT AND EXPECT WIND GUSTS AOA 25 MPH. LEANED TOWARD THE WARMER SET OF MOS FOR MAX T ON MONDAY...WHICH RANGES FROM LOWER 60S ACROSS NORTHEAST MARYLAND TO UPPER 60S TOWARD THE CENTRAL VA FOOTHILLS. && .SHORT TERM /MONDAY NIGHT/... SURFACE HIGH PRESSURE WILL BUILD OVERHEAD MONDAY NIGHT...CAUSING DRY AND SEASONABLY CHILLY CONDITIONS. LIGHT WINDS...DRY AIR AND MAINLY CLEAR SKIES WILL PROVIDE A GOOD SETUP FOR RADIATIONAL COOLING. MIN TEMPS WILL RANGE FROM THE LOWER AND MIDDLE 30S ACROSS NORTHERN MARYLAND INTO EASTERN WEST VIRGINIA AND NORTHERN VIRGINIA...TO THE LOWER AND MIDDLE 40S IN DOWNTOWN WASHINGTON/BALTIMORE AND LOWER SOUTHERN MARYLAND. AREAS OF FROST ARE POSSIBLE ACROSS PORTIONS OF THE NORTHERN MARYLAND...EASTERN WEST VIRGINIA AND NORTHERN VIRGINIA LATE MONDAY NIGHT. A FROST ADVISORY MAY BE NEEDED. && .LONG TERM /TUESDAY THROUGH SUNDAY/... HIGH PRESSURE WILL MOVE OFF THE COAST TUESDAY AND A RETURN FLOW FROM THE SOUTH WILL USHER IN MILD CONDITIONS. MAX TEMPS WILL RANGE FROM THE MID 60S ACROSS NORTHEASTERN MARYLAND TO THE MIDDLE 70S ACROSS CENTRAL VIRGINIA. WARM AND MOIST AIR WILL LEAD TO LIMITED INSTABILITY ACROSS THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY. SCATTERED SHOWERS/T-STORMS ARE POSSIBLE ACROSS THESE AREAS LATE IN THE DAY. A COLD FRONT WILL PASS THROUGH THE AREA TUESDAY NIGHT INTO WEDNESDAY. A FEW SHOWERS ARE POSSIBLE ALONG AND AHEAD OF THE COLD FRONT. THE BEST CHANCE FOR PRECIPITATION WILL BE ACROSS CENTRAL VIRGINIA AND LOWER SOUTHERN MARYLAND WEDNESDAY AFTERNOON. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM WEDNESDAY NIGHT THROUGH THURSDAY...BRINGING DRY AND SEASONABLE CONDITIONS. A STORM SYSTEM WILL PASS BY TO OUR SOUTH THURSDAY NIGHT AND FRIDAY. AS OF NOW IT APPEARS THAT IT WILL BE TOO FAR TO OUR SOUTH TO HAVE A SIGNIFICANT IMPACT ON OUR WEATHER...BUT THE CERTAINTY REMAINS LOW THIS FAR OUT. HIGH PRESSURE WILL RETURN NEXT WEEKEND BEHIND THIS SYSTEM. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... MAINLY VFR CU/STRATOCU WILL CONTINUE TO BREAK UP THIS AFTERNOON BEFORE CLOUDS ROLL BACK IN THIS EVENING. LOW PRESSURE/FRONT WILL BRING THE LIKELIHOOD OF SHOWERS TONIGHT DURING A SEVERAL HOUR WINDOW. TIMING FROM HRRR MODEL LOOKS REASONABLE. INCLUDED MVFR RESTRICTIONS IN SHOWERS. WINDS SHIFT TO THE NORTHWEST OVERNIGHT AND BECOME GUSTY. GUSTS AOA 25 KT ARE EXPECTED ON MONDAY BEFORE DIMINISHING LATE. HIGH PRESSURE WILL BUILD OVER THE TERMINALS MONDAY NIGHT BEFORE MOVING OFF THE COAST TUESDAY. VFR CONDITIONS ARE EXPECTED DURING THIS TIME. A COLD FRONT WILL BRING THE CHANCE FOR SHOWERS TUESDAY NIGHT AND WEDNESDAY. THE TIMING OF THE FRONTAL PASSAGE REMAINS UNCERTAIN THIS FAR OUT...BUT IF THE FRONTAL PASSAGE IS SLOW ENOUGH THEN THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON. HIGH PRESSURE WILL RETURN FOR LATE IN THE WEEK. && .MARINE... WILL HAVE TO WATCH SOUTHERLY FLOW THIS EVENING. WINDS HAVE REMAINED IN CHECK /AROUND 10 KT/ SO FAR THIS AFTERNOON...BUT CHANNELLING THIS EVENING COULD BRING WINDS CLOSE TO SCA THRESHOLDS UP THE BAY. HIGHER CONFIDENCE EXISTS IN SCA CONDITIONS WITH A FROPA/WIND SHIFT TO THE NORTHWEST TONIGHT AND CONTINUING INTO MONDAY. HIGH PRESSURE WILL BUILD OVER THE WATERS MONDAY NIGHT BEFORE MOVING OFF THE COAST TUESDAY. NORTHWEST WINDS AHEAD OF THE HIGH WILL GUST PAST SCA CRITERIA CROSS THE MIDDLE PORTION OF THE BAY AND LOWER TIDAL POTOMAC RIVER. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THESE AREAS. WINDS WILL DIMINISH TOWARD TUESDAY MORNING AS HIGH PRESSURE BUILDS OVERHEAD. A RETURN FLOW WILL DEVELOP AROUND THE DEPARTING HIGH TUESDAY. A COLD FRONT WILL PASS THROUGH THE WATERS LATE TUESDAY NIGHT INTO WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS DURING THIS TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT LATE IN THE WEEK. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS THURSDAY. && .TIDES/COASTAL FLOODING... WILL CONTINUE COASTAL FLOOD ADVISORY THROUGH HIGH TIDE TIMES IN COUNTIES ADJACENT TO THE UPPER BAY THIS AFTERNOON. AT 2 PM...ANNAPOLIS REMAINED ABOUT 2.5 FT MLWW BUT WILL BE ON THE WAY DOWN OVER THE NEXT COUPLE OF HOURS. BIG QUESTION IS WHAT OCCURS ON THE OVERNIGHT HIGH TIDE CYCLE. THERE IS THE CHANCE THAT ANOMALIES MAY REMAIN STEADY AND IF THAT IS THE CASE THE COASTAL FLOOD ADVISORY MAY NEED TO BE EXTENDED FOR THE NEXT HIGH TIDE CYCLE BEFORE NORTHWEST WINDS DRIVE WATER OUT OF THE BAY OVERNIGHT INTO MONDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...COASTAL FLOOD ADVISORY UNTIL 7 PM EDT THIS EVENING FOR MDZ007- 011-014-018. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 8 PM EDT MONDAY FOR ANZ530- 531-535-536-538-539. SMALL CRAFT ADVISORY FROM 2 AM MONDAY TO 2 AM EDT TUESDAY FOR ANZ532>534-537-540>543. && $$ SYNOPSIS...BPP/BJL NEAR TERM...BPP SHORT TERM...BJL LONG TERM...BJL AVIATION...BPP/BJL MARINE...BPP/BJL TIDES/COASTAL FLOODING...BPP
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1149 AM EDT SUN APR 1 2012 .SYNOPSIS... A COLD FRONT MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY THIS AFTERNOON AND EVENING WILL PROVIDE SHOWERS WITH SCATTERED THUNDERSTORMS ACROSS OHIO AND WEST VIRGINIA. CANADIAN HIGH PRESSURE WILL PROVIDE A DRY BREAK MONDAY BEFORE THE FRONT RETURNS AS A WARM FRONT WITH SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... RECENT SATELLITE DATA SHOWS CLOUDS HAVE DECREASED FOR THE MIDDAY, BUT BLEND OF RECENT HRRR AND NAM MODEL OUTPUT SHOW CLOUDS WILL INCREASE THIS AFTERNOON AND SHOWERS WILL START TO DEVELOP NEAR A SOUTHEAST MOVING COLD FRONT ACROSS NORTHWEST PENNSYLVANIA AND A NEAR STATIONARY WARM FRONT POSITIONED JUST SOUTH OF THE I-70. RECENT HRRR AND NAM MODEL OUTPUT THEN SHOW THE COLD FRONTAL BAND OF SHOWERS, WITH SCATTERED THUNDERSTORMS OVER OHIO AND NORTHERN WEST VIRGINIA, WILL CONTINUE TO MOVE SOUTHEASTWARD ACROSS THE UPPER OHIO VALLEY INTO EVENING, EXITING THE REGION BY ABOUT MIDNIGHT. CLOUDS WILL LIKEWISE DECREASE, NORTH TO SOUTH, AS CANADIAN HIGH PRESSURE PROVIDES SUBSIDENCE AND SURFACE LAYER DRYING. ADJUSTED TEMPERATURE FORECAST TOWARD SLIGHTLY COOLER VALUES USING BLEND OF HRRR, SREF, GFS, AND NAM MODEL OUTPUT. && .SHORT TERM /MONDAY THROUGH TUESDAY/... MONDAY WEATHER LOOKS DRY WITH MODELS IN AGREEMENT IN DEPICTIONS OF DRY SURFACE HIGH SLIDING OVER THE UPPER OHIO REGION AS RIDGE ALOFT AMPLIFIES OVER THE WESTERN GREAT LAKES. COOL NORTH TO NORTHEAST WIND SHOULD LIMIT TEMPERATURE RECOVERY DESPITE SUNSHINE. READINGS WERE FORECAST USING SREF WITH AN APPROXIMATE 10 DEGREE SPREAD FM NR DUBOIS TO ZANESVILLE AS REGION WL BE UNDER BAROCLINIC ZONE TO THE EAST OF THE RIDGE AXIS. THAT BAROCLINIC ZONE/FRONTAL BOUNDARY WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT LATE MONDAY NIGHT AND TUESDAY AS SHORTWAVE CROSSES THE LAKES AND ERODES THE RIDGE. TEMPERATURES WL MODERATE IN THE WARM ADVECTION ON THE VAN OF THAT SYSTEM. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... IN GENERAL...NORTHWEST FLOW PATTERN ACROSS THE GREAT LAKES REGION IS PROJECTED TO CONTINUE FOR THE SECOND HALF OF THE WEEK. TEMPERATURES WL THUS BE WITHIN A FEW DEGREES OF THE SEASONAL AVERAGES. HAVE PERSISTED WITH SUB CLIMO POPS...BUT CHANGES SHOULD BE ANTICIPATED AS EVENTUAL WEATHER WL BE SHORTWAVE DEPENDENT. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... LAST OF THE MVFR STRATOCUMULUS CEILINGS SHOULD EITHER DISSIPATE OR LIFT TO VFR LEVELS BY 17Z. SOUTHEASTWARD MOVING COLD FRONTAL BAND OF MVFR SHOWERS WILL MOVE FROM THE I-80 CORRIDOR AROUND 20Z TO SOUTH OF THE I-70 CORRIDOR BY 00Z. RAIN SHOWERS WILL END FROM NORTH TO SOUTH AS THE FRONT EXITS, BUT LOWER CLOUDS WILL MOVE BACK IN WITH THE CAA. EXPECT GENERAL MVFR RESTRICTIONS AT ALL PORTS, WITH THE EXCEPTION OF ZZV FOR THE LATE EVENING HOURS, THEN POSSIBLE IFR RESTRICTIONS BY LATE SUNDAY NIGHT, EARLY MONDAY MORNING. OUTLOOK...MONDAY THROUGH WEDNESDAY...MONDAY WILL BEGIN WITH IFR/MVFR CLOUDS WITH THE EXCEPTION OF ZZV THEN A RAPID IMPROVEMENT TO VFR CONDITIONS AS HIGH PRESSURE BUILDS IN. THE NEXT LOW PRESSURE SYSTEM WILL BRING RESTRICTIONS LATE TUESDAY AFT AND TUESDAY NIGHT, WITH A RETURN TO VFR LATER WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
347 PM EDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 347 PM EDT SUN APR 1 2012 A STALLED FRONT WILL BRING SOME ISOLATED SHOWERS THIS EVENING. FAIR WEATHER IS EXPECTED FOR MONDAY THEN SOME SHOWERS AND AN ISOLATED THUNDERSTORM IS POSSIBLE MONDAY NIGHT AS LOW PRESSURE MOVES JUST SOUTH OF LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY THROUGH THE END OF THE WEEK WITH FAIR WEATHER AND FROSTY OVERNIGHT LOWS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 347 PM EDT SUN APR 1 2012 BANDS OF LIGHT OVERRUNNING SHOWERS ACROSS NORTHERN WISCONSIN WILL BE MOVING INTO THE FORECAST AREA THROUGH THE EVENING. MOST OF THESE SHOWERS ARE LIGHT AND SOME OF THE RAIN IS EVAPORATING BEFORE REACHING THE GROUND...SO SLIGHT CHANCE POPS AND ISOLATED WORDING SHOULD COVER IT. HRRR RUC HAS HAD A GOOD HANDLE ON THIS THROUGH THE DAY...SO FOLLOWED IT FOR POPS OVERNIGHT. AFTER A BREAK IN THE PRECIP...MORE SHOWERS SHOULD MOVE IN MONDAY EVENING AS SFC LOW APPROACHES. SOME ELEVATED INSTABILITY EXISTS BUT IT IS MARGINAL...SO WENT WITH ISOLATED THUNDER CHANCES. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 335 PM EDT SUN APR 1 2012 LOW PRESSURE IS EXPECTED TO BE SLIDING EAST OVER THE LOWER GREAT LAKES ON TUESDAY. IT STILL LOOKS LIKE SOME POTENTIAL FOR STRONG STORMS WILL HAIL...ESPECIALLY EARLY IN THE DAY...AND MAINLY ALONG AND SOUTH OF I-96. SYSTEM LOOKS A BIT SLOWER NOW...SO HAVE POPS GOING THROUGHOUT THE DAY. VERY DRY AIR FOLLOWS THE SYSTEM BY TUESDAY EVENING WITH CLEARING SKIES. COULD BE THE THREAT OF FROST BY WEDNESDAY MORNING...BUT THIS SHOULD BE PATCHY OVER INLAND AREAS AS THE PRESSURE GRADIENT SHOULD STILL CAUSE SOME MIXING THROUGH THE NIGHT. LOOKS LIKE THE BEST CHANCE OF FROST WILL COME LATE WEDNESDAY NIGHT AND LATE THURSDAY NIGHT AS THE SURFACE RIDGE AXIS WILL BE NEARBY GIVING US LIGHTER WINDS AND SINKING TEMPS TO THE LOW TO MID 30S IN MANY LOCATIONS. NEXT CHANCE OF RAIN SHOULD NOT COME UNTIL SATURDAY NIGHT INTO SUNDAY. STILL SOME UNCERTAINTY IN THIS GIVEN THE STRONG RIDGE TO OUR EAST. BUT GENERAL GUIDANCE CONSCIENCE SHOWS A FRONT COMING THROUGH ON SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 256 PM EDT SUN APR 1 2012 MVFR IN HAZE AND SOME CEILINGS BELOW 2000 FEET SHOULD BE GOING TO VFR BY LATE AFTERNOON. SOME LIGHT SHOWERS MOVING IN BY 00Z CONTINUING THIS EVENING BUT THESE SHOULD BE ISOLATED AND NOT AFFECT THE GENERALLY VFR CONDITIONS OVERNIGHT. && .MARINE... ISSUED AT 256 PM EDT SUN APR 1 2012 WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK. && .HYDROLOGY... ISSUED AT 256 PM EDT SUN APR 1 2012 NO HYDRO ISSUES. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...OSTUNO SHORT TERM...OSTUNO LONG TERM....JK AVIATION...OSTUNO HYDROLOGY...OSTUNO MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
336 PM EDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 1256 PM EDT SUN APR 1 2012 A FEW SHOWERS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MONDAY NIGHT AND TUESDAY. THEN HIGH PRESSURE WILL BRING FAIR WEATHER WITH FROSTY OVERNIGHT LOWS FOR THE REST OF THE WEEK. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 1256 PM EDT SUN APR 1 2012 ADDED SLIGHT CHANCE POPS FOR LATE AFTERNOON INTO THIS EVENING. OVERRUNNING SHOWERS CURRENTLY OVER NORTHERN WISCONSIN WILL BE SINKING SOUTHEAST INTO LOWER MICHIGAN. HRRR RUC SEEMS TO HAVE A HANDLE ON THESE AND THE TIMING WAS FOLLOWED IN THE GRIDS. ALSO TWEAKED TEMPS DOWN A FEW DEGREES THIS AFTERNOON BASED ON CURRENT OBS AND STUBBORN LOW LEVEL STRATUS THIS IS SLOW TO MIX OUT GIVEN CURRENT STRONG INVERSION BELOW 700 MB. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 335 PM EDT SUN APR 1 2012 LOW PRESSURE IS EXPECTED TO BE SLIDING EAST OVER THE LOWER GREAT LAKES ON TUESDAY. IT STILL LOOKS LIKE SOME POTENTIAL FOR STRONG STORMS WILL HAIL...ESPECIALLY EARLY IN THE DAY...AND MAINLY ALONG AND SOUTH OF I-96. SYSTEM LOOKS A BIT SLOWER NOW...SO HAVE POPS GOING THROUGHOUT THE DAY. VERY DRY AIR FOLLOWS THE SYSTEM BY TUESDAY EVENING WITH CLEARING SKIES. COULD BE THE THREAT OF FROST BY WEDNESDAY MORNING...BUT THIS SHOULD BE PATCHY OVER INLAND AREAS AS THE PRESSURE GRADIENT SHOULD STILL CAUSE SOME MIXING THROUGH THE NIGHT. LOOKS LIKE THE BEST CHANCE OF FROST WILL COME LATE WEDNESDAY NIGHT AND LATE THURSDAY NIGHT AS THE SURFACE RIDGE AXIS WILL BE NEARBY GIVING US LIGHTER WINDS AND SINKING TEMPS TO THE LOW TO MID 30S IN MANY LOCATIONS. NEXT CHANCE OF RAIN SHOULD NOT COME UNTIL SATURDAY NIGHT INTO SUNDAY. STILL SOME UNCERTAINTY IN THIS GIVEN THE STRONG RIDGE TO OUR EAST. BUT GENERAL GUIDANCE CONSCIENCE SHOWS A FRONT COMING THROUGH ON SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 256 PM EDT SUN APR 1 2012 MVFR IN HAZE AND SOME CEILINGS BELOW 2000 FEET SHOULD BE GOING TO VFR BY LATE AFTERNOON. SOME LIGHT SHOWERS MOVING IN BY 00Z CONTINUING THIS EVENING BUT THESE SHOULD BE ISOLATED AND NOT AFFECT THE GENERALLY VFR CONDITIONS OVERNIGHT. && .MARINE... ISSUED AT 256 PM EDT SUN APR 1 2012 WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK. && .HYDROLOGY... ISSUED AT 256 PM EDT SUN APR 1 2012 NO HYDRO ISSUES. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...OSTUNO SHORT TERM...OSTUNO LONG TERM....JK AVIATION...OSTUNO HYDROLOGY...OSTUNO MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
256 PM EDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 1256 PM EDT SUN APR 1 2012 A FEW SHOWERS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MONDAY NIGHT AND TUESDAY. THEN HIGH PRESSURE WILL BRING FAIR WEATHER WITH FORSTY OVERNIGHT LOWS FOR THE REST OF THE WEEK. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 1256 PM EDT SUN APR 1 2012 ADDED SLIGHT CHANCE POPS FOR LATE AFTERNOON INTO THIS EVENING. OVERRUNNING SHOWERS CURRENTLY OVER NORTHERN WISCONSIN WILL BE SINKING SOUTHEAST INTO LOWER MICHIGAN. HRRR RUC SEEMS TO HAVE A HANDLE ON THESE AND THE TIMING WAS FOLLOWED IN THE GRIDS. ALSO TWEAKED TEMPS DOWN A FEW DEGREES THIS AFTERNOON BASED ON CURRENT OBS AND STUBBORN LOW LEVEL STRATUS THIS IS SLOW TO MIX OUT GIVEN CURRENT STRONG INVERSION BELOW 700 MB. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 400 AM EDT SUN APR 1 2012 MONDAY NIGHT AND EARLY TUESDAY COULD BE ACTIVE WITH MCS ACTIVITY AS H8 THETA-E RIDGE AND LOW LEVEL JET ARE PROGGED TO BE IMPACTING THE REGION. ELEVATED INSTABILITY LOOKS PRETTY IMPRESSIVE WITH H8 LI/S AROUND -6C. DEEP LAYER SHEAR IS IN EXCESS OF 35-40 KTS AND SUSPECT A LARGE HAIL THREAT WILL EXIST WITH ANY TSTM CELLS/CLUSTERS TRACKING SOUTHEAST THROUGH THE AREA. THE NAM/GFS SHOW THE SFC FRONT/TROUGH EXITING THE REGION BY 18Z TUESDAY BUT THE EURO IS SLOWER AND SUGGESTS A CONVECTIVE THREAT LINGERING ALL DAY TUESDAY. WEDNESDAY THROUGH SATURDAY IS DOMINATED BY A LARGE/DRY AREA OF HIGH PRESSURE. THIS FEATURE WILL BRING A THREAT OF FROST EACH NIGHT... WITH SUNNY/PLEASANT CONDITIONS AND HIGHS IN THE 50S/60S EXPECTED FOR THE DAYS. DIURNAL TEMP SWINGS SHOULD BE RATHER LARGE DUE TO THE DRY AIR MASS AND MAINLY CLEAR SKIES. CONSIDERING THAT THE LOW LEVEL FLOW SHOULD BE PREDOMINATELY NORTHEASTERLY... WOULD EXPECT THE WARMEST HIGH TEMPERATURES TO BE IN THE WRN HALF OF THE CWFA DURING THE MID TO LATE WEEK PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 256 PM EDT SUN APR 1 2012 MVFR IN HAZE AND SOME CEILINGS BELOW 2000 FEET SHOULD BE GOING TO VFR BY LATE AFTERNOON. SOME LIGHT SHOWERS MOVING IN BY 00Z CONTINUING THIS EVENING BUT THESE SHOULD BE ISOLATED AND NOT AFFECT THE GENERALLY VFR CONDITIONS OVERNIGHT. && .MARINE... ISSUED AT 256 PMEDT SUN APR 1 2012 WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK. && .HYDROLOGY... ISSUED AT 256 PM EDT SUN APR 1 2012 NO HYDRO ISSUES. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...OSTUNO SHORT TERM...OSTUNO LONG TERM....MEADE AVIATION...OSTUNO HYDROLOGY...OSTUNO MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1257 PM EDT SUN APR 1 2012 .SYNOPSIS... ISSUED AT 1256 PM EDT SUN APR 1 2012 A FEW SHOWERS ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MONDAY NIGHT AND TUESDAY. THEN HIGH PRESSURE WILL BRING FAIR WEATHER WITH FORSTY OVERNIGHT LOWS FOR THE REST OF THE WEEK. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 1256 PM EDT SUN APR 1 2012 ADDED SLIGHT CHANCE POPS FOR LATE AFTERNOON INTO THIS EVENING. OVERRUNNING SHOWERS CURRENTLY OVER NORTHERN WISCONSIN WILL BE SINKING SOUTHEAST INTO LOWER MICHIGAN. HRRR RUC SEEMS TO HAVE A HANDLE ON THESE AND THE TIMING WAS FOLLOWED IN THE GRIDS. ALSO TWEAKED TEMPS DOWN A FEW DEGREES THIS AFTERNOON BASED ON CURRENT OBS AND STUBBORN LOW LEVEL STRATUS THIS IS SLOW TO MIX OUT GIVEN CURRENT STRONG INVERSION BELOW 700 MB. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 400 AM EDT SUN APR 1 2012 MONDAY NIGHT AND EARLY TUESDAY COULD BE ACTIVE WITH MCS ACTIVITY AS H8 THETA-E RIDGE AND LOW LEVEL JET ARE PROGGED TO BE IMPACTING THE REGION. ELEVATED INSTABILITY LOOKS PRETTY IMPRESSIVE WITH H8 LI/S AROUND -6C. DEEP LAYER SHEAR IS IN EXCESS OF 35-40 KTS AND SUSPECT A LARGE HAIL THREAT WILL EXIST WITH ANY TSTM CELLS/CLUSTERS TRACKING SOUTHEAST THROUGH THE AREA. THE NAM/GFS SHOW THE SFC FRONT/TROUGH EXITING THE REGION BY 18Z TUESDAY BUT THE EURO IS SLOWER AND SUGGESTS A CONVECTIVE THREAT LINGERING ALL DAY TUESDAY. WEDNESDAY THROUGH SATURDAY IS DOMINATED BY A LARGE/DRY AREA OF HIGH PRESSURE. THIS FEATURE WILL BRING A THREAT OF FROST EACH NIGHT... WITH SUNNY/PLEASANT CONDITIONS AND HIGHS IN THE 50S/60S EXPECTED FOR THE DAYS. DIURNAL TEMP SWINGS SHOULD BE RATHER LARGE DUE TO THE DRY AIR MASS AND MAINLY CLEAR SKIES. CONSIDERING THAT THE LOW LEVEL FLOW SHOULD BE PREDOMINATELY NORTHEASTERLY... WOULD EXPECT THE WARMEST HIGH TEMPERATURES TO BE IN THE WRN HALF OF THE CWFA DURING THE MID TO LATE WEEK PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 750 AM EDT SUN APR 1 2012 MVFR CONDITIONS DUE TO 3-5 MILE VSBYS IN LIGHT FOG WERE PRESENT EARLY THIS MORNING. CIGS WERE MOSTLY 4-6K FEET WITH A FEW LIGHT RAIN SHOWERS OR VIRGA/SPRINKLES DOTTING THE REGION. DRIER AIR IS EXPECTED TO FLOW INTO THE REGION TODAY FROM NORTH TO SOUTH AS A WEAK SFC FRONT PASSES THROUGH AND SETTLES SOUTH OF MI THIS AFTERNOON. VSBYS ARE EXPECTED TO INCREASE ABOVE 6SM WITH THE 4-6K CLOUD DECK SCATTERING OUT AS THE FRONT COMES THROUGH AND WINDS SHIFT NORTHERLY AROUND 8 KTS. OPTED TO LEAVE THE MENTION OF TS/CB OUT OF THE I-94 CORRIDOR TAF SITES SINCE THE ACTIVITY CURRENTLY OVER CHICAGO IS SLIDING SE AND SHOULD NOT BE A FACTOR. ANY REDEVELOPMENT LATER TODAY SHOULD BE JUST SOUTH OF THE MI BORDER NEAR THE SFC FRONT. && .MARINE... ISSUED AT 400 AM EDT SUN APR 1 2012 WINDS/WAVES WILL REMAIN UNDER SMALL CRAFT ADVISORY CRITERIA TODAY INTO EARLY NEXT WEEK. && .HYDROLOGY... ISSUED AT 400 AM EDT SUN APR 1 2012 NO HYDRO CONCERNS DUE TO LITTLE IF ANY PCPN TODAY... LIGHT QPF AMOUNTS MONDAY NIGHT/TUE FOLLOWED BY DRY WX MID TO LATE WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...OSTUNO SHORT TERM...OSTUNO LONG TERM....MEADE AVIATION...MEADE HYDROLOGY...LAURENS MARINE...LAURENS
AREA FORECAST DISCUSSION...UPDATED FOR 06Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
1040 PM CDT MON APR 2 2012 .DISCUSSION... /ISSUED 330 PM CDT MON APR 2 2012/ SEVERE WEATHER THREAT REMAINS MAIN FOCUS FOR THE EVENING. LATEST AVAILABLE RUC INDICATING WARM SECTOR TO WORK INTO SOUTH CENTRAL MINNESOTA THIS EVENING. MLCIN DROP OFF MARKEDLY AS WELL...BUT BELIEVE CAP WILL HOLD FOR ANY REAL SURFACE BASED CONVECTION. SHOULD SEE ELEVATED ACTIVITY INITIATE OVER SOUTHWEST MINNESOTA NEAR REDWOOD FALLS...AND THEN MOVE EAST DURING THE EVENING...AFFECTING SOUTH CENTRAL MINNESOTA. MOST ALL DETERMINISTIC RUNS INDICATE THIS AS WELL. VERY STEEP/UNSTABLE MID LEVEL LAPSE RATES IN EXCESS OF 8C/KM WITH ELEVATED CAPE AROUND 1200 J/KG MOVING...SHOULD BE ENOUGH TO GENERATE THE CONVECTION. HAIL WILL BE THE MAIN THREAT WITH SOME WIND POSSIBLE AS WELL. UPPER TROUGH MOVES ACROSS THE CWA OVERNIGHT...AND IS SLOWER THAN WHAT MODELS WERE SHOWING YESTERDAY. WILL HAVE TO LINGER SOME SLIGHT CHANCE POPS OVER THE SOUTHERN CWA INTO TUESDAY MORNING... WITH CLEARING EXPECTED THEREAFTER. COOLER TEMPERATURES EXPECTED THEN FOR THE NEXT SEVERAL DAYS...BUT STILL RANGING ABOVE NORMAL. NORTHERLY WINDS WILL INCREASE TONIGHT BEHIND DEPARTING SYSTEM AND WILL REMAIN BREEZY INTO TUESDAY AS THE COLDER AIR MOVES IN. WINDS WILL DIMINISH TUESDAY EVENING AND WITH LARGE HIGH PRESSURE DROPPING SOUTH OVER THE AREA...WILL LIKELY SEE SOME FROST DEVELOP INTO WEDNESDAY MORNING. PREVIOUS FORECAST HAD THIS MENTIONED AND STILL LOOKS GOOD. THERE WILL BE ANOTHER OPPORTUNITY FOR FROST...MAINLY OVER WEST CENTRAL WISCONSIN WEDNESDAY NIGHT/THURSDAY MORNING AS THE HIGH RETREATS TO THE EAST. LONG RANGE MODELS CONTINUE TO TREND ANOTHER WAVE ACROSS THE AREA LATER FRIDAY NIGHT INTO SATURDAY SATURDAY NIGHT TIME FRAME. EVEN COLDER AIR TO FOLLOW THIS FRONT...POSSIBLE MAKING TEMPERATURES CLOSER TO NORMAL FOR THIS TIME OF THE YEAR. && .AVIATION.../06Z TAF ISSUANCE/ A COUPLE OF AREAS OF ELEVATED TSTMS HAVE DEVELOPED IN PAST HOUR OR SO. ONE IS AN E-W BAND MAINLY ACROSS THE S TWIN CITIES METRO ON N EDGE OF B5 850 MB LIFTED INDEX GRADIENT. THESE STORMS HAVE BEEN MOVING ENE AND SHUD REMAIN MAINLY S OF MSP/RNH BUT A WINDOW OF AN HOUR OR SO AROUND TAF IDSSUE TIME. A LONGER WINDOW OF OPPORTUNITY AT EAU WHERE THEY MAY LINGER UNTIL 08-09Z. OTHER AREA OF ISOL TSTMS HAS BEEN DVLPG IN WC INTO CNTRL MN AHD OF UPPER TROF. CIGS GENERALLY AROUND 4K ATTM...BUT WITH PCPN SHUD SEE SOME MVFR CIGS DVLP IN THE OVERNITE INTO TUESDAY MRNG. AS SFC LOW IN NW IA CONTINUES TO DROP ESE OVERNITE INCREASING SFC PRESSURE GRADIENT WILL DEVELOP ACROSS AREA WITH NNE WINDS GUSTING 20-25 KTS. KMSP...A THREAT OF THUNDER UNTIL AROUND 07Z AS CONVECTION S OF MSP MOVES ENE. ENE WINDS WILL BECOME MORE NE NEXT FEW HOURS AND BECOME STRONGER AS PRESSURE GRADIENT INCREASES ACROSS AREA. FAIRLY UNIFORM CIGS ARND 4000 FT ACROSS AREA SHUD DIP INTO MVFR RANGE WITH PCPN IN AREA. IMPRVG CIGS ARND 15Z TO VFR BCMG MAINLY SKC LATE AFTN. OUTLOOK... /TUE NIGHT-FRI/...VFR AS HIGH PRESSURE MOVES ACROSS. /SAT-SUN/...POSSIBLE FRONTAL SYSTEM MOVES OVER THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY. MVFR CONDS POSSIBLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
702 PM CDT MON APR 2 2012 .UPDATE... UPDATED FOR AVIATION DISCUSSION BELOW. && .DISCUSSION... /ISSUED 330 PM CDT MON APR 2 2012/ SEVERE WEATHER THREAT REMAINS MAIN FOCUS FOR THE EVENING. LATEST AVAILABLE RUC INDICATING WARM SECTOR TO WORK INTO SOUTH CENTRAL MINNESOTA THIS EVENING. MLCIN DROP OFF MARKEDLY AS WELL...BUT BELIEVE CAP WILL HOLD FOR ANY REAL SURFACE BASED CONVECTION. SHOULD SEE ELEVATED ACTIVITY INITIATE OVER SOUTHWEST MINNESOTA NEAR REDWOOD FALLS...AND THEN MOVE EAST DURING THE EVENING...AFFECTING SOUTH CENTRAL MINNESOTA. MOST ALL DETERMINISTIC RUNS INDICATE THIS AS WELL. VERY STEEP/UNSTABLE MID LEVEL LAPSE RATES IN EXCESS OF 8C/KM WITH ELEVATED CAPE AROUND 1200 J/KG MOVING...SHOULD BE ENOUGH TO GENERATE THE CONVECTION. HAIL WILL BE THE MAIN THREAT WITH SOME WIND POSSIBLE AS WELL. UPPER TROUGH MOVES ACROSS THE CWA OVERNIGHT...AND IS SLOWER THAN WHAT MODELS WERE SHOWING YESTERDAY. WILL HAVE TO LINGER SOME SLIGHT CHANCE POPS OVER THE SOUTHERN CWA INTO TUESDAY MORNING... WITH CLEARING EXPECTED THEREAFTER. COOLER TEMPERATURES EXPECTED THEN FOR THE NEXT SEVERAL DAYS...BUT STILL RANGING ABOVE NORMAL. NORTHERLY WINDS WILL INCREASE TONIGHT BEHIND DEPARTING SYSTEM AND WILL REMAIN BREEZY INTO TUESDAY AS THE COLDER AIR MOVES IN. WINDS WILL DIMINISH TUESDAY EVENING AND WITH LARGE HIGH PRESSURE DROPPING SOUTH OVER THE AREA...WILL LIKELY SEE SOME FROST DEVELOP INTO WEDNESDAY MORNING. PREVIOUS FORECAST HAD THIS MENTIONED AND STILL LOOKS GOOD. THERE WILL BE ANOTHER OPPORTUNITY FOR FROST...MAINLY OVER WEST CENTRAL WISCONSIN WEDNESDAY NIGHT/THURSDAY MORNING AS THE HIGH RETREATS TO THE EAST. LONG RANGE MODELS CONTINUE TO TREND ANOTHER WAVE ACROSS THE AREA LATER FRIDAY NIGHT INTO SATURDAY SATURDAY NIGHT TIME FRAME. EVEN COLDER AIR TO FOLLOW THIS FRONT...POSSIBLE MAKING TEMPERATURES CLOSER TO NORMAL FOR THIS TIME OF THE YEAR. && .AVIATION.../00Z TAF ISSUANCE/ STILL LOOKS LIKE A THUNDER THREAT FROM SC MN INTO WISC AND WILL MENTION TSRA AT KMSP/KRNH/KEAU DURING THE LATE EVENING. EXCELLENT ELEVATED INSTABILITY PRESENT AMONG OTHER FACTORS. CONFIDENCE ABOUT AVERAGE. OTHERWISE SHOWERS MAY DEVELOP FOR A SHORT WHILE THIS EVENING IN WC MN INTO CENTRAL MN BUT CONFIDENCE IN THIS IS BELOW AVERAGE. ONCE SFC LOW GOES BY ALONG THE SW MN/NW IA BORDER AND INTO EASTERN IOWA...PRECIP WILL TRANSITION TO STRATIFORM AND MVFR CEILINGS LOOK TO BE A GOOD BET. TOO MUCH WIND AND COLD ADVECTION FOR FOG. A COUPLE MODELS DO HANG ON TO MVFR CLOUDS LONGER THAN PREVIOUSLY FORECAST AND THIS LOOKS REASONABLE SO HAVE MAINTAINED MVFR INTO THE LATE MORNING IN WC MN AND EARLY AFTERNOON IN WISC. KMSP...HAVE ADDED THUNDER AS DECENT AMOUNT OF ELEVATED INSTABILITY CLIPS THE METRO AFTER 03Z. THERE HAS BEEN A HINT OF SOME DEVELOPMENT IN THE CU FIELD TO THE SOUTHWEST AND THIS APPEARS TO BE WHAT MODELS ARE PICKING UP ON FOR CONVECTIVE DEVLOPMENT. CONFIDENT AVERAGE INTHIS. AFTER THIS GOES BY...PRECIP SHOULD TRANSITION TO STRATIFORM AND HAVE KEPT MVFR CEILINGS AFTER 07Z AND ALL THE WAY TO 17Z. CONFIDENCE ABOVE AVERAGE IN THE EXISTENCE OF THE MVFR THOUGH TIMING MAY VARY AN HOUR OR TWO ON EITHER SIDE. SKY SHOULD BECOME VFR AROUND MIDDAY TUESDAY AND IN FACT MOSTLY CLEAR. OUTLOOK... /TUE NIGHT-FRI/...VFR AS HIGH PRESSURE MOVES ACROSS. /SAT-SUN/...POSSIBLE FRONTAL SYSTEM MOVES OVER THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY. MVFR CONDS POSSIBLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 AM CDT SUN APR 1 2012 LARGE AREA OF LOW CLOUDS/FOG HAS PERSISTED ACROSS MOST OF CWA OVERNIGHT AS APPROACHING FRNTL SYSTEM HAS STALLED/WEAKENED UNDERNEATH BUILDING MID LVL RIDGE. RUC13 SHOWS WINDS NORTH OF FRNTL BDRY AT 925 HAVE ALREADY SWITCHED TO NE INDICATING NOT MUCH PUSH TO GET THE BDRY THROUGH ANYTIME SOON. MSAS HAS PRESS RISES WEAKENING NORTH OF BDRY AS WELL. SFC T/TD SPREADS ARE NEAR ZERO OVER MOST OF NRN CWA WHERE MSTR HAS POOLED AHEAD OF DECAYING FRONT. LOCALLY DENSE FOG AT THIS TIME ACROSS NRN ITASCA/KOOCH/NRN STL COUNTIES. WILL ISSUE DFA FOR EARLY MORNING. TODAY..WIDESPREAD CLOUDS/FOG SHOULD GRADUALLY DIMINISH BY MIDDAY AS MID LVL RIDGE AXIS SHIFTS EAST TOWARDS LAKE SUPERIOR. BDRY LYR FLOW WILL INCREASE FROM SOUTHEAST DURING AFTN AND CEILINGS SHOULD LIFT. CLOUD FCST WILL BE CHALLENGING TODAY BUT HAVE LEANED WITH WRF ARW 4KM IDEA THAT CLEARING WILL ADVECT FROM MPX CWA BY LATE MORNING. HAVE USED A BIAS CORRECTED BLEND OF THE EC/ALLBLEND TO FCST MAX TEMPS. THIS ALSO RESPECTS THE BRISK ONSHORE COMPONENT THAT DEVELOPS THIS AFTN AS MESOSCALE WEDGE OF HIGH PRESSURE NOSES DOWN LAKE FROM ONTARIO. TONIGHT...CYCLOGENESIS OVER WRN HI PLAINS CREATES STRENGTHENING WARM ADVECTION PATTERN ACROSS NRN PLAINS. LLJ IS FCST TO PUSH INTO CWA WITH ELEVATED CONVECTION DEVELOPING AFTER 6Z. USING SREF CPTP AND EC/NAM CONVECTIVE FCSTS OF SHEAR/MUCAPE PUTS INCREASING LIKELIHOOD OF THUNDER INTO SWRN CWA MIDNIGHT...THEN ACROSS MOST OF CWA EXCEPT ERN ARROWHEAD BY 12Z. SREF 3HR CALIBRATED SVR VALUES QUITE LOW AT THIS TIME. TOMORROW...SFC LOW WILL TRACK INTO SWRN MN BY 0Z TUES. MAIN PUSH OF 85H MSTR TRANSPORT WILL BE FOCUSED ACROSS NRN TIER OF CWA WHERE LOCALLY HEAVY PRECIP IS POSSIBLE. EC/GEM/NAM IN MDT AGREEMENT THAT STRONG LOW LVL INVERTED TROUGH WILL BE AIDED BY APPROACHING UPPER TROF. MID LVL WARM ADVECTION MAY LIMIT MUCH PRECIP DEVELOPMENT OVER WISC ZONES..AND PERHAPS AS FAR NORTH AND WEST AS TWIN PORTS. LATER SHIFTS MAY NEED TO LOWER POPS EVEN FARTHER IN THIS AREA. .EXTENDED...MONDAY NIGHT THROUGH SATURDAY... AN UPPER LEVEL TROF WILL MOVE INTO THE FA MONDAY NIGHT PUSHING A SFC FRONT INTO NORTH CENTRAL WI BY 12Z TUESDAY. SHOWERS AND THUNDERSTORMS WILL OCCUR AHEAD OF THE TROF AND NEAR THE FRONT. THE TROF REACHES NE WI BY 00Z WEDNESDAY AND PUSHES THE FRONT WELL E OF THE AREA AND ENDS THE PCPN. TUESDAY NIGHT THROUGH FRIDAY WILL BE DOMINATED BY HIGH PRESSURE OVER THE GREAT LAKES. BY FRIDAY NIGHT...RETURN FLOW SETS UP AS THE SFC HIGH SLIPS FARTHER TO THE E. A STRONG LLJ AT 850MB WILL USHER IN WARM/MOIST AIR. ENOUGH DESTABILIZATION OCCURS TO MENTION SOME POPS OVER THE WESTERN TWO THIRDS OF THE FA. POPS ARE SPREAD OVER THE ENTIRE FA ON SATURDAY AS A CLOSED/STACKED UPPER LOW MEANDERS THROUGH THE NORTHERN PLAINS...SENDING PIECES OF ENERGY TOWARD THE FA. .AVIATION...06Z TAFS IFR OR LOW MVFR CEILINGS COVERED MOST OF THE NORTHLAND...WITH CLEAR SKIES FROM WALKER TO COOK TO CRANE LAKE AND POINTS NORTH AND WEST. SATELLITE DID SHOW THE STRATUS WAS MOVING BACK TOWARD THE WEST AND NORTH TOWARD WALKER. FOG WAS ALSO DEVELOPING...AND VSBYS SHOULD CONTINUE TO DROP OVERNIGHT. LOW LEVEL WINDS WILL BE VEERING TO EASTERLY LATE TONIGHT INTO SUNDAY...AND DENSE FOG MAY DEVELOP AROUND LAKE SUPERIOR AS AN ONSHORE FLOW DEVELOPS. NAM BUFR SOUNDINGS CONTINUE TO SHOW THE CEILINGS LIFTING QUICKLY ON SUNDAY...BUT WE HAVE LOW CONFIDENCE IN THAT OCCURRING GIVEN THE EASTERLY LOW LEVEL FLOW. MOISTURE/WARM AIR ADVECTION WILL BE INCREASING SUNDAY NIGHT...WITH THE STABILITY DROPPING. THE MODELS DO SHOW SHOWERS/STORMS DEVELOPING OVER PARTS OF THE NORTHLAND BY LATE EVENING. SOME OF THE STORMS COULD BE QUITE STRONG. .POINT TEMPS/POPS... DLH 55 41 54 38 / 10 30 40 50 INL 63 40 53 33 / 10 50 60 40 BRD 67 50 64 38 / 10 40 50 40 HYR 67 45 64 39 / 10 30 30 50 ASX 58 43 58 38 / 10 30 30 50 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MNZ010>012- 018-019-021-025-026. WI...NONE. LS...NONE. && $$ SHORT TERM...CANNON LONG TERM....GSF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1201 AM CDT SUN APR 1 2012 .UPDATE... UPDATED FOR THE 06Z AVIATION DISCUSSION BELOW. && .DISCUSSION... CONSIDERABLE CLOUDINESS CONTINUES TO PLAGUE MUCH OF THE FA AT MID AFTERNOON. ONLY THE FAR WESTERN COUNTIES HAVE NEAR FULL SUN. SOME THINNING APPEARS TO BE OCCURRING OVER WEST CENTRAL WI. THE HRRR IS TRYING TO SHOW CLEARING WORKING INTO FAR EASTERN MN AND WEST CENTRAL WI BY THIS EVENING. HOWEVER...CLEARING OR NOT...THE PRESSURE GRADIENT WILL WEAKEN TONIGHT WITH SATURATION DEVELOPING DURING THE OVERNIGHT HOURS. THIS WILL LIKELY TO LEAD FOG AND MORE STRATUS REFORMING. NAM BUFKIT HYDROLAPSE SHOWS A NICE INCREASE JUST ABOUT EVERYWHERE TONIGHT DURING THE LATE NIGHT HOURS. INDICATED AREAS OF FOG IN THE FORECAST...BUT DENSE FOG IS NOT OUT OF THE QUESTION SUNDAY MORNING. IN ADDITION...A WEAK SHORT WAVE IS PASSING BY EARLY THIS EVENING. SEVERAL MODEL SOLUTIONS STILL TRY TO DEVELOP SOME SHOWERS OVER CENTRAL MN AND PASS THEM ACROSS THE TWIN CITIES AND WEST CENTRAL WI. CONFIDENCE IS NOT HIGH AND HAVE KEPT THE FORECAST DRY BUT THE DIFFERENTIAL HEATING OCCURRING TO OUR WEST NOW IS A CONCERN. MUCH BETTER INSTABILITY IS DEVELOPING OVER WESTERN IA ATTM AND THE LOW LEVEL MOISTURE TRANSPORT INCREASES EARLY THIS EVENING BETWEEN KDSM AND KMKE. SO SOME STORMS ARE POSSIBLE JUST TO OUR SOUTH OF OUR FA THIS EVENING. SUNDAY WILL BE THE WARMEST DAY OF THE NEXT SEVEN FOR MANY AREAS. MUCH WILL DEPEND ON THE AMOUNT OF STRATUS AND FOG IN THE MORNING...BUT WEST CENTRAL THROUGH SOUTH CENTRAL MN HAVE A REALLY GOOD CHANCE OF SEEING HIGHS REACH WELL INTO THE 80S. READINGS IN THE 80S ARE OCCURRING RIGHT NOW TO THE WEST AND SOUTH OF KFSD WITH H85 TEMPERATURES OF +16 TO +18 DEGREES C. SOUTHWEST AREAS OF MN WILL BE SOME 2 TO 3 DEGREES C ABOVE THIS SUNDAY AFTERNOON. A HIGH NEAR 90 IS NOT OUT OF THE QUESTION AROUND LUVERNE AND PIPESTONE. A LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL BOUNDARIES WILL MOVE INTO THE FA SUNDAY NIGHT. ELEVATED INSTABILITY DEVELOPS BY EVENING NORTH OF THE WARM FRONT ACROSS CENTRAL MN AND PUSHES INTO NORTHWEST WI DURING THE NIGHT. LOW LEVEL MOISTURE TRANSPORT INCREASES DRAMATICALLY ACROSS EAST CENTRAL MN AS THE LOW LEVEL JET INCREASE TO 40 KNOTS. LAPSE RATES ARE BETTER THAN 6.5 DEG C/KM ALONG WITH A FAVORABLE DIFFERENTIAL TEMPERATURE ADVECTION PATTERN. THE CROSSOVER BETWEEN 850 AND 500 MB IS RATHER IMPRESSIVE BUT A LITTLE NORTH OF OUR CWA. ALL OF THIS POINTS TO SOME STORMS DEVELOPING ACROSS CENTRAL MN AND MOVING TOWARDS KDLH. A FEW STORMS WITH LARGE HAIL MAY OCCUR. THERE STILL REMAINS MODEL SPREAD FROM MONDAY THROUGH TUESDAY ON MOVING THE LOW AND TRAILING COLD FRONT ACROSS THE FA. THE ECMWF REMAINS THE SLOWEST WHILE THE NAM IS THE FASTEST. THE GEM AND GEFS ARE PRETTY SIMILAR. TRIED TIMING PRECIPITATION BASED ON THIS COMBINATION. THIS YIELDED LIKELY POPS OVER EAST CENTRAL MN MONDAY AFTERNOON AND ACROSS PARTS OF WEST CENTRAL WI MONDAY EVENING. HIGH TEMPERATURES ON MONDAY MAY BE WARMER THAN FORECAST FOR SOUTHEAST AREAS OF THE FA IF THE CLOUDINESS/SHOWERS/THUNDERSTORMS DO NOT DEVELOP AS FORECAST. DRY WEATHER FORECAST IN THE WAKE OF THE FRONT FOR TUESDAY THROUGH FRIDAY AS HIGH PRESSURE STALLS OVER THE WESTERN GREAT LAKES. HIGHS DURING THE PERIOD FROM 55 TO 65 WITH LOWS FROM 35 TO 45. A PACIFIC COLD FRONT IS THEN PROJECTED ACROSS THE REGION FOR NEXT SATURDAY. HOWEVER...THE ECMWF REMAINS THE SLOWEST ON MOVING THE FRONT THROUGH ALONG WITH WEAKENING THE SYSTEM AS IT APPROACHES. FOR NOW...INDICATED ONLY A SMALL CHANCE FOR RAIN SHOWERS. && .AVIATION.../06Z TAF ISSUANCE/ DIFFICULT CEILING FCST THRU THE NEXT 24 HRS DUE TO THE SLOW PROGRESSION OF THE SFC FRONTS OVER WRN MN/ERN DAKOTAS COMBINED WITH THICK ENOUGH LOW CLOUDS PREVENTING MIXING. FOG SATELLITE PRODUCE SHOWS LARGE SWATH OF LOW STRATUS WITH FOG ENCOMPASSING THE AREA. WITH ONE TAF SITE...KAXN...ALREADY WELL INTO THE LIFR CATEGORY...SEE NO REASNO WHY THE OTHERS WOULD NOT GET THERE...ESP THOSE THAT WOULD BE E AND N OF THE SFC BOUNDARIES. WILL LOOK FOR ALL TAF SITES TO GET DOWN TO A VARIATION OF IFR-OR-WORSE...WHETHER FROM CIG OR VSBY...THROUGH DAYBREAK. ONCE PAST THE DEGRADED FLIGHT CONDS THROUGH DAYBREAK...QUESTION BECOMES HOW LONG WILL THE IFR- TO-MVFR CIGS LAST THROUGH THE AFTN. MODELS SUGGEST DELAYED PROGRESSION OF THE WMFNT OUT WEST...WHICH WOULD KEEP LOW LEVEL EAST-TO-SOUTHEAST WINDS IN PLACE THRU THE DAY AND HENCE THE LOW MOISTURE WHICH WOULD NOT MIX OUT WELL AND KEEP LOW STRATUS GOING. HAVE ADVERTISED THIS TREND FOR ALL BUT KAXN AND KRWF...WHICH WOULD BE MOST LIKELY TO CLEAR OUT. HIGH CIRRUS WOULD THEN PREVAIL THRU THE EVENING UNTIL HIGH CLOUDS LOWER AND THICKEN TMRW NIGHT. MSP...CIGS MAINTAINING AT LOWER-END MVFR AND WILL LOOK FOR THEM TO TOUCH INTO IFR BEFORE SLOWLY RISING OUT DURG THE DAY TMRW. HOWEVER...THAT RISE WILL BE SLOW SO WILL MAINTAIN MVFR CIGS THROUGH THE DAY. DIFFICULT TO TELL IF THE CIGS WILL BE ABOVE OR BELOW THE 1700 FT THRESHOLD BUT GIVEN THAT THE CHANGE HAS BEEN MADE TO DELAY CLEARING WITH THIS ISSUANCE...HAVE COMPROMISED AND KEPT THE LATE MRNG THRU AFTN CIGS AT 2000 FT. CLOUDS SCATTER OUT LATE DAY THEN HIGH CLOUDS FILL IN. OUTLOOK... /SUN NIGHT-MON NIGHT/...FRONTAL SYSTEM MOVING THRU WILL PRODUCE SHWRS AND TSTMS ACRS THE REGION. MVFR-IFR CONDS LIKELY. /TUE-THU/...VFR UNDER HIGH PRESSURE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
845 PM CDT Mon Apr 2 2012 .UPDATE... /832 PM CDT Mon Apr 2 2012/ Cold front is clearly evident on OAX radar making steady southeastward progress toward extreme northwest MO. Further to the southwest, a nearly stationary convective complex has formed along the front across central and southwest Kansas. Storm motion vectors will keep that activity well west of the area overnight. 00Z TOP sounding shows a very dry and stable low-level airmass in place, though OAX sounding is slightly deeper with the low-level moisture and thus weaker with convective inhibition. As the cold front progresses southeastward, a few showers or storms can`t be ruled out across far northwest MO in this slightly more favorable airmass before the front encounters the very stable air further south. Updated to keep slight chance PoPs through 09Z across far northwest MO and dry elsewhere. Later tonight, NAM and to a lesser extent GFS and RUC suggest the higher 850-hPa theta-e evident on the 00Z OUN sounding may stream into eastern KS and western MO toward 12Z. This may yield enough elevated instability for a few convective cells to develop toward sunrise across these areas, though low-level wind fields will be decreasing to below 10 kts by this time so forcing will be very limited. Will maintain slight chance to low chance PoPs across the western CWA from 09Z to 12Z. Due to the very weak low-level wind fields anything that does develop is unlikely to be severe. Hawblitzel && .DISCUSSION... Short Range (Tonight through Wednesday)... Water vapor imagery shows us that the cutoff low, that we have been focusing on for many days as our weather maker for the week, is currently in the process of forming across the Desert Southwest. As the low develops, the parent trough to the developing low is already moving east along the Canadian border as it begins to ride up and over the ridge across the nations mid-section. This shortwave will be responsible for a cold front that will shift southeast through eastern Kansas and Missouri later tonight. A little closer to home, another notable feature is seen shifting northeast along the Texas Gulf Coast, generating thunderstorm activity well to our south. For tonight, the modest shortwave shifting east along the Canadian border today has helped lift a weak warm front north through Missouri with pressure falls across the Northern Plains, but later tonight the same shortwave will help drag a cold front southeast through Kansas and the northern half of Missouri as the wave shifts farther east. Speaking of the cold front, it is currently oriented almost north south across central Kansas this afternoon, with some modest CU noted popping up in the vicinity of the associated dryline. As the rest of the front settles southeast during the evening hours, convergence across central Kansas, in combination with available CAPE, could generate some convection tonight. However, the potential for these storms to work east into far eastern Kansas and Western Missouri looks limited as the low level jet will be focused across central Kansas as the cutoff low shifts into the Plains States. Will keep some some slight chance pops across our western border for the evening hours, with chance POPs after midnight as that would be the typical timing for any activity that started in central Kansas to reach western Missouri. However, while the potential for storms looks low, any that do pop-up will need close watching, especially if they approach far northwest Missouri, where shear parameters would be sufficient to support some severe weather. For Tuesday and Wednesday, models continue to show a high degree of agreement as to the track of the cutoff low across the Central Plains. However, the total amount of rain, or when and where the storms associated with the low will be is a little harder to pick out. But, at this time confidence is high enough to continue broad brushing chance POPs in for the day Tuesday as moisture advects north along the ascending isentropic surfaces, with likely POPs in from Tuesday night through Wednesday night as this becomes maximized as the low shifts east across Kansas and Missouri. Cutter Medium Range (Thursday through Monday)... The upper low should be moving east of the region by late Thursday but there should remain decent chances for showers early in the day that diminish by the evening. The best chances for rain should be across our eastern zones, which will be closer to the center of the upper low. Once the low exits the region a surface ridge of high pressure will move into the Midwest with what appears to be a relatively dry (compared to recently) airmass. With the surface ridge axis draped across the area we could see a fairly chilly start to the day on Friday, especially across northeastern Missouri where lows may fall into upper 30s. With how warm it has been recently we may need to monitor Friday morning for even colder temperatures. A larger system will track across the Northern Plains and upper Midwest Saturday into Sunday which will send a frontal boundary through the region Saturday evening/night. This will bring another good chance for showers and thunderstorms to region. It`s still a little early to say there may or may not be severe weather but it looks like there will be decent convergence along the front and high enough shear for storm organization. The real question is what amount of instability will develop during the day. The GFS is more robust with the instability than the ECMWF and if enough instability can materialize there could at least be some strong storms Saturday afternoon/evening. Biggest deviation from the forecast initialization was to remove POPs from about 12Z Sunday onward. With the front pushing south of the region it seems unlikely we`d get much precipitation to occur with a much drier airmass moving into the region. CDB && .AVIATION... For the 00Z TAFs...developing convection over central KS is expected to remain well west of KC terminals this evening, as a capping inversion overhead will make it very difficult for precip to make it this far east. Can`t rule out some late nocturnal convection developing toward sunrise as a front moves in from the north, but chances for this appear to low to include in the TAFs at this time. MVFR cigs behind the front may make it as far south as STJ...possibly even MCI...but forecast soundings indicate this moisture should become more scattered in nature as it gets this far south. Slightly better chances for convection will exist Wednesday afternoon, especially south of the KC area. Hawblitzel && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1023 AM MDT SUN APR 1 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY... UPDATED THE FORECAST TO LOWER THE CHANCE OF RAIN PER THE CURRENT RADAR AND THE HRRR MODEL FOR THIS MORNING AND AFTERNOON. ALSO LOWERED SKY COVER FOR THE AFTERNOON. REST OF THE SHORT TERM FORECAST IS ON TRACK. RSMITH PREVIOUS DISCUSSION...SPLITTING UPPER TROF MOVING ACROSS THE WEST COAST...WILL BE FORMING A CUT OFF LOW OVER THE FOUR CORNERS WHILE THE NORTHERN PORTION LIFTS ACROSS MONTANA AND INTO CENTRAL CANADA THROUGH MONDAY. COLD FRONT ALONG THE WESTERN BORDER OF CWA WITH SHOWERS AND A FEW THUNDERSTORMS STREAMING NORTHWARD ACROSS CENTRAL MONTANA. WEAK SURFACE LOW DEVELOPING OVER SOUTHEAST MONTANA EXPECTED TO PUSH TO THE NORTHEAST TODAY WHILE COLD FRONT MOVES ACROSS EASTERN MONTANA. AREA OF SHOWERS AND THUNDERSTORMS ALSO EXPECTED TO BE LIFTING NORTH SO MAINLY WILL BE AFFECTING THE FAR WESTERN ZONES THIS MORNING. STRONG COLD AIR ADVECTION BEHIND THE FRONT ALONG WITH TIGHTENING PRESSURE GRADIENT WILL RESULT IN STRONG WEST WINDS BY AFTERNOON PERSISTING INTO THE EVENING. AS SHOWERS MOVE NORTH AND WIND INCREASE...RELATIVE HUMIDITY IS EXPECTED TO DROP IN THE AFTERNOON... BRINGING ON CRITICAL FIRE WEATHER CONDITIONS. COLD AIR ADVECTION CONTINUES THROUGH SUNDAY NIGHT WITH THE UPPER TROF MOVING ACROSS THE STATE. THIS WILL KEEP WINDS FROM DIMINISHING COMPLETELY. BY MONDAY MORNING RIDGE BEGINS REBOUNDING OVER THE NORTHERN ROCKIES BUT COLD AIR WILL LINGER OVER EASTERN MONTANA. WINDS WILL KICK UP AGAIN IN THE AFTERNOON WITH GOOD MIXING EXPECTED. UPPER RIDGE SPREADS OVER THE NORTHERN PLAINS ON TUESDAY WITH WARMER AIR PUSHING INTO THE TREASURE STATE. HIGH PRESSURE MOVES INTO THE CENTRAL PLAINS WITH WINDS GOING AROUND TO THE SOUTH AND WEAK LEE TROF DEVELOPING IN CENTRAL MONTANA. EBERT .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY... SYNOPTIC SET UP AS OF TUESDAY AFTERNOON... TO THE EAST A COLD AIR POOL OVER THE HUDSON BAY IS DIVING INTO THE GREAT LAKES. A RIDGE RIDES FROM DEATH VALLEY THROUGH CENTRAL MONTANA AND UP INTO NORTHERN ALBERTA. A LONG WAVE TROUGH STRETCHES FROM YUKON TO THE COAST OF BRITISH COLUMBIA DOWN TO OFF THE COAST OF NORTHERN CALIFORNIA. FURTHER UP STREAM A SMALL RIDGE/TROUGH COMBO LIES JUST SOUTH OF THE ALEUTIANS. TUESDAY NIGHT THROUGH WEDNESDAY... RIDGE WILL BE IN FULL CONTROL OVER THE AREA AND SHOULD PRECLUDE ANY SHOWERS WITH A SEMI STABLE ATMOSPHERE. ANTICIPATE PARTLY CLOUDY TO CLEAR SKIES. WEDNESDAY NIGHT THROUGH FRIDAY... OFF SHORE TROUGH WILL MOVE OVER THE INTERMOUNTAIN WEST AND BEGIN IMPACTING THE CENTRAL MONTANA. INITIALLY THUNDERSHOWERS WILL BE POSSIBLE DUE TO THE RIDGE BREAKING DOWN AND LEE SIDE MOUNTAIN TROUGH SETTING UP THURSDAY AFTERNOON. SOUTHWEST FLOW WILL ALSO BEING PUMPING MID LEVEL MOISTURE AND MESOSCALE DISTURBANCES INTO THE REGION AS WELL. THURSDAY NIGHT INTO FRIDAY A SURFACE LOW WILL BEGIN TO FORM AND DRAG IN COLD AIR BEHIND THE SYSTEM. THE CONTRAST WILL PROVIDE LIFT BUT SHOULD TURN IT INTO A STRATIFORM EVENT BY FRIDAY. FRIDAY NIGHT ONWARD... MODELS ARE SWINGING AROUND A BIT AND CONFIDENCE IS BELOW AVERAGE. WHERE AT FIRST WENT WITH AND EC/GEM 12Z BLEND THE NEW CONSENSUS IS GFS/EC 00Z BLEND. GOING PREDOMINATELY PERSISTENCE AND USING SLIGHT BLENDS. SURFACE LOW PREVIOUSLY WAS KICKED OUT TO THE EAST EARLY BUT NOW HOLDS ON OVER SOUTHERN CANADA BEFORE EXITING SATURDAY AFTERNOON. REGION LOOKS TO PUSH FOR ZONAL SO MODERATED TEMPERATURES OUT BY BLUNTING ANY COLD OR WARM PUSHES. GAH && .AVIATION... VFR WITH ISOLATED SHOWERS THIS MORNING ACROSS THE TERMINALS. THE WINDS WILL BE OUT OF THE EAST AT 5 TO 15 KNOTS DURING THE EARLY MORNING. BY LATE MORNING TO MIDDAY A COLD FRONT WILL BACK THE WINDS TO THE NORTHWEST AND INCREASE THEM TO AROUND 20 KTS GUSTING TO 30 KTS. KGDV TERMINAL AWOS EQUIPMENT IS HAVING PROBLEMS WITH VISIBILITY AND OCCASIONAL CEILINGS IN METARS. AMENDMENTS WILL BE LIMITED TO WINDS ONLY. GAH && .FIRE WEATHER... A COLD FRONT WILL CROSS EASTERN MONTANA THIS MORNING WITH SLIGHTLY COOLER BUT WINDIER CONDITIONS EXPECTED. RH WILL AGAIN DIP INTO THE LOWER 20S DRIVING ANOTHER ROUND OF CRITICAL FIRE WEATHER CONDITIONS ACROSS ALL OF NORTHEAST MONTANA. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR MTZ120-122-134>137. LAKE WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR FORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1100 PM CDT MON APR 2 2012 .UPDATE...UPDATED THE FORECAST TO INCREASE POPS IN THE SOUTHWEST AND PUT IN SOME DRIZZLE IN THE NORTHEAST. THE NAM AND OBSERVATIONS TO THE NORTH SUPPORT THIS. INCREASED SKY COVER TO CLOUDY FOR OVERNIGHT. && .PREV DISCUSSION... /ISSUED 643 PM CDT MON APR 2 2012/ AVIATION...00Z KGRI TAF. MVFR CEILINGS WILL MOVE IN THIS THIS EVENING AT THE BEGINNING OF THE FORECAST ALONG WITH GUSTY NORTH NORTHWEST WIND BEHIND A COLD FRONT THAT PASSED THROUGH A FEW HOURS EARLIER. SOME SHORT RANGE MODELS INDICATE SOME ELEVATED INSTABILITY WILL HELP BRING SOME RAIN OVERNIGHT...BUT CONFIDENCE IS NOT HIGH AS MODELS DIFFER WILDLY WITH RAIN POSSIBILITIES. STRATUS SHOULD HANG AROUND FOR ESSENTIALLY THE ENTIRE FORECAST. PREV DISCUSSION... /ISSUED 346 PM CDT MON APR 2 2012/ SHORT TERM...TONIGHT AND TUESDAY. MAIN FORECAST CONCERN WILL BE CHANCE FOR SHOWERS AND THUNDERSTORMS. SURFACE ANALYSIS AND SURFACE OBSERVATIONS INDICATE A COLD FRONT ACROSS THE EASTERN PART OF THE FORECAST AREA THIS AFTERNOON. AHEAD OF THE COLD FRONT TEMPERATURES HAVE JUMPED AND ARE QUITE WARM. COOLER TEMPERATURES ARE BEHIND THE FRONT. SATELLITE SHOWS SOME STRATUS ACROSS THE FAR NORTHERN PART OF THE FORECAST AREA. THIS WAS SPREADING FURTHER SOUTH THIS MORNING...BUT HAS HELD OFF DURING THE AFTERNOON. WINDS HAVE FINALLY STARTED TO INCREASE TO THE WEST AND WILL CONTINUE TO INCREASE THIS AFTERNOON FOR THE FAR WEST. WILL LEAVE THE WIND ADVISORY AS IS. THE POSITION OF THE FRONT IS KEY THIS AFTERNOON FOR THUNDERSTORM DEVELOPMENT. MODELS HAVE THUNDERSTORMS DEVELOPING ALONG THE FRONT DURING THE LATE AFTERNOON AND EARLY EVENING. WITH THE CURRENT LOCATION OF THE FRONT EXPECT THUNDERSTORMS TO BE IN THE SOUTHEAST PART OF THE FORECAST AREA. THE HRRR KEEPS THE PRECIPITATION IN THE FAR SOUTHEAST THROUGH THE EVENING WHILE THE NAM AND GFS HAVE IT A BIT FURTHER TO THE NORTHWEST. THE BEST MUCAPES ARE IN THE FAR SOUTHEAST PART OF THE FORECAST AREA WITH THE OVER 1000J/KG CAPES FAR IN THE SOUTHEASTERN PART OF THE FORECAST AREA. LATER THIS EVENING AND OVERNIGHT AN UPPER LEVEL LOW DEVELOPING ON THE SOUTHERN HIGH PLAINS STARTS TO DRIFT TO THE NORTH AND PUSHES PRECIPITATION TO THE NORTH BEHIND THE FRONT. MOST OF THE PRECIPITATION SHOULD BE IN THE SOUTHERN PART OF THE FORECAST AREA. THE UPPER LEVEL LOW CONTINUES TO DRIFT THROUGH THE SOUTHERN HIGH PLAINS ON TUESDAY AND THE CHANCE FOR SHOWERS CONTINUES MAINLY IN THE SOUTH/SOUTHWEST. LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH PRECIPITATION CHANCES EARLY ON IN THE PERIOD. LOOKING AT THE TIME FRAME STARTING TUESDAY NIGHT AND CONTINUING THROUGH WEDNESDAY NIGHT...THE MAIN STORY LIES WITH THE IMPACT ACROSS THE REGION FROM A PASSING UPPER LEVEL LOW PRESSURE SYSTEM AND ASSOCIATED PRECIPITATION CHANCES. LATEST MODELS RUNS ARE IN PRETTY GOOD AGREEMENT AT THE START OF THE PERIOD...SHOWING THE LOW CENTERED OVER THE PANHANDLES OF TX/OK...BUT MORE VARIANCES START TO SHOW UP THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY. THE SYSTEM DOESNT MAKE A WHOLE LOT OF EASTWARD PROGRESS...WITH A RIDGE AXIS TO THE EAST EXTENDING FROM THE GULF COAST REGION UP INTO THE ERN DAKOTAS...AND BY WEDNESDAY EVENING LOOKS TO RANGE IN LOCATION FROM SC KS TO WRN OK. INCREASED LIFT OUT AHEAD OF THE LOW PRESSURE SYSTEM WILL HELP WITH THE NORTHWARD SPREAD OF PRECIPITATION FROM THE SRN PLAINS INTO THE CWA TUESDAY EVENING/OVERNIGHT...WHICH WILL CONTINUE ON INTO THE DAYTIME HOURS ON WEDNESDAY AS INCREASED LOW/MID LEVEL FRONTOGENETICAL ON THE NORTHERN SIDE OF THE LOW SHIFTS INTO THE CWA. DECIDED TO INSERT A MENTION OF ISOLATED THUNDER WED EVENING...WITH SOME OF THE MODELS/SREF PROBS SHOWING THE POTENTIAL LINGERING AROUND THE SOUTHEASTERN CORNER OF THE CWA. EXPECTING PLENTY OF CLOUD COVER AND GENERALLY N/NE WINDS AS THE MAIN SFC LOW SLIDES TO THE SOUTH OF THE CWA...WITH HIGHS TOPPING OUT IN THE LOW/MID 50S. MODELS ARE A LITTLE SLOWER THURSDAY EVENING/NIGHT PUSHING PRECIPITATION CHANCES EAST OF THE CWA AS THE UPPER LEVEL LOW MAKES ITS WAY TOWARD THE MO RIVER...AND PUSHED POPS BACK WEST TO INCLUDE ALL COUNTIES. UPPER LEVEL SHORTWAVE RIDGING BUILDING INTO THE PLAINS IN THE WAKE OF THIS LATEST SYSTEM IS EXPECTED TO KEEP THURSDAY AND THURSDAY NIGHT DRY. SEE A SLIGHT BUMP IN HIGHS BUT TEMPS REMAIN ON THE RELATIVELY COOL SIDE /COMPARED TO THE LAST FEW DAYS...BUT STILL NEAR OR ABOVE AVG/...WITH THE CWA REMAINING ON THE WRN/SRN FRINGE OF SFC HIGH PRESSURE OVER THE WRN GREAT LAKES...AND AM EXPECTING LOWER 60S. NEXT CHANCE FOR PRECIPITATION IS EXPECTED TO COME TO WESTERN PORTIONS OF THE CWA DURING THE DAY ON FRIDAY AND EXPAND FURTHER EAST FRIDAY NIGHT...AS ANOTHER SHORTWAVE TROUGH AXIS LOOKS TO SWING THROUGH THE NORTHERN/CENTRAL PLAINS. MODELS VARY SOME THROUGH THIS TIMEFRAME...WITH THE GFS SHOWING THIS ENERGY ASSOCIATED WITH AN ELONGATED LOW OVER WRN/CENTRAL CANADA...WHILE THE EC SHOWS ANY LOW LOCATED OFF THE PAC NW COAST. KEPT THE HIGHER POPS ACROSS THE NORTH WHERE THERE IS BETTER AGREEMENT BETWEEN THE MODELS...BUT POPS GO ALL THE WAY SOUTH TROUGH THE CWA WITH THE GFS CONTINUING TO SHOW MORE COVERAGE. THE MAIN INSTABILITY AXIS LOOKS TO SET UP JUST WEST OF THE CWA DURING THE DAY...AND PUSH THROUGH DURING THE OVERNIGHT HOURS...WITH MUCAPE VALUES UPWARDS OF 7-800 J/KG...SO THREAT OF SOME STRONG STORMS WILL REMAIN...BUT WILL CONTINUE TO KEEP AN EYE ON THE POTENTIAL FOR SEVERE STORMS. KEPT THE FORECAST FOR THE UPCOMING WEEKEND AND INTO MONDAY DRY...THOUGH THE GFS TRIES TO LINGER SOME POPS IN THE EAST EARLY ON SAT MORNING. AN ACCOMPANYING SURFACE COLD FRONT IS EXPECTED TO BE ON ITS WAY THROUGH THE CWA SATURDAY MORNING...BUT MODELS DO VARY SOME ON THE TIMING. EC IS ON THE QUICKER SIDE...WITH THE FRONT CLEARING THE CWA SAT MORNING...WHILE THE GFS WOULD BE MORE INTO THE AFTERNOON. LOOKS TO BE BREEZY DAY ON SATURDAY...WITH NORTHWEST WINDS PICKING UP BEHIND THE FRONT. MORE ZONAL/NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS FOR SUN/MON WITH A RIDGE SET UP OVER THE SRN/SWRN CONUS...WITH NO NOTABLE SYSTEM LOOKING TO PASS THROUGH. BEHIND THE SFC FRONT...HIGH PRESSURE BUILDS IN AND IS THE DOMINANT FEATURE ON SUNDAY...BRINGING A PLEASANT WITH LIGHT WINDS AND HIGHS TOPPING OUT IN THE LOWER/MID 60S. MONDAY COULD SEE AN INCREASE IN WINDS DEPENDING ON THE MODEL...BUT STILL EXPECTING ANOTHER NICE DAY WITH HIGHS SIMILAR TO SUNDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION/UPDATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
944 PM CDT MON APR 2 2012 .UPDATE... WINDS ALOFT AT THE KLNX PROFILER HAVE DROPPED TO 40 TO 45 KT SUPPORTING DECREASING SFC WIND SPEEDS. THE PRESSURE GRADIENT ACROSS NWRN NEB IS RELAXING. MERRIMAN PROFILER STILL RUNNING 30 TO 50 KTS ALOFT THOUGH. OVERALL IT LOOKS LIKE WINDS WILL STAY UP A FEW MORE HOURS AS THE STRATUS TRAPS MOMENTUM IN THE BOUNDARY LAYER. SO PORTIONS OF THE WIND ADVISORY HAVE BEEN EXTENDED UNTIL 06Z AND OTHERS HAVE BEEN CANCELLED. PREV DISCUSSION... /ISSUED 638 PM CDT MON APR 2 2012/ UPDATE... THE HIGH WIND THREAT HAS ENDED AS MIXING HEIGHTS APPEAR TO BE FALLING. WINDS AT THE MERRIMAN PROFILER HAVE FALLEN TO 45 KTS AND THE KLNX VAD WIND PROFILER INDICATES A DEEP LAYER OF 40 TO 50 KT WINDS SUPPORTING WIND ADVISORY CONDITIONS. SO THE HIGH WIND WARNING HAS BEEN CANCELLED FOR PARTS OF WESTERN NEBRASKA. PREV DISCUSSION... /ISSUED 607 PM CDT MON APR 2 2012/ UPDATE... AVIATION... MVFR CIGS ARE EXPECTED TO REMAIN FAIRLY WIDESPREAD OVERNIGHT ALONG AND EAST OF HIGHWAY 83 WITH LOCAL IFR AROUND KONL. TOWARD MORNING...IFR MAY DEVELOP FOR A PERIOD SOUTH OF I-80 AS A BAND OF SHOWERS LIFTS NORTH AND DISSIPATES. MVFR SHOULD CONTINUE ALONG AND SOUTH OF I-80 THROUGHOUT THE DAY TUESDAY WITH VFR DEVELOPING NORTH OF I-80. PREV DISCUSSION... /ISSUED 448 PM CDT MON APR 2 2012/ UPDATE... SFC LOW PRESSURE APPEARS TO BE TRACKING TOO CLOSE TO EASTERN PORTIONS OF NCNTL NEB FOR STRONG WINDS TO DEVELOP. SO THAT PORTION OF THE WIND ADZY HAS BEEN CANCELLED. NEITHER THE RUC NOR THE HRRR INDICATE 45 MPH GUST BECOMING WIDESPREAD. PREV DISCUSSION... /ISSUED 315 PM CDT MON APR 2 2012/ DISCUSSION... A DECISION MAY NEED TO BE MADE ON WHETHER TO CONTINUE THE WIND ADVISORY ALONG HWY 281. THE MODELS ARE TRACKING THE SFC LOW FAR ENOUGH WEST TO PERHAPS PREVENT STRONG WINDS FROM DEVELOPING IN THAT REGION. OTHERWISE THE HIGH WIND WARNING CAN CONTINUE OPERATING ACROSS PARTS OF WRN NEB. HIGH WINDS MIGHT DEVELOP EASTWARD UNTIL 00Z AS MERRIMAN PROFILER SHOWS 2 GATES OF 55KT AT 19Z. WITH CYCLOGENESIS DEVELOPING TONIGHT ACROSS TX AND THE MODELS INDICATING REDEVELOPMENT OF STRATUS ACROSS THE FCST AREA...WIND ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT ACROSS PARTS OF SWRN NEB. AN UPPER LEVEL LOW DEVELOPING ACROSS ERN NM/NW TEXAS TONIGHT IS EXPECTED TO SHOOT A BAND OF WARM AIR ADVECTION DRIVEN SHOWERS NORTHWARD INTO SRN NEB. THE MODELS INDICATE THIS BAND OF SHOWERS WILL FALL APART FAIRLY QUICKLY AS IT MOVES NORTH. A MORE SUBSTANTIAL BAND OF SHOWERS SHOULD DEVELOP TUESDAY NIGHT WHICH IS PROGGED TO SWEEP INTO PARTS OF WRN AND NCNTL NEB PRODUCING AROUND 1/2 TO 3/4 OF AN INCH OF RAIN ON WEDNESDAY. THE GFS APPEARS TO SUFFERING QPF FEEDBACK PROBLEMS. TIME HEIGHTS SHOW 20 UBARS OF LIFT EXTENDING UPWARD TO OVER 500 MB AND THE QPF LOOKS OVERDONE. A 4-WAY BLEND OF NAM...GEM...ECM AND GFS WAS USED AS A BASIS FOR QPF AND POPS WHICH SUGGESTED DEFINITE RAIN CHANCES WEDNESDAY. THE STORM SYSTEM SHOULD CLEAR THE FCST AREA LATE WEDNESDAY NIGHT WITH CLEARING SKIES ON THURSDAY. THEREAFTER A PERIOD OF WARM AIR ADVECTION DEVELOPS FRIDAY AHEAD OF A DEEP UPPER LEVEL TROF SITUATED ACROSS THE WRN U.S.. STRATUS AND SHOWERS ARE POSSIBLE EARLY FRIDAY MORNING. A STRONG DISTURBANCE WILL LIFT THROUGH THE NRN HIGH PLAINS FRIDAY AFTN AND FRIDAY NIGHT. TSTMS ARE POSSIBLE ACROSS NORTHERN PORTIONS OF THE FCST AREA AS THIS DISTURBANCE LIFT THROUGH THE PLAINS. A PV15 ANOMALY WILL BE OPERATING IN TANDEM WITH THE DISTURBANCE AND A DRYLINE BULGE SHOULD DEVELOP FOLLOWED BY A STRONG PACIFIC COLD FRONT. HIGH PRESSURE AND COOL WEATHER IS EXPECTED SATURDAY THROUGH MONDAY WITH HIGHS IN THE 50S TO LOWER 60S. AVIATION... WIND SPEEDS ARE EXPECTED TO DECREASE THIS EVENING...HOWEVER GUSTS ARE EXPECTED TO STAY AT OR ABOVE 25KTS THROUGH THE OVERNIGHT HOURS AND MUCH OF TUESDAY MORNING. LOCATIONS ACROSS SOUTHWEST INTO CENTRAL NEBRASKA /FROM KOGA TO KTIF TO KONL/ WILL SEE THE HIGHER WINDS PERSIST THE LONGEST...WITH GUSTS OVER 30KTS. MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE THIS EVENING LEADING TO FURTHER DEVELOPMENT OF STRATUS AND MVFR CEILINGS. THERE ARE MIXED SIGNALS ON THE HEIGHT OF THIS CLOUD LAYER. SO ALTHOUGH FAIRLY CONFIDENT ON STRATUS ACROSS THE AREA...DO HAVE A CONSIDERATE AMOUNT OF UNCERTAINTY ON THE CLOUD HEIGHT. NAM WOULD SAY IFR CEILINGS WHILE OTHER SOLUTIONS WOULD ACTUALLY RAISE THE CEILINGS TO ABOUT 5K FEET. AT THIS TIME...KEPT A STABLE FORECAST WITH CEILINGS AT BOTH KVTN AND KLBF AT 2500 FT THROUGH TUESDAY MORNING. && .LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ TUESDAY FOR NEZ056>058-069-070. WIND ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ TUESDAY FOR NEZ022- 023-035>038-059-071. && $$ SHORT TERM/EXTENDED...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
