National Weather Service - Area Forecast Discussion

FXUS63 KAPX 241042

Area Forecast Discussion
National Weather Service Gaylord MI
642 AM EDT Mon Jun 24 2019

.NEAR TERM...(Today through Tonight)
Issued at 221 AM EDT Mon Jun 24 2019

...Threat for wet weather continues...

High impact weather potential: Minimal. Perhaps a few non-severe
thunderstorms at times.

Pattern synopsis/forecast: Moisture advection underway across the
region as deep southerly flow strengthens between slowly retreating
mid level ridge axis and seasonably intense shortwave trough
rotating across the Central Plains. Precipitable water values
responding accordingly, with latest cross-section analysis showing
inch and a half to slightly greater values spreading north across
our area. Now, despite this impressive moisture surge,
precipitation, at least initially, struggled to reach northern
Michigan as deep layer forcing remained off to our south and west
and with a still lingering sub H8 dry wedge. That has begin to
change a bit early this morning as convectively agitated vort lobe
advances north, initiating some general light showers in the process.

Whole pattern to become a bit more progressive as we head through
today and tonight, owning in large part to organized and robust
upper jet core rotating out of the southern Plains. This will help
drive shortwave trough northeast into and across our area as we head
through later today and tonight...taking on an increasingly negative
tilt as it does so. Attendant surface reflection will deepen
accordingly, with low pressure reaching sub 1000mb levels as it
crosses the northern Lakes tonight. Combination of deep forcing via
passing mid level support/developing cold front and continued
moisture advection should bring increasing shower and thunderstorm
chances over the course of the next 24 hours.

Primary forecast concerns/challenges: Addressing that increasing
shower and thunderstorm potential.

Details: Definitely not expecting an all-day washout as initial wave
dampens, waiting on better forcing to arrive later this afternoon
and evening. Cannot rule out a passing shower at any time this
morning as warm front bows north, but pattern recognition strongly
supports best shower and thunderstorm potential arriving from the
southwest later this afternoon on into this evening as that mid
level wave approaches and developing cold front/occluded front push
into the area. Gotta believe coverage of rain should be pretty
decent during this period, suggested nicely by guidance derived
likely to low end categorical pops. Intensity of any thunderstorms
remains rather uncertain, with some progs suggesting over 1K
joules/kg of most unstable cape and several hundred joules/kg of
mixed layer cape. Deep layer shear ramps up as jet streak spreads
overhead, likely exceeding 30 knots by early this evening. While
shear values look realistic, definitely not sold on some of those
higher end instability signatures, especially with what should be a
mostly cloudy day and less than impressive mid level lapse rates.
Latest SPC day one outlook still has a sliver of our far southwest
in marginal wording for a severe threat. Will continue to monitor,
but thought that with such a minimal coverage area and exceedingly
low confidence is to keep specific severe weather wording out of our
hazardous weather products.

Cold front crosses the area quickly later this evening, ending the
better shower threat for a good portion of northeast lower Michigan,
with deepening deformation expected to continue better rain chances
across eastern upper Michigan and northwest lower Michigan right
into early Tuesday morning.


.SHORT TERM...(Tuesday through Wednesday)
Issued at 221 AM EDT Mon Jun 24 2019

High Impact Weather Potential: Perhaps an isolated thunderstorm
Tuesday afternoon/evening.

Pattern Synopsis/Forecast: Rather impressive mid-level wave and
attendant area of surface low pressure across the northern Great
Lakes region early Tuesday will continue to shift off to the
northeast throughout the day. This will lead to broad cyclonic flow
locally on the backside of the system for much of the day Tuesday
before upper-level flow gradually becomes more zonal through the
remainder of the mid week time frame.

Primary forecast concerns/challenges: Lingering isolated showers and
perhaps a few rumbles of thunder Tuesday.

Overall, a rather tranquil stretch of weather is expected to set up
across the Great Lakes region through the midweek time frame as the
aforementioned impressive late June system continues to trek off to
the northeast. Lingering pockets of deeper moisture and subtle
perturbations aloft pinwheeling around parent troughing over Ontario
may lead to a few additional showers during the day Tuesday through
Tuesday evening. Even a few additional isolated thunderstorms
possible as well given daytime heating leading to a couple hundred
J/kg of MLCAPE...primarily across northern lower MI. Overall,
expecting most areas to stay dry through a large majority of
Tuesday/Tuesday night with showers/storms being the exception more
so than the rule. Otherwise, occasionally gusty westerly winds
(gusts as high as 30 mph) will make the low-mid 70s high temps feel
just a tad cooler than that.

Bubble of high pressure slowly noses into the region from the
southwest Tuesday night through Wednesday, ultimately leading to
what`s expected to be a dry stretch of weather under mostly sunny
skies with temperatures climbing a few degrees over Tuesday as highs
range from the mid 70s - low 80s (near to a degree or two above late
June normals). Westerly winds continue, although shouldn`t be quite
as gusty as Tuesday....highest gusts in the 15-20 mph range.

.LONG TERM...(Wednesday night through Sunday)
Issued at 221 AM EDT Mon Jun 24 2019

High Impact Weather Potential: Occasional thunderstorm chances
return late in the week/next weekend

Primarily quiet weather is expected to continue through late in the
week before the large scale pattern becomes active once again Friday
into the upcoming weekend as several pieces of both northern and
southern stream energy take aim at the Great Lakes/Ohio Valley. Will
continue the trend of returning shower and storm chances back into
the forecast late Thursday night and at various times through the
end of the forecast period of Sunday. This will ultimately paint a
rather bleak picture, but fully believe that no day will be a
washout as plenty of dry times prevails as well. High temps fairly
steady in the upper 70s - low 80s through the end of the week.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 639 AM EDT Mon Jun 24 2019

Varying conditions expected across the taf sites as areas of
showers and a few embedded thunderstorms cross the region. Periods
of MVFR to IFR conditions are expected as low clouds and brief
heavier showers pass overhead. Not expecting any severe weather,
but any stronger storms may produce brief gusty winds. Otherwise,
no significant wind issues expected.


Issued at 221 AM EDT Mon Jun 24 2019

Southeast winds will be on the increase today across
northern Lake Huron on across Whitefish Bay and the Saint Mary`s
River. Still appears conditions will remain below advisory criteria.
Winds veer to west and increase in speed on Tuesday as low pressure
crosses the area tonight, reaching Ontario by Tuesday morning.
Pretty decent summer pressure gradient sets up, likely producing
small craft conditions across most of the nearshore waters. Winds
are expected to subside Tuesday night.

Shower and thunderstorm chances will increase as we head through
today and tonight, although severe storms are not expected. Expect a
few showers to linger into Tuesday.





NWS APX Office Area Forecast Discussion