Midwest & Ohio Valley Winter 2010

[Dave]

Might as well bring up a thread for up here in this part of the country as well. Looks like a snow & bitter cold week times ahead. Forecasts from NWS Indianapolis IN & Louisville KY.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
625 PM EST MON JAN 4 2010

.AVIATION...DISCUSSION FOR 00Z TAFS.

OVERVIEW...MVFR TO VFR CEILINGS CONTINUE.

SURFACE ANALYSIS EARLY THIS EVENING SHOWS HIGH PRESSURE STILL
CENTERED OVER IOWA AND MINNESOTA...POURING A CONTINUED FLOW OF COLD
AIR ACROSS THE TAF SITES. LAKE TRAJECTORIES INDICATE THE LAKE
FLURRIES HAVE SHIFTED TO THE NORTHEAST OF THE TAF SITES.

MODEL LOWER LEVEL MOISTURE FIELDS INDICATE CLOUDS ACROSS NORTHERN
INDIANA AND LOWER MICHIGAN WILL SINK SOUTHWARD ACROSS CENTRAL
INDIANA THROUGH THE NEXT 24 HOURS...RESULTING IN MVFR CEILINGS
RETURNING TO THE TAF SITES. THESE CEILINGS SHOULD RETURN TO LAF AND
IND FIRST BEFORE REACHING HUF AND BMG LATER. TIME SECTIONS AND
FORECAST SOUNDINGS INDICATE SATURATION REMAINING IN THE LOWER LEVELS
OF THE ATMOSPHERE THROUGH THE PERIOD.

&&

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...
UPPER LEVEL TROUGH AXIS SHIFTING SOUTH THROUGH THE OHIO VALLEY THIS
AFTERNOON. AREA OF VORTICITY ASSOCIATED WITH THE TROUGH ALONG WITH A
PERSISTENT LAKE MICHIGAN SNOW BAND CONTRIBUTING TO WIDESPREAD AREA
OF LIGHT SNOW ACROSS NORTHEAST COUNTIES. OUTSIDE OF THIS AREA THERE
WERE POCKETS OF FLURRIES EAST OF THE I-65 CORRIDOR. SKIES REMAINED
MAINLY SUNNY FOR MANY LOCATIONS SOUTHWEST OF THE INDY METRO.

FORECAST CHALLENGES IN THE SHORT TERM FOCUS ON CHANCES FOR
FLURRIES/LIGHT SNOW INTO TUESDAY AND EXPECTED TEMPERATURES. HAVE
LEANED TOWARDS NAM/SREF FOR MAIN WEATHER FEATURES.

MORE EXTENSIVE SNOWFALL REMAINS TO THE EAST OVER OHIO THIS AFTERNOON
WHERE AVAILABLE FORCING IS A BIT MORE ROBUST. HOWEVER WITH THE
COMBINATION OF THE SNOW BAND STREAMING SOUTHEAST OFF LAKE MICHIGAN
HAS HELPED STEADIER SNOWFALL TO EXPAND BACK INTO AREAS EAST OF A
KOKOMO-RUSHVILLE LINE. BOTH THE CURRENT RUC AND 12Z NAM INDICATE LOW
LEVEL WIND FIELDS WILL REMAIN FAVORABLE FOR SCATTERED SNOW SHOWERS
TO PERSIST IN THESE AREAS THIS EVENING AND POSSIBLY WELL INTO THE
OVERNIGHT. EXPECT SNOW WILL BE GREATEST IN COVERAGE ACROSS NORTHEAST
COUNTIES WHERE A LIGHT ACCUMULATION UP TO AN INCH STILL APPEARS
POSSIBLE THROUGH TONIGHT. TO THE SOUTHWEST OF THIS AREA...FLURRIES
WILL LINGER THROUGH THE NIGHT AS WELL IMPACTING MUCH OF THE INDY
METRO. DEEPER MOISTURE WILL MAKE A MORE CONCERTED PUSH SOUTH ACROSS
THE FORECAST AREA TONIGHT WITH RESULT THAT MOST AREAS SOUTHWEST OF
THE METRO SHOULD BECOME MOSTLY CLOUDY.

LOW LEVEL WIND FIELDS REMAIN INITIALLY FAVORABLE FOR CONTINUED SNOW
SHOWERS ACTIVITY NORTHEAST OF THE METRO TUESDAY MORNING...BUT THE
TREND FOR THE DAY SHOULD BE A GRADUAL DIMINISHING OF COVERAGE TO
SNOW SHOWERS AND FLURRIES AS LOW LEVEL WINDS WEAKEN AND BACK BY THE
AFTERNOON. NOT ANTICIPATING ANY ACCUMULATIONS AS NATURE OF THE SNOW
SHOULD BE EVEN LIGHTER THAN TODAY. CLOUD COVER HOWEVER WILL BE SLOW
TO DEPART AS MODEL SOUNDINGS CONTINUE TO INDICATE ONLY A SLOW
EROSION FROM THE SOUTHWEST. EXPECT MORE SCATTERING OF THE CLOUDS BY
TUESDAY NIGHT AS HIGH PRESSURE FINALLY WORKS INTO CENTRAL INDIANA
FROM THE WEST.

