Area Forecast Discussion
Issued by NWS Twin Cities, MN

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484
FXUS63 KMPX 290838
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
338 AM CDT Wed Mar 29 2017

.SHORT TERM...(Today and tonight)
Issued at 338 AM CDT Wed Mar 29 2017

The main short term concern is rain development today...its timing
and extent as the upper low lifts east. Temperatures today are
conditional and will be determined on how thick the higher level
clouds will be into the afternoon.

Water vapor imagery showing upper circulation remains over the
southwest/New Mexico/Texas panhandle region. Broad south to
southwest flows remains with embedded convection ahead of the
system. Models lifts this moisture northeast during the day...to the
MN/IA border by afternoon and into the south metro by evening. We
increased likely PoPs coverage a bit farther north into the south
metro into the evening. Latest guidance had broad southeast flow
developing into the evening with 290K isentropic surface indicating
saturation developing.  We expect any precipitation to be light on
this northwest fringe of the main rain shield which will move across
the southeast portion of the cwa.

Cloud cover is expansive with convective debris for the central
plains convection transported north into the area.  This combined
with the northern stream trough should be enough to help thicken
clouds and generate the rain across mainly the eastern half of the
cwa. High temperatures today will be determined by the opaqueness
of the clouds cover...with a 60 again possible out west if the
cloud cover remains thin enough.

Colder temperatures will move into the area as the upper circulation
drifts east. This will drop thickness levels close to critical
values after 06z Thu...mainly to the far east. There could be a
rain/snow mix into a portion of west central Wisconsin then...but
little if any accumulation is expected.  QPF amounts could range
around 0.25 to 0.50 inches mainly across far south central Minnesota
during the event.

.LONG TERM...(Thursday through Tuesday)
Issued at 338 AM CDT Wed Mar 29 2017

The longer term period looks to be dominated by split flow across
the CONUS with a series of upper lows cutting off over the
southwest US, then meandering eastward with our area mainly north
of the best moisture and forcing. We`ll have some lingering light
precipitation across the southeast portion of the area early on
Thursday as the surface low moves through the Mid-Mississippi
Valley. A ridge of high pressure then looks to build in from the
north and keep things dry through Sunday. We look to get into some
weak return flow by Monday, but solutions have been trending drier
across our area with more robust large scale and convective
precipitation expected to the south with another surface low
moving from the plains through the Mississippi Valley. The ECMWF
has come more in line with a slightly more southern solution as
shown by the GFS and Canadian. Maintained some low PoPs from
Monday into Tuesday, as we could see a bit get wrung out as a weak
northern stream wave moves through the area. However, the bulk of
any significant precipitation looks to stay well to our south
during that time frame.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1043 PM CDT Tue Mar 28 2017

An organized low pressure system moving out of the OK/TX panhandle
region into the mid-Mississippi River Valley region through
tomorrow will drag a weak surface trough far north enough by late
tomorrow to potentially produce a few light rain showers in
southern MN into southwestern WI late tomorrow into tomorrow
evening. Therefore, VFR conditions will prevail through tomorrow
afternoon with gradually lowering ceilings as the day progresses,
mainly for eastern/southern MN into western WI. Chances are
growing for MVFR ceilings for KMPS eastward, particularly later
tomorrow evening. Light/variable winds overnight will become
easterly tomorrow in the 5-10 knot range.

KMSP...High confidence in VFR through tomorrow afternoon then, as
the trough approaches from the southwest, there is a growing
chance of MVFR ceilings tomorrow evening (potentially during or
just after the evening push). A few light rain showers are
possible but nothing that is expected to drop visibility below 6SM
at this point.

/OUTLOOK FOR KMSP/
Thu...VFR. Chc -RA. Wind E at 5-10 kts.
Fri...VFR. Wind NE 5-10 kts.
Sat...VFR. Wind variable less than 5 kts.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&

$$

SHORT TERM...DWE
LONG TERM...
AVIATION...JPC



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