Flooding Continues in Arenac County Along the Rifle River

                        

944

ACUS01 KWNS 222000

SWODY1

SPC AC 221959



Day 1 Convective Outlook

NWS Storm Prediction Center Norman OK

0159 PM CST Sun Dec 22 2024



Valid 222000Z - 231200Z



...NO SEVERE THUNDERSTORM AREAS FORECAST...



...SUMMARY...

Severe thunderstorms are not forecast across the contiguous United

States through tonight.



...20Z Update...

Lightning flashes continue to be observed just offshore of the

northern CA coastline as a mid-level trough approaches the Pacific

Northwest. As the mid-level trough continues to advance toward the

coastline later this afternoon and evening, increased mid-level

cooling aloft will encourage at least isolated onshore thunderstorm

development. As such, no changes have been made to the previous

forecast.



..Squitieri.. 12/22/2024



.PREV DISCUSSION... /ISSUED 1003 AM CST Sun Dec 22 2024/



...Northern CA/Pacific Northwest coast through tonight...

Lightning flashes have been observed this morning within a

baroclinic band roughly 150 mi off the northern CA coast, in

association with a midlevel shortwave trough that will move inland

later today into tonight.  The potential for isolated lightning

flashes inland will begin this afternoon with elevated convection in

the warm conveyor belt across northwest CA/southwest OR.  Other

isolated lightning flashes may also occur this evening into early

tonight along the WA coast as steeper low-midlevel lapse rates and

weak buoyancy spread inland.



$$






                

                        

913

ACUS02 KWNS 221718

SWODY2

SPC AC 221716



Day 2 Convective Outlook

NWS Storm Prediction Center Norman OK

1116 AM CST Sun Dec 22 2024



Valid 231200Z - 241200Z



...NO SEVERE THUNDERSTORM AREAS FORECAST...



...SUMMARY...

Severe thunderstorms are not expected on Monday.



A midlevel shortwave trough will amplify from the central Rockies to

the south-central High Plains on Monday. A weak surface low will

likely develop across Texas into southern Oklahoma, with a modest

increase in low-level moisture across central/east Texas into

southern Oklahoma in advance of a cold front moving southeastward

across the southern High Plains. Increasing forcing for ascent and

elevated moisture transport should lead to increasing elevated

convection Monday night across north/northeast Texas into southeast

Oklahoma and the ArkLaTex. While a mid-level capping inversion may

tend to persist, updrafts should increasingly reach a sufficient

depth/temperature late Monday night into early Tuesday for at least

isolated thunderstorms. Severe thunderstorms are not currently

expected given access to only weak elevated buoyancy.



Isolated thunderstorms will also be possible late Monday night

across the coastal Pacific Northwest and northern California as

temperatures aloft cool with the approaching mid-level trough.



..Bentley.. 12/22/2024



$$






                

                        

700

NWUS53 KAPX 211504

LSRAPX



Preliminary Local Storm Report

National Weather Service Gaylord MI

1004 AM EST Sat Dec 21 2024



..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...

..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....

            ..REMARKS..



0700 AM     Snow             2 SE Elmira             45.05N 84.82W

12/21/2024  M4.5 Inch        Otsego             MI   Cocorahs



            Cocorahs station MI-OT-19 Elmira 2.2 ESE.



0700 AM     Snow             1 NW Waters             44.91N 84.72W

12/21/2024  M3.7 Inch        Otsego             MI   CO-OP Observer



            CO-OP Observer station APXM4 Gaylord 9 SSW.



0800 AM     Snow             2 N Suttons Bay         45.00N 85.65W

12/21/2024  M3.0 Inch        Leelanau           MI   Cocorahs



            Cocorahs station MI-LL-8 1 NNE Suttons Bay.



0700 AM     Snow             1 NW Fife Lake          44.58N 85.37W

12/21/2024  M3.0 Inch        Grand Traverse     MI   CO-OP Observer



            CO-OP Observer station FLAM4 Fife Lake 2

            WNW.





&&



$$












                

                        

913

FXUS63 KAPX 222300

AFDAPX



Area Forecast Discussion

National Weather Service Gaylord MI

600 PM EST Sun Dec 22 2024



.KEY MESSAGES...



- Widespread snowfall late tonight through Monday evening.



- Milder air builds the rest of the week. Potential of

  widespread rainfall next weekend.



