AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 950 AM EST SUN MAR 26 2000 EARLIER PATCHY FOG HAS DISSIPATED EXCEPT FOR A COUPLE OF SITES STILL REPORTING MVFR. 12Z SURFACE ANALYSIS SHOWS AN WEST/EAST COLD FRONT STRETCHING ACROSS MS/AL/GA...WITH MOISTURE POOLING SOUTH OF THIS FRONT...I.E. OVER THE CENTRAL AND EASTERN GULF COAST. SIGNIFICANT CONVECTION WITH FREQUENT LIGHTNING IS OCCURRING OVER SOUTHEAST TX...CENTRAL LA...AND SOUTHERN MS...WITH RAINFALL AMOUNTS OF 0.50 TO 0.75 INCH REPORTED DURING THE LAST 6 HOURS. EXPECT CONVECTION TO INCREASE AND SPREAD EASTWARD WITH DIURNAL HEATING AND CONTINUED MOISTURE INFLUX AGAINST THE FRONT. TLH 12Z SOUNDING SHOWS CONTINUED INCREASE IN MOISTURE OVER THE PAST 12 HOURS...GREATER INSTABILITY... AND SUBSIDENCE INVERSION AT 970 MB...ALREADY BROKEN. LATEST RUC SHOWS PRECIPITATION STAYING WEST OF THE APALACHICOLA FOR THE NEXT COUPLE OF HOURS...WITH GENERALIZED LIGHT RAINS SPREADING OVER MOST OF THE FORECAST AREA BY MID-AFTERNOON. ZONES AND COASTALS LOOK ON TRACK...NO BIG CHANGES NEEDED ON UPDATE. WILL INVESTIGATE SCEC FOR AFTERNOON WHEN NEW MODEL DATA ARRIVES. FIRE WEATHER: NO CURRENT PROBLEMS. FORECAST RAINS SHOULD KEEP FUELS WET. .TLH... AL...NONE. GA...NONE. FL...NONE. AFD fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KEY WEST FL 930 AM EST SUN MAR 26 2000 CURRENTLY... SURFACE ANALYSIS PLACES THE ATLANTIC RIDGE NEAR GRAND BAHAMA ISLAND TO WEST PALM BEACH. A WEAK HIGH PRESSURE CELL HAS FORMED IN THE SOUTHEAST GULF OF MEXICO...WITH A RIDGE NOSING INTO THE KEYS. A COL REGION BETWEEN THE TWO RIDGES LIES JUST EAST OF THE UPPER KEYS. AS OF 9 AM C-MAN STATIONS ALONG THE REEF ARE REPORTING WINDS NNE 5-10 KT...SHOWING THAT THE WEAK GULF RIDGE IS DOMINATING THE FLOW OVER THE KEYS AT THIS POINT...AND ALSO THERE MAY BE SOME EFFECTS OF LAND BREEZE OFF THE PENINSULA OVER FLORIDA BAY AND THE UPPER KEYS AS WELL. SHIP REPORTS SHOW WINDS LIGHT FROM THE ESE OVER THE FLORIDA STRAITS. VISIBLE SATELLITE PIX INDICATE A LONG NARROW CUMULUS LINE WHERE THE WEAK WIND FIELDS CONVERGE PARALLEL AND JUST A FEW MILES OFFSHORE FROM THE MID AND UPPER KEYS EXTENDING NORTH OVER THE STRAITS BETWEEN THE PENINSULA AND THE BAHAMA BANKS. SATELLITE SHOWS A REGION OF LOW CUMULUS AND STRATOCUMULUS CEILINGS OVER THE STRAITS SOUTHEAST THROUGH SOUTH OF THE LOWER KEYS TO THE NORTH COAST OF CUBA. THERE MAY BE LIGHT SHOWERS IN THIS AREA. CONSIDERABLE CIRRUS IS STREAMING ACROSS THE GULF TOWARD NORTH AND CENTRAL FLORIDA. FIRST PERIOD FORECASTS... THE ETA AND MESO-ETA HAVE NOT DEPICTED THE WEAK PRESSURE PATTERN VERY WELL AROUND THE KEYS. THE LATEST RUC HOWEVER...IS ON TRACK WITH THE LIGHT NNE FLOW OVER THE KEYS FOR THE CURRENT TIME. THE RUC...BY 18Z TO 21Z TODAY...INDICATES THAT THE LIGHT NNE FLOW OVER THE KEYS WILL FINALLY TURN SSE. I WILL INDICATE THIS TREND IN THE 1030 AM COASTAL MARINE ISSUANCE...OPTING TO USE "VARIABLE WINDS" FOR THE MID DAY AND EARLY AFTERNOON TRANSITION PERIOD. AS THE SURFACE WINDS TURN AROUND...THE CONVERGENT LINE SHOULD DISSIPATE...BUT