General Weather Discussion - January/February 2015

[venture]

Through Thursday main impacts will be to SC OK and SE OK. Freezing drizzle, sleet, and some light snow main impacts.

Friday is when the main storm system pushing into. 06Z NAM has a band of moderate to heavy precip run along I-44 from SW to NE OK. For the Metro proper...

By Noon Friday main push of precip will enter the Metro area. Up to 0.15" of precip possible. NAM has upper air profiles favorable for a Sleet/Freezing Rain miz with surface temps remaining below freezing. Through 3PM light precip will continue over far SE Metro areas and heavier precip over NW sections of the metro area. Upper air profiles will be borderline but a slight more favorable towards freezing rain, sleet, and snow. If NAM would verify, I would expect the outside possibility of Winter Storm or Ice Storm warnings for area from Stillwater to El Reno to Anadarko.

Moving through Friday, the main precip band will continue to push NW a bit. Temps with the forecast sounding profile in Norman still indicate icing conditions with sleet mixing. By 9PM precip will increase again over the Metro area with an additional 0.15" to 0.35" of precip possible. Temp profile is slight warmer but surface temps could still be at or just below freezing. By Midnight, the surface temp is critical as significant icing could take place with 0.35" to 0.5" over 3 hours during this time period. Through 6AM Saturday precip will finally start to shove east some. Another 0.15" to 0.25" of precip possible. Upper air temps look to favor more sleet/snow during this time period.

00Z Operational GFS isn't much different. It has the precip band on the east side of the Metro versus mostly on the west. Temp profiles are slightly colder as well for each time period.

Needless to say...late Thursday through early Saturday could be a pretty big deal around here. Keep an eye on the temps as we will be a degree or two away from a major winter storm or a very cold rain.

[venture]

For today only...

URGENT - WINTER WEATHER MESSAGE...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
341 AM CST THU JAN 1 2015


OKZ021>031-033>035-011745-
/O.EXB.KOUN.WW.Y.0016.000000T0000Z-150102T0000Z/
BECKHAM-WA****A-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-
CLEVELAND-POTTAWATOMIE-SEMINOLE-HARMON-GREER-KIOWA-
INCLUDING THE CITIES OF...ELK CITY...SAYRE...CORDELL...ANADARKO...
YUKON...EL RENO...MUSTANG...OKLAHOMA CITY...CHANDLER...
CHICKASHA...PURCELL...NORMAN...MOORE...SHAWNEE...S EMINOLE...
HOLLIS...MANGUM...HOBART
341 AM CST THU JAN 1 2015


...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM CST THIS
EVENING...


THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER
WEATHER ADVISORY FOR FREEZING DRIZZLE AND LIGHT FREEZING
RAIN...WHICH IS IN EFFECT UNTIL 6 PM CST THIS EVENING.


* TIMING: PATCHY SNOW FLURRIES AND FREEZING DRIZZLE WILL BECOME
WIDESPREAD THROUGH THE MORNING HOURS...CHANGING TO FREEZING
DRIZZLE AND BRIEF LIGHT FREEZING RAIN SHOWERS THIS AFTERNOON.


* MAIN IMPACT: VERY LIGHT GLAZING OF ICE ON ELEVATED SURFACES IS
EXPECTED WHICH WILL CREATE SLICK SPOTS ON BRIDGES AND
OVERPASSES.


* OTHER IMPACTS: SLICK SPOTS MAY ALSO DEVELOP ON SIDEWALKS AND
PARKING LOTS.

[venture]

06Z GFS is aligned pretty well with the 06Z NAM. I would imagine OUN will let the Winter Wx Adv for today play out before doing the next set of headlines to avoid confusion.

[John1744]

A couple local TV mets are seeing what Venture is as well, looks like tomorrow if the models play out could get really ugly in our area.

[Tydude]

KOCO 5 is saying that the new models is saying that OKC metro could get alot of freezing rain which could get ugly here in OKC

[Anonymous.]

NAM and GFS pretty much both agree that a train of precip is going to be draped over I-44 corridor for a pretty long duration. Same time, the warm nose on the north-end will be trying to push west.