&&



.SHORT TERM /THROUGH MONDAY/...

Issued at 329 PM EST Sun Dec 22 2024



Pattern/synopsis: High pressure is over Lk Ontario and moving

eastward. Return flow continues to increase in the western/

central lakes. This return flow will persist until low pressure,

now in NE, will cross northern MI late Monday. Patchy light

snow is occurring in northern MI, with some enhancement at times

in southerly flow into eastern upper MI.



Forecast: More substantial forcing/deeper moisture gradually

arrives late tonight/Monday. A digging upper trof crosses

northern MI late Monday. The strongest piece of energy seems

destined to cross central lower MI, with a secondary piece up

toward eastern upper.



Top-down saturation will result in a warm-advection wing of

snow, developing right over our heads late tonight. Though the

better dynamics/forcing will be further south, and later on

Monday, eastern upper MI does have the advantage of some lake

enhancement off of Lakes MI and Huron, in increasing sw

1000-850mb winds. Better snow rates (at least in more isolated

locales) will get started sooner there. The window for synoptic

precip that far north is narrower; precip will be tapering

Monday afternoon. Our low- and mid-level airmass is rapidly

warming across the region, even in the UP. So our max lift

quickly evolves to a layer a little too warm for excellent DGZ

growth. That, and surface temps climbing into the upper 20s/near

30f by Monday, will hurt snow- liquid ratios. Lower teens SLRs

are expected across the area late tonight into Monday.



Strongest warm advection forcing/ascent is very late tonight

into midday Monday. Another window for better precip rates is

possible later Monday, as the shortwave directly crosses the

area. Some models have this wave closing off, with enough

deformation in its vicinity to give another boost to precip

rates. Seems that most short-term guidance isn`t quite that

vigorous. Absolute moisture content will be unseasonably high

(pretty wild given our airmass over the past 24 hours). We have

minimal chances for mixed precip over the short-term period.

Maybe MBL can mix with rain Monday? Maybe Gladwin/Arenac Cos

sees a brief window of sleet Monday? Otherwise snow.



Snow totals in eastern upper: 1-5", with amounts increasing as

you head south and east. An advisory has been issued for almost

all of this area. The western Chip Co zone was left out; snow

amounts are a very marginal 1-4", in a zone that has had oodles

and oodles of snow so far this winter. Northern lower: 3-7",

lowest west of M-37, and marginally highest near PLN. Advisory

issued for all zones near/east of M-66, and near/north of M-55

(as well as Beaver Isl). More marginal snow totals in nw lower

MI, and a later onset of better snow rates that far sw, left me

to keep them out for now. It`s more likely that Gladwin/Arenac

Cos will need an advisory, but much later precip onset down

there precludes an issuance at this time.



Temps rise into the 20s by morning. Highs Monday upper 20s to

lower 30s.



Thanks for coord MQT/DTX/GRR.



&&



.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...

Issued at 329 PM EST Sun Dec 22 2024



Pattern Synopsis/Forecast:



Longwave 500mb ridging continues to build across the CONUS this

week, advecting mild air into the Great Lakes region on

southerly flow. The entirety of the long term forecast period

will be a huge transition compared to current Arctic

temperatures. High temperatures will begin around freezing this

Tuesday and climb to the mid 40s by the end of the week. This

will result in precipitation remaining mainly in liquid form

after the well advertised short wave departs at the start of of

the forecast period. Next chance of widespread rainfall will be

around the Friday night/Saturday timeframe as southern stream

troughing deepens over the plains and moves a cyclone across the

country this weekend.



Primary forecast concerns/key messages:



-Snowfall continues Monday night before mild air builds the remainder

of the week: Clipper system will continue a few more hours of

snowfall as it departs the CWA to the east. Only areas likely to see

a couple inches of accumulations after 00Z Tuesday will be east of I-

75 along Northern Lower. Most of the impactful weather would have

departed the CWA, but a few areas near the shorelines of northern

lower could potentially see some different types of precipitation

mix as warm advection pushes a low level warm nose over mid and

southern Michigan. Chances of freezing rain remain very low, but

liquid rain or sleet could freeze on localized cool surfaces that

could make a short period of slick conditions on roadways. Otherwise

warm(er) air builds across the Great Lakes, resulting in a slow

diminishing of the current snowpack built this December. Melting

will start off slow, as highs remain just above Freezing Monday and

Tuesday, but highs in the upper 30s to low 40s with dew points above

freezing after Christmas will give ideal thermodynamic conditions to

rapidly melt snow across the majority of Northern Michigan by the

end of the week.



