AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 910 AM EST THU JAN 20 2000 COLD FRONT CONTINUES TO SWEEP SE THROUGH CWA. RADAR INDICATES LAST OF LIGHT RAIN HAS EXITED SE ZONES...WITH CLOUDS ALSO RAPIDLY EXITING. WINDS ARE CURRENTLY STRONGER THAN FORECAST...BUT RUC PROGS SUGGEST THAT THIS SHOULD BE RELATIVELY BRIEF IMMEDIATELY BEHIND FRONT. WILL PROBABLY RAISE COASTAL WATERS WINDS AND SEAS BASED ON BUOY TRENDS. STRONG CAA SEEN AT 850MB AND THE SURFACE THIS MORNING SUGGESTS THAT TEMPERATURES WILL BE SLOW TO RISE TODAY IN SPITE OF GOOD INSOLATION. MAY LOWER MAX TEMPERATURES IN A FEW LOCATIONS. RED FLAG WARNING STILL LOOKING ON TRACK BASED ON STRONG WINDS AND LOW RH VALUES THIS AFTERNOON. .TLH... AL...NONE. GA...NONE. FL...SCA ALL COASTAL ZONES TODAY. RED FLAG WARNING THIS AFTN ALL FL ZONES. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 925 PM EST THU JAN 20 2000 SC FADING OVR SRN SECTIONS OF FA WITH THE EXCEPTION OF MTN ZONES LATE THIS EVENING. STILL A FEW CLOUDS ON NRN CUMBERLAND PLATEAU BUT BELIEVE THESE WILL ERODE IN THE NEXT FEW HOURS. WILL UPDATE FCST TO ACCOUNT FOR IMPROVEMENT IN SKY CONDITION AND RELAXING PRES GRAD WHICH IS RESULTING IN WINDS DROPPING BELOW 10 MPH IN MOST AREAS. CHECKED LATEST RUC AND 950-925 MB WINDS REMAIN IN ADVISORY CATEGORY UNTIL SHORTLY AFTER MIDNIGHT SO WILL LET ADVISORY RIDE AND WILL UPDATE MTN ZONES AROUND THE MIDNIGHT HOUR WHICH COINCIDES WITH EXPIRATION. .MRX... NC...WIND ADVISORY TNZ018-041-043-045-047-072-074-087-102-210500. TN...WIND ADVISORY NCZ060-061-210500. VA...NONE. 20 tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 904 PM EST THU JAN 20 2000 INTENSE STORM TO CONTINUE TO BOMB AS IT MOVES TO THE SE OF SOUTHERN NEW ENG TONITE. THIS STORM TO CONTINUE TO MOVE UP INTO THE CANADIAN MARITIMES BY LATER ON FRI...AS A RIDGE OF HI PRESS BUILDS INTO THE GREAT LAKES REGION. PRESS GRADIENT TO INCREASE IN BETWEEN THESE TWO SYS (AND ACRS THE FA) THRU 00Z SAT. H5 TROF TO MOVE INTO THE FA FROM THE WEST TONITE AND REMAIN ACRS THE FA THRU FRI. INTERESTING TIDBIT...TROPOPAUSE FOLD TO MOVE SE ACRS ONT TONITE AND THEN ACRS NY STATE (TOWARDS THE BIG APPLE) ON FRI. 18Z 40KM RUC (NO 21Z RUC AVAIL AT ALL HERE AND NO 00Z RUC YET IN N- AWIPS) SHOWS SFC WINDS BECOMING NW ACRS THE FA BY 06Z. TEMPS TO GET DOWN INTO THE POSITIVE SINGLE NUMBERS ALMOST EVERYWHERE BY 06Z AS WELL. H85 MOISTURE DECREASING AS UPR TROF APPROACHES FROM THE WEST. -SHSN TO CONTINUE THROUGH THE LATE EVENING HOURS. ACCUMULATIONS SO FAR APPEAR TO BE MOSTLY A DUSTING TO 1-2" IN SPOTS. ANOTHER BIG 2 TENTHS OF INCH HERE AT BTV...AGAIN...WOW. FA TO BE UNDER H85 CAA THRU 00Z SAT (STRONGEST TO TAKE PLACE 12Z FRI TO 00Z SAT). H85 MOISTURE TO LINGER ACRS THE FA (ESPECIALLY IN VT) THRU 00Z SAT AS WELL. N-NW FLOW TO DEVELOP ACRS THE FA BY 06Z TONITE AND CONTINUE RIGHT