AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 824 PM EST SUN JAN 16 2000 MID CLOUDS MOVING SOUTH THROUGH GEORGIA ATTM. CLOUDS INTO NORTH CWA AND EXPECT THEM TO CONTINUE MOVING SOUTHWARD OVERNIGHT AND AFFECT REST OF CWA. LIGHT RAIN AND LOWERING OF VISIBILITIES MOSTLY NORTHEAST GA. FORECAST PACKAGE COVER GEORGIA CWA WITH INCREASING CLOUDS. WILL CHANGE THIS TO MOSTLY CLOUDY AND ADD INCREASING CLOUDS TO REST OF CWA FOR TONIGHT. MAY ADD ISOLATED POPS BUT WILL WAIT AND LOOK AT DATA RIGHT BEFORE SENDING OUT ZONES AND THEN DECIDE. RUC INDICATES MOISTURE/CLOUDS MOVING STEADILY SOUTHWARD AND WILL CONTINUE THIS TREND IN THE ZONES. DEWPOINTS IN THE 40S ACROSS THE BOARD AND OVERNIGHT LOWS LOOK GOOD. WINDS LIGHT....WITH A SHIFT ACROSS GEORGIA CWA TONIGHT...INTO FLORIDA BY MORNING. LOOKING AT THE COASTAL WATERS...WINDS AND SEAS NOT YET RESPONDING TO INCREASE AS DEPICTED BY MODELS. WILL CONTINUE THE INCREASING TREND THOUGH...AND KEEP SCEC UP FOR TONIGHT FOR GA WATERS. 11 .JAX... GA...NONE. FL...NONE. fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 850 PM CST SUN JAN 16 2000 SURFACE HIGH PRESSURE HOLDING TOUGH ACROSS THE WESTERN GREAT LAKES THIS EVENING. INFRARED IMAGERY SHOWING HIGH LEVEL MOISTURE ASSOCIATED WITH THE JET ACROSS NEBRASKA AND FAR SRN SD SINKING SLOWLY SOUTH WITH TIME WHILE OTHER BATCH PUSHING INTO WRN ND IS MOVING NE. THIS DOES NOT BODE WELL FOR DEVELOPING SNOW. IN FACT 00Z RUC NOT SHOWING ANY PRECIP AT ALL THROUGH 12Z WITH THE BEST DEEP LAYER MOISTURE AND CONVERGENCE/DIVERGENCE COUPLET OVER WI MONDAY MORNING. NO 00Z ETA TO VIEW BUT 18Z ETA WAS TRYING TO GEN UP SOME LIGHT SNOW IN EASTERN MN AFTER 09Z. WILL LEAVE THINGS ALONE FOR NOW BUT NOT TO CONFIDENT ON SNOW. MAY END UP BEING MORE OF A FREEZING DRIZZLE EVENT TOMORROW AS MID/HIGH LEVEL MOISTURE MAY BE MISSING WITH ABUNDANT LOW LEVEL MOISTURE AND SUPERCOOLED WATER DROPLETS. WILL ADJUST OVERNIGHT LOW TEMPERATURES WITH TEMPERATURES NOW STEADY OR SLOWLY RISING. WILL ALSO INDICATE CLOUDY SKIES. .MSP...NONE. HILTBRAND mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 1009 AM CST MON JAN 17 2000 SFC FRONT LOCATED FROM NEAR JOPLIN SE TO KIMBERLING CITY AREA. NORTH & E OF FRONT FOG/-RA/DZ WAS OCCURRING WITH TEMPS IN THE 30S/40S. S/SW OF FRONT TEMPS RISE INTO THE 50S WITH BREAKS IN THE OVERCAST. ALSO NO FOG/DZ/-RA WITH VISIBILITIES AROUND 7SM OR GREATER. LATEST RUC HAS SFC WNDS FROM SE/S DIRECTION THRU 18Z... WITH LAYER RH FIELDS SLOWLY DECREASING FROM W TO E. RADAR RETURNS STILL INDICATING -RA/DZ BUT BULK OF PRECIPITATION N/E OF FA. 12Z UPPER AIR ANALYSIS STILL INDICATING WAA THRU AFTN...WILL ADJUST TEMPS... ALONG WITH -RA/DZ CHANCES AS DEEPER MOISTURE REMAINING N/E OF FA. NO OTHER CHANGES FOR EXTENDED ATTM... BUT MAY ISSUE A SPS FOR WINTER