Think of it as a very large scale letter "S". The top half is warm moist air trying to push northwest, the bottom half is the colder, dryer air trying to fill in to the southeast. Now depending how much of this warm air mixes into the already-in-place cold air at the surface, we could just see an extremely cold rain and some vegetation icing. Also the rate at which precip is falling will come into the temperature equation (Remember last early December when we were under ice storm warnings, but the rain fell so fast that it actually warmed the shallow air at the surface enough to not cause huge issues).

Also models are trending at the wrap-around being more close-knit to the main precip shield. This could result in the potential for snow banding to be closer to the main body of OK as opposed to NW/N areas of the state.

Right now I would say SW and WC OK look to be money spot for ice-storm - followed up by getting hit with wrap-around sleet/snow.

Here in OKC, it is a tough call, going to have to play it by hour as we watch temperature behavior and the precip move in.

[s00nr1]

[John1744]

NWS just revised their thinking a bit, local TV mets seem to be learning a bit heavier on ice in central OK but that rain band is pretty close.

[venture]

18Z NAM Update...

Main wave of precip will get into the metro between noon and 3PM tomorrow. Looks like about 0.15" to 0.25" of precip by then. Forecast sounding has surface temps at like 33°F. Through the rest of the day on Friday and into the overnight, temps are almost completely stationary and remain that way through Saturday morning.

This could lead to major icing concerns if we get this precip forecast...

[Easy180]

Have co workers that will be out in this mess tomorrow. If that forecast holds true would the icing be mostly bridges etc since it is slightly above freezing?

[venture]

Have co workers that will be out in this mess tomorrow. If that forecast holds true would the icing be mostly bridges etc since it is slightly above freezing?

With us being below freezing for an extended period of time, it'll take a bit for the pavement to warm up.

[venture]

New Advisory for the SW 1/4 of OK to cover the next system....

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NORMAN OK
342 PM CST THU JAN 1 2015


OKZ023-027-038-039-044-045-TXZ086-089-090-021200-
/O.CAN.KOUN.WW.Y.0016.000000T0000Z-150102T0000Z/
/O.NEW.KOUN.WW.Y.0017.150102T0800Z-150103T0600Z/
CADDO-GRADY-COMANCHE-STEPHENS-COTTON-JEFFERSON-WICHITA-ARCHER-
CLAY-
INCLUDING THE CITIES OF...ANADARKO...CHICKASHA...LAWTON...
DUNCAN...WALTERS...WAURIKA...WICHITA FALLS...ARCHER CITY...
HOLLIDAY...LAKESIDE CITY...HENRIETTA
342 PM CST THU JAN 1 2015


...WINTER WEATHER ADVISORY IN EFFECT FROM 2 AM FRIDAY TO MIDNIGHT
CST FRIDAY NIGHT...


THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER
WEATHER ADVISORY FOR FREEZING RAIN...WHICH IS IN EFFECT FROM 2 AM
FRIDAY TO MIDNIGHT CST FRIDAY NIGHT.


* TIMING: FROM EARLY FRIDAY MORNING THROUGH FRIDAY NIGHT.


* MAIN IMPACT: LIGHT TO MODERATE FREEZING RAIN MAY RESULT IN ICE
ACCUMULATIONS OF UP TO A QUARTER INCH ON TREES...POWER
LINES...AND OTHER ELEVATED SURFACES.


* OTHER IMPACTS: LIGHT ICING MAY OCCUR ON BRIDGES...OVERPASSES...AND
OTHER EXPOSED ROADWAYS...RESULTING IN HAZARDOUS DRIVING
CONDITIONS IN SOME AREAS.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

[LocoAko]

Glanced at the 15Z SREF plumes for Norman and OKC and almost all runs seem clear on turning both over to rain.. Which is lucky for us, since the total rainfall for tomorrow's system comes out to around 0.65". (Mean) temperatures rise above the freezing level around 15Z tomorrow morning and stay there, though there are some warm outliers and a few runs would definitely still create icing problems on bridges, etc. Just FWIW.

[Anonymous.]

Yea it's looking like cold rain event. Warmer air is mixing into the surface ahead of the storm much too quickly.

