AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 945 AM EST SAT MAR 3 2001 CRNT SAT TRENDS SHOWING THN ST/SC CLRG OUT ACRS NRNR CWA. SHOULD CONT TO SLOWLY PROGRESS AS HI 950-900MB MSTR MIXES...SPCLY WRN ZNS WHERE SAT SHWNG THNG ST. SERN ZNS HAVE THICKEST CLD LYR AND WL BE LAST TO MIX OUT. WL WORD MSNY OR BCMG MSNY...XCPT BCMG PSNY SERN ZNS. SOME INCRS IN LWLVL LAPSE RATES THIS AFTN FOR SOME REDEVELOPMENT...ETA 12Z RUN AND LTST RUC CU RULES SUGGESTS SVLR HOURS OF NOTHING MORE THAN SCT. .IWX...NONE. PBM in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 1015 PM CST SAT MAR 3 2001 LATEST SURFACE ANALYSIS DEPICTS DEEPENING SURFACE LOW PRESSURE OVER NORTHERN MISSISSIPPI. THIS IS MORE IN LINE WITH THE 12Z ETA RUN... COMPARED WITH THE AVN WHICH WAS TOO FAR EAST. THIS HAS NECESSITATED A BOOST IN POPS FOR OVERNIGHT AND SUNDAY OVER MOST OF THE AREA. WINDS WILL ALSO LIKELY BE A BIT STRONGER THAN PREVIOUSLY THOUGHT WITH THE PROXIMITY OF THE SURFACE LOW. THE BEST CHANCE FOR RAIN CONTINUES TO BE ALONG AND SOUTHEAST OF THE OHIO RIVER...WITH LESSER CHANCE ACROSS THE NORTHERN TIER FROM MOUNT VERNON ILLINOIS TO PRINCETON INDIANA...WHERE THE LOWER TROPOSPHERE IS HAVING A DIFFICULT TIME SATURATING. LATEST KPAH/KNQA 88D LOOPS INDICATE CONVECTIVE ACTIVITY HEADING NORTH OVER WESTERN TENNESSEE. THIS COMBINED WITH LATEST RUC/ETA SHOWALTER AND K INDICES MEANS THAT ELEVATED CONVECTION COULD OCCUR IN THE KENTUCKY COUNTIES BORDERING TENNESSEE OVERNIGHT. HAVE MADE APPROPRIATE CHANGES TO 1ST AND 2ND PERIODS...OTHERWISE REST OF FORECAST STILL ON TRACK. .PAH...NONE. RJP ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1058 PM EST SAT MAR 3 2001 KAPX 88D SHOWS WIDESPREAD SNOW SHOWERS ACROSS EASTERN UPPER AND SPREADING ACROSS THE TIP OF THE MITT COUNTIES...WITH SOME EMBEDDED 28+ DBZ RETURNS ACROSS THE STRAITS AREA. ALREADY A COUPLE OF INCHES REPORTED AROUND ENGADINE SINCE 7 PM. CLOUDS HAVE ALSO SPREAD INTO WEST CENTRAL LOWER COUNTIES...WITH FOG PUSHING IN OFF LAKE MICHIGAN AND INTO THE IMMEDIATE LAKESHORE AREAS FROM AROUND NORTHPORT ON SOUTH...SKIES ARE STILL CLEAR/PARTLY CLOUDY ACROSS EAST CENTRAL LOWER. 01Z SURFACE ANALYSIS SHOWED A FRONT WEAVING ITS WAY ACROSS NORTHERN MN/WI TO A WEAK WAVE NEAR GLR...THEN EAST ACROSS LAKE HURON. SHORT WAVE EVIDENT IN WV IMAGERY ACROSS UPPER MICHIGAN...WITH SOME DRYING/SUBSIDENCE ALREADY PUSHING ACROSS CENTRAL UPPER...CORRESPONDS WELL WITH BACK EDGE OF PRECIPITATION NOW MOVING OUT INTO LAKE MICHIGAN. 00Z APX SOUNDING HAD A DRY ADIABATIC LAYER FROM 925-740MB...SHORT WAVE INTERACTING WITH CONDITIONAL INSTABILITY RESULTING IN FLARE UP OF SNOW SHOWERS ACROSS NORTHERN SECTIONS OF THE FORECAST AREA THIS EVENING. MAIN PROBLEM TONIGHT CONCERNS SNOWFALL AND LOW TEMPERATURES...WITH MANY AREAS ACROSS NORTHERN LOWER AOB 30F. EASTERN UPPER...GIVEN SLIGHTLY COLDER 700MB TEMPERATURES ACROSS UPPER MICHIGAN...SUSPECT THAT THE INSTABILITY IS GREATEST IN THIS AREA WITH RUC MODEL SOUNDING INVERSION HEIGHTS AROUND 700MB. AFOREMENTIONED SHORT WAVE WILL CROSS EASTERN UPPER DURING THE EARLY PREDAWN HOURS...THUS EXPECT SNOW SHOWERS TO WIND DOWN FROM WEST TO EAST BETWEEN 05Z-07Z...FOLLOWED BY SUBSIDENCE AND DRYING. ADDED ANOTHER 1-2 INCHES OF ACCUMULATIONS...ALTHOUGH MUCH OF IT WILL BE EAST OF I-75. LOW LEVEL NORTHEAST WIND OVERNIGHT WILL KEEP ANY LAKE EFFECT CLOUDS/SNOW SHOWERS OUT OF CHIPPEWA/MACKINAC COUNTIES...AND PROGGED DRYING COMBINED WITH DOWNSLOPING WIND COMPONENT STILL SUPPORTS SOME CLEARING OVERNIGHT. IR SATELLITE TRENDS SUPPORT THIS AS WELL WITH CLEARING NOW PUSHING TOWARD THE ST MARY'S RIVER. SINGLE DIGIT LOWS STILL A POSSIBILITY HERE...SO NO CHANGES TO TEMPERATURE FORECAST. NORTHERN LOWER...MORE COMPLICATED HERE AS DEPTH OF CONDITIONALLY UNSTABLE LAYER SHRINKS FROM NORTH TO SOUTH. 00Z GRB SOUNDING MUCH DRIER THAN APX...WITH NEARLY DRY ADIABATIC LAYER ONLY UP TO 790MB. BELIEVE CURRENT RADAR TRENDS SUPPORT IDEA THAT WITH GREATEST INSTABILITY LIKELY BEING NORTH OF M-72...BEST CHANCES FOR SNOW SHOWERS WILL EXIST THERE. WENT WITH 1-2 INCHES ACROSS TIP OF THE MITT COUNTIES...AND AROUND AN INCH ALONG M-32 CORRIDOR. SIMILAR TO EASTERN UPPER...EXPECT SNOW SHOWERS TO TAPER OFF FROM WEST TO EAST AS SHORT WAVE PASSES BY...ROUGHLY BETWEEN 06Z-09Z. FARTHER SOUTH...AS LOW LEVEL WINDS VEER NORTHWEST CLOUDS WILL OVERSPREAD AREAS THAT ARE CURRENTLY CLEAR/PARTLY CLOUDY...PERSISTENT LOW LEVEL CONVERGENCE ALONG SURFACE/ 925MB TROUGH MAY BE ENOUGH TO PRODUCE SOME FLURRIES ACROSS EAST CENTRAL LOWER. AS FOR LOW TEMPERATURES...WITHOUT A SIGNIFICANT INCREASE IN WIND SPEED OVERNIGHT COLDER AIR WILL HAVE A HARD TIME MAKING INROADS INTO NORTHERN LOWER...BEST THREAT FOR LOWS IN THE TEENS TONIGHT APPEAR TO BE ACROSS FAR NORTHERN LOWER...BUMPED MOST OTHER AREAS INTO THE 20S OVERNIGHT. UPDATED ARBZFPAPX ALREADY ISSUED. .APX...NONE. JPB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1115 AM EST SAT MAR 3 2001 UPDATE CONCERN IS WITH SNOW/TEMPERATURES ALONG APPROACHING FRONT. 12Z RAOBS/WATER VAPOR LOOP SHOW VORT MAX JUST REACHING NORTHERN LAKE SUPERIOR...ROTATING AROUND UPPER LOW OVER THE NORTHEAST. SURFACE ANALYSIS/METARS SHOW THE COLD FRONT HAS PASSED THROUGH THE LAKE SUPERIOR C-MAN STATIONS AND THE KEWEENAW PENINSULA...AND IS LOCATED BETWEEN KCMX AND KMQT. KMQT RADAR SHOWS LIGHT SNOW ALONG/BEHIND THE FRONT. UPPER SHORTWAVE WILL CONTINUE SWINGING SOUTHEAST ACROSS THE CWA... PUSHING THE FRONT THROUGH THIS AFTERNOON. MOISTURE IS MODEST ACROSS THE NORTH AND EAST WITH THIS SYSTEM...1000-500MB RH AROUND 70 PERCENT AND SOUNDINGS SOMEWHAT MOIST BELOW 700MB. THE SOUTHWEST IS DRIER AWAY FROM THE BETTER FORCING AND LAKE MODIFICATION. 850MB TEMPS FALL TO -13C ACROSS THE NORTHWEST PER 12Z RUC/ETA BY 00Z THIS EVENING. COLD AIR MARGINAL FOR LAKE EFFECT BUT WITH ENHANCEMENT WILL CONTINUE CATEGORICAL WORDING FOR PRECIP. WITH LIMITED NATURE OF SNOW AND LACK OF STRONG MOISTURE WILL WORD LIGHT SNOW SHOWERS. CURRENT TEMPERATURES RANGE FROM 28 ALONG LAKE SUPERIOR TO 37 INLAND ACROSS THE SOUTH. AS COLD ADVECTION CONTINUES BEHIND THE FRONT...EXPECT TEMPERATURES TO SLOWLY FALL THROUGH THE AFTERNOON ACROSS THE NORTH. WITH MORE SUN TO BEGIN WITH AND COLD ADVECTION BEHIND THE FRONT LATER THIS AFTERNOON ACROSS THE SOUTH...WILL MENTION HIGH AND THEN FALLING TEMPERATURES. WINDS INCREASE OUT OF THE NORTHEAST BEHIND THE FRONT PER MODEL GUIDANCE/OBSERVED WINDS UPSTREAM AND WILL CONTINUE MENTION OF BRISK/BECOMING BRISK ALONG THE NORTHERN COUNTIES. .MQT...NONE. JHB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1110 AM EST SAT MAR 3 2001 MQT AND APX 88DS WERE SHOWING SCATTERED LIGHT SNOW SHOWERS AFFECTING PORTIONS OF EASTERN AND CENTRAL UPPER MICHIGAN AND THE STRAITS REGION. VISIBLE SATELLITE AND SURFACE OBSERVATIONS CURRENTLY SHOW CLOUDY SKIES OVER EAST UPPER AND EXTREME NORTHERN LOWER MICHIGAN... WITH PARTLY TO MOSTLY SUNNY SKIES OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA. THE MAIN QUESTIONS THIS PACKAGE WERE FOCUSED ON AFTERNOON SNOWFALL AND CLOUDS. THE LATEST RUC SHOWS A 500 MB TROUGH AXIS SLIDING OVER LAKE SUPERIOR THIS AFTERNOON. AN AREA OF 700/500 MB QVECTOR CONVERGENCE IN ADVANCE OF THIS SYSTEM WILL CONTINUE TO AFFECT EAST UPPER AND THE STRAITS AREA THROUGH THE AFTERNOON...BEFORE SINKING SOUTHWARD INTO THE SOUTHERN PORTIONS OF THE FORECAST AREA BY THIS EVENING. RUC MODEL SOUNDINGS SHOW THE BEST MOISTURE TO REMAIN OVER THE NORTHERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON... WITH MOISTURE SLOWLY INCREASING OVER THE SOUTHERN PORTIONS THIS AFTERNOON. DUE TO CURRENT TEMPERATURES AND SUN SOUTH OF M-72... WILL BUMP UP AFTERNOON TEMPERATURES A TAD THERE. FOR THE REST OF THE FORECAST AREA... WILL GO WITH SCATTERED SNOW SHOWERS WITH ACCUMULATIONS UNDER AN INCH. WILL MENTION HIGHS IN THE MID TO UPPER 20S OVER EAST UPPER AND AROUND 30 TO THE LOWER 30 OVER EXTREME NORTHERN LOWER. .APX...NONE. SWR mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1028 AM CST SAT MAR 3 2001 UPDATED THE ZONES TO REMOVE THE DENSE FOG ADVISORY IN THE WEST. AFTERNOON HIGH TEMPERATURES LOOK PRETTY GOOD AND WENT WITH THE HIGHER END WHERE A TWO CATEGORY RANGE WAS GIVEN. BAND OF LOW CLOUDINESS ACROSS THE NORTH IS BACKING TO THE WEST AND SOUTH AROUND 10 KNOTS. LATEST RUC SHOWING INCREASING MOISTURE ACROSS THE NORTHERN CWA DURING THE AFTERNOON AND WILL