942 PM CDT MON APR 2 2012 .UPDATE... WINDS ALOFT AT THE KLNX PROFILER HAVE DROPPED TO 40 TO 45 KT SUPPORTING DECREASING SFC WIND SPEEDS. THE PRESSURE GRADIENT ACROSS NWRN NEB IS RELAXING. MERRIMAN PROFILER STILL RUNNING 30 TO 50 KTS ALOFT THOUGH. OVERALL IT LOOKS LIKE WINDS WILL STAY UP A FEW MORE HOURS AS THE STRATUS TRAPS MOMENTUM IN THE BOUNDARY LAYER. SO PORTIONS OF THE WIND ADVISORY HAVE BEEN EXTENDED UNTIL 06Z AND OTHERS HAVE BEEN CANCELLED. && .PREV DISCUSSION... /ISSUED 638 PM CDT MON APR 2 2012/ UPDATE... THE HIGH WIND THREAT HAS ENDED AS MIXING HEIGHTS APPEAR TO BE FALLING. WINDS AT THE MERRIMAN PROFILER HAVE FALLEN TO 45 KTS AND THE KLNX VAD WIND PROFILER INDICATES A DEEP LAYER OF 40 TO 50 KT WINDS SUPPORTING WIND ADVISORY CONDITIONS. SO THE HIGH WIND WARNING HAS BEEN CANCELLED FOR PARTS OF WESTERN NEBRASKA. PREV DISCUSSION... /ISSUED 607 PM CDT MON APR 2 2012/ UPDATE... AVIATION... MVFR CIGS ARE EXPECTED TO REMAIN FAIRLY WIDESPREAD OVERNIGHT ALONG AND EAST OF HIGHWAY 83 WITH LOCAL IFR AROUND KONL. TOWARD MORNING...IFR MAY DEVELOP FOR A PERIOD SOUTH OF I-80 AS A BAND OF SHOWERS LIFTS NORTH AND DISSIPATES. MVFR SHOULD CONTINUE ALONG AND SOUTH OF I-80 THROUGHOUT THE DAY TUESDAY WITH VFR DEVELOPING NORTH OF I-80. PREV DISCUSSION... /ISSUED 448 PM CDT MON APR 2 2012/ UPDATE... SFC LOW PRESSURE APPEARS TO BE TRACKING TOO CLOSE TO EASTERN PORTIONS OF NCNTL NEB FOR STRONG WINDS TO DEVELOP. SO THAT PORTION OF THE WIND ADZY HAS BEEN CANCELLED. NEITHER THE RUC NOR THE HRRR INDICATE 45 MPH GUST BECOMING WIDESPREAD. PREV DISCUSSION... /ISSUED 315 PM CDT MON APR 2 2012/ DISCUSSION... A DECISION MAY NEED TO BE MADE ON WHETHER TO CONTINUE THE WIND ADVISORY ALONG HWY 281. THE MODELS ARE TRACKING THE SFC LOW FAR ENOUGH WEST TO PERHAPS PREVENT STRONG WINDS FROM DEVELOPING IN THAT REGION. OTHERWISE THE HIGH WIND WARNING CAN CONTINUE OPERATING ACROSS PARTS OF WRN NEB. HIGH WINDS MIGHT DEVELOP EASTWARD UNTIL 00Z AS MERRIMAN PROFILER SHOWS 2 GATES OF 55KT AT 19Z. WITH CYCLOGENESIS DEVELOPING TONIGHT ACROSS TX AND THE MODELS INDICATING REDEVELOPMENT OF STRATUS ACROSS THE FCST AREA...WIND ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT ACROSS PARTS OF SWRN NEB. AN UPPER LEVEL LOW DEVELOPING ACROSS ERN NM/NW TEXAS TONIGHT IS EXPECTED TO SHOOT A BAND OF WARM AIR ADVECTION DRIVEN SHOWERS NORTHWARD INTO SRN NEB. THE MODELS INDICATE THIS BAND OF SHOWERS WILL FALL APART FAIRLY QUICKLY AS IT MOVES NORTH. A MORE SUBSTANTIAL BAND OF SHOWERS SHOULD DEVELOP TUESDAY NIGHT WHICH IS PROGGED TO SWEEP INTO PARTS OF WRN AND NCNTL NEB PRODUCING AROUND 1/2 TO 3/4 OF AN INCH OF RAIN ON WEDNESDAY. THE GFS APPEARS TO SUFFERING QPF FEEDBACK PROBLEMS. TIME HEIGHTS SHOW 20 UBARS OF LIFT EXTENDING UPWARD TO OVER 500 MB AND THE QPF LOOKS OVERDONE. A 4-WAY BLEND OF NAM...GEM...ECM AND GFS WAS USED AS A BASIS FOR QPF AND POPS WHICH SUGGESTED DEFINITE RAIN CHANCES WEDNESDAY. THE STORM SYSTEM SHOULD CLEAR THE FCST AREA LATE WEDNESDAY NIGHT WITH CLEARING SKIES ON THURSDAY. THEREAFTER A PERIOD OF WARM AIR ADVECTION DEVELOPS FRIDAY AHEAD OF A DEEP UPPER LEVEL TROF SITUATED ACROSS THE WRN U.S.. STRATUS AND SHOWERS ARE POSSIBLE EARLY FRIDAY MORNING. A STRONG DISTURBANCE WILL LIFT THROUGH THE NRN HIGH PLAINS FRIDAY AFTN AND FRIDAY NIGHT. TSTMS ARE POSSIBLE ACROSS NORTHERN PORTIONS OF THE FCST AREA AS THIS DISTURBANCE LIFT THROUGH THE PLAINS. A PV15 ANOMALY WILL BE OPERATING IN TANDEM WITH THE DISTURBANCE AND A DRYLINE BULGE SHOULD DEVELOP FOLLOWED BY A STRONG PACIFIC COLD FRONT. HIGH PRESSURE AND COOL WEATHER IS EXPECTED SATURDAY THROUGH MONDAY WITH HIGHS IN THE 50S TO LOWER 60S. AVIATION... WIND SPEEDS ARE EXPECTED TO DECREASE THIS EVENING...HOWEVER GUSTS ARE EXPECTED TO STAY AT OR ABOVE 25KTS THROUGH THE OVERNIGHT HOURS AND MUCH OF TUESDAY MORNING. LOCATIONS ACROSS SOUTHWEST INTO CENTRAL NEBRASKA /FROM KOGA TO KTIF TO KONL/ WILL SEE THE HIGHER WINDS PERSIST THE LONGEST...WITH GUSTS OVER 30KTS. MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE THIS EVENING LEADING TO FURTHER DEVELOPMENT OF STRATUS AND MVFR CEILINGS. THERE ARE MIXED SIGNALS ON THE HEIGHT OF THIS CLOUD LAYER. SO ALTHOUGH FAIRLY CONFIDENT ON STRATUS ACROSS THE AREA...DO HAVE A CONSIDERATE AMOUNT OF UNCERTAINTY ON THE CLOUD HEIGHT. NAM WOULD SAY IFR CEILINGS WHILE OTHER SOLUTIONS WOULD ACTUALLY RAISE THE CEILINGS TO ABOUT 5K FEET. AT THIS TIME...KEPT A STABLE FORECAST WITH CEILINGS AT BOTH KVTN AND KLBF AT 2500 FT THROUGH TUESDAY MORNING. && .LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ TUESDAY FOR NEZ056>058- 069-070. WIND ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ TUESDAY FOR NEZ022- 023-035>038-059-071. && $$ SHORT TERM/EXTENDED...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
927 PM CDT MON APR 2 2012 .DISCUSSION... UPDATED THE FORECAST FOR SKY...POP/WEATHER...AND TEMPERATURE TRENDS THIS EVENING. OVERCAST STRATUS DECK HAS ENCROACHED INTO NORTHWEST CWA...AND RUC/NAM/HRRR PROGS INDICATE IT WILL OVERSPREAD MUCH OF EASTERN NEB INTO WESTERN IA THROUGH THE EVENING AND OVERNIGHT HOURS...WITH CLOUDS LINGERING THROUGH MUCH OR ALL OF TOMORROW AS WELL. HAVE BUMPED CLOUDS TO OVERCAST/CLOUDY COVERAGE THROUGH AT LEAST MIDDAY TOMORROW. PRECIP HAS REMAINED MAINLY SOUTH AND WEST OF THE CWA...WITH JUST A FEW SHOWERS POPPING UP ALONG AND BEHIND THE FRONT. HAVE UPDATED THE FORECAST TO MENTION JUST ISOLATED SHOWERS FOR THE NEXT HOUR OR SO...WITH NO MEASURABLE PRECIP FOR THE REST OF THE NIGHT. ALSO REMOVED MEASURABLE PRECIP FROM THE NORTHWEST CWA AND ADDED DRIZZLE...AS KLBF RADAR HAS A DRIZZLE APPEARANCE WITH LIGHT PRECIP ON THE KONL OB. FINALLY...WITH TEMPERATURES DROPPING ABRUPTLY BEHIND THE FRONT...HAVE UPDATED THE TEMPERATURE TREND FOR A SHARP DROPOFF IMMEDIATELY BEHIND THE FRONT...WITH A SLOWER DROPOFF THROUGH THE REST OF THE NIGHT AS CLOUDS INCREASE AND GUSTY WINDS CONTINUE. MAYES && .PREV DISCUSSION... /ISSUED 630 PM CDT MON APR 2 2012/ AVIATION... 00Z TAFS FOR KOMA...KLNK...AND KOFK. COLD FRONT IS BRINGING A SIGNIFICANT CHANGE AT ALL TAF SITES. FRONT HAD ALREADY REACHED KOFK...AND WILL REACH KLNK/KOMA WITHIN A COUPLE OF HOURS. MVFR TO IFR CIGS LAG JUST BEHIND THE FRONT...WITH KOFK LIKELY TO BE RIGHT AROUND 1KFT BY 02Z...AND MVFR STRATUS MOVING INTO KOMA/KLNK BY 06-08Z. MODELS INDICATE STRATUS WILL LINGER THROUGH TOMORROW...WITH CIGS LIKELY LIFTING ABOVE MVFR IN THE AFTERNOON WITH SOME DIURNAL MIXING. WINDS WILL VEER FROM NORTHWEST TO NORTHEAST THROUGH THE DAY...BUT WILL REMAIN GUSTY THROUGH THE DAY AT ALL SITES. DID KEEP RAIN/CB OUT OF KOMA/KLNK...AS FRONT IS MOVING THROUGH THOSE SITES AND ANY THUNDERSTORMS WOULD BE MORE LIKELY TO OCCUR TO THE EAST...THOUGH DO HAVE SCT CU THIS EVENING OVER THOSE SITES. MAYES PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... THE SHORT TERM CONCERNS WILL BE THE POTENTIAL FOR THUNDERSTORMS AND SEVERE WEATHER AND IF A WIND ADVISORY WILL BE NEEDED. AT 20Z...THE COLD FRONT HAD FINALLY MADE IT INTO NORFOLK AND THEIR TEMPERATURES WERE BEGINNING TO FALL. AHEAD OF THE FRONT...TEMPERATURES TOPPED OUT IN THE 80S TO LOWER 90S. THE LOW CLOUDS HAD MADE IT INTO THE THE ONEILL AREA AND TEMPERATURES WERE ONLY IN THE 50S. WINDS IN THE WEST CENTRAL PART OF NEBRASKA WERE QUITE STRONG WITH GUSTS IN THE 40 TO 50 MPH IN SPOTS. TONIGHT...THE SURFACE COLD FRONT WILL BE MOVING ACROSS THE REST OF EASTERN NEBRASKA AND SOUTHWEST IOWA. THE HIGHER UPPER 50S AND LOWER 60S DEGREE DEWPOINTS AT 20Z EXTENDED FROM BEATRICE TO OMAHA AND THESE WILL SHIFT EASTWARD WITH TIME. THE 4KM WRF HAD THUNDERSTORMS ALONG THE FRONT...WHILE THE 18Z NAM WAS DRY...THE LATEST RUC HAD SOME STORMS DEVELOPING TOWARD FAIRBURY AND THE GFS HAD AN AREA SIMILAR TO THE 4KM WRF...BUT SHIFTED FARTHER SOUTHEAST AND MAINLY ALONG AND SOUTH OF I80. THERE IS THE POTENTIAL FOR THUNDERSTORMS THIS EVENING AHEAD OF AND ALONG THE FRONT AND WILL MAINTAIN ISOLATED TO SCATTERED THUNDERSTORM CHANCES MAINLY ALONG AND SOUTH OF I80. THE ATMOSPHERE HAS GOOD INSTABILITY AND STEEP LAPSE RATES TO WORK WITH...HOWEVER THE SHEAR PARAMETERS DO NOT APPEAR AS FAVORABLE IN THIS AREA. SPC HAS A SLIGHT RISK AND THE SLIGHT RISK APPEARS WARRANTED BASED ON CONDITIONAL FACTORS AS SHOULD THUNDERSTORMS GET GOING THEY COULD CONTAIN SOME HAIL AND DAMAGING WINDS. BEHIND THE FRONT...ESPECIALLY ACROSS NORTHEAST NEBRASKA THE WINDS WILL BE STRONG. AT THIS TIME WILL HAVE WINDY CONDITIONS AT 20 TO 30 MPH WITH GUSTS TO 45...BUT HAVE NOT GONE WITH A WIND ADVISORY AT THIS TIME. BEHIND THE FRONT...WITH THE LOW CLOUDS THERE MAY BE SOME SHOWERS IN NORTHEAST NEBRASKA AND SOME OF THESE MAY LINGER INTO TUESDAY. THE SOUTHERN ENERGY WITH THIS STORM SYSTEM WILL CLOSE OFF AND LIFT NORTH. THIS WILL RETURN THE CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY AND WEDNESDAY NIGHT AND THEN MOVE OUT THURSDAY. THURSDAY NIGHT THROUGH MONDAY....THE STORM SYSTEM THAT WILL AFFECT US FOR MUCH OF THE WEEK WILL BE OVER SOUTHERN MISSOURI AT THE START OF THE EXTENDED WITH DRY CONDITIONS...SOUTHEAST BREEZES AND COMFORTABLE TEMPERATURES IN THE 60S FRIDAY. FRIDAY NIGHT...THE TROF OVER THE PACIFIC NORTHWEST WILL PUSH FAR ENOUGH EASTWARD TO PUSH TO FRONT INTO PARTS OF EASTERN NEBRASKA BY 12Z SATURDAY. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF AND ALONG THE COLD FRONT FRIDAY NIGHT AND SATURDAY. AS THIS SYSTEM MOVES OUT OF THE AREA...MID LEVEL RIDGING BUILDS IN AND DRY WEATHER AND MORE SEASONABLE WEATHER IS FORECAST FOR SATURDAY AND SUNDAY. ZAPOTOCNY && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
643 PM CDT MON APR 2 2012 .AVIATION...00Z KGRI TAF. MVFR CEILINGS WILL MOVE IN THIS THIS EVENING AT THE BEGINNING OF THE FORECAST ALONG WITH GUSTY NORTH NORTHWEST WIND BEHIND A COLD FRONT THAT PASSED THROUGH A FEW HOURS EARLIER. SOME SHORT RANGE MODELS INDICATE SOME ELEVATED INSTABILITY WILL HELP BRING SOME RAIN OVERNIGHT...BUT CONFIDENCE IS NOT HIGH AS MODELS DIFFER WILDLY WITH RAIN POSSIBILITIES. STRATUS SHOULD HANG AROUND FOR ESSENTIALLY THE ENTIRE FORECAST. && .PREV DISCUSSION... /ISSUED 346 PM CDT MON APR 2 2012/ SHORT TERM...TONIGHT AND TUESDAY. MAIN FORECAST CONCERN WILL BE CHANCE FOR SHOWERS AND THUNDERSTORMS. SURFACE ANALYSIS AND SURFACE OBSERVATIONS INDICATE A COLD FRONT ACROSS THE EASTERN PART OF THE FORECAST AREA THIS AFTERNOON. AHEAD OF THE COLD FRONT TEMPERATURES HAVE JUMPED AND ARE QUITE WARM. COOLER TEMPERATURES ARE BEHIND THE FRONT. SATELLITE SHOWS SOME STRATUS ACROSS THE FAR NORTHERN PART OF THE FORECAST AREA. THIS WAS SPREADING FURTHER SOUTH THIS MORNING...BUT HAS HELD OFF DURING THE AFTERNOON. WINDS HAVE FINALLY STARTED TO INCREASE TO THE WEST AND WILL CONTINUE TO INCREASE THIS AFTERNOON FOR THE FAR WEST. WILL LEAVE THE WIND ADVISORY AS IS. THE POSITION OF THE FRONT IS KEY THIS AFTERNOON FOR THUNDERSTORM DEVELOPMENT. MODELS HAVE THUNDERSTORMS DEVELOPING ALONG THE FRONT DURING THE LATE AFTERNOON AND EARLY EVENING. WITH THE CURRENT LOCATION OF THE FRONT EXPECT THUNDERSTORMS TO BE IN THE SOUTHEAST PART OF THE FORECAST AREA. THE HRRR KEEPS THE PRECIPITATION IN THE FAR SOUTHEAST THROUGH THE EVENING WHILE THE NAM AND GFS HAVE IT A BIT FURTHER TO THE NORTHWEST. THE BEST MUCAPES ARE IN THE FAR SOUTHEAST PART OF THE FORECAST AREA WITH THE OVER 1000J/KG CAPES FAR IN THE SOUTHEASTERN PART OF THE FORECAST AREA. LATER THIS EVENING AND OVERNIGHT AN UPPER LEVEL LOW DEVELOPING ON THE SOUTHERN HIGH PLAINS STARTS TO DRIFT TO THE NORTH AND PUSHES PRECIPITATION TO THE NORTH BEHIND THE FRONT. MOST OF THE PRECIPITATION SHOULD BE IN THE SOUTHERN PART OF THE FORECAST AREA. THE UPPER LEVEL LOW CONTINUES TO DRIFT THROUGH THE SOUTHERN HIGH PLAINS ON TUESDAY AND THE CHANCE FOR SHOWERS CONTINUES MAINLY IN THE SOUTH/SOUTHWEST. LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH PRECIPITATION CHANCES EARLY ON IN THE PERIOD. LOOKING AT THE TIME FRAME STARTING TUESDAY NIGHT AND CONTINUING THROUGH WEDNESDAY NIGHT...THE MAIN STORY LIES WITH THE IMPACT ACROSS THE REGION FROM A PASSING UPPER LEVEL LOW PRESSURE SYSTEM AND ASSOCIATED PRECIPITATION CHANCES. LATEST MODELS RUNS ARE IN PRETTY GOOD AGREEMENT AT THE START OF THE PERIOD...SHOWING THE LOW CENTERED OVER THE PANHANDLES OF TX/OK...BUT MORE VARIANCES START TO SHOW UP THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY. THE SYSTEM DOESNT MAKE A WHOLE LOT OF EASTWARD PROGRESS...WITH A RIDGE AXIS TO THE EAST EXTENDING FROM THE GULF COAST REGION UP INTO THE ERN DAKOTAS...AND BY WEDNESDAY EVENING LOOKS TO RANGE IN LOCATION FROM SC KS TO WRN OK. INCREASED LIFT OUT AHEAD OF THE LOW PRESSURE SYSTEM WILL HELP WITH THE NORTHWARD SPREAD OF PRECIPITATION FROM THE SRN PLAINS INTO THE CWA TUESDAY EVENING/OVERNIGHT...WHICH WILL CONTINUE ON INTO THE DAYTIME HOURS ON WEDNESDAY AS INCREASED LOW/MID LEVEL FRONTOGENETICAL ON THE NORTHERN SIDE OF THE LOW SHIFTS INTO THE CWA. DECIDED TO INSERT A MENTION OF ISOLATED THUNDER WED EVENING...WITH SOME OF THE MODELS/SREF PROBS SHOWING THE POTENTIAL LINGERING AROUND THE SOUTHEASTERN CORNER OF THE CWA. EXPECTING PLENTY OF CLOUD COVER AND GENERALLY N/NE WINDS AS THE MAIN SFC LOW SLIDES TO THE SOUTH OF THE CWA...WITH HIGHS TOPPING OUT IN THE LOW/MID 50S. MODELS ARE A LITTLE SLOWER THURSDAY EVENING/NIGHT PUSHING PRECIPITATION CHANCES EAST OF THE CWA AS THE UPPER LEVEL LOW MAKES ITS WAY TOWARD THE MO RIVER...AND PUSHED POPS BACK WEST TO INCLUDE ALL COUNTIES. UPPER LEVEL SHORTWAVE RIDGING BUILDING INTO THE PLAINS IN THE WAKE OF THIS LATEST SYSTEM IS EXPECTED TO KEEP THURSDAY AND THURSDAY NIGHT DRY. SEE A SLIGHT BUMP IN HIGHS BUT TEMPS REMAIN ON THE RELATIVELY COOL SIDE /COMPARED TO THE LAST FEW DAYS...BUT STILL NEAR OR ABOVE AVG/...WITH THE CWA REMAINING ON THE WRN/SRN FRINGE OF SFC HIGH PRESSURE OVER THE WRN GREAT LAKES...AND AM EXPECTING LOWER 60S. NEXT CHANCE FOR PRECIPITATION IS EXPECTED TO COME TO WESTERN PORTIONS OF THE CWA DURING THE DAY ON FRIDAY AND EXPAND FURTHER EAST FRIDAY NIGHT...AS ANOTHER SHORTWAVE TROUGH AXIS LOOKS TO SWING THROUGH THE NORTHERN/CENTRAL PLAINS. MODELS VARY SOME THROUGH THIS TIMEFRAME...WITH THE GFS SHOWING THIS ENERGY ASSOCIATED WITH AN ELONGATED LOW OVER WRN/CENTRAL CANADA...WHILE THE EC SHOWS ANY LOW LOCATED OFF THE PAC NW COAST. KEPT THE HIGHER POPS ACROSS THE NORTH WHERE THERE IS BETTER AGREEMENT BETWEEN THE MODELS...BUT POPS GO ALL THE WAY SOUTH TROUGH THE CWA WITH THE GFS CONTINUING TO SHOW MORE COVERAGE. THE MAIN INSTABILITY AXIS LOOKS TO SET UP JUST WEST OF THE CWA DURING THE DAY...AND PUSH THROUGH DURING THE OVERNIGHT HOURS...WITH MUCAPE VALUES UPWARDS OF 7-800 J/KG...SO THREAT OF SOME STRONG STORMS WILL REMAIN...BUT WILL CONTINUE TO KEEP AN EYE ON THE POTENTIAL FOR SEVERE STORMS. KEPT THE FORECAST FOR THE UPCOMING WEEKEND AND INTO MONDAY DRY...THOUGH THE GFS TRIES TO LINGER SOME POPS IN THE EAST EARLY ON SAT MORNING. AN ACCOMPANYING SURFACE COLD FRONT IS EXPECTED TO BE ON ITS WAY THROUGH THE CWA SATURDAY MORNING...BUT MODELS DO VARY SOME ON THE TIMING. EC IS ON THE QUICKER SIDE...WITH THE FRONT CLEARING THE CWA SAT MORNING...WHILE THE GFS WOULD BE MORE INTO THE AFTERNOON. LOOKS TO BE BREEZY DAY ON SATURDAY...WITH NORTHWEST WINDS PICKING UP BEHIND THE FRONT. MORE ZONAL/NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS FOR SUN/MON WITH A RIDGE SET UP OVER THE SRN/SWRN CONUS...WITH NO NOTABLE SYSTEM LOOKING TO PASS THROUGH. BEHIND THE SFC FRONT...HIGH PRESSURE BUILDS IN AND IS THE DOMINANT FEATURE ON SUNDAY...BRINGING A PLEASANT WITH LIGHT WINDS AND HIGHS TOPPING OUT IN THE LOWER/MID 60S. MONDAY COULD SEE AN INCREASE IN WINDS DEPENDING ON THE MODEL...BUT STILL EXPECTING ANOTHER NICE DAY WITH HIGHS SIMILAR TO SUNDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ039-046-060- 061-072-073-082-083. KS...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR KSZ005-017. && $$ AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
638 PM CDT MON APR 2 2012 .UPDATE... THE HIGH WIND THREAT HAS ENDED AS MIXING HEIGHTS APPEAR TO BE FALLING. WINDS AT THE MERRIMAN PROFILER HAVE FALLEN TO 45 KTS AND THE KLNX VAD WIND PROFILER INDICATES A DEEP LAYER OF 40 TO 50 KT WINDS SUPPORTING WIND ADVISORY CONDITIONS. SO THE HIGH WIND WARNING HAS BEEN CANCELLED FOR PARTS OF WESTERN NEBRASKA. && .PREV DISCUSSION... /ISSUED 607 PM CDT MON APR 2 2012/ UPDATE... AVIATION... MVFR CIGS ARE EXPECTED TO REMAIN FAIRLY WIDESPREAD OVERNIGHT ALONG AND EAST OF HIGHWAY 83 WITH LOCAL IFR AROUND KONL. TOWARD MORNING...IFR MAY DEVELOP FOR A PERIOD SOUTH OF I-80 AS A BAND OF SHOWERS LIFTS NORTH AND DISSIPATES. MVFR SHOULD CONTINUE ALONG AND SOUTH OF I-80 THROUGHOUT THE DAY TUESDAY WITH VFR DEVELOPING NORTH OF I-80. PREV DISCUSSION... /ISSUED 448 PM CDT MON APR 2 2012/ UPDATE... SFC LOW PRESSURE APPEARS TO BE TRACKING TOO CLOSE TO EASTERN PORTIONS OF NCNTL NEB FOR STRONG WINDS TO DEVELOP. SO THAT PORTION OF THE WIND ADZY HAS BEEN CANCELLED. NEITHER THE RUC NOR THE HRRR INDICATE 45 MPH GUST BECOMING WIDESPREAD. PREV DISCUSSION... /ISSUED 315 PM CDT MON APR 2 2012/ DISCUSSION... A DECISION MAY NEED TO BE MADE ON WHETHER TO CONTINUE THE WIND ADVISORY ALONG HWY 281. THE MODELS ARE TRACKING THE SFC LOW FAR ENOUGH WEST TO PERHAPS PREVENT STRONG WINDS FROM DEVELOPING IN THAT REGION. OTHERWISE THE HIGH WIND WARNING CAN CONTINUE OPERATING ACROSS PARTS OF WRN NEB. HIGH WINDS MIGHT DEVELOP EASTWARD UNTIL 00Z AS MERRIMAN PROFILER SHOWS 2 GATES OF 55KT AT 19Z. WITH CYCLOGENESIS DEVELOPING TONIGHT ACROSS TX AND THE MODELS INDICATING REDEVELOPMENT OF STRATUS ACROSS THE FCST AREA...WIND ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT ACROSS PARTS OF SWRN NEB. AN UPPER LEVEL LOW DEVELOPING ACROSS ERN NM/NW TEXAS TONIGHT IS EXPECTED TO SHOOT A BAND OF WARM AIR ADVECTION DRIVEN SHOWERS NORTHWARD INTO SRN NEB. THE MODELS INDICATE THIS BAND OF SHOWERS WILL FALL APART FAIRLY QUICKLY AS IT MOVES NORTH. A MORE SUBSTANTIAL BAND OF SHOWERS SHOULD DEVELOP TUESDAY NIGHT WHICH IS PROGGED TO SWEEP INTO PARTS OF WRN AND NCNTL NEB PRODUCING AROUND 1/2 TO 3/4 OF AN INCH OF RAIN ON WEDNESDAY. THE GFS APPEARS TO SUFFERING QPF FEEDBACK PROBLEMS. TIME HEIGHTS SHOW 20 UBARS OF LIFT EXTENDING UPWARD TO OVER 500 MB AND THE QPF LOOKS OVERDONE. A 4-WAY BLEND OF NAM...GEM...ECM AND GFS WAS USED AS A BASIS FOR QPF AND POPS WHICH SUGGESTED DEFINITE RAIN CHANCES WEDNESDAY. THE STORM SYSTEM SHOULD CLEAR THE FCST AREA LATE WEDNESDAY NIGHT WITH CLEARING SKIES ON THURSDAY. THEREAFTER A PERIOD OF WARM AIR ADVECTION DEVELOPS FRIDAY AHEAD OF A DEEP UPPER LEVEL TROF SITUATED ACROSS THE WRN U.S.. STRATUS AND SHOWERS ARE POSSIBLE EARLY FRIDAY MORNING. A STRONG DISTURBANCE WILL LIFT THROUGH THE NRN HIGH PLAINS FRIDAY AFTN AND FRIDAY NIGHT. TSTMS ARE POSSIBLE ACROSS NORTHERN PORTIONS OF THE FCST AREA AS THIS DISTURBANCE LIFT THROUGH THE PLAINS. A PV15 ANOMALY WILL BE OPERATING IN TANDEM WITH THE DISTURBANCE AND A DRYLINE BULGE SHOULD DEVELOP FOLLOWED BY A STRONG PACIFIC COLD FRONT. HIGH PRESSURE AND COOL WEATHER IS EXPECTED SATURDAY THROUGH MONDAY WITH HIGHS IN THE 50S TO LOWER 60S. AVIATION... WIND SPEEDS ARE EXPECTED TO DECREASE THIS EVENING...HOWEVER GUSTS ARE EXPECTED TO STAY AT OR ABOVE 25KTS THROUGH THE OVERNIGHT HOURS AND MUCH OF TUESDAY MORNING. LOCATIONS ACROSS SOUTHWEST INTO CENTRAL NEBRASKA /FROM KOGA TO KTIF TO KONL/ WILL SEE THE HIGHER WINDS PERSIST THE LONGEST...WITH GUSTS OVER 30KTS. MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE THIS EVENING LEADING TO FURTHER DEVELOPMENT OF STRATUS AND MVFR CEILINGS. THERE ARE MIXED SIGNALS ON THE HEIGHT OF THIS CLOUD LAYER. SO ALTHOUGH FAIRLY CONFIDENT ON STRATUS ACROSS THE AREA...DO HAVE A CONSIDERATE AMOUNT OF UNCERTAINTY ON THE CLOUD HEIGHT. NAM WOULD SAY IFR CEILINGS WHILE OTHER SOLUTIONS WOULD ACTUALLY RAISE THE CEILINGS TO ABOUT 5K FEET. AT THIS TIME...KEPT A STABLE FORECAST WITH CEILINGS AT BOTH KVTN AND KLBF AT 2500 FT THROUGH TUESDAY MORNING. && .LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ TUESDAY FOR NEZ056>058-069-070. WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR NEZ004>006-008-009-024>027-036>038-059-094. WIND ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ TUESDAY FOR NEZ022- 023-035-071. && $$ SHORT TERM/EXTENDED...CDC AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
630 PM CDT MON APR 2 2012 .AVIATION... 00Z TAFS FOR KOMA...KLNK...AND KOFK. COLD FRONT IS BRINGING A SIGNIFICANT CHANGE AT ALL TAF SITES. FRONT HAD ALREADY REACHED KOFK...AND WILL REACH KLNK/KOMA WITHIN A COUPLE OF HOURS. MVFR TO IFR CIGS LAG JUST BEHIND THE FRONT...WITH KOFK LIKELY TO BE RIGHT AROUND 1KFT BY 02Z...AND MVFR STRATUS MOVING INTO KOMA/KLNK BY 06-08Z. MODELS INDICATE STRATUS WILL LINGER THROUGH TOMORROW...WITH CIGS LIKELY LIFTING ABOVE MVFR IN THE AFTERNOON WITH SOME DIURNAL MIXING. WINDS WILL VEER FROM NORTHWEST TO NORTHEAST THROUGH THE DAY...BUT WILL REMAIN GUSTY THROUGH THE DAY AT ALL SITES. DID KEEP RAIN/CB OUT OF KOMA/KLNK...AS FRONT IS MOVING THROUGH THOSE SITES AND ANY THUNDERSTORMS WOULD BE MORE LIKELY TO OCCUR TO THE EAST...THOUGH DO HAVE SCT CU THIS EVENING OVER THOSE SITES. MAYES && .PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... THE SHORT TERM CONCERNS WILL BE THE POTENTIAL FOR THUNDERSTORMS AND SEVERE WEATHER AND IF A WIND ADVISORY WILL BE NEEDED. AT 20Z...THE COLD FRONT HAD FINALLY MADE IT INTO NORFOLK AND THEIR TEMPERATURES WERE BEGINNING TO FALL. AHEAD OF THE FRONT...TEMPERATURES TOPPED OUT IN THE 80S TO LOWER 90S. THE LOW CLOUDS HAD MADE IT INTO THE THE ONEILL AREA AND TEMPERATURES WERE ONLY IN THE 50S. WINDS IN THE WEST CENTRAL PART OF NEBRASKA WERE QUITE STRONG WITH GUSTS IN THE 40 TO 50 MPH IN SPOTS. TONIGHT...THE SURFACE COLD FRONT WILL BE MOVING ACROSS THE REST OF EASTERN NEBRASKA AND SOUTHWEST IOWA. THE HIGHER UPPER 50S AND LOWER 60S DEGREE DEWPOINTS AT 20Z EXTENDED FROM BEATRICE TO OMAHA AND THESE WILL SHIFT EASTWARD WITH TIME. THE 4KM WRF HAD THUNDERSTORMS ALONG THE FRONT...WHILE THE 18Z NAM WAS DRY...THE LATEST RUC HAD SOME STORMS DEVELOPING TOWARD FAIRBURY AND THE GFS HAD AN AREA SIMILAR TO THE 4KM WRF...BUT SHIFTED FARTHER SOUTHEAST AND MAINLY ALONG AND SOUTH OF I80. THERE IS THE POTENTIAL FOR THUNDERSTORMS THIS EVENING AHEAD OF AND ALONG THE FRONT AND WILL MAINTAIN ISOLATED TO SCATTERED THUNDERSTORM CHANCES MAINLY ALONG AND SOUTH OF I80. THE ATMOSPHERE HAS GOOD INSTABILITY AND STEEP LAPSE RATES TO WORK WITH...HOWEVER THE SHEAR PARAMETERS DO NOT APPEAR AS FAVORABLE IN THIS AREA. SPC HAS A SLIGHT RISK AND THE SLIGHT RISK APPEARS WARRANTED BASED ON CONDITIONAL FACTORS AS SHOULD THUNDERSTORMS GET GOING THEY COULD CONTAIN SOME HAIL AND DAMAGING WINDS. BEHIND THE FRONT...ESPECIALLY ACROSS NORTHEAST NEBRASKA THE WINDS WILL BE STRONG. AT THIS TIME WILL HAVE WINDY CONDITIONS AT 20 TO 30 MPH WITH GUSTS TO 45...BUT HAVE NOT GONE WITH A WIND ADVISORY AT THIS TIME. BEHIND THE FRONT...WITH THE LOW CLOUDS THERE MAY BE SOME SHOWERS IN NORTHEAST NEBRASKA AND SOME OF THESE MAY LINGER INTO TUESDAY. THE SOUTHERN ENERGY WITH THIS STORM SYSTEM WILL CLOSE OFF AND LIFT NORTH. THIS WILL RETURN THE CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY AND WEDNESDAY NIGHT AND THEN MOVE OUT THURSDAY. THURSDAY NIGHT THROUGH MONDAY....THE STORM SYSTEM THAT WILL AFFECT US FOR MUCH OF THE WEEK WILL BE OVER SOUTHERN MISSOURI AT THE START OF THE EXTENDED WITH DRY CONDITIONS...SOUTHEAST BREEZES AND COMFORTABLE TEMPERATURES IN THE 60S FRIDAY. FRIDAY NIGHT...THE TROF OVER THE PACIFIC NORTHWEST WILL PUSH FAR ENOUGH EASTWARD TO PUSH TO FRONT INTO PARTS OF EASTERN NEBRASKA BY 12Z SATURDAY. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF AND ALONG THE COLD FRONT FRIDAY NIGHT AND SATURDAY. AS THIS SYSTEM MOVES OUT OF THE AREA...MID LEVEL RIDGING BUILDS IN AND DRY WEATHER AND MORE SEASONABLE WEATHER IS FORECAST FOR SATURDAY AND SUNDAY. ZAPOTOCNY && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
607 PM CDT MON APR 2 2012 .UPDATE... .AVIATION... MVFR CIGS ARE EXPECTED TO REMAIN FAIRLY WIDESPREAD OVERNIGHT ALONG AND EAST OF HIGHWAY 83 WITH LOCAL IFR AROUND KONL. TOWARD MORNING...IFR MAY DEVELOP FOR A PERIOD SOUTH OF I-80 AS A BAND OF SHOWERS LIFTS NORTH AND DISSIPATES. MVFR SHOULD CONTINUE ALONG AND SOUTH OF I-80 THROUGHOUT THE DAY TUESDAY WITH VFR DEVELOPING NORTH OF I-80. && .PREV DISCUSSION... /ISSUED 448 PM CDT MON APR 2 2012/ UPDATE... SFC LOW PRESSURE APPEARS TO BE TRACKING TOO CLOSE TO EASTERN PORTIONS OF NCNTL NEB FOR STRONG WINDS TO DEVELOP. SO THAT PORTION OF THE WIND ADZY HAS BEEN CANCELLED. NEITHER THE RUC NOR THE HRRR INDICATE 45 MPH GUST BECOMING WIDESPREAD. PREV DISCUSSION... /ISSUED 315 PM CDT MON APR 2 2012/ DISCUSSION... A DECISION MAY NEED TO BE MADE ON WHETHER TO CONTINUE THE WIND ADVISORY ALONG HWY 281. THE MODELS ARE TRACKING THE SFC LOW FAR ENOUGH WEST TO PERHAPS PREVENT STRONG WINDS FROM DEVELOPING IN THAT REGION. OTHERWISE THE HIGH WIND WARNING CAN CONTINUE OPERATING ACROSS PARTS OF WRN NEB. HIGH WINDS MIGHT DEVELOP EASTWARD UNTIL 00Z AS MERRIMAN PROFILER SHOWS 2 GATES OF 55KT AT 19Z. WITH CYCLOGENESIS DEVELOPING TONIGHT ACROSS TX AND THE MODELS INDICATING REDEVELOPMENT OF STRATUS ACROSS THE FCST AREA...WIND ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT ACROSS PARTS OF SWRN NEB. AN UPPER LEVEL LOW DEVELOPING ACROSS ERN NM/NW TEXAS TONIGHT IS EXPECTED TO SHOOT A BAND OF WARM AIR ADVECTION DRIVEN SHOWERS NORTHWARD INTO SRN NEB. THE MODELS INDICATE THIS BAND OF SHOWERS WILL FALL APART FAIRLY QUICKLY AS IT MOVES NORTH. A MORE SUBSTANTIAL BAND OF SHOWERS SHOULD DEVELOP TUESDAY NIGHT WHICH IS PROGGED TO SWEEP INTO PARTS OF WRN AND NCNTL NEB PRODUCING AROUND 1/2 TO 3/4 OF AN INCH OF RAIN ON WEDNESDAY. THE GFS APPEARS TO SUFFERING QPF FEEDBACK PROBLEMS. TIME HEIGHTS SHOW 20 UBARS OF LIFT EXTENDING UPWARD TO OVER 500 MB AND THE QPF LOOKS OVERDONE. A 4-WAY BLEND OF NAM...GEM...ECM AND GFS WAS USED AS A BASIS FOR QPF AND POPS WHICH SUGGESTED DEFINITE RAIN CHANCES WEDNESDAY. THE STORM SYSTEM SHOULD CLEAR THE FCST AREA LATE WEDNESDAY NIGHT WITH CLEARING SKIES ON THURSDAY. THEREAFTER A PERIOD OF WARM AIR ADVECTION DEVELOPS FRIDAY AHEAD OF A DEEP UPPER LEVEL TROF SITUATED ACROSS THE WRN U.S.. STRATUS AND SHOWERS ARE POSSIBLE EARLY FRIDAY MORNING. A STRONG DISTURBANCE WILL LIFT THROUGH THE NRN HIGH PLAINS FRIDAY AFTN AND FRIDAY NIGHT. TSTMS ARE POSSIBLE ACROSS NORTHERN PORTIONS OF THE FCST AREA AS THIS DISTURBANCE LIFT THROUGH THE PLAINS. A PV15 ANOMALY WILL BE OPERATING IN TANDEM WITH THE DISTURBANCE AND A DRYLINE BULGE SHOULD DEVELOP FOLLOWED BY A STRONG PACIFIC COLD FRONT. HIGH PRESSURE AND COOL WEATHER IS EXPECTED SATURDAY THROUGH MONDAY WITH HIGHS IN THE 50S TO LOWER 60S. AVIATION... WIND SPEEDS ARE EXPECTED TO DECREASE THIS EVENING...HOWEVER GUSTS ARE EXPECTED TO STAY AT OR ABOVE 25KTS THROUGH THE OVERNIGHT HOURS AND MUCH OF TUESDAY MORNING. LOCATIONS ACROSS SOUTHWEST INTO CENTRAL NEBRASKA /FROM KOGA TO KTIF TO KONL/ WILL SEE THE HIGHER WINDS PERSIST THE LONGEST...WITH GUSTS OVER 30KTS. MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE THIS EVENING LEADING TO FURTHER DEVELOPMENT OF STRATUS AND MVFR CEILINGS. THERE ARE MIXED SIGNALS ON THE HEIGHT OF THIS CLOUD LAYER. SO ALTHOUGH FAIRLY CONFIDENT ON STRATUS ACROSS THE AREA...DO HAVE A CONSIDERATE AMOUNT OF UNCERTAINTY ON THE CLOUD HEIGHT. NAM WOULD SAY IFR CEILINGS WHILE OTHER SOLUTIONS WOULD ACTUALLY RAISE THE CEILINGS TO ABOUT 5K FEET. AT THIS TIME...KEPT A STABLE FORECAST WITH CEILINGS AT BOTH KVTN AND KLBF AT 2500 FT THROUGH TUESDAY MORNING. && .LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ TUESDAY FOR NEZ057-058- 069-070. WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR NEZ005- 006-008-009-024>027-036>038-059. HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR NEZ004-022-023- 056-094. WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR NEZ004-094. WIND ADVISORY UNTIL 6 AM MDT TUESDAY FOR NEZ056. WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR NEZ022-023. WIND ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ TUESDAY FOR NEZ035- 071. && $$ SHORT TERM/EXTENDED...CDC AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1040 PM EDT MON APR 2 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TONIGHT THROUGH EARLY TUESDAY BEFORE IT MOVES OFFSHORE. UNSETTLED CONDITIONS WILL PERSIST THROUGH MID WEEK AS THIS FRONT RETURNS NORTH AS A WARM FRONT ON TUESDAY. ANOTHER COLD FRONT WILL TRACK SOUTH THROUGH THE AREA WEDNESDAY NIGHT INTO THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR FRIDAY NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN ACROSS THE SOUTHEAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 PM MONDAY...THE LEADING EDGE OF THE NE-E SURGE IS NOW WEST AND SOUTH OF THE ILM CWA. THIS SURGE AT THIS TIME BEST ILLUSTRATED WITH 11-3.9 MICRON SAT IMAGERY TRENDS OVERLAID WITH LAPS SFC WIND FIELDS. LOOK FOR A MUCH MORE STABLE...COOLER AND DRIER AIR MASS TO OVERSPREAD THE ILM CWA. THE COOLER AND DRIER PORTIONS OF THIS AIR MASS WILL LIE ACROSS THE NE PORTIONS OF THE ILM CWA. WITH THE SFC FRONT STALLING ALONG THE SAVANNAH RIVER VALLEY...A SHALLOWER COOL/DRY AIR MASS CHANGE WILL LIE ACROSS THE SC PORTIONS OF THE ILM CWA. THIS HAS RESULTED IN LOWER MINS BEING FORECAST ACROSS THE ILM NC CWA...WITH ILM SC LOWS AS MUCH AS 4 TO 8 DEGREES HIER THEN THE ILM NC CWA. NULL POPS FOR THE REMAINDER OF THE OVERNIGHT. NAMBUFR SOUNDINGS FOR TONIGHT INDICATE POSSIBLE POST FRONTAL FEW TO SCT SC MAINLY FOR THE ILM SC CWA...BUT FOR THE MOST PART WILL STICK WITH A CLEAR/MOSTLY CLEAR SKY CONDITION. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...BACKDOOR COLD FRONT OFF TO THE SOUTH WILL ALLOW RIDGE OF HIGH PRESSURE TO NOSE INTO THE CAROLINAS FROM THE NORTH EARLY TUESDAY. THIS AIRMASS WILL QUICKLY SLIDE OFF THE COAST BY AFTERNOON. SOME MOISTURE RETURN WILL BE ENSUE FROM WEST TO EAST ACROSS THE CAROLINAS. IN THE UPPER LEVELS A SHORT AMPLITUDE RIDGE WILL HOLD ON FOR THE MOST PART. MODELS STRUGGLING WITH SOME CONVECTIVELY INDUCED VORT CENTERS EMANATING FROM TEXAS...AND DEEPENING ON THE TRACK AND STRENGTH OF THESE FEATURES THEY MAY BE ABLE TO SERVE AS SOME WEAK FORCING LOCALLY. BARRING THIS POSSIBILITY MOST OF THE AREA LOOKS TO REMAIN RAIN-FREE WITH NEAR SEASONABLE TEMPERATURES. ADVECTION OF WARMTH AND MOISTURE WILL CONTINUE FOR THE REMAINDER OF THE PERIOD KEEPING TUESDAY NIGHT VERY MILD ESPECIALLY DUE TO THE INCREASED CLOUD COVER. THE UPPER RIDGE WILL CONTINUE TO BE WEAKENED ON WEDNESDAY ALLOWING CLEARER PASSAGE OF SOME WEAK VORTICITY CENTERS. A PREFRONTAL PIEDMONT TROUGH WILL TEND TO FOCUS MOST OF THE SCATTERED CONVECTION OVER WESTERN ZONES INITIALLY. HOWEVER SINCE STORMS WILL HAVE A WELL DEFINED EASTWARD MOTION THERE WILL BE ONLY A SLIGHT GRADIENT IN FCST POPS AT THIS TIME. QPF WILL BE HIGHER OVER WRN ZONES (ALTHOUGH STILL QUITE LOW). DESPITE THE CLOUD COVER MOST PLACES SHOULD HAVE NO TROUBLE SEEING A HIGH IN THE LOW 80S. COLD FRONT ARRIVES LATE WEDNESDAY NIGHT AND LOOKS QUITE MOISTURE-CHALLENGED. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...PROGRESSIVE PATTERN WILL PREVAIL THROUGH THE EXTENDED AS A MID LEVEL CYCLONE MOVES ACROSS EARLY FOLLOWED BY BRIEF RIDGING. FINALLY...AT THE END OF THE PERIOD SUBTLE TROUGHING WILL MOVE ACROSS. THE FORECAST CHALLENGES CONTINUE TO CENTER AROUND TIMING AND MAGNITUDE FOR FRIDAY TRANSITIONING TO A TEMPERATURE FORECAST FOR THE WEEKEND. STILL SOME UNCERTAINTY WITH REGARDS TO THE CHARACTERISTIC OF THE SYSTEM FRIDAY AS THE LATEST GFS...AND PAST COUPLE OF CYCLES FOR THAT MATTER SHOW A CLOSED MID LEVEL CYCLONE MOVING ACROSS THE UPSTATE OF SOUTH CAROLINA THEN OPENING UP AND MOVING OFF QUICKLY. THE ECMWF AND ENSEMBLES ARE SIMILAR BUT A BIT FURTHER SOUTH. I HAVE INCREASED POPS TO LIKELY FOR FRIDAY MATCHING HPC AND INCREASED POPS INTO SATURDAY MORNING TO ADDRESS SLOWER TIMING WITH A SYSTEM THAT REMAINS CLOSED FOR A LONGER PERIOD OF TIME. TEMPERATURES DROP TO JUST BELOW CLIMATOLOGY SATURDAY AND SUNDAY BEFORE REBOUNDING QUICKLY WITH A SOUTHWEST FLOW MONDAY. SUNDAY SHOULD BE THE COOLEST MORNING COUPLED WITH THE BEST RADIATIONAL CONDITIONS WITH MID TO UPPER 40S CWA WIDE. SOME CLIMATOLOGICALLY FAVORED AREAS COULD SEE A DEGREE OR TWO BELOW 45. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...DYING CONVECTION ALONG THE FRONT WILL NOT BE A FACTOR...WITH HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE FORECAST PERIOD. NO FOG EXPECTED TONIGHT DUE TO UNFAVORABLE MOISTURE PROFILES. LIGHT MAINLY NORTHEAST WINDS OVERNIGHT. TUESDAY...CONTINUED VFR WITH VEERING WINDS TO THE SOUTHEAST BY AFTERNOON. THERE WILL NOT BE ENOUGH MOISTURE TO SUPPORT CONVECTION. ANY CONVECTION AT ALL WILL LIKELY BE SOUTH OF THE REGION ALONG A STALLED FRONT. EXTENDED OUTLOOK...VFR TUESDAY NIGHT. LOW CONFIDENCE ISOLATED SHOWERS AND THUNDERSTORMS WITH TEMPO MVFR WEDNESDAY THROUGH THURSDAY NIGHT. A GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS WITH WIDESPREAD IFR FRIDAY. VFR SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1040 PM MONDAY...POST FRONTAL NE-E SURGE ACCOMPANIED BY COLD AIR ADVECTION HAS PUSHED SOUTH OF THE ILM WATERS...AND IS PROGGED TO STALL IN THE VICINITY OF THE MOUTH OF THE SAVANNAH RIVER OVERNIGHT INTO TUESDAY. CURRENT BUOY OBS AND HRRR WIND OUTPUT INDICATE SPEEDS OF AROUND 15 KT FOR THE REMAINDER OF THE NIGHT...POSSIBLY DOWN TO 10-15 KT NORTH OF CAPE FEAR WHERE GRADIENT WILL RELAX SOME AND THE POST FRONTAL CAA SURGE ENDS. LOOK FOR SEAS IN THE 2 TO 4 FT RANGE THRUOUT. THE EXCEPTION WILL BE UP TO 5 FT ACROSS THE WATERS OFF CAPE FEAR THROUGH MIDNIGHT. SEAS PRIMARILY A REFLECTION OF SHORT PERIOD WIND DRIVEN WAVES RUNNING AT 4-5 SECOND PERIODS...ACCOMPANIED BY AN UNDERLYING AND WEAK 1 FT OR LESS EASTERLY GROUND SWELL AT A 10 SECOND PERIOD. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...NORTHEAST WINDS ON TUESDAY WITH A BACKDOOR FRONT OFF TO THE SOUTH AND HIGH PRESSURE BUILDING IN FROM THE NORTH EARLY TUESDAY. THIS HIGH WILL MOVE OFF THE COAST BY AFTERNOON BRINGING VEERING AND PERHAPS DECREASING WINDS. VEERING CONTINUES TUESDAY NIGHT BRINGING A MORE DEFINED SOUTHERLY COMPONENT. NO REAL SWELL ENERGY ON THE RADAR SO SEAS GENERALLY 2 TO 3 FT THROUGHOUT. WEDNESDAY BRINGS A PREFRONTAL SOUTHWESTERLY FLOW REGIME WITH A TIGHTENING GRADIENT. THIS SHOULD ADD ABOUT A FOOT TO THE PREDOMINANT WAVE HEIGHT. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...NORTHEAST FLOW INITIALLY WILL VEER A BIT TO MORE TO AN EASTERLY DIRECTION EARLY FRIDAY AS LOW PRESSURE DROPS WELL TO THE SOUTH. STILL SOME UNCERTAINTY OF THE EXACT TIMING AND PLACEMENT OF THE SYSTEM SO WE COULD SEE WINDS VEER EVEN MORE THROUGH FRIDAY THAN THE CURRENT FORECAST ADVERTISES. NORTHEASTERLY FLOW LATE FRIDAY THROUGH SATURDAY AS HIGH PRESSURE BUILDS IN BEHIND THE SYSTEM. AS USUAL SURGES ARE DIFFICULT TO TIME BUT SHOULD SEE SEVERAL HOURS OF SPEEDS NEAR 20 KNOTS ACROSS THE OUTER WATERS. WAVEWATCH SEAS INCREASE FROM 2-4 FEET EARLY TO 4-7 FEET LATE IN THE PERIOD WITH THE STRONGER FETCH. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...HOEHLER SHORT TERM...BACON LONG TERM...KEEBLER AVIATION...LOEWENTHAL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
144 AM EDT SUN APR 1 2012 .SYNOPSIS... ISOLATED SHOWERS AND THUNDERSTORMS WILL LINGER OVER THE AREA AS A COLD FRONT MOVES SOUTH ACROSS THE AREA EARLY THIS MORNING...WITH DRY WEATHER SETTLING IN TODAY AND TONIGHT. A DRY COLD FRONT WILL DROP QUICKLY SOUTHEAST OVER THE AREA MONDAY. UNSETTLED CONDITIONS WILL RETURN BY MID WEEK...AS A LOW PRESSURE SYSTEM APPROACHES THE EASTERN CAROLINAS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1030 PM SATURDAY...LATEST SFC ANALYSIS PLACES THE COLD FRONT PARTIALLY INTO NC...DROPPING FROM THE NORTH. THE CONVECTION ACROSS THE NE PORTION OF THE STATE IS BASICALLY ALONG THE COLD FRONT ITSELF. THE OUTFLOW FROM THIS CONVECTION IS AIDING THE COLD FRONTS PUSH SOUTHWARD...AND COULD REACH THE NORTHERN PORTIONS OF THE ILM CWA BY MIDNIGHT THROUGH 1 AM SUNDAY. SLIGHTLY FASTER THAN 1ST PROGGED WITH HRRR AND AN EARLIER NAM MODEL RUN. HRRR INDICATES 1 MORE POTENTIAL MINI ROUND OF CONVECTION TO PUSH THROUGH IMMEDIATELY AHEAD OF THE COLD FRONT. WILL CONTINUE WITH LOW CHANCE POPS THROUGH ROUGHLY 2 AM SUNDAY. LOOKING AT NAM 1K-8H PARTIAL THICKNESS PACKING AND HRRR HRLY WINDS...THE COLD FRONT WILL DROP NEARLY DUE SOUTH ACROSS THE FA BETWEEN 1AM AND 7AM SUNDAY. LOOK FOR NW WINDS TO VEER TO THE N-NE ALONG WITH A MINI CAA SURGE THAT WILL ONLY LAST THRU MIDDAY SUNDAY B4 SHUTTING OFF. WITH THREAT OF PCPN INTO THE EARLY AM HRS OF SUNDAY AND CLOUDS STICKING AROUND FOR MUCH OF THE REMAINDER OF THE NIGHT. HAVE KEPT FOG DEVELOPMENT AT A MINIMUM WITH AN INCREASED POTENTIAL FOR A BRIEF STRATUS DECK UP THRU 1-2 HRS AFTER DAYBREAK. HAVE KEPT OVERNIGHT LOWS STABLE AFTER INCREASING A DEGREE OR 3 EARLIER...ESPECIALLY THE SOUTHERNMOST LOCALES WHERE THE FROPA WILL COINCIDE WITH DAYBREAK. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...COLD FRONT POSITIONED JUST OFFSHORE AT THE START OF THE PERIOD. NVA AND SOME DRY AIR ADVECTION THROUGH THE MID LEVELS OF THE COLUMN KEEP SUNDAY SUNNY...BUT TEMPS WILL WARM WELL INTO THE 70S WITH LACK OF ANY CAA AND ENHANCED RIDGING ALOFT. TEMPS REMAIN WELL ABOVE CLIMO SUNDAY NIGHT AS GRADIENT TIGHTENS BETWEEN RIDGE OF HIGH PRESSURE AND ADVANCING COLD FRONT FROM THE NORTH. THIS COMBINED WITH SOME INCREASING MID-LEVEL CLOUDINESS WILL KEEPS MINS IN THE MID/UPPER 50S. SHORTWAVE TROUGH ROTATING DOWN FROM NEW ENGLAND SPAWNS A SURFACE LOW IN THE MID ATLANTIC WHICH TRIES TO DRIVE A COLD FRONT THROUGH EARLY MONDAY. WITH N/NW FLOW ALOFT...ANTICIPATE THIS FRONT TO WORK ALL THE WAY SOUTH THROUGH THE CWA BY AFTN. DURING FROPA...MID LEVEL LAPSE RATES STEEPEN AND FORECAST SOUNDINGS DEPICT INCREASING SATURATION IN THE 800-500MB LAYER. FORCING IS NOT STRONG...BUT WILL ADD A SCHC POP FOR TSTMS MONDAY...DECREASING FROM NORTH TO SOUTH THROUGH THE AFTN. THIS FRONT WILL MAKE FOR A DIFFICULT TEMP FORECAST MONDAY AS WELL...WITH 850MB TEMPS POSSIBLY FALLING THROUGH PEAK HEATING...ESPECIALLY ACROSS NE ZONES. EXPECT TEMPS TO RANGE FROM THE UPPER 80S IN THE TYPICAL WARM PEE DEE LOCATIONS...TO AROUND 80 IN THE NORTHEAST ZONES...EVEN WITH FAVORED DOWNSLOPE COMPRESSIONAL WARMING OCCURRING. FRONT STALLS SOUTH OF THE AREA AND SOME ISENTROPIC LIFT BEGINS LATE MONDAY NIGHT...ESPECIALLY ACROSS THE SOUTHERN PORTIONS OF THE CWA. WILL RAMP POP BACK UP TO SCHC ACROSS THE SOUTH. MINS WILL FALL TO AROUND 50 ACROSS THE NORTHEAST CWA...TO NEAR 60 IN THE SOUTH. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 300 PM SATURDAY...AMPLITUDE WILL ONCE AGAIN BE THE NAME OF THE GAME FOR THE EXTENDED AS A LARGE MID LEVEL CYCLONE WILL BE WOBBLING OVER THE FOUR CORNERS REGION INITIALLY WITH RIDGING JUST WEST OF OUR REGION. AT THE SURFACE A FRONT WILL RESIDE JUST TO THE SOUTHWEST BEFORE GETTING WASHED OUT WEDNESDAY. A BACKDOOR FRONT WILL MOVE ACROSS THURSDAY INCREASING THE WEAK FORCING MECHANISMS IN PLACE...THIS AS THE MID LEVEL PATTERN AMPLIFIES SLIGHTLY. FINALLY LATE THURSDAY AND FRIDAY THE MAIN SYSTEM ASSOCIATED WITH THE PREVIOUSLY MENTIONED MID LEVEL LOW MOVES ACROSS. BOTTOM LINE...I HAVE INCREASED POPS FROM TUESDAY THROUGH THURSDAY INCREMENTALLY BASED ON A DIURNAL SCENARIO. THE NEW DAY...SATURDAY LOOKS DRY AT THIS POINT BUT THE INHERIT DIFFICULTIES OF FORECASTING A CLOSED SYSTEM THIS FAR OUT IN TIME MAKE FOR A LOW CONFIDENCE DRY FORECAST. REGARDING TEMPERATURES...HAVE INCREASED TEMPERATURES A BIT ACROSS THE BOARD TO MATCH GUIDANCE AND ADJACENT OFFICES BUT OVERALL TRENDS OF SLIGHTLY ABOVE EARLY TREND TO NEAR NORMAL LATE REMAIN INTACT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...CONVECTION ASSOCIATED WITH COLD FRONT WILL DROP INTO THE NORTHERN TERMINALS SHORTLY AFTER TAF ISSUANCE. THE CONVECTION WILL BE WANING WITH MVFR/IFR CONDITIONS INTO DAYBREAK BEHIND THE FRONT. WINDS WILL SHIFT TO THE NORTHEAST...WITH MODERATE CONFIDENCE FOR AN IFR/NEAR MVFR CEILING. SOME MVFR VISIBILITIES ARE POSSIBLE BUT LESS LIKELY. THE STRATUS SHOULD MIX OUT AROUND 14Z...BUT TAKE A BIT LONGER WITH THE NORTHEAST WIND SURGE. WINDS WILL VEER TO EAST NORTHEAST...THEN SOUTHEAST ALONG THE COAST IN THE AFTERNOON WITH THE RESULTANT WIND FROM A WEAK TO MODERATE SEA BREEZE. EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORM MONDAY AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY WITH A BETTER CHANCE FOR PRECIP ON THURSDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM SATURDAY...LATEST OBSERVATIONS OVER THE ILM NC WATERS INDICATE SEAS STILL RUNNING WITHIN SCA THRESHOLDS ACROSS THE OUTER WATERS OFF CAPE FEAR. THE SCA WILL REMAIN THRU MIDNIGHT WHICH IS AMPLE TIME FOR THESE SEAS TO SUBSIDE BELOW SCA THRESHOLDS. GUIDANCE CONTINUES TO FURTHER SUBSIDE SEAS DURING THE PRE-DAWN HRS OF SUNDAY AS A COLD FRONT DROPS SOUTH ACROSS THE ILM WATERS BETWEEN 1 AM AND 7 AM SUNDAY. WINDS WILL VEER TO THE N-NE AFTER FROPA AND AID IN KNOCKING DOWN THE BUILT UP SHORT PERIOD SW WIND DRIVEN SEAS FROM THE PAST 1-2 DAYS. COULD SEE THE LAST ROUND OF CONVECTION MOVE OFF THE MAINLAND THROUGH 2 AM SUNDAY. OTHERWISE...LOOK FOR A N-NE MINI SHORT LIVED COLD SURGE BEHIND THE COLD FRONT...LASTING THROUGH MID TO LATE SUNDAY MORNING. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 PM SATURDAY...COLD FRONT WILL BE POSITIONED OFFSHORE AT THE START OF THE PERIOD WITH N/NE WINDS ONGOING ACROSS THE WATERS. RIDGE OF HIGH PRESSURE BUILDS IN FROM THE SOUTH DURING THE AFTN AND WINDS BECOME LIGHT...VEERING TO THE SW THROUGH THE EVE AS A PRE FRONTAL AIRMASS MOVES OVER THE AREA AND INCREASING RAPIDLY TO 15-20 KTS SUN NIGHT AS A COLD FRONT APPROACHES FROM THE WEST. COLD FRONT DROPS SOUTH DURING MONDAY...AND WINDS WILL GRADUALLY VEER FROM SW TO N...THEN NE MONDAY NIGHT...ALL AT SPEEDS OF AROUND 10 KTS. LACK OF ANY MEANINGFUL SWELL WITHIN THE WAVE SPECTRUM MEANS THAT SEAS WILL BE PRIMARILY WIND DRIVEN...2-3 FT THROUGH THE PERIOD...WITH A COMBINATION OF NE AND SW CHOP SUNDAY...BECOMING DOMINATED BY NE WAVE ON MONDAY. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 300 PM SATURDAY...MAIN EVENT FOR THE MARINE COMMUNITY WILL BE THE BACK DOOR FRONT MOVING ACROSS THURSDAY. THIS FRONT WILL EVENTUALLY BRING ALL WINDS AROUND TO NORTHEAST BUT FOR MOST OF THE DAY THURSDAY THE NORTH CAROLINA AND SOUTH CAROLINA WATERS WILL BE DIVIDED BY THE FRONT. FOR EARLIER IN THE PERIOD...EASTERLY WINDS INITIALLY WITH A SOUTH TO SOUTHWESTERLY FLOW DEVELOPING LATER TUESDAY AND PREVAILING THROUGH WEDNESDAY. SEAS ARE GENERALLY 2-4 FEET WITH WINDS WAVES DOMINATING THE SPECTRUM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH/COLBY SHORT TERM...JDW LONG TERM...SHK AVIATION...HDL/COLBY
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
725 AM CDT SUN APR 1 2012 .DISCUSSION...WILL CANCEL THE NORTHERN PORTION OF THE DENSE FOG ADVISORY SINCE THE LOW CLOUDS AND FOG NEVER ADVECTED THAT FAR NORTH. THE OPPORTUNITY FOR DENSE FOG ACROSS THIS AREA IS NOW MINIMAL CONSIDERING SUNRISE HAS OCCURRED. MUCH OF THE REMAINDER OF THE ADVISORY STILL HAS DENSE FOG. && .AVIATION...LIFR/IFR CIGS/VSBY WILL CONTINUE TO AFFECT KBJI INTO THE MID MORNING HOURS. THIS IS STILL A CHANCE THESE CONDITIONS WILL AFFECT FARGO. KTVF/KGFK/KDVL APPEAR THAT THEY WILL BE VFR THE REMAINDER OF THE DAY. GUSTY SOUTHEAST WINDS EXPECTED TO DEVELOP BY AFTERNOON. && .PREV DISCUSSION... /ISSUED 350 AM CDT SUN APR 1 2012/ DISCUSSION...THE DENSE FOG IS BECOMING MORE WIDESPREAD AND ADVECTING TO THE NORTH AND WEST ACCORDING TO WEB CAMS AND OBSERVATIONS. THE HRRR IS DOING AN EXCELLENT JOB WITH THIS FOG...AND WILL FOLLOW FOR THE FORECAST. ISSUED A DENSE FOG ADVISORY FOR AREAS ALONG AND SOUTH OF A VALLEY CITY TO GRAND FORKS TO BAUDETTE LINE. RADAR SHOWS SHOWERS NEAR THE INTERNATIONAL BORDER...AND THESE WILL BE NORTH OF THE DENSE FOG AREA. FAIRLY CONFIDENT THAT THE DENSE FOG WILL BE ABLE TO ADVECT INTO THE VALLEY CITY...FARGO...AND GRAND FORKS AREAS. PREV DISCUSSION... /ISSUED 310 AM CDT SUN APR 1 2012/ SHORT TERM (SUN-TUE)...INTERESTING FORECAST WITH MULTIPLE CHALLENGES. MODEL DIFFERENCES ARISE ON MONDAY WITH TIMING OF FRONT. GEM/ECMWF SLOW WHILE NAM/GFS QUICKER. ECMWF HAS BEEN CONSISTENT WITH THE SLOW SOLUTION...BUT HAD BEEN AN OUTLIER UNTIL THIS SET OF MODEL RUNS WITH THE GEM TRENDING SLOWER. WILL HAVE TO FOLLOW A BLEND. UPPER RIDGE BUILDING INTO THE REGION FOR TODAY. AHEAD OF THIS UPPER RIDGING...SCATTERED SHOWERS ASSOCIATED WITH WEAK WAVE (WARM AIR ADVECTION) POSSIBLE DURING THE EARLY MORNING HOURS...EXITING THE NE FA BY NOON. LOW-LEVEL FLOW IS INCREASING FROM THE SOUTHEAST...AND ADVECTING LOW LEVEL MOISTURE (LOW CLOUDS/FOG) BACK INTO THE REGION FROM CENTRAL MINNESOTA. FOLLOWING HRRR...EXPECT THESE CIGS TO ADVECT INTO ALL BUT THE FAR NORTHERN FA BY 12Z...THEN SCATTER WITH DAYTIME HEATING AND STRONG SE WINDS BY MID TO LATE MORNING. DENSE FOG POSSIBLE UNTIL MID-MORNING...AND WILL MONITOR CONDITIONS FOR POSSIBLE ADVISORY. SO FAR DENSE FOG IS NOT TOO WIDESPREAD...BUT HRRR SUGGESTS THAT DENSE FOG WILL BECOME WIDESPREAD BY 05Z. WINDS WILL BE CLOSE TO ADVISORY CRITERIA THIS AFTERNOON...BUT PARAMETERS SUGGEST JUST BELOW. WITH SOLAR AND GOOD MIXING...EXPECT FULL HEATING POTENTIAL...WITH MAX TEMPS AROUND 80F ACROSS THE SW FA TO UPPER 60S ACROSS THE NE FA. EXPECTED TEMP VALUES ALONG AND WEST OF THE VALLEY WILL BE RECORD HIGHS. UPPER RIDGING WILL BE BRIEF WITH UPPER FLOW BECOMING SOUTHWEST TONIGHT. STRONG 850MB JET WILL DEVELOP AND TRANSPORT MOISTURE ALONG AND AHEAD COLD FRONT. FOLLOWING MODEL COMPROMISE FOR TIMING...BEST PRECIP CHANCES WILL BE ALONG AND EAST OF THE VALLEY...FROM 06Z MON INTO THE AFTERNOON HOURS. 850MB CAPE 1000-1500 J/KG INTO THE EARLY MORNING ALONG WITH STRONG LOW-LEVEL JET ACROSS SE FA COULD LEAD TO ISOLD SEVERE HAIL (SPC HAS A 5% PROBABILITY)...ALTHOUGH DEEP LAYER SHEAR WILL BE MARGINAL. UPPER TROUGH SWINGS THROUGH BY MON NIGHT. AS THIS FEATURE APPROACHES CANNOT RULE OUT SHOWERS ANYWHERE ON MONDAY...BUT HEAVIEST RAINFALL SHOULD BE IN MINNESOTA COUNTIES (AHEAD OF COLD FRONT WHERE PWATS ARE HIGHEST). CLOUDS AND COOLER AIRMASS WILL LEAD TO MUCH COLDER TEMPS ON MONDAY (ALTHOUGH STILL ABOVE NORMAL). RIDGING MOVES BACK INTO THE REGION ON TUESDAY...AND TEMPS BEGIN TO TREND WARMER AGAIN. LONG TERM (WED-SAT)...RIDGING DOMINATES INTO FRIDAY BEFORE MOVING TO THE EAST ALLOWING SW FLOW ALOFT. DRY AND WARM CONDITIONS SHOULD TRANSITION TO COOLER AND WETTER BY SATURDAY IF MODELS HAVE TIMING CORRECT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NDZ038-039- 049-052-053. MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ003-016- 017-023-024-027>032-040. && $$ TG
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
350 AM CDT SUN APR 1 2012 .DISCUSSION...THE DENSE FOG IS BECOMING MORE WIDESPREAD AND ADVECTING TO THE NORTH AND WEST ACCORDING TO WEB CAMS AND OBSERVATIONS. THE HRRR IS DOING AN EXCELLENT JOB WITH THIS FOG...AND WILL FOLLOW FOR THE FORECAST. ISSUED A DENSE FOG ADVISORY FOR AREAS ALONG AND SOUTH OF A VALLEY CITY TO GRAND FORKS TO BAUDETTE LINE. RADAR SHOWS SHOWERS NEAR THE INTERNATIONAL BORDER...AND THESE WILL BE NORTH OF THE DENSE FOG AREA. FAIRLY CONFIDENT THAT THE DENSE FOG WILL BE ABLE TO ADVECT INTO THE VALLEY CITY...FARGO...AND GRAND FORKS AREAS. && .AVIATION...LIFR/IFR CIGS/VSBY WILL CONTINUE TO ADVECT NORTHEAST FROM WEST CENTRAL MINNESOTA INTO THE EARLY MORNING HOURS. THE MAIN QUESTION WILL BE HOW FAR TO THE NORTH/WEST THESE CONDITIONS WILL ADVECT. CURRENT HI-RES MODEL GUIDANCE SUGGESTS THAT A SURE BET WILL BE KBJI AND KFAR...WHILE KGFK AND KTVF WILL BE ON THE EDGE...AND KDVL SHOULD REMAIN VFR. MOST GUIDANCE SUGGESTS ALL SITES VFR BY 18Z. GUSTY SOUTHEAST WINDS EXPECTED TO DEVELOP BY AFTERNOON. && .PREV DISCUSSION... /ISSUED 310 AM CDT SUN APR 1 2012/ SHORT TERM (SUN-TUE)...INTERESTING FORECAST WITH MULTIPLE CHALLENGES. MODEL DIFFERENCES ARISE ON MONDAY WITH TIMING OF FRONT. GEM/ECMWF SLOW WHILE NAM/GFS QUICKER. ECMWF HAS BEEN CONSISTENT WITH THE SLOW SOLUTION...BUT HAD BEEN AN OUTLIER UNTIL THIS SET OF MODEL RUNS WITH THE GEM TRENDING SLOWER. WILL HAVE TO FOLLOW A BLEND. UPPER RIDGE BUILDING INTO THE REGION FOR TODAY. AHEAD OF THIS UPPER RIDGING...SCATTERED SHOWERS ASSOCIATED WITH WEAK WAVE (WARM AIR ADVECTION) POSSIBLE DURING THE EARLY MORNING HOURS...EXITING THE NE FA BY NOON. LOW-LEVEL FLOW IS INCREASING FROM THE SOUTHEAST...AND ADVECTING LOW LEVEL MOISTURE (LOW CLOUDS/FOG) BACK INTO THE REGION FROM CENTRAL MINNESOTA. FOLLOWING HRRR...EXPECT THESE CIGS TO ADVECT INTO ALL BUT THE FAR NORTHERN FA BY 12Z...THEN SCATTER WITH DAYTIME HEATING AND STRONG SE WINDS BY MID TO LATE MORNING. DENSE FOG POSSIBLE UNTIL MID-MORNING...AND WILL MONITOR CONDITIONS FOR POSSIBLE ADVISORY. SO FAR DENSE FOG IS NOT TOO WIDESPREAD...BUT HRRR SUGGESTS THAT DENSE FOG WILL BECOME WIDESPREAD BY 05Z. WINDS WILL BE CLOSE TO ADVISORY CRITERIA THIS AFTERNOON...BUT PARAMETERS SUGGEST JUST BELOW. WITH SOLAR AND GOOD MIXING...EXPECT FULL HEATING POTENTIAL...WITH MAX TEMPS AROUND 80F ACROSS THE SW FA TO UPPER 60S ACROSS THE NE FA. EXPECTED TEMP VALUES ALONG AND WEST OF THE VALLEY WILL BE RECORD HIGHS. UPPER RIDGING WILL BE BRIEF WITH UPPER FLOW BECOMING SOUTHWEST TONIGHT. STRONG 850MB JET WILL DEVELOP AND TRANSPORT MOISTURE ALONG AND AHEAD COLD FRONT. FOLLOWING MODEL COMPROMISE FOR TIMING...BEST PRECIP CHANCES WILL BE ALONG AND EAST OF THE VALLEY...FROM 06Z MON INTO THE AFTERNOON HOURS. 850MB CAPE 1000-1500 J/KG INTO THE EARLY MORNING ALONG WITH STRONG LOW-LEVEL JET ACROSS SE FA COULD LEAD TO ISOLD SEVERE HAIL (SPC HAS A 5% PROBABILITY)...ALTHOUGH DEEP LAYER SHEAR WILL BE MARGINAL. UPPER TROUGH SWINGS THROUGH BY MON NIGHT. AS THIS FEATURE APPROACHES CANNOT RULE OUT SHOWERS ANYWHERE ON MONDAY...BUT HEAVIEST RAINFALL SHOULD BE IN MINNESOTA COUNTIES (AHEAD OF COLD FRONT WHERE PWATS ARE HIGHEST). CLOUDS AND COOLER AIRMASS WILL LEAD TO MUCH COLDER TEMPS ON MONDAY (ALTHOUGH STILL ABOVE NORMAL). RIDGING MOVES BACK INTO THE REGION ON TUESDAY...AND TEMPS BEGIN TO TREND WARMER AGAIN. LONG TERM (WED-SAT)...RIDGING DOMINATES INTO FRIDAY BEFORE MOVING TO THE EAST ALLOWING SW FLOW ALOFT. DRY AND WARM CONDITIONS SHOULD TRANSITION TO COOLER AND WETTER BY SATURDAY IF MODELS HAVE TIMING CORRECT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NDZ027-029- 030-038-039-049-052-053. MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ001>003- 006-008-009-013>017-022>024-027>032-040. && $$ TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
349 AM CDT SUN APR 1 2012 .SHORT TERM...TODAY THROUGH MONDAY... RECORD WARMTH AND CRITICAL FIRE WEATHER WILL HIGHLIGHT THE SHORT TERM FORECAST FOR TODAY...FOLLOWED BY COOLER...BUT STILL ABOVE NORMAL TEMPERATURES FOR MONDAY WITH MARGINAL FIRE WEATHER CONCERNS. FOR THIS MORNING ADDED A PATCHY FOG MENTION TO THE JAMES RIVER VALLEY AS STRATUS AND FOG CONTINUE TO EXPAND EAST AS PROGGED BY THE LATEST HRRR MODEL RUNS OVERNIGHT. OTHERWISE...AS OF 08 UTC...BROAD SURFACE LOW PRESSURE WAS ANALYZED ACROSS MUCH OF CENTRAL AND EASTERN MONTANA...WITH TWO DISTINCT CIRCULATIONS ACROSS FAR SOUTHEAST MONTANA AND SOUTHEAST ALBERTA...WITH A COLD FRONT ACROSS CENTRAL MONTANA AND A WARM FRONT FROM NEAR HAVRE MONTANA THROUGH FAR SOUTHEAST SOUTH DAKOTA. THE OVERALL PROPAGATION OF THE SYSTEM HAS SLOWED...WITH THE COLD FRONT FORECAST TO REACH THE NORTH DAKOTA BORDER CLOSER TO 18 UTC...WITH THE SURFACE WARM FRONT AT THAT TIME EXTENDING FROM APPROXIMATELY CROSBY THROUGH LINTON. NEAR TO RECORD BREAKING HIGH TEMPERATURES ARE FORECAST IN THE WARM SECTOR OF THE SURFACE LOW ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA ENHANCED BY COMPRESSIONAL HEATING AND MIXING JUST AHEAD OF THE COLD FRONT. SHOWN BELOW ARE FORECAST HIGHS AND RECORDS FOR TODAY FOR SELECT LOCATIONS ACROSS THE AREA. SITE FORECAST RECORD YEAR DICKINSON 76 74 1964 MINOT 78 72 1928 BISMARCK 82 75 1976 JAMESTOWN 78 78 1907 WILLISTON 70 72 1991 OVERALL THE DETERMINISTIC AND STATISTICAL GUIDANCE SUITE LOW LEVEL THERMAL FIELDS ARE IN GOOD AGREEMENT...AND CHOSE TO GO A COUPLE OF DEGREES ABOVE THE CONSENSUS GIVEN THE EFFECTS OF BROWN VEGETATION ENHANCING MIXING HEIGHTS. THE AFOREMENTIONED COLD FRONT IS EXPECTED TO PROPAGATE AS FAR EAST AS NORTH DAKOTA HIGHWAY 3 BY LATE AFTERNOON. THE WIND FIELD BEHIND THE COLD FRONT IS FORECAST TO BE SLIGHTLY WEAKER COMPARED TO PREVIOUS FORECASTS...WITH THE 01/00 UTC NAM/GFS BUFR SOUNDINGS INDICATING A WEAK INVERSION NEAR 800-750 MB...WHICH WILL LIMIT MIXING HEIGHTS. THAT SAID...POST FRONTAL WINDS SUSTAINED TO NEAR 20 KTS WITH GUSTS OF 25-30KTS ARE EXPECTED WITH MINIMUM RH VALUES OF 15 TO 25 PERCENT WITH POST FRONTAL TEMPERATURES STILL IN THE 60S AND 70S. WHEN COMBINED WITH THE ABUNDANCE OF DRY FUELS AND LACK OF GREEN UP....VERY HIGH FIRE DANGER IS FORECAST ACROSS MUCH OF THE AREA...WITH EXTREME FIRE DANGER ACROSS THE FAR SOUTHWEST. THE CURRENT RED FLAG WARNING LOOKS GOOD...EXCEPT FOR THE FAR EASTERN TIER OF COUNTIES WHICH MAY NOT SEE FRONTAL PASSAGE UNTIL THE EARLY EVENING...AND THUS NOT MEET CRITERIA. HOWEVER...IT WILL BE CLOSE AND WILL LEAVE THE WARNING AS IS FOR NOW. FOR TONIGHT...STRONG ISALLOBARIC FORCING VIA AN 8-10 MB/6 HR PRESSURE RISE BUBBLE IS FORECAST ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA BEHIND THE COLD FRONT. THE QUESTION WILL BE HOW WELL THE BOUNDARY LAYER WILL BE ABLE TO STAY MIXED AFTER SUNSET. AT THIS TIME THE BEST POTENTIAL LOOKS TO BE ACROSS THE SOUTHWEST AND SOUTH CENTRAL...WHERE LITTLE CHANGE IN WIND MAGNITUDE IS POSSIBLE EVEN AFTER SUNSET...WHICH IS OF CONCERN FOR ANY ONGOING FIRES THAT MAY START TODAY. GIVEN THE EXPECTED MIXING CWA WIDE...FOLLOWED A CONSENSUS OF 01/00 UTC NAM/GFS FOR OVERNIGHT LOWS...WHICH YIELDS WIDESPREAD 40S FOR NEARLY ALL OF THE CWA...WITH LOWS POSSIBLY AS WARM AS 50 ACROSS THE SOUTH CENTRAL. MONDAY LOOKS TO BE COOLER...WITH HIGHS IN THE 50S WITH GOOD AFTERNOON MIXING CWA WIDE. HOWEVER...TEMPERATURES ARE STILL FORECAST TO BE 5 TO 10 DEGREES ABOVE NORMAL. DESPITE THE COOLER TEMPERATURES...MARGINAL FIRE WEATHER CONCERNS ARE POSSIBLE ACROSS THE FAR SOUTHWEST WHERE WIND GUSTS IN EXCESS OF 25 KTS MAY BE POSSIBLE...WITH RH VALUES OF 20-25 PERCENT. GIVEN THE MARGINAL NATURE OF THE THREAT AND TO AVOID CONFUSION WITH THE CURRENT FIRE WEATHER HEADLINES...WILL LET THE DAY SHIFT EVALUATE FURTHER. .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... THE MEDIUM RANGE MODELS ARE CONSISTENT WITH RESPECT TO THE SYNOPTIC PATTERN OVER THE NORTHERN PLAINS THROUGH THURSDAY. MODEL SOLUTIONS BEGIN TO DIVERGE WITH RESPECT TO THE UPPER PATTERN FRIDAY AND SATURDAY. AS A RESULT...USED A BLEND OF SOLUTIONS FOR THE END OF THE WEEK. A REX BLOCK/HIGH OVER LOW PATTERN WILL TRAVERSE ACROSS THE GREAT PLAINS TUESDAY THROUGH THURSDAY. THIS WILL GENERATE DRY CONDITIONS AND A GRADUAL WARMING TREND ACROSS NORTH DAKOTA THROUGH MID-WEEK WITH HIGHS GENERALLY IN THE UPPER 60S TO LOWER 70S BY THURSDAY. MODEL SOLUTIONS BEGIN TO DIVERGE WITH RESPECT TO A POSSIBLE LATE SEASON WINTER STORM EXPECTED TO IMPACT THE REGION THURSDAY NIGHT THROUGH SATURDAY. THE MAIN QUESTIONS ARE WHEN EXACTLY THIS SYSTEM WILL BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA AND WHAT THE PRECIPITATION TYPE WILL BE. AS IS TYPICAL WITH HIGH IMPACT WEATHER SYSTEMS...THE ECMWF IS THE SLOWEST SOLUTION RELATIVE TO THE GFS/GEM. IT PAINTS QPF ACROSS WESTERN NORTH DAKOTA ALONG A STRONG BAROCLINIC ZONE FRIDAY AFTERNOON WHEREAS THE GFS/GEM IS ABOUT 12-18 HOURS FASTER BEGINNING PRECIP WEST THURSDAY NIGHT. WOULD LIKE TO SIDE WITH THE ECMWF GIVEN ITS SUPERIOR PERFORMANCE IN THE EXTENDED. HOWEVER...THE HIGH UNCERTAINTY WARRANTS A BROAD BRUSHING OF POPS FOR THE THURSDAY NIGHT THROUGH SATURDAY PERIOD WITH THE HIGHEST POPS WEST. AS THIS SYSTEM MOVES ACROSS THE STATE...ITS SURFACE REFLECTION IS PROGGED TO GENERATE VERY WINDY CONDITIONS ACROSS WESTERN AND CENTRAL NORTH DAKOTA DURING THE FRIDAY NIGHT/SATURDAY PERIOD. IN ADDITION...WRAP-AROUND MOISTURE COMBINED WITH 850MB TEMPERATURES FALLING BELOW ZERO SHOULD ALLOW FOR A WINTRY MIX OF PRECIPITATION TO DEVELOP FRIDAY NIGHT WITH PRIMARILY SNOW EXPECTED NORTHWEST BY SATURDAY. THE COMBINATION OF HIGH WINDS AND WINTRY PRECIPITATION COULD MAKE FOR AN INTERESTING WEEKEND. STAY TUNED. && .AVIATION... PRIMARILY VFR CONDITIONS ARE EXPECTED ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE TAF PERIOD. LIGHT SHOWERS WILL CONTINUE TO IMPACT KMOT THROUGH THE MORNING HOURS. EXPECT E/SE WINDS THIS MORNING AHEAD OF A STRONG FRONT THAT WILL SWEEP THROUGH NORTH DAKOTA TODAY. WINDS WILL BECOME W/NW BEHIND THE FRONT AND GUST AROUND 30 KTS IN THE AFTERNOON AT ALL SITES EXCEPT FOR KJMS. && .FIRE WEATHER... A COLD FRONT IS FORECAST TO ENTER FAR WESTERN NORTH DAKOTA NEAR MID DAY TODAY...AND PUSH AS FAR EAST AS NORTH DAKOTA HIGHWAY 3 BY LATE AFTERNOON. WIDESPREAD NEAR TO RECORDING BREAKING HIGH TEMPERATURES INTO THE MID TO UPPER 70S...TO PERHAPS THE LOWER 80S ARE FORECAST AHEAD OF THE COLD FRONT. BEHIND THE FRONT...GOOD MIXING SHOULD ALLOW FOR SUSTAINED WESTERLY WINDS TO 25 MPH WITH GUSTS APPROACHING 35 MPH...AS RH VALUES FALL TO 15 TO 25 PERCENT WITH TEMPERATURES STILL IN THE 60S AND 70S. THE FAR EASTERN TIER OF COUNTIES IN THE RED FLAG WARNING MAY NOT SEE FRONTAL PASSAGE UNTIL THE EARLY EVENING...AND THUS NOT MEET CRITERIA. HOWEVER...IT WILL BE CLOSE AND WILL LEAVE THE WARNING AS IS FOR NOW. FOR TONIGHT...STRONG WINDS MAY CONTINUE THROUGH MUCH OF THE OVERNIGHT...ESPECIALLY ACROSS THE SOUTHWEST AND SOUTH CENTRAL...WITH NORTHWEST WINDS OF SIMILIAR SPEEDS AS SEEN PRIOR TO SUNSET LASTING THROUGH THE NIGHT. MONDAY LOOKS TO BE COOLER AND BREEZY BEHIND THE FRONT WITH HIGHS IN THE 50S AND RH VALUES FALLING TO 20 TO 30 PERCENT FOR MOST AREAS WITH AFTERNOON MIXING. THE COOLER TEMPERATURES AND SLIGHTLY HIGHER RH VALUES WILL HELP TO LIMIT THE OVERALL THREAT. THE AREA OF MOST CONCERN FOR POSSIBLY REACHING CRITICAL VALUES IS THE FAR SOUTHWEST...WHERE STRONGER NORTHWEST WINDS OF 20 TO 30 MPH ARE POSSIBLE. HOWEVER...TO AVOID CONFUSION WITH THE CURRENT FIRE WEATHER HEADLINES...WILL LET THE DAY SHIFT EVALUATE FURTHER. && .BIS WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TODAY TO 10 PM CDT /9 PM MDT/ THIS EVENING FOR NDZ009>012-017>023-031>036-040>047-050. && $$ SHORT TERM/FIRE...AYD LONG TERM/AVIATION....TM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
310 AM CDT SUN APR 1 2012 .SHORT TERM (SUN-TUE)...INTERESTING FORECAST WITH MULTIPLE CHALLENGES. MODEL DIFFERENCES ARISE ON MONDAY WITH TIMING OF FRONT. GEM/ECMWF SLOW WHILE NAM/GFS QUICKER. ECMWF HAS BEEN CONSISTENT WITH THE SLOW SOLUTION...BUT HAD BEEN AN OUTLIER UNTIL THIS SET OF MODEL RUNS WITH THE GEM TRENDING SLOWER. WILL HAVE TO FOLLOW A BLEND. UPPER RIDGE BUILDING INTO THE REGION FOR TODAY. AHEAD OF THIS UPPER RIDGING...SCATTERED SHOWERS ASSOCIATED WITH WEAK WAVE (WARM AIR ADVECTION) POSSIBLE DURING THE EARLY MORNING HOURS...EXITING THE NE FA BY NOON. LOW-LEVEL FLOW IS INCREASING FROM THE SOUTHEAST...AND ADVECTING LOW LEVEL MOISTURE (LOW CLOUDS/FOG) BACK INTO THE REGION FROM CENTRAL MINNESOTA. FOLLOWING HRRR...EXPECT THESE CIGS TO ADVECT INTO ALL BUT THE FAR NORTHERN FA BY 12Z...THEN SCATTER WITH DAYTIME HEATING AND STRONG SE WINDS BY MID TO LATE MORNING. DENSE FOG POSSIBLE UNTIL MID-MORNING...AND WILL MONITOR CONDITIONS FOR POSSIBLE ADVISORY. SO FAR DENSE FOG IS NOT TOO WIDESPREAD...BUT HRRR SUGGESTS THAT DENSE FOG WILL BECOME WIDESPREAD BY 05Z. WINDS WILL BE CLOSE TO ADVISORY CRITERIA THIS AFTERNOON...BUT PARAMETERS SUGGEST JUST BELOW. WITH SOLAR AND GOOD MIXING...EXPECT FULL HEATING POTENTIAL...WITH MAX TEMPS AROUND 80F ACROSS THE SW FA TO UPPER 60S ACROSS THE NE FA. EXPECTED TEMP VALUES ALONG AND WEST OF THE VALLEY WILL BE RECORD HIGHS. UPPER RIDGING WILL BE BRIEF WITH UPPER FLOW BECOMING SOUTHWEST TONIGHT. STRONG 850MB JET WILL DEVELOP AND TRANSPORT MOISTURE ALONG AND AHEAD COLD FRONT. FOLLOWING MODEL COMPROMISE FOR TIMING...BEST PRECIP CHANCES WILL BE ALONG AND EAST OF THE VALLEY...FROM 06Z MON INTO THE AFTERNOON HOURS. 850MB CAPE 1000-1500 J/KG INTO THE EARLY MORNING ALONG WITH STRONG LOW-LEVEL JET ACROSS SE FA COULD LEAD TO ISOLD SEVERE HAIL (SPC HAS A 5% PROBABILITY)...ALTHOUGH DEEP LAYER SHEAR WILL BE MARGINAL. UPPER TROUGH SWINGS THROUGH BY MON NIGHT. AS THIS FEATURE APPROACHES CANNOT RULE OUT SHOWERS ANYWHERE ON MONDAY...BUT HEAVIEST RAINFALL SHOULD BE IN MINNESOTA COUNTIES (AHEAD OF COLD FRONT WHERE PWATS ARE HIGHEST). CLOUDS AND COOLER AIRMASS WILL LEAD TO MUCH COLDER TEMPS ON MONDAY (ALTHOUGH STILL ABOVE NORMAL). RIDGING MOVES BACK INTO THE REGION ON TUESDAY...AND TEMPS BEGIN TO TREND WARMER AGAIN. .LONG TERM (WED-SAT)...RIDGING DOMINATES INTO FRIDAY BEFORE MOVING TO THE EAST ALLOWING SW FLOW ALOFT. DRY AND WARM CONDITIONS SHOULD TRANSITION TO COOLER AND WETTER BY SATURDAY IF MODELS HAVE TIMING CORRECT. && .AVIATION...LIFR/IFR CIGS/VSBY WILL CONTINUE TO ADVECT NORTHEAST FROM WEST CENTRAL MINNESOTA INTO THE EARLY MORNING HOURS. THE MAIN QUESTION WILL BE HOW FAR TO THE NORTH/WEST THESE CONDITIONS WILL ADVECT. CURRENT HI-RES MODEL GUIDANCE SUGGESTS THAT A SURE BET WILL BE KBJI AND KFAR...WHILE KGFK AND KTVF WILL BE ON THE EDGE...AND KDVL SHOULD REMAIN VFR. MOST GUIDANCE SUGGESTS ALL SITES VFR BY 18Z. GUSTY SOUTHEAST WINDS EXPECTED TO DEVELOP BY AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ TG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
