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000
FXUS63 KGRR 270320
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1120 PM EDT THU MAY 26 2016

LATEST UPDATE...
Update

.SYNOPSIS...
Issued at 320 PM EDT Thu May 26 2016

The warm humid airmass will continue through Sunday after which a
cold front will move across Lower Michigan and bring in drier and
cooler air. Highs through the weekend will be in the lower to mid
80s and scattered showers and thunderstorms are also possible.
Memorial Day will be mostly dry with highs around 80.

&&

.UPDATE...
Issued at 1120 PM EDT Thu May 26 2016

Removed precipitation from the forecast tonight as instability has
decreased significantly. Surface based CAPE values have fallen
below 1000 J/KG. There are no triggers the remainder of the night
and the LLJ is positioned well west of the forecast area. Multiple
runs of the HRRR show dry conditions prevailing as well.

Introduced some patchy fog into the forecast as we are expecting
some light fog to develop after the 200am-300am time frame.

It will be a warm night by May standards with lows in the low to
mid 60s in most areas. Normal lows are in the upper 40s to around
50.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 320 PM EDT Thu May 26 2016

Forecast concerns deal with convective trends through the period.
Latest vis loop shows enhanced cu from far southwest Kent county
through central Montcalm county. We`ve seen pulse storms develop and
quickly dissipate along the line. Mesoanalysis shows 1500 j/kg
MLCAPE and LIs near -6c. Aloft we`re moving into a brief period of
NVA which may keep a lid on the storms. Shear is marginal, around 25
knots and unless that increases, any storms that develop should be
sub severe. That said, decent drying in the lowest layers from
latest AMDAR soundings suggest the potential for gusty winds and
small hail. Coverage and intensity of the storms should diminish this
evening as instability decreases.

Another weak short wave will approach around 06z and since we`ll
still be in a soupy airmass we should see convection develop again.
The LLJ increases to 35 knots Friday afternoon and that could keep
convection going through the evening. We have highest pops Friday
afternoon and then diminishing Friday night and Saturday.

Scattered showers and thunderstorms will be possible Saturday and
Saturday night as low pressure moves from the southern Plains into
the upper Mississippi Valley. We`ll remain on the east side of
the system which means high moisture content and decent instability.

Precipitable water values from Friday afternoon through Saturday
night will be near 1.5 inches. Thus any storms that develop will be
capable of locally heavy rain.

.LONG TERM...(Sunday through Thursday)
Issued at 320 PM EDT Thu May 26 2016

The main challenge in the long term deals with the potential for
storms over the later half of the holiday weekend.  The trend is for
less in the way of rainfall on Memorial Day.

Models are showing the mid level trough passing through the forecast
area on Sunday.  This will act to keep the risk for showers and
thunderstorms going then.  This feature loses amplitude as it goes
by. Low level wind fields on Sunday are still elevated and
instability will be present...but mid and upper level winds are
forecasted to decrease.  So if we do end up with storms...the risk
for severe weather looks low at this time.

A weak surface high pressure system is shown to move in for Memorial
Day. This would keep the risk for any shower and thunderstorm
activity low. Given the weakening nature of the mid level wave that
tracks through on Sunday...it is still not certain how much dry air
will move in for Memorial Day. The GFS actually is developing
thunderstorms across WI on the backside of this weak high. The GFS
has been forecasting too much instability lately...thus the more
stable High Res Euro seems better.  Will only feature a very low pop.

More in the way of a dynamic system is shown to move in for the
middle part of the week.  Thus a higher probability of storms will
exist then...with some possibly strong.

Will keep the trend of above normal temperatures going.  The brunt
of any cool airmass is forecast to stay in Canada.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 836 PM EDT Thu May 26 2016

VFR conditions are in place area wide with a few showers
diminishing towards Saginaw Bay. There may be an isolated shower
or storms through 03z, but for the most part expecting dry
conditions tonight.

Main concern tonight is the development of fog. Expecting MVFR
visibilities dropping into the IFR category in most places. We
will likely see some MVFR ceilings as well develop towards the I-94
TAF sites.

VFR conditions should return by 15z at all of the TAF sites.
Thunderstorms will likely develop Friday afternoon becoming more
numerous towards sunset.


&&

.MARINE...
Issued at 320 PM EDT Thu May 26 2016

A weak pressure gradient will result in low winds and wave heights
tonight and friday. High dewpoints however will cause fog to
continue and may become locally dense.


&&

.HYDROLOGY...
Issued at 320 PM EDT Thu May 26 2016

Many areas received rain last night on the order of a quarter inch
all the way up to locally 2 inches across Van Buren County. This has
created some rises on the Black River. Convection through the
weekend will produce mainly localized heavy rainfall so basin
average amounts will be limited...only around a half inch to three
quarters of an inch. Rises will mainly be confined to smaller creeks
and streams though rises on main stem rivers are possible if broader
areas of convection move over larger reaches of the respective
basins.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.
&&

$$

UPDATE...Duke
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MJS
AVIATION...Duke
HYDROLOGY...Hoving
MARINE...04



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000
FXUS63 KAPX 270119
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
919 PM EDT THU MAY 26 2016

.UPDATE...
Issued at 914 PM EDT Thu May 26 2016

Showers and thunderstorms have come to an end with the loss of the
shortwave aloft and daytime heating that sparked them (with the
exception of a couple showers still clinging to far SE Presque
Isle county and far NE Alpena county). Skies have cleared well
across the region with an increase in convective higher level
debris expected to sneak into the GTV bay region later this
evening. Doubt it will hang around long, as the associated storms
will decay into the night. That leaves a decent time of pretty
clear skies to cool the still moist sfc/BL layer. This ought to
result in areas of fog (especially where it rained), as well as
more stratus development. Not sure to what extent each will have,
but believe we will have both strewn about the region. Winds going
light/calm will help their development.

&&

.SHORT TERM...(This evening and overnight)
Issued at 244 PM EDT Thu May 26 2016

Morning low clouds have mixed into a sct/bkn CU deck across our CWA
this afternoon...with some additional cirrus still drifting
overhead. Instability is still in the process of recovering in
response to diurnal heating aided by the development of significant
breaks in the low clouds. Latest NAM12 boosts MUCAPES to near 3000
J/kg later this afternoon...while the RAP13 comes in with a slightly
more modest 2000 J/kg. Both quickly diminish instability with sunset
as would be expected with mainly diurnally-driven convective
situation. Both directional and speed shear strengthen during this
time as well along the warm front...which will certainly aid in the
organization of any convection that does develop. Speed shear is a
bit stronger than direction...so at this point...expect the main
severe wx threat will be strong/damaging winds. In agreement with
latest day 1 SPC outlook...any severe threat should be marginal...
with the potential for isold winds gusts to 60 mph and hail around
an inch in diameter. With respect to POPs...Will certainly keep
chance pops in the forecast thru this evening...especially across
North Central and NE Lwr Michigan where highest instability will
likely develop.

Convection will steadily diminish in both areal coverage and
intensity with sunset and loss of diurnal instability. Cannot
completely rule out the slight chance of a shower or thunderstorm
during the remainder of the night...thus have kept a slight chance
in the overnight forecast. Expect areas of fog will again develop
within the soupy airmass...further reinforced by late
afternoon/evening precip. Should be a relatively mild night...with
overnight lows falling into the mid 50s across Ern Upr Michigan and
to a degree or two either side of 60 across Nrn Lwr Michigan.

.LONG TERM...(Friday through Thursday)
Issued at 244 PM EDT Thu May 26 2016

Friday through Sunday...The holiday weekend is shaping up to be very
summer-like, complete with warm and humid conditions and afternoon
and evening convection.

At upper levels...500mb ridge in place over the Great Lakes to end
the work week, will slowly strengthen through the first half of the
weekend as an upper trough organizes over the central Plains. This
trough will eventually lift into the Great Lakes Sunday. 850mb temps
in this pattern will be around 15c/16c Friday and Saturday, before
cooling to around 10c Sunday as the upper trough pushes east across
the state.

At the surface, a nearly stationary pattern to persist across the
eastern half of the country, with large area of high pressure
anchored over the Atlantic while a storm system organizes over the
Plains. The warm front that lifted north across the state Thursday
will remain well north of the Great Lakes through the weekend,
before the Plains storm system finally pushes across the state
on Sunday.

The overall airmass this weekend will be conducive to the typical
afternoon and evening summer-time showers and thunderstorms. Plenty
of moisture and instability will linger over northern Michigan
Friday through Sunday, with sfc dew pts in the 60s, 850mb dew pts
between 12c and 16c, 0-3km most unstable cape values each afternoon
around 2500 to 3500 j/kg and 850/500mb lapse rates around 7 c/km.
Forcing each day will be enhanced by old thunderstorm outflow
boundaries, along with afternoon lake breeze boundary as northern
Great Lakes water temps remain around 50 degrees and synoptic
southern winds remain below 10 mph. Currently, the best chances for
non-diurnal widespread pcpn this weekend will be Sunday, as
850/700mb qvectors show convergence increasing across the area in
advance of approaching sfc and upper lvl storm systems.

Extended (Sunday night through Thursday)...

A somewhat less active extended period is expected late in the
Memorial Day weekend into next week as energy from northwest Canada
spills into the northern Plains, aiding in rising heights and
associated surface high pressure across the Great Lakes region.
Details become a little more muddy toward the end of the extended
with several possible solutions in regards to a cold front progged
to slide across the Midwest/Great Lakes and resulting precip
potential and temperatures. While temps will generally be trending
cooler throughout the extended, a blended guidance approach suggests
highs back near normal (lower 70s) by the end of the extended, but

Gillen

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 854 PM EDT Thu May 26 2016

This round of showers and storms are just about complete with the
exception of a thin line of scattered showers just west/nw of APN.
These may try and work their way into APN over the next couple of
hours before they dissipate. Otherwise, skies were clearing and
the sfc/low levels remain quite moist. Feeling rather confident in
the development of stratus and maybe a better chance at fog
tonight, developing shortly after midnight and into Friday
morning. Not sure of the extent of the visibility, but cigs have
the ability to go well into IFR. Will likely be issuing updates to
the current TAFS. The stratus/fog will burn off through late
morning with the atmosphere becoming unstable yet again with more
showers and storms anticipated in the later afternoon hours of
Friday.

Winds light/near calm tonight, SE into Friday generally under
10kts turning south at TVC/MBL late in the TAF period.


&&

.MARINE...
Issued at 244 PM EDT Thu May 26 2016

Winds and waves will remain below SCA criteria thru Saturday thanks
to a relatively weak pressure gradient remaining overhead. The
chance of showers and storms will remain in the forecast thru the
weekend...especially during the afternoon and evening as convection
is enhanced by daytime heating/instability.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...Dickson
SHORT TERM...MLR
LONG TERM...SWR/Gillen
AVIATION...Dickson
MARINE...MLR




000
FXUS63 KAPX 270054
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
854 PM EDT THU MAY 26 2016

.SHORT TERM...(This evening and overnight)
Issued at 244 PM EDT Thu May 26 2016

Morning low clouds have mixed into a sct/bkn CU deck across our CWA
this afternoon...with some additional cirrus still drifting
overhead. Instability is still in the process of recovering in
response to diurnal heating aided by the development of significant
breaks in the low clouds. Latest NAM12 boosts MUCAPES to near 3000
J/kg later this afternoon...while the RAP13 comes in with a slightly
more modest 2000 J/kg. Both quickly diminish instability with sunset
as would be expected with mainly diurnally-driven convective
situation. Both directional and speed shear strengthen during this
time as well along the warm front...which will certainly aid in the
organization of any convection that does develop. Speed shear is a
bit stronger than direction...so at this point...expect the main
severe wx threat will be strong/damaging winds. In agreement with
latest day 1 SPC outlook...any severe threat should be marginal...
with the potential for isold winds gusts to 60 mph and hail around
an inch in diameter. With respect to POPs...Will certainly keep
chance pops in the forecast thru this evening...especially across
North Central and NE Lwr Michigan where highest instability will
likely develop.

Convection will steadily diminish in both areal coverage and
intensity with sunset and loss of diurnal instability. Cannot
completely rule out the slight chance of a shower or thunderstorm
during the remainder of the night...thus have kept a slight chance
in the overnight forecast. Expect areas of fog will again develop
within the soupy airmass...further reinforced by late
afternoon/evening precip. Should be a relatively mild night...with
overnight lows falling into the mid 50s across Ern Upr Michigan and
to a degree or two either side of 60 across Nrn Lwr Michigan.

.LONG TERM...(Friday through Thursday)
Issued at 244 PM EDT Thu May 26 2016

Friday through Sunday...The holiday weekend is shaping up to be very
summer-like, complete with warm and humid conditions and afternoon
and evening convection.

At upper levels...500mb ridge in place over the Great Lakes to end
the work week, will slowly strengthen through the first half of the
weekend as an upper trough organizes over the central Plains. This
trough will eventually lift into the Great Lakes Sunday. 850mb temps
in this pattern will be around 15c/16c Friday and Saturday, before
cooling to around 10c Sunday as the upper trough pushes east across
the state.

At the surface, a nearly stationary pattern to persist across the
eastern half of the country, with large area of high pressure
anchored over the Atlantic while a storm system organizes over the
Plains. The warm front that lifted north across the state Thursday
will remain well north of the Great Lakes through the weekend,
before the Plains storm system finally pushes across the state
on Sunday.

