AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1035 PM EDT SUN JUN 11 2000 MAIN FORECAST CONCERNS ARE CLOUDS AND FOG POTENTIAL. 01Z SFC ANALYSIS SHOWS 1028MB HIGH CENTERED NEAR N ONTARIO WITH RIDGE EXTENDING SOUTH ACROSS UPR MI. COOL...MOIST NORTH FLOW OFF LAKE SUPERIOR LEADING TO FOG ACROSS THE HIGHER TERRAIN AND TEMPS IN THE 40S ACROSS MOST OF CWA. 00Z KGRB/KAPX SOUNDINGS SHOW BASE OF SUBSIDENCE INVERSION AROUND 850MB. KAPX SOUNDING COMPLETELY SATURATED BELOW H85 WHILE KGRB SOUNDING SHOWS DEWPOINT DEPRESSIONS AOB 2C FROM 925MB TO 875MB. LAST FADING VIS IMAGES SHOW EXTENSIVE CLOUDS OVER EASTERN HALF OF UPR MI AND ALONG LAKE SUPERIOR COUNTIES IN WEST. IR IMAGERY ALSO SHOWS SOME CONVECTIVE BLOW-OFF FROM IOWA MOVING TOWARDS UPR MI. RUC/MESOETA KEEP RIDGE IN PLACE OVERNIGHT... SO LOW LEVEL MOISTURE WILL REMAIN IN PLACE UNDER SUBSIDENCE INVERSION. FORECAST GENERALLY ON TRACK WITH CLOUDS...WITH EXCEPTION OF WESTERN COUNTIES WHERE LOW CLOUDS ARE MORE PREVALENT (KIWD OVC003 AT 02Z) AND HIGH CLOUDS APPROACHING FROM SOUTH. FOG HAS NOT BEEN TOO EXTENSIVE SO FAR TONIGHT. KCMX HAS REMAINED P6SM WITH OVC007 FOR SEVERAL HOURS AND ONT HAS 10SM VIS. ONE CHANGE FROM PREVIOUS COUPLE NIGHTS IS LACK OF PRECIP FALLING OVER THE LAKE WITH FOG CONSEQUENTLY ADVECTING INLAND. EXPECT PATCHY FOG TO CONTINUE...ESPECIALLY ALONG HIGHER TERRAIN...WHICH IS ALREADY HANDLED IN FORECAST. TEMPS IN GOOD SHAPE. MAY TWEAK TEMPS UP A LITTLE FROM IMT TO MNM...WHERE FORECAST LOWS APPEAR TOO LOW BASED ON CURRENT TREND/DEWPOINTS AND LAMP GUIDANCE. .MQT...NONE. JS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 930 PM EDT SUN JUN 11 2000 THE GOING FORECAST LOOKS ON TRACK FOR THE OVERNIGHT HOURS... SO UPDATE WILL PRIMARILY BE COSMETIC. LATEST SURFACE OBS AND MSAS ANALYSIS PLACE THE FRONT OVER THE CENTRAL CWFA... EXTENDING FROM NEAR CHICAGO TO HOLLAND TO FLINT. THE FRONT SHOULD CONTINUE TO SAG SOUTH THROUGH THE NIGHT AS HIGH PRESSURE WORKS SOUTH INTO THE AREA. WITH THE FRONT MOVING SOUTH... THE BEST CHANCE OF ANY LINGERING PCPN WILL SHIFT SOUTH AS WELL. SOME ELEVATED INSTABILITY WILL REMAIN OVER THE SOUTHERN CWFA THROUGH THE NIGHT... AS INDICATED BY 850-500MB DIFFERENTIAL THETA-E PROGS FROM THE RUC. HOWEVER... WITH 850MB RH DECREASING FROM NORTH TO SOUTH OVERNIGHT... IT WILL BECOME INCREASINGLY DIFFICULT TO TAP INTO ANY OF THIS CONVECTIVE INSTABILITY. IT APPEARS THAT THE MAIN CHANCE OF ANY PCPN OVERNIGHT WILL BE SOUTH OF I-96... AND PRIMARILY SOUTH OF I-94. WILL GO WITH A DRY OVERNIGHT IN THE NORTH... MENTION A CHANCE OF PCPN EARLY OVER THE CENTRAL COUNTIES... AND LEAVE A CHANCE OF PCPN THROUGH THE NIGHT OVER THE SOUTH. A MOSTLY CLOUDY OR CONSIDERABLY CLOUDY WORDING SHOULD COVER THINGS. ZONES WILL BE OUT BY 1000 PM. TRH .GRR...NONE. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1059 AM EDT SUN JUN 11 2000 THE LATEST APX 88D SHOWS SCATTERED SHOWERS AND THUNDERSTORMS OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA...MAINLY SOUTH OF M-72. STLT LOOP AND SURFACE OBSERVATIONS FROM AROUND THE ENTIRE GREAT LAKES REGION SHOWS LOW CLOUDS... FOG AND DRIZZLE NORTH OF THE SURFACE BOUNDARY WITH SCATTERED SHOWERS AND THUNDERSTORMS TO THE SOUTH OF THE BOUNDARY. THE LATEST SURFACE CHART AND MSAS DATA SHOWS THE BOUNDARY RUNNING NEARLY EAST/WEST BETWEEN APX AND TVC. THE MAIN FORECAST CONCERN THIS AFTERNOON WILL BE CENTERED AROUND THE MOVEMENT OF THIS BOUNDARY AND THEREFORE THE CLOUDS...TEMPERATURES AND PRECIPITATION ASSOCIATED WITH IT. THE LATEST RUC AND MESO ETA DATA SHOWS THIS BOUNDARY REMAINING NEARLY STATIONARY BETWEEN TVC AND APX THIS AFTERNOON WITH COOL NORTHEAST TO EAST FLOW NORTH OF THE BOUNDARY... AND HUMID SOUTHWEST FLOW TO THE SOUTH OF THE BOUNDARY. THIS BOUNDARY... PLUS A 500 MB VORT CENTER MOVING TOWARD THE STATE THIS AFTERNOON... WILL ACT AS TRIGGERS THIS AFTERNOON FOR THE CONTINUED CHANCES OF SHOWERS AND THUNDERSTORMS FOR LOCATIONS SOUTH OF M-72 IN THE MOIST UNSTABLE AIR. MODIFIED RUC MODEL SOUNDINGS SHOWS 850 DEW PTS AROUND 12C WITH SURFACE DEW PTS IN THE LOW 60S...WITH STABILITY INDICES SHOWING LI'S TO -4 WITH CAPES AROUND OR UNDER 500 J/KG SOUTH OF THE BOUNDARY. THEREFORE WILL KEEP A MENTION OF SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR THE SOUTHERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON. FOR LOCATIONS NORTH OF THE SURFACE BOUNDARY...MODEL SOUNDINGS SHOW A STRONG LOW LEVEL INVERSION IN PLACE ALL AFTERNOON WITH ABUNDANT MOISTURE TRAPPED BELOW THE INVERSION WITH NORTHEAST FLOW. THEREFORE WILL KEEP THE MENTION OF CLOUDY SKIES AND SOME DRIZZLE AND FOG... AND WILL DROP AFTERNOON HIGHS ALL LOCATIONS NORTH OF THE BOUNDARY. .APX...NONE. SWR mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 905 PM EDT SUN JUN 11 2000 ANOTHER ROUND OF ACTIVE CONVECTION ACRS THE BGM CWA. WIND DAMAGE WAS CNTRD ALONG A LINE ACROSS CHEMUNG-TIOGA-BROOME AND DELAWARE COUNTIES. 