AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1021 AM EST WED JAN 26 2000 LK EFFECT SNOW WRNG CONT FOR BERRIEN...LAPORTE AND STARKE TDA. THE MID-LAKE BAND HAS RETREATED WEST THIS AM AS OFF-SHORE LAND BREEZE FOCUSED CONVERGENCE FARTHER WESTWARD. UPSTREAM OBS SHOW WINDS BACKING TO A MORE NWLY DIRECTION AND SO EXPECTING THE BAND TO MOVE EWD BTWN NOW AND EARLY THIS AFTN. ALSO THE MODE SHOULD BECOME MORE MULIT-STRUCTURED GIVEN THE DECREASE IN THE CONVERGENCE. THE 06Z ETA AND THE CURRENT RUC2 ARE NOT SHOWING THE WINDS BACKING SO DON'T BELIEVE THEY HAVE A VERY GOOD HANDLE ON THE SITUATION. AS THE WINDS BACK AND THE SINGLE BAND TRANSITIONS...EXPECT LESSER ACCUMULATIONS COMPARED TO THE SINGLE BAND PARKED OVER THE FAVORED AREAS. ALSO AN H8 THERMAL TROF EAST-WEST IN CTL LWR MI WL SAG SOUTH TODAY BRINGING AN INCREASE IN THE DELTA T VALUES. ALL SAID... THE AREAS IN THE WARNING COULD STILL PICK UP 2 TO 4 INCHES SO WITH RATES OF UP TO 1 INCHE PER HOUR...WL CONT THE WARNING THROUGH THE REST OF TODAY. TEMPS LOOK ON TRACK SO NO CHGS OTHER THAN SNOW AMTS IN THE WARNING (DECREASING SLIGHTLY FROM 2 TO 5 DOWN TO 2 TO 4). .IWX...LK EFFECT SNOW WRNG TDA...MIZ077..INZ003...INZ012 JLA in SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 900 PM MST WED JAN 26 2000 ...UPDATES PLANNED FOR ZONES AND STATE... SATELLITE IMAGERY INDICATED A STRONG VORTICITY CENTER NEAR MSO AT 00Z. NGM/ETA 12HR FORECASTS FROM 12Z RUNS AND LATEST INITIALIZATIONS TEND TO BE TOO FAR W THROUGH S WITH FEATURE. SNOW...AND LOCALLY HEAVY SNOW...OVER THE SW HAS DIMINISHED SO WILL BE DROPPING POPS. BUT STILL PLAN TO LEAVE THEM IN LIKELY CATEGORY AS AIRMASS IS FORECAST TO CONTINUE MOIST AND UPSLOPE FLOW IS FORECAST TO INCREASE. FARTHER N BASED ON 12Z MODEL RUNS UPDATED CENTRAL SECTIONS FOR HIGHER POPS TONIGHT INTO THU. SATELLITE IMAGERY INDICATED A VORTICITY CENTER OVER SW SASK AT 00Z WHICH WAS DRIFTING N. AGAIN NGM/ETA ARE HAVING TROUBLE HANDLING THE FEATURE. LATEST ETA RUN DOES HAVE UPPER LOW IN THE VICINITY OF THE CENTER. HIGHER LEVEL MOISTURE IS MOVING S TOWARDS CENTRAL MT BASED ON WATER VAPOR IMAGERY AND ETA AND NGM DO INCREASE UPSLOPE FLOW ABOVE THE LOW LEVEL. LATEST NGM/ETA DO NOT FORECAST MUCH IN THE WAY OF SHORTWAVE ENERGY TO MOVE S THROUGH N CENTRAL MT BUT LATEST RUC DOES. LATEST ETA KEEPS PLAINS BASICALLY DRY WHEREAS BEFORE IT WAS WET. LATEST RUC IS ALSO DRY BUT IT DOES NOT HANDLE THE LIGHT SNOW WHICH WAS REPORTED AT YQL EARLIER AND CTB AT 03Z. HAVE DECIDED TO HANG ON TO HIGHER POPS BUT ACCUMULATIONS MAY NOT BE THAT GREAT. WILL ADJUST A FEW TEMPERATURES UPWARD IN THE N DUE TO HIGHER DEWPOINTS AND EXPECTED CLOUDINESS. WILL ALSO DROP DLN A FEW DEGREES AS THEY ARE ALREADY AT THEIR FORECAST LOW. BLANK GTF 6611 HLN 4311 HVR 3321 mt SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 812 PM CST WED JAN 26 2000 KUEX 88D SHOWING A CONTINUOUSLY REDEVELOPING AREA OF SNOW STRETCHING ACROSS BUFFALO AND KEARNEY COUNTIES...AS OF 8 PM. AT 645 PM THE BUFFALO COUNTY SHERIFF REPORTED 2 INCHES OF SNOW IN KEARNEY AS WELL AS 12 CAR ACCIDENTS. WITH THE RADAR SHOWING THE ECHOES UP TO 24 DBZ AGAIN...APPEARS ANOTHER 1-2 INCHES IS IN STORE FOR THIS AREA TONIGHT. NEW 00Z RUC SHOWING THE H7 TROF FROM VTN TO NEAR MCK...WITH A VERY SLOW PROGRESSION EAST THANKS TO THE UPPER RIDGE JUST TO OUR EAST. 290K ISENTROPIC SURFACE SHOWS MODERATE UPGLIDE ON THAT SURFACE THROUGH 09Z...WITH THE DPVA ESTABLISHED FROM THE UPSTREAM VORT MAX. THUS THE MECHANISMS SHOULD CONTINUE TO BE IN PLACE FOR SEVERAL MORE HOURS. WITH THIS IN MIND...HAVE ISSUED A SNOW ADVISORY FOR THE TWO COUNTIES UNDER THE HEAVIER BAND FOR TONIGHT...WITH 3-4 INCHES MENTIONED. ELSEWHERE THE SNOW HAS NOT BEEN ACCUMULATING MORE THAN 1/2 INCH. THE AIR OVER OUR EASTERN COUNTIES REMAINS VERY DRY ON THE BACK SIDE OF THE SURFACE HIGH. ECHOES OVER OUR SE COUNTIES...MAINLY SRN THAYER COUNTY...ARE APPARENTLY NOT CAUSING PROBLEMS AS CALLS TO THAYER COUNTY INDICATE NO ACCUMULATIONS OR ROAD PROBLEMS. GID...SNOW ADVISORY FOR BUFFALO AND KEARNEY COUNTIES TONIGHT. NIETFELD ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 900 PM EST TUE JAN 25 2000 ARCTIC HIGH PRESSURE CONTINUES TO DOMINATE. NO CHANGES PLANNED FOR THE 1000 PM UPDATE. TONIGHT/S LOWS APPEAR A LITTLE LOW BASED ON CURRENT TEMPERATURES BUT THE SURFACE ANALYSIS SHOWS DRY AIR ADVECTION...AND THE RUC SHOWS THE PRESSURE GRADIENT DIMINISHING TOWARD 06Z SO PLAN TO LEAVE TONIGHT/S FORECAST AS IS. .CAE...NONE. RJL sc AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 859 PM CST WED JAN 26 2000 ABR RADAR...SATELLITE AND SFC OBS CONTINUE TO SHOW AN AREA OF -SN IN C SD DISSIPATING THIS EVENING. MDLS CONTINUE TO SHOW SHARP MEAN RH GRADIENT FROM W TO E ACROSS THE CWA WITH THICKER AND LOWER CLOUDS IN C AND NC SD AND THINNER AND HIGHER CLOUDS ACROSS THE REST OF THE CWA. THE DEEPER MOISTURE ONLY MAKES SLOW PROGRESS INTO FAR NE SD AND WC MN BY MORNING. THEREFORE...SKIES WILL REMAIN CLOUDY ACROSS C AND NC SD WITH SKIES BECOMING MOSTLY CLOUDY ELSEWHERE. RUC SHOWS A GOOD SFC PRES GRAD THROUGH THE NIGHT. THEREFORE...THE WINDS WILL STAY UP FROM THE SE. WITH DIFFERENCES IN CLOUD COVER...THERE WILL ALSO BE QUITE A DIFFERENCE IN LOW TEMPS TONIGHT. NEAR 25 FAR SW CWA AND NEAR 5 BELOW FAR NE CWA. HAVE UPDATED FORECAST TO MAKE SOME SLIGHT ADJUSTMENTS. .ABR...NONE MOHR sd AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE SAN ANGELO TX 944 PM CST WED JAN 26 2000 