Very cold air will surge southward across the state Saturday. A strong upper storm system will be approaching from the Southwest U.S.
This system will generate lift across the state starting very late on Saturday and continuing through the day Sunday. Most of the precipitation Sunday morning will be light, but with freezing temperatures in place, minor accumulations are expected to cause travel issues across a large part of the state.
Forecast soundings suggest a wide range of precipitation type across the state with freezing rain expected across the Southeast… a zone of sleet from Southwest to Northeast Oklahoma… and sleet becoming snow across the Northwest and Panhandle.
As the main system comes out Sunday afternoon, heavier snow is expected to develop from the Panhandle to West Central Oklahoma. This snow will spread northeastward during the afternoon and evening with some significant accumulations possible.
The other significant impact of this storm will be the extreme cold. Temperatures will likely drop to near record levels before the arctic air moves out next week. Sunday will be bitter cold with temperatures steadily falling into the teens and gusty north winds causing wind chills to drop below zero. By Monday morning, temperatures will likely drop below zero across a large part of Northwest and North Central Oklahoma, with single digit temperatures elsewhere. Monday will continue cold and then another night of bitter cold is likely into Tuesday morning when some temperatures across Northern Oklahoma will once again drop below zero.
Some light showers moved across Okarche early this morning and produced 0.08 of an inch of precipitation. This has brought the total for February up to 0.41 of an inch. This is only 25 percent of the average of 1.63 inches for the month.
We close the door on the meteorological winter (December, January, February) with 1.65 inches of precipitation. This is only 38 percent of the average of 4.32 inches for a winter. This ranks as the 4th driest winter on record.
There is excellent agreement among models this evening, somewhat surprising given a complicated forecast over the next several days.
A strong vortex will continue to spin over Southeastern Canada and the Great Lakes through the period. Pacific storms will train inland across the west coast and batter the Western U.S. ridge.
Cold high pressure currently over Oklahoma will shift eastward on Thursday as surface pressures fall over the High Plains. Winds will return to the southeast across the state and temperatures will warm nicely over the Panhandle. Across the remainder of the state, re-circulated cold air which has made it to the Gulf Coast will keep temperatures close to or slightly below normal.
The first wave to impact Oklahoma will be moving across the state on Friday. A well defined surface low will track eastward near the Red River. Lift associated with increasing low level warm air advection and the passing wave will be sufficient for a few showers and thunderstorms to form over portions of Central and Northeast Oklahoma early on Friday. Warm air / above normal / will spread eastward along and just north of the Red River. The remainder of the state will see temperatures held in check as cool air that wraps around the north side of the surface low, and cloudiness combine to keep highs below normal.
Cool air will slide southward across the state late Friday and early Saturday before the leading edge stalls near the Red River. This stall will occur in advance of the next storm system to approach the state Saturday and early Sunday. One of the more complicated parts of this forecast is the location of cold air on Saturday. 00z models suggest that the cold air will retreat slightly on Saturday, but this may be hard to get accomplished.
Very cold air will be surging south across the state on Sunday. Precipitation will break out over the Panhandle late Saturday, and across the remainder of the state early on Sunday. Snowfall amounts of 3 to 6 inches will be possible across the Panhandle. Forecast soundings suggest that precipitation over Northwest Oklahoma will transition from sleet to snow. Across Central and Northeast Oklahoma, precipitation that starts as freezing rain will change to sleet before ending. Some significant accumulation of sleet is possible over that part of Oklahoma northeast of Oklahoma City. Across South Central and Southeast Oklahoma, some significant accumulation of freezing rain will be possible.
With very cold air invading the state, most all of the precipitation on Sunday will fall as freezing or frozen precipitation, with little in the way of melting. There will be sufficient accumulations to cause hazardous travel conditions. Across parts of Central and Southeast Oklahoma, there may be sufficient accumulations of ice to cause power issues.
Thursday morning: 23
Friday morning: 34 / Showers
Saturday morning: 32
Sunday morning: 14 / Freezing rain and sleet
Sunday: 14 / Sleet and snow
Strong northwest flow will extend from Southwest Canada to the Ohio Valley at the start of the week. By mid-week, a ridge over the Western U.S. will amplify, while short wave troughs will be diving southeastward into the Eastern U.S. long wave trough.
Sunny skies allowed temperatures today to warm a little more than previously expected. Monday will see highs near seasonal normal as winds return to the south. Arctic air will start to make a southward push Monday night and Tuesday morning. This will filter into the state during the day Tuesday. Winds will be returning to the south again on Wednesday, but this won’t likely be in time to allow any significant modification to the cool air in place.
A weak southern branch short wave trough will be sliding across the Southern Plains from late Monday into early Tuesday. Most of the lift associated with this feature will be south of the Red River, but a few showers and thunderstorms will be possible across the southern sections of the state. Any precipitation across Central Oklahoma should be short-lived and light.
