Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/10/20

AREA FORECAST DISCUSSION

National Weather Service Albany NY

 1010 PM EDT Tue Jun 9 2020

.SYNOPSIS...
High pressure will build in from New Brunswick and Nova
Scotia tonight, as a frontal boundary settles south of the region.
The front will move north and east of the region, as a warm front
tomorrow bringing some showers and thunderstorms.  A warmer and more
humid air mass will be over the region Wednesday night into
Thursday, as a cold front will bring more showers and thunderstorms
with locally heavy rainfall.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Wind shift boundary has drifted south through KGFL, K5B2 and
KVSF, and likely KPSF. The wind shift boundary will continue to
drift south and west and winds will become northeast to southeast
light and steady at less than 6 Kt, occasionally calm tonight.
Only some mid and high clouds from time to time through the
night as low level dewpoints hold steady or slowly rise. Just
some minor adjustments to sky cover, timing of weak wind shift
and temperatures through the night. Previous AFD has a few more
details and is below...

Some mid and high clouds will be around tonight, and it will be
variable cloudy. The winds will go briefly light to calm
allowing some radiational cooling, but shortly before or after
midnight. However, the low-level east to southeast flow will
increase. Some stratus may form and move into locations south
and east of Albany shortly before sunrise. Depending on the
winds and degree of cloud cover. Lows will be in the upper 50s
to lower 60s from the Capital Region and Mohawk Valley south and
east, as lower to upper 50s are possible to the north and east.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Tomorrow, the guidance has trended cooler with temperatures
tomorrow, as initially clouds and a less humid air mass will be
over the region. The frontal boundary will lift northward as a
warm front in the morning. The low-level convergence increases
and some showers and initially isolated/scattered thunderstorms
will break out in the late morning/early pm north and west of
the Capital Region.

A limiting factor will be the amount of instability available.
The greatest mean MUCAPES on the latest 12Z HREFS are west of
the Hudson River Valley in the 750-1250 J/kg range. The 0-6 km
shear bulk shear is 30-40 kts. Less instability is available
from the Hudson River Valley east. The gradient in SBCAPE on
the NAM/GFS sets up along the western periphery of the forecast
area along the western Mohawk Valley/western Adirondacks/eastern
Catskills with 1000-1500 J/kg with slightly higher amounts as
dewpts rise into the 60s. We leaned close to the 3-km NAMnest
and HRRR with some convection forming west and northwest of the
Capital Region, especially in the afternoon. The mid-level
lapse rates look weak at less than 6C/km. PWATS will be on the
rise into the 1.5-2.0" range late in the day. A few multicells
or an isolated supercell may be possible, as we break into the
warm sector in the "Slight Risk" region in SPC Day 2 outlook.
Damaging winds and large hail would be in the main threat for
the southern Adirondacks, western Mohawk Valley, Schoharie
Valley and eastern Catskills. The 0-3 km SRH values are high
initially in the 200-350 (m/s)2 range due to the strong veering
in the low-levels. A isolated tornado may be possible in the
western Mohawk Valley into the southern Adirondacks. We added
small hail, gusty winds and locally heavy rainfall for areas in
the Slight Risk area. We were not confident further east.

Max temps were kept in the lower to mid 80s range in the valley,
and upper 60s to 70s over the higher terrain and across the
northern Berkshires into southern VT.

Wednesday night...The convection should begin to diminish with
the loss of the diurnal heating and less instability. Any
severe threat should decrease before 9 pm. A prefrontal trough
ahead of the cold front may keep the scattered showers going in
bands. The air mass becomes very humid with sfc dewpts rising
into the 60s to close to 70F. The PWATS will be in the 1.7-2.0+"
range. These values are +2 to +4 STDEVs above normal based on
the latest 12Z GEFS. We kept PoPs in the likely and high chance
range. We also kept a slight chance of thunderstorms with 12Z
mean MUCAPEs on the latest HREFS in the 250-500 J/kg range. It
will be muggy with lows in the lower to mid 60s over the higher
terrain, and upper 60s to lower 70s in the valleys.