88D REVEALED INTERESTING INTERACTIONS BETWEEN OUTFLOWS AND ALSO SHOWED IMPRSV MID LVL CONVERGENCE SIGNATURES WITH THE STRONGER STORMS...WHICH EVENTUALLY BOWED OUT AND PRODUCED THE DAMAGING WINDS. NICE CASE TO ARCHIVE. CONVECTION HAS BEEN SLOWLY WINDING DOWN BUT WE'LL HAVE TO KEEP CHC POPS FOR SCT CONVECTION FOR THE REMAINDER OF THE NGT MOST AREAS. FNT IS ONLY MAKING SLOW PROGRESS SWD WITH RUC INDICATING IT STILL N OF THE SRN TIER AT 09Z. SAT PIX SHOWING ALOT OF LOW CLDS ACRS THE ERN LAKES. AS FOR TEMPS...LOTS OF MAXES IN THE 50S N OF THE FNT ACRS ONTARIO AND NRN NY TDA. IF CLDS STICK ARND TMRW...AND IT IS LOOKING MORE AND MORE LIKE THEY WILL...THEN WE COULD BE MUCH COOLER (10-15F) THAN CRNTLY FCST...SPCLY OVER NY ZONES. BEST CHCS FOR ANY DECENT AMT OF SUN STILL APPEARS TO BE OVER FAR NRN SXNS. GIVEN THE SLOW MVMNT OF THE FNT...AND THE ETA/NGM PROFILES WHICH SHOW PLENTY OF LOW LVL MSTR BLO 800 MB PERSISTING MUCH OF THE DAY...WILL BE A BIT MORE PESSIMISTIC WITH THE SUNSHINE FOR TMRW AND MAY TWEEKS TEMPS DOWN A BIT...BUT WILL LEAVE MORE SIG CHGS (IF NEEDED) FOR THE MID SHIFT. THANX TO CTP/PHL/BUF FOR RADAR/FCST COORDINATION TDA. MUCH APPRECIATED. .BGM...NONE. BRADY ny FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 837 PM CDT SUN JUN 11 2000 ...SEVERE WEATHER THREAT OVERNIGHT FORECAST CONCERNS... STRONG 700 WAA COMBINED WITH 850/BL MOIST CONV KEEPING CONVECTION GOING THIS EVENING. BOUNDARY/PSEUDO WARM FRONT DRAPED NW/SE FROM NEAR MOT TO FAR ACTING AS OVERRUNNING FOCAL POINT. SODAK TSRA DECREASING AS NODAK TSRA INCREASING IN 850 MOIST CONV AXIS. OVERALL CELLS MOVING IN LINE WITH 700-300 MB FLOW. WITH STRONG 700 WAA AND INCREASING LOW LEVEL FLOW EXPECT CONVECTION TO CONTINUE INTO THE OVERNIGHT. RUC ALSO SHOWS GOOD 850 MB MOIST CONV AXIS MOVING SLOWLY ACROSS WEST HALF CWFA BY MORNING. STEEP 850-700 AND 700-500 LAPSE RATES ALSO SUGGEST SEVERE CONVECTIVE POTENTIAL WILL REMAIN. INCREASING 850 JET WILL ASSIST. WILL MAKE MINOR WORDING CHANGES FOR TIMING OTHERWISE ONGOING FCST PACKAGE LOOKS TO HAVE GOOD HANDLE. EXPECT TO ADD MENTION OF SEVERE OVERNIGHT BASED ON ABOVE REASONING AND SPC 0130Z UPDATE. WW IN EFFECT TIL 03Z. .FGF...WW428 TIL 03Z. EWENS nd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 225 PM CDT SUN JUN 11 2000 MODELS ARE IN PRETTY GOOD AGRMT ON THE LARGE SCALE FEATURES FOR THE NEXT 5 DAYS. UPR RDG OVR AREA TO