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January 31-February 2 Historic Winter Storm part 6


Hoosier

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OAX AFD:

AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE OMAHA/VALLEY NE355 AM CST MON JAN 31 2011.DISCUSSION...SYNOPSIS...00Z UPPR AIR ANLYS INDCD THE TWO MAIN SYSTEMS OFINTEREST WERE NOW ONSHORE AND OVER THE WRN US. THE STREAM STREAM LOWLOCATED OVR THE SRN GREAT BASIN ASSOCIATED WITH 100 M H5 HEIGHTFALLS. THE NRN STREAM SYSTEM WAS LOCATED OVR SRN ALBERTA ANDASSOCIATED WITH 60 M H5 HEIGHT FALLS. DOWNSTREAM FM THESYSTEMS...ZONAL FLOW EXTNDD ACRS THE PLAINS. GREATEST H7 THRMLGRADIENT EXTNDD FM SRN MT INTO CNTRL MN. H85 LO WAS LOCATED OVR WYWITH ARCTIC FNT NEWD THRU ND. 09Z SFC ANLYS INDCD LO PRES OVR NRNCO. AN INVERTED TROF WAS DVLPG FM ERN KS INTO WRN IA.FORECAST...DIFFICULT FORECAST THIS MRNG AS WE STILL FEEL THEMODELS STILL DO NOT HAVE A FULL HANDLE ON HOW THE TWO WRN SYSTEMSWILL INTERACT OVER THE NEXT 48 HOURS. LITTLE OVERALL CHANGE IN THEMODELS FM 00Z WITH THE GFS STILL FARTHER S AND FASTER...AND THEEC STILL FARTHER NW AND SLOWER. GIVEN THE SUPPORT FOR THE EC FMTHE NAM/GEM AND ENSEMBLES...WILL CONT LEAN A LITTLE HEAVIER ONTHIS MODEL...BUT A BLEND WAS REALLY USED. STG MID LVL THRMLGRADIENT OVER THE NORTHERN PLAINS WILL DROP SWD TODAY AND INTO THEFA THIS AFTERNOON. AT THE SAME TIME...UPPR LEVEL JET FM THE CNTRLROCKIES INTO THE NRN PLAINS WILL SHIFT EWD LEAVING THE FA IN THERIGHT REAR ENTRANCE REGION OF THIS JET. THUS ON THE SYNOPTICSCALE...THE ATMOSPHERE SHLD FAVOR ASCENT BY THIS AFTERNOON. THISCOUPLED WITH THE STRONG THERMAL GRADIENT WILL LIKELY LEAD TO ANEFFECTIVE FRONTAL CIRCULATION BY LATE THIS AFTERNOON. THUSALTHOUGH WE ARE LIKELY TO SEE A LITTLE LIGHT SNOW THIS MORNING INTHE NW...THIS SHLD INCREASE IN COVERAGE AND INTENSITY THROUGH THEAFTN WITH A NICE LITTLE E-W BAND SETTING UP BY THIS EVENING. UNTILTHEN...WE SHOULD SEE FZDZ FAIRLY WIDESPREAD OVER THE SRN/ERN CWAAS DEEPER LO-LVL MOISTURE /SEEN ON THE KTWX RADAR AT 09Z/ SHIFTSNEWD THRU THE AREA. THUS WL CONT TO MENTION THE FZDZ FOR THE MRNGHOURS ALONG WITH SOME FOG. BEST SNOWFALL RATES ASSOCIATED WITHTHIS INITIAL JET CIRCULATION WILL LIKELY BY FROM AROUND 21-06ZBEFORE THE UPPR LVL JET SHIFTS EWD AND THE FRONTAL CIRCULATIONBREAKS DOWN. THIS IS WHEN WE ARE LIKELY TO SEE OUR GREATESTACCUMULATIONS IN THE NW FA