CONTINUE WITH INCREASING CLOUDINESS IN THIS AREA. DP/DT ON THE 12Z AVN FOR 48 HOURS SHOWS THAT THE H5 LOW IS BEING FORECAST FURTHER WEST. 72 HOURS AGO IT WAS PROGGED OVER SOUTHERN LHUR AND NOW AT 48 HOURS IT IS PROGGED OVER SOUTHERN LMIC. THIS MEANS LOW LEVEL COLD AIR WILL PENETRATE FURTHER INTO THE CWA FOR A LONGER PERIOD. .MSP...NONE. HILTBRAND mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 1100 AM MST SAT MAR 3 2001 UPDATED AFTERNOON FORECASTS FOR MORE IN THE WAY OF CONVECTIVE PRECIPITATION. LATEST TIME SECTIONS FROM RUC2 AND MESOETA RUNS SHOW CONTINUED POTENTIAL FOR SHOWERS/THUNDERSTORMS TILL AROUND SUNSET... WITH LIGHTNING STRIKES ALREADY PRESENT IN NORTHWEST LINCOLN COUNTY. ALSO ADDED LAKE CAUTIONS TO THE WESTERN AND SOUTHERN ZONES. UPDATED FORECASTS OUT SHORTLY. 38 .ABQ...NONE. nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 313 PM EST SAT MAR 3 2001 NEARLY STATIONARY FRONT RIGHT ACROSS THE CAE CWA. IN THE MID 60S TO THE SOUTH AND MID 50S IN THE NORTH. LIGHTNING PLOT SHOWING THAT ACTIVITY DISSIPATES ONCE IT GETS INTO CENTRAL GEORGIA NEAR MACON. WEST OF THERE IS WHERE H8 RUC HAS BEST WAA. RUC BRINGS H8 WINDS MORE SOUTHERLY BY 03Z AND THERE SHOULD BE SOME THUNDERSTORMS OVERNIGHT PERIOD. MESOETA HAS BEST OMEGA 00Z TO 06Z THEN MOVES TO NORTH CAROLINA BY 09Z. SO WILL MENTION RAIN HEAVY AT TIMES TONIGHT. TO THE NORTH OF THE WARM FRONT LATE TONIGHT THERE COULD BE SOME FOG NORTH PORTION OF CAE CWA. ETA BUFKIT SHOWS DEEPEST MOISTURE OVERNIGHT. ATMOSPHERE BECOMES MORE UNSTABLE SUNDAY MORNING WITH LIS -1 BUT K INDEX DROPS BELOW 20 BY 15Z. SO WILL MENTION SOME MORNING THUNDERSTORM ALONG WITH A LIKELY CHANCE OF SHOWERS. BUT WITH DRIER AIR BY AFTERNOON WILL GO CHANCE OF SHOWERS. WRAP AROUND MOISTURE SHOULD KEEP A CHANCE OF SHOWERS EARLY SUNDAY NIGHT BUT WINDS BECOME MORE DOWNSLOPE AND WILL DROP SHOWERS BY MIDNIGHT. COLDER AIR ARRIVES FOR EXTENDED PERIOD WITH SOME MOISTURE PROBABLY MAKING IT ACROSS THE MOUNTAINS BUT LOW LAYERS SHOULD BE DRY WITH DOWNSLOPE CONDITIONS. IN ADDITION INCREASING WINDS SHOULD ADDITIONALLY DRY LOW LAYERS. WILL BE GENERALLY CLOSE TO GUIDANCE TEMPERATURES BUT WILL CUT HIGHS ESPECIALLY MONDAY THROUGH WEDNESDAY. FCSTID = 7 CAE 62 73 43 49 / 100 60 30 10 AGS 63 72 42 49 / 100 60 30 10 SSC 62 72 43 48 / 100 60 30 10 OGB 63 73 43 49 / 100 60 30 10 .CAE... GA...NONE. SC...NONE. TTH sc AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE NASHVILLE TN 1035 AM CST SAT MAR 3 2001 CURRENTLY...1002 MB SURFACE LOW IS LOCATED NEAR THE LA COAST...W/ INFRARED SATELLITE/LIGHTNING PLOT SHOWING MOST ACTIVE WEATHER ALONG THE GULF COAST. WARM FRONT EXTENDS FROM THE LOW...THROUGH CENTRAL MS...CENTRAL AL...AND INTO NORTHERN GA. LOCALLY... EARLIER SHOWERS OVER THE SOUTHERN PLATEAU HAVE MOVED EAST...ALTHOUGH 16Z SURFACE PLOT SHOWS LIGHT RAIN AT HSV AND TUP. DEW POINTS ACROSS THE MID STATE ARE MAINLY IN THE 40S. 12Z BNA SOUNDING DOES SHOW SIGNIFICANT MOISTENING OF THE COLUMN...W/ PRECIPITABLE WATER UP TO 0.73 INCHES...BUT W/ PRONOUNCED DRY LAYER BETWEEN 925 AND 700 MB. ALSO...STRONG SURFACE TO ~780 MB INVERSION WILL HAVE TO BE OVERCOME. 15Z RUC MODEL HOLDS DEEPEST MOISTURE SOUTH OF MIDDLE TN UNTIL BETWEEN 18Z AND 21Z...WHEN STRENGTHENING LOW LEVEL FLOW PUSHES THE MOISTURE OVER THE WARM FRONT. THIS SHOULD LEAD TO PRECIPITATION DEVELOPMENT DURING THE LATE AFTERNOON ACROSS MIDDLE TN. WILL AMEND THE ZONES SHORTLY TO UPDATE WORDING...ALTHOUGH WILL LEAVE THE ACTUAL FORECAST AS IS. .BNA...NONE. 08 tn AREA FORECAST DISCUSSION...CORRECTED WATCH AREAS NATIONAL WEATHER SERVICE WAKEFIELD, VA 1045 AM EST SAT MAR 3 2001 OVERRUNNING ALREADY ON GOING ACRS THE SRN PART OF THE AREA THIS MRNG. LOOKING AT RUC AND NEW MODELS THINK PRECIP WL CONTINUE ACRS NE NC THIS AFTN. RADARS TO THE SW STILL SHOW PLENTY OF LGT RN TO MOVE ACRS THE AREA. WL GO WITH CAT POPS NE NC AND THEN LKLY IN ADJACENT AREAS. HAVE DROPPED POS IN THE NRN AREA AS LOOKS LIKE NOT MUCH PUSH TO THE N SO SHD KEEP PRECIP TO THE S UNTIL TNGT. WL LOWER SOME MAXES OVR SRN PART OF THE AREA WHERE PRECIP IS OCCURRING. STORM DEVELOPING FOR SUN AND MON LOOKS INTERESTING WL HOLD COMMENTS TIL GET CHC TO STUDY