Thursday...The latest Ensemble guidance and some of the CAMS
show the front make steady progress across the forecast area
during the late morning into the afternoon. The low-level
convergence with the front will focus bands of showers and some
thunderstorms. Any strong thunderstorms would be over the
southeast extreme of the forecast area. Sfc heating may be
limited due to lots of clouds. The 12Z GFS continues to be
faster with the cold frontal passage compared to the latest
NAM/ECMWF. We will continue to monitor for locally heavy
rainfall. Highs will be mainly in the 70s to lower 80s. Cooler
and drier air may get into the southern Adirondacks quickest
with highs only in the upper 60s to lower 70s.

Thu night...Showers over western New England will end early. Cold
advection occurs in the wake of the front. The skies may become
mostly clear to partly cloud.  It will become less humid with
dewpoints falling into the 50s and even mid and upper 40s over
the southern Adirondacks. Lows temps will be mainly in the 50s,
though a few lower 60s are possible in the Capital District, mid
Hudson Valley and NW CT.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
There remains considerable uncertainty regarding the long term
period and how the upper level patterns evolves during the weekend
into early next week.  It appears that there will be an upper level
trough approaching the Northeast and it may become cutoff.  However,
it is unclear when/where the cutoff occurs and exactly how it
tracks.  The latest 12z ECMWF has the system cutting off and
remaining further west than the 12z GFS.  The 12z GGEM is more
similar to the GFS, although slightly further west.

As a result, there will be a threat for some showers during the long
term period, especially for the Monday through Wednesday time
period.  The coverage and amounts of precipitation will depend on
how the upper level pattern evolves, so this is still very unclear.
For now, have gone with slight to low chance POPs through much of
the extended period, with the highest POPs during the upcoming week.
 Best chance will likely be during the diurnally favored afternoon
and evening hours.  For now, will not include any thunder, but this
is something that could be included in later forecasts once the
pattern becomes more clear.  Will keep temps fairly close to
seasonal normals, with valley highs in the mid 70s to low 80s.
Overnight lows will generally be in the 50s.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Weak wind shift boundary is drifting south through the night but
just some intervals of mid level clouds tonight. Intervals of
clouds through Wednesday with just some scattered showers and
isolated thunderstorms Wednesday afternoon.

Southwest to northwest winds at less than 10 Kt will shift to
northeast to southeast at less than 6 Kt this evening but
variable at KPOU. The variable to light northeast to southeast
winds will continue through the night. Winds become relatively
uniform southeast everywhere by about 14Z at 10 Kt or less but
could gust to around 15 Kt at KALB Wednesday afternoon.

Outlook...

Wednesday Night: High Operational Impact. Breezy. Likely SHRA...TSRA.
Thursday: High Operational Impact. Breezy. Likely SHRA...TSRA.
Thursday Night: Low Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Low Operational Impact. Slight Chance of SHRA.

&&

.FIRE WEATHER...
High pressure will build in from New Brunswick and Nova
Scotia tonight, as a frontal boundary settles south of the region.
The front will move north and east of the region, as a warm front
tomorrow bringing some showers and thunderstorms.  A warmer and more
humid air mass will be over the region Wednesday night into
Thursday, as a cold front will bring more showers and
thunderstorms.

RH values will increase to 809 to 100 percent Wednesday
morning, and lower to 50 to 70 percent during the afternoon.
Relative humidity values will rise to 90 to 100 percent Thursday
morning.

The winds will increase from the northeast to southeast at less
than 10 mph tonight. They will be from the south to southeast at
5 to 15 mph tomorrow and will be southerly at 5 to 15 mph
Wednesday night.

&&

.HYDROLOGY...
No widespread problems are expected on the main stem rivers the
next several days in the ALY Hydro Service Area /HSA/.

