Severe Weather - Flooding

403
ACUS01 KWNS 260101
SWODY1
SPC AC 260100

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Sun Oct 25 2020

Valid 260100Z - 261200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe thunderstorms are not expected through tonight.

...Discussion...

Primary areas of thunderstorm development tonight will be the
southern Rockies vicinity in association with ascent and steep lapse
rates downstream from a shortwave trough, as well as farther east
across the southern Plains region. Storms across the southern Plains
will likely develop later tonight as a southerly low-level jet
strengthens, augmenting isentropic ascent and theta-e advection in
vicinity of a southwest-northeast oriented baroclinic zone. Activity
will remain elevated above a stable surface layer. While some hail
cannot be ruled out with storms over western TX where steep mid
level lapse rates and somewhat greater instability will reside,
activity is generally expected to remain below the severe threshold.

..Dial.. 10/26/2020

$$

081
ACUS02 KWNS 251731
SWODY2
SPC AC 251730

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Sun Oct 25 2020

Valid 261200Z - 271200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk for severe thunderstorms appears negligible across the U.S.
Monday through Monday night.

...Synopsis...
Amplified, large-scale eastern Pacific mid/upper ridging may become
suppressed, as a vigorous short wave impulse progresses around its
crest, from the Gulf of Alaska vicinity through southern Yukon.
However, models suggest that an embedded high center to the south
will generally maintain strength to the west of the  California
coast through this period.

In response to these developments, it appears that a significant
short wave trough, initially sharply digging to the lee of the
ridge, will contribute to the evolution of a deepening mid-level
low, near the base of amplifying larger-scale troughing to the
southeast of the high center.  The ECENS and NCEP SREF are in good
agreement that this will take place across southern Arizona,
generally Monday evening through daybreak Tuesday.

Downstream, mid/upper ridging likely will gradually build across
parts of the southern Great Plains and much of the Gulf Coast
through South Atlantic Coast states.

Along the southeastern periphery of this ridging, extending into the
subtropical western Atlantic, Tropical Storm Zeta is forecast to
migrate from the western Caribbean into the southern Gulf of Mexico,
near the northern Yucatan Peninsula vicinity.  As it does, models
indicate that a broad plume of tropical moisture will overspread
much of the Gulf of Mexico, and portions of the southern Florida
Peninsula, to the south of remnant frontal zone advancing away from
the Atlantic Seaboard.

At the same time, seasonably moist air also is expected to continue
advecting in a narrow plume around the northwestern periphery of the
ridging, from the southern Great Plains through the lower Ohio
Valley.  But models indicate that this will occur above a
reinforcing intrusion of cold air overspreading the Upper Midwest,
Great Lakes region and Ohio Valley, while also continuing to dam
southward to the lee of the southern Rockies, toward the Rio Grande
Valley.

Damming of more modestly cool air, associated with a preceding cold
intrusion, appears likely to proceed to the lee of the southern
Appalachian.  And, aside from the southern Florida Peninsula,
generally stable boundary-layer conditions are likely to prevail
east of the Rockies, as well as across much of the West.

...Florida...
Mid/upper support likely will be negligible/weak, but scattered,
mostly diurnal thunderstorm activity appears possible Monday across
southern into central portions of the Florida Peninsula.

...Southern Great Plains into middle Mississippi Valley...
Weak boundary-layer destabilization may be possible south of the
leading edge of the reinforcing cold front, particularly across the
Texas coastal plain.  However, mid-level inhibition is expected to
confine thunderstorm development to the vicinity of the mid-level
baroclinic zone remaining quasi-stationary to the northwest.

Scattered thunderstorm development may be ongoing early Monday,
aided by frontogenetic forcing, and perhaps forcing in the right
entrance region of a mid/upper jet forecast to shift from the
southern Great Plains Red River Valley vicinity through the Ozark
Plateau during the day Monday.

East of the evolving Southwestern mid-level low, increasing forcing
for ascent may contribute to another round of thunderstorm
development across parts of the Texas South Plains and Big Country
into Red River Valley Monday night.

