INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 300 PM PST FRI NOV 29 2002 IR SATELLITE LOOP ALONG WITH RUC ANALYSIS HAS THE UPPER LOW CLOSER 30N/120W AND SLOWLY LIFTING NORTHEAST. BASED ON REGIONAL DOPPLER RADAR ANALYSIS...PRECIP REMAINS VERY ISOLATED AND STILL CONFINED TO EASTERN KERN COUNTY THIS AFTERNOON. INSTABILITY ANALYSIS FROM UPPER AIR OBSERVATIONS SHOWED THE BETTER LI/S AND CAPE VALUES IN THE VICINITY OF SAN DIEGO AND TAPERED OFF FURTHER NORTH. IN ADDITION... MODELS INITIALIZED PRECIPITABLE WATER VALUES WELL OVER THE SOUTHWEST AND SHOWED A NORTHWARD TRAJECTORY INTO THE DISTRICT THROUGH SATURDAY. WITH THE SUBTROPICAL MOISTURE SOURCE WRAPPING AROUND THE UPPER LOW...FEEL THAT SATURDAY WILL SEE THE BEST CHANCES OF PRECIP AS THE MOISTURE PUSHES IN AND THE LOWER LAYER MOISTEN UP. YET...WILL LEAVE A MENTION OF POPS OVER ALL BUT THE CENTRAL SAN JOAQUIN VALLEY TONIGHT AS MOISTURE CONTINUES TO STREAM IN THE DISTRICT. AS SATURDAY WILL BE THE BETTER DAY FOR POSSIBLE PRECIP. THEREFORE...WILL MAINTAIN CURRENT WORDING OF CHANCE/SCATTERED/ OVER THE HIGHER ELEVATIONS AND SLIGHT CHANCE/ISOLATED/ OVER THE VALLEY DURING SATURDAY. MODELS ARE IN GOOD AGREEMENT WITH PLACING THE CENTER OF THE UPPER LOW NEAR BARSTOW/EDWARDS SATURDAY AFTERNOON AND CONTINUING TO LIFT IT NORTHEAST SUNDAY MORNING. DURING THE AFTERNOON HOURS...PIECES OF ENERGY ROTATING AROUND THE LOW WILL PROVIDE ENOUGH DYNAMICS FOR SHOWER ACTIVITY. AS THE LOW LIFTS NORTHEAST LATE SATURDAY...THE LAST PIECE OF ENERGY SWINGING BACK OVER THE SOUTHERN SIERRA WILL ALLOW SHOWERS TO LINGER THROUGH THE SUNDAY MORNING HOURS. BY SUNDAY AFTERNOON...THE LOW WILL BE FURTHER INTO NEVADA ALLOWING THE DISTRICT TO START DRYING OUT. DURING THIS TIME... THE RIDGE WILL START REBUILDING OVER THE WEST COAST. OVERNIGHT SUNDAY INTO MONDAY MORNING MAY SEE A RETURN TO FOGGY CONDITIONS AS THE RIDGE BECOME THE DOMINATE FEATURE OVER THE AREA. YET...DURING THE DAY...CONDITIONS WILL CLEAR OUT SIMILAR TO PREVIOUS DAYS WITH PATCHY FOG. FOR THE EXTENDED PERIOD...ALL EXTENDED PERIOD MODELS APPEAR TO HAVE INITIALIZED VERY WELL WITH THE TRACK OF THE LOW CURRENTLY OVER THE CWA...SO CANNOT DISMISS ANY SOLUTIONS OUTRIGHT. FORTUNATELY THE GFS...ECMWF...AND WRNOGAPS ALL HAVE VERY SIMILAR SOLUTIONS THROUGH THEIR RESPECTIVE TIMEFRAMES...SO THERE IS NO NEED TO PICK FAVORITES. THE ONE EXCEPTION IS MONDAY. THE GFS TRIES TO LINGER THE HIGH RH FIELD OVER THE CWA FOR ABOUT 12 HOURS LONGER THAN NOGAPS AND ECMWF. HOWEVER...THIS WILL NOT BE AN ISSUE UNTIL TOMORROW AFTERNOON/S FORECAST WHEN SUNDAY NIGHT BECOMES A FORECAST PERIOD...BECAUSE THE CURRENT WORDING OF DECREASING CLOUDS ON SUNDAY AND MOSTLY CLEAR MONDAY WILL WORK REGARDLESS. A STRONG H5 RIDGE BUILDS IN MONDAY...WITH THE LAYER ATMOSPHERE VERY DRY. SKIES WILL BE MOSTLY CLEAR...IF NOT CLEAR OUTRIGHT...MONDAY THROUGH THURSDAY...WITH NEAR NORMAL TEMPERATURES...EXCEPT A BIT BELOW NORMAL AT NIGHT WITH RADIATIONAL COOLING AND SUCH A DRY BOUNDARY LAYER. SOME FROST IS POSSIBLE WEDNESDAY AND THURSDAY NIGHTS. THIS NOCTURNAL COOLING WILL AID IN DENSE FOG DEVELOPMENT THAT WILL INCREASE IN COVERAGE AND DENSITY EACH NIGHT THROUGH THURSDAY. THE NEXT WEATHER MAKER WILL BE APPROACHING ON FRIDAY ACCORDING TO THE THREE PREVIOUSLY MENTIONED MODELS. AN UPPER LEVEL LOW WILL BE ON THE HNX DOORSTEP BY THE END OF THE DAY ON FRIDAY. IT IS NOT A PARTICULARLY POTENT SYSTEM...AND IT WEAKENS RAPIDLY ONSHORE...BUT INCREASING CLOUDS SHOULD OCCUR FRIDAY...SO THAT WORDING WILL BE ADDED TO FRIDAY. IF ANY PRECIP COMES OUT OF THIS SYSTEM IT WILL BE SATURDAY. THEREFORE...THE ENTIRE EXTENDED FORECAST WILL HAVE ZERO POPS. MOLINA/SOWKO .HNX...NONE. ca EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 930 PM EST FRI NOV 29 2002 THIN LAYER OF CIRRUS WILL BE THE ONLY CLOUDS OVERNIGHT. 30/00Z TAMPA UPPER AIR SOUNDING INDICATED A SHALLOW WESTERLY FLOW WAS BRINGING A LITTLE MOISTURE INTO THE CENTRAL PENINSULA. LOOP OF DEW POINT TEMPERATURES/TD ALSO SHOWS SOME INCREASE IN MOISTURE AS TD/S HAVE GONE FROM AROUND 33F TO AROUND 36F IN WESTERN LAKE. ELSEWHERE TD/S WERE GENERALLY IN THE MID/UPPER 30S INTERIOR TO THE MID 40S ALONG THE COAST. LATEST RUC SOUNDINGS AND T/TD FORECASTS INDICATE THAT PATCHY FROST STILL POSSIBLE ACROSS PORTIONS OF EAST CENTRAL FLORIDA ...ESPECIALLY AWAY FROM THE COAST AND IN SHELTERED AREAS AS TEMPERATURES DROP DOWN TO THE UPPER 30S/AROUND 40 IN THOSE LOCATIONS. MARINE...CURRENT OFFSHORE WEATHER BUOYS RECORDING WINDS 270-290 AT 6 TO 10 KNOTS...A FEW GUSTS TO 14...AND 4 TO 5 FOOT SEAS. DROPPING THE SMALL CRAFT ADVISORY FOR SEAS IN THE GULF STREAM AS WINDS BACK AROUND TO THE WEST AND NORTHWEST OVERNIGHT. .MLB...NONE. WIMMER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 850 PM EST FRI NOV 29 2002 ANOTHER CHILLY NIGHT ON TAP...BUT NOT AS COLD AS THIS MORNING'S RECORD FREEZE (25 DEGREES AT TLH). WATER VAPOR/RUC H5 COMPOSITE SHOWS CONSIDERABLE MOISTURE FROM SRN PLAINS RIDING UP & OVER WEAK S/WAVE RIDGE ALONG GULF COAST. REGIONAL IR IMAGERY SHOWS CIRRUS HAS EXITED OUR ERN ZONES W/ MOSTLY CLEAR SKIES. MORE MID/HIGH CLOUDS ASSEMBLING TO OUR W WILL EVENTUALLY OVERSPREAD THE CWFA OVERNIGHT. LOCAL AIRMASS REMAINS QUITE DRY/STABLE (PWAT=0.25/LI=23)...BUT SIG WARMING OF H5-H9 LAYER DURING PAST 24 HRS UNDER WLY FLOW. CURRENT TEMPS/DEW POINTS W/I FEW DEGREES OF MOS. PER SATELLITE TRENDS...WILL CHANGE M/CLEAR TO INCREASING CLOUDS. THIS SHOULD LIMIT RADIATIONAL COOLING...MAINLY W OF AQQ RIVER. FOR AREAS TO THE E...THE MERCURY SHOULD BOTTOM OUT TO NEAR FREEZING OVERNIGHT...THEN STEADY OR SLOWLY RISE TOWARD MORNING. WILL TWEAK MIN TEMPS. PATCHY FROST STILL POSSIBLE W/ NEAR CALM WINDS OVER ERN ZONES. OVER COASTAL WATERS...WINDS HAVE BECOME S-SW. SPEEDS WERE ~10 KTS W/ SEAS 2 FT OR LESS. WINDS GRADUALLY INCREASE OVERNIGHT AS PRESSURE GRAD TIGHTENS AHEAD OF APPROACHING COLD FRONT FROM NW. .TLH... AL...NONE. GA...NONE. FL...NONE. MAJ fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 900 PM CST FRI NOV 29 2002 MAIN CONCERN IS WITH WINDS OVERNIGHT THROUGH SAT MORNING. ARCTIC FRONT EXTENDS ROUGHLY FROM SOUTH OF SIOUX FALLS SD TO NEAR LACROSSE WI. STRONG 3-HR PRESSURE RISE BULLSEYE OVER NORTHEAST SD OF 7 MBS CORRELATES WELL WITH MAIN CORE OF STRONGEST WINDS SUSTAINED AT OVER 30 KTS WITH GUSTS UP TO 45 KTS OR SO IN SOUTHWEST MN AND NORTHEAST SD. RUC CONSISTENT WITH OTHER MODELS IN TAKING THIS PRESSURE RISE MAX SE THROUGH SOUTHERN IA AND NORTHERN MO AROUND 12Z. SO THIS AREA MAY SEE STRONGEST WINDS. HOWEVER...LATEST OBS SHOW WINDS IN SE MN POST FRONTAL SUSTAINED AT 30 TO 35 MPH WITH GUSTS OVER 40 MPH. SO FAIRLY CONFIDENT WE/LL SEE ADVISORY CRITERIA FOR A PERIOD POST FRONTAL AND WILL RAISE WIND ADVISORY OVERNIGHT THROUGH SATURDAY MORNING. REST OF FORECAST LOOKS ON TRACK WITH FLURRIES AND FEW PERIODS OF LIGHT SNOW ACCOMPANYING COLD AIR. WILL BE DRASTIC CHANGE FROM MILD DAY TODAY IN WHICH HIGHS TOPPED OUT IN THE UPPER 4OS TO NEAR 60 DEGS!!! THANX LOT FOR GREAT COORDINATION! .DVN... IA...WIND ADVISORY EASTERN IOWA OVERNIGHT AND SATURDAY MORNING. IL...WIND ADVISORY NORTHWEST AND WEST CENTRAL ILLINOIS LATE TONIGHT AND SATURDAY MORNING. MO...WIND ADVISORY FAR NORTHEAST MISSOURI LATE TONIGHT AND SATURDAY MORNING. 