THRU THE DAY ON FRI. ANY LES TO STAY WELL TO THE SOUTH OF THE FA THRU FRI. HAVE GONE WITH LIKELY POPS IN THE CHAMP VLY FOR THE REMAINDER OF THE NIGHT...SCT POPS IN SRN VT AND THE ST LAW VLY...WITH CATEGORICAL POPS IN THE MTN ZONES. BACK EDGE OF STEADY SN ON IR SAT PIX SHOULD MOVE THROUGH THE ST LAW VLY AND THE ADIRONDACKS BY AROUND 08Z. 88D IMAGERY NOT VERY IMPRESSIVE TONITE. -SHSN TO TAPER OFF TOWARDS MORNING IN THE REMAINDER OF THE FA. FRI/S FORECAST OF SHSN (ESPECIALLY IN THE MTN ZONES) STILL LOOKS GOOD FROM HERE. HAVE JUST ADDED MENTION OF FLURRIES TO TONITE/S AND TOMORROW/S ZONES. TWEAKED LOW TEMP FORECAST FOR TONITE BASED ON CURRENT TRENDS AND 20Z LAMP DATA. ANY OTHER CHANGES TO ZFP VERY MINOR. MID-SHIFT WILL HAVE TO LOOK INTO WIND CHILL BANNERS FOR FRI WITH INCREASING SFC WINDS AND NIPPY TEMPS. WIND CHILL MAY TOUCH -30 DEG F OVER ON THE NY SIDE BY MORNING. WORK ZONES GONE. FINAL ZFP AFTER QUICK LOOK AT 02Z OBS. .BTV...NONE. MURRAY vt EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 PM PST THU JAN 20 2000 THE FIRST FOUR PERIODS OF THIS FORECAST DEAL WITH TWO SEPARATE SYSTEMS. THE FIRST IS NOW COMING ASHORE THE OREGON COAST WITH THE SECOND CURRENTLY LOCATED NEAR 40N 137W. 12Z MODELS SEEMED TO HAVE A LOUSY HANDLE ON THE FIRST SYSTEM...BUT THE 18Z ETA AND 21Z RUC SEEM TO HAVE A BETTER HANDLE. LOOKING FOR PRECIP TO CROSS THE CASCADES THIS EVENING AND REACH OUR ERN ZNS BY SUNRISE. EXPECTED SNOWFALL AMOUNTS ARE QUITE LIGHT EXCEPT NEAR A POSSIBLE DEFORMATION ZONE ACROSS OUR NORTHWESTERN ZONES TONIGHT. BLUE MOUNTAINS ARE MORE LIKELY TO PICK UP HEAVIER SNOW AFTER 850-700 MB WINDS SHIFT FROM SOUTHWEST TO WEST AFTER 12Z FRI. NO HEADLINES IN THE FIRST PERIOD DUE TO LIGHT AMOUNTS. SECOND SYSTEM IS ALREADY BETTER ORGANIZED THAN THE FIRST SYS WAS WHEN IT WAS IN THE SAME LOCATION. SHOULD AFFECT THE AREA FROM LATE FRI AFTN THROUGH FRI NGT. PRECIP SHOULD CUT OFF ALONG THE EAST SLOPES ON FRI EVNG AS MID-LEVEL FLOW BECOMES MORE WESTERLY. EXTENDED...SPLIT FLOW PATTERN LEADS TO LOWER CONFIDENCE IN THE EXTENDED WITH A MAINLY MOUNTAIN SNOW SHOWER REGIME EXPECTED. AWH/TC ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 023/032/025/033 4563 CQV 020/029/022/030 6672 S86 017/029/021/030 5673 COE 021/033/024/033 4563 WWP 019/030/022/031 4685 LWS 032/040/033/039 3554 MOS 027/034/026/033 EAT 022/029/022/031 4421 .GEG...NONE. wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 230 PM CST THU JAN 20 2000 SHORT RANGE MODELS AGREE WELL ON KEEPING BRISK AND DEEP NORTHWESTERLY FLOW ACRS UPPER MIDWEST ON WEST SIDE OF POLAR VORTEX THROUGH MIDDAY FRI...BEFORE UPPER FLOW FLATTENS OUT TO A MORE ZONAL/ PROGRESSIVE REGIME FRI NIGHT. MAIN FORECAST CONCERNS THIS PACKAGE ARE WITH POSSIBLE CLOUDS AND LOW TEMPS TONIGHT...AND NEXT UPSTREAM WX MAKER LATE IN PERIOD. W/V IMAGERY INDICATES WEAK