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Area forecast discussion 
National Weather Service Grand Forks ND
1239 PM CDT Sat Apr 25 2015

Update...
issued at 1239 PM CDT Sat Apr 25 2015

Clouds have been faster to clear out...with the clearing line
reaching the northern Red River valley. Adjusted skies to make the
northeastern and north central County Warning Area partly cloudy and move the
cloudiness a bit further west throughout the afternoon. Temperatures in
the northeastern County Warning Area have already reached the middle 50s so bumped up
highs a bit to the 60 mark.

Update issued at 946 am CDT Sat Apr 25 2015

Adjusted clouds as there has been some clearing in the
northeastern counties and a little in the far northwest. Drier air
will be moving in and what little fog there was in the west has
dissipated. For now will keep temperatures as they are with highs in the
50s but may have to adjust for the noon update depending on
clouds.

Update issued at 659 am CDT Sat Apr 25 2015

A low stratus deck will persist through the morning. Models
continue to indicate that drier air over Ontario/northern Great
Lakes will begin to advect towards northwest Minnesota this afternoon as the
upper low over NE Kansas this morning shifts east and ridging builds
over the area. Will not make any changes right now...but how fast
clearing occurs from the east will be the main challenge through
the day...and associated temperature trends.

&&

Short term...(today through sunday)
issued at 330 am CDT Sat Apr 25 2015

A benign...low impact weather regime will persist during the short
term period. A widespread area of low clouds is expected to
remain through much of the day within low-level easterly flow. Most
short term guidance...including the NAM/rap...start to erode the
cloud deck over northwest Minnesota this afternoon...with clearing
spreading westward tonight. Not sure exactly how quickly this
process will occur though. Assuming clouds persist much of the
day...temperatures may rise only modestly...even with the relatively mild
start to the day. For that reason...kept highs mainly in the low
to middle 50s. Tonight temperatures likely will be coolest over parts of northwest
Minnesota...possibly into the upper 20s...with skies expected to be
clear...while more clouds farther west may keep temperatures up a bit
higher.

On Sunday...models suggest a band of showers over central/western
ND near a surface boundary in association with an upper shortwave
trough lifting across Saskatchewan. With downstream ridging and a
very dry column to the east...do not expect much eastward progress
of the precipitation during the day. Although low level thermal profiles
do not warm considerably from today...more sunshine along with the
dry air mass should allow for temperatures to warm into the 60s in many
areas.

Long term...(sunday night through friday)
issued at 330 am CDT Sat Apr 25 2015

Models have consistently indicated that another shortwave trough
will move rather slowly east and southeast Sun night through
early week into the North Plains as upper ridging develops to the
west. The surface trough and associated band of showers will slowly
push east during this time aided by the upper wave. There are
still timing differences with regard to precipitation chances...with the
NAM/GFS slower than the Gem/ECMWF. Without a significant influx of
moisture and an initially dry air mass...it may take some time for
the atmosphere to moisten. For now kept probability of precipitation highest over the
Devils Lake basin Monday...with lower chance probability of precipitation eastward into
Monday night when timing differences become magnified. Highs on
Monday could be well into the 60s...but the timing of the boundary
and showers will impact temperatures.

Tuesday-Friday...00z models indicate a departing upper trough to
begin the period...with a building upper ridge for the remainder of
the period. Strength of this ridge uncertain as the GFS and Gem are
stronger with any upper waves riding well north of the region. The
European model (ecmwf) is a bit weaker allowing upper waves to ride through the
region Thursday and Friday. Temperatures will be much warmer...and
likely above normal values. The main question will be how much above
normal.

&&

Aviation...(for the 18z tafs through 18z Sunday afternoon)
issued at 1239 PM CDT Sat Apr 25 2015

Observations show MVFR ceilings west of the Red River valley. VFR
conditions will spread across the rest of the area by 21-00z from
east to west...as surface high pressure builds south out of Ontario
bringing drier air along with it. Winds will continue to be from the
east to southeast at 5 to 15 kts through the period.

&&

Fgf watches/warnings/advisories...
ND...none.
Minnesota...none.
&&

$$

Update...Jr
short term...jm
long term...tg/jm
aviation...Hopkins

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