WHERE 2-4 INCHES ARE LIKELY TO FALL. ASINVERTED TROF SHARPENS TODAY...SHLD SEE WINDS INCREASE BEHIND THETROF /OVR NE NEB/ LEADING TO SOME BLOWING AND DRIFTING BY LATETHIS AFTN.A LULL IN THE STEADY SNOW IS THEN EXPECTED FM AROUND 09-15Z ONTUES AS THE JET ASSOCIATED WITH THE SRN STREAM SYSTEM ROUNDS THEBASE OF THE TROF AND ACCELERATES TO THE NE. LARGE-SCALE FORCING WLONCE AGAIN INCREASE WITH PVA ON THE TROP SFC NOTED FM ALL MODELS.THIS WL ONCE AGAIN LEAD TO DEFORMATION AND THEN FRONTOGENESISACRS OUR FA. ATTM IT APPEARS THE WEAKEST STABILITY...BESTFRONTOGENESIS ARND H6...AND BEST LARGE-SCALE FORCING WL LINE UP FMAROUND BIE TO AFK TO RDK AND POINTS SOUTH. THIS FORCING SHOULDCONT INTO TUES NIGHT AS THE 295 KE SFC INDCS A WEAK TROWAL DVLPGFM SRN IA BACK INTO SE NEB/NE KS AT THIS TIME. THIS IS LIKELY WHENOUR SRN FA IS LIKELY TO SEE THE HEAVIEST SNOWFALL. THE CNTRL CWA/ALNG THE I-80 CORRIDOR/ IS LIKELY TO SEE SOME ACCUMULATION FMBOTH PERIODS WHICH WL ADD UP AS WELL. EC IS MUCH STRONGER WITH THESFC LO THAN OTHER MODELS...BUT IS NOT OUT OF THE QUESTION. THISALSO LEADS TO STRONGER WINDS WITH A GOOD 50 KT AT 925 MB ON TUESINDCD FM THE EC. POINT FORECAST SOUNDINGS THOUGH INDC THAT THELOW-LEVEL LAPSE RATES ARE ONLY MARGINAL FOR MIXING THIS TYPE OFWIND TO THE SFC...AND THIS IS FAIRLY WELL AGREED UPON.THUS...ALTHOUGH WE ARE LIKELY TO SEE WINDY CONDS ON TUES/TUESNIGHT...WE DOUBT IF WE CAN MIX DOWN THE STRONGEST OF THE WINDS. SOATTM...IT APPEARS WE WILL HAVE CONSIDERABLE BLOWING AND DRIFTINGOF NEW SNOW...BUT WIDESPREAD AND SUSTAINED BLIZZARD CONDITIONSAPPEAR UNLIKELY ATTM. HELD ONTO THE SNOW IN THE THRU TUESNIGHT...BUT HAVE WED DRY WITH NO CHANGES TO THE FORECAST PASTTHUR.AS FAR AS HEADLINES. HAVE REDUCED SNOWFALL AMOUNTS MOSTAREAS...BUT ESPECIALLY IN THE NW WHERE WE NOW HAVE 2-4 INCHESGOING. ALTHOUGH WE WILL SEE SOME BLOWING AND DRIFTING...WEGENERALLY DO NOT FEEL WARNING CONDITIONS WILL BE MET FOR AREASSUCH AS OLU/OFK/LCG. NEVERTHELESS...SINCE CONDS ARE NOT EXPECTEDTO BE GREAT FOR TRAVELING WE WILL LEAVE THE WARNING GOING. DIDADJUST TIMING IN THE NW TO END EARLIER THOUGH ON TUES EVNG.WARNING STILL LOOKS ON TRACK FOR I-80 AND S THOUGH WITH NEARWARNING LEVEL SNOWS AND WIND. ADJUSTED THE TIMING THOUGH IN THEFAR S TO START AT 00Z AS LITTLE SNOW WILL FALL TODAY IN BIE/FNB.THESE AREAS THOUGH WILL SEE SOME FZDZ TODAY THAT MAY CAUSE SOMESLICK SPOTS THOUGH.BOUSTEAD

