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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
702 PM CDT sun Apr 19 2015

Short term...(this evening through monday)
issued at 420 PM CDT sun Apr 19 2015

Rain will become widespread by this evening east of I-35 as a potent
wave lifts north along the Mississippi Valley. Deformation band is
already becoming well defined from near Red Wing southwest into
Iowa. There are embedded echos above 40 dbz and think there is at
least some potential for thunder in the more intense banding/cells
through the evening. Frontogenesis strengthens during the evening
and a band of moderate to occasionally heavy rain will set up and
remain nearly stationary through the early overnight. As the wave
pushes into the Great Lakes...drier air will finally begin to head
east and the band will make slow eastward progression through middle
morning Monday. Total rainfall amounts of a half to one inch are
expected.

Upper low will rotate overhead Monday. Steep lapse rates should
allow scattered showers to develop by afternoon. A little sleet or
small hail may be possible with the more intense cells...but most
should not be of much significance.

The other story Monday will be strong northwest winds. Deep mixing
to 700 mb should be able to bring some 30-35 knots gusts to much of the
area from middle morning Onward...but should ease a bit by late
afternoon.

Long term...(monday night through sunday)
issued at 420 PM CDT sun Apr 19 2015

The main theme for the long term will be dry weather after Tuesday
with below normal temperatures.

Guidance is in good agreement with the overall evolution of the
weather pattern through Friday...but models begin to diverge over
the weekend.

The two distinct waves visible on water vapor imagery moving across
nodak and Missouri this afternoon are still expected to phase with
each other over the western Great Lakes on Monday...with the
resultant closed 500 mb low slowly working from Western Lake Superior on
Monday to New England/Quebec on Friday. Over the weekend...the
European model (ecmwf)/GFS continue to differ on how far west this upper low will
stretch...with the GFS keeping it clear back into NE Minnesota...while the
European model (ecmwf) continues to build a ridge in this weekend...with a western trough
trying to moving across the plains as well. At either rate...we will
be spending much of the week on the west side of the expansive upper
low within its convergence region...which means lots of dry Canadian
high pressure is heading our way. The NE half of the County Warning Area will still
be within the moist cyclonic flow around the upper low on Tuesday to
see more scattered-numerous diurnally driven showers...but after
that...dry surface high pressure takes over and it looks to keep US dry
through the weekend.

Being on the western side of the upper low will also keep US well below
normal for temperatures next week as we get back into strong northwest
flow. Did nudge highs down a few degrees on Tuesday...especially for
the NE third or so of the area...where extensive cloud cover will
help hold highs in the lower 40s. The ECMWF/GFS...show the cold
pocket at 850 mb with temperatures below 0c remaining overhead through the
course of the work week...which will keep highs a good 10 degrees
below normal. Even though the European model (ecmwf) shows upper ridging moving in
this weekend...it does not warm the low levels much over what the
GFS has...so in all likelihood we will not see highs topping 60
again until next work week. Incidentally...today is the first day in
which the average high for msp is 60 degrees.

&&

Aviation...(for the 00z tafs through 00z Monday evening)
issued at 702 PM CDT sun Apr 19 2015

Rain will slowly move from west to east across far eastern Minnesota and
western WI this evening. MVFR ceilings are likely through the
night...but a few breaks as clouds scatter to VFR. The winds ramp
up out of the northwest by morning.

Kmsp...
the ceiling has been hanging between 1700-2100ft for the past
60-90 minutes and the sub 2000ft stuff is due to the falling
rain...so that should improve when the rain moves to the east this
evening.

/Outlook for kmsp/
Tuesday...VFR. Winds northwest at 20g30kts.
Wednesday...VFR. Winds northwest at 15g25kts.
Thursday...VFR. Winds northwest 10-15kt.

&&

Fire weather...
issued at 420 PM CDT sun Apr 19 2015

Monday and Tuesday will see strong northwest winds develop to the
west of a deep area over low pressure that will be moving across
Michigan. The strongest winds area expected from west central
through south central Minnesota...where sustained winds on Monday will
increase to between 25 and 30 miles per hour with gusts to 40 miles per hour...with the
speed of the northwest winds only backing off about 5 miles per hour for
Tuesday. The cooler temperatures expected with these winds will
help keep humidities up in the 30s on Monday...but Tuesday
afternoon will see humidities fall to between 25 and 30
percent. If we end up a couple of degrees warmer than is currently
forecast...we could easily see humidities in the upper Minnesota River
Valley dip below 25 percent...so Tuesday will have to be monitored
closely in the next couple of days for the potential need for yet
another red flag warning.

&&

Mpx watches/warnings/advisories...
Minnesota...none.
WI...none.
&&

$$

Short term...borghoff
long term...mpg
aviation...clf
fire weather...mpg

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