TEMPS...HAVE ONCE AGAIN TRENDED TOWARDS THE COLDER MET GUIDANCE
THROUGH TUESDAY NIGHT. LOWS TONIGHT SHOULD BE WARMER OVERALL THAN
LAST FEW NIGHTS WITH MORE CLOUDS ANTICIPATED. TEMPERATURES WILL BE
MAINLY IN THE LOWER 20S TUESDAY.


.LONG TERM...
THE FOCUS OF THE EXTENDED CONTINUES TO BE THE CLOSED UPPER LOW
THAT WILL BRING SNOW ACCUMULATIONS TO THE FORECAST AREA ON
THURSDAY.

MODELS ARE BEGINNING TO COME INTO BETTER AGREEMENT ON THE TRACK OF
THE SYSTEM AS OPPOSED TO PREVIOUS RUNS. THE GFS CONTINUES TO BE
THE OUTLYING MODEL...TAKING THE TRACK OF THE SYSTEM A LITTLE
FASTER AND TO THE SOUTH OF INDIANA THAN THE OTHER MODELS. THE
ECMWF HAS COME INTO LINE WITH THE GEM...AND THE NAM IS TURNING OUT
AS EXPECTED...ALL TAKING A MORE NORTHERN TRACK. THIS WOULD PUT THE
FORECAST AREA RIGHT UNDER THE LEFT EXIT REGION OF A STRONG UPPER
LEVEL JET...AROUND 100 TO 150 KTS.

FRONTOGENETIC FORCING CONTINUES TO BE DECENT IN THE MID
LEVELS...BUT THE MAIN PROBLEM CONTINUES TO BE THE LACK OF
MOISTURE. THE ARCTIC AIRMASS OVER THE AREA IS DEFINITELY
INHIBITING PWATS....QPFS ARE RANGING BETWEEN 0.15 TO 0.25.
NONETHELESS...THE SNOWFALL COULD START AS EARLY AS WEDNESDAY NIGHT
AND INTO THURSDAY NIGHT...SO THE DURATION OF THE SYSTEM WILL PLAY
A BIG ROLE IN THE SNOW AMOUNTS. CURRENTLY...STILL THINKING IN THE
3 TO 5 INCH RANGE.

IN ADDITION TO THE SNOW...THIS SYSTEM WILL BRING A SURGE OF VERY
COLD AIR BEHIND IT...DROPPING TEMPERATURES BACK DOWN INTO THE
SINGLE DIGITS AND WIND CHILLS WELL BELOW ZERO. WENT SLIGHTLY BELOW
GUIDANCE THROUGH ENTIRE EXTENDED PERIOD...FRESH SNOW COVER WILL
ALSO CONTRIBUTE TO THE COLDER TEMPERATURES.

&&

http://forecast.weather.gov/product.php?site=IND&issuedby=IND&product=AFD&format=CI&version=1&glossary=1

[Dave]

<b>NWS Louisville KY</b>

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
311 PM EST MON JAN 4 2010

.SHORT TERM (TONIGHT AND TUESDAY)...

EXPECT ACCUMULATING LIGHT SNOW TO MOVE INTO PRIMARILY OUR NERN MOST
COUNTIES TNGT...FROM LEX N AND E AS UPR LEVEL TROF MOVES THRU AND A
LOW LEVEL FETCH OFF THE LOWER GREAT LAKES CONTINUES. ALL MODELS ARE
CONSISTENT WITH PAINTING QPF FROM A FEW HUNDREDTHS TO AROUND .05
OVER THIS AREA AS MOISTURE DEEPENS INTO THE MID LAYERS...ACCOMPANIED
BY WEAK LIFT IN THE LOWER/MID LEVELS. WITH LIQUID TO SNOW EQUIVALENT
OF ABOUT 20/1...DRY FLUFFY SNOW COULD ACCUMULATE TO AN INCH OR SO
ACROSS PRIMARILY HARRISON...NICHOLAS...BOURBON AND CLARK COUNTIES
WITH LESSER AMOUNTS TO THE WEST. WILL ISSUE A SPECIAL WEATHER
STATEMENT FOR THE LEX VCNTY.

MODEL CROSS SECTIONS SHOW MOISTURE BECOMING MORE SHALLOW AFTER 12Z
TUE...AT THAT TIME WILL BE DECREASING POPS TO CHC THRU THE MRNG AND
FLURRIES IN THE AFTN EAST.

TEMPS WILL BE HELD UP AGAIN SOMEWHAT TNGT BY CLDS WITH MINS AGAIN IN
THE TEENS. MID/UPPER 20S EXPECTED AGAIN TUE...WARMEST IN THE SW...
WITH THE MOST SUNSHINE.

.LONG TERM (TUESDAY NIGHT - MONDAY)...

COLD AND SNOW EARLY IN THE EXTENDED PERIOD...FRIGID COLD THEREAFTER
FOR THIS COMING WEEKEND.

TUESDAY NIGHT - THURSDAY...