Monday morning: 29
Tuesday morning: 29
Wednesday morning: 23
As expected, winds became quite strong behind a cold front which passed across the state today. In Okarche, the peak gust was 55 mph. Most of the northwest half of the state saw gusts in excess of 50 mph and some locations saw winds over 60 mph. The highest gust was 67 mph at Goodwell. The highest gust in Central Oklahoma was 62 mph at Omega in Western Kingfisher County.
A very strong upper storm system is moving across the Plains today with 500mb winds in excess of 100 knots extending from New Mexico – across Oklahoma – to Missouri and Illinois. The atmosphere in advance of a cold front has become quite unstable today and numerous severe thunderstorms have developed from Illinois to Texas. As one would expect with a system of this strength, shear profiles favor rotating storms and there are currently several that are tornado warned over Northeast Arkansas/Southwest Tennessee/Northern Mississippi. A fairly strong circulation is approaching the southwest side of Memphis. Storms in Illinois have already produced tornadoes and images are rolling in of tornadoes with snow drifts in the foreground.
A strong upper system will move across the Plains tonight and early Thursday, reaching the Ohio Valley by Friday morning. As this system continues to lift northeastward, strong cyclonic flow will become established through the weekend from the Pacific Northwest to the Central Plains to New England. A sub-tropical jet segment will extend from Baja California to the Southern Plains and Southeast U.S.
There will be several weather changes across the state through the weekend. First up will be a strong cold front which will sweep across the state during the morning and early afternoon of Thursday. Very strong winds will occur behind this front with northwest gusts of 45 to 55 mph common, especially over Northwest Oklahoma. This wind will result in some areas of blowing dust through early afternoon.
Cooler air and lighter winds will settle across Oklahoma Thursday night and Friday morning. Pressures will fall quickly on Friday as southwest winds return, and high temperatures will end up above normal.
Another weak cold front will slip southward across Northwest Oklahoma early on Saturday. The effects of this front will be short-lived as south winds and warm air will prevail across the state during the afternoon.
By late Saturday, the front will again begin to advance southward across the state. This time, arctic air will help to drive the advance. This front will have cleared all but Southeast Oklahoma by daybreak on Sunday. Temperatures will have dropped below freezing over Northwest Oklahoma and the Panhandle. North winds will be gusting to between 30 and 35 mph. Sunday will be a cool day with temperatures below normal.
Thursday morning: 43
Friday morning: 34
Saturday morning: 38
Sunday morning: 33
A strong short wave trough is currently passing across the Pacific Northwest coast. This wave will amplify as it passes over the Plains on Thursday. In response to this system, deep surface low pressure will organize over Northwest Oklahoma which will move northeastward on Thursday. This will allow a cold front to surge across the state during the morning hours.
A very tight pressure gradient behind the front will result in very strong winds for several hours after the front passes. The strongest wind gusts may exceed 60 mph over Northwest Oklahoma. Peak gusts will decrease as the front moves east, but are still expected to reach near 45 mph across most of the state.
A small but strong short wave trough will move eastward across the Central Plains tonight and early Monday. A cold front associated with this wave will clear most of Oklahoma by sunrise. In the wake of the front, strong and gusty northwest winds will occur during the morning and afternoon. The air behind the front is not all that cold and highs will still range from the mid 50s to mid 60s.
High pressure behind the front will quickly move east of the state and winds will have returned to the southwest across Oklahoma by Tuesday morning. Temperatures will warm nicely across the state with highs ranging from the upper 60s to upper 70s. Another weak short wave will move across the Plains on Tuesday and this will drag another front across the state late in the day and during the early hours of Wednesday.
Once again, the cool air that moves in behind this front early Wednesday will be short lived as winds return to the south and temperatures warm into the 60s. Seasonably high low level moisture across the state will result in a moderately unstable atmosphere by late in the day. While a strong capping inversion will be in place to prevent surface based thunderstorms, it does appear that elevated showers and thunderstorms will form near or after sunset over Central Oklahoma. These will spread northeastward with increasing warm air advection during the late evening hours. It would not be out of the question that some of these storms could produce marginally severe hail, but no organized or widespread severe events are expected.
Monday morning: 49
Tuesday morning: 41
Wednesday morning: 41
Wednesday: 65 / Slight chance of showers and thunderstorms late
A strong short wave trough currently located just northwest of the Pacific Northwest, will move over the top of the Western U.S. ridge and then dive toward the Central Plains by early Friday. Another weak wave will move across the area late on Saturday, and then a stronger system will approach the Plains by late Sunday.
These waves will result in a couple of cold front passages through the weekend. The air behind each of these fronts will not be arctic in nature, resulting in only slight cool downs with mild conditions returning quickly.
There will be a few light showers over Northeast Oklahoma early on Friday, but the remainder of the state is expected to stay dry through Sunday.
Thursday will start chilly, with afternoon highs mostly in the 50′s. The first cold front will sweep quickly across the state during the morning hours of Friday. There will be gusty northwest winds behind the front, but temperatures will still make it into the 50′s. Above normal conditions are expected Saturday and Sunday with highs both days making it into the 60′s and 70′s across the state.
Thursday morning: 23
Friday morning: 35
Saturday morning: 36
Sunday morning: 39