AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 1001 AM MST WED MAR 23 2005 .UPDATE...ZONES HAVE BEEN UPDATED TO EXTEND PATCHY FOG FOR SEVERAL MORE HOURS AND LOWER MAX TEMPERATURES TODAY. TEMPERATURES VERY SLOW TO RISE...AND FOG REMAINING THICK IN MANY LOCATIONS. WITH HIGH PRESSURE AT SURFACE LINGERING...COLD GROUND...AND CONTINUED UPSLOPE WIND...THINK THAT COOL AIR WILL BE TOUGH TO SCOUR OUT TODAY. ETA12 HAS POOR HANDLE ON SITUATION...WHILE RUC SEEMS TO BE RIGHT ON AND SO USED IT AS A GUIDE. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ JOHNSON ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 415 PM EST WED MAR 23 2005 .DISCUSSION... MAIN FCST CONCERNS ARE -SN POTENTIAL THU INTO THU NIGHT ALONG WITH CLOUDS/TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED SPLIT FLOW ACRS NOAM WITH THE WRN GRT LAKES BTWN NRN STREAM OVER CANADA AND MORE ACTIVE SRN BRANCH THROUGH THE S AND CNTRL CONUS. MAIN UPSTREAM SHRTWV WAS DIVING SSE W OF HUDSON BAY TOWARD NRN MANITOBA. AT THE SFC...RDG EXTENDING FROM 1024 MB HIGH OVER NRN QUEBEC THROUGH THE UPR GRT LAKES INTO THE UPR MS VALLEY WAS DOMINATING FEATURE...WITH LIGHT WINDS AND DRY AIR BLO 600 MB...PER 16Z KSAW TAMDAR SNDG. VIS LOOP INDICATED AREAS OF MID CLDS OVER NRN MN AND UPR MI ASSOCIATED WITH 290K-295 ISENTROPIC ASCENT DOWNSTREAM FROM MID LVL RDGING OVER THE PLAINS. TONIGHT...UPSTREAM SATELLITE TRENDS AND NAM 700-500 MB SUGGEST VARIABLE MID CLOUDS WILL KEEP RADIATIONAL COOLING IN CHECK SO THAT TEMPS DO NOT FALL OFF QUITE AS MUCH AS PREVIOUS FEW NIGHTS. NEVERTHELESS...MIN KEPT MIN TEMPS AT OR SLIGHTLY BLO GUIDANCE VALUES. THU INTO THU NIGHT...WHILE WEAK SW FLOW DEVELOPS AHEAD OF THE SHRTWV...THICKENING MID CLOUDS SHOULD LIMIT INSOLATION ENOUGH TO KEEP TEMPS SIMILAR TO TODAY...DESPITE 900 MB TEMPS 2C-3C WARMER THAN TODAY. MDLS WERE IN REASONABLE AGREEMENT IN KEEPING BEST DEEP LYR QVECTOR CONV NORTH OF UPR MI AS THE SHRTWV MOVES THROUGH NRN ONTARIO. WHILE THE UKMET/CANADIAN/GFS ARE FASTER THAN THE NAM WITH THE SHRTWV...PREFERRED THE IDEA OF SLOWER ONSET OF KEEPING PCPN FARTHER BACK TOWARD THE COLDER AIR (GIVEN TYPICAL GFS BIAS)...WITH AMOUNT OF DRY AIR IN PLACE AND TIME TO SATURATE SFC-800 MB LYR. MDLS SUGGEST THAT BEST 800-600 FRONTOGENESIS MOVES THROUGH BTWN 21Z-03Z. MDLS SUGGEST SYNOPTIC SCALE LIFT AND DEEPER MOISTURE WILL DEPART QUICKLY OVERNIGHT. WITH DRY NRLY ACYC FLOW AND INSTABILITY...900 MB TEMPS NEAR -10C AND INVERSION HGTS AROUND 3K FT...WILL BE MARGINAL TO SUPPORT ANY LES. SO...ONLY CHANCE OF -SHSN/FLURRIES WAS MENTIONED. FRI...MID/UPR LVL CONFLUENT FLOW WILL DOMINATE WITH SFC RDG BUILDING FROM THE NRN PLAINS INTO THE UPR GRT LAKES. H9 TEMPS NEAR -10C EARLY ALONG WITH CONTRIBUTION OF LAKE MOISTURE AND UPSLOPE SHOULD BE ENOUGH TO KEEP POSSIBILITY OF FLURRIES NORTH AND SC GOING ELSEWHERE. ANY FLURRIES SHOULD AND CLOUDS WILL THIN OUT DURING THE AFTERNOON AS THE RDG BUILDS IN. NNE FLOW WILL KEEP MAX READINGS COOL NEAR LK SUPERIOR BUT SHOULD ALLOW TEMPS TO CLIMB INTO THE MID TO UPPER 30S SOUTH. SAT-WED...WHILE THE CANADIAN/UKMET SUGGEST THAT NRN STREAM SHRTWV MAY AGAIN BRUSH THE UPR GRT LAKES WITH MORE CLOUDS AND POSSIBLY SOME LGT PCPN...GENERALLY LEANED TOWARD GFS/ECMWF SCENARIO KEEPING MORE SFC RDGING ACRS THE AREA WITH MAIN BATCH OF SHRTWV ENERGY WELL TO THE NORTH. 12Z GFS/ECMWF/UKMET HAVE COME INTO BETTER AGREEMENT THAN 00Z MDLS WITH HGTS AND POSITION/TIMING OF SFC FEATURES. STILL SOME UNCERTAINTY WITH TIMING/POSITION/STRENGTH OF SHRTWV AND SFC LOW FCST BY LATE MON...BUT WILL BE ENOUGH TO WARRANT CHANCE POPS. TROF MOVING INTO THE PLAINS WOULD BRING INCREASING SRLY FLOW AND MOISTURE ADVECTION BRINGING INCREASING PCPN CHANCES TUE. MDL CRITICAL THICKNESS VALUES AND H8 TEMPS SUGGEST MAINLY RAIN BY TUE. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 900 AM EST WED MAR 23 2005 .DISCUSSION... .SHORT TERM... 12Z RAOBS/WV IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW ACRS NAMERICA WITH FA IN CONFLUENCE ZN BTWN SHALLOW NRN BRANCH TROF OVER HUDSON BAY AND MORE ACTIVE SRN BRANCH FLOW ACRS MOST OF THE CONUS. SFC RDG AXIS EXTENDING WSW FM 1027MB SFC HI PRES JUST S OF JAMES BAY ACRS LK SUP IS THE DOMINATING INFLUENCE ON WX ATTM. 12Z GRB/APX SDNGS AS WELL AS 1130Z TAMDAR SDNG FM SAW DEPICT A VERY DRY LOWER TROP...WITH JUST SOME MID/UPR LVL MSTR ON THE NRN FRINGES OF POTENT SRN BRANCH SHRTWV MOVING THRU THE OH VALLEY. SO A MID/HI OVC PRESENT ACRS THE UPR GRT LKS. A NRN BRANCH SHRTWV NOVED OVER SCNTRL SASKATCHEWAN...WITH ASSOCIATED SFC LO PRES NR LK WINNIPEG. SOME -SN ACRS NW ONTARIO ACCOMPANYING THIS SYS. MAIN FCST CONCERNS TDAY ARE CLD TRENDS/TEMPS. LATEST RUC/ETA MODELS SHOW SFC RDG AXIS REMAINING OVER THE FA THRU THE DAY. SASKATCHEWAN SHRTWV PROGGED TO SHEAR OUT THRU ONTARIO IN UPR CONFLUENCE ZN...WITH ALL ASSOCIATED PCPN REMAINING WELL N OF THE CWA. ETA IS A BIT MORE AGGRESSIVE AT INCRSG MID LVL MSTR THAN THE RUC. GIVEN PRESENCE OF UPR CONFLUENCE AND VERY DRY AIRMASS DEPICTED ON THE GRB/APX/TAMDAR SDNGS...PREFER DRIER RUC FCST. SO JUST BKN/OVC CS EXPECTED ACRS THE FA. H85 TEMPS FCST ABOUT 2C HIER TDAY BY 00Z THAN YDAY AT 00Z. ALTHOUGH HI CLD WL LIMIT INSOLATION A BIT...LOOK FOR MAX TEMPS A COUPLE NOTCHES HIER THAN YDAY AND INTO THE LO 40S ALG THE WI BORDER. WITH WEAK ESE GRADIENT FLOW IN PLACE...EXPECT LK COOLING...ESPECIALLY ALG LK MI/BAY OF GREEN BAY AND LK SUP FM THE KEWEENAW TO MQT. FEW CHGS NECESSARY TO GOING FCST...EXCEPT TO LOWER MAX TEMPS A FEW DEGREES OVER THE SCNTRL NR THE ICE COVERED GREEN BAY WHERE 90 DEGREE FLOW AT 2K FT AS OBSVD ON GRB SDNG WL ACCENTUATE LK BREEZE/COOLING. KC .LONG TERM... LATER TONIGHT INTO THU AM ATTN TURNS TO N BRANCH SHORTWAVE APPROACHING FM NW TERRITORIES. 00Z GFS AND NAM IN GOOD AGREEMENT SHOWING CDFNT MOVING THROUGH THU AFT AND EVENING...UKMET AND CANADIAN PERHAPS SLIGHTLY QUICKER. ALL MODELS SHOW MOISTURE AND PCPN POST FRONTAL...SO STILL EXPECT WED NIGHT TO BE PARTLY CLOUDY. WITH SFC RDG AND PWAT MIN AXIS LINGERING OVR THE AREA...WOULD EXPECT TEMPS AGAIN TO RADIATE DOWN LWR THAN GUIDANCE WITH SOME INLAND READINGS AGAIN IN THE SINGLE DIGITS. NRN BRANCH SHORTWAVE AND ASSOCIATED DEEPER MOISTURE AND WEAK Q-VECTOR CONVERGENCE SWING ACROSS UPR MI THU AFTN FOR W ZONES THEN REST OF CWA LATE THU AFTN-THU EVENING. NAM AND GFS STILL INDICATE SOME WEAK UPR DIVERGENCE OVER FCST AREA IN RIGHT ENTRANCE REGION OF UPR JET PASSING ACROSS ONTARIO. BEST DPVA WILL STAY NORTH OF LAKE SUPERIOR WITH PASSING VORT MAX SO WILL KEEP GOING FCST OF JUST LOW CHC POPS WEST IN AFT AND LATE AFT/EVENING FOR CNTRL AND ERN ZONES. GIVEN LATE AFT TIMING OF FRONT FOR MOST AREAS...EXPECT TEMPS TO WARM UP INTO UPR 30S/LOW 40S UNDER PARTLY SUNNY. STILL EXPECT PCPN TYPE TO STAY SNOW GIVEN EXPECTED EVAPORATIVE COOLING AND LATER ONSET OF PCPN. MODELS GENERALLY CONSISTENT SHOWING H85 TEMPS FALLING TO -10 TO -12C THU NIGHT INTO EARLY FRI WHICH COMBINED WITH LINGERING SYNOPTIC MOISTURE COULD KEEP SOME SCT SNOW SHOWERS ALONG LAKE SUPERIOR INTO EARLY FRI. FLOW BECOMES QUICKLY ANTICYLONIC BY MIDDAY FRI WITH RDGG BUILDING IN FM THE WEST. KEPT TEMPS A BIT COLDER FRI ALONG LAKE SUPERIOR WITH LINGERING CLOUD POSSIBILITY AND ONSHORE N/NE FLOW. VOSS && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION...MESOSCALE UPDATE NATIONAL WEATHER SERVICE JACKSON MS 1146 AM CST WED MAR 23 2005 .DISCUSSION... CLOUDS HANGING ON TOUGH OVER MUCH OF MY CWFA THIS MORNING. VISIBLE SATELLITE TRENDS AND RUC SOUNDINGS INDICATE THAT A SLOW DECREASE WILL CONTINUE. IN ADDITION...THE REGION REMAINS IN CYCLONIC FLOW AT THE SFC...THIS IS TYPICALLY A GOOD SIGN THAT CLOUDS WILL LINGER A BIT. HAVE UPDATED THE FORECAST TO HOLD ON TO MOSTLY CLOUDY CONDITIONS OVER MY NORTHERN ZONES...WITH SKIES BECOMING PARTLY SUNNY AROUND THE I-20 CORRIDOR AND REMAINING SUNNY IN MY FAR SOUTHERN TIER OF COUNTIES. TEMP WISE...NO CHANGES WERE MADE RIGHT NOW. MOST AREAS ARE WITHIN 5 OR SO DEGREES OF FORECAST VALUES AND ARE REASONABLE CONSIDERING CLOUD COVERAGE ISSUES. DEWPOINTS ARE RUNNING A BIT HIGHER THAN EXPECTED AND HAVE ALTERED THE HOURLY GRIDS ACCORDINGLY. PRODUCTS ALREADY SENT. && .AVIATION... 