WE/LL START OFF TUES NIGHT WITH SOME LINGERING FLURRIES IN THE NE
FORECAST AREA. THESE WON/T LAST LONG AS MOISTURE DECREASES BY
6Z...ALLOWING THE REST OF THE NIGHT TO BE DRY.

THE MAIN SNOW MAKER DURING THE LONG TERM PERIOD WILL COME WED NIGHT
THROUGH THURS AS A STRONG H5 CLOSED LOW DROPS DOWN INTO THE
MIDWEST. THE MAJORITY OF THE MID RANGE MODELS TRACK THIS LOW ACROSS
NORTHERN IL/IN THURS/THURS NIGHT. A FEW VARIATIONS WITH THE LOW
TRACKING FURTHER SOUTH STILL EXIST ESPECIALLY WITH THE 12Z OP GFS.
DESPITE THESE DIFFERENCES...THE END RESULT IS FAIRLY SIMILAR WITH A
WIDESPREAD 0.1 TO 0.25 INCHES OF QPF FALLING OVER THE AREA. WITH
SNOW RATIOS IN 15:1 TO 20:1 RANGE AND WITH THE PROJECTED QPF FROM
THE 12Z MODELS...SNOW ACCUMS FOR WED NIGHT - THURS NIGHT LOOK TO BE
IN THE 2-4 INCH RANGE AT THIS TIME. WE/RE STILL 4 DAYS OUT FROM
THIS EVENT SO THIS FORECAST COULD DEFINITELY CHANGE...BUT THAT/S THE
BEST ESTIMATE AT THIS POINT. STAY TUNED FOR THE LATEST FORECAST
UPDATES OVER THE NEXT FEW DAYS.

AS FOR TEMPS...WE/LL BE IN THE MID 20S FOR HIGHS WED/THURS. WE/LL
SEE THE MID TEENS FOR LOWS ON TUES NIGHT...THEN A SLIGHTLY MILDER
NIGHT IN THE UPPER TEENS TO AROUND 20 WITH THE LIGHT SNOW WED
NIGHT...THEN BACK DOWN INTO THE LOWER TEENS FOR LOWS FOR THURS NIGHT.

FRIDAY - SUNDAY...

ON FRIDAY...MAIN STORM SYSTEM MOVES OFF THE EAST COAST WITH
NORTHERLY FLOW ALOFT OVER THE OH VALLEY. MODELS SUGGEST THIS WILL
KEEP AMPLE LOW-LEVEL MOISTURE IN PLACE OVER OUR AREA FOR SCT TO
PERHAPS NUMEROUS SNOW SHOWERS FRIDAY AND FRIDAY NIGHT...WITH
ADDITIONAL LIGHT ACCUMULATIONS POSSIBLE. SOME LEFTOVER SNOW SHOWERS
OR FLURRIES SHOULD OCCUR SATURDAY.

THE STORM ON THURSDAY WILL ALSO USHER IN A SURGE OF FRIGID ARCTIC
AIR. THIS ALONG WITH CLOUD COVER SHOULD KEEP DAYTIME HIGHS ON FRIDAY
AND SATURDAY IN THE TEENS IN MOST PLACES. LOW TEMPS SATURDAY MORNING
SHOULD BE IN THE SINGLE DIGITS...HELD UP A LITTLE BY CLOUD COVER.
HOWEVER...WIND CHILL TEMPS SATURDAY MORNING WILL RANGE FROM AROUND 3
TO 10 DEGREES BELOW ZERO. WIND CHILLS DURING THE DAY SATURDAY SHOULD
ONLY BE IN THE SINGLE NUMBERS.

BY SUNDAY MORNING...CLOUDS SHOULD AT LEAST PARTIALLY CLEAR OUT AS
ARCTIC HIGH PRESSURE AT THE SURFACE NUDGES INTO THE OH VALLEY. THIS
WILL SEND ACTUAL AIR TEMPS PLUMMETING TO 0 TO 4 ABOVE ZERO SUNDAY
MORNING...CERTAINLY BELOW MOS GUIDANCE...WITH SOME VALLEY LOCATIONS
AT OR BELOW ZERO. WHATEVER SNOW COVER IS ON THE GROUND SUNDAY
MORNING WILL FACILITATE THE FRIGID TEMPS. WIND CHILLS WILL
AGAIN BE BELOW ZERO.

DURING THE DAY SUNDAY...HIGH PRESSURE TAKES CONTROL WITH SUNSHINE
EXPECTED. THE HEART OF THE COLD AIR STARTS TO SLIDE EAST.
NEVERTHELESS AFTERNOON MAX TEMPS SUNDAY AFTERNOON WILL STILL BE VERY
COLD WITH HIGHS IN THE UPPER TEENS AND LOWER 20S. TEMPS WILL
MODERATE THROUGH THE 20S FOR HIGHS ON MONDAY.

TAKE NECESSARY PRECAUTIONS TO PROTECT YOURSELF...YOUR FAMILY...AND
YOUR PETS FROM THE FRIGID COLD LATE THIS WEEK.

http://forecast.weather.gov/product.php?site=LMK&issuedby=LMK&product=AFD&format=CI&version=1&glossary=1

[Dave]

Winter Storm Watch for thursday including the Indianapolis IN, Louisville KY, and Wilmington OH districts.