The overall airmass this weekend will be conducive to the typical
afternoon and evening summer-time showers and thunderstorms. Plenty
of moisture and instability will linger over northern Michigan
Friday through Sunday, with sfc dew pts in the 60s, 850mb dew pts
between 12c and 16c, 0-3km most unstable cape values each afternoon
around 2500 to 3500 j/kg and 850/500mb lapse rates around 7 c/km.
Forcing each day will be enhanced by old thunderstorm outflow
boundaries, along with afternoon lake breeze boundary as northern
Great Lakes water temps remain around 50 degrees and synoptic
southern winds remain below 10 mph. Currently, the best chances for
non-diurnal widespread pcpn this weekend will be Sunday, as
850/700mb qvectors show convergence increasing across the area in
advance of approaching sfc and upper lvl storm systems.

Extended (Sunday night through Thursday)...

A somewhat less active extended period is expected late in the
Memorial Day weekend into next week as energy from northwest Canada
spills into the northern Plains, aiding in rising heights and
associated surface high pressure across the Great Lakes region.
Details become a little more muddy toward the end of the extended
with several possible solutions in regards to a cold front progged
to slide across the Midwest/Great Lakes and resulting precip
potential and temperatures. While temps will generally be trending
cooler throughout the extended, a blended guidance approach suggests
highs back near normal (lower 70s) by the end of the extended, but

Gillen

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 854 PM EDT Thu May 26 2016

This round of showers and storms are just about complete with the
exception of a thin line of scattered showers just west/nw of APN.
These may try and work their way into APN over the next couple of
hours before they dissipate. Otherwise, skies were clearing and
the sfc/low levels remain quite moist. Feeling rather confident in
the development of stratus and maybe a better chance at fog
tonight, developing shortly after midnight and into Friday
morning. Not sure of the extent of the visibility, but cigs have
the ability to go well into IFR. Will likely be issuing updates to
the current TAFS. The stratus/fog will burn off through late
morning with the atmosphere becoming unstable yet again with more
showers and storms anticipated in the later afternoon hours of
Friday.

Winds light/near calm tonight, SE into Friday generally under
10kts turning south at TVC/MBL late in the TAF period.

&&

.MARINE...
Issued at 244 PM EDT Thu May 26 2016

Winds and waves will remain below SCA criteria thru Saturday thanks
to a relatively weak pressure gradient remaining overhead. The
chance of showers and storms will remain in the forecast thru the
weekend...especially during the afternoon and evening as convection
is enhanced by daytime heating/instability.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...MLR
LONG TERM...SWR/Gillen
AVIATION...Dickson
MARINE...MLR



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000
FXUS63 KMQT 262326
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
726 PM EDT THU MAY 26 2016

.SHORT TERM...(This evening through Friday)
Issued at 347 PM EDT THU MAY 26 2016

Complicated convective forecast as coverage and intensity depends on
smaller scale shortwaves within broad sw flow aloft. Those type of
features are tough to pin down even 12 hours out.

Currently, shortwave moving across became enhanced by convection
late last night and that shortwave with sharp drying has forced the
showers and thunderstorms this aftn. Wave will continue to north of
Upr Michigan this evening so overall should see downward trend to
shra/tsra over the area currently. Thus far the main hazards from
these storms have been lightning and heavy rain. Have had multiple
reports of heavy rain especially over western Upr Michigan. Since
heating has not been as much as expected, instability has been
meager with sfc/ML/MU CAPES staying blo 500j/kg. Effective shear
also around 30 kts which is on the low-end with the weak
instability. LCLs are low enough around 1000m for brief spin up
tornado due to the higher dwpnts around, but this is being offset by
limited low-level shear which is well under 20 kts. Away from these
initial showers/storms could see isold shra/tsra try to reform over
northwest WI where sfc based CAPES this aftn are rising back up to
1000j/kg in wake of the shra/tsra that moved through earlier. A lot
of subsidence behind this initial shortwave per WV loop, so not sure
on the coverage in this redevelopment area. A bit of an enhanced cu
field trying to form currently. Supercell composite (looks at
effective shear and instability) does indicate there could be
supercells, but mean storm motion and right moving motion point to
majority of this activity staying along WI border or farther into WI,
if it occurs at all.

By late evening overall setup should be more quiet. Lots of low-
level moisture with generally lack of cloud cover and light winds
points to widespread fog which may be dense. Any fog will linger
into Fri morning, especially where light winds are onshore off the
Great Lakes.

Looking upstream there is a minimum in convective activity until
southern Neb and northwest MO where more concentrated shortwaves are
along with upper level jet and stronger sfc low. Some remnants of
this with possible additonal waves due to showers and storms forming
farther north across Neb/IA/Ill should will allow chances for
showers and storms to increase by Fri aftn. We`ll see if clearing
is more widespread than today. If so, readings will be able to reach
mid-upr 70s while dwpnts are around 60 degrees. Result will be sfc
based CAPES more in the 1000-1500j/kg range which will be plenty
high enough for organized severe storms since deep layer shear is
forecast to be 35-45 kts. As was case today, everything will depend
on how much insolation we receive before the shortwave(s) arrive by
aftn.

.LONG TERM...(Friday night through Thursday)
Issued at 314 PM EDT THU MAY 26 2016

Upper air pattern forecasted to be a trough in the Pacific NW and
another trough in the central plains 00z Sat. There is also a broad
500 mb ridge over the ern U.S. 00z Sat that builds into the upper
Great Lakes region Fri night. This trough moves east into the Upper
Great Lakes Sat night into Sun.

Continues to look unsettled this forecast period through Sun and
hard to pin down any details with the numerous shortwaves moving
through. Will not be a total washout as there could be some brief
dry periods mixed in there from Fri night into Sun, but timing these
is next to impossible with convection that has not even developed
yet. Easiest course is to go with persistence and broadbrush this
forecast. Overall, did not make too many changes to the going
forecast for temperatures or weather.

In the extended, GFS and ECMWF show two broad 500 MB troughs across
the western and eastern U.S. 12z Mon. The trough over the western
U.S. moves into the Rockies 12z Tue and into the northern plains 12z
Wed which remains into 12z Thu. Still looks unsettled and
temperatures look to be near normal to slightly above normal for
this forecast period.
&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 719 PM EDT THU MAY 26 2016

Main area of rain showers has lifted east so expect dry conditions
the rest of the night across the TAF sites. With enough clearing
could see low clouds and fog at all the TAF sites overnight tonight
into Friday morning. Conditions could drop to VLIFR, especially at
CMX where light onshore winds are expected and areas of fog still
linger over Lk Superior. Another round of showers and thunderstorms
are expected Friday afternoon. &&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 347 PM EDT THU MAY 26 2016

Expect winds at or below 20 knots through the forecast period. Fog
will continue to be a problem. Have dense fog advisory through Fri.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Dense Fog Advisory until 6 PM EDT /5 PM CDT/ Friday for LSZ162-
     243>246-263>267.

Lake Michigan...
None.
&&

$$

SHORT TERM...JLA
LONG TERM...07
AVIATION...Voss
MARINE...JLA




000
FXUS63 KMQT 261952
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
352 PM EDT THU MAY 26 2016

.SHORT TERM...(This evening through Friday)
Issued at 347 PM EDT THU MAY 26 2016

Complicated convective forecast as coverage and intensity depends on
smaller scale shortwaves within broad sw flow aloft. Those type of
features are tough to pin down even 12 hours out.

Currently, shortwave moving across became enhanced by convection
late last night and that shortwave with sharp drying has forced the
showers and thunderstorms this aftn. Wave will continue to north of
Upr Michigan this evening so overall should see downward trend to
shra/tsra over the area currently. Thus far the main hazards from
these storms have been lightning and heavy rain. Have had multiple
reports of heavy rain especially over western Upr Michigan. Since
heating has not been as much as expected, instability has been
meager with sfc/ML/MU CAPES staying blo 500j/kg. Effective shear
also around 30 kts which is on the low-end with the weak
instability. LCLs are low enough around 1000m for brief spin up
tornado due to the higher dwpnts around, but this is being offset by
limited low-level shear which is well under 20 kts. Away from these
initial showers/storms could see isold shra/tsra try to reform over
northwest WI where sfc based CAPES this aftn are rising back up to
1000j/kg in wake of the shra/tsra that moved through earlier. A lot
of subsidence behind this initial shortwave per WV loop, so not sure
on the coverage in this redevelopment area. A bit of an enhanced cu
field trying to form currently. Supercell composite (looks at
effective shear and instability) does indicate there could be
supercells, but mean storm motion and right moving motion point to
majority of this activity staying along WI border or farther into WI,
if it occurs at all.

By late evening overall setup should be more quiet. Lots of low-
level moisture with generally lack of cloud cover and light winds
points to widespread fog which may be dense. Any fog will linger
into Fri morning, especially where light winds are onshore off the
Great Lakes.

Looking upstream there is a minimum in convective activity until
southern Neb and northwest MO where more concentrated shortwaves are
along with upper level jet and stronger sfc low. Some remnants of
this with possible additonal waves due to showers and storms forming
farther north across Neb/IA/Ill should will allow chances for
showers and storms to increase by Fri aftn. We`ll see if clearing
is more widespread than today. If so, readings will be able to reach
mid-upr 70s while dwpnts are around 60 degrees. Result will be sfc
based CAPES more in the 1000-1500j/kg range which will be plenty
high enough for organized severe storms since deep layer shear is
forecast to be 35-45 kts. As was case today, everything will depend
on how much insolation we receive before the shortwave(s) arrive by
aftn.

.LONG TERM...(Friday night through Thursday)
Issued at 314 PM EDT THU MAY 26 2016

Upper air pattern forecasted to be a trough in the Pacific NW and
another trough in the central plains 00z Sat. There is also a broad
500 mb ridge over the ern U.S. 00z Sat that builds into the upper
Great Lakes region Fri night. This trough moves east into the Upper
Great Lakes Sat night into Sun.

Continues to look unsettled this forecast period through Sun and
hard to pin down any details with the numerous shortwaves moving
through. Will not be a total washout as there could be some brief
dry periods mixed in there from Fri night into Sun, but timing these
is next to impossible with convection that has not even developed
yet. Easiest course is to go with persistence and broadbrush this
forecast. Overall, did not make too many changes to the going
forecast for temperatures or weather.

In the extended, GFS and ECMWF show two broad 500 MB troughs across
the western and eastern U.S. 12z Mon. The trough over the western
U.S. moves into the Rockies 12z Tue and into the northern plains 12z
Wed which remains into 12z Thu. Still looks unsettled and
temperatures look to be near normal to slightly above normal for
this forecast period.
&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 218 PM EDT THU MAY 26 2016

Rain showers and isolated thunderstorms will affect the TAF sites
this afternoon. Best chance of prevailing thunder will be at KSAW.
Distubance causing rain lifts out of area this evening. With enough
clearing could see low clouds and fog at all the TAF sites overnight
tonight into Friday morning. Conditions could drop to VLIFR,
especially at CMX as winds due to closer proximity of the widespread
fog on Lk Superior. More showers and thunderstorms should roll back
in late Friday morning or into Friday afternoon.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 347 PM EDT THU MAY 26 2016

Expect winds at or below 20 knots through the forecast period. Fog
will continue to be a problem. Have dense fog advisory through Fri.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Dense Fog Advisory until 6 PM EDT /5 PM CDT/ Friday for LSZ162-
     243>246-263>267.

Lake Michigan...
  Dense Fog Advisory until 10 AM EDT Friday for LMZ248-250.

&&

$$

SHORT TERM...JLA
LONG TERM...07
AVIATION...JLA
MARINE...JLA




000
FXUS63 KAPX 261844
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
244 PM EDT THU MAY 26 2016

.SHORT TERM...(This evening and overnight)
Issued at 244 PM EDT Thu May 26 2016

Morning low clouds have mixed into a sct/bkn CU deck across our CWA
this afternoon...with some additional cirrus still drifting
overhead. Instability is still in the process of recovering in
response to diurnal heating aided by the development of significant
breaks in the low clouds. Latest NAM12 boosts MUCAPES to near 3000
J/kg later this afternoon...while the RAP13 comes in with a slightly
more modest 2000 J/kg. Both quickly diminish instability with sunset
as would be expected with mainly diurnally-driven convective
situation. Both directional and speed shear strengthen during this
time as well along the warm front...which will certainly aid in the
organization of any convection that does develop. Speed shear is a
bit stronger than direction...so at this point...expect the main
severe wx threat will be strong/damaging winds. In agreement with
latest day 1 SPC outlook...any severe threat should be marginal...
with the potential for isold winds gusts to 60 mph and hail around
an inch in diameter. With respect to POPs...Will certainly keep
chance pops in the forecast thru this evening...especially across
North Central and NE Lwr Michigan where highest instability will
likely develop.

Convection will steadily diminish in both areal coverage and
intensity with sunset and loss of diurnal instability. Cannot
completely rule out the slight chance of a shower or thunderstorm
during the remainder of the night...thus have kept a slight chance
in the overnight forecast. Expect areas of fog will again develop
within the soupy airmass...further reinforced by late
afternoon/evening precip. Should be a relatively mild night...with
overnight lows falling into the mid 50s across Ern Upr Michigan and
to a degree or two either side of 60 across Nrn Lwr Michigan.

.LONG TERM...(Friday through Thursday)
Issued at 244 PM EDT Thu May 26 2016

Friday through Sunday...The holiday weekend is shaping up to be very
summer-like, complete with warm and humid conditions and afternoon
and evening convection.

At upper levels...500mb ridge in place over the Great Lakes to end
the work week, will slowly strengthen through the first half of the
weekend as an upper trough organizes over the central Plains. This
trough will eventually lift into the Great Lakes Sunday. 850mb temps
in this pattern will be around 15c/16c Friday and Saturday, before
cooling to around 10c Sunday as the upper trough pushes east across
the state.

At the surface, a nearly stationary pattern to persist across the
eastern half of the country, with large area of high pressure
anchored over the Atlantic while a storm system organizes over the
Plains. The warm front that lifted north across the state Thursday
will remain well north of the Great Lakes through the weekend,
before the Plains storm system finally pushes across the state
on Sunday.

The overall airmass this weekend will be conducive to the typical
afternoon and evening summer-time showers and thunderstorms. Plenty
of moisture and instability will linger over northern Michigan
Friday through Sunday, with sfc dew pts in the 60s, 850mb dew pts
between 12c and 16c, 0-3km most unstable cape values each afternoon
around 2500 to 3500 j/kg and 850/500mb lapse rates around 7 c/km.
Forcing each day will be enhanced by old thunderstorm outflow
boundaries, along with afternoon lake breeze boundary as northern
Great Lakes water temps remain around 50 degrees and synoptic
southern winds remain below 10 mph. Currently, the best chances for
non-diurnal widespread pcpn this weekend will be Sunday, as
850/700mb qvectors show convergence increasing across the area in
advance of approaching sfc and upper lvl storm systems.

Extended (Sunday night through Thursday)...

A somewhat less active extended period is expected late in the
Memorial Day weekend into next week as energy from northwest Canada
spills into the northern Plains, aiding in rising heights and
associated surface high pressure across the Great Lakes region.
Details become a little more muddy toward the end of the extended
with several possible solutions in regards to a cold front progged
to slide across the Midwest/Great Lakes and resulting precip
potential and temperatures. While temps will generally be trending
cooler throughout the extended, a blended guidance approach suggests
highs back near normal (lower 70s) by the end of the extended, but

Gillen

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 117 PM EDT Thu May 26 2016

Scattered showers and thunderstorms will redevelop across Nrn Lwr
Michigan later this afternoon and this evening as CAPES increase
to near 2500 J/kg thanks to diurnal heating. Modest wind shear
thru the column could produce an isold strong/marginally svr
storm. The best chance of precip will be across North Central and
NE Lwr Michigan...including APN. Will handle with VCTS for a
portion of the afternoon and early evening. Will leave the rest of
our TAFs (PLN/TVC/MBL) dry for now and update if needed.
Southerly winds around 10 kts this afternoon will become
light/variable tonight and then shift to the SE on Friday.

&&

.MARINE...
Issued at 244 PM EDT Thu May 26 2016

Winds and waves will remain below SCA criteria thru Saturday thanks
to a relatively weak pressure gradient remaining overhead. The
chance of showers and storms will remain in the forecast thru the
weekend...especially during the afternoon and evening as convection
is enhanced by daytime heating/instability.

&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...MLR
LONG TERM...SWR/Gillen
AVIATION...MLR
MARINE...MLR




000
FXUS63 KAPX 261717
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
117 PM EDT THU MAY 26 2016

.UPDATE...
Issued at 1125 AM EDT Thu May 26 2016

Low clouds continue to fill in across all of Nrn Michigan late
this morning north of the approaching warm front. Wave of
overnight convection has pushed well east of our CWA...right in
time for our next wave of convection lifting NE out of Wisconsin
toward Nrn Michigan just ahead of the warm front. This area of
precip has shown an overall diminish in both areal coverage and
intensity over the last few hours...but expect both should ramp
back up again as we head into the afternoon thanks to diurnal
heating and increasing daytime instability. Big question is just
how much instability will we be able to realize given increasing
low level cloudiness which will limit diurnal instability. If we
are able to develop some good breaks in these clouds...CAPES
should reach to around 2000 joules this afternoon...certainly
enough for descent convective development. Will certainly keep
increasing chance pops in the forecast for the afternoon...
especially across North Central and NE Lwr Michigan where lake
breeze development off of Lake Huron lends to better low level
convergence with SW low level synoptic flow. Potential for
marginal svr storms will likely depend to a certain extent if we
break out of the low clouds and achieve better diurnal
instability. At this point...we certainly cannot rule out a few
stronger storms with some shear thru the column.

UPDATE Issued at 738 AM EDT Thu May 26 2016

Some aspects of the forecast today are worth re-evaluating.
Nighttime precip is departing largely on schedule, maybe a bit
ahead of schedule. However, we have an upstream MCS now pushing
into western WI, which has held together better than expected
several hours ago. There are a multitude of model solutions, from
the Nam (which doesn/t know the MCS exists), to the SPC HRRR
(which lets it slowly die across central/northern WI), to the RAP
(which slowly but steadily brings it all the way into northern MI
this afternoon).

The most likely scenario is that the MCV associated with upstream
convection will manage to carry some dying SHRA into parts of nw
lower MI as we approach or go past midday.

Earlier forecast did not have any precip near Lake MI. Will add
some pops to parts of nw lower MI beginning midday, and will add
some cloud cover there as well. Max temps could use a slight
downward tweak in response. Does this reduce the chance of any svr
TSRA this afternoon? It might, but the obvious incoming MCV will
provide a shot of dynamics that was not earlier anticipated. For
now will leave the HWO unaltered.

&&

.SHORT TERM...(Today and tonight)
Issued at 346 AM EDT Thu May 26 2016

High impact weather potential: a few severe t-storms possible
this afternoon/evening in northern lower.

A warm front continues to slowly work northward into lower MI,
presently north of TVC and near HTL. This front should make the
Straits area today, maybe even clear it for a time, before low
pressure departing across northern Quebec helps drag it back
southward tonight. A nw-se oriented band of shra is moving into
eastern upper and n central lower mi, supported by broad
warm/moist advection but with overall waning instability.
Isolated shra/tsra activity is seen ahead of this band. Forecast
remains on the messy side, with precip trends the main concern.

Today...shra/tsra will continue to lift ne-ward across northern MI
this morning. Much of this activity will have wound down/exited by
12z/8am, with eastern upper/ne lower MI likely to see at least some
activity lingering a bit past that. Tricky cloud forecast behind
this. Central and northern WI has plenty of stratus/fog, but we
have almost no low clouds to speak of. Though ongoing precip
event may help generate some, we may not have enough time to
develop much before sun starts eating away at them. That said,
will be difficult for eastern upper MI to not have lower clouds
this morning (and perhaps longer), given the warm/moist pattern
and prevalence of marine influences. In northern lower, expect a
period of clearing behind precip band, rather quickly giving way
to cumulus development as temps rise into the 70s with dew points
in the lower 60s.

Sw 950mb winds are 10-15kt, low enough to allow for some lake breeze
development, but not like the bonanza we saw yesterday. That will be
one possible trigger mechanism to take advantage of a reasonably
healthy amount of instability. The Nam is much too aggressive;
more reasonable progs from the Sref-Mean and GFS advertise MLCape
in the 1-1.5k j/kg range. That is more than yesterday. We also
have more shear than yesterday, with 0-6km bulk shear of 30-35kt.
This is not overwhelmingly favorable, but not terrible. We
managed one severe storm yesterday (right on top of HTL), and
suspect we have the ingredients to get a few today. Not a major
outbreak by any stretch, but enough for a moderately busy
afternoon/evening. CIPS analogs suggest a 30-40 percent chance of
at least one svr here.

Sct afternoon/evening pops will be placed away from the Lake MI
shadow in northern lower. Will keep most other areas dry, though
far western Mackinac Co could see some spillover from decaying
convection in western upper MI late in the day.

Max temps from near 70f/lower 70s in eastern upper MI, to lower 80s
in much of northern lower.

Tonight...diurnal convection from the afternoon will fade out by
late evening. With little in the war of forcing, and the primary low
level jet pointing at southern Lake Mi, don/t anticipate something
new firing here overnight. Could we have enough low-level sw flow to
generate new convection over the Lake Mi cold dome, and/or support
MCS remnants as they try to move in from the west? Either scenario
is plausible; neither is one that the NCAR or NSSL hi-res ensembles
are terribly excited about. Think regardless that precip coverage
will not be impressive, if it even happens at all. Am so not a fan
of 20 pops (i.e. slight chance), but that/s what we and our
neighbors are already carrying, and will let that ride thru most of
the night in most areas. Will also allow for some fog overnight.
Min temps mid 50s to around 60f.

.LONG TERM...(Friday through Wednesday)
Issued at 346 AM EDT Thu May 26 2016

(5/27)Friday...Ridging at 500 mb begins to move a little more north
and east of the forecast area, putting us in the weak part of the
jet streak off to the west. Meanwhile, the sfc low looks to try and
move to the east into the Upper Great Lakes, at least on the ECMWF,
while the GFS is more to the west, in the Dakotas. Lower Michigan
looks to be in the warm sector, and with the weak 500 mb jet, and
difluence, the thunder chances increase through the morning and into
the afternoon. As noted earlier, with so much of the dynamics to the
west, like on the GFS, and once we lose the heat of the day, think
that our chances are just that, chances, instead of likely it was
during the day and evening hours. ECMWF is a little more bullish
with the sfc low and would continue with the rain showers, and
thunderstorms in NW Lower, and portions of E Upper.

(5/28)Saturday...Again we run into the same issue as we had for
Friday`s forecast, only this time, the models are a little closer,
with the sfc low to the west, as well as the 500 mb trough. So as
the trough moves closer, and the sunshine begins to destabilize
things, the chances for thunderstorms will go up through the day. Of
course, this looks to diminish once we lose the heat of the day and
the 500 mb shortwave trough rotates through the region, and the 700-
500mb layer dry slot begins to help cap off the convection during
the evening and overnight.

Extended (Sunday through Wednesday)...Low confidence pattern this
week with the ECMWF and the GFS at odds with the forecast after
Monday. The 500 mb shortwave trough moves through the Upper Great
Lakes so that Sunday has showers and thunderstorms, and it ends up
dry over N Lower Sunday night.  Models continue to look dry into
Monday night, although GFS has some qpf splattered about during the
day. Tuesday, both models start with 500 mb ridging in the Upper
Great Lakes, so that the day probably ends up dry. However, going
into the evening, the ECWMF pushes a 500 mb trough into the region,
while the GFS amplifies the ridge a bit and keeps the low (now a cut
off) back farther west. This remains the case through Wednesday as
the ECMWF says rain and the GFS is dry.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 117 PM EDT Thu May 26 2016

Scattered showers and thunderstorms will redevelop across Nrn Lwr
Michigan later this afternoon and this evening as CAPES increase
to near 2500 J/kg thanks to diurnal heating. Modest wind shear
thru the column could produce an isold strong/marginally svr
storm. The best chance of precip will be across North Central and
NE Lwr Michigan...including APN. Will handle with VCTS for a
portion of the afternoon and early evening. Will leave the rest of
our TAFs (PLN/TVC/MBL) dry for now and update if needed.
Southerly winds around 10 kts this afternoon will become
light/variable tonight and then shift to the SE on Friday.

&&

.MARINE...
Issued at 346 AM EDT Thu May 26 2016

Humid pattern with generally light southerly flow will persist.
This will maintain fog at times over the chilly waters of the
Great Lakes. Small craft advisories will not be needed in the near
future. Sporadic chances for showers and t-storms continue,
especially very early this morning.

&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...MLR
SHORT TERM...JZ
LONG TERM...JSL
AVIATION...MLR
MARINE...JZ




000
FXUS63 KGRR 261634
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1234 PM EDT THU MAY 26 2016

LATEST UPDATE...
Mesoscale Discussion

.MESOSCALE DISCUSSION...
Issued at 1234 PM EDT Thu May 26 2016

A warm, moisture-laden airmass is currently in place across Lower
Michigan. 16z MLCAPE was analyzed at greater than 1000 J/kg across
most of the forecast area. 12 pm surface dewpoints were in the mid
to upper 60s. Around 1500+ J/kg MLCAPE is forecast into early
evening. Moisture and instability are certainly sufficient for
storms this afternoon.

An area of 30 knots of deep layer shear has nosed into the
northwest forecast area. 0-6 km bulk shear change of +15 kts in
the past 3 hours was noted in portions of Wisconsin and Illinois.
A weakening shortwave is expected to provide modest mid-level
forcing into early evening. Any stronger convection will likely
have to rely on lake breeze convergence. Given the unstable
environment and marginal deep layer shear, scattered storms are
expected mainly in the 2-7 pm timeframe. A few could be stronger
with gusts over 30 mph and pea size hail.

&&

.SYNOPSIS...
Issued at 330 AM EDT Thu May 26 2016

Warm and humid weather with periodic showers and thunderstorms will
continue through at least Sunday. A cold front late in the holiday
weekend may bring dry and less humid weather for Memorial Day.

&&

.UPDATE...
Issued at 754 AM EDT Thu May 26 2016

Based on upstream trends and latest HRRR runs have updated to
increase pops this afternoon, mainly near/east of a line from GRR
to AZO. Will also now need to monitor the risk for some stronger
storms as latest RUC update is more ambitious with deep layer
shear /35 kt 0-6 KM layer/ and low level jet /25-30 kt at H8/.
Capes in excess of 2000 J/KG could make for a few hours of active
weather for parts of the area between roughly 2PM and 6 PM. This
is all related to the shortwave/MCV feature drifting in from the
west later today, working in concert with the lake breeze front
near pk heating.

&&

.SHORT TERM...(Today through Saturday)
Issued at 330 AM EDT Thu May 26 2016

Shortwave responsible for overnight rain will exit early this
morning leaving a window of predominately dry weather this morning.
However low chc pops are warranted for this afternoon as instability
builds and fuels scattered diurnal convection.

Sfc Dew pts near 65 will lead to SB Capes near 2500 J/KG inland from
Lk MI. Current water vapor imagery shows another shortwave/several
vorticity maxima upstream across MN/IA/MO. The arrival of this
shortwave should be a trigger for afternoon convection, in
additional to wk sfc convergence along the lk breeze front.
Coverage is expected to be scattered.

The next feature of interest is a shortwave which rounds the base of
the trough in the srn plains later friday, and heads slowly
northeast, reaching Wisconsin by 12Z Sunday. Models indicate a 30-40
kt low level jet developing ahead of this wave, which becomes aimed
at Sw Lwr MI for a prolonged period from Friday afternoon through
Saturday night. PWATs of 1.5 to 1.75 are progged during this time,
with deep unidirectional flow and continued MU Capes over 1000
J/KG - possibly leading to a heavy rain threat. The severe
weather threat remains quite low however since deep layer shear
values generally remain under 30 kts.

.LONG TERM...(Saturday night through Wednesday)
Issued at 330 AM EDT Thu May 26 2016

As we work through the holiday weekend the dominate ridge that has
been parked over the eastern seaboard should gradually weaken.  This
will allow an upper trough and cold front to push across the Great
Lakes late Sunday or Sunday night.  This will not only bring more
risks of showers and storms, but it will also bring less humid air
into the region to end the holiday weekend.  Memorial Day and into
the mid portion of next week should be very pleasant, not as warm
and less humid.

The models rebuild the ridge in the east toward mid week, but
surface high pressure does not slide by until about Tuesday
afternoon, so the warmer southerly breezes won`t move in until
Wednesday at the earliest.

I tweaked the Sunday night min down a bit as we should be in the
cooler air mass by then.  Minimal rain chances finally move in by
Sunday night and linger until Tuesday night or Wednesday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 750 AM EDT Thu May 26 2016

VFR weather this morning followed by scattered thunderstorms this
afternoon. Main threat of storms is roughly 18Z-23Z, east of HWY
131. Any storm potential at MKG should end earlier, by 20-21z, as
the stable lake breeze spreads inland.

Any lingering storms toward LAN/JXN ending early this evening
then some fog or stratus probably forming at night. We could see
IFR conditions developing after 06z tonight, especially after
09z.


&&

.MARINE...
Issued at 330 AM EDT Thu May 26 2016

Dew points over 60 have arrive which support a fog threat over lk
mi. However the flow is 10 to 20 kts out of the south which may help
keep things mixed just enough to limit the fog threat. Will maintain
areas of fog in the nearshore fcst for the next 48 hours, but
confidence too low for any fog advisories due to the wind speeds.


&&

.HYDROLOGY...
Issued at 314 PM EDT Wed May 25 2016

The rivers are certainly in a position to handle a half inch to an
inch of rain through the weekend with little impact other than
mainly within bank rises. Locally heavier rainfall could potentially
cause quicker rises on smaller creeks and streams, but the basin
average QPF should not be high enough to warrant flooding on main
stem rivers or even tributaries. Nevertheless, local trends will be
monitored as storms occasionally develop across the region for the
next several days.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.
&&

$$

MESOSCALE...EBW
UPDATE...Meade
SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...JK
AVIATION...Meade
HYDROLOGY...Hoving
MARINE...Meade




000
FXUS63 KGRR 261154
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
754 AM EDT THU MAY 26 2016

LATEST UPDATE...
Update/Aviation

.SYNOPSIS...
Issued at 330 AM EDT Thu May 26 2016

Warm and humid weather with periodic showers and thunderstorms will
continue through at least Sunday. A cold front late in the holiday
weekend may bring dry and less humid weather for Memorial Day.

&&

.UPDATE...
Issued at 754 AM EDT Thu May 26 2016

Based on upstream trends and latest HRRR runs have updated to
increase pops this afternoon, mainly near/east of a line from GRR
to AZO. Will also now need to monitor the risk for some stronger
storms as latest RUC update is more ambitious with deep layer
shear /35 kt 0-6 KM layer/ and low level jet /25-30 kt at H8/.
Capes in excess of 2000 J/KG could make for a few hours of active
weather for parts of the area between roughly 2PM and 6 PM. This
is all related to the shortwave/MCV feature drifting in from the
west later today, working in concert with the lake breeze front
near pk heating.

&&

.SHORT TERM...(Today through Saturday)
Issued at 330 AM EDT Thu May 26 2016

Shortwave responsible for overnight rain will exit early this
morning leaving a window of predominately dry weather this morning.
However low chc pops are warranted for this afternoon as instability
builds and fuels scattered diurnal convection.

Sfc Dew pts near 65 will lead to SB Capes near 2500 J/KG inland from
Lk MI. Current water vapor imagery shows another shortwave/several
vorticity maxima upstream across MN/IA/MO. The arrival of this
shortwave should be a trigger for afternoon convection, in
additional to wk sfc convergence along the lk breeze front.
Coverage is expected to be scattered.

The next feature of interest is a shortwave which rounds the base of
the trough in the srn plains later friday, and heads slowly
northeast, reaching Wisconsin by 12Z Sunday. Models indicate a 30-40
kt low level jet developing ahead of this wave, which becomes aimed
at Sw Lwr MI for a prolonged period from Friday afternoon through
Saturday night. PWATs of 1.5 to 1.75 are progged during this time,
with deep unidirectional flow and continued MU Capes over 1000
J/KG - possibly leading to a heavy rain threat. The severe
weather threat remains quite low however since deep layer shear
values generally remain under 30 kts.

.LONG TERM...(Saturday night through Wednesday)
Issued at 330 AM EDT Thu May 26 2016

As we work through the holiday weekend the dominate ridge that has
been parked over the eastern seaboard should gradually weaken.  This
will allow an upper trough and cold front to push across the Great
Lakes late Sunday or Sunday night.  This will not only bring more
risks of showers and storms, but it will also bring less humid air
into the region to end the holiday weekend.  Memorial Day and into
the mid portion of next week should be very pleasant, not as warm
and less humid.

The models rebuild the ridge in the east toward mid week, but
surface high pressure does not slide by until about Tuesday
afternoon, so the warmer southerly breezes won`t move in until
Wednesday at the earliest.

I tweaked the Sunday night min down a bit as we should be in the
cooler air mass by then.  Minimal rain chances finally move in by
Sunday night and linger until Tuesday night or Wednesday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 750 AM EDT Thu May 26 2016

VFR weather this morning followed by scattered thunderstorms this
afternoon. Main threat of storms is roughly 18Z-23Z, east of HWY
131. Any storm potential at MKG should end earlier, by 20-21z, as
the stable lake breeze spreads inland.

Any lingering storms toward LAN/JXN ending early this evening
then some fog or stratus probably forming at night. We could see
IFR conditions developing after 06z tonight, especially after
09z.

&&

.MARINE...
Issued at 330 AM EDT Thu May 26 2016

Dew points over 60 have arrive which support a fog threat over lk
mi. However the flow is 10 to 20 kts out of the south which may help
keep things mixed just enough to limit the fog threat. Will maintain
areas of fog in the nearshore fcst for the next 48 hours, but
confidence too low for any fog advisories due to the wind speeds.


&&

.HYDROLOGY...
Issued at 314 PM EDT Wed May 25 2016

The rivers are certainly in a position to handle a half inch to an
inch of rain through the weekend with little impact other than
mainly within bank rises. Locally heavier rainfall could potentially
cause quicker rises on smaller creeks and streams, but the basin
average QPF should not be high enough to warrant flooding on main
stem rivers or even tributaries. Nevertheless, local trends will be
monitored as storms occasionally develop across the region for the
next several days.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.
&&

$$

UPDATE...Meade
SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...JK
AVIATION...Meade
HYDROLOGY...Hoving
MARINE...Meade



  [top]

000
FXUS63 KDTX 261107
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
707 AM EDT THU MAY 26 2016

.AVIATION...

Mid level subsidence trailing the early morning shower/storm complex
will maintain a quiet period for the remainder of the morning into
early afternoon. That will leave the question of lower cloud
coverage across the terminal corridor with MVFR observed out of
Indiana and portions of western lower Michigan. Expect there will be
intervals of restriction before boundary layer mixing carries bases
into VFR by late morning.

The larger convective complex in progress at press time over
Wisconsin/Illinois is worthy of monitoring for impacts in SE
Michigan later in the day. This activity could be sustained by
renewed surface based instability downstream and/or produce a
remnant MCV that could organize new development over our area mid to
late afternoon. There is enough confidence for a prob30 mention to
cover this scenario.

FOR DTW... A quiet morning period complicated only by potential for
MVFR ceiling from Indiana/western lower Michigan mixing to VFR below
5000 ft through early afternoon. Afternoon thunderstorm potential
could be enhanced by ongoing morning activity from Wisconsin to
Illinois and/or its remnants.

//DTW Threshold Probabilities...

* Moderate for ceiling 5000 FT or less today.

* Moderate for thunderstorms affecting DTW/D21 airspace mid to late
  afternoon.

&&

.PREV DISCUSSION...
Issued at 339 AM EDT Thu May 26 2016

DISCUSSION...

Currently on radar we have a line of showers, with isolated
thunderstorms, working slowly northeast through western and central
Michigan. These showers went up on shortwave trough lifting through
the longwave flow with a lobe of vorticity associated with it.
Though the showers are moving into a less favorable environment, it
appears there is a weak MCV embedded which is likely providing it
the forcing it needs to progress further across the state through
the early morning hours. Updated pops across the Saginaw Valley to
categorical with the increased confidence that it will at least hold
together into the area. With such slow forward motion, it could
still fall apart before reaching the bay.  Regardless, any precip
that falls will likely be light and not amount to much as upstream
observations suggest.

In the wake of the early morning showers it looks like we should
dry out once again, at least for several hours. Fairly strong
subsidence behind the passing shortwave should be enough to suppress
any activity til later this afternoon. At that point, there is no
real forcing mechanism in terms of shortwaves, fronts, etc., but
there is a great deal of CAPE as a hot humid airmass persists over
the region. Model average puts max CAPE values around 1500 J/Kg by
late this afternoon. Soundings are quite stable in the low levels as
warm SW flow keeps a warm layer from about 3-6kft capping the
atmosphere. Still with that much CAPE around this warm humid airmass
(dew points in the 60s) can`t rule a few pop up showers from
occurring.

Looking forward, the overall pattern changes very little through the
weekend. Ridging will hold over the Great Lakes and actually looks
to strengthen on Saturday in response to a stronger wave deepening
in the base of the trough. This will push the jet and corridor of
better forcing further north and west. With the warm and humid
airmass holding firm over the area, chance pops will be featured
most days. This does not mean everyone will see rain everyday. Any
activity will be quite scattered with the lack of forcing mechanisms
thus it is difficult to impossible to zero in on any area days in
advance.

There are a couple opportunities in the coming days for more
widespread thunderstorm activity. First will be Friday afternoon as
the trough strengthens and sends a few weak waves northward up
through the area. Current timing looks to coincide with peak heating
which would then be able to utilize the +1000 J/kg of MUCAPE
available. Then on Sunday the main vorticity max at the base of the
trough looks to get picked up by the jet and pass up and around the
ridge. This would take it west then north of the area with the
trailing front swinging up through southern Michigan. This again
could be a day to watch for more widespread thunderstorm activity.

As for next week the pattern breaks down a bit becoming more zonal.
Could start Memorial Day off with some lingering showers but that
looks to get forced eastward by high pressure building in at the
surface and height increasing aloft. This will likely dry the region
out for a few days before the next trough approaches.

MARINE...

Low pressure moving through the western Great Lakes will pull a warm
front through lower Michigan and Lake Huron today. Clusters of
showers and thunderstorms will be most numerous along the front
early in the day. Light south wind will then maintain warm
temperatures and favorable marine conditions through Friday other
than areas of fog resulting from the warm air moving over the cold
lake water. Showers and thunderstorms will remain possible but will
be less organized and mainly confined to areas near land until
Friday night into Saturday. The next low pressure system is due in
the region by then and expected to produce greater coverage of rain
activity. Light south wind will shift light west as the low moves
through the western Great Lakes and pulls a weak front through lower
Michigan and Lake Huron by Sunday.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.

&&

$$

AVIATION.....BT
DISCUSSION...DRK
MARINE.......BT


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.




000
FXUS63 KAPX 261049
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
649 AM EDT THU MAY 26 2016

.SHORT TERM...(Today and tonight)
Issued at 346 AM EDT Thu May 26 2016

High impact weather potential: a few severe t-storms possible
this afternoon/evening in northern lower.

A warm front continues to slowly work northward into lower MI,
presently north of TVC and near HTL. This front should make the
Straits area today, maybe even clear it for a time, before low
pressure departing across northern Quebec helps drag it back
southward tonight. A nw-se oriented band of shra is moving into
eastern upper and n central lower mi, supported by broad
warm/moist advection but with overall waning instability.
Isolated shra/tsra activity is seen ahead of this band. Forecast
remains on the messy side, with precip trends the main concern.

Today...shra/tsra will continue to lift ne-ward across northern MI
this morning. Much of this activity will have wound down/exited by
12z/8am, with eastern upper/ne lower MI likely to see at least some
activity lingering a bit past that. Tricky cloud forecast behind
this. Central and northern WI has plenty of stratus/fog, but we
have almost no low clouds to speak of. Though ongoing precip
event may help generate some, we may not have enough time to
develop much before sun starts eating away at them. That said,
will be difficult for eastern upper MI to not have lower clouds
this morning (and perhaps longer), given the warm/moist pattern
and prevalence of marine influences. In northern lower, expect a
period of clearing behind precip band, rather quickly giving way
to cumulus development as temps rise into the 70s with dew points
in the lower 60s.

Sw 950mb winds are 10-15kt, low enough to allow for some lake breeze
development, but not like the bonanza we saw yesterday. That will be
one possible trigger mechanism to take advantage of a reasonably
healthy amount of instability. The Nam is much too aggressive;
more reasonable progs from the Sref-Mean and GFS advertise MLCape
in the 1-1.5k j/kg range. That is more than yesterday. We also
have more shear than yesterday, with 0-6km bulk shear of 30-35kt.
This is not overwhelmingly favorable, but not terrible. We
managed one severe storm yesterday (right on top of HTL), and
suspect we have the ingredients to get a few today. Not a major
outbreak by any stretch, but enough for a moderately busy
afternoon/evening. CIPS analogs suggest a 30-40 percent chance of
at least one svr here.

Sct afternoon/evening pops will be placed away from the Lake MI
shadow in northern lower. Will keep most other areas dry, though
far western Mackinac Co could see some spillover from decaying
convection in western upper MI late in the day.

Max temps from near 70f/lower 70s in eastern upper MI, to lower 80s
in much of northern lower.

Tonight...diurnal convection from the afternoon will fade out by
late evening. With little in the war of forcing, and the primary low
level jet pointing at southern Lake Mi, don/t anticipate something
new firing here overnight. Could we have enough low-level sw flow to
generate new convection over the Lake Mi cold dome, and/or support
MCS remnants as they try to move in from the west? Either scenario
is plausible; neither is one that the NCAR or NSSL hi-res ensembles
are terribly excited about. Think regardless that precip coverage
will not be impressive, if it even happens at all. Am so not a fan
of 20 pops (i.e. slight chance), but that/s what we and our
neighbors are already carrying, and will let that ride thru most of
the night in most areas. Will also allow for some fog overnight.
Min temps mid 50s to around 60f.

.LONG TERM...(Friday through Wednesday)
Issued at 346 AM EDT Thu May 26 2016

(5/27)Friday...Ridging at 500 mb begins to move a little more north
and east of the forecast area, putting us in the weak part of the
jet streak off to the west. Meanwhile, the sfc low looks to try and
move to the east into the Upper Great Lakes, at least on the ECMWF,
while the GFS is more to the west, in the Dakotas. Lower Michigan
looks to be in the warm sector, and with the weak 500 mb jet, and
difluence, the thunder chances increase through the morning and into
the afternoon. As noted earlier, with so much of the dynamics to the
west, like on the GFS, and once we lose the heat of the day, think
that our chances are just that, chances, instead of likely it was
during the day and evening hours. ECMWF is a little more bullish
with the sfc low and would continue with the rain showers, and
thunderstorms in NW Lower, and portions of E Upper.

(5/28)Saturday...Again we run into the same issue as we had for
Friday`s forecast, only this time, the models are a little closer,
with the sfc low to the west, as well as the 500 mb trough. So as
the trough moves closer, and the sunshine begins to destabilize
things, the chances for thunderstorms will go up through the day. Of
course, this looks to diminish once we lose the heat of the day and
the 500 mb shortwave trough rotates through the region, and the 700-
500mb layer dry slot begins to help cap off the convection during
the evening and overnight.

Extended (Sunday through Wednesday)...Low confidence pattern this
week with the ECMWF and the GFS at odds with the forecast after
Monday. The 500 mb shortwave trough moves through the Upper Great
Lakes so that Sunday has showers and thunderstorms, and it ends up
dry over N Lower Sunday night.  Models continue to look dry into
Monday night, although GFS has some qpf splattered about during the
day. Tuesday, both models start with 500 mb ridging in the Upper
Great Lakes, so that the day probably ends up dry. However, going
into the evening, the ECWMF pushes a 500 mb trough into the region,
while the GFS amplifies the ridge a bit and keeps the low (now a cut
off) back farther west. This remains the case through Wednesday as
the ECMWF says rain and the GFS is dry.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 648 AM EDT Thu May 26 2016

TSRA in the APN area late this afternoon/early evening. IFR in
fog/stratus very late tonight.

Warm front lifting across northern lower MI this morning. Ongoing
SHRA activity will diminish early on. Could be a stray cig/vsby
restriction very early on, but mainly VFR for the day today. Sct
TSRA will develop away from Lake MI this afternoon, getting at
least into the APN area. That will wane this evening, with only a
slight chance for a stray SHRA/TSRA for the rest of the night.
Will see some fog/stratus form after midnight, and am expecting
IFR conditions at all sites.

Light southerly breeze today. Winds nearly calm tonight.

&&

.MARINE...
Issued at 346 AM EDT Thu May 26 2016

Humid pattern with generally light southerly flow will persist.
This will maintain fog at times over the chilly waters of the
Great Lakes. Small craft advisories will not be needed in the near
future. Sporadic chances for showers and t-storms continue,
especially very early this morning.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JZ
LONG TERM...JSL
AVIATION...JZ
MARINE...JZ




000
FXUS63 KAPX 260747
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
347 AM EDT THU MAY 26 2016

.SHORT TERM...(Today and tonight)
Issued at 346 AM EDT Thu May 26 2016

High impact weather potential: a few severe t-storms possible
this afternoon/evening in northern lower.

A warm front continues to slowly work northward into lower MI,
presently north of TVC and near HTL. This front should make the
Straits area today, maybe even clear it for a time, before low
pressure departing across northern Quebec helps drag it back
southward tonight. A nw-se oriented band of shra is moving into
eastern upper and n central lower mi, supported by broad
warm/moist advection but with overall waning instability.
Isolated shra/tsra activity is seen ahead of this band. Forecast
remains on the messy side, with precip trends the main concern.

Today...shra/tsra will continue to lift ne-ward across northern MI
this morning. Much of this activity will have wound down/exited by
12z/8am, with eastern upper/ne lower MI likely to see at least some
activity lingering a bit past that. Tricky cloud forecast behind
this. Central and northern WI has plenty of stratus/fog, but we
have almost no low clouds to speak of. Though ongoing precip
event may help generate some, we may not have enough time to
develop much before sun starts eating away at them. That said,
will be difficult for eastern upper MI to not have lower clouds
this morning (and perhaps longer), given the warm/moist pattern
and prevalence of marine influences. In northern lower, expect a
period of clearing behind precip band, rather quickly giving way
to cumulus development as temps rise into the 70s with dew points
in the lower 60s.

Sw 950mb winds are 10-15kt, low enough to allow for some lake breeze
development, but not like the bonanza we saw yesterday. That will be
one possible trigger mechanism to take advantage of a reasonably
healthy amount of instability. The Nam is much too aggressive;
more reasonable progs from the Sref-Mean and GFS advertise MLCape
in the 1-1.5k j/kg range. That is more than yesterday. We also
have more shear than yesterday, with 0-6km bulk shear of 30-35kt.
This is not overwhelmingly favorable, but not terrible. We
managed one severe storm yesterday (right on top of HTL), and
suspect we have the ingredients to get a few today. Not a major
outbreak by any stretch, but enough for a moderately busy
afternoon/evening. CIPS analogs suggest a 30-40 percent chance of
at least one svr here.

Sct afternoon/evening pops will be placed away from the Lake MI
shadow in northern lower. Will keep most other areas dry, though
far western Mackinac Co could see some spillover from decaying
convection in western upper MI late in the day.

Max temps from near 70f/lower 70s in eastern upper MI, to lower 80s
in much of northern lower.

Tonight...diurnal convection from the afternoon will fade out by
late evening. With little in the war of forcing, and the primary low
level jet pointing at southern Lake Mi, don/t anticipate something
new firing here overnight. Could we have enough low-level sw flow to
generate new convection over the Lake Mi cold dome, and/or support
MCS remnants as they try to move in from the west? Either scenario
is plausible; neither is one that the NCAR or NSSL hi-res ensembles
are terribly excited about. Think regardless that precip coverage
will not be impressive, if it even happens at all. Am so not a fan
of 20 pops (i.e. slight chance), but that/s what we and our
neighbors are already carrying, and will let that ride thru most of
the night in most areas. Will also allow for some fog overnight.
Min temps mid 50s to around 60f.

&&

.LONG TERM...(Friday through Wednesday)
Issued at 346 AM EDT Thu May 26 2016

(5/27)Friday...Ridging at 500 mb begins to move a little more north
and east of the forecast area, putting us in the weak part of the
jet streak off to the west. Meanwhile, the sfc low looks to try and
move to the east into the Upper Great Lakes, at least on the ECMWF,
while the GFS is more to the west, in the Dakotas. Lower Michigan
looks to be in the warm sector, and with the weak 500 mb jet, and
difluence, the thunder chances increase through the morning and into
the afternoon. As noted earlier, with so much of the dynamics to the
west, like on the GFS, and once we lose the heat of the day, think
that our chances are just that, chances, instead of likely it was
during the day and evening hours. ECMWF is a little more bullish
with the sfc low and would continue with the rain showers, and
thunderstorms in NW Lower, and portions of E Upper.

(5/28)Saturday...Again we run into the same issue as we had for
Friday`s forecast, only this time, the models are a little closer,
with the sfc low to the west, as well as the 500 mb trough. So as
the trough moves closer, and the sunshine begins to destabilize
things, the chances for thunderstorms will go up through the day. Of
course, this looks to diminish once we lose the heat of the day and
the 500 mb shortwave trough rotates through the region, and the 700-
500mb layer dry slot begins to help cap off the convection during
the evening and overnight.

Extended (Sunday through Wednesday)...Low confidence pattern this
week with the ECMWF and the GFS at odds with the forecast after
Monday. The 500 mb shortwave trough moves through the Upper Great
Lakes so that Sunday has showers and thunderstorms, and it ends up
dry over N Lower Sunday night.  Models continue to look dry into
Monday night, although GFS has some qpf splattered about during the
day. Tuesday, both models start with 500 mb ridging in the Upper
Great Lakes, so that the day probably ends up dry. However, going
into the evening, the ECWMF pushes a 500 mb trough into the region,
while the GFS amplifies the ridge a bit and keeps the low (now a cut
off) back farther west. This remains the case through Wednesday as
the ECMWF says rain and the GFS is dry.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 125 AM EDT Thu May 26 2016

A period of MVFR/possible IFR with a band of showers and isolated
to scattered storms today.

A front and sfc low pressure will cross nrn Michigan today with a
band of showers and some storms working into NW lower through noon
or early afternoon....and across NE lower this afternoon. The severe
weather threat is quite minimal...and so is the probability of an
actual storm crossing the airports. Best chance is more likely
TVC/MBL and APN. Confidence is less than average...but MVFR cigs
could precede the showers/storms...and will also be possible along
the band itself. Any low cloud should get lifted out with time
behind the passage of the front...leaving just small chances for
additional light showers. Winds will generally remain below 10kts
with some gustiness expected at APN. Winds shift pretty abruptly out
of the west behind the front...and are expected to stay at or below
10kts.

&&

.MARINE...
Issued at 346 AM EDT Thu May 26 2016

Humid pattern with generally light southerly flow will persist.
This will maintain fog at times over the chilly waters of the
Great Lakes. Small craft advisories will not be needed in the near
future. Sporadic chances for showers and t-storms continue,
especially very early this morning.

&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JZ
LONG TERM...JSL
AVIATION...Dickson
MARINE...JZ




000
FXUS63 KMQT 252355
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
755 PM EDT WED MAY 25 2016

.SHORT TERM...(This evening through Thursday)
Issued at 257 PM EDT WED MAY 25 2016

Upper air pattern consists of a trough in the wrn U.S. with several
shortwaves in the central plains. These shortwaves will be the
weather maker for tonight and Thu as one of the shortwaves ejects
out of the wrn U.S. trough. Deeper moisture returns tonight and
remains over the area into Thu. Nam shows some strong isentropic
lift on I300K surfaces tonight with deep moisture moving through
the cwa. GFS and ECMWF show about the same thing as well.

Looks like a decent chance for rain tonight and have likely pops
spreading from west to east overnight. Could see with this whole
event 0.25-0.75 inch of rain with the highest amounts in the western
cwa through Thu afternoon. Looks like late tonight there would be a
break in the morning...then confidence becomes lower in the
afternoon for pops. Some models are going completely dry while
others are putting out some qpf. Went middle of the road and could
be conceivable after a break in the morning...could see
redevelopment of showers and thunderstorms late in the afternoon
with heating of the day and lake breeze boundaries helping to aid in
the convection that forms and have some slight chance and low chance
pops to account for this on land. Did not make too many changes to
the going forecast overall. Did keep some mention of fog in for
tonight through Thu morning for the area as winds will be light
tonight and low level moisture will again be abundant with the rain
developing.

.LONG TERM...(Thursday night through Wednesday)
Issued at 444 PM EDT WED MAY 25 2016

Periods of showers and some thunderstorms with temperatures running
slightly above average through the holiday weekend.

Quite a mess of a forecast into next week. Broad troughing across
the western U.S. will send several waves of energy NE across the
Plains around broad ridging across the eastern U.S. Timing of
shortwaves/WAA/jets vary among the models, so pinpointing exact
times of precip is nearly impossible. With ample low-level moisture
and some daytime heating, any piece of energy will be able to force
at least some shower/storm activity.

An axis on the eastern ridge will bring mostly dry conditions to the
CWA Thursday night into Friday morning, though a few stray showers
cannot be ruled out. By the afternoon, a subtle mid-level shortwave
and weakly coupled upper jet pattern will induce a shield of showers
and thunderstorms that will spread NNE across the Upper MS Valley
and western Great Lakes. At this time, the precip should move in by
the afternoon hours, thus limiting the amount of destabilization.
However, if the energy arrives later in the afternoon, increased
destabilization combined with 25-35kts of 1-6km shear will be enough
to produce some strong storms.

Continued moisture advection with ripples of energy moving northward
from the western trough will result in periods of showers and some
thunderstorms Friday through much of the day Saturday. It is
possible that some locations across mainly the west could see as
much as two inches of rain during this period.

By Sunday, the pattern transitions to a more zonal look. Chances for
showers and storms will continue during this transition on Sunday
before mostly dry conditions are expected late Memorial Day into
Tuesday as weak upper ridging moves across the Upper MS Valley and
Great Lakes region. Another more potent trough is then progged to
bring showers and storms for Wednesday.
&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 745 PM EDT WED MAY 25 2016

Area of rain showers lifting up from northern WI will spread across
Upper MI this evening and overnight. Thunderstorms will be isolated
at best so will leave those out of the TAFs. Conditions will
deteriorate with the rain moving in this evening and into the
overnight, eventually lowering to lifr/vlifr at all sites. Expect
conditions to gradually improve Thu morning reaching VFR by Thu
afternoon at all sites. &&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 257 PM EDT WED MAY 25 2016

A period of NE winds up to 25 knots is expected over the western
lake today into early tonight and across the eastern lake late
tonight into Thu morning as low pressure develops over the plains
and moves to the Upper MS valley. Otherwise, expect winds at or
below 20 knots through the forecast period. Fog will continue to be
a problem at times and will be dependent on the rain that falls.
For now, went with widespread fog at times.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&

$$

SHORT TERM...07
LONG TERM...Kluber
AVIATION...Voss
MARINE...07




000
FXUS63 KDTX 252316
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
716 PM EDT WED MAY 25 2016


.AVIATION...

Continuation of a stable environment through at least the first half
of the night will again leave all SE Michigan terminals under simply
some degree of high cloud /above 6000 ft/.  Loss of heating will
prompt the reduction in wind speed magnitude through the latter half
of the evening.  There remains the potential for ongoing convective
activity now over Chicago to expand eastward overnight, reaching SE
Michigan during the early-mid morning hours /08z-13z/.  Any activity
likely arrives locally in a much weaker state, diminishing the
likelihood for a greater coverage of thunder.  This will continue
to preclude any mention at this time.

FOR DTW...Quiet conditions through 08z, window for showers
thereafter through 12z.  Very low probability for a thunderstorm to
emerge in the vicinity of the terminal during that time.  Will
refrain from a defined mention at this stage, allowing subsequent
trends upstream dictate the need for a specific inclusion.

//DTW Threshold Probabilities...

* Low for ceiling 5000 FT or less late tonight and Thursday.

* Low for thunderstorms affecting DTW/D21 air space late tonight and
  Thursday.

&&

.PREV DISCUSSION...
Issued at 351 PM EDT Wed May 25 2016

DISCUSSION...

Persistent upper level ridging along with another day of dry and
modest surface dewpoints has resulted in an overachievement of
surface temperatures across much of the southern 2/3rds to 3/4ths of
the cwa. Afternoon temperatures easily reached into the middle 80s.
A rather weak frontal boundary has become increasingly organized
over far northern portions of the cwa generally along and north of
the M 46 corridor. This feature resides in a zone of soft lower
tropospheric confluence or shearing deformation. The vertical
circulation tied to the boundary has been deep enough to aid in some
isolated elevated convective showers. Explicit hi-res model output
suggests a duration of continued shower development along this
frontal boundary into the afternoon, potentially as late as the 01z
timeframe. Could also see the activity focus west of the Tri Cities
region with time, possibly over sections of far western lower
Michigan. Surface observations near the boundary are still reporting
some 60 degree dewpoints. Forecast sounding analysis along with with
SPC mesoanalysis suggests that around 750 J/kg of MLCAPE will be the
high water mark or CAPE ceiling the environment will be up against
for the remainder of this afternoon and evening. No strong or severe
thunderstorms are expected with the marginal instability and lack of
shear.

Model data is also suggesting that rogue shower activity may
be possible across the far southern CWA south of Detroit as very
weak dcva will lift northward. The very weak midlevel convective
activity that has been on regional mosaic over Ohio is associated
with this forcing. Cannot rule it out the showers completely, but
not giving it much credence either because of the strength of the
upper level riding aloft.

Flow trajectories are forecasted to turn cyclonic for a time tonight
and tomorrow over portions of the upper Midwest as a deep midlevel
trough lifts into the Northern Plains. This inflection point in the
flow will be tied to the entrance region of a new upper level
jetstreak and will harbor a respectable arc of shortwave energy. It
is along this arc of cyclonic vorticity that models have been
supporting old convective showers remnants to push ahead of the cva
and through the CWA between 9-14Z. The forecast item for late
tonight is what sort of coverage of showers and possible
thunderstorms will exist as this forcing enter southeastern
Michigan. The forecast is now muddied as some various solutions are
suggesting a break point or precipitation void over southeastern
Michigan with the early Thursday activity. Have to say the signs
for widespread precipitation is not overly convincing with an overall
lack of big picture forcing. Semich will reside in an unfavorable
right exit region to the upper level jet, while really remaining
more tucked under the upper level ridge and higher geopotential
heights. The bottomline is that any showers, thunderstorms or old MCS
complex that arrives will be weakening. The solution space is
literally all over the map with POPs, anywhere from low chance pops
to categoricals. Decided to maintain much of the inherited forecast
and continue the likely pops. No strong or severe weather is
expected through Thursday morning.

Latest model data suggests some potential exists for severe weather
Thursday afternoon and evening conditional to storm development.
Main support for vigorous updrafts is on the thermodynamic side as
forecast soundings show a legitimate chance for SBCAPE and MLCAPE in
excess of 2000 j/kg by late Thursday afternoon. The CAPE profile
looks contingent on mid 60s dewpoints. Given a reasonable proximity
of mid 60s dewpoints upstream today and the higher likelihood for
early day precipitation and potential moistening of near surface
layer, 2000 J/kg seems reasonable. The main limitation for severe
weather in the short term remains the weak environmental wind
profile and weak shear. The forecasted 0-6km bulk shear is expected
to b 20 knots to possibly as high as 30 knots particularly north of
the M 46 corridor. Combine all of these factors and the idea is that
if storms do develop, severe wind gusts and large hail will be
possible. Soundings do show some capping issues at roughly 5000 ft
agl to contend with. As far as what sort of trigger or focusing
mechanism exists, that remains a good question as there really is
not one. The nam is suggesting that midlevel convective development
may occur in and along the Saginaw Bay region Thursday evening (Fri
00/03Z) as a tail of convergence or cyclonic vorticity settles
southward off of the U.P. of Michigan and Lake Superior shortwave.
In these high cape scenarios all bets are off when a perturbation
is introduced. A very interesting setup and worth monitoring.

Another old nocturnal low level jet cycle is forecasted to lift into
southeastern Michigan on Friday. The overall wind profile is not
expected to change much which really holds things down as a
persistence forecast. Model data continues to suggest some remnant
MCS system could slide across souther lower Michigan on Friday.
Maintainted much of the inherited forecast with likely POPs for
showers and thunderstorms Friday afternoon and Friday evening.
However, predictability and forecast confidence is low on basin
average QPF, liquid amounts.

The pattern will remain active for the start of the weekend and
possibly for the beginning of Memorial Day as Southeast Michigan
remains between troughing to the north and ridging from high
pressure to the south.  A couple of waves riding through the flow
will allow for continued rain/storm chances both Saturday and
Sunday, especially in the afternoons as the diurnal component kicks
in.  Depending on the timing of ridging building in over the area on
Monday, the day may remain dry although at this current time slight
chances for showers are still in the forecast.  Chances decrease
going through Memorial Day and conditions should quiet down Monday
night into Tuesday as upper level ridging builds in.

MARINE...

A stationary front across southern Lake Huron is spawning a few
showers/thunderstorms.  This front will begin lifting north
overnight then become semi stationary through the weekend. For all
marine areas a southerly component to the flow will persist through
the weekend with periodic disturbances producing shower and
thunderstorm chances.  Some fog is possible again tonight across
northern Lake Huron as dew points in the 50s continue to advect over
the colder water.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&

$$

AVIATION.....MR
DISCUSSION...CB/SS
MARINE.......DRC


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.




000
FXUS63 KDTX 251951
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
351 PM EDT WED MAY 25 2016

.DISCUSSION...

Persistent upper level ridging along with another day of dry and
modest surface dewpoints has resulted in an overachievement of
surface temperatures across much of the southern 2/3rds to 3/4ths of
the cwa. Afternoon temperatures easily reached into the middle 80s.
A rather weak frontal boundary has become increasingly organized
over far northern portions of the cwa generally along and north of
the M 46 corridor. This feature resides in a zone of soft lower
tropospheric confluence or shearing deformation. The vertical
circulation tied to the boundary has been deep enough to aid in some
isolated elevated convective showers. Explicit hi-res model output
suggests a duration of continued shower development along this
frontal boundary into the afternoon, potentially as late as the 01z
timeframe. Could also see the activity focus west of the Tri Cities
region with time, possibly over sections of far western lower
Michigan. Surface observations near the boundary are still reporting
some 60 degree dewpoints. Forecast sounding analysis along with with
SPC mesoanalysis suggests that around 750 J/kg of MLCAPE will be the
high water mark or CAPE ceiling the environment will be up against
for the remainder of this afternoon and evening. No strong or severe
thunderstorms are expected with the marginal instability and lack of
shear.

Model data is also suggesting that rogue shower activity may
be possible across the far southern CWA south of Detroit as very
weak dcva will lift northward. The very weak midlevel convective
activity that has been on regional mosaic over Ohio is associated
with this forcing. Cannot rule it out the showers completely, but
not giving it much credence either because of the strength of the
upper level riding aloft.

Flow trajectories are forecasted to turn cyclonic for a time tonight
and tomorrow over portions of the upper Midwest as a deep midlevel
trough lifts into the Northern Plains. This inflection point in the
flow will be tied to the entrance region of a new upper level
jetstreak and will harbor a respectable arc of shortwave energy. It
is along this arc of cyclonic vorticity that models have been
supporting old convective showers remnants to push ahead of the cva
and through the CWA between 9-14Z. The forecast item for late
tonight is what sort of coverage of showers and possible
thunderstorms will exist as this forcing enter southeastern
Michigan. The forecast is now muddied as some various solutions are
suggesting a break point or precipitation void over southeastern
Michigan with the early Thursday activity. Have to say the signs
for widespread precipitation is not overly convincing with an overall
lack of big picture forcing. Semich will reside in an unfavorable
right exit region to the upper level jet, while really remaining
more tucked under the upper level ridge and higher geopotential
heights. The bottomline is that any showers, thunderstorms or old MCS
complex that arrives will be weakening. The solution space is
literally all over the map with POPs, anywhere from low chance pops
to categoricals. Decided to maintain much of the inherited forecast
and continue the likely pops. No strong or severe weather is
expected through Thursday morning.

Latest model data suggests some potential exists for severe weather
Thursday afternoon and evening conditional to storm development.
Main support for vigorous updrafts is on the thermodynamic side as
forecast soundings show a legitimate chance for SBCAPE and MLCAPE in
excess of 2000 j/kg by late Thursday afternoon. The CAPE profile
looks contingent on mid 60s dewpoints. Given a reasonable proximity
of mid 60s dewpoints upstream today and the higher likelihood for
early day precipitation and potential moistening of near surface
layer, 2000 J/kg seems reasonable. The main limitation for severe
weather in the short term remains the weak environmental wind
profile and weak shear. The forecasted 0-6km bulk shear is expected
to b 20 knots to possibly as high as 30 knots particularly north of
the M 46 corridor. Combine all of these factors and the idea is that
if storms do develop, severe wind gusts and large hail will be
possible. Soundings do show some capping issues at roughly 5000 ft
agl to contend with. As far as what sort of trigger or focusing
mechanism exists, that remains a good question as there really is
not one. The nam is suggesting that midlevel convective development
may occur in and along the Saginaw Bay region Thursday evening (Fri
00/03Z) as a tail of convergence or cyclonic vorticity settles
southward off of the U.P. of Michigan and Lake Superior shortwave.
In these high cape scenarios all bets are off when a perturbation
is introduced. A very interesting setup and worth monitoring.

Another old nocturnal low level jet cycle is forecasted to lift into
southeastern Michigan on Friday. The overall wind profile is not
expected to change much which really holds things down as a
persistence forecast. Model data continues to suggest some remnant
MCS system could slide across souther lower Michigan on Friday.
Maintainted much of the inherited forecast with likely POPs for
showers and thunderstorms Friday afternoon and Friday evening.
However, predictability and forecast confidence is low on basin
average QPF, liquid amounts.

The pattern will remain active for the start of the weekend and
possibly for the beginning of Memorial Day as Southeast Michigan
remains between troughing to the north and ridging from high
pressure to the south.  A couple of waves riding through the flow
will allow for continued rain/storm chances both Saturday and
Sunday, especially in the afternoons as the diurnal component kicks
in.  Depending on the timing of ridging building in over the area on
Monday, the day may remain dry although at this current time slight
chances for showers are still in the forecast.  Chances decrease
going through Memorial Day and conditions should quiet down Monday
night into Tuesday as upper level ridging builds in.

&&

.MARINE...

A stationary front across southern Lake Huron is spawning a few
showers/thunderstorms.  This front will begin lifting north
overnight then become semi stationary through the weekend. For all
marine areas a southerly component to the flow will persist through
the weekend with periodic disturbances producing shower and
thunderstorm chances.  Some fog is possible again tonight across
northern Lake Huron as dew points in the 50s continue to advect over
the colder water.

&&

.PREV DISCUSSION...
Issued at 124 PM EDT Wed May 25 2016

AVIATION...

A weak surface boundary between FNT and MBS will lift slowly
northward this afternoon. High based cu has formed along this
boundary and there will be a slight chc for a shower or thunderstorm
to develop during the afternoon and evening along this but too small
chc to add to tafs.   Elsewhere this afternoon and evening,
southwesterly flow will continue to gradually advect in more
moisture leading to diurnal cu fields generally aoa 6k ft. There
remains a slight chc for a shower or thunderstorm this evening
across southeastern tafs. Tonight a mid level wave will eject out of
the Missouri Valley and move through lower Michigan. This will cause
surface winds to back slightly overnight before veering again to the
southwest Thursday. This wave will produce enough lift to overcome
weak capping allowing for scattered coverage of showers to develop.
There will also be a chance for some thunder but probability and
coverage is too low to include in tafs. Fog around 5 miles is also
likely with and shortly after shower passage.

FOR DTW...a slight chc exist this evening for a shower or
thunderstorm from heating of day and disturbance passing across
northern Ohio. scattered showers are likely to swing through
during the 06-12z time frame with a slight chance for thunder.
Ceilings should remain vfr.

//DTW Threshold Probabilities...

* Low for ceiling 5000 FT or less tonight and Thursday.

* Low for thunderstorms affecting DTW/D21 air space.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&

$$

DISCUSSION...CB/SS
MARINE.......DRC
AVIATION.....DRC


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.




000
FXUS63 KAPX 251738
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
138 PM EDT WED MAY 25 2016

.UPDATE...
Issued at 1050 AM EDT Wed May 25 2016

Strong May sun starting to work its magic, with a noticeable decrease
in fog across the tip of the mitt in the last few hours. Stratus
deck starting to succumb too, although may take several more hours
to complete that process, especially up across the straits region.
South of M-68, sun is plentiful, and temperatures are definitely
responding accordingly, with widespread readings in the lower 70s.
These will only continue to trend upward, with afternoon
temperatures topping 80 degrees for much of the interior of
northern lower. Somewhat "cooler" for those tip of the mitt
counties and eastern upper, but readings in the 70s there are still
several degrees above normal.

As for rain chances...that will be tied to expected instability
development as larger scale forcing mechanisms are largely non-
existent. Per modification of local 12z sounding and high res
instability progs, several hundred joules/kg of mean layer cape
will develop this afternoon, just enough for parcels to scrap by
h6 centered cap. Wind fields are light, with background light east
synoptic flow butting up against lake Michigan induced stable
layer and forced ascent through the highlands likely being the
triggers to drive shower and storm development. Coverage will
remain scattered, and centered largely south of M-32. No severe
weather anticipated given marginal instability and shear values.

All in all, inherited forecast has above handled well, with
changes relegated to real-time temperature and cloud trends.

&&

.SHORT TERM...(Today and tonight)
Issued at 356 AM EDT Wed May 25 2016

High impact weather potential: t-storms returning this afternoon
and especially tonight.

Weak cold front is somewhat difficult to pick out, but appears to
have settled a bit south of TVC/APN. The front will drift south into
central lower MI before stalling this morning. It will return north
tonight, before getting caught and absorbed by a warm front now in
KS/southern MO. Lingering shra activity is moving out across Lake
Huron, giving us a lull in precip for the morning and early
afternoon. There are two possible sources of precip after that:
any chance that deep convection can fire this afternoon, and then
a true surge of warm/moist air arriving tonight.

Today...post-frontal band of fog/stratus has settled into the
straits region and eastern upper mi. Some fog has also formed
ahead of this across far northern lower, thanks to a rain-cooled
and -moistened airmass. Fog south of CVX/Petoskey/Rogers is thin
and will erode quickly this morning...with little to limit strong
late May sunshine. Straits/upper MI cloud cover is thicker and
will be considerably more stubborn (marine influences will help
maintain it). But do expect that cloud deck to break down around
midday.

Meanwhile, despite being in the /cool/ sector, northern lower will
be baking away. There is a touch of cirrus wafting in from the sw
now, and will become more prevalent with time as the day proceeds.
But with plenty of sunshine otherwise and a mild start to the
morning, highs will be somewhat toasty again today. A tendency
toward a light se synoptic wind will keep the Lake Huron
coastline cooler in the 70s (even cooler yet along the immediate
beaches). Same applies for eastern upper. But the rest of northern
lower will reach the lower and perhaps mid 80s again.

Dew points have finally jumped dramatically thanks to the nighttime
SHRA activity. Outside of marine-influenced locales, surface dew
points in the mid 50s will be common. This results in reasonable
instability building this afternoon near/south of M-72. Mlcapes
should approach 1k j/kg by late in the afternoon. Model soundings
do portray a touch of capping trying to arise this afternoon at
about 625mb. Said soundings suggest this cap will not hold, but
worth noting that model soundings generally underforecast capping.
Background se synoptic wind will be weak enough to permit lake
breezes, so suspect we will have the trigger needed to get past
capping aloft.

So, after a dry morning, will advertise a chance of pm t-storms in
southern sections, away from the coastlines. This is largely in
agreement with the going forecast. Shear is unimpressive, with less
than 15kt of wind up thru 700mb, and 0-6km bulk shear around 20kt.
Not much in the way of a svr threat, though if instability ends up
toward the high end of estimates, something brief/marginal is not
completely out of the question.

Tonight...warm front will charge into northern lower MI overnight.
850mb dew points will increase into the lower teens, and surface dew
points behind the warm front will push 60f overnight. This airmass
enters the region on 25-35kt 850mb winds. Outside of lingering
daytime convection, the mid-evening hours look largely dry. But that
lingering convection will stay healthier than one would otherwise
expect as better 850mb theta-e advection kicks in. More widespread
precip is likely late evening and overnight as the surface and 850mb
warm fronts race in. Not quite ready to kick pops to categorical
(this is convection we/re dealing with), but 70 pops at least will
suffice for overnight. Qpf totals of 0.25-0.50 look most likely. Min
temps lower 50s to lower 60s.

.LONG TERM...(Thursday through Tuesday)
Issued at 356 AM EDT Wed May 25 2016

...Warm and muggy with showers and storms into the holiday weekend...

The pattern over the next few days still looks unsettled at times
with climbing humidity levels along with decent chances for rounds
of showers and thunderstorms. This will be the result of numerous
pieces of energy ejecting out of a broad long wave trough which will
continue to stretch from the Pacific Northwest into the northern
Plains through early next week. There still could be some strong to
severe storms across northern Michigan Thursday as a wing of forcing
sweeps across the region. The best shot for any stronger storms to
form looks like it`s over north central and northeast lower Michigan
as models generate 0-1 km ML Cape of between 1500 and 2500 j/kg and
little convective inhibition. Wind fields are decent Thursday
afternoon with 0-6 km bulk shear of 35 to 40 knots (strongest north)
but generally under 30 knots for the remainder of the period as the
main jet stream remains focused north and west of the region.
Moisture is on the increase with PW/s generally increasing to
between 1.25 and 1.50 inches so we could get into some heavy
rainers. A more widespread area of showers with embedded
thunderstorms is likely late Friday into Saturday as energy/moisture
advect into the region. Besides the system driven showers, expect
diurnally induced showers and storms to fire with a limited
potential for isolated severe storms over the coming days.
Temperatures through the period are still expected to run a few
degrees above normal for the end of May.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 131 PM EDT Wed May 25 2016

Patch of stratus continues to impact KPLN, and looks to do so for
a few more hours. Otherwise, just some cirrus and high based cu
across northern Michigan. These cu will continue to develop, with
isolated/scattered showers and thunderstorms expected this
afternoon. Not convinced these will impact the taf sites, with
most coverage expected across the interior. Band of more organized
showers spreads overhead tonight, although cigs look to be
relatively high based. Will need to monitor for some isolated
heavy rain producing storms, which could cause brief restrictions
at the airports. Another round of stratus and mist late tonight
and early Thursday morning, although once again not completely
sold on how widespread it will be. Some improvement expected
Thursday morning as warming helps raise cigs. Light winds through
the forecast.

&&

.MARINE...
Issued at 356 AM EDT Wed May 25 2016

Somewhat more humid airmass is already in place thanks to last
nights rain. That is contributing to fog, especially north of Gd
Trav Bay and Rogers City, including around eastern upper MI. An
even more humid airmass invades late tonight as a warm front
moves in. Marine fog/stratus will be an occasional issue thru the
forecast. Winds/waves will generally be light...from the se
today...becoming s to sw tonight.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...MSB
SHORT TERM...JZ
LONG TERM...Sullivan
AVIATION...MSB
MARINE...JZ




000
FXUS63 KGRR 251531
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1131 AM EDT WED MAY 25 2016

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 330 AM EDT Wed May 25 2016

Very warm and humid weather can be expected through Memorial Day
weekend. Unstable conditions will lead to periodic showers and
thunderstorms but the rest of this week and the holiday weekend will
not be a total washout.

&&

.SHORT TERM...(Today through Friday)
Issued at 330 AM EDT Wed May 25 2016

Showers along/ahead of weakening sfc frontal boundary over
central lwr mi have dissipated so will start with a dry fcst this
morning. The front continues to wash out today but weak sfc
convergence may be just enough to support diurnal development around
Mt Pleasant/Clare/Big Rapids/Evart areas this afternoon. Also some
isolated cells possible along lake breeze front later today.

Fcst soundings after 18z from the RAP indicate that any convection
which develops should have high bases around 5000-7000 ft AGL with
inverted V/dry sub cloud layer likely. This could support some
locally high wind gusts. Guidance dew points today look too high
since deep mixing shown in the fcst soundings should mix down drier
air. Afternoon dew points of 50-55 seem more reasonable than the 60s
shown in much of the guidance. Believe that cape progs from GFS/NAM
are accordingly way too high and sbcapes should struggle to exceed
1000 J/KG. Also the mixing down of drier air could lead to another
day of highs exceeding guidance.

Likely pops are still very much in order for tonight as water vapor
imagery clearly shows a shortwave upstream that`s headed our way.
Passage of this feature, and the sfc warm front, Thursday morning
will bring in the more humid/unstable condition. Trigger for
scattered convection on Thursday and Friday afternoons is
questionable but storms should favor areas of enhanced sfc
convergence such as the lake breeze front. The svr threat is marginal
with deep layer shear generally below 30 kts.

.LONG TERM...(Friday night through Tuesday)
Issued at 330 AM EDT Wed May 25 2016

We expect that the unsettled weather pattern expected to be in place
for the short term will linger into the long term portion of the
forecast. Deep sw flow will remain in place through the weekend as
the upper low across the sw portion of the country lifts NNE through
the weekend. This will also keep better moisture moving in from the
Gulf of Mexico with a s/sw flow at the surface. These factors will
lead to instability remaining present that could be used with any
short wave that rides through.

The upper low is expected to move by the area Sunday night. This
should tend to diminish the rain chances a bit for Mon and Tue next
week. The upper flow will become zonal for a short time, and the low
level flow will not be tapping Gulf moisture for a short period.
There is not really any cooler air coming into the area in the wake
of this system with it remaining well north, so temperatures will
likely remain in the 80s for highs.

The trend for early next week is for the chances of rain to be a
little less than previously thought. We have kept the low chc in for
now. Ridging will build over the area in response to another digging
trough across the wrn portion of the country. The low level flow
will not be conducive for strong moisture advection. Temps should
end up well in the 80s with the building heights, and a lack of
cooler air behind the system moving through on the weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1126 AM EDT Wed May 25 2016

Vfr conditions will continue at all the terminals this afternoon
and early evening. There is a very small chance for an isolated
shower or storm mid to late afternoon but potential for this to
occur is too low to warrant inclusion in any of the terminal
fcsts.

A few showers and thunderstorms will develop during the mid to
late evening hours. Conditions at all the terminals late this
evening and overnight will gradually deteriorate from vfr to mvfr
due to the scattered showers and storms followed by development
of fog during the early morning hours. Conditions may deteriorate
to ifr Thursday morning as ceilings lower.

&&

.MARINE...
Issued at 330 AM EDT Wed May 25 2016

Areas of dense fog will become a concern over Lk MI tonight and
beyond as dew points above 60 arrive.


&&

.HYDROLOGY...
Issued at 152 PM EDT Tue May 24 2016

Periodic showers and thunderstorms will move through the region
especially Wednesday night, Friday and Saturday. However, overall
rainfall amounts will likely be variable across the area. Some
locations may pick up well over an inch of rain through the
weekend, while other places much less. A good portion of the more
widespread rainfall could occur Wednesday night as a warm front
lifts through. Thursday and beyond will feature some diurnally
driven convection that could produce locally heavy rainfall...but
basin average rainfall is not expected to be excessive. Smaller
creeks and rivers could be susceptible to quick rises given this
setup. Main stem river flooding does not look likely.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.
&&

$$

SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...NJJ
AVIATION...Laurens
HYDROLOGY...Hoving
MARINE...Meade




000
FXUS63 KGRR 251154
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
754 AM EDT WED MAY 25 2016

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 330 AM EDT Wed May 25 2016

Very warm and humid weather can be expected through Memorial Day
weekend. Unstable conditions will lead to periodic showers and
thunderstorms but the rest of this week and the holiday weekend will
not be a total washout.

&&

.SHORT TERM...(Today through Friday)
Issued at 330 AM EDT Wed May 25 2016

Showers along/ahead of weakening sfc frontal boundary over
central lwr mi have dissipated so will start with a dry fcst this
morning. The front continues to wash out today but weak sfc
convergence may be just enough to support diurnal development around
Mt Pleasant/Clare/Big Rapids/Evart areas this afternoon. Also some
isolated cells possible along lake breeze front later today.

Fcst soundings after 18z from the RAP indicate that any convection
which develops should have high bases around 5000-7000 ft AGL with
inverted V/dry sub cloud layer likely. This could support some
locally high wind gusts. Guidance dew points today look too high
since deep mixing shown in the fcst soundings should mix down drier
air. Afternoon dew points of 50-55 seem more reasonable than the 60s
shown in much of the guidance. Believe that cape progs from GFS/NAM
are accordingly way too high and sbcapes should struggle to exceed
1000 J/KG. Also the mixing down of drier air could lead to another
day of highs exceeding guidance.

Likely pops are still very much in order for tonight as water vapor
imagery clearly shows a shortwave upstream that`s headed our way.
Passage of this feature, and the sfc warm front, Thursday morning
will bring in the more humid/unstable condition. Trigger for
scattered convection on Thursday and Friday afternoons is
questionable but storms should favor areas of enhanced sfc
convergence such as the lake breeze front. The svr threat is marginal
with deep layer shear generally below 30 kts.

.LONG TERM...(Friday night through Tuesday)
Issued at 330 AM EDT Wed May 25 2016

We expect that the unsettled weather pattern expected to be in place
for the short term will linger into the long term portion of the
forecast. Deep sw flow will remain in place through the weekend as
the upper low across the sw portion of the country lifts NNE through
the weekend. This will also keep better moisture moving in from the
Gulf of Mexico with a s/sw flow at the surface. These factors will
lead to instability remaining present that could be used with any
short wave that rides through.

The upper low is expected to move by the area Sunday night. This
should tend to diminish the rain chances a bit for Mon and Tue next
week. The upper flow will become zonal for a short time, and the low
level flow will not be tapping Gulf moisture for a short period.
There is not really any cooler air coming into the area in the wake
of this system with it remaining well north, so temperatures will
likely remain in the 80s for highs.

The trend for early next week is for the chances of rain to be a
little less than previously thought. We have kept the low chc in for
now. Ridging will build over the area in response to another digging
trough across the wrn portion of the country. The low level flow
will not be conducive for strong moisture advection. Temps should
end up well in the 80s with the building heights, and a lack of
cooler air behind the system moving through on the weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 755 AM EDT Wed May 25 2016

VFR weather is expected to continue today into this evening. Any
cumulus that develops this afternoon should have bases above 5000
ft. Isolated tstms cannot be ruled out but the primary risk is
north of the srn lwr mi terminals. Did keep a mention of CBs in
the GRR TAF with expected convergence along the lake breeze front
otherwise kept the mention of afternoon CBs out of the other TAFS.

A more concentrated area of showers and thunderstorms is expected
to approach from the southwest after 00Z tonight... with coverage
increasing toward 06Z. While convection is more likely tonight,
conditions will probably still stay predominately vfr. However
some fog/stratus could develop toward 12z Thursday as a warm front
approaches and dew points rise.

&&

.MARINE...
Issued at 330 AM EDT Wed May 25 2016

Areas of dense fog will become a concern over Lk MI tonight and
beyond as dew points above 60 arrive.


&&

.HYDROLOGY...
Issued at 152 PM EDT Tue May 24 2016

Periodic showers and thunderstorms will move through the region
especially Wednesday night, Friday and Saturday. However, overall
rainfall amounts will likely be variable across the area. Some
locations may pick up well over an inch of rain through the
weekend, while other places much less. A good portion of the more
widespread rainfall could occur Wednesday night as a warm front
lifts through. Thursday and beyond will feature some diurnally
driven convection that could produce locally heavy rainfall...but
basin average rainfall is not expected to be excessive. Smaller
creeks and rivers could be susceptible to quick rises given this
setup. Main stem river flooding does not look likely.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.
&&

$$

SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...NJJ
AVIATION...Meade
HYDROLOGY...Hoving
MARINE...Meade




000
FXUS63 KDTX 251105
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
705 AM EDT WED MAY 25 2016

.AVIATION...

VFR in a mix of mid and high clouds during the morning will precede
a cold front settling into the area from northern lower Michigan.
This front is expected to stall between MBS and FNT during early
afternoon and provide a focus for scattered showers and
thunderstorms from about mid afternoon through evening having the
best chance to affect MBS mid to late afternoon. Conditions will
otherwise remain VFR around SE Michigan even within the frontal zone
outside of the scattered heavier showers/storms. MVFR is then
expected to develop as coverage of showers increases and as boundary
layer moisture pools enough for development of fog and/or lower
ceiling through sunrise Thursday.

FOR DTW...VFR will consist of some cirrostratus during the morning
that will thin in favor of scattered high based cumulus during the
afternoon. Showers/storms will remain outside of the DTW/D21
airspace until tonight, and especially after midnight through mid
Thursday morning. At this time, plan to hold off on TSRA mention for
tonight until timing can be refined more precisely.

//DTW Threshold Probabilities...

* Low for ceiling 5000 FT or less tonight.

* Moderate for thunderstorms affecting DTW/D21 air space tonight.

&&

.PREV DISCUSSION...
Issued at 333 AM EDT Wed May 25 2016

DISCUSSION...

Appears in the long range models that the current western conus
trough and eastern conus ridge will hold through the next week or
more. This means the current warm airmass will hold in place with
high temperatures largely in the 80s through the forecast. It also
means the northeast flow regime will persist with a series of
shortwaves ejecting out of the trough up through the Midwest keeping
chances of thunderstorms in the forecast nearly every day. It won`t
be a complete wash out this week though as best chances of
precipitation will be tied to shortwaves with an overall lack of
lower level lifting mechanisms. One other thing to watch for will be
upstream MCS`s and the potential they can hold together into lower
Michigan.

Currently there is a stalled cold front draped across mid Michigan
which was the focus for some showers and thunderstorms on Tuesday
and Tuesday night. A narrow ribbon of enhanced theta e was co-
located along the front providing a boost in moisture to a
relatively dry column, while weak convergence developed at the
surface at the front. A fairly strong mid level short wave has
lifted out of southern California and will pass through MN and into
Ontario this evening. A lobe of vorticity extending southeast from
the developing mid level low will sweep through southern Michigan
this evening, which will change the stalled front into a warm front
that will lift north toward the straits by early Thursday afternoon.
This will present one of the best opportunities for thunderstorms in
the forecast as the nose of a strong theta e surge lifts into the
area behind the warm front. Elevated levels of CAPE around 500-1000
J/Kg, shear increasing to around 30 knots, and favorable mid level
lapse rates and LI`s will also accompany the front. Some storms
could become strong but stability in the lower levels will keep
things more elevated which could reduce gust potential. Coverage
should increase over the western and northern part of the SE MI but
most locations will have at least a high chance of showers.

Another wave is set eject through the flow Friday morning presenting
the next good chance at widespread showers and thunderstorms across
the area. Upstream trough amplification will lead to the resident
ridge getting pulled back to the west which will pull the better
support westward as well. Will have to watch how this all evolves
moving forward as large convective systems in the plains may keep
the lower heights further south and east.

Heading into the weekend the wave train continues but timing any of
these features is difficult at best with this type of active
pattern. It is worth noting that outside of the two more dominate
waves heading into the weekend, the models are all fairly uniform in
presenting more of a diurnal component to the shower activity. Once
we get the higher dew points into the region, a summer like pattern
will ensue with diurnal heating popping a few showers in the
afternoon. With lack of any focusing mechanism coverage will be ill
defined, hence a daily chance pop lingers in the forecast.

MARINE...

A weak cold front will remain the focal point for marine weather in
the short term as it settles into southern Lake Huron and central
lower Michigan today and then returns northward tonight. The wind
will be light within and around the frontal zone leaving the main
impact to be showers and thunderstorms that will become more
numerous tonight. Fog will also become increasingly prevalent as the
warm and humid air pools over the colder open waters of Lake Huron.

The front will move northward into Canada Thursday and leave light
southerly wind over all marine areas that will maintain warm air
Friday into Saturday. Showers and storms remain possible but will be
less organized until possibly later Saturday and Saturday night as
low pressure develops over the upper Midwest. This system will also
help maintain warm conditions and light south wind well into the
holiday weekend.

HYDROLOGY...

Warm air with increasing humidity will pool along a front settling
as far south as the I-69 corridor today. High temperatures returning
to the lower and mid 80s could result in a few thunderstorms along
the front during the afternoon and evening. Showers and storms are
then expected to increase coverage overnight with the help of low
pressure over the Midwest that will pull the front northward
Thursday. Rainfall amounts are expected to vary widely depending on
thunderstorm coverage but should average 0.25 to 0.5 inch for the
Wednesday night-Thursday period with locally higher totals near 1
inch possible in thunderstorms. Warm and humid air will then remain
in place to support shower and thunderstorm potential into the
weekend with less organization until arrival of the next low
pressure system possibly by Saturday into Saturday night.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.

&&

$$

AVIATION.....BT
DISCUSSION...DRK
MARINE.......BT
HYDROLOGY....BT


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.




000
FXUS63 KAPX 251044
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
644 AM EDT WED MAY 25 2016

.SHORT TERM...(Today and tonight)
Issued at 356 AM EDT Wed May 25 2016

High impact weather potential: t-storms returning this afternoon
and especially tonight.

Weak cold front is somewhat difficult to pick out, but appears to
have settled a bit south of TVC/APN. The front will drift south into
central lower MI before stalling this morning. It will return north
tonight, before getting caught and absorbed by a warm front now in
KS/southern MO. Lingering shra activity is moving out across Lake
Huron, giving us a lull in precip for the morning and early
afternoon. There are two possible sources of precip after that:
any chance that deep convection can fire this afternoon, and then
a true surge of warm/moist air arriving tonight.

Today...post-frontal band of fog/stratus has settled into the
straits region and eastern upper mi. Some fog has also formed
ahead of this across far northern lower, thanks to a rain-cooled
and -moistened airmass. Fog south of CVX/Petoskey/Rogers is thin
and will erode quickly this morning...with little to limit strong
late May sunshine. Straits/upper MI cloud cover is thicker and
will be considerably more stubborn (marine influences will help
maintain it). But do expect that cloud deck to break down around
midday.

Meanwhile, despite being in the /cool/ sector, northern lower will
be baking away. There is a touch of cirrus wafting in from the sw
now, and will become more prevalent with time as the day proceeds.
But with plenty of sunshine otherwise and a mild start to the
morning, highs will be somewhat toasty again today. A tendency
toward a light se synoptic wind will keep the Lake Huron
coastline cooler in the 70s (even cooler yet along the immediate
beaches). Same applies for eastern upper. But the rest of northern
lower will reach the lower and perhaps mid 80s again.

Dew points have finally jumped dramatically thanks to the nighttime
SHRA activity. Outside of marine-influenced locales, surface dew
points in the mid 50s will be common. This results in reasonable
instability building this afternoon near/south of M-72. Mlcapes
should approach 1k j/kg by late in the afternoon. Model soundings
do portray a touch of capping trying to arise this afternoon at
about 625mb. Said soundings suggest this cap will not hold, but
worth noting that model soundings generally underforecast capping.
Background se synoptic wind will be weak enough to permit lake
breezes, so suspect we will have the trigger needed to get past
capping aloft.

So, after a dry morning, will advertise a chance of pm t-storms in
southern sections, away from the coastlines. This is largely in
agreement with the going forecast. Shear is unimpressive, with less
than 15kt of wind up thru 700mb, and 0-6km bulk shear around 20kt.
Not much in the way of a svr threat, though if instability ends up
toward the high end of estimates, something brief/marginal is not
completely out of the question.

Tonight...warm front will charge into northern lower MI overnight.
850mb dew points will increase into the lower teens, and surface dew
points behind the warm front will push 60f overnight. This airmass
enters the region on 25-35kt 850mb winds. Outside of lingering
daytime convection, the mid-evening hours look largely dry. But that
lingering convection will stay healthier than one would otherwise
expect as better 850mb theta-e advection kicks in. More widespread
precip is likely late evening and overnight as the surface and 850mb
warm fronts race in. Not quite ready to kick pops to categorical
(this is convection we/re dealing with), but 70 pops at least will
suffice for overnight. Qpf totals of 0.25-0.50 look most likely. Min
temps lower 50s to lower 60s.

.LONG TERM...(Thursday through Tuesday)
Issued at 356 AM EDT Wed May 25 2016

...Warm and muggy with showers and storms into the holiday weekend...

The pattern over the next few days still looks unsettled at times
with climbing humidity levels along with decent chances for rounds
of showers and thunderstorms. This will be the result of numerous
pieces of energy ejecting out of a broad long wave trough which will
continue to stretch from the Pacific Northwest into the northern
Plains through early next week. There still could be some strong to
severe storms across northern Michigan Thursday as a wing of forcing
sweeps across the region. The best shot for any stronger storms to
form looks like it`s over north central and northeast lower Michigan
as models generate 0-1 km ML Cape of between 1500 and 2500 j/kg and
little convective inhibition. Wind fields are decent Thursday
afternoon with 0-6 km bulk shear of 35 to 40 knots (strongest north)
but generally under 30 knots for the remainder of the period as the
main jet stream remains focused north and west of the region.
Moisture is on the increase with PW/s generally increasing to
between 1.25 and 1.50 inches so we could get into some heavy
rainers. A more widespread area of showers with embedded
thunderstorms is likely late Friday into Saturday as energy/moisture
advect into the region. Besides the system driven showers, expect
diurnally induced showers and storms to fire with a limited
potential for isolated severe storms over the coming days.
Temperatures through the period are still expected to run a few
degrees above normal for the end of May.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 644 AM EDT Wed May 25 2016

IFR/LIFR early this morning at PLN. MVFR returns to MBL/TVC/APN
late tonight.

Stratus/fog deck has settled in over PLN, behind a cold front
moving into central lower MI. Clouds/fog will burn off by late
morning. VFR elsewhere thru this evening. SHRA/TSRA move in from
the sw tonight, mainly after midnight. MVFR cigs/vsbys expected
at MBL/TVC/PLN late.

Light southeast surface winds.

&&

.MARINE...
Issued at 356 AM EDT Wed May 25 2016

Somewhat more humid airmass is already in place thanks to last
nights rain. That is contributing to fog, especially north of Gd
Trav Bay and Rogers City, including around eastern upper MI. An
even more humid airmass invades late tonight as a warm front
moves in. Marine fog/stratus will be an occasional issue thru the
forecast. Winds/waves will generally be light...from the se
today...becoming s to sw tonight.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JZ
LONG TERM...Sullivan
AVIATION...JZ
MARINE...JZ




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