18Z TAF PACKAGES FEATURES LITTLE OVERALL CHANGE. AS MENTIONED ABOVE...STRATO CU DECK WILL LINGER A BIT LONGER THAN EXPECTED... THINNING OUT BY MID AFTERNOON AT KJAN AND KMEI AND LINGER FOR THE BETTER PART OF THE AFTERNOON AT KGLH AND KGWO. MAIN FORECAST ISSUE REVOLVES AROUND FOG POTENTIAL FOR TONIGHT. WITH DEWPOINTS REMAINING IN THE LOWER/MIDDLE 40S THUS FAR TODAY...AND NOW EXPECTED TO FOR THE REST OF THE AFTERNOON...PATCHY FOG WILL BE POSSIBLE. AS PREV FORECASTER INDICATED...KMEI AND KHBG WILL BE MOST SUSCEPTIBLE AND CONTINUED IFR VIS. STILL UNCERTAIN HOW LOW VISIBILITIES WILL GET AT THE REMAINDER OF MY TAF SITE...AND THREW A MENTION OF MVFR AT EACH AROUND SUNRISE. OTHERWISE...ANY FOG SHOULD BURN OFF BY MID MORNING LEADING TO NO VIS/CIG RESTRICTIONS TOMORROW. && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ GAGAN ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO ISSUED BY NATIONAL WEATHER SERVICE SPRINGFIELD MO 315 PM CST WED MAR 23 2005 .DISCUSSION... STRATUS LINGERED ACROSS MUCH OF THE FORECAST AREA WEDNESDAY AFTERNOON. TEMPERATURES RECOVERED INTO THE LOWER 50S IN FAR NORTHWEST MISSOURI WHERE THE SUN BROKE THROUGH...BUT READINGS WERE GENERALLY NEAR 40 DEGREES ELSEWHERE. WATER VAPOR IMAGERY AND RUC MODEL ANALYSIS DEPICTED A PROGRESSIVE LOW AMPLITUDE FLOW WITH THE NEXT UPSTREAM SHORTWAVE TRACKING ACROSS THE GREAT BASIN. SURFACE WINDS WILL SHIFT TO THE SOUTHEAST OVERNIGHT AS LEE SIDE CYCLOGENESIS TAKES PLACE OVER THE CENTRAL HIGH PLAINS. THESE WINDS AND RESIDUAL CLOUD COVER WILL ALLOW FOR ONLY MINOR TEMPERATURE FALLS TONIGHT FROM CURRENT READINGS. A LOW LEVEL JET WILL STRENGTHEN OVERNIGHT AND NOSE INTO NORTHEAST KANSAS AND WEST CENTRAL MISSOURI BY SUNRISE. THE NAM SUGGEST STRONG 850 MB WARM AIR ADVECTION AND MARGINAL ELEVATED INSTABILITY. DEEP MOISTURE AVAILABILITY IS IN QUESTION BUT GIVEN THE STRONG 850-700 MB THETA-E ADVECTION AND ISENTROPIC ASCENT...EXPECT ISOLATED TO SCATTERED ELEVATED CONVECTION DEVELOP DURING THE PREDAWN HOURS IN EASTERN KANSAS THEN MIGRATE INTO WESTERN MISSOURI. RELATIVELY STEEP MID LEVEL LAPSE RATES COULD SUPPORT SOME SMALL HAIL...BUT IT APPEARS INSTABILITY WILL BE TOO LIMITED FOR THE PRODUCTION OF SEVERE STORMS LATE TONIGHT AND THURSDAY MORNING. THE SURFACE LOW THAT DEEPENS TO OUR WEST TONIGHT WILL TRACK INTO THE REGION THURSDAY AFTERNOON. MODELS DIFFER ON THE EXACT TRACK WHICH WILL DETERMINE IF THE WARM SECTOR WILL WEDGE NORTHWARD INTO THE AREA. AT THIS TIME IT APPEARS A WARM FRONT MAY PUSH AS FAR NORTH AS I-70 THURSDAY AFTERNOON. MODELS DEPICT SUFFICIENT INSTABILITY AND LIFT IN ADVANCE OF THE APPROACHING SHORTWAVE TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON INTO THURSDAY EVENING. THERE IS A SMALL RISK OF STRONG TO SEVERE THUNDERSTORMS BUT THIS WILL BE DEPENDENT OF THE NORTHERN EXTENT OF THE WARM SECTOR. PRECIPITATION WILL PERSIST THURSDAY NIGHT AS THE SHORTWAVE SWEEPS ACROSS THE REGION. FRIDAY COULD BE SIMILAR TO TODAY WITH LINGERING STRATUS AND COOLER TEMPERATURES IN THE WAKE OF THE DEPARTING STORM SYSTEM. THE NEXT SYSTEM QUICKLY DROPS INTO THE SOUTHERN PLAINS THIS WEEKEND. MODELS HAVE TRENDED FARTHER SOUTH WHICH COULD KEEP MOST IF NOT ALL PRECIPITATION TO OUR SOUTH. OTHERWISE LOOKS LIKE A RELATIVELY COOL WEEKEND WITH VARIABLE CLOUD COVER. FOSTER && .AVIATION DISCUSSION... WIDESPREAD MVFR CEILINGS WILL GRADUALLY ERODE TONIGHT BUT WILL PERSIST LONGER AT THE KMCI AND KMKC TERMINALS. AREAS OF FOG WILL DEVELOP OVERNIGHT WHICH WILL LOWER VISIBILITIES INTO THE 3 TO 5 MILE RANGE AT TIMES. ISOLATED TO SCATTERED THUNDERSTORMS MAY DEVELOP BY SUNRISE THURSDAY MORNING. && .PREVIOUS DISCUSSION... 600 AM... LARGE SCALE SUBSIDENCE AHEAD OF APPROACHING SHORTWAVE RIDGE AXIS IS ALLOWING STRATUS DECK TO BREAK UP SOONER THAN EXPECTED ACROSS EASTERN NE/NORTHERN KS/EXTREME NORTHWEST MO. EXPECT THIS TREND TO CONTINUE...AND AS A RESULT HAVE UPDATED GRIDS/FORECAST TO ACCOUNT FOR DECREASE IN CLOUD COVER. OTHERWISE AREAS OF LIGHT DRIZZLE HAVE DEVELOPED EARLY THIS MORNING ACROSS PORTIONS OF FORECAST AREA...WITH FREEZING DRIZZLE REPORTED AT KIRKSVILLE WHERE AIR TEMPS ARE AT 32. DON'T ANTICIPATE ANY PROBLEMS AS GROUND TEMPS ARE ABOVE FREEZING...AND AIR TEMPS SHOULD RISE ABOVE FREEZING IN THE NEXT COUPLE OF HOURS. SEAMAN && .PREV DISCUSSION... 305 AM... EARLY MORNING WATER VAPOR IMAGERY AND OBJECTIVE UPPER AIR ANALYSIS DEPICT AMPLIFIED SOUTHERN STREAM ACROSS CONUS...CHARACTERIZED BY CLOSED LOW CENTERED OVER CENTRAL MO...SHORTWAVE RIDGE AXIS ACROSS SOUTHERN/CENTRAL HIGH PLAINS...AND UPSTREAM LONGWAVE TROUGH LOCATED ALONG WEST COAST. INITIAL SHORTWAVE DIGGING THROUGH BASE OF LONGWAVE OVER SOUTHERN CA...WITH SECONDARY SHORTWAVE DIGGING DOWN BACK SIDE OF LONGWAVE TROUGH ALONG WA COAST. OF ADDITIONAL NOTE IS SHORTWAVE TROUGH/VORTICITY MAXIMA LOCATED NEAR 140W ALONG NOSE OF PACIFIC JET. CLOSER TO HOME...REGIONAL RADAR TRENDS OVER PAST COUPLE OF HOURS SHOW PRECIPITATION UNDERNEATH UPPER LOW DIMINISHING RAPIDLY ACROSS CENTRAL MO...WHILE FURTHER NORTH MOISTURE WRAPPING AROUND NORTH SIDE OF UPPER LOW CONTINUES TO FEED BAND OF SNOW ACROSS IA. AS UPPER LOW BEGINS TO PULL NORTHEAST EXPECT THIS BAND TO REMAIN NORTH OF FORECAST AREA...HOWEVER WILL NEED TO CONTINUE TO MONITOR RADAR TRENDS AS CAN'T RULE OUT A BRIEF PERIOD OF SNOW ACROSS NORTHEASTERN CWA. OTHERWISE SHORTWAVE RIDGE AXIS OVER ROCKIES TO GRADUALLY BUILD EASTWARD TODAY. EXTENSIVE STRATUS DECK IN PLACE ACROSS REGION...HOWEVER AS THIS RIDGE AXIS BUILDS EAST IN WAKE OF DEPARTING UPPER LOW...ASSOCIATED SUBSIDENCE MAY ALLOW SKIES TO CLEAR BY MID/LATE AFTERNOON ACROSS FAR WESTERN CWA. BUMPED TEMPS UP ACROSS FAR NORTHWEST/WESTERN CWA INTO THE UPPER 40S...AS EVEN IF STRATUS IS SLOWER TO CLEAR TEMPS TUESDAY AFTERNOON MANAGED TO WARM INTO THE MID 40S ACROSS EASTERN NE DESPITE PERSISTENT CLOUD COVER. FURTHER EAST TEMPS SHOULD REMAIN IN THE LOW/MID 40S AROUND KIRK AND KDMO. SOUTHERN CA SHORTWAVE PROGGED TO EJECT IN TO PLAINS REGION SOMETIME THURSDAY. 06Z NAM HAS COME IN SLOWER...AND IN LINE WITH EC/UK/CANADIAN SOLUTIONS...THUS WILL LEAN TOWARDS THIS SOLUTION...WHICH IS FURTHER SOUTH WITH SURFACE FEATURES THAN GFS. STRONG WARM AIR ADVECTION ASSOCIATED WITH STRENGTHENING LOW LEVEL JET PROGGED TO DEVELOP WEDNESDAY NIGHT...THEN SHIFT EASTWARD INTO WESTERN MO LATE WED NIGHT INTO THURSDAY MORNING. HAVE KEPT MENTION OF SHOWERS/THUNDERSTORMS ASSOCIATED WITH WAA WITH HIGHEST POPS (40) ACROSS NW CWA. AS UPPER TROUGH/SURFACE LOW TRANSLATE EASTWARD THURSDAY AFTERNOON/EVENING...MOISTURE WILL GRADUALLY RETURN NORTHWARD INTO REGION. ALTHOUGH SURFACE MOISTURE WILL LIKELY REMAIN LIMITED...INCREASING MOISTURE AT 850MB COMBINED WITH MID LEVEL LAPSE RATES AROUND 7 C/KM WILL LIKELY RESULT IN PLUME OF ELEVATED INSTABILITY ACROSS CENTRAL MO. EXPECT PRECIPITATION TO REDEVELOP LATE THURSDAY AFTERNOON/THURSDAY EVENING AHEAD OF SURFACE LOW ACROSS EASTERN HALF OF CWA...AND EXPAND THURSDAY EVENING AHEAD OF APPROACHING MID LEVEL TROUGH. ALTHOUGH ANY SURFACE BASED INSTABILITY WILL LIKELY BE LIMITED TO 1000 J/KG OR LESS...COMBINATION OF ELEVATED INSTABILITY AND DEEP LAYER SHEAR WILL RESULT IN A LOW END THREAT OF LARGE HAIL. SEAMAN && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 830 PM CST WED MAR 23 2005 .DISCUSSION...PRECIPITATION APPEARS ON RADAR TO BE MOVING INTO TOWNER COUNTY ATTM AND IS PROBABLY REACHING THE GROUND AT LEAST OVER THE NORTH PORTION OF THE COUNTY. A LITTLE LIGHT SNOW IS PROBABLY FALLING ALSO AT HCO (AS IT REPORTS UP). THIS ARRIVAL IS ONLY AN HOUR LATER THAN GRIDS SHOW AND WILL MAKE THAT MINOR ADJUSTMENT. THE WIND SHIFT TO NORTHERLY PASSED GFK LAST HOUR THOUGH LOW CLOUDS ARE STRUGGLING TO ADVECT SOUTHWARD THOUGH THEY ARRIVED AT HCO SOME 5 HOURS AGO. THE SHORTWAVE RESPONSIBLE FOR THE SNOW EXPECTED TONIGHT IS STILL IN SOUTHERN SASK (VICINITY OF YYN TO YXE AND ABOUT TO GET A KICK IN MOMENTUM FROM THE SHORTWAVE MOVING SOUTHWARD IN THE NORTHERN PART OF THE PROVINCE. THESE POSITIONS ARE PRETTY CLOSE TO ETA/GFS SOLUTIONS RATHER THAN THE RUC PLACEMENT FARTHER EAST. OVERALL VERY FEW CHANGES NEEDED IN FORECASTS AND UPDATES TO BE ISSUED WITHIN 15 MINUTES OR SO. ------------------------------------------------------------------ PREVIOUS DISCUSSION .SHORT TERM... THE SFC MAP THIS AFTERNOON SHOWS A WARMFRONT EXTENDING FROM LOW PRESSURE IN WYOMING TO JUST NORTH OF DVL...THEN THE BOUNDARY BECOMES A COLD FRONT TO THE NORTHEAST WITH ANOTHER WEAK LOW IN SOUTH CENTRAL ONTARIO. A BAND OF SNOW IS ABOUT 75-100 MILES NORTH OF THE BOUNDARY IN SOUTHERN CANADA...AND VISIBILITIES ARE AROUND 3/4SM IN THE SNOW. MODELS ARE IN GOOD AGREEMENT WITH EVOLUTION OF NEXT SYSTEM TO AFFECT REGION. NAM DID A VERY GOOD JOB INITIALIZING SNOW BAND IN SOUTHERN SASKATCHEWAN AND SURFACE FIELDS. GFS ALSO DID WELL BUT LIKE THE WAY NAM BUILDS IN SFC HIGH PRESSURE THURSDAY SO WILL UTILIZE. FOR TONIGHT...EXPECT LIGHT SNOW BAND TO PROGRESS INTO NORTHERN AREAS AND MOVE SLOWLY SOUTH OVERNIGHT AS SFC BOUNDARY SAGS SOUTH. STRONG AREA OF OMEGA FROM 850-500MB ALONG WITH IDEAL DENDRITIC SNOW GROWTH ZONE...AND PRECIPITABLE WATERS AROUND 0.50 INCHES SHOULD MEAN ACCUMULATING SNOW FOR NORTHERN AREAS. IN ADDITION...850-700MB FRONTOGENESIS ALSO INCREASES IN RIGHT ENTRANCE REGION OF UPPER JET...WHICH WILL ENHANCE UPPER DIVERGENCE. WILL THEREFORE HIT SNOW CHANCES HARD IN NORTHERN AREAS AFTER 02Z THEN MOVE ACCUMULATING SNOW INTO GFK REGION AROUND 09Z THEN TO THE SOUTH THEREAFTER. WITH TEMPERATURES WARM TO START...DON/T EXPECT MUCH ACCUMULATION IN THE NORTH BUT POSSIBLY AROUND AN INCH OR SO...MAYBE A BIT MORE ALONG THE INTERNATIONAL BORDER. TEMPERATURES WILL BE COLDEST IN NORTHWEST WHERE COLDER AIR WILL FILTER IN FROM CANADA. WILL BRING A CHANCE OF SNOW INTO FAR SOUTHERN AREAS LATER TONIGHT...ALTHOUGH EXPECT MAIN SNOW BAND TO REMAIN NORTH OF HERE UNTIL TOMORROW. ON THURSDAY AND THURSDAY NIGHT...EXPECT SFC HIGH PRESSURE TO BUILD IN QUICKLY DURING THE DAY. THIS SHOULD HELP SUPPRESS SNOW BAND SOUTH OF AREA BY THURSDAY EVENING. COULD BE UP TO AN INCH IN SOUTHERN AREAS AS LOW SWINGS WELL SOUTH OF THE AREA. NORTHERLY WINDS WILL ALSO INCREASE INTO THE 15-25MPH RANGE ALONG WITH COLD ADVECTION...SO IT WILL BE MUCH COOLER THAN RECENT DAYS. WILL LINGER A LOW CHANCE FOR LIGHT SNOW IN FAR SOUTHERN AREAS UNTIL 03Z FRIDAY BEFORE DRYING/SUBSIDENCE SCOURS OUT ANY LINGERING PRECIPITATION. FOR FRIDAY AND SATURDAY...SFC HIGH PRESSURE WILL DOMINATE SENSIBLE WEATHER ALONG WITH SHORTWAVE RIDGE ALOFT. COOLEST DAY WILL BE FRIDAY WITH TEMPERATURES SLIGHTLY BELOW NORMAL. EXPECT A GRADUAL WARMING BY SATURDAY TO SLIGHTLY ABOVE NORMAL...ALONG WITH PLENTY OF LATE MARCH INSOLATION TO HELP WARM TEMPERATURES UP. .LONG TERM... SUN THROUGH WED...MODELS IN PRETTY GOOD AGREEMENT FOR EXTENDED FORECAST. 