Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 12/16/06

.SHORT TERM... WINDS HAVE REMAINED BELOW ADVISORY AMOUNTS THIS AFTERNOON EXCEPT IN ISOLATED WIND PRONE AREAS WHERE GUSTS HAVE REACHED 45-50 MPH...BUT WINDS HAVE STILL BEEN BREEZY ELSEWHERE. THE COLD FRONT HAS BEEN SLOW TO MOVE SOUTH THIS AFTERNOON AND IS NEAR THE RENO AREA. THE FRONT WILL SAG SOUTH THROUGH THIS EVENING AS THE NEXT POTENT SHORT WAVE NEAR 40N 135W APPROACHES. ALL MODELS ARE PROJECTING GOOD FRONTOGENESIS TO ENHANCE PRECIP ALONG THE FRONT IN NV TONIGHT AND SATURDAY. DIVERGENCE ALONG AND NORTH OF THE JET ALONG WITH A DEVELOPING SURFACE LOW OVER NYE COUNTY LATER TONIGHT WILL FURTHER ENHANCE SNOW ALONG THE FRONT. THE MAIN QUESTION IS WHERE THE FRONT WILL STALL AND WHERE THE HEAVIER SNOW BANDS WILL BE LOCATED...ALONG WITH HOW MUCH SNOW WILL FALL. RIGHT NOW IT LOOKS LIKE THE STRONGEST FRONTOGENESIS WILL INITIALLY BE NEAR HIGHWAY 50 OR JUST NORTH. THEREFORE A SNOW ADVISORY WAS ISSUED FOR THE RENO/CARSON CITY AREA...CHURCHILL...PERSHING AND MINERAL COUNTIES. IF THIS BAND DOES DEVELOP NEAR HIGHWAY 50 IT WILL SAG SOUTH THROUGH THE MORNING ON SATURDAY. THEREFORE IT COULD CLIP A PORTION OF 3 ZONES. RIGHT NOW IT IS LOOKING LIKE LOW END ADVISORY AMOUNTS...OR A QUICK 1 TO 3 INCHES IN THE HEAVIER BAND. HOWEVER THE SWING SHIFT WILL HAVE TO KEEP AN EYE ON BOTH THE LOCATION AND INTENSITY OF THE BAND TO MAKE SURE SNOW ADVISORY IS STILL ON TRACK. ELSEWHERE LIGHTER SNOW SHOWERS WILL CONTINUE IN THE SIERRA THROUGH SATURDAY AS THE TROUGH APPROACHES.

THE MODELS ARE IN FAIRLY GOOD AGREEMENT INTO SUNDAY AND MONDAY WITH POSITIVE TILT TROUGH MOVING INTO THE ERN CWA ON SUNDAY AND DEVELOPING A CLOSED LOW OVER SRN CA/SRN NV ON MONDAY. THE SHOWERS WILL DECREASE ON SUNDAY AS TROUGH DROPS SOUTH...BUT EASTERLY UPSLOPE FLOW WILL LIKELY PRODUCE SOME SNOW IN THE SIERRA SOUTH OF LAKE TAHOE WHERE THE DEEPEST MOISTURE LINGERS. THIS WILL BRING CONCERNS FOR ACCUMULATING SNOW TO MONO COUNTY ESPECIALLY. LATER SHIFTS CAN EVALUATE THE SNOW POTENTIAL. TEMPERATURES WILL DROP TONIGHT AND MORE SIGNIFICANTLY INTO SUNDAY AND MONDAY. HIGHS WILL DROP INTO THE LOW TO MID 30S IN WRN NV VALLEYS OVER THE WEEKEND INTO NEXT WEEK AND LOWS WILL DROP INTO THE TEENS WITH SOME AREAS SEEING SINGLE DIGITS IN NV. IN THE SIERRA...HIGHS WILL REMAIN IN THE 20S AND 30S WITH LOWS IN THE SINGLE DIGITS. BENINATO

.LONG TERM...TUESDAY THROUGH FRIDAY... CUTOFF LOW OVER SOUTHWESTERN US WILL SLOWLY PUSH INTO THE SOUTHERN ROCKIES...WHICH WILL KEEP TEMPS NICE AND COLD TUESDAY AND WEDNESDAY OVER OUR REGION. LOWS WILL DIP DOWN INTO THE SINGLE DIGITS IN THE TAHOE REGION...AND LOW TEENS IN THE NV VALLEYS. IF WE GET SIGNIFICANT SNOW COVER THIS WEEKEND OVER THE REGION...LOWS COULD BE EVEN COLDER NEXT WEEK. AN UPPER RIDGE WILL PUSH INTO THE WESTERN US...BEHIND THE DEPARTING UPPER-LOW. NORTH/NORTHEASTERLY FLOW AROUND THE RIDGE WILL CONTINUE TO BRING DRY AIR OVER THE REGION. EXPECT MOSTLY CLEAR SKIES NEXT WEEK WITHOUT ANY SIGNIFICANT PRECIP ACROSS THE REGION. 18Z GFS IS TRYING TO BRING IN A SHORTWAVE TO NORTHERN CALIFORNIA BY WEDNESDAY...BUT 0Z/12Z GFS HAS NOT SHOWN THIS FEATURE SO FAR. 12Z ECMWF AND UKMET ALSO AGREE WITH A DRY PATTERN AND RIDGING NEXT WEEK. I DON`T HAVE MUCH CONFIDENCE WITH THIS WAVE AT ALL...DID NOT RAISE ANY POPS AT THE MOMENT FOR WED/THURS...BUT WE COULD SEE A DRASTIC CHANGE IN THE FORECAST FOR NEXT WEEK IF THIS WAVE DOES IN FACT MATERIALIZE. HOON

&

AVIATION... PACIFIC SYSTEM CURRENTLY PUSHING ACROSS GREAT BASIN. MODERATE SURFACE WINDS ACROSS THE REGION...DUE TO COLD FRONT...MODERATE TO SEVERE LOW LEVEL TURBULENCE OVER THE SIERRA...REPORTED BY AIRCRAFT...CONTINUING UNTIL 9Z. WINDS SHOULD WEAKEN AND SHIFT OUT OF THE NORTH OVERNIGHT WITH THE PASSAGE OF THE COLD FRONT. LIGHT TO MODERATE MIXED ICING 050 TO 100. SCATTERED LIGHT RAIN AND SHOW SHOWERS WILL AFFECT MUCH OF THE REGION OVERNIGHT...WITH THE HEAVIEST SNOW OVER CENTRAL AND EASTERN NEVADA. EXPECT PERIODS OF MVFR/IFR CONDITIONS WITH HEAVIER SNOW SHOWERS. HOON

&&

.REV WATCHES/WARNINGS/ADVISORIES...

NV...SNOW ADVISORY NVZ003-004 FROM 1 AM TO 1 PM PST SATURDAY. SNOW ADVISORY FOR NVZ001 FROM 4 AM TO 4 PM PST SATURDAY. CA...NONE.

&&

$$

HTTP://WEATHER.GOV/RENO

.SYNOPSIS...COASTAL LOW CLOUDS AND FOG WILL DEVELOP LATE TONIGHT AND FRIDAY MORNING AND THERE WILL BE VARIABLE HIGH CLOUDINESS THROUGH FRIDAY. A COLD STORM APPROACHING FORM THE GULF OF ALASKA WILL LIKELY BRING RAIN AND MOUNTAIN SNOW ALONG WITH LOCAL GUSTY WINDS SATURDAY AND SATURDAY NIGHT. SHOWERS COULD LINGER INTO SUNDAY. COLD DRY OFFSHORE FLOW MONDAY AND TUESDAY. FAIR AND AND A LITTLE WARMER TOWARD THE MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES.

.SHORT TERM (TODAY-SUNDAY)...THERE WERE A FEW PATCHES OF RADIATIONAL GROUND FOG IN THE INLAND AREAS THIS MORNING...OTHERWISE VARIABLE HIGH CLOUDINESS. EARLY AFTERNOON ACARS SOUNDINGS INDICATED AN INVERSION BASED BELOW 1000 FT WITH N TO NW WINDS ALOFT. WEAK ONSHORE GRADIENTS TO THE E AND ONSHORE TRENDS.

SMALLER SCALE MODELS INDICATE AN EDDY SPINNING UP TONIGHT RESULTING IN A DEEPENING MARINE LAYER TONIGHT AND FRI MORNING. COOLER FRI...ESPECIALLY W OF THE MOUNTAINS AS HEIGHTS LOWER AND ONSHORE FLOW INCREASES. A STORM FROM THE GULF OF ALASKA IS STILL EXPECTED TO IMPACT OUR AREA THIS WEEKEND. HOWEVER...MODELS HAVE BACKED OFF ON THE AMOUNT OF MOISTURE AVAILABLE AND THEY ARE ALSO MORE PROGRESSIVE BRINGING IT IN QUICKER AND MOVING IT OUT EARLIER. IT CURRENTLY LOOKS LIKE THERE WILL BE A DECENT COLD FRONTAL PASSAGE LATE SAT BUT THERE COULD BE A FEW PRE FRONTAL SHOWERS AS EARLY AS LATE FRI NIGHT AND SAT MORNING. A CHANCE OF SHOWERS WILL LINGER INTO SUN...MAINLY FROM ISLAND EFFECTS AND OROGRAPHICS. THE SNOW LEVEL WILL START OUT ABOVE 7000 FT AND THEN LOWER TO BETWEEN 5000-4000 FT SAT. THE SNOW LEVEL WILL BE LOWER MORE LATE SAT NIGHT AND SUN AND WOULD NOT BE SURPRISED TO GET A FEW SNOW FLURRIES DOWN TO 2000 FT. GUSTY WINDS WILL ACCOMPANY AND FOLLOW THE FRONT...MAINLY IN THE MOUNTAINS AND POSSIBLY HIGH DESERTS WHERE THEY SHOULD BE NEAR ADVISORY STRENGTH. ESTIMATED PRECIP TOTALS GENERALLY RANGE FROM ABOUT A QUARTER TO HALF AN INCH W OF THE MOUNTAINS WITH LOCAL AMOUNTS OF AN INCH OR TWO ON THE W AND SW FACING MOUNTAIN SLOPES BELOW THE SNOW LEVEL. THERE COULD BE LOCAL SNOW ACCUMULATIONS OF ABOUT 6 TO 18 INCHES.

.LONG RANGE (MONDAY-THURSDAY)...COLD DRY OFFSHORE FLOW DEVELOPS MON WHICH WILL RESULT IN LOCAL STRONG GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES. THE OFFSHORE CONTINUES TUE WITH A LITTLE WARMING. BIG DISAGREEMENTS IN THE MODELS TOWARD THE MIDDLE OF NEXT WEEK ON WHETHER THERE WILL BE RIDGING ALOFT OR A WEAK UPPER LOW. WILL GO WITH GENERALLY FAIR AND A LITTLE WARMER WEATHER FOR NOW.

&&

.AVIATION... WIND FLOW BACKING FROM N TO W DURING NEXT 12 HOURS ABOVE FL020. BELOW FL020 WIND FLOW BECOMING SOUTHERLY AS COASTAL EDDY SPINS UP. BETWEEN 1900 PST/0300 UTC AND 0400 PST/1200 UTC EXPECT TO SEE LOW STRATUS...GENERALLY BELOW FL005...MOVING UP COAST FROM ENSENADA TO VICINITY NEWPORT BEACH...AND BETWEEN 0400 PST/1200 UTC TO 1000 PST/1800 UTC FRIDAY A LIFTING OF THE STRATUS LAYER TO FL006-FL012 AND SPREADING INLAND. MULTIPLE CIRRUS LAYERS WILL CONTINUE ABOVE FL200 THROUGHOUT THE NEXT 12 HOURS.

&&

.MARINE... A LARGE 10 FT NW SWELL WITH 10-15 SEC PERIOD WILL ARRIVE IN THE COASTAL WATERS SATURDAY NIGHT...HOWEVER COLD FRONT MOVING ACROSS AREA AT SAME TIME WITH SUSTAINED WINDS OF +20 KT...WILL BE GENERATING WIND WAVES +4 FEET SO VERY ROUGH CONDITIONS EXPECTED. SHIFT TO OFFSHORE WINDS BY SUNDAY MORNING...SHOULD BEAT DOWN THESE WIND WAVES.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...

SPECIAL WEATHER STATEMENT FOR THE WEEKEND STORM. SEE LAXSPSSGX.

ABOVE NORMAL SURF WILL CAUSE AN ELEVATED AND DANGEROUS RIP CURRENT RISK AT THE BEACHES THROUGH MONDAY. SEE LAXSRFSGX.

&&

$$

PUBLIC...DVA AVIATION...BALFOUR

.DISCUSSION FOR LATE MORNING UPDATE...

1110 AM CST JUST A QUICK UPDATE TO GRIDS/ZFP FOR CURRENT RADAR/OBS TRENDS. BASED ON TIMING OF BACK EDGE OF CLOUDS AND RADAR RETURNS NOW IN EASTERN IOWA...EXPECT CLEARING IN NORTH CENTRAL IL INCLUDING ROCKFORD BY NOON...BUT CLOUDS AND SPRINKLES WILL LINGER TO EARLY OR MID AFTERNOON CHICAGO METRO AREA AND NW IN. EXPECT SOME SUN BY MID AND LATE AFTERNOON SO TEMPERATURE FORECAST LOOKS LIKE IT IS STILL ON TRACK.

ALLSOPP

.DISCUSSION FOR MORNING GRIDS/ZONES... 330 AM CST

SYNOPTIC SCALE PATTERN BEGINS THE FCST PD IN A FAST/LOW AMPLITUDE REGIME WITH A CLIPPER-TYPE SHORT WAVE DIGGING INTO THE UPPER MISSISSIPPI VALLEY THIS MORNING AND THEN TRACKING ACROSS THE GREAT LAKES REGION. THIS SYSTEM WILL SPREAD CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS ACROSS THE REGION...BRINGING AN ABRUPT END TO THE RARE DECEMBER SUNSHINE...BUT ANY PCPN ASSOCIATED WITH THE SHORT WAVE WILL REMAIN WELL NORTH OF THE WISCONSIN BORDER. THROUGH THE SHORT TERM...TEMPERATURES WILL REMAIN ABOVE SEASONAL NORMAL LEVELS. WHILE THE GUIDANCE IS TRENDING TOWARD A BIT MORE AMPLITUDE TO THE PATTERN THAN RECENT RUNS HAVE SUGGESTED...ANY SIGNIFICANT COLD AIR WILL REMAIN WELL NORTH OF THE CANADIAN BORDER AS THE NEXT COUPLE SYSTEMS TO APPROACH THE LOCAL AREA WILL BE OF PACIFIC ORIGIN...KEEPING THE REGION UNDER A MODERATE AIRMASS. THROUGH THE WEEKEND...HIGH TEMPERATURES ACROSS THE CWA WILL RANGE FROM NEAR 50 TO THE UPPER 50S...PARTICULARLY ACROSS THE SRN COUNTIES. BY THE WEEKEND...ANOTHER PACIFIC SYSTEM WILL TRACK ACROSS SOUTHCENTRAL CANADA...TURNING FLOW MORE SWLY ALOFT AND SLY AT THE SURFACE...TAPPING SOME GULF MOISTURE. BUT WHILE KEEPING TEMPERATURES MILD...THERE WILL ALSO BE OUR NEXT CHANCE FOR RAIN AS THE GFS IS SUGGESTING AN EXTENDED PERIOD OF STRONG POSITIVE THETA-E ADVECTION...THUS WILL KEEP THE BROADBRUSHED CHANCE RA ACROSS THE REGION.

FOR THE LONGER TERM...THE GFS IS SHOWING GOOD RUN TO RUN CONSISTENCY ON DIGGING A CUT OFF LOW INTO THE DESERT SOUTHWEST EARLY NEXT WEEK. BUT THE LATEST RUN IS TAKING THE UPPER LOW EVEN FARTHER SOUTH...INTO THE SONORA DESERT OF NRN MEXICO BEFORE EJECTING OUT INTO THE SOUTH HIGH PLAINS BY MIDWEEK. THIS SYSTEM WILL BEAR WATCHING AS IT WILL POTENTIALLY BE OUR NEXT MAJOR WEATHER MAKER.

KREIN

&&

.AVIATION DISCUSSION REGARDING 12Z TAFS... 545 AM CST

HIGH PRES OVR SERN U.S. AND LOW PRES CENTER MOVG EWD ALG U.S.-CAN BDR TDY WILL INCRS PRES GRADIENT AND RESULT IN WIND SPEEDS/GUSTS BEING MAIN WX PROBLEM NXT 24 HRS. VIGOROUS SHORT WAVE/IMPULSE IN JET STREAM WIND FIELD/ ASSD WITH LOW PRES TO N WILL MOVE ACRS WRN GRTLKS TDY AIDING INCRS IN SFC WIND SPEEDS. CURRENT SFC ANALYSIS ALSO SHOWS AXIS OF SIG SFC PRES FALLS /FOR THIS TIME OF THE MORNING ANYWAY/ FROM MN ARROWHEAD-NWRN WI-UPR MS VLY. THIS IS ALSO A GOOD INDICATOR THAT WIND SPEEDS WILL BE ON THE INCRS ACROSS MIDWEST THIS MRNG. IN ADDITION QUICK LOOK AT RFD AND ORD ACARS DATA TO CHECK FOR ANY LLWS ABV SFC INVERSION SHOWS WSWLY WINDS ARND 40 KTS AOA FL030. EXPECT WINDS NOW FROM S ARND 10 KTS TO INCRS QUICKLY THIS MRNG AS WX SYS TO NW APCHS...AND SFC HEATING AND WARMER AIR MOVG IN FROM SW ERODE LLVL INVERSION. WINDS EXPECTED TO BE ABOUT DUE SW...SUSTAINED IN 15-20 KT RANGE...BUT WITH FQT GUST TO NR 30 KTS LATE THIS MRNG-AFTN. WIND SPEEDS TO DMNSH A BIT TWD SS...BUT GUSTINESS EXPECTED TO CONT WELL INTO THE EVENING AS TROF ASSD WITH LOW TO N SWEEPS THRU AND TURNS WINDS TO W.

THIS WX SYS WILL RMN STARVED FOR MOISTURE...SO ONLY MID LVL CIGS TO PREVAIL THRU TDY...THEN THINNING TO SCT-BKN MID LVL CLOUDS LATE THIS AFTN. WITH AMPLE MIXING OF AIR THIS MRNG AND TNGT...NO VIS RESTRICTIONS EXPECTED SO CIGS/VIS TO RMN VFR THRU PERIOD.

MERZLOCK

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...GALE WARNING FOR THE SOUTH HALF OF THE OPEN WATERS OF LAKE MICHIGAN FOR THIS AFTERNOON AND TONIGHT. ...SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS FOR THIS AFTERNOON AND TONIGHT. &&

$$

.DISCUSSION FOR MORNING UPDATE...

735 AM CST

JUST A QUICK UPDATE TO GRIDS/ZFP FOR CURRENT RADAR/OBS TRENDS. SOME LIGHT SPRINKLES MAKING IT TO THE GROUND FROM 8-10 KFT MID LEVEL DECK EARLY THIS MORNING...WITH KRFD REPORTING 10SM -RA AT 13 UTC. SHOULD BE CONFINDED TO MAINLY EARLY TO MID MORNING HOURS WEST TO EAST...AND BE OUT OF THE WAY BY AFTERNOON.

RATZER

PREVIOUS DISCUSSION...

.DISCUSSION FOR MORNING GRIDS/ZONES... 330 AM CST

SYNOPTIC SCALE PATTERN BEGINS THE FCST PD IN A FAST/LOW AMPLITUDE REGIME WITH A CLIPPER-TYPE SHORT WAVE DIGGING INTO THE UPPER MISSISSIPPI VALLEY THIS MORNING AND THEN TRACKING ACROSS THE GREAT LAKES REGION. THIS SYSTEM WILL SPREAD CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS ACROSS THE REGION...BRINGING AN ABRUPT END TO THE RARE DECEMBER SUNSHINE...BUT ANY PCPN ASSOCIATED WITH THE SHORT WAVE WILL REMAIN WELL NORTH OF THE WISCONSIN BORDER. THROUGH THE SHORT TERM...TEMPERATURES WILL REMAIN ABOVE SEASONAL NORMAL LEVELS. WHILE THE GUIDANCE IS TRENDING TOWARD A BIT MORE AMPLITUDE TO THE PATTERN THAN RECENT RUNS HAVE SUGGESTED...ANY SIGNIFICANT COLD AIR WILL REMAIN WELL NORTH OF THE CANADIAN BORDER AS THE NEXT COUPLE SYSTEMS TO APPROACH THE LOCAL AREA WILL BE OF PACIFIC ORIGIN...KEEPING THE REGION UNDER A MODERATE AIRMASS. THROUGH THE WEEKEND...HIGH TEMPERATURES ACROSS THE CWA WILL RANGE FROM NEAR 50 TO THE UPPER 50S...PARTICULARLY ACROSS THE SRN COUNTIES. BY THE WEEKEND...ANOTHER PACIFIC SYSTEM WILL TRACK ACROSS SOUTHCENTRAL CANADA...TURNING FLOW MORE SWLY ALOFT AND SLY AT THE SURFACE...TAPPING SOME GULF MOISTURE. BUT WHILE KEEPING TEMPERATURES MILD...THERE WILL ALSO BE OUR NEXT CHANCE FOR RAIN AS THE GFS IS SUGGESTING AN EXTENDED PERIOD OF STRONG POSITIVE THETA-E ADVECTION...THUS WILL KEEP THE BROADBRUSHED CHANCE RA ACROSS THE REGION.

FOR THE LONGER TERM...THE GFS IS SHOWING GOOD RUN TO RUN CONSISTENCY ON DIGGING A CUT OFF LOW INTO THE DESERT SOUTHWEST EARLY NEXT WEEK. BUT THE LATEST RUN IS TAKING THE UPPER LOW EVEN FARTHER SOUTH...INTO THE SONORA DESERT OF NRN MEXICO BEFORE EJECTING OUT INTO THE SOUTH HIGH PLAINS BY MIDWEEK. THIS SYSTEM WILL BEAR WATCHING AS IT WILL POTENTIALLY BE OUR NEXT MAJOR WEATHER MAKER.

KREIN

&&

.AVIATION DISCUSSION REGARDING 12Z TAFS... 545 AM CST

HIGH PRES OVR SERN U.S. AND LOW PRES CENTER MOVG EWD ALG U.S.-CAN BDR TDY WILL INCRS PRES GRADIENT AND RESULT IN WIND SPEEDS/GUSTS BEING MAIN WX PROBLEM NXT 24 HRS. VIGOROUS SHORT WAVE/IMPULSE IN JET STREAM WIND FIELD/ ASSD WITH LOW PRES TO N WILL MOVE ACRS WRN GRTLKS TDY AIDING INCRS IN SFC WIND SPEEDS. CURRENT SFC ANALYSIS ALSO SHOWS AXIS OF SIG SFC PRES FALLS /FOR THIS TIME OF THE MORNING ANYWAY/ FROM MN ARROWHEAD-NWRN WI-UPR MS VLY. THIS IS ALSO A GOOD INDICATOR THAT WIND SPEEDS WILL BE ON THE INCRS ACROSS MIDWEST THIS MRNG. IN ADDITION QUICK LOOK AT RFD AND ORD ACARS DATA TO CHECK FOR ANY LLWS ABV SFC INVERSION SHOWS WSWLY WINDS ARND 40 KTS AOA FL030. EXPECT WINDS NOW FROM S ARND 10 KTS TO INCRS QUICKLY THIS MRNG AS WX SYS TO NW APCHS...AND SFC HEATING AND WARMER AIR MOVG IN FROM SW ERODE LLVL INVERSION. WINDS EXPECTED TO BE ABOUT DUE SW...SUSTAINED IN 15-20 KT RANGE...BUT WITH FQT GUST TO NR 30 KTS LATE THIS MRNG-AFTN. WIND SPEEDS TO DMNSH A BIT TWD SS...BUT GUSTINESS EXPECTED TO CONT WELL INTO THE EVENING AS TROF ASSD WITH LOW TO N SWEEPS THRU AND TURNS WINDS TO W.

THIS WX SYS WILL RMN STARVED FOR MOISTURE...SO ONLY MID LVL CIGS TO PREVAIL THRU TDY...THEN THINNING TO SCT-BKN MID LVL CLOUDS LATE THIS AFTN. WITH AMPLE MIXING OF AIR THIS MRNG AND TNGT...NO VIS RESTRICTIONS EXPECTED SO CIGS/VIS TO RMN VFR THRU PERIOD.

MERZLOCK

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...GALE WARNING FOR THE SOUTH HALF OF THE OPEN WATERS OF LAKE MICHIGAN FOR THIS AFTERNOON AND TONIGHT. ...SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS FOR THIS AFTERNOON AND TONIGHT. &&

$$

.DISCUSSION FOR MORNING GRIDS/ZONES... 330 AM CST

SYNOPTIC SCALE PATTERN BEGINS THE FCST PD IN A FAST/LOW AMPLITUDE REGIME WITH A CLIPPER-TYPE SHORT WAVE DIGGING INTO THE UPPER MISSISSIPPI VALLEY THIS MORNING AND THEN TRACKING ACROSS THE GREAT LAKES REGION. THIS SYSTEM WILL SPREAD CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS ACROSS THE REGION...BRINGING AN ABRUPT END TO THE RARE DECEMBER SUNSHINE...BUT ANY PCPN ASSOCIATED WITH THE SHORT WAVE WILL REMAIN WELL NORTH OF THE WISCONSIN BORDER. THROUGH THE SHORT TERM...TEMPERATURES WILL REMAIN ABOVE SEASONAL NORMAL LEVELS. WHILE THE GUIDANCE IS TRENDING TOWARD A BIT MORE AMPLITUDE TO THE PATTERN THAN RECENT RUNS HAVE SUGGESTED...ANY SIGNIFICANT COLD AIR WILL REMAIN WELL NORTH OF THE CANADIAN BORDER AS THE NEXT COUPLE SYSTEMS TO APPROACH THE LOCAL AREA WILL BE OF PACIFIC ORIGIN...KEEPING THE REGION UNDER A MODERATE AIRMASS. THROUGH THE WEEKEND...HIGH TEMPERATURES ACROSS THE CWA WILL RANGE FROM NEAR 50 TO THE UPPER 50S...PARTICULARLY ACROSS THE SRN COUNTIES. BY THE WEEKEND...ANOTHER PACIFIC SYSTEM WILL TRACK ACROSS SOUTHCENTRAL CANADA...TURNING FLOW MORE SWLY ALOFT AND SLY AT THE SURFACE...TAPPING SOME GULF MOISTURE. BUT WHILE KEEPING TEMPERATURES MILD...THERE WILL ALSO BE OUR NEXT CHANCE FOR RAIN AS THE GFS IS SUGGESTING AN EXTENDED PERIOD OF STRONG POSITIVE THETA-E ADVECTION...THUS WILL KEEP THE BROADBRUSHED CHANCE RA ACROSS THE REGION.

FOR THE LONGER TERM...THE GFS IS SHOWING GOOD RUN TO RUN CONSISTENCY ON DIGGING A CUT OFF LOW INTO THE DESERT SOUTHWEST EARLY NEXT WEEK. BUT THE LATEST RUN IS TAKING THE UPPER LOW EVEN FARTHER SOUTH...INTO THE SONORA DESERT OF NRN MEXICO BEFORE EJECTING OUT INTO THE SOUTH HIGH PLAINS BY MIDWEEK. THIS SYSTEM WILL BEAR WATCHING AS IT WILL POTENTIALLY BE OUR NEXT MAJOR WEATHER MAKER.

KREIN

&&

.AVIATION DISCUSSION REGARDING 12Z TAFS... 545 AM CST

HIGH PRES OVR SERN U.S. AND LOW PRES CENTER MOVG EWD ALG U.S.-CAN BDR TDY WILL INCRS PRES GRADIENT AND RESULT IN WIND SPEEDS/GUSTS BEING MAIN WX PROBLEM NXT 24 HRS. VIGOROUS SHORT WAVE/IMPULSE IN JET STREAM WIND FIELD/ ASSD WITH LOW PRES TO N WILL MOVE ACRS WRN GRTLKS TDY AIDING INCRS IN SFC WIND SPEEDS. CURRENT SFC ANALYSIS ALSO SHOWS AXIS OF SIG SFC PRES FALLS /FOR THIS TIME OF THE MORNING ANYWAY/ FROM MN ARROWHEAD-NWRN WI-UPR MS VLY. THIS IS ALSO A GOOD INDICATOR THAT WIND SPEEDS WILL BE ON THE INCRS ACROSS MIDWEST THIS MRNG. IN ADDITION QUICK LOOK AT RFD AND ORD ACARS DATA TO CHECK FOR ANY LLWS ABV SFC INVERSION SHOWS WSWLY WINDS ARND 40 KTS AOA FL030. EXPECT WINDS NOW FROM S ARND 10 KTS TO INCRS QUICKLY THIS MRNG AS WX SYS TO NW APCHS...AND SFC HEATING AND WARMER AIR MOVG IN FROM SW ERODE LLVL INVERSION. WINDS EXPECTED TO BE ABOUT DUE SW...SUSTAINED IN 15-20 KT RANGE...BUT WITH FQT GUST TO NR 30 KTS LATE THIS MRNG-AFTN. WIND SPEEDS TO DMNSH A BIT TWD SS...BUT GUSTINESS EXPECTED TO CONT WELL INTO THE EVENING AS TROF ASSD WITH LOW TO N SWEEPS THRU AND TURNS WINDS TO W.

THIS WX SYS WILL RMN STARVED FOR MOISTURE...SO ONLY MID LVL CIGS TO PREVAIL THRU TDY...THEN THINNING TO SCT-BKN MID LVL CLOUDS LATE THIS AFTN. WITH AMPLE MIXING OF AIR THIS MRNG AND TNGT...NO VIS RESTRICTIONS EXPECTED SO CIGS/VIS TO RMN VFR THRU PERIOD.

MERZLOCK

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...GALE WARNING FOR THE SOUTH HALF OF THE OPEN WATERS OF LAKE MICHIGAN FOR THIS AFTERNOON AND TONIGHT. ...SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS FOR THIS AFTERNOON AND TONIGHT. &&

$$

.MORNING UPDATE... LARGE AREA OF CIRRUS MOVING ACROSS THE WABASH AND LOWER OHIO VALLEYS INTO THE FORECAST AREA THIS MORNING...MODELS HAVE PICKED UP ON THIS FEATURE WELL...THOUGH ARE ABOUT 2 TO 3 HOURS TOO SLOW. THEREFORE HAVE USED THE TIMING TOOL WITH THE CURRENT SAT LOOP TO EDIT THE CLOUD GRIDS WITH THE LATEST TRENDS. BROKEN CIRRUS SHIELD SHOULD REACH THE SDF AREA AROUND 1030-11AM...LEX AND BWG AROUND 1230-1 PM EST.

OUTSIDE OF THE OBS SITE AT BWG REGIONAL AIRPORT...WHICH IS MUCH COOLER THAN ALL THE REST DUE TO MICROCLIMATE EFFECTS AS IT IS SHELTERED AND IN THE BOWL TOPOGRAPHY-WISE...ALL ARE RUNNING A FEW DEGREES ABOVE THE FORECAST HOURLY GRIDS...WILL MAKE ADJUST THERE...BUT WITH CIRRUS SHIELD MOVING THINK THAT CURRENT FORECAST HIGHS STILL LOOK GOOD. THOUGH UNSEASONABLY WARM VIRTUALLY NO CHANCE TO APPROACH ANY RECORDS HIGHS...SDF 73(1975)...LEX 69(1984) AND...BWG 71 (1927).

***LATE ADDITION AFTER PREVIOUS AFD WAS SENT: BWG OB SITE HAS RESPOND QUICKLY TO THE FULL SUN AND WARM H850 TEMPS...AND IS NOW AT THE FORECASTED HOURLY GRID VALUE AS OF THE 10 AM OB.

SCHOTT

&&

PREV DISCUSSION... (ISSUED 601 AM EST THU DEC 14 2006)

UPDATE... PATCHY FOG HAS MATERIALIZED IN A FEW SPOTS OVER SRN KY...SO WILL UPDATE FCST TO ADD MENTION OF PATCHY FOG THROUGH 14Z.

CS

PREV DISCUSSION... (ISSUED 210 AM EST THU DEC 14 2006)

SHORT TERM (TODAY-FRIDAY)...

SKIES ARE MOSTLY CLEAR OVER THE REGION AS OF 7Z...ONLY A FEW WISPS OF CIRRUS PRESENT. LATEST ACARS SOUNDINGS AT KSDF SHOWING ~30KTS AT 2KFT AGL...ENOUGH LLWS TO INCLUDE IN TAFS THROUGH MID-MORNING. THIS WIND IS ALSO RESTRICTING FOG FORMATION...ONLY OUR SE COUNTIES WHERE LOW LEVEL WINDS ARE LIGHTER MAY SEE SOME SPOTS OF LIGHT FOG THROUGH DAYBREAK.

UPSTREAM...LARGE AREA OF THICKER HIGH LEVEL CLOUDS ADVANCING RAPIDLY EASTWARD ASSOC WITH LEADING EDGE OF 150KT PACIFIC JET STREAK AND SHORT WAVE TROF OVER DAKOTAS. THESE FEATURES ARE FCST TO SLIDE ESE INTO THE GREAT LAKES BY THIS AFTN...HELPING INCR THE SFC PRES GRADIENT OVER THE REGION. SOUTHERLIES MAY GUST TO NEAR 20KTS OR SO IN OUR CWA TODAY...PER NAM/RUC BOUNDARY LAYER WIND FIELDS. FCST SOUNDINGS INDICATE PLENTY OF SUNSHINE TODAY...THOUGH THOSE HIGH CLOUDS UPSTREAM ARE MOVING IN OUR DIRECTION QUITE QUICKLY...SO WILL INCREASE CLOUD COVER STARTING MID MORNING. OVERALL SKIES SHOULD BE MOSTLY SUNNY...BUT THEY MAY GO TO MORE OF A PARTLY SUNNY CONDITION FOR A PERIOD TODAY DEPENDING ON HOW THICK THE HIGH CLOUDS GET. CONSENSUS OF MOS GUIDANCE SHOWS LOW/MIDDLE 60S TODAY AND THIS SEEMS REASONABLE.

TONIGHT SKIES WILL LIKELY GO PARTLY CLOUDY FOR A WHILE WITH HIGH LEVEL CLOUDS MOVING THOUGH. SOME MID-LEVEL CLOUDS (~700MB) ARE FCST BY THE LATEST NAM TO AFFECT THE REGION BTWN 9-18Z/FRI ASSOC WITH A SECONDARY UPPER SHORTWAVE TROF. THEREFORE HAVE INCREASED CLOUD COVER GRIDS A FEW PERCENTAGE POINTS DURING THIS PERIOD. LATEST GFS ACTUALLY SPITS OUT SOME VERY LIGHT QPF OVER OUR ERN ZONES LATE TONIGHT-FRI MORNING ASSOC WITH THIS FEATURE. LOW LEVELS LOOK TOO DRY FOR ANYTHING MORE THAN A FEW SPRINKLES. 850MB TEMPS FCST TO DROP SLIGHTLY BEHIND THIS TROF...WHICH WILL LIKELY YIELD A 5 DEGREE COOLDOWN FRI AS COMPARED TO THURS. STILL AN MILD DAY FOR MID DECEMBER.

CS

LONG TERM (FRIDAY NIGHT-WEDNESDAY)...

NO SIGNIFICANT CHANCES TO THE LONG TERM AT THIS TIME. RELEVANT PORTIONS OF THE PREVIOUS DISCUSSION BELOW:

SATURDAY...

ACROSS THE LOWER OHIO VALLEY WE WILL REMAIN IN A BRISK WEST TO SOUTHWEST FLOW WITH AN ESPECIALLY TIGHT LOW LEVEL GRADIENT SATURDAY. TEMPERATURES SATURDAY WILL AVERAGE 15 TO 20 DEGREES ABOVE NORMAL FOR THE MIDDLE OF DECEMBER.

SUNDAY THROUGH WEDNESDAY...

THIS IS A LOW CONFIDENCE FORECAST WITH LONG RANGE MODELS OFFERING VARYING SOLUTIONS TO FLOW ACROSS THE UNITED STATES. AT THE BEGINNING OF THIS PERIOD WE FIND A DEEPENING SOUTHERN STREAM UPPER LEVEL TROUGH OVER THE SOUTHWEST PORTION OF THE COUNTRY WITH A NORTHERN STREAM LOW PUSHING EAST JUST NORTH OF THE GREAT LAKES REGION. AN ASSOCIATED SURFACE LOW WILL TRACK ALONG THE CANADIAN BORDER WITH A TRAILING COLD FRONT. THE FIRST QUESTION WILL BE HOW FAR SOUTH THE FRONT WILL DROP BEFORE ENCOUNTERING THE SOUTHWEST FLOW. FOR THE PRESENT TIME WE WILL KEEP THE FRONT NORTH OF THE FORECAST AREA WHICH WILL KEEP THE LAST HALF OF THE WEEKEND DRY. THE SECOND CONCERN WILL BE HOW DEEP THE SOUTHERN STREAM TROUGH WILL DIG INTO THE SOUTHWEST AND TIMING OF THE EJECTION OF THIS SYSTEM INTO THE MID MISSISSIPPI VALLEY. AS A RULE THE MODELS ARE A LITTLE FAST WITH THIS BUT WE WILL CONTINUE TO MENTION PRECIPITATION MOVING INTO THE REGION TUESDAY AS THE TROUGH HEADS EAST. UNDER THE FORE MENTIONED SCENARIO TEMPERATURES WILL REMAIN WELL ABOVE NORMAL WITH HIGHS IN THE 50S AND 60S AND LOWS IN THE 40S. --JA

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$

.MORNING UPDATE... LARGE AREA OF CIRRUS MOVING ACROSS THE WABASH AND LOWER OHIO VALLEYS INTO THE FORECAST AREA THIS MORNING...MODELS HAVE PICKED UP ON THIS FEATURE WELL...THOUGH ARE ABOUT 2 TO 3 HOURS TOO SLOW. THEREFORE HAVE USED THE TIMING TOOL WITH THE CURRENT SAT LOOP TO EDIT THE CLOUD GRIDS WITH THE LATEST TRENDS. BROKEN CIRRUS SHIELD SHOULD REACH THE SDF AREA AROUND 1030-11AM...LEX AND BWG AROUND 1230-1 PM EST.

OUTSIDE OF THE OBS SITE AT BWG REGIONAL AIRPORT...WHICH IS MUCH COOLER THAN ALL THE REST DUE TO MICROCLIMATE EFFECTS AS IT IS SHELTERED AND IN THE BOWL TOPOGRAPHY-WISE...ALL ARE RUNNING A FEW DEGREES ABOVE THE FORECAST HOURLY GRIDS...WILL MAKE ADJUST THERE...BUT WITH CIRRUS SHIELD MOVING THINK THAT CURRENT FORECAST HIGHS STILL LOOK GOOD. THOUGH UNSEASONABLY WARM VIRTUALLY NO CHANCE TO APPROACH ANY RECORDS HIGHS...SDF 73(1975)...LEX 69(1984) AND...BWG 71 (1927).

SCHOTT

&&

PREV DISCUSSION... (ISSUED 601 AM EST THU DEC 14 2006)

UPDATE... PATCHY FOG HAS MATERIALIZED IN A FEW SPOTS OVER SRN KY...SO WILL UPDATE FCST TO ADD MENTION OF PATCHY FOG THROUGH 14Z.

CS

PREV DISCUSSION... (ISSUED 210 AM EST THU DEC 14 2006)

SHORT TERM (TODAY-FRIDAY)...

SKIES ARE MOSTLY CLEAR OVER THE REGION AS OF 7Z...ONLY A FEW WISPS OF CIRRUS PRESENT. LATEST ACARS SOUNDINGS AT KSDF SHOWING ~30KTS AT 2KFT AGL...ENOUGH LLWS TO INCLUDE IN TAFS THROUGH MID-MORNING. THIS WIND IS ALSO RESTRICTING FOG FORMATION...ONLY OUR SE COUNTIES WHERE LOW LEVEL WINDS ARE LIGHTER MAY SEE SOME SPOTS OF LIGHT FOG THROUGH DAYBREAK.

UPSTREAM...LARGE AREA OF THICKER HIGH LEVEL CLOUDS ADVANCING RAPIDLY EASTWARD ASSOC WITH LEADING EDGE OF 150KT PACIFIC JET STREAK AND SHORT WAVE TROF OVER DAKOTAS. THESE FEATURES ARE FCST TO SLIDE ESE INTO THE GREAT LAKES BY THIS AFTN...HELPING INCR THE SFC PRES GRADIENT OVER THE REGION. SOUTHERLIES MAY GUST TO NEAR 20KTS OR SO IN OUR CWA TODAY...PER NAM/RUC BOUNDARY LAYER WIND FIELDS. FCST SOUNDINGS INDICATE PLENTY OF SUNSHINE TODAY...THOUGH THOSE HIGH CLOUDS UPSTREAM ARE MOVING IN OUR DIRECTION QUITE QUICKLY...SO WILL INCREASE CLOUD COVER STARTING MID MORNING. OVERALL SKIES SHOULD BE MOSTLY SUNNY...BUT THEY MAY GO TO MORE OF A PARTLY SUNNY CONDITION FOR A PERIOD TODAY DEPENDING ON HOW THICK THE HIGH CLOUDS GET. CONSENSUS OF MOS GUIDANCE SHOWS LOW/MIDDLE 60S TODAY AND THIS SEEMS REASONABLE.

TONIGHT SKIES WILL LIKELY GO PARTLY CLOUDY FOR A WHILE WITH HIGH LEVEL CLOUDS MOVING THOUGH. SOME MID-LEVEL CLOUDS (~700MB) ARE FCST BY THE LATEST NAM TO AFFECT THE REGION BTWN 9-18Z/FRI ASSOC WITH A SECONDARY UPPER SHORTWAVE TROF. THEREFORE HAVE INCREASED CLOUD COVER GRIDS A FEW PERCENTAGE POINTS DURING THIS PERIOD. LATEST GFS ACTUALLY SPITS OUT SOME VERY LIGHT QPF OVER OUR ERN ZONES LATE TONIGHT-FRI MORNING ASSOC WITH THIS FEATURE. LOW LEVELS LOOK TOO DRY FOR ANYTHING MORE THAN A FEW SPRINKLES. 850MB TEMPS FCST TO DROP SLIGHTLY BEHIND THIS TROF...WHICH WILL LIKELY YIELD A 5 DEGREE COOLDOWN FRI AS COMPARED TO THURS. STILL AN MILD DAY FOR MID DECEMBER.

CS

LONG TERM (FRIDAY NIGHT-WEDNESDAY)...

NO SIGNIFICANT CHANCES TO THE LONG TERM AT THIS TIME. RELEVANT PORTIONS OF THE PREVIOUS DISCUSSION BELOW:

SATURDAY...

ACROSS THE LOWER OHIO VALLEY WE WILL REMAIN IN A BRISK WEST TO SOUTHWEST FLOW WITH AN ESPECIALLY TIGHT LOW LEVEL GRADIENT SATURDAY. TEMPERATURES SATURDAY WILL AVERAGE 15 TO 20 DEGREES ABOVE NORMAL FOR THE MIDDLE OF DECEMBER.

SUNDAY THROUGH WEDNESDAY...

THIS IS A LOW CONFIDENCE FORECAST WITH LONG RANGE MODELS OFFERING VARYING SOLUTIONS TO FLOW ACROSS THE UNITED STATES. AT THE BEGINNING OF THIS PERIOD WE FIND A DEEPENING SOUTHERN STREAM UPPER LEVEL TROUGH OVER THE SOUTHWEST PORTION OF THE COUNTRY WITH A NORTHERN STREAM LOW PUSHING EAST JUST NORTH OF THE GREAT LAKES REGION. AN ASSOCIATED SURFACE LOW WILL TRACK ALONG THE CANADIAN BORDER WITH A TRAILING COLD FRONT. THE FIRST QUESTION WILL BE HOW FAR SOUTH THE FRONT WILL DROP BEFORE ENCOUNTERING THE SOUTHWEST FLOW. FOR THE PRESENT TIME WE WILL KEEP THE FRONT NORTH OF THE FORECAST AREA WHICH WILL KEEP THE LAST HALF OF THE WEEKEND DRY. THE SECOND CONCERN WILL BE HOW DEEP THE SOUTHERN STREAM TROUGH WILL DIG INTO THE SOUTHWEST AND TIMING OF THE EJECTION OF THIS SYSTEM INTO THE MID MISSISSIPPI VALLEY. AS A RULE THE MODELS ARE A LITTLE FAST WITH THIS BUT WE WILL CONTINUE TO MENTION PRECIPITATION MOVING INTO THE REGION TUESDAY AS THE TROUGH HEADS EAST. UNDER THE FORE MENTIONED SCENARIO TEMPERATURES WILL REMAIN WELL ABOVE NORMAL WITH HIGHS IN THE 50S AND 60S AND LOWS IN THE 40S. --JA

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$

.UPDATE... PATCHY FOG HAS MATERIALIZED IN A FEW SPOTS OVER SRN KY...SO WILL UPDATE FCST TO ADD MENTION OF PATCHY FOG THROUGH 14Z.

CS

&&

.PREV DISCUSSION... (ISSUED 210 AM EST THU DEC 14 2006)

SHORT TERM (TODAY-FRIDAY)...

SKIES ARE MOSTLY CLEAR OVER THE REGION AS OF 7Z...ONLY A FEW WISPS OF CIRRUS PRESENT. LATEST ACARS SOUNDINGS AT KSDF SHOWING ~30KTS AT 2KFT AGL...ENOUGH LLWS TO INCLUDE IN TAFS THROUGH MID-MORNING. THIS WIND IS ALSO RESTRICTING FOG FORMATION...ONLY OUR SE COUNTIES WHERE LOW LEVEL WINDS ARE LIGHTER MAY SEE SOME SPOTS OF LIGHT FOG THROUGH DAYBREAK.

UPSTREAM...LARGE AREA OF THICKER HIGH LEVEL CLOUDS ADVANCING RAPIDLY EASTWARD ASSOC WITH LEADING EDGE OF 150KT PACIFIC JET STREAK AND SHORT WAVE TROF OVER DAKOTAS. THESE FEATURES ARE FCST TO SLIDE ESE INTO THE GREAT LAKES BY THIS AFTN...HELPING INCR THE SFC PRES GRADIENT OVER THE REGION. SOUTHERLIES MAY GUST TO NEAR 20KTS OR SO IN OUR CWA TODAY...PER NAM/RUC BOUNDARY LAYER WIND FIELDS. FCST SOUNDINGS INDICATE PLENTY OF SUNSHINE TODAY...THOUGH THOSE HIGH CLOUDS UPSTREAM ARE MOVING IN OUR DIRECTION QUITE QUICKLY...SO WILL INCREASE CLOUD COVER STARTING MID MORNING. OVERALL SKIES SHOULD BE MOSTLY SUNNY...BUT THEY MAY GO TO MORE OF A PARTLY SUNNY CONDITION FOR A PERIOD TODAY DEPENDING ON HOW THICK THE HIGH CLOUDS GET. CONSENSUS OF MOS GUIDANCE SHOWS LOW/MIDDLE 60S TODAY AND THIS SEEMS REASONABLE.

TONIGHT SKIES WILL LIKELY GO PARTLY CLOUDY FOR A WHILE WITH HIGH LEVEL CLOUDS MOVING THOUGH. SOME MID-LEVEL CLOUDS (~700MB) ARE FCST BY THE LATEST NAM TO AFFECT THE REGION BTWN 9-18Z/FRI ASSOC WITH A SECONDARY UPPER SHORTWAVE TROF. THEREFORE HAVE INCREASED CLOUD COVER GRIDS A FEW PERCENTAGE POINTS DURING THIS PERIOD. LATEST GFS ACTUALLY SPITS OUT SOME VERY LIGHT QPF OVER OUR ERN ZONES LATE TONIGHT-FRI MORNING ASSOC WITH THIS FEATURE. LOW LEVELS LOOK TOO DRY FOR ANYTHING MORE THAN A FEW SPRINKLES. 850MB TEMPS FCST TO DROP SLIGHTLY BEHIND THIS TROF...WHICH WILL LIKELY YIELD A 5 DEGREE COOLDOWN FRI AS COMPARED TO THURS. STILL AN MILD DAY FOR MID DECEMBER.

CS

LONG TERM (FRIDAY NIGHT-WEDNESDAY)...

NO SIGNIFICANT CHANCES TO THE LONG TERM AT THIS TIME. RELEVANT PORTIONS OF THE PREVIOUS DISCUSSION BELOW:

SATURDAY...

ACROSS THE LOWER OHIO VALLEY WE WILL REMAIN IN A BRISK WEST TO SOUTHWEST FLOW WITH AN ESPECIALLY TIGHT LOW LEVEL GRADIENT SATURDAY. TEMPERATURES SATURDAY WILL AVERAGE 15 TO 20 DEGREES ABOVE NORMAL FOR THE MIDDLE OF DECEMBER.

SUNDAY THROUGH WEDNESDAY...

THIS IS A LOW CONFIDENCE FORECAST WITH LONG RANGE MODELS OFFERING VARYING SOLUTIONS TO FLOW ACROSS THE UNITED STATES. AT THE BEGINNING OF THIS PERIOD WE FIND A DEEPENING SOUTHERN STREAM UPPER LEVEL TROUGH OVER THE SOUTHWEST PORTION OF THE COUNTRY WITH A NORTHERN STREAM LOW PUSHING EAST JUST NORTH OF THE GREAT LAKES REGION. AN ASSOCIATED SURFACE LOW WILL TRACK ALONG THE CANADIAN BORDER WITH A TRAILING COLD FRONT. THE FIRST QUESTION WILL BE HOW FAR SOUTH THE FRONT WILL DROP BEFORE ENCOUNTERING THE SOUTHWEST FLOW. FOR THE PRESENT TIME WE WILL KEEP THE FRONT NORTH OF THE FORECAST AREA WHICH WILL KEEP THE LAST HALF OF THE WEEKEND DRY. THE SECOND CONCERN WILL BE HOW DEEP THE SOUTHERN STREAM TROUGH WILL DIG INTO THE SOUTHWEST AND TIMING OF THE EJECTION OF THIS SYSTEM INTO THE MID MISSISSIPPI VALLEY. AS A RULE THE MODELS ARE A LITTLE FAST WITH THIS BUT WE WILL CONTINUE TO MENTION PRECIPITATION MOVING INTO THE REGION TUESDAY AS THE TROUGH HEADS EAST. UNDER THE FORE MENTIONED SCENARIO TEMPERATURES WILL REMAIN WELL ABOVE NORMAL WITH HIGHS IN THE 50S AND 60S AND LOWS IN THE 40S. --JA

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$

.SHORT TERM (TODAY-FRIDAY)...

SKIES ARE MOSTLY CLEAR OVER THE REGION AS OF 7Z...ONLY A FEW WISPS OF CIRRUS PRESENT. LATEST ACARS SOUNDINGS AT KSDF SHOWING ~30KTS AT 2KFT AGL...ENOUGH LLWS TO INCLUDE IN TAFS THROUGH MID-MORNING. THIS WIND IS ALSO RESTRICTING FOG FORMATION...ONLY OUR SE COUNTIES WHERE LOW LEVEL WINDS ARE LIGHTER MAY SEE SOME SPOTS OF LIGHT FOG THROUGH DAYBREAK.

UPSTREAM...LARGE AREA OF THICKER HIGH LEVEL CLOUDS ADVANCING RAPIDLY EASTWARD ASSOC WITH LEADING EDGE OF 150KT PACIFIC JET STREAK AND SHORT WAVE TROF OVER DAKOTAS. THESE FEATURES ARE FCST TO SLIDE ESE INTO THE GREAT LAKES BY THIS AFTN...HELPING INCR THE SFC PRES GRADIENT OVER THE REGION. SOUTHERLIES MAY GUST TO NEAR 20KTS OR SO IN OUR CWA TODAY...PER NAM/RUC BOUNDARY LAYER WIND FIELDS. FCST SOUNDINGS INDICATE PLENTY OF SUNSHINE TODAY...THOUGH THOSE HIGH CLOUDS UPSTREAM ARE MOVING IN OUR DIRECTION QUITE QUICKLY...SO WILL INCREASE CLOUD COVER STARTING MID MORNING. OVERALL SKIES SHOULD BE MOSTLY SUNNY...BUT THEY MAY GO TO MORE OF A PARTLY SUNNY CONDITION FOR A PERIOD TODAY DEPENDING ON HOW THICK THE HIGH CLOUDS GET. CONSENSUS OF MOS GUIDANCE SHOWS LOW/MIDDLE 60S TODAY AND THIS SEEMS REASONABLE.

TONIGHT SKIES WILL LIKELY GO PARTLY CLOUDY FOR A WHILE WITH HIGH LEVEL CLOUDS MOVING THOUGH. SOME MID-LEVEL CLOUDS (~700MB) ARE FCST BY THE LATEST NAM TO AFFECT THE REGION BTWN 9-18Z/FRI ASSOC WITH A SECONDARY UPPER SHORTWAVE TROF. THEREFORE HAVE INCREASED CLOUD COVER GRIDS A FEW PERCENTAGE POINTS DURING THIS PERIOD. LATEST GFS ACTUALLY SPITS OUT SOME VERY LIGHT QPF OVER OUR ERN ZONES LATE TONIGHT-FRI MORNING ASSOC WITH THIS FEATURE. LOW LEVELS LOOK TOO DRY FOR ANYTHING MORE THAN A FEW SPRINKLES. 850MB TEMPS FCST TO DROP SLIGHTLY BEHIND THIS TROF...WHICH WILL LIKELY YIELD A 5 DEGREE COOLDOWN FRI AS COMPARED TO THURS. STILL AN MILD DAY FOR MID DECEMBER.

CS

.LONG TERM (FRIDAY NIGHT-WEDNESDAY)...

NO SIGNIFICANT CHANCES TO THE LONG TERM AT THIS TIME. RELEVANT PORTIONS OF THE PREVIOUS DISCUSSION BELOW:

SATURDAY...

ACROSS THE LOWER OHIO VALLEY WE WILL REMAIN IN A BRISK WEST TO SOUTHWEST FLOW WITH AN ESPECIALLY TIGHT LOW LEVEL GRADIENT SATURDAY. TEMPERATURES SATURDAY WILL AVERAGE 15 TO 20 DEGREES ABOVE NORMAL FOR THE MIDDLE OF DECEMBER.

SUNDAY THROUGH WEDNESDAY...

THIS IS A LOW CONFIDENCE FORECAST WITH LONG RANGE MODELS OFFERING VARYING SOLUTIONS TO FLOW ACROSS THE UNITED STATES. AT THE BEGINNING OF THIS PERIOD WE FIND A DEEPENING SOUTHERN STREAM UPPER LEVEL TROUGH OVER THE SOUTHWEST PORTION OF THE COUNTRY WITH A NORTHERN STREAM LOW PUSHING EAST JUST NORTH OF THE GREAT LAKES REGION. AN ASSOCIATED SURFACE LOW WILL TRACK ALONG THE CANADIAN BORDER WITH A TRAILING COLD FRONT. THE FIRST QUESTION WILL BE HOW FAR SOUTH THE FRONT WILL DROP BEFORE ENCOUNTERING THE SOUTHWEST FLOW. FOR THE PRESENT TIME WE WILL KEEP THE FRONT NORTH OF THE FORECAST AREA WHICH WILL KEEP THE LAST HALF OF THE WEEKEND DRY. THE SECOND CONCERN WILL BE HOW DEEP THE SOUTHERN STREAM TROUGH WILL DIG INTO THE SOUTHWEST AND TIMING OF THE EJECTION OF THIS SYSTEM INTO THE MID MISSISSIPPI VALLEY. AS A RULE THE MODELS ARE A LITTLE FAST WITH THIS BUT WE WILL CONTINUE TO MENTION PRECIPITATION MOVING INTO THE REGION TUESDAY AS THE TROUGH HEADS EAST. UNDER THE FORE MENTIONED SCENARIO TEMPERATURES WILL REMAIN WELL ABOVE NORMAL WITH HIGHS IN THE 50S AND 60S AND LOWS IN THE 40S. --JA

&&

.LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. &&

$$

.UPDATE... WV IMAGERY INDICATED A LEAD SHRTWV/VORT AXIS AHEAD OF A MID LVL LOW INTO NW MN. RADARS INDICATED A BROAD AREA OF PCPN MOVING FROM NW AND CNTRL WI INTO UPPER MI SUPPORTED BY 290K ISENTROPIC LIFT AHEAD OF THE SHRTWV. UPSTREAM REPORTS OVER NRN WI AND NE MN INDICATED AREAS OF FREEZING RAIN ALONG WITH SLEET AND SNOW. MORNING AREA TAMDAR SNDGS INDICATED A SUBSTANTIAL WARM LYR( TO AROUND 3C) BTWN THE SFC AND 850 MB THAT WAS ALSO DRY. EVAPORATIVE COOLING HAS BEEN STRONG ENOUGH TO LOWER THE TEMP PROFILE FOR SOME SLEET OR SNOW ALONG WITH FREEZING RAIN.