NEW MODELS. FCSTID = 92 SBY 54 40 43 32 / 10 80 100 80 OXB 54 42 45 33 / 30 90 100 80 ECG 58 43 49 34 / 50 100 80 70 ORF 58 43 49 34 / 50 100 80 70 PHF 58 43 49 34 / 50 100 80 70 AKQ 58 43 44 33 / 40 100 80 70 RIC 56 40 44 33 / 30 100 90 70 FVX 58 43 44 33 / 40 100 80 70 .AKQ... MD...COASTAL FLOOD WATCH BEGINNING SUN NIGHT FOR ZONES MDZ024>025. NC...COASTAL FLOOD WATCH BEGINNING SUN NIGHT FOR ZONE NCZ102. VA...COASTAL FLOOD WATCH BEGINNING SUN NIGHT FOR ZONES VAZ077>078-VAZ084>086-VAZ091... VAZ094>095-VAZ098>100. va SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 240 AM MST SUN MAR 4 2001 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OVER ARIZONA TODAY AND MONDAY AS A LARGE STORM SYSTEM DEVELOPS OFFSHORE. MAINLY HIGH CLOUDS WILL SPREAD ACROSS THE STATE WHILE TEMPERATURES WARM. BY TUESDAY THE LOW WILL BEGIN TO ACCELERATE EASTWARD...WITH THICKER CLOUDS AND A MUCH BETTER CHANCE OF AT LEAST LIGHT RAIN ON THE SOUTHWEST DESERTS. AS THE CENTER OF THE LOW SHIFTS EASTWARD...A CLEARING TREND WILL TAKE OVER TOWARD THE END OF THE WEEK. .DISCUSSION... UPR RIDGE HAS PUMPED UP 500MB HEIGHTS ACROSS SWRN U.S. WITH BEST WARMING ALOFT SEEN AT DESERT ROCK NV. HUGE BAROCLINIC BAND SEEN DEVELOPING NEAR CA COAST LAST NIGHT WITH TROF AXIS TRYING TO TILT MORE N-S WITH TIME. LOOKING AT 300MB WINDS...100-120KT WINDS ARE FEEDING THE WEST FLANK OF THE LOW WITH AVN PICKING UP ON THIS LTL BETER THAN OTHER MODELS. ETA HAS MUCH MORE RIDGING OVER AZ THAN OTHERS...AND NOT SURE IF THE ETA IS CORRECT IN SHOWING MINOR S/WV APPROACHING THE BAJA WEST COAST AT 06Z. BY 12Z BOTH RUC AND ETA INDICATE STRONG DIFFLUENCE IN UPPER WINDS...WITH ETA BRINGING A SHORT WAVE INTO NW MEX AFT 18Z. AS IN THE PAST THE TIMING AND TRACK OF THE CLOSED LOW WILL BE MAIN FORECAST CHALLENGES. THE ADJUSTMENTS MADE SO FAR HAVE BEEN IN THE RIGHT DIRECTION...I THINK...WITH A LITTLE LATER ONSET TIME OF PCPN IN PHX WHILE THE FOCUS OF ACTIVITY REMAINS OVER SRN CA. STG FORCING COMBINED WITH HIGHER P/WTR VALUES CONTINUE TO APPEAR ON MODELS THIS MORNING. AVN SHOWS .6 TO .7 OVR PHX ON TUESDAY. HOWEVER...WILL PSBLY SEE DRY SLOT DEVELOP ALONG SOUTHWEST DESERTS BY MONDAY AFTERNOON AS LOW REORGANIZES ABOUT 250 MILES WEST OF LAX. THIS LEADS TO A STRONG SOUTHERLY GRADIENT AND SOME OROGRAPHICS THREAT FOR POINTS EAST AND NORTH OF GLOBE. I LIKE THE AVN/ETA BLEND WITH SYSTEM KICKING OUT AND WELL TO THE EAST OF US BY SATURDAY. WITH SNOWMELT IN HIGHER TERRAIN NEXT COUPLE DAYS...STREAM FLOWS TO INCREASE EVEN MORE. AT THIS TIME WE DO NOT CALL FOR ANY HVY PRECIP ON WATERSHED. SIPPLE az AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 325 AM EST SUN MAR 4 2001 --CURRENTLY-- AT 06Z SURFACE LOW CENTER WAS LOCATED OVER NE MS WITH THE COLD FRONT EXTENDING S FROM THIS LOW. LINE OF WEAKENING CONVECTION AHEAD OF THIS FRONT EXTENDED SW OVER OUR CWFA FROM S-CENTRAL GA INTO THE GULF. WATER VAPOR IMAGES SUGGEST SUBSIDENCE BEHIND A VORT MAX NOW OVER THE CAROLINAS HELPED TO WEAKEN THE CONVECTIVE LINE AROUND 03-04Z. PRIMARY STRONG VORT MAX IS LIFTING NE OVER TOWARD WRN TN AT THIS TIME. RECENTLY UPDATED ZONES TO REMOVE TORNADO WATCH. --FORECAST-- FIRST ISSUE IS TIMING END OF ONGOING PRECIPITATION...WHICH WILL BE LARGELY DICTATED BY RADAR TRENDS AT ZONE ISSUANCE TIME. 06Z RUC ADVERTISES PRECIP TO BE EAST OF OUR CWFA BY 18Z TODAY. NEXT ISSUE IS CLOUD COVER TODAY BEHIND FRONT. UPSTREAM METARS AND SATELLITE SHOW EXTENSIVE LOW CLOUDS BENEATH THE DRY SLOT ASSOCIATED WITH THE TN VORT MAX. BELIEVE LOW CLOUDS SHOULD BREAK BY AFTERNOON...ESPECIALLY WRN ZONES...SO WILL GENERALLY USE MOSTLY CLOUDY WORDING ACROSS THE BOARD. MODELS STILL ADVERTISE US TO BE COOL AND BREEZY IN WAKE OF STRONG NE USA STORM...SO NO SIGNIFICANT CHANGES TO THE CURRENT PACKAGE ARE PLANNED FOR TONIGHT THROUGH MONDAY NIGHT. IT IS INTERESTING TO NOTE THAT WE MAY ACTUALLY HAVE TO CONSIDER ISSUING WIND CHILL ADVISORIES FOR SOME AREAS MONDAY NIGHT/TUESDAY MORNING. MARINE - CURRENT BUOY DATA AND NUMERICAL GUIDANCE CLEARLY INDICATE OUR SMALL CRAFT ADVISORY NEEDS TO BE CONTINUED. WHAT IS LESS CERTAIN ARE OUR COASTAL FLOODING PROSPECTS. LATEST MODELS STILL ADVERTISE STRONG WLY GRADIENT