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January 17-19th Plains/MW/Lakes Storm Potential


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As BI might have been stating earlier about the 12z NAM (maybe he was hinting at something else)

THE 12Z NAM IS ON THE SLOW SIDE OF

THE GUIDANCE WHILE THE 00Z ECMWF/06Z GFS ARE ON THE QUICK SIDE.

THERE IS A KICKER SHORTWAVE /IN THE FORM OF AN UPPER LOW IN

SASKATCHEWAN/ UPSTREAM...AND THE NAM HAS A SLOW BIAS WITH SYSTEMS

2-3 DAYS INTO THE FUTURE...SO BELIEVE THE 12Z NAM/00Z CANADIAN

SOLUTIONS ARE TOO SLOW WITH ITS PROGRESSION. THE ENSEMBLE SPREAD

WITH THE SURFACE LOW IS NOW LARGER THAN THE DETERMINISTIC SPREAD.

BECAUSE OF THIS...WILL PREFER A GENERAL MODEL COMPROMISE PENDING

THE RECEIPT OF THE 12Z ECMWF.

HPC

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As BI might have been stating earlier about the 12z NAM (maybe he was hinting at something else)

THE 12Z NAM IS ON THE SLOW SIDE OF

THE GUIDANCE WHILE THE 00Z ECMWF/06Z GFS ARE ON THE QUICK SIDE.

THERE IS A KICKER SHORTWAVE /IN THE FORM OF AN UPPER LOW IN

SASKATCHEWAN/ UPSTREAM...AND THE NAM HAS A SLOW BIAS WITH SYSTEMS

2-3 DAYS INTO THE FUTURE...SO BELIEVE THE 12Z NAM/00Z CANADIAN

SOLUTIONS ARE TOO SLOW WITH ITS PROGRESSION. THE ENSEMBLE SPREAD

WITH THE SURFACE LOW IS NOW LARGER THAN THE DETERMINISTIC SPREAD.

BECAUSE OF THIS...WILL PREFER A GENERAL MODEL COMPROMISE PENDING

THE RECEIPT OF THE 12Z ECMWF.

HPC

Jerry Jerry. you will love this forecast : http://forecast.weather.gov/MapClick.php?CityName=Sterling+Heights&state=MI&site=DTX&lat=42.58&lon=-83.0305

