651 
FXUS63 KIWX 142016
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
416 PM EDT THU MAR 14 2013

.SHORT TERM... /THROUGH FRIDAY NIGHT/

CLIPPER SYSTEM WAS QUICKLY SHIFTING SE ACROSS ILLINOIS WITH AN AREA 
OF LIGHT PRECIP. NE FRINGE OF THE PRECIP HAS BEEN ERODING RATHER 
NICELY WITH DRY LOW LEVELS NOTED ON SOUNDINGS. STILL A SMALL WINDOW 
BETWEEN 4 AND 7 PM EDT THAT SOME LIGHT SNOW OR RAIN COULD OCCUR IN 
FAR SW AREAS BUT ALL IN ALL THINGS ARE ON TRACK.

HIGH CLOUDS WILL REMAIN ACROSS MUCH OF THE AREA TONIGHT WITH DRY 
CONDITIONS TO PREVAIL UNTIL TOMORROW WHEN ANOTHER FAST MOVING...BUT 
MORE DYNAMIC CLIPPER WILL MOVE THROUGH THE REGION. A FRONTAL 
BOUNDARY WILL SET UP ACROSS THE AREA IN THE WAKE OF THE FIRST SYSTEM 
AND HELP ADD TO CONVERGENCE ACROSS PORTIONS OF WISCONSIN AND MI 
BEFORE SHIFTING SOUTH AS THE NW ENERGY DROPS IN. MODELS HAVE BEEN 
FAIRLY CONSISTENT ON PRECIP MOVING ALONG AND NORTH OF THIS 
FEATURE...BUT THE EXACT TRACK AND PTYPE HAS REMAINED UNCLEAR. AT 
THIS POINT THE SFC LOW WOULD LOOK TO PASS SOMEWHERE NORTH OF THE 
OHIO RIVER BY SATURDAY MORNING. A GOOD DEAL OF WARM AIR WILL BE 
ACROSS THE AREA ON FRIDAY WITH TEMPS LIKELY INTO THE 40S. LIGHT RAIN 
MAY BEGIN TO MOVE IN DURING THE AFTERNOON ACROSS THE NORTH BUT BULK 
OF PRECIP WOULD APPEAR TO FALL FRIDAY NIGHT. HAVE WENT WITH HIGHER 
END CHC OR LOW END LIKELY MUCH LIKE PREV SHIFT BUT EXPANDED LIKELY 
POPS FURTHER SOUTH. HAVE ALSO TRIED TO ADD SOME DETAIL ON PTYPE 
USING 09Z SREF WHICH SEEMED TO BE A GOOD COMPROMISE. WITH TEMPS 
FRIDAY NIGHT LIKELY TO REMAIN ABOVE FREEZING IN THE SOUTH...LITTLE 
ACCUM POTENTIAL IS EXPECTED. LOCATIONS ACROSS THE 
NORTH...HOWEVER...COULD SEE LIGHT ACCUMS ASSUMING THE RAIN QUICKLY 
CHANGES TO SNOW. WITH THE WARM DAY...COULD EVEN BE A STRUGGLE IN THE 
NORTH FOR SNOW ACCUMS. 

&&

.LONG TERM... /SATURDAY THROUGH THURSDAY/
SYSTEM STREAKS RAPIDLY EWD THROUGH THE OH VLY INTO THE MIDALT FRIDAY 
NIGHT INTO SAT AMID RAPID FLAT ERN CONUS MIDTROP FLOW TO ASSURE A 
FLUID EXODUS OF PRECIP SAT AM. SHOULD TREND CONT PSBL EXCLUSION OF 
RATHER NOMINAL CHCS SAT AM ACRS ERN CWA MAY BETTER CAPTURE RAPID 
SWITCH TO FERVENT DVM AND DRY CP AIRMASS ADVANCES AS NWRN CANADIAN 
SOURCED   RIDGING SETTLES SEWD IN WAKE. 150W ENERGY TO PROVIDE DRIVE 
NEG TILTED INTO NRN/CNTL ROCKIES BY SUN AFTN AND AFFORD MULTIPLE 
CYCLOGENETIC RESPONSE FM NRN PLAINS/WY PLATEAU SWD INTO ERN NM/WRN 
TX. SIG DEGREE OF UNEASINESS WRT POTNL FOR PHASING OF NRN/SRN LLVL 
FEATURES. AT PRESENT SLOWER/STRONGER NRN STREAM CYCLONE SLIGHTLY 
FAVORED WITH STRONGEST MIDLVL SUPPORT/5H FALLS WITH A PRIOR/RAPID 
SRN STREAM EJECTION INTO THE OHIO VLY LT SUNDAY NIGHT. LEADING EDGE 
ADVANCEMENT TO BE STYMIED BY INITIAL HIGH SUBCLOUD CPDS. EVAP 
COOLING/COLD T/TW PROFILES TO SUPPORT LIGHT SNOW SPCLY ACRS SRN CWA 
SUNDAY NIGHT. THEREAFTER TIMING OF CHANGEOVER TO LIQUID AND POPS ON 
DY5 STRONGLY TIED TO DEGREE OF NWD THETA-E FLUX/NRN STREAM OVERTAKE. 
CONTD MIDDLE OF ROAD POPS/ALBEIT TARGETING MON AFTN SLIGHTLY HIR POPS
WITH MEDIOCRE CONSENSUS AGREEMENT TO FULL CHANGEOVER ENTIRE CWA. 
POTNL RETURN TO LES EFFECTS TUE/TUE NIGHT AND TARGETED POPS MORE 
ASSERTIVE TO LEE OF LK MI VERSUS BLENDED APPROACH WITH CYCLONIC 
925-8H FLOW/DELTA T INTO UPR TEENS TO LKLY PROVE SUFFICIENT FOR LK 
RESPONSE. ANOTHER DRY/CP AIRMASS TO OVERSPREAD WRN GRTLKS RAPIDLY 
MIDWEEK AS ENERGY TRANSFER TO COAST TRANSPIRES.

&&

.AVIATION...
FAST MOVING AREA OF LIGHT RAIN/SNOW WILL IMPACT MAINLY PORTIONS
OF ILLINOIS INTO WCNTRL INDIANA THIS AFTERNOON. BOTH SOUTH BEND
AND FT WAYNE WILL REMAIN REMOVED FROM ANY MEASURABLE PRECIP AND
IMPACTS TO FLGT CONDITIONS. CLOUDS WILL INCREASE AS THE SYSTEM
PASSES BY BUT POSE NO ISSUES. NEXT SYSTEM WITH GREATER POTENTIAL
TO IMPACT FLIGHT CONDITIONS WILL NOT ARRIVE TILL OUTSIDE THE VALID
TAF PERIOD.

&&

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

$$

SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER