AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 315 PM EST THU MAR 30 2000 THE LOW NOW OVER WESTERN FLORIDA PANHANDLE SHOULD MOVE ACROSS SOUTH GEORGIA/NORTH FLORIDA TONIGHT AND OFF THE COAST BY EARLY FRIDAY MORNING. HIGH PRESSURE BUILDS IN TOWARD MID ATLANTIC COAST...BUT QUITE A BIT OF LOW LEVEL MOISTURE REMAINS OVER THE AREA THROUGH FRIDAY. APPEARS BULK OF THE PRECIP SOUTHEAST OF OUR CWFA BUT SHORT WAVE DEPICTED BY RUC TO MOVE JUST NORTH OF OUR AREA THIS EVENING. WILL CARRY SMALL POP FOR NORTHEAST GA THIS EVENING DUE TO THIS FEATURE. FURTHER SOUTH WILL CARRY SMALL POP CLOSER TO THE FRONT. THEN DRY THROUGH SATURDAY. AVIATION SHOWS INCREASING HIGH CLOUDS SATURDAY AHEAD OF THE NEXT SYSTEM WITH CHANCE OF RAIN AGAIN SATURDAY NIGHT. CONCERNING TEMPERATURES...FWC/FAN NUMBERS ARE CLOSE ALL PERIODS AND WILL STICK CLOSE TO THEM. UPPER LEVEL RIDGE OVER THE STATE SATURDAY SO WARM TEMPERATURES LOOK OKAY. ATL 51/71 49/75 1000 AHN 48/72 47/76 2000 RMG 46/70 43/74 1000 CSG 53/74 51/78 2000 MCN 52/74 49/78 2000 .ATL...NONE. 26 ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 230 PM CST THU MAR 30 2000 18Z SURFACE CHART SHOWS HIGH PRESSURE RIDGING ACROSS THE GREAT LAKES. WATER VAPOR AND RUC MODEL SHOW VORT MAX SLIDING ACROSS SOUTHERN MISSOURI. SOME PRECIP WITH THE VORT MAX...SHOULD STAY SOUTH OF OUR CWA. AM EXPECTING SOME HIGH-LEVEL CLOUDINESS MUCH OF THE NIGHT. THIS...AND NUMERICAL GUIDANCE...MATCH WELL WITH GOING FORECAST AND WILL LEAVE THAT PART ALONE. MAIN PROBLEMS TODAY FOCUS ON SATURDAY AND EARLY NEXT WEEK. LOW PRESSURE...AND ASSOCIATED FRONT...WAS FORMING IN THE DAKOTAS TODAY. MODELS MOSTLY AGREEABLE THAT THIS WILL MOVE EAST THE NEXT COUPLE OF DAYS...AS THE HIGH PRESSURE RIDGE SLIDES UNDERNEATH THE LOW. BEST PRECIP CHANCES SHOULD MAINLY BE NORTH OF ILLINOIS...BUT PRESENCE OF SOME LIFT ON SATURDAY WARRANTS A LOW POP FOR THE NORTHERN CWA...AS IS IN THE CURRENT FORECAST. WILL GO CLOSER TO THE WARMER FAN NUMBERS FOR SATURDAY. GOING INTO THE EXTENDED...MRF HAS CHANGED SOME FROM YESTERDAYS RUN. CUT-OFF UPPER LOW IN THE SOUTHWEST U.S. WILL NOW MOVE EAST ALONG THE SOUTHERN STATES...RATHER THAN KICKING NORTHEAST. SECOND PIECE OF ENERGY TO MOVE ALONG THE U.S./CANADIAN BORDER...WITH MAIN SURFACE LOW STAYING WELL NORTH IN CANADA. WITH HIGH PRESSURE IN THE SOUTHEAST U.S. AFFECTING OUR AREA...WILL TAKE PRECIP OUT OF SUNDAYS FORECAST. NCEP AND MRF ARE SLOWER WITH NEXT SYSTEM...KEEPING IT NORTHWEST OF ILLINOIS AT 12Z MONDAY...WHILE EUROPEAN AND NOGAPS MODELS SHOW IT THROUGH MOST OF THE STATE. WILL GO THE SLOWER ROUTE...KEEPING SHOWERS/THUNDERSTORMS IN MONDAYS FORECAST...WITH RAIN AND COOLER WEATHER FOR TUESDAY. COORDINATED WITH DVN. ...PRELIMINARY CCF FOR COORDINATION ONLY... SPI AE 037/066 043/064 045 72000 PIA AE 036/066 041/062 043 72000 DEC AE 035/066 042/064 045 72000 CMI UE 033/064 041/064 045 72000 MTO UE 035/066 041/064 044 72000 LWV UB 035/066 041/067 047 72000 .ILX... IL...NONE. GEELHART/PLAHMER il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON 845 PM EST THU MAR 30 2000 IR/FOG LOOP SHOWING CLEAR SKIES ACROSS MOST OF THE CWA. CIRRUS ALONG THE SOUTHERN BORDER OF OUR CWA AT TIME PROGGED TO SLIP SLOWLY SOUTHWARD OVERNIGHT. HIGH PRESSURE CENTERED ACROSS THE GREAT LAKES WILL BUILD INTO THE AREA TONIGHT AND TOMORROW... PROVIDING CLEAR SKIES AND CALM CONDITIONS FOR THE AREA. MAIN CONCERN OVERNIGHT IS TEMPS. 01Z READINGS ARE COMPARABLE TO LAST NIGHT'S READINGS.. WHILE DEW POINTS ARE RUNNING A DEGREE OR 2 COOLER. 18Z ETA AND 21Z RUC SUGGEST THAT DEW POINTS MAY DROP OFF ANOTHER DEGREE OR 2 OVERNIGHT AS NORTHERLY FLOW USHERS IN SOME SLIGHTLY DRIER AIR. OVERNIGHT LOWS LAST NIGHT REACHED THE 20S IN MANY SPOTS WEST OF THE BLUE RIDGE.. AND SEE NO REASON WHY TEMPS WONT GET AS COOL TONIGHT. FREEZE WARNING ALREADY IN EFFECT FOR ZONES WEST OF THE BLUE RIDGE.. AND NO CHANGES NEEDED TO THAT. HAVE MADE A COUPLE OF MINOR ADJUSTMENTS TO LOWS TONIGHT EAST OF THE BLUE RIDGE.. BUT FORECAST OVERALL LOOKS PRETTY GOOD. WILL RAISE TEMPS A CATEGORY TOMORROW FOR AREAS NORTH AND WEST OF THE CITIES. TEMPS TODAY REACHED THE MID 60S IN MANY AREAS.. AND EVEN THOUGH HIGH IS BUILDING OVERHEAD TEMPS SHOULD STILL BE ABLE TO GET UP ABOVE 60. .LWX...FREEZE WARNING TONIGHT MDZ002>003-VAZ021-025>031-WVZ048>055 MARGRAF! md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 930 PM CST THU MAR 30 2000 LATEST