SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 903 AM MST SAT APR 8 2000 SYNOPSIS...STRONG HIGH PRESSURE OVER WEST TEXAS HAS PUSHED GUSTY WINDS AND BLOWING BUST INTO SOUTHEAST ARIZONA. THE WIND AND DUST WILL DIMINISH THIS EVENING...BUT A PACIFIC STORM SYSTEM MOVING INTO NORTHERN CALIFORNIA WILL CAUSE WINDS TO PICK UP AGAIN ON SUNDAY AND KEEP PATCHY HIGH CLOUDS OVER THE AREA. TEMPERATURES WILL REMAIN ABOUT 10 DEGREES ABOVE NORMAL FOR MUCH OF THE UPCOMING WEEK AS WEAK UPPER LEVEL HIGH PRESSURE REDEVELOPS OVER THE DESERT SOUTHWEST. DISCUSSION...HAVING PROBLEMS WITH WIDESPREAD BLOWING DUST WHICH HAS APPARENTLY BLOWN IN FROM WEST TX/S NM AND IS TRAPPED BELOW THE SUBSIDENCE INVERSION AT AROUND 8KFT. THE DUST ISN'T VERY DENSE BUT IT IS WIDESPREAD AND RESTRICTING VISIBILITIES TO MVFR (3-5MI). IT LOOKS PRETTY GROSS OUTSIDE OUR WINDOW AT THE MOMENT WITH VISIBILITIES 6 MILES AND FALLING. WE'LL KEEP A CLOSE EYE ON WINDS AS MM5 AND 12Z RUC SHOW THEM PEAKING BETWEEN 15-18Z AT 25KTS AND THEN HOLDING AT 15-25KTS UNTIL LATE AFTERNOON. BASED ON THAT, IF WE DON'T SEE THINGS COME UP FURTHER IN THE NEXT HOUR OR 2, WE'LL MOST LIKELY STAY BELOW ADVISORY CRITERIA. AS EXPECTED YESTERDAY, DEWPOINTS ARE COMING UP BEHIND THE BACKDOOR COLD FRONT, SO EVEN IF THE WINDS DO COME UP WE SHOULD STAY OUT OF RED FLAG LEVELS. BASED ON SLUGGISH TEMP RISES AND PENETRATION OF THE MODIFIED CANADIAN AIRMASS INTO THE E CWA, WE'LL LOWER HIGHS THERE A NOTCH. REST OF THE FORECAST IS IN FINE SHAPE WITH SE GRADIENT ENDING TONIGHT, ONLY TO TIGHTEN UP FROM THE SW TOMORROW. PYTLAK .TWC...NONE. az AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1035 PM EDT SAT APR 8 2000 THINGS STILL VERY QUIET ACROSS FORECAST AREA LATE THIS EVENING. SHORT WAVE RIDGING IS CURRENTLY SLIDING EAST INTO THE REGION...WITH THE APPROACHING CLIPPER SYSTEM CENTERED NEAR INTERNATIONAL FALLS MINNESOTA. MAIN CONCERNS FOR OVERNIGHT ARE HOW QUICKLY THE CLOUDS WITH THE CLIPPER WILL MOVE IN...THE RESULTANT EFFECT ON LOW TEMPERATURES AND IF IT WILL START SNOWING BY MORNING. 00Z APX SOUNDING IS DRY THROUGH THE COLUMN...WHICH IS NOT SURPRISING GIVEN THE CLEAR SKIES OVERHEAD. SATELLITE IMAGERY SHOWS CLOUDS WITH CLIPPER SYSTEM HAVING A HARD TIME MAKING A RAPID EASTWARD PROGRESS AS THEY RUN INTO THE DEFORMATION RIDGE. THE 00Z RUC ALSO SUPPORTS A SLOWER INCREASE IN MOISTURE/CLOUD COVER OVERNIGHT...WITH THE DEEPEST MOISTURE REMAINING IN THE IMMEDIATE VICINITY OF THE CLIPPER. ISENTROPIC PROGS...ON 285K SFC...IN ADVANCE OF THE CLIPPER SHOW ATMOSPHERE LIKELY REMAINING TOO DRY TO SNOW UNTIL NEARLY 12Z ACROSS NORTHWEST LOWER AND EASTERN UPPER. HAVE BACKED