LEAD 5H SHORTWAVE TROUGH CONTINUED TO SKIRT ACROSS WEST CENTRAL TEXAS AT 03Z. SAID WEAK DISTURBANCE WAS PRODUCING SOME RETURNS PER MOSAIC RADAR COMPOSITE... FROM SAN ANGELO TO DALLAS-FORT WORTH. BUT MUCH OF THE PRECIPITATION NOT HITTING THE GROUND... I.E VIRGA. AT THE SURFACE... A WARM FRONT STRETCHED FROM STERLING CITY TO BROWNWOOD. SOUTH OF THE FRONT... DEWPOINTS CONTINUE CLIMB. NORTH OF THE FRONT... A SHALLOW COLD... DRY POCKET OF AIR REMAINED WEDGED NEAR THE SURFACE. UPSTREAM... A 5H CLOSED LOW COULD BE SEEN ENTERING NORTHWEST NEW MEXICO... MOVING EAST-SOUTHEAST. 80 METER HEIGHT FALLS AND RECENT LIGHTNING ACTIVITY NEAR ABQ SUGGEST DISTURBANCE PACKS A PUNCH. WE/LL MAKE COSMETIC CHANCES TO THE INHERITED FORECAST. WITH THE 850 MB LOW LEVEL JET INCREASING TO 50 KTS OVERNIGHT... SURMISE THE WARM FRONT WILL CONTINUE LIFTING SLOWLY NORTHWARD... PERHAPS EVEN NORTH OF I-20 BY DAWN. THIS POSES PROBLEMS IN REGARDS TO PRECIPITATION TYPE. STRONG WARM AIR ADVECTION COULD PROMOTE THE LIQUID VARIETY...RATHER THAN FREEZING. BUT IN LIGHT OF WETBULB COOLING... WE/LL NOT TINKER WITH GOING ADVISORY AREA. ANY PRECIPITATION THAT DEVELOPS OVERNIGHT SHOULD BE CONCENTRATED ALONG AND NORTH OF THE WARM FRONT. FOR THE REMAINDER OF THE AREA... INCLUDING SAN ANGELO... MEASURABLE PRECIPITATION LIKELY TO BE ASSOCIATED WITH THE COLD FRONTAL PASSAGE ON THURSDAY. NEW RUC PAINTS DEEPER MOISTURE ACROSS THE HEARTLAND AND NORTHWEST HILL COUNTRY BY 12Z THU. AS A RESULT... RAINFALL AMOUNTS HIGHER FURTHER EAST ON THURSDAY. .SJT...WINTER WEATHER ADVISORY TONIGHT AND THURSDAY FOR BIG COUNTRY... INCLUDING ABILENE. 17 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 253 AM CST THU JAN 27 2000 THE MAIN FORECAST PROBLEM IS WHEN WILL THE ATMOSPHERE BEGIN TO SATURATE SO SN CAN BEGIN. HOW MUCH SN? & TIME PERIOD OF ACCUMULATION SN? 00Z SGF SOUNDING WAS VERY DRY BELOW 4KM OR THE LOWER 12000' WITH DRIER AIR FROM THE E/NE FLOW CONTINUING FROM 85/70H. AREA SFC DEW PTS EXTREMELY DRY WITH TEENS/SINGLE DIGITS THRU MOST OF THE OZARKS. NOT UNTIL NE OK DUE DEW PTS RISE INTO THE 20S. REGIONAL RADAR SHOWING MAINLY -SN ACROSS KS. RETURNS IN MO WERE FLURRIES AT BEST... BUT MORE LIKELY STILL VIRGA. A STRONG BAND OF SN WAS DEVELOPING ON THE LEFT EXIT REGION OF THE 50H JET STREAM OVR TX/OK PANHANDLE MOVING INTO SW KS. THIS WILL PLAY THE MAIN ROLE TODAY ACROSS SE KS/EXT SW MO AS THE DYNAMICS WITH THIS SYSTEM MOVES FURTHER EAST. 06Z RUC 280/285/290K UPGLIDE THRU 15Z SHOWING PRES DEF NEAR ZERO OVR ALL OF OK/TX IN S KS... BUT NOT MAKING MUCH PROGRESS EAST INTO SE KS/SW MO. 00Z ETA/AVN/NGM ALSO SHOWING A BROAD AREA OF PRES DEF AT 280/285/290K UPGLIDE NEAR ZERO ACROSS OK/S KS/N TX THRU 18Z THU... WITH A SLOW