FLOW OVER OUR WATERS TODAY BEHIND COLD FRONT. THIS FLOW WILL BE STRONG EARLY TONIGHT EVENING WHEN HIGH TIDE WILL OCCUR. FOR NOW WILL MENTION POSSIBLE MINOR FLOODING FOR DIXIE AND TAYLOR COUNTIES. DAY SHIFT CAN DETERMINE IF THIS NEEDS TO BE UPGRADED. FIRE WEATHER - NO CONCERNS TODAY...BUT FOR MONDAY AFTERNOON MUCH LOWER RH VALUES AND CONTINUED BREEZY CONDITIONS JUSTIFIES A WATCH. EXTENDED - MADE FEW CHANGES TO CURRENT PACKAGE. FEEDBACK ALWAYS WELCOME. PRELIMINARY NUMBERS... TLH 072/045 061/028 3000 PFN 068/048 064/041 0000 DHN 065/041 056/032 -000 ABY 068/042 056/030 -000 VLD 077/045 060/033 4000 .TLH... AL...NONE. GA...NONE. FL...SCA GMZ750-755-770-775. FIRE WEATHER WATCH MONDAY AFTN ALL AREAS. FOR A LIST OF COMMONLY USED ACRONYMS AND CONTRACTIONS...SEE OUR WEB PAGE AT HTTP://WWW.SRH.NOAA.GOV/TLH/TLH/CONTRACTIONS.HTML. TJT fl AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 235 AM CST SUN MAR 04 2001 MAIN FORECAST DILEMMA TO CONSIDER IN THIS MORNINGS FORECAST IS TO MAINTAIN FOCUS ON LOCAL ISSUES...AND NOT BE DISTRACTED BY THE IMPRESSIVE E COAST STORM TO COME. IN ACTUALITY...THIS STORM DOES DESERVE SOME ATTENTION AS IT WILL LIKELY RESULT IN A MAJOR FLOW REARRANGEMENT...AND AT LEAST WILL BE PARTIALLY RESPONSIBLE FOR OUR EASTERLY WX TRAJECTORY FOR THE NEXT 24 TO 36 HOURS. ISSUES TODAY ARE TRULY ONE OF HOW MANY CLOUDS IN THE SHORT TERM...THEN ATTEMPTING TO DEAL WITH TEMPERATURES AS THE COLD RIDGE SETTLES IN ACROSS THE AREA THROUGH TUESDAY MORNING. ETA/AVN PAINT RELATIVELY SIMILAR PICTURE. BACKDOOR CDFNT IS SLIDING THRU NERN CWA ATTM...MARKED BY A SUDDEN INCREASE IN NE WNDS TO A GUSTY 15 TO 25 KTS FOR A BRIEF TIME. ATM IS REALLY DRY NR FNT...AS INDICATED IN THE MPX RAOB THIS PAST EVNG. SOME FOG DEVELOPMENT OVR CWA IN REGION AHEAD OF CDFNT...WHICH WOULD LIKELY BE WORSE IF NOT FOR OUR GUARDIAN CIRRUS WHICH HAS DECIDED TO TAKE UP RESIDENCE IN THE UPR COL...PERIODICALLY ENHANCING AND DISSIPATING. 11-3.9 MICRON IMAGERY HAS INDICATED SOME PATCHES OF MORE SIG FOG BTWN JAMES AND MO RVRS. WL KEEP MNTN OF SOME EARLY MORNING FOG AHEAD OF THE FRONTAL FEATURE. LARGER MASS OF LO CLDS/FOG OVR WRN DKTS MAY ONLY BRIEFLY BRUSH FAR WRN CWA ERLY MORNING...BUT FCST RUC/ETA WINDS SHOULD HELP QUICKLY TRANSPORT THESE TO W. OTHER ISSUE IS TO WHAT DEGREE THERE WILL BE DEVELOPMENT OF LOW CLOUDS BEHIND FRONT. RUN TO RUN TREND IS FOR LESS AND LESS SIGNIFICANT CLOUDINESS...AND MORE IN NARROW BAND TRAILING FNT. FOR THE CURRENT TIME...GRTLKS TRAJECTORY HAS RESULTED IN SOME LOW CLOUDS STREAMING INTO NRN WI AND MN...BUT NOT A GREAT DEAL. OF MORE CONCERN ARE CLOUDS MASSING IN SWRN ONTARIO...BUT THOSE WOULD NOT BE UNTIL LATE TONIGHT...IN ASSOCIATION WITH SECONDARY IMPULSE OF CAA INDICATED ARND 850HPA LVL. LO LVL CYCLONIC FLOW MAXIMIZES LT TNGT AND EARLY MONDAY AS WELL...ESPLY THRU ERN CWA. POOR PERFORMANCE IN ELY FLOW IS COMMON...ESPLY HANDLING WWRD SURGES OF RH BLO WELL ESTABLISHED INVERSION. WL PLAY FOR MORE OPTIMISTIC FOR SUNSHINE OVERALL W WHERE SUBSIDENCE IN RIDGE AXIS MAXIMIZED...AND HIT CLDS A BIT HARDER IN BETTER CYCLONIC FLOW AND LAKE TRAJECTORY E. OTHER POSSIBILITY WOULD BE SOME CONVERGENCE OF MSTR ALG FRONTAL BNDRY ACRS W. AGAIN...VRRIFICATION HAS TOLD THE TALE OF MY COLD BIAS...AND AS MUCH AS SEEMS...DO NOT WANT TO LET THE BIAS...BIAS ME. IT IS A STRONGER SUN NOW AND SNOWCOVER IS NOT AS EFFECTIVE A RADIATOR AS BEFORE... HOWEVER...IN THE FACE OF SHALLOW COLD AIR AND EITHER E COMP OR LIGHT WINDS...AND SNOWCOVER...WL KEEP CRNT OR LOWER THAN GOING FCST. IN THE EXTENDED RANGE...ANY WARMING LOOKS TO BE RELATIVELY BRIEF...AND LIMITED TO WHAT OCCURS TUESDAY INTO TUESDAY NIGHT AS CLOUDS INCREASE...AHEAD OF NEXT NRN STREAM IMPULSE. JET ENTRANCE REGION WILL STILL BE PLAGUING THE REGION EARLY INTO TUESDAY WITH SFC RIDGE AXIS TAKING UP RESIDENCE NR I29. THIS SUGGESTS A LOW LVL AGEO E COMPONENT...AND EVEN ANTICIPATING RELAXING THIS OR STARTING A RETURN FLOW BY LATER IN DAY...LO LVLS WILL HAVE LIGHT TO ELY COMP WHICH IS DEATH TO A RAPID WARMUP. CONSISTENT ALSO FOR NUMBER OF RUNS WITH SHOT OF LIGHT SNOW TUES NIGHT...WITH BEST QG LIFT AND THERMAL RIBBON OVER NERN CWA. FOCUS WED SHIFTS