THE HIGHER DEWPOINTS AND "PARTLY CLOUDY" CONDITIONS LURKING JUST TO THE SOUTH OF THE KEYS SHOULD MOVE IN. NO UPDATES ARE CURRENTLY INDICATED FOR THE PUBLIC ZONE FORECASTS. .EYW...NONE. CLB fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND 1024 AM MST SUN MAR 26 2000 LATEST RUC INDICATING BL WINDS OF 30 KTS. THIS IS VERIFYING LOW ACCORDING TO 88D VAD AND MCK PROFILER. HAVE UPDATED ZONES TO INCLUDE WIND ADVISORIES AND REMOVE BECOMING REFERENCES. .GLD...WIND ADVISORY TODAY...E CENTRAL CO...NW KS...SW NE...N CENTRAL KS... SVEN ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 220 PM CST SUN MAR 26 2000 CONVECTIVE COMPLEX OVER SW MISSOURI AT 20Z CONTINUES TO TRUCK EASTWARD THROUGH SURFACE BASED INSTABILITY AXIS WITH LI TO MINUS 10. THIS INSTABILITY AXIS IS PROGGED TO SHIFT SLOWLY SOUTHEASTWARD AND WEAKEN THIS EVENING. APPEARS 12Z ETA HAS SOMEWHAT UNDERFORECAST INSTABILITY ACROSS WRN MISSOURI...SO PREFER THE MORE UNSTABLE RUC LIFTED INDEX PROGS. RUC LOWERS LI/S TO MINUS 6 OVER SE MISSOURI BY MIDNIGHT. THIS SHOULD BE MORE THAN ADEQUATE TO SUSTAIN COMPLEXES MOVING E/SE FROM WESTERN MISSOURI LATER THIS EVENING. PLAN TO MENTION SEVERE WORDING IN FAR WEST ZONES AROUND POPLAR BLUFF FOR TONIGHT. EAST OF THE MISSISSIPPI RIVER...MODELS INDICATE LOW LEVEL MOISTURE AND INSTABILITY WILL HAVE DIFFICULTY BECOMING ESTABLISHED PRIOR TO THE COLD FRONT. EASTERLY COMPONENT TO LOW LEVEL FLOW HAS KEPT SFC DEW POINTS ONLY IN THE 30S THIS AFTERNOON OVER WEST KENTUCKY. FLOW SHOULD BACK AROUND IN TIME TO BRING MARGINALLY UNSTABLE AIR INTO THE LOWER OHIO VALLEY. HOWEVER...STRONGEST STORMS SHOULD BE CONFINED TO BETTER MOISTURE AND INSTABILITY FIELDS SOUTH AND WEST OF PAH. ONCE COLD FRONT PASSES EAST OF THE FA BY 12Z...ALL MODELS SHOW RAPID DRYING FROM THE LOW LEVELS ON UP. BASED ON MODEL RH PROGS...WILL HAVE TO YANK MORNING POPS ACROSS EASTERN COUNTIES AND GO MORE OPTIMISTIC FOR SKY CONDITIONS MONDAY. MODEL SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES MONDAY...WITH MIXING HEIGHTS OVER 5K FEET. THIS SHOULD ALLOW STRONGER 20 PLUS KNOT WINDS TO MIX DOWN...SO WILL MENTION BREEZY CONDITIONS IN ALL AREAS. A SECONDARY VORT LOBE AND ASSOCIATED SURFACE TROUGH IS PROGGED TO SWING SOUTHEAST ACROSS SRN INDIANA MONDAY NIGHT. THIS WILL BRING PLENTY OF CLOUDS...AND KEEP TEMPS UP A LITTLE HIGHER THAN NGM MOS SHOWS. NGM MOS CLOUD FORECASTS APPEAR OUT TO LUNCH MONDAY NIGHT. EXTENDED PROGS... UPPER LOW OVER THE NORTHEAST WILL KEEP A RELATIVELY COOL NORTHWEST FLOW IN PLACE FOR MUCH OF THE PERIOD. NCEP SOLUTION CALLS FOR PIECES OF ENERGY COMING OUT OF THE SOUTHWESTERN TROUGH TO PASS SOUTH OF THE OHIO VALLEY...UNDERCUTTING THE NORTHEASTERN UPPER LOW. COULD HAVE SOME OVERRUNNING RAIN OR EMBEDDED ELEVATED CONVECTION WEDNESDAY THROUGH FRIDAY...ESPECIALLY SOUTHERN ZONES. .PAH...NONE. MY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1007 PM EST SUN MAR 26 2000 RADAR RETURNS HAVE BEEN A BIT DECEIVING THIS EVENING...SHOWING REFLECTIVITIES OF NEARLY 50 DBZ BUT NO LIGHTNING DETECTED. APPEARS