BE REPLACED BY BROAD TROF BY MIDDLE OF THE WEEK. FIRST WK SHRTWV IN NWRN NE LOOKS TO BE HANDLED BEST BY ETA. THIS WV IS PRODUCING STG TSRA THIS AFTN IN KVTN AREA...AND IT IS PROGGED TO MOV NEWD OVRNGT INTO NERN AND E-CNTRL SD. QUICK LOOK AT THE RUC AND LAPS SHOWS FAR SWRN ZONES IN CWA ARE VERY UNSTABLE... AND THE WAY THINGS ARE DEVELOPING IN NRN NE...WL MENTION PSBL SVR THIS EVNG WITH HAIL BEING THE MAIN THREAT. EWD MOVEMENT OF SHRTWV IS VERY SLOW THOUGH. ANOTHER SHRTWV IN NERN KS AND SERN NE SHUD NOT HAVE MUCH AFFECT ON CWA AS IT SLIDES SLOWLY NEWD. THE STGST WAV WL BE MOVG EWD THRU THE NRN RCKYS AND INTO THE AREA MON NGT AND TUE. LOW LVL MSTR AND WARMER TEMPS WILL RETURN ON MON HELPING TO INCRS CHC OF WIDESPREAD TSRA MON NGT AND TUE. THEN THE EXTENDED MODELS START SHOWING BIGGER DIFFERENCES FOR WED THRU FRI. THEY DO AGREE ON GNRL NW FLOW ALF THANKS TO HUDSON BAY LOW...BUT TIMING AND STRENGTH OF SHRTWVS MOVG THRU THE NW FLOW ARE ANYBODY'S GUESS. WITH COLDER AIR ALF ATMS WL BE FAIRLY UNSTABLE...SO WL BROADBRUSH CHC NGTTM TSRA IN EXTENDED...BUT THERE DOESN'T LOOK TO BE ANYTHING TOO MAJOR AS FAR AS PCPN AMOUNTS GO FOR THE LAST HALF OF THE WEEK. FAN AND FWC TEMPS NOT MUCH DIFFERENT AND SEEM REASONABLE. TEMPS MON SHUD BE ABOUT 5 DEGS WARMER THAN TODAY...AND THEN BACK 5 TO 10 DEGREES COOLER AFT TRANSITION ON TUE THANKS TO NW FLOW. .FSD...NONE MBG sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 900 PM EDT SUN JUN 11 2000 LTST RUC/MESOETA KEEP DEEP LAYER MOISTURE/SFC BNDRY N OF CWA TONGT. XPCTNG ONLY FEW-SCT MID-HI LVL BLOW OFF FM CNVCTN US OVER NRN COUNTIES...OTRW A TYPICAL SUMMER NIGHT...LOWS IN THE UPR 60S INLD TO LOW TO MID 70S TOWARD THE COAST WITH SW WIND ABT 10 MPH KEEPING TEMPS UP OVRNGT. FCST FOR MON AFTN/EVE LUKS ON TRACK WHERE MAIN PCPN THREAT LUKS TO BE DLMRVA...WRN BAY AREAS...AND PSBLY AS FAR S AS HAMPTON ROADS. CWF...NO CHGS. SW WNDS ABT 15 KTS CONT WITH 2-3 FT SEAS. .AKQ...NONE. HESS va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 1125 AM CDT MON JUN 12 2000 SCATTERED SHOWERS OCCURRING IN WESTERN CWA FROM PVA AS SHORTWAVE HEADS NORTHEAST. RUC SEEMED TO HANDLE THIS BEST. MORE MID-HIGH CLOUDS THAN ORIGINALLY EXPECTED DUE TO THIS FEATURE AND WITH ISENTROPIC LIFT. DROPPED TEMPS A TAD DUE TO THIS AND COOL EASTERLY FLOW. WILL ALSO HELP KEEP AIRMASS STABLE LONGER IN WESTERN SECTIONS. KEPT THE SLIGHT CHANCE OF THUNDERSTORMS IN SOUTHWEST SECTION...BUT