NWS Forecast Discussion

FXUS63 KMPX 041033

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
533 AM CDT Sat Jul 4 2020

.UPDATE...For 12Z Aviation discussion below


.SHORT TERM...(Today through Sunday)
Issued at 317 AM CDT Sat Jul 4 2020

More of the same today, with continued hot weather under the
influence of the mid/upper ridge. High temperatures look to again
top out in the 88-92 degree range, although dewpoints look to mix
out into the low/mid 60s in most areas. This will keep us below
Heat Advisory criteria, with most spots seeing max heat indices
in the low 90s this afternoon. It will still feel hot and sticky
of course, but not as oppressive given the slightly reduced
dewpoints. A dry day can`t be promised for everyone, given the
potential for a scenario similar to Friday afternoon, in which
isolated thunderstorms developed. Despite it being hot at the
surface, there is only a slight warm nose aloft (700-600mb), which
would not be difficult to overcome as we reach peak heating. The
area most susceptible given the faint lift on the periphery of the
ridge is southeast/east central MN and west central WI.
Therefore, in addition to afternoon cumulus cloud development,
have added a mention of isolated PM thunderstorms there.

Once we lose the influence of daytime heating this evening, any
thunderstorms and cumulus clouds should dissipate. Fog
development tonight will be a slightly lesser concern, given
increasing southerly winds and a tad more in the way of cloud

Sunday`s weather looks to feature similar temperatures to
Saturday, although more organized showers and thunderstorms will
approach northern areas (central MN) during the afternoon as the
ridge begins to flatten. This will signal our transition to the
more active weather pattern advertised for next week.

.LONG TERM...(Sunday night through Friday)
Issued at 317 AM CDT Sat Jul 4 2020

If you wished for a reprieve from the warmth we`ve experienced
over the last few days, I`m sorry to say that doesn`t look to be
changing all that soon. The persistent ridge over us will finally
look to flatten a bit by Monday, giving us some brief zonal flow
in the mid to upper levels that will give us a chance for some
shortwave fired convection mainly Monday afternoon and evening.
Kept with the NBM for PoPs as there is still just too much
uncertainty to be entirely confident of a given outcome past
Monday, with the best looking day for storms being Thursday with a
more robust shortwave manifesting in both the GFS/ECMWF. QPF wise
our PWAT values lie in and around about 1.5, so nothing fantastic
but nothing to scoff at either. The main question will still just
be whether or not the forcing present is enough to produce
anything more than an isolated storm or two.

Temperatures are still looking to remain on the warm side through
the week, with highs lingering in the upper 80s to mid 90s
throughout the state. One positive sign with the 00Z GFS is a brief
return to northwesterly flow on Sunday, which if it holds could
finally bring us back closer to seasonal values in the mid 80s for
highs. We still have a lack of any significant synoptic systems
breaking our pattern, which is echoed in the CPC outlooks that
highly a very good chance for above normal temperatures to linger
through the first 2 to 3 weeks of the month.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 532 AM CDT Sat Jul 4 2020

VFR conditions are expected through the period. Cumulus cloud
development is expected again this afternoon. Isolated
thunderstorms are expected this afternoon, but the anticipated
probability/coverage do not warrant a mention at any of the sites.
Calm to light and variable winds increase from the south at 6-10

KMSP...An isolated thunderstorm near the site can`t be ruled out
during the late afternoon and early evening, but the probability
is low.

Sun...VFR. Wind SW 5-10 kts.
Mon...Mainly VFR. Chc TSRA/MVFR. Wind SW 5-10 kts.
Tue...Mainly VFR. Chc TSRA/MVFR. Wind SW 5-10 kts.





NWS MPX Office Area Forecast Discussion

Script by Ken True @Saratoga-Weather.org