05 il AREA FORECAST DISCUSSION/SUPPLEMENTAL NATIONAL WEATHER SERVICE CHICAGO IL 845 PM CST FRI NOV 29 2002 PUBLIC DISCUSSION FOR 900 PM ZONE UPDATE BIG DISCUSSION AMONG FCSTRS CONCERNING POTL FOR HIGH WIND ADVISORIES FOR LATE TONIGHT AND SAT. NEW RUC RUN SUPPORTS EARLIER MDL RUNS IN BRINGING SHEARED VORT CENTER S AND W OF FA...FROM NERN SD /WHERE IT INTIIALIZED WELL BASED ON SATLT LOOPS/...ACROSS WRN IA AND EVENTUALLY INTO LOWER OH VLY ON SAT. THIS WOULD SUGGEST THAT STRONGEST MOMENTUM TRANSPORT ASSD WITH NOSE OF STGST PRESSURE RISES WILL PASS WELL TO W AND S. THEREFORE...AT THIS TIME IT IS EXPECTED THAT VERY HIGH WIND GUSTS TO 50 KTS REPORTED IN PAST HR ACRS SWRN MN/SERN SD WILL PASS TO W AND S OF FA. SFC-H85 TRAJECTORY FCSTS AND SATLT LOOPS ALSO SHW FLOW INTO CHI FA COMING FROM WRN WI IN 12HRS AND WRN ONT IN 24 HRS. UPSTREAM WINDS IN THIS REGION ARE GENLY ARND 20 KTS WITH GUST TO 30. SO...ALTHOUGH PERIOD FROM LATE TONIGHT INTO SATURDAY AFTERNOON WILL NOT BE A PICNIC BY ANY MEANS...WINDS WILL LIKELY STAY BELOW ADVISORY CRITERIA: /SUSTAINED AT 30 MPH OR MORE FOR AT LEAST 1 HR...OR GUSTS TO 45 MPH/. .CHI...GALE WARNING LAKE MI THRU SAT NIGHT MERZLOCK AVIATION DISCUSSION FOR 00Z TAFS MAIN AVIATION CONCERN THIS CYCLE IS WINDS. DEEP LOW MOVES ACROSS ONTARIO TONIGHT. COLD FRONT PROGGED TO COME THROUGH AROUND OR JUST BEFORE DAWN, 08Z-10Z. WESTERLY WINDS INCREASE TO 30KTS AHEAD OF FROPA OVERNIGHT THEN TURN NW UP TO 40KTS DURING MUCH OF THE MID TO LATE MORNING, SLOWLY DIMINISHING DURING THE AFTERNOON. MID/HIGH LEVEL CLOUDS DEPARTING TO THE SOUTHEAST TONIGHT, WITH BAND OF STRATOCU PUSHING ACROSS NORTHERN IA AND SOUTHWEST WI. THIS TO MOVE ACROSS TERMINALS 04-06Z. CURRENT TAFS HAVE SOME -SHSN WITH NO RESTRICTION TO VIS. WILL CONTINUE THIS MENTION OF A FEW PASSING -SHSN OR FLURRIES BUT ANY PRECIP TO BE VERY LIGHT. MAY ALSO SEE SOME MVFR FOR A TIME WITH FROPA. CMS il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1045 PM EST FRI NOV 29 2002 MAIN FORECAST CONCERNS OVERNIGHT ARE LES/WIND. WV IMAGERY AND RUC ANALYSIS INDICATED SHRTWV/VORT JUST NE OF LK SUPERIOR. AT THE SFC...979 MB LO WAS LOCATED OVER NE ONTARIO NEAR JAMES BAY WITH A COLD FRONT EXTENDING SE TOWARD NRN LK MI. 3 HR PRES RISE MAX OF 6 MB WAS SAGGING THROUGH WRN LK SUPERIOR WITH BEST ISALLOBARIC GRADIENT JUST BEHIND THE FRONT WHERE WINDS HAVE GUSTED TO AROUND 40 MPH ACRS CNTRL UPR MI. RADAR SHOWED RETURNS FILLING IN AGAIN ACRS N UPR MI FOLLOWING BURST OF SN WITH THE FRONT. SNOWFALL AMOUNTS UP TO 3 INCHES HAVE ALREADY BEEN REPORTED AT WAKEFIELD. H8 TEMPS TO AROUND -10C WITH LK-H8 DELTA/T TO 15C WILL DROP TO NEAR -15C BY 12Z/SAT. 00Z KINL/CWPL SNDGS INDICATED VERY MOIST LOWER/MID TROP PROFILE WITH INVERSION HGTS NEAR 8K FT. COMBINATION OF ABUNDANT UPSTREAM MOISTURE AND INCREASING INSTABILITY OVER THE LAKE WILL WILL CONTINUE TO INTENSIFY LES. MDLS HAVE BEEN CONSISTENT WITH FCST OF GRADUALLY VEERING VERY STRONG CBL WINDS (30-40 KT) FROM 320-330 TO AROUND 350 BY 12Z/SAT. FAVORED AREAS FOR GREATEST ACCUMULATIONS WILL BE NEAR IWD AND OVER NORTH CNTRL UPR MI IN THE HIGHER TERRAIN WHERE ORAGRAPHIC CONTRIBUTION IS GREATEST. WITH STRONG WINDS LES SHOULD ALSO PENETRATE INTO NRN PORTION OF SRN TIER COUNTIES AND ACRS MUCH OF ERN DELTA AND SCHOOLCRAFT COUNTIES AS REFLECTED IN CURRENT FCST. ETA DEPICTION OF STRONG 850-500 MB DRYING FROM 09Z-12Z SEEMS REASONABLE GIVEN WV/IR INDICATION OF DRYING OVER NW ONTARIO. SO...GOING FCST OF DIMINISHING LES DURING THE MORNING LOOKS ON TRACK. BASED ON CURRENT TRENDS...HAVE ONLY MADE MINOR ADJUSTMENTS TO SNOWFALL AMOUNTS OVERNIGHT. .MQT...WINTER STORM WARNING OVERNIGHT INTO SAT MORNING MIZ001>004-009-084. WINTER STORM WARNING OVERNIGHT THRU SAT MORNING MIZ005. WINTER STORM WARNING OVERNIGHT THRU SAT MIZ006-007-085. LAKE EFFECT SNOW AND BLOWING SNOW OVERNIGHT INTO SAT MORNING MIZ010. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY LATE THIS EVNG THRU SAT MIZ013-014. WINTER STORM WATCH SAT NIGHT AND SUN MIZ001>007-009-084-085. GALE WARNING LK SUPERIOR. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 355 PM EST FRI NOV 29 2002 MAIN FORECAST CONCERN IN THE SHORT TERM (TONIGHT) IS POTENT COLD FRONTAL PASSAGE AND RESULTANT SNOW/WIND. ARCTIC COLD FRONT CURRENTLY STRETCHING FROM PARENT 976MB LOW IN CENTRAL ONTARIO THROUGH EXTREME NRN MN AND ND. SHARP THERMAL CONTRAST ALONG FRONT...WITH TEMPS STILL IN UPR 30S IN MN ARROWHEAD AND TEENS IN MANITOBA AND NW ONTARIO. EVEN SOME AFTERNOON TEMPS BELOW ZERO IN NRN MANITOBA...BRRR. MID CLDS GRADUALLY LOWERING IN THE U P OVER PAST COUPLE HOURS...BUT W/ H85 TEMPS ONLY SLIGHTLY BELOW ZERO (-4C PER RUC)...STILL AWAITING FRONT AND CAA BEFORE SHSN DEVELOP OUT WEST. SHSN SHOULD DEVELOP IN BIG WAY ONCE FROPA OCCURS. ETA BUFKIT CONTINUES TO SHOW 6-8 HOUR PERIOD OF LITTLE TO NO INVERSION... ENCOMPASSING FAVORABLE SNOW GROWTH REGION AS H85 TEMPS DROP TO -12C TO -15C OVERNIGHT. UPSTREAM RAOBS (CWPL/CYQD) SHOW PLENTY OF MOISTURE AS WELL. THOUGH MODELS (GFS AND ETA) SHOW SOME DRYING IN WRN PARTS AT 850-700MB BY 12Z SAT...THIS STILL LEAVES PLENTY OF TIME FOR SOME SIGNIFICANT SNOW ACCUMS TONIGHT. WINDS ALSO MAJOR CONCERN AS ETA BUFKIT HAS BEEN PERSISTENT IN SHOWING 45KT WIND SPEED MAX AT 3-4KFT OVERNIGHT. WITH CURRENT GALES OVER LAKE AND GUSTY WINDS REPORTED BY UPSTREAM SFC OBS...THIS SEEMS VERY REASONABLE. WILL KEEP WITH HIGH END GALES OVERNIGHT. WINDS WILL ALSO ACT TO PUSH SNOW BANDS WELL INLAND...THOUGH AT THE SAME TIME DECREASING FETCH TIME OVER THE WEST (ABOUT 2 HRS...GIVEN 80 MILES OF LAKE AND 40MPH WIND). OVERALL AMOUNTS WILL BE SIMILAR... WITH OROGRAPHIC HELP OUT WEST AND LONGER LAKE FETCH IN EAST. W/ WINDS AND DEEP MIXED LAYER... WILL KEEP WITH ACCUMS WELL INLAND... INCLUDING ZONES 10/13/14. WITH EXPECTED SNOW AND WIND...TRAVEL WILL BECOME CERTAIN HAZARD ACROSS MUCH OF THE U P. WILL UPGRADE WATCH TO WARNING IN EAST HALF OF CWA. SEE BULLETS BELOW FOR HEADLINE DETAILS. JKL LONGER TERM SUN-FRI... VERY COMPLICATED HEADLINE FORECAST THIS WEEKEND WITH WINDING DOWN OF EVENT ON SAT THEN RESURGENCE OF LES AS 5H LOW NOW OVER NRN HUDSON BAY DROPS ALMOST DUE S TWD LK SUPERIOR SUN. VERY COLD AIR VCNTY NRN HUDSON BAY WITH MIDDAY SFC TEMPS RUNNING -10 TO -20F. MORE ON THE HEADLINES LATER. ON SAT...WORST OF EVENT WILL BE OVER BY MIDMORNING AS WINDS DIMINISH AND PURE LES REGIME TAKES OVER WITH SHARP DRYING DEPICTED AS INVERSION DROPS TO 3-5KFT (LOWEST W) PER ETA SOUNDINGS. ETA CONTINUES TO BE FASTEST WITH THE DRYING AND THIS MAY NOT BE UNREASONABLE GIVEN SFC OBS/VIS IMAGERY SHOWING RAPID CLEARING ACROSS MANITOBA. IF AS DRY AS DEPICTED...SHOULD SEE MULTIPLE WIND PARALLEL BANDS WITH FAIR AMOUNT OF SEPARATION BTWN THEM ON SAT. LONGER FETCH ACROSS ERN SUPERIOR INTO ALGER/LUCE/NRN SCHOOLCRAFT WILL PROVIDE FOR HEAVIEST SNOW THERE. A VARIETY OF SOLUTIONS DEVELOP SAT NIGHT/SUN WITH REGARD TO ARCTIC LOW DROPPING TWD LK SUPERIOR. NGM IS QUICKEST/FARTHEST W AND IS THE OUTLIER AS IT SHOWS 5H LOW NEAR CYQT SUN MORNING WITH -44C 5H COLD POOL CENTERED OVER LAKE SUPERIOR. LES CONVECTION WOULD BE VERY IMPRESSIVE IF THIS OCCURRED. CANADIAN/UKMET/GFS/ETA HAVE VARYING DEGREES OF A FARTHER E SOLUTION...BUT CONSENSUS WOULD BRING 5H LOW VERY CLOSE TO ERN LK SUPERIOR. 