Friday Morning Update

Friday, June 22nd 2012, 5:13 am
By: Alan Crone

Patchy morning fog will continue through early morning followed by sunny and warmer weather this afternoon with highs near 90.  We're still forecasting hot conditions by this weekend into early next week.

The rainfall yesterday morning across extreme northeastern OK was very beneficial.  Some locations received from 1.5 to near 2 inches of rain while areas near northern Tulsa County measured about .40 inches of precipitation.  The southern portion of Tulsa County and many areas south of Tulsa received only a trace of precipitation.  There may be one or two rogue thunderstorms today across extreme eastern or southeastern OK, but I will not include this slight probability in the 7 day planner graphic package for the morning broadcast.  Unfortunately, we are moving into a pattern that will bring the hottest readings we've seen since last summer to our area.  

All model data support the mid-level ridge building across the state this weekend into early next week.  What is not clear is the exact thermal structure of the atmosphere.  The GFS has consistently been in the "not as hot" category compared to the EURO and the NAM extension.  A disclaimer:  I typically do not study the NAM extension on a day to day basis, but do look at the EURO every day.  The EURO 850 temp plots are very warm by the middle of next week with the data suggesting 26 to near 28c around the 5K ft level which would normally translate to very hot temperatures at the surface, anywhere from 102 to 105.  The big issue is the role of ground moisture, the recent rainfall, and the impact of the green vegetation.  If our ground cover was mainly brown instead of green the temps would soar next week to record levels, but the impact of evapotranspiration may act to off-set the highs a few degrees.  In other words, this forecast of mainly "temperatures" doesn't appear as easy as one would imagine with a 594 MB ridge building into the area.   

There will be a weak back door front arriving either Monday or Monday evening across Eastern OK.  GFS and EURO data both support this boundary entering northern OK but very little change in sensible weather will be noticed.

Another issue to ponder is the possible formation of a tropical low pressure system in the Gulf of Mexico.  Certain models and certain model runs have been indicating this formation which would act to limit the northward spread of typical late June dew point temperatures into the southern plains.  At first glance, this would be a good thing by limiting the potential heat index problem with the forecasted highs above 100.  At second thought, this could also allow for air temps to go up a degree or two as dry air heats more efficiently than moist air.  Regardless, we have chosen to go with the high end of the temperatures for early next week and this means triple digit weather in the forecast.  If we don't hit the actual numbers, we're going to take a lot "of heat" for missing the mark (pun intended) but if we don't hit the exact numbers, the temperature heat index values will come very close.  

The pattern may very well keep the ridge to close to our area for any significant chance of showers or storms next week, but I would imagine this ridge will slowly morph or move westward by Thursday or Friday creating a small window of northwest flow aloft over the NE OK-SE Kansas vicinity.  This would open the highway for a few late night and early morning storms to brush the extreme NE Ok area, but most of us would still miss out.  Bottom line: hot and dry next week.


Regarding the tropical system in the Gulf; 

The hurricane hunter aircraft will take a flight into the area this afternoon to investigate the storm for any signs of intensification and basically to check it out.  The data recovered by the flight will be quickly sent back to the NHC where it will be analyzed by some of the smartest weather brains in the world.  I'll try to keep you posted regarding the possible evolution of this system.


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