OFF ON CLOUD COVER AND POPS OVERNIGHT IN THIS AREA AS A RESULT. THE SLOWER INCREASE IN CLOUD COVER AND LIGHT WINDS MAKES ME CONCERNED THAT TEMPERATURES COULD FALL QUITE LOW TONIGHT GIVEN CURRENT DEW POINTS. HOWEVER... TEMPERATURES HAVE STAYED UP NICELY TO THIS POINT AND PREVIOUS FORECAST STILL LOOKS REASONABLE. .APX...NONE. BAK mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1020 PM EDT SAT APR 8 2000 TIMING OF CLOUDS AND PRECIP AND PRECIP AMOUNTS ARE CONCERNS FOR THE UPDATE. 00Z RAOBS/WATER VAPOR LOOP SHOW LONGWAVE UPPER LEVEL TROUGH OVER THE EASTERN CONUS...WITH A VORT MAX OVER NORTHWEST MINNESOTA HEADING TOWARD THE UPPER PENINSULA IN THE NORTHWEST FLOW. SURFACE ANALYSIS PLACES LOW PRESSURE ALONG THE MINNESOTA/CANADA BORDER...WITH A TROUGH EXTENDING SSE THROUGH WESTERN MINNESOTA. REGIONAL RADARS/METARS SHOW RAIN AHEAD OF THE SYSTEM...WITH SNOW MIXING IN ACROSS NORTHERN MINNESOTA. 00Z GRB/APX SOUNDINGS SHOW DRY AIR IN PLACE AHEAD OF THE SYSTEM. INITIAL LIFT WILL GO TOWARD SATURATION...AS APPARENT WITH ECHOS ALOFT OVER THE MINNESOTA ARROWHEAD AND NORTHERN WISCONSIN WITH SURFACE STATIONS REPORTING NO PRECIP. AS THE SYSTEM MOVES EAST...00Z RUC BRINGS AN AREA OF 850-500MB QVECTOR CONVERGENCE THROUGH THE REGION...COINCIDENT WITH AN A NEARLY SATURATED 850-500MB LAYER. ISENTROPIC LIFT ALSO EVIDENT ON 285K SURFACE WITH CONDENSATION PRESSURE DEFICITS BELOW 10MB AND SPECIFIC HUMIDITIES BETWEEN 1-2G/KG. 21Z/00Z RUCS KEEP ANY QPF CLOSELY TIED TO THE SURFACE SYSTEM...WHICH BRUSHES NORTHERN LAKE SUPERIOR AS IT MOVES EAST. HOWEVER BASED ON RADARS/METARS...PRECIP AREA IS BEST DELINEATED BY 850-500MB QVECTOR CONVERGENCE AT OR ABOVE 20 UNITS. BASED ON THIS TIMING...PRECIP WILL START IN THE WESTERN CWA BY MIDNIGHT...IN THE CENTRAL CWA AFTER MIDNIGHT...AND IN THE EASTERN CWA TOWARD MORNING. BASED ON UPSTREAM PRECIP AMOUNTS...EXPECT LESS THAN A TENTH OF AN INCH WITH THE SYSTEM. THE HEAVIEST AMOUNTS SHOULD FALL ACROSS THE NORTHERN CWA...WHERE MORE MOISTURE IS AVAILABLE. STATIONS ACROSS MINNESOTA HAD BEEN REPORTING RAIN THIS EVENING... BUT HAVE BEEN CHANGING OVER TO SNOW. WITH SURFACE TEMPERATURES NEAR OR BELOW FREEZING ALREADY...EXPECT PRECIP TO HAVE CHANGED TO ALL SNOW BY THE TIME IT BEGINS OVER THE CWA. .MQT...GALE WARNING LAKE SUPERIOR. JHB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1052 AM EDT SAT APR 8 2000 CURRENT SFC ANALYSIS SHOWS LOW ACROSS WRN NY/PA...WITH SATELLITE IR LOOPS SHOWING BACK EDGE OF COLD CONVEYOR BELT ENHANCED/HIGHER CLOUD TOPS PROGRESSING RATHER QUICKLY TO THE EAST THROUGH NC/NE LOWER MI. WILL UPDATE THE ERN UPR/NRN LWR MI FORECAST TO WORD MOSTLY