Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 161114
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
614 AM CDT Sun Apr 16 2017

.UPDATE...For 12z Aviation discussion below

&&

.SHORT TERM...(Today and tonight)
Issued at 320 AM CDT Sun Apr 16 2017

The main concerns in the short term are fire weather-related
today (see Fire Weather discussion section below), and
precipitation-related tonight.

Skies continue to clear overnight in the wake of the cold frontal
passage. Northwest winds will be on the increase this morning in
the wake of said front, with speeds at 15-20 gusting to 30-35 mph
by the afternoon. Sufficient mixing should yield highs in the low/mid
60s.

Tonight we see a northern stream shortwave pivot from Southern
Manitoba to the Great Lakes, with a weak surface trough passing
across the area. The lift will certainly have some dry lower
levels to overcome, with cloud bases on the majority of the
soundings looking to be around 8000 ft. However, several of the
CAMS models and the Canadian are now indicating this dry layer may
be overcome. Given the newness of this idea, have increased pops
but kept the precip mention at sprinkles for now in the 03z-09z
Monday time frame.

.LONG TERM...(Monday through Saturday)
Issued at 320 AM CDT Sun Apr 16 2017

The fast, progressive, west to east flow, will continue through most
of this week providing a chance of precipitation for late
Monday/Tuesday, and again late Wednesday/Thursday. Differences in
the models occur with Wednesday/Thursday system which could extend
the precipitation chances longer into Thursday/Friday. Past Friday,
the pattern changes to a more northwest flow which is cooler but
drier for the Upper Midwest.

The system for late Monday night/Tuesday is much faster and further
north then in previous model runs which leads to a quick chance of
precipitation early Tuesday, compared to holding onto the
precipitation through Tuesday evening. The bulk of the precipitation
late Monday night/early Tuesday should be in central/northern
Minnesota where both the nose of the low level jet and short wave
energy resides. Further to the south across southern Minnesota,
there will probably be a narrow band of convection Tuesday morning,
and into Tuesday afternoon which will move quickly from southwest to
northeast.

Timing on the next system still remains on track for Wednesday
afternoon, through Thursday morning. However, there are differences
on how the models phase two short waves moving across the Northern
Plains, Upper Midwest Thursday morning. The EC is much more
progressive with the southern wave and keeps both waves separate and
leads to precipitation ending sooner. The GFS/MPAS/GEM are similar
with a phasing of the two waves. The phasing keeps the system(s)
moving slower and deeper. Therefore, holding onto the precipitation
through Thursday evening. These differences lead to a lower
confidence on timing and when the precipitation ends. In addition,
this will have an affect on temperatures as a cold rain vs. partly
cloudy skies Thursday afternoon.

At least the models are fairly similar past Friday with a strong
storm system digging southwest across the Rockies, and into the
Plains next weekend. This region should be dry but cooler with a
northerly flow.

There is also a chance of a freeze/frost Friday morning. Although
most farmers has not started planting in the Upper Midwest, outdoor
plants and those who have planted their local garden should be aware
of a potential frost/freeze Friday morning. It is too early to be
worried, but those who have begun to plant should keep an eye on the
forecast this week.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 614 AM CDT Sun Apr 16 2017

VFR conditions are expected through the period. Skies will be
mostly sunny today, then a bkn-ovc mid level deck moves across
the area this evening and tonight attendant with a weak trough of
low pressure. We could see a few sprinkles with the deck, but
measurable precipitation is not expected at this time.
West/northwest winds will increase to 15-20kts with gusts to
between 25-30kts by 17z. Gusts diminish around 01z.

KMSP...
No additional concerns.

/OUTLOOK FOR KMSP/
Mon night...VFR. Wind SE at 5-10kt.
Tue...MVFR and -RA with IFR/TSRA possible. Wind SSW at 10G20kt.
Wed...VFR with -RA/MVFR Cigs possible PM. Wind ENE at 10G15kt.
Thu...VFR with -RA/MVFR Cigs possible AM. Wind N at 10kt.

&&

.FIRE WEATHER...(Today and Tonight)
Issued at 320 AM CDT Sun Apr 16 2017

Northwest winds will be on the increase this morning in
the wake of a cold front, with speeds at 15-20 gusting to 30-35
mph by the afternoon. Ample mixing and drying in the low levels
will result in relative humidity values dipping to between 20 and
25 percent across western Minnesota this afternoon. These factors
will combine to created an elevated fire weather risk. Have issued
a Red Flag Warning for Noon to 8 pm when winds look to be brisk.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...Red Flag Warning from noon today to 8 PM CDT this evening for
     MNZ041>043-047>050-054>058-064-065-073-074.

&&

$$

SHORT TERM...LS
LONG TERM...JLT
AVIATION...LS
FIRE WEATHER...LS



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