PRECIPITATION CHANGES FOR FRI/FRI NIGHT. JLT mo AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1050 AM CST MON JAN 17 2000 MADE SOME RECENT CHANGES IN ZONES FOR WRN HALF OF THE CWA. MAINLY TO PLACE MORE CLD CVR TO TO THICK CIRRUS. HAVE ONLY HAD A CHC TO LOOK AT 12Z RUC/ETA THIS MRNG AND ONCE AGAIN VRY DISSAPPOINTED THAT THE DARN MDLS /EXCEPT NGM/ DO NOT EVEN KNOW THE HI CLDS ARE THERE. REGARDLESS...FCST SOUNDINGS SHOW QUITE A BIT OF WARM AIR ALF...BUT SOME DIFFICULTY IN ERODING SHALLOW COLD AIR. 16Z SFC ANLYS ALSO SHOWING WIND SHIFTS MUCH LATER THAN IN PRVS FCSTS. RECENT CALL FM LOCAL RADIO STATION IN SPENCER HAS INDICATED SOME SPOTTY REPORTS OF FREEZING DRIZZLE. WL HOLD OFF UPDATING ERN CWA TIL NOON TO LEAVE IN MENTION OF PCPN IN THE PKG FOR ANOTHER HOUR OR SO TO PLAY IT SAFE. ALSO WL NEED TO TAKE INTO THAT LACK OF FRONTAL PASSAGE MAY HAMPER EXPECTED HI TEMPS. .FSD...NONE BR sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 1100 AM CST MON JAN 17 2000 USUALLY A SNOW FCST GETS EASIER AS TIME GOES ON... THIS SYSTEM IS TRYING TO GET ITS ACT TOGETHER NOW THAT EVERYONE HAS GIVEN UP ON IT. STG UPPER DIVG IS COMBINING WITH INCREASING ISENT LIFT TO INCREASE SNOWFALL ACROSS NE MN...N WI AND THE WSTRN U.P. RADAR SHOWS THE EFFECT OF THIS LIFT...WITH WIDESPREAD 16-24 DBZ ECHOES ACROSS CNTRL/NE WI AND A DECREASE IN THE DRY AIR DONUT OVER GRB. IN GRB CWA...FULL SATURATION HAS ONLY OCCURRED OVER NC WI SO FAR...AND EGV/RHI HAVE ALREADY PICKED UP AN INCH. THE NEW ETA/RUC MODELS...WHICH SEEMED TO HAVE A GOOD HANDLE ON THE MOISTURE/LIFT (BUT NOT QPF) THIS MORNING... SHOW SATURATION OCCURRING ACROSS THE REST OF CNTRL/NE WI THIS AFTERNOON AS THE CORE OF STG DIVG MOVES THROUGH. EVEN AFTER THE UPPER DIVG MOVES THROUGH...ISENT LIFT IS FCST TO CONTINUE INTO THE EARLY EVG...WITH 30-35 KT WINDS BLOWING PERPENDICULAR TO THE 290K PRESSURE SFCS. ALSO...STILL CAN'T RULE OUT SOME LK-ENHANCEMENT FOR DOOR/KEW/MTW COUNTIES. WILL BE ISSUING AN UPDATED FCST BEFORE NOON...MAY NEED TO READJUST SNOWFALL AMOUNTS BACK UP A BIT...ESP IN NC WI. .GRB...NONE KIECKBUSCH WWW.CRH.NOAA.GOV/GRB wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 316 PM CST MON JAN 17 2000 MAIN FORECAST CHALLENGES ARE CLOUDS TONIGHT AND POPS IN LATER PERIODS. 12Z UA MAP ANALYSIS SHOWED MAIN ACTION STILL TO THE NORTH WHERE HEIGHT RISE/FALL/RISE TRIPLET WAS LOCATED IN PAC NW/NORTHERN PLAINS/NORTHEAST CONUS RESPECTIVELY FROM 500 MB DOWN AND LITTLE APPRECIABLE CHANGES ELSEWHERE. WARMEST AIR CONTINUES TO BE FOUND FROM DDC CWA SOUTH AND SOUTHWEST. 850 MB MOIST TONGUE WAS JUST EAST OF AREA WITH 30 TD DEPRESSION FROM DDC RAOB. LOW CLOUDINESS HAS ALL BUT ENDED OVER CWA AND TEMPS HAVE RECOVERED NICELY. 