Mainly dry weather will continue this afternoon into Wednesday
morning for the ALY HSA. A warm front will increase the threat
of showers and thunderstorms Wednesday afternoon into Wednesday
night. A cold front will bring additional showers and
thunderstorms on Thursday.

Total rainfall may range from a third of an inch to three
quarters of an inch. Some locally higher amounts in excess of
an inch are possible, especially from any convection, as PWAT
values rise into the 1.5-2.0" range, which are 2 to 4 standard
deviations above normal. Gridded FFG values are high at the
moment due to dry soil antecedent conditions over much of the
HSA. Some rainfall rates may be briefly intense with any
thunderstorms Wednesday into Thursday.

A brief period of dry weather is possible Thursday night into
early Friday in the wake of a cold front. A closed or cutoff
low may increase the threat for showers again on the weekend
into early next week, however, confidence is rather low on
weather impacts at this time due to a lot of uncertainty with
the formation and location of the cut-off and its associated
precipitation.

For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$
SYNOPSIS...Wasula
NEAR TERM...NAS/Wasula
SHORT TERM...Wasula
LONG TERM...Frugis
AVIATION...NAS
FIRE WEATHER...Wasula
HYDROLOGY...BGM/Wasula



Area Forecast Discussion

National Weather Service Bismarck ND

 842 PM CDT Tue Jun 9 2020

.UPDATE...
Issued at 840 PM CDT Tue Jun 9 2020

The forecast generally looks to be in good shape. Thunder has all
but ended over the area and showers will continue to slowly
diminish as the sun sets. For this update, just tweaked cloud
cover based using the latest iteration of the NBM which seems to
be doing very well with the current cloud trends.

UPDATE Issued at 607 PM CDT Tue Jun 9 2020

Widespread showers with a few weak thunderstorms have developed
as expected across much of western North Dakota late this
afternoon as we remain in cyclonic flow aloft. An area of
steadier rain associated with a vacating shortwave continues to
lift northeast through the James River Valley. For this update,
tweaked precipitation chances to better reflect the latest radar
observations and trends along with a time lagged RAP solution that
seems to have a good handle on what`s going on. Otherwise, just
blended in the latest observations to the forecast.

&&

.SHORT TERM...(This evening through Wednesday)
Issued at 246 PM CDT Tue Jun 9 2020

Showers east and scattered showers and possibly isolated
thunderstorms are in the forecast for this evening. Showers and
possibly isolated thunderstorms are in the forecast tomorrow as
well for the northern and central portions of the state. Severe
weather is not expected.

The synoptic picture this afternoon centered around broad cyclonic
flow over the central CONUS with two shortwave troughs ejecting
over the Rockies and High Plains as well as mid-level circulation
from Tropical Depression Cristobal becomes embedded in the mean
cyclonic flow over Iowa/Illinois. The two western shortwaves, one
over the Montana/North Dakota border with the southern over
western Kansas will continue to eject embedded impulses over the
eastern Dakotas this evening with widespread showers expected
until both low pressure centers move east after midnight. Showers
and possibly thunderstorms are expected to develop this
afternoon/evening in western North Dakota as cold air aloft
accompanies the mid-level trough. With just weak instability,
severe weather is not expected.

Tonight and tomorrow, the mid-level circulation remains in place
over North Dakota and southern Saskatchewan/Manitoba as a
secondary shortwave arrives. With steep mid-level lapse rates and
broad cyclonic flow aloft, diurnally driven showers and possibly
thunderstorms should develop across the north and much of the
central portions of the state tomorrow afternoon and evening.
MUCAPE should be low enough to preclude strong thunderstorms.

Temperatures tonight and tomorrow will remain on the relatively
cooler side with lows in the 40s tonight and highs in the low 70s
on Wednesday. Persistent mid-level impulses overnight should keep
enough of a pressure gradient to prevent overall temperatures
from dropping below 40. With the northwest flow pattern and steep
low level lapse rates, we bumped up winds tomorrow to the
sustained 15 to near 25 mph range.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 246 PM CDT Tue Jun 9 2020

A dry and warming trend is in the forecast through the rest of the
week before convection chances return Saturday night.

