westward trend continues minus the NAM

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I have seen a large shift westward today in the models that usually occurs with apps cutters unlike most systems a westward trend favors the region for snowfall. I’m also bringing the edge of the accumulating snow northwest to the Ohio River.  my latest thinking lies in more with the 12 ecmwf and gfs ensemble mean for qpf and the GFS for dynamical cooling and thermal profiles. My thinking continues to be a mix for a few hours in  most places before a change to snow though the southeast could stay rain longer.  Even with that period of rain a wet snowstorm appears on tap for southern and eastern Kentucky.  My regions of less confidence now are from Bowling Green to Lexington with a higher confidence today out east and toward Louisville.  I’ll go more into the meteorology behind the forecast with another forecast update later tonight which will be minus the euro given that classes are back in session.

Bowling green and Lexington metros 2-4

Louisville, Frankfort, dry ridge 1-3

Jackson, Pikeville, Somerset 6-10

Ashland 3-6

this will be a heavy wet snow.

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9 Responses to “westward trend continues minus the NAM”

  1. Mike S Says:

    That is pretty BOLD on the snowfall totals…lol. I like it though….I’d take 6″-10″ in Somerset 🙂

  2. mitchg Says:

    we’ll see i have a feeling i may have to take back down a noch. I’m expecting the main snow band northwest of the upper low to track from nashville to somerset to pikeville some convective snows are possibile as well which io why I have amounts slightly higher for the somerset region for now.

    the 18z gfs matches up well for bwg and lou but is off oof my forecast for jkl, london and lex.

    i will likely have to fine tune this once again.

  3. marsha Says:

    Morgan co going down also mitch?

  4. mitchg Says:

    nam brings smiles to my faces this makes the coating forecasted for bwg even more skeptical now.

  5. marsha Says:

    what about morgan co mitch please I’m dying here lol….

  6. Seth Says:

    Saw the 18z nam. Wish the heavy precip shield were farther north to include covington but oh well.

    It will be interesting to see how high temps get tomorrow ahead of the storm. Should be a good indicator of how quickly it will take for the rain to change to snow.

  7. mitchg Says:

    think the nam is to slow with the changeover in many locations but about right in BWG.

  8. Hardball Says:

    Mitch, new nam very close to your first call. Awesome job man, you have been spot on all winter!
    Hope it verifies!

  9. mitchg Says:

    MJ has written a discussion tonight and it’s right on in my view.

    WITH REGARDS TO THE TUESDAY NIGHT/WEDNESDAY SYSTEM…QUICK ANALYSIS
    OF THE LATEST 24/21Z SREF ENSEMBLES AND 25/00Z NAM RUNS CONTINUE TO
    TREND A BIT MORE WESTWARD WITH PRECIPITATION SHIELD AS AN AREA OF
    SFC LOW PRESSURE MOVES NORTHEASTWARD ACROSS THE SOUTHEAST STATES.
    WHILE THE PRECIPITATION TRENDS HAVE BEEN DEVELOPING WESTWARD…THE
    ACTUAL SFC LOW TRACK IS NOT REALLY SHIFT VERY MUCH TO THE WEST.
    INSTEAD…THE NAM AND TO SOME EXTENT THE SREF GUIDANCE IS KEYING ON
    DEVELOPING AN IMPRESSIVE TROUGH OF WARM AIR ALOFT (TROWL) AND
    SWINGING IT AROUND INTO KY LATE TUE NIGHT AND WEDNESDAY MORNING.
    STRONG FRONTOGENETICAL FORCING IN THE 700-500MB LAYER IS QUITE
    IMPRESSIVE SUGGESTING MODERATE TO HEAVY BANDED PRECIPITATION.
    INITIAL THERMAL PROFILES ARE STILL QUITE WARM TUESDAY AFTERNOON
    SUGGESTING THAT THE INITIAL PRECIPITATION WILL LIKELY FALL IN THE
    FORM OF RAIN.

    HOWEVER…STRONG FORCING AND LIFT WILL LIKELY RESULT
    IN DYNAMICAL COOLING WHICH SHOULD RESULT IN A QUICK CHANGE OVER TO
    SNOW TUESDAY NIGHT AND EARLY WEDNESDAY MORNING. THE SREF ENSEMBLES
    IN GENERAL AGREEMENT WITH THE SCENARIO…BUT OVERALL…THE SREF IS
    STILL A BIT WARMER WITH TEMPERATURES. THE 25/18Z OPERATIONAL AND
    GFS ENSEMBLES ALSO SEEM TO BE IN AGREEMENT WITH THE LATEST NAM RUN
    AS WELL. IN GENERAL…IT APPEARS THAT THE GREATEST THREAT FOR
    SIGNIFICANT SNOWFALL…SHOULD THIS PAN OUT…WOULD GENERALLY BE IN A
    SW-NE CORRIDOR FROM ABOUT BOWLING GREEN NEWD TO ASHLAND KY…OR
    GENERALLY SOUTH OF THE BLUEGRASS AND WESTERN KY PARKWAYS. BOTH THE
    SREF AND NAM RUNS HAVE A SHARP CUT OFF IN PRECIP TO THE NORTHWEST OF
    THE PARKWAYS. IN FACT…BOTH MODELS BARELY HAVE ANY QPF NORTH OF
    THE OHIO RIVER. ON THE OTHER HAND…THE GFS IS A BIT MORE ROBUST
    WITH ITS PRECIPITATION SHIELD. IT SHOULD BE NOTED THAT A WELL KNOWN
    GFS BIAS IS THAT IT OFTEN PREDICTS LARGE AREAS OF LIGHT QPF. THIS
    BIAS IS CARRIED IN THE ENSEMBLES AS WELL. THUS…I THINK THE SREF
    AND NAM QPF FIELDS SEEM REASONABLE FROM A METEOROLOGICAL PERSPECTIVE.

    SHOULD THE NAM/SREF EVOLUTION CONTINUE IN FUTURE RUNS…OR HAVE
    STRONGER AGREEMENT FROM THE GFS…HEADLINES WOULD LIKELY BE NEEDED
    WITH THE MORNING FCST ISSUANCE.

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