SATELLITE IMAGERY TRENDS INDICATE A SLOWLY ERODING STRATUS DECK ACROSS MOST OF THE FORECAST AREA. LATEST RUC CONTINUES TO PROG WEAK PRESSURE ADVECTION AND DOWNGLIDE IN 290K TO 300K THETA LAYER AS RIDGING TAKES PLACE FROM 850MB TO 500MB. SEE NO REASON WHY STRATUS WOULD NOT CONTINUE TO DECREASE AND PLAN NO UPDATES AT THIS TIME. CLEARING SKIES WILL BRING TEMPS TO FORECAST LOWS. .JAN... MS...NONE. AR...NONE. LA...NONE. 43 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 925 PM EST THU MAR 30 2000 SAT PIX AND RADAR SHOW THE DIURNAL INFLUENCES WANING AS CLDS AND WDLY SCT -SHSN CONTINUE TO DSPT. (ACTUALLY PICKED UP 1/2 INCH ON THE HILL THIS AFTN/EVNG). ANOTHER S/WV WILL BE MOVG DOWN LATER TNGT BUT SAT PIX IMPLY THE CLDS ASSCD WITH THIS SYSTEM WILL BE CONFINED TO NRN ZONES...AND RUC RH PROGS ALSO IMPLY THIS. EVNG UPDATE WILL BE MORE OPTIMISTIC WITH THE CLD FCST. XPCT MAINLY CLEAR SKIES ACRS MOST OF NE PA TNGT...PARTLY CLOUDY SKIES ELSEWHERE. WILL KEEP IN THE CHC FOR A FLURRY OR TWO ACRS NYS WITH LOW CHC POPS CONFINED TO NRN ONEIDA. WILL NUDGE TEMPS DOWN A BIT AS THEY ARE NEAR FCST MINS ALREADY IN SEVERAL LOCATIONS...AND FEWER CLDS WILL ALLOW FOR SOME RADIATIONAL COOLING. THE FCST MAY ALSO BE A LTL PESSIMITIC FOR TMRW AS IT APPEARS MOST AREAS WILL SEE AT LEAST PARTLY SUNNY SKIES BY/DURING THE AFTN. WILL MAKE SOME ADJUSTMENTS TO BLEND BETTER WITH 1ST PD CHANGES. .BGM...NONE. BRADY ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1008 AM CST THU MAR 30 2000 CLOUDS LIKELY TO BE TROUBLESOME TODAY AS SOME AREAS ARE CLEARING OUT THIS MORNING WHILE CLOUDS ARE REDEVELOPING IN OTHERS. CURRENT TRENDS SUGGEST THAT CENTRAL AND SE ZONES WILL BE LEAST LIKELY TO SEE ANY SIGNIFICANT SUN, WHILE W AND N WILL SEE VARYING SKY CONDITIONS. WILL UPDATE TO INSERT VARIABLE CLOUDINESS W AND N, AND KEEP CENTRAL/SE MOSTLY CLOUDY FOR MOST OF THE AFTERNOON. CLOUDS OBVIOUSLY WILL HAVE SIGNIFICANT EFFECT ON AFTERNOON HIGH TEMPS IF THEY HOLD, BUT ONLY SHORT BREAKS WILL ALLOW SOME AREAS TO WARM TO CURRENT FORECAST HIGHS. WILL LOWER HIGHS SLIGHTLY IN CENTRAL/SE DUE TO MORE EXTENSIVE CLOUD COVER, BUT LEAVE TEMPS AS IS IN OTHER AREAS. WINDS WILL BE ADJUSTED TO DELAY ANY VEERING TO S OR SE, PER LATEST RUC/ETA. WE LIKELY WILL UPDATE AGAIN LATER TODAY IF AND WHEN CLOUD TRENDS BECOME MORE CLEAR. 24 .OUN... OK...NONE. TX...NONE. ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 903 PM EST THU MAR 30 2000 CONVECTION...MAINLY SHOWERS BUT WITH A FEW LIGHTNING STRIKES NOTED EARLIER...CONTINUES IN NORTH CAROLINA MOUNTAINS THIS EVENING...BUT HAVING A DIFFICULT TIME STAYING INTACT ONCE OUTSIDE INFLUENCE OF THE HIGHER TERRAIN. TRIGGERS INCLUDE A SLIGHT LOW LEVEL UPSLOPE COMPONENT PER KGSP 88-D...DEWPOINTS IN UPPER 40S AND LOWER 50S PER SURFACE ANALYSES...WEAK CONVECTIVE INSTABILITY PER 00Z GSO SOUNDING...AND WEAK DIFFERENTIAL POSITIVE VORTICITY ADVECTION PER 21Z RUC THAT MATCHES UP WELL WITH WATER VAPOR IMAGERY. DPVA PROGD TO SHIFT EASTWARD TOWARD CHARLOTTE AREA BY MIDNIGHT...AND RESULTANT SUBSIDENCE...NOT TO MENTION LACK OF HEATING...SHOULD SPELL THE END OF CONVECTIVE DEVELOPMENT. WILL KEEP AN EYE ON TRENDS AND MAY HAVE TO CONTINUE A SMALL POP IN SOME MOUNTAIN ZONES BUT WILL SEE WHAT THE SCOPE DISPLAYS AT ISSUANCE TIME. SOME MOUNTAIN AREAS HAVE SEEN UP TO ONE-QUARTER INCH OF RAIN THIS EVENING...AND WITH LIGHT WINDS AND EVENTUALLY CLEARING SKIES...WILL LIKELY SEE PATCHY DENSE FOG DEVELOP IN PREDAWN AND PLAN TO ADDRESS IN MOUNTAIN AND NORTHERN UPSTATE ZONES. OTHERWISE...TEMPERATURES SEEM ON TRACK AND WILL NOT MAKE ANY OTHER CHANGES. .GSP...NONE. BURRUS sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 951 AM EST THU MAR 30 2000 WATER VAPOR SHOWS WEAK SHORT WAVE MOVING ACROSS NORTH GA. DEEP MOISTURE ACROSS CENTRAL AND SOUTH GA. CURRENT RADAR SHOWS NUMEROUS SHOWERS ACROSS EAST CENTRAL GA MOVING EAST. SFC WARM FRONT ACROSS INLAND SOUTH COAST. BEST 850 MB WAA ACROSS EAST GA...SHIFTS EAST DURING AFTERNOON. CONVECTIVE PARAMETERS INDICATES AIRMASS MARGINALLY UNSTABLE THIS AFTERNOON WITH LIS AROUND -2. A FEW EMBEDDED TSTMS EXPECTED NEAR WARM FRONT. LOW LEVELS DRIER TO THE NORTH OF CAE...DEWPOINTS IN THE MID TO UPPER 40S NEAR CLT. RUCII SUGGEST BULK OF PRECIP WILL STAY MAINLY SOUTH OF CAE...EXPECT WARM FRONT WILL NOT MOVE MUCH FURTHER NORTH AS SFC LOW REMAINS WELL SOUTH OF REGION. SO...WILL LOWER POPS FROM CAE TO