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000
FXUS63 KBIS 252328
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
628 PM CDT Sun Jun 25 2017

.UPDATE...
Issued at 623 PM CDT Sun Jun 25 2017

Isolated diurnal showers and thunderstorms will continue to fade
through sunset across the south central. Will continue to evaluate
the frost threat for tonight with surface high pressure in place
and strong radiational cooling expected. However, a slightly
warmer start to the evening and higher dewpoints as compared to
the last couple nights should limit the threat.

&&

.SHORT TERM...(This evening through Monday)
Issued at 324 PM CDT Sun Jun 25 2017

Shower activity and another cool night ahead, followed by a sunny
and warmer day on Monday highlight the short term period.

Currently, surface high pressure was centered over central
Saskatchewan. Shower activity was over far south central ND and
moving south/southeast. Isolated showers developed near Rugby/Devils
Lake this afternoon...also moving southeast. Thunder is not out of
the question, but activity should be isolated and not severe.

CAMs indicate shower activity continuing to move south/southeast and
dissipating and/or moving out of the state by early evening.

Tonight will likely be another cool night with surface high
pressure settling over central ND by daybreak. This with light winds
and clear skies over central ND have lowered min temps for tonight
from guidance, which has been bias towards higher temps overnight
lately. This Sunday morning we saw temps reaching the lower and mid
30s in parts of the southwest, so lowered current forecast a tad,
which is lower than any of the guidance.

.LONG TERM...(Monday night through Sunday)
Issued at 324 PM CDT Sun Jun 25 2017

Warm and humid with thunderstorm chances on Tuesday. Otherwise
seasonably cool through most of the long term period.

After another cool night Sunday night, the return southerly flow
Monday and Monday night as the surface high center moves off to the
southeast will allow temperatures to rise into the 70s across our
area Monday and lower only to the upper 40s in the James
Valley to the mid 50s in the far west.

On Tuesday, a cold front will move into the western Dakotas during
the afternoon. Ahead of this we will see warm temperatures and
moisture return to the area with an increasing southerly return
flow. The thermal ridge pushes into western ND Tuesday afternoon
just ahead of the cold front. Used the previous forecast for max
temps on Tuesday, as guidance seemed too low with h850 temps of +20C-
+26C, with the GFS indicating a warmer h850 temp field Tuesday
afternoon. The NAM may be bringing in more cloud cover near the
trough/front as well as from the northwest behind the front, and this
may be swaying guidance lower. Think with mid level cap and heating
should favor fewer clouds and went with a warmer day. Regarding
thunderstorm potential, through 00Z we remain pretty strongly
capped. When the mid level trough pushes into the west from 00Z-03Z
Wednesday, the thunderstorm threat should increase as the cap
erodes. The GFS and SREF are slower bringing in the trough in the
late afternoon/early evening, while the NAM is quicker, having the
trough entering western ND in the early afternoon. Severe parameters
of CAPE and bulk shear are still indicating a chance of severe
storms...whether they begin in the late afternoon in the west, or
not until the evening hours. The severe parameters indicate the late
afternoon/evening hours have the better support for severe storms.

Beyond Tuesday, the upper low associated with this system begins
to drop south from Canada which keeps a chance of shower and
thunderstorms in the forecast through Friday, with another system
possible late in the weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 623 PM CDT Sun Jun 25 2017

Isolated showers and thunderstorms south central and across the
James River Valley will fade with sunset this evening. VFR
conditions are expected across all of western and central North
Dakota for the 00 UTC TAF period.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...PA
SHORT TERM...JV
LONG TERM...JV
AVIATION...PA