VORT IN QUICK NORTHWEST FLOW DIPPING INTO EAST ND-NORTHWEST MN AT 18Z. NGM ACTUALLY INITIATING AND HANDLING THIS FEATURE BEST THROUGH 18Z. THIS FEATURE AND IT/S SUBTLE LIFT RESPONSIBLE FOR STRATUS AND FLURRIES THAT THE 11-3.9 IR FOG IMAGERY SHOWS NICELY ACRS ND...SOUTHWEST MN...AND INTO NORTH CENTRAL IA. THIS AREA OF STRATUS PATCHES LINES UP REASONABLY WELL WITH RUC AND ETA H85 70+ RH FIELDS AT 18Z. SATELLITE LOOPS DO INDICATE THIS ST GETTING EATEN AWAY AT AS IT TRIES TO HEAD SOUTH INTO CENTRAL IA...PROBABLY DUE TO IT ENCOUNTERING SUBSIDENCE AND DRY AIR/HIGH COND PRES DEFICITS. RESPONSIBLE VORT PROGGED BY ALL SHORT RANGE MODELS TO QUICKLY SHEAR SOUTHEAST AND ACRS THE DVN CWA BETWEEN 00Z-06Z FRI...WEAKENING AS IT DOES. ETA RH PROGS DO SWIPE FAR WESTERN FRINGES OF CWA WITH 70+ H85 RH CONTOUR OVERNIGHT... ALTHOUGH STRATUS IS OOZING ALONG RUC H7-H3 MB THICKNESS FIELDS NICELY...WHICH WOULD EVENTUALLY LEAD IT ACRS MUCH OF THE NORTHERN HALF OF THE CWA...NOT JUST THE WEST. FEEL IT WILL CONTINUE TO HAVE PROBLEM BATTLING DRY FORCES HOWEVER...AND JUST A FEW FRAGMENTS MAY MAKE IT THIS FAR SOUTHEAST. WILL WATCH SATELLITE TRENDS AND MAKE CALL CLOSE TO ISSUANCE TIME. FEEL AT WORST PARTLY CLOUDY WITH A FEW FLURRIES WORDING FOR PORTIONS OF THE CWA. AS FOR TEMPS TONIGHT...GUIDANCE WAS RUNNING 4-9 DEGREES F TOO WARM ALREADY ACRS THE CWA AT 18Z...THUS AGAIN NOT HANDLING ARCTIC INFLUX PROPERLY. AS RIDGE AXIS AND LIGHT WINDS ALIGN ACRS MID TO UPPER MS RVR VALLEY TONIGHT...SLAP-IN-THE-FACE COLD TO SETTLE IN... AS IF IT/S NOT HERE ALREADY! TRAJECTORIES CONTINUE TO ADVECT IN ARCTIC AIR OVER SNOW COVER SLIDE FROM WEST CENTRAL MN AND EAST SD SOURCE REGION...WHICH HIT -10 TO -18 LAST NIGHT. EVEN WITH SLIGHT MODIFICATION...GUIDANCE WILL HAVE TO BE WAY UNDERCUT. PREVIOUS SHIFT ALREADY SLASHED GUIDANCE AND ONGOING LOW TEMP VALUES LOOK GOOD... BUT MAY HAVE TO GO EVEN LOWER ACRS AREAS WITH DECENT SNOW COVER. NEXT WEATHER MAKER ALREADY SHOWING UP ON W/V IMAGERY OFF NORTHWEST COAST...WILL DROP IN FROM THE PACIFIC NORTHWEST AND SKIRT IN ACRS THE CONUS IN FLATTENING UPPER FLOW. THIS FEATURE LOOKS TO REACH THE UPPER MIDWEST BY 12Z SAT. OPERATIONAL MODELS DO VARY IN TIMING OF THIS VORT WITH ETA THE QUICKEST IN PROGRESSIVE FLOW... REACHING NORTHERN WI BY 12Z SAT...WHILE AVN AND NGM LAG ACRS NORTHWEST MN. MODELS HANDLE SFC FEATURES WITH TIMING/POSITIONAL DIFFERENCES SIMILARLY...WITH ETA OUT-RACING NGM/AVN ACRS NORTHERN MN AND INTO NORTHWEST WI BY 12Z SAT. ETA ALSO QUICKEST TO BRING IN LIGHT SNOW ACRS CWA FRI NIGHT JUST AFTER 00Z...WITH AVN LEANING TO MORE OF A 06Z-12Z TIMING. WITH SUCH PROGRESSIVE FLOW DEVELOPING... FEEL QUICKER ETA BETTER WITH SYNOPTIC SCALE FEATURES...ALTHOUGH FEEL A TOUCH OF AVN SHOULD BE APPLIED...FOR SLIGHTLY SLOWING ETA SOLUTION AND TIMING. WORRY ABOUT INITIAL DRY CONDITIONS