..Kerr.. 10/25/2020

$$

866
NWUS53 KAPX 241019
LSRAPX

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GAYLORD MI
619 AM EDT SAT OCT 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 PM     FLOOD            4 SW MACKINAW CITY      45.75N 84.79W
10/23/2020                   EMMET              MI   911 CALL CENTER

            WILDERNESS PARK DR. CLOSED BETWEEN HEADLANDS
            RD AND STRAITS VIEW DR. DUE TO FLOODING.
            CLOSURE LASTED 5 HOURS.


&&

$$

000
FXUS63 KAPX 260345
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EDT Sun Oct 25 2020

.UPDATE...
Issued at 955 PM EDT Sun Oct 25 2020

Weak wave continues to make its way thru the Great Lakes late this
evening...resulting in an area of light precip impacting much of
Northern Michigan attm. Precip type has been mixed as expected...
ranging from all rain along the lakeshores to all snow in the
higher elevations. Snow accumulation has been quite light...mainly
a dusting on grassy areas for locations receiving all snow. Low
level temps will continue to cool as we head into the overnight
hours...with expected lows in the upper 20s and lower 30s. Precip
type will gradually lean toward all snow for most locations as
cooling continues...but think most shoreline areas will see mainly
a mix overnight. Total snow accumulations will be light...
generally an inch or less for inland areas.

&&

.NEAR TERM...(Through Monday)
Issued at 209 PM EDT Sun Oct 25 2020

...Light Snow and Rain Tonight...

High Impact Weather...None expected, although a few slippery spots
are possible.

Primary Forecast Concerns...Precipitation amounts and snow
accumulation amounts.

High pressure across the region will track off to our east as
weak low pressure and an associated short wave move in from the
west tonight. Model soundings/cross sections show an increase in
moisture through the column (especially mid and low levels)
through tonight. Forcing is weak however. Expect light
precipitation to spread into the region late this afternoon across
the far west and into the remainder of the forecast area by later
this evening. Mainly snow is expected across the higher terrain
where around an inch of accumulation is expected. Even a few
slippery spots may develop as slushy snow hardens up as
temperatures slip below freezing overnight. Elsewhere, rain or
mixed rain and snow will likely transition over to mostly snow.
The exception may be near the lakeshores where the relatively
warmer waters of the Great Lakes will likely keep precipitation
from totally changing over to all snow. Lingering precipitation
Monday with northerly winds picking up enough to focus some lake
effect (mainly rain) near the lakeshores. Lows tonight in the
upper 20s to low 30s. Highs Monday in the upper 30s to low 40s.

&&

.SHORT TERM...(Monday night through Wednesday)
Issued at 209 PM EDT Sun Oct 25 2020

...Temperatures trending to more normal-like by Wednesday...

High impact weather potential: None.

Pattern synopsis/forecast:

Broad troughing will continue to dominate northern Conus weather,
including the Great Lakes, right into the middle portions of this
week. Northern stream flow will largely be void of any significant
shortwaves, with nearly all focus for active weather expected to be
tied to slow moving upper level low pressure cutting from the desert
southwest into the southern Plains. This system will intercept any
northward moisture flux from the Gulf of Mexico...and combined with
relatively high pressure dominating the surface conditions to its
north, is setting the stage for a period of rather quiet conditions
across the northern Great Lakes.

Primary forecast concerns/challenges: Cloud/temperature trends and
addressing some lingering light lake effect shower potential.

Details:

Still plenty chilly enough Monday night to drum up more lake induced
showers, although light winds/possible land breeze development may
focus most of these showers offshore (even hints of mesolow
development across northern Lake Michigan). Approach of subtle wave
and attendant more focused west/southwest boundary layer flow will
likely punt any activity inland early Tuesday morning, with rapid
drying and development of warm air advection ending any lake effect
nonsense quickly during the day. Those dry conditions look to remain
steadfast right into Wednesday as a dry low level environment and
continued warming negates any lake moisture contribution. Highs
Tuesday will be similar to those experienced the last few days, with
readings in the upper 30s to middle 40s. Increasingly gusty
southwest winds will help drive temperatures up to near normal
levels on Wednesday, with highs ranging from the middle 40s to lower
50s.

