Scientific Forecaster Discussion
fxus63 kpah 232139
Area forecast discussion
National Weather Service Paducah Kentucky
439 PM CDT Sat Mar 23 2019
issued at 437 PM CDT Sat Mar 23 2019
Updated aviation discussion for 00z taf issuance.
Short term...(this evening through Monday night) issued at 251
PM CDT Sat Mar 23 2019
A mild afternoon with mid and high clouds spreading into the
western sections of the County Warning Area ahead of a cold front producing
showers and thunderstorms over the Southern Plains. The main low
was over northwest Kansas. Radar is showing showers over the far
west, but the air is so dry nothing more than sprinkles expected
All models in general agreement of scattered showers - isolated
thunderstorms spreading across the area tonight as the upper low
moves into Nebraska and shortwave energy moves toward US.
These initial showers will mainly be a morning feature and
quickly move out of the area. Models increase SBCAPE and bulk
shear during the afternoon hours over Missouri and Illinois. There
may even be a few breaks in the clouds. Lapse rates are marginal
but due to the strong shear, Storm Prediction Center has put our 4 westernmost
counties in a slight risk and the marginal risk extends along and
west of I-57. The threat will diminish during the evening hours.
Although a few showers and clouds may linger into Monday, high
pressure will gradually dry the area out by Tuesday.
Long term...(tuesday through saturday) issued at 251 PM CDT Sat
Mar 23 2019
Forecast confidence is rather high for a nice warm up through the
week, but lower for shower and thunderstorm timing and location
Thursday into the weekend.
Surface high pressure and northwest flow Tuesday will keep US dry
with temperatures several degrees below normal. A ridge aloft will
slide across the area on Wednesday which will push the surface high
to our east and allow south winds to develop across the region. High
temperatures will Jump Up to normal levels Wednesday.
As low pressure develops over the plains south winds will increase
and become gusty on Thursday. Continued warm advection may lead to a
few light showers over southeast Missouri and southwest Illinois
Thursday afternoon and evening. Afternoon temperatures will climb
well above normal.
The medium range models develop a complicated trough aloft over the
western half of the country Thursday into Friday, and the timing of
individual impulses through our region Thursday night through
Saturday will be difficult to pin down. The 12z GFS has been fairly
consistent the last couple of runs and has been followed fairly
closely for this forecast.
The 12z GFS lifts a lead impulse northeast from the plains Thursday
night to the Great Lakes by Friday evening. This will bring better
chances of showers to the northwest half of the area late Thursday
night and Friday morning. The trailing cold front will then sag
slowly southeast through our region later Friday and Friday night.
Likely pops are forecast with the front, along with a slight chance
Looking into next Saturday, the front hangs up over west Kentucky
and lifts back north as warm front through the day. Heights are also
rising, so coverage of showers and potentially thunderstorms is in
doubt. Will cap pops at chance levels, with the best chances over
west Kentucky. Given uncertainties amongst the available guidance we
will not introduce thunder to next Saturday just yet.
issued at 437 PM CDT Sat Mar 23 2019
Time/height cross sections show saturation down the column with
time, as warm advection clouds lower thru VFR and flirt with MVFR
bases with showers later tonight-early tmrw. Cigs will be
maintained from low VFR to MVFR into/thru the day, as winds
continue to veer to the south, and increase/with gusts tmrw.