RADAR TRENDS AND MDLS SUGGEST AREA OF PCPN WILL SWEEP THROUGH UPPER MI THIS AFTERNOON. INLAND LOCATIONS THAT FELL INTO THE 20S LAST NIGHT HAVE REBOUNDED SLOWLY ENOUGH OR HAVE COLD ENOUGH ROAD SURFACES FOR ICING ON HIGHWAYS TIL MID AFTERNOON WITH SFC TEMPS SHOULD CLIMB INTO THE MID AND UPPER 30S. SO...WINTER WX ADVY WAS ISSUED(IN EFFECT UNTIL 19Z). LOCATIONS NEAR LAKE SUPERIOR AND OVER THE E HALF OF THE CWA HAVE BEEN WARM ENOUGH(IN THE MID 30S) SO THAT MAINLY RAIN OR A RAIN/SNOW MIX IS EXPECTED. ANY WET SNOW ACCUMULATIONS OVER HIGHER TERRAIN IN W UPR MI SHOULD AMOUNT TO LESS THAN AN INCH...GIVEN MIX OF PCPN TYPES EXPECTED AND RELATIVELY LIGHT QPF AMOUNTS...GENERALLY AOB 0.10 INCH.

&&

.PREV DISCUSSION...ISSUED 545 AM EST THU DEC 15 2006

CONCERNS FOCUS MAINLY ON PCPN TYPE/TIMING TODAY THEN CHCS OF LES TONIGHT INTO FRIDAY.

09Z WATER VAPOR LOOP SHOWS A STRONG SHORTWAVE DIGGING ESE THROUGH ERN ND IN NEARLY ZONAL FLOW FROM THE PACIFIC ACROSS THE NORTHERN CONUS. UPR DIV IN LEFT EXIT REGION OF 140KT 250 MB PACIFIC JET NOSING INTO THE PLAINS AND SOME ELEVATED INSTABILITY RESULTED IN A FEW LIGHTNING STRIKES IN DEVELOPING 700-600 MB FGEN PCPN BAND WHICH IS NOW LIFTING E INTO MN.

TODAY...GIVEN MORE AMPLIFIED NATURE OF SYSTEM ON WATER VAPOR LOOP AND TRACK OF SFC LOW THUS FAR FAR HAVE SIDED WITH GFS MODEL SOLN WHICH SEEMS TO HAVE BEST HANDLE ON SYSTEM. PRES FALLS AHEAD OF SFC LOW WOULD SUGGEST A SLIGHTLY S OF E TRACK OF SYSTEM WHICH AGREES WELL WITH GFS SOLN. WITH MORE AMPLIFIED SYSTEM...MODELS HAVE TRENDED SLOWER EACH RUN WITH ARRIVAL OF FGEN PCPN BAND BUT ALL MODELS SUGGEST A HIGH CERTAINTY OF PCPN SO HAVE BUMPED UP POPS TO CATEGORICAL FOR THE ENTIRE CWFA. 06Z MODELS RUNS WOULD SUGGEST PCPN TO REACH WRN COUNTIES BY 14Z AND THEN CENTRAL COUNTIES 16-18Z AND ERN COUNTIES AFTER 18Z. WITH RELATIVELY DRY SNDGS AHEAD OF SYSTEM AND FCST LOW WET-BULB ZERO HGTS...STILL KEPT A MENTION OF SNOW WITH RAIN OVER THE WEST HALF OF FCST AREA TODAY. THE EAST HALF LOOKS MORE LIKE RAIN WITH THE LATER ARRIVAL OF PCPN AND INITIAL SRLY FLOW OFF THE WARMER WATERS OF LAKE MI. ANY SNOW ACCUMULATION LOOKS MINIMAL AT ANY RATE AS FGEN BAND SHOULD MOVE THROUGH QUICKLY.

TONIGHT INTO FRI...WINDS BEGIN TO SWING AROUND MORE NORTHWESTERLY...ALLOWING FOR SOME POSSIBLE LAKE ENHANCED PRECIPITATION AS 850MB TEMPS FALL FROM -4/-5C TO -6 TO -8C. CAA ALONG WITH POSSIBLE ENHANCEMENT FROM TRAILING NRN MANITOBA SHORTWAVE COULD RESULT IN AN INCH OR TWO OF LES. CONVERGENT NW FLOW WOULD FAVOR ONTONAGON THROUGH THE KEWEENAW AND ALGER-LUCE AND NRN SCHOOLCRAFT COUNTIES FOR SNOW CHCS. ANOTHER INCH OR TWO OF SNOW IS POSSIBLE FRIDAY MORNING WITH CONVERGENT NW FLOW...BUT THEN FLOW BECOMES SHARPLY ANTICYCLONIC BY AFTERNOON AND BACKS W BY LATE IN DAY WHICH WOULD SHUT OFF LES.

FRIDAY NIGHT LOOKS DRY WITH AMPLIFIED RIDGE MOVING OVER THE AREA. WAA/ISENTROPIC LIFT AHEAD OF YET ANOTHER PACIFIC SYSTEM FCST TO TRACK ACROSS SRN CANADA COULD BRING A CHC OF LIGHT RAIN TO THE FCST AREA ON SAT. HOWEVER...MORE NRLY TRACK OF LOW COMPARED TO TODAY`S SYSTEM WOULD SUGGEST LESS OF AN OPPORTUNITY FOR MEASURABLE PCPN AS MODEL CONSENSUS QPF FIELDS SUGGEST.

&&

.MQT WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR MIZ001>005-009>012-084. &&

$$

JLB(UPDATE) VOSS(PREV DISC)

.DISCUSSION...

&&

.PREV DISCUSSION... /ISSUED 335 PM CST FRI DEC 15 2006/

DISCUSSION... SURFACE RIDGE OVER THE EASTERN CWA ATTM. WITH NO CLEARING TODAY...HIGH TEMPERATURES HAVE STRUGGLED TO REACH THE LOWER 30S. LITTLE WILL CHANGE IN THE WAY OF CLOUDINESS TONIGHT WITH LOW/MID LEVEL WAA OCCURRING ALONG WITH INCREASING MID LEVEL CLOUDINESS. THIS SHOULD PREVENT OVERNIGHT TEMPERATURES FROM DROPPING TOO MUCH. THIS SHOULD ALSO HELP IN KEEP FOG FROM BECOMING WIDESPREAD AS IT WAS TO OUR WEST THIS MORNING. THE FORECAST THROUGH EARLY NEXT WEEK STILL DOESN`T SHOW MUCH IN THE WAY OF ANY SIGNIFICANT LOW PRESSURE SYSTEMS OR PRECIPITATION. ONE AREA OF CONCERN IS SUNDAY AFTERNOON AND NIGHT. THE GFS SINGLE RUN IS SHOWING A STRONGER SURFACE SYSTEM PASSING JUST SOUTH OF THE CWA SUNDAY NIGHT WITH SATURATION AND PRECIPITATION OVER US. THE GFS ENSEMBLE PROBABILITY POPS HAVE INCREASED SIGNIFICANTLY OVER THOSE SEEN YESTERDAY. HOWEVER...SINCE THIS IS A SINGLE MODEL ENSEMBLE...I`M A LITTLE LEARY OF JUMPING TOO HARD ON THE CHANCE OF PRECIPITATION. THE 15Z 21 MEMBER SREF HAS SOME LIGHT PRECIPITATION DEVELOPING DURING THIS PERIOD AS WELL...ESPECIALLY ACROSS CENTRAL MN. THE NAM-WRF INDICATES SATURATION BUT NO PRECIPITATION AND WE KNOW FROM PAST EXPERIENCE THAT THIS CAN BE WRONG. THE ONE SOLUTION THAT FAVORS KEEPING DRY WEATHER INTO MONDAY IS THE 12Z ARW WRF. ONE ITEM OF INTEREST IS THAT WE ARE IN THE RIGHT ENTRANCE REGION OF A 180 KNOT JET LOCATED OVER NORTHERN LAKE SUPERIOR. FOR NOW... COLLABORATION HAS YIELDED SOME LOW CHANCE POPS PASSING ACROSS THE CWA SUNDAY AFTERNOON AND EVENING. THE PERIOD MONDAY THROUGH FRIDAY IS FORECAST TO BE DRY WITH HIGHS AND LOWS PROGGED TO BE FROM 5 TO 8 DEGREES ABOVE NORMAL. A STORM SYSTEM WILL BE PASSING SOUTH OF US DURING THE WEDNESDAY-THURSDAY TIME FRAME. THE GFS AND ECMWF HAVE BEEN TRENDING TO THE NORTHEAST WITH THIS SYSTEM WITH PRECIPITATION NOW PROGGED JUST TO OUR SOUTH. THIS IS DEFINITELY A FEATURE WE WILL HAVE TO KEEP AN EYE ON.

&&

.AVIATION...FOR 00Z TAF CYCLE. TRICKY AVIATION FORECAST THROUGH THE NEXT 12 TO 15 HOURS. CURRENT SATELLITE LOOP SHOWS BLANKET OF ALTO/CIRO STRATUS WITH MID LEVEL WAA. SFC RIDGE EXTENDS OVER WESTERN WISCONSIN AND LIGHT FLOW HAS SOME LOW STRATUS TRAPPED WITHIN. OBSERVATIONS INDICATE STRATUS BREAKING UP IN CENTRAL MN WHERE TIGHTER GRDT IS MOVING IN AND EXPECT THIS TO BE THE TREND NEAR MSP/STC THRU THE EVE. TAMDAR SOUNDINGS FROM RECENT LANDING AIRCRAFT AT MSP SHOW LOW LEVEL SATURATED LAYER TO BE FAIRLY THIN AS WELL. AS FOR WESTERN WISCONSIN LIGHTER FLOW SHOULD ALLOW STRATUS TO REGENERATE AND FILL IN OVERNIGHT. SOME OF THIS MAY SPILL OVER TO MSP/STC NEAR DAWN. REALLY GOING ON EXPERIENCE AS OPPOSED TO ANY GUIDANCE ON THE LOW CLOUDS TONIGHT AS MODELS HAVE HAD POOR HANDLE ON THE LOWER MOISTURE PROFILE. WINDS WILL BE SOUTHEAST SWINGING TO SOUTHWEST SATURDAY MORNING AND THEN WESTERLY BY AFTERNOON WITH THE PASSAGE OF A COLD FRONT. ANY LOW CLOUDS RESIDING AFTER DAWN SHOULD ERODE BY LATE MORNING.

.MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. &&

$$

RAH/MTF

.DISCUSSION...

GOING FORECAST IN PRETTY GOOD SHAPE THIS MORNING. MAIN PROBLEM TODAY WILL BE TEMPERATURES AND WIND. FIRST THE WIND. GOOD 4-5 MB 3-HR PRES RISES NOTED MOVING SEWD INTO THE NORTHERN PLAINS FROM SOUTHERN CANADA. THIS IS EXPECTED TO CONT TO TRACK TO THE SE EVENTUALLY THRU NORTHERN IOWA BY THIS EVENING. LOW TO MID LEVEL FLOW IS EXPECTED TO INCREASE THIS AFTN OVER THE NORTHERN CWA AS STRONG UPPER LEVEL JET CROSSES THE NORTHERN PLAINS. UNIDIRECTIONAL FLOW THROUGH A DEEP LAYER WILL PROMOTE GOOD MOMENTUM TRANSFER DOWNWARD THROUGH THE ATMOSPHERE WHICH HAS THE POTENTIAL TO ALLOW FOR WIND ADVISORY CRITERIA TO BE MET ACROSS THE NORTHERN CWA. MAIN NEGATIVE FACTOR ATTM IS LESS THAN IDEAL LOW LEVEL LAPSE RATES. THUS WITH THE BEST PRES ADVECTION GOING JUST TO OUR NORTH AND MARGINALLY FAVORABLE LOW LEVEL LAPSE RATES...WILL HOLD OFF ON ADVISORY FOR NOW.

VERY WARM START TO THE DAY ACROSS THE CWA WITH A GOOD MID LEVEL CLOUD DECK OVERHEAD EARLY THIS MORNING. SOME WEAK CAA IS EXPECTED OVER THE AREA TODAY WITH H85 TMPS FALLING INTO THE MID SINGLE DIGITS ABOVE ZERO NORTH TO AROUND 10 SOUTH. ALTHOUGH WE SHOULD SEE FAIRLY GOOD MIXING TODAY...LOW LEVEL LAPSE RATES DO NOT APPEAR DRY ADIABATIC FROM FORECAST SOUNDINGS AND STRAIGHT MIXING FROM H85 DOES NOT SEEM POSSIBLE TDY WHICH WOULD BE NEEDED TO ACHIEVE VERY WARM MET GUIDANCE. NEVERTHELESS...WITH CLOUDS DEPARTING THE NORTHERN CWA TODAY DID INCREASE TMPS FROM THE PLATTE RIVER NORTH TO NEAR MAV GUIDANCE WHICH IS STILL IN THE RECORD CAT FOR OMA...BUT A LITTLE SHORT OF THE 64 NEEDED AT KOFK. OTHERWISE PRETTY MUCH LEFT TMPS ALONE IN THE SOUTH WHERE CLDS WILL HANG ON LONGER.

NEW ZFP/GRIDS ALREADY OUT.

BOUSTEAD

&&

.PREV DISCUSSION... /ISSUED 252 AM CST THU DEC 14 2006/

DISCUSSION... FORECAST CHALLENGES CONTINUE TO CENTER AROUND TEMPERATURES OVER THE NEXT SEVERAL DAYS AND PCPN CHANCES EARLY NEXT WEEK.

A FEW SPRINKLES CONTINUE TO MOVE ACROSS NORTHEASTERN NEBRASKA THIS MORNING DUE TO LARGE SCALE ASCENT IN ASSOCIATION WITH MID LEVEL SHORTWAVE MOVING SOUTHEAST ACROSS SOUTHERN SOUTH DAKOTA. UPPER LEVEL DIVERGENCE ALSO INCREASED ACROSS THE FORECAST AREA LATE LAST EVENING ON NOSE OF 140KT 250MB JET NUDGING IN FROM THE NORTHWEST. EXPECT THIS LARGE SCALE ASCENT TO MOVE EWD OVER NEXT SEVERAL HOURS...ENDING PCPN FROM WEST TO EAST NEAR SUNRISE AS SHORTWAVE ENERGY SHIFTS EAST INTO SRN MN/NRN IA. REGIONAL PROFILERS AND LATEST KOMA ACARS DATA SHOWS AROUND 45KTS AROUND 900MB UP TO 850MB. SFC TROF MOVING THROUGH ERN NEB HAS ALLOWED QUITE A BIT OF MIXING TO OCCUR EARLY THIS MORNING...ESPECIALLY ACROSS EAST CENTRAL NEB WHERE TEMPS HAVE RISEN INTO THE LOWER 50S IN SOME LOCATIONS BY 2AM. COLD AIR ADVECTION IS CURRENTLY UNDERWAY ACROSS NORTHEASTERN NEB WHERE NELIGH PROFILER HAS COME AROUND TO THE NORTHWEST AT 850MB. THIS CAA SHOULD PLAY HAVOC ON HIGH TEMPS TODAY. WE CONTINUE TO UNDERCUT GUIDANCE WITH CAA IN MIND. EVEN SO...FORECAST TEMPS WL STILL BE NEAR OR ABOVE RECORDS AT OMA/57 IN 1998 AND AT LNK/61 IN 1888. GOOD MIXING POTENTIAL AND NEARLY 50KTS AT 850MB WL MAKE FOR BORDERLINE WIND ADVISORY CRITERIA ACROSS NORTHEASTERN NEB AND WEST CENTRAL IOWA FOR A FEW HOURS TODAY. THINK CORE OF STRONG WINDS WILL MIX OUT TO OUR NORTH AND EAST AND THEREFORE HAVE HELD OFF ON ANY ADVISORY...BUT IT MIGHT BE VERY CLOSE FOR A FEW HOURS.

STRONG WARM AIR ADVECTION RESUMES TO OUR WEST OVERNIGHT TONIGHT AND MOVES EWD THRU THE MORNING HOURS AS UPPER RIDGE BUILDS OVER THE HIGH PLAINS AND LOW LEVEL FLOW TURNS SOUTHERLY AHEAD OF LOW PRESSURE MOVING ACROSS SOUTHERN CANADA. BOTH GFS AND NAM ARE FORECASTING +10 TO +12C RESPECTIVELY OVER OMAHA BY 00Z SAT. WITH MORE OF A SOUTHERLY WIND...HAVE DOUBTS WE WILL APPROACH FULL MIXING POTENTIAL. HAVE KNOCKED DOWN HIGHS JUST A LITTLE BUT AM STILL OVERSHOOTING GUIDANCE. COULD BE CLOSE TO RECORDS ONCE AGAIN (64 AT LNK/61 AT OMA/64 AT OFK).

COLD FRONT MOVES OUT OF THE DAKOTAS AND THROUGH THE FORECAST AREA LATE FRIDAY NIGHT/EARLY SATURDAY MORNING AND MUCH COOLER AIR BEHIND THIS FEATURE SETTLES IN FOR THE WEEKEND. INCREASING VERTICAL ASCENT AHEAD OF SHORTWAVE ENERGY MOVING OUT OF COLORADO ALONG WITH MID LEVEL FRONOTOGENETICAL FORCING COULD BE ENOUGH TO SUPPORT PCPN BAND ACROSS WESTERN NEBRASKA LATE SUNDAY NIGHT. EASTERN EXTENT OF BAND WOULD LIKELY BE JUST TO THE WEST OF THE FORECAST AREA AS BOTH 00Z GFS AND NAM INDICATE...BUT THIS WILL CERTAINLY WARRANT WATCHING FOR ANY EWD PROGRESSION IN SUCCESSIVE MODEL RUNS..

UPPER TROF DIGS ACROSS THE WESTERN CONUS EARLY NEXT WEEK WITH A SPLIT FLOW REGIME AND MAIN LOW MOVING TO OUR SOUTH AND ANOTHER WAVE FORMING ACROSS THE NRN PLAINS. 00Z ECMWF AND GFS ARE IN GENERAL AGREEMENT WITH MAIN CLOSED LOW MOVING ACROSS THE SOUTHERN CONUS. HAVE NOT MADE ANY CHANGES TO THE EXTENDED FORECAST AS DAY SHIFT WILL FURTHER EXAMINE.

GRIFFIS

&&

.OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE.

&&

$$

.DISCUSSION... FORECAST CHALLENGES CONTINUE TO CENTER AROUND TEMPERATURES OVER THE NEXT SEVERAL DAYS AND PCPN CHANCES EARLY NEXT WEEK.

A FEW SPRINKLES CONTINUE TO MOVE ACROSS NORTHEASTERN NEBRASKA THIS MORNING DUE TO LARGE SCALE ASCENT IN ASSOCIATION WITH MID LEVEL SHORTWAVE MOVING SOUTHEAST ACROSS SOUTHERN SOUTH DAKOTA. UPPER LEVEL DIVERGENCE ALSO INCREASED ACROSS THE FORECAST AREA LATE LAST EVENING ON NOSE OF 140KT 250MB JET NUDGING IN FROM THE NORTHWEST. EXPECT THIS LARGE SCALE ASCENT TO MOVE EWD OVER NEXT SEVERAL HOURS...ENDING PCPN FROM WEST TO EAST NEAR SUNRISE AS SHORTWAVE ENERGY SHIFTS EAST INTO SRN MN/NRN IA. REGIONAL PROFILERS AND LATEST KOMA ACARS DATA SHOWS AROUND 45KTS AROUND 900MB UP TO 850MB. SFC TROF MOVING THROUGH ERN NEB HAS ALLOWED QUITE A BIT OF MIXING TO OCCUR EARLY THIS MORNING...ESPECIALLY ACROSS EAST CENTRAL NEB WHERE TEMPS HAVE RISEN INTO THE LOWER 50S IN SOME LOCATIONS BY 2AM. COLD AIR ADVECTION IS CURRENTLY UNDERWAY ACROSS NORTHEASTERN NEB WHERE NELIGH PROFILER HAS COME AROUND TO THE NORTHWEST AT 850MB. THIS CAA SHOULD PLAY HAVOC ON HIGH TEMPS TODAY. WE CONTINUE TO UNDERCUT GUIDANCE WITH CAA IN MIND. EVEN SO...FORECAST TEMPS WL STILL BE NEAR OR ABOVE RECORDS AT OMA/57 IN 1998 AND AT LNK/61 IN 1888. GOOD MIXING POTENTIAL AND NEARLY 50KTS AT 850MB WL MAKE FOR BORDERLINE WIND ADVISORY CRITERIA ACROSS NORTHEASTERN NEB AND WEST CENTRAL IOWA FOR A FEW HOURS TODAY. THINK CORE OF STRONG WINDS WILL MIX OUT TO OUR NORTH AND EAST AND THEREFORE HAVE HELD OFF ON ANY ADVISORY...BUT IT MIGHT BE VERY CLOSE FOR A FEW HOURS.

STRONG WARM AIR ADVECTION RESUMES TO OUR WEST OVERNIGHT TONIGHT AND MOVES EWD THRU THE MORNING HOURS AS UPPER RIDGE BUILDS OVER THE HIGH PLAINS AND LOW LEVEL FLOW TURNS SOUTHERLY AHEAD OF LOW PRESSURE MOVING ACROSS SOUTHERN CANADA. BOTH GFS AND NAM ARE FORECASTING +10 TO +12C RESPECTIVELY OVER OMAHA BY 00Z SAT. WITH MORE OF A SOUTHERLY WIND...HAVE DOUBTS WE WILL APPROACH FULL MIXING POTENTIAL. HAVE KNOCKED DOWN HIGHS JUST A LITTLE BUT AM STILL OVERSHOOTING GUIDANCE. COULD BE CLOSE TO RECORDS ONCE AGAIN (64 AT LNK/61 AT OMA/64 AT OFK).

COLD FRONT MOVES OUT OF THE DAKOTAS AND THROUGH THE FORECAST AREA LATE FRIDAY NIGHT/EARLY SATURDAY MORNING AND MUCH COOLER AIR BEHIND THIS FEATURE SETTLES IN FOR THE WEEKEND. INCREASING VERTICAL ASCENT AHEAD OF SHORTWAVE ENERGY MOVING OUT OF COLORADO ALONG WITH MID LEVEL FRONOTOGENETICAL FORCING COULD BE ENOUGH TO SUPPORT PCPN BAND ACROSS WESTERN NEBRASKA LATE SUNDAY NIGHT. EASTERN EXTENT OF BAND WOULD LIKELY BE JUST TO THE WEST OF THE FORECAST AREA AS BOTH 00Z GFS AND NAM INDICATE...BUT THIS WILL CERTAINLY WARRANT WATCHING FOR ANY EWD PROGRESSION IN SUCCESSIVE MODEL RUNS..

UPPER TROF DIGS ACROSS THE WESTERN CONUS EARLY NEXT WEEK WITH A SPLIT FLOW REGIME AND MAIN LOW MOVING TO OUR SOUTH AND ANOTHER WAVE FORMING ACROSS THE NRN PLAINS. 00Z ECMWF AND GFS ARE IN GENERAL AGREEMENT WITH MAIN CLOSED LOW MOVING ACROSS THE SOUTHERN CONUS. HAVE NOT MADE ANY CHANGES TO THE EXTENDED FORECAST AS DAY SHIFT WILL FURTHER EXAMINE.

&&

.OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. &&

$$

GRIFFIS

.DISCUSSION... FORECAST CHALLENGES CONTINUE TO CENTER AROUND TEMPERATURES OVER THE NEXT SEVERAL DAYS AND PCPN CHANCES EARLY NEXT WEEK.

A FEW SPRINKLES CONTINUE TO MOVE ACROSS NORTHEASTERN NEBRASKA THIS MORNING DUE TO LARGE SCALE ASCENT IN ASSOCIATION WITH MID LEVEL SHORTWAVE MOVING SOUTHEAST ACROSS SOUTHERN SOUTH DAKOTA. UPPER LEVEL DIVERGENCE ALSO INCREASED ACROSS THE FORECAST AREA LATE LAST EVENING ON NOSE OF 140KT 250MB JET NUDGING IN FROM THE NORTHWEST. EXPECT THIS LARGE SCALE ASCENT TO MOVE EWD OVER NEXT SEVERAL HOURS...ENDING PCPN FROM WEST TO EAST NEAR SUNRISE AS SHORTWAVE ENERGY SHIFTS EAST INTO SRN MN/NRN IA. REGIONAL PROFILERS AND LATEST KOMA ACARS DATA SHOWS AROUND 45KTS AROUND 900MB UP TO 850MB. SFC TROF MOVING THROUGH ERN NEB HAS ALLOWED QUITE A BIT OF MIXING TO OCCUR EARLY THIS MORNING...ESPECIALLY ACROSS EAST CENTRAL NEB WHERE TEMPS HAVE RISEN INTO THE LOWER 50S IN SOME LOCATIONS BY 2AM. COLD AIR ADVECTION IS CURRENTLY UNDERWAY ACROSS NORTHEASTERN NEB WHERE NELIGH PROFILER HAS COME AROUND TO THE NORTHWEST AT 850MB. THIS CAA SHOULD PLAY HAVOC ON HIGH TEMPS TODAY. WE CONTINUE TO UNDERCUT GUIDANCE WITH CAA IN MIND. EVEN SO...FORECAST TEMPS WL STILL BE NEAR OR ABOVE RECORDS AT OMA/57 IN 1998 AND AT LNK/61 IN 1888. GOOD MIXING POTENTIAL AND NEARLY 50KTS AT 850MB WL MAKE FOR BORDERLINE WIND ADVISORY CRITERIA ACROSS NORTHEASTERN NEB AND WEST CENTRAL IOWA FOR A FEW HOURS TODAY. THINK CORE OF STRONG WINDS WILL MIX OUT TO OUR NORTH AND WEST AND THEREFORE HAVE HELD OFF ON ANY ADVISORY...BUT IT MIGHT BE VERY CLOSE FOR A FEW HOURS.

STRONG WARM AIR ADVECTION RESUMES TO OUR WEST OVERNIGHT TONIGHT AND MOVES EWD THRU THE MORNING HOURS AS UPPER RIDGE BUILDS OVER THE HIGH PLAINS AND LOW LEVEL FLOW TURNS SOUTHERLY AHEAD OF LOW PRESSURE MOVING ACROSS SOUTHERN CANADA. BOTH GFS AND NAM ARE FORECASTING +10 TO +12C RESPECTIVELY OVER OMAHA BY 00Z SAT. WITH MORE OF A SOUTHERLY WIND...HAVE DOUBTS WE WILL APPROACH FULL MIXING POTENTIAL. HAVE KNOCKED DOWN HIGHS JUST A LITTLE BUT AM STILL OVERSHOOTING GUIDANCE. COULD BE CLOSE TO RECORDS ONCE AGAIN (64 AT LNK/61 AT OMA/64 AT OFK).

COLD FRONT MOVES OUT OF THE DAKOTAS AND THROUGH THE FORECAST AREA LATE FRIDAY NIGHT/EARLY SATURDAY MORNING AND MUCH COOLER AIR BEHIND THIS FEATURE SETTLES IN FOR THE WEEKEND. INCREASING VERTICAL ASCENT AHEAD OF SHORTWAVE ENERGY MOVING OUT OF COLORADO ALONG WITH MID LEVEL FRONOTOGENETICAL FORCING COULD BE ENOUGH TO SUPPORT PCPN BAND ACROSS WESTERN NEBRASKA LATE SUNDAY NIGHT. EASTERN EXTENT OF BAND WOULD LIKELY BE JUST TO THE WEST OF THE FORECAST AREA AS BOTH 00Z GFS AND NAM INDICATE...BUT THIS WILL CERTAINLY WARRANT WATCHING FOR ANY EWD PROGRESSION IN SUCCESSIVE MODEL RUNS..

UPPER TROF DIGS ACROSS THE WESTERN CONUS EARLY NEXT WEEK WITH A SPLIT FLOW REGIME AND MAIN LOW MOVING TO OUR SOUTH AND ANOTHER WAVE FORMING ACROSS THE NRN PLAINS. 00Z ECMWF AND GFS ARE IN GENERAL AGREEMENT WITH MAIN CLOSED LOW MOVING ACROSS THE SOUTHERN CONUS. HAVE NOT MADE ANY CHANGES TO THE EXTENDED FORECAST AS DAY SHIFT WILL FURTHER EXAMINE.

&&

.OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. &&

$$

GRIFFIS

.DISCUSSION... 09Z SFC ANALYSIS SHOWED A 1010MB LOW PRES CENTER OVER SE CO WITH A LEE TROUGH EXTENDIND SW INTO NM. A 1027MB HIGH PRES CENTER WAS LOCATED OVER SW CO WITH A STATIONARY FRONTAL BOUNDARY TO THE NORTH DRAPED FROM WEST TO EAST ACROSS THE INTERMOUNTAIN WEST. IR SAT IMAGERY SHOWS WIDESPREAD HIGH CLOUDINESS TO THE LEE OF THE ROCKIES WITH MORE EXTENSIVE CLOUD COVER SPREADING EASTWARD INTO THE PAC NW. LATEST 400-200MB AIRCRAFT DATA SHOWS A 100-130 KNOT JET EMBEDDED WITHIN THIS MOIST FLOW OVER THE PAC NW.

21Z SREF AND 18Z MREF CYCLES SHOW VERY GOOD AGREEMENT WITH H5 PATTERN ACROSS INTERMOUNTAIN WEST THROUGH SATURDAY. AFOREMENTIONED FAST ZONAL FLOW INDICATED BY LATEST OBS WILL CONTINUE ACROSS THE REGION THROUGH LATE IN THE WEEK PER MODEL GUIDANCE WITH INTERVALS OF HIGH CLOUDINESS SPREADING OVER NM. THIS FLOW PATTERN WILL ALSO ENHANCE LEE TROUGHING FRIDAY AND SATURDAY ALLOWING WINDS TO BECOME BREEZY ACROSS THE E PLAINS. TEMPS WILL ALSO BE WARMING UP UNDER THIS PATTERN ACROSS THE CWA ESPECIALLY IN THE E PLAINS WITH NEAR RECORD TEMPS IN THE SOUTHEAST FRIDAY AND SATURDAY.

THE UPCOMING WEATHER SYSTEM EMERGING LATE IN THE WEEKEND INTO EARLY NEXT WEEK REMAINS THE MAIN FORECAST CHALLENGE IN THE LONG TERM. 18Z MREF CYCLE SHOWS GOOD AGREEMENT WITH H5 HEIGHT FALLS ACROSS THE SW CONUS SUNDAY AND MONDAY THEN SPREAD INCREASES CONSIDERABLY THROUGH MIDWEEK AS EXPECTED. 00Z GFS MODEL DOES HAVE SUPPORT FROM 00Z ECMWF THAT A SIGNIFICANT CLOSED UPPER LEVEL LOW WILL TRACK ACROSS NM INTO TX WEDNESDAY AND THURSDAY. THIS SOLN WOULD BRING A SIGNIFICANT WINTER STORM ACROSS THE STATE ANYTIME FROM TUESDAY TO THURSDAY. MADE MINOR CHANGES TO FORECAST POPS AND NUDGED TEMPS DOWN WEDNESDAY THROUGH FRIDAY OF NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 48 23 51 25 / 0 0 0 0 GALLUP.......................... 50 15 54 20 / 0 0 0 0 GRANTS.......................... 52 17 56 22 / 0 0 0 0 GLENWOOD........................ 65 26 66 30 / 0 0 0 0 CHAMA........................... 45 9 47 14 / 0 0 0 0 LOS ALAMOS...................... 52 25 55 21 / 0 0 0 0 RED RIVER....................... 44 11 45 15 / 0 0 0 0 TAOS............................ 52 16 54 18 / 0 0 0 0 SANTA FE........................ 50 25 55 26 / 0 0 0 0 SANTA FE AIRPORT................ 51 27 56 28 / 0 0 0 0 ESPANOLA........................ 55 22 60 23 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 57 32 59 32 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 60 25 63 25 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 56 28 58 29 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 59 29 61 30 / 0 0 0 0 SOCORRO......................... 61 27 65 32 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 56 27 58 30 / 0 0 0 0 MORIARTY/ESTANCIA............... 56 24 59 27 / 0 0 0 0 CARRIZOZO....................... 61 28 62 35 / 0 0 0 0 RUIDOSO......................... 57 25 57 27 / 0 0 0 0 RATON........................... 57 21 60 25 / 0 0 0 0 LAS VEGAS....................... 56 28 62 32 / 0 0 0 0 ROY............................. 61 27 64 34 / 0 0 0 0 CLAYTON......................... 61 33 66 37 / 0 0 0 0 SANTA ROSA...................... 64 32 70 37 / 0 0 0 0 TUCUMCARI....................... 63 33 70 37 / 0 0 0 0 FORT SUMNER..................... 66 29 72 34 / 0 0 0 0 CLOVIS.......................... 64 33 71 39 / 0 0 0 0 PORTALES........................ 66 30 72 36 / 0 0 0 0 ROSWELL......................... 69 34 72 39 / 0 0 0 0

&&

.ABQ WATCHES/WARNINGS/ADVISORIES... NONE.

&&

$$

GUYER

.UPDATE...HAVE REMOVED THE SLGT CHC OF MIXED PRECIP FROM NC WI FOR LATE TONIGHT. 00Z RAOBS AND EARLY EVG TAMDAR SOUNDINGS CONTINUED TO SHOW A VERY DRY AIR MASS BLO 700 MB...AND SFC OBS ONLY SHOWED PCPN REACHING THE GROUND NEAR THE CANADIAN BORDER. 00Z NAM-WRF ALSO SHOWED 850 MB CONDENSATION PRESSURE DEFICITS REMAINING AOA 100 MB OVERNIGHT. BAND OF VIRGA/MID-LEVEL CLOUDS (WITH BASES 8-10K FT) OVER NW/WC WI WILL LIFT NE THROUGH GRB CWA OVERNIGHT...BUT GIVEN THE SPARSE MOISTURE...CANNOT SEE ANY PCPN HITTING THE GROUND. ALTHOUGH PCPN CHCS ARE ALSO IN QUESTION FOR TOMORROW...WILL LET THE PREVIOUS FCST RIDE WITH THE EXPECTATION THAT MOISTURE WILL GRADUALLY INCREASE ALONG THE WEAK FRONTAL BOUNDARY AS IT MOVES THROUGH THE FA.

ALSO DROPPED MIN TEMPS A FEW DEGREES...AS SEVERAL LOCATIONS WERE ALREADY APPROACHING FCST MINS. STRONGER RETURN FLOW WILL DEVELOP OVERNIGHT...SO TEMPS SHOULD STEADY OUT OR SLOWLY RISE LATE.

TSK

REST OF DISCUSSION FROM PREVIOUS SHIFT...

.SYNOPSIS...MODEST AMPLIFICATION OF THE LARGE SCALE PATTERN ACRS THE CONUS UNDERWAY. NEW TROF WL DEVELOP OVER THE W WHILE RIDGE BUILDS NEWD TOWARD NEW ENGLAND. THAT WL LEAVE A RELATIVELY FAST WSWLY UPR FLOW ACRS THE AREA BY LATE IN THE WEEKEND. THE TREND BEYOND THAT WL BE FOR THE FLOW TO BECOME INCREASINGLY SPLIT. THE NRN STREAM WL INITIALLY DOMINATE THE AREA...BUT THERE IS A POSSIBILITY OF THE SRN STREAM SHIFTING NWD INTO THE AREA BY LATER NEXT WK.

THE UPR PATTERN WL KEEP COLD AIR BOTTLED UP WELL N OF THE AREA...SO TEMPS WL REMAIN ABV NORMAL. THERE APPEARED TO BE TWO MAIN CHCS OF WIDSPREAD PCPN. THE FIRST WL BE IF MOISTURE FLOW FLOWING NEWD IN SWLY UPR FLOW GETS ACTED UPON BY THE PORTION OF THE WRN TROF THAT SHEARS EWD AS THE SPLIT DEVELOPS. THE SECOND WL BE IF CLOSED UPR SYSTEM IN THE SRN STREAM TRACKS FAR ENOUGH N TO AFFECT THE AREA LATER NEXT WK.

.SHORT TERM...TNGT AND SAT. REMANTS OF ANOTHER STG PAC SYSTEM EXPECTED TO SURGE EWD TNGT AND SAT. SOME SIMILARITIES TO THE SITN WED NGT INTO THU...BUT SYSTEM WL BE WEAKER...HAVE LESS MOISTURE...AND TRACK FARTHER N. HOWEVER GIVEN THAT THE SYSTEM THU MORNING WAS A MUCH BETTER PCPN PRODUCER THAN INITIALLY EXPECTED...WANTED TO CARRY AT LEAST A CHC OF PCPN WITH THE CURRENT SYSTEM. WARM AIR WL SURGE IN QUICKLY ALOFT...AGAIN RAISING THE POSSIBILITY OF FZG PCPN IF THE ONSET IS LATE TNGT OR EARLY SAT. STRUCTURED GRIDS WITH A CHC OF FZG PCPN INTO EARLY SAT. ONE ADDITIONAL DIFFERENCE APPEARS TO BE THE LACK OF STG LOW-LEVEL WLY FLOW. THAT BROUGHT TEMPS TO ARND 50 ACRS THE SRN PART OF THE FCST AREA YDA. GUID ALL COOLER FOR SAT AND SEEMED REASONABLE GIVE THE MORE SLY FLOW EXPECTED.

.LONG TERM...SATURDAY NITE THRU NEXT FRIDAY. FORECAST FOCUS ON PRECIPITATION CHANCES AND TYPE SUNDAY AND SUNDAY NITE.

LOW PRESSURE SYSTEM APPROACHING THE REGION TRENDING CLOSER TO THE REGION WITH THE MODELS SUNDAY AND SUNDAY NITE. THE GFS SOLUTION IS CLOSEST TO THE MREF ENSENBLE MEMBERS WITH PRECIP MOVING IN SUNDAY AFTERNOON ACROSS THE SOUTHERN CWA THEN EXITING THE AREA BY LATE SUNDAY NITE. THE LOW WILL BE FIGHTING SOME DRY AIR IN THE MID LEVELS...WHICH WILL MEAN NOT MUCH MOISTURE AT -10 OR COLDER FOR MUCH OF THE NIGHT. THIS WILL MEAN A MIX OF RAIN...FREEZING RAIN...SLEET AND SNOW WILL FALL ACROSS THE CWA WITH A BETTER CHANCE FOR ICE AND SNOW IN THE NORTHWEST CWA WITH MORE LIQUID TO THE SOUTHEAST. ALTHOUGH THE CANADIAN AND NAM DO NOT DELIVER SUCH A DIRECT HIT...THE CONSENSUS OF THE MREF ENSEMBLES IS ENOUGH OF A REASON TO SIDE WITH THE GFS SOLUTION.