NWS Indianapolis IN

http://www.crh.noaa.gov/ind/

NWS Louisville KY

http://www.crh.noaa.gov/lmk/

NWS Wilmington OH

http://www.erh.noaa.gov/iln/

[Dave]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
404 PM EST TUE JAN 5 2010

.SHORT TERM...
THE MAIN FOCUS OF THE SHORT TERM IS THE WINTER STORM EXPECTED TO
MOVE INTO CENTRAL INDIANA LATE WEDNESDAY NIGHT THROUGH FRIDAY MORNING.

PERHAPS THE BIGGEST CHANGE IN THE MODELS WAS AN INCREASE IN
MOISTURE IN THE LATEST RUNS. HPC GUIDANCE IS PREDICTING TOTAL SNOW
ACCUMULATIONS IN THE 4 TO 6 INCH RANGE. THE ECMWF HAS ALSO COME
INTO AGREEMENT WITH THE NAM IN REGARD TO QPFS...BOTH INDICATING
AMOUNTS BETWEEN 0.25 AND 0.35. IN ADDITION...ISENTROPIC LIFT LOOKS
MORE IMPRESSIVE TODAY.

TIMING OF SYSTEM IS BECOMING NARROWED DOWN. IT APPEARS THE THU
12Z TO THU 18Z TIME FRAME WILL BE THE HEAVIEST PERIOD OF SNOW.
STARTING TIME IS EXPECTED TO BE AROUND THU 09Z/THU 12Z. SO...THE
MORNING RUSH HOUR WILL BE HAZARDOUS. THE NAM AND ECMWF ARE A BIT
SLOWER THAN THE GFS/GEM IN THE START TIME. AS FAR AS END
TIME...ANTICIPATE IT TO TAPER OFF RATHER QUICKLY THURSDAY
AFTERNOON AS ISENTROPIC LIFT CUTS OFF ACROSS SOUTHERN INDIANA.
HOWEVER...LIGHT SNOW WILL CONTINUE ON THE BACK SIDE OF
LOW...POSSIBLY RESULTING IN ANOTHER INCH OF SNOW THROUGH FRIDAY
MORNING.

AS FAR AS FORCING...THE UPPER LEVEL JET IS STILL OVER 100 KTS.
FRONTOGENESIS IS DECENT IN THE MID LEVELS ACROSS ALL MODELS...WITH
THE GEM SHOWING AN INCREASE IN THE LOWER LEVELS AS WELL.

IMPACTS OF THE STORM WILL CARRY OVER INTO FRIDAY AS THE NORTHWEST
WINDS INCREASE BEHIND THE LOW. THE WINDS COULD GUST UP TO 30 MPH
AT TIMES. IT WILL BE A LIGHT SNOW...SO BLOWING AND DRIFTING SNOW
WILL BECOME A PROBLEM.

TEMPS...GENERALLY WENT WITH A BLEND OF THE MODELS...BUT ON THE
LOWER SIDE OF THEM. TEMPERATURES WILL BE A BIT WARMER AS THE
SYSTEM GOES THROUGH...BUT ARCTIC AIR WILL FILTER IN BEHIND
IT...BRINGING TEMPS BACK DOWN INTO THE SINGLE DIGITS AND DANGEROUS
WIND CHILLS WELL BELOW ZERO BY THE END OF THE WEEK.


.LONG TERM...SATURDAY THROUGH TUESDAY...
IN WAKE OF THE SNOW THURSDAY AND FRIDAY...THE MAIN FOCUS THROUGH THE
PERIOD WILL BE THE POTENTIAL AT VERY COLD TEMPERATURES FOR THE
WEEKEND WITH ONLY SLOW MODERATION INTO EARLY NEXT WEEK. WIND FIELDS
REMAIN SUPPORTIVE OF SOME LAKE ENHANCED SNOW SHOWERS/FLURRIES FOR
SATURDAY OVER EASTERN HALF OF THE FORECAST AREA...BUT WINDS QUICKLY
BACK BY SATURDAY NIGHT AS HIGH PRESSURE BECOMES ESTABLISHED OVER THE
OHIO VALLEY. MODEL CONSENSUS INDICATING SKIES SHOULD CLEAR SATURDAY
NIGHT WHICH WOULD LIKELY SET THE TABLE FOR POTENTIALLY THE COLDEST
NIGHT OF THE SEASON TO DATE. WITH HIGH CONFIDENCE IN SEVERAL INCHES
OF SNOW ON THE GROUND...FELT COMFORTABLE IN DROPPING LOWS BELOW ZERO
FOR MUCH OF THE FORECAST AREA. AT THIS POINT...HAVE PENCILED IN -5
TO 0 DEGREES FOR MANY BY SUNDAY MORNING. VERY POSSIBLE THAT
TEMPERATURES MAY BOTTOM OUT EVEN LOWER AND WILL CONTINUE TO MONITOR
OVER THE NEXT SEVERAL DAYS. THESE TEMPERATURES WITH EXPECTED WINDS
WOULD LIKELY SUGGEST WIND CHILL VALUES AT -20 TO -10F...AND AN
ADVISORY MAY NEED TO BE CONSIDERED BY THE WEEKEND.

THE HIGH WILL SWING THROUGH THE REGION FOR SUNDAY...BEFORE YET
ANOTHER CLIPPER-LIKE SYSTEM DROPS OUT OF THE NORTHERN PLAINS DURING
THE EARLY PART OF THE WORKWEEK. MODELS WAFFLING ON TIMING OF THIS
FEATURE...SO WILL ROLL WITH A LOW CHANCE SNOW FOR BOTH MONDAY AND
TUESDAY AT THIS TIME. CERTAINLY COULD BE AN ADDITION TO THE SNOWPACK
ALREADY LAID DOWN BY THE UPCOMING STORM...AND WILL EMPLOY MORE
DETAIL OVER THE NEXT SEVERAL DAYS AS EXTENDED MODELS COME INTO
ALIGNMENT. FOR TEMPERATURES...HAVE UNDERCUT MOS GUIDANCE THROUGH THE
PERIOD. ALLOW FOR ONLY A SLOW WARMUP FOR MONDAY AND TUESDAY...WITH
SOUTHERN FORECAST AREA APPROACHING THE FREEZING MARK FOR HIGHS.


&&

[Dave]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
305 PM EST TUE JAN 5 2010

.SHORT TERM (TONIGHT AND WEDNESDAY)...

WE ARE FOCUSING ON THE LATE WED NIGHT/THU SNOW EVENT...WILL MAKE
THIS BRIEF FOR TNGT/WED.

UPR LEVEL FLOW WILL TRANSITION FROM NNW TO ZONAL THRU THE PERIOD AS
SOME FLAT RIDGING DEVELOPS BY LATE WED AHEAD OF UPR LO DROPPING SEWD
OVER THE NRN PLAINS. MOISTURE FETCH OFF LAKE MI WILL WEAKEN TNGT AND
SHIFT SLOWLY EASTWARD WHILE WRN MS VLY SFC RIDGE MOVES TO THE ERM MS
VLY BY 12Z WED AND TO THE TN/LWR OH VLYS BY THE END OF THIS PERIOD.

RESULTANT WX: LOW CLOUDS AND SCT FLURRIES WILL BE CONFINED MAINLY TO
OUR ERN SECTIONS TNGT WITH A GOOD DEAL OF SUNSHINE OVER ALL OUR FA
BY MIDDAY WED. WITH A GRADUAL AND MINOR BACK IN THE WINDS...WE
SHOULD SEE WED TEMPS A BIT WARMER (25-30) AFTER ANOTHER COLD NIGHT
TNGT...MAINLY IN THE TEENS.

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

...THIS SEASON`S FIRST SIGNIFICANT SNOW EXPECTED DURING THE MORNING
HOURS THURSDAY...

A COMPACT 500MB TROUGH WILL DIG TOWARDS THE SOUTHEAST ACROSS THE
PLAINS LATE WEDNESDAY AND THEN TRACK EASTWARD ACROSS SOUTHERN OHIO
BY EARLY FRIDAY. ASSOCIATED WITH THIS...THE NOSE OF A STRENGTHENING
JET WILL PUNCH EASTWARD ACROSS THE TENNESSEE VALLEY EARLY THURSDAY.

SNOW WILL LIKELY BEGIN DURING THE EARLY MORNING HOURS THURSDAY WEST
OF INTERSTATE 65...SPREADING INTO THE BLUEGRASS AND LAKE CUMBERLAND
AREAS SHORTLY AFTER DAWN.

FORECAST SOUNDINGS INDICATE THAT PRECIPITATION WILL STAY AS ALL
SNOW...DESPITE THE EXPECTED TRACK OF A WEAK SURFACE LOW NORTH OF THE
OHIO RIVER. EVEN IN SPITE OF WEAK WARM AIR ADVECTION...PRECEDENT
COLD CONDITIONS WILL ENSURE THE ENTIRE ATMOSPHERIC SOUNDING STAYS
BELOW ZERO.

MOST OF THE INDIVIDUAL ENSEMBLE MEMBERS OF BOTH THE NAM AND THE GFS
FORECAST LIQUID QPF BETWEEN .1 AND .3 INCHES. WITH THE EXPECTED
RELATIVELY DRY NATURE OF THIS SNOW...SNOW TO LIQUID RATIOS OF JUST
OVER 15 TO 1 WOULD CORRESPOND TO 3 TO 5 INCHES ACROSS SOUTHERN
INDIANA AND NORTH CENTRAL KENTUCKY.

BOTH THE NAM AND THE GFS HINT AT DRIER AIR AT 700MB QUICKLY MOVING
EAST ACROSS SOUTHERN KENTUCKY THURSDAY AFTERNOON SOUTH OF THE TRACK
OF THE 700MB LOW ACROSS SOUTHERN INDIANA. THUS SNOW MAY CUT OFF
MORE QUICKLY ACROSS OUR SOUTHERN TIER OF COUNTIES...LIMITING
SNOWFALL AMOUNTS TO PERHAPS 2 TO 4 INCHES.

ALONG WITH THE EXPECTED SNOWFALL...ARCTIC AIR WILL ARRIVE DURING
THE LATE AFTERNOON HOURS THURSDAY. NORTHWEST WINDS WILL INCREASE TO
10 TO 15 MPH AND WILL BRING VERY COLD WIND CHILL VALUES AS WELL AS
SOME BLOWING SNOW.

EXPECT FLURRIES OR EVEN LIGHT SNOW TO CONTINUE THURSDAY NIGHT AND EVEN
THROUGH MUCH OF FRIDAY...ESPECIALLY ACROSS SOUTHERN INDIANA...AS AN
ELONGATED 500MB TROUGH IS FORECAST TO LINGER NORTH OF THE OHIO RIVER
DURING THIS TIME.

EXPANSIVE ARCTIC HIGH PRESSURE WILL DROP SOUTH ACROSS MISSOURI
SATURDAY AND MOVE OVER THE TENNESSEE VALLEY LATE SUNDAY. EXPECT
HIGHS TO STRUGGLE TO ESCAPE THE TEENS FRIDAY AND SATURDAY
AFTERNOONS...WITH OVERNIGHT LOWS DROPPING INTO THE UPPER SINGLE
DIGITS. DESPITE AN EXPECTED SNOW COVER...CLOUDS AND NORTHWEST WINDS
MAY LIMIT JUST HOW COLD EARLY SATURDAY LOWS MAY BECOME.

SKIES WILL BEGIN TO CLEAR SATURDAY NIGHT. MOSTLY CLEAR SKIES WILL
CONTINUE THROUGH MONDAY...WITH HIGH TEMPERATURES SLOWLY MODERATING
INTO THE MID 30S BY MONDAY.

&&

[Dave]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
444 PM EST TUE JAN 5 2010

.SYNOPSIS...
-- Changed Discussion --HIGH PRESSURE WILL MOVE INTO THE AREA FOR WEDNESDAY ALLOWING FOR A
BRIEF DRY PERIOD. AN AREA OF LOW PRESSURE WILL MOVE FROM SOUTHERN
ILLINOIS INTO NORTHWEST OHIO FOR THURSDAY ALLOWING FOR
ACCUMULATING SNOWFALL ACROSS THE AREA. COLDER AIR WILL THEN MOVE
INTO THE REGION FOR THE WEEKEND.-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE OVERNIGHT HOURS
ACROSS THE FA AREA. WENT SLIGHTLY COOLER THAN GUIDANCE WITH
TEMPERATURES BASED ON CURRENT TEMPERATURE TRENDS. WITH LACK OF
MOISTURE EXPECT SNOWFALL AMOUNTS OVERNIGHT TO BE RELATIVELY LIGHT
WITH ACCUMULATIONS GENERALLY LESS THAN A HALF INCH. SOME ISOLATED
FREEZING DRIZZLE IS POSSIBLE DURING THE EVENING HOURS HOWEVER DO
NOT EXPECT THIS TO BE WIDESPREAD OR CONTINUE VERY LONG INTO THE
EVENING HOURS. WILL KEEP AN EYE ON THIS HOWEVER AND CONTINUE TO
MONITOR.-- End Changed Discussion --

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
-- Changed Discussion --HIGH PRESSURE WILL MOVE IN BRIEFLY FOR WEDNESDAY BRINGING DRY
CONDITIONS TO THE AREA FOR THE AFTERNOON BEFORE THE NEXT STORM
SYSTEM BEINGS TO IMPACT THE AREA. FORECAST FOCUS WILL BE ON STORM
SYSTEM MOVING THROUGH ON THURSDAY. MODELS ARE IN GENERAL AGREEMENT
WITH GFS BEING THE OUTLIER. WENT WITH A ECMWF AND GEM BLEND. ECMWF
AND GEM BRING SURFACE LOW PRESSURE FROM SOUTHERN ILLINOIS INTO NW
OHIO. THE ECMWF IS SLOWER AND THE GEM IS FASTER WITH THIS SYSTEM.
WENT WITH A BLEND...WITH A SLIGHT BIAS TOWARDS THE GEM. THE NAM IS
SIMILAR TO THE ECMWF AND THE GEM HOWEVER IT TAKES A MORE SOUTHERLY
TRACK AFTER 18Z. THE GFS WOULD BRING THE MOST SNOWFALL TO THE AREA
HOWEVER THIS IS THE OUTLIER WITH THE LOW MOVING ACROSS SOUTHERN
ILLINOIS INTO NORTHERN KENTUCKY AND INTO WV. WENT WITH A WINTER
STORM WATCH OVER SW PORTIONS OF FA WHERE CRITERIA FOR A WINTER
STORM WARNING IS 4 INCHES. BELIEVE THAT THERE WILL BE WIDESPREAD 2
TO 3 INCHES ACROSS THIS AREA WITH SOME LOCATIONS RECEIVING UPWARDS
OF 4 INCHES. AFTER COLLABORATION WITH NEIGHBORS DECIDED TO GO WITH
A WATCH FOR THIS AREA. EXPECT STORM SYSTEM TO WEAKEN SLIGHTLY AS
IT MOVES INTO THE EASTERN FA AND THEREFORE HAVE HELD OFF ON ANY
WATCH MENTION AT THIS POINT. WHAT WILL BE OF IMPORTANCE WITH THIS
SYSTEM WILL BE THE SNOW TO LIQUID RATIO. WITH COOLER AIR IN PLACE
EXPECT HIGHER RATIOS AND THEREFORE HIGHER SNOWFALL VALUES WITH
LESS LIQUID EQUIVALENT. WHAT IS WORKING AGAINST THIS SYSTEM IS IF
IT MOVES FASTER AND WEAKENS FASTER THAN CURRENT THINKING.
ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA AND WILL BE GREATEST
DURING THE DAYTIME HOURS ON THURSDAY. THIS IS ALSO THE TIMEFRAME THAT THE
GREATEST SNOWFALL ACCUMULATION IS EXPECTED. SNOWFALL WILL BEGIN TO
TAPER DOWN DURING THE OVERNIGHT HOURS THURSDAY NIGHT INTO FRIDAY
MORNING WITH ONLY LIGHT ACCUMULATIONS EXPECTED DURING THE
OVERNIGHT HOURS. WINDS WILL PICK UP THURSDAY NIGHT AND THEREFORE
SOME BLOWING SNOW WILL ALSO BE AN ISSUE.-- End Changed Discussion --

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --WILL START THE EXTENDED PERIOD WITH THE MAIN AREA OF LIFT HEADING
OFF TO THE EAST. IN ITS WAKE...MODELS ARE IN AGREEMENT WITH LAKE
EFFECT HEADING SOUTH-SOUTHEAST INTO THE CWA. DO NOT EXPECT STEADY
SNOWFALLS THIS FAR SOUTH BUT THERE WILL BE ENOUGH FOR ADDITIONAL
LIGHT ACCUMULATIONS. MODELS SHOW THIS PRETTY WELL-DEFINED. EVEN THE
GFS AND ECMWF SHOW A DEFINED SPLIT ACROSS OUR CWA...IN BETWEEN THE
MICHIGAN AND HURON-ERIE BANDS.

SNOW SHOWERS WILL TAPER OFF BY SATURDAY MORNING AND
AFTERNOON...LEAVING CLOUDY SKIES AND UNSEASONABLY COLD TEMPERATURES.
HAVE GENERALLY UNDERCUT GUIDANCE THROUGH SUNDAY AND SUNDAY NIGHT.
CURRENT FORECAST HAS THE COLDEST CONDITIONS IN THE GRIDS FOR LOWS ON
SATURDAY NIGHT...WITH SINGLE DIGITS FOR THE ENTIRE CWA.

A MODERATING TREND WILL BEGIN ON MONDAY...BUT THE EXTENDED PERIOD OF
TEMPERATURES NEVER RISING ABOVE FREEZING LOOKS TO CONTINUE THROUGH
TUESDAY. ALTHOUGH HIGHS MAY NEAR OR BRIEFLY HIT THE FREEZING MARK
NEAR THE OHIO RIVER ON TUESDAY...IT LOOKS LIKE IT WILL BE BEYOND THE
SCOPE OF THE 7-DAY FORECAST THAT THE WHOLE CWA COMES OUT FROM UNDER
THE COLD.

SOME HINTS IN THE MODELS OF A SYSTEM PUSHING INTO THE REGION BY
MONDAY OR MONDAY NIGHT...MAINLY ACROSS THE NORTH. THE ECMWF WAS
LEADING THE WAY WITH THIS FEATURE...WITH SOME SUPPORT FROM SOME GFS
ENSEMBLE MEMBERS...BUT THIS HAS BACKED OFF SLIGHTLY. WILL KEEP NO
MORE THAN A BRIEF 20-POP IN THE GRIDS FOR NOW. WENT CLOSE TO
GUIDANCE FOR TEMPERATURES MONDAY AND TUESDAY.-- End Changed Discussion --

&&

[srainhoutx]

Good Luck David. Crazy weather we have from the Rockies E.

[Dave]

Any qualified snow plow drivers out there? Looks like I just got tossed into that job for thursday night unless the guy who I'm replacing gets well...fast...great time for the flu.

[Dave]

Anyone south of me (southeastern Indiana) can have this forecast if you like snow..I don't nor do I like...

859 PM EST TUE JAN 5 2010

...WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH THURSDAY EVENING...

A WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY MORNING
THROUGH THURSDAY EVENING.

SNOW WILL BEGIN ACROSS THE TRI-STATE AREA THURSDAY MORNING AND
WILL CONTINUE INTO THE EVENING HOURS. 3 TO AS MUCH AS 4 INCHES OF
SNOW WILL BE POSSIBLE. SOME DRIFTING OF SNOW CAN BE EXPECTED
THURSDAY NIGHT INTO FRIDAY AS WINDS INCREASE.

[RL3AO]

January Update from Minnesota. Its cold.

[tolakram]

Local Cincy forecasters generally predicting 3 to 5 for the metro area, more to the west, less to the east. We'll see.

[Dave]

Local Cincy forecasters generally predicting 3 to 5 for the metro area, more to the west, less to the east. We'll see.