5H TEMPS PROGGED AT -40 TO -42C OVER ERN LK SUN MORNING...BUT ARE ABOUT 10C WARMER NEAR APOSTLE ISLANDS. APPROACH OF THIS 5H LOW AND COLD POOL TOWARD LAKES WILL RESULT IN DIFFICULT TO FCST LOW-LEVEL WIND FIELDS SAT NIGHT/EARLY SUN. EXPECTATION IS THAT A VERY SHARP SFC TROF WILL DEVELOP ACROSS THE LAKE WITH POTENTIALLY A STRONG LK INDUCED SFC LOW TAKING SHAPE SOMEWHERE IN THE TYPICAL LOCATION BTWN CARIBOU ISLAND/WHITEFISH POINT. ETA WIND FIELDS SUGGEST THIS...BUT NOT TO THE DEGREE THAT IS POSSIBLE. SO...WIND FIELDS MAY BACK DUE WRLY ACROSS FAR SRN LAKE AND POSSIBLY SW NEAR ALGER/LUCE SAT NIGHT. THIS WOULD PRODUCE ENHANCED CONVERGENCE FROM NRN ONTONAGON N THRU KEWEENAW SAT NIGHT...AND A DOMINANT OFFSHORE BAND WILL LIKELY DEVELOP FROM NEAR HURON ISLANDS EWD...WHICH DEPENDING ON WIND DIRECTION...COULD BRING VERY HEAVY LES TO SHORELINE LOCATIONS FROM PICTURED ROCKS EWD. THIS SEEMS LIKE THE MOST LIKELY SCENARIO...BUT THERE IS FAR TOO MUCH UNCERTAINTY IN HOW THIS WILL PLAY OUT. IF WINDS STAY MORE NW SAT NIGHT...MANY AREAS WILL GET IN ON INCREASINGLY HEAVY LES. SFC TROF AND OR LOW WILL DROP SE OF LK SUN. LES SHOULD BE ESPECIALLY INTENSE OVER ERN LK GIVEN VERY DEEP COLD AIRMASS. LAKE INDUCED CAPE OFF ETA FCST SOUNDING (SFC T/TD 16/12F) GOES TO AN UNHEARD OF 1600J/KG OVER ERN LAKE SUN. 70 PCT+ RH EXTENDING UP THRU 700MB (ETA/AVN) OVER ERN LAKE WILL ONLY MAKE LES MORE INTENSE. AIRMASS A LITTLE DRIER OVER WRN LAKE WITH DEPTH OF COLD AIR NOT AS SIGNIFICANT...BUT STILL GOOD FOR SIGNIFICANT SNOW. SO POTENTIAL THERE FOR VERY IMPRESSIVE SNOW TOTALS SUN (EASILY OVER A FOOT E). AS FOR THE COMPLICATED HEADLINE DECISIONS...HAVE TRIED TO KEEP THINGS SIMPLE WITH MAIN THREAT PERIODS HIGHLIGHTED. WARNINGS/ADVYS WILL BE IN EFFECT TONIGHT THRU SAT MORNING WEST/NW AND THRU SAT AFTN E. WATCHES WILL THEN GO UP FOR SAT NIGHT/SUN FOR ALL LK SUPERIOR COUNTIES. ALL WERE INCLUDED SAT NIGHT DUE TO CONSIDERABLE WIND DIRECTION UNCERTAINTY EVEN THOUGH EXPECTATION ATTM IS THAT ONLY NW AND NE COUNTIES WILL BE AFFECTED. WHEREVER SNOW BANDS DO GO ONSHORE THEY WILL BE VERY HVY. N WIND EXPECTED FOR AT LEAST PART OF SUN. TUE-FRI...PERSISTENT AMPLIFIED PATTERN OF RIDGE ALONG WRN NAMERICA AND TROF OVER ERN NAMERICA TO CONTINUE THROUGH THIS PERIOD. ONCE AGAIN...MODEL DIFFERENCES INVOLVE TIMING/POSITION OF SHORTWAVES AND ASSOCIATED SFC TROFS/LOWS DROPPING INTO ERN TROF. FIRST OF AT LEAST 2 SYSTEMS FOR NEXT WEEK ARRIVES TUE. GFS/ECMWF AND CANADIAN MODEL SHOW AN ASSOCIATED WEAK SFC LOW MOVING SOMEWHERE OVER THE UPPER LAKES WHILE UKMET JUST SHOWS A SFC TROF. WHETHER THERE IS A TROF OR A SFC LOW...END RESULT WILL BE THE SAME. EXPECT SOME -SN PRECEDING SHORTWAVE TUE...AND THEN LOW-LEVEL WINDS WILL SWITCH TO THE N... BRINGING ANOTHER ROUND OF LES TO THE LK SUPERIOR COUNTIES TUE NIGHT INTO EARLY WED AS 850MB TEMPS FALL BACK TO -15 TO -20C. HOWEVER... 12Z GFS HAS COMPLETELY BACKED OFF ON THIS SCENARIO WITH HIGH PRESSURE DOMINATING THE MIDWEEK PERIOD. NOT READY TO JUMP ON THIS JUST YET...BUT WILL LOWER POPS. IN ANY CASE...DESPITE MORE HIGH PRESSURE...IT WILL STILL BE MORE THAN COLD ENOUGH FOR PERSISTENT LES. LOW-LEVEL WINDS BECOME WRLY WED AHEAD OF NEXT SHORTWAVE DROPPING DOWN FROM NW CANADA. SO...ANOTHER ROUND OF SOME -SN WILL PRECEDE SYSTEM BY LATE WED WITH RENEWED LES AGAIN IN ITS WAKE LATE WED NIGHT/THU AS 850MB TEMPS FALL TWD -20C. FLOW BACKS THU NIGHT/FRI WITH POTENTIAL OF SOME WAA -SN. OBVIOUSLY...THIS WILL BE A COLD PERIOD. EXPECT TEMPS GENERALLY 10-15 DEGREES BLO NORMAL. ROLFSON .MQT...WINTER STORM WARNING THIS EVNG INTO SAT MORNING MIZ001>004-009-084. WINTER STORM WARNING LATE THIS EVNG THRU SAT MORNING MIZ005. WINTER STORM WARNING LATE THIS EVNG THRU SAT MIZ006-007-085. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY LATE THIS EVNG INTO SAT MORNING MIZ010. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY LATE THIS EVNG THRU SAT MIZ013-014. WINTER STORM WATCH SAT NIGHT AND SUN MIZ001>007-009-084-085. GALE WARNING LK SUPERIOR. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 350 PM CST FRI NOV 29 2002 TEMPERATURES WILL PRESENT THE MAIN FORECAST CHALLENGE IN THE SHORT FORECAST. CANADIAN COLD FRONT EDGING ITS WAY INTO NORTHWEST MISSOURI THIS AFTERNOON AND LIKELY WILL PUSH SOUTH OF I-70 IN THE 22 TO 23Z TIME PERIOD. REAL COLD PUSH WILL LAG THE FRONT BY SEVERAL HOURS...AS RUC AND ETA DO NOT SHOW MARKED THETAE PACKING MOVING INTO THE AREA UNTIL AFTER 06Z. SURFACE GRADIENT TIGHTENS UP AND AREA BROKEN STRATUS BEHIND PRIMARY COLD SURGE...THUS DO NOT EXPECT TEMPERATURES TO PLUMMET TOO MUCH. WITH SHEAR ZONE ARCING ACROSS NORTHEAST AND NORTHEAST CENTRAL ZONES...DECIDED TO THROUGH IN A MENTION OF FLURRIES FOR LATE TONIGHT INTO EARLY SATURDAY. STRONG COLD ADVECTION AND SOME STRATUS WILL KEEP TEMPERATURES CHILLY ON SATURDAY...AND CONTINUED TO TREND FORECAST TEMPERATURES SLIGHTLY DOWNWARD. CLOUDS EXIT THE AREA AND SURFACE GRADIENT WEAKENS SATURDAY NIGHT...BUT ETA/GFS/NGM ALL DEPICTING...S-SW SURFACE FLOW...25-30KT FLOW IN THE 925-950 LAYER AND PRONOUNCED WARM AIR ADVECTION ENSUING AFTER 06Z SUNDAY. DECIDED TO BUMP TEMPERATURES UP A COUPLE DEGREES ACROSS WESTERN ZONES GIVEN THIS SCENARIO. MODERATING AIRMASS AND WARM ADVECTION WILL GIVE TEMPERATURES A BOOST ON SUNDAY. WILL NOT RAISE TEMPERATURES TOO MUCH ACROSS EASTERN HALF OF FORECAST AREA...WHICH WILL REMAIN WELL EAST OF 925/850 RIDGES AXES...BUT A FEW LOCATIONS IN EXTREME WESTERN PART OF CWA MAY SEE 50. IN THE EXTENDED PORTION OF THE FORECAST...DEEP LAYER MOISTURE GRADUALLY INCREASES ON MONDAY IN ADVANCE OF UPSTREAM SHORT WAVE. FEEL CHANCES FOR RAIN SLIGHT ON MONDAY ACROSS MOST OF THE FORECAST AREA...AS THERE IS LITTLE IN THE WAY OF QG FORCING. SOME ISENTROPIC LIFT DURING THE MORNING ACROSS SOUTHERN MO...BUT NOT WORTH CARRYING SLIGHT CHANCE POPS. LOW LEVEL GRADIENT TIGHTENS IN ADVANCE OF SHORT WAVE AND ASSOCIATED TROUGH...THUS HAVE BUMPED TEMPERATURES A LITTLE FOR MONDAY. ALSO BROUGHT TEMPERATURES UP A LITTLE ON TUESDAY...THOUGH GFS SPREADS QUITE A BIT OF MOISTURE INTO THE AREA. NOT WILLING TO BUY WIDESPREAD LIGHT PRECIPITATION THAT THE GFS IS ADVERTISING...SO LEFT FORECAST DRY FOR NOW. FINALLY...INCREASED TEMPERATURES ON THURSDAY DUE TO EXPECTED DOWNSLOPE WARMING. SF/DB 1245 PM... PESKY CIRRUS PUTTING THE KABOSH ON TEMPERATURES TODAY...BASED ON LATEST TRENDS...DECIDED TO BACK OFF ON 60S ADVERTISED FOR SOUTHWEST AND SOUTHERN TIER OF ZONES. FEW LOCATIONS MAY REACH THE 60 DEGREE MARK...BUT CIRRUS REMAINS SUBSTANTIAL AND THERE AREA ONLY A COUPLE HOURS OF HEATING LEFT. ALSO ADJUSTED WINDS DOWNWARD...AS CIRRUS PREVENTING MIXING AND KEEPING WINDS AT OR BELOW 12KTS AHEAD OF FRONT. SF WINDS ACROSS CWA CURRENTLY STRENGTHENING AHD OF SFC FRNT. 40KTS RIGHT OFF THE DECK. THIS IS KEEPING TEMPERATURES FROM FALLING ANY SINCE ABOUT 03Z...EVEN RISING A DEG OR TWO SINCE THEN. MAIN CHALLENGE NEXT DAY OR TWO WILL BE TEMPS AND WINDS. ONCE WE MIX AND TAP INTO THE LAYERS ABV...WINDS SHOULD INCREASE AND TEMPS RISE RAPIDLY. SOME CONCERN WITH THE CIRRUS TO OUR WEST PUTTING A DAMPER ON THE WARMUP...SO HAVE MADE ALLOWANCES FOR THAT. STILL HAVE GONE RIGHT AROUND MAV GUID. GRADUAL WIND SHIFT WITH THE FRONT...WITH WIND SPEEDS HIGHER BEHIND IT. IN FACT...SHOULD SEE BREEZY CONDITIONS LAST THROUGH MOST OF THE NIGHT. WITH WINDS STAYING UP AND SCT CLOUDS...OVERNIGHT LOWS SHOULD NOT TAKE THE BIG DROP UNTIL SATURDAY NIGHT. THE AVN TRIES TO BRING SOME QPF INTO NERN MO TONIGHT...BUT FEEL WITH MOISTURE PROFILES WE WILL BE LUCKY TO SEE MUCH OF A CLOUD DECK. GOOD CAA AND BREEZY NW WINDS ON SAT...HIGHS WILL STRUGGLE TO HIT 40. AS SFC RIDGE PASSES TO OUR SOUTH...THAT LULL AS THE WINDS TURN SHOULD BE ENOUGH TO RADIATE OUT INTO THE TEENS. TEMPS WILL WARM BACK TO NEAR NORMAL FOR SUNDAY BEFORE THE NEXT ITEM OF INTEREST ON MONDAY. SHRTWV WANDERS IN FROM THE 4 CORNERS REGION...BUT AS HAS BEEN THE CASE FOR THE LAST SEVERAL WEEKS...MOISTURE IS IN QUESTION. WILL LEAVE SCHC POPS AS IS. NO OTHER CHANGES MADE. LVQ .EAX... KS...NONE. MO...NONE. mo AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NORTH PLATTE NE 838 PM CST FRI NOV 29 2002 UPDATED ZFP AND NPW WILL BE OUT BY AROUND 9 PM TO TRIM BACK ON WIND ADV AREA. WINDS AT VTN AND BBW HAVE DIMINISHED WELL BELOW ADVISORY CRITERIA...FOR NOW. WINDS WILL LIKELY PICK UP AGAIN SOON AS SECONDARY COLD FRONT SWINGS WITH ASSOCIATED STRONG PRESSURE RISES. WINDS WILL MOST LIKELY STAY BELOW ADV CRITERIA AS THE RUC AND 18Z ETA BOTH SHOW THE STRONGEST 850MB CAA STAYING EAST OF THESE AREAS AND BEST 3HR PRES RISES WELL EAST OF THE AREA. SO WILL BE DROPPING ADV FOR CHERRY LOGAN THOMAS AND CUSTER COUNTIES BUT KEEP WIND ADV GOING FOR KEYA PAHA BROWN AND BLAINE COUNTIES EASTWARD. WINDS OVER EASTERN SOUTH DAKOTA REALLY RESPONDING NICELY WITH STRONG PRESSURE RISES OF 5-6MB