Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 302021

Area Forecast Discussion
National Weather Service Bismarck ND
321 PM CDT Sun Apr 30 2017

.SHORT TERM...(This evening through Monday)
Issued at 320 PM CDT Sun Apr 30 2017

A cooler, cloudy and showery day expected on Monday. Gusty northwest
winds can also be expected in the west - especially southwestern ND.

Currently, the western edge of a high pressure ridge axis extended
across southern Ontario, northern Minnesota, and into northeastern
North Dakota. The large deep storm system in the central Plains was
centered over Kansas/Missouri, with the northern extent of a cirrus
cloud shield reaching eastern South Dakota and southern Minnesota
with some extending into southeastern North Dakota. A northeast wind
flow had developed over southeastern ND in response to the central
Plains storm. Meanwhile another low pressure center was over
southern Alberta with a trough extending south across eastern
Montana/Wyoming. Winds over western ND had become southerly today in
response to the western low/trough.

Regarding the central Plains to Great Lakes storm:
Tonight the central Plains low is forecast to lift northeast into
eastern Iowa by daybreak Monday, then continue towards the Great
Lakes by Monday evening. this is a slightly more eastward track than
yesterday`s models indicated. The precipitation shield from this
storm may just miss the Dickey and Lamoure County areas. Have taken
precipitation chances out of this area with this forecast package.

Regarding the western low/trough:
The upper level shortwave associated with this system will move
southeast out of Alberta tonight and approach the northwest corner
of North Dakota, then expand south across the western Dakotas on
Monday. The surface low will also move southeast, reaching
southeastern Saskatchewan by daybreak Monday, sweeping southeast
across North Dakota and arriving in eastern South Dakota by Monday
evening. Scattered showers are expected to develop over far
western North Dakota tonight, then expand and become more numerous
over western and central North Dakota on Monday. There should be
enough instability with this system for some isolated
thunderstorms from late morning through early evening. An upper
level jet streak will accompany this system, mainly across eastern
Montana and into northeastern Wyoming and western South Dakota.
Strong gusty northwest winds will develop behind the low/trough,
but the strongest winds should be west and south of our area.
Still - gusty northwest winds of 20 to 30 mph are expected over
southwestern North Dakota on Monday.

.LONG TERM...(Monday night through Sunday)
Issued at 320 PM CDT Sun Apr 30 2017

Cool with chances of showers early in the week, then dry with a
warming trend.

The eastern low moves northeastward slowly across the Great Lakes
Monday night, and continues lifting northeast towards Hudson Bay
Tuesday. Meanwhile farther west across the Northern Plains, a
northwest flow aloft remains in place. A few shortwaves in the
northwest flow aloft will keep conditions a bit cooler with chances
of showers in our area through Wednesday.

A building western ridge begins expanding into the Northern Plains
beginning Thursday, bringing a warming trend with dry weather
Thursday into next weekend. The western ridge elongates and builds
well north into north central Canada by Saturday/Sunday. Meanwhile
another west coast trough develops and begins moving east across the
Rockies late in the weekend. We may see a return of showers and
thunderstorms by Sunday/Sunday night.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1218 PM CDT Sun Apr 30 2017

VFR cigs/vsbys this taf period. Expect an increase in low to mid
level clouds (5kft-10kft) from west to east tonight. Areas of MVFR
cigs and scattered showers move into the west after 12 UTC Monday.
Added a scattered mvfr and VCSH at KISN at 16 UTC Monday.




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