656 PM EDT SUN APR 1 2012 .SYNOPSIS... HIGH PRESSURE NORTH OF LAKE SUPERIOR WILL BUILD SOUTHEAST INTO THE AREA TONIGHT THEN SHIFT OFF TO THE EAST TUESDAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE REGION LATE TUESDAY THEN HIGH PRESSURE WILL SPREAD SOUTHEAST INTO THE AREA BY WEDNESDAY NIGHT AND BECOMES NEARLY STATIONARY INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... SHOWERS AND A FEW EMBEDDED THUNDERSTORMS CONTINUE ALONG A CORRIDOR THROUGH THE CENTRAL PORTION OF THE FORECAST AREA. THIS IS WELL ALIGNED WITH THE GFS MODEL. THE GFS SHOWS A SMALL AREA OF POSITIVE VORTICITY ADVECTION AND ASSOCIATED VORTICITY MAXIMUM MOVING SOUTHEAST INTO THE AREA. A SWATH OF MOISTURE IS ALSO MOVING SOUTHEAST INTO THE AREA AND HENCE THE PRECIPITATION. THE WHOLE AREA WILL MOVE SOUTHWEST WITH TIME AS 500 MB LOW PRESSURE SYSTEM RETROGRADES SOUTHWEST INTO THE AREA. THIS WILL HELP TO AMPLIFY THE 500 MB RIDGE WEST OF THE FORECAST AREA FORCING AXIS OF PRECIPITATION TO SHIFT WEST AS WELL. I WILL KEEP A MENTION OF THUNDER JUST IN CASE A RENEGADE CELL DEVELOPS. I THINK THE THREAT FOR THUNDER WILL CONTINUE TO DIMINISH AS THE SUN SETS THIS EVENING. COLD AIR ADVECTION CONTINUES TO PUSH SOUTH AND HAS REACHED THE EXTREME NORTHEAST PORTIONS OF THE FORECAST AREA BEHIND THE COLD FRONT. CURRENT FORECAST TEMPERATURES LOOK REASONABLE AT THIS TIME. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/... THE RIDGE OF HIGH PRESSURE OVER THE AREA SHOULD KEEP CONDITIONS DRY INTO MON EVENING. A WEAKENING LOW ALONG A COLD FRONT WILL CROSS THE AREA TUESDAY. MODELS HAVE BACKED DOWN ON OVERALL QPF FOR THIS EVENT BUT STILL THINK MOST PLACES WILL SEE SOMETHING AT SOME POINT FROM LATE MON NIGHT INTO TUE EVENING. AIRMASS CONTINUES TO LOOK UNSTABLE ENOUGH FOR TSRA. ANOTHER HIGH RIDGES SOUTH INTO THE CWA TUE NIGHT THROUGH WED BRINGING DRIER AIR AND SHOULD END MOST OF THE SHRA THREAT FROM NORTH TO SOUTH TUE EVENING. RIDGING REMAINS OVER AREA AND SHOULD KEEP DRY WEATHER IN PLACE THROUGH THU NIGHT. HOWEVER...LATEST GFS NOW TRYING TO BRING CUTOFF UPPER LOW CLOSER TO SW OH SO THIS WILL NEED TO BE WATCHES NEXT FEW MODEL RUNS TO SEE IF THIS WILL TURN INTO A TYPICAL SPRINGTIME UPPER LOW THAT FINDS A HOME IN OHIO. WILL HAVE TO WATCH FOR FROST OR FREEZE THREAT FOR WED AND THU NIGHT BUT RIGHT NOW LOOKS LIKE NORTH TO NE WINDS WILL STAY UP ENOUGH TO KEEP FROST AWAY SO REAL CONCERN WILL BE WHERE TEMPS MAY TRY TO DROP TO 32 OR LESS IN THE INLAND EAST THESE NIGHTS. SOME MOISTURE DROPS SOUTH INTO THE SNOWBELT AREA FOR LATER WED NIGHT THROUGH THU NIGHT AND COULD RESULT IN ENOUGH LAKE EFFECT CLOUDS TO KEEP TEMPS FROM GETTING DOWN TO 32...THEREFORE A LOT OF UNCERTAINTY AS TO HOW LOW TEMPS WILL GO WED AND THU NIGHT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... THE FORECASTS REMAIN CONSISTENT WITH A RIDGE ACROSS THE AREA FOR FRIDAY AND SATURDAY. HOWEVER...A SYSTEM IS MOVING JUST TO THE SOUTH OF THE REGION...THIS WILL HAVE TO BE WATCHED. AT THIS TIME IT SEEMS LIKE THE RIDGE WILL BE STRONG ENOUGH TO KEEP IT SOUTH. FOR SUNDAY AND SUNDAY NIGHT A FRONT WILL BE MOVING THROUGH. TIMING IS ON THE EDGE. DID INCLUDE A CHANCE WEST SUNDAY AND MUCH OF THE AREA SUNDAY NIGHT. TEMPERATURES WILL MODERATE AS THE RIDGE MOVES SLOWLY EAST. WENT CLOSE TO HPC GUIDANCE FOR TEMPERATURE. DEPENDING ON THE STRENGTH OF THE NORTHERLY FLOW IT WILL HELP KEEP TEMPERATURES COOLER ALONG THE LAKESHORE AT TIMES. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... FRONTAL SYSTEMS AND LOW HEADED TOWARD THE FORECAST AREA FOR THE AFTERNOON AND EVENING. THE FRONTS SEEM DIFFUSE SO THE WINDS WILL PROBABLY JUST SHIFT ONCE THE LOW MOVES THROUGH. ATTM NOT THAT EXCITED ABOUT A LOT OF THUNDERSTORM ACTIVITY AS MOST OF THE UNSTABLE AIR WILL BE NEAR AND SOUTH OF THE SOUTHERN PORTION OF THE FORECAST AREA. THE CLOUDS WILL BE IN AND OUT THROUGH MID AFTERNOON BUT THE TREND WILL BE FOR CLOUDS MOVING BACK IN FROM THE NORTHWEST. THE WINDS WILL SHIFT FROM THE SOUTHWEST TO NORTHWEST AND THEN TO NORTHEAST BY THIS EVENING. AS THIS HAPPENS AREAS OF MVFR CEILINGS AND MAY BE EVEN SOME IFR THINGS WILL DEVELOP. AT THIS TIME IT LOOKS LIKE IT SHOULD BE DRY TONIGHT. THE HRRR MODEL IS INDICATING SOME SHOWERS...BUT ATTM THEY ARE NOT REACHING THE GROUND. THE FORECAST IS FOR THE CLOUDS TO MOVE OUT OF THE REGION BY DAYBREAK MONDAY. CONFIDENCE IN THIS IS FAIR. .OUTLOOK...NON VFR POSSIBLE TUESDAY AND TUESDAY EVENING. && .MARINE... A LOW WILL BE MOVING ACROSS NORTHERN OHIO AND NORTHWEST PA THROUGH THIS EVENING AND THIS WILL BRING THE WINDS AROUND FROM THE SOUTHWEST TO NORTHEAST BETWEEN DARK AND MIDNIGHT. AS THIS HAPPENS THE WINDS AND WAVES WILL PICK UP...THUS ISSUED A SMALL CRAFT ADVISORY FOR LAKE ERIE STARTING AT 8 PM AND LASTING UNTIL NOON MONDAY. AFTER THAT A RIDGE WILL BUILD IN BRIEFLY FOR MONDAY EVENING DECREASING THE WINDS AND WAVES AND THEN IT WILL MOVE EAST. FOR LATE TUESDAY THROUGH FRIDAY A THREAT FOR SMALL CRAFT ADVISORIES AT TIMES WILL OCCUR. ANOTHER LOW WILL MOVE ACROSS OHIO LATE TUESDAY AND THIS IN COMBINATION WITH A RIDGE BUILDING BACK IN THE WINDS AND WAVES COULD BE CLOSE TO SMALL CRAFT ADVISORY CRITERIA. ON FRIDAY ANOTHER LOW WILL MOVE THROUGH THE TENNESSEE VALLEY AND THIS IN COMBINATION WITH THE RIDGE OVER LAKE ERIE WILL CAUSE A NORTHEAST FLOW AND IT COULD BE STRONG ENOUGH TO CAUSE WAVES TO BE 3 TO 5 FEET. ALL THIS WILL BE WATCHED CLOSELY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT MONDAY FOR LEZ142>149. && $$ SYNOPSIS...ADAMS NEAR TERM...LOMBARDY SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
325 PM EDT SUN APR 1 2012 .SYNOPSIS... HIGH PRESSURE NORTH OF LAKE SUPERIOR WILL BUILD SOUTHEAST INTO THE AREA TONIGHT THEN SHIFT OFF TO THE EAST TUESDAY. A COLD FRONT WILL MOVE SOUTHEAST ACROSS THE REGION LATE TUESDAY THEN HIGH PRESSURE WILL SPREAD SOUTHEAST INTO THE AREA BY WEDNESDAY NIGHT AND BECOMES NEARLY STATIONARY INTO NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... DRIER AIR PUSHING SOUTH BEHIND THE COLD FRONT WILL PUSH THE THREAT OF SHRA SOUTH OF THE CWA DURING THE EVENING OR CERTAINLY BY 1 TO 2 AM. SOME LAKE EFFECT CLOUDS MAY OCCUR BUT OVERALL LAKE EFFECT CONDITIONS DO NOT APPEAR STRONG ENOUGH TO OFFSET STRONG SUBSIDENCE OCCURRING AS HIGH PRESSURE RIDGES SOUTH INTO THE AREA. ANOTHER COOL NIGHT WITH TEMPS IN THE EAST CLOSE TO FREEZING POINT BY DAYBREAK. HOWEVER...THINK JUST ENOUGH WIND WILL CONTINUE THROUGH THE NIGHT TO KEEP FROST FROM FORMING SO NO ADVISORY PLANNED. && .SHORT TERM /MONDAY THROUGH THURSDAY NIGHT/... THE RIDGE OF HIGH PRESSURE OVER THE AREA SHOULD KEEP CONDITIONS DRY INTO MON EVENING. A WEAKENING LOW ALONG A COLD FRONT WILL CROSS THE AREA TUESDAY. MODELS HAVE BACKED DOWN ON OVERALL QPF FOR THIS EVENT BUT STILL THINK MOST PLACES WILL SEE SOMETHING AT SOME POINT FROM LATE MON NIGHT INTO TUE EVENING. AIRMASS CONTINUES TO LOOK UNSTABLE ENOUGH FOR TSRA. ANOTHER HIGH RIDGES SOUTH INTO THE CWA TUE NIGHT THROUGH WED BRINGING DRIER AIR AND SHOULD END MOST OF THE SHRA THREAT FROM NORTH TO SOUTH TUE EVENING. RIDGING REMAINS OVER AREA AND SHOULD KEEP DRY WEATHER IN PLACE THROUGH THU NIGHT. HOWEVER...LATEST GFS NOW TRYING TO BRING CUTOFF UPPER LOW CLOSER TO SW OH SO THIS WILL NEED TO BE WATCHES NEXT FEW MODEL RUNS TO SEE IF THIS WILL TURN INTO A TYPICAL SPRINGTIME UPPER LOW THAT FINDS A HOME IN OHIO. WILL HAVE TO WATCH FOR FROST OR FREEZE THREAT FOR WED AND THU NIGHT BUT RIGHT NOW LOOKS LIKE NORTH TO NE WINDS WILL STAY UP ENOUGH TO KEEP FROST AWAY SO REAL CONCERN WILL BE WHERE TEMPS MAY TRY TO DROP TO 32 OR LESS IN THE INLAND EAST THESE NIGHTS. SOME MOISTURE DROPS SOUTH INTO THE SNOWBELT AREA FOR LATER WED NIGHT THROUGH THU NIGHT AND COULD RESULT IN ENOUGH LAKE EFFECT CLOUDS TO KEEP TEMPS FROM GETTING DOWN TO 32...THEREFORE A LOT OF UNCERTAINTY AS TO HOW LOW TEMPS WILL GO WED AND THU NIGHT. && .LONG TERM /FRIDAY THROUGH SUNDAY/... THE FORECASTS REMAIN CONSISTENT WITH A RIDGE ACROSS THE AREA FOR FRIDAY AND SATURDAY. HOWEVER...A SYSTEM IS MOVING JUST TO THE SOUTH OF THE REGION...THIS WILL HAVE TO BE WATCHED. AT THIS TIME IT SEEMS LIKE THE RIDGE WILL BE STRONG ENOUGH TO KEEP IT SOUTH. FOR SUNDAY AND SUNDAY NIGHT A FRONT WILL BE MOVING THROUGH. TIMING IS ON THE EDGE. DID INCLUDE A CHANCE WEST SUNDAY AND MUCH OF THE AREA SUNDAY NIGHT. TEMPERATURES WILL MODERATE AS THE RIDGE MOVES SLOWLY EAST. WENT CLOSE TO HPC GUIDANCE FOR TEMPERATURE. DEPENDING ON THE STRENGTH OF THE NORTHERLY FLOW IT WILL HELP KEEP TEMPERATURES COOLER ALONG THE LAKESHORE AT TIMES. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... FRONTAL SYSTEMS AND LOW HEADED TOWARD THE FORECAST AREA FOR THE AFTERNOON AND EVENING. THE FRONTS SEEM DIFFUSE SO THE WINDS WILL PROBABLY JUST SHIFT ONCE THE LOW MOVES THROUGH. ATTM NOT THAT EXCITED ABOUT A LOT OF THUNDERSTORM ACTIVITY AS MOST OF THE UNSTABLE AIR WILL BE NEAR AND SOUTH OF THE SOUTHERN PORTION OF THE FORECAST AREA. THE CLOUDS WILL BE IN AND OUT THROUGH MID AFTERNOON BUT THE TREND WILL BE FOR CLOUDS MOVING BACK IN FROM THE NORTHWEST. THE WINDS WILL SHIFT FROM THE SOUTHWEST TO NORTHWEST AND THEN TO NORTHEAST BY THIS EVENING. AS THIS HAPPENS AREAS OF MVFR CEILINGS AND MAY BE EVEN SOME IFR THINGS WILL DEVELOP. AT THIS TIME IT LOOKS LIKE IT SHOULD BE DRY TONIGHT. THE HRRR MODEL IS INDICATING SOME SHOWERS...BUT ATTM THEY ARE NOT REACHING THE GROUND. THE FORECAST IS FOR THE CLOUDS TO MOVE OUT OF THE REGION BY DAYBREAK MONDAY. CONFIDENCE IN THIS IS FAIR. .OUTLOOK...NON VFR POSSIBLE TUESDAY AND TUESDAY EVENING. && .MARINE... A LOW WILL BE MOVING ACROSS NORTHERN OHIO AND NORTHWEST PA THROUGH THIS EVENING AND THIS WILL BRING THE WINDS AROUND FROM THE SOUTHWEST TO NORTHEAST BETWEEN DARK AND MIDNIGHT. AS THIS HAPPENS THE WINDS AND WAVES WILL PICK UP...THUS ISSUED A SMALL CRAFT ADVISORY FOR LAKE ERIE STARTING AT 8 PM AND LASTING UNTIL NOON MONDAY. AFTER THAT A RIDGE WILL BUILD IN BRIEFLY FOR MONDAY EVENING DECREASING THE WINDS AND WAVES AND THEN IT WILL MOVE EAST. FOR LATE TUESDAY THROUGH FRIDAY A THREAT FOR SMALL CRAFT ADVISORIES AT TIMES WILL OCCUR. ANOTHER LOW WILL MOVE ACROSS OHIO LATE TUESDAY AND THIS IN COMBINATION WITH A RIDGE BUILDING BACK IN THE WINDS AND WAVES COULD BE CLOSE TO SMALL CRAFT ADVISORY CRITERIA. ON FRIDAY ANOTHER LOW WILL MOVE THROUGH THE TENNESSEE VALLEY AND THIS IN COMBINATION WITH THE RIDGE OVER LAKE ERIE WILL CAUSE A NORTHEAST FLOW AND IT COULD BE STRONG ENOUGH TO CAUSE WAVES TO BE 3 TO 5 FEET. ALL THIS WILL BE WATCHED CLOSELY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON EDT MONDAY FOR LEZ142>149. && $$ SYNOPSIS...ADAMS NEAR TERM...TK SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
150 PM EDT SUN APR 1 2012 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES TODAY. A WARM FRONT WILL MOVE INTO THE AREA AHEAD OF THE LOW...FOLLOWED QUICKLY BY A COLD FRONT. HIGH PRESSURE OVER ONTARIO WILL EXTEND ACROSS THE EASTERN GREAT LAKES INTO THE OHIO VALLEY TONIGHT AND MONDAY. THE HIGH WILL MOVE EAST TUESDAY AND ALLOW LOW PRESSURE TO DRIFT IN FROM THE WEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... GENERAL THINKING FROM PREVIOUS UPDATE (BELOW) REMAINS ON TRACK. ONLY CHANGES ARE FOR CURRENT CONDITIONS AND BLENDING. COLD FRONT SAGGING SOUTH ACROSS MUCH OF THE CWA THIS AFTERNOON INTO EARLY EVENING STILL WELL NORTH OF THE CWA SO THINK MORE OF A SOUTH TO SW FLOW SHOULD DOMINATE UNTIL AT LEAST 19Z TO 20Z THEN SHIFT TO NW AND NORTH SHOULD START NEAR LERI AND PUSH SOUTH REST OF AFTERNOON AND EVENING. AS AIRMASS DESTABILIZES MORE WITH HEAT OF THE DAY EXPECT MORE CONVECTION TO DEVELOP SO AS FRONT PUSHES THROUGH STILL SEE A GOOD CHANCE FOR MOST AREAS. COULD BE SOME STRONG STORMS IN THE FAR SW BUT THE SEVERE THREAT SHOULD STAY SW OF THE AREA WHERE MORE UNSTABLE AIR EXISTS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... 00Z THIS EVENING THE COLD FRONT SHOULD BE ACROSS SOUTHERN OHIO WITH DRY AIR MOVING INTO THE AREA FROM THE NORTH. ENDED PRECIP QUICKLY ALTHOUGH DID HOLD ONTO CHANCE POPS...HIGHEST SOUTH...THIS EVENING TO COVER ANY LINGERING PRECIP. BY 03Z HOWEVER NAM SHOWS DRY AIR IN PLACE AND POSITIVE CAPES WELL SOUTH OF THE AREA. OVERNIGHT HIGH PRESSURE WILL CONTINUE TO BUILD IN. PAST TWO HIGHS HAVE NOT MANAGED TO CLEAR OUT THE STRATUS BUT BUFKIT SHOWS DRIER AIR WILL BE MOVING IN SO WILL GO AHEAD AND BUY INTO THE CLEARING. MONDAY...HIGH PRESSURE WILL CONTINUE OVER THE AREA ALTHOUGH WINDS WILL BE FROM THE NORTH/NORTHEAST. EXPECT LAKESHORE AREAS TO REMAIN CHILLY VS INLAND. ALSO EXPECT A SIZABLE TEMP GRADIENT FROM NORTHEAST TO SOUTHWEST WITH 850MB TEMPS 0 TO 2C OVER ERIE IN THE AFTERNOON AND 8 TO 10C OVER FDY. TUESDAY THE HIGH WILL MOVE EAST AND LOW PRESSURE WILL MOVE IN FROM THE WEST. 850MB TEMPS RISE TO 14C WITH ALL OF THE AREA IN THE WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT. EXPECTING A MILD AFTERNOON ALTHOUGH WITH CAPES SHOWN ON THE NAM AROUND 2000 J/KG WILL LIKELY BE STORMY SO WEST ABOVE GUIDANCE WITH LIKELY POPS FOR THUNDERSTORMS. MUCH DRIER AIR MOVES IN DURING THE EVENING POST COLD FRONT AND BY MORNING...IF SKIES CLEAR COULD SEE ANOTHER ROUND OF FROST. WEDNESDAY AND WED NIGHT WILL BE DRY WITH NEAR NORMAL TEMPS. && .LONG TERM /THURSDAY THROUGH SATURDAY/... GFS AND ECMWF HAVE INCREASED IN SIMILARITY OVER THE PAST DAY TO BRING STRONGER CONFIDENCE IN SHOWING HIGH PRESSURE OVER THE GREAT LAKES WILL DOMINATE ACROSS THE FORECAST AREA THROUGH THE SECOND HALF OF THE UPCOMING WEEK. THIS WILL ALLOW FOR DRY CONDITIONS AND SEASONABLE TEMPERATURES. AS PREVIOUSLY MENTIONED...THE NORTH FLOW OFF THE LAKE OR DEVELOPING LAKE BREEZES WITH A LIGHT GRADIENT...WILL CAUSE FOR AT LEAST SEASONABLE TEMPERATURES ACROSS THE INTERIOR BUT COOLER MAXES ALONG THE LAKESHORE. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... FRONTAL SYSTEMS AND LOW HEADED TOWARD THE FORECAST AREA FOR THE AFTERNOON AND EVENING. THE FRONTS SEEM DIFFUSE SO THE WINDS WILL PROBABLY JUST SHIFT ONCE THE LOW MOVES THROUGH. ATTM NOT THAT EXCITED ABOUT A LOT OF THUNDERSTORM ACTIVITY AS MOST OF THE UNSTABLE AIR WILL BE NEAR AND SOUTH OF THE SOUTHERN PORTION OF THE FORECAST AREA. THE CLOUDS WILL BE IN AND OUT THROUGH MID AFTERNOON BUT THE TREND WILL BE FOR CLOUDS MOVING BACK IN FROM THE NORTHWEST. THE WINDS WILL SHIFT FROM THE SOUTHWEST TO NORTHWEST AND THEN TO NORTHEAST BY THIS EVENING. AS THIS HAPPENS AREAS OF MVFR CEILINGS AND MAY BE EVEN SOME IFR THINGS WILL DEVELOP. AT THIS TIME IT LOOKS LIKE IT SHOULD BE DRY TONIGHT. THE HRRR MODEL IS INDICATING SOME SHOWERS...BUT ATTM THEY ARE NOT REACHING THE GROUND. THE FORECAST IS FOR THE CLOUDS TO MOVE OUT OF THE REGION BY DAYBREAK MONDAY. CONFIDENCE IN THIS IS FAIR. .OUTLOOK...NON VFR POSSIBLE TUESDAY AND TUESDAY EVENING. && .MARINE... SFC HIGH PRESSURE OVER THE LAKE THIS MORNING WILL MOVE TO THE EAST THIS MORNING AS A LOW PRESSURE AND COLD FRONT CROSS THE LAKE THIS AFTERNOON AND EVENING. THIS WILL SHIFT WINDS FROM SOUTHERLY TODAY TO NORTH AND NORTHEAST TONIGHT. WILL HAVE TO WATCH FOR SMALL CRAFT ADVISORY POTENTIAL...BUT LOOKS LIKE THE GRADIENT WILL BE LIGHT ENOUGH TO KEEP WINDS AROUND 15KT AND WAVES AROUND 3 FEET. THE NEXT LOW PRESSURE EXPECTED TO MOVE ACROSS THE LAKE ON TUESDAY. HOWEVER...AGAIN THIS SYSTEM LOOKS BE ON THE WEAKER SIDE ALSO. WHILE WINDS WILL SHIFT FROM SOUTH TO NORTHERLY BETWEEN TUESDAY MORNING AND TUESDAY NIGHT...CONDITIONS MAY ALSO REMAIN JUST BELOW SMALL CRAFT CRITERIA. HIGH PRESSURE TO THE NORTH WILL DOMINATE OVER THE LAKE BY WEDNESDAY AND PERSIST THROUGH THE WEEK. WITH HIGH PRESSURE RIDGING SOUTH OVER THE LAKE DURING THE SECOND HALF OF THE WEEK...THE IS THE CHANCE FOR A PERIOD OF SMALL CRAFT CONDITIONS WEDNESDAY OR THURSDAY BEFORE IT BECOMES SETTLED OVER THE LAKE FOR THE END OF THE WEEK. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...TK NEAR TERM...ADAMS SHORT TERM...TK LONG TERM...ABE AVIATION...ADAMS MARINE...ABE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
135 PM EDT SUN APR 1 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL DROP SOUTH INTO THE OHIO VALLEY TODAY OFFERING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS FRONT WILL PUSH INTO THE TENNESSEE VALLEY WITH SURFACE HIGH PRESSURE PROVIDING A TEMPORARY DRY PERIOD ON MONDAY. THIS FRONT IS EXPECTED TO RETURN BRINGING ADDITIONAL THUNDERSTORMS MONDAY NIGHT INTO TUESDAY. && .NEAR TERM /UNTIL 9 PM THIS EVENING/... DECAYING MCS WILL BRING A CHANCE FOR SHOWERS MAINLY WEST OF I-75 THROUGH THE LATE MORNING. GRADUAL CLEARING BEHIND THIS FEATURE...COMBINED WITH AMPLE WARM/MOISTURE ADVECTION FROM THE SOUTHWEST ASSOCIATED WITH A WARM FRONT WILL LEAD TO TEMPERATURES INTO THE LOW TO MID 70S ACROSS THE MAJORITY OF THE AREA BY LATE THIS AFTERNOON. NORTHWESTERLY FLOW ALOFT WILL INTENSIFY LATER TODAY AROUND THE PERIPHERY A MID/UPPER LEVEL RIDGE BUILDING ACROSS THE PLAINS. AT THE SAME TIME...A SHORTWAVE TROUGH WILL DROP ACROSS THE EASTERN GREAT LAKES. THIS SHORTWAVE WILL DEVELOP A BACK DOOR COLD FRONT WHICH WILL PUSH TOWARD THE OHIO VALLEY THIS EVENING. AHEAD OF THIS FRONT...AN INCREASINGLY UNSTABLE BOUNDARY LAYER WILL COMBINE WITH DEEP SHEAR TO DEVELOP THUNDERSTORMS ACROSS OUR AREA LATE THIS AFTERNOON AND INTO THE EVENING. SOME OF THESE STORMS HAVE THE POTENTIAL TO BECOME SEVERE. THE MAIN THREAT FROM THESE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS. HOWEVER...CANNOT RULE OUT AN ISOLATED TORNADO. OVERALL...CONVECTION WILL INITIATE ACROSS THE NORTH LATE THIS AFTERNOON...AND PUSH SSE ACROSS OUR SOUTH THIS EVENING WITH THE MEAN FLOW. HAVE FAVORED THE 12Z RUC FOR THIS UPDATE FOR TEMPS AND STORM TIMING. && .SHORT TERM /9 PM THIS EVENING THROUGH TUESDAY/... A BACK DOOR TYPE COLD FRONT TO DROP SOUTH THRU THE OHIO VALLEY AND STALL OUT OVER THE TN VLY OVERNIGHT. WL BUMP POPS UP TO LKLY EARLY ACRS THE SE WHERE BEST FORCING WL EXIST AND THEN TAPER PRECIP OFF FROM NORTH TO SOUTH. SOME OF THE STORMS MAY BE SEVERE DURING INTO THE EARLY EVENING HOURS WITH THE MAIN THREATS BEING WIND AND HAIL. SFC HIGH PRESSURE WILL BRIEFLY BUILD INTO THE FA MONDAY PROVIDING A TEMPORARY DRY PERIOD. HAVE TRENDED MONDAYS HIGHS A LTL COOLER ON MONDAY...FROM THE MID 60S NE TO THE MID/UPR 70S SOUTHWEST. THE MID LEVEL RIDGE WL BUILD E INTO THE REGION WITH UPPER LEVEL DISTURBANCE PASSING THRU THE GREAT LAKES TUESDAY. ASSOCIATED SFC WAVE TO TRACK THRU THE SRN GREAT LAKES. FRONT BOUNDARY TO PIVOT BACK NORTHEAST AS A WARM FRONT LATE MON NIGHT/TUE AND THEN COLD FRONT TO DROP BACK DOWN THRU THE OHIO VALLEY TUES NIGHT. NUMERICAL MODELS ARE NOT IN AGREEMENT REGARDING THIS SYSTEM AND HOW ACTIVE THE INITIAL WARM FRONT WL BE LATE MONDAY NIGHT/TUES. HAVE CHANCE/SLIGHT POPS RE-DEVELOPING LATE WITH THE BEST PROBABILITY ACRS W CENTRAL OHIO. THEN ALLOW CHC POPS TO LAY OUT E-W ON TUESDAY WITH THE APPROACH OF FRONT. CONFIDENCE IS NOT HIGH REGARDING PRECIP CHANCES TUESDAY. ETA/GFS SOLNS ARE FASTER BRINGING THE FRONT IN...WHICH THE ECMWF HOLDS IT BACK. GOING WITH A SLIGHTLY SLOWER SOLN HAVE WARM TEMPS WITH TUESDAYS FCST HIGHS RANGING FROM THE LOWER 70S FAR N TO AROUND 80 SOUTH. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... HAVE FAVORED NON-GFS SOLUTION EARLY ON. THIS WOULD LEAD TO A SLOWER PROGRESSION OF A FRONT AND ASSOCIATED PRECIPITATION. HOWEVER THERE COULD BE SOME ELEVATED SHOWERS AND THUNDERSTORMS TUESDAY MORNING WELL AHEAD OF THE FRONT. BUT MOST STORMS SHOULD HOLD OFF UNTIL LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT AS THE FRONT MOVES THROUGH. THIS BOUNDARY WILL STALL IN THE TENNESSEE VALLEY AS HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES ON WEDNESDAY. A CLOSED LOW WILL PASS SOUTH OF THE REGION ON THURSDAY AND THURSDAY NIGHT WHICH MAY SPREAD SHOWERS AND THUNDERSTORMS BACK INTO THE SOUTHERN ZONES. AFTER THIS PASSES HIGH PRESSURE WILL BE ABLE TO BUILD SOUTH OVER THE REGION FOR THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES AT THE BEGINNING OF THE PERIOD WILL TREND TOWARDS NORMAL BY LATER IN THE WEEK. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AFTER CLEARING DURING THE EARLY AFTERNOON...THUNDERSTORMS WILL DEVELOP OUT AHEAD OF A BACK DOOR COLD FRONT LATE THIS AFTERNOON. THESE STORMS WILL LIKELY AFFECT ALL TERMINALS DURING THE EVENING HOURS. EXACT TIMING IS STILL A BIT UNCERTAIN FOR THE ARRIVAL OF THESE STORMS...THEREFORE HAVE KEPT ANY TEMPOS OUT OF THE FORECAST FOR NOT. THESE WILL LIKELY BE ADDED IN AMENDMENTS LATER ON...AFTER THE STORMS ACTUALLY DEVELOP. REGARDLESS...MVFR/IFR VSBYS WILL BE POSSIBLE IN HEAVIER STORMS. WINDS WILL START OF SOUTHWESTERLY...THEN WILL VEER AS THE STORMS PUSH ACROSS THE AREA...AND THE COLD FRONT MOVES THROUGH OVERNIGHT. BY MONDAY MORNING...WINDS WILL BE NORTHEASTERLY AT 5 TO 10 KT. THERE MAY BE A BRIEF PERIOD AFTER FRONTAL PASSAGE OVERNIGHT TONIGHT WHERE CIGS DROP BELOW 3 KFT AS WELL. VFR CONDITIONS ARE EXPECTED DURING THE DAY MONDAY. OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY NIGHT INTO TUESDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...AR NEAR TERM...LATTO SHORT TERM...AR LONG TERM... AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1040 AM EDT SUN APR 1 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL DROP SOUTH INTO THE OHIO VALLEY TODAY OFFERING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS FRONT WILL PUSH INTO THE TENNESSEE VALLEY WITH SURFACE HIGH PRESSURE PROVIDING A TEMPORARY DRY PERIOD ON MONDAY. THIS FRONT IS EXPECTED TO RETURN BRINGING ADDITIONAL THUNDERSTORMS MONDAY NIGHT INTO TUESDAY. && .NEAR TERM /UNTIL 9 PM THIS EVENING/... DECAYING MCS WILL BRING A CHANCE FOR SHOWERS MAINLY WEST OF I-75 THROUGH THE LATE MORNING. GRADUAL CLEARING BEHIND THIS FEATURE...COMBINED WITH AMPLE WARM/MOISTURE ADVECTION FROM THE SOUTHWEST ASSOCIATED WITH A WARM FRONT WILL LEAD TO TEMPERATURES INTO THE LOW TO MID 70S ACROSS THE MAJORITY OF THE AREA BY LATE THIS AFTERNOON. NORTHWESTERLY FLOW ALOFT WILL INTENSIFY LATER TODAY AROUND THE PERIPHERY A MID/UPPER LEVEL RIDGE BUILDING ACROSS THE PLAINS. AT THE SAME TIME...A SHORTWAVE TROUGH WILL DROP ACROSS THE EASTERN GREAT LAKES. THIS SHORTWAVE WILL DEVELOP A BACK DOOR COLD FRONT WHICH WILL PUSH TOWARD THE OHIO VALLEY THIS EVENING. AHEAD OF THIS FRONT...AN INCREASINGLY UNSTABLE BOUNDARY LAYER WILL COMBINE WITH DEEP SHEAR TO DEVELOP THUNDERSTORMS ACROSS OUR AREA LATE THIS AFTERNOON AND INTO THE EVENING. SOME OF THESE STORMS HAVE THE POTENTIAL TO BECOME SEVERE. THE MAIN THREAT FROM THESE STORMS WILL BE LARGE HAIL AND DAMAGING WINDS. HOWEVER...CANNOT RULE OUT AN ISOLATED TORNADO...PARTICULARLY IF STORMS INTERACT WITH OTHER OUTFLOW BOUNDARIES. OVERALL...CONVECTION WILL INITIATE ACROSS THE NORTH LATE THIS AFTERNOON...AND PUSH SSE ACROSS OUR SOUTH THIS EVENING WITH THE MEAN FLOW. HAVE FAVORED THE 12Z RUC FOR THIS UPDATE FOR TEMPS AND STORM TIMING. && .SHORT TERM /9 PM THIS EVENING THROUGH TUESDAY/... A BACK DOOR TYPE COLD FRONT TO DROP SOUTH THRU THE OHIO VALLEY AND STALL OUT OVER THE TN VLY OVERNIGHT. WL BUMP POPS UP TO LKLY EARLY ACRS THE SE WHERE BEST FORCING WL EXIST AND THEN TAPER PRECIP OFF FROM NORTH TO SOUTH. SOME OF THE STORMS MAY BE SEVERE DURING INTO THE EARLY EVENING HOURS WITH THE MAIN THREATS BEING WIND AND HAIL. SFC HIGH PRESSURE WILL BRIEFLY BUILD INTO THE FA MONDAY PROVIDING A TEMPORARY DRY PERIOD. HAVE TRENDED MONDAYS HIGHS A LTL COOLER ON MONDAY...FROM THE MID 60S NE TO THE MID/UPR 70S SOUTHWEST. THE MID LEVEL RIDGE WL BUILD E INTO THE REGION WITH UPPER LEVEL DISTURBANCE PASSING THRU THE GREAT LAKES TUESDAY. ASSOCIATED SFC WAVE TO TRACK THRU THE SRN GREAT LAKES. FRONT BOUNDARY TO PIVOT BACK NORTHEAST AS A WARM FRONT LATE MON NIGHT/TUE AND THEN COLD FRONT TO DROP BACK DOWN THRU THE OHIO VALLEY TUES NIGHT. NUMERICAL MODELS ARE NOT IN AGREEMENT REGARDING THIS SYSTEM AND HOW ACTIVE THE INITIAL WARM FRONT WL BE LATE MONDAY NIGHT/TUES. HAVE CHANCE/SLIGHT POPS RE-DEVELOPING LATE WITH THE BEST PROBABILITY ACRS W CENTRAL OHIO. THEN ALLOW CHC POPS TO LAY OUT E-W ON TUESDAY WITH THE APPROACH OF FRONT. CONFIDENCE IS NOT HIGH REGARDING PRECIP CHANCES TUESDAY. ETA/GFS SOLNS ARE FASTER BRINGING THE FRONT IN...WHICH THE ECMWF HOLDS IT BACK. GOING WITH A SLIGHTLY SLOWER SOLN HAVE WARM TEMPS WITH TUESDAYS FCST HIGHS RANGING FROM THE LOWER 70S FAR N TO AROUND 80 SOUTH. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... HAVE FAVORED NON-GFS SOLUTION EARLY ON. THIS WOULD LEAD TO A SLOWER PROGRESSION OF A FRONT AND ASSOCIATED PRECIPITATION. HOWEVER THERE COULD BE SOME ELEVATED SHOWERS AND THUNDERSTORMS TUESDAY MORNING WELL AHEAD OF THE FRONT. BUT MOST STORMS SHOULD HOLD OFF UNTIL LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT AS THE FRONT MOVES THROUGH. THIS BOUNDARY WILL STALL IN THE TENNESSEE VALLEY AS HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES ON WEDNESDAY. A CLOSED LOW WILL PASS SOUTH OF THE REGION ON THURSDAY AND THURSDAY NIGHT WHICH MAY SPREAD SHOWERS AND THUNDERSTORMS BACK INTO THE SOUTHERN ZONES. AFTER THIS PASSES HIGH PRESSURE WILL BE ABLE TO BUILD SOUTH OVER THE REGION FOR THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES AT THE BEGINNING OF THE PERIOD WILL TREND TOWARDS NORMAL BY LATER IN THE WEEK. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... WITH HIGH PRESSURE MOVING EAST...CONVECTION WILL ENTER THE REGION FROM THE WEST AS A WARM FRONTAL ZONE SETS UP THIS MORNING. THUNDERSTORMS OCCURRING OVER INDIANA WILL MOVE TO ILN TAF SITES STARTING AT 12Z. CONVECTION WITH MVFR MAY DIMINISH LATE THIS MORNING BEFORE REDEVELOPING IN THE AFTERNOON TO EARLY EVENING. WINDS WILL GUST OVER 20 KNOTS OUT OF THE SOUTHWEST DURING THE AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS ALONG THE FRONT. WINDS WILL SHIFT TO NORTHWEST IN THE EVENING AS THE WARM FRONT TRANSITIONS TO A BACK DOOR COLD FRONT...BRINGING DRIER AIR AND AN END TO THE CONVECTION. OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY INTO TUESDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...AR NEAR TERM...LATTO SHORT TERM...AR LONG TERM... AVIATION...CONIGLIO
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
936 PM CDT MON APR 2 2012 .UPDATE... HAVE EXTENDED THE WIND ADVISORY ACROSS CIMARRON COUNTY THROUGH MIDNIGHT...AND ALLOWED IT TO EXPIRE FOR DALLAM AND HARTLEY COUNTIES. LATEST OBSERVATIONAL AND SHORT-RANGE MODEL DATA SHOW A TIGHT LOW- LEVEL PRESSURE GRADIENT/REINFORCING SURGE OF NORTH/NORTHEAST WINDS TO IMPACT THE WESTERN OK PANHANDLE OVER THE NEXT FEW HOURS. RECENT OBS FROM KENTON...BOISE CITY...AND SPRINGFIELD CONTINUE TO SHOW ADVISORY LEVEL WINDS...AND KENTON JUST BRIEFLY HIT HIGH WIND WARNING CRITERIA. LET THE RED FLAG WARNING ACROSS THE SOUTHWEST/SOUTH CENTRAL TX PANHANDLE EXPIRE AS SCHEDULED AT 9 PM. WINDS HAVE DIMINISHED TO LESS THAN 20 MPH AND RELATIVE HUMIDITIES WILL CONTINUE TO INCREASE OVERNIGHT. ALSO ADJUSTED PRECIP CHANCES FOR THE REST OF TONIGHT BASED ON LATEST RADAR TRENDS. LINE OF CONVECTION RAPIDLY DEVELOPED AS PACIFIC COLD FRONT OVERTOOK DRYLINE. THIS LINE OF SEVERE CONVECTION WILL CONTINUE TO PIVOT NORTHEAST AHEAD OF POTENT MID-LEVEL VORT MAX ROUNDING CLOSED LOW OVER NM. MAIN FOCUS FOR PRECIPITATION EXPECTED TO SET UP OVER THE NORTHERN CWA AFTER MIDNIGHT AS VORT LOBE CONTINUES TO PIVOT NORTH AND EVENTUALLY NORTHWEST. SEVERE THREAT WILL LINGER THE LONGEST ACROSS THE NORTHEAST TX PANHANDLE AND EASTERN HALF OF THE OK PANHANDLE...BUT WILL EVENTUALLY DIMINISH THERE AS WELL LATER TONIGHT AS PACIFIC FRONT CONTINUES TO PUSH EAST AND STATIONARY FRONT ACROSS NORTHERN CWA EVENTUALLY PUSHES SOUTHEAST...SQUEEZING THE DEEPER LOW-LEVEL MOISTURE AND ASSOCIATED INSTABILITY EASTWARD. KB && .PREV DISCUSSION... /ISSUED 634 PM CDT MON APR 2 2012/ UPDATE... EXPANDED SEVERE THUNDERSTORM WATCH ONE TIER OF COUNTIES WESTWARD. SURFACE FRONT DRAPED SOUTH/SOUTHWEST ACROSS THE EASTERN OK AND NORTHEAST TEXAS PANHANDLE...AND DRYLINE EXTENDING SOUTH FROM THE FRONT ACROSS THE EASTERN TX PANHANDLE...WERE RETREATING TO THE WEST AND NORTHWEST IN RESPONSE TO SURFACE LOW DEVELOPING NORTHEAST INTO THE TX PANHANDLE AHEAD OF STRONG MID-LEVEL VORT MAX PIVOTING AROUND CLOSED MID/UPPER-LEVEL LOW OVER NM. LATEST RUC GUIDANCE SHOWS THIS BOUNDARY WILL CONTINUE TO RETREAT A LITTLE FARTHER EARLY THIS EVENING...BEFORE DRYLINE ACROSS SOUTHEAST TX PANHANDLE GETS OVERTAKEN BY PACIFIC FRONT AND SHOVED EASTWARD. KB PREV DISCUSSION... /ISSUED 625 PM CDT MON APR 2 2012/ UPDATE... CONVECTION WILL CONTINUE TO DEVELOP IN RESPONSE TO A COLD FRONT ACROSS THE PANHANDLES AND APPROACHING UPPER LOW FROM NEW MEXICO. THIS CONVECTION WILL AFFECT ALL OF THE TAF SITES THROUGH 10Z TUESDAY. VFR CONDITIONS WILL PREVAIL EXCEPT MVFR TO POSSIBLY IFR CONDITIONS IN AND NEAR THE CONVECTION. WINDS WILL BECOME NORTHERLY TO NORTHEASTERLY 15 AND 20 TO 25 AND 30 KNOTS WITH HIGHER GUSTS BEHIND THE COLD FRONT...WITH SOUTHERLY TO SOUTHWESTERLY WINDS AHEAD OF THE FRONT MAINLY THIS EVENING AT THE AMARILLO TAF SITE. SCHNEIDER PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... UPPER LEVEL LOW HAS CUTOFF FROM THE FLOW OVER CENTRAL NEW MEXICO. THIS LOW IS EXPECTED TO SLOWLY LIFT NORTHEAST THROUGH NORTHEAST NEW MEXICO AND ACROSS THE NORTHWEST PART OF OUR CWA INTO SOUTHWEST KANSAS BY WEDNESDAY AFTERNOON. A SURFACE COLD FRONT HAS STALLED NEAR THE CANADIAN RIVER VALLEY THIS AFTERNOON. THIS FRONT MAY LIFT BACK TO THE NORTH BRIEFLY THIS EVENING BEFORE MOVE SOUTHEAST AGAIN LATER TONIGHT. THE COLD FRONT WILL THEN STALL AGAIN BY TUESDAY AFTERNOON ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE BEFORE MOVING SOUTH OF THE TEXAS PANHANDLE BY TUESDAY EVENING. WILL KEEP THE NORTHWEST CWA UNDER A WIND ADVISORY THROUGH THE MID EVENING AS WINDS ARE EXPECTED TO PICK UP AGAIN BY EARLY THIS EVENING AS ANOTHER SURGE OF COLDER AIR MOVES SOUTH. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE EASTERN CWA ALONG A DRYLINE AND THEN THE BEST CHANCE OF SHOWERS AND STORMS WILL BE ALONG AND BEHIND THE COLD FRONT ACROSS THE NORTHERN CWA. THIS UPPER LEVEL LOW WILL HAVE SEVERAL SPOKES OF VORTICITY ROTATING AROUND IT AS WELL...SO THE SHOWER AND THUNDERSTORM POTENTIAL WILL PICK UP EACH TIME ONE THESE MOVES OVER THE REGION. ON TUESDAY...WILL KEEP THE SHOWERS AND THUNDERSTORMS GOING AS THE COLD CORE OF THE LOW MOVES OVER THE PANHANDLES. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY ON TUESDAY. PRECIPITATION CHANCES DECREASE FROM SOUTHWEST TO NORTHEAST TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE UPPER LOW MOVES AWAY. UPPER LEVEL SHORT WAVE RIDGING TAKES OVER THE HIGH PLAINS WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AHEAD OF ANOTHER LARGE UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST. A DRYLINE IS EXPECTED TO MOVE TO THE EASTERN CWA BY FRIDAY AFTERNOON. THIS DRYLINE WILL HOLD IN THE EASTERN CWA FRIDAY NIGHT AS THE WIND SHEAR ALOFT INCREASES AS THE UPPER TROUGH MOVES ACROSS THE NORTHERN HIGH PLAINS. THE INCREASED WIND SHEAR AND INSTABILITY MAY LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN CWA FRIDAY NIGHT...SO HAVE ADDED SOME SLIGHT CHANCE POPS FOR NOW. A COLD FRONT MOVES SOUTH ACROSS THE CWA ON SATURDAY NIGHT...COOLING SUNDAY/S HIGHS BACK 10 TO 15 DEGREES. FIRE WEATHER... WILL CONTINUE TO HOLD ONTO THE RED FLAG WARNING FOR THE SOUTHWEST AND SOUTH CENTRAL TEXAS PANHANDLE THROUGH EARLY THIS EVENING. SOUTHWEST WINDS SHOULD INCREASE THROUGH THE REST OF THE AFTERNOON INTO EARLY THIS EVENING AS A SURFACE LOW INTENSIFIES OVER THE CENTRAL TEXAS PANHANDLE. THE WINDS WILL THEN PICK UP BEHIND A COLD FRONT TONIGHT...ESPECIALLY ACROSS THE NORTHWEST CWA...BUT RELATIVE HUMIDITIES WILL BE ABOVE 20 PERCENT. THE CHANCES OF RAIN INCREASE TONIGHT THROUGH TUESDAY. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: CIMARRON. && $$ 11/08
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
634 PM CDT MON APR 2 2012 .UPDATE... EXPANDED SEVERE THUNDERSTORM WATCH ONE TIER OF COUNTIES WESTWARD. SURFACE FRONT DRAPED SOUTH/SOUTHWEST ACROSS THE EASTERN OK AND NORTHEAST TEXAS PANHANDLE...AND DRYLINE EXTENDING SOUTH FROM THE FRONT ACROSS THE EASTERN TX PANHANDLE...WERE RETREATING TO THE WEST AND NORTHWEST IN RESPONSE TO SURFACE LOW DEVELOPING NORTHEAST INTO THE TX PANHANDLE AHEAD OF STRONG MID-LEVEL VORT MAX PIVOTING AROUND CLOSED MID/UPPER-LEVEL LOW OVER NM. LATEST RUC GUIDANCE SHOWS THIS BOUNDARY WILL CONTINUE TO RETREAT A LITTLE FARTHER EARLY THIS EVENING...BEFORE DRYLINE ACROSS SOUTHEAST TX PANHANDLE GETS OVERTAKEN BY PACIFIC FRONT AND SHOVED EASTWARD. KB && .PREV DISCUSSION... /ISSUED 625 PM CDT MON APR 2 2012/ UPDATE... CONVECTION WILL CONTINUE TO DEVELOP IN RESPONSE TO A COLD FRONT ACROSS THE PANHANDLES AND APPROACHING UPPER LOW FROM NEW MEXICO. THIS CONVECTION WILL AFFECT ALL OF THE TAF SITES THROUGH 10Z TUESDAY. VFR CONDITIONS WILL PREVAIL EXCEPT MVFR TO POSSIBLY IFR CONDITIONS IN AND NEAR THE CONVECTION. WINDS WILL BECOME NORTHERLY TO NORTHEASTERLY 15 AND 20 TO 25 AND 30 KNOTS WITH HIGHER GUSTS BEHIND THE COLD FRONT...WITH SOUTHERLY TO SOUTHWESTERLY WINDS AHEAD OF THE FRONT MAINLY THIS EVENING AT THE AMARILLO TAF SITE. SCHNEIDER PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... UPPER LEVEL LOW HAS CUTOFF FROM THE FLOW OVER CENTRAL NEW MEXICO. THIS LOW IS EXPECTED TO SLOWLY LIFT NORTHEAST THROUGH NORTHEAST NEW MEXICO AND ACROSS THE NORTHWEST PART OF OUR CWA INTO SOUTHWEST KANSAS BY WEDNESDAY AFTERNOON. A SURFACE COLD FRONT HAS STALLED NEAR THE CANADIAN RIVER VALLEY THIS AFTERNOON. THIS FRONT MAY LIFT BACK TO THE NORTH BRIEFLY THIS EVENING BEFORE MOVE SOUTHEAST AGAIN LATER TONIGHT. THE COLD FRONT WILL THEN STALL AGAIN BY TUESDAY AFTERNOON ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE BEFORE MOVING SOUTH OF THE TEXAS PANHANDLE BY TUESDAY EVENING. WILL KEEP THE NORTHWEST CWA UNDER A WIND ADVISORY THROUGH THE MID EVENING AS WINDS ARE EXPECTED TO PICK UP AGAIN BY EARLY THIS EVENING AS ANOTHER SURGE OF COLDER AIR MOVES SOUTH. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE EASTERN CWA ALONG A DRYLINE AND THEN THE BEST CHANCE OF SHOWERS AND STORMS WILL BE ALONG AND BEHIND THE COLD FRONT ACROSS THE NORTHERN CWA. THIS UPPER LEVEL LOW WILL HAVE SEVERAL SPOKES OF VORTICITY ROTATING AROUND IT AS WELL...SO THE SHOWER AND THUNDERSTORM POTENTIAL WILL PICK UP EACH TIME ONE THESE MOVES OVER THE REGION. ON TUESDAY...WILL KEEP THE SHOWERS AND THUNDERSTORMS GOING AS THE COLD CORE OF THE LOW MOVES OVER THE PANHANDLES. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY ON TUESDAY. PRECIPITATION CHANCES DECREASE FROM SOUTHWEST TO NORTHEAST TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE UPPER LOW MOVES AWAY. UPPER LEVEL SHORT WAVE RIDGING TAKES OVER THE HIGH PLAINS WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AHEAD OF ANOTHER LARGE UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST. A DRYLINE IS EXPECTED TO MOVE TO THE EASTERN CWA BY FRIDAY AFTERNOON. THIS DRYLINE WILL HOLD IN THE EASTERN CWA FRIDAY NIGHT AS THE WIND SHEAR ALOFT INCREASES AS THE UPPER TROUGH MOVES ACROSS THE NORTHERN HIGH PLAINS. THE INCREASED WIND SHEAR AND INSTABILITY MAY LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN CWA FRIDAY NIGHT...SO HAVE ADDED SOME SLIGHT CHANCE POPS FOR NOW. A COLD FRONT MOVES SOUTH ACROSS THE CWA ON SATURDAY NIGHT...COOLING SUNDAY/S HIGHS BACK 10 TO 15 DEGREES. FIRE WEATHER... WILL CONTINUE TO HOLD ONTO THE RED FLAG WARNING FOR THE SOUTHWEST AND SOUTH CENTRAL TEXAS PANHANDLE THROUGH EARLY THIS EVENING. SOUTHWEST WINDS SHOULD INCREASE THROUGH THE REST OF THE AFTERNOON INTO EARLY THIS EVENING AS A SURFACE LOW INTENSIFIES OVER THE CENTRAL TEXAS PANHANDLE. THE WINDS WILL THEN PICK UP BEHIND A COLD FRONT TONIGHT...ESPECIALLY ACROSS THE NORTHWEST CWA...BUT RELATIVE HUMIDITIES WILL BE ABOVE 20 PERCENT. THE CHANCES OF RAIN INCREASE TONIGHT THROUGH TUESDAY. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...DEAF SMITH...OLDHAM...POTTER... RANDALL. WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: DALLAM...HARTLEY. OK...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: CIMARRON. && $$ 11/08
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
617 PM CDT MON APR 2 2012 .AVIATION... THUNDERSTORMS ASSOCIATED WITH A NORTHWARD MOVING SHORTWAVE OVER NORTHEAST TEXAS SHOULD REMAIN EAST OF THE TAF SITES WHILE GRADUALLY WEAKENING THIS EVENING. WILL HAVE TO WATCH FOR A FEW ISOLATED STORMS ASSOCIATED WITH CONVERGENCE ALONG A WEAK WESTWARD MOVING OUTFLOW BOUNDARY WHILE THE SURFACE REMAINS RELATIVELY WARM THROUGH EARLY THIS EVENING. AT THIS TIME FEEL WEAK SUBSIDENCE IN WAKE OF THE MID LEVEL WAVE WILL INHIBIT SIGNIFICANT DEVELOPMENT. WILL LEAVE PREDOMINANT TS OUT OF THE FORECAST FOR THE TIME BEING...BUT MAY INCLUDE A VCSH FOR THE NEXT COUPLE OF HOURS AS THE BOUNDARY SLOWS AND STALLS OVER THE METROPLEX. THE MAIN IMPACT WILL LIKELY BE AN EAST COMPONENT TO THE SURFACE WINDS AT DALLAS COUNTY AIRPORTS FOR AT LEAST THE NEXT FEW HOURS. MEANWHILE...THUNDERSTORMS WILL CONTINUE TO DEVELOP JUST WEST OF THE CWA ALONG A DRYLINE...AS SUPPORT FROM AN UPPER LOW OVER NEW MEXICO ARRIVES FROM THE WEST. RIGHT NOW IT LOOKS LIKE THIS CONVECTION WILL REMAIN MOSTLY NORTHWEST OF TAF SITES TONIGHT AS INITIAL SHORTWAVE ROTATES NORTHEASTWARD FROM WEST TEXAS INTO OKLAHOMA. HOWEVER...IF ACTIVITY TO OUR WEST REMAINS FURTHER SOUTH AS IT SPREADS EAST...WILL UPDATE TO INCLUDE THUNDER FOR AN HOUR OR 2 AROUND THE 03Z TIME FRAME. THE UPPER LOW WILL ADVANCE EAST TOMORROW AS ANOTHER STRONGER SHORTWAVE SWINGS EAST AROUND THE BASE OF THE UPPER LOW...AND ENHANCES ACTIVITY ALONG THE DRYLINE AGAIN TOMORROW MORNING. TIMING FOR THE ONSET OF CONVECTIVE WEATHER AT AREAS TERMINALS IS TRICKY DUE TO VARIATIONS IN MODEL HANDLING OF BOTH SYNOPTIC AND MESOSCALE FEATURES. RIGHT NOW A COMBINATION OF NAM12...AND BOTH THE TT AND OUN WRF WILL BE USED...WITH THE IDEA THAT THE I 35 CORRIDOR WILL SEE THE BEST CHANCE FOR THUNDERSTORMS AROUND MID DAY TUESDAY. OTHERWISE MVFR CIGS WILL LIKELY AFFECT ALL AREAS BY EARLY TOMORROW MORNING. CIGS SHOULD IMPROVE SOME AHEAD OF THE ANTICIPATED LINE OF STORMS LATE TOMORROW MORNING/EARLY AFTERNOON. WINDS WILL REMAIN OUT OF THE SOUTHEAST UNTIL THE DRYLINE AND PACIFIC FRONT PUSH THROUGH THE AREA TOMORROW NIGHT. 30 && .PREV DISCUSSION... /ISSUED 307 PM CDT MON APR 2 2012/ MAIN UPPER LOW FEATURE SITS ACROSS CENTRAL NEW MEXICO. WEAK LOBE THAT WAS NEAR TX COAST YESTERDAY HAS ROTATED NORTH AND SITS OVER THE DFW METROPLEX. CIRCULATION AROUND THE WEAK LOW AND ASSOCIATED SHORT WAVE HAS FIRED OFF SEVERE STORMS IN EASTERN NORTH TEXAS...BUT AS THIS SYSTEM MOVES ON NORTH WE FEEL THAT THE DRY LINE WILL BECOME THE MAIN PLAYER FOR TONIGHT AND TOMORROW. GUIDANCE AGREES ON A GENERAL SOLUTION OF THE UPPER LOW PUSHING EAST AND THEN NORTHEAST TO LIE OVER THE TX/OK PANHANDLES ON TUESDAY. THE UPPER LOW MOVEMENT PUSHES THE DRY LINE ACROSS NORTH TEXAS ON TUESDAY AS WELL. THE DISAGREEMENT IS ABOUT HOW CONVECTION WILL EVOLVE WITH THE SYSTEM. THE LATEST RUC ACTIVATES THE DRY LINE EARLY THIS EVENING. THE NAM INITIATES DRY LINE CONVECTION WELL AFTER MIDNIGHT AS DOES THE LATEST HRRR. WITH SOME CU ALREADY DEVELOPING WEST OF THE CWA...WILL STICK WITH OUR PREVIOUS SOLUTION WHICH AGREES WITH THE RUC AND THE GFS FOR DRY LINE CONVECTION THIS AFTERNOON/EVENING MOVING INTO NORTHWEST COUNTIES. EITHER CONVECTION WILL MAINTAIN IN SOME FORM OVERNIGHT AND REINVIGORATE TOMORROW WITH DAYTIME HEATING...OR IT MAY DIE OUT AND REGENERATE TOMORROW. EITHER WAY...WE HAVE HIGHER CONFIDENCE OF A LINEAR FEATURE DEVELOPING DURING THE DAY TOMORROW AS THE DRY LINE PUSHES EAST. WITH STEEP LAPSE RATES LARGE HAIL AND DAMAGING WINDS ARE LIKELY TO OCCUR. STORMS SHOULD SWEEP EAST OF THE AREA BY LATE EVENING OR EARLY WEDNESDAY MORNING...AND POPS END SUNRISE WEDNESDAY. THE NAM IS AN OUTLIER...HOLDING THE DRY LINE BACK ABOUT 8 HOURS BEHIND THE GFS...AND IF THIS OCCURS WE WOULD HAVE TO ADD POPS FOR WEDNESDAY MORNING. SHORT WAVE RIDGING MOVES IN WEDNESDAY AFTERNOON...AND NORTH TX SHOULD REMAIN DRY THROUGH SUNDAY MORNING...WHEN A NEW FRONT IS EXPECTED TO DROP INTO THE AREA AND INCREASE THE POPS A BIT. 84 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 66 81 54 80 55 / 40 60 40 5 0 WACO, TX 67 79 54 83 55 / 20 60 30 5 0 PARIS, TX 65 79 59 81 54 / 20 50 60 10 0 DENTON, TX 65 79 54 78 54 / 40 60 30 5 0 MCKINNEY, TX 66 81 54 80 55 / 30 60 40 5 0 DALLAS, TX 66 82 55 81 55 / 30 60 40 5 0 TERRELL, TX 66 80 60 80 55 / 20 60 50 10 0 CORSICANA, TX 67 81 61 81 55 / 20 60 50 10 0 TEMPLE, TX 67 78 58 84 55 / 20 60 30 5 0 MINERAL WELLS, TX 64 77 53 81 52 / 50 40 10 5 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 30/58
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1149 PM CDT SAT MAR 31 2012 .DISCUSSION... LOOKS LIKE VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. SEE THE BELOW AVIATION SECTION. && .AVIATION... LATEST MODELS DID NOT INDICATE ANY NEED FOR CHANGES TO THE CURRENT TERMINALS. GUSTY SOUTHWEST SURFACE WINDS TOMORROW AFTERNOON STILL LOOK LIKELY. HUBER && .PREV DISCUSSION... /ISSUED 635 PM CDT SAT MAR 31 2012/ DISCUSSION... EXPECT VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR THE NEXT 24 HOURS. AVIATION BELOW HAS ADDITIONAL INFORMATION. AVIATION... MODELS CONTINUE TO HOLD A SURFACE TROUGH OF LOW PRESSURE...AND AN ASSOCIATED SURFACE DRYLINE...IN THE TEXAS AND NEW MEXICO AREA FOR THE NEXT 24 HOURS. THE LATEST RUC INDICATES THE SURFACE PRESSURE GRADIENT WILL INCREASE ACROSS WEST CENTRAL TEXAS OVERNIGHT TONIGHT. THUS...LOOK FOR GUSTY SOUTHWEST SURFACE WINDS TO DOMINATE WEST CENTRAL TEXAS BY 06Z TONIGHT. FOR TOMORROW AFTERNOON...WATCH FOR STRONGER SOUTHWEST SURFACE WINDS AS THE SURFACE PRESSURE GRADIENT STRENGTHENS ACROSS WEST CENTRAL TEXAS. HUBER PREV DISCUSSION... /ISSUED 334 PM CDT SAT MAR 31 2012/ SHORT TERM... AN UPPER LEVEL RIDGE WILL AMPLIFY THROUGH TOMORROW AS IT BUILDS EAST OF THE FORECAST AREA AHEAD OF AN APPROACHING UPPER LEVEL TROUGH... WHICH WILL BE OVER THE SOUTHERN ROCKIES BY LATE TOMORROW. HOT AND DRY WEATHER WILL CONTINUE ACROSS WEST CENTRAL TEXAS TOMORROW WITH LOW TO UPPER 90S OVER THE CWA...THE WARMEST TEMPERATURES SHOULD BE OVER THE NORTHERN HALF OF THE CWA AS THE 850MB THERMAL RIDGE LIFTS FURTHER TO THE NORTH. 15 LONG TERM... THE DEEP CLOSED LOW OFF THE PACNW COAST WILL BE A PLAYER IN OUR WEATHER AS THE LONG TERM OPENS BUT THE MEDIUM RANGE MODELS CONTINUE TO STRUGGLE WITH THE TIMING. THE LATEST RUNS SUGGEST THAT THIS FEATURE WILL SLOW AS IT MOVES ACROSS THE SOUTHWEST CONUS...LIFTING NORTHEAST ACROSS THE TX PANHANDLE AFTER 00Z WEDNESDAY. THIS LATER ARRIVAL WILL LIKELY RESULT IN THE DRYLINE SETTING UP FARTHER WEST THAN PREVIOUS ANTICIPATED GIVEN WEAKER FORCING. STRONG SYNOPTIC LIFT /DEPICTED BY H5-H3 Q VECTOR CONVERGENCE/ IS PROGGED TO REMAIN WEST OF THE CWA UNTIL MONDAY NIGHT BY WHICH TIME THE DRYLINE WILL BE RETREATING. THUNDERSTORMS WILL BE POSSIBLE ALONG AND EAST OF THE DRYLINE LATE MONDAY AFTERNOON. SURFACE TEMPS IN THE MID/UPPER 80S AND DEWPOINTS WILL RESULT IN SIGNIFICANT INSTABILITY /SBCAPES OF 1500-3000/ BUT A SLOWER ARRIVAL OF SYNOPTIC ASCENT MAY RESULT IN THE CAP HOLDING STRONG AND LIMITING THE CONVECTIVE POTENTIAL /ESPECIALLY IN THE EAST IN THE AREA OF STRONGEST INSTABILITY/...MUCH OF THE CHAGRIN OF THE SOUTHERN PLAINS CHASE COMMUNITY. I OPTED TO MAINTAIN THE INHERITED POPS ON THE CENTRAL AND EAST ON MONDAY AFTERNOON BUT EXPANDED THEM WEST MONDAY NIGHT AND TUESDAY TO ACCOUNT FOR THE SLOWER TIMING. COOLER TEMPS ARE EXPECTED ON TUESDAY AS A PACIFIC COLD FRONT MOVES THROUGH THE AREA. I LOWERED MAX TEMPS INTO THE MID/UPPER 70S BUT FEEL I MAY STILL BE A FEW DEGREES ON THE WARM SIDE BASED ON H85 TEMPS. I AM NOT SOLD ON THE AGGRESSIVE RETURN OF SOUTHERLY FLOW SHOWN BY THE GFS AND LEANED MORE HEAVILY ON THE ECMWF SOLUTION IN THE POST FRONTAL ENVIRONMENT. WITH THAT SAID...I KEPT MAX TEMPS GENERALLY AT OR JUST BELOW 80 DEGREES ON WEDNESDAY BUT DRY CONDITIONS WILL RESULT IN A VERY PLEASANT DAY. MIN TEMPS TUESDAY NIGHT ARE EXPECTED TO BE IN THE MID/UPPER 50S...WARMING SLIGHTLY /LOWER 50S/ BY WEDNESDAY NIGHT. BY THURSDAY...THE H85 THERMAL RIDGE WILL BUILD BACK OVER THE AREA WITH INCREASING SOUTHERLY WINDS. TEMPS ARE EXPECTED TO WARM BACK INTO THE MID 80S. THESE SOUTHERLY WINDS WILL BRING THE LOW LEVEL MOISTURE BACK THURSDAY NIGHT AND FRIDAY. THE MODELS ARE HINTING AT SOME CONVECTION DEVELOPING OVER WEST TX FRIDAY EVENING ALONG THE DRYLINE BUT MY GUT SAYS THAT MOISTURE RETURN WILL NOT BE ADEQUATE TO SUPPORT MORE THAN FEW HIGH BASED STORMS. THUS...NO POPS WERE INCLUDED AT THIS TIME. HOWEVER...CONSIDERABLE UNCERTAINTY EXISTS AT THIS TIME. TEMPS WILL AGAIN BE WARM ON FRIDAY WITH HIGHS IN THE MID/UPPER 80S. THE GFS/DGEX DEPICT A WEAK COLD FRONT STALLING OVER THE AREA BY NEXT WEEKEND...ENHANCING RAIN CHANCES. HOWEVER...THE ECMWF KEEPS THIS BOUNDARY NORTH OF THE CWA IN CONJUNCTION WITH THE UPPER LEVEL SYSTEM. THE ECMWF ALSO PUSHES H5 HEIGHTS UP NEAR 585DM WITH THE MID LEVEL ANTICYCLONE CENTERED OVER DEEP SOUTH TX WHEREAS THE GFS KEEPS HEIGHTS AROUND 580DM WITH THE RIDGE CENTERED OVER THE GULF OF MEXICO. I WILL LET THE MODELS CONTINUE TO TEASE US OVER THE NEXT FEW DAYS BEFORE JUMPING ON ANY PARTICULAR SOLUTION. JOHNSON FIRE WEATHER... ELEVATED FIRE WEATHER CONDITIONS CAN BE EXPECTED SUNDAY OVER THE BIG COUNTRY...CONCHO VALLEY AND THE NORTHERN EDWARDS PLATEAU WITH UNSEASONABLY HOT TEMPERATURES IN THE 90S CONTINUING...ACCOMPANIED BY LOW RELATIVE HUMIDITY VALUES...AND SOUTHWEST WINDS BETWEEN 15 AND 20 MPH. CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE MAINLY WEST OF A LINE FROM HASKELL TO STERLING CITY SUNDAY AFTERNOON WITH 20 FOOT SOUTHWEST WINDS APPROACHING 20 MPH AND RELATIVE HUMIDITY VALUES DROPPING TO LESS THAN 10 PERCENT. 15 && .PRELIMINARY POINT TEMPS/POPS... ABILENE 65 96 65 85 52 / 0 0 0 20 30 SAN ANGELO 60 96 62 86 51 / 0 0 0 20 20 JUNCTION 62 93 64 87 51 / 10 10 10 20 30 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HUBER
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
205 AM EDT SUN APR 1 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA TONIGHT. THIS HIGH WILL MOVE SOUTHEAST OF OUR AREA ON SUNDAY. ANOTHER APPROACHING COLD FRONT WILL ENTER OUR AREA BY MONDAY MORNING. && .NEAR TERM /THROUGH TODAY/... AS OF 945 PM EDT SATURDAY... PERSISTENT CLUSTER OF SCATTERED THUNDERSTORMS FROM GRAYSON COUNTY INTO WILKES COUNTY WAS GRADUALLY DRIFTING EAST. AREAS RADAR CONTINUES TO SHOW ISOLATED SHOWERS AND THUNDERSTORMS ON THE EASTERN AND SOUTHEAST FRINGE OF THE COUNTY WARNING AREA. LOCAL WRF AND HRRR GUIDANCE HAD PRECIPITATION ENDING ACROSS THE FORECAST AREA BY MIDNIGHT. ADJUSTED PROBABILITY OF PRECIPITATION IN THE FORECAST FOR THIS TIMING. ALSO ADDED PATCHY FOG IN FOG THE GREENBRIER RIVER VALLEY AND IN THE AREAS ACROSS THE SOUTHWEST COUNTY WARNING AREA THAT HAD RAIN SATURDAY AFTERNOON AND EVENING. DEW POINTS HAVE ALREADY DROPPED INTO THE UPPER 30S TO LOWER 40S IN THE FAR NORTHERN COUNTY WARNING AREA. SURFACE DEW POINTS WILL CONTINUE TO LOWER BEHIND THE FRONT ACROSS THE SOUTHERN COUNTIES OF THE FORECAST AREA. HAD MADE SLIGHT ADJUSTMENTS TO OVERNIGHT LOWS BASED ON 9PM OBS...CLOUD COVER AND THE LATEST LAMP GUIDANCE. NAM AND LOCAL WRF HAD LAYER OF LOW CLOUDS SPREADING ACROSS CENTRAL AND EASTERN VIRGINIA OVERNIGHT...AND REACHING AS FAR WEST AS LYNCHBURG AND DANVILLE. HAVE ADDED MORE CLOUD COVER IN THE EAST SINCE CEILINGS ARE ALREADY LOWERING JUST NORTH AND EAST OF THE FORECAST AREA. THE CLOUDS IN THE EAST MAY TAKE MOST OF THE MORNING TO MIX OUT. BUFKIT SOUNDINGS WERE SUGGESTING THAT CLOUDS MAY NOT BECOME SCATTERED UNTIL AFTER 11AM. AS OF 330 PM EDT SATURDAY... SURFACE ANALYSIS INDICATES THAT THE COLD FRONT IS LOCATED ACROSS OUR SOUTHERNMOST TIER OF COUNTIES THIS AFTERNOON...AND IS CONTINUING TO MOVE SOUTHEAST. RADAR HAS INDICATED THAT SPOTTY SHOWER ACTIVITY...AND A FEW THUNDERSTORMS...HAS DEVELOPED ACROSS OUR AREA WITH AFTERNOON HEATING...BUT NONE OF THIS ACTIVITY IS VERY STRONG. THAT STATED...CANNOT RULE OUT ONE OR TWO STRONG BUT SHORT LIVED THUNDERSTORMS DEVELOPING DURING EARLY EVENING. WEAK HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA THIS EVENING...WHICH WILL RESULT IN NORTHWESTERLY FLOW THROUGH THE FIRST FEW HOURS OF SUNDAY MORNING. THIS DOWNSLOPE FLOW WILL ALLOW CLOUD COVER TO DIMINISH ACROSS MUCH OF OUR AREA...ESPECIALLY AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WEATHER FORECAST MODELS HAVE INDICATED THE POSSIBILITY OF LOW CLOUDS REDEVELOPING TONIGHT ALONG THE EAST FACING SLOPES IN SOUTHEAST WEST VIRGINIA AND THE MOUNTAIN EMPIRE...AS RESIDUAL LOW LEVEL MOISTURE BECOMES WEDGED ALONG THE RIDGELINES. WITH LIGHT WINDS ACROSS THE AREA...WILL ALSO BE LOOKING AT THE POSSIBILITY OF PATCHY FOG DEVELOPING ACROSS PORTIONS OF THE MOUNTAINS...ESPECIALLY IN THE RIVER VALLEYS. THE HIGH WILL SLIDE SOUTHEAST BY SUNRISE SUNDAY MORNING...AND WE WILL BEGIN TO SEE SOUTHERLY WINDS TAKE OVER. WITH PLENTY OF DRY AIR ALOFT...EXPECT THAT ANY FOG AND LOW CEILINGS WILL BURN OFF BY 10 AM...AND EXPECT MOSTLY CLEAR SKIES THROUGH EARLY AFTERNOON AREAWIDE. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... AS OF 330 PM EDT SATURDAY... ON SUNDAY NIGHT...THE NORTHEAST U.S. UPPER TROF DEEPENS IN RESPONSE TO A SHORTWAVE MOVING SOUTHEAST. THIS WILL DRIVE A COLD FRONT THROUGH THE FORECAST AREA AND SPARK A COMPLEX OF STORMS AS LOW LEVEL THETA-E RIDGE INCREASES IN ADVANCE OF THE FRONT. BEST LOW LEVEL CONVERGENCE WILL BE FOUND SE WV AND WEST OF I-77 WHERE HIGHEST POPS WERE PLACED. INCREASED LOW TEMPERATURES A COUPLE OF DEGREES WITH A FAIR AMOUNT OF CLOUDS AND MIXING. AS WEAK HIGH PRESSURE TRIES TO WEDGE DOWN THE EASTERN U.S. A WEAK LOW LEVEL CONVERGENCE ZONE IS ESTABLISHED IN THE FAR SOUTHWEST PORTION OF THE FORECAST AREA. WITH THE GREATEST INSTABILITY EXPECTED TO BE LOCATED HERE...WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE. LEANED TOWARD THE COOLER NAM MOS GUIDANCE FOR HIGHS IN THE EAST WITH A LOW LEVEL NORTHEAST FLOW IN PLACE. FOR MONDAY NIGHT AND TUESDAY...AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE REGION...BUT IS QUICKLY FLATTENED BY A NORTHERN STREAM SYSTEM MOVES ACROSS SOUTHERN CANADA AND THE NORTHERN GREAT LAKES. THE LOW LEVEL FLOW IN ADVANCE OF THIS SYSTEM COMES AROUND TO THE SOUTH/SOUTHWEST USHERING IN HIGHER DEWPOINTS AND POTENTIALLY A DECK OF LOW LEVEL STRATUS CLOUDS WITH GOOD MOISTURE ADVECTION. ISENTROPIC LIFT ON THE LEADING EDGE OF THIS MAY BRING ANOTHER ROUND OF RAIN THE FAR SOUTHWEST MONDAY NIGHT...WITH SHOWERS AND THUNDERSTORMS DEVELOPING IN ADVANCE OF THE FRONT IN THE NORTHERN AND WESTERN PORTION OF THE FORECAST AREA ON TUESDAY UNDER THE INSTABILITY AXIS. TEMPERATURE FORECAST TUESDAY IS A TRICKY ONE AND HIGHS WILL DEPEND ON THE AMOUNT OF CLOUD COVER SEEN. WITH THE POTENTIAL FOR LOW CLOUDS TO ADVANCE INTO OUR AREA...DROPPED HIGHS A FEW DEGREES TOWARD THE COOLER LOCALLY DERIVED MOS FORECAST HIGHS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 330 PM EDT SATURDAY... FOR THE LONG TERM PORTION OF THE FORECAST...WE LEANED HEAVILY ON THE 00Z ECMWF SOLUTION WHICH SHOWS BETTER RUN TO RUN CONSISTENCY COMPARED TO THE GFS WITH ITS HANDLING OF THE TIMING AND EVOLUTION OF A CUT OFF LOW DRIFTING ACROSS THE SOUTHERN PLAINS...THEN THE SOUTHEAST U.S. LATE IN THE PERIOD. THE ECMWF IS ALSO IN BETTER AGREEMENT WITH THE CANADIAN AND UKMET SOLUTIONS. THE GFS ENSEMBLE MEMBERS SHOW A WIDE RANGE OF POTENTIAL SOLUTIONS TO THE STRENGTH AND LOCATION OF THIS UPPER LEVEL LOW WHICH GIVES US LOW CONFIDENCE IN THE OPERATIONAL GFS SOLUTION. SOME SIGNIFICANT MODIFICATIONS WERE MADE TO THE FORECAST BASED ON THE ECMWF FORECAST. FIRST...WITH THE SLOWER TIMING...NOW EXPECT THE COLD FRONT TO MOVE THROUGH LATE WEDNESDAY...ALLOWING TEMPERATURES TO BE WELL ABOVE NORMAL WITH A DEEP WEST...DOWNSLOPING FLOW...WITH THUNDERSTORMS POSSIBLE ALONG THE FRONT. BEHIND THIS FRONT...TRENDED TEMPERATURES DOWN BY SEVERAL DEGREES THUR-SATURDAY AS A LOW LEVEL NORTHEAST...THEN EAST...FLOW DEVELOPS WITH THE UPPER LOW TO OUR SOUTH AND CANADIAN HIGH PRESSURE BUILDING IN THE NE U.S. WITH THE NAO FORECAST TO BECOME NEGATIVE AND THE GLOBAL WIND OSCILLATION (GWO) IN A FAVORABLE PHASE FOR COOLER THAN NORMAL CONDITIONS IN THE EASTERN U.S...THE COOLER ECMWF TEMPERATURES APPEAR REASONABLE. DEPENDING ON THE LOCATION OF THE UPPER LOW...SHOWERS/RAIN WILL BE POSSIBLE EACH DAY...ESPECIALLY FOR THOSE FAVORED EASTERN UPSLOPE AREAS AND TO THE SOUTH...CLOSER TO THE LOCATION OF THE UPPER LOW. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 200 AM EDT SUNDAY... WEAK SURFACE HIGH PRESSURE BUILDING SOUTH OUT OF NEW ENGLAND RESULTING IN NORTHEASTERLY MOIST FLOW FROM OFF ATLANTIC ALONG WITH MVFR CEILINGS AT KLYH AND KDAN. UPSLOPING WESTERLY MOIST FLOW ALSO RESULTING IN MVFR RESTRICTIONS AT KBLF. THESE CONDITIONS ARE LIKELY TO PERSIST FOR THE REST OF THE NIGHT...BUT SHOULD GRADUALLY MIX BACK OUT TO VFR WITH UNRESTRICTED CONDITIONS BY MID TO LATE MORNING AS STRONG INSOLATION HELPS TO MIX UP/OUT INVERSION LAYER. ELSEWHERE AT KROA AND KBCB...MAINLY VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. HOWEVER...SOME PATCHY FOG WITH LOCALIZED IFR TO EVEN LIFR RESTRICTIONS IS POSSIBLE IN SOME OF THE MOUNTAIN VALLEYS UNTIL SHORTLY AFTER DAYBREAK SUNDAY...AND THIS THREAT CONTINUES TO BE REFLECTED IN CLIMATOLOGICALLY FAVORED LOCATIONS... SUCH AS AT/NEAR KLWB. APPROACH OF NEXT UPSTREAM WEATHER SYSTEM AND ASSOCIATED COOL FRONT MAY BRING A THREAT FOR SCATTERED SHOWERS/THUNDERSTORMS TONIGHT (SUNDAY NIGHT)...ALONG WITH POSSIBLE RESTRICTIONS BACK INTO MVFR RANGE...ESPECIALLY IN THE MOUNTAINS. THIS FRONT IS EXPECTED TO STALL OVER/ALONG THE MID APPALACHIANS ON/BY MONDAY. ADDITIONAL WEAK SHORT WAVES AND MOISTURE STREAMING NORTHEAST OVER THE STALLED FRONT...COMBINING WITH AN EASTERLY FLOW FROM OFF THE ATLANTIC...MAY SET THE STAGE FOR ADDITIONAL MVFR WEATHER...POTENTIALLY LOWER...INTO THE MID WEEK PERIOD...ESPECIALLY OVER THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/NF NEAR TERM...AMS/NF SHORT TERM...PH LONG TERM...PH AVIATION...WERT
AREA FORECAST DISCUSSION
NWS SPOKANE WA
225 PM PDT Sun Apr 1 2012 .SYNOPSIS... The widespread wet weather over the past several days will come to an end tonight leading to a dry start of the work week. A Pacific cold front will move through the area Tuesday night and Wednesday for more rain and mountain snow. The remainder of the week will see cool temperatures with afternoon and evening showers. Next weekend should be dry and warmer. && .DISCUSSION... Tonight: Afternoon instability convective showers will quickly die off this evening along with the winds. The HRRR model (which has done a great job with the convective line between Coulee Dam and Spokane) is suggesting the formation of a convective line that will move across the Spokane/Cd`A metro area around 7pm this evening. Not enough confidence to hit the forecast hard but the HRRR suggests it would be a graupel shower. Winds are gusting to 35 mph but should be diminishing quickly so will cancel the wind advisory with the afternoon forecast package. Another minor wave has moved onto the Oregon coast today. Models show the remnants of this wave tracking across northern Oregon and then into the southern Panhandle. Will keep pops in the Panhandle higher south of I-90. Any precip that does fall would all be in the form of snow as snow levels come crashing down to the valleys overnight. Light accumulations are possible in the valleys south/east of Pullman. RJ Monday through Tuesday night...High pressure will build over the region on Monday for a warming and drying trend. This will be followed by another deep low pressure system moving into the region Tuesday and Tuesday night. Monday and Monday night the ridge axis will be over the Inland Northwest Monday morning ans slide east through the day. The 12z models were showing a weak wave moving through my southeast zones overnight and early Monday morning, with the NAM being a bit stronger with this feature. The 18z NAM is still showing the wave, but not quite as robust. However with southwest flow and lingering low level moisture some showers were kept in the forecast. For the rest of Monday southerly winds will result in up-sloping flow into the northern mountains. Some light showers will be possible, but not widespread and only light accumulations are expected at best. Otherwise the southerly flow will increase temperatures across the region into the upper 40s to upper 50s. Winds will remain gusty through the day, but less then Sunday. Tuesday and Tuesday night the flow will back to almost southerly as the upper level low currently moving through the Gulf of Alaska moves off the west coast. Southerly flow with warm air advection will increase into the 50s and 60s, which are 5 to 8 degrees above normal. Moisture will increase along the Cascades through the day as the southerly flow taps into deep atmospheric river. PW`S are on the order of .50 to .60 which are 120-130 percent of normal. With the upper level flow parallel to the front it will take time for precipitation to cross the Cascade through the day on Tuesday with little eastward movement expected until later in the afternoon/evening when the following cold front moves through the region. Snow levels start out above 4000 feet across the northwest zones and over 5500 feet across the southeast Tuesday, then drop below 2500 feet behind the cold front Tuesday night. By this time, however, the heaviest precipitation should have moved east in the warm sector. As such precipitation will be mainly as rain with high elevation snow turning to snow with and behind the front. Accumulations will only be a few to several inches near the Cascade crest and less for the northern and eastern mountains. /Tobin Wednesday through Sunday: A longwave trough will settle into the region on Wednesday and remain stationary over the Interior West through much of the work-week courtesy of a blocking high, downstream across the central US/Canada. In comparison to Tuesday, temperatures will be on the downward trend with widely scattered showers possible for any location, just about every day, through Saturday; especially late afternoon coinciding with afternoon heating. Models are in pretty good agreement regarding the placement/timing of the mid-level trough but continue to struggle resolving each shortwave circulating within. We have maintained the highest PoPs across the Northeast Mountains of WA and N ID due to breezy southwest flow initially however as each of these shortwaves pivoting within the mean trough, become better resolved, we can anticipate that each shortwave will organize larger clusters of showers and moderate changes to PoPs are highly anticipated. The upper-level trough will eventually fill and become replaced by shortwave ridging as a second pacific wave or "kicker" approaches the coast over the weekend. The evolution of this wave still carries a lot of uncertainty but loose agreement indicates the potential for seasonal temperatures and dry conditions to return to close out the weekend into the start of the new week. /sb && .AVIATION... 18z TAFS: Afternoon showers will be most numerous in the Panhandle and extreme eastern WA. Gusty winds will develop at most TAF sites but should subside by late afternoon. Look for IFR cigs to develop overnight at KGEG/KSFF/KCOE but these should lift by mid-morning on Monday. RJ && .PRELIMINARY POINT TEMPS/POPS... Spokane 31 52 39 62 39 45 / 20 10 0 10 60 60 Coeur d`Alene 31 49 36 61 38 44 / 30 10 0 10 70 70 Pullman 31 52 37 63 35 42 / 20 0 0 0 70 60 Lewiston 34 59 42 67 39 48 / 10 0 0 0 60 60 Colville 31 50 37 63 37 50 / 20 20 10 20 70 60 Sandpoint 30 47 35 60 38 44 / 40 10 10 10 70 70 Kellogg 31 45 33 59 36 41 / 40 20 10 10 80 90 Moses Lake 33 57 43 62 39 56 / 10 10 10 20 60 20 Wenatchee 36 56 43 56 35 54 / 10 10 10 40 40 20 Omak 31 54 40 58 35 53 / 10 10 10 60 50 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
