AREA FORECAST DISCUSSION...UPDATED FOR AVIATION DISCUSSION NATIONAL WEATHER SERVICE LITTLE ROCK AR 1137 AM CST WED MAR 15 2006 .AVIATION... FOR AVIATION CONCERNS...VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 09Z. RUC AND NAM ARE INDICATING THE POTENTIAL FOR CIGS OF 1500-2000 FT TO DEVELOP ACROSS MUCH OF CENTRAL AND SOUTHERN ARKANSAS...INCLUDING ...LIT...HOT...AND PBF...FROM 11-16Z. WINDS WILL BE SOUTHERLY FROM 8-11 KTS AT ALL SITES...THEN WILL SLOWLY VEER AFTER 06Z. PRECIPITATION CHANCES ARE TOO SMALL TO WARRENT MENTION IN FORECASTS. 55 && .PREV DISCUSSION.../ISSUED 1034 AM CST WED MAR 15 2006/ UPDATE... UPDATE WILL BE OUT SHORTLY. MAINLY HAD TO REMOVE THE MORNING WORDING. ALSO...TEMPS ARE WARMING FASTER THAN INCLUDED IN THE GRIDS. BELIEVE THAT MAXES WERE A COUPLE OF DEGREES TOO LOW FOR TODAY. CLOUDS HAVE NOT INCREASED AS MUCH EITHER...SO BACKED OFF ON CLOUD COVER AS WELL. DEW POINTS HAVE REMAINDED FAIRLY LOW IN LIGHT OF CLOSED GULF AND THE DRY AIR WILL WARM JUST A TAD MORE THAN EXPECTED IN EARLIER ISSUANCE. PREV DISCUSSION.../ISSUED 320 AM CST WED MAR 15 2006/ SHORT TERM...TODAY THROUGH SATURDAY MOSTLY CLEAR SKIES PREVAILED OVERNIGHT...WITH HIGH CLOUDS JUST NOW ENCROACHING. HIGH PRESSURE SLOWLY MOVED IN THE EASTERN ARKANSAS DELTA...WITH TEMPS THIS MORNING IN THE MID 30S TO THE UPPER 40S. HIGH PRESSURE WILL CONTINUE TO MOVE EAST TODAY...WITH SOUTHERLY WINDS RETURNING. CLOUDS WILL BEGIN TO INCREASE THIS AFTERNOON IN THE WEST...AS A COLD FRONT APPROACHES THE STATE. TEMPS WILL REMAIN MILD WITH AFTERNOON READINGS IN THE MID 60S TO LOWER 70S. MOISTURE RETURN AHEAD OF THIS COLD FRONT STILL LOOKS WEAK...WITH HIGHEST MOISTURE IN THE SOUTH. HELD OFF ON ANY POPS UNTIL AFTER MIDNIGHT TONIGHT...WITH HIGHEST POPS AFTER SUNRISE ON THURSDAY. EVEN SO...QPF AMOUNTS WILL REMAIN UNDER A QUARTER OF AN INCH. FRONT MOVES OUT OF THE STATE THURSDAY AFTERNOON...WITH HIGH PRESSURE MOVING IN FROM THE NORTH. READINGS FRIDAY MORNING WILL BE AROUND 10 DEGREES COOLER THAN THURSDAY MORNING. DRY AND COOL CONDITIONS WILL CONTINUE FRIDAY...BEFORE MOISTURE MOVES NORTH IN RETURN FLOW AROUND HIGH PRESSURE. AS THIS AIR MOVES OVER THE COOLER AIR AT THE SURFACE...STEADY RAIN WILL DEVELOP FRIDAY NIGHT INTO SATURDAY. THIS SYSTEM WILL CONTINUE THROUGH THE WEEKEND...AND COULD BRING THE REGION SUBSTANTIAL RAINFALL AMOUNTS. LONG TERM...SATURDAY NIGHT THROUGH TUESDAY UPPER TROF IN THE SOUTHWEST WITH SEVERAL SHORT WAVES LIKELY TO BE EMANATING OUT OF IT DURING MOST OF THE PERIOD. COLD SURFACE HIGH WILL BE IN PLACE AT THE START OF THE EXTENDED PERIOD WHICH RELAXES SOME WITH TIME. WARM FRONT STAYS WELL TO THE SOUTH OF THE AREA SO A PROLONGED OVERRUNNING PERIOD IS SET UP FOR THE AREA. CONTINUED LIKELY POPS SATURDAY NIGHT THEN HIGH CHANCE POPS FOR MOST OF THE REST OF THE PERIOD. PRECIPITATION SHOULD GENERALLY BE LIGHT RAIN. ELEVATED INSTABILITY MAY INCREASE WITH TIME AS THE UPPER LOW GETS A LITTLE CLOSER AND THE AIR MASS MODIFIES SO MENTION OF ISOLATED THUNDER KEPT IN FROM MIDDAY SUNDAY ON. UPPER TROF COMES OUT ON MONDAY AND TAKES ON A NEGATIVE TILT. THIS COULD BRING THE WARM FRONT NORTH ACROSS PARTS OF THE AREA...WITH THE EAST MORE FAVORED...AND POSE A CHANCE FOR SEVERE WEATHER. GFS IS HINTING AT A LINE OF ACTIVITY MOVING ACROSS THE AREA ON MONDAY WHICH COULD BE A SQUALL LINE. HOWEVER THIS FAR OUT TIMING AND DETAILS ARE STILL VAGUE SO WILL CONTINUE TO BROAD BRUSH CHANCES OF RAIN AND ISOLATED THUNDER FOR NOW. ALSO NOT OVERLY CONFIDENT SYSTEM WILL MOVE OUT AS PROGGED SO CONTINUED SMALL POPS THROUGH TUESDAY. TEMPS PROBABLY WILL SHOW A SLOW WARMING TREND BUT WILL GENERALLY BE BELOW NORMAL...ESPECIALLY THE MAXES. LZK WATCHES/WARNINGS/ADVISORIES... NONE. $$ && .LZK WATCHES/WARNINGS/ADVISORIES... NONE. && $$ AVIATION... ar AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 238 PM MST WED MAR 15 2006 .SHORT TERM DISCUSSION...RUC QG ANALYSES SHOWING PRETTY DECENT AND DEEP ASCENT OVER THE PLAINS AT THIS TIME BUT IT IS LIFTING FAIRLY DRY AIR SO ONLY A FEW SHOWERS ARE DEVELOPING IN THIS AREA. WILL HOLD ONTO VERY SLIGHT POPS OVER THE NORTHEAST CORNER THIS EVENING. PERHAPS MORE IMPORTANTLY IS THE INCREASINGLY SUBSIDENT AIR HEADING OUR WAY FROM THE WEST WHICH IS STARTING TO SHUT PRECIPITATION DOWN IN THE MOUNTAINS. OROGRAPHIC FLOW WILL KEEP A FEW SNOW SHOWERS GOING UNTIL LATER TONIGHT BUT BRUNT OF SNOWFALL APPEARS TO BE COMING TO AN END. PLENTY OF WIND AROUND IN ALL AREAS AT THIS TIME WITH A MODERATE BORA EVENT UNDERWAY EAST OF THE MOUNTAINS. LOW STATIC STABILITY SHOULD PRECLUDE ANY STRONG MOUNTAIN WAVE ACTIVITY AS FORECAST ON THE MM5 SO WINDS SHOULD BE RELATIVELY UNIFORM ACROSS THE DISTRICT. THEY MAY PICKING UP SOME IN THE HIGHEST AREAS ALONG THE DIVIDE LATER TONIGHT AS STABILITY INCREASES SOME BUT AM EXPECTING THEM TO SETTLE DOWN AFTER SUNDOWN ELSEWHERE AND WILL KEEP RED FLAG WARNING GOING UNTIL 02Z. THURSDAY SHOULD BE A QUIET DAY WITH WEAK RIDGING COMING IN. .LONG TERM DISCUSSION...THURSDAY NIGHT THROUGH SATURDAY NIGHT: RIDGE STILL EXPECTED TO HANG ON THROUGH FRIDAY...THEN SHIFT EAST SATURDAY WITH THE FLOW ALOFT BECOMING SOUTHWEST IN RESPONSE UPPER TROUGH DIGGING INTO THE GREAT BASIN. CROSS SECTIONS INDICATE MOISTURE TO INCREASE ACROSS THE MOUNTAINS BY FRIDAY AFTERNOON...BUT SOUTHWEST FLOW WILL LIMIT PRECIPITATION CHANCES. ACROSS PLAINS... LOW LEVEL FLOW BECOMES SOUTHEASTERLY FRIDAY IN RESPONSE TO SURFACE HIGH SLIDING SOUTH ACROSS THE GREAT PLAINS. HOWEVER...LOW LEVEL MOISTURE DOESN'T INCREASE UNTIL SATURDAY...SO WILL HOLD OFF ON ANY POPS UNTIL THE AFTERNOON. THUNDERSTORM CHANCES LOOK LOW GIVEN LACK OF ANY CAPE FROM FORECAST SOUNDINGS. WILL LOWER MAX TEMPERATURES ACROSS PLAINS A FEW DEGREES EACH DAY DUE TO POTENTIAL FOR MORE CLOUD COVER. MAIN FOCUS CONTINUES TO BE THE STORM SYSTEM FOR THE SUNDAY-MONDAY TIME FRAME. MID RANGE MODELS STILL SHOWING POTENTIAL FOR A HEAVY SNOW EVENT FOR NORTHEAST AND NORTHCENTRAL COLORADO. LATEST GFS BEGINNING TO COME AROUND TO THE OTHER MODEL SOLUTIONS...INDICATING BEST TIMEFRAME FOR SNOW ACCUMULATIONS SUNDAY EVENING THROUGH MONDAY MORNING WHEN UPPER LOW EXPECTED TO SHIFT INTO SOUTHEAST COLORADO. SHOULD SEE SURFACE CYCLOGENESIS OVER SOUTHEASTERN PLAINS SOMETIME SUNDAY AFTERNOON/EVENING...WITH BEST UPSLOPE OVERNIGHT SUNDAY. SOME MODEL UNCERTAINTIES AS TO POSITION OF SURFACE LOW AND RESULTANT STRENTH OF UPSLOPE...THOUGH THE WINDOW OF OPORTUNITY BECOMING A BIT MORE APPARENT. STILL A BIT TOO FAR OUT TO MAKE SIGNIFICANT CHANGES TO ONGOING FORECASTS AT THIS TIME. WILL LOWER TEMPERATURES A FEW DEGREES MONDAY. LOOKING AT TUESDAY AND WEDNESDAY...STILL A BROAD TROUGH EXPECTED OVER AREA...WITH GFS KEEPING SOME QPF THROUGH WEDNESDAY. HOWEVER...WITH LACK OF ANY UPSLOPE...WILL KEEP THINGS DRY ACROSS PLAINS. && .BOU WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING UNTIL 16/02Z FOR FIREWEATHER ZONES 241..244>247 AND 249. && $$ D-L/ET co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 352 AM MST WED MAR 15 2006 .SHORT TERM... (TODAY AND TONIGHT) SHORT TERM CONCERNS REMAIN CRITICAL FIRE POTENTIAL ACROSS EASTERN COLORADO ALONG WITH SNOW POTENTIAL ACROSS THE CENTRAL AND SW MTS. CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING MODERATE TO STRONG SOUTHWEST FLOW ALOFT ACROSS THE STATE IN ADVANCE OF SHORT WAVE TROUGH MOVING ACROSS WESTERN UTAH ATTM. WATER VAPOR IMAGERY ALSO INDICATING AMPLE HIGH LEVEL MOISTURE EMBEDDED IN THE FLOW STREAMING ACROSS THE DESERT SW THROUGH THE ROCKIES ATTM. AT THE SFC...LOWERING PRESSURE ACROSS THE EASTERN PLAINS IN ADVANCE OF THE UPPER SYSTEM WITH MSAS DATA INDICATING 3MB PRESSURE FALLS VCNTY BURLINGTON IN THE PAST 3HRS. WINDS HAVE ALREADY PICKED UP ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS...WITH GUSTS UP TO 50 MPH BEING RECORDED ACROSS PORTIONS OF TELLER COUNTY AND ACROSS THE WESTERN FOOTHILLS OF EL PASO COUNTY WITH GUSTY SW WINDS ALSO BEING REPORTED ACROSS THE LOWER EASTERN SLOPES OF THE SANGRE DE CRISTO AND WET MTS. WINDS HAVE ALSO KEPT TEMPS UP THIS MORNING AND RHS DOWN WITH DEW PTS IN THE SINGLE DIGITS AND TEEN ACROSS THE REGION ATTM. TODAY...WESTERN UTAH SHORT WAVE CONTINUES TO MOVE ACROSS NORTHWEST COLORADO...WITH ASSOCIATED 100KT JET CORE MOVING ACROSS SOUTH CENTRAL COLORADO. SFC LOW CONTINUES TO DEEPEN ACROSS THE FAR EASTERN PLAINS IN RESPONSE TO STRONG DOWNSLOPE FLOW. TIGHTENING H7 GRADIENT ACROSS THE EASTERN MTS WITH H7 WINDS INCREASING TO BETWEEN 30-40KTS...ALONG WITH LAPSE RATES AROUND 8C/KM...WILL ALLOW THE STRONGER WINDS TO MIX DOWN ACROSS SOUTHEAST COLORADO THROUGH THE LATE MORNING AND AFTERNOON AND SHOULD SEE SUSTAINED WINDS AROUND 20-30 MPH WITH GUSTS BETWEEN 40-50 MPH ACROSS THE AREA TODAY. STRONG DOWNSLOPE AND H7 TEMPS BETWEEN -2C AND +2C WOULD SUPPORT TEMPERATURES IN THE 60S TO MID 70S ACROSS THE EASTERN PLAINS...THOUGH HAVE TEMPERED HIGHS A TAD WITH BOUTS OF HIGH LEVEL CLOUDS. WITH THIS SAID...WILL LIKELY SEE CRITICAL FIRE WX POTENTIAL AND HAVE UPGRADED THE CURRENT FIRE WX WATCH TO A RED FLAG WARNING FOR ZONES 221...222 AND 225 BELOW 9K FT AND ZONES 226-237 FROM 10AM TO 8PM MST. AS FOR SNOW POTENTIAL...REGION RADARS INDICATING SCATTERED SHOWERS ACROSS CENTRAL UTAH ATTM ASSOCIATED WITH SHORT WAVE TROUGH. SHOULD SEE ISOLATED TO SCATTERED SHOWERS DEVELOPING ACROSS WESTERN COLORADO THIS MORNING AND ACROSS THE NORTHERN AND CENTRAL MTS THROUGH THE AFTERNOON. MODELS CONTINUE TO KEEP BEST MOISTURE AND LIFT NORTH OF THE AREA...HOWEVER...WITH CAA AND WESTERLY FLOW DEVELOPING BEHIND WAVE THIS AFTERNOON...HAVE KEPT SCATTERED TO NUMEROUS POPS WITH 1 TO 4 INCHES OF SNOW ACROSS THE HIGHER ELEVATIONS OF LAKE AND WESTERN CHAFFEE COUNTY. COULD SEE SOME ISOLATED SHOWERS ACROSS THE SW MTS AND REST OF THE HIGHER TERRAIN WITH SOME WEAK QG IMPLIED ASCENT MOVING ACROSS THE REGION...HOWEVER WITH DRY LOWER ATMOSPHERE...WOULD ONLY SEE SOME VIRGA AND GUSTY WINDS. TONIGHT...MODERATING WEST TO NORTHWEST FLOW CONTINUES ALOFT AS SHORT WAVE AND SFC LOW QUICKLY LIFTS OUT ACROSS THE CENTRAL HIGH PLAINS...ALLOWING FOR WEAK