OVER THE LAST 2 HOURS WITH GUSTS OVER 50 WITH THE INITIAL SURGE. WIND DROP OFF NICELY BEHIND THE INTIAL SURGE SO WINDS SHOULD TAPER OFF OVER MOST OF THE ADVISORY AREA AFTER MIDNIGHT. .LBF...WIND ADVISORY UNTIL MIDNIGHT KEYA PAHA ROCK BROWN BLAINE AND LOUP COUNTIES. WIND ADVISORY TONIGHT FOR BOYD HOLT GARFIELD AND WHEELER COUNTIES. IZZI PREVIOUS DISCUSSION FOLLOWS... ...FORECAST CHALLENGES WITH THIS CYCLE ARE FIRST PERIOD WIND AND TEMPERATURES IN LATER PERIODS... ...18Z SYNOPSIS... SURFACE ANALYSIS WAS CHARACTERIZED BY THE PRESENCE OF TWO FRONTS. ONE WAS PASSING THROUGH SOUTHERN NEBRASKA. TEMPERATURES BEHIND THAT ONE HAD PEAKED OVER MOST OF THE NORTH PLATTE FORECAST AREA. ANOTHER FRONT WITH MUCH COLDER TEMPERATURES WAS DRAPED ACROSS NORTHERN MINNESOTA AND NORTHERN NORTH DAKOTA. IN THE UPPER LEVELS, THE 6.7U IMAGERY SHOWED DARKENING WITH A BAROCLINIC ZONE ACROSS CENTRAL MINNESOTA AND NORTHERN SOUTH DAKOTA. ...FORECAST THROUGH DAY 4... THE ETA AND GFS ARE SIMILAR TO 84 HOURS, AND THE 12Z GFS CONTINUES TO INDICATE A LESS PROGRESSIVE PATTERN THAN THE 00Z RUN. CONFIDENCE IS FAIRLY HIGH IN A BLEND OF THE TWO THROUGH DAY 4. STRONG WIND WILL CONTINUE THROUGH LATE THIS EVENING OVER THE CURRENT WIND ADVISORY AREA UNTIL LATE EVENING. I WILL ADD THOMAS, LOGAN, AND CUSTER COUNTIES TO THE ADVISORY FOR THIS EVENING. THEN, THE GRADIENT WILL WEAKEN ENOUGH FOR THE WIND TO FALL BELOW ADVISORY THRESHOLDS. THE WIND WILL THEN CONTINUE TO DIMINISH, SO THAT IT IS NOT EXPECTED TO BE A PROBLEM SATURDAY, THOUGH BREEZY TO WINDY CONDITIONS WILL CONTINUE IN THE EASTERN PART OF THE FORECAST AREA. SOME LAST MINUTE MODIFICATIONS MAY BE REQUIRED BASED ON 21Z OBSERVATIONS. DESPITE SIGNIFICANT FORCING TONIGHT WITH LOW LEVEL CONVERGENCE, ELEVATED 2D-FRONTOGENESIS, AND 700-500MB DCVA, MOISTURE IS LACKING. SO, NO MEASURABLE PRECIPITATION IS EXPECTED. AS THE SECOND FRONT PASSES, WIND SHOULD KEEP TEMPERATURES UP TONIGHT. THE STRONGEST COLD ADVECTION WITH THIS FRONT WILL BE IN THE NORTHEAST AND EAST PART OF THE NORTH PLATTE FORECAST AREA, THOUGH, EVEN IN THE WEST, A SIGNIFICANT CHANGE IS EXPECTED. FOR SATURDAY, THE 24 HOUR TEMPERATURE CHANGE INDICATES 8-15F DECREASES WEST TO EAST. FOR SUNDAY, INCREASES OF 4-12F ARE EXPECTED NORTHEAST TO SOUTHWEST. ...FORECAST DAYS 5-7... LAST NIGHT'S GFS INDICATES A MORE PERSISTENT UPPER RIDGE CONTINUING ALONG THE PACIFIC COAST INTO EASTERN ALASKA. THIS WOULD FAVOR MORE PERSISTENT COLD THAN THE PREVIOUS MEDIUM RANGE GFS WAS INDICATING. CONSIDERING THE CURRENT BLOCKY PATTERN, I WOULD FAVOR A LESS PROGRESSIVE SOLUTION THAN THE ECMWF INDICATES. SO, THOUGH MY CONFIDENCE IN THE GFS BEYOND 120 HOURS IS NOT HIGH, IT DOES SEEM TO BE A MORE REASONABLE SOLUTION THAN THE ECMWF. ALSO, THE PERSISTENT NORTH TO NORTHWEST FLOW WOULD PROBABLY BAR SIGNIFICANT PRECIPITATION. SO, FOR NOW, I WILL KEEP IT DRY WEDNESDAY THROUGH FRIDAY. SPRINGER ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 1024 PM EST FRI NOV 29 2002 WINDS HAVE BEEN SLOW TO SUBSIDE THIS EVENING. THE 18Z MESOETA SUGGESTS THAT DECREASING SPEEDS BEGINNING AROUND NOW THROUGH THE NIGHT. TEMPERATURES HAVE WARMED INTO THE LOW TO MID 40S IN THE WEST THIS EVENING. TEMPS REMAIN IN THE UPPER 30S EAST OF LAKE ONTARIO AND IN OSWEGO COUNTY WITH PCPN CHANGING BACK TO RAIN. FIRST PERIOD ADJUSTMENTS EWRE MADE FOR TEMPS AND WINDS...AND TO TIME END OF LIGHT PCPN FROM WEST TO EAST. FCST MAXS WERE RAISED A BIT FOR SATURDAY TO MESH WITH TONIGHTS WARMER READINGS. PREVIOUS AFD BELOW ....... WINDS HAVE SUBSIDED BELOW ADVISORY CRITERIA SO WILL LET WIND ADVISORY WILL EXPIRE WITH THIS PACKAGE. RADAR SHOWS PRECIPITATION MOVING OUT BUT BOTH ETA AND RUC MODELS SHOW IT LINGERING EAST OF LAKE ONTARIO WHERE WE WILL KEEP LIKELY POPS OVERNIGHT. PRECIPITATION TYPE IS PROBLEM EAST OF LAKE ONTARIO, AND WE HAVE FOLLOWED THE ETA BUFKIT TEMPERATURE GUIDANCE AND STARTED WITH A MIX AND CHANGING TO RAIN OVERNIGHT. LIKEWISE ON SATURDAY WE WILL START WITH RAIN, CHANGE TO SNOW IN THE WEST IN THE LATE MORNING, IN THE MID AFTERNOON OR LATER FROM ROCHESTER EAST AND MID DAY EAST OF LAKE ONTARIO. BOTH THE ETA AND RUC SHOW LAKE EFFECT DEVELOPING OFF LAKE ERIE LATE MORNING WITH THE RUC KEEPING IT ACROSS THE SOUTHERN TIER, BUT THE ETA PUSHING IT UP INTO WYOMING AND SOUTHERN ERIE COUNTY. WITH SHIFTING WINDS FOLLOWING THE FRONT, THE RUC IS MORE BELIEVABLE SO WE WILL HOIST A LAKE EFFECT SNOW WATCH ACROSS THE SOUTHERN TIER FOR SATURDAY. THE EVENT SHOULD BE SHORT ENOUGH TO STAY BELOW WARNING CRITERIA OF 7 INCHES. VERY COLD AIR MOVES IN BEHIND THE FRONT IN THE NORTHWEST FLOW SATURDAY NIGHT, AND WITH THE UPPER TROUGH STILL AROUND IN THE EVENING, SNOW SHOWERS ARE LIKELY EVERYWHERE, BUT WITH WIND SHEAR, WE DON'T EXPECT SIGNIFICANT LAKE SNOWS. THE WINDS BACK TO THE SOUTHWEST ON SUNDAY WITH MORE SIGNIFICANT LAKE SNOWS LIKELY OFF LAKE ERIE. THE LAKE SNOWS SHOULD HOLD OFF UNTIL EVENING OFF LAKE ONTARIO. .BUF...LAKE EFFECT SNOW WATCH FOR SATURDAY NYZ019-020 APB ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 330 PM EST FRI NOV 29 2002 WINDS HAVE SUBSIDED BELOW ADVISORY CRITERIA SO WILL LET WIND ADVISORY WILL EXPIRE WITH THIS PACKAGE. RADAR SHOWS PRECIPITATION MOVING OUT BUT BOTH ETA AND RUC MODELS SHOW IT LINGERING EAST OF LAKE ONTARIO WHERE WE WILL KEEP LIKELY POPS OVERNIGHT. PRECIPITATION TYPE IS PROBLEM EAST OF LAKE ONTARIO, AND WE HAVE FOLLOWED THE ETA BUFKIT TEMPERATURE GUIDANCE AND STARTED WITH A MIX AND CHANGING TO RAIN OVERNIGHT. LIKEWISE ON SATURDAY WE WILL START WITH RAIN, CHANGE TO SNOW IN THE WEST IN THE LATE MORNING, IN THE MID AFTERNOON OR LATER FROM ROCHESTER EAST AND MID DAY EAST OF LAKE ONTARIO. BOTH THE ETA AND RUC SHOW LAKE EFFECT DEVELOPING OFF LAKE ERIE LATE MORNING WITH THE RUC KEEPING IT ACROSS THE SOUTHERN TIER, BUT THE ETA PUSHING IT UP INTO WYOMING AND SOUTHERN ERIE COUNTY. WITH SHIFTING WINDS FOLLOWING THE FRONT, THE RUC IS MORE BELIEVABLE SO WE WILL HOIST A LAKE EFFECT SNOW WATCH ACROSS THE SOUTHERN TIER FOR SATURDAY. THE EVENT SHOULD BE SHORT ENOUGH TO STAY BELOW WARNING CRITERIA OF 7 INCHES. VERY COLD AIR MOVES IN BEHIND THE FRONT IN THE NORTHWEST FLOW SATURDAY NIGHT, AND WITH THE UPPER TROUGH STILL AROUND IN THE EVENING, SNOW SHOWERS ARE LIKELY EVERYWHERE, BUT WITH WIND SHEAR, WE DON'T EXPECT SIGNIFICANT LAKE SNOWS. THE WINDS BACK TO THE SOUTHWEST ON SUNDAY WITH MORE SIGNIFICANT LAKE SNOWS LIKELY OFF LAKE ERIE. THE LAKE SNOWS SHOULD HOLD OFF UNTIL EVENING OFF LAKE ONTARIO. .BUF...LAKE EFFECT SNOW WATCH FOR SATURDAY NYZ019-020 APB ny AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 1000 AM MST FRI NOV 29 2002 CURRENT SURFACE MAP HAS LOW PRESSURE JUST NORTH OF LAKE SUPERIOR...WITH 14MB PRESSURE GRADIENT ACROSS FORECAST AREA. WINDS APPROACHING HIGH WIND CRITERIA ACROSS NORTHWEST SOUTH DAKOTA. COLD FRONT NOW SLIDING THROUGH NORTH DAKOTA...AND WILL BACK INTO WESTERN SOUTH DAKOTA LATER THIS AFTERNOON. NOT A CLASSIC SET UP FOR HIGH WINDS AS BEST PRESSURE RISES/SUBSIDENCE WILL SLIDE EAST OF THE FORECAST AREA VS. COMING STRAIGHT AT US FROM THE NORTHWEST. 12Z ETA/RUC HAVE ALSO DROPPED 850MB WIND FORECAST BY 5-10 KNOTS ACROSS THE WESTERN PART OF THE WARNING AREA. WITH THE SURFACE WINDS HAVING MORE OF A WESTERLY COMPONENT...WILL BE A LITTLE HARDER TO GET THE HIGH WINDS IN RAPID CITY. OVERALL...WINDS WILL BE IN THE UPPER END OF ADVISORY CRITERIA...WITH HIGH WIND WARNING HAVING A BETTER CHANCE VERIFYING ON SUSTAINED WINDS THAN THE WIND GUSTS. UPDATED FORECAST TO DROP HIGHS SLIGHTLY. .UNR...HIGH WIND WARNING NORTHWEST SD TODAY. WIND ADVISORY SOUTH CENTRAL SD THIS AFTERNOON AND EVENING. 