PROGRESSION TO THE NE INTO SE KS/SW MO BY 00Z FRI. NGM MORE AGGRESSIVE WITH THE SPEED WITH ETA SOMEWHAT LESS. WILL LEAN TOWARD THE AVN WITH SPEED AND CONTINUITY. WITH THIS... BELIEVE THE ONSET OF SN IN SE KS/EXT SW MO AFT 18Z. SGF/BRANSON AREAS NOT UNTIL AFT 00Z FRI. OVERALL MODELS DECREASE AND MOVE THE UPPER LEVEL DYNAMICS WITH THE SYSTEM FROM THE NM THRU C TX AND C AR BY 06Z FRI. HOWEVER LATEST WND PROFILES & 06Z MODEL GUIDANCE SHOWING THE SYSTEM ALREADY MOVING FASTER THAN INDICATING ATTM. SO THE PROGRESSION OF SN MAY BE FASTER THAN THOUGHT. HOWEVER DO NOT BELIEVE ATMOSPHERE WILL SATURATE IN THE OZARKS UNTIL 00Z FRI (ONLY EXT SW MO/SE KS). THIS LEADS TO SOME UNCERTAINTY OF SN AMTS ACROSS THE AREA THIS AFTN & TONIGHT. SNOW ADVISORY WILL PROBABLY BE NEEDED IN EXT SW MO DURING THE AFTN & THU NIGHT. THE REMAINDER OF THE OZARKS MAY NEED AN ADVISORY FOR THU NIGHT... BUT STILL NOT CONFIDENT ON AMTS... BUT SINCE 1-3 INCHES WILL BE POSSIBLE BEFORE FRI MORNING... MAY ADD A SNOW ADVISORY FOR AREAS S OF I-44 FOR THU NIGHT. WILL COORD WITH OTHER OFFICES ON THIS ISSUE. AFT 12 FRI DEEPEST MOISTURE MOVES OFF TO THE E/NE WITH ONLY -SN OR FLURRIES AT BEST ACROSS THE REMAINDER OF FA. ANOTHER PROBLEM IS ALL MODELS ARE INDICATING A LARGE UPPER LOW DEVELOPING OVR THE CENTRAL U.S. BY SAT. ALSO AVN SHOWING MORE LIFT AND MOISTURE MOVING BACK INTO FA BY SAT MORNING WITH POSSIBILITY ANOTHER BATCH OF SN FOR THE BEGINNING OF THE WEEKEND. WILL LET NEXT SHIFT HANDLE THIS PROBLEM AS STILL SOME UNCERTAINTY WITH THIS ALSO. WILL LEAN TOWARD THE WARMER MOS NUMBERS SINCE TEMPS NEAR FAN NUMBERS FOR TODAY HIGHS ALREADY. AFTER COORDINATION WITH OTHER OFFICES... WILL INTRODUCE A WINTER STORM WATCH FOR AREAS SOUTH OF I-44 FOR TONIGHT AND FRIDAY. SINCE A WINTER STORM WARNING IS ALREADY IN AFFECT FOR COUNTIES BORDERING SW MO & SC MO. DO NOT THINK AMOUNTS WILL BE GREATER THAN 6 INCHES IN 12 HRS... HOWEVER ISOLATED AMTS WILL BE POSSIBLE IN THIS AREA... AND WITH CONFIDENCE THIS SYSTEM IS NOT HIGH. THANKS FOR COORDINATION TUL/ICT/LIT/TOP/EAX. PRELIMINARY CCF NUMBERS SGF CM 028/022 026/016 028 25-853 JLN MM 027/017 030/020 032 256853 UNO CS 027/015 028/016 030 25-853 VIH CM 023/015 024/015 026 25-252 .SGF...SNOW ADVISORY THIS AFTN & TONIGHT FOR AREAS SOUTH OF A LINE FROM GIRARD KANSAS TO KIMBERLING CITY MISSOURI. WINTER STORM WATCH TONIGHT AND FRIDAY FOR AREAS SOUTH OF A LINE FROM GIRARD KANSAS TO SPRINGFIELD TO AVA AND ALTON MISSOURI. JLT mo SOUTHEAST TEXAS FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 1045 AM CST THU JAN 27 2000 ...HAVE ADDED MADISON COUNTY TO THE HOUSTON AND TRINITY COUNTY WINTER WEATHER ADVISORY... TOUGH FORECAST... FIRST ISSUE IS THE THREAT OF SEVERE WEATHER