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January 31-February 2 Historic Winter Storm part 6


Hoosier

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AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE INDIANAPOLIS IN

354 PM EST SUN JAN 30 2011

UPDATE

THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE

BEEN UPDATED BELOW.

SYNOPSIS

A CRITICAL AND POTENTIALLY DANGEROUS WINTER WEATHER SITUATION IS

SETTING UP FOR CENTRAL INDIANA. A POTENT UPPER LEVEL LOW HAS MOVED

ONSHORE INTO CENTRAL AND NORTHERN CALIFORNIA TODAY...AND THIS WILL

COMBINE WITH ANOTHER WAVE DESCENDING OUT OF CANADA ALONG WITH A

BROAD ARCTIC HIGH TO PRODUCE WHAT MAY BE A LONG AND WIDESPREAD

FREEZING OR FROZEN PRECIPITATION EVENT. THE SURFACE LOW TRACK

REMAINS SOMEWHAT IN QUESTION...WHICH WILL OBVIOUSLY HAVE MAJOR

IMPACT ON THE AXES OF HEAVIEST ICING AND HEAVIEST SNOW. THIS LOW

WILL PASS EAST OF THE AREA IN THE LATTER PORTION OF THE WEEK WHILE

A LARGE AND STRONG ARCTIC HIGH PLUNGES INTO THE CENTRAL U.S.

NEAR TERM /TONIGHT/

FOCUS TONIGHT IS ON TEMPS. MODELS ARE CLOSE AND A BLEND IS USED.

WHILE WE MAY INITIALLY START THE EVENING CLEAR IN THE SOUTHERN

HALF TO TWO THIRDS OF THE FORECAST AREA...THESE CLEAR SKIES HAVE

ALSO CONTRIBUTED TO TEMPERATURES THAT HAVE WILDLY EXCEEDED ALL

GUIDANCE PACKAGES THIS AFTERNOON...TO THE TUNE OF 5 TO 7 DEGREES

IN MANY SPOTS. THUS...HAVE CHOSEN TO BUMP UP EVEN THE WARMER MET

GUIDANCE WHICH YIELDS LOWS RANGING FROM THE UPPER TEENS TO THE MID

TO UPPER 20S ACROSS THE AREA.

SHORT TERM /MONDAY THROUGH WEDNESDAY/

MAJOR WINTER STORM TO IMPACT THE AREA BEGINNING LATE MONDAY AND

CONTINUING THROUGH WEDNESDAY. NUMEROUS PRECIPITATION TYPES WILL

OCCUR ACROSS CENTRAL INDIANA...AND BOTH SIGNIFICANT SNOWFALL AND

SIGNIFICANT ICE ACCUMULATIONS ARE POSSIBLE.

MODEL GUIDANCE IS IN SOMEWHAT DECENT AGREEMENT...ALL THINGS

CONSIDERED...BUT THIS IS REALLY THE FIRST MODEL RUN IN WHICH THE

LOW HAS MOVED ONSHORE INTO THE UPPER AIR NETWORK...SO UNCERTAINTY

REMAINS REGARDING THE EXACT TRACK OF THE SYSTEM. IN

ADDITION...TRENDS IN RECENT RUNS HAVE BEEN SLOWLY BUT STEADILY

PULLING THE LOW TO THE NORTHWEST...AS IS OFTEN SEEN WITH SUCH

STRONG SYSTEMS...AND THIS COULD HAVE AN ENORMOUS IMPACT ON THE

RESULTANT SNOW AND ICE ACROSS THE AREA. WHEREAS CURRENT THINKING

IS THAT THE HEAVY SNOW AXIS WILL BRUSH NORTHWESTERN PORTIONS OF

CENTRAL INDIANA...WITH THE MAJOR ICING AXIS ROUGHLY ALONG THE

INTERSTATE 70 CORRIDOR...CONTINUED NORTHWEST TRENDS COULD SHIFT

ALL THESE NORTHWEST AS WELL.