Through the latter half of the week, northwest flow over the
Northern Plains continues as a ridge begins to build over the
Rockies and a deep trough develops over the southwest coast.
Guidance shows low-mid level warm air advection beginning on
Thursday, which should allow for a gradual warming and dry trend
as the western ridge moves over the Northern Plains through
Saturday. Highs in the upper 70s and 80s are expected by
Friday/Saturday.

Deterministic and ensemble guidance is in relatively good
agreement in the ridge moving off to the east over the weekend
with more active flow taking over, allowing for thunderstorm
chances to possibly return Saturday night. With the deep trough
developing to our west on Saturday, a strong pressure gradient
should develop southerly winds within the associated lee surface
cyclone. NAEFS guidance shows 850mb winds within the 90th
climatological percentile Saturday afternoon with 850mb winds near
or around 40 kts forecast. We`re far enough out in the forecast
period to hold back from more specific messaging in products like
the HWO, but with this kind of setup wind advisory criteria winds
are not out of the question.

Looking into early next week, CIPS ensemble guidance shows a mean
troughing pattern over the Pacific Northwest with possibly active
flow over the Northern Plains. Climatologically this would
indicate the possibility for severe storm chances to continue
through next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 607 PM CDT Tue Jun 9 2020

Scattered showers will continue through the early evening hours
before diminishing overnight. These pop up type showers will be
very hit and miss and will not last long, so will only keep the
mention of VCSH in the forecast. While there is a chance for an
isolated lightning strike or two, any embedded thunderstorms will
be very few and far between. Clearing will then take place
overnight and a breezy day will setup across east Wednesday
afternoon. VFR conditions are expected through the period.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...ZH
SHORT TERM...AE
LONG TERM...AE
AVIATION...ZH



Area Forecast Discussion

National Weather Service North Platte NE

 637 PM CDT Tue Jun 9 2020

.SHORT TERM...(This evening through Wednesday night)
Issued at 320 PM CDT Tue Jun 9 2020

The high wind warning can be cancelled west of Lincoln county.
H850mb winds have subsided to 50 kts or less near and west of
Ogallala according to the RAP model. Elsewhere, the warning will
continue until 9 pm as planned. The NAM and RAP soundings show
mixing heights falling off very quickly with the loss of daytime
heating. The warning might need an extension in time and an
expansion north into ncntl Nebraska if the HRRR model gusts
verify. The rain should limit mixing heights and lessen the gust
potential. There is evidence of this happening Ogallala and
Imperial where gusts have fallen off.

Pacific high pressure across the Cntl Rockies will build east
overnight and skies should clear from west to east by Wednesday
morning. The guidance blend plus bias correction was the basis for
lows in the 40s overnight. The high pressure will present clear
skies Wednesday and Wednesday night. The blend suggested highs in the
70s and lows in the 40s to lower 50s.

.LONG TERM...(Thursday through Tuesday)
Issued at 320 PM CDT Tue Jun 9 2020

Northwest flow aloft will continue aloft through Friday and then
transition to southwest as another upper low drops into the
Pacific northwest. A trof of low heights will extend south through
the Desert Southwest and this should flush warm air across the
Rockies. Temperatures at h850mb will rise back to around 25C and
13C at h700mb. Temperatures around 90F are in place Sunday through
Tuesday.

Diurnal heating might be sufficient for isolated thunderstorm
development across wrn Nebraska over the weekend. These storms would
likely originate off the Laramie Range as the upper level forcing is
very weak.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 636 PM CDT Tue Jun 9 2020

An upper level low pressure system will move east with showers
ending from west to east soon after 06Z. Strong northwest winds
have begun to subside, but gusts above 30KT will remain possible
this evening. VFR conditions are also expected, with skies
becoming SCT250 around 06Z. Mainly SKC on Wednesday, with winds
near 31015G22KT during the day.

