Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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FXUS63 KOAX 191115
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
615 AM CDT TUE JUL 19 2016

.SHORT TERM...(Today through Friday)
Issued at 328 AM CDT Tue Jul 19 2016

...Hot and Humid Wednesday through Friday and could extend into
the weekend...

Forecast concerns in the short term will be convection moving into
the forecast area today and how long it will last, then attention
turns to the hot weather expected for the rest of the week and
early this weekend and heat headlines.

Water vapor satellite imagery and the WSR-88d mosaic shows
abundant mid level moisture streaming from the Pacific and across
Mexico into the southwest U.s. and the Rockies to the Midwest with
a convective complex that has made its way across Nebraska. A low
amplitude short wave over southeast Wyoming last night will track
northeast toward southeast South Dakota by 18z today.  Low level
jet progs show a 35 to 40kt wind nosing into northeast and east
central nebraska this morning...veering slightly and weakening to
30kts by 15z and 25kts by 18z while shifting north.

The SPC HRRR/RAP13/ESRL HRRR are in general agreement with the
convection lifting northeast across northeast Nebraska and with
some enhanced storms in Iowa just outside of our forecast area. With
this in mind combined with upper level jet support, abundant
moisture, steep lapse rates, and best warm air advection, will
maintain highest pops in northeast Nebraska and more scattered or
isolated pops farther south. Some persistent warm air advection
continues into the afternoon and although the bulk of the storms
should lift out of the area...some could linger on the fringes of
the warm air moving in. High temperatures today should be in the
upper 80s to mid 90s.

The warmer air continues to build in with h85 temperatures warming
from 22C to 26C to 30deg C over the next couple of days as the
short range models have a large h5 high pressure system over the
central part of the country. There are some perturbations in the
flow which could produce a few storms...however with the 14 to 15
deg h7 temperatures in place...opted to keep the dry and hot
forecast going for Wed through Thursday night. The mid level flow
is still very moist during this period. Forecast soundings show
inverted v soundings Friday...so something to keep in mind since
we have isolated storms mentioned.

Related to headlines...We have an excessive heat watch in effect
with hot temperatures forecast for Wednesday through Friday. In
coordination with surrounding offices a heat advisory/heat warning
will likely be needed as heat index values of 105 to 110 appear
likely. Will maintain the EH watch and a call today with
surrounding forecast offices can convert headlines as needed with
our hottest days being Thursday and Friday.

.LONG TERM...(Friday night through Monday)
Issued at 328 AM CDT Tue Jul 19 2016

The excessive heat will be firmly in place Friday and ahead of the
front Saturday. The front will be our next chance for scattered
thunderstorms Saturday afternoon and Saturday night. Cooler highs
in the 80s Sunday and Monday. Monday and Tuesday look unsettled with
a chance for thunderstorms each day as we have cool air to our
east and warm air to the west with favorable convergence over
parts of the area.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 615 AM CDT Tue Jul 19 2016

Spotty TSRA possible this morning...but at least for the initial
12Z TAFs will only include some VCTS. Main lift appears to have
moved into western IA. Activity to the west has been moving east
but not sure how much will remain intact through mid morning. Will
amend as needed. Otherwise this afternoon and evening look dry but
there will be some LLWS developing tonight.

&&

.OAX Watches/Warnings/Advisories...
NE...Excessive Heat Watch from Wednesday morning through Friday
     evening for NEZ011-012-015>018-030>034-042>045-050>053-
     065>068-078-088>093.

IA...Excessive Heat Watch from Wednesday morning through Friday
     evening for IAZ043-055-056-069-079-080-090-091.

&&

$$

SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...Miller


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