Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 291147

Area Forecast Discussion
National Weather Service Des Moines IA
647 AM CDT Wed Jun 29 2016

.SHORT TERM.../Today/
Issued at 326 AM CDT Wed Jun 29 2016

Main concerns center around pops and temperatures for today. Weak
baroclinic zone in place across the western CWA into ERN NE and SE
SD. This will slightly push east today. Some scattered weak
thunderstorms currently forming to the west/northwest near this zone
and also in area of weak theta-e advection. This will become
oriented into the CWA through the morning hours and continue through
the day. This is in advance of a weak impulse of energy dropping
through SD attm and will continue to push southeastward through the
state today. With all the subtle features, and little overall
organization of the convection expected, uncertainty was high this
activity was going to develop overnight. As it has and looks to
continue to fester through the day given the weak features in play,
have increased pops through the morning hours with higher likelihood
of seeing some weak storms through the western CWA by mid/late
morning. Additionally may see the area blossom a bit into the
afternoon hours. Activity however could be limited this afternoon
given the limited heating today due to the large cirrus cloud shield
in place and especially across the west in areas where storms have
already moved through. Therefore have just small chance/slight
chance pops into the afternoon hours.

As for temperatures went a degree or two cooler than the previous
grids due to the cloud cover and dropped the west central even more
given the precipitation chances through the day.

.LONG TERM.../Tonight through Tuesday/
Issued at 326 AM CDT Wed Jun 29 2016

From tonight into Thursday morning we will likely see a repeat of
this morning with scattered benign thunderstorms forming overhead.
Despite weak flow and little organized forcing, a subtle mid-level
shortwave moving overhead during the climatologically favored
early morning hours should allow for this convection to develop,
probably centered more over our forecast area as opposed to this
morning where it is more along the Missouri river valley. Have
maintained generally 20 to 40 POPs accordingly.

During the day on Thursday a cool front will push southward across
Iowa, probably triggering a few more thunderstorms mainly in the
afternoon and evening. However, instability and shear will both be
limited and severe weather is unlikely. Behind this front cool and
dry weather will dominate the end of the week, ushering in July
with below normal temperatures. Meanwhile the front that passed
across Iowa on Thursday will stall to the south and reactivate
with the approach of a mid-level trough on Friday and Saturday.
This will bring heavy rainfall and severe weather chances to parts
of Kansas and Missouri at the end of the week, but most or all of
this activity should remain south of Iowa. As the system slides
eastward far southern Iowa may be affected over the weekend, but
the primary threat in that area would be a slim possibility of
locally heavy rainfall.

Next week will begin with a zonal flow pattern that will allow for
persistent but nebulous thunderstorm chances along with steadily
moderating temperatures. There are some indications that right at
the end of the forecast period, around Tuesday/Tuesday night, a
shortwave impulse traveling through the flow may generate
thunderstorms across Iowa and the overall synoptic pattern would
indicate some potential for severe weather. However, the solutions
of such a feature at this range are erratic at best. A warming
trend around the middle of the week seems a higher confidence bet,
with temperatures likely climbing back into the lower 90s in some
areas by next Wednesday and Thursday.


.AVIATION.../For the 12Z TAFS through 12Z Thursday morning/
Issued at 646 AM CDT Wed Jun 29 2016

An area of thunderstorms moving through west central IA this
morning, and could impact KFOD and KDSM this am into mid-day.
Otherwise VFR conditions expected.





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