996
FXUS63 KAPX 011452
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1052 AM EDT Mon Jul 1 2024

.KEY MESSAGES...

- Rain spreads across northern Michigan Tuesday afternoon...
tapering off Wednesday morning with heavy rainfall possible (though
flood issues unlikely).

- Fourth of July holiday continues to look OK with precipitation
chances impinging from the west and south.

- More rain arrives Friday...probably lingers into Saturday

&&

.UPDATE...
Issued at 1049 AM EDT Mon Jul 1 2024

Clear skies across northern Michigan as high pressure remains in
control. High pressure begins to shift to the east tonight, with
increasing clouds and winds shifting to the south. Generally
quiet conditions and seasonable temperatures during this time.
Moisture will increase with showery activity likely Tuesday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 336 AM EDT Mon Jul 1 2024

Pattern/synopsis: Cool high pressure centered between TVC and
GRB. The high will be overhead today, then head east tonight.
Aloft, troffing early this morning will be replaced by 500mb
ridging tonight.

Forecast: Quiet in this short term period. Deeply dry air and
building heights aloft will lead to little cloud cover today. As
we head toward this evening, some high clouds could reach parts
of nw lower MI. As return flow increases here and especially to
our w tonight, convection is expected to make eastward progress
across the upper MS Valley and into the western lakes. This
eastward progress looks to be slower than earlier forecast.
Though clouds will increase here tonight, precip chances will
remain to our west.

Temps will be warmer both today and tonight. Max temps today
mid-upper 70s for most. Lows tonight in the 50s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 336 AM EDT Mon Jul 1 2024

Pattern Forecast: Split North American pattern with a wavy southern
branch dominating the CONUS.  Short wave ridge axis crossing
Michigan today/tonight will be over Quebec/lower Great Lakes Tuesday
ahead of a short wave trough moving through the Prairie provinces
and the Plains states.  Height falls associated with this feature
will arrive over the region Tuesday night/Wednesday...with the main
jet axis lying west-east over the upper Lakes Thursday along
confluence axis between northern and southern streams which are
forecast to meet up in the vicinity of Lake Superior.  Another short
wave trough is forecast to roll across the Midwest/Great Lakes
Friday and Saturday.

1027mb high pressure centered over the upper Midwest/Great Lakes
early this morning...will cross Michigan today and end up over New
England/mid Atlantic Tuesday morning with southerly return flow into
the upper Lakes.  Short wave trough crossing the upper Midwest/Great
Lakes will push a cold front across Michigan Wednesday.  What
remains of this boundary will likely get hung up across the Ohio
Valley Thursday...then lift north across Lower Michigan as a warm
front Friday.  Perhaps some cooler west/northwest boundary layer
flow in the low`s wake for Saturday.

Primary Forecast Concerns:

Rain spreads across northern Michigan Tuesday afternoon...tapering
off Wednesday morning with heavy rainfall possible (though flood
issues unlikely):  Clouds will thicken and lower from west to east
Tuesday morning as deeper moisture spreads into the upper Great
Lakes from the southwest.  Low levels are dry to start however with
a continued anticyclonic trajectory around the high over New
England.  So will probably start out as a bit of a virga storm...
and thus have trended precipitation timing slower with minimal PoPs
east of a PZQ-HTL line until Tuesday evening.  Moisture transport
into northern Michigan will be maximized Tuesday night into
Wednesday morning...precipitable water approaching 2 inches and
indications of a deep warm cloud layer (~4km) promoting warm rain
collision-coalescence processes. Potential is there for a stripe of
1.00+ inch QPF north of a CAD-APN by the time all is said and done
Wednesday morning...may be some afternoon convective development
over eastern Upper with passage of primary PV anomaly and some lake
breeze component to the surface winds.  Having said that...current
flooding potential looks minimal unless precipitation efficiency
goes through the roof. Probabilistic river forecasts not indicating
a big response (perhaps due to the drawn out nature of the
event)...most susceptible areas right now would be north of the M-72
corridor that saw the greatest impact from the 21-23 June rainfall
event (where 6 hour flash flood guidance is less than 2 inches in a
few spots).  New Day 2 Excessive Rainfall Outlook continues to paint
eastern Upper/Tip of the Mitt/northwest Lower in the Marginal Risk
which continues to look quite reasonable.

Fourth of July holiday continues to look OK with precipitation
chances impinging from the west and south:  Still pushing the
optimistic narrative for the Fourth of July...frontal boundary well
south of the area and a little bubble of high pressure in the
vicinity. Seasonable temperatures in the 70s-lower 80s with not a
lot of wind.

More rain arrives Friday...probably lingers into Saturday:
Approaching short wave trough will ramp up rain possibilities once
again on Friday...some hints of deformation/wrap-around moisture
keeping some threat for showers going into Saturday.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 645 AM EDT Mon Jul 1 2024

High pressure will be overhead today, before heading east
tonight. VFR expected. Little in the way of clouds today, before
increasing high clouds tonight. Could be a touch of fog late
tonight (MBL briefly had vsby restrictions earlier this
morning), but for now it isn`t worth a mention. Light winds,
with onshore lake breezes this afternoon.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...JLD
SHORT TERM...JZ
LONG TERM...JPB
AVIATION...JZ