AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 1247 PM CDT SAT APR 12 2003 AVIATION DISCUSSION FOR 18Z TAFS EXTENSIVE AREA OF LOW CLOUDS ACROSS NORTH WI AND NORTHERN MI MADE PUSH SOUTH HAS NOW ERODED OVER MOST AREAS ACCEPT ALONG THE WESTERN SHORE OF LAKE MI WHERE NE FLOW BRINGING THE COOLEST AIR. HOWEVER EVEN ACROSS NE WI CIGS HAVE RISEN TO 2-3KFT AND AREA CONTINUES TO DIMINISH EARLY THIS PM. ANOTHER AREA OF LOW MVFR CIGS FORMED RIGHT ALONG SOUTHERN SHORE OF LAKE MI FROM GARY EAST WITH A COUPLE AREAS OF STRATOCU PUSHING DOWN THE LAKE. HAVE GONE WITH SCATTERED CLOUDS FOR TERMINALS CLOSEST TO LAKE MI WITH POSSIBLY SOME MVFR CIGS THIS PM AND WILL KEEP SCATTERED CLOUDS IN THIS EVENING BUT NOT EXPECTING ANY PROLONGED CIGS AFTER THIS AFTERNOON. NE WINDS STAY GUSTY TO 20KTS THIS AFTERNOON THEN QUICKLY DROP OFF AFTER SUNSET AND SHIFT LIGHT EASTERLY OVERNIGHT THEN SOUTHEAST BY MORNING. CMS DISCUSSION FOR 1000 AM ZONE UPDATE WEAK COLD FRONT PASSED SOUTH OVERNIGHT AS PROGGED...BUT DIDNT EXPECT TEMPS IN SUBURBS TO BE SO WARM AT THIS POINT. SYNOPTIC N/NE FLOW OFF LAKE REALLY DIDNT START UNTIL 3 AM OR SO. THE DEEPER COLD/DRY AIR IS STILL LOCATED ON THE NORTH HALF OF LAKE MICHIGAN. THIS CORRESPONDS WELL WITH AN APPROACHING STRATO CU CLOUD DECK AT 2 KFT. LINEAR EXTRAPOLATION BRINGS THE FRONT EDGE INTO THE NORTHERN SUBURBS AROUND 20Z (300 PM). HOWEVER...WITH APRIL SUN...AND WEAKER CAA FURTHER SOUTH FROM THE HIGH CENTER...AM INCLINED TO BRING THE CLOUD DECK IN LATE THIS AFTERNOON ACROSS NORTHERN ILLINOIS...AND THIS EVENING FURTHER SOUTH. ON THE SHORTER TERM...POST FRONTAL FLOW OFF THE 40 DEGREE LAKE WILL KEEP TEMPS DOWN WELL INLAND. RUC THETAE CROSS SECTION SHOWS MIXING HEIGHTS START ELEVATING ABOVE MARINE LAYER ABOUT 20 MILES SW OF OHARE. WILL HOLD METRO AREA TEMPS DOWN...WITH CURRENT DOWNTOWN TEMPS IN THE MID TO UPPER 30S AND LOWER 50S WELL INLAND NEAR JOLIET. UPDATE WILL REFLECT INCOMING STRATO CU DECK LATE THIS AFTERNOON INTO TONIGHT...AND A STRONGER TEMPERATURE GRADIENT FURTHER FROM THE LAKE THIS AFTERNOON. .CHI....SMALL CRAFT ADVISORY FOR NEARSHORE WATERS ON LAKE MICHIGAN TODAY. ROGOWSKI il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 930 AM CDT SAT APR 12 2003 DISCUSSION FOR 1000 AM ZONE UPDATE WEAK COLD FRONT PASSED SOUTH OVERNIGHT AS PROGGED...BUT DIDNT EXPECT TEMPS IN SUBURBS TO BE SO WARM AT THIS POINT. SYNOPTIC N/NE FLOW OFF LAKE REALLY DIDNT START UNTIL 3 AM OR SO. THE DEEPER COLD/DRY AIR IS STILL LOCATED ON THE NORTH HALF OF LAKE MICHIGAN. THIS CORRESPONDS WELL WITH AN APPROACHING STRATO CU CLOUD DECK AT 2 KFT. LINEAR EXTRAPOLATION BRINGS THE FRONT EDGE INTO THE NORTHERN SUBURBS AROUND 20Z (300 PM). HOWEVER...WITH APRIL SUN...AND WEAKER CAA FURTHER SOUTH FROM THE HIGH CENTER...AM INCLINED TO BRING THE CLOUD DECK IN LATE THIS AFTERNOON ACROSS NORTHERN ILLINOIS...AND THIS EVENING FURTHER SOUTH. ON THE SHORTER TERM...POST FRONTAL FLOW OFF THE 40 DEGREE LAKE WILL KEEP TEMPS DOWN WELL INLAND. RUC THETAE CROSS SECTION SHOWS MIXING HEIGHTS START ELEVATING ABOVE MARINE LAYER ABOUT 20 MILES SW OF OHARE. WILL HOLD METRO AREA TEMPS DOWN...WITH CURRENT DOWNTOWN TEMPS IN THE MID TO UPPER 30S AND LOWER 50S WELL INLAND NEAR JOLIET. UPDATE WILL REFLECT INCOMING STRATO CU DECK LATE THIS AFTERNOON INTO TONIGHT...AND A STRONGER TEMPERATURE GRADIENT FURTHER FROM THE LAKE THIS AFTERNOON. .CHI....SMALL CRAFT ADVISORY FOR NEARSHORE WATERS ON LAKE MICHIGAN TODAY. ROGOWSKI AVIATION DISCUSSION FOR 12Z TAFS ANOTHER DAY OF WINDS OFF LAKE. SHOULD SEE SOME GUSTS MIDDAY WITH GOOD MIXING. WINDS THEN DIE THIS EVE AND GO VRB BEFORE MIDNIGHT AS RIDGE MOVES TO E. ONLY REAL Q IS THE CLOUD DECK COMING DOWN INTO N WI. MODLES SHOW INCREASE IN LOWEST RH 03-06Z. WOULD THINK IF THEY GET HERE WILL BE BEFORE THAT...BY LATE AFTERNOON. RIGHT NOW FIGURING LOT OF SUN AND LOW DEW POINTS WILL SCATTER CLOUDS BEFORE DECK GETS DOWN HERE SO JUST SCT CU IN FORECAST FOR EVE/TONIGHT. WINDS OVERNIGHT ALOFT GO E THEN SE SO NO LONGER FAVORABLE TO MAINTAIN THEM LATER TONIGHT. AL il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 810 PM MDT SAT APR 12 2003 QUICK UPDATE TO THE AFTERNOON PACKAGE...BASICALLY FOR WINDS AND CLOUDS. AT 02Z LATEST SATELLITE PICS SHOW PLENTY OF MID AND HIGH LEVEL CLOUDS STREAMING INTO THE AREA AHEAD OF LARGE UPPER LOW OFF THE WEST COAST. MODELS IN FAIR CONSISTENCY BRINGING THESE CLOUDS ACROSS THE AREA FOR THE REMAINDER OF THE 1ST PERIOD WITH SOME CLEARING OVER OUR COLORADO COUNTIES BY SUNDAY MORNING. USED THE NGM GRIDS TO ILLUSTRATE THIS POINT. BORDERLINE BREEZY CONDITIONS EXIST NEAR THE COLORADO AND KANSAS STATE LINE WITH LESSER WINDS TO THE EAST. LATEST GUIDANCE AND 00Z RUC SHOW THIS WELL SO AM GONNA KEEP BREEZY CONDITIONS OVER THE WESTERN HALF OF THE FORECAST AREA AND REMOVE THEM OVER THE EASTERN HALF. OTHERWISE...DIURNAL TEMP TOOL WORKING WELL AT PRESENT TIME SO NO NEED TO ADJUST TEMP/DEWPOINT GRIDS AT THIS TIME. DDT PREVIOUS DISCUSSION BELOW --------------------------------------------------------------------- CHALLENGES ARE TEMPERATURES THROUGH THE PERIOD AND CHANCES FOR THUNDERSTORMS LATE TUE. BREEZY CONDITIONS OVER THE TRI STATE AREA TODAY WITH LOTS OF SUN. LEE TROUGH HAS DEEPENED SLIGHTLY CAUSING SOUTH WINDS TO BE NEAR WINDY CONDITION IN USUAL PLACES ALONG THE COLORADO AND KANSAS BORDER. THE UPPER RIDGE AXIS ALSO NEAR THE SAME BORDER KEEPING CLOUDS AT A MINIMUM AND STABILITY AT A MAXIMUM. RECORD HIGHS AT GLD AND YMA HAVE ALREADY BEEN TIED. NOT MUCH DIFFERENCE BETWEEN MODELS IN THE CENTRAL PART OF THE COUNTRY WITH THE BIG UPPER RIDGE EASILY BEING THE DOMINANT FEATURE. WILL GO WITH A MIX OF AVN AND ETA. TONIGHT UPPER RIDGE CONTINUES SLOW MOVEMENT TO THE EAST. HOWEVER IT IS FLATTENED SLIGHTLY AS MODELS SHOW A MID LEVEL SHORTWAVE PASSING OVERHEAD THROUGH IT. MODERATE MID LEVEL OMEGA (POSITIVE UPWARD MOTION FIELD) AND ASSOCIATED CLOUDINESS MOVES STEADILY ACROSS MY CWA DURING THE NIGHT. ONE AFFECT IS TO KEEP BRISK SOUTH WINDS AHEAD OF THE TROUGH BEFORE SHIFTING TO THE WEST AND DECREASING BEHIND IT. IT IS TOO DRY IN THE LOW LEVELS TO SEE ANY MOISTURE AT THE GROUND...BUT MID LEVEL VIRGA IS POSSIBLE FROM THIS WEAK UNSTABLE ELEMENT. NEAR GUIDANCE LOWS LOOK REASONABLE...BUT ISOLATED AREAS WILL LIKELY DROP BRIEFLY BELOW AS THE WINDS DROP AND SKIES CLEAR NEAR DAWN. SUN THE UPPER RIDGE CONTINUES TO DOMINATE WITH LOTS OF SUNSHINE. 