Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 181658
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1058 AM CST Sat Nov 18 2017

.UPDATED for 18z taf discussion below...

&&

.SHORT TERM...(Today and tonight)
Issued at 358 AM CST Sat Nov 18 2017

Northwest flow in the wake of the cold front will yield a
relatively cold day with below normal temperatures and brisk
winds. Highs will be around 5 degrees below normal, ranging from
the upper 20s to mid 30s. Low clouds generally along and east of
the I35 corridor will gradually shift east by early afternoon.
Expect some scattered-broken cumulus cloud development this
afternoon, and then we clear out tonight with subsiding winds.
Lows tonight will be in the teens area-wide.

.LONG TERM...(Sunday through Friday)
Issued at 358 AM CST Sat Nov 18 2017

No significant changes in the long term with dry weather expected
to prevail through Friday, while temperatures hop on the roller
coaster with a mild day expected Monday, cool days
Tuesday/Wednesday, back to mild air Thanksgiving Day/Friday,
followed by a cold finish to the holiday weekend. Only changes
made to the initialized forecast blend were to increase wind
speeds Monday night/Tuesday and boost highs around 5 degrees for
Friday.

First system of significance comes Monday as 988mb low tracks across
southern Canada.  This will draw mild air back into the region
beginning Sunday afternoon, though we won`t really notice it until
Monday. Unlike the last two surges of warm air we saw Tuesday and
again Friday, the low levels are expected to remain dry this time
around, with dewpoints remaining in the 20s. So no stratus this time
around, instead, we should see a good deal of sunshine until
mid/upper clouds begin to increase from the northwest. We currently
have highs into the low 50s forecast up to the MN River, though a
high hitting or exceeding the 50 mark is still in the realm of
possibilities for the Twin Cities.

Monday night, the bottom looks to fall out with temperatures as
strong CAA kicks in behind a cold front. Isallobaric high with this
front is quite impressive and winds gusting to between 40 and 50 mph
are possible Monday night into Tuesday morning. For winds Monday
night/Tuesday, nudged speed forecast toward the CONSMOS, which
verifies better than the SuperBlend in situations like this. 925-580
temps Tuesday are also forecast to bottom out around -12C, so
temperatures Tuesday will remain pretty steady from what we see for
morning lows. We will have a ridge axis over us Wednesday morning
with mainly clear skies expected, so it will be a chilly start to
Wednesday, with lows in the single digits and teens expected. Though
we will see WAA kicking in by the afternoon as WSW winds develop,
the chilly start will keep highs Wednesday around 10 degrees below
normal.

Thursday and Friday, upper ridging building in from the west, will
bring another push of mild air with. Still discrepancies on how
quickly the warm air returns Thursday, but by Friday, we look to
have very warm air over the area. Mixing down from just 950mb on the
GFS yielded highs ranging from the upper 40s near Ladysmith to the
low 60s in the upper MN River Valley. This is about 10-15 degrees
warmer than what SuperBlend had, which is being held down by MOS
guidance. Given 925-850 temps, mainly sunny skies, and favorable
southwest winds, 18.00 models definitely support near record highs
for Black Friday. However, this is still a weak out and a lot could
still change with the timing of this thermal ridge, so went a bit
more conservative with highs for Friday, but did get them closer to
the CONSRAW values. The roughly 5 degree increase in highs for
Friday brought our forecast up to near the mid point of the model
spread, as opposed to being down in the lower quarter of guidance.

Behind this system, much colder air comes back to finish the holiday
weekend. Along this baroclinic zone Friday night is also where you
will find the only precip generated in the models over the next 10
days with the GFS, though the ECMWF/Canadian have nothing.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1100 AM CST Sat Nov 18 2017

Main concern is extent of cloud cover this afternoon and mvfr cigs
trends. Those mvfr cigs to the east remain near KEAU and will
continue for a couple hours before breaking out. Then question
remains what sort of redevelopment will take place during the
afternoon and if mvfr cigs develop again. Some potential of this
into west central WI. Will trend just above mvfr for now. Clouds
to the west 3-4K feet will work east this afternoon affecting most
taf sites. Then clearing into tonight with high clouds moving in
Sunday. Gusty northwest winds to 27kts likely this afternoon and
hen diminishing overnight becoming sw.

KMSP...Few-sct 35-4500 feet clouds possible into the afternoon
with clearing into the evening and high clouds into Sunday. Gusty
northwest winds through the afternoon then become sw-s into
Sunday.

/OUTLOOK FOR KMSP/
SUN night...VFR. Winds S 5 kts.
MON...VFR. Winds SW 5-10 kts.
TUE...Chc MVFR. Winds NW 15-20G30-35 kts.

&&

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

$$

SHORT TERM...LS
LONG TERM...MPG
AVIATION...DWE


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