General Weather Discussion - January and February 2017

[Bobby821]

What would that mean if the Low moved 30 miles north for us?

[Anonymous.]

The further the low travels to the north, the less cold air it is pulling down from the N and filtering it into OK.

18Z is the warmest it has been. We could even be near 60F on Saturday afternoon with heavy rain. The focus now will shift into late Thursday night into Friday where temperatures will be in the 28-33F range with freezing drizzle and freezing rain pockets developing. Travel problems won't be too likely, as the roads should hold the higher temperatures from the preceding days. NAM does indicate the I-44 corridor could be in the upper 20s all day Friday until around 9pm, when things begin warming up. Again, I feel elevated surfaces will be the main issue for any accumulation, then that will even eventually melt overnight heading into Saturday morning.

Moisture amounts will be in the 2-3" range, so a great drink for this dry winter.

[Bunty]

Meteorologist Aaron Tuttle's Ice Storm Recap for Friday:

FREEZING DRIZZLE WILL DEVELOP BY 6AM FRIDAY MORNING TRANSITIONING INTO LIGHT FREEZING RAIN DURING THE DAY AS TEMPS REMAIN BELOW FREEZING ACROSS C AND W OK. THE FREEZING LINE EXTENDS FROM TULSA TO OKC TO LAWTON. SATURDAY TEMPERATURES WARM ABOVE FREEZING AND THE PRECIPITATION WILL TRANSITION BACK INTO RAIN ACROSS C OK. RAIN WILL CONTINUE THROUGH SUNDAY. TOTAL ICE ACCUMULATIONS WILL VARY FROM 0.25 TO 1.0 INCH. ADDITIONAL RAIN TOTALS WILL TOP 2 TO 3 INCHES LATE SATURDAY AND SUNDAY.

[jn1780]

In the NWS discussion this morning, their thinking was that the freezing line will bisect the metro area. I think the main roads will be fine regardless except for bridges and overpasses unless the freezing line drifts further south and we get a degree or two cooler.

[SoonerDave]

In the NWS discussion this morning, their thinking was that the freezing line will bisect the metro area. I think the main roads will be fine regardless except for bridges and overpasses unless the freezing line drifts further south and we get a degree or two cooler.

I think that's the $64,000 question at this point, and the result is either a significant ice storm or just a cold rain. And I think the bottom line right now is that it's just impossible to call at this point. I've already made some changes for the rest of the week on the cautious notion that Friday could very easily go south. Not interested in playing the skating game.

[Bobby821]

Winter Storm Watch is out now until Sunday includes the Metro

[Bunty]

WINTER STORM WATCH
Areas Affected:
Alfalfa - Beckham - Blaine - Caddo - Canadian - Cleveland - Comanche - Custer - Dewey - Ellis - Garfield - Grady - Grant - Greer - Harmon - Harper - Jackson - Kay - Kingfisher - Kiowa - Lincoln - Logan - Major - McClain - Noble - Oklahoma - Payne - Pottawatomie - Roger Mills - Wa****a - Woods - Woodward
Effective: Wed, 1/11 10:03am Updated: Wed, 1/11 10:38am Urgency: Future
Expires: Sun, 1/15 6:00am Severity: Moderate Certainty: Possible

Details:

...WINTER STORM WATCH IN EFFECT FROM FRIDAY MORNING THROUGH LATE
SATURDAY NIGHT...
THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A WINTER STORM
WATCH...WHICH IS IN EFFECT FROM FRIDAY MORNING THROUGH LATE
SATURDAY NIGHT.
* TIMING...EARLY FRIDAY MORNING THROUGH EARLY SUNDAY
* ICE ACCUMULATION...ICE ACCUMULATIONS OVER ONE-QUARTER
INCH...ESPECIALLY ACROSS PART OF WESTERN AND NORTHERN OKLAHOMA
* WINDS...NORTH WIND 10 TO 15 MPH
* OTHER IMPACTS...ICE ACCUMULATIONS BY LATE FRIDAY INTO SATURDAY
MAY BE ENOUGH TO CAUSE POWER OUTAGES. BRIDGES AND OVERPASSES MAY
BECOME SLICK AND HAZARDOUS...ESPECIALLY ON FRIDAY.


Information:

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL. CONTINUE TO MONITOR THE
LATEST FORECASTS.

[Anonymous.]

GFS trending slightly colder temperatures, especially for Saturday. It was trying to warm the C parts of the state up well above freezing, but now is getting on board with NAM in suggestions it may only get to around 36-40F.

Event will begin with freezing rain/drizzle from about Lawton-Norman-W Tulsa early Friday morning in little waves. Then overnight Friday into Saturday AM, heavy freezing rain moves into NW OK, and C OK should begin warming to above freezing. If the freezing line moves further south and is stronger at the surface than forecast, it could be significantly worse in C OK, so the NWS has left the WSWatch going until Saturday night.

How deep the cold air spills into OK on Thursday night will really determine what will happen. I would say right now that extreme NW OK and up into Central to Western KS can bet on a significant ice storm.

[Easy180]

FWIW Oklahoma county ground temps are approaching the mid 50's

[jn1780]

The newest NWS graphics bumps up ice amounts slightly for the metro with the freezing line solidly through the metro area Friday. The freezing line moves north Saturday.

[OkiePoke]

My airline let me change to an earlier flight w/ no charge due to anticipated weather.

With the ground temps elevated, will that help with the freezing on the roads?

[Anonymous.]

The cold air is rushing in from the north right now, it is right on schedule with models. OKC should see temperatures begin dropping dramatically around midnight then fall to around 27-29F by sunrise. During the day we should recover to around 45F then be back to freezing around 11pm Thursday night.