&&

.HYDROLOGY...
Issued at 320 PM CDT Tue Jun 9 2020

The MBRFC ran their forecast model for the Elkhorn river this
morning and concluded the river will rise to around 10.0 feet by
Saturday. This is moderate flood stage. The 4 to 6 inch stripe of
rainfall extending from near North Platte to Stapleton, Brewster
and Stewart has produced rises on the river gages across the
Sandhills but just the Elkhorn river appears to be flooding.

The Flood Watch will continue across ncntl Nebraska. One round of
elevated thunderstorms is underway and producing a quick 1/4 inch of
rain with the stronger thunderstorms. The HRRR suggests a second
burst of scattered thunderstorms forming further west late this
afternoon affecting Custer county and areas north. Satellite
suggests ncntl Nebraska will remain under an h700mb warm air
advection zone this evening. The HRRR suggests another 1/2 to
locally 3/4 of an inch of rainfall this afternoon and early this
evening.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 9 PM CDT /8 PM MDT/ this evening for
NEZ036>038-058-059-069>071.

Flood Watch until 7 PM CDT this evening for NEZ006>010-026>028-
038.

&&

$$

SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Roberg
HYDROLOGY...CDC



Area Forecast Discussion...Updated Aviation

National Weather Service Saint Louis MO

 557 PM CDT Tue Jun 9 2020

.SHORT TERM...  (Through Late Wednesday Night)
Issued at 234 PM CDT Tue Jun 9 2020

Widespread rainfall associated with the remnants of Cristobal has
largely moved out of the far northern sections of the forecast
area with the surface low now currently near Burlington, IA.
Behind this system, the focus is on the possibility of convective
initiation along a warm front extending eastward from a separate
surface low located over east-central Kansas. Believe the 1500 UTC
experimental HRRR has the best handle on how things are likely to
evolve through this evening. It suggests isolated-scattered
showers and thunderstorms developing very late this afternoon in
vicinity of the warm front moving north through the late evening
before exiting the CWA. The combination of capping and mid/upper
level subsidence in the wake of Cristobal makes initiation at all
not a sure thing, but the best chances likely will be across
portions of northeast Missouri by mid evening where low-level
convergence and some cooling aloft occurs downstream of the
approaching trough. The atmosphere however is certainly supportive
of strong to severe thunderstorms given strong instability and
deep-layer shear, including supercells. Damaging winds and
isolated tornadoes remain the main threats with any organized
convection that does develop, mainly between 7-10PM this evening
for portions of northeast Missouri.

After the warm front and any associated convection moves north of
the CWA before midnight, mostly dry weather is forecast for the
remainder of the night. The exception could be some isolated
showers or storms along the eastward moving dryline, mainly
along/east of the Mississippi River. Isolated-scattered showers
are possible once again on Wednesday along/ahead of the trailing
cold front attendant form a deepening surface low across the
Upper Midwest. The main story however for Wednesday will be the
much cooler and less humid conditions. High temperatures will
likely struggle to hit 70 degrees west of the Mississippi River
with lower stratus and strong low-level cold air advection. For
areas further east, mid to upper 70s are favored. A broken to
overcast cloud deck and gusty west/southwest winds will likely
make it feel even chillier across the bi-state area, more
analogous to early May than mid June.

Decreasing cloudiness along with relaxing west/northwest winds
are likely Wednesday night as the pressure gradient relaxes south
of the exiting surface low. A seasonably cool and dry night
should be in store with lows in the 50s areawide.