THE REST OF THE WEEK LOOKS DRY AS HIGH PRESSURE BUILDS INTO THE REGION. ALTHOUGH THE CANADIAN AND GFS DEVELOP A LOW PRESSURE SYSTEM THAT GETS CLOSE TO THE SOUTHERN GREAT LAKES WITH SOME QPF IN THE SOUTHERN PORTION OF THE CWA ANYWHERE FROM WEDNESDAY TO THURSDAY...THE MREF KEEPS THE SYSTEM AND ASSOCIATED PRECIP FAR ENOUGH SOUTH TO LEAVE THE CWA DRY FOR NOW. &&

.GRB WATCHES/WARNINGS/ADVISORIES... NONE. &&

$$ WEATHER.GOV/GREENBAY

.DISCUSSION...

THE WARM AIR ADVECTION IS EXPECTED TO INCREASE TODAY OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. PROFILER PLOTS OF WIND AT 850 SHOW A DIFFLUENT AREA OVER NORTHEAST ILLINOIS AT 0800 UTC. THE WIND OVER IOWA AT 850 MB WAS 40 KNOTS OR MORE. THE ACARS SOUNDING AT RFD AT 850 UTC SHOWS THE WIND AROUND 36 KNOTS AT 852 MB. THERE IS AN INVERSION UP TO 1.2 KILOMETERS. THE SURFACE WIND IS STILL FROM THE SOUTHEAST WITH TEMPERATURES IN MIDDLE 30S. PRESSURE FALLS ARE SEEN AT 09 UTC OVER IOWA...ILLINOIS AND WISCONSIN. WILL KEEP THE FORECAST HIGH TEMPERATURES IN THE MIDDLE 50S. THE CLOUDS ARE EXPECTED TO INCREASE WITH APPROACHING COLD FRONT.

THE 200 MB TEMPERATURE ANALYSIS AT 00 UTC SHOWS A TEMPERATURE MAXIMUM OVER NORTHERN MONTANA AND SOUTHERN SASKATCHEWAN. THE 700 MB TROUGH OVER SASKATCHEWAN WILL CONTINUE TO MOVE EAST. HOWEVER THE WARM AIR ADVECTION EAST INTO MANITOBA AND NORTH DAKOTA IS WEAK. THE TROUGH MAY BEGIN TO FILL AS IT MOVES EAST. THE LOW IN SASKATCHEWAN WILL MOVE NORTHEAST AND THE TRAILING FRONT WILL MOVE INTO ILLINOIS SATURDAY NIGHT. USED THE GFS MODEL FOR TIMING AND CALCULATION OF VERTICAL MOTION. MOISTURE TRANSPORT IS INCREASING IN MISSOURI AT 09 UTC. THE NCEP WRF AND LOCALLY RUN WRF SHOW INCREASE MOISTURE TRANSPORT OVER ILLINOIS BY SATURDAY AFTERNOON. WILL KEEP THE CHANCE OF RAIN TONIGHT AND SUNDAY.

THE MODELS SHOW A STATIONARY FRONT SEEN IN THE TEMPERATURE AND DEWPOINT GRADIENTS AND ISENTROPIC ANALYSIS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. THIS MAY PROVIDE ENOUGH FORCING TO INITIATE RAIN SHOWERS ON MONDAY. DID NOT MAKE SIGNIFICANT FORECAST CHANGES FOR THE REST OF THE WEEK.

&&

.AVIATION... 1055 PM CST

FOR THE 06Z TAFS...HIGH PRESSURE WAS CENTERED NEAR CVG WITH RIDGE EXTENDING NWD ACROSS MICHIGAN. HIGH WILL MOVE EAST THROUGH THE OVERNIGHT AS DEEP LOW PRESSURE TRACKS EAST ACROSS THE SRN PRAIRIE PROVINCES OF CANADA. ASSOCIATED COLD FRONT CURRENTLY OVER THE DAKOTAS WILL CROSS MN/WI/IA ON SAT WITH FROPA NOT EXPECTED THRU RFD UNTIL AROUND 06Z SUN...LATER FOR THE CHICAGO AREA TERMINALS. MID/UPR LEVEL CLOUDS ALREADY STREAMING INTO THE LOCAL AREA. STEADILY INCREASING LOW LEVEL MOISTURE AHEAD OF APPROACHING FRONT WILL YIELD PROGRESSIVELY LOWER MVFR CIGS FROM LATE SAT MORNING THROUGH EVENING. SLIGHT POSSIBILITY OF IFR CIGS AND POSSIBLE DZ/-SHRA/BR AFT 03Z COINCIDENT WITH BETTER LIFT DUE TO PASSING FRONTAL WAVE. S/SW WINDS SHOULD GUST TO ABV 20KTS TOMORROW AS 925-850MB SPEEDS INCREASE TO 40KTS AROUND 18Z...DECREASING IN THE EVENING AS FRONT MOVES CLOSER.

RRH

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVISORY FOR ILLINOIS AND INDIANA NEARSHORE THROUGH SATURDAY EVENING. &&

$$

.DISCUSSION... UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE OVER THE UPPER GREAT LAKES WITH A TROUGH ACROSS THE NORTHERN ROCKIES INTO THE CANADIAN PRAIRIES AND TROUGHING ACROSS QUEBEC INTO NEW ENGLAND. THERE IS A CLOSED 500 MB LOW ACROSS CENTRAL SASKATCHEWAN THAT SHOWS UP WELL ON WATER VAPOR WITH STRONG CYCLONIC FLOW AND THERE IS SOME DARKENING PASSING ACROSS MONTANA AND WESTERN MANITOBA.

NAM TAKES THE CLOSED 500 MB LOW TO THE EAST TODAY ALONG WITH THE TROUGH AND THE TROUGH PUSHES EAST AND STAYS MOSTLY TO THE NORTH OF THE CWA. NAM ALSO BRINGS A TROUGH ONTO THE WEST COAST AND SPLITS THE TROUGH INTO THE NORTHERN AND SOUTHERN BRANCHES. THE SOUTHERN BRANCH CLOSED OFF A 500 MB LOW THAT REMAINS IN THE DESERT SW WHILE THE NORTHERN BRANCH HEADS EAST AND AFFECTS THE CWA MON NIGHT AND TUE.

FOR TODAY...NAM SHOWS 850-500 MB Q-VECTOR CONVERGENCE PASSING ACROSS THE CWA WITH 1000-500 MB RH STAYING MOSTLY TO THE NORTH OF THE AREA AND DOES NOT PUT OUT ANY QPF FOR THE CWA. KMPX...KGRB AND KINL 00Z SOUNDINGS ARE VERY DRY IN THE LOW TO MID LEVELS AND THIS DRY AIR WILL HAVE TO BE OVERCOME BEFORE WE CAN SEE ANY PCPN. NAM SHOWING STRONG ISENTROPIC LIFT AND LIMITED MOISTURE IN THE MID LEVELS ON I290-I305K SURFACES...BUT THE LOW LEVELS REMAIN MOSTLY DRY AND THE LIFT AND MOISTURE DEPART TONIGHT. GFS SHOWS ABOUT THE SAME THING...BUT IS A LITTLE MORE GENEROUS WITH ITS QPF AND WITH THE MOISTURE. WILL KEEP LOW CHANCE POPS IN THE FORECAST FOR TODAY AS MOISTURE MOVES ACROSS WITH SOME DYNAMICS. MOISTURE IS LIMITED THOUGH. WILL KEEP SLEET MENTION IN THE FORECAST...BUT IS HARD TO TELL WHAT WILL HAPPEN. EARLIER LOOK AT TAMDAR SOUNDINGS FROM KMPX...KABR...KOAX SHOWED ABOVE FREEZING TEMPERATURES WITH A WARM AND DRY LAYER ALOFT AND THE FURTHER WEST YOU WENT...THE WARMER THE TEMPERATURES. TAMDAR SOUNDINGS FROM KRHI...KCMX...KBJI...KHIB AND KMQT SHOWED TEMPERATURES ALL BELOW ZERO. WILL GO WITH SNOW AND SLEET CHANGING OVER TO RAIN FOR PCPN TYPE FOR TODAY.

FOR TONIGHT...LAKE EFFECT GETS GOING AFTER MIDNIGHT...BUT OVERALL IS NOT GOING TO AMOUNT TO MUCH AS 850 MB TEMPERATURES DROP TO MARGINAL LEVELS AND NAM BUFKIT SOUNDINGS FROM KCMX...KMQT AND KERY SHOW LOW INVERSION HEIGHTS AND WINDS OUT OF THE WEST. ONLY SPOTS TO BE AFFECTED WITH SNOW SHOWERS OR FLURRIES WILL BE WEST FACING SHORELINES OF LAKE SUPERIOR. THERE COULD ALSO BE SOME DRY AIR ADVECTED ACROSS THE LAKE WHICH WILL ALSO MAKE A DENT IN THE COVERAGE AND INTENSITY OF ANY LAKE EFFECT SHOWERS THAT ARE ABLE TO BE CREATED AFTER MIDNIGHT AS TEMPERATURES ARE NOT COLD ENOUGH BEFOREHAND.

NAM BRINGS BACK IN SOME 850-500 MB Q-VECTOR CONVERGENCE SUN NIGHT AND MON MORNING...BUT DEEP MOISTURE IS REALLY NOT THERE. MORE 850-500 MB Q-VECTOR CONVERGENCE RETURNS MON NIGHT...BUT AGAIN DEEP MOISTURE REALLY IS NOT THERE. WILL CONTINUE WITH THE LOW CHANCE POPS WITH BETTER LAKE EFFECT CONDITIONS ARRIVING SUNDAY NIGHT WITH THE SHORTWAVE AND MUCH COLDER AIR COMING DOWN ACROSS LAKE SUPERIOR. THE SHORTWAVE SHOULD HELP RAISE INVERSION HEIGHTS AND THE COLDER TEMPERATURES DOWN TO -8C TO -10C WILL BE ENOUGH FOR LAKE EFFECT TO KICK UP. INVERSION HEIGHTS THOUGH STAY BELOW 5000 FEET ACCORDING TO GFS BUFKIT SOUNDINGS...SO THINGS SHOULD NOT GET TOO OUT OF HAND FOR THE LAKE EFFECT SNOW.

OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES EXCEPT LOWERED HIGHS SLIGHTLY AND WENT CLOSER TO ADJENS AND ADJMEL FOR LOWS.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...NONE. &&

$$

MICHELS

.MORNING UPDATE... 915 AM CST

LOW CLOUDS CONTINUE TO RAPIDLY SPREAD NORTHWARD ACROSS THE FORECAST AREA THIS MORNING WITH WARM/MOIST ADVECTION WELL UNDERWAY. BLUE RIVER PROFILER INDICATING 850 HPA WINDS ON THE ORDER OF 40 KNOTS THIS MORNING OUT OF THE S-SW. ONLY TWEAK TO FORECAST THIS MORNING WAS TO JUST SHAVE A FEW DEGREES OFF AFTERNOON HIGHS GIVEN PRESENCE OF LOW CLOUDS. STILL SHOULD SEE HIGHS REACH AROUND 50 ACROSS THE FAR NORTH BY LATE THIS AFTERNOON GIVEN THE STRENGTH OF THERMAL/MOISTURE ADVECTION HOWEVER. OTHERWISE...NO CHANGES TO FORECAST. NDM

&&

.PREV DISCUSSION FOR MORNING ZONES/GRIDS... 320 AM CST

THE WARM AIR ADVECTION IS EXPECTED TO INCREASE TODAY OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. PROFILER PLOTS OF WIND AT 850 SHOW A DIFFLUENT AREA OVER NORTHEAST ILLINOIS AT 0800 UTC. THE WIND OVER IOWA AT 850 MB WAS 40 KNOTS OR MORE. THE ACARS SOUNDING AT RFD AT 850 UTC SHOWS THE WIND AROUND 36 KNOTS AT 852 MB. THERE IS AN INVERSION UP TO 1.2 KILOMETERS. THE SURFACE WIND IS STILL FROM THE SOUTHEAST WITH TEMPERATURES IN MIDDLE 30S. PRESSURE FALLS ARE SEEN AT 09 UTC OVER IOWA...ILLINOIS AND WISCONSIN. WILL KEEP THE FORECAST HIGH TEMPERATURES IN THE MIDDLE 50S. THE CLOUDS ARE EXPECTED TO INCREASE WITH APPROACHING COLD FRONT.

THE 200 MB TEMPERATURE ANALYSIS AT 00 UTC SHOWS A TEMPERATURE MAXIMUM OVER NORTHERN MONTANA AND SOUTHERN SASKATCHEWAN. THE 700 MB TROUGH OVER SASKATCHEWAN WILL CONTINUE TO MOVE EAST. HOWEVER THE WARM AIR ADVECTION EAST INTO MANITOBA AND NORTH DAKOTA IS WEAK. THE TROUGH MAY BEGIN TO FILL AS IT MOVES EAST. THE LOW IN SASKATCHEWAN WILL MOVE NORTHEAST AND THE TRAILING FRONT WILL MOVE INTO ILLINOIS SATURDAY NIGHT. USED THE GFS MODEL FOR TIMING AND CALCULATION OF VERTICAL MOTION. MOISTURE TRANSPORT IS INCREASING IN MISSOURI AT 09 UTC. THE NCEP WRF AND LOCALLY RUN WRF SHOW INCREASE MOISTURE TRANSPORT OVER ILLINOIS BY SATURDAY AFTERNOON. WILL KEEP THE CHANCE OF RAIN TONIGHT AND SUNDAY.

THE MODELS SHOW A STATIONARY FRONT SEEN IN THE TEMPERATURE AND DEWPOINT GRADIENTS AND ISENTROPIC ANALYSIS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. THIS MAY PROVIDE ENOUGH FORCING TO INITIATE RAIN SHOWERS ON MONDAY. DID NOT MAKE SIGNIFICANT FORECAST CHANGES FOR THE REST OF THE WEEK.

&&

.AVIATION... 550 AM CST

RE 12Z TAFORS...SURFACE RIDGE HAS CONTINUED TO MOVE EASTWARD ACROSS THE GREAT LAKES AND OH VALLEY DURING THE OVERNIGHT...WITH A STRONG RETURN FLOW OFF THE WESTERN GULF VERY EVIDENT AS DEW POINTS WELL INTO THE 50S SURGE NORTHWARD ACROSS THE OZARKS. THIS TO CONTINUE TODAY WITH THE MOIST LOW LEVEL AIR ARRIVING IN THE LOCAL AREA AROUND MIDDAY. AS IT DOES EXPECT RAPID SPREAD SOUTH TO NORTH OF MVFR CEILINGS ACROSS THE TERMINALS. WHILE VERY MOIST IN LOW LEVELS WITH GULF MOISTURE AS WELL AS IN HIGH LEVELS WITH PACIFIC MOISTURE...MID LEVELS REMAIN QUITE DRY WITH WEST TO TO WEST-SOUTHWEST FLOW. HOWEVER...ISENTROPIC UPGLIDE IN THE VERY MOIST LOWER LEVEL AIR AS WELL AS CONVERGENCE AHEAD OF THE FRONTAL BOUNDARY TO BE APPROACHING FROM THE WEST LATE THIS AFTERNOON WILL BE ENOUGH TO GENERATE DRIZZLE AND LIGHT RAIN THIS EVENING...WITH CLOUD BASES LOWERING BELOW 1K FT. AS THE UPPER LOW OVER SOUTHERN SASKATCHEWAN MOVES INTO WESTERN ONTARIO THIS EVENING THE FRONT WILL SETTLE INTO THE CENTRAL GREAT LAKES BEFORE BECOMING STATIONARY ACROSS CENTRAL IL AND NORTHERN IN AS THE BOUNDARY BECOMES PARALLEL WITH THE MID AND UPPER FLOW. MODELS SHOW SUFFICIENT SUBSIDENCE IN THE LOW LEVELS TO IMPROVE CONDITIONS TO VFR DURING THE LATE NIGHT. MOMENTUM OF STRONG WINDS CURRENTLY ABOVE THE LOW LEVEL INVERSION WILL START TO TRANSFER DOWNWARD ONCE THE WARM FRONT CURRENTLY MOVING ACROSS THE MS RIVER FROM MO INTO IL LIFTS THROUGH THE AREA. BUT WITH LOW LEVEL INVERSION STILL IN PLACE THROUGH THE DAY THIS TRANSFER TO BE SIGNIFICANTLY TEMPERED.

TRS

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVISORY FOR ILLINOIS AND INDIANA NEARSHORE THROUGH SATURDAY EVENING. &&

$$

.DISCUSSION... 320 AM CST

THE WARM AIR ADVECTION IS EXPECTED TO INCREASE TODAY OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. PROFILER PLOTS OF WIND AT 850 SHOW A DIFFLUENT AREA OVER NORTHEAST ILLINOIS AT 0800 UTC. THE WIND OVER IOWA AT 850 MB WAS 40 KNOTS OR MORE. THE ACARS SOUNDING AT RFD AT 850 UTC SHOWS THE WIND AROUND 36 KNOTS AT 852 MB. THERE IS AN INVERSION UP TO 1.2 KILOMETERS. THE SURFACE WIND IS STILL FROM THE SOUTHEAST WITH TEMPERATURES IN MIDDLE 30S. PRESSURE FALLS ARE SEEN AT 09 UTC OVER IOWA...ILLINOIS AND WISCONSIN. WILL KEEP THE FORECAST HIGH TEMPERATURES IN THE MIDDLE 50S. THE CLOUDS ARE EXPECTED TO INCREASE WITH APPROACHING COLD FRONT.

THE 200 MB TEMPERATURE ANALYSIS AT 00 UTC SHOWS A TEMPERATURE MAXIMUM OVER NORTHERN MONTANA AND SOUTHERN SASKATCHEWAN. THE 700 MB TROUGH OVER SASKATCHEWAN WILL CONTINUE TO MOVE EAST. HOWEVER THE WARM AIR ADVECTION EAST INTO MANITOBA AND NORTH DAKOTA IS WEAK. THE TROUGH MAY BEGIN TO FILL AS IT MOVES EAST. THE LOW IN SASKATCHEWAN WILL MOVE NORTHEAST AND THE TRAILING FRONT WILL MOVE INTO ILLINOIS SATURDAY NIGHT. USED THE GFS MODEL FOR TIMING AND CALCULATION OF VERTICAL MOTION. MOISTURE TRANSPORT IS INCREASING IN MISSOURI AT 09 UTC. THE NCEP WRF AND LOCALLY RUN WRF SHOW INCREASE MOISTURE TRANSPORT OVER ILLINOIS BY SATURDAY AFTERNOON. WILL KEEP THE CHANCE OF RAIN TONIGHT AND SUNDAY.

THE MODELS SHOW A STATIONARY FRONT SEEN IN THE TEMPERATURE AND DEWPOINT GRADIENTS AND ISENTROPIC ANALYSIS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. THIS MAY PROVIDE ENOUGH FORCING TO INITIATE RAIN SHOWERS ON MONDAY. DID NOT MAKE SIGNIFICANT FORECAST CHANGES FOR THE REST OF THE WEEK.

&&

.AVIATION... 550 AM CST

RE 12Z TAFORS...SURFACE RIDGE HAS CONTINUED TO MOVE EASTWARD ACROSS THE GREAT LAKES AND OH VALLEY DURING THE OVERNIGHT...WITH A STRONG RETURN FLOW OFF THE WESTERN GULF VERY EVIDENT AS DEW POINTS WELL INTO THE 50S SURGE NORTHWARD ACROSS THE OZARKS. THIS TO CONTINUE TODAY WITH THE MOIST LOW LEVEL AIR ARRIVING IN THE LOCAL AREA AROUND MIDDAY. AS IT DOES EXPECT RAPID SPREAD SOUTH TO NORTH OF MVFR CEILINGS ACROSS THE TERMINALS. WHILE VERY MOIST IN LOW LEVELS WITH GULF MOISTURE AS WELL AS IN HIGH LEVELS WITH PACIFIC MOISTURE...MID LEVELS REMAIN QUITE DRY WITH WEST TO TO WEST-SOUTHWEST FLOW. HOWEVER...ISENTROPIC UPGLIDE IN THE VERY MOIST LOWER LEVEL AIR AS WELL AS CONVERGENCE AHEAD OF THE FRONTAL BOUNDARY TO BE APPROACHING FROM THE WEST LATE THIS AFTERNOON WILL BE ENOUGH TO GENERATE DRIZZLE AND LIGHT RAIN THIS EVENING...WITH CLOUD BASES LOWERING BELOW 1K FT. AS THE UPPER LOW OVER SOUTHERN SASKATCHEWAN MOVES INTO WESTERN ONTARIO THIS EVENING THE FRONT WILL SETTLE INTO THE CENTRAL GREAT LAKES BEFORE BECOMING STATIONARY ACROSS CENTRAL IL AND NORTHERN IN AS THE BOUNDARY BECOMES PARALLEL WITH THE MID AND UPPER FLOW. MODELS SHOW SUFFICIENT SUBSIDENCE IN THE LOW LEVELS TO IMPROVE CONDITIONS TO VFR DURING THE LATE NIGHT. MOMENTUM OF STRONG WINDS CURRENTLY ABOVE THE LOW LEVEL INVERSION WILL START TO TRANSFER DOWNWARD ONCE THE WARM FRONT CURRENTLY MOVING ACROSS THE MS RIVER FROM MO INTO IL LIFTS THROUGH THE AREA. BUT WITH LOW LEVEL INVERSION STILL IN PLACE THROUGH THE DAY THIS TRANSFER TO BE SIGNIFICANTLY TEMPERED.

TRS

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVISORY FOR ILLINOIS AND INDIANA NEARSHORE THROUGH SATURDAY EVENING. &&

$$

.MORNING UPDATE... 915 AM CST

LOW CLOUDS CONTINUE TO RAPIDLY SPREAD NORTHWARD ACROSS THE FORECAST AREA THIS MORNING WITH WARM/MOIST ADVECTION WELL UNDERWAY. BLUE RIVER PROFILER INDICATING 850 HPA WINDS ON THE ORDER OF 40 KNOTS THIS MORNING OUT OF THE S-SW. ONLY TWEAK TO FORECAST THIS MORNING WAS TO JUST SHAVE A FEW DEGREES OFF AFTERNOON HIGHS GIVEN PRESENCE OF LOW CLOUDS. STILL SHOULD SEE HIGHS REACH AROUND 50 ACROSS THE FAR NORTH BY LATE THIS AFTERNOON GIVEN THE STRENGTH OF THERMAL/MOISTURE ADVECTION HOWEVER. OTHERWISE...NO CHANGES TO FORECAST. NDM

&&

.PREV DISCUSSION FOR MORNING ZONES/GRIDS... 320 AM CST

THE WARM AIR ADVECTION IS EXPECTED TO INCREASE TODAY OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. PROFILER PLOTS OF WIND AT 850 SHOW A DIFFLUENT AREA OVER NORTHEAST ILLINOIS AT 0800 UTC. THE WIND OVER IOWA AT 850 MB WAS 40 KNOTS OR MORE. THE ACARS SOUNDING AT RFD AT 850 UTC SHOWS THE WIND AROUND 36 KNOTS AT 852 MB. THERE IS AN INVERSION UP TO 1.2 KILOMETERS. THE SURFACE WIND IS STILL FROM THE SOUTHEAST WITH TEMPERATURES IN MIDDLE 30S. PRESSURE FALLS ARE SEEN AT 09 UTC OVER IOWA...ILLINOIS AND WISCONSIN. WILL KEEP THE FORECAST HIGH TEMPERATURES IN THE MIDDLE 50S. THE CLOUDS ARE EXPECTED TO INCREASE WITH APPROACHING COLD FRONT.

THE 200 MB TEMPERATURE ANALYSIS AT 00 UTC SHOWS A TEMPERATURE MAXIMUM OVER NORTHERN MONTANA AND SOUTHERN SASKATCHEWAN. THE 700 MB TROUGH OVER SASKATCHEWAN WILL CONTINUE TO MOVE EAST. HOWEVER THE WARM AIR ADVECTION EAST INTO MANITOBA AND NORTH DAKOTA IS WEAK. THE TROUGH MAY BEGIN TO FILL AS IT MOVES EAST. THE LOW IN SASKATCHEWAN WILL MOVE NORTHEAST AND THE TRAILING FRONT WILL MOVE INTO ILLINOIS SATURDAY NIGHT. USED THE GFS MODEL FOR TIMING AND CALCULATION OF VERTICAL MOTION. MOISTURE TRANSPORT IS INCREASING IN MISSOURI AT 09 UTC. THE NCEP WRF AND LOCALLY RUN WRF SHOW INCREASE MOISTURE TRANSPORT OVER ILLINOIS BY SATURDAY AFTERNOON. WILL KEEP THE CHANCE OF RAIN TONIGHT AND SUNDAY.

THE MODELS SHOW A STATIONARY FRONT SEEN IN THE TEMPERATURE AND DEWPOINT GRADIENTS AND ISENTROPIC ANALYSIS OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. THIS MAY PROVIDE ENOUGH FORCING TO INITIATE RAIN SHOWERS ON MONDAY. DID NOT MAKE SIGNIFICANT FORECAST CHANGES FOR THE REST OF THE WEEK.

&&

.AVIATION...

18Z TAFS...SEVERAL CONCERNS THIS PERIOD BUT OVERALL FEW CHANGES TO GOING TAFS. LOW MVFR DECK RACED NORTH ACROSS THE AREA THIS MORNING ON STRONG LOW LEVEL WINDS. A FEW BREAKS SEEN IN VIS IMAGERY BUT OVERALL NOT EXPECTING THESE BREAKS TO LAST FOR ANY EXTENDED PERIOD OF TIME. THUS WILL CONTINUE WITH CURRENT BKN LOW MVFR OVC 2KFT DECK TO INDICATE SOME HOLES FROM TIME TO TIME...THOUGH THEY APPEAR TO BE FILLING RAPIDLY FROM THE NW. STRONGEST GRADIENT OVER THE AREA CURRENTLY WITH SOUTHERLY WINDS 15KTS WITH GUSTS TO 20KTS... SLOWLY DIMINISHING THRU THE AFTERNOON.

WARM MOIST AIR CONTINUES TO SURGE NORTH AHEAD OF AN APPROACHING COLD FRONT TONIGHT. EXPECT CIGS TO QUICKLY DROP INTO IFR AFTER SUNSET THEN POSSIBLY INTO LIFR WITH DRIZZLE...PERHAPS A FEW SHOWERS INTO EARLY SUNDAY MORNING. MODELS RATHER CONSISTENT PUSHING COLD FRONT SOUTH OF ALL THE TERMINALS BY 12Z SUNDAY. WINDS WILL TURN NW THEN NORTH BEHIND FRONT AND WITH DRIER AND COOLER AIR ADVECTING IN... CIGS SHOULD LIFT THRU MVFR AND LIKELY BECOME VFR AFTER SUNRISE SUNDAY.

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVISORY FOR ILLINOIS AND INDIANA NEARSHORE THROUGH SATURDAY EVENING. &&

$$

.SHORT TERM... TONIGHT AND SUNDAY...MILD AND MOIST AIR WAS SPREADING RAPIDLY NORTH INTO ILLINOIS AND FAR SW INDIANA THIS AFTERNOON. ACARS SOUNDINGS OVER IL INDICATED THE TOP OF THE MOISTURE WAS AROUND 850 MB...BUT DEW POINTS AROUND 925 MB WERE BETWEEN 11C AND 12C. AN AREA OF LOW CLOUDS COVERED MUCH OF IL AT 1930Z WITH PATCHY FOG. NAM/WRF INITIALIZED THE LOWER LEVELS BETTER THAN THE GFS OR NGM...SO FAVOR THE NAM/WRF IN THIS REGARD. THIS AREA OF MOISTURE AND LOW CLOUDS SHOULD TRANSLATE EAST TONIGHT. HAVE INTRODUCED DRIZZLE AND AREAS OF FOG TONIGHT AS MOISTURE SPREADS NORTH AND NORTHEAST...AND AS A COLD FRONT MOVES SOUTHEAST. GIVEN THE CLOUD COVER AND MILD SOUTH FLOW...LOWS SHOULD BE VERY MILD FOR THIS TIME OF YEAR. HAVE CUT BACK TEMPS SUNDAY CONSIDERING CLOUDS AND THE POSSIBILITY OF SOME FOG AND LIGHT PRECIPITATION.

&&

.LONG TERM...

SUNDAY NIGHT THROUGH SATURDAY...

THE MEDIUM RANGE MODELS CONTINUE TO WAVER ALL OVER THE CENTRAL CONUS WITH TRACK OF CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW FOR WED THROUGH FRIDAY TIME FRAME. THE SPREAD IN SOLUTIONS HAVE RANGED FROM WISCONSIN TO TENNESSEE AND NOW BACK TO WISCONSIN. NO CONFIDENCE IN ANY SOLUTION AT THIS POINT SO HAVE CHOSEN TO NOT CHANGE THE GRIDS AND FOLLOW PERSISTENCE UNTIL WE SEE MORE THAN ONE OR TWO MODEL RUNS THAT ARE CONSISTENT. THE MODELS ARE HAVING THEIR USUAL PROBLEMS HANDLING THE SPLIT FLOW PATTERN WITH A CLOSED LOW IN THE SOUTHWEST CONUS. MORE CONSISTENT SOLUTIONS WILL NOT APPEAR UNTIL THE STRONG ENERGY IN THE PACIFIC IS CAPTURED BY THE UPPER AIR NETWORK AND MODELS FIGURE OUT HOW THIS ENERGY WILL INTERACT WITH THE UPPER LOW IN THE SOUTHWEST.

IN THE EARLY PERIODS OF THE LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...STILL LOOKS LIKE COLD FRONT WILL BE ACROSS OUR AREA SUNDAY NIGHT AS WEAK LOW PRESSURE MOVES ALONG FRONT. TIGHTENING BAROCLINIC ZONE AND FRONTOGENESIS WITH THIS WAVE SHOULD YIELD SOME PRECIPITATION...MAINLY NORTH OF FRONTAL BOUNDARY. TIME HIGHT CROSS SECTIONS AND LAYER RH ANALYSIS SHOWS BULK OF MOISTURE CONFINED TO LOWER LEVELS...MAINLY BELOW 700MB AND GULF IS CUT OFF. WATER VAPOR DOES SHOW A PACIFIC PLUME TODAY COMING INTO SOUTHWEST CONUS. THIS PLUME SHOULD BE ABLE TO FEED SOME MOISTURE INTO THE WEAK SYSTEM. WILL KEEP THE HIGH CHANCE POPS GOING GIVEN MARGINAL MOISTURE AND EXPECTED LIGHT PRECIPITATION EVENT. SHOULD SEE A WIDE RANGE OF TEMPERATURES SUNDAY NIGHT AND EARLY MONDAY ACROSS THE BOUNDARY UNTIL IT FINALLY PASSES THROUGH FORECAST AREA AND COLDER AIR SPILLS IN. POST FRONTAL AIRMASS IS NOT ARCTIC BUT SHOULD BRING TEMPS BACK CLOSER TO NORMAL. AS MENTIONED ABOVE...FORECAST HAS MUCH UNCERTAINTY TO IT BEYOND WEDNESDAY SO FEW CHANGES MADE AT THIS TIME.

&&

.AVIATION...

18Z VFR CONDITIONS OVER CWA BUT EXPECT MVFR DECK OVER IL TO PUSH EAST THIS AFTERNOON...ADDED MVFR CLOUD DECK TO BOTH SBN AND FWA. GIVEN CURRENT PRESSURE GRADIENT OVER IL/IN/OH AND SEVERAL OBS IN THE REGION WITH GUSTS...DECIDED TO PUT GUSTS IN TAFS FOR THIS AFTERNOON. WITH LOW LEVEL MOISTURE ON THE INCREASE THROUGH TOMORROW AS FRONT APPROACHES FROM THE NORTH...BELIEVE CIGS WILL GRADUALLY DECREASE TONIGHT. ALSO...SURFACE MOISTURE AND DECREASING WINDS FAVORABLE FOR FOG FORMATION BEGINNING AROUND 4Z TO 8Z. LEFT VSBYS AND CIGS AT MVFR FOR NOW...BUT MAY NEED TO BE DROPPED TO IFR IN LATER TAF ISSUANCES.

&&

.IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE.

&&

$$

SHORT TERM...SKIPPER AVIATION...LAMMERS/SKIPPER LONG TERM...LASHLEY

.DAYS 1-2...

MAIN FORECAST PROBLEMS WILL BE IF WE GET ANY DZ/FZDZ TONIGHT, ALONG WITH TEMPERATURES.

12Z ANALYSIS HAS SOUTHWESTERLY FLOW ALOFT OVER THE PLAINS, WITH THE WV LOOP SHOWING A NORTHERN BRANCH SHORTWAVE MOVING ACROSS SOUTH CENTRAL CANADA. THIS SHORTWAVE HAS HELPED PUSH A FRONTAL BOUNDARY THROUGH WESTERN KANSAS THIS MORNING, AND IT SHOULD STALL OUT SOMEWHERE OVER CENTRAL OK TONIGHT. MID LEVELS ARE WARM AND DRY THIS MORNING, BUT SOME SHALLOW SFC MOISTURE HAD BEGUN TO WORK ITS WAY INTO EASTERN KS. THE SLOWLY ADVANCING FRONT HAS PUSHED THIS LOW LEVEL MOISTURE FURTHER EAST, WITH DRIER AIR ADVECTING IN BEHIND IT OVER OUR AREA. SFC WINDS WILL BECOME MORE NORTHEASTERLY LATER TONIGHT AS THE SFC TROUGH MOVES EAST. EVEN WITH UPSLOPE HOWEVER, CONDITIONS ARE NOT QUITE AS SATURATED AS THEY COULD BE. NAM MODEL SOUNDINGS SHOW SOME STRATUS POSSIBILITIES, BUT THE MOISTURE DOES NOT MAKE IT ALL THE WAY DOWN TO THE SFC. THE RUC ALSO SHOWED A MARKED DECREASE IN SFC RH BETWEEN ITS 12Z AND 15Z RUNS. THINK THAT THE BEST CHANCES OF SEEING ANY DZ WILL BE OVER SOUTHEASTERN KS WHERE THE MOISTURE WILL BE BETTER AND IT WILL BE CLOSER TO THE FRONTAL BOUNDARY. PULLED OUR WX OVER THE NORTHERN COUNTIES FOR TONIGHT, AS IT LOOKS LIKE IT WILL BE TOO DRY, ALTHOUGH SOME DZ IS NOT COMPLETELY OUT OF THE QUESTION IN OUR FAR SOUTHEAST.

CLOUD COVER TONIGHT WILL KEEP TEMPS FROM FALLING OFF TOO MUCH, DESPITE THE INCOMING DRIER AIR. KEPT LOWS IN THE UPPER 20S TO MID 30S. THE CLOUDS SHOULD CONTINUE THROUGH MUCH OF THE DAY TOMORROW, AND WITH 850MB TEMPS QUITE A BIT COOLER, HIGHS SHOULD BE A BIT MORE SEASONABLE. TRIMMED READINGS IN THE SOUTHEAST A BIT WITH CLOUDS HANGING AROUND, BUT HIGHS IN THE 40S ACROSS THE REST OF THE CWA CONTINUE TO LOOK GOOD. A WEAK JET STREAK COMING OUT WILL HELP BRING A REINFORCING SHOT OF COLD AIR SUNDAY NIGHT AND INTO MONDAY. 850MB TEMPS DROP DOWN INTO THE -3 TO -1 C RANGE, AND HIGHS SHOULD STAY IN THE UPPER 30S TO LOW 40S.

.DAYS 3-7...

LOTS OF UNCERTAINTIES EXIST IN THE DETAILS AS THE VIGOROUS UPPER LEVEL TROUGH NEAR 125W THIS AFTERNOON DIGS INTO THE SOUTHWESTERN PART OF THE COUNTRY AND SUBSEQUENTLY LIFTS NORTHEASTWARD OVER THE CENTRAL PLAINS. THE GFS, CANADIAN AND ECMWF ARE IN REASONABLY GOOD AGREEMENT IN THE TRAJECTORY OF THE UPPER LEVEL CYCLONE, ALTHOUGH THERE ARE DIFFERENCES IN RELATIVELY MINOR DETAILS...LIKE THE TEMPERATURE STRUCTURE OF THE LOWER LEVELS OF THE ATMOSPHERE...THAT CAN HAVE A DRAMATIC EFFECT ON PRECIPITATION TYPE. UNFORTUNATELY... EVEN THREE TO FOUR DAYS OUT...CONFIDENCE IN THESE DETAILS IS NOT HIGH. THE GFS LARGELY WAS USED FOR GRID MANIPULATION.

A TROPICAL CONVECTIVE FLARE-UP WHICH WAS EVIDENT ON SATELLITE IMAGERY BETWEEN 150W AND 170W EARLY THIS AFTERNOON APPEARS TO BE PROPAGATING RAPIDLY EASTWARD ALONG THE ITCZ. TWIN ANTICYCLONES WERE EVIDENT IN HIGH LEVEL WIND ANOMALIES IN THE NORTHERN AND SOUTHERN HEMISPHERE IN THE VICINITY OF THIS AREA OF ENHANCED THUNDERSTORM ACTIVITY. OUTFLOW FROM THE THUNDERSTORM CLUSTER WAS QUITE EVIDENT ON SATELLITE IMAGERY JUST SOUTH OF 30N. THE ANTICYCLONE NORTH OF THE CONVECTIVE CLUSTER WAS ENHANCING JET LEVEL FLOW NEAR 30N, AND THE ANOMALOUSLY STRONG JET SHOULD SERVE TO KEEP THE WAVE NEAR 125W PROGRESSIVE AS IT MOVES ACROSS THE UNITED STATES. THE 06Z GFS UNDERESTIMATED THE STRENGTH OF THE JET NEAR 30N, BASED ON SATELLITE AND AIRCRAFT WINDS OVER THE PACIFIC. THE GFS ALSO UNDERESTIMATED THE STRENGTH OF THE JET STREAK NEAR 150W...WHICH WOULD SUGGEST THAT THE UPPER LEVEL TROUGH THAT RIPPLES ACROSS SOUTHERN CANADA AND DROPS INTO THE NORTHERN PLAINS MONDAY MAY BE EVEN STRONGER THAN DEPICTED BY THE GFS.