TO DELAY PRECIP ONSET FRI NIGHT...BUT ALL MODEL 290 K ISENTROPIC SFC ANALYSIS PAINTS GOOD LIFT SCENARIO AFTER 00Z RIGHT ACRS CWA. COND PRES DEF/S ALSO SATURATE TO 30-10 MB ACRS CWA. FEEL THIS MAY BE TOO QUICK AND AGGRESSIVE...BUT WILL INTRODUCE POPS FOR FRI NIGHT ACRS ENTIRE CWA. BEST PERIOD FOR SNOWFALL LOOKS TO BE LATER FRI NIGHT AND SAT MORNING...BEFORE BEST LIFT/PRECIP POTENTIAL SHIFTS NORTHEAST. AVN ISENTROPICS SHOW LIFT SHUTS OFF BY 18Z SAT AND DRIES OUT AIRMASS SAT AFTERNOON...SNOW MAY TAPER TO FLURRIES. LARGER/MORE VIGOROUS SOUTHERN SYSTEM WILL HAVE MORE MOISTURE TO WORK WITH...BUT IT/S PRECIP SHIELD STAYS JUST TO THE SOUTH OF THE CWA SAT INTO SAT NIGHT. ...EXTENDED...NEXT SUN-MON-TUE... EUROPEAN/CANADIAN/MRF ALL CONTINUE REX BLOCKING PATTERN OFF OF THE WEST COAST ON SUNDAY AS NORTHERN AND SOUTHERN STREAMS PHASE INTO A GENERAL L/W ACRS THE UPPER MIDWEST/WEST GRT LKS. AGAIN WITH THIS LATEST RUN...DVN CWA REGION IN BETWEEN NORTHERN SFC SYSTEM OVER LK SUPERIOR...AND MORE VIGOROUS SOUTHERN SFC SYSTEM PUSHING ACRS THE GULF STATES. ALTHOUGH IN THE MIDDLE...MRF STILL ADVERTISES LIGHT SNOW ACRS THE AREA FOR MOST OF THE DAY/SUNDAY AS NICE VORT SKIRTS OVERHEAD. EURO IS MORE PROGRESSIVE WITH L/W AND ASSOCIATED SFC SYSTEMS...AND THUS SHIFTS PRECIP TO THE EAST QUICKER ON SUNDAY. WILL STILL LEAVE LIGHT SNOW MENTION FOR ENTIRE DAY FOR NOW. MONDAY STILL LOOKS DRY WITH SOME TEMP MODERATION AS LARGE SFC RIDGE SETTLES TO THE SOUTH...AND LOW LEVEL RETURN FLOW SETS UP ACRS THE AREA. EURO AGAIN SHOWING IT/S TOO AGGRESSIVE H85 WAA BIAS...AND EVEN MRF LOOKS A BIT OPTIMISTIC TAKING INTO ACCOUNT GOOD SNOW COVER AND LINGERING ARCTIC AIR. IN FACT...WILL AGAIN UNDERCUT FMR NUMBERS SOMEWHAT THROUGH ENTIRE PERIOD...ALTHOUGH THE MRF HAS TONED IT/S TEMPS DOWN FROM THE LAST RUN. NEXT UPSTREAM SYSTEM OF CONSEQUENCE WILL ROLL OUT OF THE GULF OF ALASKA LATER THIS WEEKEND AND OVER THE TOP OF THE REX BLOCK. THIS SYSTEM LOOKS TO EVENTUALLY DROP INTO AND REINFORCE THE L/W TROUGH ACRS THE UPPER MIDWEST...EVENTUALLY EVOLVING INTO A CUT-OFF LOW/POLAR VORTEX OVER THE GRT LKS BY MID NEXT WEEK. IN THE PROCESS...ASSOCIATED SFC LOW AND TROUGH WILL SWEEP ACRS THE UPPER MS RVR VALLEY MON NIGHT INTO TUE...BRINGING ANOTHER CHANCE OF LIGHT SNOW TO THE CWA. COORDINATED WITH ILX...THANX. .DVN... IA...NONE. IL...NONE. MO...NONE. JDH il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 923 PM EST THU JAN 20 2000 LES MULTIPLE BANDS STILL EVIDENT ON 88D. RUC AND 18Z ETA AGREE THAT THE INVERSION WL REMAIN ABV 6K FT UNTIL AROUND 09Z. WINDS STARTING TO BACK A LITTLE SO FETCH WILL BE LIMITING WITH TIME...BUT THE RESIDENCE TIME SHOULD INCREASE SLIGHTLY AS THE GRADIENT DECREASES. H8 TEMPS STILL AROUND -18 F. ALL FACTORS WEIGHED...WILL KEEP WSW UNTIL NEXT PKG. MEANWHILE WINDS ARE HIGH ENOUGH COMBINED WITH THE FRIGID TEMPS TO GIVE WC READINGS IN THE -20 TO -30 RANGE...SO ISSUED AN ADVISORY FOR IN/OH AWAY FROM THE LAKE. MI CRITERIA LOWER SO NO NEED THERE. SFC TEMPS WELL BELOW GUIDANCE AND GOING FCST REFLECTS THIS. THANKS FOR COORD...GRR. .IWX...WINTER STORM WARNING TONIGHT BERRIEN...CASS MI AND ST JOSEPH IN. WINDCHILL ADVISORY REST OF CWA EXCEPT MI. ADOLPHSON in SOUTHWEST OREGON/NORTHERN CALIFORNIA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MEDFORD OR 830 PM PST THU JAN 20 2000 CORRECTED TO ADD HEADLINE BELOW...AND TO CHANGE 1ST PD RBG POP CURRENT TRENDS IN RADAR AND SATELLITE WARRANT KILLING MOST POPS AND MTN SNOW ACCUMS. FEW LINGERING SHOWERS ARE GOING TO HAVE TROUBLE PRODUCING ANYMORE MEASUREABLE PRECIP...EXCEPT POSSIBLY COOS COAST...UMPQUA...AND WRN SISKIYOU CNTY. COOS THRU DOUGLAS COUNTIES LOOK TO BE IN LINE FOR A MORE FAVORABLE MOISTURE FEED...AND WILL KEEP CHANCES THERE. RAIN SHOULD INCREASE AGAIN BTWN 3-6 AM ON THE COAST IN ADVANCE OF THE NEXT VORT AND CONSIDERABLE AREA OF SHOWERS CURRENTLY SEEN ALONG 40N BETWEEN 130-135W. COMPROMISE BTWN THE LATEST RUC AND ETA FCSTS BRINGS THE VORT OVER 130W BY 12Z. THEREAFTER...ENERGY CONTINUES TO BE BROUGHT NWD AND FEEL THAT THE INTERIOR AND CASCADES COULD AGAIN BE FAIR IN THE MORNING (FOG-PENDING) WITH INCREASING CLOUDS AND LGT RAIN DEVELOPING IN THE AFTN...AND THAT MOST OF THE EAST SIDE WILL LIKELY SEE ANOTHER FAIR DAY WITH CLOUDS INCREASING BUT ONLY CHANCE OR LOWER POPS FOR THE AFTN. WILL MAKE SOME ADJUSTMENTS TO THE CURRENT ZONES TO TREND THE FCST TO THIS LINE OF THINKING. STAVISH .MFR...SMALL CRAFT ADVISORY FOR WIND FLORENCE TO POINT ST. GEORGE. OTH WE 043/050 040/050 042 098876 4BK WE 044/051 041/050 044 097876 RBG WE 038/048 037/046 036 095875 GPS WE 034/046 032/045 032 092774 MFR WE 035/046 034/045 033 091773 ASH WE 034/047 031/044 031 092773 CRL JJ 021/027 018/026 017 095885 HOW JE 029/034 023/032 021 092774 CHE EB 024/035 021/033 017 091332 SPG EB 022/037 020/032 016 091332 CHQ EB 024/036 021/031 034 091332 LMT EB 027/040 026/036 022 091332 LKV EB 024/042 025/035 020 091232 SVL EB 024/040 023/037 018 091232 YKA WE 030/045 026/045 024 093532 MHS OE 031/039 029/037 028 094653 AAT EB 024/043 022/039 018 091122 TUL EB 026/041 023/037 020 091332 MTH EB 025/041 023/038 021 091332 or SOUTHWEST OREGON/NORTHERN CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 830 PM PST THU JAN 20 2000 CURRENT TRENDS IN RADAR AND SATELLITE WARRANT KILLING MOST POPS AND MTN SNOW ACCUMS. FEW LINGERING SHOWERS ARE GOING TO HAVE TROUBLE PRODUCING ANYMORE MEASUREABLE PRECIP...EXCEPT POSSIBLY COOS COAST...UMPQUA...AND WRN SISKIYOU CNTY. COOS THRU DOUGLAS COUNTIES LOOK TO BE IN LINE FOR A MORE FAVORABLE MOISTURE FEED...AND WILL KEEP CHANCES THERE. RAIN SHOULD INCREASE AGAIN BTWN 3-6 AM ON THE COAST IN ADVANCE OF THE NEXT VORT AND