855 AM PDT Sun Apr 1 2012 .SYNOPSIS... A low pressure system will bring rain, mountain snow and gusty winds to the Inland Northwest today. Snow levels will be around 3000 feet today which is a lower elevation than the last few days. The cooler air mass will slow the rate of mountain snow melt, which should decrease runoff into the rivers of north Idaho. Many swollen rivers will begin to recede today. The Inland Northwest will experience a break Monday and Tuesday however cool and unsettled weather will return late Tuesday and linger through the upcoming weekend. && .DISCUSSION... Another quick update to the forecast. Intense snow shower producing some brief accumulations this morning in the metro area. But it is quickly fading on radar and moving east, so this won`t last long. As this last wave moves into the Panhandle showers will continue there all day. Tougher call is what will happen behind this wave this afternoon. On the one hand the models show dry air moving in and this is confirmed by the dropping dew points at Wenatchee, Ellensburg, and Yakima. This dry air will move east into the Spokane/Pullman area this afternoon. So that will be working against afternoon showers. The flip side is climatology and the NAM model. Typically with this set up we will see afternoon showers, although they might not produce measurable precipitation. NAM wants to do this. The last run of the HRRR (10Z) doesn`t have as much coverage but it did show the typical convergence lines of showers. So have kept in the mention of showers this afternoon/evening. These could be rain or snow with no accumulation. Last item to address is the Wind Advisory. Winds are picking up in southeast Washington and this will spread northward by mid day. The problem is that the guidance is all consistent in suggesting that winds will actually subside a bit late this afternoon, during peak heating time. This typically isn`t good for strong winds so the Advisory may have a tough time verifying in some locations. Will stick with it since it will still be windy, maybe just not as strong as previously thought. RJ && .AVIATION... 12z TAFS: Rain and snow showers will be widespread through 18z over the Idaho Panhandle and far eastern Washington including the Spokane area. Ceilings of 2000 feet or lower will likely accompany the heaviest precipitation between 14z-17z. Ceilings will likely lift quickly by late morning as gusty post-frontal winds develop from Wenatchee to Spokane to Pullman. Gusts in the 30-35kt range will be possible through 22z-24z. Winds should subside early in the evening as the surface gradient between low pressure over Montana and high pressure over Oregon weakens. /GKoch && .PRELIMINARY POINT TEMPS/POPS... Spokane 44 31 52 38 61 39 / 100 20 10 10 10 60 Coeur d`Alene 43 31 50 35 61 38 / 100 30 10 10 10 70 Pullman 43 31 53 37 61 35 / 90 20 0 0 10 70 Lewiston 49 34 60 41 66 40 / 60 10 0 0 10 60 Colville 48 31 51 36 62 37 / 100 20 30 20 40 60 Sandpoint 42 30 47 34 58 38 / 100 40 20 10 10 70 Kellogg 38 31 46 33 58 36 / 100 40 20 10 10 80 Moses Lake 55 33 58 42 64 39 / 10 10 10 10 30 50 Wenatchee 51 36 56 42 58 35 / 10 10 10 10 50 40 Omak 51 31 55 39 58 35 / 20 10 20 40 60 50 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Wind Advisory until 5 PM PDT this afternoon for Idaho Palouse. WA...Wind Advisory until 5 PM PDT this afternoon for Lower Garfield and Asotin Counties-Moses Lake Area-Upper Columbia Basin- Washington Palouse-Waterville Plateau-Wenatchee Area. && $$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
930 PM PDT SAT MAR 31 2012 .SYNOPSIS...A LOW PRESSURE SYSTEM WILL MOVE THROUGH WESTERN WASHINGTON THIS EVENING AND INLAND LATER TONIGHT. STRONG ONSHORE FLOW WILL DEVELOP LATER TONIGHT AND PERSIST THROUGH SUNDAY MORNING. A STRONG CONVERGENCE ZONE MAY GIVE HEAVY SNOW FOR THE CENTRAL CASCADES SUNDAY MORNING. A WARM FRONT WILL REACH THE AREA SUNDAY NIGHT. A STRONG WET FRONTAL SYSTEM COULD DIRECT HEAVY RAIN INTO THE OLYMPIC MOUNTAINS MONDAY AND MONDAY NIGHT. THE SECOND HALF OF THE WEEK WILL BE COOL WITH JUST SCATTERED SHOWERS. && .SHORT TERM...AT 9PM LOW PRES EXTENDS ALONG THE WA AND NRN HALF OF THE ORE COAST...THE LOW WILL SHIFT INLAND WITH STRONG ONSHORE FLOW DEVELOPING OVERNIGHT. IT WILL BE BLUSTERY LATER TONIGHT THRU SUNDAY MORNING...ALTHOUGH BECAUSE A PSCZ SETS UP OVER SEATTLE ON THE UW WRFGFS I BELIEVE THE SSW WIND THROUGH THE PUGET SOUND BASIN SHOULD NOT BE ALL THAT STRONG AS IT MIGHT IF THE GRADIENTS FROM THE RUC OR NAM SLP FCSTS VERIFY. SHOWERS ARE INCREASING THIS EVENING...AND THERE WILL BE AN ADDITIONAL BURST OF HEAVIER SHOWERS AT THE LEADING EDGE OF THE STRONG ONSHORE FLOW...ESPECIALLY THROUGH THE STRAIT AND OVER THE NW INTERIOR LATE TONIGHT AS DEPICTED IN THE UW MM5NAM...OR OVER SW WA AND THEN THE CENTRAL CASCADES AS THE WRFGFS DEPICTS. OVERALL THE BEST BET FOR HEAVY PRECIP WILL BE OVER THE CENTRAL CASCADES FROM ABOUT 3AM TO 9AM WITH THE PSCZ...AND I THINK THE SNOWFALL FORECAST FOR STEVENS AND SNOQUALMIE SHOULD PROBABLY BE SOMETHING LIKE 6-12 INCHES SUNDAY MORNING SO WE MAY NEED A SNOW ADVISORY FOR THE MAIN PASSES SUN MORNING. SHOWERS WILL LIKELY TAPER OFF LATER SUN MORNING BEFORE INCREASING AGAIN LATE IN THE AFTERNOON AND EVENING AS THE DISTURBANCE WHICH IS NEAR 137W AT 9PM REACHES WRN WA...WITH PRETTY STRONG WLY FLOW IN THE MID LEVELS AND STRONG JETSTREAM. THAT SYSTEM IS QUICKLY OVERTAKEN BY MOISTURE FROM THE NEXT FRONTAL SYSTEM AND THE WARM ADVECTION MERGES WITH IT OVER WRN WA SUN NITE. AFTER THAT THE STRONG WLY FLOW BUCKLES AND BACKS TO SSW AS THE NEXT UPPER TROUGH ARRIVES JUST OFFSHORE. THIS SYSTEM WHICH AFFECTS WRN WA ON MONDAY IS THE FRONTAL SYSTEM CURRENTLY OUT AT 155W THIS EVENING WHICH DEVELOPS VERY RAPIDLY TONIGHT WITH A DEEP LOW WHICH HAPPENS GO FROM A 998MB CENTER THIS EVENING IN THE GFS TO A 968MB CENTER APPROACHING THE CHARLOTTES BY 12Z MON. PRECIP AMOUNTS IN THE MODELS VARY. THE GFS HAS THE HEAVY RAIN GOING INTO VANCOUVER ISLAND...THE NAM ON THE OTHER HAND SHOWS 36HR PCPN OF 3-9 INCHES OVER THE OLYMPICS WHICH WOULD GIVE RIVER FLOODING FOR PROBABLY THE SATSOP AND SKOKOMISH. ALSO SEE HYDRO DISCUSSION BELOW. 19 .LONG TERM...A COOL UPPER LEVEL TROUGH WILL BE OVER THE PAC NW FOR THE SECOND HALF OF THE WEEK. THAT WILL KEEP A CHANCE OF SHOWERS IN THE FCST BUT IT WILL BE PARTLY SUNNY MOST DAYS...TEMPS WILL STAY BELOW NORMAL. THIS WILL BE A GOOD PATTERN FOR SOME LATE SEASON SKIING AND A VITAMIN D RECHARGE. 19 && .HYDROLOGY...A WET FRONTAL SYSTEM IS ON TAP FOR MON AND MONDAY NIGHT...WITH HEAVY RAIN LIKELY FOR THE OLYMPICS. THE LATEST NAM SHOWS THE CASCADES GET MUCH LESS RAIN THAN THE OLYMPICS AND RIVERS FLOWING OUT OF THE CASCADES WOULD SEE PRETTY MODEST RISES...WITH WET SNOW ABOVE ABOUT 4KFT IN THE CASCADES LIKELY. THE OLYMPICS ON THE OTHER HAND REALLY GET HIT BY THE NAM WITH 3-9 INCHES OF RAIN IN 36HRS. THE 18Z GFS HAD A MAX OF 3-6.5 INCHES...BUT THE 00Z SOLUTION PUTS ALL THE HEAVY RAIN OVER VANCOUVER ISLAND WITH JUST AN INCH OR TWO FOR THE OLYMPICS. BEST BET NOW IS FLOODING POSSIBLE FOR A FEW OLYMPIC RIVERS BUT NO SOLUTIONS SUGGEST PROBLEMS FOR CASCADE RIVERS. 19 && .AVIATION...SOUTHWESTERLY FLOW ALOFT BECOMING WESTERLY ON SUNDAY. ELONGATED SURFACE LOW OVER WESTERN WASHINGTON WILL MOVE EAST OVERNIGHT. AIR MASS UNSTABLE WITH A LARGE AREA OF SHOWERS ASSOCIATED WITH THE LOW. CEILINGS LOWERING OVERNIGHT BACK DOWN TO THE 2000-3000 FOOT RANGE WITH THE INCREASING SHOWERS. AS THE SURFACE LOW MOVES EAST OF THE CASCADES AND HIGH PRESSURE BUILDS ALONG THE COAST STRONG ONSHORE FLOW WILL DEVELOP SUNDAY MORNING. THIS WILL GENERALLY KEEP CEILINGS IN THE 2000-3000 FOOT RANGE. A SHORTWAVE TROUGH MOVING QUICKLY IN THE JET STREAM SHOULD ENHANCE SHOWERS OVER THE AREA AGAIN SUNDAY AFTERNOON KEEPING AT LEAST AREAS OF CEILINGS IN THE 2000-3000 FOOT RANGE. SOME IMPROVEMENT LATE SUNDAY AFTERNOON INTO SUNDAY EVENING ESPECIALLY OVER THE CENTRAL PUGET SOUND WITH THE INCREASING WESTERLY FLOW ALOFT. KSEA...LIGHT WIND BECOMING SOUTHERLY 4 TO 8 KNOTS AFTER 09Z. SOUTHERLY WINDS INCREASING QUICKLY AROUND 15Z TO THE 15 GUST 25 KNOT RANGE. WINDS EASING IN THE AFTERNOON. CEILINGS BOUNCING AROUND WITH THE SHOWER ACTIVITY WITH MVFR CEILINGS A MAJORITY OF THE TIME ESPECIALLY AFTER 12Z. FELTON && .MARINE...ELONGATED SURFACE LOW OVER THE INTERIOR OF WESTERN WESTERN SHIFTING EAST OF THE CASCADES OVERNIGHT. STRONG SOUTHWEST ONSHORE PUSH DEVELOPS SUNDAY MORNING...WITH GALES LIKELY FOR THE FIRST HALF OF THE DAY FOR THE CENTRAL/EAST ENTRANCE AND HIGHER END SCA LEVEL WINDS OVER OTHER WATERS. GRADIENTS WILL BRIEFLY EASE SUNDAY AFTERNOON AS AN UPPER LEVEL DISTURBANCE SLIDING OVER SOUTHERN WASHINGTON IN THE AFTERNOON HELPS TO DECREASE ONSHORE GRADIENTS. A STRONG FRONTAL SYSTEM IS PEGGED TO REACH THE AREA ON MONDAY. 00Z GFS MODEL STILL SHOWS WARM FRONT LIFTING OVER THE AREA SUNDAY NIGHT...WITH INCREASINGLY S-SE WINDS OVER THE COAST AND USUAL INTERIOR ZONES. GALE WATCH WILL REMAIN IN EFFECT FOR THE COASTAL WATERS...NORTHERN INLAND WATERS...AND EAST ENTRANCE. FELTON && .SEW WATCHES/WARNINGS/ADVISORIES... WA...FLOOD ADVISORY REMAINS IN EFFECT FOR THE CHEHALIS RIVER NEAR GRAND MOUND IN THURSTON COUNTY. PZ...GALE WARNING IN EFFECT FROM 2 AM TO 5 PM PDT SUNDAY FOR THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS...WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA... NORTHERN INLAND WATERS...ADMIRALTY INLET...AND PUGET SOUND/ HOOD CANAL. SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 11 PM PDT SUNDAY FOR THE GRAYS HARBOR BAR. GALE WATCH IN EFFECT FROM SUNDAY EVENING THROUGH MONDAY EVENING FOR THE COASTAL WATERS...ADMIRALTY INLET... ENTRANCES TO THE STRAIT OF JUAN DE FUCA...AND NORTHERN INLAND WATERS. && $$ WWW.WEATHER.GOV/SEATTLE FOR THE GRAPHICAL AFD VISIT... WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
644 PM CDT MON APR 2 2012 .SHORT TERM...THROUGH WEDNESDAY NIGHT 249 PM CDT MON APR 2 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT INTO TUESDAY. SURFACE ANALYSIS THIS AFTERNOON SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SOUTH DAKOTA. A WARM FRONT EXTENDED SOUTHEAST FROM THE LOW ACROSS IOWA INTO CENTRAL ILLINOIS. WATER VAPOR SATELLITE SHOWS UPPER LEVEL RIDGING REMAINS OVER THE UPPER MIDWEST TODAY. THE CONCERN FOR TONIGHT IS WHAT IS GOING TO HAPPEN TO THIS RIDGE. THE CONSENSUS OF THE 02.12Z MODELS IS THAT IT IS PRETTY MUCH GOING TO STAY IN PLACE AS IT IS BLOCKED FROM MOVING EAST BY A LONG WAVE TROUGH JUST OFF THE EAST COAST. HOWEVER...THE NORTHERN EXTENT OF THE RIDGE SHOULD GET FLATTENED SOME AS THE NORTHERN STREAM SYSTEM OVER SOUTHERN CANADA CONTINUES TO MOVE EAST PRODUCING SOME HEIGHT FALLS OVER NORTHERN MINNESOTA AND WISCONSIN. THE 02.00Z ECMWF HAS BEEN THE MOST CONSISTENT WITH THE HANDLING OF THIS SYSTEM AND THE 02.12Z NAM NOW HAS COME INTO GOOD AGREEMENT WITH THE ECMWF. AS THE SHORT WAVE TROUGH MOVES BY LATE TONIGHT...IT WILL PRODUCE THOSE MINOR HEIGHT FALLS WITH POSSIBLY UP TO 2 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER ACROSS NORTHERN WISCONSIN. THE SURFACE LOW IS EXPECTED TO EITHER TRACK ACROSS SOUTHERN MINNESOTA OR NORTHERN IOWA AS IT MOVES TOWARD NORTHERN ILLINOIS BY TUESDAY MORNING. THIS SHOULD ALLOW THE WARM FRONT TO GET LIFTED INTO THE SOUTHERN PORTIONS OF THE FORECAST AREA WITH WEAK TO MODERATE FRONTOGENESIS OCCURRING NORTH OF THE FRONT LATE TONIGHT. THE WARM AIR ADVECTION OVER THE WARM FRONT WILL PRODUCE PERSISTENT UP GLIDE OF 1 TO 4 UBAR/S ON THE 305K ISENTROPIC SURFACE. A LOT OF THIS UP GLIDE WILL INITIALLY GO INTO SATURATION AND BY THE TIME SATURATION OCCURS THE BEST UP GLIDE WILL BE MOVING OFF TO THE EAST OF THE AREA. THE WILD CARD IN WHERE THE CONVECTION WILL DEVELOP TONIGHT IS THE WARM FRONT. THE 02.12Z GFS HAS BEEN CONSISTENTLY FARTHER SOUTH WITH THE NOSE OF THE MOISTURE TRANSPORT AND LOW LEVEL JET INTO THE FRONT AROUND THE I90 CORRIDOR. THE NAM AND ECMWF INDICATE THE LOW LEVEL JET AND MOISTURE TRANSPORT WILL CONTINUE PAST THE FRONT AND CONTINUE FARTHER NORTH CLOSER TO THE SHORT WAVE TROUGH. THIS SCENARIO HAS MOST OF THE CONVECTION DEVELOPING ACROSS THE NORTHERN PARTS OF THE AREA INTO NORTHERN WISCONSIN AND THEN TRANSLATING INTO NORTHEAST AND EASTERN WISCONSIN AS THE LOW LEVEL JET BENDS OVER TO THE EAST. THE NAM SUGGESTS THERE COULD BE AROUND 750 J/KG OF ELEVATED CAPE ABOVE 2KM FOR THE STORMS TO WORK WITH. THE 0-3KM SHEAR SHOULD BE AROUND 30 TO 35 KNOTS BUT TAKING OUT THE LOWEST 1KM OF THIS SINCE THE STORMS WILL BE ELEVATED BRINGS THIS DOWN TO 15 TO 20 KNOTS. THIS IS NOT EXPECTED TO BE ENOUGH SHEAR TO ALLOW THE STORMS THAT FORM TO PRODUCE ANY SEVERE WEATHER BUT WITH PRECIPITABLE WATERS EXPECTED TO BE 200-250 PERCENT OF NORMAL...CAN NOT RULE OUT SOME LOCALIZED HEAVY RAINS. THE 02.12Z HIRES ARW AND NMM ALONG WITH THE 02.16Z HRRR ARE IN VERY GOOD AGREEMENT WITH THE NAM AND ECMWF INITIATING THE CONVECTION THIS EVENING FARTHER TO THE NORTH AS THE MOISTURE TRANSPORT OVERRUNS THE WARM FRONT. HAVE THUS MAINTAINED THE IDEA THAT THE BEST CHANCES FOR CONVECTION WILL BE ACROSS THE NORTHERN PARTS OF THE AREA AND AFTER MIDNIGHT AS THE WEAK FORCING FROM THE SHORT WAVE TROUGH APPROACHES. WILL KEEP A SMALL CHANCE OF RAIN IN THE FORECAST FOR THIS EVENING AS THE WARM FRONT APPROACHES ACROSS MOST OF THE AREA. MAINTAINED THE 30 TO 50 PERCENT CHANCES FOR AFTER MIDNIGHT TAPERING BACK TO JUST A 20 PERCENT CHANCE ACROSS THE EAST TUESDAY MORNING FOR ANY LINGERING SHOWERS. THE FRONT SHOULD BE FAR ENOUGH SOUTH TO HAVE A DRY TUESDAY AFTERNOON. AFTER THAT...HIGH PRESSURE WILL BUILD IN TO BRING SOME COOLER TEMPERATURES AND DRIER AIR. DID NOT ADD ANY FROST TO THE FORECAST FOR TUESDAY NIGHT OR WEDNESDAY NIGHT AS TEMPERATURES AND DEW POINTS ARE EXPECTED TO MAINTAIN A 5 TO 10 DEGREE SPREAD. THERE SHOULD ALSO BE SOME WINDS BOTH NIGHT TO CREATE SOME MIXING AND THE COMBINATION OF THE WINDS AND DRIER AIR SHOULD PRECLUDE FROST FORMATION. PORTIONS OF CENTRAL WISCONSIN NORTH OF THE I94 CORRIDOR COULD POSSIBLY SEE SOME FREEZING TEMPERATURES BOTH OF THESE NIGHTS. .LONG TERM...THURSDAY THROUGH MONDAY 249 PM CDT MON APR 2 2012 THE HIGH WILL REMAIN OVER THE REGION THROUGH FRIDAY MAINTAINING THE POSSIBILITY OF SOME FROST AND FREEZING TEMPERATURES AT NIGHT FOR THE END OF THE WEEK. THE HIGH WILL THEN MOVE OFF FOR THE WEEKEND AS THE NEXT SYSTEM COMES INTO THE AREA. SOME TIMING DIFFERENCES BETWEEN THE 02.12Z GFS...ECMWF AND GEM WITH THE COLD FRONT COMING ACROSS. THE ECMWF AND GEM ARE A LITTLE FASTER BUT ALL SHOW AT LEAST A CHANCE FOR SOME RAIN SATURDAY INTO SATURDAY NIGHT BEFORE IT MOVES OFF TO THE EAST FOR SUNDAY. SOME DIFFERENCES FOR NEXT MONDAY WITH THE ECMWF DROPPING ANOTHER SHORT WAVE TROUGH OVER THE AREA FOR THE POSSIBILITY OF SOME SHOWERS WHILE THE GFS IS DRY WITH HIGH PRESSURE BUILDING IN. WILL HONOR THE ECMWF WITH A SMALL RAIN CHANCE FOR MONDAY. && .AVIATION...TONIGHT AND TUESDAY 643 PM CDT MON APR 2 2012 MAIN FORECAST CONCERN IS CLOUD TRENDS THROUGH THE PERIOD...AND PRECIPITATION CHANCES TONIGHT THROUGH TOMORROW MORNING. CURRENTLY SCATTERED VFR DECK BETWEEN 3000-4000 FT DEVELOPING ACROSS PARTS OF SOUTHEAST MINNESOTA AND WESTERN WISCONSIN...AND EXPECT THIS TO BE IN VICINITY OF KRST/KLSE THROUGH EARLY EVENING HOURS. INCREASED MOISTURE TRANSPORT SHOULD LEAD TO AN EXPANSION OF CLOUD COVER LATER TONIGHT...WITH SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING. BEST FORCING/LIFT REMAINS JUST NORTH OF THE TAF SITES...THUS KEPT VCSH MENTION STARTING 03.08Z AT KRST AND 03.10Z AT KLSE. CLOUDS WILL LOWER TO MVFR OVERNIGHT THROUGH EARLY TUESDAY MORNING BEFORE COLD FRONT SWEEPS THROUGH...TURNING WINDS TO NORTHWEST. PLENTY OF MVFR STRATUS ALONG AND BEHIND THIS FRONT RIGHT NOW...EVEN SOME IFR ACROSS EASTERN SOUTH DAKOTA. CLOUDS WILL PERSIST THROUGH THE DAY TUESDAY...BUT AS DRIER AIR WORKS IN...CLOUDS WILL BEGIN TO LIFT TO VFR / 4000 TO 5000 FT / BY LATE AFTERNOON. INCLUDED MENTION OF GUSTY WINDS / 20 TO 25 KTS / AS PRESSURE GRADIENT WILL REMAIN TIGHT THROUGH SUNSET. && .ARX WATCHES/WARNINGS/ADVISORIES... 249 PM CDT MON APR 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...ZT/BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 AM CDT SUN APR 1 2012 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT 325 AM CDT SUN APR 1 2012 MAIN FORECAST CONCERNS ARE ON STRATUS TRENDS TODAY...AS WELL AS PRECIPITATION CHANCES TONIGHT THROUGH MONDAY NIGHT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED DEEP TROUGHING ALONG THE WEST COAST OF THE U.S....BUILDING RIDGING DOWNSTREAM ACROSS THE PLAINS INTO MANITOBA...AND TROUGHING OVER SOUTHEAST CANADA. WITHIN THIS LATTER TROUGHING...A STRONG SHORTWAVE WAS DROPPING SOUTHEAST THROUGH NORTHERN ONTARIO. WITH THE BUILDING RIDGING/HEIGHTS AT 500MB TAKING PLACE NEAR AND WEST OF THE FORECAST AREA...A WARM ADVECTION PATTERN IS IN PLACE. SOUNDINGS AT GRB AND MPX REFLECT THIS...SHOWING 850MB TEMPS THAT ROSE TO 9C AT 15C RESPECTIVELY AT 00Z...COMPARED TO -2C AND 9C AT 12Z YESTERDAY. THE WARM ADVECTION OCCURRING ALOFT WAS A PROBLEM GETTING RID OF THE STRATUS DURING THE DAY YESTERDAY...PLUS THE DEPTH OF THE STRATUS AT 12Z WAS 75MB...BOTH MAKING IT TOUGHER TO MIX OUT. DURING THE EVENING...INCREASING 925MB WINDS OF 30-40KT HELPED TO BRING DRIER AIR BELOW 900MB SEEN ON THE 00Z DVN SOUNDING NORTHWARD...WHICH HAS CLEARED OUT THE LOW CLOUDS UP TO A FARIBAULT MN TO OSHKOSH WI LINE. SEEING SOME FOG DEVELOP IN THE CLEARING AREA. ACROSS NORTHERN WISCONSIN...925MB WINDS HAVE TURNED NORTHWEST...IN THE WAKE OF A COLD FRONT ABOVE THE SURFACE ASSOCIATED WITH THAT NORTHERN ONTARIO SHORTWAVE. BACK FARTHER TO THE SOUTH...CONVECTION ROLLED EAST ACROSS FAR SOUTHERN WISCONSIN...EASTERN IOWA INTO NORTHERN ILLINOIS OVERNIGHT...ON THE NOSE OF A LOW LEVEL JET AND SURFACE WARM FRONT WHICH SITS NOW NEAR I-80. TODAY AND TONIGHT...UPPER RIDGING SEEN BUILDING OVER THE PLAINS WILL SHIFT EAST THROUGH TONIGHT WITH THE AXIS RIGHT OVER THE FORECAST AREA AT 12Z. WITH THE UPPER FLOW GAINING A LITTLE MORE AMPLITUDE...THAT COLD FRONT SEEN IN 925MB PROFILER/VWP DATA LOOKS TO DROP SOUTH THROUGH MUCH OF THE FORECAST AREA BETWEEN 12-18Z. THE FRONT THEN STALLS OUT FOR THE AFTERNOON FROM SOUTHWEST MINNESOTA INTO NORTHERN ILLINOIS. WITH THE 925MB WINDS VEERING NORTHEASTERLY THEN SOUTHEASTERLY BEHIND THIS FRONT...THE STRATUS WILL MAKE ITS WAY BACK SOUTH ACROSS WISCONSIN PORTIONS OF THE FORECAST AREA. QUESTION THEN BECOMES FOR THE AFTERNOON...DOES THE STRATUS MIX OUT? FOR YESTERDAY...THE 31.00Z NAM AND 31.00-07Z RUC MODELS...AS WELL AS THE HRRR...WERE ALL SAYING THE STRATUS WOULD MIX OUT BY 19Z. SEEING THE SAME THING FROM THESE MODELS TODAY. ONE ADVANTAGE TO CLEARING IS THAT DRIER AIR IS LOWER IN THE ATMOSPHERE COMPARED TO THIS TIME YESTERDAY...NOTED BETWEEN THE 12Z AND 00Z GRB SOUNDING. THIS DRIER AIR LOOKS TO CONTINUE TO SINK TOWARDS THE SURFACE TODAY WHILE MIXING OCCURS. THE COMBINATION OF THE TWO SHOULD BE ABLE TO SCOUR OUT THE STRATUS. WITH THE STRATUS CONCERNS...HAVE LOWERED TEMPERATURES CLOSER TO THE NAM12 AND REGIONAL CANADIAN 2 METER OUTPUT...WHICH SEEMS REASONABLE. CERTAINLY IF CLOUDS STICK AROUND LONGER LIKE YESTERDAY...THESE STILL MAY BE TOO HIGH. HOWEVER...DO NOT WANT TO DROP TOO MUCH GIVEN ANY SUN AND 850MB TEMPS OF 12-16C COULD EASILY JUMP TEMPERATURES WELL INTO THE 70S. TONIGHT...THE LINGERING MOISTURE COULD REDEVELOP OR EXPAND INTO A STRATUS DECK WEST OF THE MISSISSIPPI RIVER AS THE 925MB WINDS INCREASE OUT OF THE SOUTHEAST. THE INCREASING WINDS ARE IN RESPONSE TO DEEPENING LOW PRESSURE OVER NEBRASKA WITH AN INVERTED TROUGH EXTENDING NORTHEAST THROUGH WESTERN MINNESOTA. SHOULD SEE A SURGE OF ISENTROPIC LIFT WITH THIS SYSTEM AS WELL...WHICH SHOWS UP WELL ON 305K SURFACES IN THE 06-12Z MONDAY TIME PERIOD FROM LA CROSSE SOUTHWESTWARD. SOUNDINGS CONTINUE TO SUGGEST A CAPPING INVERSION AT 750MB TO PREVENT ACCAS THAT DEVELOPS FROM THE LIFT INTO BECOMING DEEP CONVECTION. WILL CONTINUE THE DRY FORECAST...BUT MONITORING OF THIS CAP IS NEEDED. FURTHER NORTH... MODELS WERE SUGGESTING BEFORE CONVECTION POSSIBLY INTO TAYLOR COUNTY. THIS IS NOW PROGGED TO STAY WELL OFF TO THE NORTHWEST...UP NEAR DULUTH. THEREFORE HAVE PULLED THE 20 PERCENT CHANCES. MONDAY THROUGH TUESDAY NIGHT...THE UPPER RIDGE OVER THE FORECAST AREA IS PROGGED TO SLOWLY FALL APART...IN RESPONSE TO THE NORTHERN PORTION OF THE CURRENT WESTERN TROUGH CROSSING FROM THE NORTHERN PLAINS THROUGH THE WESTERN GREAT LAKES. THE TIMING OF THE NORTHERN FEATURE CONTINUES TO BE A PROBLEM...WITH THE ECMWF/UKMET/CANADIAN CONSISTENTLY REMAINING SLOWER THAN THE NAM/GFS. THIS HAS SIGNIFICANT IMPLICATIONS ON TEMPERATURES AND ANY PRECIP TIMING. TRENDS IN THE NAM/GFS SINCE THE 31.00Z RUNS HAVE SHOWN SOME SLOWING...THEREFORE HAVE BIASED THE FORECAST TOWARDS THE SLOWER ECMWF/UKMET/CANADIAN. ALL MODELS ARE SUGGESTING A DRIER FORECAST MONDAY...ESPECIALLY DURING THE MORNING...AS ALL SYNOPTIC FORCING IS EITHER ACROSS NORTHERN MINNESOTA OR BACK IN THE FRONTOGENETIC AREA BEHIND THE INVERTED TROUGH CROSSING MINNESOTA. HAVE REDUCED PRECIPITATION CHANCES SOME FOR MONDAY AND LATER FORECASTS MAY BE ABLE TO COMPLETELY DRY IT OUT. WITH THE TRACK OF THE UPPER TROUGH...BEST DPVA FORCING SHOULD CONTINUE TO STAY MORE TOWARDS THE NORTH FOR MONDAY NIGHT. AS SUCH...WHEN YOU LOOK AT MODEL QPF FIELDS...MOST OF THE QPF ENDS UP NORTH OF I-94. PLUS...500MB HEIGHT FALLS ARE ONLY 10-20 METERS TOPS FROM I-90 SOUTH. THEREFORE...REDUCED MONDAY NIGHTS CHANCES ABOUT 10 PERCENT SOUTH OF I-90 AND KEPT 50 CHANCES GOING NORTH OF I-94. SPC CONTINUES TO SHOW A 5% CHANCE OF SEVERE WEATHER FOR MONDAY AND MONDAY NIGHT...BUT CONFIDENCE IS REALLY LOW WITH PRECIPITATION IN THE FIRST PLACE SEEING MODEL TRENDS TOWARDS DRIER OVERALL. INVERTED TROUGH SHOULD HAVE PUSHED THROUGH THE AREA MONDAY NIGHT...ALLOWING A COOLER...DRIER AREA OF HIGH PRESSURE TO BUILD IN FOR TUESDAY AND TUESDAY NIGHT. PREVIOUS FORECAST OF DRY CONDITIONS FOR THIS TIME PERIOD STILL LOOKS GOOD...AS WELL AS THE TEMPERATURES. REGARDING TEMPERATURES MONDAY AND MONDAY NIGHT...THESE ARE TRICKY AS ALREADY MENTIONED TIMING OF THE TROUGH IS CRITICAL. THERE COULD ALSO BE SOME STRATUS AND/OR ACCAS TO DEAL WITH MONDAY. LASTLY...THE WIND FLOW MONDAY IS STILL EAST TO SOUTHEAST. ON THE OTHER HAND...850MB TEMPS ARE 12-16C. FOR NOW COOLED HIGHS ACROSS WISCONSIN WITH MORE CLOUDS AND CLOSER TO EASTERLY FLOW. LOCATIONS LIKE OELWEIN AND CHARLES CITY COULD HIT 80...THOUGH. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 325 AM CDT SUN APR 1 2012 01.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT OF AN OMEGA BLOCK PATTERN OVER CANADA AND THE U.S. FOR WEDNESDAY THROUGH FRIDAY...THEN BEGINS TO BREAK DOWN HEADING INTO THE WEEKEND. THE FORECAST AREA LIES EAST OF THE RIDGE AXIS IN THE OMEGA BLOCK... WHICH IS IN THE DAKOTAS AND MINNESOTA THROUGH EARLY FRIDAY. THIS FAVORS A RIDGE OF HIGH PRESSURE AT THE SURFACE WITH A COOL/DRY AIR FEED OUT OF CANADA. STILL...TEMPERATURES LOOK LIKE THEY SHOULD END UP A BIT ABOVE NORMAL. MAY HAVE TO DEAL WITH FROST FOR A FEW NIGHTS...THOUGH. SOME WARMING SHOULD OCCUR ON FRIDAY AS THE UPPER RIDGE AXIS MOVES IN AND THE SURFACE RIDGE MOVES EAST... ALLOWING A SOUTHERLY RETURN FLOW TO DEVELOP. FOR THE WEEKEND...TROUGHING OVER THE WESTERN U.S. IS EXPECTED TO EJECT OUT INTO THE NORTHERN PLAINS...BRINGING A COLD FRONT INTO OR THROUGH THE FORECAST AREA SATURDAY NIGHT. ENVISION THE WEEKEND TIMING OF ALL THIS WILL GET ADJUSTED OVER THE COMING DAYS...AND HAVE SOME CONCERN THE MAJORITY OF MODELS INCLUDING THE 01.00Z ECMWF ARE TOO FAST WITH THIS TIMING GIVEN THE DOWNSTREAM RIDGE. THEREFORE...PRECIPITATION CHANCES WITH THE WARM CONVEYOR BELT AHEAD OF THE COLD FRONT ARE HELD TO 20-30 AT THIS TIME. DID NOT INTRODUCE ANY THUNDER BECAUSE THERE APPEARS TO BE LIMITED INSTABILITY AT THIS TIME. TEMPERATURES SHOULD STAY ABOVE NORMAL FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT...UNTIL THE COLD FRONT PASSES. EVEN BEHIND IT...READINGS COULD STAY NEAR OR ABOVE NORMAL. && .AVIATION...TODAY AND TONIGHT 635 AM CDT SUN APR 1 2012 LIFR/VLIFR CONDITIONS IN FOG/STRATUS CAN BE EXPECTED ACROSS SOUTHEAST MINNESOTA THROUGH MID MORNING. PLAN ON VISIBILITIES OF 1/2 MILE IN FOG AT KRST...WITH CEILINGS AT 200FT. LOOK FOR THESE CONDITIONS TO GRADUALLY START TO IMPROVE AROUND 14Z...WITH VFR CONDITIONS EXPECTED BY 16Z. MVFR VISIBILITIES AT KLSE WILL QUICKLY IMPROVE THIS MORNING WITH VFR CONDITIONS ANTICIPATED BY 14Z. STRATUS WILL PRODUCE CLOUD BASES IN THE 3 TO 4 KFT RANGE THROUGH MID MORNING BEFORE DISSIPATING. VFR CONDITIONS CAN BE EXPECTED AT THE TAF SITE THIS AFTERNOON INTO THIS EVENING. SOUTHEAST WINDS ARE EXPECTED TO INCREASE INTO THE 8 TO 16 KT RANGE THIS EVENING AS LOW PRESSURE DEVELOPS OVER THE CENTRAL PLAINS. WILL HAVE TO KEEP A CLOSE WATCH ON LOW LEVEL WIND SHEAR POTENTIAL TONIGHT...WITH WINDS AROUND 1500 FT INCREASING TO 45 KTS. IN ADDITION...FORECAST SOUNDINGS ARE SHOWING THE POTENTIAL FOR AN MVFR STRATUS DECK TO DEVELOP AT KLSE AND KRST AS SOUTHEAST WINDS ADVECT 925 MB MOISTURE INTO THE AREA. WILL ALSO HAVE TO MONITOR THIS POTENTIAL VERY CLOSELY TODAY. IF THE STRATUS DEVELOPS...CLOUD BASES WILL LOWER TO AROUND 1500 FT. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 AM CDT SUN APR 1 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 AM CDT SUN APR 1 2012 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT 325 AM CDT SUN APR 1 2012 MAIN FORECAST CONCERNS ARE ON STRATUS TRENDS TODAY...AS WELL AS PRECIPITATION CHANCES TONIGHT THROUGH MONDAY NIGHT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED DEEP TROUGHING ALONG THE WEST COAST OF THE U.S....BUILDING RIDGING DOWNSTREAM ACROSS THE PLAINS INTO MANITOBA...AND TROUGHING OVER SOUTHEAST CANADA. WITHIN THIS LATTER TROUGHING...A STRONG SHORTWAVE WAS DROPPING SOUTHEAST THROUGH NORTHERN ONTARIO. WITH THE BUILDING RIDGING/HEIGHTS AT 500MB TAKING PLACE NEAR AND WEST OF THE FORECAST AREA...A WARM ADVECTION PATTERN IS IN PLACE. SOUNDINGS AT GRB AND MPX REFLECT THIS...SHOWING 850MB TEMPS THAT ROSE TO 9C AT 15C RESPECTIVELY AT 00Z...COMPARED TO -2C AND 9C AT 12Z YESTERDAY. THE WARM ADVECTION OCCURRING ALOFT WAS A PROBLEM GETTING RID OF THE STRATUS DURING THE DAY YESTERDAY...PLUS THE DEPTH OF THE STRATUS AT 12Z WAS 75MB...BOTH MAKING IT TOUGHER TO MIX OUT. DURING THE EVENING...INCREASING 925MB WINDS OF 30-40KT HELPED TO BRING DRIER AIR BELOW 900MB SEEN ON THE 00Z DVN SOUNDING NORTHWARD...WHICH HAS CLEARED OUT THE LOW CLOUDS UP TO A FARIBAULT MN TO OSHKOSH WI LINE. SEEING SOME FOG DEVELOP IN THE CLEARING AREA. ACROSS NORTHERN WISCONSIN...925MB WINDS HAVE TURNED NORTHWEST...IN THE WAKE OF A COLD FRONT ABOVE THE SURFACE ASSOCIATED WITH THAT NORTHERN ONTARIO SHORTWAVE. BACK FARTHER TO THE SOUTH...CONVECTION ROLLED EAST ACROSS FAR SOUTHERN WISCONSIN...EASTERN IOWA INTO NORTHERN ILLINOIS OVERNIGHT...ON THE NOSE OF A LOW LEVEL JET AND SURFACE WARM FRONT WHICH SITS NOW NEAR I-80. TODAY AND TONIGHT...UPPER RIDGING SEEN BUILDING OVER THE PLAINS WILL SHIFT EAST THROUGH TONIGHT WITH THE AXIS RIGHT OVER THE FORECAST AREA AT 12Z. WITH THE UPPER FLOW GAINING A LITTLE MORE AMPLITUDE...THAT COLD FRONT SEEN IN 925MB PROFILER/VWP DATA LOOKS TO DROP SOUTH THROUGH MUCH OF THE FORECAST AREA BETWEEN 12-18Z. THE FRONT THEN STALLS OUT FOR THE AFTERNOON FROM SOUTHWEST MINNESOTA INTO NORTHERN ILLINOIS. WITH THE 925MB WINDS VEERING NORTHEASTERLY THEN SOUTHEASTERLY BEHIND THIS FRONT...THE STRATUS WILL MAKE ITS WAY BACK SOUTH ACROSS WISCONSIN PORTIONS OF THE FORECAST AREA. QUESTION THEN BECOMES FOR THE AFTERNOON...DOES THE STRATUS MIX OUT? FOR YESTERDAY...THE 31.00Z NAM AND 31.00-07Z RUC MODELS...AS WELL AS THE HRRR...WERE ALL SAYING THE STRATUS WOULD MIX OUT BY 19Z. SEEING THE SAME THING FROM THESE MODELS TODAY. ONE ADVANTAGE TO CLEARING IS THAT DRIER AIR IS LOWER IN THE ATMOSPHERE COMPARED TO THIS TIME YESTERDAY...NOTED BETWEEN THE 12Z AND 00Z GRB SOUNDING. THIS DRIER AIR LOOKS TO CONTINUE TO SINK TOWARDS THE SURFACE TODAY WHILE MIXING OCCURS. THE COMBINATION OF THE TWO SHOULD BE ABLE TO SCOUR OUT THE STRATUS. WITH THE STRATUS CONCERNS...HAVE LOWERED TEMPERATURES CLOSER TO THE NAM12 AND REGIONAL CANADIAN 2 METER OUTPUT...WHICH SEEMS REASONABLE. CERTAINLY IF CLOUDS STICK AROUND LONGER LIKE YESTERDAY...THESE STILL MAY BE TOO HIGH. HOWEVER...DO NOT WANT TO DROP TOO MUCH GIVEN ANY SUN AND 850MB TEMPS OF 12-16C COULD EASILY JUMP TEMPERATURES WELL INTO THE 70S. TONIGHT...THE LINGERING MOISTURE COULD REDEVELOP OR EXPAND INTO A STRATUS DECK WEST OF THE MISSISSIPPI RIVER AS THE 925MB WINDS INCREASE OUT OF THE SOUTHEAST. THE INCREASING WINDS ARE IN RESPONSE TO DEEPENING LOW PRESSURE OVER NEBRASKA WITH AN INVERTED TROUGH EXTENDING NORTHEAST THROUGH WESTERN MINNESOTA. SHOULD SEE A SURGE OF ISENTROPIC LIFT WITH THIS SYSTEM AS WELL...WHICH SHOWS UP WELL ON 305K SURFACES IN THE 06-12Z MONDAY TIME PERIOD FROM LA CROSSE SOUTHWESTWARD. SOUNDINGS CONTINUE TO SUGGEST A CAPPING INVERSION AT 750MB TO PREVENT ACCAS THAT DEVELOPS FROM THE LIFT INTO BECOMING DEEP CONVECTION. WILL CONTINUE THE DRY FORECAST...BUT MONITORING OF THIS CAP IS NEEDED. FURTHER NORTH... MODELS WERE SUGGESTING BEFORE CONVECTION POSSIBLY INTO TAYLOR COUNTY. THIS IS NOW PROGGED TO STAY WELL OFF TO THE NORTHWEST...UP NEAR DULUTH. THEREFORE HAVE PULLED THE 20 PERCENT CHANCES. MONDAY THROUGH TUESDAY NIGHT...THE UPPER RIDGE OVER THE FORECAST AREA IS PROGGED TO SLOWLY FALL APART...IN RESPONSE TO THE NORTHERN PORTION OF THE CURRENT WESTERN TROUGH CROSSING FROM THE NORTHERN PLAINS THROUGH THE WESTERN GREAT LAKES. THE TIMING OF THE NORTHERN FEATURE CONTINUES TO BE A PROBLEM...WITH THE ECMWF/UKMET/CANADIAN CONSISTENTLY REMAINING SLOWER THAN THE NAM/GFS. THIS HAS SIGNIFICANT IMPLICATIONS ON TEMPERATURES AND ANY PRECIP TIMING. TRENDS IN THE NAM/GFS SINCE THE 31.00Z RUNS HAVE SHOWN SOME SLOWING...THEREFORE HAVE BIASED THE FORECAST TOWARDS THE SLOWER ECMWF/UKMET/CANADIAN. ALL MODELS ARE SUGGESTING A DRIER FORECAST MONDAY...ESPECIALLY DURING THE MORNING...AS ALL SYNOPTIC FORCING IS EITHER ACROSS NORTHERN MINNESOTA OR BACK IN THE FRONTOGENETIC AREA BEHIND THE INVERTED TROUGH CROSSING MINNESOTA. HAVE REDUCED PRECIPITATION CHANCES SOME FOR MONDAY AND LATER FORECASTS MAY BE ABLE TO COMPLETELY DRY IT OUT. WITH THE TRACK OF THE UPPER TROUGH...BEST DPVA FORCING SHOULD CONTINUE TO STAY MORE TOWARDS THE NORTH FOR MONDAY NIGHT. AS SUCH...WHEN YOU LOOK AT MODEL QPF FIELDS...MOST OF THE QPF ENDS UP NORTH OF I-94. PLUS...500MB HEIGHT FALLS ARE ONLY 10-20 METERS TOPS FROM I-90 SOUTH. THEREFORE...REDUCED MONDAY NIGHTS CHANCES ABOUT 10 PERCENT SOUTH OF I-90 AND KEPT 50 CHANCES GOING NORTH OF I-94. SPC CONTINUES TO SHOW A 5% CHANCE OF SEVERE WEATHER FOR MONDAY AND MONDAY NIGHT...BUT CONFIDENCE IS REALLY LOW WITH PRECIPITATION IN THE FIRST PLACE SEEING MODEL TRENDS TOWARDS DRIER OVERALL. INVERTED TROUGH SHOULD HAVE PUSHED THROUGH THE AREA MONDAY NIGHT...ALLOWING A COOLER...DRIER AREA OF HIGH PRESSURE TO BUILD IN FOR TUESDAY AND TUESDAY NIGHT. PREVIOUS FORECAST OF DRY CONDITIONS FOR THIS TIME PERIOD STILL LOOKS GOOD...AS WELL AS THE TEMPERATURES. REGARDING TEMPERATURES MONDAY AND MONDAY NIGHT...THESE ARE TRICKY AS ALREADY MENTIONED TIMING OF THE TROUGH IS CRITICAL. THERE COULD ALSO BE SOME STRATUS AND/OR ACCAS TO DEAL WITH MONDAY. LASTLY...THE WIND FLOW MONDAY IS STILL EAST TO SOUTHEAST. ON THE OTHER HAND...850MB TEMPS ARE 12-16C. FOR NOW COOLED HIGHS ACROSS WISCONSIN WITH MORE CLOUDS AND CLOSER TO EASTERLY FLOW. LOCATIONS LIKE OELWEIN AND CHARLES CITY COULD HIT 80...THOUGH. .LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT 325 AM CDT SUN APR 1 2012 01.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT OF AN OMEGA BLOCK PATTERN OVER CANADA AND THE U.S. FOR WEDNESDAY THROUGH FRIDAY...THEN BEGINS TO BREAK DOWN HEADING INTO THE WEEKEND. THE FORECAST AREA LIES EAST OF THE RIDGE AXIS IN THE OMEGA BLOCK... WHICH IS IN THE DAKOTAS AND MINNESOTA THROUGH EARLY FRIDAY. THIS FAVORS A RIDGE OF HIGH PRESSURE AT THE SURFACE WITH A COOL/DRY AIR FEED OUT OF CANADA. STILL...TEMPERATURES LOOK LIKE THEY SHOULD END UP A BIT ABOVE NORMAL. MAY HAVE TO DEAL WITH FROST FOR A FEW NIGHTS...THOUGH. SOME WARMING SHOULD OCCUR ON FRIDAY AS THE UPPER RIDGE AXIS MOVES IN AND THE SURFACE RIDGE MOVES EAST... ALLOWING A SOUTHERLY RETURN FLOW TO DEVELOP. FOR THE WEEKEND...TROUGHING OVER THE WESTERN U.S. IS EXPECTED TO EJECT OUT INTO THE NORTHERN PLAINS...BRINGING A COLD FRONT INTO OR THROUGH THE FORECAST AREA SATURDAY NIGHT. ENVISION THE WEEKEND TIMING OF ALL THIS WILL GET ADJUSTED OVER THE COMING DAYS...AND HAVE SOME CONCERN THE MAJORITY OF MODELS INCLUDING THE 01.00Z ECMWF ARE TOO FAST WITH THIS TIMING GIVEN THE DOWNSTREAM RIDGE. THEREFORE...PRECIPITATION CHANCES WITH THE WARM CONVEYOR BELT AHEAD OF THE COLD FRONT ARE HELD TO 20-30 AT THIS TIME. DID NOT INTRODUCE ANY THUNDER BECAUSE THERE APPEARS TO BE LIMITED INSTABILITY AT THIS TIME. TEMPERATURES SHOULD STAY ABOVE NORMAL FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT...UNTIL THE COLD FRONT PASSES. EVEN BEHIND IT...READINGS COULD STAY NEAR OR ABOVE NORMAL. && .AVIATION...THROUGH 06Z MONDAY 1150 PM CDT SAT MAR 31 2012 CHALLENGING CLOUD FORECAST ONCE AGAIN FOR THIS SET OF TAFS. 925MB WINDS HAVE BECOME MORE SOUTHERLY THROUGH THE EVENING HOURS WHICH HAS PUSHED THE LOW STRATUS NORTH OF THE TAF SITES. 01.00Z HRRR DOES SHOW THIS NORTHWARD TREND THROUGHOUT THE NIGHT...BEFORE EXPANDING IT BACK SOUTHWARD BETWEEN 11Z-14Z. THE BIGGEST QUESTION IS WILL THEY MAKE IT BACK IN TO KLSE AND KRST. BOTH THE 01.00Z RUC AND NAM SHOWS THESE LOW LEVEL WINDS TO BECOME MORE EASTERLY BY 12Z WHICH WOULD TEND TO FAVOR THE CLOUDS MOVING BACK SOUTHWARD OR RE-DEVELOPING. FOR THE 06Z TAFS...DID BRING THE STRATUS BACK IN AT BOTH SITES BETWEEN 13Z-19Z...ALONG WITH SOME REDUCED VISIBILITIES. COULD BE SOME IFR CONDITIONS...ESPECIALLY AT KRST. STILL EXPECT THESE TO SCATTERED OUT MIDDAY TO EARLY AFTERNOON SUNDAY AS STRONGER PRESSURE GRADIENT INCREASES THE WINDS. VFR CONDITIONS THEN WILL PERSIST THROUGH 06Z. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 AM CDT SUN APR 1 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS PUEBLO CO
245 AM MDT TUE APR 3 2012 .UPDATE... .SHORT TERM...HAVE PUT OUT A SHORT FUSE HIGH WIND WARNING DUE TO PERSISTENT GUSTS OVER 60 MPH HERE AT KPUB AND AT A FEW SPOTS IN EL PASO AS WELL. WIDESPREAD WINDS OVER 50 MPH STILL BEING OBSERVED. ONGOING PRECIP IS BRINGING SOME HIGHER MOMENTUM AIR TO THE GROUND...AND THIS SHOULD CONTINUE FOR AT LEAST THE NEXT SEVERAL HOURS BEFORE WINDS GRADUALLY QUIET DOWN. WINTER HIGHLIGHTS LOOK ON TRACK FOR MOST PART. NAM IS SHOWING EXTREMELY HEAVY SNOW OVER THE SRN MTS AND ESPECIALLY SPANISH PEAKS REGION. WOULD NOT BE SURPRISED TO SEE SPOTS LIKE CUCHARA GET WELL IN EXCESS OF 2 FEET FROM THIS STORM. ROSE && .PREV DISCUSSION... /ISSUED 1128 PM MDT MON APR 2 2012/ AVIATION... IFR CIGS/VIS EXPECTED TO IMPACT THE TAF SITES FROM TONIGHT INTO TUESDAY...ESPECIALLY AFTER 07Z/3RD AS INTENSE STORM SYSTEM SLOWLY MOVES ACROSS NORTHERN NEW MEXICO. IN ADDITION...GUSTY NORTH WINDS IN THE 25 TO 45 KT RANGE SHOULD CONTINUE AT BOTH KCOS AND KPUB TAFS SITES TONIGHT. IT NOW APPEARS THAT THE HEAVIEST SNOW FOR KCOS AND KPUB SHOULD BE NOTED FROM 07Z-15Z AND THEN POSSIBLY AGAIN FROM 21Z TUESDAY TO 03Z WEDNESDAY. KALS...KCOS AND KPUB COULD ALL EXPERIENCE SOME ACCUMULATING SNOW FROM AFTER MIDNIGHT TONIGHT INTO TUESDAY. PREV DISCUSSION... /ISSUED 857 PM MDT MON APR 2 2012/ UPDATE... WILL ALLOW HIGH WIND WARNING TO EXPIRE AS ONLY AREA EXCEEDING 50 KNOT GUSTS THE PAST 2 HOURS HAS BEEN HERE AT KPUB...WITH WINDS DIMINISHING SLIGHTLY ELSEWHERE. HRRR SUGGESTS SOME 40-45 KNOT GUSTS OVER EASTERN EL PASO AND NORTHERN PUEBLO COUNTIES STILL POSSIBLE THROUGH 05Z...AND PERHAPS SOME BRIEF CONVECTIVE OUTFLOW WINDS TO AROUND 45 KNOTS ACROSS PROWERS AND BACA COUNTIES FROM TSRA IN KS. PRECIP A LITTLE SLOW TO GET GOING THIS EVENING WITH DRY SURFACE LAYER OVER EASTERN COLORADO AND DEEPEST LIFT JUST SOUTH OF THE AREA. WILL NUDGE POPS DOWNWARD MANY AREAS THROUGH 06Z WITH THIS UPDATE..ESPECIALLY KPUB/KCOS. 00Z NAM RAMPS UP PRECIP AFTER 06Z AS DEEPER MOISTURE PUSHES WESTWARD...WITH A PROLONGED PERIOD OF MODERATE/HEAVY RAIN AND SNOW CONTINUING WELL INTO TUES NIGHT. NAM 00Z QPF INDICATES LIQUID AMOUNTS OVER 2 INCHES OVER THE PALMER DIVIDE AND ACROSS THE SOUTHERN SANGRES/WETS AND I-25 CORRIDOR FROM PUEBLO SOUTHWARD...WHICH SUGGESTS FORECASTS OF 1 TO 2 FEET OF SNOW OVER THE HIGHER TERRAIN LOOK ON TRACK. KCOS/KPUB/CANON CITY PRECIP AMOUNTS STILL TRICKY WITH USUAL PRECIP MINIMUM NEARBY...THOUGH STRENGTH OF ISENTROPIC UPGLIDE SHOULD OVERCOME DOWNSLOPE FLOW FOR SEVERAL HOURS LATE TONIGHT INTO TUES. OVERALL TREND OF THE FORECAST LOOKS GOOD. --10 PREV DISCUSSION... /ISSUED 400 PM MDT MON APR 2 2012/ SHORT TERM... (TONIGHT AND TUESDAY) STRONG SPRING STORM TAKING AIM ON SOUTH CENTRAL AND SOUTHEAST COLORADO... MODELS IN REMARKABLE AGREEMENT WITH THE OVERALL DETAILS OF CLOSED UPPER LOW ACROSS EAST CENTRAL NEW MEXICO SHIFTING EASTWARD THEN NORTHEASTWARD INTO THE TX/OK PANHANDLE BY TUES AFTERNOON. FRONT HAS ALREADY SLAMMED THROUGH EASTERN CO EARLIER TODAY...WITH PEAK GUSTS IN EXCESS OF 60 MPH ACROSS PORTIONS OF EL PASO COUNTY. HRRR AND LOCAL 4 KM WRF INDICATED TWO PERIODS OF STRONGER WINDS...ONE THIS MORNING...AND ANOTHER THIS AFTERNOON INTO EARLY THIS EVENING. JUST PICKED UP A GUST TO 50 KTS AT KPUB AIRPORT AROUND 230 PM...SO PERHAPS THE SHORT RANGE MODELS DO HAVE A HANDLE ON THIS. THUS...WILL MAINTAIN HIGH WIND WARNINGS THROUGH 03Z. INTERESTINGLY...HRRR SUGGESTS CORE OF STRONGER WINDS MAY EXPAND ACROSS MORE OF THE SOUTHEAST PLAINS AND CONTINUE THROUGH 06Z...HOWEVER WITH TIGHTEST PRESSURE GRADIENT ALREADY PAST...WILL LEAVE CURRENT EXPIRATION AT 03Z AND LET LATER SHIFTS MONITOR THE TRENDS TO DECIDE IF EXTENSION IN TIME...OR EXPANSION IN AREA IS NECESSARY. LOCAL 4 KM WRF BACKED OFF SOME ON WIND GUSTS AFTER 03Z FOR ALL BUT PERHAPS EASTERN EL PASO COUNTY. OTHER AREA OF CONCERN FOR HIGH WINDS CONTINUES ALONG THE EASTERN SIDE OF THE SAN LUIS VALLEY AS WINDS ACCELERATE THROUGH THE PASSES IN THE SANGRES AND SPILLS INTO THE VALLEY. HRRR AND 12Z 4KM WRF STILL PAINT THIS SCENARIO IN THE LATEST RUNS...WITH PEAK WINDS OCCURRING NOW THROUGH 00Z...WITH GUSTS STARTING TO TAIL OFF BY 03Z. ALS HAD A WIND GUST TO 54 MPH AFTER NOON...WHICH IS VERY CLOSE. SUSPECT LOCAL AREAS TO THE WEST HAD HIGHER GUSTS. AGAIN...WRF KEEPS GUSTS UP AROUND 70 MPH THROUGH 03Z BEFORE TAILING OFF...SO CURRENT HIGHLIGHT LOOKS ON TARGET. FIRST LOBE OF ENERGY WILL ROTATE AROUND THE CLOSED LOW INTO SOUTHEAST COLORADO THIS EVENING. SNOW IS ALREADY OCCURRING ACROSS THE EAST FACING SLOPES OF THE SANGRES/WETS...THOUGH ITS BEEN PRETTY LIGHT SO FAR AS MOISTURE LAYER REMAINS SHALLOW. HOWEVER...RADARS TO THE SOUTH SHOW ECHOES EXPANDING ACROSS NORTHEAST NM WITH SOME EMBEDDED CONVECTION EVIDENT VIA LIGHTNING STRIKES. SHOULD SEE THIS BAND OF SHOWERS SPREAD NORTHWARD THROUGH THE EVENING WITH SNOW SPREADING NORTHWARD AND RAMPING UP ACROSS THE PIKES PEAK AREA AFTER 03-06Z. NICE ISENTROPIC UPGLIDE EVIDENT IN BOTH NAM AND GFS ON THE 300K SFC...AND MODELS IN GOOD AGREEMENT WITH HEAVY QPF AMOUNTS ACROSS A LARGE PORTION OF THE SOUTHEAST PLAINS THROUGH TUESDAY...PARTICULARLY NEAR THE MOUNTAINS. SNOW LEVELS WILL START OFF AROUND 7000 FEET...BUT DROP TO AROUND 5000 FEET OVERNIGHT. TIMING OF THE DROP IN TEMPERATURES AND THE RESIDUAL WARMTH OF THE GROUND WILL PLAY A BIG ROLE IN HOW MUCH SNOW ACCUMULATES ACROSS THE LOWER ELEVATIONS OF THE I-25 CORRIDOR SUCH AS SOUTHERN EL PASO AND PUEBLO COUNTIES. HOWEVER...WITH GOOD MODEL CONSENSUS AND IMPRESSIVE TROWAL ALOFT EXPECTED TO OVERWHELM DOWNSLOPE OFF THE PALMER AT LEAST THROUGH THE 06Z TO 15Z WINDOW...HAVE OPTED TO ISSUE A WINTER WEATHER ADVISORY FOR THE LOWER ELEVATIONS OF THE I-25 CORRIDOR...INCLUDING COLORADO SPRINGS AND PUEBLO. SNOWFALL AMOUNTS WILL LIKELY EXHIBIT A WIDE RANGE WITH SOME MELTING OFF ROAD SURFACES AT TIMES...BUT ANYWHERE FROM 2 INCHES ON THE GRASS...TO AROUND 6 INCHES NEAR THE MOUNTAINS SEEMS PLAUSIBLE. WITH A PERIOD OF EAST TO NORTHEAST WINDS FUNNELING UP THE ARKANSAS RIVER...AND UPSLOPING ALONG THE WEST SIDE OF THE LA GARITAS/AND EASTERN SAN JUANS...WILL INCLUDE THESE AREAS IN A WINTER WEATHER ADVISORY AND RUN IT THROUGH 00Z. BIGGEST WINNER IN THIS EVENT WILL BE THE EAST SLOPES OF THE SANGRES AND WETS 40 TO 50 KTS OF NORTHEAST UPSLOPE WILL RESULT IN 1 TO 2 FEET OF SNOW...WITH HIGHER AMOUNTS ( UP TO 30 INCHES) ACROSS THE HIGHER ELEVATIONS. REMAINDER OF THE HEADLINES IN GOOD SHAPE. TROWAL EVENTUALLY PULLS OFF TO THE NORTHEAST ON TUESDAY WITH SNOW WINDING DOWN FROM SOUTHWEST TO NORTHEAST DURING THE DAY ON TUESDAY. -KT LONG TERM... (TUESDAY NIGHT-MONDAY) TIMING AND LOCATION OF UPPER LEVEL STORM LIFTING OUT ACROSS THE SE PLAINS TUESDAY NIGHT THE MAIN FORECAST PROBLEM... TUESDAY NIGHT-WEDNESDAY...SLIGHT MODEL DIFFERENCES ON TIMING AND LOCATION OF UPPER LOW LIFTING OUT ACROSS THE SE PLAINS CONTINUE AND HAVE TAILORED FORECAST TOWARDS THE NAM AND EC WHICH HAVE THE LOW ACROSS EXTREME NORTHEAST NEW MEXICO AT 00Z WED AND THEN SLOWLY LIFT IT OUT ACROSS WESTERN OKLAHOMA INTO CENTRAL OKLAHOMA THROUGH THE DAY ON WEDNESDAY. ONGOING WRAP AROUND PRECIPITATION ACROSS THE EASTERN MTS AND I-25 CORRIDOR TUESDAY AFTERNOON SLOWLY SHIFTS EAST AND DIMINISHES FROM WEST TO EAST OVERNIGHT...AS UPPER LEVEL FLOW BECOMES MORE NORTHWEST. COULD SEE SOME ADDITIONAL LIGHT ACCUMULATIONS OF A COUPLE OF INCHES ACROSS THE NORTH AND EAST FACING SLOPES OF THE EASTERN MTS AND ALONG WITH PALMER DVD AND RATON MESA TUESDAY EVENING WITH THINGS WINDING INTO WEDNESDAY MORNING. TEMPERATURES ALOFT WARM FROM WEST TO EAST THROUGH THE DAY ON WEDNESDAY...AS UPPER LEVEL RIDGING BUILDS INTO THE STATE WITH HIGHS WARMING BACK TO AT OR SLIGHTLY ABOVE SEASONAL AVERAGES...THOUGH HAVE TAPERED BACK HIGHS A TAD IN EXPECTED SNOW COVERED AREAS. WEDNESDAY NIGHT-MONDAY...WARMER AND DRIER WEATHER CONTINUES TO BE PROGGED THROUGH THE PERIOD...WITH MODERATE TO STRONG WESTERLY FLOW EXPECTED ACROSS THE REGION AS SEVERAL SHORT WAVES MOVE ACROSS THE NORTHERN ROCKIES. ONE WAVE MOVES ACROSS THE REGION THURSDAY NIGHT AND FRIDAY...WITH BREEZY TO WINDY CONDITIONS AND POSSIBLE CRITICAL FIRE WEATHER CONDITIONS ON FRIDAY...DEPENDING ON HOW MUCH PRECIP FALLS. PASSING WAVE SENDS A DRY COLD FRONT ACROSS THE PLAINS FRIDAY WITH SLIGHTLY COOLER TEMPERATURES ACROSS THE AREA ON SATURDAY. ANOTHER WAVE POSSIBLE MOVES ACROSS THE NORTHERN ROCKIES ON SUNDAY NIGHT...WITH A BACKDOOR COLD FRONT POSSIBLE BRINGING IN ENOUGH LOW LEVEL MOISTURE FOR A FEW SHOWERS ACROSS THE EASTERN PLAINS ON MONDAY. HOWEVER...WILL KEEP A DRY FORECAST IN TACT THROUGH THE PERIOD. -MW AVIATION... IFR CIGS/VIS EXPECTED TO AFFECT THE TAF SITES TONIGHT AS STRONG SYSTEM MOVES ACROSS NORTHERN NEW MEXICO. STRONG NORTH WINDS IN THE 30 TO 45 KT RANGE WILL CONTINUE AT KCOS AND KPUB BEFORE DECREASING TOWARDS 06Z. KALS WILL CONTINUE TO SEE EAST WINDS IN THE 25 TO 40 KT RANGE THROUGH EARLY EVENING WITH PERIODS OF BLDU. HEAVIEST SNOW WILL IMPACT KCOS AND KPUB BETWEEN 06Z-18Z PERIOD WITH POTENTIAL FOR A COUPLE INCHES OF SNOW...MAINLY ON GRASSY SURFACES AT KPUB...TO AROUND 2 TO 5 INCHES AT KCOS. WITH WARM GROUND...THERE WILL BE SOME MELTING AT TIMES AT KCOS...BUT PAVED SURFACES COULD BECOME SLUSHY AND SNOWPACKED UNDER THE HEAVIER SNOW BANDS. KALS COULD SEE AN INCH OR TWO AS WELL. RAIN/SNOW SWITCH OVER WILL OCCUR AROUND 03Z FOR KCOS AND KALS...AND AROUND 06Z FOR KPUB. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ072>075- 078>082-084-087-088. WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ058- 060>063-066>068-076-077. HIGH WIND WARNING UNTIL 6 AM MDT WEDNESDAY FOR COZ084>086. WINTER WEATHER ADVISORY UNTIL NOON MDT TODAY FOR COZ083-085-086. && $$ 44/50
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1128 PM MDT MON APR 2 2012 .AVIATION... IFR CIGS/VIS EXPECTED TO IMPACT THE TAF SITES FROM TONIGHT INTO TUESDAY...ESPECIALLY AFTER 07Z/3RD AS INTENSE STORM SYSTEM SLOWLY MOVES ACROSS NORTHERN NEW MEXICO. IN ADDITION...GUSTY NORTH WINDS IN THE 25 TO 45 KT RANGE SHOULD CONTINUE AT BOTH KCOS AND KPUB TAFS SITES TONIGHT. IT NOW APPEARS THAT THE HEAVIEST SNOW FOR KCOS AND KPUB SHOULD BE NOTED FROM 07Z-15Z AND THEN POSSIBLY AGAIN FROM 21Z TUESDAY TO 03Z WEDNESDAY. KALS...KCOS AND KPUB COULD ALL EXPERIENCE SOME ACCUMULATING SNOW FROM AFTER MIDNIGHT TONIGHT INTO TUESDAY. && .PREV DISCUSSION... /ISSUED 857 PM MDT MON APR 2 2012/ UPDATE... WILL ALLOW HIGH WIND WARNING TO EXPIRE AS ONLY AREA EXCEEDING 50 KNOT GUSTS THE PAST 2 HOURS HAS BEEN HERE AT KPUB...WITH WINDS DIMINISHING SLIGHTLY ELSEWHERE. HRRR SUGGESTS SOME 40-45 KNOT GUSTS OVER EASTERN EL PASO AND NORTHERN PUEBLO COUNTIES STILL POSSIBLE THROUGH 05Z...AND PERHAPS SOME BRIEF CONVECTIVE OUTFLOW WINDS TO AROUND 45 KNOTS ACROSS PROWERS AND BACA COUNTIES FROM TSRA IN KS. PRECIP A LITTLE SLOW TO GET GOING THIS EVENING WITH DRY SURFACE LAYER OVER EASTERN COLORADO AND DEEPEST LIFT JUST SOUTH OF THE AREA. WILL NUDGE POPS DOWNWARD MANY AREAS THROUGH 06Z WITH THIS UPDATE..ESPECIALLY KPUB/KCOS. 00Z NAM RAMPS UP PRECIP AFTER 06Z AS DEEPER MOISTURE PUSHES WESTWARD...WITH A PROLONGED PERIOD OF MODERATE/HEAVY RAIN AND SNOW CONTINUING WELL INTO TUES NIGHT. NAM 00Z QPF INDICATES LIQUID AMOUNTS OVER 2 INCHES OVER THE PALMER DIVIDE AND ACROSS THE SOUTHERN SANGRES/WETS AND I-25 CORRIDOR FROM PUEBLO SOUTHWARD...WHICH SUGGESTS FORECASTS OF 1 TO 2 FEET OF SNOW OVER THE HIGHER TERRAIN LOOK ON TRACK. KCOS/KPUB/CANON CITY PRECIP AMOUNTS STILL TRICKY WITH USUAL PRECIP MINIMUM NEARBY...THOUGH STRENGTH OF ISENTROPIC UPGLIDE SHOULD OVERCOME DOWNSLOPE FLOW FOR SEVERAL HOURS LATE TONIGHT INTO TUES. OVERALL TREND OF THE FORECAST LOOKS GOOD. --10 PREV DISCUSSION... /ISSUED 400 PM MDT MON APR 2 2012/ SHORT TERM... (TONIGHT AND TUESDAY) .STRONG SPRING STORM TAKING AIM ON SOUTH CENTRAL AND SOUTHEAST COLORADO... MODELS IN REMARKABLE AGREEMENT WITH THE OVERALL DETAILS OF CLOSED UPPER LOW ACROSS EAST CENTRAL NEW MEXICO SHIFTING EASTWARD THEN NORTHEASTWARD INTO THE TX/OK PANHANDLE BY TUES AFTERNOON. FRONT HAS ALREADY SLAMMED THROUGH EASTERN CO EARLIER TODAY...WITH PEAK GUSTS IN EXCESS OF 60 MPH ACROSS PORTIONS OF EL PASO COUNTY. HRRR AND LOCAL 4 KM WRF INDICATED TWO PERIODS OF STRONGER WINDS...ONE THIS MORNING...AND ANOTHER THIS AFTERNOON INTO EARLY THIS EVENING. JUST PICKED UP A GUST TO 50 KTS AT KPUB AIRPORT AROUND 230 PM...SO PERHAPS THE SHORT RANGE MODELS DO HAVE A HANDLE ON THIS. THUS...WILL MAINTAIN HIGH WIND WARNINGS THROUGH 03Z. INTERESTINGLY...HRRR SUGGESTS CORE OF STRONGER WINDS MAY EXPAND ACROSS MORE OF THE SOUTHEAST PLAINS AND CONTINUE THROUGH 06Z...HOWEVER WITH TIGHTEST PRESSURE GRADIENT ALREADY PAST...WILL LEAVE CURRENT EXPIRATION AT 03Z AND LET LATER SHIFTS MONITOR THE TRENDS TO DECIDE IF EXTENSION IN TIME...OR EXPANSION IN AREA IS NECESSARY. LOCAL 4 KM WRF BACKED OFF SOME ON WIND GUSTS AFTER 03Z FOR ALL BUT PERHAPS EASTERN EL PASO COUNTY. OTHER AREA OF CONCERN FOR HIGH WINDS CONTINUES ALONG THE EASTERN SIDE OF THE SAN LUIS VALLEY AS WINDS ACCELERATE THROUGH THE PASSES IN THE SANGRES AND SPILLS INTO THE VALLEY. HRRR AND 12Z 4KM WRF STILL PAINT THIS SCENARIO IN THE LATEST RUNS...WITH PEAK WINDS OCCURRING NOW THROUGH 00Z...WITH GUSTS STARTING TO TAIL OFF BY 03Z. ALS HAD A WIND GUST TO 54 MPH AFTER NOON...WHICH IS VERY CLOSE. SUSPECT LOCAL AREAS TO THE WEST HAD HIGHER GUSTS. AGAIN...WRF KEEPS GUSTS UP AROUND 70 MPH THROUGH 03Z BEFORE TAILING OFF...SO CURRENT HIGHLIGHT LOOKS ON TARGET. FIRST LOBE OF ENERGY WILL ROTATE AROUND THE CLOSED LOW INTO SOUTHEAST COLORADO THIS EVENING. SNOW IS ALREADY OCCURRING ACROSS THE EAST FACING SLOPES OF THE SANGRES/WETS...THOUGH ITS BEEN PRETTY LIGHT SO FAR AS MOISTURE LAYER REMAINS SHALLOW. HOWEVER...RADARS TO THE SOUTH SHOW ECHOES EXPANDING ACROSS NORTHEAST NM WITH SOME EMBEDDED CONVECTION EVIDENT VIA LIGHTNING STRIKES. SHOULD SEE THIS BAND OF SHOWERS SPREAD NORTHWARD THROUGH THE EVENING WITH SNOW SPREADING NORTHWARD AND RAMPING UP ACROSS THE PIKES PEAK AREA AFTER 03-06Z. NICE ISENTROPIC UPGLIDE EVIDENT IN BOTH NAM AND GFS ON THE 300K SFC...AND MODELS IN GOOD AGREEMENT WITH HEAVY QPF AMOUNTS ACROSS A LARGE PORTION OF THE SOUTHEAST PLAINS THROUGH TUESDAY...PARTICULARLY NEAR THE MOUNTAINS. SNOW LEVELS WILL START OFF AROUND 7000 FEET...BUT DROP TO AROUND 5000 FEET OVERNIGHT. TIMING OF THE DROP IN TEMPERATURES AND THE RESIDUAL WARMTH OF THE GROUND WILL PLAY A BIG ROLE IN HOW MUCH SNOW ACCUMULATES ACROSS THE LOWER ELEVATIONS OF THE I-25 CORRIDOR SUCH AS SOUTHERN EL PASO AND PUEBLO COUNTIES. HOWEVER...WITH GOOD MODEL CONSENSUS AND IMPRESSIVE TROWAL ALOFT EXPECTED TO OVERWHELM DOWNSLOPE OFF THE PALMER AT LEAST THROUGH THE 06Z TO 15Z WINDOW...HAVE OPTED TO ISSUE A WINTER WEATHER ADVISORY FOR THE LOWER ELEVATIONS OF THE I-25 CORRIDOR...INCLUDING COLORADO SPRINGS AND PUEBLO. SNOWFALL AMOUNTS WILL LIKELY EXHIBIT A WIDE RANGE WITH SOME MELTING OFF ROAD SURFACES AT TIMES...BUT ANYWHERE FROM 2 INCHES ON THE GRASS...TO AROUND 6 INCHES NEAR THE MOUNTAINS SEEMS PLAUSIBLE. WITH A PERIOD OF EAST TO NORTHEAST WINDS FUNNELING UP THE ARKANSAS RIVER...AND UPSLOPING ALONG THE WEST SIDE OF THE LA GARITAS/AND EASTERN SAN JUANS...WILL INCLUDE THESE AREAS IN A WINTER WEATHER ADVISORY AND RUN IT THROUGH 00Z. BIGGEST WINNER IN THIS EVENT WILL BE THE EAST SLOPES OF THE SANGRES AND WETS 40 TO 50 KTS OF NORTHEAST UPSLOPE WILL RESULT IN 1 TO 2 FEET OF SNOW...WITH HIGHER AMOUNTS ( UP TO 30 INCHES) ACROSS THE HIGHER ELEVATIONS. REMAINDER OF THE HEADLINES IN GOOD SHAPE. TROWAL EVENTUALLY PULLS OFF TO THE NORTHEAST ON TUESDAY WITH SNOW WINDING DOWN FROM SOUTHWEST TO NORTHEAST DURING THE DAY ON TUESDAY. -KT LONG TERM... (TUESDAY NIGHT-MONDAY) .TIMING AND LOCATION OF UPPER LEVEL STORM LIFTING OUT ACROSS THE SE PLAINS TUESDAY NIGHT THE MAIN FORECAST PROBLEM... TUESDAY NIGHT-WEDNESDAY...SLIGHT MODEL DIFFERENCES ON TIMING AND LOCATION OF UPPER LOW LIFTING OUT ACROSS THE SE PLAINS CONTINUE AND HAVE TAILORED FORECAST TOWARDS THE NAM AND EC WHICH HAVE THE LOW ACROSS EXTREME NORTHEAST NEW MEXICO AT 00Z WED AND THEN SLOWLY LIFT IT OUT ACROSS WESTERN OKLAHOMA INTO CENTRAL OKLAHOMA THROUGH THE DAY ON WEDNESDAY. ONGOING WRAP AROUND PRECIPITATION ACROSS THE EASTERN MTS AND I-25 CORRIDOR TUESDAY AFTERNOON SLOWLY SHIFTS EAST AND DIMINISHES FROM WEST TO EAST OVERNIGHT...AS UPPER LEVEL FLOW BECOMES MORE NORTHWEST. COULD SEE SOME ADDITIONAL LIGHT ACCUMULATIONS OF A COUPLE OF INCHES ACROSS THE NORTH AND EAST FACING SLOPES OF THE EASTERN MTS AND ALONG WITH PALMER DVD AND RATON MESA TUESDAY EVENING WITH THINGS WINDING INTO WEDNESDAY MORNING. TEMPERATURES ALOFT WARM FROM WEST TO EAST THROUGH THE DAY ON WEDNESDAY...AS UPPER LEVEL RIDGING BUILDS INTO THE STATE WITH HIGHS WARMING BACK TO AT OR SLIGHTLY ABOVE SEASONAL AVERAGES...THOUGH HAVE TAPERED BACK HIGHS A TAD IN EXPECTED SNOW COVERED AREAS. WEDNESDAY NIGHT-MONDAY...WARMER AND DRIER WEATHER CONTINUES TO BE PROGGED THROUGH THE PERIOD...WITH MODERATE TO STRONG WESTERLY FLOW EXPECTED ACROSS THE REGION AS SEVERAL SHORT WAVES MOVE ACROSS THE NORTHERN ROCKIES. ONE WAVE MOVES ACROSS THE REGION THURSDAY NIGHT AND FRIDAY...WITH BREEZY TO WINDY CONDITIONS AND POSSIBLE CRITICAL FIRE WEATHER CONDITIONS ON FRIDAY...DEPENDING ON HOW MUCH PRECIP FALLS. PASSING WAVE SENDS A DRY COLD FRONT ACROSS THE PLAINS FRIDAY WITH SLIGHTLY COOLER TEMPERATURES ACROSS THE AREA ON SATURDAY. ANOTHER WAVE POSSIBLE MOVES ACROSS THE NORTHERN ROCKIES ON SUNDAY NIGHT...WITH A BACKDOOR COLD FRONT POSSIBLE BRINGING IN ENOUGH LOW LEVEL MOISTURE FOR A FEW SHOWERS ACROSS THE EASTERN PLAINS ON MONDAY. HOWEVER...WILL KEEP A DRY FORECAST IN TACT THROUGH THE PERIOD. -MW AVIATION... IFR CIGS/VIS EXPECTED TO AFFECT THE TAF SITES TONIGHT AS STRONG SYSTEM MOVES ACROSS NORTHERN NEW MEXICO. STRONG NORTH WINDS IN THE 30 TO 45 KT RANGE WILL CONTINUE AT KCOS AND KPUB BEFORE DECREASING TOWARDS 06Z. KALS WILL CONTINUE TO SEE EAST WINDS IN THE 25 TO 40 KT RANGE THROUGH EARLY EVENING WITH PERIODS OF BLDU. HEAVIEST SNOW WILL IMPACT KCOS AND KPUB BETWEEN 06Z-18Z PERIOD WITH POTENTIAL FOR A COUPLE INCHES OF SNOW...MAINLY ON GRASSY SURFACES AT KPUB...TO AROUND 2 TO 5 INCHES AT KCOS. WITH WARM GROUND...THERE WILL BE SOME MELTING AT TIMES AT KCOS...BUT PAVED SURFACES COULD BECOME SLUSHY AND SNOWPACKED UNDER THE HEAVIER SNOW BANDS. KALS COULD SEE AN INCH OR TWO AS WELL. RAIN/SNOW SWITCH OVER WILL OCCUR AROUND 03Z FOR KCOS AND KALS...AND AROUND 06Z FOR KPUB. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075- 078>082-084-087-088. WINTER WEATHER ADVISORY UNTIL 6 PM MDT TUESDAY FOR COZ058- 060>063-066>068-076-077. WINTER WEATHER ADVISORY UNTIL NOON MDT TUESDAY FOR COZ083-085- 086. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
119 AM EDT TUE APR 3 2012 .PREV DISCUSSION... /ISSUED 745 PM EDT MON APR 2 2012/ .AVIATION.../06Z TAFS/ STLT/OBS SHOWING LOW/MID CLOUDS FORMING OVER THE WRN GRTLKS REGION IN RESPONSE TO STRONG LOW LEVEL WAA PER LOCAL PROFILERS/WVP. MODELS CONT TO SUGGEST ELEVATED CONVECTION WILL DEVELOP IN THIS AREA 09-12Z AND SHIFT EAST OF THE AREA BY 15Z. COVERAGE AND EXACT LOCATION STILL UNCERTAIN SO ONLY CARRIED VCTS IN TERMINALS DURING THE EARLY MORNING HOURS. REMAINDER OF THE DAY SHOULD HAVE VFR CONDITIONS WITH JUST SCT CU. SLIGHT CHC OF TS DVLPG ALONG A CDFNT DROPPING SOUTH ACROSS THE AREA THIS AFTN/EVE BUT WITH CAPPING INVERSION IN PLACE AND WK FORCING TS CHANCES AT TERMINALS TOO LOW TO MENTION ATTM. CDFNT EXPECTED TO MOVE THROUGH SBN AROUND 21Z AND FWA BY 00Z SHIFTING WINDS FROM SW TO NORTH FOLLOWED BY PERIOD OF LOW VFR STRATO CU CIGS. && .PREV DISCUSSION... SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT CHANCES OF MORE THUNDERSTORMS LATE TONIGHT THROUGH TUESDAY EVENING AND WARMER TEMPERATURES FOR TUESDAY WILL BE THE MAIN SHORT TERM CONCERNS. FOR TONIGHT...MOSTLY CLEAR SKIES EXPECTED ACROSS MUCH OF THE AREA THIS EVENING WITH SOME INCREASING IN MID LEVEL CLOUDINESS WITH MID LEVEL FRONTAL ZONE EXTENDING FROM NORTHERN LOWER MICHIGAN INTO NORTHWEST OHIO. SOME LOWER BASED CLOUDS HAVE ALSO BEEN DEVELOPING ALONG A LINE FROM NORTHWEST ILLINOIS INTO WEST CENTRAL ILLINOIS WHICH SEEM TO CORRELATE WELL WITH RUC 900/850 HPA LAYER FRONTOGENESIS FIELDS THIS AFTERNOON. THIS AXIS WILL GRADUALLY SHIFT EASTWARD LATER THIS EVENING WITH INCREASE IN CLOUDINESS LATER THIS EVENING FROM WEST TO EAST. WATER VAPOR IMAGERY NOT DEPICTING ANY IMMEDIATE SHORT WAVES OF CONSEQUENCE FOR THE LOCAL AREA TONIGHT BUT CONSISTENT SIGNAL OVER THE PAST FEW DAYS HAS BEEN FOR DEVELOPMENT OF 30 KNOT SOUTHWESTERLY LOW LEVEL JET NOSING INTO FAR NORTH CENTRAL INDIANA/SOUTHERN LOWER MICHIGAN...PERHAPS A BIT MORE DELAYED IN THE LAST FEW MODEL CYCLES. SEE LITTLE TO DEVIATE FROM PREVIOUS FORECAST FOR TONIGHT AT THIS POINT WITH MID CHANCE POPS NORTH AND LOW CHANCE POPS SOUTH...WITH THE HIGHER TSRA POPS LINING UP BETTER WITH 850 HPA MOISTURE CONVERGENCE ACROSS SOUTHERN LOWER MICHIGAN AND FAR NORTHERN INDIANA AFTER 06Z AS STRONG LOW LEVEL THETAE ADVECTION SPREADS FROM WEST TO EAST. ELEVATED MIXED LAYER ADVECTING INTO THE AREA LATER TONIGHT DOES POSE SOME UNCERTAINTY WITH MAGNITUDE OF ELEVATED INSTABILITY. TAKING A 900 HPA BASED PARCEL FROM 12Z NAM BUFFER SOUNDINGS YIELDS BETWEEN 1000-1500 J/KG OF ELEVATED CAPE AFTER 06Z. 12Z GFS BUFFER SOUNDINGS REMAIN A BIT MORE PRONOUNCED WITH THIS ELEVATED MIXED LAYER AND MID LEVEL WARM LAYER THAT WOULD RESULT IN LESSER INSTABILITY THAN INDICATED BY THE NAM. EFFECTIVE SHEAR FOR THESE ELEVATED PARCELS SHOULD DECREASE STEADILY OVERNIGHT HOWEVER WHICH SHOULD TEND TO LIMIT POTENTIAL FOR CONVECTIVE ORGANIZATION/SEVERE THREAT. PREVIOUS FORECAST IDEA OF ISOLATED LARGE HAIL THREAT STILL SEEMS IN ORDER...BUT SHIFTED A BIT LATER AFTER 06Z BASED ON TREND OF SLIGHTLY SLOWER MODEL DEPICTION OF LOW LEVEL JET AXIS SHIFTING INTO THE AREA. LINGERING ELEVATED CONVECTION SHOULD DIMINISH EARLY TUESDAY AS LOW LEVEL JET VEERS AND MOISTURE CONVERGENCE WEAKENS. A CONVECTIVELY ENHANCED VORT MAX ACROSS EASTERN TEXAS THIS AFTERNOON SHOULD LIFT NORTHWARD INTO MID MS RVR VALLEY LATE TUESDAY AFTERNOON...BUT OVERALL CONVECTIVE THREAT APPEARS TO BE LOW FOR LATE MORNING/AFTERNOON HOURS WITH FCST SOUNDINGS SUGGEST SOME CAPPING CONCERNS. THUS...HAVE LOWERED AFTERNOON TSRA POPS AND MAINTAINED HIGHEST CHANCE ACROSS THE WEST WHERE FORCING FROM THIS VORT MAX WILL LIKELY BE MAXIMIZED. BEST CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE FOR THE EVENING HOURS AS ANOTHER SOUTHERN CANADIAN UPPER LEVEL SHORT WAVE PROVIDES IMPETUS FOR SFC LOW/FRONT TO SHIFT SOUTHEAST THROUGH THE AREA. LOW LEVEL FRONTOGENESIS ALSO TO STRENGTHEN AS STRONGER NORTHERLY FLOW INTERACTS WITH THIS BOUNDARY DURING THE EARLY EVENING. SEVERE POTENTIAL APPEARS TO BE RELATIVELY LOW AT THIS TIME DUE TO CONTINUED MARGINAL TO WEAK SHEAR PROFILES. HAVE ALSO INCREASED MAX TEMPS FOR TUESDAY WITH CONFIDENCE INCREASING THAT MOST IF NOT ALL OF FORECAST AREA WILL GET INTO WARM SECTOR AGAIN BEFORE FRONTAL PASSAGE IN THE FAR NORTHWEST MID TO LATE AFTERNOON. RECORD HIGHS IN THE UPPER 70S FOR FORT WAYNE AND SOUTH BEND COULD ONCE AGAIN BE AT RISK OF BEING BROKEN. LONG TERM... WEDNESDAY THROUGH MONDAY MAIN FOCUS OF LONG TERM PERIOD IS COOLER TEMPERATURES AND FROST POTENTIAL WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. LONG TERM PERIOD BEGINS WEDNESDAY WITH SURFACE HIGH PRESSURE CENTERED NORTHWEST OF THE REGION BUILDING SOUTHEASTWARD INTO THE LOWER GREAT LAKES...AND A FRONTAL BOUNDARY SITUATED ALONG THE OHIO RIVER VALLEY. CUTOFF UPPER LOW OVER PANHANDLE REGION WILL SLOWLY TRACK EASTWARD TOWARDS MID MISSISSIPPI VALLEY. DRY CONDITIONS ARE EXPECTED WEDNESDAY AND WEDNESDAY NIGHT. KEPT PATCHY FROST MENTION IN THE NE PORTION OF THE FA...BUT INCREASED GRADIENT OF LOW TEMPS FROM NE TO SW AS CUTOFF LOW AND AFOREMENTIONED BOUNDARY PASS JUST SOUTH OF THE FA. CUTOFF LOW WILL CONTINUE EASTWARD INTO LOWER OHIO VALLEY ON THURSDAY. 12Z GFS INDICATED PRECIP POTENTIAL ACROSS THE FAR SW PORTIONS OF THE FA AS FRONTAL BOUNDARY SLIDES EASTWARD. HOWEVER...CONFIDENCE IS LOW AS 12Z GFS RUN OPENS LOW INTO POSITIVELY TILTED WAVE QUICKER AND DIVES MORE SOUTHEASTERLY THAN PREVIOUS RUN...MORE IN LINE WITH 00Z ECMWF. THURSDAY NIGHT LOOKS TO BE THE COOLEST NIGHT IN THE EXTENDED PERIOD AS SFC RIDGE AXIS SLIDES OVERHEAD. KEPT THE AREAS OF FROST MENTION IN ROUGHLY THE SAME AREAS AS PREVIOUS FCST. WILL CONTINUE TO MONITOR THIS PD OVER THE NEXT FEW FORECASTS WITH POSSIBLE NEED FOR HEADLINES...WITH LOWS NEARING 32-33 ACROSS MUCH OF THE FA. SFC RIDGE WILL CONTINUE TO SLIDE EAST ACROSS GREAT LAKES AS UPPER RIDGE AXIS MOVES ACROSS THE REGION. FRIDAY WILL AGAIN BE COOLER WITH EASTERLY WINDS AND SLOWLY MODERATING AIRMASS. KEPT PATCHY FROST MENTION IN FCST FRI NIGHT AS RIDGE AXIS WILL BE JUST EAST OF FA AND LIGHTER WINDS. SATURDAY WILL BE CONSIDERABLY WARM WITH UPPER RIDGE OVER THE AREA AND SFC HIGH EAST...RESULTING IN SOUTHERLY WINDS AND WAA. RAISED TEMPS A FEW DEGREES FROM PREVIOUS FCST/ALLBLEND. NEXT PRECIP CHANCES RETURN SAT NIGHT/SUN AS DEEPENING SFC LOW/EJECTING WRN CONUS TROF ENERGY ACROSS NRN TIER BRINGS A COLD FRONT THROUGH THE REGION. KEPT POPS CHANCE/SLIGHT CHANCE AS BEST FORCING REMAINS NORTH AND BEST MOISTURE/INSTABILITY REMAINS SOUTH. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MARSILI LONG TERM...NG AVIATION...JT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