SUNNY CONDITIONS. BEHIND UPPER TROUGH AXIS...STRONG NDVA/UPPER CONVERGENCE AND Q-VECTOR DIVERGENCE IS NOTED AS THE FLOW AT ALL LEVELS BECOMES MORE ANTI-CYCLONIC. ONLY CONCERN WAS WITH POTENTIAL FOR DIURNAL STRATOCUMULUS. HOWEVER...WITH THE SUBSIDENCE AND DEGREE OF DRY AIR MIXING THROUGH THE LOWER LEVELS ON BRISK NORTHERLY WINDS...BELIEVE EVEN SCATTERED DIURNAL CLOUDS WILL BE TOUGH TO COME BY. 12Z RUC SOUNDINGS DEPICT THIS RATHER WELL...WITH...DESPITE DECENT SFC-850 MB INSTABILITY BY LATE IN THE DAY...LOW-LEVEL PARCELS TOO DRY FOR MOIST CONVECTION. UPDATED ERN UPR/NRN LWR MI ZONE FORECAST TO FOLLOW AROUND 11 AM. .APX...NONE. HURLEY mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 920 PM CDT SAT APR 8 2000 FORECAST HAS BEEN UPDATED TO REFLECT PASSAGE OF FRONT IN W CENTRAL AND FOR WORDING IN W CENTRAL WI. SHORT WAVE TROUGH HAD MOVED INTO NW MN WITH LIFT MOVING TO ERN MN/WRN WI. FURTHER UPDATES ARE EXPECTED AS FRONT AND SHOWER ACTIVITY TRANSLATES EAST AND WINDS SHIFT. LATEST RUC MODEL WEAKENS SURFACE GRADIENT BUT THERE IS A FAIRLY STRONG ISALLOBARIC GRADIENT...ESPECIALLY TO THE NORTH. ON THE WHOLE...WINDS SHOULD DIE DOWN OVERNIGHT. .MSP...NONE. SCOTT mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1005 AM EST SAT APR 8 2000 DISC...FRONT AT 13Z WAS NEAR A EKN TO ATL LINE AND HAS SHOWN A QUICK PROGRESSION EASTERN OVER THE PAST 6 HOURS. THIS MOTION IS IN RESPONSE TO THE UPPER LEVEL JET OF 130 KTS MOVING ALONG A LIT TO BHM TRAJECTORY. LINEAR EXTRAPOLATION OF THE FRONT'S MOTION SHOWS THE FRONT REACHING OUR COAST BETWEEN 22 AND 00Z. THE EXTRAPOLATION AGREES CLOSELY WITH THE 06Z ETA. AS MENTION BY PREVIOUS SHIFT AND SPC MOISTURE IS INDEED THE KEY INGREDIENT THAT APPEARS TO BE LACKING WITH THIS SYSTEM. 13Z SURFACE ANALYSIS SHOWS TWO AREAS OF RELATIVELY HIGHER DEWPOINTS. THE FIRST IS SKIRTING THE CAROLINA COAST AND THE SECOND IS JUST ALONG AND AHEAD OF THE FRONT. THE MOISTURE ALONG THE COAST APPEARS THAT IT WILL NOT BE A FACTOR FOR OUR CWA AS SW FLOW WILL KEEP IT SHUNTED TO THE NORTH AND EAST. MODIFIED SOUNDINGS SHOWING CAPE UP TO AROUND 1000 J/KG AND WIND PROFILES SHOW A SPEED SHEAR PROFILE WHICH WILL BE CONDUCIVE TO DAMAGING WINDS. ALSO...WET-BULB ZEROS ARE RATHER LOW RANGING BETWEEN 6000-7000 SO IF DEEP CONVECTION COULD GET STARTED HAIL MAY ALSO BE IN THE MIX. WITH ALL THESE INGREDIENTS AND CURRENT TRENDS CONVECTION APPEARS TO BE LIMITED ALONG THE FRONTAL BOUNDARY SO IF ANY PROBLEMS DEVELOP FOR CWA WOULD EXPECT THEM DURING THE LATE AFTERNOON AND EARLY EVENING. CWF...CURRENTLY WINDS AT FPSN7 AND 41004 ARE RUNNING AROUND 15 KNOTS AND SEAS ARE 4 FEET. MODELS STILL ARE TO