LANCASTER. CATEGORICAL AGS AREA. WILL LOWER TEMPS TO MID 60S AGS AREA. .CAE...NONE. AWP sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 247 PM CST THU MAR 30 2000 SURFACE LOW PRESSURE LOCATED OVER SOUTHEASTERN AL THIS AFTERNOON AS IT CONTINUES TO MOVE EASTWARD. KNQA 88D SHOWING A FEW LINGERING ECHOES...LIGHT RAIN...OVER NORTHWEST TN. WEAK VORT MAX HELPING TO CAUSE THIS LIGHT RAIN. LOW CLOUDS CONTINUE FROM TN TO OK WITH SOME BREAKS SHOWN BY SATELLITE AND SOME CLEARING NOTED FROM THE NORTH. SHORT RANGE MODELS IN CLOSE AGREEMENT THROUGH 12Z SATURDAY. FOR TONIGHT...ANY LINGERING LIGHT RAIN EXPECTED TO BE OUT OF THE CWFA BY 00Z AS LATEST RUC SHOWS VORT MAX WELL TO THE EAST. BASED ON MODEL CLOUD MACROS...CLOUDS FORECAST TO CONTINUE CLEARING FROM THE NORTH TONIGHT. WILL GO JUST SLIGHTLY BELOW FWC GUIDANCE FOR LOWS TONIGHT WITH TEMPERATURES NOT WARMING ALL THAT MUCH TODAY. FOR FRIDAY...RIDGING ALOFT WILL SPREAD OVER THE MIDSOUTH. LOTS MORE SUN WILL OCCUR HELPING BOOST TEMPERATURES TO NEAR FAN/FWC NUMBERS. FRIDAY NIGHT...MID AND HIGH LEVEL CLOUDS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST...BUT STILL DRY. WITH NORTHEAST LOW LEVEL WINDS CONTINUING TO FEED DRY AIR INTO THE AREA...THINK FWC TEMPERATURES MAY BE A LITTLE WARM. CONFIDENCE IN FORECAST SATURDAY AFTERNOON THROUGH SUNDAY IS LOW WITH MODEL DIFFERENCES. LATEST QPF GUIDANCE FROM HPC DOES NOT FORECAST ANY RAIN FOR OUR CWFA THROUGH SATURDAY...AND WILL GO ALONG WITH THIS THINKING. AVN MODEL SHOWS SHORT WAVE PASSING TO OUR SOUTH SATURDAY NIGHT. WILL MENTION CHANCE OF SHOWERS FOR SOUTHERN COUNTIES OF OUR CWFA ACROSS NORTH MS SATURDAY NIGHT. WILL INCLUDE CHANCE OF SHOWERS AND THUNDERSTORMS IN FORECAST FOR MONDAY AND TUESDAY WITH MOISTURE INCREASING AND APPROACH OF COLD FRONT FROM THE NORTHWEST. .MEM...NONE. tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1003 AM CST THU MAR 30 2000 SURFACE ANALYSIS AT MID-MORNING SHOWS LOW PRESSURE CENTERED OVER SOUTH AL. COOL NORTHEAST WIND FLOW IS OCCURRING ACROSS OUR CWFA. SATELLITE SHOWS WIDESPREAD LOW CLOUDS FROM THE MIDSOUTH EASTWARD TO OK. SOME BREAKS NOTED IN THE CLOUDS. KNQA 88D STILL INDICATING SPOTTING LIGHT RAIN FROM WEST TN INTO NORTHEAST AR. WILL NEED TO UPDATE ZONES THIS MORNING. LATEST RUC SHOWS WEAK VORT MAX MOVING ACROSS WEST TN THIS AFTERNOON. THEREFORE WILL PROBABLY KEEP IN SMALL CHANCE OF RAIN FOR MOST OF WEST TN THIS AFTERNOON. LOOKING AT 12Z ETA CLOUD MACROS...WILL WORD ALL AREAS AS MOSTLY CLOUDY THIS AFTERNOON. COULD BE SOME CLEARING ACROSS THE EXTREME NORTH...BUT THIS WILL BE LATE AFTERNOON. ALSO...WILL NEED TO LOWER HIGH TEMPERATURE FORECAST MOST AREAS FOR THIS AFTERNOON. .MEM...NONE. tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 949 AM CST THU MAR 30 2000 CLOUDY/MOSTLY CLOUDY SKIES COVERED ALL OF THE MID STATE AT MID MORNING. THERE WAS HOWEVER SOME DISSIPATION OF THE LOWER CLOUDS ...ESPECIALLY ACROSS NORTHERN MIDDLE AT THIS TIME. THE ANALYSES THIS MORNING SHOWED A WEAK UPPER LEVEL SHORTWAVE TO OUR W CAUSING SOME LIGHT SHOWERS OR SPRINKLES OVER W TN...BUT THEY WERE GRADUALLY WEAKENING/DISSIPATING AS THEY MOVED E. SURFACE LOW PRESSURE WAS LOCATED OVER SW AL PER 14Z SURFACE ANALYSIS WITH INVERTED TROUGH FROM THE LOW N INTO NE MS...WITH THE SYSTEM CONTINUING TO MOVE E TODAY. LATEST RUC/ETA SHOWS CLOUDS SHOULD REMAIN ALL DAY AS THE WEAK UPPER LEVEL SHORTWAVE WEAKENS AS IT MOVES GENERALLY E ACROSS THE FORECAST AREA THIS AFTERNOON. TEMP AT OUR OFFICE ALREADY 54 DEGREES WITH FORECAST OF 50 TO 55 TODAY. WILL UPDATE AT LEAST SOME OF THE ZONES TO INCREASE HIGH TEMPS FOR THIS AFTERNOON. MAY MENTION SPRINKLES POSSIBLE FOR PART OF AREA BUT WILL TAKE ANOTHER LOOK AT THIS BEFORE ZONE ISSUANCE. .BNA...NONE. STEIGERWALDT tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 853 PM EST THU MAR 30 2000 SFC PRESS GRADIENT ACRS FA TO BECOME MORE ANTI-CYCLONIC WITH TIME THRU FRI AS HI PRESS BUILDS IN FROM THE MIDWEST. UPR L/W TROF TO MOVE EAST OF THE FA BY LATER ON FRI. 21Z 40KM RUC SHOWS SFC TEMPS GETTING DOWN INTO THE U20S-M30S BY 09Z WITH LT WINDS OVRNITE. PLENTY OF LOW-LVL MOISTURE TO BE HANGING AROUND AS WELL WITH S/W SWINGING ON THRU EARLY FROM THE NW. RUC CRANKING OUT LT QPF MOSTLY IN THE MTNS OVRNITE. MICRO-PHYSICS INDICATE THAT THE PCPN WILL OCCUR AS SN IN THE HIR TRRN AND RA IN THE VLYS THRU 09Z. LOW-LVL LAPSE RATES TO REMAIN HI THRU 00Z SAT. H85 CAA TO OCCUR