Yeah I know I'm in the west side bout 35 miles west of the city. I'll let you know if I need ky snowplows over here. Everything is ready to go, all roads pretreated, salt & plows on standby, and I hope it fizzles.

[isobar]

From the last forecast discussion at HPC:

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
420 PM EST WED JAN 06 2010

VALID 00Z THU JAN 07 2010 - 00Z SUN JAN 10 2010


DAY 1...

MIDWEST...
ALBERTA CLIPPER AND ASSOCIATED MID-LEVEL MOISTURE ADVECTION MOVES
ESEWD FROM THE DAKOTAS TO THE SRN END OF LAKE MICHIGAN BY THURSDAY
AFTERNOON. H7 LOW TRACK AND DEFORMATION SHIELD PRECIPITATION WILL
BE MOVING THROUGH AN ATMOSPHERE WHERE OPTIMUM FOR DENDRITIC GROWTH
IS EXPECTED. SNOW TO LIQUID RATIOS NEARING 20:1...HPC PRELIM DAY 1
QPFS...AND THE 12Z GFS/NAM THERMAL BLEND WARRANT A WIDESPREAD AREA
OF 4+ INCHES ALONG THE NORTHERN QUADRANT OF THE CLIPPER WHERE THE
BEST MID-LEVEL SHEAR/DEFORMATION WILL BE TAKING PLACE. MODELS WERE
GENERALLY TOO LOW WITH THEIR SLR FORECASTS...WITH THE MANUAL
GRAPHICS EXPANDING THE AREA OF 2-4 INCHES ALONG THE ARCTIC
BOUNDARY...BASED ON THE HPC QPF CONSENSUS FOR 0.25 LIQUID
EQUIVALENT AND STORM HISTORY ACROSS A LARGE PORTION OF THE
MIDWEST. ADDITIONAL LAKE-EFFECT ACCUMULATIONS ARE POSSIBLE ACROSS
NERN IL/SERN WI BEHIND THE CLIPPER.

[Dave]

3.0" of snow at 1:10 pm at my location in Milan and still snowing. From the reports coming in the average across southern Indiana is 3.0 and central 3 - 4" reports so far. Back edge of the snow is in a line approaching west side of Indianapolis south to Bloomington IN. Another few hours here and should wrap it up...then we freeze.

[Dave]

Ripley county Indiana (my county) has been put under a level one snow emergency..only essential travel is premitted + all emergency services & highway depts. Between 3 & 4" on the ground now. Winter weather advisory still in effect until 6 am friday morning.

[vbhoutex]

Ripley county Indiana (my county) has been put under a level one snow emergency..only essential travel is premitted + all emergency services & highway depts. Between 3 & 4" on the ground now. Winter weather advisory still in effect until 6 am friday morning.

Maybe this is a stupid question, but why the snow emergency? Is a lot more snow expected or is there blowing snow or what? It just seems to this Southern boy that your area wouldn't declare a snow emergency for that small of an amount of snow. Am I way off base in my thinking or what am I missing?

[Siberian Express]

Ripley county Indiana (my county) has been put under a level one snow emergency..only essential travel is premitted + all emergency services & highway depts. Between 3 & 4" on the ground now. Winter weather advisory still in effect until 6 am friday morning.

Maybe this is a stupid question, but why the snow emergency? Is a lot more snow expected or is there blowing snow or what? It just seems to this Southern boy that your area wouldn't declare a snow emergency for that small of an amount of snow. Am I way off base in my thinking or what am I missing?

That's what I was thinking to. We get WX advisory's all the time but never road closures with them. Seems rather draconian. In extreme cases, like last night and today, certain State Highway Routes and Interstates are closed.

For that, mostly in the western and we have actual gates with flashing lights (like a rail road crossing) that that MN DOT close when necessary. Other roads where there are no gates, they barricade with those Road Barricades you see during road construction. It's a $1,000 fine and you pay for your rescue if you violate the closure.

[Siberian Express]

Ripley county Indiana (my county) has been put under a level one snow emergency..only essential travel is premitted + all emergency services & highway depts. Between 3 & 4" on the ground now. Winter weather advisory still in effect until 6 am friday morning.

Maybe this is a stupid question, but why the snow emergency? Is a lot more snow expected or is there blowing snow or what? It just seems to this Southern boy that your area wouldn't declare a snow emergency for that small of an amount of snow. Am I way off base in my thinking or what am I missing?

That's what I was thinking to. We get WX advisory's all the time but never road closures with them. Seems rather draconian. In extreme cases, like last night and today, certain State Highway Routes and Interstates are closed.

For that, mostly in the south and western part of the state we have actual gates with flashing lights (like a rail road crossing) that that MN DOT close when necessary. Other roads where there are no gates, they barricade with those Road Barricades you see during road construction. It's a $1,000 fine and you pay for your rescue if you violate the closure.

[Siberian Express]

It's a long way out (and it's the GFS) but the GFS is showing an interesting pattern in a couple of weeks.

[RL3AO]

Look at this sounding from the Twin Cities yesterday evening.

28 at the surface and about 57 at 4600 feet.