QUICK ON THE INCREASE OF WINDS. WITH FRONT PROGGED TO MAKE IT TO THE COAST THIS EVENING AND PRESSURE GRADIENT TO TIGHTEN WILL CONTINUE WITH THE GALE. 12Z RUC INDICATING THAT SOUTHERN WATERS MAY BE JUST BELOW GALE CRITERIA BUT WITH FAST MOVING FRONT WILL MAINTAIN THE GALE FOR THIS PACKAGE. .ILM...GALE WARING AMZ250-252-254-256. HAWKINS nc EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OK 750 PM CDT SAT APR 8 2000 WATCHING TEMPERATURE AND WIND TRENDS VERY CAREFULLY THIS EVENING. SAW LOTS OF GARDENING GOING ON IN THE SUBURBS ON THE WAY TO WORK THIS AFTERNOON...WOULDNT WANT TO GIVE THEM THE WRONG IMPRESSION. THERE IS A *CHANCE* THAT FROST OR EVEN A BRIEF FREEZE COULD OCCUR IN EASTERN OKLAHOMA...ALTHOUGH ODDS ARE IT WONT. WITH CLEAR SKIES...DRY AIR AND LIGHT WINDS...AND EXPECTED INCREASE IN WINDS IN NE OK AFTER MIDNIGHT...AGREE WITH WSW ISSUED EARLIER. HOWEVER...IF TEMPS DROP OFF AS EXPECTED AND MESO-ETA AND AVN MSL PRESSURE PROGS VERIFY...MAY BE EXPANDING THE WSW INTO SOUTHEAST OKLAHOMA AND WESTCENTRAL ARKANSAS. FOR NOW...WILL BE ISSUING QUICK UPDATE TO ADD MENTION OF PATCHY FROST AND INCREASE RANGE OF MIN TEMPS SLIGHTLY IN SEVERAL ZONES. WINDS IN NE OK ARE LIGHT WEST TO SOUTHWEST BUT AFTER SUNSET MAY GO TO LIGHT AND VARIABLE FOR SOME TIME. AM WORRIED THAT FWC GUIDANCE IS COUNTING ON STRONG LEE CYCLOGENESIS THIS EVENING AND WINDS PICKING UP AFTER MIDNIGHT. ETA ...MESO-ETA AND AVN ARE WEAKER WITH PRESSURE GRADIENT HOWEVER RUC HAS ABOUT THE SAME OR STRONGER STRENGTH PRES GRAD THAN NGM. MAY BE ISSUING ANOTHER AFD AND UPDATE BY 930PM. FCSTID = 26 .TUL... AR...FREEZE WARNING FOR SATURDAY NIGHT FOR ZONES ARZ001>002 ...ARZ010>011. OK...FREEZE WARNING FOR SATURDAY NIGHT FOR ZONE OKZ069. ok AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 900 PM CDT SAT APR 8 2000 LATEST MSAS ANLYS SHOWS COLD FRONT THROUGH ALL BUT FAR ERN COUNTIES. RUC AND LAMP SHOW THAT FRONT SHOULD SWING THROUGH BY 06Z...BUT WITHOUT THE GUSTY WINDS ASSOCIATED EARLIER TODAY WITH THE FRONT. DIURNAL CU ASSOCIATED WITH FRONT HAS ALSO DISSIPATED AND IS NO LONGER A CONCERN. WILL UPDATE FORECAST TO NEATEN UP WINDS. TEMPS LOOK OK AND WILL LEAVE ALONE. UPDATES OUT SHORTLY. .ABR...NONE. HINTZ sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1047 AM EDT SAT APR 8 2000 STORM SYS TO MOVE NE ACRS NY STATE TODAY AND THEN ACRS NEW ENG TONITE. COLDER AIR TO MOVE INTO THE REGION (MOSTLY ACRS NORTHERN NY) ON THE BACK SIDE OF THIS SYS TONITE. UPR TROF TO CONTINUE TO DIG ACRS THE GREAT LKS REGION TODAY AND EVENTUALLY BECOME NEGATIVELY TILTED TONITE. 