IN SOUTHERN ZONES. SUBSTANTIAL CAP EXISTS BASED ON MODEL SOUNDINGS AND CRP SOUNDINGS. WARM FRONT JUST SOUTH OF PSX AND COMES ONSHORE AT ROCKPORT. EXPECT THE FRONT TO REMAIN QUASI STATIONARY THROUGH NOON AND THEN BEGIN TO INCH NORTHWARD...PROBABLY MAKING ONSHORE AROUND FREEPORT AROUND 3 PM. ENVIRONMENT NEAR THE BOUNDARY VERY RICH WITH SHEAR...HELICITY > 250 AND CAPE NEAR 500...BUT THE BIG HINDRANCE IS THE CAP. ATTM THE THREAT OF STORMS GETTING THAT ORGANIZED IS SLIM. WILL LEAVE MENTION OF SEVERE IN THE PREVIOUS ZONES. SECOND ISSUE IS THE THREAT OF SLEET OR FREEZING RAIN IN HOUSTON AND TRINITY COUNTIES. HAVE CONTACTED THE EM IN HOUSTON COUNTY AND T 37F/DWPT 21F AS OF 9 AM. TEMPERATURES NOT LIKELY TO RISE AT ALL IN NORTHERN ZONES SO WILL LOWER ACCORDINGLY. RUC SOUNDINGS SUPPORT A BRIEF POSSIBILITY OF FREEZING PRECIP/SLEET BUT ACCUMULATIONS SHOULD BE MINIMAL IF AT ALL. AFTER GOOD COORDINATION FTW ON THIS ISSUE WILL ISSUE AN ADVISORY AFTER 10 AM FOR ABOVE MENTIONED PRECIP. IN THE MEANTIME WILL ADD THUNDER TO ALL ZONES AS MID LEVEL INSTABILITY INCREASING WITH APPROACH OF THE UPPER SYSTEM WHICH IS BECOMING READILY APPARENT PER 88D/LTG PLOTS. WILL ALSO BUMP UP WINDS ON COASTAL WATERS. QUICK LOOK AT THE 12Z ETA INDICATING THE POSSIBILITY OF SNOW 36 TO 48 HOURS (YUCK AND ARGH!)...WILL SCRUTINIZE THIS MORE CLOSELY AND MAKE DECISION IN AFTERNOON ON THIS ISSUE. .HGX...HIGH ISLAND TO MATAGORDA SHIP CHANNEL 0-60NM AND BAYS. ...WINTER WEATHER ADVISORY FOR MADISON...HOUSTON...TRINITY COUNTIES. 45/43/35 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1017 AM CST THU JAN 27 2000 JUST SENT OUT A QUICK UPDATE TO ACCOUNT FOR THE BULK OF THE PRECIP MOVING OFF TO THE EAST. STILL SEEING SOME LIFT AS THE UPPER LOW OVER THE SOUTH PLAINS DROPS SOUTHEAST. IN FACT...RADAR REFLECTIVITIES INCREASING ACROSS THE NORTHERN BIG COUNTRY...WITH CALLS TO THE THROCKMORTON COUNTY SHERIFF INDICATING SNOW. GIVEN THE PATH OF THE UPPER LOW ACROSS THE NORTHERN BIG COUNTRY...WILL CONTINUE THE WINTER WEATHER ADVISORY FOR THE BIG COUNTRY. LATEST ETA AND RUC SUGGEST SOME PARTIAL CLEARING ACROSS THE SOUTHWEST COUNTIES...WITH SOME CLEARING ALREADY NOTED ACROSS WESTERN CROCKETT COUNTY. DID PULL OUT THE 3 MOST SOUTHWEST COUNTIES TO MENTION PARTIAL CLEARING AND SLIGHTLY WARMER READINGS. IN GENERAL... LEFT TEMPERATURES ALONE FOR THE AFTERNOON. HOWEVER...DID KNOCK DOWN FORECAST HIGHS QUITE A BIT ACROSS THE HEARTLAND...WHERE COLD ADVECTION...CLOUD COVER...AND CURRENT TEMPERATURES IN THE LOW TO MID 30S MAKE UPPER 40S LOOK OUT OF REACH. 