Thursday Morning Update

The focus of the forecast revolves around a strong Sunday cold front, storms chances, and cooler air Monday.  A few short term issues involve an increasing fire danger this afternoon and a small chance of a few storms pre-dawn Friday into the afternoon across far NE OK and SE Kansas. 

Temps are very mild this morning with south winds keeping readings in the 50s.  We'll reach the lower to mid-80s this afternoon along with mostly sunny conditions and southwest winds at 15 to 30 mph.  RH values this afternoon may drop back down into the 20-30% range and the fire spread index will be increasing.  If a wild fire or grass fire begins, weather conditions would support a rapid spread.  The simple solution is to not burn and also make every effort to not create any "sparks" that could ignite a fire. 

The pattern will support a weak boundary sagging into northern OK later this afternoon and evening.  This cold front may pass the Tulsa metro before stalling north of the I-40 corridor later tonight.  No thunderstorms are expected along the boundary as it approaches the state this afternoon.  

Pre-dawn Friday into the afternoon, the next short wave aloft will be sliding across the Rockies into the central plains.  The pressure will quickly fall to our west and the boundary will begin lifting northward as a warm front.  Some short term data suggest a few isolated storms will be possible as the process occurs.  The better chance will end up in southeastern and eastern Kansas, but we may see one or two storms fire up near or northeast of Tulsa pre-dawn Friday into the midday period.  If this happens, storms could produce some hail.  The actual chance will remain near 20%.  I'll probably place this pop on the map for the 7 day planner. 

Friday the east and southeast winds return with highs in the upper 70s or lower 80s. 

The main forecast challenge for the weekend involves the timing of the Sunday system and whether or not we'll see any severe storms.  The system is a phasing of two waves.  The northern stream and southern stream both have disturbances that will be moving into our area.  As this happens a cold front will move across the state Sunday and thunderstorms will develop.  At this point, most surface based CAPE and instability will be suppressed to our west and southwest Sunday.  The actual positioning of the surface features may also limit the severe weather threat, but the confidence remains low, even at this hour.  So, here's the plan:  The pops will remain at 70% for the event.  We'll mention a chance for a few strong storms, with maybe one or two severe storms, but will refrain from any other statements at this point in the forecast cycle.  

As stated here for the past few days, I think the air mass following this frontal passage will be very cold for a large portion of he Midwest and upper Midwest.  Temps may drop into the 30s and 40s for daytime highs in places like Chicago northward.  The computer model suggestions are now trending slightly warmer for Tulsa Monday afternoon with highs around 60.  I think this may be incorrect.  We'll keep the highs in the upper 50s at this point.   

Tuesday morning if the clouds clear out, this will set the stage for a light freeze or frost near and northeast of Tulsa.  This type of a late event could require a freeze or frost warning from our friends at NWS.  We'll keep you posted. 

The official high in Tulsa yesterday was 79 recorded at 4:55pm.

The normal daily average high is 70 and the low 47.

Daily records include a high of 92 from 1927  and a low of 31 from 2003, 1973, and 1952. 

You'll find me on Facebook and Twitter. 

I'll be discussing the forecast on numerous Radio Oklahoma News Network affiliates across the state this morning. 

You'll hear the forecast on Tulsa's Clear Channel Radio stations including the great KMOD and The Twister, and many others.  

Have a super great day!

Alan Crone

KOTV