09Z RUC SHOWS SOUTHERLY SFC FLOW ACRS MUCH OF THE FA TODAY (EXPECT ACRS THE ST LAW VLY) WITH AFTERNOON MAX TEMPS RANGING FROM AROUND 50 IN THE ST LAW VLY TO THE L-M60S IN VT. SEEMS A BIT ON THE HIGH SIDE IN THE ST LAW VLY GIVEN CURRENT TRENDS THERE. BEST MOISTURE (AND SFC MOIST FLUX CONV) TO BE LOCATED ACRS NY STATE TODAY. RUC INDICATING MAX CAPE VALUES OF 200 TO 700 J/KG ACRS NY STATE THIS AFTERNOON (VT TO REMAIN CAPPED TODAY). WINDEX (THAT/S THE SUMMERTIME WINDEX) VALUES ARE 20-35 KTS AND MUCH OF FA WILL BE IN A SFC-H7 SHEAR AREA OF >20 KTS TODAY. ALL ABOVE SPELLS BEST CHC FOR MEASURABLE PCPN TODAY WILL BE IN THE ST LAW VLY (FURTHEREST WEST PART OF FA). RISK FOR ANY MEASURABLE PCPN WILL DEPEND MORE ON SHRA/TSRA DEVELOPMENT THE FURTHER EAST ACRS THE FA THAT YOU GO. CURRENTLY SNOWING AT YOW ATTM...BUT RUC KEEPS COLD AIR AT BAY IN CANADA TODAY...SO WON/T HAVE TO DEAL WITH THAT THREAT UNTIL LATER TONITE. GOOD H85 WAA ACRS THE FA TODAY TO BE REPLACED BY GOOD CAA TONITE. MORE MOISTURE TO SWEEP ACRS THE REGION FROM THE WEST TONITE WITH MAIN AXIS OF PCPN SHIFTING EAST ACRS THE FA. PW VALUES APPEAR TO BE AROUND AN INCH. WILL CONT FFA FOR TONITE AND SUNDAY. H85 TEMPS GO NEGATIVE FROM WEST TO EAST (MOSTLY ACRS NORTHERN NY) OVRNITE TONITE. RAIN TO SNOW LOOKS GOOD FOR THE NY SIDE OVRNITE TONITE. WILL LOOK AT THAT EVENT MORE CLOSELY FOR THE AFTERNOON FORECAST PACKAGE. MORNING VIS SAT PIX SHOW DOWNSLOPING OFF THE WHITE MTNS OCCURRING ACRS NORTHERN NH/NORTHERN CT VLY ATTM WITH GOOD WIND-FLOW ALONG WESTERN VT SCOURING OUT THE CLDS PRETTY WELL. GOOD SE SFC FLOW ACRS THE WESTERN SLOPES OF THE GREEN MTNS ATTM WITH GUSTY WINDS A LIKELIHOOD IN THE FAVORED SE-NW ORIENTATED VLYS. HAVE INDICATED THIS IN THE MORNING UPDATE PACKAGE. HAVE ALSO RE-SPLIT ZONES FROM WEST TO EAST (FROM THE CHAMP VLY EASTWARD) DUE TO ABOVE CHANGES IN WIND FORECAST AND EXPECTED CLD COVER DIFFERENCES THIS AFTERNOON. TWEAKED MAX TEMP FORECAST FOR TODAY BASED ON LATEST OBS TRENDS AND 11Z LAMP DATA. WORK ZONES GONE. FINAL ZFP IN A BIT. .BTV...FLOOD WATCH VTZ001>012-NYZ026>031-034-035 TONIGHT THROUGH SUNDAY. MURRAY vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 220 PM CDT SAT APR 8 2000 PATTERN CHARACTERIZED BY MDT-STG WNW UPPER FLOW AND OCCASIONAL SHRTWV TROFS MOVG IN FROM ERN PAC. STORM WHICH BROUGHT SNOW TO SRN WISC FRI WL STRENGTHEN BLOCKING PAT OVR WRN ATLANTIC NXT 48-72 HRS. SYS MOVG OVR SRN MANITOBA NICELY DEPICTED ON WV IMAGERY AND 18Z RUC. SHRTWV TROF WL QUICKLY MOV ACRS NRN AND CNTRL WI OVRNGT...BRINGING CLDS AND SCT LGT PCPN...MAINLY N...IN LEFT-FRONT EXIT REGION OF UPR LVL JET. 12Z SHORT-RANGE MODELS ALL SIMILAR ON MVMT OF THESE FEATURES. BHD DEPARTING SHRTWV...STG