BORA ACROSS THE AREA WITH BREEZY WEST TO NORTHWEST WINDS SLOWLY DIMINISHING ACROSS THE REGION OVERNIGHT. MOISTURE QUICKLY SHALLOWS OUT ACROSS THE CENTRAL MTS...WITH SCATTERED POPS THROUGH THE EVENING DIMINISHING TO FLURRIES OVERNIGHT. -MW .LONG TERM... (THU THROUGH TUE) ...COMPLEX AND ACTIVE WEATHER PATTERN IN THE OFFING FOR THIS WEEKEND... THU...MIDDLE AND UPPER LEVEL WLY FLOW CONTINUES ACROSS THE CNTRL ROCKIES. LOW AND MIDLEVEL S-SLY WINDS BEGIN TO ADVECT WARMER AND HIGHER MOISTURE THROUGH NM AND THE SRN PLAINS. MAY ACTUALLY START TO SEE NOCTURNAL MCS ACTIVITY WELL TO THE S AND E OF CO...MUST BE GETTING CLOSE TO SPRING. TEMPERATURES SHOULD BE NEAR AVERAGE READINGS FOR MID-MARCH. FRI THROUGH MON...THE FORECAST BECOMES MORE UNSETTLED AND COMPLEX GETTING INTO THE WEEKEND AND EARLY NEXT WEEK. AN APPROACHING (OLD) CLOSED LOW MOVES INTO THE FOUR CORNERS REGION BY SAT NGT AND IS PROJECTED TO MOVE EWD ALONG CO/NM BORDER SUN AND MON. THE SYSTEM EVOLUTION WILL BE THE KEY TO WHAT KIND OF WEATHER AND HOW SIGNIFICANT IT WILL BE. MIDDLE AND UPPER LEVEL S-SW FLOW SHOULD FOCUS THE HIGHEST QPF IN THE SAN JUAN MOUNTAINS WITH LESSER AMOUNTS JUST TO THE N. THE CNTRL MOUNTAINS DO NOT DO WELL WITH S-SWLY FLOW...HOWEVER... MIDLEVEL LAPSE RATES WILL BE MODERATELY UNSTABLE (E.G. H7-H5 7-8 C/KM) AND COULD PROMOTE MODERATE TO HEAVY SNOW SHOWERS. THERE COULD BE SEVERAL MORE FEET OF SNOW IN THE OFFING FOR THE SAN JUAN MOUNTAINS OVER THE WEEKEND. E OF THE CONTDVD... AGAIN IT DEPENDS ON THE EVOLUTION OF THE LOW. IF THE GFS SOLUTION OF AN OLD CLOSED LOW IS CORRECT...THEN PRECIPITATION WILL LIKELY BE MORE SHOWERY WITH VARYING ELEVATIONS OF SNOW LEVEL DEPENDING ON THE STRENGTH OF THE DIABATIC AND EVAPORATIVE COOLING. THE ECMWF IS A LITTLE MORE INTENSE AND COMPACT WITH THE LOW SUN AND MON AS THE H5 LOW TRACKS ALONG THE CO/NM BORDER. THIS COULD BE AN INTERESTING SCENARIO...ESPECIALLY IF THE LOW IS A LITTLE FURTHER S AND SLOWER. CONVECTIVE PRECIPITATION "BLOBS" COULD FORM ACROSS THE CNTRL PLAINS FROM THE POTENTIAL MCS ACTIVITY. THE MOISTURE RICH "BLOBS" COULD WRAP AROUND THE LOW TOWARDS ERN CO...BUT THERE IS MUCH UNCERTAINTY WITH THIS SCENARIO. LAPSE RATES WITHIN THE CLOSED LOW/UPPER TROUGH ARE PROGGED TO BE MODERATELY-EXTREMELY UNSTABLE...7.0-9.0 C/KM...SO THERE COULD BE A COUPLE OF LIGHTNING STRIKES. ON SUN AFTN/EVE...A POTENTIAL SQUALL LINE MAY DEVELOP JUST S OF CO IN WRN TX/WRN OK ALONG THE DRYLINE. SFC DEW POINTS MAY APPROACH 40F IN BACA CO...SO SOME OF THIS ACTIVITY COULD FORM IN EXTREME SERN CO. WILL HOLD OFF "LOADING UP" THE FORECAST WITH THUNDERSTORMS RIGHT NOW. ONLY MADE A FEW TWEAKS TO THE FORECAST FOR SPATIAL CONSISTENCY. TUE...LOTS OF UNCERTAINTY HERE. THE GFS NOW HAS ANOTHER CLOSED LOW DROPPING ON THE CNTRL ROCKIES...WHILE THE ECMWF JUST HAS WLY FLOW. WILL MAINTAIN CURRENT FORECAST. METZE && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 10 AM THIS MORNING TO 8 PM MST THIS EVENING FOR COZ221-COZ222-COZ225-COZ226-COZ227-COZ228-COZ229- COZ230-COZ231-COZ232-COZ233-COZ234-COZ235-COZ236-COZ237. && $$ 23/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 233 PM CST WED MAR 15 2006 .DISCUSSION... DAYS 1-2... MAIN FORECAST CHALLENGE WILL BE THE WIND ADVISORY FOR LATE THIS AFTERNOON. THE UPPER AIR ANALYSIS FROM 12Z SHOWED A VIGOROUS SHORTWAVE TROUGH OVER THE GREAT BASIN AND SOUTHWEST...HEADING EAST AT A RAPID CLIP. THE SURFACE LOW DEEPENING OVER NORTHEAST COLORADO HAD RESULTED IN A FAIRLY TIGHT PRESSURE GRADIENT ACROSS MUCH OF KANSAS. WINDS ACROSS ALL BUT THE WESTERN SECTIONS OF THE DDC CWA HAVE BEEN WELL INTO ADVISORY CRITERIA THROUGH MUCH OF THE DAY. SHORT RANGE MODEL SOLUTIONS FROM THE NAM AND RUC SHOW THE SURFACE LOW KICKING OUT INTO WESTERN KANSAS LATE THIS AFTERNOON AND INTO NORTH CENTRAL KANSAS BY MIDNIGHT. THINK THAT THE STRONG WINDS WILL BE DIMINISHING SOMEWHAT TOWARD SUNSET. WITH THAT IN MIND, WILL LEAVE THE ADVISORY INTACT AND LET IT EXPIRE AT 6 PM. AS THE SURFACE LOW MOVES OUT, THE TRAILING COLD FRONT SHOULD BE ENTERING THE NORTHWESTERN SECTIONS OF THE CWA AROUND 03-04Z AND BE EXITING THE SOUTHEAST BY AROUND 09Z. WINDS WILL STAY UP SOMEWHAT TONIGHT IN SPITE OF THE CLEAR SKIES. OVERNIGHT LOW TEMPERATURES SHOULD GENERALLY STAY IN THE 30S, UNLESS A FEW AREAS DECOUPLE EVEN MORE TOWARD DAWN. THURSDAY SHOULD BE A SUNNY DAY BUT COOLER. 850 MB TEMPERATURES WILL BE IN THE SINGLE DIGITS WHICH CORRESPONDS TO HIGHS GENERALLY IN THE 50S. COULD BE A FEW LOCATIONS BREAKING 60 DEGREES GIVEN THE HIGHER SUN ANGLES OF LATE. FRIDAY WILL SEE INCREASING CLOUDS AS UPPER LEVEL CIRRUS THICKENS IN ADVANCE OF THE NEXT SYSTEM DIGGING INTO THE WESTERN CONUS. LOW LEVEL MOISTURE WILL BE SLOWLY RETURNING TO SOUTHWEST KANSAS THROUGH THE DAY. WILL PROBABLY SEE SOME HIGHER STRATOCU DECKS DEVELOPING AS A FAVORABLE ISENTROPIC LIFT AREA WILL BE IN PLACE. PREVIOUS FORECAST HAD A SLIGHT CHANCE FOR SHOWERS IN EASTERN SECTIONS OF THE CWA BY LATER IN THE AFTERNOON. NOT CONFIDENT THAT WE WILL SEE ANYTHING BEFORE SUNSET SO WILL GO WITH A DRY FORECAST DURING THE DAY. DAYS 3-7... NO MAJOR CHANGES WERE MADE TO THE EXTENDED FORECAST. THE MAJOR MODELS ALL AGREE WITH A STRONG SYSTEM APPROACHING THE SOUTHERN AND CENTRAL PLAINS BY EARLY NEXT WEEK. OF COURSE THERE ARE THE USUAL SLIGHT DIFFERENCES IN TIMING AND LOCATION. THE GFS IS COLDER WHILE THE EC IS WARMER. THIS IS A TYPICAL MODEL BIAS AND THE TRUTH MAY LIE SOMEWHERE IN BETWEEN. AHEAD OF THE SYSTEM, WARM ADVECTION PRECIP WILL DEVELOP FRIDAY NIGHT. THERE WILL BE CHANCES FOR PRECIP UNTIL THE SYSTEM PASSES MONDAY OR TUESDAY. THERE IS A CHANCE THAT THE PRECIP MAY PICK UP IN INTENSITY JUST AHEAD OF THE MAIN SYSTEM. THE PRECIP TYPE WILL BE MAINLY RAIN THROUGH SUNDAY SINCE 800-700MB TEMPS WILL BE JUST ABOVE FREEZING. THERE COULD BE A CHANGEOVER TO SNOW IF THE SOUTHERN SOLUTION OF THE SFC-850MB LOW VERIFIES. LOWS WILL BE HELD UP BY CLOUDS AND WIND WHILE HIGHS WILL BE KEPT DOWN. A SLUG OF COLD AIR WILL PUSH SOUTH BEHIND THE SYSTEM INTO TUESDAY AND WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... DDC 34 59 29 48 / 0 0 0 0 GCK 31 58 30 51 / 0 0 0 0 EHA 32 59 33 52 / 0 0 0 0 LBL 35 61 31 52 / 0 0 0 0 HYS 33 56 27 46 / 0 0 0 0 P28 37 63 28 49 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR KSZ030-KSZ031- KSZ043-KSZ044-KSZ045-KSZ046-KSZ062-KSZ063-KSZ064-KSZ065-KSZ066- KSZ075-KSZ076-KSZ077-KSZ078-KSZ079-KSZ080-KSZ081-KSZ085-KSZ086- KSZ087-KSZ088-KSZ089-KSZ090. && $$ FN02/24 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 400 PM EST WED MAR 15 2006 .DISCUSSION... MAIN FCST CONCERNS ARE LES CHANCES TONIGHT INTO THE WEEKEND ALONG WITH TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPR LVL RDGING INTO WRN MN BTWN A CUTOFF LOW OVER THE ST LAWRENCE VALLEY AND VIGOROUS UPSTREAM SHRTWV TROF OVER THE CNTRL ROCKIES. AT THE SFC...A RDG EXTENDED FROM MANITOBA THROUGH THE UPR MS VALLEY AHEAD OF LOW PRES DEVELOPING OVER THE HIGH PLAINS. MID HIGH CLOUDS WITH 295K-305K ISENTROPIC LIFT AHEAD OF THE LOW HAS SPREAD FROM SRN MN INTO WRN WI. OTHERWISE...CONFLUENT/CONVERGENT MID/UPR LVL FLOW...QVECTOR DIV AND SUBSIDENCE OVER THE UPR GRT LAKES HAS BROUGHT MOSTLY SUNNY SKIES TO UPR MI WITH ONLY SCT LAKE EFFECT CLOUDS OVER THE ERN CWA WITH LINGERING NW FLOW. 17Z KSAW TAMDAR SNDG SHOWED A VERY DRY PRFL WITH AN 8C DEWPOINT DEPRESSION AT THE -12C 880 MB (3K FT) INVERSION. DECENT BNDRY LYR MIXING HAS DROPPED UPSTREAM SFC DEWPOINTS TO NEAR 0 F. TONIGHT...COLD AIR WILL BE MARGINAL TO SUPPORT LAKE CLOUDS AND FLURRIES WITH 900-850 MB TEMPS EXPECTED TO REMAIN NEAR -10C. INCREASINGLY ACYC FLOW OVER OVER THE WEST WILL ALSO BE UNFAVORABLE FOR ANY CLOUDS/--SHSN. SATELLITE TRENDS AND NAM/GFS 600-400 MB RH SUGGEST INCREASE IN MID/HIGH CLOUDS WILL BE MAINLY ALONG THE WI BORDER. THIS WILL LEAVE GOOD RADIATIONAL COOLING CONDITIONS. HOWEVER...AS WINDS VEER NNE AND EFFECTS OF UPSTREAM MIXING/DRYING DIMINISH...SOME LAKE CLOUDS AND FLURRIES MAY DEVELOP FROM N CNTRL UPR MI EASTWARD. THU...AS THE PLAINS SFC LOW MOVES TOWARD INDIANA...THE MANITOBA RDG WILL BUILD INTO THE UPR MS VALLEY WITH LOW LVL WINDS GRADUALLY BACKING TO THE NORTH. ACYC FLOW AND 900-850 MB TEMPS TO NEAR -12C WILL AGAIN SUPPORT LITTLE MORE THAN SCT-BKN CLOUDS WITH A CHANCE OF FLURRIES OVER THE NORTH HALF. ONLY SLGT CHANCE POPS WERE RETAINED NEAR MNM AS THE MDLS WERE CONSISTENT IN KEEPING BULK OF PCPN ASSOCIATED WITH THE ROCKIES/PLAINS MID LVL SHRTWV WELL S OF THE CWA. THU NIGHT...WEAK CAA WILL BRING IN SLIGHTLY COLDER AIR AS THE HIGH CONTINUES TO BUILD INTO THE AREA. GIVEN CONTINUING ACYC LOW LVL INTO THE AREA WITH QG FORCING FROM WRN ONTARIO H5 LOW REMAINING N OF LK SUPERIOR...FCST LEANED TOWARD NAM/UKMET/ECMWF SCENARIO WHICH SUGGESTS LOWER INVERSION HGTS AND SLIGHTLY WARMER 850 TEMPS THAN THE GFS. SO...ONLY LOWER END POPS WERE MENTIONED OVER THE NORTH. FRI INTO FRI NIGHT...MID MARCH DIURNAL WARMING/MIXING AND PERSISTENT DRY PRFL AND INVERSION HGTS NO MORE THAN NEAR 3K-4K FT WILL LIMIT LES CHANCES EVEN AS 850 MB TEMPS FCST TO NEAR -14C. LAKE CLOUDS WILL AGAIN KEEP TEMPS FROM FALLING OFF TOO MUCH OVERNIGHT EXCEPT FOR INLAND LOCATIONS OVER THE SOUTH. SAT-WED...GLBL MDLS WERE IN REASONABLE AGREEMENT THAT BLOCKING PATTERN WILL ONLY GRADUALLY SHIFT WITH THE SFC RDG BUILDING INTO THE UPR LAKES THROUGH MON KEEPING FLOW OF VERY DRY AIR GOING FROM ONTARIO. REMAINING LES SHOULD FADE SAT AS THE H8 TROF SHIFTS TO THE EAST. MDLS SPREAD INCREASES SIGNIFICANTLY BY MIDWEEK BUT EFFECTS ON WEATHER OVER UPR MI WILL BE MINIMAL. POTENTIAL FOR ADDITIONAL MOISTURE AND SHRTWV ENERGY AROUND ERN CANADA TROF WAS DELAYED TIL WED...PER GFS TRENDS AND 00Z GFS ENS MEAN. && .MQT...