CONVECTION OVER MO AND IL IS "STEALING OUR THUNDER" SO TO SPEAK. HIGHEST SFC DWPTS (IN THE 50S) AND GREATEST THETA E RIDGING HAVE REMAINED S OVER THE MID MISSISSIPPI VALLEY ALL EVENING. VERTICALLY STACKED LOW WILL VERY SLOWLY DRIFT NE THRU LAKE SUPERIOR OVERNIGHT...BUT THE COLD FRONT WILL SWEEP E ACROSS MI REACHING THE LAKE HURON COAST BY MORNING. ALONG AND AHEAD OF THE FRONT...SHRA AND POSSIBLY SOME EMBEDDED TSRA WILL CONTINUE TO DEVELOP AS THE THETA E RIDGE MOVES THRU AND LI'S HOLD AROUND ZERO TO +1. EARLIER UPDATED ZONE FORECAST IS IN LINE WITH LATEST RADAR TRENDS AND RUC RUN. NO ADDITIONAL UPDATE WILL BE NEEDED AT THIS TIME. .APX...NONE. EME mi FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 830 PM CST SUN MAR 26 2000 .FIRST PD... POPCORN SHWRS ARE DSPTG RPDLY WITH SFC COOLING. SHOULD END BY 03Z. UPR LOW OVR CNTRL MB DROPPING SSE ACCORDING TO SATL TRENDS. LATEST RUC AND MESO ETA ARE TOO FAR E IN THE MODL OF CLD CVR ASSOCIATED WITH THE UPR LOW AND SFC TROF. WHAT THIS MEANS FOR FIRST PD FCST IS CLDS LIKELY TO MOV FARTHER W THAN ZONES DESCRIBE. WILL BRING CLDS AND FLRYS BACK INTO NERN ND AFT MIDNIGHT. OTW RST OF ZONES SET LOOKS GOOD AND TEMPS ARE ON TRACK. ZFP OUT BY 03Z. .FGF...NONE. BELLES/BRAZZELL nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1005 PM EST SUN MAR 26 2000 A FEW MINOR CHGS TO TON FCST REQD. RAD MOSAIC INDICATES SLOW NWD MVMT OF PCPN AREA ACRS S/CENT GA. BOTH 00Z ETA AND LTST RUC KEEP PCPN OUTSIDE OUR CWA THRU 12Z...ALTHOUGH PREV RUC HAD SUGGESTED PCPN MOVG INTO CSRA LATE TON. ALTHOUGH DIURNAL TREND TOWARDS DISSIPATION SHOULD CONT...PROXIMITY OF PCPN AREA WITH SLOW NWD MVMT SUGGESTS INTRODUCING SMALL POP FOR LWR GA CSRA COUNTIES. SATL INDICATES TEMPORARY BREAK IN UPPR LVL CLDS IN STORE OVR THE NEXT FEW HRS. LOW/MID LVL CLDS HAVE MOVD N INTO MCN/VID IN S CENT GA. KJGX VWP INDICATES SW FLOW...THESE CLDS COULD VENTURE AT LEAST INTO W HLF CWA LATE TON PER 00Z ETA...OR STREAM OVR ENTIRE CWA AS PER LTST RUC. LT WINDS TON WITH CLD BREAK WILL ALLOW TEMP FALL TO NR FCST MINS W/CENT. NE CWA WILL BE LAST TO SEE LWR LVL MOIST/CLD INCR. LWR TDS WILL ALSO ALLOW MORE TEMP FALL THERE. WILL BREAK OFF NE CWA TON FOR LWR MIN. .CAE...NONE. MILLER sc AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1210 PM CST SUN MAR 26 2000 ...UPDATED TO EXPAND WIND ADVISORY AREA... STRONGER WINDS STARTING TO MIX DOWN TO THE SURFACE. 12Z RAOB FROM KUNR HAD 40 KTS AT 850MB...INITIALIZED WELL BY 12Z MODELS. FORECAST SOUNDINGS FROM 12Z ETA AND 15Z RUC SHOW PROFILES BECOMING ADIABATIC TO 850-800 MB WITH LOW LEVEL COLD ADVECTION IN 15Z-21Z TIME FRAME... WITH 40-45KTS AT THESE LEVELS. NELIGH PROFILER ALSO SHOWING 50KTS IN LOWEST GATES DURING LAST TWO HOURS. WINDS IN SOUTH CENTRAL SOUTH DAKOTA ALREADY REACHING ADVISORY CRITERIA... AIDED BY 5-6MB/3HR PRES RISES BEHIND THE FRONT. ALL THIS LEADS TO DECISION TO ISSUE WIND ADVISORY FOR REMAINDER OF TODAY. QUESTION IS HOW FAR EAST. WITH SLIGHTLY WEAKER GRADIENT IN PROXIMITY TO FRONT REFLECTED IN 850MB WINDS OF 35KTS ON 18Z FORECAST. FOR NOW...WILL KEEP IT ACROSS SD AND ONE TIER OF COUNTIES INTO MN AND IA...BUT CONTINUE TO MONITOR FARTHER EAST FOR POSSIBLE EXPANSION. WILL WORD ADVISORY INTO EARLY THIS EVENING...AS BEST SUBSIDENCE BEHIND UPPER WAVE FORECAST OVER AREA AT 00Z. .FSD...WIND ADVISORY INTO EARLY EVENING ENTIRE CWA HAMEN sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1020 AM CST SUN MAR 26 2000 STRONGER WINDS STARTING TO MIX DOWN TO THE SURFACE. 