That in combination with the main precip. shield hitting us at daytime peak-heating is recipe for rain. NW TX looks like they could get a decent ice storm.

[venture]

Yeah ideally we start a bit warmer here and remain above freezing. That's my expectation, but I also remember how many of these setups where it has been a degree or two difference and we just need to keep open to the possibility. Today getting into the low 30s around here should help. We'll see what temps do tonight.

[s00nr1]

Going to be very close. Drizzle starting right now here in the metro should help keep temps up a bit overnight.

[venture]

Going to be very close. Drizzle starting right now here in the metro should help keep temps up a bit overnight.

I would not be shocked if the western Metro (Yukon, El Reno, etc) get a pretty decent icing event and the eastern Metro (Shawnee, Norman, etc) get nothing but a cold rain.

[s00nr1]

I would not be shocked if the western Metro (Yukon, El Reno, etc) get a pretty decent icing event and the eastern Metro (Shawnee, Norman, etc) get nothing but a cold rain.

Heavy drizzle right now on the east side of Moore but at this point is not icing on concrete surfaces....only wet.

[LocoAko]

Heavy drizzle right now on the east side of Moore but at this point is not icing on concrete surfaces....only wet.

Same in central Norman. Certainly makes me cautious though since we are hovering right at 32F.

[yukong]

DPS is suspending all non essential services in Comanche, Cotton, Jefferson, Stephens, Caddo and Grady Counties tomorrow.

[venture]

Winter Wx Adv now up for the rest of the Metro for freezing drizzle/freezing fog overnight. Temps have dropped a degree or two more below freezing.

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NORMAN OK
1215 AM CST FRI JAN 2 2015

OKZ008-013-018>020-024>026-028>030-021300-
/O.EXB.KOUN.WW.Y.0017.150102T0615Z-150102T1300Z/
KAY-NOBLE-KINGFISHER-LOGAN-PAYNE-CANADIAN-OKLAHOMA-LINCOLN-
MCCLAIN-CLEVELAND-POTTAWATOMIE-
INCLUDING THE CITIES OF...PONCA CITY...PERRY...KINGFISHER...
GUTHRIE...STILLWATER...YUKON...EL RENO...MUSTANG...
OKLAHOMA CITY...CHANDLER...PURCELL...NORMAN...MOORE...SHAWN EE
1215 AM CST FRI JAN 2 2015

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 7 AM CST THIS
MORNING...

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER
WEATHER ADVISORY FOR LIGHT FREEZING DRIZZLE AND LIGHT FREEZING
RAIN...WHICH IS IN EFFECT UNTIL 7 AM CST THIS MORNING.

* TIMING: THROUGH AT LEAST 7 AM FRIDAY. THERE IS A CHANCE LIGHT
FREEZING RAIN AND LIGHT FREEZING DRIZZLE CONTINUES PAST 7 AM
FRIDAY.

* MAIN IMPACT: LIGHT FREEZING RAIN AND LIGHT FREEZING DRIZZLE WILL
RESULT IN ICE ACCUMULATIONS OF UP TO ONE TENTH OF AN INCH
THROUGH 7 AM FRIDAY ON TREES...POWER LINES...AND OTHER ELEVATED
SURFACES.

* OTHER IMPACTS: LIGHT ICING MAY OCCUR ON BRIDGES...OVERPASSES...
AND OTHER EXPOSED ROADWAYS...RESULTING IN HAZARDOUS DRIVING
CONDITIONS IN SOME AREAS.

[Bobby821]

Ice Storm Warning now in effect for metro area until 6:00 AM Saturday

[Bobby821]

It is now starting to get Icy where I live in Moore, here is the latest weather briefing from NWS in Norman. https://www.youtube.com/watch?v=-LvLI5zNHRE

[jn1780]

The freezing line is approaching the I-35 corridor. We could see the NWS trim some of the eastern counties off the Ice Storm warning area later in this morning/ early afternoon.

[Bobby821]

The freezing line is approaching the I-35 corridor. We could see the NWS trim some of the eastern counties off the Ice Storm warning area later in this morning/ early afternoon.

I doubt they will do that