FXUS63 KBIS 191827

Area Forecast Discussion
National Weather Service Bismarck ND
127 PM CDT Thu Jul 19 2018

.SHORT TERM...(This evening through Friday)
Issued at 112 PM CDT Thu Jul 19 2018

Continued showers and thunderstorms this afternoon and tonight, a
few of which may be strong to marginally severe.

A slow moving closed upper level low will continue moving eastward
out of the Dakotas and into Minnesota tonight. Scattered showers
and storms will develop across western and central North Dakota
this afternoon and evening. Latest mesoanalysis indicates an
environment (2000 J/Kg CAPE, 30 knots of shear and steep lapse
rates) that is favorable for a few strong or even severe storms
this afternoon with hail up to quarter size possible and wind
gusts up to 50 mph. In addition to the hail threat, locally heavy
rainfall will be likely as these storms will be slow moving in a
moisture-rich atmosphere. Any storm that does become strong to
severe will likely not be long-lived, as the environment looks
supportive for pulse-like air mass thunderstorms rather than more
organized convection.

.LONG TERM...(Friday night through Thursday)
Issued at 112 PM CDT Thu Jul 19 2018

Drying out across western and central North Dakota Friday and
Saturday, with the next chance for severe weather arriving

A ridge will build in from the west on Friday as the upper level
low over Minnesota continues moving eastward into the Great Lakes
region. This will lead to a mainly dry day across western and
central North Dakota on Friday, with the latest blend of model
guidance suggesting pleasant temperatures with highs in the mid
70s to lower 80s.

The ridge axis will move over central North Dakota on Saturday,
leading to another dry and pleasant day with temperatures warming
up a bit more than Friday, into the low to mid 80s.

A shortwave trough with an associated surface cold front looks to
swing eastward through the area Saturday night and Sunday. This
front will be the focus for thunderstorm development. The
environment during this time looks favorable for severe weather,
especially Sunday afternoon and evening. The latest long range
model data agrees well on a sheared environment of 40 to 60 kts
of bulk shear, collocated with high instability and a cold front
moving through.

Behind this front, the synoptic scale flow aloft becomes nearly
zonal to northwest for Monday through Wednesday. A few weak
impulses look to be embedded within the large scale flow,
bringing more chances for showers and storms.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1152 AM CDT Thu Jul 19 2018

Expect VFR cigs and visibilities at all terminals through the end
of the TAF forecast period. The main concern will be scattered
showers and thunderstorms. Gusty and erratic winds are possible
near storms, along with locally heavy rainfall and frequent




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