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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
602 am CDT Friday Jul 25 2014

Updated for 12z aviation discussion...
issued at 556 am CDT Friday Jul 25 2014

&&

Short term...(today and tonight)
issued at 330 am CDT Friday Jul 25 2014

Early morning thunderstorms continued to develop across the region
this morning fueled by the veering winds associated with the theta_e
advection in connection with the low level jet. Over the next few
hours this 40kt jet will become more focused across southern...and
eventually southeastern Minnesota. As a result precipitation will continue
to develop for the next few hours...but should gradually wane
shortly after sunset as it enters western WI.

Earlier runs of the rap missed the precipitation that developed in
northeast South Dakota...so it is no surprise that highres models have been
struggling to get a handle on the two areas of precipitation that developed
earlier. As a result most of the runs have been all but discarded.
The 25.06hrrr has finally caught up and it supports the idea of
continued convection this morning...but with a weakening trend after
11z. The severe weather threat is very low given the deep stable
layer beneath the elevated cape...and only marginal 30-35kts of
effective shear.

Looking ahead...skies should clear behind the morning precipitation
yielding another muggy afternoon as dewpoints climb back to near
70f. Increased temperatures slightly across west of i35...and raised
dewpoints as well. Overnight northwesterly winds will push a cold
front through the region sending dewpoints back into the upper 50s
by Saturday morning.

Long term...(saturday through thursday)
issued at 330 am CDT Friday Jul 25 2014

The weekend starts out on a mild note...as the area remains
sandwiched between a southern Continental U.S. Ridge to the south...and a
middle level low to the north in Saskatchewan/Manitoba. The result will
be slightly warmer than normal highs in the middle 80s on
Saturday...followed by increasing precipitation chances into
Sunday as the aforementioned low drops south-southeast from
southern Manitoba. As is common with these types of
lows...precipitation chances appear the highest from central Minnesota
into WI...where forcing/moisture is deeper. Expect showers with
isolated thunderstorms on Sunday...particularly during the afternoon
hours as diurnal heating aids destabilization.

Next week starts out on a dry and mild note as the weekend low
shifts southeast and a broad surface ridge builds across the
central Continental U.S.. the local area remains crammed between western
ridging and eastern troughing at the middle to upper levels of the
atmosphere...yielding cooler than normal highs from Monday through
Wednesday mostly in the 70s...and lows in the 50s.

Thursday and Friday bring the next chance for measurable
precipitation as shortwave energy begins to trickle south on the
western periphery of the eastern Continental U.S. Trough. Chances are not
high at this point given modest forcing and moisture...but
sufficient for the inclusion of 20-30 probability of precipitation.

&&

Aviation...(for the 12z tafs through 12z Saturday morning)
issued at 556 am CDT Friday Jul 25 2014

Showers and thunderstorms will continue to weaken as them move
across the region this morning. Forecast guidance wants to show a
few low clouds across northwest Minnesota later today...but confidence is
too low to include in the taf at this time. Looking ahead...fog
should develop ahead of a cold front that is forecast to slowly
move across the region later today. The best chance for fog is
across the east at krnh and Keau.

Kmsp...
precipitation will be out of the region before 12z...with VFR conditions
expected throughout the period. Chance for fog is low at kmsp.

/Outlook for kmsp/
sun...VFR with MVFR/rain showers possible. Winds northwest at 10g15kts.
Monday...VFR. Winds north at 5kts.
Tuesday...VFR. Winds north at 10kts.

&&

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

$$

Short term...jrb
long term...ls
aviation...jrb

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