12Z RAOB FROM KUNR HAD 40 KTS AT 850MB...INITIALIZED WELL BY 12Z MODELS. FORECAST SOUNDINGS FROM 12Z ETA AND 15Z RUC SHOW PROFILES BECOMING ADIABATIC TO 850-800 MB WITH LOW LEVEL COLD ADVECTION IN 15Z-21Z TIME FRAME... WITH 40-45KTS AT THESE LEVELS. NELIGH PROFILER ALSO SHOWING 50KTS IN LOWEST GATES DURING LAST TWO HOURS. WINDS IN SOUTH CENTRAL SOUTH DAKOTA ALREADY REACHING ADVISORY CRITERIA... AIDED BY 5-6MB/3HR PRES RISES BEHIND THE FRONT. ALL THIS LEADS TO DECISION TO ISSUE WIND ADVISORY FOR REMAINDER OF TODAY. QUESTION IS HOW FAR EAST. WITH SLIGHTLY WEAKER GRADIENT IN PROXIMITY TO FRONT REFLECTED IN 850MB WINDS OF 35KTS ON 18Z FORECAST. FOR NOW...WILL KEEP IT ACROSS SD AND ONE TIER OF COUNTIES INTO MN AND IA...BUT CONTINUE TO MONITOR FARTHER EAST FOR POSSIBLE EXPANSION. WILL WORD ADVISORY INTO EARLY THIS EVENING...AS BEST SUBSIDENCE BEHIND UPPER WAVE FORECAST OVER AREA AT 00Z. .FSD...WIND ADVISORY INTO EARLY EVENING ALONG AND WEST OF KPQN TO KSUX LINE. HAMEN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 925 PM CST SUN MAR 26 2000 HAVE UPDATED ZONES TO ADJUST WINDS TO MORE NLY/NELY COMPONENT REST OF TONIGHT CNTRL/ERN SECTIONS. APPEARS CDFNT NR LAW-LBB-W CVS LINE. THIS POSITION APPEARS FASTER THAN LAMP/RUC PROGS. SOME INCREASE IN CIRRUS PER IR STLT IMAGERY BUT WILL NOT CHANGE SKY FORECAST. BF .MAF... TX...NONE NM...NONE tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 930 PM CST SUN MAR 26 2000 UPDATE OUT SOON FOR CLEANING UP EVENING PCPN TRENDS AND WORDG. MAIN PROBLEM IS WIND ADVSRY LATER IN EFFECT FOR THE CWA. RUC MODEL INDICATES BEST PRES GRAD REMAINS ACRS NE WI TNT INTO MONDAY AS WELL INTO TUESDAY...BUT WILL HAVE TO WAIT TIL NEXT S/W WAVE NORTH OF MN MERGES INTO THE GRT LAKES. RUC ALSO INDICATES H8 WINDS OF 50 KNTOS BY 12Z MONDAY FOR FAR NE WI WHILE LATEST ETA HAS 50 KNOTS AT 06Z TNT...THEN DIMNSHG AT 12Z. AS FAR AS LATEST TRENDS...SFC LOW IS DEEPENING OVER UPR MICH... SUPPORTING AN INCREASING PRES GRAD...EVEN THOUGH WINDS DECOUPLG A BIT. H8 00Z ANALYSIS SHOWS 40 KNOTS WINDS OVER WRN MN IN WAKE OF INITIAL TROF. HIGHER TERRAIN NORTH WOULD HAVE BEST CHANCE OF WINDS MIXING DOWN MONDAY SO WL CONT TO HAVE ADVSRY LATE TNT INTO MONDAY ALTHOUGH WINDS PROBABLY BE NEAR ADVSRY CRITERIA FAR NE LATER MONDAY MORNING. NOT SEEING CLEAR CUT SOLUTION TO DROP THE ENTIRE ADVSRY SO WILL SCALE BACK CENTRAL WI AREAS...AND KEEP ADVSRY FOR NORTH AND EAST IN BETTER GRADIENT. .COORDINATED WITH ARX...MQT. .GRB...WIND ADVISORY WI ZNS...005..010>013..018>022..031.. HELMAN WWW.CRH.NOAA.GOV/GRB wi SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 