Oklahoma Weather Discussion - February/March 2013

[Anonymous.]

GFS totally nailed that persistent band of snow in far E OK along I-40.


Tonight is another tough forecast. Sleet/snow/freezing rain showers popping up and riding over colder air over much of OK at the moment.

Temperatures the last few hours have began to fall once again as we approach evening. Ground temperatures are in the upper 30s over mosts of OK with the exception of mid 40s in the SW and close to freezing in the E where there is packed snow on the ground.


With all that said, I am not sure what to expect tonight - will wait for models runs within the hour.

[OKCDrummer77]

Just now starting to sleet here at Britton Rd & Hefner Pkwy.

[OKCisOK4me]

Any predictions for tonight?

A 100% chance of it being dark outside

[blangtang]

I haven't look at the weather forecast lately, and now they are saying power outages!

[OKCDrummer77]

That was a weird drive home. In 20 minutes, I had nothing -> light rain -> nothing -> heavy rain -> sleet -> nothing.

[OKCisOK4me]

Link?

Lololol

[SomeGuy]

Well Mike Morgan said on Channel 4 that we could possibly have ice in the morning with slick and hazardous roads as well as Power Outages. This is going to be unplesent, especially since I have school

[Anonymous.]

Well the NWS going for mostly rain over OKC metro once again for tonight.


And once again I have some doubts. A couple things here, temperatures are hovering around 33-34F. Light surface winds out of the east are bringing in refrigerated air off of the snow pack in E C OK. Wetbulb temps are drifting down to right around freezing (33F currently). Ground temperatures have fallen since precip started early Wednesday morning. N OKC is around 36-37, S OKC around 37-38.

Warmer air aloft will work in throughout the night, but nighttime cooling with evaporation cooling will also be occurring. This is going to be another battle zone over C OK tonight. With all the factors mentioned above, I would not be surprised if OKC sees ice on trees/lines/bridge with snow moving in towards morning hours. It could be a total nightmare if temperatures get to 32 for a while or even lower - but on the other hand it could be 34 degrees all night and everyone flies to work @ 80mph in the rain as usual.

[ZYX2]

It has been sleeting off and in here for a while now. At times very heavily. It's accumulating on sidewalks but not really n roads. I expect that slick spots will develop soon.

[PennyQuilts]

What part of the city are you in, ZYX2?

[ZYX2]

What part of the city are you in, ZYX2?

Sorry, meant to add "in Tulsa" to that.

[PennyQuilts]

Looks like Tulsa is likely to get hit hard. I'm wondering how it is looking for Edmond and if they will cancel any school in this area.

[venture]

Sorry...had stuff to do this evening. Umm latest HRRR has us with mostly rain until 1AM and then starts mixing in some snow. By 3AM looks like a transition to icing will take place and should last until the precip exits the area around 9AM. We are looking at maybe another half inch to an inch of precip over most of Central OK by the time it ends.

In addition to the Winter stuff, Severe Weather is a risk over much of the area from Norman to Ada to Durant and back to the west and south of I-40. The area about 30-40 miles either side of I-40 will probably be the most confusing to forecast in this since storms could make it up in this area. If we have icing conditions, any storms will increase the amounts significantly and cause major problems.

Instability Forecasts


CAPE


Snowfall Forecasts...

[Mississippi Blues]

Link?

Thank you.. Thank you very much.

[Anonymous.]

Rain pockets developing all over SW OK right now as the next piece of energy moves into NW TX.


One thing beginning to concern me is the pocket of low level dry air sneaking into C OK from the SE. Checking on dewpoints, there is a stream of dry air that is being pushed into the southern and central parts of the state by the surface winds. Looking @ wet-bulb profiles, this air can cool to 31-32 pretty easily. I don't think it will penetrate into the OKC metro as the winds are not very strong - but if it does, there could be a surprise significant icing event over populated areas.

[venture]

MESOSCALE DISCUSSION 0179
NWS STORM PREDICTION CENTER NORMAN OK
1052 PM CST WED FEB 20 2013

AREAS AFFECTED...PARTS OF WEST CENTRAL THROUGH NW TX AND SWRN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210452Z - 210645Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
THROUGH THE LATE EVENING INTO THE EARLY OVERNIGHT HOURS...INITIALLY
ACROSS WEST CENTRAL TX...AND THEN DEVELOPING/SPREADING E/NEWD ACROSS
NW TX TO SW-SRN OK. HAIL WILL BE THE GREATEST THREAT...GIVEN THAT
THIS ACTIVITY WILL TEND TO REMAIN ELEVATED.

