Scientific Forecaster Discussion
fxus63 kdmx 151158
Area forecast discussion
National Weather Service Des Moines Iowa
558 am CST Fri Nov 15 2019
Discussion.../today through Thursday/
issued at 406 am CST Fri Nov 15 2019
Progressive northwest to persist into next week across Iowa. Several shortwave
trofs embedded within the flow to provide a few periodic rounds
of light precip chances. Before then, the warmest day (still only
around seasonal norms) of the week lies ahead today, with SW winds
advecting warmer air from the Central Plains thermal ridge. This
will continue to melt snowpack from earlier in the week. Added
llvl moisture along with steep inversion will set the stage for
some patchy fog across the region tonight. Sref pinpointing
northeast and east portions of the County Warning Area as areas most susceptible
after midnight tonight. Fog lifts quickly Saturday as winds
increase ahead of Saturday night/Sunday morning's shortwave trof.
Saturday will be dry and breezy, with temperatures still hovering
around seasonal normals. Clouds will be on the increase through
Saturday ahead of the advancing shortwave trof. 00z model output
continue to show high pop/low quantitative precipitation forecast event that begins across central
Iowa around midnight Saturday night and continues through midday
Sunday. Precip type will vary across the County Warning Area with all rain
southwest, mixing with some freezing drizzle and/or -sn for
northern and eastern counties. Total quantitative precipitation forecast values for the event only
expected to be in the 0.05-0.1" range. Trough quickly swings
bringing all precip to an end Sunday afternoon. Another weak,
fast-moving shortwave to traverse the state again on Monday
bringing another chance for very light precipitation.
Dry conditions expected Tue-Wed as the Central Plains ridge
flattens as it shifts east towards Iowa. Temps will not fluctuate
all that much, with highs in the 40s north and 50s south.
Precipitation chances return Wednesday night/Thursday as northwest
flow amplifies in response to an approaching upper Midwest trof.
00z deterministic models are progressive and keep the bulk of the
quantitative precipitation forecast prefrontal. Lots of details to be ironed out, but have
maintained broad-brushed precipitation chances through this time.
Aviation.../for the 12z tafs through 12z Saturday morning/
issued at 558 am CST Fri Nov 15 2019
VFR conditions to prevail at terminals today with upper-level
clouds on the increase. Winds to slowly turn from southwest this
morning to southeasterly this afternoon with speeds of 5 to 8
knots. MVFR visibilities in patchy fog will be a good possibility
after 03z at most airfields.