THE VIGOROUS UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS MONDAY WILL SUPPORT A SOUTHWARD SURGE OF COLD AIR ACROSS THE CENTRAL PART OF THE COUNTRY MONDAY. BY MONDAY NIGHT, THE UPPER LEVEL WAVE WILL HAVE CLOSED OFF OVER SOUTHERN CALIFORNIA, AND LOW LEVEL MOISTURE WILL BEGIN TO LIFT NORTHWARD OVER THE BAROCLINIC ZONE OVER NORTHERN OKLAHOMA AND SOUTHERN KANSAS. CONFIDENCE IS NOT GREAT ON EXACTLY WHEN PRECIPITATION WILL BEGIN TO FALL ALONG THE OKLAHOMA BORDER, BUT SOME TYPE OF PRECIPITATION LIKELY WILL START BEFORE SUNRISE TUESDAY. MODEL SOUNDINGS AND CONSTANT LEVEL CHARTS SUGGEST THAT A WARM TONGUE WILL SPREAD BACK NORTHWARD AS THE ISENTROPIC LIFTING BEGINS, WHILE THE BOUNDARY LAYER REMAINS COLD FROM RADIATIONAL COOLING BEFORE THE ONSET OF ISENTROPIC LIFTING. AS SUCH, THE POTENTIAL EXISTS FOR THE PRECIPITATION TO BEGIN AS LIGHT FREEZING RAIN BEFORE CHANGING TO RAIN AS TEMPERATURES GRADUALLY WARM TUESDAY. THE PRECIPITATION PROBABLY WILL BEGIN AS LIGHT SNOW IN DEEPER COLD AIR IN FAR WESTERN KANSAS AND REMAIN FROZEN FOR MUCH OF THE DAY TUESDAY. THE SNOW WILL BE VERY WET, AND WITH SURFACE TEMPERATURES RISING TO NEAR OR SLIGHTLY ABOVE FREEZING, THERE SHOULD NOT BE GREAT ACCUMULATIONS OF SNOW ON THE GROUND.

AS THE UPPER LEVEL CYCLONE APPROACHES TUESDAY NIGHT, A VERY STRONG LOW LEVEL JET WILL TRANSPORT LARGE QUANTITIES OF MOISTURE OVER SOUTHWEST KANSAS. THIS WILL RESULT IN A FAIRLY HEAVY RAIN EVENT FOR THIS TIME OF THE YEAR TUESDAY NIGHT INTO WEDNESDAY MORNING. MODEL SOUNDINGS ALSO SUGGEST SOME ELEVATED INSTABILITY, AND A FEW EMBEDDED THUNDERSTORMS ARE A DEFINITE POSSIBILITY FROM DODGE CITY EAST. AS THE UPPER LEVEL CYCLONE LIFTS OUT OVER WESTERN KANSAS WEDNESDAY, A DRY INTRUSION WILL SHUT OFF PRECIPITATION ACROSS MUCH OF SOUTHWEST KANSAS BY EARLY WEDNESDAY AFTERNOON. SOME WRAP AROUND SNOW WILL CONTINUE NEAR THE COLORADO BORDER AND LIKELY WILL PERSIST THROUGH EARLY THURSDAY ALONG I70.

AFTER THE UPPER LEVEL CYCLONE MOVES EAST OF THIS PART OF THE COUNTRY, BENIGN WEATHER WILL RETURN FOR SEVERAL DAYS WITH TEMPERATURES NEAR SEASONAL AVERAGES. LITTLE CHANGE WAS MADE IN HPC GUIDANCE FOR THE LATER PERIODS.

&&

.PRELIMINARY POINT TEMPS/POPS... DDC 31 45 24 40 / 0 0 0 0 GCK 29 42 21 37 / 0 0 0 0 EHA 28 48 21 39 / 0 0 0 0 LBL 31 47 24 40 / 0 0 0 0 HYS 31 40 24 39 / 0 0 0 0 P28 36 52 31 43 / 0 0 0 0

&&

.DDC WATCHES/WARNINGS/ADVISORIES... NONE. &&

$$

FN26/01

.DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WSW FLOW ALF OVER THE UPR GRT LKS BTWN FAIRLY POTENT SHRTWV MOVING ACRS SCNTRL CAN AND RDG OVER THE GLFMEX. FA CURRENTLY DOMINATED BY WAD IN ADVANCE OF PACIFIC TYPE COLD FNT ATTENDANT TO SFC LO PRES OVER LK WINNIPEG THIS FNT IS MOVING INTO WRN MN THIS AFTN...BUT DRY SLOTTING PUNCHING OVER THIS BNDRY PER 12Z MPX SDNG AND 17Z TAMDAR SDNG FM BJI UNDER WSW H3-7 JET AXIS HAS PREVENTED MUCH IF ANY PCPN FM FRMG AHEAD OF THIS BNDRY. HOWEVER...COMBINATION OF HIER LVL MSTR AND LLVL MSTR BLO WAD INVRN SHOWN ARND H9 HAS KEPT SKIES CLDY OVER THE FA. AIRMASS BEHIND THE BNDRY IS QUITE DRY AND NOT PARTICULARY COLD PER 12Z BIS SDNG (H85 TEMP -1C WITH DWPT DEPRESSION 22C). AIRMASS FARTHER W AT GGW IS A BIT COLDER (H85 TEMP -5C) AND MOISTER (DWPT DEPRESSION ONLY 1C).

MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD/TEMP TRENDS AND LES CHCS.

FOR TNGT...SHRTWV/ASSOCIATED SFC LO OVER SCNTRL CAN PROGGED TO MOVE TO NEAR JAMES BAY BY 12Z SUN...DRAGGING PACIFIC TYPE COLD FNT ACRS THE FA THIS EVNG. EXPECT JUST A BIT OF -DZ OVER THE E THIS EVNG WITH MOISTURE ADDED OFF LK MI IN SLY FLOW AHEAD OF THIS BNDRY RIDING UNDER INFLUX OF MID LVL DRY AIR. NAM IS MUCH MORE AGGRESSIVE AT COOLING/MOISTENING THE LLVLS IN THE STRONG WLY FLOW BEHIND THE FNT TNGT THAN GFS. PER BIS SDNG...WL TREND TOWARD THE WARMER/DRIER GFS FCST. GFS FCST SDNG FM CMX AT 12Z SUN INDICATES INVRN BASE TEMP JUST BLO H85 AT ONLY -8C...MARGINALLY COLD FOR LES AND NOT PARTICULARLY FVRBL FOR ICE NUCLEATION. RATHER DRY INVRN BASE LYR IN GOOD AGREEMENT WITH AIRMASS AT BIS THIS MRNG WOULD ALSO TEND TO MINIMIZE ANY LES. WL GO WITH JUST SCT FLURRIES OVER THE NW ZNS LATE TNGT. OTRW...EXPECT WINDY CONDITIONS DVLPG OVER THE KEWEENAW AS GFS SHOWS 30-40KT WINDS WITHIN MIXED LYR UNDER INVRN JUST BLO H85...IN GOOD AGREEMENT WITH OBSVD 40KT WINDS AT BIS AT 3K FT AGL. WENT WITH WIND ADVY OVER THE EXPOSED KEWEENAW PENINSULA AND A GALE WRNG OVER LK SUP THRU SUN MRNG. VARIOUS MOS TEMPS ARE SIMILAR SHOWING WELL ABV NORMAL MIN TEMPS...VERY RSNBL CONSIDERING UPSTREAM OBS AND EXPECTED STRG WINDS THAT WOULD LIMIT DIURNAL TEMP FALL IN SPITE OF ARRIVAL OF DRIER AIR.

ATLHOUGH W WINDS FCST TO DIMINISH A BIT ON SUN...GFS SHOWS GRADUAL INFLUX OF LLVL COLDER AIR WL CONTINUE THRU THE DAY WITH SLOWLY FALLING H100-85 THKNESS. GFS SHOWS INVRN BASE TEMP AT CMX FALLING TO NEAR -10C DURING THE DAY...MORE FVRBL FOR ICE NUCLEATION AND LES. SO WL MAINTAIN GOING 30 POP OVER THE NW ZNS. BUT FAIRLY DRY LLVL AIR WL LIMIT ANY POTENTIAL SN ACCUMULATION AND RESTRICT SHSN COVG.

GFS...WHICH HAD DVLPD THE MOST ROBUST WAVE OF LO PRES IN THE CNTRL GRT LKS SUN NGT...HAS TRENDED WEAKER AND FARTHER S WITH THIS SYS AND H6-7 FGEN...AND NOW HAS ZERO QPF OVER THE SRN TIER. UKMET/ECMWF ALSO SHOW HIER H7 RH. SO EXCEPT FOR SOME LES NR LK SUP IN AREAS FVRD BY WNW FLOW...WL GO WITH NOTHING MORE THAN A FEW FLURRIES. MORE LES ON MON-TUE MRNG IN THE WNW FLOW SN BELTS WITH PASSAGE OF LLVL THERMAL TROF...MAINLY DRY ELSEWHERE WITH LLVL DRY AIR AND ARRIVAL OF MORE ACYC FLOW. TUE MRNG LOOKS TO BE THE COLDEST IN THE NEAR FUTURE WITH SFC RDG AXIS/PWAT NR 0.1 INCH MOVING OVHD. EXPECT A DRY PD WITH SFC RDG DOMINATING AFT LES DEPARTS FM TUE AFTN THRU WED. SOME WAD CLD MAY IMPACT MAINLY THE NRN TIER OF ZNS DURING THIS TIME ON THE SRN FLANK OF SHRTWV MOVING ACRS FAR NRN ONTARIO.

ALTHOUGH EXTENDED MODELS CONTINUE TO SHOW SPLIT FLOW PATTERN ACRS NAMERICA MID TO LATE THIS COMING WEEK...GUIDANCE HAS TRENDED FARTHER N WITH THE SRN BRANCH DISTURBANCE THAT KICKS OUT OF THE DESERT SW INTO THE PLAINS ON WED AND INTO THE UPR GRT LKS ON FRI. NCEP MANUAL GUIDANCE PICKS UP NICELY ON THESE TRENDS...SO FOLLOWED ITS GUIDANCE TO INTRODUCE POPS ON THU/FRI WITH LES COMING IN ON SAT IN THE COLDER NW FLOW BEHIND THE DEPARTING LO INTO ONTARIO. FCST GFS THERMAL PROFILE SUGS A MIX OF PCPN WL OCCUR...WITH PROSPECT OF PCPN ARRIVING EARLY ON THU WHEN TEMPS MAY BE UNDER 32 WARRANTING MENTION OF CHC ZR AT THE ONSET OF PCPN.

COORDINATED WITH APX/GRB/DLH/ENVIRONMENT CAN.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...WIND ADVY MIZ001-003 06Z-17Z SUN. GALE WRNG LK SUP. &&

$$ KC

.UPDATE...

OVERALL CONDITIONS ARE BENIGN UNDER MAINLY CLOUDY SKIES ON YET ANOTHER MILD MID DECEMBER DAY. TWEAKED ALL GRIDS TO REFLECT CURRENT TRENDS. THE CONCERN OF DRY AIR IN MAJORITY OF TROPOSPHERE YDY HAS MATERIALIZED. BAND OF ISENTROPIC LIFT BROUGHT MAINLY NCNTRL AND EAST CWA A VERY BRIEF PERIOD OF LIGHT SNOW BEFORE DAYBREAK. OTHERWISE... ONLY PCPN OF NOTE THUS FAR IS OVR FAR N MN INTO ISLE ROYALE TIED TO SE FRINGE OF MAIN SHORTWAVE LOBE. ECHOES OVR W LK SUPERIOR INTO FAR WEST CWA ARE ELEVATED AND MAY BE PRODUCING VRY VRY LGT RA/SN. ALTHOUGH H85-H5 LAYER IS QUITE DRY...ADVECTION OF SUB H85 MOISTURE TO THE SW (SEE 12Z DVN PROFILE) MAY BOOST CHANCES OF PCPN THIS AFTN-EARLY EVENING. AT THE LEAST IT WILL KEEP LOW CLOUDS LOCKED IN PLACE OVR CNTRL/EAST ZONES. RUC/NAM SHOW ISENTROPIC LIFT WITHIN THE MOIST LAYER INCREASING BY 18Z OVR SCNTRL UPR MI AND SPREADING INTO EAST CWA BY 00Z. SOUNDINGS MAINLY SHOW LOW LEVEL MOISTURE...SO BASICALLY ANTICIPATE DRIZZLE IF ANYTHING. HOWEVER...LOW LEVEL MOISTURE ADVECTION COMBINES WITH WEAK MID LEVEL Q-VECTOR CONVERGENCE LATE TODAY-EARLY EVENING TO YIELD BETTER CHANCE OF SHOWERS OVR FAR SE CWA INTO EAST CWA. THIS IS QUITE SIMILAR TO RUC 13 QPF OUTPUT.

WINDS ARE OTHER CONCERN...MOSTLY OVR LK SUPERIOR AND N LK MICHIGAN WHERE LOW LEVEL INSTABILITY IS A BIT BETTER. 12Z TAMDAR SOUNDING FM KSAW INDICATED INVERSION NEAR H9 WITH NEUTRAL/UNSTABLE PROFILE BLO. SO FAR...WIND GUSTS TO 34 KT NOTED AT STDM4 AND NEAR 40KT AT PLATFORM JUST OFFSHORE OF MQT. RUC/NAM SOUNDINGS OVR LAKE SUPERIOR SHOWED LITTLE CHANGE IN THERMAL PROFILE THROUGH EARLY AFTN...SO OCCASIONAL GUSTS TO GALE FORCE REMAIN POSSIBLE AS CORE OF STRONGER H95-H9 WINDS PASS THROUGH. WINDS SHOULD DIMINISH QUICKLY LATE AFTN. ISSUED A GALE WARNING FOR EAST LAKE FOR AFTN.

UPDATED/PUBLISHED GRIDS OUT AS IS TEXT ZFPMQT UPDATE.

COORD WITH YYZ ON LAKE SUPERIOR FORECAST.

&&

.DISCUSSION (ISSUED AT 453 AM EST)...

UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE OVER THE UPPER GREAT LAKES WITH A TROUGH ACROSS THE NORTHERN ROCKIES INTO THE CANADIAN PRAIRIES AND TROUGHING ACROSS QUEBEC INTO NEW ENGLAND. THERE IS A CLOSED 500 MB LOW ACROSS CENTRAL SASKATCHEWAN THAT SHOWS UP WELL ON WATER VAPOR WITH STRONG CYCLONIC FLOW AND THERE IS SOME DARKENING PASSING ACROSS MONTANA AND WESTERN MANITOBA.

NAM TAKES THE CLOSED 500 MB LOW TO THE EAST TODAY ALONG WITH THE TROUGH AND THE TROUGH PUSHES EAST AND STAYS MOSTLY TO THE NORTH OF THE CWA. NAM ALSO BRINGS A TROUGH ONTO THE WEST COAST AND SPLITS THE TROUGH INTO THE NORTHERN AND SOUTHERN BRANCHES. THE SOUTHERN BRANCH CLOSED OFF A 500 MB LOW THAT REMAINS IN THE DESERT SW WHILE THE NORTHERN BRANCH HEADS EAST AND AFFECTS THE CWA MON NIGHT AND TUE.

FOR TODAY...NAM SHOWS 850-500 MB Q-VECTOR CONVERGENCE PASSING ACROSS THE CWA WITH 1000-500 MB RH STAYING MOSTLY TO THE NORTH OF THE AREA AND DOES NOT PUT OUT ANY QPF FOR THE CWA. KMPX...KGRB AND KINL 00Z SOUNDINGS ARE VERY DRY IN THE LOW TO MID LEVELS AND THIS DRY AIR WILL HAVE TO BE OVERCOME BEFORE WE CAN SEE ANY PCPN. NAM SHOWING STRONG ISENTROPIC LIFT AND LIMITED MOISTURE IN THE MID LEVELS ON I290-I305K SURFACES...BUT THE LOW LEVELS REMAIN MOSTLY DRY AND THE LIFT AND MOISTURE DEPART TONIGHT. GFS SHOWS ABOUT THE SAME THING...BUT IS A LITTLE MORE GENEROUS WITH ITS QPF AND WITH THE MOISTURE. WILL KEEP LOW CHANCE POPS IN THE FORECAST FOR TODAY AS MOISTURE MOVES ACROSS WITH SOME DYNAMICS. MOISTURE IS LIMITED THOUGH. WILL KEEP SLEET MENTION IN THE FORECAST...BUT IS HARD TO TELL WHAT WILL HAPPEN. EARLIER LOOK AT TAMDAR SOUNDINGS FROM KMPX...KABR...KOAX SHOWED ABOVE FREEZING TEMPERATURES WITH A WARM AND DRY LAYER ALOFT AND THE FURTHER WEST YOU WENT...THE WARMER THE TEMPERATURES. TAMDAR SOUNDINGS FROM KRHI...KCMX...KBJI...KHIB AND KMQT SHOWED TEMPERATURES ALL BELOW ZERO. WILL GO WITH SNOW AND SLEET CHANGING OVER TO RAIN FOR PCPN TYPE FOR TODAY.

FOR TONIGHT...LAKE EFFECT GETS GOING AFTER MIDNIGHT...BUT OVERALL IS NOT GOING TO AMOUNT TO MUCH AS 850 MB TEMPERATURES DROP TO MARGINAL LEVELS AND NAM BUFKIT SOUNDINGS FROM KCMX...KMQT AND KERY SHOW LOW INVERSION HEIGHTS AND WINDS OUT OF THE WEST. ONLY SPOTS TO BE AFFECTED WITH SNOW SHOWERS OR FLURRIES WILL BE WEST FACING SHORELINES OF LAKE SUPERIOR. THERE COULD ALSO BE SOME DRY AIR ADVECTED ACROSS THE LAKE WHICH WILL ALSO MAKE A DENT IN THE COVERAGE AND INTENSITY OF ANY LAKE EFFECT SHOWERS THAT ARE ABLE TO BE CREATED AFTER MIDNIGHT AS TEMPERATURES ARE NOT COLD ENOUGH BEFOREHAND.

NAM BRINGS BACK IN SOME 850-500 MB Q-VECTOR CONVERGENCE SUN NIGHT AND MON MORNING...BUT DEEP MOISTURE IS REALLY NOT THERE. MORE 850-500 MB Q-VECTOR CONVERGENCE RETURNS MON NIGHT...BUT AGAIN DEEP MOISTURE REALLY IS NOT THERE. WILL CONTINUE WITH THE LOW CHANCE POPS WITH BETTER LAKE EFFECT CONDITIONS ARRIVING SUNDAY NIGHT WITH THE SHORTWAVE AND MUCH COLDER AIR COMING DOWN ACROSS LAKE SUPERIOR. THE SHORTWAVE SHOULD HELP RAISE INVERSION HEIGHTS AND THE COLDER TEMPERATURES DOWN TO -8C TO -10C WILL BE ENOUGH FOR LAKE EFFECT TO KICK UP. INVERSION HEIGHTS THOUGH STAY BELOW 5000 FEET ACCORDING TO GFS BUFKIT SOUNDINGS...SO THINGS SHOULD NOT GET TOO OUT OF HAND FOR THE LAKE EFFECT SNOW.

OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES EXCEPT LOWERED HIGHS SLIGHTLY AND WENT CLOSER TO ADJENS AND ADJMEL FOR LOWS.

&&

.MQT WATCHES/WARNINGS/ADVISORIES... GALE WARNING THIS AFTN EAST 1/2 LAKE SUPERIOR. &&

$$

UPDATE...JLA DISCUSSION...MICHELS