07 tx SOUTHEAST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 954 AM CST THU JAN 27 2000 TOUGH FORECAST... FIRST ISSUE IS THE THREAT OF SEVERE WEATHER IN SOUTHERN ZONES. SUBSTANTIAL CAP EXISTS BASED ON MODEL SOUNDINGS AND CRP SOUNDINGS. WARM FRONT JUST SOUTH OF PSX AND COMES ONSHORE AT ROCKPORT. EXPECT THE FRONT TO REMAIN QUASI STATIONARY THROUGH NOON AND THEN BEGIN TO INCH NORTHWARD...PROBABLY MAKING ONSHORE AROUND FREEPORT AROUND 3 PM. ENVIRONMENT NEAR THE BOUNDARY VERY RICH WITH SHEAR...HELICITY > 250 AND CAPE NEAR 500...BUT THE BIG HINDRANCE IS THE CAP. ATTM THE THREAT OF STORMS GETTING THAT ORGANIZED IS SLIM. WILL LEAVE MENTION OF SEVERE IN THE PREVIOUS ZONES. SECOND ISSUE IS THE THREAT OF SLEET OR FREEZING RAIN IN HOUSTON AND TRINITY COUNTIES. HAVE CONTACTED THE EM IN HOUSTON COUNTY AND T 37F/DWPT 21F AS OF 9 AM. TEMPERATURES NOT LIKELY TO RISE AT ALL IN NORTHERN ZONES SO WILL LOWER ACCORDINGLY. RUC SOUNDINGS SUPPORT A BRIEF POSSIBILITY OF FREEZING PRECIP/SLEET BUT ACCUMULATIONS SHOULD BE MINIMAL IF AT ALL. AFTER GOOD COORDINATION FTW ON THIS ISSUE WILL ISSUE AN ADVISORY AFTER 10 AM FOR ABOVE MENTIONED PRECIP. IN THE MEANTIME WILL ADD THUNDER TO ALL ZONES AS MID LEVEL INSTABILITY INCREASING WITH APPROACH OF THE UPPER SYSTEM WHICH IS BECOMING READILY APPARENT PER 88D/LTG PLOTS. WILL ALSO BUMP UP WINDS ON COASTAL WATERS. QUICK LOOK AT THE 12Z ETA INDICATING THE POSSIBILITY OF SNOW 36 TO 48 HOURS (YUCK AND ARGH!)...WILL SCRUTINIZE THIS MORE CLOSELY AND MAKE DECISION IN AFTERNOON ON THIS ISSUE. .HGX...HIGH ISLAND TO MATAGORDA SHIP CHANNEL 0-60NM AND BAYS. ...WINTER WEATHER ADVISORY FOR HOUSTON AND TRINITY COUNTIES. 45/43/35 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 330 AM CST THU JAN 27 2000 FCST FOCUS IS ON LK SHORE CLDS/PCPN TDA AND TEMPS TNGT. IN THE SHORT TERM...PESKY LK CLDS CONT TO STREAM S-SEWD...AT TIMES PUSHING INLAND WITH SOME FLURRIES. ETA/RUC H8 WNDS MAINTAIN NORTHLY OVR LK WHILE NGM/AVN SWING WINDS TO NNE DIRECTION THRU 00Z. HOWEVER NGM ODD PROG OUT AS IT KEEPS H8 TEMPS ARND 2 DEGREES C COLDER THAN OTR MODELS. TIME XSECTIONS FAVOR DRYING OF LOW LVL WITH TIME UNDER DECENT DWWD MOTION. RUC 925 MB WINDS FCST NNE FLOW OVR LK MI THRU AT LEAST 12Z B4 TURNING TO THE NW. SO BETWEEN 850 AND 925 MB EXPECT EROSION/EWD MOVEMENT OF CLDS ALNG LK MI DURING MRNG HRS. IN THE LONG TERM...WX NIL AS FAR AS WX SYSTEMS CONCERNED. HIGH PRES TO REMAIN ANCHORED OVR STATE AS ERN STORM VERY SLOW TO MOVE OUT WITH TIME AND MAIN UPPR JET RUNNING ACROSS SRN STATES. FAVOR ETA SOTION TWD LOWER TEMPS OVERNITE DUE TO OPTIMUM RADIATIONAL COOLING CONDITIONS...AND THUS WILL FCST TEMPS TNGT BLO GUID. OTRW DAYTIME HIGH TEMP FCST LOOKS GOOD AS DRY AMS OVR AREA SHOULD ALLOW FOR FAST TEMP RECOVERY. .UWNMS...KEEPS LK MI SNOW BAND OFF SHORE TDA. HINTS AT COOLER OVERNITE TEMPS UNDER HIGH ESPECIALLY IN WRN PARTS OF