IT LOOKS LIKE THUNDERSTORM ACTIVITY WILL HOLD OFF UNTIL LATE TONIGHT... OR BETTER YET TOMORROW. OTHER PROBLEM IS CLOUD COVER ACROSS REST OF CWA. HIGHER CLOUDS SLOWING THE BURN OFF OF LOW CLOUDS AND FOG ACROSS WESTERN TIP OF LAKE AND DOWN ALONG MN/WI BORDER. BECOMING PARTLY SUNNY HERE. .DLH...NONE. TAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1045 AM CDT MON JUN 12 2000 PERSISTENT CLOUDINESS IS OVER EASTERN MINNESOTA WITH ERLY FLOW. LATEST RUC/MESOETA MODELS SHOW MORE MOISTURE ADVECTION FROM THE SOUTHEAST...SO SOME CLOUDINESS MAY PERSIST WELL INTO THE AFTERNOON. OVER THE WEST...TREND CONTINUES TO BE FOR DESTABILIZATION WITH THE RISK OF SCATTERED THUNDERSTORMS THIS AFTERNOON. UPDATED FORECAST HAS MOVED THE THUNDERSTORM LINE FURTHER EAST...PER THE 12Z MESOETA MODEL AND STABLE ERLY FLOW. FORECAST HAS ALSO MENTIONED SEVERE THUNDERSTORM POTENTIAL AS ALONG FORECAST INSTABILITY AXIS AHEAD OF SHORT WAVE TROUGH TRACKING EWRD ACROSS IA/SRN MN THIS AFTERNOON. .MSP...NONE. SCOTT mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 310 AM CDT MON JUN 12 2000 THUNDERSTORM RELATED WEATHER REMAINS THE PRIMARY CONCERN THROUGH THE FORECAST...WITH TEMPS COMING SECOND. IN SHORT TERM...THE MODELS HAVE HAD A HARD TIME WITH LINE OF CONVECTION IN CNTRL NEB HEADING SLOWLY EAST WITH SOME NEWD ROTATION. THE SYSTEM HAS HELPED INTENSIFY A MID LEVEL SHORT WAVE CONSIDERABLY...AS SHOWN BY THE PROFILER NETWORK AND 06Z RUC. 06Z ETA RUN WILL BE CONSULTED FOR LAST MINUTE CHANGES...BUT EXPECT THAT THE NEARLY CLOSED MID LEVEL CIRC WILL ALLOW SOME CONVECTION TO PERSIST INTO THE MRNG AS IT CROSSES NORTHEAST NEB...BUT IT MAY FALL APART BEFORE REACHING SOUTHERN ZONES WHERE WAVE AND LOW LEVEL INFLOW BOTH APPEAR WEAKER. THIS THINKING COULD BE REVISED AS THE SYSTEM EVOLVES...AS FBY PROFILER WINDS ARE NOW INCRG AT 850 MB. AFTER THE CONVECTIVE REMNANTS PASS THROUGH THIS MORNING...A FAIRLY RAPID WARMUP SHOULD OCCUR WITH INCRG LOW LEVEL INFLOW FROM SSE AS THE HIGH PLAINS LOW INTENSIFIES TODAY. MODELS CONTINUE TO HINT AT A WEAK SFC TROUGH NEAR KS BORDER. BY LATE AFTN...ETA AND AVN MODEL SOUNDINGS SUGGEST THAT THERE WILL BE QUITE A BIT OF INSTABILITY WITH 850 LEVEL MOISTURE POOLING IN CWA AND NO 700 CAP. NEGATIVE FACTOR IS THE LACK OF A GOOD BOUNDARY FOR A TRIGGER EXCEPT THE SRN NEBRASKA TROUGH...BUT THERE COULD ALSO BE A LEFTOVER OUTFLOW BOUNDARY FURTHER NORTH. SITUATION SEEMS RIPE FOR SCT LATE