245 AM MST MON MAR 27 2000 .TDY AND TUE... RIDGE BUILDING OVER STATE TODAY FOR ANOTHER MILD DAY WITH MOISTURE TRYING TO OVERRIDE THE RIDGE IN RESPONSE TO SHORTWAVE APPROACHING THE COAST. WITH DOWNSLOPE GRADIENTS IN PLACE GOOD MIXING SHOULD AGAIN OCCUR AND WITH 700 MB TEMPERATURES 5 DEGREES WARMER THAN SUNDAY FORECASTED TEMPS +8 TO +10 OVER YESTERDAY LOOK GOOD. FORECAST PROBLEMS BEGIN ON TUESDAY AS MODELS ARE DIVERGENT IN TIMING AND AMPLIFICATION THAT OCCURS TO SYSTEM APPROACHING COAST. NEW 06Z ETA AND LATEST RUC SUPPORT THE 00Z ETA SOLUTION VERSUS THE FASTER AND LESS AMPLIFIED AVN/NGM SCENARIO. OVERALL...ALL OF THE MODELS AGREE THAT A JET SEGMENT APPROACHES THE REGION AND INTERACTS WITH A LOW LEVEL BAROCLINIC ZONE TO DEVELOP IMPRESSIVE VERTICAL MOTION. THE ETA SOLUTION IS SLOWER...AND WOULD ALLOW FOR AN INITIAL WARMUP EARLY ON TUESDAY FOR CENTRAL AND EASTERN SECTIONS OF FORECAST AREA...WITH SOUTHEAST MONTANA LIKELY SEEING TEMPERATURES AT LEAST AS WARM AS TODAY. AS DYNAMICS APPROACH CENTRAL MONTANA DURING THE DAY ON TUESDAY...DEEP INVERTED SURFACE TROF DEVELOPS OVER EAST WITH IMPRESSIVE CONVERGENCE AND FRONTOGENESIS OCCURRING WEST OF SURFACE TROF IN WESTERN SECTIONS OF CENTRAL MONTANA. DUE TO LACK OF MODEL AGREEMENT...CURRENT POPS FAVORING BEST CHANCE FOR SCATTERED SHOWERS OVER WESTERN SECTIONS OF FORECAST AREA LOOKS GOOD. LAPSE RATES AND LIFTED INDICES INDICATE THERE COULD BE A ISOLATED THUNDERSTORM IN THE EASTERN TWO-THIRDS OF THE FORECAST AREA...BUT WILL LEAVE THIS TO SUBSEQUENT SHIFTS AND NEWER MODEL RUNS. WILL BOOST THIRD PERIOD TEMPS...ESPECIALLY IN EASTERN SECTIONS. BORSUM. .WED...THU...AND FRI... NEW MRF IS FAIRLY CONSISTENT FROM PREVIOUS RUN. DIFFERENCES NOT QUITE AS BAD BETWEEN MODELS THIS TIME AROUND...ESPECIALLY THURSDAY AND FRIDAY PERIODS. MRF ALSO STILL POINTING (3RD RUN IN A ROW) TO PATTERN/WEATHER CHANGE LATER THIS WEEKEND. WEDNESDAY...ONE SHORTWAVE EXITING EASTERN PORTIONS AS ANOTHER WAVE DROPS INTO WESTERN AREAS FOR CHANCE OF SHOWERS AND COOLER WEATHER. THURSDAY AND FRIDAY...MRF/ECMWF/NOGAPS BOTH POINTING TO UPPER RIDGE NOSING INTO AREA AS HIGH OVER LOW FORMS WESTERN US. THIS SHOULD KEEP MT MAINLY DRY AHEAD OF NEXT STRONG SYSTEM THAT IS PROGGED TO DIVE INTO AREA SATURDAY/SUNDAY. WITH A LITTLE MORE CONFIDENCE THIS TIME AROUND...WILL GO AHEAD AND UPDATE LAST 2 PERIODS OF EXTENDED FOR MAINLY DRY AND WARMER TEMPERATURES. RASCH BIL UEWBB /068 039/063 033/053 030/057 030/058 59003 56 LVM UWWBB /066 036/059 032/051 028/055 028/057 59024 56 HDN UEWBB /069 038/064 031/053 028/057 028/058 59003 56 MLS UBWBB /066 037/069 035/053 033/056 031/057 59002 56 4BQ UBWBB /065 036/067 035/052 032/055 030/056 59002 56 BHK UBWBB /063 035/065 034/051 031/054 029/055 59002 56 SHR UBWBB /067 034/067 030/052 028/055 027/056 59003 56 mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 337 AM CST MON MAR 27 2000 SURFACE RIDGE BUILDING RAPIDLY INTO THE FORECAST FROM THE NORTHWEST WILL BE THE PRIMARY INFLUENCE ON TODAY'S WEATHER. RECENT RUC/ETA GUIDANCE