CONSIDERABLE AREA OF SHOWERS CURRENTLY SEEN ALONG 40N BETWEEN 130-135W. COMPROMISE BTWN THE LATEST RUC AND ETA FCSTS BRINGS THE VORT OVER 130W BY 12Z. THEREAFTER...ENERGY CONTINUES TO BE BROUGHT NWD AND FEEL THAT THE INTERIOR AND CASCADES COULD AGAIN BE FAIR IN THE MORNING (FOG-PENDING) WITH INCREASING CLOUDS AND LGT RAIN DEVELOPING IN THE AFTN...AND THAT MOST OF THE EAST SIDE WILL LIKELY SEE ANOTHER FAIR DAY WITH CLOUDS INCREASING BUT ONLY CHANCE OR LOWER POPS FOR THE AFTN. WILL MAKE SOME ADJUSTMENTS TO THE CURRENT ZONES TO TREND THE FCST TO THIS LINE OF THINKING. STAVISH .MFR...NONE. OTH WE 043/050 040/050 042 098876 4BK WE 044/051 041/050 044 097876 RBG WE 038/048 037/046 036 098875 GPS WE 034/046 032/045 032 092774 MFR WE 035/046 034/045 033 091773 ASH WE 034/047 031/044 031 092773 CRL JJ 021/027 018/026 017 095885 HOW JE 029/034 023/032 021 092774 CHE EB 024/035 021/033 017 091332 SPG EB 022/037 020/032 016 091332 CHQ EB 024/036 021/031 034 091332 LMT EB 027/040 026/036 022 091332 LKV EB 024/042 025/035 020 091232 SVL EB 024/040 023/037 018 091232 YKA WE 030/045 026/045 024 093532 MHS OE 031/039 029/037 028 094653 AAT EB 024/043 022/039 018 091122 TUL EB 026/041 023/037 020 091332 MTH EB 025/041 023/038 021 091332 or TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 349 AM CST FRI JAN 21 2000 WEAK SFC TROUGH AT 07Z ACROSS NW CORNER FA BRINGING BRIEF WIND SHIFT THERE. OTRWS SRLY FLOW AT SFC CONTINUES ACROSS PNHDLS WITH CONSIDERABLE AMOUNT OF MID/HI LEVEL MOISTURE STREAMING OVER TOP OF BROAD UPPER LEVEL RIDGE. 09Z RUC DRIFTS SFC FEATURE SLOWLY S AND E ACROSS CENTRAL ZNS THIS MORNING BEFORE TURNING WINDS BACK TO SW IN RESPONSE TO APPROACHING ENERGY OUT W. H8 TEMPS FCST TO WARM CONSIDERABLY AND IF ALL MIXED OUT WOULD RESULT IN HIGHS NR 70. THINK HOWEVER THAT CLOUDS AND WEAK BOUNDARY DRIFTING ACROSS AREA WILL LIMIT HEATING SOME SO STUCK CLOSER TO GUIDANCE. LEFT NE CORNER COOLEST AS MODIFIED AIR REMAINS LOCKED IN PLACE AND WMFNT FAILS TO LIFT THAT FAR N. TEMPS CONTINUE TO BE CHALLENGE NEXT FEW DAYS AS UPPER PATTERN GRADUALLY SHIFTS FM A WRN RIDGE/ERN TROUGH TO A BROAD TROUGH COVERING MUCH OF U.S. AS SHRTWV ENERGY PASSES BY TONIGHT...SFC TROUGH SHOULD BE KICKED EWRD. SHORT RANGE MODELS CONTINUE TO ADVERTISE FALLING THCNKS ON SAT WITH NW-N LLVL FLOW. THIS WILL BRING TEMPS DOWN CLOSER TO NORMS BUT STILL ABOVE. IN EXTENDED...STRONGER SHOT OF COLD AIR ARRIVES EARLY SUN AS SHRTWV ROTATES SWRD FM CANADA. ADDITIONAL ENERGY TRAILS FM PAC NW TO CONTINUE STREAM OF MID/HIGH LVL MOISTURE WITH BEST PROSPECTS OF PRECIP ABV 12K FEET. NONE OF MED RANGE MODELS BEAR ANY RESEMBLANCE AT SFC SO TIMING OF REINFORCING SHOTS OF COLD AIR THROUGH TUE UNCERTAIN. PLAN ON KEEPING DOWNWARD TREND THOUGH BASED ON HIGH AMPLITUDE UPPER LEVEL PATTERN AND POSITION OF TROUGH AXIS E OF AREA. EARLY NUMBERS... AMA 64/36/57/25/45 DHT 61/33/57/23/43 .AMA... TX...NONE. OK...NONE. COBB tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 833 PM EST THU JAN 20 2000 SEVERAL CHANGES PLANNED TO CURRENT SET OF ZONES. LAKE EFFECT CLOUDS WORKING EAST INTO WESTERN COUNTIES CURRENTLY...WITH SNOW SHOWERS REPORTED AS FAR EAST AS ALMA TO HILLSDALE. 