140 AM MDT TUE APR 3 2012 .UPDATE... ISSUED AT 139 AM MDT TUE APR 3 2012 JUST COMPLETED A QUICK UPDATE. GETTING REPORTS OF SNOW...UP TO AN INCH...A LITTLE FARTHER EAST THAT WAS CURRENTLY CALLED FOR THROUGH THE REST OF THIS EARLY MORNING. SO JUST EXPANDED THAT AREA. UPDATE ISSUED AT 928 PM MDT MON APR 2 2012 AT 0330Z RAIN CONTINUES TO MOVE NORTHWEST AROUND 25 MPH IN RESPONSE TO LOW PRESSURE SPINNING ACROSS EAST CENTRAL NEW MEXICO. NORTH TO NORTHEAST WINDS CONTINUE TO GUST AROUND 40 MPH. FOR TONIGHT ALLOWED WIND ADVISORY TO EXPIRE. WIND GUSTS IN EXCESS OF 45 MPH ARE NO LONGER EXPECTED. FORECAST CHALLENGE FOR THE NEXT 20 HOUR OR SO IS PLACEMENT OF THE HIGHEST POPS/QPF AND SNOW. GENERALLY THINKING IS FOR CURRENT BAND OF PRECIPITATION TO MOVE NORTHWEST THROUGH THE FORECAST AREA DURING THE REMAINDER OF THE NIGHT WITH SOME DRIER MID LEVEL AIR CURRENTLY OVER THE TEXAS PANHANDLE TO QUICKLY MOVE NORTH BRINGING AN END TO THE HEAVIER PRECIPITATION (EXCEPT THE NORTHWEST 1/4 OF THE AREA) BY SUNRISE. FLAGLER CURRENT TEMP IS 37...NAM AND TO A LESSER EXTENT RUC LOWER TEMPERATURES INTO THE LOWER 30S BY SUNRISE WHICH WOULD SUPPORT SNOW VS ANY MIX OF RAIN AND SNOW. HOW FAR EAST THESE COLDER TEMPERATURES GET IS THE BIG QUESTION AS THE NAM PUSHES THEM AS FAR EAST AS THE CO/KS BORDER WHILE THE HRRR IS SLIGHTLY FURTHER WEST AND THE SREF FURTHER WEST TOWARD SEIBERT. RIGHT NOW ONLY HAVE SNOW ACCUMULATIONS OF A FEW INCHES CONFINED TO THE FLAGLER AREA AND MIDNIGHT SHIFT WILL NEED TO MONITOR JUST HOW FAR EAST THE COLDER TEMPERATURES GET. GIVEN THE EXPECTED PRECIPITATION SEVERAL INCHES OF ACCUMULATION IS CERTAINLY POSSIBLE. HAVE UPDATED HWO TO MENTION THE ACCUMULATION POSSIBILITIES. FOR TUESDAY LOWERED TEMPERATURES ACROSS THE ENTIRE AREA AS WE WILL BE UNDER EXTENSIVE CLOUD COVER. 00Z NAM/21Z SREF/00Z MET AND 18Z MAV 3 HOUR TEMPERATURES ALL IN PRETTY GOOD AGREEMENT WITH HIGHS RANGING FROM THE MID 30S TO LOW 40S ACROSS FAR EASTERN COLORADO TO THE MID 40S AND LOW 50S EAST OF THE BORDER. SHOULD HAVE ANOTHER BATCH OF RAIN MOVING IN FROM THE SOUTH DURING THE DAY WITH HIGHEST AMOUNTS GENERALLY SOUTH OF A LINE FROM YUMA TO COLBY AND GOVE. UPDATE ISSUED AT 541 PM MDT MON APR 2 2012 LINE OF SHOWERS AND THUNDERSTORMS JUST EAST-SOUTHEAST OF THE FORECAST AREA MOVING NORTHWEST AT 20-25 MPH. THIS WILL PUT THEM INTO THE SOUTHEAST PORTION OF THE AREA BY 01Z IF NOT A LITTLE SOONER. ALTHOUGH INSTABILITY REMAINS HIGHER TO THE SOUTHEAST OF OUR AREA CANT RULE OUT A FEW LIGHTNING STRIKES SO UPDATED TO INCLUDE SOME THUNDER MENTION. OTHER CHANGES WERE TO BEEF UP THE CLOUDINESS TONIGHT THROUGH TUESDAY AS LOW LEVEL MOISTURE AND CLOUDS COVER THE FORECAST AREA. OTHER CHANGES TO BE MADE LATER AS 00Z MODEL DATA COMES IN. && .SHORT TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 221 PM MDT MON APR 2 2012 PLAN TO LET THE WIND ADVISORY GO TO EXPIRATION AT 03Z. THIS SHOULD WORK OUT WELL SINCE HAVE ALREADY STARTED TO DECREASE. THE NAM MIXED LAYER WINDS INDICATE THAT THEY FALL AT OR JUST BELOW WIND ADVISORY LEVELS AT 03Z. THE GFS MIXED LAYER WIND KEEPS IT WINDY OVER THE SOUTHWEST THROUGH THE NIGHT. THIS IS PROBABLY AN OUTLIER SINCE THE TREND FOR WINDS IN THAT PART OF THE AREA IS SIMILAR TO THE REST OF THE FA. THE EVENING SHIFT WILL NEED TO DETERMINE WHETHER THE ADVISORY SHOULD BE EXTENDED IN TIME. THE UPPER LOW WILL MOVE NORTHEAST TONIGHT. THERE IS SOME UNCERTAINTY AS TO HOW QUICKLY PRECIPITATION WILL MOVE NORTHWARD SINCE THE MODELS DO NOT HAVE THE LOW AS FAR SOUTH AS ITS ACTUAL POSITION ON WATER VAPOR IMAGERY. NEVERTHELESS HAVE INTRODUCED CHANCE POPS FOR THE SOUTHERN ZONES THIS EVENING. BETTER CHANCES SHOULD TAKE PLACE AFTER MIDNIGHT TONIGHT AS THE LOW HAS MORE TIME TO MOVE NORTH. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL GET COLD ENOUGH FOR A FEW HOURS AROUND SUNRISE IN EASTERN COLORADO FOR A MIX OF RAIN/SNOW. THE NAM SHOWS A LULL IN THE PRECIPITATION TUESDAY MORNING WITH THE PASSAGE OF THE INITIAL SHORTWAVE SO WILL KEEP CHANCE POPS IN PLACE FOR TUESDAY MORNING. BY AFTERNOON THE NEXT WAVE IS PROGGED TO MOVE THROUGH THE FA SO WILL INCREASE TO HIGH CHANCE. LOW TEMPERATURES TONIGHT WILL GET DOWN TO 32 IN FAR WESTERN PORTIONS OF THE FA. OTHERWISE TEMPERATURES WILL RANGE FROM THE MID 30S FROM NEAR THE COLORADO BORDER TO THE LOWER 40S IN MCK AND HLC. MAX TEMPERATURES WILL RANGE FROM THE UPPER 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 221 PM MDT MON APR 2 2012 MAIN FOCUS WILL CONTINUE TO BE THE CLOSED LOW AND PRECIP. CHANCES THROUGH WEDNESDAY. MODELS ARE IN BETTER AGREEMENT WITH THE TRACK OF THE CLOSED LOW AS IT MOVES NORTHEAST. NOTICED THE 0Z ECMWF AND LATEST NAM/SREF ARE IN BETTER AGREEMENT THAN YESTERDAY. AS MENTIONED ABOVE...AM CONCERNED THE MODELS DID NOT INITIALIZE THE CLOSED LOW FAR ENOUGH SOUTH BASED MORNING WATER VAPOR IMAGERY. WITH THE CLOSED LOW BEING FURTHER SOUTH THAN WHAT THE MODELS HAVE...AM THINKING IT WILL LIFT FURTHER EAST THAN WHAT THE NAM/SREF/ECMWF HAVE. AS SUCH WILL TRENDED HIGHER POPS FURTHER EAST FOR TUESDAY NIGHT THROUGH WEDNESDAY BASED ON ABOVE CONCERNS. TUESDAY NIGHT THE LEFT EXIT OF THE UPPER LEVEL JET MOVES OVER THE EASTERN PART OF THE AREA AND ISENTROPIC LIFT INCREASES AS THE CLOSED LOW APPROACHES. OVER THE NORTHERN HALF OF THE AREA DEEP LIFTING SETS UP AND A BAND OF FRONTOGENESIS DEVELOPS. AS THE CLOSED LOW MOVES EAST THROUGH THE NIGHT THE LIFT FOLLOWS. TRENDED POPS IN THE SAME DIRECTION...WITH THE BEST CHANCES GENERALLY OVER THE EASTERN PART OF THE AREA WHERE THE BEST LIFT AND HIGHEST CERTAINTY WILL BE WITH LOWER CHANCES TO THE WEST WHERE THE I AM MORE UNCERTAIN THAT THE LIFT WILL DEVELOP BE AS THE SYSTEM MOVES EAST. AREAS OF EASTERN COLORADO MAY SEE A MIX OF RAIN AND SNOW AS TEMPERATURES DIP TO THE FREEZING POINT. NAM POINT SOUNDINGS SUGGEST A WINDOW OF FREEZING DRIZZLE DURING THE OVERNIGHT AND EARLY MORNING HOURS. HOWEVER SREF PRECIP. TYPE FIELDS ONLY SHOW A MIX OF RAIN AND SNOW. WILL JUST MENTION THE RAIN/SNOW MIX THROUGH THE NIGHT AND EARLY MORNING HOURS DUE TO UNCERTAINTY OF THE TRACK OF THE STORM SYSTEM. WEDNESDAY ISENTROPIC LIFT DWINDLES TOWARD THE WEST AS THE CLOSED LOW DEPARTS. HAVE PRECIP. CHANCES HIGHEST IN THE EAST WHERE THE FORCING FOR LIFT IS BEST WITH CHANCES DECLINING TO THE WEST. THROUGH THE DAY PRECIP. CHANCES DECLINE ACROSS THE AREA AS THE CLOSED LOW MOVES FURTHER EAST...WITH THE PRECIP. CHANCES COMING TO AN END OVER THE FAR EAST BY EARLY EVENING. FOR THURSDAY THROUGH MONDAY AN UPPER LEVEL SHORT WAVE RIDGE MOVES OVER THE AREA THURSDAY BEHIND THE EXITING STORM SYSTEM. BY THURSDAY NIGHT THE UPPER LEVEL FLOW TURNS TO THE NORTHWEST AHEAD OF THE NEXT UPPER LEVEL TROUGH MOVING ACROSS THE INTER MOUNTAIN WEST. PRECIPITATION CHANCES RETURN TO THE EASTERN PART OF THE AREA THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A COUPLE UPPER LEVEL SHORT WAVE TROUGHS MOVE OVER THE AREA. WITH THE LOW LEVEL JET AND ISENTROPIC LIFT AHEAD OF THE TROUGHS...A FEW SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE OVER THE EASTERN PART OF THE AREA. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD...WITH A WARMING TREND THURSDAY AND FRIDAY. COOLER BUT ABOVE NORMAL TEMPERATURES RETURN THROUGH THE REST OF THE PERIOD BEHIND A COLD FRONT THAT MOVES THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1032 PM MDT MON APR 2 2012 RUC IS HANDLING THE CLOUDS FAIRLY WELL SO HAVE USED THIS MODEL AS WELL AS THE HRRR CONCERNING THE PRECIPITATION. MVFR CIGS AT BOTH KGLD AND KMCK TO CONTINUE THROUGH THE NEXT 24 HOURS. BAND OF PRECIPITATION WILL IMPACT BOTH TERMINALS AT THE BEGINNING OF THE TAF PERIOD AND CONTINUE THROUGH 10Z-11Z BEFORE ROTATING OUT OF THE AREA AS MID LEVEL DRY SLOT MOVES IN. THERE IS A CHANCE FOR SEVERAL HOURS OF IFR CONDITIONS AT BOTH TERMINALS TIL 16Z OR SO WHEN ANOTHER BATCH OF PRECIP MOVES NORTH IMPACTING KGLD AROUND 16Z AND KMCK AROUND 00Z. THIS BATCH OF PRECIP SHOULD CONTINUE THROUGH THE REMAINDER OF THE TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...FS LONG TERM....JTL AVIATION...BAS/DDT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1040 PM MDT MON APR 2 2012 .UPDATE... ISSUED AT 928 PM MDT MON APR 2 2012 AT 0330Z RAIN CONTINUES TO MOVE NORTHWEST AROUND 25 MPH IN RESPONSE TO LOW PRESSURE SPINNING ACROSS EAST CENTRAL NEW MEXICO. NORTH TO NORTHEAST WINDS CONTINUE TO GUST AROUND 40 MPH. FOR TONIGHT ALLOWED WIND ADVISORY TO EXPIRE. WIND GUSTS IN EXCESS OF 45 MPH ARE NO LONGER EXPECTED. FORECAST CHALLENGE FOR THE NEXT 20 HOUR OR SO IS PLACEMENT OF THE HIGHEST POPS/QPF AND SNOW. GENERALLY THINKING IS FOR CURRENT BAND OF PRECIPITATION TO MOVE NORTHWEST THROUGH THE FORECAST AREA DURING THE REMAINDER OF THE NIGHT WITH SOME DRIER MID LEVEL AIR CURRENTLY OVER THE TEXAS PANHANDLE TO QUICKLY MOVE NORTH BRINGING AN END TO THE HEAVIER PRECIPITATION (EXCEPT THE NORTHWEST 1/4 OF THE AREA) BY SUNRISE. FLAGLER CURRENT TEMP IS 37...NAM AND TO A LESSER EXTENT RUC LOWER TEMPERATURES INTO THE LOWER 30S BY SUNRISE WHICH WOULD SUPPORT SNOW VS ANY MIX OF RAIN AND SNOW. HOW FAR EAST THESE COLDER TEMPERATURES GET IS THE BIG QUESTION AS THE NAM PUSHES THEM AS FAR EAST AS THE CO/KS BORDER WHILE THE HRRR IS SLIGHTLY FURTHER WEST AND THE SREF FURTHER WEST TOWARD SEIBERT. RIGHT NOW ONLY HAVE SNOW ACCUMULATIONS OF A FEW INCHES CONFINED TO THE FLAGLER AREA AND MIDNIGHT SHIFT WILL NEED TO MONITOR JUST HOW FAR EAST THE COLDER TEMPERATURES GET. GIVEN THE EXPECTED PRECIPITATION SEVERAL INCHES OF ACCUMULATION IS CERTAINLY POSSIBLE. HAVE UPDATED HWO TO MENTION THE ACCUMULATION POSSIBILITIES. FOR TUESDAY LOWERED TEMPERATURES ACROSS THE ENTIRE AREA AS WE WILL BE UNDER EXTENSIVE CLOUD COVER. 00Z NAM/21Z SREF/00Z MET AND 18Z MAV 3 HOUR TEMPERATURES ALL IN PRETTY GOOD AGREEMENT WITH HIGHS RANGING FROM THE MID 30S TO LOW 40S ACROSS FAR EASTERN COLORADO TO THE MID 40S AND LOW 50S EAST OF THE BORDER. SHOULD HAVE ANOTHER BATCH OF RAIN MOVING IN FROM THE SOUTH DURING THE DAY WITH HIGHEST AMOUNTS GENERALLY SOUTH OF A LINE FROM YUMA TO COLBY AND GOVE. UPDATE ISSUED AT 541 PM MDT MON APR 2 2012 LINE OF SHOWERS AND THUNDERSTORMS JUST EAST-SOUTHEAST OF THE FORECAST AREA MOVING NORTHWEST AT 20-25 MPH. THIS WILL PUT THEM INTO THE SOUTHEAST PORTION OF THE AREA BY 01Z IF NOT A LITTLE SOONER. ALTHOUGH INSTABILITY REMAINS HIGHER TO THE SOUTHEAST OF OUR AREA CANT RULE OUT A FEW LIGHTNING STRIKES SO UPDATED TO INCLUDE SOME THUNDER MENTION. OTHER CHANGES WERE TO BEEF UP THE CLOUDINESS TONIGHT THROUGH TUESDAY AS LOW LEVEL MOISTURE AND CLOUDS COVER THE FORECAST AREA. OTHER CHANGES TO BE MADE LATER AS 00Z MODEL DATA COMES IN. && .SHORT TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 221 PM MDT MON APR 2 2012 PLAN TO LET THE WIND ADVISORY GO TO EXPIRATION AT 03Z. THIS SHOULD WORK OUT WELL SINCE HAVE ALREADY STARTED TO DECREASE. THE NAM MIXED LAYER WINDS INDICATE THAT THEY FALL AT OR JUST BELOW WIND ADVISORY LEVELS AT 03Z. THE GFS MIXED LAYER WIND KEEPS IT WINDY OVER THE SOUTHWEST THROUGH THE NIGHT. THIS IS PROBABLY AN OUTLIER SINCE THE TREND FOR WINDS IN THAT PART OF THE AREA IS SIMILAR TO THE REST OF THE FA. THE EVENING SHIFT WILL NEED TO DETERMINE WHETHER THE ADVISORY SHOULD BE EXTENDED IN TIME. THE UPPER LOW WILL MOVE NORTHEAST TONIGHT. THERE IS SOME UNCERTAINTY AS TO HOW QUICKLY PRECIPITATION WILL MOVE NORTHWARD SINCE THE MODELS DO NOT HAVE THE LOW AS FAR SOUTH AS ITS ACTUAL POSITION ON WATER VAPOR IMAGERY. NEVERTHELESS HAVE INTRODUCED CHANCE POPS FOR THE SOUTHERN ZONES THIS EVENING. BETTER CHANCES SHOULD TAKE PLACE AFTER MIDNIGHT TONIGHT AS THE LOW HAS MORE TIME TO MOVE NORTH. FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL GET COLD ENOUGH FOR A FEW HOURS AROUND SUNRISE IN EASTERN COLORADO FOR A MIX OF RAIN/SNOW. THE NAM SHOWS A LULL IN THE PRECIPITATION TUESDAY MORNING WITH THE PASSAGE OF THE INITIAL SHORTWAVE SO WILL KEEP CHANCE POPS IN PLACE FOR TUESDAY MORNING. BY AFTERNOON THE NEXT WAVE IS PROGGED TO MOVE THROUGH THE FA SO WILL INCREASE TO HIGH CHANCE. LOW TEMPERATURES TONIGHT WILL GET DOWN TO 32 IN FAR WESTERN PORTIONS OF THE FA. OTHERWISE TEMPERATURES WILL RANGE FROM THE MID 30S FROM NEAR THE COLORADO BORDER TO THE LOWER 40S IN MCK AND HLC. MAX TEMPERATURES WILL RANGE FROM THE UPPER 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 221 PM MDT MON APR 2 2012 MAIN FOCUS WILL CONTINUE TO BE THE CLOSED LOW AND PRECIP. CHANCES THROUGH WEDNESDAY. MODELS ARE IN BETTER AGREEMENT WITH THE TRACK OF THE CLOSED LOW AS IT MOVES NORTHEAST. NOTICED THE 0Z ECMWF AND LATEST NAM/SREF ARE IN BETTER AGREEMENT THAN YESTERDAY. AS MENTIONED ABOVE...AM CONCERNED THE MODELS DID NOT INITIALIZE THE CLOSED LOW FAR ENOUGH SOUTH BASED MORNING WATER VAPOR IMAGERY. WITH THE CLOSED LOW BEING FURTHER SOUTH THAN WHAT THE MODELS HAVE...AM THINKING IT WILL LIFT FURTHER EAST THAN WHAT THE NAM/SREF/ECMWF HAVE. AS SUCH WILL TRENDED HIGHER POPS FURTHER EAST FOR TUESDAY NIGHT THROUGH WEDNESDAY BASED ON ABOVE CONCERNS. TUESDAY NIGHT THE LEFT EXIT OF THE UPPER LEVEL JET MOVES OVER THE EASTERN PART OF THE AREA AND ISENTROPIC LIFT INCREASES AS THE CLOSED LOW APPROACHES. OVER THE NORTHERN HALF OF THE AREA DEEP LIFTING SETS UP AND A BAND OF FRONTOGENESIS DEVELOPS. AS THE CLOSED LOW MOVES EAST THROUGH THE NIGHT THE LIFT FOLLOWS. TRENDED POPS IN THE SAME DIRECTION...WITH THE BEST CHANCES GENERALLY OVER THE EASTERN PART OF THE AREA WHERE THE BEST LIFT AND HIGHEST CERTAINTY WILL BE WITH LOWER CHANCES TO THE WEST WHERE THE I AM MORE UNCERTAIN THAT THE LIFT WILL DEVELOP BE AS THE SYSTEM MOVES EAST. AREAS OF EASTERN COLORADO MAY SEE A MIX OF RAIN AND SNOW AS TEMPERATURES DIP TO THE FREEZING POINT. NAM POINT SOUNDINGS SUGGEST A WINDOW OF FREEZING DRIZZLE DURING THE OVERNIGHT AND EARLY MORNING HOURS. HOWEVER SREF PRECIP. TYPE FIELDS ONLY SHOW A MIX OF RAIN AND SNOW. WILL JUST MENTION THE RAIN/SNOW MIX THROUGH THE NIGHT AND EARLY MORNING HOURS DUE TO UNCERTAINTY OF THE TRACK OF THE STORM SYSTEM. WEDNESDAY ISENTROPIC LIFT DWINDLES TOWARD THE WEST AS THE CLOSED LOW DEPARTS. HAVE PRECIP. CHANCES HIGHEST IN THE EAST WHERE THE FORCING FOR LIFT IS BEST WITH CHANCES DECLINING TO THE WEST. THROUGH THE DAY PRECIP. CHANCES DECLINE ACROSS THE AREA AS THE CLOSED LOW MOVES FURTHER EAST...WITH THE PRECIP. CHANCES COMING TO AN END OVER THE FAR EAST BY EARLY EVENING. FOR THURSDAY THROUGH MONDAY AN UPPER LEVEL SHORT WAVE RIDGE MOVES OVER THE AREA THURSDAY BEHIND THE EXITING STORM SYSTEM. BY THURSDAY NIGHT THE UPPER LEVEL FLOW TURNS TO THE NORTHWEST AHEAD OF THE NEXT UPPER LEVEL TROUGH MOVING ACROSS THE INTER MOUNTAIN WEST. PRECIPITATION CHANCES RETURN TO THE EASTERN PART OF THE AREA THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A COUPLE UPPER LEVEL SHORT WAVE TROUGHS MOVE OVER THE AREA. WITH THE LOW LEVEL JET AND ISENTROPIC LIFT AHEAD OF THE TROUGHS...A FEW SHOWERS AND/OR THUNDERSTORMS WILL BE POSSIBLE OVER THE EASTERN PART OF THE AREA. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD...WITH A WARMING TREND THURSDAY AND FRIDAY. COOLER BUT ABOVE NORMAL TEMPERATURES RETURN THROUGH THE REST OF THE PERIOD BEHIND A COLD FRONT THAT MOVES THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1032 PM MDT MON APR 2 2012 RUC IS HANDLING THE CLOUDS FAIRLY WELL SO HAVE USED THIS MODEL AS WELL AS THE HRRR CONCERNING THE PRECIPITATION. MVFR CIGS AT BOTH KGLD AND KMCK TO CONTINUE THROUGH THE NEXT 24 HOURS. BAND OF PRECIPITATION WILL IMPACT BOTH TERMINALS AT THE BEGINNING OF THE TAF PERIOD AND CONTINUE THROUGH 10Z-11Z BEFORE ROTATING OUT OF THE AREA AS MID LEVEL DRY SLOT MOVES IN. THERE IS A CHANCE FOR SEVERAL HOURS OF IFR CONDITIONS AT BOTH TERMINALS TIL 16Z OR SO WHEN ANOTHER BATCH OF PRECIP MOVES NORTH IMPACTING KGLD AROUND 16Z AND KMCK AROUND 00Z. THIS BATCH OF PRECIP SHOULD CONTINUE THROUGH THE REMAINDER OF THE TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...007 SHORT TERM...FS LONG TERM....JTL AVIATION...BAS/DDT
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1144 PM CDT MON APR 2 2012 .AVIATION... ...06Z AVIATION DISCUSSION... CONVECTION DEVELOPING ALONG A STALLED OUTFLOW BOUNDARY EXTENDING ALONG THE LOUISIANA COAST WILL BE THE MAIN FEATURE IMPACTING AREA TERMINALS THROUGH AT LEAST 10Z. EXPECT CONVECTION TO IMPACT KHUM...KMSY...KNEW...KASD...KHSA...AND KGPT THROUGH 09-10Z THIS MORNING. THIS CONVECTION WILL PRODUCE PERIODS OF IFR CONDITIONS...STRONG WIND GUSTS...AND LIGHTNING AS IT MOVES THROUGH. AFTER 10Z...AN UPPER LEVEL FEATURE DRIVING THE CONVECTIVE DEVELOPMENT WILL PASS BY THE REGION. THIS WILL ALLOW SOME DRIER AIR TO FILTER INTO THE AREA...CUTTING OFF CONVECTIVE POTENTIAL. EXPECT TO SEE SOME PATCHY FOG AND LOW CEILINGS DEVELOP AROUND 12Z...WITH AREAS SEEING IFR AND LIFR CEILINGS TAKE HOLD...AS WELL AS SOME IFR VISIBILITIES. WINDS WILL INCREASE BY 15Z...AND WILL BE ABOVE 12 KNOTS FROM 15Z TO AROUND 03Z TOMORROW NIGHT. CLOUDS WILL BREAK OUT...AS DRIER AIR MIXES DOWN TO THE SURFACE ALLOWING FOR VFR CONDITIONS AT ALL TERMINALS BY 18Z. 32 && .PREV DISCUSSION... /ISSUED 935 PM CDT MON APR 2 2012/ UPDATE...CONVECTION IS BEING RATHER STUBBORN. OLD OUTFLOW BNDRY CONTINUES TO WORK EAST ACROSS COASTAL MS BUT HAS BASICALLY STALLED OVER COASTAL LA. IN FACT WHERE THE BNDRY IS ANCHORED(OVER TERREBONNE...ST MARY...ASSUMPTION...AND ST MARTING PARISHES) IT IS INTERACTING WITH A COOL POCKET NOTED BY THE RUC. THE RUC IS THE ONLY MODEL EVEN NOTICING IT RIGHT NOW AS ALL OF THE OTHER HIRES SHORT RANGE MDLS(12-36 HRS) ARENT EVEN HANDLING THE CURRENT CONVECTION. THE RUC IS SHOWING THIS COOL POCKET MOVING TO THE NORTH AND BECOMING ELONGATED FROM NNW-SSE OVER THE WRN QUARTER OF OUR CWA. WITH THAT I HAVE INCREASED POPS GREATLY FOR OUR SW AND WEST FOR OVERNIGHT. THERE IS THE POSSIBILITY THAT THERE COULD BE SOME RATHER HEAVY RAINFALL SOMEWHERE OVER ASSUMPTION...NRN TERREBONNE...NWRN LAFOURCHE...ST JAMES...AND MAYBE INTO IBERVILLE AND ASCENSION PARISHES OVERNIGHT. CONVECTION SOUTH OF THE NO METRO SHOULD CONTINUE TO SLOWLY DRIFT SOUTH AND WEAKEN OVERNIGHT. GRIDS AND ZONES ARE OUT. /CAB/ && .PRELIMINARY POINT TEMPS/POPS... MCB 66 85 67 83 / 20 40 40 50 BTR 68 85 71 83 / 40 40 40 50 ASD 67 85 69 82 / 20 30 40 50 MSY 71 85 72 82 / 30 30 40 50 GPT 70 81 72 80 / 20 30 40 40 PQL 67 82 71 80 / 20 30 20 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
534 AM EDT TUE APR 3 2012 .SYNOPSIS... ISSUED AT 533 AM EDT TUE APR 3 2012 RIDGE OVER THE AREA SINCE LATE IN THE WEEKEND IS BEING FLATTENED OUT THIS MORNING AS STRONG SHORTWAVE TROUGH SLIDES FM MANITOBA INTO NORTHWEST ONTARIO. HEIGHT FALLS ARE SUBTLE OVR UPR LAKES PER 00Z RAOBS BUT ENOUGH TO TRIGGER MULTIPLE CLUSTERS OF SHRA/TSRA OVR THE UPPER GREAT LAKES. FRONTAL BOUNDARY...EXTENDING SOUTH OUT OF LOW OVR NORTHERN ONTARIO AND ALSO EXTENDING TO THE NORTH FM LOW OVR MID MISSISSIPI RIVER VALLEY WILL CROSS UPR MICHIGAN THIS MORNING. COOLER AIRMASS ADVECTS OVR THE AREA LATER TODAY THROUGH TONIGHT AND WEDNESDAY. AFTER THE FROPA THIS MORNING...DRY WEATHER WILL PREVAIL THROUGH LATE THIS WEEK AS LARGE HIGH PRESSURE IS DOMINANT WEATHER FEATURE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 533 AM EDT TUE APR 3 2012 TODAY...CONVECTIVE TRENDS WILL BE CHALLENGING THIS MORNING...BUT AFTER THAT DRYING TREND WILL FIRMLY TAKE HOLD. AS OCCURRED 24 HR AGO...MAIN AREA OF CONVECTION OVERNIGHT HAS DEVELOPED CLOSER TO H7 MOIST AXIS AND ALSO IN AREA OF H85 TEMP ADVECTION. INITIAL SHRA/TSRA HEADING QUICKLY INTO THE FAR EAST CWA FORMED AHEAD OF ONTARIO SHORTWAVE TROUGH AND HAVE BEHAVED FOLLOWING STEADY EASTWARD MOTION. CONVECTION OVR MN AND WESTERN WI IS OUTLINED WELL BY WHERE RUC13 SHOWS MAXIMUM H7 MOISTURE TRANSPORT AND ON NORTHERN EDGE OF STEEPER H7-H5 LAPSE RATES AOA 8C/KM. AT THIS TIME...MAJORITY OF TSRA ARE OCCURRING OVR CNTRL WI BUT ADDITIONAL SHRA WITH EMBEDDED TSRA ARE FILLING IN INTO NORTHWEST WI. FOLLOWING RUC IDEA THERE IS ENOUGH H7 MOISTURE TRANSPORT INTO SCNTRL CWA TO KEEP HIGHER POPS THERE IN THE MORNING. A FEW SHRA/TSRA MAY EVEN CLIP AREAS FARTHER NORTH IN THE CNTRL CWA BUT IT IS FAIRLY LIMITED CHANCE AS THE AREA OF SHRA/TSRA OVR NORTHWEST WI WILL BE OUTRUNNING BETTER H7 MOISTURE CONVERGENCE AND ELEVATED INSTABILITY IF THEY CONTINUE ON ENE TRACK. OVERALL IMAGINE CHANCES OF CONVECTION WILL BEGIN TO WANE SIGNIFICANTLY OVR MOST AREAS AFTER MID MORNING /POST 15Z-16Z/ SINCE SFC FRONT WILL BE DROPPING S/SE OF THE AREA BY THAT TIME. HAVE HAD SOME PEA-SIZED HAIL OVERNIGHT WITH STRONGER STORMS AND THAT REMAINS POSSIBLE THIS MORNING GIVEN STEEP LAPSE RATES JUST UPSTREAM AND 30-35 KTS OF EFFECTIVE SHEAR FCST OVR CNTRL PORTIONS OF UPR MI. AS ALLUDED TO BEFORE...COLD FRONT WILL STEADILY SLIDE ACROSS THE AREA MID TO LATE MORNING. WINDS IN WAKE OF FRONT EXPECTED TO BECOME NORTH TO NORTHWEST. STILL APPEARS THAT THERE COULD BE BRIEF PERIOD OF LOWER CIGS AND MAYBE SOME FOG AS HIGHER DWPNTS JUST BEHIND FRONT SETTLE ACROSS LK SUPERIOR AND WINDS PROVIDE SOME UPSLOPE LIFTING OVR HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL CWA. POSSIBILITY FOR FOG MAY HAVE BEEN ENHANCED DUE TO THE DECENT COVERAGE OF SHRA/TSRA OVR LK SUPERIOR OVERNIGHT THAT MAY HAVE PROVIDED ADDITIONAL LOW-LEVEL MOISTENING. LOOKING UPSTREAM THERE IS AREA OF LOWER CLOUDS NORTHWEST OF LK SUPERIOR BUT THERE IS ALSO A MUCH LARGER AREA OF VERY DRY AIR/CLEAR SKIES PUSHING ACROSS MANITOBA AND NORTHWEST ONTARIO. REALLY HARD TO TELL AT THIS POINT HOW MUCH/IF ANY FOG IS PRESENT OVR WESTERN LK SUPERIOR...SO WILL NOT INCLUDE IN FCST FOR LATER THIS MORNING. EXPECT DRYING TO WIN OUT PRETTY EASILY AFTER MID AFTN ONCE BLYR DWPNTS FALL INTO THE LOWER 30S/MID-UPR 20S AS HIGH BEGINS TO NOSE INTO LK SUPERIOR REGION. SO SKY FCST SHAKES OUT AS FAIRLY CLOUDY IN THE MORNING BUT WITH FAIRLY SHARP CLEARING TREND BY MID AFTN FM WEST-TO-EAST. DESPITE THE SUNSHINE THIS AFTN...TEMPS SHOULD BE HELD DOWN MOST AREAS WITH GRADIENT WIND FLOWING OFF LK SUPERIOR. PROBABLY WILL SEE STEADY TEMPS ALONG LK SUPERIOR AND READINGS PUSHING INTO LOWER 50S FAR INLAND/LK MICHIGAN SHORE WITH LESS LAKE MODIFICATION GIVEN THE NORTHWEST WINDS. DWPNTS AND RH VALUES COULD CRASH OVR INTERIOR WEST BY LATE AFTN. CURRENT FCST HAS RH VALUES IN THE 30-40 PCT RANGE...BUT IF WINDS STAY MORE NW IT COULD GET WARMER WHICH WOULD RESULT IN RH VALUES BLO 30 PCT. VERY DRY AIRMASS BECOMES FIRMLY ENTRENCHED OVR AREA TONIGHT INTO WEDNESDAY AS HIGH PRESSURE BUILDS FM HUDSON BAY INTO THE WESTERN GREAT LAKES. NORTHERLY FLOW REMAINS OFF LK SUPERIOR BUT GIVEN PWATS FALLING TOWARD 50 PCT OF NORMAL...EXPECT INTERIOR CWA TO TRY TO DECOUPLE TONIGHT AND COOL OFF TOWARD THE LOWER DWPNTS ADVECTING INTO THE REGION. BENEATH MOSTLY SUNNY SKIES ON WEDNESDAY...MAIN CONCERN WILL BE ON FIRE WX WITH LOWER RH VALUES. HAVE DWPNTS IN AFTN MIXING OUT INTO THE UPR TEENS OVR INTERIOR SECTIONS...RESULTING IN RH VALUES BLO 30 PCT. WINDS WILL NOT BE VERY GUSTY /LEADING TO LESS IMPACT ON FIRE WX CUSTOMERS/ BUT A STEADY NORTH WIND UP TO 15 MPH IS EXPECTED. GIVEN THE FLOW...PROBABLY WILL HAVE TOUGH TIME REACHING 40 DEGREES ALONG LK SUPERIOR SHORE. MIXING HEIGHTS MUCH HIGHER TOWARD WI BORDER /H85-H8 PER FCST SOUNDINGS/ ALLOW TEMPS TO RISE WELL INTO THE 50S. OVERALL LOOKS LIKE PRETTY TYPICAL SPRING PATTERN. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 533 AM EDT TUE APR 3 2012 HIGH PRESSURE WILL DOMINATE MUCH OF THIS PERIOD. WHILE THE SFC RIDGE WILL BE OVERHEAD AT 00Z THURSDAY...THE MAIN HIGH WILL LIKELY RESIDE OVER HUDSON BAY AND NW ONTARIO. EXPECT THE CENTER OF HIGH PRESSURE TO SLOWLY SIDE OVER LAKE SUPERIOR THURSDAY INTO FRIDAY. DRY AIR WILL CONTINUE TO SLIDE INTO THE AREA FROM EASTERN ONTARIO...WITH HUMIDITY VALUES FALLING 25 TO 25 PERCENT THURSDAY AND FRIDAY AFTERNOON AWAY FROM THE LAKE SUPERIOR COASTLINE. ON THE PLUS SIDE...WINDS SHOULD BE FAIRLY LIGHT...LESS THAN 10KTS AWAY FROM ANY LAKE BREEZES THAT MAY COME IN THURSDAY AND FRIDAY AFTERNOON. STILL...IT WILL BE ENOUGH TO INCREASE FIRE WEATHER CONCERNS OVER UPPER MICHIGAN THROUGH THE REMAINDER OF THE WORK WEEK. THERE WILL BE A SUBTLE CHANGE FRIDAY...AS THE HIGH PRESSURE SYSTEM BEGINS TO SHIFT EASTWARD IN RESPONSE TO A SFC LOW ORGANIZING OVER EASTERN WY/MT INTO THE WESTERN DAKOTAS. LOOK FOR A SLOW RETURN TO S/SE WINDS FRIDAY INTO FRIDAY NIGHT. THE PRESSURE GRADIENT WILL TIGHTEN OVER THE WEEKEND. EXPECT INCREASED S/SE WINDS OF 10 TO 15KTS SATURDAY /AHEAD OF THE COLD FRONT CROSSING SATURDAY NIGHT/. SPECIFICS FOR THIS PERIOD ARE A LITTLE TRICKY...WITH THE BREAKDOWN OF THE 500MB RIDGE SATURDAY NIGHT AS THE MAIN LOW REMAINS WELL TO OUR NORTH. THE 03/00Z RUN OF THE ECMWF CONTINUES TO SHOW LIMITED MOISTURE...WITH LITTLE MORE THAN A TRACE OF RAIN FALLING SATURDAY NIGHT AS MUCH OF THE ENERGY REMAINS WRAPPED UP ACROSS CANADA MAINLY ON THE BACK SIDE OF THE LOW. THE 03/00Z RUN OF THE GFS ON THE OTHER HAND INDICATES THE POTENTIAL FOR AROUND A TENTH OF AN INCH OF WELL NEEDED RAIN...WITH STILL THE BEST CHANCE BEHIND THE LOW. GIVEN THE LOW POTENTIAL FOR EVEN RAIN...KEPT ONLY SLIGHT CHANCE TS IN THE FCST FOR SATURDAY AFTERNOON INTO SATURDAY NIGHT. WINDS WILL REMAIN STRONGER ON THE ORDER OF 15 TO 20KTS OUT OF THE W BEHIND THE COLD FRONT AS THE SFC LOW SHIFTS FROM NEAR LAKE WINNIPEG AT 12Z SATURDAY...TO NORTHERN ONTARIO/HUDSON BAY ON SUNDAY. NO SIGNIFICANT WARM UP IS IN SIGHT...WITH 850MB TEMPS HOVERING AROUND 0C SUNDAY WITH TEMPS FALLING TO AROUND -8C MONDAY AFTERNOON ON N-NW WINDS OFF LAKE SUPERIOR. DID NOT GO WITH FALLING SFC TEMPS FOR MONDAY QUITE YET...EVEN THOUGH BOTH THE GFS AND ECMWF LOOK FAIRLY CONSISTENT WITH THIS IDEA. AS NOTED IN THE PREVIOUS DISCUSSION...WRAP AROUND MOISTURE LOOKS TO BET BEHIND THE LOW...PARTICULARLY IN NW FLOW OFF LAKE SUPERIOR CAN LINGER OVER THE CWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 155 AM EDT TUE APR 3 2012 FORCING AHEAD OF FRONTAL BOUNDARY /CURRENTLY OVER WESTERN LAKE SUPERIOR/ HAS PROMPTED SOME CONVECTIVE SHOWERS AND THUNDERSTORMS WHICH ARE CURRENTLY MOVING FROM WEST TO EAST ACROSS UPPER MI AND ALSO DEVELOPING UPSTREAM OVER PORTIONS OF MN AND WESTERN WI. HAVE MENTION OF VCTS AND CB FOR ALL TAF SITES TO ACCOUNT FOR THE SHOWER ACTIVITY THROUGH LATE TONIGHT INTO TUESDAY MORNING. ONCE FRONTAL BOUNDARY PASSES THROUGH TAF SITES EXPECT WINDS TO SHIFT TO A MORE NORTHERLY DIRECTION AND FOR CIGS TO DROP TO MVFR AT ALL TAF SITES...THOUGH MODELS ARE SHOWING HIGH LEVELS OF DISAGREEMENT ON TIMING OF THIS SHIFT. THERE IS A CONCERN FOR FOG AT KCMX AND KSAW ONCE WINDS SHIFT...SINCE COOL MOISTENED LAKE LAYER WILL BE ADVECTED ON TO THE LAND WITH A NNW FLOW. MODELS ARE NOT SHOWING THIS...AND CONFIDENCE IS LOW...SO HAVE LEFT OUT OF TAFS AT THIS TIME BUT WILL CONTINUE TO MONITOR. HIGH PRESSURE TO WEST WILL ALLOW DRY AIR AND CLEARING SKIES TO START WORKING IN FROM WEST TO EAST BY LATER TUESDAY AFTERNOON. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 533 AM EDT TUE APR 3 2012 WINDS SHOULD REMAIN LESS THAN 30KTS THROUGH THE PERIOD...GETTING NEAR THIS LEVEL W AND CENTRAL SUNDAY AFTERNOON OFF WSW WINDS. IN THE SHORTER TERM...A TROUGH OF LOW PRESSURE OVER CENTRAL AND EASTERN LAKE SUPERIOR WILL EXIT ACROSS LAKE HURON THIS EVENING. THIS WILL MAKE WAY FOR LARGE HIGH PRESSURE OVER CENTRAL CANADA AND THE NORTHERN PLAINS TO SHIFT DIRECTLY OVER THE UPPER GREAT LAKES WEDNESDAY AFTERNOON...WHERE IT WILL REMAIN THROUGH FRIDAY. A LOW DEVELOPING OVER MANITOBA AND NORTH DAKOTA SATURDAY MORNING WILL SLIDE OVER NORTHERN LAKE SUPERIOR AND ONTARIO SATURDAY NIGHT INTO SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLA SHORT TERM...JLA LONG TERM...KF AVIATION...JMW/JLA MARINE...KF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
316 AM EDT TUE APR 3 2012 .SYNOPSIS... A WEAK COLD FRONT WILL CROSS NORTHERN MICHIGAN THIS MORNING AND EARLY IN THE AFTERNOON. RAIN CHANCES WILL END BY THIS EVENING. AFTER THAT...HIGH PRESSURE WILL MOVE SOUTH OUT OF CENTRAL CANADA. THIS WILL PROVIDE QUIET WEATHER...WITH A SERIES OF CHILLY NIGHTS BUT RELATIVELY MILD DAYS. OUR NEXT CHANCE FOR RAIN WILL WAIT UNTIL SATURDAY NIGHT AND SUNDAY. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 QUITE AN AMPLIFIED PATTERN ONGOING OVER THE WESTERN HEMISPHERE EARLY THIS MORNING...WITH LARGE SCALE TROUGHS ANCHORED ALONG BOTH COASTS OF NOAM WITH A REX BLOCK-LIKE FEATURE STUCK BETWEEN THESE...KEEPING THE WEATHER SOMEWHAT INTERESTING OVER WHAT WOULD OTHERWISE BE LARGE-SCALE RIDGING. THE FOCUS FOR THE NEAR TERM AND THROUGH TODAY IS SHOWER AND THUNDERSTORM POTENTIAL AS INVERTED TROUGH PULLS INTO THE REGION FROM THE WEST. OVERNIGHT...SHOWERS AND THUNDERSTORMS HAVE MADE THE MOST OF VERY MEAGER INSTABILITY...CONTINUOUSLY FIRING ALONG THE H85 MOISTURE BOUNDARY AS IT PUSHES EAST INTO THE REGION. THROUGH DAYBREAK...I EXPECT AREAS FROM M-32 NORTH TO SEE SOME SHRA ACTIVITY /WITH A FEW EMBEDDED RUMBLES/...WITH A FEW MORE SHOWERS DOWN NEAR MANISTEE. THINGS GET TRICKIER AS WE HEAD INTO THE DAY TODAY...WITH THE IMPACTS OF ANOTHER CONVECTIVE COMPLEX NOW OVER WESTERN WISCONSIN NOT SO CERTAIN. CORFIDI VECTORS SUGGEST THAT THIS COMPLEX WILL PUSH EAST AND THEN SOUTHEAST...OVER THE TOP OF THE H5 RIDGE AXIS...WHICH WOULD SUGGEST ARRIVAL NEAR MY SOUTHWEST ZONES TOWARDS 12Z. THE HRRR IS ON BOARD WITH THIS...AS IS OUR PREVIOUS GRIDDED FORECAST AND WILL CONTINUE EARLY MORNING LIKELY POPS BASICALLY SOUTH OF M-72 AND WEST OF INTERSTATE 75. GIVEN THE TIME OF DAY...EXPECT THIS COMPLEX TO DIE AS IT MOVES EAST...WITH LITTLE TO HANG YOUR HAT ON FOR FORCING FOR THE REMAINDER OF THE DAY AS AFOREMENTIONED INVERTED TROUGH INCREASES LOW LEVEL CONVERGENCE TO SOME EXTENT. STILL...WITH MOIST PLUME OVERHEAD...AND CVA FROM WAVE NOW MOVING INTO WESTERN ONTARIO...EXPECT SOME ADDITIONAL SHOWERS TO POP UP ALONG THE H85 COLD FRONT AS IT SAGS THROUGH THE REGION THIS AFTERNOON. CONFIDENCE IS PRETTY LOW IN HOW THIS EVOLVES THIS AFTERNOON...AND THAT IS WHY I/LL KEEP POPS IN THE CHANCE CATEGORY. TEMPERATURES LIKELY WON/T MAKE TOO MUCH PROGRESS GIVEN CLOUD COVER. REALLY LIKED INHERITED HIGHS IN THE LOWER 50S /WITH A FEW MID 50S OVER SOUTHERN AREAS/ AND WILL CONTINUE THEM IN THIS PACKAGE. THIS IS TOWARDS THE COOLER END OF THE GUIDANCE ENVELOPE. TONIGHT...DRIER AIR PUSHES INTO THE REGION AS INVERTED TROUGH SCOOTS TO THE SOUTHEAST OF THE AREA WITH DEEP LAYER NORTHWEST FLOW DEVELOPING. THIS SHOULD SCOUR OUT ANY REMNANT LOW LEVEL MOISTURE...BRINGING CLEARING SKIES. WITH WINDS LIKELY TO REMAIN COUPLED...I DON/T EXPECT LOWS TO FALL ALL THAT FAR...WITH FAIRLY HOMOGENEOUS VALUES NEAR OR A LITTLE ABOVE 30 EXPECTED. WEDNESDAY...EXPANSIVE AREA OF HIGH PRESSURE BUILDS SOUTH INTO THE HUDSON BAY REGION WITH DRY NORTHWESTERLY FLOW VEERING NORTHERLY DURING THE DAY UNDER CONTINUED COLD ADVECTION. GIVEN VERY DRY ARRIVING AIRMASS...EXPECT A SUNNY/MSUNNY DAY WITH AMPLE SUBSIDENCE TO ENSURE LITTLE IN THE WAY OF CUMULUS DEVELOPMENT. WITH THE AFOREMENTIONED SUBSIDENCE...WOULDN/T BE SURPRISED IF WE DON/T MIX QUITE AS HIGH AS THE MODELS ARE ADVERTISING...AND UNDER COLD ADVECTION FEEL TEMPS WILL STRUGGLE A LITTLE. THEREFORE...WILL FOLLOW CLOSER TO THE COOLER SIDE OF THE GUIDANCE ENVELOPE /MET/ WITH HIGHS IN THE MID 40S OVER EASTERN UPPER...TO THE LOWER 50S OVER NORTHERN LOWER. GIVEN THE FLOW TRAJECTORIES AND SUBSIDENT FLOW...EXPECT A VERY DRY AIRMASS WITH DEWPOINTS LIKELY TUMBLING INTO THE UPPER TEENS BY MID/LATE AFTERNOON. THIS WILL BRING MINIMUM RH/S INTO THE 20S. WITH GUSTY NORTH/NORTHWEST WINDS...WILL CONTINUE ELEVATED FIRE DANGER WORDING IN THE MORNING HWO...BUT TEMPERATURES WILL BE WELL BELOW RED FLAG LEVELS. && .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 UPPER PATTERN REMAINS ONLY VERY SLOWLY PROGRESSIVE THRU THE REST OF THE WORK WEEK AND INTO THE WEEKEND. THAT WILL STILL EVENTUALLY BRING THE PAC NW UPPER TROF EASTWARD INTO OUR REGION...BUT LIKELY NOT UNTIL THE END OF THE WEEKEND. BEFORE THEN...THURSDAY/FRIDAY/SATURDAY CONTINUE TO LOOK RELATIVELY UNEVENTFUL...WITH SURFACE HIGH PRESSURE ENTRENCHED IN THE GREAT LAKES REGION. WED NIGHT-SAT...A REASONABLY VIGOROUS SHORTWAVE DROPS SOUTH ACROSS THE NORTHERN LAKES WED NIGHT. THIS SYSTEM IS MOISTURE-STARVED...AND WILL BRING NO MORE THAN SOME MID-HIGH CLOUDS...PRIMARILY TO EASTERN UPPER AND NE LOWER MI. HOWEVER...IT WILL PUSH A SECONDARY COLD FRONT ACROSS THE AREA...HELPING TO MAINTAIN 850MB TEMPS IN THE -6 TO -8C RANGE BY THU MORNING. WARM ADVECTION (ON N TO NE LOW LEVEL FLOW) AND AIRMASS MODIFICATION BEGIN SHORTLY THEREAFTER. BUT WE WILL STILL SEE SOMEWHAT COOLISH TEMPS...ESPECIALLY WED NIGHT AND THU NIGHT. EXPECT MINS MAINLY IN THE 20S...AND COULD DEFINITELY SEE TEENS IN THE USUAL COLD INTERIOR LOCALES. GIVEN OUR EARLY START TO THE GROWING SEASON...FROST/FREEZE HEADLINES COULD WELL BE NEEDED ON BOTH NIGHTS. WE/LL SEE ENOUGH SUN TO KEEP MAX TEMPS RESPECTABLE THURSDAY...MID 40S TO AROUND 50. RH LEVELS WILL BE PRETTY LOW DESPITE THE COOLISH TEMPS...WITH DEW POINTS IN THE TEENS (PERHAPS LOWER) AT PEAK HEATING. FOR NOW...IT LOOKS LIKE WE WON/T QUITE HAVE ENOUGH OF A NORTHERLY BREEZE TO MAKE FOR AN ENHANCED FIRE THREAT DAY. HIGH PRESSURE MOVES OVERHEAD BY FRIDAY...AND THE AIRMASS WILL CONTINUE TO MODERATE. MAX TEMPS WILL JUMP INTO THE 50S FRIDAY...AND WILL APPROACH 60F IN SPOTS SATURDAY...WITH PLENTY OF SUNSHINE. AFTER A DAY WITH HARDLY ANY WIND FRIDAY...A DEVELOPING SOUTHERLY BREEZE SATURDAY COULD ALSO PRODUCE AN ENHANCED FIRE THREAT...THOUGH FOR NOW (LIKE THURSDAY) FORECAST WINDS AREN/T QUITE STRONG ENOUGH. LATER PERIODS...TIMING AGREEMENT REMAINS DECENT ON LOW PRESSURE LIFTING TOWARD HUDSON BAY SAT NIGHT/SUNDAY...AND AN ASSOCIATED COLD FRONT CROSSING MI LATE SAT NIGHT/SUNDAY MORNING. CHANCE POPS STILL IN ORDER WAY OUT THEN. DEPENDING ON YOUR MODEL SOLUTION OF CHOICE... MAY HAVE ENOUGH COOL AIR AND DEEP CYCLONIC FLOW TO PRODUCE A CHANCE FOR RAIN/SNOW SHOWERS ON MONDAY. THE OPERATIONAL GFS IS AMONGST THE CHILLIEST/MOST MOIST BY MONDAY...IT HAS BEEN KNOWN TO OVERDUE THESE SORTS OF THINGS FROM TIME TO TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 138 AM EDT TUE APR 3 2012 A TROUGH OF LOW PRESSURE IS BEGINNING TO PULL INTO THE REGION AS OF THIS WRITING...WITH A BAND OF SHOWERS OVER EASTERN UPPER MICHIGAN...AND ADDITIONAL ACTIVITY FIRING FURTHER WEST BACK OVER WESTERN WISCONSIN. EXPECT GRADUALLY LOWERING MID/HIGH CLOUDS THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...WITH A SHRA POSSIBLE BEFORE DAYBREAK AT PLN/TVC/MBL. OTHERWISE...EXPECT STEADIER PRECIPITATION TO REACH MBL/TVC AROUND DAYBREAK /MISSING APN AND PLN TO THE SOUTH/ AND LAST THROUGH THE MORNING /PROVIDING SOME MVFR VSBYS/ WITH A FEW EMBEDDED THUNDERSTORMS POSSIBLE. AFTER THIS PUSHES THROUGH...EXPECT WE/LL SEE SOME MVFR CIGS DEVELOP BEFORE MUCH DRIER AIR ARRIVES TOWARDS THIS EVENING...CLEARING THINGS OUT. LLWS A THREAT THROUGH DAYBREAK AS 1.5KFT WINDS ARE NEAR 30KTS AT MBL/TVC/PLN BASED ON VWP ANALYSIS ALONG WITH NEAR TERM MODEL FORECAST SOUNDINGS. THIS THREAT SHOULD DIMINISH AFTER SUNRISE. LIGHT WINDS WILL BECOME SOUTHERLY AROUND 5KTS FOR THE MORNING BEFORE SHIFTING NORTHWEST AND INCREASING TO 8G14KTS FOR THE AFTERNOON. NORTHWEST WINDS 5-10KTS /EXCEPT NORTHEAST AT MBL/ ARE EXPECTED AS WE HEAD INTO THIS EVENING. && .MARINE... ISSUED AT 313 AM EDT TUE APR 3 2012 WINDS/WAVES LOOK TO GENERALLY REMAIN BELOW LEVELS HAZARDOUS TO SMALL CRAFT THROUGH TUESDAY NIGHT AS TROUGH OF LOW PRESSURE MOVES THROUGH THE REGION TODAY WITH NORTHWESTERLY WINDS DEVELOPING LATE THIS AFTERNOON AND TONIGHT. THESE NORTHWESTERLY WINDS WILL STRENGTHEN ON WEDNESDAY AS CANADIAN HIGH PRESSURE BUILDS TOWARDS THE REGION. THIS WILL LIKELY BRING A PERIOD OF SMALL CRAFT CONDITIONS ON WEDNESDAY BEFORE THE AFORMENTIONED HIGH SETTLES OVERHEAD WITH QUIET CONDITIONS FOR THE END OF THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JA SYNOPSIS...JZ SHORT TERM...JA LONG TERM....JZ AVIATION...JA MARINE...JA
AREA FORECAST DISCUSSION
NWS HASTINGS NE
355 AM CDT TUE APR 3 2012 .SHORT TERM...THROUGH THURSDAY NIGHT. PRIMARY CHALLENGE OVER THE NEXT 72 HOURS IS CLEARLY RAINFALL TRENDS/AMOUNTS...AS THE MID LEVEL LOW CURRENTLY CENTERED OVER EASTERN NEW MEXICO GRADUALLY LUMBERS EASTWARD NEAR THE OK/KS BORDER...AND EVENTUALLY INTO THE MID-SOUTH BY THURSDAY. CERTAINLY PARTS OF THE CWA ARE GOING TO SEE SOME WELL-TIMED BENEFICIAL RAINS IN EXCESS OF 0.75-INCH. ALSO NOT GOING TO SEE MUCH SUNSHINE FOR THE NEXT FEW DAYS. STARTING OFF EARLY THIS MORNING...08Z OBJECTIVE SURFACE ANALYSIS SHOWS THE CWA LOCATED WELL NORTH OF THE PRIMARY SURFACE COLD FRONT STRETCHED NORTHEAST ACROSS SOUTHEAST KANSAS FROM A FAIRLY WEAK LOW OVER THE TX PANHANDLE. WELL OFF TO THE NORTHWEST...A BROAD...ROUGHLY 1025 MB HIGH PRESSURE SYSTEM IS CENTERED ACROSS THE NORTHERN ROCKIES INTO ND. WITH THE CWA POSITIONED WITHIN THE HEART OF THE MAIN NORTH-SOUTH SURFACE PRESSURE GRADIENT...STEADY NORTH WINDS HAVE PREVAILED ALL NIGHT...WITH SUSTAINED SPEEDS COMMONLY 20-30 MPH WITH HIGHER GUSTS...BUT GENERALLY FALLING SHORT OF WIND ADVISORY CRITERIA IN MOST PLACES. RADAR...11-3.9 MICRON SATELLITE IMAGERY AND AUTOMATED OBS DEPICT A CORRIDOR OF WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS CENTERED OVER CENTRAL/NORTHWEST KANSAS...WITH SOME OF THIS ACTIVITY STARTING TO INCREASINGLY AFFECT AREAS MAINLY SOUTHWEST OF A BEAVER CITY-BELOIT LINE. AS FOR RAINFALL AMOUNTS IN THE PAST 12 HOURS...RADAR ESTIMATES THAT POCKETS OF THE SOUTHERN CWA...MAINLY THE KS COUNTIES...HAVE LIKELY TALLIED BETWEEN 0.25-0.50 INCH...ALTHOUGH MOST AREAS PROBABLY LESS. OTHERWISE...AN EXPANSIVE AREA OF LOW STRATUS MAINLY IN THE 800-1800 FT RANGE HAS OVERTAKEN THE ENTIRE CWA...WITH JUST A HINT OF LIGHT DRIZZLE IN THE AIR HERE AT THE WFO. UP TOP...WATER VAPOR SATELLITE CLEARLY DEPICTS THE AFOREMENTIONED CLOSED LOW CENTERED NEAR THE NM/TX BORDER...WHILE A RATHER PRONOUNCED RIDGE DOMINATES MUCH OF THE EASTERN CONUS. GETTING TO THE FORECAST AND STARTING WITH TODAY...IMMEDIATE SHORT TERM ISSUE OVER THE NEXT 4-6 HOURS IS PROGRESSION OF NEXT BATCH OF GENERALLY WEAK CONVECTION RIDING UP INTO SOUTHERN ZONES. WILL BE ISSUING A PRE-FIRST PERIOD ZONE FORECAST PACKAGE...WITH LIKELY POPS THROUGH 12Z FOR LOCATIONS MAINLY SOUTH OF A BEAVER CITY- BELOIT LINE. WITH RUC ADVERTISING AT LEAST 500 J/KG MUCAPE IN THESE AREAS...OCCASIONAL SMALL HAIL AND BRIEF BUT FREQUENT LIGHTNING STRIKES CERTAINLY ARE POSSIBLE EARLY THIS MORNING. OTHERWISE...FOLLOWING LATEST HRRR REFLECTIVITY PROGS...ALONG WITH 00Z 4KM WRF-NMM....MUCH OF THIS ACTIVITY SHOULD DECREASE IN COVERAGE...AND FAIL TO PUSH VERY FAR INTO THE NEB CWA OVER THE NEXT FEW HOURS AS THE SMALL SCALE SHORTWAVE CURRENTLY OVER NORTHWEST KS ROTATES BACK MORE TO THE WEST-NORTHWEST. MOVING ON TO THE DAYTIME 12Z-00Z TIME FRAME...ASSUMING THAT THE CURRENT CONVECTION DISSIPATES OR MOVES OUT BY AROUND SUNRISE...REALLY NOT EXPECTING A WHOLE LOT OF PRECIP POTENTIAL FOR THE MAJORITY OF THE CWA...AS THE LOCAL AREA REMAINS IN A BIT OF A LULL IN BETWEEN PUSHES OF MID/UPPER FORCING...WAITING FOR THE NEXT PRIMARY CHUNK OF ENERGY TO ROTATE NORTHWARD OUT OF THE SOUTHERN PLAINS AHEAD OF THE UPPER LOW. AS A RESULT...ACTUALLY HAVE NO PRECIPITATION MENTIONED WHATSOEVER ACROSS ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH THE DAY...AND ONLY 20-50 PERCENT POPS ACROSS SOUTHWEST ZONES...WITH EVEN THIS POTENTIALLY BEING TOO MUCH. EVEN IN AREAS WITH NO EXPECTATION OF MEASURABLE PRECIP...SUPPOSE SOME PATCHY DRIZZLE COULD CONTINUE PAST SUNRISE...BUT WILL LEAVE IT OUT FOR NOW AND TAKE ANOTHER LOOK ON UPDATE IN A FEW HOURS. IF ANY CONVECTION DOES SURVIVE/MOVE IN DURING THE DAY...ISOLATED THUNDER POTENTIAL IS CERTAINLY THERE WITH CONTINUED MUCAPE AVERAGING GENERALLY BELOW 500 J/KG...BUT POSSIBLY COULD BE ENOUGH TO GENERATE SOME SMALL HAIL. AS FOR HIGH TEMPS TODAY...FEEL THAT AT LEAST SLIGHTLY UNDERCUTTING MET/MAV GUIDANCE CONSENSUS IS THE WAY TO GO...AS LOW CLOUDS AND STEADY NORTHERLY BREEZES OF 15-25 MPH WILL PERSIST THROUGH THE DAY. MAY STILL BE TOO WARM IN SPOTS...BUT FOR NOW WILL AIM FOR MID-UPPER 50S IN MOST WESTERN AREAS...AND MAYBE SOME LOW 60S IN THE EAST. IN STARK CONTRAST TO THE PAST SEVERAL WEEKS...THESE HIGHS WOULD BE VERY NEAR IF NOT SLIGHTLY BELOW NORMAL FOR A CHANGE. THIS EVENING/TONIGHT...THIS IS WHEN LEGITIMATE WIDESPREAD RAINFALL WILL RAMP UP...BUT MAINLY ACROSS THE SOUTHERN 1/2 OF THE CWA. IN SHORT...UPPER DIVERGENCE INCREASES TO THE NORTH OF THE PARENT MID LEVEL LOW...WHICH WILL BE CENTERED GENERALLY OVER THE OK PANHANDLE. IN RESPONSE...A CLASSIC...GENERALLY EAST-WEST BAND OF STEADY SHOWERS AND POSSIBLY SOME EMBEDDED WEAK THUNDERSTORMS WILL GRADUALLY LIFT NORTH ACROSS KS THIS EVENING...AND HAVE POPS PRIOR TO 06Z RANGING FROM ONLY 20 PERCENT NEAR KGRI...TO 90 PERCENT IN MOST OF NORTH CENTRAL KS WHERE THE MAIN PRECIP AXIS WILL SET UP. FOR THE LATE NIGHT PERIOD...THEN HAVE HIGH 70-90 POPS EXPANDING NORTHWARD OUT OF KS INTO MUCH OF SOUTH CENTRAL NEB...BUT MAINLY SOUTH OF I-80. GIVEN TRENDS OF LATEST 06Z NAM...ALONG WITH 4KM WRF-NMM...AM STARTING TO WONDER IF NORTHERN COUNTIES SUCH AS VALLEY/NANCE ETC. WILL SEE MUCH OF ANYTHING BEFORE SUNRISE WED MORNING...AND A TIGHTER POP GRADIENT BETWEEN THE HAVES AND HAVE NOTS MAY PROVE NECESSARY. AS FOR RAINFALL AMOUNTS...EXPECT AT LEAST THE SOUTHERN 1/2 TO 1/3 OF THE CWA TO MEASURE BETWEEN 0.25-0.75 INCH OVERNIGHT...WITH LOCALLY HIGHER AMOUNTS POSSIBLE...AND AGAIN...A FAIRLY SHARP CUTOFF LIKELY SOMEWHERE NEAR I-80. ALTHOUGH CERTAINLY NOT EXPECTING SEVERE WEATHER...WILL KEEP ISOLATED THUNDER MENTION OVERNIGHT MAINLY ACROSS THE SOUTHERN 1/3 OF THE CWA...BUT EVEN SMALL HAIL SHOULD BE HARD TO COME BY. WEDNESDAY...FAIRLY WIDESPREAD RAIN SHOWERS WILL CONTINUE AS THE PARENT MID LEVEL CIRCULATION TRAVERSES EASTWARD NEAR OR JUST SOUTH OF THE KS/OK BORDER. KEPT A BROAD AREA OF LIKELY POPS GOING CWA- WIDE THROUGH THE DAY...ALTHOUGH LATEST NAM/ECWMF CONTINUE TO SUGGEST THAT THE NORTHERN 1/4 OR SO OF THE CWA...GENERALLY NORTH OF HWY 92...COULD STRUGGLE TO SEE MUCH...AND POPS IN THESE AREAS INCLUDING ORD/GREELEY MAY NEED TONED DOWN IN LATER FORECASTS. WITH WIDESPREAD CLOUDS/ONGOING PRECIP...LOWERED HIGH TEMPS 2-4 DEGREES IN MOST AREAS FROM PREVIOUS FORECAST...WITH ONLY LOW-MID 50S MOST AREAS. WEDNESDAY NIGHT...SHOWERS SHOULD GRADUALLY END FROM NORTHWEST- SOUTHEAST AS THE PARENT LOW PROGRESSES TO NEAR THE OK/AR BORDER...AND IT MAY VERY WELL END UP THAT MOST OF THE CWA...ESPECIALLY THE NORTHWEST 1/2...COULD STAY HIGH AND DRY THROUGH THE NIGHT. FOR NOW THOUGH WILL CONTINUE 20-40 POPS CWA-WIDE. THURSDAY...WILL CONTINUE TO KEEP IT DRY...RUNNING WITH THE ASSUMPTION THAT THE DEPARTING SYSTEM SHOULD BE FAR ENOUGH AWAY...ALTHOUGH SUPPOSE A FEW LIGHT WRAP AROUND SHOWERS COULD FLIRT WITH PARTS OF THE KS CWA. WITH AT LEAST PARTIAL SUNSHINE EXPECTED TO RETURN...TEMPS ARE FORECAST TO REBOUND BACK INTO THE LOW-MID 60S FOR HIGHS...BUT AM STAYING JUST BELOW THE MET/MAV GUIDANCE BLEND FOR NOW. AS SURFACE HIGH PRESSURE SLIDES EAST ...EAST-SOUTHEAST WINDS WILL PICK UP A BIT AS THE DAY WEARS ON. THURSDAY NIGHT...WILL ALSO MAINTAIN A DRY FORECAST...ALTHOUGH BOTH THE NAM/GFS ARE DEPICTING CONSIDERABLE LOW LEVEL SATURATION AND POSSIBLE DRIZZLE POTENTIAL MAINLY ACROSS WESTERN NEB/KS...BUT FOR NOW MOST IF NOT ALL OF THIS POTENTIAL LOOKS TO REMAIN WEST OF THE CWA THROUGH THE NIGHT. ALTHOUGH NOT IN THE FORECAST GRIDS AT THIS TIME...SUPPOSE SOME FOG REDUCING VISIBILITY AT LEAST INTO THE 1-2 MILE RANGE IS POSSIBLE ACROSS PARTS OF THE AREA EACH OF THE NEXT 3 NIGHTS...BUT WITH PRECIP GENERALLY EXPECTED TO BE FAIRLY WIDESPREAD AT LEAST THE NEXT 2 NIGHTS...NOT LOOKING LIKE AN OBVIOUS SETUP FOR WIDESPREAD...IMPACTFUL FOG. IN CLOSING...THIS SYSTEM WILL UNDOUBTEDLY BE A BENEFICIAL RAINER IN MANY AREAS...HELPING MAKE UP FOR A MARCH PRECIP DEFICIT. HOWEVER...THERE WILL LIKELY BE A SHARP NORTH-SOUTH RANGE IN RAINFALL AMOUNTS OVER THE NEXT 24-48 HOURS...WITH CURRENT FORECAST GRIDS AIMING FOR TOTALS RANGING FROM AT LEAST 1 TO 1.5 INCHES FOR MOST AREAS NEAR/SOUTH OF I-80...BUT ONLY 0.25-0.50 INCH...AND MAYBE NOT EVEN THAT MUCH...FOR SOME NORTHERN COUNTIES. .LONG TERM...FRIDAY THROUGH MONDAY. BEGINNING ON FRIDAY AN UPPER LOW IS FORECAST TO BE CENTERED IN THE PACIFIC NW WITH TROUGH AXIS EXTENDING THRU THE CENTRAL ROCKIES. IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS...SFC TROUGH DEEPENS ALONG THE HIGH PLAINS. AS SFC GRADIENT TIGHTENS SOUTHERLY WINDS WILL INCREASE WITH BREEZY CONDITIONS SETTING UP BY AFTN AND MOISTURE WILL WORK NORTHWARD WITH DPS RISING DURING THE AFTN. ALTHOUGH MAIN FORCING WILL ARRIVE FRIDAY NIGHT AS UPPER SYSTEM LIFTS ACROSS THE NORTHERN PLAINS AND ASSOCIATED COLD FRONT CROSS OUR REGION...MODELS DO INDICATE SOME THETA E ADVECTION FRIDAY AHEAD OF SYSTEM AND WILL MAINTAIN OUR CURRENT LOW POPS DURING THE DAY FRIDAY. AS FRONT CROSSES FRIDAY NIGHT THERE IS A NARROW AXIS OF INSTABILITY ALONG/AHEAD OF BOUNDARY...MUCAPES NEARING 1000 J/KG...AND COULD POTENTIALLY SEE A STRONG STORM OR TWO. EASTER WEEKEND IS SHAPING UP TO BE DRY AND SEASONAL OVERALL. A 1030MB SURFACE HIGH BUILDS SOUTH BEING THE FRONT AND SETTLES ACROSS THE CENTRAL PLAINS OVERNIGHT. SFC DPS ARE PROGGED TO DROP TO THE TEENS IN OUR NW WITH 20S IN THE SOUTHEAST IN THE DRY AIRMASS. LOOKING LIKE A MUCH COLDER NIGHT THAN WE HAVE HAD RECENTLY HOWEVER NOT NECESSARILY UNUSUAL FOR THIS TIME OF YEAR WITH NORMAL LOWS IN THE LOW/MID 30S. FORECAST LOWS ARE IN THE 30S IN GENERAL AND AGREE PREVIOUS SHIFTS THAT THIS PERIOD WILL NEED TO BE MONITORED FOR FROST/FREEZE POTENTIAL. SURFACE RIDGE AXIS SLIPS SOUTHEAST ON SUNDAY WITH RETURN FLOW SETTING UP DURING THE DAY. ANOTHER COLD FRONT CROSSES THE PLAINS SUNDAY NIGHT/MONDAY ASSOCIATED WITH UPPER LOW IN ONTARIO AND TROUGH EXTENDING ACROSS THE UPPER MIDWEST/OHIO VALLEY REGION. BRUNT OF COLD AIR REMAINS EAST OF THE MISSOURI RIVER...HOWEVER SOME COOLER AIR DOES BACK INTO OUR NORTHEAST COUNTIES. THIS BEING SAID...ALTHOUGH HIGHS MAY DROP A DEGREE OR TWO FROM SUNDAY...TEMPS OVERALL ARE STILL LOOKING SEASONAL OR SLIGHTLY ABOVE. && .PREV DISCUSSION... /ISSUED 1214 AM CDT TUE APR 3 2012/ AVIATION...06Z TAF. THE TAF PERIOD WILL BE MARKED WITH FAIRLY WINDY CONDITIONS IN RESPONSE TO A TIGHT PRESSURE GRADIENT FOLLOWING THE PASSAGE OF A COLD FRONT ON MONDAY. NORTHERLY WINDS WILL AVERAGE 20KTS OR SO AND GUST NEAR 30KTS. WINDS WILL TRANSITION NORTHEASTERLY TUESDAY AFTERNOON AND ALTHOUGH STILL BREEZY...WIND SPEEDS WILL GRADUALLY DECREASE AS THE GRADIENT RELAXES. IT LOOKS LIKE PRECIPITATION WILL HOLD OFF UNTIL BEYOND THE TAF PERIOD UNTIL THE SOUTHERN PLAINS LOW LIFTS FARTHER NORTH. CLOUD COVER FOR THE MOST PART SHOULD BE IN THE MVFR CATEGORY ALTHOUGH SOME IFR CIGS ARE POSSIBLE TUESDAY MORNING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM/AVIATION...CF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1214 AM CDT TUE APR 3 2012 .AVIATION...06Z TAF. THE TAF PERIOD WILL BE MARKED WITH FAIRLY WINDY CONDITIONS IN RESPONSE TO A TIGHT PRESSURE GRADIENT FOLLOWING THE PASSAGE OF A COLD FRONT ON MONDAY. NORTHERLY WINDS WILL AVERAGE 20KTS OR SO AND GUST NEAR 30KTS. WINDS WILL TRANSITION NORTHEASTERLY TUESDAY AFTERNOON AND ALTHOUGH STILL BREEZY...WIND SPEEDS WILL GRADUALLY DECREASE AS THE GRADIENT RELAXES. IT LOOKS LIKE PRECIPITATION WILL HOLD OFF UNTIL BEYOND THE TAF PERIOD UNTIL THE SOUTHERN PLAINS LOW LIFTS FARTHER NORTH. CLOUD COVER FOR THE MOST PART SHOULD BE IN THE MVFR CATEGORY ALTHOUGH SOME IFR CIGS ARE POSSIBLE TUESDAY MORNING. && .PREV DISCUSSION... /ISSUED 1100 PM CDT MON APR 2 2012/ UPDATE...UPDATED THE FORECAST TO INCREASE POPS IN THE SOUTHWEST AND PUT IN SOME DRIZZLE IN THE NORTHEAST. THE NAM AND OBSERVATIONS TO THE NORTH SUPPORT THIS. INCREASED SKY COVER TO CLOUDY FOR OVERNIGHT. PREV DISCUSSION... /ISSUED 346 PM CDT MON APR 2 2012/ SHORT TERM...TONIGHT AND TUESDAY. MAIN FORECAST CONCERN WILL BE CHANCE FOR SHOWERS AND THUNDERSTORMS. SURFACE ANALYSIS AND SURFACE OBSERVATIONS INDICATE A COLD FRONT ACROSS THE EASTERN PART OF THE FORECAST AREA THIS AFTERNOON. AHEAD OF THE COLD FRONT TEMPERATURES HAVE JUMPED AND ARE QUITE WARM. COOLER TEMPERATURES ARE BEHIND THE FRONT. SATELLITE SHOWS SOME STRATUS ACROSS THE FAR NORTHERN PART OF THE FORECAST AREA. THIS WAS SPREADING FURTHER SOUTH THIS MORNING...BUT HAS HELD OFF DURING THE AFTERNOON. WINDS HAVE FINALLY STARTED TO INCREASE TO THE WEST AND WILL CONTINUE TO INCREASE THIS AFTERNOON FOR THE FAR WEST. WILL LEAVE THE WIND ADVISORY AS IS. THE POSITION OF THE FRONT IS KEY THIS AFTERNOON FOR THUNDERSTORM DEVELOPMENT. MODELS HAVE THUNDERSTORMS DEVELOPING ALONG THE FRONT DURING THE LATE AFTERNOON AND EARLY EVENING. WITH THE CURRENT LOCATION OF THE FRONT EXPECT THUNDERSTORMS TO BE IN THE SOUTHEAST PART OF THE FORECAST AREA. THE HRRR KEEPS THE PRECIPITATION IN THE FAR SOUTHEAST THROUGH THE EVENING WHILE THE NAM AND GFS HAVE IT A BIT FURTHER TO THE NORTHWEST. THE BEST MUCAPES ARE IN THE FAR SOUTHEAST PART OF THE FORECAST AREA WITH THE OVER 1000J/KG CAPES FAR IN THE SOUTHEASTERN PART OF THE FORECAST AREA. LATER THIS EVENING AND OVERNIGHT AN UPPER LEVEL LOW DEVELOPING ON THE SOUTHERN HIGH PLAINS STARTS TO DRIFT TO THE NORTH AND PUSHES PRECIPITATION TO THE NORTH BEHIND THE FRONT. MOST OF THE PRECIPITATION SHOULD BE IN THE SOUTHERN PART OF THE FORECAST AREA. THE UPPER LEVEL LOW CONTINUES TO DRIFT THROUGH THE SOUTHERN HIGH PLAINS ON TUESDAY AND THE CHANCE FOR SHOWERS CONTINUES MAINLY IN THE SOUTH/SOUTHWEST. LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH PRECIPITATION CHANCES EARLY ON IN THE PERIOD. LOOKING AT THE TIME FRAME STARTING TUESDAY NIGHT AND CONTINUING THROUGH WEDNESDAY NIGHT...THE MAIN STORY LIES WITH THE IMPACT ACROSS THE REGION FROM A PASSING UPPER LEVEL LOW PRESSURE SYSTEM AND ASSOCIATED PRECIPITATION CHANCES. LATEST MODELS RUNS ARE IN PRETTY GOOD AGREEMENT AT THE START OF THE PERIOD...SHOWING THE LOW CENTERED OVER THE PANHANDLES OF TX/OK...BUT MORE VARIANCES START TO SHOW UP THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY. THE SYSTEM DOESNT MAKE A WHOLE LOT OF EASTWARD PROGRESS...WITH A RIDGE AXIS TO THE EAST EXTENDING FROM THE GULF COAST REGION UP INTO THE ERN DAKOTAS...AND BY WEDNESDAY EVENING LOOKS TO RANGE IN LOCATION FROM SC KS TO WRN OK. INCREASED LIFT OUT AHEAD OF THE LOW PRESSURE SYSTEM WILL HELP WITH THE NORTHWARD SPREAD OF PRECIPITATION FROM THE SRN PLAINS INTO THE CWA TUESDAY EVENING/OVERNIGHT...WHICH WILL CONTINUE ON INTO THE DAYTIME HOURS ON WEDNESDAY AS INCREASED LOW/MID LEVEL FRONTOGENETICAL ON THE NORTHERN SIDE OF THE LOW SHIFTS INTO THE CWA. DECIDED TO INSERT A MENTION OF ISOLATED THUNDER WED EVENING...WITH SOME OF THE MODELS/SREF PROBS SHOWING THE POTENTIAL LINGERING AROUND THE SOUTHEASTERN CORNER OF THE CWA. EXPECTING PLENTY OF CLOUD COVER AND GENERALLY N/NE WINDS AS THE MAIN SFC LOW SLIDES TO THE SOUTH OF THE CWA...WITH HIGHS TOPPING OUT IN THE LOW/MID 50S. MODELS ARE A LITTLE SLOWER THURSDAY EVENING/NIGHT PUSHING PRECIPITATION CHANCES EAST OF THE CWA AS THE UPPER LEVEL LOW MAKES ITS WAY TOWARD THE MO RIVER...AND PUSHED POPS BACK WEST TO INCLUDE ALL COUNTIES. UPPER LEVEL SHORTWAVE RIDGING BUILDING INTO THE PLAINS IN THE WAKE OF THIS LATEST SYSTEM IS EXPECTED TO KEEP THURSDAY AND THURSDAY NIGHT DRY. SEE A SLIGHT BUMP IN HIGHS BUT TEMPS REMAIN ON THE RELATIVELY COOL SIDE /COMPARED TO THE LAST FEW DAYS...BUT STILL NEAR OR ABOVE AVG/...WITH THE CWA REMAINING ON THE WRN/SRN FRINGE OF SFC HIGH PRESSURE OVER THE WRN GREAT LAKES...AND AM EXPECTING LOWER 60S. NEXT CHANCE FOR PRECIPITATION IS EXPECTED TO COME TO WESTERN PORTIONS OF THE CWA DURING THE DAY ON FRIDAY AND EXPAND FURTHER EAST FRIDAY NIGHT...AS ANOTHER SHORTWAVE TROUGH AXIS LOOKS TO SWING THROUGH THE NORTHERN/CENTRAL PLAINS. MODELS VARY SOME THROUGH THIS TIMEFRAME...WITH THE GFS SHOWING THIS ENERGY ASSOCIATED WITH AN ELONGATED LOW OVER WRN/CENTRAL CANADA...WHILE THE EC SHOWS ANY LOW LOCATED OFF THE PAC NW COAST. KEPT THE HIGHER POPS ACROSS THE NORTH WHERE THERE IS BETTER AGREEMENT BETWEEN THE MODELS...BUT POPS GO ALL THE WAY SOUTH TROUGH THE CWA WITH THE GFS CONTINUING TO SHOW MORE COVERAGE. THE MAIN INSTABILITY AXIS LOOKS TO SET UP JUST WEST OF THE CWA DURING THE DAY...AND PUSH THROUGH DURING THE OVERNIGHT HOURS...WITH MUCAPE VALUES UPWARDS OF 7-800 J/KG...SO THREAT OF SOME STRONG STORMS WILL REMAIN...BUT WILL CONTINUE TO KEEP AN EYE ON THE POTENTIAL FOR SEVERE STORMS. KEPT THE FORECAST FOR THE UPCOMING WEEKEND AND INTO MONDAY DRY...THOUGH THE GFS TRIES TO LINGER SOME POPS IN THE EAST EARLY ON SAT MORNING. AN ACCOMPANYING SURFACE COLD FRONT IS EXPECTED TO BE ON ITS WAY THROUGH THE CWA SATURDAY MORNING...BUT MODELS DO VARY SOME ON THE TIMING. EC IS ON THE QUICKER SIDE...WITH THE FRONT CLEARING THE CWA SAT MORNING...WHILE THE GFS WOULD BE MORE INTO THE AFTERNOON. LOOKS TO BE BREEZY DAY ON SATURDAY...WITH NORTHWEST WINDS PICKING UP BEHIND THE FRONT. MORE ZONAL/NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS FOR SUN/MON WITH A RIDGE SET UP OVER THE SRN/SWRN CONUS...WITH NO NOTABLE SYSTEM LOOKING TO PASS THROUGH. BEHIND THE SFC FRONT...HIGH PRESSURE BUILDS IN AND IS THE DOMINANT FEATURE ON SUNDAY...BRINGING A PLEASANT WITH LIGHT WINDS AND HIGHS TOPPING OUT IN THE LOWER/MID 60S. MONDAY COULD SEE AN INCREASE IN WINDS DEPENDING ON THE MODEL...BUT STILL EXPECTING ANOTHER NICE DAY WITH HIGHS SIMILAR TO SUNDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1150 PM CDT MON APR 2 2012 .AVIATION... 06Z TAFS FOR KOMA...KLNK...AND KOFK. MVFR CIGS HAVE REACHED KOFK AND KLNK...AND SHOULD REACH KOMA BETWEEN 06-08Z. KEPT KOFK CIGS JUST ON THE LOW END OF MVFR...THOUGH WOULD NOT BE SURPRISED BY A DIP INTO HIGHER-END IFR OVERNIGHT. MVFR CIGS SHOULD LAST THROUGH AROUND MIDDAY...BEFORE LIFTING INTO VFR RANGE...BUT ALL SITES SHOULD KEEP AT LEAST VFR CIGS THROUGH MUCH OF THE TAF PERIOD. GUSTY NORTHWEST WINDS WILL VEER TO NORTHEASTERLY THROUGH THE DAY...REMAINING GUSTY THROUGH THE TAF CYCLE. MAYES && .PREV DISCUSSION... /ISSUED 927 PM CDT MON APR 2 2012/ DISCUSSION... UPDATED THE FORECAST FOR SKY...POP/WEATHER...AND TEMPERATURE TRENDS THIS EVENING. OVERCAST STRATUS DECK HAS ENCROACHED INTO NORTHWEST CWA...AND RUC/NAM/HRRR PROGS INDICATE IT WILL OVERSPREAD MUCH OF EASTERN NEB INTO WESTERN IA THROUGH THE EVENING AND OVERNIGHT HOURS...WITH CLOUDS LINGERING THROUGH MUCH OR ALL OF TOMORROW AS WELL. HAVE BUMPED CLOUDS TO OVERCAST/CLOUDY COVERAGE THROUGH AT LEAST MIDDAY TOMORROW. PRECIP HAS REMAINED MAINLY SOUTH AND WEST OF THE CWA...WITH JUST A FEW SHOWERS POPPING UP ALONG AND BEHIND THE FRONT. HAVE UPDATED THE FORECAST TO MENTION JUST ISOLATED SHOWERS FOR THE NEXT HOUR OR SO...WITH NO MEASURABLE PRECIP FOR THE REST OF THE NIGHT. ALSO REMOVED MEASURABLE PRECIP FROM THE NORTHWEST CWA AND ADDED DRIZZLE...AS KLBF RADAR HAS A DRIZZLE APPEARANCE WITH LIGHT PRECIP ON THE KONL OB. FINALLY...WITH TEMPERATURES DROPPING ABRUPTLY BEHIND THE FRONT...HAVE UPDATED THE TEMPERATURE TREND FOR A SHARP DROPOFF IMMEDIATELY BEHIND THE FRONT...WITH A SLOWER DROPOFF THROUGH THE REST OF THE NIGHT AS CLOUDS INCREASE AND GUSTY WINDS CONTINUE. MAYES PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... THE SHORT TERM CONCERNS WILL BE THE POTENTIAL FOR THUNDERSTORMS AND SEVERE WEATHER AND IF A WIND ADVISORY WILL BE NEEDED. AT 20Z...THE COLD FRONT HAD FINALLY MADE IT INTO NORFOLK AND THEIR TEMPERATURES WERE BEGINNING TO FALL. AHEAD OF THE FRONT...TEMPERATURES TOPPED OUT IN THE 80S TO LOWER 90S. THE LOW CLOUDS HAD MADE IT INTO THE THE ONEILL AREA AND TEMPERATURES WERE ONLY IN THE 50S. WINDS IN THE WEST CENTRAL PART OF NEBRASKA WERE QUITE STRONG WITH GUSTS IN THE 40 TO 50 MPH IN SPOTS. TONIGHT...THE SURFACE COLD FRONT WILL BE MOVING ACROSS THE REST OF EASTERN NEBRASKA AND SOUTHWEST IOWA. THE HIGHER UPPER 50S AND LOWER 60S DEGREE DEWPOINTS AT 20Z EXTENDED FROM BEATRICE TO OMAHA AND THESE WILL SHIFT EASTWARD WITH TIME. THE 4KM WRF HAD THUNDERSTORMS ALONG THE FRONT...WHILE THE 18Z NAM WAS DRY...THE LATEST RUC HAD SOME STORMS DEVELOPING TOWARD FAIRBURY AND THE GFS HAD AN AREA SIMILAR TO THE 4KM WRF...BUT SHIFTED FARTHER SOUTHEAST AND MAINLY ALONG AND SOUTH OF I80. THERE IS THE POTENTIAL FOR THUNDERSTORMS THIS EVENING AHEAD OF AND ALONG THE FRONT AND WILL MAINTAIN ISOLATED TO SCATTERED THUNDERSTORM CHANCES MAINLY ALONG AND SOUTH OF I80. THE ATMOSPHERE HAS GOOD INSTABILITY AND STEEP LAPSE RATES TO WORK WITH...HOWEVER THE SHEAR PARAMETERS DO NOT APPEAR AS FAVORABLE IN THIS AREA. SPC HAS A SLIGHT RISK AND THE SLIGHT RISK APPEARS WARRANTED BASED ON CONDITIONAL FACTORS AS SHOULD THUNDERSTORMS GET GOING THEY COULD CONTAIN SOME HAIL AND DAMAGING WINDS. BEHIND THE FRONT...ESPECIALLY ACROSS NORTHEAST NEBRASKA THE WINDS WILL BE STRONG. AT THIS TIME WILL HAVE WINDY CONDITIONS AT 20 TO 30 MPH WITH GUSTS TO 45...BUT HAVE NOT GONE WITH A WIND ADVISORY AT THIS TIME. BEHIND THE FRONT...WITH THE LOW CLOUDS THERE MAY BE SOME SHOWERS IN NORTHEAST NEBRASKA AND SOME OF THESE MAY LINGER INTO TUESDAY. THE SOUTHERN ENERGY WITH THIS STORM SYSTEM WILL CLOSE OFF AND LIFT NORTH. THIS WILL RETURN THE CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY AND WEDNESDAY NIGHT AND THEN MOVE OUT THURSDAY. THURSDAY NIGHT THROUGH MONDAY....THE STORM SYSTEM THAT WILL AFFECT US FOR MUCH OF THE WEEK WILL BE OVER SOUTHERN MISSOURI AT THE START OF THE EXTENDED WITH DRY CONDITIONS...SOUTHEAST BREEZES AND COMFORTABLE TEMPERATURES IN THE 60S FRIDAY. FRIDAY NIGHT...THE TROF OVER THE PACIFIC NORTHWEST WILL PUSH FAR ENOUGH EASTWARD TO PUSH TO FRONT INTO PARTS OF EASTERN NEBRASKA BY 12Z SATURDAY. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF AND ALONG THE COLD FRONT FRIDAY NIGHT AND SATURDAY. AS THIS SYSTEM MOVES OUT OF THE AREA...MID LEVEL RIDGING BUILDS IN AND DRY WEATHER AND MORE SEASONABLE WEATHER IS FORECAST FOR SATURDAY AND SUNDAY. ZAPOTOCNY && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