07 sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 120 PM CST FRI NOV 29 2002 LARGE SCALE 500 MB 5 DAY MEANS CONTINUE TO SHOW A STRONG NEGATIVE ANOMALY OVER SOUTHEASTERN CANADA. THIS STRENGTHENS AND RETROGRADES DURING THE 10 DAY PERIOD. MAIN FORECAST CHALLENGES ARE THE WINDS TONIGHT AND SATURDAY...THEN THE AFFECT THIS SMALL PATTERN RETROGRESSION WILL HAVE ON THE TRACK OF SYSTEMS MOVING THROUGH THE REGION /WHICH HAS BEEN NORTHEAST OF THE FORECAST AREA TO DATE/. WATER VAPOR IMAGERY LOOP SHOWING STRONG SUBSIDENCE /NOTED BY THE DARKENING/ MOVING INTO SOUTHERN MINNESOTA/WISCONSIN. PROFILER/UPPER AIR DATA AS WELL AS RUC/ETA/GFS SUGGEST A STRONG 850 WIND MAX IN EXCESS OF 50 KNOTS DROPPING DOWN THROUGH THE FORECAST AREA THIS AFTERNOON AND CONTINUING TONIGHT. THESE FEATURES SHOULD WORK TOGETHER TO INCREASE WIND THREAT THIS AFTERNOON. THESE CONDITIONS WILL CONTINUE TONIGHT. ETA/RUC FORECAST OF LOW LEVEL LAPSE RATES EXCEEDS 7 C/KM. THIS WOULD SUGGEST A WELL MIXED ATMOSPHERE...ENOUGH TO CONTINUE THE TRANSPORT OF THE STRONG WINDS ALOFT DOWN TO THE SURFACE. THIS COULD LAST THROUGHOUT MUCH OF THE NIGHT. AS A RESULT...WE HAVE ISSUED A WIND ADVISORY FOR THE FLAT AREAS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. COLD AIR COMES IN TONIGHT...BUT MUCH SLOWER THAN THE ETA/GFS SUGGESTED THURSDAY. THIS MORNINGS RUNS SHOW THE COLD ADVECTION DELAYED UNTIL 03Z. THIS SEEMS REASONABLE GIVEN THAT THE COLD FRONT IS ACROSS NORTHERN MINNESOTA AT 18Z. AS FOR TEMPERATURES WITH THIS COLD AIR OUTBREAK...VERIFICATION UNDER THIS PATTERN SHOWS A 2 DEGREE COLD BIAS WITH THE NGM MOS...A 4 DEGREE COLD BIAS WITH THE GFS MOS...AND A 1 DEGREE WARM BIAS WITH THE ETA MOS. SEE NO REASON THAT IT WILL CHANGE. I THINK IT WILL BE VERY DIFFICULT TO REACH THE PROJECTED LOWS IN THE SINGLE DIGITS WITHOUT SNOW ON THE GROUND. AS A RESULT...HAVE FORECAST TEMPERATURES CLOSER TO THE WARMER ETA MOS. THIS IS CARRIED INTO THE DAYTIME HIGHS AS WELL. AS PREVIOUSLY MENTIONED...THE UPPER LEVEL PATTERN WILL RETROGRADE A BIT AS DISTURBANCES CONTINUE TO CARVE OUT THE WESTERN SIDE OF THE UPPER LEVEL LOW. THE ETA/GFS AGREE WITH THIS SCENARIO. THIS WOULD RESULT THE PATH OF DISTURBANCES /WHICH UP UNTIL THIS POINT HAS BEEN NORTHEAST OF THE FORECAST AREA/ MOVING WESTWARD AND INCREASING THE LIKELIHOOD OF SOME SNOW ACROSS THE FORECAST AREA. THIS MANIFESTS ITSELF ON MONDAY...AS THE ETA FORECASTS A DISTURBANCE TO MOVE THROUGH THE FORECAST AREA. THE 00Z GFS...WHICH LOOKS VERY SIMILAR TO THE 12Z ETA...ALSO AGREES WITH THIS. THIS GFS ALSO BRINGS ANOTHER SYSTEM THROUGH NEXT WEEKEND WHICH COULD ALSO BRING SOME ADDITIONAL SNOWFALL. IF THIS SNOW OCCURS...THE TEMPERATURE FORECASTS WILL HAVE TO ADJUSTED DOWNWARD. FOR NOW...LEFT MAINLY A PERSISTENCE FORECAST. INTERSITE GRIDS OFFICIAL. .LSE...WIND ADVISORY FOR TONIGHT... IAZ008>010-018-019-029-MNZ086-087-094-095. KRC wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 151 AM CST SAT NOV 30 2002 MAIN FORECAST CHALLENGE IS CLOUD COVER AND TEMPS TODAY. SURFACE CHART AT 06Z SHOWED A STRONG COLD FRONT POSITIONED FROM THE NORTHERN PARTS OF LAKE MICHIGAN SOUTHWEST TO THE IA/MO BORDER THEN WEST INTO SOUTHERN NE. A RELATIVELY NARROW AREA OF POST-FRONTAL MVRF STRATO-CU WAS NOTED ALONG WITH A FEW OBS SHOWING -SN. A SURFACE TROUGH WAS POSITIONED ACROSS THE FORECAST AREA FROM NE TO SW AND EXTENDED FURTHER SW INTO NE TX WHERE A WEAK SURFACE LOW HAS DEVELOPED. A PSEUDO WARM FRONT WAS POSITIONED FROM NEAR KLIT SE TO KMOB. GOOD GULF MOISTURE RETURN HAS ESTABLISHED SW OF THIS LINE AND SE OF THE TX SURFACE LOW. THE AVN/NGM ARE OVERDOING THE AMOUNT OF POST-FRONTAL LOW LEVEL MOISTURE. THE MESOETA AND RUC HAS A MUCH BETTER HANDLE ON THE AMOUNTS AND WILL FOLLOW THEIR CLOUD SOLUTIONS FOR TODAY. THIS WILL MEAN SOME TEMPORARY MORNING STRATO-CU CIGS ACROSS NORTHEAST PARTS OF THE AREA WITH SOME SCATTERED STRATO-CU ELSEWHERE. ANY FLURRIES AMONG THESE CLOUDS WILL BE FEW AT BEST WITH LITTLE DURATION. AS SUCH WILL CONTINUE WITH A PRECIP-FREE FORECAST. NOWCASTS SHOULD BE ABLE TO HANDLE ANY THAT DO MOVE INTO THE AREA. A JET-STREAK CURRENTLY PASSING ACROSS THE SOUTHERN HALF OF KS IS PRODUCING SOME ENHANCED CI. NONE OF THE MODELS SEEM TO BE PICKING UP ON THIS FEATURE. ITS TRAJECTORY SHOULD TAKE THESE CLOUDS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA THIS MORNING PRIOR TO THE ARRIVAL OF THE STRONGER 130+ KT NORTHERN BRANCH OF THE JET WHICH WILL PUSH THE CI SOUTH OF THE AREA BY MID-DAY. HIGH TEMPERATURES TODAY...ESPECIALLY IN NORTHWEST PARTS OF THE AREA...MAY BE THE 12Z READINGS GIVEN THE STRONG POST-FRONTAL COLD AIR ADVECTION ADVERTISED FOR TODAY. THE FROPA TIME WINDOW ACROSS THE AREA BASED UPON AN AWIPS DISTANCE/SPEED FUNCTION LOOKS TO BE AROUND 1500Z NORTHWEST AND 1630Z SOUTHEAST. THE RUC SEEMS TO BE IN GOOD ALIGNMENT WITH THIS MEASUREMENT SO WILL MAKE USE OF ITS EARLY MORNING TEMPS FOR HIGHS. THAT WOULD BE LOWER 40S NORTHWEST TO MID 40S SOUTHEAST. TEMPERATURES THEN FALL INTO THE MID TO UPPER 30S BY THE AFTERNOON. BRISK NORTHWEST WINDS OF 15 TO 25 MPH STILL LOOK PROMISING TODAY...ESPECIALLY ACROSS NORTHEAST PARTS OF THE AREA. HIGH PRESSURE WILL QUICKLY MOVE INTO THE AREA BY TONIGHT WITH ITS AXIS SHIFTING EAST OF THE AREA AROUND MIDNIGHT. THIS WILL RESULT IN WINDS WEAKENING BUT BECOMING SOUTHWEST. LATEST GUIDANCE STILL HAS EXPECTED LOWS TONIGHT AROUND 20. RECORD LOW FOR KPAH IS 17. WILL INCLUDE /NEAR RECORD LOW/ WORDING FOR ITS ZONE. THE RECORD FOR KEVV IS 12 SO WILL NOT ADD NEAR RECORD WORDING. THE REMAINDER OF THE FORECAST STILL LOOKS ON TRACK. THE BIGGEST QUESTION HOWEVER REMAINS PRECIP CHANCES TUESDAY. THE AREA LOOKS TO BE BETWEEN SYSTEMS...OVERRIDING PRECIP TO OUR SOUTH AND PRECIP ASSOCIATED WITH A SHORT WAVE TROUGH AND ASSOCIATED COLD FRONT APPROACHING FROM THE NORTHWEST. GUIDANCE STILL SUGGEST THE AREA WILL MISS THE BULK OF THE PRECIP FROM BOTH OF THESE SYSTEMS. CURRENT CCF 30/40 POPS FOR RAIN ON TUESDAY STILL LOOK LIKE A GOOD CALL FOR OUR AREA. .PAH...NONE. DFS ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 300 AM EST SAT NOV 30 2002 LET THE ROLLER COASTER RIDE BEGIN. BAND OF MID LEVEL CLOUDINESS HAS MOVED INTO THE NORTHERN HALF OF THE FORECAST AREA AT THIS TIME. DESPITE A FEW RADAR RETURNS...NO SPRINKLES ARE FALLING...AND THUS IT APPEARS THE LOWER LEVELS ARE JUST TOO DRY FOR ANY PRECIP TO HIT THE GROUND. THE REAL COLD FRONT WAS STILL TO WELL TO THE NORTHWEST...EXTENDING FROM NEBRASKA THROUGH IOWA AND INTO MICHIGAN...NEAR THE 530 THICKNESS PACKING AS NOTED BY THE LATEST RUC MODEL. THERE WILL LIKELY BE A BRIEF CLEARING EARLY THIS MORNING AHEAD OF SAID COLD FRONT BEFORE THE LOWER LEVEL MOISTURE MOVES IN FROM NORTH TO SOUTH. TEMPERATURES WILL BE STEADY OR MAY EVEN RISE A DEGREE OR TWO EARLY THIS MORNING AFTER SUNRISE UNTIL THE FRONT ARRIVES IN THE NORTHERN FORECAST AREA BY 15Z OR SO...THEN THE TEMPERATURES WILL BEGIN THEIR DOWNWARD SPIRAL. MESO ETA BUFKIT SOUNDINGS INDICATE BY MID MORNING THAT MIXING BECOMES OF SUFFICIENT DEPTH THAT SUSTAINED WESTERLY WINDS OF 15 TO 25 MPH WILL BE COMPLEMENTED WITH GUSTS TO 35 MPH ACROSS NORTH CENTRAL KENTUCKY AND GUSTS TO 30 MPH ACROSS EAST CENTRAL KENTUCKY. GUSTS OF 25 TO 30 LOOK ON TARGET FURTHER SOUTH ACROSS SOUTHERN LOCALES. OVERALL...MAY USE WINDY WORDING ACROSS THE NORTH AND BREEZY ACROSS THE SOUTH. WITH REGARD TO PRECIPITATION TODAY...THE SHORT WAVE VORT MAX IS PROGGED TO MOVE ON A TRACK FROM HUNTINGBURG TO LOUISVILLE TO LEXINGTON...THUS THE BEST CHANCE FOR ANY PRECIPITATION WOULD BE ALONG AND NORTH OF THAT TRACK. THUS...WE FEEL THAT THERE MAY BE A STRAY FLURRY FOR THOSE AREAS...BUT ESPECIALLY FOR EAST CENTRAL KENTUCKY WHERE THE BUFKIT SOUNDINGS INDICATE THE MOISTURE APPEARS TO BE A LITTLE LESS SHALLOW. THE MEASURABLE SNOW WILL REMAIN NORTHEAST OF THE FORECAST AREA. THE MOISTURE BEGINS TO DEPART FROM WEST TO EAST OVERNIGHT...AND WILL OPT FOR A DECREASING CLOUD TREND...BUT MAY STILL