850MB TEMPERATURES RISE 4-5 DEGREES AND SUPPORT SURFACE TEMPERATURES ABOUT 5-8 DEGREES HIGHER THAN TODAY. THAT WOULD PUSH MANY TOWARD THE RECORD LEVEL WITH MOST RECORDS IN THE MIDDLE 80S (EXCEPT MCK WITH 92). WILL GO WITH RECORD/NEAR RECORD WORDING MOST AREAS. SUN NIGHT UPPER HEIGHTS FALL SLIGHTLY AS RIDGE MOVES ON. HOWEVER MODELS SHOW ANOTHER LLJ BREEZY NIGHT SIMILAR TO TONIGHT. FEWER CLOUDS THAN TONIGHT WHICH SHOULD OFFSET THE SLIGHTLY HIGHER DAYTIME TEMPERATURES. RESULT...LOWS CLOSE TO TONIGHTS. MON LOOKS TO POSSIBLY BE EVEN SLIGHTLY WARMER THAN SUN WITH AGAIN FEW CLOUDS...A SLIGHT RISE IN 850MB TEMPERATURES SUPPORTING HIGHS IN THE UPPER 80S TO NEAR 90...AND LIGHTER WINDS. WILL AGAIN GO WITH RECORD/NEAR RECORD WORDING. AFTER ANOTHER MILD NIGHT MON NIGHT CLOUDS INCREASE ON TUE IN ADVANCE OF A COLD FRONT AND APPROACHING DEEPENING SHORTWAVE FROM THE WEST. WILL LEAVE CHANCE OF THUNDERSTORMS LATE TUE INTO EARLY WED AS UPPER SYSTEM SEEMS TO DEEPEN AS IT PASSES TO EAST ACROSS NEB. LOOKS TO BE A WINDY NIGHT AND MUCH COOLER ON WED. MODELS IMPLYING A DRY SLOT LATE TUE IS POSSIBLE...WHICH WILL HAVE TO BE WATCHED CLOSELY BECAUSE OF ITS OBVIOUS AFFECT ON PRECIPITATION CHANCES. ANOTHER UPPER RIDGE PROGRESSES STEADILY ACROSS THE AREA WED INTO FRI BRINGING A RETURN TO DRY AND WARMER WEATHER...BUT ONLY SLIGHTLY ABOVE NORMAL. THEN FRI EXTENDED MODELS CONTINUE (AS PER SUCCESSIVE RUNS) TO SHOW AN EVER STRENGTHENING...ALBEIT SLOWING...UPPER SYSTEM APPROACHING FROM THE WEST COAST. MODELS NOW SHOWING SYSTEM MOVING ACROSS KS ON SAT. LOTS OF MOIST AIR AND DROPPING THICKNESSES. FOR NOW WILL INDICATE COOLING AND MOISTENING TREND FOR FRI AND SAT. CURRENT TRACK WOULD MAKE GENERAL RAIN (POSSIBLY MIXED WITH SNOW IN HIGHER ELEVATIONS) A REASONABLE POSSIBILITY WITH THIS SYSTEM AS IT PASSES ACROSS THE CENTRAL PLAINS OVER THE WEEKEND. .GLD...NONE. $$ RJC ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1108 PM EDT SAT APR 12 2003 WV IMAGERY/RUC ANALYSIS SHOWS SHRTWV OVR MANITOBA RIDING OVR CNTRL CONUS UPR RDG. WAA/295-300K ISENTROPIC LIFT AHD OF SHRTWV PRODUCING CLDS AND SOME SCT SHOWERS OVR WRN ONTARIO...PER IR SATL IMAGERY AND SFC OBS. 00Z ETA INDICATES LOWEST CONDENSATION PRES DEFICITS OF 20 MB OR LESS TO STAY OVR NRN LAKE SUPERIOR AND ONTARIO OVRNGT...SO WOULD EXPECT U.P TO STAY DRY PER GOING FCST. LOOK LIKE SOME MID CLDS WILL SPREAD OVR NRN COUNTIES OVRNGT...BUT THIS ALSO COVERED FM PREV FCST. MIN TEMPS IN THE UPPER TEENS TO AROUND 20 STILL LOOK ON TARGET BASED ON LATEST SFC OBS AND DWPNT READINGS. GOING FCST LOOK GOOD FOR TEMPS AND CLDS SO NO UPDATES NEEDED AT THIS TIME. .MQT...NONE. VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 348 PM EDT SAT APR 12 2003 WIDE TEMP SWINGS COMING UP IN THE NEXT WEEK WITH SUMMER WARMTH/RECORD HIGHS MON THEN PROBABLY SNOW BY WED NIGHT. WV IMAGERY/RUC ANALYSIS SHOW A CLOSED MID/UPPER LOW JUST OFF W COAST. DOWNSTREAM...PRONOUNCED RIDGE IS EVIDENT FROM WRN PLAINS TO SCNTRL CANADA WITH A SHORTWAVE NOTED NEAR RIDGE AXIS OVER SASKATCHEWAN. RIDGE IS SUPPORTING A SFC HIGH OVER NRN ONTARIO. LOW CLOUDS THAT DEVELOPED/MOVED INTO UPPER MI LAST NIGHT ON NERLY FLOW HAVE BEEN SLOWLY MIXING OUT WITH APRIL SUN THIS AFTN. OTHERWISE... CLEAR SKIES ARE NOTED OVER MOST OF THE NRN PLAINS/MIDWEST. A GENERALLY DRY PERIOD EXPECTED THRU MON WITH ONLY MINOR PCPN CONCERNS COMING LATE TONIGHT/SUN ASSOCIATED WITH AFOREMENTIONED SHORTWAVE AND SUN NIGHT IN ASSOCIATION WITH LOW-LEVEL JET AND IMPRESSIVE WARM AIR SURGE. AS SASKATCHEWAN SHORTWAVE MOVES TO ONTARIO BY 12Z SUN...WAA/ISENTROPIC ASCENT DEVELOP. MODELS SHOW BEST ASCENT/LOWEST CONDENSATION PRES DEFICITS (295/300K SFCS) PASSING JUST N OF LAKE...IN LINE WITH MODEL PCPN PROGS. ALTHOUGH ASCENT PASSES OVER FCST AREA...CONDENSATION PRES DEFICITS LOOK PROHIBITIVELY HIGH FOR PCPN. IN ADDITION...LINGERING DRY LAYER CENTERED AROUND 4KFT (DWPT DEPRESSIONS OF 15-20C PER ETA) SHOULD BE SUFFICIENT TO PREVENT ANY PCPN WHICH MAY DEVELOP FROM MID CLOUD DECK. EXPECT NOTHING MORE THAN SOME MID CLOUDS SPREADING OVER AREA LATER IN THE NIGHT. GOING MIN TEMPS LOOK ON TRACK WITH COOLEST READINGS (AROUND 20) CNTRL/E WHERE SFC RIDGE WILL BE PASSING DURING THE NIGHT WHILE LIGHT RETURN FLOW DEVELOPS W. WAA CONTINUES SUN. AGAIN EXPECT ANY PCPN TO REMAIN N/NE OF FCST AREA WHERE BEST ASCENT/LOWEST CONDENSATION PRES DEFICITS REMAIN. IN ADDITION...DRY LAYER REMAINS IN PLACE AROUND 4KFT HERE. END RESULT WILL PROBABLY BE A SCT-BKN AC DECK THRU THE DAY. COOLER GFS MOS LOOKS MORE REASONABLE THAN ETA MOS AS SSE SFC FLOW AHEAD OF APPROACHING WARM FRONT NOT BEST FOR A STRONG WARMUP. OF COURSE...LK MICHIGAN SHORELINE AREAS...ESPECIALLY KESC EWD WILL BE STRONGLY INFLUENCED BY CHILLY LK MICHIGAN MARINE LAYER. TEMPS SHOULD STAY IN THE 30S RIGHT ALONG SHORELINE THERE. KEWEENAW WILL ALSO BE COOLED BY ESE FLOW ACROSS SCNTRL LK SUPERIOR. SUN NIGHT...LOW-LEVEL JET SLIDES ACROSS UPPER MI. SPEED RANGES FROM 40KTS ON NGM TO 50KTS ON GFS AND 60KTS ON ETA. REALITY WILL PROBABLY BE SOMEWHERE IN THE MIDDLE AROUND 50KTS. IN ANY CASE...JET MOVES UNDERNEATH VERY STEEP MIDLEVEL (700-500MB) LAPSE RATES OF 8-9C/KM. WOULD SEEM TO BE A GOOD SETUP FOR SCT TSRA...BUT LOW-LEVEL MOISTURE WILL STILL BE A LIMITING FACTOR PER RH CROSS SECTIONS. NONETHELESS...LOW-LEVEL JET AND STEEP MIDLEVEL LAPSE RATES IN COMBINATION WITH WARM FRONT LIFTING THRU THE AREA ARGUE FOR CHC POPS PER GOING FCST. SUMMER LIKE DAY EXPECTED MON AS WARM FRONT LIFTS N OF THE AREA BY MORNING. IDEAL STRONG SW/WSW FLOW OF WARM/DRY AIR ORIGINATING FROM WRN PLAINS/LEE OF THE ROCKIES SETS THE STAGE FOR RECORD WARMTH SIMILAR TO WHAT OCCURRED ALMOST EXACTLY ONE YEAR AGO TO THE DATE. WHO CAN FORGET THE HIGHS IN THE 70S/80S WITH 1-2FEET OF SNOW ON THE GROUND LAST MID APRIL. THERMAL RIDGE MOVES INTO UPPER MI AHEAD APPROACHING TROF MON. ETA SHOWS 850MB TEMPS AS HIGH AS 19C WHILE GFS ONLY AROUND 14C. THIS TRANSLATES TO HIGHS ROUGHLY MID 70S (GFS) TO LOWER 80S (ETA). INCLINED TO GO TOWARD WARMER SOLUTION GIVEN IDEAL SETUP FOR WARMTH AND SOURCE REGION OF AIRMASS. VERY DEEP MIXED LAYER AND ARRIVAL OF VERY DRY AIR AROUND 850MB FROM THE WRN PLAINS SHOULD RESULT IN SFC DWPTS/RH CRASHING DURING THE DAY...RAISING POTENTIAL FIRE WX CONCERNS. MODEL GUIDANCE LIKELY MISSING THIS. COLD FRONT DRIFTS S THRU THE AREA TUE/TUE NIGHT...BRINGING AN ABRUPT END TO WARMTH. HAVE GONE WITH CONSENSUS SLIGHTLY SLOWER CANADIAN/GFS/UKMET SOLUTION OF FRONTAL PASSAGE AS OPPOSED TO ETA MON NIGHT SOLUTION. EXPECT INCREASING RAIN THREAT AS BAROCLINIC ZONE TIGHTENS OVER THE AREA TUE/TUE NIGHT. WED-SAT...GFS/CANADIAN/UKMET/ECWMF CONTINUE TO DISAGREE ON EVOLUTION AND TIMING OF SYSTEM EJECTING FROM SW CONUS INTO LAKES MIDWEEK. GFS OVER THE LAST FEW RUNS HAS TRENDED S TOWARD UKMET/CANADIAN/ECMWF SOLUTIONS. THIS SWD TREND A RESULT OF A STRONGER NRN STREAM SHORTWAVE DIGGING THRU SE CANADA...REMINISCENT OF THE VERY COLD MID/LATE WINTER PATTERN THAT DOMINATED THE AREA. IN ANY CASE... QUESTIONS ARE WHETHER THE NRN STREAM WILL BE STRONG ENOUGH TO SUPPRESS SRN STREAM SHORTWAVE WELL S OF THE FCST AREA...AND IF NOT...IS ANOTHER ACCUMULATING SNOW IN THE CARDS. 