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 307 PM CST WED MAR 15 2006 .DISCUSSION...TONIGHT THROUGH SATURDAY NEXT SHORTWAVE OF INTEREST IS CURRENTLY VISIBLE ON AFTERNOON WATER VAPOR IMAGERY NEAR THE FOUR CORNERS REGION. ASSOCIATED SURFACE CYCLOGENESIS IS OCCURRING ACROSS THE HIGH PLAINS. THE GFS AND NAM ARE IN DECENT AGREEMENT IN DRIVING THE RELATED 700MB LOW ACROSS MN/IA...WITH SURFACE LOW PROGRESSION ACROSS SOUTHERN IOWA. THIS PLACES THE ASSOCIATED HEAVY SNOW POTENTIAL ACROSS THE SOUTHERN CWA. WHILE DECENT ISENTROPIC LIFT ON THE 290K SURFACE INITIATES BY 00Z...ANTICIPATE THAT IT WILL TAKE A FEW HOURS FOR ADVECTION PROCESSES TO PROVIDE ADEQUATE SATURATION FOR ACCUMULATING SNOW. THIS IS SUPPORTED BY RUC CROSS SECTIONS AND BUFKIT PROFILES WHICH EXHIBIT A DRY WEDGE AROUND 850MB UNTIL LATER THIS EVENING. HAVE THEREFORE DELAYED THE WINTER STORM WARNING UNTIL 9 PM TONIGHT. ONCE SATURATION OCCURS...A NORTHWEST TO SOUTHEAST CORRIDOR OF STRONG ISENTROPIC LIFT IS FORECAST ON THE 290K SURFACE...WHERE SPECIFIC HUMIDITY VALUES ARE AROUND 3 J/KG. ADDITIONAL CONFIRMATION FROM DECENT Q VECTOR CONVERGENCE ACROSS THE SOUTHERN CWA. HAVE PLACED THE HIGHEST SNOWFALL AMOUNTS /6-8 INCHES/ GENERALLY ALONG THE MINNESOTA RIVER VALLEY FROM GRANITE FALLS TO MANKATO. AMOUNTS SHOULD TAPER OFF DRAMATICALLY ALONG THE NORTHERN EDGE OF THE WARNING AREA. WILL ALSO HAVE SOME BRISK WINDS...SO BLOWING/DRIFTING MAY OCCUR. THE LOW SHIFTS EAST/SOUTH ON THURSDAY AFTERNOON...SO ONLY HAVE FLURRIES MENTIONED THURSDAY EVENING ACROSS THE SOUTHEAST. A RIDGE OF HIGH PRESSURE BUILDS IN FOR FRIDAY AND FRIDAY NIGHT...WHICH WILL SET THE STAGE FOR CHILLY CONDITIONS ON FRIDAY NIGHT. LONGER TERM...SATURDAY NIGHT THROUGH WEDNESDAY UPPER LEVEL BLOCKING PATTERN OVER THE REGION THIS WEEKEND WITH A DEEP CLOSED LOW PRESSURE SYSTEM OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN STATES. ECMWF...CNDN...UKMET...OPERATIONAL GFS AND GFS ENSEMBLE...ALL SHOW THE SW SYSTEM AS ONLY SLOWLY APPROACHING THE PLAINS...WITH SHARP RIDGING ACROSS MN/WI ON SUNDAY. HOWEVER...THE UK AND CNDN MODELS ARE SOMEWHAT FASTER. WE MIGHT EVEN WIND UP ON THE NORTHERN FRINGE OF PRECIPITATION AS THERE ARE SOME HINTS THAT THE SHORT WAVE MIGHT TRAVEL MOSTLY EAST AS THE NEXT WAVE APPROACHES THE WEST COAST EARLY NEXT WEEK. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WARNING FROM 9 PM THIS EVENING TO 12 PM CST THURSDAY FOR ANOKA-BLUE EARTH-BROWN-CARVER-CHIPPEWA-DAKOTA- FARIBAULT-HENNEPIN-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT- SIBLEY-SWIFT-WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE COUNTIES. WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 PM CST THURSDAY FOR FREEBORN-GOODHUE-STEELE COUNTIES. WI...WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 PM CST THURSDAY FOR CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-ST. CROIX COUNTIES. && $$ LS/TDK mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 337 AM MST WED MAR 15 2006 .SHORT TERM...VALID FOR TDY AND THU... VERY CHALLENGING FORECAST TODAY DEALING WITH A MODERATELY STRONG WAVE...BUT FAIRLY PROGRESSIVE...CURRENTLY PUSHING INTO AREA. LATEST SATELLITE TRENDS SHOWING SYSTEM CONTINUES TO STRENGTHEN WITH A NICE PLUME OF MOISTURE ACROSS EASTERN IDAHO JUST NOW PUSHING INTO SOUTHWEST MONTANA. RADAR RETURNS SHOWING BULK OF RETURNS IN EASTERN IDAHO AS WELL. FOR FORECAST...INITIALLY WEIGHED HEAVILY ON 00Z GFS...WHICH WAS MUCH WETTER AND STRONGER THAN 00Z NAM. THIS SCENARIO TAKES 700 MB LOW ACROSS NORTHERN WYOMING WITH A QUICK...BUT GOOD SHOT OF MOISTURE ACROSS MAINLY SOUTHERN ZONES...WITH BILLINGS RECEIVING SOME MOISTURE BUT NOT MUCH. HOWEVER...LATEST RUNS OF RUC...NAM AND GFS SHOWING WAVE REALLY WRAPPING UP AND TURNING NEGATIVE...WITH NAM ACTUALLY DRY SLOTTING SOUTHEAST ZONES...PUSHING BEST MOISTURE FURTHER NORTH AND WEST. ALSO SLOWING THE SYSTEM DOWN EVENTUALLY CLOSING OFF AT 500 MB IN WESTERN NORTH DAKOTA. NEW 06Z GFS JUST IN AND IS BASICALLY A BLEND OF THE NEW NAM AND IT'S OLD SELF WHICH SEEMS TO BE BEST SOLUTION. WITH THIS IN MIND WILL BE SPREADING HIGHER POPS FURTHER NORTH AND WEST AND INCREASE SNOW AMOUNTS AS WELL TO THE WEST AND NORTH. LOOKING AT LATEST TIME HEIGHTS WILL BE A ABOUT 6 HOURS OF MODERATE LIFT IN WEST AND CENTRAL ZONES STARTING LATER THIS MORNING. TIME HEIGHTS FOR BILLINGS AREA SHOWING GOOD LIFT AND IN GOOD DENDRITIC LAYER...SO THINK 2 INCHES IS POSSIBLE. IN EASTERN ZONES...SAME SCENARIO...BUT SYSTEM HANGS ON A BIT LONGER INTO EARLY THIS EVENING...POSSIBLY PICKING UP ANOTHER INCH THERE. BIG HORN ALSO LOOK TO GET A GOOD SHOT OF NORTHERLY FLOW THIS AFTERNOON AND THINK SNOW ADVISORY CRITERIA WILL BE POSSIBLE THERE. WILL GO AHEAD AND PUSH OUT A WINTER WEATHER ADVISORY FOR MOST OF THE COUNTY WARNING AREA FOR TODAY...INTO EARLY THIS EVENING IN THE EAST FOR A GENERAL 2 TO 4 INCH ACCCUMULATION OF SNOW. SYSTEM SHOULD BE OUT OF THE AREA AFTER 06Z TONIGHT. THURSDAY...UPPER LEVEL SHORT WAVE RIDGE BUILDS INTO AREA. EASTERLY FLOW HANGS ON IN THE EAST FOR COOL TEMPERATURES THERE...BUT SOME SOUTHWEST WINDS IN WEST AND CENTRAL FOR TEMPERATURES GENERALLY IN THE 40S. RASCH .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... WEEKEND CONTINUES TO LOOK WET AND COOL. ECMWF A LITTLE SLOWER EVOLUTION THAN GFS AND SYSTEM MAY STILL DIG FURTHER SOUTH THAN ADVERTISED...BUT CONFIDENCE STILL HIGH FOR PCPN INTO OUR AREA AS BAROCLINIC ZONE AND GOOD SOUTHEAST MOISTURE FETCH SET UP OVER FORECAST AREA. OVERALL SYNOPTIC PATTERN SOMEWHAT SIMILAR TO LAST WEEKEND EXCEPT WITH BETTER MOISTURE WITH LOW LEVEL EASTERLY FLOW OVER MUCH OF AREA AND SOUTHERLY DIFFLUENT FLOW ALOFT. BASED ON THIS...BOOSTED POPS TO LIKELY IN SOUTHEAST ZONES SATURDAY AND LOWERED FORECAST HIGHS AS FEEL MERCURY WILL HAVE A HARD TIME MAKING HEADWAY IN MOST AREAS. INITIAL WAVE PROGGED TO HIT SATURDAY. SECOND WAVE LATE SUNDAY THRU SUNDAY NIGHT MAINLY EASTERN ZONES WITH LIGHT SNOW PERSISTING INBETWEEN. GFS INCONSISTENT FOR EARLY NEXT WEEK. HOWEVER...ECMWF LINGERS UPPER LOW OVER SOUTHERN ROCKIES INTO EARLY NEXT WEEK...SO WARY THAT PERIODS OF LIGHT SNOW COULD LAST LONGER. NEXT FEW SHIFTS WILL NEED TO WATCH THIS TREND AND ADJUST ACCORDINGLY. TESAR && .AVIATION... A PACIFIC STORM SYSTEM WAS APPROACHING SOUTHERN MT EARLY THIS MORNING. THIS SYSTEM WILL SPREAD AREAS OF SNOW INTO THE CRAZY/BEARTOOTH/ABSAROKA MOUNTAINS BETWEEN MAINLY 12Z AND 18Z AND INTO THE BIG HORNS VICINITY FROM 15Z TO 00Z. THUS CONDITIONS OVER THE MOUNTAINS WILL DETERIORATE TO LIFR/IFR THRU THE MORNING AND IMPROVE FROM WEST TO EAST IN THE EVENING. AS FOR THE PLAINS...RAIN AND SNOW IS EXPECTED TO REACH MAINLY THE CENTRAL AND EASTERN ZONES AFTER 15Z TODAY SPREADING EASTWARD AND THEN ENDING IN ALL BUT THE FAR EAST THIS EVENING. AREAS OF MVFR/IFR CAN BE EXPECTED WITH SOME AREAS NEAR HIGHER TERRAIN DOWN TO LIFR CONDITIONS. THE BEST CHANCE FOR LIFR CONDITIONS WILL BE BETWEEN KBIL AND KSHR AND OVER SE MT LATER TODAY. THIS WILL BE A FAST MOVING SYSTEM AND CONDITIONS MAY CHANGE RAPIDLY. BE SURE TO CHECK LOCAL TAF AND TWEB PRODUCTS FOR DETAILS. TESAR && .PRELIMINARY POINT TEMP/POPS... TDY THU FRI SAT SUN MON TUE ------------------------------------------------------- BIL 035 021/049 022/046 024/037 020/034 021/038 022/041 8/O 00/B 00/B 25/O 53/S 42/J 20/B LVM 038 020/048 018/045 021/038 018/037 017/039 017/042 4/S 00/B 00/B 35/S 54/S 43/J 30/B HDN 034 019/050 019/048 023/039 018/035 018/038 020/042 9/O 10/B 00/B 25/O 53/S 42/J 20/B MLS 035 019/043 019/041 022/036 018/032 018/036 019/039 8/S 60/B 00/B 25/S 43/S 32/J 20/B 4BQ 034 015/042 016/043 023/032 019/035 019/036 019/038 +/S 30/B 00/B 36/S 55/S 52/J 20/E BHK 030 017/034 013/031 019/029 014/027 017/031 016/033 8/S 60/B 00/N 24/S 44/S 42/J 20/E SHR 034 013/045 013/043 024/037 021/035 015/037 017/041 +/S 00/B 00/B 36/O 55/S 53/J 30/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WINTER WEATHER ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ZONES 29>31-34-35-38-39-42-56>58-66. WINTER WEATHER ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO 11 PM MST THIS EVENING FOR ZONES 32-33-36-37. WY...WINTER WEATHER ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ZONE 99. SNOW ADVISORY IN EFFECT FROM 8 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ZONE 98. && $$ WEATHER.GOV/BILLINGS mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC ISSUED BY NATIONAL WEATHER SERVICE WAKEFIELD VA 948 AM EST WED MAR 15 2006 .SHORT TERM /REST OF TODAY/... CURRENT FORECAST IS ON TRACK. CURRENT THICKNESSES AND RUC INDICATE TEMPERATURES A LITTLE COOLER THEN A CURRENT FCST. WILL LOWER MAXES A LITTLE. DEWPOINTS ARE QUITE LOW AND LOOK GOOD IN CURRENT FCST. WINDS LOOK GOOD LOOKING AT CURRENT SOUNDINGS AND MIX DOWN OF STRONGER WINDS. && .PREV DISCUSSION... /ISSUED 219 AM EST WED MAR 15 2006/ PUBLIC...DRY WEST NORTHWEST FLOW ACROSS THE REGION TODAY WITH LOW DEWPOINTS GIVES THE FORECAST AREA...MINUS THE OUTER BANKS... AFTERNOON HUMIDITY VALUES BELOW 25 PERCENT. THIS COMBINED WITH THE FORECAST WIND SPEEDS JUSTIFIES CONTINUING THE RED FLAG WARNING. THE SURFACE RIDGE OVER THE GULF STATES TODAY WILL MOVE OFF THE SOUTHEAST COAST ON THURSDAY WITH WINDS BACKING TO SOUTHWEST AHEAD OF THE NEXT SYSTEM. THE SURFACE LOW WILL PASS TO OUR NORTH THURSDAY NIGHT WITH ONLY MID AND HIGH CLOUDS ASSOCIATED WITH IT. FORECAST SOUNDINGS AND TIME SECTIONS SHOW VERY DRY IN THE LOW LEVELS SO I REMOVED THE SLIGHT CHANCE POPS. THE DRY WEATHER WILL CONTINUE INTO THE WEEKEND AND EARLY NEXT WEEK AS HIGH PRESSURE OVER SOUTH CENTRAL CANADA EXTENDS INTO THE CAROLINAS. THE GFS IS TRYING TO DEVELOP A LOW AND TRACK IT ALONG THE COAST ON TUESDAY. SINCE THIS IS NEARLY A WEEK AWAY AND HIGHLY UNCERTAIN WILL LEAVE 20 PERCENT POPS NEXT WEEK AS IS. AVIATION...WITH HIGH PRES BUILDING IN FROM THE NW EXPECT VFR CONDITIONS THROUGH THE NEXT 24 HOURS. WINDS MAY GUST INTO THE MID 20S THROUGH THE DAYTIME HOURS. MARINE...SURGE OF COLDER AIR CONTINUES OVER COASTAL WATERS THIS MRNG BUT SHOULD BE DECREASING IN INTENSITY THROUGH THE DAY. MODELS APPEAR TO HAVE CAPTURES THIS FAIRLY WELL AND WILL USE A MIX OF NAM AND GFS WINDS THROUGH EARLY FRI WITH WW3 WAVE GUIDANCE LOOKING REASONABLE. WILL EXTEND SCA FOR MOST OF THE COASTAL WATERS INTO LATE TONIGHT. CURRENTLY BUOY 41025 SHOWING HIGHEST WINDS AND SEAS WITH OCCASIONAL GUSTS TO 35 KT. THIS SHOULD GRADUALLY DECREASE. GIVEN OFFSHORE WINDS NEAR