ACRS THE FA TONITE WITH WK WAA TO OCCUR ACRS NORTHERN NY DURING THE DAY ON FRI. 925 MB WET-BULBS TEMPS TO COOL OVRNITE AS WELL...SUPPORTING A CHANGEOVER TO SN. NW FLOW ALOFT AND PLENTY OF LOW-LVL MOISTURE TO PERSIST ACRS THE FA THRU 00Z SAT AS WELL. MOST OF THE DRYING THAT WILL OCCURRING DURING THE DAY ON FRI APPEARS TO BE OCCURRING AT MID- LVLS ONLY. BUFCAN SHOWS A COUPLE OF AREAS OF PCPN...CURRENTLY OVER ONT...STILL TO ROTATE THRU THE FA INTO EARLY ON FRI. IR SAT PIX SHOW ANY BREAKS IN THE LOW-LVL CLD COVER HAVE OCCURRED MOSTLY OVER THE SOUTHERN TIER ZONES THIS EVENING. HAVE LOWERED POPS IN THE ADIRONDACKS TO LIKELY OVRNITE BASED ON LACK OF ANY SIG (MEASURABLE) PCPN THERE SO FAR. HAVE CONTINUED SCT POPS IN MOST OTHER ZONES THRU THE OVRNITE PERIOD. BEST CHC FOR ANY MEASURABLE PCPN WILL BE IN THE NORTHERN MTNS OVRNITE. RAISED TEMPS A TAD OVRNITE IN MOST OF THE VLY ZONES BASED ON CURRENT TRENDS. NOT TOO CONVINCED OF ANY DRASTIC CLEARING TAKING PLACE IN THE NORTHERN ZONES ON FRI WITH LOW-LVL LAPSE RATES AND MOISTURE REMAINING SO HIGH...SO TRIED TO TREND TOWARDS EMPHASIZING MORE CLDS THERE. WORK ZONES AWAY. FINAL ZFP AFTER QUICK LOOK AT THE LATEST LAMP DATA. .BTV...NONE. MURRAY vt WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 835 PM MST THU MAR 30 2000 SNOW ADVISORY FOR SOUTHERN ZONES AND WIND ADVISORY FOR NORTHERN ZONES ARE SLOW TO MATERIALIZE THIS EVENING...BUT 00Z MODELS SUPPORT DEVELOPMENT LATE TONIGHT INTO FRIDAY MORNING. AS FOR WIND ADVISORY NORTH...00Z SFC ANALYSIS SHOWS TIGHT GRADIENT ALONG THE CONTINENTAL DIVIDE. 8PM SPOTTER REPORTS/RAWS TOWERS REPORT G30-35 MPH IN THE VICINITY OF STEAMBOAT-GREAT DIVIDE. SFC- 700MB GRADIENT TO TIGHTEN TONIGHT AFTER MIDNIGHT...NOT BY FURTHER COLD PUSH DOWN THE PLAINS BUT BY DEEPENING LOW PRESSURE NEAR ABQ. SO WILL REFRESH NPW FOR LATER WORDING. SNOW ADVISORY SOUTH...DURANGO HAS REPORTED RAIN AND 39 DEGREES. SPOTTER AND PATROL REPORT ONLY 1-2 INCHES ON WOLFCREEK PASS... PAGOSA SPRINGS AND MONTICELLO UTAH IN WARM SW OVERRUNNING FLOW. 00Z RUC AND ETA SHOW DISTURBANCE ROTATING UP INTO SOUTHERN ZONES. COLD FRONT SOMEWHERE IN NW NEW MEXICO SO COLD WEDGE WILL DEEPEN TONIGHT. ACCUMULATIONS LIKELY TO OCCUR MAINLY AFTER MIDNIGHT. SOME CONCERN THAT THE LA SAL/ABAJO MTNS COULD ACCUMULATE 5 INCHES...BUT WITH THAT ZONE JUST TO THE WEST OF SHEAR AXIS WILL LEAVE OUT OF ADVISORY. IN BETWEEN...THE CO CENTRAL MOUNTAINS ARE REPORTING EVENING SNOW AND THIS IS HANDLED ADEQUATELY IN THE CURRENT FORECAST. DEVELOPING EAST DOWNSLOPE FLOW SHOULD LIMIT ACCUMULATIONS AND WILL KEEP OUT OF ADVISORY. ALL-IN-ALL ANOTHER BEAUTIFUL NIGHT WEST OF THE DIVIDE. .GJT...WIND ADVISORY COZ004...005...013 AND UTZ023 SNOW ADVISORY COZ018...019...022...023. RAMEY co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 225 PM EST THU MAR 30 2000 WILL KEEP THIS DISCUSSION BRIEF DUE TO TORNADO WATCH #197. MESOLOW OVER FAR SW GA CURRENTLY MOVING E...WITH PRE-FRONTAL TROUGH EXTENDING SW THROUGH AQQ. STORM IN FAVORABLE POSITION E OF MESOLOW CURRENTLY MOVING E. WATER VAPOR IMAGES CURRENTLY SHOW AN UPPER JET STREAK CROSSING OUR CWA AND ESCORTING THIS WAVE OF PCPN EWD. HEAVY RAIN CONTINUES TO BE A CONCERN OVER OUR NE ZONES WHERE NEARLY STNRY FRONT EXISTS WITH STRONG N-S THERMAL GRADIENT. COLD FRONT STILL EXTENDS SW FROM MESOLOW NEAR MOB. 16Z RUC ADVERTISES THIS FEATURE TO REACH OUR ERN ZONES AROUND OR SHORTLY AFTER 03Z. CURRENT ZONES DO A CONSISTENT JOB WITH ENDING PCPN FROM W-E TNGT FOR MOST AREAS. BELIEVE ANOTHER ROUND OF PCPN WILL BE POSSIBLE EARLY TNGT WHEN COLD FRONT SW OF MOB PASSES E THROUGH OUR ZONES. WILL KEEP LEFTOVER POPS TNGT FOR ALL ZONES WITH PERHAPS RESIDUAL POPS THE FIRST PART OF FRI FOR EXTREME ERN ZONES. FWC HAS BEEN DOING A VERY POOR JOB WITH BOTH MAXIMUM TEMPERATURES AND POPS LATELY...SO WILL GO NEAR OR SLIGHTLY BELOW PERSISTENCE WITH CURRENT ZONE PACKAGE ON TEMPERATURES. FIRE WEATHER - WET GROUND IN THE AREA AND HIGH DEWPOINTS UPSTREAM SHOULD PRECLUDE A THREAT FOR LOW RH VALUES THROUGH FRIDAY. MARINE - WILL KEEP WINDS DOWN TO SCEC LEVELS AS BROAD SURFACE LOW TRACKS E JUST N OF WATERS. EXTENDED - LOOKS UNSETTLED...BUT WILL NOT MAKE SIGNIFICANT CHANGES NOW IN THE INTEREST OF TIME. FEEDBACK IS WELCOME. PRELIMINARY NUMBERS... TLH EB 063/077 053/079 4200 PFN EB 068/076 056/077 3000 DHN EB 063/077 053/079 3000 ABY EB 059/075 053/077 5300 VLD EB 064/079 057/080 4200 .TLH... AL...NONE GA...NONE. FL...NONE. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 300 AM CST FRI MAR 31 2000 FORECAST CHALLENGES -- PRECIPITATION CHANCES TONIGHT THROUGH SATURDAY SYNOPSIS -- LATEST WATER VAPOR CHANNEL IMAGERY SHOWED A SPLIT FLOW PATTERN OVER THE WRN HALF OF U.S. WITH A PROGRESSIVE TROUGH LOCATED OVER ND AND A RETROGRESSIVE...DIGGING CLOSED CIRCULATION OVER NRN AZ. THE REGIONAL RADAR MOSAIC SHOWED A BAND OF HIGHER REFLECTIVITIES FROM SWRN NEB TO SERN SD IN AN AREA OF 500-300MB Q-VECTOR CONVERGENCE PER RUC AND MESOETA 0-HR FORECAST. MEANWHILE...07Z MANUAL AND MSAS SURFACE ANALYSES SHOWED A WEAK FRONT EXTENDING FROM CNTRL MN SWWD THRU ERN NEB INTO NWRN KS. FORECAST -- ALL SHORT RANGE MODELS ARE FAIRLY CONSISTENT IN MAINTAINING A MEAN TROUGH POSITION OVER THE NRN PLAINS THROUGH THE FORECAST...WITH SLIGHT DIFFERENCES ON THE TIMING AND THE AMOUNT OF QPF GENERATED OVER THE AREA. IN THE SHORT TERM...THE BAND OF LIGHT SHOWERS FROM SWRN TO N CNTRL NEB ARE THE MAIN FORECAST CONCERN. 06Z/31 RUNS OF THE RUC AND MESOETA SHIFT THE AREA OF 500-300MB Q-VECTOR CONVERGENCE OVER THE NWRN ZONES THIS MORNING WITH THE MESOETA GENERATING SOME LIGHT QPF THERE. 08Z LAPS SOUNDING FOR THE OFK AREA SHOWS A CONSIDERABLE AMOUNT OF DRY AIR BELOW 650MB...SO WE WILL ONLY MENTION SOME SPRINKLES THROUGH THE MORNING OFK WWD. OTHERWISE... TEMPERATURES WILL BE THE MAIN CONCERN. IR IMAGERY CONTINUES TO SHOW AN EXPANSIVE CIRRUS CANOPY OVER CO AND WRN KS...ADVECTING NEWD IN THE MEAN FLOW. THUS...MID AND HIGH LEVEL CLOUDS SHOULD CONTINUE TO THICKEN DURING THE DAY WITH LITTLE INSOLATION EXPECTED. CURRENT TEMPERATURES REMAIN MILD...IN THE MID 30S TO LOWER 40S...SO MOS HIGHS LOOK REASONABLE. BY LATE THIS AFTERNOON/EARLY EVENING ALL SHORT RANGE MODELS INTENSIFY A SHORT JET SEGMENT AT 300MB OVER ERN NEB/IA WITH INCREASING DIVERGENCE IN THE RIGHT REAR QUADRANT OF THIS FEATURE OVER THE SRN CWFA. ISENTROPIC ASCENT INTO THIS DIVERGENT REGION ALOFT APPEARS TO BE THE MAIN FORCING FOR THE RESULTANT QPF OUTPUT BY THE MODELS OVERNIGHT AS Q-VECTOR FIELDS SHOW NO STRONG SIGNAL. LOW-LEVEL MOISTURE WILL REMAIN VERY LIMITED IN THIS REGION...SO AMOUNTS SHOULD BE LIGHT. FORECAST SOUNDINGS AND CRITICAL THICKNESS FORECASTS INDICATE THAT ANY PRECIPITATION THAT FALLS SHOULD BE LIQUID. HOWEVER...THE AMOUNT OF DRY AIR IN THE LOW LEVELS MAY ALLOW FOR ENOUGH EVAPORATIVE COOLING FOR A MIX. ATTM...WE WILL ONLY MENTION LIGHT RAIN AND LET THE DAY SHIFT EVALUATE THE SITUATION FURTHER. TEMPERATURES SHOULD REMAIN AT OR SLIGHTLY ABOVE GUIDANCE MINS. ON SATURDAY...THE AVN ADVERTISES ANOTHER JET SEGMENT TRANSLATING ACROSS THE AREA DURING THE DAY WITH AN AREA OF ENHANCED DIVERGENCE OVER THE SRN ZONES. WE WILL MAINTAIN CHANCE POPS ACROSS THE FAR S WHERE THE BEST LIFT IS FORECAST TO OCCUR. WIDESPREAD CLOUDS AGAIN WILL LIMIT INSOLATION WITH DAYTIME HIGHS AT OR SLIGHTLY BELOW GUIDANCE. IN THE EXTENDED...THE NEW RUNS OF THE AVN AND MRF INDICATE SLIGHTLY COOLER TEMPERATURES ON SUNDAY AND MONDAY IN ASSOCIATION WITH A STRONG COLD FRONT THAT WILL DIVE S THROUGH THE PLAINS. THUS...WE WILL MAKE SOME CHANGES TO THE HIGH TEMPERATURE FORECAST IN ALL ZONES. .OMA...NONE. MEAD ne TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 340 AM CST FRI MAR 31 2000 INITIAL AREA OF LIGHT RAIN LIFTING N INTO KS THIS MORNING. THIS PRECIP TIED CLOSELY TO UPPER LEVEL DIVERGENCE BETWEEN JETS LIFTING ACROSS NM AND N TX. ADDITIONAL SCT CONVECTION BEGINNING TO DEVELOP ACROSS ERN NM WHERE LAPSE RATES REMAIN STEEP. THIS EXPECTED TO WEAKEN AS IT MOVES N INTO MORE STABLE AIR ACROSS SE CO. OTHER FEATURE OF INTEREST IS BARRIER JET WHICH HAS DRIVEN CDFNT INTO NRN NM. BOUNDARY REMAINS HELD UP W OF FA INTO NW KS WITH SN BEING REPORTED ACROSS MUCH OF CO. WILL KEEP PRECIP LIQUID TODAY WITH MUCH MORE UNCERTAINTY AND CONCERN OVERNIGHT TONIGHT FOR NW ZNS. PRECIP YET TO DEVELOP AS 06Z RUC SUGGESTED ACROSS REST OF W TX. FEEL HOWEVER THIS WILL OCCUR LATER THIS MORNING AS NEXT BIT OF JET ENERGY LIFTS OUT OF NRN MEXICO TO SPREAD UVM OVER TOP MOIST UPSLOPE FLOW. PRECIP SHIELD SHOULD SPREAD N AND E ACROSS FA DURING DAY. WILL LIKELY GO WITH CATEGORICAL PRECIP FIRST PERIOD ALL ZNS EXCEPT SE WHERE THEY ARE MORE REMOVED FM DYNAMICS. MAY ACTUALLY HAVE PROLONGED BREAK IN PRECIP SW ZNS THIS AFTN THOUGH TIMING UNCERTAIN AS NEXT SHRTWV PROGD TO COME OUT OF BASE OF DEEPENING SW