00Z GFS ENSEMBLES ARE VERY SUPPORTIVE OF THE OPNL RUN AND THE SIGNIFICANT PCPN THAT IT DEPICTS WED. OTHER MODELS ARE 12-24HRS SLOWER IN THE EVOLUTION...BUT ECMWF ALSO SUPPORTS A SIGNFICANT PCPN EVENT AS NEGATIVE TILT SHORTWAVE LIFTS INTO LAKES THU. UKMET IS FARTHEST S...SUGGESTING A MUCH LIGHTER PCPN EVENT. HARD TO IGNORE ENSEMBLE SUPPORT FOR OPNL GFS RUN...BUT IT HAS BEEN TRENDING TOWARD THE OTHER SOLUTIONS WHICH TODAY ARE ALL SLOWER THAN THE GFS. INCLINED TO LEAN TOWARD A SLOWER THAN GFS SOLUTION (TOWARD ECMWF) GIVEN ITS TREND. SO...AN INCREASINGLY COLD LOW-LEVEL NE FLOW LOCKS IN WED AS HIGH BUILDS TO THE N IN THE WAKE OF NRN STREAM SHORTWAVE IN SE CANADA...RESULTING IN TIGHT BAROCLINIC ZONE SETTING UP OVER NWRN LAKES REGION. GOING FCST OF RAIN LIKELY WED ON TRACK. DIFFICULT TO ASSESS SNOW POTENTIAL GIVEN SIGNIFICANT MODEL DISAGREEMENTS...BUT POTENTIAL THERE FOR A SWITCH TO SNOW (POSSIBLY SIGNIFICANT GIVEN MOISTURE AVAILABILITY) AT SOME POINT WED INTO THU. RAIN/SNOW WILL WIND DOWN ON THU...AND MAY LINGER INTO FRI AS UPPER TROF IS SLOW TO LIFT OUT PER ECWMF. DRY SAT EXPECTED. .MQT...NONE. ROLFSON mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1135 AM EDT SAT APR 12 2003 SOME THIN CS OVER LOWER MICHIGAN THIS MORNING WITH CU STARTING TO DEVELOP ACROSS THE THUMB. EXPECT THIS CU TO CONTINUE TO DEVELOP ACROSS THE REST OF THE CWA. HOWEVER...DECENT NNE WINDS WILL PUSH LAKE AIR A GOOD WAY ACROSS THE THUMB. THE END RESULT WILL BE PARTLY SUNNY SKIES THIS AFTERNOON RATHER THAN MOSTLY CLOUDY...BUT THERE COULD STILL BE A TWO HOUR PERIOD WHERE THE CU BECOMES MOSTLY CLOUDY BEFORE DIMINISHING AS MIXING GETS DEEPER AND THE STABLE LAKE AIR MOVES IN. RUC 925 MOISTURE IS MUCH LESS THAN 06Z OR 00Z RUNS OF ETA/GFS. THIS IS CONFIRMED BY THE LOW CLOUDS ACROSS THE UP AND ONTARIO DISSIPATING AS THEY TRIED TO MOVE INTO NORTHERN LOWER. WITH A TOUCH MORE SUNSHINE AND CURRENT TEMPS RUNNING A COUPLE OF DEGREE WARMER THAN GUIDANCE AT 15Z...WILL RAISE TEMPS JUST A BIT ACROSS THE ENTIRE CWA. WILL ALSO BUMP UP THE WINDS IN THE GRIDS...BUT THEY WILL STILL BE IN THAT 10 TO 20 MPH RANGE FOR THE FORECAST TEXT. ACTUALLY WINDS FOR A TIME MAY BE IN THE HIGHER END OF THAT RANGE...ESPECIALLY NEAR LAKE HURON. ...PREVIOUS FORECAST DISCUSSION... 00Z RAOBS/WATER VAPOR LOOP SHOW UPPER LOW ALONG THE MID ATLANTIC COAST...WITH AMPLIFIED RIDGE ACROSS THE CENTRAL CONUS. WEAK SHORTWAVE OVER SOUTHEAST MICHIGAN WITH ANOTHER BACK ACROSS MINNESOTA. SURFACE ANALYSIS SHOWS HIGH NEAR HUDSON BAY WITH RIDGE INTO THE UPPER MISSISSIPPI VALLEY. WEAK AND DRY COLD FRONT JUST CLEARING THE CWA...WITH ONLY SOME PATCHY CIRRUS ACROSS SOUTHWEST LOWER APPARENT ON SATELLITE. FARTHER UPSTREAM THOUGH LOW CLOUDS ACROSS NORTHERN ONTARIO ARE SPREADING SOUTHWARD ACROSS UPPER MICHIGAN. DRY PATTERN CONTINUES WITH TEMPERATURES AND CLOUDS THE MAIN CONCERN FOR THE WEEKEND. ETA/GFS SIMILAR WITH OVERALL FEATURES...ALTHOUGH BOTH STILL INITIALIZED A BIT TOO WARM ACROSS NORTHERN LOWER /READ THEY WERE TOO SLOW WITH THE COLD ADVECTION BEHIND THE COLD FRONT/. THE GFS INITIALIZED CLOSER THAN ETA THERMALLY AGAIN. UNDER THERMAL RIDGE WITH FULL SUN YESTERDAY...TEMPERATURES CLIMBED NEAR 70F. 850MB TEMPERATURES DROP ABOUT 8C BY THIS EVENING /PER THE GFS...WHICH WAS 1C COOLER THAN THE ETA/ WHICH WOULD ARGUE FOR HIGHS IN THE LOWER/MID 50S. HOWEVER WITH ADDITIONAL CLOUD COVER WILL NEED TO CUT THAT EXPECTATION BACK A BIT MORE. WIDESPREAD MVFR CLOUDS OBSERVED ACROSS NORTHERN ONTARIO IN THERMAL TROUGH...WITH AREA OF 925MB RH >90 PERCENT. CU SCHEME /850MB TEMP MINUS 100MB DEWPOINT/ DELINEATES THESE CLOUDS PRETTY WELL. FORECAST SOUNDINGS SHOW RATHER DRY AIR ABOVE THE INVERSION AS WELL...WITH DEWPOINT DEPRESSIONS UP TO 20C ABOVE 800MB. ETA HINTS AT TAPPING INTO THIS DRIER AIR...AS IT DIMINISHES LOW-LEVEL MOISTURE DURING THE DAY. THIS IS SIMILAR TO WHAT HAPPENED YESTERDAY ACROSS NORTHERN ONTARIO...AS CLOUD SHIELD SLOWLY ERODED/SHRANK WITH MIXING DURING THE DAY. OVERNIGHT IT HAS BEEN REEXPANDING AS IT PUSHES SOUTH INTO THE NORTHERN GREAT LAKES. EXPECT WE WILL SEE A PERIOD OF CLOUDS /AT LEAST A FEW HOURS/ BUT NOT SURE IF THAT WOULD GO BEYOND A PARTLY CLOUDY IDEA. WILL STICK WITH CURRENT FORECAST OF MOSTLY CLOUDY...ALTHOUGH FOR A SHORTER DURATION. TIMING OF THE CLOUDS INTO THE CWA IS ALSO SLOWER...BASED ON A LINEAR EXTRAPOLATION OF THE LEADING EDGE WHICH SUPPORTS A LATER ETA TIMING. TEMPERATURES ACROSS THE CWA ARE STILL IN THE 40S FOR THE MOST PART...AND EXPECT THEM TO DIP INTO THE UPPER 30S BY SUNRISE. WITH A LITTLE ADDITIONAL INSOLATION AND STATIONS STARTING OUT WARMER THAN BEFORE...WILL ADD A DEGREE OR TWO ON TO THE HIGHS FOR TODAY. DECENT NORTHERLY FLOW WILL KEEP THE THUMB FROM WARMING VERY MUCH THOUGH. LOW LEVEL MOISTURE SCOURS OUT DURING THE LATE AFTERNOON/EVENING NORTH TO SOUTH ACROSS THE CWA. ETA/GFS TRY TO BRING SOME MID/UPPER LEVEL MOISTURE INTO THE STATE LATE TONIGHT. CURRENTLY THIS IS SEEN IN CLOUDS NEAR LAKE WINNIPEG WESTWARD. MORE SCATTERED AREAS OF CLOUDS TO THE SOUTH ACROSS THE PLAINS. WITH UPPER RIDGE AXIS SHIFTING EASTWARD...DO NOT SEE THE MAIN CLOUDS NEAR LAKE WINNIPEG TRACKING FAR ENOUGH SOUTH TO AFFECT THE CWA. WOULD ONLY EXPECT SCATTERED CLOUDS...AS WELL AS A LARGER PERIOD OF CLEAR SKIES LATE EVENING/EARLY OVERNIGHT. WILL FOLLOW A MORE OPTIMISTIC MOSTLY CLEAR/BECOMING MOSTLY CLEAR FOR TONIGHT. RIDGE AXIS MOVES OVERHEAD BY 12Z SUNDAY AS WELL...WITH A RATHER LIGHT WIND FIELD. 