19Z SFC MAP PUT FRONTAL BOUNDARY FROM ROUGHLY CAO TO CDS TO JLN BUT 40+ F TDS LURK IN NORTHERN OKLAHOMA. NO CLEAR WINNER FOUND IN MODEL INITIALIZATION WITH ALL, AS EXPECTED, NOT HANDLING BOUNDARY LAYER MOISTURE WELL. FIRST CONCERN IS ANY RETURN OF LOW CLOUDS TONIGHT. SEE LITTLE CHANGE IN AIRMASS AND NEAR SATURATED CONDITIONS AGAIN SEEM POSSIBLE WITH LIGHT CAA. NGM AND ETA KEEP 925 MB RH LEVELS AT 50 AND 70 PERCENT THROUGH THE NIGHT WITH MESOETA AND RUC ONLY SLIGHTLY HIGHER THAN ETA. ISENTROPIC LIFT IS WEAKER THAN YESTERDAY AND GIVEN A LACK OF LOW CEILINGS ATTM, AS WAS SEEN YESTERDAY, AM NOT CONFIDENT IN RETURN OF LOW CLOUDS. CONSIDERABLE CIRRUS SHOULD CONTINUE OVERHEAD AND MOSTLY CLOUDY WORDING SHOULD HANDLE THINGS FAIRLY WELL IF SOME STRATUS DOES FORM. SWING SHIFT WILL HAVE TO MONITOR THIS CLOSELY. SOUTHERN STREAM ENERGY APPROACHES TUESDAY. SPEED OF VORT MAX AND LOCATION AND STRENGTH OF SFC LOW SPINUP IS IN QUESTION WITH FAST FLOW AND AFOREMENTIONED BOUNDARY LAYER DIFFICULTY. SEE NO REASON TO PULL SLIGHT POP GOING IN THE WEST AND WILL SHOTGUN SMALL POPS OVER ALL AREAS TUES NIGHT GIVEN THIS UNCERTAINTY. THINK WARMER TEMPS WILL BE REALIZED WEDNESDAY WITH LOWER TROPOSPHERIC MOISTURE, SOME DOWNSLOPE, AND SUBSIDENCE BEHIND WAVE. HAVE MOSTLY STUCK CLOSE TO FWC GUIDANCE WITH FAN BEING CONSISTENTLY TOO HIGH WITH TEMPS OVER THE PAST FEW DAYS. EXTENDED DISCUSSION... MRF AND CANADIAN SPECTRAL IN FAIR AGREEMENT THROUGH SATURDAY EVENING WHILE ECMWF IS A BIT SLOWER WITH ENERGY MOVING THROUGH THE SOUTHERN BRANCH OF THE WESTERLIES. ECMWF ALSO KEEPS THE SOUTHERN BRANCH TROF ABOUT 10 TO 15 DEGREES FARTHER WEST OVER THE EASTERN PACIFIC. ALL MODELS DO MAINTAIN THE SPLIT IN THE UPPER FLOW NEAR THE PACIFIC NORTHWEST COAST WITH NO MAJOR CHANGES IN THE GENERAL CIRCULATION PATTERN. TIMING OF WAVES THROUGH THIS REGIME WILL BE NEARLY IMPOSSIBLE AND CONFIDENCE REMAINS VERY LOW IN LATE PERIODS OF THE FORECAST. SURFACE LOWS FORECAST IN THE HIGH PLAINS REGION ON THURSDAY AND AGAIN ON MONDAY WILL LIKELY BE FARTHER SOUTH ALONG THE EDGE OF THE COLD AIR THAN ANY OF THE MODELS FORECAST. AS EACH OF THESE WAVES MOVES ACROSS THE CHANCE FOR CLOUD AND POSSIBLY EVEN SOME LIGHT DRIZZLE OR FOG IN UPSLOPE EXISTS BUT WITH TIMING OF THE WAVES IN SERIOUS DOUBT WILL NOT MAKE MAJOR CHANGES. SINCE CANADIAN AND MRF AGREE ON THE FIRST WAVE WILL GO AHEAD WITH SOME CLOUD AND MODERATED TEMPERATURES FOR THURSDAY NIGHT INTO FRIDAY BUT WILL NOT JUMP ON CHANCES FOR PRECIPITATION. PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE CONTAINED WITHIN THE DODGE CITY ZONE FORECAST. DDC 033/048 032/052 030 003 GCK 032/047 032/053 028 0-3 EHA 032/049 033/056 027 023 LBL 033/048 032/055 029 023 HYS 029/046 031/049 027 003 P28 035/049 034/052 033 003 .DDC...NONE. POAGE/JOHNSON ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 210 PM CST MON