Taking a look into later October and early November!

Going to take a look at what the forecast model are showing for the latter half of October into early November. We'll start off with the GFS Ensemble mean 2 meter surface temps (or what we would feel in terms of warmth of chill) 

This is from Oct 25- Nov 1st. The GFS (US model) ensembles show more warmth (compared to normal this time of year) over much of the eastern US (excluding the upper Mid West) This is due to ridging building over the central US 

With the ridging over Alaska that would imply more Surface Highs which in time will bring much colder temps into the North tier of the US which is what we see in the GFS ensembles (first image) We also take a look at the European model (which does pretty well in the long range) it too is in agreement with the GFS for the most part. 

While I can't show the surface temp departures like the GFS above, we can get an idea of where the warm weather will be by looking at the next image (850 *5000ft* temps) or low level temps from the Euro model

This as well is inline with the GFS that the latter half of October should be mild for many in the east (though the North East and NW Pac will remain cooler than the central southern US) The Canadian model is a bit warmer than both the GFS and EC in this time frame 

With all this in mind I believe we will see some Indian summer like weather on the way with temps in the central and Southern US (more so southern Plains) with temps around 80 and so 90s possible in parts of TX. Looking even further down the road last day or two of October into first few days into Nov we can see on the GFS and CFS (Climate Forecast system weekly) that cooler air may settle in! 

Also the weekly forecast from the CFS is showing cooler air to move in replacing the warmth

This model (CFS) has done pretty well in the longer range and with ridging starting to show up around Alaska later in the time frame its only a matter of time before much colder air moves into the US! 

Large storm to take shape over Mid Western/Eastern US

A large and powerful fall storm is forecast to take shape in the upper Mid West and move slowly east. 

We see the beginnings of this over Montana and into the Dakotas (area of clouds) Jet stream analysis shows the powerful Jet entering the Pacific North West. 

This image shows mean sea level pressure with the main low over Saskatchewan Canada. We look at the short term forecast models for how this system may unfold. Here is what the NAM model shows 24hrs from 2pm October 16 

This powerful Jet streak in the Pac NW is forecast to deepen the Low in southern Canada while sending a cold front plowing east. (also the NAM 48hr forecast)

Though this model puts out rain in the South East, there is some large differences with some other models on just how much if any rain affects North Carolina. Here is what the Official forecast from the HPC 

Warm for the rest of the week, turning much cooler by early next week!

Last few days have felt warm and a bit humid (almost late August than early October) while the air will dry in the coming days (though warmth will stay around with temps in the low 80s) By this weekend will a large change in temperatures are forecast. Looking at our forecast model (GFS/ US model) 

Mild temps out ahead of the next front that will really knock temps back.

Both models are valid Monday Oct 8th. All thanks to a large trough setting up over eastern North America.

There are still signs from the longer range more reliable European model as well for cooler temps in the east

Beyond this I expect a warmer/mild pattern as we head into later October with Halloween possibly being mild for the South East? we'll see.

Chance of severe storms later (low chance)

Most of NC is locked in a cool wedge air mass today as a weak surface high over the Great Lakes ridges down the eastern side of the Mountains and a storm systems moves in from the west/south west. 

With that comes clouds and rain 

Now watching things around southern portions of NC for later tonight as the warm front moves northward overnight, with this comes the chance for storms as more unstable airs moves in 

though the warm front may not make much progress into North Carolina tonight and may move north by early tomorrow as seen in this HPC forecast image overnight (2am) 

Though the chance is low, any storms that can develop has a good chance of rotation and with the cloud bases close enough an isolated tornado is possible (but again low chance) 

Heavy rain event on the way for for state (NC)

Large scale rain event is taking shape across the southern half of the country. We see this on the Surface map (9:30pm EDT) 

Looking at water vapor satellite an upper low is seen over TX (outlined in red) and also in red on the top of the image is the northern stream energy that will give a kick to the southern stream over TX.

Taking a look at Monday morning we can see the northern and southern jet stream coming close to what looks like a phasing of the two jet streams. 

This should help develop a surface Low over the Gulf states-

Easterly winds here in central NC will keep transporting moisture off the Atlantic and keep things damp in some areas across the state before the heavier rains move in! 5day rainfall forecast 

Winter like pattern for eastern US in June?

        Current temps across most of the eastern US are more like fall than early summer. The reason for this is a big upper Low over the North East US seen below on water vapor satellite.