500MB RIDGE HOLDS W OF AREA...WITH WAVES RIDING THROUGH RIDGE. WARM AIR ADVECTION AHEAD OF SURFACE LOW COULD CLIP PARTS OF THE AREA WITH A CHANCE FOR SNOW ON SUN NIGHT...SO ADDED INTO FORECAST. OTHERWISE...500MB RIDGE FLATTENS TO MORE OF A ZONAL FLOW...WITH MAIN STORM TRACK REMAINING S OF THE AREA THROUGH WED. CONSEQUENTLY...LEFT THE REMAINDER OF THE FORECAST DRY. AS FAR AS TEMPS...ONLY MINOR CHANGES NEEDED...WITH TEMPERATURE REMAINING NEAR NORMAL TO SLIGHTLY ABOVE NORMAL. && .AVIATION...STATIONARY FRONTAL BOUNDARY LINGERING OVER NE ND AND NW MN IS THE DIFFERENTIATING ZONE BETWEEN VFR CLOUD COVER AND MVFR TO IFR CLOUD COVER WITH SOME PATCHY FOG. AS NIGHT PROGRESSES...EXPECT VFR CLOUD DECK TO LOWER AND BY 09Z...ANTICIPATE MVFR DECK TO OVERSPREAD THE AREA WITH LIGHT SNOW DEVELOPING AND REMAINING THROUGH THU MORNING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ KELLENBENZ/NG/GV nd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 1110 AM MST WED MAR 23 2005 .DISCUSSION...LATEST SURFACE ANALYSIS SHOWS WEAK AREA OF LOW PRESSURE NEAR GCC WITH WARM FRONT EXTENDING EASTWARD INTO WESTERN SD. COLD FRONT BOUNDARY EXTENDS FROM WESTERN ND...THRU FAR SOUTHEAST MT INTO NORTHEAST WY...AND THEN ACROSS CENTRAL WY INTO SOUTHERN ID. TEMPS HAVE DROPPED ABOUT 15 DEGREES...INTO UPPER 30S...AT GCC IN THE LAST COUPLE OF HOURS WITH LOW CLOUDS FILLING IN. REST OF CWA TO THE SOUTH AND EAST SLOWLY WARMING INTO THE 40S. ALL SHORT RANGE MODELS...INCLUDING RUC...HAVING SOME DIFFICULTY WITH LOCATION AND MOVEMENT OF FRONT AT THIS TIME. NONE OF THE MODELS HAVE THE FRONT PROGRESSING MUCH TO THE EAST THIS AFT AND KEEP MILDER AIR ACROSS REMAINDER OF CWA. WILL FOLLOW THAT TREND THRU THE AFT...BUT HAVE PUSHED COOLER AIR SLIGHTLY FURTHER EAST THAN WAS FORECASTED. SOME SHOWERS NOTED ON REGIONAL RADARS ACROSS CENTRAL WY AND SOME EXPANDING COVERAGE NEAR THE BIG HORNS. KUDX RADAR SHOWING SOME RETURNS THIS MORNING...BUT DON'T THINK MUCH MORE THAN SPRINKLES IS REACHING THE GROUND. WILL KEEP CHANCE FOR SHOWERS THIS AFTERNOON ACROSS NORTHEAST WY AND FAR WESTERN SD AS THE MOISTURE IN WY SLOWLY SHIFTS TO THE NORTH AND EAST. LOOKING AHEAD...12Z MODELS IN PRETTY GOOD AGREEMENT WITH APPROACHING SYSTEM. 700MB LOW TO TRACK ACROSS NORTHEAST WY LATE TONIGHT AND ACROSS FAR SOUTHERN SD ON THURSDAY. AMPLE LIFT AND MOISTURE IS PROGGED WITH THE SYSTEM TO PRODUCE SOME HEAVY SNOWFALL ALONG AND NORTH OF THE TRACK OF THIS LOW. FOR AFTERNOON FORECAST PACKAGE...PRELIMINARY THINKING IS TO UPGRADE TO A WINTER STORM WARNING FOR MUCH OF NORTHEAST WY...NORTHWEST SD...AND THE BLACK HILLS AREA FROM SOMETIME THIS EVENING THRU THURSDAY. MORE UNCERTAINTY ACROSS CENTRAL SD AND FAR SOUTHERN CWA AS TO TIMING OF CHANGEOVER TO SNOW...SO MAY JUST KEEP WATCH GOING THERE AND BACK OFF ON TIMING. OF COURSE...ALL THIS IS SUBJECT TO CHANGE OVER THE NEXT FEW HOURS. && .AVIATION...A COLD FRONT DROPPING INTO NORTHEASTEN WYOMING THIS MORNING WILL LEAD TO MVFR/IFR CONDITIONS WITH LOW CIGS AND AREAS OF FOG THROUGH MUCH OF THE AVIATION FORECAST PERIOD. CLOUDY SKIES WITH VFR/MVFR CIGS WILL BE FOUND ACROSS MUCH OF WESTERN SOUTH DAKOTA AND WESTERN NEBRASKA INTO THIS AFTERNOON. CONDITIONS WILL THEN START TO DETERIORATE FROM NORTHWEST TO SOUTHEAST LATE THIS AFTERNOON AND INTO THE EVENING AS A STORM SYSTEM MOVES INTO THE REGION...WITH IFR CONDITIONS EXPECTED BY LATE EVENING ACROSS MOST OF THE AVIATION FORECAST AREA. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WATCH WED NIGHT AND THU WESTERN SD. ...WINTER STORM WATCH THU AND THU NIGHT CENTRAL SD. WY...WINTER STORM WATCH WED NIGHT AND THU. && $$ ST/GR sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1055 AM CST WED MAR 23 2005 .DISCUSSION... RIDGING ALFT OVR NRN PLAINS TDA...RESULTING IN CLEARING SKIES OVERNIGHT FOR MOST OF AREA. VSBL SATELLITE PEEK WITH LACK OF CLOUDS FOR FIRST TIME A COUPLE DAYS HAS SHOWN SNOWFIELD HAS TAKEN A BIG HIT...WITH ONLY AREA ESSENTIALLY REMAINING ALONG THE HEAVIEST SNOW AXIS FROM JUST SOUTHWEST OF KFSD THROUGH MUCH OF SW MN. VERY LITTLE CONCERN TODAY WITH FCST...WITH TEMPERATURES AT FOREFRONT OF SHORT TERM...WITH A WARY EYE ON WEATHER SYSTEM THURSDAY. AS IN CASE OF LAST COUPLE OF DAYS...NAM RUNNING A DEGREE C OR TWO COLDER THAN RUC FOR LTR AFTN. DIFFERENCE TDA IS WAA...WHICH IS MORE STABILIZING AND LESS APT TO AID MIXING. WL ALSO HAVE MID TO HIGH CLOUDS INCREASING FM W DURING AFTN. HOWEVER...WITH LACK OF SNOWCOVER...WL AGAIN RAISE TMPS ALL AREAS BY A FEW DEGREES...WITH EXCEPTION OF FAR SW WHERE CLOUDS WL BE DAMPER ON MODERATION. 150M HT FALLS FOLLOWING CORE OF SWRN CLOSED LOW...WHICH EJECTS INTO PLAINS LTR TONIGHT AND THU. PRECIP EVENT FOR THU STILL SEEMS ON ORDER...AND IN FACT APPEARS THAT IF SNOWFALL COULD BE A BIT MORE SIGNIFICANT ACROSS THE NORTH AS E/W FRONTOGENETIC AXIS THREATENS TO BECOME STATIONARILY ESTABLISHED ACRS NRN BORDER. EPV DOES NOT PLAY OUT AS NEGATIVE AS ONE MIGHT EXPECT...BUT LOOK FOR NICELY BANDED PCPN NONETHELESS. WL UPDATE THE HAZARDOUS WEATHER OUTLOOK TO INDICATE MORE CERTAINTY FOR HIGHER AMOUNTS N. && .PREV DISCUSSION... FAIRLY QUIET ACRS CWA WITH PC SKIES EXPECTED. HWVR...CLOUDS WL RETURN TO THE W DURING THE AFTN. HIGH TEMPS WL BE CLOSE TO YESTERDAY'S MAX TEMPS. A FEW DEG WARMER OVR SNOW AREAS AND SLIGHLTY COOLER FAR SW CWA AS CLOUDS ROLL IN. GFS AND ETA DIFFER ON SOLUTION FOR NEXT STORM SYS LATER TONIGHT AND THU. ETA FURTHER S THAN GFS...AND GFS SEEMS TO BE THE OUTLIER. FEEL SFC WAVE WL LIKELY MOVE ACRS SRN NEB WITH INVERTED TROF OVR WRN CWA. PRECIP SHUD BEGIN TO DEVELOP LATER TONIGHT OVR WRN AND FAR SRN CWA LATER TONIGHT AND SPRD ACRS REST OF CWA ON THU. PRECIP SHUD START OUT AS RAIN...BUT THEN CHANGE TO SNOW OVR WRN CWA BY AFTN AS COOLING ALOFT TAKES PLACE TO W OF INVERTED TROF. WL NEED TO WATCH THIS ESPEC IN CANADIAN SOLUTION OCCUR WITH STRONGER MORE NEG TILTED S/W THAN EITHER GFS OR ETA. AS SFC LOW TRACK EWD THU NITE PRECIP WL LIKELY CHG TO SNOW REST OF CWA. AGAIN...WITH ETA SOLUTION...SNOW CUD ACCUM ERN CWA ALONG AND N OF I90. IF CANADIAN IS RIGHT SNOW AMOUNTS CUD BE HEAVIER ALL ALONG I90. FOR NOW WL NOT GO WITH ANY HIGHLITES DUE TO UNCERTAINTY OF TRACK BUT WITH COLD SFC HIGH POISED TO DROP S OUT OF CANADA THU A NARROW BAND OF HEAVIER SNOW IS NOT UNUSUAL WITH THIS SETUP. EVEN IF HEAVIER BAND DOES OCCUR...PBLY WL REMAIN BLO WARNING CRITERIA. MORE LIKE A 2 TO 4 INCH BAND. AFTER THIS SYS EXIT LATE THU...CAA WL HOLD TEMPS WELL BLO NORM FRI WITH A CHC OF S- E. WAA WL BEGING TO RETURN TO CWA ON SAT WITH NR NORM TEMPS W...WHILE E REMAINS BLO NORM. WARMUP ON SUN WL PBLY NOT BE AS STG AS PREV THOUGHT DUE TO POT NEWER SNOW COVER ALONG AND N OF I90...AND LOW LEVEL SELY FLOW. MON SHUD WARMUP ESPEC OVR SNOW FREE AREAS. POT FOR ANOTHER CHC OF RAIN TUES INTO WED IF LATEST GFS IS RIGHT ON WEAK S/W. FOR NOW WL NOT CHANGE FCST THAT FAR OUT. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ CHAPMAN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 915 PM CST WED MAR 23 2005 .UPDATE...LLJ BEGINNING TO INCREASE THIS EVENING AS PREVIOUSLY THOUGHT. VWP...WHICH MATCHED UP WELL WITH 00Z SOUNDING...NOW SHOWING NEAR 35 KTS JUST OFF THE DECK. 00Z CRP/BRO SOUNDINGS SHOWING DRY H925-H85 LAYER. NOT CONFIDENT ABOUT A WIDESPREAD STRATUS DECK DEVELOPING ACROSS THE ERN 2/3RDS OF THE CWA...AND LATEST RUC AND NAM DATA INDICATING LOW STRATUS FORMING FURTHER NORTH...ALONG ESCARPMENT IN THE EWX CWA. WILL ADJUST FORECAST TO JUST INDICATE PARTLY CLOUDY LATE...AS OPPOSED TO MOSTLY CLOUDY. ALSO NOT CONFIDENT ENUF DECOUPLING WILL OCCUR TO SUPPORT FOG FORMATION ACROSS THE EAST. WILL ALSO MAKE SOME MINOR ADJUSTMENTS TO TEMPS/DEW POINTS IN GRIDS...RE-ESTABLISHING CURRENT TRENDS. && .MARINE...WINDS WILL INCREASE OVER THE GULF WATERS TONIGHT AS LOW LEVEL JET INCREASES. WINDS OVER THE OFFSHORE WATERS WILL INCREASE INTO SCEC RANGE (15-20 KTS) TOWARDS AFTER MIDNIGHT. SCA CONDITIONS PROBABLE ON SUNDAY IN WAKE OF COLD FRONT. && .AVIATION...VFR CONDITIONS WILL PERSIST THROUGH THE EARLY MORNING HOURS. HOWEVER...MOISTURE WILL BEGIN TO ADVECT ALONG A 30-40 KT LLJ AT 1-3K FT BEFORE SUNRISE. AS A RESULT...PATCHY/AREAS OF STRATUS WILL FILTER INTO S TX (MAINLY EAST OF HWY 16) NEAR DAYBREAK LOWERING CIGS TO MVFR CRITERIA. BY MID-MORNING...THE LLJ WILL WEAKEN AND CIGS WILL ASCEND TO 4-6 KFT THEN SCT OUT BY EARLY AFTN INTO THE EVENING. && .CRP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 76...PUBLIC/MARINE 95...AVIATION tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 353 PM CST WED MAR 23 2005 .SHORT TERM... SURFACE WINDS REMAIN BIGGEST CONCERN IN SHORT-TERM AS LEE-SIDE SURFACE TROUGH DEEPENS THIS EVENING...THEN SHIFTS EAST ACROSS THE AREA OVERNIGHT. THIS WILL DRAG A MODERATELY STRONG LOW LEVEL JET ACROSS THE AREA WITH INTERMITTENT MIXING DURING THE NIGHT...PROBABLY MORE SO OFF THE CAPROCK EARLY THURSDAY. MODERATE FLOW ALOFT WILL RESULT IN WINDY CONDITIONS AGAIN THURSDAY. AND THE BETTER WESTERLY COMPONENT THURSDAY WITH LOWER HUMIDITIES AND STRONGER DOWNSLOPE WARMING SHOULD PUSH TEMPERATURES WELL INTO THE 70S. MORE MILD NIGHT TIME TEMPERATURES LOOK A GOOD BET THE NEXT FEW NIGHTS. WE ARE FOLLOWING THE SOMEWHAT MORE AGGRESSIVE SURFACE POSITIONS FOR THE ETA INDICATING SURFACE FRONT DROPPING THROUGH ROLLING PLAINS EARLY ON FRIDAY...WITH FRONT HANGING UP OVER CENTRAL COUNTIES UNTIL LATE IN THE DAY. RESULT WILL BE A NOTABLE NORTH-SOUTH TEMPERATURE GRADIENT ON FRIDAY. OVERRUNNING WITH A DISTURBANCE IN SOUTHERN BRANCH OF THE SUBTROPICAL JET IS ENOUGH FOR A CHANCE OF SHOWERS MAINLY ACROSS NORTHWESTERN COUNTIES FRIDAY NIGHT. MCQUEEN .FIRE WEATHER... SURFACE WINDS HAVE INCREASED AS EXPECTED...BUT HAVE MAINTAINED JUST SLIGHTLY MORE SOUTH-SOUTHEAST COMPONENT THAN WE THOUGHT EARLIER. RESULT HAS BEEN HOLDING DEWPOINTS JUST SLIGHTLY HIGHER THAN EARLIER EXPECTED SO SURFACE HUMIDITIES HAVE JUST DROPPED TO 17-20 PERCENT ACROSS WESTERN FRINGE OF THE FORECAST AREA...ACCORDING TO WEST TEXAS MESONET DATA. LATEST RUC AND MESO-ETA NOT FAR OFF SUGGESTING WESTERN BORDER WILL PROBABLY JUST BRIEFLY EXCEED RED FLAG ELEMENT CRITERIA LATE THIS AFTERNOON...BUT NOT LONG ENOUGH TO MEET THE TIME-LENGTH CRITERIA. GUSTY WINDS UP TO 35-40 MPH SHOULD TAIL OFF EARLY THIS EVENING...BUT LOW LEVEL JET WILL STRENGTHEN ACROSS THE AREA LATE IN THE EVENING. RESULT WILL BE INCREASING SURFACE WINDS TOWARDS MIDNIGHT ACROSS CENTRAL COUNTIES...SHIFTING EAST INTO ROLLING PLAINS EARLY THURSDAY. MIXING SHORTLY AFTER DAYBREAK THURSDAY MAY RESULT IN EVEN STRONGER GUSTS OVER ROLLING PLAINS...BUT HUMIDITIES LIKELY TOO HIGH TO MEET FIRE WEATHER WATCH CONDITIONS. DEEPER MIXING LATER IN THE DAY WILL MAINTAIN LOW-END WINDY DAY ON THURSDAY...BUT PROBABLY A BIT LESS WINDY OVER ROLLING PLAINS THAN EARLY IN THE DAY AFTER LOW LEVEL JET MIXES OUT. SO...THURSDAY WILL BE ANOTHER DAY OF NEAR RED FLAG CONDITIONS...BUT WE WILL HOLD OFF ON FIRE WEATHER HIGHLIGHTS FOR NOW. MCQUEEN .LONG TERM... MAIN DYNAMICS AND LOW LEVEL COLD AIR ADVECTION WILL AFFECT SOUTH PLAINS ON SAT. EXPECT SHOWERS ONGOING DURING THE MORNING AND TEMPS MAY BE COLD ENOUGH FOR A MIX FAR NW. ADDED THUNDER TO SOUTHERN/SE ZONES FOR SAT AS WELL WITH BOTH NAM AND GFS SUGGESTING MUCAPES EXTENDING ACROSS AREA WITH STEEP LAPSE RATES AND STRONG LIFT FROM APPROACHING SYSTEM. MODELS STILL HAVING DIFFICULTY REACHING AN AGREEMENT ON PLACEMENT OF SYSTEM AS IT COMES ACROSS HIGH PLAINS. LATEST NAM/OLD UKMET FURTHEREST S AND SLOWEST WITH 12Z GFS FASTER AND FURTHER N. INHERITED FCST HELD A MIDDLE OF THE ROAD APPROACH AND BASICALLY MAINTAINED THAT POSITION FOR NOW. LOOKS AS IF BEST POTENTIAL FOR SNOW WILL BE USUAL NORTHWEST CORNER SAT EVE/EARLY SUN PM WITH VERY LIMITED THREAT OFF CAPROCK. EXPECT SYSTEM TO BE FAR ENOUGH EAST TO PROVIDE A REASONABLY NICE EASTER DAY...AT LEAST BY LATE AFTERNOON. BEYOND THIS WEEKEND...ZONAL FLOW ANTICIPATED TO START THE NEW WORK WEEK WITH A SHORTWAVE AND ATTENDANT PAC FRONTAL PASSAGE TOWARD WED. THIS FEATURE LIKELY TO PROVIDE SOME MORE DRY AND WINDY DAYS AHEAD AND BEHIND IT. WENT AHEAD ALSO AND BUMPED UP TEMPS/WIND SPEEDS A BIT THROUGH TUE GIVEN DOWNSLOPE COMPONENT AND ABSENCE OF CLOUDS. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 40 72 36 58 / 0 0 10 10 TULIA 42 73 39 59 / 0 0 10 10 PLAINVIEW 44 73 41 64 / 0 0 0 10 LEVELLAND 45 75 41 66 / 0 0 0 10 LUBBOCK 46 74 42 66 / 0 0 0 10 BROWNFIELD 45 75 45 67 / 0 0 0 10 CHILDRESS 47 75 43 62 / 0 0 0 10 SPUR 48 76 47 67 / 0 0 0 10 ASPERMONT 53 79 49 71 / 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... TX...NONE. && $$ 05/24 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 236 AM MST THU MAR 24 2005 DISCUSSION...THE 09Z SURFACE ANALYSIS PLACES TWO LOBES OF LOW PRESSURE OVER COLORADO...ONE IN THE NORTHCENTRAL PART OF THE STATE AND THE OTHER IN THE SOUTHEAST CORNER. WATER VAPOR IMAGERY SHOWS A SHORTWAVE LIFTING NORTHEAST OF THE AREA AND TWO OTHER WAVES...ONE NEAR SOUTHWEST WYOMING AND THE OTHER NEAR THE SOUTHERN TIP OF NEVADA. THE MAIN FORECAST CHALLENGES ARE POPS/WEATHER AND TEMPERATURES. FOR TODAY...MAIN QUESTION IS WHAT WILL HAPPEN WITH THE FOG THIS MORNING AND WEATHER RESULTING FROM THE NEXT WAVE MOVING ACROSS THE FORECAST AREA. THE RUC MODEL INDICATES THAT CEILINGS SHOULD START INCREASING AFTER 12Z SO WOULD EXPECT FOG TO START DECREASING AT THAT TIME AND VISIBILITIES TO IMPROVE SIGNIFICANTLY BY 15Z. ETA12 ALSO INDICATES THAT BOUNDARY LAYER MOISTURE DECREASES AFTER 15Z. THE CURRENT DENSE FOG ADVISORY HAS BEEN EXPANDED IN COVERAGE TO INCLUDE THE WESTERNMOST 2 TIERS OF COUNTIES IN KANSAS/NEBRASKA AS WELL AS ALL OF THE EASTERN COLORADO COUNTIES. THE ADVISORY HAS ALSO BEEN EXTENDED IN TIME UNTIL 16Z. LATEST METARS INDICATE THAT THIS ADVISORY FITS WELL SO WILL CONTINUE AS IS. THE NEXT QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON. CEILINGS SHOULD INCREASE FOR THE AFTERNOON BUT CLOUDS WILL LIMIT ANY HEATING. THEREFORE INSTABILITY WILL ALSO BE LIMITED. THE RUC INDICATES THAT THERE WILL BE LITTLE IF ANY CAPE TO WORK WITH AND INSTABILITY IS WEAK AT BEST. CURRENT CIRCULATION OVER SOUTHWEST WYOMING WILL EJECT INTO THE PLAINS THIS AFTERNOON PROVIDING GOOD FORCING. CONSEQUENTLY CANNOT RULE OUT SOME ISOLATED THUNDER OVER WESTERN AND SOUTHERN AREAS THIS AFTERNOON AND EVENING. ANY SHOWERS THIS EVENING WILL BE FROZEN DUE TO COLDER TEMPERATURES/LOWERING THICKNESS VALUES. SUBSIDENCE WILL MOVE IN AFTER 06Z FRIDAY AND KEEP THE FORECAST AREA DRY THROUGH FRIDAY. THE NEXT SHORTWAVE MOVES INTO THE AREA AROUND 06Z SATURDAY. FOR SATURDAY...THE ETA IS SLOWER WITH THE UPPER LOW THAN THE GFS. BOTH MODELS SUPPORT A CHANCE OF SNOW OVER THE FORECAST AREA DURING THE DAY AS THE UPPER LOW MOVES INTO THE OKLAHOMA PANHANDLE AREA AND THEN DECREASING CHANCES SATURDAY EVENING AS THE LOW MOVES AWAY FROM THE AREA. FOR NOW WILL LEAVE SATURDAY EVENING DRY IN CASE THE FASTER GFS SOLUTION IS CLOSER. HAVE BUMPED UP QPF/SNOWFALL AMOUNTS BASED ON THIS SCENARIO. TEMPERATURES WILL BE DIFFICULT TODAY DEPENDING ON HOW SOON LOW CLOUDS AND FOG LIFT OUT. AT LEAST THERE WILL BE NO SNOW ON THE GROUND AND LOW TEMPERATURES WILL A FEW DEGREES WARMER THAN YESTERDAY. TEMPERATURES GRIDS HAVE BEEN LOWERED TO THE COLDEST MOS GUIDANCE. COLDER AIR MOVES INTO THE FORECAST AREA TONIGHT AS THE LOW MOVES EAST. THERE COULD ALSO BE SOME SNOW ON THE GROUND WHICH WOULD ARGUE GOING FOR THE COLDEST LOW TEMPERATURE GUIDANCE TONIGHT. EASTERLY WINDS/UPSLOPE WILL HELP KEEP CLOUDS IN PLACE ON FRIDAY AND LIMIT WARMING. CONSEQUENTLY WILL GO FOR COLDER MAV GUIDANCE. CLOUDS WILL INCREASE AGAIN FRIDAY NIGHT AND WILL HELP HOLD LOW TEMPERATURES UP SOME IN THE MID TO UPPER 20S. TEMPERATURES WILL CONTINUE COLD THROUGH SATURDAY NIGHT WITH HIGHS NEAR 40 AND LOWS IN THE MID 20S. DO NOT PLAN ANY CHANGES IN THE EXTENDED. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...DENSE FOG ADVISORY THIS MORNING WEST OF HIGHWAY 83 THROUGH 9 AM MST (10 AM CST). .NE...DENSE FOG ADVISORY THIS MORNING WEST OF HIGHWAY 83 THROUGH 9 AM MST (10 AM CST). .CO...DENSE FOG ADVISORY THIS MORNING FOR ALL OF EAST CENTRAL COLORADO THROUGH 9 AM MST. && $$ FS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 355 PM CST THU MAR 24 2005 .DISCUSSION... A RATHER ACTIVE WEATHER PATTERN IS EXPECTED OVER THE NEXT WEEK AS SEVERAL MID/UPPER LEVEL SYSTEMS MOVE OUT OF THE SOUTHERN AND CENTRAL ROCKIES. WITH EITHER AN EAST OR NORTHERLY BOUNDARY LAYER FLOW AND LOW LEVEL MOISTURE TRAPPED BELOW 850MB THERE SHOULD BE PLENTY OF CLOUD COVER. THIS WILL HAVE A NEGATIVE IMPACT ON HIGH TEMPERATURES AND HAVE THUS LOWERED HIGHS BY SEVERAL CATEGORIES FROM NOW THROUGH THE WEEKEND. SURFACE LOW OVER SOUTHEAST CO IS EXPECTED TO DEEPEN AND TRACK EAST SOUTHEAST THROUGH OK AND AR TODAY AND TONIGHT AS PRIMARY SHORTWAVE MOVES OUT INTO THE CENTRAL PLAINS. A QUASI-STATIONARY FRONT IS FORECAST TO SET UP ACROSS CENTRAL MO. STRONG ISENTROPIC LIFT ON THE 300K SURFACE IS AIDING THE FIRST BAND OF ELEVATED CONVECTION CURRENTLY OVER EASTERN KS. THIS ACTIVITY WILL SPREAD QUICKLY EAST ACROSS THE CWA THIS MORNING WITH A FEW CLAPS OF THUNDER POSSIBLE PRIMARILY SOUTH OF THE MO RIVER. A BRIEF LULL IN THE ACTIVITY IS EXPECTED DURING THE LATE MORNING AND EARLY AFTERNOON BEFORE NEW ELEVATED/WARM AIR ADVECTION CONVECTION FORMS AHEAD OF THE PRIMARY SHORTWAVE. BEST BET FOR SHOWERS WILL BE OVER EASTERN CWA WITH ISENTROPIC LIFT ALLOWING FOR PRECIPITATION TO BUILD/FORM FURTHER WEST OVER WESTERN PORTIONS OF CWA. OVERALL HAVE INCREASED POPS FOR TODAY MAINLY DUE TO ONGOING RAIN SHOWERS. BACKWASH TYPE PRECIPITATION IN WRAP AROUND CLOUD COVER SUGGESTS INCREASING POPS ACROSS NORTHERN MO TONIGHT. RESIDUAL CLOUDS/MOISTURE WILL LINGER INTO FRIDAY MORNING AND HAVE THUS INCREASED RAIN CHANCES IN THE MORNING. EXPECTING ABOUT A 10 DEGREE DIURNAL TEMPERATURE RANGE. WEEKEND SYSTEM LOOKS LIKE IT WILL TRACK FAR ENOUGH SOUTH OF CWA TO ALLOW FOR REMOVAL OF CHANCE POPS ACROSS MOST OF THE CWA. WITH THE EXPECTED LOW CEILINGS LIKELY REMAINING THROUGH SUNDAY AND AN OVERALL NORTHERLY WIND DIRECTION FEEL DIURNAL TEMPERATURE SWING WILL BE MINIMAL. GFS/CANADIAN MODELS FORECAST AN IMPRESSIVE SHORTWAVE WILL AFFECT THE CENTRAL U.S. THE MIDDLE OF NEXT WEEK. IF THIS SCENARIO UNFOLDS AS ADVERTISED BY THESE MODELS, THE POTENTIAL EXISTS FOR A SEVERE WEATHER OUTBREAK. HOWEVER...THAT IS DAY 7 AND MUCH CAN CHANGE BETWEEN NOW AND THEN. MJ && .PREV DISCUSSION... 315 PM WED... STRATUS LINGERED ACROSS MUCH OF THE FORECAST AREA WEDNESDAY AFTERNOON. TEMPERATURES RECOVERED INTO THE LOWER 50S IN FAR NORTHWEST MISSOURI WHERE THE SUN BROKE THROUGH...BUT READINGS WERE GENERALLY NEAR 40 DEGREES ELSEWHERE. WATER VAPOR IMAGERY AND RUC MODEL ANALYSIS DEPICTED A PROGRESSIVE LOW AMPLITUDE FLOW WITH THE NEXT UPSTREAM SHORTWAVE TRACKING ACROSS THE GREAT BASIN. SURFACE WINDS WILL SHIFT TO THE SOUTHEAST OVERNIGHT AS LEE SIDE CYCLOGENESIS TAKES PLACE OVER THE CENTRAL HIGH PLAINS. THESE WINDS AND RESIDUAL CLOUD COVER WILL ALLOW FOR ONLY MINOR TEMPERATURE FALLS TONIGHT FROM CURRENT READINGS. A LOW LEVEL JET WILL STRENGTHEN OVERNIGHT AND NOSE INTO NORTHEAST KANSAS AND WEST CENTRAL MISSOURI BY SUNRISE. THE NAM SUGGEST STRONG 850 MB WARM AIR ADVECTION AND MARGINAL ELEVATED INSTABILITY. DEEP MOISTURE AVAILABILITY IS IN QUESTION BUT GIVEN THE STRONG 850-700 MB THETA-E ADVECTION AND ISENTROPIC ASCENT...EXPECT ISOLATED TO SCATTERED ELEVATED CONVECTION DEVELOP DURING THE PREDAWN HOURS IN EASTERN KANSAS THEN MIGRATE INTO WESTERN MISSOURI. RELATIVELY STEEP MID LEVEL LAPSE RATES COULD SUPPORT SOME SMALL HAIL...BUT IT APPEARS INSTABILITY WILL BE TOO LIMITED FOR THE PRODUCTION OF SEVERE STORMS LATE TONIGHT AND THURSDAY MORNING. THE SURFACE LOW THAT DEEPENS TO OUR WEST TONIGHT WILL TRACK INTO THE REGION THURSDAY AFTERNOON. MODELS DIFFER ON THE EXACT TRACK WHICH WILL DETERMINE IF THE WARM SECTOR WILL WEDGE NORTHWARD INTO THE AREA. AT THIS TIME IT APPEARS A WARM FRONT MAY PUSH AS FAR NORTH AS I-70 THURSDAY AFTERNOON. MODELS DEPICT SUFFICIENT INSTABILITY AND LIFT IN ADVANCE OF THE APPROACHING SHORTWAVE TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON INTO THURSDAY EVENING. THERE IS A SMALL RISK OF STRONG TO SEVERE THUNDERSTORMS BUT THIS WILL BE DEPENDENT OF THE NORTHERN EXTENT OF THE WARM SECTOR. PRECIPITATION WILL PERSIST THURSDAY NIGHT AS THE SHORTWAVE SWEEPS ACROSS THE REGION. FRIDAY COULD BE SIMILAR TO TODAY WITH LINGERING STRATUS AND COOLER TEMPERATURES IN THE WAKE OF THE DEPARTING STORM SYSTEM. THE NEXT SYSTEM QUICKLY DROPS INTO THE SOUTHERN PLAINS THIS WEEKEND. MODELS HAVE TRENDED FARTHER SOUTH WHICH COULD KEEP MOST IF NOT ALL PRECIPITATION TO OUR SOUTH. OTHERWISE LOOKS LIKE A RELATIVELY COOL WEEKEND WITH VARIABLE CLOUD COVER. FOSTER && .AVIATION DISCUSSION... WIDESPREAD MVFR CEILINGS WILL GRADUALLY ERODE TONIGHT BUT WILL PERSIST LONGER AT THE KMCI AND KMKC TERMINALS. AREAS OF FOG WILL DEVELOP OVERNIGHT WHICH WILL LOWER VISIBILITIES INTO THE 3 TO 5 MILE RANGE AT TIMES. ISOLATED TO SCATTERED THUNDERSTORMS MAY DEVELOP BY SUNRISE THURSDAY MORNING. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 300 AM MST THU MAR 24 2005 .DISCUSSION...09Z SURFACE ANALYSIS SHOWED LOW NEAR KIEN WITH TROUGH INTO EASTERN CO AND EASTERN ND. WEST OF THIS LINE...-SN WAS FALLING. EAST OF THE LINE...-RA WAS FALLING. WATER VAPOUR HAD MAIN SHORTWAVE OVER THE WY/NE/CO BORDER. RECLUSE HAD 4 INCHES...AND GILLETTE 2 INCHES EARLIER TONIGHT. DEFORMATION ZONE STARTING TO TAKE SHAPE PER IR LOOP...AS 850-500MB FEATURE BEGINS TO CLOSE OFF. EFFECT OF THIS SYSTEM CONCERN TODAY. NAM/GFS SIMILAR IN THEIR HANDLING OF UPPER LEVEL FEATURES...WITH CLOSE OFF OF MID-LEVEL LOW IN THE NE PANHANDLE...THEN MOVING EAST THIS EVENING. 06Z RUC SUPPORTS. THIS WILL PUT BEST DEFORMATION ZONE SNOWS OVER THE WESTERN 1/2 OF THE CWA. AS SYSTEM CLOSES OFF...850-700MB EASTERLY FLOW DEVELOPS WITH FROUDE NUMBERS LESS THAN 1. THIS WILL FAVOR UPSLOPE ENHANCEMENT IN THE FOOTHILLS OF THE BLACK HILLS...AND ADJACENT PLAINS. CURRENT WARNINGS LOOK REASONABLE... ALTHOUGH ACCUMULATIONS OF 6 INCHES OR MORE IN FAR NORTHWESTERN SD MAY BE DIFFICULT TO REACH. 6 TO 9 INCHES EXPECTED ELSEWHERE. FURTHER EAST...INVERTED TROUGH FEATURE WILL SINK SOUTH AS SURFACE HIGH BUILDS OVER MT/ND. A GRADUAL CHANGEOVER TO -SN IS EXPECTED... LIKELY ALL -SN BY MIDDAY IN SOUTH CENTRAL SD. DUE TO SLOWER CHANGEOVER AND LOWER UPSLOPE ENHANCEMENT POTENTIAL...WILL UPGRADE WATCH TO ADVISORY...INSTEAD OF WARNING. GUSTY WINDS WILL DEVELOP BEHIND SURFACE LOW CREATING AREAS OF BLOWING SNOW AS TEMPERATURES HOLD STEADY OR SLOWLY FALL THROUGHOUT THE DAY. PRECIPITATION WILL WANE FROM WEST TO EAST TONIGHT. FRIDAY/SATURDAY...UPPER LEVEL SYSTEM OVER THE NORTHWEST US WILL DROP INTO THE SOUTHERN PLAINS. FLOW WILL QUICKLY BECOME SOUTHEASTERLY BRINGING A CHANCE OF PRECIPITATION TO THE FAR SOUTHWESTERN PORTIONS OF THE CWA. TEMPERATURES NEAR GUIDANCE FOR NOW...BUT AMOUNT AND EXTENT OF SNOW COVER LIKELY TO HAVE AN EFFECT. .LONG TERM...UPPER LEVEL RIDGE BUILDING OVER THE NORTHERN PLAINS WILL LEAD TO DRY WEATHER AND WARMER THAN NORMAL TEMPERATURES ON SUNDAY AND MONDAY. MONDAY EVENING RIDGE BEGINS BREAKING DOWN AS REGION RETURNS TO AN ACTIVE PATTERN FOR THE NEXT FEW DAYS. HAVE PUT PRECIP IN THE FORECAST EACH DAY ACROSS PARTS OF CWA THRU THURSDAY AS VARIETY OF SYSTEMS MOVE THRU THE AREA. UPPER LEVEL RIDGE EXPECTED TO RETURN TO THE REGION BY THE END OF THE EXTENDED. && .AVIATION...IFR/LIFR CONDITIONS ARE EXPECTED TO CONTINUE TO AFFECT KGCC & KRAP ALONG WITH ALL TWEB RTES THRU THE FORECAST PERIOD. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING THROUGH THURSDAY EVENING FOR NORTHWEST AND WEST CENTRAL SOUTH DAKOTA... ...WINTER WEATHER ADVISORY THROUGH THURSDAY EVENING FOR FAR SOUTHWEST SOUTH DAKOTA AND CENTRAL SOUTH DAKOTA... WY...WINTER STORM WARNING TODAY FOR NORTHEAST WYOMING PLAINS... ...WINTER STORM WARNING THROUGH THURSDAY EVENING FOR WYOMING BLACK HILLS AND NORTHEAST CROOK COUNTY... && $$ HELGESON/SCHILD sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 318 PM CST THU MAR 24 2005 .DISCUSSION... PRIMARY FORECAST CHALLENGES ARE PRECIPITATION TYPES/CHANCES INTO FRIDAY MORNING AND TEMPERATURES INTO NEXT WEEK. 12Z UPPER AIR ANALYSIS HAD A FEW UPPER WAVES FROM WYOMING INTO THE PACIFIC NORTHWEST WITH EARLY AFTERNOON WATER VAPOR LOOP INDICATING A SHORTWAVE TROF ENTERING WESTERN TEXAS. MID/LOWER LEVELS HAD WARM FRONT PUSHING THROUGH THE CENTRAL PLAINS WITH CONVECTION CONTINUING TO THE NORTHEAST EARLY THIS AFTERNOON...AND MOISTURE MUCH MORE PLENTIFUL THAN MODELS DEPICTED. AT 20Z...OBJECTIVE ANALYSIS HAD SURFACE LOW OVER NORTHWESTERN OKLAHOMA WITH TEMPS PUSHING 60F IN SOUTHEASTERN KANSAS. TONIGHT LOOKS TO BRING A WIDE VARIETY OF WEATHER TO THE AREA. 850MB SOUTHWESTERLY FLOW CONTINUES OVER SOUTHERN 1/2 OF THE CWA PER PROFILER DATA. 18Z RUNS OF ETA AND RUC SHOWING A FEW HUNDRED J/KG OF ELEVATED CAPE IN THE SOUTHEASTERN COUNTIES THIS EVENING BEFORE WINDS COME AROUND TO THE NORTH. LOOKS AS THOUGH WEST TEXAS WAVE WILL STAY TO THE SOUTH THOUGH MODELS AGAIN HANDLING THIS POORLY. WILL KEEP CHANCE POPS FOR THUNDER ALONG AND SOUTH OF THE TURNPIKE BEFORE MIDNIGHT. AFTERNOON SURFACE OBS AND CALLS TO LAW ENFORCEMENT INDICATE SOME DRIZZLE BEING FORCED OUT OF THE SATURATED LOWER LEVELS...AND COLD