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no prob...did OAX put your area under a warning now?

they issued the warning yesterday afternoon , since then they been lowering the amounts

their afd said they lowered

AS FAR AS HEADLINES. HAVE REDUCED SNOWFALL AMOUNTS MOST

AREAS...BUT ESPECIALLY IN THE NW WHERE WE NOW HAVE 2-4 INCHES

GOING. ALTHOUGH WE WILL SEE SOME BLOWING AND DRIFTING...WE

GENERALLY DO NOT FEEL WARNING CONDITIONS WILL BE MET FOR AREAS

SUCH AS OLU/OFK/LCG. NEVERTHELESS...SINCE CONDS ARE NOT EXPECTED

TO BE GREAT FOR TRAVELING WE WILL LEAVE THE WARNING GOING. DID

ADJUST TIMING IN THE NW TO END EARLIER THOUGH ON TUES EVNG.

WARNING STILL LOOKS ON TRACK FOR I-80 AND S THOUGH WITH NEAR

WARNING LEVEL SNOWS AND WIND.

(new)FcstTotalSnowfallMap.png

(old)

post-556-0-10610700-1296470240.png

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DMX AFD:

AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE DES MOINES IA433 AM CST MON JAN 31 2011...MAJOR WINTER STORM SET TO AFFECT PORTIONS OF CENTRAL AND SOUTHERNIOWA TUESDAY AFTERNOON INTO WEDNESDAY MORNING....SHORT TERM /TODAY/...MAIN ASPECTS OF THE FORECAST CONTINUE TO BE ON TRACK AS INITIALNORTHERN STREAM SHORTWAVE DIGS INTO THE NORTHERN PLAINS THROUGH THEDAY...AS SOUTHERN STREAM SYSTEM BEGINS TO TAKE SHAPE ACROSS THE FOURCORNERS REGION. BROAD AREA OF MOISTURE ADVECTION/WAA AHEAD OF THETWO SYSTEMS WITH INITIAL FOCUS OF LARGER SCALE LIFT ACROSS THENORTHERN CWA THIS MORNING...THEN SPREADING SOUTHWARD ACROSS ENTIRECWA THIS AFTERNOON. HAVE ALREADY HAD SOME SNOW ACROSS THE EXTREMENORTH...AND EXPECT THIS AREA TO EXPAND WITH TIME AND INCREASE ININTENSITY THROUGHOUT THE MORNING INTO THE EARLY AFTERNOON HOURS ASENERGY MOVES THROUGH ALOFT. CONTINUE TO HAVE FOG/LIGHT FZDZ/FLURRIESREPORTED ACROSS THE SOUTHERN HALF OF THE CWA IN AREA OF STRONGTHETA-E ADVECTION IN THE LOWEST FEW LEVELS. NAM/RUC/SREF SHOW THISTHE DEPTH OF THE SATURATED LAYER INCREASING WITH TIME THIS MORNINGAND STRONG ISENTROPIC LIFT ON THE 275K TO 280K THETA SURFACES. THISLINES UP WELL WITH THE BATCH OF LIGHT FZRA/FZDZ ON RADAR MOVINGNORTHWARD ACROSS EASTERN KANSAS. THEREFORE EXPECT CHANCES FOR FZDZTO INCREASE THROUGH THE MORNING HOURS AND COULD RESULT IN A LIGHTGLAZING ON SURFACES. THERMAL PROFILES SHOULD COOL SUFFICIENTLY BYLATE MORNING INTO THE AFTERNOON HOURS FOR PRECIPITATION TO CHANGE TOALL SNOW WITH THE EXCEPTION OF THE FAR SOUTHEASTERN CWA WHEREPROFILES REMAIN A LITTLE WARMER SUGGESTING NO ICE INTRODUCTION UNTILTONIGHT. SNOW TOTALS THROUGHOUT THE DAYTIME HOURS SHOULD RANGE FROMAROUND 1 TO 2 INCHES ACROSS THE SOUTHERN HALF OF THE CWA TO 2 TO 3INCHES FURTHER NORTH. THEREFORE WITH THE SNOW TODAY AND CONTINUINGINTO TONIGHT...AND THE