850MB TEMPERATURES START TO CLIMB OVERNIGHT...BUT NOT FROM WARM ADVECTION...JUST A SINKING INVERSION HEIGHT. EXPECT TEMPERATURES TO QUICKLY RADIATE DOWN INTO THE 20S. WITH FEWER CLOUDS EXPECTED...WILL DROP LOWS A COUPLE DEGREES. RIDGE SHIFTS EAST ON SUNDAY...WITH RETURN FLOW DEVELOPING BEHIND IT. WILL STICK WITH THE ETA IDEA OF HOLDING ON TO MORE OF A SOUTHEASTERLY FLOW SUNDAY/SUNDAY NIGHT...WHEREAS THE GFS BRINGS WINDS AROUND TO THE SOUTHWEST FASTER. THIS WILL KEEP THE EASTERN CWA AND ESPECIALLY THE THUMB LIGHTLY COOLER DUE TO LAKE INFLUENCES. FORECAST SOUNDINGS DO SHOW SOME WARMING THROUGH THE COLUMN...WITH INVERSIONS NEAR 900MB AND TEMPS THERE CLIMBING TO NEAR 3C/4C. ENOUGH MID/HIGH CLOUDS ACROSS THE NORTHERN CWA TO KEEP A MENTION OF PARTLY SUNNY...BUT IT LOOKS PRIMARILY MOSTLY SUNNY FARTHER SOUTH. WARM ADVECTION REALLY KICKS IN IN EARNEST SUNDAY NIGHT INTO MONDAY...WITH 850MB TEMPERATURES CLIMBING TO 12C/14C IN THE ETA/GFS BY 00Z TUESDAY. STRONG THETA-E ADVECTION OVERNIGHT SUNDAY INTO MONDAY...WITH GOOD MOISTURE CONVERGENCE/ISENTROPIC LIFT. SOME INSTABILITY BY MONDAY WITH A FEW HUNDRED J/KG OF CAPE AND LIS DOWN TO -2C OFF A MODIFIED SOUNDING...BUT WILL A PRETTY STRONG CAP IN PLACE. AIRMASS IS RATHER DRY TO BEGIN WITH...AND IT IS HARD TO SEE US GETTING MUCH BEYOND PARTLY CLOUDY SKIES. SOUTHEAST MICHIGAN REMAINS WELL INTO THE WARM SECTOR THROUGH MID WEEK...WITH A DECENT STRETCH OF ABOVE NORMAL TEMPERATURES. .DTX...NONE. $$ BRAVENDER EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1030 AM EDT SAT APR 12 2003 LOW LEVEL MOISTURE OVER SOUTHERN ONTARIO MAKING SLOW PROGRESS SOUTHWARD. MOISTURE AND LIGHT PRECIP ASSOCIATED WITH UPPER LEVEL CYCLONIC FLOW AND SHORT WAVE ENERGY. BASED ON SATELLITE TRENDS AND AND 06Z ETA/RUC WILL MAKE AFTERNOON FORECAST MORE OPTIMISTIC. WILL CONTINUE WITH LOW CHC POPS LATE DAY NRN ZONES BUT REMOVE THEM ELSEWHERE. BASED ON CURRENT TRENDS LOW LEVEL MOISTURE WON'T REACH THE CENTRAL ZONES UNTIL LATE DAY. WITH NORTHWEST FLOW AND WEAK CCA TWEAKED TEMPS DOWN SLIGHTLY. RRM ...PREVIOUS AFD... TONIGHT..THE WEAK SHORTWAVE WILL MOVE THROUGH...WITH SKIES CLEARING ACROSS NRN/CENTRAL ZONES AFTER MIDNIGHT. WILL KEEP A CHANCE OF SPRINKLES FOR ALL ZONES. SUNDAY..HIGH PRESSURE WILL MOVE OVER THE AREA WITH TEMPS A FEW DEGS COOLER THAN SATURDAY. EXCEPT FOR EARLY MORNING CLOUDS OVER SE ZONES, SKIES WILL BE SUNNY. EXTENDED (SUN NIGHT-FRI)..SUN NIGHT LOOKS CHILLY WITH MANY PLACES FALLING INTO THE MID-UPPER 20S. MON-TUE WILL FEATURE A BIG WARMUP, AND TUE COULD EVEN BE HOT, BY APRIL STANDARDS AT LEAST. 850MB TEMPS WILL BE +8-10C ON MONDAY...THEN +13-15C ON TUE, WHICH TRANSLATES TO MID 60S TO LOWER 70S ON MON, AND UPPER 70S TO MID 80S ON TUE. LAST YEAR ABOUT THIS TIME WE SET RECORD HIGHS, BUT IT LOOKS LIKE HIGHS TUESDAY WILL BE A BIT SHY OF THE RECORDS. WED WILL BE ANOTHER WARM DAY...WITH A COLD FRONT ENDING THE WARM SPELL ON THU AND GIVING US OUR NEXT CHANCE OF SIGNIFICANT PRECIP. TEMPS FRI LOOK LIKE THEY WILL BE BELOW NORMAL AGAIN. WORK ZONES OUT. ZONES SOON. .BGM...NONE. VAN AUSDALL ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 1042 AM EDT SAT APR 12 2003 GUIDANCE SHOWS SHARP TROUGH AT 18Z THROUGH CANADIAN MARITIMES AS A SHORT WAVE RIDES SOUTH ACROSS WESTERN NEW YORK AROUND 18Z WITH A SMALL AREA OF VORTICITY BY EVENING. THE TROUGH CARRIES ALONG WITH IT A BANK OF CLOUDS WHICH ON THE BUFKIT IS BELOW 5 THOUSAND FEET. RUC12 INDICATES ABOUT 80 TO 90 PERCENT RH BUT ETA ONLY 45 TO 50 PERCENT. AVN GOES BONKERS ADDING PRECIPITATION. SATELLITE HOWEVER SHOWS LOTS OF BREAKS IN THE CLOUDS ALTHOUGH MORE DENSE OVER THE OTTAWA VALLEY AND EAST CENTRAL ONTARIO CANADA. IF ANY AREA IS TO GET MAINLY CLOUDY IT APPEARS TO BE MAINLY NORTH COUNTRY. WILL PUT A LITTLE SUN MIXED WITH THE CLOUDS THIS AFTERNOON MOST AREAS AND A LITTLE MORE LEANING ON CLOUDS NORTH COUNTRY. REST OF FORECAST OK FOR NOW AND BELOW IS REST OF PREVIOUS DISCUSSION. BY TONIGHT...THE BROAD BASED RIDGE OVER THE PLAINS STATES WILL START TO WORK INTO THE WESTERN GREAT LAKES WHILE SFC HIGH PRESSURE WILL EXPAND FROM JAMES BAY SOUTHWARDS ACROSS THE OHIO VALLEY. PLENTY OF SUBSIDENCE AND DRIER AIR WILL LEAD TO A CLR/PC NIGHT. THE RIDGE WILL THEN CONTINUE TO BUILD EAST SUNDAY THROUGH TUESDAY WITH DAY TO DAY WARMING TAKING PLACE. FOR MONDAY AND TUESDAY...H8 TEMPS WILL CLIMB ABOVE +10C. THIS WILL MEAN HIGH TEMPS WELL INTO THE 60S...WITH LOW 70S POSSIBLE FOR TUESDAY IN THE GENESEE VALLEY. A SW FLOW AT THE SFC THOUGH WILL KEP THINGS QUITE COOL FOR BUFFALO AND ITS IMMEDIATE SUBURBS WITH HIGHS IN THE UPPER 50S TO LOWER 60S. SORRY... NEXT REAL WEATHER MAKER WILL MOVE IN FOR MID WEEK WITH A TROF INTRODUCING RW/TRW TO THE REGION. FURTHER DOWN THE ROAD...CPC FORECASTS FOR TEMPERATURES TO REMAIN ABV NORMAL FOR THE 8 TO 14 DAY PERIOD WITH ABV NORMAL AMOUNTS OF PCPN. .BUF...NONE. EGR/RSH $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 925 PM EDT SAT APR 12 2003 CURRENT FORECAST IS IN GOOD SHAPE. NO ZFP UPDATE PLANNED THIS EVENING. LATE DAY WEAK SEABREEZE FINALLY MADE IT ACROSS PORTIONS OF BRUNSWICK COUNTY W/ SSW FLOW AND HIGHER DWPTS FOUND IN ITS WAKE. OVERALL SKIES WILL BE CLEAR W/ A VERY DRY COLUMN IN PLACE (PWATS AOA 0.5 INCHES). WIND WILL CONTINUE TO DECOUPLE THIS EVENING AHEAD OF A VERY WEAK/ILL DEFINED COLD FRONT ACROSS VA. THUS THERE SHOULD BE NO PROBLEM RADIATING TO FORECAST MINS OVERNIGHT. THE FRONT WILL SLIP THROUGH EARLY TOMORROW MORNING W/ NOT MUCH NET AFFECT ON THE WX. MARINE: RUC HAS A GOOD HANDLE ON THE INITIAL CONDITIONS W/ SW FLOW PREVAILING ACROSS THE COASTAL WATERS. THE FLOW IS EXPECTED TO DIMINISH A NOTCH ACROSS THE WATERS AND INVOF FRYING PAN. THE DIR WILL VEER TO A MORE WESTERLY DIR AS THE WEAK FRONT MOVES INTO THE AREA...THEN TO THE N A COUPLE HOURS EITHER SIDE OF 12Z SUN. ONLY VERY MINOR CHANGES PLANNED. FCSTID = 29 ILM 50 74 50 73 / 0 0 0 0 LBT 48 74 47 75 / 0 0 0 0 FLO 50 76 48 76 / 0 0 0 0 MYR 51 72 51 71 / 0 0 0 0 .ILM... NC...NONE. SC...NONE. PFAFF nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1005 AM EDT SAT APR 12 2003 FIRST PERIOD FORECASTS IN FINE SHAPE BUT WILL ISSUE LATE MORNING UPDATE FOR MINOR CHANGE OR TWO TO THE WIND SPEEDS... PRIMARILY FOR OUR NORTHERN MOUNTAIN COUNTIES AND SOME OF THE NC PIEDMONT COUNTIES. SPEEDS ARE A BIT HIGHER THAN FORECAST ALTHOUGH NOT BY MUCH. RUC ALSO SUPPORTS GOING A LITTLE HIGHER ON SPEEDS. AFTERNOON TEMPERATURE FORECASTS LOOK GOOD AND WEATHER WILL REMAIN SUNNY. .GSP... GA...NONE. NC...NONE. SC...NONE. LGL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 933 AM EDT