TO POTENTIAL FOR PV IMPULSE AND CYCLONIC FLOW TO INDUCE A FEW SNOW SHOWERS IN MAINLY ERN CWA. THIS FOLLOWED BY ANOTHER COLD SHOT INTO REGION...WHICH SHUD LINGER INTO THU. AS WRMG ALFT BEGINS...AND SLOW RETREAT OF WK LO LVL FLOW IN SPRAWLING HIGH...KMML/K9V9 STAND HIER THREAT OF BEING WARMEST ON THU...THEN NICE WARMUP FOR FRI. MAIN ADJUSTEMENTS WILL BE MADE THRU THU. .FSD...NONE CHAPMAN sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TALLAHASSEE FL 738 AM EST SUN MAR 4 2001 --UPDATED SECTION-- UPDATED ZONES TO REMOVE RAIN FROM SW GA AND MOST OF FL BIG BEND. --END UPDATED SECTION-- --CURRENTLY-- AT 06Z SURFACE LOW CENTER WAS LOCATED OVER NE MS WITH THE COLD FRONT EXTENDING S FROM THIS LOW. LINE OF WEAKENING CONVECTION AHEAD OF THIS FRONT EXTENDED SW OVER OUR CWFA FROM S-CENTRAL GA INTO THE GULF. WATER VAPOR IMAGES SUGGEST SUBSIDENCE BEHIND A VORT MAX NOW OVER THE CAROLINAS HELPED TO WEAKEN THE CONVECTIVE LINE AROUND 03-04Z. PRIMARY STRONG VORT MAX IS LIFTING NE OVER TOWARD WRN TN AT THIS TIME. RECENTLY UPDATED ZONES TO REMOVE TORNADO WATCH. --FORECAST-- FIRST ISSUE IS TIMING END OF ONGOING PRECIPITATION...WHICH WILL BE LARGELY DICTATED BY RADAR TRENDS AT ZONE ISSUANCE TIME. 06Z RUC ADVERTISES PRECIP TO BE EAST OF OUR CWFA BY 18Z TODAY. NEXT ISSUE IS CLOUD COVER TODAY BEHIND FRONT. UPSTREAM METARS AND SATELLITE SHOW EXTENSIVE LOW CLOUDS BENEATH THE DRY SLOT ASSOCIATED WITH THE TN VORT MAX. BELIEVE LOW CLOUDS SHOULD BREAK BY AFTERNOON...ESPECIALLY WRN ZONES...SO WILL GENERALLY USE MOSTLY CLOUDY WORDING ACROSS THE BOARD. MODELS STILL ADVERTISE US TO BE COOL AND BREEZY IN WAKE OF STRONG NE USA STORM...SO NO SIGNIFICANT CHANGES TO THE CURRENT PACKAGE ARE PLANNED FOR TONIGHT THROUGH MONDAY NIGHT. IT IS INTERESTING TO NOTE THAT WE MAY ACTUALLY HAVE TO CONSIDER ISSUING WIND CHILL ADVISORIES FOR SOME AREAS MONDAY NIGHT/TUESDAY MORNING. MARINE - CURRENT BUOY DATA AND NUMERICAL GUIDANCE CLEARLY INDICATE OUR SMALL CRAFT ADVISORY NEEDS TO BE CONTINUED. WHAT IS LESS CERTAIN ARE OUR COASTAL FLOODING PROSPECTS. LATEST MODELS STILL ADVERTISE STRONG WLY GRADIENT FLOW OVER OUR WATERS TODAY BEHIND COLD FRONT. THIS FLOW WILL BE STRONG EARLY TONIGHT EVENING WHEN HIGH TIDE WILL OCCUR. FOR NOW WILL MENTION POSSIBLE MINOR FLOODING FOR DIXIE AND TAYLOR COUNTIES. DAY SHIFT CAN DETERMINE IF THIS NEEDS TO BE UPGRADED. FIRE WEATHER - NO CONCERNS TODAY...BUT FOR MONDAY AFTERNOON MUCH LOWER RH VALUES AND CONTINUED BREEZY CONDITIONS JUSTIFIES A WATCH. EXTENDED - MADE FEW CHANGES TO CURRENT PACKAGE. FEEDBACK ALWAYS WELCOME. PRELIMINARY NUMBERS... TLH 072/045 061/028 3000 PFN 068/048 064/041 0000 DHN 065/041 056/032 -000 ABY 068/042 056/030 -000 VLD 077/045 060/033 4000 .TLH... AL...NONE. GA...NONE. FL...SCA GMZ750-755-770-775. FIRE WEATHER WATCH MONDAY AFTN ALL AREAS. FOR A LIST OF COMMONLY USED ACRONYMS AND CONTRACTIONS...SEE OUR WEB PAGE AT HTTP://WWW.SRH.NOAA.GOV/TLH/TLH/CONTRACTIONS.HTML. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1110 AM EST SUN MAR 4 2001 12Z RAOBS/WV LOOP AND RUC ANAL SHOW INTENSE UPR LO MOVG WSW THRU SCNTRL ONTARIO UNDER BLOCKING UPR HI OVR NE CAN...WITH ELY 70+KT H3 JET ON NRN FLANK OF UPR LO MOVG SYS WWD. AXIS OF ENHANCED CLD AHD OF THIS FEATURE MOVG THRU CNTRL LK SUP. SAT PIX SHOWS SOME DRIER AIR BEHIND THIS CLD BAND OVR FAR NRN LK SUP...BUT MORE ENHANCED CLD NOTED MOVG SWWD ACRS SRN ONTARIO WITH STEADY -SN OBSVD AT CYGQ. CORE OF COLDEST AIR IN NE ONTARIO...WHERE H85 TEMP DOWN TO -20C AT CWZC. ENHANCED CLD LINES UP VERY WELL WITH LOWEST H85 TEMPS. ALTHOUGH H85 TEMPS A MARGINAL -12 TO -15C (DELTA T UP TO 16C) OVR LK SUP...UVV ASSOCIATED WITH CLD BAND AND SFC CYC FLOW HAS RESULTED IN SOME ENHANCED SHSN ACTIVITY WITH VSBY AT CMX DROPPING AS LO AS 3/4SM ALG AXIS OF LLVL CNVGC... WHICH HAS NOW SHIFTED TO THEIR S. EARLIER 88D SHOWED LES BAND AND REFLECTIVITY UP TO 28 DBZ OVR ERN MQT COUNTY WITH FVRBL 340-360 FLOW UNDER INVRN HGT ARND 8K FT MSL PER VWP...BUT LAST FEW IMAGES INDICATE COLLAPSE OF BAND AND MORE GENERAL SHSN AREA AS DRIER AIR FM THE N MAY BE HAVING AN IMPACT. MAIN FCST CONCERN TDAY IS SHSN TREND AND GOING HEADLINES. 