Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 262013
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
313 PM CDT FRI AUG 26 2016

.SHORT TERM...(This evening through Saturday)
Issued at 312 PM CDT Fri Aug 26 2016

The short term concern remains rain shower/isolated thunder threat
over the far west and south later tonight into Saturday.

The deterministic model have come into better agreement with
developing/lifting a shot of rain across northeast Iowa/southeast
Minnesota mainly after 06z Saturday. Best forcing moves over this
region overnight. The NAM still looks too developed with its surface
low and lifts the rain shield too far to the north. Still...we see
some isentropic lift moving over the southeast third of the cwa into
Saturday morning...so we cant remove all pops. We decreased pops
overall to mid range chance for now. We may be able to decrease
more...especially into central MN for the overnight...as the drier
air remains in place.  Expect lowering cigs later tonight as
well...with a mostly cloudy trend expected.

As the upper trough approaches the northwest cwa Saturday
afternoon...we should see increasing threat for thunderstorms into
the afternoon.  MLCAPE increases into around 1200 j/kg with 50-60kts
of deep layer shear as the trough moves in. Steep mid level
lapse rates also return to that region...and a few CAMS were
indicating a squall line of storms developing along the front.
If heating/destabilization is maximized in the afternoon...severe
thunderstorms will be possible with the main threats damaging
winds and hail.

.LONG TERM...(Saturday night through Friday)
Issued at 312 PM CDT Fri Aug 26 2016

Semi-zonal flow kicks off the extended forecast, and then next week
closes with a mid/upper ridge centered across the Nation`s mid-
section with troughs on the coasts. This will make timing of
precipitation tricky, with fleeting chances gracing much of the long
term period.

Showers and thunderstorms will diminish Saturday night as the
shortwave lifts to Lake Superior. Expect Sunday to start out dry,
but then a warm front will lift north across central MN and west
central WI. There does not appear to be much in the way of forcing
aloft, but surface instability could pose a severe weather threat,
including for tornadoes.

20-30 pops are then found through much of the work week as a
cold front becomes stationary and then lifts back north as a warm
front. The aforementioned ridge will translate to near to slightly
above normal temperatures, along with a return of the elevated
humidity.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1150 AM CDT Fri Aug 26 2016

Models slowing initial surge of moisture into the region tonight.
Will limit development to the west and far south after 06z and
into keau-kmsp region 01z-12z. Models best shot of rain/moderate
looks to move across the keau region into Saturday morning. Could
see some thunder there but appears little instability elsewhere
through 18z Sat at least. Will drop cigs to mvfr over the
southeast areas area well as deeper moisture arrives. Should see
lowering cigs over the west and central but expect them to remain
vfr at this time. Light winds will become more east-southeast as
surface high departs to the east.

KMSP...Rain threat appears to be decreasing as several models
suggesting heavier threat remaining to the southeast of the field.
It should remain close enough to continue to mention -ra for a
period Saturday morning. We do expect some lowering
cigs...perhaps mvfr for a period as the rain/lower level moisture
lifts through. Thunder threat low enough to leave out of taf at
this time. Light winds becoming more east and then southeast into
Saturday.

/OUTLOOK FOR KMSP/
Sat nite...VFR. Slgt Chance MVFR TSRA in the evening. Wind E-SE
5-10 kts.
Sun...VFR. Wind S-SW 5-10 kts.
Mon...VFR. Wind S 5-10 kts.


&&

.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&

$$

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



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