FXUS63 KDVN 141121

Area Forecast Discussion
National Weather Service Quad Cities IA IL
621 AM CDT Fri May 14 2021


Issued at 236 AM CDT Fri May 14 2021

Clear skies and quiet conditions were seen early Friday morning,
with large surface high continuing to slowly move off to the east.
Many areas were reporting calm winds as of 2 am, allowing temperatures
to drop into the lower 40s. 00z upper air analysis showed
substantial mid level dry air locally, with DVN/ILX sounding PWs
in the 5th and 10th percentile respectively.

Morning GOES water vapor shows several weak shortwaves embedded
in the northwest flow aloft, with the strongest over NE aiding
support to some showers and thunderstorms along the KS/NE border.
Mid and high level clouds were moving across western IA ahead of
this wave.


.SHORT TERM...(Today and Tonight)
ISSUED AT 236 AM CDT Fri May 14 2021

Forecast focus in the near term is on rain chances tonight.

Increasing clouds will be seen from west to east today, as
aforementioned shortwave drops east southeast into northern MO.
Better moisture return will be to the west of the CWA for most of
the day. This will bring dry conditions to all areas through at
least early afternoon and perhaps even later if latest model
trends are correct. NBM hourly PoP dprog/dt also confirms this and
I wouldn`t be surprised if much of the forecast remains dry
through 00z Saturday. Any precipitation that does occur today will
be light showers with little QPF. Raised highs a few degrees today
especially in the eastern half given the lower dewpoints this
morning compared to model values, and where more sunshine is
expected. Highs will be similar to yesterday, with readings in the
upper 60s/low 70s.

Tonight...increasing LLJ and moisture return will bring elevated
showers and perhaps some isolated non-severe thunderstorms to the
region. Rain coverage will be greater with a mid level wave
providing better lift, in addition to increasing upper level
divergence. QPF amounts between a tenth and a quarter of an inch
are forecast. Cloud cover and southerly winds will keep
temperatures up overnight tonight, with readings only dropping
into the upper 40s/low 50s.

.LONG TERM...(Saturday through Thursday)
ISSUED AT 236 AM CDT Fri May 14 2021

1. A prolonged period of diffuse forcing for showers and some
thunderstorms will exist through next week.

2. While there`s a threat for some rain each day, the overall
precipitation appears weakly forced and without significant CAPE,
dry periods are likely, and heavy rain seems unlikely on any
problematic scale.

The elevated precipitation threat will continue from late tonight
into Saturday, with the best chances in the southeast 1/2, mainly in
the morning. Rather dirty northwest flow exists behind the main
short wave aloft Saturday and Sunday, so we will continue the slight
chance pops to cover elevated showers.

Another period of isentropic lift is expected Sunday afternoon
into Monday, which will bring a somewhat higher chance for
rainfall over 1/2 inch as moisture is much more available. The 00Z
ECMWF continue to support PWAT values of 1.25 to 1.50 beginning
Sunday night, and continuing through the week. Thus, storms will
be more capable of producing heavy downpours this upcoming week,
though the weak forcing combined with a lack of forecast
instability, should limit the overall rain amounts as well as keep
the severe weather threat low.

Temperatures Saturday with plenty of clouds, and some rain, will be
held to the mid 60 east to upper 60s west.  Sunday through Thursday
appears set for sustained seasonally mild conditions with plenty of
mid to upper 70s for highs, and if we can see a sunny and dry day in
there, lower 80s would certainly be possible. Lows in the 50s
through Sunday night look to increase to the lower 60s through the


.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
ISSUED AT 616 AM CDT Fri May 14 2021

VFR conditions will prevail through most of the TAF cycle.
Clouds will increase throughout the day ahead of approaching wave
to bring rain showers to the forecast area late tonight. There may
be a band of showers this afternoon that develops over east
central Iowa, but confidence too low to include in CID TAF. MVFR
cigs will begin to develop at the end of the period and just





NWS DVN Office Area Forecast Discussion