Gosselin

.LONG TERM...  (Thursday through Next Tuesday)
Issued at 234 PM CDT Tue Jun 9 2020

Largely dry weather with near to slightly below normal temperatures
is favored for the remainder of the 7-day forecast. The GEFS/EPS
show a strong shortwave trough transversing the Great Lakes late
Friday into Saturday, which slowly propagates eastward heading into
early next week. This feature is expected to send a backdoor cold
front through most of the CWA early this weekend, but moisture
return and forcing for ascent is nearly non-existent, so dry weather
is expected to continue. Temperatures ahead of the front should be
right near normal Thursday/Friday with highs in the low to mid 80s.
Behind the front, temperatures should cool about 5 degrees. For this
weekend, highs are likely to be in the upper 70s to low 80s with
lows in the 50s once again. The dry weather is likely to continue
through next Tuesday as ensemble guidance shows the mid/upper level
ridge axis edging eastward toward the mid-Mississippi Valley. The
main change will be a likely moderation in temperatures as
850-hPa temperatures climb toward +20C. Highs on Tuesday are
likely to climb back above normal as readings are expected to
reach the mid to upper 80s.


Gosselin

&&

.AVIATION...  (For the 00z TAFs through 00z Wednesday Evening)
Issued at 537 PM CDT Tue Jun 9 2020

The MVFR cloudiness should scatter out early this evening in UIN
as the remnants of Cristobal move further northeast of this
region. Widely scattered showers and storms are expected this
evening as a warm front lifts northeastward through the area early
this evening, while a dry line extending from a surface low over
northeastern KS southeast through southwestern MO moves eastward
through the taf sites later this evening. The diurnal cumulus
field should dissipate later this evening due to the loss of
daytime heating, and as drier air filters eastward into the
region. MVFR cloudiness will advect into the taf sites Wednesday
morning along a cold front moving eastward through our area. Gusty
southwest winds will weaken this evening, then veer around to a
west-northwest direction Wednesday afternoon as they strengthen
after fropa.

SPECIFICS FOR KSTL:  Widely scattered showers and storms are
expected this evening as a warm front lifts northeastward through
the area early this evening, while a dry line extending from a
surface low over northeastern KS southeast through southwestern MO
moves eastward through STL late this evening. The diurnal cumulus
field should dissipate later this evening due to the loss of
daytime heating, and as drier air filters eastward into the
region. MVFR cloudiness will advect into STL by late Wednesday
morning along a cold front moving eastward through our area. Gusty
southwest winds will weaken this evening, then veer around to a
west-northwest direction Wednesday afternoon as they strengthen
after fropa.

GKS

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...Wind Advisory until 7 PM CDT this evening for Bond IL-Clinton IL-
     Fayette IL-Marion IL-Montgomery IL-Washington IL.

&&

$$

WFO LSX



Area Forecast Discussion

National Weather Service Marquette MI

 802 PM EDT Tue Jun 9 2020

.SHORT TERM...(This evening through Wednesday)
Issued at 442 PM EDT TUE JUN 9 2020

WV imagery and RAP analysis indicated a mid/upper level ridge from
the southeast CONUS into the Great Lakes and troughing through the
western Plains. The circulation center with the remnants of TS
Cristobal was located near the southeast corner of IA with a broad
shield of moderate to heavy rain from eastern IA and nrn IL into
se MN. Another strong upstream shrtwv or mid level low was located
over wrn KS. Otherwise, even with increasing high clouds, temps have
climbed into the upper 80s over much of Upper Michigan, except near
the Great Lakes with lake breezes have kept readings in the upper
60s to 70s.

Tonight, expect the Cristobal low to continue lifting northward with
a path through central Upper Michigan by 12z/Wed bringing a period
of heavy rain to most of the area. Expect the heaviest band of rain
on the west side of the low track in the area of strongest
isentropic lift. Tropical moisture with PWAT values above 2.0 inches
will favor very efficient rain production during the brief period
stronger dynamics. The models have trended slightly eastward with
the axis of highest QPF compared to earlier runs with amounts that are
also not quite as high. The higher amounts in the 1-2 inch range are
still expected through the west. However, there is still some
uncertainty with how well the models will depict the higher QPF
potential and where the heaviest amounts will occur as some
locally higher amounts to 3 inches may be possible in a narrow
area. A Flash Flood Watch was posted over the west where the
heaviest rain is expected. Otherwise, QPF in the 0.75 to 1.25
inch range is expected over much of the rest of the area.