SUGGESTS THE CENTER OF THE HIGH WILL BUILD RIGHT OVER SOUTHWEST/SOUTH CENTRAL OKLAHOMA THIS AFTERNOON. CONSIDERABLE CHANGES IN THE WEATHER BEGIN TONIGHT. FIRST A COLD FRONT OVER SOUTHERN CANADA MOVES INTO NORTHERN OKLAHOMA AFTER MIDNIGHT RESPONSIBLE FOR COOLER TEMPERATURES AND A WIND SHIFT. EXPECT LITTLE IN THE WAY OF CLOUD COVER AND PRECIP ALONG THE FRONT THIS EARLY...AS ABUNDANT LOW LEVEL MOISTURE AND INSTABILITY WILL NOT YET BE AVAILABLE. THE FRONT SHOULD CONTINUE MOVING SOUTHWARD ON TUESDAY AND SHOULD CLEAR MOST IF NOT ALL OF THE FORECAST AREA. MODELS ARE CONSISTENT IN MAINTAINING A MODEST NORTHWEST FLOW ON THE BACK SIDE OF A SLOW MOVING UPPER LEVEL TROUGH OVER THE GREAT LAKES. THIS SHOULD MAKE IT RELATIVELY EASY FOR A COMPLETE FRONTAL PASSAGE. ALSO BY TUESDAY...AN UPPER LEVEL TROUGH NOW OFF THE COAST OF CALIFORNIA WILL BE KICKED EASTWARD WITH A LEAD SHORTWAVE TROUGH EXPECTED TO REACH WESTERN OKLAHOMA LATE IN THE DAY. MODELS DEPICT A SLIGHTLY WEAKER SOLUTION WITH THIS FEATURE...BUT STILL PRODUCE MODEST FORCING AND QPF OVER WESTERN PARTS OF THE AREA. WILL KEEP HIGHEST POPS TUESDAY NEAR HOBART AND GAGE WHICH SHOULD BE NORTH OF THE SURFACE COLD FRONT AND CLOSER TO MID AND UPPER LEVEL FORCING FROM A SHORTWAVE TROUGH. WILL KEEP LOWEST POPS NEAR PONCA CITY WHICH SHOULD STILL BE RELATIVELY DRY IN THE LOWER HALF OF THE TROPOSPHERE. RECENT AVN/MRF SUGGESTS TUESDAY NIGHT THROUGH THURSDAY WILL REMAIN SOMEWHAT COOL AND MOIST WITH THE ABOVE MENTIONED COLD FRONT SLIDING FARTHER SOUTH INTO TEXAS. PLAN TO MAINTAIN PESSIMISTIC SKY CONDITION AND CHANCE POPS FOR ALL AREAS TUESDAY NIGHT THROUGH THURSDAY WITH A LONGWAVE TROUGH REMAINING WEST OF THE FORECAST AREA. OKC 72 46 66 48 / 0 0 20 40 HBR 76 46 66 47 / 0 0 40 40 SPS 78 48 70 51 / 0 0 30 30 GAG 75 42 64 45 / 0 0 40 40 PNC 72 44 68 45 / 0 0 20 40 DUA 72 45 70 51 / 0 0 20 30 .OUN... OK...NONE. TX...NONE. JAMES ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 230 AM EST MON MAR 27 2000 SHOWERS ARE CURRENTLY OCCURRING JUST SOUTH OF THE FORECAST AREA ALONG A WARM FRONT. THE RUC SHOWS THIS FRONT BECOMING MORE DIFFUSE AND DEVELOPING NORTH OF THE FORECAST AREA BY 15Z THIS MORNING SO EXPECT PCPN ASSOCIATED WITH THIS FRONT WILL DIMINISH. BELIEVE THE BEST CHANCE OF RAIN WILL BE AHEAD OF THE APPROACHING COLD FRONT AND DPVA MOVING INTO THE AREA LATER TODAY. THE MODELS SHOW THE BEST LIFT AND INSTABILITY LATE THIS AFTERNOON. THE MODEL/S FORECAST OF ONLY WEAK INSTABILITY WITH LI/S AROUND -2 AND TT/S IN THE UPPER 40S IS PROBABLY CORRECT DUE TO CLOUDINESS AND VERY WEAK LOW-LEVEL WARM ADVECTION. ALSO...THE MODELS FORECAST STRONG UPPER SUPPORT WILL REMAIN NORTH OF THE FORECAST AREA. SATELLITE/LIGHTNING TRENDS SUPPORT THIS WITH THE STRONGER STORMS IN THE OHIO VALLEY HEADING TOWARD THE AREA NORTH OF THE FORECAST AREA. ALSO...THE STRONGER STORMS IN THE LOWER MISSISSIPPI VALLEY APPEAR TO BE MOVING TOWARD THE BETTER INSTABILITY AND THE AREA SOUTH OF THE FORECAST AREA. DRYING WILL OCCUR TONIGHT BEHIND THE COLD FRONT. A RE-ENFORCING COLD