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LES Event NE IL/N IN/SW Lower MI

tornadotony

By tornadotony,
in Lakes/Ohio Valley

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beavis1729

beavis1729

Posted
Posted

Looks like Alek is getting destroyed now...and ORD is about to get SN or +SN shortly. Could be interesting in far NE IL for a couple hours.

Meanwhile, the Northern IN WFO discussion is rather ominous:

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE NORTHERN INDIANA

303 PM EST SAT DEC 4 2010

.SHORT TERM...

...EPIC LAKE EFFECT SNOWSTORM TO TAKE SHAPE THIS PD...

VIGOROUS SW TROUGH DROPPING THROUGH IL EARLY THIS AFTN WAS INDEED

SLW TO LOSE FOCUS W/NARROW HEAVY SNOWBAND OBSVD FALLING FM NE IA

THROUGH CNTRL IL AND INTO CNTRL IN. LL DRY ENTRAINMENT RIGHT OF VORT

TRACK LED TO CONSIDERABLE SUBLIMATION OF SNOW FLAKES AS WITNESSED

HERE AT THE OFFICE AND MINIMIZED SNOW ACCUMS W/HIGHEST REPORT OR 2

INCHES IN CASS COUNTY. SYS IN THE PROCESS OF ACCELERATING THROUGH

BASE OF DEEPENING LW TROUGH OVR NEW ENGLAND THIS WEEKEND AND WILL

BRING QUITE A STORM TO THE ERN ST LAW VALLEY.

TREMENDOUS DOWNSTREAM BLOCKING WILL PROVE PIVOTAL W/DEEP CUTOFF

CYCLONE SLOW TO RETROGRADE NWWD INTO MID WEEK. THUS WWD DEEP

MERIDIONAL FLW DOWN LONG AXIS OF LK MI COMBINED W/PRECONDITIONED

PARCELS OFF LK SP LOOK TO SPELL A PROLONGED PD OF LK EFFECT SNOWFALL.

AS ALWAYS...DEVIL IS IN THE DETAILS PARTICULARLY W/CONTRASTING

SOLUTIONS OF NAM AND 12KM WRF. INTERESTINGLY WRF SOLUTION AT FACE

VALUE ALIGNS QUITE WELL W/JAN 1ST/5TH 2010 ANALOGS W/INITIAL INTENSE

SINGLE BAND DVLPMNT THIS EVENING AND ALREADY WELL UNDERWAY UPSTREAM

PER REGIONAL RADAR COMPOSITES AND THEN TRANSITIONING TO DUAL DIPOLE

VORTEX SEEN IN MANY PAST LK EVENTS. HWVR ALTHOUGH WRF HAS SHOWN

CONSIDERABLE CONSISTENCY LAST TWO DAYS...PREFERRED DIPOLE HAS

WAFFLED. CLIMO FVRS ERN BAND GIVEN INTENSITY OF THERMAL TROUGH IN

FACE OF DEEP SHORE PARALLEL FLW HWVR INLAND PLACEMENT STILL QUITE

UNCERTAIN AND LIKELY FURTHER MODULATED BY DEGREE OF CAA THAT WRAPS

SWD OUT OF SRN CANADA WHICH MAY HAVE YET TO BE FULLY

CAPTURED/INITIALIZED. THUS ANY CHGS THROUGH MON NIGHT WERE

INCREMENTAL IN NATURE W/NEWER GUIDANCE BLENDED IN WHERE DEEMED

APPROPRIATE. LARGEST CHG WAS TO THIS EVENING TO DELAY ERN

TRANSLATION OF SINGLE BAND GIVEN SLWD BACKING AND ADDED DETAILS IN

DERIVED POP/QPF GRIDS THROUGH MON NIGHT.

&&

.LONG TERM...