COMBINATION OF FZDZ/SNOW ACROSS THESOUTHWESTERN CWA HAVE EXPANDED THE WINTER WEATHER ADVISORY SOUTHWARDACROSS CENTRAL IOWA AND INTO SOUTHWESTERN IOWA..LONG TERM /TONIGHT THROUGH SUNDAY/...LIGHT SNOW WILL BE ONGOING ACRS MUCH OF THE FORECAST AREA THISEVENING AS WEAK ISENTROPIC LIFT CONTINUES. THIS LIFT WILL GRADUALLYDIMINISH OVERNIGHT WITH THE LIGHT SNOW TAPERING TO FLURRIES BYTUESDAY MORNING IN MOST LOCATION EXCEPT PERHAPS THE FAR SOUTH.ADDITIONAL ACCUMULATIONS OVERNIGHT OF 1 TO 3 INCHES WILL BE POSSIBLEWITH HIGHEST AMOUNTS ALONG AND NORTH OF INTERSTATE 80 TO HIGHWAY 20OR SO.FOCUS THEN TURNS TO SYSTEM EJECTING FROM THE SOUTHWEST UNITED STATESINTO THE CENTRAL US. INTENSE QG FORCING AND ISENTROPIC LIFT WILLRAPIDLY MOVE NORTHWARD INTO THE STATE DURING THE DAY AS UPPER SYSTEMDEEPENS QUICKLY. SNOW...MODERATE TO HEAVY WILL ENCOMPASS MUCH OFTHE FORECAST AREAS ALONG AND SOUTH OF HIGHWAY 20 BY TUESDAYEVENING. ATMOSHPERE BECOME WEAKLY STRATIFIED IN THE MID LEVELS BYLATE IN THE AFTERNOON WITH SOME CONVECTIVE POTENTIAL IN THE FARSOUTHEAST. SNOWFALL RATES BY LATE AFTERNOON MAY APPROACH 2 OR 3INCHES PER HOUR BY BLOOMFIELD/OTTUMWA. IN ADDITION...SYSTEM WILL BECOMPACT WITH TIGHT PRESSURE GRADIENT BETWEEN THE LOW AND A 1050MBHIGH IN THE NORTHERN PLAINS. IMPRESSIVE SOUNDING IN SOUTHEAST IAHAD 61KTS AT ABOUT 4KFT ON OTM SOUNDING AT 00Z WED BUT LOWER POTIONOF THE SOUNDING WAS NOT ADIABATIC WHICH WILL MAKE IT HARDER FORHIGHER WINDS TO REACH THE GROUND. NONE-THE-LESS... SUSTAINED WINDSOF 25 TO 30 MPH WITH HIGHER GUSTS WILL MAKE NEAR BLIZZARD TOBLIZZARD CONDITIONS POSSIBLE IN THE SOUTHEAST QUARTER OF THE CWAPOSSIBLE LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. THE SNOW WILLBEGIN TO END QUICKLY FROM WEST TO EAST EARLY WEDNESDAY AS SYSTEMRAPIDLY DEPARTS INTO THE OHIO RIVER VALLEY AND LOWER GREAT LAKES.WINDS WILL STILL PRODUCE SOME BLOWING SNOW INTO WEDNESDAY MORNINGBUT SUBSIDENCE AND ARCTIC AIRMASS SHOULD HAVE THE SUN TAKING OVER INMOST LOCATION BY MIDDAY.THE WINTER STORM WATCH HAS BEEN EXPANDED AND MODIFIED IN TIME TOACCOUNT FOR BEST THREAT AREA AND TO NARROW IN ON TIMING OFGREATEST THREAT. TOTAL SNOWFALL FROM THE STORM SHOULD RANGE FROMABOUT 6 INCHES ON THE NORTH EDGE OF THE WATCH TO 12 TO 16 INCHESNEAR BLOOMFIELD AND OTM. THIS WILL BE A VERY DANGEROUS AND CRIPPLINGSTORM GIVEN THE AMOUNT OF SNOW AND WINDS WITH TRAVEL BECOMINGDIFFICULT IF NOT IMPOSSIBLE EAST OF A TAMA-DES MOINES-BEDFORD LINE.DRIFTS WILL BE SEVERAL FEET DEEP BY WEDNESDAY MORNING ALONG WITHWIND CHILLS DROPPING INTO THE 20S BELOW ZERO. IF WINDS SHOW ANYTENDENCY TO BE HIGHER WITH SUBSEQUENT MODEL RUNS...A BLIZZARD WATCHOR WARNING MAY BE WARRANTED.WITH FOCUS ON UPCOMING STORM...CHANGED LITTLE IN FORECAST BEYONDWEDNESDAY.

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FWIW 06z NAM remains to the SE and taking a smoother path more E of NE through Southern Indiana and East Central Indiana into NW OH. Which will support a long duration icing event for Central Indiana. 06z GFS lined back up with this solution rather than the abrupt occluded and rapid NNE solution at 00z. (That Euro, UKMET and GEM) supported. Needless to say, 12z will be interesting this afternoon. NWS IND and NWS PAH seem to have the same concern of this solution. The variation of this path will mainly impact Central/ South Central Indiana, Western/Northwestern OH and Southern Michigan

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NWS BUF

FOLLOWING THIS...THE MAIN STORM SYSTEM WILL IMPACT THE REGION

TUESDAY NIGHT THROUGH WEDNESDAY.

WATER VAPOR IMAGERY EARLY THIS MORNING SHOWING UPPER WAVE DIGGING

THROUGH THE DESERT SOUTHWEST. THIS WAVE WILL EJECT RAPIDLY

NORTHEAST AROUND THE DIGGING INTERMOUNTAIN UPPER TROUGH INTO THE

PLAINS...AND UP THROUGH THE NORTHERN OHIO VALLEY/SOUTHERN GREAT

LAKES BY WEDNESDAY. THERE IS NO SHORTAGE OF DYNAMICS WITH THIS

SYSTEM. MODELS ADVERTISING A VERY IMPRESSIVE UPPER LEVEL JET

COUPLING RIGHT THROUGH THE LOWER LAKES REGION...ALONG WITH AN

ANOMALOUSLY STRONG 65 TO 75 KNOT SOUTHERLY LOW LEVEL JET...5

STANDARD DEVIATIONS ABOVE NORMAL...FORCING OUTSTANDING VERTICAL

MOTION ALONG A TREMENDOUS BAROCLINIC ZONE WHICH WILL EXTEND FROM

THE NORTHERN OHIO VALLEY/SOUTHERN LAKES THROUGH WESTERN NEW YORK.

MODEL QPF ALMOST UNANIMOUS IN SHOWING AMOUNTS OVER AN INCH.

PRECIPITATION TYPE FOR THE MOST PART IS NOT IN QUESTION. AIR MASS

SHOULD BE COLD ENOUGH WITH THE ARCTIC HIGH JUST OFF TO THE NORTH

SUPPLYING FRESH COLD AIR SOUTHWARD FOR AN ALL SNOW SETUP. THE

EXCEPTION MAY BE ALONG THE SOUTHERN TIER...WHERE THERE MAY BE

ENOUGH OF A SURGE OF WARM AIR ALOFT TO BRING THE THREAT FOR A MIX

WITH SLEET. THIS IS SUGGESTED BY THE WARMER GFS.

WIDESPREAD SNOWFALL AMOUNTS IN THE 8 TO 16 INCH RANGE WILL BE

LIKELY...WITH THE BULLSEYE FOR HEAVIEST AMOUNTS FROM THE BUFFALO

TO ROCHESTER TO WATERTOWN CORRIDOR. WE WILL NEED TO BE AWARE OF THE

POTENTIAL FOR DIMINISHED AMOUNTS DUE TO THE SUGGESTION OF A SHARP

DRY SLOT NOSING NORTHWARD ON WEDNESDAY...BUT LIKELY NOT CUTTING

AMOUNTS BELOW WARNING CRITERIA.

