Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 160415
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1115 PM CDT Wed Mar 15 2017

.SHORT TERM...(This evening through Thursday)
Issued at 300 PM CDT Wed Mar 15 2017

Early afternoon visible satellite imagery together with RAP13
surface analysis showed high pressure and clear skies across most of
Minnesota and Wisconsin. Despite the light winds, temperatures
warmed above freezing at most locations along and north of I-94,
with cooler temperatures near I-90 where there was more snow cover.

Over the next 24 hours the ridge of high pressure will shift
eastward and warm air advection will move from the Dakotas into
western MN and lead to isentropic ascent, mid level clouds, and some
light precipitation on Thursday. The narrow band of precip will only
be a few hundredths, but could see some mixed precipitation in the
morning across western Minnesota based on the thermal profiles.
Temperatures should warm close to 40 by Thursday afternoon as the
precipitation changes over to all rain.

.LONG TERM...(Thursday night through Wednesday)
Issued at 300 PM CDT Wed Mar 15 2017

The longer term concerns are timing of a couple of fast moving
fronts across the region and overall temperature trend.

Initial cold front sweeps across the region Thursday night into
Friday morning. We should see stratus lift into the cwa thursday
evening per trend of 0.5Km condensation pressure deficits on most
deterministic runs indicate saturation developing. SREF probs for
<3 and <1sm are quite high >60% ahead of this feature. Models are
not overall positive on QPF for the front...with any real chance
of measurable over the far eastern cwa Thursday night. Models
indicate could be a light mix...with surface temperatures forecast
close to freezing and an elevated warm layer associated.

Somewhat cooler air follows the front with a warming trend
expected into the weekend. Forecast highs will be determined by
the amount of snow cover that remains over the area. Much of it
should be gone by later Sunday. The next front is forecast to
move through Sunday night into Monday but models are trending dry
at the moment. The 12z ECMWF which remains more progressive and
weaker with the wave...as much of the energy rides north of the
cwa.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1115 PM CDT Wed Mar 15 2017

MVFR cigs moving into the Twin Cities now have held firm this
evening, so followed the idea of the RAP/NAM in taking these
clouds all the way into EAU by 12z. Outside of western WI, precip
potential looks to be on a downward trend, with dry low level air
looking to be a limiter. CAMS are pretty uniform in showing a
band of warm advective precip forming near the MN/WI border around
20/21z and moving east, clearing EAU shortly after 00z. Precip
mentions in TAFs are tied to what the CAMs are showing and think
the LAMP is too late in starting precip and overdoing it as well.
Low confidence on what will happen with cigs behind this precip
band. We`ll certainly be moistening up the low levels ahead of a
cold front that will be near an AXN/RWF line at the end of the
period. Followed a more optimistic NAM route for bringing low
cielings in. Again, the concern is the models are just overdoing
the amount of low level moisture coming in and with the low going
across southern Canada, the threat for low cigs will be better in
northern MN.

KMSP...MVFR cigs just moving in have lasted 2-3 hours at aiports
to the west, so they will be long gone by the time the morning
push starts, though around 4k foot cigs are expanding to the west
of them, so we may go from MVFR to lower end VFR cigs this
morning. Precip chances look much better east of MSP today, but
left the vcsh mention in there for when the warm advective band
comes through, may end up as just virga. Low confidence on cigs
tonight, but as the front apporaches (early Friday morning FROPA),
the low levels should moisten, with low cigs developing again.

/OUTLOOK FOR KMSP/
Fri...MVFR/-SHRA possible early, then VFR. Wind NW at 10g25kt.
Sat...VFR. Wind NW at 10kt.
Sun...VFR with MVFR possible. Wind S at 15g25kt.

&&

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

$$

SHORT TERM...JRB
LONG TERM...DWE
AVIATION...MPG



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