135 AM EDT TUE APR 3 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT THROUGH EARLY TUESDAY BEFORE IT MOVES OFFSHORE. A FRONT WILL RETURN NORTH AS A WARM FRONT ON TUESDAY. ANOTHER COLD FRONT WILL TRACK SOUTH THROUGH THE AREA WEDNESDAY NIGHT INTO THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR FRIDAY NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN ACROSS THE SOUTHEAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1040 PM MONDAY...THE LEADING EDGE OF THE NE-E SURGE IS NOW WEST AND SOUTH OF THE ILM CWA. THIS SURGE AT THIS TIME BEST ILLUSTRATED WITH 11-3.9 MICRON SAT IMAGERY TRENDS OVERLAID WITH LAPS SFC WIND FIELDS. LOOK FOR A MUCH MORE STABLE...COOLER AND DRIER AIR MASS TO OVERSPREAD THE ILM CWA. THE COOLER AND DRIER PORTIONS OF THIS AIR MASS WILL LIE ACROSS THE NE PORTIONS OF THE ILM CWA. WITH THE SFC FRONT STALLING ALONG THE SAVANNAH RIVER VALLEY...A SHALLOWER COOL/DRY AIR MASS CHANGE WILL LIE ACROSS THE SC PORTIONS OF THE ILM CWA. THIS HAS RESULTED IN LOWER MINS BEING FORECAST ACROSS THE ILM NC CWA...WITH ILM SC LOWS AS MUCH AS 4 TO 8 DEGREES HIER THEN THE ILM NC CWA. NULL POPS FOR THE REMAINDER OF THE OVERNIGHT. NAMBUFR SOUNDINGS FOR TONIGHT INDICATE POSSIBLE POST FRONTAL FEW TO SCT SC MAINLY FOR THE ILM SC CWA...BUT FOR THE MOST PART WILL STICK WITH A CLEAR/MOSTLY CLEAR SKY CONDITION. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...BACKDOOR COLD FRONT OFF TO THE SOUTH WILL ALLOW RIDGE OF HIGH PRESSURE TO NOSE INTO THE CAROLINAS FROM THE NORTH EARLY TUESDAY. THIS AIRMASS WILL QUICKLY SLIDE OFF THE COAST BY AFTERNOON. SOME MOISTURE RETURN WILL BE ENSUE FROM WEST TO EAST ACROSS THE CAROLINAS. IN THE UPPER LEVELS A SHORT AMPLITUDE RIDGE WILL HOLD ON FOR THE MOST PART. MODELS STRUGGLING WITH SOME CONVECTIVELY INDUCED VORT CENTERS EMANATING FROM TEXAS...AND DEEPENING ON THE TRACK AND STRENGTH OF THESE FEATURES THEY MAY BE ABLE TO SERVE AS SOME WEAK FORCING LOCALLY. BARRING THIS POSSIBILITY MOST OF THE AREA LOOKS TO REMAIN RAIN-FREE WITH NEAR SEASONABLE TEMPERATURES. ADVECTION OF WARMTH AND MOISTURE WILL CONTINUE FOR THE REMAINDER OF THE PERIOD KEEPING TUESDAY NIGHT VERY MILD ESPECIALLY DUE TO THE INCREASED CLOUD COVER. THE UPPER RIDGE WILL CONTINUE TO BE WEAKENED ON WEDNESDAY ALLOWING CLEARER PASSAGE OF SOME WEAK VORTICITY CENTERS. A PREFRONTAL PIEDMONT TROUGH WILL TEND TO FOCUS MOST OF THE SCATTERED CONVECTION OVER WESTERN ZONES INITIALLY. HOWEVER SINCE STORMS WILL HAVE A WELL DEFINED EASTWARD MOTION THERE WILL BE ONLY A SLIGHT GRADIENT IN FCST POPS AT THIS TIME. QPF WILL BE HIGHER OVER WRN ZONES (ALTHOUGH STILL QUITE LOW). DESPITE THE CLOUD COVER MOST PLACES SHOULD HAVE NO TROUBLE SEEING A HIGH IN THE LOW 80S. COLD FRONT ARRIVES LATE WEDNESDAY NIGHT AND LOOKS QUITE MOISTURE-CHALLENGED. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...PROGRESSIVE PATTERN WILL PREVAIL THROUGH THE EXTENDED AS A MID LEVEL CYCLONE MOVES ACROSS EARLY FOLLOWED BY BRIEF RIDGING. FINALLY...AT THE END OF THE PERIOD SUBTLE TROUGHING WILL MOVE ACROSS. THE FORECAST CHALLENGES CONTINUE TO CENTER AROUND TIMING AND MAGNITUDE FOR FRIDAY TRANSITIONING TO A TEMPERATURE FORECAST FOR THE WEEKEND. STILL SOME UNCERTAINTY WITH REGARDS TO THE CHARACTERISTIC OF THE SYSTEM FRIDAY AS THE LATEST GFS...AND PAST COUPLE OF CYCLES FOR THAT MATTER SHOW A CLOSED MID LEVEL CYCLONE MOVING ACROSS THE UPSTATE OF SOUTH CAROLINA THEN OPENING UP AND MOVING OFF QUICKLY. THE ECMWF AND ENSEMBLES ARE SIMILAR BUT A BIT FURTHER SOUTH. I HAVE INCREASED POPS TO LIKELY FOR FRIDAY MATCHING HPC AND INCREASED POPS INTO SATURDAY MORNING TO ADDRESS SLOWER TIMING WITH A SYSTEM THAT REMAINS CLOSED FOR A LONGER PERIOD OF TIME. TEMPERATURES DROP TO JUST BELOW CLIMATOLOGY SATURDAY AND SUNDAY BEFORE REBOUNDING QUICKLY WITH A SOUTHWEST FLOW MONDAY. SUNDAY SHOULD BE THE COOLEST MORNING COUPLED WITH THE BEST RADIATIONAL CONDITIONS WITH MID TO UPPER 40S CWA WIDE. SOME CLIMATOLOGICALLY FAVORED AREAS COULD SEE A DEGREE OR TWO BELOW 45. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...LIGHT SHOWERS ARE EXPECTED TO REMAIN W AND S OF THE TERMINALS THROUGH SUNRISE. DRIER AIR WILL CONTINUE TO PUSH DEWPOINTS LOWER WITH DRIEST OF AIR AT LBT AND ILM. FRONT HAS STALLED AND BECOME RATHER DIFFUSE AND WITH THAT...SOME MID CLOUDS WILL SPILL BACK N ACROSS FLO AND PERHAPS MYR THROUGH SUNRISE. CONTINUED VFR AFTER SUNRISE WITH VEERING WINDS TO THE SOUTHEAST BY AFTERNOON. ISOLATED CONVECTION IS POSSIBLE...MAINLY AFTER 00Z AT FLO AND MYR AS WARM FRONT PUSHES ACROSS THE AREA. EXTENDED OUTLOOK...MODERATE CONFIDENCE ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS WITH TEMPO MVFR WEDNESDAY THROUGH THURSDAY NIGHT. A GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS WITH WIDESPREAD IFR FRIDAY. VFR SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1040 PM MONDAY...POST FRONTAL NE-E SURGE ACCOMPANIED BY COLD AIR ADVECTION HAS PUSHED SOUTH OF THE ILM WATERS...AND IS PROGGED TO STALL IN THE VICINITY OF THE MOUTH OF THE SAVANNAH RIVER OVERNIGHT INTO TUESDAY. CURRENT BUOY OBS AND HRRR WIND OUTPUT INDICATE SPEEDS OF AROUND 15 KT FOR THE REMAINDER OF THE NIGHT...POSSIBLY DOWN TO 10-15 KT NORTH OF CAPE FEAR WHERE GRADIENT WILL RELAX SOME AND THE POST FRONTAL CAA SURGE ENDS. LOOK FOR SEAS IN THE 2 TO 4 FT RANGE THRUOUT. THE EXCEPTION WILL BE UP TO 5 FT ACROSS THE WATERS OFF CAPE FEAR THROUGH MIDNIGHT. SEAS PRIMARILY A REFLECTION OF SHORT PERIOD WIND DRIVEN WAVES RUNNING AT 4-5 SECOND PERIODS...ACCOMPANIED BY AN UNDERLYING AND WEAK 1 FT OR LESS EASTERLY GROUND SWELL AT A 10 SECOND PERIOD. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...NORTHEAST WINDS ON TUESDAY WITH A BACKDOOR FRONT OFF TO THE SOUTH AND HIGH PRESSURE BUILDING IN FROM THE NORTH EARLY TUESDAY. THIS HIGH WILL MOVE OFF THE COAST BY AFTERNOON BRINGING VEERING AND PERHAPS DECREASING WINDS. VEERING CONTINUES TUESDAY NIGHT BRINGING A MORE DEFINED SOUTHERLY COMPONENT. NO REAL SWELL ENERGY ON THE RADAR SO SEAS GENERALLY 2 TO 3 FT THROUGHOUT. WEDNESDAY BRINGS A PREFRONTAL SOUTHWESTERLY FLOW REGIME WITH A TIGHTENING GRADIENT. THIS SHOULD ADD ABOUT A FOOT TO THE PREDOMINANT WAVE HEIGHT. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...NORTHEAST FLOW INITIALLY WILL VEER A BIT TO MORE TO AN EASTERLY DIRECTION EARLY FRIDAY AS LOW PRESSURE DROPS WELL TO THE SOUTH. STILL SOME UNCERTAINTY OF THE EXACT TIMING AND PLACEMENT OF THE SYSTEM SO WE COULD SEE WINDS VEER EVEN MORE THROUGH FRIDAY THAN THE CURRENT FORECAST ADVERTISES. NORTHEASTERLY FLOW LATE FRIDAY THROUGH SATURDAY AS HIGH PRESSURE BUILDS IN BEHIND THE SYSTEM. AS USUAL SURGES ARE DIFFICULT TO TIME BUT SHOULD SEE SEVERAL HOURS OF SPEEDS NEAR 20 KNOTS ACROSS THE OUTER WATERS. WAVEWATCH SEAS INCREASE FROM 2-4 FEET EARLY TO 4-7 FEET LATE IN THE PERIOD WITH THE STRONGER FETCH. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...HOEHLER SHORT TERM...BACON LONG TERM...KEEBLER AVIATION...RJD/DL
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
357 AM CDT TUE APR 3 2012 .SHORT TERM... POTENT UPPER LOW OVER NEW MEXICO WILL SLOWLY MOVE EAST INTO THE TEXAS HANDLE TONIGHT. PACIFIC FRONT HAS PUSHED EAST OF A JUNCTION... BRADY... ABILENE...HASKELL LINE. IT WAS STILL UNSTABLE ALONG AND AHEAD OF THE FRONT WITH RUC MUCAPES OF 2000 J/KG AND 0-6 KM SHEARS OF 40 KTS. CAN NOT RULE OUT AN ISOLATED SEVERE THUNDERSTORMS EAST OF THE PACIFIC FRONT THIS MORNING. HOWEVER...DRIER WESTERLY AIR AT THIS SURFACE WILL WORK EASTWARD BY NOON...ENDING THE SEVERE THREAT. THERE AS OUTSIDE CHANCE OF A SHOWER...AS 700 MB MOISTURE WAS WRAPPED AROUND THE UPPER THIS MORNING ACROSS WEST TEXAS. THIS IS EXPECTED TO MOVE NORTH OF THE REGION BY EARLY AFTERNOON. OTHERWISE...DRY DESERT AIR AT THE SURFACE WILL BE GUSTY AT TIMES THIS AFTERNOON...ELEVATING FIRE WEATHER CONDITIONS. .LONG TERM... GUSTY WEST WINDS WILL AGAIN ELEVATE FIRE CONDITIONS WEDNESDAY AS SURFACE LOW IN NW TEXAS MOVES NE INTO CENTRAL OKLAHOMA. COOL AIR FILTERS IN WEDNESDAY NIGHT AS A WEAK COLD FRONT MOVES INTO THE REGION. LATER THIS WEEK...THERE IS STILL THE POTENTIAL FOR DRYLINE THUNDERSTORMS FRIDAY NIGHT. A COLD FRONT SATURDAY WILL ALSO BRING A CHANCE FOR THUNDERSTORMS...MAINLY SOUTH OF THE I-20 CORRIDOR. ADDED SLIGHT CHANCE OF STORMS SATURDAY NIGHT AND SUNDAY WITH LIFT OF MOISTURE OVER THE FRONT. CONFIDENCE REMAINS LOW HOWEVER SO KEPT POPS AT 20 PERCENT. .FIRE WEATHER. GUSTY DRY WEST WINDS WILL ELEVATED FIRE DANGER THIS AFTERNOON AND WEDNESDAY AFTERNOON...AS A SURFACE LOW IN NW TEXAS MOVES INTO CENTRAL OKLAHOMA. WINDS SPEEDS ARE EXPECTED TO REMAIN BELOW CRITICAL LEVELS. 04 && .PRELIMINARY POINT TEMPS/POPS... ABILENE 79 50 81 49 83 / 10 10 0 0 0 SAN ANGELO 84 47 85 49 90 / 10 10 0 0 0 JUNCTION 81 46 87 48 91 / 20 10 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/04
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1151 PM CDT MON APR 2 2012 .UPDATE... HOISTED A WIND ADVISORY FOR THE WESTERN AND CENTRAL OK PANHANDLE AND NORTHWEST TX PANHANDLE THROUGH 09Z. COLD FRONT FINALLY STARTING TO SURGE SOUTH THROUGH THESE AREAS...WITH TIGHT GRADIENT NORTHWEST OF SURFACE LOW OVER TX PANHANDLE SUPPORTING ADVISORY LEVEL WINDS. BELIEVE THE TIGHTEST GRADIENT WILL REMAIN FOCUSED ACROSS THIS NORTHWEST PORTION OF THE CWA AND THUS WILL KEEP ADVISORY CONFINED TO THIS AREA FOR NOW. SEVERE WEATHER THREAT HAS ENDED ACROSS THE AREA BUT WILL CONTINUE TO SEE SHOWER AND THUNDERSTORM CHANCES OVERNIGHT...AND COULD SEE SOME LIGHT SNOW IN THE FAR NORTHWEST CWA /AS IS CURRENTLY BEING REPORTED AT CLAYTON NM/. EXPECT SNOW ACCUMULATIONS...IF ANY...TO BE VERY LIGHT. BEST PRECIP CHANCES WILL BE ACROSS THE NORTH/NORTHWEST CWA FOR THE REST OF TONIGHT WHERE MID/UPPER FORCING WILL MEET UP WITH BETTER MOISTURE ALONG AND NORTH OF THE COLD FRONT. KB && .PREV DISCUSSION... /ISSUED 1142 PM CDT MON APR 2 2012/ AVIATION... CLOSED UPPER LOW OVER EASTERN NEW MEXICO TONIGHT ALONG WITH A COLD FRONT WILL ALLOW FOR MAINLY SHOWERS AT THE DALHART AND GUYMON TAF SITES THROUGH ABOUT 00Z TO 03Z WEDNESDAY. LEFT ANY MENTION OF SHOWERS OUT OF THE AMARILLO TAF SITE DUE TO LOW CONFIDENCE...HOWEVER NOT RULING OUT COMPLETELY. NORTHERLY WINDS WILL BE STRONG INITIALLY AT THE DALHART AND GUYMON TAF SITES...AROUND 25 TO 35 KNOTS SUSTAINED WITH HIGHER GUSTS...BUT SHOULD DIMINISH TO AROUND 15 TO 25 KNOTS BY 15Z TUESDAY AND CONTINUING THROUGH 06Z WEDNESDAY. WINDS ARE EXPECTED TO SHIFT TO THE NORTH APPROXIMATELY 06Z TUESDAY WITH SPEEDS ONLY ABOUT 10 TO 20 KNOTS WITH SOME HIGHER GUSTS POSSIBLE. SCHNEIDER PREV DISCUSSION... /ISSUED 936 PM CDT MON APR 2 2012/ UPDATE... HAVE EXTENDED THE WIND ADVISORY ACROSS CIMARRON COUNTY THROUGH MIDNIGHT...AND ALLOWED IT TO EXPIRE FOR DALLAM AND HARTLEY COUNTIES. LATEST OBSERVATIONAL AND SHORT-RANGE MODEL DATA SHOW A TIGHT LOW- LEVEL PRESSURE GRADIENT/REINFORCING SURGE OF NORTH/NORTHEAST WINDS TO IMPACT THE WESTERN OK PANHANDLE OVER THE NEXT FEW HOURS. RECENT OBS FROM KENTON...BOISE CITY...AND SPRINGFIELD CONTINUE TO SHOW ADVISORY LEVEL WINDS...AND KENTON JUST BRIEFLY HIT HIGH WIND WARNING CRITERIA. LET THE RED FLAG WARNING ACROSS THE SOUTHWEST/SOUTH CENTRAL TX PANHANDLE EXPIRE AS SCHEDULED AT 9 PM. WINDS HAVE DIMINISHED TO LESS THAN 20 MPH AND RELATIVE HUMIDITIES WILL CONTINUE TO INCREASE OVERNIGHT. ALSO ADJUSTED PRECIP CHANCES FOR THE REST OF TONIGHT BASED ON LATEST RADAR TRENDS. LINE OF CONVECTION RAPIDLY DEVELOPED AS PACIFIC COLD FRONT OVERTOOK DRYLINE. THIS LINE OF SEVERE CONVECTION WILL CONTINUE TO PIVOT NORTHEAST AHEAD OF POTENT MID-LEVEL VORT MAX ROUNDING CLOSED LOW OVER NM. MAIN FOCUS FOR PRECIPITATION EXPECTED TO SET UP OVER THE NORTHERN CWA AFTER MIDNIGHT AS VORT LOBE CONTINUES TO PIVOT NORTH AND EVENTUALLY NORTHWEST. SEVERE THREAT WILL LINGER THE LONGEST ACROSS THE NORTHEAST TX PANHANDLE AND EASTERN HALF OF THE OK PANHANDLE...BUT WILL EVENTUALLY DIMINISH THERE AS WELL LATER TONIGHT AS PACIFIC FRONT CONTINUES TO PUSH EAST AND STATIONARY FRONT ACROSS NORTHERN CWA EVENTUALLY PUSHES SOUTHEAST...SQUEEZING THE DEEPER LOW-LEVEL MOISTURE AND ASSOCIATED INSTABILITY EASTWARD. KB PREV DISCUSSION... /ISSUED 634 PM CDT MON APR 2 2012/ UPDATE... EXPANDED SEVERE THUNDERSTORM WATCH ONE TIER OF COUNTIES WESTWARD. SURFACE FRONT DRAPED SOUTH/SOUTHWEST ACROSS THE EASTERN OK AND NORTHEAST TEXAS PANHANDLE...AND DRYLINE EXTENDING SOUTH FROM THE FRONT ACROSS THE EASTERN TX PANHANDLE...WERE RETREATING TO THE WEST AND NORTHWEST IN RESPONSE TO SURFACE LOW DEVELOPING NORTHEAST INTO THE TX PANHANDLE AHEAD OF STRONG MID-LEVEL VORT MAX PIVOTING AROUND CLOSED MID/UPPER-LEVEL LOW OVER NM. LATEST RUC GUIDANCE SHOWS THIS BOUNDARY WILL CONTINUE TO RETREAT A LITTLE FARTHER EARLY THIS EVENING...BEFORE DRYLINE ACROSS SOUTHEAST TX PANHANDLE GETS OVERTAKEN BY PACIFIC FRONT AND SHOVED EASTWARD. KB PREV DISCUSSION... /ISSUED 625 PM CDT MON APR 2 2012/ UPDATE... CONVECTION WILL CONTINUE TO DEVELOP IN RESPONSE TO A COLD FRONT ACROSS THE PANHANDLES AND APPROACHING UPPER LOW FROM NEW MEXICO. THIS CONVECTION WILL AFFECT ALL OF THE TAF SITES THROUGH 10Z TUESDAY. VFR CONDITIONS WILL PREVAIL EXCEPT MVFR TO POSSIBLY IFR CONDITIONS IN AND NEAR THE CONVECTION. WINDS WILL BECOME NORTHERLY TO NORTHEASTERLY 15 AND 20 TO 25 AND 30 KNOTS WITH HIGHER GUSTS BEHIND THE COLD FRONT...WITH SOUTHERLY TO SOUTHWESTERLY WINDS AHEAD OF THE FRONT MAINLY THIS EVENING AT THE AMARILLO TAF SITE. SCHNEIDER PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... UPPER LEVEL LOW HAS CUTOFF FROM THE FLOW OVER CENTRAL NEW MEXICO. THIS LOW IS EXPECTED TO SLOWLY LIFT NORTHEAST THROUGH NORTHEAST NEW MEXICO AND ACROSS THE NORTHWEST PART OF OUR CWA INTO SOUTHWEST KANSAS BY WEDNESDAY AFTERNOON. A SURFACE COLD FRONT HAS STALLED NEAR THE CANADIAN RIVER VALLEY THIS AFTERNOON. THIS FRONT MAY LIFT BACK TO THE NORTH BRIEFLY THIS EVENING BEFORE MOVE SOUTHEAST AGAIN LATER TONIGHT. THE COLD FRONT WILL THEN STALL AGAIN BY TUESDAY AFTERNOON ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE BEFORE MOVING SOUTH OF THE TEXAS PANHANDLE BY TUESDAY EVENING. WILL KEEP THE NORTHWEST CWA UNDER A WIND ADVISORY THROUGH THE MID EVENING AS WINDS ARE EXPECTED TO PICK UP AGAIN BY EARLY THIS EVENING AS ANOTHER SURGE OF COLDER AIR MOVES SOUTH. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE EASTERN CWA ALONG A DRYLINE AND THEN THE BEST CHANCE OF SHOWERS AND STORMS WILL BE ALONG AND BEHIND THE COLD FRONT ACROSS THE NORTHERN CWA. THIS UPPER LEVEL LOW WILL HAVE SEVERAL SPOKES OF VORTICITY ROTATING AROUND IT AS WELL...SO THE SHOWER AND THUNDERSTORM POTENTIAL WILL PICK UP EACH TIME ONE THESE MOVES OVER THE REGION. ON TUESDAY...WILL KEEP THE SHOWERS AND THUNDERSTORMS GOING AS THE COLD CORE OF THE LOW MOVES OVER THE PANHANDLES. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY ON TUESDAY. PRECIPITATION CHANCES DECREASE FROM SOUTHWEST TO NORTHEAST TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE UPPER LOW MOVES AWAY. UPPER LEVEL SHORT WAVE RIDGING TAKES OVER THE HIGH PLAINS WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AHEAD OF ANOTHER LARGE UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST. A DRYLINE IS EXPECTED TO MOVE TO THE EASTERN CWA BY FRIDAY AFTERNOON. THIS DRYLINE WILL HOLD IN THE EASTERN CWA FRIDAY NIGHT AS THE WIND SHEAR ALOFT INCREASES AS THE UPPER TROUGH MOVES ACROSS THE NORTHERN HIGH PLAINS. THE INCREASED WIND SHEAR AND INSTABILITY MAY LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN CWA FRIDAY NIGHT...SO HAVE ADDED SOME SLIGHT CHANCE POPS FOR NOW. A COLD FRONT MOVES SOUTH ACROSS THE CWA ON SATURDAY NIGHT...COOLING SUNDAY/S HIGHS BACK 10 TO 15 DEGREES. FIRE WEATHER... WILL CONTINUE TO HOLD ONTO THE RED FLAG WARNING FOR THE SOUTHWEST AND SOUTH CENTRAL TEXAS PANHANDLE THROUGH EARLY THIS EVENING. SOUTHWEST WINDS SHOULD INCREASE THROUGH THE REST OF THE AFTERNOON INTO EARLY THIS EVENING AS A SURFACE LOW INTENSIFIES OVER THE CENTRAL TEXAS PANHANDLE. THE WINDS WILL THEN PICK UP BEHIND A COLD FRONT TONIGHT...ESPECIALLY ACROSS THE NORTHWEST CWA...BUT RELATIVE HUMIDITIES WILL BE ABOVE 20 PERCENT. THE CHANCES OF RAIN INCREASE TONIGHT THROUGH TUESDAY. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY UNTIL 4 AM CDT TUESDAY FOR THE FOLLOWING ZONES: DALLAM...HARTLEY...SHERMAN. OK...WIND ADVISORY UNTIL 4 AM CDT TUESDAY FOR THE FOLLOWING ZONES: CIMARRON...TEXAS. && $$ 11/08
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1142 PM CDT MON APR 2 2012 .AVIATION... CLOSED UPPER LOW OVER EASTERN NEW MEXICO TONIGHT ALONG WITH A COLD FRONT WILL ALLOW FOR MAINLY SHOWERS AT THE DALHART AND GUYMON TAF SITES THROUGH ABOUT 00Z TO 03Z WEDNESDAY. LEFT ANY MENTION OF SHOWERS OUT OF THE AMARILLO TAF SITE DUE TO LOW CONFIDENCE...HOWEVER NOT RULING OUT COMPLETELY. NORTHERLY WINDS WILL BE STRONG INITIALLY AT THE DALHART AND GUYMON TAF SITES...AROUND 25 TO 35 KNOTS SUSTAINED WITH HIGHER GUSTS...BUT SHOULD DIMINISH TO AROUND 15 TO 25 KNOTS BY 15Z TUESDAY AND CONTINUING THROUGH 06Z WEDNESDAY. WINDS ARE EXPECTED TO SHIFT TO THE NORTH APPROXIMATELY 06Z TUESDAY WITH SPEEDS ONLY ABOUT 10 TO 20 KNOTS WITH SOME HIGHER GUSTS POSSIBLE. SCHNEIDER && .PREV DISCUSSION... /ISSUED 936 PM CDT MON APR 2 2012/ UPDATE... HAVE EXTENDED THE WIND ADVISORY ACROSS CIMARRON COUNTY THROUGH MIDNIGHT...AND ALLOWED IT TO EXPIRE FOR DALLAM AND HARTLEY COUNTIES. LATEST OBSERVATIONAL AND SHORT-RANGE MODEL DATA SHOW A TIGHT LOW- LEVEL PRESSURE GRADIENT/REINFORCING SURGE OF NORTH/NORTHEAST WINDS TO IMPACT THE WESTERN OK PANHANDLE OVER THE NEXT FEW HOURS. RECENT OBS FROM KENTON...BOISE CITY...AND SPRINGFIELD CONTINUE TO SHOW ADVISORY LEVEL WINDS...AND KENTON JUST BRIEFLY HIT HIGH WIND WARNING CRITERIA. LET THE RED FLAG WARNING ACROSS THE SOUTHWEST/SOUTH CENTRAL TX PANHANDLE EXPIRE AS SCHEDULED AT 9 PM. WINDS HAVE DIMINISHED TO LESS THAN 20 MPH AND RELATIVE HUMIDITIES WILL CONTINUE TO INCREASE OVERNIGHT. ALSO ADJUSTED PRECIP CHANCES FOR THE REST OF TONIGHT BASED ON LATEST RADAR TRENDS. LINE OF CONVECTION RAPIDLY DEVELOPED AS PACIFIC COLD FRONT OVERTOOK DRYLINE. THIS LINE OF SEVERE CONVECTION WILL CONTINUE TO PIVOT NORTHEAST AHEAD OF POTENT MID-LEVEL VORT MAX ROUNDING CLOSED LOW OVER NM. MAIN FOCUS FOR PRECIPITATION EXPECTED TO SET UP OVER THE NORTHERN CWA AFTER MIDNIGHT AS VORT LOBE CONTINUES TO PIVOT NORTH AND EVENTUALLY NORTHWEST. SEVERE THREAT WILL LINGER THE LONGEST ACROSS THE NORTHEAST TX PANHANDLE AND EASTERN HALF OF THE OK PANHANDLE...BUT WILL EVENTUALLY DIMINISH THERE AS WELL LATER TONIGHT AS PACIFIC FRONT CONTINUES TO PUSH EAST AND STATIONARY FRONT ACROSS NORTHERN CWA EVENTUALLY PUSHES SOUTHEAST...SQUEEZING THE DEEPER LOW-LEVEL MOISTURE AND ASSOCIATED INSTABILITY EASTWARD. KB PREV DISCUSSION... /ISSUED 634 PM CDT MON APR 2 2012/ UPDATE... EXPANDED SEVERE THUNDERSTORM WATCH ONE TIER OF COUNTIES WESTWARD. SURFACE FRONT DRAPED SOUTH/SOUTHWEST ACROSS THE EASTERN OK AND NORTHEAST TEXAS PANHANDLE...AND DRYLINE EXTENDING SOUTH FROM THE FRONT ACROSS THE EASTERN TX PANHANDLE...WERE RETREATING TO THE WEST AND NORTHWEST IN RESPONSE TO SURFACE LOW DEVELOPING NORTHEAST INTO THE TX PANHANDLE AHEAD OF STRONG MID-LEVEL VORT MAX PIVOTING AROUND CLOSED MID/UPPER-LEVEL LOW OVER NM. LATEST RUC GUIDANCE SHOWS THIS BOUNDARY WILL CONTINUE TO RETREAT A LITTLE FARTHER EARLY THIS EVENING...BEFORE DRYLINE ACROSS SOUTHEAST TX PANHANDLE GETS OVERTAKEN BY PACIFIC FRONT AND SHOVED EASTWARD. KB PREV DISCUSSION... /ISSUED 625 PM CDT MON APR 2 2012/ UPDATE... CONVECTION WILL CONTINUE TO DEVELOP IN RESPONSE TO A COLD FRONT ACROSS THE PANHANDLES AND APPROACHING UPPER LOW FROM NEW MEXICO. THIS CONVECTION WILL AFFECT ALL OF THE TAF SITES THROUGH 10Z TUESDAY. VFR CONDITIONS WILL PREVAIL EXCEPT MVFR TO POSSIBLY IFR CONDITIONS IN AND NEAR THE CONVECTION. WINDS WILL BECOME NORTHERLY TO NORTHEASTERLY 15 AND 20 TO 25 AND 30 KNOTS WITH HIGHER GUSTS BEHIND THE COLD FRONT...WITH SOUTHERLY TO SOUTHWESTERLY WINDS AHEAD OF THE FRONT MAINLY THIS EVENING AT THE AMARILLO TAF SITE. SCHNEIDER PREV DISCUSSION... /ISSUED 336 PM CDT MON APR 2 2012/ DISCUSSION... UPPER LEVEL LOW HAS CUTOFF FROM THE FLOW OVER CENTRAL NEW MEXICO. THIS LOW IS EXPECTED TO SLOWLY LIFT NORTHEAST THROUGH NORTHEAST NEW MEXICO AND ACROSS THE NORTHWEST PART OF OUR CWA INTO SOUTHWEST KANSAS BY WEDNESDAY AFTERNOON. A SURFACE COLD FRONT HAS STALLED NEAR THE CANADIAN RIVER VALLEY THIS AFTERNOON. THIS FRONT MAY LIFT BACK TO THE NORTH BRIEFLY THIS EVENING BEFORE MOVE SOUTHEAST AGAIN LATER TONIGHT. THE COLD FRONT WILL THEN STALL AGAIN BY TUESDAY AFTERNOON ACROSS THE FAR SOUTHEAST TEXAS PANHANDLE BEFORE MOVING SOUTH OF THE TEXAS PANHANDLE BY TUESDAY EVENING. WILL KEEP THE NORTHWEST CWA UNDER A WIND ADVISORY THROUGH THE MID EVENING AS WINDS ARE EXPECTED TO PICK UP AGAIN BY EARLY THIS EVENING AS ANOTHER SURGE OF COLDER AIR MOVES SOUTH. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE EASTERN CWA ALONG A DRYLINE AND THEN THE BEST CHANCE OF SHOWERS AND STORMS WILL BE ALONG AND BEHIND THE COLD FRONT ACROSS THE NORTHERN CWA. THIS UPPER LEVEL LOW WILL HAVE SEVERAL SPOKES OF VORTICITY ROTATING AROUND IT AS WELL...SO THE SHOWER AND THUNDERSTORM POTENTIAL WILL PICK UP EACH TIME ONE THESE MOVES OVER THE REGION. ON TUESDAY...WILL KEEP THE SHOWERS AND THUNDERSTORMS GOING AS THE COLD CORE OF THE LOW MOVES OVER THE PANHANDLES. FORECAST SOUNDINGS DO SHOW SOME INSTABILITY ON TUESDAY. PRECIPITATION CHANCES DECREASE FROM SOUTHWEST TO NORTHEAST TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE UPPER LOW MOVES AWAY. UPPER LEVEL SHORT WAVE RIDGING TAKES OVER THE HIGH PLAINS WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AHEAD OF ANOTHER LARGE UPPER LEVEL TROUGH MOVING INTO THE PACIFIC NORTHWEST. A DRYLINE IS EXPECTED TO MOVE TO THE EASTERN CWA BY FRIDAY AFTERNOON. THIS DRYLINE WILL HOLD IN THE EASTERN CWA FRIDAY NIGHT AS THE WIND SHEAR ALOFT INCREASES AS THE UPPER TROUGH MOVES ACROSS THE NORTHERN HIGH PLAINS. THE INCREASED WIND SHEAR AND INSTABILITY MAY LEAD TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN CWA FRIDAY NIGHT...SO HAVE ADDED SOME SLIGHT CHANCE POPS FOR NOW. A COLD FRONT MOVES SOUTH ACROSS THE CWA ON SATURDAY NIGHT...COOLING SUNDAY/S HIGHS BACK 10 TO 15 DEGREES. FIRE WEATHER... WILL CONTINUE TO HOLD ONTO THE RED FLAG WARNING FOR THE SOUTHWEST AND SOUTH CENTRAL TEXAS PANHANDLE THROUGH EARLY THIS EVENING. SOUTHWEST WINDS SHOULD INCREASE THROUGH THE REST OF THE AFTERNOON INTO EARLY THIS EVENING AS A SURFACE LOW INTENSIFIES OVER THE CENTRAL TEXAS PANHANDLE. THE WINDS WILL THEN PICK UP BEHIND A COLD FRONT TONIGHT...ESPECIALLY ACROSS THE NORTHWEST CWA...BUT RELATIVE HUMIDITIES WILL BE ABOVE 20 PERCENT. THE CHANCES OF RAIN INCREASE TONIGHT THROUGH TUESDAY. && .AMA WATCHES/WARNINGS/ADVISORIES... TX...WIND ADVISORY UNTIL 4 AM CDT TUESDAY FOR THE FOLLOWING ZONES: DALLAM...HARTLEY...SHERMAN. OK...WIND ADVISORY UNTIL 4 AM CDT TUESDAY FOR THE FOLLOWING ZONES: CIMARRON...TEXAS. && $$ 11/08
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
408 AM CDT TUE APR 3 2012 UPDATED TO ADD SHORT TERM..AVIATION AND MARINE. .SHORT TERM...TODAY AND TONIGHT. FORECAST CONFIDENCE MEDIUM. ELEVATED THUNDERSTORMS THAT DEVELOPED OVER MSP EARLIER IN REGION OF STRONG LAYER FRONTOGENETIC FORCING ON NOSE OF S-SW 30-45 KT 850 MB WINDS IMPINGING ON BAROCLINIC ZONE DRAPED ACROSS NRN/CENTRAL WI. FORCING WEAKENS AS THESE WINDS WEAKEN AND VEER TO THE WEST WITH THE BEST CROSS-ISOTHERM FLOW SHIFTING EAST OF STATE BY 12Z. THIS SHIFT NOTED WITH LATEST DEVELOPMENT TO THE EAST OVER LAKE MICHIGAN...IN LINE WITH RUC AND OTHER SHORT TERM MODEL GUIDANCE. HAVE BACKED OFF POPS FOR THE ENTIRE CWA THIS MORNING...BUT COULD NOT DROP COMPLETELY THIS AFTERNOON AS COULD SEE A FEW LIGHT RAIN SHOWERS WITH CONVERGENCE ALONG BAROCLINIC ZONE AS IT MOVES SOUTH THROUGH CWA THIS AFTERNOON. SOME ELEVATED CAPE WITH BOUNDARY...BUT FORECAST SOUNDINGS SHOW A CAP BETWEEN 800 MB AND 700 MB SO WILL ONLY MENTION ISOLATED THUNDER. HIGHS TO BE REACHED LATE MORNING/EARLY AFTERNOON THEN DROP WITH COLD AIR ADVECTION WITH DEVELOPING NORTH TO NORTHEAST WINDS. 925MB TEMPS SUPPORT HIGHS IN THE MID TO UPPER 60S SOUTH AND SOUTHWEST...WITH MID UPPER 50S NORTHEAST. CLEARING FROM NORTH TO SOUTH OVERNIGHT...THOUGH A FEW CLOUDS MAY LINGER IN THE FAR SOUTH. COLD ADVECTION CONTINUES WITH LOWS DIPPING INTO THE MID 30S NORTH...AND UPPER 30S TO AROUND 40 IN THE SOUTH BY MORNING. COULD SEE SOME PATCHY FROST IN THE NORTH...BUT NOT EXPECTING ENOUGH TO MENTION FOR NOW. WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH SFC HIGH PRESSURE CENTERED JUST TO THE NORTH OF MINNESOTA WEDNESDAY MORNING WILL MEANDER SOUTHEAST TO MICHIGAN BY FRIDAY. MEANWHILE...UPPER RIDGING WILL BUILD BACK INTO THE AREA BEHIND EXITING UPPER LOW TO THE SOUTH. OVERALL...LOOKS LIKE A VERY DRY AIRMASS ACROSS SOUTHERN WISCONSIN FOR THE SECOND HALF OF THE WORK WEEK. NO PRECIP CURRENTLY EXPECTED...WITH ONLY PASSING HIGH CLOUDS AT TIMES. THOUGH SKIES WILL BE MOSTLY SUNNY...MODELS ARE INDICATING A PUSH OF COLDER AIR INTO THE STATE FROM THE NORTHEAST WEDNESDAY NIGHT INTO THURSDAY. IN ADDITION...PERSISTENT EASTERLY WINDS WILL KEEP CHILLY AIR COMING IN OFF THE LAKE. EVEN SO...HIGH TEMPERATURES WILL STILL BE NEAR NORMAL FOR EARLY APRIL...EVEN A BIT ABOVE NORMAL WEDNESDAY AND FRIDAY AWAY FROM THE LAKE. MAY SEE SOME FROST WITH LOWS TEMPS MORE TOWARD NORMAL...PARTICULARLY THU NIGHT WHEN THE WINDS WILL BE FAIRLY LIGHT. SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM MODELS SHOWING A PAIR OF WAVES TO SLIDE THROUGH SAT/SAT NIGHT AND SUN NIGHT/MONDAY. ENOUGH CONFIDENCE TO KEEP SOME POPS GOING. LOOKS LIKE HIGH TEMPS WILL BE 5 TO 10 DEGREES ABOVE NORMAL THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WESTERLY LOW LEVEL FLOW MAY EVEN PUSH THE MILDER TEMPS TO THE LAKE...ESPECIALLY IF STRONG ENOUGH TO OVERCOME THE LAKE BREEZE POTENTIAL THROUGH THE DAY. .AVIATION/12Z TAFS... CONVECTION HAS DEVELOPED WELL TO THE NORTH AND EAST OF TAF SITES EARLY THIS MORNING...REDUCING PROSPECTS OF SEEING ANY CONVECTION TODAY. WILL MONITOR TRENDS OVER THE NEXT FEW HOURS...BUT PLAN IS TO LEAVE ANY PRECIPITATION OUT OF 12Z TAFS. VFR CONDITIONS EXPECTED THROUGH THE PERIOD....WITH COLD ADVECTION STRATUS TO REMAIN IN THE 3500-4000 FT RANGE. EASTERLY WINDS WILL SHIFT TO THE NORTH-NORTHEAST LATE THIS MORNING AND INCREASE TO 10 TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS THIS AFTERNOON AS SURFACE LOW PASSES TO THE SOUTH. .MARINE... HELD OFF ON A SMALL CRAFT ADVISORY FOR TONIGHT AS WINDS AND WAVES REMAIN JUST BELOW CRITERIA WITH WINDS EASING A BIT TONIGHT. GRADIENT TIGHTENS ON WEDNESDAY WITH WAVES BUILDING TO SMALL CRAFT CRITERIA BY WEDNESDAY NIGHT IN PERSISTENT NORTH-NORTHEAST FLOW. WAVES WILL REMAIN HIGH INTO THURSDAY...THEN LOWER WITH SHORTER FETCH AS WINDS VEER TO THE EAST AND EASE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 PM CDT MON APR 2 2012 .SHORT TERM...OVERNIGHT 1130 PM CDT MON APR 2 2012 THE 03.00Z GFS CONTINUES TO OVERDUE THE PRECIPITATION ACROSS THE AREA. AS A RESULT...IGNORED IT WITH THIS UPDATE AND INSTEAD LEANED MORE TOWARD THE NAM/WRF...RUC...AND HRRR SOLUTIONS WHICH SHOW THAT THE BEST MOISTURE TRANSPORT WILL BE FOUND ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR. AS A RESULT...RAISED THE PRECIPITATION CHANCES IN CLARK AND TAYLOR COUNTY TO CATEGORICAL FOR OVERNIGHT. WHILE THE 0-6 KM SHEAR IS GREATER THAN 40 KNOTS...MUCH OF THIS IS BEING AIDED BY THE WINDS IN THE LOWEST 1 KM. WHEN THIS ACCOUNTED FOR...THESE VALUES ARE LESS THAN 20 KNOTS. WE HAVE HAD A FEW HAIL REPORTS NEAR THE CITIES...BUT THIS IS MAINLY A RESULT OF THE ELEVATED CAPE UP 1500 J/KG. THIS IS JUST ENOUGH TO PRODUCE SOME HAIL UP TO ONE INCH...BUT THE THREAT WOULD BE VERY ISOLATED AND SHORT LIVED. .LONG TERM...THURSDAY THROUGH MONDAY 249 PM CDT MON APR 2 2012 THE HIGH WILL REMAIN OVER THE REGION THROUGH FRIDAY MAINTAINING THE POSSIBILITY OF SOME FROST AND FREEZING TEMPERATURES AT NIGHT FOR THE END OF THE WEEK. THE HIGH WILL THEN MOVE OFF FOR THE WEEKEND AS THE NEXT SYSTEM COMES INTO THE AREA. SOME TIMING DIFFERENCES BETWEEN THE 02.12Z GFS...ECMWF AND GEM WITH THE COLD FRONT COMING ACROSS. THE ECMWF AND GEM ARE A LITTLE FASTER BUT ALL SHOW AT LEAST A CHANCE FOR SOME RAIN SATURDAY INTO SATURDAY NIGHT BEFORE IT MOVES OFF TO THE EAST FOR SUNDAY. SOME DIFFERENCES FOR NEXT MONDAY WITH THE ECMWF DROPPING ANOTHER SHORT WAVE TROUGH OVER THE AREA FOR THE POSSIBILITY OF SOME SHOWERS WHILE THE GFS IS DRY WITH HIGH PRESSURE BUILDING IN. WILL HONOR THE ECMWF WITH A SMALL RAIN CHANCE FOR MONDAY. && .AVIATION...THROUGH 06Z WEDNESDAY 1130 PM CDT MON APR 2 2012 AN AREA OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED BETWEEN THE TWIN CITIES AND EAU CLAIRE. A FEW OF THESE THUNDERSTORMS HAVE PRODUCED UP TO DIME SIZE HAIL IN THE CITIES. THESE THUNDERSTORMS WILL STAY NORTH OF BOTH THE TAF SITES...SO NO PLANS TO INCLUDE THEM IN THE TAFS. HWOEVER THERE MAY BE SOME SCATTERED SHOWERS IN THE WAKE OF THE COLD FRONT. THIS FRONT WILL MOVE THROUGH KRST AROUND 03.08Z AND KLSE AROUND 03.10Z. IN ADDITION...THE WINDS WILL SHIFT FROM EAST TO NORTH AND CIELINGS WILL BECOME MVFR. THESE CEILINGS WILL THEN GRADUALLY RISE AND BECOME VFR DURING THE MID TO LATE AFTERNOON...AND THEN MOVE OUT OF THE AREA DURING THE EARLY EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... 1130 PM CDT MON APR 2 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...04 AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
418 AM MDT TUE APR 3 2012 .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 418 AM MDT TUE APR 3 2012 FORECAST PROBLEMS WILL BE PRECIPITATION COVERAGE...AMOUNTS AND EVEN PHASE AS LONG AS UPPER LOW IS IN THE AREA. SATELLITE SHOWING AN AMPLIFIED PATTERN OVER THE NORTHERN HEMISPHERE. MAIN FEATURE OF INTEREST IS UPPER LOW CURRENTLY SPINNING OVER EASTERN NEW MEXICO. PATH AND SPEED OF THIS SYSTEM WILL AFFECT THE FORECAST. THE ECMWF AND GFS WERE DOING BEST ON THE JET WINDS IN THE AREA ASSOCIATED WITH THE UPPER LOW. THE ECMWF AND GFS WERE DOING A LITTLE BETTER THAN THE CANADIAN ON THE POSITION OF THE UPPER LOW AND ASSOCIATED HEIGHT FIELD IN THIS PORTION OF THE COUNTRY. THE NAM AND ECMWF WERE DOING THE BEST ON THE SURFACE FIELD. ON THE LOW LEVEL THERMAL FIELD...THE GFS WAS DOING THE BEST AND A LITTLE BETTER THAN THE NAM. THE OTHER MODELS TENDED TO BE TOO WARM WITH THE NAM IN SOME PLACES SLIGHTLY COOL. TODAY/TONIGHT...RIGHT REAR QUADRANT STARTS OUT OVER THE AREA THIS MORNING. THROUGH THE REST OF THE DAY...THE BEST JET LIFT REMAINS TO THE SOUTH AND WEST OF THE AREA. ALSO CURRENT SHORTWAVE TROUGH WILL MOVE THROUGH THIS MORNING BEFORE DRY SLOT ENTERS THE AREA. CURRENT GRIDS CAPTURE AREA OF GREATEST CHANCE OF PRECIPITATION. THIS AREA IS ALSO MATCHING UP WITH THE SREF QPF. DUE TO SOME EMBEDDED CONVECTION AND INTENSE RAINFALL RATES...SOME AREAS IN EASTERN COLORADO ARE RECEIVING SNOW AT THIS TIME WITH THE MOST INTENSE PRECIPITATION. KITR IS RECEIVING SNOW AT THIS TIME. WILL CONTINUE TO WATCH THE TRENDS ON THE PRECIPITATION/TEMPERATURES AND PUT IN A RAIN OR RAIN AND SNOW MIX. BASED ON WHAT IS GOING AT THIS TIME AND MODELS INDICATING ELEVATED INSTABILITY...WILL BE INSERTING SOME ISOLATED TRW-. MODELS ARE COMING IN TO BETTER AGREEMENT AND HAVE THE MID LEVEL CIRCULATION IN A VERY FAVORABLE LOCATION FOR WIDESPREAD PRECIPITATION THIS AFTERNOON INTO TONIGHT. DEEP UPSLOPE/MOISTURE ALONG WITH STRONG SYNOPTIC SCALE/MESOSCALE FORCING AND ISENTROPIC LIFT ARE ALL SHOWN BY THE MODELS. BASED ON THE PREVIOUS REASONING LIKE THE HIGH MODEL QPFS GENERATED...HOWEVER WITH BULLSEYES IN DIFFERENT PLACES. SREF/HPC PQPF SHOW A GREATER THAN 50 PERCENT CHANCE OF MORE THAN AN INCH ACCUMULATION OF LIQUID ON VARIOUS TIME SCALES. AS A RESULT WENT WITH MODERATE RAINFALL...AND CONTINUED EMBEDDED CONVECTION DUE TO THE ELEVATED INSTABILITY...AND WITH THE HPC QPF WHICH IS IN CLOSE AGREEMENT TO THE ECMWF SOLUTION WHICH BASED ON THE MAJORITY OF MODEL OUTPUT...CONSISTENCY...AND CURRENT FLOW PATTERN LOOKS VERY REASONABLE. MODELS KEEP UPSLOPE FLOW OR LOW LEVEL ISENTROPIC LIFT IN PLACE THROUGH THE DAY ALONG WITH OFF AND ON PRECIPITATION. SO SEE NO CHANCE TO WARM VERY MUCH. WILL ADJUST FINAL MAXES AS SEE HOW FAR CURRENT MINS DROP. WEDNESDAY/WEDNESDAY NIGHT...AS STATED ABOVE...LIKE THE ECMWF SOLUTION. IT IS SLOWER THAN EVERYTHING ELSE AND MAKES SENSE. HOWEVER IT MAY NOT BE FAR ENOUGH NORTH AS IT KICKS OUT DUE TO THE STRONG DOWNSTREAM RIDGE. SO PRECIPITATION WILL BE SLOWER TO END AND CLOUD COVER WILL ALSO HANG AROUND LONGER. WILL ADJUST MAXES LOWER AND PRECIPITATION HIGHER BASED ON THIS WITH PRECIPITATION CHANCES HIGHER AND LASTING LONGER IN THE EAST. MODELS CLEAR EVERYTHING OUT BY LATER IN THE NIGHT. WIND FIELD WILL BE LIGHT WITH LEFTOVER MOIST LOW LEVEL AIR MASS AND MOIST GROUND OVER A LARGE AREA. MORE THAN ONE MODEL GENERATES FOG AND WILL INSERT IT IN...MAINLY AFTER 06Z. THURSDAY/THURSDAY NIGHT...WILL CONTINUE THE FOG IN THE MORNING. LOW CLOUDS AND FOG IN THE MORNING COMBINED WITH LIGHT AND VARIABLE WINDS OR UPSLOPE WINDS WILL KEEP TEMPERATURES FROM RISING TOO MUCH. IN FACT WHAT IS IN THERE MAY END UP BEING TOO WARM AND THIS WILL NEED TO BE LOOKED AT AGAIN. DO NOT EXPECT THE LOW LEVEL AIR MASS TO DRY OUT MUCH DUE TO THE EXPECTED WIDE SPREAD PRECIPITATION THAT HAS JUST ENDED. ALSO MODELS INCREASE SOUTH TO SOUTHEAST LOW LEVEL FLOW WHICH DRAWS IN EVEN MORE MOISTURE OR KEEPS IT HERE. AT THE VERY LEAST SHOULD BE WIDESPREAD STRATUS BUT ALSO PROBABLY ANOTHER ROUND OF FOG. THANKS TO ALL THAT COLLABORATED. .LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 418 AM MDT TUE APR 3 2012 MID/UPPER TROUGH WILL REMAIN TO OUR WEST/NORTHWEST EARLY FRIDAY BUT A LEAD SHORTWAVE TROUGH IS PROGGED TO TRANSLATE ACROSS THE REGION DURING THE DAY. WILL MAINTAIN INHERITED SLIGHT CHANCE POPS OVER THE EASTERN THIRD. PRECIP MAY LINGER INTO SATURDAY MORNING BEFORE SUBSIDENCE OVERTAKES THE REGION BEHIND A SURFACE COLD FRONT. STRONG SOUTHERLY FLOW AHEAD OF THE TROUGH WILL ALLOW TEMPS ON FRIDAY TO WARM INTO THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A MUCH DRIER AIR MASS WILL FILTER INTO THE WESTERN HALF OF THE FORECAST AREA ON SATURDAY WHICH COULD RESULT IN A CRITICAL FIRE WEATHER DAY. CURRENT WIND SPEEDS ARE PROGGED TO BE BORDERLINE. THE OVERALL THREAT FOR CRITICAL FIRE WEATHER WILL LIKELY BE MITIGATED TO SOME EXTENT BY THE WIDESPREAD MOISTURE EXPECTED TO IMPACT THE REGION OVER THE NEXT 36 HOURS. QUASI-ZONAL FLOW SETS UP ON SUNDAY BEFORE SHIFTING TO MORE NORTHWESTERLY FLOW ALOFT IN RESPONSE TO A BUILDING RIDGE ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST. SERIES OF WEAK SHORTWAVE TROUGHS WILL PASS THROUGH THE AREA KEEPING TEMPS SEASONABLE. LIMITED AVAILABLE MOISTURE WILL LIKELY PRECLUDE THE DEVELOPMENT OF WIDESPREAD PRECIPITATION. && .AVIATION...FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1032 PM MDT MON APR 2 2012 RUC IS HANDLING THE CLOUDS FAIRLY WELL SO HAVE USED THIS MODEL AS WELL AS THE HRRR CONCERNING THE PRECIPITATION. MVFR CIGS AT BOTH KGLD AND KMCK TO CONTINUE THROUGH THE NEXT 24 HOURS. BAND OF PRECIPITATION WILL IMPACT BOTH TERMINALS AT THE BEGINNING OF THE TAF PERIOD AND CONTINUE THROUGH 10Z-11Z BEFORE ROTATING OUT OF THE AREA AS MID LEVEL DRY SLOT MOVES IN. THERE IS A CHANCE FOR SEVERAL HOURS OF IFR CONDITIONS AT BOTH TERMINALS TIL 16Z OR SO WHEN ANOTHER BATCH OF PRECIP MOVES NORTH IMPACTING KGLD AROUND 16Z AND KMCK AROUND 00Z. THIS BATCH OF PRECIP SHOULD CONTINUE THROUGH THE REMAINDER OF THE TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM....FOLTZ AVIATION...BAS/DDT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1200 PM EDT TUE APR 3 2012 .SYNOPSIS... A WARM FRONT WILL BRING THE CHANCE OF SHOWERS AND THUNDERSTORMS IN EASTERN OHIO THIS AFTERNOON. LOW PRESSURE MOVING ACROSS THE OHIO VALLEY TODAY WILL MOVE INTO THE AREA OVERNIGHT AND BRING SCATTERED SHOWERS AND THUNDERSTORMS. CANADIAN HIGH PRESSURE WILL FOLLOW WITH DRY, SEASONABLE CONDITIONS INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ADD POPS IN EASTERN OHIO AS WEAKENING CONVECTION MOVES INTO THE AREA. THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A NEAR ZONAL FLOW ON THE NORTHERN PERIPHERY OF A WEAK RIDGE ACROSS THE OHIO VALLEY. AT THE SURFACE, A 1010MB IS LOCATED ACROSS CENTRAL ILLINOIS WITH A WARM FRONT EXTENDING INTO NORTHERN OHIO. A CONVECTIVE COMPLEX IN NORTHERN OHIO HAS DEVELOPED WITH OVERRUNNING ALONG AND AHEAD OF THE WARM FRONT. TODAY...CONVECTION ACROSS NORTHERN OHIO WILL WEAKEN AND DIMINISH AS IT ENCOUNTERS DRIER AIR AND SLIDES SOUTHEASTWARD INTO EAST- CENTRAL OHIO. THUS, CHANCE POPS ARE FORECAST THIS AFTERNOON THERE. OTHERWISE, DRY AIR AT THE SURFACE, INDICATED BY TD DEPRESSIONS OF 25-30F, SHOULD LIMIT THE INITIAL EASTWARD PROGRESSION OF SHOWERS INTO THE AREA. THE WARM FRONT WILL PUSH INTO THE AREA FROM THE SOUTHWEST AS THE SURFACE LOW TREKS ACROSS THE OHIO VALLEY AND TEMPS WILL CONTINUE TO WARM INTO THE EVENING. FORECAST CONSISTS OF A HRRR/LAMP BLEND, WITH HIGHS RANGING FROM THE MID 70S ACROSS EASTERN OHIO AND NORTH-CENTRAL WV TO THE MID 60S ALONG THE I-80 CORRIDOR. TONIGHT...THE SURFACE LOW WILL MOVE INTO WESTERN PENNSYLVANIA AS THE WARM FRONT STRADDLES THE AREA. MODERATE INSTABILITY UPSTREAM IN OHIO WILL ALLOW FOR CONVECTION TO DEVELOP THERE AND THEN PUSH INTO THE AREA OVERNIGHT. NAM/GFS INDICATE AN AREA OF ELEVATED INSTABILITY PUSHING ACROSS EASTERN OHIO AND ALLOWING FOR THE CHANCE OF THUNDERSTORMS TO CONTINUE ACROSS THE AREA OVERNIGHT. VERTICAL SHEAR IS RELATIVELY WEAK, SO BELIEVE THE SEVERE THREAT WILL BE LIMITED. HOWEVER, CANNOT RULE OUT THE ISOLATED POSSIBILITY OF HAIL IN EASTERN OHIO. BY DAWN, THE FRONTAL BOUNDARY WILL HAVE PUSHED SOUTHWARD TO THE MASON-DIXON LINE, WITH LINGERING SHOWERS ALONG AND SOUTH OF THE BOUNDARY. OVERNIGHT LOWS ARE A FEW DEGREES WARM THAN LAMP GUIDANCE, RANGING FROM THE LOWER 40S NORTH OF THE BOUNDARY ALONG THE I-80 CORRIDOR TO THE MID 50S IN NORTH-CENTRAL WV. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... PASSAGE OF THE LOW PRESSURE LATE TNGT/EARLY WEDNESDAY WL AMPLIFY FLOW ALOFT/PUSH A COLD FRONT ACROSS THE AREA. SHOWER AND THUNDERSTORM CHANCES ARE THUS FORECAST TO INCREASE TONIGHT AS LOW PRESSURE CENTER IS PROJECTED TO MOVE EASTWARD ALONG THE SOUTHWARD SAGGING FRONTAL BOUNDARY. PRECIP PROBABILITIES IN THE CHANCE CATEGORY WL BE MAINTAINED FOR MOST ZONES GIVEN PROGS OF LIMITED MOISTURE RETURN...BUT LIKELY NUMBERS WL BE INCLUDED FOR COUNTIES ALONG AND SOUTH OF I 70 AS THE ADVANCING LOW IMPROVES THE MOISTURE PROFILE FOR THOSE ZONES. THE STORM PREDICTION CENTER HAS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF EAST CENTRAL OHIO FOR TONIGHT. HAVE OPTED TO MENTION NO MORE THAN A LOW PROBABILITY AT THIS TIME AS MOST SREF MODEL MEMBERS SHOW RATHER WEAK INSTABILITY AND VERTICAL SHEAR. AT ANY RATE...THAT LOW WL ALSO PULL THE COLD FRONT SUFFICIENTLY SOUTHWARD WITH ITS WEDNESDAY PASSAGE TO QUICKLY DRY THE WEATHER FOR THE REMAINDER OF THE SHORT TERM PERIOD. TROUGH ALOFT/COOL HIGH PRESSURE ON THE SURFACE WL RETURN TEMPERATURES BACK TO NORMAL...WITH FREEZES POSSIBLE ON THURSDAY AND FRIDAY MORNINGS ACROSS THE AREAS NORTH AND EAST OF PITTSBURGH. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO DAYTIME SUNDAY. CONSENSUS OF MODELS THEN SHOW THE UPPER LEVEL JET STREAM PATTERN BECOMING MORE ZONAL WITH A SOUTHWEST ORIENTATION. THIS ZONAL UPPER FLOW WILL STEER A COLD FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY SUNDAY NIGHT INTO MONDAY. FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAEFS MODEL OUTPUT, TO BE NEAR NORMAL FRIDAY, FOLLOWED BY A PREFRONTAL WARM UP SATURDAY AND SUNDAY TO VALUES UP TO 10 DEGREES ABOVE NORMAL. TEMPERATURES MONDAY SHOULD BE CLOSER TO NORMAL DUE TO CLOUDS AND SHOWERS AND POTENTIAL POSTFRONTAL COOLING, ALTHOUGH THE LATTER WILL BE LIMITED BY THE SOUTHWEST WINDS ALOFT. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... RECENT SURFACE AND SATELLITE DATA SHOW VFR WILL CONTINUE ACROSS THE UPPER OHIO VALLEY THIS AFTERNOON. RECENT RADAR DATA CONTINUES TO SHOW A SLOW SOUTHEASTWARD MOVING THUNDERSTORM COMPLEX OVER NORTHERN OHIO. RECENT HRRR MODEL OUTPUT CONTINUES TO SHOW DISSIPATION BEFORE AFFECTING ANY TAF SITES SUCH AS KZZV OR KFKL. HENCE HAVE MAINTAINED VFR INTO EVENING. SURFACE WINDS WILL BECOME SOUTH TO SOUTHWEST NEAR 10 KTS THIS AFTERNOON. OUTLOOK...TONIGHT THROUGH SATURDAY... RESTRICTIONS POSSIBLE LATER TONIGHT INTO WEDNESDAY MORNING DUE TO SHOWERS AND POSSIBLE THUNDERSTORMS ASSOCIATED WITH COLD FRONTAL PASSAGE. VFR WEDNESDAY AFTERNOON INTO SATURDAY DUE TO HIGH PRESSURE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
839 AM EDT TUE APR 3 2012 .SYNOPSIS... LOW PRESSURE, COMING EAST FROM IOWA, WILL PUSH A COLD FRONT WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE UPPER OHIO VALLEY TONIGHT. CANADIAN HIGH PRESSURE WILL FOLLOW WITH DRY, SEASONABLE CONDITIONS INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HAVE ALLOWED FREEZE WARNING TO EXPIRE AT 8 AM. RECENT SURFACE DATA SHOWS SURFACE TEMPERATURES IN MANY AREAS WILL HAVE WARMED PAST 32 BEFORE 9 AM. SO ANY REMAINING PATCHES OF FROST WILL GONE BY THEN ALSO. RECENT RADAR DATA SHOWS A THUNDERSTORM COMPLEX MOVING SOUTHEASTWARD OUT OF SOUTHERN MICHIGAN, WHICH WILL NEED MONITORED. DRY CONDITIONS OVER THE UPPER OHIO VALLEY SHOULD CAUSE THIS COMPLEX TO WEAKEN OR DISSIPATE BEFOREHAND. MOST MODELS SUPPORT THIS IDEA OF DISSIPATION INCLUDING RECENT HRRR MODEL OUTPUT. HOWEVER, WRF-NMM SUGGESTS DAYTIME WARMING AND AN INCREASE IN SURFACE LAYER MOISTURE, DUE TO POSSIBLE WARM FRONTOGENESIS THIS AFTERNOON, MAY AID REDEVELOPMENT OVER EAST CENTRAL OHIO BEFORE EVENING. TODAYS WARM ADVECTION REGIME SUPPORTS TEMPERATURES ABOUT 10 DEGREES ABOVE THE SEASONAL AVERAGES. READING WERE FORECAST USING TWEAKED SREF NUMBERS. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... PASSAGE OF THE LOW PRESSURE LATE TNGT/EARLY WEDNESDAY WL AMPLIFY FLOW ALOFT/PUSH A COLD FRONT ACROSS THE AREA. SHOWER AND THUNDERSTORM CHANCES ARE THUS FORECAST TO INCREASE TONIGHT AS LOW PRESSURE CENTER IS PROJECTED TO MOVE EASTWARD ALONG THE SOUTHWARD SAGGING FRONTAL BOUNDARY. PRECIP PROBABILITIES IN THE CHANCE CATEGORY WL BE MAINTAINED FOR MOST ZONES GIVEN PROGS OF LIMITED MOISTURE RETURN...BUT LIKELY NUMBERS WL BE INCLUDED FOR COUNTIES ALONG AND SOUTH OF I 70 AS THE ADVANCING LOW IMPROVES THE MOISTURE PROFILE FOR THOSE ZONES. THE STORM PREDICTION CENTER HAS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF EAST CENTRAL OHIO FOR TONIGHT. HAVE OPTED TO MENTION NO MORE THAN A LOW PROBABILITY AT THIS TIME AS MOST SREF MODEL MEMBERS SHOW RATHER WEAK INSTABILITY AND VERTICAL SHEAR. AT ANY RATE...THAT LOW WL ALSO PULL THE COLD FRONT SUFFICIENTLY SOUTHWARD WITH ITS WEDNESDAY PASSAGE TO QUICKLY DRY THE WEATHER FOR THE REMAINDER OF THE SHORT TERM PERIOD. TROUGH ALOFT/COOL HIGH PRESSURE ON THE SURFACE WL RETURN TEMPERATURES BACK TO NORMAL...WITH FREEZES POSSIBLE ON THURSDAY AND FRIDAY MORNINGS ACROSS THE AREAS NORTH AND EAST OF PITTSBURGH. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO DAYTIME SUNDAY. CONSENSUS OF MODELS THEN SHOW THE UPPER LEVEL JET STREAM PATTERN BECOMING MORE ZONAL WITH A SOUTHWEST ORIENTATION. THIS ZONAL UPPER FLOW WILL STEER A COLD FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY SUNDAY NIGHT INTO MONDAY. FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAEFS MODEL OUTPUT, TO BE NEAR NORMAL FRIDAY, FOLLOWED BY A PREFRONTAL WARM UP SATURDAY AND SUNDAY TO VALUES UP TO 10 DEGREES ABOVE NORMAL. TEMPERATURES MONDAY SHOULD BE CLOSER TO NORMAL DUE TO CLOUDS AND SHOWERS AND POTENTIAL POSTFRONTAL COOLING, ALTHOUGH THE LATTER WILL BE LIMITED BY THE SOUTHWEST WINDS ALOFT. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... SKIES WILL BE CLEAR UNDER HIGH PRESSURE WITH CALM WINDS INTO MID MORNING THEN A FEW CU WILL DEVELOP BY AFTERNOON. AS SURFACE RIDGE SHIFTS EAST WINDS WILL BECOMING SOUTH UNDER 10 KTS. OUTLOOK...TONIGHT THROUGH SATURDAY... RESTRICTIONS POSSIBLE LATE TONIGHT INTO FIRST HALF OF WEDNESDAY WITH SHOWERS AND POSSIBLE THUNDERSTORMS ASSOCIATED WITH COLD FRONTAL PASSAGE. VFR WEDNESDAY AFTERNOON INTO SATURDAY DUE TO HIGH PRESSURE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1046 AM EDT TUE APR 3 2012 .SYNOPSIS... A WEAK COLD FRONT WILL CROSS NORTHERN MICHIGAN THIS MORNING AND EARLY IN THE AFTERNOON. RAIN CHANCES WILL END BY THIS EVENING. AFTER THAT...HIGH PRESSURE WILL MOVE SOUTH OUT OF CENTRAL CANADA. THIS WILL PROVIDE QUIET WEATHER...WITH A SERIES OF CHILLY NIGHTS BUT RELATIVELY MILD DAYS. OUR NEXT CHANCE FOR RAIN WILL WAIT UNTIL SATURDAY NIGHT AND SUNDAY. && .UPDATE... ISSUED AT 1036 AM EDT TUE APR 3 2012 SHARPENING SHORTWAVE WORKING INTO ONTARIO CONTINUES TO FLATTEN THE UPPER RIDGE OVERHEAD...AS LOW LEVEL TROUGHING TRACKS TOWARD EASTERN UPPER. THERE HAVE BEEN A FEW REPORTS OF SOME VERY LIGHT RAIN OR DRIZZLE ASSOCIATED WITH THE TROUGH. THIS TROUGH CONNECTS BACK TO A WEAKENING AREA OF LOW PRESSURE THAT WAS SHIFTING ACROSS ILLINOIS THIS MORNING. SFC-H8 WARM FRONT WELL SOUTH OF US ALONG WITH THE MAIN INSTABILITY AND THUNDER POTENTIAL. REMOVED THUNDER FROM THE FORECAST...HOWEVER...DECAYING AREA OF LIGHT SHOWERS CONTINUES TO TRACK ACROSS ARENAC/GLADWIN COUNTIES. THIS PRECIPITATION WILL BE GONE IN THE NEXT HOUR. WE WILL THEN BE AWAITING UPSTREAM TROUGHING TO BRING IN SMALL CHANCE/PATCHY AREAS OF LIGHT RAIN/DRIZZLE. CHANCES LIKELY SMALLER THAN THAT...AS CONVERGENCE ASSOCIATED WITH THE TROUGH WANES...AS SOUTHERLY WINDS AHEAD OF IT WILL ALREADY BE TURNING AROUND OUT OF THE NORTH WITH PASSAGE OF LOW PRESSURE IN ILLINOIS. RATHER CLOUDY THROUGH MUCH OF THE DAY. VERY DRY AIR RETURNS TO EASTERN UPPER IN THE MID AFTERNOON HOURS...AND THEN LATE AFTERNOON/EVENING IN NRN LOWER. TEMPERATURES LOOKED REASONABLE WITH THE ONLY CHANGE WAS TO INCREASE HIGHS IN EASTERN UPPER DUE TO A BIT MORE SUNSHINE EXPECTED. UPDATE ISSUED AT 811 AM EDT TUE APR 3 2012 INITIAL BATCH OF SHWRS EXITED INTO LAKE HURON BY 6 AM. THE ENHANCED STRATIFORM AREA OF -RA WAS OVER LAKE MI AND WILL MOVE INTO NW LOWER MI IN THE NEXT HOUR. SINCE MCS WAS OVER CENTRAL WI AT TIME OF 313 AM FCST ISSUANCE...UNCERTAINTY HAS DIMINISHED ON ITS ARRIVAL. SO POPS WERE INCREASED TO 100% AND HAVE TIMED THIS THRU NRN LOWER PENINSULA. IF IT HOLDS TOGETHER...THE BACK EDGE SHOULD BE OFFSHORE INTO LAKE HURON NO LATER THAN 2 PM. THUNDER: THE BEST ARC OF ELEVATED INSTABILITY IS S OF M-55. BUT THE M-55 CORRIDOR HAS THE "BEST" CHC FOR THUNDER. WE SEE THE NEW SHWRS GOING UP OVER MANISTEE/WEXFORD COUNTIES. THAT OFFERS BETTER POTENTIAL THAN THE STRATIFORM AREA. A TENTH OF LIQUID WAS MEASURED AT STURGEON WI...ON THE W COAST OF LAKE MI IN THE PAST HOUR. SO A FEW HUNDREDTHS WILL FALL. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 QUITE AN AMPLIFIED PATTERN ONGOING OVER THE WESTERN HEMISPHERE EARLY THIS MORNING...WITH LARGE SCALE TROUGHS ANCHORED ALONG BOTH COASTS OF NOAM WITH A REX BLOCK-LIKE FEATURE STUCK BETWEEN THESE...KEEPING THE WEATHER SOMEWHAT INTERESTING OVER WHAT WOULD OTHERWISE BE LARGE-SCALE RIDGING. THE FOCUS FOR THE NEAR TERM AND THROUGH TODAY IS SHOWER AND THUNDERSTORM POTENTIAL AS INVERTED TROUGH PULLS INTO THE REGION FROM THE WEST. OVERNIGHT...SHOWERS AND THUNDERSTORMS HAVE MADE THE MOST OF VERY MEAGER INSTABILITY...CONTINUOUSLY FIRING ALONG THE H85 MOISTURE BOUNDARY AS IT PUSHES EAST INTO THE REGION. THROUGH DAYBREAK...I EXPECT AREAS FROM M-32 NORTH TO SEE SOME SHRA ACTIVITY /WITH A FEW EMBEDDED RUMBLES/...WITH A FEW MORE SHOWERS DOWN NEAR MANISTEE. THINGS GET TRICKIER AS WE HEAD INTO THE DAY TODAY...WITH THE IMPACTS OF ANOTHER CONVECTIVE COMPLEX NOW OVER WESTERN WISCONSIN NOT SO CERTAIN. CORFIDI VECTORS SUGGEST THAT THIS COMPLEX WILL PUSH EAST AND THEN SOUTHEAST...OVER THE TOP OF THE H5 RIDGE AXIS...WHICH WOULD SUGGEST ARRIVAL NEAR MY SOUTHWEST ZONES TOWARDS 12Z. THE HRRR IS ON BOARD WITH THIS...AS IS OUR PREVIOUS GRIDDED FORECAST AND WILL CONTINUE EARLY MORNING LIKELY POPS BASICALLY SOUTH OF M-72 AND WEST OF INTERSTATE 75. GIVEN THE TIME OF DAY...EXPECT THIS COMPLEX TO DIE AS IT MOVES EAST...WITH LITTLE TO HANG YOUR HAT ON FOR FORCING FOR THE REMAINDER OF THE DAY AS AFOREMENTIONED INVERTED TROUGH INCREASES LOW LEVEL CONVERGENCE TO SOME EXTENT. STILL...WITH MOIST PLUME OVERHEAD...AND CVA FROM WAVE NOW MOVING INTO WESTERN ONTARIO...EXPECT SOME ADDITIONAL SHOWERS TO POP UP ALONG THE H85 COLD FRONT AS IT SAGS THROUGH THE REGION THIS AFTERNOON. CONFIDENCE IS PRETTY LOW IN HOW THIS EVOLVES THIS AFTERNOON...AND THAT IS WHY I/LL KEEP POPS IN THE CHANCE CATEGORY. TEMPERATURES LIKELY WON/T MAKE TOO MUCH PROGRESS GIVEN CLOUD COVER. REALLY LIKED INHERITED HIGHS IN THE LOWER 50S /WITH A FEW MID 50S OVER SOUTHERN AREAS/ AND WILL CONTINUE THEM IN THIS PACKAGE. THIS IS TOWARDS THE COOLER END OF THE GUIDANCE ENVELOPE. TONIGHT...DRIER AIR PUSHES INTO THE REGION AS INVERTED TROUGH SCOOTS TO THE SOUTHEAST OF THE AREA WITH DEEP LAYER NORTHWEST FLOW DEVELOPING. THIS SHOULD SCOUR OUT ANY REMNANT LOW LEVEL MOISTURE...BRINGING CLEARING SKIES. WITH WINDS LIKELY TO REMAIN COUPLED...I DON/T EXPECT LOWS TO FALL ALL THAT FAR...WITH FAIRLY HOMOGENEOUS VALUES NEAR OR A LITTLE ABOVE 30 EXPECTED. WEDNESDAY...EXPANSIVE AREA OF HIGH PRESSURE BUILDS SOUTH INTO THE HUDSON BAY REGION WITH DRY NORTHWESTERLY FLOW VEERING NORTHERLY DURING THE DAY UNDER CONTINUED COLD ADVECTION. GIVEN VERY DRY ARRIVING AIRMASS...EXPECT A SUNNY/MSUNNY DAY WITH AMPLE SUBSIDENCE TO ENSURE LITTLE IN THE WAY OF CUMULUS DEVELOPMENT. WITH THE AFOREMENTIONED SUBSIDENCE...WOULDN/T BE SURPRISED IF WE DON/T MIX QUITE AS HIGH AS THE MODELS ARE ADVERTISING...AND UNDER COLD ADVECTION FEEL TEMPS WILL STRUGGLE A LITTLE. THEREFORE...WILL FOLLOW CLOSER TO THE COOLER SIDE OF THE GUIDANCE ENVELOPE /MET/ WITH HIGHS IN THE MID 40S OVER EASTERN UPPER...TO THE LOWER 50S OVER NORTHERN LOWER. GIVEN THE FLOW TRAJECTORIES AND SUBSIDENT FLOW...EXPECT A VERY DRY AIRMASS WITH DEWPOINTS LIKELY TUMBLING INTO THE UPPER TEENS BY MID/LATE AFTERNOON. THIS WILL BRING MINIMUM RH/S INTO THE 20S. WITH GUSTY NORTH/NORTHWEST WINDS...WILL CONTINUE ELEVATED FIRE DANGER WORDING IN THE MORNING HWO...BUT TEMPERATURES WILL BE WELL BELOW RED FLAG LEVELS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 UPPER PATTERN REMAINS ONLY VERY SLOWLY PROGRESSIVE THRU THE REST OF THE WORK WEEK AND INTO THE WEEKEND. THAT WILL STILL EVENTUALLY BRING THE PAC NW UPPER TROF EASTWARD INTO OUR REGION...BUT LIKELY NOT UNTIL THE END OF THE WEEKEND. BEFORE THEN...THURSDAY/FRIDAY/SATURDAY CONTINUE TO LOOK RELATIVELY UNEVENTFUL...WITH SURFACE HIGH PRESSURE ENTRENCHED IN THE GREAT LAKES REGION. WED NIGHT-SAT...A REASONABLY VIGOROUS SHORTWAVE DROPS SOUTH ACROSS THE NORTHERN LAKES WED NIGHT. THIS SYSTEM IS MOISTURE-STARVED...AND WILL BRING NO MORE THAN SOME MID-HIGH CLOUDS...PRIMARILY TO EASTERN UPPER AND NE LOWER MI. HOWEVER...IT WILL PUSH A SECONDARY COLD FRONT ACROSS THE AREA...HELPING TO MAINTAIN 850MB TEMPS IN THE -6 TO -8C RANGE BY THU MORNING. WARM ADVECTION (ON N TO NE LOW LEVEL FLOW) AND AIRMASS MODIFICATION BEGIN SHORTLY THEREAFTER. BUT WE WILL STILL SEE SOMEWHAT COOLISH TEMPS...ESPECIALLY WED NIGHT AND THU NIGHT. EXPECT MINS MAINLY IN THE 20S...AND COULD DEFINITELY SEE TEENS IN THE USUAL COLD INTERIOR LOCALES. GIVEN OUR EARLY START TO THE GROWING SEASON...FROST/FREEZE HEADLINES COULD WELL BE NEEDED ON BOTH NIGHTS. WE/LL SEE ENOUGH SUN TO KEEP MAX TEMPS RESPECTABLE THURSDAY...MID 40S TO AROUND 50. RH LEVELS WILL BE PRETTY LOW DESPITE THE COOLISH TEMPS...WITH DEW POINTS IN THE TEENS (PERHAPS LOWER) AT PEAK HEATING. FOR NOW...IT LOOKS LIKE WE WON/T QUITE HAVE ENOUGH OF A NORTHERLY BREEZE TO MAKE FOR AN ENHANCED FIRE THREAT DAY. HIGH PRESSURE MOVES OVERHEAD BY FRIDAY...AND THE AIRMASS WILL CONTINUE TO MODERATE. MAX TEMPS WILL JUMP INTO THE 50S FRIDAY...AND WILL APPROACH 60F IN SPOTS SATURDAY...WITH PLENTY OF SUNSHINE. AFTER A DAY WITH HARDLY ANY WIND FRIDAY...A DEVELOPING SOUTHERLY BREEZE SATURDAY COULD ALSO PRODUCE AN ENHANCED FIRE THREAT...THOUGH FOR NOW (LIKE THURSDAY) FORECAST WINDS AREN/T QUITE STRONG ENOUGH. LATER PERIODS...TIMING AGREEMENT REMAINS DECENT ON LOW PRESSURE LIFTING TOWARD HUDSON BAY SAT NIGHT/SUNDAY...AND AN ASSOCIATED COLD FRONT CROSSING MI LATE SAT NIGHT/SUNDAY MORNING. CHANCE POPS STILL IN ORDER WAY OUT THEN. DEPENDING ON YOUR MODEL SOLUTION OF CHOICE... MAY HAVE ENOUGH COOL AIR AND DEEP CYCLONIC FLOW TO PRODUCE A CHANCE FOR RAIN/SNOW SHOWERS ON MONDAY. THE OPERATIONAL GFS IS AMONGST THE CHILLIEST/MOST MOIST BY MONDAY...IT HAS BEEN KNOWN TO OVERDUE THESE SORTS OF THINGS FROM TIME TO TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 811 AM EDT TUE APR 3 2012 TODAY: ONE-HOUR BATCH OF VFR -RA WILL ADVANCE ACROSS THE TAF SITES. CLOUDS WILL BE MULTI-LAYERED. WINDS WILL BE LIGHT FROM THE SE THRU 17Z /THO AT TIMES VARIABLE DIR/. THEN AN ABRUPT WSHFT TO WNW-NW WITH AN INCREASE TO 10 KTS WITH SOME GUSTINESS TO 16 KTS. PKWND COULD BE AS HIGH AS 20 KTS BRIEFLY. AFTER WSHFT...THERE IS SOME POTENTIAL FOR A 1-3 HOUR WINDOW OF MVFR CIGS. THEY OVER CURRENTLY OVER NW WI...BUT CONFIDENCE IS NOT HIGH ENUF TO INCLUDE IN THIS TAF ISSUANCE. TNGT: RAPID CLEARING 23-01Z. LIGHT NW WINDS 5 KTS OR LESS. && .MARINE... ISSUED AT 313 AM EDT TUE APR 3 2012 WINDS/WAVES LOOK TO GENERALLY REMAIN BELOW LEVELS HAZARDOUS TO SMALL CRAFT THROUGH TUESDAY NIGHT AS TROUGH OF LOW PRESSURE MOVES THROUGH THE REGION TODAY WITH NORTHWESTERLY WINDS DEVELOPING LATE THIS AFTERNOON AND TONIGHT. THESE NORTHWESTERLY WINDS WILL STRENGTHEN ON WEDNESDAY AS CANADIAN HIGH PRESSURE BUILDS TOWARDS THE REGION. THIS WILL LIKELY BRING A PERIOD OF SMALL CRAFT CONDITIONS ON WEDNESDAY BEFORE THE AFORMENTIONED HIGH SETTLES OVERHEAD WITH QUIET CONDITIONS FOR THE END OF THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...SD SYNOPSIS...JZ SHORT TERM...JA LONG TERM....JZ AVIATION...HALBLAUB MARINE...JA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
811 AM EDT TUE APR 3 2012 .SYNOPSIS... A WEAK COLD FRONT WILL CROSS NORTHERN MICHIGAN THIS MORNING AND EARLY IN THE AFTERNOON. RAIN CHANCES WILL END BY THIS EVENING. AFTER THAT...HIGH PRESSURE WILL MOVE SOUTH OUT OF CENTRAL CANADA. THIS WILL PROVIDE QUIET WEATHER...WITH A SERIES OF CHILLY NIGHTS BUT RELATIVELY MILD DAYS. OUR NEXT CHANCE FOR RAIN WILL WAIT UNTIL SATURDAY NIGHT AND SUNDAY. && .UPDATE... ISSUED AT 811 AM EDT TUE APR 3 2012 INITIAL BATCH OF SHWRS EXITED INTO LAKE HURON BY 6 AM. THE ENHANCED STRATIFORM AREA OF -RA WAS OVER LAKE MI AND WILL MOVE INTO NW LOWER MI IN THE NEXT HOUR. SINCE MCS WAS OVER CENTRAL WI AT TIME OF 313 AM FCST ISSUANCE...UNCERTAINTY HAS DIMINISHED ON ITS ARRIVAL. SO POPS WERE INCREASED TO 100% AND HAVE TIMED THIS THRU NRN LOWER PENINSULA. IF IT HOLDS TOGETHER...THE BACK EDGE SHOULD BE OFFSHORE INTO LAKE HURON NO LATER THAN 2 PM. THUNDER: THE BEST ARC OF ELEVATED INSTABILITY IS S OF M-55. BUT THE M-55 CORRIDOR HAS THE "BEST" CHC FOR THUNDER. WE SEE THE NEW SHWRS GOING UP OVER MANISTEE/WEXFORD COUNTIES. THAT OFFERS BETTER POTENTIAL THAN THE STRATIFORM AREA. A TENTH OF LIQUID WAS MEASURED AT STURGEON WI...ON THE W COAST OF LAKE MI IN THE PAST HOUR. SO A FEW HUNDREDTHS WILL FALL. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 QUITE AN AMPLIFIED PATTERN ONGOING OVER THE WESTERN HEMISPHERE EARLY THIS MORNING...WITH LARGE SCALE TROUGHS ANCHORED ALONG BOTH COASTS OF NOAM WITH A REX BLOCK-LIKE FEATURE STUCK BETWEEN THESE...KEEPING THE WEATHER SOMEWHAT INTERESTING OVER WHAT WOULD OTHERWISE BE LARGE-SCALE RIDGING. THE FOCUS FOR THE NEAR TERM AND THROUGH TODAY IS SHOWER AND THUNDERSTORM POTENTIAL AS INVERTED TROUGH PULLS INTO THE REGION FROM THE WEST. OVERNIGHT...SHOWERS AND THUNDERSTORMS HAVE MADE THE MOST OF VERY MEAGER INSTABILITY...CONTINUOUSLY FIRING ALONG THE H85 MOISTURE BOUNDARY AS IT PUSHES EAST INTO THE REGION. THROUGH DAYBREAK...I EXPECT AREAS FROM M-32 NORTH TO SEE SOME SHRA ACTIVITY /WITH A FEW EMBEDDED RUMBLES/...WITH A FEW MORE SHOWERS DOWN NEAR MANISTEE. THINGS GET TRICKIER AS WE HEAD INTO THE DAY TODAY...WITH THE IMPACTS OF ANOTHER CONVECTIVE COMPLEX NOW OVER WESTERN WISCONSIN NOT SO CERTAIN. CORFIDI VECTORS SUGGEST THAT THIS COMPLEX WILL PUSH EAST AND THEN SOUTHEAST...OVER THE TOP OF THE H5 RIDGE AXIS...WHICH WOULD SUGGEST ARRIVAL NEAR MY SOUTHWEST ZONES TOWARDS 12Z. THE HRRR IS ON BOARD WITH THIS...AS IS OUR PREVIOUS GRIDDED FORECAST AND WILL CONTINUE EARLY MORNING LIKELY POPS BASICALLY SOUTH OF M-72 AND WEST OF INTERSTATE 75. GIVEN THE TIME OF DAY...EXPECT THIS COMPLEX TO DIE AS IT MOVES EAST...WITH LITTLE TO HANG YOUR HAT ON FOR FORCING FOR THE REMAINDER OF THE DAY AS AFOREMENTIONED INVERTED TROUGH INCREASES LOW LEVEL CONVERGENCE TO SOME EXTENT. STILL...WITH MOIST PLUME OVERHEAD...AND CVA FROM WAVE NOW MOVING INTO WESTERN ONTARIO...EXPECT SOME ADDITIONAL SHOWERS TO POP UP ALONG THE H85 COLD FRONT AS IT SAGS THROUGH THE REGION THIS AFTERNOON. CONFIDENCE IS PRETTY LOW IN HOW THIS EVOLVES THIS AFTERNOON...AND THAT IS WHY I/LL KEEP POPS IN THE CHANCE CATEGORY. TEMPERATURES LIKELY WON/T MAKE TOO MUCH PROGRESS GIVEN CLOUD COVER. REALLY LIKED INHERITED HIGHS IN THE LOWER 50S /WITH A FEW MID 50S OVER SOUTHERN AREAS/ AND WILL CONTINUE THEM IN THIS PACKAGE. THIS IS TOWARDS THE COOLER END OF THE GUIDANCE ENVELOPE. TONIGHT...DRIER AIR PUSHES INTO THE REGION AS INVERTED TROUGH SCOOTS TO THE SOUTHEAST OF THE AREA WITH DEEP LAYER NORTHWEST FLOW DEVELOPING. THIS SHOULD SCOUR OUT ANY REMNANT LOW LEVEL MOISTURE...BRINGING CLEARING SKIES. WITH WINDS LIKELY TO REMAIN COUPLED...I DON/T EXPECT LOWS TO FALL ALL THAT FAR...WITH FAIRLY HOMOGENEOUS VALUES NEAR OR A LITTLE ABOVE 30 EXPECTED. WEDNESDAY...EXPANSIVE AREA OF HIGH PRESSURE BUILDS SOUTH INTO THE HUDSON BAY REGION WITH DRY NORTHWESTERLY FLOW VEERING NORTHERLY DURING THE DAY UNDER CONTINUED COLD ADVECTION. GIVEN VERY DRY ARRIVING AIRMASS...EXPECT A SUNNY/MSUNNY DAY WITH AMPLE SUBSIDENCE TO ENSURE LITTLE IN THE WAY OF CUMULUS DEVELOPMENT. WITH THE AFOREMENTIONED SUBSIDENCE...WOULDN/T BE SURPRISED IF WE DON/T MIX QUITE AS HIGH AS THE MODELS ARE ADVERTISING...AND UNDER COLD ADVECTION FEEL TEMPS WILL STRUGGLE A LITTLE. THEREFORE...WILL FOLLOW CLOSER TO THE COOLER SIDE OF THE GUIDANCE ENVELOPE /MET/ WITH HIGHS IN THE MID 40S OVER EASTERN UPPER...TO THE LOWER 50S OVER NORTHERN LOWER. GIVEN THE FLOW TRAJECTORIES AND SUBSIDENT FLOW...EXPECT A VERY DRY AIRMASS WITH DEWPOINTS LIKELY TUMBLING INTO THE UPPER TEENS BY MID/LATE AFTERNOON. THIS WILL BRING MINIMUM RH/S INTO THE 20S. WITH GUSTY NORTH/NORTHWEST WINDS...WILL CONTINUE ELEVATED FIRE DANGER WORDING IN THE MORNING HWO...BUT TEMPERATURES WILL BE WELL BELOW RED FLAG LEVELS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 UPPER PATTERN REMAINS ONLY VERY SLOWLY PROGRESSIVE THRU THE REST OF THE WORK WEEK AND INTO THE WEEKEND. THAT WILL STILL EVENTUALLY BRING THE PAC NW UPPER TROF EASTWARD INTO OUR REGION...BUT LIKELY NOT UNTIL THE END OF THE WEEKEND. BEFORE THEN...THURSDAY/FRIDAY/SATURDAY CONTINUE TO LOOK RELATIVELY UNEVENTFUL...WITH SURFACE HIGH PRESSURE ENTRENCHED IN THE GREAT LAKES REGION. WED NIGHT-SAT...A REASONABLY VIGOROUS SHORTWAVE DROPS SOUTH ACROSS THE NORTHERN LAKES WED NIGHT. THIS SYSTEM IS MOISTURE-STARVED...AND WILL BRING NO MORE THAN SOME MID-HIGH CLOUDS...PRIMARILY TO EASTERN UPPER AND NE LOWER MI. HOWEVER...IT WILL PUSH A SECONDARY COLD FRONT ACROSS THE AREA...HELPING TO MAINTAIN 850MB TEMPS IN THE -6 TO -8C RANGE BY THU MORNING. WARM ADVECTION (ON N TO NE LOW LEVEL FLOW) AND AIRMASS MODIFICATION BEGIN SHORTLY THEREAFTER. BUT WE WILL STILL SEE SOMEWHAT COOLISH TEMPS...ESPECIALLY WED NIGHT AND THU NIGHT. EXPECT MINS MAINLY IN THE 20S...AND COULD DEFINITELY SEE TEENS IN THE USUAL COLD INTERIOR LOCALES. GIVEN OUR EARLY START TO THE GROWING SEASON...FROST/FREEZE HEADLINES COULD WELL BE NEEDED ON BOTH NIGHTS. WE/LL SEE ENOUGH SUN TO KEEP MAX TEMPS RESPECTABLE THURSDAY...MID 40S TO AROUND 50. RH LEVELS WILL BE PRETTY LOW DESPITE THE COOLISH TEMPS...WITH DEW POINTS IN THE TEENS (PERHAPS LOWER) AT PEAK HEATING. FOR NOW...IT LOOKS LIKE WE WON/T QUITE HAVE ENOUGH OF A NORTHERLY BREEZE TO MAKE FOR AN ENHANCED FIRE THREAT DAY. HIGH PRESSURE MOVES OVERHEAD BY FRIDAY...AND THE AIRMASS WILL CONTINUE TO MODERATE. MAX TEMPS WILL JUMP INTO THE 50S FRIDAY...AND WILL APPROACH 60F IN SPOTS SATURDAY...WITH PLENTY OF SUNSHINE. AFTER A DAY WITH HARDLY ANY WIND FRIDAY...A DEVELOPING SOUTHERLY BREEZE SATURDAY COULD ALSO PRODUCE AN ENHANCED FIRE THREAT...THOUGH FOR NOW (LIKE THURSDAY) FORECAST WINDS AREN/T QUITE STRONG ENOUGH. LATER PERIODS...TIMING AGREEMENT REMAINS DECENT ON LOW PRESSURE LIFTING TOWARD HUDSON BAY SAT NIGHT/SUNDAY...AND AN ASSOCIATED COLD FRONT CROSSING MI LATE SAT NIGHT/SUNDAY MORNING. CHANCE POPS STILL IN ORDER WAY OUT THEN. DEPENDING ON YOUR MODEL SOLUTION OF CHOICE... MAY HAVE ENOUGH COOL AIR AND DEEP CYCLONIC FLOW TO PRODUCE A CHANCE FOR RAIN/SNOW SHOWERS ON MONDAY. THE OPERATIONAL GFS IS AMONGST THE CHILLIEST/MOST MOIST BY MONDAY...IT HAS BEEN KNOWN TO OVERDUE THESE SORTS OF THINGS FROM TIME TO TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 811 AM EDT TUE APR 3 2012 TODAY: ONE-HOUR BATCH OF VFR -RA WILL ADVANCE ACROSS THE TAF SITES. CLOUDS WILL BE MULTI-LAYERED. WINDS WILL BE LIGHT FROM THE SE THRU 17Z /THO AT TIMES VARIABLE DIR/. THEN AN ABRUPT WSHFT TO WNW-NW WITH AN INCREASE TO 10 KTS WITH SOME GUSTINESS TO 16 KTS. PKWND COULD BE AS HIGH AS 20 KTS BRIEFLY. AFTER WSHFT...THERE IS SOME POTENTIAL FOR A 1-3 HOUR WINDOW OF MVFR CIGS. THEY OVER CURRENTLY OVER NW WI...BUT CONFIDENCE IS NOT HIGH ENUF TO INCLUDE IN THIS TAF ISSUANCE. TNGT: RAPID CLEARING 23-01Z. LIGHT NW WINDS 5 KTS OR LESS. && .MARINE... ISSUED AT 313 AM EDT TUE APR 3 2012 WINDS/WAVES LOOK TO GENERALLY REMAIN BELOW LEVELS HAZARDOUS TO SMALL CRAFT THROUGH TUESDAY NIGHT AS TROUGH OF LOW PRESSURE MOVES THROUGH THE REGION TODAY WITH NORTHWESTERLY WINDS DEVELOPING LATE THIS AFTERNOON AND TONIGHT. THESE NORTHWESTERLY WINDS WILL STRENGTHEN ON WEDNESDAY AS CANADIAN HIGH PRESSURE BUILDS TOWARDS THE REGION. THIS WILL LIKELY BRING A PERIOD OF SMALL CRAFT CONDITIONS ON WEDNESDAY BEFORE THE AFORMENTIONED HIGH SETTLES OVERHEAD WITH QUIET CONDITIONS FOR THE END OF THE WEEK. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...HALBLAUB SYNOPSIS...JZ SHORT TERM...JA LONG TERM....JZ AVIATION...HALBLAUB MARINE...JA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