The roads should hold their warmth, however, if temperatures get low enough at the surface, roads will freeze anyways. If we are near 32F, bridges will likely be the only issue. If we slip down near 25-27F, things could be hairy on all roadways. Again, this entire event's severity is hinging on handfuls of degrees.

So if you have somewhere to be, just wake up early on Friday and check the weather for updates, if it is 24 degrees and raining, then prepare for a bad time.

[judysue]

Mike Morgan on KFOR just said that OKC will be in the area receiving the most ice.

[OKCRT]

Mike Morgan on KFOR just said that OKC will be in the area receiving the most ice.

Yes more of these folks are starting to call for major ice storm in OKC. I guess colder weather moving in. Also they are saying Thursday evening start time.

[John1744]

[Anonymous.]

Need to wait for morning model runs, tonight's runs were all off in terms of current temperatures and front location.

That map posted above for Mike Morgan seems very flipped, unless he is expecting more sleet in NW OK (this would mean air is deeper, colder, and further south than anticipated by models). NW OK into KS could likely see a historical ice storm. It is also worth noting that his map is only ranging .25 to .75 of ice in his white region, which is significant, but not ridiculous by any means.

[SoonerDave]

Need to wait for morning model runs, tonight's runs were all off in terms of current temperatures and front location.

That map posted above for Mike Morgan seems very flipped, unless he is expecting more sleet in NW OK (this would mean air is deeper, colder, and further south than anticipated by models). NW OK into KS could likely see a historical ice storm. It is also worth noting that his map is only ranging .25 to .75 of ice in his white region, which is significant, but not ridiculous by any means.

Jed Castles on Ch 9 this morning was saying that the air coming in was colder than the models had predicted, apparently by roughly 5 degrees, and possibly a bit further south, both of which tended to increase the ice potential. I also noted that the area of greatest potential on his maps had also moved perhaps 30-40 miles east and south. To give you an idea of how narrow this change is, and just how hard all of this is to call, the previous map had our immediate area *just* south and east of the higher impact area. Now we're in the middle of it. And given the variability of these models, a delta of 30-50 miles would seem to be well within the range of variability...

[riflesforwatie]

Jed Castles on Ch 9 this morning was saying that the air coming in was colder than the models had predicted, apparently by roughly 5 degrees, and possibly a bit further south, both of which tended to increase the ice potential. I also noted that the area of greatest potential on his maps had also moved perhaps 30-40 miles east and south. To give you an idea of how narrow this change is, and just how hard all of this is to call, the previous map had our immediate area *just* south and east of the higher impact area. Now we're in the middle of it. And given the variability of these models, a delta of 30-50 miles would seem to be well within the range of variability...

That's about right. At 15z/9 am local, the freezing line is a county or so (not a ton) further south and east of where f003 from the 12z runs has it and sfc temps are running between 3 and 5 deg F colder than f003 from 12z runs. It's important to note that we are progged to go well above freezing in central Oklahoma this afternoon, so just because we're colder than expected right now doesn't mean we will continue to be into tonight and early Friday morning.

Also, the trend in the forecast position of the 32f sfc isotherm has leveled out in the last 2-3 runs of some of the guidance. Unfortunately it is progged to sit right along the I-44 corridor (give or take tens of miles), which results in a situation for the OKC metro that is still basically "clear as mud", with the 32f line waffling across the metro Friday into Saturday midday.

[LocoAko]

KFOR even posted a "worst case scenario" map (though no such labeling was done on the graphic) that gave OKC 0.9" of ice. I see nothing in the data to support that currently, but props to him if he scores a coup on it. The temperatures are the big thing to watch, of course, but the increasingly cold trend on some of the models (NAM, SREF) has stopped and if anything the QPF -- though notoriously inaccurate -- has been decreasing some. I'm not really expecting OKC (downtown) to get more than 0.3" of ice, but I guess we'll see.

[TU 'cane]

I watched Aaron Tuttle's broadcast from last night. I enjoy his take on things. But he mentioned something that I didn't consider: stay away from power lines and tall structures when the ice starts accumulating!

Hope everyone is prepared and stay safe all.

[Anonymous.]

Even HRRR is running about 3-4F warmer than actuals. But like riflesforwatie said, tonight's temperatures is what really matters. It is interesting to see the nearly stalled out front down in SE OK right now, fighting as hard as it can against the warm air riding up against it.

It will also be important to monitor dewpoint and wetbulb overnight, as well as cloud cover thickness. A lot to watch as we head into tonight.

12Z GFS loading in as I post this, and it is coming in 2-3F colder than 06Z. We will have to see if this trend continues as it could suggest a longer time frame where accumulation would be feasible.

[TheTravellers]

I watched Aaron Tuttle's broadcast from last night. I enjoy his take on things. But he mentioned something that I didn't consider: stay away from power lines and tall structures when the ice starts accumulating!

Hope everyone is prepared and stay safe all.

Good point about power lines and tall structures - when we lived in Chicagoland, everybody knew this and all the buildings had signs about falling ice/snow and you couldn't even walk past certain buildings sometimes, but here in OK, it's rarer and we have less tall bldgs, so folks might not think about it.

[Of Sound Mind]

[Anonymous.]

Likely to see conversions to Ice Storm Warnings soon for pretty much entire Norman NWS area.

[kbsooner]

Likely to see conversions to Ice Storm Warnings soon for pretty much entire Norman NWS area.

So conditions are degrading? Pretty much a guarantee for OKC then?