AIR ADVECTION WILL LOWER CEILINGS FROM NORTHWEST TO SOUTHEAST AND MAY CONTINUE TO SEE DRIZZLE TONIGHT. INCREASING NORTHERLY WINDS MAY HELP LIMIT THIS POTENTIAL TOWARD DAWN BUT WILL KEEP MENTION GOING INTO EARLY FRIDAY MORNING. UPPER SYSTEM TO THE NORTHWEST TO SLIDE EAST TONIGHT AND EXIT FRIDAY MORNING. EXPECT MOST OF THE ASSOCIATED PRECIPITATION TO STAY TO THE NORTH BUT WILL KEEP LOW POPS GOING. AS PREVIOUS SHIFT NOTED...MID LEVEL MOISTURE IS LACKING AND WILL MAKE SNOW PRODUCTION DIFFICULT...BUT HAVE ENOUGH DOUBTS IN SPECIFICS TO CONTINUE TO MENTION SNOW FRIDAY MORNING. STRATUS TO PERSIST ON INTO FRIDAY WITH COLD AIR ADVECTION KEEPING WARMING IN CHECK...AND KEPT DIURNAL CHANGE LESS THAN 10 DEGREES. NORTHWESTERN SYSTEM CONTINUES TO LOOK TO REMAIN TO THE SOUTHWEST OF THE CWA FOR THE WEEKEND. GFS TRIES TO BRING AN ODD LOOKING VORT MAX INTO CENTRAL KANSAS SATURDAY BUT THIS WAS DISCOUNTED. WILL THUS REMOVE ANY MENTION OF PRECIP THROUGH EARLY NEXT WEEK. LOW CLOUDS WILL CONTINUE TO DOMINATE THE SKIES HOWEVER AND WITH COOL AIR BEING REINFORCED...SEE LITTLE REASON TO GO WITH ANYTHING LESS THAN MOSTLY CLOUDY SKIES INTO SATURDAY AFTERNOON. ETA SUGGESTS SOME DRYING WILL OCCUR LATE SATURDAY AND INTO SUNDAY AND WILL LEAN THAT WAY FOR NOW. SHOULD BEGIN TO SEE WARM AIR RETURN SUNDAY WITH UPPER HEIGHTS RISING...BUT TEMPERED THE INCREASE IN THE SOUTHEASTERN COUNTIES WITH LOW LEVEL RH LINGERING. TEMPS STILL ON TRACK TO RETURN TO ABOVE NORMAL LEVELS EARLY NEXT WEEK WITH PACIFIC FRONT/UPPER TROF ENTERING THE AREA TUESDAY. PRETTY DECENT AGREEMENT WITH NEARBY IN THE LATE TUESDAY TO EARLY WEDNESDAY TIME FRAME BUT STILL TOO MUCH TO PIN DOWN ANY SPECIFIC PERIOD YET. DEEP MOISTURE APPEARS TO BE LACKING AT THIS TIME WITH NORTHERLY 850MB WINDS THROUGH SOUTHEAST TEXAS INTO MONDAY...BUT WILL NEED TO BE MONITORED. THURSDAY LOOKING DRY WITH NEAR NORMAL TEMPS. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 65 ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 950 AM MST THU MAR 24 2005 .UPDATE...FORECAST HAS BEEN UPDATED TO REMOVE DENSE FOG ADVISORY HEADLINES...ALSO TO CHANGE WORDING TO INCLUDE PATCHY FOG FOR THE REST OF THE MORNING. LOWERED MAX TEMPS A CATEGORY...AND UPDATED WINDS AND DEWPOINTS TO ACCOUNT FOR REALITY. && .PREV DISCUSSION... (ISSUED 236 AM MST THU MAR 24 2005) DISCUSSION...THE 09Z SURFACE ANALYSIS PLACES TWO LOBES OF LOW PRESSURE OVER COLORADO...ONE IN THE NORTHCENTRAL PART OF THE STATE AND THE OTHER IN THE SOUTHEAST CORNER. WATER VAPOR IMAGERY SHOWS A SHORTWAVE LIFTING NORTHEAST OF THE AREA AND TWO OTHER WAVES...ONE NEAR SOUTHWEST WYOMING AND THE OTHER NEAR THE SOUTHERN TIP OF NEVADA. THE MAIN FORECAST CHALLENGES ARE POPS/WEATHER AND TEMPERATURES. FOR TODAY...MAIN QUESTION IS WHAT WILL HAPPEN WITH THE FOG THIS MORNING AND WEATHER RESULTING FROM THE NEXT WAVE MOVING ACROSS THE FORECAST AREA. THE RUC MODEL INDICATES THAT CEILINGS SHOULD START INCREASING AFTER 12Z SO WOULD EXPECT FOG TO START DECREASING AT THAT TIME AND VISIBILITIES TO IMPROVE SIGNIFICANTLY BY 15Z. ETA12 ALSO INDICATES THAT BOUNDARY LAYER MOISTURE DECREASES AFTER 15Z. THE CURRENT DENSE FOG ADVISORY HAS BEEN EXPANDED IN COVERAGE TO INCLUDE THE WESTERNMOST 2 TIERS OF COUNTIES IN KANSAS/NEBRASKA AS WELL AS ALL OF THE EASTERN COLORADO COUNTIES. THE ADVISORY HAS ALSO BEEN EXTENDED IN TIME UNTIL 16Z. LATEST METARS INDICATE THAT THIS ADVISORY FITS WELL SO WILL CONTINUE AS IS. THE NEXT QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON. CEILINGS SHOULD INCREASE FOR THE AFTERNOON BUT CLOUDS WILL LIMIT ANY HEATING. THEREFORE INSTABILITY WILL ALSO BE LIMITED. THE RUC INDICATES THAT THERE WILL BE LITTLE IF ANY CAPE TO WORK WITH AND INSTABILITY IS WEAK AT BEST. CURRENT CIRCULATION OVER SOUTHWEST WYOMING WILL EJECT INTO THE PLAINS THIS AFTERNOON PROVIDING GOOD FORCING. CONSEQUENTLY CANNOT RULE OUT SOME ISOLATED THUNDER OVER WESTERN AND SOUTHERN AREAS THIS AFTERNOON AND EVENING. ANY SHOWERS THIS EVENING WILL BE FROZEN DUE TO COLDER TEMPERATURES/LOWERING THICKNESS VALUES. SUBSIDENCE WILL MOVE IN AFTER 06Z FRIDAY AND KEEP THE FORECAST AREA DRY THROUGH FRIDAY. THE NEXT SHORTWAVE MOVES INTO THE AREA AROUND 06Z SATURDAY. FOR SATURDAY...THE ETA IS SLOWER WITH THE UPPER LOW THAN THE GFS. BOTH MODELS SUPPORT A CHANCE OF SNOW OVER THE FORECAST AREA DURING THE DAY AS THE UPPER LOW MOVES INTO THE OKLAHOMA PANHANDLE AREA AND THEN DECREASING CHANCES SATURDAY EVENING AS THE LOW MOVES AWAY FROM THE AREA. FOR NOW WILL LEAVE SATURDAY EVENING DRY IN CASE THE FASTER GFS SOLUTION IS CLOSER. HAVE BUMPED UP QPF/SNOWFALL AMOUNTS BASED ON THIS SCENARIO. TEMPERATURES WILL BE DIFFICULT TODAY DEPENDING ON HOW SOON LOW CLOUDS AND FOG LIFT OUT. AT LEAST THERE WILL BE NO SNOW ON THE GROUND AND LOW TEMPERATURES WILL A FEW DEGREES WARMER THAN YESTERDAY. TEMPERATURES GRIDS HAVE BEEN LOWERED TO THE COLDEST MOS GUIDANCE. COLDER AIR MOVES INTO THE FORECAST AREA TONIGHT AS THE LOW MOVES EAST. THERE COULD ALSO BE SOME SNOW ON THE GROUND WHICH WOULD ARGUE GOING FOR THE COLDEST LOW TEMPERATURE GUIDANCE TONIGHT. EASTERLY WINDS/UPSLOPE WILL HELP KEEP CLOUDS IN PLACE ON FRIDAY AND LIMIT WARMING. CONSEQUENTLY WILL GO FOR COLDER MAV GUIDANCE. CLOUDS WILL INCREASE AGAIN FRIDAY NIGHT AND WILL HELP HOLD LOW TEMPERATURES UP SOME IN THE MID TO UPPER 20S. TEMPERATURES WILL CONTINUE COLD THROUGH SATURDAY NIGHT WITH HIGHS NEAR 40 AND LOWS IN THE MID 20S. DO NOT PLAN ANY CHANGES IN THE EXTENDED. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ JOHNSON ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 440 PM EST THU MAR 24 2005 .DISCUSSION... MAIN FCST CONCERNS ARE -SN/-SHSN POTENTIAL TONIGHT INTO EARLY FRI ALONG WITH CLOUDS/TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED SPLIT FLOW PATTERN ACRS NOAM WITH THE UPR GRT LAKES ON THE SRN PERIPHERY OF THE NRN BRANCH. MORE ACTIVE ZONAL SRN STREAM DOMINATED MOST OF THE SOUTH AND CNTRL CONUS. NRN STREAM SHRTWV WAS LOCATED N OF LK SUPERIOR WITH TRAILING VORT AXIS INTO NRN MN. AT THE SFC...COLD FRONT EXTENDED FROM LOW PRES E OF JAMES BAY TO NEAR KCMX-KIWD AS 1031 MB HI FROM SASK INTO THE NRN PLAINS IN ITS WAKE. VIS LOOP SHOWED BACK EDGE OF DEEPER MOISTURE WAS ALREADY APPROACHING THE KEWEENAW LEAVING BANDS OF INSTABILITY SC AND SOME FLURRIES FARTHER TO THE NW IN THE COLDER AIR WHERE TEMPS HAVE FALLEN INTO THE MID 20S. ASSOCIATED DPVA / 850-500 QVECTOR CONV SUPPORTED AN AREA OF -SN ACRS LK SUPERIOR INTO NW UPR MI WITH 1-2SM VSBY REPORTED AT KCMX. WHILE RADAR SHOWED RETURNS OVER MUCH OF UPR MI...MOST OF THE RETURNS REMAINED ALOFT AS VERY DRY AIR BLO 700 MB PER 12Z KGRB AND LCL TAMDAR SNDGS...HAVE KEPT -SN FROM REACHING THE SURFACE. TONIGHT...RADAR/SATELLITE TRENDS AND 12Z/18Z NAM SUGGEST BULK OF QG FORCING AND PCPN WILL REMAIN N OF UPR MI. HOWEVER...DYNAMICS SHOULD BE SUFFICIENT TO SATURATE LOWER LVL ENOUGH OVER THE N HLF TO BRING AT LEAST SOME PATCHY LIGHT SNOW OR FLURRIES. EXPECT BAND OF SYNOPTIC -SN TO MOVE THROUGH QUICKLY THIS EVENING AS THE COLD FRONT EXITS THE EAST BTWN 00Z-03Z. MDLS HAVE TRENDED A BIT COLDER BY 06Z WITH H8 TEMPS FCST NEAR -12C TO -14C OVER S CNTRL LK SUPERIOR. WHILE SIGNIFICANT DRYING/SUBSIDENCE DEVELOP ABOVE INVERSION NEAR 3K FT...INSTABILITY COMBINED WITH LINGERING 20 KT CBL NRLY FLOW SHOULD BE ENOUGH TO KEEP AT LEAST SCT -SHSN GOING OVER THE NORTH. UPSLOPE AREAS OF N CNTRL UPR MI WOULD SEE BEST CHANCE AT PICKING MARGINAL ACCUMULATIONS...LESS THAN AN INCH. OTHERWISE...RDG BUILDING INTO WRN LK SUPERIOR AND W UPR MI SHOULD BRING SOME CLEARING OVERNIGHT. FRI...ANY LINGERING FLURRIES OVER THE NORTH WILL END EARLY AS THE SFC RDG CONTINUES TO BUILD INTO UPR MI AND THE WINDS BECOME LIGHT WRLY. SUNSHINE BY AFTERNOON SHOULD HELP PUSH TEMPS AOA GUIDANCE VALUES. GENERALLY LIGHT DECOUPLED WINDS WITH THE RDG AXIS SAGGING JUST S OF THE AREA WILL BRING GOOD RADIATIONAL COOLING ALLOWING TEMPS TO FALL BLO GUIDANCE VALUES INLAND. SAT INTO SUN...PLENTY OF SUNSHINE ALONG WITH WEAK WSW WINDS EXPECTED WILL PUSH TEMPS AGAIN AOA GUIDANCE INTO THE LOWER TO MID 40S OVER MUCH OF THE AREA. MDLS DEPICT ANOTHER NRN STREAM SHRTWV MOVING THROUGH NRN ONTARIO...DRAGGING A WEAK TROF/FRONT THROUGH LK SUPERIOR. TRAILING BAND OF WEAK 700-300 QVECTOR SHOULD RESULT IN LITTLE MORE THAN A BAND OF MID CLOUDS INTO THE AREA SAT NIGHT. MON-THU...MDLS STILL HINT AT POTENTIAL OF ANOTHER NRN STREAM SHRTWV BRUSHING THE AREA MON WITH CHANCE FOR SOME LIGHT PCPN. WITH MDL H8 TEMPS AND CRITICAL THICKNESS VALUES WOULD SUGGEST POSSIBILITY OF EITHER RAIN OR SNOW WITH WARMING AND RISING HGTS BUILDING IN TOWARD TUE. ECMWF/GFS/UKMET WERE SIMILAR IN DEVELOPING TROF OVER THE WRN CONUS AND DOWNSTREAM RDGING INTO THE GRT LAKES. -RA CHANCES RETAINED FOR TUE...BUT BETTER WAA AND INCREASING MOISTURE ADVECTION DEVELOP MORE TOWARD MID WEEK. 12Z ECMWF/UKMET SUGGEST POSSIBILITY OF STRONGER NEG TILT SHRTWV EMERGING FROM THE PLAINS THAT WITH INFLOW OF GULF MOISTURE COULD BRING MODERATE RAINFALL INTO THE WRN GRT LAKES. WARMUP WOULD LIKELY BE TEMPERED BY SUBSTANTIAL CLOUD COVER AND SOME FOG NORTH OF DEVELOPING WARM FRONT. NEVERTHELESS...RAIN WITH WARMER TEMPS COULD BRING ENOUGH SNOWMELT FOR SOME MINOR FLOODING OR ICE JAMS. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 328 PM EST THU MAR 24 2005 .SHORT TERM... TONIGHT AND FRIDAY MODELS THROUGH THE SHORT TERM OVERALL SIMILAR. AT 500 MB...BROAD SHORTWAVE RIDGE FLATTENED BY NORTHERN STREAM SHORTWAVE TROUGH TRAVERSING NORTHERN LAKES REGION TONIGHT...WITH THE SHORTWAVE ENERGY FROM THE WEST TO ENTER CONFLUENT FLOW AND STAY PRIMARILY SOUTH OF FORECAST AREA. ASSOCIATED SURFACE LOW TRACK EXPECTED TO STAY WELL SOUTH OF THE AREA...FAR TO THE SOUTH PER MOST MODELS THOUGH RUC13 FARTHER NORTH...BUT CONSENSUS IS THAT INCOMING RIDGE BUILDING IN FROM THE CANADIAN PRAIRIES WILL BE INSTRUMENTAL IN SUPPRESSING TRACK WELL TO THE SOUTH. MAIN QUESTION...THEN..IS HOW MUCH PRECIPITATION CAN REACH NORTH INTO SOUTHEAST MI TONIGHT AND FRIDAY. PREFER A BIT OF COMPROMISE AMONG MODELS HERE...AS SEVERAL MODELS BRING NO MEASURABLE QPF AT ALL INTO AREA. WILL LIMIT MEASURABLE MENTION TO SOUTHERN 4 COUNTIES...AS HIGH AS 50 PERCENT POPS...AND MOSTLY SNOW AS PER MODEL SOUNDINGS...THOUGH SOUTHERN BORDER COUNTIES STAND THE BEST CHANCE OF MIX LATE TONIGHT. EVEN THERE...THOUGH...THERE IS A DEEP DRY LAYER TO OVERCOME WITH WET BULB TEMPERATURES LOW ENOUGH TO PULL THE TEMPERATURE SOUNDING BACK FOR PROBABLY MOSTLY SNOW. REGARDLESS...NOT CALLING FOR MORE THAN ABOUT AN INCH OF SNOW EXTREME SOUTH IN GRIDS. 850 TO 500 MB LAYER VERY DRY INITIALLY...MOISTENING MAINLY SOUTH LATE TONIGHT BEFORE DEEPER MOISTURE GETS SUPPRESSED SOUTHWARD DURING FRIDAY. 700 MB OMEGA LIFT LATE TONIGHT INTO FRIDAY WILL BE VERY MODEST FAR SOUTH...FOLLOWED BY LOW TO MID LEVEL SUBSIDENCE BUILDING IN FRIDAY AFTERNOON...ALLOWING CLOUDS TO DECREASE FROM THE NORTH. 850 TO 500 MB QVECTOR CONVERGENCE SLIGHT LATE TONIGHT INTO FRIDAY AS PER MODEL CONSENSUS AS WELL...AGAIN MAINLY FAR SOUTH...AND SAME CAN BE SAID FOR SLIGHT FRONTOGENESIS AS PER NAM/NGM AND SLIGHT 850 TO 700 MB DEFORMATION AND UPPER DIVERGENCE AT 250 MB. ALSO...WEAK RIGHT ENTRANCE REGION OF UPPER JET LATE TONIGHT INTO FRIDAY MAY PROVIDE SOME LIFT. && .LONG TERM... FRIDAY NIGHT THROUGH THURSDAY A SPLIT UPPER FLOW PATTERN WILL REMAIN IN PLACE ACROSS THE CONUS THROUGH THE WEEKEND. THE MAIN FORECAST CONCERN ACROSS THE EASTERN CONUS WILL BE A DEEPENING SOUTHERN STREAM TROUGH SET TO MOVE ACROSS THE SOUTHERN MISSISSIPPI VALLEY ON SUNDAY. IN THE MEANTIME... SURFACE HIGH PRESSURE WILL BUILD ACROSS SE MICHIGAN FROM THE NORTH FRIDAY NIGHT. THIS SYSTEM WILL ADVECT VERY DRY AIR IN THE 800 TO 500MB LAYER. THE NAM/GFS/CANADIAN/UKMET ALL SUPPRESS THE DEEP MOISTURE AND LINGERING LIFT ALONG THE BAROCLINIC ZONE SOUTH OF THE STATE FRIDAY EVENING. THE RUC13 HOWEVER IS MUCH HIGHER WITH DEEP LAYER MOISTURE AND ACTUALLY PRODUCES A COUPLE HUNDREDS OF AN INCH QPF ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA. WILL LEAN TOWARD MODEL CONSENSUS AND MAINTAIN A DRY FORECAST FRIDAY NIGHT INTO SATURDAY. THERE IS REASONABLE AGREEMENT AMONG MODEL SOLUTIONS THAT SOME WEAK SHORT WAVE ENERGY WILL MOVE FROM IOWA ACROSS SOUTHERN LOWER MI ON SATURDAY. NOT ENOUGH LIFT OR MOISTURE LOOKS TO BE PRESENT TO WORRY ABOUT PRECIP. THE ETA HOWEVER IS A BIT STRONGER WITH THIS WAVE AND THUS TRIES TO BRING IN MORE MID LEVEL MOISTURE IN COMPARISON TO OTHER MODEL SOLUTIONS. WITH LINGERING CONFLUENT FLOW ALOFT OVER THE GREAT LAKES... WILL LEAN TOWARD THE GFS MOISTURE PROFILES AND CARRY PARTLY CLOUDY SKIES SAT INTO SAT NIGHT. THERE IS SOME DISAGREEMENT AMONG MODEL SOLUTIONS IN THE HANDLING OF THE WAVE TO PASS THROUGH THE DEEP SOUTH LATE THIS WEEKEND. THE GFS SOLUTION IS FARTHER NORTH AND FASTER IN COMPARISON TO THE NAM AND EUROPEAN SOLUTIONS. IN FACT... THE 12Z GFS ACTUALLY BRINGS SOME MEASURABLE PRECIP INTO THE SOUTHERN PORTIONS OF THE FORECAST AREA SUNDAY NIGHT. WILL LEAN TOWARD MODEL CONSENSUS WHICH INDICATES THIS WAVE WILL DIG FARTHER SOUTH THAN THE CURRENT GFS SOLUTION AND THUS KEEP ALL PRECIP SOUTH OF THE STATE SUN THROUGH MON. THE WAVE WILL MOVE INTO THE ATLANTIC COAST BY EARLY NEXT WEEK. THERE IS VERY GOOD AGREEMENT THAT THE FLOW ALOFT OVER THE CONUS WILL BE RATHER PROGRESSIVE NEXT WEEK. A LONG WAVE RIDGE WILL BUILD ACROSS THE GREAT LAKES EARLY IN THE WEEK... WHILE A TROUGH WILL AMPLIFY ACROSS THE CENTRAL US TOWARD THURSDAY. THERE HAS BEEN TREMENDOUS INCONSISTENCY WITH RESPECT TO HOW THIS TROUGH WILL IMPACT THE GREAT LAKES LATE NEXT WEEK. THE 00Z GFS AND DGEX SHOWED QUITE A BIT OF PHASING BETWEEN THE NORTH STREAM AND SOUTHERN STREAM... LEADING TO A STRONG LOW PRESSURE SYSTEM MOVING THROUGH THE WESTERN GREAT LAKES ON THURSDAY. MEANWHILE... THE 12Z GFS SHOWS LESS PHASING AND HENCE A LITTLE WEAKER SYSTEM. GFS ENSEMBLE MEMBERS DO NOT OFFER MUCH GUIDANCE AS THERE IS A HUGE VARIANCE ON POSSIBLE SOLUTIONS. AT THIS POINT... WILL JUST ADD A LOW CHANCE OF RAIN SHOWERS TO THURSDAY GIVEN THE UNCERTAINTY. THERE WILL HOWEVER BE SOME FAIRLY GOOD WARM AIR ADVECTION EARLY NEXT WEEK AHEAD OF THIS SYSTEM. WILL ACTUALLY TAKE FORECAST TEMPS ABOVE NORMAL MON THROUGH WED. IF THE APPROACHING LOW LATE NEXT WEEK ENDS UP BEING FAIRLY DEEP... STRONG SURFACE ADVECTION COULD ACTUALLY PUSH TEMPS WELL ABOVE NORMAL BY THE MIDDLE OF NEXT WEEK. && .AVIATION... ISSUED AT 1247 PM FIRST ORDER OF BUSINESS WILL BE TO ERODE AWAY THE STUBBORN LOW CLOUDS IN THE EASTERN AND SOUTHERN COUNTIES. SATELLITE IMAGERY SHOWS THIS EROSION IS UNDERWAY...AND LATE MARCH SUN SHOULD PRETTY WELL MIX THE REST OUT IN NEXT COUPLE OF HOURS OR SO. FNT ON THE EDGE OF LOW CLOUDS...BUT COULD SEE BROKEN MVFR CEILING ANOTHER HOUR OR SO...DTW AND ESPECIALLY DET MAY TAKE AS LATE AS 21Z TO LOSE LOW CEILING. OTHERWISE EXPECT VFR...EXCEPT WILL MENTION CHANCE/PROB GROUP IN DET AND DTW FROM 13Z TO 17Z OF MVFR WITH CEILINGS 2 THOUSAND FEET AND VISIBILITIES 3 MILES IN LIGHT SNOW. STILL QUITE QUESTIONABLE HOW FAR NORTH PRECIPITATION WILL INTRUDE LATE TONIGHT AND FRIDAY. MODEL CONSENSUS AT 12Z SHOWS FAR SOUTHWARD TRACK WITH LOW...THOUGH RUC13 SHOWS FARTHER NORTH THAN CONSENSUS AND THUS MORE QPF...BUT EVEN RUC DOES NOT REACH FNT OR MBS WITH MEASURABLE PRECIPITATION. MODEL SOUNDINGS...ESPECIALLY FROM DTW/DET NORTHWARD...SUPPORT SNOW TYPE OF PRECIPITATION AS WELL. && .DTX WATCHES/WARNINGS/ADVISORIES... .MI...NONE. .LAKE HURON...NONE. .LAKE ST CLAIR...NONE. .MI WATERS OF LAKE ERIE...NONE. && $$ DWD/CONSIDINE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1247 PM EST THU MAR 24 2005 .AVIATION... FIRST ORDER OF BUSINESS WILL BE TO ERODE AWAY THE STUBBORN LOW CLOUDS IN THE EASTERN AND SOUTHERN COUNTIES. SATELLITE IMAGERY SHOWS THIS EROSION IS UNDERWAY...AND LATE MARCH SUN SHOULD PRETTY WELL MIX THE REST OUT IN NEXT COUPLE OF HOURS OR SO. FNT ON THE EDGE OF LOW CLOUDS...BUT COULD SEE BROKEN MVFR CEILING ANOTHER HOUR OR SO...DTW AND ESPECIALLY DET MAY TAKE AS LATE AS 21Z TO LOSE LOW CEILING. OTHERWISE EXPECT VFR...EXCEPT WILL MENTION CHANCE/PROB GROUP IN DET AND DTW FROM 13Z TO 17Z OF MVFR WITH CEILINGS 2 THOUSAND FEET AND VISIBILITIES 3 MILES IN LIGHT SNOW. STILL QUITE QUESTIONABLE HOW FAR NORTH PRECIPITATION WILL INTRUDE LATE TONIGHT AND FRIDAY. MODEL CONSENSUS AT 12Z SHOWS FAR SOUTHWARD TRACK WITH LOW...THOUGH RUC13 SHOWS FARTHER NORTH THAN CONSENSUS AND THUS MORE QPF...BUT EVEN RUC DOES NOT REACH FNT OR MBS WITH MEASURABLE PRECIPITATION. MODEL SOUNDINGS...ESPECIALLY FROM DTW/DET NORTHWARD...SUPPORT SNOW TYPE OF PRECIPITATION AS WELL. && .UPDATE... ISSUED 1026 AM EST THU SATELLITE IMAGERY REVEALS LOW CLOUDS OVER EASTERN AND MUCH OF SOUTHERN COUNTIES OF FORECAST AREA VERY RELUCTANT TO THIN. 12Z MODEL SOUNDINGS AS PER NAM DO INDICATE ENOUGH MIXING TO PRETTY WELL THIN OUT THESE CLOUDS EARLY IN THE AFTERNOON. MEANWHILE...HIGHER CLOUDS AHEAD OF NEXT SYSTEM ARE THICKENING OVER THE WESTERN LAKES REGION AND WILL INCREASE OVER SOUTHEAST MI ESPECIALLY TOWARD EVENING. HAVE UPDATED GRIDS AND WILL REFRESH WORDING OF TEXT FORECAST TO ACCOUNT FOR CLOUD TRENDS. && .SHORT TERM... TODAY AND TONIGHT... ISSUED AT 310 AM THU RESIDUAL CYCLONIC FLOW IN THE LOW LEVELS OVER THE EASTERN GREAT LAKES IS DOING A GOOD JOB OF MAINTAINING A LAYER OF STRATUS OVER MOST OF SE MICHIGAN EARLY THIS MORNING. AT THE SAME TIME, SOME HIGH CLOUDS ARE SPILLING OVER THE SHORT WAVE RIDGE THAT IS SET UP ALOFT OVER THE WESTERN GREAT LAKES. THIS SHORT WAVE RIDGE WILL INDUCE SOME MID LEVEL SUBSIDENCE OVER SE MICHIGAN THAT WILL INHIBIT MIXING OF THE LOW LEVEL STRATUS LAYER AND FORCE US TO WAIT UNTIL THE SURFACE RIDGE AXIS SLIDES THROUGH THE AREA TO GET RID OF THE LOW