A large area of cold high pressure continues to build towards the Ohio Valley today on the heels of that very impressive early December storm that brough blizzard conditions to areas to our north, severe weather and tornadoes to areas to our south, with rain, gusty winds, and dropping temperatures around here.
This high will dominate the weather pattern for the next 24 to 36 hours. As a result, very cold temperatures will continue across the region through Friday.
Heading into the weekend, the high moves east and the upper level pattern will deamplify allowing for milder, pacific air to spread into the Ohio Valley.
Notice how today's H5 chart shows the strong polar stream dipping into the Ohio Valley...
By Sunday, huge changes! Polar jet retreats north, flow becomes more zonal in nature with the subtropical jet dominating our weather by then...
If you look closely at the above H5 heights/vort chart valid 12z Sunday, you can see a couple of weak disturbances flowing through the sub tropical stream. One located over the Iowa/Missouri region and a stronger one moving into California. These disturbances will bring us chances for mainly light precip. The first chance comes Saturday night into Sunday morning with another chance during the Monday night / Tuesday timeframe.
What type of precip you ask ?? Rain ! No snow at all over the next 5 day or so. As the afore mentioned pattern change takes place, H85 temps will warm well above critical. Muchh of the guidance has 850 temps on the order of +6 to +10 C !! This will allow for surface temps to easily warm into the 40s with perhaps even some 50s on the horizon.
Looking ahead... really doesn't look all that cold - at all !! Actually there's a decent chance we may see some pretty mild/warm temperatures heading into Christmas week.
Here are the 216 and 240hr ECM charts at H500.
Nothing cold or snowy on these charts for us - at all !!!
Even the current MJO chart shows the recent activity weakening and moving towards the neutral circle - an indication that our current cold / amplified pattern is about ready to break down and the extended ECM charts above certainly support that idea.
Take care all,
Jay
2 comments:
Jay, This is an El Nino year simular to 1994. Since most of systems will be riding along the Southern Jet, what are the chances that we could repeat 15.9 inches in a 24 hour period in 2010.
Hi Rob, sorry for the delay !! Spending time with the family this past weekend. So far, the upper flow has been very amplified and quite changeable. Actually, I would say that chances are fairly decent for some kind of major winter event (including ice) in this kind of a pattern. As you mentioned the southern (STJ) is quite active and the PJ the same. The pattern is getting close to producing something big ! Later this week a block will be forming in the east forcing any Pacific systems to take the southern route - the only Qs is how strong will these Pacific systems be and will they be forced to go too far south ? Time will tell but yes sir ... I agree that in this "kind" of a set up, chances are pretty decent that a major winter event looks pretty promising. See you my friend
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