Wednesday, a period of strong southerly winds is also expected late
tonight through Wed morning as the low moves through given the large
pres rise/fall couplet ahead of the low. Although stability may be
less than favorable for deeper mixing, 3 hour pres falls of 10 mb
ahead of rises to 6 mb will support a vigorous isallobaric component
so that gusts into the 40-50 mph range will be likely, mainly over
the east from Schoolcraft into Luce counties. The strong winds
will also likely cause some lakeshore flooding on the north end of
the bay of Green Bay and along Lake Michigan to the east. After
the low lifts north of the area, expect a lull in the pcpn with
gusty west winds. Rain with the Plains shrtwv lifting toward the
area will increase from the southwest in the mid to late
afternoon.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 500 PM EDT TUE JUN 9 2020

An amplified pattern is expected over N America thru at least early
next week. Trof currently shifting toward the Plains will move
across the western Great Lakes late Wed thru Fri. Over the weekend,
pattern will again become quite amplified with a fairly deep trof
moving into the western U.S. forcing an amplified central N America
ridge while the Great Lakes trof shifts toward the eastern U.S.
Pattern will then begin to deamplify next week, but upstream ridge
may end up settling over the Upper Great Lakes for at least a couple
of days before shortwaves moving across Canada begin working to
suppress it. For Upper MI, these changes in the large scale pattern
will result in the current well above normal temps (hot conditions
over western Upper MI) trending much cooler, probably well blo
normal for at least one day, during the last half of this week as
the trof to the w moves across the Great Lakes region and toward the
eastern U.S. Warmth will then return early next week as the upstream
ridge moves to the Great Lakes. As for pcpn, there will be 2 main
pcpn events over the next 7 days. The first occurs tonight into
early Wed morning as TD Cristobal and its associated tropical
moisture race n across the area, resulting in a quick mdt to hvy
rainfall for the fcst area. Shortwave in the base of the approaching
mid-level trof will then swing negative tilt thru the Upper Lakes,
bringing another round of mdt to potentially locally hvy rainfall
across the fcst area later Wed aftn/night. Then, under the cooler
conditions and cyclonic flow, sct -shra may occur Thu, possibly
lingering into Fri. The weekend will be dry with Canadian sfc high
pres ridging s into the Great Lakes downstream of the amplified
central N America mid-level ridge. There may be a risk of shra/tsra
at some point early next week if the Great Lakes ridge begins to
deamplify, allowing shortwaves to move closer to the northern Great
Lakes as the westerlies settle s toward the area. Some recent trends
in longer range guidance suggest this deamplification may be
delayed, allowing dry weather to continue thru early next week.

Beginning Wed night...attention will be on shortwave currently in
the base of the approaching mid-level trof as it swings negative
tilt into the Great Lakes. Strong deep layer forcing and upper
diffluence are noted with this feature as it moves into the northern
Great Lakes. ECMWF has been most consistent on this feature
generating another area of mdt to potentially hvy rainfall across
the fcst area, but it has also shown a gradual eastward trend over
the last several runs. 12z run points toward central and eastern
Upper MI to be impacted by the heavier rainfall. Other models are
coming inline with this idea, though the cams tend to favor central
Upper MI for heaviest pcpn. GFS is centered more in eastern Upper
MI. In any event, with the heaviest rainfall tonight over western
Upper MI, it will be beneficial to have the heaviest rainfall with
this next round of shra occurring e of that area. Fcst will reflect
highest pops/qpf over the central and eastern fcst area with pcpn
diminishing and mostly ending from w to e overnight. Expect 0.5 to 1
inch of pcpn, but potential is there for locally 1.5-2 inches. Winds
should become breezy under caa regime and fairly tight pres
gradient.