CWA LIKE ETA. .MKX...NONE. 0...0.../../ $$ ZAJDEL wi EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 300 AM PST THU JAN 27 2000 THROUGH FRIDAY FOR SOUTHWEST CALIFORNIA...MOSTLY CLEAR SKIES AND SEASONAL TEMPERATURES WITH LOCAL NIGHT AND MORNING CANYON WINDS. FOR THE WEEKEND...VARIABLE HIGH CLOUDS AND SLIGHTLY BELOW NORMAL TEMPERATURES. IN THE SHORT-TERM...NGM/ECMWF A LTL SHARPER WITH THE SHORTWAVE OVR THE PAC NW EVIDENT IN WATER VAPOR IMAGERY AND PREFERRED OVR THE WKR ETA/AVN. LOCALLY GUSTY NLY/NELY WINDS WL OCCUR THIS MORNING THRU AND BLO PASSES AND CANYONS...BUT BLO ADV LVLS. AS THE PAC NW SHORTWAVE CONTINUES TO DROP SOUTHEASTWARD TODAY...NELY SFC GRADIENTS AND ASSOCD WINDS SHOULD DROP OFF...THEN REBUILD LATE TONIGHT AND FRI MORNING BEHIND THIS SHORTWAVE AS IT MOVES ON TO THE E INTO THE SRN ROCKIES. OFSHR WINDS FOR FRI MORNING SHOULD BE A LTL STRONGER AND MORE WIDESPREAD THAN THIS MORNING...BUT STILL BLO ADV LVLS. WK CSTL EDDY EVIDENT IN SFC OBS THIS MORNING AND WELL CAPTURED BY BOTH THE RUC AND COAMPS. HOWEVER...WITH ACARS SOUNDINGS SHOWING LTL IN THE WAY OF A MARINE INVERSION AS A RESULT OF COOLING ALF THE PAST 24 HOURS.. ANY CSTL STRATUS SHOULD BE AT A MINIMUM THIS MORNING. PATCHY FOG IS STILL POSSIBLE EARLY THIS MORNING...MAINLY IN THE VLYS. OFSHR GRADIENTS TONIGHT/FRI MORNING...SHOULD KP ANY STRATUS TONIGHT OFF THE CST. EXTENDED...NEW AVN/MRF...UKMET...AND NOGAPS ALL SHOW THE POSSIBILITY OF ENERGY FM A FAST NRLY ZONAL JET OVR WRN AND CNTRL PAC BEGINNING TO DIVERT INTO THE SRN STREAM TOWARD CA AS A BLOCK DEVELOPS OVR THE CNTRL U.S. NW THRU THE NRN ROCKIES. THIS COULD BRING RAIN/SNOW BACK TO NRN AND CNTRL CA EARLY NEXT WEEK...BUT PROBABLY ONLY HIGH CLOUDS FOR MOST OF SRN CA. ECMWF/AVN/MRF ARE SIMILAR IN TRACKING A WK UPR LOW INTO SRN CA SAT. THIS SHOULD SPREAD MID AND HIGH LVL CLOUDS ACROSS SW CA...BUT WITH OFSHR LOW LVL GRADIENTS...SUSPECT THAT LOW LVL MSTR AND AND PRECIPITATION WL BE ABSENT...A FEW SPRINKLES OR LIGHT SHOWERS IN HIGHER ELEVATIONS AT MOST. SAN 000 .SAN...NONE. MARTIN ca SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO 338 AM MST THU JAN 27 2000 UNSETTLED WEATHER AND COLD TEMPERATURES EXPECTED FOR NEXT TWO DAYS. TDA: LATEST WATER VAPOR IMAGERY LOOP/RUC 500MB SHOWED SHORTWAVE TROUGH/OPEN LOW OVER CENTRAL NM AROUND 0830Z/72 THU. CURRENT IR SATELLITE IMAGERY TRENDS SHOWED POORLY ORGANIZED AND FRAGMENTED DEFORMATION CLOUD SHIELD ASSOCIATED WITH THE UPPER SYSTEM. ALSO... CLOUD TOPS HAVE BEEN WARMING OVER SOUTHEAST CO. APPEARS NEW DEFORMATION CLOUD/PRECIPITATION SHIELD FORMING OVER SOUTHWEST KS. REGIONAL WSR-88D RADAR TRENDS WERE NO BETTER IN SOUTHEAST/SOUTH CENTRAL CO. COVERAGE AND INTENSITY HAVE BEEN DECREASING. CALLS