Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 270252
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
952 PM CDT FRI AUG 26 2016

.UPDATE...
Issued at 950 PM CDT Fri Aug 26 2016

Based on current radar trends and latest high resolution model
guidance continued to delay higher chance pops into the FA until
after midnight. Any thunder potential looks to be closer to
sunrise.

UPDATE Issued at 653 PM CDT Fri Aug 26 2016

Current radar returns unimpressive and likely just sprinkles with
cigs aob 10k ft. Based on this and current HRRR guidance have cut
back on pops through mid evening. With lack of
instability/cape/shear have taken out thunder mention as well.

&&

.SHORT TERM...(This evening through Saturday)
Issued at 241 PM CDT Fri Aug 26 2016

Precip chances and strength will be the primary challenges for the
short term.

The main upper trough is still out over the Northern Rockies, but
water vapor loop shows a weak lead shortwave moving out through
SD. There is also some warm air advection over central SD and the
SPC meso page has a fair amount of 925mb frontogenesis aligned
with ongoing rain. The northern edge of the rain band is
approaching the southwestern counties, and the short range models
seem reasonable, with the southern counties seeing some rain this
afternoon. The band will spread north and eastward this evening as
frontogenesis lifts north, but it does seem there will be a
weakening trend. The main upper trough will begin to move into the
western Dakotas by the early morning hours, and another round of
showers quickly sets up from southwest to northeast across our
CWA. With the best MUCAPE staying to the west think that any
thunder overnight will be fairly isolated.

Tomorrow, the upper trough moves across the region as it lifts
into MN. Southerly winds will continue to bring moisture and some
warm air advection. Depending on how long morning showers hang on
the destabilization for the afternoon could be impacted. It seems
at this point that there will be at least some clearing in the
western counties and the NAM has some 1500-2000 J/kg in the
southwestern CWA. With deep layer bulk shear values around 30 to
40 kts, some strong to severe cells developing behind the main
rain band are not out of the question. The NSSL-WRF run shows this
solution fairly well. Any redevelopment will be fairly spotty so
included some low POPs a bit longer in the western CWA tomorrow
afternoon.

As for temperatures, tonight will not be as cool as last night
thanks to clouds and precip moving in so kept lows in the 50s.
Highs will be dependent on precip lingering, so have highs in the
east staying just below 70 degrees with locations further west
seeing low to mid 70s.

.LONG TERM...(Saturday night through Friday)
Issued at 241 PM CDT Fri Aug 26 2016

Decaying cells in the east associated with a fetch of gulf moisture
should dissipate and advect east of the area by 06Z Sunday, with sfc
flow turning SE during the day Sunday as an inverted trough moves
across the Dakotas. Mid aftn trough should be vcnty of Minot-
Dickinson and capped warm sector will not allow convection until 00Z
to 03Z Monday timeframe as warm frontal boundary sets up across the
southeastern CWA.  Significant variation between NAM and GFS POP
fields Sun night, with blended solution bringing scattered storms
and showers from the valley on east, which is influenced by the more
bullish NAM. Low confidence attm on exact location/timing of
convection/warm frontal boundary and will keep blended solution as
it best reflects continuity.

Sfc high and northerly flow returns for Monday and Tuesday and
majority of area should be dry.  Potential for an active second half
of the week, dependent on upper ridge shifting over eastern zones
and setting up a SW flow pattern aloft.  However, models and blended
solution seem to be a bit early on bringing scattered showers to
the region on Wed...with better confidence towards the end of
the work week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 653 PM CDT Fri Aug 26 2016

VFR conditions expected through the period. Better shra chances
look to be aft midnight although confidence not real high at this
point.


&&

.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&

$$

UPDATE...AV
SHORT TERM...JR
LONG TERM...Speicher
AVIATION...Voelker


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