JAN 17 2000 FORECAST CONCERNS: -RA/FOG/DZ/CLDS EARLY...CLDS/TEMPS AND PRECIP CHC ON WED. -RA/DZ AND FOG PERSISTED THRU MOST OF THE DAY. BREAKS IN THE OVERCAST & S WNDS IN EXT SW MO CAUSED TEMPS TO RISE INTO THE 60S. LARGE TEMPS GRADIENT DEVELOP TDY OVR SW MO... WHERE TEMPS WERE 20 DEGREES DIFFERENT FROM PINEVILLE TO SPRINGFIELD MO. OVR AIZ/VIH TEMPS STILL WERE IN THE 30S. SHORT TERM MODELS ARE INDICATING MORE CLD CVR FOR TUE AS ANOTHER IN THE SERIES OF SHORT WAVES MOVES FROM S CA ACROSS THE ROCKIES INTO THE AREA BY TUE AFTN. IN THE SHORT TERM WILL NEED TO ADDRESS THE LATEST SAT LOOP TO SEE IF DRIER AIR WILL PUSH INTO SE KS OVERNIGHT. LATEST RUC SHOWING BULK OF THE DEEP MOISTURE MOVING TO THE E BY 00Z. HOWEVER WITH WEAK SFC WND FIELD OVERNIGHT AND ABUNDANT LOW LEVEL MOISTURE... BELIEVE FOG/OVERCAST SKIES WILL HOLD ON THRU TUE MORNING. BUT AS LOW CLDS/FOG AND DRIZZLE SLOWLY ERODE TUE MORNING...IT WILL BE FOLLOWED BY A PROGRESSIVE AMT OF MID/HIGH LEVEL MOISTURE. SO WORDING FOR TUE ZONES WILL BE MORNING FG/DZ WITH MOSTLY CLOUDY/PARTLY SUNNY THROUGH THE AFTN. N/NE WND FLOW WILL BECOME S/SE ON TUE NIGHT INTO WED IN RESPONSE TO NEXT SHORT WAVE ACROSS THE NORTHERN PLAINS. MODELS ARE INDICATING DEEPER MOISTURE ASSOCIATED WITH WED SYSTEM...ALONG WITH A STRONG WAA/ISENTROPIC LIFT PATTERN ACROSS FA. 1000/850H THICKNESS VALUES INDICATING A SHALLOW LAYER OF COLD AIR AT THE BEGINNING OF WED SYSTEM. NGM IS THE COOLEST WITH ETA THE WARMEST. HOWEVER CAN NOT RULE OUT A SHORT PERIOD OF FREEZING PRECIPITATION BEFORE THE WARMER AIR MOVES IN... ESPECIALLY IN N FA. A MUCH STRONGER SHORT WAVE & ASSOCIATED CLD FRONT WILL MOVE THRU WED NIGHT INTO THU. THICKNESSES DROP OFF RAPIDLY...PLUS 50-60 KTS AT THE 70/85H LEVEL. THIS MAY SET THE STAGE FOR FRI/FRI NIGHT SYSTEM WHICH MAY BE IN THE FORM OF SN. WILL WAIT AND SEE. EXTENDED PERIOD CONTINUES TO BECOME MORE INTERESTING. LONGER RANGE MODELS ARE NOW MORE IN LINE WITH YESTERDAYS MRF SOLUTION BRING A STRONGER SHORT WAVE TROF IN THE MID PART OF THE U.S. BY FRI. THERE ARE SOME DIFFERENCES IN THE SFC FRONT/LOW AND STRENGTH OF THE SYSTEM...HOWEVER THE MAIN UPPER LEVEL PATTERN DOES CHANGE AS THE MAIN JET MOVES FURTHER SOUTH ACROSS THE CENTRAL PART OF THE COUNTY. WILL LEAN TOWARD THE FASTER/PROGRESSIVE MRF SOLUTION THIS PACKAGE. WITH THIS IN MIND WILL CONTINUE THE TREND OF LIGHT PRECIPITATION ON FRI...WITH MUCH COLDER CONDITIONS ON SAT. BY THE BEGINNING OF NEXT WEEK...A LONG POSITIVE TILTED TROF DEVELOPS ACROSS THE CENTRAL U.S. WHICH WILL GIVE AN EVEN BETTER CHANCE OF PRECIPITATION BY MON/TUE/WED. PRELIM CCF NUMBERS ARE FOR COORDINATION ONLY... SGF EC 038/048 028/048 022 251--2 JLN EC 035/050 031/051 024 25---3 UNO EC 032/050 027/048 025 252--2 VIH EC 034/042 025/047 019 253--2 .SGF...NONE. JLT mo