12Z ETA AND NGM SHOW UPR LO CONTG TO WSW TDAY WITH H5 VORT CENTER AND H85 -20C COLD POCKET REACHING NR CYQT BY 00Z WITH STEADILY DCRSG H85 TEMPS OVR THE LK THIS AFTN. AS ENHANCED UVV ASSOCIATED WITH UPR CLD BAND CONTS SWWD DURG DAY AND SOMEWHAT DRIER AIR NOW OVR NRN LK SUP MOVES IN BEHIND...XPCT A FEW HRS BRK IN THE SHSN THIS AFTN OVR THE W BEFORE INCRSG DESTABILIZATION STARTS UP MORE PURE LES AGAIN LATER. LESS OF A BRK ACRS THE E WHERE VIGOROUS H85-5 QVECTOR CNVGC/H7 UVV PROGGED TO IMPACT THE ERN HALF OF LK ALL DAY ON CYC SIDE OF VORT TRACK AND MAINTAIN MORE LK ENHANCED ACTIVITY WHERE FETCH IS LONG ENUF TO ALLOW SGNFT MOISTENING/DESTABILIZATION. NEW ETA SHOWS ENHANCED LLVL CNVGC INTO NCNTRL ZNS...WITH CENTER OVR WRN MQT COUNTY AND DCRSG VERTICAL SHEAR. BUT LACK OF FETCH INTO ERN ALGER/LUCE WITH NO LLVL CNVGC. LES CHART SUGS 1-3" ACCUM DURG AFTN FOR 6HR LK ENHANCEMENT AND H85 DELTA-T UNDER 17C. ALTHOUGH DELTA-T WL INCRS OVR THIS THRESHOLD AFTER 21Z WITH ARRIVAL OF COLDER AIR...NNELY LLVL FLOW NOT AS FVRBL THERE...SO NO EXTRA ACCUM FCST FOR THOSE ZNS. ONLY MINOR CHGS TO FCST TEMPS. .MQT...LAKE EFFECT SNOW WARNING LATE THIS AFTN THROUGH MONDAY MIZ005. LAKE EFFECT SNOW ADVISORY LATE THIS AFTN THROUGH MONDAY MIZ001>004-006. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1100 AM EST SUN MAR 4 2001 CURRENT VISIBLE SATELLITE SHOWING LAKE EFFECT SNOW BANDS ALREADY DEVELOPING OVER NORTHERN LAKE MICHIGAN... AS 850 MB TEMPERATURES CONTINUE TO DROP FROM -9C THIS MORNING TO -14C THIS AFTERNOON. THE LATEST RUC SHOWS 1000/850 MB MEAN WINDS REMAINING FROM THE NORTH/NORTHEAST THROUGH THE AFTERNOON... WITH 900/700 MB MOISTURE INCREASING OVER NORTHERN LAKE MICHIGAN TO AROUND 80 PERCENT BY 18Z. MODEL SOUNDINGS SHOW AFTERNOON INVERSION HEIGHTS AROUND TRAVERSE CITY AREA ONLY INCREASING TO AROUND 3500 FEET TODAY...THEREFORE LAKE EFFECT SNOW ACCUMULATIONS ALONG THE LAKE MICHIGAN SHORELINE WILL BE LIMITED TO UNDER 2 INCHES. ACROSS NORTHERN MICHIGAN...850/500 MB QVECTOR CONVERGENCE WILL AFFECT EAST UPPER AND THE STRAITS REGION INTO THIS EVENING... AS THE 500 MB LOW DROPS INTO EASTERN UPPER MICHIGAN. MODEL SOUNDINGS SHOW GOOD MOISTURE EXTENDING UPPER FROM THE SURFACE THROUGH 650 MB... THEREFORE WILL LEAVE SCATTERED SNOW SHOWERS ACROSS EAST UPPER AND THE STRAITS REGION INTO THIS EVENING. FOR NORTHEAST LOWER...LAKE EFFECTS WILL BE LIMITED AS 850 MB TEMPERATURES WILL BE MUCH WARMER THAN THOSE SEEN ON THE LAKE MICHIGAN SIDE. 850 MB TEMPERATURES WILL ONLY COOL TO AROUND -10C THIS AFTERNOON. 1000/850 MEAN WINDS WILL BE GENERALLY FROM THE NORTHEAST SO WILL MENTION PARTLY SUNNY SKIES AND A FEW FLURRIES THIS AFTERNOON. FOR INTERIOR LOCATIONS AWAY FROM THE LAKESHORES AND SOUTH OF THE UPPER LOW... WILL GO WITH CURRENT VISIBLE SATELLITE TRENDS OF PARTLY SUNNY...WHILE WARMING AFTERNOON TEMPERATURES UP A LITTLE. .APX...NONE. SWR mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1149 AM EST SUN MAR 04 2001 NO UPDATE PLANNED FOR THE AFTERNOON. VARIABLE CLOUDINESS CURRENTLY COVER THE REGION. TEMPERATURES IN THE LOW 30S. NEUTRAL COLD AIR ADVECTION NOTED FROM THE RUC...WITH SOME SUN...VALUES SHOULD GO UP A COUPLE OF DEGREES...CLOSE TO FORECAST VALUES. .GRR...NONE. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA NE 310 PM CST SUN MAR 4 2001 THE FORECAST CONCERNS THROUGH TUESDAY ARE CLOUDS AND TEMPERATURE. CURRENTLY...AN ELONGATED BAND OF LOW SC LIES ON THE WEST EDGE OF A SFC HIGH...AND EXTENDS FROM S CENTRL KS AND ERN/CNTRL NEB NORTHWEST INTO EAST SASK. IN OUR AREA THE EAST EDGE OF THE CLOUDS HAS BEEN PUSHING SLOWLY E ON NW LOW LEVEL FLOW...BUT ALSO DEVELOPING SOME BREAKS. CLOUD MASS LOOKS SOMEWHAT MORE SOLID IN DKTS. ANOTHER SOMEWHAT HIGHER BASED AREA OF SC IS IN PATCHES OVER NE MN AND NRN WI IN A MORE CYCLONIC FLOW AREA AROUND PLUNGING UPPER LOW AND COLD POOL. IN NEAR TERM...EXPECT LOW CLOUDS TO STALL AND THEN BEGIN MOVING WEST OVERNIGHT AS LOW LEVEL FLOW BACKS SOMEWHAT INTO THE NORTH...A TREND SUPPORTED BY 18Z RUC AND ETA. COLD ADVN HAS KEPT TEMPS FROM RISING VERY FAST THIS AFTERNOON...AND THEY SHOULD DROP OFF FAIRLY RAPIDLY TONIGHT IN THE CLEAR AREA. TEMPS MAY EVEN END UP A BIT COLDER THAN CURRENT