.LONG TERM...(Wednesday night through Sunday)
Issued at 209 PM EDT Sun Oct 25 2020

...Quiet with seasonable temperatures...

High impact weather: None.

Real only feature of interest through the remainder of the week on
into the weekend is eventual ejection of that southern stream
wave/closed low on Thursday. System will have plenty of moisture at
its disposal as tropical system "Zeta" moves north out of the
Caribbean. Pattern recognition of northern stream flow placement
supports vast majority of mid-range guidance ensembles of keeping
any rain with this system well off to our south across the Ohio
Valley and far southern Great Lakes. Will definitely keep the
forecast trended in this dry direction. Really nothing of
significance thereafter, with passage of moisture starved northern
wave bringing a bit of colder air Thursday night into Friday. Strong
hints that overall troughing will relax heading into the weekend as
upstream flow across the northern Pacific undergoes significant
transformation. This looks to punt cold air anomalies well north
into Canada, flooding the northern Conus with modified Pacific air.
As such, current trends support highs both Halloween and Sunday well
up into the 40s and lower 50s. Dry weather expected to continue into
at least the start of the weekend, with some hints of a weak wave
bringing a few light showers on Sunday (although have to admit
definitely not sold on Sunday rain chances given dearth of moisture
and significant timing issues within mid range guidance).

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1145 PM EDT Sun Oct 25 2020

Cold high pressure will remain centered to our north and west...
as a weak wave rides up thru the Great Lakes region overnight
into Monday. Widespread light precip will continue to impact
Lower Michigan overnight into Monday morning...with some diminish
in precip coverage by Monday afternoon and night as the wave pull
away from our area. Some northerly flow lake effect precip will
develop Monday night as colder air advects into the region...
impacting mainly TVC and MBL. Precip type will generally be snow
mixed at times with rain...especially Monday morning. Generally
MVFR and IFR conditions can be expected for the next 24 hours.
Light/variable winds overnight will become northerly at around 10
kts by Monday afternoon.

&&

.MARINE...
Issued at 209 PM EDT Sun Oct 25 2020

High pressure moves off to the east with a weak area of low
pressure crossing the lakes tonight into Monday. Light winds
through tonight will briefly increase Monday (out of the north)
before becoming light again Monday night into Tuesday. No
headlines are anticipated over the next couple of days.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...MR
NEAR TERM...AS
SHORT TERM...MB
LONG TERM...MB
AVIATION...MR
MARINE...AS

410
ACUS11 KWNS 252317
SWOMCD
SPC MCD 252317
COZ000-260315-

Mesoscale Discussion 1754
NWS Storm Prediction Center Norman OK
0617 PM CDT Sun Oct 25 2020

Areas affected...West-central to south-central CO

Concerning...Heavy snow

Valid 252317Z - 260315Z

SUMMARY...Heavy snow that has affected portions of the Upper CO
Valley along the I-70 corridor should shift south and may subside,
while a separate band of heavy snow likely forms across portions of
the Upper AR Valley, including the I-25 corridor near Pueblo.
Snowfall rates of 2-3 inches/hour are expected in the stronger
bursts.

DISCUSSION...Intense frontogenetic forcing for ascent associated
with a very tight thermal gradient arcing in a zigzag pattern across
west-central to south-central CO has supported a persistent band of
heavy snow just to the cold side of the slowly-southward shifting
surface front. This band of heavy snow has recently affected the
I-70 corridor in the Upper CO Valley. Radar/satellite imagery
suggest a separate band of probable heavy snow is beginning to form
off the northern Sangre de Cristos as elevated convection with CG
lightning that formed farther west-southwest overspreads this
portion of the baroclinic zone. Both convection allowing and
parameterized guidance are largely consistent in suggesting that
this will be the favored corridor for persistent heavy snow through
the evening. Rates should reach 2-3 inches/hour in the stronger
convective bursts that affect lower terrain across the Upper AR
Valley across portions of I-25 from near Pueblo to Trinidad.