SUBSIDENCE/SIG ISENT DECENT TAKES OVER...WITH CLEARING SKIES. RELATIVELY FAVORABLE TRAJ AND INCR THERMAL INSTAB WL BRING LK SUPERIOR EFFECT SC AND SNSH- TO VILAS CO...ESP IN AFTN...BUT SUBSIDENCE IS STG. 12Z NGM MOS AND AVN GUID TEMPS LOOK REASONABLE FOR SUNDAY. TEMPS IN FAR N MAY ACTUALLY STEADY/FALL DURING AFTN IN CAA. CLEAR-PARTLY CLOUDY SKIES AND RELAXING P-GRAD SUNDAY NGT WL ALLOW TEMPS TO FALL 6-12 DEGS BLO NORMS. AVN GUID TEMPS FOR SUN NGT SEEM A BIT ON THE HIGH SIDE. MID-HIGH CLOUDS THEN STREAM IN ON MONDAY AS BAROCLINIC ZONE SETS UP ACRS MIDWEST AND UPR FLOW BACKS TO THE W. SHRTWV TROFS IN NRN AND SRN STREAM BEGIN MOVG TWD REGION. .GRB...NONE. JKL WWW.CRH.NOAA.GOV/GRB wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 403 AM EDT SUN APR 9 2000 SYNOPSIS...CLIPPER SYSTEM IS MOVING OUT THE BOUNDARY WATERS AREA AND INTO LAKE SUPERIOR. PRECIPITAION WITH THE SYSTEM IS LINED UP ON THE QUICKLY ADVANCING WARM FRONT MODELS ARE IN GOOD AGREEMENT THIS MORNING AGAIN. ETA HAS BACKED OFF ON ITS 850 COLD AIR PLUNGE MORE IN LINE WITH WHAT THE AVN WAS ADVERTISING LAST NIGHT. SO THE ONSET OF LAKE SNOW SHOWERS HAVE BEEN SLOWED DOWN SINCE YESTERDAY MORNNING'S PACKAGE. TODAY...00Z ETA/MESOETA RUN SHOW THAT THE TIMING OF THE SHOWERS IS STILL ON TRACK AND THAT IT SHOULD BE IN THE FORM OF SNOW ACROSS THE CWFA WITH 850 TEMPERATURES AT OR BELOW -6C AND 1000-850 THICKNESSES BELOW THE 1300M CRITICAL THICKNESS. THE MAIN CONCERN WITH THIS TIME PERIOD WILL BE THE CONVECTIVE NATURE OF THE SHOWERS. COULD THERE BE THUNDER? H5 TEMPERATURE OVER MOST OF THE CWFA IS -34C, 1000-850 LAPSE RATE IS 6 TO 6.5C/KM AND 850 TO 500 AND 700 TO 500 LAPSE RATES ARE BOTH 7+C/KM. THE ONLY THING IS AS THIS SYSTEM HAS BEEN MOVING CLOSER THE UPPER LEVEL (850-500) RH BEGINS TO WANE SO WONDER IF THE MOISTURE ISN'T DEEP ENOUGH TO SUPPORT THE THUNDER. SFC TEMPERATURES WILL START OUT FAIRLY COLD WITH MOSTLY CLEAR SKY OF LAST NIGHT. SO THE THOUGHT WILL BE TO KEEP THE THUNDER OUT AND KEEP THE CATEGORICAL POPS AND AMOUNTS IN HOWEVER, MAY TRIM THE AMOUNTS BACK A BIT DUE TO THE SPEED OF THE SYSTEM MOVING ACROSS THE REGION. FWCS SEEM A BETTER BET TODAY THAN THE WARMER FANS DUE TO 850 TEMPS ON THE NGM/ETA/RUC VS THE AVN. TONIGHT...LAKE CLOUDS WILL MOVE INTO EASTERN UPPER AND NORTHWEST LOWER AS THE 850 TEMPERATURES BEGIN TO FALL OFF AS THE CLIPPER MOVES TO THE EAST. INVERSION HEIGHTS FALL TO 4800 FEET BY 6Z ABOUT THE TIME THAT THE DELTA TS BEGIN TO BECOME FAVORABLE (>13C). THE MOISTURE IN NORTHWEST LOWER IS LIMITED AS THE DRY BEGINS TO MOVE IN, HOWEVER IS REMAINS ABOVE 50% BY 12Z IN EASTERN UPPER. WHILE WIND DIRECTIONS ARE