TUESDAY THROUGH SATURDAY

BEGINNING OF THE PERIOD SHOULD SEE CONTINUATION OF LAKE EFFECT SNOW

SHOWERS ALTHOUGH INTENSITY SHOULD BEGIN TO WANE BY TUESDAY AS UPPER

HEIGHTS SLOWLY BUILD AND INVERSION HEIGHTS BEGIN TO FALL. SOME

ADDITIONAL LIGHT ACCUMULATIONS WILL BE POSSIBLE BUT STILL SOME

UNCERTAINTY DURING THIS PERIOD IN REGARDS TO LAKE EFFECT POTENTIAL

DUE TO REINFORCING UPPER TROUGH EXPECTED TO DIG DOWN WEST SIDE OF

UPPER LEVEL TROUGH INTO THE GREAT LAKES REGION. MODELS ALL AGREEING

ON REINFORCING TROUGH...BUT SOME SUBSTANTIAL TIMING DIFFERENCES

NOTED WITH NAM BEING A FAST AND WESTWARD OUTLIER DIGGING THIS TROUGH

INTO THE WESTERN GREAT LAKES. NAM/GFS BUFFER SOUNDINGS DO INDICATE

LAKE INDUCED EQUILIBRIUM LEVELS WITH A SECONDARY PEAK AS THIS

SECONDARY LOW LEVEL THERMAL TROUGH DROPS DOWN. HAVE GENERALLY SIDED

WITH GEFS/SREF SUPPORTED GFS SOLUTION REGARDING TIMING THIS TROUGH

MORE IN THE TUESDAY NIGHT PERIOD...AND HAVE THUS KEPT AT LEAST

CHANCE MENTION OF LAKE EFFECT SNOW SHOWERS THROUGH EARLY THURSDAY

MORNING WHEN LOW LEVEL RIDGE AXIS IS EXPECTED TO APPROACH. PASSAGE

OF THE RIDGE AXIS THURSDAY WILL ALLOW FOR ONSET OF LOW LEVEL WARM

ADVECTION...ALTHOUGH WITH RECENT SNOW AND FORECASTED EARLY WEEK

SNOWFALL...THIS WARM ADVECTION WILL LIKELY NOT HAVE MUCH OF AN

IMPACT ON THE SFC. HAVE CONTINUED TO SLIGHTLY UNDERCUT MEX GUIDANCE

DURING THIS PERIOD WITH HIGHS GENERALLY IN THE MID TO UPPER

20S...AND POSSIBLY MAY NEED TO NUDGE DOWN FURTHER ESPECIALLY FOR

TUES/WED.

And, here is the LES warning for SW lower MI:

INCLUDING THE CITIES OF...MICHIGAN CITY...LA PORTE...NILES...

BENTON HARBOR...ST. JOSEPH...BUCHANAN

119 PM EST SAT DEC 4 2010 /1219 PM CST SAT DEC 4 2010/

...LAKE EFFECT SNOW WARNING REMAINS IN EFFECT FROM 9 PM EST /8 PM

CST/ THIS EVENING TO 6 AM EST /5 AM CST/ TUESDAY...

A LAKE EFFECT SNOW WARNING REMAINS IN EFFECT FROM 9 PM EST /8 PM

CST/ THIS EVENING TO 6 AM EST /5 AM CST/ TUESDAY.

* TIMING...LAKE EFFECT SNOW WILL COMMENCE TONIGHT...FIRST IN

WESTERN LAPORTE COUNTY. AS WINDS SHIFT TO THE NORTHWEST LATE

TONIGHT INTO SUNDAY...LAKE EFFECT SNOW SHOWERS WILL MOVE

FURTHER EAST AND PERSIST. SNOWFALL RATES WILL BE HEAVY AT

TIMES. LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO MONDAY

NIGHT.

* SNOW ACCUMULATIONS...TOTALS OF 10 TO 20 INCHES BY DAYBREAK

TUESDAY...LOCALLY HIGHER AMOUNTS UPWARDS OF 2 FEET POSSIBLE.

* OTHER IMPACTS...VISIBILITIES WILL BE HIGHLY VARIABLE AND NEAR

ZERO AT TIMES WITH INTENSE SNOWFALL IN NARROW BANDS. UNTREATED

ROADS WILL BECOME SNOW COVERED AND SLIPPERY. TRAVEL ON

AFFECTED PORTIONS OF INTERSTATES 80 AND 94 WILL BECOME

TREACHEROUS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A LAKE EFFECT SNOW WARNING MEANS SIGNIFICANT AMOUNTS OF LAKE

EFFECT SNOW ARE FORECAST THAT WILL MAKE TRAVEL VERY HAZARDOUS OR

IMPOSSIBLE. LAKE EFFECT SNOW SHOWERS TYPICALLY ALIGN THEMSELVES

IN BANDS AND WILL LIKELY BE INTENSE ENOUGH TO DROP 1 TO 3 INCHES

OF SNOW PER HOUR FOR SEVERAL HOURS. VISIBILITIES VARY GREATLY AND

CAN DROP TO ZERO WITHIN MINUTES. TRAVEL IS STRONGLY DISCOURAGED.

COMMERCE COULD BE SEVERELY IMPACTED. IF YOU MUST TRAVEL...KEEP AN

EXTRA FLASHLIGHT...FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN

EMERGENCY.

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huronsquall

huronsquall

Posted
Posted

SW Ontario also looks to get into the action as well. It is starting to fire up to the southeast of Lake Huron too. Watches are up for London and areas to the south. Here's hoping Perth and Wellington counties get into some action too. The flow will be a bit too northerly for me maybe - at least reading the watches up from Environment Canada. But they are calling for an epic event for sure as they state "Some highways may become virtually impassable over some districts to the southeast of Lake Huron due to the longevity of the falling and drifting snow with excessive snow depths." We'll see what happens over the next few days.

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IWXwx

IWXwx

Posted
Posted

For some reason, I'm thinking I have seen Ft. Wayne with an ADV once but I don't think it verified.

I'm thinking that we have had a Lake Effect Advisory in Huntington County, Just SW of Ft. Wayne, that did not verify. I can't remember the date though. I do remember one event that verified as an advisory level LES, but wasn't issued this far SE. I can't remember the date of that either.

I am now keeping better snow records, more than just amounts and depths.

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Indystorm

Indystorm

Posted
Posted

Just got back to Elkhart from a chartered bus trip to Woodfield Mall in Schaumburg for the day. This morning the toll road was just wet, but the snow looked very beautiful on the trees in the metro Chi town area. Coming back here this evening we had very little precip....radar must be showing virga with the column not fully saturated as yet in many areas. We left the mall at 4:45 CST. Only a very slight remains of dusting here at Elkhart at the present but if this LES develops as anticipated that will soon change in the next couple days. The O Hare report listed above surprises me. Of course when you're inside a mall you really don't see things and this can be highly localized. Would anticipate convective snow bursts with this intense a scenario shaping up at present.

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janetjanet998

janetjanet998

Posted
Posted

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE NORTHERN INDIANA

555 AM EST SUN DEC 5 2010

SHORT TERM

..MAJOR LES EVENT UNDERWAY

WRFARW SUPERIOR HANDLING VS NAM12 WRT ANTICIPATED AND RAPID

ONSLAUGHT OF MAJOR LAKE AXIS BAND NOW UNDERWAY WITH VSBYS AOB

1/2SM IN UPWARDS OF 30-40 DBZ IN CELLULAR RETURNS WITH TOPS

REACHING 13-14 KFT. NEAR ON ORDER OF MAGNITUDE HIR 1000-900 MB

CONVERGENCE IN TIGHT THERMAL BAND AMID HI LVL AMBIENT RH THROUGH

DEEP MIXED LYR WRN/SWRN GRLTKS. GAVE NOD TO WRF AND RADAR TRENDS

IN NEAR TERM AND CONT TO RIDE ONGOING LONG DURATION HEADLINES/AMOUNTS

WITH HIR CONF THAN 24 HRS AGO GIVEN SUSTAINED STRONG SIGNALS.

LITTLE IN CLOUD SHEAR OF NOTE IN UNIFORM GRDL BACKING CBL FLOW TO

330/25KT FETCH FOR SVRL HRS MIDDAY. POTNL LULL THEN LATE SUNDAY

AFTN INTO ERLY TONIGHT AS FLOW BACKS AND BECOMES DISTURBED AS

MANITOBA S/WV ENERGY SUCKED SSWD INTO WRN GRTLKS TONIGHT AS SFC

LOW NOW OFF CA COAST BOMBS AND IS DRAWN NWD INTO COMPLEX/BLOCKED

FUJIWARA ACRS UPSTATE NY/NEW ENGLAND BY MIDDAY MON. SUSPECT WITH

BACKING FLOW AND INCRSD MOIST BL SHEAR THAT BANDS TO SEGUAY INTO

MULTIPLE SOMEWHAT WEAKER BANDS AND ALTHOUGH 8H/LK DELTA T STILL

NEAR 20C...SUPPRESSED EQL BACK DOWN TO 6-7KFT AND DGZ THICKNESS

DECRS SUGGESTS PD OF LESSER ACCUM RATES DURING THIS TIMEFRAME.

LCLWRF SUGGESTS THREE PRIMARY BANDS TO FORM...WITH ONLY KLWA/KAZO

INTO NRN CWA BAND ONLY ONE TO MAINTAIN LK SUPR CONDITIONING. OF

CONCERN IN IS HEADLINE FOR STARKE COUNTY THAT DEPENDING UPON SRN

BAND STRENGTH AND IF PLACEMNT RMNS IN OR JUST N OF NORTHEAST

CORNER OF CO FOR PSBL DOWNGRADE TO ADV OR EXT/CAN OF CURRENT

WARNING LTR TDY. RATES THEN INCRS IN EARNEST ERLY MONDAY AM

THROUGH LATE MON EVE FOR POOR COMMUTE DAY IN HEADLINED AREA.

SUSTAINED DURATION OF 400-450 J/KG LK INDUCED CAPE...8H/LK DELTA

20C AND TO 7H 24-25C...REMERGED THICK/5KFT DGZ IN COLLOCATED UVM

MAX. PIVOT AXIS AND DURATION TO GIVE NRN BERRIEN/WRN CASS CO BEST

HOPE FOR TWO FEET BY DAYBREAK TUE.