With the mid-level trof over the area on Thu, models show a
shortwave tracking se into the northern Great Lakes. Should see
isold to sct -shra activity with this feature, with greater coverage
in the aftn and across the s half of Upper MI as daytime heating
adds a little instability. NAM was discounted as it was an outlier
showing a cold rain developing across the northern and eastern fcst
area due to a much sharper shortwave trof swinging across the
northern Great Lakes. Will likely become a windy day as 40+kt of
wind will be able to be tapped as mixed layer builds. Winds should
be strongest over the Keweenaw under favorable wnw wind direction.
Wind advy will probably be needed there, potentially high end advy.

Cool, Canadian sfc high pres will begin to build sse into the Upper
Great Lakes on Fri. The high will then be firmly in control for the
weekend. Not out of the question that there could be a few sprinkles
or isold -shra on Fri as fcst area will still be within the western
part of the mid-level trof. Fri will be the coolest day as 850mb
temps will be down around 0C. Will be especially cool along Lake
Superior, especially e of Marquette where lakeside locations will
not get out of the 40s. In the interior, highs will range up thru
the 50s and lower 60s. The weekend will be dry with temps
moderating, back close to normal for Sun. There may be a frost
risk in the interior Fri night and/or Sat night.

Warming will continue Mon/Tue, and at this point, there is no solid
signal for any pcpn.
&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 800 PM EDT TUE JUN 9 2020

VFR conditions are expected to give way to MVFR and IFR conditions
tonight as the remnants of TS Cristobal will move into Upper
Michigan, bringing heavy rain and gusty winds. However, with the low
passing through central Upper Michigan, confidence in the wind
direction and speed is lower as the low moves through, especially at
KSAW, where LLWS is expected overnight. LLWS is also expected at
KIWD and KCMX, though it should not last as long at these TAF sites.
The IFR conditions will improve Wed morning as the low moves away
and westerly winds increase. KCMX should have the highest gusts Wed.
However, depending on how fast the low behind Cristobal moves into
the area, conditions could worsen yet again at the end of the TAF
period.
&&

.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 536 PM EDT TUE JUN 9 2020

Challenging forecast coming up over the next couple of days. Remnant
low pres from what was once tropical storm Cristobal will quickly
lift nne, passing near Marquette Wed morning around 12z and then
exiting nne of Lake Superior by early aftn. Wind fcst is complicated
by a very stable temp profile over Lake Superior which will limit
mix down of much stronger winds not far above the lake sfc. On the
other hand, tight pres gradient and notable pres rise/fall couplet
associated with the quick moving system supports enhanced winds.
Strongest winds will mostly occur along and e of the low pres track,
and in particular at high obs platforms. For now, expect e to se
gales of 35-40kt to develop over eastern Lake Superior overnight. As
the low moves out across Lake Superior Wed morning, strong pres
rise/fall couplet will be aligned to favor a brief period of
potentially stronger winds over far eastern Lake Superior. Not out
of the question that gusts could exceed 45kt for a couple of hrs. On
the s side of the exiting low, a period of westerly gales of 35-40kt
is possible. Winds will settle back to 20-30kt during the aftn. Over
the western part of Lake Superior, winds will generally be under
25kt tonight/Wed.

As a secondary low pres lifts ne of the Great Lakes Wed night,
colder air and a tight pres gradient should support 35-40kt wnw
gales developing over the e half of Lake Superior late Wed night
into Thu morning. Winds will then diminish, falling blo 20kt for
Fri, as high pres begins to ridge sse into the Upper Great Lakes.
Light winds mostly under 15kt should prevail over the weekend.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Lakeshore Flood Advisory from 5 AM to 2 PM EDT Wednesday for
     MIZ013-014.

  Wind Advisory from 4 AM to 11 AM EDT Wednesday for MIZ007-014-
     085.

  Flash Flood Watch through Wednesday morning for MIZ002-009-084.

Lake Superior...
  Gale Warning from 2 AM to 2 PM EDT Wednesday for LSZ251-266-267.

Lake Michigan...
  Gale Warning from midnight tonight to 10 AM EDT Wednesday for
     LMZ221-248-250.

&&

$$

SHORT TERM...JLB
LONG TERM...Rolfson
AVIATION...TAP
MARINE...Rolfson