000
FXUS63 KIWX 032035
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
335 PM EST WED DEC 3 2008
.SHORT TERM...
BAND OF SNOW CONTS TO MOVE SLOWLY SE BEHIND CDFNT WHICH EXTENDED
FROM NEAR MKG-PIA AT 19Z. 88D MOSAIC ALSO SHOWING SCT SHOWERS DVLPG
IN THE LOW LEVEL MOISTURE TO THE SOUTH OVER MO AND THE OH VALLEY.
12Z NAM CONTS TO INDICATE STRONG FGEN FORCING ALONG FRONT THIS
EVE...BUT HAS SHIFTED THIS TO THE SW-S AND CAME UP WITH CONSIDERABLY
LESS QPF OVER OUR AREA THAN PREVIOUS RUN AND ASSOCIATED MOS POPS
FALLING FROM CATEGORICAL TO CHC WHILE MORNING GFS APPEARS TO BE WAY
OVERDONE WITH THE PREFRONTAL MOISTURE SURGE/QPF. IR STLT LOOPS
INDICATE TOPS ARE WARMING OVER THE SNOW BAND TO THE NW WITH SOME
DIMINISHING TRENDS ALSO ON RADAR...ESPCLY OVER SE WI. EVEN SO...
GIVEN THE WIDESPREAD MODERATE SNOW REPORTS IN THIS BAND...EXPECT IT
WILL PERSIST AT LEAST INTO OUR CWA WITH A SHORT PD OF SGFNT SNOWFALL
WITH VSBYS OF 1/2 TO 1MI PSBL... ESPCLY NWRN PORTION OF CWA THIS
EVE. ALSO LIGHT RAIN DVLPG IN LOW LEVEL THETA-E ADVECTION AREA AHEAD
OF FRONT OVER SERN PORTION OF CWA. THUS LITTLE CHANGE MADE TO SHORT
TERM GRIDS WITH CATEGORICAL POPS OF RAIN CHANGING TO SNOW THIS EVE
AND ACCUMS OF 1-2" NW TO LITTLE OR NONE SE. SUBSIDENCE AND DRYING
WILL OVERSPREAD THE AREA LATE TONIGHT CAUSING SNOW TO TAPER
OFF...EXCEPT SE OF LM WHERE NW FLOW AND DELTA T`S IN TEENS SHOULD
ALLOW SOME LAKE EFFECT SNOW SHOWERS TO CONT...THOUGH AMOUNTS LIKELY
LIGHT AS INVERSION/LAKE INDUCED EQL QUITE LOW. TEMPS UPSTREAM THIS
AFTN SUPPORT LOWS CLOSE TO 12Z MOS FROM MID 20S EAST TO UPPER TEENS
WEST.
ON THU...EXPECT LOW LEVEL MOISTURE WILL REMAINED TRAPPED BENEATH
INVERSION. THIS WILL RESULT IN ANY CLEARING OVERNIGHT TO QUICKLY
FILL IN AS LOW LEVELS LAPSE RATES REMAIN LARGE. LAKE EFFECT SNOW
SHOWERS SHOULD CONT AS H85 CAA PERSISTS. ACCUMS AGAIN HWVR EXPECTED
TO BE LIGHT AS INVERSION REMAINS QUITE LOW.
LAKE INDUCED INSTABILITY EXPECTED TO INCREASE A BIT THU NIGHT AS H85
TEMPS FALL TO AROUND -17C...BUT THIS SHOULD BE COUNTERACTED BY MEAN
CLOUD LAYER WINDS BACKING FROM 300DEG TO 280DEG OVERNIGHT. EXPECT
CONDITIONS FAVORABLE ENOUGH TO GO LIKELY POPS ACROSS SRN MI COUNTIES
BUT KEPT ACCUMS LIGHT. OTRWS IT WILL BE A COLD NIGHT WITH SKIES
BECOMING PARTLY CLOUDY...ESPCLY ACROSS SRN PORTIONS OF THE CWA...AND
TEMPS FALLING INTO THE TEENS.
