yellow alert for friday

by

not the red alert from start trek but the other one that is used for anticipated danger. In this case i’m seeing another potential hvy rain set-up and severe threat for friday.

let’s go through the set-up

–  we have another strong frontal boundary diving south into the plains, a ridge off the east coast will slow the movement of the boundary and bring north plenty of tropical moisture. Thunderstorm development will occur thanks to a low pressure with a trough and upper level energy moving east from the plains east into the great lakes.

– the big question for us is where does this front set-up

NAM model

– numerous training storms and showers already in progress along the boundary friday morning

periods of storms continuing into the early afternoon north notice how the ridge is keeping the storms moving over the same areas and not progressive to the SE as with a normal front.

– sunshine allows more instability in the afternoon which can allow the storms to organize into a squall line friday night

– more training of storms overnight with hvy rains

total rainfall notice 3-5 for lou and 2-4 for a lot of folks

the gfs is more optimistic on impacts

– numerous training storms friday morning

– a totally different picture for friday night

as a result rain totals from 1/4 to 1 inch are found and no big deal

so what do i think

–  that the nam might be onto something with a very slow frontal passage as the gfs bias is to be to fast with fronts but in order to commit to it i would need to see two or three runs that are similar. I do think the gfs coverage for friday night is not correct and the nam’s squall line may be closer to what we see. again yellow alert a rough day may be coming or it may be just another period of showers and storms like the last two rain chances. I’ll commit after seeing the 12z runs. I’ll be driving from bowling green  to versailles thursday (tomorrow) morning so if want wave hi as i pass nearby your house on the interstate you’re more than welcome to!!!

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2 Responses to “yellow alert for friday”

  1. mitchg Says:

    quote from AL at nws “HOWEVER WITH NAM
    BUFKIT AND GFS SOUNDINGS INDICATING 500-600 M2S2 STORM-RELATIVE
    HELICITY VALUES AROUND 12Z FRIDAY…MY EYEBROWS HAVE BEEN RAISED.
    CAN NOT RULE OUT AN ISOLATED TORNADO OR TWO GIVEN THE STRONG SPEED
    AND DIRECTIONAL SHEAR IN THE LOWEST 3KM TOWARDS DAWN FRIDAY. COULD
    BE A MESSY START TO THE FRIDAY MORNING COMMUTE.”

    something defintelty to keep an eye on. whenever you have a warm and cold front the intresection point quite often can be the focual point for a tornado or two.

  2. mitchg Says:

    the northern part of the boundry is more of a cold front but can be technically a warm front as it will wobble around for the next 24 hrs.

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