Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 182334
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
634 PM CDT Tue Jul 18 2017

.SHORT TERM...(Tonight through Friday)
Issued at 321 PM CDT Tue Jul 18 2017

Forecast concerns in the short term will be thunderstorm chances
along with heat advisory/heat warning headlines.

The latest surface analysis has a cold front into northern
Nebraska...northern Iowa and southeast Minnesota. Temperatures to
the south of the front were in the 80s and 90s...and very moist
dewpoints from 72 to 76 degrees were pooled over southeast
Nebraska and southwest Iowa. The convective complex that dropped
5+ inches of rain over south central Nebraska overnight had
drifted eastward into Iowa and Missouri.

With the heating this afternoon...beginning to see convection
increase along the front in southeast MN/northern Iowa. visible
satellite shows some growing cu in southeast Neb. The RAP/HRRR
tends to focus on areas near the Missouri River and western
Iowa...while the GFS is broad and ill-defined...the EC is mainly
dry...and the 18Z NAM12 is mainly dry. The low level jet is
forecast to develop tonight over central Nebrsaka, however the
NAM is still dry with this due to the warm mid level temperatures.
With a very moist and unstable environment will have highest pops
near the front in northeast Nebraska, but also cannot rule out
other storms that form in western Iowa into southeast Nebraska.
Due to the low confidence...have isolated to scattered pops. SPC
has the slight risk into northeast Nebraska, just unsure how far
southwest those storms will develop. The storms developing out in
western Nebraska may have trouble as they move east due to the
warm temperatures aloft. Later tonight storms a few storms may try
to develop in southeast Nebraska and southwest Iowa...so will
need to monitor for these.

The front lifts north and he heat is expected to then build in
over the next several days. Storms near the front will have an
impact and could bust the temperatures...however for now have hot
temperatures in the 90s to around 100 degrees each day Wed-Fri.

The combination of the heat and the humidity will push heat index
values to 105 for the advisory area and 105 to 115 for the
excessive heat warning.

.LONG TERM...(Friday night through Tuesday)
Issued at 321 PM CDT Tue Jul 18 2017

Cooler weather is still forecast to push into the forecast area
this weekend as a front pushes south into the forecast area. Highs
in the 80s to lower 90s are expected.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 634 PM CDT Tue Jul 18 2017

Mesoanalysis at 23z revealed a weak surface front from northwest
IA into northeast NE. Little movement to this boundary is
anticipated overnight with light southeast winds persisting to its
south. Mid and high-level clouds are expected to overspread
northeast NE this evening with the potential for an isolated
shower or thunderstorm. Confidence in any convective occurrence at
KOFK remains quite low, so no mention will be made in the TAF.
Otherwise, expect VFR conditions to prevail with increasing south
winds on Wednesday.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Excessive Heat Warning from 1 PM Wednesday to 8 PM CDT Friday
     for NEZ034-044-045-050>053-065>068-078-088>093.

     Heat Advisory from 1 PM Wednesday to 8 PM CDT Friday for NEZ011-
     012-015>018-030>033-042-043.

IA...Excessive Heat Warning from 1 PM Wednesday to 8 PM CDT Friday
     for IAZ055-069-079-080-090-091.

     Heat Advisory from 1 PM Wednesday to 8 PM CDT Friday for IAZ043-
     056.

&&

$$

SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...Mead



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