HAVE TO HOLD ONTO A CHANCE OF FLURRIES IN THE EVENING ACROSS EAST CENTRAL KENTUCKY AS MOISTURE IS SLOWEST TO DEPART THAT REGION. WINDS SHOULD SLOWLY DIMINISH OVERNIGHT WITH MUCH COLDER TEMPERATURES ON TAP. BASED ON TRAJECTORY FORECASTS OF CURRENT TEMPERATURES BEHIND THE FRONT...LOWS IN THE 18 TO 22 DEGREE RANGE LOOK GOOD FOR NOW. THROUGH THE REST OF THE FORECAST...RIDGE OF HIGH PRESSURE WILL BUILD THROUGH THE SOUTHERN COASTAL REGION WITH A FRONTAL BOUNDARY SETTLING INTO THE FORECAST AREA MONDAY AND REMAINING STATIONARY AS LOW PRESSURE THEN DEVELOPS AND SWEEPS IT EASTWARD TUESDAY. LOOKS LIKE ANOTHER SHOT OF COLD AIR IN STORE FOR LATE NEXT WEEK WITH LOWS DIPPING INTO THE 20S ONCE AGAIN AND HIGHS ONLY IN THE 30S. .SDF...NONE $$ VLD ky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ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 307 AM EST SAT NOV 30 2002 STORM SYS TO MOVE ACRS QUE TODAY AND INTO ME TONITE...THEN ACRS THE CANADIAN MARITIMES ON SUN. THIS SYSTEM/S ASSOCIATED CF TO SWEEP ACRS THE GREAT LKS REGION AND INTO THE ST LAW VLY TODAY. CFROPA EXPECTED ACRS THE FA TONITE. SECONDARY TROF TO MOVE ACRS THE FA ON SUN NITE AND MON. HI PRESS TO BUILD ACRS THE GREAT LKS REGION ON MON/MON NITE...AND THEN ACRS THE FA ON TUE/TUE NITE. NEXT STORM SYS LOOKS TO MOVE WELL THE THE SOUTH OF THE FA ON TUE/WED. S/W (AS SEEN IN H2O VAP IMAGERY) TO MOVE ACRS THE FA EARLY TODAY FROM THE WEST. ANOTHER S/W TO MOVE ACRS THE FA ON WED. 03Z 20KM "DEVELOPMENT" RUC SHOWS S-SW SFC WINDS AT 5-10 KTS TODAY. T1MAX TEMPS ARE 35-40F TODAY. THIS RANGE SHOULD BE PRETTY CLOSE TO REALITY TODAY. RUC SHOWS MOSTLY SN IN THE MTNS AND RA IN THE VLYS TODAY ACRS THE FA (BEST CHCS ACRS THE WRN ZONES BY LATER TODAY) UNDER MOCLDY SKIES. PW VALUES TO DROP TO AOB 0.3" ACRS THE FA TODAY AND TONITE...THEN BE BLO 0.2" ON SUN. H85 CAA TO TAKE PLACE ACRS THE FA TODAY THRU SUN...THEN WAA FOR SUN NITE AND MON. H85 TEMPS TO STAY BLO 0C ACRS THE FA DURING THE SHORT-TERM PERIOD. H925 WET-BULB TEMPS TO BE AT THEIR WARMEST TODAY (AOB 0C) ACRS THE FA. PLENTY OF LOW-LVL MSTR TO AFFECT THE FA TODAY THRU MON NITE AND THEN AGAIN ON WED. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA TONITE AND ON SUN. MID-LVL LAPSE RATES TO BE HI ACRS THE FA TODAY AND TONITE. SOME MID-LVL MSTR TO AFFECT THE FA TODAY THRU AT LEAST MON. BUFCAN/88D MOSAIC SHOWS SCT PCPN ACRS THE FA AND JUST UPSTREAM OF THE FA ATTM. RUC P-TYPE SCENARIO LOOKS LIKE A GOOD IDEA FOR THE TODAY PERIOD WITH THE ST LAW VLY SEEING MOSTLY LIQUID PCPN BASED ON CURRENT TEMPS/DEWPTS OUT THERE. DECENT WINDEX PARAMETERS ACRS THE FA TONITE (WITH HI INSTABILITY...A DECENT AIRMASS CHANGE AND WIND SHIFT...AS WELL AS PLENTY OF LOW-LVL MSTR) SHOULD JUSTIFY THE LIKELY SHSN WORDING FROM THE PREVIOUS FCST FOR THEN. PREVIOUS FCST ALSO HAS A GOOD HANDLE ON SOME LINGERING EXPECTED -SHSN ACRS THE FA ON SUN AND AT LEAST INTO SUN NITE. WILL TREND TOWARDS SOME MORE CLDS ACRS THE FA ON MON (WITH TROF PASSAGE THEN) AND HAVE ELIMINATED THE MENTION OF PCPN ACRS THE FA ON TUE (BASED ON EXPECTED STORM TRACK THEN). HIR TRRN MAY JUST BRUSH ADVISORY CRITERIA (4" OF SN) OVER THE NEXT 24 HRS...BUT FEEL THAT IT WON/T BE OVER A WIDE ENUFF AREA TO WARRANT RAISING AN ADVISORY ATTM. TEMPS NOT EXPECTED TO GO MUCH OF ANYWHERE ON SUN ACRS THE FA...SO WILL CONT THE MENTION OF "TEMPERATURES" INSTEAD OF HIGHS FOR THEN. NO CHANGES TO WED THRU FRI FCST FOR NOW. WRK ZONES OUT UNDER ALBWRKCWF. FINAL ZFP BY 4 AM. .BTV...NONE. MURRAY vt SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1050 AM EST SAT NOV 30 2002 12Z RAOBS/WATER VAPOR LOOP SHOW UPPER TROUGH AXIS OVER THE GREAT LAKES...WITH MAIN SHORTWAVE OVER THE OHIO VALLEY WITH A +150KT 300MB JET. SURFACE ANALYSIS SHOWS COLD FRONT JUST CLEARING FAR SOUTHEAST MICHIGAN...WITH TIGHT CYCLONIC FLOW ACROSS THE REGION BACK TO HIGH OVER THE DAKOTAS. DTX RADAR/METARS SHOW SNOW BEGINNING TO WEAKEN/TAPER OFF ACROSS THE NORTHERN CWA. LAKE EFFECT BANDS SETTING UP UPSTREAM APPARENT ON GRR/APX RADARS. MAIN FORECAST CONCERN IS WITH SNOW COVERAGE/AMOUNTS FOR THE AFTERNOON. SURFACE FRONT IS THROUGH THE CWA...WITH ALL STATIONS HAVING CHANGED OVER TO SNOW. MAIN PRECIP IS FOCUSED FARTHER UPSTREAM...MORE ALONG THE 850MB OR EVEN 700MB FRONTS. BACK EDGE/WEAKER ECHOES APPARENT ON APX RADAR AND BEGINNING TO BE PICKED UP ON DTX RADAR. HOWEVER MULTI-BAND SNOW SHOWERS ARE MAKING IT ACROSS NORTHERN LOWER TOWARD SOUTHEAST MICHIGAN. NOT QUITE PURE LAKE EFFECT...MORE ENHANCED WITH BROAD 850-500MB QVECTOR CONVERGENCE AND DEEP CYCLONIC FLOW. OBSERVED/FORECAST SOUNDINGS SHOW PLENTY OF MOISTURE THROUGH THE COLUMN...WITH INVERSION NEAR 12KFT. 12Z RUC/ETA ARE SIMILAR IN STRIPPING AWAY MID/UPPER MOISTURE LATE THIS AFTERNOON/BY EVENING. DESPITE WEAKENING SYNOPTIC SUPPORT...BELIEVE THAT MOST AREAS WILL STILL SEE SOME SNOW SHOWERS DURING THE AFTERNOON. WILL CONTINUE WITH CATEGORICAL POPS...WITH ONLY LITTLE ADDITIONAL ACCUMULATION. AS FOR LAKE HURON ENHANCEMENT CHANCES ACROSS THE THUMB...FLOW IS PRETTY MUCH NORTHWESTERLY ACROSS THE NORTHERN CWA. WIND FIELD MAY WAVER A BIT TO A MORE NORTHERLY DIRECTION...NOT MUCH MORE THAN 340/350 DEGREES. THIS WOULD STILL KEEP THE MAIN LAKE-ENHANCED SNOW OFFSHORE...HOWEVER WOULD COULD SEE SOME SNOW SHOWERS BRUSHING ACROSS FAR EASTERN HURON COUNTY. AFTERNOON TEMPERATURES ARE ANOTHER CONCERN AS COLD ADVECTION CONTINUES ACROSS THE REGION. 12Z RUC A BIT FASTER WITH THE COLD AIR THAN THE ETA...BUT BOTH STILL BRING -15C 850MB ISOTHERM INTO THE SAGINAW VALLEY BY 00Z THIS EVENING. WITH THICK CLOUD COVER/ADDITIONAL SNOW AND CONTINUED COLD ADVECTION...EXPECT TEMPERATURES STEADY OR SLOWLY FALLING THROUGH THE AFTERNOON. WINDS ARE ALSO AN ISSUE. INITIAL STRONG/GUSTY WINDS ALONG THE SURFACE FRONT WEAKENED EARLY IN THE DAY...BUT HAVE BEGUN TO PICK UP OVER THE LAST HOUR. 12Z SOUNDINGS/CURRENT VWP SHOW 30KTS 1-2KFT OFF THE SURFACE...BEGINNING TO MIX DOWN. RUC/ETA BOTH BRING A 35KT 850MB JET OVERHEAD...ALTHOUGH WEAKENING IT AS IT GOES. WINDS WILL INCREASE AGAIN TO 15 TO 25 MPH...BUT WILL HOLD OFF ON MENTIONING ANY ADDITIONAL HIGHER GUSTS. .DTX...GALE WARNING...THIS AFTERNOON AND THIS EVENING... LAKE HURON. BRAVENDER mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 530 AM EST SAT NOV 30 2002 MAIN FORECAST CONCERNS TODAY WILL BE WSW HEADLINES...LES AMOUNTS AND WIND. WV IMAGERY AND RUC ANALYSIS INDICATED SHRTWV/VORT JUST NE OF LK SUPERIOR. AT THE SFC...ASSOC 982 MB LO WAS LOCATED OVER WRN QUEBEC ONTARIO PULLING SLOWLY EWD WITH A COLD FRONT EXTENDING SE ACROSS CNTRL LWR MI AND SRN LAKE MI. 3 HR PRES RISES OF 3-4 MB WERE NOTED OVER WRN AND NRN LAKE SUPERIOR WHERE WINDS HAVE GUSTED TO OVER 40 MPH...SOME 40+ MPH WIND GUSTS ALSO REPORTED ERY THIS MORNING AT NWS MQT AND COPPER HARBOR ACRS CNTRL UPR MI. RADAR SHOWED BEST RETURNS FROM MQT TO KSAW WHERE DOMINANT LES BAND OF 30-40 DBZ SITUATED ATTM AND DROPPING SNOW AT 1-2"/HR. WITH H8 TEMPS TO AROUND -14C OVR ERN LAKE SUPERIOR AND -16C OVR THE WRN LAKE...LK-H8 DELTA/T APPROACHING 18-20C AND 850 MB TEMPS WILL CONTINUE TO FALL INTO THE UPPER TEENS BLO ZERO THIS AFT BRINGING LAKE DELTA-T'S ABOVE 20C. 00Z KINL/CWPL SNDGS INDICATED VERY DEEP MOIST PROFILE WITH INV HGTS WITH INVERSION HGTS NEAR 8K FT. COMBINATION OF ABUNDANT UPSTREAM MOISTURE AND INCREASING INSTABILITY OVER THE LAKE WILL CONTINUE TO INTENSIFY LES THRU MORNING HRS. STG CBL WINDS (30-40 KTS) AND 350 DIR FLOW WILL CONTINUE TO ALLOW HEAVY LES BANDS TO MOVE FAR INLAND...FAVORING HEAVIEST ACCUMS OVR ALL OF ERN MQT COUNTY AND WRN ALGER COUNTIES THRU MUCH OF DAY. SRN PORTIONS OF GOG-ONT-HOUGHTON AND BARAGA COUNTIES AND NRN PORTIONS OF IRON COUNTY WILL ALSO SEE HEAVIER SNOW THIS MORNING BUT THEN INCREASING DRIER AIR AND LWRG INV HGTS FM NW OF LAKE SUPERIOR WILL TEND TO PUT CRIMP ON SNOW AMTS BY LATE MORNING OVR WRN COUNTIES. STRONG WINDS WILL ALSO CARRY LES INTO NRN DELTA AND SCHOOLCRAFT COUNTIES. ETA DEPICTION OF STRONG 850-500 MB DRYING FROM 09Z-12Z SEEMS REASONABLE GIVEN WV/IR INDICATION OF DRYING OVER NW ONTARIO. SO...WL CONTINUE CURRENT WARNING AND ADVISORY HEADLINES TODAY WITH HEADLINES EFFECTIVE THRU MORNING FOR WRN COUNTIES AND THRU ALL OF TODAY FOR MQT-DELTA COUNTIES EWD. SNOWFALL AMOUNTS OF 1-4" WEST AND 3-7" EAST STILL LOOK ON TRACK BASED ON RADAR TRENDS AND MODEL FCST SNDG DATA. STG 20-35 MPH NLY WINDS WILL CONTINUE CONSIDERABLE BLOWING AND DRIFTING THRU MORNING AT LEAST THRU MORNING HRS. HIGH TEMPS WILL BE AT DAYBREAK AND THEN EXPECT STEADY OR SLOWLY FALLING READINGS THRU REST OF DAY UNDER FAIRLY STG CAA. VOSS A CLOSED LOW OVER WESTERN HUDSON BAY SATURDAY NIGHT IS EMBEDED IN A A LONGWAVE TROUGH WHICH BLANKETS MUCH OF EASTERN CANADA. THIS LOW WILL DIVE INTO NORTHERN ONTARIO BY SUNDAY MORNING. SHORTWAVE ENERGY ASSOCIATED WITH THIS LOW WILL REACH THE U.P. A SURFACE TROUGH WILL DEVELOP INTO A CLOSED LOW OVER EASTERN LAKE SUPERIOR OVERNIGHT. 