SHORE SEAS ARE GOING TO BE A BIT LESS THAN THOSE BEHIND A FEW MILES SO WILL NEED TO ADD NEAR SHORE WORDING SOME AREAS. AS HIGH SLIPS OVER THE RGN THURSDAY WILL SEE FAIRLY LIGHT WINDS AND SEAS 4 FT OR LESS ALL AREAS. MODELS SHOW NEXT SYSTEM MOVING THROUGH QUICKLY FRI WITH AN INCREASE IN WINDS AND SEAS JUST AHEAD OF SYSTEM THEN ANOTHER SURGE OF COLD AIR FOR EARLY SAT. DUE TO QUICK MOVEMENT OF THE SYSTEM WILL NOT HAVE TIME FOR SEAS TO BUILD AS MUCH AS SCA WINDS WOULD NORMALLY ALLOW. HAVE HAD TO MAKE SOME ADJUSTMENTS TO WW3 GUIDANCE TO REFLECT THIS. SURGE BEHIND THE SYSTEM LASTS THROUGH EARLY SAT THEN A SECONDARY NRLY SURGE DEVELOPS FOR SUN AS HIGH BUILDS IN FROM THE NW. MHX WATCHES/WARNINGS/ADVISORIES... NC...RED FLAG WARNING FOR NCZ029-044>047-079>081-090>095-098 FROM 9 AM WEDNESDAY TO 6 PM WEDNESDAY. MARINE...SMALL CRAFT ADVISORY FOR AMZ130 UNTIL 5 PM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR AMZ135 UNTIL 10 PM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR AMZ150-156 UNTIL 1 AM THURSDAY. ...SMALL CRAFT ADVISORY FOR AMZ152-154 UNTIL 6 AM THURSDAY. ...SMALL CRAFT ADVISORY FOR AMZ158 UNTIL 7 PM WEDNESDAY. $$ && .MHX WATCHES/WARNINGS/ADVISORIES... NC...RED FLAG WARNING FOR NCZ029-044>047-079>081-090>095-098 UNTIL 6 PM WEDNESDAY. MARINE...SMALL CRAFT ADVISORY FOR AMZ130 UNTIL 5 PM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR AMZ135 UNTIL 10 PM WEDNESDAY. ...SMALL CRAFT ADVISORY FOR AMZ150-156 UNTIL 1 AM THURSDAY. ...SMALL CRAFT ADVISORY FOR AMZ152-154 UNTIL 6 AM THURSDAY. ...SMALL CRAFT ADVISORY FOR AMZ158 UNTIL 7 PM WEDNESDAY. && $$ SHORT TERM... nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 912 PM CST WED MAR 15 2006 .UPDATE...NARROW BAND OF SNOW CONTINUES ACROSS EXTREME SOUTHEAST ND AS FAR NORTH AS JAMESTOWN/VALLEY CITY AND THROUGH FFM AND OTTER TAIL COUNTY MN BUT NOT YET QUITE TO FARGO. IT IS ONLY 15-20 MILES FROM FARGO BUT SYSTEM IS ENTRAINING VERY DRY AIR FROM THE NORTH AND THEY MAY ONLY GET A SKIFF. A COUPLE OF INCHES HAS APPARENTLY BEEN THE MAX SNOWFALL UNDERNEATH THE SNOW BAND BUT THERE MAY BE A COUPLE MORE WHERE THE BAND DRIFTS TO. A LITTLE FARTHER NORTH...THE DRY AIR WILL PREVENT ANY SNOW TONIGHT AND HAVE REMOVED ITS MENTION FROM FORECASTS. WEAK ISENTROPIC LIFT ON 285K SURFACE WILL CONTINUE ACROSS SOUTH OF FARGO THROUGH THE NIGHT BUT EASILY THE BEST LIFT HAS ALREADY MOVED SOUTH OF THE STATE AS EVIDENCED BY THE BETTER RETURNS DEVELOPING OVER ROBERTS COUNTY SD. WARM ADVECTION AND CLOUDS INTO WEST CENTRAL MN HAVE KEPT TEMPERATURES WELL INTO THE 20S THERE (ALONG WITH SOME SERIOUS TEMP/DEW POINT DEPRESSIONS) BUT HCO IS ALREADY APPROACHING ZERO. MADE SOME ADJUSTMENTS TO TEMPS IN UPDATE AND RELIED ON RUC QUITE A BIT. && .PREV DISCUSSION... (ISSUED ISSUED BY NATIONAL WEATHER SERVICE BISMARCK ND) SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT MAIN FOCUS IN THE SHORT TERM IS CURRENT STORM SYSTEM...LOW PRESSURE CURRENTLY EXTENDS FROM EASTERN WYOMING TO WESTERN NEBRASKA. THIS SYSTEM IS PROGGED TO DEEPEN AND DEVELOP SOUTHEASTWARD OVER NEBRASKA/KANSAS. TODAY'S MODELS ARE KEEPING MOST OF THE PRECIPITATION A BIT FARTHER SOUTH THAN YESTERDAY'S MODELS...BUT FEEL SOUTHERN PORTIONS OF FORECAST AREA WILL GET SNOW ACCUMULATIONS...PERHAPS 1 TO 3 INCHES. GFS MODEL IS NOT AS AGGRESSIVE AS THE NAM WITH BRINGING THE PRECIPITATION NORTHWARD..BUT BOTH MODELS INDICATE ISENTROPIC LIFTING TONIGHT AND THURSDAY MORNING...WITH CONDENSATION PRESSURE DEFICITS RAPIDLY LOWERING TO VALUES OF 10 AND 20 MB AFTER 00Z TONIGHT. SURROUNDING RADAR RETURNS INDICATE MID LEVEL CLOUDS WITH VIRGA...AND THINK THAT AS TIME PROGRESSES TONIGHT THE ATMOSPHERE WILL REACH SATURATION AND PRECIPITATION WILL REACH THE GROUND. THINK MOST OF THE ACTIVITY WILL AFFECT THE SOUTHERN PORTION OF THE FORECAST AREA LATE THIS EVENING THROUGH DAYBREAK FRIDAY. AFTER DAYBREAK THE STORM CENTER IS FORECAST TO BE OVER IOWA...MOVING TO ILLINOIS BY AFTERNOON AND KEEPING MUCH OF THE NORTHERN PART OF THE FORECAST AREA ON THE DRY SIDE. THURSDAY NIGHT THROUGH SATURDAY THE REGION IS DOMINATED BY AN ARCTIC/CANADIAN SURFACE HIGH WITH THE UPPER LEVEL HUDSON BAY LOW MOVING GRADUALLY SOUTHEASTWARD. THIS WILL KEEP THE AREA DRY BUT ON THE COLD SIDE. LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT ON SUNDAY THE FORECAST AREA IS UNDER A WEAK UPPER LEVEL RIDGE BETWEEN THE EXITING HUDSON BAY LOW TO THE EAST AND A DEVELOPING LOW/TROUGH OVER THE WESTERN CONUS. THE WESTERN STORM SYSTEM MOVES OVER THE ROCKIES ON SUNDAY...AND BY SUNDAY NIGHT AND MONDAY SOUTHERN PORTIONS OF THE RED RIVER VALLEY WILL HAVE ANOTHER CHANCE OF SNOWFALL. THE MODELS MOVE THE TRACK OF THIS SYSTEM ACROSS THE CENTRAL PLAINS TO THE OHIO VALLEY...AND HINTS THAT THE CANADIAN SURFACE HIGH MAY KEEP THE REGION OUT OF THE PATH OF MOST PRECIPITATION. KEPT TUESDAY AND WEDNESDAY DRY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ GV nd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NORMAN OK 1014 AM CST WED MAR 15 2006 .UPDATE... WINDS HAVE INCREASED THIS MORNING WITH SEVERAL MESONET SITES ALREADY GUSTING ABOVE 40 MPH. PROFILERS SHOWING 50 KT WINDS ABOVE SFC IN WESTERN OK THIS MORNING. MODELS SHOWING AREA OF HIGHER WINDS ALOFT SHIFTING EASTWARD AND FURTHER SOUTH. WITH MIXING EXPECT WINDS TO BE HIGHER THAN PREVIOUSLY FORECASTED IN SOME AREAS... SO HAVE EXPANDED WIND ADVISORY SOUTH AND EAST TO INCLUDE SW OK AND PARTS OF CENTRAL OK. RED FLAG WARNING FOR ENTIRE AREA LOOKS TO BE ON TRACK. HAVE LOWERED DEWPTS A FEW DEGREES TODAY BY USING RUC NUMBERS WHICH WILL HAVE MINIMUM RH LESS THAN 20 PERCENT ACROSS MUCH OF THE FA. TEMPS LOOK TO BE ON TRACK...EXCEPT FOR SE WHERE HAVE RAISED A FEW DEGREES. WILL SEND UPDATES TO USUAL PRODUCTS AND WIND ADVSY/RED FLAG WARNING AS SOON AS POSSIBLE. MAXWELL && .PREV DISCUSSION... (ISSUED 345 AM CST WED MAR 15 2006) DISCUSSION... WIND WILL BE MAIN WEATHER FEATURE TODAY AS SURFACE LOW DEEPENS ACROSS NORTHEAST COLORADO IN RESPONSE TO APPROACHING SYSTEM. WILL ISSUE WIND ADVISORY FOR NORTHWEST PART FA WHERE MIXING WINDS WILL BE IN THE 40 TO 50 KT RANGE. WILL ALSO CONTINUE WITH RED FLAG WARNING FOR ENTIRE FA. RUC AND NAM SURFACE DEWPOINTS DIFFER BY 10 TO 15 DEGREES BY 18Z OVER WESTERN 2/3RDS OF AREA AND EXPECT RUC MAY BE CLOSER TO WHAT OCCURS. THEREFORE...HUMIDITY LEVELS AT OR BELOW 20 PERCENT SEEM LIKELY. SURFACE LOW TO THE NORTH WILL HELP PUSH A COLD FRONT ACROSS THE SOUTHERN PLAINS LATE TONIGHT INTO EARLY PART OF THURSDAY. COULD SEE RAIN/ELEVATED STORMS DEVELOP DURING THE FIRST PART OF FRIDAY NEAR ELEVATED FRONTAL ZONE OVER NORTH TEXAS WITH BEST CHANCES FOR RAIN/EMBEDDED THUNDER OVER THE WEEKEND. DIFFERENCES WITH TIMING BETWEEN GFS AND ECMWF...SO WILL NOT MAKE MANY CHANGES TO OVERALL FORECAST DAY 5-7. WILL NOT INTRODUCE WINTER PRECIP AT THIS TIME BUT COULD SEE SNOW OR RAIN/SNOW MIX ACROSS NORTHWEST DURING THE EARLY PART OF NEXT WEEK AS MAIN SYSTEM LIFTS ACROSS THE SOUTHERN PLAINS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 70 43 65 36 / 0 0 10 10 HOBART OK 71 43 66 36 / 0 0 10 10 WICHITA FALLS TX 73 45 69 38 / 10 10 10 10 GAGE OK 71 35 61 31 / 0 0 10 10 PONCA CITY OK 69 40 64 31 / 0 0 10 10 DURANT OK 70 53 69 40 / 10 20 20 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...RED FLAG WARNING UNTIL 7 PM CST THIS EVENING FOR OKZ004-OKZ005- OKZ006-OKZ007-OKZ008-OKZ009-OKZ010-OKZ011-OKZ012-OKZ013- OKZ014-OKZ015-OKZ016-OKZ017-OKZ018-OKZ019-OKZ020-OKZ021- OKZ022-OKZ023-OKZ024-OKZ025-OKZ026-OKZ027-OKZ028-OKZ029- OKZ030-OKZ031-OKZ032-OKZ033-OKZ034-OKZ035-OKZ036-OKZ037- OKZ038-OKZ039-OKZ040-OKZ041-OKZ042-OKZ043-OKZ044-OKZ045- OKZ046-OKZ047-OKZ048-OKZ050-OKZ051-OKZ052. WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR OKZ018-OKZ023- OKZ024-OKZ027-OKZ033-OKZ034-OKZ035-OKZ036-OKZ037-OKZ038. WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR OKZ004-OKZ005- OKZ006-OKZ007-OKZ009-OKZ010-OKZ011-OKZ012-OKZ014-OKZ015- OKZ016-OKZ017-OKZ021-OKZ022. TX...RED FLAG WARNING UNTIL 7 PM CST THIS EVENING FOR TXZ083-TXZ084- TXZ085-TXZ086-TXZ087-TXZ088-TXZ089-TXZ090. && $$ 25/23 ok AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 815 PM MST WED MAR 15 2006 .DISCUSSION...03Z SURFACE ANALYSIS HAD LOW OVER CENTRAL NE WITH INVERTED TROUGH INTO SOUTHEAST MT. VIGOROUS COMPACT SHORTWAVE WINDING UP OVER KIEN. DEFORMATION ZONE PRECIPITATION SHIELD WELL DEFINED WITH NICE BURST OF SNOW FALLING. JUST GOT A REPORT OF THUNDERSNOW NEAR CUSTER...WITH LIGHTNING DETECTION NETWORK PICKING UP. DON/T EXPECT MENTIONABLE THUNDERSNOW WITH UPDATE...BUT SNOW IS DEFINITELY CONVECTIVE LOOKING PER RADAR RETURNS. SYSTEM WILL QUICKLY MOVE EAST OVERNIGHT...BRINGING ACCUMULATING SNOW TO AND END FROM WEST TO EAST. 00Z RUC SEEMS TO HAVE GOOD HANDLE ON THINGS...WHERE THE 12Z/18Z MODELS HAD SYSTEM FURTHER NORTH. UPDATE ALREADY OUT TO GO CATEGORICAL POPS FURTHER SOUTH AND SHIFT ACCUMULATIONS. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ HELGESON sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 300 PM MST WED MAR 15 2006 .DISCUSSION...CURRENT SURFACE ANALYSIS PLACES MAIN CENTER OF LOW PRESSURE OVER NORTHEAST COLORADO EDGING EASTWARD...WITH DEEP INVERTED TROF TO THE NORTH INTO NORTHEASTERN WYOMING/WESTERN SOUTH DAKOTA. WATER VAPOR CONTINUES TO SHOW AN INTENSE UPPER LEVEL WAVE PUSHING INTO THE WESTERN CWFA. AREA OF SNOW SHOWERS INDICATED ON RADAR CONTINUE TO PUSH THROUGH THE BLACK HILLS AS AFOREMENTIONED WAVE MOVES IN. FOR TONIGHT AFOREMENTIONED SURFACE LOW WILL DEEPEN AND MOVE EASTWARD INTO THE CENTRAL PLAINS. AS IT DOES...UPPER WAVE WILL BRIEFLY CLOSE OFF AS IT CROSSES THROUGH THE NORTHERN PLAINS. SNOW IS EXPECTED TO DEVELOP OVER NORTHERN PTNS OF CWFA WITH LOCALIZED AMOUNTS OF UP TO 3 INCHES. ALSO HAVE PUT SOME 3 INCH AMOUNTS OVER THE NORTHERN BLACK HILLS WHERE SOME UPSLOPE COMPONENT IS EXPECTED TO ENHANCE SNOWFALL. MAIN CONCERN AT THIS MOMENT IS THAT LATEST RUNS OF THE RUC HAVE PULLED THE CLOSING LOW SOMEWHAT SOUTH. WILL HAVE TO SEE HOW IT TRENDS THROUGH THE LATE AFTERNOON AND MAY HAVE TO DO SOME ADJUSTMENTS ON SNOWFALL AMOUNT. EXPECT THIS SYSTEM TO BE QUICK MOVING...AND BE GENERALLY OUT OF THE AREA BY TOMORROW MORNING. EXPECT QUIET WEATHER AS A BROAD RIDGE BUILDS OVER THE AREA FOR TOMORROW AFTERNOON INTO FRIDAY AHEAD OF NEXT SYSTEM THAT IS POSED TO MOVE INTO THE NORTHERN PLAINS. BY SATURDAY...DEEP UPPER TROF MOVES WELL INTO THE WESTERN CONUS SWITCHING FLOW TO THE SOUTHWEST AND OPENING THE DOOR FOR MULTIPLE WAVES TO PUSH ACROSS. HAVE UPPED POPS TO HIGH END CHANCE FOR MUCH OF CWFA FOR SAT INTO SAT NIGHT. EXTENDED...UPPER LEVEL SYSTEM OVER THE WESTERN CONUS LATE IN THE WEEKEND WILL SLOWLY MOVE EAST ACROSS THE PLAINS EARLY NEXT WEEK. STILL PLENTY OF UNCERTAINTY AS TO ITS TRACK FROM THE INTERMOUNTAIN WEST TO THE PLAINS...BUT RECENT RUNS OF GFS HAVE TRENDED THE SYSTEM A LITTLE FURTHER SOUTH. EVEN IF THIS SCENARIO ULTIMATELY PANS OUT...THE NORTHERN PLAINS SHOULD SEE SOME PCPN AS WEAKER DISTURBANCES MOVE ACROSS THE REGION. SO...WILL KEEP CHANCES FOR SNOW GOING IN THE EXTENDED FROM SUNDAY THROUGH TUESDAY...WITH BETTER CHANCES FOR MOST AREAS LIKELY BEING SUNDAY INTO MONDAY. TEMPS WILL REMAIN UNSEASONABLY COOL THROUGH THE PERIOD WITH HIGHS IN THE UPPER 20S AND 30S. SOME MILDER WX IS EXPECTED TO RETURN BY THE MIDDLE OF NEXT WEEK AS THIS SYSTEM SHIFTS EAST. && .AVIATION...CONDITIONS WILL CONTINUE TO DETERIORATE FROM WEST TO EAST LATE THIS AFTERNOON AND EVENING AS UPPER LEVEL TROF APPROACHES. MVFR/IFR CONDITIONS AND AREAS OF -SHRASN WILL DEVELOP BY LATE THIS AFT ACROSS TWEB ROUTES 259 AND 285...CHANGING TO ALL SNOW BY EVENING. SOME ISOLATED -TSRA HAVE ALSO DEVELOPED ACROSS ROUTE 285 THIS AFT. THESE CONDITIONS WILL SPREAD ACROSS TWEB ROUTES 258...260...AND 315 EARLY THIS EVENING. IFR CONDITIONS AND OCCASIONAL LIGHT SNOW WILL DEVELOP AT KGCC LATE THIS AFTERNOON AND AT KRAP AFTER 00Z. IFR CIGS ARE THEN EXPECTED AT EACH LOCATION THRU THE REMAINDER OF TONIGHT WITH SNOW ENDING AROUND 06Z. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 336 AM CST THU MAR 16 2006 .SHORT TERM...TODAY THROUGH SAT NIGHT MAIN EFFORT THIS MORNING OBVIOUSLY DEVOTED TO IMPENDING WINTER STORM. UPSTREAM PCPN AND OBS NOT TOO IMPRESSIVE OVERNIGHT...BUT RECENT RADAR TRENDS INDICATE THAT SYS IS BEGINNING TO COME TOGETHER. 06Z/00Z RUC/GFS RUNS LOOK GOOD AND ARE FAVORED BASED ON CURRENT PLACEMENT OF PCPN. SHRT WV DROPPING DOWN MO RIVER ACCOMPANIED BY STRONG QG FORCING IN DEF ZN. RECENT RUC ANLYS STILL SHOWS MUCAPES UP TO 100 J/KG FEEDING DEF ZN WHICH IS CONFIRMED BY TEXTURE OF RADAR ECHOES. REFLECTIVITY WOULD ALSO SUGGEST SLEET MIXED WITH SNOW AT TIMES TIL SOUNDINGS CRASH TO WET BULB. POTENT ISENT LIFT DROVE BAND OF LGT RAIN INTO IA OVERNIGHT AND IS IN THE PROCESS OF MERGING WITH DEF ZN. 06Z RUC RAPIDLY BREAKS OUT PCPN 12-15Z AND CIG TRENDS UPSTREAM SUPPORT THAT THINKING. HAVE TRIMMED SNOW AMOUNTS BACK SOMEWHAT SINCE LITTLE WILL HAVE OCCURRED BY 12Z...BUT STILL HAVE 5-6 INCHES IN WARNING AREA LOOSELY BASED ON HPC QPF AND 12:1 RATIOS SUGGESTED BY COBB OUTPUT. 1-4 IN ADVISORY AREA. NO CHANGES TO HEADLINES BEYOND NOT STARTING TIL 6AM. THIS MAY BE A TAD TOO AGGRESSIVE WITH DURATION SOMEWHAT IN QUESTION...BUT CERTAINLY EXPECT 3-6 HOURS OF CONVECTIVE OR NEAR CONVECTIVE SNOWS AND RATES >1"/HR AT TIMES WITH RATIOS HIGHER FOR MOMENTS. DENDRITIC FORCING IN 300K SFC OR AROUND 600MB VERY IMPRESSIVE THROUGH 18Z WITH KINEMATIC AND THERMODYNAMIC FORCING MECHANISMS ALL COMING TOGETHER. STILL EXPECT BLOWING AND DRIFTING TO BE A PROBLEM AS WELL WITH STRONG ISALLOBARIC PUSH AND INCREASED MSLP GRADIENT BY AFTERNOON. MADE A FEW ADJUSTMENTS TO PCPN TYPE TOO. MODELS UNDERESTIMATED DEPTH OF SFC LOW AT 06Z AND AMOUNT OF WARM AIR AHEAD OF SYS. 05Z MDCRS SOUNDING AT KDSM ABOUT 2-3C WARMER THAN MODELS WITH WARM LYR UP TO 8C. THUS HAVE PUSHED RAIN/SNOW LINE A BIT FARTHER N...ESPECIALLY CENTRAL AND SOUTH...AND ALSO ADDED SLEET AS MENTIONED EARLIER. SYS SHOULD EXIT QUICKLY EARLY THIS EVE WITH LITTLE OR NO ADDITIONAL AMOUNTS IN LGT SNOW OR FLURRIES AFTER 00Z. FEEL GUIDANCE ON THE COOL SIDE TODAY...ESPECIALLY SRN PORTIONS CLOSER TO WARM SECTION...SO HAVE GONE ABOVE WARMEST GUIDANCE THERE. LITTLE CHANGE FOR TONIGHT. BY TOMORROW WENT CLOSE TO GUIDANCE BLEND NEAR SNOW COVER...BUT BOOSTED TO AT OR ABOVE WARMEST GUIDANCE S AS HAS BEEN THE CASE RECENTLY. SIMILAR THINKING FOR HIGHS SAT. .LONG TERM...SUN THROUGH WED NO SIGNIFICANT CHANGES IN THIS PERIOD...BUT DID BOOST POPS FARTHER THROUGH CHANCE CATEGORY MONDAY AND MONDAY NIGHT. ECMWF/GFS/UKMET SIMILAR WITH TRACK BUT FAVORED SLOWER EURO SOLUTIONS WITH H5 LOW CLOSED. THIS EVENT WINDOW WILL NEED TO BE EXAMINED MORE CLOSELY BY DAY SHIFT AND WILL ADD MENTION OF POSSIBILITY OF ACCUMULATING SNOW TO HWO. && .DMX WATCHES/WARNINGS/ADVISORIES... WINTER WX ADVISORY 6AM-6PM FOR GRUNDY-HAMILTON-HARDIN-POCAHONTAS-TAMA-WEBSTER. WINTER STORM WARNING 6AM-6PM FOR BLACK HAWK-BREMER-BUTLER-CERRO GORDO-EMMET-FRANKLIN-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-WINNEBAGO-WORTH-WRIGHT. && $$ SMALL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 346 AM CST THU MAR 16 2006 .DISCUSSION...TODAY THROUGH SATURDAY NIGHT BAND OF SNOW ASSOCIATED WITH MID LEVEL FRONTOGENESIS...AND NEAR NORTH EDGE OF MAX 850 MB THETA E ADVECTION HAS SHIFTED EAST SOMEWHAT INTO WEST CENTRAL WISCONSIN...AND ALSO SAGGED SLIGHTLY FARTHER SOUTH SINCE 06Z. LAPS STORM TOTAL SNOW SHOWING 3 TO 4 INCHES FROM THIS BAND...AND SEEMS TO BE CLOSE BASED ON REPORTS WE WERE RECEIVING AT AROUND MIDNIGHT. 06Z NAM AND RUC SHOWING THAT THIS FORCING REMAINS CLOSE TO THE SAME AREA FOR A COUPLE HOURS THIS MORNING AND THEN SHIFTS SOUTH DURING MID MORNING AND WEAKENS SLIGHTLY. HOWEVER..VORT MAY OVER NE NEB AREA WILL ENHANCE FORCING OVER SOUTH CENTRAL MN THIS MORNING...AND THIS LINGERS INTO AFTERNOON. WINDS SHOULD KICK UP MORE OVER SOUTHERN MN AS SURFACE LOW PASSES ACROSS SOUTHERN IOWA. WILL KEEP THE WARNING GOING WITH SAME GENERAL TIME FRAME TODAY..BUT EXTEND INTO AFTERNOON ACROSS FAR SOUTHERN MN. SNOW AMOUNTS SHOULD WORK OUT OK. AREAS OVER SOUTH CENTRAL MN HAVE NOT RECEIVED MUCH SNOW YET BUT THIS SHOULD PICK UP THIS MORNING. WILL NEED TO WATCH AREAS AROUND MSP AREA INTO WEST CENTRAL WI THOUGH IF ANOTHER BAND DEVELOPS. A BIT OF A SUSPECT AREA OVER WEST CENTRAL MN IN TERMS OF REACHING WARNING SNOW AMOUNTS...BUT FAIRLY CLOSE TO SECONDARY FORCING MECHANISMS MENTIONED ABOVE. HIGH PRESSURE BUILDING IN LATER TONIGHT SHOULD BLOW CLEAR OUT THE CLOUDS IN MANY AREAS. DRIER AIR FRIDAY INTO SATURDAY...COMBINED WITH NEW SNOW SHOULD HELP TO DROP MID TEMPS BELOW GUIDANCE. LONGER TERM...SUNDAY THROUGH THURSDAY LATEST GFS...00Z VERSION...CONTINUES PREVIOUS TREND OF A VERY BLOCKY PATTERN WITH THE STORM TRACK ACROSS THE SOUTHERN UNITED STATES...AND A PERSISTENT SFC HIGH PRESSURE RIDGE POKING DOWN INTO MN FROM CANADA. TRIMMED BACK THE PRECIPITATION CHANCES TO JUST WESTERN AND SOUTHERN AREAS MONDAY NIGHT AND TUESDAY...AND THAT MAY STILL BE TOO MUCH. 00Z MEX TEMPERATURES DEPICT BELOW NORMAL VALUES...AND GIVEN THE SURFACE AND UPPER PATTERN FROM THE LAST 3 RUNS OF THE GFS THIS LOOKS QUITE REASONABLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WARNING UNTIL NOON CST TODAY FOR ANOKA-BROWN-CARVER- CHIPPEWA-DAKOTA-HENNEPIN-KANDIYOHI-LAC QUI PARLE-LE SUEUR- MCLEOD-MEEKER-NICOLLET-RAMSEY-REDWOOD-RENVILLE-SCOTT-SIBLEY- SWIFT-WASHINGTON-WRIGHT-YELLOW MEDICINE COUNTY(IES). WINTER STORM WARNING UNTIL 6 PM CST THIS AFTERNOON FOR BLUE EARTH-FARIBAULT-FREEBORN-GOODHUE-MARTIN-RICE-STEELE-WASECA- WATONWAN COUNTY(IES). WI...WINTER STORM WARNING UNTIL 6 PM CST THIS AFTERNOON FOR CHIPPEWA- DUNN-EAU CLAIRE-PEPIN-PIERCE-ST. CROIX COUNTY(IES). && $$ JPR/MTF/RJN mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 407 AM CST THU MAR 16 2006 .DISCUSSION...SHORT TERM(TODAY THROUGH FRIDAY)...WATER VAPOR IMAGERY/RUC ANALYSIS SHOWS A FAIRLY POTENT SHORTWAVE OVER THE CENTRAL PLAINS THAT IS SUPPORTING A SURFACE LOW OVER NORTHEAST KANSAS THAT WILL TRACK EAST AND DRAG A COLD FRONT ACROSS OUR AREA TONIGHT. AHEAD OF THE APPROACHING COLD FRONT MOISTURE WILL INCREASE TODAY. LOCAL WIND PROFILERS ACROSS EAST TEXAS...LOUISIANA AND MISSISSIPPI SHOW THE 80H FLOW HAS BECOME SOUTHWESTERLY AND INCREASED TO 30-40KTS. THIS HAS LED TO AN INCREASED MID LEVEL DECK ACROSS OUR CWA THIS MORNING INCLUDING A FEW RETURNS ON LOCAL RADARS IN THE SW THAT ARE LIKELY NOT REACHING THE GROUNDS. OUR SFC DEW POINTS HAVE BEEN SLOW TO INCREASE WITH SITES NORTH OF HIGHWAY 84 STILL IN THE MID 30S. HAVE BACKED OFF ANY POPS IN THE CWA UNTIL AFTER 6 AM. LIGHT RAIN WILL GRADUALLY DEVELOP FROM THE SOUTHWEST THIS MORNING. INSTABILITY LOOKS TO REMAIN LIMITED THIS MORNING WITH THE EXCEPTION OF SOME FAVORABLE MID LEVEL LAPSE RATES AND A FEW ISOLATED THUNDERSTORMS CAN'T BE RULED OUT IN OUR SOUTHWEST COUNTIES AND PARISHES BEFORE NOON. THE COLD FRONT IS EXPECTED TO BE IN OUR SOUTHEAST ARKANSAS COUNTIES BY 6 PM THIS EVENING. AN NARROW POOL OF DEEP MOISTURE IS EXPECTED JUST AHEAD OF THE COLD FRONT LATE THIS AFTERNOON...AS THE RIGHT ENTRANCE REGION OF A 110KT JET STREAK MOVES OVER OUR SOUTHERN COUNTIES AND PARISHES. THIS IS EXPECTED TO LEAD TO A BRIEF TIME PERIOD LATE THIS AFTERNOON INTO EARLY EVENING WHERE A FEW THUNDERSTORMS MAY BECOME STRONG ACROSS OUR SOUTHERN LOUISIANA PARISHES AND SOUTHWEST MISSISSIPPI COUNTIES. OTHERWISE...LIGHT RAIN WITH A FEW ISOLATED THUNDERSTORMS IS EXPECTED BEFORE THE COLD FRONT MOVES THROUGH. THE COLD FRONT SHOULD BE NEAR JACKSON AT MIDNIGHT AND SOUTH OF HATTIESBURG BY THE START OF THE DAY FRIDAY. THE BULK OF THE RAIN WILL FALL SOUTH OF I-20 TODAY AND HAVE GONE ABOVE GUIDANCE THERE. FRIDAY WILL BE DRY AS SHORTWAVE RIDGING BEGINS EDGING INTO OUR REGION WHILE SURFACE HIGH PRESSURE CENTERED OVER CANADA NOSES SOUTH ACROSS OUR REGION. TEMPERATURES WILL BE BELOW NORMAL FRIDAY BUT RATHER MILD WITH HIGHS IN THE 60S. /22/ COLD...WET WEEKEND IN STORE FOR THE CWA. ISENTROPIC LIFT TAKES OVER SAT MORNING AND LAST THROUGH MON. WE WILL NEED TO MOISTEN UP THE COLUMN SOME FIRST AND THAT WILL TAKE ALL DAY FRIDAY AND