IT APPEARS THIS WILL BE A FAIRLY RAPID MOVING SYSTEM...BUT THERE

WILL LIKELY BE A PERIOD OF SEVERAL HOURS...PROBABLY IN THE 06Z/09Z

TO 15Z/18Z TIME FRAME AS A BEST GUESS...WHEN THE SNOWFALL COULD

BE INTENSE WITH RATES EASILY EXCEEDING AN INCH PER HOUR WITH THE

POTENTIAL FOR THUNDER AND LIGHTNING. THIS TIMING WOULD RESULT IN

EXTREMELY HAZARDOUS CONDITIONS DEVELOPING FOR THE WEDNESDAY

MORNING COMMUTE. WIDESPREAD HEAVY SYNOPTIC SNOWS ARE NOT THE NORM

FOR WESTERN NEW YORK...SO IT WILL BE INTERESTING FOR SURE TO SEE

HOW THIS ALL PLAYS OUT.

IN ADDITION TO THE POTENTIAL FOR HEAVY SNOW...A BRISK NORTHEAST WIND

WILL DEVELOP AS THE PRESSURE GRADIENT TIGHTENS WHICH WILL CAUSE A

BLOWING SNOW PROBLEM AS WELL...ESPECIALLY CLOSER TO LAKE ONTARIO.

THE STEADY SYNOPTIC SNOW WILL TAPER OFF FROM WEST TO EAST WEDNESDAY

NIGHT HEADS OUT INTO THE ATLANTIC. THE NORTHWEST FLOW BEHIND THE

DEPARTING STORM WILL GENERATE SOME LAKE EFFECT SNOW SOUTHEAST OF

LAKE ONTARIO.

:arrowhead:
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looks like athe downward trend has begun. Should still be great, but historic is looking less likely. 100+ year records are 100+ year records for a reason.

...LAKESHORE FLOOD WATCH IN EFFECT FROM TUESDAY EVENING THROUGH

WEDNESDAY AFTERNOON...

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A LAKESHORE

FLOOD WATCH...WHICH IS IN EFFECT FROM TUESDAY EVENING THROUGH

WEDNESDAY AFTERNOON.

NORTHEAST WINDS WILL INCREASE TO 30 TO 40 MPH WITH GUSTS OF 50 TO

60 MPH POSSIBLE. THESE STRONG WINDS WILL LIKELY RESULT IN WAVES

BUILDING TO 14 TO 18 FT...WITH OCCASIONAL WAVES UP TO 25 FT.

WAVES OF THIS MAGNITUDE WOULD LIKELY RESULT IN SIGNIFICANT BEACH

EROSION AND COASTAL FLOODING. PORTIONS OF LAKE SHORE DRIVE AND

OTHER FLOOD PRONE AREAS NEAR THE LAKE WOULD LIKELY EXPERIENCE

OVER WASH FROM HIGH WAVES.

SATELLITE IMAGERY DOES INDICATE THAT THERE IS SOME ICE OFFSHORE

WHICH COULD POTENTIALLY RESULT IN LOWER WAVES AND A LESSER THREAT

OF LAKESHORE FLOODING. IT IS IMPOSSIBLE TO PREDICT TO WHAT DEGREE

ANY ICE MAY LESSEN THE FLOOD THREAT...SO INTERESTS NEAR THE SHORE

SHOULD BE PREPARED FOR AND EXPECT TO ENCOUNTER LAKESHORE FLOODING

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to be fair that poster was from an area NW of the city where QPF is now down to around .5-.75, it could be wrong, but he's not totally off base with 8" expectations.

I am in Des Plaines, IL and I am nowhere near the .5-.75 liquid. I am exactly on northern fridge of 1.00-1.25 liquid. This is going to wiggle the next 30hrs so I am not to worried but I am surprised they are going with 8-14 inches but they did mention addition accumulations Wednesday. I guess GFS still reasonable. It is still 12-15 with a 12:10 ratio from I'd say ORD to Gary. I just dont see understand so much with the low ratios with temps in the low/mid 20s throughout most of event considering its at night-time. It could end up be a similar set-up to what happened to New York/Boston area with the last storm that brought unexpectedly a bit more snow than thought.

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