SAT APR 12 2003 NO CHANGES NEEDED TO ONGOING FORECAST. AS SFC LOW EXITS UP THE COAST AND DEEPENS...HIGH PRESSURE OVER THE GREAT LAKES WILL MAKE ITS WAY ONTO THE EAST COAST. PLEASANT SPRING DAY IN STORE FOR THE CWA WITH SEABREEZE LIKELY ALONG THE COASTAL COUNTIES BY LATE IN THE DAY. SHOULD HAVE A SLIGHTLY BETTER PUSH INLAND OVER THE GA COUNTIES ACCORDING TO THE WORKSTATION ETA. MARINE...THE CURRENT FCST LOOKS GREAT AND IS GENERALLY IN LINE WITH THE LATEST MARINE OBSERVATIONS. THE SEA BREEZE IS XPCTD TO DVLP BY ERLY TO MID AFTN AS TEMPS RISE INTO THE 70S INLAND UNDER STRONG INSOLATION. WNDS WL BACK TO THE SW NEAR THE COAST ACROSS THE SC WTRS AND TO THE S ACROSS THE GA WTRS BY MID AFTN. BOTH THE RUC AND LCL WSETA ALREADY HAVE A GOOD HANDLE ON THIS AND IS REFLECTED WELL IN THE FCST. ONLY MINOR CHANGES ARE PLANNED WITH THE MRNG PKG. .CHS... GA...NONE. SC...NONE. $$ PY/ST sc EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 900 PM PDT SAT APR 12 2003 .SYNOPSIS...AN UPPER LEVEL LOW PRESSURE SYSTEM LOCATED OFFSHORE OF THE WEST COAST WILL KEEP THE INLAND NORTHWEST IN A SHOWERY WEATHER PATTERN FOR THE NEXT FEW DAYS. .DISCUSSION... .TONIGHT...DESPITE THE POTENTIAL FOR ATMOSPHERIC PYROTECHNICS OVER THE INLAND NW...ABOUT THE ONLY THING WE COULD MUSTER THIS AFTERNOON WAS A FAIRLY IMPRESSIVE CELL OVER THE BLUE MOUNTAINS NEAR ANATONE THAT PRODUCED PEA-SIZED HAIL. LOOKS LIKE MOST OF THE CONVECTION EARLIER...FAVORED THE MORE UNSTABLE AND BETTER SHEAR ENVIRONMENT OVER NORTH CENTRAL MONTANA PER THE SPC HOURLY SPC MESOSCALE ANALYSIS. WITH NO MORE DIURNAL HEATING AND VERY LITTLE UPPER LEVEL FORCING...SUSPECT THE CHANCE OF THUNDER IS GENERALLY DONE FOR THE NIGHT...ALTHOUGH THERE STILL IS QUITE A BIT OF UNSTABLE AIR ABOVE 700 MBS. DESPITE THE DIMINISHED THREAT OF THUNDER...PORTIONS OF THE CWA WILL SEE MORE SHOWERS TONIGHT. IN THE SHORT TERM...A MASS OF LIGHT PRECIPITATION ACROSS CENTRAL IDAHO...WILL LIKELY MOVE INTO THE PANHANDLE LATER THIS EVENING RESULTING IN SOME LIGHT PRECIPITATION. ANOTHER CHANCE WILL MOVE IN LATE TONIGHT...AS A SHORTWAVE TROF...CURRENTLY OVER SW OREGON MOVES NORTHWARD OVERNIGHT. IF THE ETA AND RUC FORECASTS FOR LATER TONIGHT ARE CORRECT...MOST OF THIS PRECIPITATION WILL FALL OVER THE WESTERN HALF OF THE CWA AS A WELL DEFINED SURFACE/850 MB TROF AXIS MOVES UP FROM THE SOUTH. THIS FEATURE IS EXPECTED TO MOVE TOWARD THE CANADIAN BORDER BY MID-MORNING. WILL UPDATE FORECASTS TONIGHT TO LOWER POPS MOST ZONES AND ADD TEMPORAL WORDING. WE WILL ALSO ELIMINATE THUNDER WORDING FROM THE FORECAST...ALTHOUGH THERE IS A VERY SLIM CHANCE OF SOME LIGHTNING NEAR WENATCHEE BY DAYBREAK. ...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 043/062/037/054/035/053 233442 COE 043/062/037/054/035/052 233442 PUW 044/063/037/056/036/053 233442 LWS 046/067/042/061/039/057 333442 CQV 041/062/036/054/034/057 133333 SPT 043/060/037/052/035/052 233443 WWP 039/057/034/049/033/053 355443 MWH 046/064/040/058/037/060 233332 EAT 049/065/042/058/038/059 333332 OMK 045/063/034/057/034/060 244222 .OTX...NONE. $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 945 AM CDT SAT APR 12 2003 UPDATED ZONES TO REFLECT CURRENT TRENDS ON THE CLOUD COVER TODAY. THIN LAYER OF CLOUDS SHOULD QUICKLY ERODE THIS AFTERNOON. SO ONLY MINOR ADJUSTMENTS TO CLOUD COVER IN THE ZONES. BASED ON RUC DATA...CURRENT HIGHS LOOK GOOD FOR THIS AFTERNOON. UPDATED ZONES ALREADY OUT. WILL NEED TO CLEAN UP WORDING ON ZONES AGAIN BY NOON DUE TO REMOVE MORNING WORDING. .GRB...NONE. $$ ECKBERG WWW.CRH.NOAA.GOV/GRB wi SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 313 AM CDT SUN APR 13 2003 PRETTY MUCH STATUS QUO ACRS CWA THIS AM. NOT A LOT OF CHG SINCE THIS TIME YDA AM. BOWLING BALL STILL SITTING OFF NW CA COAST W/DOWNSTREAM THERMAL RIDGE CONTG ABV NORMAL TEMPS ACRS CWA. WK LEAD WV EJECTING INTO THE DAKOTAS COMBINED W/SLOW MIGRATION OF WRN TROF ONSHORE WILL LEAD TO TIGHTENING PRES GRADIENT HERE AND WINDY DAY. MAIN CONCERN CONTS W/TEMP FCST AND WINDS THIS AFTN. HEAT WILL CONT TO RAMP TDA AND ESP SO ON MON AS THERMAL RIDGE SWELLS IN ADV OF WRN TROF. GOING RECORDS FOR APRIL 14TH IN JEOPARDY W/PROGGED/FCST MAX TEMPS AND WILL INSERT WORDING AS SUCH. FOREMOST SHRT TERM CONCERN WILL BE WINDS AS PRES GRADIENT INTENSIFIES INVOF PROGGED THERMAL TROF POSITION ACRS WRN NE. RUC40 EVEN A BIT MORE INTENSE AND GIVEN PROGGED DEEP MIXED LYR AND UNIDIRECTIONAL WIND PROFILE...SHOULD SEE EASILY SEE GUSTS INTO THE MID 30 KT RANGE. MAY BE SOME NEED FOR AN ADVISORY AS SUCH BY THIS AFTN. SOMETHING FOR THE DAY SHIFT TO WATCH. FOR NOW WILL BEEF UP GOING WORDING. OTHERWISE...WX NIL UNTIL LATE TUE. QUITE A BIT OF CONSENSUS W/OVERALL WRN TROF EVOLUTION AND TIMING NOW. STILL A BIG MSTR QUESTION MARK WHICH CONTS TO DICTATE KEEPING POPS ON THE LOWER SIDE...NONE THE LESS UPR/SFC SYS LOOKS TO BE QUITE STRONG ONCE IT EJECTS OUT ON TUE W/MODEST INSTABILITY INVOF LOW CNTR/TRAILING DRY LINE SURGE... IRREGARDLESS OF ETA/AVN 0 QPF. AFT THAT...WRN TROF RELOADS W/CONT INFLUX OF UPSTREAM SW/S PROMISING YET ANOTHER SYS BY NXT WEEKEND ASSUMING SYS DOESN/T SLOW DOWN MUCH LIKE CURRENT WRN TROF. STILL HAVE A PROB W/OVERALL COLD LOOKING GFS NUMBERS THEN GIVEN WARMER GFS ENSEMBLE GUIDANCE AT THAT RANGE...CONSISTENT OVERALL COLD BIAS PER GFS NUMBERS THIS SPRING AND LATEST GEM/ECMWF THERMAL GUIDANCE TWDS WEEKS END. NOT TO MENTION CONTD NRN STREAM SEPARATION. TIME WILL TELL. .GID...NONE. $$ T ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 235 AM CDT SUN APR 13 2003 FORECAST FOCI...RECORD WARM/DRY AIR...WIND AND TEMPERATURES FUELING FIRE WEATHER CONCERNS. DATA ANALYSIS SHOWING AN UPPER LEVEL RIDGE OVER THE CENTRAL U.S. AT THE SURFACE AT 06Z...WINDS HAVE BECOME SOUTHEAST AS THE PRESSURE GRADIENT CONTINUES TO INCREASE. HIGH PRESSURE REMAINS OVER THE GREAT LAKES REGION...WHICH IS REINFORCING THE DRY AIR/LOW DEWPOINTS OVER THE FORECAST AREA. MODEL INITIALIZATION REMAINS REASONABLE AND THE ETA/GFS/RUC LOOK GOOD AT 06Z. MODELS CONTINUE TO OVER ESTIMATE THE SURFACE DEWPOINTS. FOR TODAY...THE UPPER LEVEL RIDGE WILL CONTINUE TO BE PROGRESSIVE AND MOVE EAST. THIS WILL ALLOW THE STRONG PRESSURE GRADIENT OVER THE PLAINS TO EDGE EAST AS WELL. SUBSEQUENTLY...WINDS WILL INCREASE OVER THE FORECAST AREA TODAY. WARM ADVECTION AND INCREASING THICKNESSES SUGGEST A SIGNIFICANT INCREASE IN TEMPERATURES TODAY. WITHOUT MUCH OF A DEWPOINT