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dtx

SATELLITE DATA AND THE 12Z UPPER AIR NETWORK SHOW A STRONG UPPER JET/160-170 KTS/ STRETCHING ACROSS THE PACIFIC NORTHWEST AND SOUTHWESTCANADA. OBSERVATIONS INDICATE THIS JET IS A BIT STRONGER THANEARLIER MODEL SOLUTIONS SUGGESTED. IT HAS ALSO NOT BEEN SAMPLED TOOWELL BY THE UPPER AIR NETWORK. THE MODELS ALSO CONTINUE TO LOOK ABIT TOO WEAK WITH THE STRENGTH OF THE UPPER JET OFF THE COAST. THISWILL CONTINUE TO ADD SOME UNCERTAINTY WITH RESPECT TO TIMING ANDAMPLITUDE OF THE DOWNSTREAM TROUGH FORECAST TO PRODUCE A PROLONGEDPERIOD OF PRECIPITATION ACROSS SE MI LATE MONDAY THROUGH POSSIBLYTUESDAY NIGHT. RECENT OBSERVATIONAL DATA AND MODEL TRENDS SUPPORT AMORE AMPLIFIED AND SLOWER TIMING OF THE MID LEVEL TROUGH FORECAST TODEEPEN OVER THE MIDWEST MONDAY NIGHT INTO TUESDAY.SOUTHERLY FLOW WILL DEVELOP ACROSS THE OHIO VALLEY AND GREAT LAKESREGION ON MONDAY IN THE WAKE OF THE DEPARTING SURFACE HIGH TO THEEAST AND SURFACE LOW ADVANCING INTO THE UPPER MIDWEST. THIS WILL SETUP A PROLONGED PERIOD OF MOISTURE AND LOW LEVEL THERMAL ADVECTION.THE 12Z MODEL SUITE CONTINUE TO SHOW ISENTROPIC ASCENT DEVELOPINGOVER THE AREA ON MONDAY AND CONTINUING INTO THE DAY TUESDAY.OVERALL...ASCENT LOOKS FAIRLY WEAK ACROSS MOST OF THE AREA. THEMODEL SOLUTIONS ARE HOWEVER INDICATING SOME STRONGER FORCINGASSOCIATED WITH LOWER TROPOSPHERIC FRONTAL DYNAMICS STRETCHING FROMSW LOWER MI INTO NE LOWER MI...INCLUDING PORTIONS OF THE SAGINAWVALLEY.RESIDUAL COLD AIR WILL ALLOW PRECIPITATION TO START AS ALL SNOW MONAFTERNOON AND EVENING. MODEL SOUNDINGS INDICATE LOW LEVEL WARMINGWILL CAUSE A TRANSITION Iarrowheadsmiley.pngN PRECIP TYPE MON NIGHT. ALTHOUGH NOT TOOTERRIBLY WARM..yikes.png.MODEL SOUNDINGS DO SHOW A FAIRLY DEEP WARM LAYERADVECTING INTO THE LOW LEVELS /NEARLY 5K FT AROUND DETROIT ANDPOINTS SOUTH BY 12Z TUES/. THE DEPTH OF THE WARM LAYER WILL CAUSEPRECIP TO TRANSITION TO LIQUID FROM SOUTH TO NORTH MON NIGHT INTOTUES MORNING.yikes.png SURFACE WET BULB TEMPS ARE STILL FORECAST TO BE AT ORBELOW FREEZING INTO DAYBREAK TUESDAY...WHICH WILL CONTINUE TOWARRANT A MENTION OF FREEZING RAIN MONDAY NIGHT. THE SURFACE WINDSWILL REMAIN OUT OF THE SOUTH THROUGH THE DAY TUESDAY. THIS ALONGWITH CONTINUED LOW LEVEL MOISTURE ADVECTION SHOULD PUSH TEMPS ABOVEFREEZING NEAR OR SHORTLY AFTER DAYBREAK TUESDAY. OUTSIDE OF THESAGINAW VALLEY AND THUMB...PRECIPITATION ON TUESDAY WILL LIKELY BEALL RAIN OR A MIX OF RAIN AND SNOW WITH TEMPS IN THE MID TO UPPER30S. SNOW AND ICE ACCUMULATIONS ARE EXPECTED TO BE LIGHTaxesmiley.png THROUGHTHIS EVENT. THE NORTHERN PORTIONS OF THE CWA HOWEVER /TRI CITIES ANDTHUMB/ MAY SEE IN EXCESS OF 2 OR 3 INCHES OF SNOW AND SLEET DUE TOSTRONGER FORCING AND A COLDER LOW LEVEL AIR MASS.THE LATEST NAM AND CANADIAN SOLUTIONS SHOW A SECONDARY SURFACE LOWDEVELOPING OVER ILLINOIS ON TUES AND TRACKING ACROSS THE EASTERNOHIO VALLEY TUES NIGHT BEFORE BEING ABSORBED INTO AN INTENSIFYINGNEW ENGLAND STORM SYSTEM...WHICH SEEMS PLAUSIBLE IN THE EVENT OF ADEEPER AND SLOWER MIDWEST TROUGH. THIS WILL OPEN THE DOOR FOR SOMEDEFORMATION TYPE FORCING OVER SE MI LATE TUES INTO TUES NIGHT ASCOLDER AIR FILTERS BACK INTO THE AREA AND TRANSITIONS THINGS BACKOVER TO ALL SNOW. AT THIS TIME...HAVE EXTENDED A CHANCE OF SNOWTHROUGH TUES NIGHT. MUCH COLDER AIR WILL FILTER BACK INTO THE STATEBY MID WEEK IN THE WAKE OF THIS STORM SYSTEM.

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I honestly think it will get above freezing, maybe 33-37 for 12 or so hours, see some snow, sleet, drizzle then hopefully a secondaey develops and replenishes the snow pack we lost. Also I hope the left over energy scoots out for the next storm

I bet we dont touch 37 degrees at least 696 northward. Its more like 33-35 degrees at best :popcorn:

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I bet we dont touch 37 degrees at least 696 northward. Its more like 33-35 degrees at best :popcorn:

LOL aiden is going to get a good laugh but this reminds me of the dec 12 storm. First storm sort of fizzels out and a secondary pops up and delivers a few inches. Remember the models didnt pick that secondary up until like 24 hours before.

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Jerrys Favorite.