DISCUSSION...TRENDS IN WIND PROFILER DATA AT JAYTON TX AND
SURROUNDING WSR-88D VWP DATA ACROSS THE WRN HALF OF TX HAVE
INDICATED AN INCREASE IN A SSELY LLJ /UP TO 50 KT/. THIS IS
RESULTING IN INCREASING LOW LEVEL MOISTURE RETURN AND WAA NORTH OF A
SURFACE WARM FRONT WHICH EXTENDED EWD FROM AN AREA OF LOW PRESSURE
LOCATED ALONG THE BORDER OF SRN WARD/ERN REEVES COUNTIES TX THROUGH
THE VICINITY OF KAUS TO KHOU. TWO PARALLEL NNE-SSW ORIENTED BANDS OF
TSTMS IN WEST CENTRAL TX TO FAR SERN NM PER REGIONAL RADAR IMAGERY
APPEAR TO BE DELINEATING THE LEADING EDGE OF DEEP LAYER FORCING...
BEGINNING TO SPREAD INTO W/NW TX AHEAD OF THE POWERFUL SWRN STATES
UPPER LEVEL LOW AND INTERCEPTING THE NWWD EXTENT OF THE MOISTURE
RETURN. AT 04Z...OBJECTIVE ANALYSES SHOWED MUCAPE RANGING FROM
500-1000 J/KG FROM N-S ALONG THE LEADING BAND OF CONVECTION. THE
RECENT 00Z RUNS OF THE 4 KM WRF-NMM/NSSL WRF-ARW EACH SUGGEST THE
ERN MOST BAND OF STORMS BECOMES THE PRIMARY ONE WITH A FAIRLY RAPID
INCREASE IN NWD AND SWD DEVELOPMENT BETWEEN 06-09Z INTO PARTS OF
CENTRAL AND NORTH CENTRAL TX TO CENTRAL OK. THIS MARKED INCREASE IN
STORM COVERAGE IS LIKELY DUE TO THE GREATER ASCENT SPREADING ENEWD
INTO THE SRN PLAINS AND AS LOW LEVEL WAA INCREASES ALONG A FURTHER
STRENGTHENING SLY LLJ INTO NW-N CENTRAL TX TO CENTRAL OK. EFFECTIVE
BULK SHEAR OF 40-70 KT IS ALREADY MORE THAN SUFFICIENT TO SUPPORT
STORM ORGANIZATION/ROTATING UPDRAFTS.

THE INITIAL MARGINAL ELEVATED INSTABILITY MAY TEND TO LIMIT THE
COVERAGE OF STRONGER...SUSTAINED STORMS AND THUS RESULTS IN A LOWER
PROBABILITY FOR WATCH ISSUANCE AT THIS TIME. GREATER CONCERN FOR AN
INCREASED THREAT FOR LARGE HAIL MAY NOT OCCUR UNTIL AROUND 09Z. AT
THAT TIME...STRONGER ASCENT...GREATER MIDLEVEL COOLING AND A FURTHER
INCREASE IN LOW LEVEL MOISTURE/WARM AIR ADVECTION WILL BE UNDERWAY
INTO NW-NORTH CENTRAL TX AND SRN OK SUGGESTING A WATCH COULD BE
NEEDED DURING THE OVERNIGHT PERIOD.

..PETERS/MEAD.. 02/21/2013

[venture]

Rain pockets developing all over SW OK right now as the next piece of energy moves into NW TX.


One thing beginning to concern me is the pocket of low level dry air sneaking into C OK from the SE. Checking on dewpoints, there is a stream of dry air that is being pushed into the southern and central parts of the state by the surface winds. Looking @ wet-bulb profiles, this air can cool to 31-32 pretty easily. I don't think it will penetrate into the OKC metro as the winds are not very strong - but if it does, there could be a surprise significant icing event over populated areas.

This scares the crap out of me a bit...

Loop

Squall line feature gets here and its all forecast as freezing rain/ice. Would not be a fun rush hour.

[Mississippi Blues]

As a school kid that drives himself to school, I'd like to get some weather folks opinion on a pretty generic question for such a complex thread... Does it look like there will be many school closings in the morning?

[venture]

As a school kid that drives himself to school, I'd like to get some weather folks opinion on a pretty generic question for such a complex thread... Does it look like there will be many school closings in the morning?

Don't ask me. I went to school up north. We didn't close school unless the roads were snow packed with more than 6", wind chills under 20 below, or significant icing. Otherwise most schools just ran 1 to 2 hour delays...which I don't think I've ever seen done down here.

[Video Expert]

As a school kid that drives himself to school, I'd like to get some weather folks opinion on a pretty generic question for such a complex thread... Does it look like there will be many school closings in the morning?

Depends on where you are. If your talking about schools in the OKC Metro...I'd plan on schools being in session at this point. It's rather complicated to be sure, so my advice is to get up a little earlier than usual just to see where things are in 6-7 hrs.

[Mississippi Blues]

Depends on where you are. If your talking about schools in the OKC Metro...I'd plan on schools being in session at this point. It's rather complicated to be sure, so my advice is to get up a little earlier than usual just to see where things are in 6-7 hrs.

Yes, I'm in the OKC metro (36th and Classen area). I shall do that. Thank you!

[ZYX2]

32 degree line closing in on Bixby. GET HERE!

[venture]

MESOSCALE DISCUSSION 0180
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CST WED FEB 20 2013

AREAS AFFECTED...NERN TX PANHANDLE...ERN OK PANHANDLE...NWRN AND
N-CNTRL OK...SRN KS

CONCERNING...WINTER MIXED PRECIPITATION

VALID 210549Z - 211145Z

SUMMARY...INCREASING PRECIPITATION RATES...WITH PREDOMINANTLY MIXED
P-TYPES INITIALLY...ARE FORECAST THROUGH EARLY THU MORNING. A
TRANSITION TO HEAVY SNOWFALL MAY OCCUR IN A SW-NE CORRIDOR FROM THE
NERN TX PANHANDLE INTO S-CNTRL KS...WHILE A MORE UNCERTAIN/MIXED
P-TYPE IS LIKELY ACROSS NWRN AND N-CNTRL OK.

DISCUSSION...STRONG ASCENT ASSOCIATED WITH UPPER DIVERGENCE AHEAD OF
A SWRN CONUS UPPER TROUGH IS OVERSPREADING RICHER TROPOSPHERIC
MOISTURE ACROSS THE SRN HIGH PLAINS...RESULTING IN AN INCREASE IN
PRECIPITATION /PER RECENT RADAR LOOPS/. THIS TREND IS EXPECTED TO
CONTINUE...WITH WIDESPREAD PRECIPITATION DEVELOPING ACROSS THE ERN
TX/OK PANHANDLES AND INTO WRN OK...AS THE AFOREMENTIONED LIFT
BECOMES JUXTAPOSED WITH ISENTROPIC ASCENT FOCUSED WITHIN THE 300-306
K LAYER.

THE SFC FREEZING LINE...POSITIONED FROM 40 ESE GUY TO 30 E AVK PER
05Z OBSERVATIONS...IS FORECAST TO SLOWLY SAG SWD AS MODEST BOUNDARY
LAYER COOLING OCCURS /AS SUPPORTED BY 04Z RAP AND 00Z NAM FORECAST
SOUNDINGS/. HOWEVER...A WARM NOSE CENTERED NEAR THE 800 MB LEVEL IS
EXPECTED TO RESULT IN AN INITIALLY MIXED P-TYPES. AS THE LARGE-SCALE
SYSTEM AND PRECEDING LOW-LEVEL JET SHIFT EWD...COOLING WITHIN THIS
LAYER SHOULD EVENTUALLY LEAD TO A TRANSITION TO ALL SNOW ACROSS A
CORRIDOR FROM THE NERN TX PANHANDLE INTO S-CNTRL KS...WITH RATES OF
1-1.5 INCH PER HR POSSIBLE. FARTHER S...THE WARM LAYER CENTERED NEAR
800 MB IS EXPECTED TO REMAIN MORE PRONOUNCED AND ABOVE
FREEZING...WHILE NEAR- TO SUB-FREEZING SFC TEMPERATURES MAY FAVOR
P-TYPES OF FREEZING RAIN AND/OR SLEET. CONVECTIVE ENHANCEMENT OF
PRECIPITATION RATES IS ALSO POSSIBLE GIVEN THE PRESENCE OF STEEP
MID-LEVEL LAPSE RATES AND ONGOING LIGHTNING S OF THE HIGHLIGHTED
AREA.

..ROGERS.. 02/21/2013

[venture]

Just about everyone is only a degree or two above freezing at this point. Dewpoints are right around 30 to 33 degrees over most areas too, so its going to be a close call for some areas to get major icing or just a cold rain.

[blangtang]

sounded like thunder, NW okc, pets hiding, lol! waking me up, suppose its a trial run for next few months...

as long as the elec doesn't go out...