850MB TEMPERATURE WILL DROP TO -20C OVER LAKE SUPERIOR WHICH WILL MAKE FOR A DELTA-T'S OF 24C. ETA IS LITTLE DRIER THAN GFS. THE VERY COLD AIR MASS GENERALLY PRODUCES DRIER CONDITIONS WHICH MAY LIMIT SIGNIFICANT LAKE EFFECT SNOW ACCUMULATION. GFS/ETA SHOWING MAINLY A NORTHWEST WIND. THIS WILL HAVE A TENDENCY TO PRODUCE THE HEAVIEST SNOW OVER THE KEWEENAW PENINSULA AND OVER ALGER AND LUCE COUNTIES...WHEREAS MARQUETTE AND BARAGA COUNTIES WOULD REMAIN IN THE SHADOW OF THE KEWEENAW PENINSULA. ETA IS DEPICTING STRONGEST LOW LEVEL CONVERGENCE ALONG THE SHORE BETWEEN ONTANAGON AND COPPER HARBOR AND BETWEEN MARQUETTE AND GRAND MARAIS. THE LONGER FETCHS SHOULD PRODUCE THE HEAVIEST ACCUMULATION OVER ALGER/LUCE/NORTHERN SCHOOLCRAFT COUNTIES SATURDAY NIGHT. MORE COLD AIR ADVECTION WILL INCREASE THE THE DELTA-T TO 26C BY SUNDAY EVENING. SURFACE-850MB LAPSE RATE AROUND 9.5C/KM. GFS/ETA WILL BE KEEPING THE WINDS OUT OF THE NORTHWEST OVER THE LAKE. A LITTLE HIGHER WINDS WILL ALSO BE MIXING TO SURFACE...SHORTENING UP THE FETCH. BOUNDARY LAYER WINDS WILL BE INCREASING TO 30 KTS OVER THE EASTERN PART OF THE LAKE ON SUNDAY. WINDS WILL REMAIN 20 TO 25 KTS OVER THE WEST. STRONGEST LOW LEVEL CONVERGENCE WILL CONTINUE ALONG THE LAKE SHORE BETWEEN IRONWOOD AND COPPER HARBOR AND BETWEEN MARQUETTE AND GRAND MARAIS. MARQUETTE AND BARAGA COUNTIES WILL CONTINUE TO BE SHADOWED BY THE KEWEENAW PENINSULA. WITH THE LONGER FETCH BEING OVER THE EASTERN U.P. LAKE EFFECT SNOW WILL HAVE THE GREATEST ACCUMULATION OVER THE EASTERN COUNTIES. THE UPPER LEVEL LOW WILL SWING THROUGH THE BASE OF THE LONGWAVE TROUGH AND INTO SOUTHERN QUEBEC BY MONDAY MORNING. SHORTWAVE ENERGY WITH THIS TROUGH WILL MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT. THE SURFACE LOW WILL MOVE INTO SOUTHEAST ONTARIO BY SUNDAY EVENING. STRONGEST LOW LEVEL CONVERGENCE WILL BE OVER CENTRAL LAKE SUPERIOR. DELTA-T'S WILL BE AROUND 26C SUNDAY EVENING. THIS WILL WARM TO 24C BY MONDAY MORNING. WINDS WILL VEER NORTH AND WEAKEN CONSIDERABLY OVERNIGHT. THUS LAKE EFFECT SNOW WILL BECOME LIGHT AND SCATTERED OVERNIGHT. SURFACE RIDGE WILL SLIDE INTO WESTERN ONTARIO ON MONDAY. THE SHORTWAVE WILL MOVE ACROSS THE AREA. THE AIR MASS WILL REMAIN COLD. THE WATER-850MB DELTA-T'S WILL BE 24C. BOUNDARY LAYER WINDS WILL BE FROM THE NORTH AHEAD OF THE RIDGE. THUS WILL KEEP A CHANCE OF LAKE EFFECT GOING FOR THE U.P. ADJACENT TO LAKE SUPERIOR. A LONGWAVE TROUGH WILL BLANKET THE EAST HALF OF CANADA ON TUESDAY. AN UPPER LEVEL TROUGH STRETCHES FROM A LOW OVER NORTHERN ONTARIO SOUTHWEST ACROSS THE NORTHERN PLAINS INTO SOUTHWEST CONTNENTAL U.S. (CONUS). A RIDGE RUNS UP THE WEST COAST SEPERATING THE CANADIAN LONGWAVE FROM ANOTHER LONGWAVE OVER NORTH CENTRAL PACIFIC. A WEAK SHORTWAVE MOVING THROUGH THE BASE OF THE LONGWAVE WILL MOVE ACROSS THE FORECAST AREA ON TUE. SURFACE RIDGE WILL MOVE OVER ONTARIO. FLOW AROUND THIS RIDGE WILL KEEP WINDS OUT OF THE NORTH. DELTA-T'S WILL BE AROUND 21C. SNOW SHOWERS WILL CONTINUE OVER THE NORTHERN U.P. ON WEDNESDAY. THESE SNOWS WILL BE ESPECIALLY HEAVY OVER THE NORTHERN U.P. .MQT...WINTER STORM WARNING THIS MORNING MIZ001>004-009-084. WINTER STORM WARNING TODAY MIZ005>007-085. LAKE EFFECT SNOW AND BLOWING THIS MORNING MIZ010. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY TODAY MIZ013-014. WINTER STORM WATCH TONIGHT AND SUN MIZ001>007-009-084-085. GALE WARNING LK SUPERIOR. DLG mi DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1000 AM CST SAT NOV 30 2002 SHORT TERM...RUC GUIDANCES SHOWS AN ELONGATED POCKET OF VORTICITY LYING ROUGHLY ALONG THE TX COASTLINE GENERATING A BROAD SURFACE LOW OVER THE NW GULF OF MEX. THIS IS PROVIDING ENOUGH LIFT TO SPARK OFF A FEW SPRINKLES IN THE FIRST PERIOD. WILL LEAVE THE FIRST PERIOD WORDING AS IS. MORNING TEMPS AROUND THE CWA HAVE RISEN INTO THE LOWER TO MID 60S. MAV AND MET HIGH TEMPS ARE IN PRETTY GOOD AGREEMENT FOR HIGHS THIS AFTERNOON AND WILL LEAVE THIS WARMING TREND IN PLACE FOR THIS AFTERNOON. MARINE...BUOY020 CHECKS IN THIS MORNING WITH A NORTH WIND NEAR 15 KTS WITH SWELLS NEAR 3 FT. THE BROAD SURFACE LOW OVER THE NW GULF WILL KEEP THE NORTHERLY WINDS IN PLACE OVER THE BRO MARINE AREAS. CURRENT CWF LOOKS OK. SYNOPTIC-AVIATION-MARINE...60/MESO...WATKINS INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 245 PM MST SAT NOV 30 2002 SPINNING CLOSED LOW CENTERED OVER SOUTHERN CALIFORNIA IN THE PROCESS OF SHEARING EASTWARD DURING THE NEXT 24 HOURS. DEFORMATION AXIS THIS AFTERNOON WAS SITUATED WEST TO EAST ACROSS CENTRAL UTAH AND SOUTHWEST COLORADO. THIS AXIS WILL SLOWLY SHIFT NORTHWARD AND BE LOCATED FROM NORTHEAST UTAH INTO WEST CENTRAL COLORADO. LATEST SATELLITE IMAGERY SHOWS DEFORMATION ZONE STRENGTHENING WITH A CLOUD SHIELD EXPANDING. THE RUC MODEL AND MESOETA SHOWS PRECIPITATION INCREASING OVERNIGHT. GIVEN CURRENT TRENDS OFFERED ON SATELLITE IMAGES.. WILL BOOST POPS ENTIRE FORECAST AREA OVERNIGHT. WESTERLY JET WILL BE POSITIONED OVER ARIZONA AND NEW MEXICO.. LEAVING OUR FORECAST AREA WITH RELATIVELY LIGHT WINDS ALOFT (LESS THAN 20 KNOTS AT H7 LEVEL.) WITH THE LACK OF WINDS ALOFT.. LOOKING FOR SNOW AMOUNTS TO STAY BELOW ADVISORY CRITERIA. THE SOUTHWESTERN SAN JUANS WILL HAVE A PERIOD OF DECENT SNOW ACCUMULATION FROM MIDNIGHT TO 6 AM OVERNIGHT.. THEN THE WINDS SHIFT TO A WESTERLY COMPONENT FOR DECREASING SNOW SHOWERS. APPEARS SNOW ACCUMULATIONS FOR THE SAN JUANS WILL RANGE FROM 3 TO 5 INCHES. BEHIND THE DEFORMATION AXIS.. STATIC STABILITY DECREASES FOR THE SOUTHERN HALF OF FORECAST AREA.. MAKING PRECIPITATION MORE SHOWERY. ONCE AGAIN.. DUE TO THE LACK OF JET SUPPORT.. SHOWERS WILL BE DISORGANIZED AND MORE HIT AND MISS. FOR SUNDAY NIGHT AND MONDAY.. LOW LYING MOISTURE WILL LINGER ACROSS NORTHWESTERN COLORADO. THE AIR MASS WILL BE STABLE THROUGH THIS PERIOD.. SO CLOUD COVER WILL BE WIDESPREAD BUT SNOW CHANCES WILL NOT BE VERY HIGH. ON TUESDAY.. A THERMAL GRADIENT DEVELOPS DUE TO AN APPROACHING COLD FRONT AND SHORT WAVE ALOFT FROM THE NORTH. AGEOSTROPHIC FLOW ALOFT ALLOWS SURFACE TROUGH TO FORM.. INCREASING LOW LEVEL CONVERGENCE. SNOW CHANCES FOR NORTHWEST COLORADO WILL INCREASE (FROM SLIGHT CHANCE TO CHANCE.) FOR THE SOUTHERN HALF.. DRY WEATHER EXPECTED AS REMNANTS OF DEFORMATION ZONE BREAKS APART. AND WHAT/S LEFT OF THE CLOSED LOW CIRCULATION EJECTS EASTWARD SOUTH OF COLORADO. FRISBIE EXTENDED...