GRR

OVERALL I LEFT THE FORECAST PRECIPITATION TYPES AND TIMING LARGELYALONE. TO START MODELS DID NOT FORECAST OR INITIALIZE THE WARMERAIRMASS DOWN IN THE LOWER MS VALLEY VERY WELL THIS MORNING. THIS ISWHERE OUR MOISTURE WILL BE ARRIVING FROM. LIT SOUNDING FEATUREDMUCH WARMER VALUES THAN INITIALIZED BY ANY MODEL. WHEN THE 12Z RUNSFINISHED...I WAS PREPARED TO LOWER TEMPERATURES A DEGREE OR TWO ANDFEATURE MORE WINTRY PRECIPITATION. HOWEVERyikes.png THE 12Z HIGH RES EUROCAME IN AND STILL SHOWED TEMPERATURES THAT SUPPORTED THE CURRENTFORECAST. THIS COOLER TREND SHOWN BY THE GFS AND NAM...I AM NOTSURE WILL MATERIALIZE...SO I KEPT THE IDEA OF ABOVE FREEZINGTEMPERATURES GOING EVEN NORTH OF GRR ON TUESDAY. WE MAY STILL NEEDHEADLINES FOR THE WINTRY WEATHER. RIGHT NOW I AM LEANING TOWARDTHIS AS AN ADVISORY EVENT FOR PARTS OF THE AREA. LIFT IS NOT STRONGAND THE SURFACE WAVE SHOWS A WEAKENING TREND...SOMEWHAT LIMITINGFACTORS.yikes.pngTEMPERATURES COULD GO SUBZERO IF THERE ARE SEVERAL HOURS OF CLEARINGTONIGHT. CLEARING IS OCCURRING IN WRN WISCONSIN...WHICH WILL HAVETO BE MONITORED. I AM ALREADY SEVERAL DEGREES UNDER THEGUIDANCE...BUT NOT ENOUGH IF WE DO CLEAR OUT.VISIBLE IMAGERY DOES SHOW A SWIRL OF CLOUDS SOUTHEAST OF KMKE. SOMEMESOSCALE MODELS YESTERDAY DID SHOW THIS MESO LOW FORMING.&&.LONG TERM...(355 PM EST SUN JAN 16 2011)(WEDNESDAY THROUGH SUNDAY)THE MEDIUM RANGE MODELS HAVE PULLED BACK A BIT ON THE ARCTIC BLASTFOR THE LATTER PORTION OF THE WEEK. LOOKS LIKE IT STILL OCCURS...BUT IT IS SLOWER TO MOVE IN...AND QUICKER TO EXIT. COLDEST AIRSHOULD BE OVER US THURSDAY NIGHT AND FRIDAY WITH H8 TEMPS AROUND-18C WHEN LOW TEMPS WILL BE IN THE SINGLE DIGITS OR JUST BELOW ZEROACROSS INTERIOR AREAS. MEANWHILE...HIGHS ON FRIDAY WON/T GET OUT OFTHE TEENS.IN GENERAL THIS SHORTER EXTENDED PERIOD OF ARCTIC AIR SEEMS TO BECOMING INTO THE PICTURE SINCE THE FLOW IS TOO PROGRESSIVE...NOTALLOWING THE ARCTIC HIGH TO SIT IN PLACE AND FUNNEL THE COLD AIRINTO THE EASTERN U.S. INSTEAD THE MODELS SHOW WARM ADVECTION INTOFRIDAY NIGHT AS THE ARCTIC HIGH DRIFTS TO OUR EAST. DON/T GET THEWRONG IDEA...ITS GOING TO BE VERY COLD...ITS JUST THAT THE BITTERCOLD OCCURS OVER A SHORTER PERIOD.NO STORMS TO REALLY SPEAK OF. EVEN THE LAKE EFFECT LOOKS MINIMAL.WE WILL PROBABLY SEE SOME THROUGH THURSDAY NIGHT...ALONG WITH SOMELIFT FROM THE ARCTIC FRONT LATE WED NIGHT/EARLY THU. OTHERWISE THEARCTIC HIGH WILL LIKELY DISRUPT MOST OF THE SNOW SHOWERS FRIDAY ANDSATURDAY. lmaosmiley.gifyikes.pngpopcorn.gifguitar.gifgun_bandana.gifdevilsmiley.gifTHEN SOME MAY RESUME SUNDAY AS THE FLOW GOES SW.

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LOL aiden is going to get a good laugh but this reminds me of the dec 12 storm. First storm sort of fizzels out and a secondary pops up and delivers a few inches. Remember the models didnt pick that secondary up until like 24 hours before.

You never know if we get some moisture in with that secondary low which is very possible even DTX pointed it out...it could be a repeat, or were just doing a lot of :blahblah: and will get nothing more then an inch or two :yikes:

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You never know if we get some moisture in with that secondary low which is very possible even DTX pointed it out...it could be a repeat, or were just doing a lot of :blahblah: and will get nothing more then an inch or two :yikes:

TrUE that, or maybe the N/E will see another

:DDDDD

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MKE going with a WWA for most of the cwa except Janesville, Kenosha, Racine, and Walworth.

TIMING...SNOW WILL MOVE INTO THE AREA BY DAYBREAK. THE HEAVIEST

SNOW WILL GENERALLY BE FROM MID MORNING INTO THE EVENING.

* SNOW ACCUMULATIONS...3 TO 5 INCHES.

