Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KMPX 281108

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
608 AM CDT THU JUL 28 2016

.SHORT TERM...(Today and tonight)
Issued at 430 AM CDT Thu Jul 28 2016

A rather gloomy day is in store for today, with low clouds expected
to stick around most of the day from south central into eastern MN
and western WI. In fact, no substantial clearing is expected until
overnight when skies should begin to clear out from north to south,
though that clearing looks to only come to roughly the northern half
of the MPX area. For the southern half of the area, it will likely be
well into Friday before clouds finally break up. The reason for the
gloominess is that we find ourselves in a broad positively tilted
trough with several weak disturbances within it and we do not look
to fully cleanse ourselves of this trough until Sunday.

With clouds, it will also be cool and expect highs to only top out
in the upper 60s and lower 70s where low clouds dominate the day,
with some filtered sun allowing highs in the upper 70s to around 80
out in western MN.

Besides the low clouds, southeast MN and adjoining portions of WI
will have to deal with on and off light rain showers and drizzle
through the day. This is the result of a weak h7 low that will be
drifting from NW WI toward SE MN today. This h7 low will interact
with an inverted trough at the surface that will be extending up
from La Crosse to the Twin Cities, which will aid in the
shower/drizzle development through the day. Forecast soundings show
moist adiabatic soundings and little instability and reflectivity
forecasts produced by the CAMs struggle to produce any reflectivity
above 50 dbz, so removed any thunder mention from the forecast and
stuck with just a chance of shower wording.

.LONG TERM...(Friday through Wednesday)
Issued at 430 AM CDT Thu Jul 28 2016

Friday and Saturday will feature more sunshine than today, so we
expect a slow warming trend through the weekend, but near climate
normals. The time/height cross sections of relative humidity from
the 29.00/06Z guidance show very little moisture through the
depth of the atmosphere after today and for at least the first
half of the weekend. Although - fair weather cumulus are likely
given the cooler temperatures at 850mb. More moisture and warmer
temps begin to advect into MN/WI on Sunday, but the deeper
moisture and high humidity doesn`t return until Mon-Tue when a
surface low takes shape in the Central Plains and locally we get a
stronger S-SE flow regime. The next notable chance for rain
/potentially heavy/ looks to occur Monday night and Tuesday
morning near a warm front that will be stretched out across MN/WI.
The GFS/ECMWF have another wave passing through Wednesday night.
Overall big picture...a warm and moist pattern looks to be in
play next week.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 608 AM CDT Thu Jul 28 2016

Timing of low clouds is main concern today and followed a more GFS
trend for doing such, though with continued NE/E winds through
tonight, you can not completely rule out the much gloomier outlook
of the NAM, which would bring MVFR/IFR cigs back for MSP/RNH/EAU.
To go with these clouds, we will likely see some dz/-ra develop
this morning, but nothing widespread or long lasting.

KMSP...Pirep this morning says stratus over MSP is about 1500 ft
thick, so like the TAF has, it will take a while to clean out the
stratus today and there is potential it may not be until Friday
morning that we finally go free of sub-vfr stratus. If we see any
precip, it will come this morning and the form a brief period of
dz or -ra, no thunder is expected.

Fri...Chc MVFR early. Winds NE 5 kts.
Sat...VFR. Winds SE 5 kts.
Sun...VFR. Winds SE 5-10 kts.


.MPX Watches/Warnings/Advisories...


AVIATION...MPG is the U.S. government's official web portal to all federal, state and local government web resources and services.