&&
.LONG TERM...
FRIDAY THROUGH WEDNESDAY.
LAKE EFFECT SNOWSHOWERS WILL BE WINDING DOWN AT THE START OF THE
PERIOD WITH MAIN EXTENT ACROSS OUR MICHIGAN COUNTIES. MODELS HAVE
CONTINUED TO TREND TOWARDS THE BULK OF THE PRECIP WITH THE SYSTEM
NOT ARRIVING TILL LATER FRI NGT INTO SATURDAY. NEW MAV/MET 12Z
GUIDANCE ACTUALLY SHOWING 15 TO 25 PERCENT POPS. MAIN LOW STILL
LOOKS TO PASS NORTH OF THE FORECAST AREA...WHICH SHOULD STILL GIVE
SOME LGT SNOW TO THE AREA BUT KEEPING THE HIGHER AMOUNTS FURTHER
NORTH IN TERMS OF THE SYNOPTIC SNOW. AT THIS TIME WILL NOT DO
ANYTHING WITH REMOVING POPS/TONING DOWN INTO SATURDAY. LAKE EFFECT
ONCE AGAIN WILL TAKE SHAPE IN THE WAKE OF THE SYSTEM..WITH GRIDS
HAVING A GOOD HANDLE ON THINGS NOW.
AMOUNT OF UNCERTAINTY BEGINS TO INCREASE BEYOND THIS TIME FRAME WITH
CARVING OUT OF TROUGH AND PHASING OF SYSTEMS FOR THE MONDAY INTO
TUESDAY SYSTEM. ALL MED RANGE MODELS DO TEND TO KEEP THE NORTHERN
STREAM SYSTEM THE STRONGER ONE WITH NO SIG PHASING. WILL MAINTAIN
GRIDS AS IS AS A RESULT FOR NOW AS SUSPECT THEY COULD POTENTIALLY
COME BACK TO A PHASING SOLUTION WITH TIME.
FINAL CHALLENGE WILL BE WITH WHEN THE MODELS DO NOW INDICATE PHASING
OF THE FLOW AND A DECENT SYSTEM DEVELOPING. SOLUTIONS RANGE FROM NW
OF THE AREA TO ALONG THE EAST COAST...MUCH LIKE THE LAST MAJOR STORM
SYSTEM THAT ENDED UP CAUSING MORE ISSUES TO OUR NW THAN US. GIVEN
CONCERNS OF A SIMILAR SETUP WITH BOTH THE MONDAY SYSTEM AND THEN
THIS ONE...WILL LEAVE TUES NGT INTO WEDS DRY AT THIS POINT.
TEMP WISE PATTERN WILL STAY ON THE COOLER SIDE WITH THE BRIEF WARM
UP TO AROUND OR MAYBE SLIGHTLY ABOVE FREEZING AHEAD OF THE SYSTEM AT
THE END OF THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1248 PM EST WED DEC 3 2008/
AVIATION...
LOW CLOUDS WERE MOVG NORTH ACROSS INDIANA THIS AFTN
AND SHOULD CONT AT FWA AND REACH SBN BY 12Z. WITH FROPA THIS EVE
CIGS/VSBYS EXPECTED TO LOWER TO IFR IN SNOW. PRECIP SHOULD END
RATHER QUICKLY...BY 05Z AT SBN AND 08Z AT FWA... THOUGH SOME LAKE
EFFECT FLURRIES MAY LINGER AT SBN BEYOND THAT TIME. LOW LEVEL
MOISTURE EXPECTED TO REMAIN TRAPPED BENEATH INVERSION RESULTING IN
CONTD MVFR CIGS THROUGH REMAINDER OF THE TAF PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EST FRIDAY
FOR LMZ043-046.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...FISHER
AVIATION...TAYLOR