CLOUDS. THIS WILL BE AS LATE AS MID AFTERNOON BETWEEN PORT HURON AND DETROIT. BY THEN, A HEALTHY COVERAGE OF MID AND HIGH CLOUDS WILL TAKE THE PLACE OF THE STRATUS. PARTLY SUNNY WILL BE THE BEST WE CAN DO IN OUR AREA TODAY, AND THAT WILL BE AROUND THE TRI CITIES DURING THE MORNING. THE COMBINATION OF A CHILLY START IN THE TRI CITIES AND THE LOW CLOUD COVER IMPACTS AROUND DETROIT WILL KEEP HIGH TEMPS QUITE UNIFORM OVER SE MICHIGAN TODAY. PREFER THE COOLER VERSIONS OF THE 00Z GUIDANCE NUMBERS EXPECTING LOWER 40S TO BE THE TOP END OF THE RANGE. CLOUDS WILL THICKEN AND LOWER THROUGH TONIGHT AS THE NEXT SET OF LOW PRESSURE SYSTEMS APPROACH THE AREA. THE LOW OVER NORTHERN ONTARIO AND ITS COLD FRONT TRAILING INTO LOWER MICHIGAN OVERNIGHT WILL HOOK UP WITH THE NEXT SOUTHERN STREAM SYSTEM MOVING INTO THE LOWER OHIO VALLEY. THE COMBINATION OF THE COLD FRONT AND THE ADVANCING LOW LEVEL THETA-E ADVECTION ASSOCIATED WITH THE SOUTHERN SYSTEM IS WORTH A CHANCE OF SNOW AFTER MIDNIGHT, IN LINE WITH OUR GOING FORECAST, AND POSSIBLY A LITTLE RAIN/SNOW MIX NEAR THE OHIO BORDER. MODEL FORECAST SOUNDINGS SHOW JUST ENOUGH WARM AIR LINGERING IN THE BOUNDARY LAYER AHEAD OF THE FRONT FOR A RAIN CHANCE. && .LONG TERM... ISSUED AT 310 AM EST THU MODELS HAVE BEEN FAIRLY CONSISTENTLY PUSHING THIS NEXT SOUTHERN SYSTEM FARTHER SOUTH EACH RUN. BEHIND THE NORTHERN STREAM COLD FRONT...HIGH PRESSURE BUILDS INTO THE NORTHERN LAKES REGION ON FRIDAY. DEEP MOISTURE IS ONLY OVER SOUTHEAST MICHIGAN FOR THE MORNING AND INTO THE EARLY AFTERNOON...AT MOST. THE MOISTURE WILL HOLD ACROSS THE FAR SOUTH THE LONGEST. BESIDES THAT INCREASE IN MOISTURE AND THETA-E PROFILES...NOT MUCH ELSE ACROSS SOUTHEAST MICHIGAN. THERE IS SOME DECENT UPPER DIVERGENCE ON FRIDAY FROM BOTH THE RIGHT REAR ENTRANCE OF A JET TO THE NORTHEAST AND THE LEFT FRONT EXIT REGION OF 100+ KT JET ACROSS THE MID MS AND OHIO RIVER VALLEYS. FAR SOUTHEAST LOWER DOES GET BRUSHED WITH THE QVECTOR CONVERGENCE AREA AS A COUPLE OF 500 MB SHORTWAVES MOVE QUICKLY TO THE SOUTH OF THE STATE IN THE CONFLUENT FLOW. THEREFORE WILL LOWER POPS ON FRIDAY TO A CHANCE...EXCEPT NEAR THE OHIO BORDER WITH LIKELY POPS FOR MONROE AND LENAWEE. WITH THE FARTHER SOUTH SOLUTION...THERE IS MORE COLD AIR IN THE COLUMN WHICH WILL SUPPORT MORE LIGHT SNOW IN THE FORECAST. INITIALLY...THE DRY AIR IN THE LOW LEVELS WILL HELP TO COOL THE BOUNDARY LAYER EARLY FRIDAY...BUT THEN DIURNAL INFLUENCES...AWAY FOR THE BETTER PRECIP RATES...WILL WARM THAT BOUNDARY LAYER JUST ENOUGH TO ADD THE POSSIBILITY OF RAIN MIXING WITH THE SNOW. AGAIN...PRECIP WILL BE LIGHT SO ACCUMULATIONS SHOULD BE LESS THAN AN INCH ON FRIDAY. WITH THE STRONGER HIGH MOVING INTO THE GREAT LAKES A BIT QUICKER...WILL DROP ALL POPS FOR FRIDAY NIGHT. BOTH NAM AND GFS INDICATE SOME 500 TO 300 MB MOISTURE...ESPECIALLY OVER THE SOUTH HALF OF THE CWA...SO WILL BE SLOW TO EVEN HAVE PARTIAL CLEARING. SATURDAY WILL BE DRY WITH THE SURFACE RIDGE OVER THE GREAT LAKES. THE LEFT OVER 500 TO 300 MB MOISTURE FROM THE FRIDAY SYSTEM WILL PEEL AWAY LEAVING MOSTLY CLEAR SKIES FOR MOST OF SATURDAY NIGHT...BEFORE MORE HIGH CLOUDS MOVE OVER FAR SOUTHEAST LOWER ON SUNDAY AS THE NEXT SOUTHERN SYSTEM PASSES TO OUR SOUTH. WILL GO LOWER WITH TEMPS ON FRIDAY. DO NOT EXPECT AS MUCH OF A STRONG NORTHEAST WIND ON FRIDAY AS ON WEDNESDAY...BUT WITH CLOUDS... SOME PRECIP AND THAT NORTHEAST WIND...EXPECT TEMPS TO REACH THE MID AND UPPER 30S AT BEST. BESIDES THAT THE GUIDANCE TEMPS AND THE PREVIOUS FORECAST TEMPS ARE IN LINE FOR FRIDAY NIGHT AND SATURDAY...SO COULD NOT SEE ANY REASON TO CHANGE. IN THE EXTENDED...ALL MODELS INDICATE THAT THE NEXT SYSTEM FOR SUNDAY AND MONDAY MAKES A MOVE TOWARD THE GREAT LAKES...BUT GETS PUSHED MORE TO THE EAST...INSTEAD OF NORTHEAST...AS THE NEXT SHORTWAVE DIVES INTO THE SOUTHWEST U.S. IT DOES APPEAR THAT ALL THE MODELS INDICATE...WITH SOME CONSISTENCY TOO...THAT A 500 MB SHORTWAVE RIDGE BUILDS INTO THE GREAT LAKES IN THE MID WEEK IN RESPONSE TO THE DIGGING SHORTWAVE IN THE SOUTHWEST. WITH SOME SOUTHERLY SURFACE WINDS...TEMPS COULD BE HEADING (WELL?) ABOVE AVERAGES IN THE MIDDLE OF NEXT WEEK. WILL NOT CHANGE THE EXTENDED AT THIS POINT AND KEEP THE SLOW MODERATING TEMPERATURE TREND. && .DTX WATCHES/WARNINGS/ADVISORIES... .MI...NONE. .LAKE HURON...NONE. .LAKE ST CLAIR...NONE. .MI WATERS OF LAKE ERIE...NONE. && $$ DWD/BT/RBP mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 240 PM CST THU MAR 24 2005 .DISCUSSION... COLD FRONT MAKING PROGRESS INTO NORTHWEST OKLAHOMA THIS AFTERNOON. SHORT RANGE MODELS (RUC) HAVE COLD FRONT EXTENDING FROM JUST NORTH OF PONCA CITY TO NEAR GUTHRIE AND THEN ALONG I-40 CORRIDOR BY 00Z WITH DRYLINE EXTENDING SOUTH FROM FRONT NEAR GUTHRIE. LIMITED SURFACE BASED INSTABILITY WILL CONTINUE TO INCREASE AHEAD OF DRYLINE THIS AFTERNOON BUT DEEP LAYER SHEAR WILL STILL BE MORE THAN SUFFICIENT FOR SEVERE STORMS. RUC HAS BEEN FAIRLY CONSISTENT IN INDICATED NORTH CENTRAL AND SOUTH CENTRAL PARTS OF THE STATE AS POSSIBLE AREAS FOR DEVELOPMENT. FAIRLY SHORT WINDOW OF OPPORTUNITY FOR SEVERE WEATHER AS ANY STORM THAT DEVELOPS WILL MOVE QUICKLY EAST OF FA THIS EVENING. AFTER FRONT PUSHES SOUTH OF AREA FRIDAY MORNING...WINDS WILL REMAIN NORTH TO EASTERLY OVER THE WEEKEND. STILL APPEARS THAT RAIN CHANCES WILL BECOME LIKELY GOING INTO THE WEEKEND AS NEXT SYSTEM DEVELOPS AND MOVES ACROSS THE SOUTHERN PLAINS. BY 00Z SUNDAY MODELS SOMEWHAT SIMILAR WITH PLACEMENT OF UPPER LOW OVER WEST TEXAS. COULD SEE AREAS NORTH OF THE LOW...MAINLY WEST CENTRAL AND NORTHWEST OKLAHOMA HAVE PRECIP CHANGE TO OR MIX WITH SNOW SATURDAY NIGHT INTO EARLY SUNDAY MORNING. AIR TEMPS ARE EXPECTED TO BE MARGINAL FOR ANY ACCUMULATION AND SOIL TEMPS WILL REMAIN WELL ABOVE FREEZING. AFTER THIS SYSTEM DEPARTS THE AREA ON SUNDAY...APPEARS THAT NEXT CHANCE FOR SPRING-TYPE WEATHER WILL BEGIN LATE TUESDAY INTO WEDNESDAY WITH DRY CONDITIONS ON THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 44 57 41 47 / 20 10 30 70 HOBART OK 43 57 40 45 / 10 10 30 60 WICHITA FALLS TX 47 66 45 50 / 10 10 30 60 GAGE OK 35 50 35 39 / 10 10 30 60 PONCA CITY OK 42 55 39 46 / 30 0 20 60 DURANT OK 51 68 46 53 / 30 10 30 80 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ SIX ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1031 AM CST THU MAR 24 2005 .UPDATE... THE SURFACE LOW APPEARS TO BE CENTERED OVER EXTREME NORTHWEST OKLAHOMA... BETWEEN BUFFALO AND WOODWARD... LATE THIS MORNING. A WARM FRONT EXTENDS EAST TOWARD PONCA CITY. THE LATEST RUC FORECASTS AN ALMOST DIRECT SOUTH MOVEMENT OF THESE FEATURES OVER THE COURSE OF THE DAY... WITH THE WARM FRONT GRADUALLY BECOMING A COLD FRONT AS THE ENTIRE SYSTEM BEGINS TO SHIFT SOUTH. MEANWHILE... LOW-LEVEL MOISTURE CONTINUES TO FLOW NORTH INTO CENTRAL AND EASTERN OKLAHOMA. MODEL FORECASTS SHOW A MODEST AMOUNT OF INSTABILITY AND SOME WIND SHEAR THIS AFTERNOON... GENERALLY ALONG AND JUST EAST OF I-35. WE WILL BE WATCHING THIS AREA FOR THUNDERSTORM DEVELOPMENT TOWARD MID-AFTERNOON. A DRYLINE OVER WEST TEXAS WILL MOVE EAST THIS AFTERNOON... AND SHOULD REACH SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS... PROBABLY EXTENDING FROM NEAR ELK CITY TO LAWTON TO WICHITA FALLS BY LATE AFTERNOON. THIS SHOULD CAUSE RED FLAG WARNING CRITERIA TO BE MET WEST OF THE DRYLINE. THESE CONDITIONS MAY NOT BE MET IN THE EASTERN EDGE COUNTIES IN THE RFW - STEPHENS AND JEFFERSON - BUT DUE TO UNCERTAINTY IN THE FINAL POSITION OF THE DRYLINE... WE WILL LEAVE THEM IN THE WARNING FOR NOW. THE UPDATE THIS MORNING WILL ADJUST WEATHER FEATURES TO ACCOUNT FOR THE LATEST FORECAST POSITIONS OF THE SURFACE WEATHER FEATURES - MAINLY AFFECTING WINDS AND TEMPERATURES NEAR THE FRONTAL SYSTEM. && .PREV DISCUSSION... (ISSUED 421 AM CST THU MAR 24 2005) DISCUSSION... ANOTHER WAVE MOVES INTO THE CENTRAL PLAINS. THIS ONE LOOKS TO TRACK A BIT FARTHER NORTH THAN THE ONE ON MONDAY. STILL COOL MID- LEVEL TEMPERATURES /-22 OR SO AT 500 MB/ WILL GIVE A SOMEWHAT UNSTABLE ATMOSPHERE DEPENDING ON HOW MUCH LOW LEVEL MOISTURE WE CAN GET TO MOVE NORTH... SO HAVE EXPNADED POPS A LITTLE BIT FARTHER WEST. BUT THE LOW-LEVEL MOISTURE IS FARTHER DOWN IN TEXAS THAN ON MONDAY WITH THE 50 DEWPOINTS ONLY UP TO COLLEGE STATION AND DEL RIO. SO DESPITE THE EXPANDED AREA OF POPS... WILL KEEP THEM AT 20S WITH THE BEST CHANCE WITHIN THAT IN THE SOUTHEAST. DRYLINE WILL MOVE INTO THE AREA FROM THE WEST AND COLD FRONT FROM THE NORTHWEST. THIS WILL GIVE THE POST-DRYLINE SECTOR IN THE SOUTHWEST WARM/DRY/BREEZY CONDITIONS AND WILL DECIDE LATER THIS MORNING ON IF A RED FLAG WARNING IS NECESSARY. MORE SIGNIFICANT WAVE STILL SCHEDULED TO ARRIVE THIS WEEKEND. HAVE EXPANDED THE LIKELY POPS FARTHER NORTHWEST INTO CENTRAL OKLAHOMA ON SATURDAY. && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 23/06 ok