745 AM EDT TUE APR 3 2012 .SYNOPSIS... ISSUED AT 533 AM EDT TUE APR 3 2012 RIDGE OVER THE AREA SINCE LATE IN THE WEEKEND IS BEING FLATTENED OUT THIS MORNING AS STRONG SHORTWAVE TROUGH SLIDES FM MANITOBA INTO NORTHWEST ONTARIO. HEIGHT FALLS ARE SUBTLE OVR UPR LAKES PER 00Z RAOBS BUT ENOUGH TO TRIGGER MULTIPLE CLUSTERS OF SHRA/TSRA OVR THE UPPER GREAT LAKES. FRONTAL BOUNDARY...EXTENDING SOUTH OUT OF LOW OVR NORTHERN ONTARIO AND ALSO EXTENDING TO THE NORTH FM LOW OVR MID MISSISSIPI RIVER VALLEY WILL CROSS UPR MICHIGAN THIS MORNING. COOLER AIRMASS ADVECTS OVR THE AREA LATER TODAY THROUGH TONIGHT AND WEDNESDAY. AFTER THE FROPA THIS MORNING...DRY WEATHER WILL PREVAIL THROUGH LATE THIS WEEK AS LARGE HIGH PRESSURE IS DOMINANT WEATHER FEATURE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 533 AM EDT TUE APR 3 2012 TODAY...CONVECTIVE TRENDS WILL BE CHALLENGING THIS MORNING...BUT AFTER THAT DRYING TREND WILL FIRMLY TAKE HOLD. AS OCCURRED 24 HR AGO...MAIN AREA OF CONVECTION OVERNIGHT HAS DEVELOPED CLOSER TO H7 MOIST AXIS AND ALSO IN AREA OF H85 TEMP ADVECTION. INITIAL SHRA/TSRA HEADING QUICKLY INTO THE FAR EAST CWA FORMED AHEAD OF ONTARIO SHORTWAVE TROUGH AND HAVE BEHAVED FOLLOWING STEADY EASTWARD MOTION. CONVECTION OVR MN AND WESTERN WI IS OUTLINED WELL BY WHERE RUC13 SHOWS MAXIMUM H7 MOISTURE TRANSPORT AND ON NORTHERN EDGE OF STEEPER H7-H5 LAPSE RATES AOA 8C/KM. AT THIS TIME...MAJORITY OF TSRA ARE OCCURRING OVR CNTRL WI BUT ADDITIONAL SHRA WITH EMBEDDED TSRA ARE FILLING IN INTO NORTHWEST WI. FOLLOWING RUC IDEA THERE IS ENOUGH H7 MOISTURE TRANSPORT INTO SCNTRL CWA TO KEEP HIGHER POPS THERE IN THE MORNING. A FEW SHRA/TSRA MAY EVEN CLIP AREAS FARTHER NORTH IN THE CNTRL CWA BUT IT IS FAIRLY LIMITED CHANCE AS THE AREA OF SHRA/TSRA OVR NORTHWEST WI WILL BE OUTRUNNING BETTER H7 MOISTURE CONVERGENCE AND ELEVATED INSTABILITY IF THEY CONTINUE ON ENE TRACK. OVERALL IMAGINE CHANCES OF CONVECTION WILL BEGIN TO WANE SIGNIFICANTLY OVR MOST AREAS AFTER MID MORNING /POST 15Z-16Z/ SINCE SFC FRONT WILL BE DROPPING S/SE OF THE AREA BY THAT TIME. HAVE HAD SOME PEA-SIZED HAIL OVERNIGHT WITH STRONGER STORMS AND THAT REMAINS POSSIBLE THIS MORNING GIVEN STEEP LAPSE RATES JUST UPSTREAM AND 30-35 KTS OF EFFECTIVE SHEAR FCST OVR CNTRL PORTIONS OF UPR MI. AS ALLUDED TO BEFORE...COLD FRONT WILL STEADILY SLIDE ACROSS THE AREA MID TO LATE MORNING. WINDS IN WAKE OF FRONT EXPECTED TO BECOME NORTH TO NORTHWEST. STILL APPEARS THAT THERE COULD BE BRIEF PERIOD OF LOWER CIGS AND MAYBE SOME FOG AS HIGHER DWPNTS JUST BEHIND FRONT SETTLE ACROSS LK SUPERIOR AND WINDS PROVIDE SOME UPSLOPE LIFTING OVR HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL CWA. POSSIBILITY FOR FOG MAY HAVE BEEN ENHANCED DUE TO THE DECENT COVERAGE OF SHRA/TSRA OVR LK SUPERIOR OVERNIGHT THAT MAY HAVE PROVIDED ADDITIONAL LOW-LEVEL MOISTENING. LOOKING UPSTREAM THERE IS AREA OF LOWER CLOUDS NORTHWEST OF LK SUPERIOR BUT THERE IS ALSO A MUCH LARGER AREA OF VERY DRY AIR/CLEAR SKIES PUSHING ACROSS MANITOBA AND NORTHWEST ONTARIO. REALLY HARD TO TELL AT THIS POINT HOW MUCH/IF ANY FOG IS PRESENT OVR WESTERN LK SUPERIOR...SO WILL NOT INCLUDE IN FCST FOR LATER THIS MORNING. EXPECT DRYING TO WIN OUT PRETTY EASILY AFTER MID AFTN ONCE BLYR DWPNTS FALL INTO THE LOWER 30S/MID-UPR 20S AS HIGH BEGINS TO NOSE INTO LK SUPERIOR REGION. SO SKY FCST SHAKES OUT AS FAIRLY CLOUDY IN THE MORNING BUT WITH FAIRLY SHARP CLEARING TREND BY MID AFTN FM WEST-TO-EAST. DESPITE THE SUNSHINE THIS AFTN...TEMPS SHOULD BE HELD DOWN MOST AREAS WITH GRADIENT WIND FLOWING OFF LK SUPERIOR. PROBABLY WILL SEE STEADY TEMPS ALONG LK SUPERIOR AND READINGS PUSHING INTO LOWER 50S FAR INLAND/LK MICHIGAN SHORE WITH LESS LAKE MODIFICATION GIVEN THE NORTHWEST WINDS. DWPNTS AND RH VALUES COULD CRASH OVR INTERIOR WEST BY LATE AFTN. CURRENT FCST HAS RH VALUES IN THE 30-40 PCT RANGE...BUT IF WINDS STAY MORE NW IT COULD GET WARMER WHICH WOULD RESULT IN RH VALUES BLO 30 PCT. VERY DRY AIRMASS BECOMES FIRMLY ENTRENCHED OVR AREA TONIGHT INTO WEDNESDAY AS HIGH PRESSURE BUILDS FM HUDSON BAY INTO THE WESTERN GREAT LAKES. NORTHERLY FLOW REMAINS OFF LK SUPERIOR BUT GIVEN PWATS FALLING TOWARD 50 PCT OF NORMAL...EXPECT INTERIOR CWA TO TRY TO DECOUPLE TONIGHT AND COOL OFF TOWARD THE LOWER DWPNTS ADVECTING INTO THE REGION. BENEATH MOSTLY SUNNY SKIES ON WEDNESDAY...MAIN CONCERN WILL BE ON FIRE WX WITH LOWER RH VALUES. HAVE DWPNTS IN AFTN MIXING OUT INTO THE UPR TEENS OVR INTERIOR SECTIONS...RESULTING IN RH VALUES BLO 30 PCT. WINDS WILL NOT BE VERY GUSTY /LEADING TO LESS IMPACT ON FIRE WX CUSTOMERS/ BUT A STEADY NORTH WIND UP TO 15 MPH IS EXPECTED. GIVEN THE FLOW...PROBABLY WILL HAVE TOUGH TIME REACHING 40 DEGREES ALONG LK SUPERIOR SHORE. MIXING HEIGHTS MUCH HIGHER TOWARD WI BORDER /H85-H8 PER FCST SOUNDINGS/ ALLOW TEMPS TO RISE WELL INTO THE 50S. OVERALL LOOKS LIKE PRETTY TYPICAL SPRING PATTERN. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 533 AM EDT TUE APR 3 2012 HIGH PRESSURE WILL DOMINATE MUCH OF THIS PERIOD. WHILE THE SFC RIDGE WILL BE OVERHEAD AT 00Z THURSDAY...THE MAIN HIGH WILL LIKELY RESIDE OVER HUDSON BAY AND NW ONTARIO. EXPECT THE CENTER OF HIGH PRESSURE TO SLOWLY SIDE OVER LAKE SUPERIOR THURSDAY INTO FRIDAY. DRY AIR WILL CONTINUE TO SLIDE INTO THE AREA FROM EASTERN ONTARIO...WITH HUMIDITY VALUES FALLING 25 TO 25 PERCENT THURSDAY AND FRIDAY AFTERNOON AWAY FROM THE LAKE SUPERIOR COASTLINE. ON THE PLUS SIDE...WINDS SHOULD BE FAIRLY LIGHT...LESS THAN 10KTS AWAY FROM ANY LAKE BREEZES THAT MAY COME IN THURSDAY AND FRIDAY AFTERNOON. STILL...IT WILL BE ENOUGH TO INCREASE FIRE WEATHER CONCERNS OVER UPPER MICHIGAN THROUGH THE REMAINDER OF THE WORK WEEK. THERE WILL BE A SUBTLE CHANGE FRIDAY...AS THE HIGH PRESSURE SYSTEM BEGINS TO SHIFT EASTWARD IN RESPONSE TO A SFC LOW ORGANIZING OVER EASTERN WY/MT INTO THE WESTERN DAKOTAS. LOOK FOR A SLOW RETURN TO S/SE WINDS FRIDAY INTO FRIDAY NIGHT. THE PRESSURE GRADIENT WILL TIGHTEN OVER THE WEEKEND. EXPECT INCREASED S/SE WINDS OF 10 TO 15KTS SATURDAY /AHEAD OF THE COLD FRONT CROSSING SATURDAY NIGHT/. SPECIFICS FOR THIS PERIOD ARE A LITTLE TRICKY...WITH THE BREAKDOWN OF THE 500MB RIDGE SATURDAY NIGHT AS THE MAIN LOW REMAINS WELL TO OUR NORTH. THE 03/00Z RUN OF THE ECMWF CONTINUES TO SHOW LIMITED MOISTURE...WITH LITTLE MORE THAN A TRACE OF RAIN FALLING SATURDAY NIGHT AS MUCH OF THE ENERGY REMAINS WRAPPED UP ACROSS CANADA MAINLY ON THE BACK SIDE OF THE LOW. THE 03/00Z RUN OF THE GFS ON THE OTHER HAND INDICATES THE POTENTIAL FOR AROUND A TENTH OF AN INCH OF WELL NEEDED RAIN...WITH STILL THE BEST CHANCE BEHIND THE LOW. GIVEN THE LOW POTENTIAL FOR EVEN RAIN...KEPT ONLY SLIGHT CHANCE TS IN THE FCST FOR SATURDAY AFTERNOON INTO SATURDAY NIGHT. WINDS WILL REMAIN STRONGER ON THE ORDER OF 15 TO 20KTS OUT OF THE W BEHIND THE COLD FRONT AS THE SFC LOW SHIFTS FROM NEAR LAKE WINNIPEG AT 12Z SATURDAY...TO NORTHERN ONTARIO/HUDSON BAY ON SUNDAY. NO SIGNIFICANT WARM UP IS IN SIGHT...WITH 850MB TEMPS HOVERING AROUND 0C SUNDAY WITH TEMPS FALLING TO AROUND -8C MONDAY AFTERNOON ON N-NW WINDS OFF LAKE SUPERIOR. DID NOT GO WITH FALLING SFC TEMPS FOR MONDAY QUITE YET...EVEN THOUGH BOTH THE GFS AND ECMWF LOOK FAIRLY CONSISTENT WITH THIS IDEA. AS NOTED IN THE PREVIOUS DISCUSSION...WRAP AROUND MOISTURE LOOKS TO BET BEHIND THE LOW...PARTICULARLY IN NW FLOW OFF LAKE SUPERIOR CAN LINGER OVER THE CWA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 744 AM EDT TUE APR 3 2012 AREA OF SHOWERS ALONG FRONTAL BOUNDARY WILL WORK ACROSS CNTRL UPR MI THROUGH MID MORNING AFFECTING THE SAW TAF SITE. ONCE THE FRONT PASSES THROUGH TAF SITES EXPECT WINDS TO SHIFT TO A MORE NORTH TO NORTHWEST DIRECTION AND FOR CIGS TO DROP TO MVFR AT IWD AND CMX...AND POSSIBLY AT SAW AS WELL THOUGH NW WINDS ARE NOT AS FAVORABLE. BASED ON SOME OBSERVATIONS SHOWING IFR CIGS IN NORTHERN MN HAVE OPTED TO INCLUDE MENTION OF IFR CIGS AT CMX BY LATE MORNING WITH UPSLOPE NORTHWEST WINDS. STILL NOT SURE IF THERE IS MUCH FOG OVR WESTERN LK SUPERIOR...BUT IF FOG DID FORM THEN THERE COULD BE A BRIEF PERIOD OF VSBY REDUCTION /MAYBE INTO THE IFR RANGE/ WITH THE IFR CIGS. TOO MUCH UNCERTAINTY TO PUT THAT IN TAF ATTM...BUT CANNOT RULE THIS OUT YET. EVENTUALLY...DEEP DRYING WILL SWEEP THROUGH ALL TAF SITES LATE THIS AFTN WITH GUSTY NORTH WINDS. VFR CONDITIONS THEN EXPECTED TONIGHT WITH DIMINISHING WINDS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 533 AM EDT TUE APR 3 2012 WINDS SHOULD REMAIN LESS THAN 30KTS THROUGH THE PERIOD...GETTING NEAR THIS LEVEL W AND CENTRAL SUNDAY AFTERNOON OFF WSW WINDS. IN THE SHORTER TERM...A TROUGH OF LOW PRESSURE OVER CENTRAL AND EASTERN LAKE SUPERIOR WILL EXIT ACROSS LAKE HURON THIS EVENING. THIS WILL MAKE WAY FOR LARGE HIGH PRESSURE OVER CENTRAL CANADA AND THE NORTHERN PLAINS TO SHIFT DIRECTLY OVER THE UPPER GREAT LAKES WEDNESDAY AFTERNOON...WHERE IT WILL REMAIN THROUGH FRIDAY. A LOW DEVELOPING OVER MANITOBA AND NORTH DAKOTA SATURDAY MORNING WILL SLIDE OVER NORTHERN LAKE SUPERIOR AND ONTARIO SATURDAY NIGHT INTO SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLA SHORT TERM...JLA LONG TERM...KF AVIATION...JLA MARINE...KF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
721 AM CDT TUE APR 3 2012 .UPDATE...JUST UPDATED FORECAST TO BRING THINGS IN LINE WITH THE LATEST TRENDS FOR TODAY...AND ALSO TO DROP PRE-FIRST PERIOD WORDING IN ZFP PRODUCT. WHAT WAS A NARROW LINE OF THUNDERSTORMS A FEW HOURS AGO LIFTING NORTH OUT OF KS INTO SOUTHERN NEB HAS SINCE FADED AWAY INTO A BENIGN LINE OF SPRINKLES CENTERED OVER THE SHERMAN-DAWSON COUNTY AREA. ALTHOUGH NOT EXPECTING THIS TO REMAIN IN THE CWA MUCH LONGER...OPTED TO GO AHEAD AND EXPAND A SPRINKLE MENTION THROUGH THE DAY TO ALL AREAS THAT DIDNT ALREADY HAVE A MEASURABLE POP. MAIN FAIRLY MINOR CHANGE FROM ORIGINAL FORECAST ISSUANCE WAS TO PULL ISOLATED THUNDER MENTION COMPLETELY THIS MORNING...BUT WILL HOLD ONTO THAT MENTION FOR THE AFTERNOON ALTHOUGH CONFIDENCE IS LOW. ALSO...EXPANDED A MEASURABLE SLIGHT POP TO MOST OF THE WESTERN CWA FOR THIS AFTERNOON TO ACCOUNT FOR HINTS OF A BIT MORE ISOLATED SHOWER ACTIVITY THAN EARLIER EXPECTED PER THE 09Z HRRR. OTHERWISE...MAIN THEME OF FORECAST REMAINS INTACT...IN THAT THE MAIN SHOW RAIN WISE WILL HOLD OFF UNTIL TONIGHT INTO TOMORROW. MADE NO CHANGES TO TODAYS HIGH TEMPERATURE GRID AT THIS TIME. && .PREV DISCUSSION... /ISSUED 533 AM CDT TUE APR 3 2012/ AVIATION...12Z TAF. A NARROW LINE OF RAIN SHOWERS AND A HIT OR MISS LIGHTNING STRIKE WAS LIFTING TO THE NORTH AND WEST TOWARD INTERSTATE 80 EARLY THIS MORNING WITH PROGRESSION BEGINNING TO SLOWER WITH DRIER AIR TO THE NORTH. HAVE NOT INCLUDED ANY PCPN IN KGRI TAF EARLY THIS MORNING AS EXPECTATION IS THAT ACTIVITY WILL REMAIN TO THE SOUTH. CLOUDS WILL HOLD FIRM WITH OVERCAST CONDITIONS EXPECTED THRU THE ENTIRE 24HR TAF DURATION. CIGS ATTM ARE BORDERLINE BETWEEN IFR AND MVFR AND EXPECT MAINLY PREVAILING MVFR CIGS OVERALL. AN UPPER LOW PRESSURE SYSTEM WILL EDGE TOWARD WEST TEXAS THRU TONIGHT AND RAIN SHOWERS WILL BEGIN TO SPREAD NORTH TOWARD NEBRASKA OVERNIGHT. KGRI WILL BE ON THE NORTHERN EDGE OF THE RAINFALL TOWARD 12Z. PREV DISCUSSION... /ISSUED 355 AM CDT TUE APR 3 2012/ SHORT TERM...THROUGH THURSDAY NIGHT. PRIMARY CHALLENGE OVER THE NEXT 72 HOURS IS CLEARLY RAINFALL TRENDS/AMOUNTS...AS THE MID LEVEL LOW CURRENTLY CENTERED OVER EASTERN NEW MEXICO GRADUALLY LUMBERS EASTWARD NEAR THE OK/KS BORDER...AND EVENTUALLY INTO THE MID-SOUTH BY THURSDAY. CERTAINLY PARTS OF THE CWA ARE GOING TO SEE SOME WELL-TIMED BENEFICIAL RAINS IN EXCESS OF 0.75-INCH. ALSO NOT GOING TO SEE MUCH SUNSHINE FOR THE NEXT FEW DAYS. STARTING OFF EARLY THIS MORNING...08Z OBJECTIVE SURFACE ANALYSIS SHOWS THE CWA LOCATED WELL NORTH OF THE PRIMARY SURFACE COLD FRONT STRETCHED NORTHEAST ACROSS SOUTHEAST KANSAS FROM A FAIRLY WEAK LOW OVER THE TX PANHANDLE. WELL OFF TO THE NORTHWEST...A BROAD...ROUGHLY 1025 MB HIGH PRESSURE SYSTEM IS CENTERED ACROSS THE NORTHERN ROCKIES INTO ND. WITH THE CWA POSITIONED WITHIN THE HEART OF THE MAIN NORTH-SOUTH SURFACE PRESSURE GRADIENT...STEADY NORTH WINDS HAVE PREVAILED ALL NIGHT...WITH SUSTAINED SPEEDS COMMONLY 20-30 MPH WITH HIGHER GUSTS...BUT GENERALLY FALLING SHORT OF WIND ADVISORY CRITERIA IN MOST PLACES. RADAR...11-3.9 MICRON SATELLITE IMAGERY AND AUTOMATED OBS DEPICT A CORRIDOR OF WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS CENTERED OVER CENTRAL/NORTHWEST KANSAS...WITH SOME OF THIS ACTIVITY STARTING TO INCREASINGLY AFFECT AREAS MAINLY SOUTHWEST OF A BEAVER CITY-BELOIT LINE. AS FOR RAINFALL AMOUNTS IN THE PAST 12 HOURS...RADAR ESTIMATES THAT POCKETS OF THE SOUTHERN CWA...MAINLY THE KS COUNTIES...HAVE LIKELY TALLIED BETWEEN 0.25-0.50 INCH...ALTHOUGH MOST AREAS PROBABLY LESS. OTHERWISE...AN EXPANSIVE AREA OF LOW STRATUS MAINLY IN THE 800-1800 FT RANGE HAS OVERTAKEN THE ENTIRE CWA...WITH JUST A HINT OF LIGHT DRIZZLE IN THE AIR HERE AT THE WFO. UP TOP...WATER VAPOR SATELLITE CLEARLY DEPICTS THE AFOREMENTIONED CLOSED LOW CENTERED NEAR THE NM/TX BORDER...WHILE A RATHER PRONOUNCED RIDGE DOMINATES MUCH OF THE EASTERN CONUS. GETTING TO THE FORECAST AND STARTING WITH TODAY...IMMEDIATE SHORT TERM ISSUE OVER THE NEXT 4-6 HOURS IS PROGRESSION OF NEXT BATCH OF GENERALLY WEAK CONVECTION RIDING UP INTO SOUTHERN ZONES. WILL BE ISSUING A PRE-FIRST PERIOD ZONE FORECAST PACKAGE...WITH LIKELY POPS THROUGH 12Z FOR LOCATIONS MAINLY SOUTH OF A BEAVER CITY- BELOIT LINE. WITH RUC ADVERTISING AT LEAST 500 J/KG MUCAPE IN THESE AREAS...OCCASIONAL SMALL HAIL AND BRIEF BUT FREQUENT LIGHTNING STRIKES CERTAINLY ARE POSSIBLE EARLY THIS MORNING. OTHERWISE...FOLLOWING LATEST HRRR REFLECTIVITY PROGS...ALONG WITH 00Z 4KM WRF-NMM....MUCH OF THIS ACTIVITY SHOULD DECREASE IN COVERAGE...AND FAIL TO PUSH VERY FAR INTO THE NEB CWA OVER THE NEXT FEW HOURS AS THE SMALL SCALE SHORTWAVE CURRENTLY OVER NORTHWEST KS ROTATES BACK MORE TO THE WEST-NORTHWEST. MOVING ON TO THE DAYTIME 12Z-00Z TIME FRAME...ASSUMING THAT THE CURRENT CONVECTION DISSIPATES OR MOVES OUT BY AROUND SUNRISE...REALLY NOT EXPECTING A WHOLE LOT OF PRECIP POTENTIAL FOR THE MAJORITY OF THE CWA...AS THE LOCAL AREA REMAINS IN A BIT OF A LULL IN BETWEEN PUSHES OF MID/UPPER FORCING...WAITING FOR THE NEXT PRIMARY CHUNK OF ENERGY TO ROTATE NORTHWARD OUT OF THE SOUTHERN PLAINS AHEAD OF THE UPPER LOW. AS A RESULT...ACTUALLY HAVE NO PRECIPITATION MENTIONED WHATSOEVER ACROSS ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH THE DAY...AND ONLY 20-50 PERCENT POPS ACROSS SOUTHWEST ZONES...WITH EVEN THIS POTENTIALLY BEING TOO MUCH. EVEN IN AREAS WITH NO EXPECTATION OF MEASURABLE PRECIP...SUPPOSE SOME PATCHY DRIZZLE COULD CONTINUE PAST SUNRISE...BUT WILL LEAVE IT OUT FOR NOW AND TAKE ANOTHER LOOK ON UPDATE IN A FEW HOURS. IF ANY CONVECTION DOES SURVIVE/MOVE IN DURING THE DAY...ISOLATED THUNDER POTENTIAL IS CERTAINLY THERE WITH CONTINUED MUCAPE AVERAGING GENERALLY BELOW 500 J/KG...BUT POSSIBLY COULD BE ENOUGH TO GENERATE SOME SMALL HAIL. AS FOR HIGH TEMPS TODAY...FEEL THAT AT LEAST SLIGHTLY UNDERCUTTING MET/MAV GUIDANCE CONSENSUS IS THE WAY TO GO...AS LOW CLOUDS AND STEADY NORTHERLY BREEZES OF 15-25 MPH WILL PERSIST THROUGH THE DAY. MAY STILL BE TOO WARM IN SPOTS...BUT FOR NOW WILL AIM FOR MID-UPPER 50S IN MOST WESTERN AREAS...AND MAYBE SOME LOW 60S IN THE EAST. IN STARK CONTRAST TO THE PAST SEVERAL WEEKS...THESE HIGHS WOULD BE VERY NEAR IF NOT SLIGHTLY BELOW NORMAL FOR A CHANGE. THIS EVENING/TONIGHT...THIS IS WHEN LEGITIMATE WIDESPREAD RAINFALL WILL RAMP UP...BUT MAINLY ACROSS THE SOUTHERN 1/2 OF THE CWA. IN SHORT...UPPER DIVERGENCE INCREASES TO THE NORTH OF THE PARENT MID LEVEL LOW...WHICH WILL BE CENTERED GENERALLY OVER THE OK PANHANDLE. IN RESPONSE...A CLASSIC...GENERALLY EAST-WEST BAND OF STEADY SHOWERS AND POSSIBLY SOME EMBEDDED WEAK THUNDERSTORMS WILL GRADUALLY LIFT NORTH ACROSS KS THIS EVENING...AND HAVE POPS PRIOR TO 06Z RANGING FROM ONLY 20 PERCENT NEAR KGRI...TO 90 PERCENT IN MOST OF NORTH CENTRAL KS WHERE THE MAIN PRECIP AXIS WILL SET UP. FOR THE LATE NIGHT PERIOD...THEN HAVE HIGH 70-90 POPS EXPANDING NORTHWARD OUT OF KS INTO MUCH OF SOUTH CENTRAL NEB...BUT MAINLY SOUTH OF I-80. GIVEN TRENDS OF LATEST 06Z NAM...ALONG WITH 4KM WRF-NMM...AM STARTING TO WONDER IF NORTHERN COUNTIES SUCH AS VALLEY/NANCE ETC. WILL SEE MUCH OF ANYTHING BEFORE SUNRISE WED MORNING...AND A TIGHTER POP GRADIENT BETWEEN THE HAVES AND HAVE NOTS MAY PROVE NECESSARY. AS FOR RAINFALL AMOUNTS...EXPECT AT LEAST THE SOUTHERN 1/2 TO 1/3 OF THE CWA TO MEASURE BETWEEN 0.25-0.75 INCH OVERNIGHT...WITH LOCALLY HIGHER AMOUNTS POSSIBLE...AND AGAIN...A FAIRLY SHARP CUTOFF LIKELY SOMEWHERE NEAR I-80. ALTHOUGH CERTAINLY NOT EXPECTING SEVERE WEATHER...WILL KEEP ISOLATED THUNDER MENTION OVERNIGHT MAINLY ACROSS THE SOUTHERN 1/3 OF THE CWA...BUT EVEN SMALL HAIL SHOULD BE HARD TO COME BY. WEDNESDAY...FAIRLY WIDESPREAD RAIN SHOWERS WILL CONTINUE AS THE PARENT MID LEVEL CIRCULATION TRAVERSES EASTWARD NEAR OR JUST SOUTH OF THE KS/OK BORDER. KEPT A BROAD AREA OF LIKELY POPS GOING CWA- WIDE THROUGH THE DAY...ALTHOUGH LATEST NAM/ECWMF CONTINUE TO SUGGEST THAT THE NORTHERN 1/4 OR SO OF THE CWA...GENERALLY NORTH OF HWY 92...COULD STRUGGLE TO SEE MUCH...AND POPS IN THESE AREAS INCLUDING ORD/GREELEY MAY NEED TONED DOWN IN LATER FORECASTS. WITH WIDESPREAD CLOUDS/ONGOING PRECIP...LOWERED HIGH TEMPS 2-4 DEGREES IN MOST AREAS FROM PREVIOUS FORECAST...WITH ONLY LOW-MID 50S MOST AREAS. WEDNESDAY NIGHT...SHOWERS SHOULD GRADUALLY END FROM NORTHWEST- SOUTHEAST AS THE PARENT LOW PROGRESSES TO NEAR THE OK/AR BORDER...AND IT MAY VERY WELL END UP THAT MOST OF THE CWA...ESPECIALLY THE NORTHWEST 1/2...COULD STAY HIGH AND DRY THROUGH THE NIGHT. FOR NOW THOUGH WILL CONTINUE 20-40 POPS CWA-WIDE. THURSDAY...WILL CONTINUE TO KEEP IT DRY...RUNNING WITH THE ASSUMPTION THAT THE DEPARTING SYSTEM SHOULD BE FAR ENOUGH AWAY...ALTHOUGH SUPPOSE A FEW LIGHT WRAP AROUND SHOWERS COULD FLIRT WITH PARTS OF THE KS CWA. WITH AT LEAST PARTIAL SUNSHINE EXPECTED TO RETURN...TEMPS ARE FORECAST TO REBOUND BACK INTO THE LOW-MID 60S FOR HIGHS...BUT AM STAYING JUST BELOW THE MET/MAV GUIDANCE BLEND FOR NOW. AS SURFACE HIGH PRESSURE SLIDES EAST .EAST-SOUTHEAST WINDS WILL PICK UP A BIT AS THE DAY WEARS ON. THURSDAY NIGHT...WILL ALSO MAINTAIN A DRY FORECAST...ALTHOUGH BOTH THE NAM/GFS ARE DEPICTING CONSIDERABLE LOW LEVEL SATURATION AND POSSIBLE DRIZZLE POTENTIAL MAINLY ACROSS WESTERN NEB/KS...BUT FOR NOW MOST IF NOT ALL OF THIS POTENTIAL LOOKS TO REMAIN WEST OF THE CWA THROUGH THE NIGHT. ALTHOUGH NOT IN THE FORECAST GRIDS AT THIS TIME...SUPPOSE SOME FOG REDUCING VISIBILITY AT LEAST INTO THE 1-2 MILE RANGE IS POSSIBLE ACROSS PARTS OF THE AREA EACH OF THE NEXT 3 NIGHTS...BUT WITH PRECIP GENERALLY EXPECTED TO BE FAIRLY WIDESPREAD AT LEAST THE NEXT 2 NIGHTS...NOT LOOKING LIKE AN OBVIOUS SETUP FOR WIDESPREAD...IMPACTFUL FOG. IN CLOSING...THIS SYSTEM WILL UNDOUBTEDLY BE A BENEFICIAL RAINER IN MANY AREAS...HELPING MAKE UP FOR A MARCH PRECIP DEFICIT. HOWEVER...THERE WILL LIKELY BE A SHARP NORTH-SOUTH RANGE IN RAINFALL AMOUNTS OVER THE NEXT 24-48 HOURS...WITH CURRENT FORECAST GRIDS AIMING FOR TOTALS RANGING FROM AT LEAST 1 TO 1.5 INCHES FOR MOST AREAS NEAR/SOUTH OF I-80...BUT ONLY 0.25-0.50 INCH...AND MAYBE NOT EVEN THAT MUCH...FOR SOME NORTHERN COUNTIES. LONG TERM...FRIDAY THROUGH MONDAY. BEGINNING ON FRIDAY AN UPPER LOW IS FORECAST TO BE CENTERED IN THE PACIFIC NW WITH TROUGH AXIS EXTENDING THRU THE CENTRAL ROCKIES. IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS...SFC TROUGH DEEPENS ALONG THE HIGH PLAINS. AS SFC GRADIENT TIGHTENS SOUTHERLY WINDS WILL INCREASE WITH BREEZY CONDITIONS SETTING UP BY AFTN AND MOISTURE WILL WORK NORTHWARD WITH DPS RISING DURING THE AFTN. ALTHOUGH MAIN FORCING WILL ARRIVE FRIDAY NIGHT AS UPPER SYSTEM LIFTS ACROSS THE NORTHERN PLAINS AND ASSOCIATED COLD FRONT CROSS OUR REGION...MODELS DO INDICATE SOME THETA E ADVECTION FRIDAY AHEAD OF SYSTEM AND WILL MAINTAIN OUR CURRENT LOW POPS DURING THE DAY FRIDAY. AS FRONT CROSSES FRIDAY NIGHT THERE IS A NARROW AXIS OF INSTABILITY ALONG/AHEAD OF BOUNDARY...MUCAPES NEARING 1000 J/KG...AND COULD POTENTIALLY SEE A STRONG STORM OR TWO. EASTER WEEKEND IS SHAPING UP TO BE DRY AND SEASONAL OVERALL. A 1030MB SURFACE HIGH BUILDS SOUTH BEING THE FRONT AND SETTLES ACROSS THE CENTRAL PLAINS OVERNIGHT. SFC DPS ARE PROGGED TO DROP TO THE TEENS IN OUR NW WITH 20S IN THE SOUTHEAST IN THE DRY AIRMASS. LOOKING LIKE A MUCH COLDER NIGHT THAN WE HAVE HAD RECENTLY HOWEVER NOT NECESSARILY UNUSUAL FOR THIS TIME OF YEAR WITH NORMAL LOWS IN THE LOW/MID 30S. FORECAST LOWS ARE IN THE 30S IN GENERAL AND AGREE PREVIOUS SHIFTS THAT THIS PERIOD WILL NEED TO BE MONITORED FOR FROST/FREEZE POTENTIAL. SURFACE RIDGE AXIS SLIPS SOUTHEAST ON SUNDAY WITH RETURN FLOW SETTING UP DURING THE DAY. ANOTHER COLD FRONT CROSSES THE PLAINS SUNDAY NIGHT/MONDAY ASSOCIATED WITH UPPER LOW IN ONTARIO AND TROUGH EXTENDING ACROSS THE UPPER MIDWEST/OHIO VALLEY REGION. BRUNT OF COLD AIR REMAINS EAST OF THE MISSOURI RIVER...HOWEVER SOME COOLER AIR DOES BACK INTO OUR NORTHEAST COUNTIES. THIS BEING SAID...ALTHOUGH HIGHS MAY DROP A DEGREE OR TWO FROM SUNDAY...TEMPS OVERALL ARE STILL LOOKING SEASONAL OR SLIGHTLY ABOVE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE/SHORT TERM...PFANNKUCH LONG TERM/AVIATION...CF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
533 AM CDT TUE APR 3 2012 .AVIATION...12Z TAF. A NARROW LINE OF RAIN SHOWERS AND A HIT OR MISS LIGHTNING STRIKE WAS LIFTING TO THE NORTH AND WEST TOWARD INTERSTATE 80 EARLY THIS MORNING WITH PROGRESSION BEGINNING TO SLOWER WITH DRIER AIR TO THE NORTH. HAVE NOT INCLUDED ANY PCPN IN KGRI TAF EARLY THIS MORNING AS EXPECTATION IS THAT ACTIVITY WILL REMAIN TO THE SOUTH. CLOUDS WILL HOLD FIRM WITH OVERCAST CONDITIONS EXPECTED THRU THE ENTIRE 24HR TAF DURATION. CIGS ATTM ARE BORDERLINE BETWEEN IFR AND MVFR AND EXPECT MAINLY PREVAILING MVFR CIGS OVERALL. AN UPPER LOW PRESSURE SYSTEM WILL EDGE TOWARD WEST TEXAS THRU TONIGHT AND RAIN SHOWERS WILL BEGIN TO SPREAD NORTH TOWARD NEBRASKA OVERNIGHT. KGRI WILL BE ON THE NORTHERN EDGE OF THE RAINFALL TOWARD 12Z. && .PREV DISCUSSION... /ISSUED 355 AM CDT TUE APR 3 2012/ SHORT TERM...THROUGH THURSDAY NIGHT. PRIMARY CHALLENGE OVER THE NEXT 72 HOURS IS CLEARLY RAINFALL TRENDS/AMOUNTS...AS THE MID LEVEL LOW CURRENTLY CENTERED OVER EASTERN NEW MEXICO GRADUALLY LUMBERS EASTWARD NEAR THE OK/KS BORDER...AND EVENTUALLY INTO THE MID-SOUTH BY THURSDAY. CERTAINLY PARTS OF THE CWA ARE GOING TO SEE SOME WELL-TIMED BENEFICIAL RAINS IN EXCESS OF 0.75-INCH. ALSO NOT GOING TO SEE MUCH SUNSHINE FOR THE NEXT FEW DAYS. STARTING OFF EARLY THIS MORNING...08Z OBJECTIVE SURFACE ANALYSIS SHOWS THE CWA LOCATED WELL NORTH OF THE PRIMARY SURFACE COLD FRONT STRETCHED NORTHEAST ACROSS SOUTHEAST KANSAS FROM A FAIRLY WEAK LOW OVER THE TX PANHANDLE. WELL OFF TO THE NORTHWEST...A BROAD...ROUGHLY 1025 MB HIGH PRESSURE SYSTEM IS CENTERED ACROSS THE NORTHERN ROCKIES INTO ND. WITH THE CWA POSITIONED WITHIN THE HEART OF THE MAIN NORTH-SOUTH SURFACE PRESSURE GRADIENT...STEADY NORTH WINDS HAVE PREVAILED ALL NIGHT...WITH SUSTAINED SPEEDS COMMONLY 20-30 MPH WITH HIGHER GUSTS...BUT GENERALLY FALLING SHORT OF WIND ADVISORY CRITERIA IN MOST PLACES. RADAR...11-3.9 MICRON SATELLITE IMAGERY AND AUTOMATED OBS DEPICT A CORRIDOR OF WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS CENTERED OVER CENTRAL/NORTHWEST KANSAS...WITH SOME OF THIS ACTIVITY STARTING TO INCREASINGLY AFFECT AREAS MAINLY SOUTHWEST OF A BEAVER CITY-BELOIT LINE. AS FOR RAINFALL AMOUNTS IN THE PAST 12 HOURS...RADAR ESTIMATES THAT POCKETS OF THE SOUTHERN CWA...MAINLY THE KS COUNTIES...HAVE LIKELY TALLIED BETWEEN 0.25-0.50 INCH...ALTHOUGH MOST AREAS PROBABLY LESS. OTHERWISE...AN EXPANSIVE AREA OF LOW STRATUS MAINLY IN THE 800-1800 FT RANGE HAS OVERTAKEN THE ENTIRE CWA...WITH JUST A HINT OF LIGHT DRIZZLE IN THE AIR HERE AT THE WFO. UP TOP...WATER VAPOR SATELLITE CLEARLY DEPICTS THE AFOREMENTIONED CLOSED LOW CENTERED NEAR THE NM/TX BORDER...WHILE A RATHER PRONOUNCED RIDGE DOMINATES MUCH OF THE EASTERN CONUS. GETTING TO THE FORECAST AND STARTING WITH TODAY...IMMEDIATE SHORT TERM ISSUE OVER THE NEXT 4-6 HOURS IS PROGRESSION OF NEXT BATCH OF GENERALLY WEAK CONVECTION RIDING UP INTO SOUTHERN ZONES. WILL BE ISSUING A PRE-FIRST PERIOD ZONE FORECAST PACKAGE...WITH LIKELY POPS THROUGH 12Z FOR LOCATIONS MAINLY SOUTH OF A BEAVER CITY- BELOIT LINE. WITH RUC ADVERTISING AT LEAST 500 J/KG MUCAPE IN THESE AREAS...OCCASIONAL SMALL HAIL AND BRIEF BUT FREQUENT LIGHTNING STRIKES CERTAINLY ARE POSSIBLE EARLY THIS MORNING. OTHERWISE...FOLLOWING LATEST HRRR REFLECTIVITY PROGS...ALONG WITH 00Z 4KM WRF-NMM....MUCH OF THIS ACTIVITY SHOULD DECREASE IN COVERAGE...AND FAIL TO PUSH VERY FAR INTO THE NEB CWA OVER THE NEXT FEW HOURS AS THE SMALL SCALE SHORTWAVE CURRENTLY OVER NORTHWEST KS ROTATES BACK MORE TO THE WEST-NORTHWEST. MOVING ON TO THE DAYTIME 12Z-00Z TIME FRAME...ASSUMING THAT THE CURRENT CONVECTION DISSIPATES OR MOVES OUT BY AROUND SUNRISE...REALLY NOT EXPECTING A WHOLE LOT OF PRECIP POTENTIAL FOR THE MAJORITY OF THE CWA...AS THE LOCAL AREA REMAINS IN A BIT OF A LULL IN BETWEEN PUSHES OF MID/UPPER FORCING...WAITING FOR THE NEXT PRIMARY CHUNK OF ENERGY TO ROTATE NORTHWARD OUT OF THE SOUTHERN PLAINS AHEAD OF THE UPPER LOW. AS A RESULT...ACTUALLY HAVE NO PRECIPITATION MENTIONED WHATSOEVER ACROSS ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH THE DAY...AND ONLY 20-50 PERCENT POPS ACROSS SOUTHWEST ZONES...WITH EVEN THIS POTENTIALLY BEING TOO MUCH. EVEN IN AREAS WITH NO EXPECTATION OF MEASURABLE PRECIP...SUPPOSE SOME PATCHY DRIZZLE COULD CONTINUE PAST SUNRISE...BUT WILL LEAVE IT OUT FOR NOW AND TAKE ANOTHER LOOK ON UPDATE IN A FEW HOURS. IF ANY CONVECTION DOES SURVIVE/MOVE IN DURING THE DAY...ISOLATED THUNDER POTENTIAL IS CERTAINLY THERE WITH CONTINUED MUCAPE AVERAGING GENERALLY BELOW 500 J/KG...BUT POSSIBLY COULD BE ENOUGH TO GENERATE SOME SMALL HAIL. AS FOR HIGH TEMPS TODAY...FEEL THAT AT LEAST SLIGHTLY UNDERCUTTING MET/MAV GUIDANCE CONSENSUS IS THE WAY TO GO...AS LOW CLOUDS AND STEADY NORTHERLY BREEZES OF 15-25 MPH WILL PERSIST THROUGH THE DAY. MAY STILL BE TOO WARM IN SPOTS...BUT FOR NOW WILL AIM FOR MID-UPPER 50S IN MOST WESTERN AREAS...AND MAYBE SOME LOW 60S IN THE EAST. IN STARK CONTRAST TO THE PAST SEVERAL WEEKS...THESE HIGHS WOULD BE VERY NEAR IF NOT SLIGHTLY BELOW NORMAL FOR A CHANGE. THIS EVENING/TONIGHT...THIS IS WHEN LEGITIMATE WIDESPREAD RAINFALL WILL RAMP UP...BUT MAINLY ACROSS THE SOUTHERN 1/2 OF THE CWA. IN SHORT...UPPER DIVERGENCE INCREASES TO THE NORTH OF THE PARENT MID LEVEL LOW...WHICH WILL BE CENTERED GENERALLY OVER THE OK PANHANDLE. IN RESPONSE...A CLASSIC...GENERALLY EAST-WEST BAND OF STEADY SHOWERS AND POSSIBLY SOME EMBEDDED WEAK THUNDERSTORMS WILL GRADUALLY LIFT NORTH ACROSS KS THIS EVENING...AND HAVE POPS PRIOR TO 06Z RANGING FROM ONLY 20 PERCENT NEAR KGRI...TO 90 PERCENT IN MOST OF NORTH CENTRAL KS WHERE THE MAIN PRECIP AXIS WILL SET UP. FOR THE LATE NIGHT PERIOD...THEN HAVE HIGH 70-90 POPS EXPANDING NORTHWARD OUT OF KS INTO MUCH OF SOUTH CENTRAL NEB...BUT MAINLY SOUTH OF I-80. GIVEN TRENDS OF LATEST 06Z NAM...ALONG WITH 4KM WRF-NMM...AM STARTING TO WONDER IF NORTHERN COUNTIES SUCH AS VALLEY/NANCE ETC. WILL SEE MUCH OF ANYTHING BEFORE SUNRISE WED MORNING...AND A TIGHTER POP GRADIENT BETWEEN THE HAVES AND HAVE NOTS MAY PROVE NECESSARY. AS FOR RAINFALL AMOUNTS...EXPECT AT LEAST THE SOUTHERN 1/2 TO 1/3 OF THE CWA TO MEASURE BETWEEN 0.25-0.75 INCH OVERNIGHT...WITH LOCALLY HIGHER AMOUNTS POSSIBLE...AND AGAIN...A FAIRLY SHARP CUTOFF LIKELY SOMEWHERE NEAR I-80. ALTHOUGH CERTAINLY NOT EXPECTING SEVERE WEATHER...WILL KEEP ISOLATED THUNDER MENTION OVERNIGHT MAINLY ACROSS THE SOUTHERN 1/3 OF THE CWA...BUT EVEN SMALL HAIL SHOULD BE HARD TO COME BY. WEDNESDAY...FAIRLY WIDESPREAD RAIN SHOWERS WILL CONTINUE AS THE PARENT MID LEVEL CIRCULATION TRAVERSES EASTWARD NEAR OR JUST SOUTH OF THE KS/OK BORDER. KEPT A BROAD AREA OF LIKELY POPS GOING CWA- WIDE THROUGH THE DAY...ALTHOUGH LATEST NAM/ECWMF CONTINUE TO SUGGEST THAT THE NORTHERN 1/4 OR SO OF THE CWA...GENERALLY NORTH OF HWY 92...COULD STRUGGLE TO SEE MUCH...AND POPS IN THESE AREAS INCLUDING ORD/GREELEY MAY NEED TONED DOWN IN LATER FORECASTS. WITH WIDESPREAD CLOUDS/ONGOING PRECIP...LOWERED HIGH TEMPS 2-4 DEGREES IN MOST AREAS FROM PREVIOUS FORECAST...WITH ONLY LOW-MID 50S MOST AREAS. WEDNESDAY NIGHT...SHOWERS SHOULD GRADUALLY END FROM NORTHWEST- SOUTHEAST AS THE PARENT LOW PROGRESSES TO NEAR THE OK/AR BORDER...AND IT MAY VERY WELL END UP THAT MOST OF THE CWA...ESPECIALLY THE NORTHWEST 1/2...COULD STAY HIGH AND DRY THROUGH THE NIGHT. FOR NOW THOUGH WILL CONTINUE 20-40 POPS CWA-WIDE. THURSDAY...WILL CONTINUE TO KEEP IT DRY...RUNNING WITH THE ASSUMPTION THAT THE DEPARTING SYSTEM SHOULD BE FAR ENOUGH AWAY...ALTHOUGH SUPPOSE A FEW LIGHT WRAP AROUND SHOWERS COULD FLIRT WITH PARTS OF THE KS CWA. WITH AT LEAST PARTIAL SUNSHINE EXPECTED TO RETURN...TEMPS ARE FORECAST TO REBOUND BACK INTO THE LOW-MID 60S FOR HIGHS...BUT AM STAYING JUST BELOW THE MET/MAV GUIDANCE BLEND FOR NOW. AS SURFACE HIGH PRESSURE SLIDES EAST ..EAST-SOUTHEAST WINDS WILL PICK UP A BIT AS THE DAY WEARS ON. THURSDAY NIGHT...WILL ALSO MAINTAIN A DRY FORECAST...ALTHOUGH BOTH THE NAM/GFS ARE DEPICTING CONSIDERABLE LOW LEVEL SATURATION AND POSSIBLE DRIZZLE POTENTIAL MAINLY ACROSS WESTERN NEB/KS...BUT FOR NOW MOST IF NOT ALL OF THIS POTENTIAL LOOKS TO REMAIN WEST OF THE CWA THROUGH THE NIGHT. ALTHOUGH NOT IN THE FORECAST GRIDS AT THIS TIME...SUPPOSE SOME FOG REDUCING VISIBILITY AT LEAST INTO THE 1-2 MILE RANGE IS POSSIBLE ACROSS PARTS OF THE AREA EACH OF THE NEXT 3 NIGHTS...BUT WITH PRECIP GENERALLY EXPECTED TO BE FAIRLY WIDESPREAD AT LEAST THE NEXT 2 NIGHTS...NOT LOOKING LIKE AN OBVIOUS SETUP FOR WIDESPREAD...IMPACTFUL FOG. IN CLOSING...THIS SYSTEM WILL UNDOUBTEDLY BE A BENEFICIAL RAINER IN MANY AREAS...HELPING MAKE UP FOR A MARCH PRECIP DEFICIT. HOWEVER...THERE WILL LIKELY BE A SHARP NORTH-SOUTH RANGE IN RAINFALL AMOUNTS OVER THE NEXT 24-48 HOURS...WITH CURRENT FORECAST GRIDS AIMING FOR TOTALS RANGING FROM AT LEAST 1 TO 1.5 INCHES FOR MOST AREAS NEAR/SOUTH OF I-80...BUT ONLY 0.25-0.50 INCH...AND MAYBE NOT EVEN THAT MUCH...FOR SOME NORTHERN COUNTIES. LONG TERM...FRIDAY THROUGH MONDAY. BEGINNING ON FRIDAY AN UPPER LOW IS FORECAST TO BE CENTERED IN THE PACIFIC NW WITH TROUGH AXIS EXTENDING THRU THE CENTRAL ROCKIES. IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS...SFC TROUGH DEEPENS ALONG THE HIGH PLAINS. AS SFC GRADIENT TIGHTENS SOUTHERLY WINDS WILL INCREASE WITH BREEZY CONDITIONS SETTING UP BY AFTN AND MOISTURE WILL WORK NORTHWARD WITH DPS RISING DURING THE AFTN. ALTHOUGH MAIN FORCING WILL ARRIVE FRIDAY NIGHT AS UPPER SYSTEM LIFTS ACROSS THE NORTHERN PLAINS AND ASSOCIATED COLD FRONT CROSS OUR REGION...MODELS DO INDICATE SOME THETA E ADVECTION FRIDAY AHEAD OF SYSTEM AND WILL MAINTAIN OUR CURRENT LOW POPS DURING THE DAY FRIDAY. AS FRONT CROSSES FRIDAY NIGHT THERE IS A NARROW AXIS OF INSTABILITY ALONG/AHEAD OF BOUNDARY...MUCAPES NEARING 1000 J/KG...AND COULD POTENTIALLY SEE A STRONG STORM OR TWO. EASTER WEEKEND IS SHAPING UP TO BE DRY AND SEASONAL OVERALL. A 1030MB SURFACE HIGH BUILDS SOUTH BEING THE FRONT AND SETTLES ACROSS THE CENTRAL PLAINS OVERNIGHT. SFC DPS ARE PROGGED TO DROP TO THE TEENS IN OUR NW WITH 20S IN THE SOUTHEAST IN THE DRY AIRMASS. LOOKING LIKE A MUCH COLDER NIGHT THAN WE HAVE HAD RECENTLY HOWEVER NOT NECESSARILY UNUSUAL FOR THIS TIME OF YEAR WITH NORMAL LOWS IN THE LOW/MID 30S. FORECAST LOWS ARE IN THE 30S IN GENERAL AND AGREE PREVIOUS SHIFTS THAT THIS PERIOD WILL NEED TO BE MONITORED FOR FROST/FREEZE POTENTIAL. SURFACE RIDGE AXIS SLIPS SOUTHEAST ON SUNDAY WITH RETURN FLOW SETTING UP DURING THE DAY. ANOTHER COLD FRONT CROSSES THE PLAINS SUNDAY NIGHT/MONDAY ASSOCIATED WITH UPPER LOW IN ONTARIO AND TROUGH EXTENDING ACROSS THE UPPER MIDWEST/OHIO VALLEY REGION. BRUNT OF COLD AIR REMAINS EAST OF THE MISSOURI RIVER...HOWEVER SOME COOLER AIR DOES BACK INTO OUR NORTHEAST COUNTIES. THIS BEING SAID...ALTHOUGH HIGHS MAY DROP A DEGREE OR TWO FROM SUNDAY...TEMPS OVERALL ARE STILL LOOKING SEASONAL OR SLIGHTLY ABOVE. PREV DISCUSSION... /ISSUED 1214 AM CDT TUE APR 3 2012/ AVIATION...06Z TAF. THE TAF PERIOD WILL BE MARKED WITH FAIRLY WINDY CONDITIONS IN RESPONSE TO A TIGHT PRESSURE GRADIENT FOLLOWING THE PASSAGE OF A COLD FRONT ON MONDAY. NORTHERLY WINDS WILL AVERAGE 20KTS OR SO AND GUST NEAR 30KTS. WINDS WILL TRANSITION NORTHEASTERLY TUESDAY AFTERNOON AND ALTHOUGH STILL BREEZY...WIND SPEEDS WILL GRADUALLY DECREASE AS THE GRADIENT RELAXES. IT LOOKS LIKE PRECIPITATION WILL HOLD OFF UNTIL BEYOND THE TAF PERIOD UNTIL THE SOUTHERN PLAINS LOW LIFTS FARTHER NORTH. CLOUD COVER FOR THE MOST PART SHOULD BE IN THE MVFR CATEGORY ALTHOUGH SOME IFR CIGS ARE POSSIBLE TUESDAY MORNING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM/AVIATION...CF
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
954 AM CDT TUE APR 3 2012 .DISCUSSION... LOW/MID LEVEL CLOUD DECK REMAINS ENTRENCHED ACROSS SOUTHEASTERN SOUTH DAKOTA AND BORDERING STATES THIS MORNING. 925-850MB RUC RH PROGS INDICATE EROSION OF THIS DECK SHOULD CONTINUE INTO THE EARLY AFTERNOON...ALTHOUGH EXPECT SOME RESIDUAL SCATTERED LOW/MID CLOUDS UNTIL EVENING. TEMPS STILL LOOK TO BE COOLEST IN THE SOUTHEASTERN CWA UNDER THE INFLUENCE OF THE CLOUD COVER...ALTHOUGH ABOVE NORMAL HIGHS IN THE UPPER 50S TO LOWER 60S ARE STILL ANTICIPATED. BRISK NORTHEAST WINDS WILL PERSIST THROUGH THE AFTERNOON...BUT REDUCE BELOW 10 KTS AFTER DARK. && .PREV DISCUSSION... /ISSUED 440 AM CDT MON APR 3 2012/ A DECK OF LOW AND MID LEVEL STRATUS BEHIND THE SURFACE COLD FRONT CURRENTLY ENCOMPASSES MUCH OF THE AREA. SEEING A FEW LIGHT SHOWERS IN THE VICINITY OF THE 700MB FRONT...BUT THINK THESE WILL DISSIPATE BY 12Z. MAIN FORECAST ISSUE TODAY WILL BE THE ERODING OF THE CLOUD DECK AND THE ACCOMPANYING IMPACT ON HIGH TEMPERATURES. THE COMBINATION OF DAYTIME HEATING AND LOW LEVEL DRY AIR ADVECTING IN FROM THE NORTH SHOULD ACT TO SLOWLY RISE CEILINGS AND DISSIPATE THE CLOUDS FROM NORTH TO SOUTH THROUGH THE DAY. FOLLOWED A SOLUTION CLOSE TO HRRR...WHICH SEEMS TO HAVE A FAIRLY GOOD HANDLE ON THINGS. 925MB TEMPS LOOK TO BE AROUND 12C THIS AFTERNOON. THUS LOCATIONS THAT BECOME PARTLY TO MOSTLY SUNNY SHOULD GET INTO THE LOW 60S. MEANWHILE...LOCATIONS THAT GET STUCK IN THE CLOUDS WILL LIKELY REMAIN IN THE 50S. NORTHWEST IOWA AND PORTIONS OF SOUTHWEST MINNESOTA ARE THE MOST LIKELY LOCATIONS TO STAY LOCKED IN. WENT FOR HIGHS AROUND 60 IN THIS AREA GIVEN UNCERTAINTY...BUT WHERE THE CLOUDS STAY...MAY NOT REACH 60. THINKING THE WARMEST TEMPS WILL BE JUST NORTH OF THE CLOUD DECK THIS AFTERNOON...IN THE MITCHEL TO LAKE ANDES AREA...THUS RAISED HIGHS SEVERAL DEGREES THERE. WINDS WILL BE BLUSTERY TODAY OUT OF THE NORTHEAST. 900MB WINDS OF 20 TO 25KTS WILL PROMOTE WIND GUSTS UP TO AROUND 30 MPH THROUGH MUCH OF THE DAY. MOST LOCATIONS WILL BE MOSTLY CLEAR TONIGHT...EXCEPT ALONG AND SOUTH OF THE MISSOURI RIVER...WHERE CLOUDS MAY STAY LOCKED IN. HOWEVER NOT THINKING IT WILL BE A GREAT RADIATIONAL COOLING NIGHT WITH A 925MB JET OF AROUND 30KTS KEEPING THE LOW LEVELS SOMEWHAT MIXED. THUS DID NOT GO AS COLD AT THE MET GUIDANCE. DID GO ON THE COOLER SIDE OF THE RAW GUIDANCE THOUGH...WITH THE COOL EAST NORTHEAST WIND ADVECTING IN SOME COLDER AIR IN THE LOW LEVELS. NEXT FORECAST ISSUE IS THE UPPER LEVEL LOW PRESSURE SYSTEM THAT WILL MOVE ACROSS OKLAHOMA ON WEDNESDAY. THIS FURTHER SOUTH TRACK KEEPS THE BEST FORCING TO OUR SOUTH. AT THE SAME TIME...EAST NORTHEAST WINDS AROUND AN AREA OF HIGH PRESSURE OVER SOUTHERN CANADA WILL PUSH DRIER AIR INTO OUR CWA. THE COMBINATION OF THESE FACTORS SHOULD KEEP ALL THE PRECIP TO OUR SOUTH WITH THIS SYSTEM...AND THUS REMOVED POPS. THIS IS SUPPORTED BY THE NAM...ECMWF AND SREF SOLUTIONS. HIGHS WEDNESDAY WERE TRENDED WARMER GIVEN THE DRIER AND MORE SUNNY FORECAST...GENERALLY GOING WITH UPPER 50S TO LOWER 60S. WEDNESDAY NIGHT IS ANOTHER NIGHT WHICH WILL FEATURE A COOL EASTERLY COMPONENT TO THE WIND. THUS WENT ON THE COLDER SIDE OF THE RAW GUIDANCE...BUT NOT AS COLD AS MOS...WHICH APPEARS TO BE RADIATING THINGS TOO MICH. NEXT WEATHER FEATURE WILL BE A SHORTWAVE THAT CROSSES THE REGION FRIDAY NIGHT INTO SATURDAY. BEST QG FORCING WITH THIS FEATURE WILL STAY TO OUR NORTH AND ANY INSTABILITY TO OUR SOUTH. SO THINKING ANY RAIN WE GET FROM THIS WAVE WILL BE LIGHT. GIVEN THIS JUST KEPT POPS IN THE CHANCE CATEGORY FOR NOW. GIVEN THE VERY MEAGER INSTABILITY DECIDED TO REMOVE THE THUNDER WORDING FROM THE GRIDS. THE REST OF THE FORECAST PERIOD SHOULD REMAIN DRY. ECMWF IS SLOWER WITH OUR NEXT COLD FRONT THAN THE GFS...ALLOWING TEMPERATURES TO WARM NICELY ON SUNDAY. ECMWF ENSEMBLE NOT QUITE AS SLOW AND WARM AS THE OPERATIONAL...BUT STILL WARMER THAN THE GFS...THUS UPPED TEMPS A FEW DEGREES INTO THE LOW TO MID 60S. MODELS AGREE THAT THE COLDEST AIR BEHIND THE FRONT WILL BE OVER US ON MONDAY INTO MONDAY NIGHT. HOWEVER THE GFS DIGS THE TROUGH FURTHER SOUTH PUSHING IN COLDER AIR THAN THE ECMWF. ECMWF AND GFS ENSEMBLES ARE BOTH SEVERAL DEGREES WARMER THAN THEIR OPERATIONAL RUNS AT 850MB. THUS TEND TO THINK THIS WILL JUST BE A QUICK COLD SHOT WITH RIDGING QUICKLY BUILDING IN BEHIND IT ONCE AGAIN. CURRENTLY GOING WITH HIGHS IN THE 50S MONDAY...BUT GIVEN WHAT WAS JUST MENTIONED...WOULD NOT BE SURPRISED TO SEE FUTURE SHIFTS TREND THESE UP A BIT...CLOSER TO THE ECMWF VALUES. EITHER WAY...STILL WILL HAVE A CHILLY ATMOSPHERE OVER US MONDAY NIGHT...WHICH COMBINED WITH SURFACE HIGH PRESSURE OVERHEAD...SHOULD PROMOTE GOOD RADIATIONAL COOLING...AND WILL HAVE TO WATCH FOR A POSSIBLE FREEZE OVER MUCH OF THE AREA. /CHENARD && .AVIATION.../FOR THE 12Z TAF ISSUANCE/ THIS MORNING...THERE WILL BE AREAS OF MVFR CEILINGS EXCEPT IN OUR NW ZONES WHO ARE CURRENTLY CLEARING OUT. BY MIDDAY...MOST OF THE MVFR CEILINGS SHOULD BE GONE...EITHER BY MIXING TO A VFR CATEGORY...OR BY CLEARING OUT ENTIRELY. THEREFORE THIS AFTERNOON AND TONIGHT...OUR FORECAST AREA SHOULD BE VFR. NORTHERLY WINDS WILL GUST AT TIMES TO AROUND 25 KNOTS TODAY...BECOMING A BIT MORE NORTHEAST THIS AFTERNOON. /MJF && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
701 AM CDT TUE APR 3 2012 .DISCUSSION... SEE 12Z AVIATION DISCUSSION BELOW. && .AVIATION... GENERALLY A VFR FORECAST TODAY WITH TEMPO MVFR CONDITIONS ASSOCIATED WITH CONVECTION THIS MORNING. LIGHT WEST TO NORTHWEST WINDS EARLY THIS MORNING WILL GUST TO AROUND 20 KT AFTER 17Z...THEN DIMINISH BY SUNSET. VFR CONDITIONS WILL PREVAIL OVERNIGHT WITH LIGHT WINDS. && .PREV DISCUSSION... /ISSUED 357 AM CDT TUE APR 3 2012/ SHORT TERM... POTENT UPPER LOW OVER NEW MEXICO WILL SLOWLY MOVE EAST INTO THE TEXAS HANDLE TONIGHT. PACIFIC FRONT HAS PUSHED EAST OF A JUNCTION... BRADY... ABILENE...HASKELL LINE. IT WAS STILL UNSTABLE ALONG AND AHEAD OF THE FRONT WITH RUC MUCAPES OF 2000 J/KG AND 0-6 KM SHEARS OF 40 KTS. CAN NOT RULE OUT AN ISOLATED SEVERE THUNDERSTORMS EAST OF THE PACIFIC FRONT THIS MORNING. HOWEVER...DRIER WESTERLY AIR AT THIS SURFACE WILL WORK EASTWARD BY NOON...ENDING THE SEVERE THREAT. THERE AS OUTSIDE CHANCE OF A SHOWER...AS 700 MB MOISTURE WAS WRAPPED AROUND THE UPPER THIS MORNING ACROSS WEST TEXAS. THIS IS EXPECTED TO MOVE NORTH OF THE REGION BY EARLY AFTERNOON. OTHERWISE...DRY DESERT AIR AT THE SURFACE WILL BE GUSTY AT TIMES THIS AFTERNOON...ELEVATING FIRE WEATHER CONDITIONS. LONG TERM... GUSTY WEST WINDS WILL AGAIN ELEVATE FIRE CONDITIONS WEDNESDAY AS SURFACE LOW IN NW TEXAS MOVES NE INTO CENTRAL OKLAHOMA. COOL AIR FILTERS IN WEDNESDAY NIGHT AS A WEAK COLD FRONT MOVES INTO THE REGION. LATER THIS WEEK...THERE IS STILL THE POTENTIAL FOR DRYLINE THUNDERSTORMS FRIDAY NIGHT. A COLD FRONT SATURDAY WILL ALSO BRING A CHANCE FOR THUNDERSTORMS...MAINLY SOUTH OF THE I-20 CORRIDOR. ADDED SLIGHT CHANCE OF STORMS SATURDAY NIGHT AND SUNDAY WITH LIFT OF MOISTURE OVER THE FRONT. CONFIDENCE REMAINS LOW HOWEVER SO KEPT POPS AT 20 PERCENT. FIRE WEATHER. GUSTY DRY WEST WINDS WILL ELEVATED FIRE DANGER THIS AFTERNOON AND WEDNESDAY AFTERNOON...AS A SURFACE LOW IN NW TEXAS MOVES INTO CENTRAL OKLAHOMA. WINDS SPEEDS ARE EXPECTED TO REMAIN BELOW CRITICAL LEVELS. 04 && .PRELIMINARY POINT TEMPS/POPS... ABILENE 79 50 81 49 83 / 20 10 0 0 0 SAN ANGELO 82 47 85 49 90 / 20 10 0 0 0 JUNCTION 81 46 87 48 91 / 20 10 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99/24
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
649 AM CDT TUE APR 3 2012 .UPDATE... 649 AM CDT TUE APR 3 2012 HAVE HAD A FEW SHOWERS AND THUNDERSTORMS POP UP IN THE LAST 45 MINUTES FROM THE DECORAH AREA TO LA CROSSE. THE ONE STORM NEAR DECORAH ENDED UP PRODUCING PEA SIZE HAIL. THESE APPEAR TO BE ON AN 850MB FRONT. 03.10Z RUC FORECAST SOUNDINGS ON THIS FRONT ARE HIGHLY UNFAVORABLE FOR PRECIPITATION...AND WITH MOST MODELS NOT SUGGESTING PRECIPITATION...ONLY GUESS IS THAT THERE MUST BE A LITTLE MORE MOISTURE AROUND 750MB THAN FORECAST. IF YOU MODIFY A RUC SOUNDING TO SATURATE 750MB AND COOL THE TEMPERATURE ACCORDINGLY...UP TO 700 J/KG OF CAPE IS AVAILABLE. HARD TO SAY EXACTLY HOW LONG THE PRECIPITATION WILL LAST...BUT IF THE ENVIRONMENT THE RUC SUGGESTS IS MOSTLY CORRECT...THEY WILL HAVE A HARD TIME LASTING MORE THAN A FEW HOURS. THEREFORE...ONLY HAVE CHANCES IN UNTIL 14Z. .SHORT TERM...TODAY THROUGH THURSDAY 349 AM CDT TUE APR 3 2012 MAIN FORECAST CONCERNS ARE ON RAIN CHANCES OVER CENTRAL WISCONSIN THIS MORNING. FOCUS THEN TURNS TO TEMPERATURES TONIGHT THROUGH THURSDAY NIGHT...WITH THE POTENTIAL FOR OVERNIGHT LOWS TO FALL BELOW FREEZING ACROSS PORTIONS OF THE FORECAST AREA. LATEST SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM NORTH CENTRAL MINNESOTA THROUGH WESTERN IOWA...MOVING EAST. CURRENT RADAR INDICATED SHOWERS AND THUNDERSTORMS WERE MOVING ACROSS NORTH CENTRAL INTO CENTRAL WISCONSIN...NORTH AND EAST OF THE INTERSTATE 94 CORRIDOR. THE COLD FRONT WILL PUSH ACROSS THE FORECAST AREA THIS MORNING INTO EARLY THIS AFTERNOON WITH THE MAIN IMPACT BEING A WIND SHIFT. IN ADDITION...WINDS WILL SWITCH TO THE NORTH AT 15 TO 20 MPH WITH GUST TO AROUND 30 MPH POSSIBLE IN THE OPEN AREAS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA...AS WELL AS THE RIDGE TOPS OF WESTERN WISCONSIN. HIGH PRESSURE IS EXPECTED TO GRADUALLY BUILD INTO THE REGION LATE THIS AFTERNOON INTO TONIGHT...WITH CLOUDS DECREASING FROM NORTH TO SOUTH. LOOK FOR COOLER AIR TO FILTER INTO THE REGION TONIGHT. 850 MB TEMPERATURES THIS AFTERNOON WILL RANGE FROM 14 C ACROSS FAR SOUTHWEST WISCONSIN TO AROUND 4 C OVER NORTH CENTRAL WISCONSIN. BY EARLY WEDNESDAY MORNING THE 850 MB TEMPERATURES WILL FALL TO AROUND 0 C ACROSS FAR NORTHERN WISCONSIN TO AROUND 4 C ACROSS NORTHEAST IOWA. PLAN ON LOWS FALLING INTO THE LOWER 30S OVER NORTH CENTRAL WISCONSIN TO AROUND 40 ACROSS NORTHEAST IOWA...UNDER MOSTLY CLEAR SKIES. LIGHT NORTH WINDS AND VERY DRY AIR ALOFT SHOULD INHIBIT FROST DEVELOPMENT TONIGHT...DESPITE TEMPERATURES FALLING TO AROUND FREEZING ACROSS NORTH CENTRAL INTO CENTRAL WISCONSIN. CANNOT RULE OUT LOW LYING AREAS DECOUPLING AND FALLING BELOW FREEZING TONIGHT...SO WILL HAVE TO KEEP A CLOSE EYE ON TEMPERATURE TRENDS THIS AFTERNOON INTO THE EVENING HOURS. HIGH PRESSURE WILL CONTINUE BUILDING OVER THE AREA ON WEDNESDAY LEADING TO DRY AND QUIET CONDITIONS. AN UPPER LEVEL LOW IS EXPECTED TO MOVE FROM THE CENTRAL PLAINS...EAST THROUGH THE MIDDLE MISSISSIPPI RIVER VALLEY. SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS SOUTHERN IOWA THROUGH MISSOURI AND REMAIN WELL SOUTH OF THE FORECAST AREA. RATHER DRY AIR WILL SETTLE OVER THE AREA ON WEDNESDAY. AFTERNOON MIXING WILL LEAD TO DEW POINTS FALLING INTO THE 20S TO THE UPPER TEENS...WITH VERY DRY AIR JUST ABOVE THE SURFACE. HAVE LOWERED DEW POINTS SIGNIFICANTLY FOR WEDNESDAY AFTERNOON. PLAN ON HIGHS ON WEDNESDAY RANGING FROM THE MID 50S ACROSS NORTHERN WISCONSIN TO AROUND 60 OVER NORTHEAST IOWA. LIGHT WINDS AND MOSTLY CLEAR SKIES WEDNESDAY NIGHT WILL AGAIN LEAD TO FROST/FREEZING CONCERNS. PLAN ON LOW TEMPERATURES FALLING INTO THE UPPER 20S ACROSS NORTH CENTRAL AND CENTRAL WISCONSIN. TEMPERATURES WILL FALL INTO THE LOWER 30S ALONG THE MISSISSIPPI RIVER WESTWARD THROUGH SOUTHEAST MINNESOTA INTO NORTHEAST IOWA. FREEZE HEADLINES MAY BE NEEDED IN CENTRAL AND NORTH CENTRAL WISCONSIN. FROST DEVELOPMENT IS IN QUESTION GIVEN THE VERY DRY AIR OVER THE AREA AND LIGHT NORTHEAST WINDS. AT THIS TIME FROST WIDESPREAD FROST FORMATION IS NOT ANTICIPATED BUT TEMPERATURES FALLING BELOW FREEZING COULD DAMAGE COLD SENSITIVE PLANTS. FAVORED COLD AIR DRAINAGE LOCATIONS ACROSS FAR WESTERN AND SOUTHWEST WISCONSIN COULD ALSO BE AT RISK OF SEEING THESE COLD TEMPERATURES. THE HIGH IS EXPECTED TO PERSIST THURSDAY INTO THURSDAY NIGHT...WITH THE CENTER OF THE HIGH BACKING INTO CENTRAL AND NORTHEAST WISCONSIN. 850 MB TEMPERATURES REALLY FALL ON THURSDAY...WITH FORECAST MODELS SHOWING TEMPERATURES RANGING FROM -4 C OVER NORTHEAST WISCONSIN TO AROUND 2 C OVER NORTHEAST IOWA. PLAN ON HIGH TEMPERATURES RANGING FROM THE LOWER 50S ACROSS NORTH CENTRAL WISCONSIN TO THE MID 50S OVER NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN UNDER SUNNY SKIES. HAVE LOWERED DEW POINTS AGAIN FOR THURSDAY AFTERNOON DURING THE MAXIMUM MIXING. CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO PLUMMET THURSDAY NIGHT. THERE WILL ONCE AGAIN BE THE CONCERN FOR FREEZING TEMPERATURES ACROSS MUCH OF THE FORECAST AREA WITH LOWS RANGING FROM THE LOWER 30S ACROSS NORTH CENTRAL WISCONSIN TO THE MID 30S OVER PORTIONS OF NORTHEAST IOWA. FREEZE HEADLINES MAY BE NEEDED ONCE AGAIN THURSDAY NIGHT. .LONG TERM...FRIDAY THROUGH MONDAY 349 AM CDT TUE APR 3 2012 03.00 MODELS SHOWING THE HIGH STARTING TO MOVE EAST ON FRIDAY AS A TROUGH EJECTS EASTWARD OUT OF THE CENTRAL ROCKIES. THE TROUGH IS EXPECTED TO PUSH THROUGH THE DAKOTAS FRIDAY NIGHT AND INTO WESTERN MINNESOTA BY SATURDAY MORNING. FORECAST MODEL ARE SHOWING SOME DIFFERENCES BRINGING THE TROUGH ACROSS THE REGION ON SATURDAY. THERE APPEARS TO BE TWO PIECES OF ENERGY ASSOCIATED WITH THIS FEATURE. THE BULK OF THE PRECIPITATION SHOULD OCCUR ACROSS NORTHERN MINNESOTA...WHERE THE MAIN UPPER LEVEL WAVE IS EXPECTED TO TRACK. THE GFS SHOWS A SECONDARY SHORTWAVE MOVING THROUGH LATE SATURDAY AFTERNOON INTO SUNDAY. THE ECMWF DOESNT INDICATE THIS SECONDARY WAVE...KEEPING THE FORECAST AREA MAINLY DRY ON SATURDAY. HAVE LEANED TOWARD A MODEL CONSENSUS BLEND MAINTAINING A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE DAY ON SATURDAY. PLAN ON HIGH TEMPERATURES IN THE UPPER 50S TO LOWER 60S ON SATURDAY. RAIN CHANCES WILL SHIFT EAST OF THE AREA SATURDAY NIGHT WITH BREEZY WESTERLY WINDS SETTING UP ACROSS THE REGION ON SUNDAY. SLIGHTLY COOLER TEMPERATURES CAN BE EXPECTED ACROSS THE AREA WITH HIGHS IN THE 50S. ANOTHER TROUGH WILL DROP INTO THE UPPER MISSISSIPPI RIVER VALLEY ON MONDAY FROM SOUTHERN MANITOBA/ONTARIO BRINGING A SLIGHT CHANCE OF SHOWERS TO THE FORECAST AREA. LOOK FOR HIGHS ON MONDAY TO RANGE FROM THE UPPER 40S ACROSS NORTH CENTRAL WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA. && .AVIATION...TODAY AND TONIGHT 649 AM CDT TUE APR 3 2012 A COLD FRONT MOVING THROUGH ALOFT HAS HELPED SPARK A FEW SHOWERS AND STORMS NEAR THE KLSE TAF SITES. ANTICIPATING THESE TO MOVE SOUTHEAST WITH THE FRONT...SO ONLY AN HOUR OF POTENTIAL SHOWERS AND THUNDERSTORMS COULD IMPACT THE KLSE TAF SITE. GIVEN THE ISOLATED NATURE...ONLY PUT VCSH IN THE TAF. LIGHTNING IS EVEN MORE ISOLATED...SO ONLY THE CB IS IN THE TAF. OTHERWISE...MVFR TO VFR STRATUS HAS FILTERED INTO THE TAF SITES IN THE WAKE OF A SURFACE COLD FRONT THAT MOVED THROUGH OVERNIGHT. MVFR CEILINGS HAVE BEEN CONFINED TO KRST AND VFR AT KLSE. ANTICIPATING THIS STRATUS TO REMAIN IN PLACE THROUGH 20Z...WITH DAYTIME MIXING ALLOWING CEILINGS TO RISE. BETWEEN 20-22Z...DRIER AIR HELPING TO CLEAR SKIES IN NORTHWEST MINNESOTA WILL MOVE IN AND CLEAR SKIES AT THE TAF SITES. VFR CONDITIONS ARE THEN ANTICIPATED TO CONTINUE THROUGH TONIGHT. SHOULD SEE SOME GUSTY NORTHERLY WINDS TODAY...AHEAD OF HIGH PRESSURE BUILDING INTO NORTHWEST MINNESOTA. GUSTS OF 15 TO 25 KTS ARE POSSIBLE...HIGHEST AT KRST. LOSS OF HEATING THIS EVENING WILL ALLOW GUSTS TO DIMINISH. && .ARX WATCHES/WARNINGS/ADVISORIES... 349 AM CDT TUE APR 3 2012 WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...AJ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...AJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
536 PM CDT TUE APR 3 2012 .UPDATE... ISSUED AT 528 PM CDT TUE APR 3 2012 USED THE HRRR MODEL TRENDS FOR THIS FORECAST. A FEW SHOWERS HAVE DEVELOPED ALONG THE NORTHWEST EDGE OF OUR CWA AND THAT IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF HOURS. MAJORITY OF MODELS WANT TO DEVELOP AN MCS OVER CENTRAL MISSOURI...MOVE IT EAST THEN SOUTHEAST WHICH MEANS IT MIGHT CLIP THE SOUTHWEST INDIANA AREA. SO WENT WITH HIGH CHANCE AND LIKELY POPS OVER THE NORTHERN SECTIONS TONIGHT. BLENDED A BIT DURING THE MORNING HOURS SO THAT IT IS A SMOOTHER TRANSITION ACROSS THE SOUTHERN SECTIONS. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 325 PM CDT TUE APR 3 2012 A WEAK SHORT WAVE ALOFT WILL BEGIN TO INTERACT WITH A SURFACE FRONT LIFTING NORTH OF THE REGION TONIGHT. ACTUALLY WAITING FOR CONVECTION TO START FIRING OVER THE THE WESTERN HALF OF THE REGION ANYTIME LATE THIS AFTERNOON. SURFACE HEATING AHEAD OF THIS SYSTEM...ESP EAST OF THE MS RIVER WILL HELP GENERATE SURFACE BASED LI VALUES IN THE -4 TO -8 RANGE. IF DEBRIS CLOUDS DO NOT INHIBIT THIS INSTABILITY FROM FORMING...SOME OF THE THUNDERSTORMS THAT DEVELOP COULD BE QUITE STRONG TO SEVERE IN THE LATE AFTERNOON INTO EARLY EVENING. DUE TO RELATIVELY LIGHT FLOW ALOFT...IF ANY ISOLATED STRONG CONVECTION DOES MANAGE TO DEVELOP...IT WILL LIKELY BE PULSE-TYPE CLUSTERS IN NATURE...WITH RAPID GROWTH AND DECAY OF EMBEDDED CELLS. ONCE THE SFC FRONT AND H50 TROF MOVE NORTH OF THE FORECAST AREA LATER TONIGHT...WE WILL BE UNDER THE INFLUENCE OF RICH MOIST SW FLOW AT ALL LEVELS. THOUGH NO REAL TRIGGER IS INDICATED AT THIS TIME...THIS TYPE OF PATTERN COULD PRODUCE SCATTERED SHOWERS AND STORMS AT ABOUT ANY TIME. THEREFORE...WILL LEAVE AT LEAST SCT MENTIONING IN THE FORECAST ALL OF TONIGHT FOR OFF AND ON SHOWERS/STORMS. GOOD NEWS IS THAT WE WILL LOSE MUCH OF THE DAYTIME HEATING/INSTABILITY AND MID LEVEL FORCING...SO SEVERE ASPECT WILL BE LITTLE TO NULL. LITTLE CHANGE WITH THE MODELS/ENSEMBLES FOR WED. CONTINUE TO SHOW AN INITIALLY SLOW MOVING CLOSED H5 LOW MOVING ACROSS THE CENTRAL PLAINS AND INTO W TN BY 06Z FRI AS SURFACE LOW ALSO MOVES SE ACROSS MAINLY THE SW PART OF THE PAH FORECAST AREA. ACCORDINGLY THE BEST CHANCE OF SHOWERS/TSTMS WILL GENERALLY BE WEDNESDAY AFTERNOON INTO WED NIGHT EXCEPT IN THE OZARK FOOTHILLS OF SE MO WHERE THE BEST CHANCES MAY ARRIVE AS EARLY AS WEDNESDAY MORNING. A SURFACE HIGH PUSHING S INTO THE GREAT LAKES REGION WILL BRING DRIER AIR THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE APR 3 2012 THE LATEST MODELS AGREE THAT FRIDAY WILL BE A VERY DRY DAY WITH SOME WIND APPROACHING CRITICAL FIRE WEATHER THRESHOLDS. ALSO WITH WINDS MAINLY OUT OF THE NORTHEAST WOULD NOT EXPECT MUCH OF A REBOUND ON RH DURING THE DAY LIKE THE MODELS ARE SUGGESTING. SO WOULD EXPECT AT LEAST AN INCREASED FIRE DANGER ALTHOUGH FUELS MAY BE WET FROM PRECEDING RAINS. WILL PULL DEW POINTS DOWN FOR FRIDAY AT LEAST IN THE MIDDLE 30S FOR NOW AND MONITOR CLOSELY FOR EVEN DRIER WEATHER. FORECAST SOUNDING WOULD SUGGEST NEAR 30 AND THE NAM WOULD SUGGEST MID 20S DEW POINTS. WINDS SHOULD DECREASE SATURDAY AS SURFACE HIGH SETTLES OVER THE HEARTLAND. BOTH THE 12Z TUE GFS AND 00Z TUE ECMWF ARE IN UNUSUALLY FAIR AGREEMENT WITH A COLD FRONT TRAVERSING THE REGION SATURDAY NIGHT INTO SUNDAY MORNING. HOWEVER THE ECMWF IS MUCH DRIER WITH ONLY SPOTTY QPF...WHILE THE WETTER GFS HAS MORE SOLID COVERAGE AMOUNTS ARE MEAGER WITH LESS THAN A QUARTER INCH ANYWHERE. HOWEVER THEY BOTH AGREE THE PRECIP WILL BE POST FRONTAL SHOULD ANY OCCUR. SO WILL LEAVE IN SLGT CHC IN SUNDAY MORNING AND MIGHT HAVE TO TRIM POPS A BIT PRIOR TO SUNDAY MORNING TO BETTER REFLECT POST FRONTAL PRECIP. THERE WILL BE A REINFORCING FRONT MONDAY BRINGING YET ANOTHER SHOT AT SOME PRECIP. AFTER THAT HIGH PRESSURE RETURNS NEXT WEEK. AS FOR TEMPS WILL GO WITH ABOVE NORMAL TEMPS OR PERSISTENCE FCST UNTIL THE REINFORCING FRONT AND THEN WILL ACTUALLY HAVE A SHOT AT BELOW NORMAL TEMPS BY TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 325 PM CDT TUE APR 3 2012 AN UPPER LEVEL WAVE WILL LIFT NORTH/NORTHEAST ACROSS THE REGION THIS AFTERNOON. A BAND OF SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOULD ACCOMPANY THE UPPER LEVEL FEATURE AS THE SURFACE HEATS UP AND DESTABILIZES LATE TODAY. BEST CHANCE FOR SCT TSRA IS AT THE KPAH AND KCGI AIRPORTS THIS AFTERNOON...THEN SPREADING EAST NORTHEAST INTO THE NIGHT. OTHERWISE...VARIABLE CLOUDINESS...VFR CONDITIONS...AND SOUTH/SOUTHWEST WINDS MOSTLY BELOW 10 KTS. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...PS SHORT TERM...MEFFERT LONG TERM....KH AVIATION...MEFFERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
338 PM EDT TUE APR 3 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA TONIGHT, BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS. A LINGERING FRONTAL BOUNDARY BEHIND THE LOW WILL SLIDE SOUTH OF THE AREA AND END THE CHANCE OF SHOWERS BY WEDNESDAY AFTERNOON. HIGH PRESSURE WILL THEN BRING DRY AND SEASONABLE CONDITIONS INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A NEAR ZONAL FLOW ON THE NORTHERN PERIPHERY OF A WEAK RIDGE ACROSS THE OHIO VALLEY. AT THE SURFACE, A 1009MB LOW IS LOCATED ILLINOIS WITH A WARM FRONT EXTENDING EASTWARD ACROSS CENTRAL OHIO. A CONVECTIVE COMPLEX CONTINUES TO WEAKEN AS IT SLIDES SOUTHEAST ACROSS EASTERN OHIO. THIS EVENING...DRY AIR AT THE SURFACE, INDICATED BY TD DEPRESSIONS OF 25-30F SHOULD CONTINUE TO LIMIT THE EASTWARD PROGRESSION OF SHOWERS INTO THE AREA. THE WARM FRONT WILL CONTINUE TO PUSH INTO THE AREA FROM THE SOUTHWEST AS THE SURFACE LOW TREKS ACROSS THE OHIO VALLEY. THIS WILL ALLOW FOR TEMPS TO CONTINUE TO WARM INTO THE EVENING. TONIGHT...THE SURFACE LOW WILL MOVE INTO WESTERN PENNSYLVANIA AS THE WARM FRONT STRADDLES THE AREA. NAM/GFS INDICATE AN AREA OF WEAK ELEVATED INSTABILITY PUSHING ACROSS THE AREA AND ALLOWING FOR THE CHANCE OF THUNDERSTORMS PRIMARILY SOUTH OF THE PITTSBURGH METRO OVERNIGHT. BY DAWN, THE FRONTAL BOUNDARY WILL HAVE PUSHED SOUTHWARD TO THE MASON-DIXON LINE, WITH LINGERING SHOWERS ALONG AND SOUTH OF THE BOUNDARY. OVERNIGHT LOWS ARE A FEW DEGREES WARMER THAN LAMP GUIDANCE, RANGING FROM THE LOWER 40S NORTH OF THE BOUNDARY ALONG THE I-80 CORRIDOR TO THE MID 50S IN NORTH-CENTRAL WV. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... GFS/ECMWF EQUIV POT TEMP AND DEW POINT GRADIENTS INDICATE THE FRONTAL BOUNDARY SLIDING FROM THE MASON-DIXON LINE INTO CENTRAL WV BY 21Z FRIDAY. BEFORE THE BOUNDARY SHIFTS SOUTHWARD, NAM/GFS INDICATE ENOUGH INSTABILITY TO SUPPORT CHANCE OF THUNDER WEDNESDAY LATE MORNING INTO THE EARLY AFTERNOON ACROSS PORTIONS OF NORTH- CENTRAL WV. HIGH PRESSURE APPROACHING FROM THE NORTHWEST ALONG WITH DRIER AND STABLE AIR WILL ALLOW FOR A DRY FORECAST FOR THE REMAINDER OF THE DAY ACROSS THE AREA. HIGH TEMPS FOR WEDNESDAY ARE A FEW DEGREES ABOVE SEASONAL NORMALS. THERE IS OPERATIONAL MODEL AGREEMENT THAT A SURFACE HIGH WILL MOVE FROM CENTRAL CANADA INTO THE GREAT LAKES WEDNESDAY NIGHT INTO FRIDAY. THIS WILL ALLOW FOR CLEARING SKIES WEDNESDAY NIGHT AND ABUNDANT SUNSHINE THURSDAY AND FRIDAY. TEMPERATURES ARE FORECAST TO NEAR NORMAL SEASONAL VALUES EACH DAY. WITH THE HIGH FUNNELING IN COLDER, CANADIAN AIR, FREEZES WILL AGAIN BE POSSIBLE NORTHEAST OF PITTSBURGH ON THURSDAY AND FRIDAY MORNING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO AT LEAST SUNDAY AND PERHAPS MONDAY. THEN UPPER LEVEL RIDGE BUILDING ACROSS THE HIGH PLAINS OF CENTRAL CANADA AND THE U.S. THIS WILL CAUSE INCREASED NORTHWEST FLOW DOWNWIND INTO THE UPPER OHIO VALLEY, WITH A SHOWERY COLD FRONTAL PASSAGE EITHER MONDAY OR TUESDAY. REGARDING TEMPERATURES, EXPECT A LARGER THAN NORMAL DIURNAL RANGE SATURDAY DUE TO RELATIVELY CLEAR SKIES ENHANCING RADIATIVE EFFECTS. LOWS FRIDAY NIGHT CAN BE ABOUT 5 DEGREES COLDER THAN NORMAL, WHILE SATURDAY AFTERNOON HIGHS CAN BE UP TO 10 DEGREES WARMER THAN NORMAL. DUE TO COLD FRONTAL PASSAGE TIMING UNCERTAINTY, FORECASTED TEMPERATURES SUNDAY INTO MONDAY TO BE NEAR SEASONABLE. BY TUESDAY, THE POSTFRONTAL COOL DOWN WILL CAUSE TEMPERATURES TO BE AT LEAST 5 DEGREES COLDER THAN NORMAL. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... RECENT RADAR AND SURFACE DATA SHOW THE WARM FRONTAL COMPLEX OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUING TO MOVE SOUTHEAST ACROSS CENTRAL OHIO. HAVE MENTIONED SHOWERS FOR KZZV, KHLG AND KMGW, THROUGH 23Z. ITS POSSIBLE TAF SITES FARTHER NORTH MAY ALSO GET VERY LIGHT SHOWERS. DESPITE THIS DEVELOPMENT, SURFACE LAYER REMAINS FAIRLY DRY, SO HAVE MAINTAINED VFR FLIGHT CONDITIONS FOR THE ENTIRE UPPER OHIO VALLEY THROUGH EARLY TONIGHT. SEVERAL SREF MODEL OUTPUT MEMBERS SHOW A SECOND COMPLEX OF SHOWERS AND SCATTERED THUNDERSTORMS, WITH MVFR FLIGHT CONDITIONS, MOVING SOUTHEASTWARD ACROSS THE I-70 CORRIDOR AND AREAS SOUTH LATE TONIGHT INTO WEDNESDAY MORNING, 07Z-15Z, IN ASSOCIATION WITH THE PASSAGE OF A LOW PRESSURE CENTER AND COLD FRONT. POST FRONTAL DRYING WILL RESTORE VFR THURSDAY AFTERNOON. SURFACE WINDS WILL VARY THIS AFTERNOON, BUT BECOME NORTHWEST LATE TONIGHT AND MONDAY AT 5 TO 10 KTS. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... EXPECT VFR DUE TO HIGH PRESSURE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