INTO SATURDAY SO NOT EXPECTING TO SEE MUCH IN THE WAY OF PRECIP UNTIL LATE SAT MORNING OR EVEN AFTER MIDDAY BUT ONCE IT STARTS IT COULD BE A LONG TIME UNTIL THE RAIN COMPLETELY ENDS. IT WILL START OF AS SHRA AND LAST LIKE THAT THROUGH MOST OF THE DAY SUN BUT BY SUN AFTERNOON THERE MAY BE SOME SCT EMBEDDED TSRA AS SOME ELEVATED INSTABILITY MOVES INTO THE AREA. THIS MAY ALL CHANGE MON AS TSRA WILL BE MORE WIDESPREAD AND THE RAIN MAY GETS HEAVIER AND STARTS TO ACCUMULATE POSSIBLY LEADING TO FLOODING ISSUES ESPECIALLY MONDAY AS SEVERE STORMS BECOME POSSIBLE. GFS CONTINUES TO COME MORE INLINE WITH THE EURO ON THE TIMING OF MONDAY'S SYSTEM. STILL A VERY IMPRESSIVE RAIN MAKER WITH THE POSSIBILITY OF SEVERE WEATHER. H5 LOW DIGS INTO THE STHRN PLAINS AND GOES NEGATIVELY TILTED MON WHILE THE SFC LOW TRACKS FROM TX THROUGH AR AND INTO TN/KY. GFS STILL SHOWING LL FLOW OF 45-55KTS BRINING IN H85 THETA E AIR OF 330K+ (UP TO 334K). VERY GOOD ELEVATED INSTABILITY WITH SHOWALTERS OF -3. WIND FIELD IS IMPRESSIVE AND FAVORABLE THROUGH THE ATMOSPHERE. THERE APPEARS TO BE A WEAK COUPLED JET FEATURE OVER ESTRN MS BY 00Z TUE WITH A 120KT+ JET CORE MOVING THROUGH NRTHN LA AND STHRN AR. 60 KT H5 FLOW INCREASING TO AS HIGH AS 100 KTS PUSHING INTO THE CWA LATE MON. 65 TO 80 KTS H7 BRINGING IN ANOTHER STRONG DRY PUNCH AND MENTIONED EARLIER A LL JET OF 45 TO 55 KTS SETTING UP OVER THE MS/AL BORDER. TRACK AND PLACEMENT OF H5 LOW AND SFC LOW HAVE BEEN FAVORABLE FOR SEVERE WEATHER IN THE PAST. DEEP MOISTURE IS IMPRESSIVE WITH PWS POSSIBLY APPROACHING 2" MON. THE PROBLEM MAY BE OVERALL INSTABILITY AND DEWPOINTS ONCE AGAIN. GFS DOES SHOW LOWER 60 DEWPOINTS AND MAYBE MID 60S DEWPOINTS PUSHING INTO THE AREA. ALSO WITH RAIN GOING ON THROUGH THE WEEKEND AND INTO MON THERE WILL BE CONSIDERABLE CLOUD COVER OVER THE AREA AND THIS WILL KEEP THE AREA FROM HEATING UP DURING THE DAY HINDERING DESTABILIZATION. I WILL CONTINUE TO MENTION IN THE HWO THE THREAT OF BOTH HEAVY RAIN AND STRONG TO SEVERE STORMS BUT THE MAIN THREAT LOOKS TO BE VERY HEAVY RAIN AS OF RIGHT NOW. AFTER THIS SYSTEM MOVES THROUGH LATE MON EARLY TUE...EXPECT DRIER AND MUCH COOLER CONDITIONS OVER THE AREA. SPEAKING OF TEMPS I AM VERY CONFUSED WITH THE GUIDANCE TEMPS. RIGHT NOW THE MEX GUIDANCE SEEMS TO WARM COMPARED TO THE LL TEMPS...ESPECIALLY TUE. LOOKING AT CLIMATE STATISTICS FOR OUR AREA...IN MID MARCH WITH H85 AND H925 TEMPS OF LESS THAN 2C(GFS SHOWING H85 TEMPS DROPPING THROUGHOUT THE DAY TO AS LOW AS -3C WHILE H925 TEMPS DROP TO -3/-4C) WE HAVE A VERY HARD TIME GETTING ABV THE UPPER 50S. THE BIGGER PROBLEM IS THAT THESE LL TEMPS ARE A GOOD BIT LOWER THAN 2C AND THIS MAKES IT HARD FOR US TO GET TO THE LOWER AND MID 50S. I HAVE A HARD TIME GOING 10 DEGREES OR MORE AWAY FROM GUIDANCE BUT I AM GOING TO GO A GOOD BIT COOLER ATLEAST 5 DEGREES EVERYWHERE AND A FEW MORE DEGREES IN SOME LOCATIONS. WILL WAIT TO SEE WHAT THE ENSEMBLE GUIDANCE HAS BEFORE MAKING FINAL ADJUSTMENTS. EITHER WAY IT LOOKS LIKE HIGHS WILL ACTUALLY OCCUR FAIRLY EARLY IN THE DAY WITH TEMPS COOLING THROUGH THE AFTERNOON. TEMPS REMAIN COOL THROUGH THE WEEK BUT DO START TO MODERATE A LITTLE BY WEEKS END. ALSO WE REMAIN DRY UNTIL POSSIBLY FRI BUT THE 3 DAYS OF DRY WEATHER MAY BE WELCOME FOR THE AREA TO DRY FROM THIS WEEKENDS DELUGE. /CAB/ && .AVIATION...VFR CONDITIONS WITH CEILINGS REMAINING ABOVE 3000FT ARE EXPECTED TO CONTINUE THROUGH 18Z OVER MOST OF THE AREA. AS RAIN AND A FEW THUNDERSTORMS INCREASE THIS AFTERNOON FROM THE SOUTHWEST BRIEF PERIODS OF MVFR CONDITIONS ARE EXPECTED. THUNDERSTORMS COVERAGE WILL BE GREATEST SOUTH INTERSTATE 20 TODAY. WIDESPREAD MVFR CONDITIONS WITH CEILINGS BETWEEN 2-3KFT ARE EXPECTED AFTER 00Z FRI AS THE COLD FRONT MOVES ACROSS THE AREA. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 65 48 65 40 / 52 30 3 3 MERIDIAN 66 48 65 38 / 54 35 3 1 VICKSBURG 65 48 65 43 / 48 22 3 7 HATTIESBURG 68 54 70 43 / 64 32 4 4 NATCHEZ 65 50 65 44 / 65 26 3 7 GREENVILLE 65 43 63 39 / 23 11 3 17 GREENWOOD 64 43 62 39 / 25 15 3 11 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 22/24 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1100 AM EST THU MAR 16 2006 .UPDATE... AT 15Z THE SURFACE LOW WAS OVER NE MO...AND THE BEST PRESSURE FALLS WERE LOCATED ALMOST DUE E OVER THE IL/IN BORDER. THIS IS ENCOURAGING FOR THE SNOW ADVY...AS THIS SUGGESTS A MORE EWD TRACK OF THE LOW COMPARED TO LATEST GFS/NAM/NAMX PROGS OF A SEWD TRACK. RADAR SUGGESTS SOME FGEN BANDING NEAR THE SRN WI STATE LINE...WITH SEVERAL METAR SITES REPORTING 1/2SM OR LESS. RUC H6 FGEN PROGS AGREE WELL WITH CURRENT RADAR DISPLAY...AND THIS AREA SHIFTS E TO FAR SRN LWR BY THIS AFTN. LOCAL SOUNDINGS QUITE DRY IN THE LOWER TROP THIS MORNING...BUT THIS COULD HELP WET BULB COOLING EFFECTS LATER THIS EVENING AND KEEP PCPN AS SN WHEN BETTER FGEN WORKS E INTO THE AREA. AFTER COORDINATION WITH IWX...HAVE LOWERED SN AMOUNTS SLIGHTLY...BUT WE ARE KEEPING THE ADVISORY GOING. TIMING LOOKS TO BE A LITTLE LATER...SO HAVE WORDED THIS IN THE UPDATED WSW. WILL UPDATE ZONES SHORTLY. MARINE - HAVE UPDATED THE WIND GRIDS TO MORE CLOSELY REFLECT SLIGHTLY STRONGER NAM WINDS. THIS PUSHES WAVES UP TO AROUND 4 FT BY 10Z FRI MORNING. AS THIS IS LATE IN THE PERIOD...WILL HOLD OFF ON A SCA FOR NOW. && .GRR WATCHES/WARNINGS/ADVISORIES...SNOW ADVISORY UNTIL 3 AM FRI FOR OTTAWA...ALLEGAN...BARRY...VAN BUREN...CALHOUN AND KALAMAZOO COUNTIES. && $$ TJT mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 300 PM MST THU MAR 16 2006 .SHORT TERM DISCUSSION...TWO ITEMS OF CONCERN TODAY. FIRST IS THE PRECIPITATION CHANCE IN THE HIGH COUNTRY. VERY LITTLE GOING ON UPSTREAM OF US AT THIS POINT IN TIME ALTHOUGH THE RUC QG ANALYSES HAVE BEEN SHOWING CONSISTENT...ALBEIT WEAK...ASCENT OVER THE GREAT BASIN FOR MOST OF THE DAY. UNFORTUNATELY THIS ASCENT IS LIFTING SOME PRETTY DRY AIR...AS HAS BEEN THE CASE MOST OF THIS WINTER...SO EXPECT ANY MOUNTAIN PRECIPITATION TO HOLD OFF UNTIL AFTER 12Z FRIDAY. ONCE ANYTHING THAT DOES GET GOING UP THERE STARTS IT SHOULD NOT AMOUNT TO VERY MUCH AS OROGRAPHIC ENHANCEMENT IS NOT TERRIBLY FAVORABLE WITH THE SOUTHWEST FLOW...LAPSE RATES ARE NOT TOO GOOD AND THE QG LIFT REMAINS RATHER MARGINAL THROUGH THE DAY. ALL OF THESE IDEAS ARE SUPPORTED BY THE LATEST LOCAL MM5 RUN SHOWING ONLY SCANT PRECIPITATION AMOUNTS IN THE MOUNTAINS. THE OTHER ITEM IS THE COLD AIR LURKING ABOUT TO OUR NORTHEAST AND HOW MUCH OF THAT WILL OOZE INTO THE CWA. MODELS SUGGEST THAT IT SHOULD MAKE IT INTO THE NORTHEAST PART OF THE CWA BUT ITS SHALLOWNESS WILL NOT BODE WELL FOR IT MAKING IT UP THE HILL INTO THE DENVER AREA. WITH THAT IN MIND HAVE LOWERED TEMPERATURES SOME NORTH AND EAST OF DENVER TOMORROW. .LONG TERM DISCUSSION...FOCUS CONTINUES TO BE ON EVOLUTION OF AN UPPER TROUGH OVER THE SOUTHWESTERN U.S. THROUGH THE WEEKEND. MODEL RUNS FROM 12Z CONTINUED THE PRIOR TREND OF AN ELONGATED...NEGATIVELY TILTED UPPER TROUGH STRETCHING FROM NEW MEXICO TO WASHINGTON BY SUNDAY EVENING. SURFACE PRESSURE PATTERNS CONTINUED WITH A SURFACE LOW OVER SERN CO/NERN NM AND A STRONG SURFACE HIGH OVER CANADA. THIS LOW LEVEL PATTERN WOULD ALLOW GULF MOISTURE TO ADVECT NORTHWARD OVER THE GREAT PLAINS AND INTO ERN CO. WITH THE DEPTH OF THE TROUGH AND THE AVAILABILITY OF MOISTURE THROUGH THE WEEKEND...IT IS BECOMING CLEAR THAT A PROLONGED PRECIPITATION EVENT WILL DEVELOP OVER THE MOUNTAINS AND SPREAD ONTO THE PLAINS AT SOME POINT. THE 18Z RUN OF THE NAM IS NOW SHOWING THE TROUGH TO HAVE LESS ELONGATION TO IT...WHICH WOULD ALLOW MORE CIRCULATION TO DEVELOP OVER EASTERN COLORADO ON SUNDAY AFTERNOON. IF THE MODELS CONTINUE THIS TREND THROUGH TOMORROW...HIGHLIGHTS FOR THE LATTER HALF OF THE WEEKEND MAY BECOME NECESSARY. FOR NOW...WILL JUST STICK WITH PROBABILITY OF PRECIPITATION VALUES IN THE CHANCE CATEGORY. BEFORE THE TROUGH ARRIVES...OR POSSIBLY CUTS OFF...SATURDAY SHOULD SEE INCREASING PRECIPITATION IN THE MOUNTAINS AS MOIST SOUTHWESTERLY FLOW ALOFT CONTINUES. ON THE PLAINS...TEMPERATURES WILL BE COOLER AS SHALLOW COLD AIR FROM THE NORTHERN PLAINS MOVES IN FROM THE NORTHEAST. LOW LEVEL TEMPERATURE FIELDS FROM THE NAM AND GFS DO NOT SHOW THE MAIN COLD AIR MOVING INTO THE REGION UNTIL SUNDAY...BUT MOS GUIDANCE VALUES SHOW THE INITIAL COOLING ARRIVING SATURDAY. IF THE COOLER AIR MOVES ONTO THE PLAINS SATURDAY AFTERNOON...THEN A CHANCE OF UPSLOPE PRECIPITATION WON'T BE TOO FAR BEHIND. SUNDAY AND SUNDAY NIGHT'S PRECIPITATION EVENT WILL BEGIN WINDING DOWN OVER OUR FORECAST AREA THROUGH MONDAY. WITH UPPER LEVEL RIDGING FORECAST TO DEVELOP OVER THE WESTERN U.S. ON MONDAY...DRIER WEATHER AND MODERATING TEMPERATURES ARE EXPECTED THROUGH THE FIRST HALF OF NEXT WEEK. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ET/KDRBY co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 320 PM EST THU MAR 16 2006 .SYNOPSIS... WATER VAPOR IMAGES SHOW A DIGGING TROUGH OFF THE W COAST...WHICH IS ALREADY STARTING TO INDUCE DOWNSTREAM RIDGING OVER THE INTERMOUNTAIN W. LOCALLY...A SHORTWAVE TROUGH OVER ERN IA IS HELPING TO INDUCE FGEN NEAR A WELL DEFINED SNOWBAND EXTENDING FROM ERN IA...THROUGH NRN IL...AND INTO NRN IN. IFR AND LIFR VSBYS IN SN WERE BEING REPORTED UNDER THIS BAND. .