FAVORABLE FOR LAKE EFFECT THE WIND SPEEDS WILL BE 25 TO 30 KNOTS WHICH WILL CUT DOWN ON THE RESIDENCE TIMES. THE LOCAL CHECKLIST FOR THIS COMES OUT WITH MINOR ACCUMULATIONS SINCE THE DELTA TS DON'T GET ABOVE 17C. SO THE GOING FORECAST OF TURNING OUT MOSTLY CLOUDY WITH A CHANCE OF SNOW SHOWERS IS FINE. FWC/FAN ARE IN THE LINE HERE WITH GOOD MIXING FROM THE WIND OVERNIGHT. MONDAY...LOW LEVEL MOISTURE REMAINS WITH MARGINAL DELTA TS (13-14C) IN EASTERN UPPER SO THE PARTLY SUNNY FORECAST LOOKS GOOD WITH CHANCE FOR SNOW SHOWERS. NORTHWEST LOWER IS IN MUCH DRIER AIR (<50% H8) SO WILL GO PARTLY OR MOSTLY SUNNY ACROSS THE AREA. WAA CLOUDS FROM THE SYSTEM GETTING ORGANIZED IN THE SOUTHERN PLAINS WILL BEGIN TO INVADE THE SOUTHERN PART OF THE CWFA BY LATE IN THE AFTERNOON. MONDAY NIGHT/TUESDAY...AVN LOOKS CONSISTENT WITH THE CURRENT FORECAST. IT COULD BE MOSTLY CLOUDY ON MONDAY NIGHT AS THE SOUTHERN SYSTEM JUST BRUSHES THE SOUTHERN PART OF THE CWFA. THE MAIN THREAT FOR PRECIPITATION WILL MOST LIKELY BE ON TUSEDAY NIGHT AS THE NEXT CLIPPER COMES OUT OF THE NORTHWEST. WILL LEAVE THIS AS IS. COORDINATED WITH MQT/GRR. .APX...NONE. LUTZ mi FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS 310 AM SUN APR 9 2000 FCST CHALLENGE...CLOUDS/TEMPS TODAY AND THEN CHC SNOW LATE TONIGHT THRU TUESDAY. WRKFGF OUT BY 345 AM. .CURRENT... SFC LOW MOVING EAST THRU SW ONTARIO...AREA OF SC AND A FEW SNOW SHOWERS ROTATING THROUGH NW MN (BDE AREA). AREA OF SC IN SRN MB MOVING SOUTH BUT ARE DISSIPATING SOME. OTHERWISE SKIES ARE GENERALLY CLEAR OVER ERN ND INTO WCNTRL MN. THIS CLEAR WEDGE IN CLOSE AGREEMENT TO RUC 700-500MB LAPSE RATE DISPLAY. MODELS IN GENERAL AGREEMENT THRU 48HRS...BUT FEEL ARE OVERDONE ON AMT OF QPF AS THEY HAVE BEEN RECENTLY WITH THESE UPPER SYSTEMS IN NW FLOW. WILL GENERALLY LEAN TOWARD ETA WITH 50H FEATURES...BUT ETA IS TOO COOL AND MOIST IN LOW LEVELS (85H AND BLO). .SHORT TERM... COOL 50H TEMPS SHOULD RESULT IN CU DEVELOPMENT MIDDAY AND AFTN. OTHERWISE...DO EXPECT SCT-BKN SC TO DRIFT SOUTHEAST FROM SRN MB INTO NW MN...AND SCT HIGH AND MID CLDS TO MOVE SOUTHEAST FROM SK INTO CWFA THIS AFTN AHEAD OF NEXT 50H WAVE. OVERALL...FEEL PTLY SUNNY WILL WORK FOR TODAYS SKY COVER. AS FOR TEMPS...WILL USE BLEND OF FWC/FAN. PREV ZFP HIGHS FOR SUNDAY LOOK GOOD...35-40 NE TO 40-45 SW CWFA. .LONGER TERM... 50H SHORT WAVE NOW SEEN ENTERING NW BC ON WATER VAPOR RATHER IMPRESSIVE. IT WILL DROP SOUTHEAST AND MOVE FROM NW INTO SE ND LATE TONIGHT INTO MONDAY. DO EXPECT SOME LIGHT SNOW WITH THIS FEATURE...AND PROBABLY A NARROW BAND OF ACCUMULATING SNOW. BUT LOCATION OF THIS BAND IS IN DOUBT AND WILL BE NARROW. WILL GENERALLY PUT LOW POPS TONIGHT FOR ERN ND AND PUT 30-50 POPS OVER ERN ND INTO WCNTRL MN ON MONDAY. CURRENT ZFP HAS NO POPS IN BDE ZONE AND WILL CONTINUE THIS TREND. 