226 PM EDT TUE APR 3 2012 .SYNOPSIS... A WARM FRONT WILL BRING THE CHANCE OF SHOWERS AND THUNDERSTORMS IN EASTERN OHIO THIS AFTERNOON. LOW PRESSURE MOVING ACROSS THE OHIO VALLEY TODAY WILL MOVE INTO THE AREA OVERNIGHT AND BRING SCATTERED SHOWERS AND THUNDERSTORMS. CANADIAN HIGH PRESSURE WILL FOLLOW WITH DRY, SEASONABLE CONDITIONS INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... THE 18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST RADAR TRENDS, INCREASING POPS IN EASTERN OHIO AND MOVING POPS INTO PORTIONS OF WV AND PA. IN ADDITION, TEMPS HAVE BEEN DECREASED IN RAIN-COOLED PORTIONS OF EASTERN OHIO. THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A NEAR ZONAL FLOW ON THE NORTHERN PERIPHERY OF A WEAK RIDGE ACROSS THE OHIO VALLEY. AT THE SURFACE, A 1009MB LOW IS LOCATED ILLINOIS WITH A WARM FRONT EXTENDING EASTWARD ACROSS CENTRAL OHIO. A CONVECTIVE COMPLEX CONTINUES TO WEAKEN AS IT SLIDES SOUTHEAST INTO EASTERN OHIO. THIS AFTERNOON...CONVECTION ACROSS EASTERN AND CENTRAL OHIO WILL WEAKEN AND DIMINISH AS IT ENCOUNTERS DRIER AIR AND SLIDES SOUTHEASTWARD INTO WESTERN PA AND NORTHERN WV. A FEW RUMBLES OF THUNDER ARE NOT OUT OF THE QUESTION WEST OF I-77 IN OHIO. OTHERWISE, DRY AIR AT THE SURFACE, INDICATED BY TD DEPRESSIONS OF 25-30F, SHOULD LIMIT THE EASTWARD PROGRESSION OF SHOWERS INTO THE AREA. THE WARM FRONT WILL PUSH INTO THE AREA FROM THE SOUTHWEST AS THE SURFACE LOW TREKS ACROSS THE OHIO VALLEY AND TEMPS WILL CONTINUE TO WARM INTO THE EVENING. FORECAST CONSISTS OF A HRRR/LAMP BLEND, WITH HIGHS RANGING FROM THE MID 70S ACROSS EASTERN OHIO AND NORTH- CENTRAL WV TO THE MID 60S ALONG THE I-80 CORRIDOR. TONIGHT...THE SURFACE LOW WILL MOVE INTO WESTERN PENNSYLVANIA AS THE WARM FRONT STRADDLES THE AREA. MODERATE INSTABILITY UPSTREAM IN OHIO WILL ALLOW FOR CONVECTION TO DEVELOP THERE AND THEN PUSH INTO THE AREA OVERNIGHT. NAM/GFS INDICATE AN AREA OF ELEVATED INSTABILITY PUSHING ACROSS EASTERN OHIO AND ALLOWING FOR THE CHANCE OF THUNDERSTORMS TO CONTINUE ACROSS THE AREA OVERNIGHT. VERTICAL SHEAR IS RELATIVELY WEAK, SO BELIEVE THE SEVERE THREAT WILL BE LIMITED. HOWEVER, CANNOT RULE OUT THE ISOLATED POSSIBILITY OF HAIL IN EASTERN OHIO. BY DAWN, THE FRONTAL BOUNDARY WILL HAVE PUSHED SOUTHWARD TO THE MASON-DIXON LINE, WITH LINGERING SHOWERS ALONG AND SOUTH OF THE BOUNDARY. OVERNIGHT LOWS ARE A FEW DEGREES WARM THAN LAMP GUIDANCE, RANGING FROM THE LOWER 40S NORTH OF THE BOUNDARY ALONG THE I-80 CORRIDOR TO THE MID 50S IN NORTH-CENTRAL WV. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... PASSAGE OF THE LOW PRESSURE LATE TNGT/EARLY WEDNESDAY WL AMPLIFY FLOW ALOFT/PUSH A COLD FRONT ACROSS THE AREA. SHOWER AND THUNDERSTORM CHANCES ARE THUS FORECAST TO INCREASE TONIGHT AS LOW PRESSURE CENTER IS PROJECTED TO MOVE EASTWARD ALONG THE SOUTHWARD SAGGING FRONTAL BOUNDARY. PRECIP PROBABILITIES IN THE CHANCE CATEGORY WL BE MAINTAINED FOR MOST ZONES GIVEN PROGS OF LIMITED MOISTURE RETURN...BUT LIKELY NUMBERS WL BE INCLUDED FOR COUNTIES ALONG AND SOUTH OF I 70 AS THE ADVANCING LOW IMPROVES THE MOISTURE PROFILE FOR THOSE ZONES. THE STORM PREDICTION CENTER HAS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF EAST CENTRAL OHIO FOR TONIGHT. HAVE OPTED TO MENTION NO MORE THAN A LOW PROBABILITY AT THIS TIME AS MOST SREF MODEL MEMBERS SHOW RATHER WEAK INSTABILITY AND VERTICAL SHEAR. AT ANY RATE...THAT LOW WL ALSO PULL THE COLD FRONT SUFFICIENTLY SOUTHWARD WITH ITS WEDNESDAY PASSAGE TO QUICKLY DRY THE WEATHER FOR THE REMAINDER OF THE SHORT TERM PERIOD. TROUGH ALOFT/COOL HIGH PRESSURE ON THE SURFACE WL RETURN TEMPERATURES BACK TO NORMAL...WITH FREEZES POSSIBLE ON THURSDAY AND FRIDAY MORNINGS ACROSS THE AREAS NORTH AND EAST OF PITTSBURGH. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO DAYTIME SUNDAY. CONSENSUS OF MODELS THEN SHOW THE UPPER LEVEL JET STREAM PATTERN BECOMING MORE ZONAL WITH A SOUTHWEST ORIENTATION. THIS ZONAL UPPER FLOW WILL STEER A COLD FRONTAL BAND OF SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY SUNDAY NIGHT INTO MONDAY. FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAEFS MODEL OUTPUT, TO BE NEAR NORMAL FRIDAY, FOLLOWED BY A PREFRONTAL WARM UP SATURDAY AND SUNDAY TO VALUES UP TO 10 DEGREES ABOVE NORMAL. TEMPERATURES MONDAY SHOULD BE CLOSER TO NORMAL DUE TO CLOUDS AND SHOWERS AND POTENTIAL POSTFRONTAL COOLING, ALTHOUGH THE LATTER WILL BE LIMITED BY THE SOUTHWEST WINDS ALOFT. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... RECENT RADAR AND SURFACE DATA SHOW THE WARM FRONTAL COMPLEX OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUING TO MOVE SOUTHEAST ACROSS CENTRAL OHIO. HAVE MENTIONED SHOWERS FOR KZZV, KHLG AND KMGW, THROUGH 23Z. ITS POSSIBLE TAF SITES FARTHER NORTH MAY ALSO GET VERY LIGHT SHOWERS. DESPITE THIS DEVELOPMENT, SURFACE LAYER REMAINS FAIRLY DRY, SO HAVE MAINTAINED VFR FLIGHT CONDITIONS FOR THE ENTIRE UPPER OHIO VALLEY THROUGH EARLY TONIGHT. SEVERAL SREF MODEL OUTPUT MEMBERS SHOW A SECOND COMPLEX OF SHOWERS AND SCATTERED THUNDERSTORMS, WITH MVFR FLIGHT CONDITIONS, MOVING SOUTHEASTWARD ACROSS THE I-70 CORRIDOR AND AREAS SOUTH LATE TONIGHT INTO WEDNESDAY MORNING, 07Z-15Z, IN ASSOCIATION WITH THE PASSAGE OF A LOW PRESSURE CENTER AND COLD FRONT. POST FRONTAL DRYING WILL RESTORE VFR THURSDAY AFTERNOON. SURFACE WINDS WILL VARY THIS AFTERNOON, BUT BECOME NORTHWEST LATE TONIGHT AND MONDAY AT 5 TO 10 KTS. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... EXPECT VFR DUE TO HIGH PRESSURE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT TUE APR 3 2012 .SYNOPSIS... ISSUED AT 533 AM EDT TUE APR 3 2012 RIDGE OVER THE AREA SINCE LATE IN THE WEEKEND IS BEING FLATTENED OUT THIS MORNING AS STRONG SHORTWAVE TROUGH SLIDES FM MANITOBA INTO NORTHWEST ONTARIO. HEIGHT FALLS ARE SUBTLE OVR UPR LAKES PER 00Z RAOBS BUT ENOUGH TO TRIGGER MULTIPLE CLUSTERS OF SHRA/TSRA OVR THE UPPER GREAT LAKES. FRONTAL BOUNDARY...EXTENDING SOUTH OUT OF LOW OVR NORTHERN ONTARIO AND ALSO EXTENDING TO THE NORTH FM LOW OVR MID MISSISSIPI RIVER VALLEY WILL CROSS UPR MICHIGAN THIS MORNING. COOLER AIRMASS ADVECTS OVR THE AREA LATER TODAY THROUGH TONIGHT AND WEDNESDAY. AFTER THE FROPA THIS MORNING...DRY WEATHER WILL PREVAIL THROUGH LATE THIS WEEK AS LARGE HIGH PRESSURE IS DOMINANT WEATHER FEATURE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 533 AM EDT TUE APR 3 2012 TODAY...CONVECTIVE TRENDS WILL BE CHALLENGING THIS MORNING...BUT AFTER THAT DRYING TREND WILL FIRMLY TAKE HOLD. AS OCCURRED 24 HR AGO...MAIN AREA OF CONVECTION OVERNIGHT HAS DEVELOPED CLOSER TO H7 MOIST AXIS AND ALSO IN AREA OF H85 TEMP ADVECTION. INITIAL SHRA/TSRA HEADING QUICKLY INTO THE FAR EAST CWA FORMED AHEAD OF ONTARIO SHORTWAVE TROUGH AND HAVE BEHAVED FOLLOWING STEADY EASTWARD MOTION. CONVECTION OVR MN AND WESTERN WI IS OUTLINED WELL BY WHERE RUC13 SHOWS MAXIMUM H7 MOISTURE TRANSPORT AND ON NORTHERN EDGE OF STEEPER H7-H5 LAPSE RATES AOA 8C/KM. AT THIS TIME...MAJORITY OF TSRA ARE OCCURRING OVR CNTRL WI BUT ADDITIONAL SHRA WITH EMBEDDED TSRA ARE FILLING IN INTO NORTHWEST WI. FOLLOWING RUC IDEA THERE IS ENOUGH H7 MOISTURE TRANSPORT INTO SCNTRL CWA TO KEEP HIGHER POPS THERE IN THE MORNING. A FEW SHRA/TSRA MAY EVEN CLIP AREAS FARTHER NORTH IN THE CNTRL CWA BUT IT IS FAIRLY LIMITED CHANCE AS THE AREA OF SHRA/TSRA OVR NORTHWEST WI WILL BE OUTRUNNING BETTER H7 MOISTURE CONVERGENCE AND ELEVATED INSTABILITY IF THEY CONTINUE ON ENE TRACK. OVERALL IMAGINE CHANCES OF CONVECTION WILL BEGIN TO WANE SIGNIFICANTLY OVR MOST AREAS AFTER MID MORNING /POST 15Z-16Z/ SINCE SFC FRONT WILL BE DROPPING S/SE OF THE AREA BY THAT TIME. HAVE HAD SOME PEA-SIZED HAIL OVERNIGHT WITH STRONGER STORMS AND THAT REMAINS POSSIBLE THIS MORNING GIVEN STEEP LAPSE RATES JUST UPSTREAM AND 30-35 KTS OF EFFECTIVE SHEAR FCST OVR CNTRL PORTIONS OF UPR MI. AS ALLUDED TO BEFORE...COLD FRONT WILL STEADILY SLIDE ACROSS THE AREA MID TO LATE MORNING. WINDS IN WAKE OF FRONT EXPECTED TO BECOME NORTH TO NORTHWEST. STILL APPEARS THAT THERE COULD BE BRIEF PERIOD OF LOWER CIGS AND MAYBE SOME FOG AS HIGHER DWPNTS JUST BEHIND FRONT SETTLE ACROSS LK SUPERIOR AND WINDS PROVIDE SOME UPSLOPE LIFTING OVR HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL CWA. POSSIBILITY FOR FOG MAY HAVE BEEN ENHANCED DUE TO THE DECENT COVERAGE OF SHRA/TSRA OVR LK SUPERIOR OVERNIGHT THAT MAY HAVE PROVIDED ADDITIONAL LOW-LEVEL MOISTENING. LOOKING UPSTREAM THERE IS AREA OF LOWER CLOUDS NORTHWEST OF LK SUPERIOR BUT THERE IS ALSO A MUCH LARGER AREA OF VERY DRY AIR/CLEAR SKIES PUSHING ACROSS MANITOBA AND NORTHWEST ONTARIO. REALLY HARD TO TELL AT THIS POINT HOW MUCH/IF ANY FOG IS PRESENT OVR WESTERN LK SUPERIOR...SO WILL NOT INCLUDE IN FCST FOR LATER THIS MORNING. EXPECT DRYING TO WIN OUT PRETTY EASILY AFTER MID AFTN ONCE BLYR DWPNTS FALL INTO THE LOWER 30S/MID-UPR 20S AS HIGH BEGINS TO NOSE INTO LK SUPERIOR REGION. SO SKY FCST SHAKES OUT AS FAIRLY CLOUDY IN THE MORNING BUT WITH FAIRLY SHARP CLEARING TREND BY MID AFTN FM WEST-TO-EAST. DESPITE THE SUNSHINE THIS AFTN...TEMPS SHOULD BE HELD DOWN MOST AREAS WITH GRADIENT WIND FLOWING OFF LK SUPERIOR. PROBABLY WILL SEE STEADY TEMPS ALONG LK SUPERIOR AND READINGS PUSHING INTO LOWER 50S FAR INLAND/LK MICHIGAN SHORE WITH LESS LAKE MODIFICATION GIVEN THE NORTHWEST WINDS. DWPNTS AND RH VALUES COULD CRASH OVR INTERIOR WEST BY LATE AFTN. CURRENT FCST HAS RH VALUES IN THE 30-40 PCT RANGE...BUT IF WINDS STAY MORE NW IT COULD GET WARMER WHICH WOULD RESULT IN RH VALUES BLO 30 PCT. VERY DRY AIRMASS BECOMES FIRMLY ENTRENCHED OVR AREA TONIGHT INTO WEDNESDAY AS HIGH PRESSURE BUILDS FM HUDSON BAY INTO THE WESTERN GREAT LAKES. NORTHERLY FLOW REMAINS OFF LK SUPERIOR BUT GIVEN PWATS FALLING TOWARD 50 PCT OF NORMAL...EXPECT INTERIOR CWA TO TRY TO DECOUPLE TONIGHT AND COOL OFF TOWARD THE LOWER DWPNTS ADVECTING INTO THE REGION. BENEATH MOSTLY SUNNY SKIES ON WEDNESDAY...MAIN CONCERN WILL BE ON FIRE WX WITH LOWER RH VALUES. HAVE DWPNTS IN AFTN MIXING OUT INTO THE UPR TEENS OVR INTERIOR SECTIONS...RESULTING IN RH VALUES BLO 30 PCT. WINDS WILL NOT BE VERY GUSTY /LEADING TO LESS IMPACT ON FIRE WX CUSTOMERS/ BUT A STEADY NORTH WIND UP TO 15 MPH IS EXPECTED. GIVEN THE FLOW...PROBABLY WILL HAVE TOUGH TIME REACHING 40 DEGREES ALONG LK SUPERIOR SHORE. MIXING HEIGHTS MUCH HIGHER TOWARD WI BORDER /H85-H8 PER FCST SOUNDINGS/ ALLOW TEMPS TO RISE WELL INTO THE 50S. OVERALL LOOKS LIKE PRETTY TYPICAL SPRING PATTERN. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 533 AM EDT TUE APR 3 2012 HIGH PRESSURE WILL DOMINATE MUCH OF THIS PERIOD. WHILE THE SFC RIDGE WILL BE OVERHEAD AT 00Z THURSDAY...THE MAIN HIGH WILL LIKELY RESIDE OVER HUDSON BAY AND NW ONTARIO. EXPECT THE CENTER OF HIGH PRESSURE TO SLOWLY SIDE OVER LAKE SUPERIOR THURSDAY INTO FRIDAY. DRY AIR WILL CONTINUE TO SLIDE INTO THE AREA FROM EASTERN ONTARIO...WITH HUMIDITY VALUES FALLING 25 TO 25 PERCENT THURSDAY AND FRIDAY AFTERNOON AWAY FROM THE LAKE SUPERIOR COASTLINE. ON THE PLUS SIDE...WINDS SHOULD BE FAIRLY LIGHT...LESS THAN 10KTS AWAY FROM ANY LAKE BREEZES THAT MAY COME IN THURSDAY AND FRIDAY AFTERNOON. STILL...IT WILL BE ENOUGH TO INCREASE FIRE WEATHER CONCERNS OVER UPPER MICHIGAN THROUGH THE REMAINDER OF THE WORK WEEK. THERE WILL BE A SUBTLE CHANGE FRIDAY...AS THE HIGH PRESSURE SYSTEM BEGINS TO SHIFT EASTWARD IN RESPONSE TO A SFC LOW ORGANIZING OVER EASTERN WY/MT INTO THE WESTERN DAKOTAS. LOOK FOR A SLOW RETURN TO S/SE WINDS FRIDAY INTO FRIDAY NIGHT. THE PRESSURE GRADIENT WILL TIGHTEN OVER THE WEEKEND. EXPECT INCREASED S/SE WINDS OF 10 TO 15KTS SATURDAY /AHEAD OF THE COLD FRONT CROSSING SATURDAY NIGHT/. SPECIFICS FOR THIS PERIOD ARE A LITTLE TRICKY...WITH THE BREAKDOWN OF THE 500MB RIDGE SATURDAY NIGHT AS THE MAIN LOW REMAINS WELL TO OUR NORTH. THE 03/00Z RUN OF THE ECMWF CONTINUES TO SHOW LIMITED MOISTURE...WITH LITTLE MORE THAN A TRACE OF RAIN FALLING SATURDAY NIGHT AS MUCH OF THE ENERGY REMAINS WRAPPED UP ACROSS CANADA MAINLY ON THE BACK SIDE OF THE LOW. THE 03/00Z RUN OF THE GFS ON THE OTHER HAND INDICATES THE POTENTIAL FOR AROUND A TENTH OF AN INCH OF WELL NEEDED RAIN...WITH STILL THE BEST CHANCE BEHIND THE LOW. GIVEN THE LOW POTENTIAL FOR EVEN RAIN...KEPT ONLY SLIGHT CHANCE TS IN THE FCST FOR SATURDAY AFTERNOON INTO SATURDAY NIGHT. WINDS WILL REMAIN STRONGER ON THE ORDER OF 15 TO 20KTS OUT OF THE W BEHIND THE COLD FRONT AS THE SFC LOW SHIFTS FROM NEAR LAKE WINNIPEG AT 12Z SATURDAY...TO NORTHERN ONTARIO/HUDSON BAY ON SUNDAY. NO SIGNIFICANT WARM UP IS IN SIGHT...WITH 850MB TEMPS HOVERING AROUND 0C SUNDAY WITH TEMPS FALLING TO AROUND -8C MONDAY AFTERNOON ON N-NW WINDS OFF LAKE SUPERIOR. DID NOT GO WITH FALLING SFC TEMPS FOR MONDAY QUITE YET...EVEN THOUGH BOTH THE GFS AND ECMWF LOOK FAIRLY CONSISTENT WITH THIS IDEA. AS NOTED IN THE PREVIOUS DISCUSSION...WRAP AROUND MOISTURE LOOKS TO BET BEHIND THE LOW...PARTICULARLY IN NW FLOW OFF LAKE SUPERIOR CAN LINGER OVER THE CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 149 PM EDT TUE APR 3 2012 LOW PRESSURE TROUGH HOVERING JUST EAST OF UPPER MICHIGAN WILL SLOWLY EXIT EASTWARD THROUGH THE TAF PERIOD. DRY AIR OBSERVED ON INTERNATIONAL FALLS SOUNDING IS STEADILY EATING AWAY AT THE MORE EXTENSIVE CLOUD DECK. CLOUD COVER IS LINGERING OVER THE WEST...AT KCMX AND KIWD ASSOCIATED WITH LINGERING MOISTURE AND SOME LOCALIZED CONVERGENCE. THROUGH THE AFTERNOON...CLOUD COVER SHOULD GRADUALLY BECOME MORE SCATTERED AS OPPOSED TO THE BKN TO OVC SKIES THE SITES HAVE SEEN ALL MORNING. WOULD NOT BE SURPRISED IF THE BKN DECK AT KIWD DISSIPATED A LITTLE EARLIER THAN INDICATED IN THE TAFS...AND WILL AMEND ACCORDINGLY. WEBCAMS NEAR BESSEMER SHOW THE CLOUD COVERAGE BECOMING SCT IN NATURE...BUT HOUGHTON CAMERAS STILL SHOW A MORE SOLID DECK. OVERNIGHT EXPECT SKIES TO BE CLEAR...REMAINING THROUGH MID AFTERNOON TOMORROW. DAYTIME CUMULUS IS POSSIBLE AT KCMX AND KSAW WITH HEATING AND ADDED MOISTURE FROM NORTHERLY TO NORTHEASTERLY WINDS OFF LAKE SUPERIOR. OVERALL...THE TREND WILL BE TOWARDS VFR FOR ALL THREE SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 533 AM EDT TUE APR 3 2012 WINDS SHOULD REMAIN LESS THAN 30KTS THROUGH THE PERIOD...GETTING NEAR THIS LEVEL W AND CENTRAL SUNDAY AFTERNOON OFF WSW WINDS. IN THE SHORTER TERM...A TROUGH OF LOW PRESSURE OVER CENTRAL AND EASTERN LAKE SUPERIOR WILL EXIT ACROSS LAKE HURON THIS EVENING. THIS WILL MAKE WAY FOR LARGE HIGH PRESSURE OVER CENTRAL CANADA AND THE NORTHERN PLAINS TO SHIFT DIRECTLY OVER THE UPPER GREAT LAKES WEDNESDAY AFTERNOON...WHERE IT WILL REMAIN THROUGH FRIDAY. A LOW DEVELOPING OVER MANITOBA AND NORTH DAKOTA SATURDAY MORNING WILL SLIDE OVER NORTHERN LAKE SUPERIOR AND ONTARIO SATURDAY NIGHT INTO SUNDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLA SHORT TERM...JLA LONG TERM...KF AVIATION...MCB MARINE...KF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
101 PM EDT TUE APR 3 2012 .SYNOPSIS... HIGH PRESSURE OVER CENTRAL CANADA...WILL EXTEND INTO THE REGION TONIGHT...BEFORE SLIDING INTO THE GREAT LAKES LATER THIS WEEK. THIS PATTERN WILL BRING FAIR WEATHER TO NORTHERN MICHIGAN FOR THE NEXT SEVERAL DAYS...WITH HIGH AND LOW TEMPERATURES NEAR TO SLIGHTLY ABOVE AVERAGE. THE NEXT CHANCE OF RAIN WILL HOLD OFF UNTIL SATURDAY NIGHT INTO SUNDAY...AS A COLD FRONT MOVES THROUGH THE GREAT LAKES. && .UPDATE... ISSUED AT 1242 PM EDT TUE APR 3 2012 THE CLOUDY DAY CONTINUES ACROSS NRN MICHIGAN...BUT THE CLEARING LINE IS SET TO ARRIVE LATE THIS AFTERNOON. BETWEEN 4-6PM...MOST ALL OF EASTERN UPPER WILL HAVE BEEN CLEARED OUT...AND THEN 6PM TO 9PM FOR NRN LOWER. THIS CLEARING IS MAKING STEADY PROGRESS FROM WNW-ESE. THERE HAS BEEN SOME DIURNAL STRATO CU BEHIND IT...BUT BY THE TIME IT GETS HERE...SLOW LOSS OF DIURNAL HEATING OUGHT TO LIMIT THAT HERE. TEMPERATURES NOT TO DO MUCH THROUGH THE DAY DUE TO CLOUDS AND SLIGHT COOL ADVECTION...STILL ON TRACK FOR A SLOW CLIMB INTO THE UPPER 40S AND LOWER HALF OF THE 50S. NO ADDITIONAL UPDATES NEEDED. UPDATE ISSUED AT 1036 AM EDT TUE APR 3 2012 SHARPENING SHORTWAVE WORKING INTO ONTARIO CONTINUES TO FLATTEN THE UPPER RIDGE OVERHEAD...AS LOW LEVEL TROUGHING TRACKS TOWARD EASTERN UPPER. THERE HAVE BEEN A FEW REPORTS OF SOME VERY LIGHT RAIN OR DRIZZLE ASSOCIATED WITH THE TROUGH. THIS TROUGH CONNECTS BACK TO A WEAKENING AREA OF LOW PRESSURE THAT WAS SHIFTING ACROSS ILLINOIS THIS MORNING. SFC-H8 WARM FRONT WELL SOUTH OF US ALONG WITH THE MAIN INSTABILITY AND THUNDER POTENTIAL. REMOVED THUNDER FROM THE FORECAST...HOWEVER...DECAYING AREA OF LIGHT SHOWERS CONTINUES TO TRACK ACROSS ARENAC/GLADWIN COUNTIES. THIS PRECIPITATION WILL BE GONE IN THE NEXT HOUR. WE WILL THEN BE AWAITING UPSTREAM TROUGHING TO BRING IN SMALL CHANCE/PATCHY AREAS OF LIGHT RAIN/DRIZZLE. CHANCES LIKELY SMALLER THAN THAT...AS CONVERGENCE ASSOCIATED WITH THE TROUGH WANES...AS SOUTHERLY WINDS AHEAD OF IT WILL ALREADY BE TURNING AROUND OUT OF THE NORTH WITH PASSAGE OF LOW PRESSURE IN ILLINOIS. RATHER CLOUDY THROUGH MUCH OF THE DAY. VERY DRY AIR RETURNS TO EASTERN UPPER IN THE MID AFTERNOON HOURS...AND THEN LATE AFTERNOON/EVENING IN NRN LOWER. TEMPERATURES LOOKED REASONABLE WITH THE ONLY CHANGE WAS TO INCREASE HIGHS IN EASTERN UPPER DUE TO A BIT MORE SUNSHINE EXPECTED. UPDATE ISSUED AT 811 AM EDT TUE APR 3 2012 INITIAL BATCH OF SHWRS EXITED INTO LAKE HURON BY 6 AM. THE ENHANCED STRATIFORM AREA OF -RA WAS OVER LAKE MI AND WILL MOVE INTO NW LOWER MI IN THE NEXT HOUR. SINCE MCS WAS OVER CENTRAL WI AT TIME OF 313 AM FCST ISSUANCE...UNCERTAINTY HAS DIMINISHED ON ITS ARRIVAL. SO POPS WERE INCREASED TO 100% AND HAVE TIMED THIS THRU NRN LOWER PENINSULA. IF IT HOLDS TOGETHER...THE BACK EDGE SHOULD BE OFFSHORE INTO LAKE HURON NO LATER THAN 2 PM. THUNDER: THE BEST ARC OF ELEVATED INSTABILITY IS S OF M-55. BUT THE M-55 CORRIDOR HAS THE "BEST" CHC FOR THUNDER. WE SEE THE NEW SHWRS GOING UP OVER MANISTEE/WEXFORD COUNTIES. THAT OFFERS BETTER POTENTIAL THAN THE STRATIFORM AREA. A TENTH OF LIQUID WAS MEASURED AT STURGEON WI...ON THE W COAST OF LAKE MI IN THE PAST HOUR. SO A FEW HUNDREDTHS WILL FALL. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 QUITE AN AMPLIFIED PATTERN ONGOING OVER THE WESTERN HEMISPHERE EARLY THIS MORNING...WITH LARGE SCALE TROUGHS ANCHORED ALONG BOTH COASTS OF NOAM WITH A REX BLOCK-LIKE FEATURE STUCK BETWEEN THESE...KEEPING THE WEATHER SOMEWHAT INTERESTING OVER WHAT WOULD OTHERWISE BE LARGE-SCALE RIDGING. THE FOCUS FOR THE NEAR TERM AND THROUGH TODAY IS SHOWER AND THUNDERSTORM POTENTIAL AS INVERTED TROUGH PULLS INTO THE REGION FROM THE WEST. OVERNIGHT...SHOWERS AND THUNDERSTORMS HAVE MADE THE MOST OF VERY MEAGER INSTABILITY...CONTINUOUSLY FIRING ALONG THE H85 MOISTURE BOUNDARY AS IT PUSHES EAST INTO THE REGION. THROUGH DAYBREAK...I EXPECT AREAS FROM M-32 NORTH TO SEE SOME SHRA ACTIVITY /WITH A FEW EMBEDDED RUMBLES/...WITH A FEW MORE SHOWERS DOWN NEAR MANISTEE. THINGS GET TRICKIER AS WE HEAD INTO THE DAY TODAY...WITH THE IMPACTS OF ANOTHER CONVECTIVE COMPLEX NOW OVER WESTERN WISCONSIN NOT SO CERTAIN. CORFIDI VECTORS SUGGEST THAT THIS COMPLEX WILL PUSH EAST AND THEN SOUTHEAST...OVER THE TOP OF THE H5 RIDGE AXIS...WHICH WOULD SUGGEST ARRIVAL NEAR MY SOUTHWEST ZONES TOWARDS 12Z. THE HRRR IS ON BOARD WITH THIS...AS IS OUR PREVIOUS GRIDDED FORECAST AND WILL CONTINUE EARLY MORNING LIKELY POPS BASICALLY SOUTH OF M-72 AND WEST OF INTERSTATE 75. GIVEN THE TIME OF DAY...EXPECT THIS COMPLEX TO DIE AS IT MOVES EAST...WITH LITTLE TO HANG YOUR HAT ON FOR FORCING FOR THE REMAINDER OF THE DAY AS AFOREMENTIONED INVERTED TROUGH INCREASES LOW LEVEL CONVERGENCE TO SOME EXTENT. STILL...WITH MOIST PLUME OVERHEAD...AND CVA FROM WAVE NOW MOVING INTO WESTERN ONTARIO...EXPECT SOME ADDITIONAL SHOWERS TO POP UP ALONG THE H85 COLD FRONT AS IT SAGS THROUGH THE REGION THIS AFTERNOON. CONFIDENCE IS PRETTY LOW IN HOW THIS EVOLVES THIS AFTERNOON...AND THAT IS WHY I/LL KEEP POPS IN THE CHANCE CATEGORY. TEMPERATURES LIKELY WON/T MAKE TOO MUCH PROGRESS GIVEN CLOUD COVER. REALLY LIKED INHERITED HIGHS IN THE LOWER 50S /WITH A FEW MID 50S OVER SOUTHERN AREAS/ AND WILL CONTINUE THEM IN THIS PACKAGE. THIS IS TOWARDS THE COOLER END OF THE GUIDANCE ENVELOPE. TONIGHT...DRIER AIR PUSHES INTO THE REGION AS INVERTED TROUGH SCOOTS TO THE SOUTHEAST OF THE AREA WITH DEEP LAYER NORTHWEST FLOW DEVELOPING. THIS SHOULD SCOUR OUT ANY REMNANT LOW LEVEL MOISTURE...BRINGING CLEARING SKIES. WITH WINDS LIKELY TO REMAIN COUPLED...I DON/T EXPECT LOWS TO FALL ALL THAT FAR...WITH FAIRLY HOMOGENEOUS VALUES NEAR OR A LITTLE ABOVE 30 EXPECTED. WEDNESDAY...EXPANSIVE AREA OF HIGH PRESSURE BUILDS SOUTH INTO THE HUDSON BAY REGION WITH DRY NORTHWESTERLY FLOW VEERING NORTHERLY DURING THE DAY UNDER CONTINUED COLD ADVECTION. GIVEN VERY DRY ARRIVING AIRMASS...EXPECT A SUNNY/MSUNNY DAY WITH AMPLE SUBSIDENCE TO ENSURE LITTLE IN THE WAY OF CUMULUS DEVELOPMENT. WITH THE AFOREMENTIONED SUBSIDENCE...WOULDN/T BE SURPRISED IF WE DON/T MIX QUITE AS HIGH AS THE MODELS ARE ADVERTISING...AND UNDER COLD ADVECTION FEEL TEMPS WILL STRUGGLE A LITTLE. THEREFORE...WILL FOLLOW CLOSER TO THE COOLER SIDE OF THE GUIDANCE ENVELOPE /MET/ WITH HIGHS IN THE MID 40S OVER EASTERN UPPER...TO THE LOWER 50S OVER NORTHERN LOWER. GIVEN THE FLOW TRAJECTORIES AND SUBSIDENT FLOW...EXPECT A VERY DRY AIRMASS WITH DEWPOINTS LIKELY TUMBLING INTO THE UPPER TEENS BY MID/LATE AFTERNOON. THIS WILL BRING MINIMUM RH/S INTO THE 20S. WITH GUSTY NORTH/NORTHWEST WINDS...WILL CONTINUE ELEVATED FIRE DANGER WORDING IN THE MORNING HWO...BUT TEMPERATURES WILL BE WELL BELOW RED FLAG LEVELS. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 313 AM EDT TUE APR 3 2012 UPPER PATTERN REMAINS ONLY VERY SLOWLY PROGRESSIVE THRU THE REST OF THE WORK WEEK AND INTO THE WEEKEND. THAT WILL STILL EVENTUALLY BRING THE PAC NW UPPER TROF EASTWARD INTO OUR REGION...BUT LIKELY NOT UNTIL THE END OF THE WEEKEND. BEFORE THEN...THURSDAY/FRIDAY/SATURDAY CONTINUE TO LOOK RELATIVELY UNEVENTFUL...WITH SURFACE HIGH PRESSURE ENTRENCHED IN THE GREAT LAKES REGION. WED NIGHT-SAT...A REASONABLY VIGOROUS SHORTWAVE DROPS SOUTH ACROSS THE NORTHERN LAKES WED NIGHT. THIS SYSTEM IS MOISTURE-STARVED...AND WILL BRING NO MORE THAN SOME MID-HIGH CLOUDS...PRIMARILY TO EASTERN UPPER AND NE LOWER MI. HOWEVER...IT WILL PUSH A SECONDARY COLD FRONT ACROSS THE AREA...HELPING TO MAINTAIN 850MB TEMPS IN THE -6 TO -8C RANGE BY THU MORNING. WARM ADVECTION (ON N TO NE LOW LEVEL FLOW) AND AIRMASS MODIFICATION BEGIN SHORTLY THEREAFTER. BUT WE WILL STILL SEE SOMEWHAT COOLISH TEMPS...ESPECIALLY WED NIGHT AND THU NIGHT. EXPECT MINS MAINLY IN THE 20S...AND COULD DEFINITELY SEE TEENS IN THE USUAL COLD INTERIOR LOCALES. GIVEN OUR EARLY START TO THE GROWING SEASON...FROST/FREEZE HEADLINES COULD WELL BE NEEDED ON BOTH NIGHTS. WE/LL SEE ENOUGH SUN TO KEEP MAX TEMPS RESPECTABLE THURSDAY...MID 40S TO AROUND 50. RH LEVELS WILL BE PRETTY LOW DESPITE THE COOLISH TEMPS...WITH DEW POINTS IN THE TEENS (PERHAPS LOWER) AT PEAK HEATING. FOR NOW...IT LOOKS LIKE WE WON/T QUITE HAVE ENOUGH OF A NORTHERLY BREEZE TO MAKE FOR AN ENHANCED FIRE THREAT DAY. HIGH PRESSURE MOVES OVERHEAD BY FRIDAY...AND THE AIRMASS WILL CONTINUE TO MODERATE. MAX TEMPS WILL JUMP INTO THE 50S FRIDAY...AND WILL APPROACH 60F IN SPOTS SATURDAY...WITH PLENTY OF SUNSHINE. AFTER A DAY WITH HARDLY ANY WIND FRIDAY...A DEVELOPING SOUTHERLY BREEZE SATURDAY COULD ALSO PRODUCE AN ENHANCED FIRE THREAT...THOUGH FOR NOW (LIKE THURSDAY) FORECAST WINDS AREN/T QUITE STRONG ENOUGH. LATER PERIODS...TIMING AGREEMENT REMAINS DECENT ON LOW PRESSURE LIFTING TOWARD HUDSON BAY SAT NIGHT/SUNDAY...AND AN ASSOCIATED COLD FRONT CROSSING MI LATE SAT NIGHT/SUNDAY MORNING. CHANCE POPS STILL IN ORDER WAY OUT THEN. DEPENDING ON YOUR MODEL SOLUTION OF CHOICE... MAY HAVE ENOUGH COOL AIR AND DEEP CYCLONIC FLOW TO PRODUCE A CHANCE FOR RAIN/SNOW SHOWERS ON MONDAY. THE OPERATIONAL GFS IS AMONGST THE CHILLIEST/MOST MOIST BY MONDAY...IT HAS BEEN KNOWN TO OVERDUE THESE SORTS OF THINGS FROM TIME TO TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1242 PM EDT TUE APR 3 2012 VFR OVC CIGS THROUGH ALMOST ALL OF THE AFTERNOON. TROUGHING CONTINUES TO DROP INTO NRN MICHIGAN WITH WIDESPREAD CLOUDS. THE CLEARING LINE IS WORKING IT`S WAY TOWARD EASTERN UPPER MICHIGAN...SET TO MAKE AN ARRIVAL AT PLN AROUND 23Z...WITH THE OTHER AIRPORTS 1-2 HOURS AFTER. STRONG LOW LEVEL DRYING WILL LEAD TO CLEAR SKIES FOR THE NIGHT. NOT COLD ENOUGH FOR ANY SHALLOW CLOUDS OFF THE LAKE...PLUS WAY TOO DRY. MAYBE A TOUCH OF SHALLOW CU TOMORROW...BUT DOUBT IT. VFR THROUGH THE TAF PERIOD. VERY VERY MARGINAL LLWS FOR TONIGHT...AS THERE SHOULD AT LEAST BE A 3-5KT WIND WITH 20-25KTS ALOFT. && .MARINE... ISSUED AT 1242 PM EDT TUE APR 3 2012 NW WINDS DEVELOPING BEHIND LOW LEVEL TROUGHING WORKING THROUGH NRN MICHIGAN...WILL INCREASE TO 20-30KTS...STRONGEST ACROSS WHITEFISH BAY AND PRESQUE ISLE. NEAR NEUTRAL/SLIGHTLY UNSTABLE AIR JUST OFF THE WATER SURFACE WILL LEAD TO SMALL CRAFT ADVISORY GUSTS FOR THE ISSUANCE OF THOSE ADVISORIES AT WHITEFISH AND PRESQUE ISLE THROUGH TOMORROW. MAYBE A COUPLE MORE NEEDED. WINDS DO VEER AROUND TO OUT OF THE NORTHEAST WEDNESDAY NIGHT...AND ONLY LIGHTEN UP A SLIGHT BIT...BUT ADVISORIES NOT EXPECTED. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM EDT WEDNESDAY FOR LHZ347-348. LM...NONE. LS...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM EDT WEDNESDAY FOR LSZ321. && $$ UPDATE...SD SYNOPSIS...NS SHORT TERM...JA LONG TERM....JZ AVIATION...SD MARINE...SD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1229 PM CDT TUE APR 3 2012 .AVIATION...18Z TAF. PRIMARY FORECAST CONCERN FOR THIS TAF PERIOD LIES WITH WINDS/CLOUDS THIS AFTERNOON...THEN PRECIPITATION CHANCES LATER TONIGHT AND INTO TOMORROW. MAIN DRIVER REMAINS THE UPPER LEVEL LOW PRESSURE SYSTEM SPINNING OVER THE ERN CO/NM BORDER...WITH CLOUDS CONTINUING TO STREAM NORTH INTO THE REGION. EXPECTING MVFR CONDITIONS TO REMAIN THROUGH THE TAF PERIOD...WITH LOWER VISIBILITIES COMING TOWARD THE END OF THE PERIOD WHEN PRECIPITATION CHANCES INCREASE. KEPT THE 09Z START TIME FOR SHOWERS...THOUGH IT MAY VARY A BIT...JUST DEPENDS ON THE MODEL. OBVIOUSLY WILL GET A BETTER FEEL FOR TRENDS ONCE PRECIPITATION STARTS MOVING INTO THE AREA. WITH THE MAIN SURFACE LOW REMAINING OFF TO THE S/SW...WINDS ARE EXPECTED TO REMAIN N/NERLY THROUGH THE TAF PERIOD. SPEEDS WILL REMAIN GUSTY THIS AFTERNOON BEFORE DIMINISHING THIS EVENING/OVERNIGHT...BUT GUSTY CONDITIONS LOOK TO RETURN TOWARD THE END OF THE PERIOD. && PREV DISCUSSION... /ISSUED 355 AM CDT TUE APR 3 2012/ SHORT TERM...THROUGH THURSDAY NIGHT. PRIMARY CHALLENGE OVER THE NEXT 72 HOURS IS CLEARLY RAINFALL TRENDS/AMOUNTS...AS THE MID LEVEL LOW CURRENTLY CENTERED OVER EASTERN NEW MEXICO GRADUALLY LUMBERS EASTWARD NEAR THE OK/KS BORDER...AND EVENTUALLY INTO THE MID-SOUTH BY THURSDAY. CERTAINLY PARTS OF THE CWA ARE GOING TO SEE SOME WELL-TIMED BENEFICIAL RAINS IN EXCESS OF 0.75-INCH. ALSO NOT GOING TO SEE MUCH SUNSHINE FOR THE NEXT FEW DAYS. STARTING OFF EARLY THIS MORNING...08Z OBJECTIVE SURFACE ANALYSIS SHOWS THE CWA LOCATED WELL NORTH OF THE PRIMARY SURFACE COLD FRONT STRETCHED NORTHEAST ACROSS SOUTHEAST KANSAS FROM A FAIRLY WEAK LOW OVER THE TX PANHANDLE. WELL OFF TO THE NORTHWEST...A BROAD...ROUGHLY 1025 MB HIGH PRESSURE SYSTEM IS CENTERED ACROSS THE NORTHERN ROCKIES INTO ND. WITH THE CWA POSITIONED WITHIN THE HEART OF THE MAIN NORTH-SOUTH SURFACE PRESSURE GRADIENT...STEADY NORTH WINDS HAVE PREVAILED ALL NIGHT...WITH SUSTAINED SPEEDS COMMONLY 20-30 MPH WITH HIGHER GUSTS...BUT GENERALLY FALLING SHORT OF WIND ADVISORY CRITERIA IN MOST PLACES. RADAR...11-3.9 MICRON SATELLITE IMAGERY AND AUTOMATED OBS DEPICT A CORRIDOR OF WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS CENTERED OVER CENTRAL/NORTHWEST KANSAS...WITH SOME OF THIS ACTIVITY STARTING TO INCREASINGLY AFFECT AREAS MAINLY SOUTHWEST OF A BEAVER CITY-BELOIT LINE. AS FOR RAINFALL AMOUNTS IN THE PAST 12 HOURS...RADAR ESTIMATES THAT POCKETS OF THE SOUTHERN CWA...MAINLY THE KS COUNTIES...HAVE LIKELY TALLIED BETWEEN 0.25-0.50 INCH...ALTHOUGH MOST AREAS PROBABLY LESS. OTHERWISE...AN EXPANSIVE AREA OF LOW STRATUS MAINLY IN THE 800-1800 FT RANGE HAS OVERTAKEN THE ENTIRE CWA...WITH JUST A HINT OF LIGHT DRIZZLE IN THE AIR HERE AT THE WFO. UP TOP...WATER VAPOR SATELLITE CLEARLY DEPICTS THE AFOREMENTIONED CLOSED LOW CENTERED NEAR THE NM/TX BORDER...WHILE A RATHER PRONOUNCED RIDGE DOMINATES MUCH OF THE EASTERN CONUS. GETTING TO THE FORECAST AND STARTING WITH TODAY...IMMEDIATE SHORT TERM ISSUE OVER THE NEXT 4-6 HOURS IS PROGRESSION OF NEXT BATCH OF GENERALLY WEAK CONVECTION RIDING UP INTO SOUTHERN ZONES. WILL BE ISSUING A PRE-FIRST PERIOD ZONE FORECAST PACKAGE...WITH LIKELY POPS THROUGH 12Z FOR LOCATIONS MAINLY SOUTH OF A BEAVER CITY- BELOIT LINE. WITH RUC ADVERTISING AT LEAST 500 J/KG MUCAPE IN THESE AREAS...OCCASIONAL SMALL HAIL AND BRIEF BUT FREQUENT LIGHTNING STRIKES CERTAINLY ARE POSSIBLE EARLY THIS MORNING. OTHERWISE...FOLLOWING LATEST HRRR REFLECTIVITY PROGS...ALONG WITH 00Z 4KM WRF-NMM....MUCH OF THIS ACTIVITY SHOULD DECREASE IN COVERAGE...AND FAIL TO PUSH VERY FAR INTO THE NEB CWA OVER THE NEXT FEW HOURS AS THE SMALL SCALE SHORTWAVE CURRENTLY OVER NORTHWEST KS ROTATES BACK MORE TO THE WEST-NORTHWEST. MOVING ON TO THE DAYTIME 12Z-00Z TIME FRAME...ASSUMING THAT THE CURRENT CONVECTION DISSIPATES OR MOVES OUT BY AROUND SUNRISE...REALLY NOT EXPECTING A WHOLE LOT OF PRECIP POTENTIAL FOR THE MAJORITY OF THE CWA...AS THE LOCAL AREA REMAINS IN A BIT OF A LULL IN BETWEEN PUSHES OF MID/UPPER FORCING...WAITING FOR THE NEXT PRIMARY CHUNK OF ENERGY TO ROTATE NORTHWARD OUT OF THE SOUTHERN PLAINS AHEAD OF THE UPPER LOW. AS A RESULT...ACTUALLY HAVE NO PRECIPITATION MENTIONED WHATSOEVER ACROSS ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH THE DAY...AND ONLY 20-50 PERCENT POPS ACROSS SOUTHWEST ZONES...WITH EVEN THIS POTENTIALLY BEING TOO MUCH. EVEN IN AREAS WITH NO EXPECTATION OF MEASURABLE PRECIP...SUPPOSE SOME PATCHY DRIZZLE COULD CONTINUE PAST SUNRISE...BUT WILL LEAVE IT OUT FOR NOW AND TAKE ANOTHER LOOK ON UPDATE IN A FEW HOURS. IF ANY CONVECTION DOES SURVIVE/MOVE IN DURING THE DAY...ISOLATED THUNDER POTENTIAL IS CERTAINLY THERE WITH CONTINUED MUCAPE AVERAGING GENERALLY BELOW 500 J/KG...BUT POSSIBLY COULD BE ENOUGH TO GENERATE SOME SMALL HAIL. AS FOR HIGH TEMPS TODAY...FEEL THAT AT LEAST SLIGHTLY UNDERCUTTING MET/MAV GUIDANCE CONSENSUS IS THE WAY TO GO...AS LOW CLOUDS AND STEADY NORTHERLY BREEZES OF 15-25 MPH WILL PERSIST THROUGH THE DAY. MAY STILL BE TOO WARM IN SPOTS...BUT FOR NOW WILL AIM FOR MID-UPPER 50S IN MOST WESTERN AREAS...AND MAYBE SOME LOW 60S IN THE EAST. IN STARK CONTRAST TO THE PAST SEVERAL WEEKS...THESE HIGHS WOULD BE VERY NEAR IF NOT SLIGHTLY BELOW NORMAL FOR A CHANGE. THIS EVENING/TONIGHT...THIS IS WHEN LEGITIMATE WIDESPREAD RAINFALL WILL RAMP UP...BUT MAINLY ACROSS THE SOUTHERN 1/2 OF THE CWA. IN SHORT...UPPER DIVERGENCE INCREASES TO THE NORTH OF THE PARENT MID LEVEL LOW...WHICH WILL BE CENTERED GENERALLY OVER THE OK PANHANDLE. IN RESPONSE...A CLASSIC...GENERALLY EAST-WEST BAND OF STEADY SHOWERS AND POSSIBLY SOME EMBEDDED WEAK THUNDERSTORMS WILL GRADUALLY LIFT NORTH ACROSS KS THIS EVENING...AND HAVE POPS PRIOR TO 06Z RANGING FROM ONLY 20 PERCENT NEAR KGRI...TO 90 PERCENT IN MOST OF NORTH CENTRAL KS WHERE THE MAIN PRECIP AXIS WILL SET UP. FOR THE LATE NIGHT PERIOD...THEN HAVE HIGH 70-90 POPS EXPANDING NORTHWARD OUT OF KS INTO MUCH OF SOUTH CENTRAL NEB...BUT MAINLY SOUTH OF I-80. GIVEN TRENDS OF LATEST 06Z NAM...ALONG WITH 4KM WRF-NMM...AM STARTING TO WONDER IF NORTHERN COUNTIES SUCH AS VALLEY/NANCE ETC. WILL SEE MUCH OF ANYTHING BEFORE SUNRISE WED MORNING...AND A TIGHTER POP GRADIENT BETWEEN THE HAVES AND HAVE NOTS MAY PROVE NECESSARY. AS FOR RAINFALL AMOUNTS...EXPECT AT LEAST THE SOUTHERN 1/2 TO 1/3 OF THE CWA TO MEASURE BETWEEN 0.25-0.75 INCH OVERNIGHT...WITH LOCALLY HIGHER AMOUNTS POSSIBLE...AND AGAIN...A FAIRLY SHARP CUTOFF LIKELY SOMEWHERE NEAR I-80. ALTHOUGH CERTAINLY NOT EXPECTING SEVERE WEATHER...WILL KEEP ISOLATED THUNDER MENTION OVERNIGHT MAINLY ACROSS THE SOUTHERN 1/3 OF THE CWA...BUT EVEN SMALL HAIL SHOULD BE HARD TO COME BY. WEDNESDAY...FAIRLY WIDESPREAD RAIN SHOWERS WILL CONTINUE AS THE PARENT MID LEVEL CIRCULATION TRAVERSES EASTWARD NEAR OR JUST SOUTH OF THE KS/OK BORDER. KEPT A BROAD AREA OF LIKELY POPS GOING CWA- WIDE THROUGH THE DAY...ALTHOUGH LATEST NAM/ECWMF CONTINUE TO SUGGEST THAT THE NORTHERN 1/4 OR SO OF THE CWA...GENERALLY NORTH OF HWY 92...COULD STRUGGLE TO SEE MUCH...AND POPS IN THESE AREAS INCLUDING ORD/GREELEY MAY NEED TONED DOWN IN LATER FORECASTS. WITH WIDESPREAD CLOUDS/ONGOING PRECIP...LOWERED HIGH TEMPS 2-4 DEGREES IN MOST AREAS FROM PREVIOUS FORECAST...WITH ONLY LOW-MID 50S MOST AREAS. WEDNESDAY NIGHT...SHOWERS SHOULD GRADUALLY END FROM NORTHWEST- SOUTHEAST AS THE PARENT LOW PROGRESSES TO NEAR THE OK/AR BORDER...AND IT MAY VERY WELL END UP THAT MOST OF THE CWA...ESPECIALLY THE NORTHWEST 1/2...COULD STAY HIGH AND DRY THROUGH THE NIGHT. FOR NOW THOUGH WILL CONTINUE 20-40 POPS CWA-WIDE. THURSDAY...WILL CONTINUE TO KEEP IT DRY...RUNNING WITH THE ASSUMPTION THAT THE DEPARTING SYSTEM SHOULD BE FAR ENOUGH AWAY...ALTHOUGH SUPPOSE A FEW LIGHT WRAP AROUND SHOWERS COULD FLIRT WITH PARTS OF THE KS CWA. WITH AT LEAST PARTIAL SUNSHINE EXPECTED TO RETURN...TEMPS ARE FORECAST TO REBOUND BACK INTO THE LOW-MID 60S FOR HIGHS...BUT AM STAYING JUST BELOW THE MET/MAV GUIDANCE BLEND FOR NOW. AS SURFACE HIGH PRESSURE SLIDES EAST EAST-SOUTHEAST WINDS WILL PICK UP A BIT AS THE DAY WEARS ON. THURSDAY NIGHT...WILL ALSO MAINTAIN A DRY FORECAST...ALTHOUGH BOTH THE NAM/GFS ARE DEPICTING CONSIDERABLE LOW LEVEL SATURATION AND POSSIBLE DRIZZLE POTENTIAL MAINLY ACROSS WESTERN NEB/KS...BUT FOR NOW MOST IF NOT ALL OF THIS POTENTIAL LOOKS TO REMAIN WEST OF THE CWA THROUGH THE NIGHT. ALTHOUGH NOT IN THE FORECAST GRIDS AT THIS TIME...SUPPOSE SOME FOG REDUCING VISIBILITY AT LEAST INTO THE 1-2 MILE RANGE IS POSSIBLE ACROSS PARTS OF THE AREA EACH OF THE NEXT 3 NIGHTS...BUT WITH PRECIP GENERALLY EXPECTED TO BE FAIRLY WIDESPREAD AT LEAST THE NEXT 2 NIGHTS...NOT LOOKING LIKE AN OBVIOUS SETUP FOR WIDESPREAD...IMPACTFUL FOG. IN CLOSING...THIS SYSTEM WILL UNDOUBTEDLY BE A BENEFICIAL RAINER IN MANY AREAS...HELPING MAKE UP FOR A MARCH PRECIP DEFICIT. HOWEVER...THERE WILL LIKELY BE A SHARP NORTH-SOUTH RANGE IN RAINFALL AMOUNTS OVER THE NEXT 24-48 HOURS...WITH CURRENT FORECAST GRIDS AIMING FOR TOTALS RANGING FROM AT LEAST 1 TO 1.5 INCHES FOR MOST AREAS NEAR/SOUTH OF I-80...BUT ONLY 0.25-0.50 INCH...AND MAYBE NOT EVEN THAT MUCH...FOR SOME NORTHERN COUNTIES. LONG TERM...FRIDAY THROUGH MONDAY. BEGINNING ON FRIDAY AN UPPER LOW IS FORECAST TO BE CENTERED IN THE PACIFIC NW WITH TROUGH AXIS EXTENDING THRU THE CENTRAL ROCKIES. IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS...SFC TROUGH DEEPENS ALONG THE HIGH PLAINS. AS SFC GRADIENT TIGHTENS SOUTHERLY WINDS WILL INCREASE WITH BREEZY CONDITIONS SETTING UP BY AFTN AND MOISTURE WILL WORK NORTHWARD WITH DPS RISING DURING THE AFTN. ALTHOUGH MAIN FORCING WILL ARRIVE FRIDAY NIGHT AS UPPER SYSTEM LIFTS ACROSS THE NORTHERN PLAINS AND ASSOCIATED COLD FRONT CROSS OUR REGION...MODELS DO INDICATE SOME THETA E ADVECTION FRIDAY AHEAD OF SYSTEM AND WILL MAINTAIN OUR CURRENT LOW POPS DURING THE DAY FRIDAY. AS FRONT CROSSES FRIDAY NIGHT THERE IS A NARROW AXIS OF INSTABILITY ALONG/AHEAD OF BOUNDARY...MUCAPES NEARING 1000 J/KG...AND COULD POTENTIALLY SEE A STRONG STORM OR TWO. EASTER WEEKEND IS SHAPING UP TO BE DRY AND SEASONAL OVERALL. A 1030MB SURFACE HIGH BUILDS SOUTH BEING THE FRONT AND SETTLES ACROSS THE CENTRAL PLAINS OVERNIGHT. SFC DPS ARE PROGGED TO DROP TO THE TEENS IN OUR NW WITH 20S IN THE SOUTHEAST IN THE DRY AIRMASS. LOOKING LIKE A MUCH COLDER NIGHT THAN WE HAVE HAD RECENTLY HOWEVER NOT NECESSARILY UNUSUAL FOR THIS TIME OF YEAR WITH NORMAL LOWS IN THE LOW/MID 30S. FORECAST LOWS ARE IN THE 30S IN GENERAL AND AGREE PREVIOUS SHIFTS THAT THIS PERIOD WILL NEED TO BE MONITORED FOR FROST/FREEZE POTENTIAL. SURFACE RIDGE AXIS SLIPS SOUTHEAST ON SUNDAY WITH RETURN FLOW SETTING UP DURING THE DAY. ANOTHER COLD FRONT CROSSES THE PLAINS SUNDAY NIGHT/MONDAY ASSOCIATED WITH UPPER LOW IN ONTARIO AND TROUGH EXTENDING ACROSS THE UPPER MIDWEST/OHIO VALLEY REGION. BRUNT OF COLD AIR REMAINS EAST OF THE MISSOURI RIVER...HOWEVER SOME COOLER AIR DOES BACK INTO OUR NORTHEAST COUNTIES. THIS BEING SAID...ALTHOUGH HIGHS MAY DROP A DEGREE OR TWO FROM SUNDAY...TEMPS OVERALL ARE STILL LOOKING SEASONAL OR SLIGHTLY ABOVE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION...ADO SHORT...PFANNKUCH LONG...FAY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
635 PM EDT TUE APR 3 2012 .SYNOPSIS... AN AREA OF LOW PRESSURE WILL PASS SOUTH OF NEW YORK STATE TONIGHT AND MAY BRING A FEW ISOLATED SHOWERS TO PARTS OF WESTERN NEW YORK. ARCTIC HIGH PRESSURE WILL BUILD SOUTH ACROSS THE REGION WEDNESDAY WITH COOLER TEMPERATURES AND FAIR WEATHER RETURNING FOR THE REST OF THE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... A WEAK SURFACE LOW ACROSS ILLINOIS WILL TRACK ACROSS KENTUCKY OVERNIGHT. AN ASSOCIATED WARM FRONT EXTENDS TO THE ENE OF THE LOW...TOWARD WESTERN NEW YORK. WITH VERY DRY AIR IN PLACE BENEATH 700 MB...EXPECT MOST LOCATIONS TO LARGELY REMAIN DRY OVERNIGHT. HOWEVER...RADAR DOES SHOW SOME SHOWERS ACROSS SOUTHERN ONTARIO FROM PORT HURON TO LONDON...WITH WHATEVER DOES HOLD TOGETHER WITH THIS LIKELY TO CLIP WESTERN PORTIONS OF THE SOUTHERN TIER THIS EVENING. THE HRRR IS LATE...BUT APPEARS TO CAPTURE THIS EVENTUALLY...WITH THE GFS/RGEM/NAM HINTING AT THIS IN THE RH FIELDS MORE SO THAN THE QPF. BASED ON THE TRAJECTORY OF THE SHOWERS...WILL MAINTAIN CHANCE POPS IN SOUTHERNMOST PORTIONS OF THE CWA...WHILE TRIMMING THINGS BACK TO THE NORTH. MOSTLY CLOUDY SKIES THE FIRST HALF OF THE NIGHT WILL KEEP AREA TEMPERATURES QUITE A BIT WARMER TONIGHT THAN TUESDAY MORNINGS SUB- FREEZING READINGS. UPPER 30S FOR WESTERN NY AND THE FINGER LAKES AND LOW TO MID 30S FOR THE NORTH COUNTRY. SKIES SHOULD CLEAR FROM NW-SE LATE TONIGHT. ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY BEHIND THE DEPARTING LOW. 850MB TEMPS WEDNESDAY WILL DROP TO AROUND -3C WHICH WILL SUPPORT HIGH TEMPS ONLY REACHING INTO THE LOW 50S ACROSS WESTERN NY DESPITE MAINLY CLEAR SKIES. MORE CLOUDS OVER THE NORTH COUNTRY AND 850MB TEMPS CLOSER TO -4C/-5C WILL KEEP HIGH TEMPS LIMITED TO THE UPPER 40S/LOW 50S. WINDS WEDNESDAY WILL BECOME BREEZY IN THE AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS WITH THE APPROACHING ARCTIC HIGH AND THE SURFACE LOW OVER THE MID-ATLANTIC COAST. NORTHWEST GUSTS MAY APPROACH 20 TO 25 MPH ACROSS THE NORTH COUNTRY AND SOUTHEAST OF THE LAKE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... IT WILL BE SEASONABLY CHILLY DURING THIS PERIOD AS OUR REGION WILL REMAIN IN THE COLD SIDE OF A WEAKLY ESTABLISHED REX BLOCK. THIS LONGWAVE PATTERN WILL FEATURE A CUT OFF LOW OVER THE PLAINS THAT WILL BE TOPPED BY A HIGH AMPLITUDE RIDGE THAT WILL EXTEND NORTHWARDS PAST HUDSON BAY. WHILE THE UNDERLYING CUT OFF IS FORECAST TO PROGRESS EASTWARD ACROSS THE SOUTHERN STATES DURING THIS TIME FRAME...THE RIDGE WILL BE MUCH SLOWER IN ITS PROGRESSION ACROSS THE GREAT LAKES REGION. DOWNSTREAM FROM THE AFOREMENTIONED RIDGE WILL BE A FAIRLY SHARP TROUGH THAT WILL BE CENTERED OVER QUEBEC AND NEW ENGLAND. THIS WILL HOLD OUR TEMPERATURES AT OR SLIGHTLY BELOW NORMAL FOR THIS PERIOD... WHILE AN EXPANSIVE SFC HIGH WILL KEEP THE VAST MAJORITY OF THE REGION PRECIPITATION FREE. ALL IN ALL...A PRETTY `VANILLA` PERIOD. A ROBUST SHORTWAVE WILL DROP INTO THE BASE OF THE EASTERN CANADIAN TROUGH WEDNESDAY NIGHT...AND AS THIS BUNDLE OF ENERGY CROSSES THE NORTH COUNTRY...THERE MAY BE ENOUGH LOW LEVEL MOISTURE AND LIFT PRESENT TO POSSIBLY GENERATE A COUPLE WIDELY SEPARATED RAIN OR WET SNOW SHOWERS. WILL USE LOW CHC POPS TO COVER THIS MINIMAL POSSIBILITY. THE REMAINDER OF THE FORECAST AREA WILL BE PCPN FREE...BUT WITH ANOTHER FROST OR FREEZE. H85 TEMPS OF -8C WILL HELP TO PUSH OVERNIGHT LOWS BACK DOWN INTO THE 20S AND LOWER 30S. A MASSIVE AREA OF HIGH PRESSURE WILL EASE SOUTHWARDS ACROSS THE UPPER GREAT LAKES ON THURSDAY. THIS WILL PROVIDE OUR FORECAST AREA WITH PARTLY/MSTLY SUNNY SKIES...ALTHOUGH WITH H85 TEMPS STILL COLDER THAN -4C AND SOME RESIDUAL LOW LEVEL MOISTURE IN PLACE...SITES AWAY FROM THE LAKES MAY EXPERIENCE A FEW HOURS OF BROKEN STRATO-CU CLOUD COVER. IT WILL BE A COOL DAY AS WELL WITH MAX TEMPS STRUGGLING TO REACH NORMAL EARLY APRIL VALUES. AS THE LARGE SFC HIGH SETTLES OVER THE ENTIRE GREAT LAKES REGION THURSDAY NIGHT...THE PRESSURE GRADIENT WILL WEAKEN SO THAT VERY GOOD RADIATIONAL COOLING WILL BECOME ESTABLISHED UNDER CLEAR SKIES. THIS WILL SET THE STAGE FOR YET ANOTHER WIDESPREAD FREEZE AWAY FROM THE LAKES. OVERNIGHT LOWS WILL RANGE FROM THE FREEZING MARK NEAR THE LAKE SHORES TO 20 TO 25 IN THE SRN TIER VALLEYS AND EAST OF LAKE ONTARIO. FOR FRIDAY AND FRIDAY NIGHT...A H5 RIDGE WILL SLOWLY PUSH ACROSS THE UPPER GREAT LAKES WHILE THE CORE OF THE SFC HIGH WILL DRIFT TO BE ABOUT LAKE ERIE. THIS WILL PROVIDE OUR FORECAST AREA WITH NEARLY CLOUD FREE SKIES AND SEASONABLE TEMPERATURES. THAT WILL INCLUDE ANOTHER FROSTY NIGHT FRIDAY NIGHT...ESPECIALLY FOR THE SITES WELL AWAY FROM THE LAKES. && .LONG TERM /SATURDAY THROUGH TUESDAY/... FAIR...SEASONABLY MILD WEATHER AT THE START OF THIS PERIOD WILL GIVE WAY TO CHILLY UNSETTLED CONDITIONS AS TROUGHINESS OVER THE HIGH PLAINS OF SASKATCHEWAN WILL DIG SOUTHEAST ACROSS THE GREAT LAKES REGION. THIS FEATURE WILL EVENTUALLY CARVE ITS WAY INTO A LONGWAVE TROUGH OVER THE EASTERN HALF OF NORTH AMERICA. AS A RESULT... TEMPERATURES WILL DEFINITELY TREND DOWNWARDS DURING THIS PERIOD WITH BELOW NORMAL MERCURY READINGS BECOMING ESTABLISHED BY TUESDAY. THESE VALUES WILL LIKELY PERSIST THROUGH AT LEAST MID WEEK. SATURDAY WILL BE THE NICEST DAY OF THIS PERIOD...BY FAR...AS STRONG HIGH PRESSURE WILL DRIFT ACROSS OUR FORECAST AREA. SUN FILLED SKIES WILL BOOST SFC TEMPS INTO THE UPPER 50S TO LOWER 60S FOR MOST AREAS WITH EVEN WARMER CONDITIONS EXPECTED IN THE GENESEE VALLEY. AS THE HIGH MOVES OFF THE EAST COAST SUNDAY NIGHT...A PACIFIC BASED COLD FRONT WILL PUSH ACROSS THE UPPER GREAT LAKES AND MID WEST. THIS FRONT WILL MOVE ACROSS OUR AREA ON SUNDAY...AND WHILE THE VAST MAJORITY OF THE DAY SHOULD BE RAIN FREE...THERE WILL PROBABLY BE A 3 HOUR WINDOW OF SCT SHOWER ACTIVITY. SHORTWAVE RIDGING IN THE WAKE OF THE FRONT SHOULD PROVIDE US WITH DRY WEATHER SUNDAY NIGHT...BUT ADDITIONAL ENERGY FEEDING INTO THE TROUGH WILL ENCOURAGE THE SYSTEM TO DIG ITS WAY ACROSS LOWER ONTARIO. FALLING HGTS AND COLD ADVECTION FROM THIS PROCESS COULD SUPPORT SOME MORE SHOWERS...MAINLY IN THE AFTERNOON AND MONDAY NIGHT. ON TUESDAY...A DEEP LONGWAVE TROUGH WILL BE ANCHORED IN THE VCNTY OF NEW YORK STATE. THIS WILL KEEP COOL UNSETTLED WEATHER OVER OUR REGION WITH HIGH TEMPERATURES NOT MAKING IT OUT OF THE 40S. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS CONTINUE ACROSS THE ENTIRE AREA TODAY UNDER SCT CLOUD COVER. A WEAK SURFACE LOW WILL SHIFT SOUTH OF NEW YORK STATE TONIGHT WITH SKIES BECOMING OVERCAST BUT REMAINING VFR. A SLIGHT CHANCE OF ISOLATED RAIN SHOWERS IS POSSIBLE AS THE LOW SHIFTS EAST BUT CONFIDENCE IS TOO LOW TO INCLUDE IN TAFS OTHER THAN KJHW. ARCTIC HIGH PRESSURE WILL BUILD SOUTH WEDNESDAY AND SKIES WILL CLEAR EARLY WEDNESDAY WITH SOME SCATTERED DIURNAL CLOUDS RETURNING IN THE AFTERNOON. WINDS WILL INCREASE IN THE AFTERNOON WITH SOME GUSTS POSSIBLE TO 20 OR 25 KTS. OUTLOOK... WEDNESDAY NIGHT...MAINLY VFR. THURSDAY AND FRIDAY...VFR. SATURDAY...VFR. && .MARINE... A WEAK LOW WILL PASS JUST SOUTH OF NEW YORK STATE TONIGHT THEN SETTLE OFF THE EAST COAST BY WEDNESDAY MORNING WITH NO IMPACT TO WIND AND WAVE CONDITIONS ACROSS THE LAKES. A MODEST NORTH TO NORTHWEST FLOW OF COLDER AIR WILL SET UP ACROSS THE LAKES WEDNESDAY AND THURSDAY AS ARCTIC HIGH PRESSURE BUILDS SOUTH ACROSS NY. THE RESULTING WINDS AND WAVES MAY APPROACH SMALL CRAFT ADVISORY LEVELS ALONG THE EAST AND SOUTH SHORES OF LAKE ONTARIO IN THE AFTERNOON. && .CLIMATE... THE MONTHLY CLM CLIMATE SUMMARIES HAVE BEEN UPDATED TO INCLUDE THE NARRATIVE SECTION AT THE BOTTOM. THEY ARE AVAILABLE ON OUR WEBSITE UNDER THE CLIMATE SECTION. HERE ARE SOME TIDBITS BELOW... MARCH 2012 IS A MONTH FOR THE RECORD BOOKS AS AN UNSEASONABLE AND PERSISTENT WARM PATTERN REMAINED ACROSS THE EASTERN US. FOR BUFFALO MARCH FINISHED WITH AN AVERAGE TEMPERATURE OF 47.4 DEGREES WHICH IS +13.4 DEGREES ABOVE NORMAL...AND 2.9 DEGREES WARMER THAN THE PREVIOUS WARMEST MARCH. THIS 2.9 DEGREES IS THE LARGEST SEPARATION BETWEEN WARMEST...AND 2ND WARMEST FOR ANY MONTH IN BUFFALO...WITH THE NOW SECOND LARGEST SEPARATION 2.6 DEGREES FOR THE TWO WARMEST MONTHS OF SEPTEMBER. FOR ROCHESTER MARCH FINISHED WITH AN AVERAGE TEMPERATURE OF 47.3 DEGREES WHICH IS +13.0 DEGREES ABOVE NORMAL...AND 3.5 DEGREES WARMER THAN THE PREVIOUS WARMEST MARCH. THIS 3.5 DEGREES IS THE LARGEST SEPARATION BETWEEN WARMEST...AND 2ND WARMEST FOR ANY MONTH IN ROCHESTER WITH THE NOW SECOND LARGEST SEPARATION 3.1 DEGREES FOR THE TWO WARMEST MONTHS OF SEPTEMBER. FOR BOTH CITIES MARCH FINISHED WARMER THAN THE NORMAL APRIL. THE 47.4 DEGREES AVERAGE MARCH 2012 TEMPERATURE IN BUFFALO WAS 1.5 DEGREES WARMER THAN THE NORMAL APRIL VALUE. FOR ROCHESTER THE 47.3 DEGREES AVERAGE MARCH 2012 TEMPERATURE WAS 1.0 DEGREES WARMER THAN THE NORMAL APRIL VALUE. BUFFALO ESTABLISHED SEVEN NEW RECORD HIGH TEMPERATURES IN MARCH 2012...WHILE ROCHESTER ESTABLISHED THREE NEW RECORD HIGH TEMPERATURES. BOTH CITIES SET 5 NEW RECORD WARM MINIMUM TEMPERATURES. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...SMITH NEAR TERM...APFFEL/SMITH SHORT TERM...RSH LONG TERM...RSH AVIATION...APFFEL/SMITH MARINE...SMITH CLIMATE...THOMAS/HITCHCOCK
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1200 PM CDT TUE APR 3 2012 .DISCUSSION.../ISSUED AT 954 AM CDT/ LOW/MID LEVEL CLOUD DECK REMAINS ENTRENCHED ACROSS SOUTHEASTERN SOUTH DAKOTA AND BORDERING STATES THIS MORNING. 925-850MB RUC RH PROGS INDICATE EROSION OF THIS DECK SHOULD CONTINUE INTO THE EARLY AFTERNOON...ALTHOUGH EXPECT SOME RESIDUAL SCATTERED LOW/MID CLOUDS UNTIL EVENING. TEMPS STILL LOOK TO BE COOLEST IN THE SOUTHEASTERN CWA UNDER THE INFLUENCE OF THE CLOUD COVER...ALTHOUGH ABOVE NORMAL HIGHS IN THE UPPER 50S TO LOWER 60S ARE STILL ANTICIPATED. BRISK NORTHEAST WINDS WILL PERSIST THROUGH THE AFTERNOON...BUT REDUCE BELOW 10 KTS AFTER DARK. && .AVIATION.../FOR THE 18Z TAF ISSUANCE/ CIGS HAVE IMPROVED INTO THE VFR CATEGORY AT THE TAF SITES. OTHER THAN FLEETING SCT CLOUDS CIRCA 2K FEET NEAR KSUX THIS AFTERNOON...VFR CONDITIONS WITH CLEARING SKIES ARE EXPECTED. WINDS WILL CONTINUE TO BE GUSTY OUT OF THE NORTHEAST THROUGH THE AFTERNOON...GENERALLY AT SPEEDS OF 15 TO 25 KTS. MOSTLY CLEAR SKIES ARE EXPECTED TONIGHT ALONG WITH SLIGHTLY DIMINISHING WINDS TO SPEEDS AOB 10 KTS. WINDS WILL SHIFT TO MORE OF AN EASTERLY DIRECTIONAL COMPONENT FOR WEDNESDAY...AND MID/HIGH CLOUDS WILL INCREASE TOWARD KSUX AS A LOW PRESSURE SYSTEM PASSES TO THE SOUTH. PRECIPITATION ATTENDANT WITH THE LOW PRESSURE AREA IS EXPECTED TO STAY TO THE SOUTH. && .PREV DISCUSSION.../ISSUED AT 440 AM CDT/ A DECK OF LOW AND MID LEVEL STRATUS BEHIND THE SURFACE COLD FRONT CURRENTLY ENCOMPASSES MUCH OF THE AREA. SEEING A FEW LIGHT SHOWERS IN THE VICINITY OF THE 700MB FRONT...BUT THINK THESE WILL DISSIPATE BY 12Z. MAIN FORECAST ISSUE TODAY WILL BE THE ERODING OF THE CLOUD DECK AND THE ACCOMPANYING IMPACT ON HIGH TEMPERATURES. THE COMBINATION OF DAYTIME HEATING AND LOW LEVEL DRY AIR ADVECTING IN FROM THE NORTH SHOULD ACT TO SLOWLY RISE CEILINGS AND DISSIPATE THE CLOUDS FROM NORTH TO SOUTH THROUGH THE DAY. FOLLOWED A SOLUTION CLOSE TO HRRR...WHICH SEEMS TO HAVE A FAIRLY GOOD HANDLE ON THINGS. 925MB TEMPS LOOK TO BE AROUND 12C THIS AFTERNOON. THUS LOCATIONS THAT BECOME PARTLY TO MOSTLY SUNNY SHOULD GET INTO THE LOW 60S. MEANWHILE...LOCATIONS THAT GET STUCK IN THE CLOUDS WILL LIKELY REMAIN IN THE 50S. NORTHWEST IOWA AND PORTIONS OF SOUTHWEST MINNESOTA ARE THE MOST LIKELY LOCATIONS TO STAY LOCKED IN. WENT FOR HIGHS AROUND 60 IN THIS AREA GIVEN UNCERTAINTY...BUT WHERE THE CLOUDS STAY...MAY NOT REACH 60. THINKING THE WARMEST TEMPS WILL BE JUST NORTH OF THE CLOUD DECK THIS AFTERNOON...IN THE MITCHEL TO LAKE ANDES AREA...THUS RAISED HIGHS SEVERAL DEGREES THERE. WINDS WILL BE BLUSTERY TODAY OUT OF THE NORTHEAST. 900MB WINDS OF 20 TO 25KTS WILL PROMOTE WIND GUSTS UP TO AROUND 30 MPH THROUGH MUCH OF THE DAY. MOST LOCATIONS WILL BE MOSTLY CLEAR TONIGHT...EXCEPT ALONG AND SOUTH OF THE MISSOURI RIVER...WHERE CLOUDS MAY STAY LOCKED IN. HOWEVER NOT THINKING IT WILL BE A GREAT RADIATIONAL COOLING NIGHT WITH A 925MB JET OF AROUND 30KTS KEEPING THE LOW LEVELS SOMEWHAT MIXED. THUS DID NOT GO AS COLD AT THE MET GUIDANCE. DID GO ON THE COOLER SIDE OF THE RAW GUIDANCE THOUGH...WITH THE COOL EAST NORTHEAST WIND ADVECTING IN SOME COLDER AIR IN THE LOW LEVELS. NEXT FORECAST ISSUE IS THE UPPER LEVEL LOW PRESSURE SYSTEM THAT WILL MOVE ACROSS OKLAHOMA ON WEDNESDAY. THIS FURTHER SOUTH TRACK KEEPS THE BEST FORCING TO OUR SOUTH. AT THE SAME TIME...EAST NORTHEAST WINDS AROUND AN AREA OF HIGH PRESSURE OVER SOUTHERN CANADA WILL PUSH DRIER AIR INTO OUR CWA. THE COMBINATION OF THESE FACTORS SHOULD KEEP ALL THE PRECIP TO OUR SOUTH WITH THIS SYSTEM...AND THUS REMOVED POPS. THIS IS SUPPORTED BY THE NAM...ECMWF AND SREF SOLUTIONS. HIGHS WEDNESDAY WERE TRENDED WARMER GIVEN THE DRIER AND MORE SUNNY FORECAST...GENERALLY GOING WITH UPPER 50S TO LOWER 60S. WEDNESDAY NIGHT IS ANOTHER NIGHT WHICH WILL FEATURE A COOL EASTERLY COMPONENT TO THE WIND. THUS WENT ON THE COLDER SIDE OF THE RAW GUIDANCE...BUT NOT AS COLD AS MOS...WHICH APPEARS TO BE RADIATING THINGS TOO MICH. NEXT WEATHER FEATURE WILL BE A SHORTWAVE THAT CROSSES THE REGION FRIDAY NIGHT INTO SATURDAY. BEST QG FORCING WITH THIS FEATURE WILL STAY TO OUR NORTH AND ANY INSTABILITY TO OUR SOUTH. SO THINKING ANY RAIN WE GET FROM THIS WAVE WILL BE LIGHT. GIVEN THIS JUST KEPT POPS IN THE CHANCE CATEGORY FOR NOW. GIVEN THE VERY MEAGER INSTABILITY DECIDED TO REMOVE THE THUNDER WORDING FROM THE GRIDS. THE REST OF THE FORECAST PERIOD SHOULD REMAIN DRY. ECMWF IS SLOWER WITH OUR NEXT COLD FRONT THAN THE GFS...ALLOWING TEMPERATURES TO WARM NICELY ON SUNDAY. ECMWF ENSEMBLE NOT QUITE AS SLOW AND WARM AS THE OPERATIONAL...BUT STILL WARMER THAN THE GFS...THUS UPPED TEMPS A FEW DEGREES INTO THE LOW TO MID 60S. MODELS AGREE THAT THE COLDEST AIR BEHIND THE FRONT WILL BE OVER US ON MONDAY INTO MONDAY NIGHT. HOWEVER THE GFS DIGS THE TROUGH FURTHER SOUTH PUSHING IN COLDER AIR THAN THE ECMWF. ECMWF AND GFS ENSEMBLES ARE BOTH SEVERAL DEGREES WARMER THAN THEIR OPERATIONAL RUNS AT 850MB. THUS TEND TO THINK THIS WILL JUST BE A QUICK COLD SHOT WITH RIDGING QUICKLY BUILDING IN BEHIND IT ONCE AGAIN. CURRENTLY GOING WITH HIGHS IN THE 50S MONDAY...BUT GIVEN WHAT WAS JUST MENTIONED...WOULD NOT BE SURPRISED TO SEE FUTURE SHIFTS TREND THESE UP A BIT...CLOSER TO THE ECMWF VALUES. EITHER WAY...STILL WILL HAVE A CHILLY ATMOSPHERE OVER US MONDAY NIGHT...WHICH COMBINED WITH SURFACE HIGH PRESSURE OVERHEAD...SHOULD PROMOTE GOOD RADIATIONAL COOLING...AND WILL HAVE TO WATCH FOR A POSSIBLE FREEZE OVER MUCH OF THE AREA. /CHENARD && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1235 PM CDT TUE APR 3 2012 .DISCUSSION... SEE THE 18Z AVIATION DISCUSSION BELOW. && .AVIATION... VFR CONDITIONS ARE EXPECTED ACROSS WEST CENTRAL TX THROUGH THE NEXT 24 HOURS. DRY AIR ASSOCIATED WITH THE PACIFIC COLD FRONT HAS MOVED EAST OF THE TAF SITES...RESULTING IN SOME HIGH BASED CU THIS AFTERNOON GENERALLY BETWEEN 6-10 KFT. THIS CLOUD COVER WILL DIMINISH QUICKLY AROUND 00Z PROVIDING MOSTLY CLEAR SKIES OVERNIGHT. WEST WINDS WILL INCREASE TO AROUND 15 KTS AT KABI/KSJT/KSOA AND SLIGHTLY WEAKER AT KBBD/KJCT. HOWEVER...WIND SPEEDS WILL DIMINISH AROUND SUNSET AS WELL. A SECONDARY SURFACE BOUNDARY WILL MOVE ACROSS THE AREA TONIGHT...SHIFTING WINDS TO THE NORTHWEST...MAINLY AFTER MIDNIGHT. WE MAY SEE SOME LOW/MID LEVEL CIGS DEVELOP IN THE BIG COUNTRY BUT I EXPECT THIS TO REMAIN NORTH OF KABI AT THIS TIME. EQUIPMENT NOTE...KBBD CEILOMETER IS CURRENTLY NOT WORKING. THE APPROPRIATE OFFICIALS HAVE BEEN ADVISED BUT NO RETURN TO SERVICE TIME IS KNOWN. THUS...NO SKY BASED AMENDMENTS ARE EXPECTED TO BE MADE UNTIL THE EQUIPMENT IS REPAIRED. JOHNSON && .PREV DISCUSSION... /ISSUED 1116 AM CDT TUE APR 3 2012/ UPDATE... THE PACIFIC COLD FRONT HAS MOVED ACROSS MUCH OF THE CWA THIS MORNING...STRETCHING FROM NEAR MILLERS CREEK RESERVOIR...TO CROSS PLAINS...TO RICHLAND SPRINGS. A FEW SHOWERS AND THUNDERSTORMS WILL CONTINUE ALONG/EAST OF THIS FRONT THROUGH EARLY AFTERNOON BEFORE THE PACIFIC FRONT NUDGES THE AMPLE LOW LEVEL MOISTURE OFF TO THE EAST. THE SEVERE THREAT APPEARS TO HAVE ENDED FOR THE CWA WITH THE INSTABILITY AXIS SHIFTING OVER EAST TX. POPS WERE TRIMMED TO ONLY INCLUDE THE EASTERN 1/4 OF THE AREA THROUGH EARLY AFTERNOON WITH THE REST OF THE AREA REMAINING DRY. TO THE WEST OF THIS BOUNDARY...DEWPOINTS HAVE FALLEN GENERALLY INTO THE 20S AND 30S WITH CLEARING SKIES AND WEST WINDS AROUND 10 MPH. THESE WINDS WILL INCREASE TO 10-20 MPH THIS AFTERNOON...COMBINING WITH RELATIVE HUMIDITIES OF 8-15 PERCENT TO CREATE ELEVATED FIRE WEATHER CONDITIONS THIS AFTERNOON. CRITICAL THRESHOLDS SHOULD NOT BE MET AND WILL KEEP MENTION OF THIS THREAT IN THE FWF AND HWO. A FEW SPRINKLES WILL BE POSSIBLE FROM SWEETWATER TO HASKELL IN THE AREA ASSOCIATED WITH MESOSCALE ASCENT TIED TO THE UPPER JET STREAK. HOWEVER...GIVEN THE DEWPOINT DEPRESSIONS OF 50 DEGREES AS OF 11 AM AND VERY DRY SUB CLOUD LAYER...MOST...IF NOT ALL...OF THIS PRECIP WILL EVAPORATE BEFORE REACHING THE GROUND. I REDUCED SKY COVER FOR MUCH OF THE AREA TODAY AND CLEANED UP DEWPOINTS/WINDS FOR THE REMAINDER OF THE FIRST PERIOD. TEMPS LOOKED GOOD SO NO CHANGES WERE NECESSARY. JOHNSON PREV DISCUSSION... /ISSUED 701 AM CDT TUE APR 3 2012/ DISCUSSION... SEE 12Z AVIATION DISCUSSION BELOW. AVIATION... GENERALLY A VFR FORECAST TODAY WITH TEMPO MVFR CONDITIONS ASSOCIATED WITH CONVECTION THIS MORNING. LIGHT WEST TO NORTHWEST WINDS EARLY THIS MORNING WILL GUST TO AROUND 20 KT AFTER 17Z...THEN DIMINISH BY SUNSET. VFR CONDITIONS WILL PREVAIL OVERNIGHT WITH LIGHT WINDS. PREV DISCUSSION... /ISSUED 357 AM CDT TUE APR 3 2012/ SHORT TERM... POTENT UPPER LOW OVER NEW MEXICO WILL SLOWLY MOVE EAST INTO THE TEXAS HANDLE TONIGHT. PACIFIC FRONT HAS PUSHED EAST OF A JUNCTION... BRADY... ABILENE...HASKELL LINE. IT WAS STILL UNSTABLE ALONG AND AHEAD OF THE FRONT WITH RUC MUCAPES OF 2000 J/KG AND 0-6 KM SHEARS OF 40 KTS. CAN NOT RULE OUT AN ISOLATED SEVERE THUNDERSTORMS EAST OF THE PACIFIC FRONT THIS MORNING. HOWEVER...DRIER WESTERLY AIR AT THIS SURFACE WILL WORK EASTWARD BY NOON...ENDING THE SEVERE THREAT. THERE AS OUTSIDE CHANCE OF A SHOWER...AS 700 MB MOISTURE WAS WRAPPED AROUND THE UPPER THIS MORNING ACROSS WEST TEXAS. THIS IS EXPECTED TO MOVE NORTH OF THE REGION BY EARLY AFTERNOON. OTHERWISE...DRY DESERT AIR AT THE SURFACE WILL BE GUSTY AT TIMES THIS AFTERNOON...ELEVATING FIRE WEATHER CONDITIONS. LONG TERM... GUSTY WEST WINDS WILL AGAIN ELEVATE FIRE CONDITIONS WEDNESDAY AS SURFACE LOW IN NW TEXAS MOVES NE INTO CENTRAL OKLAHOMA. COOL AIR FILTERS IN WEDNESDAY NIGHT AS A WEAK COLD FRONT MOVES INTO THE REGION. LATER THIS WEEK...THERE IS STILL THE POTENTIAL FOR DRYLINE THUNDERSTORMS FRIDAY NIGHT. A COLD FRONT SATURDAY WILL ALSO BRING A CHANCE FOR THUNDERSTORMS...MAINLY SOUTH OF THE I-20 CORRIDOR. ADDED SLIGHT CHANCE OF STORMS SATURDAY NIGHT AND SUNDAY WITH LIFT OF MOISTURE OVER THE FRONT. CONFIDENCE REMAINS LOW HOWEVER SO KEPT POPS AT 20 PERCENT. FIRE WEATHER. GUSTY DRY WEST WINDS WILL ELEVATED FIRE DANGER THIS AFTERNOON AND WEDNESDAY AFTERNOON...AS A SURFACE LOW IN NW TEXAS MOVES INTO CENTRAL OKLAHOMA. WINDS SPEEDS ARE EXPECTED TO REMAIN BELOW CRITICAL LEVELS. 04 && .PRELIMINARY POINT TEMPS/POPS... ABILENE 50 81 49 83 52 / 0 0 0 0 0 SAN ANGELO 47 85 49 90 54 / 0 0 0 0 0 JUNCTION 46 87 48 91 58 / 0 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 25
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1141 AM CDT TUE APR 3 2012 .UPDATE... THE THREAT FOR THUNDERSTORMS HAS DIMINISHED IN SOUTHEAST WI UNTIL MID AFTERNOON. THE OUTFLOW BOUNDARY THAT CAUSED SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT WEAKENED AND SHIFTED INTO NORTHEAST IL. THE LINE OF MID CLOUDS...ACCAS...STRETCHING THROUGH SAUK...DODGE...FOND DU LAC AND SHEBOYGAN COUNTIES IS DUE TO WEAK CONVERGENCE ALONG THE 850MB FRONT. RUC SNDGS FOR OSHKOSH SHOW ELEVATED CAPE OVER 500 J/KG WITH A LARGE AREA OF THAT IN THE HAIL GROWTH ZONE. THE INSTABILITY DOES NOT TRANSLATE DOWN TO MADISON BUT IT IS BETTER IN MKE EARLY THIS AFTERNOON ACCORDING TO THE RUC. THE NAM STILL SHOWS SOME LIMITED ELEVATED CAPE FOR MSN AND MKE THROUGH THE AFTERNOON UNTIL THE 850MB WARM FRONT GETS SOUTH OF WI. IT LOOKS LIKE THERE WILL BE A FAIRLY NARROW WINDOW OF OPPORTUNITY TO POP A THUNDERSTORM AND IT SHOULD BE AROUND THIS 850MB CONVERGENCE BOUNDARY. THE BOUNDARY WILL SLOWLY SINK SOUTHWARD THIS AFTERNOON...EXITING SOUTHEAST WI AROUND 00Z. EXPECTING THE STRATUS CURRENTLY OVER NORTHERN WI...WHICH SEEMS TIED TO MAINLY 700MB DEFORMATION...TO SLIP SOUTHWARD THIS AFTERNOON AS THE SFC LOW TRACKS ACROSS NORTHERN IL. THIS TRANSLATION MAY NOT EXACTLY BE LINEAR AND THE STRATUS MAY NEVER REACH FAR SOUTHEAST WI BY 00Z AS THE 700MB DEFORMATION ZONE IS EXPECTED TO STALL JUST SHORT OF THE WI/IL BORDER. AT SOME POINT BETWEEN LATE THIS AFTERNOON AND EVENING...EXPECTING SE WI TO FILL IN WITH SOME STRATUS. THE NAM SHOWS STRATUS EXITING AT OR SHORTLY AFTER 00Z...BUT THIS MAY BE TOO QUICK. WITH THE SFC WINDS ALREADY CHANGED OVER TO NORTH IN THE WESTERN FORECAST AREA. THERE WILL STILL BE SOME WARMING DUE TO THE PLENTIFUL SUNSHINE...BUT WILL NEED TO ADJUST MAX TEMPS DOWN A NOTCH...ESPECIALLY IN NORTHERN AND SOUTHERN FORECAST AREAS. && .AVIATION/18Z TAFS/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD....WITH COLD ADVECTION STRATUS TO REMAIN IN THE 3500-4000 FT RANGE. THE STRATUS CLOUDS WILL BE SLOW TO ARRIVE LATE THIS AFTERNOON AND MAY NOT GET TO SOUTHEAST WI UNTIL EARLY THIS EVENING. EASTERLY WINDS WILL SHIFT TO THE NORTH- NORTHEAST LATE THIS MORNING AND INCREASE TO 10 TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS THIS AFTERNOON AS SURFACE LOW PASSES TO THE SOUTH. VERY ISOLATED CHANCE FOR THUNDERSTORMS AS THE UPPER LEVEL FRONT SINKS SOUTHWARD THIS AFTERNOON. LEFT CHANCE FOR ANY PRECIP OUT OF TAFS. && .PREV DISCUSSION... /ISSUED 408 AM CDT TUE APR 3 2012/ SHORT TERM...TODAY AND TONIGHT. FORECAST CONFIDENCE MEDIUM. ELEVATED THUNDERSTORMS THAT DEVELOPED OVER MSP EARLIER IN REGION OF STRONG LAYER FRONTOGENETIC FORCING ON NOSE OF S-SW 30-45 KT 850 MB WINDS IMPINGING ON BAROCLINIC ZONE DRAPED ACROSS NRN/CENTRAL WI. FORCING WEAKENS AS THESE WINDS WEAKEN AND VEER TO THE WEST WITH THE BEST CROSS-ISOTHERM FLOW SHIFTING EAST OF STATE BY 12Z. THIS SHIFT NOTED WITH LATEST DEVELOPMENT TO THE EAST OVER LAKE MICHIGAN...IN LINE WITH RUC AND OTHER SHORT TERM MODEL GUIDANCE. HAVE BACKED OFF POPS FOR THE ENTIRE CWA THIS MORNING...BUT COULD NOT DROP COMPLETELY THIS AFTERNOON AS COULD SEE A FEW LIGHT RAIN SHOWERS WITH CONVERGENCE ALONG BAROCLINIC ZONE AS IT MOVES SOUTH THROUGH CWA THIS AFTERNOON. SOME ELEVATED CAPE WITH BOUNDARY...BUT FORECAST SOUNDINGS SHOW A CAP BETWEEN 800 MB AND 700 MB SO WILL ONLY MENTION ISOLATED THUNDER. HIGHS TO BE REACHED LATE MORNING/EARLY AFTERNOON THEN DROP WITH COLD AIR ADVECTION WITH DEVELOPING NORTH TO NORTHEAST WINDS. 925MB TEMPS SUPPORT HIGHS IN THE MID TO UPPER 60S SOUTH AND SOUTHWEST...WITH MID UPPER 50S NORTHEAST. CLEARING FROM NORTH TO SOUTH OVERNIGHT...THOUGH A FEW CLOUDS MAY LINGER IN THE FAR SOUTH. COLD ADVECTION CONTINUES WITH LOWS DIPPING INTO THE MID 30S NORTH...AND UPPER 30S TO AROUND 40 IN THE SOUTH BY MORNING. COULD SEE SOME PATCHY FROST IN THE NORTH...BUT NOT EXPECTING ENOUGH TO MENTION FOR NOW. WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH SFC HIGH PRESSURE CENTERED JUST TO THE NORTH OF MINNESOTA WEDNESDAY MORNING WILL MEANDER SOUTHEAST TO MICHIGAN BY FRIDAY. MEANWHILE...UPPER RIDGING WILL BUILD BACK INTO THE AREA BEHIND EXITING UPPER LOW TO THE SOUTH. OVERALL...LOOKS LIKE A VERY DRY AIRMASS ACROSS SOUTHERN WISCONSIN FOR THE SECOND HALF OF THE WORK WEEK. NO PRECIP CURRENTLY EXPECTED...WITH ONLY PASSING HIGH CLOUDS AT TIMES. THOUGH SKIES WILL BE MOSTLY SUNNY...MODELS ARE INDICATING A PUSH OF COLDER AIR INTO THE STATE FROM THE NORTHEAST WEDNESDAY NIGHT INTO THURSDAY. IN ADDITION...PERSISTENT EASTERLY WINDS WILL KEEP CHILLY AIR COMING IN OFF THE LAKE. EVEN SO...HIGH TEMPERATURES WILL STILL BE NEAR NORMAL FOR EARLY APRIL...EVEN A BIT ABOVE NORMAL WEDNESDAY AND FRIDAY AWAY FROM THE LAKE. MAY SEE SOME FROST WITH LOWS TEMPS MORE TOWARD NORMAL...PARTICULARLY THU NIGHT WHEN THE WINDS WILL BE FAIRLY LIGHT. SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM MODELS SHOWING A PAIR OF WAVES TO SLIDE THROUGH SAT/SAT NIGHT AND SUN NIGHT/MONDAY. ENOUGH CONFIDENCE TO KEEP SOME POPS GOING. LOOKS LIKE HIGH TEMPS WILL BE 5 TO 10 DEGREES ABOVE NORMAL THROUGH THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK. WESTERLY LOW LEVEL FLOW MAY EVEN PUSH THE MILDER TEMPS TO THE LAKE...ESPECIALLY IF STRONG ENOUGH TO OVERCOME THE LAKE BREEZE POTENTIAL THROUGH THE DAY. AVIATION/12Z TAFS... CONVECTION HAS DEVELOPED WELL TO THE NORTH AND EAST OF TAF SITES EARLY THIS MORNING...REDUCING PROSPECTS OF SEEING ANY CONVECTION TODAY. WILL MONITOR TRENDS OVER THE NEXT FEW HOURS...BUT PLAN IS TO LEAVE ANY PRECIPITATION OUT OF 12Z TAFS. VFR CONDITIONS EXPECTED THROUGH THE PERIOD....WITH COLD ADVECTION STRATUS TO REMAIN IN THE 3500-4000 FT RANGE. EASTERLY WINDS WILL SHIFT TO THE NORTH-NORTHEAST LATE THIS MORNING AND INCREASE TO 10 TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS THIS AFTERNOON AS SURFACE LOW PASSES TO THE SOUTH. MARINE... HELD OFF ON A SMALL CRAFT ADVISORY FOR TONIGHT AS WINDS AND WAVES REMAIN JUST BELOW CRITERIA WITH WINDS EASING A BIT TONIGHT. GRADIENT TIGHTENS ON WEDNESDAY WITH WAVES BUILDING TO SMALL CRAFT CRITERIA BY WEDNESDAY NIGHT IN PERSISTENT NORTH-NORTHEAST FLOW. WAVES WILL REMAIN HIGH INTO THURSDAY...THEN LOWER WITH SHORTER FETCH AS WINDS VEER TO THE EAST AND EASE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...REM WEDNESDAY THROUGH MONDAY...DDV