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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
607 am CDT Wednesday Jul 1 2015

Short term...(today and tonight)
issued at 356 am CDT Wednesday Jul 1 2015

Early this morning...surface high pressures was pushing into
Wisconsin from the north...with dry air and low dew points
reaching western WI and eastern Minnesota. It was a different story
across western Minnesota. An area of showers were just crossing the Minnesota/ND
border at 3am. The baroclinic zone setup primarily through the
eastern Dakotas...but the showers extend further north than
previously anticipated. With the trajectory they are on...was
forced to increase probability of precipitation across west central Minnesota...mainly bringing
the low probability of precipitation further east. Much of the guidance is not handling
this situation well. The hrrr and the rap however have latched on
to the idea of rain about 50 miles east of previous forecasts. The
problem through is the dry air to the east. I didn't bring the
probability of precipitation as far west as the rap would indicate...as I anticipate this
area of showers to begin crumbling on its eastern edge as it hits
the dry air...and outruns the forcing to the west. Probability of precipitation will
linger across far western Minnesota as the wave works through the area
today...and diminish late this afternoon...before probability of precipitation increase
again in western Minnesota ahead of the next wave to arrive early
tomorrow morning.

As for temperatures...highs will be cooler than normal today...with
middle 70s expected. Conditions wont feel quite as humid as they have
recently...with the high brining dew points down into the upper
40s and lower 50s. Lows tonight will fall into the 50s...and
possibly some upper 40s the northern portion of west central WI.

Long term...(thursday through tuesday)
issued at 356 am CDT Wednesday Jul 1 2015

The northwest flow pattern aloft across the upper Mississippi
Valley region will be with US a few more days before becoming
more westerly this weekend and continuing early next week. There
will be a minor wave moving southeast in this flow pattern at the
start of the long term. Therefore...chance probability of precipitation were continued
for west central and southwest Minnesota Thursday and Thursday
night with dry weather elsewhere.

Thereafter...Friday and the Fourth of July look dry as the flow
aloft begins to transition to a more westerly flow. This change
is the result of a deep upper low prognosticated to pass across central
Canada through early next week. The attendant short wave will
drive a cold front across Minnesota and Wisconsin from Sunday
night through Monday. This is really the only significant period
for precipitation in the longer term. One thing observed with the
00z runs of the GFS and European model (ecmwf) is that the European model (ecmwf) has slowed the
frontal passage across our forecast area and is now nearly in step with the
GFS. This timing would have the front into northwest Minnesota Sunday
evening...reaching the Twin Cities around daybreak Monday and
passing east of Eau Claire Monday afternoon. With the two
solutions in agreement on this scenario...expanded the likely
probability of precipitation from south central Minnesota up through the Twin Cities and into
western Wisconsin for Sunday night. Current severe weather
parameters from the GFS would indicate the potential for a few
strong to severe storms Sunday evening/night across west central
into central Minnesota.

In the wake of the front on Monday...high pressure along with much
less humid air will spread in for Monday night through Wednesday.
Surface dew points could be in the 45 to 50 degree range on
Tuesday.

As for high temperatures...some upward modification was made to
highs for Saturday and Sunday to more closely match the European model (ecmwf)
guidance. This would suggest highs in the middle 80s versus the
lower 80s from the extended guidance. The higher temperatures are
easily supported with the 16 to 18 degree c 850mb temperatures. In
fact...sundays highs could be even higher ahead of the front as
850 temperatures of 20 degree c push into west central and southwest
Minnesota.

&&

Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 603 am CDT Wednesday Jul 1 2015

VFR expected throughout. Only concern is for light rain in western
Minnesota...possibly grazing St. Cloud from the west. Still...ceilings
and visible should remain VFR. Winds will remain relatively light and
out of the east or east-southeast.

Kmsp...expecting the precipitation to remain just west of the metropolitan as
dry easterly flow helps US stay dry.

/Outlook for kmsp/
Thursday...VFR with slight chance MVFR -tsra. Winds southeast at 5-10 kts.
Friday...VFR with slight chance MVFR -tsra. Winds west-southwest 5-10 kts.
Sat...VFR. Winds SW 5-10 kts.

&&

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

$$

Short term...speed
long term...rah
aviation...speed

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