INCREASE TODAY...IT SHOULD BE QUITE DRY. CONDITIONS ARE JUST BELOW RED FLAG WARNING CRITERIA OVER SOUTHEAST MINNESOTA. WILL HOLD OFF ON WARNING AT THIS TIME AND CONTINUE WATCH. WILL ALLOW THE DAY SHIFT TO ADDRESS THIS AS NEEDED. WINDS INCREASE OVER TODAYS SPEEDS ON MONDAY AS THE SURFACE PRESSURE GRADIENT INCREASES. BUFKIT SOUNDINGS DO SHOW 30 KNOT MIXED LAYER WINDS AT KLSE THAT WILL BE TRANSPORTED DOWN. HOWEVER...IT REMAINS TO BE SEEN IF THIS CAN BE REALIZED AT THE SURFACE. BLUFFS WILL TEND TO REDUCE THE WINDS DUE TO FRICTION. ETA/GFS DO SHOW A RECOVERY OF THE DEWPOINTS. WILL BE MORE PESSIMISTIC THAN WHAT THE VALUES ARE SUGGESTED BY ETA/GFS/NGM NUMERICAL/STATISTICAL OUTPUT. THIS IS CONSISTENT WITH WHAT HAS OCCURRED OVER THE PAST WEEK. TEMPERATURES WILL BE EVEN WARMER AS SUGGESTED BY THE CONTINUED INCREASE OF 850 MB TEMPERATURES AND INCREASING THICKNESSES. THE STRONG SOUTHWEST WINDS AND DEEP MIXING ARE A CLASSIC WARM PATTERN THAT WILL EXCEED MOS. WITH ALL OF THAT SAID...WILL SUGGEST THAT THE DAY SHIFT RE-EVALUATE THE FIRE WEATHER CONCERNS WITH THE WISCONSIN DNR REGARDING A POSSIBLE FIRE WEATHER WATCH MONDAY OVER WISCONSIN. FOR TUESDAY...WILL CONTINUE TO SIDE WITH THE SLOWER GFS HERE. THUS...EXPECT TUESDAY TO BE VERY MUCH LIKE MONDAY...ONLY WITH AN INCREASE IN DEWPOINTS. FORECAST IS IN GREAT SHAPE...ONLY MINOR CHANGES MADE. COORDINATION THIS MORNING...MPX/MKX/GRB. .LSE...WATCHES/WARNINGS/ADVISORIES...FIRE WEATHER WATCH FOR TODAY MNZ079-086>088-094>096. $$ KRC wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 930 AM EDT SUN APR 13 2003 ANALYSES SHOW HIGH PRES RIDGE OVER SRN FL AND A WEAK FRONT OVER NRN GA AND OVER CAROLINAS. WITH LITTLE PUSH BEHIND THE FRONT AM NOT EXPECTING THE ACTUAL FRONT TO MAKE IT INTO THE CWA. WINDS ARE WLY AND SHOULD SHIFT TO NW TO N THIS AFTN AS A WEAK LOW PRES FORMS OFF THE GA COAST. THIS APPEARS TO BE PARTLY IN RESPONSE TO A SHORTWAVE SEEN IN WATER VAPOR IMAGERY AND RUC ANALYSIS OVER CENTRAL GA AREA. JAX SOUNDING INDICATES PWAT 0.56 INCHES AND W TO NW FLOW IN LOW LEVELS. SOME MOISTURE BELOW 850 MB MAY DEVELOP SOME CU THIS AFTN. SEA BREEZE WILL BRING WINDS BACK TO ELY ALONG THE COAST. CURRENT ZONES LOOK GOOD AND LITTLE IF ANY CHANGE REQUIRED. MARINE...CWF PACKAGE LOOKS FINE. .JAX... FL...NONE. GA...NONE. ARS fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 940 AM CDT SUN APR 13 2003 DISCUSSION FOR 1000 AM ZONE UPDATE HIGH PRESSURE WILL BE LOSING ITS GRIP OVER THE AREA TODAY AS OUR NEXT SYSTEM CONTINUES TO DEVELOP OVER THE UPPER PLAINS. THE RIDGE THOUGH WILL CONTINUE TO ALLOW A LOCALIZED WIND OFF THE LAKE TODAY. THIS SHOULD PRECLUDE A CLASSIC ORGANIZED LAKE BREEZE FROM FORMING AS TEMPERATURES NEAR THE LAKE WILL BE HELD DOWN BY THE QUASI ONSHORE FLOW. AWAY FROM THE LAKE...EXPECT THE SYNOPTIC FLOW TO BECOME MORE SE. ACARS SOUNDINGS INDICATE SOUTH WINDS OF 15 TO 25 KNTS IN THE 975 TO 900 MB LAYER WHICH MAY LEAD TO SOME LIGHT GUSTS FROM THE SOUTH. TEMPERATURES WILL BE ADJUSTED BASED ON RUC THEATA-E CROSS SECTIONS...WHICH SHOW MIXING AWAY FROM THE LAKE WILL REACH 925 MB BY 1 PM AND 850 MB BY 4 PM. WITH 850 TEMPS PROGGED BETWEEN 8 AND 9 C...LOW 70S ARE POSSIBLE ACROSS NORTH CENTRAL ILLINOIS. .CHI...NONE. ROGOWSKI AVIATION DISCUSSION FOR 12Z TAFS OTHER THAN A LITTLE FOG AT GYY WITH 5SM WHICH WILL QUICKLY DISIPATE NOTHING ELSEWHERE. ANOTHER NICE SPRING DAY. MODELS SHOW WIND BY AFTERNOON SSE. WITH A E COMPONENT WOULD EXPECT A LAKE BREEZE TO MOVE IN TO MDW-ORD LATE AFTERNOON AND THEN OUT IN EVE AS WINDS TURN MORE SSW. JUST SOME CI LATE AND MAYBE A FEW AFTERNOON CU AT RFD. AF il SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1114 AM EDT SUN APR 13 2003 SURFACE HIGH PRESSURE AND VERY DRY AIR OVER SOUTHEAST MICHIGAN IS PROVIDING PLENTY OF SUNSHINE ACROSS THE AREA. THE VISIBLE SATELLITE LOOP SHOWS QUITE A BIT OF MID CLOUDS STREAMING SOUTHEAST ACROSS FAR NORTHERN LOWER MICHIGAN. THIS MID LEVEL MOISTURE SHOULD CONTINUE TO PUSH SOUTHEAST THIS AFTERNOON ATOP THE MID LEVEL RIDGE AXIS. SATELLITE LOOPS HAVE SHOWN THE CLOUDS TO DISSIPATE AS THEY WORK SOUTHEAST INTO THE DRIER AIR OVER CENTRAL LOWER MICHIGAN. THE CURRENT RUC AND MESO ETA SOLUTIONS INDICATE THIS WILL CONTINUE TO BE THE CASE THIS AFTERNOON. SO I THINK OUTSIDE OF SOME SCATTERED MID CLOUDS IN THE THUMB...SKIES WILL REMAIN MOSTLY SUNNY TO SUNNY. BASED ON THE CURRENT TEMPERATURE TRENDS...THE GOING FORECAST HIGHS LOOK GOOD. SO NO UPDATED GRIDS OR ZFPDTX WILL BE NEEDED THIS MORNING. CONSIDINE ............PREVIOUSLY ISSUED AREA FORECAST DISCUSSION......... TRANQUIL WEATHER PATTERN CONTINUES. SURFACE RIDGE RETREATS EAST TODAY AND TONIGHT...WITH FAIRLY BRISK WESTERLIES ALOFT BRINGING COLD FRONT INTO WESTERN LAKES REGION MONDAY...THEN MODELS REASONABLY DEPICT FRONT BECOMING ALIGNED MORE WEST TO EAST ACROSS GREAT LAKES MONDAY NIGHT AND TUESDAY WHILE SAGGING SOUTH. ETA STILL FASTER IN MOVING COLD FRONT SOUTH THAN GFS AS ETA SHORTWAVE RIDGE ALOFT... AHEAD OF WESTERN TROUGH MOVING IN LATER IN WEEK...A LITTLE SHARPER. ANOTHER STRONG SURFACE HIGH SETTLING IN NORTH OF GREAT LAKES WILL ALSO HELP SUPPRESS FRONT SOUTH...WITH GFS BRINGING VIGOROUS SURFACE WAVE INTO SOUTHERN LAKES REGION BY THURSDAY. PREVIOUS MODEL RUN TRENDS...COMPARED TO 24 HOURS AGO...SHOW GFS FASTER IN MOVING COLD FRONT SOUTHWARD INTO SOUTHERN GREAT LAKES...THOUGH SIMILAR TO 18Z RUN YESTERDAY...BUT STILL CONSIDERABLY SLOWER THAN ETA WHICH HAS BEEN QUITE CONSISTENT PAST FEW RUNS. ALSO...MODELS SHOW SLOWER TREND OF INCOMING MID LEVEL ENERGY AND ASSOCIATED SURFACE LOW CHURNING EASTWARD INTO CENTRAL PLAINS BY MID WEEK AND EVENTUALLY REACHING LAKES REGION. WILL GO ALONG WITH FASTER GFS TRENDS FOR COLD FRONT...THOUGH NOT YET READY YET TO GO AS FAST AS ETA. GENERAL LOW TO MID LEVEL SUBSIDENCE SEEN IN OMEGA FIELDS TO CONTINUE TODAY INTO TONIGHT...EVEN PREVAILING MONDAY. GFS PRETTY MUCH HOLDS OFF ANY SIGNIFICANT OMEGA LIFT UNTIL TUESDAY NIGHT...WHEN WILL MAKE FIRST MENTION OF SHOWERS/THUNDER...A BIT QUICKER THAN EARLIER FORECAST. DEEPER MOISTURE...850 TO 500 MB...RATHER MEAGER UNTIL LATER TUESDAY NIGHT OR WEDNESDAY AS PER GFS...WITH MOSTLY SUNNY/MOSTLY CLEAR OR AT MOST PARTLY CLOUDY DUE TO HIGH CLOUDS UNTIL TUESDAY AT LEAST. OTHERWISE AS FOR DYNAMICS... MODEST 850 TO 500 MB QVECTOR CONVERGENCE BY TUESDAY NIGHT...ANOTHER PUSH WEDNESDAY/THURSDAY AS MAIN WAVE MOVES IN. SURFACE CONVERGENCE