-Watching for potential of widespread rainfall moving across the

midwest next weekend: Long range ensemble guidance is starting to

materialize a potential cyclone to track across the northwoods this

around the Friday Night/Saturday timeframe. Current trends in

temperatures keep the majority of QPF as liquid rainfall, but a few

members could mix a little snow into the higher terrain areas of

northern lower and eastern upper if overnight temperature cool

enough. More details will prevail with future guidance, but we will

continue to monitor this set up as it evolves.



&&



.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...

Issued at 600 PM EST Sun Dec 22 2024



Arctic high will continue to exit eastward away from the Western

Great Lakes as low pressure develops over the Central and

Northern Plains. Return moist southerly flow setting up across

the Western Great Lakes between these two system will begin to

generate widespread snow across Eastern Upper and Lower Michigan

tonight and will continue thru much of Monday. Conditions will

deteriorate to IFR later tonight into Monday as the widespread

snow develops. Surface winds will remain S/SE at 10 to 15 kts

for the next 24 hours...with a few higher gusts possible.



&&



.APX WATCHES/WARNINGS/ADVISORIES...

MI...Winter Weather Advisory from 2 AM to 10 PM EST Monday for

     MIZ016>018-021>024-027>030-033>036-098-099.

     Winter Weather Advisory from 11 PM this evening to 1 PM EST

     Monday for MIZ087-088-095>097.

MARINE...Small Craft Advisory from 11 PM this evening to 1 PM EST

     Monday for LHZ346>349.

     Small Craft Advisory until 9 AM EST Monday for LMZ323-341-342-

     344>346.

     Small Craft Advisory until 3 AM EST Monday for LSZ321.



&&



$$



SHORT TERM...JZ

LONG TERM...SJC

AVIATION...MLR






                

                        

271

ACUS11 KWNS 221514

SWOMCD

SPC MCD 221513

NDZ000-MTZ000-221915-



Mesoscale Discussion 2274

NWS Storm Prediction Center Norman OK

0913 AM CST Sun Dec 22 2024



Areas affected...Northwest to central North Dakota into far

northeast Montana



Concerning...Freezing rain



Valid 221513Z - 221915Z



SUMMARY...Light to moderate freezing rain (with rates possibly as

high as 0.1 inch/hour) is expected to begin across far northeast

Montana and into northwest North Dakota by early afternoon.



DISCUSSION...Regional radar mosaics show light to moderate

precipitation overspreading much of eastern MT, gradually moving

east into ND within the left-exit region of a modest mid-level jet.

12 UTC soundings from GGW and BIS show a pronounced 8-9 C warm nose

between 900 to 850 mb with sub-freezing temperatures at the surface

(including an impressive 22 C inversion on the BIS sounding). While

some modulation of the low-level inversion is expected through early

afternoon via wet-bulb cooling within the warm nose and downward

mixing of warmer air near the surface, forecast guidance and recent

surface obs suggest that most locations across northwest to central

ND will maintain favorable low-level thermal profiles for freezing

rain through much of the day.



Live web cams from Williston and Dickinson, ND show little in the

way of ongoing precipitation as of 15 UTC, suggesting that the

initial wave of light precipitation currently moving over western ND

is mainly saturating a dry 850-500 mb layer. This gradual saturation

will promote steadier precipitation through early/mid-afternoon as

additional showers migrate east from MT in tandem with the upper

wave/jet. As such, the potential for freezing rain is expected to

increase heading into the afternoon hours. Morning guidance suggests

freezing rain rates up to 0.03 inch/hour are likely, but more

aggressive solutions (notably the HRRR) hint that higher rates up to

0.1 inch/hour are possible (though not probable given relatively

weak mesoscale forcing for ascent).



..Moore.. 12/22/2024



...Please see www.spc.noaa.gov for graphic product...



ATTN...WFO...BIS...GGW...



LAT...LON   48530222 47930087 47690052 47470038 47010035 46830046

            46730079 46740107 46870167 47170261 47440340 47540373

            47720412 48060434 48440428 48580419 48730381 48760310

            48530222