Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
FXUS63 KMPX 222350

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
650 PM CDT Wed Mar 22 2017

.SHORT TERM...(This evening through Thursday)
Issued at 326 PM CDT Wed Mar 22 2017

A band of mid level clouds moved eastward across Minnesota this
morning and will enter western Wisconsin later this evening. Radar
returns showed precipitation across western MN, but metars showed
only light precip and nothing measurable, so transitioned light
pops to flurries and sprinkles overnight.

On Thursday a large upper level low that is currently moving onshore
the California coast will move across the 4-corners and become
cutoff from the main flow. Low level theta_e advection will lead to
saturation in the lowest 700 mb of the atmosphere and forecast
soundings show enough lift to produce some light rain. Have pops
increasing throughout the day on Thursday, but again little

.LONG TERM...(Thursday night through Wednesday)
Issued at 326 PM CDT Wed Mar 22 2017

The main focus of the long term period is the system set to impact
our area from tomorrow through the weekend.  By tomorrow evening,
the cut-off upper low will be positioned over the four corners
region with surface cyclogenesis ongoing across eastern Colorado.
The warm front will be draped across southern MN/northern IA and
into central WI tomorrow night and will be the focus for the
rainfall development given the strong low level convergence.

The latest trends with the forecast guidance indicates the heaviest
rain potential across far southern MN and northern IA.  The outlier
is the Canadian model which is much farther north.  The latest ECMWF
run shifted its QPF southward this morning, more in line with the
GFS.  In addition, the GEFS members indicate less than a 50% chance
of seeing an inch of rain north of Mankato.  With high pressure
pushing into the great lakes from the north during this period, tend
to lean toward the southern consensus.

This low will slowly move east across northern Oklahoma into
southern Missouri before finally turning northeast toward Chicago by
Sunday.  With that, we could see light precip lift back into the
region during this period.

Beyond that, the pattern looks to remain active with continued waves
moving through the center of the country.  Possibly additional
strong cut off lows moving through late in the period.  In terms of
temperatures, we look to run near to slightly above normal.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 645 PM CDT Wed Mar 22 2017

Midlevel cloud cover has increased from west to east over the
area. Despite radar returns showing precip over Central MN, dew
point depressions are still high and no precip has been recorded
at the surface. As more moisture is advected into the region, we
can expect ceiling heights to decrease through the day on Thursday
with chances for rain likely after 18Z Thursday.

Timing for rain showers has been delayed slightly since the 18Z
discussion. MVFR conditions are likely near 22Z due to the
decreasing cloud deck heights and anticipated rain showers.

Fri...MVFR with -RA likely. Chc IFR. Wind N 5-10 kts.
Sat...Chc MVFR -RA. Wind ENE 10-15 kts.
Sun...Chc MVFR -RA. Wind ENE 5 kts.




AVIATION...AMK is the U.S. government's official web portal to all federal, state and local government web resources and services.