Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 240924

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
424 AM CDT SUN JUL 24 2016

.SHORT TERM...(Today and tonight)
Issued at 424 AM CDT Sun Jul 24 2016

A cold front had pushed passed MSP at 4 am and will sweep across
our WI FA before daybreak. Showers and thunderstorms were confined
to areas of west central WI to the north of I-94 through daybreak
with any lingering showers ending by 14z near Ladysmith. The
balance of Sunday will be dry as high pressure begins building in
from the Western High Plains.

The main concern in the short term surrounds the high
temperature forecast for today. Mix-down from 825 mb shows highs
in the mid 80s from west central MN through the Twin Cities
to Eau Claire with lower 80s to the north. This agrees with
output from various MOS products. However, mix-down indicates
highs more in the upper 80s near the I-90 corridor. This does not
agree very well with MOS nor bias corrected guidance which
suggests highs only around 80, which is only about 5 degrees from
where readings are early this morning. For the forecast, went with
a blend with more emphasis on the bias corrected guidance which
yielded highs in the lower 80s.

Nice night tonight as the high pressure system settles overhead by
daybreak Monday. Lows in the upper 50s to lower 60s were continued
with middle 60s in the Twin Cities.

.LONG TERM...(Monday through Saturday)
Issued at 424 AM CDT Sun Jul 24 2016

Next week will be dominated a split zonal flow, temperatures near
normal, and on and off chances for showers and thunderstorms, though
chances for severe weather or excessive rainfall look low.

The long term will start with a beautiful day Monday as high
pressure slides across the area, with sunny skies dominating. We
begin to see return flow setup Monday night, but the models have
continued to trend showing the llj going up through SoDak and
curling up into the Red River Valley, with precip chances remaining
west and northwest of the MPX CWA Monday night. In fact, the models
are continuing to slow down when the next weak boundary arrives,
with most of Tuesday looking dry as well, with rain chances not
starting to pickup a bit more until Tuesday night. After Tuesday
night, we get into a rather dirty zonal flow through Saturday that
will be turning toward the NW with time. During this period, in each
12 hour day/night period you can find a model that is dry and one
that would produce scattered precipitation, which results in the
continuous chance pops from Tuesday night through Saturday. Though
through this time, the greatest coverage shows up in the afternoon
periods, indicating most of what we see next week will be diurnally
driven. In addition, a general decrease in shower coverage is
expected the deeper into the week we get as persistent northeast
flow from a high centered to the north of Lake Superior will result
in continuously drier low level air coming down from the northeast.
Forcing with any one of the waves is weak, there are really no
strong llj signatures, and MUCAPE is generally under 2k j/kg, so we
are not expecting much in the way of severe weather.

Given the zonal flow, we will see no significant pushes of warm or cold
air or moist or dry air, so temperatures near normal are expected
with dewpoints remaining in the 60s. Model spread for temperature is
not all that great, so stayed with blended guidance.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1229 am CDT Sun Jul 24 2016

TSRA ahead of cold front in western MN are moving east near 25
knots. Storms will likely accelerate a little bit over the next
few hours as the cold front picks up speed. one to two hour tempo
groups included for sites ahead of the storms. Ceilings are low
MVFR to IFR ahead of the front and will remain that way until a
few hours after frontal passage. Sites the worst off are KRNH and
KEAU which may take until mid morning to improve to VFR. Winds
becoming NW with fropa with speeds of 10-12 knots for the mid
morning and afternoon hours along with gusts to 20 knots or so.
Diminishing wind early Sunday evening.

KMSP...TSRA moving through the Twin Cities between 08-09z. Wind
gusts up 35 knots possible with the storms. Low MVFR ceilings
will likely become IFR for a time early this morning due to the
very moist low level conditions ahead of the front. Improvement to
VFR by daybreak with increasing NW winds from mid morning on.

Mon...VFR. Winds NW 5-10 kt.
Tue...VFR. Chance p.m. TSRA. Winds SW 7-10 kts.
Wed...VFR. Chance TSRA. Winds SE 5 kts.


.MPX Watches/Warnings/Advisories...


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