U.S. TROUGH BY EARLY EVE. WITH STRONG UPSLOPE AND PRECIP OFF AND ON DON/T ANTICIPATE MUCH DIURNAL CHANGE IN TEMPS CENTRAL AND WRN ZNS. WILL CONTINUE CATEGORICAL POPS OVERNIGHT AS NEXT PIECE OF ENERGY IS EJECTED OUT OF DIGGING LOW OVER SRN AZ. THINK AXIS OF HEAVIEST PRECIP WILL OCCUR ACROSS SRN ZNS AS UPSLOPE WEAKENS FURTHER N DUE TO BACKING SFC WINDS AND H8 FNT SETTLING FURTHER S. AM CONCERNED WITH ACCUMULATING SN ACROSS PORTIONS OF NW ZNS OVERNIGHT. DEEPENING COLD DOME SLIDING ALONG LEE OF ROCKIES COULD SWITCH PRECIP AFT SUNSET. H8-H7 THCKNS DROP THROUGH THE NIGHT. AMOUNTS COULD EASILY REACH ADVSY CRITERIA BUT AM STILL TOO UNCERTAIN ABOUT LONGEVITY OF DYNAMICS TO ISSUE WATCH FOR HEAVY SN. PRECIP LIKELY TO LINGER INTO SAT ESP SRN HALF FA. WILL KEEP HIGH POPS GOING S AND TAPER BACK TO CHC N. DIURNAL TEMP SWING SHOULD AGAIN BE TEMPERED BY PLENTY OF CLOUDS. IN EXTENDED...UPPER LOW EXPECTED TO CONTINUE MOVING S TO NRN BAJA BY SAT EVE. DOMINATING NRN STREAM DYNAMICS THEN BEGIN TO SHOW UP IN NRN PLAINS AND WILL BE RESPONSIBLE FOR CANADIAN AIRMASS DIPPING INTO CO/NE SUN. INITIAL SFC HIGH CENTER SETTLING ACROSS FA ON SUN HOWEVER ENOUGH INSTABILITY STILL IN PLACE TO CONTINUE SLIGHT MENTION OF PRECIP. CANADIAN FROPA LATE SUN/EARLY MON TO DROP TEMPS BACK SOME FOR BEGINNING OF NEXT WORK WEEK. .AMA... TX...NONE. OK...NONE. COBB tx SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO 345 AM MST FRI MAR 31 2000 ...SNOWFALL AMOUNTS CHALLENGE OF THE DAY... ONE OF THOSE DAYS WHEN YOU CAN USE THE MODELS FOR GENERAL ORIENTATION BUT MUST RELY ON SHORT-TERM TRENDS FOR THE DETAILS. SO FAR...WARNINGS/ADVISORIES...APPEAR TO BE WORKING OUT NICELY. SEE PUEBLO LOCAL STORM REPORTS (DENLSRPUB) FOR DETAILS ON SNOWFALL ACCUMULATIONS SO FAR. MAIN ISSUE TO RESOLVE THIS MORNING...WHETHER OR NOT TO EXPAND/DISCONTINUE WARNINGS/ADVISORIES ANYWHERE. EARLY THIS MORNING...THE ONLY MODEL TO HAVE ANY KIND OF A HANDLE ON THE TRUE SURFACE WINDS ACROSS THE PLAINS IS THE RUC...INDICATING NORTHERLY SURFACE WINDS ALONG THE FRONT RANGE...IN THE COLD AIR DAMMING WEDGE...THAT SHOT SOUTH ALONG THE FRONT RANGE INTO PUEBLO COUNTY LATE THURSDAY AFTERNOON. THIS IS THE WEDGE OF COLDER/DRYER CP AIR THAT TURNED THE PRECIP INTO SNOW ALONG THE SOUTHERN COLORADO FRONT RANGE I-25 CORRIDOR LATE THURSDAY/THURSDAY EVENING. THE OTHER MODELS SAY THE SURFACE WINDS SHOULD BE OUT OF THE EAST TO NORTHEAST RIGHT NOW...AND THEY ARE INCORRECT. WILL TRY TO EXTRAPOLATE THE SHORT TERM FORECAST BASED ON CURRENT RUC/SATELLITE/RADAR TRENDS. APPEARS THAT UPPER LOW CENTER IS PRESENTLY SITUATED OVER NORTHWEST ARIZONA AND TRACKING SOUTH. UPPER LOW IS EJECTING POTENT...QUICK MOVING SHORTWAVES INTO SOUTH CENTRAL/SOUTHEAST COLORADO. AT THE PRESENT TIME...EACH LOBE THAT EJECTS NORTHEAST HAS SOME PRETTY GOOD LIFT ASSOICATED WITH IT...AND IS CONVECTIVE IN NATURE BASED ON SATELLITE/LIGHTNING DATA. BEING IN THE DIFFLUENT (AND APPARENTLY DIVERGENT) NORTHEAST QUADRANT OF THE LOW...EACH BAND OF CLOUDS/ PRECIPITATION THAT ROTATES OUR WAY BLOSSOMS NICELY...WITH NICE EXPANDING/COOLING OF CLOUD TOPS NOTED IN SATELLITE IMAGERY. RECENT SATELLITE PICTURES INDICATE MORE EXPANDING/COOLING TOPS DEVELOPING OVER CENTRAL NEW MEXICO...HEADED FOR SOUTHERN COLORADO. AS THE UPPER LOW DROPS SOUTH THROUGH WESTERN ARIZONA WITH TIME...NOT CERTAIN HOW LONG THE SHORTWAVES MOVING INTO SOUTHERN COLORADO WILL REMAIN POTENT...BUT FOR NOW WILL RIDE THE WAVE...AND PLAY CURRENT TRENDS. THIS MEANS THAT THE COMBINATION OF UPPER LEVEL LIFT (MAINLY WAA) ASSOCIATED WITH THE SHORTWAVES AND LOW/MID LEVEL UPSLOPE (CAA) ASSOCIATED WITH THE LOW/MID LEVEL FRONT WILL KEEP US WITH PERIODS OF SNOW (SOME RAIN OVER THE LOWEST REACHES OF THE LOWER ARKANSAS VALLEY) THROUGH TODAY. SEE NO REASON TO DISCONTINUE ANY OF THE PRESENT WARNINGS/ADVISORIES EXCEPT POSSIBLY FOR 58/59...AS HAVEN'T SEEN ANYTHING SIGNIFICANT AT LXV YET. WILL LEAVE IT ALONE THOUGH AS FAIRLY CERTAIN SOME OF THE EASTERN SLOPES OF THE SAWATCH RANGE MAY BE GETTING HIT AND WE JUST DON'T KNOW IT YET. ELSEWHERE...SALIDA DCP HAS INDICATED .30 INCHES OF LIQUID SINCE ABOUT 1Z SO LOOKS GOOD FOR 68/69. ALL OTHER AREAS...WE HAVE RECEIVED REPORTS OF AT LEAST A FEW INCHES OF SNOW BUT IN MOST CASES SEVERAL INCHES. WILL EXPAND WINTER STORM WARNING TO COVER THE SAN LUIS VALLEY FOR TODAY...AS WE HAVE ALREADY HAD REPORTS OF 4 TO 6 INCHES REPORTED FROM ALS AND