85H TEMPS REMAIN IN THE -6 TO -10 RANGE THRU 00Z TUESDAY. THUS EXPECT LITTLE OVERALL DAY TO DAY TEMP CHANGES. WILL CONTINUE TO USE FAN/FWC BLEND. .EXTENDED... NO CHANGES PLANNED. WILL PROBABLY SEE CHC -SHSN AGAIN ON TUESDAY...BUT WILL LET LATER SHIFTS ANALYZE THIS. 00Z GLOBAL CANADIAN SHOWS MORE MOISTURE IN THE THU TIME FRAME...BUT AGAIN CONFIDENCE IS TOO LOW TO CHANGE ANYTHING IN CURRENT EXTENDED WHICH MENTIONS CHC RA/SN WED AND FRI. .FGF...NONE. RIDDLE nd WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 125 PM MDT SUN APR 9 2000 MODELS AND WATER VAPOR INITIALIZED WEAK CLOSED LOW IN OREGON... OPENING QUICKLY THIS MORNING. WEAKLY-CYCLONIC 80KT JET JUST SOUTH OF LOW CENTER PRODUCED GOOD DIVERGENCE (IN LEFT EXIT QUAD) AND PRECIP OVER IDAHO...INITIALIZED TOO FAR SOUTH IN ALL BUT RUC. JET AND ASSOCIATED DIVERGENCE ARE WEAKENING AND WILL STAY NORTH OF THIS CWFA. NGM HAS AGAIN INITIALIZED SURFACE CLOSEST AND REMAINS SO AT 18Z. STRONG WINDS ARE NOT MATERIALIZING WITH INITIAL MIXING. 18Z KGJX-88D VAD WINDS SHOW 40KT AT 19K...ALREADY LESS AT KMTX. GRADIENT IS ALREADY SLACKENING EVEN AHEAD OF FRONT. FROPA FOR MOST OF CWFA BY EARLY EVENING. TONIGHT: RUC INDICATES MOST VALLEYS TO DECOUPLE WELL BEFORE MIDNIGHT ...THOUGH SOUTHERN VALLEYS COULD CONTINUE TO MIX LATER IN PROXIMITY OF FRONT. MIN TEMP GUIDANCE LOOK A CATEGORY TOO WARM BUT NO VALLEY FREEZE EXPECTED. WILL MENTION AN ISOLATED POP IN NORTHERN MTNS TONIGHT AND DROP THEM ELSEWHERE. MONDAY: SYSTEM SPLITS WITH NORTHERN MTNS REMAINING IN COOL NW FLOW. 12Z MODELS SHOW MORE ENERGY IN SOUTHERN PORTION...MOST IN THE AVN. TROF SAGS THRU CENTRAL ZONES BY AFTERNOON. MOISTURE IS PROGGED TO ORIGINATE OFF THE BAJA WHICH LOOKS UNIMPRESSIVE SO FAR. FOR NOW WILL MENTION A SKEPTICAL MTN ISOLATED POP...SLIGHT CHANCE SOUTH. 700 TEMPS ABOUT 4C COOLER BY AFTERNOON. TUESDAY: SOUTHERN ENERGY PROGRESSES INTO SOUTHERN NM. MEXICAN MOISTURE PROGGED TO PULL UP INTO THE SOUTHERN MTNS...SO WILL KEEP ISOLATED POPS THERE WITH LOW CONFIDENCE. EXTENDED: PATTERN SHOWS NO MAJOR CHANGE WITH WEST RIDGE AND OCCASIONAL CUTOFF LOW PASSAGE TO PRODUCE WINDS AND LITTLE PRECIP. WEAK RIDGING THRU THURSDAY. FRIDAY IS SW FLOW AHEAD OF NEXT PACIFIC SYSTEM IN THE MOST PROGRESSIVE SPECTRALS (CANADIAN...NOGAPS... LATEST MRF) BUT STILL RIDGING IN OLD MRF AND EC. EITHER SCENARIO WOULD BE DRY...GIVEN THE LAST TWO CUTOFF PASSAGES. SO A BENIGN DRY EXTENDED CONTINUES. RAMEY.99/NADLER.83 .GJT...NONE. co