IN/OUT OF THE OFFICE ARE MAINLY FLURRIES ALONG I-25 CORRIDOR. AT 0930Z LHX HAD 1 INCH...SPRINGFIELD 3 INCHES...TRACE IN LAMAR AND TRINIDAD...SO FAR. 2-3 INCHES IN ALS. ALL SHORT RANGE MODELS ARE COHERENT ON HANDLING OF SYSTEM PASSING TO THE SOUTH. RUC VERIFING PRETTY GOOD WITH ETA/NGM SOLUTIONS...WITH AVN A TOUCH TOO FAR NORTH BY 12Z/27 THU...BUT CATCHES UP BY THU AFTERNOON. ONLY DISCONTINUITY IS THE ACTUAL/PREDICT TRACK FROM YESTERDAY...APPEARS IT WILL BE A LITTLE FURTHER SOUTH AS SYSTEM PULLS INTO THE RED RIVER VALLEY BY 00Z/28 FRI. THIS WOULD TAKE THE POTENTIAL HEAVY RECITATION TRACK FURTHER SOUTH OUT OF CO. 700-500MB AND 500-300MB QS DIV SHOWING STRONG SUBSIDENCE MOVING PULLING INTO CWFA BETWEEN 12Z-18Z/27 THU WHICH SHOULD PUT THE NAIL IN THE COFFIN ALONG WITH RELATIVELY DRIER AIR MOVING IN WITH IT. NEXT MID-LEVEL SHORTWAVE TROUGH HEADS INTO NORTHERN CO BY THU EVENING. RADAR INTENSITIES HAVE DIMINISHED SIGNIFICANTLY SINCE WE WALKED IN THE DOOR...HOWEVER COVERAGE STILL RUNNING IN THE LIKELY OR CAT RANGES. NOT REALLY EXPECTED MUCH IN THE WAY OF ADDITIONAL SIGNIFICANT SNOWFALL. HOWEVER...HATE TO PULL HEADLINES WHILE PRECIPITATION IS FALLING...ALBEIT -SHSN OR FLURRIES. THERE SHOULD ONLY BE AN ADDITIONAL 1 INCH OR LESS ALONG THE I-25 CORRIDOR BEFORE DIMINISHING BY 8AM-9AM. FOR CONTINUITY AND A MORE COHERENT VIEW OF THE STORM... PLAN TO CONTINUE ADVISORY FOR 65/66/67/71/72/73/74/75 UNTIL 8AM AND MENTION TOTAL STORM ACCUMULATIONS OF 3-6 INCHES. WILL KEEP 77 AND 81 UNTIL NOON TODAY AS THEY WILL BE CLOSER TO HEAVIER PRECIPITATION TRACK...BUT GIVEN SATELLITE AND RADAR TRENDS MAY NOT AMOUNT TO MUCH. CURRENT MOS TEMPERATURES ARE IN-LINE WITH ZFP SO WILL FOLLOW FOR TDA. TNGT/FRI: SERIES OF MID-LEVEL SHORTWAVE TROUGHS TO ROTATING THROUGH NORTHWESTERLY UPPER FLOW AROUND LARGE CYCLONE MOVING INTO THE NORTHERN/CENTRAL PLAINS. PRETTY COLD AIR MASS ASSOCIATED WITH THIS SYSTEM. -14 TO -16 DEG C 700MB TEMPERATURES TO INVADE CO TNGT/FRI. ETA/AVN PROGGING NORTHWESTERLY LOW/MID LEVEL FLOW... WHILE NGM FOR SOME REASON GOING WITH AN EAST UPSLOPE FLOW. MOISTURE PRETTY SHALLOW ACROSS CWFA. MID-LEVEL LAPSE RATES PROGGED TO BE 6.0- 7.0 DEG C/KM...SO COULDN'T RULE OUT -SHSN JUST ABOUT ANYWHERE...BUT MAINLY IN THE MOUNTAINS. FWC MOS HAS INCREASED POPS TO HIGH CHANCE/LIKELY FOR TNGT/FRI. HAVING HARD TIME BELIEVING THIS SINCE SUCH A DRAMATIC CHANGE. CURRENT ZFP HAS 20 POPS WHICH LOOKS GOOD RIGHT NOW. MAIN WEATHER FEATURE WILL BE BELOW NORMAL TEMPERATURES. EXTENDED(SAT-MON): WILL CONTINUE EFP AS MOST OF THE ENERGY/THINKING HAS GONE INTO THE NEXT 12-36HR FORECAST. .PUB...SNOW ADVISORY UNTIL 8AM TODAY 65/66/67/71/72/73/74/75 SNOW ADVISORY UNTIL 12PM TODAY 77/81. METZE co