CENTER, RESPECTIVELY. STILL SNOWING THERE ACCORDING TO ALS ASOS. NOT SURE IF BRUNT HAS ALREADY PASSED OR NOT. BUT BASED ON SATELLITE SHOULD BE SOME ADDITIONAL ACTIVITY SPREADING INTO THE VALLEY YET THIS MORNING. WILL ALSO UPGRADE ADVISORY FOR 60/61 TO A WARNING BASED ON SATELLITE AND FOR CONSISTENCY. ACROSS THE PLAINS...MAIN CHANGE FROM PREVIOUS FORECAST WILL BE TO CHANGE PRECIPITATION TO MOSTLY SNOW...EXCEPT FOR SOME OF THE LOWER REACHES OF THE ARKANSAS VALLEY...WHERE ELEVATION/HIGHER DEWPOINTS MAY KEEP SOME RAIN AROUND. WILL ALSO ADD SOME LIGHT ACCUMULATIONS TO MOST PLAINS LOCATIONS BUT NOT GO HOG WILD AS SNOW SHOULD STAY PRETTY WET AND HAVE TROUBLE ACCUMULATING. STILL...AN INCH OR TWO (MAINLY ON GRASSY AREAS AND GENERALLY NOT ON ROADS) CERTAINLY WITHIN REASON. TONIGHT...LOOKS LIKE WE COULD STILL BE SEEING SOME WIDESPREAD SNOW AROUND THE REGION...ALTHOUGH SHOULD BE OF THE LIGHTER TYPE...AS H7 TEMPS COOL AND ABSOLUTE HUMIDITIES DECREASE. AT THE SAME TIMEE...SNOWFALL WILL LIKELY BECOME OF THE LIGHTER/FLUFFIER NATURE AND MAY ACCUMULATE BETTER WITH THE COOLER TEMPERATURES. WILL KEEP HIGH POPS IN THE FORECAST FOR TONIGHT MOST AREAS. WILL BEGIN TO DECREASE ACTIVITY ALL AREAS LATE TONIGHT/SATURDAY AS EVERYTHING BEGINS TO PULL SOUTH AND DRYER AIR ENCROACHES FROM THE NORTH. NO TIME FOR EXTENDED REVIEW THIS MORNING. WILL LEAVE AS IS. .PUB...WINTER STORM WARNING 60/61/62/63/64/65/66/67/70/74/75 TODAY SNOW ADVISORY 58/59/68/69/72 TODAY co EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 930 AM EST FRI MAR 31 2000 CURRENTLY...ERSTWHILE Q-STATIONARY BOUNDARY NOW STARTING TO MAKE STEADY SOUTHWARD PROGRESS. AS OF 14Z IT WAS ALONG A TTS-KSM-TPA LINE. DEW POINTS L70S SOUTH OF THE BOUNDARY...AND EARLY VISIBLE SATELLITE PICS SHOW ENOUGH BREAKS IN THE CLOUDS TO ALLOW FOR DECENT HEATING. 12Z RAOBS SHOW MOISTURE POOLED INVOF THE BOUNDARY TO THE TUNE OF ABOUT 1.4" TO 1.5" OF PWAT. HENCE...THE AIR MASS OVER THE SOUTHERN COUNTIES SHOULD GET SUFFICIENTLY UNSTABLE TO ALLOW SOME CONVECTION TO REFIRE ALONG/SOUTH OF BOUNDARY. WHATEVER UPPER SUPPORT THERE WAS OVERNIGHT NOW APPEARS TO BE MOVING OFFSHORE PER THE LATEST RUC SHOWING A WEAK MID LEVEL RIPPLE NOW EAST OF THE STATE...AND WEAK TO NIL TO H25 JET DYNAMICS. NEVERTHELESS... BOUNDARY IS STILL MAINTAINING ITSELF...LIKELY A FUNCTION OF SURFACE CONVERGENCE...SO WILL NEED TO ADJUST POPS UPWARD OVER THE SOUTHERN COUNTIES. NORTH OF THE BOUNDARY...CLOUDS AND ADVECTION OF DRIER AIR SOUTHWARD FROM NORTH FLORIDA WILL INHIBIT RAIN CHANCES...AND WILL LOWER THERE. WILL ALSO LOWER TEMPS AS AFOREMENTIONED CLOUDS SHOULD BE TOUGH TO DISLODGE...WITH LOW LEVEL FLOW VEERING TO N-NE OFF THE ATLC. MARINE...WIND SHIFT NOW APPEARS TO BE ALMOST ALL THE WAY THROUGH THE FLG-COF LEG AND WILL CONTINUE ADVANCING SLOWLY SOUTHWARD. WILL LIKELY NEED TO SLACKEN THE WIND SPEEDS IN THE COF-JUP LEG WITH THE BOUNDARY SITTING OVER THAT AREA MOST OF THE DAY. .MLB...NONE. AVIATION/FIRE WX...CRISTALDI PUBLIC/MARINE...WIMMER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 930 AM EST FRI MAR 31 2000 NO SIGNIFICANT CHANGES PLANNED IN UPDATES. VISIBLE SATELLITE AND METARS SHOW LOW CLOUDS AND FOG GRADUALLY DISSIPATING OVER THE CWA. WILL REMOVE MENTION OF THESE FEATURES IN ZONE UPDATES. 12Z SOUNDINGS SUGGEST THAT FORECAST HIGHS ARE REASONABLE. WILL TWEAK WIND DIRECTIONS AND SPEED IN COASTAL WATERS FORECAST BASED ON BUOY DATA AND 13Z RUC OUTPUT...WHICH SHOWS FLOW OVER THE WATER RAPIDLY VEERING TO THE E BY LATE THIS AFTERNOON. ADEQUATE SURFACE MOISTURE THIS AFTERNOON SHOULD PRECLUDE FIRE WEATHER THREAT AND SHOULD RESULT IN SCATTERED AFTERNOON CONVECTIVE CLOUDS...IN AGREEMENT WITH TAFS. INPUT IS ALWAYS WELCOME. .TLH... AL...NONE GA...NONE. FL...NONE. TJT fl AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 1030 AM CST FRI MAR 31 2000 SFC LOW AND ASSOCIATED UPPER DYNAMICS CONT TO PULL SLOWLY NE OUT OF NERN ND. LATEST RUC SHOWS A TROF ROTATING SOUTH ON THE BACKSIDE OF THE SFC LOW. THIS FEATURE WILL HELP TO REINFORCE CAA ACROSS AREA. TEMPS FOR TODAY...ESPECIALLY ACROSS THE NRN TIER COUNTIES...MAY HAVE TO BE DROPPED AT LEAST 5 DEGREES...AND PROBABLY CLOSER TO 10 DEGREES. ANOTHER CONCERN IS CLOUD SHIELD. LATEST RUC AND MESO-ETA SHOW THAT 850-700MB 70% LINE MATCHES UP WELL WITH EDGE OF CLOUD SHIELD. BOTH MODELS BRING THIS 70-80% RH INTO THE NRN TIER COUNTIES...AND DOESN'T MOVE IT OUT UNTIL