BECOMING GOOD BY TUESDAY NIGHT AS SAGGING FRONT MOVES IN...SOME WEDNESDAY/THURSDAY AS WELL. MODEST 850 TO 500 MB FRONTOGENETICAL FORCING MOVING IN FROM THE NORTH TUESDAY NIGHT TOO...ALONG WITH 300K NET ISENTROPIC ADIABATIC OMEGA LIFT AND CONDENSATION PRESSURE DEFICITS LOWERING TO UNDER 30 MB MOST AREAS. INSTABILITY INDICATIONS TUESDAY NIGHT UNTIL PAST MID WEEK RATHER MARGINAL...WITH SURFACE TO 850 MB LIFTED INDICES SLIGHTLY NEGATIVE AT BEST...BUT K INDICES CLIMBING TO CLOSE TO 30. TEMPERATURES WILL BE SIMILAR TO EARLIER ZONE PACKAGE AND TO GUIDANCE...WITH LINGERING SYNOPTIC FLOW EASTERLY COMPONENT BOLSTERED BY LAKE BREEZES TODAY TO KEEP AREAS NEAR THE GREAT LAKES COOLER. .DTX...NONE. $$ DWD EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 1040 AM CDT SUN APR 13 2003 BASED ON CURRENT CONDITIONS AND THE RUC FORECAST...CURRENT ZONES ARE IN GOOD SHAPE. WINDS ARE A LITTLE BIT EAST OF SOUTH THAN CURRENT FORECAST ACROSS CENTRAL AND NORTH CENTRAL WISCONSIN...BUT SHOULD TURN DUE SOUTH BY EARLY THIS AFTERNOON. NO UPDATES ON THE ZONES ARE PLANNED THIS MORNING. .GRB...NONE. $$ ECKBERG WWW.CRH.NOAA.GOV/GRB wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 1235 PM CDT SUN APR 13 2003 AVIATION DISCUSSION FOR 18Z TAFS VFR NEXT 24HRS. RIDGE ACROSS MI/IN MOVES EAST TODAY AND TONIGHT. SOUTHERLY FLOW LATE THIS MORNING TURNS BACK SOUTHEASTERLY THIS AFTERNOON AND EXPECTING A WEAK LAKE BREEZE BY 20-22Z TO SHIFT WINDS ESE AT ORD/MDW. WINDS GO BACK SSE OVERNIGHT THEN SSW MID TO LATE MORNING MONDAY AND INCREASE WITH GUSTS TO 25KTS BY END OF THE PERIOD. CMS DISCUSSION FOR 1000 AM ZONE UPDATE HIGH PRESSURE WILL BE LOSING ITS GRIP OVER THE AREA TODAY AS OUR NEXT SYSTEM CONTINUES TO DEVELOP OVER THE UPPER PLAINS. THE RIDGE THOUGH WILL CONTINUE TO ALLOW A LOCALIZED WIND OFF THE LAKE TODAY. THIS SHOULD PRECLUDE A CLASSIC ORGANIZED LAKE BREEZE FROM FORMING AS TEMPERATURES NEAR THE LAKE WILL BE HELD DOWN BY THE QUASI ONSHORE FLOW. AWAY FROM THE LAKE...EXPECT THE SYNOPTIC FLOW TO BECOME MORE SE. ACARS SOUNDINGS INDICATE SOUTH WINDS OF 15 TO 25 KNTS IN THE 975 TO 900 MB LAYER WHICH MAY LEAD TO SOME LIGHT GUSTS FROM THE SOUTH. TEMPERATURES WILL BE ADJUSTED BASED ON RUC THEATA-E CROSS SECTIONS...WHICH SHOW MIXING AWAY FROM THE LAKE WILL REACH 925 MB BY 1 PM AND 850 MB BY 4 PM. WITH 850 TEMPS PROGGED BETWEEN 8 AND 9 C...LOW 70S ARE POSSIBLE ACROSS NORTH CENTRAL ILLINOIS. .CHI...NONE. ROGOWSKI il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 450 PM EDT SUN APR 13 2003 MAIN FCST CONCERNS ARE HOW HIGH WILL TEMPS RISE MON IN SUMMER LIKE WARMTH...THEN TIMING OF COLD FRONT MON NIGHT/TUE AND PCPN COVERAGE. WV IMAGERY/RUC ANALYSIS SHOW CLOSED MID/UPPER LOW JUST OFF W COAST WITH DOWNSTREAM RIDGE DOMINATING CNTRL CONUS. A SHORTWAVE LIFTING NE INTO SCNTRL CANADA WAS PRODUCING SCT SHRA/TSRA ACROSS SRN MANITOBA. CLOSER TO HOME...WAA/ISENTROPIC ASCENT REGIME LEADING TO BKN MID CLOUD DECK AND RADAR ECHOES ACROSS NRN MN/LAKE SUPERIOR/UPPER MI. VERY DRY LOW-LEVELS PER 12Z KGRB/KINL SOUNDINGS KEEPING PCPN LIMITED TO NOTHING MORE THAN SPRINKLES. EVEN A FEW ICE PELLETS OBSERVED EARLIER HERE AT THE OFFICE. 12Z RAOBS SHOW IMPRESSIVE WARM AIR OVER DAKOTAS WITH 850MB TEMPS AT KUNR/KABR/KBIS AT +19/+20/+21C RESPECTIVELY. AT THE SFC...20Z TEMPS WERE WELL INTO 80S TO NEAR 90 ACROSS THE DAKOTAS/WRN MN...A SIGN OF WHAT IS ON THE WAY FOR MON. LAST COUPLE OF MODEL RUNS HAVE BEEN A BIT MORE AGGRESSIVE WITH POLAR VORTEX DROPPING TO HUDSON BAY...RESULTING IN CONFLUENT FLOW BTWN NRN AND SRN BRANCHES SETTLING FARTHER S TOWARD UPPER LAKES. THIS IN TURN LEADS TO MORE SFC HIGH PRES BUILDING ACROSS ONTARIO/UPPER LAKES AND SUPPRESSION OF PCPN ASSOCIATED WITH SFC LOW EJECTING FROM SW. HOWEVER...MODELS STILL INDICATE A LOT OF UNCERTAINTY AS TO WHERE THE LIKELY SHARP NRN EDGE OF PCPN WILL SET UP MIDWEEK. AS A RESULT...CHANGES TO GOING FCST WILL BE MINOR UNTIL SITUATION BECOMES MORE CERTAIN. MODELS STILL SHOW 45-60KT LOW-LEVEL JET MOVING ACROSS FCST AREA TONIGHT BELOW STEEP 700-500MB LAPSE RATES AROUND 8C/KM. BEST CONVERGENCE/THETA-E ADV TENDS TO BE FOCUSED N OF UPPER MI NEAR NOSE OF JET...BUT CERTAINLY NOT UNCOMMON TO GET SCT CONVECTION TO DEVELOP ALONG/JUST AHEAD OF JET AXIS. DRY LOW-LEVELS PROBABLY MAKE THIS LESS OF A POSSIBILITY AND WILL THUS LEAVE GOING DRY FCST FOR TONIGHT. THIS WILL BE SOMETHING TO KEEP AN EYE ON THOUGH. INCREASING SFC PRES GRADIENT/STRONG LOW-LEVEL JET WILL RESULT IN BREEZY CONDITIONS DESPITE UNFAVORABLE TIME OF DAY FOR MIXING. THIS WILL KEEP TEMPS FROM FALLING MUCH...AND IN FACT TEMPS MAY RISE A FEW DEGREES ACROSS W AND N...AND ESPECIALLY IN DOWNSLOPE AREAS. SUMMERLIKE WARMTH STILL ON TRACK FOR MON. CONSENSUS ON 850MB TEMPS IS AROUND 14C WHICH TRANSLATES TO ROUGHLY MID 70S...BUT ITS NOTED THAT MODELS INITIALIZED A COUPLE OF DEGREES LOW ON WARMTH BASED ON 12Z RAOBS OVER DAKOTAS. WITH THERMAL RIDGE OVER THE AREA BY AFTN... SOURCE REGION OF AIRMASS OVER WRN PLAINS AND SOLID SW/WSW FLOW... 75-80 SHOULD BE COMMON AWAY FROM LAKE MICHIGAN INFLUENCE WITH HIGHEST READINGS IN FAVORED DOWNSLOPE AREAS. ONLY POTENTIAL COMPLICATION WOULD BE CLOUD COVER AS 12Z MODEL RUNS SHOW A BIT MORE MOISTURE IN THE LOW/MID LEVELS THAN PREVIOUS RUNS. IN ADDITION... SUBTLE SHORTWAVE IS TO TRACK INTO UPPER LAKES...AND ETA/GFS/NGM GENERATE SOME PCPN OVER OR VERY NEAR FCST AREA IN THE AFTN. NOT SOLD ON THIS GIVEN A CONTINUED LACK OF GOOD LOW-LEVEL MOISTURE. MODEL SFC DWPTS RISING TO 50F OR BETTER OVER AT LEAST PARTS OF THE FCST AREA LOOK MUCH TOO HIGH...SO POSSIBILITY OF CONVECTION DEVELOPING AHEAD OF COLD FRONT SLOWLY DRIFTING S TOWARD UPPER MI SHOULD BE VERY LIMITED. SEEMS MORE LIKELY PCPN WOULD BE FOCUSED JUST BEHIND BOUNDARY IN THE FORM OF ELEVATED CONVECTION WHERE MOISTURE/LIFT IS MAXIMIZED. MON NIGHT...ETA TREND WITH FRONT IS NOTABLY SLOWER. 