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)... MAIN CONCERN IS WHAT TO DO WITH THE CURRENT SNOW ADVISORY. ALTHOUGH THERE IS GOOD SN FALLING AT THIS TIME UNDER THE BAND...WARM SURFACE TEMPERATURES AND PHONE REPORTS INDICATE THAT NOTHING HAS THE CHANCE TO STICK. FURTHERMORE...RUC PROGS SHOW BEST FGEN WILL PUSH E AND WEAKEN BY 00Z AS THE H8 LOW OPENS UP. SO...CURRENT THINKING IS THAT WE WILL DROP THE ADVISORY. OTHERWISE...SHORT RANGE MODELS ARE IN GOOD AGREEMENT WITH THE CWFA BEING BETWEEN SYSTEMS...NAMELY A DEEP APPROACHING TROUGH OVER THE WRN USA AND A BROAD STACKED LOW CENTERED OVER THE NEW BRUNSWICK AREA. THIS WILL KEEP A SHARP RIDGE JUST UPSTREAM AND DEEP SUBSIDENT NWLY FLOW OVER THE CWFA FOR MOST OF THE PERIOD. TONIGHT - WILL DROP THE ADVISORY AND GO CLOSER TO 1-3 INCH TOTALS. FRIDAY - HAVE LOWERED POPS TO SILENT AS LOW SFC-H8 DELTA T AND LOW MEAN RH VALUES WITH BROAD SUBSIDENCE KEEP LAKE EFFECT NEGLIGIBLE. SATURDAY/SATURDAY NIGHT - NO SIGNIFICANT CHANGES WERE MADE. .LONG TERM (SUNDAY THROUGH THURSDAY)... FOR THE EXTENDED PERIOD BLOCKING CONTINUES AT 500MB ACROSS THE NORTH PACIFIC. THIS HAS ALLOWED LOWERING OF HEIGHTS FROM THE ALEUTIANS EAST THROUGH WESTERN CANADA. THROUGH THE EXTENDED PERIOD HEIGHTS WILL BEGIN TO RELAX ACROSS NORTHERN PACIFIC...WITH THE ATMOSPHERIC BLOCK RETROGRADING WEST TOWARDS THE DATELINE. MODELS HAVE BEEN IN AGREEMENT THROUGH THE WEEKEND WITH KEEPING AN EASTERN PACIFIC LOW WEST OF THE CONUS...AND SLIDE SOUTH. EXTREME EASTERN QUEBEC MID LEVEL LOW WILL CONTINUE TO WEAKEN AND MOVE EAST. THE COMBINATION OF THE TWO MID LEVEL FEATURES WILL ALLOW BROAD RIDGING EXTENDING FROM NORTHERN PORTIONS OF ALBERTA...SASKATCHEWAN...AND MANITOBA EXTENDING SOUTH THROUGH CENTRAL CONUS. LATE WEEKEND PROPAGATION OF JET ALONG WEST COAST POINTS DUE S...WHICH WILL HELP DIG 500MB LOW OFFSHORE OF CA. SW CONUS JET INCREASES WITH DEVELOPMENT OF SOUTHERN STREAM LOW QUICKLY MOVING THROUGH CENTRAL PLAINS EARLY NEXT WEEK. EXPECT THE BULK OF MOISTURE AND DYNAMICS TO REMAIN SOUTH OF LWR MI...HOWEVER A SECOND AREA OF LOW PRESSURE CENTERED ACROSS WESTERN QUEBEC MAY FUNNEL MOISTURE AND CLOUDS INTO LWR MI. WEAK RETURN FLOW MOISTURE SHOULD AID IN ENHANCED PRECIP ACROSS OHIO RIVER VALLEY. 850MB TEMPS COOL TO -10 TO -13 DEG C THROUGH MID WEEK. WITH LGT NW FLOW...SCT FLURRIES OR SNOW SHOWERS MAY DEVELOP. EXPECT TEMPS TO REMAIN A FEW DEGREES BELOW NORM. && .GRR WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY ALL NEARSHORE WATERS FROM 3 AM FRI THROUGH FRIDAY AFTERNOON. && $$ SHORT TERM: TJT LONG TERM: BEACHLER mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 300 PM EST THU MAR 16 2006 .DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ZONAL FLOW ACRS THE SCNTRL CONUS TO THE S OF A VERY BLOCKED FLOW ACRS CANADA. DEEP NRLY STNRY VORTEX REMAINS OVER SCNTRL CAN...WITH OMEGA BLOCK UPR RDG OVER CNTRL CAN. SPRAWLING 1045MB SFC ARCTIC HI PRES BLDG INTO NRN MANITOBA UNDER THIS RIDGE. 12Z INL/YPL/YQD SDNGS SHOW DRY LLVLS... AND SFC DWPTS BLO 0F ACRS SCNTRL CAN/MUCH OF NW ONTARIO. 12Z PWATS AOB 0.10 INCH AT YQD/YPL/INL. SO DESPITE LGT NNE FLOW OF COLD AIR OVER LK SUP ATTM (UPSTREAM SFC TEMPS IN THE TEENS/H85 TEMPS ARND -13C)...NOTHING MORE THAN SOME PTCHY SC OBSVD OVER LK SUP. THERE IS A PAIR OF WEAK SHRTWVS ACRS NW ONTARIO AND SRN SASKATCHEWAN ON THE SRN FLANK OF THE RDG...BUT AIRMASS IS SO DRY MAINLY JUST HI CLD OBSVD. OTRW...FA IS ON NRN FRINGE OF HI CLD ASSOCIATED WITH RATHER POTENT LO PRES MOVING E THRU THE MID MS RIVER VALLEY. DRY NLY FLOW OUT OF RDG TO THE N WL KEEP THIS LO...ITS PCPN...AND EVEN MOST OF THE CLD COVER SAFELY TO THE S. MAIN FCST CONCERNS THE NEXT FEW DAYS ARE TEMPS/SMALL LES CHCS. LATEST MODEL GUIDANCE IN GOOD AGREEMENT SHOWING SFC-H85 RDG AXIS REMAINING NRLY STNRY JUST W OF THE FA TO THE S OF HI CENTER NEAR NRN MANITOBA AND W OF BLOCKING VORTEX IN SE CAN THRU SAT. WEAK SHRTWVS OVER NW ONTARIO/SRN SASKATCHEWAN FCST TO SHEAR OUT/WEAKEN IN THE DRY N FLOW E OF THE RDG AXIS/W OF THE BLOCKING LO TO THE E. GFS/NAM FCST SDNGS SHOW INVRN HGT REMAINING ARND H9 THRU THE TIME WITH LTL CHG IN INVRN BASE TEMP (-12C TO -14C)...SO DON'T THINK THERE WL BE ANYTHING MORE THAN FLURRIES. SINCE SUN IS GETTING HIER IN THE SKY AND INSOLATION BEGINNING TO DRIVE LK BREEZE CIRCULATION...SUSPECT LK CLD MIGHT BECOME MORE WDSPRD DURING THE NGTS AND THRU THE MRNG BEFORE BRKG UP IN THE AFTN WITH AIR TENDING TO RISE OVER LAND/SINK OVER WATER. WL PROBABLY MAINTAIN GOING FCST OF A BIT MORE CLD COVER/SML CHC POP ON FRI NGT/SAT OVER THE E AS LATEST NAM/UKMET HINT AT SOMEWHAT HIER H85 MSTR/LOWER H85 TEMP SWINGING BY WITH PASSAGE OF SHEARED SHRTWV NOW OVER NW ONTARIO AND MORE NW LLVL FLOW...BUT WL NOT BE TOO PESSIMISTIC CONSIDERING DRYNESS OF UPSTREAM AIRMASS. AS FOR TEMPS...WL GO AOB MOS GUIDANCE AT THE COLDER INTERIOR LOCATIONS AT NGT BUT THEN HAVE TEMPS RECOVERING AOA GUIDANCE WITH AT LEAST A GOOD DEAL OF SUNSHINE/JUST A FEW CU DURING THE AFTNS. THE MEDIUM/EXTENDED RANGE PROMISES TO BE A QUIET ONE WITH NEGATIVE NAO PATTERN PERSISTING...BLOCKING UPR RDG ACRS GREENLAND/NE CANADA LOCKING VORTEX IN PLACE ACRS SE CANADA. AT THE SFC...A SPRAWLING DRY AREA OF HI PRES WL REMAIN OVER CAN AND FORCE ANY LO PRES SYSTEMS MIGRATING E OUT OF WRN TROF TO STAY WELL S OF THE FA WITH RELATIVELY DRY NNE FLOW. ONLY PSBL FLYS IN THE OINTMENT WOULD BE SHRTWVS ROTATING ARND WRN FLANK OF STNRY VORTEX IN SE CAN AND PSBL WEAK LES. AT THIS POINT...TIMING DIFFERENCES ON THESE SHRTWS ABOUND. WL MAINTAIN PCLYD-MOCLDY SKIES/LO CHC POPS FOR THE LK SUP BORDER COUNTIES ON WED AND KEEP SN CHCS LINGERING THERE INTO THU. LATEST GFS RUNS SUG A SHRTWV PASSAGE ON TUE AS WELL...BUT WL HOLD OFF ON NO PCPN FCST GIVEN DRY LOOK OF ECMWF/UKMET/NCEP MANUAL GUIDANCE. OTRW... EXPECT A RELATIVELY WIDE DIURNAL RANGE IN TEMPS SUN-TUE WITH MAINLY CLR SKIES. NIGHTTIME LOWS OVER THE INTERIOR SHOULD FALL BLO MOS GUIDANCE...BUT DAYTIME TEMPS WL RECOVER NICELY UNDER INCRSGLY STRG LATE MARCH SUNSHINE. COORDINATED WITH GRB/DLH. && .MQT...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1028 AM CST THU MAR 16 2006 .UPDATE... POTENT LITTLE VORT TREKKING ACROSS EASTERN IOWA ATTM. SNOW HAS TAPERED OFF FROM WEST CNTRL MN TO THE NORTHERN SUBURBS THIS MORNING. WILL LET WARNING EXPIRE AT NOON FOR WC MN TO THE TWIN CITIES AREA. SOME EVIDENCE OF MODEST BANDING IN PORTIONS OF SC MN INTO WISC AND DESPITE WEAKENING TREND IN MODELS...12Z NAM CROSS SECTIONS OF NEGATIVE EPV...OMEGA AND SPECIFIC HUMIDITY DO SUGGEST ENOUGH LIFT AND MOISTURE SUCH THAT ANOTHER 2-4 INCHES ARE POSSIBLE FROM AEL TO RGK AND EAU. IN FACT...BUFKIT SHOWS LIFT NOW IN THE SNOW GROWTH LAYER WITH ABOUT FOUR INCHES AFTER 12Z THIS MORNING. THUS WILL KEEP THE WARNING THROUGH THE AFTERNOON FOR SC MN TO EAU AREA. TDK. && .PREV DISCUSSION... /ISSUED 346 AM CST THU MAR 16 2006/ DISCUSSION...TODAY THROUGH SATURDAY NIGHT BAND OF SNOW ASSOCIATED WITH MID LEVEL FRONTOGENESIS...AND NEAR NORTH EDGE OF MAX 850 MB THETA E ADVECTION HAS SHIFTED EAST SOMEWHAT INTO WEST CENTRAL WISCONSIN...AND ALSO SAGGED SLIGHTLY FARTHER SOUTH SINCE 06Z. LAPS STORM TOTAL SNOW SHOWING 3 TO 4 INCHES FROM THIS BAND...AND SEEMS TO BE CLOSE BASED ON REPORTS WE WERE RECEIVING AT AROUND MIDNIGHT. 06Z NAM AND RUC SHOWING THAT THIS FORCING REMAINS CLOSE TO THE SAME AREA FOR A COUPLE HOURS THIS MORNING AND THEN SHIFTS SOUTH DURING MID MORNING AND WEAKENS SLIGHTLY. HOWEVER..VORT MAY OVER NE NEB AREA WILL ENHANCE FORCING OVER SOUTH CENTRAL MN THIS MORNING...AND THIS LINGERS INTO AFTERNOON. WINDS SHOULD KICK UP MORE OVER SOUTHERN MN AS SURFACE LOW PASSES ACROSS SOUTHERN IOWA. WILL KEEP THE WARNING GOING WITH SAME GENERAL TIME FRAME TODAY..BUT EXTEND INTO AFTERNOON ACROSS FAR SOUTHERN MN. SNOW AMOUNTS SHOULD WORK OUT OK. AREAS OVER SOUTH CENTRAL MN HAVE NOT RECEIVED MUCH SNOW YET BUT THIS SHOULD PICK UP THIS MORNING. WILL NEED TO WATCH AREAS AROUND MSP AREA INTO WEST CENTRAL WI THOUGH IF ANOTHER BAND DEVELOPS. A BIT OF A SUSPECT AREA OVER WEST CENTRAL MN IN TERMS OF REACHING WARNING SNOW AMOUNTS...BUT FAIRLY CLOSE TO SECONDARY FORCING MECHANISMS MENTIONED ABOVE. HIGH PRESSURE BUILDING IN LATER TONIGHT SHOULD BLOW CLEAR OUT THE CLOUDS IN MANY AREAS. DRIER AIR FRIDAY INTO SATURDAY...COMBINED WITH NEW SNOW SHOULD HELP TO DROP MID TEMPS BELOW GUIDANCE. LONGER TERM...SUNDAY THROUGH THURSDAY LATEST GFS...00Z VERSION...CONTINUES PREVIOUS TREND OF A VERY BLOCKY PATTERN WITH THE STORM TRACK ACROSS THE SOUTHERN UNITED STATES...AND A PERSISTENT SFC HIGH PRESSURE RIDGE POKING DOWN INTO MN FROM CANADA. TRIMMED BACK THE PRECIPITATION CHANCES TO JUST WESTERN AND SOUTHERN AREAS MONDAY NIGHT AND TUESDAY...AND THAT MAY STILL BE TOO MUCH. 00Z MEX TEMPERATURES DEPICT BELOW NORMAL VALUES...AND GIVEN THE SURFACE AND UPPER PATTERN FROM THE LAST 3 RUNS OF THE GFS THIS LOOKS QUITE REASONABLE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WARNING UNTIL NOON CST TODAY FOR ANOKA-BROWN-CARVER- CHIPPEWA-DAKOTA-HENNEPIN-KANDIYOHI-LAC QUI PARLE-LE SUEUR- MCLEOD-MEEKER-NICOLLET-RAMSEY-REDWOOD-RENVILLE-SCOTT-SIBLEY- SWIFT-WASHINGTON-WRIGHT-YELLOW MEDICINE COUNTIES. WINTER STORM WARNING UNTIL 6 PM CST THIS AFTERNOON FOR BLUE EARTH-FARIBAULT-FREEBORN-GOODHUE-MARTIN-RICE-STEELE-WASECA- WATONWAN COUNTIES. WI...WINTER STORM WARNING UNTIL 6 PM CST THIS AFTERNOON FOR CHIPPEWA- DUNN-EAU CLAIRE-PEPIN-PIERCE-ST. CROIX COUNTIES. && $$ JPR/MTF/RJN mn AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE JACKSON MS 1040 AM CST THU MAR 16 2006 .DISCUSSION... MOIST LOW LEVEL AXIS EXTENDING FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION IS STARTING TO BE AFFECTED BY THE RIGHT ENTRANCE REGION OF A UPPER JET STREAK PIVOTING INTO THE SOUTHEAST CONUS. THIS BIT OF ENHANCED ATMOSPHERIC LIFT SHOULD BE ENOUGH TO GET AT LEAST SOME ISOLATED ELEVATED THUNDERSTORMS GOING OVER ALL BUT THE FAR NORTHWEST SECTIONS OF THE ARKLAMISS WITH AT LEAST SPOTTY SHOWERS AFFECTING MOST SPOTS BEFORE THE AFTERNOON IS OUT. HEAVY RAIN IS NOT ANTICIPATED AND THE RISK OF INTENSE THUNDERSTORMS APPEARS PRETTY LOW...MAINLY DUE TO THE ELEVATED NATURE OF CONVECTION AND VERTICAL TOTALS HOLDING LESS THAN 26. STILL COULD BE SOME SMALL HAIL FALLING FROM THE STRONGEST CORES...ESPECIALLY SOUTH OF I-20 IN NORTHEAST LA AND SOUTHWEST MS (WHERE BRIEF GUSTY WINDS WITH ANY STORMS WOULD ALSO NOT BE INCONCEIVABLE). THE FORECAST WAS UPDATED TO ADJUST TEMPERATURES A LITTLE (MAINLY A TOUCH DOWNWARD) WITH HIGHS EXPECTED TO HOLD IN THE 60S IN THE REGION WITH CLOUDS AND INTERMITTENT PRECIP. POPS WERE ALSO BROUGHT UP TO CATEGORICAL (80) IN PORTIONS OF CENTRAL MS AS RADAR TRENDS AND THE LATEST MODEL DATA SUGGEST VERY GOOD CHANCE OF AT LEAST LIGHT PRECIP AMOUNTS BY 00Z IN THESE AREAS. /BB/ && .PREVIOUS DISCUSSION... SHORT TERM(TODAY THROUGH FRIDAY)...WATER