ALMOST 00Z TONIGHT. WILL HAVE TO TWEAK ZONE GROUPINGS AND PLAY WITH CLOUD COVER...WHICH WILL ALSO HAVE AN EFFECT ON THE TEMPERATURES. LASTLY...WITH REINFORCING TROF MOVING THROUGH...SFC GRADIENT DOESN'T REALLY RELAX UNTIL LATER THIS AFTERNOON. WILL HAVE TO UP WINDS AND ADD BREEZY MOST ALL AREAS. .ABR...NONE. HINTZ sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1015 AM CST FRI MAR 31 2000 APPEARS ANOTHER WELL MIXED DAY IN STORE FOR CWA IN MIDST OF LOW LVL CAA AND WLY COMPONENT TO FLOW. SECONDARY CDFNT THRU NWRN 3RD OF SD. FOR NOW...MID/HI CLDS OVR SERN HALF OF CWA ARE CONTINUING TO PULL AWAY...BUT WL SEE CI CLAIMING GROUND ACRS SRN HALF OF REGION THRU AFTN. ALSO...RAOBS AND FCST RUC SOUNDING INDICATE SOME POTENTIAL FOR SC FORMATION THRU AFTN...ESPLY N WHERE FLOW IS MOST CYCLONIC... AND COLDEST ALFT. EVEN WITH INCREASED SUNSHINE N...RAOBS SUGGEST THAT TEMPERATURE POTENTIAL BY MIXING SHOULD ONLY REACH MID TO UPPER 50S MOST AREAS...MAYBE LWR 60S FAR S. WNDS MAY BE A TAD ON THE LOW SIDE ACRS N AS WELL. WL MAINLY CLEAN UP TO TAKE OUT MENTION OF SPRINKLES OR LIGHT SHOWERS IN SERN PTN OF CWA...AND BE MORE OPTIMISTIC ON SUNSHINE MOST AREAS. .FSD...NONE CHAPMAN sd TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE AMARILLO TX 600 AM CST FRI MAR 31 2000 RAPID SHRA/TSRA DEVELOPMENT ACROSS S PLAINS INTO ERN TX PNHDL ATTM. UPDATED ZNS TO TAKE MENTION OF AFTN OUT OF NE ZN GROUPING. ALSO...TEMP AT KCAO DROPPED ANOTHER COUPLE DEGREES WITH ASOS NOW REPORTING SN. MESONET DATA STILL SHOWING E WINDS AT BOISE CITY HOWEVER KENTON HAS BACKED TO NE. LATEST WINTER COMPOSITE FM 09Z RUC INDICATES SNOW CHCS INCREASING THROUGH 18Z ACROSS CIMARRON/DALLAM COUNTIES. WILL CONTINUE TO MONITOR THAT AREA CLOSELY FOR CHANGE TO SNOW AND POSSIBLE ADVISORY. .AMA... TX...NONE. OK...NONE. COBB tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 250 PM CST FRI MAR 31 2000 FORECAST QUANDARIES...PCPN AMOUNTS AFTER 06Z SUN...TEMPERATURES. CURRENT ASOS/AWOS OBSERVATIONS...SATELLITE IMAGERY...AND LAPS/SURFACE ANALYSES SHOWING SURFACE RIDGING INFLUENCES CENTERED ACROSS S IL...RESULTING IN MOSTLY SUNNY SKIES...NORTHERNLY SURFACE WINDS...AND DEWPOINTS RANGING MID 30S TO MID 40S. UPPER AIR RUC/CHART ANALYSES ILLUSTRATING RIDGING INFLUENCES ALSO ALOFT. 18Z RUC INITIALIZING A 100KT+ JET OVER CENTRAL AL AND MS. 12Z FRI REGIONAL MODEL INITIALIZATIONS AND PROGGED EVOLUTION THROUGH 00Z MON SIMILAR. MODELS MOVING CURRENT HIGH PRESSURE SYSTEM EAST AND EXPECT IT TO APPROACH THE MID ATLANTIC COAST BY 18Z SAT. THIS WILL RESULT IN INCREASED CLOUDINESS DURING THE DAY ON SAT AS SOUTHERLY SURFACE FLOW ADVECTS MOISTURE INTO REGION. UPPER LEVEL FLOW WILL BRING IN ADDITIONAL MID AND UPPER LEVEL MOISTURE ACROSS REGION AS FLOW DEVELOPS A MORE SW FETCH ASSOCIATED WITH DEEPENING UPPER LEVEL LOW/TROUGH ACROSS THE W U.S. IN AGREEMENT WITH LATEST MODEL DIAGNOSTIC DISCUSSION THAT ETA/AVN SOLUTIONS HAVE A BETTER HANDLE ON LOW PRESSURE SYSTEM DEVELOPMENT ACROSS LOWER MS VALLEY REGION BY 06Z SUN. THESE TWO MODELS BRING FRONTAL SYSTEM ACROSS AREA BY 12Z SUN AND DEVELOP A STRONG LOW PRESSURE SYSTEM ACROSS THE UPPER MS VALLEY BY 00Z MON. PCPN POPS EXPECTED "TO REACH" CATEGORICAL STATUS DURING THE DAY ON SUNDAY AS BEST ATMOSPHERIC DYNAMICS WILL BE IN PLACE. RAINFALL COULD POSSIBLY BE HEAVY AT TIMES. THERE IS SOME DISAGREEMENT WITH BOTH THE ETA/AVN PROGGING IN EXCESS OF ONE INCH BETWEEN 06Z AND 12Z SUN ACROSS REGION WITH 6 ORLY ONE INCH PRECIPITATION AMOUNTS OVER SOUTHERN CWA AT 18Z SUN AND 00Z MON. HOWEVER...DAY TWO QPF VALUES SHOWING MORE IN LINE WITH THE NGM SOLUTION. EVENTHOUGH THIS IS AN OVER-RUNNING RAINFALL EVENT...ATMOSPHERIC INSTABILITY MAY BE ENOUGH TO SUPPORT SOME ITS DEVELOPMENT DUE TO PRONOUNCED INSTABILITY ADVECTION AND 850MB PROGRESSIVE JET DYNAMICS. TEMPERATURES...WILL COMPROMISE BETWEEN AVN FAN/NGM MOS VALUES TONIGHT FOR LOWS. DESPITE SOUTHERLY WIND FLOW DEVELOPMENT ON SAT...BELIEVE INCREASED CLOUDINESS WILL INHIBIT TEMPERATURES FROM REACHING AVN FAN HIGHS. WILL TREND TOWARD NGM MOS/ETA IN HOUSE BOUNDARY TEMPERATURE SCHEME VALUES FOR SAT HIGHS. WILL GO WITH AVN FAN/NGM MOS LOW VALUES FOR SAT NIGHT. AGAIN QUESTION AVN FAN HIGHS ON SUNDAY. WILL TREND TOWARD THE MORE CONSERVATIVE NGM MOS VALUES HERE. PRELIMINARY NUMBERS FOR COORDINATION PURPOSES ONLY... BNA 045/071/056/068 0188 CSV 040/068/052/063 0078 .BNA...NONE. 14 JBW tn