SYSTEM IS STRONGLY FORCED REALLY NO MATTER HOW ONE CHOOSES TO

QUANTIFY IT. MODELS CONTINUE TO ADVERTISE A COUPLED UPPER LEVEL

JET STRUCTURE...ALONG WITH AN INCREDIBLY STRONG SOUTHERLY LOW

LEVEL JET AHEAD OF THE SYSTEM...60 TO 80KTS AT 850 MB. STRONG

FRONTOGENETICAL FORCING IS NOTED...ESPECIALLY TUESDAY AND TUESDAY

NIGHT. STRONG Q VECTOR CONVERGENCE ALOFT IS ALSO NOTED...AGAIN

ESPECIALLY TUESDAY AND TUESDAY NIGHT.

FORECAST SOUNDINGS CONTINUE TO DISPLAY CLASSIC FREEZING RAIN

PROFILES TOMORROW NIGHT AND MUCH OF TUESDAY...ALTHOUGH WITH VERY

LOW LOWER LEVEL WETBULB TEMPS MAY SEE THINGS BRIEFLY START LATE

TOMORROW AFTERNOON INTO THE EVENING AS SNOW BEFORE RAPIDLY

TRANSITIONING TO FREEZING RAIN OR A MIX WITH SLEET.

AS WARM ADVECTION INCREASES AHEAD OF THE LOW INTO TUESDAY AND

TUESDAY NIGHT...FREEZING RAIN OR MIXED PRECIP ZONE WILL PUSH EVEN

FURTHER NORTH...PERHAPS ALLOWING A TRANSITION TO JUST RAIN OVER

SOUTHERN TIER OF CENTRAL INDIANA. AS LOW PASSES LATE TUESDAY NIGHT

INTO WEDNESDAY...STRONG COLD ADVECTION WILL ALLOW A TRANSITION TO

ALL SNOW. IN ADDITION...VERY STRONG SURFACE PRESSURE GRADIENT WILL

PRODUCE GUSTY WINDS...PERHAPS AS HIGH AS 35 TO 40 MPH. THIS

COUPLED WITH SIGNIFICANT SNOW AND ICE MAY CAUSE DAMAGE TO

TREES...POWER LINES...AND PERHAPS SOME STRUCTURES...EVEN AFTER THE

HEAVIEST PRECIPITATION HAS ENDED...AND MAY COMPLICATE RECOVERY

EFFORTS AFTER THE FACT.

FOR TEMPS...STUCK VERY NEAR MODEL SURFACE WETBULB TEMPERATURES AS

WIDESPREAD PRECIPITATION WILL BE ONGOING FOR MUCH OF THE SHORT

TERM. INTENSE THERMAL GRADIENT ACROSS THE AREA WILL MAKE FOR A

VERY WIDE RANGE OF TEMPERATURES AT TIMES THROUGH THE PERIOD.

CONSENSUS AMONG SURROUNDING OFFICES IS TO CONTINUE WITH

WATCHES...AS TRENDS COULD SIGNIFICANTLY CHANGE WHERE HEAVY SNOW

AND SIGNIFICANT ICE WILL OCCUR...TO ACCOUNT FOR POTENTIAL OF

SIGNIFICANT ICE ON MONDAY NIGHT...WILL PULL START TIME OF WATCH

BACK TO 00Z TUESDAY AND EXPAND TO INCLUDE ALL CENTRAL INDIANA

COUNTIES TO PROVIDE SOME MARGIN FOR UNCERTAINTY.

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Alright, I'm gonna bite after that 12z guidance.

ORD 22-28"

At least two gusts to 50KT (from ASOS/official obs)

At least four gusts to 45KT

Max sustained at 34KT.

Blizz criteria met.

3-5" inital WAA

18-24" from the main storm.

RFD gets 19-25"

At least 1 gust to 50KT

At least 3 gusts to 45KT

Max sustained at 30KT

Blizz criteria met.