VAPOR IMAGERY/RUC ANALYSIS SHOWS A FAIRLY POTENT SHORTWAVE OVER THE CENTRAL PLAINS THAT IS SUPPORTING A SURFACE LOW OVER NORTHEAST KANSAS THAT WILL TRACK EAST AND DRAG A COLD FRONT ACROSS OUR AREA TONIGHT. AHEAD OF THE APPROACHING COLD FRONT MOISTURE WILL INCREASE TODAY. LOCAL WIND PROFILERS ACROSS EAST TEXAS...LOUISIANA AND MISSISSIPPI SHOW THE 80H FLOW HAS BECOME SOUTHWESTERLY AND INCREASED TO 30-40KTS. THIS HAS LED TO AN INCREASED MID LEVEL DECK ACROSS OUR CWA THIS MORNING INCLUDING A FEW RETURNS ON LOCAL RADARS IN THE SW THAT ARE LIKELY NOT REACHING THE GROUNDS. OUR SFC DEW POINTS HAVE BEEN SLOW TO INCREASE WITH SITES NORTH OF HIGHWAY 84 STILL IN THE MID 30S. HAVE BACKED OFF ANY POPS IN THE CWA UNTIL AFTER 6 AM. LIGHT RAIN WILL GRADUALLY DEVELOP FROM THE SOUTHWEST THIS MORNING. INSTABILITY LOOKS TO REMAIN LIMITED THIS MORNING WITH THE EXCEPTION OF SOME FAVORABLE MID LEVEL LAPSE RATES AND A FEW ISOLATED THUNDERSTORMS CAN'T BE RULED OUT IN OUR SOUTHWEST COUNTIES AND PARISHES BEFORE NOON. THE COLD FRONT IS EXPECTED TO BE IN OUR SOUTHEAST ARKANSAS COUNTIES BY 6 PM THIS EVENING. AN NARROW POOL OF DEEP MOISTURE IS EXPECTED JUST AHEAD OF THE COLD FRONT LATE THIS AFTERNOON...AS THE RIGHT ENTRANCE REGION OF A 110KT JET STREAK MOVES OVER OUR SOUTHERN COUNTIES AND PARISHES. THIS IS EXPECTED TO LEAD TO A BRIEF TIME PERIOD LATE THIS AFTERNOON INTO EARLY EVENING WHERE A FEW THUNDERSTORMS MAY BECOME STRONG ACROSS OUR SOUTHERN LOUISIANA PARISHES AND SOUTHWEST MISSISSIPPI COUNTIES. OTHERWISE...LIGHT RAIN WITH A FEW ISOLATED THUNDERSTORMS IS EXPECTED BEFORE THE COLD FRONT MOVES THROUGH. THE COLD FRONT SHOULD BE NEAR JACKSON AT MIDNIGHT AND SOUTH OF HATTIESBURG BY THE START OF THE DAY FRIDAY. THE BULK OF THE RAIN WILL FALL SOUTH OF I-20 TODAY AND HAVE GONE ABOVE GUIDANCE THERE. FRIDAY WILL BE DRY AS SHORTWAVE RIDGING BEGINS EDGING INTO OUR REGION WHILE SURFACE HIGH PRESSURE CENTERED OVER CANADA NOSES SOUTH ACROSS OUR REGION. TEMPERATURES WILL BE BELOW NORMAL FRIDAY BUT RATHER MILD WITH HIGHS IN THE 60S. /22/ COLD...WET WEEKEND IN STORE FOR THE CWA. ISENTROPIC LIFT TAKES OVER SAT MORNING AND LAST THROUGH MON. WE WILL NEED TO MOISTEN UP THE COLUMN SOME FIRST AND THAT WILL TAKE ALL DAY FRIDAY AND INTO SATURDAY SO NOT EXPECTING TO SEE MUCH IN THE WAY OF PRECIP UNTIL LATE SAT MORNING OR EVEN AFTER MIDDAY BUT ONCE IT STARTS IT COULD BE A LONG TIME UNTIL THE RAIN COMPLETELY ENDS. IT WILL START OF AS SHRA AND LAST LIKE THAT THROUGH MOST OF THE DAY SUN BUT BY SUN AFTERNOON THERE MAY BE SOME SCT EMBEDDED TSRA AS SOME ELEVATED INSTABILITY MOVES INTO THE AREA. THIS MAY ALL CHANGE MON AS TSRA WILL BE MORE WIDESPREAD AND THE RAIN MAY GETS HEAVIER AND STARTS TO ACCUMULATE POSSIBLY LEADING TO FLOODING ISSUES ESPECIALLY MONDAY AS SEVERE STORMS BECOME POSSIBLE. GFS CONTINUES TO COME MORE INLINE WITH THE EURO ON THE TIMING OF MONDAY'S SYSTEM. STILL A VERY IMPRESSIVE RAIN MAKER WITH THE POSSIBILITY OF SEVERE WEATHER. H5 LOW DIGS INTO THE STHRN PLAINS AND GOES NEGATIVELY TILTED MON WHILE THE SFC LOW TRACKS FROM TX THROUGH AR AND INTO TN/KY. GFS STILL SHOWING LL FLOW OF 45-55KTS BRINING IN H85 THETA E AIR OF 330K+ (UP TO 334K). VERY GOOD ELEVATED INSTABILITY WITH SHOWALTERS OF -3. WIND FIELD IS IMPRESSIVE AND FAVORABLE THROUGH THE ATMOSPHERE. THERE APPEARS TO BE A WEAK COUPLED JET FEATURE OVER ESTRN MS BY 00Z TUE WITH A 120KT+ JET CORE MOVING THROUGH NRTHN LA AND STHRN AR. 60 KT H5 FLOW INCREASING TO AS HIGH AS 100 KTS PUSHING INTO THE CWA LATE MON. 65 TO 80 KTS H7 BRINGING IN ANOTHER STRONG DRY PUNCH AND MENTIONED EARLIER A LL JET OF 45 TO 55 KTS SETTING UP OVER THE MS/AL BORDER. TRACK AND PLACEMENT OF H5 LOW AND SFC LOW HAVE BEEN FAVORABLE FOR SEVERE WEATHER IN THE PAST. DEEP MOISTURE IS IMPRESSIVE WITH PWS POSSIBLY APPROACHING 2" MON. THE PROBLEM MAY BE OVERALL INSTABILITY AND DEWPOINTS ONCE AGAIN. GFS DOES SHOW LOWER 60 DEWPOINTS AND MAYBE MID 60S DEWPOINTS PUSHING INTO THE AREA. ALSO WITH RAIN GOING ON THROUGH THE WEEKEND AND INTO MON THERE WILL BE CONSIDERABLE CLOUD COVER OVER THE AREA AND THIS WILL KEEP THE AREA FROM HEATING UP DURING THE DAY HINDERING DESTABILIZATION. I WILL CONTINUE TO MENTION IN THE HWO THE THREAT OF BOTH HEAVY RAIN AND STRONG TO SEVERE STORMS BUT THE MAIN THREAT LOOKS TO BE VERY HEAVY RAIN AS OF RIGHT NOW. AFTER THIS SYSTEM MOVES THROUGH LATE MON EARLY TUE...EXPECT DRIER AND MUCH COOLER CONDITIONS OVER THE AREA. SPEAKING OF TEMPS I AM VERY CONFUSED WITH THE GUIDANCE TEMPS. RIGHT NOW THE MEX GUIDANCE SEEMS TO WARM COMPARED TO THE LL TEMPS...ESPECIALLY TUE. LOOKING AT CLIMATE STATISTICS FOR OUR AREA...IN MID MARCH WITH H85 AND H925 TEMPS OF LESS THAN 2C(GFS SHOWING H85 TEMPS DROPPING THROUGHOUT THE DAY TO AS LOW AS -3C WHILE H925 TEMPS DROP TO -3/-4C) WE HAVE A VERY HARD TIME GETTING ABV THE UPPER 50S. THE BIGGER PROBLEM IS THAT THESE LL TEMPS ARE A GOOD BIT LOWER THAN 2C AND THIS MAKES IT HARD FOR US TO GET TO THE LOWER AND MID 50S. I HAVE A HARD TIME GOING 10 DEGREES OR MORE AWAY FROM GUIDANCE BUT I AM GOING TO GO A GOOD BIT COOLER ATLEAST 5 DEGREES EVERYWHERE AND A FEW MORE DEGREES IN SOME LOCATIONS. WILL WAIT TO SEE WHAT THE ENSEMBLE GUIDANCE HAS BEFORE MAKING FINAL ADJUSTMENTS. EITHER WAY IT LOOKS LIKE HIGHS WILL ACTUALLY OCCUR FAIRLY EARLY IN THE DAY WITH TEMPS COOLING THROUGH THE AFTERNOON. TEMPS REMAIN COOL THROUGH THE WEEK BUT DO START TO MODERATE A LITTLE BY WEEKS END. ALSO WE REMAIN DRY UNTIL POSSIBLY FRI BUT THE 3 DAYS OF DRY WEATHER MAY BE WELCOME FOR THE AREA TO DRY FROM THIS WEEKENDS DELUGE. /CAB/ && .AVIATION...VFR CONDITIONS WITH CEILINGS REMAINING ABOVE 3000FT ARE EXPECTED TO CONTINUE THROUGH 18Z OVER MOST OF THE AREA. AS RAIN AND A FEW THUNDERSTORMS INCREASE THIS AFTERNOON FROM THE SOUTHWEST BRIEF PERIODS OF MVFR CONDITIONS ARE EXPECTED. THUNDERSTORMS COVERAGE WILL BE GREATEST SOUTH INTERSTATE 20 TODAY. WIDESPREAD MVFR CONDITIONS WITH CEILINGS BETWEEN 2-3KFT ARE EXPECTED AFTER 00Z FRI AS THE COLD FRONT MOVES ACROSS THE AREA. /22/ && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 50 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 245 PM EST THU MAR 16 2006 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)... DECENT RETURNS SHOWING UP ON RADAR ACROSS NORTHERN OHIO BUT WITH DRY AIRMASS IN PLACE...IT APPEARS THAT THIS PCPN IS NOT REACHING THE GROUND (NOT SURE IF THE .12 REPORTED ON THE AOH OB THIS PAST HOUR WAS REAL). 12Z MODELS HAVE TRENDED SLIGHTLY FARTHER SOUTH WITH THE TRACK OF THE LOW OVERNIGHT TONIGHT...SPREADING PCPN DOWN ACROSS AREA THROUGH THIS EVENING. HOWEVER...AM CONCERNED ABOUT LARGE DRY SLOT ACROSS SOUTHERN ILLINOIS AND LATEST RUC SEEMS TO BE PICKING UP ON THIS...KEEPING MUCH OF SOUTHWEST FA MAINLY DRY TONIGHT. ISENTROPIC LIFT IS FORECAST TO INCREASE ON THE 290K-295 K SURFACES BETWEEN NOW AND 03Z AS SURFACE LOW MOVES FROM CENTRAL ILLINOIS INTO SOUTHERN INDIANA. AS A RESULT...EXPECT TO SEE PCPN BEGIN TO FILL IN A LITTLE FARTHER SOUTH THAN WHERE THINGS ARE CURRENTLY SHOWING UP ON RADAR. WITH THIS IN MIND...WILL STILL ALLOW FOR PCPN TO DEVELOP DOWN INTO FA THROUGH THIS EVENING...BUT WE COULD END UP WITH A FAIRLY SHARP SOUTHERN EDGE. WILL THEREFORE...ONLY GO WITH CHANCE POPS ACROSS THE SOUTHWEST. MODELS FAIRLY CONSISTENT SHOWING BOUNDARY LAYER COOLING OFF FROM NORTH TO SOUTH ACROSS THE AREA OVERNIGHT. BASED ON BLEND OF FORECAST SOUNDINGS FROM THE GFS AND NAM...EXPECT PCPN TO MIX WITH AND THEN CHANGE OVER TO SNOW ACROSS THE FAR NORTH LATE THIS EVENING AND THEN ACROSS CENTRAL PORTIONS OF FA AFTER MIDNIGHT. ACROSS THE FAR SOUTH...ANY CHANGEOVER WOULD BE LATE TONIGHT OR FRIDAY MORNING. SNOWFALL ACCUMULATIONS ARE PROBLEMATIC AS DRY AIR IN PLACE AND RELATIVELY WARM GROUND TEMPERATURES WILL LIKELY CUT BACK ON ANY ACCUMULATIONS. HOWEVER...THIS WILL BE COUNTERED BY THE FACT THAT THE SNOW WILL BE FALLING DURING THE NIGHTTIME PERIOD AND POSSIBILITY FOR SOME CONVECTIVE ENHANCEMENT. ACROSS THE FAR NORTH...WHERE CHANGEOVER SHOULD OCCUR THE EARLIEST...WILL GO WITH 1 TO 2 INCHES WITH UP TO AN INCH DOWN TO ABOUT I-70. FARTHER TO THE SOUTH...CHANGE OVER SHOULD BE LATE ENOUGH TO LIMIT ANY ACCUMULATIONS. WILL HANG ON TO SOME LOWER CLOUDS THROUGH THE MORNING ON FRIDAY WITH LINGERING LOWER LEVEL MOISTURE AND CAA. WILL ALSO UNDERCUT GUIDANCE TEMPS A FEW DEGREES FOR HIGHS FRIDAY. OTHERWISE...HIGH PRESSURE THEN BUILDS IN THROUGH THE REMAINDER OF THE SHORT TERM FOR QUIET WEATHER INTO THE WEEKEND. && .LONG TERM (SUNDAY THROUGH THURSDAY)... MODELS HAVE TRENDED STRONGER AND SLOWER WITH THE STORM SYSTEM EARLY NEXT WEEK. THIS SUPPORTS YESTERDAYS 12Z RUN WHICH WAS SLOWER WITH THE ONSET OF PCPN. THEREFORE DELAYED THE ONSET OF PCPN UNTIL MONDAY NIGHT. GFS HAS BEEN TRENDING FARTHER SOUTH WITH THE LOW. 06Z RUN HAS THE LOW IN CNTRL KY AT 12Z TUE...12Z GFS NOW HAS IT IN ERN TN. WENT A BLEND OF 06Z/12Z GFS RUNS...SO WAS COOLER THAN THE 00Z MEX FOR HIGHS TUE. THE BLEND OF THE THICKNESSES PUTS THE RAIN/SNOW LINE AROUND THE OHIO RIVER FOR TUE...BUT THEREFORE SHOULD BE A CHANGE OVER TO ALL SNOW ON THE BACKEDGE. LOW PULLS OF THE EAST COAST TUESDAY NIGHT. WITH COLD NW FLOW...MODELS ARE SUGGESTING THAT THERE MIGHT BE SOME LAKE EFFECT SHOWERS WED AND THU. OTHER THAN BEING COOLER WITH TUE MAXS...WENT CLOSE TO MEX NUMBERS. SITES && .AVIATION (18Z-18Z)... VFR CONDITIONS WILL CONTINUE INTO THE EVENING. EXPECT RAIN TO DEVELOP AND SPREAD INTO THE TAF SITES NEAR OR SHORTLY AFTER 00Z WITH LITTLE OR NO RESTRICTION TO VISIBILITY. CEILINGS WILL LOWER BY THIS TIME BUT STILL BE VFR. AS LOW PRESSURE MOVES EAST OF THE TERMINALS EXPECT CEILINGS TO BECOME MVFR. COLDER AIR WILL CAUSE A CHANGE OVER TO SNOW AT ALL BUT CINCINNATI BEFORE THE PRECIPITATION TAPERS OFF. THERE COULD BE SOME LINGERING FLURRIES ASSOCIATED WITH A TROUGH TRAILING THE LOW PRESSURE SYSTEM. DRIER AIR WILL MOVE IN AFTER 12Z RESULTING IN CEILING LIFTING BACK TO VFR AND SOME LOCATIONS MAY BECOME SCATTERED BEFORE THE END OF THE FORECAST PERIOD. && && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh