Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 231135

Area Forecast Discussion
National Weather Service Marquette MI
735 AM EDT MON MAY 23 2016

.SHORT TERM...(Today and tonight)
Issued at 517 AM EDT MON MAY 23 2016

WV imagery and RAP analysis indicated a mid/upper level low over
southern Saskatchewan, a ridge from MO/AR to Lake Superior, and
another low over VA/NC. At the sfc...southerly winds were increasing
through the upper MS valley between a ridge over the eastern Great
Lakes and a cold front through the central Dakotas. More abundant
moisture streaming to the nne from the southern plains ahead of the
cold front along with upper level div ahead of the mid level trough
has supported an area of shra/tsra from western MN into ne Nebraska.
Otherwise mostly clear skies prevailed over the CWA with convective
debris high clouds were spreading into wrn Upper Michigan.

Today, Despite some increase in high clouds, per satellite trends,
expect enough sunshine and mixing to 850 mb temps around 15C will
result in max temps into the mid 80s inland west. Flow off of Lake
Michigan limit highs to the mid 70s over the east. In addition,
mixing will support gusts to 30 mph and drop min RH values to 20 to
25 percent. So, critial fire weather conditions remain on track.
Shra/tsra chances will increase over the far west late.

Tonight, Expect that the area of shra/tsra will steadily progress to
the east but with the blocking ridge to the east, and the stronger
upper level div and qvector conv remaining to the west and north, the
convection will weaken and diminish in coverage as it moves through
Upper Michigan. MUCAPE values in the 400-800 J/Kg range will be
marginal for strong or severe storms. However, if any tsra arrive
over the west while the boundary layer remains unstable, DCAPE values
may be high enough to support some strong wind gusts.

.LONG TERM...(Tuesday through Sunday)
Issued at 337 AM EDT MON MAY 23 2016

Several rounds of convection are expected in the long term, with
POPs almost every period. Put focus into Tue through Wed night as
consensus blend will adequately handle conditions beyond then.

A weakening cold front over western Upper MI Tue morning will
continue to move southeast through the day Tue while a shortwave
moves through and lake breezes form. All these will help fire
convection in an area of increasing CAPE out ahead of the front and
on the warm side of lake breezes. At this time, think that 500-1000
J/kg of CAPE will develop mainly over interior west and central
Upper MI with high temperatures up to 80 degrees. Low level winds
will be weak as will shear, so not expecting organized severe
storms. However, there is potential for some strong storms.

Tue night through most of Wed looks mostly dry, aside from a stray
shower or two, as surface and upper riding passes overhead.

Convection returns late Wed (mainly after 00Z Thu) as a shortwave
moves in from the southwest. Another shortwave move through just
behind the first, possibly keeping convection over the area into Thu
night. Due to timing of initial convection late Wed, CAPE will not
be sufficient for severe weather.

A more significant shortwave may move through the region late in the
week into the weekend, but confidence is fairly low at that point.

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 735 AM EDT MON MAY 23 2016

As the pressure gradient tightens over the Upper Lakes in the wake
of high pressure retreating to the east expect LLWS to impact the
TAF sites at the beginning of the TAf period. With daytime heating
by mid-late morning, the strong southwest winds just above the
surface based inversion will mix out and result in gusty winds.
Since the SSW flow will be tapping dry air through today, VFR
conditions will prevail until this evening. As the SW flow draws
moister air into the Upper Lakes tonight ahead of an approaching
cold front, some shra/perhaps a TS may move into IWD/CMX this
evening and to SAW late tonight. With the greater moisture and
pcpn, MVFR cigs are also expected into CMX/IWD overnight.

.MARINE...(For the 4 AM Lake Superior forecast issuance)
Issued at 517 AM EDT MON MAY 23 2016

Southerly winds of up to 25 knots are expected hrough tonight as a
low pressure trough approaches from the west. The trough will stall
over the Upper Great Lakes Tuesday through Thursday, bringing winds
generally under 20 knots.

Upper Michigan...
  Red Flag Warning until 8 PM EDT /7 PM CDT/ this evening for

Lake Superior...
Lake Michigan...


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