Truly almost unbelievable. The fact that a person as gifted/educated with weather as yourself has typed this scenario out is something. Kudos to you. And man I hope like hell something like this goes down. :)

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Well the 18Z NAM is even farther Wtongue.gif So that means it actually took two steps back according to that HPC disco.

Wonder what is up with that? One would think then that the surface features would come west as well? Strange..

Oh well. Cant complain as i know it is a very complex situation for the models to resolve.

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Those of you in the ice area

Generators will run out very fast - gasoline stations could be closed - we ran out of many many gallons of gas - there is only so much you can put in gallon jugs - we could not buy gasoline jugs anywhere for days and days after the event. Batteries gone. No power means no ATM machines. Cash was KING during the ice storm. Most places would not accept anything but cash.

I echo on Beau with this. Fill up your car now. If you go to a College and you are over 200 miles from home, I would go ahead and fill up your car today. My University had to evacuate all the dorms and sent us home because we had no water, no power, no cell phone service. Nearest working gas station was 30 miles to my south and 50 miles to my east. Luckily I had just enough gas to get me to the one to my east. You never know what can go wrong.It's best to prepare now.

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And for those wondering what will happen

http://blog.usawx.co...stern-kentucky/

That is what we went through - my journal at the time.

Wow amazing pictures. Ice storms like that are definitely devastating. Jomo brought up 1997 in Springfield, MO. My sister was down there for that and the epic power loss across the city crippled everything. She had to move to Branson for over a week with her kids/husband because of it.

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Wonder what is up with that? One would think then that the surface features would come west as well? Strange..

Oh well. Cant complain as i know it is a very complex situation for the models to resolve.

Yeah a good question. dtk at NCEP--who works on the GFS data assimilation system--called it the "NAM drift" issue. It is definitely propping its head up here. Those changes in the height field are just not realistic at 48 hours. It very well may tick a tad W--but that type of change either W or E in the overall large scale trough is not something that typically happens.

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10-15" with isolated higher amounts may be a safe forecast for the whole event here. I don't know if I'd feel comfortable going any higher than that 48+hrs out lol.

The public can't see right now, but you would love what is sitting in our extended snow grids. Let's just say it's a 10" range across the CWA and everyone gets double digits for a 3 day total.

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Umm...18z NAM raw data is showing 2.22" liquid at ORD...

MON 7P 31-JAN -5.7 -7.1 1025 88 99 0.01 552 532

TUE 1A 01-FEB -6.4 -7.7 1024 90 90 0.13 552 533

TUE 7A 01-FEB -6.4 -10.1 1025 90 93 0.08 551 532

TUE 1P 01-FEB -4.4 -9.6 1024 88 81 0.04 553 534

TUE 7P 01-FEB -4.5 -10.0 1019 92 98 0.24 550 535

WED 1A 02-FEB -5.3 -9.7 1010 90 98 0.71 543 535

WED 7A 02-FEB -4.8 -13.9 1006 92 93 0.75 532 527

WED 1P 02-FEB -4.8 -14.4 1013 89 88 0.19 532 522

WED 7P 02-FEB -5.1 -14.2 1023 84 84 0.07 539 521

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Yeah a good question. dtk at NCEP--who works on the GFS data assimilation system--called it the "NAM drift" issue. It is definitely propping its head up here. Those changes in the height field are just not realistic at 48 hours. It very well may tick a tad W--but that type of change either W or E in the overall large scale trough is not something that typically happens.

So these heights is causing the storm to track too far west?

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Wow amazing pictures. Ice storms like that are definitely devastating. Jomo brought up 1997 in Springfield, MO. My sister was down there for that and the epic power loss across the city crippled everything. She had to move to Branson for over a week with her kids/husband because of it.

It was in 2007. We actually had two. One in Jan and one in Dec. Both were right along I-44, and this system may be moving towards a solution similar.