FRONT WILL APPROACH TUESDAY AND EXPECT THE PRESSURE GRADIENT WILL TIGHTEN ENOUGH FOR IT TO BECOME BREEZY TUESDAY AFTERNOON. PLAN TO USE A CONSENSUS OF LOCAL AND FWC/FAN GUIDANCE FOR TEMPERATURES AND POPS THROUGH THE PERIOD. CAE...73/45/71/39 720 AGS...73/46/72/40 710 .CAE...NONE. RJL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 330 AM CST MON MAR 27 2000 COMPLICATED WEATHER PATTERN THIS FCST PD AS STRONG JET ENERGY MVG SE THRU NW UPPER FLOW TRIES TO PHASE OVER NR GREAT LAKES. 500MB LOW CENTER APPEARS TO BE ALONG WI AND MI BORDERS AT 09Z WITH ANOTHER WEAKER SHORTWAVE TROUGH NE OF LK WINNIPEG MVG SE. THESE PHASE TO SOME DEGREE NR SSM (OR SHOULD I SAY Y62?) LATE THIS AFTERNOON. SHORT WAVE NE OF LK WINNEPEG IS QUITE VIGOROUS AND INDUCING PRESSURE FALLS ACROSS NRN MN AND BACKING SFC WINDS ACROSS THE ENTIRE AREA. NEW RUC AND SMALL SCALE ETA ARE DEEPER WITH 500MB CENTER AND SFC LOW AND ALSO A BIT FURTHER S WITH BOTH (WHICH MAKES SENSE IF SHORT WAVE NE OF LK WINNEPEG MAY BE STRONGER THAN NGM/AVN DEPICT). NCEP LIKES THE ETA THE BEST...BUT THERE ISN/T AN INCREDIBLE DIFFERENCE IN THE MODELS BESIDE THAT MENTIONED ABOVE. WILL DROP WIND ADV AS UPSTREAM SHORT WAVE PRODUCING BACKING WINDS AHEAD OF IT AND INCREASING DIRECTIONAL WIND SHEAR WILL KEEP FULL FORCE OF WINDS FROM MIXING DOWN TO SFC. IN ADDITION...THERMAL TROUGHING FROM THE GREAT LAKES ALSO KEEPING SFC WINDS FM BEING WELL ALIGNED WITH 850MB WINDS. WILL GO WITH 20 TO 30 MPH IN MOST PLACES WITH HIGHER GUSTS MENTIONED. TEMPS TODAY SHOULD BE FAIRLY CLOSE TO MOS GUIDANCE...BUT WILL BE LOWER WHERE THERE IS APPRECIABLE CLOUDS (IN THE N). CLOUDS WILL INCR IN THE WK WINNIPEG SHORT WAVE APPROACHES AND RW-/SW- SHOULD ARRIVE IN WRN 1/2 OF CWA IN THE AFTERNOON. WILL GO WITH SMALL CHANCE OF RW-/SW- LATE IN DAY IN EAST. THINK MOST OF CWA WILL SEE LIGHT SNOW TONIGHT AS JET SREAK ROTATES AROUND UPPER LOW AND ENTERS THE FCST AREA FM THE NE. WILL GO WITH 1-3 INCHES IN THE N AND AN INCH OR LESS FURTHER S. IF IT WAS A LITTLE COLDER WOULD BE THINKING MORE ABOUT LAKE ENHANCEMENT IN VILAS COUNTY...BUT IT LOOKS LIKE THE LAKE WON/T ADD TOO MUCH. MIGHT GO WITH 2-4 IN UP THERE. WINDS SHOULD BE GUSTY AGAIN DURING THE LATE AFTERNOON AND EVENING...AND WE MIGHT NEED TO REISSUE A WIND ADV LATER TODAY. TEMPS TONIGHT SHD BE PRETTY CLOSE TO MOS GUIDANCE. TUE SHOULD BE BLUSTERY AND COLD WITH TEMPS SEVERAL DEG COLDER THAN MOS...ESP IN E WHERE IT SHOULD BE CLOUDY ALL DAY. WILL KEEP MENTION OF SNOW SHOWERS OR FLURRIES. COORDINATED WITH MQT...THANKS. .GRB...NONE RDM WWW.CRH.NOAA.GOV/GRB wi FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 955 AM CST MON MAR 27 2000 FORECAST CHALLENGE FOR UPDATE CONCERNS WIND...SNOW EXTENT AND TEMPS. STRONG CYCLONIC FLOW PROVIDING PLENTY OF CHALLENGES FOR FA TODAY. KMVX-88D INDICATING NARROW BAND OF ENHNACED SNOWFALL DROPPING SOUTH THROUGH FA ASSOCIATED WITH SFC COLD FRONT AND VORT CENTER QUITE EVIDENT FROM WV LOOP. VSBY BRIEFLY DROPPED TO 1/2 MILE AT GFK HOWEVER ACCUMULATION BEEN ONLY A DUSTING AT BEST. AS VORT