Area Forecast Discussion
Issued by NWS Twin Cities, MN
FXUS63 KMPX 311210 AAA
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
710 AM CDT TUE MAY 31 2016
.SHORT TERM...(Today and tonight)
Issued at 330 AM CDT Tue May 31 2016
A band of showers and decaying thunderstorms across western
Minnesota will continue tracking east this morning. Lightning
activity has decreased significantly in the last couple hours with a
stabilizing atmosphere. Still, a large area of moderate rain will
make for a wet morning across the county warning area. The rain will
likely break up across eastern Minnesota and western Wisconsin later
Surface low pressure currently over southeastern North Dakota will
lift north then retrograde westward along the Canadian border this
afternoon. This will slow the cold front`s eastward progression into
Wisconsin, and as the atmosphere destabilizes again, a regeneration
of showers and thunderstorms from south central Minnesota to western
and northern Wisconsin is expected. The greatest chance will be east
of a line from Fairmont, to Mankato, St Paul, and Mora. The main
threat with these storms will be heavy rainfall from training cells
and seasonably high pwats around an inch and a half. The activity
will linger well into this evening across western Wisconsin while
the dry slot brings clearing skies to the west.
.LONG TERM...(Wednesday through Monday)
Issued at 330 AM CDT Tue May 31 2016
Longer term issues are timing of frontal exit wednesday morning
and wraparound shower potential over the northern cwa wednesday.
then development of next trough Thursday night/Friday with
cooling trend lingering into the weekend.
Initially...deterministic runs suggest front will have exited the
cwa by by 12z wednesday. Threat of instability showers under the
upper low continues and will hold any pop mainly along and north
of I-94. Cooler air drops into the area wednesday along with lower
clouds. This is expected to limit overall warming during the day
with highs struggling to warm through the 60s in the cloudier
northern cwa. Clearing trend is expected Wednesday night with
surface high spreading into the west. Winds should diminish and
with cool overnight lows.
Return flow and waa patten ahead of the nest trough will develop
mid clouds and the threat of showers/thunder Thursday night. We
confined the threat to mainly along and south of the MN river
valley for now. Both the GFS and ECMWF drop the next trough into
the region Friday and Friday night. Timing of trough brings the
system into the cwa during the day Friday...during peak heating.
Model instability increases modestly along with deep layer
shear...so appears there will some threat of strong/severe storms
Friday into Friday for the area.
Following the front...the upper low develops over the great lakes
region. The GFS has trended like an earlier ECMWF run...more
amplified and slower moving the closed low east. Both suggest
chance of showers/thunder both days as the system exits slowly to
the east. The below normal temperature trend should linger into
early next week.
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 710 AM CDT Tue May 31 2016
A band of showers continues to slowly trek east across Minnesota
this morning. Amounts and intensity will be light generally, with
pockets of heavier rain and maybe a thunderstorm or two through
16-18Z. Instability will build this afternoon as the cold front
pushes east into eastern MN and western WI when intensity will
increase and thunderstorms become more numerous - mainly south and
east of MSP. MVFR cigs across western MN should remain in those
locations for the next several hours with VFR conditions expected
elsewhere outside thunderstorms.
KMSP...Showers are finally beginning to approach from the south.
Amounts are expected to be quite light and rain will be
intermittent, so opted for VCSH as opposed to prevailing. There
will be additional development this afternoon, but it currently
looks likely this will be south and east of the terminal.
/OUTLOOK FOR KMSP/
WED...VFR. Isolated SHRA/TSRA. West wind 10 to 15 knots.
THU...VFR. West-Northwest wind 5 to 10 knots.
FRI...VFR. TSRA likely with chc MVFR. South wind 5 to 10 knots.