This upper Low being almost stationary for most of next week is being caused by a negative NAO or a large blocking High pressure over Greenland. This will keep most of the eastern US and North East cool with New England staying cool, cloudy and rainy at times. Here for central NC we should be temps head back to around 80 for Sunday and maybe Monday before that upper Low sends another bit of upper level energy down through parts of the Mid West and through the South East mid week seen here on the GFS model.

A frontal boundary should stall and perhaps washout somewhere over the South East next week as seen by the ECMWF model for Wednesday. 

So  while the start of June should be cool and below normal for much of the eastern US, there are some signs of the -NAO breaking down and much warmer/hot weather should flood the eastern US later in June.

StormSquad.net to be at Stormfest in Raleigh.

News has come today that we (StormSquad) will be giving a presentation at StormFest in Raleigh on June 16 2012. More info to come.
-Nic

GFS picking up on the pattern change (SOME) but still lack of good blocking

 The GFS is catching on to a more colder possible stormy pattern to end December. Here in this image I have the GFS for Dec 24th (left) and Dec 26th (right) Now Not sure that this would being snow (if any) to NC east of the Mnts BUT has been showing up run to run.

NAO (seen here>, looks to go a bit Neg but still not a strong blocking signal at all. 
The AO also goes down some which would also help (SOME) this too is not enough to dump too much cold south 

If you scroll through this link here (which is the GFS ensemble members) start at hour 264 and so on, some do show a coastal storm off the SE US coast and some cold air in place (noted by the 540 red line over NC) http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/ensloopmref.html

Recap of the April 9th VA/Carolinas severe weather event.

Well most of Saturday here in Central NC was cool and damp here at the surface, but yet we still had severe weather and storms how this is so, well for those who want to know Ill explain.
At 12z(8am local) we had a backdoor front push all the way to the Charlotte metro/upstate SC with most of central NC in a cool surface stable wedge.

Also the 12z SPC sounding showed a cool layer of air at the surface but just above that about850mb(5000ft) there was warm moist unstable air.

Along with some weak CAPE but lapse rates from 700mb to 500mb were 7c/km cooling with height also dry air was noted in a deep layer as well. Water Vapor imagery at 11:30am showed a short wave in the mid west with an MCV at the surface.

also note the SE ridge overhead. Fast forward a bit in time and by 4pm we started seeing severe storms show up over KY/VA and TN.

by 4:40pm we started to see supercells break out in W/SW NC with tornado warnings out.(heres base reflectivity and Velocity from GSP SC radar.

while still at the surface for central NC(all but Charlotte metro where dewpnts were in the 60s and temps in the 70s, this served as a focus for storms to train along.

but still storms were on going over the cool stable wedge airmass over central NC.

Where heres some answers as to why and how. First RUC analysis showed a 500mb short wave passing by helping to get lift going and the storms.

 

Sfc temps were in the 50s to upper 40s.

Along with the short wave and steep mid level lapse rates that produced a lot of lightning but also remember the 12z Greensboro sounding showed warm temps and good moisture at 850mb well heres a product called Theta-E all it is, is temp and dewpoint combined and the higher Theta-E the more unstable heres what we look at around 6/7pm.

Also Lifted index above the surface here very low and unstable

All and all this was a good severe weather event to learn something from and study for future setups hope you enjoyed.

More severe weather on the way.

After what seemed like an endless winter for people in the Mid West and Chicago, it looks like another severe weather event will come together for these areas starting on Sunday.
Lets take a look at the setup here and one thing I like to look at for convection is called Theta-E. Simply put this is a combination of the surface temperature and dewpoint. The higher the temp and dewpoint the higher the Theta-E and it is a good place to look for possible convection. Heres Sundays Theta-E map.

Next we need to look for CAPE, and in this case surface based CAPE.

Those two parameters alone can give you an idea if storms are possible but if a strong cap is in place or nothing to get lift going then your likely not to have much, but in this case we will have a lifting trigger and thats the cold front. Taking a look at the Helicity  values there will be some of that/Along with EHI values over 1 and that means a higher potential for tornadoes.

Also for supercells I look at the Sfc-1km shear and shear in this area of 30-40knts or greater means a higher likelihood of supercells. This is for overnight Sunday.

and 6hr precip overnight.

And with all this in mind NC also looks to get in on some severe weather by day3

Thats all for now Ill hae more later.