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TugHillMatt

TugHillMatt

Posted
Posted

Although I'm not expected to get the heaviest snows where I'm located, we've started off quite well with this lake effect here. I live about a minute from Lake Michigan...have gotten a couple inches already from heavy bursts of snow. If it continues, I'm pretty sure we'll be upgraded from our advisory for 4 to 8 inches to a warning with more than 8 inches...

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Indystorm

Indystorm

Posted
Posted

Although I'm not expected to get the heaviest snows where I'm located, we've started off quite well with this lake effect here. I live about a minute from Lake Michigan...have gotten a couple inches already from heavy bursts of snow. If it continues, I'm pretty sure we'll be upgraded from our advisory for 4 to 8 inches to a warning with more than 8 inches...

Those multiple bands coming off the length of Lake Michigan with even a Superior connection mean business. They're thinking 1-3 inch rates per hour at times in my region when things get going.

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TugHillMatt

TugHillMatt

Posted
Posted

Those multiple bands coming off the length of Lake Michigan with even a Superior connection mean business. They're thinking 1-3 inch rates per hour at times in my region when things get going.

They sure do! Judging from how they have been dumping on us here....you are going to get some really good snows down there with the extra part of Lake Michigan between you and me. I look forward to your reports!

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janetjanet998

janetjanet998

Posted
Posted

IND

NEAR TERM /REST OF TODAY/

STRONG N/NW LOW LEVEL FLOW HAS ENABLED LAKE EFFECT SNOW BANDS OFF

LAKE MICHIGAN TO DROP SOUTHEAST INTO NORTHEAST PORTIONS OF THE

FORECAST AREA AS OF 14Z. RADAR RETURNS CURRENTLY SUGGEST ENHANCED

SNOWFALL FALLING EAST OF A KOKOMO TO NOBLESVILLE TO GREENFIELD AND

RUSHVILLE LINE AT 15Z WITH POCKETS OF HEAVIER SNOW SHOWERS AND

REDUCED VISIBILITIES. AT THIS POINT IN TIME...TRAJECTORIES WOULD

SUGGEST MOST IF NOT ALL OF THE INDY METRO WILL STAY WEST OF THE

HEAVIER SNOW SHOWERS.

HAVE BUMPED UP POPS SUBSTANTIALLY NORTHEAST OF THE INDY METRO

THROUGH 18Z TO ACCOUNT FOR CURRENT ACTIVITY...WITH POTENTIAL FOR

LIGHT ACCUMULATIONS ON THE ORDER OF A DUSTING TO ONE HALF INCH OF

SNOW. RUC/WRF/HRRR DATA ALL INDICATE FURTHER BACKING OF THE WINDS

THROUGH THE BOUNDARY LAYER AS THE AFTERNOON PROGRESSES...WITH THE

ENHANCED LAKE EFFECT BANDS SHIFTING TO A MORE W/NW DIRECTION OFF

LAKE MICHIGAN. THIS WILL LIKELY TAKE MOST OF THE HEAVIER SNOW

SHOWERS OUT OF THE NORTHEAST FORECAST AREA WITH ONLY RANDOLPH AND

NORTHERN DELAWARE COUNTIES POSSIBLY STILL BEING IMPACTED.

-----------------------------------------

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE NORTHERN INDIANA

1008 AM EST SUN DEC 5 2010

UPDATE

THERMAL TROUGH CONTS TO DEEPEN ACRS THIS MORNING W/DRAMATICALLY MORE

FOCUSED SNOW BANDING CLEARLY EVIDENT PER ECHO EVOLUTION LAST 3 HRS.

CURRENT MEASURED FLW TRAJ AT 330 W/AT LEAST 1 IN/HR RATES OCCURRING

IN 30-35 DBZ CORES AND XPC FURTHER CONSOLIDATION/DIURNAL ENHANCEMENT

TO EXISTING HCRS INTO THIS AFTN BFR FLW BACKS AHD OF WK SW TROUGH

DROPPING OUT OF MN. XPC ERN MOST BAND TO BECOME DOMINANT THIS AFTN

TIED TO UPSTREAM LK SP FETCH AND MAXIMIZED ALG SHORE CVRG W/+SN

RECENTLY NOTED AT KBIV. GOING GRIDS CLOSE YET REFINED THROUGH AFTN

BASED ON CURRENT ANALYSIS. ERN BAND MAY FACILITATE A NEED FOR CAT

UPGRADE ACRS ST JOE MI AND LAGRANGE COUNTIES AND PERHAPS EVEN

FURTHER BUT WILL AWAIT HIRES OUTPUT TO ASSESS THAT NEED. MORE TO

FOLLOW THIS AFTN.

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