Arctic Air Soon

Morning clouds will give way to partly to mostly sunny conditions this afternoon with highs in the mid-40s.  A strong arctic front arrives tonight with the coldest air of the season this weekend.

The clouds will begin thinning today with a period of sunshine before the arctic boundary moves across the area this afternoon with gusty northwest winds at 15 to 25 mph.  This boundary will bring much colder air to the region tonight with the coldest air of the season for the weekend.  The data continues to trend colder with each run for the Saturday time period as the ridge of high pressure centers across the central U.S. and builds southward.  The influence across our area will include gusty north winds tonight and Saturday with very cold air moving into the area.  Morning lows Saturday and Sunday will be in the lower teens with highs Saturday near 30.  Sunday the ridge begins to move slowly eastward as the next upper level system approaches from our west.  This will cause the surface winds to back from the southeast Sunday afternoon as highs move into the upper 30s or lower 40s. 

The Sunday evening and Monday forecast is a difficult challenge as EURO, GFS, and NAM data suggest a southerly surface wind across the area as precip begins to develop.  These south winds will begin to bring slightly warmer air back to the region but the temperatures in the profile may be near freezing for a few hours Monday morning before they move into the upper 30s Monday midday.  This would create a favorable window for some wintry precipitation in the form of a sleet and snow mixture.  The timing of the system would occur during the Monday morning commuting hours and some travel issues would be a possibility for portions of northern OK.  These data will no doubt change a little between now and Sunday night and we encourage you to check back often for updates.  This system, as currently modeled, would not be considered a major winter storm, but could provide for some travel issues for a few hours.

Some specifics from the latest suite of model data:

Saturday afternoon temps at 850mb may be in the -10c to -12 range across Northern OK and southern Kansas.

00GFS supports 850 freezing line near the 412 corridor with the 540 DM line still located near Northern OK by noon Monday.

The EURO also has the 850 freezing line near the Tulsa area but takes the 540DM area slightly northward by Monday midday.

Buf profiles indicate about a window from around 11pm Sunday to noon Monday for winter precipitation across northern OK.  Model outputs from the various options do not produce significant amounts of precipitation.

Models have a very difficult time when dealing with shallow arctic air.  Changes to the forecast will be possible.

The Monday afternoon through Wednesday time period will feature warmer air along with south winds allowing for temperatures to move near and above the seasonal average.  Another system will arrive Wednesday, but the temperature profile could keep this event all liquid with some thunder possibilities.