DROPS SOUTH NVA TO FOLLOW AS VISIBLE IMAGERY SHOWING BREAKS UPSTREAM WITH CLD COVER MORE CUMULIFORM IN NATURE. HOWEVER LATEST RUC INDICATING MOIST LAYER BETWEEN H8-9 AND WITH H8 COLD POOL DROPPING OVR FA ANY BREAKS LIKELY TO FILL WITH -SHRASN POSSIBLE. VIS LOOP ALSO INDICATING SOME ENHANCED CU UPSTREAM SO INSPITE OF NVA WILL CONTINUE WITH RASN SHOWERS BEHIND MAIN BAND ALTHOUGH SHOULD BE MORE SPOTTY. STRONGEST CAA OVR NORTHERN FA ATTM AND WILL SPREAD SOUTH DURING DAY. TEMPS DROPPING SIGNIFICANTLY WITH THIS FEATURE AND WITH CLOUD COVER RECOVERY WILL BE SLIGHT. WILL NEED TO DROP MAX TEMPS ACROSS THE NORTH TODAY AND WILL LIKELY HOLD TEMPS FAIRLY STEADY ACROSS THE SOUTH. TIGHT GRADIENT ALONG WITH SIG PRESSURE RISES DROPPING SOUTH FROM MSAS. H85 12Z UA ANALYSIS NOT SHOWING REAL STRONG WINDS AT H8. HOWEVER KMVX VWP SHOWING A STEADY 30-35KT UP TO 10K. WITH LATEST RUC SOUNDING SHOWING ADIABATIC LAPSE RATES TO H85 AND WITH CAA SHOULD MIX DOWN. WILL CONTINUE WIND ADVISORY. .FGF...WIND ADVISORY TODAY FOR ALL OF ERN ND AND THAT PART OF NW MN ALONG AND WEST OF A ROX-DTL-FFM LINE. VOELKER nd DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 925 AM CST MON MAR 27 2000 SHORT TERM...SURFACE OBS FROM ACROSS THE STATE INDICATE THAT THE COLD FRONT HAS PENETRATED INTO SOUTH CENTRAL TEXAS GENERATING ONLY A WIND SHIFT AND MODERATE CLD COVER. MESO-ETA AND RUC GUIDANCE BRING A GRADUALLY WIND SHIFT TO THE WEST TO NORTHWEST ACROSS THE CWA WITH NORTHERLY WINDS PREVAILING AROUND 18Z. EARLY MORNING FOG HAS DISSIPATED OVER DEEP SOUTH TEXAS LEAVING ONLY A PATCHY AND THIN ST DECK OVER THE REGION. AFTERNOON HEATING WILL STEADILY ERODE THIS LEAVING BEHIND PARTLY TO MOSTLY SUNNY CONDITIONS. THE WIND SHIFT WILL LIKELY DO LITTLE TO DROP TEMPS ANY TODAY WITH 80S AND 90S PREVAILING. MARINE...SURFACE WINDS SHIFTING TO THE NORTHEAST TO EAST FROM THE ABOVE MENTIONED FRONTAL BOUNDARY ARE NOT STRONG ENOUGH TO GENERATE ROUGH BAY AND GULF CONDITIONS TODAY. SO WILL MAINTAIN CURRENT CWF WORDING. SYNOPTIC/MESO...60/INTERN...CASTILLO INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx AREA FORECAST DISCUSSION 945 AM CST MON MAR 27 2000 FORECAST PROBLEM FOR THE AFTERNOON IS EXTENT OF PRECIP AND INCREASING WIND. BASED ON RADAR COMPOSITE..LOOKS LIKE BETTER CHANCE OF RAIN/SNW SHOWERS MOVING DOWN A LITTLE FARTHER WEST. WILL INCREASE POPS OVER A FEW OF THE WST CENTRAL ZONES. 12Z RUC AND ETA SHOWING MAX LOW LEVEL COLD ADVECTION SLIDING INTO SOUTHWEST MINNESOTA AND STRONGEST 850 MB WINDS ALSO FORECAST IN THIS AREA FOR LATER THIS AFTERNOON. AREAS OF SOUTH CENTRAL MN WILL SEE A LITTLE MORE HEATING THIS MORNING WHICH WILL INCREASE THE LAPSE RATE. WILL GO AHEAD AND EXPAND THE WIND ADVISORY INTO SOUTH CENTRAL MN. LOW LEVEL THICKNESS INITIALLY A LITTLE ON THE WARM SIDE OVER PARTS OF THE SOUTH SO WILL KEEP THE MIX GOING. AREAS NORTH OF STC UP TO AXN PROBABLY ALL SNOW. MAY BE SOME FALLING TEMPS NORTH AND THEN NEARLY STEADY A FEW OTHER AREAS. .MSP...WIND ADVISORY THIS AFTEERNOON SW OF KAXN...KHCD...KMKT..KAEL JPR mn