12Z ETA SHOWED INVERSION HEIGHTS ON SOUTHERN LAKE MI OF AROUND 800 MB AT 00Z...REASONING FOR THE SNOW SHOWER ACTIVITY THEN FALLING OVERNIGHT. CONSIDERING DRY AIR ADVECTING ACROSS LAKE...WHICH IS REFLECTED WELL IN LATEST RUC DATA COMPARED TO IR...WILL LIKELY CONTINUE TO SEE SOMEWHAT PATCHY NATURE TO CLOUDS...WITH FURTHER ENHANCEMENT IN THE SNOW SHOWER ACTIVITY NOT EXPECTED WITH FALLING INVERSION HEIGHTS. HENCE...WILL FAVOR A VARIABLE CLOUDINESS WORDING WITH THE CHANCE FOR SNOW SHOWERS EXTENDED FURTHER NORTH TO MATCH CURRENT NORTHWARD EXTENT. TEMPERATURES ARE A BIT TRICKY. WITH DEWPOINTS ANYWHERE FROM ABOUT -6 TO +6...THE PATCHY NATURE TO THE CLOUDS WILL PROVIDE FOR SOME UPS AND DOWNS OVERNIGHT. HENCE...WILL FAVOR A LITTLE COLDER FORECAST. WILL GO WITH A LOW TEMPERATURE FORECAST RATHER THAN RISING...AS A BREAK OF ANY DURATION AS IN CURRENT IR COULD PUSH READINGS RIGHT BACK DOWN. FLUCTUATIONS OF SEVERAL DEGREES UP AND DOWN THOUGH SHOULD BE COMMON OVERNIGHT. .DTX...NONE. STRUBLE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 942 AM MST FRI JAN 21 2000 WILL UPDATE THE FORECAST TO REMOVE MORNING WORDING AND WILL ALSO MAKE SOME CHANGES BASED ON CURRENT TRENDS. LIGHT SNOW IN KRWL AND MAINLY NORTHERN ALBANY COUNTY. MAY TWEAK TEMPS DOWNWARD IN A FEW PLACES GIVEN CLOUD COVER AND LIGHT WINDS MOST AREAS. LATEST RUC/ETA AND NGM ALL SHOW THE BEST CHANCE OF PRECIP OVER S CEN WY TODAY AND JUST A BRIEF PERIOD OF LIGHT UPSLOPE SNOW POSSIBLE OVER ERN PLAINS THIS AFTERNOON. .CYS... WY...NONE. NE...NONE. STARK wy AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 220 AM MST FRI JAN 21 2000 REGIONAL RADAR SHOWS MASS OF WEAK ECHOES ENTERING WRN WY FROM SERN ID AND NRN UT...APRNTLY ASSOCD WITH WK SHT WV IN SWLY UPR FLOW. IR SHWG MAINLY BKN MID/HI CLDS ELSEWHERE IN CWA. SFC ANAL/OBS LOOP INDICATES BACK BDRY OF ARCTIC AIRMASS EXITING ERN CWA AS WRM FNT AROUND MIDNITE. BLV NGM HAS BEST HANDLE OF 3 MDLS ON CRNT SITN AS FAR AS PCPN COVG GOES AND DOES BEST AT PICKING OUT APRCHG WK SHRT WV WHICH ALSO SHOWS UP WELL ON RUC. BASED ON ABV BLV ETA/MESOETA HAVE QPF BULLEYES TOO FAR SOUTH. WL PLACE ZONES 16-20 IN SNW ADVSRY. WL LV OUT 22-25 DUE TO XPCTD MIX OR CHGOVR TO RN AND SOME BLKG BY UINTAS. IN THE LONGER TERM...ALL THE MODELS OPEN UP THE UPR LOW OFF PAC NW BY 18Z TDY AND DAMPEN INTO E/W TROF ALONG WRN CANADIAN BRDR BY SAT 18Z. THIS WILL GRADUALLY TURN H5 FLOW MORE NWLY OVR WY WITH NRLY FLOW N OF CAN BRDR. ALL 3 MDLS BRING FRESH SURGE OF ARCTIC