* WINDS...SOUTH WINDS 10 TO 15 WITH GUSTS TO 20 MPH...DIMINISHING

IN THE EVENING.

* IMPACTS...ROADS MAY BECOME SNOW COVERED AND

SLIPPERY...ESPECIALLY IF UNTREATED. LOCAL VISIBILITY REDUCTIONS

TO ONE HALE MILE OR LESS ARE ALSO POSSIBLE.

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We are above freezing all day tomorrow, tomorrow night, and Tuesday...

Sloppy, sloppy mess on the way... I'll bet we transition to rain for the last half of this system.

This is my "2 inches of slop" system.

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DVN has been forecasting all snow for the QC up until this afternoon, but now believes we'll see a slopfest here as well. Not looking good for us. The 18z GFS is a touch warmer than the 12z here, so it's now looking like we may struggle to get an inch or two before going over to rain. Cedar Rapids to Dubuque still looks good though.

...AND GIVEN THE BETTER PERFORMANCE AND

CONSISTENCE OF THE NAM AND ECMWF COMBINED...HAVE USED THEM FOR THE

MOST PART TODAY. THIS WARMER SOLUTION BRINGS ENOUGH WARMER

TEMPERATURES ALOFT THAT FREEZING RAIN AND SLEET ARE A FORECAST

CONCERN WELL UP INTO THE INTERSTATE 80 CORRIDOR...AND TURNING THE

SOUTHEASTERN FOURTH TO THIRD OF COUNTIES TO ALL RAIN FOR THE

AFTERNOON HOURS...DEPENDING ON HOW SURFACE TEMPERATURES BEHAVE WITH

THE SNOW STILL ON THE GROUND. ALONG THE HIGHWAY 20 CORRIDOR

TEMPERATURES SHOULD STAY COLD ENOUGH FOR ALL SNOW...BUT THE WARMER

TEMPERATURES ALOFT ARE GOING TO EAT INTO THE SNOWFALL AMOUNT

TOTALS.

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Both sides of Lake Michigan, E-W, are in good shape. I think the increased organization of the 18Z GFS is quite realistic as well as this storm is hauling a nice 160+ kt jet and it doesn't take much of a wave and/or phasing of waves to develop a more organized system. 0Z guidance tonight will be telling as most of the off-shore cyclone/upper wave will have been ripped to shreds by the coastal ranges--and we will know how much of an intact wave is left.

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I've got a MBY question for the local dudes here and hopefully some red taggers. It is looking like central and especially Northern IN is looking at a snow-to-freezing rain/rain-to-snow mess, as hosier has alluded to several times. A quote from this morning's IWX disco has me concerned for a prolonged freezing rain event:

MODELS ALL SEEM TOO WARM IN NEAR SURFACE LAYER AND WITH 2M TEMPS MONDAY NIGHT

OVER DEEP AND EXTENSIVE SNOW PACK THAT EXTENDS BACK INTO MO AND NE.

MODELS LIKELY NOT HANDLING SHALLOW COLD WEDGE THAT WILL BE DIFFICULT

TO REMOVE FROM THE AREA. OVERALL WARM AIR IN THE 925MB TO 850MB

LAYER DOES NOT SEEM WARM ENOUGH TO BRING SFC TEMPS ABOVE FREEZING SO

QUICKLY GIVEN THIS COLD WEDGE.

It seems that, ancetdotally, that shallow, cold air gets shoved/mixed out

efficiently in our region with this type of set up. Any thoughts yet on where/if a significant zr threat exists?

I am asking due to concerns from an Emergency Management standpoint. Ice storms make my life pure hell.

The warm layer aloft isn't that warm, but with southerly flow from the surface on up, I don't see how surface temps can stay below freezing. In marginal scenarios like this, I've found it's usually better to lean warmer.

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The warm layer aloft isn't that warm, but with southerly flow from the surface on up, I don't see how surface temps can stay below freezing. In marginal scenarios like this, I've found it's usually better to lean warmer.

I completely agree, the warmer scenario almost always winds. I have also found that a lot of the offices and mets hang their hats on colder road and surface temperatures, thus increasing the freezing rain potential at onset. I have found in most cases in our area that once the air temperature is above freezing, it doesn't take long for surface and road temps to respond either (even after long cold spells).

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I completely agree, the warmer scenario almost always winds. I have also found that a lot of the offices and mets hang their hats on colder road and surface temperatures, thus increasing the freezing rain potential at onset. I have found in most cases in our area that once the air temperature is above freezing, it doesn't take long for surface and road temps to respond either (even after long cold spells).

Yeah, I guess it's possible the ground/object temps could lag a bit, but I'm pretty certain the 2m temps will go above freezing. If we had easterly flow in the low levels it would be a different story.

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