AFTN AND EVE TSTMS ACROSS THE AREA...AND WILL RAISE POPS CENTRAL AND SOUTH. SUBTROPICAL MOIST PLUME EXPECTED TO REMAIN OVER THE AREA WILL ALSO ASSIST TSTM DEVELOPMENT...BUT MID LEVELS ARE DEPICTED AS DRYING SOMEWHAT SO ENTRAINMENT COULD LIMIT AREAL COVERAGE. SFC CONVECTIVE TEMP IN UPPER 80S TO AROUND 90 SHOULD BE REACHED. AVN AND NGM AGREE IN INCREASING WARM DRY SW LLJ DEVELOPING MONDAY NIGHT. THIS WILL CERTAINLY RESULT IN A WARM NIGHT AND MAY KILL OFF TSTMS AFTER DAYTIME HEATING IS DONE. HOWEVER...700 MB MOISTURE INCREASES TO IMPRESSIVE LEVELS ON AVN...WITH GOOD MOISTURE HIGHER UP IN BOTH MODELS. ELEVATED CONVECTION COULD DEVELOP ABOVE CAP. WHILE I EXPECT THE MAIN CHC TSTMS TO BE IN THE EVE...WILL NOT ATTEMPT TO RULE OUT OVERNIGHT. STRONG TSTM OUTBREAK IS LIKELY TUE AFTN AND EVENING AS A STRONG UPPER LEVEL TROUGH AND COLD FRONT SLAM INTO THE HOT UNSTABLE AIRMASS NEAR TIME OF MAX HEATING. AVN IS SLOWEST WITH FRONT WITH ETA JUST AHEAD AND SHOWING DECENT CONSISTENCY WITH PREVIOUS RUN. WILL TAKE THE ETA TIMING WHICH WOULD PUT THE FRONT THRU THE NORTHEAST SLIGHTLY BEFORE MAX HEATING. WILL RAISE POPS QUITE A BIT FURTHER SOUTH AS NGM MOS IS CLEARLY QUITE A BIT LOW ON POPS AND DAYTIME TEMPS. .OMA...NONE POLLACK ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 125 AM EDT MON JUN 12 2000 RUC SEEMS TO HAVE BEST IDEA ON FRONTAL PLACEMENT AND QPF IN THE SHORT RANGE. ETA MODELS SUGGEST THAT THE FRONT WANTS TO BE ABOUT A DEGREE OR TWO FURTHER SOUTH. VERY HUMID AIRMASS IS IN PLACE WITH PRECIP WATERS NOT FAR FROM 2"...OR 180+% OF NORMAL. WE HAVE A LOW LEVEL TRIGGER IN THE FORM OF THE Q-STNRY BOUNDARY... BUT HARD TO FIND COHERENT SUPPORT IN UPPER LEVELS. MODELS PROG A WEAK RIDGE AND WATER VAPOR DOESN'T THROW ANY LIGHT ON ANY SINGLE SHORTWAVE OF NOTE. VIS SAT SHOTS SHOW THAT CLOUDS ARE HANGING TOUGH OVER THE STATE WITH LIMITED SUNSHINE AT BEST. THIS SHUD HELP LIMIT INSTABILITY AND PROBABLY SEVERE POTENTIAL. IT LOOKS LIKE WE WILL STAY VULNERABLE TO RW/TRW FOR THE NEXT SVRL DAYS. WEAK BOUNDARY DOES SHOW SIGNS OF SAGGING SOUTHWARD AS HIGH BUILDS DOWN ACROSS NEW ENG COASTAL WATERS. MEANWHILE STRONG LOW IS PROGGED INTO UPPER PLAINS. THIS SHUD KEEP THE FRONT NEARBY... EVENTUALLY ALLOWING FOR IT TO RETURN TO OUR NORTH AS A WARM FRONT. MED RANGE GUID SHOWS RIDGE HANGING TOUGH ALONG EAST COAST. A COLD FRONT IS MADE TO WASH ABOUT THU-FRO BEFORE HAVING BIG IMPACT HERE...WITH SWLY FLOW