AIR FM WRN CAN SOUTHWRD INTO WY ON SAT AND WILL ADD CHC OF -SHSN MST SXNS. BLV AVN MAY BE TOO QUIK TO RETREAT FNTLY BDRY E H48-H72 AS AVN IS SOMETIMES APT TO DO AND WL FACTOR INTO FCST. XNTD...WL PRETTY MUCH FOLLOW PREV FCST...BUT BASED ON NEWEST MRF MAY COOL TEMPS A TAD. .RIW...SNOW ADVISORY FOR TODAY SOUTHWESTERN ZONES 16 THRU 20. DZ wy AREA FORECAST DISCUSSION. NATIONAL WEATHER SERVICE GOODLAND KS 203 PM MST FRI JAN 21 2000 ...FORECAST CONCERNS ARE TEMPERATURES AND CHANCES OF PRECIP... LATEST GUIDANCE INDICATING A GOOD VORT MAX IN THE ZONAL FLOW ALOFT WILL PASS THROUGH THE AREA AROUND 00Z THIS EVENING. THIS VORT MAX WILL INTERACT WITH A SURFACE LOW OVER SOUTHEAST COLORADO. MID LEVEL MOISTURE INCREASES AT THE SAME TIME WITH 850-700 MB LAPSE RATES INCREASING. THE AREA WILL ALSO BE IN THE LFQ OF THE 250 MB JET. NOT REALLY EXCITED ABOUT THE CHANCE OF ANY PRECIP...ESPECIALLY WITH A LACK OF AN UPSLOPE COMPONENT. AFTER LOOKING AT THE CANADIAN/LATEST RUC AND 18Z ETA...I DECIDED TO REMOVE THE MENTION OF PRECIP. THERES A BRIEF (3 HOUR) PERIOD OF UPWARD MOTION BUT IT QUICKLY DECREASES AFT 4Z. MOISTURE X-SECTIONS SHOW SUBSTANTIAL CLOUDCOVER EARLY TONIGHT BEFORE SUBSIDENCE ERODES MUCH OF THE CLOUDS. WILL GO NEAR GUIDANCE BUT FEEL IT MAY BE TO LOW. WILL AWAIT THE 18Z ETA. THE SURFACE LOW MOVES AWAY SATURDAY AS A WEAK SURFACE HIGH MOVES INTO THE NORTHEAST CWA. 850 COOL A FEW DEGREES SUGGESTING TEMPS NEAR 45. FWC GUIDANCE ALSO IN LINE WITH MY THINKING. WE'LL BE IN BETWEEN SYSTEMS SO SOME SUN SHOULD BE SEEN WITH SUBSIDENCE OVER THE AREA. NEXT WEEK SYSTEM FORECAST TO MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY MORNING. FORECAST CONTINUES TO INDICATE AN OVERNIGHT EVENT AND I SEE NO REASON TO DEVIATE...ESPECIALLY NOW THAT THE FWC HAS RAISED POPS TOWARD 30 PERCENT. AS FAR AS TEMPS...NOT VERY CONFIDENT THAT WE'LL DROP INTO THE TEENS WITH SOME PRECIP FALLING AND ABUNDANT CLOUDCOVER. DEWPOINTS ARE IN THE MIDDLE TEENS. WILL GO NEAR 20/LOWER 20S. SUNDAY WILL ALSO BE TRICKY AS COLD FRONT IS FORECAST TO BACK INTO THE AREA WITH THE NGM THE BOLDEST AND ETA/AVN A LITTLE MORE CONSERVATIVE. AVN MOISTURE AND COOLER AIR MAKES IT INTO THE EASTERN CWA WHERE I'LL KEEP A CHANCE OF SNOW AND COOLER TEMPS. AS YOU GO EAST TEMPS WILL BE SLIGHTLY WARMER WITH A LITTLE MORE SUN. NGM APPEARS TO BE RUSHING THINGS ABIT AS FAR AS TEMPS SO I'LL GO A BIT ABOVE OVER THE EAST AND MORE OVER THE CENTRAL AND WESTERN ZONES. IN THE EXTENDED...WILL AGAIN GO WITH THE MRF/NOGAPS SOLUTION. FORECAST AREA TO REMAIN IN NORTHWEST FLOW ALOFT WITH EMBEDDED VORT MAXIMA UNTIL WEDNESDAY WHEN SOME RIDGING AND WARMER 850 TEMPS ARE FORECAST. UNTIL THEN COLDER AIR WILL BACK INTO THE AREA WITH COLDEST TEMPS EAST AND WARMER TEMPS WEST. NOT A LOT OF SIGNIFICANT MOISTURE TO WORK WITH SO DRY LOOKS OK. .GLD...NONE THEDE ks