00Z RUN HAD FRONT NEAR KMKE BY 12Z TUE. 12Z RUN HAS IT NEAR KMNM AT 12Z TUE. WILL THUS CONTINUE TO FAVOR THE SLOWER MORE CONSISTENT GFS/CANADIAN/UKMET SOLUTIONS. WILL GENERALLY CARRY CHC POPS ALONG/BEHIND FRONT. TUE HIGHS WILL BE SIGNIFICANTLY COOLER... ESPECIALLY NEAR LAKE SUPERIOR AS NE WINDS LOCK IN ACROSS THE LAKE. FCST GETS QUITE COMPLICATED TUE NIGHT/WED AS THERE IS MUCH UNCERTAINTY IN HOW DOMINANT NRN STREAM WILL BE IN SUPPRESSING SRN STREAM SHORTWAVE. THIS AFFECTS CRITICAL PLACEMENT OF STRONG BAROCLINIC ZONE ACROSS THE LAKES AND THUS PTYPE AND LOCATION OF POTENTIALLY HEAVY PCPN. GFS IS FARTHEST N AND HAS 1.5 TO 2.5 INCHES OF PCPN FROM TUE EVENING TO THU MORNING...OF WHICH HALF WOULD PROBABLY BE SNOW/SLEET. EVEN THOUGH CANADIAN IS FARTHER S...IT ALSO BRINGS SIGNIFICANT PCPN INTO UPPER MI TUE NIGHT. UKMET FOCUSES ITS HEAVIER PCPN FROM SRN MN TO NRN LWR MI TUE NIGHT. DIFFICULT TO ASSESS WHICH MODEL MAY HAVE THE EDGE...BUT TREND HAS BEEN FOR INCREASED HIGH PRES BUILDING OVER ONTARIO UNDER STRONGER NRN BRANCH. RESULTING ERLY FEED OF DRY LOW-LEVEL AIR WILL LIKELY LEAD TO SHARP NRN EDGE OF PCPN. WITH ALL THE UNCERTAINTY...WILL LEAVE GOING FCST AS IS (LIKELY POPS TUE NIGHT/WED) UNTIL BETTER MODEL CONSENSUS DEVELOPS...BUT FEELING IS POPS WILL NEED TO BE CUT BACK...ESPECIALLY N. RAIN WILL MIX WITH/CHANGE TO SNOW FROM NW TO SE AS COLD AIR DEEPENS. THU-SUN...GFS/CANADIAN/UKMET/ECWMF ARE IN BETTER AGREEMENT FOR THIS PERIOD. SRN STREAM SYSTEM DISCUSSED ABOVE FOR WED WILL BEGIN TO EXIT AREA THU WITH LINGERING PCPN DIMINISHING. WILL PLAN FOR A DRY DAY FRI...THEN ATTENTION TURNS TO NEW TROF DEVELOPING OVER WRN CONUS. MODELS ARE IN GREAT AGREEMENT ON POSITION OF TROF AXIS FRI/SAT. HOWEVER...00Z GFS IS QUICKER WITH A PIECE OF ENERGY EJECTING NE TOWARD UPPER MIDWEST BY SAT MORNING WITH PCPN BREAKING OUT ACROSS FCST AREA SAT. 00Z GFS ENSEMBLES/06Z GFS DO NOT SUPPORT SUCH QUICK MOVEMENT AND THIS IS PREFERRED BY HPC. WILL HOLD ONTO DRY WEATHER SAT AND THEN INTRODUCE CHC POPS ON SUN AS SYSTEM LIFTS INTO MID MISSISSIPPI VALLEY. .MQT...FIRE WEATHER WATCH MONDAY MIZ009>012. ROLFSON mi SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 201 PM CDT SUN APR 13 2003 STILL WARM WITH WINDY PERIODS THROUGH TUESDAY...BEFORE UPPER LOW MOVES ACROSS THE AREA BRINGING AT LEAST A SMALL CHANCE FOR THUNDERSTORMS. MORNING UPPER AIR ANALYSIS SHOWS CENTRAL PLAINS IN CENTER OF UPPER HEIGHT RIDGE. WARMEST AIR HAS BEEN SHOVED TO THE NORTHERN PLAINS PER H85 CHART THIS MORNING. MODERATE MOISTURE RETURN OF +5-7C H85 DEWPOINTS INTO OKLAHOMA...WITH SURFACE REFLECTION OF 55 DEWPOINTS CROSSING THE RED RIVER AT 14Z. FAIRLY TIGHT SURFACE GRADIENT OVER THE CWFA...AND RUC40 SAYS THIS WILL HOLD TRUE TODAY ALL AREA EXCEPT FAR WESTERN 3 COUNTIES OF NEBRASKA CWFA. ONE WAVE SLIDING ACROSS THE AREA BRINING SOME MID LEVEL CLOUDS PER STEEP LAPSE RATES. NEW MEXICO WAVE SLIDING EAST SPREADING MID/HIGH CLOUDS TO OUR SOUTH WITH YET ANOTHER SHORTWAVE DOING THE SAME ACROSS THE NORTHERN ROCKIES. CONTINUE WARM THROUGH MONDAY NIGHT...WITH RECORD TERRITORY POSSIBLE FOR HASTINGS. SOUTHEAST ZONES WILL REMAIN THE BREEZIEST. TUESDAY...LOW PRESSURE WILL SLOWLY FORM WEST OF HILL CITY AND WE SHOULD SEE SOME BACKING FLOW PULLING MORE MOISTURE IN THE REGION. MOISTURE WILL LIKELY POOL NEAR BAROCLINIC ZONE ACROSS NORTHERN COUNTIES...WITH SURFACE DEWPOINTS NEAR 60. SHARPENING DRYLINE WILL TAKE SHAPE BY EVENING SOUTHWEST NEBRASKA INTO WESTERN KANSAS. DAY3 OUTLOOK HAS GOOD HANDLE ON AREA...WITH ISOLATED TO SCATTERED STORMS EXPECTED BY EVENING ACROSS NORTHERN CWFA. DRYLINE WILL TURN INTO THE FOCUS THROUGHOUT THE EVENING. HAVE CONTINUED WITH CHANCE POPS FOR THE CWFA...WITH 'HIGHER' POPS FAVORING EAST AND NORTH. MODERATELY UNSTABLE ATMOSPHERE SUPPORTS POTENTIAL FOR SOME SEVERE STORMS. WEDNESDAY IS NOTHING BUT COLD ADVECTION...AND WITH UPPER LOW JUST TO OUR EAST...THE PRESENCE OF CLOUDS AND SHOWERS SEEM IN LINE. MY CONCERN IS IT MY COLDER THAN WE HAVE NOW...AS ETA EASILY SWIPES THE 0C H85 LINE INTO THE CWFA. HAVE KEPT TEMPERATURES WITH ONLY A REBOUND OF ABOUT 10 DEGREES WEDNESDAY...AND THAT MAY BE TOO MUCH. THURSDAY THROUGH SUNDAY...THURSDAY IS A DRY DAY. BELIEVE THE GFS IS TOO FAST WITH SHORTWAVE KICKING OUT FRIDAY. FAVORING A SLOWER EC/CMC RENDITION. HAVE ALIGNED WITH SURROUNDING OFFICES. STILL HESITANT TO ESSENTIALLY RAIN-OUT THE EASTER WEEKEND. SEEMS THE POSSIBILITY OF SPLIT FLOW SETTING UP IS MORE LIKELY...WHICH TENDS TO LEAVE US SEASONAL AND DRIER. ECHO THE MID-SHIFT FORECASTER SAYING "TIME WILL TELL". .GID...NONE. $$ MORITZ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 314 PM CDT SUN APR 13 2003 LATEST SURFACE ANALYSIS HAS A 1006 SURFACE LOW LOCATED NEAR LA JUNTA COLORADO. 18Z RUC MODEL SHOWS LOW LEVEL MOISTURE ADVECTION WITH 8H DEW POINTS NEAR 10 DEGREES CELSIUS APPROACHING THE SOUTHEAST TEXAS PANHANDLE. WEAK DRYLINE IN PLACE TONIGHT. EXPECT 40 KT LOW LEVEL JET AGAIN TONIGHT WITH ADDITIONAL MOISTURE ADVECTION CONTINUING INTO MONDAY. MID LEVEL RIDGE AXIS PROGED TO SHIFT EAST OVERNIGHT TONIGHT AS POWERFUL SOUTHWEST UPPER LOW CONTINUES TO DEVELOP. DECENT CAP IN PLACE OVER THE SOUTH PLAINS...SHOULD PRECLUDE CONVECTION TONIGHT DESPITE MODEST INSTABILITY AND MINOR CU FIELD. WILL GO WITH A DRY FIRST PERIOD. DRYLINE RETREATS WESTWARD MONDAY NIGHT INTO TUESDAY MORNING. HAVE DECIDED TO MAINTAIN 20 PERCENT POPS MONDAY NIGHT AREAWIDE WITH WEAK MID LEVEL IMPULSE APPROACHING FROM THE WEST MONDAY AFTERNOON...WELL AHEAD OF MAIN SYSTEM. TUESDAY...MODEL CONSENSUS 70KT 5H JET APPROACHES FROM CENTRAL NEW MEXICO. STRONG DRY/DOWNSLOPE GRADIENT WINDS LOOK LIKELY. MAY NEED A HIGH WIND WATCH MONDAY FOR WINDS TUESDAY AFTERNOON...FUTURE SHIFTS WILL NEED TO MONITOR. LATEST THINKING IS THAT DRYLINE/INSTABILITY WILL BE PRETTY WELL EAST OF THE PANHANDLES TUESDAY AFTERNOON SO HAVE ADJUSTED DEW POINT GRIDS AND DROPPED SLIGHT CHANCE POPS FAR WEST. HIGH FIRE DANGER WILL BE AN ASSOCIATED CONCERN. NEXT DILEMMA IS FOR POST FRONTAL COOL ADVECTION WEDNESDAY. APPEARS COLD AIR WILL BE DEEPER OVER THE NORTHEAST COUNTIES WHERE TEMPS IN THE LOW 60S LOOK POSSIBLE. TEMPS RECOVER TO CLIMATOLOGY ON THURSDAY. MADE NO CHANGES TO THE FRIDAY/FRIDAY NIGHT GRIDS. STILL LOTS OF UNCERTAINTY REGARDING THE SYSTEM TRACK AND DEGREE OF INSTABILITY PRESENT. HAVE ALSO KEPT 20 POPS IN THE EAST ON SATURDAY. INTRODUCED SUNDAY DRY FOR NOW. FCSTID = SLATTERY AMARILLO 51 84 53 80 / 00 00 20 20 BEAVER 50 87 55 80 / 00 10 20 20 BOISE CITY 46 81 48 73 / 00 00 20 10 BORGER 49 87 53 80 / 00 00 20 20 BOYS RANCH 48 85 49 79 / 00 00 20 10 CANYON 50 85 50 80 / 00 00 20 10 CLARENDON 52 87 54 82 / 00 10 20 20 DALHART 47 82 48 76 / 00 00 20 10 GUYMON 48 86 52 78 / 00 00 20 20 HEREFORD 49 84 49 78 / 00 00 20 00 LIPSCOMB 50 87 55 81 / 00 10 20 20 PAMPA 50 86 54 82 / 00 00 20 20 SHAMROCK 52 89 55 83 / 00 10 20 20 WELLINGTON 54 89 56 83 / 00 10 20 20 .AMA... TX...NONE. OK...NONE. $$ tx