Scientific Forecaster Discussion
fxus63 kmpx 292017
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
317 PM CDT Wed Mar 29 2017
Short term...(this evening through thursday)
issued at 318 PM CDT Wed Mar 29 2017
Water vapor imagery clearly illustrates the upper low rotating
over central/eastern Oklahoma this afternoon, with ample moisture
streaming northward into the area. Measurable precipitation on
radar imagery correlates with isentropic upglide on the 295k
surface. This area of lift will shift gradually north and east
through the evening hours toward east central Minnesota and west central
Overnight, as colder air works into the area and the column cools,
we could see some light snow mixing in, primarily over west
On Thursday, the upper circulation meanders across Iowa and
Missouri. This will mean a prolonged chance of light rain for the
far south and east (southern Minnesota toward eau claire). By Thursday
eve, locations in far south central and southeast Minnesota could see 24
hour rain totals in the one half to three quarter inch range.
Temperatures will lower into the low/mid 30s tonight, with lower
40s to lower 50s common for highs. Winds have been a bit stronger
in the south than models were projecting, so have increased speeds
a bit. Do expect some gusts into the the mid/upper teens (knots).
Long term...(thursday night through wednesday)
issued at 318 PM CDT Wed Mar 29 2017
By Thursday evening, most of the precipitation should have ended
across southeast Minnesota. Lingering clouds across the southeast
one half of mpx forecast area should remain due to moisture/cyclonic
flow from the departing upper low. Slowly, as the system departs
Friday/Friday night, a ridge of high pressure will provide a couple
of days of dry and mostly sunny conditions. Temperatures should
rebound from the 40s and lower 50s, to the mid to upper 50s by
The extended period remains progressive as the continued fetch of
wave, after wave, moves inland across the West Coast. The upper flow
pattern remains split in the mid section of the nation, with the
southern stream more active for the next 7 days. There are some
uncertainties on precipitation chances late in the weekend, and into
next week due to this split flow pattern. Therefore, past this
weekend, forecast confidence remains low on wet vs. Dry.
Temperatures should lean near to above normal with this type of
pattern, and a mostly Pacific type air mass regime.
Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1233 PM CDT Wed Mar 29 2017
The area of rain over southern Minnesota will continue inching north-
northeast throughout the afternoon and evening hours. Ceilings and
visibilities are expected to lower to MVFR as this occurs. Kaxn
and kstc should stay dry, but may also experience scattered MVFR
level clouds tonight. Given the light nature of the rain,
visibilities are not expected to go lower than 4sm. Some snow is
expected to mix in at Keau overnight, but the precip should stay
liquid at other sites. Winds will be from the east/southeast at
7-11 knots, with gusts developing on Thursday.
light rain is expected to arrive between 23z and 00z, with MVFR
ceilings possible after that through the overnight hours. The
current taf may be a bit optimistic with the cigs, and will need
to watch trends to see if an overcast MVFR deck looks to be prevalent
(for now have just included a tempo). The main window for light
rain looks to be between 00z and 08z, although drizzle cloud
linger through the morning push.
/Outlook for kmsp/
Fri...VFR. Wind NE 5-10 kts.
Sat...VFR. Wind variable less than 5 kts.
Sun...VFR. Wind south-southeast 5-10 kts.