FORECAST. CLOUD COVER TOMORROW INTO TUESDAY WILL BE IMPORTANT TO TEMPS...BUT MODELS ARE NOT MUCH HELP WITH SHALLOW INVERSION OVER SNOW COVER. MESOETA DEVELOPS HIGH RH ACROSS THE AREA MONDAY BY MERGING THE WESTERN SC AREA WITH THE OTHER AS IT BACKDOORS FROM THE NORTHEAST. I HAVE SOME TROUBLE ACCEPTING THIS SOLUTION AS CYC FLOW WILL NOT BE STRONG OVER OUR AREA. LEAVING PC IN CURRENT FORECAST SEEMS PRUDENT...WITH TEMPS A STEP DOWN FROM TODAY. THERE IS DECENT AGREEMENT ON LOW LEVEL DRYING MONDAY NIGHT...WITH LOWS AGAIN A BIT COLDER THAN TONIGHT. SFC HIGH BEGINS TO DRIFT EAST ON TUESDAY WITH RETURN FLOW ONCE AGAIN BRINGING CLOUDS IN FROM THE WEST. TEMPS WARM ALOFT...BUT MAY END UP SIMILAR TO MONDAY NEAR SFC WITH LIGHT WIND. AS CLOUDS THICKEN AND MINOR LIFT DEVELOPS TUESDAY NIGHT...SOME LIGHT SNOW COULD DEVELOP ALONG WITH LESS COLD TEMPS. ETA IS SLOWER AND DEEPER WITH TROUGH IN THE NORTHERN BRANCH BY LATE TUESDAY...AND IS MORE EXTREME THAN MOST OTHER SOLUTIONS. WILL LEAN TOWARD SOMEWHAT FASTER AND WEAKER AVN FOR NOW...BUT ACCEPT OVERALL MODEL TENDENCY TOWARD INCREASED UPPER TROUGHING. THIS WOULD NOT CHANGE THE FORECAST MUCH FOR TUESDAY NIGHT...BUT WOULD AFFECT THE EXTENDED. OVERALL WILL STICK FAIRLY CLOSE TO AVN MOS...WHICH RESEMBLES PREVIOUS FORECAST...WITH SOME ADJUSTMENTS FOR SNOW COVER CURRENTLY THINNING AROUND LNK AND OMA...AND OF COURSE CLOUDS. IN THE EXTENDED...WILL LEAN MORE TOWARD GREATER COLD AIR PENETRATION INTO THE REGION THURSDAY AND FRIDAY AS TROUGHING IN THE NORTHERN BRANCH IS MORE PREDOMINANT THAN PREVIOUS MODEL RUNS. WILL LOWER GUIDANCE TEMPS BUT KEEP AREA MAINLY DRY AS SOUTHERN BRANCH IS SUPPRESSED FARTHER SOUTH. SATURDAY WILL PROBABLY BE A DAY OF RECOVERING TEMPS IN ADVANCE OF ANOTHER SYSTEM COMING INLAND FROM THE WEST COAST. THIS COULD PRODUCE LIGHT WARM ADVN PRECIP AS EARLY AS SUNDAY. .OMA...NONE. POLLACK ne AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 210 PM MST SUN MAR 4 2001 CURRENT SURFACE MAP SHOWS HIGH PRESSURE RIDGE ACROSS EASTERN DAKOTAS...WITH LEE TROF DEVELOPING IN CENTRAL MONTANA/WYOMING. PERSISTENT LOW CLOUDS AND FOG OVER FAR EASTERN PART OF CWA...WITH EROSION ON THE WESTERN FLANK. PROBLEM TONIGHT WILL BE HOW FAR LOW CLOUDS MARCH BACK TO THE WEST. 12Z/18Z ETA AND 18Z RUC HAVE A GOOD HANDLE ON LOCATION OF LOW CLOUDS...AND WILL FOLLOW THE ETA/RUC FOR TONIGHT. HIGH PRESSURE RIDGE WILL REMAIN OVER EASTERN DAKOTAS TONIGHT...WITH WINDS TURNING EAST-SOUTHEAST. 12Z KBIS SOUNDING INDICATES THAT THE COLD/MOIST AIR IS DEEP ENOUGH TO PUSH UP AGAINST EASTERN SLOPES OF THE BLACK HILLS. FORECAST SOUNDINGS SUPPORT SHALLOW LAYER OF CLOUDS/FOG INTO THE RAPID CITY AREA...AND MUCH DEEPER OVER LOWER ELEVATIONS IN THE EASTERN CWA. WILL GO WITH CLOUDS/FOG SPREADING ACROSS ALL AREAS EXCEPT FAR SOUTHWEST...BLACK HILLS AND NORTHEAST WYOMING. WILL WORD NORTHERN FOOTHILLS AS CLEAR AROUND SPEARFISH...WITH LOW CLOUDS/FOG INTO STURGIS. WITH THE WEAK UPSLOPE FLOW...AND WEAK SHEAR LAYER ABOVE THE SHALLOW MOISTURE...I DO NOT EXPECT A PROBLEM WITH FREEZING DRIZZLE. FOR MONDAY...QUESTION WILL BE HOW MUCH OF WESTERN SOUTH DAKOTA WILL CLEAR OUT OF THE LOW CLOUDS AND FOG. SOUTHEAST WINDS WILL CONTINUE THROUGH THE DAY...AND WILL KEEP MOST OF THE PLAINS IN THE LOW CLOUDS. EXCEPTION WILL BE WESTERN FRINGE WHERE MIXING WILL ERODE SOME OF THE CLOUDS. ALSO...DRIER AIR WORKING IN FROM THE EAST MAY CLEAR OUT FAR SOUTH CENTRAL COUNTIES LATER IN THE DAY. BIG RANGE IN TEMPERATURES OVER A SHORT DISTANCE FROM THE BLACK HILLS TO THE PLAINS. CLOUDS SHOULD PERSIST INTO MONDAY NIGHT...HOWEVER AS SURFACE TROF MOVES WEST TO EAST...MIXING AND DRIER AIR WILL HELP TO ERODE LOW CLOUDS. MIXING DURING THE DAY TUESDAY WILL ALSO BRING SOME WARMER TEMPERATURES TO THE PLAINS. COLD FRONT FORECAST TO MOVE THROUGH LATE IN THE DAY. IN THE EXTENDED...THERMAL TROF OVER THE REGION ON WEDNESDAY. COULD BE A FEW SNOW SHOWERS DURING THE EARLY MORNING HOURS OVER THE NORTHERN BLACK HILLS AND NORTHEAST WYOMING. WILL LEAVE OUT FOR SNOW AS IT IS ONLY A SLIGHT CHANCE. DRY THURSDAY AND FRIDAY WITH SEASONABLE TEMPERATURES. STILL A CHANCE OF SNOW SATURDAY...AND DRY AND COLD SUNDAY. .UNR...NONE. KC sd