A Nice Warm-Up Before Winter Returns

The potential remains for a significant icing event across part of the state Friday through at least Saturday morning to midday, along and north-northwest-west of the I-44 corridor region.  Locations to the southeast of this line, more so across east-central and southeastern OK, will be in the running for pockets of moderate to heavy rainfall this weekend.   Before we see the cold air and precipitation unfolding, more spring like weather will remain today and Wednesday with increasing temperatures and fire danger across the state.  

Temps this morning will start in the 50s along with south winds around 25 mph.   The wind speeds have remained strong overnight but should begin to drop down into the 10 to 15 mph range by midday.   A weak disturbance will pass the state this morning and a few spots of drizzle or spotty showers may occur across far eastern OK into western Arkansas but the odds remain very low.

Later today, a weak wind shift (front) will enter the state and move across at least part of eastern OK this evening before stalling and lifting northward with more south winds and warm air Wednesday.   High temperatures today will move back into the upper 60s near 70 with a sun-cloud mix.   The fire danger will be elevated today.

Wednesday, south to southwest winds will return in the 15 to 25 mph range and temperatures will warm from the 50s for the morning hours into the lower 70s across eastern OK by the afternoon.   Our neighbors across the western third of the state may see upper70s Wednesday with a few spots hitting 80 across far southwestern OK.   But by Wednesday night into Thursday morning, the party is over and another arctic front will roll into the state.   As this front sinks southward, a few storms may occur late Thursday night into pre-dawn Friday across far southeastern OK and western Arkansas.   This will be south of the metro.   But as the cold air races into the state, temps will start in the upper 30s near 40 Thursday morning, possibly move into the mid-40s by Thursday afternoon and dropping to near freezing Friday morning.  Drizzle and low clouds may attempt to form Friday morning and could become a travel issue to the northwest of the metro as temps will be near or slightly below freezing.  

By Friday afternoon and evening, the arctic front will be stalling near or slightly southeast of the I-44 corridor region.   This means locations along the corridor to the northwest and west will be near or below freezing while locations to the southeast will remain above freezing.   The data remains inconclusive at this hour for a high confidence on the exact location of this freezing zone, but the least likely area will be across southeastern and east-central OK. This location will more than likely stay in the rain zone for this entire event and have no chance of icing or any wintry weather impacts.   Data does suggest the presence of unseasonably high moisture availability for January and pockets of moderate to heavy rainfall will be possible that may lead to some localized flooding issues in low lying areas across the southeastern and eastern sections.  Locations near the metro, on both sides of the I-corridor may be in the freezing zone Friday into Saturday morning.    Locations to the west and northwest of the metro will have a much high likelihood of an icing event but the data remain inconclusive regarding some important aspects of the set up.

We do know this pattern will support a major icing event across part of the state.   A shallow arctic air mass will be in place across part of the region, a pronounced warm layer of air will be present above this cold shallow dome of air, favorable low and mid-level jet flow will be likely to bring abundant moisture into the state, and the duration of the event could lead to some issues ranging from travel impacts to power outages.   There are a few limiting factors for a major winter event for the Tulsa metro, including the lack of a second surge of cold air Saturday that would allow the freezing zone to move south and southeast.   The last few runs of the GFS continue to support this zone with the 32-degree line to be located to our northwest and west for most of the event.   The EURO data is colder and slightly more south and east with this zone.   Such discrepancies are normal with the handling of a shallow air mass in the GFS and we have continued to use a blend of the EURO and GFS for the temperature forecast from Friday through the weekend.   This means we will continue to mention and include the Tulsa metro for some icing impacts, possibly significant, Friday through the Saturday.   We must stress that additional changes to the forecast will be likely and you should remain aware of the weather through the end of the week.  For example, the latest run of the GFS is now hinting at a warm air convection pattern occurring Sunday morning to midday with a robust warm-up as an area of low pressure lifts across Texas into part of the state.  The EURO is now also sending signals of this potential for Sunday.   Not only would this end the threat of freezing rain for the area Sunday, but it would bring the threat of strong heavy to strong storms into the eastern OK area by Sunday midday to afternoon.   We have brought the temps up for Sunday slightly, but have kept the morning hours near freezing.   Again, additional changes to the weekend forecast are likely.  

In summary, the cold air will arrive Thursday but freezing temperatures are not likely until Friday morning near the Tulsa metro.   The threat for some freezing drizzle may occur Friday morning but the chances for freezing rain would begin in earnest Friday night and continue through Saturday morning and then again late Saturday night into Sunday morning.   By Sunday midday to afternoon, temps should be well above freezing.  At this point, there will be no chance in our forecast for freezing rain for southeastern or east-central.   Again, data may change and require us to change this forecast and residents of southeastern and east central OK should also remain aware of this weekend system.

Thanks for reading the Tuesday morning weather discussion and blog.

Have a super great day!

Alan Crone
KOTV