REMAINING ESTABLISHED INTO THE WEEKEND. .CTP...NONE LA CORTE pa AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 300 PM CDT MON JUN 12 2000 PROBLEM OF THE DAY CONTINUES TO BE CHANCE AND INTENSITY OF CONVECTION ACROSS COUNTY WARNING AREA. CURRENT MODEL SOUNDINGS AND LAPS ANALYSIS SHOWING CAPE VALUES IN THE AREA IN THE 2500-3000 J/KG RANGE. LIFTED INDEX RUNNING AROUND -4 TO -6. SOME DEW POINT POOLING OBSERVED IN EASTERN SOUTH DAKOTA. TRIGGER IS MISSING AT THIS TIME. TWO CAPABLE BOUNDARIES EXIST BUT ONE IS TOO FAR NORTH AND THE OTHER TOO FAR WEST. ETA AND RUC MODEL SOUNDINGS AGREE WITH CONTINUING WARM ADVECTION IN THE MID LEVELS. 70H TEMPS GO FROM CURRENT READING AROUND 6C TO 10C BY 00Z. THIS WILL INHIBIT OUR CHANCES OF CONVECTION THIS AFTERNOON. TONIGHT AS THE UPPER TROUGH STRENGTHENS AND MOVES THROUGH SURFACE LOW MOVES ACROSS NORTHERN SOUTH DAKOTA. MODELS ARE SOMEWHAT AT ODDS ON STRENGTH AND TRACK OF LOW. WILL GO WITH BASICALLY AN ETA SOLUTION. ETA SEEMS TO HAVE BEST HANDLE ON CURRENT SITUATION. THIS IS PARTIALLY BASED ON JET POSITION AS ESTABLISHED WITH VISIBLE SATELLITE. THE EAT AND NCEP PROGS BRING COLD FRONT THROUGH EASTERN COUNTY WARNING AREA AROUND 12Z. WILL GO WITH LIKELY WORDING TONIGHT IN THE WEST DIMINISHING TO CHANCE TOMORROW WHILE THE EAST WILL GET CHANCE POPS TONIGHT AND LIKELY TOMORROW. WILL CONTINUE SEVERE WORDING BASED ON NCEP DAY1 GRAPHICS. ...EXTENDED DISCUSSION... MAJOR SHIFT IN THE WEATHER PATTERN THIS WEEK. 500MB RIDGE ACROSS THE CENTRAL UNITED STATES WILL BE REPLACED WITH A TROUGH. THIS SHIFT IN THE WEATHER PATTERN WILL BRING A COOL DOWN AND UNSETTLED CONDITIONS LATE THURSDAY INTO FRIDAY. THE MRF/ECMWF/NOGAPS/CANADIAN MODELS INDICATED SHORTWAVES ARE EXPECTED TO ROTATE AROUND THE HUDSON BAY TROUGH WHICH WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS LATE IN THE DAY THURSDAY AND INTO FRIDAY. THERE IS SOME CONCERN FOR PRECIPITATION CHANCES FOR SATURDAY...BUT WILL LEAVE IT DRY AT THIS TIME SINCE THE MODELS ARE UNCERTAIN AND PRECIP AMOUNTS ARE LIGHT. THE MRF/ECMWF/NOGAPS MODELS ARE INDICATING THAT FRIDAY MAY BE EXTREMELY COOL. BRINGING 850MB TEMPERATURES DOWN TO THE SURFACE USING THE SURFACE POTENTIAL TEMPERATURE FROM 850MB CHART WOULD SUPPORT HIGHS AROUND 60. WILL ONLY GO WITH HIGHS IN THE 60S AT THIS TIME BUT IT THERE IS SIGNIFICANT CLOUD COVER AND RAINFALL...TEMPERATURES MAY STRUGGLE TO GET OUT OF THE 50S. .ABR...NONE. KEEFE/ECKBERG N sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 400 AM CDT MON JUN 12 2000 LATEST ANALYSIS SHOWS A BOUNDARY LEFT OVER FROM LAST NIGHTS CONVECTION OVER THE SOUTH PLAINS APPROXIMATELY FROM TURKEY TO CROSBYTON TO LUBBOCK TO DENVER CITY TO PORTALES. LOWER THETA-E AIR LEFT OVER FROM THE OUTFLOW REMAINS TO THE NORTH OF THIS BOUNDARY. WOULD WATCH THIS BOUNDARY TO SEE IF IT WILL BE MORE PERSISTENT THAT CURRENT RUC FORECAST SHOWS. 06Z RUC SHOWS THIS BOUNDARY TO WASH OUT WITH DEWPOINTS RISING BACK INTO THE MID 60S OVER THE SOUTH PLAINS BY LATER THIS MORNING. LOW CLOUDS HAVE BEEN SLOW TO FORM BUT EXPECT STRATUS TO DEVELOP BEFORE DAYBREAK FOR MOST OF THE AREA. WILL PLAY THE SURFACE BOUNDARY/DRYLINE TO BE LOCATED NORTH-NORTHEAST TO SOUTH-SOUTHWEST NEAR A LINE FROM GUYMON TO WINK AS THE FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON. MODELS WERE VERY POOR WITH FORECASTING THE AMOUNT OF INSTABILITY REALIZED OVER THE REGION. ANOTHER ROUND OF SEVERE STORMS WILL BE POSSIBLE TODAY WITH HIGH WINDS THE MAIN THREAT WITH THE STRONGLY UNSTABLE AIRMASS AND WEAK MID LEVEL WIND FIELD. VERY HEAVY RAIN WILL AGAIN BE POSSIBLE BUT AM NOT CONFIDENT ENOUGH OF THE THREAT AREA TO POST ANY KIND OF FLOOD WATCHES ATTM. WILL CONTINUE CHANCE POPS FOR MOST AREAS TODAY AND TONIGHT. UPPER LEVEL JET STREAK SHOULD REMAIN JUST TO THE NORTH OF THE FORECAST AREA WITH UPPER LEVEL DIVERGENCE IN RIGHT ENTRANCE REGION OF THE JET PROVIDING SUPPORT FOR THUNDERSTORM ACTIVITY AS IT DID YESTERDAY. MODELS HAVE HAD A DIFFICULT TIME PICKING OUT THESE MID/UPPER LEVEL SHORT WAVE TROUGHS MOVING IN THE SOUTHWEST FLOW ALOFT. DO NOT EXPECT OTHERWISE AFTER THE EXPERIENCE OF THE LAST FEW DAYS. FOR TUESDAY...MID/UPPER LEVEL TROUGH DIGS SOUTHEAST INTO THE CENTRAL PLAINS BY TUESDAY AFTERNOON. COLD FRONT WILL BE MOVING INTO THE OKLAHOMA AND NORTHWEST TEXAS PANHANDLE BY LATE AFTERNOON WITH A SURFACE LOW NEAR GUYMON. DRYLINE AGAIN WILL BE IN THE SAME GENERAL AREA. WILL CONTINUE CHANCE POPS FOR SCATTERED THUNDERSTORMS TO DEVELOP ALONG THE DRYLINE. COLD FRONT SHOULD CATCH UP WITH THE DRYLINE TUESDAY NIGHT WITH INCREASED CONVERGENCE ALONG THE BOUNDARY. WILL BUMP THE POPS TO 40 PERCENT FOR THE AREA TUESDAY NIGHT. NO CHANGES TO THE EXTENDED. FRIONA 87/63/91/63 2323 TULIA 88/64/90/63 3434 CHILDRESS 88/71/92/69 2234 LUBBOCK 86/67/90/65 3434 BROWNFIELD 87/65/91/64 3434 ASPERMONT 87/72/90/70 3224 .LBB...NONE. TINSLEY tx