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NWS Norman will be issuing a PDS Winter Storm Warning....I didn't know they even existed! :arrowhead:

I'll add the text when it comes out.

I hope that is more of a euphemism than a reality. I think the idea behind a winter storm warning is that it is already particularly dangerous, especially in the OUN area.

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Umm...18z NAM raw data is showing 2.22" liquid at ORD...

MON 7P 31-JAN -5.7 -7.1 1025 88 99 0.01 552 532

TUE 1A 01-FEB -6.4 -7.7 1024 90 90 0.13 552 533

TUE 7A 01-FEB -6.4 -10.1 1025 90 93 0.08 551 532

TUE 1P 01-FEB -4.4 -9.6 1024 88 81 0.04 553 534

TUE 7P 01-FEB -4.5 -10.0 1019 92 98 0.24 550 535

WED 1A 02-FEB -5.3 -9.7 1010 90 98 0.71 543 535

WED 7A 02-FEB -4.8 -13.9 1006 92 93 0.75 532 527

WED 1P 02-FEB -4.8 -14.4 1013 89 88 0.19 532 522

WED 7P 02-FEB -5.1 -14.2 1023 84 84 0.07 539 521

looks like some 2.5 inches amounts for me

waiting for people to post more detailed info

I'll believe it when i see it though

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Timing is definitely changed and the ptype over regions where things are relatively close would be much different.

Hi BI, Congrats on your new job, You will be a gr8 forcaster as you are here! So Im currently thinking some colder air will make it further south to me, making this a more serious icing for us? Thanks

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From OUN:

THIS IS A PARTICULARLY DANGEROUS WINTER STORM SITUATION... WITH THE

POTENTIAL FOR BLIZZARD OR NEAR-BLIZZARD CONDITIONS ALONG WITH

LIFE-THREATENING WIND CHILLS. TRAVEL IS LIKELY TO BECOME EXTREMELY

DIFFICULT IF NOT IMPOSSIBLE BY TUESDAY MORNING. ALL RESIDENTS IN

CENTRAL AND NORTHERN OKLAHOMA ARE URGED TO TAKE THIS DEVELOPING

WINTER STORM SERIOUSLY AND PLAN FOR THE POSSIBILITY OF

SIGNIFICANT DISRUPTIONS BY LATE MONDAY NIGHT AND TUESDAY MORNING.

* A STRONG STORM SYSTEM WILL MOVE FROM SOUTHERN NEVADA INTO THE

FOUR CORNERS REGION BY MIDDAY MONDAY. THIS SYSTEM WILL THEN MOVE

ACROSS THE SOUTHERN PLAINS ON TUESDAY.

* TIMING: RAIN WILL CHANGE QUICKLY TO A MIX OF FREEZING RAIN SLEET

AND SNOW MONDAY EVENING. SNOW MAY BECOME HEAVY AT TIME LATE

MONDAY NIGHT INTO TUESDAY MORNING... ALONG WITH SUBSTANTIAL

BLOWING AND DRIFTING... BEFORE TAPERING OFF TUESDAY AFTERNOON.

* MAIN IMPACT: A CRIPPLING COMBINATION OF SNOW AND BLOWING SNOW

FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING... MAKING TRAVEL

VERY DIFFICULT OR IMPOSSIBLE.

* OTHER IMPACTS: VERY STRONG NORTH WINDS WILL CREATE DANGEROUS

WIND CHILL VALUES LATE MONDAY NIGHT INTO TUESDAY. THE STRONG

WINDS... ALONG WITH EVEN LIGHT ACCUMULATIONS OF ICE OR SNOW ON

EXPOSED SURFACES... ALSO MAY LEAD TO DISRUPTIONS OF COMMERCIAL

POWER. BLOWING SNOW MAY CREATE POOR VISIBILITY AND NEAR-WHITEOUT

CONDITIONS IN SOME AREAS.

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