(WED-SAT) TDYS MRF SOLUTION MORE IN LINE WITH YDAS EC... WITH SLOWER MOVEMENT OF SHORTWAVE INTO OUR CWA. EVEN THIS LATEST MRF RUN FASTER AND STRONGER THAN CURRENT EC PROGS. FEEL THAT WITH OMEGA BLOCK LIKE PATTERN THE EC SOLUTION IS PROBABLY THE BEST CHOICE. WITH THAT SAID THE EC DOES BRING A SFC FRONT/BAROCLINIC BOUNDARY TO OUR NRN BORDER WED...THEN IT APPEARS TO SLIDE DOWN THE EAST SLOPES. AT THIS TIME BELIEVE SFC FRONT WILL ONLY AFFECT NRN ZONES WITH COOLER AIR FILTERING OVER THE REMAINDER OF THE CWA LATE WEDNESDAY AND EARLY THURSDAY. DYNAMIC AND OROGRAPHIC LIFT SHOULD BE ENUF TO GENERATE SNOW OVER THE NORTH...SO WILL INTRODUCE SLIGHT CHANCE AT THIS TIME. THURSDAY AND FRIDAY APPEAR DRY WITH A NORTHWEST FLOW...THEN THE MRF INDICATES ANOTHER CLOSED LOW TRIES TO MOVE INLAND FROM OFF THE CA COAST SATURDAY. USUALLY TIMING OF EJECTING CUTOFF LOWS IS TO FAST...BUT ADVERTIZED CHANGES IN HEMISPHERIC FLOW PATTERN WOULD INDICATE THE DEVELOPMENT OF A MORE PROGRESSIVE PATTERN BY LATE NEXT WEEK. SO DUE TO SOME UNCERTAINTY WILL LEAVE SATURDAY DRY FOR NOW. .GJT...NONE. co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1201 PM EST SAT NOV 30 2002 FATE OF ONGOING WRNGS/ADVYS IS THE MAIN CONCERN TODAY. SFC DATA SHOW INCREASINGLY DRIER AIR HEADING ACROSS LK SUPERIOR AS DWPTS NOW RANGE FROM 0 TO -10F ON UPWIND SIDE OF LK. UPSTREAM 12Z CWPL SOUNDING SHOWS INVERSION BASED AT ABOUT 1KFT AGL WITH NOTABLE DRYING FROM 2KFT AGL UPWARDS. IMPACT OF THIS DRIER AIR AND FALLING INVERSION IS VERY EVIDENT AS SATELLITE IMAGERY SHOWS CLOUD DEVELOPMENT OCCURRING INCREASINGLY FARTHER OFFSHORE ON NW SIDE OF LK SUPERIOR. ECHOES WHICH KDLH RADAR HAD BEEN SHOWING NEAR KIWD HAVE DISAPPEARED AND KMQT RADAR SHOWS LES BANDS W OF KMQT BEGINNING TO DIMINISH. LONG FETCH IS STILL PRODUCING SOME HEAVY LES FROM ERN MARQUETTE COUNTY EWD...AND STRONG WINDS ARE PUSHING THESE BANDS WELL INLAND INTO DELTA AND SCHOOLCRAFT COUNTIES. PURE LES CONDITIONS WILL BE THE RULE THIS AFTN. WITH DRIER AIR AND LOWERING INVERSION...EXPECT INCREASING SEPARATION BTWN WIND PARALLEL BANDS WITH STEADILY DIMINISHING INTENSITY. GIVEN THAT THIS TREND IS WELL UNDERWAY OVER WRN LAKE PER SATELLITE IMAGERY AND WIND IS CONTINUING TO DIMINISH...EXPECT A RAPID IMPROVEMENT IN CONDITIONS SHORTLY. WILL ALLOW ADVYS/WRNGS FOR BARAGA/IRON WWD TO EXPIRE WITH UPDATE. WILL LEAVE ALGER/LUCE/NRN SCHOOLCRAFT IN WRNG THIS AFTN ALTHOUGH BLSN WILL BE DIMINISHING. SNOW INTENSITY WILL ALSO DIMINISH...BUT STILL EXPECT 2 TO 5 INCHES THERE. WILL ALSO HOLD ON TO ADVY IN SRN SCHOOLCRAFT FOR THE AFTN...THOUGH ADDITIONAL ACCUMULATIONS WILL BE 1 TO LOCALLY 3 INCHES. WILL ALSO KEEP WRNGS FOR MARQUETTE/DELTA AS THE TYPICAL DOMINANT BAND FROM OFF TIP OF THE KEWEENAW INTO FAR ERN MARQUETTE COUNTY WILL PERSIST UNTIL LATE AFTN WHEN WIND BEGINS TO BACK PER 12Z RUC. WIND SHOULD REMAIN STRONG ENOUGH TO BRING THIS HVY BAND INTO DELTA COUNTY...MAINLY E OF M-35. EXPECT GENERALLY STEADY TEMPS THRU THE AFTN. AFTER A QUICK LOOK AT INCOMING 12Z ETA/NGM...HAVE OPTED TO PULL WATCH FROM GOGEBIC/MARQUETTE/BARAGA/SRN HOUGHTON FOR TONIGHT. AS THOUGHT YESTERDAY...MODELS ARE SHOWING LOW-LEVEL WINDS BACKING W OR EVEN WSW TONIGHT AS LK INDUCED SFC TROFFING STRENGTHENS OVER LAKE IN ADVANCE OF 5H LOW APPROACHING FROM THE N. BACKING OF WINDS WILL ALSO BE AIDED BY LAND BREEZE COMPONENT TO THE WIND. WILL LEAVE WATCH UP FOR THESE 3 COUNTIES ON SUN WITH TIMING OF WIND SHIFT TO NW/N STILL IN QUESTION. REMAINING WATCHES WILL REMAIN AS IS FOR THE MOMENT. ONLY OTHER CHANGE IS TO EXTEND WATCHES INTO SUN NIGHT AS CONDITIONS WILL STILL BE FAVORABLE SUN EVENING. .MQT...WINTER STORM WARNING THIS AFTN MIZ005>007-013-085. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY THIS AFTN MIZ014. WINTER STORM WATCH TONIGHT THRU SUN NIGHT MIZ001>003-006-007-085. WINTER STORM WATCH SUN-SUN NIGHT MIZ004-005-009-084. GALE WARNING LK SUPERIOR. ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1154 AM EST SAT NOV 30 2002 LAKE EFFECT SNOW EVENT WELL UNDERWAY ACROSS THE STATE WITH COLD AIR POURING IN OVER THE LAKES. ONE ENHANCED BAND SET UP THIS MORNING ACROSS WESTERN ALLEGAN COUNTY...EXTREME EASTERN VAN BUREN COUNTY AND EXTREME WESTERN KALAMAZOO COUNTY. RECEIVED REPORTS OUT OF ALLEGAN COUNTY OF 3 TO 5 INCHES THROUGH 10 AM WITH SNOW STILL FALLING. HAVE NOT BEEN ABLE TO GET RECENT REPORTS UNDER THE BAND IN W KALAMAZOO COUNTY OR E VAN BUREN COUNTY. UP NORTH...REPORTS OF 2-3 INCHES ARE POPULAR ALONG THE LAKESHORE WITH LOTS OF BLOWING SNOW...WITH LESSER AMOUNTS FARTHER INLAND. SEE ARBPNSGRR FOR THE LATEST SNOWFALL REPORTS. HAVE DECIDED TO DOWNGRADE THE WARNING TO AN ADVISORY FOR ALL WARNED COUNTIES EXCEPT ALLEGAN...VAN BUREN...AND KALAMAZOO. ALSO HAVE DECIDED TO CANCEL THE ADVISORY FOR THE COUNTIES THAT WERE UNDER AN ADVISORY. IR SATELLITE SHOWS MID AND HIGH CLOUDS ARE MOVING EAST OUT OF THE AREA. THE LATEST RUC SHOWS LOW LEVEL MOISTURE DECREASING AS THE AFTERNOON PROGRESSES. THIS WILL HELP LIGHTEN UP SNOWFALL ACCUMS ACROSS THE AREA A BIT THIS AFTERNOON. RADAR IMAGERY VERIFIES THIS AS IT SHOWS THE SHSN COVERAGE DECREASING SOME OVER THE LAST HOUR OR SO. HOWEVER...WITH LAKE TO 850 MB DELTA T/S IN THE UPPER TEENS TO LOWER 20S...SNOW SHOWERS WILL STICK AROUND...ESPECIALLY CLOSER TO THE LAKESHORE. UPDATED ZONES OUT. NJJ .GRR...LAKE EFFECT SNOW WARNING TODAY...064-071-072... LAKE EFFECT SNOW ADVISORY TODAY...037-038-043-050-056... LAKE EFFECT SNOW WATCH SUNDAY...056-057-064-065. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 324 PM EST SAT NOV 30 2002 COLD AIR DEEPENING IN WELL ALIGNED NORTHWEST FLOW WILL PRODUCE SIGNIFICANT LAKE SNOWS ACROSS CHAUTAUQUA AND CATTARAUGUS COUNTIES TONIGHT...AS WELL AS OSWEGO AND NORTHERN CAYUGA. MODERATE TO EXTREME INSTABILITY DEVELOPING OVER THE LAKES WITH NO CAP AND 850 MB TEMPERATURES DROPPING TO AROUND -16C GIVING DELTA T'S OF ABOUT 22C. 12Z MM5 SUGGESTING CONNECTION WITH LAKE HURON AND GEORGIAN BAY SETTING UP. COULD EASILY AMOUNTS OF 12 TO 18 INCHES ACROSS THE AREAS. WEAK SURFACE LOW DEPICTED BY MODELS TRACKING JUST NORTH OF THE AREA WILL BACK WINDS TO WEST SOUTHWEST BY SUNDAY AFTERNOON. STILL A QUESTION REMAINS WHETHER SIGNIFICANT LAKE BANDS CAN HOLD TOGETHER AS THEY SHIFT NORTH TOWARD THE BUFFALO AND WATERTOWN AREAS. FEELING IS THAT THE COLD AIR WILL BE DEEP ENOUGH AND THERE WILL BE ENOUGH INSTABILITY FOR THIS TO HAPPEN...BUT ETA12 AND RUC10 SUGGESTING THAT THIS WILL NOT BE THE CASE. BOTH THESE MODELS GREATLY WEAKEN THE LAKE ACTIVITY. THIS HAS CAUSE A LITTLE UNCERTAINTY TO WHAT IS GOING TO HAPPEN...THEREFORE WILL CONTINUE WITH A WATCH OVER ERIE AND WYOMING COUNTIES AND ADD JEFFERSON AND LEWIS COUNTIES TO THE WATCH SUNDAY AFTERNOON AND SUNDAY NIGHT. .BUF...LAKE EFFECT SNOW WARNING TONIGHT THROUGH NOON SUNDAY NYZ019-020. LAKE EFFECT SNOW WARNING TONIGHT AND SUNDAY NYZ005. LAKE EFFECT SNOW WARNING TONIGHT THROUGH SUNDAY EVENING NYZ006. LAKE EFFECT SNOW ADVISORY TONIGHT AND SUNDAY MORNING NYZ004. LAKE EFFECT SNOW WATCH SUNDAY AFTERNOON AND SUNDAY NIGHT NYZ007-008-010-012. TMA ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 1050 AM CST SAT NOV 30 2002 MID CLOUD ASSOCIATED WITH 130 KNOT UPPER JET BEGINNING TO DECREASE IN COVERAGE ACROSS FAR EASTERN SOUTH DAKOTA. FURTHER TO THE WEST ACROSS WEST CENTRAL NORTH DAKOTA WEAK SURFACE WARM FRONT ANALYZED WITH SURFACE WINDS BECOMING MORE SOUTHERLY BEHIND THIS TROUGH. ALTHOUGH MIXING LIMITED TO SHALLOW NEAR SURFACE LAYER THIS AFTERNOON...RUC DATA SUGGESTING LOW CLOUD BREAKUP THIS AFTERNOON ACROSS NORTHWEST AND WILL BUY INTO THIS AND NOT TWEAK DOWN TEMPERATURES TOO MUCH. TEMPERATURES ACROSS REMAINDER OF CWA LOOK TO BE IN GOOD SHAPE FOR NOW. THING TO MONITOR FOR THIS AFTERNOON IS TEMPERATURE INFLUENCE OF LOW CLOUDS IF THEY ARE SUSTAINED FURTHER TO THE EAST BUT TEMPERATURE GRIDS FOR THIS AFTERNOON WILL BE UNDER THE ASSUMPTION OF LOW CLOUDS DIMINISHING FAIRLY QUICKLY THIS AFTERNOON. OTHERWISE...ONLY MINOR TWEAKS TO WINDS. UPDATED ZONES HAVE BEEN SENT. .ABR...NONE MARSILI sd