..Grams.. 10/25/2020

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

ATTN...WFO...PUB...BOU...GJT...

LAT...LON   38590514 38560478 38530422 38280413 37790414 37240433
            37090476 37500510 37910555 38090613 38370654 38500702
            38430785 38520834 38710861 39130865 39390814 39560775
            39560713 39580659 38700555 38590514

000
WGUS43 KAPX 230335
FLWAPX

BULLETIN - EAS ACTIVATION REQUESTED
Flood Warning
National Weather Service Gaylord MI
1135 PM EDT Thu Oct 22 2020

MIC009-019-029-031-039-047-055-079-089-101-119-137-165-232100-
/O.NEW.KAPX.FA.W.0011.201023T0335Z-201023T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Antrim MI-Benzie MI-Charlevoix MI-Cheboygan MI-Crawford MI-Emmet MI-
Grand Traverse MI-Kalkaska MI-Leelanau MI-Manistee MI-Montmorency MI-
Otsego MI-Wexford MI-
1135 PM EDT Thu Oct 22 2020

The National Weather Service in Gaylord has issued a

* Flood Warning for...
  Antrim County in northern Michigan...
  Benzie County in northern Michigan...
  Southeastern Charlevoix County in northern Michigan...
  Southwestern Cheboygan County in northern Michigan...
  Northwestern Crawford County in northern Michigan...
  Southeastern Emmet County in northern Michigan...
  Grand Traverse County in northern Michigan...
  Northern Kalkaska County in northern Michigan...
  Leelanau County in northern Michigan...
  Northern Manistee County in northern Michigan...
  Western Montmorency County in northern Michigan...
  Otsego County in northern Michigan...
  Northern Wexford County in northern Michigan...

* Until 500 PM EDT Friday.

* At 1135 PM EDT, Doppler radar indicated heavy rain due to
  thunderstorms. Flooding is already occurring in the warned area.
  Between 1.5 and 3.5 inches of rain have fallen.

Some locations that will experience flooding include...
  Traverse City, Boyne City, Gaylord, East Jordan, Leland, Kalkaska,
  Elk Rapids, Mancelona, Frankfort, Bellaire, Thompsonville, Empire,
  Ellsworth, Beulah, Antrim, Arcadia, Bingham, Elmira, Kingsley and
  Torch Lake.

Additional rainfall amounts of 1 to 2 inches are expected in the
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flood Warning means that flooding is imminent or occurring. All
interested parties should take necessary precautions immediately.

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4427 8638 4436 8632 4460 8628 4491 8604
      4513 8551 4500 8555 4501 8543 4516 8543
      4526 8518 4536 8461 4506 8430

$$

mrunyan

686
WGUS83 KAPX 231822
FLSAPX

Flood Statement
National Weather Service Gaylord MI
222 PM EDT Fri Oct 23 2020

MIC009-019-029-031-039-047-055-079-089-101-119-137-165-231832-
/O.CAN.KAPX.FA.W.0011.000000T0000Z-201023T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Antrim MI-Benzie MI-Charlevoix MI-Cheboygan MI-Crawford MI-Emmet MI-
Grand Traverse MI-Kalkaska MI-Leelanau MI-Manistee MI-Montmorency MI-
Otsego MI-Wexford MI-
222 PM EDT Fri Oct 23 2020

...FLOOD WARNING IS CANCELLED FOR ANTRIM, BENZIE, SOUTHEASTERN
CHARLEVOIX, SOUTHWESTERN CHEBOYGAN, NORTHWESTERN CRAWFORD,
SOUTHEASTERN EMMET, GRAND TRAVERSE, NORTHERN KALKASKA, LEELANAU,
NORTHERN MANISTEE, WESTERN MONTMORENCY, OTSEGO AND NORTHERN WEXFORD
COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

LAT...LON 4427 8638 4436 8632 4460 8628 4491 8604
      4513 8551 4500 8555 4501 8543 4516 8543
      4526 8518 4536 8461 4506 8430

$$

mboguth