FXUS64 KOHX 222056
AFDOHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
256 PM CST TUE DEC 22 2009
.DISCUSSION...
STRONG SYSTEM EVIDENT ON WATER VAPOR IMAGERY DIGGING INTO THE
SOUTHWEST CONUS ATTM WILL BE MAIN PLAYER WEATHERWISE FOR THE MID-
STATE THIS FORECAST PERIOD. LATEST MODEL GUIDANCE IN RELATIVELY
GOOD AGREEMENT THAT THIS SYSTEM WILL PHASE WITH A NEW PIECE OF
NORTHERN STREAM ENERGY THURSDAY RESULTING IN A VERY POWERFUL STORM
SYSTEM OVER THE EASTERN 1/2 OF THE NATION.
AS FAR AS SENSIBLE WEATHER GOES...SOUTHERLY FLOW WILL STRENGTHEN
STEADILY THROUGH THURSDAY. TEMPS WILL REMAIN ABOVE NORMAL THROUGH
THE PERIOD...AND I LEANED WARMER THAN THE MAV NUMBERS FOR HIGHS
THROUGHOUT. DEEP MOISTURE WILL INCREASE...BUT WITH LLVL FLOW
FROM THE SOUTHEAST THE BOUNDARY LAYER WILL REMAIN PRETTY DRY
UNTIL RIGHT AHEAD OF FROPA THU NGT. CONTINUED PREVIOUS FORECAST
TREND OF A WEST-EAST POP GRADIENT WED INTO EARLY THU WITH
CATEGORICAL COVERAGE EXPECTED LATE THU INTO THU NGT. SHOWALTERS GO
NEGATIVE FOR A TIME THU NIGHT SO CUD SEE SOME THUNDER...AND MAY
EVEN SEE A SHALLOW CONVECTIVE LINE ALONG AND AHEAD OF THE FRONT.
AS STORM DEEPENS TO OUR WEST...WINDS WILL STRENGTHEN THROUGH THE DAY
THU. GFS IS STRONGEST...60+ KTS AT 925 MB OVER PARTS OF OUR CWA
LATE THU. NAM IS WEAKER...BUT STILL SUGGESTS POTENTIAL FOR 25+ MPH
SUSTAINED WINDS AND GUSTS IN THE 40-45 MPH RANGE. WILL HIGHLIGHT
WIND THREAT IN SPS/HWO AS THURSDAY WILL NO DOUBT BE A BUSY TRAVEL
DAY ACROSS THE REGION.
UPPER LOW WILL THEN BASICALLY SIT AND SPIN OVER THE GREAT LAKES
THROUGH THE EXTENDED. THIS WILL LEAD TO A PERIOD OF MUCH COOLER
TEMPS...CLOUDY SKIES...AND CHANCE FOR LIGHT PRECIP MAINLY OVER THE
PLATEAU.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 40 55 45 58 / 10 40 30 100
CLARKSVILLE 41 54 46 58 / 10 60 60 90
CROSSVILLE 35 52 40 56 / 10 20 30 100
COLUMBIA 41 56 46 59 / 10 40 30 100
LAWRENCEBURG 40 56 46 59 / 10 40 50 100
WAVERLY 42 55 47 58 / 10 60 60 80
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JOHNSTONE